xref: /freebsd/sys/net/iflib.c (revision d3e5082ce4dcb154cbf50cba05d8f1dbbd55a5fc)

/*-
 * Copyright (c) 2014-2018, Matthew Macy <mmacy@mattmacy.io>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *
 *  2. Neither the name of Matthew Macy nor the names of its
 *     contributors may be used to endorse or promote products derived from
 *     this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_acpi.h"

#include <sys/param.h>
#include <sys/types.h>
#include <sys/bus.h>
#include <sys/counter.h>
#include <sys/eventhandler.h>
#include <sys/fail.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/module.h>
#include <sys/kobj.h>
#include <sys/pcpu.h>
#include <sys/proc.h>
#include <sys/rman.h>
#include <sys/sbuf.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/taskqueue.h>
#include <sys/limits.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_private.h>
#include <net/if_types.h>
#include <net/if_media.h>
#include <net/bpf.h>
#include <net/ethernet.h>
#include <net/mp_ring.h>
#include <net/debugnet.h>
#include <net/pfil.h>
#include <net/vnet.h>

#include <netinet/in.h>
#include <netinet/in_pcb.h>
#include <netinet/tcp_lro.h>
#include <netinet/in_systm.h>
#include <netinet/if_ether.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <netinet/ip_var.h>
#include <netinet6/ip6_var.h>

#include <machine/bus.h>
#include <machine/in_cksum.h>

#include <vm/vm.h>
#include <vm/pmap.h>

#include <dev/led/led.h>
#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>
#include <dev/pci/pci_private.h>

#include <net/iflib.h>
#include <net/if_vf_status.h>

#include "ifdi_if.h"

#ifdef PCI_IOV
#include <dev/pci/pci_iov.h>
#endif

#include <sys/bitstring.h>
/*
 * enable accounting of every mbuf as it comes in to and goes out of
 * iflib's software descriptor references
 */
#define MEMORY_LOGGING 0
/*
 * Enable mbuf vectors for compressing long mbuf chains
 */

/*
 * NB:
 * - Prefetching in tx cleaning should perhaps be a tunable. The distance ahead
 *   we prefetch needs to be determined by the time spent in m_free vis a vis
 *   the cost of a prefetch. This will of course vary based on the workload:
 *      - NFLX's m_free path is dominated by vm-based M_EXT manipulation which
 *        is quite expensive, thus suggesting very little prefetch.
 *      - small packet forwarding which is just returning a single mbuf to
 *        UMA will typically be very fast vis a vis the cost of a memory
 *        access.
 */

/*
 * File organization:
 *  - private structures
 *  - iflib private utility functions
 *  - ifnet functions
 *  - vlan registry and other exported functions
 *  - iflib public core functions
 *
 *
 */
static MALLOC_DEFINE(M_IFLIB, "iflib", "ifnet library");

#define	IFLIB_RXEOF_MORE	(1U << 0)
#define	IFLIB_RXEOF_EMPTY	(2U << 0)
#define	IFLIB_TXQ_QUIESCING		(1U << 31)
#define	IFLIB_TXQ_PRODUCER_LLC_SHIFT	20
#define	IFLIB_TXQ_PRODUCER_MAX	\
	((1U << IFLIB_TXQ_PRODUCER_LLC_SHIFT) - 1)
#define	IFLIB_TXQ_PRODUCER(_state) \
	((_state) & IFLIB_TXQ_PRODUCER_MAX)
#define	IFLIB_TXQ_PRODUCER_LLC_MASK	\
	(~(IFLIB_TXQ_QUIESCING | IFLIB_TXQ_PRODUCER_MAX))
#define	IFLIB_TXQ_PRODUCER_LLC(_state) \
	(((_state) & IFLIB_TXQ_PRODUCER_LLC_MASK) >> \
	    IFLIB_TXQ_PRODUCER_LLC_SHIFT)

CTASSERT(MAXCPU - 1 <= (IFLIB_TXQ_PRODUCER_LLC_MASK >>
    IFLIB_TXQ_PRODUCER_LLC_SHIFT));
struct iflib_txq;
typedef struct iflib_txq *iflib_txq_t;
struct iflib_rxq;
typedef struct iflib_rxq *iflib_rxq_t;
struct iflib_fl;
typedef struct iflib_fl *iflib_fl_t;

struct iflib_ctx;

/*
 * This state describes access to queue mappings owned by iflib.  It does not
 * describe driver-owned administrative DMA or the PCI function's power state.
 * Normal transitions are serialized by ifc_ctx_sx.
 *
 * Only STOPPED establishes that the device can no longer access the mappings;
 * a failed initialization can leave queues active.  IFF_UP separately records
 * administrative intent.  Existing datapath users still use IFF_DRV_RUNNING,
 * but clearing that flag does not establish quiescence: the watchdog clears
 * it before the admin task stops the hardware.  Use this state for lifecycle
 * decisions under ifc_ctx_sx, not as an unlocked datapath admission check.
 */
enum iflib_datapath_state {
	IFLIB_DP_UNKNOWN = 0,
	IFLIB_DP_STOPPED,
	IFLIB_DP_FAILED,
	IFLIB_DP_STARTING,
	IFLIB_DP_RUNNING,
	IFLIB_DP_STOPPING,
};

/*
 * Power-transition state is separate from datapath ownership.  It gates
 * configuration callbacks while the device is entering or remains in low
 * power without making any claim about driver-owned firmware or admin DMA.
 */
enum iflib_pm_state {
	IFLIB_PM_ACTIVE = 0,
	IFLIB_PM_SUSPENDING,
	IFLIB_PM_SUSPENDED,
};

static void iru_init(if_rxd_update_t iru, iflib_rxq_t rxq, uint8_t flid);
static void iflib_timer(void *arg);
static void iflib_tqg_detach(if_ctx_t ctx);
static int  iflib_simple_transmit(if_t ifp, struct mbuf *m);
static void iflib_simple_if_start(if_t ifp);
static void iflib_simple_txq_drain(iflib_txq_t txq);

typedef struct iflib_filter_info {
	driver_filter_t *ifi_filter;
	void *ifi_filter_arg;
	struct grouptask *ifi_task;
	void *ifi_ctx;
} *iflib_filter_info_t;

struct iflib_ctx {
	KOBJ_FIELDS;
	/*
	 * Pointer to hardware driver's softc
	 */
	void *ifc_softc;
	device_t ifc_dev;
	if_t ifc_ifp;

	cpuset_t ifc_cpus;
	if_shared_ctx_t ifc_sctx;
	struct if_softc_ctx ifc_softc_ctx;

	struct sx ifc_ctx_sx;
	struct mtx ifc_state_mtx;

	iflib_txq_t ifc_txqs;
	iflib_rxq_t ifc_rxqs;
	uint32_t ifc_if_flags;
	uint32_t ifc_flags;
	enum iflib_datapath_state ifc_datapath_state;
	enum iflib_pm_state ifc_pm_state;
	uint32_t ifc_max_fl_buf_size;
	uint32_t ifc_rx_mbuf_sz;

	int ifc_link_state;
	uint32_t ifc_tx_watchdog_events;
	struct cdev *ifc_led_dev;
	int ifc_led_state;
	struct resource *ifc_msix_mem;

	struct if_irq ifc_legacy_irq;
	struct task ifc_admin_task;
	struct task ifc_led_task;
	struct task ifc_vflr_task;
	struct taskqueue *ifc_tq;
	struct iflib_filter_info ifc_filter_info;
	struct ifmedia	ifc_media;
	struct ifmedia	*ifc_mediap;

	struct sysctl_ctx_list ifc_sysctl_ctx;
	struct sysctl_oid *ifc_sysctl_node;
	uint16_t ifc_sysctl_ntxqs;
	uint16_t ifc_sysctl_nrxqs;
	uint16_t ifc_sysctl_qs_eq_override;
	uint16_t ifc_sysctl_rx_budget;
	uint16_t ifc_sysctl_tx_abdicate;
	uint16_t ifc_sysctl_core_offset;
#define	CORE_OFFSET_UNSPECIFIED	0xffff
	uint8_t  ifc_sysctl_separate_txrx;
	uint8_t  ifc_sysctl_use_logical_cores;
	uint16_t ifc_sysctl_extra_msix_vectors;
	bool     ifc_cpus_are_physical_cores;
	bool     ifc_core_offset_ref;
	bool     ifc_sysctl_simple_tx;
	bool     ifc_sysctl_tx_defer_mfree;
	uint16_t ifc_sysctl_tx_reclaim_thresh;
	uint16_t ifc_sysctl_tx_reclaim_ticks;

	qidx_t ifc_sysctl_ntxds[8];
	qidx_t ifc_sysctl_nrxds[8];
	struct if_txrx ifc_txrx;
#define isc_txd_encap		ifc_txrx.ift_txd_encap
#define isc_txd_flush		ifc_txrx.ift_txd_flush
#define isc_txd_credits_update	ifc_txrx.ift_txd_credits_update
#define isc_rxd_available	ifc_txrx.ift_rxd_available
#define isc_rxd_pkt_get		ifc_txrx.ift_rxd_pkt_get
#define isc_rxd_refill		ifc_txrx.ift_rxd_refill
#define isc_rxd_flush		ifc_txrx.ift_rxd_flush
#define isc_legacy_intr		ifc_txrx.ift_legacy_intr
#define isc_txq_select		ifc_txrx.ift_txq_select
#define isc_txq_select_v2	ifc_txrx.ift_txq_select_v2

	eventhandler_tag ifc_vlan_attach_event;
	eventhandler_tag ifc_vlan_detach_event;
	struct ether_addr ifc_mac;
};

void *
iflib_get_softc(if_ctx_t ctx)
{

	return (ctx->ifc_softc);
}

device_t
iflib_get_dev(if_ctx_t ctx)
{

	return (ctx->ifc_dev);
}

if_t
iflib_get_ifp(if_ctx_t ctx)
{

	return (ctx->ifc_ifp);
}

struct ifmedia *
iflib_get_media(if_ctx_t ctx)
{

	return (ctx->ifc_mediap);
}

void
iflib_set_mac(if_ctx_t ctx, uint8_t mac[ETHER_ADDR_LEN])
{

	bcopy(mac, ctx->ifc_mac.octet, ETHER_ADDR_LEN);
}

if_softc_ctx_t
iflib_get_softc_ctx(if_ctx_t ctx)
{

	return (&ctx->ifc_softc_ctx);
}

if_shared_ctx_t
iflib_get_sctx(if_ctx_t ctx)
{

	return (ctx->ifc_sctx);
}

uint16_t
iflib_get_extra_msix_vectors_sysctl(if_ctx_t ctx)
{

	return (ctx->ifc_sysctl_extra_msix_vectors);
}

#define IP_ALIGNED(m)		((((uintptr_t)(m)->m_data) & 0x3) == 0x2)
#define CACHE_PTR_INCREMENT	(CACHE_LINE_SIZE / sizeof(void *))
#define CACHE_PTR_NEXT(ptr)	((void *)(roundup2(ptr, CACHE_LINE_SIZE)))

#define LINK_ACTIVE(ctx)	((ctx)->ifc_link_state == LINK_STATE_UP)
#define CTX_IS_VF(ctx)		((ctx)->ifc_sctx->isc_flags & IFLIB_IS_VF)

typedef struct iflib_sw_rx_desc_array {
	bus_dmamap_t	*ifsd_map;	/* bus_dma maps for packet */
	struct mbuf	**ifsd_m;	/* pkthdr mbufs */
	caddr_t		*ifsd_cl;	/* direct cluster pointer for rx */
	bus_addr_t	*ifsd_ba;	/* bus addr of cluster for rx */
} iflib_rxsd_array_t;

typedef struct iflib_sw_tx_desc_array {
	bus_dmamap_t	*ifsd_map;	/* bus_dma maps for packet */
	bus_dmamap_t	*ifsd_tso_map;	/* bus_dma maps for TSO packet */
	struct mbuf	**ifsd_m;	/* pkthdr mbufs */
	struct mbuf	**ifsd_m_defer;	/* deferred mbuf ptr */
	struct mbuf	**ifsd_m_deferb;/* deferred mbuf backing ptr */
} if_txsd_vec_t;

/* magic number that should be high enough for any hardware */
#define IFLIB_MAX_TX_SEGS		128
#define IFLIB_RX_COPY_THRESH		128
#define IFLIB_MAX_RX_REFRESH		32
/* The minimum descriptors per second before we start coalescing */
#define IFLIB_MIN_DESC_SEC		16384
#define IFLIB_DEFAULT_TX_UPDATE_FREQ	16
/* maximum number of txqs that can share an rx interrupt */
#define IFLIB_MAX_TX_SHARED_INTR	4

/* this should really scale with ring size - this is a fairly arbitrary value */
#define TX_BATCH_SIZE			32

#define IFLIB_RESTART_BUDGET		8


/*
 * Encode TSO or !TSO in the low bits of the tx ifsd_m pointer so as
 * to avoid defref'ing the mbuf to determine the correct busdma resources
 * to release
 */
#define IFLIB_TSO		(1ULL << 0)
#define IFLIB_NO_TSO		(2ULL << 0)
#define IFLIB_FLAGS_MASK	(0x3ULL)
#define IFLIB_SAVE_MBUF(mbuf, flags)	((void *)(((uintptr_t)mbuf) | flags))
#define IFLIB_GET_FLAGS(a)	((uintptr_t)a & IFLIB_FLAGS_MASK)
#define IFLIB_GET_MBUF(a)	((struct mbuf *)((uintptr_t)a & ~IFLIB_FLAGS_MASK))


#define	IFC_LEGACY		0x001
#define	IFC_QFLUSH		0x002
#define	IFC_MULTISEG		0x004
#define	IFC_INIT_FAILED		0x008
#define	IFC_SC_ALLOCATED	0x010
#define	IFC_INIT_DONE		0x020
#define	IFC_PREFETCH		0x040
#define	IFC_DO_RESET		0x080
#define	IFC_DO_WATCHDOG		0x100
#define	IFC_DO_RESET_IF_UP	0x200
#define	IFC_SPARE2		0x400
#define	IFC_IN_DETACH		0x800

#define	IFC_NETMAP_TX_IRQ	0x80000000

#define CSUM_OFFLOAD		(CSUM_IP_TSO | CSUM_IP6_TSO | CSUM_IP | \
				 CSUM_IP_UDP | CSUM_IP_TCP | CSUM_IP_SCTP | \
				 CSUM_IP6_UDP | CSUM_IP6_TCP | CSUM_IP6_SCTP)

struct iflib_txq {
	qidx_t		ift_in_use;
	qidx_t		ift_cidx;
	qidx_t		ift_cidx_processed;
	qidx_t		ift_pidx;
	uint8_t		ift_gen;
	uint8_t		ift_br_offset:1,
			ift_defer_mfree:1,
			ift_spare_bits0:6;
	uint16_t	ift_npending;
	uint16_t	ift_db_pending;
	uint16_t	ift_rs_pending;
	uint32_t	ift_last_reclaim;
	uint16_t	ift_reclaim_thresh;
	uint16_t	ift_reclaim_ticks;
	uint8_t		ift_txd_size[8];
	uint64_t	ift_processed;
	uint64_t	ift_cleaned;
	uint64_t	ift_processed_prev;
#if MEMORY_LOGGING
	uint64_t	ift_enqueued;
	uint64_t	ift_dequeued;
#endif
	uint64_t	ift_no_tx_dma_setup;
	uint64_t	ift_no_desc_avail;
	uint64_t	ift_mbuf_defrag_failed;
	uint64_t	ift_mbuf_defrag;
	uint64_t	ift_map_failed;
	uint64_t	ift_txd_encap_efbig;
	uint64_t	ift_pullups;
	uint64_t	ift_last_timer_tick;
	uint64_t	ift_drbr_direct;
	uint64_t	ift_drbr_stall;
	counter_u64_t	ift_drbr_deferred;
	counter_u64_t	ift_drbr_drops;
	counter_u64_t	ift_drbr_blocked;
	counter_u64_t	ift_drbr_remote;

	/* Lockless producer count and current llc. */
	volatile u_int	ift_producers   __aligned(CACHE_LINE_SIZE);

	struct mtx	ift_mtx;
	struct mtx	ift_db_mtx;

	/* constant values */
	if_ctx_t	ift_ctx;
	struct ifmp_ring	*ift_br;
	struct buf_ring	*ift_drbr;
	struct grouptask	ift_task;
	qidx_t		ift_size;
	qidx_t		ift_pad;
	uint16_t	ift_id;
	struct callout	ift_timer;
#ifdef DEV_NETMAP
	struct callout	ift_netmap_timer;
#endif /* DEV_NETMAP */

	if_txsd_vec_t	ift_sds;
	/*
	 * TX watchdog state, updated once per iflib_timer period.  The
	 * period count saturates instead of wrapping, and is 16 bits
	 * wide so that it still reaches any value
	 * net.iflib.tx_watchdog_periods is plausibly set to; an 8-bit
	 * counter would silently disable the check for a threshold
	 * above 255.
	 */
	qidx_t		ift_outstanding_prev;
	uint16_t	ift_wdog_armed;
	uint8_t		ift_closed;
	uint8_t		ift_update_freq;
	uint8_t		ift_spare0[2];	/* pad to the next pointer boundary */
	struct iflib_filter_info ift_filter_info;
	bus_dma_tag_t	ift_buf_tag;
	bus_dma_tag_t	ift_tso_buf_tag;
	iflib_dma_info_t	ift_ifdi;
#define	MTX_NAME_LEN	32
	char		ift_mtx_name[MTX_NAME_LEN];
	bus_dma_segment_t	ift_segs[IFLIB_MAX_TX_SEGS]  __aligned(CACHE_LINE_SIZE);
#ifdef IFLIB_DIAGNOSTICS
	uint64_t ift_cpu_exec_count[256];
#endif
} __aligned(CACHE_LINE_SIZE);

struct iflib_fl {
	qidx_t		ifl_cidx;
	qidx_t		ifl_pidx;
	qidx_t		ifl_credits;
	uint8_t		ifl_gen;
	uint8_t		ifl_rxd_size;
#if MEMORY_LOGGING
	uint64_t	ifl_m_enqueued;
	uint64_t	ifl_m_dequeued;
	uint64_t	ifl_cl_enqueued;
	uint64_t	ifl_cl_dequeued;
#endif
	/* implicit pad */
	bitstr_t	*ifl_rx_bitmap;
	qidx_t		ifl_fragidx;
	/* constant */
	qidx_t		ifl_size;
	uint16_t	ifl_buf_size;
	uint16_t	ifl_cltype;
	uma_zone_t	ifl_zone;
	iflib_rxsd_array_t	ifl_sds;
	iflib_rxq_t	ifl_rxq;
	uint8_t		ifl_id;
	bus_dma_tag_t	ifl_buf_tag;
	iflib_dma_info_t	ifl_ifdi;
	uint64_t	ifl_bus_addrs[IFLIB_MAX_RX_REFRESH] __aligned(CACHE_LINE_SIZE);
	qidx_t		ifl_rxd_idxs[IFLIB_MAX_RX_REFRESH];
}  __aligned(CACHE_LINE_SIZE);

static inline qidx_t
get_inuse(int size, qidx_t cidx, qidx_t pidx, uint8_t gen)
{
	qidx_t used;

	if (pidx > cidx)
		used = pidx - cidx;
	else if (pidx < cidx)
		used = size - cidx + pidx;
	else if (gen == 0 && pidx == cidx)
		used = 0;
	else if (gen == 1 && pidx == cidx)
		used = size;
	else
		panic("bad state");

	return (used);
}

#define TXQ_AVAIL(txq) ((txq->ift_size - txq->ift_pad) -\
	    get_inuse(txq->ift_size, txq->ift_cidx, txq->ift_pidx, txq->ift_gen))

#define	MAX_TX_DESC(ctx) MAX((ctx)->ifc_softc_ctx.isc_tx_tso_segments_max, \
    (ctx)->ifc_softc_ctx.isc_tx_nsegments)

#define IDXDIFF(head, tail, wrap) \
	((head) >= (tail) ? (head) - (tail) : (wrap) - (tail) + (head))

struct iflib_rxq {
	if_ctx_t	ifr_ctx;
	iflib_fl_t	ifr_fl;
	struct pfil_head	*pfil;
	/*
	 * If there is a separate completion queue (IFLIB_HAS_RXCQ), this is
	 * the completion queue consumer index.  Otherwise it's unused.
	 */
	qidx_t		ifr_cq_cidx;
	uint16_t	ifr_id;
	uint8_t		ifr_nfl;
	uint8_t		ifr_ntxqirq;
	uint8_t		ifr_txqid[IFLIB_MAX_TX_SHARED_INTR];
	uint8_t		ifr_fl_offset;
	struct lro_ctrl		ifr_lc;
	struct grouptask	ifr_task;
	struct callout		ifr_watchdog;
	struct iflib_filter_info ifr_filter_info;
	iflib_dma_info_t	ifr_ifdi;

	/* dynamically allocate if any drivers need a value substantially larger than this */
	struct if_rxd_frag	ifr_frags[IFLIB_MAX_RX_SEGS] __aligned(CACHE_LINE_SIZE);
#ifdef IFLIB_DIAGNOSTICS
	uint64_t ifr_cpu_exec_count[256];
#endif
}  __aligned(CACHE_LINE_SIZE);

typedef struct if_rxsd {
	caddr_t *ifsd_cl;
	iflib_fl_t ifsd_fl;
} *if_rxsd_t;

/*
 * Only allow a single packet to take up most 1/nth of the tx ring
 */
#define MAX_SINGLE_PACKET_FRACTION 12
#define IF_BAD_DMA	((bus_addr_t)-1)

#define CTX_ACTIVE(ctx)	((if_getdrvflags((ctx)->ifc_ifp) & IFF_DRV_RUNNING))

#define CTX_LOCK_INIT(_sc)	sx_init(&(_sc)->ifc_ctx_sx, "iflib ctx lock")
#define CTX_LOCK(ctx)		sx_xlock(&(ctx)->ifc_ctx_sx)
#define CTX_UNLOCK(ctx)		sx_xunlock(&(ctx)->ifc_ctx_sx)
#define CTX_LOCK_DESTROY(ctx)	sx_destroy(&(ctx)->ifc_ctx_sx)

#define STATE_LOCK_INIT(_sc, _name)	mtx_init(&(_sc)->ifc_state_mtx, _name, "iflib state lock", MTX_DEF)
#define STATE_LOCK(ctx)		mtx_lock(&(ctx)->ifc_state_mtx)
#define STATE_UNLOCK(ctx)	mtx_unlock(&(ctx)->ifc_state_mtx)
#define STATE_LOCK_DESTROY(ctx)	mtx_destroy(&(ctx)->ifc_state_mtx)

#define CALLOUT_LOCK(txq)	mtx_lock(&txq->ift_mtx)
#define CALLOUT_UNLOCK(txq)	mtx_unlock(&txq->ift_mtx)

/* Our boot-time initialization hook */
static int	iflib_module_event_handler(module_t, int, void *);

static moduledata_t iflib_moduledata = {
	"iflib",
	iflib_module_event_handler,
	NULL
};

DECLARE_MODULE(iflib, iflib_moduledata, SI_SUB_INIT_IF, SI_ORDER_ANY);
MODULE_VERSION(iflib, 1);

MODULE_DEPEND(iflib, pci, 1, 1, 1);
MODULE_DEPEND(iflib, ether, 1, 1, 1);

TASKQGROUP_DEFINE(if_io_tqg, mp_ncpus, 1);
TASKQGROUP_DEFINE(if_config_tqg, 1, 1);

#ifndef IFLIB_DEBUG_COUNTERS
#ifdef INVARIANTS
#define IFLIB_DEBUG_COUNTERS 1
#else
#define IFLIB_DEBUG_COUNTERS 0
#endif /* !INVARIANTS */
#endif

static SYSCTL_NODE(_net, OID_AUTO, iflib, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
    "iflib driver parameters");

static SYSCTL_NODE(_debug_fail_point, OID_AUTO, iflib,
    CTLFLAG_RW | CTLFLAG_MPSAFE, 0, "iflib fail points");

static char iflib_register_fail_device[32];
SYSCTL_STRING(_debug_fail_point_iflib, OID_AUTO, register_device,
    CTLFLAG_RW | CTLFLAG_MPSAFE,
    iflib_register_fail_device, sizeof(iflib_register_fail_device),
    "device name eligible for registration fail points");

static char iflib_admin_task_fail_device[32];
SYSCTL_STRING(_debug_fail_point_iflib, OID_AUTO, admin_task_device,
    CTLFLAG_RW | CTLFLAG_MPSAFE,
    iflib_admin_task_fail_device, sizeof(iflib_admin_task_fail_device),
    "device name eligible for admin task fail points");

/*
 * XXX need to ensure that this can't accidentally cause the head to be moved backwards
 */
static int iflib_min_tx_latency = 0;
SYSCTL_INT(_net_iflib, OID_AUTO, min_tx_latency, CTLFLAG_RW,
    &iflib_min_tx_latency, 0,
    "minimize transmit latency at the possible expense of throughput");
static int iflib_no_tx_batch = 0;
SYSCTL_INT(_net_iflib, OID_AUTO, no_tx_batch, CTLFLAG_RW,
    &iflib_no_tx_batch, 0,
    "minimize transmit latency at the possible expense of throughput");
static int iflib_timer_default = 1000;
SYSCTL_INT(_net_iflib, OID_AUTO, timer_default, CTLFLAG_RW,
    &iflib_timer_default, 0, "number of ticks between iflib_timer calls");
/*
 * Consecutive timer periods a TX queue must stay frozen while demand
 * persists - see iflib_timer(), which defines those states - before the
 * hardware is asked whether it has completions pending.  Four periods is
 * roughly two seconds with the default timer interval: a healthy queue on
 * hardware that coalesces completion reports (e.g. 8254x, TXDCTL.WTHRESH)
 * stays frozen for at most two (measured on 82541PI), a wedged one until it
 * is reset.
 */
static int iflib_tx_watchdog_periods = 4;
SYSCTL_INT(_net_iflib, OID_AUTO, tx_watchdog_periods, CTLFLAG_RWTUN,
    &iflib_tx_watchdog_periods, 0,
    "consecutive frozen timer periods under demand before a TX queue is "
    "checked for a hang (0 disables the check)");

#define	IFLIB_SIMPLE_TXBR_MIN	64
#define	IFLIB_SIMPLE_TXBR_SIZE	1024
static int iflib_simple_txbr_size = IFLIB_SIMPLE_TXBR_SIZE;
SYSCTL_INT(_net_iflib, OID_AUTO, simple_txbr_size, CTLFLAG_RDTUN,
    &iflib_simple_txbr_size, 0,
    "number of entries in the simple tx deferral ring");
static u_int iflib_simple_drain_quota = 8;
SYSCTL_UINT(_net_iflib, OID_AUTO, simple_drain_quota, CTLFLAG_RWTUN,
    &iflib_simple_drain_quota, 0,
    "maximum packets sent per simple tx deferral ring drain from the tx task");
static u_int iflib_simple_drain_quota_thread = 65536;
SYSCTL_UINT(_net_iflib, OID_AUTO, simple_drain_quota_thread, CTLFLAG_RWTUN,
    &iflib_simple_drain_quota_thread, 0,
    "maximum packets sent per simple tx deferral ring drain from another thread");
static u_int iflib_max_producers = 8;
static bool iflib_single_llc __read_mostly;
static bool iflib_producer_gate __read_mostly;

static int
iflib_sysctl_max_producers(SYSCTL_HANDLER_ARGS)
{
	u_int max_producers;
	int error;

	max_producers = iflib_max_producers;
	error = sysctl_handle_int(oidp, &max_producers, 0, req);
	if (error != 0 || req->newptr == NULL)
		return (error);

	max_producers = MIN(max_producers, IFLIB_TXQ_PRODUCER_MAX);
	iflib_max_producers = max_producers;
	if (iflib_single_llc)
		iflib_producer_gate = mp_ncpus > max_producers;
	return (0);
}
SYSCTL_PROC(_net_iflib, OID_AUTO, max_producers,
    CTLTYPE_UINT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, &iflib_max_producers, 0,
    iflib_sysctl_max_producers, "IU",
    "maximum concurrent lockless producers per transmit queue");

/* Encoded llc for each CPU. */
static uint16_t iflib_cpu_llc[MAXCPU] __read_mostly;

#if IFLIB_DEBUG_COUNTERS

static int iflib_tx_seen;
static int iflib_tx_sent;
static int iflib_tx_encap;
static int iflib_rx_allocs;
static int iflib_fl_refills;
static int iflib_fl_refills_large;
static int iflib_tx_frees;

SYSCTL_INT(_net_iflib, OID_AUTO, tx_seen, CTLFLAG_RD, &iflib_tx_seen, 0,
    "# TX mbufs seen");
SYSCTL_INT(_net_iflib, OID_AUTO, tx_sent, CTLFLAG_RD, &iflib_tx_sent, 0,
    "# TX mbufs sent");
SYSCTL_INT(_net_iflib, OID_AUTO, tx_encap, CTLFLAG_RD, &iflib_tx_encap, 0,
    "# TX mbufs encapped");
SYSCTL_INT(_net_iflib, OID_AUTO, tx_frees, CTLFLAG_RD, &iflib_tx_frees, 0,
    "# TX frees");
SYSCTL_INT(_net_iflib, OID_AUTO, rx_allocs, CTLFLAG_RD, &iflib_rx_allocs, 0,
    "# RX allocations");
SYSCTL_INT(_net_iflib, OID_AUTO, fl_refills, CTLFLAG_RD, &iflib_fl_refills, 0,
    "# refills");
SYSCTL_INT(_net_iflib, OID_AUTO, fl_refills_large, CTLFLAG_RD,
    &iflib_fl_refills_large, 0, "# large refills");

static int iflib_txq_drain_flushing;
static int iflib_txq_drain_oactive;
static int iflib_txq_drain_notready;

SYSCTL_INT(_net_iflib, OID_AUTO, txq_drain_flushing, CTLFLAG_RD,
    &iflib_txq_drain_flushing, 0, "# drain flushes");
SYSCTL_INT(_net_iflib, OID_AUTO, txq_drain_oactive, CTLFLAG_RD,
    &iflib_txq_drain_oactive, 0, "# drain oactives");
SYSCTL_INT(_net_iflib, OID_AUTO, txq_drain_notready, CTLFLAG_RD,
    &iflib_txq_drain_notready, 0, "# drain notready");

static int iflib_encap_load_mbuf_fail;
static int iflib_encap_pad_mbuf_fail;
static int iflib_encap_txq_avail_fail;
static int iflib_encap_txd_encap_fail;

SYSCTL_INT(_net_iflib, OID_AUTO, encap_load_mbuf_fail, CTLFLAG_RD,
    &iflib_encap_load_mbuf_fail, 0, "# busdma load failures");
SYSCTL_INT(_net_iflib, OID_AUTO, encap_pad_mbuf_fail, CTLFLAG_RD,
    &iflib_encap_pad_mbuf_fail, 0, "# runt frame pad failures");
SYSCTL_INT(_net_iflib, OID_AUTO, encap_txq_avail_fail, CTLFLAG_RD,
    &iflib_encap_txq_avail_fail, 0, "# txq avail failures");
SYSCTL_INT(_net_iflib, OID_AUTO, encap_txd_encap_fail, CTLFLAG_RD,
    &iflib_encap_txd_encap_fail, 0, "# driver encap failures");

static int iflib_task_fn_rxs;
static int iflib_rx_intr_enables;
static int iflib_fast_intrs;
static int iflib_rx_unavail;
static int iflib_rx_ctx_inactive;
static int iflib_rx_if_input;
static int iflib_rxd_flush;

static int iflib_verbose_debug;

SYSCTL_INT(_net_iflib, OID_AUTO, task_fn_rx, CTLFLAG_RD, &iflib_task_fn_rxs, 0,
    "# task_fn_rx calls");
SYSCTL_INT(_net_iflib, OID_AUTO, rx_intr_enables, CTLFLAG_RD,
    &iflib_rx_intr_enables, 0, "# RX intr enables");
SYSCTL_INT(_net_iflib, OID_AUTO, fast_intrs, CTLFLAG_RD, &iflib_fast_intrs, 0,
    "# fast_intr calls");
SYSCTL_INT(_net_iflib, OID_AUTO, rx_unavail, CTLFLAG_RD, &iflib_rx_unavail, 0,
    "# times rxeof called with no available data");
SYSCTL_INT(_net_iflib, OID_AUTO, rx_ctx_inactive, CTLFLAG_RD,
    &iflib_rx_ctx_inactive, 0, "# times rxeof called with inactive context");
SYSCTL_INT(_net_iflib, OID_AUTO, rx_if_input, CTLFLAG_RD, &iflib_rx_if_input,
    0, "# times rxeof called if_input");
SYSCTL_INT(_net_iflib, OID_AUTO, rxd_flush, CTLFLAG_RD, &iflib_rxd_flush, 0,
    "# times rxd_flush called");
SYSCTL_INT(_net_iflib, OID_AUTO, verbose_debug, CTLFLAG_RW,
    &iflib_verbose_debug, 0, "enable verbose debugging");

#define DBG_COUNTER_INC(name) atomic_add_int(&(iflib_ ## name), 1)
static void
iflib_debug_reset(void)
{
	iflib_tx_seen = iflib_tx_sent = iflib_tx_encap = iflib_rx_allocs =
		iflib_fl_refills = iflib_fl_refills_large = iflib_tx_frees =
		iflib_txq_drain_flushing = iflib_txq_drain_oactive =
		iflib_txq_drain_notready =
		iflib_encap_load_mbuf_fail = iflib_encap_pad_mbuf_fail =
		iflib_encap_txq_avail_fail = iflib_encap_txd_encap_fail =
		iflib_task_fn_rxs = iflib_rx_intr_enables = iflib_fast_intrs =
		iflib_rx_unavail =
		iflib_rx_ctx_inactive = iflib_rx_if_input =
		iflib_rxd_flush = 0;
}

#else
#define DBG_COUNTER_INC(name)
static void iflib_debug_reset(void) {}
#endif

#define IFLIB_DEBUG 0

static void iflib_tx_structures_free(if_ctx_t ctx);
static void iflib_rx_structures_free(if_ctx_t ctx);
static int iflib_queues_alloc(if_ctx_t ctx);
static int iflib_tx_credits_update(if_ctx_t ctx, iflib_txq_t txq);
static int iflib_rxd_avail(if_ctx_t ctx, iflib_rxq_t rxq, qidx_t cidx, qidx_t budget);
static int iflib_qset_structures_setup(if_ctx_t ctx);
static int iflib_msix_init(if_ctx_t ctx);
static int iflib_legacy_setup(if_ctx_t ctx, driver_filter_t filter, void *filterarg, int *rid, const char *str);
static void iflib_txq_check_drain(iflib_txq_t txq, int budget);
static uint32_t iflib_txq_can_drain(struct ifmp_ring *);
#ifdef ALTQ
static void iflib_altq_if_start(if_t ifp);
static int iflib_altq_if_transmit(if_t ifp, struct mbuf *m);
#endif
static void iflib_register(if_ctx_t);
static void iflib_deregister(if_ctx_t);
static void iflib_unregister_vlan_handlers(if_ctx_t ctx);
static uint16_t iflib_get_mbuf_size_for(unsigned int size);
static void iflib_init_locked(if_ctx_t ctx);
static void iflib_add_device_sysctl_pre(if_ctx_t ctx);
static void iflib_add_device_sysctl_post(if_ctx_t ctx);
static void iflib_ifmp_purge(iflib_txq_t txq);
static void _iflib_pre_assert(if_softc_ctx_t scctx);
static void iflib_stop(if_ctx_t ctx);
static void iflib_if_init_locked(if_ctx_t ctx);
static void iflib_free_intr_mem(if_ctx_t ctx);
#ifndef __NO_STRICT_ALIGNMENT
static struct mbuf *iflib_fixup_rx(struct mbuf *m);
#endif
static __inline int iflib_completed_tx_reclaim(iflib_txq_t txq,
    struct mbuf **m_defer);
static __inline void iflib_completed_tx_reclaim_force(iflib_txq_t txq);

static SLIST_HEAD(cpu_offset_list, cpu_offset) cpu_offsets =
    SLIST_HEAD_INITIALIZER(cpu_offsets);
struct cpu_offset {
	SLIST_ENTRY(cpu_offset) entries;
	cpuset_t	set;
	unsigned int	refcount;
	uint16_t	next_cpuid;
};
static struct mtx cpu_offset_mtx;
MTX_SYSINIT(iflib_cpu_offset, &cpu_offset_mtx, "iflib_cpu_offset lock",
    MTX_DEF);

DEBUGNET_DEFINE(iflib);

static int
iflib_num_rx_descs(if_ctx_t ctx)
{
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	uint16_t first_rxq = (sctx->isc_flags & IFLIB_HAS_RXCQ) ? 1 : 0;

	return (scctx->isc_nrxd[first_rxq]);
}

static int
iflib_num_tx_descs(if_ctx_t ctx)
{
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	uint16_t first_txq = (sctx->isc_flags & IFLIB_HAS_TXCQ) ? 1 : 0;

	return (scctx->isc_ntxd[first_txq]);
}

#ifdef DEV_NETMAP
#include <sys/selinfo.h>
#include <net/netmap.h>
#include <dev/netmap/netmap_kern.h>

MODULE_DEPEND(iflib, netmap, 1, 1, 1);

static int netmap_fl_refill(iflib_rxq_t rxq, struct netmap_kring *kring, bool init);
static void iflib_netmap_timer(void *arg);

/*
 * device-specific sysctl variables:
 *
 * iflib_crcstrip: 0: keep CRC in rx frames (default), 1: strip it.
 *	During regular operations the CRC is stripped, but on some
 *	hardware reception of frames not multiple of 64 is slower,
 *	so using crcstrip=0 helps in benchmarks.
 *
 * iflib_rx_miss, iflib_rx_miss_bufs:
 *	count packets that might be missed due to lost interrupts.
 */
SYSCTL_DECL(_dev_netmap);
/*
 * The xl driver by default strips CRCs and we do not override it.
 */

int iflib_crcstrip = 1;
SYSCTL_INT(_dev_netmap, OID_AUTO, iflib_crcstrip,
    CTLFLAG_RW, &iflib_crcstrip, 1, "strip CRC on RX frames");

int iflib_rx_miss, iflib_rx_miss_bufs;
SYSCTL_INT(_dev_netmap, OID_AUTO, iflib_rx_miss,
    CTLFLAG_RW, &iflib_rx_miss, 0, "potentially missed RX intr");
SYSCTL_INT(_dev_netmap, OID_AUTO, iflib_rx_miss_bufs,
    CTLFLAG_RW, &iflib_rx_miss_bufs, 0, "potentially missed RX intr bufs");

/*
 * Register/unregister. We are already under netmap lock.
 * Only called on the first register or the last unregister.
 */
static int
iflib_netmap_register(struct netmap_adapter *na, int onoff)
{
	if_t ifp = na->ifp;
	if_ctx_t ctx = if_getsoftc(ifp);
	int status;

	CTX_LOCK(ctx);
	if (!CTX_IS_VF(ctx))
		IFDI_CRCSTRIP_SET(ctx, onoff, iflib_crcstrip);

	iflib_stop(ctx);

	/*
	 * Enable (or disable) netmap flags, and intercept (or restore)
	 * ifp->if_transmit. This is done once the device has been stopped
	 * to prevent race conditions. Also, this must be done after
	 * calling netmap_disable_all_rings() and before calling
	 * netmap_enable_all_rings(), so that these two functions see the
	 * updated state of the NAF_NETMAP_ON bit.
	 */
	if (onoff) {
		nm_set_native_flags(na);
	} else {
		nm_clear_native_flags(na);
	}

	iflib_init_locked(ctx);
	IFDI_CRCSTRIP_SET(ctx, onoff, iflib_crcstrip); // XXX why twice ?
	status = if_getdrvflags(ifp) & IFF_DRV_RUNNING ? 0 : 1;
	if (status)
		nm_clear_native_flags(na);
	CTX_UNLOCK(ctx);
	return (status);
}

static int
iflib_netmap_config(struct netmap_adapter *na, struct nm_config_info *info)
{
	if_t ifp = na->ifp;
	if_ctx_t ctx = if_getsoftc(ifp);
	iflib_rxq_t rxq = &ctx->ifc_rxqs[0];
	iflib_fl_t fl = &rxq->ifr_fl[0];

	info->num_tx_rings = ctx->ifc_softc_ctx.isc_ntxqsets;
	info->num_rx_rings = ctx->ifc_softc_ctx.isc_nrxqsets;
	info->num_tx_descs = iflib_num_tx_descs(ctx);
	info->num_rx_descs = iflib_num_rx_descs(ctx);
	info->rx_buf_maxsize = fl->ifl_buf_size;
	nm_prinf("txr %u rxr %u txd %u rxd %u rbufsz %u",
		info->num_tx_rings, info->num_rx_rings, info->num_tx_descs,
		info->num_rx_descs, info->rx_buf_maxsize);

	return (0);
}

static int
netmap_fl_refill(iflib_rxq_t rxq, struct netmap_kring *kring, bool init)
{
	struct netmap_adapter *na = kring->na;
	u_int const lim = kring->nkr_num_slots - 1;
	struct netmap_ring *ring = kring->ring;
	bus_dmamap_t *map;
	struct if_rxd_update iru;
	if_ctx_t ctx = rxq->ifr_ctx;
	iflib_fl_t fl = &rxq->ifr_fl[0];
	u_int nic_i_first, nic_i;
	u_int nm_i;
	int i, n;
#if IFLIB_DEBUG_COUNTERS
	int rf_count = 0;
#endif

	/*
	 * This function is used both at initialization and in rxsync.
	 * At initialization we need to prepare (with isc_rxd_refill())
	 * all the netmap buffers currently owned by the kernel, in
	 * such a way to keep fl->ifl_pidx and kring->nr_hwcur in sync
	 * (except for kring->nkr_hwofs). These may be less than
	 * kring->nkr_num_slots if netmap_reset() was called while
	 * an application using the kring that still owned some
	 * buffers.
	 * At rxsync time, both indexes point to the next buffer to be
	 * refilled.
	 * In any case we publish (with isc_rxd_flush()) up to
	 * (fl->ifl_pidx - 1) % N (included), to avoid the NIC tail/prod
	 * pointer to overrun the head/cons pointer, although this is
	 * not necessary for some NICs (e.g. vmx).
	 */
	if (__predict_false(init)) {
		n = kring->nkr_num_slots - nm_kr_rxspace(kring);
	} else {
		n = kring->rhead - kring->nr_hwcur;
		if (n == 0)
			return (0); /* Nothing to do. */
		if (n < 0)
			n += kring->nkr_num_slots;
	}

	iru_init(&iru, rxq, 0 /* flid */);
	map = fl->ifl_sds.ifsd_map;
	nic_i = fl->ifl_pidx;
	nm_i = netmap_idx_n2k(kring, nic_i);
	if (__predict_false(init)) {
		/*
		 * On init/reset, nic_i must be 0, and we must
		 * start to refill from hwtail (see netmap_reset()).
		 */
		MPASS(nic_i == 0);
		MPASS(nm_i == kring->nr_hwtail);
	} else
		MPASS(nm_i == kring->nr_hwcur);
	DBG_COUNTER_INC(fl_refills);
	while (n > 0) {
#if IFLIB_DEBUG_COUNTERS
		if (++rf_count == 9)
			DBG_COUNTER_INC(fl_refills_large);
#endif
		nic_i_first = nic_i;
		for (i = 0; n > 0 && i < IFLIB_MAX_RX_REFRESH; n--, i++) {
			struct netmap_slot *slot = &ring->slot[nm_i];
			uint64_t paddr;
			void *addr = PNMB(na, slot, &paddr);

			MPASS(i < IFLIB_MAX_RX_REFRESH);

			if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
				return (netmap_ring_reinit(kring));

			fl->ifl_bus_addrs[i] = paddr +
			    nm_get_offset(kring, slot);
			fl->ifl_rxd_idxs[i] = nic_i;

			if (__predict_false(init)) {
				netmap_load_map(na, fl->ifl_buf_tag,
				    map[nic_i], addr);
			} else if (slot->flags & NS_BUF_CHANGED) {
				/* buffer has changed, reload map */
				netmap_reload_map(na, fl->ifl_buf_tag,
				    map[nic_i], addr);
			}
			bus_dmamap_sync(fl->ifl_buf_tag, map[nic_i],
			    BUS_DMASYNC_PREREAD);
			slot->flags &= ~NS_BUF_CHANGED;

			nm_i = nm_next(nm_i, lim);
			nic_i = nm_next(nic_i, lim);
		}

		iru.iru_pidx = nic_i_first;
		iru.iru_count = i;
		ctx->isc_rxd_refill(ctx->ifc_softc, &iru);
	}
	fl->ifl_pidx = nic_i;
	/*
	 * At the end of the loop we must have refilled everything
	 * we could possibly refill.
	 */
	MPASS(nm_i == kring->rhead);
	kring->nr_hwcur = nm_i;

	bus_dmamap_sync(fl->ifl_ifdi->idi_tag, fl->ifl_ifdi->idi_map,
	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
	ctx->isc_rxd_flush(ctx->ifc_softc, rxq->ifr_id, fl->ifl_id,
	    nm_prev(nic_i, lim));
	DBG_COUNTER_INC(rxd_flush);

	return (0);
}

#define NETMAP_TX_TIMER_US	90

/*
 * Reconcile kernel and user view of the transmit ring.
 *
 * All information is in the kring.
 * Userspace wants to send packets up to the one before kring->rhead,
 * kernel knows kring->nr_hwcur is the first unsent packet.
 *
 * Here we push packets out (as many as possible), and possibly
 * reclaim buffers from previously completed transmission.
 *
 * The caller (netmap) guarantees that there is only one instance
 * running at any time. Any interference with other driver
 * methods should be handled by the individual drivers.
 */
static int
iflib_netmap_txsync(struct netmap_kring *kring, int flags)
{
	struct netmap_adapter *na = kring->na;
	if_t ifp = na->ifp;
	struct netmap_ring *ring = kring->ring;
	u_int nm_i;	/* index into the netmap kring */
	u_int nic_i;	/* index into the NIC ring */
	u_int const lim = kring->nkr_num_slots - 1;
	u_int const head = kring->rhead;
	struct if_pkt_info pi;
	int tx_pkts = 0, tx_bytes = 0;

	/*
	 * interrupts on every tx packet are expensive so request
	 * them every half ring, or where NS_REPORT is set
	 */
	u_int report_frequency = kring->nkr_num_slots >> 1;
	/* device-specific */
	if_ctx_t ctx = if_getsoftc(ifp);
	iflib_txq_t txq = &ctx->ifc_txqs[kring->ring_id];

	bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
	    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);

	/*
	 * First part: process new packets to send.
	 * nm_i is the current index in the netmap kring,
	 * nic_i is the corresponding index in the NIC ring.
	 *
	 * If we have packets to send (nm_i != head)
	 * iterate over the netmap ring, fetch length and update
	 * the corresponding slot in the NIC ring. Some drivers also
	 * need to update the buffer's physical address in the NIC slot
	 * even NS_BUF_CHANGED is not set (PNMB computes the addresses).
	 *
	 * The netmap_reload_map() calls is especially expensive,
	 * even when (as in this case) the tag is 0, so do only
	 * when the buffer has actually changed.
	 *
	 * If possible do not set the report/intr bit on all slots,
	 * but only a few times per ring or when NS_REPORT is set.
	 *
	 * Finally, on 10G and faster drivers, it might be useful
	 * to prefetch the next slot and txr entry.
	 */

	nm_i = kring->nr_hwcur;
	if (nm_i != head) {	/* we have new packets to send */
		uint32_t pkt_len = 0, seg_idx = 0;
		int nic_i_start = -1, flags = 0;
		memset(&pi, 0, sizeof(pi));
		pi.ipi_segs = txq->ift_segs;
		pi.ipi_qsidx = kring->ring_id;
		nic_i = netmap_idx_k2n(kring, nm_i);

		__builtin_prefetch(&ring->slot[nm_i]);
		__builtin_prefetch(&txq->ift_sds.ifsd_m[nic_i]);
		__builtin_prefetch(&txq->ift_sds.ifsd_map[nic_i]);

		while (nm_i != head) {
			struct netmap_slot *slot = &ring->slot[nm_i];
			uint64_t offset = nm_get_offset(kring, slot);
			u_int len = slot->len;
			uint64_t paddr;
			void *addr = PNMB(na, slot, &paddr);

			flags |= (slot->flags & NS_REPORT ||
				nic_i == 0 || nic_i == report_frequency) ?
				IPI_TX_INTR : 0;

			/*
			 * If this is the first packet fragment, save the
			 * index of the first NIC slot for later.
			 */
			if (nic_i_start < 0)
				nic_i_start = nic_i;

			pi.ipi_segs[seg_idx].ds_addr = paddr + offset;
			pi.ipi_segs[seg_idx].ds_len = len;
			if (len) {
				pkt_len += len;
				seg_idx++;
			}

			if (!(slot->flags & NS_MOREFRAG)) {
				pi.ipi_len = pkt_len;
				pi.ipi_nsegs = seg_idx;
				pi.ipi_pidx = nic_i_start;
				pi.ipi_ndescs = 0;
				pi.ipi_flags = flags;

				/* Prepare the NIC TX ring. */
				ctx->isc_txd_encap(ctx->ifc_softc, &pi);
				DBG_COUNTER_INC(tx_encap);

				/* Update transmit counters */
				tx_bytes += pi.ipi_len;
				tx_pkts++;

				/* Reinit per-packet info for the next one. */
				flags = seg_idx = pkt_len = 0;
				nic_i_start = -1;
			}

			/* prefetch for next round */
			__builtin_prefetch(&ring->slot[nm_i + 1]);
			__builtin_prefetch(&txq->ift_sds.ifsd_m[nic_i + 1]);
			__builtin_prefetch(&txq->ift_sds.ifsd_map[nic_i + 1]);

			NM_CHECK_ADDR_LEN_OFF(na, len, offset);

			if (slot->flags & NS_BUF_CHANGED) {
				/* buffer has changed, reload map */
				netmap_reload_map(na, txq->ift_buf_tag,
				    txq->ift_sds.ifsd_map[nic_i], addr);
			}
			/* make sure changes to the buffer are synced */
			bus_dmamap_sync(txq->ift_buf_tag,
			    txq->ift_sds.ifsd_map[nic_i],
			    BUS_DMASYNC_PREWRITE);

			slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED | NS_MOREFRAG);
			nm_i = nm_next(nm_i, lim);
			nic_i = nm_next(nic_i, lim);
		}
		kring->nr_hwcur = nm_i;

		/* synchronize the NIC ring */
		bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);

		/* (re)start the tx unit up to slot nic_i (excluded) */
		ctx->isc_txd_flush(ctx->ifc_softc, txq->ift_id, nic_i);
	}

	/*
	 * Second part: reclaim buffers for completed transmissions.
	 *
	 * If there are unclaimed buffers, attempt to reclaim them.
	 * If we don't manage to reclaim them all, and TX IRQs are not in use,
	 * trigger a per-tx-queue timer to try again later.
	 */
	if (kring->nr_hwtail != nm_prev(kring->nr_hwcur, lim)) {
		if (iflib_tx_credits_update(ctx, txq)) {
			/* some tx completed, increment avail */
			nic_i = txq->ift_cidx_processed;
			kring->nr_hwtail = nm_prev(netmap_idx_n2k(kring, nic_i), lim);
		}
	}

	if (!(ctx->ifc_flags & IFC_NETMAP_TX_IRQ))
		if (kring->nr_hwtail != nm_prev(kring->nr_hwcur, lim)) {
			callout_reset_sbt_on(&txq->ift_netmap_timer,
			    NETMAP_TX_TIMER_US * SBT_1US, SBT_1US,
			    iflib_netmap_timer, txq,
			    txq->ift_netmap_timer.c_cpu, 0);
		}

	if_inc_counter(ifp, IFCOUNTER_OBYTES, tx_bytes);
	if_inc_counter(ifp, IFCOUNTER_OPACKETS, tx_pkts);

	return (0);
}

/*
 * Reconcile kernel and user view of the receive ring.
 * Same as for the txsync, this routine must be efficient.
 * The caller guarantees a single invocations, but races against
 * the rest of the driver should be handled here.
 *
 * On call, kring->rhead is the first packet that userspace wants
 * to keep, and kring->rcur is the wakeup point.
 * The kernel has previously reported packets up to kring->rtail.
 *
 * If (flags & NAF_FORCE_READ) also check for incoming packets irrespective
 * of whether or not we received an interrupt.
 */
static int
iflib_netmap_rxsync(struct netmap_kring *kring, int flags)
{
	struct netmap_adapter *na = kring->na;
	struct netmap_ring *ring = kring->ring;
	if_t ifp = na->ifp;
	uint32_t nm_i;	/* index into the netmap ring */
	uint32_t nic_i;	/* index into the NIC ring */
	u_int n;
	u_int const lim = kring->nkr_num_slots - 1;
	int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR;
	int i = 0, rx_bytes = 0, rx_pkts = 0;

	if_ctx_t ctx = if_getsoftc(ifp);
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	iflib_rxq_t rxq = &ctx->ifc_rxqs[kring->ring_id];
	iflib_fl_t fl = &rxq->ifr_fl[0];
	struct if_rxd_info ri;
	qidx_t *cidxp;

	/*
	 * netmap only uses free list 0, to avoid out of order consumption
	 * of receive buffers
	 */

	bus_dmamap_sync(fl->ifl_ifdi->idi_tag, fl->ifl_ifdi->idi_map,
	    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);

	/*
	 * First part: import newly received packets.
	 *
	 * nm_i is the index of the next free slot in the netmap ring,
	 * nic_i is the index of the next received packet in the NIC ring
	 * (or in the free list 0 if IFLIB_HAS_RXCQ is set), and they may
	 * differ in case if_init() has been called while
	 * in netmap mode. For the receive ring we have
	 *
	 *	nic_i = fl->ifl_cidx;
	 *	nm_i = kring->nr_hwtail (previous)
	 * and
	 *	nm_i == (nic_i + kring->nkr_hwofs) % ring_size
	 *
	 * fl->ifl_cidx is set to 0 on a ring reinit
	 */
	if (netmap_no_pendintr || force_update) {
		uint32_t hwtail_lim = nm_prev(kring->nr_hwcur, lim);
		bool have_rxcq = sctx->isc_flags & IFLIB_HAS_RXCQ;
		int crclen = iflib_crcstrip ? 0 : 4;
		int error, avail;

		/*
		 * For the free list consumer index, we use the same
		 * logic as in iflib_rxeof().
		 */
		if (have_rxcq)
			cidxp = &rxq->ifr_cq_cidx;
		else
			cidxp = &fl->ifl_cidx;
		avail = ctx->isc_rxd_available(ctx->ifc_softc,
		    rxq->ifr_id, *cidxp, USHRT_MAX);

		nic_i = fl->ifl_cidx;
		nm_i = netmap_idx_n2k(kring, nic_i);
		MPASS(nm_i == kring->nr_hwtail);
		for (n = 0; avail > 0 && nm_i != hwtail_lim; n++, avail--) {
			memset(&ri, 0, sizeof(ri));
			ri.iri_frags = rxq->ifr_frags;
			ri.iri_qsidx = kring->ring_id;
			ri.iri_ifp = ctx->ifc_ifp;
			ri.iri_cidx = *cidxp;

			error = ctx->isc_rxd_pkt_get(ctx->ifc_softc, &ri);
			for (i = 0; i < ri.iri_nfrags; i++) {
				if (error) {
					ring->slot[nm_i].len = 0;
					ring->slot[nm_i].flags = 0;
				} else {
					ring->slot[nm_i].len = ri.iri_frags[i].irf_len;
					if (i == (ri.iri_nfrags - 1)) {
						ring->slot[nm_i].len -= crclen;
						ring->slot[nm_i].flags = 0;

						/* Update receive counters */
						rx_bytes += ri.iri_len;
						rx_pkts++;
					} else
						ring->slot[nm_i].flags = NS_MOREFRAG;
				}

				bus_dmamap_sync(fl->ifl_buf_tag,
				    fl->ifl_sds.ifsd_map[nic_i], BUS_DMASYNC_POSTREAD);
				nm_i = nm_next(nm_i, lim);
				fl->ifl_cidx = nic_i = nm_next(nic_i, lim);
			}

			if (have_rxcq) {
				*cidxp = ri.iri_cidx;
				while (*cidxp >= scctx->isc_nrxd[0])
					*cidxp -= scctx->isc_nrxd[0];
			}

		}
		if (n) { /* update the state variables */
			if (netmap_no_pendintr && !force_update) {
				/* diagnostics */
				iflib_rx_miss++;
				iflib_rx_miss_bufs += n;
			}
			kring->nr_hwtail = nm_i;
		}
		kring->nr_kflags &= ~NKR_PENDINTR;
	}
	/*
	 * Second part: skip past packets that userspace has released.
	 * (kring->nr_hwcur to head excluded),
	 * and make the buffers available for reception.
	 * As usual nm_i is the index in the netmap ring,
	 * nic_i is the index in the NIC ring, and
	 * nm_i == (nic_i + kring->nkr_hwofs) % ring_size
	 */
	netmap_fl_refill(rxq, kring, false);

	if_inc_counter(ifp, IFCOUNTER_IBYTES, rx_bytes);
	if_inc_counter(ifp, IFCOUNTER_IPACKETS, rx_pkts);

	return (0);
}

static void
iflib_netmap_intr(struct netmap_adapter *na, int onoff)
{
	if_ctx_t ctx = if_getsoftc(na->ifp);

	CTX_LOCK(ctx);
	if (onoff) {
		IFDI_INTR_ENABLE(ctx);
	} else {
		IFDI_INTR_DISABLE(ctx);
	}
	CTX_UNLOCK(ctx);
}

static int
iflib_netmap_attach(if_ctx_t ctx)
{
	struct netmap_adapter na;

	bzero(&na, sizeof(na));

	na.ifp = ctx->ifc_ifp;
	na.na_flags = NAF_BDG_MAYSLEEP | NAF_MOREFRAG | NAF_OFFSETS;
	MPASS(ctx->ifc_softc_ctx.isc_ntxqsets);
	MPASS(ctx->ifc_softc_ctx.isc_nrxqsets);

	na.num_tx_desc = iflib_num_tx_descs(ctx);
	na.num_rx_desc = iflib_num_rx_descs(ctx);
	na.nm_txsync = iflib_netmap_txsync;
	na.nm_rxsync = iflib_netmap_rxsync;
	na.nm_register = iflib_netmap_register;
	na.nm_intr = iflib_netmap_intr;
	na.nm_config = iflib_netmap_config;
	na.num_tx_rings = ctx->ifc_softc_ctx.isc_ntxqsets;
	na.num_rx_rings = ctx->ifc_softc_ctx.isc_nrxqsets;
	return (netmap_attach(&na));
}

static int
iflib_netmap_txq_init(if_ctx_t ctx, iflib_txq_t txq)
{
	struct netmap_adapter *na = NA(ctx->ifc_ifp);
	struct netmap_slot *slot;

	slot = netmap_reset(na, NR_TX, txq->ift_id, 0);
	if (slot == NULL)
		return (0);
	for (int i = 0; i < ctx->ifc_softc_ctx.isc_ntxd[0]; i++) {
		/*
		 * In netmap mode, set the map for the packet buffer.
		 * NOTE: Some drivers (not this one) also need to set
		 * the physical buffer address in the NIC ring.
		 * netmap_idx_n2k() maps a nic index, i, into the corresponding
		 * netmap slot index, si
		 */
		int si = netmap_idx_n2k(na->tx_rings[txq->ift_id], i);
		netmap_load_map(na, txq->ift_buf_tag, txq->ift_sds.ifsd_map[i],
		    NMB(na, slot + si));
	}
	return (1);
}

static int
iflib_netmap_rxq_init(if_ctx_t ctx, iflib_rxq_t rxq)
{
	struct netmap_adapter *na = NA(ctx->ifc_ifp);
	struct netmap_kring *kring;
	struct netmap_slot *slot;

	slot = netmap_reset(na, NR_RX, rxq->ifr_id, 0);
	if (slot == NULL)
		return (0);
	kring = na->rx_rings[rxq->ifr_id];
	netmap_fl_refill(rxq, kring, true);
	return (1);
}

static void
iflib_netmap_timer(void *arg)
{
	iflib_txq_t txq = arg;
	if_ctx_t ctx = txq->ift_ctx;

	/*
	 * Wake up the netmap application, to give it a chance to
	 * call txsync and reclaim more completed TX buffers.
	 */
	netmap_tx_irq(ctx->ifc_ifp, txq->ift_id);
}

#define iflib_netmap_detach(ifp) netmap_detach(ifp)

#else
#define iflib_netmap_txq_init(ctx, txq) (0)
#define iflib_netmap_rxq_init(ctx, rxq) (0)
#define iflib_netmap_detach(ifp)
#define netmap_enable_all_rings(ifp)
#define netmap_disable_all_rings(ifp)

#define iflib_netmap_attach(ctx) (0)
#define netmap_rx_irq(ifp, qid, budget) (0)
#endif

#if defined(__i386__) || defined(__amd64__)
static __inline void
prefetch(void *x)
{
	__asm volatile("prefetcht0 %0" :: "m" (*(unsigned long *)x));
}

static __inline void
prefetch2cachelines(void *x)
{
	__asm volatile("prefetcht0 %0" :: "m" (*(unsigned long *)x));
#if (CACHE_LINE_SIZE < 128)
	__asm volatile("prefetcht0 %0" :: "m" (*(((unsigned long *)x) + CACHE_LINE_SIZE / (sizeof(unsigned long)))));
#endif
}
#else
static __inline void
prefetch(void *x)
{
}

static __inline void
prefetch2cachelines(void *x)
{
}
#endif

static void
iru_init(if_rxd_update_t iru, iflib_rxq_t rxq, uint8_t flid)
{
	iflib_fl_t fl;

	fl = &rxq->ifr_fl[flid];
	iru->iru_paddrs = fl->ifl_bus_addrs;
	iru->iru_idxs = fl->ifl_rxd_idxs;
	iru->iru_qsidx = rxq->ifr_id;
	iru->iru_buf_size = fl->ifl_buf_size;
	iru->iru_flidx = fl->ifl_id;
}

static void
_iflib_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg, int err)
{
	if (err)
		return;
	*(bus_addr_t *) arg = segs[0].ds_addr;
}

#define	DMA_WIDTH_TO_BUS_LOWADDR(width)				\
	(((width) == 0) || (width) == flsll(BUS_SPACE_MAXADDR) ?	\
	    BUS_SPACE_MAXADDR : (1ULL << (width)) - 1ULL)

int
iflib_dma_alloc_align(if_ctx_t ctx, int size, int align, iflib_dma_info_t dma, int mapflags)
{
	int err;
	device_t dev = ctx->ifc_dev;
	bus_addr_t lowaddr;

	lowaddr = DMA_WIDTH_TO_BUS_LOWADDR(ctx->ifc_softc_ctx.isc_dma_width);

	err = bus_dma_tag_create(bus_get_dma_tag(dev),	/* parent */
		    align, 0,		/* alignment, bounds */
		    lowaddr,		/* lowaddr */
		    BUS_SPACE_MAXADDR,	/* highaddr */
		    NULL, NULL,		/* filter, filterarg */
		    size,		/* maxsize */
		    1,			/* nsegments */
		    size,		/* maxsegsize */
		    BUS_DMA_ALLOCNOW,	/* flags */
		    NULL,		/* lockfunc */
		    NULL,		/* lockarg */
		    &dma->idi_tag);
	if (err) {
		device_printf(dev,
		    "%s: bus_dma_tag_create failed: %d (size=%d, align=%d)\n",
		    __func__, err, size, align);
		goto fail_0;
	}

	err = bus_dmamem_alloc(dma->idi_tag, (void **)&dma->idi_vaddr,
	    BUS_DMA_NOWAIT | BUS_DMA_COHERENT | BUS_DMA_ZERO, &dma->idi_map);
	if (err) {
		device_printf(dev,
		    "%s: bus_dmamem_alloc(%ju) failed: %d\n",
		    __func__, (uintmax_t)size, err);
		goto fail_1;
	}

	dma->idi_paddr = IF_BAD_DMA;
	err = bus_dmamap_load(dma->idi_tag, dma->idi_map, dma->idi_vaddr,
	    size, _iflib_dmamap_cb, &dma->idi_paddr, mapflags | BUS_DMA_NOWAIT);
	if (err || dma->idi_paddr == IF_BAD_DMA) {
		device_printf(dev,
		    "%s: bus_dmamap_load failed: %d\n",
		    __func__, err);
		goto fail_2;
	}

	dma->idi_size = size;
	return (0);

fail_2:
	bus_dmamem_free(dma->idi_tag, dma->idi_vaddr, dma->idi_map);
fail_1:
	bus_dma_tag_destroy(dma->idi_tag);
fail_0:
	dma->idi_tag = NULL;

	return (err);
}

int
iflib_dma_alloc(if_ctx_t ctx, int size, iflib_dma_info_t dma, int mapflags)
{
	if_shared_ctx_t sctx = ctx->ifc_sctx;

	KASSERT(sctx->isc_q_align != 0, ("alignment value not initialized"));

	return (iflib_dma_alloc_align(ctx, size, sctx->isc_q_align, dma, mapflags));
}

int
iflib_dma_alloc_multi(if_ctx_t ctx, int *sizes, iflib_dma_info_t *dmalist, int mapflags, int count)
{
	int i, err;
	iflib_dma_info_t *dmaiter;

	dmaiter = dmalist;
	for (i = 0; i < count; i++, dmaiter++) {
		if ((err = iflib_dma_alloc(ctx, sizes[i], *dmaiter, mapflags)) != 0)
			break;
	}
	if (err)
		iflib_dma_free_multi(dmalist, i);
	return (err);
}

void
iflib_dma_free(iflib_dma_info_t dma)
{
	if (dma->idi_tag == NULL)
		return;
	if (dma->idi_paddr != IF_BAD_DMA) {
		bus_dmamap_sync(dma->idi_tag, dma->idi_map,
		    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
		bus_dmamap_unload(dma->idi_tag, dma->idi_map);
		dma->idi_paddr = IF_BAD_DMA;
	}
	if (dma->idi_vaddr != NULL) {
		bus_dmamem_free(dma->idi_tag, dma->idi_vaddr, dma->idi_map);
		dma->idi_vaddr = NULL;
	}
	bus_dma_tag_destroy(dma->idi_tag);
	dma->idi_tag = NULL;
}

void
iflib_dma_free_multi(iflib_dma_info_t *dmalist, int count)
{
	int i;
	iflib_dma_info_t *dmaiter = dmalist;

	for (i = 0; i < count; i++, dmaiter++)
		iflib_dma_free(*dmaiter);
}

static int
iflib_fast_intr(void *arg)
{
	iflib_filter_info_t info = arg;
	struct grouptask *gtask = info->ifi_task;
	int result;

	DBG_COUNTER_INC(fast_intrs);
	if (info->ifi_filter != NULL) {
		result = info->ifi_filter(info->ifi_filter_arg);
		if ((result & FILTER_SCHEDULE_THREAD) == 0)
			return (result);
	}

	GROUPTASK_ENQUEUE(gtask);
	return (FILTER_HANDLED);
}

static int
iflib_fast_intr_rxtx(void *arg)
{
	iflib_filter_info_t info = arg;
	struct grouptask *gtask = info->ifi_task;
	if_ctx_t ctx;
	iflib_rxq_t rxq = (iflib_rxq_t)info->ifi_ctx;
	iflib_txq_t txq;
	void *sc;
	int i, cidx, result;
	qidx_t txqid;
	bool intr_enable, intr_legacy;

	DBG_COUNTER_INC(fast_intrs);
	if (info->ifi_filter != NULL) {
		result = info->ifi_filter(info->ifi_filter_arg);
		if ((result & FILTER_SCHEDULE_THREAD) == 0)
			return (result);
	}

	ctx = rxq->ifr_ctx;
	sc = ctx->ifc_softc;
	intr_enable = false;
	intr_legacy = !!(ctx->ifc_flags & IFC_LEGACY);
	MPASS(rxq->ifr_ntxqirq);
	for (i = 0; i < rxq->ifr_ntxqirq; i++) {
		txqid = rxq->ifr_txqid[i];
		txq = &ctx->ifc_txqs[txqid];
		bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
		    BUS_DMASYNC_POSTREAD);
		if (!ctx->isc_txd_credits_update(sc, txqid, false)) {
			if (intr_legacy)
				intr_enable = true;
			else
				IFDI_TX_QUEUE_INTR_ENABLE(ctx, txqid);
			continue;
		}
		GROUPTASK_ENQUEUE(&txq->ift_task);
	}
	if (ctx->ifc_sctx->isc_flags & IFLIB_HAS_RXCQ)
		cidx = rxq->ifr_cq_cidx;
	else
		cidx = rxq->ifr_fl[0].ifl_cidx;
	if (iflib_rxd_avail(ctx, rxq, cidx, 1))
		GROUPTASK_ENQUEUE(gtask);
	else {
		if (intr_legacy)
			intr_enable = true;
		else
			IFDI_RX_QUEUE_INTR_ENABLE(ctx, rxq->ifr_id);
		DBG_COUNTER_INC(rx_intr_enables);
	}
	if (intr_enable)
		IFDI_INTR_ENABLE(ctx);
	return (FILTER_HANDLED);
}

static int
iflib_fast_intr_ctx(void *arg)
{
	iflib_filter_info_t info = arg;
	if_ctx_t ctx = info->ifi_ctx;
	int result;

	DBG_COUNTER_INC(fast_intrs);
	if (info->ifi_filter != NULL) {
		result = info->ifi_filter(info->ifi_filter_arg);
		if ((result & FILTER_SCHEDULE_THREAD) == 0)
			return (result);
	}

	taskqueue_enqueue(ctx->ifc_tq, &ctx->ifc_admin_task);
	return (FILTER_HANDLED);
}

static int
_iflib_irq_alloc(if_ctx_t ctx, if_irq_t irq, int rid,
		 driver_filter_t filter, driver_intr_t handler, void *arg,
		 const char *name)
{
	struct resource *res;
	void *tag = NULL;
	device_t dev = ctx->ifc_dev;
	int flags, i, rc;

	flags = RF_ACTIVE;
	if (ctx->ifc_flags & IFC_LEGACY)
		flags |= RF_SHAREABLE;
	MPASS(rid < 512);
	i = rid;
	res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &i, flags);
	if (res == NULL) {
		device_printf(dev,
		    "failed to allocate IRQ for rid %d, name %s.\n", rid, name);
		return (ENOMEM);
	}
	irq->ii_res = res;
	KASSERT(filter == NULL || handler == NULL, ("filter and handler can't both be non-NULL"));
	rc = bus_setup_intr(dev, res, INTR_MPSAFE | INTR_TYPE_NET,
		    filter, handler, arg, &tag);
	if (rc != 0) {
		device_printf(dev,
		    "failed to setup interrupt for rid %d, name %s: %d\n",
		    rid, name ? name : "unknown", rc);
		return (rc);
	} else if (name)
		bus_describe_intr(dev, res, tag, "%s", name);

	irq->ii_tag = tag;
	return (0);
}

/*********************************************************************
 *
 *  Allocate DMA resources for TX buffers as well as memory for the TX
 *  mbuf map.  TX DMA maps (non-TSO/TSO) and TX mbuf map are kept in a
 *  iflib_sw_tx_desc_array structure, storing all the information that
 *  is needed to transmit a packet on the wire.  This is called only
 *  once at attach, setup is done every reset.
 *
 **********************************************************************/
static int
iflib_txsd_alloc(iflib_txq_t txq)
{
	if_ctx_t ctx = txq->ift_ctx;
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	device_t dev = ctx->ifc_dev;
	bus_size_t tsomaxsize;
	bus_addr_t lowaddr;
	int err, nsegments, ntsosegments;
	bool tso;

	nsegments = scctx->isc_tx_nsegments;
	ntsosegments = scctx->isc_tx_tso_segments_max;
	tsomaxsize = scctx->isc_tx_tso_size_max;
	if (if_getcapabilities(ctx->ifc_ifp) & IFCAP_VLAN_MTU)
		tsomaxsize += sizeof(struct ether_vlan_header);
	MPASS(scctx->isc_ntxd[0] > 0);
	MPASS(scctx->isc_ntxd[txq->ift_br_offset] > 0);
	MPASS(nsegments > 0);
	if (if_getcapabilities(ctx->ifc_ifp) & IFCAP_TSO) {
		MPASS(ntsosegments > 0);
		MPASS(sctx->isc_tso_maxsize >= tsomaxsize);
	}

	lowaddr = DMA_WIDTH_TO_BUS_LOWADDR(scctx->isc_dma_width);

	/*
	 * Set up DMA tags for TX buffers.
	 */
	if ((err = bus_dma_tag_create(bus_get_dma_tag(dev),
		    1, 0,			/* alignment, bounds */
		    lowaddr,			/* lowaddr */
		    BUS_SPACE_MAXADDR,		/* highaddr */
		    NULL, NULL,			/* filter, filterarg */
		    sctx->isc_tx_maxsize,	/* maxsize */
		    nsegments,			/* nsegments */
		    sctx->isc_tx_maxsegsize,	/* maxsegsize */
		    0,				/* flags */
		    NULL,			/* lockfunc */
		    NULL,			/* lockfuncarg */
		    &txq->ift_buf_tag))) {
		device_printf(dev, "Unable to allocate TX DMA tag: %d\n", err);
		device_printf(dev, "maxsize: %ju nsegments: %d maxsegsize: %ju\n",
		    (uintmax_t)sctx->isc_tx_maxsize, nsegments, (uintmax_t)sctx->isc_tx_maxsegsize);
		goto fail;
	}
	tso = (if_getcapabilities(ctx->ifc_ifp) & IFCAP_TSO) != 0;
	if (tso && (err = bus_dma_tag_create(bus_get_dma_tag(dev),
		    1, 0,			/* alignment, bounds */
		    lowaddr,			/* lowaddr */
		    BUS_SPACE_MAXADDR,		/* highaddr */
		    NULL, NULL,			/* filter, filterarg */
		    tsomaxsize,			/* maxsize */
		    ntsosegments,		/* nsegments */
		    sctx->isc_tso_maxsegsize,	/* maxsegsize */
		    0,				/* flags */
		    NULL,			/* lockfunc */
		    NULL,			/* lockfuncarg */
		    &txq->ift_tso_buf_tag))) {
		device_printf(dev, "Unable to allocate TSO TX DMA tag: %d\n",
		    err);
		goto fail;
	}

	/* Allocate memory for the TX mbuf map. */
	if (!(txq->ift_sds.ifsd_m =
	    (struct mbuf **) malloc(sizeof(struct mbuf *) *
	    scctx->isc_ntxd[txq->ift_br_offset], M_IFLIB, M_NOWAIT | M_ZERO))) {
		device_printf(dev, "Unable to allocate TX mbuf map memory\n");
		err = ENOMEM;
		goto fail;
	}
	if (ctx->ifc_sysctl_simple_tx) {
		if (!(txq->ift_sds.ifsd_m_defer =
			(struct mbuf **) malloc(sizeof(struct mbuf *) *
			    scctx->isc_ntxd[txq->ift_br_offset], M_IFLIB, M_NOWAIT | M_ZERO))) {
			device_printf(dev, "Unable to allocate TX mbuf map memory\n");
			err = ENOMEM;
			goto fail;
		}
	}
	txq->ift_sds.ifsd_m_deferb = txq->ift_sds.ifsd_m_defer;
	/*
	 * Create the DMA maps for TX buffers.
	 */
	if ((txq->ift_sds.ifsd_map = (bus_dmamap_t *)malloc(
	    sizeof(bus_dmamap_t) * scctx->isc_ntxd[txq->ift_br_offset],
	    M_IFLIB, M_NOWAIT | M_ZERO)) == NULL) {
		device_printf(dev,
		    "Unable to allocate TX buffer DMA map memory\n");
		err = ENOMEM;
		goto fail;
	}
	if (tso && (txq->ift_sds.ifsd_tso_map = (bus_dmamap_t *)malloc(
	    sizeof(bus_dmamap_t) * scctx->isc_ntxd[txq->ift_br_offset],
	    M_IFLIB, M_NOWAIT | M_ZERO)) == NULL) {
		device_printf(dev,
		    "Unable to allocate TSO TX buffer map memory\n");
		err = ENOMEM;
		goto fail;
	}
	for (int i = 0; i < scctx->isc_ntxd[txq->ift_br_offset]; i++) {
		err = bus_dmamap_create(txq->ift_buf_tag, 0,
		    &txq->ift_sds.ifsd_map[i]);
		if (err != 0) {
			device_printf(dev, "Unable to create TX DMA map\n");
			goto fail;
		}
		if (!tso)
			continue;
		err = bus_dmamap_create(txq->ift_tso_buf_tag, 0,
		    &txq->ift_sds.ifsd_tso_map[i]);
		if (err != 0) {
			device_printf(dev, "Unable to create TSO TX DMA map\n");
			goto fail;
		}
	}
	return (0);
fail:
	/* We free all, it handles case where we are in the middle */
	iflib_tx_structures_free(ctx);
	return (err);
}

static void
iflib_txsd_destroy(if_ctx_t ctx, iflib_txq_t txq, int i)
{
	bus_dmamap_t map;

	if (txq->ift_sds.ifsd_map != NULL) {
		map = txq->ift_sds.ifsd_map[i];
		bus_dmamap_sync(txq->ift_buf_tag, map, BUS_DMASYNC_POSTWRITE);
		bus_dmamap_unload(txq->ift_buf_tag, map);
		bus_dmamap_destroy(txq->ift_buf_tag, map);
		txq->ift_sds.ifsd_map[i] = NULL;
	}

	if (txq->ift_sds.ifsd_tso_map != NULL) {
		map = txq->ift_sds.ifsd_tso_map[i];
		bus_dmamap_sync(txq->ift_tso_buf_tag, map,
		    BUS_DMASYNC_POSTWRITE);
		bus_dmamap_unload(txq->ift_tso_buf_tag, map);
		bus_dmamap_destroy(txq->ift_tso_buf_tag, map);
		txq->ift_sds.ifsd_tso_map[i] = NULL;
	}
}

static void
iflib_txq_destroy(iflib_txq_t txq)
{
	if_ctx_t ctx = txq->ift_ctx;

	for (int i = 0; i < txq->ift_size; i++)
		iflib_txsd_destroy(ctx, txq, i);

	if (txq->ift_br != NULL) {
		ifmp_ring_free(txq->ift_br);
		txq->ift_br = NULL;
	}

	/* Free any mbufs stranded in the deferral ring	 */
	if (txq->ift_drbr != NULL) {
		mtx_lock(&txq->ift_mtx);
		drbr_flush(NULL, txq->ift_drbr);
		mtx_unlock(&txq->ift_mtx);
		buf_ring_free(txq->ift_drbr, M_IFLIB);
		txq->ift_drbr = NULL;
	}
	if (txq->ift_drbr_deferred != NULL) {
		counter_u64_free(txq->ift_drbr_deferred);
		txq->ift_drbr_deferred = NULL;
	}
	if (txq->ift_drbr_blocked != NULL) {
		counter_u64_free(txq->ift_drbr_blocked);
		txq->ift_drbr_blocked = NULL;
	}
	if (txq->ift_drbr_remote != NULL) {
		counter_u64_free(txq->ift_drbr_remote);
		txq->ift_drbr_remote = NULL;
	}
	if (txq->ift_drbr_drops != NULL) {
		counter_u64_free(txq->ift_drbr_drops);
		txq->ift_drbr_drops = NULL;
	}

	mtx_destroy(&txq->ift_mtx);

	if (txq->ift_sds.ifsd_map != NULL) {
		free(txq->ift_sds.ifsd_map, M_IFLIB);
		txq->ift_sds.ifsd_map = NULL;
	}
	if (txq->ift_sds.ifsd_tso_map != NULL) {
		free(txq->ift_sds.ifsd_tso_map, M_IFLIB);
		txq->ift_sds.ifsd_tso_map = NULL;
	}
	if (txq->ift_sds.ifsd_m != NULL) {
		free(txq->ift_sds.ifsd_m, M_IFLIB);
		txq->ift_sds.ifsd_m = NULL;
	}
	if (txq->ift_sds.ifsd_m_defer != NULL) {
		free(txq->ift_sds.ifsd_m_defer, M_IFLIB);
		txq->ift_sds.ifsd_m_defer = NULL;
	}
	if (txq->ift_buf_tag != NULL) {
		bus_dma_tag_destroy(txq->ift_buf_tag);
		txq->ift_buf_tag = NULL;
	}
	if (txq->ift_tso_buf_tag != NULL) {
		bus_dma_tag_destroy(txq->ift_tso_buf_tag);
		txq->ift_tso_buf_tag = NULL;
	}
	if (txq->ift_ifdi != NULL) {
		free(txq->ift_ifdi, M_IFLIB);
	}
}

static void
iflib_txsd_free(if_ctx_t ctx, iflib_txq_t txq, int i)
{
	struct mbuf *m;

	m = IFLIB_GET_MBUF(txq->ift_sds.ifsd_m[i]);
	if (m == NULL)
		return;

	if (txq->ift_sds.ifsd_map != NULL) {
		bus_dmamap_sync(txq->ift_buf_tag,
		    txq->ift_sds.ifsd_map[i], BUS_DMASYNC_POSTWRITE);
		bus_dmamap_unload(txq->ift_buf_tag, txq->ift_sds.ifsd_map[i]);
	}
	if (txq->ift_sds.ifsd_tso_map != NULL) {
		bus_dmamap_sync(txq->ift_tso_buf_tag,
		    txq->ift_sds.ifsd_tso_map[i], BUS_DMASYNC_POSTWRITE);
		bus_dmamap_unload(txq->ift_tso_buf_tag,
		    txq->ift_sds.ifsd_tso_map[i]);
	}
	txq->ift_sds.ifsd_m[i] = NULL;
	m_freem(m);
	DBG_COUNTER_INC(tx_frees);
}

static int
iflib_txq_setup(iflib_txq_t txq)
{
	if_ctx_t ctx = txq->ift_ctx;
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	iflib_dma_info_t di;
	int i;

	/* XXX make configurable */
	txq->ift_update_freq = IFLIB_DEFAULT_TX_UPDATE_FREQ;

	/* Reset indices */
	txq->ift_cidx_processed = 0;
	txq->ift_pidx = txq->ift_cidx = txq->ift_npending = 0;
	txq->ift_size = scctx->isc_ntxd[txq->ift_br_offset];
	txq->ift_pad = scctx->isc_tx_pad;

	for (i = 0, di = txq->ift_ifdi; i < sctx->isc_ntxqs; i++, di++)
		bzero((void *)di->idi_vaddr, di->idi_size);

	IFDI_TXQ_SETUP(ctx, txq->ift_id);
	for (i = 0, di = txq->ift_ifdi; i < sctx->isc_ntxqs; i++, di++)
		bus_dmamap_sync(di->idi_tag, di->idi_map,
		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
	return (0);
}

/*********************************************************************
 *
 *  Allocate DMA resources for RX buffers as well as memory for the RX
 *  mbuf map, direct RX cluster pointer map and RX cluster bus address
 *  map.  RX DMA map, RX mbuf map, direct RX cluster pointer map and
 *  RX cluster map are kept in a iflib_sw_rx_desc_array structure.
 *  Since we use use one entry in iflib_sw_rx_desc_array per received
 *  packet, the maximum number of entries we'll need is equal to the
 *  number of hardware receive descriptors that we've allocated.
 *
 **********************************************************************/
static int
iflib_rxsd_alloc(iflib_rxq_t rxq)
{
	if_ctx_t ctx = rxq->ifr_ctx;
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	device_t dev = ctx->ifc_dev;
	iflib_fl_t fl;
	bus_addr_t lowaddr;
	int err;

	MPASS(scctx->isc_nrxd[0] > 0);
	MPASS(scctx->isc_nrxd[rxq->ifr_fl_offset] > 0);

	lowaddr = DMA_WIDTH_TO_BUS_LOWADDR(scctx->isc_dma_width);

	fl = rxq->ifr_fl;
	for (int i = 0; i < rxq->ifr_nfl; i++, fl++) {
		fl->ifl_size = scctx->isc_nrxd[rxq->ifr_fl_offset]; /* this isn't necessarily the same */
		/* Set up DMA tag for RX buffers. */
		err = bus_dma_tag_create(bus_get_dma_tag(dev), /* parent */
			    1, 0,			/* alignment, bounds */
			    lowaddr,			/* lowaddr */
			    BUS_SPACE_MAXADDR,		/* highaddr */
			    NULL, NULL,			/* filter, filterarg */
			    sctx->isc_rx_maxsize,	/* maxsize */
			    sctx->isc_rx_nsegments,	/* nsegments */
			    sctx->isc_rx_maxsegsize,	/* maxsegsize */
			    0,				/* flags */
			    NULL,			/* lockfunc */
			    NULL,			/* lockarg */
			    &fl->ifl_buf_tag);
		if (err) {
			device_printf(dev,
			    "Unable to allocate RX DMA tag: %d\n", err);
			goto fail;
		}

		/* Allocate memory for the RX mbuf map. */
		if (!(fl->ifl_sds.ifsd_m =
		    (struct mbuf **) malloc(sizeof(struct mbuf *) *
			    scctx->isc_nrxd[rxq->ifr_fl_offset], M_IFLIB, M_NOWAIT | M_ZERO))) {
			device_printf(dev,
			    "Unable to allocate RX mbuf map memory\n");
			err = ENOMEM;
			goto fail;
		}

		/* Allocate memory for the direct RX cluster pointer map. */
		if (!(fl->ifl_sds.ifsd_cl =
		    (caddr_t *) malloc(sizeof(caddr_t) *
			    scctx->isc_nrxd[rxq->ifr_fl_offset], M_IFLIB, M_NOWAIT | M_ZERO))) {
			device_printf(dev,
			    "Unable to allocate RX cluster map memory\n");
			err = ENOMEM;
			goto fail;
		}

		/* Allocate memory for the RX cluster bus address map. */
		if (!(fl->ifl_sds.ifsd_ba =
		    (bus_addr_t *) malloc(sizeof(bus_addr_t) *
			    scctx->isc_nrxd[rxq->ifr_fl_offset], M_IFLIB, M_NOWAIT | M_ZERO))) {
			device_printf(dev,
			    "Unable to allocate RX bus address map memory\n");
			err = ENOMEM;
			goto fail;
		}

		/*
		 * Create the DMA maps for RX buffers.
		 */
		if (!(fl->ifl_sds.ifsd_map =
		    (bus_dmamap_t *) malloc(sizeof(bus_dmamap_t) * scctx->isc_nrxd[rxq->ifr_fl_offset], M_IFLIB, M_NOWAIT | M_ZERO))) {
			device_printf(dev,
			    "Unable to allocate RX buffer DMA map memory\n");
			err = ENOMEM;
			goto fail;
		}
		for (int i = 0; i < scctx->isc_nrxd[rxq->ifr_fl_offset]; i++) {
			err = bus_dmamap_create(fl->ifl_buf_tag, 0,
			    &fl->ifl_sds.ifsd_map[i]);
			if (err != 0) {
				device_printf(dev, "Unable to create RX buffer DMA map\n");
				goto fail;
			}
		}
	}
	return (0);

fail:
	iflib_rx_structures_free(ctx);
	return (err);
}

/*
 * Internal service routines
 */

struct rxq_refill_cb_arg {
	int               error;
	bus_dma_segment_t seg;
	int               nseg;
};

static void
_rxq_refill_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
{
	struct rxq_refill_cb_arg *cb_arg = arg;

	cb_arg->error = error;
	cb_arg->seg = segs[0];
	cb_arg->nseg = nseg;
}

/**
 * iflib_fl_refill - refill an rxq free-buffer list
 * @ctx: the iflib context
 * @fl: the free list to refill
 * @count: the number of new buffers to allocate
 *
 * (Re)populate an rxq free-buffer list with up to @count new packet buffers.
 * The caller must assure that @count does not exceed the queue's capacity
 * minus one (since we always leave a descriptor unavailable).
 */
static uint8_t
iflib_fl_refill(if_ctx_t ctx, iflib_fl_t fl, int count)
{
	struct if_rxd_update iru;
	struct rxq_refill_cb_arg cb_arg;
	struct mbuf *m;
	caddr_t cl, *sd_cl;
	struct mbuf **sd_m;
	bus_dmamap_t *sd_map;
	bus_addr_t bus_addr, *sd_ba;
	int err, frag_idx, i, idx, n, pidx;
	qidx_t credits;

	MPASS(count <= fl->ifl_size - fl->ifl_credits - 1);

	sd_m = fl->ifl_sds.ifsd_m;
	sd_map = fl->ifl_sds.ifsd_map;
	sd_cl = fl->ifl_sds.ifsd_cl;
	sd_ba = fl->ifl_sds.ifsd_ba;
	pidx = fl->ifl_pidx;
	idx = pidx;
	frag_idx = fl->ifl_fragidx;
	credits = fl->ifl_credits;

	i = 0;
	n = count;
	MPASS(n > 0);
	MPASS(credits + n <= fl->ifl_size);

	if (pidx < fl->ifl_cidx)
		MPASS(pidx + n <= fl->ifl_cidx);
	if (pidx == fl->ifl_cidx && (credits < fl->ifl_size))
		MPASS(fl->ifl_gen == 0);
	if (pidx > fl->ifl_cidx)
		MPASS(n <= fl->ifl_size - pidx + fl->ifl_cidx);

	DBG_COUNTER_INC(fl_refills);
	if (n > 8)
		DBG_COUNTER_INC(fl_refills_large);
	iru_init(&iru, fl->ifl_rxq, fl->ifl_id);
	while (n-- > 0) {
		/*
		 * We allocate an uninitialized mbuf + cluster, mbuf is
		 * initialized after rx.
		 *
		 * If the cluster is still set then we know a minimum sized
		 * packet was received
		 */
		bit_ffc_at(fl->ifl_rx_bitmap, frag_idx, fl->ifl_size,
		    &frag_idx);
		if (frag_idx < 0)
			bit_ffc(fl->ifl_rx_bitmap, fl->ifl_size, &frag_idx);
		MPASS(frag_idx >= 0);
		if ((cl = sd_cl[frag_idx]) == NULL) {
			cl = uma_zalloc(fl->ifl_zone, M_NOWAIT);
			if (__predict_false(cl == NULL))
				break;

			cb_arg.error = 0;
			MPASS(sd_map != NULL);
			err = bus_dmamap_load(fl->ifl_buf_tag, sd_map[frag_idx],
			    cl, fl->ifl_buf_size, _rxq_refill_cb, &cb_arg,
			    BUS_DMA_NOWAIT);
			if (__predict_false(err != 0 || cb_arg.error)) {
				uma_zfree(fl->ifl_zone, cl);
				break;
			}

			sd_ba[frag_idx] = bus_addr = cb_arg.seg.ds_addr;
			sd_cl[frag_idx] = cl;
#if MEMORY_LOGGING
			fl->ifl_cl_enqueued++;
#endif
		} else {
			bus_addr = sd_ba[frag_idx];
		}
		bus_dmamap_sync(fl->ifl_buf_tag, sd_map[frag_idx],
		    BUS_DMASYNC_PREREAD);

		if (sd_m[frag_idx] == NULL) {
			m = m_gethdr_raw(M_NOWAIT, 0);
			if (__predict_false(m == NULL))
				break;
			sd_m[frag_idx] = m;
		}
		bit_set(fl->ifl_rx_bitmap, frag_idx);
#if MEMORY_LOGGING
		fl->ifl_m_enqueued++;
#endif

		DBG_COUNTER_INC(rx_allocs);
		fl->ifl_rxd_idxs[i] = frag_idx;
		fl->ifl_bus_addrs[i] = bus_addr;
		credits++;
		i++;
		MPASS(credits <= fl->ifl_size);
		if (++idx == fl->ifl_size) {
#ifdef INVARIANTS
			fl->ifl_gen = 1;
#endif
			idx = 0;
		}
		if (n == 0 || i == IFLIB_MAX_RX_REFRESH) {
			iru.iru_pidx = pidx;
			iru.iru_count = i;
			ctx->isc_rxd_refill(ctx->ifc_softc, &iru);
			fl->ifl_pidx = idx;
			fl->ifl_credits = credits;
			pidx = idx;
			i = 0;
		}
	}

	if (n < count - 1) {
		if (i != 0) {
			iru.iru_pidx = pidx;
			iru.iru_count = i;
			ctx->isc_rxd_refill(ctx->ifc_softc, &iru);
			fl->ifl_pidx = idx;
			fl->ifl_credits = credits;
		}
		DBG_COUNTER_INC(rxd_flush);
		bus_dmamap_sync(fl->ifl_ifdi->idi_tag, fl->ifl_ifdi->idi_map,
		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
		ctx->isc_rxd_flush(ctx->ifc_softc, fl->ifl_rxq->ifr_id,
		    fl->ifl_id, fl->ifl_pidx);
		if (__predict_true(bit_test(fl->ifl_rx_bitmap, frag_idx))) {
			fl->ifl_fragidx = frag_idx + 1;
			if (fl->ifl_fragidx == fl->ifl_size)
				fl->ifl_fragidx = 0;
		} else {
			fl->ifl_fragidx = frag_idx;
		}
	}

	return (n == -1 ? 0 : IFLIB_RXEOF_EMPTY);
}

static inline uint8_t
iflib_fl_refill_all(if_ctx_t ctx, iflib_fl_t fl)
{
	/*
	 * We leave an unused descriptor to avoid pidx to catch up with cidx.
	 * This is important as it confuses most NICs. For instance,
	 * Intel NICs have (per receive ring) RDH and RDT registers, where
	 * RDH points to the next receive descriptor to be used by the NIC,
	 * and RDT for the next receive descriptor to be published by the
	 * driver to the NIC (RDT - 1 is thus the last valid one).
	 * The condition RDH == RDT means no descriptors are available to
	 * the NIC, and thus it would be ambiguous if it also meant that
	 * all the descriptors are available to the NIC.
	 */
	int32_t reclaimable = fl->ifl_size - fl->ifl_credits - 1;
#ifdef INVARIANTS
	int32_t delta = fl->ifl_size - get_inuse(fl->ifl_size, fl->ifl_cidx, fl->ifl_pidx, fl->ifl_gen) - 1;
#endif

	MPASS(fl->ifl_credits <= fl->ifl_size);
	MPASS(reclaimable == delta);

	if (reclaimable > 0)
		return (iflib_fl_refill(ctx, fl, reclaimable));
	return (0);
}

uint8_t
iflib_in_detach(if_ctx_t ctx)
{
	bool in_detach;

	STATE_LOCK(ctx);
	in_detach = !!(ctx->ifc_flags & IFC_IN_DETACH);
	STATE_UNLOCK(ctx);
	return (in_detach);
}

static void
iflib_fl_bufs_free(iflib_fl_t fl)
{
	iflib_dma_info_t idi = fl->ifl_ifdi;
	bus_dmamap_t sd_map;
	uint32_t i;

	for (i = 0; i < fl->ifl_size; i++) {
		struct mbuf **sd_m = &fl->ifl_sds.ifsd_m[i];
		caddr_t *sd_cl = &fl->ifl_sds.ifsd_cl[i];

		if (*sd_cl != NULL) {
			sd_map = fl->ifl_sds.ifsd_map[i];
			bus_dmamap_sync(fl->ifl_buf_tag, sd_map,
			    BUS_DMASYNC_POSTREAD);
			bus_dmamap_unload(fl->ifl_buf_tag, sd_map);
			uma_zfree(fl->ifl_zone, *sd_cl);
			*sd_cl = NULL;
			if (*sd_m != NULL) {
				m_init(*sd_m, M_NOWAIT, MT_DATA, 0);
				m_free_raw(*sd_m);
				*sd_m = NULL;
			}
		} else {
			MPASS(*sd_m == NULL);
		}
#if MEMORY_LOGGING
		fl->ifl_m_dequeued++;
		fl->ifl_cl_dequeued++;
#endif
	}
#ifdef INVARIANTS
	for (i = 0; i < fl->ifl_size; i++) {
		MPASS(fl->ifl_sds.ifsd_cl[i] == NULL);
		MPASS(fl->ifl_sds.ifsd_m[i] == NULL);
	}
#endif
	/*
	 * Reset free list values
	 */
	fl->ifl_credits = fl->ifl_cidx = fl->ifl_pidx = fl->ifl_gen = fl->ifl_fragidx = 0;
	bzero(idi->idi_vaddr, idi->idi_size);
}

/*********************************************************************
 *
 *  Initialize a free list and its buffers.
 *
 **********************************************************************/
static int
iflib_fl_setup(iflib_fl_t fl)
{
	iflib_rxq_t rxq = fl->ifl_rxq;
	if_ctx_t ctx = rxq->ifr_ctx;
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	int qidx;

	bit_nclear(fl->ifl_rx_bitmap, 0, fl->ifl_size - 1);
	/*
	 * Free current RX buffer structs and their mbufs
	 */
	iflib_fl_bufs_free(fl);
	/* Now replenish the mbufs */
	MPASS(fl->ifl_credits == 0);
	qidx = rxq->ifr_fl_offset + fl->ifl_id;
	if (scctx->isc_rxd_buf_size[qidx] != 0)
		fl->ifl_buf_size = scctx->isc_rxd_buf_size[qidx];
	else
		fl->ifl_buf_size = ctx->ifc_rx_mbuf_sz;
	/*
	 * ifl_buf_size may be a driver-supplied value, so pull it up
	 * to the selected mbuf size.
	 */
	fl->ifl_buf_size = iflib_get_mbuf_size_for(fl->ifl_buf_size);
	if (fl->ifl_buf_size > ctx->ifc_max_fl_buf_size)
		ctx->ifc_max_fl_buf_size = fl->ifl_buf_size;
	fl->ifl_cltype = m_gettype(fl->ifl_buf_size);
	fl->ifl_zone = m_getzone(fl->ifl_buf_size);

	/*
	 * Avoid pre-allocating zillions of clusters to an idle card
	 * potentially speeding up attach. In any case make sure
	 * to leave a descriptor unavailable. See the comment in
	 * iflib_fl_refill_all().
	 */
	MPASS(fl->ifl_size > 0);
	(void)iflib_fl_refill(ctx, fl, min(128, fl->ifl_size - 1));
	if (min(128, fl->ifl_size - 1) != fl->ifl_credits)
		return (ENOBUFS);
	/*
	 * handle failure
	 */
	MPASS(rxq != NULL);
	MPASS(fl->ifl_ifdi != NULL);
	bus_dmamap_sync(fl->ifl_ifdi->idi_tag, fl->ifl_ifdi->idi_map,
	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
	return (0);
}

/*********************************************************************
 *
 *  Free receive ring data structures
 *
 **********************************************************************/
static void
iflib_rx_sds_free(iflib_rxq_t rxq)
{
	iflib_fl_t fl;
	int i, j;

	if (rxq->ifr_fl != NULL) {
		for (i = 0; i < rxq->ifr_nfl; i++) {
			fl = &rxq->ifr_fl[i];
			if (fl->ifl_buf_tag != NULL) {
				if (fl->ifl_sds.ifsd_map != NULL) {
					for (j = 0; j < fl->ifl_size; j++) {
						bus_dmamap_sync(
						    fl->ifl_buf_tag,
						    fl->ifl_sds.ifsd_map[j],
						    BUS_DMASYNC_POSTREAD);
						bus_dmamap_unload(
						    fl->ifl_buf_tag,
						    fl->ifl_sds.ifsd_map[j]);
						bus_dmamap_destroy(
						    fl->ifl_buf_tag,
						    fl->ifl_sds.ifsd_map[j]);
					}
				}
				bus_dma_tag_destroy(fl->ifl_buf_tag);
				fl->ifl_buf_tag = NULL;
			}
			free(fl->ifl_sds.ifsd_m, M_IFLIB);
			free(fl->ifl_sds.ifsd_cl, M_IFLIB);
			free(fl->ifl_sds.ifsd_ba, M_IFLIB);
			free(fl->ifl_sds.ifsd_map, M_IFLIB);
			free(fl->ifl_rx_bitmap, M_IFLIB);
			fl->ifl_sds.ifsd_m = NULL;
			fl->ifl_sds.ifsd_cl = NULL;
			fl->ifl_sds.ifsd_ba = NULL;
			fl->ifl_sds.ifsd_map = NULL;
			fl->ifl_rx_bitmap = NULL;
		}
		free(rxq->ifr_fl, M_IFLIB);
		rxq->ifr_fl = NULL;
		free(rxq->ifr_ifdi, M_IFLIB);
		rxq->ifr_ifdi = NULL;
		rxq->ifr_cq_cidx = 0;
	}
}

/*
 * Timer routine
 */
static void
iflib_timer(void *arg)
{
	iflib_txq_t txq = arg;
	if_ctx_t ctx = txq->ift_ctx;
	if_softc_ctx_t sctx = &ctx->ifc_softc_ctx;
	uint64_t this_tick = ticks;

	if (!(if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING))
		return;

	/*
	 * Check on the state of the TX queue(s); this can be done
	 * without the lock: the counters the check reads are only
	 * advanced by the queue's tx task and a stale read just
	 * delays the verdict by one timer period.
	 */
	if (this_tick - txq->ift_last_timer_tick >= iflib_timer_default) {
		qidx_t in_use, outstanding;
		bool demand, frozen;

		txq->ift_last_timer_tick = this_tick;
		IFDI_TIMER(ctx, txq->ift_id);

		/*
		 * Descriptors the hardware has not reported as
		 * completed: neither harvested as credits
		 * (ift_processed) nor reclaimed (ift_cleaned accounts
		 * the difference to ift_in_use).  The tail whose
		 * report-status request is still deferred is never
		 * reported and must not count.
		 */
		in_use = txq->ift_in_use;
		outstanding = in_use -
		    (qidx_t)(txq->ift_processed - txq->ift_cleaned);

		/*
		 * The queue is frozen while it has descriptors the
		 * hardware has not reported as completed and none
		 * were reclaimed over the period; the link must be
		 * up, with no pause frames and no pending doorbell
		 * (the laggard check below rings it).
		 *
		 * Being frozen is not a fault - the hardware may defer
		 * marking descriptors as completed indefinitely, and
		 * 8254x hardware does so for a quiet queue.  Continue
		 * arming only while demand persists: the outstanding
		 * count grows, the software ring is stalled, or the
		 * hardware ring has reached iflib's backpressure
		 * threshold.  The last condition covers simple-TX, which
		 * does not use the software ring.  This also prevents one
		 * mixed lockless counter sample from arming a quiet queue
		 * until the verdict.  Act only once it has stayed frozen
		 * under demand for
		 * net.iflib.tx_watchdog_periods consecutive periods.
		 */
		frozen = outstanding > txq->ift_rs_pending &&
		    txq->ift_processed == txq->ift_processed_prev &&
		    txq->ift_db_pending == 0 &&
		    sctx->isc_pause_frames == 0 &&
		    ctx->ifc_link_state == LINK_STATE_UP;
		demand = outstanding > txq->ift_outstanding_prev ||
		    ifmp_ring_is_stalled(txq->ift_br) ||
		    in_use + MAX_TX_DESC(ctx) >= txq->ift_size - txq->ift_pad;
		if (!frozen || !demand)
			txq->ift_wdog_armed = 0;
		else {
			if (txq->ift_wdog_armed < UINT16_MAX)
				txq->ift_wdog_armed++;
		}

		/*
		 * Frozen long enough: ask the hardware.  Completions
		 * ready but unharvested for this long mean the
		 * completion interrupt went missing - kick the
		 * queue's task.  Nothing ready while demand persisted
		 * means it is hung.
		 */
		if (iflib_tx_watchdog_periods > 0 &&
		    txq->ift_wdog_armed >= iflib_tx_watchdog_periods) {
			bus_dmamap_sync(txq->ift_ifdi->idi_tag,
			    txq->ift_ifdi->idi_map, BUS_DMASYNC_POSTREAD);
			if (ctx->isc_txd_credits_update(ctx->ifc_softc,
			    txq->ift_id, false) == 0) {
				device_printf(ctx->ifc_dev,
				    "Watchdog timeout (TX: %d desc "
				    "avail: %d pidx: %d) -- resetting\n",
				    txq->ift_id, TXQ_AVAIL(txq),
				    txq->ift_pidx);
				STATE_LOCK(ctx);
				if_setdrvflagbits(ctx->ifc_ifp,
				    IFF_DRV_OACTIVE, IFF_DRV_RUNNING);
				ctx->ifc_flags |=
				    (IFC_DO_WATCHDOG | IFC_DO_RESET);
				iflib_admin_intr_deferred(ctx);
				STATE_UNLOCK(ctx);
				return;
			}
			GROUPTASK_ENQUEUE(&txq->ift_task);
		}
		txq->ift_outstanding_prev = outstanding;
		txq->ift_processed_prev = txq->ift_processed;
	}
	/* Handle any laggards */
	if (txq->ift_db_pending ||
	    (txq->ift_drbr != NULL &&
	    (!if_altq_is_enabled(ctx->ifc_ifp) || txq->ift_id == 0) &&
	    !drbr_empty(ctx->ifc_ifp, txq->ift_drbr)))
		GROUPTASK_ENQUEUE(&txq->ift_task);

	sctx->isc_pause_frames = 0;
	if (if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING)
		callout_reset_on(&txq->ift_timer, iflib_timer_default, iflib_timer,
		    txq, txq->ift_timer.c_cpu);
}

static uint16_t
iflib_get_mbuf_size_for(unsigned int size)
{

	if (size <= MCLBYTES)
		return (MCLBYTES);
	else
		return (MJUMPAGESIZE);
}

static void
iflib_calc_rx_mbuf_sz(if_ctx_t ctx)
{
	if_softc_ctx_t sctx = &ctx->ifc_softc_ctx;

	/*
	 * XXX don't set the max_frame_size to larger
	 * than the hardware can handle
	 */
	ctx->ifc_rx_mbuf_sz =
	    iflib_get_mbuf_size_for(sctx->isc_max_frame_size);
}

uint32_t
iflib_get_rx_mbuf_sz(if_ctx_t ctx)
{

	return (ctx->ifc_rx_mbuf_sz);
}

static void
iflib_init_locked(if_ctx_t ctx)
{
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	if_t ifp = ctx->ifc_ifp;
	iflib_fl_t fl;
	iflib_txq_t txq;
	iflib_rxq_t rxq;
	int i, j, tx_ip_csum_flags, tx_ip6_csum_flags;
	bool init_failed;

	sx_assert(&ctx->ifc_ctx_sx, SA_XLOCKED);
	/* Configuration changes made during suspend take effect on resume. */
	if (ctx->ifc_pm_state != IFLIB_PM_ACTIVE)
		return;
	KASSERT(ctx->ifc_datapath_state == IFLIB_DP_STOPPED,
	    ("iflib init from datapath state %d", ctx->ifc_datapath_state));
	ctx->ifc_datapath_state = IFLIB_DP_STARTING;

	if_setdrvflagbits(ifp, IFF_DRV_OACTIVE, IFF_DRV_RUNNING);
	IFDI_INTR_DISABLE(ctx);

	/*
	 * See iflib_stop(). Useful in case iflib_init_locked() is
	 * called without first calling iflib_stop().
	 */
	netmap_disable_all_rings(ifp);

	tx_ip_csum_flags = scctx->isc_tx_csum_flags & (CSUM_IP | CSUM_TCP | CSUM_UDP | CSUM_SCTP);
	tx_ip6_csum_flags = scctx->isc_tx_csum_flags & (CSUM_IP6_TCP | CSUM_IP6_UDP | CSUM_IP6_SCTP);
	/* Set hardware offload abilities */
	if_clearhwassist(ifp);
	if (if_getcapenable(ifp) & IFCAP_TXCSUM)
		if_sethwassistbits(ifp, tx_ip_csum_flags, 0);
	if (if_getcapenable(ifp) & IFCAP_TXCSUM_IPV6)
		if_sethwassistbits(ifp,  tx_ip6_csum_flags, 0);
	if (if_getcapenable(ifp) & IFCAP_TSO4)
		if_sethwassistbits(ifp, CSUM_IP_TSO, 0);
	if (if_getcapenable(ifp) & IFCAP_TSO6)
		if_sethwassistbits(ifp, CSUM_IP6_TSO, 0);

	for (i = 0, txq = ctx->ifc_txqs; i < scctx->isc_ntxqsets; i++, txq++) {
		CALLOUT_LOCK(txq);
		callout_stop(&txq->ift_timer);
#ifdef DEV_NETMAP
		callout_stop(&txq->ift_netmap_timer);
#endif /* DEV_NETMAP */
		CALLOUT_UNLOCK(txq);
		(void)iflib_netmap_txq_init(ctx, txq);
	}
	/*
	 * Calculate a suitable Rx mbuf size prior to calling IFDI_INIT, so
	 * that drivers can use the value when setting up the hardware receive
	 * buffers.
	 */
	iflib_calc_rx_mbuf_sz(ctx);

#ifdef INVARIANTS
	i = if_getdrvflags(ifp);
#endif
	STATE_LOCK(ctx);
	ctx->ifc_flags &= ~IFC_INIT_FAILED;
	STATE_UNLOCK(ctx);
	IFDI_INIT(ctx);
	MPASS(if_getdrvflags(ifp) == i);
	STATE_LOCK(ctx);
	init_failed = (ctx->ifc_flags & IFC_INIT_FAILED) != 0;
	STATE_UNLOCK(ctx);
	if (init_failed) {
		/*
		 * IFDI_INIT failed, but that alone does not prove that the
		 * driver stopped every queue or fenced DMA.  Force the next
		 * lifecycle transition through the driver's stop method.
		 */
		ctx->ifc_datapath_state = IFLIB_DP_FAILED;
		return;
	}
	for (i = 0, rxq = ctx->ifc_rxqs; i < scctx->isc_nrxqsets; i++, rxq++) {
		if (iflib_netmap_rxq_init(ctx, rxq) > 0) {
			/* This rxq is in netmap mode. Skip normal init. */
			continue;
		}
		for (j = 0, fl = rxq->ifr_fl; j < rxq->ifr_nfl; j++, fl++) {
			if (iflib_fl_setup(fl)) {
				device_printf(ctx->ifc_dev,
				    "setting up free list %d failed - "
				    "check cluster settings\n", j);
				/*
				 * IFDI_INIT has started the hardware.  Stop it before
				 * releasing partially populated receive mappings.
				 */
				iflib_init_failed(ctx);
				iflib_stop(ctx);
				return;
			}
		}
	}
	if_setdrvflagbits(ctx->ifc_ifp, IFF_DRV_RUNNING, IFF_DRV_OACTIVE);
	IFDI_INTR_ENABLE(ctx);
	txq = ctx->ifc_txqs;
	for (i = 0; i < scctx->isc_ntxqsets; i++, txq++) {
		callout_reset_on(&txq->ift_timer, iflib_timer_default, iflib_timer, txq,
			txq->ift_timer.c_cpu);
		if (ctx->ifc_sysctl_simple_tx) {
			atomic_clear_rel_int(&txq->ift_producers,
			    IFLIB_TXQ_QUIESCING);
		}
	}

	/* Re-enable txsync/rxsync. */
	netmap_enable_all_rings(ifp);
	ctx->ifc_datapath_state = IFLIB_DP_RUNNING;
}

static int
iflib_media_change(if_t ifp)
{
	if_ctx_t ctx = if_getsoftc(ifp);
	bool restart;
	int err;

	CTX_LOCK(ctx);
	if (ctx->ifc_pm_state != IFLIB_PM_ACTIVE) {
		CTX_UNLOCK(ctx);
		return (EBUSY);
	}
	restart = (if_getflags(ifp) & IFF_UP) != 0 ||
	    ctx->ifc_datapath_state == IFLIB_DP_RUNNING;
	if ((err = IFDI_MEDIA_CHANGE(ctx)) == 0 && restart)
		iflib_if_init_locked(ctx);
	CTX_UNLOCK(ctx);
	return (err);
}

static void
iflib_media_status(if_t ifp, struct ifmediareq *ifmr)
{
	if_ctx_t ctx = if_getsoftc(ifp);
	bool oactive, running;

	STATE_LOCK(ctx);
	running = (if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING);
	oactive = (if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_OACTIVE);
	STATE_UNLOCK(ctx);

	CTX_LOCK(ctx);
	if (ctx->ifc_pm_state != IFLIB_PM_ACTIVE) {
		ifmr->ifm_status = IFM_AVALID;
		ifmr->ifm_active = IFM_ETHER | IFM_NONE;
		CTX_UNLOCK(ctx);
		return;
	}
	/*
	 * There is no need to update the admin status when it is done regularly by
	 * _task_fn_admin(), so only do it if that's not running. That can be quite
	 * expensive on some drivers.
	 */
	if ((!running && !oactive) &&
	    !(ctx->ifc_sctx->isc_flags & IFLIB_ADMIN_ALWAYS_RUN)) {
		IFDI_UPDATE_ADMIN_STATUS(ctx);
	}
	IFDI_MEDIA_STATUS(ctx, ifmr);
	CTX_UNLOCK(ctx);
}

static void
iflib_stop(if_ctx_t ctx)
{
	iflib_txq_t txq = ctx->ifc_txqs;
	iflib_rxq_t rxq = ctx->ifc_rxqs;
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	iflib_dma_info_t di;
	iflib_fl_t fl;
	bool stop_hardware;
	int i, j;

	sx_assert(&ctx->ifc_ctx_sx, SA_XLOCKED);
	KASSERT(ctx->ifc_datapath_state != IFLIB_DP_STOPPING,
	    ("recursive iflib stop"));
	stop_hardware = ctx->ifc_datapath_state != IFLIB_DP_STOPPED;

	if (ctx->ifc_sysctl_simple_tx && stop_hardware) {
		/* close deferral rings to new traffic */
		for (i = 0; i < scctx->isc_ntxqsets; i++) {
			atomic_set_int(&txq[i].ift_producers,
			    IFLIB_TXQ_QUIESCING);
		}
	}

	/* Tell the stack that the interface is no longer active */
	if_setdrvflagbits(ctx->ifc_ifp, IFF_DRV_OACTIVE, IFF_DRV_RUNNING);

	if (stop_hardware) {
		ctx->ifc_datapath_state = IFLIB_DP_STOPPING;
		IFDI_INTR_DISABLE(ctx);
		DELAY(1000);
		IFDI_STOP(ctx);
		DELAY(1000);
		ctx->ifc_datapath_state = IFLIB_DP_STOPPED;
	}

	/*
	 * Stop any pending txsync/rxsync and prevent new ones
	 * form starting. Processes blocked in poll() will get
	 * POLLERR.
	 */
	netmap_disable_all_rings(ctx->ifc_ifp);

	iflib_debug_reset();
	/* Wait for current tx queue users to exit to disarm watchdog timer. */
	for (i = 0; i < scctx->isc_ntxqsets; i++, txq++) {
		/* make sure all transmitters have completed before proceeding XXX */

		CALLOUT_LOCK(txq);
		callout_stop(&txq->ift_timer);
#ifdef DEV_NETMAP
		callout_stop(&txq->ift_netmap_timer);
#endif /* DEV_NETMAP */
		CALLOUT_UNLOCK(txq);

		/* clean any enqueued buffers */
		if (!ctx->ifc_sysctl_simple_tx) {
			iflib_ifmp_purge(txq);
		} else {
			mtx_lock(&txq->ift_mtx);
			drbr_flush(ctx->ifc_ifp, txq->ift_drbr);
			mtx_unlock(&txq->ift_mtx);
		}
		/* Free any existing tx buffers. */
		for (j = 0; j < txq->ift_size; j++) {
			iflib_txsd_free(ctx, txq, j);
		}
		txq->ift_processed = txq->ift_cleaned = txq->ift_cidx_processed = 0;
		txq->ift_processed_prev = 0;
		txq->ift_outstanding_prev = 0;
		txq->ift_wdog_armed = 0;
		txq->ift_in_use = txq->ift_gen = txq->ift_no_desc_avail = 0;
		txq->ift_npending = txq->ift_db_pending = 0;
		txq->ift_rs_pending = 0;
		if (sctx->isc_flags & IFLIB_PRESERVE_TX_INDICES)
			txq->ift_cidx = txq->ift_pidx;
		else
			txq->ift_cidx = txq->ift_pidx = 0;

		txq->ift_closed = txq->ift_mbuf_defrag = txq->ift_mbuf_defrag_failed = 0;
		txq->ift_no_tx_dma_setup = txq->ift_txd_encap_efbig = txq->ift_map_failed = 0;
		txq->ift_pullups = 0;
		txq->ift_drbr_direct = txq->ift_drbr_stall = 0;
		if (ctx->ifc_sysctl_simple_tx) {
			counter_u64_zero(txq->ift_drbr_deferred);
			counter_u64_zero(txq->ift_drbr_drops);
			counter_u64_zero(txq->ift_drbr_blocked);
			counter_u64_zero(txq->ift_drbr_remote);
		}
		ifmp_ring_reset_stats(txq->ift_br);
		for (j = 0, di = txq->ift_ifdi; j < sctx->isc_ntxqs; j++, di++)
			bzero((void *)di->idi_vaddr, di->idi_size);
	}
	for (i = 0; i < scctx->isc_nrxqsets; i++, rxq++) {
		if (rxq->ifr_task.gt_taskqueue != NULL)
			gtaskqueue_drain(rxq->ifr_task.gt_taskqueue,
				 &rxq->ifr_task.gt_task);

		rxq->ifr_cq_cidx = 0;
		for (j = 0, di = rxq->ifr_ifdi; j < sctx->isc_nrxqs; j++, di++)
			bzero((void *)di->idi_vaddr, di->idi_size);
		/* also resets the free lists pidx/cidx */
		for (j = 0, fl = rxq->ifr_fl; j < rxq->ifr_nfl; j++, fl++)
			iflib_fl_bufs_free(fl);
	}
}

static inline caddr_t
calc_next_rxd(iflib_fl_t fl, int cidx)
{
	qidx_t size;
	int nrxd;
	caddr_t start, end, cur, next;

	nrxd = fl->ifl_size;
	size = fl->ifl_rxd_size;
	start = fl->ifl_ifdi->idi_vaddr;

	if (__predict_false(size == 0))
		return (start);
	cur = start + size * cidx;
	end = start + size * nrxd;
	next = CACHE_PTR_NEXT(cur);
	return (next < end ? next : start);
}

static inline void
prefetch_pkts(iflib_fl_t fl, int cidx)
{
	int nextptr;
	int nrxd = fl->ifl_size;
	caddr_t next_rxd;

	nextptr = (cidx + CACHE_PTR_INCREMENT) & (nrxd - 1);
	prefetch(&fl->ifl_sds.ifsd_m[nextptr]);
	prefetch(&fl->ifl_sds.ifsd_cl[nextptr]);
	next_rxd = calc_next_rxd(fl, cidx);
	prefetch(next_rxd);
	prefetch(fl->ifl_sds.ifsd_m[(cidx + 1) & (nrxd - 1)]);
	prefetch(fl->ifl_sds.ifsd_m[(cidx + 2) & (nrxd - 1)]);
	prefetch(fl->ifl_sds.ifsd_m[(cidx + 3) & (nrxd - 1)]);
	prefetch(fl->ifl_sds.ifsd_m[(cidx + 4) & (nrxd - 1)]);
	prefetch(fl->ifl_sds.ifsd_cl[(cidx + 1) & (nrxd - 1)]);
	prefetch(fl->ifl_sds.ifsd_cl[(cidx + 2) & (nrxd - 1)]);
	prefetch(fl->ifl_sds.ifsd_cl[(cidx + 3) & (nrxd - 1)]);
	prefetch(fl->ifl_sds.ifsd_cl[(cidx + 4) & (nrxd - 1)]);
}

static struct mbuf *
rxd_frag_to_sd(iflib_rxq_t rxq, if_rxd_frag_t irf, bool unload, if_rxsd_t sd,
    int *pf_rv, if_rxd_info_t ri)
{
	bus_dmamap_t map;
	iflib_fl_t fl;
	caddr_t payload;
	struct mbuf *m;
	int flid, cidx, len, next;

	map = NULL;
	flid = irf->irf_flid;
	cidx = irf->irf_idx;
	fl = &rxq->ifr_fl[flid];
	sd->ifsd_fl = fl;
	sd->ifsd_cl = &fl->ifl_sds.ifsd_cl[cidx];
	fl->ifl_credits--;
#if MEMORY_LOGGING
	fl->ifl_m_dequeued++;
#endif
	if (rxq->ifr_ctx->ifc_flags & IFC_PREFETCH)
		prefetch_pkts(fl, cidx);
	next = (cidx + CACHE_PTR_INCREMENT) & (fl->ifl_size - 1);
	prefetch(&fl->ifl_sds.ifsd_map[next]);
	map = fl->ifl_sds.ifsd_map[cidx];

	bus_dmamap_sync(fl->ifl_buf_tag, map, BUS_DMASYNC_POSTREAD);

	if (rxq->pfil != NULL && PFIL_HOOKED_IN(rxq->pfil) && pf_rv != NULL &&
	    irf->irf_len != 0) {
		payload  = *sd->ifsd_cl;
		payload +=  ri->iri_pad;
		len = ri->iri_len - ri->iri_pad;
		*pf_rv = pfil_mem_in(rxq->pfil, payload, len, ri->iri_ifp, &m);
		switch (*pf_rv) {
		case PFIL_DROPPED:
		case PFIL_CONSUMED:
			/*
			 * The filter ate it.  Everything is recycled.
			 */
			m = NULL;
			unload = 0;
			break;
		case PFIL_REALLOCED:
			/*
			 * The filter copied it.  Everything is recycled.
			 * 'm' points at new mbuf.
			 */
			unload = 0;
			break;
		case PFIL_PASS:
			/*
			 * Filter said it was OK, so receive like
			 * normal
			 */
			m = fl->ifl_sds.ifsd_m[cidx];
			fl->ifl_sds.ifsd_m[cidx] = NULL;
			break;
		default:
			MPASS(0);
		}
	} else {
		m = fl->ifl_sds.ifsd_m[cidx];
		fl->ifl_sds.ifsd_m[cidx] = NULL;
		if (pf_rv != NULL)
			*pf_rv = PFIL_PASS;
	}

	if (unload && irf->irf_len != 0)
		bus_dmamap_unload(fl->ifl_buf_tag, map);
	fl->ifl_cidx = (fl->ifl_cidx + 1) & (fl->ifl_size - 1);
	if (__predict_false(fl->ifl_cidx == 0))
		fl->ifl_gen = 0;
	bit_clear(fl->ifl_rx_bitmap, cidx);
	return (m);
}

static struct mbuf *
assemble_segments(iflib_rxq_t rxq, if_rxd_info_t ri, if_rxsd_t sd, int *pf_rv)
{
	struct mbuf *m, *mh, *mt;
	caddr_t cl;
	int  *pf_rv_ptr, flags, i, padlen;
	bool consumed;

	i = 0;
	mh = NULL;
	consumed = false;
	*pf_rv = PFIL_PASS;
	pf_rv_ptr = pf_rv;
	do {
		m = rxd_frag_to_sd(rxq, &ri->iri_frags[i], !consumed, sd,
		    pf_rv_ptr, ri);

		MPASS(*sd->ifsd_cl != NULL);

		/*
		 * Exclude zero-length frags & frags from
		 * packets the filter has consumed or dropped
		 */
		if (ri->iri_frags[i].irf_len == 0 || consumed ||
		    *pf_rv == PFIL_CONSUMED || *pf_rv == PFIL_DROPPED) {
			if (mh == NULL) {
				consumed = true;
				pf_rv_ptr = NULL;
			}
			/* XXX we can save the cluster here, but not the mbuf */
			if (m != NULL) {
				m_init(m, M_NOWAIT, MT_DATA, 0);
				m_free(m);
			}
			continue;
		}
		if (mh == NULL) {
			flags = M_PKTHDR | M_EXT;
			mh = mt = m;
			padlen = ri->iri_pad;
		} else {
			flags = M_EXT;
			mt->m_next = m;
			mt = m;
			/* assuming padding is only on the first fragment */
			padlen = 0;
		}
		cl = *sd->ifsd_cl;
		*sd->ifsd_cl = NULL;

		/* Can these two be made one ? */
		m_init(m, M_NOWAIT, MT_DATA, flags);
		m_cljset(m, cl, sd->ifsd_fl->ifl_cltype);
		/*
		 * These must follow m_init and m_cljset
		 */
		m->m_data += padlen;
		ri->iri_len -= padlen;
		m->m_len = ri->iri_frags[i].irf_len;
	} while (++i < ri->iri_nfrags);

	return (mh);
}

/*
 * Process one software descriptor
 */
static struct mbuf *
iflib_rxd_pkt_get(iflib_rxq_t rxq, if_rxd_info_t ri)
{
	struct if_rxsd sd;
	struct mbuf *m;
	int pf_rv;

	/* should I merge this back in now that the two paths are basically duplicated? */
	if (ri->iri_nfrags == 1 &&
	    ri->iri_frags[0].irf_len != 0 &&
	    ri->iri_frags[0].irf_len <= MIN(IFLIB_RX_COPY_THRESH, MHLEN)) {
		m = rxd_frag_to_sd(rxq, &ri->iri_frags[0], false, &sd,
		    &pf_rv, ri);
		if (pf_rv != PFIL_PASS && pf_rv != PFIL_REALLOCED)
			return (m);
		if (pf_rv == PFIL_PASS) {
			m_init(m, M_NOWAIT, MT_DATA, M_PKTHDR);
#ifndef __NO_STRICT_ALIGNMENT
			if (!IP_ALIGNED(m) && ri->iri_pad == 0)
				m->m_data += 2;
#endif
			memcpy(m->m_data, *sd.ifsd_cl, ri->iri_len);
			m->m_len = ri->iri_frags[0].irf_len;
			m->m_data += ri->iri_pad;
			ri->iri_len -= ri->iri_pad;
		}
	} else {
		m = assemble_segments(rxq, ri, &sd, &pf_rv);
		if (m == NULL)
			return (NULL);
		if (pf_rv != PFIL_PASS && pf_rv != PFIL_REALLOCED)
			return (m);
	}
	m->m_pkthdr.len = ri->iri_len;
	m->m_pkthdr.rcvif = ri->iri_ifp;
	m->m_flags |= ri->iri_flags & IFLIB_IRI_VALID_FLAGS;
	m->m_pkthdr.ether_vtag = ri->iri_vtag;
	m->m_pkthdr.flowid = ri->iri_flowid;
#ifdef NUMA
	m->m_pkthdr.numa_domain = if_getnumadomain(ri->iri_ifp);
#endif
	M_HASHTYPE_SET(m, ri->iri_rsstype);
	m->m_pkthdr.csum_flags = ri->iri_csum_flags;
	m->m_pkthdr.csum_data = ri->iri_csum_data;
	m->m_pkthdr.rcv_tstmp = ri->iri_rcv_tstmp;
	return (m);
}

static void
_task_fn_rx_watchdog(void *context)
{
	iflib_rxq_t rxq = context;

	GROUPTASK_ENQUEUE(&rxq->ifr_task);
}

static uint8_t
iflib_rxeof(iflib_rxq_t rxq, qidx_t budget)
{
	if_t ifp;
	if_ctx_t ctx = rxq->ifr_ctx;
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	int avail, i;
	qidx_t *cidxp;
	struct if_rxd_info ri;
	int err, budget_left, rx_bytes, rx_pkts;
	iflib_fl_t fl;
#if defined(INET6) || defined(INET)
	int lro_enabled;
#endif
	uint8_t retval = 0;

	/*
	 * XXX early demux data packets so that if_input processing only handles
	 * acks in interrupt context
	 */
	struct mbuf *m, *mh, *mt;

	NET_EPOCH_ASSERT();

	ifp = ctx->ifc_ifp;
	mh = mt = NULL;
	MPASS(budget > 0);
	rx_pkts	= rx_bytes = 0;
	if (sctx->isc_flags & IFLIB_HAS_RXCQ)
		cidxp = &rxq->ifr_cq_cidx;
	else
		cidxp = &rxq->ifr_fl[0].ifl_cidx;
	if ((avail = iflib_rxd_avail(ctx, rxq, *cidxp, budget)) == 0) {
		for (i = 0, fl = &rxq->ifr_fl[0]; i < sctx->isc_nfl; i++, fl++)
			retval |= iflib_fl_refill_all(ctx, fl);
		DBG_COUNTER_INC(rx_unavail);
		return (retval);
	}

#if defined(INET6) || defined(INET)
	lro_enabled = (if_getcapenable(ifp) & IFCAP_LRO);
#endif

	/* pfil needs the vnet to be set */
	CURVNET_SET_QUIET(if_getvnet(ifp));
	for (budget_left = budget; budget_left > 0 && avail > 0;) {
		if (__predict_false(!CTX_ACTIVE(ctx))) {
			DBG_COUNTER_INC(rx_ctx_inactive);
			break;
		}
		/*
		 * Reset client set fields to their default values
		 */
		memset(&ri, 0, sizeof(ri));
		ri.iri_qsidx = rxq->ifr_id;
		ri.iri_cidx = *cidxp;
		ri.iri_ifp = ifp;
		ri.iri_frags = rxq->ifr_frags;
		err = ctx->isc_rxd_pkt_get(ctx->ifc_softc, &ri);

		if (err) {
			CURVNET_RESTORE();
			goto err;
		}
		rx_pkts += 1;
		rx_bytes += ri.iri_len;
		if (sctx->isc_flags & IFLIB_HAS_RXCQ) {
			*cidxp = ri.iri_cidx;
			/* Update our consumer index */
			/* XXX NB: shurd - check if this is still safe */
			while (rxq->ifr_cq_cidx >= scctx->isc_nrxd[0])
				rxq->ifr_cq_cidx -= scctx->isc_nrxd[0];
			/* was this only a completion queue message? */
			if (__predict_false(ri.iri_nfrags == 0))
				continue;
		}
		MPASS(ri.iri_nfrags != 0);
		MPASS(ri.iri_len != 0);

		/* will advance the cidx on the corresponding free lists */
		m = iflib_rxd_pkt_get(rxq, &ri);
		avail--;
		budget_left--;
		if (avail == 0 && budget_left)
			avail = iflib_rxd_avail(ctx, rxq, *cidxp, budget_left);

		if (__predict_false(m == NULL))
			continue;

#ifndef __NO_STRICT_ALIGNMENT
		if (!IP_ALIGNED(m) && (m = iflib_fixup_rx(m)) == NULL)
			continue;
#endif
#if defined(INET6) || defined(INET)
		if (lro_enabled) {
			tcp_lro_queue_mbuf(&rxq->ifr_lc, m);
			continue;
		}
#endif

		if (mh == NULL)
			mh = mt = m;
		else {
			mt->m_nextpkt = m;
			mt = m;
		}
	}
	CURVNET_RESTORE();
	/* make sure that we can refill faster than drain */
	for (i = 0, fl = &rxq->ifr_fl[0]; i < sctx->isc_nfl; i++, fl++)
		retval |= iflib_fl_refill_all(ctx, fl);

	if (mh != NULL) {
		if_input(ifp, mh);
		DBG_COUNTER_INC(rx_if_input);
	}

	if_inc_counter(ifp, IFCOUNTER_IBYTES, rx_bytes);
	if_inc_counter(ifp, IFCOUNTER_IPACKETS, rx_pkts);

	/*
	 * Flush any outstanding LRO work
	 */
#if defined(INET6) || defined(INET)
	tcp_lro_flush_all(&rxq->ifr_lc);
#endif
	if (avail != 0 || iflib_rxd_avail(ctx, rxq, *cidxp, 1) != 0)
		retval |= IFLIB_RXEOF_MORE;
	return (retval);
err:
	STATE_LOCK(ctx);
	ctx->ifc_flags |= IFC_DO_RESET;
	iflib_admin_intr_deferred(ctx);
	STATE_UNLOCK(ctx);
	return (0);
}

#define TXD_NOTIFY_COUNT(txq) (((txq)->ift_size / (txq)->ift_update_freq) - 1)
static inline qidx_t
txq_max_db_deferred(iflib_txq_t txq, qidx_t in_use)
{
	qidx_t notify_count = TXD_NOTIFY_COUNT(txq);
	qidx_t minthresh = txq->ift_size / 8;
	if (in_use > 4 * minthresh)
		return (notify_count);
	if (in_use > 2 * minthresh)
		return (notify_count >> 1);
	if (in_use > minthresh)
		return (notify_count >> 3);
	return (0);
}

static inline qidx_t
txq_max_rs_deferred(iflib_txq_t txq)
{
	qidx_t notify_count = TXD_NOTIFY_COUNT(txq);
	qidx_t minthresh = txq->ift_size / 8;
	if (txq->ift_in_use > 4 * minthresh)
		return (notify_count);
	if (txq->ift_in_use > 2 * minthresh)
		return (notify_count >> 1);
	if (txq->ift_in_use > minthresh)
		return (notify_count >> 2);
	return (2);
}

#define M_CSUM_FLAGS(m)		((m)->m_pkthdr.csum_flags)
#define M_HAS_VLANTAG(m)	(m->m_flags & M_VLANTAG)

#define TXQ_MAX_DB_DEFERRED(txq, in_use)	txq_max_db_deferred((txq), (in_use))
#define TXQ_MAX_RS_DEFERRED(txq)	txq_max_rs_deferred(txq)
#define TXQ_MAX_DB_CONSUMED(size)	(size >> 4)

/* forward compatibility for cxgb */
#define FIRST_QSET(ctx) 0
#define NTXQSETS(ctx) ((ctx)->ifc_softc_ctx.isc_ntxqsets)
#define NRXQSETS(ctx) ((ctx)->ifc_softc_ctx.isc_nrxqsets)
#define QIDX(ctx, m) ((((m)->m_pkthdr.flowid & ctx->ifc_softc_ctx.isc_rss_table_mask) % NTXQSETS(ctx)) + FIRST_QSET(ctx))
#define DESC_RECLAIMABLE(q) ((int)((q)->ift_processed - (q)->ift_cleaned - (q)->ift_ctx->ifc_softc_ctx.isc_tx_nsegments))

static inline bool
iflib_txd_db_check(iflib_txq_t txq, int ring)
{
	if_ctx_t ctx = txq->ift_ctx;
	qidx_t dbval, max;

	max = TXQ_MAX_DB_DEFERRED(txq, txq->ift_in_use);

	/* force || threshold exceeded || at the edge of the ring */
	if (ring || (txq->ift_db_pending >= max) || (TXQ_AVAIL(txq) <= MAX_TX_DESC(ctx))) {

		/*
		 * 'npending' is used if the card's doorbell is in terms of the number of descriptors
		 * pending flush (BRCM). 'pidx' is used in cases where the card's doorbeel uses the
		 * producer index explicitly (INTC).
		 */
		dbval = txq->ift_npending ? txq->ift_npending : txq->ift_pidx;
		bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
		ctx->isc_txd_flush(ctx->ifc_softc, txq->ift_id, dbval);

		/*
		 * Absent bugs there are zero packets pending so reset pending counts to zero.
		 */
		txq->ift_db_pending = txq->ift_npending = 0;
		return (true);
	}
	return (false);
}

#ifdef PKT_DEBUG
static void
print_pkt(if_pkt_info_t pi)
{
	printf("pi len:  %d qsidx: %d nsegs: %d ndescs: %d flags: %x pidx: %d\n",
	    pi->ipi_len, pi->ipi_qsidx, pi->ipi_nsegs, pi->ipi_ndescs, pi->ipi_flags, pi->ipi_pidx);
	printf("pi new_pidx: %d csum_flags: %lx tso_segsz: %d mflags: %x vtag: %d\n",
	    pi->ipi_new_pidx, pi->ipi_csum_flags, pi->ipi_tso_segsz, pi->ipi_mflags, pi->ipi_vtag);
	printf("pi etype: %d ehdrlen: %d ip_hlen: %d ipproto: %d\n",
	    pi->ipi_etype, pi->ipi_ehdrlen, pi->ipi_ip_hlen, pi->ipi_ipproto);
}
#endif

#define IS_TSO4(pi) ((pi)->ipi_csum_flags & CSUM_IP_TSO)
#define IS_TX_OFFLOAD4(pi) ((pi)->ipi_csum_flags & (CSUM_IP_TCP | CSUM_IP_TSO))
#define IS_TSO6(pi) ((pi)->ipi_csum_flags & CSUM_IP6_TSO)
#define IS_TX_OFFLOAD6(pi) ((pi)->ipi_csum_flags & (CSUM_IP6_TCP | CSUM_IP6_TSO))

/**
 * Parses out ethernet header information in the given mbuf.
 * Returns in pi: ipi_etype (EtherType) and ipi_ehdrlen (Ethernet header length)
 *
 * This will account for the VLAN header if present.
 *
 * XXX: This doesn't handle QinQ, which could prevent TX offloads for those
 * types of packets.
 */
static int
iflib_parse_ether_header(if_pkt_info_t pi, struct mbuf **mp, uint64_t *pullups)
{
	struct ether_vlan_header *eh;
	struct mbuf *m;

	m = *mp;
	if (__predict_false(m->m_len < sizeof(*eh))) {
		(*pullups)++;
		if (__predict_false((m = m_pullup(m, sizeof(*eh))) == NULL))
			return (ENOMEM);
	}
	eh = mtod(m, struct ether_vlan_header *);
	if (eh->evl_encap_proto == htons(ETHERTYPE_VLAN)) {
		pi->ipi_etype = ntohs(eh->evl_proto);
		pi->ipi_ehdrlen = ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
	} else {
		pi->ipi_etype = ntohs(eh->evl_encap_proto);
		pi->ipi_ehdrlen = ETHER_HDR_LEN;
	}
	*mp = m;

	return (0);
}

/**
 * Parse up to the L3 header and extract IPv4/IPv6 header information into pi.
 * Currently this information includes: IP ToS value, IP header version/presence
 *
 * This is missing some checks and doesn't edit the packet content as it goes,
 * unlike iflib_parse_header(), in order to keep the amount of code here minimal.
 */
static int
iflib_parse_header_partial(if_pkt_info_t pi, struct mbuf **mp, uint64_t *pullups)
{
	struct mbuf *m;
	int err;

	*pullups = 0;
	m = *mp;
	if (!M_WRITABLE(m)) {
		m = m_dup(m, M_NOWAIT);
		m_freem(*mp);
		DBG_COUNTER_INC(tx_frees);
		*mp = m;
		if (m == NULL)
			return (ENOMEM);
	}

	/* Fills out pi->ipi_etype */
	err = iflib_parse_ether_header(pi, mp, pullups);
	if (err)
		return (err);
	m = *mp;

	switch (pi->ipi_etype) {
#ifdef INET
	case ETHERTYPE_IP:
	{
		struct mbuf *n;
		struct ip *ip = NULL;
		int miniplen;

		miniplen = min(m->m_pkthdr.len, pi->ipi_ehdrlen + sizeof(*ip));
		if (__predict_false(m->m_len < miniplen)) {
			/*
			 * Check for common case where the first mbuf only contains
			 * the Ethernet header
			 */
			if (m->m_len == pi->ipi_ehdrlen) {
				n = m->m_next;
				MPASS(n);
				/* If next mbuf contains at least the minimal IP header, then stop */
				if (n->m_len >= sizeof(*ip)) {
					ip = (struct ip *)n->m_data;
				} else {
					(*pullups)++;
					if (__predict_false((m = m_pullup(m, miniplen)) == NULL))
						return (ENOMEM);
					ip = (struct ip *)(m->m_data + pi->ipi_ehdrlen);
				}
			} else {
				(*pullups)++;
				if (__predict_false((m = m_pullup(m, miniplen)) == NULL))
					return (ENOMEM);
				ip = (struct ip *)(m->m_data + pi->ipi_ehdrlen);
			}
		} else {
			ip = (struct ip *)(m->m_data + pi->ipi_ehdrlen);
		}

		/* Have the IPv4 header w/ no options here */
		pi->ipi_ip_hlen = ip->ip_hl << 2;
		pi->ipi_ipproto = ip->ip_p;
		pi->ipi_ip_tos = ip->ip_tos;
		pi->ipi_flags |= IPI_TX_IPV4;

		break;
	}
#endif
#ifdef INET6
	case ETHERTYPE_IPV6:
	{
		struct ip6_hdr *ip6;

		if (__predict_false(m->m_len < pi->ipi_ehdrlen + sizeof(struct ip6_hdr))) {
			(*pullups)++;
			if (__predict_false((m = m_pullup(m, pi->ipi_ehdrlen + sizeof(struct ip6_hdr))) == NULL))
				return (ENOMEM);
		}
		ip6 = (struct ip6_hdr *)(m->m_data + pi->ipi_ehdrlen);

		/* Have the IPv6 fixed header here */
		pi->ipi_ip_hlen = sizeof(struct ip6_hdr);
		pi->ipi_ipproto = ip6->ip6_nxt;
		pi->ipi_ip_tos = IPV6_TRAFFIC_CLASS(ip6);
		pi->ipi_flags |= IPI_TX_IPV6;

		break;
	}
#endif
	default:
		pi->ipi_csum_flags &= ~CSUM_OFFLOAD;
		pi->ipi_ip_hlen = 0;
		break;
	}
	*mp = m;

	return (0);

}

static int
iflib_parse_header(iflib_txq_t txq, if_pkt_info_t pi, struct mbuf **mp)
{
	if_shared_ctx_t sctx = txq->ift_ctx->ifc_sctx;
	struct mbuf *m;
	int err;

	m = *mp;
	if ((sctx->isc_flags & IFLIB_NEED_SCRATCH) &&
	    M_WRITABLE(m) == 0) {
		m = m_dup(m, M_NOWAIT);
		m_freem(*mp);
		DBG_COUNTER_INC(tx_frees);
		*mp = m;
		if (m == NULL)
			return (ENOMEM);
	}

	/* Fills out pi->ipi_etype */
	err = iflib_parse_ether_header(pi, mp, &txq->ift_pullups);
	if (__predict_false(err))
		return (err);
	m = *mp;

	switch (pi->ipi_etype) {
#ifdef INET
	case ETHERTYPE_IP:
	{
		struct ip *ip;
		struct tcphdr *th;
		uint8_t hlen;

		hlen = pi->ipi_ehdrlen + sizeof(*ip);
		if (__predict_false(m->m_len < hlen)) {
			txq->ift_pullups++;
			if (__predict_false((m = m_pullup(m, hlen)) == NULL))
				return (ENOMEM);
		}
		ip = (struct ip *)(m->m_data + pi->ipi_ehdrlen);
		hlen = pi->ipi_ehdrlen + (ip->ip_hl << 2);
		if (ip->ip_p == IPPROTO_TCP) {
			hlen += sizeof(*th);
			th = (struct tcphdr *)((char *)ip + (ip->ip_hl << 2));
		} else if (ip->ip_p == IPPROTO_UDP) {
			hlen += sizeof(struct udphdr);
		}
		if (__predict_false(m->m_len < hlen)) {
			txq->ift_pullups++;
			if ((m = m_pullup(m, hlen)) == NULL)
				return (ENOMEM);
			/* reset pointers after pullup */
			ip = (struct ip *)(m->m_data + pi->ipi_ehdrlen);
			th = (struct tcphdr *)((char *)ip + (ip->ip_hl << 2));
		}
		pi->ipi_ip_hlen = ip->ip_hl << 2;
		pi->ipi_ipproto = ip->ip_p;
		pi->ipi_ip_tos = ip->ip_tos;
		pi->ipi_flags |= IPI_TX_IPV4;

		/* TCP checksum offload may require TCP header length */
		if (IS_TX_OFFLOAD4(pi)) {
			if (__predict_true(pi->ipi_ipproto == IPPROTO_TCP)) {
				pi->ipi_tcp_hflags = tcp_get_flags(th);
				pi->ipi_tcp_hlen = th->th_off << 2;
				pi->ipi_tcp_seq = th->th_seq;
			}
			if (IS_TSO4(pi)) {
				MPASS(ip->ip_p == IPPROTO_TCP);
				/*
				 * TSO always requires hardware checksum offload.
				 */
				pi->ipi_csum_flags |= (CSUM_IP_TCP | CSUM_IP);
				th->th_sum = in_pseudo(ip->ip_src.s_addr,
						       ip->ip_dst.s_addr, htons(IPPROTO_TCP));
				pi->ipi_tso_segsz = m->m_pkthdr.tso_segsz;
				if (sctx->isc_flags & IFLIB_TSO_INIT_IP) {
					ip->ip_sum = 0;
					ip->ip_len = htons(pi->ipi_ip_hlen + pi->ipi_tcp_hlen + pi->ipi_tso_segsz);
				}
			}
		}
		if ((sctx->isc_flags & IFLIB_NEED_ZERO_CSUM) && (pi->ipi_csum_flags & CSUM_IP))
			ip->ip_sum = 0;

		break;
	}
#endif
#ifdef INET6
	case ETHERTYPE_IPV6:
	{
		struct ip6_hdr *ip6 = (struct ip6_hdr *)(m->m_data + pi->ipi_ehdrlen);
		struct tcphdr *th;
		pi->ipi_ip_hlen = sizeof(struct ip6_hdr);

		if (__predict_false(m->m_len < pi->ipi_ehdrlen + sizeof(struct ip6_hdr))) {
			txq->ift_pullups++;
			if (__predict_false((m = m_pullup(m, pi->ipi_ehdrlen + sizeof(struct ip6_hdr))) == NULL))
				return (ENOMEM);
			/* reset pointers after pullup */
			ip6 = (struct ip6_hdr *)(m->m_data + pi->ipi_ehdrlen);
		}
		th = (struct tcphdr *)((caddr_t)ip6 + pi->ipi_ip_hlen);

		/* XXX-BZ this will go badly in case of ext hdrs. */
		pi->ipi_ipproto = ip6->ip6_nxt;
		pi->ipi_ip_tos = IPV6_TRAFFIC_CLASS(ip6);
		pi->ipi_flags |= IPI_TX_IPV6;

		/* TCP checksum offload may require TCP header length */
		if (IS_TX_OFFLOAD6(pi)) {
			if (pi->ipi_ipproto == IPPROTO_TCP) {
				if (__predict_false(m->m_len < pi->ipi_ehdrlen + sizeof(struct ip6_hdr) + sizeof(struct tcphdr))) {
					txq->ift_pullups++;
					if (__predict_false((m = m_pullup(m, pi->ipi_ehdrlen + sizeof(struct ip6_hdr) + sizeof(struct tcphdr))) == NULL))
						return (ENOMEM);
					/* reset pointers after pullup */
					ip6 = (struct ip6_hdr *)(m->m_data + pi->ipi_ehdrlen);
					th = (struct tcphdr *)((caddr_t)ip6 + pi->ipi_ip_hlen);
				}
				pi->ipi_tcp_hflags = tcp_get_flags(th);
				pi->ipi_tcp_hlen = th->th_off << 2;
				pi->ipi_tcp_seq = th->th_seq;
			}
			if (IS_TSO6(pi)) {
				MPASS(ip6->ip6_nxt == IPPROTO_TCP);
				/*
				 * TSO always requires hardware checksum offload.
				 */
				pi->ipi_csum_flags |= CSUM_IP6_TCP;
				th->th_sum = in6_cksum_pseudo(ip6, 0, IPPROTO_TCP, 0);
				pi->ipi_tso_segsz = m->m_pkthdr.tso_segsz;
			}
		}
		break;
	}
#endif
	default:
		pi->ipi_csum_flags &= ~CSUM_OFFLOAD;
		pi->ipi_ip_hlen = 0;
		break;
	}
	*mp = m;

	return (0);
}

/*
 * If dodgy hardware rejects the scatter gather chain we've handed it
 * we'll need to remove the mbuf chain from ifsg_m[] before we can add the
 * m_defrag'd mbufs
 */
static __noinline struct mbuf *
iflib_remove_mbuf(iflib_txq_t txq)
{
	int ntxd, pidx;
	struct mbuf *m, **ifsd_m;

	ifsd_m = txq->ift_sds.ifsd_m;
	ntxd = txq->ift_size;
	pidx = txq->ift_pidx & (ntxd - 1);
	ifsd_m = txq->ift_sds.ifsd_m;
	m = IFLIB_GET_MBUF(ifsd_m[pidx]);
	ifsd_m[pidx] = NULL;
	bus_dmamap_unload(txq->ift_buf_tag, txq->ift_sds.ifsd_map[pidx]);
	if (txq->ift_sds.ifsd_tso_map != NULL)
		bus_dmamap_unload(txq->ift_tso_buf_tag,
		    txq->ift_sds.ifsd_tso_map[pidx]);
#if MEMORY_LOGGING
	txq->ift_dequeued++;
#endif
	return (m);
}

/*
 * Pad an mbuf to ensure a minimum ethernet frame size.
 * min_frame_size is the frame size (less CRC) to pad the mbuf to
 */
static __noinline int
iflib_ether_pad(device_t dev, struct mbuf **m_head, uint16_t min_frame_size)
{
	/*
	 * 18 is enough bytes to pad an ARP packet to 46 bytes, and
	 * and ARP message is the smallest common payload I can think of
	 */
	static char pad[18];	/* just zeros */
	int n;
	struct mbuf *new_head;

	if (!M_WRITABLE(*m_head)) {
		new_head = m_dup(*m_head, M_NOWAIT);
		m_freem(*m_head);
		*m_head = new_head;
		if (new_head == NULL) {
			device_printf(dev, "cannot pad short frame, m_dup() failed");
			DBG_COUNTER_INC(encap_pad_mbuf_fail);
			DBG_COUNTER_INC(tx_frees);
			return (ENOMEM);
		}
	}

	for (n = min_frame_size - (*m_head)->m_pkthdr.len;
	     n > 0; n -= sizeof(pad))
		if (!m_append(*m_head, min(n, sizeof(pad)), pad))
			break;

	if (n > 0) {
		m_freem(*m_head);
		*m_head = NULL;
		device_printf(dev, "cannot pad short frame\n");
		DBG_COUNTER_INC(encap_pad_mbuf_fail);
		DBG_COUNTER_INC(tx_frees);
		return (ENOMEM);
	}

	return (0);
}

static int
iflib_encap(iflib_txq_t txq, struct mbuf **m_headp, int *obytes, int *opkts)
{
	if_ctx_t		ctx;
	if_shared_ctx_t		sctx;
	if_softc_ctx_t		scctx;
	bus_dma_tag_t		buf_tag;
	bus_dma_segment_t	*segs;
	struct mbuf		*m_head, **ifsd_m;
	bus_dmamap_t		map;
	struct if_pkt_info	pi;
	uintptr_t		flags;
	int remap = 0;
	int err, nsegs, ndesc, max_segs, pidx;

	ctx = txq->ift_ctx;
	sctx = ctx->ifc_sctx;
	scctx = &ctx->ifc_softc_ctx;
	segs = txq->ift_segs;
	m_head = *m_headp;
	map = NULL;

	/*
	 * If we're doing TSO the next descriptor to clean may be quite far ahead
	 */
	pidx = txq->ift_pidx;
	map = txq->ift_sds.ifsd_map[pidx];
	ifsd_m = txq->ift_sds.ifsd_m;

	if (m_head->m_pkthdr.csum_flags & CSUM_TSO) {
		buf_tag = txq->ift_tso_buf_tag;
		max_segs = scctx->isc_tx_tso_segments_max;
		map = txq->ift_sds.ifsd_tso_map[pidx];
		MPASS(buf_tag != NULL);
		MPASS(max_segs > 0);
		flags = IFLIB_TSO;
	} else {
		buf_tag = txq->ift_buf_tag;
		max_segs = scctx->isc_tx_nsegments;
		map = txq->ift_sds.ifsd_map[pidx];
		flags = IFLIB_NO_TSO;
	}
	if ((sctx->isc_flags & IFLIB_NEED_ETHER_PAD) &&
	    __predict_false(m_head->m_pkthdr.len < scctx->isc_min_frame_size)) {
		err = iflib_ether_pad(ctx->ifc_dev, m_headp, scctx->isc_min_frame_size);
		if (err) {
			DBG_COUNTER_INC(encap_txd_encap_fail);
			return (err);
		}
	}
	m_head = *m_headp;

	memset(&pi, 0, sizeof(pi));
	pi.ipi_mflags = (m_head->m_flags & (M_VLANTAG | M_BCAST | M_MCAST));
	pi.ipi_pidx = pidx;
	pi.ipi_qsidx = txq->ift_id;
	pi.ipi_len = m_head->m_pkthdr.len;
	pi.ipi_csum_flags = m_head->m_pkthdr.csum_flags;
	pi.ipi_vtag = M_HAS_VLANTAG(m_head) ? m_head->m_pkthdr.ether_vtag : 0;

	/* deliberate bitwise OR to make one condition */
	if (__predict_true((pi.ipi_csum_flags | pi.ipi_vtag))) {
		if (__predict_false((err = iflib_parse_header(txq, &pi, m_headp)) != 0)) {
			DBG_COUNTER_INC(encap_txd_encap_fail);
			return (err);
		}
		m_head = *m_headp;
	}

retry:
	err = bus_dmamap_load_mbuf_sg(buf_tag, map, m_head, segs, &nsegs,
	    BUS_DMA_NOWAIT);
defrag:
	if (__predict_false(err)) {
		switch (err) {
		case EFBIG:
			/* try collapse once and defrag once */
			if (remap == 0) {
				m_head = m_collapse(*m_headp, M_NOWAIT, max_segs);
				/* try defrag if collapsing fails */
				if (m_head == NULL)
					remap++;
			}
			if (remap == 1) {
				txq->ift_mbuf_defrag++;
				m_head = m_defrag(*m_headp, M_NOWAIT);
			}
			/*
			 * remap should never be >1 unless bus_dmamap_load_mbuf_sg
			 * failed to map an mbuf that was run through m_defrag
			 */
			MPASS(remap <= 1);
			if (__predict_false(m_head == NULL || remap > 1))
				goto defrag_failed;
			remap++;
			*m_headp = m_head;
			goto retry;
			break;
		case ENOMEM:
			/* FALLTHROUGH */
		default:
			txq->ift_no_tx_dma_setup++;
			m_freem(*m_headp);
			DBG_COUNTER_INC(tx_frees);
			*m_headp = NULL;
			break;
		}
		txq->ift_map_failed++;
		DBG_COUNTER_INC(encap_load_mbuf_fail);
		DBG_COUNTER_INC(encap_txd_encap_fail);
		return (err);
	}
	ifsd_m[pidx] = IFLIB_SAVE_MBUF(m_head, flags);
	if (m_head->m_pkthdr.csum_flags & CSUM_SND_TAG)
		pi.ipi_mbuf = m_head;
	else
		pi.ipi_mbuf = NULL;
	/*
	 * XXX assumes a 1 to 1 relationship between segments and
	 *        descriptors - this does not hold true on all drivers, e.g.
	 *        cxgb
	 */
	if (__predict_false(nsegs > TXQ_AVAIL(txq))) {
		iflib_completed_tx_reclaim_force(txq);
		if (__predict_false(nsegs > TXQ_AVAIL(txq))) {
			txq->ift_no_desc_avail++;
			bus_dmamap_unload(buf_tag, map);
			DBG_COUNTER_INC(encap_txq_avail_fail);
			DBG_COUNTER_INC(encap_txd_encap_fail);
			if (ctx->ifc_sysctl_simple_tx) {
				*m_headp = m_head = iflib_remove_mbuf(txq);
				m_freem(*m_headp);
				DBG_COUNTER_INC(tx_frees);
				*m_headp = NULL;
			}
			if ((txq->ift_task.gt_task.ta_flags & TASK_ENQUEUED) == 0)
				GROUPTASK_ENQUEUE(&txq->ift_task);
			return (ENOBUFS);
		}
	}
	/*
	 * On Intel cards we can greatly reduce the number of TX interrupts
	 * we see by only setting report status on every Nth descriptor.
	 * However, this also means that the driver will need to keep track
	 * of the descriptors that RS was set on to check them for the DD bit.
	 */
	if (txq->ift_rs_pending + nsegs + 1 > TXQ_MAX_RS_DEFERRED(txq) ||
	    iflib_no_tx_batch || (TXQ_AVAIL(txq) - nsegs) <= MAX_TX_DESC(ctx)) {
		pi.ipi_flags |= IPI_TX_INTR;
	}

	pi.ipi_segs = segs;
	pi.ipi_nsegs = nsegs;

	MPASS(pidx >= 0 && pidx < txq->ift_size);
#ifdef PKT_DEBUG
	print_pkt(&pi);
#endif
	if ((err = ctx->isc_txd_encap(ctx->ifc_softc, &pi)) == 0) {
		bus_dmamap_sync(buf_tag, map, BUS_DMASYNC_PREWRITE);
		DBG_COUNTER_INC(tx_encap);
		MPASS(pi.ipi_new_pidx < txq->ift_size);

		ndesc = pi.ipi_new_pidx - pi.ipi_pidx;
		if (pi.ipi_new_pidx < pi.ipi_pidx) {
			ndesc += txq->ift_size;
			txq->ift_gen = 1;
		}

		if (pi.ipi_flags & IPI_TX_INTR)
			txq->ift_rs_pending = 0;
		else
			txq->ift_rs_pending += ndesc;
		/*
		 * drivers can need up to ift_pad sentinels
		 */
		MPASS(ndesc <= pi.ipi_nsegs + txq->ift_pad);
		MPASS(pi.ipi_new_pidx != pidx);
		MPASS(ndesc > 0);
		txq->ift_in_use += ndesc;
		txq->ift_db_pending += ndesc;

		/*
		 * We update the last software descriptor again here because there may
		 * be a sentinel and/or there may be more mbufs than segments
		 */
		txq->ift_pidx = pi.ipi_new_pidx;
		txq->ift_npending += pi.ipi_ndescs;

		/*
		 * Update packets / bytes sent
		 */
		if (flags & IFLIB_TSO) {
			int hlen = pi.ipi_ehdrlen + pi.ipi_ip_hlen + pi.ipi_tcp_hlen;
			int tsolen = pi.ipi_len - hlen;
			int nsegs = (tsolen + pi.ipi_tso_segsz - 1) / pi.ipi_tso_segsz;
			*obytes += tsolen + nsegs * hlen;
			*opkts += nsegs;
		} else {
			*obytes += pi.ipi_len;
			*opkts += 1;
		}
	} else {
		*m_headp = m_head = iflib_remove_mbuf(txq);
		if (err == EFBIG) {
			txq->ift_txd_encap_efbig++;
			if (remap < 2) {
				remap = 1;
				goto defrag;
			}
			goto defrag_failed;
		}
		/* mp_ring assumes ENOBUFS means we didn't consume the mbuf */
		if (err == ENOBUFS && !ctx->ifc_sysctl_simple_tx)
			err = ENOMEM;
		goto out_with_error;
	}
	/*
	 * err can't possibly be non-zero here, so we don't neet to test it
	 * to see if we need to DBG_COUNTER_INC(encap_txd_encap_fail).
	 */
	return (err);

defrag_failed:
	err = ENOMEM;
	txq->ift_mbuf_defrag_failed++;
out_with_error:
	txq->ift_map_failed++;
	m_freem(*m_headp);
	DBG_COUNTER_INC(tx_frees);
	*m_headp = NULL;
	DBG_COUNTER_INC(encap_txd_encap_fail);
	return (err);
}

static void
iflib_tx_desc_free(iflib_txq_t txq, int n, struct mbuf **m_defer)
{
	uint32_t qsize, cidx, gen;
	struct mbuf *m, **ifsd_m;
	uintptr_t flags;

	cidx = txq->ift_cidx;
	gen = txq->ift_gen;
	qsize = txq->ift_size;
	ifsd_m =txq->ift_sds.ifsd_m;

	while (n-- > 0) {
		if ((m = IFLIB_GET_MBUF(ifsd_m[cidx])) != NULL) {
			flags = IFLIB_GET_FLAGS(ifsd_m[cidx]);
			MPASS(flags != 0);
			if (flags & IFLIB_TSO) {
				bus_dmamap_sync(txq->ift_tso_buf_tag,
				    txq->ift_sds.ifsd_tso_map[cidx],
				    BUS_DMASYNC_POSTWRITE);
				bus_dmamap_unload(txq->ift_tso_buf_tag,
				    txq->ift_sds.ifsd_tso_map[cidx]);
			} else {
				bus_dmamap_sync(txq->ift_buf_tag,
				    txq->ift_sds.ifsd_map[cidx],
				    BUS_DMASYNC_POSTWRITE);
				bus_dmamap_unload(txq->ift_buf_tag,
				    txq->ift_sds.ifsd_map[cidx]);
			}
			/* XXX we don't support any drivers that batch packets yet */
			MPASS(m->m_nextpkt == NULL);
			if (m_defer == NULL) {
				m_freem(m);
			} else if (m != NULL) {
				*m_defer = m;
				m_defer++;
			}
			ifsd_m[cidx] = NULL;
#if MEMORY_LOGGING
			txq->ift_dequeued++;
#endif
			DBG_COUNTER_INC(tx_frees);
		}
		if (__predict_false(++cidx == qsize)) {
			cidx = 0;
			gen = 0;
		}
	}
	txq->ift_cidx = cidx;
	txq->ift_gen = gen;
}

static __inline int
iflib_txq_can_reclaim(iflib_txq_t txq)
{
	int reclaim, thresh;

	thresh = txq->ift_reclaim_thresh;
	KASSERT(thresh >= 0, ("invalid threshold to reclaim"));
	MPASS(thresh /*+ MAX_TX_DESC(txq->ift_ctx) */ < txq->ift_size);

	if (ticks <= (txq->ift_last_reclaim + txq->ift_reclaim_ticks) &&
	    txq->ift_in_use < thresh)
		return (false);
	iflib_tx_credits_update(txq->ift_ctx, txq);
	reclaim = DESC_RECLAIMABLE(txq);
	if (reclaim <= thresh) {
#ifdef INVARIANTS
		if (iflib_verbose_debug) {
			printf("%s processed=%ju cleaned=%ju tx_nsegments=%d reclaim=%d thresh=%d\n", __func__,
			    txq->ift_processed, txq->ift_cleaned, txq->ift_ctx->ifc_softc_ctx.isc_tx_nsegments,
			    reclaim, thresh);
		}
#endif
		return (0);
	}
	return (reclaim);
}

static __inline void
_iflib_completed_tx_reclaim(iflib_txq_t txq, struct mbuf **m_defer, int reclaim)
{
	txq->ift_last_reclaim = ticks;
	iflib_tx_desc_free(txq, reclaim, m_defer);
	txq->ift_cleaned += reclaim;
	txq->ift_in_use -= reclaim;
}

static __inline int
iflib_completed_tx_reclaim(iflib_txq_t txq, struct mbuf **m_defer)
{
	int reclaim;

	reclaim = iflib_txq_can_reclaim(txq);
	if (reclaim <= 0)
		return (0);
	_iflib_completed_tx_reclaim(txq, m_defer, reclaim);
	return (reclaim);
}

/*
 * Reclaim any transmit descriptors possible, ignoring coalescing
 */
static __inline void
iflib_completed_tx_reclaim_force(iflib_txq_t txq)
{
	int reclaim;

	iflib_tx_credits_update(txq->ift_ctx, txq);
	reclaim = DESC_RECLAIMABLE(txq);
	if (reclaim != 0)
		_iflib_completed_tx_reclaim(txq, NULL, reclaim);
}

static struct mbuf **
_ring_peek_one(struct ifmp_ring *r, int cidx, int offset, int remaining)
{
	int next, size;
	struct mbuf **items;

	size = r->size;
	next = (cidx + CACHE_PTR_INCREMENT) & (size - 1);
	items = __DEVOLATILE(struct mbuf **, &r->items[0]);

	prefetch(items[(cidx + offset) & (size - 1)]);
	if (remaining > 1) {
		prefetch2cachelines(&items[next]);
		prefetch2cachelines(items[(cidx + offset + 1) & (size - 1)]);
		prefetch2cachelines(items[(cidx + offset + 2) & (size - 1)]);
		prefetch2cachelines(items[(cidx + offset + 3) & (size - 1)]);
	}
	return (__DEVOLATILE(struct mbuf **, &r->items[(cidx + offset) & (size - 1)]));
}

static void
iflib_txq_check_drain(iflib_txq_t txq, int budget)
{

	ifmp_ring_check_drainage(txq->ift_br, budget);
}

static uint32_t
iflib_txq_can_drain(struct ifmp_ring *r)
{
	iflib_txq_t txq = r->cookie;
	if_ctx_t ctx = txq->ift_ctx;

	if (TXQ_AVAIL(txq) > MAX_TX_DESC(ctx))
		return (1);
	bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
	    BUS_DMASYNC_POSTREAD);
	return (ctx->isc_txd_credits_update(ctx->ifc_softc, txq->ift_id,
	    false));
}

static uint32_t
iflib_txq_drain(struct ifmp_ring *r, uint32_t cidx, uint32_t pidx)
{
	iflib_txq_t txq = r->cookie;
	if_ctx_t ctx = txq->ift_ctx;
	if_t ifp = ctx->ifc_ifp;
	struct mbuf *m, **mp;
	int avail, bytes_sent, consumed, count, err, i;
	int mcast_sent, pkt_sent, reclaimed;
	bool do_prefetch, rang, ring;

	if (__predict_false(!(if_getdrvflags(ifp) & IFF_DRV_RUNNING) ||
			    !LINK_ACTIVE(ctx))) {
		DBG_COUNTER_INC(txq_drain_notready);
		return (0);
	}
	reclaimed = iflib_completed_tx_reclaim(txq, NULL);
	rang = iflib_txd_db_check(txq, reclaimed && txq->ift_db_pending);
	avail = IDXDIFF(pidx, cidx, r->size);

	if (__predict_false(ctx->ifc_flags & IFC_QFLUSH)) {
		/*
		 * The driver is unloading so we need to free all pending packets.
		 */
		DBG_COUNTER_INC(txq_drain_flushing);
		for (i = 0; i < avail; i++) {
			if (__predict_true(r->items[(cidx + i) & (r->size - 1)] != (void *)txq))
				m_freem(r->items[(cidx + i) & (r->size - 1)]);
			r->items[(cidx + i) & (r->size - 1)] = NULL;
		}
		return (avail);
	}

	if (__predict_false(if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_OACTIVE)) {
		CALLOUT_LOCK(txq);
		callout_stop(&txq->ift_timer);
		CALLOUT_UNLOCK(txq);
		DBG_COUNTER_INC(txq_drain_oactive);
		return (0);
	}

	consumed = mcast_sent = bytes_sent = pkt_sent = 0;
	count = MIN(avail, TX_BATCH_SIZE);
#ifdef INVARIANTS
	if (iflib_verbose_debug)
		printf("%s avail=%d ifc_flags=%x txq_avail=%d ", __func__,
		    avail, ctx->ifc_flags, TXQ_AVAIL(txq));
#endif
	do_prefetch = (ctx->ifc_flags & IFC_PREFETCH);
	err = 0;
	for (i = 0; i < count && TXQ_AVAIL(txq) >= MAX_TX_DESC(ctx); i++) {
		int rem = do_prefetch ? count - i : 0;

		mp = _ring_peek_one(r, cidx, i, rem);
		MPASS(mp != NULL && *mp != NULL);

		/*
		 * Completion interrupts will use the address of the txq
		 * as a sentinel to enqueue _something_ in order to acquire
		 * the lock on the mp_ring (there's no direct lock call).
		 * We obviously whave to check for these sentinel cases
		 * and skip them.
		 */
		if (__predict_false(*mp == (struct mbuf *)txq)) {
			consumed++;
			continue;
		}
		err = iflib_encap(txq, mp, &bytes_sent, &pkt_sent);
		if (__predict_false(err)) {
			/* no room - bail out */
			if (err == ENOBUFS)
				break;
			consumed++;
			/* we can't send this packet - skip it */
			continue;
		}
		consumed++;
		m = *mp;
		DBG_COUNTER_INC(tx_sent);
		mcast_sent += !!(m->m_flags & M_MCAST);

		if (__predict_false(!(if_getdrvflags(ifp) & IFF_DRV_RUNNING)))
			break;
		ETHER_BPF_MTAP(ifp, m);
		rang = iflib_txd_db_check(txq, false);
	}

	/* deliberate use of bitwise or to avoid gratuitous short-circuit */
	ring = rang ? false  : (iflib_min_tx_latency | err | (!!txq->ift_reclaim_thresh));
	iflib_txd_db_check(txq, ring);
	if_inc_counter(ifp, IFCOUNTER_OBYTES, bytes_sent);
	if_inc_counter(ifp, IFCOUNTER_OPACKETS, pkt_sent);
	if (mcast_sent)
		if_inc_counter(ifp, IFCOUNTER_OMCASTS, mcast_sent);
#ifdef INVARIANTS
	if (iflib_verbose_debug)
		printf("consumed=%d\n", consumed);
#endif
	return (consumed);
}

static uint32_t
iflib_txq_drain_always(struct ifmp_ring *r)
{
	return (1);
}

static uint32_t
iflib_txq_drain_free(struct ifmp_ring *r, uint32_t cidx, uint32_t pidx)
{
	int i, avail;
	struct mbuf **mp;
	iflib_txq_t txq;

	txq = r->cookie;

	CALLOUT_LOCK(txq);
	callout_stop(&txq->ift_timer);
	CALLOUT_UNLOCK(txq);

	avail = IDXDIFF(pidx, cidx, r->size);
	for (i = 0; i < avail; i++) {
		mp = _ring_peek_one(r, cidx, i, avail - i);
		if (__predict_false(*mp == (struct mbuf *)txq))
			continue;
		m_freem(*mp);
		DBG_COUNTER_INC(tx_frees);
	}
	MPASS(ifmp_ring_is_stalled(r) == 0);
	return (avail);
}

static void
iflib_ifmp_purge(iflib_txq_t txq)
{
	struct ifmp_ring *r;

	r = txq->ift_br;
	r->drain = iflib_txq_drain_free;
	r->can_drain = iflib_txq_drain_always;

	ifmp_ring_check_drainage(r, r->size);

	r->drain = iflib_txq_drain;
	r->can_drain = iflib_txq_can_drain;
}

static void
_task_fn_tx(void *context)
{
	iflib_txq_t txq = context;
	if_ctx_t ctx = txq->ift_ctx;
	if_t ifp = ctx->ifc_ifp;
	int abdicate = ctx->ifc_sysctl_tx_abdicate;

#ifdef IFLIB_DIAGNOSTICS
	txq->ift_cpu_exec_count[curcpu]++;
#endif
	if (!(if_getdrvflags(ifp) & IFF_DRV_RUNNING))
		return;
#ifdef DEV_NETMAP
	if ((if_getcapenable(ifp) & IFCAP_NETMAP) &&
	    netmap_tx_irq(ifp, txq->ift_id))
		goto skip_ifmp;
#endif
	if (ctx->ifc_sysctl_simple_tx) {
		iflib_simple_txq_drain(txq);
		goto skip_ifmp;
	}
#ifdef ALTQ
	if (if_altq_is_enabled(ifp))
		iflib_altq_if_start(ifp);
#endif
	if (txq->ift_db_pending)
		ifmp_ring_enqueue(txq->ift_br, (void **)&txq, 1, TX_BATCH_SIZE, abdicate);
	else if (!abdicate)
		ifmp_ring_check_drainage(txq->ift_br, TX_BATCH_SIZE);
	/*
	 * When abdicating, we always need to check drainage, not just when we don't enqueue
	 */
	if (abdicate)
		ifmp_ring_check_drainage(txq->ift_br, TX_BATCH_SIZE);

skip_ifmp:
	if (ctx->ifc_flags & IFC_LEGACY)
		IFDI_INTR_ENABLE(ctx);
	else
		IFDI_TX_QUEUE_INTR_ENABLE(ctx, txq->ift_id);
}

static void
_task_fn_rx(void *context)
{
	iflib_rxq_t rxq = context;
	if_ctx_t ctx = rxq->ifr_ctx;
	uint8_t more;
	uint16_t budget;
#ifdef DEV_NETMAP
	u_int work = 0;
	int nmirq;
#endif

#ifdef IFLIB_DIAGNOSTICS
	rxq->ifr_cpu_exec_count[curcpu]++;
#endif
	DBG_COUNTER_INC(task_fn_rxs);
	if (__predict_false(!(if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING)))
		return;
#ifdef DEV_NETMAP
	nmirq = netmap_rx_irq(ctx->ifc_ifp, rxq->ifr_id, &work);
	if (nmirq != NM_IRQ_PASS) {
		more = (nmirq == NM_IRQ_RESCHED) ? IFLIB_RXEOF_MORE : 0;
		goto skip_rxeof;
	}
#endif
	budget = ctx->ifc_sysctl_rx_budget;
	if (budget == 0)
		budget = 16;	/* XXX */
	more = iflib_rxeof(rxq, budget);
#ifdef DEV_NETMAP
skip_rxeof:
#endif
	if ((more & IFLIB_RXEOF_MORE) == 0) {
		if (ctx->ifc_flags & IFC_LEGACY)
			IFDI_INTR_ENABLE(ctx);
		else
			IFDI_RX_QUEUE_INTR_ENABLE(ctx, rxq->ifr_id);
		DBG_COUNTER_INC(rx_intr_enables);
	}
	if (__predict_false(!(if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING)))
		return;

	if (more & IFLIB_RXEOF_MORE)
		GROUPTASK_ENQUEUE(&rxq->ifr_task);
	else if (more & IFLIB_RXEOF_EMPTY)
		callout_reset_curcpu(&rxq->ifr_watchdog, 1, &_task_fn_rx_watchdog, rxq);
}

static void
_task_fn_admin(void *context, int pending)
{
	if_ctx_t ctx = context;
	if_softc_ctx_t sctx = &ctx->ifc_softc_ctx;
	iflib_txq_t txq;
	int i;
	bool oactive, running, do_reset, do_reset_if_up, do_watchdog;
	bool in_detach;

	STATE_LOCK(ctx);
	running = (if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING);
	oactive = (if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_OACTIVE);
	do_reset = (ctx->ifc_flags & IFC_DO_RESET);
	do_reset_if_up = (ctx->ifc_flags & IFC_DO_RESET_IF_UP);
	do_watchdog = (ctx->ifc_flags & IFC_DO_WATCHDOG);
	in_detach = (ctx->ifc_flags & IFC_IN_DETACH);
	ctx->ifc_flags &= ~(IFC_DO_RESET | IFC_DO_RESET_IF_UP |
	    IFC_DO_WATCHDOG);
	STATE_UNLOCK(ctx);

	if ((!running && !oactive) && !(ctx->ifc_sctx->isc_flags & IFLIB_ADMIN_ALWAYS_RUN))
		return;
	if (in_detach)
		return;
	KFAIL_POINT_CODE_COND(_debug_fail_point_iflib,
	    admin_task_after_detach_check,
	    iflib_admin_task_fail_device[0] != '\0' &&
	    strcmp(device_get_nameunit(ctx->ifc_dev),
	    iflib_admin_task_fail_device) == 0, FAIL_POINT_NONSLEEPABLE, {});

	CTX_LOCK(ctx);
	if (ctx->ifc_pm_state != IFLIB_PM_ACTIVE) {
		CTX_UNLOCK(ctx);
		return;
	}
	if (!do_reset && do_reset_if_up &&
	    (if_getflags(ctx->ifc_ifp) & IFF_UP) != 0)
		do_reset = true;
	for (txq = ctx->ifc_txqs, i = 0; i < sctx->isc_ntxqsets; i++, txq++) {
		CALLOUT_LOCK(txq);
		callout_stop(&txq->ift_timer);
		CALLOUT_UNLOCK(txq);
	}
	if (ctx->ifc_sctx->isc_flags & IFLIB_HAS_ADMINCQ)
		IFDI_ADMIN_COMPLETION_HANDLE(ctx);
	if (do_watchdog) {
		ctx->ifc_tx_watchdog_events++;
		IFDI_WATCHDOG_RESET(ctx);
	}
	IFDI_UPDATE_ADMIN_STATUS(ctx);
	for (txq = ctx->ifc_txqs, i = 0; i < sctx->isc_ntxqsets; i++, txq++) {
		callout_reset_on(&txq->ift_timer, iflib_timer_default, iflib_timer, txq,
		    txq->ift_timer.c_cpu);
	}
	IFDI_LINK_INTR_ENABLE(ctx);
	if (do_reset)
		iflib_if_init_locked(ctx);
	CTX_UNLOCK(ctx);

	if (LINK_ACTIVE(ctx) == 0)
		return;
	for (txq = ctx->ifc_txqs, i = 0; i < sctx->isc_ntxqsets; i++, txq++)
		iflib_txq_check_drain(txq, IFLIB_RESTART_BUDGET);
}

static void
_task_fn_iov(void *context, int pending)
{
	if_ctx_t ctx = context;

	if (iflib_in_detach(ctx))
		return;
	if (!(if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING) &&
	    !(ctx->ifc_sctx->isc_flags & IFLIB_ADMIN_ALWAYS_RUN))
		return;

	CTX_LOCK(ctx);
	if (ctx->ifc_pm_state != IFLIB_PM_ACTIVE) {
		CTX_UNLOCK(ctx);
		return;
	}
	IFDI_VFLR_HANDLE(ctx);
	CTX_UNLOCK(ctx);
}

static int
iflib_sysctl_int_delay(SYSCTL_HANDLER_ARGS)
{
	int err;
	if_int_delay_info_t info;
	if_ctx_t ctx;

	info = (if_int_delay_info_t)arg1;
	ctx = info->iidi_ctx;
	info->iidi_req = req;
	info->iidi_oidp = oidp;
	CTX_LOCK(ctx);
	err = IFDI_SYSCTL_INT_DELAY(ctx, info);
	CTX_UNLOCK(ctx);
	return (err);
}

/*********************************************************************
 *
 *  IFNET FUNCTIONS
 *
 **********************************************************************/

static void
iflib_if_init_locked(if_ctx_t ctx)
{
	if (ctx->ifc_pm_state != IFLIB_PM_ACTIVE)
		return;
	if (ctx->ifc_datapath_state != IFLIB_DP_STOPPED)
		iflib_stop(ctx);
	iflib_init_locked(ctx);
}

static void
iflib_if_init(void *arg)
{
	if_ctx_t ctx = arg;

	CTX_LOCK(ctx);
	iflib_if_init_locked(ctx);
	CTX_UNLOCK(ctx);
}

static int
iflib_if_transmit(if_t ifp, struct mbuf *m)
{
	if_ctx_t ctx = if_getsoftc(ifp);
	iflib_txq_t txq;
	int err, qidx;
	int abdicate;

	if (__predict_false((if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0 || !LINK_ACTIVE(ctx))) {
		DBG_COUNTER_INC(tx_frees);
		m_freem(m);
		return (ENETDOWN);
	}

	MPASS(m->m_nextpkt == NULL);
	/* ALTQ-enabled interfaces always use queue 0. */
	qidx = 0;
	/* Use driver-supplied queue selection method if it exists */
	if (ctx->isc_txq_select_v2) {
		struct if_pkt_info pi;
		uint64_t early_pullups = 0;
		memset(&pi, 0, sizeof(pi));

		err = iflib_parse_header_partial(&pi, &m, &early_pullups);
		if (__predict_false(err != 0)) {
			/* Assign pullups for bad pkts to default queue */
			ctx->ifc_txqs[0].ift_pullups += early_pullups;
			DBG_COUNTER_INC(encap_txd_encap_fail);
			return (err);
		}
		/* Let driver make queueing decision */
		qidx = ctx->isc_txq_select_v2(ctx->ifc_softc, m, &pi);
		ctx->ifc_txqs[qidx].ift_pullups += early_pullups;
	}
	/* Backwards compatibility w/ simpler queue select */
	else if (ctx->isc_txq_select)
		qidx = ctx->isc_txq_select(ctx->ifc_softc, m);
	/* If not, use iflib's standard method */
	else if ((NTXQSETS(ctx) > 1) && M_HASHTYPE_GET(m) && !if_altq_is_enabled(ifp))
		qidx = QIDX(ctx, m);

	/* Set TX queue */
	txq = &ctx->ifc_txqs[qidx];

#ifdef DRIVER_BACKPRESSURE
	if (txq->ift_closed) {
		while (m != NULL) {
			next = m->m_nextpkt;
			m->m_nextpkt = NULL;
			m_freem(m);
			DBG_COUNTER_INC(tx_frees);
			m = next;
		}
		return (ENOBUFS);
	}
#endif
#ifdef notyet
	qidx = count = 0;
	mp = marr;
	next = m;
	do {
		count++;
		next = next->m_nextpkt;
	} while (next != NULL);

	if (count > nitems(marr))
		if ((mp = malloc(count * sizeof(struct mbuf *), M_IFLIB, M_NOWAIT)) == NULL) {
			/* XXX check nextpkt */
			m_freem(m);
			/* XXX simplify for now */
			DBG_COUNTER_INC(tx_frees);
			return (ENOBUFS);
		}
	for (next = m, i = 0; next != NULL; i++) {
		mp[i] = next;
		next = next->m_nextpkt;
		mp[i]->m_nextpkt = NULL;
	}
#endif
	DBG_COUNTER_INC(tx_seen);
	abdicate = ctx->ifc_sysctl_tx_abdicate;

	err = ifmp_ring_enqueue(txq->ift_br, (void **)&m, 1, TX_BATCH_SIZE, abdicate);

	if (abdicate)
		GROUPTASK_ENQUEUE(&txq->ift_task);
	if (err) {
		if (!abdicate)
			GROUPTASK_ENQUEUE(&txq->ift_task);
		/* support forthcoming later */
#ifdef DRIVER_BACKPRESSURE
		txq->ift_closed = TRUE;
#endif
		ifmp_ring_check_drainage(txq->ift_br, TX_BATCH_SIZE);
		m_freem(m);
		DBG_COUNTER_INC(tx_frees);
		if (err == ENOBUFS)
			if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
		else
			if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
	}

	return (err);
}

#ifdef ALTQ
/*
 * The overall approach to integrating iflib with ALTQ is to continue to use
 * the iflib mp_ring machinery between the ALTQ queue(s) and the hardware
 * ring.  Technically, when using ALTQ, queueing to an intermediate mp_ring
 * is redundant/unnecessary, but doing so minimizes the amount of
 * ALTQ-specific code required in iflib.  It is assumed that the overhead of
 * redundantly queueing to an intermediate mp_ring is swamped by the
 * performance limitations inherent in using ALTQ.
 *
 * When ALTQ support is compiled in, all iflib drivers will use a transmit
 * routine, iflib_altq_if_transmit(), that checks if ALTQ is enabled for the
 * given interface.  If ALTQ is enabled for an interface, then all
 * transmitted packets for that interface will be submitted to the ALTQ
 * subsystem via IFQ_ENQUEUE().  We don't use the legacy if_transmit()
 * implementation because it uses IFQ_HANDOFF(), which will duplicatively
 * update stats that the iflib machinery handles, and which is sensitve to
 * the disused IFF_DRV_OACTIVE flag.  Additionally, iflib_altq_if_start()
 * will be installed as the start routine for use by ALTQ facilities that
 * need to trigger queue drains on a scheduled basis.
 *
 */
static void
iflib_altq_if_start(if_t ifp)
{
	struct ifaltq *ifq = &ifp->if_snd; /* XXX - DRVAPI */
	struct mbuf *m;

	IFQ_LOCK(ifq);
	IFQ_DEQUEUE_NOLOCK(ifq, m);
	while (m != NULL) {
		iflib_if_transmit(ifp, m);
		IFQ_DEQUEUE_NOLOCK(ifq, m);
	}
	IFQ_UNLOCK(ifq);
}

static int
iflib_altq_if_transmit(if_t ifp, struct mbuf *m)
{
	if_ctx_t ctx = if_getsoftc(ifp);
	int err;

	if (if_altq_is_enabled(ifp)) {
		IFQ_ENQUEUE(&ifp->if_snd, m, err); /* XXX - DRVAPI */
		if (err == 0)
			if_start(ifp);
		return (err);
	}
	if (ctx->ifc_sysctl_simple_tx)
		err = iflib_simple_transmit(ifp, m);
	else
		err = iflib_if_transmit(ifp, m);

	return (err);
}
#endif /* ALTQ */

static void
iflib_if_qflush(if_t ifp)
{
	if_ctx_t ctx = if_getsoftc(ifp);
	iflib_txq_t txq = ctx->ifc_txqs;
	int i;

	STATE_LOCK(ctx);
	ctx->ifc_flags |= IFC_QFLUSH;
	STATE_UNLOCK(ctx);
	for (i = 0; i < NTXQSETS(ctx); i++, txq++) {
		if (txq->ift_drbr != NULL) {
			mtx_lock(&txq->ift_mtx);
			drbr_flush(ifp, txq->ift_drbr);
			mtx_unlock(&txq->ift_mtx);
			continue;
		}
		while (!(ifmp_ring_is_idle(txq->ift_br) || ifmp_ring_is_stalled(txq->ift_br)))
			iflib_txq_check_drain(txq, 0);
	}
	STATE_LOCK(ctx);
	ctx->ifc_flags &= ~IFC_QFLUSH;
	STATE_UNLOCK(ctx);

	/*
	 * When ALTQ is enabled, this will also take care of purging the
	 * ALTQ queue(s).
	 */
	if_qflush(ifp);
}

#define IFCAP_FLAGS (IFCAP_HWCSUM_IPV6 | IFCAP_HWCSUM | IFCAP_LRO | \
		    IFCAP_TSO | IFCAP_VLAN_HWTAGGING | IFCAP_HWSTATS | \
		    IFCAP_VLAN_MTU | IFCAP_VLAN_HWFILTER | \
		    IFCAP_VLAN_HWTSO | IFCAP_VLAN_HWCSUM | IFCAP_MEXTPG)

static int
iflib_if_ioctl(if_t ifp, u_long command, caddr_t data)
{
	if_ctx_t ctx = if_getsoftc(ifp);
	struct ifreq	*ifr = (struct ifreq *)data;
#if defined(INET) || defined(INET6)
	struct ifaddr	*ifa = (struct ifaddr *)data;
#endif
	bool		avoid_reset = false, restart;
	int		err = 0, reinit = 0;

	switch (command) {
	case SIOCSIFADDR:
#ifdef INET
		if (ifa->ifa_addr->sa_family == AF_INET)
			avoid_reset = true;
#endif
#ifdef INET6
		if (ifa->ifa_addr->sa_family == AF_INET6)
			avoid_reset = true;
#endif
		/*
		 * Calling init results in link renegotiation,
		 * so we avoid doing it when possible.
		 */
		if (avoid_reset) {
			if_setflagbits(ifp, IFF_UP, 0);
			if (!(if_getdrvflags(ifp) & IFF_DRV_RUNNING))
				reinit = 1;
#ifdef INET
			if (!(if_getflags(ifp) & IFF_NOARP))
				arp_ifinit(ifp, ifa);
#endif
		} else
			err = ether_ioctl(ifp, command, data);
		break;
	case SIOCSIFMTU:
		CTX_LOCK(ctx);
		if (ifr->ifr_mtu == if_getmtu(ifp)) {
			CTX_UNLOCK(ctx);
			break;
		}
		restart = ctx->ifc_datapath_state == IFLIB_DP_RUNNING ||
		    (if_getflags(ifp) & IFF_UP) != 0;
		/* Quiesce a datapath whose stopped state is not established. */
		if (ctx->ifc_datapath_state != IFLIB_DP_STOPPED)
			iflib_stop(ctx);

		if ((err = IFDI_MTU_SET(ctx, ifr->ifr_mtu)) == 0) {
			STATE_LOCK(ctx);
			if (ifr->ifr_mtu > ctx->ifc_max_fl_buf_size)
				ctx->ifc_flags |= IFC_MULTISEG;
			else
				ctx->ifc_flags &= ~IFC_MULTISEG;
			STATE_UNLOCK(ctx);
			err = if_setmtu(ifp, ifr->ifr_mtu);
		}
		if (restart)
			iflib_init_locked(ctx);
		CTX_UNLOCK(ctx);
		break;
	case SIOCSIFFLAGS:
		CTX_LOCK(ctx);
		if (if_getflags(ifp) & IFF_UP) {
			if (if_getdrvflags(ifp) & IFF_DRV_RUNNING) {
				if ((if_getflags(ifp) ^ ctx->ifc_if_flags) &
				    (IFF_PROMISC | IFF_ALLMULTI)) {
					CTX_UNLOCK(ctx);
					err = IFDI_PROMISC_SET(ctx, if_getflags(ifp));
					CTX_LOCK(ctx);
				}
			} else
				reinit = 1;
		} else if (ctx->ifc_datapath_state != IFLIB_DP_STOPPED) {
			/* Stop partially initialized hardware as well as running queues. */
			iflib_stop(ctx);
		}
		ctx->ifc_if_flags = if_getflags(ifp);
		CTX_UNLOCK(ctx);
		break;
	case SIOCADDMULTI:
	case SIOCDELMULTI:
		if (if_getdrvflags(ifp) & IFF_DRV_RUNNING) {
			CTX_LOCK(ctx);
			IFDI_INTR_DISABLE(ctx);
			IFDI_MULTI_SET(ctx);
			IFDI_INTR_ENABLE(ctx);
			CTX_UNLOCK(ctx);
		}
		break;
	case SIOCSIFMEDIA:
		CTX_LOCK(ctx);
		IFDI_MEDIA_SET(ctx);
		CTX_UNLOCK(ctx);
		/* FALLTHROUGH */
	case SIOCGIFMEDIA:
	case SIOCGIFXMEDIA:
		err = ifmedia_ioctl(ifp, ifr, ctx->ifc_mediap, command);
		break;
	case SIOCGI2C:
		/* FALLTHROUGH */
	case SIOCGI2CPB:
	{
		struct ifi2creq i2c;
		if_shared_ctx_t sctx = ctx->ifc_sctx;

		err = copyin(ifr_data_get_ptr(ifr), &i2c, sizeof(i2c));
		if (err != 0)
			break;
		if (i2c.dev_addr != 0xA0 && i2c.dev_addr != 0xA2) {
			err = EINVAL;
			break;
		}
		if (i2c.len > sizeof(i2c.data)) {
			err = EINVAL;
			break;
		}
		if (command == SIOCGI2C) {
			i2c.page = i2c.bank = 0;
		} else if ((sctx->isc_flags & IFLIB_I2C_PAGE_BANK) == 0) {
			err = EINVAL;
			break;
		}

		if ((err = IFDI_I2C_REQ(ctx, &i2c)) == 0)
			err = copyout(&i2c, ifr_data_get_ptr(ifr),
			    sizeof(i2c));
		break;
	}
	case SIOCSIFCAP:
	{
		int mask, setmask, oldmask;

		oldmask = if_getcapenable(ifp);
		mask = ifr->ifr_reqcap ^ oldmask;
		mask &= ctx->ifc_softc_ctx.isc_capabilities | IFCAP_MEXTPG;
		setmask = 0;
#ifdef TCP_OFFLOAD
		setmask |= mask & (IFCAP_TOE4 | IFCAP_TOE6);
#endif
		setmask |= (mask & IFCAP_FLAGS);
		setmask |= (mask & IFCAP_WOL);

		/*
		 * If any RX csum has changed, change all the ones that
		 * are supported by the driver.
		 */
		if (setmask & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6)) {
			setmask |= ctx->ifc_softc_ctx.isc_capabilities &
			    (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6);
		}

		/*
		 * want to ensure that traffic has stopped before we change any of the flags
		 */
		if (setmask) {
			CTX_LOCK(ctx);
			restart = (setmask & ~IFCAP_WOL) != 0 &&
			    (ctx->ifc_datapath_state == IFLIB_DP_RUNNING ||
			    (if_getflags(ifp) & IFF_UP) != 0);
			if (restart)
				iflib_stop(ctx);
			STATE_LOCK(ctx);
			if_togglecapenable(ifp, setmask);
			ctx->ifc_softc_ctx.isc_capenable ^= setmask;
			STATE_UNLOCK(ctx);
			if (restart)
				iflib_init_locked(ctx);
			CTX_UNLOCK(ctx);
		}
		if_vlancap(ifp);
		break;
	}
	case SIOCGPRIVATE_0:
	case SIOCSDRVSPEC:
	case SIOCGDRVSPEC:
		CTX_LOCK(ctx);
		err = IFDI_PRIV_IOCTL(ctx, command, data);
		CTX_UNLOCK(ctx);
		break;
	case SIOCGIFDOWNREASON:
		CTX_LOCK(ctx);
		err = IFDI_GET_DOWNREASON(ctx, (struct ifdownreason *)data);
		CTX_UNLOCK(ctx);
		break;
	default:
		err = ether_ioctl(ifp, command, data);
		break;
	}
	if (reinit)
		iflib_if_init(ctx);
	return (err);
}

static int
iflib_if_vf_status(if_t ifp, struct if_vf_status **statusp)
{
	if_ctx_t ctx;
	int error;

	ctx = if_getsoftc(ifp);
	CTX_LOCK(ctx);
	error = IFDI_VF_STATUS(ctx, statusp);
	CTX_UNLOCK(ctx);
	return (error);
}

static uint64_t
iflib_if_get_counter(if_t ifp, ift_counter cnt)
{
	if_ctx_t ctx = if_getsoftc(ifp);

	return (IFDI_GET_COUNTER(ctx, cnt));
}

/*********************************************************************
 *
 *  OTHER FUNCTIONS EXPORTED TO THE STACK
 *
 **********************************************************************/

static void
iflib_vlan_register(void *arg, if_t ifp, uint16_t vtag)
{
	if_ctx_t ctx = if_getsoftc(ifp);
	bool restart;

	if ((void *)ctx != arg)
		return;

	if ((vtag == 0) || (vtag > 4095))
		return;

	if (iflib_in_detach(ctx))
		return;

	CTX_LOCK(ctx);
	restart = IFDI_NEEDS_RESTART(ctx, IFLIB_RESTART_VLAN_CONFIG) &&
	    ((if_getflags(ifp) & IFF_UP) != 0 ||
	    ctx->ifc_datapath_state == IFLIB_DP_RUNNING);
	/* Driver may need all untagged packets to be flushed */
	if (restart)
		iflib_stop(ctx);
	IFDI_VLAN_REGISTER(ctx, vtag);
	/* Re-init to load the changes, if required */
	if (restart)
		iflib_init_locked(ctx);
	CTX_UNLOCK(ctx);
}

static void
iflib_vlan_unregister(void *arg, if_t ifp, uint16_t vtag)
{
	if_ctx_t ctx = if_getsoftc(ifp);
	bool restart;

	if ((void *)ctx != arg)
		return;

	if ((vtag == 0) || (vtag > 4095))
		return;

	CTX_LOCK(ctx);
	restart = IFDI_NEEDS_RESTART(ctx, IFLIB_RESTART_VLAN_CONFIG) &&
	    ((if_getflags(ifp) & IFF_UP) != 0 ||
	    ctx->ifc_datapath_state == IFLIB_DP_RUNNING);
	/* Driver may need all tagged packets to be flushed */
	if (restart)
		iflib_stop(ctx);
	IFDI_VLAN_UNREGISTER(ctx, vtag);
	/* Re-init to load the changes, if required */
	if (restart)
		iflib_init_locked(ctx);
	CTX_UNLOCK(ctx);
}

static void
_task_fn_led(void *context, int pending __unused)
{
	if_ctx_t ctx = context;
	bool in_detach;
	int onoff;

	STATE_LOCK(ctx);
	in_detach = (ctx->ifc_flags & IFC_IN_DETACH) != 0;
	onoff = ctx->ifc_led_state;
	STATE_UNLOCK(ctx);
	if (in_detach)
		return;

	CTX_LOCK(ctx);
	if (ctx->ifc_pm_state == IFLIB_PM_ACTIVE)
		IFDI_LED_FUNC(ctx, onoff);
	CTX_UNLOCK(ctx);
}

static void
iflib_led_func(void *arg, int onoff)
{
	if_ctx_t ctx = arg;
	bool in_detach;

	/* led(4) may invoke this callback from a non-sleepable callout. */
	STATE_LOCK(ctx);
	ctx->ifc_led_state = onoff;
	in_detach = (ctx->ifc_flags & IFC_IN_DETACH) != 0;
	STATE_UNLOCK(ctx);
	if (!in_detach)
		taskqueue_enqueue(ctx->ifc_tq, &ctx->ifc_led_task);
}

/*********************************************************************
 *
 *  BUS FUNCTION DEFINITIONS
 *
 **********************************************************************/

int
iflib_device_probe(device_t dev)
{
	const pci_vendor_info_t *ent;
	if_shared_ctx_t sctx;
	uint16_t pci_device_id, pci_rev_id, pci_subdevice_id, pci_subvendor_id;
	uint16_t pci_vendor_id;

	if ((sctx = DEVICE_REGISTER(dev)) == NULL || sctx->isc_magic != IFLIB_MAGIC)
		return (ENOTSUP);

	pci_vendor_id = pci_get_vendor(dev);
	pci_device_id = pci_get_device(dev);
	pci_subvendor_id = pci_get_subvendor(dev);
	pci_subdevice_id = pci_get_subdevice(dev);
	pci_rev_id = pci_get_revid(dev);
	if (sctx->isc_parse_devinfo != NULL)
		sctx->isc_parse_devinfo(&pci_device_id, &pci_subvendor_id, &pci_subdevice_id, &pci_rev_id);

	ent = sctx->isc_vendor_info;
	while (ent->pvi_vendor_id != 0) {
		if (pci_vendor_id != ent->pvi_vendor_id) {
			ent++;
			continue;
		}
		if ((pci_device_id == ent->pvi_device_id) &&
		    ((pci_subvendor_id == ent->pvi_subvendor_id) ||
		     (ent->pvi_subvendor_id == 0)) &&
		    ((pci_subdevice_id == ent->pvi_subdevice_id) ||
		     (ent->pvi_subdevice_id == 0)) &&
		    ((pci_rev_id == ent->pvi_rev_id) ||
		     (ent->pvi_rev_id == 0))) {
			device_set_desc_copy(dev, ent->pvi_name);
			/* this needs to be changed to zero if the bus probing code
			 * ever stops re-probing on best match because the sctx
			 * may have its values over written by register calls
			 * in subsequent probes
			 */
			return (BUS_PROBE_DEFAULT);
		}
		ent++;
	}
	return (ENXIO);
}

int
iflib_device_probe_vendor(device_t dev)
{
	int probe;

	probe = iflib_device_probe(dev);
	if (probe == BUS_PROBE_DEFAULT)
		return (BUS_PROBE_VENDOR);
	else
		return (probe);
}

static void
iflib_reset_qvalues(if_ctx_t ctx)
{
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	device_t dev = ctx->ifc_dev;
	int i;

	if (ctx->ifc_sysctl_ntxqs != 0)
		scctx->isc_ntxqsets = ctx->ifc_sysctl_ntxqs;
	if (ctx->ifc_sysctl_nrxqs != 0)
		scctx->isc_nrxqsets = ctx->ifc_sysctl_nrxqs;

	for (i = 0; i < sctx->isc_ntxqs; i++) {
		if (ctx->ifc_sysctl_ntxds[i] != 0)
			scctx->isc_ntxd[i] = ctx->ifc_sysctl_ntxds[i];
		else
			scctx->isc_ntxd[i] = sctx->isc_ntxd_default[i];
	}

	for (i = 0; i < sctx->isc_nrxqs; i++) {
		if (ctx->ifc_sysctl_nrxds[i] != 0)
			scctx->isc_nrxd[i] = ctx->ifc_sysctl_nrxds[i];
		else
			scctx->isc_nrxd[i] = sctx->isc_nrxd_default[i];
	}

	for (i = 0; i < sctx->isc_nrxqs; i++) {
		if (scctx->isc_nrxd[i] < sctx->isc_nrxd_min[i]) {
			device_printf(dev, "nrxd%d: %d less than nrxd_min %d - resetting to min\n",
			    i, scctx->isc_nrxd[i], sctx->isc_nrxd_min[i]);
			scctx->isc_nrxd[i] = sctx->isc_nrxd_min[i];
		}
		if (scctx->isc_nrxd[i] > sctx->isc_nrxd_max[i]) {
			device_printf(dev, "nrxd%d: %d greater than nrxd_max %d - resetting to max\n",
			    i, scctx->isc_nrxd[i], sctx->isc_nrxd_max[i]);
			scctx->isc_nrxd[i] = sctx->isc_nrxd_max[i];
		}
		if (!powerof2(scctx->isc_nrxd[i])) {
			device_printf(dev, "nrxd%d: %d is not a power of 2 - using default value of %d\n",
			    i, scctx->isc_nrxd[i], sctx->isc_nrxd_default[i]);
			scctx->isc_nrxd[i] = sctx->isc_nrxd_default[i];
		}
	}

	for (i = 0; i < sctx->isc_ntxqs; i++) {
		if (scctx->isc_ntxd[i] < sctx->isc_ntxd_min[i]) {
			device_printf(dev, "ntxd%d: %d less than ntxd_min %d - resetting to min\n",
			    i, scctx->isc_ntxd[i], sctx->isc_ntxd_min[i]);
			scctx->isc_ntxd[i] = sctx->isc_ntxd_min[i];
		}
		if (scctx->isc_ntxd[i] > sctx->isc_ntxd_max[i]) {
			device_printf(dev, "ntxd%d: %d greater than ntxd_max %d - resetting to max\n",
			    i, scctx->isc_ntxd[i], sctx->isc_ntxd_max[i]);
			scctx->isc_ntxd[i] = sctx->isc_ntxd_max[i];
		}
		if (!powerof2(scctx->isc_ntxd[i])) {
			device_printf(dev, "ntxd%d: %d is not a power of 2 - using default value of %d\n",
			    i, scctx->isc_ntxd[i], sctx->isc_ntxd_default[i]);
			scctx->isc_ntxd[i] = sctx->isc_ntxd_default[i];
		}
	}
	scctx->isc_tx_pad = 2;
}

static void
iflib_add_pfil(if_ctx_t ctx)
{
	struct pfil_head *pfil;
	struct pfil_head_args pa;
	iflib_rxq_t rxq;
	int i;

	pa.pa_version = PFIL_VERSION;
	pa.pa_flags = PFIL_IN;
	pa.pa_type = PFIL_TYPE_ETHERNET;
	pa.pa_headname = if_name(ctx->ifc_ifp);
	pfil = pfil_head_register(&pa);

	for (i = 0, rxq = ctx->ifc_rxqs; i < NRXQSETS(ctx); i++, rxq++) {
		rxq->pfil = pfil;
	}
}

static void
iflib_rem_pfil(if_ctx_t ctx)
{
	struct pfil_head *pfil;
	iflib_rxq_t rxq;
	int i;

	rxq = ctx->ifc_rxqs;
	pfil = rxq->pfil;
	for (i = 0; i < NRXQSETS(ctx); i++, rxq++) {
		rxq->pfil = NULL;
	}
	pfil_head_unregister(pfil);
}


/*
 * Advance forward by n members of the cpuset ctx->ifc_cpus starting from
 * cpuid and wrapping as necessary.
 */
static unsigned int
cpuid_advance(if_ctx_t ctx, unsigned int cpuid, unsigned int n)
{
	unsigned int first_valid;
	unsigned int last_valid;

	/* cpuid should always be in the valid set */
	MPASS(CPU_ISSET(cpuid, &ctx->ifc_cpus));

	/* valid set should never be empty */
	MPASS(!CPU_EMPTY(&ctx->ifc_cpus));

	first_valid = CPU_FFS(&ctx->ifc_cpus) - 1;
	last_valid = CPU_FLS(&ctx->ifc_cpus) - 1;
	n = n % CPU_COUNT(&ctx->ifc_cpus);
	while (n > 0) {
		do {
			cpuid++;
			if (cpuid > last_valid)
				cpuid = first_valid;
		} while (!CPU_ISSET(cpuid, &ctx->ifc_cpus));
		n--;
	}

	return (cpuid);
}

/*
 * CPU mapping behaviors
 * ---------------------
 * 'separate txrx' refers to the separate_txrx sysctl
 * 'use logical' refers to the use_logical_cores sysctl
 * 'INTR CPUS' indicates whether bus_get_cpus(INTR_CPUS) succeeded
 *
 *  separate     use     INTR
 *    txrx     logical   CPUS   result
 * ---------- --------- ------ ------------------------------------------------
 *     -          -       X     RX and TX queues mapped to consecutive physical
 *                              cores with RX/TX pairs on same core and excess
 *                              of either following
 *     -          X       X     RX and TX queues mapped to consecutive cores
 *                              of any type with RX/TX pairs on same core and
 *                              excess of either following
 *     X          -       X     RX and TX queues mapped to consecutive physical
 *                              cores; all RX then all TX
 *     X          X       X     RX queues mapped to consecutive physical cores
 *                              first, then TX queues mapped to L2 neighbor of
 *                              the corresponding RX queue if one exists,
 *                              otherwise to consecutive physical cores
 *     -         n/a      -     RX and TX queues mapped to consecutive cores of
 *                              any type with RX/TX pairs on same core and excess
 *                              of either following
 *     X         n/a      -     RX and TX queues mapped to consecutive cores of
 *                              any type; all RX then all TX
 */
static unsigned int
get_cpuid_for_queue(if_ctx_t ctx, unsigned int base_cpuid, unsigned int qid,
    bool is_tx)
{
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	unsigned int core_index;

	if (ctx->ifc_sysctl_separate_txrx) {
		/*
		 * When using separate CPUs for TX and RX, the assignment
		 * will always be of a consecutive CPU out of the set of
		 * context CPUs, except for the specific case where the
		 * context CPUs are phsyical cores, the use of logical cores
		 * has been enabled, the assignment is for TX, the TX qid
		 * corresponds to an RX qid, and the CPU assigned to the
		 * corresponding RX queue has an L2 neighbor.
		 */
		if (ctx->ifc_sysctl_use_logical_cores &&
		    ctx->ifc_cpus_are_physical_cores &&
		    is_tx && qid < scctx->isc_nrxqsets) {
			int l2_neighbor;
			unsigned int rx_cpuid;

			rx_cpuid = cpuid_advance(ctx, base_cpuid, qid);
			l2_neighbor = sched_find_l2_neighbor(rx_cpuid);
			if (l2_neighbor != -1) {
				return (l2_neighbor);
			}
			/*
			 * ... else fall through to the normal
			 * consecutive-after-RX assignment scheme.
			 *
			 * Note that we are assuming that all RX queue CPUs
			 * have an L2 neighbor, or all do not.  If a mixed
			 * scenario is possible, we will have to keep track
			 * separately of how many queues prior to this one
			 * were not able to be assigned to an L2 neighbor.
			 */
		}
		if (is_tx)
			core_index = scctx->isc_nrxqsets + qid;
		else
			core_index = qid;
	} else {
		core_index = qid;
	}

	return (cpuid_advance(ctx, base_cpuid, core_index));
}

static uint16_t
get_ctx_core_offset(if_ctx_t ctx)
{
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	struct cpu_offset *op;
	cpuset_t assigned_cpus;
	unsigned int cores_consumed;
	unsigned int base_cpuid = ctx->ifc_sysctl_core_offset;
	unsigned int first_valid;
	unsigned int last_valid;
	unsigned int i;

	MPASS(!ctx->ifc_core_offset_ref);
	first_valid = CPU_FFS(&ctx->ifc_cpus) - 1;
	last_valid = CPU_FLS(&ctx->ifc_cpus) - 1;

	if (base_cpuid != CORE_OFFSET_UNSPECIFIED) {
		/*
		 * Align the user-chosen base CPU ID to the next valid CPU
		 * for this device.  If the chosen base CPU ID is smaller
		 * than the first valid CPU or larger than the last valid
		 * CPU, we assume the user does not know what the valid
		 * range is for this device and is thinking in terms of a
		 * zero-based reference frame, and so we shift the given
		 * value into the valid range (and wrap accordingly) so the
		 * intent is translated to the proper frame of reference.
		 * If the base CPU ID is within the valid first/last, but
		 * does not correspond to a valid CPU, it is advanced to the
		 * next valid CPU (wrapping if necessary).
		 */
		if (base_cpuid < first_valid || base_cpuid > last_valid) {
			/* shift from zero-based to first_valid-based */
			base_cpuid += first_valid;
			/* wrap to range [first_valid, last_valid] */
			base_cpuid = (base_cpuid - first_valid) %
			    (last_valid - first_valid + 1);
		}
		if (!CPU_ISSET(base_cpuid, &ctx->ifc_cpus)) {
			/*
			 * base_cpuid is in [first_valid, last_valid], but
			 * not a member of the valid set.  In this case,
			 * there will always be a member of the valid set
			 * with a CPU ID that is greater than base_cpuid,
			 * and we simply advance to it.
			 */
			while (!CPU_ISSET(base_cpuid, &ctx->ifc_cpus))
				base_cpuid++;
		}
		return (base_cpuid);
	}

	/*
	 * Determine how many cores will be consumed by performing the CPU
	 * assignments and counting how many of the assigned CPUs correspond
	 * to CPUs in the set of context CPUs.  This is done using the CPU
	 * ID first_valid as the base CPU ID, as the base CPU must be within
	 * the set of context CPUs.
	 *
	 * Note not all assigned CPUs will be in the set of context CPUs
	 * when separate CPUs are being allocated to TX and RX queues,
	 * assignment to logical cores has been enabled, the set of context
	 * CPUs contains only physical CPUs, and TX queues are mapped to L2
	 * neighbors of CPUs that RX queues have been mapped to - in this
	 * case we do only want to count how many CPUs in the set of context
	 * CPUs have been consumed, as that determines the next CPU in that
	 * set to start allocating at for the next device for which
	 * core_offset is not set.
	 */
	CPU_ZERO(&assigned_cpus);
	for (i = 0; i < scctx->isc_ntxqsets; i++)
		CPU_SET(get_cpuid_for_queue(ctx, first_valid, i, true),
		    &assigned_cpus);
	for (i = 0; i < scctx->isc_nrxqsets; i++)
		CPU_SET(get_cpuid_for_queue(ctx, first_valid, i, false),
		    &assigned_cpus);
	CPU_AND(&assigned_cpus, &assigned_cpus, &ctx->ifc_cpus);
	cores_consumed = CPU_COUNT(&assigned_cpus);

	mtx_lock(&cpu_offset_mtx);
	SLIST_FOREACH(op, &cpu_offsets, entries) {
		if (CPU_CMP(&ctx->ifc_cpus, &op->set) == 0) {
			base_cpuid = op->next_cpuid;
			op->next_cpuid = cpuid_advance(ctx, op->next_cpuid,
			    cores_consumed);
			MPASS(op->refcount < UINT_MAX);
			op->refcount++;
			ctx->ifc_core_offset_ref = true;
			break;
		}
	}
	if (base_cpuid == CORE_OFFSET_UNSPECIFIED) {
		base_cpuid = first_valid;
		op = malloc(sizeof(struct cpu_offset), M_IFLIB,
		    M_NOWAIT | M_ZERO);
		if (op == NULL) {
			device_printf(ctx->ifc_dev,
			    "allocation for cpu offset failed.\n");
		} else {
			op->next_cpuid = cpuid_advance(ctx, base_cpuid,
			    cores_consumed);
			op->refcount = 1;
			CPU_COPY(&ctx->ifc_cpus, &op->set);
			SLIST_INSERT_HEAD(&cpu_offsets, op, entries);
			ctx->ifc_core_offset_ref = true;
		}
	}
	mtx_unlock(&cpu_offset_mtx);

	return (base_cpuid);
}

static void
unref_ctx_core_offset(if_ctx_t ctx)
{
	struct cpu_offset *op, *top;

	if (!ctx->ifc_core_offset_ref)
		return;

	mtx_lock(&cpu_offset_mtx);
	SLIST_FOREACH_SAFE(op, &cpu_offsets, entries, top) {
		if (CPU_CMP(&ctx->ifc_cpus, &op->set) == 0) {
			MPASS(op->refcount > 0);
			op->refcount--;
			if (op->refcount == 0) {
				SLIST_REMOVE(&cpu_offsets, op, cpu_offset, entries);
				free(op, M_IFLIB);
			}
			ctx->ifc_core_offset_ref = false;
			break;
		}
	}
	mtx_unlock(&cpu_offset_mtx);
	MPASS(!ctx->ifc_core_offset_ref);
}

static bool
iflib_register_fail_device_matches(device_t dev)
{
	const char *nameunit;

	nameunit = device_get_nameunit(dev);
	return (iflib_register_fail_device[0] != '\0' && nameunit != NULL &&
	    strcmp(nameunit, iflib_register_fail_device) == 0);
}

#define	IFLIB_REGISTER_FAIL_POINT(_dev, _name, _error, _label) do { \
	KFAIL_POINT_CODE_COND(_debug_fail_point_iflib, _name, \
	    iflib_register_fail_device_matches((_dev)), \
	    FAIL_POINT_NONSLEEPABLE, { \
		(_error) = RETURN_VALUE; \
		if ((_error) <= 0) \
			(_error) = EIO; \
		device_printf((_dev), \
		    "injecting iflib registration failure at %s: %d\n", \
		    #_name, (_error)); \
		goto _label; \
	}); \
} while (0)

int
iflib_device_register(device_t dev, void *sc, if_shared_ctx_t sctx, if_ctx_t *ctxp)
{
	if_ctx_t ctx;
	if_t ifp;
	if_softc_ctx_t scctx;
	kobjop_desc_t kobj_desc;
	kobj_method_t *kobj_method;
	bool attach_pre_succeeded, intr_allocated, queues_allocated;
	int err, msix, rid;
#ifdef PCI_IOV
	int iov_error;
#endif
	int num_txd, num_rxd;
	char namebuf[TASKQUEUE_NAMELEN];

	attach_pre_succeeded = false;
	intr_allocated = false;
	queues_allocated = false;
	ctx = malloc(sizeof(*ctx), M_IFLIB, M_WAITOK | M_ZERO);
	ctx->ifc_datapath_state = IFLIB_DP_UNKNOWN;
	ctx->ifc_pm_state = IFLIB_PM_ACTIVE;

	if (sc == NULL) {
		sc = malloc(sctx->isc_driver->size, M_IFLIB, M_WAITOK | M_ZERO);
		device_set_softc(dev, ctx);
		ctx->ifc_flags |= IFC_SC_ALLOCATED;
	}

	ctx->ifc_sctx = sctx;
	ctx->ifc_dev = dev;
	ctx->ifc_softc = sc;

	iflib_register(ctx);
	iflib_add_device_sysctl_pre(ctx);

	scctx = &ctx->ifc_softc_ctx;
	ifp = ctx->ifc_ifp;
	if (ctx->ifc_sysctl_simple_tx) {
		/* if_start drives the same drbr drain when ALTQ is active. */
#ifndef ALTQ
		if_settransmitfn(ifp, iflib_simple_transmit);
#endif
		if_setstartfn(ifp, iflib_simple_if_start);
		device_printf(dev, "using simple transmit\n");
	}
	iflib_reset_qvalues(ctx);
	CTX_LOCK(ctx);
	IFLIB_REGISTER_FAIL_POINT(dev, register_before_attach_pre, err,
	    fail_cleanup);
	if ((err = IFDI_ATTACH_PRE(ctx)) != 0) {
		device_printf(dev, "IFDI_ATTACH_PRE failed %d\n", err);
		goto fail_cleanup;
	}
	attach_pre_succeeded = true;
	IFLIB_REGISTER_FAIL_POINT(dev, register_after_attach_pre, err,
	    fail_cleanup);
	_iflib_pre_assert(scctx);
	ctx->ifc_txrx = *scctx->isc_txrx;

	MPASS(scctx->isc_dma_width <= flsll(BUS_SPACE_MAXADDR));

	if (sctx->isc_flags & IFLIB_DRIVER_MEDIA)
		ctx->ifc_mediap = scctx->isc_media;

#ifdef INVARIANTS
	if (scctx->isc_capabilities & IFCAP_TXCSUM)
		MPASS(scctx->isc_tx_csum_flags);
#endif

	if_setcapabilities(ifp,
	    scctx->isc_capabilities | IFCAP_HWSTATS | IFCAP_MEXTPG);
	if_setcapenable(ifp,
	    scctx->isc_capenable | IFCAP_HWSTATS | IFCAP_MEXTPG);

	if (scctx->isc_ntxqsets == 0 || (scctx->isc_ntxqsets_max && scctx->isc_ntxqsets_max < scctx->isc_ntxqsets))
		scctx->isc_ntxqsets = scctx->isc_ntxqsets_max;
	if (scctx->isc_nrxqsets == 0 || (scctx->isc_nrxqsets_max && scctx->isc_nrxqsets_max < scctx->isc_nrxqsets))
		scctx->isc_nrxqsets = scctx->isc_nrxqsets_max;

	num_txd = iflib_num_tx_descs(ctx);
	num_rxd = iflib_num_rx_descs(ctx);

	/* XXX change for per-queue sizes */
	device_printf(dev, "Using %d TX descriptors and %d RX descriptors\n",
	    num_txd, num_rxd);

	if (scctx->isc_tx_nsegments > num_txd / MAX_SINGLE_PACKET_FRACTION)
		scctx->isc_tx_nsegments = max(1, num_txd /
		    MAX_SINGLE_PACKET_FRACTION);
	if (scctx->isc_tx_tso_segments_max > num_txd /
	    MAX_SINGLE_PACKET_FRACTION)
		scctx->isc_tx_tso_segments_max = max(1,
		    num_txd / MAX_SINGLE_PACKET_FRACTION);

	/* TSO parameters - dig these out of the data sheet - simply correspond to tag setup */
	if (if_getcapabilities(ifp) & IFCAP_TSO) {
		/*
		 * The stack can't handle a TSO size larger than IP_MAXPACKET,
		 * but some MACs do.
		 */
		if_sethwtsomax(ifp, min(scctx->isc_tx_tso_size_max,
		    IP_MAXPACKET));
		/*
		 * Take maximum number of m_pullup(9)'s in iflib_parse_header()
		 * into account.  In the worst case, each of these calls will
		 * add another mbuf and, thus, the requirement for another DMA
		 * segment.  So for best performance, it doesn't make sense to
		 * advertize a maximum of TSO segments that typically will
		 * require defragmentation in iflib_encap().
		 */
		if_sethwtsomaxsegcount(ifp, scctx->isc_tx_tso_segments_max - 3);
		if_sethwtsomaxsegsize(ifp, scctx->isc_tx_tso_segsize_max);
	}
	if (scctx->isc_rss_table_size == 0)
		scctx->isc_rss_table_size = 64;
	scctx->isc_rss_table_mask = scctx->isc_rss_table_size - 1;

	/* Create and start admin taskqueue */
	snprintf(namebuf, TASKQUEUE_NAMELEN, "if_%s_tq", device_get_nameunit(dev));
	ctx->ifc_tq = taskqueue_create_fast(namebuf, M_NOWAIT,
	    taskqueue_thread_enqueue, &ctx->ifc_tq);
	if (ctx->ifc_tq == NULL) {
		device_printf(dev, "Unable to create admin taskqueue\n");
		err = ENOMEM;
		goto fail_cleanup;
	}

	err = taskqueue_start_threads(&ctx->ifc_tq, 1, PI_NET, "%s", namebuf);
	if (err) {
		device_printf(dev,
		    "Unable to start admin taskqueue threads error: %d\n",
		    err);
		taskqueue_free(ctx->ifc_tq);
		ctx->ifc_tq = NULL;
		goto fail_cleanup;
	}

	TASK_INIT(&ctx->ifc_admin_task, 0, _task_fn_admin, ctx);
	TASK_INIT(&ctx->ifc_led_task, 0, _task_fn_led, ctx);
	TASK_INIT(&ctx->ifc_vflr_task, 0, _task_fn_iov, ctx);
	IFLIB_REGISTER_FAIL_POINT(dev, register_after_taskqueue, err,
	    fail_cleanup);

	/* Set up cpu set.  If it fails, use the set of all CPUs. */
	if (bus_get_cpus(dev, INTR_CPUS, sizeof(ctx->ifc_cpus), &ctx->ifc_cpus) != 0) {
		device_printf(dev, "Unable to fetch CPU list\n");
		CPU_COPY(&all_cpus, &ctx->ifc_cpus);
		ctx->ifc_cpus_are_physical_cores = false;
	} else
		ctx->ifc_cpus_are_physical_cores = true;
	MPASS(CPU_COUNT(&ctx->ifc_cpus) > 0);

	/*
	 * Now set up MSI or MSI-X, should return us the number of supported
	 * vectors (will be 1 for a legacy interrupt and MSI).
	 */
	if (sctx->isc_flags & IFLIB_SKIP_MSIX) {
		msix = scctx->isc_vectors;
	} else if (scctx->isc_msix_bar != 0)
		/*
		 * The simple fact that isc_msix_bar is not 0 does not mean we
		 * we have a good value there that is known to work.
		 */
		msix = iflib_msix_init(ctx);
	else {
		scctx->isc_vectors = 1;
		scctx->isc_ntxqsets = 1;
		scctx->isc_nrxqsets = 1;
		scctx->isc_intr = IFLIB_INTR_LEGACY;
		msix = 0;
	}
	intr_allocated = true;
	IFLIB_REGISTER_FAIL_POINT(dev, register_after_interrupts, err,
	    fail_cleanup);
	/* Get memory for the station queues */
	if ((err = iflib_queues_alloc(ctx))) {
		device_printf(dev, "Unable to allocate queue memory\n");
		goto fail_cleanup;
	}
	queues_allocated = true;

	if ((err = iflib_qset_structures_setup(ctx)))
		goto fail_cleanup;

	/*
	 * Now that we know how many queues there are, get the core offset.
	 */
	ctx->ifc_sysctl_core_offset = get_ctx_core_offset(ctx);
	IFLIB_REGISTER_FAIL_POINT(dev, register_after_queues, err,
	    fail_cleanup);

	if (msix > 1) {
		/*
		 * When using MSI-X, ensure that ifdi_{r,t}x_queue_intr_enable
		 * aren't the default NULL implementation.
		 */
		kobj_desc = &ifdi_rx_queue_intr_enable_desc;
		kobj_method = kobj_lookup_method(((kobj_t)ctx)->ops->cls, NULL,
		    kobj_desc);
		if (kobj_method == &kobj_desc->deflt) {
			device_printf(dev,
			    "MSI-X requires ifdi_rx_queue_intr_enable method");
			err = EOPNOTSUPP;
			goto fail_cleanup;
		}
		kobj_desc = &ifdi_tx_queue_intr_enable_desc;
		kobj_method = kobj_lookup_method(((kobj_t)ctx)->ops->cls, NULL,
		    kobj_desc);
		if (kobj_method == &kobj_desc->deflt) {
			device_printf(dev,
			    "MSI-X requires ifdi_tx_queue_intr_enable method");
			err = EOPNOTSUPP;
			goto fail_cleanup;
		}

		/*
		 * Assign the MSI-X vectors.
		 * Note that the default NULL ifdi_msix_intr_assign method will
		 * fail here, too.
		 */
		err = IFDI_MSIX_INTR_ASSIGN(ctx, msix);
		if (err != 0) {
			device_printf(dev, "IFDI_MSIX_INTR_ASSIGN failed %d\n",
			    err);
			goto fail_cleanup;
		}
	} else if (scctx->isc_intr != IFLIB_INTR_MSIX) {
		rid = 0;
		if (scctx->isc_intr == IFLIB_INTR_MSI) {
			MPASS(msix == 1);
			rid = 1;
		}
		if ((err = iflib_legacy_setup(ctx, ctx->isc_legacy_intr, ctx->ifc_softc, &rid, "irq0")) != 0) {
			device_printf(dev, "iflib_legacy_setup failed %d\n", err);
			goto fail_cleanup;
		}
	} else {
		device_printf(dev,
		    "Cannot use iflib with only 1 MSI-X interrupt!\n");
		err = ENODEV;
		goto fail_cleanup;
	}

	/*
	 * It prevents a double-locking panic with iflib_media_status when
	 * the driver loads.
	 */
	CTX_UNLOCK(ctx);
	ether_ifattach(ctx->ifc_ifp, ctx->ifc_mac.octet);
	CTX_LOCK(ctx);

	if ((err = IFDI_ATTACH_POST(ctx)) != 0) {
		device_printf(dev, "IFDI_ATTACH_POST failed %d\n", err);
		goto fail_detach;
	}
	IFLIB_REGISTER_FAIL_POINT(dev, register_after_attach_post, err,
	    fail_detach);

	/*
	 * Tell the upper layer(s) if IFCAP_VLAN_MTU is supported.
	 * This must appear after the call to ether_ifattach() because
	 * ether_ifattach() sets if_hdrlen to the default value.
	 */
	if (if_getcapabilities(ifp) & IFCAP_VLAN_MTU)
		if_setifheaderlen(ifp, sizeof(struct ether_vlan_header));

	if ((err = iflib_netmap_attach(ctx))) {
		device_printf(ctx->ifc_dev, "netmap attach failed: %d\n", err);
		goto fail_detach;
	}
	*ctxp = ctx;

	DEBUGNET_SET(ctx->ifc_ifp, iflib);

	iflib_add_device_sysctl_post(ctx);
	iflib_add_pfil(ctx);
	ctx->ifc_flags |= IFC_INIT_DONE;
	CTX_UNLOCK(ctx);

	/* Create led(4) devices if the driver defined the method */
	kobj_desc = &ifdi_led_func_desc;
	kobj_method = kobj_lookup_method(((kobj_t)ctx)->ops->cls, NULL,
	    kobj_desc);
	if (kobj_method != &kobj_desc->deflt && IFDI_LED_SUPPORTED(ctx))
		iflib_led_create(ctx);

	return (0);

fail_detach:
	STATE_LOCK(ctx);
	ctx->ifc_flags |= IFC_IN_DETACH;
	STATE_UNLOCK(ctx);
	/* Tasks may need the context lock; ether_ifdetach() may sleep. */
	CTX_UNLOCK(ctx);
	taskqueue_drain_all(ctx->ifc_tq);
#ifdef PCI_IOV
	/*
	 * IFDI_ATTACH_POST may have registered an SR-IOV schema.  Match the
	 * normal deregistration order so a failed attach cannot leave a stale
	 * /dev/iov node behind.  device_attach() holds Giant throughout this
	 * path, so an IOV configuration cannot race the detach.
	 */
	if (!CTX_IS_VF(ctx)) {
		iov_error = pci_iov_detach(dev);
		if (iov_error != 0)
			device_printf(dev, "Could not detach SR-IOV after "
			    "attach failure: %d\n", iov_error);
	}
#endif
	ether_ifdetach(ctx->ifc_ifp);
	CTX_LOCK(ctx);
	goto fail_cleanup_detaching;

fail_cleanup:
	STATE_LOCK(ctx);
	ctx->ifc_flags |= IFC_IN_DETACH;
	STATE_UNLOCK(ctx);

fail_cleanup_detaching:
	/*
	 * The pre-attach sysctls contain pointers into ctx.  Remove them on
	 * every registration failure before iflib_deregister() frees ctx.
	 */
	if (ctx->ifc_sysctl_node != NULL) {
		sysctl_ctx_free(&ctx->ifc_sysctl_ctx);
		ctx->ifc_sysctl_node = NULL;
	}

	if (ctx->ifc_tq != NULL) {
		/*
		 * Drain without holding the context lock so configuration tasks can
		 * run to completion.  On fail_detach a second drain also catches
		 * tasks queued during the first drain.
		 */
		CTX_UNLOCK(ctx);
		taskqueue_drain_all(ctx->ifc_tq);
		CTX_LOCK(ctx);
	}

	if (queues_allocated) {
		iflib_tqg_detach(ctx);
		iflib_tx_structures_free(ctx);
		iflib_rx_structures_free(ctx);
	}

	/*
	 * A successful IFDI_ATTACH_PRE must be matched by IFDI_DETACH, even
	 * when registration fails before queue allocation.  Match
	 * iflib_device_deregister by detaching before taskqueue_free.
	 */
	if (attach_pre_succeeded) {
		IFDI_DETACH(ctx);
		if (queues_allocated)
			IFDI_QUEUES_FREE(ctx);
	}
	if (ctx->ifc_tq != NULL) {
		taskqueue_free(ctx->ifc_tq);
		ctx->ifc_tq = NULL;
	}
	if (intr_allocated)
		iflib_free_intr_mem(ctx);

	CTX_UNLOCK(ctx);
	iflib_deregister(ctx);
	device_set_softc(ctx->ifc_dev, NULL);
	if (ctx->ifc_flags & IFC_SC_ALLOCATED)
		free(ctx->ifc_softc, M_IFLIB);
	unref_ctx_core_offset(ctx);
	free(ctx, M_IFLIB);
	return (err);
}

int
iflib_device_attach(device_t dev)
{
	if_ctx_t ctx;
	if_shared_ctx_t sctx;

	if ((sctx = DEVICE_REGISTER(dev)) == NULL || sctx->isc_magic != IFLIB_MAGIC)
		return (ENOTSUP);

	pci_enable_busmaster(dev);

	return (iflib_device_register(dev, NULL, sctx, &ctx));
}

int
iflib_device_deregister(if_ctx_t ctx)
{
	if_t ifp = ctx->ifc_ifp;
	device_t dev = ctx->ifc_dev;
	int error;

	/* Make sure VLANS are not using driver */
	if (if_vlantrunkinuse(ifp)) {
		device_printf(dev, "Vlan in use, detach first\n");
		return (EBUSY);
	}
#ifdef PCI_IOV
	if (!CTX_IS_VF(ctx) && pci_iov_detach(dev) != 0) {
		device_printf(dev, "SR-IOV in use; detach first.\n");
		return (EBUSY);
	}
#endif

	/*
	 * Establish any ordering required by the terminal stop while the
	 * interface is still intact.  Once this succeeds, mark the context
	 * inactive before releasing the lock so configuration tasks cannot
	 * consume partially applied policy.
	 */
	CTX_LOCK(ctx);
	error = IFDI_POWER_PREPARE(ctx, IFLIB_POWER_DETACH);
	if (error != 0) {
		CTX_UNLOCK(ctx);
		return (error);
	}
	STATE_LOCK(ctx);
	ctx->ifc_flags |= IFC_IN_DETACH;
	STATE_UNLOCK(ctx);
	ctx->ifc_pm_state = IFLIB_PM_SUSPENDING;
	CTX_UNLOCK(ctx);

	sysctl_ctx_free(&ctx->ifc_sysctl_ctx);
	ctx->ifc_sysctl_node = NULL;

	/* Unregister VLAN handlers before calling iflib_stop() */
	iflib_unregister_vlan_handlers(ctx);

	iflib_netmap_detach(ifp);
	/*
	 * A task that passed its IFC_IN_DETACH check before the flag was set
	 * can still report a link change.  Drain every private task before
	 * ether_ifdetach() performs the final if_linktask drain.  Drivers may
	 * register their own link-related tasks on this taskqueue.
	 */
	taskqueue_drain_all(ctx->ifc_tq);
	ether_ifdetach(ifp);

	CTX_LOCK(ctx);
	iflib_stop(ctx);
	CTX_UNLOCK(ctx);

	iflib_rem_pfil(ctx);
	if (ctx->ifc_led_dev != NULL) {
		led_destroy(ctx->ifc_led_dev);
		taskqueue_drain(ctx->ifc_tq, &ctx->ifc_led_task);
	}

	iflib_tqg_detach(ctx);
	iflib_tx_structures_free(ctx);
	iflib_rx_structures_free(ctx);

	CTX_LOCK(ctx);
	IFDI_DETACH(ctx);
	IFDI_QUEUES_FREE(ctx);
	CTX_UNLOCK(ctx);

	taskqueue_free(ctx->ifc_tq);
	ctx->ifc_tq = NULL;

	/* ether_ifdetach calls if_qflush - lock must be destroy afterwards*/
	iflib_free_intr_mem(ctx);

	bus_generic_detach(dev);

	iflib_deregister(ctx);

	device_set_softc(ctx->ifc_dev, NULL);
	if (ctx->ifc_flags & IFC_SC_ALLOCATED)
		free(ctx->ifc_softc, M_IFLIB);
	unref_ctx_core_offset(ctx);
	free(ctx, M_IFLIB);
	return (0);
}

static void
iflib_tqg_detach(if_ctx_t ctx)
{
	iflib_txq_t txq;
	iflib_rxq_t rxq;
	int i;
	struct taskqgroup *tqg;

	/* XXX drain any dependent tasks */
	tqg = qgroup_if_io_tqg;
	for (txq = ctx->ifc_txqs, i = 0; i < NTXQSETS(ctx); i++, txq++) {
		callout_drain(&txq->ift_timer);
#ifdef DEV_NETMAP
		callout_drain(&txq->ift_netmap_timer);
#endif /* DEV_NETMAP */
		if (txq->ift_task.gt_uniq != NULL)
			taskqgroup_detach(tqg, &txq->ift_task);
	}
	for (i = 0, rxq = ctx->ifc_rxqs; i < NRXQSETS(ctx); i++, rxq++) {
		if (rxq->ifr_task.gt_uniq != NULL)
			taskqgroup_detach(tqg, &rxq->ifr_task);
	}
}

static void
iflib_free_intr_mem(if_ctx_t ctx)
{

	if (ctx->ifc_softc_ctx.isc_intr != IFLIB_INTR_MSIX) {
		iflib_irq_free(ctx, &ctx->ifc_legacy_irq);
	}
	if (ctx->ifc_softc_ctx.isc_intr != IFLIB_INTR_LEGACY) {
		pci_release_msi(ctx->ifc_dev);
	}
	if (ctx->ifc_msix_mem != NULL) {
		bus_release_resource(ctx->ifc_dev, SYS_RES_MEMORY,
		    rman_get_rid(ctx->ifc_msix_mem), ctx->ifc_msix_mem);
		ctx->ifc_msix_mem = NULL;
	}
}

int
iflib_device_detach(device_t dev)
{
	if_ctx_t ctx = device_get_softc(dev);

	return (iflib_device_deregister(ctx));
}

static int
iflib_device_resume_locked(if_ctx_t ctx)
{
	if_t ifp;
	int error;

	sx_assert(&ctx->ifc_ctx_sx, SA_XLOCKED);
	KASSERT(ctx->ifc_datapath_state == IFLIB_DP_STOPPED,
	    ("iflib resume with active datapath state %d",
	    ctx->ifc_datapath_state));
	KASSERT(ctx->ifc_pm_state == IFLIB_PM_SUSPENDING ||
	    ctx->ifc_pm_state == IFLIB_PM_SUSPENDED,
	    ("iflib resume from power state %d", ctx->ifc_pm_state));

	ifp = ctx->ifc_ifp;
	error = IFDI_RESUME(ctx);
	if (error != 0)
		return (error);
	ctx->ifc_pm_state = IFLIB_PM_ACTIVE;

	if ((if_getflags(ifp) & IFF_UP) == 0) {
		if_setdrvflagbits(ifp, IFF_DRV_OACTIVE, IFF_DRV_RUNNING);
		return (0);
	}

	iflib_init_locked(ctx);
	return (0);
}

int
iflib_device_suspend(device_t dev)
{
	if_ctx_t ctx = device_get_softc(dev);
	int error, resume_error;

	CTX_LOCK(ctx);
	error = IFDI_POWER_PREPARE(ctx, IFLIB_POWER_SUSPEND);
	if (error == 0) {
		iflib_stop(ctx);
		ctx->ifc_pm_state = IFLIB_PM_SUSPENDING;
	}
	CTX_UNLOCK(ctx);
	if (error != 0)
		return (error);

	/* Driver configuration tasks must finish before entering low power. */
	taskqueue_drain_all(ctx->ifc_tq);

	CTX_LOCK(ctx);
	error = IFDI_SUSPEND(ctx);
	if (error == 0)
		ctx->ifc_pm_state = IFLIB_PM_SUSPENDED;
	else {
		resume_error = iflib_device_resume_locked(ctx);
		if (resume_error != 0)
			device_printf(dev,
			    "failed to resume after suspend error: %d\n",
			    resume_error);
	}
	CTX_UNLOCK(ctx);
	if (error != 0)
		return (error);

	error = bus_generic_suspend(dev);
	if (error != 0) {
		CTX_LOCK(ctx);
		resume_error = iflib_device_resume_locked(ctx);
		CTX_UNLOCK(ctx);
		if (resume_error != 0)
			device_printf(dev,
			    "failed to resume after child suspend error: %d\n",
			    resume_error);
	}

	return (error);
}

int
iflib_device_shutdown(device_t dev)
{
	if_ctx_t ctx = device_get_softc(dev);
	int error;

	CTX_LOCK(ctx);
	error = IFDI_POWER_PREPARE(ctx, IFLIB_POWER_SHUTDOWN);
	if (error == 0) {
		iflib_stop(ctx);
		ctx->ifc_pm_state = IFLIB_PM_SUSPENDING;
	}
	CTX_UNLOCK(ctx);
	if (error != 0)
		return (error);

	taskqueue_drain_all(ctx->ifc_tq);

	CTX_LOCK(ctx);
	error = IFDI_SHUTDOWN(ctx);
	if (error == 0)
		ctx->ifc_pm_state = IFLIB_PM_SUSPENDED;
	CTX_UNLOCK(ctx);
	if (error != 0)
		return (error);

	return (bus_generic_suspend(dev));
}

int
iflib_device_resume(device_t dev)
{
	if_ctx_t ctx = device_get_softc(dev);
	iflib_txq_t txq = ctx->ifc_txqs;
	bool running;
	int error, child_error;

	CTX_LOCK(ctx);
	error = iflib_device_resume_locked(ctx);
	running = (if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING) != 0;
	CTX_UNLOCK(ctx);
	if (running) {
		for (int i = 0; i < NTXQSETS(ctx); i++, txq++)
			iflib_txq_check_drain(txq, IFLIB_RESTART_BUDGET);
	}

	child_error = bus_generic_resume(dev);
	return (error != 0 ? error : child_error);
}

int
iflib_device_iov_init(device_t dev, uint16_t num_vfs, const nvlist_t *params)
{
	int error;
	if_ctx_t ctx = device_get_softc(dev);

	CTX_LOCK(ctx);
	error = IFDI_IOV_INIT(ctx, num_vfs, params);
	CTX_UNLOCK(ctx);

	return (error);
}

int
iflib_device_iov_init_restart(device_t dev, uint16_t num_vfs,
    const nvlist_t *params)
{
	if_ctx_t ctx;
	if_t ifp;
	bool restart, running;
	int error;

	ctx = device_get_softc(dev);
	ifp = ctx->ifc_ifp;

	CTX_LOCK(ctx);
	/*
	 * Drivers which change the PF queue layout need the complete iflib
	 * stop/init sequence around their IOV callback when the interface is
	 * active.  An administratively-down interface has no live queues to
	 * quiesce, and must remain down after the new layout is installed.
	 * Keep the transition within one context-lock critical section.
	 */
	restart = (if_getflags(ifp) & IFF_UP) != 0;
	running = (if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0;
	if (restart || running)
		iflib_stop(ctx);
	error = IFDI_IOV_INIT(ctx, num_vfs, params);
	if (restart)
		iflib_init_locked(ctx);
	CTX_UNLOCK(ctx);
	return (error);
}

void
iflib_device_iov_uninit(device_t dev)
{
	if_ctx_t ctx = device_get_softc(dev);

	CTX_LOCK(ctx);
	IFDI_IOV_UNINIT(ctx);
	CTX_UNLOCK(ctx);
}

void
iflib_device_iov_uninit_restart(device_t dev)
{
	if_ctx_t ctx;
	bool restart;

	ctx = device_get_softc(dev);

	CTX_LOCK(ctx);
	/*
	 * RUNNING can be clear while a watchdog reset is pending but the
	 * hardware is still live.  Always stop before the driver changes its
	 * queue layout, and use IFF_UP only to preserve administrative state.
	 */
	restart = (if_getflags(ctx->ifc_ifp) & IFF_UP) != 0;
	iflib_stop(ctx);
	IFDI_IOV_UNINIT(ctx);
	if (restart)
		iflib_init_locked(ctx);
	CTX_UNLOCK(ctx);
}

int
iflib_device_iov_add_vf(device_t dev, uint16_t vfnum, const nvlist_t *params)
{
	int error;
	if_ctx_t ctx = device_get_softc(dev);

	CTX_LOCK(ctx);
	error = IFDI_IOV_VF_ADD(ctx, vfnum, params);
	CTX_UNLOCK(ctx);

	return (error);
}

/*********************************************************************
 *
 *  MODULE FUNCTION DEFINITIONS
 *
 **********************************************************************/

static void
iflib_cpu_llc_init(void)
{
#ifdef SMP
	struct cpu_group *cg, *llc;
	uint16_t llc_id, first_llc_id;
	int cpu;
#endif

	iflib_single_llc = true;
#ifdef SMP
	first_llc_id = USHRT_MAX;
	for (cpu = 0; cpu <= mp_maxid; cpu++) {
		if (CPU_ABSENT(cpu))
			continue;

		/*
		 * Select the outermost shared-cache group containing this
		 * CPU.  On AMD systems this is the L3/CCX group.  This also
		 * gives sensible behavior when the llc is not L3.
		 */
		llc = NULL;
		for (cg = smp_topo_find(cpu_top, cpu); cg != NULL;
		    cg = cg->cg_parent) {
			if (cg->cg_level != CG_SHARE_NONE)
				llc = cg;
		}

		/* cg_first is a stable llc identifier. */
		llc_id = llc != NULL ? llc->cg_first : cpu;
		iflib_cpu_llc[cpu] = llc_id;
		if (first_llc_id == USHRT_MAX)
			first_llc_id = llc_id;
		else if (llc_id != first_llc_id)
			iflib_single_llc = false;
	}
#else
	iflib_cpu_llc[0] = 0;
#endif
	iflib_producer_gate = !iflib_single_llc ||
	    mp_ncpus > iflib_max_producers;
}

/*
 * - Start a fast taskqueue thread for each core
 * - Start a taskqueue for control operations
 */
static int
iflib_module_init(void)
{
	iflib_timer_default = hz / 2;
	iflib_cpu_llc_init();

	if (iflib_simple_txbr_size < IFLIB_SIMPLE_TXBR_MIN ||
	    !powerof2(iflib_simple_txbr_size)) {
		printf("iflib: simple_txbr_size %d is not a power of 2 >= %d "
		    "- using default value of %d\n", iflib_simple_txbr_size,
		    IFLIB_SIMPLE_TXBR_MIN, IFLIB_SIMPLE_TXBR_SIZE);
		iflib_simple_txbr_size = IFLIB_SIMPLE_TXBR_SIZE;
	}
	return (0);
}

static int
iflib_module_event_handler(module_t mod, int what, void *arg)
{
	int err;

	switch (what) {
	case MOD_LOAD:
		if ((err = iflib_module_init()) != 0)
			return (err);
		break;
	case MOD_UNLOAD:
		return (EBUSY);
	default:
		return (EOPNOTSUPP);
	}

	return (0);
}

/*********************************************************************
 *
 *  PUBLIC FUNCTION DEFINITIONS
 *     ordered as in iflib.h
 *
 **********************************************************************/

static void
_iflib_assert(if_shared_ctx_t sctx)
{
	int i;

	MPASS(sctx->isc_tx_maxsize);
	MPASS(sctx->isc_tx_maxsegsize);

	MPASS(sctx->isc_rx_maxsize);
	MPASS(sctx->isc_rx_nsegments);
	MPASS(sctx->isc_rx_maxsegsize);

	MPASS(sctx->isc_nrxqs >= 1 && sctx->isc_nrxqs <= 8);
	for (i = 0; i < sctx->isc_nrxqs; i++) {
		MPASS(sctx->isc_nrxd_min[i]);
		MPASS(powerof2(sctx->isc_nrxd_min[i]));
		MPASS(sctx->isc_nrxd_max[i]);
		MPASS(powerof2(sctx->isc_nrxd_max[i]));
		MPASS(sctx->isc_nrxd_default[i]);
		MPASS(powerof2(sctx->isc_nrxd_default[i]));
	}

	MPASS(sctx->isc_ntxqs >= 1 && sctx->isc_ntxqs <= 8);
	for (i = 0; i < sctx->isc_ntxqs; i++) {
		MPASS(sctx->isc_ntxd_min[i]);
		MPASS(powerof2(sctx->isc_ntxd_min[i]));
		MPASS(sctx->isc_ntxd_max[i]);
		MPASS(powerof2(sctx->isc_ntxd_max[i]));
		MPASS(sctx->isc_ntxd_default[i]);
		MPASS(powerof2(sctx->isc_ntxd_default[i]));
	}
}

static void
_iflib_pre_assert(if_softc_ctx_t scctx)
{

	MPASS(scctx->isc_txrx->ift_txd_encap);
	MPASS(scctx->isc_txrx->ift_txd_flush);
	MPASS(scctx->isc_txrx->ift_txd_credits_update);
	MPASS(scctx->isc_txrx->ift_rxd_available);
	MPASS(scctx->isc_txrx->ift_rxd_pkt_get);
	MPASS(scctx->isc_txrx->ift_rxd_refill);
	MPASS(scctx->isc_txrx->ift_rxd_flush);
}

static void
iflib_register(if_ctx_t ctx)
{
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	driver_t *driver = sctx->isc_driver;
	device_t dev = ctx->ifc_dev;
	if_t ifp;

	_iflib_assert(sctx);

	CTX_LOCK_INIT(ctx);
	STATE_LOCK_INIT(ctx, device_get_nameunit(ctx->ifc_dev));
	ifp = ctx->ifc_ifp = if_alloc_dev(IFT_ETHER, dev);

	/*
	 * Initialize our context's device specific methods
	 */
	kobj_init((kobj_t) ctx, (kobj_class_t) driver);
	kobj_class_compile((kobj_class_t) driver);

	if_initname(ifp, device_get_name(dev), device_get_unit(dev));
	if_setsoftc(ifp, ctx);
	if_setdev(ifp, dev);
	if_setinitfn(ifp, iflib_if_init);
	if_setioctlfn(ifp, iflib_if_ioctl);
	/* VF status describes children of an SR-IOV PF. */
	if (!CTX_IS_VF(ctx))
		if_setvfstatusfn(ifp, iflib_if_vf_status);
#ifdef ALTQ
	if_setstartfn(ifp, iflib_altq_if_start);
	if_settransmitfn(ifp, iflib_altq_if_transmit);
	if_setsendqready(ifp);
#else
	if_settransmitfn(ifp, iflib_if_transmit);
#endif
	if_setqflushfn(ifp, iflib_if_qflush);
	if_setgetcounterfn(ifp, iflib_if_get_counter);
	if_setflags(ifp, IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
	ctx->ifc_vlan_attach_event =
	    EVENTHANDLER_REGISTER(vlan_config, iflib_vlan_register, ctx,
		    EVENTHANDLER_PRI_FIRST);
	ctx->ifc_vlan_detach_event =
	    EVENTHANDLER_REGISTER(vlan_unconfig, iflib_vlan_unregister, ctx,
		    EVENTHANDLER_PRI_FIRST);

	if ((sctx->isc_flags & IFLIB_DRIVER_MEDIA) == 0) {
		ctx->ifc_mediap = &ctx->ifc_media;
		ifmedia_init(ctx->ifc_mediap, IFM_IMASK,
		    iflib_media_change, iflib_media_status);
	}
}

static void
iflib_unregister_vlan_handlers(if_ctx_t ctx)
{
	/* Unregister VLAN events */
	if (ctx->ifc_vlan_attach_event != NULL) {
		EVENTHANDLER_DEREGISTER(vlan_config, ctx->ifc_vlan_attach_event);
		ctx->ifc_vlan_attach_event = NULL;
	}
	if (ctx->ifc_vlan_detach_event != NULL) {
		EVENTHANDLER_DEREGISTER(vlan_unconfig, ctx->ifc_vlan_detach_event);
		ctx->ifc_vlan_detach_event = NULL;
	}

}

static void
iflib_deregister(if_ctx_t ctx)
{
	if_t ifp = ctx->ifc_ifp;

	/* Remove all media */
	ifmedia_removeall(&ctx->ifc_media);

	/* Ensure that VLAN event handlers are unregistered */
	iflib_unregister_vlan_handlers(ctx);

	/* Release kobject reference */
	kobj_delete((kobj_t) ctx, NULL);

	/* Free the ifnet structure */
	if_free(ifp);

	STATE_LOCK_DESTROY(ctx);

	/* ether_ifdetach calls if_qflush - lock must be destroy afterwards*/
	CTX_LOCK_DESTROY(ctx);
}

static int
iflib_queues_alloc(if_ctx_t ctx)
{
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	device_t dev = ctx->ifc_dev;
	int nrxqsets = scctx->isc_nrxqsets;
	int ntxqsets = scctx->isc_ntxqsets;
	iflib_txq_t txq;
	iflib_rxq_t rxq;
	iflib_fl_t fl = NULL;
	int i, j, cpu, err;
	iflib_dma_info_t ifdip;
	uint32_t *rxqsizes = scctx->isc_rxqsizes;
	uint32_t *txqsizes = scctx->isc_txqsizes;
	uint8_t nrxqs = sctx->isc_nrxqs;
	uint8_t ntxqs = sctx->isc_ntxqs;
	int nfree_lists = sctx->isc_nfl ? sctx->isc_nfl : 1;
	int fl_offset = (sctx->isc_flags & IFLIB_HAS_RXCQ ? 1 : 0);
	caddr_t *vaddrs;
	uint64_t *paddrs;

	KASSERT(ntxqs > 0, ("number of queues per qset must be at least 1"));
	KASSERT(nrxqs > 0, ("number of queues per qset must be at least 1"));
	KASSERT(nrxqs >= fl_offset + nfree_lists,
	    ("there must be at least a rxq for each free list"));

	/* Allocate the TX ring struct memory */
	if (!(ctx->ifc_txqs =
	    (iflib_txq_t) malloc(sizeof(struct iflib_txq) *
		    ntxqsets, M_IFLIB, M_NOWAIT | M_ZERO))) {
		device_printf(dev, "Unable to allocate TX ring memory\n");
		err = ENOMEM;
		goto fail;
	}

	/* Now allocate the RX */
	if (!(ctx->ifc_rxqs =
	    (iflib_rxq_t) malloc(sizeof(struct iflib_rxq) *
		    nrxqsets, M_IFLIB, M_NOWAIT | M_ZERO))) {
		device_printf(dev, "Unable to allocate RX ring memory\n");
		err = ENOMEM;
		goto rx_fail;
	}

	txq = ctx->ifc_txqs;
	rxq = ctx->ifc_rxqs;

	/*
	 * XXX handle allocation failure
	 */
	for (i = 0, cpu = CPU_FIRST(); i < ntxqsets; i++, txq++, cpu = CPU_NEXT(cpu)) {
		/* Set up some basics */

		if ((ifdip = malloc(sizeof(struct iflib_dma_info) * ntxqs,
		    M_IFLIB, M_NOWAIT | M_ZERO)) == NULL) {
			device_printf(dev,
			    "Unable to allocate TX DMA info memory\n");
			err = ENOMEM;
			goto err_tx_desc;
		}
		txq->ift_ifdi = ifdip;
		for (j = 0; j < ntxqs; j++, ifdip++) {
			if (iflib_dma_alloc(ctx, txqsizes[j], ifdip, 0)) {
				device_printf(dev,
				    "Unable to allocate TX descriptors\n");
				err = ENOMEM;
				goto err_tx_desc;
			}
			txq->ift_txd_size[j] = scctx->isc_txd_size[j];
			bzero((void *)ifdip->idi_vaddr, txqsizes[j]);
		}
		txq->ift_ctx = ctx;
		txq->ift_id = i;
		if (sctx->isc_flags & IFLIB_HAS_TXCQ) {
			txq->ift_br_offset = 1;
		} else {
			txq->ift_br_offset = 0;
		}

		if (iflib_txsd_alloc(txq)) {
			device_printf(dev, "Critical Failure setting up TX buffers\n");
			err = ENOMEM;
			goto err_tx_desc;
		}

		/* Initialize the TX lock */
		snprintf(txq->ift_mtx_name, MTX_NAME_LEN, "%s:TX(%d):callout",
		    device_get_nameunit(dev), txq->ift_id);
		mtx_init(&txq->ift_mtx, txq->ift_mtx_name, NULL, MTX_DEF);
		callout_init_mtx(&txq->ift_timer, &txq->ift_mtx, 0);
		txq->ift_timer.c_cpu = cpu;
#ifdef DEV_NETMAP
		callout_init_mtx(&txq->ift_netmap_timer, &txq->ift_mtx, 0);
		txq->ift_netmap_timer.c_cpu = cpu;
#endif /* DEV_NETMAP */

		err = ifmp_ring_alloc(&txq->ift_br, 2048, txq, iflib_txq_drain,
		    iflib_txq_can_drain, M_IFLIB, M_WAITOK);
		if (err) {
			/* XXX free any allocated rings */
			device_printf(dev, "Unable to allocate buf_ring\n");
			goto err_tx_desc;
		}
		if (ctx->ifc_sysctl_simple_tx) {
			txq->ift_drbr = buf_ring_alloc(iflib_simple_txbr_size,
			    M_IFLIB, M_WAITOK, &txq->ift_mtx);
			txq->ift_drbr_deferred = counter_u64_alloc(M_WAITOK);
			txq->ift_drbr_drops = counter_u64_alloc(M_WAITOK);
			txq->ift_drbr_blocked = counter_u64_alloc(M_WAITOK);
			txq->ift_drbr_remote = counter_u64_alloc(M_WAITOK);
		}
		txq->ift_reclaim_thresh = ctx->ifc_sysctl_tx_reclaim_thresh;
	}

	for (i = 0; i < nrxqsets; i++, rxq++) {
		/* Set up some basics */
		callout_init(&rxq->ifr_watchdog, 1);

		if ((ifdip = malloc(sizeof(struct iflib_dma_info) * nrxqs,
		    M_IFLIB, M_NOWAIT | M_ZERO)) == NULL) {
			device_printf(dev,
			    "Unable to allocate RX DMA info memory\n");
			err = ENOMEM;
			goto err_tx_desc;
		}

		rxq->ifr_ifdi = ifdip;
		/* XXX this needs to be changed if #rx queues != #tx queues */
		rxq->ifr_ntxqirq = 1;
		rxq->ifr_txqid[0] = i;
		for (j = 0; j < nrxqs; j++, ifdip++) {
			if (iflib_dma_alloc(ctx, rxqsizes[j], ifdip, 0)) {
				device_printf(dev,
				    "Unable to allocate RX descriptors\n");
				err = ENOMEM;
				goto err_tx_desc;
			}
			bzero((void *)ifdip->idi_vaddr, rxqsizes[j]);
		}
		rxq->ifr_ctx = ctx;
		rxq->ifr_id = i;
		rxq->ifr_fl_offset = fl_offset;
		rxq->ifr_nfl = nfree_lists;
		if (!(fl =
		    (iflib_fl_t) malloc(sizeof(struct iflib_fl) * nfree_lists, M_IFLIB, M_NOWAIT | M_ZERO))) {
			device_printf(dev, "Unable to allocate free list memory\n");
			err = ENOMEM;
			goto err_tx_desc;
		}
		rxq->ifr_fl = fl;
		for (j = 0; j < nfree_lists; j++) {
			fl[j].ifl_rxq = rxq;
			fl[j].ifl_id = j;
			fl[j].ifl_ifdi = &rxq->ifr_ifdi[j + rxq->ifr_fl_offset];
			fl[j].ifl_rxd_size = scctx->isc_rxd_size[j];
		}
		/* Allocate receive buffers for the ring */
		if (iflib_rxsd_alloc(rxq)) {
			device_printf(dev,
			    "Critical Failure setting up receive buffers\n");
			err = ENOMEM;
			goto err_rx_desc;
		}

		for (j = 0, fl = rxq->ifr_fl; j < rxq->ifr_nfl; j++, fl++)
			fl->ifl_rx_bitmap = bit_alloc(fl->ifl_size, M_IFLIB,
			    M_WAITOK);
	}

	/* TXQs */
	vaddrs = malloc(sizeof(caddr_t)  * ntxqsets * ntxqs, M_IFLIB, M_WAITOK);
	paddrs = malloc(sizeof(uint64_t) * ntxqsets * ntxqs, M_IFLIB, M_WAITOK);
	for (i = 0; i < ntxqsets; i++) {
		iflib_dma_info_t di = ctx->ifc_txqs[i].ift_ifdi;

		for (j = 0; j < ntxqs; j++, di++) {
			vaddrs[i * ntxqs + j] = di->idi_vaddr;
			paddrs[i * ntxqs + j] = di->idi_paddr;
		}
	}
	if ((err = IFDI_TX_QUEUES_ALLOC(ctx, vaddrs, paddrs, ntxqs, ntxqsets)) != 0) {
		device_printf(ctx->ifc_dev,
		    "Unable to allocate device TX queue\n");
		iflib_tx_structures_free(ctx);
		free(vaddrs, M_IFLIB);
		free(paddrs, M_IFLIB);
		goto err_rx_desc;
	}
	free(vaddrs, M_IFLIB);
	free(paddrs, M_IFLIB);

	/* RXQs */
	vaddrs = malloc(sizeof(caddr_t)  * nrxqsets * nrxqs, M_IFLIB, M_WAITOK);
	paddrs = malloc(sizeof(uint64_t) * nrxqsets * nrxqs, M_IFLIB, M_WAITOK);
	for (i = 0; i < nrxqsets; i++) {
		iflib_dma_info_t di = ctx->ifc_rxqs[i].ifr_ifdi;

		for (j = 0; j < nrxqs; j++, di++) {
			vaddrs[i * nrxqs + j] = di->idi_vaddr;
			paddrs[i * nrxqs + j] = di->idi_paddr;
		}
	}
	if ((err = IFDI_RX_QUEUES_ALLOC(ctx, vaddrs, paddrs, nrxqs, nrxqsets)) != 0) {
		device_printf(ctx->ifc_dev,
		    "Unable to allocate device RX queue\n");
		iflib_tx_structures_free(ctx);
		free(vaddrs, M_IFLIB);
		free(paddrs, M_IFLIB);
		goto err_rx_desc;
	}
	free(vaddrs, M_IFLIB);
	free(paddrs, M_IFLIB);

	return (0);

/* XXX handle allocation failure changes */
err_rx_desc:
err_tx_desc:
rx_fail:
	if (ctx->ifc_rxqs != NULL)
		free(ctx->ifc_rxqs, M_IFLIB);
	ctx->ifc_rxqs = NULL;
	if (ctx->ifc_txqs != NULL)
		free(ctx->ifc_txqs, M_IFLIB);
	ctx->ifc_txqs = NULL;
fail:
	return (err);
}

static int
iflib_tx_structures_setup(if_ctx_t ctx)
{
	iflib_txq_t txq = ctx->ifc_txqs;
	int i;

	for (i = 0; i < NTXQSETS(ctx); i++, txq++)
		iflib_txq_setup(txq);

	return (0);
}

static void
iflib_tx_structures_free(if_ctx_t ctx)
{
	iflib_txq_t txq = ctx->ifc_txqs;
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	int i, j;

	for (i = 0; i < NTXQSETS(ctx); i++, txq++) {
		for (j = 0; j < sctx->isc_ntxqs; j++)
			iflib_dma_free(&txq->ift_ifdi[j]);
		iflib_txq_destroy(txq);
	}
	free(ctx->ifc_txqs, M_IFLIB);
	ctx->ifc_txqs = NULL;
}

/*********************************************************************
 *
 *  Initialize all receive rings.
 *
 **********************************************************************/
static int
iflib_rx_structures_setup(if_ctx_t ctx)
{
	iflib_rxq_t rxq = ctx->ifc_rxqs;
	int q;
#if defined(INET6) || defined(INET)
	int err, i;
#endif

	for (q = 0; q < ctx->ifc_softc_ctx.isc_nrxqsets; q++, rxq++) {
#if defined(INET6) || defined(INET)
		err = tcp_lro_init_args(&rxq->ifr_lc, ctx->ifc_ifp,
		    TCP_LRO_ENTRIES, min(1024,
		    ctx->ifc_softc_ctx.isc_nrxd[rxq->ifr_fl_offset]));
		if (err != 0) {
			device_printf(ctx->ifc_dev,
			    "LRO Initialization failed!\n");
			goto fail;
		}
#endif
		IFDI_RXQ_SETUP(ctx, rxq->ifr_id);
	}
	return (0);
#if defined(INET6) || defined(INET)
fail:
	/*
	 * Free LRO resources allocated so far, we will only handle
	 * the rings that completed, the failing case will have
	 * cleaned up for itself.  'q' failed, so its the terminus.
	 */
	rxq = ctx->ifc_rxqs;
	for (i = 0; i < q; ++i, rxq++) {
		tcp_lro_free(&rxq->ifr_lc);
	}
	return (err);
#endif
}

/*********************************************************************
 *
 *  Free all receive rings.
 *
 **********************************************************************/
static void
iflib_rx_structures_free(if_ctx_t ctx)
{
	iflib_rxq_t rxq = ctx->ifc_rxqs;
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	int i, j;

	for (i = 0; i < ctx->ifc_softc_ctx.isc_nrxqsets; i++, rxq++) {
		for (j = 0; j < sctx->isc_nrxqs; j++)
			iflib_dma_free(&rxq->ifr_ifdi[j]);
		iflib_rx_sds_free(rxq);
#if defined(INET6) || defined(INET)
		tcp_lro_free(&rxq->ifr_lc);
#endif
	}
	free(ctx->ifc_rxqs, M_IFLIB);
	ctx->ifc_rxqs = NULL;
}

static int
iflib_qset_structures_setup(if_ctx_t ctx)
{
	int err;

	/*
	 * It is expected that the caller takes care of freeing queues if this
	 * fails.
	 */
	if ((err = iflib_tx_structures_setup(ctx)) != 0) {
		device_printf(ctx->ifc_dev, "iflib_tx_structures_setup failed: %d\n", err);
		return (err);
	}

	if ((err = iflib_rx_structures_setup(ctx)) != 0)
		device_printf(ctx->ifc_dev, "iflib_rx_structures_setup failed: %d\n", err);

	return (err);
}

int
iflib_irq_alloc(if_ctx_t ctx, if_irq_t irq, int rid,
		driver_filter_t filter, void *filter_arg, driver_intr_t handler, void *arg, const char *name)
{

	return (_iflib_irq_alloc(ctx, irq, rid, filter, handler, arg, name));
}

/* Just to avoid copy/paste */
static inline int
iflib_irq_set_affinity(if_ctx_t ctx, if_irq_t irq, iflib_intr_type_t type,
    int qid, struct grouptask *gtask, struct taskqgroup *tqg, void *uniq,
    const char *name)
{
	device_t dev;
	unsigned int base_cpuid, cpuid;
	int err;

	dev = ctx->ifc_dev;
	base_cpuid = ctx->ifc_sysctl_core_offset;
	cpuid = get_cpuid_for_queue(ctx, base_cpuid, qid, type == IFLIB_INTR_TX);
	err = taskqgroup_attach_cpu(tqg, gtask, uniq, cpuid, dev,
	    irq ? irq->ii_res : NULL, name);
	if (err) {
		device_printf(dev, "taskqgroup_attach_cpu failed %d\n", err);
		return (err);
	}
#ifdef notyet
	if (cpuid > ctx->ifc_cpuid_highest)
		ctx->ifc_cpuid_highest = cpuid;
#endif
	return (0);
}

/*
 * Allocate a hardware interrupt for subctx using the parent (ctx)'s hardware
 * resources.
 *
 * Similar to iflib_irq_alloc_generic(), but for interrupt type IFLIB_INTR_RXTX
 * only.
 *
 * XXX: Could be removed if subctx's dev has its intr resource allocation
 * methods replaced with custom ones?
 */
int
iflib_irq_alloc_generic_subctx(if_ctx_t ctx, if_ctx_t subctx, if_irq_t irq,
			       int rid, iflib_intr_type_t type,
			       driver_filter_t *filter, void *filter_arg,
			       int qid, const char *name)
{
	device_t dev, subdev;
	struct grouptask *gtask;
	struct taskqgroup *tqg;
	iflib_filter_info_t info;
	gtask_fn_t *fn;
	int tqrid, err;
	driver_filter_t *intr_fast;
	void *q;

	MPASS(ctx != NULL);
	MPASS(subctx != NULL);

	tqrid = rid;
	dev = ctx->ifc_dev;
	subdev = subctx->ifc_dev;

	switch (type) {
	case IFLIB_INTR_RXTX:
		q = &subctx->ifc_rxqs[qid];
		info = &subctx->ifc_rxqs[qid].ifr_filter_info;
		gtask = &subctx->ifc_rxqs[qid].ifr_task;
		tqg = qgroup_if_io_tqg;
		fn = _task_fn_rx;
		intr_fast = iflib_fast_intr_rxtx;
		NET_GROUPTASK_INIT(gtask, 0, fn, q);
		break;
	default:
		device_printf(dev, "%s: unknown net intr type for subctx %s (%d)\n",
		    __func__, device_get_nameunit(subdev), type);
		return (EINVAL);
	}

	info->ifi_filter = filter;
	info->ifi_filter_arg = filter_arg;
	info->ifi_task = gtask;
	info->ifi_ctx = q;

	NET_GROUPTASK_INIT(gtask, 0, fn, q);

	/* Allocate interrupts from hardware using parent context */
	err = _iflib_irq_alloc(ctx, irq, rid, intr_fast, NULL, info, name);
	if (err != 0) {
		device_printf(dev, "_iflib_irq_alloc failed for subctx %s: %d\n",
		    device_get_nameunit(subdev), err);
		return (err);
	}

	if (tqrid != -1) {
		err = iflib_irq_set_affinity(ctx, irq, type, qid, gtask, tqg, q,
		    name);
		if (err)
			return (err);
	} else {
		taskqgroup_attach(tqg, gtask, q, dev, irq->ii_res, name);
	}

	return (0);
}

int
iflib_irq_alloc_generic(if_ctx_t ctx, if_irq_t irq, int rid,
			iflib_intr_type_t type, driver_filter_t *filter,
			void *filter_arg, int qid, const char *name)
{
	device_t dev;
	struct grouptask *gtask;
	struct taskqgroup *tqg;
	iflib_filter_info_t info;
	gtask_fn_t *fn;
	int tqrid, err;
	driver_filter_t *intr_fast;
	void *q;

	info = &ctx->ifc_filter_info;
	tqrid = rid;

	switch (type) {
	/* XXX merge tx/rx for netmap? */
	case IFLIB_INTR_TX:
		q = &ctx->ifc_txqs[qid];
		info = &ctx->ifc_txqs[qid].ift_filter_info;
		gtask = &ctx->ifc_txqs[qid].ift_task;
		tqg = qgroup_if_io_tqg;
		fn = _task_fn_tx;
		intr_fast = iflib_fast_intr;
		GROUPTASK_INIT(gtask, 0, fn, q);
		ctx->ifc_flags |= IFC_NETMAP_TX_IRQ;
		break;
	case IFLIB_INTR_RX:
		q = &ctx->ifc_rxqs[qid];
		info = &ctx->ifc_rxqs[qid].ifr_filter_info;
		gtask = &ctx->ifc_rxqs[qid].ifr_task;
		tqg = qgroup_if_io_tqg;
		fn = _task_fn_rx;
		intr_fast = iflib_fast_intr;
		NET_GROUPTASK_INIT(gtask, 0, fn, q);
		break;
	case IFLIB_INTR_RXTX:
		q = &ctx->ifc_rxqs[qid];
		info = &ctx->ifc_rxqs[qid].ifr_filter_info;
		gtask = &ctx->ifc_rxqs[qid].ifr_task;
		tqg = qgroup_if_io_tqg;
		fn = _task_fn_rx;
		intr_fast = iflib_fast_intr_rxtx;
		NET_GROUPTASK_INIT(gtask, 0, fn, q);
		break;
	case IFLIB_INTR_ADMIN:
		q = ctx;
		tqrid = -1;
		info = &ctx->ifc_filter_info;
		gtask = NULL;
		intr_fast = iflib_fast_intr_ctx;
		break;
	default:
		device_printf(ctx->ifc_dev, "%s: unknown net intr type\n",
		    __func__);
		return (EINVAL);
	}

	info->ifi_filter = filter;
	info->ifi_filter_arg = filter_arg;
	info->ifi_task = gtask;
	info->ifi_ctx = q;

	dev = ctx->ifc_dev;
	err = _iflib_irq_alloc(ctx, irq, rid, intr_fast, NULL, info,  name);
	if (err != 0) {
		device_printf(dev, "_iflib_irq_alloc failed %d\n", err);
		return (err);
	}
	if (type == IFLIB_INTR_ADMIN)
		return (0);

	if (tqrid != -1) {
		err = iflib_irq_set_affinity(ctx, irq, type, qid, gtask, tqg, q,
		    name);
		if (err)
			return (err);
	} else {
		taskqgroup_attach(tqg, gtask, q, dev, irq->ii_res, name);
	}

	return (0);
}

void
iflib_softirq_alloc_generic(if_ctx_t ctx, if_irq_t irq, iflib_intr_type_t type,
			    void *arg, int qid, const char *name)
{
	device_t dev;
	struct grouptask *gtask;
	struct taskqgroup *tqg;
	gtask_fn_t *fn;
	void *q;
	int err;

	switch (type) {
	case IFLIB_INTR_TX:
		q = &ctx->ifc_txqs[qid];
		gtask = &ctx->ifc_txqs[qid].ift_task;
		tqg = qgroup_if_io_tqg;
		fn = _task_fn_tx;
		GROUPTASK_INIT(gtask, 0, fn, q);
		break;
	case IFLIB_INTR_RX:
		q = &ctx->ifc_rxqs[qid];
		gtask = &ctx->ifc_rxqs[qid].ifr_task;
		tqg = qgroup_if_io_tqg;
		fn = _task_fn_rx;
		NET_GROUPTASK_INIT(gtask, 0, fn, q);
		break;
	case IFLIB_INTR_IOV:
		return;
	default:
		panic("unknown net intr type");
	}
	err = iflib_irq_set_affinity(ctx, irq, type, qid, gtask, tqg, q, name);
	if (err) {
		dev = ctx->ifc_dev;
		taskqgroup_attach(tqg, gtask, q, dev, irq ? irq->ii_res : NULL,
		    name);
	}
}

void
iflib_irq_free(if_ctx_t ctx, if_irq_t irq)
{

	if (irq->ii_tag)
		bus_teardown_intr(ctx->ifc_dev, irq->ii_res, irq->ii_tag);

	if (irq->ii_res)
		bus_release_resource(ctx->ifc_dev, SYS_RES_IRQ,
		    rman_get_rid(irq->ii_res), irq->ii_res);
}

static int
iflib_legacy_setup(if_ctx_t ctx, driver_filter_t filter, void *filter_arg, int *rid, const char *name)
{
	iflib_txq_t txq = ctx->ifc_txqs;
	iflib_rxq_t rxq = ctx->ifc_rxqs;
	if_irq_t irq = &ctx->ifc_legacy_irq;
	iflib_filter_info_t info;
	device_t dev;
	struct grouptask *gtask;
	struct resource *res;
	int err, tqrid;
	bool rx_only;

	info = &rxq->ifr_filter_info;
	gtask = &rxq->ifr_task;
	tqrid = *rid;
	rx_only = (ctx->ifc_sctx->isc_flags & IFLIB_SINGLE_IRQ_RX_ONLY) != 0;

	ctx->ifc_flags |= IFC_LEGACY;
	info->ifi_filter = filter;
	info->ifi_filter_arg = filter_arg;
	info->ifi_task = gtask;
	info->ifi_ctx = rxq;

	dev = ctx->ifc_dev;
	/* We allocate a single interrupt resource */
	err = _iflib_irq_alloc(ctx, irq, tqrid, rx_only ? iflib_fast_intr :
	    iflib_fast_intr_rxtx, NULL, info, name);
	if (err != 0)
		return (err);
	NET_GROUPTASK_INIT(gtask, 0, _task_fn_rx, rxq);
	res = irq->ii_res;
	taskqgroup_attach(qgroup_if_io_tqg, gtask, rxq, dev, res, name);

	GROUPTASK_INIT(&txq->ift_task, 0, _task_fn_tx, txq);
	taskqgroup_attach(qgroup_if_io_tqg, &txq->ift_task, txq, dev, res,
	    "tx");
	return (0);
}

void
iflib_led_create(if_ctx_t ctx)
{

	ctx->ifc_led_dev = led_create(iflib_led_func, ctx,
	    device_get_nameunit(ctx->ifc_dev));
}

void
iflib_tx_intr_deferred(if_ctx_t ctx, int txqid)
{

	GROUPTASK_ENQUEUE(&ctx->ifc_txqs[txqid].ift_task);
}

void
iflib_rx_intr_deferred(if_ctx_t ctx, int rxqid)
{

	GROUPTASK_ENQUEUE(&ctx->ifc_rxqs[rxqid].ifr_task);
}

void
iflib_admin_intr_deferred(if_ctx_t ctx)
{

	taskqueue_enqueue(ctx->ifc_tq, &ctx->ifc_admin_task);
}

void
iflib_iov_intr_deferred(if_ctx_t ctx)
{

	taskqueue_enqueue(ctx->ifc_tq, &ctx->ifc_vflr_task);
}

void
iflib_io_tqg_attach(struct grouptask *gt, void *uniq, int cpu, const char *name)
{

	taskqgroup_attach_cpu(qgroup_if_io_tqg, gt, uniq, cpu, NULL, NULL,
	    name);
}

void
iflib_config_task_init(if_ctx_t ctx, struct task *config_task, task_fn_t *fn)
{
	TASK_INIT(config_task, 0, fn, ctx);
}

void
iflib_config_task_enqueue(if_ctx_t ctx, struct task *config_task)
{
	taskqueue_enqueue(ctx->ifc_tq, config_task);
}

void
iflib_link_state_change(if_ctx_t ctx, int link_state, uint64_t baudrate)
{
	if_t ifp = ctx->ifc_ifp;

	if_setbaudrate(ifp, baudrate);
	if (baudrate >= IF_Gbps(10)) {
		STATE_LOCK(ctx);
		ctx->ifc_flags |= IFC_PREFETCH;
		STATE_UNLOCK(ctx);
	}
	ctx->ifc_link_state = link_state;
	if_link_state_change(ifp, link_state);
}

static int
iflib_tx_credits_update(if_ctx_t ctx, iflib_txq_t txq)
{
	int credits;
#ifdef INVARIANTS
	int credits_pre = txq->ift_cidx_processed;
#endif

	bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
	    BUS_DMASYNC_POSTREAD);
	if ((credits = ctx->isc_txd_credits_update(ctx->ifc_softc, txq->ift_id, true)) == 0)
		return (0);

	txq->ift_processed += credits;
	txq->ift_cidx_processed += credits;

	MPASS(credits_pre + credits == txq->ift_cidx_processed);
	if (txq->ift_cidx_processed >= txq->ift_size)
		txq->ift_cidx_processed -= txq->ift_size;
	return (credits);
}

static int
iflib_rxd_avail(if_ctx_t ctx, iflib_rxq_t rxq, qidx_t cidx, qidx_t budget)
{
	iflib_fl_t fl;
	u_int i;

	for (i = 0, fl = &rxq->ifr_fl[0]; i < rxq->ifr_nfl; i++, fl++)
		bus_dmamap_sync(fl->ifl_ifdi->idi_tag, fl->ifl_ifdi->idi_map,
		    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
	return (ctx->isc_rxd_available(ctx->ifc_softc, rxq->ifr_id, cidx,
	    budget));
}

void
iflib_add_int_delay_sysctl(if_ctx_t ctx, const char *name,
	const char *description, if_int_delay_info_t info,
	int offset, int value)
{
	info->iidi_ctx = ctx;
	info->iidi_offset = offset;
	info->iidi_value = value;
	SYSCTL_ADD_PROC(device_get_sysctl_ctx(ctx->ifc_dev),
	    SYSCTL_CHILDREN(device_get_sysctl_tree(ctx->ifc_dev)),
	    OID_AUTO, name, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
	    info, 0, iflib_sysctl_int_delay, "I", description);
}

struct sx *
iflib_ctx_lock_get(if_ctx_t ctx)
{

	return (&ctx->ifc_ctx_sx);
}

static int
iflib_msix_init(if_ctx_t ctx)
{
	device_t dev = ctx->ifc_dev;
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	int admincnt, bar, err, iflib_num_rx_queues, iflib_num_tx_queues;
	int msgs, queuemsgs, queues, rx_queues, tx_queues, vectors;

	iflib_num_tx_queues = ctx->ifc_sysctl_ntxqs;
	iflib_num_rx_queues = ctx->ifc_sysctl_nrxqs;

	if (bootverbose)
		device_printf(dev, "msix_init qsets capped at %d\n",
		    imax(scctx->isc_ntxqsets, scctx->isc_nrxqsets));

	/* Override by tuneable */
	if (scctx->isc_disable_msix)
		goto msi;

	/* First try MSI-X */
	if ((msgs = pci_msix_count(dev)) == 0) {
		if (bootverbose)
			device_printf(dev, "MSI-X not supported or disabled\n");
		goto msi;
	}

	bar = ctx->ifc_softc_ctx.isc_msix_bar;
	/*
	 * bar == -1 => "trust me I know what I'm doing"
	 * Some drivers are for hardware that is so shoddily
	 * documented that no one knows which bars are which
	 * so the developer has to map all bars. This hack
	 * allows shoddy garbage to use MSI-X in this framework.
	 */
	if (bar != -1) {
		ctx->ifc_msix_mem = bus_alloc_resource_any(dev,
		    SYS_RES_MEMORY, &bar, RF_ACTIVE);
		if (ctx->ifc_msix_mem == NULL) {
			device_printf(dev, "Unable to map MSI-X table\n");
			goto msi;
		}
	}

	admincnt = sctx->isc_admin_intrcnt;
#if IFLIB_DEBUG
	/* use only 1 qset in debug mode */
	queuemsgs = min(msgs - admincnt, 1);
#else
	queuemsgs = msgs - admincnt;
#endif
#ifdef RSS
	queues = imin(queuemsgs, rss_getnumbuckets());
#else
	queues = queuemsgs;
#endif
	queues = imin(CPU_COUNT(&ctx->ifc_cpus), queues);
	if (bootverbose)
		device_printf(dev,
		    "intr CPUs: %d queue msgs: %d admincnt: %d\n",
		    CPU_COUNT(&ctx->ifc_cpus), queuemsgs, admincnt);
#ifdef  RSS
	/* If we're doing RSS, clamp at the number of RSS buckets */
	if (queues > rss_getnumbuckets())
		queues = rss_getnumbuckets();
#endif
	if (iflib_num_rx_queues > 0 && iflib_num_rx_queues < queuemsgs - admincnt)
		rx_queues = iflib_num_rx_queues;
	else
		rx_queues = queues;

	if (rx_queues > scctx->isc_nrxqsets)
		rx_queues = scctx->isc_nrxqsets;

	/*
	 * We want this to be all logical CPUs by default
	 */
	if (iflib_num_tx_queues > 0 && iflib_num_tx_queues < queues)
		tx_queues = iflib_num_tx_queues;
	else
		tx_queues = mp_ncpus;

	if (tx_queues > scctx->isc_ntxqsets)
		tx_queues = scctx->isc_ntxqsets;

	if (ctx->ifc_sysctl_qs_eq_override == 0) {
#ifdef INVARIANTS
		if (tx_queues != rx_queues)
			device_printf(dev,
			    "queue equality override not set, capping rx_queues at %d and tx_queues at %d\n",
			    min(rx_queues, tx_queues), min(rx_queues, tx_queues));
#endif
		tx_queues = min(rx_queues, tx_queues);
		rx_queues = min(rx_queues, tx_queues);
	}

	vectors = rx_queues + admincnt;
	if (msgs < vectors) {
		device_printf(dev,
		    "insufficient number of MSI-X vectors "
		    "(supported %d, need %d)\n", msgs, vectors);
		goto msi;
	}

	device_printf(dev, "Using %d RX queues %d TX queues\n", rx_queues,
	    tx_queues);
	msgs = vectors;
	if ((err = pci_alloc_msix(dev, &vectors)) == 0) {
		if (vectors != msgs) {
			device_printf(dev,
			    "Unable to allocate sufficient MSI-X vectors "
			    "(got %d, need %d)\n", vectors, msgs);
			pci_release_msi(dev);
			if (bar != -1) {
				bus_release_resource(dev, SYS_RES_MEMORY, bar,
				    ctx->ifc_msix_mem);
				ctx->ifc_msix_mem = NULL;
			}
			goto msi;
		}
		device_printf(dev, "Using MSI-X interrupts with %d vectors\n",
		    vectors);
		scctx->isc_vectors = vectors;
		scctx->isc_nrxqsets = rx_queues;
		scctx->isc_ntxqsets = tx_queues;
		scctx->isc_intr = IFLIB_INTR_MSIX;

		return (vectors);
	} else {
		device_printf(dev,
		    "failed to allocate %d MSI-X vectors, err: %d\n", vectors,
		    err);
		if (bar != -1) {
			bus_release_resource(dev, SYS_RES_MEMORY, bar,
			    ctx->ifc_msix_mem);
			ctx->ifc_msix_mem = NULL;
		}
	}

msi:
	vectors = pci_msi_count(dev);
	scctx->isc_nrxqsets = 1;
	scctx->isc_ntxqsets = 1;
	scctx->isc_vectors = vectors;
	if (vectors == 1 && pci_alloc_msi(dev, &vectors) == 0) {
		device_printf(dev, "Using an MSI interrupt\n");
		scctx->isc_intr = IFLIB_INTR_MSI;
	} else {
		scctx->isc_vectors = 1;
		device_printf(dev, "Using a Legacy interrupt\n");
		scctx->isc_intr = IFLIB_INTR_LEGACY;
	}

	return (vectors);
}

static const char *ring_states[] = { "IDLE", "BUSY", "STALLED", "ABDICATED" };

static int
mp_ring_state_handler(SYSCTL_HANDLER_ARGS)
{
	int rc;
	uint16_t *state = ((uint16_t *)oidp->oid_arg1);
	struct sbuf *sb;
	const char *ring_state = "UNKNOWN";

	/* XXX needed ? */
	rc = sysctl_wire_old_buffer(req, 0);
	MPASS(rc == 0);
	if (rc != 0)
		return (rc);
	sb = sbuf_new_for_sysctl(NULL, NULL, 80, req);
	MPASS(sb != NULL);
	if (sb == NULL)
		return (ENOMEM);
	if (state[3] <= 3)
		ring_state = ring_states[state[3]];

	sbuf_printf(sb, "pidx_head: %04hd pidx_tail: %04hd cidx: %04hd state: %s",
		    state[0], state[1], state[2], ring_state);
	rc = sbuf_finish(sb);
	sbuf_delete(sb);
	return (rc);
}

enum iflib_ndesc_handler {
	IFLIB_NTXD_HANDLER,
	IFLIB_NRXD_HANDLER,
};

static int
mp_ndesc_handler(SYSCTL_HANDLER_ARGS)
{
	if_ctx_t ctx = (void *)arg1;
	enum iflib_ndesc_handler type = arg2;
	char buf[256] = {0};
	qidx_t *ndesc;
	char *p, *next;
	int nqs, rc, i;

	nqs = 8;
	switch (type) {
	case IFLIB_NTXD_HANDLER:
		ndesc = ctx->ifc_sysctl_ntxds;
		if (ctx->ifc_sctx)
			nqs = ctx->ifc_sctx->isc_ntxqs;
		break;
	case IFLIB_NRXD_HANDLER:
		ndesc = ctx->ifc_sysctl_nrxds;
		if (ctx->ifc_sctx)
			nqs = ctx->ifc_sctx->isc_nrxqs;
		break;
	default:
		printf("%s: unhandled type\n", __func__);
		return (EINVAL);
	}
	if (nqs == 0)
		nqs = 8;

	for (i = 0; i < 8; i++) {
		if (i >= nqs)
			break;
		if (i)
			strcat(buf, ",");
		sprintf(strchr(buf, 0), "%d", ndesc[i]);
	}

	rc = sysctl_handle_string(oidp, buf, sizeof(buf), req);
	if (rc || req->newptr == NULL)
		return (rc);

	for (i = 0, next = buf, p = strsep(&next, " ,"); i < 8 && p;
	    i++, p = strsep(&next, " ,")) {
		ndesc[i] = strtoul(p, NULL, 10);
	}

	return (rc);
}

static int
iflib_handle_tx_reclaim_thresh(SYSCTL_HANDLER_ARGS)
{
	if_ctx_t ctx = (void *)arg1;
	iflib_txq_t txq;
	int i, err;
	int thresh;

	thresh = ctx->ifc_sysctl_tx_reclaim_thresh;
	err = sysctl_handle_int(oidp, &thresh, arg2, req);
	if (err != 0) {
		return err;
	}

	if (thresh == ctx->ifc_sysctl_tx_reclaim_thresh)
		return 0;

	if (thresh > ctx->ifc_softc_ctx.isc_ntxd[0] / 2) {
		device_printf(ctx->ifc_dev, "TX Reclaim thresh must be <= %d\n",
		    ctx->ifc_softc_ctx.isc_ntxd[0] / 2);
		return (EINVAL);
	}

	ctx->ifc_sysctl_tx_reclaim_thresh = thresh;
	if (ctx->ifc_txqs == NULL)
		return (err);

	txq = &ctx->ifc_txqs[0];
	for (i = 0; i < NTXQSETS(ctx); i++, txq++) {
		txq->ift_reclaim_thresh = thresh;
	}
	return (err);
}

static int
iflib_handle_tx_reclaim_ticks(SYSCTL_HANDLER_ARGS)
{
	if_ctx_t ctx = (void *)arg1;
	iflib_txq_t txq;
	int i, err;
	int ticks;

	ticks = ctx->ifc_sysctl_tx_reclaim_ticks;
	err = sysctl_handle_int(oidp, &ticks, arg2, req);
	if (err != 0) {
		return err;
	}

	if (ticks == ctx->ifc_sysctl_tx_reclaim_ticks)
		return 0;

	if (ticks > hz) {
		device_printf(ctx->ifc_dev,
		    "TX Reclaim ticks must be <= hz (%d)\n", hz);
		return (EINVAL);
	}

	ctx->ifc_sysctl_tx_reclaim_ticks = ticks;
	if (ctx->ifc_txqs == NULL)
		return (err);

	txq = &ctx->ifc_txqs[0];
	for (i = 0; i < NTXQSETS(ctx); i++, txq++) {
		txq->ift_reclaim_ticks = ticks;
	}
	return (err);
}

static int
iflib_handle_tx_defer_mfree(SYSCTL_HANDLER_ARGS)
{
	if_ctx_t ctx = (void *)arg1;
	iflib_txq_t txq;
	int i, err;
	int defer;

	defer = ctx->ifc_sysctl_tx_defer_mfree;
	err = sysctl_handle_int(oidp, &defer, arg2, req);
	if (err != 0) {
		return err;
	}

	if (defer == ctx->ifc_sysctl_tx_defer_mfree)
		return 0;

	ctx->ifc_sysctl_tx_defer_mfree = defer;
	if (ctx->ifc_txqs == NULL)
		return (err);

	txq = &ctx->ifc_txqs[0];
	for (i = 0; i < NTXQSETS(ctx); i++, txq++) {
		txq->ift_defer_mfree = defer;
	}
	return (err);
}

#define NAME_BUFLEN 32
static void
iflib_add_device_sysctl_pre(if_ctx_t ctx)
{
	device_t dev = iflib_get_dev(ctx);
	struct sysctl_oid_list *child, *oid_list;
	struct sysctl_oid *node;

	sysctl_ctx_init(&ctx->ifc_sysctl_ctx);
	child = SYSCTL_CHILDREN(device_get_sysctl_tree(dev));
	ctx->ifc_sysctl_node = node = SYSCTL_ADD_NODE(&ctx->ifc_sysctl_ctx, child,
	    OID_AUTO, "iflib", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
	    "IFLIB fields");
	oid_list = SYSCTL_CHILDREN(node);

	SYSCTL_ADD_CONST_STRING(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "driver_version",
	    CTLFLAG_RD, ctx->ifc_sctx->isc_driver_version, "driver version");
	SYSCTL_ADD_U32(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO,
	    "tx_watchdog_events", CTLFLAG_RD, &ctx->ifc_tx_watchdog_events, 0,
	    "TX watchdog resets initiated by iflib");

	SYSCTL_ADD_BOOL(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "simple_tx",
	    CTLFLAG_RDTUN, &ctx->ifc_sysctl_simple_tx, 0,
	    "use simple tx ring");
	SYSCTL_ADD_U16(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "override_ntxqs",
	    CTLFLAG_RWTUN, &ctx->ifc_sysctl_ntxqs, 0,
	    "# of txqs to use, 0 => use default #");
	SYSCTL_ADD_U16(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "override_nrxqs",
	    CTLFLAG_RWTUN, &ctx->ifc_sysctl_nrxqs, 0,
	    "# of rxqs to use, 0 => use default #");
	SYSCTL_ADD_U16(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "override_qs_enable",
	    CTLFLAG_RWTUN, &ctx->ifc_sysctl_qs_eq_override, 0,
	    "permit #txq != #rxq");
	SYSCTL_ADD_INT(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "disable_msix",
	    CTLFLAG_RWTUN, &ctx->ifc_softc_ctx.isc_disable_msix, 0,
	    "disable MSI-X (default 0)");
	SYSCTL_ADD_U16(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "rx_budget",
	    CTLFLAG_RWTUN, &ctx->ifc_sysctl_rx_budget, 0, "set the RX budget");
	SYSCTL_ADD_U16(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "tx_abdicate",
	    CTLFLAG_RWTUN, &ctx->ifc_sysctl_tx_abdicate, 0,
	    "cause TX to abdicate instead of running to completion");
	ctx->ifc_sysctl_core_offset = CORE_OFFSET_UNSPECIFIED;
	SYSCTL_ADD_U16(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "core_offset",
	    CTLFLAG_RDTUN, &ctx->ifc_sysctl_core_offset, 0,
	    "offset to start using cores at");
	SYSCTL_ADD_U8(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "separate_txrx",
	    CTLFLAG_RDTUN, &ctx->ifc_sysctl_separate_txrx, 0,
	    "use separate cores for TX and RX");
	SYSCTL_ADD_U8(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "use_logical_cores",
	    CTLFLAG_RDTUN, &ctx->ifc_sysctl_use_logical_cores, 0,
	    "try to make use of logical cores for TX and RX");
	SYSCTL_ADD_U16(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "use_extra_msix_vectors",
	    CTLFLAG_RDTUN, &ctx->ifc_sysctl_extra_msix_vectors, 0,
	    "attempt to reserve the given number of extra MSI-X vectors during driver load for the creation of additional interfaces later");
	SYSCTL_ADD_INT(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "allocated_msix_vectors",
	    CTLFLAG_RDTUN, &ctx->ifc_softc_ctx.isc_vectors, 0,
	    "total # of MSI-X vectors allocated by driver");

	/* XXX change for per-queue sizes */
	SYSCTL_ADD_PROC(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "override_ntxds",
	    CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, ctx,
	    IFLIB_NTXD_HANDLER, mp_ndesc_handler, "A",
	    "list of # of TX descriptors to use, 0 = use default #");
	SYSCTL_ADD_PROC(&ctx->ifc_sysctl_ctx, oid_list, OID_AUTO, "override_nrxds",
	    CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, ctx,
	    IFLIB_NRXD_HANDLER, mp_ndesc_handler, "A",
	    "list of # of RX descriptors to use, 0 = use default #");
}

static void
iflib_add_device_sysctl_post(if_ctx_t ctx)
{
	if_shared_ctx_t sctx = ctx->ifc_sctx;
	if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
	struct sysctl_oid_list *child;
	struct sysctl_ctx_list *ctx_list = &ctx->ifc_sysctl_ctx;
	iflib_fl_t fl;
	iflib_txq_t txq;
	iflib_rxq_t rxq;
	int i, j;
	char namebuf[NAME_BUFLEN];
	char *qfmt;
	struct sysctl_oid *queue_node, *fl_node, *node;
	struct sysctl_oid_list *queue_list, *fl_list;

	node = ctx->ifc_sysctl_node;
	child = SYSCTL_CHILDREN(node);

       SYSCTL_ADD_PROC(ctx_list, child, OID_AUTO, "tx_reclaim_thresh",
           CTLTYPE_INT | CTLFLAG_RWTUN, ctx,
           0, iflib_handle_tx_reclaim_thresh, "I",
           "Number of TX descs outstanding before reclaim is called");

       SYSCTL_ADD_PROC(ctx_list, child, OID_AUTO, "tx_reclaim_ticks",
           CTLTYPE_INT | CTLFLAG_RWTUN, ctx,
           0, iflib_handle_tx_reclaim_ticks, "I",
           "Number of ticks before a TX reclaim is forced");

       SYSCTL_ADD_PROC(ctx_list, child, OID_AUTO, "tx_defer_mfree",
           CTLTYPE_INT | CTLFLAG_RWTUN, ctx,
           0, iflib_handle_tx_defer_mfree, "I",
           "Free completed transmits outside of TX ring lock");

	if (scctx->isc_ntxqsets > 100)
		qfmt = "txq%03d";
	else if (scctx->isc_ntxqsets > 10)
		qfmt = "txq%02d";
	else
		qfmt = "txq%d";
	for (i = 0, txq = ctx->ifc_txqs; i < scctx->isc_ntxqsets; i++, txq++) {
		snprintf(namebuf, NAME_BUFLEN, qfmt, i);
		queue_node = SYSCTL_ADD_NODE(ctx_list, child, OID_AUTO, namebuf,
		    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "Queue Name");
		queue_list = SYSCTL_CHILDREN(queue_node);
		SYSCTL_ADD_INT(ctx_list, queue_list, OID_AUTO, "cpu",
		    CTLFLAG_RD, &txq->ift_task.gt_cpu, 0,
		    "cpu this queue is bound to");
#if MEMORY_LOGGING
		SYSCTL_ADD_UQUAD(ctx_list, queue_list, OID_AUTO, "txq_dequeued",
		    CTLFLAG_RD, &txq->ift_dequeued, "total mbufs freed");
		SYSCTL_ADD_UQUAD(ctx_list, queue_list, OID_AUTO, "txq_enqueued",
		    CTLFLAG_RD, &txq->ift_enqueued, "total mbufs enqueued");
#endif
		SYSCTL_ADD_UQUAD(ctx_list, queue_list, OID_AUTO, "mbuf_defrag",
		    CTLFLAG_RD, &txq->ift_mbuf_defrag,
		    "# of times m_defrag was called");
		SYSCTL_ADD_UQUAD(ctx_list, queue_list, OID_AUTO, "m_pullups",
		    CTLFLAG_RD, &txq->ift_pullups,
		    "# of times m_pullup was called");
		SYSCTL_ADD_UQUAD(ctx_list, queue_list, OID_AUTO,
		    "mbuf_defrag_failed", CTLFLAG_RD,
		    &txq->ift_mbuf_defrag_failed, "# of times m_defrag failed");
		SYSCTL_ADD_UQUAD(ctx_list, queue_list, OID_AUTO,
		    "no_desc_avail", CTLFLAG_RD, &txq->ift_no_desc_avail,
		    "# of times no descriptors were available");
		SYSCTL_ADD_UQUAD(ctx_list, queue_list, OID_AUTO,
		    "tx_map_failed", CTLFLAG_RD, &txq->ift_map_failed,
		    "# of times DMA map failed");
		SYSCTL_ADD_UQUAD(ctx_list, queue_list, OID_AUTO,
		    "txd_encap_efbig", CTLFLAG_RD, &txq->ift_txd_encap_efbig,
		    "# of times txd_encap returned EFBIG");
		SYSCTL_ADD_UQUAD(ctx_list, queue_list, OID_AUTO,
		    "no_tx_dma_setup", CTLFLAG_RD, &txq->ift_no_tx_dma_setup,
		    "# of times map failed for other than EFBIG");
		SYSCTL_ADD_U16(ctx_list, queue_list, OID_AUTO, "txq_pidx",
		    CTLFLAG_RD, &txq->ift_pidx, 1, "Producer Index");
		SYSCTL_ADD_U16(ctx_list, queue_list, OID_AUTO, "txq_cidx",
		    CTLFLAG_RD, &txq->ift_cidx, 1, "Consumer Index");
		SYSCTL_ADD_U16(ctx_list, queue_list, OID_AUTO,
		    "txq_cidx_processed", CTLFLAG_RD, &txq->ift_cidx_processed,
		    1, "Consumer Index seen by credit update");
		SYSCTL_ADD_U16(ctx_list, queue_list, OID_AUTO, "txq_in_use",
		    CTLFLAG_RD, &txq->ift_in_use, 1, "descriptors in use");
		SYSCTL_ADD_UQUAD(ctx_list, queue_list, OID_AUTO,
		    "txq_processed", CTLFLAG_RD, &txq->ift_processed,
		    "descriptors procesed for clean");
		SYSCTL_ADD_UQUAD(ctx_list, queue_list, OID_AUTO, "txq_cleaned",
		    CTLFLAG_RD, &txq->ift_cleaned, "total cleaned");
		SYSCTL_ADD_PROC(ctx_list, queue_list, OID_AUTO, "ring_state",
		    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
		    __DEVOLATILE(uint64_t *, &txq->ift_br->state), 0,
		    mp_ring_state_handler, "A", "soft ring state");
		SYSCTL_ADD_COUNTER_U64(ctx_list, queue_list, OID_AUTO,
		    "r_enqueues", CTLFLAG_RD, &txq->ift_br->enqueues,
		    "# of enqueues to the mp_ring for this queue");
		SYSCTL_ADD_COUNTER_U64(ctx_list, queue_list, OID_AUTO,
		    "r_drops", CTLFLAG_RD, &txq->ift_br->drops,
		    "# of drops in the mp_ring for this queue");
		SYSCTL_ADD_COUNTER_U64(ctx_list, queue_list, OID_AUTO,
		    "r_starts", CTLFLAG_RD, &txq->ift_br->starts,
		    "# of normal consumer starts in mp_ring for this queue");
		SYSCTL_ADD_COUNTER_U64(ctx_list, queue_list, OID_AUTO,
		    "r_stalls", CTLFLAG_RD, &txq->ift_br->stalls,
		    "# of consumer stalls in the mp_ring for this queue");
		SYSCTL_ADD_COUNTER_U64(ctx_list, queue_list, OID_AUTO,
		    "r_restarts", CTLFLAG_RD, &txq->ift_br->restarts,
		    "# of consumer restarts in the mp_ring for this queue");
		SYSCTL_ADD_COUNTER_U64(ctx_list, queue_list, OID_AUTO,
		    "r_abdications", CTLFLAG_RD, &txq->ift_br->abdications,
		    "# of consumer abdications in the mp_ring for this queue");
		if (txq->ift_drbr == NULL)
			continue;
		SYSCTL_ADD_UQUAD(ctx_list, queue_list, OID_AUTO,
		    "drbr_direct", CTLFLAG_RD, &txq->ift_drbr_direct,
		    "# of packets sent without touching the deferral ring");
		SYSCTL_ADD_UQUAD(ctx_list, queue_list, OID_AUTO,
		    "drbr_stall", CTLFLAG_RD, &txq->ift_drbr_stall,
		    "# of times the drain stopped with no descriptors free");
		SYSCTL_ADD_COUNTER_U64(ctx_list, queue_list, OID_AUTO,
		    "drbr_deferred", CTLFLAG_RD, &txq->ift_drbr_deferred,
		    "# of packets deferred after losing the tx trylock");
		SYSCTL_ADD_COUNTER_U64(ctx_list, queue_list, OID_AUTO,
		    "drbr_drops", CTLFLAG_RD, &txq->ift_drbr_drops,
		    "# of packets dropped because the deferral ring was full");
		SYSCTL_ADD_COUNTER_U64(ctx_list, queue_list, OID_AUTO,
		    "drbr_blocked", CTLFLAG_RD, &txq->ift_drbr_blocked,
		    "# of times a full deferral ring forced a tx lock wait");
		SYSCTL_ADD_COUNTER_U64(ctx_list, queue_list, OID_AUTO,
		    "drbr_remote", CTLFLAG_RD, &txq->ift_drbr_remote,
		    "# of times a different llc or producer limit forced a tx "
		    "lock wait");
	}

	if (scctx->isc_nrxqsets > 100)
		qfmt = "rxq%03d";
	else if (scctx->isc_nrxqsets > 10)
		qfmt = "rxq%02d";
	else
		qfmt = "rxq%d";
	for (i = 0, rxq = ctx->ifc_rxqs; i < scctx->isc_nrxqsets; i++, rxq++) {
		snprintf(namebuf, NAME_BUFLEN, qfmt, i);
		queue_node = SYSCTL_ADD_NODE(ctx_list, child, OID_AUTO, namebuf,
		    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "Queue Name");
		queue_list = SYSCTL_CHILDREN(queue_node);
		SYSCTL_ADD_INT(ctx_list, queue_list, OID_AUTO, "cpu",
		    CTLFLAG_RD, &rxq->ifr_task.gt_cpu, 0,
		    "cpu this queue is bound to");
		if (sctx->isc_flags & IFLIB_HAS_RXCQ) {
			SYSCTL_ADD_U16(ctx_list, queue_list, OID_AUTO,
			    "rxq_cq_cidx", CTLFLAG_RD, &rxq->ifr_cq_cidx, 1,
			    "Consumer Index");
		}

		for (j = 0, fl = rxq->ifr_fl; j < rxq->ifr_nfl; j++, fl++) {
			snprintf(namebuf, NAME_BUFLEN, "rxq_fl%d", j);
			fl_node = SYSCTL_ADD_NODE(ctx_list, queue_list,
			    OID_AUTO, namebuf, CTLFLAG_RD | CTLFLAG_MPSAFE,
			    NULL, "freelist Name");
			fl_list = SYSCTL_CHILDREN(fl_node);
			SYSCTL_ADD_U16(ctx_list, fl_list, OID_AUTO, "pidx",
			    CTLFLAG_RD, &fl->ifl_pidx, 1, "Producer Index");
			SYSCTL_ADD_U16(ctx_list, fl_list, OID_AUTO, "cidx",
			    CTLFLAG_RD, &fl->ifl_cidx, 1, "Consumer Index");
			SYSCTL_ADD_U16(ctx_list, fl_list, OID_AUTO, "credits",
			    CTLFLAG_RD, &fl->ifl_credits, 1,
			    "credits available");
			SYSCTL_ADD_U16(ctx_list, fl_list, OID_AUTO, "buf_size",
			    CTLFLAG_RD, &fl->ifl_buf_size, 1, "buffer size");
#if MEMORY_LOGGING
			SYSCTL_ADD_UQUAD(ctx_list, fl_list, OID_AUTO,
			    "fl_m_enqueued", CTLFLAG_RD, &fl->ifl_m_enqueued,
			    "mbufs allocated");
			SYSCTL_ADD_UQUAD(ctx_list, fl_list, OID_AUTO,
			    "fl_m_dequeued", CTLFLAG_RD, &fl->ifl_m_dequeued,
			    "mbufs freed");
			SYSCTL_ADD_UQUAD(ctx_list, fl_list, OID_AUTO,
			    "fl_cl_enqueued", CTLFLAG_RD, &fl->ifl_cl_enqueued,
			    "clusters allocated");
			SYSCTL_ADD_UQUAD(ctx_list, fl_list, OID_AUTO,
			    "fl_cl_dequeued", CTLFLAG_RD, &fl->ifl_cl_dequeued,
			    "clusters freed");
#endif
		}
	}

}

void
iflib_request_reset(if_ctx_t ctx)
{

	STATE_LOCK(ctx);
	ctx->ifc_flags |= IFC_DO_RESET;
	STATE_UNLOCK(ctx);
}

void
iflib_request_reset_if_up(if_ctx_t ctx)
{

	STATE_LOCK(ctx);
	ctx->ifc_flags |= IFC_DO_RESET_IF_UP;
	STATE_UNLOCK(ctx);
}

void
iflib_init_failed(if_ctx_t ctx)
{

	sx_assert(&ctx->ifc_ctx_sx, SA_XLOCKED);
	KASSERT(ctx->ifc_datapath_state == IFLIB_DP_STARTING,
	    ("iflib_init_failed outside IFDI_INIT, state %d",
	    ctx->ifc_datapath_state));
	STATE_LOCK(ctx);
	ctx->ifc_flags |= IFC_INIT_FAILED;
	STATE_UNLOCK(ctx);
}

#ifndef __NO_STRICT_ALIGNMENT
static struct mbuf *
iflib_fixup_rx(struct mbuf *m)
{
	struct mbuf *n;

	if (m->m_len <= (MCLBYTES - ETHER_HDR_LEN)) {
		bcopy(m->m_data, m->m_data + ETHER_HDR_LEN, m->m_len);
		m->m_data += ETHER_HDR_LEN;
		n = m;
	} else {
		MGETHDR(n, M_NOWAIT, MT_DATA);
		if (n == NULL) {
			m_freem(m);
			return (NULL);
		}
		bcopy(m->m_data, n->m_data, ETHER_HDR_LEN);
		m->m_data += ETHER_HDR_LEN;
		m->m_len -= ETHER_HDR_LEN;
		n->m_len = ETHER_HDR_LEN;
		M_MOVE_PKTHDR(n, m);
		n->m_next = m;
	}
	return (n);
}
#endif

#ifdef DEBUGNET
static void
iflib_debugnet_init(if_t ifp, int *nrxr, int *ncl, int *clsize)
{
	if_ctx_t ctx;

	ctx = if_getsoftc(ifp);
	CTX_LOCK(ctx);
	*nrxr = NRXQSETS(ctx);
	*ncl = ctx->ifc_rxqs[0].ifr_fl->ifl_size;
	*clsize = ctx->ifc_rxqs[0].ifr_fl->ifl_buf_size;
	CTX_UNLOCK(ctx);
}

static void
iflib_debugnet_event(if_t ifp, enum debugnet_ev event)
{
	if_ctx_t ctx;
	if_softc_ctx_t scctx;
	iflib_fl_t fl;
	iflib_rxq_t rxq;
	int i, j;

	ctx = if_getsoftc(ifp);
	scctx = &ctx->ifc_softc_ctx;

	switch (event) {
	case DEBUGNET_START:
		for (i = 0; i < scctx->isc_nrxqsets; i++) {
			rxq = &ctx->ifc_rxqs[i];
			for (j = 0; j < rxq->ifr_nfl; j++) {
				fl = rxq->ifr_fl;
				fl->ifl_zone = m_getzone(fl->ifl_buf_size);
			}
		}
		iflib_no_tx_batch = 1;
		break;
	default:
		break;
	}
}

static int
iflib_debugnet_transmit(if_t ifp, struct mbuf *m)
{
	if_ctx_t ctx;
	iflib_txq_t txq;
	int error;
	int bytes_sent = 0;
	int pkt_sent = 0;

	ctx = if_getsoftc(ifp);
	if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
	    IFF_DRV_RUNNING)
		return (EBUSY);

	txq = &ctx->ifc_txqs[0];
	error = iflib_encap(txq, &m, &bytes_sent, &pkt_sent);
	if (error == 0)
		(void)iflib_txd_db_check(txq, true);
	return (error);
}

static int
iflib_debugnet_poll(if_t ifp, int count)
{
	struct epoch_tracker et;
	if_ctx_t ctx;
	if_softc_ctx_t scctx;
	iflib_txq_t txq;
	int i;

	ctx = if_getsoftc(ifp);
	scctx = &ctx->ifc_softc_ctx;

	if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
	    IFF_DRV_RUNNING)
		return (EBUSY);

	txq = &ctx->ifc_txqs[0];
	(void)iflib_completed_tx_reclaim(txq, NULL);

	NET_EPOCH_ENTER(et);
	for (i = 0; i < scctx->isc_nrxqsets; i++)
		(void)iflib_rxeof(&ctx->ifc_rxqs[i], 16 /* XXX */);
	NET_EPOCH_EXIT(et);
	return (0);
}
#endif /* DEBUGNET */

static inline iflib_txq_t
iflib_simple_select_queue(if_ctx_t ctx, struct mbuf *m)
{
	int qidx;

#ifdef ALTQ
	/* ALTQ-enabled interfaces always use queue 0. */
	if (if_altq_is_enabled(ctx->ifc_ifp))
		return (&ctx->ifc_txqs[0]);
#endif
	if ((NTXQSETS(ctx) > 1) && M_HASHTYPE_GET(m))
		qidx = QIDX(ctx, m);
	else
		qidx = NTXQSETS(ctx) + FIRST_QSET(ctx) - 1;
	return (&ctx->ifc_txqs[qidx]);
}

enum iflib_txq_producer_status {
	IFLIB_TXQ_PRODUCER_ENTERED,
	IFLIB_TXQ_PRODUCER_QUIESCING,
	IFLIB_TXQ_PRODUCER_REMOTE,
};

/*
 * Keep the most recent producer llc when the count reaches zero.  Producers
 * in that llc can use fetchadd without contending on a compare-and-swap.
 * Another llc can take ownership only while the producer count is zero.
 */
static __inline enum iflib_txq_producer_status
iflib_txq_producer_enter(iflib_txq_t txq, bool *pinned)
{
	u_int count, llc_id, max_producers, newstate, old, state;

	if (!iflib_producer_gate) {
		state = atomic_fetchadd_int(&txq->ift_producers, 1);
		if (__predict_false((state & IFLIB_TXQ_QUIESCING) != 0)) {
			atomic_subtract_int(&txq->ift_producers, 1);
			return (IFLIB_TXQ_PRODUCER_QUIESCING);
		}
		*pinned = false;
		return (IFLIB_TXQ_PRODUCER_ENTERED);
	}

	max_producers = iflib_max_producers;
	if (iflib_single_llc) {
		state = atomic_fetchadd_int(&txq->ift_producers, 1);
		if (__predict_false((state & IFLIB_TXQ_QUIESCING) != 0)) {
			atomic_subtract_int(&txq->ift_producers, 1);
			return (IFLIB_TXQ_PRODUCER_QUIESCING);
		}
		count = IFLIB_TXQ_PRODUCER(state);
		if (count >= max_producers ||
		    count == IFLIB_TXQ_PRODUCER_MAX) {
			atomic_subtract_int(&txq->ift_producers, 1);
			return (IFLIB_TXQ_PRODUCER_REMOTE);
		}
		*pinned = false;
		return (IFLIB_TXQ_PRODUCER_ENTERED);
	}

	sched_pin();
	llc_id = iflib_cpu_llc[curcpu];
	state = atomic_load_acq_int(&txq->ift_producers);
	for (;;) {
		if ((state & IFLIB_TXQ_QUIESCING) != 0) {
			sched_unpin();
			return (IFLIB_TXQ_PRODUCER_QUIESCING);
		}

		count = IFLIB_TXQ_PRODUCER(state);
		if (count >= max_producers ||
		    count == IFLIB_TXQ_PRODUCER_MAX) {
			sched_unpin();
			return (IFLIB_TXQ_PRODUCER_REMOTE);
		}
		if (IFLIB_TXQ_PRODUCER_LLC(state) == llc_id) {
			/*
			 * The llc can change between the load and fetchadd only
			 * if the count was zero.  Validate the returned
			 * state and undo the increment if ownership changed.
			 */
			old = atomic_fetchadd_int(&txq->ift_producers, 1);
			if ((old & IFLIB_TXQ_QUIESCING) != 0) {
				atomic_subtract_int(&txq->ift_producers, 1);
				sched_unpin();
				return (IFLIB_TXQ_PRODUCER_QUIESCING);
			}
			count = IFLIB_TXQ_PRODUCER(old);
			if (IFLIB_TXQ_PRODUCER_LLC(old) == llc_id &&
			    count < max_producers &&
			    count != IFLIB_TXQ_PRODUCER_MAX) {
				*pinned = true;
				return (IFLIB_TXQ_PRODUCER_ENTERED);
			}

			atomic_subtract_int(&txq->ift_producers, 1);
			sched_unpin();
			return (IFLIB_TXQ_PRODUCER_REMOTE);
		}

		if (count != 0) {
			sched_unpin();
			return (IFLIB_TXQ_PRODUCER_REMOTE);
		}

		newstate = llc_id << IFLIB_TXQ_PRODUCER_LLC_SHIFT;
		newstate |= 1;
		if (atomic_fcmpset_acq_int(&txq->ift_producers, &state,
		    newstate)) {
			*pinned = true;
			return (IFLIB_TXQ_PRODUCER_ENTERED);
		}
	}
}

static __inline void
iflib_txq_producer_exit(iflib_txq_t txq, bool pinned)
{
	u_int state __diagused;

	if (!pinned) {
		atomic_subtract_rel_int(&txq->ift_producers, 1);
		return;
	}

	atomic_thread_fence_rel();
	state = atomic_fetchadd_int(&txq->ift_producers, -1);
	KASSERT(IFLIB_TXQ_PRODUCER(state) != 0,
	    ("%s: producer count underflow", __func__));
	KASSERT(IFLIB_TXQ_PRODUCER_LLC(state) == iflib_cpu_llc[curcpu],
	    ("%s: producer llc changed", __func__));
	sched_unpin();
}

/* Consumes the mbuf in all cases */
static int
iflib_simple_encap(iflib_txq_t txq, struct mbuf *m, int *bytes, int *pkts,
    int *mcasts)
{
	if_t ifp;
	int error;

	mtx_assert(&txq->ift_mtx, MA_OWNED);
	ifp = txq->ift_ctx->ifc_ifp;

	error = iflib_encap(txq, &m, bytes, pkts);
	if (__predict_false(error != 0)) {
		/* iflib_encap() always frees the mbuf on failures */
		if (error == ENOBUFS)
			if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
		else
			if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
		return (error);
	}
	*mcasts += !!(m->m_flags & M_MCAST);
	DBG_COUNTER_INC(tx_sent);
	ETHER_BPF_MTAP(ifp, m);
	(void)iflib_txd_db_check(txq, false);
	return (0);
}

/* Drain the deferral ring into the hardware. */
static void
iflib_simple_drbr_drain(iflib_txq_t txq, u_int quota, int *bytes, int *pkts,
    int *mcasts)
{
	if_ctx_t ctx;
	struct mbuf *m;
	if_t ifp;
	u_int i;

	mtx_assert(&txq->ift_mtx, MA_OWNED);
	ctx = txq->ift_ctx;
	ifp = ctx->ifc_ifp;
	if (__predict_false(!(if_getdrvflags(ifp) & IFF_DRV_RUNNING) ||
	    !LINK_ACTIVE(ctx)))
		return;

#ifdef ALTQ
	 /* We only drain from txq0 when altq is enabled. */
	if (__predict_false(if_altq_is_enabled(ifp) && txq->ift_id != 0))
		return;
#endif
	for (i = 0; TXQ_AVAIL(txq) >= MAX_TX_DESC(ctx); i++) {
		if (i == quota)
			return;
		m = drbr_dequeue(ifp, txq->ift_drbr);
		if (m == NULL)
			return;
		(void)iflib_simple_encap(txq, m, bytes, pkts, mcasts);
	}
	if (!drbr_empty(ifp, txq->ift_drbr)) {
		txq->ift_drbr_stall++;
		if (quota != iflib_simple_drain_quota &&
		    (txq->ift_task.gt_task.ta_flags & TASK_ENQUEUED) == 0)
			GROUPTASK_ENQUEUE(&txq->ift_task);
	}
}

/*
 * Reclaim completed descriptors and push out anything that was deferred while
 * the tx lock was held.  Called from tx completion and from the timer.
 * A thread already holding the lock is draining, and will re-arm us if it
 * cannot finish, so never wait for it here.
 */
static void
iflib_simple_txq_drain(iflib_txq_t txq)
{
	if_t ifp;
	int bytes_sent = 0, pkt_sent = 0, mcast_sent = 0;

	ifp = txq->ift_ctx->ifc_ifp;

	if (!mtx_trylock(&txq->ift_mtx))
		return;

	if ((atomic_load_acq_int(&txq->ift_producers) & IFLIB_TXQ_QUIESCING)
	    != 0) {
		mtx_unlock(&txq->ift_mtx);
		return;
	}

	(void)iflib_completed_tx_reclaim(txq, NULL);
	if (!drbr_empty(ifp, txq->ift_drbr))
		iflib_simple_drbr_drain(txq, iflib_simple_drain_quota,
		    &bytes_sent, &pkt_sent, &mcast_sent);
	if (txq->ift_db_pending != 0)
		(void)iflib_txd_db_check(txq, true);
	mtx_unlock(&txq->ift_mtx);

	if_inc_counter(ifp, IFCOUNTER_OBYTES, bytes_sent);
	if_inc_counter(ifp, IFCOUNTER_OPACKETS, pkt_sent);
	if (mcast_sent)
		if_inc_counter(ifp, IFCOUNTER_OMCASTS, mcast_sent);
}

/*
 * When nothing is queued ahead of us there is no ordering constraint,
 * so the mbuf goes straight to the hardware and the deferral ring is
 * never touched.
 */
static int
iflib_simple_transmit_locked(iflib_txq_t txq, struct mbuf *m, int *bytes,
    int *pkts, int *mcasts)
{
	if_ctx_t ctx;
	if_t ifp;
	int error;

	mtx_assert(&txq->ift_mtx, MA_OWNED);
	ctx = txq->ift_ctx;
	ifp = ctx->ifc_ifp;

	if (__predict_true(!drbr_needs_enqueue(ifp, txq->ift_drbr) &&
	    TXQ_AVAIL(txq) >= MAX_TX_DESC(ctx))) {
		txq->ift_drbr_direct++;
		error = iflib_simple_encap(txq, m, bytes, pkts, mcasts);
	} else {
		error = buf_ring_enqueue(txq->ift_drbr, m);
		if (__predict_false(error != 0)) {
			m_freem(m);
			DBG_COUNTER_INC(tx_frees);
			counter_u64_add(txq->ift_drbr_drops, 1);
			if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
		}
	}

	/*
	 * Other transmitters may have deferred to the ring while we were in
	 * iflib_encap(), so always check again before dropping the lock.  We
	 * are the only thread that can drain it.
	 */
	if (!drbr_empty(ifp, txq->ift_drbr))
		iflib_simple_drbr_drain(txq, iflib_simple_drain_quota_thread,
		    bytes, pkts, mcasts);
	return (error);
}

static int
iflib_simple_transmit(if_t ifp, struct mbuf *m)
{
	if_ctx_t ctx;
	iflib_txq_t txq;
	struct mbuf **m_defer;
	enum iflib_txq_producer_status producer_status;
	bool pinned;
	int error, i, reclaimable;
	int bytes_sent = 0, pkt_sent = 0, mcast_sent = 0;

	ctx = if_getsoftc(ifp);
	if (__predict_false((if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0
		|| !LINK_ACTIVE(ctx)))
		goto net_down;

	txq = iflib_simple_select_queue(ctx, m);
	/*
	 * Avoid blocking behind another transmitter; the ring is drained by
	 * whoever holds ift_mtx, by tx completion, or by the watchdog timer.
	 */
	if (__predict_false(!mtx_trylock(&txq->ift_mtx))) {
		producer_status = iflib_txq_producer_enter(txq, &pinned);
		if (producer_status == IFLIB_TXQ_PRODUCER_QUIESCING)
			goto net_down;

		if (producer_status == IFLIB_TXQ_PRODUCER_ENTERED) {
			error = buf_ring_enqueue(txq->ift_drbr, m);
			iflib_txq_producer_exit(txq, pinned);
			if (__predict_true(error == 0)) {
				counter_u64_add(txq->ift_drbr_deferred, 1);
				return (0);
			}
			counter_u64_add(txq->ift_drbr_blocked, 1);
		} else {
			counter_u64_add(txq->ift_drbr_remote, 1);
		}
		mtx_lock(&txq->ift_mtx);
	}

	if (__predict_false(atomic_load_acq_int(&txq->ift_producers) &
	    IFLIB_TXQ_QUIESCING)) {
		mtx_unlock(&txq->ift_mtx);
		goto net_down;
	}

	error = iflib_simple_transmit_locked(txq, m, &bytes_sent, &pkt_sent,
	    &mcast_sent);
	if (txq->ift_db_pending != 0)
		(void)iflib_txd_db_check(txq, true);
	m_defer = NULL;
	reclaimable = iflib_txq_can_reclaim(txq);
	if (reclaimable != 0) {
		/*
		 * Try to set m_defer to the deferred mbuf reclaim array.  If
		 * we can, the frees will happen outside the tx lock.  If we
		 * can't, it means another thread is still proccessing frees.
		 */
		if (txq->ift_defer_mfree &&
		    atomic_cmpset_acq_ptr((uintptr_t *)&txq->ift_sds.ifsd_m_defer,
			(uintptr_t )txq->ift_sds.ifsd_m_deferb, 0)) {
			m_defer = txq->ift_sds.ifsd_m_deferb;
		}
		_iflib_completed_tx_reclaim(txq, m_defer, reclaimable);
	}
	mtx_unlock(&txq->ift_mtx);

	/*
	 * Process mbuf frees outside the tx lock
	 */
	if (m_defer != NULL) {
		for (i = 0; m_defer[i] != NULL; i++) {
			m_freem(m_defer[i]);
			m_defer[i] = NULL;
		}
		atomic_store_rel_ptr((uintptr_t *)&txq->ift_sds.ifsd_m_defer,
		    (uintptr_t)m_defer);
	}
	if_inc_counter(ifp, IFCOUNTER_OBYTES, bytes_sent);
	if_inc_counter(ifp, IFCOUNTER_OPACKETS, pkt_sent);
	if (mcast_sent)
		if_inc_counter(ifp, IFCOUNTER_OMCASTS, mcast_sent);

	return (error);

net_down:
	m_freem(m);
	DBG_COUNTER_INC(tx_frees);
	return (ENETDOWN);
}

/*
 * ALTQ entry point.  drbr_dequeue() pulls from ifp->if_snd when a discipline
 * is attached, so the drain loop is shared with the if_transmit path.  Only
 * queue zero is used, matching the queue ALTQ itself selects.
 */
static void
iflib_simple_if_start(if_t ifp)
{
	if_ctx_t ctx;
	iflib_txq_t txq;
	bool retry;
	int bytes_sent = 0, pkt_sent = 0, mcast_sent = 0;

	ctx = if_getsoftc(ifp);
	txq = &ctx->ifc_txqs[0];

	mtx_lock(&txq->ift_mtx);
	(void)iflib_completed_tx_reclaim(txq, NULL);
	iflib_simple_drbr_drain(txq, UINT_MAX, &bytes_sent, &pkt_sent,
	    &mcast_sent);
	if (txq->ift_db_pending != 0)
		(void)iflib_txd_db_check(txq, true);
	retry = !drbr_empty(ifp, txq->ift_drbr);
	mtx_unlock(&txq->ift_mtx);

	if (retry)
		GROUPTASK_ENQUEUE(&txq->ift_task);

	if_inc_counter(ifp, IFCOUNTER_OBYTES, bytes_sent);
	if_inc_counter(ifp, IFCOUNTER_OPACKETS, pkt_sent);
	if (mcast_sent)
		if_inc_counter(ifp, IFCOUNTER_OMCASTS, mcast_sent);
}