xref: /linux/drivers/net/ethernet/intel/e100.c (revision be239684b18e1cdcafcf8c7face4a2f562c745ad)

// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 1999 - 2006 Intel Corporation. */

/*
 *	e100.c: Intel(R) PRO/100 ethernet driver
 *
 *	(Re)written 2003 by scott.feldman@intel.com.  Based loosely on
 *	original e100 driver, but better described as a munging of
 *	e100, e1000, eepro100, tg3, 8139cp, and other drivers.
 *
 *	References:
 *		Intel 8255x 10/100 Mbps Ethernet Controller Family,
 *		Open Source Software Developers Manual,
 *		http://sourceforge.net/projects/e1000
 *
 *
 *	                      Theory of Operation
 *
 *	I.   General
 *
 *	The driver supports Intel(R) 10/100 Mbps PCI Fast Ethernet
 *	controller family, which includes the 82557, 82558, 82559, 82550,
 *	82551, and 82562 devices.  82558 and greater controllers
 *	integrate the Intel 82555 PHY.  The controllers are used in
 *	server and client network interface cards, as well as in
 *	LAN-On-Motherboard (LOM), CardBus, MiniPCI, and ICHx
 *	configurations.  8255x supports a 32-bit linear addressing
 *	mode and operates at 33Mhz PCI clock rate.
 *
 *	II.  Driver Operation
 *
 *	Memory-mapped mode is used exclusively to access the device's
 *	shared-memory structure, the Control/Status Registers (CSR). All
 *	setup, configuration, and control of the device, including queuing
 *	of Tx, Rx, and configuration commands is through the CSR.
 *	cmd_lock serializes accesses to the CSR command register.  cb_lock
 *	protects the shared Command Block List (CBL).
 *
 *	8255x is highly MII-compliant and all access to the PHY go
 *	through the Management Data Interface (MDI).  Consequently, the
 *	driver leverages the mii.c library shared with other MII-compliant
 *	devices.
 *
 *	Big- and Little-Endian byte order as well as 32- and 64-bit
 *	archs are supported.  Weak-ordered memory and non-cache-coherent
 *	archs are supported.
 *
 *	III. Transmit
 *
 *	A Tx skb is mapped and hangs off of a TCB.  TCBs are linked
 *	together in a fixed-size ring (CBL) thus forming the flexible mode
 *	memory structure.  A TCB marked with the suspend-bit indicates
 *	the end of the ring.  The last TCB processed suspends the
 *	controller, and the controller can be restarted by issue a CU
 *	resume command to continue from the suspend point, or a CU start
 *	command to start at a given position in the ring.
 *
 *	Non-Tx commands (config, multicast setup, etc) are linked
 *	into the CBL ring along with Tx commands.  The common structure
 *	used for both Tx and non-Tx commands is the Command Block (CB).
 *
 *	cb_to_use is the next CB to use for queuing a command; cb_to_clean
 *	is the next CB to check for completion; cb_to_send is the first
 *	CB to start on in case of a previous failure to resume.  CB clean
 *	up happens in interrupt context in response to a CU interrupt.
 *	cbs_avail keeps track of number of free CB resources available.
 *
 * 	Hardware padding of short packets to minimum packet size is
 * 	enabled.  82557 pads with 7Eh, while the later controllers pad
 * 	with 00h.
 *
 *	IV.  Receive
 *
 *	The Receive Frame Area (RFA) comprises a ring of Receive Frame
 *	Descriptors (RFD) + data buffer, thus forming the simplified mode
 *	memory structure.  Rx skbs are allocated to contain both the RFD
 *	and the data buffer, but the RFD is pulled off before the skb is
 *	indicated.  The data buffer is aligned such that encapsulated
 *	protocol headers are u32-aligned.  Since the RFD is part of the
 *	mapped shared memory, and completion status is contained within
 *	the RFD, the RFD must be dma_sync'ed to maintain a consistent
 *	view from software and hardware.
 *
 *	In order to keep updates to the RFD link field from colliding with
 *	hardware writes to mark packets complete, we use the feature that
 *	hardware will not write to a size 0 descriptor and mark the previous
 *	packet as end-of-list (EL).   After updating the link, we remove EL
 *	and only then restore the size such that hardware may use the
 *	previous-to-end RFD.
 *
 *	Under typical operation, the  receive unit (RU) is start once,
 *	and the controller happily fills RFDs as frames arrive.  If
 *	replacement RFDs cannot be allocated, or the RU goes non-active,
 *	the RU must be restarted.  Frame arrival generates an interrupt,
 *	and Rx indication and re-allocation happen in the same context,
 *	therefore no locking is required.  A software-generated interrupt
 *	is generated from the watchdog to recover from a failed allocation
 *	scenario where all Rx resources have been indicated and none re-
 *	placed.
 *
 *	V.   Miscellaneous
 *
 * 	VLAN offloading of tagging, stripping and filtering is not
 * 	supported, but driver will accommodate the extra 4-byte VLAN tag
 * 	for processing by upper layers.  Tx/Rx Checksum offloading is not
 * 	supported.  Tx Scatter/Gather is not supported.  Jumbo Frames is
 * 	not supported (hardware limitation).
 *
 * 	MagicPacket(tm) WoL support is enabled/disabled via ethtool.
 *
 * 	Thanks to JC (jchapman@katalix.com) for helping with
 * 	testing/troubleshooting the development driver.
 *
 * 	TODO:
 * 	o several entry points race with dev->close
 * 	o check for tx-no-resources/stop Q races with tx clean/wake Q
 *
 *	FIXES:
 * 2005/12/02 - Michael O'Donnell <Michael.ODonnell at stratus dot com>
 *	- Stratus87247: protect MDI control register manipulations
 * 2009/06/01 - Andreas Mohr <andi at lisas dot de>
 *      - add clean lowlevel I/O emulation for cards with MII-lacking PHYs
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/hardirq.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/mii.h>
#include <linux/if_vlan.h>
#include <linux/skbuff.h>
#include <linux/ethtool.h>
#include <linux/string.h>
#include <linux/firmware.h>
#include <linux/rtnetlink.h>
#include <asm/unaligned.h>


#define DRV_NAME		"e100"
#define DRV_DESCRIPTION		"Intel(R) PRO/100 Network Driver"
#define DRV_COPYRIGHT		"Copyright(c) 1999-2006 Intel Corporation"

#define E100_WATCHDOG_PERIOD	(2 * HZ)
#define E100_NAPI_WEIGHT	16

#define FIRMWARE_D101M		"e100/d101m_ucode.bin"
#define FIRMWARE_D101S		"e100/d101s_ucode.bin"
#define FIRMWARE_D102E		"e100/d102e_ucode.bin"

MODULE_DESCRIPTION(DRV_DESCRIPTION);
MODULE_AUTHOR(DRV_COPYRIGHT);
MODULE_LICENSE("GPL v2");
MODULE_FIRMWARE(FIRMWARE_D101M);
MODULE_FIRMWARE(FIRMWARE_D101S);
MODULE_FIRMWARE(FIRMWARE_D102E);

static int debug = 3;
static int eeprom_bad_csum_allow = 0;
static int use_io = 0;
module_param(debug, int, 0);
module_param(eeprom_bad_csum_allow, int, 0);
module_param(use_io, int, 0);
MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");
MODULE_PARM_DESC(eeprom_bad_csum_allow, "Allow bad eeprom checksums");
MODULE_PARM_DESC(use_io, "Force use of i/o access mode");

#define INTEL_8255X_ETHERNET_DEVICE(device_id, ich) {\
	PCI_VENDOR_ID_INTEL, device_id, PCI_ANY_ID, PCI_ANY_ID, \
	PCI_CLASS_NETWORK_ETHERNET << 8, 0xFFFF00, ich }
static const struct pci_device_id e100_id_table[] = {
	INTEL_8255X_ETHERNET_DEVICE(0x1029, 0),
	INTEL_8255X_ETHERNET_DEVICE(0x1030, 0),
	INTEL_8255X_ETHERNET_DEVICE(0x1031, 3),
	INTEL_8255X_ETHERNET_DEVICE(0x1032, 3),
	INTEL_8255X_ETHERNET_DEVICE(0x1033, 3),
	INTEL_8255X_ETHERNET_DEVICE(0x1034, 3),
	INTEL_8255X_ETHERNET_DEVICE(0x1038, 3),
	INTEL_8255X_ETHERNET_DEVICE(0x1039, 4),
	INTEL_8255X_ETHERNET_DEVICE(0x103A, 4),
	INTEL_8255X_ETHERNET_DEVICE(0x103B, 4),
	INTEL_8255X_ETHERNET_DEVICE(0x103C, 4),
	INTEL_8255X_ETHERNET_DEVICE(0x103D, 4),
	INTEL_8255X_ETHERNET_DEVICE(0x103E, 4),
	INTEL_8255X_ETHERNET_DEVICE(0x1050, 5),
	INTEL_8255X_ETHERNET_DEVICE(0x1051, 5),
	INTEL_8255X_ETHERNET_DEVICE(0x1052, 5),
	INTEL_8255X_ETHERNET_DEVICE(0x1053, 5),
	INTEL_8255X_ETHERNET_DEVICE(0x1054, 5),
	INTEL_8255X_ETHERNET_DEVICE(0x1055, 5),
	INTEL_8255X_ETHERNET_DEVICE(0x1056, 5),
	INTEL_8255X_ETHERNET_DEVICE(0x1057, 5),
	INTEL_8255X_ETHERNET_DEVICE(0x1059, 0),
	INTEL_8255X_ETHERNET_DEVICE(0x1064, 6),
	INTEL_8255X_ETHERNET_DEVICE(0x1065, 6),
	INTEL_8255X_ETHERNET_DEVICE(0x1066, 6),
	INTEL_8255X_ETHERNET_DEVICE(0x1067, 6),
	INTEL_8255X_ETHERNET_DEVICE(0x1068, 6),
	INTEL_8255X_ETHERNET_DEVICE(0x1069, 6),
	INTEL_8255X_ETHERNET_DEVICE(0x106A, 6),
	INTEL_8255X_ETHERNET_DEVICE(0x106B, 6),
	INTEL_8255X_ETHERNET_DEVICE(0x1091, 7),
	INTEL_8255X_ETHERNET_DEVICE(0x1092, 7),
	INTEL_8255X_ETHERNET_DEVICE(0x1093, 7),
	INTEL_8255X_ETHERNET_DEVICE(0x1094, 7),
	INTEL_8255X_ETHERNET_DEVICE(0x1095, 7),
	INTEL_8255X_ETHERNET_DEVICE(0x10fe, 7),
	INTEL_8255X_ETHERNET_DEVICE(0x1209, 0),
	INTEL_8255X_ETHERNET_DEVICE(0x1229, 0),
	INTEL_8255X_ETHERNET_DEVICE(0x2449, 2),
	INTEL_8255X_ETHERNET_DEVICE(0x2459, 2),
	INTEL_8255X_ETHERNET_DEVICE(0x245D, 2),
	INTEL_8255X_ETHERNET_DEVICE(0x27DC, 7),
	{ 0, }
};
MODULE_DEVICE_TABLE(pci, e100_id_table);

enum mac {
	mac_82557_D100_A  = 0,
	mac_82557_D100_B  = 1,
	mac_82557_D100_C  = 2,
	mac_82558_D101_A4 = 4,
	mac_82558_D101_B0 = 5,
	mac_82559_D101M   = 8,
	mac_82559_D101S   = 9,
	mac_82550_D102    = 12,
	mac_82550_D102_C  = 13,
	mac_82551_E       = 14,
	mac_82551_F       = 15,
	mac_82551_10      = 16,
	mac_unknown       = 0xFF,
};

enum phy {
	phy_100a     = 0x000003E0,
	phy_100c     = 0x035002A8,
	phy_82555_tx = 0x015002A8,
	phy_nsc_tx   = 0x5C002000,
	phy_82562_et = 0x033002A8,
	phy_82562_em = 0x032002A8,
	phy_82562_ek = 0x031002A8,
	phy_82562_eh = 0x017002A8,
	phy_82552_v  = 0xd061004d,
	phy_unknown  = 0xFFFFFFFF,
};

/* CSR (Control/Status Registers) */
struct csr {
	struct {
		u8 status;
		u8 stat_ack;
		u8 cmd_lo;
		u8 cmd_hi;
		u32 gen_ptr;
	} scb;
	u32 port;
	u16 flash_ctrl;
	u8 eeprom_ctrl_lo;
	u8 eeprom_ctrl_hi;
	u32 mdi_ctrl;
	u32 rx_dma_count;
};

enum scb_status {
	rus_no_res       = 0x08,
	rus_ready        = 0x10,
	rus_mask         = 0x3C,
};

enum ru_state  {
	RU_SUSPENDED = 0,
	RU_RUNNING	 = 1,
	RU_UNINITIALIZED = -1,
};

enum scb_stat_ack {
	stat_ack_not_ours    = 0x00,
	stat_ack_sw_gen      = 0x04,
	stat_ack_rnr         = 0x10,
	stat_ack_cu_idle     = 0x20,
	stat_ack_frame_rx    = 0x40,
	stat_ack_cu_cmd_done = 0x80,
	stat_ack_not_present = 0xFF,
	stat_ack_rx = (stat_ack_sw_gen | stat_ack_rnr | stat_ack_frame_rx),
	stat_ack_tx = (stat_ack_cu_idle | stat_ack_cu_cmd_done),
};

enum scb_cmd_hi {
	irq_mask_none = 0x00,
	irq_mask_all  = 0x01,
	irq_sw_gen    = 0x02,
};

enum scb_cmd_lo {
	cuc_nop        = 0x00,
	ruc_start      = 0x01,
	ruc_load_base  = 0x06,
	cuc_start      = 0x10,
	cuc_resume     = 0x20,
	cuc_dump_addr  = 0x40,
	cuc_dump_stats = 0x50,
	cuc_load_base  = 0x60,
	cuc_dump_reset = 0x70,
};

enum cuc_dump {
	cuc_dump_complete       = 0x0000A005,
	cuc_dump_reset_complete = 0x0000A007,
};

enum port {
	software_reset  = 0x0000,
	selftest        = 0x0001,
	selective_reset = 0x0002,
};

enum eeprom_ctrl_lo {
	eesk = 0x01,
	eecs = 0x02,
	eedi = 0x04,
	eedo = 0x08,
};

enum mdi_ctrl {
	mdi_write = 0x04000000,
	mdi_read  = 0x08000000,
	mdi_ready = 0x10000000,
};

enum eeprom_op {
	op_write = 0x05,
	op_read  = 0x06,
	op_ewds  = 0x10,
	op_ewen  = 0x13,
};

enum eeprom_offsets {
	eeprom_cnfg_mdix  = 0x03,
	eeprom_phy_iface  = 0x06,
	eeprom_id         = 0x0A,
	eeprom_config_asf = 0x0D,
	eeprom_smbus_addr = 0x90,
};

enum eeprom_cnfg_mdix {
	eeprom_mdix_enabled = 0x0080,
};

enum eeprom_phy_iface {
	NoSuchPhy = 0,
	I82553AB,
	I82553C,
	I82503,
	DP83840,
	S80C240,
	S80C24,
	I82555,
	DP83840A = 10,
};

enum eeprom_id {
	eeprom_id_wol = 0x0020,
};

enum eeprom_config_asf {
	eeprom_asf = 0x8000,
	eeprom_gcl = 0x4000,
};

enum cb_status {
	cb_complete = 0x8000,
	cb_ok       = 0x2000,
};

/*
 * cb_command - Command Block flags
 * @cb_tx_nc:  0: controller does CRC (normal),  1: CRC from skb memory
 */
enum cb_command {
	cb_nop    = 0x0000,
	cb_iaaddr = 0x0001,
	cb_config = 0x0002,
	cb_multi  = 0x0003,
	cb_tx     = 0x0004,
	cb_ucode  = 0x0005,
	cb_dump   = 0x0006,
	cb_tx_sf  = 0x0008,
	cb_tx_nc  = 0x0010,
	cb_cid    = 0x1f00,
	cb_i      = 0x2000,
	cb_s      = 0x4000,
	cb_el     = 0x8000,
};

struct rfd {
	__le16 status;
	__le16 command;
	__le32 link;
	__le32 rbd;
	__le16 actual_size;
	__le16 size;
};

struct rx {
	struct rx *next, *prev;
	struct sk_buff *skb;
	dma_addr_t dma_addr;
};

#if defined(__BIG_ENDIAN_BITFIELD)
#define X(a,b)	b,a
#else
#define X(a,b)	a,b
#endif
struct config {
/*0*/	u8 X(byte_count:6, pad0:2);
/*1*/	u8 X(X(rx_fifo_limit:4, tx_fifo_limit:3), pad1:1);
/*2*/	u8 adaptive_ifs;
/*3*/	u8 X(X(X(X(mwi_enable:1, type_enable:1), read_align_enable:1),
	   term_write_cache_line:1), pad3:4);
/*4*/	u8 X(rx_dma_max_count:7, pad4:1);
/*5*/	u8 X(tx_dma_max_count:7, dma_max_count_enable:1);
/*6*/	u8 X(X(X(X(X(X(X(late_scb_update:1, direct_rx_dma:1),
	   tno_intr:1), cna_intr:1), standard_tcb:1), standard_stat_counter:1),
	   rx_save_overruns : 1), rx_save_bad_frames : 1);
/*7*/	u8 X(X(X(X(X(rx_discard_short_frames:1, tx_underrun_retry:2),
	   pad7:2), rx_extended_rfd:1), tx_two_frames_in_fifo:1),
	   tx_dynamic_tbd:1);
/*8*/	u8 X(X(mii_mode:1, pad8:6), csma_disabled:1);
/*9*/	u8 X(X(X(X(X(rx_tcpudp_checksum:1, pad9:3), vlan_arp_tco:1),
	   link_status_wake:1), arp_wake:1), mcmatch_wake:1);
/*10*/	u8 X(X(X(pad10:3, no_source_addr_insertion:1), preamble_length:2),
	   loopback:2);
/*11*/	u8 X(linear_priority:3, pad11:5);
/*12*/	u8 X(X(linear_priority_mode:1, pad12:3), ifs:4);
/*13*/	u8 ip_addr_lo;
/*14*/	u8 ip_addr_hi;
/*15*/	u8 X(X(X(X(X(X(X(promiscuous_mode:1, broadcast_disabled:1),
	   wait_after_win:1), pad15_1:1), ignore_ul_bit:1), crc_16_bit:1),
	   pad15_2:1), crs_or_cdt:1);
/*16*/	u8 fc_delay_lo;
/*17*/	u8 fc_delay_hi;
/*18*/	u8 X(X(X(X(X(rx_stripping:1, tx_padding:1), rx_crc_transfer:1),
	   rx_long_ok:1), fc_priority_threshold:3), pad18:1);
/*19*/	u8 X(X(X(X(X(X(X(addr_wake:1, magic_packet_disable:1),
	   fc_disable:1), fc_restop:1), fc_restart:1), fc_reject:1),
	   full_duplex_force:1), full_duplex_pin:1);
/*20*/	u8 X(X(X(pad20_1:5, fc_priority_location:1), multi_ia:1), pad20_2:1);
/*21*/	u8 X(X(pad21_1:3, multicast_all:1), pad21_2:4);
/*22*/	u8 X(X(rx_d102_mode:1, rx_vlan_drop:1), pad22:6);
	u8 pad_d102[9];
};

#define E100_MAX_MULTICAST_ADDRS	64
struct multi {
	__le16 count;
	u8 addr[E100_MAX_MULTICAST_ADDRS * ETH_ALEN + 2/*pad*/];
};

/* Important: keep total struct u32-aligned */
#define UCODE_SIZE			134
struct cb {
	__le16 status;
	__le16 command;
	__le32 link;
	union {
		u8 iaaddr[ETH_ALEN];
		__le32 ucode[UCODE_SIZE];
		struct config config;
		struct multi multi;
		struct {
			u32 tbd_array;
			u16 tcb_byte_count;
			u8 threshold;
			u8 tbd_count;
			struct {
				__le32 buf_addr;
				__le16 size;
				u16 eol;
			} tbd;
		} tcb;
		__le32 dump_buffer_addr;
	} u;
	struct cb *next, *prev;
	dma_addr_t dma_addr;
	struct sk_buff *skb;
};

enum loopback {
	lb_none = 0, lb_mac = 1, lb_phy = 3,
};

struct stats {
	__le32 tx_good_frames, tx_max_collisions, tx_late_collisions,
		tx_underruns, tx_lost_crs, tx_deferred, tx_single_collisions,
		tx_multiple_collisions, tx_total_collisions;
	__le32 rx_good_frames, rx_crc_errors, rx_alignment_errors,
		rx_resource_errors, rx_overrun_errors, rx_cdt_errors,
		rx_short_frame_errors;
	__le32 fc_xmt_pause, fc_rcv_pause, fc_rcv_unsupported;
	__le16 xmt_tco_frames, rcv_tco_frames;
	__le32 complete;
};

struct mem {
	struct {
		u32 signature;
		u32 result;
	} selftest;
	struct stats stats;
	u8 dump_buf[596];
};

struct param_range {
	u32 min;
	u32 max;
	u32 count;
};

struct params {
	struct param_range rfds;
	struct param_range cbs;
};

struct nic {
	/* Begin: frequently used values: keep adjacent for cache effect */
	u32 msg_enable				____cacheline_aligned;
	struct net_device *netdev;
	struct pci_dev *pdev;
	u16 (*mdio_ctrl)(struct nic *nic, u32 addr, u32 dir, u32 reg, u16 data);

	struct rx *rxs				____cacheline_aligned;
	struct rx *rx_to_use;
	struct rx *rx_to_clean;
	struct rfd blank_rfd;
	enum ru_state ru_running;

	spinlock_t cb_lock			____cacheline_aligned;
	spinlock_t cmd_lock;
	struct csr __iomem *csr;
	enum scb_cmd_lo cuc_cmd;
	unsigned int cbs_avail;
	struct napi_struct napi;
	struct cb *cbs;
	struct cb *cb_to_use;
	struct cb *cb_to_send;
	struct cb *cb_to_clean;
	__le16 tx_command;
	/* End: frequently used values: keep adjacent for cache effect */

	enum {
		ich                = (1 << 0),
		promiscuous        = (1 << 1),
		multicast_all      = (1 << 2),
		wol_magic          = (1 << 3),
		ich_10h_workaround = (1 << 4),
	} flags					____cacheline_aligned;

	enum mac mac;
	enum phy phy;
	struct params params;
	struct timer_list watchdog;
	struct mii_if_info mii;
	struct work_struct tx_timeout_task;
	enum loopback loopback;

	struct mem *mem;
	dma_addr_t dma_addr;

	struct dma_pool *cbs_pool;
	dma_addr_t cbs_dma_addr;
	u8 adaptive_ifs;
	u8 tx_threshold;
	u32 tx_frames;
	u32 tx_collisions;
	u32 tx_deferred;
	u32 tx_single_collisions;
	u32 tx_multiple_collisions;
	u32 tx_fc_pause;
	u32 tx_tco_frames;

	u32 rx_fc_pause;
	u32 rx_fc_unsupported;
	u32 rx_tco_frames;
	u32 rx_short_frame_errors;
	u32 rx_over_length_errors;

	u16 eeprom_wc;
	__le16 eeprom[256];
	spinlock_t mdio_lock;
	const struct firmware *fw;
};

static inline void e100_write_flush(struct nic *nic)
{
	/* Flush previous PCI writes through intermediate bridges
	 * by doing a benign read */
	(void)ioread8(&nic->csr->scb.status);
}

static void e100_enable_irq(struct nic *nic)
{
	unsigned long flags;

	spin_lock_irqsave(&nic->cmd_lock, flags);
	iowrite8(irq_mask_none, &nic->csr->scb.cmd_hi);
	e100_write_flush(nic);
	spin_unlock_irqrestore(&nic->cmd_lock, flags);
}

static void e100_disable_irq(struct nic *nic)
{
	unsigned long flags;

	spin_lock_irqsave(&nic->cmd_lock, flags);
	iowrite8(irq_mask_all, &nic->csr->scb.cmd_hi);
	e100_write_flush(nic);
	spin_unlock_irqrestore(&nic->cmd_lock, flags);
}

static void e100_hw_reset(struct nic *nic)
{
	/* Put CU and RU into idle with a selective reset to get
	 * device off of PCI bus */
	iowrite32(selective_reset, &nic->csr->port);
	e100_write_flush(nic); udelay(20);

	/* Now fully reset device */
	iowrite32(software_reset, &nic->csr->port);
	e100_write_flush(nic); udelay(20);

	/* Mask off our interrupt line - it's unmasked after reset */
	e100_disable_irq(nic);
}

static int e100_self_test(struct nic *nic)
{
	u32 dma_addr = nic->dma_addr + offsetof(struct mem, selftest);

	/* Passing the self-test is a pretty good indication
	 * that the device can DMA to/from host memory */

	nic->mem->selftest.signature = 0;
	nic->mem->selftest.result = 0xFFFFFFFF;

	iowrite32(selftest | dma_addr, &nic->csr->port);
	e100_write_flush(nic);
	/* Wait 10 msec for self-test to complete */
	msleep(10);

	/* Interrupts are enabled after self-test */
	e100_disable_irq(nic);

	/* Check results of self-test */
	if (nic->mem->selftest.result != 0) {
		netif_err(nic, hw, nic->netdev,
			  "Self-test failed: result=0x%08X\n",
			  nic->mem->selftest.result);
		return -ETIMEDOUT;
	}
	if (nic->mem->selftest.signature == 0) {
		netif_err(nic, hw, nic->netdev, "Self-test failed: timed out\n");
		return -ETIMEDOUT;
	}

	return 0;
}

static void e100_eeprom_write(struct nic *nic, u16 addr_len, u16 addr, __le16 data)
{
	u32 cmd_addr_data[3];
	u8 ctrl;
	int i, j;

	/* Three cmds: write/erase enable, write data, write/erase disable */
	cmd_addr_data[0] = op_ewen << (addr_len - 2);
	cmd_addr_data[1] = (((op_write << addr_len) | addr) << 16) |
		le16_to_cpu(data);
	cmd_addr_data[2] = op_ewds << (addr_len - 2);

	/* Bit-bang cmds to write word to eeprom */
	for (j = 0; j < 3; j++) {

		/* Chip select */
		iowrite8(eecs | eesk, &nic->csr->eeprom_ctrl_lo);
		e100_write_flush(nic); udelay(4);

		for (i = 31; i >= 0; i--) {
			ctrl = (cmd_addr_data[j] & (1 << i)) ?
				eecs | eedi : eecs;
			iowrite8(ctrl, &nic->csr->eeprom_ctrl_lo);
			e100_write_flush(nic); udelay(4);

			iowrite8(ctrl | eesk, &nic->csr->eeprom_ctrl_lo);
			e100_write_flush(nic); udelay(4);
		}
		/* Wait 10 msec for cmd to complete */
		msleep(10);

		/* Chip deselect */
		iowrite8(0, &nic->csr->eeprom_ctrl_lo);
		e100_write_flush(nic); udelay(4);
	}
};

/* General technique stolen from the eepro100 driver - very clever */
static __le16 e100_eeprom_read(struct nic *nic, u16 *addr_len, u16 addr)
{
	u32 cmd_addr_data;
	u16 data = 0;
	u8 ctrl;
	int i;

	cmd_addr_data = ((op_read << *addr_len) | addr) << 16;

	/* Chip select */
	iowrite8(eecs | eesk, &nic->csr->eeprom_ctrl_lo);
	e100_write_flush(nic); udelay(4);

	/* Bit-bang to read word from eeprom */
	for (i = 31; i >= 0; i--) {
		ctrl = (cmd_addr_data & (1 << i)) ? eecs | eedi : eecs;
		iowrite8(ctrl, &nic->csr->eeprom_ctrl_lo);
		e100_write_flush(nic); udelay(4);

		iowrite8(ctrl | eesk, &nic->csr->eeprom_ctrl_lo);
		e100_write_flush(nic); udelay(4);

		/* Eeprom drives a dummy zero to EEDO after receiving
		 * complete address.  Use this to adjust addr_len. */
		ctrl = ioread8(&nic->csr->eeprom_ctrl_lo);
		if (!(ctrl & eedo) && i > 16) {
			*addr_len -= (i - 16);
			i = 17;
		}

		data = (data << 1) | (ctrl & eedo ? 1 : 0);
	}

	/* Chip deselect */
	iowrite8(0, &nic->csr->eeprom_ctrl_lo);
	e100_write_flush(nic); udelay(4);

	return cpu_to_le16(data);
};

/* Load entire EEPROM image into driver cache and validate checksum */
static int e100_eeprom_load(struct nic *nic)
{
	u16 addr, addr_len = 8, checksum = 0;

	/* Try reading with an 8-bit addr len to discover actual addr len */
	e100_eeprom_read(nic, &addr_len, 0);
	nic->eeprom_wc = 1 << addr_len;

	for (addr = 0; addr < nic->eeprom_wc; addr++) {
		nic->eeprom[addr] = e100_eeprom_read(nic, &addr_len, addr);
		if (addr < nic->eeprom_wc - 1)
			checksum += le16_to_cpu(nic->eeprom[addr]);
	}

	/* The checksum, stored in the last word, is calculated such that
	 * the sum of words should be 0xBABA */
	if (cpu_to_le16(0xBABA - checksum) != nic->eeprom[nic->eeprom_wc - 1]) {
		netif_err(nic, probe, nic->netdev, "EEPROM corrupted\n");
		if (!eeprom_bad_csum_allow)
			return -EAGAIN;
	}

	return 0;
}

/* Save (portion of) driver EEPROM cache to device and update checksum */
static int e100_eeprom_save(struct nic *nic, u16 start, u16 count)
{
	u16 addr, addr_len = 8, checksum = 0;

	/* Try reading with an 8-bit addr len to discover actual addr len */
	e100_eeprom_read(nic, &addr_len, 0);
	nic->eeprom_wc = 1 << addr_len;

	if (start + count >= nic->eeprom_wc)
		return -EINVAL;

	for (addr = start; addr < start + count; addr++)
		e100_eeprom_write(nic, addr_len, addr, nic->eeprom[addr]);

	/* The checksum, stored in the last word, is calculated such that
	 * the sum of words should be 0xBABA */
	for (addr = 0; addr < nic->eeprom_wc - 1; addr++)
		checksum += le16_to_cpu(nic->eeprom[addr]);
	nic->eeprom[nic->eeprom_wc - 1] = cpu_to_le16(0xBABA - checksum);
	e100_eeprom_write(nic, addr_len, nic->eeprom_wc - 1,
		nic->eeprom[nic->eeprom_wc - 1]);

	return 0;
}

#define E100_WAIT_SCB_TIMEOUT 20000 /* we might have to wait 100ms!!! */
#define E100_WAIT_SCB_FAST 20       /* delay like the old code */
static int e100_exec_cmd(struct nic *nic, u8 cmd, dma_addr_t dma_addr)
{
	unsigned long flags;
	unsigned int i;
	int err = 0;

	spin_lock_irqsave(&nic->cmd_lock, flags);

	/* Previous command is accepted when SCB clears */
	for (i = 0; i < E100_WAIT_SCB_TIMEOUT; i++) {
		if (likely(!ioread8(&nic->csr->scb.cmd_lo)))
			break;
		cpu_relax();
		if (unlikely(i > E100_WAIT_SCB_FAST))
			udelay(5);
	}
	if (unlikely(i == E100_WAIT_SCB_TIMEOUT)) {
		err = -EAGAIN;
		goto err_unlock;
	}

	if (unlikely(cmd != cuc_resume))
		iowrite32(dma_addr, &nic->csr->scb.gen_ptr);
	iowrite8(cmd, &nic->csr->scb.cmd_lo);

err_unlock:
	spin_unlock_irqrestore(&nic->cmd_lock, flags);

	return err;
}

static int e100_exec_cb(struct nic *nic, struct sk_buff *skb,
	int (*cb_prepare)(struct nic *, struct cb *, struct sk_buff *))
{
	struct cb *cb;
	unsigned long flags;
	int err;

	spin_lock_irqsave(&nic->cb_lock, flags);

	if (unlikely(!nic->cbs_avail)) {
		err = -ENOMEM;
		goto err_unlock;
	}

	cb = nic->cb_to_use;
	nic->cb_to_use = cb->next;
	nic->cbs_avail--;
	cb->skb = skb;

	err = cb_prepare(nic, cb, skb);
	if (err)
		goto err_unlock;

	if (unlikely(!nic->cbs_avail))
		err = -ENOSPC;


	/* Order is important otherwise we'll be in a race with h/w:
	 * set S-bit in current first, then clear S-bit in previous. */
	cb->command |= cpu_to_le16(cb_s);
	dma_wmb();
	cb->prev->command &= cpu_to_le16(~cb_s);

	while (nic->cb_to_send != nic->cb_to_use) {
		if (unlikely(e100_exec_cmd(nic, nic->cuc_cmd,
			nic->cb_to_send->dma_addr))) {
			/* Ok, here's where things get sticky.  It's
			 * possible that we can't schedule the command
			 * because the controller is too busy, so
			 * let's just queue the command and try again
			 * when another command is scheduled. */
			if (err == -ENOSPC) {
				//request a reset
				schedule_work(&nic->tx_timeout_task);
			}
			break;
		} else {
			nic->cuc_cmd = cuc_resume;
			nic->cb_to_send = nic->cb_to_send->next;
		}
	}

err_unlock:
	spin_unlock_irqrestore(&nic->cb_lock, flags);

	return err;
}

static int mdio_read(struct net_device *netdev, int addr, int reg)
{
	struct nic *nic = netdev_priv(netdev);
	return nic->mdio_ctrl(nic, addr, mdi_read, reg, 0);
}

static void mdio_write(struct net_device *netdev, int addr, int reg, int data)
{
	struct nic *nic = netdev_priv(netdev);

	nic->mdio_ctrl(nic, addr, mdi_write, reg, data);
}

/* the standard mdio_ctrl() function for usual MII-compliant hardware */
static u16 mdio_ctrl_hw(struct nic *nic, u32 addr, u32 dir, u32 reg, u16 data)
{
	u32 data_out = 0;
	unsigned int i;
	unsigned long flags;


	/*
	 * Stratus87247: we shouldn't be writing the MDI control
	 * register until the Ready bit shows True.  Also, since
	 * manipulation of the MDI control registers is a multi-step
	 * procedure it should be done under lock.
	 */
	spin_lock_irqsave(&nic->mdio_lock, flags);
	for (i = 100; i; --i) {
		if (ioread32(&nic->csr->mdi_ctrl) & mdi_ready)
			break;
		udelay(20);
	}
	if (unlikely(!i)) {
		netdev_err(nic->netdev, "e100.mdio_ctrl won't go Ready\n");
		spin_unlock_irqrestore(&nic->mdio_lock, flags);
		return 0;		/* No way to indicate timeout error */
	}
	iowrite32((reg << 16) | (addr << 21) | dir | data, &nic->csr->mdi_ctrl);

	for (i = 0; i < 100; i++) {
		udelay(20);
		if ((data_out = ioread32(&nic->csr->mdi_ctrl)) & mdi_ready)
			break;
	}
	spin_unlock_irqrestore(&nic->mdio_lock, flags);
	netif_printk(nic, hw, KERN_DEBUG, nic->netdev,
		     "%s:addr=%d, reg=%d, data_in=0x%04X, data_out=0x%04X\n",
		     dir == mdi_read ? "READ" : "WRITE",
		     addr, reg, data, data_out);
	return (u16)data_out;
}

/* slightly tweaked mdio_ctrl() function for phy_82552_v specifics */
static u16 mdio_ctrl_phy_82552_v(struct nic *nic,
				 u32 addr,
				 u32 dir,
				 u32 reg,
				 u16 data)
{
	if ((reg == MII_BMCR) && (dir == mdi_write)) {
		if (data & (BMCR_ANRESTART | BMCR_ANENABLE)) {
			u16 advert = mdio_read(nic->netdev, nic->mii.phy_id,
							MII_ADVERTISE);

			/*
			 * Workaround Si issue where sometimes the part will not
			 * autoneg to 100Mbps even when advertised.
			 */
			if (advert & ADVERTISE_100FULL)
				data |= BMCR_SPEED100 | BMCR_FULLDPLX;
			else if (advert & ADVERTISE_100HALF)
				data |= BMCR_SPEED100;
		}
	}
	return mdio_ctrl_hw(nic, addr, dir, reg, data);
}

/* Fully software-emulated mdio_ctrl() function for cards without
 * MII-compliant PHYs.
 * For now, this is mainly geared towards 80c24 support; in case of further
 * requirements for other types (i82503, ...?) either extend this mechanism
 * or split it, whichever is cleaner.
 */
static u16 mdio_ctrl_phy_mii_emulated(struct nic *nic,
				      u32 addr,
				      u32 dir,
				      u32 reg,
				      u16 data)
{
	/* might need to allocate a netdev_priv'ed register array eventually
	 * to be able to record state changes, but for now
	 * some fully hardcoded register handling ought to be ok I guess. */

	if (dir == mdi_read) {
		switch (reg) {
		case MII_BMCR:
			/* Auto-negotiation, right? */
			return  BMCR_ANENABLE |
				BMCR_FULLDPLX;
		case MII_BMSR:
			return	BMSR_LSTATUS /* for mii_link_ok() */ |
				BMSR_ANEGCAPABLE |
				BMSR_10FULL;
		case MII_ADVERTISE:
			/* 80c24 is a "combo card" PHY, right? */
			return	ADVERTISE_10HALF |
				ADVERTISE_10FULL;
		default:
			netif_printk(nic, hw, KERN_DEBUG, nic->netdev,
				     "%s:addr=%d, reg=%d, data=0x%04X: unimplemented emulation!\n",
				     dir == mdi_read ? "READ" : "WRITE",
				     addr, reg, data);
			return 0xFFFF;
		}
	} else {
		switch (reg) {
		default:
			netif_printk(nic, hw, KERN_DEBUG, nic->netdev,
				     "%s:addr=%d, reg=%d, data=0x%04X: unimplemented emulation!\n",
				     dir == mdi_read ? "READ" : "WRITE",
				     addr, reg, data);
			return 0xFFFF;
		}
	}
}
static inline int e100_phy_supports_mii(struct nic *nic)
{
	/* for now, just check it by comparing whether we
	   are using MII software emulation.
	*/
	return (nic->mdio_ctrl != mdio_ctrl_phy_mii_emulated);
}

static void e100_get_defaults(struct nic *nic)
{
	struct param_range rfds = { .min = 16, .max = 256, .count = 256 };
	struct param_range cbs  = { .min = 64, .max = 256, .count = 128 };

	/* MAC type is encoded as rev ID; exception: ICH is treated as 82559 */
	nic->mac = (nic->flags & ich) ? mac_82559_D101M : nic->pdev->revision;
	if (nic->mac == mac_unknown)
		nic->mac = mac_82557_D100_A;

	nic->params.rfds = rfds;
	nic->params.cbs = cbs;

	/* Quadwords to DMA into FIFO before starting frame transmit */
	nic->tx_threshold = 0xE0;

	/* no interrupt for every tx completion, delay = 256us if not 557 */
	nic->tx_command = cpu_to_le16(cb_tx | cb_tx_sf |
		((nic->mac >= mac_82558_D101_A4) ? cb_cid : cb_i));

	/* Template for a freshly allocated RFD */
	nic->blank_rfd.command = 0;
	nic->blank_rfd.rbd = cpu_to_le32(0xFFFFFFFF);
	nic->blank_rfd.size = cpu_to_le16(VLAN_ETH_FRAME_LEN + ETH_FCS_LEN);

	/* MII setup */
	nic->mii.phy_id_mask = 0x1F;
	nic->mii.reg_num_mask = 0x1F;
	nic->mii.dev = nic->netdev;
	nic->mii.mdio_read = mdio_read;
	nic->mii.mdio_write = mdio_write;
}

static int e100_configure(struct nic *nic, struct cb *cb, struct sk_buff *skb)
{
	struct config *config = &cb->u.config;
	u8 *c = (u8 *)config;
	struct net_device *netdev = nic->netdev;

	cb->command = cpu_to_le16(cb_config);

	memset(config, 0, sizeof(struct config));

	config->byte_count = 0x16;		/* bytes in this struct */
	config->rx_fifo_limit = 0x8;		/* bytes in FIFO before DMA */
	config->direct_rx_dma = 0x1;		/* reserved */
	config->standard_tcb = 0x1;		/* 1=standard, 0=extended */
	config->standard_stat_counter = 0x1;	/* 1=standard, 0=extended */
	config->rx_discard_short_frames = 0x1;	/* 1=discard, 0=pass */
	config->tx_underrun_retry = 0x3;	/* # of underrun retries */
	if (e100_phy_supports_mii(nic))
		config->mii_mode = 1;           /* 1=MII mode, 0=i82503 mode */
	config->pad10 = 0x6;
	config->no_source_addr_insertion = 0x1;	/* 1=no, 0=yes */
	config->preamble_length = 0x2;		/* 0=1, 1=3, 2=7, 3=15 bytes */
	config->ifs = 0x6;			/* x16 = inter frame spacing */
	config->ip_addr_hi = 0xF2;		/* ARP IP filter - not used */
	config->pad15_1 = 0x1;
	config->pad15_2 = 0x1;
	config->crs_or_cdt = 0x0;		/* 0=CRS only, 1=CRS or CDT */
	config->fc_delay_hi = 0x40;		/* time delay for fc frame */
	config->tx_padding = 0x1;		/* 1=pad short frames */
	config->fc_priority_threshold = 0x7;	/* 7=priority fc disabled */
	config->pad18 = 0x1;
	config->full_duplex_pin = 0x1;		/* 1=examine FDX# pin */
	config->pad20_1 = 0x1F;
	config->fc_priority_location = 0x1;	/* 1=byte#31, 0=byte#19 */
	config->pad21_1 = 0x5;

	config->adaptive_ifs = nic->adaptive_ifs;
	config->loopback = nic->loopback;

	if (nic->mii.force_media && nic->mii.full_duplex)
		config->full_duplex_force = 0x1;	/* 1=force, 0=auto */

	if (nic->flags & promiscuous || nic->loopback) {
		config->rx_save_bad_frames = 0x1;	/* 1=save, 0=discard */
		config->rx_discard_short_frames = 0x0;	/* 1=discard, 0=save */
		config->promiscuous_mode = 0x1;		/* 1=on, 0=off */
	}

	if (unlikely(netdev->features & NETIF_F_RXFCS))
		config->rx_crc_transfer = 0x1;	/* 1=save, 0=discard */

	if (nic->flags & multicast_all)
		config->multicast_all = 0x1;		/* 1=accept, 0=no */

	/* disable WoL when up */
	if (netif_running(nic->netdev) || !(nic->flags & wol_magic))
		config->magic_packet_disable = 0x1;	/* 1=off, 0=on */

	if (nic->mac >= mac_82558_D101_A4) {
		config->fc_disable = 0x1;	/* 1=Tx fc off, 0=Tx fc on */
		config->mwi_enable = 0x1;	/* 1=enable, 0=disable */
		config->standard_tcb = 0x0;	/* 1=standard, 0=extended */
		config->rx_long_ok = 0x1;	/* 1=VLANs ok, 0=standard */
		if (nic->mac >= mac_82559_D101M) {
			config->tno_intr = 0x1;		/* TCO stats enable */
			/* Enable TCO in extended config */
			if (nic->mac >= mac_82551_10) {
				config->byte_count = 0x20; /* extended bytes */
				config->rx_d102_mode = 0x1; /* GMRC for TCO */
			}
		} else {
			config->standard_stat_counter = 0x0;
		}
	}

	if (netdev->features & NETIF_F_RXALL) {
		config->rx_save_overruns = 0x1; /* 1=save, 0=discard */
		config->rx_save_bad_frames = 0x1;       /* 1=save, 0=discard */
		config->rx_discard_short_frames = 0x0;  /* 1=discard, 0=save */
	}

	netif_printk(nic, hw, KERN_DEBUG, nic->netdev, "[00-07]=%8ph\n",
		     c + 0);
	netif_printk(nic, hw, KERN_DEBUG, nic->netdev, "[08-15]=%8ph\n",
		     c + 8);
	netif_printk(nic, hw, KERN_DEBUG, nic->netdev, "[16-23]=%8ph\n",
		     c + 16);
	return 0;
}

/*************************************************************************
*  CPUSaver parameters
*
*  All CPUSaver parameters are 16-bit literals that are part of a
*  "move immediate value" instruction.  By changing the value of
*  the literal in the instruction before the code is loaded, the
*  driver can change the algorithm.
*
*  INTDELAY - This loads the dead-man timer with its initial value.
*    When this timer expires the interrupt is asserted, and the
*    timer is reset each time a new packet is received.  (see
*    BUNDLEMAX below to set the limit on number of chained packets)
*    The current default is 0x600 or 1536.  Experiments show that
*    the value should probably stay within the 0x200 - 0x1000.
*
*  BUNDLEMAX -
*    This sets the maximum number of frames that will be bundled.  In
*    some situations, such as the TCP windowing algorithm, it may be
*    better to limit the growth of the bundle size than let it go as
*    high as it can, because that could cause too much added latency.
*    The default is six, because this is the number of packets in the
*    default TCP window size.  A value of 1 would make CPUSaver indicate
*    an interrupt for every frame received.  If you do not want to put
*    a limit on the bundle size, set this value to xFFFF.
*
*  BUNDLESMALL -
*    This contains a bit-mask describing the minimum size frame that
*    will be bundled.  The default masks the lower 7 bits, which means
*    that any frame less than 128 bytes in length will not be bundled,
*    but will instead immediately generate an interrupt.  This does
*    not affect the current bundle in any way.  Any frame that is 128
*    bytes or large will be bundled normally.  This feature is meant
*    to provide immediate indication of ACK frames in a TCP environment.
*    Customers were seeing poor performance when a machine with CPUSaver
*    enabled was sending but not receiving.  The delay introduced when
*    the ACKs were received was enough to reduce total throughput, because
*    the sender would sit idle until the ACK was finally seen.
*
*    The current default is 0xFF80, which masks out the lower 7 bits.
*    This means that any frame which is x7F (127) bytes or smaller
*    will cause an immediate interrupt.  Because this value must be a
*    bit mask, there are only a few valid values that can be used.  To
*    turn this feature off, the driver can write the value xFFFF to the
*    lower word of this instruction (in the same way that the other
*    parameters are used).  Likewise, a value of 0xF800 (2047) would
*    cause an interrupt to be generated for every frame, because all
*    standard Ethernet frames are <= 2047 bytes in length.
*************************************************************************/

/* if you wish to disable the ucode functionality, while maintaining the
 * workarounds it provides, set the following defines to:
 * BUNDLESMALL 0
 * BUNDLEMAX 1
 * INTDELAY 1
 */
#define BUNDLESMALL 1
#define BUNDLEMAX (u16)6
#define INTDELAY (u16)1536 /* 0x600 */

/* Initialize firmware */
static const struct firmware *e100_request_firmware(struct nic *nic)
{
	const char *fw_name;
	const struct firmware *fw = nic->fw;
	u8 timer, bundle, min_size;
	int err = 0;
	bool required = false;

	/* do not load u-code for ICH devices */
	if (nic->flags & ich)
		return NULL;

	/* Search for ucode match against h/w revision
	 *
	 * Based on comments in the source code for the FreeBSD fxp
	 * driver, the FIRMWARE_D102E ucode includes both CPUSaver and
	 *
	 *    "fixes for bugs in the B-step hardware (specifically, bugs
	 *     with Inline Receive)."
	 *
	 * So we must fail if it cannot be loaded.
	 *
	 * The other microcode files are only required for the optional
	 * CPUSaver feature.  Nice to have, but no reason to fail.
	 */
	if (nic->mac == mac_82559_D101M) {
		fw_name = FIRMWARE_D101M;
	} else if (nic->mac == mac_82559_D101S) {
		fw_name = FIRMWARE_D101S;
	} else if (nic->mac == mac_82551_F || nic->mac == mac_82551_10) {
		fw_name = FIRMWARE_D102E;
		required = true;
	} else { /* No ucode on other devices */
		return NULL;
	}

	/* If the firmware has not previously been loaded, request a pointer
	 * to it. If it was previously loaded, we are reinitializing the
	 * adapter, possibly in a resume from hibernate, in which case
	 * request_firmware() cannot be used.
	 */
	if (!fw)
		err = request_firmware(&fw, fw_name, &nic->pdev->dev);

	if (err) {
		if (required) {
			netif_err(nic, probe, nic->netdev,
				  "Failed to load firmware \"%s\": %d\n",
				  fw_name, err);
			return ERR_PTR(err);
		} else {
			netif_info(nic, probe, nic->netdev,
				   "CPUSaver disabled. Needs \"%s\": %d\n",
				   fw_name, err);
			return NULL;
		}
	}

	/* Firmware should be precisely UCODE_SIZE (words) plus three bytes
	   indicating the offsets for BUNDLESMALL, BUNDLEMAX, INTDELAY */
	if (fw->size != UCODE_SIZE * 4 + 3) {
		netif_err(nic, probe, nic->netdev,
			  "Firmware \"%s\" has wrong size %zu\n",
			  fw_name, fw->size);
		release_firmware(fw);
		return ERR_PTR(-EINVAL);
	}

	/* Read timer, bundle and min_size from end of firmware blob */
	timer = fw->data[UCODE_SIZE * 4];
	bundle = fw->data[UCODE_SIZE * 4 + 1];
	min_size = fw->data[UCODE_SIZE * 4 + 2];

	if (timer >= UCODE_SIZE || bundle >= UCODE_SIZE ||
	    min_size >= UCODE_SIZE) {
		netif_err(nic, probe, nic->netdev,
			  "\"%s\" has bogus offset values (0x%x,0x%x,0x%x)\n",
			  fw_name, timer, bundle, min_size);
		release_firmware(fw);
		return ERR_PTR(-EINVAL);
	}

	/* OK, firmware is validated and ready to use. Save a pointer
	 * to it in the nic */
	nic->fw = fw;
	return fw;
}

static int e100_setup_ucode(struct nic *nic, struct cb *cb,
			     struct sk_buff *skb)
{
	const struct firmware *fw = (void *)skb;
	u8 timer, bundle, min_size;

	/* It's not a real skb; we just abused the fact that e100_exec_cb
	   will pass it through to here... */
	cb->skb = NULL;

	/* firmware is stored as little endian already */
	memcpy(cb->u.ucode, fw->data, UCODE_SIZE * 4);

	/* Read timer, bundle and min_size from end of firmware blob */
	timer = fw->data[UCODE_SIZE * 4];
	bundle = fw->data[UCODE_SIZE * 4 + 1];
	min_size = fw->data[UCODE_SIZE * 4 + 2];

	/* Insert user-tunable settings in cb->u.ucode */
	cb->u.ucode[timer] &= cpu_to_le32(0xFFFF0000);
	cb->u.ucode[timer] |= cpu_to_le32(INTDELAY);
	cb->u.ucode[bundle] &= cpu_to_le32(0xFFFF0000);
	cb->u.ucode[bundle] |= cpu_to_le32(BUNDLEMAX);
	cb->u.ucode[min_size] &= cpu_to_le32(0xFFFF0000);
	cb->u.ucode[min_size] |= cpu_to_le32((BUNDLESMALL) ? 0xFFFF : 0xFF80);

	cb->command = cpu_to_le16(cb_ucode | cb_el);
	return 0;
}

static inline int e100_load_ucode_wait(struct nic *nic)
{
	const struct firmware *fw;
	int err = 0, counter = 50;
	struct cb *cb = nic->cb_to_clean;

	fw = e100_request_firmware(nic);
	/* If it's NULL, then no ucode is required */
	if (IS_ERR_OR_NULL(fw))
		return PTR_ERR_OR_ZERO(fw);

	if ((err = e100_exec_cb(nic, (void *)fw, e100_setup_ucode)))
		netif_err(nic, probe, nic->netdev,
			  "ucode cmd failed with error %d\n", err);

	/* must restart cuc */
	nic->cuc_cmd = cuc_start;

	/* wait for completion */
	e100_write_flush(nic);
	udelay(10);

	/* wait for possibly (ouch) 500ms */
	while (!(cb->status & cpu_to_le16(cb_complete))) {
		msleep(10);
		if (!--counter) break;
	}

	/* ack any interrupts, something could have been set */
	iowrite8(~0, &nic->csr->scb.stat_ack);

	/* if the command failed, or is not OK, notify and return */
	if (!counter || !(cb->status & cpu_to_le16(cb_ok))) {
		netif_err(nic, probe, nic->netdev, "ucode load failed\n");
		err = -EPERM;
	}

	return err;
}

static int e100_setup_iaaddr(struct nic *nic, struct cb *cb,
	struct sk_buff *skb)
{
	cb->command = cpu_to_le16(cb_iaaddr);
	memcpy(cb->u.iaaddr, nic->netdev->dev_addr, ETH_ALEN);
	return 0;
}

static int e100_dump(struct nic *nic, struct cb *cb, struct sk_buff *skb)
{
	cb->command = cpu_to_le16(cb_dump);
	cb->u.dump_buffer_addr = cpu_to_le32(nic->dma_addr +
		offsetof(struct mem, dump_buf));
	return 0;
}

static int e100_phy_check_without_mii(struct nic *nic)
{
	u8 phy_type;
	int without_mii;

	phy_type = (le16_to_cpu(nic->eeprom[eeprom_phy_iface]) >> 8) & 0x0f;

	switch (phy_type) {
	case NoSuchPhy: /* Non-MII PHY; UNTESTED! */
	case I82503: /* Non-MII PHY; UNTESTED! */
	case S80C24: /* Non-MII PHY; tested and working */
		/* paragraph from the FreeBSD driver, "FXP_PHY_80C24":
		 * The Seeq 80c24 AutoDUPLEX(tm) Ethernet Interface Adapter
		 * doesn't have a programming interface of any sort.  The
		 * media is sensed automatically based on how the link partner
		 * is configured.  This is, in essence, manual configuration.
		 */
		netif_info(nic, probe, nic->netdev,
			   "found MII-less i82503 or 80c24 or other PHY\n");

		nic->mdio_ctrl = mdio_ctrl_phy_mii_emulated;
		nic->mii.phy_id = 0; /* is this ok for an MII-less PHY? */

		/* these might be needed for certain MII-less cards...
		 * nic->flags |= ich;
		 * nic->flags |= ich_10h_workaround; */

		without_mii = 1;
		break;
	default:
		without_mii = 0;
		break;
	}
	return without_mii;
}

#define NCONFIG_AUTO_SWITCH	0x0080
#define MII_NSC_CONG		MII_RESV1
#define NSC_CONG_ENABLE		0x0100
#define NSC_CONG_TXREADY	0x0400
static int e100_phy_init(struct nic *nic)
{
	struct net_device *netdev = nic->netdev;
	u32 addr;
	u16 bmcr, stat, id_lo, id_hi, cong;

	/* Discover phy addr by searching addrs in order {1,0,2,..., 31} */
	for (addr = 0; addr < 32; addr++) {
		nic->mii.phy_id = (addr == 0) ? 1 : (addr == 1) ? 0 : addr;
		bmcr = mdio_read(netdev, nic->mii.phy_id, MII_BMCR);
		stat = mdio_read(netdev, nic->mii.phy_id, MII_BMSR);
		stat = mdio_read(netdev, nic->mii.phy_id, MII_BMSR);
		if (!((bmcr == 0xFFFF) || ((stat == 0) && (bmcr == 0))))
			break;
	}
	if (addr == 32) {
		/* uhoh, no PHY detected: check whether we seem to be some
		 * weird, rare variant which is *known* to not have any MII.
		 * But do this AFTER MII checking only, since this does
		 * lookup of EEPROM values which may easily be unreliable. */
		if (e100_phy_check_without_mii(nic))
			return 0; /* simply return and hope for the best */
		else {
			/* for unknown cases log a fatal error */
			netif_err(nic, hw, nic->netdev,
				  "Failed to locate any known PHY, aborting\n");
			return -EAGAIN;
		}
	} else
		netif_printk(nic, hw, KERN_DEBUG, nic->netdev,
			     "phy_addr = %d\n", nic->mii.phy_id);

	/* Get phy ID */
	id_lo = mdio_read(netdev, nic->mii.phy_id, MII_PHYSID1);
	id_hi = mdio_read(netdev, nic->mii.phy_id, MII_PHYSID2);
	nic->phy = (u32)id_hi << 16 | (u32)id_lo;
	netif_printk(nic, hw, KERN_DEBUG, nic->netdev,
		     "phy ID = 0x%08X\n", nic->phy);

	/* Select the phy and isolate the rest */
	for (addr = 0; addr < 32; addr++) {
		if (addr != nic->mii.phy_id) {
			mdio_write(netdev, addr, MII_BMCR, BMCR_ISOLATE);
		} else if (nic->phy != phy_82552_v) {
			bmcr = mdio_read(netdev, addr, MII_BMCR);
			mdio_write(netdev, addr, MII_BMCR,
				bmcr & ~BMCR_ISOLATE);
		}
	}
	/*
	 * Workaround for 82552:
	 * Clear the ISOLATE bit on selected phy_id last (mirrored on all
	 * other phy_id's) using bmcr value from addr discovery loop above.
	 */
	if (nic->phy == phy_82552_v)
		mdio_write(netdev, nic->mii.phy_id, MII_BMCR,
			bmcr & ~BMCR_ISOLATE);

	/* Handle National tx phys */
#define NCS_PHY_MODEL_MASK	0xFFF0FFFF
	if ((nic->phy & NCS_PHY_MODEL_MASK) == phy_nsc_tx) {
		/* Disable congestion control */
		cong = mdio_read(netdev, nic->mii.phy_id, MII_NSC_CONG);
		cong |= NSC_CONG_TXREADY;
		cong &= ~NSC_CONG_ENABLE;
		mdio_write(netdev, nic->mii.phy_id, MII_NSC_CONG, cong);
	}

	if (nic->phy == phy_82552_v) {
		u16 advert = mdio_read(netdev, nic->mii.phy_id, MII_ADVERTISE);

		/* assign special tweaked mdio_ctrl() function */
		nic->mdio_ctrl = mdio_ctrl_phy_82552_v;

		/* Workaround Si not advertising flow-control during autoneg */
		advert |= ADVERTISE_PAUSE_CAP | ADVERTISE_PAUSE_ASYM;
		mdio_write(netdev, nic->mii.phy_id, MII_ADVERTISE, advert);

		/* Reset for the above changes to take effect */
		bmcr = mdio_read(netdev, nic->mii.phy_id, MII_BMCR);
		bmcr |= BMCR_RESET;
		mdio_write(netdev, nic->mii.phy_id, MII_BMCR, bmcr);
	} else if ((nic->mac >= mac_82550_D102) || ((nic->flags & ich) &&
	   (mdio_read(netdev, nic->mii.phy_id, MII_TPISTATUS) & 0x8000) &&
	   (le16_to_cpu(nic->eeprom[eeprom_cnfg_mdix]) & eeprom_mdix_enabled))) {
		/* enable/disable MDI/MDI-X auto-switching. */
		mdio_write(netdev, nic->mii.phy_id, MII_NCONFIG,
				nic->mii.force_media ? 0 : NCONFIG_AUTO_SWITCH);
	}

	return 0;
}

static int e100_hw_init(struct nic *nic)
{
	int err = 0;

	e100_hw_reset(nic);

	netif_err(nic, hw, nic->netdev, "e100_hw_init\n");
	if ((err = e100_self_test(nic)))
		return err;

	if ((err = e100_phy_init(nic)))
		return err;
	if ((err = e100_exec_cmd(nic, cuc_load_base, 0)))
		return err;
	if ((err = e100_exec_cmd(nic, ruc_load_base, 0)))
		return err;
	if ((err = e100_load_ucode_wait(nic)))
		return err;
	if ((err = e100_exec_cb(nic, NULL, e100_configure)))
		return err;
	if ((err = e100_exec_cb(nic, NULL, e100_setup_iaaddr)))
		return err;
	if ((err = e100_exec_cmd(nic, cuc_dump_addr,
		nic->dma_addr + offsetof(struct mem, stats))))
		return err;
	if ((err = e100_exec_cmd(nic, cuc_dump_reset, 0)))
		return err;

	e100_disable_irq(nic);

	return 0;
}

static int e100_multi(struct nic *nic, struct cb *cb, struct sk_buff *skb)
{
	struct net_device *netdev = nic->netdev;
	struct netdev_hw_addr *ha;
	u16 i, count = min(netdev_mc_count(netdev), E100_MAX_MULTICAST_ADDRS);

	cb->command = cpu_to_le16(cb_multi);
	cb->u.multi.count = cpu_to_le16(count * ETH_ALEN);
	i = 0;
	netdev_for_each_mc_addr(ha, netdev) {
		if (i == count)
			break;
		memcpy(&cb->u.multi.addr[i++ * ETH_ALEN], &ha->addr,
			ETH_ALEN);
	}
	return 0;
}

static void e100_set_multicast_list(struct net_device *netdev)
{
	struct nic *nic = netdev_priv(netdev);

	netif_printk(nic, hw, KERN_DEBUG, nic->netdev,
		     "mc_count=%d, flags=0x%04X\n",
		     netdev_mc_count(netdev), netdev->flags);

	if (netdev->flags & IFF_PROMISC)
		nic->flags |= promiscuous;
	else
		nic->flags &= ~promiscuous;

	if (netdev->flags & IFF_ALLMULTI ||
		netdev_mc_count(netdev) > E100_MAX_MULTICAST_ADDRS)
		nic->flags |= multicast_all;
	else
		nic->flags &= ~multicast_all;

	e100_exec_cb(nic, NULL, e100_configure);
	e100_exec_cb(nic, NULL, e100_multi);
}

static void e100_update_stats(struct nic *nic)
{
	struct net_device *dev = nic->netdev;
	struct net_device_stats *ns = &dev->stats;
	struct stats *s = &nic->mem->stats;
	__le32 *complete = (nic->mac < mac_82558_D101_A4) ? &s->fc_xmt_pause :
		(nic->mac < mac_82559_D101M) ? (__le32 *)&s->xmt_tco_frames :
		&s->complete;

	/* Device's stats reporting may take several microseconds to
	 * complete, so we're always waiting for results of the
	 * previous command. */

	if (*complete == cpu_to_le32(cuc_dump_reset_complete)) {
		*complete = 0;
		nic->tx_frames = le32_to_cpu(s->tx_good_frames);
		nic->tx_collisions = le32_to_cpu(s->tx_total_collisions);
		ns->tx_aborted_errors += le32_to_cpu(s->tx_max_collisions);
		ns->tx_window_errors += le32_to_cpu(s->tx_late_collisions);
		ns->tx_carrier_errors += le32_to_cpu(s->tx_lost_crs);
		ns->tx_fifo_errors += le32_to_cpu(s->tx_underruns);
		ns->collisions += nic->tx_collisions;
		ns->tx_errors += le32_to_cpu(s->tx_max_collisions) +
			le32_to_cpu(s->tx_lost_crs);
		nic->rx_short_frame_errors +=
			le32_to_cpu(s->rx_short_frame_errors);
		ns->rx_length_errors = nic->rx_short_frame_errors +
			nic->rx_over_length_errors;
		ns->rx_crc_errors += le32_to_cpu(s->rx_crc_errors);
		ns->rx_frame_errors += le32_to_cpu(s->rx_alignment_errors);
		ns->rx_over_errors += le32_to_cpu(s->rx_overrun_errors);
		ns->rx_fifo_errors += le32_to_cpu(s->rx_overrun_errors);
		ns->rx_missed_errors += le32_to_cpu(s->rx_resource_errors);
		ns->rx_errors += le32_to_cpu(s->rx_crc_errors) +
			le32_to_cpu(s->rx_alignment_errors) +
			le32_to_cpu(s->rx_short_frame_errors) +
			le32_to_cpu(s->rx_cdt_errors);
		nic->tx_deferred += le32_to_cpu(s->tx_deferred);
		nic->tx_single_collisions +=
			le32_to_cpu(s->tx_single_collisions);
		nic->tx_multiple_collisions +=
			le32_to_cpu(s->tx_multiple_collisions);
		if (nic->mac >= mac_82558_D101_A4) {
			nic->tx_fc_pause += le32_to_cpu(s->fc_xmt_pause);
			nic->rx_fc_pause += le32_to_cpu(s->fc_rcv_pause);
			nic->rx_fc_unsupported +=
				le32_to_cpu(s->fc_rcv_unsupported);
			if (nic->mac >= mac_82559_D101M) {
				nic->tx_tco_frames +=
					le16_to_cpu(s->xmt_tco_frames);
				nic->rx_tco_frames +=
					le16_to_cpu(s->rcv_tco_frames);
			}
		}
	}


	if (e100_exec_cmd(nic, cuc_dump_reset, 0))
		netif_printk(nic, tx_err, KERN_DEBUG, nic->netdev,
			     "exec cuc_dump_reset failed\n");
}

static void e100_adjust_adaptive_ifs(struct nic *nic, int speed, int duplex)
{
	/* Adjust inter-frame-spacing (IFS) between two transmits if
	 * we're getting collisions on a half-duplex connection. */

	if (duplex == DUPLEX_HALF) {
		u32 prev = nic->adaptive_ifs;
		u32 min_frames = (speed == SPEED_100) ? 1000 : 100;

		if ((nic->tx_frames / 32 < nic->tx_collisions) &&
		   (nic->tx_frames > min_frames)) {
			if (nic->adaptive_ifs < 60)
				nic->adaptive_ifs += 5;
		} else if (nic->tx_frames < min_frames) {
			if (nic->adaptive_ifs >= 5)
				nic->adaptive_ifs -= 5;
		}
		if (nic->adaptive_ifs != prev)
			e100_exec_cb(nic, NULL, e100_configure);
	}
}

static void e100_watchdog(struct timer_list *t)
{
	struct nic *nic = from_timer(nic, t, watchdog);
	struct ethtool_cmd cmd = { .cmd = ETHTOOL_GSET };
	u32 speed;

	netif_printk(nic, timer, KERN_DEBUG, nic->netdev,
		     "right now = %ld\n", jiffies);

	/* mii library handles link maintenance tasks */

	mii_ethtool_gset(&nic->mii, &cmd);
	speed = ethtool_cmd_speed(&cmd);

	if (mii_link_ok(&nic->mii) && !netif_carrier_ok(nic->netdev)) {
		netdev_info(nic->netdev, "NIC Link is Up %u Mbps %s Duplex\n",
			    speed == SPEED_100 ? 100 : 10,
			    cmd.duplex == DUPLEX_FULL ? "Full" : "Half");
	} else if (!mii_link_ok(&nic->mii) && netif_carrier_ok(nic->netdev)) {
		netdev_info(nic->netdev, "NIC Link is Down\n");
	}

	mii_check_link(&nic->mii);

	/* Software generated interrupt to recover from (rare) Rx
	 * allocation failure.
	 * Unfortunately have to use a spinlock to not re-enable interrupts
	 * accidentally, due to hardware that shares a register between the
	 * interrupt mask bit and the SW Interrupt generation bit */
	spin_lock_irq(&nic->cmd_lock);
	iowrite8(ioread8(&nic->csr->scb.cmd_hi) | irq_sw_gen,&nic->csr->scb.cmd_hi);
	e100_write_flush(nic);
	spin_unlock_irq(&nic->cmd_lock);

	e100_update_stats(nic);
	e100_adjust_adaptive_ifs(nic, speed, cmd.duplex);

	if (nic->mac <= mac_82557_D100_C)
		/* Issue a multicast command to workaround a 557 lock up */
		e100_set_multicast_list(nic->netdev);

	if (nic->flags & ich && speed == SPEED_10 && cmd.duplex == DUPLEX_HALF)
		/* Need SW workaround for ICH[x] 10Mbps/half duplex Tx hang. */
		nic->flags |= ich_10h_workaround;
	else
		nic->flags &= ~ich_10h_workaround;

	mod_timer(&nic->watchdog,
		  round_jiffies(jiffies + E100_WATCHDOG_PERIOD));
}

static int e100_xmit_prepare(struct nic *nic, struct cb *cb,
	struct sk_buff *skb)
{
	dma_addr_t dma_addr;
	cb->command = nic->tx_command;

	dma_addr = dma_map_single(&nic->pdev->dev, skb->data, skb->len,
				  DMA_TO_DEVICE);
	/* If we can't map the skb, have the upper layer try later */
	if (dma_mapping_error(&nic->pdev->dev, dma_addr))
		return -ENOMEM;

	/*
	 * Use the last 4 bytes of the SKB payload packet as the CRC, used for
	 * testing, ie sending frames with bad CRC.
	 */
	if (unlikely(skb->no_fcs))
		cb->command |= cpu_to_le16(cb_tx_nc);
	else
		cb->command &= ~cpu_to_le16(cb_tx_nc);

	/* interrupt every 16 packets regardless of delay */
	if ((nic->cbs_avail & ~15) == nic->cbs_avail)
		cb->command |= cpu_to_le16(cb_i);
	cb->u.tcb.tbd_array = cb->dma_addr + offsetof(struct cb, u.tcb.tbd);
	cb->u.tcb.tcb_byte_count = 0;
	cb->u.tcb.threshold = nic->tx_threshold;
	cb->u.tcb.tbd_count = 1;
	cb->u.tcb.tbd.buf_addr = cpu_to_le32(dma_addr);
	cb->u.tcb.tbd.size = cpu_to_le16(skb->len);
	skb_tx_timestamp(skb);
	return 0;
}

static netdev_tx_t e100_xmit_frame(struct sk_buff *skb,
				   struct net_device *netdev)
{
	struct nic *nic = netdev_priv(netdev);
	int err;

	if (nic->flags & ich_10h_workaround) {
		/* SW workaround for ICH[x] 10Mbps/half duplex Tx hang.
		   Issue a NOP command followed by a 1us delay before
		   issuing the Tx command. */
		if (e100_exec_cmd(nic, cuc_nop, 0))
			netif_printk(nic, tx_err, KERN_DEBUG, nic->netdev,
				     "exec cuc_nop failed\n");
		udelay(1);
	}

	err = e100_exec_cb(nic, skb, e100_xmit_prepare);

	switch (err) {
	case -ENOSPC:
		/* We queued the skb, but now we're out of space. */
		netif_printk(nic, tx_err, KERN_DEBUG, nic->netdev,
			     "No space for CB\n");
		netif_stop_queue(netdev);
		break;
	case -ENOMEM:
		/* This is a hard error - log it. */
		netif_printk(nic, tx_err, KERN_DEBUG, nic->netdev,
			     "Out of Tx resources, returning skb\n");
		netif_stop_queue(netdev);
		return NETDEV_TX_BUSY;
	}

	return NETDEV_TX_OK;
}

static int e100_tx_clean(struct nic *nic)
{
	struct net_device *dev = nic->netdev;
	struct cb *cb;
	int tx_cleaned = 0;

	spin_lock(&nic->cb_lock);

	/* Clean CBs marked complete */
	for (cb = nic->cb_to_clean;
	    cb->status & cpu_to_le16(cb_complete);
	    cb = nic->cb_to_clean = cb->next) {
		dma_rmb(); /* read skb after status */
		netif_printk(nic, tx_done, KERN_DEBUG, nic->netdev,
			     "cb[%d]->status = 0x%04X\n",
			     (int)(((void*)cb - (void*)nic->cbs)/sizeof(struct cb)),
			     cb->status);

		if (likely(cb->skb != NULL)) {
			dev->stats.tx_packets++;
			dev->stats.tx_bytes += cb->skb->len;

			dma_unmap_single(&nic->pdev->dev,
					 le32_to_cpu(cb->u.tcb.tbd.buf_addr),
					 le16_to_cpu(cb->u.tcb.tbd.size),
					 DMA_TO_DEVICE);
			dev_kfree_skb_any(cb->skb);
			cb->skb = NULL;
			tx_cleaned = 1;
		}
		cb->status = 0;
		nic->cbs_avail++;
	}

	spin_unlock(&nic->cb_lock);

	/* Recover from running out of Tx resources in xmit_frame */
	if (unlikely(tx_cleaned && netif_queue_stopped(nic->netdev)))
		netif_wake_queue(nic->netdev);

	return tx_cleaned;
}

static void e100_clean_cbs(struct nic *nic)
{
	if (nic->cbs) {
		while (nic->cbs_avail != nic->params.cbs.count) {
			struct cb *cb = nic->cb_to_clean;
			if (cb->skb) {
				dma_unmap_single(&nic->pdev->dev,
						 le32_to_cpu(cb->u.tcb.tbd.buf_addr),
						 le16_to_cpu(cb->u.tcb.tbd.size),
						 DMA_TO_DEVICE);
				dev_kfree_skb(cb->skb);
			}
			nic->cb_to_clean = nic->cb_to_clean->next;
			nic->cbs_avail++;
		}
		dma_pool_free(nic->cbs_pool, nic->cbs, nic->cbs_dma_addr);
		nic->cbs = NULL;
		nic->cbs_avail = 0;
	}
	nic->cuc_cmd = cuc_start;
	nic->cb_to_use = nic->cb_to_send = nic->cb_to_clean =
		nic->cbs;
}

static int e100_alloc_cbs(struct nic *nic)
{
	struct cb *cb;
	unsigned int i, count = nic->params.cbs.count;

	nic->cuc_cmd = cuc_start;
	nic->cb_to_use = nic->cb_to_send = nic->cb_to_clean = NULL;
	nic->cbs_avail = 0;

	nic->cbs = dma_pool_zalloc(nic->cbs_pool, GFP_KERNEL,
				   &nic->cbs_dma_addr);
	if (!nic->cbs)
		return -ENOMEM;

	for (cb = nic->cbs, i = 0; i < count; cb++, i++) {
		cb->next = (i + 1 < count) ? cb + 1 : nic->cbs;
		cb->prev = (i == 0) ? nic->cbs + count - 1 : cb - 1;

		cb->dma_addr = nic->cbs_dma_addr + i * sizeof(struct cb);
		cb->link = cpu_to_le32(nic->cbs_dma_addr +
			((i+1) % count) * sizeof(struct cb));
	}

	nic->cb_to_use = nic->cb_to_send = nic->cb_to_clean = nic->cbs;
	nic->cbs_avail = count;

	return 0;
}

static inline void e100_start_receiver(struct nic *nic, struct rx *rx)
{
	if (!nic->rxs) return;
	if (RU_SUSPENDED != nic->ru_running) return;

	/* handle init time starts */
	if (!rx) rx = nic->rxs;

	/* (Re)start RU if suspended or idle and RFA is non-NULL */
	if (rx->skb) {
		e100_exec_cmd(nic, ruc_start, rx->dma_addr);
		nic->ru_running = RU_RUNNING;
	}
}

#define RFD_BUF_LEN (sizeof(struct rfd) + VLAN_ETH_FRAME_LEN + ETH_FCS_LEN)
static int e100_rx_alloc_skb(struct nic *nic, struct rx *rx)
{
	if (!(rx->skb = netdev_alloc_skb_ip_align(nic->netdev, RFD_BUF_LEN)))
		return -ENOMEM;

	/* Init, and map the RFD. */
	skb_copy_to_linear_data(rx->skb, &nic->blank_rfd, sizeof(struct rfd));
	rx->dma_addr = dma_map_single(&nic->pdev->dev, rx->skb->data,
				      RFD_BUF_LEN, DMA_BIDIRECTIONAL);

	if (dma_mapping_error(&nic->pdev->dev, rx->dma_addr)) {
		dev_kfree_skb_any(rx->skb);
		rx->skb = NULL;
		rx->dma_addr = 0;
		return -ENOMEM;
	}

	/* Link the RFD to end of RFA by linking previous RFD to
	 * this one.  We are safe to touch the previous RFD because
	 * it is protected by the before last buffer's el bit being set */
	if (rx->prev->skb) {
		struct rfd *prev_rfd = (struct rfd *)rx->prev->skb->data;
		put_unaligned_le32(rx->dma_addr, &prev_rfd->link);
		dma_sync_single_for_device(&nic->pdev->dev,
					   rx->prev->dma_addr,
					   sizeof(struct rfd),
					   DMA_BIDIRECTIONAL);
	}

	return 0;
}

static int e100_rx_indicate(struct nic *nic, struct rx *rx,
	unsigned int *work_done, unsigned int work_to_do)
{
	struct net_device *dev = nic->netdev;
	struct sk_buff *skb = rx->skb;
	struct rfd *rfd = (struct rfd *)skb->data;
	u16 rfd_status, actual_size;
	u16 fcs_pad = 0;

	if (unlikely(work_done && *work_done >= work_to_do))
		return -EAGAIN;

	/* Need to sync before taking a peek at cb_complete bit */
	dma_sync_single_for_cpu(&nic->pdev->dev, rx->dma_addr,
				sizeof(struct rfd), DMA_BIDIRECTIONAL);
	rfd_status = le16_to_cpu(rfd->status);

	netif_printk(nic, rx_status, KERN_DEBUG, nic->netdev,
		     "status=0x%04X\n", rfd_status);
	dma_rmb(); /* read size after status bit */

	/* If data isn't ready, nothing to indicate */
	if (unlikely(!(rfd_status & cb_complete))) {
		/* If the next buffer has the el bit, but we think the receiver
		 * is still running, check to see if it really stopped while
		 * we had interrupts off.
		 * This allows for a fast restart without re-enabling
		 * interrupts */
		if ((le16_to_cpu(rfd->command) & cb_el) &&
		    (RU_RUNNING == nic->ru_running))

			if (ioread8(&nic->csr->scb.status) & rus_no_res)
				nic->ru_running = RU_SUSPENDED;
		dma_sync_single_for_device(&nic->pdev->dev, rx->dma_addr,
					   sizeof(struct rfd),
					   DMA_FROM_DEVICE);
		return -ENODATA;
	}

	/* Get actual data size */
	if (unlikely(dev->features & NETIF_F_RXFCS))
		fcs_pad = 4;
	actual_size = le16_to_cpu(rfd->actual_size) & 0x3FFF;
	if (unlikely(actual_size > RFD_BUF_LEN - sizeof(struct rfd)))
		actual_size = RFD_BUF_LEN - sizeof(struct rfd);

	/* Get data */
	dma_unmap_single(&nic->pdev->dev, rx->dma_addr, RFD_BUF_LEN,
			 DMA_BIDIRECTIONAL);

	/* If this buffer has the el bit, but we think the receiver
	 * is still running, check to see if it really stopped while
	 * we had interrupts off.
	 * This allows for a fast restart without re-enabling interrupts.
	 * This can happen when the RU sees the size change but also sees
	 * the el bit set. */
	if ((le16_to_cpu(rfd->command) & cb_el) &&
	    (RU_RUNNING == nic->ru_running)) {

	    if (ioread8(&nic->csr->scb.status) & rus_no_res)
		nic->ru_running = RU_SUSPENDED;
	}

	/* Pull off the RFD and put the actual data (minus eth hdr) */
	skb_reserve(skb, sizeof(struct rfd));
	skb_put(skb, actual_size);
	skb->protocol = eth_type_trans(skb, nic->netdev);

	/* If we are receiving all frames, then don't bother
	 * checking for errors.
	 */
	if (unlikely(dev->features & NETIF_F_RXALL)) {
		if (actual_size > ETH_DATA_LEN + VLAN_ETH_HLEN + fcs_pad)
			/* Received oversized frame, but keep it. */
			nic->rx_over_length_errors++;
		goto process_skb;
	}

	if (unlikely(!(rfd_status & cb_ok))) {
		/* Don't indicate if hardware indicates errors */
		dev_kfree_skb_any(skb);
	} else if (actual_size > ETH_DATA_LEN + VLAN_ETH_HLEN + fcs_pad) {
		/* Don't indicate oversized frames */
		nic->rx_over_length_errors++;
		dev_kfree_skb_any(skb);
	} else {
process_skb:
		dev->stats.rx_packets++;
		dev->stats.rx_bytes += (actual_size - fcs_pad);
		netif_receive_skb(skb);
		if (work_done)
			(*work_done)++;
	}

	rx->skb = NULL;

	return 0;
}

static void e100_rx_clean(struct nic *nic, unsigned int *work_done,
	unsigned int work_to_do)
{
	struct rx *rx;
	int restart_required = 0, err = 0;
	struct rx *old_before_last_rx, *new_before_last_rx;
	struct rfd *old_before_last_rfd, *new_before_last_rfd;

	/* Indicate newly arrived packets */
	for (rx = nic->rx_to_clean; rx->skb; rx = nic->rx_to_clean = rx->next) {
		err = e100_rx_indicate(nic, rx, work_done, work_to_do);
		/* Hit quota or no more to clean */
		if (-EAGAIN == err || -ENODATA == err)
			break;
	}


	/* On EAGAIN, hit quota so have more work to do, restart once
	 * cleanup is complete.
	 * Else, are we already rnr? then pay attention!!! this ensures that
	 * the state machine progression never allows a start with a
	 * partially cleaned list, avoiding a race between hardware
	 * and rx_to_clean when in NAPI mode */
	if (-EAGAIN != err && RU_SUSPENDED == nic->ru_running)
		restart_required = 1;

	old_before_last_rx = nic->rx_to_use->prev->prev;
	old_before_last_rfd = (struct rfd *)old_before_last_rx->skb->data;

	/* Alloc new skbs to refill list */
	for (rx = nic->rx_to_use; !rx->skb; rx = nic->rx_to_use = rx->next) {
		if (unlikely(e100_rx_alloc_skb(nic, rx)))
			break; /* Better luck next time (see watchdog) */
	}

	new_before_last_rx = nic->rx_to_use->prev->prev;
	if (new_before_last_rx != old_before_last_rx) {
		/* Set the el-bit on the buffer that is before the last buffer.
		 * This lets us update the next pointer on the last buffer
		 * without worrying about hardware touching it.
		 * We set the size to 0 to prevent hardware from touching this
		 * buffer.
		 * When the hardware hits the before last buffer with el-bit
		 * and size of 0, it will RNR interrupt, the RUS will go into
		 * the No Resources state.  It will not complete nor write to
		 * this buffer. */
		new_before_last_rfd =
			(struct rfd *)new_before_last_rx->skb->data;
		new_before_last_rfd->size = 0;
		new_before_last_rfd->command |= cpu_to_le16(cb_el);
		dma_sync_single_for_device(&nic->pdev->dev,
					   new_before_last_rx->dma_addr,
					   sizeof(struct rfd),
					   DMA_BIDIRECTIONAL);

		/* Now that we have a new stopping point, we can clear the old
		 * stopping point.  We must sync twice to get the proper
		 * ordering on the hardware side of things. */
		old_before_last_rfd->command &= ~cpu_to_le16(cb_el);
		dma_sync_single_for_device(&nic->pdev->dev,
					   old_before_last_rx->dma_addr,
					   sizeof(struct rfd),
					   DMA_BIDIRECTIONAL);
		old_before_last_rfd->size = cpu_to_le16(VLAN_ETH_FRAME_LEN
							+ ETH_FCS_LEN);
		dma_sync_single_for_device(&nic->pdev->dev,
					   old_before_last_rx->dma_addr,
					   sizeof(struct rfd),
					   DMA_BIDIRECTIONAL);
	}

	if (restart_required) {
		// ack the rnr?
		iowrite8(stat_ack_rnr, &nic->csr->scb.stat_ack);
		e100_start_receiver(nic, nic->rx_to_clean);
		if (work_done)
			(*work_done)++;
	}
}

static void e100_rx_clean_list(struct nic *nic)
{
	struct rx *rx;
	unsigned int i, count = nic->params.rfds.count;

	nic->ru_running = RU_UNINITIALIZED;

	if (nic->rxs) {
		for (rx = nic->rxs, i = 0; i < count; rx++, i++) {
			if (rx->skb) {
				dma_unmap_single(&nic->pdev->dev,
						 rx->dma_addr, RFD_BUF_LEN,
						 DMA_BIDIRECTIONAL);
				dev_kfree_skb(rx->skb);
			}
		}
		kfree(nic->rxs);
		nic->rxs = NULL;
	}

	nic->rx_to_use = nic->rx_to_clean = NULL;
}

static int e100_rx_alloc_list(struct nic *nic)
{
	struct rx *rx;
	unsigned int i, count = nic->params.rfds.count;
	struct rfd *before_last;

	nic->rx_to_use = nic->rx_to_clean = NULL;
	nic->ru_running = RU_UNINITIALIZED;

	if (!(nic->rxs = kcalloc(count, sizeof(struct rx), GFP_KERNEL)))
		return -ENOMEM;

	for (rx = nic->rxs, i = 0; i < count; rx++, i++) {
		rx->next = (i + 1 < count) ? rx + 1 : nic->rxs;
		rx->prev = (i == 0) ? nic->rxs + count - 1 : rx - 1;
		if (e100_rx_alloc_skb(nic, rx)) {
			e100_rx_clean_list(nic);
			return -ENOMEM;
		}
	}
	/* Set the el-bit on the buffer that is before the last buffer.
	 * This lets us update the next pointer on the last buffer without
	 * worrying about hardware touching it.
	 * We set the size to 0 to prevent hardware from touching this buffer.
	 * When the hardware hits the before last buffer with el-bit and size
	 * of 0, it will RNR interrupt, the RU will go into the No Resources
	 * state.  It will not complete nor write to this buffer. */
	rx = nic->rxs->prev->prev;
	before_last = (struct rfd *)rx->skb->data;
	before_last->command |= cpu_to_le16(cb_el);
	before_last->size = 0;
	dma_sync_single_for_device(&nic->pdev->dev, rx->dma_addr,
				   sizeof(struct rfd), DMA_BIDIRECTIONAL);

	nic->rx_to_use = nic->rx_to_clean = nic->rxs;
	nic->ru_running = RU_SUSPENDED;

	return 0;
}

static irqreturn_t e100_intr(int irq, void *dev_id)
{
	struct net_device *netdev = dev_id;
	struct nic *nic = netdev_priv(netdev);
	u8 stat_ack = ioread8(&nic->csr->scb.stat_ack);

	netif_printk(nic, intr, KERN_DEBUG, nic->netdev,
		     "stat_ack = 0x%02X\n", stat_ack);

	if (stat_ack == stat_ack_not_ours ||	/* Not our interrupt */
	   stat_ack == stat_ack_not_present)	/* Hardware is ejected */
		return IRQ_NONE;

	/* Ack interrupt(s) */
	iowrite8(stat_ack, &nic->csr->scb.stat_ack);

	/* We hit Receive No Resource (RNR); restart RU after cleaning */
	if (stat_ack & stat_ack_rnr)
		nic->ru_running = RU_SUSPENDED;

	if (likely(napi_schedule_prep(&nic->napi))) {
		e100_disable_irq(nic);
		__napi_schedule(&nic->napi);
	}

	return IRQ_HANDLED;
}

static int e100_poll(struct napi_struct *napi, int budget)
{
	struct nic *nic = container_of(napi, struct nic, napi);
	unsigned int work_done = 0;

	e100_rx_clean(nic, &work_done, budget);
	e100_tx_clean(nic);

	/* If budget fully consumed, continue polling */
	if (work_done == budget)
		return budget;

	/* only re-enable interrupt if stack agrees polling is really done */
	if (likely(napi_complete_done(napi, work_done)))
		e100_enable_irq(nic);

	return work_done;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void e100_netpoll(struct net_device *netdev)
{
	struct nic *nic = netdev_priv(netdev);

	e100_disable_irq(nic);
	e100_intr(nic->pdev->irq, netdev);
	e100_tx_clean(nic);
	e100_enable_irq(nic);
}
#endif

static int e100_set_mac_address(struct net_device *netdev, void *p)
{
	struct nic *nic = netdev_priv(netdev);
	struct sockaddr *addr = p;

	if (!is_valid_ether_addr(addr->sa_data))
		return -EADDRNOTAVAIL;

	eth_hw_addr_set(netdev, addr->sa_data);
	e100_exec_cb(nic, NULL, e100_setup_iaaddr);

	return 0;
}

static int e100_asf(struct nic *nic)
{
	/* ASF can be enabled from eeprom */
	return (nic->pdev->device >= 0x1050) && (nic->pdev->device <= 0x1057) &&
	   (le16_to_cpu(nic->eeprom[eeprom_config_asf]) & eeprom_asf) &&
	   !(le16_to_cpu(nic->eeprom[eeprom_config_asf]) & eeprom_gcl) &&
	   ((le16_to_cpu(nic->eeprom[eeprom_smbus_addr]) & 0xFF) != 0xFE);
}

static int e100_up(struct nic *nic)
{
	int err;

	if ((err = e100_rx_alloc_list(nic)))
		return err;
	if ((err = e100_alloc_cbs(nic)))
		goto err_rx_clean_list;
	if ((err = e100_hw_init(nic)))
		goto err_clean_cbs;
	e100_set_multicast_list(nic->netdev);
	e100_start_receiver(nic, NULL);
	mod_timer(&nic->watchdog, jiffies);
	if ((err = request_irq(nic->pdev->irq, e100_intr, IRQF_SHARED,
		nic->netdev->name, nic->netdev)))
		goto err_no_irq;
	netif_wake_queue(nic->netdev);
	napi_enable(&nic->napi);
	/* enable ints _after_ enabling poll, preventing a race between
	 * disable ints+schedule */
	e100_enable_irq(nic);
	return 0;

err_no_irq:
	del_timer_sync(&nic->watchdog);
err_clean_cbs:
	e100_clean_cbs(nic);
err_rx_clean_list:
	e100_rx_clean_list(nic);
	return err;
}

static void e100_down(struct nic *nic)
{
	/* wait here for poll to complete */
	napi_disable(&nic->napi);
	netif_stop_queue(nic->netdev);
	e100_hw_reset(nic);
	free_irq(nic->pdev->irq, nic->netdev);
	del_timer_sync(&nic->watchdog);
	netif_carrier_off(nic->netdev);
	e100_clean_cbs(nic);
	e100_rx_clean_list(nic);
}

static void e100_tx_timeout(struct net_device *netdev, unsigned int txqueue)
{
	struct nic *nic = netdev_priv(netdev);

	/* Reset outside of interrupt context, to avoid request_irq
	 * in interrupt context */
	schedule_work(&nic->tx_timeout_task);
}

static void e100_tx_timeout_task(struct work_struct *work)
{
	struct nic *nic = container_of(work, struct nic, tx_timeout_task);
	struct net_device *netdev = nic->netdev;

	netif_printk(nic, tx_err, KERN_DEBUG, nic->netdev,
		     "scb.status=0x%02X\n", ioread8(&nic->csr->scb.status));

	rtnl_lock();
	if (netif_running(netdev)) {
		e100_down(netdev_priv(netdev));
		e100_up(netdev_priv(netdev));
	}
	rtnl_unlock();
}

static int e100_loopback_test(struct nic *nic, enum loopback loopback_mode)
{
	int err;
	struct sk_buff *skb;

	/* Use driver resources to perform internal MAC or PHY
	 * loopback test.  A single packet is prepared and transmitted
	 * in loopback mode, and the test passes if the received
	 * packet compares byte-for-byte to the transmitted packet. */

	if ((err = e100_rx_alloc_list(nic)))
		return err;
	if ((err = e100_alloc_cbs(nic)))
		goto err_clean_rx;

	/* ICH PHY loopback is broken so do MAC loopback instead */
	if (nic->flags & ich && loopback_mode == lb_phy)
		loopback_mode = lb_mac;

	nic->loopback = loopback_mode;
	if ((err = e100_hw_init(nic)))
		goto err_loopback_none;

	if (loopback_mode == lb_phy)
		mdio_write(nic->netdev, nic->mii.phy_id, MII_BMCR,
			BMCR_LOOPBACK);

	e100_start_receiver(nic, NULL);

	if (!(skb = netdev_alloc_skb(nic->netdev, ETH_DATA_LEN))) {
		err = -ENOMEM;
		goto err_loopback_none;
	}
	skb_put(skb, ETH_DATA_LEN);
	memset(skb->data, 0xFF, ETH_DATA_LEN);
	e100_xmit_frame(skb, nic->netdev);

	msleep(10);

	dma_sync_single_for_cpu(&nic->pdev->dev, nic->rx_to_clean->dma_addr,
				RFD_BUF_LEN, DMA_BIDIRECTIONAL);

	if (memcmp(nic->rx_to_clean->skb->data + sizeof(struct rfd),
	   skb->data, ETH_DATA_LEN))
		err = -EAGAIN;

err_loopback_none:
	mdio_write(nic->netdev, nic->mii.phy_id, MII_BMCR, 0);
	nic->loopback = lb_none;
	e100_clean_cbs(nic);
	e100_hw_reset(nic);
err_clean_rx:
	e100_rx_clean_list(nic);
	return err;
}

#define MII_LED_CONTROL	0x1B
#define E100_82552_LED_OVERRIDE 0x19
#define E100_82552_LED_ON       0x000F /* LEDTX and LED_RX both on */
#define E100_82552_LED_OFF      0x000A /* LEDTX and LED_RX both off */

static int e100_get_link_ksettings(struct net_device *netdev,
				   struct ethtool_link_ksettings *cmd)
{
	struct nic *nic = netdev_priv(netdev);

	mii_ethtool_get_link_ksettings(&nic->mii, cmd);

	return 0;
}

static int e100_set_link_ksettings(struct net_device *netdev,
				   const struct ethtool_link_ksettings *cmd)
{
	struct nic *nic = netdev_priv(netdev);
	int err;

	mdio_write(netdev, nic->mii.phy_id, MII_BMCR, BMCR_RESET);
	err = mii_ethtool_set_link_ksettings(&nic->mii, cmd);
	e100_exec_cb(nic, NULL, e100_configure);

	return err;
}

static void e100_get_drvinfo(struct net_device *netdev,
	struct ethtool_drvinfo *info)
{
	struct nic *nic = netdev_priv(netdev);
	strscpy(info->driver, DRV_NAME, sizeof(info->driver));
	strscpy(info->bus_info, pci_name(nic->pdev),
		sizeof(info->bus_info));
}

#define E100_PHY_REGS 0x1D
static int e100_get_regs_len(struct net_device *netdev)
{
	struct nic *nic = netdev_priv(netdev);

	/* We know the number of registers, and the size of the dump buffer.
	 * Calculate the total size in bytes.
	 */
	return (1 + E100_PHY_REGS) * sizeof(u32) + sizeof(nic->mem->dump_buf);
}

static void e100_get_regs(struct net_device *netdev,
	struct ethtool_regs *regs, void *p)
{
	struct nic *nic = netdev_priv(netdev);
	u32 *buff = p;
	int i;

	regs->version = (1 << 24) | nic->pdev->revision;
	buff[0] = ioread8(&nic->csr->scb.cmd_hi) << 24 |
		ioread8(&nic->csr->scb.cmd_lo) << 16 |
		ioread16(&nic->csr->scb.status);
	for (i = 0; i < E100_PHY_REGS; i++)
		/* Note that we read the registers in reverse order. This
		 * ordering is the ABI apparently used by ethtool and other
		 * applications.
		 */
		buff[1 + i] = mdio_read(netdev, nic->mii.phy_id,
					E100_PHY_REGS - 1 - i);
	memset(nic->mem->dump_buf, 0, sizeof(nic->mem->dump_buf));
	e100_exec_cb(nic, NULL, e100_dump);
	msleep(10);
	memcpy(&buff[1 + E100_PHY_REGS], nic->mem->dump_buf,
	       sizeof(nic->mem->dump_buf));
}

static void e100_get_wol(struct net_device *netdev, struct ethtool_wolinfo *wol)
{
	struct nic *nic = netdev_priv(netdev);
	wol->supported = (nic->mac >= mac_82558_D101_A4) ?  WAKE_MAGIC : 0;
	wol->wolopts = (nic->flags & wol_magic) ? WAKE_MAGIC : 0;
}

static int e100_set_wol(struct net_device *netdev, struct ethtool_wolinfo *wol)
{
	struct nic *nic = netdev_priv(netdev);

	if ((wol->wolopts && wol->wolopts != WAKE_MAGIC) ||
	    !device_can_wakeup(&nic->pdev->dev))
		return -EOPNOTSUPP;

	if (wol->wolopts)
		nic->flags |= wol_magic;
	else
		nic->flags &= ~wol_magic;

	device_set_wakeup_enable(&nic->pdev->dev, wol->wolopts);

	e100_exec_cb(nic, NULL, e100_configure);

	return 0;
}

static u32 e100_get_msglevel(struct net_device *netdev)
{
	struct nic *nic = netdev_priv(netdev);
	return nic->msg_enable;
}

static void e100_set_msglevel(struct net_device *netdev, u32 value)
{
	struct nic *nic = netdev_priv(netdev);
	nic->msg_enable = value;
}

static int e100_nway_reset(struct net_device *netdev)
{
	struct nic *nic = netdev_priv(netdev);
	return mii_nway_restart(&nic->mii);
}

static u32 e100_get_link(struct net_device *netdev)
{
	struct nic *nic = netdev_priv(netdev);
	return mii_link_ok(&nic->mii);
}

static int e100_get_eeprom_len(struct net_device *netdev)
{
	struct nic *nic = netdev_priv(netdev);
	return nic->eeprom_wc << 1;
}

#define E100_EEPROM_MAGIC	0x1234
static int e100_get_eeprom(struct net_device *netdev,
	struct ethtool_eeprom *eeprom, u8 *bytes)
{
	struct nic *nic = netdev_priv(netdev);

	eeprom->magic = E100_EEPROM_MAGIC;
	memcpy(bytes, &((u8 *)nic->eeprom)[eeprom->offset], eeprom->len);

	return 0;
}

static int e100_set_eeprom(struct net_device *netdev,
	struct ethtool_eeprom *eeprom, u8 *bytes)
{
	struct nic *nic = netdev_priv(netdev);

	if (eeprom->magic != E100_EEPROM_MAGIC)
		return -EINVAL;

	memcpy(&((u8 *)nic->eeprom)[eeprom->offset], bytes, eeprom->len);

	return e100_eeprom_save(nic, eeprom->offset >> 1,
		(eeprom->len >> 1) + 1);
}

static void e100_get_ringparam(struct net_device *netdev,
			       struct ethtool_ringparam *ring,
			       struct kernel_ethtool_ringparam *kernel_ring,
			       struct netlink_ext_ack *extack)
{
	struct nic *nic = netdev_priv(netdev);
	struct param_range *rfds = &nic->params.rfds;
	struct param_range *cbs = &nic->params.cbs;

	ring->rx_max_pending = rfds->max;
	ring->tx_max_pending = cbs->max;
	ring->rx_pending = rfds->count;
	ring->tx_pending = cbs->count;
}

static int e100_set_ringparam(struct net_device *netdev,
			      struct ethtool_ringparam *ring,
			      struct kernel_ethtool_ringparam *kernel_ring,
			      struct netlink_ext_ack *extack)
{
	struct nic *nic = netdev_priv(netdev);
	struct param_range *rfds = &nic->params.rfds;
	struct param_range *cbs = &nic->params.cbs;

	if ((ring->rx_mini_pending) || (ring->rx_jumbo_pending))
		return -EINVAL;

	if (netif_running(netdev))
		e100_down(nic);
	rfds->count = max(ring->rx_pending, rfds->min);
	rfds->count = min(rfds->count, rfds->max);
	cbs->count = max(ring->tx_pending, cbs->min);
	cbs->count = min(cbs->count, cbs->max);
	netif_info(nic, drv, nic->netdev, "Ring Param settings: rx: %d, tx %d\n",
		   rfds->count, cbs->count);
	if (netif_running(netdev))
		e100_up(nic);

	return 0;
}

static const char e100_gstrings_test[][ETH_GSTRING_LEN] = {
	"Link test     (on/offline)",
	"Eeprom test   (on/offline)",
	"Self test        (offline)",
	"Mac loopback     (offline)",
	"Phy loopback     (offline)",
};
#define E100_TEST_LEN	ARRAY_SIZE(e100_gstrings_test)

static void e100_diag_test(struct net_device *netdev,
	struct ethtool_test *test, u64 *data)
{
	struct ethtool_cmd cmd;
	struct nic *nic = netdev_priv(netdev);
	int i;

	memset(data, 0, E100_TEST_LEN * sizeof(u64));
	data[0] = !mii_link_ok(&nic->mii);
	data[1] = e100_eeprom_load(nic);
	if (test->flags & ETH_TEST_FL_OFFLINE) {

		/* save speed, duplex & autoneg settings */
		mii_ethtool_gset(&nic->mii, &cmd);

		if (netif_running(netdev))
			e100_down(nic);
		data[2] = e100_self_test(nic);
		data[3] = e100_loopback_test(nic, lb_mac);
		data[4] = e100_loopback_test(nic, lb_phy);

		/* restore speed, duplex & autoneg settings */
		mii_ethtool_sset(&nic->mii, &cmd);

		if (netif_running(netdev))
			e100_up(nic);
	}
	for (i = 0; i < E100_TEST_LEN; i++)
		test->flags |= data[i] ? ETH_TEST_FL_FAILED : 0;

	msleep_interruptible(4 * 1000);
}

static int e100_set_phys_id(struct net_device *netdev,
			    enum ethtool_phys_id_state state)
{
	struct nic *nic = netdev_priv(netdev);
	enum led_state {
		led_on     = 0x01,
		led_off    = 0x04,
		led_on_559 = 0x05,
		led_on_557 = 0x07,
	};
	u16 led_reg = (nic->phy == phy_82552_v) ? E100_82552_LED_OVERRIDE :
		MII_LED_CONTROL;
	u16 leds = 0;

	switch (state) {
	case ETHTOOL_ID_ACTIVE:
		return 2;

	case ETHTOOL_ID_ON:
		leds = (nic->phy == phy_82552_v) ? E100_82552_LED_ON :
		       (nic->mac < mac_82559_D101M) ? led_on_557 : led_on_559;
		break;

	case ETHTOOL_ID_OFF:
		leds = (nic->phy == phy_82552_v) ? E100_82552_LED_OFF : led_off;
		break;

	case ETHTOOL_ID_INACTIVE:
		break;
	}

	mdio_write(netdev, nic->mii.phy_id, led_reg, leds);
	return 0;
}

static const char e100_gstrings_stats[][ETH_GSTRING_LEN] = {
	"rx_packets", "tx_packets", "rx_bytes", "tx_bytes", "rx_errors",
	"tx_errors", "rx_dropped", "tx_dropped", "multicast", "collisions",
	"rx_length_errors", "rx_over_errors", "rx_crc_errors",
	"rx_frame_errors", "rx_fifo_errors", "rx_missed_errors",
	"tx_aborted_errors", "tx_carrier_errors", "tx_fifo_errors",
	"tx_heartbeat_errors", "tx_window_errors",
	/* device-specific stats */
	"tx_deferred", "tx_single_collisions", "tx_multi_collisions",
	"tx_flow_control_pause", "rx_flow_control_pause",
	"rx_flow_control_unsupported", "tx_tco_packets", "rx_tco_packets",
	"rx_short_frame_errors", "rx_over_length_errors",
};
#define E100_NET_STATS_LEN	21
#define E100_STATS_LEN	ARRAY_SIZE(e100_gstrings_stats)

static int e100_get_sset_count(struct net_device *netdev, int sset)
{
	switch (sset) {
	case ETH_SS_TEST:
		return E100_TEST_LEN;
	case ETH_SS_STATS:
		return E100_STATS_LEN;
	default:
		return -EOPNOTSUPP;
	}
}

static void e100_get_ethtool_stats(struct net_device *netdev,
	struct ethtool_stats *stats, u64 *data)
{
	struct nic *nic = netdev_priv(netdev);
	int i;

	for (i = 0; i < E100_NET_STATS_LEN; i++)
		data[i] = ((unsigned long *)&netdev->stats)[i];

	data[i++] = nic->tx_deferred;
	data[i++] = nic->tx_single_collisions;
	data[i++] = nic->tx_multiple_collisions;
	data[i++] = nic->tx_fc_pause;
	data[i++] = nic->rx_fc_pause;
	data[i++] = nic->rx_fc_unsupported;
	data[i++] = nic->tx_tco_frames;
	data[i++] = nic->rx_tco_frames;
	data[i++] = nic->rx_short_frame_errors;
	data[i++] = nic->rx_over_length_errors;
}

static void e100_get_strings(struct net_device *netdev, u32 stringset, u8 *data)
{
	switch (stringset) {
	case ETH_SS_TEST:
		memcpy(data, e100_gstrings_test, sizeof(e100_gstrings_test));
		break;
	case ETH_SS_STATS:
		memcpy(data, e100_gstrings_stats, sizeof(e100_gstrings_stats));
		break;
	}
}

static const struct ethtool_ops e100_ethtool_ops = {
	.get_drvinfo		= e100_get_drvinfo,
	.get_regs_len		= e100_get_regs_len,
	.get_regs		= e100_get_regs,
	.get_wol		= e100_get_wol,
	.set_wol		= e100_set_wol,
	.get_msglevel		= e100_get_msglevel,
	.set_msglevel		= e100_set_msglevel,
	.nway_reset		= e100_nway_reset,
	.get_link		= e100_get_link,
	.get_eeprom_len		= e100_get_eeprom_len,
	.get_eeprom		= e100_get_eeprom,
	.set_eeprom		= e100_set_eeprom,
	.get_ringparam		= e100_get_ringparam,
	.set_ringparam		= e100_set_ringparam,
	.self_test		= e100_diag_test,
	.get_strings		= e100_get_strings,
	.set_phys_id		= e100_set_phys_id,
	.get_ethtool_stats	= e100_get_ethtool_stats,
	.get_sset_count		= e100_get_sset_count,
	.get_ts_info		= ethtool_op_get_ts_info,
	.get_link_ksettings	= e100_get_link_ksettings,
	.set_link_ksettings	= e100_set_link_ksettings,
};

static int e100_do_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
{
	struct nic *nic = netdev_priv(netdev);

	return generic_mii_ioctl(&nic->mii, if_mii(ifr), cmd, NULL);
}

static int e100_alloc(struct nic *nic)
{
	nic->mem = dma_alloc_coherent(&nic->pdev->dev, sizeof(struct mem),
				      &nic->dma_addr, GFP_KERNEL);
	return nic->mem ? 0 : -ENOMEM;
}

static void e100_free(struct nic *nic)
{
	if (nic->mem) {
		dma_free_coherent(&nic->pdev->dev, sizeof(struct mem),
				  nic->mem, nic->dma_addr);
		nic->mem = NULL;
	}
}

static int e100_open(struct net_device *netdev)
{
	struct nic *nic = netdev_priv(netdev);
	int err = 0;

	netif_carrier_off(netdev);
	if ((err = e100_up(nic)))
		netif_err(nic, ifup, nic->netdev, "Cannot open interface, aborting\n");
	return err;
}

static int e100_close(struct net_device *netdev)
{
	e100_down(netdev_priv(netdev));
	return 0;
}

static int e100_set_features(struct net_device *netdev,
			     netdev_features_t features)
{
	struct nic *nic = netdev_priv(netdev);
	netdev_features_t changed = features ^ netdev->features;

	if (!(changed & (NETIF_F_RXFCS | NETIF_F_RXALL)))
		return 0;

	netdev->features = features;
	e100_exec_cb(nic, NULL, e100_configure);
	return 1;
}

static const struct net_device_ops e100_netdev_ops = {
	.ndo_open		= e100_open,
	.ndo_stop		= e100_close,
	.ndo_start_xmit		= e100_xmit_frame,
	.ndo_validate_addr	= eth_validate_addr,
	.ndo_set_rx_mode	= e100_set_multicast_list,
	.ndo_set_mac_address	= e100_set_mac_address,
	.ndo_eth_ioctl		= e100_do_ioctl,
	.ndo_tx_timeout		= e100_tx_timeout,
#ifdef CONFIG_NET_POLL_CONTROLLER
	.ndo_poll_controller	= e100_netpoll,
#endif
	.ndo_set_features	= e100_set_features,
};

static int e100_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
	struct net_device *netdev;
	struct nic *nic;
	int err;

	if (!(netdev = alloc_etherdev(sizeof(struct nic))))
		return -ENOMEM;

	netdev->hw_features |= NETIF_F_RXFCS;
	netdev->priv_flags |= IFF_SUPP_NOFCS;
	netdev->hw_features |= NETIF_F_RXALL;

	netdev->netdev_ops = &e100_netdev_ops;
	netdev->ethtool_ops = &e100_ethtool_ops;
	netdev->watchdog_timeo = E100_WATCHDOG_PERIOD;
	strscpy(netdev->name, pci_name(pdev), sizeof(netdev->name));

	nic = netdev_priv(netdev);
	netif_napi_add_weight(netdev, &nic->napi, e100_poll, E100_NAPI_WEIGHT);
	nic->netdev = netdev;
	nic->pdev = pdev;
	nic->msg_enable = (1 << debug) - 1;
	nic->mdio_ctrl = mdio_ctrl_hw;
	pci_set_drvdata(pdev, netdev);

	if ((err = pci_enable_device(pdev))) {
		netif_err(nic, probe, nic->netdev, "Cannot enable PCI device, aborting\n");
		goto err_out_free_dev;
	}

	if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM)) {
		netif_err(nic, probe, nic->netdev, "Cannot find proper PCI device base address, aborting\n");
		err = -ENODEV;
		goto err_out_disable_pdev;
	}

	if ((err = pci_request_regions(pdev, DRV_NAME))) {
		netif_err(nic, probe, nic->netdev, "Cannot obtain PCI resources, aborting\n");
		goto err_out_disable_pdev;
	}

	if ((err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32)))) {
		netif_err(nic, probe, nic->netdev, "No usable DMA configuration, aborting\n");
		goto err_out_free_res;
	}

	SET_NETDEV_DEV(netdev, &pdev->dev);

	if (use_io)
		netif_info(nic, probe, nic->netdev, "using i/o access mode\n");

	nic->csr = pci_iomap(pdev, (use_io ? 1 : 0), sizeof(struct csr));
	if (!nic->csr) {
		netif_err(nic, probe, nic->netdev, "Cannot map device registers, aborting\n");
		err = -ENOMEM;
		goto err_out_free_res;
	}

	if (ent->driver_data)
		nic->flags |= ich;
	else
		nic->flags &= ~ich;

	e100_get_defaults(nic);

	/* D100 MAC doesn't allow rx of vlan packets with normal MTU */
	if (nic->mac < mac_82558_D101_A4)
		netdev->features |= NETIF_F_VLAN_CHALLENGED;

	/* locks must be initialized before calling hw_reset */
	spin_lock_init(&nic->cb_lock);
	spin_lock_init(&nic->cmd_lock);
	spin_lock_init(&nic->mdio_lock);

	/* Reset the device before pci_set_master() in case device is in some
	 * funky state and has an interrupt pending - hint: we don't have the
	 * interrupt handler registered yet. */
	e100_hw_reset(nic);

	pci_set_master(pdev);

	timer_setup(&nic->watchdog, e100_watchdog, 0);

	INIT_WORK(&nic->tx_timeout_task, e100_tx_timeout_task);

	if ((err = e100_alloc(nic))) {
		netif_err(nic, probe, nic->netdev, "Cannot alloc driver memory, aborting\n");
		goto err_out_iounmap;
	}

	if ((err = e100_eeprom_load(nic)))
		goto err_out_free;

	e100_phy_init(nic);

	eth_hw_addr_set(netdev, (u8 *)nic->eeprom);
	if (!is_valid_ether_addr(netdev->dev_addr)) {
		if (!eeprom_bad_csum_allow) {
			netif_err(nic, probe, nic->netdev, "Invalid MAC address from EEPROM, aborting\n");
			err = -EAGAIN;
			goto err_out_free;
		} else {
			netif_err(nic, probe, nic->netdev, "Invalid MAC address from EEPROM, you MUST configure one.\n");
		}
	}

	/* Wol magic packet can be enabled from eeprom */
	if ((nic->mac >= mac_82558_D101_A4) &&
	   (le16_to_cpu(nic->eeprom[eeprom_id]) & eeprom_id_wol)) {
		nic->flags |= wol_magic;
		device_set_wakeup_enable(&pdev->dev, true);
	}

	/* ack any pending wake events, disable PME */
	pci_pme_active(pdev, false);

	strcpy(netdev->name, "eth%d");
	if ((err = register_netdev(netdev))) {
		netif_err(nic, probe, nic->netdev, "Cannot register net device, aborting\n");
		goto err_out_free;
	}
	nic->cbs_pool = dma_pool_create(netdev->name,
			   &nic->pdev->dev,
			   nic->params.cbs.max * sizeof(struct cb),
			   sizeof(u32),
			   0);
	if (!nic->cbs_pool) {
		netif_err(nic, probe, nic->netdev, "Cannot create DMA pool, aborting\n");
		err = -ENOMEM;
		goto err_out_pool;
	}
	netif_info(nic, probe, nic->netdev,
		   "addr 0x%llx, irq %d, MAC addr %pM\n",
		   (unsigned long long)pci_resource_start(pdev, use_io ? 1 : 0),
		   pdev->irq, netdev->dev_addr);

	return 0;

err_out_pool:
	unregister_netdev(netdev);
err_out_free:
	e100_free(nic);
err_out_iounmap:
	pci_iounmap(pdev, nic->csr);
err_out_free_res:
	pci_release_regions(pdev);
err_out_disable_pdev:
	pci_disable_device(pdev);
err_out_free_dev:
	free_netdev(netdev);
	return err;
}

static void e100_remove(struct pci_dev *pdev)
{
	struct net_device *netdev = pci_get_drvdata(pdev);

	if (netdev) {
		struct nic *nic = netdev_priv(netdev);
		unregister_netdev(netdev);
		e100_free(nic);
		pci_iounmap(pdev, nic->csr);
		dma_pool_destroy(nic->cbs_pool);
		free_netdev(netdev);
		pci_release_regions(pdev);
		pci_disable_device(pdev);
	}
}

#define E100_82552_SMARTSPEED   0x14   /* SmartSpeed Ctrl register */
#define E100_82552_REV_ANEG     0x0200 /* Reverse auto-negotiation */
#define E100_82552_ANEG_NOW     0x0400 /* Auto-negotiate now */
static void __e100_shutdown(struct pci_dev *pdev, bool *enable_wake)
{
	struct net_device *netdev = pci_get_drvdata(pdev);
	struct nic *nic = netdev_priv(netdev);

	netif_device_detach(netdev);

	if (netif_running(netdev))
		e100_down(nic);

	if ((nic->flags & wol_magic) | e100_asf(nic)) {
		/* enable reverse auto-negotiation */
		if (nic->phy == phy_82552_v) {
			u16 smartspeed = mdio_read(netdev, nic->mii.phy_id,
			                           E100_82552_SMARTSPEED);

			mdio_write(netdev, nic->mii.phy_id,
			           E100_82552_SMARTSPEED, smartspeed |
			           E100_82552_REV_ANEG | E100_82552_ANEG_NOW);
		}
		*enable_wake = true;
	} else {
		*enable_wake = false;
	}

	pci_disable_device(pdev);
}

static int __e100_power_off(struct pci_dev *pdev, bool wake)
{
	if (wake)
		return pci_prepare_to_sleep(pdev);

	pci_wake_from_d3(pdev, false);
	pci_set_power_state(pdev, PCI_D3hot);

	return 0;
}

static int __maybe_unused e100_suspend(struct device *dev_d)
{
	bool wake;

	__e100_shutdown(to_pci_dev(dev_d), &wake);

	return 0;
}

static int __maybe_unused e100_resume(struct device *dev_d)
{
	struct net_device *netdev = dev_get_drvdata(dev_d);
	struct nic *nic = netdev_priv(netdev);
	int err;

	err = pci_enable_device(to_pci_dev(dev_d));
	if (err) {
		netdev_err(netdev, "Resume cannot enable PCI device, aborting\n");
		return err;
	}
	pci_set_master(to_pci_dev(dev_d));

	/* disable reverse auto-negotiation */
	if (nic->phy == phy_82552_v) {
		u16 smartspeed = mdio_read(netdev, nic->mii.phy_id,
		                           E100_82552_SMARTSPEED);

		mdio_write(netdev, nic->mii.phy_id,
		           E100_82552_SMARTSPEED,
		           smartspeed & ~(E100_82552_REV_ANEG));
	}

	if (netif_running(netdev))
		e100_up(nic);

	netif_device_attach(netdev);

	return 0;
}

static void e100_shutdown(struct pci_dev *pdev)
{
	bool wake;
	__e100_shutdown(pdev, &wake);
	if (system_state == SYSTEM_POWER_OFF)
		__e100_power_off(pdev, wake);
}

/* ------------------ PCI Error Recovery infrastructure  -------------- */
/**
 * e100_io_error_detected - called when PCI error is detected.
 * @pdev: Pointer to PCI device
 * @state: The current pci connection state
 */
static pci_ers_result_t e100_io_error_detected(struct pci_dev *pdev, pci_channel_state_t state)
{
	struct net_device *netdev = pci_get_drvdata(pdev);
	struct nic *nic = netdev_priv(netdev);

	netif_device_detach(netdev);

	if (state == pci_channel_io_perm_failure)
		return PCI_ERS_RESULT_DISCONNECT;

	if (netif_running(netdev))
		e100_down(nic);
	pci_disable_device(pdev);

	/* Request a slot reset. */
	return PCI_ERS_RESULT_NEED_RESET;
}

/**
 * e100_io_slot_reset - called after the pci bus has been reset.
 * @pdev: Pointer to PCI device
 *
 * Restart the card from scratch.
 */
static pci_ers_result_t e100_io_slot_reset(struct pci_dev *pdev)
{
	struct net_device *netdev = pci_get_drvdata(pdev);
	struct nic *nic = netdev_priv(netdev);

	if (pci_enable_device(pdev)) {
		pr_err("Cannot re-enable PCI device after reset\n");
		return PCI_ERS_RESULT_DISCONNECT;
	}
	pci_set_master(pdev);

	/* Only one device per card can do a reset */
	if (0 != PCI_FUNC(pdev->devfn))
		return PCI_ERS_RESULT_RECOVERED;
	e100_hw_reset(nic);
	e100_phy_init(nic);

	return PCI_ERS_RESULT_RECOVERED;
}

/**
 * e100_io_resume - resume normal operations
 * @pdev: Pointer to PCI device
 *
 * Resume normal operations after an error recovery
 * sequence has been completed.
 */
static void e100_io_resume(struct pci_dev *pdev)
{
	struct net_device *netdev = pci_get_drvdata(pdev);
	struct nic *nic = netdev_priv(netdev);

	/* ack any pending wake events, disable PME */
	pci_enable_wake(pdev, PCI_D0, 0);

	netif_device_attach(netdev);
	if (netif_running(netdev)) {
		e100_open(netdev);
		mod_timer(&nic->watchdog, jiffies);
	}
}

static const struct pci_error_handlers e100_err_handler = {
	.error_detected = e100_io_error_detected,
	.slot_reset = e100_io_slot_reset,
	.resume = e100_io_resume,
};

static SIMPLE_DEV_PM_OPS(e100_pm_ops, e100_suspend, e100_resume);

static struct pci_driver e100_driver = {
	.name =         DRV_NAME,
	.id_table =     e100_id_table,
	.probe =        e100_probe,
	.remove =       e100_remove,

	/* Power Management hooks */
	.driver.pm =	&e100_pm_ops,

	.shutdown =     e100_shutdown,
	.err_handler = &e100_err_handler,
};

static int __init e100_init_module(void)
{
	if (((1 << debug) - 1) & NETIF_MSG_DRV) {
		pr_info("%s\n", DRV_DESCRIPTION);
		pr_info("%s\n", DRV_COPYRIGHT);
	}
	return pci_register_driver(&e100_driver);
}

static void __exit e100_cleanup_module(void)
{
	pci_unregister_driver(&e100_driver);
}

module_init(e100_init_module);
module_exit(e100_cleanup_module);