xref: /illumos-gate/usr/src/cmd/bhyve/pci_xhci.c (revision 4c87aefe8930bd07275b8dd2e96ea5f24d93a52e)

/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2014 Leon Dang <ldang@nahannisys.com>
 * Copyright 2018 Joyent, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
/*
   XHCI options:
    -s <n>,xhci,{devices}

   devices:
     tablet             USB tablet mouse
 */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/uio.h>
#include <sys/types.h>
#include <sys/queue.h>

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <pthread.h>
#include <unistd.h>

#include <dev/usb/usbdi.h>
#include <dev/usb/usb.h>
#include <dev/usb/usb_freebsd.h>
#include <xhcireg.h>

#include "bhyverun.h"
#include "pci_emul.h"
#include "pci_xhci.h"
#include "usb_emul.h"


static int xhci_debug = 0;
#define	DPRINTF(params) if (xhci_debug) printf params
#define	WPRINTF(params) printf params


#define	XHCI_NAME		"xhci"
#define	XHCI_MAX_DEVS		8	/* 4 USB3 + 4 USB2 devs */

#define	XHCI_MAX_SLOTS		64	/* min allowed by Windows drivers */

/*
 * XHCI data structures can be up to 64k, but limit paddr_guest2host mapping
 * to 4k to avoid going over the guest physical memory barrier.
 */
#define	XHCI_PADDR_SZ		4096	/* paddr_guest2host max size */

#define	XHCI_ERST_MAX		0	/* max 2^entries event ring seg tbl */

#define	XHCI_CAPLEN		(4*8)	/* offset of op register space */
#define	XHCI_HCCPRAMS2		0x1C	/* offset of HCCPARAMS2 register */
#define	XHCI_PORTREGS_START	0x400
#define	XHCI_DOORBELL_MAX	256

#define	XHCI_STREAMS_MAX	1	/* 4-15 in XHCI spec */

/* caplength and hci-version registers */
#define	XHCI_SET_CAPLEN(x)		((x) & 0xFF)
#define	XHCI_SET_HCIVERSION(x)		(((x) & 0xFFFF) << 16)
#define	XHCI_GET_HCIVERSION(x)		(((x) >> 16) & 0xFFFF)

/* hcsparams1 register */
#define	XHCI_SET_HCSP1_MAXSLOTS(x)	((x) & 0xFF)
#define	XHCI_SET_HCSP1_MAXINTR(x)	(((x) & 0x7FF) << 8)
#define	XHCI_SET_HCSP1_MAXPORTS(x)	(((x) & 0xFF) << 24)

/* hcsparams2 register */
#define	XHCI_SET_HCSP2_IST(x)		((x) & 0x0F)
#define	XHCI_SET_HCSP2_ERSTMAX(x)	(((x) & 0x0F) << 4)
#define	XHCI_SET_HCSP2_MAXSCRATCH_HI(x)	(((x) & 0x1F) << 21)
#define	XHCI_SET_HCSP2_MAXSCRATCH_LO(x)	(((x) & 0x1F) << 27)

/* hcsparams3 register */
#define	XHCI_SET_HCSP3_U1EXITLATENCY(x)	((x) & 0xFF)
#define	XHCI_SET_HCSP3_U2EXITLATENCY(x)	(((x) & 0xFFFF) << 16)

/* hccparams1 register */
#define	XHCI_SET_HCCP1_AC64(x)		((x) & 0x01)
#define	XHCI_SET_HCCP1_BNC(x)		(((x) & 0x01) << 1)
#define	XHCI_SET_HCCP1_CSZ(x)		(((x) & 0x01) << 2)
#define	XHCI_SET_HCCP1_PPC(x)		(((x) & 0x01) << 3)
#define	XHCI_SET_HCCP1_PIND(x)		(((x) & 0x01) << 4)
#define	XHCI_SET_HCCP1_LHRC(x)		(((x) & 0x01) << 5)
#define	XHCI_SET_HCCP1_LTC(x)		(((x) & 0x01) << 6)
#define	XHCI_SET_HCCP1_NSS(x)		(((x) & 0x01) << 7)
#define	XHCI_SET_HCCP1_PAE(x)		(((x) & 0x01) << 8)
#define	XHCI_SET_HCCP1_SPC(x)		(((x) & 0x01) << 9)
#define	XHCI_SET_HCCP1_SEC(x)		(((x) & 0x01) << 10)
#define	XHCI_SET_HCCP1_CFC(x)		(((x) & 0x01) << 11)
#define	XHCI_SET_HCCP1_MAXPSA(x)	(((x) & 0x0F) << 12)
#define	XHCI_SET_HCCP1_XECP(x)		(((x) & 0xFFFF) << 16)

/* hccparams2 register */
#define	XHCI_SET_HCCP2_U3C(x)		((x) & 0x01)
#define	XHCI_SET_HCCP2_CMC(x)		(((x) & 0x01) << 1)
#define	XHCI_SET_HCCP2_FSC(x)		(((x) & 0x01) << 2)
#define	XHCI_SET_HCCP2_CTC(x)		(((x) & 0x01) << 3)
#define	XHCI_SET_HCCP2_LEC(x)		(((x) & 0x01) << 4)
#define	XHCI_SET_HCCP2_CIC(x)		(((x) & 0x01) << 5)

/* other registers */
#define	XHCI_SET_DOORBELL(x)		((x) & ~0x03)
#define	XHCI_SET_RTSOFFSET(x)		((x) & ~0x0F)

/* register masks */
#define	XHCI_PS_PLS_MASK		(0xF << 5)	/* port link state */
#define	XHCI_PS_SPEED_MASK		(0xF << 10)	/* port speed */
#define	XHCI_PS_PIC_MASK		(0x3 << 14)	/* port indicator */

/* port register set */
#define	XHCI_PORTREGS_BASE		0x400		/* base offset */
#define	XHCI_PORTREGS_PORT0		0x3F0
#define	XHCI_PORTREGS_SETSZ		0x10		/* size of a set */

#define	MASK_64_HI(x)			((x) & ~0xFFFFFFFFULL)
#define	MASK_64_LO(x)			((x) & 0xFFFFFFFFULL)

#define	FIELD_REPLACE(a,b,m,s)		(((a) & ~((m) << (s))) | \
					(((b) & (m)) << (s)))
#define	FIELD_COPY(a,b,m,s)		(((a) & ~((m) << (s))) | \
					(((b) & ((m) << (s)))))

struct pci_xhci_trb_ring {
	uint64_t ringaddr;		/* current dequeue guest address */
	uint32_t ccs;			/* consumer cycle state */
};

/* device endpoint transfer/stream rings */
struct pci_xhci_dev_ep {
	union {
		struct xhci_trb		*_epu_tr;
		struct xhci_stream_ctx	*_epu_sctx;
	} _ep_trbsctx;
#define	ep_tr		_ep_trbsctx._epu_tr
#define	ep_sctx		_ep_trbsctx._epu_sctx

	union {
		struct pci_xhci_trb_ring _epu_trb;
		struct pci_xhci_trb_ring *_epu_sctx_trbs;
	} _ep_trb_rings;
#define	ep_ringaddr	_ep_trb_rings._epu_trb.ringaddr
#define	ep_ccs		_ep_trb_rings._epu_trb.ccs
#define	ep_sctx_trbs	_ep_trb_rings._epu_sctx_trbs

	struct usb_data_xfer *ep_xfer;	/* transfer chain */
};

/* device context base address array: maps slot->device context */
struct xhci_dcbaa {
	uint64_t dcba[USB_MAX_DEVICES+1]; /* xhci_dev_ctx ptrs */
};

/* port status registers */
struct pci_xhci_portregs {
	uint32_t	portsc;		/* port status and control */
	uint32_t	portpmsc;	/* port pwr mgmt status & control */
	uint32_t	portli;		/* port link info */
	uint32_t	porthlpmc;	/* port hardware LPM control */
} __packed;
#define	XHCI_PS_SPEED_SET(x)	(((x) & 0xF) << 10)

/* xHC operational registers */
struct pci_xhci_opregs {
	uint32_t	usbcmd;		/* usb command */
	uint32_t	usbsts;		/* usb status */
	uint32_t	pgsz;		/* page size */
	uint32_t	dnctrl;		/* device notification control */
	uint64_t	crcr;		/* command ring control */
	uint64_t	dcbaap;		/* device ctx base addr array ptr */
	uint32_t	config;		/* configure */

	/* guest mapped addresses: */
	struct xhci_trb	*cr_p;		/* crcr dequeue */
	struct xhci_dcbaa *dcbaa_p;	/* dev ctx array ptr */
};

/* xHC runtime registers */
struct pci_xhci_rtsregs {
	uint32_t	mfindex;	/* microframe index */
	struct {			/* interrupter register set */
		uint32_t	iman;	/* interrupter management */
		uint32_t	imod;	/* interrupter moderation */
		uint32_t	erstsz;	/* event ring segment table size */
		uint32_t	rsvd;
		uint64_t	erstba;	/* event ring seg-tbl base addr */
		uint64_t	erdp;	/* event ring dequeue ptr */
	} intrreg __packed;

	/* guest mapped addresses */
	struct xhci_event_ring_seg *erstba_p;
	struct xhci_trb *erst_p;	/* event ring segment tbl */
	int		er_deq_seg;	/* event ring dequeue segment */
	int		er_enq_idx;	/* event ring enqueue index - xHCI */
	int		er_enq_seg;	/* event ring enqueue segment */
	uint32_t	er_events_cnt;	/* number of events in ER */
	uint32_t	event_pcs;	/* producer cycle state flag */
};


struct pci_xhci_softc;


/*
 * USB device emulation container.
 * This is referenced from usb_hci->hci_sc; 1 pci_xhci_dev_emu for each
 * emulated device instance.
 */
struct pci_xhci_dev_emu {
	struct pci_xhci_softc	*xsc;

	/* XHCI contexts */
	struct xhci_dev_ctx	*dev_ctx;
	struct pci_xhci_dev_ep	eps[XHCI_MAX_ENDPOINTS];
	int			dev_slotstate;

	struct usb_devemu	*dev_ue;	/* USB emulated dev */
	void			*dev_sc;	/* device's softc */

	struct usb_hci		hci;
};

struct pci_xhci_softc {
	struct pci_devinst *xsc_pi;

	pthread_mutex_t	mtx;

	uint32_t	caplength;	/* caplen & hciversion */
	uint32_t	hcsparams1;	/* structural parameters 1 */
	uint32_t	hcsparams2;	/* structural parameters 2 */
	uint32_t	hcsparams3;	/* structural parameters 3 */
	uint32_t	hccparams1;	/* capability parameters 1 */
	uint32_t	dboff;		/* doorbell offset */
	uint32_t	rtsoff;		/* runtime register space offset */
	uint32_t	hccparams2;	/* capability parameters 2 */

	uint32_t	regsend;	/* end of configuration registers */

	struct pci_xhci_opregs  opregs;
	struct pci_xhci_rtsregs rtsregs;

	struct pci_xhci_portregs *portregs;
	struct pci_xhci_dev_emu  **devices; /* XHCI[port] = device */
	struct pci_xhci_dev_emu  **slots;   /* slots assigned from 1 */
	int		ndevices;

	int		usb2_port_start;
	int		usb3_port_start;
};


/* portregs and devices arrays are set up to start from idx=1 */
#define	XHCI_PORTREG_PTR(x,n)	&(x)->portregs[(n)]
#define	XHCI_DEVINST_PTR(x,n)	(x)->devices[(n)]
#define	XHCI_SLOTDEV_PTR(x,n)	(x)->slots[(n)]

#define	XHCI_HALTED(sc)		((sc)->opregs.usbsts & XHCI_STS_HCH)

#define	XHCI_GADDR(sc,a)	paddr_guest2host((sc)->xsc_pi->pi_vmctx, \
				    (a),                                 \
				    XHCI_PADDR_SZ - ((a) & (XHCI_PADDR_SZ-1)))

static int xhci_in_use;

/* map USB errors to XHCI */
static const int xhci_usb_errors[USB_ERR_MAX] = {
	[USB_ERR_NORMAL_COMPLETION]	= XHCI_TRB_ERROR_SUCCESS,
	[USB_ERR_PENDING_REQUESTS]	= XHCI_TRB_ERROR_RESOURCE,
	[USB_ERR_NOT_STARTED]		= XHCI_TRB_ERROR_ENDP_NOT_ON,
	[USB_ERR_INVAL]			= XHCI_TRB_ERROR_INVALID,
	[USB_ERR_NOMEM]			= XHCI_TRB_ERROR_RESOURCE,
	[USB_ERR_CANCELLED]		= XHCI_TRB_ERROR_STOPPED,
	[USB_ERR_BAD_ADDRESS]		= XHCI_TRB_ERROR_PARAMETER,
	[USB_ERR_BAD_BUFSIZE]		= XHCI_TRB_ERROR_PARAMETER,
	[USB_ERR_BAD_FLAG]		= XHCI_TRB_ERROR_PARAMETER,
	[USB_ERR_NO_CALLBACK]		= XHCI_TRB_ERROR_STALL,
	[USB_ERR_IN_USE]		= XHCI_TRB_ERROR_RESOURCE,
	[USB_ERR_NO_ADDR]		= XHCI_TRB_ERROR_RESOURCE,
	[USB_ERR_NO_PIPE]               = XHCI_TRB_ERROR_RESOURCE,
	[USB_ERR_ZERO_NFRAMES]          = XHCI_TRB_ERROR_UNDEFINED,
	[USB_ERR_ZERO_MAXP]             = XHCI_TRB_ERROR_UNDEFINED,
	[USB_ERR_SET_ADDR_FAILED]       = XHCI_TRB_ERROR_RESOURCE,
	[USB_ERR_NO_POWER]              = XHCI_TRB_ERROR_ENDP_NOT_ON,
	[USB_ERR_TOO_DEEP]              = XHCI_TRB_ERROR_RESOURCE,
	[USB_ERR_IOERROR]               = XHCI_TRB_ERROR_TRB,
	[USB_ERR_NOT_CONFIGURED]        = XHCI_TRB_ERROR_ENDP_NOT_ON,
	[USB_ERR_TIMEOUT]               = XHCI_TRB_ERROR_CMD_ABORTED,
	[USB_ERR_SHORT_XFER]            = XHCI_TRB_ERROR_SHORT_PKT,
	[USB_ERR_STALLED]               = XHCI_TRB_ERROR_STALL,
	[USB_ERR_INTERRUPTED]           = XHCI_TRB_ERROR_CMD_ABORTED,
	[USB_ERR_DMA_LOAD_FAILED]       = XHCI_TRB_ERROR_DATA_BUF,
	[USB_ERR_BAD_CONTEXT]           = XHCI_TRB_ERROR_TRB,
	[USB_ERR_NO_ROOT_HUB]           = XHCI_TRB_ERROR_UNDEFINED,
	[USB_ERR_NO_INTR_THREAD]        = XHCI_TRB_ERROR_UNDEFINED,
	[USB_ERR_NOT_LOCKED]            = XHCI_TRB_ERROR_UNDEFINED,
};
#define	USB_TO_XHCI_ERR(e)	((e) < USB_ERR_MAX ? xhci_usb_errors[(e)] : \
				XHCI_TRB_ERROR_INVALID)

static int pci_xhci_insert_event(struct pci_xhci_softc *sc,
    struct xhci_trb *evtrb, int do_intr);
static void pci_xhci_dump_trb(struct xhci_trb *trb);
static void pci_xhci_assert_interrupt(struct pci_xhci_softc *sc);
static void pci_xhci_reset_slot(struct pci_xhci_softc *sc, int slot);
static void pci_xhci_reset_port(struct pci_xhci_softc *sc, int portn, int warm);
static void pci_xhci_update_ep_ring(struct pci_xhci_softc *sc,
    struct pci_xhci_dev_emu *dev, struct pci_xhci_dev_ep *devep,
    struct xhci_endp_ctx *ep_ctx, uint32_t streamid,
    uint64_t ringaddr, int ccs);

static void
pci_xhci_set_evtrb(struct xhci_trb *evtrb, uint64_t port, uint32_t errcode,
    uint32_t evtype)
{
	evtrb->qwTrb0 = port << 24;
	evtrb->dwTrb2 = XHCI_TRB_2_ERROR_SET(errcode);
	evtrb->dwTrb3 = XHCI_TRB_3_TYPE_SET(evtype);
}


/* controller reset */
static void
pci_xhci_reset(struct pci_xhci_softc *sc)
{
	int i;

	sc->rtsregs.er_enq_idx = 0;
	sc->rtsregs.er_events_cnt = 0;
	sc->rtsregs.event_pcs = 1;

	for (i = 1; i <= XHCI_MAX_SLOTS; i++) {
		pci_xhci_reset_slot(sc, i);
	}
}

static uint32_t
pci_xhci_usbcmd_write(struct pci_xhci_softc *sc, uint32_t cmd)
{
	int do_intr = 0;
	int i;

	if (cmd & XHCI_CMD_RS) {
		do_intr = (sc->opregs.usbcmd & XHCI_CMD_RS) == 0;

		sc->opregs.usbcmd |= XHCI_CMD_RS;
		sc->opregs.usbsts &= ~XHCI_STS_HCH;
		sc->opregs.usbsts |= XHCI_STS_PCD;

		/* Queue port change event on controller run from stop */
		if (do_intr)
			for (i = 1; i <= XHCI_MAX_DEVS; i++) {
				struct pci_xhci_dev_emu *dev;
				struct pci_xhci_portregs *port;
				struct xhci_trb		evtrb;

				if ((dev = XHCI_DEVINST_PTR(sc, i)) == NULL)
					continue;

				port = XHCI_PORTREG_PTR(sc, i);
				port->portsc |= XHCI_PS_CSC | XHCI_PS_CCS;
				port->portsc &= ~XHCI_PS_PLS_MASK;

				/*
				 * XHCI 4.19.3 USB2 RxDetect->Polling,
				 *             USB3 Polling->U0
				 */
				if (dev->dev_ue->ue_usbver == 2)
					port->portsc |=
					    XHCI_PS_PLS_SET(UPS_PORT_LS_POLL);
				else
					port->portsc |=
					    XHCI_PS_PLS_SET(UPS_PORT_LS_U0);

				pci_xhci_set_evtrb(&evtrb, i,
				    XHCI_TRB_ERROR_SUCCESS,
				    XHCI_TRB_EVENT_PORT_STS_CHANGE);

				if (pci_xhci_insert_event(sc, &evtrb, 0) !=
				    XHCI_TRB_ERROR_SUCCESS)
					break;
			}
	} else {
		sc->opregs.usbcmd &= ~XHCI_CMD_RS;
		sc->opregs.usbsts |= XHCI_STS_HCH;
		sc->opregs.usbsts &= ~XHCI_STS_PCD;
	}

	/* start execution of schedule; stop when set to 0 */
	cmd |= sc->opregs.usbcmd & XHCI_CMD_RS;

	if (cmd & XHCI_CMD_HCRST) {
		/* reset controller */
		pci_xhci_reset(sc);
		cmd &= ~XHCI_CMD_HCRST;
	}

	cmd &= ~(XHCI_CMD_CSS | XHCI_CMD_CRS);

	if (do_intr)
		pci_xhci_assert_interrupt(sc);

	return (cmd);
}

static void
pci_xhci_portregs_write(struct pci_xhci_softc *sc, uint64_t offset,
    uint64_t value)
{
	struct xhci_trb		evtrb;
	struct pci_xhci_portregs *p;
	int port;
	uint32_t oldpls, newpls;

	if (sc->portregs == NULL)
		return;

	port = (offset - XHCI_PORTREGS_PORT0) / XHCI_PORTREGS_SETSZ;
	offset = (offset - XHCI_PORTREGS_PORT0) % XHCI_PORTREGS_SETSZ;

	DPRINTF(("pci_xhci: portregs wr offset 0x%lx, port %u: 0x%lx\r\n",
	        offset, port, value));

	assert(port >= 0);

	if (port > XHCI_MAX_DEVS) {
		DPRINTF(("pci_xhci: portregs_write port %d > ndevices\r\n",
		    port));
		return;
	}

	if (XHCI_DEVINST_PTR(sc, port) == NULL) {
		DPRINTF(("pci_xhci: portregs_write to unattached port %d\r\n",
		     port));
	}

	p = XHCI_PORTREG_PTR(sc, port);
	switch (offset) {
	case 0:
		/* port reset or warm reset */
		if (value & (XHCI_PS_PR | XHCI_PS_WPR)) {
			pci_xhci_reset_port(sc, port, value & XHCI_PS_WPR);
			break;
		}

		if ((p->portsc & XHCI_PS_PP) == 0) {
			WPRINTF(("pci_xhci: portregs_write to unpowered "
			         "port %d\r\n", port));
			break;
		}

		/* Port status and control register  */
		oldpls = XHCI_PS_PLS_GET(p->portsc);
		newpls = XHCI_PS_PLS_GET(value);

		p->portsc &= XHCI_PS_PED | XHCI_PS_PLS_MASK |
		             XHCI_PS_SPEED_MASK | XHCI_PS_PIC_MASK;

		if (XHCI_DEVINST_PTR(sc, port))
			p->portsc |= XHCI_PS_CCS;

		p->portsc |= (value &
		              ~(XHCI_PS_OCA |
		                XHCI_PS_PR  |
			        XHCI_PS_PED |
			        XHCI_PS_PLS_MASK   |	/* link state */
			        XHCI_PS_SPEED_MASK |
			        XHCI_PS_PIC_MASK   |	/* port indicator */
			        XHCI_PS_LWS | XHCI_PS_DR | XHCI_PS_WPR));

		/* clear control bits */
		p->portsc &= ~(value &
		               (XHCI_PS_CSC |
		                XHCI_PS_PEC |
		                XHCI_PS_WRC |
		                XHCI_PS_OCC |
		                XHCI_PS_PRC |
		                XHCI_PS_PLC |
		                XHCI_PS_CEC |
		                XHCI_PS_CAS));

		/* port disable request; for USB3, don't care */
		if (value & XHCI_PS_PED)
			DPRINTF(("Disable port %d request\r\n", port));

		if (!(value & XHCI_PS_LWS))
			break;

		DPRINTF(("Port new PLS: %d\r\n", newpls));
		switch (newpls) {
		case 0: /* U0 */
		case 3: /* U3 */
			if (oldpls != newpls) {
				p->portsc &= ~XHCI_PS_PLS_MASK;
				p->portsc |= XHCI_PS_PLS_SET(newpls) |
				             XHCI_PS_PLC;

				if (oldpls != 0 && newpls == 0) {
					pci_xhci_set_evtrb(&evtrb, port,
					    XHCI_TRB_ERROR_SUCCESS,
					    XHCI_TRB_EVENT_PORT_STS_CHANGE);

					pci_xhci_insert_event(sc, &evtrb, 1);
				}
			}
			break;

		default:
			DPRINTF(("Unhandled change port %d PLS %u\r\n",
			         port, newpls));
			break;
		}
		break;
	case 4:
		/* Port power management status and control register  */
		p->portpmsc = value;
		break;
	case 8:
		/* Port link information register */
		DPRINTF(("pci_xhci attempted write to PORTLI, port %d\r\n",
		        port));
		break;
	case 12:
		/*
		 * Port hardware LPM control register.
		 * For USB3, this register is reserved.
		 */
		p->porthlpmc = value;
		break;
	}
}

struct xhci_dev_ctx *
pci_xhci_get_dev_ctx(struct pci_xhci_softc *sc, uint32_t slot)
{
	uint64_t devctx_addr;
	struct xhci_dev_ctx *devctx;

	assert(slot > 0 && slot <= sc->ndevices);
	assert(sc->opregs.dcbaa_p != NULL);

	devctx_addr = sc->opregs.dcbaa_p->dcba[slot];

	if (devctx_addr == 0) {
		DPRINTF(("get_dev_ctx devctx_addr == 0\r\n"));
		return (NULL);
	}

	DPRINTF(("pci_xhci: get dev ctx, slot %u devctx addr %016lx\r\n",
	        slot, devctx_addr));
	devctx = XHCI_GADDR(sc, devctx_addr & ~0x3FUL);

	return (devctx);
}

struct xhci_trb *
pci_xhci_trb_next(struct pci_xhci_softc *sc, struct xhci_trb *curtrb,
    uint64_t *guestaddr)
{
	struct xhci_trb *next;

	assert(curtrb != NULL);

	if (XHCI_TRB_3_TYPE_GET(curtrb->dwTrb3) == XHCI_TRB_TYPE_LINK) {
		if (guestaddr)
			*guestaddr = curtrb->qwTrb0 & ~0xFUL;

		next = XHCI_GADDR(sc, curtrb->qwTrb0 & ~0xFUL);
	} else {
		if (guestaddr)
			*guestaddr += sizeof(struct xhci_trb) & ~0xFUL;

		next = curtrb + 1;
	}

	return (next);
}

static void
pci_xhci_assert_interrupt(struct pci_xhci_softc *sc)
{

	sc->rtsregs.intrreg.erdp |= XHCI_ERDP_LO_BUSY;
	sc->rtsregs.intrreg.iman |= XHCI_IMAN_INTR_PEND;
	sc->opregs.usbsts |= XHCI_STS_EINT;

	/* only trigger interrupt if permitted */
	if ((sc->opregs.usbcmd & XHCI_CMD_INTE) &&
	    (sc->rtsregs.intrreg.iman & XHCI_IMAN_INTR_ENA)) {
		if (pci_msi_enabled(sc->xsc_pi))
			pci_generate_msi(sc->xsc_pi, 0);
		else
			pci_lintr_assert(sc->xsc_pi);
	}
}

static void
pci_xhci_deassert_interrupt(struct pci_xhci_softc *sc)
{

	if (!pci_msi_enabled(sc->xsc_pi))
		pci_lintr_assert(sc->xsc_pi);
}

static void
pci_xhci_init_ep(struct pci_xhci_dev_emu *dev, int epid)
{
	struct xhci_dev_ctx    *dev_ctx;
	struct pci_xhci_dev_ep *devep;
	struct xhci_endp_ctx   *ep_ctx;
	uint32_t	pstreams;
	int		i;

	dev_ctx = dev->dev_ctx;
	ep_ctx = &dev_ctx->ctx_ep[epid];
	devep = &dev->eps[epid];
	pstreams = XHCI_EPCTX_0_MAXP_STREAMS_GET(ep_ctx->dwEpCtx0);
	if (pstreams > 0) {
		DPRINTF(("init_ep %d with pstreams %d\r\n", epid, pstreams));
		assert(devep->ep_sctx_trbs == NULL);

		devep->ep_sctx = XHCI_GADDR(dev->xsc, ep_ctx->qwEpCtx2 &
		                            XHCI_EPCTX_2_TR_DQ_PTR_MASK);
		devep->ep_sctx_trbs = calloc(pstreams,
		                      sizeof(struct pci_xhci_trb_ring));
		for (i = 0; i < pstreams; i++) {
			devep->ep_sctx_trbs[i].ringaddr =
			                         devep->ep_sctx[i].qwSctx0 &
			                         XHCI_SCTX_0_TR_DQ_PTR_MASK;
			devep->ep_sctx_trbs[i].ccs =
			     XHCI_SCTX_0_DCS_GET(devep->ep_sctx[i].qwSctx0);
		}
	} else {
		DPRINTF(("init_ep %d with no pstreams\r\n", epid));
		devep->ep_ringaddr = ep_ctx->qwEpCtx2 &
		                     XHCI_EPCTX_2_TR_DQ_PTR_MASK;
		devep->ep_ccs = XHCI_EPCTX_2_DCS_GET(ep_ctx->qwEpCtx2);
		devep->ep_tr = XHCI_GADDR(dev->xsc, devep->ep_ringaddr);
		DPRINTF(("init_ep tr DCS %x\r\n", devep->ep_ccs));
	}

	if (devep->ep_xfer == NULL) {
		devep->ep_xfer = malloc(sizeof(struct usb_data_xfer));
		USB_DATA_XFER_INIT(devep->ep_xfer);
	}
}

static void
pci_xhci_disable_ep(struct pci_xhci_dev_emu *dev, int epid)
{
	struct xhci_dev_ctx    *dev_ctx;
	struct pci_xhci_dev_ep *devep;
	struct xhci_endp_ctx   *ep_ctx;

	DPRINTF(("pci_xhci disable_ep %d\r\n", epid));

	dev_ctx = dev->dev_ctx;
	ep_ctx = &dev_ctx->ctx_ep[epid];
	ep_ctx->dwEpCtx0 = (ep_ctx->dwEpCtx0 & ~0x7) | XHCI_ST_EPCTX_DISABLED;

	devep = &dev->eps[epid];
	if (XHCI_EPCTX_0_MAXP_STREAMS_GET(ep_ctx->dwEpCtx0) > 0 &&
	    devep->ep_sctx_trbs != NULL)
			free(devep->ep_sctx_trbs);

	if (devep->ep_xfer != NULL) {
		free(devep->ep_xfer);
		devep->ep_xfer = NULL;
	}

	memset(devep, 0, sizeof(struct pci_xhci_dev_ep));
}


/* reset device at slot and data structures related to it */
static void
pci_xhci_reset_slot(struct pci_xhci_softc *sc, int slot)
{
	struct pci_xhci_dev_emu *dev;

	dev = XHCI_SLOTDEV_PTR(sc, slot);

	if (!dev) {
		DPRINTF(("xhci reset unassigned slot (%d)?\r\n", slot));
	} else {
		dev->dev_slotstate = XHCI_ST_DISABLED;
	}

	/* TODO: reset ring buffer pointers */
}

static int
pci_xhci_insert_event(struct pci_xhci_softc *sc, struct xhci_trb *evtrb,
    int do_intr)
{
	struct pci_xhci_rtsregs *rts;
	uint64_t	erdp;
	int		erdp_idx;
	int		err;
	struct xhci_trb *evtrbptr;

	err = XHCI_TRB_ERROR_SUCCESS;

	rts = &sc->rtsregs;

	erdp = rts->intrreg.erdp & ~0xF;
	erdp_idx = (erdp - rts->erstba_p[rts->er_deq_seg].qwEvrsTablePtr) /
	           sizeof(struct xhci_trb);

	DPRINTF(("pci_xhci: insert event 0[%lx] 2[%x] 3[%x]\r\n"
	         "\terdp idx %d/seg %d, enq idx %d/seg %d, pcs %u\r\n"
	         "\t(erdp=0x%lx, erst=0x%lx, tblsz=%u, do_intr %d)\r\n",
	         evtrb->qwTrb0, evtrb->dwTrb2, evtrb->dwTrb3,
	         erdp_idx, rts->er_deq_seg, rts->er_enq_idx,
	         rts->er_enq_seg,
	         rts->event_pcs, erdp, rts->erstba_p->qwEvrsTablePtr,
	         rts->erstba_p->dwEvrsTableSize, do_intr));

	evtrbptr = &rts->erst_p[rts->er_enq_idx];

	/* TODO: multi-segment table */
	if (rts->er_events_cnt >= rts->erstba_p->dwEvrsTableSize) {
		DPRINTF(("pci_xhci[%d] cannot insert event; ring full\r\n",
		         __LINE__));
		err = XHCI_TRB_ERROR_EV_RING_FULL;
		goto done;
	}

	if (rts->er_events_cnt == rts->erstba_p->dwEvrsTableSize - 1) {
		struct xhci_trb	errev;

		if ((evtrbptr->dwTrb3 & 0x1) == (rts->event_pcs & 0x1)) {

			DPRINTF(("pci_xhci[%d] insert evt err: ring full\r\n",
			         __LINE__));

			errev.qwTrb0 = 0;
			errev.dwTrb2 = XHCI_TRB_2_ERROR_SET(
			                    XHCI_TRB_ERROR_EV_RING_FULL);
			errev.dwTrb3 = XHCI_TRB_3_TYPE_SET(
			                    XHCI_TRB_EVENT_HOST_CTRL) |
			               rts->event_pcs;
			rts->er_events_cnt++;
			memcpy(&rts->erst_p[rts->er_enq_idx], &errev,
			       sizeof(struct xhci_trb));
			rts->er_enq_idx = (rts->er_enq_idx + 1) %
			                  rts->erstba_p->dwEvrsTableSize;
			err = XHCI_TRB_ERROR_EV_RING_FULL;
			do_intr = 1;

			goto done;
		}
	} else {
		rts->er_events_cnt++;
	}

	evtrb->dwTrb3 &= ~XHCI_TRB_3_CYCLE_BIT;
	evtrb->dwTrb3 |= rts->event_pcs;

	memcpy(&rts->erst_p[rts->er_enq_idx], evtrb, sizeof(struct xhci_trb));
	rts->er_enq_idx = (rts->er_enq_idx + 1) %
	                  rts->erstba_p->dwEvrsTableSize;

	if (rts->er_enq_idx == 0)
		rts->event_pcs ^= 1;

done:
	if (do_intr)
		pci_xhci_assert_interrupt(sc);

	return (err);
}

static uint32_t
pci_xhci_cmd_enable_slot(struct pci_xhci_softc *sc, uint32_t *slot)
{
	struct pci_xhci_dev_emu *dev;
	uint32_t	cmderr;
	int		i;

	cmderr = XHCI_TRB_ERROR_NO_SLOTS;
	if (sc->portregs != NULL)
		for (i = 1; i <= XHCI_MAX_SLOTS; i++) {
			dev = XHCI_SLOTDEV_PTR(sc, i);
			if (dev && dev->dev_slotstate == XHCI_ST_DISABLED) {
				*slot = i;
				dev->dev_slotstate = XHCI_ST_ENABLED;
				cmderr = XHCI_TRB_ERROR_SUCCESS;
				dev->hci.hci_address = i;
				break;
			}
		}

	DPRINTF(("pci_xhci enable slot (error=%d) slot %u\r\n",
		cmderr != XHCI_TRB_ERROR_SUCCESS, *slot));

	return (cmderr);
}

static uint32_t
pci_xhci_cmd_disable_slot(struct pci_xhci_softc *sc, uint32_t slot)
{
	struct pci_xhci_dev_emu *dev;
	uint32_t cmderr;

	DPRINTF(("pci_xhci disable slot %u\r\n", slot));

	cmderr = XHCI_TRB_ERROR_NO_SLOTS;
	if (sc->portregs == NULL)
		goto done;

	if (slot > sc->ndevices) {
		cmderr = XHCI_TRB_ERROR_SLOT_NOT_ON;
		goto done;
	}

	dev = XHCI_SLOTDEV_PTR(sc, slot);
	if (dev) {
		if (dev->dev_slotstate == XHCI_ST_DISABLED) {
			cmderr = XHCI_TRB_ERROR_SLOT_NOT_ON;
		} else {
			dev->dev_slotstate = XHCI_ST_DISABLED;
			cmderr = XHCI_TRB_ERROR_SUCCESS;
			/* TODO: reset events and endpoints */
		}
	}

done:
	return (cmderr);
}

static uint32_t
pci_xhci_cmd_reset_device(struct pci_xhci_softc *sc, uint32_t slot)
{
	struct pci_xhci_dev_emu *dev;
	struct xhci_dev_ctx     *dev_ctx;
	struct xhci_endp_ctx    *ep_ctx;
	uint32_t	cmderr;
	int		i;

	cmderr = XHCI_TRB_ERROR_NO_SLOTS;
	if (sc->portregs == NULL)
		goto done;

	DPRINTF(("pci_xhci reset device slot %u\r\n", slot));

	dev = XHCI_SLOTDEV_PTR(sc, slot);
	if (!dev || dev->dev_slotstate == XHCI_ST_DISABLED)
		cmderr = XHCI_TRB_ERROR_SLOT_NOT_ON;
	else {
		dev->dev_slotstate = XHCI_ST_DEFAULT;

		dev->hci.hci_address = 0;
		dev_ctx = pci_xhci_get_dev_ctx(sc, slot);

		/* slot state */
		dev_ctx->ctx_slot.dwSctx3 = FIELD_REPLACE(
		    dev_ctx->ctx_slot.dwSctx3, XHCI_ST_SLCTX_DEFAULT,
		    0x1F, 27);

		/* number of contexts */
		dev_ctx->ctx_slot.dwSctx0 = FIELD_REPLACE(
		    dev_ctx->ctx_slot.dwSctx0, 1, 0x1F, 27);

		/* reset all eps other than ep-0 */
		for (i = 2; i <= 31; i++) {
			ep_ctx = &dev_ctx->ctx_ep[i];
			ep_ctx->dwEpCtx0 = FIELD_REPLACE( ep_ctx->dwEpCtx0,
			    XHCI_ST_EPCTX_DISABLED, 0x7, 0);
		}

		cmderr = XHCI_TRB_ERROR_SUCCESS;
	}

	pci_xhci_reset_slot(sc, slot);

done:
	return (cmderr);
}

static uint32_t
pci_xhci_cmd_address_device(struct pci_xhci_softc *sc, uint32_t slot,
    struct xhci_trb *trb)
{
	struct pci_xhci_dev_emu	*dev;
	struct xhci_input_dev_ctx *input_ctx;
	struct xhci_slot_ctx	*islot_ctx;
	struct xhci_dev_ctx	*dev_ctx;
	struct xhci_endp_ctx	*ep0_ctx;
	uint32_t		cmderr;

	input_ctx = XHCI_GADDR(sc, trb->qwTrb0 & ~0xFUL);
	islot_ctx = &input_ctx->ctx_slot;
	ep0_ctx = &input_ctx->ctx_ep[1];

	cmderr = XHCI_TRB_ERROR_SUCCESS;

	DPRINTF(("pci_xhci: address device, input ctl: D 0x%08x A 0x%08x,\r\n"
	         "          slot %08x %08x %08x %08x\r\n"
	         "          ep0  %08x %08x %016lx %08x\r\n",
	        input_ctx->ctx_input.dwInCtx0, input_ctx->ctx_input.dwInCtx1,
	        islot_ctx->dwSctx0, islot_ctx->dwSctx1,
	        islot_ctx->dwSctx2, islot_ctx->dwSctx3,
	        ep0_ctx->dwEpCtx0, ep0_ctx->dwEpCtx1, ep0_ctx->qwEpCtx2,
	        ep0_ctx->dwEpCtx4));

	/* when setting address: drop-ctx=0, add-ctx=slot+ep0 */
	if ((input_ctx->ctx_input.dwInCtx0 != 0) ||
	    (input_ctx->ctx_input.dwInCtx1 & 0x03) != 0x03) {
		DPRINTF(("pci_xhci: address device, input ctl invalid\r\n"));
		cmderr = XHCI_TRB_ERROR_TRB;
		goto done;
	}

	/* assign address to slot */
	dev_ctx = pci_xhci_get_dev_ctx(sc, slot);

	DPRINTF(("pci_xhci: address device, dev ctx\r\n"
	         "          slot %08x %08x %08x %08x\r\n",
	        dev_ctx->ctx_slot.dwSctx0, dev_ctx->ctx_slot.dwSctx1,
	        dev_ctx->ctx_slot.dwSctx2, dev_ctx->ctx_slot.dwSctx3));

	dev = XHCI_SLOTDEV_PTR(sc, slot);
	assert(dev != NULL);

	dev->hci.hci_address = slot;
	dev->dev_ctx = dev_ctx;

	if (dev->dev_ue->ue_reset == NULL ||
	    dev->dev_ue->ue_reset(dev->dev_sc) < 0) {
		cmderr = XHCI_TRB_ERROR_ENDP_NOT_ON;
		goto done;
	}

	memcpy(&dev_ctx->ctx_slot, islot_ctx, sizeof(struct xhci_slot_ctx));

	dev_ctx->ctx_slot.dwSctx3 =
	    XHCI_SCTX_3_SLOT_STATE_SET(XHCI_ST_SLCTX_ADDRESSED) |
	    XHCI_SCTX_3_DEV_ADDR_SET(slot);

	memcpy(&dev_ctx->ctx_ep[1], ep0_ctx, sizeof(struct xhci_endp_ctx));
	ep0_ctx = &dev_ctx->ctx_ep[1];
	ep0_ctx->dwEpCtx0 = (ep0_ctx->dwEpCtx0 & ~0x7) |
	    XHCI_EPCTX_0_EPSTATE_SET(XHCI_ST_EPCTX_RUNNING);

	pci_xhci_init_ep(dev, 1);

	dev->dev_slotstate = XHCI_ST_ADDRESSED;

	DPRINTF(("pci_xhci: address device, output ctx\r\n"
	         "          slot %08x %08x %08x %08x\r\n"
	         "          ep0  %08x %08x %016lx %08x\r\n",
	        dev_ctx->ctx_slot.dwSctx0, dev_ctx->ctx_slot.dwSctx1,
	        dev_ctx->ctx_slot.dwSctx2, dev_ctx->ctx_slot.dwSctx3,
	        ep0_ctx->dwEpCtx0, ep0_ctx->dwEpCtx1, ep0_ctx->qwEpCtx2,
	        ep0_ctx->dwEpCtx4));

done:
	return (cmderr);
}

static uint32_t
pci_xhci_cmd_config_ep(struct pci_xhci_softc *sc, uint32_t slot,
    struct xhci_trb *trb)
{
	struct xhci_input_dev_ctx *input_ctx;
	struct pci_xhci_dev_emu	*dev;
	struct xhci_dev_ctx	*dev_ctx;
	struct xhci_endp_ctx	*ep_ctx, *iep_ctx;
	uint32_t	cmderr;
	int		i;

	cmderr = XHCI_TRB_ERROR_SUCCESS;

	DPRINTF(("pci_xhci config_ep slot %u\r\n", slot));

	dev = XHCI_SLOTDEV_PTR(sc, slot);
	assert(dev != NULL);

	if ((trb->dwTrb3 & XHCI_TRB_3_DCEP_BIT) != 0) {
		DPRINTF(("pci_xhci config_ep - deconfigure ep slot %u\r\n",
		        slot));
		if (dev->dev_ue->ue_stop != NULL)
			dev->dev_ue->ue_stop(dev->dev_sc);

		dev->dev_slotstate = XHCI_ST_ADDRESSED;

		dev->hci.hci_address = 0;
		dev_ctx = pci_xhci_get_dev_ctx(sc, slot);

		/* number of contexts */
		dev_ctx->ctx_slot.dwSctx0 = FIELD_REPLACE(
		    dev_ctx->ctx_slot.dwSctx0, 1, 0x1F, 27);

		/* slot state */
		dev_ctx->ctx_slot.dwSctx3 = FIELD_REPLACE(
		    dev_ctx->ctx_slot.dwSctx3, XHCI_ST_SLCTX_ADDRESSED,
		    0x1F, 27);

		/* disable endpoints */
		for (i = 2; i < 32; i++)
			pci_xhci_disable_ep(dev, i);

		cmderr = XHCI_TRB_ERROR_SUCCESS;

		goto done;
	}

	if (dev->dev_slotstate < XHCI_ST_ADDRESSED) {
		DPRINTF(("pci_xhci: config_ep slotstate x%x != addressed\r\n",
		        dev->dev_slotstate));
		cmderr = XHCI_TRB_ERROR_SLOT_NOT_ON;
		goto done;
	}

	/* In addressed/configured state;
	 * for each drop endpoint ctx flag:
	 *   ep->state = DISABLED
	 * for each add endpoint ctx flag:
	 *   cp(ep-in, ep-out)
	 *   ep->state = RUNNING
	 * for each drop+add endpoint flag:
	 *   reset ep resources
	 *   cp(ep-in, ep-out)
	 *   ep->state = RUNNING
	 * if input->DisabledCtx[2-31] < 30: (at least 1 ep not disabled)
	 *   slot->state = configured
	 */

	input_ctx = XHCI_GADDR(sc, trb->qwTrb0 & ~0xFUL);
	dev_ctx = dev->dev_ctx;
	DPRINTF(("pci_xhci: config_ep inputctx: D:x%08x A:x%08x 7:x%08x\r\n",
		input_ctx->ctx_input.dwInCtx0, input_ctx->ctx_input.dwInCtx1,
	        input_ctx->ctx_input.dwInCtx7));

	for (i = 2; i <= 31; i++) {
		ep_ctx = &dev_ctx->ctx_ep[i];

		if (input_ctx->ctx_input.dwInCtx0 &
		    XHCI_INCTX_0_DROP_MASK(i)) {
			DPRINTF((" config ep - dropping ep %d\r\n", i));
			pci_xhci_disable_ep(dev, i);
		}

		if (input_ctx->ctx_input.dwInCtx1 &
		    XHCI_INCTX_1_ADD_MASK(i)) {
			iep_ctx = &input_ctx->ctx_ep[i];

			DPRINTF((" enable ep[%d]  %08x %08x %016lx %08x\r\n",
			   i, iep_ctx->dwEpCtx0, iep_ctx->dwEpCtx1,
			   iep_ctx->qwEpCtx2, iep_ctx->dwEpCtx4));

			memcpy(ep_ctx, iep_ctx, sizeof(struct xhci_endp_ctx));

			pci_xhci_init_ep(dev, i);

			/* ep state */
			ep_ctx->dwEpCtx0 = FIELD_REPLACE(
			    ep_ctx->dwEpCtx0, XHCI_ST_EPCTX_RUNNING, 0x7, 0);
		}
	}

	/* slot state to configured */
	dev_ctx->ctx_slot.dwSctx3 = FIELD_REPLACE(
	    dev_ctx->ctx_slot.dwSctx3, XHCI_ST_SLCTX_CONFIGURED, 0x1F, 27);
	dev_ctx->ctx_slot.dwSctx0 = FIELD_COPY(
	    dev_ctx->ctx_slot.dwSctx0, input_ctx->ctx_slot.dwSctx0, 0x1F, 27);
	dev->dev_slotstate = XHCI_ST_CONFIGURED;

	DPRINTF(("EP configured; slot %u [0]=0x%08x [1]=0x%08x [2]=0x%08x "
	         "[3]=0x%08x\r\n",
	    slot, dev_ctx->ctx_slot.dwSctx0, dev_ctx->ctx_slot.dwSctx1,
	    dev_ctx->ctx_slot.dwSctx2, dev_ctx->ctx_slot.dwSctx3));

done:
	return (cmderr);
}

static uint32_t
pci_xhci_cmd_reset_ep(struct pci_xhci_softc *sc, uint32_t slot,
    struct xhci_trb *trb)
{
	struct pci_xhci_dev_emu	*dev;
	struct pci_xhci_dev_ep *devep;
	struct xhci_dev_ctx	*dev_ctx;
	struct xhci_endp_ctx	*ep_ctx;
	uint32_t	cmderr, epid;
	uint32_t	type;

	epid = XHCI_TRB_3_EP_GET(trb->dwTrb3);

	DPRINTF(("pci_xhci: reset ep %u: slot %u\r\n", epid, slot));

	cmderr = XHCI_TRB_ERROR_SUCCESS;

	type = XHCI_TRB_3_TYPE_GET(trb->dwTrb3);

	dev = XHCI_SLOTDEV_PTR(sc, slot);
	assert(dev != NULL);

	if (type == XHCI_TRB_TYPE_STOP_EP &&
	    (trb->dwTrb3 & XHCI_TRB_3_SUSP_EP_BIT) != 0) {
		/* XXX suspend endpoint for 10ms */
	}

	if (epid < 1 || epid > 31) {
		DPRINTF(("pci_xhci: reset ep: invalid epid %u\r\n", epid));
		cmderr = XHCI_TRB_ERROR_TRB;
		goto done;
	}

	devep = &dev->eps[epid];
	if (devep->ep_xfer != NULL)
		USB_DATA_XFER_RESET(devep->ep_xfer);

	dev_ctx = dev->dev_ctx;
	assert(dev_ctx != NULL);

	ep_ctx = &dev_ctx->ctx_ep[epid];

	ep_ctx->dwEpCtx0 = (ep_ctx->dwEpCtx0 & ~0x7) | XHCI_ST_EPCTX_STOPPED;

	if (XHCI_EPCTX_0_MAXP_STREAMS_GET(ep_ctx->dwEpCtx0) == 0)
		ep_ctx->qwEpCtx2 = devep->ep_ringaddr | devep->ep_ccs;

	DPRINTF(("pci_xhci: reset ep[%u] %08x %08x %016lx %08x\r\n",
	        epid, ep_ctx->dwEpCtx0, ep_ctx->dwEpCtx1, ep_ctx->qwEpCtx2,
	        ep_ctx->dwEpCtx4));

	if (type == XHCI_TRB_TYPE_RESET_EP &&
	    (dev->dev_ue->ue_reset == NULL ||
	    dev->dev_ue->ue_reset(dev->dev_sc) < 0)) {
		cmderr = XHCI_TRB_ERROR_ENDP_NOT_ON;
		goto done;
	}

done:
	return (cmderr);
}


static uint32_t
pci_xhci_find_stream(struct pci_xhci_softc *sc, struct xhci_endp_ctx *ep,
    uint32_t streamid, struct xhci_stream_ctx **osctx)
{
	struct xhci_stream_ctx *sctx;
	uint32_t	maxpstreams;

	maxpstreams = XHCI_EPCTX_0_MAXP_STREAMS_GET(ep->dwEpCtx0);
	if (maxpstreams == 0)
		return (XHCI_TRB_ERROR_TRB);

	if (maxpstreams > XHCI_STREAMS_MAX)
		return (XHCI_TRB_ERROR_INVALID_SID);

	if (XHCI_EPCTX_0_LSA_GET(ep->dwEpCtx0) == 0) {
		DPRINTF(("pci_xhci: find_stream; LSA bit not set\r\n"));
		return (XHCI_TRB_ERROR_INVALID_SID);
	}

	/* only support primary stream */
	if (streamid > maxpstreams)
		return (XHCI_TRB_ERROR_STREAM_TYPE);

	sctx = XHCI_GADDR(sc, ep->qwEpCtx2 & ~0xFUL) + streamid;
	if (!XHCI_SCTX_0_SCT_GET(sctx->qwSctx0))
		return (XHCI_TRB_ERROR_STREAM_TYPE);

	*osctx = sctx;

	return (XHCI_TRB_ERROR_SUCCESS);
}


static uint32_t
pci_xhci_cmd_set_tr(struct pci_xhci_softc *sc, uint32_t slot,
    struct xhci_trb *trb)
{
	struct pci_xhci_dev_emu	*dev;
	struct pci_xhci_dev_ep	*devep;
	struct xhci_dev_ctx	*dev_ctx;
	struct xhci_endp_ctx	*ep_ctx;
	uint32_t	cmderr, epid;
	uint32_t	streamid;

	cmderr = XHCI_TRB_ERROR_SUCCESS;

	dev = XHCI_SLOTDEV_PTR(sc, slot);
	assert(dev != NULL);

	DPRINTF(("pci_xhci set_tr: new-tr x%016lx, SCT %u DCS %u\r\n"
	         "                 stream-id %u, slot %u, epid %u, C %u\r\n",
	         (trb->qwTrb0 & ~0xF),  (uint32_t)((trb->qwTrb0 >> 1) & 0x7),
	         (uint32_t)(trb->qwTrb0 & 0x1), (trb->dwTrb2 >> 16) & 0xFFFF,
	         XHCI_TRB_3_SLOT_GET(trb->dwTrb3),
	         XHCI_TRB_3_EP_GET(trb->dwTrb3), trb->dwTrb3 & 0x1));

	epid = XHCI_TRB_3_EP_GET(trb->dwTrb3);
	if (epid < 1 || epid > 31) {
		DPRINTF(("pci_xhci: set_tr_deq: invalid epid %u\r\n", epid));
		cmderr = XHCI_TRB_ERROR_TRB;
		goto done;
	}

	dev_ctx = dev->dev_ctx;
	assert(dev_ctx != NULL);

	ep_ctx = &dev_ctx->ctx_ep[epid];
	devep = &dev->eps[epid];

	switch (XHCI_EPCTX_0_EPSTATE_GET(ep_ctx->dwEpCtx0)) {
	case XHCI_ST_EPCTX_STOPPED:
	case XHCI_ST_EPCTX_ERROR:
		break;
	default:
		DPRINTF(("pci_xhci cmd set_tr invalid state %x\r\n",
		        XHCI_EPCTX_0_EPSTATE_GET(ep_ctx->dwEpCtx0)));
		cmderr = XHCI_TRB_ERROR_CONTEXT_STATE;
		goto done;
	}

	streamid = XHCI_TRB_2_STREAM_GET(trb->dwTrb2);
	if (XHCI_EPCTX_0_MAXP_STREAMS_GET(ep_ctx->dwEpCtx0) > 0) {
		struct xhci_stream_ctx *sctx;

		sctx = NULL;
		cmderr = pci_xhci_find_stream(sc, ep_ctx, streamid, &sctx);
		if (sctx != NULL) {
			assert(devep->ep_sctx != NULL);

			devep->ep_sctx[streamid].qwSctx0 = trb->qwTrb0;
			devep->ep_sctx_trbs[streamid].ringaddr =
			    trb->qwTrb0 & ~0xF;
			devep->ep_sctx_trbs[streamid].ccs =
			    XHCI_EPCTX_2_DCS_GET(trb->qwTrb0);
		}
	} else {
		if (streamid != 0) {
			DPRINTF(("pci_xhci cmd set_tr streamid %x != 0\r\n",
			        streamid));
		}
		ep_ctx->qwEpCtx2 = trb->qwTrb0 & ~0xFUL;
		devep->ep_ringaddr = ep_ctx->qwEpCtx2 & ~0xFUL;
		devep->ep_ccs = trb->qwTrb0 & 0x1;
		devep->ep_tr = XHCI_GADDR(sc, devep->ep_ringaddr);

		DPRINTF(("pci_xhci set_tr first TRB:\r\n"));
		pci_xhci_dump_trb(devep->ep_tr);
	}
	ep_ctx->dwEpCtx0 = (ep_ctx->dwEpCtx0 & ~0x7) | XHCI_ST_EPCTX_STOPPED;

done:
	return (cmderr);
}

static uint32_t
pci_xhci_cmd_eval_ctx(struct pci_xhci_softc *sc, uint32_t slot,
    struct xhci_trb *trb)
{
	struct xhci_input_dev_ctx *input_ctx;
	struct xhci_slot_ctx      *islot_ctx;
	struct xhci_dev_ctx       *dev_ctx;
	struct xhci_endp_ctx      *ep0_ctx;
	uint32_t cmderr;

	input_ctx = XHCI_GADDR(sc, trb->qwTrb0 & ~0xFUL);
	islot_ctx = &input_ctx->ctx_slot;
	ep0_ctx = &input_ctx->ctx_ep[1];

	cmderr = XHCI_TRB_ERROR_SUCCESS;
	DPRINTF(("pci_xhci: eval ctx, input ctl: D 0x%08x A 0x%08x,\r\n"
	         "          slot %08x %08x %08x %08x\r\n"
	         "          ep0  %08x %08x %016lx %08x\r\n",
	        input_ctx->ctx_input.dwInCtx0, input_ctx->ctx_input.dwInCtx1,
	        islot_ctx->dwSctx0, islot_ctx->dwSctx1,
	        islot_ctx->dwSctx2, islot_ctx->dwSctx3,
	        ep0_ctx->dwEpCtx0, ep0_ctx->dwEpCtx1, ep0_ctx->qwEpCtx2,
	        ep0_ctx->dwEpCtx4));

	/* this command expects drop-ctx=0 & add-ctx=slot+ep0 */
	if ((input_ctx->ctx_input.dwInCtx0 != 0) ||
	    (input_ctx->ctx_input.dwInCtx1 & 0x03) == 0) {
		DPRINTF(("pci_xhci: eval ctx, input ctl invalid\r\n"));
		cmderr = XHCI_TRB_ERROR_TRB;
		goto done;
	}

	/* assign address to slot; in this emulation, slot_id = address */
	dev_ctx = pci_xhci_get_dev_ctx(sc, slot);

	DPRINTF(("pci_xhci: eval ctx, dev ctx\r\n"
	         "          slot %08x %08x %08x %08x\r\n",
	        dev_ctx->ctx_slot.dwSctx0, dev_ctx->ctx_slot.dwSctx1,
	        dev_ctx->ctx_slot.dwSctx2, dev_ctx->ctx_slot.dwSctx3));

	if (input_ctx->ctx_input.dwInCtx1 & 0x01) {	/* slot ctx */
		/* set max exit latency */
		dev_ctx->ctx_slot.dwSctx1 = FIELD_COPY(
		    dev_ctx->ctx_slot.dwSctx1, input_ctx->ctx_slot.dwSctx1,
		    0xFFFF, 0);

		/* set interrupter target */
		dev_ctx->ctx_slot.dwSctx2 = FIELD_COPY(
		    dev_ctx->ctx_slot.dwSctx2, input_ctx->ctx_slot.dwSctx2,
		    0x3FF, 22);
	}
	if (input_ctx->ctx_input.dwInCtx1 & 0x02) {	/* control ctx */
		/* set max packet size */
		dev_ctx->ctx_ep[1].dwEpCtx1 = FIELD_COPY(
		    dev_ctx->ctx_ep[1].dwEpCtx1, ep0_ctx->dwEpCtx1,
		    0xFFFF, 16);

		ep0_ctx = &dev_ctx->ctx_ep[1];
	}

	DPRINTF(("pci_xhci: eval ctx, output ctx\r\n"
	         "          slot %08x %08x %08x %08x\r\n"
	         "          ep0  %08x %08x %016lx %08x\r\n",
	        dev_ctx->ctx_slot.dwSctx0, dev_ctx->ctx_slot.dwSctx1,
	        dev_ctx->ctx_slot.dwSctx2, dev_ctx->ctx_slot.dwSctx3,
	        ep0_ctx->dwEpCtx0, ep0_ctx->dwEpCtx1, ep0_ctx->qwEpCtx2,
	        ep0_ctx->dwEpCtx4));

done:
	return (cmderr);
}

static int
pci_xhci_complete_commands(struct pci_xhci_softc *sc)
{
	struct xhci_trb	evtrb;
	struct xhci_trb	*trb;
	uint64_t	crcr;
	uint32_t	ccs;		/* cycle state (XHCI 4.9.2) */
	uint32_t	type;
	uint32_t	slot;
	uint32_t	cmderr;
	int		error;

	error = 0;
	sc->opregs.crcr |= XHCI_CRCR_LO_CRR;

	trb = sc->opregs.cr_p;
	ccs = sc->opregs.crcr & XHCI_CRCR_LO_RCS;
	crcr = sc->opregs.crcr & ~0xF;

	while (1) {
		sc->opregs.cr_p = trb;

		type = XHCI_TRB_3_TYPE_GET(trb->dwTrb3);

		if ((trb->dwTrb3 & XHCI_TRB_3_CYCLE_BIT) !=
		    (ccs & XHCI_TRB_3_CYCLE_BIT))
			break;

		DPRINTF(("pci_xhci: cmd type 0x%x, Trb0 x%016lx dwTrb2 x%08x"
		        " dwTrb3 x%08x, TRB_CYCLE %u/ccs %u\r\n",
		        type, trb->qwTrb0, trb->dwTrb2, trb->dwTrb3,
		        trb->dwTrb3 & XHCI_TRB_3_CYCLE_BIT, ccs));

		cmderr = XHCI_TRB_ERROR_SUCCESS;
		evtrb.dwTrb2 = 0;
		evtrb.dwTrb3 = (ccs & XHCI_TRB_3_CYCLE_BIT) |
		      XHCI_TRB_3_TYPE_SET(XHCI_TRB_EVENT_CMD_COMPLETE);
		slot = 0;

		switch (type) {
		case XHCI_TRB_TYPE_LINK:			/* 0x06 */
			if (trb->dwTrb3 & XHCI_TRB_3_TC_BIT)
				ccs ^= XHCI_CRCR_LO_RCS;
			break;

		case XHCI_TRB_TYPE_ENABLE_SLOT:			/* 0x09 */
			cmderr = pci_xhci_cmd_enable_slot(sc, &slot);
			break;

		case XHCI_TRB_TYPE_DISABLE_SLOT:		/* 0x0A */
			slot = XHCI_TRB_3_SLOT_GET(trb->dwTrb3);
			cmderr = pci_xhci_cmd_disable_slot(sc, slot);
			break;

		case XHCI_TRB_TYPE_ADDRESS_DEVICE:		/* 0x0B */
			slot = XHCI_TRB_3_SLOT_GET(trb->dwTrb3);
			cmderr = pci_xhci_cmd_address_device(sc, slot, trb);
			break;

		case XHCI_TRB_TYPE_CONFIGURE_EP:		/* 0x0C */
			slot = XHCI_TRB_3_SLOT_GET(trb->dwTrb3);
			cmderr = pci_xhci_cmd_config_ep(sc, slot, trb);
			break;

		case XHCI_TRB_TYPE_EVALUATE_CTX:		/* 0x0D */
			slot = XHCI_TRB_3_SLOT_GET(trb->dwTrb3);
			cmderr = pci_xhci_cmd_eval_ctx(sc, slot, trb);
			break;

		case XHCI_TRB_TYPE_RESET_EP:			/* 0x0E */
			DPRINTF(("Reset Endpoint on slot %d\r\n", slot));
			slot = XHCI_TRB_3_SLOT_GET(trb->dwTrb3);
			cmderr = pci_xhci_cmd_reset_ep(sc, slot, trb);
			break;

		case XHCI_TRB_TYPE_STOP_EP:			/* 0x0F */
			DPRINTF(("Stop Endpoint on slot %d\r\n", slot));
			slot = XHCI_TRB_3_SLOT_GET(trb->dwTrb3);
			cmderr = pci_xhci_cmd_reset_ep(sc, slot, trb);
			break;

		case XHCI_TRB_TYPE_SET_TR_DEQUEUE:		/* 0x10 */
			slot = XHCI_TRB_3_SLOT_GET(trb->dwTrb3);
			cmderr = pci_xhci_cmd_set_tr(sc, slot, trb);
			break;

		case XHCI_TRB_TYPE_RESET_DEVICE:		/* 0x11 */
			slot = XHCI_TRB_3_SLOT_GET(trb->dwTrb3);
			cmderr = pci_xhci_cmd_reset_device(sc, slot);
			break;

		case XHCI_TRB_TYPE_FORCE_EVENT:			/* 0x12 */
			/* TODO: */
			break;

		case XHCI_TRB_TYPE_NEGOTIATE_BW:		/* 0x13 */
			break;

		case XHCI_TRB_TYPE_SET_LATENCY_TOL:		/* 0x14 */
			break;

		case XHCI_TRB_TYPE_GET_PORT_BW:			/* 0x15 */
			break;

		case XHCI_TRB_TYPE_FORCE_HEADER:		/* 0x16 */
			break;

		case XHCI_TRB_TYPE_NOOP_CMD:			/* 0x17 */
			break;

		default:
			DPRINTF(("pci_xhci: unsupported cmd %x\r\n", type));
			break;
		}

		if (type != XHCI_TRB_TYPE_LINK) {
			/*
			 * insert command completion event and assert intr
			 */
			evtrb.qwTrb0 = crcr;
			evtrb.dwTrb2 |= XHCI_TRB_2_ERROR_SET(cmderr);
			evtrb.dwTrb3 |= XHCI_TRB_3_SLOT_SET(slot);
			DPRINTF(("pci_xhci: command 0x%x result: 0x%x\r\n",
			        type, cmderr));
			pci_xhci_insert_event(sc, &evtrb, 1);
		}

		trb = pci_xhci_trb_next(sc, trb, &crcr);
	}

	sc->opregs.crcr = crcr | (sc->opregs.crcr & XHCI_CRCR_LO_CA) | ccs;
	sc->opregs.crcr &= ~XHCI_CRCR_LO_CRR;
	return (error);
}

static void
pci_xhci_dump_trb(struct xhci_trb *trb)
{
	static const char *trbtypes[] = {
		"RESERVED",
		"NORMAL",
		"SETUP_STAGE",
		"DATA_STAGE",
		"STATUS_STAGE",
		"ISOCH",
		"LINK",
		"EVENT_DATA",
		"NOOP",
		"ENABLE_SLOT",
		"DISABLE_SLOT",
		"ADDRESS_DEVICE",
		"CONFIGURE_EP",
		"EVALUATE_CTX",
		"RESET_EP",
		"STOP_EP",
		"SET_TR_DEQUEUE",
		"RESET_DEVICE",
		"FORCE_EVENT",
		"NEGOTIATE_BW",
		"SET_LATENCY_TOL",
		"GET_PORT_BW",
		"FORCE_HEADER",
		"NOOP_CMD"
	};
	uint32_t type;

	type = XHCI_TRB_3_TYPE_GET(trb->dwTrb3);
	DPRINTF(("pci_xhci: trb[@%p] type x%02x %s 0:x%016lx 2:x%08x 3:x%08x\r\n",
	         trb, type,
	         type <= XHCI_TRB_TYPE_NOOP_CMD ? trbtypes[type] : "INVALID",
	         trb->qwTrb0, trb->dwTrb2, trb->dwTrb3));
}

static int
pci_xhci_xfer_complete(struct pci_xhci_softc *sc, struct usb_data_xfer *xfer,
     uint32_t slot, uint32_t epid, int *do_intr)
{
	struct pci_xhci_dev_emu *dev;
	struct pci_xhci_dev_ep	*devep;
	struct xhci_dev_ctx	*dev_ctx;
	struct xhci_endp_ctx	*ep_ctx;
	struct xhci_trb		*trb;
	struct xhci_trb		evtrb;
	uint32_t trbflags;
	uint32_t edtla;
	int i, err;

	dev = XHCI_SLOTDEV_PTR(sc, slot);
	devep = &dev->eps[epid];
	dev_ctx = pci_xhci_get_dev_ctx(sc, slot);

	assert(dev_ctx != NULL);

	ep_ctx = &dev_ctx->ctx_ep[epid];

	err = XHCI_TRB_ERROR_SUCCESS;
	*do_intr = 0;
	edtla = 0;

	/* go through list of TRBs and insert event(s) */
	for (i = xfer->head; xfer->ndata > 0; ) {
		evtrb.qwTrb0 = (uint64_t)xfer->data[i].hci_data;
		trb = XHCI_GADDR(sc, evtrb.qwTrb0);
		trbflags = trb->dwTrb3;

		DPRINTF(("pci_xhci: xfer[%d] done?%u:%d trb %x %016lx %x "
		         "(err %d) IOC?%d\r\n",
		     i, xfer->data[i].processed, xfer->data[i].blen,
		     XHCI_TRB_3_TYPE_GET(trbflags), evtrb.qwTrb0,
		     trbflags, err,
		     trb->dwTrb3 & XHCI_TRB_3_IOC_BIT ? 1 : 0));

		if (!xfer->data[i].processed) {
			xfer->head = i;
			break;
		}

		xfer->ndata--;
		edtla += xfer->data[i].bdone;

		trb->dwTrb3 = (trb->dwTrb3 & ~0x1) | (xfer->data[i].ccs);

		pci_xhci_update_ep_ring(sc, dev, devep, ep_ctx,
		    xfer->data[i].streamid, xfer->data[i].trbnext,
		    xfer->data[i].ccs);

		/* Only interrupt if IOC or short packet */
		if (!(trb->dwTrb3 & XHCI_TRB_3_IOC_BIT) &&
		    !((err == XHCI_TRB_ERROR_SHORT_PKT) &&
		      (trb->dwTrb3 & XHCI_TRB_3_ISP_BIT))) {

			i = (i + 1) % USB_MAX_XFER_BLOCKS;
			continue;
		}

		evtrb.dwTrb2 = XHCI_TRB_2_ERROR_SET(err) |
		               XHCI_TRB_2_REM_SET(xfer->data[i].blen);

		evtrb.dwTrb3 = XHCI_TRB_3_TYPE_SET(XHCI_TRB_EVENT_TRANSFER) |
		    XHCI_TRB_3_SLOT_SET(slot) | XHCI_TRB_3_EP_SET(epid);

		if (XHCI_TRB_3_TYPE_GET(trbflags) == XHCI_TRB_TYPE_EVENT_DATA) {
			DPRINTF(("pci_xhci EVENT_DATA edtla %u\r\n", edtla));
			evtrb.qwTrb0 = trb->qwTrb0;
			evtrb.dwTrb2 = (edtla & 0xFFFFF) |
			         XHCI_TRB_2_ERROR_SET(err);
			evtrb.dwTrb3 |= XHCI_TRB_3_ED_BIT;
			edtla = 0;
		}

		*do_intr = 1;

		err = pci_xhci_insert_event(sc, &evtrb, 0);
		if (err != XHCI_TRB_ERROR_SUCCESS) {
			break;
		}

		i = (i + 1) % USB_MAX_XFER_BLOCKS;
	}

	return (err);
}

static void
pci_xhci_update_ep_ring(struct pci_xhci_softc *sc, struct pci_xhci_dev_emu *dev,
    struct pci_xhci_dev_ep *devep, struct xhci_endp_ctx *ep_ctx,
    uint32_t streamid, uint64_t ringaddr, int ccs)
{

	if (XHCI_EPCTX_0_MAXP_STREAMS_GET(ep_ctx->dwEpCtx0) != 0) {
		devep->ep_sctx[streamid].qwSctx0 = (ringaddr & ~0xFUL) |
		                                   (ccs & 0x1);

		devep->ep_sctx_trbs[streamid].ringaddr = ringaddr & ~0xFUL;
		devep->ep_sctx_trbs[streamid].ccs = ccs & 0x1;
		ep_ctx->qwEpCtx2 = (ep_ctx->qwEpCtx2 & ~0x1) | (ccs & 0x1);

		DPRINTF(("xhci update ep-ring stream %d, addr %lx\r\n",
		    streamid, devep->ep_sctx[streamid].qwSctx0));
	} else {
		devep->ep_ringaddr = ringaddr & ~0xFUL;
		devep->ep_ccs = ccs & 0x1;
		devep->ep_tr = XHCI_GADDR(sc, ringaddr & ~0xFUL);
		ep_ctx->qwEpCtx2 = (ringaddr & ~0xFUL) | (ccs & 0x1);

		DPRINTF(("xhci update ep-ring, addr %lx\r\n",
		    (devep->ep_ringaddr | devep->ep_ccs)));
	}
}

/*
 * Outstanding transfer still in progress (device NAK'd earlier) so retry
 * the transfer again to see if it succeeds.
 */
static int
pci_xhci_try_usb_xfer(struct pci_xhci_softc *sc,
    struct pci_xhci_dev_emu *dev, struct pci_xhci_dev_ep *devep,
    struct xhci_endp_ctx *ep_ctx, uint32_t slot, uint32_t epid)
{
	struct usb_data_xfer *xfer;
	int		err;
	int		do_intr;

	ep_ctx->dwEpCtx0 = FIELD_REPLACE(
		    ep_ctx->dwEpCtx0, XHCI_ST_EPCTX_RUNNING, 0x7, 0);

	err = 0;
	do_intr = 0;

	xfer = devep->ep_xfer;
#ifdef __FreeBSD__
	USB_DATA_XFER_LOCK(xfer);
#else
	/*
	 * At least one caller needs to hold this lock across the call to this
	 * function and other code.  To avoid deadlock from a recursive mutex
	 * enter, we ensure that all callers hold this lock.
	 */
	assert(USB_DATA_XFER_LOCK_HELD(xfer));
#endif

	/* outstanding requests queued up */
	if (dev->dev_ue->ue_data != NULL) {
		err = dev->dev_ue->ue_data(dev->dev_sc, xfer,
		            epid & 0x1 ? USB_XFER_IN : USB_XFER_OUT, epid/2);
		if (err == USB_ERR_CANCELLED) {
			if (USB_DATA_GET_ERRCODE(&xfer->data[xfer->head]) ==
			    USB_NAK)
				err = XHCI_TRB_ERROR_SUCCESS;
		} else {
			err = pci_xhci_xfer_complete(sc, xfer, slot, epid,
			                             &do_intr);
			if (err == XHCI_TRB_ERROR_SUCCESS && do_intr) {
				pci_xhci_assert_interrupt(sc);
			}


			/* XXX should not do it if error? */
			USB_DATA_XFER_RESET(xfer);
		}
	}

#ifdef __FreeBSD__
	USB_DATA_XFER_UNLOCK(xfer);
#endif

	return (err);
}


static int
pci_xhci_handle_transfer(struct pci_xhci_softc *sc,
    struct pci_xhci_dev_emu *dev, struct pci_xhci_dev_ep *devep,
    struct xhci_endp_ctx *ep_ctx, struct xhci_trb *trb, uint32_t slot,
    uint32_t epid, uint64_t addr, uint32_t ccs, uint32_t streamid)
{
	struct xhci_trb *setup_trb;
	struct usb_data_xfer *xfer;
	struct usb_data_xfer_block *xfer_block;
	uint64_t	val;
	uint32_t	trbflags;
	int		do_intr, err;
	int		do_retry;

	ep_ctx->dwEpCtx0 = FIELD_REPLACE(ep_ctx->dwEpCtx0,
	                                 XHCI_ST_EPCTX_RUNNING, 0x7, 0);

	xfer = devep->ep_xfer;
	USB_DATA_XFER_LOCK(xfer);

	DPRINTF(("pci_xhci handle_transfer slot %u\r\n", slot));

retry:
	err = 0;
	do_retry = 0;
	do_intr = 0;
	setup_trb = NULL;

	while (1) {
		pci_xhci_dump_trb(trb);

		trbflags = trb->dwTrb3;

		if (XHCI_TRB_3_TYPE_GET(trbflags) != XHCI_TRB_TYPE_LINK &&
		    (trbflags & XHCI_TRB_3_CYCLE_BIT) !=
		    (ccs & XHCI_TRB_3_CYCLE_BIT)) {
			DPRINTF(("Cycle-bit changed trbflags %x, ccs %x\r\n",
			    trbflags & XHCI_TRB_3_CYCLE_BIT, ccs));
			break;
		}

		xfer_block = NULL;

		switch (XHCI_TRB_3_TYPE_GET(trbflags)) {
		case XHCI_TRB_TYPE_LINK:
			if (trb->dwTrb3 & XHCI_TRB_3_TC_BIT)
				ccs ^= 0x1;

			xfer_block = usb_data_xfer_append(xfer, NULL, 0,
			                                  (void *)addr, ccs);
			xfer_block->processed = 1;
			break;

		case XHCI_TRB_TYPE_SETUP_STAGE:
			if ((trbflags & XHCI_TRB_3_IDT_BIT) == 0 ||
			    XHCI_TRB_2_BYTES_GET(trb->dwTrb2) != 8) {
				DPRINTF(("pci_xhci: invalid setup trb\r\n"));
				err = XHCI_TRB_ERROR_TRB;
				goto errout;
			}
			setup_trb = trb;

			val = trb->qwTrb0;
			if (!xfer->ureq)
				xfer->ureq = malloc(
				           sizeof(struct usb_device_request));
			memcpy(xfer->ureq, &val,
			       sizeof(struct usb_device_request));

			xfer_block = usb_data_xfer_append(xfer, NULL, 0,
			                                  (void *)addr, ccs);
			xfer_block->processed = 1;
			break;

		case XHCI_TRB_TYPE_NORMAL:
		case XHCI_TRB_TYPE_ISOCH:
			if (setup_trb != NULL) {
				DPRINTF(("pci_xhci: trb not supposed to be in "
				         "ctl scope\r\n"));
				err = XHCI_TRB_ERROR_TRB;
				goto errout;
			}
			/* fall through */

		case XHCI_TRB_TYPE_DATA_STAGE:
			xfer_block = usb_data_xfer_append(xfer,
			     (void *)(trbflags & XHCI_TRB_3_IDT_BIT ?
			         &trb->qwTrb0 : XHCI_GADDR(sc, trb->qwTrb0)),
			     trb->dwTrb2 & 0x1FFFF, (void *)addr, ccs);
			break;

		case XHCI_TRB_TYPE_STATUS_STAGE:
			xfer_block = usb_data_xfer_append(xfer, NULL, 0,
			                                  (void *)addr, ccs);
			break;

		case XHCI_TRB_TYPE_NOOP:
			xfer_block = usb_data_xfer_append(xfer, NULL, 0,
			                                  (void *)addr, ccs);
			xfer_block->processed = 1;
			break;

		case XHCI_TRB_TYPE_EVENT_DATA:
			xfer_block = usb_data_xfer_append(xfer, NULL, 0,
			                                  (void *)addr, ccs);
			if ((epid > 1) && (trbflags & XHCI_TRB_3_IOC_BIT)) {
				xfer_block->processed = 1;
			}
			break;

		default:
			DPRINTF(("pci_xhci: handle xfer unexpected trb type "
			         "0x%x\r\n",
			         XHCI_TRB_3_TYPE_GET(trbflags)));
			err = XHCI_TRB_ERROR_TRB;
			goto errout;
		}

		trb = pci_xhci_trb_next(sc, trb, &addr);

		DPRINTF(("pci_xhci: next trb: 0x%lx\r\n", (uint64_t)trb));

		if (xfer_block) {
			xfer_block->trbnext = addr;
			xfer_block->streamid = streamid;
		}

		if (!setup_trb && !(trbflags & XHCI_TRB_3_CHAIN_BIT) &&
		    XHCI_TRB_3_TYPE_GET(trbflags) != XHCI_TRB_TYPE_LINK) {
			break;
		}

		/* handle current batch that requires interrupt on complete */
		if (trbflags & XHCI_TRB_3_IOC_BIT) {
			DPRINTF(("pci_xhci: trb IOC bit set\r\n"));
			if (epid == 1)
				do_retry = 1;
			break;
		}
	}

	DPRINTF(("pci_xhci[%d]: xfer->ndata %u\r\n", __LINE__, xfer->ndata));

	if (epid == 1) {
		err = USB_ERR_NOT_STARTED;
		if (dev->dev_ue->ue_request != NULL)
			err = dev->dev_ue->ue_request(dev->dev_sc, xfer);
		setup_trb = NULL;
	} else {
		/* handle data transfer */
		pci_xhci_try_usb_xfer(sc, dev, devep, ep_ctx, slot, epid);
		err = XHCI_TRB_ERROR_SUCCESS;
		goto errout;
	}

	err = USB_TO_XHCI_ERR(err);
	if ((err == XHCI_TRB_ERROR_SUCCESS) ||
	    (err == XHCI_TRB_ERROR_SHORT_PKT)) {
		err = pci_xhci_xfer_complete(sc, xfer, slot, epid, &do_intr);
		if (err != XHCI_TRB_ERROR_SUCCESS)
			do_retry = 0;
	}

errout:
	if (err == XHCI_TRB_ERROR_EV_RING_FULL)
		DPRINTF(("pci_xhci[%d]: event ring full\r\n", __LINE__));

	if (!do_retry)
		USB_DATA_XFER_UNLOCK(xfer);

	if (do_intr)
		pci_xhci_assert_interrupt(sc);

	if (do_retry) {
		USB_DATA_XFER_RESET(xfer);
		DPRINTF(("pci_xhci[%d]: retry:continuing with next TRBs\r\n",
		         __LINE__));
		goto retry;
	}

	if (epid == 1)
		USB_DATA_XFER_RESET(xfer);

	return (err);
}

static void
pci_xhci_device_doorbell(struct pci_xhci_softc *sc, uint32_t slot,
    uint32_t epid, uint32_t streamid)
{
	struct pci_xhci_dev_emu *dev;
	struct pci_xhci_dev_ep	*devep;
	struct xhci_dev_ctx	*dev_ctx;
	struct xhci_endp_ctx	*ep_ctx;
	struct pci_xhci_trb_ring *sctx_tr;
	struct xhci_trb	*trb;
	uint64_t	ringaddr;
	uint32_t	ccs;

	DPRINTF(("pci_xhci doorbell slot %u epid %u stream %u\r\n",
	    slot, epid, streamid));

	if (slot == 0 || slot > sc->ndevices) {
		DPRINTF(("pci_xhci: invalid doorbell slot %u\r\n", slot));
		return;
	}

	dev = XHCI_SLOTDEV_PTR(sc, slot);
	devep = &dev->eps[epid];
	dev_ctx = pci_xhci_get_dev_ctx(sc, slot);
	if (!dev_ctx) {
		return;
	}
	ep_ctx = &dev_ctx->ctx_ep[epid];

	sctx_tr = NULL;

	DPRINTF(("pci_xhci: device doorbell ep[%u] %08x %08x %016lx %08x\r\n",
	        epid, ep_ctx->dwEpCtx0, ep_ctx->dwEpCtx1, ep_ctx->qwEpCtx2,
	        ep_ctx->dwEpCtx4));

	if (ep_ctx->qwEpCtx2 == 0)
		return;

	/* handle pending transfers */
	if (devep->ep_xfer->ndata > 0) {
#ifndef __FreeBSD__
		USB_DATA_XFER_LOCK(devep->ep_xfer);
#endif
		pci_xhci_try_usb_xfer(sc, dev, devep, ep_ctx, slot, epid);
#ifndef __FreeBSD__
		USB_DATA_XFER_UNLOCK(devep->ep_xfer);
#endif
		return;
	}

	/* get next trb work item */
	if (XHCI_EPCTX_0_MAXP_STREAMS_GET(ep_ctx->dwEpCtx0) != 0) {
		sctx_tr = &devep->ep_sctx_trbs[streamid];
		ringaddr = sctx_tr->ringaddr;
		ccs = sctx_tr->ccs;
		trb = XHCI_GADDR(sc, sctx_tr->ringaddr & ~0xFUL);
		DPRINTF(("doorbell, stream %u, ccs %lx, trb ccs %x\r\n",
		        streamid, ep_ctx->qwEpCtx2 & XHCI_TRB_3_CYCLE_BIT,
		        trb->dwTrb3 & XHCI_TRB_3_CYCLE_BIT));
	} else {
		ringaddr = devep->ep_ringaddr;
		ccs = devep->ep_ccs;
		trb = devep->ep_tr;
		DPRINTF(("doorbell, ccs %lx, trb ccs %x\r\n",
		        ep_ctx->qwEpCtx2 & XHCI_TRB_3_CYCLE_BIT,
		        trb->dwTrb3 & XHCI_TRB_3_CYCLE_BIT));
	}

	if (XHCI_TRB_3_TYPE_GET(trb->dwTrb3) == 0) {
		DPRINTF(("pci_xhci: ring %lx trb[%lx] EP %u is RESERVED?\r\n",
		        ep_ctx->qwEpCtx2, devep->ep_ringaddr, epid));
		return;
	}

	pci_xhci_handle_transfer(sc, dev, devep, ep_ctx, trb, slot, epid,
	                         ringaddr, ccs, streamid);
}

static void
pci_xhci_dbregs_write(struct pci_xhci_softc *sc, uint64_t offset,
    uint64_t value)
{

	offset = (offset - sc->dboff) / sizeof(uint32_t);

	DPRINTF(("pci_xhci: doorbell write offset 0x%lx: 0x%lx\r\n",
	        offset, value));

	if (XHCI_HALTED(sc)) {
		DPRINTF(("pci_xhci: controller halted\r\n"));
		return;
	}

	if (offset == 0)
		pci_xhci_complete_commands(sc);
	else if (sc->portregs != NULL)
		pci_xhci_device_doorbell(sc, offset,
		   XHCI_DB_TARGET_GET(value), XHCI_DB_SID_GET(value));
}

static void
pci_xhci_rtsregs_write(struct pci_xhci_softc *sc, uint64_t offset,
    uint64_t value)
{
	struct pci_xhci_rtsregs *rts;

	offset -= sc->rtsoff;

	if (offset == 0) {
		DPRINTF(("pci_xhci attempted write to MFINDEX\r\n"));
		return;
	}

	DPRINTF(("pci_xhci: runtime regs write offset 0x%lx: 0x%lx\r\n",
	        offset, value));

	offset -= 0x20;		/* start of intrreg */

	rts = &sc->rtsregs;

	switch (offset) {
	case 0x00:
		if (value & XHCI_IMAN_INTR_PEND)
			rts->intrreg.iman &= ~XHCI_IMAN_INTR_PEND;
		rts->intrreg.iman = (value & XHCI_IMAN_INTR_ENA) |
		                    (rts->intrreg.iman & XHCI_IMAN_INTR_PEND);

		if (!(value & XHCI_IMAN_INTR_ENA))
			pci_xhci_deassert_interrupt(sc);

		break;

	case 0x04:
		rts->intrreg.imod = value;
		break;

	case 0x08:
		rts->intrreg.erstsz = value & 0xFFFF;
		break;

	case 0x10:
		/* ERSTBA low bits */
		rts->intrreg.erstba = MASK_64_HI(sc->rtsregs.intrreg.erstba) |
		                      (value & ~0x3F);
		break;

	case 0x14:
		/* ERSTBA high bits */
		rts->intrreg.erstba = (value << 32) |
		    MASK_64_LO(sc->rtsregs.intrreg.erstba);

		rts->erstba_p = XHCI_GADDR(sc,
		                        sc->rtsregs.intrreg.erstba & ~0x3FUL);

		rts->erst_p = XHCI_GADDR(sc,
		              sc->rtsregs.erstba_p->qwEvrsTablePtr & ~0x3FUL);

		rts->er_enq_idx = 0;
		rts->er_events_cnt = 0;

		DPRINTF(("pci_xhci: wr erstba erst (%p) ptr 0x%lx, sz %u\r\n",
		        rts->erstba_p,
		        rts->erstba_p->qwEvrsTablePtr,
		        rts->erstba_p->dwEvrsTableSize));
		break;

	case 0x18:
		/* ERDP low bits */
		rts->intrreg.erdp =
		    MASK_64_HI(sc->rtsregs.intrreg.erdp) |
		    (rts->intrreg.erdp & XHCI_ERDP_LO_BUSY) |
		    (value & ~0xF);
		if (value & XHCI_ERDP_LO_BUSY) {
			rts->intrreg.erdp &= ~XHCI_ERDP_LO_BUSY;
			rts->intrreg.iman &= ~XHCI_IMAN_INTR_PEND;
		}

		rts->er_deq_seg = XHCI_ERDP_LO_SINDEX(value);

		break;

	case 0x1C:
		/* ERDP high bits */
		rts->intrreg.erdp = (value << 32) |
		    MASK_64_LO(sc->rtsregs.intrreg.erdp);

		if (rts->er_events_cnt > 0) {
			uint64_t erdp;
			uint32_t erdp_i;

			erdp = rts->intrreg.erdp & ~0xF;
			erdp_i = (erdp - rts->erstba_p->qwEvrsTablePtr) /
			           sizeof(struct xhci_trb);

			if (erdp_i <= rts->er_enq_idx)
				rts->er_events_cnt = rts->er_enq_idx - erdp_i;
			else
				rts->er_events_cnt =
				          rts->erstba_p->dwEvrsTableSize -
				          (erdp_i - rts->er_enq_idx);

			DPRINTF(("pci_xhci: erdp 0x%lx, events cnt %u\r\n",
			        erdp, rts->er_events_cnt));
		}

		break;

	default:
		DPRINTF(("pci_xhci attempted write to RTS offset 0x%lx\r\n",
		        offset));
		break;
	}
}

static uint64_t
pci_xhci_portregs_read(struct pci_xhci_softc *sc, uint64_t offset)
{
	int port;
	uint32_t *p;

	if (sc->portregs == NULL)
		return (0);

	port = (offset - 0x3F0) / 0x10;

	if (port > XHCI_MAX_DEVS) {
		DPRINTF(("pci_xhci: portregs_read port %d >= XHCI_MAX_DEVS\r\n",
		    port));

		/* return default value for unused port */
		return (XHCI_PS_SPEED_SET(3));
	}

	offset = (offset - 0x3F0) % 0x10;

	p = &sc->portregs[port].portsc;
	p += offset / sizeof(uint32_t);

	DPRINTF(("pci_xhci: portregs read offset 0x%lx port %u -> 0x%x\r\n",
	        offset, port, *p));

	return (*p);
}

static void
pci_xhci_hostop_write(struct pci_xhci_softc *sc, uint64_t offset,
    uint64_t value)
{
	offset -= XHCI_CAPLEN;

	if (offset < 0x400)
		DPRINTF(("pci_xhci: hostop write offset 0x%lx: 0x%lx\r\n",
		         offset, value));

	switch (offset) {
	case XHCI_USBCMD:
		sc->opregs.usbcmd = pci_xhci_usbcmd_write(sc, value & 0x3F0F);
		break;

	case XHCI_USBSTS:
		/* clear bits on write */
		sc->opregs.usbsts &= ~(value &
		      (XHCI_STS_HSE|XHCI_STS_EINT|XHCI_STS_PCD|XHCI_STS_SSS|
		       XHCI_STS_RSS|XHCI_STS_SRE|XHCI_STS_CNR));
		break;

	case XHCI_PAGESIZE:
		/* read only */
		break;

	case XHCI_DNCTRL:
		sc->opregs.dnctrl = value & 0xFFFF;
		break;

	case XHCI_CRCR_LO:
		if (sc->opregs.crcr & XHCI_CRCR_LO_CRR) {
			sc->opregs.crcr &= ~(XHCI_CRCR_LO_CS|XHCI_CRCR_LO_CA);
			sc->opregs.crcr |= value &
			                   (XHCI_CRCR_LO_CS|XHCI_CRCR_LO_CA);
		} else {
			sc->opregs.crcr = MASK_64_HI(sc->opregs.crcr) |
			           (value & (0xFFFFFFC0 | XHCI_CRCR_LO_RCS));
		}
		break;

	case XHCI_CRCR_HI:
		if (!(sc->opregs.crcr & XHCI_CRCR_LO_CRR)) {
			sc->opregs.crcr = MASK_64_LO(sc->opregs.crcr) |
			                  (value << 32);

			sc->opregs.cr_p = XHCI_GADDR(sc,
			                  sc->opregs.crcr & ~0xF);
		}

		if (sc->opregs.crcr & XHCI_CRCR_LO_CS) {
			/* Stop operation of Command Ring */
		}

		if (sc->opregs.crcr & XHCI_CRCR_LO_CA) {
			/* Abort command */
		}

		break;

	case XHCI_DCBAAP_LO:
		sc->opregs.dcbaap = MASK_64_HI(sc->opregs.dcbaap) |
		                    (value & 0xFFFFFFC0);
		break;

	case XHCI_DCBAAP_HI:
		sc->opregs.dcbaap =  MASK_64_LO(sc->opregs.dcbaap) |
		                     (value << 32);
		sc->opregs.dcbaa_p = XHCI_GADDR(sc, sc->opregs.dcbaap & ~0x3FUL);

		DPRINTF(("pci_xhci: opregs dcbaap = 0x%lx (vaddr 0x%lx)\r\n",
		    sc->opregs.dcbaap, (uint64_t)sc->opregs.dcbaa_p));
		break;

	case XHCI_CONFIG:
		sc->opregs.config = value & 0x03FF;
		break;

	default:
		if (offset >= 0x400)
			pci_xhci_portregs_write(sc, offset, value);

		break;
	}
}


static void
pci_xhci_write(struct vmctx *ctx, int vcpu, struct pci_devinst *pi,
                int baridx, uint64_t offset, int size, uint64_t value)
{
	struct pci_xhci_softc *sc;

	sc = pi->pi_arg;

	assert(baridx == 0);


	pthread_mutex_lock(&sc->mtx);
	if (offset < XHCI_CAPLEN)	/* read only registers */
		WPRINTF(("pci_xhci: write RO-CAPs offset %ld\r\n", offset));
	else if (offset < sc->dboff)
		pci_xhci_hostop_write(sc, offset, value);
	else if (offset < sc->rtsoff)
		pci_xhci_dbregs_write(sc, offset, value);
	else if (offset < sc->regsend)
		pci_xhci_rtsregs_write(sc, offset, value);
	else
		WPRINTF(("pci_xhci: write invalid offset %ld\r\n", offset));

	pthread_mutex_unlock(&sc->mtx);
}

static uint64_t
pci_xhci_hostcap_read(struct pci_xhci_softc *sc, uint64_t offset)
{
	uint64_t	value;

	switch (offset) {
	case XHCI_CAPLENGTH:	/* 0x00 */
		value = sc->caplength;
		break;

	case XHCI_HCSPARAMS1:	/* 0x04 */
		value = sc->hcsparams1;
		break;

	case XHCI_HCSPARAMS2:	/* 0x08 */
		value = sc->hcsparams2;
		break;

	case XHCI_HCSPARAMS3:	/* 0x0C */
		value = sc->hcsparams3;
		break;

	case XHCI_HCSPARAMS0:	/* 0x10 */
		value = sc->hccparams1;
		break;

	case XHCI_DBOFF:	/* 0x14 */
		value = sc->dboff;
		break;

	case XHCI_RTSOFF:	/* 0x18 */
		value = sc->rtsoff;
		break;

	case XHCI_HCCPRAMS2:	/* 0x1C */
		value = sc->hccparams2;
		break;

	default:
		value = 0;
		break;
	}

	DPRINTF(("pci_xhci: hostcap read offset 0x%lx -> 0x%lx\r\n",
	        offset, value));

	return (value);
}

static uint64_t
pci_xhci_hostop_read(struct pci_xhci_softc *sc, uint64_t offset)
{
	uint64_t value;

	offset = (offset - XHCI_CAPLEN);

	switch (offset) {
	case XHCI_USBCMD:	/* 0x00 */
		value = sc->opregs.usbcmd;
		break;

	case XHCI_USBSTS:	/* 0x04 */
		value = sc->opregs.usbsts;
		break;

	case XHCI_PAGESIZE:	/* 0x08 */
		value = sc->opregs.pgsz;
		break;

	case XHCI_DNCTRL:	/* 0x14 */
		value = sc->opregs.dnctrl;
		break;

	case XHCI_CRCR_LO:	/* 0x18 */
		value = sc->opregs.crcr & XHCI_CRCR_LO_CRR;
		break;

	case XHCI_CRCR_HI:	/* 0x1C */
		value = 0;
		break;

	case XHCI_DCBAAP_LO:	/* 0x30 */
		value = sc->opregs.dcbaap & 0xFFFFFFFF;
		break;

	case XHCI_DCBAAP_HI:	/* 0x34 */
		value = (sc->opregs.dcbaap >> 32) & 0xFFFFFFFF;
		break;

	case XHCI_CONFIG:	/* 0x38 */
		value = sc->opregs.config;
		break;

	default:
		if (offset >= 0x400)
			value = pci_xhci_portregs_read(sc, offset);
		else
			value = 0;

		break;
	}

	if (offset < 0x400)
		DPRINTF(("pci_xhci: hostop read offset 0x%lx -> 0x%lx\r\n",
		        offset, value));

	return (value);
}

static uint64_t
pci_xhci_dbregs_read(struct pci_xhci_softc *sc, uint64_t offset)
{

	/* read doorbell always returns 0 */
	return (0);
}

static uint64_t
pci_xhci_rtsregs_read(struct pci_xhci_softc *sc, uint64_t offset)
{
	uint32_t	value;

	offset -= sc->rtsoff;
	value = 0;

	if (offset == XHCI_MFINDEX) {
		value = sc->rtsregs.mfindex;
	} else if (offset >= 0x20) {
		int item;
		uint32_t *p;

		offset -= 0x20;
		item = offset % 32;

		assert(offset < sizeof(sc->rtsregs.intrreg));

		p = &sc->rtsregs.intrreg.iman;
		p += item / sizeof(uint32_t);
		value = *p;
	}

	DPRINTF(("pci_xhci: rtsregs read offset 0x%lx -> 0x%x\r\n",
	        offset, value));

	return (value);
}

static uint64_t
pci_xhci_xecp_read(struct pci_xhci_softc *sc, uint64_t offset)
{
	uint32_t	value;

	offset -= sc->regsend;
	value = 0;

	switch (offset) {
	case 0:
		/* rev major | rev minor | next-cap | cap-id */
		value = (0x02 << 24) | (4 << 8) | XHCI_ID_PROTOCOLS;
		break;
	case 4:
		/* name string = "USB" */
		value = 0x20425355;
		break;
	case 8:
		/* psic | proto-defined | compat # | compat offset */
		value = ((XHCI_MAX_DEVS/2) << 8) | sc->usb2_port_start;
		break;
	case 12:
		break;
	case 16:
		/* rev major | rev minor | next-cap | cap-id */
		value = (0x03 << 24) | XHCI_ID_PROTOCOLS;
		break;
	case 20:
		/* name string = "USB" */
		value = 0x20425355;
		break;
	case 24:
		/* psic | proto-defined | compat # | compat offset */
		value = ((XHCI_MAX_DEVS/2) << 8) | sc->usb3_port_start;
		break;
	case 28:
		break;
	default:
		DPRINTF(("pci_xhci: xecp invalid offset 0x%lx\r\n", offset));
		break;
	}

	DPRINTF(("pci_xhci: xecp read offset 0x%lx -> 0x%x\r\n",
	        offset, value));

	return (value);
}


static uint64_t
pci_xhci_read(struct vmctx *ctx, int vcpu, struct pci_devinst *pi, int baridx,
    uint64_t offset, int size)
{
	struct pci_xhci_softc *sc;
	uint32_t	value;

	sc = pi->pi_arg;

	assert(baridx == 0);

	pthread_mutex_lock(&sc->mtx);
	if (offset < XHCI_CAPLEN)
		value = pci_xhci_hostcap_read(sc, offset);
	else if (offset < sc->dboff)
		value = pci_xhci_hostop_read(sc, offset);
	else if (offset < sc->rtsoff)
		value = pci_xhci_dbregs_read(sc, offset);
	else if (offset < sc->regsend)
		value = pci_xhci_rtsregs_read(sc, offset);
	else if (offset < (sc->regsend + 4*32))
		value = pci_xhci_xecp_read(sc, offset);
	else {
		value = 0;
		WPRINTF(("pci_xhci: read invalid offset %ld\r\n", offset));
	}

	pthread_mutex_unlock(&sc->mtx);

	switch (size) {
	case 1:
		value &= 0xFF;
		break;
	case 2:
		value &= 0xFFFF;
		break;
	case 4:
		value &= 0xFFFFFFFF;
		break;
	}

	return (value);
}

static void
pci_xhci_reset_port(struct pci_xhci_softc *sc, int portn, int warm)
{
	struct pci_xhci_portregs *port;
	struct pci_xhci_dev_emu	*dev;
	struct xhci_trb		evtrb;
	int	error;

	assert(portn <= XHCI_MAX_DEVS);

	DPRINTF(("xhci reset port %d\r\n", portn));

	port = XHCI_PORTREG_PTR(sc, portn);
	dev = XHCI_DEVINST_PTR(sc, portn);
	if (dev) {
		port->portsc &= ~(XHCI_PS_PLS_MASK | XHCI_PS_PR | XHCI_PS_PRC);
		port->portsc |= XHCI_PS_PED |
		    XHCI_PS_SPEED_SET(dev->dev_ue->ue_usbspeed);

		if (warm && dev->dev_ue->ue_usbver == 3) {
			port->portsc |= XHCI_PS_WRC;
		}

		if ((port->portsc & XHCI_PS_PRC) == 0) {
			port->portsc |= XHCI_PS_PRC;

			pci_xhci_set_evtrb(&evtrb, portn,
			     XHCI_TRB_ERROR_SUCCESS,
			     XHCI_TRB_EVENT_PORT_STS_CHANGE);
			error = pci_xhci_insert_event(sc, &evtrb, 1);
			if (error != XHCI_TRB_ERROR_SUCCESS)
				DPRINTF(("xhci reset port insert event "
				         "failed\r\n"));
		}
	}
}

static void
pci_xhci_init_port(struct pci_xhci_softc *sc, int portn)
{
	struct pci_xhci_portregs *port;
	struct pci_xhci_dev_emu	*dev;

	port = XHCI_PORTREG_PTR(sc, portn);
	dev = XHCI_DEVINST_PTR(sc, portn);
	if (dev) {
		port->portsc = XHCI_PS_CCS |		/* connected */
		               XHCI_PS_PP;		/* port power */

		if (dev->dev_ue->ue_usbver == 2) {
			port->portsc |= XHCI_PS_PLS_SET(UPS_PORT_LS_POLL) |
		               XHCI_PS_SPEED_SET(dev->dev_ue->ue_usbspeed);
		} else {
			port->portsc |= XHCI_PS_PLS_SET(UPS_PORT_LS_U0) |
		               XHCI_PS_PED |		/* enabled */
		               XHCI_PS_SPEED_SET(dev->dev_ue->ue_usbspeed);
		}

		DPRINTF(("Init port %d 0x%x\n", portn, port->portsc));
	} else {
		port->portsc = XHCI_PS_PLS_SET(UPS_PORT_LS_RX_DET) | XHCI_PS_PP;
		DPRINTF(("Init empty port %d 0x%x\n", portn, port->portsc));
	}
}

static int
pci_xhci_dev_intr(struct usb_hci *hci, int epctx)
{
	struct pci_xhci_dev_emu *dev;
	struct xhci_dev_ctx	*dev_ctx;
	struct xhci_trb		evtrb;
	struct pci_xhci_softc	*sc;
	struct pci_xhci_portregs *p;
	struct xhci_endp_ctx	*ep_ctx;
	int	error;
	int	dir_in;
	int	epid;

	dir_in = epctx & 0x80;
	epid = epctx & ~0x80;

	/* HW endpoint contexts are 0-15; convert to epid based on dir */
	epid = (epid * 2) + (dir_in ? 1 : 0);

	assert(epid >= 1 && epid <= 31);

	dev = hci->hci_sc;
	sc = dev->xsc;

	/* check if device is ready; OS has to initialise it */
	if (sc->rtsregs.erstba_p == NULL ||
	    (sc->opregs.usbcmd & XHCI_CMD_RS) == 0 ||
	    dev->dev_ctx == NULL)
		return (0);

	p = XHCI_PORTREG_PTR(sc, hci->hci_port);

	/* raise event if link U3 (suspended) state */
	if (XHCI_PS_PLS_GET(p->portsc) == 3) {
		p->portsc &= ~XHCI_PS_PLS_MASK;
		p->portsc |= XHCI_PS_PLS_SET(UPS_PORT_LS_RESUME);
		if ((p->portsc & XHCI_PS_PLC) != 0)
			return (0);

		p->portsc |= XHCI_PS_PLC;

		pci_xhci_set_evtrb(&evtrb, hci->hci_port,
		      XHCI_TRB_ERROR_SUCCESS, XHCI_TRB_EVENT_PORT_STS_CHANGE);
		error = pci_xhci_insert_event(sc, &evtrb, 0);
		if (error != XHCI_TRB_ERROR_SUCCESS)
			goto done;
	}

	dev_ctx = dev->dev_ctx;
	ep_ctx = &dev_ctx->ctx_ep[epid];
	if ((ep_ctx->dwEpCtx0 & 0x7) == XHCI_ST_EPCTX_DISABLED) {
		DPRINTF(("xhci device interrupt on disabled endpoint %d\r\n",
		         epid));
		return (0);
	}

	DPRINTF(("xhci device interrupt on endpoint %d\r\n", epid));

	pci_xhci_device_doorbell(sc, hci->hci_port, epid, 0);

done:
	return (error);
}

static int
pci_xhci_dev_event(struct usb_hci *hci, enum hci_usbev evid, void *param)
{

	DPRINTF(("xhci device event port %d\r\n", hci->hci_port));
	return (0);
}



static void
pci_xhci_device_usage(char *opt)
{

	fprintf(stderr, "Invalid USB emulation \"%s\"\r\n", opt);
}

static int
pci_xhci_parse_opts(struct pci_xhci_softc *sc, char *opts)
{
	struct pci_xhci_dev_emu	**devices;
	struct pci_xhci_dev_emu	*dev;
	struct usb_devemu	*ue;
	void	*devsc;
	char	*uopt, *xopts, *config;
	int	usb3_port, usb2_port, i;

	uopt = NULL;
	usb3_port = sc->usb3_port_start - 1;
	usb2_port = sc->usb2_port_start - 1;
	devices = NULL;

	if (opts == NULL)
		goto portsfinal;

	devices = calloc(XHCI_MAX_DEVS, sizeof(struct pci_xhci_dev_emu *));

	sc->slots = calloc(XHCI_MAX_SLOTS, sizeof(struct pci_xhci_dev_emu *));
	sc->devices = devices;
	sc->ndevices = 0;

	uopt = strdup(opts);
	for (xopts = strtok(uopt, ",");
	     xopts != NULL;
	     xopts = strtok(NULL, ",")) {
		if (usb2_port == ((sc->usb2_port_start-1) + XHCI_MAX_DEVS/2) ||
		    usb3_port == ((sc->usb3_port_start-1) + XHCI_MAX_DEVS/2)) {
			WPRINTF(("pci_xhci max number of USB 2 or 3 "
			     "devices reached, max %d\r\n", XHCI_MAX_DEVS/2));
			usb2_port = usb3_port = -1;
			goto done;
		}

		/* device[=<config>] */
		if ((config = strchr(xopts, '=')) == NULL)
			config = "";		/* no config */
		else
			*config++ = '\0';

		ue = usb_emu_finddev(xopts);
		if (ue == NULL) {
			pci_xhci_device_usage(xopts);
			DPRINTF(("pci_xhci device not found %s\r\n", xopts));
			usb2_port = usb3_port = -1;
			goto done;
		}

		DPRINTF(("pci_xhci adding device %s, opts \"%s\"\r\n",
		        xopts, config));

		dev = calloc(1, sizeof(struct pci_xhci_dev_emu));
		dev->xsc = sc;
		dev->hci.hci_sc = dev;
		dev->hci.hci_intr = pci_xhci_dev_intr;
		dev->hci.hci_event = pci_xhci_dev_event;

		if (ue->ue_usbver == 2) {
			dev->hci.hci_port = usb2_port + 1;
			devices[usb2_port] = dev;
			usb2_port++;
		} else {
			dev->hci.hci_port = usb3_port + 1;
			devices[usb3_port] = dev;
			usb3_port++;
		}

		dev->hci.hci_address = 0;
		devsc = ue->ue_init(&dev->hci, config);
		if (devsc == NULL) {
			pci_xhci_device_usage(xopts);
			usb2_port = usb3_port = -1;
			goto done;
		}

		dev->dev_ue = ue;
		dev->dev_sc = devsc;

		/* assign slot number to device */
		sc->slots[sc->ndevices] = dev;

		sc->ndevices++;
	}

portsfinal:
	sc->portregs = calloc(XHCI_MAX_DEVS, sizeof(struct pci_xhci_portregs));

	if (sc->ndevices > 0) {
		/* port and slot numbering start from 1 */
		sc->devices--;
		sc->portregs--;
		sc->slots--;

		for (i = 1; i <= XHCI_MAX_DEVS; i++) {
			pci_xhci_init_port(sc, i);
		}
	} else {
		WPRINTF(("pci_xhci no USB devices configured\r\n"));
		sc->ndevices = 1;
	}

done:
	if (devices != NULL) {
		if (usb2_port <= 0 && usb3_port <= 0) {
			sc->devices = NULL;
			for (i = 0; devices[i] != NULL; i++)
				free(devices[i]);
			sc->ndevices = -1;

			free(devices);
		}
	}
	free(uopt);
	return (sc->ndevices);
}

static int
pci_xhci_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts)
{
	struct pci_xhci_softc *sc;
	int	error;

	if (xhci_in_use) {
		WPRINTF(("pci_xhci controller already defined\r\n"));
		return (-1);
	}
	xhci_in_use = 1;

	sc = calloc(1, sizeof(struct pci_xhci_softc));
	pi->pi_arg = sc;
	sc->xsc_pi = pi;

	sc->usb2_port_start = (XHCI_MAX_DEVS/2) + 1;
	sc->usb3_port_start = 1;

	/* discover devices */
	error = pci_xhci_parse_opts(sc, opts);
	if (error < 0)
		goto done;
	else
		error = 0;

	sc->caplength = XHCI_SET_CAPLEN(XHCI_CAPLEN) |
	                XHCI_SET_HCIVERSION(0x0100);
	sc->hcsparams1 = XHCI_SET_HCSP1_MAXPORTS(XHCI_MAX_DEVS) |
	                 XHCI_SET_HCSP1_MAXINTR(1) |	/* interrupters */
	                 XHCI_SET_HCSP1_MAXSLOTS(XHCI_MAX_SLOTS);
	sc->hcsparams2 = XHCI_SET_HCSP2_ERSTMAX(XHCI_ERST_MAX) |
	                 XHCI_SET_HCSP2_IST(0x04);
	sc->hcsparams3 = 0;				/* no latency */
	sc->hccparams1 = XHCI_SET_HCCP1_NSS(1) |	/* no 2nd-streams */
	                 XHCI_SET_HCCP1_SPC(1) |	/* short packet */
	                 XHCI_SET_HCCP1_MAXPSA(XHCI_STREAMS_MAX);
	sc->hccparams2 = XHCI_SET_HCCP2_LEC(1) |
	                 XHCI_SET_HCCP2_U3C(1);
	sc->dboff = XHCI_SET_DOORBELL(XHCI_CAPLEN + XHCI_PORTREGS_START +
	            XHCI_MAX_DEVS * sizeof(struct pci_xhci_portregs));

	/* dboff must be 32-bit aligned */
	if (sc->dboff & 0x3)
		sc->dboff = (sc->dboff + 0x3) & ~0x3;

	/* rtsoff must be 32-bytes aligned */
	sc->rtsoff = XHCI_SET_RTSOFFSET(sc->dboff + (XHCI_MAX_SLOTS+1) * 32);
	if (sc->rtsoff & 0x1F)
		sc->rtsoff = (sc->rtsoff + 0x1F) & ~0x1F;

	DPRINTF(("pci_xhci dboff: 0x%x, rtsoff: 0x%x\r\n", sc->dboff,
	        sc->rtsoff));

	sc->opregs.usbsts = XHCI_STS_HCH;
	sc->opregs.pgsz = XHCI_PAGESIZE_4K;

	pci_xhci_reset(sc);

	sc->regsend = sc->rtsoff + 0x20 + 32;		/* only 1 intrpter */

	/*
	 * Set extended capabilities pointer to be after regsend;
	 * value of xecp field is 32-bit offset.
	 */
	sc->hccparams1 |= XHCI_SET_HCCP1_XECP(sc->regsend/4);

	pci_set_cfgdata16(pi, PCIR_DEVICE, 0x1E31);
	pci_set_cfgdata16(pi, PCIR_VENDOR, 0x8086);
	pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_SERIALBUS);
	pci_set_cfgdata8(pi, PCIR_SUBCLASS, PCIS_SERIALBUS_USB);
	pci_set_cfgdata8(pi, PCIR_PROGIF,PCIP_SERIALBUS_USB_XHCI);
	pci_set_cfgdata8(pi, PCI_USBREV, PCI_USB_REV_3_0);

	pci_emul_add_msicap(pi, 1);

	/* regsend + xecp registers */
	pci_emul_alloc_bar(pi, 0, PCIBAR_MEM32, sc->regsend + 4*32);
	DPRINTF(("pci_xhci pci_emu_alloc: %d\r\n", sc->regsend + 4*32));


	pci_lintr_request(pi);

	pthread_mutex_init(&sc->mtx, NULL);

done:
	if (error) {
		free(sc);
	}

	return (error);
}



struct pci_devemu pci_de_xhci = {
	.pe_emu =	"xhci",
	.pe_init =	pci_xhci_init,
	.pe_barwrite =	pci_xhci_write,
	.pe_barread =	pci_xhci_read
};
PCI_EMUL_SET(pci_de_xhci);