freebsd-dev/sys/dev/firewire/firewire.c

/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 2003 Hidetoshi Shimokawa
 * Copyright (c) 1998-2002 Katsushi Kobayashi and Hidetoshi Shimokawa
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the acknowledgement as bellow:
 *
 *    This product includes software developed by K. Kobayashi and H. Shimokawa
 *
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/conf.h>
#include <sys/eventhandler.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <sys/systm.h>

#include <sys/kdb.h>
#include <sys/bus.h>		/* used by smbus and newbus */
#include <machine/bus.h>

#include <dev/firewire/firewire.h>
#include <dev/firewire/firewirereg.h>
#include <dev/firewire/fwmem.h>
#include <dev/firewire/iec13213.h>
#include <dev/firewire/iec68113.h>

struct crom_src_buf {
	struct crom_src	src;
	struct crom_chunk root;
	struct crom_chunk vendor;
	struct crom_chunk hw;
};

int firewire_debug = 0, try_bmr = 1, hold_count = 0;
SYSCTL_INT(_debug, OID_AUTO, firewire_debug, CTLFLAG_RW, &firewire_debug, 0,
	"FireWire driver debug flag");
SYSCTL_NODE(_hw, OID_AUTO, firewire, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
    "FireWire Subsystem");
SYSCTL_INT(_hw_firewire, OID_AUTO, try_bmr, CTLFLAG_RW, &try_bmr, 0,
	"Try to be a bus manager");
SYSCTL_INT(_hw_firewire, OID_AUTO, hold_count, CTLFLAG_RW, &hold_count, 0,
	"Number of count of bus resets for removing lost device information");

MALLOC_DEFINE(M_FW, "firewire", "FireWire");
MALLOC_DEFINE(M_FWXFER, "fw_xfer", "XFER/FireWire");

#define FW_MAXASYRTY 4

devclass_t firewire_devclass;

static void firewire_identify(driver_t *, device_t);
static int firewire_probe(device_t);
static int firewire_attach(device_t);
static int firewire_detach(device_t);
static int firewire_resume(device_t);
static void firewire_xfer_timeout(void *, int);
static device_t firewire_add_child(device_t, u_int, const char *, int);
static void fw_try_bmr(void *);
static void fw_try_bmr_callback(struct fw_xfer *);
static void fw_asystart(struct fw_xfer *);
static int fw_get_tlabel(struct firewire_comm *, struct fw_xfer *);
static void fw_bus_probe(void *);
static void fw_attach_dev(struct firewire_comm *);
static void fw_bus_probe_thread(void *);
#ifdef FW_VMACCESS
static void fw_vmaccess (struct fw_xfer *);
#endif
static int fw_bmr (struct firewire_comm *);
static void fw_dump_hdr(struct fw_pkt *, char *);

static device_method_t firewire_methods[] = {
	/* Device interface */
	DEVMETHOD(device_identify,	firewire_identify),
	DEVMETHOD(device_probe,		firewire_probe),
	DEVMETHOD(device_attach,	firewire_attach),
	DEVMETHOD(device_detach,	firewire_detach),
	DEVMETHOD(device_suspend,	bus_generic_suspend),
	DEVMETHOD(device_resume,	firewire_resume),
	DEVMETHOD(device_shutdown,	bus_generic_shutdown),

	/* Bus interface */
	DEVMETHOD(bus_add_child,	firewire_add_child),

	DEVMETHOD_END
};

char *linkspeed[] = {
	"S100", "S200", "S400", "S800",
	"S1600", "S3200", "undef", "undef"
};

static char *tcode_str[] = {
	"WREQQ", "WREQB", "WRES",   "undef",
	"RREQQ", "RREQB", "RRESQ",  "RRESB",
	"CYCS",  "LREQ",  "STREAM", "LRES",
	"undef", "undef", "PHY",    "undef"
};

/* IEEE-1394a Table C-2 Gap count as a function of hops*/
#define MAX_GAPHOP 15
u_int gap_cnt[] = { 5,  5,  7,  8, 10, 13, 16, 18,
		   21, 24, 26, 29, 32, 35, 37, 40};

static driver_t firewire_driver = {
	"firewire",
	firewire_methods,
	sizeof(struct firewire_softc),
};

/*
 * Lookup fwdev by node id.
 */
struct fw_device *
fw_noderesolve_nodeid(struct firewire_comm *fc, int dst)
{
	struct fw_device *fwdev;

	FW_GLOCK(fc);
	STAILQ_FOREACH(fwdev, &fc->devices, link)
		if (fwdev->dst == dst && fwdev->status != FWDEVINVAL)
			break;
	FW_GUNLOCK(fc);

	return fwdev;
}

/*
 * Lookup fwdev by EUI64.
 */
struct fw_device *
fw_noderesolve_eui64(struct firewire_comm *fc, struct fw_eui64 *eui)
{
	struct fw_device *fwdev;

	FW_GLOCK(fc);
	STAILQ_FOREACH(fwdev, &fc->devices, link)
		if (FW_EUI64_EQUAL(fwdev->eui, *eui))
			break;
	FW_GUNLOCK(fc);

	if (fwdev == NULL)
		return NULL;
	if (fwdev->status == FWDEVINVAL)
		return NULL;
	return fwdev;
}

/*
 * Async. request procedure for userland application.
 */
int
fw_asyreq(struct firewire_comm *fc, int sub, struct fw_xfer *xfer)
{
	int err = 0;
	struct fw_xferq *xferq;
	int len;
	struct fw_pkt *fp;
	int tcode;
	struct tcode_info *info;

	if (xfer == NULL)
		return EINVAL;
	if (xfer->hand == NULL) {
		printf("hand == NULL\n");
		return EINVAL;
	}
	fp = &xfer->send.hdr;

	tcode = fp->mode.common.tcode & 0xf;
	info = &fc->tcode[tcode];
	if (info->flag == 0) {
		printf("invalid tcode=%x\n", tcode);
		return EINVAL;
	}

	/* XXX allow bus explore packets only after bus rest */
	if ((fc->status < FWBUSEXPLORE) &&
	    ((tcode != FWTCODE_RREQQ) || (fp->mode.rreqq.dest_hi != 0xffff) ||
	    (fp->mode.rreqq.dest_lo  < 0xf0000000) ||
	    (fp->mode.rreqq.dest_lo >= 0xf0001000))) {
		xfer->resp = EAGAIN;
		xfer->flag = FWXF_BUSY;
		return (EAGAIN);
	}

	if (info->flag & FWTI_REQ)
		xferq = fc->atq;
	else
		xferq = fc->ats;
	len = info->hdr_len;
	if (xfer->send.pay_len > MAXREC(fc->maxrec)) {
		printf("send.pay_len > maxrec\n");
		return EINVAL;
	}
	if (info->flag & FWTI_BLOCK_STR)
		len = fp->mode.stream.len;
	else if (info->flag & FWTI_BLOCK_ASY)
		len = fp->mode.rresb.len;
	else
		len = 0;
	if (len != xfer->send.pay_len) {
		printf("len(%d) != send.pay_len(%d) %s(%x)\n",
		    len, xfer->send.pay_len, tcode_str[tcode], tcode);
		return EINVAL;
	}

	if (xferq->start == NULL) {
		printf("xferq->start == NULL\n");
		return EINVAL;
	}
	if (!(xferq->queued < xferq->maxq)) {
		device_printf(fc->bdev, "Discard a packet (queued=%d)\n",
			xferq->queued);
		return EAGAIN;
	}

	xfer->tl = -1;
	if (info->flag & FWTI_TLABEL) {
		if (fw_get_tlabel(fc, xfer) < 0)
			return EAGAIN;
	}

	xfer->resp = 0;
	xfer->fc = fc;
	xfer->q = xferq;

	fw_asystart(xfer);
	return err;
}

/*
 * Wakeup blocked process.
 */
void
fw_xferwake(struct fw_xfer *xfer)
{
	struct mtx *lock = &xfer->fc->wait_lock;

	mtx_lock(lock);
	xfer->flag |= FWXF_WAKE;
	mtx_unlock(lock);

	wakeup(xfer);
	return;
}

int
fw_xferwait(struct fw_xfer *xfer)
{
	struct mtx *lock = &xfer->fc->wait_lock;
	int err = 0;

	mtx_lock(lock);
	while ((xfer->flag & FWXF_WAKE) == 0)
		err = msleep(xfer, lock, PWAIT|PCATCH, "fw_xferwait", 0);
	mtx_unlock(lock);

	return (err);
}

/*
 * Async. request with given xfer structure.
 */
static void
fw_asystart(struct fw_xfer *xfer)
{
	struct firewire_comm *fc = xfer->fc;

	/* Protect from interrupt/timeout */
	FW_GLOCK(fc);
	xfer->flag = FWXF_INQ;
	STAILQ_INSERT_TAIL(&xfer->q->q, xfer, link);
#if 0
	xfer->q->queued++;
#endif
	FW_GUNLOCK(fc);
	/* XXX just queue for mbuf */
	if (xfer->mbuf == NULL)
		xfer->q->start(fc);
	return;
}

static void
firewire_identify(driver_t *driver, device_t parent)
{
	BUS_ADD_CHILD(parent, 0, "firewire", -1);
}

static int
firewire_probe(device_t dev)
{
	device_set_desc(dev, "IEEE1394(FireWire) bus");
	return (0);
}

/* Just use a per-packet callout? */
static void
firewire_xfer_timeout(void *arg, int pending)
{
	struct firewire_comm *fc = (struct firewire_comm *)arg;
	struct fw_xfer *xfer, *txfer;
	struct timeval tv;
	struct timeval split_timeout;
	STAILQ_HEAD(, fw_xfer) xfer_timeout;
	int i;

	split_timeout.tv_sec = 0;
	split_timeout.tv_usec = 200 * 1000;	 /* 200 msec */

	microtime(&tv);
	timevalsub(&tv, &split_timeout);
	STAILQ_INIT(&xfer_timeout);

	mtx_lock(&fc->tlabel_lock);
	for (i = 0; i < nitems(fc->tlabels); i++) {
		while ((xfer = STAILQ_FIRST(&fc->tlabels[i])) != NULL) {
			if ((xfer->flag & FWXF_SENT) == 0)
				/* not sent yet */
				break;
			if (timevalcmp(&xfer->tv, &tv, >))
				/* the rests are newer than this */
				break;
			device_printf(fc->bdev,
			    "split transaction timeout: tl=0x%x flag=0x%02x\n",
			    i, xfer->flag);
			fw_dump_hdr(&xfer->send.hdr, "send");
			xfer->resp = ETIMEDOUT;
			xfer->tl = -1;
			STAILQ_REMOVE_HEAD(&fc->tlabels[i], tlabel);
			STAILQ_INSERT_TAIL(&xfer_timeout, xfer, tlabel);
		}
	}
	mtx_unlock(&fc->tlabel_lock);
	fc->timeout(fc);

	STAILQ_FOREACH_SAFE(xfer, &xfer_timeout, tlabel, txfer)
		xfer->hand(xfer);
}

#define WATCHDOG_HZ 10
static void
firewire_watchdog(void *arg)
{
	struct firewire_comm *fc;
	static int watchdog_clock = 0;

	fc = arg;

	/*
	 * At boot stage, the device interrupt is disabled and
	 * We encounter a timeout easily. To avoid this,
	 * ignore clock interrupt for a while.
	 */
	if (watchdog_clock > WATCHDOG_HZ * 15)
		taskqueue_enqueue(fc->taskqueue, &fc->task_timeout);
	else
		watchdog_clock++;

	callout_reset(&fc->timeout_callout, hz / WATCHDOG_HZ,
	    firewire_watchdog, fc);
}

/*
 * The attach routine.
 */
static int
firewire_attach(device_t dev)
{
	int unit;
	struct firewire_softc *sc = device_get_softc(dev);
	device_t pa = device_get_parent(dev);
	struct firewire_comm *fc;

	fc = device_get_softc(pa);
	sc->fc = fc;
	fc->status = FWBUSNOTREADY;

	unit = device_get_unit(dev);
	if (fc->nisodma > FWMAXNDMA)
		fc->nisodma = FWMAXNDMA;

	fwdev_makedev(sc);

	fc->crom_src_buf = malloc(sizeof(struct crom_src_buf),
	    M_FW, M_NOWAIT | M_ZERO);
	if (fc->crom_src_buf == NULL) {
		device_printf(fc->dev,
		    "%s: unable to allocate crom src buffer\n", __func__);
		return ENOMEM;
	}
	fc->topology_map = malloc(sizeof(struct fw_topology_map),
	    M_FW, M_NOWAIT | M_ZERO);
	if (fc->topology_map == NULL) {
		device_printf(fc->dev, "%s: unable to allocate topology map\n",
		    __func__);
		free(fc->crom_src_buf, M_FW);
		return ENOMEM;
	}
	fc->speed_map = malloc(sizeof(struct fw_speed_map),
	    M_FW, M_NOWAIT | M_ZERO);
	if (fc->speed_map == NULL) {
		device_printf(fc->dev, "%s: unable to allocate speed map\n",
		    __func__);
		free(fc->crom_src_buf, M_FW);
		free(fc->topology_map, M_FW);
		return ENOMEM;
	}

	mtx_init(&fc->wait_lock, "fwwait", NULL, MTX_DEF);
	mtx_init(&fc->tlabel_lock, "fwtlabel", NULL, MTX_DEF);
	CALLOUT_INIT(&fc->timeout_callout);
	CALLOUT_INIT(&fc->bmr_callout);
	CALLOUT_INIT(&fc->busprobe_callout);
	TASK_INIT(&fc->task_timeout, 0, firewire_xfer_timeout, fc);

	callout_reset(&sc->fc->timeout_callout, hz,
	    firewire_watchdog, sc->fc);

	/* create thread */
	kproc_create(fw_bus_probe_thread, fc, &fc->probe_thread,
	    0, 0, "fw%d_probe", unit);

	/* Locate our children */
	bus_generic_probe(dev);

	/* launch attachement of the added children */
	bus_generic_attach(dev);

	/* bus_reset */
	FW_GLOCK(fc);
	fw_busreset(fc, FWBUSNOTREADY);
	FW_GUNLOCK(fc);
	fc->ibr(fc);

	return 0;
}

/*
 * Attach it as child.
 */
static device_t
firewire_add_child(device_t dev, u_int order, const char *name, int unit)
{
	device_t child;
	struct firewire_softc *sc;

	sc = device_get_softc(dev);
	child = device_add_child(dev, name, unit);
	if (child) {
		device_set_ivars(child, sc->fc);
		device_probe_and_attach(child);
	}

	return child;
}

static int
firewire_resume(device_t dev)
{
	struct firewire_softc *sc;

	sc = device_get_softc(dev);
	sc->fc->status = FWBUSNOTREADY;

	bus_generic_resume(dev);

	return (0);
}

/*
 * Detach it.
 */
static int
firewire_detach(device_t dev)
{
	struct firewire_softc *sc;
	struct firewire_comm *fc;
	struct fw_device *fwdev, *fwdev_next;
	int err;

	sc = device_get_softc(dev);
	fc = sc->fc;
	mtx_lock(&fc->wait_lock);
	fc->status = FWBUSDETACH;
	wakeup(fc);
	if (msleep(fc->probe_thread, &fc->wait_lock, PWAIT, "fwthr", hz * 60))
		printf("firewire probe thread didn't die\n");
	mtx_unlock(&fc->wait_lock);

	if (fc->arq != 0 && fc->arq->maxq > 0)
		fw_drain_txq(fc);

	if ((err = fwdev_destroydev(sc)) != 0)
		return err;

	if ((err = bus_generic_detach(dev)) != 0)
		return err;

	callout_stop(&fc->timeout_callout);
	callout_stop(&fc->bmr_callout);
	callout_stop(&fc->busprobe_callout);

	/* XXX xfer_free and untimeout on all xfers */
	for (fwdev = STAILQ_FIRST(&fc->devices); fwdev != NULL;
	     fwdev = fwdev_next) {
		fwdev_next = STAILQ_NEXT(fwdev, link);
		free(fwdev, M_FW);
	}
	free(fc->topology_map, M_FW);
	free(fc->speed_map, M_FW);
	free(fc->crom_src_buf, M_FW);

	mtx_destroy(&fc->tlabel_lock);
	mtx_destroy(&fc->wait_lock);
	return (0);
}

static void
fw_xferq_drain(struct fw_xferq *xferq)
{
	struct fw_xfer *xfer;

	while ((xfer = STAILQ_FIRST(&xferq->q)) != NULL) {
		STAILQ_REMOVE_HEAD(&xferq->q, link);
#if 0
		xferq->queued--;
#endif
		xfer->resp = EAGAIN;
		xfer->flag = FWXF_SENTERR;
		fw_xfer_done(xfer);
	}
}

void
fw_drain_txq(struct firewire_comm *fc)
{
	struct fw_xfer *xfer, *txfer;
	STAILQ_HEAD(, fw_xfer) xfer_drain;
	int i;

	STAILQ_INIT(&xfer_drain);

	FW_GLOCK(fc);
	fw_xferq_drain(fc->atq);
	fw_xferq_drain(fc->ats);
	for (i = 0; i < fc->nisodma; i++)
		fw_xferq_drain(fc->it[i]);
	FW_GUNLOCK(fc);

	mtx_lock(&fc->tlabel_lock);
	for (i = 0; i < 0x40; i++)
		while ((xfer = STAILQ_FIRST(&fc->tlabels[i])) != NULL) {
			if (firewire_debug)
				printf("tl=%d flag=%d\n", i, xfer->flag);
			xfer->tl = -1;
			xfer->resp = EAGAIN;
			STAILQ_REMOVE_HEAD(&fc->tlabels[i], tlabel);
			STAILQ_INSERT_TAIL(&xfer_drain, xfer, tlabel);
		}
	mtx_unlock(&fc->tlabel_lock);

	STAILQ_FOREACH_SAFE(xfer, &xfer_drain, tlabel, txfer)
		xfer->hand(xfer);
}

static void
fw_reset_csr(struct firewire_comm *fc)
{
	int i;

	CSRARC(fc, STATE_CLEAR)
			= 1 << 23 | 0 << 17 | 1 << 16 | 1 << 15 | 1 << 14;
	CSRARC(fc, STATE_SET) = CSRARC(fc, STATE_CLEAR);
	CSRARC(fc, NODE_IDS) = 0x3f;

	CSRARC(fc, TOPO_MAP + 8) = 0;
	fc->irm = -1;

	fc->max_node = -1;

	for (i = 2; i < 0x100 / 4 - 2; i++) {
		CSRARC(fc, SPED_MAP + i * 4) = 0;
	}
	CSRARC(fc, STATE_CLEAR) = 1 << 23 | 0 << 17 | 1 << 16 | 1 << 15 | 1 << 14;
	CSRARC(fc, STATE_SET) = CSRARC(fc, STATE_CLEAR);
	CSRARC(fc, RESET_START) = 0;
	CSRARC(fc, SPLIT_TIMEOUT_HI) = 0;
	CSRARC(fc, SPLIT_TIMEOUT_LO) = 800 << 19;
	CSRARC(fc, CYCLE_TIME) = 0x0;
	CSRARC(fc, BUS_TIME) = 0x0;
	CSRARC(fc, BUS_MGR_ID) = 0x3f;
	CSRARC(fc, BANDWIDTH_AV) = 4915;
	CSRARC(fc, CHANNELS_AV_HI) = 0xffffffff;
	CSRARC(fc, CHANNELS_AV_LO) = 0xffffffff;
	CSRARC(fc, IP_CHANNELS) = (1U << 31);

	CSRARC(fc, CONF_ROM) = 0x04 << 24;
	CSRARC(fc, CONF_ROM + 4) = 0x31333934; /* means strings 1394 */
	CSRARC(fc, CONF_ROM + 8) = 1 << 31 | 1 << 30 | 1 << 29 |
	    1 << 28 | 0xff << 16 | 0x09 << 8;
	CSRARC(fc, CONF_ROM + 0xc) = 0;

	/* DV depend CSRs see blue book */
	CSRARC(fc, oPCR) &= ~DV_BROADCAST_ON;
	CSRARC(fc, iPCR) &= ~DV_BROADCAST_ON;

	CSRARC(fc, STATE_CLEAR) &= ~(1 << 23 | 1 << 15 | 1 << 14);
	CSRARC(fc, STATE_SET) = CSRARC(fc, STATE_CLEAR);
}

static void
fw_init_crom(struct firewire_comm *fc)
{
	struct crom_src *src;

	src = &fc->crom_src_buf->src;
	bzero(src, sizeof(struct crom_src));

	/* BUS info sample */
	src->hdr.info_len = 4;

	src->businfo.bus_name = CSR_BUS_NAME_IEEE1394;

	src->businfo.irmc = 1;
	src->businfo.cmc = 1;
	src->businfo.isc = 1;
	src->businfo.bmc = 1;
	src->businfo.pmc = 0;
	src->businfo.cyc_clk_acc = 100;
	src->businfo.max_rec = fc->maxrec;
	src->businfo.max_rom = MAXROM_4;
#define FW_GENERATION_CHANGEABLE 2
	src->businfo.generation = FW_GENERATION_CHANGEABLE;
	src->businfo.link_spd = fc->speed;

	src->businfo.eui64.hi = fc->eui.hi;
	src->businfo.eui64.lo = fc->eui.lo;

	STAILQ_INIT(&src->chunk_list);

	fc->crom_src = src;
	fc->crom_root = &fc->crom_src_buf->root;
}

static void
fw_reset_crom(struct firewire_comm *fc)
{
	struct crom_src_buf *buf;
	struct crom_src *src;
	struct crom_chunk *root;

	buf =  fc->crom_src_buf;
	src = fc->crom_src;
	root = fc->crom_root;

	STAILQ_INIT(&src->chunk_list);

	bzero(root, sizeof(struct crom_chunk));
	crom_add_chunk(src, NULL, root, 0);
	crom_add_entry(root, CSRKEY_NCAP, 0x0083c0); /* XXX */
	/* private company_id */
	crom_add_entry(root, CSRKEY_VENDOR, CSRVAL_VENDOR_PRIVATE);
	crom_add_simple_text(src, root, &buf->vendor, "FreeBSD Project");
	crom_add_entry(root, CSRKEY_HW, __FreeBSD_version);
	mtx_lock(&prison0.pr_mtx);
	crom_add_simple_text(src, root, &buf->hw, prison0.pr_hostname);
	mtx_unlock(&prison0.pr_mtx);
}

/*
 * Called after bus reset.
 */
void
fw_busreset(struct firewire_comm *fc, uint32_t new_status)
{
	struct firewire_dev_comm *fdc;
	struct crom_src *src;
	device_t *devlistp;
	uint32_t *newrom;
	int i, devcnt;

	FW_GLOCK_ASSERT(fc);
	if (fc->status == FWBUSMGRELECT)
		callout_stop(&fc->bmr_callout);

	fc->status = new_status;
	fw_reset_csr(fc);

	if (fc->status == FWBUSNOTREADY)
		fw_init_crom(fc);

	fw_reset_crom(fc);

	if (device_get_children(fc->bdev, &devlistp, &devcnt) == 0) {
		for (i = 0; i < devcnt; i++)
			if (device_get_state(devlistp[i]) >= DS_ATTACHED) {
				fdc = device_get_softc(devlistp[i]);
				if (fdc->post_busreset != NULL)
					fdc->post_busreset(fdc);
			}
		free(devlistp, M_TEMP);
	}

	src = &fc->crom_src_buf->src;
	/*
	 * If the old config rom needs to be overwritten,
	 * bump the businfo.generation indicator to
	 * indicate that we need to be reprobed
	 * See 1394a-2000 8.3.2.5.4 for more details.
	 * generation starts at 2 and rolls over at 0xF
	 * back to 2.
	 *
	 * A generation of 0 indicates a device
	 * that is not 1394a-2000 compliant.
	 * A generation of 1 indicates a device that
	 * does not change it's Bus Info Block or
	 * Configuration ROM.
	 */
#define FW_MAX_GENERATION 0xF
	newrom = malloc(CROMSIZE, M_FW, M_NOWAIT | M_ZERO);
	src = &fc->crom_src_buf->src;
	crom_load(src, newrom, CROMSIZE);
	if (bcmp(newrom, fc->config_rom, CROMSIZE) != 0) {
		/* Bump generation and reload. */
		src->businfo.generation++;

		/* Handle generation count wraps. */
		if (src->businfo.generation < FW_GENERATION_CHANGEABLE)
			src->businfo.generation = FW_GENERATION_CHANGEABLE;

		/* Recalculate CRC to account for generation change. */
		crom_load(src, newrom, CROMSIZE);
		bcopy(newrom, fc->config_rom, CROMSIZE);
	}
	free(newrom, M_FW);
}

/* Call once after reboot */
void fw_init(struct firewire_comm *fc)
{
	int i;
#ifdef FW_VMACCESS
	struct fw_xfer *xfer;
	struct fw_bind *fwb;
#endif

	fc->arq->queued = 0;
	fc->ars->queued = 0;
	fc->atq->queued = 0;
	fc->ats->queued = 0;

	fc->arq->buf = NULL;
	fc->ars->buf = NULL;
	fc->atq->buf = NULL;
	fc->ats->buf = NULL;

	fc->arq->flag = 0;
	fc->ars->flag = 0;
	fc->atq->flag = 0;
	fc->ats->flag = 0;

	STAILQ_INIT(&fc->atq->q);
	STAILQ_INIT(&fc->ats->q);

	for (i = 0; i < fc->nisodma; i++) {
		fc->it[i]->queued = 0;
		fc->ir[i]->queued = 0;

		fc->it[i]->start = NULL;
		fc->ir[i]->start = NULL;

		fc->it[i]->buf = NULL;
		fc->ir[i]->buf = NULL;

		fc->it[i]->flag = FWXFERQ_STREAM;
		fc->ir[i]->flag = FWXFERQ_STREAM;

		STAILQ_INIT(&fc->it[i]->q);
		STAILQ_INIT(&fc->ir[i]->q);
	}

	fc->arq->maxq = FWMAXQUEUE;
	fc->ars->maxq = FWMAXQUEUE;
	fc->atq->maxq = FWMAXQUEUE;
	fc->ats->maxq = FWMAXQUEUE;

	for (i = 0; i < fc->nisodma; i++) {
		fc->ir[i]->maxq = FWMAXQUEUE;
		fc->it[i]->maxq = FWMAXQUEUE;
	}

	CSRARC(fc, TOPO_MAP) = 0x3f1 << 16;
	CSRARC(fc, TOPO_MAP + 4) = 1;
	CSRARC(fc, SPED_MAP) = 0x3f1 << 16;
	CSRARC(fc, SPED_MAP + 4) = 1;

	STAILQ_INIT(&fc->devices);

	/* Initialize Async handlers */
	STAILQ_INIT(&fc->binds);
	for (i = 0; i < 0x40; i++) {
		STAILQ_INIT(&fc->tlabels[i]);
	}

/* DV depend CSRs see blue book */
#if 0
	CSRARC(fc, oMPR) = 0x3fff0001; /* # output channel = 1 */
	CSRARC(fc, oPCR) = 0x8000007a;
	for (i = 4; i < 0x7c/4; i += 4) {
		CSRARC(fc, i + oPCR) = 0x8000007a;
	}

	CSRARC(fc, iMPR) = 0x00ff0001; /* # input channel = 1 */
	CSRARC(fc, iPCR) = 0x803f0000;
	for (i = 4; i < 0x7c/4; i += 4) {
		CSRARC(fc, i + iPCR) = 0x0;
	}
#endif

	fc->crom_src_buf = NULL;

#ifdef FW_VMACCESS
	xfer = fw_xfer_alloc();
	if (xfer == NULL)
		return;

	fwb = malloc(sizeof(struct fw_bind), M_FW, M_NOWAIT);
	if (fwb == NULL) {
		fw_xfer_free(xfer);
		return;
	}
	xfer->hand = fw_vmaccess;
	xfer->fc = fc;
	xfer->sc = NULL;

	fwb->start_hi = 0x2;
	fwb->start_lo = 0;
	fwb->addrlen = 0xffffffff;
	fwb->xfer = xfer;
	fw_bindadd(fc, fwb);
#endif
}

#define BIND_CMP(addr, fwb) (((addr) < (fwb)->start)? -1 : \
    ((fwb)->end < (addr)) ? 1 : 0)

/*
 * To lookup bound process from IEEE1394 address.
 */
struct fw_bind *
fw_bindlookup(struct firewire_comm *fc, uint16_t dest_hi, uint32_t dest_lo)
{
	u_int64_t addr;
	struct fw_bind *tfw, *r = NULL;

	addr = ((u_int64_t)dest_hi << 32) | dest_lo;
	FW_GLOCK(fc);
	STAILQ_FOREACH(tfw, &fc->binds, fclist)
		if (BIND_CMP(addr, tfw) == 0) {
			r = tfw;
			break;
		}
	FW_GUNLOCK(fc);
	return (r);
}

/*
 * To bind IEEE1394 address block to process.
 */
int
fw_bindadd(struct firewire_comm *fc, struct fw_bind *fwb)
{
	struct fw_bind *tfw, *prev = NULL;
	int r = 0;

	if (fwb->start > fwb->end) {
		printf("%s: invalid range\n", __func__);
		return EINVAL;
	}

	FW_GLOCK(fc);
	STAILQ_FOREACH(tfw, &fc->binds, fclist) {
		if (fwb->end < tfw->start)
			break;
		prev = tfw;
	}
	if (prev == NULL)
		STAILQ_INSERT_HEAD(&fc->binds, fwb, fclist);
	else if (prev->end < fwb->start)
		STAILQ_INSERT_AFTER(&fc->binds, prev, fwb, fclist);
	else {
		printf("%s: bind failed\n", __func__);
		r = EBUSY;
	}
	FW_GUNLOCK(fc);
	return (r);
}

/*
 * To free IEEE1394 address block.
 */
int
fw_bindremove(struct firewire_comm *fc, struct fw_bind *fwb)
{
#if 0
	struct fw_xfer *xfer, *next;
#endif
	struct fw_bind *tfw;
	int s;

	s = splfw();
	FW_GLOCK(fc);
	STAILQ_FOREACH(tfw, &fc->binds, fclist)
		if (tfw == fwb) {
			STAILQ_REMOVE(&fc->binds, fwb, fw_bind, fclist);
			goto found;
		}

	printf("%s: no such binding\n", __func__);
	FW_GUNLOCK(fc);
	splx(s);
	return (1);
found:
#if 0
	/* shall we do this? */
	for (xfer = STAILQ_FIRST(&fwb->xferlist); xfer != NULL; xfer = next) {
		next = STAILQ_NEXT(xfer, link);
		fw_xfer_free(xfer);
	}
	STAILQ_INIT(&fwb->xferlist);
#endif
	FW_GUNLOCK(fc);

	splx(s);
	return 0;
}

int
fw_xferlist_add(struct fw_xferlist *q, struct malloc_type *type,
    int slen, int rlen, int n,
    struct firewire_comm *fc, void *sc, void (*hand)(struct fw_xfer *))
{
	int i, s;
	struct fw_xfer *xfer;

	for (i = 0; i < n; i++) {
		xfer = fw_xfer_alloc_buf(type, slen, rlen);
		if (xfer == NULL)
			return (i);
		xfer->fc = fc;
		xfer->sc = sc;
		xfer->hand = hand;
		s = splfw();
		STAILQ_INSERT_TAIL(q, xfer, link);
		splx(s);
	}
	return (n);
}

void
fw_xferlist_remove(struct fw_xferlist *q)
{
	struct fw_xfer *xfer, *next;

	for (xfer = STAILQ_FIRST(q); xfer != NULL; xfer = next) {
		next = STAILQ_NEXT(xfer, link);
		fw_xfer_free_buf(xfer);
	}
	STAILQ_INIT(q);
}
/*
 * dump packet header
 */
static void
fw_dump_hdr(struct fw_pkt *fp, char *prefix)
{
	printf("%s: dst=0x%02x tl=0x%02x rt=%d tcode=0x%x pri=0x%x "
	    "src=0x%03x\n", prefix,
	    fp->mode.hdr.dst & 0x3f,
	    fp->mode.hdr.tlrt >> 2, fp->mode.hdr.tlrt & 3,
	    fp->mode.hdr.tcode, fp->mode.hdr.pri,
	    fp->mode.hdr.src);
}

/*
 * To free transaction label.
 */
static void
fw_tl_free(struct firewire_comm *fc, struct fw_xfer *xfer)
{
	struct fw_xfer *txfer;

	mtx_lock(&fc->tlabel_lock);
	if (xfer->tl < 0) {
		mtx_unlock(&fc->tlabel_lock);
		return;
	}
	/* make sure the label is allocated */
	STAILQ_FOREACH(txfer, &fc->tlabels[xfer->tl], tlabel)
		if (txfer == xfer)
			break;
	if (txfer == NULL) {
		printf("%s: the xfer is not in the queue "
		    "(tlabel=%d, flag=0x%x)\n",
		    __FUNCTION__, xfer->tl, xfer->flag);
		fw_dump_hdr(&xfer->send.hdr, "send");
		fw_dump_hdr(&xfer->recv.hdr, "recv");
		kdb_backtrace();
		mtx_unlock(&fc->tlabel_lock);
		return;
	}

	STAILQ_REMOVE(&fc->tlabels[xfer->tl], xfer, fw_xfer, tlabel);
	xfer->tl = -1;
	mtx_unlock(&fc->tlabel_lock);
	return;
}

/*
 * To obtain XFER structure by transaction label.
 */
static struct fw_xfer *
fw_tl2xfer(struct firewire_comm *fc, int node, int tlabel, int tcode)
{
	struct fw_xfer *xfer;
	int s = splfw();
	int req;

	mtx_lock(&fc->tlabel_lock);
	STAILQ_FOREACH(xfer, &fc->tlabels[tlabel], tlabel)
		if (xfer->send.hdr.mode.hdr.dst == node) {
			mtx_unlock(&fc->tlabel_lock);
			splx(s);
			KASSERT(xfer->tl == tlabel,
				("xfer->tl 0x%x != 0x%x", xfer->tl, tlabel));
			/* extra sanity check */
			req = xfer->send.hdr.mode.hdr.tcode;
			if (xfer->fc->tcode[req].valid_res != tcode) {
				printf("%s: invalid response tcode "
				    "(0x%x for 0x%x)\n", __FUNCTION__,
				    tcode, req);
				return (NULL);
			}

			if (firewire_debug > 2)
				printf("fw_tl2xfer: found tl=%d\n", tlabel);
			return (xfer);
		}
	mtx_unlock(&fc->tlabel_lock);
	if (firewire_debug > 1)
		printf("fw_tl2xfer: not found tl=%d\n", tlabel);
	splx(s);
	return (NULL);
}

/*
 * To allocate IEEE1394 XFER structure.
 */
struct fw_xfer *
fw_xfer_alloc(struct malloc_type *type)
{
	struct fw_xfer *xfer;

	xfer = malloc(sizeof(struct fw_xfer), type, M_NOWAIT | M_ZERO);
	if (xfer == NULL)
		return xfer;

	xfer->malloc = type;
	xfer->tl = -1;

	return xfer;
}

struct fw_xfer *
fw_xfer_alloc_buf(struct malloc_type *type, int send_len, int recv_len)
{
	struct fw_xfer *xfer;

	xfer = fw_xfer_alloc(type);
	if (xfer == NULL)
		return (NULL);
	xfer->send.pay_len = send_len;
	xfer->recv.pay_len = recv_len;
	if (send_len > 0) {
		xfer->send.payload = malloc(send_len, type, M_NOWAIT | M_ZERO);
		if (xfer->send.payload == NULL) {
			fw_xfer_free(xfer);
			return (NULL);
		}
	}
	if (recv_len > 0) {
		xfer->recv.payload = malloc(recv_len, type, M_NOWAIT);
		if (xfer->recv.payload == NULL) {
			if (xfer->send.payload != NULL)
				free(xfer->send.payload, type);
			fw_xfer_free(xfer);
			return (NULL);
		}
	}
	return (xfer);
}

/*
 * IEEE1394 XFER post process.
 */
void
fw_xfer_done(struct fw_xfer *xfer)
{
	if (xfer->hand == NULL) {
		printf("hand == NULL\n");
		return;
	}

	if (xfer->fc == NULL)
		panic("fw_xfer_done: why xfer->fc is NULL?");

	fw_tl_free(xfer->fc, xfer);
	xfer->hand(xfer);
}

void
fw_xfer_unload(struct fw_xfer *xfer)
{

	if (xfer == NULL)
		return;

	if (xfer->fc != NULL) {
		FW_GLOCK(xfer->fc);
		if (xfer->flag & FWXF_INQ) {
			STAILQ_REMOVE(&xfer->q->q, xfer, fw_xfer, link);
			xfer->flag &= ~FWXF_INQ;
	#if 0
			xfer->q->queued--;
	#endif
		}
		FW_GUNLOCK(xfer->fc);

		/*
		 * Ensure that any tlabel owner can't access this
		 * xfer after it's freed.
		 */
		fw_tl_free(xfer->fc, xfer);
#if 1
		if (xfer->flag & FWXF_START)
			/*
			 * This could happen if:
			 *  1. We call fwohci_arcv() before fwohci_txd().
			 *  2. firewire_watch() is called.
			 */
			printf("fw_xfer_free FWXF_START\n");
#endif
	}
	xfer->flag = FWXF_INIT;
	xfer->resp = 0;
}

/*
 * To free IEEE1394 XFER structure.
 */
void
fw_xfer_free_buf(struct fw_xfer *xfer)
{
	if (xfer == NULL) {
		printf("%s: xfer == NULL\n", __func__);
		return;
	}
	fw_xfer_unload(xfer);
	if (xfer->send.payload != NULL)
		free(xfer->send.payload, xfer->malloc);
	if (xfer->recv.payload != NULL)
		free(xfer->recv.payload, xfer->malloc);
	free(xfer, xfer->malloc);
}

void
fw_xfer_free(struct fw_xfer *xfer)
{
	if (xfer == NULL) {
		printf("%s: xfer == NULL\n", __func__);
		return;
	}
	fw_xfer_unload(xfer);
	free(xfer, xfer->malloc);
}

void
fw_asy_callback_free(struct fw_xfer *xfer)
{
#if 0
	printf("asyreq done flag=0x%02x resp=%d\n",
				xfer->flag, xfer->resp);
#endif
	fw_xfer_free(xfer);
}

/*
 * To configure PHY.
 */
static void
fw_phy_config(struct firewire_comm *fc, int root_node, int gap_count)
{
	struct fw_xfer *xfer;
	struct fw_pkt *fp;

	fc->status = FWBUSPHYCONF;

	xfer = fw_xfer_alloc(M_FWXFER);
	if (xfer == NULL)
		return;
	xfer->fc = fc;
	xfer->hand = fw_asy_callback_free;

	fp = &xfer->send.hdr;
	fp->mode.ld[1] = 0;
	if (root_node >= 0)
		fp->mode.ld[1] |= (1 << 23) | (root_node & 0x3f) << 24;
	if (gap_count >= 0)
		fp->mode.ld[1] |= (1 << 22) | (gap_count & 0x3f) << 16;
	fp->mode.ld[2] = ~fp->mode.ld[1];
/* XXX Dangerous, how to pass PHY packet to device driver */
	fp->mode.common.tcode |= FWTCODE_PHY;

	if (firewire_debug)
		device_printf(fc->bdev, "%s: root_node=%d gap_count=%d\n",
					__func__, root_node, gap_count);
	fw_asyreq(fc, -1, xfer);
}

/*
 * Dump self ID.
 */
static void
fw_print_sid(uint32_t sid)
{
	union fw_self_id *s;
	s = (union fw_self_id *) &sid;
	if (s->p0.sequel) {
		if (s->p1.sequence_num == FW_SELF_ID_PAGE0) {
			printf("node:%d p3:%d p4:%d p5:%d p6:%d p7:%d"
			    "p8:%d p9:%d p10:%d\n",
			    s->p1.phy_id, s->p1.port3, s->p1.port4,
			    s->p1.port5, s->p1.port6, s->p1.port7,
			    s->p1.port8, s->p1.port9, s->p1.port10);
		} else if (s->p2.sequence_num == FW_SELF_ID_PAGE1) {
			printf("node:%d p11:%d p12:%d p13:%d p14:%d p15:%d\n",
			    s->p2.phy_id, s->p2.port11, s->p2.port12,
			    s->p2.port13, s->p2.port14, s->p2.port15);
		} else {
			printf("node:%d Unknown Self ID Page number %d\n",
			    s->p1.phy_id, s->p1.sequence_num);
		}
	} else {
		printf("node:%d link:%d gap:%d spd:%d con:%d pwr:%d"
		    " p0:%d p1:%d p2:%d i:%d m:%d\n",
		    s->p0.phy_id, s->p0.link_active, s->p0.gap_count,
		    s->p0.phy_speed, s->p0.contender,
		    s->p0.power_class, s->p0.port0, s->p0.port1,
		    s->p0.port2, s->p0.initiated_reset, s->p0.more_packets);
	}
}

/*
 * To receive self ID.
 */
void fw_sidrcv(struct firewire_comm *fc, uint32_t *sid, u_int len)
{
	uint32_t *p;
	union fw_self_id *self_id;
	u_int i, j, node, c_port = 0, i_branch = 0;

	fc->sid_cnt = len / (sizeof(uint32_t) * 2);
	fc->max_node = fc->nodeid & 0x3f;
	CSRARC(fc, NODE_IDS) = ((uint32_t)fc->nodeid) << 16;
	fc->status = FWBUSCYMELECT;
	fc->topology_map->crc_len = 2;
	fc->topology_map->generation++;
	fc->topology_map->self_id_count = 0;
	fc->topology_map->node_count= 0;
	fc->speed_map->generation++;
	fc->speed_map->crc_len = 1 + (64 * 64 + 3) / 4;
	self_id = &fc->topology_map->self_id[0];
	for (i = 0; i < fc->sid_cnt; i++) {
		if (sid[1] != ~sid[0]) {
			device_printf(fc->bdev,
			    "%s: ERROR invalid self-id packet\n", __func__);
			sid += 2;
			continue;
		}
		*self_id = *((union fw_self_id *)sid);
		fc->topology_map->crc_len++;
		if (self_id->p0.sequel == 0) {
			fc->topology_map->node_count++;
			c_port = 0;
			if (firewire_debug)
				fw_print_sid(sid[0]);
			node = self_id->p0.phy_id;
			if (fc->max_node < node)
				fc->max_node = self_id->p0.phy_id;
			/* XXX I'm not sure this is the right speed_map */
			fc->speed_map->speed[node][node] =
			    self_id->p0.phy_speed;
			for (j = 0; j < node; j++) {
				fc->speed_map->speed[j][node] =
				    fc->speed_map->speed[node][j] =
				    min(fc->speed_map->speed[j][j],
					self_id->p0.phy_speed);
			}
			if ((fc->irm == -1 || self_id->p0.phy_id > fc->irm) &&
			  (self_id->p0.link_active && self_id->p0.contender))
				fc->irm = self_id->p0.phy_id;
			if (self_id->p0.port0 >= 0x2)
				c_port++;
			if (self_id->p0.port1 >= 0x2)
				c_port++;
			if (self_id->p0.port2 >= 0x2)
				c_port++;
		}
		if (c_port > 2)
			i_branch += (c_port - 2);
		sid += 2;
		self_id++;
		fc->topology_map->self_id_count++;
	}
	/* CRC */
	fc->topology_map->crc = fw_crc16(
	    (uint32_t *)&fc->topology_map->generation,
	    fc->topology_map->crc_len * 4);
	fc->speed_map->crc = fw_crc16(
	    (uint32_t *)&fc->speed_map->generation,
	    fc->speed_map->crc_len * 4);
	/* byteswap and copy to CSR */
	p = (uint32_t *)fc->topology_map;
	for (i = 0; i <= fc->topology_map->crc_len; i++)
		CSRARC(fc, TOPO_MAP + i * 4) = htonl(*p++);
	p = (uint32_t *)fc->speed_map;
	CSRARC(fc, SPED_MAP) = htonl(*p++);
	CSRARC(fc, SPED_MAP + 4) = htonl(*p++);
	/* don't byte-swap uint8_t array */
	bcopy(p, &CSRARC(fc, SPED_MAP + 8), (fc->speed_map->crc_len - 1) * 4);

	fc->max_hop = fc->max_node - i_branch;
	device_printf(fc->bdev, "%d nodes, maxhop <= %d %s irm(%d) %s\n",
	    fc->max_node + 1, fc->max_hop,
	    (fc->irm == -1) ? "Not IRM capable" : "cable IRM",
	    fc->irm, (fc->irm == fc->nodeid) ? " (me) " : "");

	if (try_bmr && (fc->irm != -1) && (CSRARC(fc, BUS_MGR_ID) == 0x3f)) {
		if (fc->irm == fc->nodeid) {
			fc->status = FWBUSMGRDONE;
			CSRARC(fc, BUS_MGR_ID) = fc->set_bmr(fc, fc->irm);
			fw_bmr(fc);
		} else {
			fc->status = FWBUSMGRELECT;
			callout_reset(&fc->bmr_callout, hz / 8,
			    fw_try_bmr, fc);
		}
	} else
		fc->status = FWBUSMGRDONE;

	callout_reset(&fc->busprobe_callout, hz / 4, fw_bus_probe, fc);
}

/*
 * To probe devices on the IEEE1394 bus.
 */
static void
fw_bus_probe(void *arg)
{
	struct firewire_comm *fc;
	struct fw_device *fwdev;
	int s;

	s = splfw();
	fc = arg;
	fc->status = FWBUSEXPLORE;

	/* Invalidate all devices, just after bus reset. */
	if (firewire_debug)
		device_printf(fc->bdev, "%s:"
			"iterate and invalidate all nodes\n",
			__func__);
	STAILQ_FOREACH(fwdev, &fc->devices, link)
		if (fwdev->status != FWDEVINVAL) {
			fwdev->status = FWDEVINVAL;
			fwdev->rcnt = 0;
			if (firewire_debug)
				device_printf(fc->bdev, "%s:"
					"Invalidate Dev ID: %08x%08x\n",
					__func__, fwdev->eui.hi, fwdev->eui.lo);
		} else {
			if (firewire_debug)
				device_printf(fc->bdev, "%s:"
					"Dev ID: %08x%08x already invalid\n",
					__func__, fwdev->eui.hi, fwdev->eui.lo);
		}
	splx(s);

	wakeup(fc);
}

static int
fw_explore_read_quads(struct fw_device *fwdev, int offset,
    uint32_t *quad, int length)
{
	struct fw_xfer *xfer;
	uint32_t tmp;
	int i, error;

	for (i = 0; i < length; i++, offset += sizeof(uint32_t)) {
		xfer = fwmem_read_quad(fwdev, NULL, -1, 0xffff,
		    0xf0000000 | offset, &tmp, fw_xferwake);
		if (xfer == NULL)
			return (-1);
		fw_xferwait(xfer);

		if (xfer->resp == 0)
			quad[i] = ntohl(tmp);

		error = xfer->resp;
		fw_xfer_free(xfer);
		if (error)
			return (error);
	}
	return (0);
}


static int
fw_explore_csrblock(struct fw_device *fwdev, int offset, int recur)
{
	int err, i, off;
	struct csrdirectory *dir;
	struct csrreg *reg;

	dir = (struct csrdirectory *)&fwdev->csrrom[offset / sizeof(uint32_t)];
	err = fw_explore_read_quads(fwdev, CSRROMOFF + offset,
	    (uint32_t *)dir, 1);
	if (err)
		return (-1);

	offset += sizeof(uint32_t);
	reg = (struct csrreg *)&fwdev->csrrom[offset / sizeof(uint32_t)];
	err = fw_explore_read_quads(fwdev, CSRROMOFF + offset,
	    (uint32_t *)reg, dir->crc_len);
	if (err)
		return (-1);

	/* XXX check CRC */

	off = CSRROMOFF + offset + sizeof(uint32_t) * (dir->crc_len - 1);
	if (fwdev->rommax < off)
		fwdev->rommax = off;

	if (recur == 0)
		return (0);

	for (i = 0; i < dir->crc_len; i++, offset += sizeof(uint32_t)) {
		if ((reg[i].key & CSRTYPE_MASK) == CSRTYPE_D)
			recur = 1;
		else if ((reg[i].key & CSRTYPE_MASK) == CSRTYPE_L)
			recur = 0;
		else
			continue;

		off = offset + reg[i].val * sizeof(uint32_t);
		if (off > CROMSIZE) {
			printf("%s: invalid offset %d\n", __FUNCTION__, off);
			return (-1);
		}
		err = fw_explore_csrblock(fwdev, off, recur);
		if (err)
			return (-1);
	}
	return (0);
}

static int
fw_explore_node(struct fw_device *dfwdev)
{
	struct firewire_comm *fc;
	struct fw_device *fwdev, *pfwdev, *tfwdev;
	uint32_t *csr;
	struct csrhdr *hdr;
	struct bus_info *binfo;
	int err, node;
	uint32_t speed_test = 0;

	fc = dfwdev->fc;
	csr = dfwdev->csrrom;
	node = dfwdev->dst;

	/* First quad */
	err = fw_explore_read_quads(dfwdev, CSRROMOFF, &csr[0], 1);
	if (err) {
		dfwdev->status = FWDEVINVAL;
		return (-1);
	}
	hdr = (struct csrhdr *)&csr[0];
	if (hdr->info_len != 4) {
		if (firewire_debug)
			device_printf(fc->bdev,
			    "%s: node%d: wrong bus info len(%d)\n",
			    __func__, node, hdr->info_len);
		dfwdev->status = FWDEVINVAL;
		return (-1);
	}

	/* bus info */
	err = fw_explore_read_quads(dfwdev, CSRROMOFF + 0x04, &csr[1], 4);
	if (err) {
		dfwdev->status = FWDEVINVAL;
		return (-1);
	}
	binfo = (struct bus_info *)&csr[1];
	if (binfo->bus_name != CSR_BUS_NAME_IEEE1394) {
		dfwdev->status = FWDEVINVAL;
		return (-1);
	}

	if (firewire_debug)
		device_printf(fc->bdev, "%s: node(%d) BUS INFO BLOCK:\n"
		    "irmc(%d) cmc(%d) isc(%d) bmc(%d) pmc(%d) "
		    "cyc_clk_acc(%d) max_rec(%d) max_rom(%d) "
		    "generation(%d) link_spd(%d)\n",
		    __func__, node,
		    binfo->irmc, binfo->cmc, binfo->isc,
		    binfo->bmc, binfo->pmc, binfo->cyc_clk_acc,
		    binfo->max_rec, binfo->max_rom,
		    binfo->generation, binfo->link_spd);

	STAILQ_FOREACH(fwdev, &fc->devices, link)
		if (FW_EUI64_EQUAL(fwdev->eui, binfo->eui64))
			break;
	if (fwdev == NULL) {
		/* new device */
		fwdev = malloc(sizeof(struct fw_device), M_FW,
		    M_NOWAIT | M_ZERO);
		if (fwdev == NULL) {
			device_printf(fc->bdev, "%s: node%d: no memory\n",
					__func__, node);
			return (-1);
		}
		fwdev->fc = fc;
		fwdev->eui = binfo->eui64;
		fwdev->dst = dfwdev->dst;
		fwdev->maxrec = dfwdev->maxrec;
		fwdev->status = dfwdev->status;

		/*
		 * Pre-1394a-2000 didn't have link_spd in
		 * the Bus Info block, so try and use the
		 * speed map value.
		 * 1394a-2000 compliant devices only use
		 * the Bus Info Block link spd value, so
		 * ignore the speed map altogether. SWB
		 */
		if (binfo->link_spd == FWSPD_S100 /* 0 */) {
			device_printf(fc->bdev, "%s: "
			    "Pre 1394a-2000 detected\n", __func__);
			fwdev->speed = fc->speed_map->speed[fc->nodeid][node];
		} else
			fwdev->speed = binfo->link_spd;
		/*
		 * Test this speed with a read to the CSRROM.
		 * If it fails, slow down the speed and retry.
		 */
		while (fwdev->speed > FWSPD_S100 /* 0 */) {
			err = fw_explore_read_quads(fwdev, CSRROMOFF,
			    &speed_test, 1);
			if (err) {
				device_printf(fc->bdev,
				    "%s: fwdev->speed(%s) decremented due to negotiation\n",
				    __func__, linkspeed[fwdev->speed]);
				fwdev->speed--;
			} else
				break;

		}

		/*
		 * If the fwdev is not found in the
		 * fc->devices TAILQ, then we will add it.
		 */
		pfwdev = NULL;
		STAILQ_FOREACH(tfwdev, &fc->devices, link) {
			if (tfwdev->eui.hi > fwdev->eui.hi ||
				(tfwdev->eui.hi == fwdev->eui.hi &&
				tfwdev->eui.lo > fwdev->eui.lo))
				break;
			pfwdev = tfwdev;
		}
		if (pfwdev == NULL)
			STAILQ_INSERT_HEAD(&fc->devices, fwdev, link);
		else
			STAILQ_INSERT_AFTER(&fc->devices, pfwdev, fwdev, link);
	} else {
		fwdev->dst = node;
		fwdev->status = FWDEVINIT;
		/* unchanged ? */
		if (bcmp(&csr[0], &fwdev->csrrom[0], sizeof(uint32_t) * 5) == 0) {
			if (firewire_debug)
				device_printf(fc->dev,
				    "node%d: crom unchanged\n", node);
			return (0);
		}
	}

	bzero(&fwdev->csrrom[0], CROMSIZE);

	/* copy first quad and bus info block */
	bcopy(&csr[0], &fwdev->csrrom[0], sizeof(uint32_t) * 5);
	fwdev->rommax = CSRROMOFF + sizeof(uint32_t) * 4;

	err = fw_explore_csrblock(fwdev, 0x14, 1); /* root directory */

	if (err) {
		if (firewire_debug)
			device_printf(fc->dev, "%s: explore csrblock failed err(%d)\n",
					__func__, err);
		fwdev->status = FWDEVINVAL;
		fwdev->csrrom[0] = 0;
	}
	return (err);

}

/*
 * Find the self_id packet for a node, ignoring sequels.
 */
static union fw_self_id *
fw_find_self_id(struct firewire_comm *fc, int node)
{
	uint32_t i;
	union fw_self_id *s;

	for (i = 0; i < fc->topology_map->self_id_count; i++) {
		s = &fc->topology_map->self_id[i];
		if (s->p0.sequel)
			continue;
		if (s->p0.phy_id == node)
			return s;
	}
	return 0;
}

static void
fw_explore(struct firewire_comm *fc)
{
	int node, err, s, i, todo, todo2, trys;
	char nodes[63];
	struct fw_device dfwdev;
	union fw_self_id *fwsid;

	todo = 0;
	/* setup dummy fwdev */
	dfwdev.fc = fc;
	dfwdev.speed = 0;
	dfwdev.maxrec = 8; /* 512 */
	dfwdev.status = FWDEVINIT;

	for (node = 0; node <= fc->max_node; node++) {
		/* We don't probe myself and linkdown nodes */
		if (node == fc->nodeid) {
			if (firewire_debug)
				device_printf(fc->bdev, "%s:"
				    "found myself node(%d) fc->nodeid(%d) fc->max_node(%d)\n",
				    __func__, node, fc->nodeid, fc->max_node);
			continue;
		} else if (firewire_debug) {
			device_printf(fc->bdev, "%s:"
			    "node(%d) fc->max_node(%d) found\n",
			    __func__, node, fc->max_node);
		}
		fwsid = fw_find_self_id(fc, node);
		if (!fwsid || !fwsid->p0.link_active) {
			if (firewire_debug)
				device_printf(fc->bdev,
				    "%s: node%d: link down\n",
				    __func__, node);
			continue;
		}
		nodes[todo++] = node;
	}

	s = splfw();
	for (trys = 0; todo > 0 && trys < 3; trys++) {
		todo2 = 0;
		for (i = 0; i < todo; i++) {
			dfwdev.dst = nodes[i];
			err = fw_explore_node(&dfwdev);
			if (err)
				nodes[todo2++] = nodes[i];
			if (firewire_debug)
				device_printf(fc->bdev,
				    "%s: node %d, err = %d\n",
				    __func__, node, err);
		}
		todo = todo2;
	}
	splx(s);
}

static void
fw_bus_probe_thread(void *arg)
{
	struct firewire_comm *fc;

	fc = arg;

	mtx_lock(&fc->wait_lock);
	while (fc->status != FWBUSDETACH) {
		if (fc->status == FWBUSEXPLORE) {
			mtx_unlock(&fc->wait_lock);
			fw_explore(fc);
			fc->status = FWBUSEXPDONE;
			if (firewire_debug)
				printf("bus_explore done\n");
			fw_attach_dev(fc);
			mtx_lock(&fc->wait_lock);
		}
		msleep((void *)fc, &fc->wait_lock, PWAIT|PCATCH, "-", 0);
	}
	mtx_unlock(&fc->wait_lock);
	kproc_exit(0);
}

/*
 * To attach sub-devices layer onto IEEE1394 bus.
 */
static void
fw_attach_dev(struct firewire_comm *fc)
{
	struct fw_device *fwdev, *next;
	int i, err;
	device_t *devlistp;
	int devcnt;
	struct firewire_dev_comm *fdc;

	for (fwdev = STAILQ_FIRST(&fc->devices); fwdev != NULL; fwdev = next) {
		next = STAILQ_NEXT(fwdev, link);
		if (fwdev->status == FWDEVINIT) {
			fwdev->status = FWDEVATTACHED;
		} else if (fwdev->status == FWDEVINVAL) {
			fwdev->rcnt++;
			if (firewire_debug)
				device_printf(fc->bdev, "%s:"
				    "fwdev->rcnt(%d), hold_count(%d)\n",
				    __func__, fwdev->rcnt, hold_count);
			if (fwdev->rcnt > hold_count) {
				/*
				 * Remove devices which have not been seen
				 * for a while.
				 */
				STAILQ_REMOVE(&fc->devices, fwdev, fw_device,
				    link);
				free(fwdev, M_FW);
			}
		}
	}

	err = device_get_children(fc->bdev, &devlistp, &devcnt);
	if (err == 0) {
		for (i = 0; i < devcnt; i++) {
			if (device_get_state(devlistp[i]) >= DS_ATTACHED) {
				fdc = device_get_softc(devlistp[i]);
				if (fdc->post_explore != NULL)
					fdc->post_explore(fdc);
			}
		}
		free(devlistp, M_TEMP);
	}

	return;
}

/*
 * To allocate unique transaction label.
 */
static int
fw_get_tlabel(struct firewire_comm *fc, struct fw_xfer *xfer)
{
	u_int dst, new_tlabel;
	struct fw_xfer *txfer;
	int s;

	dst = xfer->send.hdr.mode.hdr.dst & 0x3f;
	s = splfw();
	mtx_lock(&fc->tlabel_lock);
	new_tlabel = (fc->last_tlabel[dst] + 1) & 0x3f;
	STAILQ_FOREACH(txfer, &fc->tlabels[new_tlabel], tlabel)
		if ((txfer->send.hdr.mode.hdr.dst & 0x3f) == dst)
			break;
	if (txfer == NULL) {
		fc->last_tlabel[dst] = new_tlabel;
		STAILQ_INSERT_TAIL(&fc->tlabels[new_tlabel], xfer, tlabel);
		mtx_unlock(&fc->tlabel_lock);
		splx(s);
		xfer->tl = new_tlabel;
		xfer->send.hdr.mode.hdr.tlrt = new_tlabel << 2;
		if (firewire_debug > 1)
			printf("fw_get_tlabel: dst=%d tl=%d\n", dst, new_tlabel);
		return (new_tlabel);
	}
	mtx_unlock(&fc->tlabel_lock);
	splx(s);

	if (firewire_debug > 1)
		printf("fw_get_tlabel: no free tlabel\n");
	return (-1);
}

static void
fw_rcv_copy(struct fw_rcv_buf *rb)
{
	struct fw_pkt *pkt;
	u_char *p;
	struct tcode_info *tinfo;
	u_int res, i, len, plen;

	rb->xfer->recv.spd = rb->spd;

	pkt = (struct fw_pkt *)rb->vec->iov_base;
	tinfo = &rb->fc->tcode[pkt->mode.hdr.tcode];

	/* Copy header */
	p = (u_char *)&rb->xfer->recv.hdr;
	bcopy(rb->vec->iov_base, p, tinfo->hdr_len);
	rb->vec->iov_base = (u_char *)rb->vec->iov_base + tinfo->hdr_len;
	rb->vec->iov_len -= tinfo->hdr_len;

	/* Copy payload */
	p = (u_char *)rb->xfer->recv.payload;
	res = rb->xfer->recv.pay_len;

	/* special handling for RRESQ */
	if (pkt->mode.hdr.tcode == FWTCODE_RRESQ &&
	    p != NULL && res >= sizeof(uint32_t)) {
		*(uint32_t *)p = pkt->mode.rresq.data;
		rb->xfer->recv.pay_len = sizeof(uint32_t);
		return;
	}

	if ((tinfo->flag & FWTI_BLOCK_ASY) == 0)
		return;

	plen = pkt->mode.rresb.len;

	for (i = 0; i < rb->nvec; i++, rb->vec++) {
		len = MIN(rb->vec->iov_len, plen);
		if (res < len) {
			device_printf(rb->fc->bdev, "%s:"
				" rcv buffer(%d) is %d bytes short.\n",
				__func__, rb->xfer->recv.pay_len, len - res);
			len = res;
		}
		bcopy(rb->vec->iov_base, p, len);
		p += len;
		res -= len;
		plen -= len;
		if (res == 0 || plen == 0)
			break;
	}
	rb->xfer->recv.pay_len -= res;
}

/*
 * Generic packet receiving process.
 */
void
fw_rcv(struct fw_rcv_buf *rb)
{
	struct fw_pkt *fp, *resfp;
	struct fw_bind *bind;
	int tcode;
	int i, len, oldstate;
#if 0
	{
		uint32_t *qld;
		int i;
		qld = (uint32_t *)buf;
		printf("spd %d len:%d\n", spd, len);
		for (i = 0; i <= len && i < 32; i+= 4) {
			printf("0x%08x ", ntohl(qld[i/4]));
			if ((i % 16) == 15) printf("\n");
		}
		if ((i % 16) != 15) printf("\n");
	}
#endif
	fp = (struct fw_pkt *)rb->vec[0].iov_base;
	tcode = fp->mode.common.tcode;
	switch (tcode) {
	case FWTCODE_WRES:
	case FWTCODE_RRESQ:
	case FWTCODE_RRESB:
	case FWTCODE_LRES:
		rb->xfer = fw_tl2xfer(rb->fc, fp->mode.hdr.src,
				fp->mode.hdr.tlrt >> 2, fp->mode.hdr.tcode);
		if (rb->xfer == NULL) {
			device_printf(rb->fc->bdev, "%s: unknown response "
			    "%s(%x) src=0x%x tl=0x%x rt=%d data=0x%x\n",
			    __func__,
			    tcode_str[tcode], tcode,
			    fp->mode.hdr.src,
			    fp->mode.hdr.tlrt >> 2,
			    fp->mode.hdr.tlrt & 3,
			    fp->mode.rresq.data);
#if 0
			printf("try ad-hoc work around!!\n");
			rb->xfer = fw_tl2xfer(rb->fc, fp->mode.hdr.src,
			    (fp->mode.hdr.tlrt >> 2)^3);
			if (rb->xfer == NULL) {
				printf("no use...\n");
				return;
			}
#else
			return;
#endif
		}
		fw_rcv_copy(rb);
		if (rb->xfer->recv.hdr.mode.wres.rtcode != RESP_CMP)
			rb->xfer->resp = EIO;
		else
			rb->xfer->resp = 0;
		/* make sure the packet is drained in AT queue */
		oldstate = rb->xfer->flag;
		rb->xfer->flag = FWXF_RCVD;
		switch (oldstate) {
		case FWXF_SENT:
			fw_xfer_done(rb->xfer);
			break;
		case FWXF_START:
#if 0
			if (firewire_debug)
				printf("not sent yet tl=%x\n", rb->xfer->tl);
#endif
			break;
		default:
			device_printf(rb->fc->bdev, "%s: "
			    "unexpected flag 0x%02x\n", __func__,
			    rb->xfer->flag);
		}
		return;
	case FWTCODE_WREQQ:
	case FWTCODE_WREQB:
	case FWTCODE_RREQQ:
	case FWTCODE_RREQB:
	case FWTCODE_LREQ:
		bind = fw_bindlookup(rb->fc, fp->mode.rreqq.dest_hi,
		    fp->mode.rreqq.dest_lo);
		if (bind == NULL) {
			device_printf(rb->fc->bdev, "%s: "
			    "Unknown service addr 0x%04x:0x%08x %s(%x)"
			    " src=0x%x data=%x\n",
			    __func__,
			    fp->mode.wreqq.dest_hi,
			    fp->mode.wreqq.dest_lo,
			    tcode_str[tcode], tcode,
			    fp->mode.hdr.src,
			    ntohl(fp->mode.wreqq.data));

			if (rb->fc->status == FWBUSINIT) {
				device_printf(rb->fc->bdev,
				    "%s: cannot respond(bus reset)!\n",
				    __func__);
				return;
			}
			rb->xfer = fw_xfer_alloc(M_FWXFER);
			if (rb->xfer == NULL) {
				return;
			}
			rb->xfer->send.spd = rb->spd;
			rb->xfer->send.pay_len = 0;
			resfp = &rb->xfer->send.hdr;
			switch (tcode) {
			case FWTCODE_WREQQ:
			case FWTCODE_WREQB:
				resfp->mode.hdr.tcode = FWTCODE_WRES;
				break;
			case FWTCODE_RREQQ:
				resfp->mode.hdr.tcode = FWTCODE_RRESQ;
				break;
			case FWTCODE_RREQB:
				resfp->mode.hdr.tcode = FWTCODE_RRESB;
				break;
			case FWTCODE_LREQ:
				resfp->mode.hdr.tcode = FWTCODE_LRES;
				break;
			}
			resfp->mode.hdr.dst = fp->mode.hdr.src;
			resfp->mode.hdr.tlrt = fp->mode.hdr.tlrt;
			resfp->mode.hdr.pri = fp->mode.hdr.pri;
			resfp->mode.rresb.rtcode = RESP_ADDRESS_ERROR;
			resfp->mode.rresb.extcode = 0;
			resfp->mode.rresb.len = 0;
/*
			rb->xfer->hand = fw_xferwake;
*/
			rb->xfer->hand = fw_xfer_free;
			if (fw_asyreq(rb->fc, -1, rb->xfer))
				fw_xfer_free(rb->xfer);
			return;
		}
		len = 0;
		for (i = 0; i < rb->nvec; i++)
			len += rb->vec[i].iov_len;
		rb->xfer = STAILQ_FIRST(&bind->xferlist);
		if (rb->xfer == NULL) {
			device_printf(rb->fc->bdev, "%s: "
			    "Discard a packet for this bind.\n", __func__);
			return;
		}
		STAILQ_REMOVE_HEAD(&bind->xferlist, link);
		fw_rcv_copy(rb);
		rb->xfer->hand(rb->xfer);
		return;
#if 0 /* shouldn't happen ?? or for GASP */
	case FWTCODE_STREAM:
	{
		struct fw_xferq *xferq;

		xferq = rb->fc->ir[sub];
#if 0
		printf("stream rcv dma %d len %d off %d spd %d\n",
			sub, len, off, spd);
#endif
		if (xferq->queued >= xferq->maxq) {
			printf("receive queue is full\n");
			return;
		}
		/* XXX get xfer from xfer queue, we don't need copy for
			per packet mode */
		rb->xfer = fw_xfer_alloc_buf(M_FWXFER, 0, /* XXX */
						vec[0].iov_len);
		if (rb->xfer == NULL)
			return;
		fw_rcv_copy(rb)
		s = splfw();
		xferq->queued++;
		STAILQ_INSERT_TAIL(&xferq->q, rb->xfer, link);
		splx(s);
		sc = device_get_softc(rb->fc->bdev);
		if (SEL_WAITING(&xferq->rsel))
			selwakeuppri(&xferq->rsel, FWPRI);
		if (xferq->flag & FWXFERQ_WAKEUP) {
			xferq->flag &= ~FWXFERQ_WAKEUP;
			wakeup((caddr_t)xferq);
		}
		if (xferq->flag & FWXFERQ_HANDLER) {
			xferq->hand(xferq);
		}
		return;
		break;
	}
#endif
	default:
		device_printf(rb->fc->bdev,"%s: unknown tcode %d\n",
		    __func__, tcode);
		break;
	}
}

/*
 * Post process for Bus Manager election process.
 */
static void
fw_try_bmr_callback(struct fw_xfer *xfer)
{
	struct firewire_comm *fc;
	int bmr;

	if (xfer == NULL)
		return;
	fc = xfer->fc;
	if (xfer->resp != 0)
		goto error;
	if (xfer->recv.payload == NULL)
		goto error;
	if (xfer->recv.hdr.mode.lres.rtcode != FWRCODE_COMPLETE)
		goto error;

	bmr = ntohl(xfer->recv.payload[0]);
	if (bmr == 0x3f)
		bmr = fc->nodeid;

	CSRARC(fc, BUS_MGR_ID) = fc->set_bmr(fc, bmr & 0x3f);
	fw_xfer_free_buf(xfer);
	fw_bmr(fc);
	return;

error:
	device_printf(fc->bdev, "bus manager election failed\n");
	fw_xfer_free_buf(xfer);
}


/*
 * To candidate Bus Manager election process.
 */
static void
fw_try_bmr(void *arg)
{
	struct fw_xfer *xfer;
	struct firewire_comm *fc = arg;
	struct fw_pkt *fp;
	int err = 0;

	xfer = fw_xfer_alloc_buf(M_FWXFER, 8, 4);
	if (xfer == NULL)
		return;
	xfer->send.spd = 0;
	fc->status = FWBUSMGRELECT;

	fp = &xfer->send.hdr;
	fp->mode.lreq.dest_hi = 0xffff;
	fp->mode.lreq.tlrt = 0;
	fp->mode.lreq.tcode = FWTCODE_LREQ;
	fp->mode.lreq.pri = 0;
	fp->mode.lreq.src = 0;
	fp->mode.lreq.len = 8;
	fp->mode.lreq.extcode = EXTCODE_CMP_SWAP;
	fp->mode.lreq.dst = FWLOCALBUS | fc->irm;
	fp->mode.lreq.dest_lo = 0xf0000000 | BUS_MGR_ID;
	xfer->send.payload[0] = htonl(0x3f);
	xfer->send.payload[1] = htonl(fc->nodeid);
	xfer->hand = fw_try_bmr_callback;

	err = fw_asyreq(fc, -1, xfer);
	if (err) {
		fw_xfer_free_buf(xfer);
		return;
	}
	return;
}

#ifdef FW_VMACCESS
/*
 * Software implementation for physical memory block access.
 * XXX:Too slow, useful for debug purpose only.
 */
static void
fw_vmaccess(struct fw_xfer *xfer)
{
	struct fw_pkt *rfp, *sfp = NULL;
	uint32_t *ld = (uint32_t *)xfer->recv.buf;

	printf("vmaccess spd:%2x len:%03x data:%08x %08x %08x %08x\n",
	    xfer->spd, xfer->recv.len, ntohl(ld[0]), ntohl(ld[1]), ntohl(ld[2]),
	    ntohl(ld[3]));
	printf("vmaccess          data:%08x %08x %08x %08x\n", ntohl(ld[4]),
	    ntohl(ld[5]), ntohl(ld[6]), ntohl(ld[7]));
	if (xfer->resp != 0) {
		fw_xfer_free(xfer);
		return;
	}
	if (xfer->recv.buf == NULL) {
		fw_xfer_free(xfer);
		return;
	}
	rfp = (struct fw_pkt *)xfer->recv.buf;
	switch (rfp->mode.hdr.tcode) {
		/* XXX need fix for 64bit arch */
		case FWTCODE_WREQB:
			xfer->send.buf = malloc(12, M_FW, M_NOWAIT);
			xfer->send.len = 12;
			sfp = (struct fw_pkt *)xfer->send.buf;
			bcopy(rfp->mode.wreqb.payload,
			    (caddr_t)ntohl(rfp->mode.wreqb.dest_lo),s
			    ntohs(rfp->mode.wreqb.len));
			sfp->mode.wres.tcode = FWTCODE_WRES;
			sfp->mode.wres.rtcode = 0;
			break;
		case FWTCODE_WREQQ:
			xfer->send.buf = malloc(12, M_FW, M_NOWAIT);
			xfer->send.len = 12;
			sfp->mode.wres.tcode = FWTCODE_WRES;
			*((uint32_t *)(ntohl(rfp->mode.wreqb.dest_lo))) =
			    rfp->mode.wreqq.data;
			sfp->mode.wres.rtcode = 0;
			break;
		case FWTCODE_RREQB:
			xfer->send.buf = malloc(16 + rfp->mode.rreqb.len,
			    M_FW, M_NOWAIT);
			xfer->send.len = 16 + ntohs(rfp->mode.rreqb.len);
			sfp = (struct fw_pkt *)xfer->send.buf;
			bcopy((caddr_t)ntohl(rfp->mode.rreqb.dest_lo),
			    sfp->mode.rresb.payload,
			    ntohs(rfp->mode.rreqb.len));
			sfp->mode.rresb.tcode = FWTCODE_RRESB;
			sfp->mode.rresb.len = rfp->mode.rreqb.len;
			sfp->mode.rresb.rtcode = 0;
			sfp->mode.rresb.extcode = 0;
			break;
		case FWTCODE_RREQQ:
			xfer->send.buf = malloc(16, M_FW, M_NOWAIT);
			xfer->send.len = 16;
			sfp = (struct fw_pkt *)xfer->send.buf;
			sfp->mode.rresq.data =
			    *(uint32_t *)(ntohl(rfp->mode.rreqq.dest_lo));
			sfp->mode.wres.tcode = FWTCODE_RRESQ;
			sfp->mode.rresb.rtcode = 0;
			break;
		default:
			fw_xfer_free(xfer);
			return;
	}
	sfp->mode.hdr.dst = rfp->mode.hdr.src;
	xfer->dst = ntohs(rfp->mode.hdr.src);
	xfer->hand = fw_xfer_free;

	sfp->mode.hdr.tlrt = rfp->mode.hdr.tlrt;
	sfp->mode.hdr.pri = 0;

	fw_asyreq(xfer->fc, -1, xfer);
/**/
	return;
}
#endif

/*
 * CRC16 check-sum for IEEE1394 register blocks.
 */
uint16_t
fw_crc16(uint32_t *ptr, uint32_t len)
{
	uint32_t i, sum, crc = 0;
	int shift;
	len = (len + 3) & ~3;
	for (i = 0; i < len; i += 4) {
		for (shift = 28; shift >= 0; shift -= 4) {
			sum = ((crc >> 12) ^ (ptr[i/4] >> shift)) & 0xf;
			crc = (crc << 4) ^ (sum << 12) ^ (sum << 5) ^ sum;
		}
		crc &= 0xffff;
	}
	return ((uint16_t) crc);
}

/*
 * Find the root node, if it is not
 * Cycle Master Capable, then we should
 * override this and become the Cycle
 * Master
 */
static int
fw_bmr(struct firewire_comm *fc)
{
	struct fw_device fwdev;
	union fw_self_id *self_id;
	int cmstr;
	uint32_t quad;

	/* Check to see if the current root node is cycle master capable */
	self_id = fw_find_self_id(fc, fc->max_node);
	if (fc->max_node > 0) {
		/* XXX check cmc bit of businfo block rather than contender */
		if (self_id->p0.link_active && self_id->p0.contender)
			cmstr = fc->max_node;
		else {
			device_printf(fc->bdev,
			    "root node is not cycle master capable\n");
			/* XXX shall we be the cycle master? */
			cmstr = fc->nodeid;
			/* XXX need bus reset */
		}
	} else
		cmstr = -1;

	device_printf(fc->bdev, "bus manager %d %s\n",
		CSRARC(fc, BUS_MGR_ID),
		(CSRARC(fc, BUS_MGR_ID) != fc->nodeid) ? "(me)" : "");
	if (CSRARC(fc, BUS_MGR_ID) != fc->nodeid) {
		/* We are not the bus manager */
		return (0);
	}

	/* Optimize gapcount */
	if (fc->max_hop <= MAX_GAPHOP)
		fw_phy_config(fc, cmstr, gap_cnt[fc->max_hop]);
	/* If we are the cycle master, nothing to do */
	if (cmstr == fc->nodeid || cmstr == -1)
		return 0;
	/* Bus probe has not finished, make dummy fwdev for cmstr */
	bzero(&fwdev, sizeof(fwdev));
	fwdev.fc = fc;
	fwdev.dst = cmstr;
	fwdev.speed = 0;
	fwdev.maxrec = 8; /* 512 */
	fwdev.status = FWDEVINIT;
	/* Set cmstr bit on the cycle master */
	quad = htonl(1 << 8);
	fwmem_write_quad(&fwdev, NULL, 0/*spd*/,
	    0xffff, 0xf0000000 | STATE_SET, &quad, fw_asy_callback_free);

	return 0;
}

int
fw_open_isodma(struct firewire_comm *fc, int tx)
{
	struct fw_xferq **xferqa;
	struct fw_xferq *xferq;
	int i;

	if (tx)
		xferqa = &fc->it[0];
	else
		xferqa = &fc->ir[0];

	FW_GLOCK(fc);
	for (i = 0; i < fc->nisodma; i++) {
		xferq = xferqa[i];
		if ((xferq->flag & FWXFERQ_OPEN) == 0) {
			xferq->flag |= FWXFERQ_OPEN;
			break;
		}
	}
	if (i == fc->nisodma) {
		printf("no free dma channel (tx=%d)\n", tx);
		i = -1;
	}
	FW_GUNLOCK(fc);
	return (i);
}

static int
fw_modevent(module_t mode, int type, void *data)
{
	int err = 0;
	static eventhandler_tag fwdev_ehtag = NULL;

	switch (type) {
	case MOD_LOAD:
		fwdev_ehtag = EVENTHANDLER_REGISTER(dev_clone,
		    fwdev_clone, 0, 1000);
		break;
	case MOD_UNLOAD:
		if (fwdev_ehtag != NULL)
			EVENTHANDLER_DEREGISTER(dev_clone, fwdev_ehtag);
		break;
	case MOD_SHUTDOWN:
		break;
	default:
		return (EOPNOTSUPP);
	}
	return (err);
}


DRIVER_MODULE(firewire, fwohci, firewire_driver, firewire_devclass,
    fw_modevent,0);
MODULE_VERSION(firewire, 1);