freebsd-dev/sys/dev/sound/pcm/sound.c

/*-
 * Copyright (c) 1999 Cameron Grant <cg@freebsd.org>
 * (C) 1997 Luigi Rizzo (luigi@iet.unipi.it)
 * 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.
 */

#include <dev/sound/pcm/sound.h>
#include <dev/sound/pcm/vchan.h>
#include <dev/sound/pcm/dsp.h>
#include <sys/limits.h>
#include <sys/sysctl.h>

#include "feeder_if.h"

SND_DECLARE_FILE("$FreeBSD$");

devclass_t pcm_devclass;

int pcm_veto_load = 1;

#ifdef USING_DEVFS
int snd_unit = 0;
TUNABLE_INT("hw.snd.default_unit", &snd_unit);
#endif

int snd_maxautovchans = 4;
/* XXX: a tunable implies that we may need more than one sound channel before
   the system can change a sysctl (/etc/sysctl.conf), do we really need
   this? */
TUNABLE_INT("hw.snd.maxautovchans", &snd_maxautovchans);

SYSCTL_NODE(_hw, OID_AUTO, snd, CTLFLAG_RD, 0, "Sound driver");

/**
 * @brief Unit number allocator for syncgroup IDs
 */
struct unrhdr *pcmsg_unrhdr = NULL;

static int sndstat_prepare_pcm(struct sbuf *s, device_t dev, int verbose);

struct sysctl_ctx_list *
snd_sysctl_tree(device_t dev)
{
	struct snddev_info *d = device_get_softc(dev);

	return &d->sysctl_tree;
}

struct sysctl_oid *
snd_sysctl_tree_top(device_t dev)
{
	struct snddev_info *d = device_get_softc(dev);

	return d->sysctl_tree_top;
}

void *
snd_mtxcreate(const char *desc, const char *type)
{
#ifdef USING_MUTEX
	struct mtx *m;

	m = malloc(sizeof(*m), M_DEVBUF, M_WAITOK | M_ZERO);
	if (m == NULL)
		return NULL;
	mtx_init(m, desc, type, MTX_DEF);
	return m;
#else
	return (void *)0xcafebabe;
#endif
}

void
snd_mtxfree(void *m)
{
#ifdef USING_MUTEX
	struct mtx *mtx = m;

	/* mtx_assert(mtx, MA_OWNED); */
	mtx_destroy(mtx);
	free(mtx, M_DEVBUF);
#endif
}

void
snd_mtxassert(void *m)
{
#ifdef USING_MUTEX
#ifdef INVARIANTS
	struct mtx *mtx = m;

	mtx_assert(mtx, MA_OWNED);
#endif
#endif
}
/*
void
snd_mtxlock(void *m)
{
#ifdef USING_MUTEX
	struct mtx *mtx = m;

	mtx_lock(mtx);
#endif
}

void
snd_mtxunlock(void *m)
{
#ifdef USING_MUTEX
	struct mtx *mtx = m;

	mtx_unlock(mtx);
#endif
}
*/
int
snd_setup_intr(device_t dev, struct resource *res, int flags, driver_intr_t hand, void *param, void **cookiep)
{
#ifdef USING_MUTEX
	flags &= INTR_MPSAFE;
	flags |= INTR_TYPE_AV;
#else
	flags = INTR_TYPE_AV;
#endif
	return bus_setup_intr(dev, res, flags, hand, param, cookiep);
}

#ifndef	PCM_DEBUG_MTX
void
pcm_lock(struct snddev_info *d)
{
	snd_mtxlock(d->lock);
}

void
pcm_unlock(struct snddev_info *d)
{
	snd_mtxunlock(d->lock);
}
#endif

struct pcm_channel *
pcm_getfakechan(struct snddev_info *d)
{
	return d->fakechan;
}

static int
pcm_setvchans(struct snddev_info *d, int newcnt)
{
	struct snddev_channel *sce = NULL;
	struct pcm_channel *c = NULL;
	int err = 0, vcnt, dcnt, i;

	pcm_inprog(d, 1);
		
	if (!(d->flags & SD_F_AUTOVCHAN)) {
		err = EINVAL;
		goto setvchans_out;
	}

	vcnt = d->vchancount;
	dcnt = d->playcount + d->reccount;

	if (newcnt < 0 || (dcnt + newcnt) > (PCMMAXCHAN + 1)) {
		err = E2BIG;
		goto setvchans_out;
	}

	dcnt += vcnt;

	if (newcnt > vcnt) {
		/* add new vchans - find a parent channel first */
		SLIST_FOREACH(sce, &d->channels, link) {
			c = sce->channel;
			CHN_LOCK(c);
			if (c->direction == PCMDIR_PLAY &&
					((c->flags & CHN_F_HAS_VCHAN) ||
					(vcnt == 0 &&
					!(c->flags & (CHN_F_BUSY | CHN_F_VIRTUAL)))))
				goto addok;
			CHN_UNLOCK(c);
		}
		err = EBUSY;
		goto setvchans_out;
addok:
		c->flags |= CHN_F_BUSY;
		while (err == 0 && newcnt > vcnt) {
			if (dcnt > PCMMAXCHAN) {
				device_printf(d->dev, "%s: Maximum channel reached.\n", __func__);
				break;
			}
			err = vchan_create(c);
			if (err == 0) {
				vcnt++;
				dcnt++;
			} else if (err == E2BIG && newcnt > vcnt)
				device_printf(d->dev, "%s: err=%d Maximum channel reached.\n", __func__, err);
		}
		if (vcnt == 0)
			c->flags &= ~CHN_F_BUSY;
		CHN_UNLOCK(c);
	} else if (newcnt < vcnt) {
#define ORPHAN_CDEVT(cdevt) \
	((cdevt) == NULL || ((cdevt)->si_drv1 == NULL && \
	(cdevt)->si_drv2 == NULL))
		while (err == 0 && newcnt < vcnt) {
			i = 0;
			SLIST_FOREACH(sce, &d->channels, link) {
				c = sce->channel;
				CHN_LOCK(c);
				if (c->direction == PCMDIR_PLAY &&
						(c->flags & CHN_F_VIRTUAL) &&
						(i++ == newcnt)) {
					if (!(c->flags & CHN_F_BUSY) &&
							ORPHAN_CDEVT(sce->dsp_devt) &&
							ORPHAN_CDEVT(sce->dspW_devt) &&
							ORPHAN_CDEVT(sce->audio_devt) &&
							ORPHAN_CDEVT(sce->dspr_devt))
						goto remok;
					/*
					 * Either we're busy, or our cdev
					 * has been stolen by dsp_clone().
					 * Skip, and increase newcnt.
					 */
					if (!(c->flags & CHN_F_BUSY))
						device_printf(d->dev,
							"%s: <%s> somebody steal my cdev!\n",
							__func__, c->name);
					newcnt++;
				}
				CHN_UNLOCK(c);
			}
			if (vcnt != newcnt)
				err = EBUSY;
			break;
remok:
			CHN_UNLOCK(c);
			err = vchan_destroy(c);
			if (err == 0)
				vcnt--;
			else
				device_printf(d->dev,
					"%s: WARNING: vchan_destroy() failed!",
					__func__);
		}
	}

setvchans_out:
	pcm_inprog(d, -1);
	return err;
}

/* return error status and a locked channel */
int
pcm_chnalloc(struct snddev_info *d, struct pcm_channel **ch, int direction,
		pid_t pid, int chnum)
{
	struct pcm_channel *c;
	struct snddev_channel *sce;
	int err;

retry_chnalloc:
	err = ENODEV;
	/* scan for a free channel */
	SLIST_FOREACH(sce, &d->channels, link) {
		c = sce->channel;
		CHN_LOCK(c);
		if (c->direction == direction && !(c->flags & CHN_F_BUSY)) {
			if (chnum < 0 || sce->chan_num == chnum) {
				c->flags |= CHN_F_BUSY;
				c->pid = pid;
				*ch = c;
				return 0;
			}
		}
		if (sce->chan_num == chnum) {
			if (c->direction != direction)
				err = EOPNOTSUPP;
			else if (c->flags & CHN_F_BUSY)
				err = EBUSY;
			else
				err = EINVAL;
			CHN_UNLOCK(c);
			return err;
		} else if (c->direction == direction && (c->flags & CHN_F_BUSY))
			err = EBUSY;
		CHN_UNLOCK(c);
	}

	/* no channel available */
	if (chnum == -1 && direction == PCMDIR_PLAY && d->vchancount > 0 &&
			d->vchancount < snd_maxautovchans &&
			d->devcount <= PCMMAXCHAN) {
		err = pcm_setvchans(d, d->vchancount + 1);
		if (err == 0) {
			chnum = -2;
			goto retry_chnalloc;
		}
	}

	return err;
}

/* release a locked channel and unlock it */
int
pcm_chnrelease(struct pcm_channel *c)
{
	CHN_LOCKASSERT(c);
	c->flags &= ~CHN_F_BUSY;
	c->pid = -1;
	CHN_UNLOCK(c);
	return 0;
}

int
pcm_chnref(struct pcm_channel *c, int ref)
{
	int r;

	CHN_LOCKASSERT(c);
	c->refcount += ref;
	r = c->refcount;
	return r;
}

int
pcm_inprog(struct snddev_info *d, int delta)
{
	int r;

	if (delta == 0)
		return d->inprog;

	/* backtrace(); */
	pcm_lock(d);
	d->inprog += delta;
	r = d->inprog;
	pcm_unlock(d);
	return r;
}

static void
pcm_setmaxautovchans(struct snddev_info *d, int num)
{
	if (num > 0 && d->vchancount == 0)
		pcm_setvchans(d, 1);
	else if (num == 0 && d->vchancount > 0)
		pcm_setvchans(d, 0);
}

#ifdef USING_DEVFS
static int
sysctl_hw_snd_default_unit(SYSCTL_HANDLER_ARGS)
{
	struct snddev_info *d;
	int error, unit;

	unit = snd_unit;
	error = sysctl_handle_int(oidp, &unit, sizeof(unit), req);
	if (error == 0 && req->newptr != NULL) {
		if (unit < 0 || unit >= devclass_get_maxunit(pcm_devclass))
			return EINVAL;
		d = devclass_get_softc(pcm_devclass, unit);
		if (d == NULL || SLIST_EMPTY(&d->channels))
			return EINVAL;
		snd_unit = unit;
	}
	return (error);
}
/* XXX: do we need a way to let the user change the default unit? */
SYSCTL_PROC(_hw_snd, OID_AUTO, default_unit, CTLTYPE_INT | CTLFLAG_RW,
            0, sizeof(int), sysctl_hw_snd_default_unit, "I", "");
#endif

static int
sysctl_hw_snd_maxautovchans(SYSCTL_HANDLER_ARGS)
{
	struct snddev_info *d;
	int i, v, error;

	v = snd_maxautovchans;
	error = sysctl_handle_int(oidp, &v, sizeof(v), req);
	if (error == 0 && req->newptr != NULL) {
		if (v < 0 || v > PCMMAXCHAN)
			return E2BIG;
		if (pcm_devclass != NULL && v != snd_maxautovchans) {
			for (i = 0; i < devclass_get_maxunit(pcm_devclass); i++) {
				d = devclass_get_softc(pcm_devclass, i);
				if (!d)
					continue;
				pcm_setmaxautovchans(d, v);
			}
		}
		snd_maxautovchans = v;
	}
	return (error);
}
SYSCTL_PROC(_hw_snd, OID_AUTO, maxautovchans, CTLTYPE_INT | CTLFLAG_RW,
            0, sizeof(int), sysctl_hw_snd_maxautovchans, "I", "");

struct pcm_channel *
pcm_chn_create(struct snddev_info *d, struct pcm_channel *parent, kobj_class_t cls, int dir, void *devinfo)
{
	struct snddev_channel *sce;
	struct pcm_channel *ch, *c;
	char *dirs;
	uint32_t flsearch = 0;
	int direction, err, rpnum, *pnum;

	switch(dir) {
	case PCMDIR_PLAY:
		dirs = "play";
		direction = PCMDIR_PLAY;
		pnum = &d->playcount;
		break;

	case PCMDIR_REC:
		dirs = "record";
		direction = PCMDIR_REC;
		pnum = &d->reccount;
		break;

	case PCMDIR_VIRTUAL:
		dirs = "virtual";
		direction = PCMDIR_PLAY;
		pnum = &d->vchancount;
		flsearch = CHN_F_VIRTUAL;
		break;

	default:
		return NULL;
	}

	ch = malloc(sizeof(*ch), M_DEVBUF, M_WAITOK | M_ZERO);
	if (!ch)
		return NULL;

	ch->methods = kobj_create(cls, M_DEVBUF, M_WAITOK);
	if (!ch->methods) {
		free(ch, M_DEVBUF);

		return NULL;
	}

	snd_mtxlock(d->lock);
	ch->num = 0;
	rpnum = 0;
	SLIST_FOREACH(sce, &d->channels, link) {
		c = sce->channel;
		if (direction != c->direction ||
				(c->flags & CHN_F_VIRTUAL) != flsearch)
			continue;
		if (ch->num == c->num)
			ch->num++;
		else {
#if 0
			device_printf(d->dev,
				"%s: %s channel numbering screwed (Expect: %d, Got: %d)\n",
				__func__, dirs, ch->num, c->num);
#endif
			goto retry_num_search;
		}
		rpnum++;
	}
	goto retry_num_search_out;
retry_num_search:
	rpnum = 0;
	SLIST_FOREACH(sce, &d->channels, link) {
		c = sce->channel;
		if (direction != c->direction ||
				(c->flags & CHN_F_VIRTUAL) != flsearch)
			continue;
		if (ch->num == c->num) {
			ch->num++;
			goto retry_num_search;
		}
		rpnum++;
	}
retry_num_search_out:
	if (*pnum != rpnum) {
		device_printf(d->dev,
			"%s: WARNING: pnum screwed : dirs=%s, pnum=%d, rpnum=%d\n",
			__func__, dirs, *pnum, rpnum);
		*pnum = rpnum;
	}
	(*pnum)++;
	snd_mtxunlock(d->lock);

	ch->pid = -1;
	ch->parentsnddev = d;
	ch->parentchannel = parent;
	ch->dev = d->dev;
	snprintf(ch->name, CHN_NAMELEN, "%s:%s:%d", device_get_nameunit(ch->dev), dirs, ch->num);

	err = chn_init(ch, devinfo, dir, direction);
	if (err) {
		device_printf(d->dev, "chn_init(%s) failed: err = %d\n", ch->name, err);
		kobj_delete(ch->methods, M_DEVBUF);
		free(ch, M_DEVBUF);
		snd_mtxlock(d->lock);
		(*pnum)--;
		snd_mtxunlock(d->lock);

		return NULL;
	}

	return ch;
}

int
pcm_chn_destroy(struct pcm_channel *ch)
{
	struct snddev_info *d;
	int err;

	d = ch->parentsnddev;
	err = chn_kill(ch);
	if (err) {
		device_printf(d->dev, "chn_kill(%s) failed, err = %d\n", ch->name, err);
		return err;
	}

	kobj_delete(ch->methods, M_DEVBUF);
	free(ch, M_DEVBUF);

	return 0;
}

int
pcm_chn_add(struct snddev_info *d, struct pcm_channel *ch)
{
	struct snddev_channel *sce, *tmp, *after;
	unsigned rdevcount;
	int device = device_get_unit(d->dev);
	size_t namelen;

	/*
	 * Note it's confusing nomenclature.
	 * dev_t
	 * device -> pcm_device
	 * unit -> pcm_channel
	 * channel -> snddev_channel
	 * device_t
	 * unit -> pcm_device
	 */

	sce = malloc(sizeof(*sce), M_DEVBUF, M_WAITOK | M_ZERO);
	if (!sce) {
		return ENOMEM;
	}

	snd_mtxlock(d->lock);
	sce->channel = ch;
	sce->chan_num = 0;
	rdevcount = 0;
	after = NULL;
	SLIST_FOREACH(tmp, &d->channels, link) {
		if (sce->chan_num == tmp->chan_num)
			sce->chan_num++;
		else {
#if 0
			device_printf(d->dev,
				"%s: cdev numbering screwed (Expect: %d, Got: %d)\n",
				__func__, sce->chan_num, tmp->chan_num);
#endif
			goto retry_chan_num_search;
		}
		after = tmp;
		rdevcount++;
	}
	goto retry_chan_num_search_out;
retry_chan_num_search:
	/*
	 * Look for possible channel numbering collision. This may not
	 * be optimized, but it will ensure that no collision occured.
	 * Can be considered cheap since none of the locking/unlocking
	 * operations involved.
	 */
	rdevcount = 0;
	after = NULL;
	SLIST_FOREACH(tmp, &d->channels, link) {
		if (sce->chan_num == tmp->chan_num) {
			sce->chan_num++;
			goto retry_chan_num_search;
		}
		if (sce->chan_num > tmp->chan_num)
			after = tmp;
		rdevcount++;
	}
retry_chan_num_search_out:
	/*
	 * Don't overflow PCMMKMINOR / PCMMAXCHAN.
	 */
	if (sce->chan_num > PCMMAXCHAN) {
		snd_mtxunlock(d->lock);
		device_printf(d->dev,
			"%s: WARNING: sce->chan_num overflow! (%d)\n",
			__func__, sce->chan_num);
		free(sce, M_DEVBUF);
		return E2BIG;
	}
	if (d->devcount != rdevcount) {
		device_printf(d->dev,
			"%s: WARNING: devcount screwed! d->devcount=%u, rdevcount=%u\n",
			__func__, d->devcount, rdevcount);
		d->devcount = rdevcount;
	}
	d->devcount++;
	if (after == NULL) {
		SLIST_INSERT_HEAD(&d->channels, sce, link);
	} else {
		SLIST_INSERT_AFTER(after, sce, link);
	}
#if 0
	if (1) {
		int cnum = 0;
		SLIST_FOREACH(tmp, &d->channels, link) {
			if (cnum != tmp->chan_num)
				device_printf(d->dev,
					"%s: WARNING: inconsistent cdev numbering! (Expect: %d, Got: %d)\n",
					__func__, cnum, tmp->chan_num);
			cnum++;
		}
	}
#endif

	namelen = strlen(ch->name);
	if ((CHN_NAMELEN - namelen) > 10) {	/* ":dspXX.YYY" */
		snprintf(ch->name + namelen,
			CHN_NAMELEN - namelen, ":dsp%d.%d",
			device, sce->chan_num);
	}
	snd_mtxunlock(d->lock);

	/*
	 * I will revisit these someday, and nuke it mercilessly..
	 */
	sce->dsp_devt = make_dev(&dsp_cdevsw,
			PCMMKMINOR(device, SND_DEV_DSP, sce->chan_num),
			UID_ROOT, GID_WHEEL, 0666, "dsp%d.%d",
			device, sce->chan_num);

	sce->dspW_devt = make_dev(&dsp_cdevsw,
			PCMMKMINOR(device, SND_DEV_DSP16, sce->chan_num),
			UID_ROOT, GID_WHEEL, 0666, "dspW%d.%d",
			device, sce->chan_num);

	sce->audio_devt = make_dev(&dsp_cdevsw,
			PCMMKMINOR(device, SND_DEV_AUDIO, sce->chan_num),
			UID_ROOT, GID_WHEEL, 0666, "audio%d.%d",
			device, sce->chan_num);

	if (ch->direction == PCMDIR_REC)
		sce->dspr_devt = make_dev(&dsp_cdevsw,
				PCMMKMINOR(device, SND_DEV_DSPREC,
					sce->chan_num), UID_ROOT, GID_WHEEL,
				0666, "dspr%d.%d", device, sce->chan_num);

	return 0;
}

int
pcm_chn_remove(struct snddev_info *d, struct pcm_channel *ch)
{
	struct snddev_channel *sce;
#if 0
	int ourlock;

	ourlock = 0;
	if (!mtx_owned(d->lock)) {
		snd_mtxlock(d->lock);
		ourlock = 1;
	}
#endif

	SLIST_FOREACH(sce, &d->channels, link) {
		if (sce->channel == ch)
			goto gotit;
	}
#if 0
	if (ourlock)
		snd_mtxunlock(d->lock);
#endif
	return EINVAL;
gotit:
	SLIST_REMOVE(&d->channels, sce, snddev_channel, link);

	if (ch->flags & CHN_F_VIRTUAL)
		d->vchancount--;
	else if (ch->direction == PCMDIR_REC)
		d->reccount--;
	else
		d->playcount--;

#if 0
	if (ourlock)
		snd_mtxunlock(d->lock);
#endif
	free(sce, M_DEVBUF);

	return 0;
}

int
pcm_addchan(device_t dev, int dir, kobj_class_t cls, void *devinfo)
{
	struct snddev_info *d = device_get_softc(dev);
	struct pcm_channel *ch;
	int err;

	ch = pcm_chn_create(d, NULL, cls, dir, devinfo);
	if (!ch) {
		device_printf(d->dev, "pcm_chn_create(%s, %d, %p) failed\n", cls->name, dir, devinfo);
		return ENODEV;
	}

	err = pcm_chn_add(d, ch);
	if (err) {
		device_printf(d->dev, "pcm_chn_add(%s) failed, err=%d\n", ch->name, err);
		pcm_chn_destroy(ch);
		return err;
	}

	return err;
}

static int
pcm_killchan(device_t dev)
{
	struct snddev_info *d = device_get_softc(dev);
	struct snddev_channel *sce;
	struct pcm_channel *ch;
	int error = 0;

	sce = SLIST_FIRST(&d->channels);
	ch = sce->channel;

	error = pcm_chn_remove(d, sce->channel);
	if (error)
		return (error);
	return (pcm_chn_destroy(ch));
}

int
pcm_setstatus(device_t dev, char *str)
{
	struct snddev_info *d = device_get_softc(dev);

	snd_mtxlock(d->lock);
	strncpy(d->status, str, SND_STATUSLEN);
	snd_mtxunlock(d->lock);
	if (snd_maxautovchans > 0)
		pcm_setvchans(d, 1);
	return 0;
}

uint32_t
pcm_getflags(device_t dev)
{
	struct snddev_info *d = device_get_softc(dev);

	return d->flags;
}

void
pcm_setflags(device_t dev, uint32_t val)
{
	struct snddev_info *d = device_get_softc(dev);

	d->flags = val;
}

void *
pcm_getdevinfo(device_t dev)
{
	struct snddev_info *d = device_get_softc(dev);

	return d->devinfo;
}

unsigned int
pcm_getbuffersize(device_t dev, unsigned int minbufsz, unsigned int deflt, unsigned int maxbufsz)
{
	struct snddev_info *d = device_get_softc(dev);
	int sz, x;

	sz = 0;
	if (resource_int_value(device_get_name(dev), device_get_unit(dev), "buffersize", &sz) == 0) {
		x = sz;
		RANGE(sz, minbufsz, maxbufsz);
		if (x != sz)
			device_printf(dev, "'buffersize=%d' hint is out of range (%d-%d), using %d\n", x, minbufsz, maxbufsz, sz);
		x = minbufsz;
		while (x < sz)
			x <<= 1;
		if (x > sz)
			x >>= 1;
		if (x != sz) {
			device_printf(dev, "'buffersize=%d' hint is not a power of 2, using %d\n", sz, x);
			sz = x;
		}
	} else {
		sz = deflt;
	}

	d->bufsz = sz;

	return sz;
}

int
pcm_register(device_t dev, void *devinfo, int numplay, int numrec)
{
	struct snddev_info *d = device_get_softc(dev);

	if (pcm_veto_load) {
		device_printf(dev, "disabled due to an error while initialising: %d\n", pcm_veto_load);

		return EINVAL;
	}

	d->lock = snd_mtxcreate(device_get_nameunit(dev), "sound cdev");

#if 0
	/*
	 * d->flags should be cleared by the allocator of the softc.
	 * We cannot clear this field here because several devices set
	 * this flag before calling pcm_register().
	 */
	d->flags = 0;
#endif
	d->dev = dev;
	d->devinfo = devinfo;
	d->devcount = 0;
	d->reccount = 0;
	d->playcount = 0;
	d->vchancount = 0;
	d->inprog = 0;

	SLIST_INIT(&d->channels);

	if ((numplay == 0 || numrec == 0) && numplay != numrec)
		d->flags |= SD_F_SIMPLEX;

	d->fakechan = fkchan_setup(dev);
	chn_init(d->fakechan, NULL, 0, 0);

#ifdef SND_DYNSYSCTL
	sysctl_ctx_init(&d->sysctl_tree);
	d->sysctl_tree_top = SYSCTL_ADD_NODE(&d->sysctl_tree,
				 SYSCTL_STATIC_CHILDREN(_hw_snd), OID_AUTO,
				 device_get_nameunit(dev), CTLFLAG_RD, 0, "");
	if (d->sysctl_tree_top == NULL) {
		sysctl_ctx_free(&d->sysctl_tree);
		goto no;
	}
	/* XXX: an user should be able to set this with a control tool, the
	   sysadmin then needs min+max sysctls for this */
	SYSCTL_ADD_INT(snd_sysctl_tree(dev), SYSCTL_CHILDREN(snd_sysctl_tree_top(dev)),
            OID_AUTO, "_buffersize", CTLFLAG_RD, &d->bufsz, 0, "");
#endif
	if (numplay > 0) {
		d->flags |= SD_F_AUTOVCHAN;
		vchan_initsys(dev);
	}

	sndstat_register(dev, d->status, sndstat_prepare_pcm);
	return 0;
no:
	snd_mtxfree(d->lock);
	return ENXIO;
}

int
pcm_unregister(device_t dev)
{
	struct snddev_info *d = device_get_softc(dev);
	struct snddev_channel *sce;
	struct pcmchan_children *pce;
	struct pcm_channel *ch;

	if (sndstat_acquire() != 0) {
		device_printf(dev, "unregister: sndstat busy\n");
		return EBUSY;
	}

	snd_mtxlock(d->lock);
	if (d->inprog) {
		device_printf(dev, "unregister: operation in progress\n");
		snd_mtxunlock(d->lock);
		sndstat_release();
		return EBUSY;
	}

	SLIST_FOREACH(sce, &d->channels, link) {
		ch = sce->channel;
		if (ch->refcount > 0) {
			device_printf(dev, "unregister: channel %s busy (pid %d)\n", ch->name, ch->pid);
			snd_mtxunlock(d->lock);
			sndstat_release();
			return EBUSY;
		}
	}

	if (mixer_uninit(dev) == EBUSY) {
		device_printf(dev, "unregister: mixer busy\n");
		snd_mtxunlock(d->lock);
		sndstat_release();
		return EBUSY;
	}

	SLIST_FOREACH(sce, &d->channels, link) {
		if (sce->dsp_devt) {
			destroy_dev(sce->dsp_devt);
			sce->dsp_devt = NULL;
		}
		if (sce->dspW_devt) {
			destroy_dev(sce->dspW_devt);
			sce->dspW_devt = NULL;
		}
		if (sce->audio_devt) {
			destroy_dev(sce->audio_devt);
			sce->audio_devt = NULL;
		}
		if (sce->dspr_devt) {
			destroy_dev(sce->dspr_devt);
			sce->dspr_devt = NULL;
		}
		d->devcount--;
		ch = sce->channel;
		if (ch == NULL)
			continue;
		pce = SLIST_FIRST(&ch->children);
		while (pce != NULL) {
#if 0
			device_printf(d->dev, "<%s> removing <%s>\n",
				ch->name, (pce->channel != NULL) ?
					pce->channel->name : "unknown");
#endif
			SLIST_REMOVE(&ch->children, pce, pcmchan_children, link);
			free(pce, M_DEVBUF);
			pce = SLIST_FIRST(&ch->children);
		}
	}

#ifdef SND_DYNSYSCTL
	d->sysctl_tree_top = NULL;
	sysctl_ctx_free(&d->sysctl_tree);
#endif

#if 0
	SLIST_FOREACH(sce, &d->channels, link) {
		ch = sce->channel;
		if (ch == NULL)
			continue;
		if (!SLIST_EMPTY(&ch->children))
			device_printf(d->dev, "%s: WARNING: <%s> dangling child!\n",
				__func__, ch->name);
	}
#endif
	while (!SLIST_EMPTY(&d->channels))
		pcm_killchan(dev);

	chn_kill(d->fakechan);
	fkchan_kill(d->fakechan);

#if 0
	device_printf(d->dev, "%s: devcount=%u, playcount=%u, "
		"reccount=%u, vchancount=%u\n",
		__func__, d->devcount, d->playcount, d->reccount,
		d->vchancount);
#endif
	snd_mtxunlock(d->lock);
	snd_mtxfree(d->lock);
	sndstat_unregister(dev);
	sndstat_release();
	return 0;
}

/************************************************************************/

static int
sndstat_prepare_pcm(struct sbuf *s, device_t dev, int verbose)
{
	struct snddev_info *d;
	struct snddev_channel *sce;
	struct pcm_channel *c;
	struct pcm_feeder *f;
	int pc, rc, vc;

	if (verbose < 1)
		return 0;

	d = device_get_softc(dev);
	if (!d)
		return ENXIO;

	snd_mtxlock(d->lock);
	if (!SLIST_EMPTY(&d->channels)) {
		pc = rc = vc = 0;
		SLIST_FOREACH(sce, &d->channels, link) {
			c = sce->channel;
			if (c->direction == PCMDIR_PLAY) {
				if (c->flags & CHN_F_VIRTUAL)
					vc++;
				else
					pc++;
			} else
				rc++;
		}
		sbuf_printf(s, " (%dp/%dr/%dv channels%s%s)", d->playcount, d->reccount, d->vchancount,
				(d->flags & SD_F_SIMPLEX)? "" : " duplex",
#ifdef USING_DEVFS
				(device_get_unit(dev) == snd_unit)? " default" : ""
#else
				""
#endif
				);

		if (verbose <= 1) {
			snd_mtxunlock(d->lock);
			return 0;
		}

		SLIST_FOREACH(sce, &d->channels, link) {
			c = sce->channel;

			KASSERT(c->bufhard != NULL && c->bufsoft != NULL,
				("hosed pcm channel setup"));

			sbuf_printf(s, "\n\t");

			/* it would be better to indent child channels */
			sbuf_printf(s, "%s[%s]: ", c->parentchannel? c->parentchannel->name : "", c->name);
			sbuf_printf(s, "spd %d", c->speed);
			if (c->speed != sndbuf_getspd(c->bufhard))
				sbuf_printf(s, "/%d", sndbuf_getspd(c->bufhard));
			sbuf_printf(s, ", fmt 0x%08x", c->format);
			if (c->format != sndbuf_getfmt(c->bufhard))
				sbuf_printf(s, "/0x%08x", sndbuf_getfmt(c->bufhard));
			sbuf_printf(s, ", flags 0x%08x, 0x%08x", c->flags, c->feederflags);
			if (c->pid != -1)
				sbuf_printf(s, ", pid %d", c->pid);
			sbuf_printf(s, "\n\t");

			sbuf_printf(s, "interrupts %d, ", c->interrupts);
			if (c->direction == PCMDIR_REC)
				sbuf_printf(s, "overruns %d, hfree %d, sfree %d [b:%d/%d/%d|bs:%d/%d/%d]",
					c->xruns, sndbuf_getfree(c->bufhard), sndbuf_getfree(c->bufsoft),
					sndbuf_getsize(c->bufhard), sndbuf_getblksz(c->bufhard),
					sndbuf_getblkcnt(c->bufhard),
					sndbuf_getsize(c->bufsoft), sndbuf_getblksz(c->bufsoft),
					sndbuf_getblkcnt(c->bufsoft));
			else
				sbuf_printf(s, "underruns %d, ready %d [b:%d/%d/%d|bs:%d/%d/%d]",
					c->xruns, sndbuf_getready(c->bufsoft),
					sndbuf_getsize(c->bufhard), sndbuf_getblksz(c->bufhard),
					sndbuf_getblkcnt(c->bufhard),
					sndbuf_getsize(c->bufsoft), sndbuf_getblksz(c->bufsoft),
					sndbuf_getblkcnt(c->bufsoft));
			sbuf_printf(s, "\n\t");

			sbuf_printf(s, "{%s}", (c->direction == PCMDIR_REC)? "hardware" : "userland");
			sbuf_printf(s, " -> ");
			f = c->feeder;
			while (f->source != NULL)
				f = f->source;
			while (f != NULL) {
				sbuf_printf(s, "%s", f->class->name);
				if (f->desc->type == FEEDER_FMT)
					sbuf_printf(s, "(0x%08x -> 0x%08x)", f->desc->in, f->desc->out);
				if (f->desc->type == FEEDER_RATE)
					sbuf_printf(s, "(%d -> %d)", FEEDER_GET(f, FEEDRATE_SRC), FEEDER_GET(f, FEEDRATE_DST));
				if (f->desc->type == FEEDER_ROOT || f->desc->type == FEEDER_MIXER ||
						f->desc->type == FEEDER_VOLUME)
					sbuf_printf(s, "(0x%08x)", f->desc->out);
				sbuf_printf(s, " -> ");
				f = f->parent;
			}
			sbuf_printf(s, "{%s}", (c->direction == PCMDIR_REC)? "userland" : "hardware");
		}
	} else
		sbuf_printf(s, " (mixer only)");
	snd_mtxunlock(d->lock);

	return 0;
}

/************************************************************************/

#ifdef SND_DYNSYSCTL
int
sysctl_hw_snd_vchans(SYSCTL_HANDLER_ARGS)
{
	struct snddev_info *d;
	int err, newcnt;

	d = oidp->oid_arg1;

	newcnt = d->vchancount;
	err = sysctl_handle_int(oidp, &newcnt, sizeof(newcnt), req);

	if (err == 0 && req->newptr != NULL && d->vchancount != newcnt)
		err = pcm_setvchans(d, newcnt);

	return err;
}
#endif

/************************************************************************/

/**
 * @brief	Handle OSSv4 SNDCTL_SYSINFO ioctl.
 *
 * @param si	Pointer to oss_sysinfo struct where information about the
 * 		sound subsystem will be written/copied.
 *
 * This routine returns information about the sound system, such as the
 * current OSS version, number of audio, MIDI, and mixer drivers, etc.
 * Also includes a bitmask showing which of the above types of devices
 * are open (busy).
 *
 * @note
 * Calling threads must not hold any snddev_info or pcm_channel locks.
 *
 * @author	Ryan Beasley <ryanb@FreeBSD.org>
 */
void
sound_oss_sysinfo(oss_sysinfo *si)
{
	static char si_product[] = "FreeBSD native OSS ABI";
	static char si_version[] = __XSTRING(__FreeBSD_version);
	static int intnbits = sizeof(int) * 8;	/* Better suited as macro?
						   Must pester a C guru. */

	struct snddev_channel *sce;
	struct snddev_info *d;
	struct pcm_channel *c;
	int i, j, ncards;
	
	ncards = 0;

	strlcpy(si->product, si_product, sizeof(si->product));
	strlcpy(si->version, si_version, sizeof(si->version));
	si->versionnum = SOUND_VERSION;

	/*
	 * Iterate over PCM devices and their channels, gathering up data
	 * for the numaudios, ncards, and openedaudio fields.
	 */
	si->numaudios = 0;
	bzero((void *)&si->openedaudio, sizeof(si->openedaudio));

	if (pcm_devclass != NULL) {
		j = 0;

		for (i = 0; i < devclass_get_maxunit(pcm_devclass); i++) {
			d = devclass_get_softc(pcm_devclass, i);
			if (!d)
				continue;

			/* See note in function's docblock */
			mtx_assert(d->lock, MA_NOTOWNED);
			/* Increment device's "operations in progress" */
			pcm_inprog(d, 1);
			pcm_lock(d);

			si->numaudios += d->devcount;
			++ncards;

			SLIST_FOREACH(sce, &d->channels, link) {
				c = sce->channel;
				mtx_assert(c->lock, MA_NOTOWNED);
				CHN_LOCK(c);
				if (c->flags & CHN_F_BUSY)
					si->openedaudio[j / intnbits] |=
					    (1 << (j % intnbits));
				CHN_UNLOCK(c);
				j++;
			}

			pcm_unlock(d);
			pcm_inprog(d, -1);
		}
	}

	si->numsynths = 0;	/* OSSv4 docs:  this field is obsolete */
	/**
	 * @todo	Collect num{midis,timers}.
	 *
	 * Need access to sound/midi/midi.c::midistat_lock in order
	 * to safely touch midi_devices and get a head count of, well,
	 * MIDI devices.  midistat_lock is a global static (i.e., local to
	 * midi.c), but midi_devices is a regular global; should the mutex
	 * be publicized, or is there another way to get this information?
	 *
	 * NB:	MIDI/sequencer stuff is currently on hold.
	 */
	si->nummidis = 0;
	si->numtimers = 0;
	si->nummixers = mixer_count;
	si->numcards = ncards;
		/* OSSv4 docs:	Intended only for test apps; API doesn't
		   really have much of a concept of cards.  Shouldn't be
		   used by applications. */

	/**
	 * @todo	Fill in "busy devices" fields.
	 *
	 *  si->openedmidi = " MIDI devices
	 */
	bzero((void *)&si->openedmidi, sizeof(si->openedmidi));

	/*
	 * Si->filler is a reserved array, but according to docs each
	 * element should be set to -1.
	 */
	for (i = 0; i < sizeof(si->filler)/sizeof(si->filler[0]); i++)
		si->filler[i] = -1;
}

/************************************************************************/

static int
sound_modevent(module_t mod, int type, void *data)
{
	int ret;
#if 0
	return (midi_modevent(mod, type, data));
#else
	ret = 0;

	switch(type) {
		case MOD_LOAD:
			pcmsg_unrhdr = new_unrhdr(1, INT_MAX, NULL);
			break;
		case MOD_UNLOAD:
		case MOD_SHUTDOWN:
			if (pcmsg_unrhdr != NULL) {
				delete_unrhdr(pcmsg_unrhdr);
				pcmsg_unrhdr = NULL;
			}
			break;
		default:
			ret = EOPNOTSUPP;
	}

	return ret;
#endif
}

DEV_MODULE(sound, sound_modevent, NULL);
MODULE_VERSION(sound, SOUND_MODVER);