update code dealing with snd_dbuf objects to do so using a functional interface

modify chn_setblocksize() to pick a default soft-blocksize appropriate to the
sample rate and format in use.  it will aim for a power of two size small
enough to generate block sizes of at most 20ms.  it will also set the
hard-blocksize taking into account rate/format conversions in use.

update drivers to implement setblocksize  correctly:
updated, tested: 	sb16, emu10k1, maestro, solo
updated, untested: 	ad1816, ess, mss, sb8, csa
not updated: 		ds1, es137x, fm801, neomagic, t4dwave, via82c686

i lack hardware to test: ad1816, csa, fm801, neomagic
others will be updated/tested in the next few days.

11 files changed, 120 insertions, 88 deletions

diff --git a/sys/dev/sound/pci/aureal.c b/sys/dev/sound/pci/aureal.c
index e957b07..09ead9f 100644
--- a/sys/dev/sound/pci/aureal.c
+++ b/sys/dev/sound/pci/aureal.c
@@ -242,7 +242,7 @@ au_prepareoutput(struct au_chinfo *ch, u_int32_t format)
 {
 	struct au_info *au = ch->parent;
 	int i, stereo = (format & AFMT_STEREO)? 1 : 0;
-	u_int32_t baseaddr = vtophys(ch->buffer->buf);
+	u_int32_t baseaddr = vtophys(sndbuf_getbuf(ch->buffer));
 
 	au_wr(au, 0, 0x1061c, 0, 4);
 	au_wr(au, 0, 0x10620, 0, 4);
@@ -301,9 +301,8 @@ auchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = au;
 	ch->channel = c;
 	ch->buffer = b;
-	ch->buffer->bufsize = AU_BUFFSIZE;
 	ch->dir = dir;
-	if (chn_allocbuf(ch->buffer, au->parent_dmat) == -1) return NULL;
+	if (sndbuf_alloc(ch->buffer, au->parent_dmat, AU_BUFFSIZE) == -1) return NULL;
 	return ch;
 }
 
diff --git a/sys/dev/sound/pci/csapcm.c b/sys/dev/sound/pci/csapcm.c
index c3ae93e..8bad7b5 100644
--- a/sys/dev/sound/pci/csapcm.c
+++ b/sys/dev/sound/pci/csapcm.c
@@ -523,8 +523,7 @@ csachan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = csa;
 	ch->channel = c;
 	ch->buffer = b;
-	ch->buffer->bufsize = CS461x_BUFFSIZE;
-	if (chn_allocbuf(ch->buffer, csa->parent_dmat) == -1) return NULL;
+	if (sndbuf_alloc(ch->buffer, csa->parent_dmat, CS461x_BUFFSIZE) == -1) return NULL;
 	return ch;
 }
 
@@ -538,9 +537,9 @@ csachan_setdir(kobj_t obj, void *data, int dir)
 	resp = &csa->res;
 
 	if (dir == PCMDIR_PLAY)
-		csa_writemem(resp, BA1_PBA, vtophys(ch->buffer->buf));
+		csa_writemem(resp, BA1_PBA, vtophys(sndbuf_getbuf(ch->buffer)));
 	else
-		csa_writemem(resp, BA1_CBA, vtophys(ch->buffer->buf));
+		csa_writemem(resp, BA1_CBA, vtophys(sndbuf_getbuf(ch->buffer)));
 	ch->dir = dir;
 	return 0;
 }
@@ -606,12 +605,7 @@ csachan_setspeed(kobj_t obj, void *data, u_int32_t speed)
 static int
 csachan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
-#if notdef
-	return blocksize;
-#else
-	struct csa_chinfo *ch = data;
-	return ch->buffer->bufsize / 2;
-#endif /* notdef */
+	return CS461x_BUFFSIZE / 2;
 }
 
 static int
@@ -648,11 +642,11 @@ csachan_getptr(kobj_t obj, void *data)
 	resp = &csa->res;
 
 	if (ch->dir == PCMDIR_PLAY) {
-		ptr = csa_readmem(resp, BA1_PBA) - vtophys(ch->buffer->buf);
+		ptr = csa_readmem(resp, BA1_PBA) - vtophys(sndbuf_getbuf(ch->buffer));
 		if ((ch->fmt & AFMT_U8) != 0 || (ch->fmt & AFMT_S8) != 0)
 			ptr >>= 1;
 	} else {
-		ptr = csa_readmem(resp, BA1_CBA) - vtophys(ch->buffer->buf);
+		ptr = csa_readmem(resp, BA1_CBA) - vtophys(sndbuf_getbuf(ch->buffer));
 		if ((ch->fmt & AFMT_U8) != 0 || (ch->fmt & AFMT_S8) != 0)
 			ptr >>= 1;
 	}
diff --git a/sys/dev/sound/pci/ds1.c b/sys/dev/sound/pci/ds1.c
index c215b5a..5d76502 100644
--- a/sys/dev/sound/pci/ds1.c
+++ b/sys/dev/sound/pci/ds1.c
@@ -431,8 +431,8 @@ ds_setuppch(struct sc_pchinfo *ch)
 	stereo = (ch->fmt & AFMT_STEREO)? 1 : 0;
 	b16 = (ch->fmt & AFMT_16BIT)? 1 : 0;
 	c = stereo? 1 : 0;
-	buf = ch->buffer->buf;
-	sz = ch->buffer->bufsize;
+	buf = sndbuf_getbuf(ch->buffer);
+	sz = sndbuf_getsize(ch->buffer);
 
 	ds_initpbank(ch->lslot, c, stereo, b16, ch->spd, buf, sz);
 	ds_initpbank(ch->lslot + 1, c, stereo, b16, ch->spd, buf, sz);
@@ -450,8 +450,8 @@ ds_setuprch(struct sc_rchinfo *ch)
 
 	stereo = (ch->fmt & AFMT_STEREO)? 1 : 0;
 	b16 = (ch->fmt & AFMT_16BIT)? 1 : 0;
-	buf = ch->buffer->buf;
-	sz = ch->buffer->bufsize;
+	buf = sndbuf_getbuf(ch->buffer);
+	sz = sndbuf_getsize(ch->buffer);
 	pri = (ch->num == DS1_RECPRIMARY)? 1 : 0;
 
 	for (i = 0; i < 2; i++) {
@@ -480,14 +480,13 @@ ds1pchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 
 	ch = &sc->pch[sc->pchn++];
 	ch->buffer = b;
-	ch->buffer->bufsize = 4096;
 	ch->parent = sc;
 	ch->channel = c;
 	ch->dir = dir;
 	ch->fmt = AFMT_U8;
 	ch->spd = 8000;
 	ch->run = 0;
-	if (chn_allocbuf(ch->buffer, sc->parent_dmat) == -1)
+	if (sndbuf_alloc(ch->buffer, sc->parent_dmat, 4096) == -1)
 		return NULL;
 	else {
 		ch->lsnum = sc->pslotfree;
@@ -602,13 +601,12 @@ ds1rchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch = &sc->rch[sc->rchn];
 	ch->num = sc->rchn++;
 	ch->buffer = b;
-	ch->buffer->bufsize = 4096;
 	ch->parent = sc;
 	ch->channel = c;
 	ch->dir = dir;
 	ch->fmt = AFMT_U8;
 	ch->spd = 8000;
-	if (chn_allocbuf(ch->buffer, sc->parent_dmat) == -1)
+	if (sndbuf_alloc(ch->buffer, sc->parent_dmat, 4096) == -1)
 		return NULL;
 	else {
 		ch->slot = (ch->num == DS1_RECPRIMARY)? sc->rbank + 2: sc->rbank;
diff --git a/sys/dev/sound/pci/emu10k1.c b/sys/dev/sound/pci/emu10k1.c
index e199446..e816572 100644
--- a/sys/dev/sound/pci/emu10k1.c
+++ b/sys/dev/sound/pci/emu10k1.c
@@ -68,7 +68,7 @@ struct sc_info;
 
 /* channel registers */
 struct sc_pchinfo {
-	int spd, fmt, run;
+	int spd, fmt, blksz, run;
 	struct emu_voice *master, *slave;
 	snd_dbuf *buffer;
 	pcm_channel *channel;
@@ -76,7 +76,7 @@ struct sc_pchinfo {
 };
 
 struct sc_rchinfo {
-	int spd, fmt, run, num;
+	int spd, fmt, run, blksz, num;
 	u_int32_t idxreg, basereg, sizereg, setupreg, irqmask;
 	snd_dbuf *buffer;
 	pcm_channel *channel;
@@ -97,7 +97,7 @@ struct sc_info {
 	int		regtype, regid, irqid;
 	void		*ih;
 
-	int timer;
+	int timer, timerinterval;
 	int pnum, rnum;
 	struct emu_mem mem;
 	struct emu_voice voice[64];
@@ -303,12 +303,39 @@ emu_enaint(struct sc_info *sc, char channel, int enable)
 
 /* stuff */
 static int
+emu_settimer(struct sc_info *sc)
+{
+	struct sc_pchinfo *pch;
+	struct sc_rchinfo *rch;
+	int i, tmp, rate;
+
+	rate = 0;
+	for (i = 0; i < EMU_CHANS; i++) {
+		pch = &sc->pch[i];
+		tmp = (pch->spd * sndbuf_getbps(pch->buffer)) / pch->blksz;
+		if (tmp > rate)
+			rate = tmp;
+	}
+
+	for (i = 0; i < 3; i++) {
+		rch = &sc->rch[i];
+		tmp = (rch->spd * sndbuf_getbps(rch->buffer)) / rch->blksz;
+		if (tmp > rate)
+			rate = tmp;
+	}
+	RANGE(rate, 48, 9600);
+	sc->timerinterval = 48000 / rate;
+	emu_wr(sc, TIMER, sc->timerinterval & 0x03ff, 2);
+
+	return sc->timerinterval;
+}
+
+static int
 emu_enatimer(struct sc_info *sc, int go)
 {
 	u_int32_t x;
 	if (go) {
 		if (sc->timer++ == 0) {
-			emu_wr(sc, TIMER, 256, 2);
 			x = emu_rd(sc, INTE, 4);
 			x |= INTE_INTERVALTIMERENB;
 			emu_wr(sc, INTE, x, 4);
@@ -430,10 +457,8 @@ emu_vinit(struct sc_info *sc, struct emu_voice *m, struct emu_voice *s,
 	buf = emu_memalloc(sc, sz);
 	if (buf == NULL)
 		return -1;
-	if (c != NULL) {
-		c->buffer.buf = buf;
-		c->buffer.bufsize = sz;
-	}
+	if (c != NULL)
+		sndbuf_setup(&c->buffer, buf, sz);
 	m->start = emu_memstart(sc, buf) * EMUPAGESIZE;
 	m->end = m->start + sz;
 	m->channel = NULL;
@@ -631,6 +656,9 @@ emupchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->buffer = b;
 	ch->parent = sc;
 	ch->channel = c;
+	ch->blksz = EMU_BUFFSIZE / 2;
+	ch->fmt = AFMT_U8;
+	ch->spd = 8000;
 	ch->master = emu_valloc(sc);
 	ch->slave = emu_valloc(sc);
 	if (emu_vinit(sc, ch->master, ch->slave, EMU_BUFFSIZE, ch->channel))
@@ -645,7 +673,7 @@ emupchan_free(kobj_t obj, void *data)
 	struct sc_pchinfo *ch = data;
 	struct sc_info *sc = ch->parent;
 
-	return emu_memfree(sc, ch->buffer->buf);
+	return emu_memfree(sc, sndbuf_getbuf(ch->buffer));
 }
 
 static int
@@ -669,6 +697,14 @@ emupchan_setspeed(kobj_t obj, void *data, u_int32_t speed)
 static int
 emupchan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
+	struct sc_pchinfo *ch = data;
+	struct sc_info *sc = ch->parent;
+	int irqrate, blksz;
+
+	ch->blksz = blocksize;
+	emu_settimer(sc);
+	irqrate = 48000 / sc->timerinterval;
+	blksz = (ch->spd * sndbuf_getbps(ch->buffer)) / irqrate;
 	return blocksize;
 }
 
@@ -684,6 +720,7 @@ emupchan_trigger(kobj_t obj, void *data, int go)
 	if (go == PCMTRIG_START) {
 		emu_vsetup(ch);
 		emu_vwrite(sc, ch->master);
+		emu_settimer(sc);
 		emu_enatimer(sc, 1);
 #ifdef EMUDEBUG
 		printf("start [%d bit, %s, %d hz]\n",
@@ -737,9 +774,9 @@ emurchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	KASSERT(dir == PCMDIR_REC, ("emurchan_init: bad direction"));
 	ch = &sc->rch[sc->rnum];
 	ch->buffer = b;
-	ch->buffer->bufsize = EMU_BUFFSIZE;
 	ch->parent = sc;
 	ch->channel = c;
+	ch->blksz = EMU_BUFFSIZE / 2;
 	ch->fmt = AFMT_U8;
 	ch->spd = 8000;
 	ch->num = sc->rnum;
@@ -769,10 +806,10 @@ emurchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 		break;
 	}
 	sc->rnum++;
-	if (chn_allocbuf(ch->buffer, sc->parent_dmat) == -1)
+	if (sndbuf_alloc(ch->buffer, sc->parent_dmat, EMU_BUFFSIZE) == -1)
 		return NULL;
 	else {
-		emu_wrptr(sc, 0, ch->basereg, vtophys(ch->buffer->buf));
+		emu_wrptr(sc, 0, ch->basereg, vtophys(sndbuf_getbuf(ch->buffer)));
 		emu_wrptr(sc, 0, ch->sizereg, 0); /* off */
 		return ch;
 	}
@@ -805,6 +842,14 @@ emurchan_setspeed(kobj_t obj, void *data, u_int32_t speed)
 static int
 emurchan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
+	struct sc_rchinfo *ch = data;
+	struct sc_info *sc = ch->parent;
+	int irqrate, blksz;
+
+	ch->blksz = blocksize;
+	emu_settimer(sc);
+	irqrate = 48000 / sc->timerinterval;
+	blksz = (ch->spd * sndbuf_getbps(ch->buffer)) / irqrate;
 	return blocksize;
 }
 
diff --git a/sys/dev/sound/pci/es137x.c b/sys/dev/sound/pci/es137x.c
index 15779e8..0206dce 100644
--- a/sys/dev/sound/pci/es137x.c
+++ b/sys/dev/sound/pci/es137x.c
@@ -253,9 +253,8 @@ eschan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = es;
 	ch->channel = c;
 	ch->buffer = b;
-	ch->buffer->bufsize = ES_BUFFSIZE;
 	ch->num = ch->parent->num++;
-	if (chn_allocbuf(ch->buffer, es->parent_dmat) == -1) return NULL;
+	if (sndbuf_alloc(ch->buffer, es->parent_dmat, ES_BUFFSIZE) == -1) return NULL;
 	return ch;
 }
 
@@ -269,16 +268,16 @@ eschan_setdir(kobj_t obj, void *data, int dir)
 		bus_space_write_1(es->st, es->sh, ES1370_REG_MEMPAGE,
 				  ES1370_REG_DAC2_FRAMEADR >> 8);
 		bus_space_write_4(es->st, es->sh, ES1370_REG_DAC2_FRAMEADR & 0xff,
-				  vtophys(ch->buffer->buf));
+				  vtophys(sndbuf_getbuf(ch->buffer)));
 		bus_space_write_4(es->st, es->sh, ES1370_REG_DAC2_FRAMECNT & 0xff,
-				  (ch->buffer->bufsize >> 2) - 1);
+				  (sndbuf_getsize(ch->buffer) >> 2) - 1);
 	} else {
 		bus_space_write_1(es->st, es->sh, ES1370_REG_MEMPAGE,
 				  ES1370_REG_ADC_FRAMEADR >> 8);
 		bus_space_write_4(es->st, es->sh, ES1370_REG_ADC_FRAMEADR & 0xff,
-				  vtophys(ch->buffer->buf));
+				  vtophys(sndbuf_getbuf(ch->buffer)));
 		bus_space_write_4(es->st, es->sh, ES1370_REG_ADC_FRAMECNT & 0xff,
-				  (ch->buffer->bufsize >> 2) - 1);
+				  (sndbuf_getsize(ch->buffer) >> 2) - 1);
 	}
 	ch->dir = dir;
 	return 0;
@@ -346,10 +345,7 @@ eschan_trigger(kobj_t obj, void *data, int go)
 	if (go == PCMTRIG_EMLDMAWR || go == PCMTRIG_EMLDMARD)
 		return 0;
 
-	ss = 1;
-	ss <<= (ch->fmt & AFMT_STEREO)? 1 : 0;
-	ss <<= (ch->fmt & AFMT_16BIT)? 1 : 0;
-	cnt = ch->buffer->dl / ss - 1;
+	cnt = (sndbuf_runsz(ch->buffer) / sndbuf_getbps(ch->buffer)) - 1;
 
 	if (ch->dir == PCMDIR_PLAY) {
 		if (go == PCMTRIG_START) {
@@ -366,7 +362,7 @@ eschan_trigger(kobj_t obj, void *data, int go)
 					  ES1370_REG_DAC2_FRAMECNT >> 8);
 			bus_space_write_4(es->st, es->sh,
 					  ES1370_REG_DAC2_FRAMECNT & 0xff,
-				  	  (ch->buffer->bufsize >> 2) - 1);
+				  	  (sndbuf_getsize(ch->buffer) >> 2) - 1);
 		} else es->ctrl &= ~CTRL_DAC2_EN;
 	} else {
 		if (go == PCMTRIG_START) {
@@ -380,7 +376,7 @@ eschan_trigger(kobj_t obj, void *data, int go)
 					  ES1370_REG_ADC_FRAMECNT >> 8);
 			bus_space_write_4(es->st, es->sh,
 					  ES1370_REG_ADC_FRAMECNT & 0xff,
-				  	  (ch->buffer->bufsize >> 2) - 1);
+				  	  (sndbuf_getsize(ch->buffer) >> 2) - 1);
 		} else es->ctrl &= ~CTRL_ADC_EN;
 	}
 	bus_space_write_4(es->st, es->sh, ES1370_REG_SERIAL_CONTROL, es->sctrl);
diff --git a/sys/dev/sound/pci/fm801.c b/sys/dev/sound/pci/fm801.c
index a01ea8e..33b9915 100644
--- a/sys/dev/sound/pci/fm801.c
+++ b/sys/dev/sound/pci/fm801.c
@@ -331,9 +331,8 @@ fm801ch_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = fm801;
 	ch->channel = c;
 	ch->buffer = b;
-	ch->buffer->bufsize = FM801_BUFFSIZE;
 	ch->dir = dir;
-	if( chn_allocbuf(ch->buffer, fm801->parent_dmat) == -1) return NULL;
+	if (sndbuf_alloc(ch->buffer, fm801->parent_dmat, FM801_BUFFSIZE) == -1) return NULL;
 	return (void *)ch;
 }
 
@@ -435,7 +434,7 @@ fm801ch_trigger(kobj_t obj, void *data, int go)
 {
 	struct fm801_chinfo *ch = data;
 	struct fm801_info *fm801 = ch->parent;
-	u_int32_t baseaddr = vtophys(ch->buffer->buf);
+	u_int32_t baseaddr = vtophys(sndbuf_getbuf(ch->buffer));
 	snd_dbuf *b = ch->buffer;
 	u_int32_t k1;
 
diff --git a/sys/dev/sound/pci/maestro.c b/sys/dev/sound/pci/maestro.c
index 5955f77..82e84bf 100644
--- a/sys/dev/sound/pci/maestro.c
+++ b/sys/dev/sound/pci/maestro.c
@@ -85,6 +85,7 @@ struct agg_chinfo {
 	snd_dbuf		*buffer;
 	bus_addr_t		offset;
 	u_int32_t		blocksize;
+	u_int32_t		speed;
 	int			dir;
 	u_int			num;
 	u_int16_t		aputype;
@@ -518,9 +519,9 @@ aggch_start_dac(struct agg_chinfo *ch)
 {
 	u_int wpwa = APU_USE_SYSMEM | (ch->offset >> 9);
 	u_int size = AGG_BUFSIZ >> 1;
-	u_int speed = ch->channel->speed;
+	u_int speed = ch->speed;
 	u_int offset = ch->offset >> 1;
-	u_int cp = ch->buffer->rp >> 1;
+	u_int cp = 0;
 	u_int16_t apuch = ch->num << 1;
 	u_int dv;
 	int pan = 0;
@@ -613,7 +614,7 @@ calc_timer_freq(struct agg_chinfo *ch)
 	if (ch->aputype == APUTYPE_8BITLINEAR)
 		ss >>= 1;
 
-	return (ch->channel->speed * ss + ch->blocksize - 1) / ch->blocksize;
+	return (ch->speed * ss) / ch->blocksize;
 }
 
 static void
@@ -641,6 +642,7 @@ aggch_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	struct agg_info *ess = devinfo;
 	struct agg_chinfo *ch;
 	bus_addr_t physaddr;
+	void *p;
 
 	ch = (dir == PCMDIR_PLAY)? ess->pch + ess->playchns : &ess->rch;
 
@@ -650,9 +652,10 @@ aggch_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->num = ess->playchns;
 	ch->dir = dir;
 
-	b->buf = dma_malloc(ess, AGG_BUFSIZ, &physaddr);
-	if (b->buf == NULL)
+	p = dma_malloc(ess, AGG_BUFSIZ, &physaddr);
+	if (p == NULL)
 		return NULL;
+	sndbuf_setup(b, p, AGG_BUFSIZ);
 
 	ch->offset = physaddr - ess->baseaddr;
 	if (physaddr < ess->baseaddr || ch->offset > WPWA_MAXADDR) {
@@ -663,7 +666,6 @@ aggch_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 		return NULL;
 	}
 
-	b->bufsize = AGG_BUFSIZ;
 	ch->wcreg_tpl = (physaddr - 16) & WAVCACHE_CHCTL_ADDRTAG_MASK;
 
 	if (dir == PCMDIR_PLAY) {
@@ -683,7 +685,7 @@ aggch_free(kobj_t obj, void *data)
 	struct agg_info *ess = ch->parent;
 
 	/* free up buffer - called after channel stopped */
-	dma_free(ess, ch->buffer->buf);
+	dma_free(ess, sndbuf_getbuf(ch->buffer));
 
 	/* return 0 if ok */
 	return 0;
@@ -719,7 +721,10 @@ aggch_setplayformat(kobj_t obj, void *data, u_int32_t format)
 static int
 aggch_setspeed(kobj_t obj, void *data, u_int32_t speed)
 {
-	return speed;
+	struct agg_chinfo *ch = data;
+
+	ch->speed = speed;
+	return ch->speed;
 }
 
 static int
diff --git a/sys/dev/sound/pci/neomagic.c b/sys/dev/sound/pci/neomagic.c
index 1e2760c..5a6ca8c 100644
--- a/sys/dev/sound/pci/neomagic.c
+++ b/sys/dev/sound/pci/neomagic.c
@@ -338,8 +338,7 @@ nmchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	chnbuf = (dir == PCMDIR_PLAY)? sc->pbuf : sc->rbuf;
 	ch = (dir == PCMDIR_PLAY)? &sc->pch : &sc->rch;
 	ch->buffer = b;
-	ch->buffer->bufsize = NM_BUFFSIZE;
-	ch->buffer->buf = (u_int8_t *)rman_get_virtual(sc->buf) + chnbuf;
+	sndbuf_setup(ch->buffer, (u_int8_t *)rman_get_virtual(sc->buf) + chnbuf, NM_BUFFSIZE);
 	if (bootverbose)
 		device_printf(sc->dev, "%s buf %p\n", (dir == PCMDIR_PLAY)?
 			      "play" : "rec", ch->buffer->buf);
diff --git a/sys/dev/sound/pci/solo.c b/sys/dev/sound/pci/solo.c
index 7cb10f3..71a00f1 100644
--- a/sys/dev/sound/pci/solo.c
+++ b/sys/dev/sound/pci/solo.c
@@ -80,7 +80,7 @@ struct ess_chinfo {
 	pcm_channel *channel;
 	snd_dbuf *buffer;
 	int dir, hwch, stopping;
-	u_int32_t fmt, spd;
+	u_int32_t fmt, spd, blksz;
 };
 
 struct ess_info {
@@ -477,7 +477,7 @@ ess_start(struct ess_chinfo *ch)
 	struct ess_info *sc = ch->parent;
 
 	DEB(printf("ess_start\n"););
-	ess_setupch(sc, ch->hwch, ch->dir, ch->spd, ch->fmt, ch->buffer->dl);
+	ess_setupch(sc, ch->hwch, ch->dir, ch->spd, ch->fmt, ch->blksz);
 	ch->stopping = 0;
 	if (ch->hwch == 1) {
 		ess_write(sc, 0xb8, ess_read(sc, 0xb8) | 0x01);
@@ -519,9 +519,8 @@ esschan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = sc;
 	ch->channel = c;
 	ch->buffer = b;
-	ch->buffer->bufsize = ESS_BUFFSIZE;
 	ch->dir = dir;
-	if (chn_allocbuf(ch->buffer, sc->parent_dmat) == -1)
+	if (sndbuf_alloc(ch->buffer, sc->parent_dmat, ESS_BUFFSIZE) == -1)
 		return NULL;
 	ch->hwch = 1;
 	if ((dir == PCMDIR_PLAY) && (sc->duplex))
@@ -555,7 +554,10 @@ esschan_setspeed(kobj_t obj, void *data, u_int32_t speed)
 static int
 esschan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
-	return blocksize;
+	struct ess_chinfo *ch = data;
+
+	ch->blksz = blocksize;
+	return ch->blksz;
 }
 
 static int
@@ -570,7 +572,7 @@ esschan_trigger(kobj_t obj, void *data, int go)
 
 	switch (go) {
 	case PCMTRIG_START:
-		ess_dmasetup(sc, ch->hwch, vtophys(ch->buffer->buf), ch->buffer->bufsize, ch->dir);
+		ess_dmasetup(sc, ch->hwch, vtophys(sndbuf_getbuf(ch->buffer)), sndbuf_getsize(ch->buffer), ch->dir);
 		ess_dmatrigger(sc, ch->hwch, 1);
 		ess_start(ch);
 		break;
@@ -780,7 +782,7 @@ ess_dmapos(struct ess_info *sc, int ch)
 					i, p);
 			i = port_rd(sc->vc, 0x4, 2) + 1;
 			p = port_rd(sc->vc, 0x4, 2) + 1;
-		} while ((p > sc->dmasz[ch -1 ] || i < p || (p - i) > 0x8) && j++ < 1000);
+		} while ((p > sc->dmasz[ch - 1] || i < p || (p - i) > 0x8) && j++ < 1000);
 		ess_dmatrigger(sc, ch, 1);
 	}
 	else if (ch == 2)
diff --git a/sys/dev/sound/pci/t4dwave.c b/sys/dev/sound/pci/t4dwave.c
index dee0f9f..1dace66 100644
--- a/sys/dev/sound/pci/t4dwave.c
+++ b/sys/dev/sound/pci/t4dwave.c
@@ -52,7 +52,7 @@ struct tr_chinfo {
 	u_int32_t eso, delta;
 	u_int32_t rvol, cvol;
 	u_int32_t gvsel, pan, vol, ctrl;
-	int index, ss;
+	int index;
 	snd_dbuf *buffer;
 	pcm_channel *channel;
 	struct tr_info *parent;
@@ -391,10 +391,9 @@ trchan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 		ch->index = -1;
 	}
 	ch->buffer = b;
-	ch->buffer->bufsize = TR_BUFFSIZE;
 	ch->parent = tr;
 	ch->channel = c;
-	if (chn_allocbuf(ch->buffer, tr->parent_dmat) == -1) return NULL;
+	if (sndbuf_alloc(ch->buffer, tr->parent_dmat, TR_BUFFSIZE) == -1) return NULL;
 	else return ch;
 }
 
@@ -405,9 +404,9 @@ trchan_setdir(kobj_t obj, void *data, int dir)
 	struct tr_info *tr = ch->parent;
 	if (dir == PCMDIR_PLAY && ch->index >= 0) {
 		ch->fmc = ch->fms = ch->ec = ch->alpha = 0;
-		ch->lba = vtophys(ch->buffer->buf);
+		ch->lba = vtophys(sndbuf_getbuf(ch->buffer));
 		ch->cso = 0;
-		ch->eso = ch->buffer->bufsize - 1;
+		ch->eso = sndbuf_getsize(ch->buffer) - 1;
 		ch->rvol = ch->cvol = 0;
 		ch->gvsel = 0;
 		ch->pan = 0;
@@ -423,10 +422,10 @@ trchan_setdir(kobj_t obj, void *data, int dir)
 		i = tr_rd(tr, TR_REG_DMAR11, 1) & 0x03;
 		tr_wr(tr, TR_REG_DMAR11, i | 0x54, 1);
 		/* set up base address */
-	   	tr_wr(tr, TR_REG_DMAR0, vtophys(ch->buffer->buf), 4);
+	   	tr_wr(tr, TR_REG_DMAR0, vtophys(sndbuf_getbuf(ch->buffer)), 4);
 		/* set up buffer size */
 		i = tr_rd(tr, TR_REG_DMAR4, 4) & ~0x00ffffff;
-		tr_wr(tr, TR_REG_DMAR4, i | (ch->buffer->bufsize - 1), 4);
+		tr_wr(tr, TR_REG_DMAR4, i | (sndbuf_getsize(ch->buffer) - 1), 4);
 	} else return -1;
 	return 0;
 }
@@ -438,12 +437,9 @@ trchan_setformat(kobj_t obj, void *data, u_int32_t format)
 	struct tr_info *tr = ch->parent;
 	u_int32_t bits = tr_fmttobits(format);
 
-	ch->ss = 1;
-	ch->ss <<= (format & AFMT_STEREO)? 1 : 0;
-	ch->ss <<= (format & AFMT_16BIT)? 1 : 0;
 	if (ch->index >= 0) {
 		tr_rdch(tr, ch->index, ch);
-		ch->eso = (ch->buffer->bufsize / ch->ss) - 1;
+		ch->eso = (sndbuf_getsize(ch->buffer) / sndbuf_getbps(ch->buffer)) - 1;
 		ch->ctrl = bits | 0x01;
    		tr_wrch(tr, ch->index, ch);
 	} else {
@@ -482,7 +478,7 @@ static int
 trchan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
 	struct tr_chinfo *ch = data;
-	return ch->buffer->bufsize / 2;
+	return sndbuf_getsize(ch->buffer) / 2;
 }
 
 static int
@@ -516,8 +512,8 @@ trchan_getptr(kobj_t obj, void *data)
 
 	if (ch->index >= 0) {
 		tr_rdch(tr, ch->index, ch);
-		return ch->cso * ch->ss;
-	} else return tr_rd(tr, TR_REG_DMAR0, 4) - vtophys(ch->buffer->buf);
+		return ch->cso * sndbuf_getbps(ch->buffer);
+	} else return tr_rd(tr, TR_REG_DMAR0, 4) - vtophys(sndbuf_getbuf(ch->buffer));
 }
 
 static pcmchan_caps *
diff --git a/sys/dev/sound/pci/via82c686.c b/sys/dev/sound/pci/via82c686.c
index 27d7aef..70dd9db 100644
--- a/sys/dev/sound/pci/via82c686.c
+++ b/sys/dev/sound/pci/via82c686.c
@@ -217,9 +217,8 @@ viachan_init(kobj_t obj, void *devinfo, snd_dbuf *b, pcm_channel *c, int dir)
 	ch->parent = via;
 	ch->channel = c;
 	ch->buffer = b;
-	b->bufsize = VIA_BUFFSIZE;
 
-	if (chn_allocbuf(ch->buffer, via->parent_dmat) == -1) return NULL;
+	if (sndbuf_alloc(ch->buffer, via->parent_dmat, VIA_BUFFSIZE) == -1) return NULL;
 	return ch;
 }
 
@@ -240,14 +239,14 @@ viachan_setdir(kobj_t obj, void *data, int dir)
 	 *  is feeding.
 	 */
 	ado = via->sgd_table;
-	chunk_size = ch->buffer->bufsize / SEGS_PER_CHAN;
+	chunk_size = sndbuf_getsize(ch->buffer) / SEGS_PER_CHAN;
 
 	if (dir == PCMDIR_REC) {
 		ado += SEGS_PER_CHAN;
 	}
 
 DEB(printf("SGD table located at va %p\n", ado));
-	phys_addr = vtophys(ch->buffer->buf);
+	phys_addr = vtophys(sndbuf_getbuf(ch->buffer));
 	for (i = 0; i < SEGS_PER_CHAN; i++) {
 		ado->ptr = phys_addr;
 		flag = (i == SEGS_PER_CHAN-1) ?
@@ -339,7 +338,7 @@ viachan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 {
 	struct via_chinfo *ch = data;
 
-	return ch->buffer->bufsize / 2;
+	return sndbuf_getsize(ch->buffer) / 2;
 }
 
 static int
@@ -409,7 +408,7 @@ DEB(printf("viachan_getptr: len / base = %x / %x\n", len, base));
 		if (seg == 0) seg = SEGS_PER_CHAN;
 
 		/* Now work out offset: seg less count */
-		ptr = seg * ch->buffer->bufsize / SEGS_PER_CHAN - len;
+		ptr = seg * sndbuf_getsize(ch->buffer) / SEGS_PER_CHAN - len;
 DEB(printf("return ptr=%d\n", ptr));
 		return ptr;
 	}
@@ -430,7 +429,7 @@ DEB(printf("viachan_getptr: len / base = %x / %x\n", len, base));
 		if (seg == 0) seg = SEGS_PER_CHAN;
 
 		/* Now work out offset: seg less count */
-		ptr = seg * ch->buffer->bufsize / SEGS_PER_CHAN - len;
+		ptr = seg * sndbuf_getsize(ch->buffer) / SEGS_PER_CHAN - len;
 
 		/* DMA appears to operate on memory 'lines' of 32 bytes	*/
 		/* so don't return any part line - it isn't in RAM yet	*/