1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2005-2009 Ariff Abdullah <ariff@FreeBSD.org>
5 * Portions Copyright (c) Ryan Beasley <ryan.beasley@gmail.com> - GSoC 2006
6 * Copyright (c) 1999 Cameron Grant <cg@FreeBSD.org>
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#ifdef HAVE_KERNEL_OPTION_HEADERS
32#include "opt_snd.h"
33#endif
34
35#include <dev/sound/pcm/sound.h>
36
37#include "feeder_if.h"
38
39#define SND_USE_FXDIV
40#define	SND_DECLARE_FXDIV
41#include "snd_fxdiv_gen.h"
42
43SND_DECLARE_FILE("$FreeBSD$");
44
45struct snd_dbuf *
46sndbuf_create(device_t dev, char *drv, char *desc, struct pcm_channel *channel)
47{
48	struct snd_dbuf *b;
49
50	b = malloc(sizeof(*b), M_DEVBUF, M_WAITOK | M_ZERO);
51	snprintf(b->name, SNDBUF_NAMELEN, "%s:%s", drv, desc);
52	b->dev = dev;
53	b->channel = channel;
54
55	return b;
56}
57
58void
59sndbuf_destroy(struct snd_dbuf *b)
60{
61	sndbuf_free(b);
62	free(b, M_DEVBUF);
63}
64
65bus_addr_t
66sndbuf_getbufaddr(struct snd_dbuf *buf)
67{
68	return (buf->buf_addr);
69}
70
71static void
72sndbuf_setmap(void *arg, bus_dma_segment_t *segs, int nseg, int error)
73{
74	struct snd_dbuf *b = (struct snd_dbuf *)arg;
75
76	if (snd_verbose > 3) {
77		device_printf(b->dev, "sndbuf_setmap %lx, %lx; ",
78		    (u_long)segs[0].ds_addr, (u_long)segs[0].ds_len);
79		printf("%p -> %lx\n", b->buf, (u_long)segs[0].ds_addr);
80	}
81	if (error == 0)
82		b->buf_addr = segs[0].ds_addr;
83	else
84		b->buf_addr = 0;
85}
86
87/*
88 * Allocate memory for DMA buffer. If the device does not use DMA transfers,
89 * the driver can call malloc(9) and sndbuf_setup() itself.
90 */
91
92int
93sndbuf_alloc(struct snd_dbuf *b, bus_dma_tag_t dmatag, int dmaflags,
94    unsigned int size)
95{
96	int ret;
97
98	b->dmatag = dmatag;
99	b->dmaflags = dmaflags | BUS_DMA_NOWAIT | BUS_DMA_COHERENT;
100	b->maxsize = size;
101	b->bufsize = b->maxsize;
102	b->buf_addr = 0;
103	b->flags |= SNDBUF_F_MANAGED;
104	if (bus_dmamem_alloc(b->dmatag, (void **)&b->buf, b->dmaflags,
105	    &b->dmamap)) {
106		sndbuf_free(b);
107		return (ENOMEM);
108	}
109	if (bus_dmamap_load(b->dmatag, b->dmamap, b->buf, b->maxsize,
110	    sndbuf_setmap, b, 0) != 0 || b->buf_addr == 0) {
111		sndbuf_free(b);
112		return (ENOMEM);
113	}
114
115	ret = sndbuf_resize(b, 2, b->maxsize / 2);
116	if (ret != 0)
117		sndbuf_free(b);
118
119	return (ret);
120}
121
122int
123sndbuf_setup(struct snd_dbuf *b, void *buf, unsigned int size)
124{
125	b->flags &= ~SNDBUF_F_MANAGED;
126	if (buf)
127		b->flags |= SNDBUF_F_MANAGED;
128	b->buf = buf;
129	b->maxsize = size;
130	b->bufsize = b->maxsize;
131	return sndbuf_resize(b, 2, b->maxsize / 2);
132}
133
134void
135sndbuf_free(struct snd_dbuf *b)
136{
137	if (b->tmpbuf)
138		free(b->tmpbuf, M_DEVBUF);
139
140	if (b->shadbuf)
141		free(b->shadbuf, M_DEVBUF);
142
143	if (b->buf) {
144		if (b->flags & SNDBUF_F_MANAGED) {
145			if (b->buf_addr)
146				bus_dmamap_unload(b->dmatag, b->dmamap);
147			if (b->dmatag)
148				bus_dmamem_free(b->dmatag, b->buf, b->dmamap);
149		} else
150			free(b->buf, M_DEVBUF);
151	}
152
153	b->tmpbuf = NULL;
154	b->shadbuf = NULL;
155	b->buf = NULL;
156	b->sl = 0;
157	b->dmatag = NULL;
158	b->dmamap = NULL;
159}
160
161#define SNDBUF_CACHE_SHIFT	5
162
163int
164sndbuf_resize(struct snd_dbuf *b, unsigned int blkcnt, unsigned int blksz)
165{
166	unsigned int bufsize, allocsize;
167	u_int8_t *tmpbuf;
168
169	CHN_LOCK(b->channel);
170	if (b->maxsize == 0)
171		goto out;
172	if (blkcnt == 0)
173		blkcnt = b->blkcnt;
174	if (blksz == 0)
175		blksz = b->blksz;
176	if (blkcnt < 2 || blksz < 16 || (blkcnt * blksz) > b->maxsize) {
177		CHN_UNLOCK(b->channel);
178		return EINVAL;
179	}
180	if (blkcnt == b->blkcnt && blksz == b->blksz)
181		goto out;
182
183	bufsize = blkcnt * blksz;
184
185	if (bufsize > b->allocsize ||
186	    bufsize < (b->allocsize >> SNDBUF_CACHE_SHIFT)) {
187		allocsize = round_page(bufsize);
188		CHN_UNLOCK(b->channel);
189		tmpbuf = malloc(allocsize, M_DEVBUF, M_WAITOK);
190		CHN_LOCK(b->channel);
191		if (snd_verbose > 3)
192			printf("%s(): b=%p %p -> %p [%d -> %d : %d]\n",
193			    __func__, b, b->tmpbuf, tmpbuf,
194			    b->allocsize, allocsize, bufsize);
195		if (b->tmpbuf != NULL)
196			free(b->tmpbuf, M_DEVBUF);
197		b->tmpbuf = tmpbuf;
198		b->allocsize = allocsize;
199	} else if (snd_verbose > 3)
200		printf("%s(): b=%p %d [%d] NOCHANGE\n",
201		    __func__, b, b->allocsize, b->bufsize);
202
203	b->blkcnt = blkcnt;
204	b->blksz = blksz;
205	b->bufsize = bufsize;
206
207	sndbuf_reset(b);
208out:
209	CHN_UNLOCK(b->channel);
210	return 0;
211}
212
213int
214sndbuf_remalloc(struct snd_dbuf *b, unsigned int blkcnt, unsigned int blksz)
215{
216        unsigned int bufsize, allocsize;
217	u_int8_t *buf, *tmpbuf, *shadbuf;
218
219	if (blkcnt < 2 || blksz < 16)
220		return EINVAL;
221
222	bufsize = blksz * blkcnt;
223
224	if (bufsize > b->allocsize ||
225	    bufsize < (b->allocsize >> SNDBUF_CACHE_SHIFT)) {
226		allocsize = round_page(bufsize);
227		CHN_UNLOCK(b->channel);
228		buf = malloc(allocsize, M_DEVBUF, M_WAITOK);
229		tmpbuf = malloc(allocsize, M_DEVBUF, M_WAITOK);
230		shadbuf = malloc(allocsize, M_DEVBUF, M_WAITOK);
231		CHN_LOCK(b->channel);
232		if (b->buf != NULL)
233			free(b->buf, M_DEVBUF);
234		b->buf = buf;
235		if (b->tmpbuf != NULL)
236			free(b->tmpbuf, M_DEVBUF);
237		b->tmpbuf = tmpbuf;
238		if (b->shadbuf != NULL)
239			free(b->shadbuf, M_DEVBUF);
240		b->shadbuf = shadbuf;
241		if (snd_verbose > 3)
242			printf("%s(): b=%p %d -> %d [%d]\n",
243			    __func__, b, b->allocsize, allocsize, bufsize);
244		b->allocsize = allocsize;
245	} else if (snd_verbose > 3)
246		printf("%s(): b=%p %d [%d] NOCHANGE\n",
247		    __func__, b, b->allocsize, b->bufsize);
248
249	b->blkcnt = blkcnt;
250	b->blksz = blksz;
251	b->bufsize = bufsize;
252	b->maxsize = bufsize;
253	b->sl = bufsize;
254
255	sndbuf_reset(b);
256
257	return 0;
258}
259
260/**
261 * @brief Zero out space in buffer free area
262 *
263 * This function clears a chunk of @c length bytes in the buffer free area
264 * (i.e., where the next write will be placed).
265 *
266 * @param b		buffer context
267 * @param length	number of bytes to blank
268 */
269void
270sndbuf_clear(struct snd_dbuf *b, unsigned int length)
271{
272	int i;
273	u_char data, *p;
274
275	if (length == 0)
276		return;
277	if (length > b->bufsize)
278		length = b->bufsize;
279
280	data = sndbuf_zerodata(b->fmt);
281
282	i = sndbuf_getfreeptr(b);
283	p = sndbuf_getbuf(b);
284	while (length > 0) {
285		p[i] = data;
286		length--;
287		i++;
288		if (i >= b->bufsize)
289			i = 0;
290	}
291}
292
293/**
294 * @brief Zap buffer contents, resetting "ready area" fields
295 *
296 * @param b	buffer context
297 */
298void
299sndbuf_fillsilence(struct snd_dbuf *b)
300{
301	if (b->bufsize > 0)
302		memset(sndbuf_getbuf(b), sndbuf_zerodata(b->fmt), b->bufsize);
303	b->rp = 0;
304	b->rl = b->bufsize;
305}
306
307void
308sndbuf_fillsilence_rl(struct snd_dbuf *b, u_int rl)
309{
310	if (b->bufsize > 0)
311		memset(sndbuf_getbuf(b), sndbuf_zerodata(b->fmt), b->bufsize);
312	b->rp = 0;
313	b->rl = min(b->bufsize, rl);
314}
315
316/**
317 * @brief Reset buffer w/o flushing statistics
318 *
319 * This function just zeroes out buffer contents and sets the "ready length"
320 * to zero.  This was originally to facilitate minimal playback interruption
321 * (i.e., dropped samples) in SNDCTL_DSP_SILENCE/SKIP ioctls.
322 *
323 * @param b	buffer context
324 */
325void
326sndbuf_softreset(struct snd_dbuf *b)
327{
328	b->rl = 0;
329	if (b->buf && b->bufsize > 0)
330		sndbuf_clear(b, b->bufsize);
331}
332
333void
334sndbuf_reset(struct snd_dbuf *b)
335{
336	b->hp = 0;
337	b->rp = 0;
338	b->rl = 0;
339	b->dl = 0;
340	b->prev_total = 0;
341	b->total = 0;
342	b->xrun = 0;
343	if (b->buf && b->bufsize > 0)
344		sndbuf_clear(b, b->bufsize);
345	sndbuf_clearshadow(b);
346}
347
348u_int32_t
349sndbuf_getfmt(struct snd_dbuf *b)
350{
351	return b->fmt;
352}
353
354int
355sndbuf_setfmt(struct snd_dbuf *b, u_int32_t fmt)
356{
357	b->fmt = fmt;
358	b->bps = AFMT_BPS(b->fmt);
359	b->align = AFMT_ALIGN(b->fmt);
360#if 0
361	b->bps = AFMT_CHANNEL(b->fmt);
362	if (b->fmt & AFMT_16BIT)
363		b->bps <<= 1;
364	else if (b->fmt & AFMT_24BIT)
365		b->bps *= 3;
366	else if (b->fmt & AFMT_32BIT)
367		b->bps <<= 2;
368#endif
369	return 0;
370}
371
372unsigned int
373sndbuf_getspd(struct snd_dbuf *b)
374{
375	return b->spd;
376}
377
378void
379sndbuf_setspd(struct snd_dbuf *b, unsigned int spd)
380{
381	b->spd = spd;
382}
383
384unsigned int
385sndbuf_getalign(struct snd_dbuf *b)
386{
387	return (b->align);
388}
389
390unsigned int
391sndbuf_getblkcnt(struct snd_dbuf *b)
392{
393	return b->blkcnt;
394}
395
396void
397sndbuf_setblkcnt(struct snd_dbuf *b, unsigned int blkcnt)
398{
399	b->blkcnt = blkcnt;
400}
401
402unsigned int
403sndbuf_getblksz(struct snd_dbuf *b)
404{
405	return b->blksz;
406}
407
408void
409sndbuf_setblksz(struct snd_dbuf *b, unsigned int blksz)
410{
411	b->blksz = blksz;
412}
413
414unsigned int
415sndbuf_getbps(struct snd_dbuf *b)
416{
417	return b->bps;
418}
419
420void *
421sndbuf_getbuf(struct snd_dbuf *b)
422{
423	return b->buf;
424}
425
426void *
427sndbuf_getbufofs(struct snd_dbuf *b, unsigned int ofs)
428{
429	KASSERT(ofs < b->bufsize, ("%s: ofs invalid %d", __func__, ofs));
430
431	return b->buf + ofs;
432}
433
434unsigned int
435sndbuf_getsize(struct snd_dbuf *b)
436{
437	return b->bufsize;
438}
439
440unsigned int
441sndbuf_getmaxsize(struct snd_dbuf *b)
442{
443	return b->maxsize;
444}
445
446unsigned int
447sndbuf_getallocsize(struct snd_dbuf *b)
448{
449	return b->allocsize;
450}
451
452unsigned int
453sndbuf_runsz(struct snd_dbuf *b)
454{
455	return b->dl;
456}
457
458void
459sndbuf_setrun(struct snd_dbuf *b, int go)
460{
461	b->dl = go? b->blksz : 0;
462}
463
464struct selinfo *
465sndbuf_getsel(struct snd_dbuf *b)
466{
467	return &b->sel;
468}
469
470/************************************************************/
471unsigned int
472sndbuf_getxrun(struct snd_dbuf *b)
473{
474	SNDBUF_LOCKASSERT(b);
475
476	return b->xrun;
477}
478
479void
480sndbuf_setxrun(struct snd_dbuf *b, unsigned int xrun)
481{
482	SNDBUF_LOCKASSERT(b);
483
484	b->xrun = xrun;
485}
486
487unsigned int
488sndbuf_gethwptr(struct snd_dbuf *b)
489{
490	SNDBUF_LOCKASSERT(b);
491
492	return b->hp;
493}
494
495void
496sndbuf_sethwptr(struct snd_dbuf *b, unsigned int ptr)
497{
498	SNDBUF_LOCKASSERT(b);
499
500	b->hp = ptr;
501}
502
503unsigned int
504sndbuf_getready(struct snd_dbuf *b)
505{
506	SNDBUF_LOCKASSERT(b);
507	KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
508
509	return b->rl;
510}
511
512unsigned int
513sndbuf_getreadyptr(struct snd_dbuf *b)
514{
515	SNDBUF_LOCKASSERT(b);
516	KASSERT((b->rp >= 0) && (b->rp <= b->bufsize), ("%s: b->rp invalid %d", __func__, b->rp));
517
518	return b->rp;
519}
520
521unsigned int
522sndbuf_getfree(struct snd_dbuf *b)
523{
524	SNDBUF_LOCKASSERT(b);
525	KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
526
527	return b->bufsize - b->rl;
528}
529
530unsigned int
531sndbuf_getfreeptr(struct snd_dbuf *b)
532{
533	SNDBUF_LOCKASSERT(b);
534	KASSERT((b->rp >= 0) && (b->rp <= b->bufsize), ("%s: b->rp invalid %d", __func__, b->rp));
535	KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
536
537	return (b->rp + b->rl) % b->bufsize;
538}
539
540u_int64_t
541sndbuf_getblocks(struct snd_dbuf *b)
542{
543	SNDBUF_LOCKASSERT(b);
544
545	return b->total / b->blksz;
546}
547
548u_int64_t
549sndbuf_getprevblocks(struct snd_dbuf *b)
550{
551	SNDBUF_LOCKASSERT(b);
552
553	return b->prev_total / b->blksz;
554}
555
556u_int64_t
557sndbuf_gettotal(struct snd_dbuf *b)
558{
559	SNDBUF_LOCKASSERT(b);
560
561	return b->total;
562}
563
564u_int64_t
565sndbuf_getprevtotal(struct snd_dbuf *b)
566{
567	SNDBUF_LOCKASSERT(b);
568
569	return b->prev_total;
570}
571
572void
573sndbuf_updateprevtotal(struct snd_dbuf *b)
574{
575	SNDBUF_LOCKASSERT(b);
576
577	b->prev_total = b->total;
578}
579
580unsigned int
581sndbuf_xbytes(unsigned int v, struct snd_dbuf *from, struct snd_dbuf *to)
582{
583	if (from == NULL || to == NULL || v == 0)
584		return 0;
585
586	return snd_xbytes(v, sndbuf_getalign(from) * sndbuf_getspd(from),
587	    sndbuf_getalign(to) * sndbuf_getspd(to));
588}
589
590u_int8_t
591sndbuf_zerodata(u_int32_t fmt)
592{
593	if (fmt & (AFMT_SIGNED | AFMT_PASSTHROUGH))
594		return (0x00);
595	else if (fmt & AFMT_MU_LAW)
596		return (0x7f);
597	else if (fmt & AFMT_A_LAW)
598		return (0x55);
599	return (0x80);
600}
601
602/************************************************************/
603
604/**
605 * @brief Acquire buffer space to extend ready area
606 *
607 * This function extends the ready area length by @c count bytes, and may
608 * optionally copy samples from another location stored in @c from.  The
609 * counter @c snd_dbuf::total is also incremented by @c count bytes.
610 *
611 * @param b	audio buffer
612 * @param from	sample source (optional)
613 * @param count	number of bytes to acquire
614 *
615 * @retval 0	Unconditional
616 */
617int
618sndbuf_acquire(struct snd_dbuf *b, u_int8_t *from, unsigned int count)
619{
620	int l;
621
622	KASSERT(count <= sndbuf_getfree(b), ("%s: count %d > free %d", __func__, count, sndbuf_getfree(b)));
623	KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
624	b->total += count;
625	if (from != NULL) {
626		while (count > 0) {
627			l = min(count, sndbuf_getsize(b) - sndbuf_getfreeptr(b));
628			bcopy(from, sndbuf_getbufofs(b, sndbuf_getfreeptr(b)), l);
629			from += l;
630			b->rl += l;
631			count -= l;
632		}
633	} else
634		b->rl += count;
635	KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d, count %d", __func__, b->rl, count));
636
637	return 0;
638}
639
640/**
641 * @brief Dispose samples from channel buffer, increasing size of ready area
642 *
643 * This function discards samples from the supplied buffer by advancing the
644 * ready area start pointer and decrementing the ready area length.  If
645 * @c to is not NULL, then the discard samples will be copied to the location
646 * it points to.
647 *
648 * @param b	PCM channel sound buffer
649 * @param to	destination buffer (optional)
650 * @param count	number of bytes to discard
651 *
652 * @returns 0 unconditionally
653 */
654int
655sndbuf_dispose(struct snd_dbuf *b, u_int8_t *to, unsigned int count)
656{
657	int l;
658
659	KASSERT(count <= sndbuf_getready(b), ("%s: count %d > ready %d", __func__, count, sndbuf_getready(b)));
660	KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
661	if (to != NULL) {
662		while (count > 0) {
663			l = min(count, sndbuf_getsize(b) - sndbuf_getreadyptr(b));
664			bcopy(sndbuf_getbufofs(b, sndbuf_getreadyptr(b)), to, l);
665			to += l;
666			b->rl -= l;
667			b->rp = (b->rp + l) % b->bufsize;
668			count -= l;
669		}
670	} else {
671		b->rl -= count;
672		b->rp = (b->rp + count) % b->bufsize;
673	}
674	KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d, count %d", __func__, b->rl, count));
675
676	return 0;
677}
678
679#ifdef SND_DIAGNOSTIC
680static uint32_t snd_feeder_maxfeed = 0;
681SYSCTL_UINT(_hw_snd, OID_AUTO, feeder_maxfeed, CTLFLAG_RD,
682    &snd_feeder_maxfeed, 0, "maximum feeder count request");
683
684static uint32_t snd_feeder_maxcycle = 0;
685SYSCTL_UINT(_hw_snd, OID_AUTO, feeder_maxcycle, CTLFLAG_RD,
686    &snd_feeder_maxcycle, 0, "maximum feeder cycle");
687#endif
688
689/* count is number of bytes we want added to destination buffer */
690int
691sndbuf_feed(struct snd_dbuf *from, struct snd_dbuf *to, struct pcm_channel *channel, struct pcm_feeder *feeder, unsigned int count)
692{
693	unsigned int cnt, maxfeed;
694#ifdef SND_DIAGNOSTIC
695	unsigned int cycle;
696
697	if (count > snd_feeder_maxfeed)
698		snd_feeder_maxfeed = count;
699
700	cycle = 0;
701#endif
702
703	KASSERT(count > 0, ("can't feed 0 bytes"));
704
705	if (sndbuf_getfree(to) < count)
706		return (EINVAL);
707
708	maxfeed = SND_FXROUND(SND_FXDIV_MAX, sndbuf_getalign(to));
709
710	do {
711		cnt = FEEDER_FEED(feeder, channel, to->tmpbuf,
712		    min(count, maxfeed), from);
713		if (cnt == 0)
714			break;
715		sndbuf_acquire(to, to->tmpbuf, cnt);
716		count -= cnt;
717#ifdef SND_DIAGNOSTIC
718		cycle++;
719#endif
720	} while (count != 0);
721
722#ifdef SND_DIAGNOSTIC
723	if (cycle > snd_feeder_maxcycle)
724		snd_feeder_maxcycle = cycle;
725#endif
726
727	return (0);
728}
729
730/************************************************************/
731
732void
733sndbuf_dump(struct snd_dbuf *b, char *s, u_int32_t what)
734{
735	printf("%s: [", s);
736	if (what & 0x01)
737		printf(" bufsize: %d, maxsize: %d", b->bufsize, b->maxsize);
738	if (what & 0x02)
739		printf(" dl: %d, rp: %d, rl: %d, hp: %d", b->dl, b->rp, b->rl, b->hp);
740	if (what & 0x04)
741		printf(" total: %ju, prev_total: %ju, xrun: %d", (uintmax_t)b->total, (uintmax_t)b->prev_total, b->xrun);
742   	if (what & 0x08)
743		printf(" fmt: 0x%x, spd: %d", b->fmt, b->spd);
744	if (what & 0x10)
745		printf(" blksz: %d, blkcnt: %d, flags: 0x%x", b->blksz, b->blkcnt, b->flags);
746	printf(" ]\n");
747}
748
749/************************************************************/
750u_int32_t
751sndbuf_getflags(struct snd_dbuf *b)
752{
753	return b->flags;
754}
755
756void
757sndbuf_setflags(struct snd_dbuf *b, u_int32_t flags, int on)
758{
759	b->flags &= ~flags;
760	if (on)
761		b->flags |= flags;
762}
763
764/**
765 * @brief Clear the shadow buffer by filling with samples equal to zero.
766 *
767 * @param b buffer to clear
768 */
769void
770sndbuf_clearshadow(struct snd_dbuf *b)
771{
772	KASSERT(b != NULL, ("b is a null pointer"));
773	KASSERT(b->sl >= 0, ("illegal shadow length"));
774
775	if ((b->shadbuf != NULL) && (b->sl > 0))
776		memset(b->shadbuf, sndbuf_zerodata(b->fmt), b->sl);
777}
778
779#ifdef OSSV4_EXPERIMENT
780/**
781 * @brief Return peak value from samples in buffer ready area.
782 *
783 * Peak ranges from 0-32767.  If channel is monaural, most significant 16
784 * bits will be zero.  For now, only expects to work with 1-2 channel
785 * buffers.
786 *
787 * @note  Currently only operates with linear PCM formats.
788 *
789 * @param b buffer to analyze
790 * @param lpeak pointer to store left peak value
791 * @param rpeak pointer to store right peak value
792 */
793void
794sndbuf_getpeaks(struct snd_dbuf *b, int *lp, int *rp)
795{
796	u_int32_t lpeak, rpeak;
797
798	lpeak = 0;
799	rpeak = 0;
800
801	/**
802	 * @todo fill this in later
803	 */
804}
805#endif
806