xref: /freebsd/sys/dev/sound/pcm/buffer.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
43 struct snd_dbuf *
44 sndbuf_create(device_t dev, char *drv, char *desc, struct pcm_channel *channel)
45 {
46 	struct snd_dbuf *b;
47 
48 	b = malloc(sizeof(*b), M_DEVBUF, M_WAITOK | M_ZERO);
49 	snprintf(b->name, SNDBUF_NAMELEN, "%s:%s", drv, desc);
50 	b->dev = dev;
51 	b->channel = channel;
52 
53 	return b;
54 }
55 
56 void
57 sndbuf_destroy(struct snd_dbuf *b)
58 {
59 	sndbuf_free(b);
60 	free(b, M_DEVBUF);
61 }
62 
63 bus_addr_t
64 sndbuf_getbufaddr(struct snd_dbuf *buf)
65 {
66 	return (buf->buf_addr);
67 }
68 
69 static void
70 sndbuf_setmap(void *arg, bus_dma_segment_t *segs, int nseg, int error)
71 {
72 	struct snd_dbuf *b = (struct snd_dbuf *)arg;
73 
74 	if (snd_verbose > 3) {
75 		device_printf(b->dev, "sndbuf_setmap %lx, %lx; ",
76 		    (u_long)segs[0].ds_addr, (u_long)segs[0].ds_len);
77 		printf("%p -> %lx\n", b->buf, (u_long)segs[0].ds_addr);
78 	}
79 	if (error == 0)
80 		b->buf_addr = segs[0].ds_addr;
81 	else
82 		b->buf_addr = 0;
83 }
84 
85 /*
86  * Allocate memory for DMA buffer. If the device does not use DMA transfers,
87  * the driver can call malloc(9) and sndbuf_setup() itself.
88  */
89 
90 int
91 sndbuf_alloc(struct snd_dbuf *b, bus_dma_tag_t dmatag, int dmaflags,
92     unsigned int size)
93 {
94 	int ret;
95 
96 	b->dmatag = dmatag;
97 	b->dmaflags = dmaflags | BUS_DMA_NOWAIT | BUS_DMA_COHERENT;
98 	b->maxsize = size;
99 	b->bufsize = b->maxsize;
100 	b->buf_addr = 0;
101 	b->flags |= SNDBUF_F_MANAGED;
102 	if (bus_dmamem_alloc(b->dmatag, (void **)&b->buf, b->dmaflags,
103 	    &b->dmamap)) {
104 		sndbuf_free(b);
105 		return (ENOMEM);
106 	}
107 	if (bus_dmamap_load(b->dmatag, b->dmamap, b->buf, b->maxsize,
108 	    sndbuf_setmap, b, BUS_DMA_NOWAIT) != 0 || b->buf_addr == 0) {
109 		sndbuf_free(b);
110 		return (ENOMEM);
111 	}
112 
113 	ret = sndbuf_resize(b, 2, b->maxsize / 2);
114 	if (ret != 0)
115 		sndbuf_free(b);
116 
117 	return (ret);
118 }
119 
120 int
121 sndbuf_setup(struct snd_dbuf *b, void *buf, unsigned int size)
122 {
123 	b->flags &= ~SNDBUF_F_MANAGED;
124 	if (buf)
125 		b->flags |= SNDBUF_F_MANAGED;
126 	b->buf = buf;
127 	b->maxsize = size;
128 	b->bufsize = b->maxsize;
129 	return sndbuf_resize(b, 2, b->maxsize / 2);
130 }
131 
132 void
133 sndbuf_free(struct snd_dbuf *b)
134 {
135 	if (b->tmpbuf)
136 		free(b->tmpbuf, M_DEVBUF);
137 
138 	if (b->shadbuf)
139 		free(b->shadbuf, M_DEVBUF);
140 
141 	if (b->buf) {
142 		if (b->flags & SNDBUF_F_MANAGED) {
143 			if (b->buf_addr)
144 				bus_dmamap_unload(b->dmatag, b->dmamap);
145 			if (b->dmatag)
146 				bus_dmamem_free(b->dmatag, b->buf, b->dmamap);
147 		} else
148 			free(b->buf, M_DEVBUF);
149 	}
150 
151 	b->tmpbuf = NULL;
152 	b->shadbuf = NULL;
153 	b->buf = NULL;
154 	b->sl = 0;
155 	b->dmatag = NULL;
156 	b->dmamap = NULL;
157 }
158 
159 #define SNDBUF_CACHE_SHIFT	5
160 
161 int
162 sndbuf_resize(struct snd_dbuf *b, unsigned int blkcnt, unsigned int blksz)
163 {
164 	unsigned int bufsize, allocsize;
165 	u_int8_t *tmpbuf;
166 
167 	CHN_LOCK(b->channel);
168 	if (b->maxsize == 0)
169 		goto out;
170 	if (blkcnt == 0)
171 		blkcnt = b->blkcnt;
172 	if (blksz == 0)
173 		blksz = b->blksz;
174 	if (blkcnt < 2 || blksz < 16 || (blkcnt * blksz) > b->maxsize) {
175 		CHN_UNLOCK(b->channel);
176 		return EINVAL;
177 	}
178 	if (blkcnt == b->blkcnt && blksz == b->blksz)
179 		goto out;
180 
181 	bufsize = blkcnt * blksz;
182 
183 	if (bufsize > b->allocsize ||
184 	    bufsize < (b->allocsize >> SNDBUF_CACHE_SHIFT)) {
185 		allocsize = round_page(bufsize);
186 		CHN_UNLOCK(b->channel);
187 		tmpbuf = malloc(allocsize, M_DEVBUF, M_WAITOK);
188 		CHN_LOCK(b->channel);
189 		if (snd_verbose > 3)
190 			printf("%s(): b=%p %p -> %p [%d -> %d : %d]\n",
191 			    __func__, b, b->tmpbuf, tmpbuf,
192 			    b->allocsize, allocsize, bufsize);
193 		if (b->tmpbuf != NULL)
194 			free(b->tmpbuf, M_DEVBUF);
195 		b->tmpbuf = tmpbuf;
196 		b->allocsize = allocsize;
197 	} else if (snd_verbose > 3)
198 		printf("%s(): b=%p %d [%d] NOCHANGE\n",
199 		    __func__, b, b->allocsize, b->bufsize);
200 
201 	b->blkcnt = blkcnt;
202 	b->blksz = blksz;
203 	b->bufsize = bufsize;
204 
205 	sndbuf_reset(b);
206 out:
207 	CHN_UNLOCK(b->channel);
208 	return 0;
209 }
210 
211 int
212 sndbuf_remalloc(struct snd_dbuf *b, unsigned int blkcnt, unsigned int blksz)
213 {
214         unsigned int bufsize, allocsize;
215 	u_int8_t *buf, *tmpbuf, *shadbuf;
216 
217 	if (blkcnt < 2 || blksz < 16)
218 		return EINVAL;
219 
220 	bufsize = blksz * blkcnt;
221 
222 	if (bufsize > b->allocsize ||
223 	    bufsize < (b->allocsize >> SNDBUF_CACHE_SHIFT)) {
224 		allocsize = round_page(bufsize);
225 		CHN_UNLOCK(b->channel);
226 		buf = malloc(allocsize, M_DEVBUF, M_WAITOK);
227 		tmpbuf = malloc(allocsize, M_DEVBUF, M_WAITOK);
228 		shadbuf = malloc(allocsize, M_DEVBUF, M_WAITOK);
229 		CHN_LOCK(b->channel);
230 		if (b->buf != NULL)
231 			free(b->buf, M_DEVBUF);
232 		b->buf = buf;
233 		if (b->tmpbuf != NULL)
234 			free(b->tmpbuf, M_DEVBUF);
235 		b->tmpbuf = tmpbuf;
236 		if (b->shadbuf != NULL)
237 			free(b->shadbuf, M_DEVBUF);
238 		b->shadbuf = shadbuf;
239 		if (snd_verbose > 3)
240 			printf("%s(): b=%p %d -> %d [%d]\n",
241 			    __func__, b, b->allocsize, allocsize, bufsize);
242 		b->allocsize = allocsize;
243 	} else if (snd_verbose > 3)
244 		printf("%s(): b=%p %d [%d] NOCHANGE\n",
245 		    __func__, b, b->allocsize, b->bufsize);
246 
247 	b->blkcnt = blkcnt;
248 	b->blksz = blksz;
249 	b->bufsize = bufsize;
250 	b->maxsize = bufsize;
251 	b->sl = bufsize;
252 
253 	sndbuf_reset(b);
254 
255 	return 0;
256 }
257 
258 /**
259  * @brief Zero out space in buffer free area
260  *
261  * This function clears a chunk of @c length bytes in the buffer free area
262  * (i.e., where the next write will be placed).
263  *
264  * @param b		buffer context
265  * @param length	number of bytes to blank
266  */
267 void
268 sndbuf_clear(struct snd_dbuf *b, unsigned int length)
269 {
270 	int i;
271 	u_char data, *p;
272 
273 	if (length == 0)
274 		return;
275 	if (length > b->bufsize)
276 		length = b->bufsize;
277 
278 	data = sndbuf_zerodata(b->fmt);
279 
280 	i = sndbuf_getfreeptr(b);
281 	p = sndbuf_getbuf(b);
282 	while (length > 0) {
283 		p[i] = data;
284 		length--;
285 		i++;
286 		if (i >= b->bufsize)
287 			i = 0;
288 	}
289 }
290 
291 /**
292  * @brief Zap buffer contents, resetting "ready area" fields
293  *
294  * @param b	buffer context
295  */
296 void
297 sndbuf_fillsilence(struct snd_dbuf *b)
298 {
299 	if (b->bufsize > 0)
300 		memset(sndbuf_getbuf(b), sndbuf_zerodata(b->fmt), b->bufsize);
301 	b->rp = 0;
302 	b->rl = b->bufsize;
303 }
304 
305 void
306 sndbuf_fillsilence_rl(struct snd_dbuf *b, u_int rl)
307 {
308 	if (b->bufsize > 0)
309 		memset(sndbuf_getbuf(b), sndbuf_zerodata(b->fmt), b->bufsize);
310 	b->rp = 0;
311 	b->rl = min(b->bufsize, rl);
312 }
313 
314 /**
315  * @brief Reset buffer w/o flushing statistics
316  *
317  * This function just zeroes out buffer contents and sets the "ready length"
318  * to zero.  This was originally to facilitate minimal playback interruption
319  * (i.e., dropped samples) in SNDCTL_DSP_SILENCE/SKIP ioctls.
320  *
321  * @param b	buffer context
322  */
323 void
324 sndbuf_softreset(struct snd_dbuf *b)
325 {
326 	b->rl = 0;
327 	if (b->buf && b->bufsize > 0)
328 		sndbuf_clear(b, b->bufsize);
329 }
330 
331 void
332 sndbuf_reset(struct snd_dbuf *b)
333 {
334 	b->hp = 0;
335 	b->rp = 0;
336 	b->rl = 0;
337 	b->dl = 0;
338 	b->prev_total = 0;
339 	b->total = 0;
340 	b->xrun = 0;
341 	if (b->buf && b->bufsize > 0)
342 		sndbuf_clear(b, b->bufsize);
343 	sndbuf_clearshadow(b);
344 }
345 
346 u_int32_t
347 sndbuf_getfmt(struct snd_dbuf *b)
348 {
349 	return b->fmt;
350 }
351 
352 int
353 sndbuf_setfmt(struct snd_dbuf *b, u_int32_t fmt)
354 {
355 	b->fmt = fmt;
356 	b->bps = AFMT_BPS(b->fmt);
357 	b->align = AFMT_ALIGN(b->fmt);
358 #if 0
359 	b->bps = AFMT_CHANNEL(b->fmt);
360 	if (b->fmt & AFMT_16BIT)
361 		b->bps <<= 1;
362 	else if (b->fmt & AFMT_24BIT)
363 		b->bps *= 3;
364 	else if (b->fmt & AFMT_32BIT)
365 		b->bps <<= 2;
366 #endif
367 	return 0;
368 }
369 
370 unsigned int
371 sndbuf_getspd(struct snd_dbuf *b)
372 {
373 	return b->spd;
374 }
375 
376 void
377 sndbuf_setspd(struct snd_dbuf *b, unsigned int spd)
378 {
379 	b->spd = spd;
380 }
381 
382 unsigned int
383 sndbuf_getalign(struct snd_dbuf *b)
384 {
385 	return (b->align);
386 }
387 
388 unsigned int
389 sndbuf_getblkcnt(struct snd_dbuf *b)
390 {
391 	return b->blkcnt;
392 }
393 
394 void
395 sndbuf_setblkcnt(struct snd_dbuf *b, unsigned int blkcnt)
396 {
397 	b->blkcnt = blkcnt;
398 }
399 
400 unsigned int
401 sndbuf_getblksz(struct snd_dbuf *b)
402 {
403 	return b->blksz;
404 }
405 
406 void
407 sndbuf_setblksz(struct snd_dbuf *b, unsigned int blksz)
408 {
409 	b->blksz = blksz;
410 }
411 
412 unsigned int
413 sndbuf_getbps(struct snd_dbuf *b)
414 {
415 	return b->bps;
416 }
417 
418 void *
419 sndbuf_getbuf(struct snd_dbuf *b)
420 {
421 	return b->buf;
422 }
423 
424 void *
425 sndbuf_getbufofs(struct snd_dbuf *b, unsigned int ofs)
426 {
427 	KASSERT(ofs < b->bufsize, ("%s: ofs invalid %d", __func__, ofs));
428 
429 	return b->buf + ofs;
430 }
431 
432 unsigned int
433 sndbuf_getsize(struct snd_dbuf *b)
434 {
435 	return b->bufsize;
436 }
437 
438 unsigned int
439 sndbuf_getmaxsize(struct snd_dbuf *b)
440 {
441 	return b->maxsize;
442 }
443 
444 unsigned int
445 sndbuf_getallocsize(struct snd_dbuf *b)
446 {
447 	return b->allocsize;
448 }
449 
450 unsigned int
451 sndbuf_runsz(struct snd_dbuf *b)
452 {
453 	return b->dl;
454 }
455 
456 void
457 sndbuf_setrun(struct snd_dbuf *b, int go)
458 {
459 	b->dl = go? b->blksz : 0;
460 }
461 
462 struct selinfo *
463 sndbuf_getsel(struct snd_dbuf *b)
464 {
465 	return &b->sel;
466 }
467 
468 /************************************************************/
469 unsigned int
470 sndbuf_getxrun(struct snd_dbuf *b)
471 {
472 	SNDBUF_LOCKASSERT(b);
473 
474 	return b->xrun;
475 }
476 
477 void
478 sndbuf_setxrun(struct snd_dbuf *b, unsigned int xrun)
479 {
480 	SNDBUF_LOCKASSERT(b);
481 
482 	b->xrun = xrun;
483 }
484 
485 unsigned int
486 sndbuf_gethwptr(struct snd_dbuf *b)
487 {
488 	SNDBUF_LOCKASSERT(b);
489 
490 	return b->hp;
491 }
492 
493 void
494 sndbuf_sethwptr(struct snd_dbuf *b, unsigned int ptr)
495 {
496 	SNDBUF_LOCKASSERT(b);
497 
498 	b->hp = ptr;
499 }
500 
501 unsigned int
502 sndbuf_getready(struct snd_dbuf *b)
503 {
504 	SNDBUF_LOCKASSERT(b);
505 	KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
506 
507 	return b->rl;
508 }
509 
510 unsigned int
511 sndbuf_getreadyptr(struct snd_dbuf *b)
512 {
513 	SNDBUF_LOCKASSERT(b);
514 	KASSERT((b->rp >= 0) && (b->rp <= b->bufsize), ("%s: b->rp invalid %d", __func__, b->rp));
515 
516 	return b->rp;
517 }
518 
519 unsigned int
520 sndbuf_getfree(struct snd_dbuf *b)
521 {
522 	SNDBUF_LOCKASSERT(b);
523 	KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
524 
525 	return b->bufsize - b->rl;
526 }
527 
528 unsigned int
529 sndbuf_getfreeptr(struct snd_dbuf *b)
530 {
531 	SNDBUF_LOCKASSERT(b);
532 	KASSERT((b->rp >= 0) && (b->rp <= b->bufsize), ("%s: b->rp invalid %d", __func__, b->rp));
533 	KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
534 
535 	return (b->rp + b->rl) % b->bufsize;
536 }
537 
538 u_int64_t
539 sndbuf_getblocks(struct snd_dbuf *b)
540 {
541 	SNDBUF_LOCKASSERT(b);
542 
543 	return b->total / b->blksz;
544 }
545 
546 u_int64_t
547 sndbuf_getprevblocks(struct snd_dbuf *b)
548 {
549 	SNDBUF_LOCKASSERT(b);
550 
551 	return b->prev_total / b->blksz;
552 }
553 
554 u_int64_t
555 sndbuf_gettotal(struct snd_dbuf *b)
556 {
557 	SNDBUF_LOCKASSERT(b);
558 
559 	return b->total;
560 }
561 
562 u_int64_t
563 sndbuf_getprevtotal(struct snd_dbuf *b)
564 {
565 	SNDBUF_LOCKASSERT(b);
566 
567 	return b->prev_total;
568 }
569 
570 void
571 sndbuf_updateprevtotal(struct snd_dbuf *b)
572 {
573 	SNDBUF_LOCKASSERT(b);
574 
575 	b->prev_total = b->total;
576 }
577 
578 unsigned int
579 sndbuf_xbytes(unsigned int v, struct snd_dbuf *from, struct snd_dbuf *to)
580 {
581 	if (from == NULL || to == NULL || v == 0)
582 		return 0;
583 
584 	return snd_xbytes(v, sndbuf_getalign(from) * sndbuf_getspd(from),
585 	    sndbuf_getalign(to) * sndbuf_getspd(to));
586 }
587 
588 u_int8_t
589 sndbuf_zerodata(u_int32_t fmt)
590 {
591 	if (fmt & (AFMT_SIGNED | AFMT_PASSTHROUGH))
592 		return (0x00);
593 	else if (fmt & AFMT_MU_LAW)
594 		return (0x7f);
595 	else if (fmt & AFMT_A_LAW)
596 		return (0x55);
597 	return (0x80);
598 }
599 
600 /************************************************************/
601 
602 /**
603  * @brief Acquire buffer space to extend ready area
604  *
605  * This function extends the ready area length by @c count bytes, and may
606  * optionally copy samples from another location stored in @c from.  The
607  * counter @c snd_dbuf::total is also incremented by @c count bytes.
608  *
609  * @param b	audio buffer
610  * @param from	sample source (optional)
611  * @param count	number of bytes to acquire
612  *
613  * @retval 0	Unconditional
614  */
615 int
616 sndbuf_acquire(struct snd_dbuf *b, u_int8_t *from, unsigned int count)
617 {
618 	int l;
619 
620 	KASSERT(count <= sndbuf_getfree(b), ("%s: count %d > free %d", __func__, count, sndbuf_getfree(b)));
621 	KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
622 	b->total += count;
623 	if (from != NULL) {
624 		while (count > 0) {
625 			l = min(count, sndbuf_getsize(b) - sndbuf_getfreeptr(b));
626 			bcopy(from, sndbuf_getbufofs(b, sndbuf_getfreeptr(b)), l);
627 			from += l;
628 			b->rl += l;
629 			count -= l;
630 		}
631 	} else
632 		b->rl += count;
633 	KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d, count %d", __func__, b->rl, count));
634 
635 	return 0;
636 }
637 
638 /**
639  * @brief Dispose samples from channel buffer, increasing size of ready area
640  *
641  * This function discards samples from the supplied buffer by advancing the
642  * ready area start pointer and decrementing the ready area length.  If
643  * @c to is not NULL, then the discard samples will be copied to the location
644  * it points to.
645  *
646  * @param b	PCM channel sound buffer
647  * @param to	destination buffer (optional)
648  * @param count	number of bytes to discard
649  *
650  * @returns 0 unconditionally
651  */
652 int
653 sndbuf_dispose(struct snd_dbuf *b, u_int8_t *to, unsigned int count)
654 {
655 	int l;
656 
657 	KASSERT(count <= sndbuf_getready(b), ("%s: count %d > ready %d", __func__, count, sndbuf_getready(b)));
658 	KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d", __func__, b->rl));
659 	if (to != NULL) {
660 		while (count > 0) {
661 			l = min(count, sndbuf_getsize(b) - sndbuf_getreadyptr(b));
662 			bcopy(sndbuf_getbufofs(b, sndbuf_getreadyptr(b)), to, l);
663 			to += l;
664 			b->rl -= l;
665 			b->rp = (b->rp + l) % b->bufsize;
666 			count -= l;
667 		}
668 	} else {
669 		b->rl -= count;
670 		b->rp = (b->rp + count) % b->bufsize;
671 	}
672 	KASSERT((b->rl >= 0) && (b->rl <= b->bufsize), ("%s: b->rl invalid %d, count %d", __func__, b->rl, count));
673 
674 	return 0;
675 }
676 
677 #ifdef SND_DIAGNOSTIC
678 static uint32_t snd_feeder_maxfeed = 0;
679 SYSCTL_UINT(_hw_snd, OID_AUTO, feeder_maxfeed, CTLFLAG_RD,
680     &snd_feeder_maxfeed, 0, "maximum feeder count request");
681 
682 static uint32_t snd_feeder_maxcycle = 0;
683 SYSCTL_UINT(_hw_snd, OID_AUTO, feeder_maxcycle, CTLFLAG_RD,
684     &snd_feeder_maxcycle, 0, "maximum feeder cycle");
685 #endif
686 
687 /* count is number of bytes we want added to destination buffer */
688 int
689 sndbuf_feed(struct snd_dbuf *from, struct snd_dbuf *to, struct pcm_channel *channel, struct pcm_feeder *feeder, unsigned int count)
690 {
691 	unsigned int cnt, maxfeed;
692 #ifdef SND_DIAGNOSTIC
693 	unsigned int cycle;
694 
695 	if (count > snd_feeder_maxfeed)
696 		snd_feeder_maxfeed = count;
697 
698 	cycle = 0;
699 #endif
700 
701 	KASSERT(count > 0, ("can't feed 0 bytes"));
702 
703 	if (sndbuf_getfree(to) < count)
704 		return (EINVAL);
705 
706 	maxfeed = SND_FXROUND(SND_FXDIV_MAX, sndbuf_getalign(to));
707 
708 	do {
709 		cnt = FEEDER_FEED(feeder, channel, to->tmpbuf,
710 		    min(count, maxfeed), from);
711 		if (cnt == 0)
712 			break;
713 		sndbuf_acquire(to, to->tmpbuf, cnt);
714 		count -= cnt;
715 #ifdef SND_DIAGNOSTIC
716 		cycle++;
717 #endif
718 	} while (count != 0);
719 
720 #ifdef SND_DIAGNOSTIC
721 	if (cycle > snd_feeder_maxcycle)
722 		snd_feeder_maxcycle = cycle;
723 #endif
724 
725 	return (0);
726 }
727 
728 /************************************************************/
729 
730 void
731 sndbuf_dump(struct snd_dbuf *b, char *s, u_int32_t what)
732 {
733 	printf("%s: [", s);
734 	if (what & 0x01)
735 		printf(" bufsize: %d, maxsize: %d", b->bufsize, b->maxsize);
736 	if (what & 0x02)
737 		printf(" dl: %d, rp: %d, rl: %d, hp: %d", b->dl, b->rp, b->rl, b->hp);
738 	if (what & 0x04)
739 		printf(" total: %ju, prev_total: %ju, xrun: %d", (uintmax_t)b->total, (uintmax_t)b->prev_total, b->xrun);
740    	if (what & 0x08)
741 		printf(" fmt: 0x%x, spd: %d", b->fmt, b->spd);
742 	if (what & 0x10)
743 		printf(" blksz: %d, blkcnt: %d, flags: 0x%x", b->blksz, b->blkcnt, b->flags);
744 	printf(" ]\n");
745 }
746 
747 /************************************************************/
748 u_int32_t
749 sndbuf_getflags(struct snd_dbuf *b)
750 {
751 	return b->flags;
752 }
753 
754 void
755 sndbuf_setflags(struct snd_dbuf *b, u_int32_t flags, int on)
756 {
757 	b->flags &= ~flags;
758 	if (on)
759 		b->flags |= flags;
760 }
761 
762 /**
763  * @brief Clear the shadow buffer by filling with samples equal to zero.
764  *
765  * @param b buffer to clear
766  */
767 void
768 sndbuf_clearshadow(struct snd_dbuf *b)
769 {
770 	KASSERT(b != NULL, ("b is a null pointer"));
771 	KASSERT(b->sl >= 0, ("illegal shadow length"));
772 
773 	if ((b->shadbuf != NULL) && (b->sl > 0))
774 		memset(b->shadbuf, sndbuf_zerodata(b->fmt), b->sl);
775 }
776 
777 #ifdef OSSV4_EXPERIMENT
778 /**
779  * @brief Return peak value from samples in buffer ready area.
780  *
781  * Peak ranges from 0-32767.  If channel is monaural, most significant 16
782  * bits will be zero.  For now, only expects to work with 1-2 channel
783  * buffers.
784  *
785  * @note  Currently only operates with linear PCM formats.
786  *
787  * @param b buffer to analyze
788  * @param lpeak pointer to store left peak value
789  * @param rpeak pointer to store right peak value
790  */
791 void
792 sndbuf_getpeaks(struct snd_dbuf *b, int *lp, int *rp)
793 {
794 	u_int32_t lpeak, rpeak;
795 
796 	lpeak = 0;
797 	rpeak = 0;
798 
799 	/**
800 	 * @todo fill this in later
801 	 */
802 }
803 #endif
804