The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/dev/sound/pcm/buffer.c

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    1 /*-
    2  * Copyright (c) 2005-2009 Ariff Abdullah <ariff@FreeBSD.org>
    3  * Portions Copyright (c) Ryan Beasley <ryan.beasley@gmail.com> - GSoC 2006
    4  * Copyright (c) 1999 Cameron Grant <cg@FreeBSD.org>
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  *
   16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   26  * SUCH DAMAGE.
   27  */
   28 
   29 #ifdef HAVE_KERNEL_OPTION_HEADERS
   30 #include "opt_snd.h"
   31 #endif
   32 
   33 #include <dev/sound/pcm/sound.h>
   34 
   35 #include "feeder_if.h"
   36 
   37 #define SND_USE_FXDIV
   38 #define SND_DECLARE_FXDIV
   39 #include "snd_fxdiv_gen.h"
   40 
   41 SND_DECLARE_FILE("$FreeBSD: stable/11/sys/dev/sound/pcm/buffer.c 331722 2018-03-29 02:50:57Z eadler $");
   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, 0) != 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

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