sound/core/pcm_memory.c

   1 /*
   2  *  Digital Audio (PCM) abstract layer
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <linux/io.h>
  23 #include <linux/time.h>
  24 #include <linux/init.h>
  25 #include <linux/slab.h>
  26 #include <linux/moduleparam.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/export.h>
  29 #include <sound/core.h>
  30 #include <sound/pcm.h>
  31 #include <sound/info.h>
  32 #include <sound/initval.h>
  33
  34 static int preallocate_dma = 1;
  35 module_param(preallocate_dma, int, 0444);
  36 MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
  37
  38 static int maximum_substreams = 4;
  39 module_param(maximum_substreams, int, 0444);
  40 MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
  41
  42 static const size_t snd_minimum_buffer = 16384;
  43
  44
  45 /*
  46  * try to allocate as the large pages as possible.
  47  * stores the resultant memory size in *res_size.
  48  *
  49  * the minimum size is snd_minimum_buffer.  it should be power of 2.
  50  */
  51 static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
  52 {
  53         struct snd_dma_buffer *dmab = &substream->dma_buffer;
  54         size_t orig_size = size;
  55         int err;
  56
  57         do {
  58                 if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
  59                                                size, dmab)) < 0) {
  60                         if (err != -ENOMEM)
  61                                 return err; /* fatal error */
  62                 } else
  63                         return 0;
  64                 size >>= 1;
  65         } while (size >= snd_minimum_buffer);
  66         dmab->bytes = 0; /* tell error */
  67         pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n",
  68                 substream->pcm->card->number, substream->pcm->device,
  69                 substream->stream ? 'c' : 'p', substream->number,
  70                 substream->pcm->name, orig_size);
  71         return 0;
  72 }
  73
  74 /*
  75  * release the preallocated buffer if not yet done.
  76  */
  77 static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
  78 {
  79         if (substream->dma_buffer.area == NULL)
  80                 return;
  81         snd_dma_free_pages(&substream->dma_buffer);
  82         substream->dma_buffer.area = NULL;
  83 }
  84
  85 /**
  86  * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
  87  * @substream: the pcm substream instance
  88  *
  89  * Releases the pre-allocated buffer of the given substream.
  90  *
  91  * Return: Zero if successful, or a negative error code on failure.
  92  */
  93 int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
  94 {
  95         snd_pcm_lib_preallocate_dma_free(substream);
  96 #ifdef CONFIG_SND_VERBOSE_PROCFS
  97         snd_info_free_entry(substream->proc_prealloc_max_entry);
  98         substream->proc_prealloc_max_entry = NULL;
  99         snd_info_free_entry(substream->proc_prealloc_entry);
 100         substream->proc_prealloc_entry = NULL;
 101 #endif
 102         return 0;
 103 }
 104
 105 /**
 106  * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
 107  * @pcm: the pcm instance
 108  *
 109  * Releases all the pre-allocated buffers on the given pcm.
 110  *
 111  * Return: Zero if successful, or a negative error code on failure.
 112  */
 113 int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
 114 {
 115         struct snd_pcm_substream *substream;
 116         int stream;
 117
 118         for (stream = 0; stream < 2; stream++)
 119                 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
 120                         snd_pcm_lib_preallocate_free(substream);
 121         return 0;
 122 }
 123
 124 EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
 125
 126 #ifdef CONFIG_SND_VERBOSE_PROCFS
 127 /*
 128  * read callback for prealloc proc file
 129  *
 130  * prints the current allocated size in kB.
 131  */
 132 static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
 133                                               struct snd_info_buffer *buffer)
 134 {
 135         struct snd_pcm_substream *substream = entry->private_data;
 136         snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
 137 }
 138
 139 /*
 140  * read callback for prealloc_max proc file
 141  *
 142  * prints the maximum allowed size in kB.
 143  */
 144 static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
 145                                                   struct snd_info_buffer *buffer)
 146 {
 147         struct snd_pcm_substream *substream = entry->private_data;
 148         snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
 149 }
 150
 151 /*
 152  * write callback for prealloc proc file
 153  *
 154  * accepts the preallocation size in kB.
 155  */
 156 static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
 157                                                struct snd_info_buffer *buffer)
 158 {
 159         struct snd_pcm_substream *substream = entry->private_data;
 160         char line[64], str[64];
 161         size_t size;
 162         struct snd_dma_buffer new_dmab;
 163
 164         if (substream->runtime) {
 165                 buffer->error = -EBUSY;
 166                 return;
 167         }
 168         if (!snd_info_get_line(buffer, line, sizeof(line))) {
 169                 snd_info_get_str(str, line, sizeof(str));
 170                 size = simple_strtoul(str, NULL, 10) * 1024;
 171                 if ((size != 0 && size < 8192) || size > substream->dma_max) {
 172                         buffer->error = -EINVAL;
 173                         return;
 174                 }
 175                 if (substream->dma_buffer.bytes == size)
 176                         return;
 177                 memset(&new_dmab, 0, sizeof(new_dmab));
 178                 new_dmab.dev = substream->dma_buffer.dev;
 179                 if (size > 0) {
 180                         if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
 181                                                 substream->dma_buffer.dev.dev,
 182                                                 size, &new_dmab) < 0) {
 183                                 buffer->error = -ENOMEM;
 184                                 return;
 185                         }
 186                         substream->buffer_bytes_max = size;
 187                 } else {
 188                         substream->buffer_bytes_max = UINT_MAX;
 189                 }
 190                 if (substream->dma_buffer.area)
 191                         snd_dma_free_pages(&substream->dma_buffer);
 192                 substream->dma_buffer = new_dmab;
 193         } else {
 194                 buffer->error = -EINVAL;
 195         }
 196 }
 197
 198 static inline void preallocate_info_init(struct snd_pcm_substream *substream)
 199 {
 200         struct snd_info_entry *entry;
 201
 202         if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
 203                 entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
 204                 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
 205                 entry->mode |= S_IWUSR;
 206                 entry->private_data = substream;
 207                 if (snd_info_register(entry) < 0) {
 208                         snd_info_free_entry(entry);
 209                         entry = NULL;
 210                 }
 211         }
 212         substream->proc_prealloc_entry = entry;
 213         if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
 214                 entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
 215                 entry->private_data = substream;
 216                 if (snd_info_register(entry) < 0) {
 217                         snd_info_free_entry(entry);
 218                         entry = NULL;
 219                 }
 220         }
 221         substream->proc_prealloc_max_entry = entry;
 222 }
 223
 224 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 225 #define preallocate_info_init(s)
 226 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 227
 228 /*
 229  * pre-allocate the buffer and create a proc file for the substream
 230  */
 231 static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
 232                                           size_t size, size_t max)
 233 {
 234
 235         if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
 236                 preallocate_pcm_pages(substream, size);
 237
 238         if (substream->dma_buffer.bytes > 0)
 239                 substream->buffer_bytes_max = substream->dma_buffer.bytes;
 240         substream->dma_max = max;
 241         preallocate_info_init(substream);
 242         return 0;
 243 }
 244
 245
 246 /**
 247  * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
 248  * @substream: the pcm substream instance
 249  * @type: DMA type (SNDRV_DMA_TYPE_*)
 250  * @data: DMA type dependent data
 251  * @size: the requested pre-allocation size in bytes
 252  * @max: the max. allowed pre-allocation size
 253  *
 254  * Do pre-allocation for the given DMA buffer type.
 255  *
 256  * Return: Zero if successful, or a negative error code on failure.
 257  */
 258 int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
 259                                   int type, struct device *data,
 260                                   size_t size, size_t max)
 261 {
 262         substream->dma_buffer.dev.type = type;
 263         substream->dma_buffer.dev.dev = data;
 264         return snd_pcm_lib_preallocate_pages1(substream, size, max);
 265 }
 266
 267 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
 268
 269 /**
 270  * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
 271  * @pcm: the pcm instance
 272  * @type: DMA type (SNDRV_DMA_TYPE_*)
 273  * @data: DMA type dependent data
 274  * @size: the requested pre-allocation size in bytes
 275  * @max: the max. allowed pre-allocation size
 276  *
 277  * Do pre-allocation to all substreams of the given pcm for the
 278  * specified DMA type.
 279  *
 280  * Return: Zero if successful, or a negative error code on failure.
 281  */
 282 int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
 283                                           int type, void *data,
 284                                           size_t size, size_t max)
 285 {
 286         struct snd_pcm_substream *substream;
 287         int stream, err;
 288
 289         for (stream = 0; stream < 2; stream++)
 290                 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
 291                         if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
 292                                 return err;
 293         return 0;
 294 }
 295
 296 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
 297
 298 #ifdef CONFIG_SND_DMA_SGBUF
 299 /**
 300  * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
 301  * @substream: the pcm substream instance
 302  * @offset: the buffer offset
 303  *
 304  * Used as the page callback of PCM ops.
 305  *
 306  * Return: The page struct at the given buffer offset. %NULL on failure.
 307  */
 308 struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
 309 {
 310         struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
 311
 312         unsigned int idx = offset >> PAGE_SHIFT;
 313         if (idx >= (unsigned int)sgbuf->pages)
 314                 return NULL;
 315         return sgbuf->page_table[idx];
 316 }
 317
 318 EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
 319 #endif /* CONFIG_SND_DMA_SGBUF */
 320
 321 /**
 322  * snd_pcm_lib_malloc_pages - allocate the DMA buffer
 323  * @substream: the substream to allocate the DMA buffer to
 324  * @size: the requested buffer size in bytes
 325  *
 326  * Allocates the DMA buffer on the BUS type given earlier to
 327  * snd_pcm_lib_preallocate_xxx_pages().
 328  *
 329  * Return: 1 if the buffer is changed, 0 if not changed, or a negative
 330  * code on failure.
 331  */
 332 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
 333 {
 334         struct snd_pcm_runtime *runtime;
 335         struct snd_dma_buffer *dmab = NULL;
 336
 337         if (PCM_RUNTIME_CHECK(substream))
 338                 return -EINVAL;
 339         if (snd_BUG_ON(substream->dma_buffer.dev.type ==
 340                        SNDRV_DMA_TYPE_UNKNOWN))
 341                 return -EINVAL;
 342         runtime = substream->runtime;
 343
 344         if (runtime->dma_buffer_p) {
 345                 /* perphaps, we might free the large DMA memory region
 346                    to save some space here, but the actual solution
 347                    costs us less time */
 348                 if (runtime->dma_buffer_p->bytes >= size) {
 349                         runtime->dma_bytes = size;
 350                         return 0;       /* ok, do not change */
 351                 }
 352                 snd_pcm_lib_free_pages(substream);
 353         }
 354         if (substream->dma_buffer.area != NULL &&
 355             substream->dma_buffer.bytes >= size) {
 356                 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
 357         } else {
 358                 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
 359                 if (! dmab)
 360                         return -ENOMEM;
 361                 dmab->dev = substream->dma_buffer.dev;
 362                 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
 363                                         substream->dma_buffer.dev.dev,
 364                                         size, dmab) < 0) {
 365                         kfree(dmab);
 366                         return -ENOMEM;
 367                 }
 368         }
 369         snd_pcm_set_runtime_buffer(substream, dmab);
 370         runtime->dma_bytes = size;
 371         return 1;                       /* area was changed */
 372 }
 373
 374 EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
 375
 376 /**
 377  * snd_pcm_lib_free_pages - release the allocated DMA buffer.
 378  * @substream: the substream to release the DMA buffer
 379  *
 380  * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
 381  *
 382  * Return: Zero if successful, or a negative error code on failure.
 383  */
 384 int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
 385 {
 386         struct snd_pcm_runtime *runtime;
 387
 388         if (PCM_RUNTIME_CHECK(substream))
 389                 return -EINVAL;
 390         runtime = substream->runtime;
 391         if (runtime->dma_area == NULL)
 392                 return 0;
 393         if (runtime->dma_buffer_p != &substream->dma_buffer) {
 394                 /* it's a newly allocated buffer.  release it now. */
 395                 snd_dma_free_pages(runtime->dma_buffer_p);
 396                 kfree(runtime->dma_buffer_p);
 397         }
 398         snd_pcm_set_runtime_buffer(substream, NULL);
 399         return 0;
 400 }
 401
 402 EXPORT_SYMBOL(snd_pcm_lib_free_pages);
 403
 404 int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
 405                                       size_t size, gfp_t gfp_flags)
 406 {
 407         struct snd_pcm_runtime *runtime;
 408
 409         if (PCM_RUNTIME_CHECK(substream))
 410                 return -EINVAL;
 411         runtime = substream->runtime;
 412         if (runtime->dma_area) {
 413                 if (runtime->dma_bytes >= size)
 414                         return 0; /* already large enough */
 415                 vfree(runtime->dma_area);
 416         }
 417         runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
 418         if (!runtime->dma_area)
 419                 return -ENOMEM;
 420         runtime->dma_bytes = size;
 421         return 1;
 422 }
 423 EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
 424
 425 /**
 426  * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
 427  * @substream: the substream with a buffer allocated by
 428  *      snd_pcm_lib_alloc_vmalloc_buffer()
 429  *
 430  * Return: Zero if successful, or a negative error code on failure.
 431  */
 432 int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
 433 {
 434         struct snd_pcm_runtime *runtime;
 435
 436         if (PCM_RUNTIME_CHECK(substream))
 437                 return -EINVAL;
 438         runtime = substream->runtime;
 439         vfree(runtime->dma_area);
 440         runtime->dma_area = NULL;
 441         return 0;
 442 }
 443 EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
 444
 445 /**
 446  * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
 447  * @substream: the substream with a buffer allocated by
 448  *      snd_pcm_lib_alloc_vmalloc_buffer()
 449  * @offset: offset in the buffer
 450  *
 451  * This function is to be used as the page callback in the PCM ops.
 452  *
 453  * Return: The page struct, or %NULL on failure.
 454  */
 455 struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
 456                                           unsigned long offset)
 457 {
 458         return vmalloc_to_page(substream->runtime->dma_area + offset);
 459 }
 460 EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);