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 EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
 124
 125 #ifdef CONFIG_SND_VERBOSE_PROCFS
 126 /*
 127  * read callback for prealloc proc file
 128  *
 129  * prints the current allocated size in kB.
 130  */
 131 static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
 132                                               struct snd_info_buffer *buffer)
 133 {
 134         struct snd_pcm_substream *substream = entry->private_data;
 135         snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
 136 }
 137
 138 /*
 139  * read callback for prealloc_max proc file
 140  *
 141  * prints the maximum allowed size in kB.
 142  */
 143 static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
 144                                                   struct snd_info_buffer *buffer)
 145 {
 146         struct snd_pcm_substream *substream = entry->private_data;
 147         snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
 148 }
 149
 150 /*
 151  * write callback for prealloc proc file
 152  *
 153  * accepts the preallocation size in kB.
 154  */
 155 static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
 156                                                struct snd_info_buffer *buffer)
 157 {
 158         struct snd_pcm_substream *substream = entry->private_data;
 159         char line[64], str[64];
 160         size_t size;
 161         struct snd_dma_buffer new_dmab;
 162
 163         if (substream->runtime) {
 164                 buffer->error = -EBUSY;
 165                 return;
 166         }
 167         if (!snd_info_get_line(buffer, line, sizeof(line))) {
 168                 snd_info_get_str(str, line, sizeof(str));
 169                 size = simple_strtoul(str, NULL, 10) * 1024;
 170                 if ((size != 0 && size < 8192) || size > substream->dma_max) {
 171                         buffer->error = -EINVAL;
 172                         return;
 173                 }
 174                 if (substream->dma_buffer.bytes == size)
 175                         return;
 176                 memset(&new_dmab, 0, sizeof(new_dmab));
 177                 new_dmab.dev = substream->dma_buffer.dev;
 178                 if (size > 0) {
 179                         if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
 180                                                 substream->dma_buffer.dev.dev,
 181                                                 size, &new_dmab) < 0) {
 182                                 buffer->error = -ENOMEM;
 183                                 return;
 184                         }
 185                         substream->buffer_bytes_max = size;
 186                 } else {
 187                         substream->buffer_bytes_max = UINT_MAX;
 188                 }
 189                 if (substream->dma_buffer.area)
 190                         snd_dma_free_pages(&substream->dma_buffer);
 191                 substream->dma_buffer = new_dmab;
 192         } else {
 193                 buffer->error = -EINVAL;
 194         }
 195 }
 196
 197 static inline void preallocate_info_init(struct snd_pcm_substream *substream)
 198 {
 199         struct snd_info_entry *entry;
 200
 201         if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
 202                 entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
 203                 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
 204                 entry->mode |= S_IWUSR;
 205                 entry->private_data = substream;
 206                 if (snd_info_register(entry) < 0) {
 207                         snd_info_free_entry(entry);
 208                         entry = NULL;
 209                 }
 210         }
 211         substream->proc_prealloc_entry = entry;
 212         if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
 213                 entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
 214                 entry->private_data = substream;
 215                 if (snd_info_register(entry) < 0) {
 216                         snd_info_free_entry(entry);
 217                         entry = NULL;
 218                 }
 219         }
 220         substream->proc_prealloc_max_entry = entry;
 221 }
 222
 223 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 224 #define preallocate_info_init(s)
 225 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 226
 227 /*
 228  * pre-allocate the buffer and create a proc file for the substream
 229  */
 230 static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
 231                                           size_t size, size_t max)
 232 {
 233
 234         if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
 235                 preallocate_pcm_pages(substream, size);
 236
 237         if (substream->dma_buffer.bytes > 0)
 238                 substream->buffer_bytes_max = substream->dma_buffer.bytes;
 239         substream->dma_max = max;
 240         preallocate_info_init(substream);
 241         return 0;
 242 }
 243
 244
 245 /**
 246  * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
 247  * @substream: the pcm substream instance
 248  * @type: DMA type (SNDRV_DMA_TYPE_*)
 249  * @data: DMA type dependent data
 250  * @size: the requested pre-allocation size in bytes
 251  * @max: the max. allowed pre-allocation size
 252  *
 253  * Do pre-allocation for the given DMA buffer type.
 254  *
 255  * Return: Zero if successful, or a negative error code on failure.
 256  */
 257 int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
 258                                   int type, struct device *data,
 259                                   size_t size, size_t max)
 260 {
 261         substream->dma_buffer.dev.type = type;
 262         substream->dma_buffer.dev.dev = data;
 263         return snd_pcm_lib_preallocate_pages1(substream, size, max);
 264 }
 265 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
 266
 267 /**
 268  * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
 269  * @pcm: the pcm instance
 270  * @type: DMA type (SNDRV_DMA_TYPE_*)
 271  * @data: DMA type dependent data
 272  * @size: the requested pre-allocation size in bytes
 273  * @max: the max. allowed pre-allocation size
 274  *
 275  * Do pre-allocation to all substreams of the given pcm for the
 276  * specified DMA type.
 277  *
 278  * Return: Zero if successful, or a negative error code on failure.
 279  */
 280 int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
 281                                           int type, void *data,
 282                                           size_t size, size_t max)
 283 {
 284         struct snd_pcm_substream *substream;
 285         int stream, err;
 286
 287         for (stream = 0; stream < 2; stream++)
 288                 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
 289                         if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
 290                                 return err;
 291         return 0;
 292 }
 293 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
 294
 295 #ifdef CONFIG_SND_DMA_SGBUF
 296 /**
 297  * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
 298  * @substream: the pcm substream instance
 299  * @offset: the buffer offset
 300  *
 301  * Used as the page callback of PCM ops.
 302  *
 303  * Return: The page struct at the given buffer offset. %NULL on failure.
 304  */
 305 struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
 306 {
 307         struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
 308
 309         unsigned int idx = offset >> PAGE_SHIFT;
 310         if (idx >= (unsigned int)sgbuf->pages)
 311                 return NULL;
 312         return sgbuf->page_table[idx];
 313 }
 314 EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
 315 #endif /* CONFIG_SND_DMA_SGBUF */
 316
 317 /**
 318  * snd_pcm_lib_malloc_pages - allocate the DMA buffer
 319  * @substream: the substream to allocate the DMA buffer to
 320  * @size: the requested buffer size in bytes
 321  *
 322  * Allocates the DMA buffer on the BUS type given earlier to
 323  * snd_pcm_lib_preallocate_xxx_pages().
 324  *
 325  * Return: 1 if the buffer is changed, 0 if not changed, or a negative
 326  * code on failure.
 327  */
 328 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
 329 {
 330         struct snd_pcm_runtime *runtime;
 331         struct snd_dma_buffer *dmab = NULL;
 332
 333         if (PCM_RUNTIME_CHECK(substream))
 334                 return -EINVAL;
 335         if (snd_BUG_ON(substream->dma_buffer.dev.type ==
 336                        SNDRV_DMA_TYPE_UNKNOWN))
 337                 return -EINVAL;
 338         runtime = substream->runtime;
 339
 340         if (runtime->dma_buffer_p) {
 341                 /* perphaps, we might free the large DMA memory region
 342                    to save some space here, but the actual solution
 343                    costs us less time */
 344                 if (runtime->dma_buffer_p->bytes >= size) {
 345                         runtime->dma_bytes = size;
 346                         return 0;       /* ok, do not change */
 347                 }
 348                 snd_pcm_lib_free_pages(substream);
 349         }
 350         if (substream->dma_buffer.area != NULL &&
 351             substream->dma_buffer.bytes >= size) {
 352                 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
 353         } else {
 354                 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
 355                 if (! dmab)
 356                         return -ENOMEM;
 357                 dmab->dev = substream->dma_buffer.dev;
 358                 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
 359                                         substream->dma_buffer.dev.dev,
 360                                         size, dmab) < 0) {
 361                         kfree(dmab);
 362                         return -ENOMEM;
 363                 }
 364         }
 365         snd_pcm_set_runtime_buffer(substream, dmab);
 366         runtime->dma_bytes = size;
 367         return 1;                       /* area was changed */
 368 }
 369 EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
 370
 371 /**
 372  * snd_pcm_lib_free_pages - release the allocated DMA buffer.
 373  * @substream: the substream to release the DMA buffer
 374  *
 375  * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
 376  *
 377  * Return: Zero if successful, or a negative error code on failure.
 378  */
 379 int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
 380 {
 381         struct snd_pcm_runtime *runtime;
 382
 383         if (PCM_RUNTIME_CHECK(substream))
 384                 return -EINVAL;
 385         runtime = substream->runtime;
 386         if (runtime->dma_area == NULL)
 387                 return 0;
 388         if (runtime->dma_buffer_p != &substream->dma_buffer) {
 389                 /* it's a newly allocated buffer.  release it now. */
 390                 snd_dma_free_pages(runtime->dma_buffer_p);
 391                 kfree(runtime->dma_buffer_p);
 392         }
 393         snd_pcm_set_runtime_buffer(substream, NULL);
 394         return 0;
 395 }
 396 EXPORT_SYMBOL(snd_pcm_lib_free_pages);
 397
 398 int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
 399                                       size_t size, gfp_t gfp_flags)
 400 {
 401         struct snd_pcm_runtime *runtime;
 402
 403         if (PCM_RUNTIME_CHECK(substream))
 404                 return -EINVAL;
 405         runtime = substream->runtime;
 406         if (runtime->dma_area) {
 407                 if (runtime->dma_bytes >= size)
 408                         return 0; /* already large enough */
 409                 vfree(runtime->dma_area);
 410         }
 411         runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
 412         if (!runtime->dma_area)
 413                 return -ENOMEM;
 414         runtime->dma_bytes = size;
 415         return 1;
 416 }
 417 EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
 418
 419 /**
 420  * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
 421  * @substream: the substream with a buffer allocated by
 422  *      snd_pcm_lib_alloc_vmalloc_buffer()
 423  *
 424  * Return: Zero if successful, or a negative error code on failure.
 425  */
 426 int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
 427 {
 428         struct snd_pcm_runtime *runtime;
 429
 430         if (PCM_RUNTIME_CHECK(substream))
 431                 return -EINVAL;
 432         runtime = substream->runtime;
 433         vfree(runtime->dma_area);
 434         runtime->dma_area = NULL;
 435         return 0;
 436 }
 437 EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
 438
 439 /**
 440  * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
 441  * @substream: the substream with a buffer allocated by
 442  *      snd_pcm_lib_alloc_vmalloc_buffer()
 443  * @offset: offset in the buffer
 444  *
 445  * This function is to be used as the page callback in the PCM ops.
 446  *
 447  * Return: The page struct, or %NULL on failure.
 448  */
 449 struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
 450                                           unsigned long offset)
 451 {
 452         return vmalloc_to_page(substream->runtime->dma_area + offset);
 453 }
 454 EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);