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 void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
  92 {
  93         snd_pcm_lib_preallocate_dma_free(substream);
  94 }
  95
  96 /**
  97  * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
  98  * @pcm: the pcm instance
  99  *
 100  * Releases all the pre-allocated buffers on the given pcm.
 101  */
 102 void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
 103 {
 104         struct snd_pcm_substream *substream;
 105         int stream;
 106
 107         for (stream = 0; stream < 2; stream++)
 108                 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
 109                         snd_pcm_lib_preallocate_free(substream);
 110 }
 111 EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
 112
 113 #ifdef CONFIG_SND_VERBOSE_PROCFS
 114 /*
 115  * read callback for prealloc proc file
 116  *
 117  * prints the current allocated size in kB.
 118  */
 119 static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
 120                                               struct snd_info_buffer *buffer)
 121 {
 122         struct snd_pcm_substream *substream = entry->private_data;
 123         snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
 124 }
 125
 126 /*
 127  * read callback for prealloc_max proc file
 128  *
 129  * prints the maximum allowed size in kB.
 130  */
 131 static void snd_pcm_lib_preallocate_max_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_max / 1024);
 136 }
 137
 138 /*
 139  * write callback for prealloc proc file
 140  *
 141  * accepts the preallocation size in kB.
 142  */
 143 static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
 144                                                struct snd_info_buffer *buffer)
 145 {
 146         struct snd_pcm_substream *substream = entry->private_data;
 147         char line[64], str[64];
 148         size_t size;
 149         struct snd_dma_buffer new_dmab;
 150
 151         if (substream->runtime) {
 152                 buffer->error = -EBUSY;
 153                 return;
 154         }
 155         if (!snd_info_get_line(buffer, line, sizeof(line))) {
 156                 snd_info_get_str(str, line, sizeof(str));
 157                 size = simple_strtoul(str, NULL, 10) * 1024;
 158                 if ((size != 0 && size < 8192) || size > substream->dma_max) {
 159                         buffer->error = -EINVAL;
 160                         return;
 161                 }
 162                 if (substream->dma_buffer.bytes == size)
 163                         return;
 164                 memset(&new_dmab, 0, sizeof(new_dmab));
 165                 new_dmab.dev = substream->dma_buffer.dev;
 166                 if (size > 0) {
 167                         if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
 168                                                 substream->dma_buffer.dev.dev,
 169                                                 size, &new_dmab) < 0) {
 170                                 buffer->error = -ENOMEM;
 171                                 return;
 172                         }
 173                         substream->buffer_bytes_max = size;
 174                 } else {
 175                         substream->buffer_bytes_max = UINT_MAX;
 176                 }
 177                 if (substream->dma_buffer.area)
 178                         snd_dma_free_pages(&substream->dma_buffer);
 179                 substream->dma_buffer = new_dmab;
 180         } else {
 181                 buffer->error = -EINVAL;
 182         }
 183 }
 184
 185 static inline void preallocate_info_init(struct snd_pcm_substream *substream)
 186 {
 187         struct snd_info_entry *entry;
 188
 189         entry = snd_info_create_card_entry(substream->pcm->card, "prealloc",
 190                                            substream->proc_root);
 191         if (entry) {
 192                 snd_info_set_text_ops(entry, substream,
 193                                       snd_pcm_lib_preallocate_proc_read);
 194                 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
 195                 entry->mode |= 0200;
 196         }
 197         entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max",
 198                                            substream->proc_root);
 199         if (entry)
 200                 snd_info_set_text_ops(entry, substream,
 201                                       snd_pcm_lib_preallocate_max_proc_read);
 202 }
 203
 204 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 205 #define preallocate_info_init(s)
 206 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 207
 208 /*
 209  * pre-allocate the buffer and create a proc file for the substream
 210  */
 211 static void snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
 212                                           size_t size, size_t max)
 213 {
 214
 215         if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
 216                 preallocate_pcm_pages(substream, size);
 217
 218         if (substream->dma_buffer.bytes > 0)
 219                 substream->buffer_bytes_max = substream->dma_buffer.bytes;
 220         substream->dma_max = max;
 221         preallocate_info_init(substream);
 222 }
 223
 224
 225 /**
 226  * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
 227  * @substream: the pcm substream instance
 228  * @type: DMA type (SNDRV_DMA_TYPE_*)
 229  * @data: DMA type dependent data
 230  * @size: the requested pre-allocation size in bytes
 231  * @max: the max. allowed pre-allocation size
 232  *
 233  * Do pre-allocation for the given DMA buffer type.
 234  */
 235 void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
 236                                   int type, struct device *data,
 237                                   size_t size, size_t max)
 238 {
 239         substream->dma_buffer.dev.type = type;
 240         substream->dma_buffer.dev.dev = data;
 241         snd_pcm_lib_preallocate_pages1(substream, size, max);
 242 }
 243 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
 244
 245 /**
 246  * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
 247  * @pcm: the pcm 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 to all substreams of the given pcm for the
 254  * specified DMA type.
 255  */
 256 void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
 257                                           int type, void *data,
 258                                           size_t size, size_t max)
 259 {
 260         struct snd_pcm_substream *substream;
 261         int stream;
 262
 263         for (stream = 0; stream < 2; stream++)
 264                 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
 265                         snd_pcm_lib_preallocate_pages(substream, type, data, size, max);
 266 }
 267 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
 268
 269 #ifdef CONFIG_SND_DMA_SGBUF
 270 /**
 271  * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
 272  * @substream: the pcm substream instance
 273  * @offset: the buffer offset
 274  *
 275  * Used as the page callback of PCM ops.
 276  *
 277  * Return: The page struct at the given buffer offset. %NULL on failure.
 278  */
 279 struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
 280 {
 281         struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
 282
 283         unsigned int idx = offset >> PAGE_SHIFT;
 284         if (idx >= (unsigned int)sgbuf->pages)
 285                 return NULL;
 286         return sgbuf->page_table[idx];
 287 }
 288 EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
 289 #endif /* CONFIG_SND_DMA_SGBUF */
 290
 291 /**
 292  * snd_pcm_lib_malloc_pages - allocate the DMA buffer
 293  * @substream: the substream to allocate the DMA buffer to
 294  * @size: the requested buffer size in bytes
 295  *
 296  * Allocates the DMA buffer on the BUS type given earlier to
 297  * snd_pcm_lib_preallocate_xxx_pages().
 298  *
 299  * Return: 1 if the buffer is changed, 0 if not changed, or a negative
 300  * code on failure.
 301  */
 302 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
 303 {
 304         struct snd_pcm_runtime *runtime;
 305         struct snd_dma_buffer *dmab = NULL;
 306
 307         if (PCM_RUNTIME_CHECK(substream))
 308                 return -EINVAL;
 309         if (snd_BUG_ON(substream->dma_buffer.dev.type ==
 310                        SNDRV_DMA_TYPE_UNKNOWN))
 311                 return -EINVAL;
 312         runtime = substream->runtime;
 313
 314         if (runtime->dma_buffer_p) {
 315                 /* perphaps, we might free the large DMA memory region
 316                    to save some space here, but the actual solution
 317                    costs us less time */
 318                 if (runtime->dma_buffer_p->bytes >= size) {
 319                         runtime->dma_bytes = size;
 320                         return 0;       /* ok, do not change */
 321                 }
 322                 snd_pcm_lib_free_pages(substream);
 323         }
 324         if (substream->dma_buffer.area != NULL &&
 325             substream->dma_buffer.bytes >= size) {
 326                 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
 327         } else {
 328                 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
 329                 if (! dmab)
 330                         return -ENOMEM;
 331                 dmab->dev = substream->dma_buffer.dev;
 332                 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
 333                                         substream->dma_buffer.dev.dev,
 334                                         size, dmab) < 0) {
 335                         kfree(dmab);
 336                         return -ENOMEM;
 337                 }
 338         }
 339         snd_pcm_set_runtime_buffer(substream, dmab);
 340         runtime->dma_bytes = size;
 341         return 1;                       /* area was changed */
 342 }
 343 EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
 344
 345 /**
 346  * snd_pcm_lib_free_pages - release the allocated DMA buffer.
 347  * @substream: the substream to release the DMA buffer
 348  *
 349  * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
 350  *
 351  * Return: Zero if successful, or a negative error code on failure.
 352  */
 353 int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
 354 {
 355         struct snd_pcm_runtime *runtime;
 356
 357         if (PCM_RUNTIME_CHECK(substream))
 358                 return -EINVAL;
 359         runtime = substream->runtime;
 360         if (runtime->dma_area == NULL)
 361                 return 0;
 362         if (runtime->dma_buffer_p != &substream->dma_buffer) {
 363                 /* it's a newly allocated buffer.  release it now. */
 364                 snd_dma_free_pages(runtime->dma_buffer_p);
 365                 kfree(runtime->dma_buffer_p);
 366         }
 367         snd_pcm_set_runtime_buffer(substream, NULL);
 368         return 0;
 369 }
 370 EXPORT_SYMBOL(snd_pcm_lib_free_pages);
 371
 372 int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
 373                                       size_t size, gfp_t gfp_flags)
 374 {
 375         struct snd_pcm_runtime *runtime;
 376
 377         if (PCM_RUNTIME_CHECK(substream))
 378                 return -EINVAL;
 379         runtime = substream->runtime;
 380         if (runtime->dma_area) {
 381                 if (runtime->dma_bytes >= size)
 382                         return 0; /* already large enough */
 383                 vfree(runtime->dma_area);
 384         }
 385         runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
 386         if (!runtime->dma_area)
 387                 return -ENOMEM;
 388         runtime->dma_bytes = size;
 389         return 1;
 390 }
 391 EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
 392
 393 /**
 394  * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
 395  * @substream: the substream with a buffer allocated by
 396  *      snd_pcm_lib_alloc_vmalloc_buffer()
 397  *
 398  * Return: Zero if successful, or a negative error code on failure.
 399  */
 400 int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
 401 {
 402         struct snd_pcm_runtime *runtime;
 403
 404         if (PCM_RUNTIME_CHECK(substream))
 405                 return -EINVAL;
 406         runtime = substream->runtime;
 407         vfree(runtime->dma_area);
 408         runtime->dma_area = NULL;
 409         return 0;
 410 }
 411 EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
 412
 413 /**
 414  * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
 415  * @substream: the substream with a buffer allocated by
 416  *      snd_pcm_lib_alloc_vmalloc_buffer()
 417  * @offset: offset in the buffer
 418  *
 419  * This function is to be used as the page callback in the PCM ops.
 420  *
 421  * Return: The page struct, or %NULL on failure.
 422  */
 423 struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
 424                                           unsigned long offset)
 425 {
 426         return vmalloc_to_page(substream->runtime->dma_area + offset);
 427 }
 428 EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);