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 <asm/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         int err;
  55
  56         /* already reserved? */
  57         if (snd_dma_get_reserved_buf(dmab, substream->dma_buf_id) > 0) {
  58                 if (dmab->bytes >= size)
  59                         return 0; /* yes */
  60                 /* no, free the reserved block */
  61                 snd_dma_free_pages(dmab);
  62                 dmab->bytes = 0;
  63         }
  64
  65         do {
  66                 if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
  67                                                size, dmab)) < 0) {
  68                         if (err != -ENOMEM)
  69                                 return err; /* fatal error */
  70                 } else
  71                         return 0;
  72                 size >>= 1;
  73         } while (size >= snd_minimum_buffer);
  74         dmab->bytes = 0; /* tell error */
  75         return 0;
  76 }
  77
  78 /*
  79  * release the preallocated buffer if not yet done.
  80  */
  81 static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
  82 {
  83         if (substream->dma_buffer.area == NULL)
  84                 return;
  85         if (substream->dma_buf_id)
  86                 snd_dma_reserve_buf(&substream->dma_buffer, substream->dma_buf_id);
  87         else
  88                 snd_dma_free_pages(&substream->dma_buffer);
  89         substream->dma_buffer.area = NULL;
  90 }
  91
  92 /**
  93  * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
  94  * @substream: the pcm substream instance
  95  *
  96  * Releases the pre-allocated buffer of the given substream.
  97  *
  98  * Return: Zero if successful, or a negative error code on failure.
  99  */
 100 int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
 101 {
 102         snd_pcm_lib_preallocate_dma_free(substream);
 103 #ifdef CONFIG_SND_VERBOSE_PROCFS
 104         snd_info_free_entry(substream->proc_prealloc_max_entry);
 105         substream->proc_prealloc_max_entry = NULL;
 106         snd_info_free_entry(substream->proc_prealloc_entry);
 107         substream->proc_prealloc_entry = NULL;
 108 #endif
 109         return 0;
 110 }
 111
 112 /**
 113  * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
 114  * @pcm: the pcm instance
 115  *
 116  * Releases all the pre-allocated buffers on the given pcm.
 117  *
 118  * Return: Zero if successful, or a negative error code on failure.
 119  */
 120 int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
 121 {
 122         struct snd_pcm_substream *substream;
 123         int stream;
 124
 125         for (stream = 0; stream < 2; stream++)
 126                 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
 127                         snd_pcm_lib_preallocate_free(substream);
 128         return 0;
 129 }
 130
 131 EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
 132
 133 #ifdef CONFIG_SND_VERBOSE_PROCFS
 134 /*
 135  * read callback for prealloc proc file
 136  *
 137  * prints the current allocated size in kB.
 138  */
 139 static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
 140                                               struct snd_info_buffer *buffer)
 141 {
 142         struct snd_pcm_substream *substream = entry->private_data;
 143         snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
 144 }
 145
 146 /*
 147  * read callback for prealloc_max proc file
 148  *
 149  * prints the maximum allowed size in kB.
 150  */
 151 static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
 152                                                   struct snd_info_buffer *buffer)
 153 {
 154         struct snd_pcm_substream *substream = entry->private_data;
 155         snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
 156 }
 157
 158 /*
 159  * write callback for prealloc proc file
 160  *
 161  * accepts the preallocation size in kB.
 162  */
 163 static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
 164                                                struct snd_info_buffer *buffer)
 165 {
 166         struct snd_pcm_substream *substream = entry->private_data;
 167         char line[64], str[64];
 168         size_t size;
 169         struct snd_dma_buffer new_dmab;
 170
 171         if (substream->runtime) {
 172                 buffer->error = -EBUSY;
 173                 return;
 174         }
 175         if (!snd_info_get_line(buffer, line, sizeof(line))) {
 176                 snd_info_get_str(str, line, sizeof(str));
 177                 size = simple_strtoul(str, NULL, 10) * 1024;
 178                 if ((size != 0 && size < 8192) || size > substream->dma_max) {
 179                         buffer->error = -EINVAL;
 180                         return;
 181                 }
 182                 if (substream->dma_buffer.bytes == size)
 183                         return;
 184                 memset(&new_dmab, 0, sizeof(new_dmab));
 185                 new_dmab.dev = substream->dma_buffer.dev;
 186                 if (size > 0) {
 187                         if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
 188                                                 substream->dma_buffer.dev.dev,
 189                                                 size, &new_dmab) < 0) {
 190                                 buffer->error = -ENOMEM;
 191                                 return;
 192                         }
 193                         substream->buffer_bytes_max = size;
 194                 } else {
 195                         substream->buffer_bytes_max = UINT_MAX;
 196                 }
 197                 if (substream->dma_buffer.area)
 198                         snd_dma_free_pages(&substream->dma_buffer);
 199                 substream->dma_buffer = new_dmab;
 200         } else {
 201                 buffer->error = -EINVAL;
 202         }
 203 }
 204
 205 static inline void preallocate_info_init(struct snd_pcm_substream *substream)
 206 {
 207         struct snd_info_entry *entry;
 208
 209         if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
 210                 entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
 211                 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
 212                 entry->mode |= S_IWUSR;
 213                 entry->private_data = substream;
 214                 if (snd_info_register(entry) < 0) {
 215                         snd_info_free_entry(entry);
 216                         entry = NULL;
 217                 }
 218         }
 219         substream->proc_prealloc_entry = entry;
 220         if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
 221                 entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
 222                 entry->private_data = substream;
 223                 if (snd_info_register(entry) < 0) {
 224                         snd_info_free_entry(entry);
 225                         entry = NULL;
 226                 }
 227         }
 228         substream->proc_prealloc_max_entry = entry;
 229 }
 230
 231 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 232 #define preallocate_info_init(s)
 233 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 234
 235 /*
 236  * pre-allocate the buffer and create a proc file for the substream
 237  */
 238 static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
 239                                           size_t size, size_t max)
 240 {
 241
 242         if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
 243                 preallocate_pcm_pages(substream, size);
 244
 245         if (substream->dma_buffer.bytes > 0)
 246                 substream->buffer_bytes_max = substream->dma_buffer.bytes;
 247         substream->dma_max = max;
 248         preallocate_info_init(substream);
 249         return 0;
 250 }
 251
 252
 253 /**
 254  * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
 255  * @substream: the pcm substream instance
 256  * @type: DMA type (SNDRV_DMA_TYPE_*)
 257  * @data: DMA type dependent data
 258  * @size: the requested pre-allocation size in bytes
 259  * @max: the max. allowed pre-allocation size
 260  *
 261  * Do pre-allocation for the given DMA buffer type.
 262  *
 263  * When substream->dma_buf_id is set, the function tries to look for
 264  * the reserved buffer, and the buffer is not freed but reserved at
 265  * destruction time.  The dma_buf_id must be unique for all systems
 266  * (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id().
 267  *
 268  * Return: Zero if successful, or a negative error code on failure.
 269  */
 270 int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
 271                                   int type, struct device *data,
 272                                   size_t size, size_t max)
 273 {
 274         substream->dma_buffer.dev.type = type;
 275         substream->dma_buffer.dev.dev = data;
 276         return snd_pcm_lib_preallocate_pages1(substream, size, max);
 277 }
 278
 279 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
 280
 281 /**
 282  * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams)
 283  * @pcm: the pcm instance
 284  * @type: DMA type (SNDRV_DMA_TYPE_*)
 285  * @data: DMA type dependent data
 286  * @size: the requested pre-allocation size in bytes
 287  * @max: the max. allowed pre-allocation size
 288  *
 289  * Do pre-allocation to all substreams of the given pcm for the
 290  * specified DMA type.
 291  *
 292  * Return: Zero if successful, or a negative error code on failure.
 293  */
 294 int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
 295                                           int type, void *data,
 296                                           size_t size, size_t max)
 297 {
 298         struct snd_pcm_substream *substream;
 299         int stream, err;
 300
 301         for (stream = 0; stream < 2; stream++)
 302                 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
 303                         if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
 304                                 return err;
 305         return 0;
 306 }
 307
 308 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
 309
 310 #ifdef CONFIG_SND_DMA_SGBUF
 311 /**
 312  * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
 313  * @substream: the pcm substream instance
 314  * @offset: the buffer offset
 315  *
 316  * Used as the page callback of PCM ops.
 317  *
 318  * Return: The page struct at the given buffer offset. %NULL on failure.
 319  */
 320 struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
 321 {
 322         struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
 323
 324         unsigned int idx = offset >> PAGE_SHIFT;
 325         if (idx >= (unsigned int)sgbuf->pages)
 326                 return NULL;
 327         return sgbuf->page_table[idx];
 328 }
 329
 330 EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
 331 #endif /* CONFIG_SND_DMA_SGBUF */
 332
 333 /**
 334  * snd_pcm_lib_malloc_pages - allocate the DMA buffer
 335  * @substream: the substream to allocate the DMA buffer to
 336  * @size: the requested buffer size in bytes
 337  *
 338  * Allocates the DMA buffer on the BUS type given earlier to
 339  * snd_pcm_lib_preallocate_xxx_pages().
 340  *
 341  * Return: 1 if the buffer is changed, 0 if not changed, or a negative
 342  * code on failure.
 343  */
 344 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
 345 {
 346         struct snd_pcm_runtime *runtime;
 347         struct snd_dma_buffer *dmab = NULL;
 348
 349         if (PCM_RUNTIME_CHECK(substream))
 350                 return -EINVAL;
 351         if (snd_BUG_ON(substream->dma_buffer.dev.type ==
 352                        SNDRV_DMA_TYPE_UNKNOWN))
 353                 return -EINVAL;
 354         runtime = substream->runtime;
 355
 356         if (runtime->dma_buffer_p) {
 357                 /* perphaps, we might free the large DMA memory region
 358                    to save some space here, but the actual solution
 359                    costs us less time */
 360                 if (runtime->dma_buffer_p->bytes >= size) {
 361                         runtime->dma_bytes = size;
 362                         return 0;       /* ok, do not change */
 363                 }
 364                 snd_pcm_lib_free_pages(substream);
 365         }
 366         if (substream->dma_buffer.area != NULL &&
 367             substream->dma_buffer.bytes >= size) {
 368                 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
 369         } else {
 370                 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
 371                 if (! dmab)
 372                         return -ENOMEM;
 373                 dmab->dev = substream->dma_buffer.dev;
 374                 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
 375                                         substream->dma_buffer.dev.dev,
 376                                         size, dmab) < 0) {
 377                         kfree(dmab);
 378                         return -ENOMEM;
 379                 }
 380         }
 381         snd_pcm_set_runtime_buffer(substream, dmab);
 382         runtime->dma_bytes = size;
 383         return 1;                       /* area was changed */
 384 }
 385
 386 EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
 387
 388 /**
 389  * snd_pcm_lib_free_pages - release the allocated DMA buffer.
 390  * @substream: the substream to release the DMA buffer
 391  *
 392  * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
 393  *
 394  * Return: Zero if successful, or a negative error code on failure.
 395  */
 396 int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
 397 {
 398         struct snd_pcm_runtime *runtime;
 399
 400         if (PCM_RUNTIME_CHECK(substream))
 401                 return -EINVAL;
 402         runtime = substream->runtime;
 403         if (runtime->dma_area == NULL)
 404                 return 0;
 405         if (runtime->dma_buffer_p != &substream->dma_buffer) {
 406                 /* it's a newly allocated buffer.  release it now. */
 407                 snd_dma_free_pages(runtime->dma_buffer_p);
 408                 kfree(runtime->dma_buffer_p);
 409         }
 410         snd_pcm_set_runtime_buffer(substream, NULL);
 411         return 0;
 412 }
 413
 414 EXPORT_SYMBOL(snd_pcm_lib_free_pages);
 415
 416 int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
 417                                       size_t size, gfp_t gfp_flags)
 418 {
 419         struct snd_pcm_runtime *runtime;
 420
 421         if (PCM_RUNTIME_CHECK(substream))
 422                 return -EINVAL;
 423         runtime = substream->runtime;
 424         if (runtime->dma_area) {
 425                 if (runtime->dma_bytes >= size)
 426                         return 0; /* already large enough */
 427                 vfree(runtime->dma_area);
 428         }
 429         runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
 430         if (!runtime->dma_area)
 431                 return -ENOMEM;
 432         runtime->dma_bytes = size;
 433         return 1;
 434 }
 435 EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
 436
 437 /**
 438  * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
 439  * @substream: the substream with a buffer allocated by
 440  *      snd_pcm_lib_alloc_vmalloc_buffer()
 441  *
 442  * Return: Zero if successful, or a negative error code on failure.
 443  */
 444 int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
 445 {
 446         struct snd_pcm_runtime *runtime;
 447
 448         if (PCM_RUNTIME_CHECK(substream))
 449                 return -EINVAL;
 450         runtime = substream->runtime;
 451         vfree(runtime->dma_area);
 452         runtime->dma_area = NULL;
 453         return 0;
 454 }
 455 EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
 456
 457 /**
 458  * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
 459  * @substream: the substream with a buffer allocated by
 460  *      snd_pcm_lib_alloc_vmalloc_buffer()
 461  * @offset: offset in the buffer
 462  *
 463  * This function is to be used as the page callback in the PCM ops.
 464  *
 465  * Return: The page struct, or %NULL on failure.
 466  */
 467 struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
 468                                           unsigned long offset)
 469 {
 470         return vmalloc_to_page(substream->runtime->dma_area + offset);
 471 }
 472 EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);