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/moduleparam.h>
  26 #include <linux/vmalloc.h>
  27 #include <sound/core.h>
  28 #include <sound/pcm.h>
  29 #include <sound/info.h>
  30 #include <sound/initval.h>
  31
  32 static int preallocate_dma = 1;
  33 module_param(preallocate_dma, int, 0444);
  34 MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized.");
  35
  36 static int maximum_substreams = 4;
  37 module_param(maximum_substreams, int, 0444);
  38 MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory.");
  39
  40 static const size_t snd_minimum_buffer = 16384;
  41
  42
  43 /*
  44  * try to allocate as the large pages as possible.
  45  * stores the resultant memory size in *res_size.
  46  *
  47  * the minimum size is snd_minimum_buffer.  it should be power of 2.
  48  */
  49 static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size)
  50 {
  51         struct snd_dma_buffer *dmab = &substream->dma_buffer;
  52         int err;
  53
  54         /* already reserved? */
  55         if (snd_dma_get_reserved_buf(dmab, substream->dma_buf_id) > 0) {
  56                 if (dmab->bytes >= size)
  57                         return 0; /* yes */
  58                 /* no, free the reserved block */
  59                 snd_dma_free_pages(dmab);
  60                 dmab->bytes = 0;
  61         }
  62
  63         do {
  64                 if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev,
  65                                                size, dmab)) < 0) {
  66                         if (err != -ENOMEM)
  67                                 return err; /* fatal error */
  68                 } else
  69                         return 0;
  70                 size >>= 1;
  71         } while (size >= snd_minimum_buffer);
  72         dmab->bytes = 0; /* tell error */
  73         return 0;
  74 }
  75
  76 /*
  77  * release the preallocated buffer if not yet done.
  78  */
  79 static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
  80 {
  81         if (substream->dma_buffer.area == NULL)
  82                 return;
  83         if (substream->dma_buf_id)
  84                 snd_dma_reserve_buf(&substream->dma_buffer, substream->dma_buf_id);
  85         else
  86                 snd_dma_free_pages(&substream->dma_buffer);
  87         substream->dma_buffer.area = NULL;
  88 }
  89
  90 /**
  91  * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
  92  * @substream: the pcm substream instance
  93  *
  94  * Releases the pre-allocated buffer of the given substream.
  95  *
  96  * Returns zero if successful, or a negative error code on failure.
  97  */
  98 int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
  99 {
 100         snd_pcm_lib_preallocate_dma_free(substream);
 101 #ifdef CONFIG_SND_VERBOSE_PROCFS
 102         snd_info_free_entry(substream->proc_prealloc_max_entry);
 103         substream->proc_prealloc_max_entry = NULL;
 104         snd_info_free_entry(substream->proc_prealloc_entry);
 105         substream->proc_prealloc_entry = NULL;
 106 #endif
 107         return 0;
 108 }
 109
 110 /**
 111  * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm
 112  * @pcm: the pcm instance
 113  *
 114  * Releases all the pre-allocated buffers on the given pcm.
 115  *
 116  * Returns zero if successful, or a negative error code on failure.
 117  */
 118 int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
 119 {
 120         struct snd_pcm_substream *substream;
 121         int stream;
 122
 123         for (stream = 0; stream < 2; stream++)
 124                 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
 125                         snd_pcm_lib_preallocate_free(substream);
 126         return 0;
 127 }
 128
 129 EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all);
 130
 131 #ifdef CONFIG_SND_VERBOSE_PROCFS
 132 /*
 133  * read callback for prealloc proc file
 134  *
 135  * prints the current allocated size in kB.
 136  */
 137 static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry,
 138                                               struct snd_info_buffer *buffer)
 139 {
 140         struct snd_pcm_substream *substream = entry->private_data;
 141         snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);
 142 }
 143
 144 /*
 145  * read callback for prealloc_max proc file
 146  *
 147  * prints the maximum allowed size in kB.
 148  */
 149 static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
 150                                                   struct snd_info_buffer *buffer)
 151 {
 152         struct snd_pcm_substream *substream = entry->private_data;
 153         snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
 154 }
 155
 156 /*
 157  * write callback for prealloc proc file
 158  *
 159  * accepts the preallocation size in kB.
 160  */
 161 static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry,
 162                                                struct snd_info_buffer *buffer)
 163 {
 164         struct snd_pcm_substream *substream = entry->private_data;
 165         char line[64], str[64];
 166         size_t size;
 167         struct snd_dma_buffer new_dmab;
 168
 169         if (substream->runtime) {
 170                 buffer->error = -EBUSY;
 171                 return;
 172         }
 173         if (!snd_info_get_line(buffer, line, sizeof(line))) {
 174                 snd_info_get_str(str, line, sizeof(str));
 175                 size = simple_strtoul(str, NULL, 10) * 1024;
 176                 if ((size != 0 && size < 8192) || size > substream->dma_max) {
 177                         buffer->error = -EINVAL;
 178                         return;
 179                 }
 180                 if (substream->dma_buffer.bytes == size)
 181                         return;
 182                 memset(&new_dmab, 0, sizeof(new_dmab));
 183                 new_dmab.dev = substream->dma_buffer.dev;
 184                 if (size > 0) {
 185                         if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
 186                                                 substream->dma_buffer.dev.dev,
 187                                                 size, &new_dmab) < 0) {
 188                                 buffer->error = -ENOMEM;
 189                                 return;
 190                         }
 191                         substream->buffer_bytes_max = size;
 192                 } else {
 193                         substream->buffer_bytes_max = UINT_MAX;
 194                 }
 195                 if (substream->dma_buffer.area)
 196                         snd_dma_free_pages(&substream->dma_buffer);
 197                 substream->dma_buffer = new_dmab;
 198         } else {
 199                 buffer->error = -EINVAL;
 200         }
 201 }
 202
 203 static inline void preallocate_info_init(struct snd_pcm_substream *substream)
 204 {
 205         struct snd_info_entry *entry;
 206
 207         if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
 208                 entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
 209                 entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
 210                 entry->mode |= S_IWUSR;
 211                 entry->private_data = substream;
 212                 if (snd_info_register(entry) < 0) {
 213                         snd_info_free_entry(entry);
 214                         entry = NULL;
 215                 }
 216         }
 217         substream->proc_prealloc_entry = entry;
 218         if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
 219                 entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
 220                 entry->private_data = substream;
 221                 if (snd_info_register(entry) < 0) {
 222                         snd_info_free_entry(entry);
 223                         entry = NULL;
 224                 }
 225         }
 226         substream->proc_prealloc_max_entry = entry;
 227 }
 228
 229 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 230 #define preallocate_info_init(s)
 231 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 232
 233 /*
 234  * pre-allocate the buffer and create a proc file for the substream
 235  */
 236 static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
 237                                           size_t size, size_t max)
 238 {
 239
 240         if (size > 0 && preallocate_dma && substream->number < maximum_substreams)
 241                 preallocate_pcm_pages(substream, size);
 242
 243         if (substream->dma_buffer.bytes > 0)
 244                 substream->buffer_bytes_max = substream->dma_buffer.bytes;
 245         substream->dma_max = max;
 246         preallocate_info_init(substream);
 247         return 0;
 248 }
 249
 250
 251 /**
 252  * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type
 253  * @substream: the pcm substream instance
 254  * @type: DMA type (SNDRV_DMA_TYPE_*)
 255  * @data: DMA type dependant data
 256  * @size: the requested pre-allocation size in bytes
 257  * @max: the max. allowed pre-allocation size
 258  *
 259  * Do pre-allocation for the given DMA buffer type.
 260  *
 261  * When substream->dma_buf_id is set, the function tries to look for
 262  * the reserved buffer, and the buffer is not freed but reserved at
 263  * destruction time.  The dma_buf_id must be unique for all systems
 264  * (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id().
 265  *
 266  * Returns zero if successful, or a negative error code on failure.
 267  */
 268 int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
 269                                   int type, struct device *data,
 270                                   size_t size, size_t max)
 271 {
 272         substream->dma_buffer.dev.type = type;
 273         substream->dma_buffer.dev.dev = data;
 274         return snd_pcm_lib_preallocate_pages1(substream, size, max);
 275 }
 276
 277 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages);
 278
 279 /**
 280  * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continous memory type (all substreams)
 281  * @pcm: the pcm instance
 282  * @type: DMA type (SNDRV_DMA_TYPE_*)
 283  * @data: DMA type dependant data
 284  * @size: the requested pre-allocation size in bytes
 285  * @max: the max. allowed pre-allocation size
 286  *
 287  * Do pre-allocation to all substreams of the given pcm for the
 288  * specified DMA type.
 289  *
 290  * Returns zero if successful, or a negative error code on failure.
 291  */
 292 int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
 293                                           int type, void *data,
 294                                           size_t size, size_t max)
 295 {
 296         struct snd_pcm_substream *substream;
 297         int stream, err;
 298
 299         for (stream = 0; stream < 2; stream++)
 300                 for (substream = pcm->streams[stream].substream; substream; substream = substream->next)
 301                         if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0)
 302                                 return err;
 303         return 0;
 304 }
 305
 306 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
 307
 308 #ifdef CONFIG_SND_DMA_SGBUF
 309 /**
 310  * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
 311  * @substream: the pcm substream instance
 312  * @offset: the buffer offset
 313  *
 314  * Returns the page struct at the given buffer offset.
 315  * Used as the page callback of PCM ops.
 316  */
 317 struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset)
 318 {
 319         struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream);
 320
 321         unsigned int idx = offset >> PAGE_SHIFT;
 322         if (idx >= (unsigned int)sgbuf->pages)
 323                 return NULL;
 324         return sgbuf->page_table[idx];
 325 }
 326
 327 EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
 328
 329 /*
 330  * compute the max chunk size with continuous pages on sg-buffer
 331  */
 332 unsigned int snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream *substream,
 333                                           unsigned int ofs, unsigned int size)
 334 {
 335         struct snd_sg_buf *sg = snd_pcm_substream_sgbuf(substream);
 336         unsigned int start, end, pg;
 337
 338         start = ofs >> PAGE_SHIFT;
 339         end = (ofs + size - 1) >> PAGE_SHIFT;
 340         /* check page continuity */
 341         pg = sg->table[start].addr >> PAGE_SHIFT;
 342         for (;;) {
 343                 start++;
 344                 if (start > end)
 345                         break;
 346                 pg++;
 347                 if ((sg->table[start].addr >> PAGE_SHIFT) != pg)
 348                         return (start << PAGE_SHIFT) - ofs;
 349         }
 350         /* ok, all on continuous pages */
 351         return size;
 352 }
 353 EXPORT_SYMBOL(snd_pcm_sgbuf_get_chunk_size);
 354 #endif /* CONFIG_SND_DMA_SGBUF */
 355
 356 /**
 357  * snd_pcm_lib_malloc_pages - allocate the DMA buffer
 358  * @substream: the substream to allocate the DMA buffer to
 359  * @size: the requested buffer size in bytes
 360  *
 361  * Allocates the DMA buffer on the BUS type given earlier to
 362  * snd_pcm_lib_preallocate_xxx_pages().
 363  *
 364  * Returns 1 if the buffer is changed, 0 if not changed, or a negative
 365  * code on failure.
 366  */
 367 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
 368 {
 369         struct snd_pcm_runtime *runtime;
 370         struct snd_dma_buffer *dmab = NULL;
 371
 372         if (PCM_RUNTIME_CHECK(substream))
 373                 return -EINVAL;
 374         if (snd_BUG_ON(substream->dma_buffer.dev.type ==
 375                        SNDRV_DMA_TYPE_UNKNOWN))
 376                 return -EINVAL;
 377         runtime = substream->runtime;
 378
 379         if (runtime->dma_buffer_p) {
 380                 /* perphaps, we might free the large DMA memory region
 381                    to save some space here, but the actual solution
 382                    costs us less time */
 383                 if (runtime->dma_buffer_p->bytes >= size) {
 384                         runtime->dma_bytes = size;
 385                         return 0;       /* ok, do not change */
 386                 }
 387                 snd_pcm_lib_free_pages(substream);
 388         }
 389         if (substream->dma_buffer.area != NULL &&
 390             substream->dma_buffer.bytes >= size) {
 391                 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */
 392         } else {
 393                 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL);
 394                 if (! dmab)
 395                         return -ENOMEM;
 396                 dmab->dev = substream->dma_buffer.dev;
 397                 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type,
 398                                         substream->dma_buffer.dev.dev,
 399                                         size, dmab) < 0) {
 400                         kfree(dmab);
 401                         return -ENOMEM;
 402                 }
 403         }
 404         snd_pcm_set_runtime_buffer(substream, dmab);
 405         runtime->dma_bytes = size;
 406         return 1;                       /* area was changed */
 407 }
 408
 409 EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
 410
 411 /**
 412  * snd_pcm_lib_free_pages - release the allocated DMA buffer.
 413  * @substream: the substream to release the DMA buffer
 414  *
 415  * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages().
 416  *
 417  * Returns zero if successful, or a negative error code on failure.
 418  */
 419 int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
 420 {
 421         struct snd_pcm_runtime *runtime;
 422
 423         if (PCM_RUNTIME_CHECK(substream))
 424                 return -EINVAL;
 425         runtime = substream->runtime;
 426         if (runtime->dma_area == NULL)
 427                 return 0;
 428         if (runtime->dma_buffer_p != &substream->dma_buffer) {
 429                 /* it's a newly allocated buffer.  release it now. */
 430                 snd_dma_free_pages(runtime->dma_buffer_p);
 431                 kfree(runtime->dma_buffer_p);
 432         }
 433         snd_pcm_set_runtime_buffer(substream, NULL);
 434         return 0;
 435 }
 436
 437 EXPORT_SYMBOL(snd_pcm_lib_free_pages);
 438
 439 int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
 440                                       size_t size, gfp_t gfp_flags)
 441 {
 442         struct snd_pcm_runtime *runtime;
 443
 444         if (PCM_RUNTIME_CHECK(substream))
 445                 return -EINVAL;
 446         runtime = substream->runtime;
 447         if (runtime->dma_area) {
 448                 if (runtime->dma_bytes >= size)
 449                         return 0; /* already large enough */
 450                 vfree(runtime->dma_area);
 451         }
 452         runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL);
 453         if (!runtime->dma_area)
 454                 return -ENOMEM;
 455         runtime->dma_bytes = size;
 456         return 1;
 457 }
 458 EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer);
 459
 460 /**
 461  * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer
 462  * @substream: the substream with a buffer allocated by
 463  *      snd_pcm_lib_alloc_vmalloc_buffer()
 464  */
 465 int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream)
 466 {
 467         struct snd_pcm_runtime *runtime;
 468
 469         if (PCM_RUNTIME_CHECK(substream))
 470                 return -EINVAL;
 471         runtime = substream->runtime;
 472         vfree(runtime->dma_area);
 473         runtime->dma_area = NULL;
 474         return 0;
 475 }
 476 EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer);
 477
 478 /**
 479  * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct
 480  * @substream: the substream with a buffer allocated by
 481  *      snd_pcm_lib_alloc_vmalloc_buffer()
 482  * @offset: offset in the buffer
 483  *
 484  * This function is to be used as the page callback in the PCM ops.
 485  */
 486 struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
 487                                           unsigned long offset)
 488 {
 489         return vmalloc_to_page(substream->runtime->dma_area + offset);
 490 }
 491 EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page);