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