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