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 * Returns 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 * Returns 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 * Returns 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 * Returns 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 * Returns the page struct at the given buffer offset. 317 * Used as the page callback of PCM ops. 318 */ 319 struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset) 320 { 321 struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream); 322 323 unsigned int idx = offset >> PAGE_SHIFT; 324 if (idx >= (unsigned int)sgbuf->pages) 325 return NULL; 326 return sgbuf->page_table[idx]; 327 } 328 329 EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page); 330 331 /* 332 * compute the max chunk size with continuous pages on sg-buffer 333 */ 334 unsigned int snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream *substream, 335 unsigned int ofs, unsigned int size) 336 { 337 struct snd_sg_buf *sg = snd_pcm_substream_sgbuf(substream); 338 unsigned int start, end, pg; 339 340 start = ofs >> PAGE_SHIFT; 341 end = (ofs + size - 1) >> PAGE_SHIFT; 342 /* check page continuity */ 343 pg = sg->table[start].addr >> PAGE_SHIFT; 344 for (;;) { 345 start++; 346 if (start > end) 347 break; 348 pg++; 349 if ((sg->table[start].addr >> PAGE_SHIFT) != pg) 350 return (start << PAGE_SHIFT) - ofs; 351 } 352 /* ok, all on continuous pages */ 353 return size; 354 } 355 EXPORT_SYMBOL(snd_pcm_sgbuf_get_chunk_size); 356 #endif /* CONFIG_SND_DMA_SGBUF */ 357 358 /** 359 * snd_pcm_lib_malloc_pages - allocate the DMA buffer 360 * @substream: the substream to allocate the DMA buffer to 361 * @size: the requested buffer size in bytes 362 * 363 * Allocates the DMA buffer on the BUS type given earlier to 364 * snd_pcm_lib_preallocate_xxx_pages(). 365 * 366 * Returns 1 if the buffer is changed, 0 if not changed, or a negative 367 * code on failure. 368 */ 369 int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size) 370 { 371 struct snd_pcm_runtime *runtime; 372 struct snd_dma_buffer *dmab = NULL; 373 374 if (PCM_RUNTIME_CHECK(substream)) 375 return -EINVAL; 376 if (snd_BUG_ON(substream->dma_buffer.dev.type == 377 SNDRV_DMA_TYPE_UNKNOWN)) 378 return -EINVAL; 379 runtime = substream->runtime; 380 381 if (runtime->dma_buffer_p) { 382 /* perphaps, we might free the large DMA memory region 383 to save some space here, but the actual solution 384 costs us less time */ 385 if (runtime->dma_buffer_p->bytes >= size) { 386 runtime->dma_bytes = size; 387 return 0; /* ok, do not change */ 388 } 389 snd_pcm_lib_free_pages(substream); 390 } 391 if (substream->dma_buffer.area != NULL && 392 substream->dma_buffer.bytes >= size) { 393 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */ 394 } else { 395 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL); 396 if (! dmab) 397 return -ENOMEM; 398 dmab->dev = substream->dma_buffer.dev; 399 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type, 400 substream->dma_buffer.dev.dev, 401 size, dmab) < 0) { 402 kfree(dmab); 403 return -ENOMEM; 404 } 405 } 406 snd_pcm_set_runtime_buffer(substream, dmab); 407 runtime->dma_bytes = size; 408 return 1; /* area was changed */ 409 } 410 411 EXPORT_SYMBOL(snd_pcm_lib_malloc_pages); 412 413 /** 414 * snd_pcm_lib_free_pages - release the allocated DMA buffer. 415 * @substream: the substream to release the DMA buffer 416 * 417 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages(). 418 * 419 * Returns zero if successful, or a negative error code on failure. 420 */ 421 int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream) 422 { 423 struct snd_pcm_runtime *runtime; 424 425 if (PCM_RUNTIME_CHECK(substream)) 426 return -EINVAL; 427 runtime = substream->runtime; 428 if (runtime->dma_area == NULL) 429 return 0; 430 if (runtime->dma_buffer_p != &substream->dma_buffer) { 431 /* it's a newly allocated buffer. release it now. */ 432 snd_dma_free_pages(runtime->dma_buffer_p); 433 kfree(runtime->dma_buffer_p); 434 } 435 snd_pcm_set_runtime_buffer(substream, NULL); 436 return 0; 437 } 438 439 EXPORT_SYMBOL(snd_pcm_lib_free_pages); 440 441 int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream, 442 size_t size, gfp_t gfp_flags) 443 { 444 struct snd_pcm_runtime *runtime; 445 446 if (PCM_RUNTIME_CHECK(substream)) 447 return -EINVAL; 448 runtime = substream->runtime; 449 if (runtime->dma_area) { 450 if (runtime->dma_bytes >= size) 451 return 0; /* already large enough */ 452 vfree(runtime->dma_area); 453 } 454 runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL); 455 if (!runtime->dma_area) 456 return -ENOMEM; 457 runtime->dma_bytes = size; 458 return 1; 459 } 460 EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer); 461 462 /** 463 * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer 464 * @substream: the substream with a buffer allocated by 465 * snd_pcm_lib_alloc_vmalloc_buffer() 466 */ 467 int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream) 468 { 469 struct snd_pcm_runtime *runtime; 470 471 if (PCM_RUNTIME_CHECK(substream)) 472 return -EINVAL; 473 runtime = substream->runtime; 474 vfree(runtime->dma_area); 475 runtime->dma_area = NULL; 476 return 0; 477 } 478 EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer); 479 480 /** 481 * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct 482 * @substream: the substream with a buffer allocated by 483 * snd_pcm_lib_alloc_vmalloc_buffer() 484 * @offset: offset in the buffer 485 * 486 * This function is to be used as the page callback in the PCM ops. 487 */ 488 struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream, 489 unsigned long offset) 490 { 491 return vmalloc_to_page(substream->runtime->dma_area + offset); 492 } 493 EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page); 494