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 <sound/core.h> 29#include <sound/pcm.h> 30#include <sound/info.h> 31#include <sound/initval.h> 32 33static int preallocate_dma = 1; 34module_param(preallocate_dma, int, 0444); 35MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized."); 36 37static int maximum_substreams = 4; 38module_param(maximum_substreams, int, 0444); 39MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory."); 40 41static const size_t snd_minimum_buffer = 16384; 42 43 44/* 45 * try to allocate as the large pages as possible. 46 * stores the resultant memory size in *res_size. 47 * 48 * the minimum size is snd_minimum_buffer. it should be power of 2. 49 */ 50static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t size) 51{ 52 struct snd_dma_buffer *dmab = &substream->dma_buffer; 53 int err; 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 */ 80static 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 */ 99int 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 */ 119int 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 130EXPORT_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 */ 138static 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 */ 150static 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 */ 162static 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 204static 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 */ 237static 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 */ 269int 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 278EXPORT_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 */ 293int 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 307EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all); 308 309#ifdef CONFIG_SND_DMA_SGBUF 310/** 311 * snd_pcm_sgbuf_ops_page - get the page struct at the given offset 312 * @substream: the pcm substream instance 313 * @offset: the buffer offset 314 * 315 * Returns the page struct at the given buffer offset. 316 * Used as the page callback of PCM ops. 317 */ 318struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset) 319{ 320 struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream); 321 322 unsigned int idx = offset >> PAGE_SHIFT; 323 if (idx >= (unsigned int)sgbuf->pages) 324 return NULL; 325 return sgbuf->page_table[idx]; 326} 327 328EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page); 329 330/* 331 * compute the max chunk size with continuous pages on sg-buffer 332 */ 333unsigned int snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream *substream, 334 unsigned int ofs, unsigned int size) 335{ 336 struct snd_sg_buf *sg = snd_pcm_substream_sgbuf(substream); 337 unsigned int start, end, pg; 338 339 start = ofs >> PAGE_SHIFT; 340 end = (ofs + size - 1) >> PAGE_SHIFT; 341 /* check page continuity */ 342 pg = sg->table[start].addr >> PAGE_SHIFT; 343 for (;;) { 344 start++; 345 if (start > end) 346 break; 347 pg++; 348 if ((sg->table[start].addr >> PAGE_SHIFT) != pg) 349 return (start << PAGE_SHIFT) - ofs; 350 } 351 /* ok, all on continuous pages */ 352 return size; 353} 354EXPORT_SYMBOL(snd_pcm_sgbuf_get_chunk_size); 355#endif /* CONFIG_SND_DMA_SGBUF */ 356 357/** 358 * snd_pcm_lib_malloc_pages - allocate the DMA buffer 359 * @substream: the substream to allocate the DMA buffer to 360 * @size: the requested buffer size in bytes 361 * 362 * Allocates the DMA buffer on the BUS type given earlier to 363 * snd_pcm_lib_preallocate_xxx_pages(). 364 * 365 * Returns 1 if the buffer is changed, 0 if not changed, or a negative 366 * code on failure. 367 */ 368int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size) 369{ 370 struct snd_pcm_runtime *runtime; 371 struct snd_dma_buffer *dmab = NULL; 372 373 if (PCM_RUNTIME_CHECK(substream)) 374 return -EINVAL; 375 if (snd_BUG_ON(substream->dma_buffer.dev.type == 376 SNDRV_DMA_TYPE_UNKNOWN)) 377 return -EINVAL; 378 runtime = substream->runtime; 379 380 if (runtime->dma_buffer_p) { 381 /* perphaps, we might free the large DMA memory region 382 to save some space here, but the actual solution 383 costs us less time */ 384 if (runtime->dma_buffer_p->bytes >= size) { 385 runtime->dma_bytes = size; 386 return 0; /* ok, do not change */ 387 } 388 snd_pcm_lib_free_pages(substream); 389 } 390 if (substream->dma_buffer.area != NULL && 391 substream->dma_buffer.bytes >= size) { 392 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */ 393 } else { 394 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL); 395 if (! dmab) 396 return -ENOMEM; 397 dmab->dev = substream->dma_buffer.dev; 398 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type, 399 substream->dma_buffer.dev.dev, 400 size, dmab) < 0) { 401 kfree(dmab); 402 return -ENOMEM; 403 } 404 } 405 snd_pcm_set_runtime_buffer(substream, dmab); 406 runtime->dma_bytes = size; 407 return 1; /* area was changed */ 408} 409 410EXPORT_SYMBOL(snd_pcm_lib_malloc_pages); 411 412/** 413 * snd_pcm_lib_free_pages - release the allocated DMA buffer. 414 * @substream: the substream to release the DMA buffer 415 * 416 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages(). 417 * 418 * Returns zero if successful, or a negative error code on failure. 419 */ 420int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream) 421{ 422 struct snd_pcm_runtime *runtime; 423 424 if (PCM_RUNTIME_CHECK(substream)) 425 return -EINVAL; 426 runtime = substream->runtime; 427 if (runtime->dma_area == NULL) 428 return 0; 429 if (runtime->dma_buffer_p != &substream->dma_buffer) { 430 /* it's a newly allocated buffer. release it now. */ 431 snd_dma_free_pages(runtime->dma_buffer_p); 432 kfree(runtime->dma_buffer_p); 433 } 434 snd_pcm_set_runtime_buffer(substream, NULL); 435 return 0; 436} 437 438EXPORT_SYMBOL(snd_pcm_lib_free_pages); 439 440int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream, 441 size_t size, gfp_t gfp_flags) 442{ 443 struct snd_pcm_runtime *runtime; 444 445 if (PCM_RUNTIME_CHECK(substream)) 446 return -EINVAL; 447 runtime = substream->runtime; 448 if (runtime->dma_area) { 449 if (runtime->dma_bytes >= size) 450 return 0; /* already large enough */ 451 vfree(runtime->dma_area); 452 } 453 runtime->dma_area = __vmalloc(size, gfp_flags, PAGE_KERNEL); 454 if (!runtime->dma_area) 455 return -ENOMEM; 456 runtime->dma_bytes = size; 457 return 1; 458} 459EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer); 460 461/** 462 * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer 463 * @substream: the substream with a buffer allocated by 464 * snd_pcm_lib_alloc_vmalloc_buffer() 465 */ 466int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream) 467{ 468 struct snd_pcm_runtime *runtime; 469 470 if (PCM_RUNTIME_CHECK(substream)) 471 return -EINVAL; 472 runtime = substream->runtime; 473 vfree(runtime->dma_area); 474 runtime->dma_area = NULL; 475 return 0; 476} 477EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer); 478 479/** 480 * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct 481 * @substream: the substream with a buffer allocated by 482 * snd_pcm_lib_alloc_vmalloc_buffer() 483 * @offset: offset in the buffer 484 * 485 * This function is to be used as the page callback in the PCM ops. 486 */ 487struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream, 488 unsigned long offset) 489{ 490 return vmalloc_to_page(substream->runtime->dma_area + offset); 491} 492EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page); 493