1/* 2 * Digital Audio (PCM) abstract layer 3 * Copyright (c) by Jaroslav Kysela <perex@suse.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 <sound/driver.h> 23#include <asm/io.h> 24#include <linux/time.h> 25#include <linux/init.h> 26#include <linux/moduleparam.h> 27#include <sound/core.h> 28#include <sound/pcm.h> 29#include <sound/info.h> 30#include <sound/initval.h> 31 32static int preallocate_dma = 1; 33module_param(preallocate_dma, int, 0444); 34MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized."); 35 36static int maximum_substreams = 4; 37module_param(maximum_substreams, int, 0444); 38MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory."); 39 40static 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 */ 49static 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 snd_assert(size > 0, return -EINVAL); 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 */ 81static 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 */ 100int 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 */ 120int 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 131EXPORT_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 */ 139static 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 */ 151static 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 */ 163static 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 205static 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 */ 238static 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 dependant 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 */ 270int 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 279EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages); 280 281/** 282 * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continous memory type (all substreams) 283 * @pcm: the pcm instance 284 * @type: DMA type (SNDRV_DMA_TYPE_*) 285 * @data: DMA type dependant 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 */ 294int 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 308EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all); 309 310/** 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 * snd_pcm_lib_malloc_pages - allocate the DMA buffer 332 * @substream: the substream to allocate the DMA buffer to 333 * @size: the requested buffer size in bytes 334 * 335 * Allocates the DMA buffer on the BUS type given earlier to 336 * snd_pcm_lib_preallocate_xxx_pages(). 337 * 338 * Returns 1 if the buffer is changed, 0 if not changed, or a negative 339 * code on failure. 340 */ 341int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size) 342{ 343 struct snd_pcm_runtime *runtime; 344 struct snd_dma_buffer *dmab = NULL; 345 346 snd_assert(substream->dma_buffer.dev.type != SNDRV_DMA_TYPE_UNKNOWN, return -EINVAL); 347 snd_assert(substream != NULL, return -EINVAL); 348 runtime = substream->runtime; 349 snd_assert(runtime != NULL, return -EINVAL); 350 351 if (runtime->dma_buffer_p) { 352 /* perphaps, we might free the large DMA memory region 353 to save some space here, but the actual solution 354 costs us less time */ 355 if (runtime->dma_buffer_p->bytes >= size) { 356 runtime->dma_bytes = size; 357 return 0; /* ok, do not change */ 358 } 359 snd_pcm_lib_free_pages(substream); 360 } 361 if (substream->dma_buffer.area != NULL && 362 substream->dma_buffer.bytes >= size) { 363 dmab = &substream->dma_buffer; /* use the pre-allocated buffer */ 364 } else { 365 dmab = kzalloc(sizeof(*dmab), GFP_KERNEL); 366 if (! dmab) 367 return -ENOMEM; 368 dmab->dev = substream->dma_buffer.dev; 369 if (snd_dma_alloc_pages(substream->dma_buffer.dev.type, 370 substream->dma_buffer.dev.dev, 371 size, dmab) < 0) { 372 kfree(dmab); 373 return -ENOMEM; 374 } 375 } 376 snd_pcm_set_runtime_buffer(substream, dmab); 377 runtime->dma_bytes = size; 378 return 1; /* area was changed */ 379} 380 381EXPORT_SYMBOL(snd_pcm_lib_malloc_pages); 382 383/** 384 * snd_pcm_lib_free_pages - release the allocated DMA buffer. 385 * @substream: the substream to release the DMA buffer 386 * 387 * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages(). 388 * 389 * Returns zero if successful, or a negative error code on failure. 390 */ 391int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream) 392{ 393 struct snd_pcm_runtime *runtime; 394 395 snd_assert(substream != NULL, return -EINVAL); 396 runtime = substream->runtime; 397 snd_assert(runtime != NULL, return -EINVAL); 398 if (runtime->dma_area == NULL) 399 return 0; 400 if (runtime->dma_buffer_p != &substream->dma_buffer) { 401 /* it's a newly allocated buffer. release it now. */ 402 snd_dma_free_pages(runtime->dma_buffer_p); 403 kfree(runtime->dma_buffer_p); 404 } 405 snd_pcm_set_runtime_buffer(substream, NULL); 406 return 0; 407} 408 409EXPORT_SYMBOL(snd_pcm_lib_free_pages); 410