Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 32 | static int preallocate_dma = 1; |
| 33 | module_param(preallocate_dma, int, 0444); |
| 34 | MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized."); |
| 35 | |
| 36 | static int maximum_substreams = 4; |
| 37 | module_param(maximum_substreams, int, 0444); |
| 38 | MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory."); |
| 39 | |
| 40 | static 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 | */ |
| 49 | static int preallocate_pcm_pages(snd_pcm_substream_t *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 | */ |
| 81 | static void snd_pcm_lib_preallocate_dma_free(snd_pcm_substream_t *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(snd_pcm_substream_t *substream) |
| 101 | { |
| 102 | snd_pcm_lib_preallocate_dma_free(substream); |
| 103 | if (substream->proc_prealloc_entry) { |
| 104 | snd_info_unregister(substream->proc_prealloc_entry); |
| 105 | substream->proc_prealloc_entry = NULL; |
| 106 | } |
| 107 | return 0; |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm |
| 112 | * @pcm: the pcm instance |
| 113 | * |
| 114 | * Releases all the pre-allocated buffers on the given pcm. |
| 115 | * |
| 116 | * Returns zero if successful, or a negative error code on failure. |
| 117 | */ |
| 118 | int snd_pcm_lib_preallocate_free_for_all(snd_pcm_t *pcm) |
| 119 | { |
| 120 | snd_pcm_substream_t *substream; |
| 121 | int stream; |
| 122 | |
| 123 | for (stream = 0; stream < 2; stream++) |
| 124 | for (substream = pcm->streams[stream].substream; substream; substream = substream->next) |
| 125 | snd_pcm_lib_preallocate_free(substream); |
| 126 | return 0; |
| 127 | } |
| 128 | |
| 129 | /* |
| 130 | * read callback for prealloc proc file |
| 131 | * |
| 132 | * prints the current allocated size in kB. |
| 133 | */ |
| 134 | static void snd_pcm_lib_preallocate_proc_read(snd_info_entry_t *entry, |
| 135 | snd_info_buffer_t *buffer) |
| 136 | { |
| 137 | snd_pcm_substream_t *substream = (snd_pcm_substream_t *)entry->private_data; |
| 138 | snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024); |
| 139 | } |
| 140 | |
| 141 | /* |
| 142 | * write callback for prealloc proc file |
| 143 | * |
| 144 | * accepts the preallocation size in kB. |
| 145 | */ |
| 146 | static void snd_pcm_lib_preallocate_proc_write(snd_info_entry_t *entry, |
| 147 | snd_info_buffer_t *buffer) |
| 148 | { |
| 149 | snd_pcm_substream_t *substream = (snd_pcm_substream_t *)entry->private_data; |
| 150 | char line[64], str[64]; |
| 151 | size_t size; |
| 152 | struct snd_dma_buffer new_dmab; |
| 153 | |
| 154 | if (substream->runtime) { |
| 155 | buffer->error = -EBUSY; |
| 156 | return; |
| 157 | } |
| 158 | if (!snd_info_get_line(buffer, line, sizeof(line))) { |
| 159 | snd_info_get_str(str, line, sizeof(str)); |
| 160 | size = simple_strtoul(str, NULL, 10) * 1024; |
| 161 | if ((size != 0 && size < 8192) || size > substream->dma_max) { |
| 162 | buffer->error = -EINVAL; |
| 163 | return; |
| 164 | } |
| 165 | if (substream->dma_buffer.bytes == size) |
| 166 | return; |
| 167 | memset(&new_dmab, 0, sizeof(new_dmab)); |
| 168 | new_dmab.dev = substream->dma_buffer.dev; |
| 169 | if (size > 0) { |
| 170 | if (snd_dma_alloc_pages(substream->dma_buffer.dev.type, |
| 171 | substream->dma_buffer.dev.dev, |
| 172 | size, &new_dmab) < 0) { |
| 173 | buffer->error = -ENOMEM; |
| 174 | return; |
| 175 | } |
| 176 | substream->buffer_bytes_max = size; |
| 177 | } else { |
| 178 | substream->buffer_bytes_max = UINT_MAX; |
| 179 | } |
| 180 | if (substream->dma_buffer.area) |
| 181 | snd_dma_free_pages(&substream->dma_buffer); |
| 182 | substream->dma_buffer = new_dmab; |
| 183 | } else { |
| 184 | buffer->error = -EINVAL; |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | /* |
| 189 | * pre-allocate the buffer and create a proc file for the substream |
| 190 | */ |
| 191 | static int snd_pcm_lib_preallocate_pages1(snd_pcm_substream_t *substream, |
| 192 | size_t size, size_t max) |
| 193 | { |
| 194 | snd_info_entry_t *entry; |
| 195 | |
| 196 | if (size > 0 && preallocate_dma && substream->number < maximum_substreams) |
| 197 | preallocate_pcm_pages(substream, size); |
| 198 | |
| 199 | if (substream->dma_buffer.bytes > 0) |
| 200 | substream->buffer_bytes_max = substream->dma_buffer.bytes; |
| 201 | substream->dma_max = max; |
| 202 | if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) { |
| 203 | entry->c.text.read_size = 64; |
| 204 | entry->c.text.read = snd_pcm_lib_preallocate_proc_read; |
| 205 | entry->c.text.write_size = 64; |
| 206 | entry->c.text.write = snd_pcm_lib_preallocate_proc_write; |
Takashi Iwai | bd7bf04 | 2005-04-12 16:27:28 +0200 | [diff] [blame] | 207 | entry->mode |= S_IWUSR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 208 | entry->private_data = substream; |
| 209 | if (snd_info_register(entry) < 0) { |
| 210 | snd_info_free_entry(entry); |
| 211 | entry = NULL; |
| 212 | } |
| 213 | } |
| 214 | substream->proc_prealloc_entry = entry; |
| 215 | return 0; |
| 216 | } |
| 217 | |
| 218 | |
| 219 | /** |
| 220 | * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type |
| 221 | * @substream: the pcm substream instance |
| 222 | * @type: DMA type (SNDRV_DMA_TYPE_*) |
| 223 | * @data: DMA type dependant data |
| 224 | * @size: the requested pre-allocation size in bytes |
| 225 | * @max: the max. allowed pre-allocation size |
| 226 | * |
| 227 | * Do pre-allocation for the given DMA buffer type. |
| 228 | * |
| 229 | * When substream->dma_buf_id is set, the function tries to look for |
| 230 | * the reserved buffer, and the buffer is not freed but reserved at |
| 231 | * destruction time. The dma_buf_id must be unique for all systems |
| 232 | * (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id(). |
| 233 | * |
| 234 | * Returns zero if successful, or a negative error code on failure. |
| 235 | */ |
| 236 | int snd_pcm_lib_preallocate_pages(snd_pcm_substream_t *substream, |
| 237 | int type, struct device *data, |
| 238 | size_t size, size_t max) |
| 239 | { |
| 240 | substream->dma_buffer.dev.type = type; |
| 241 | substream->dma_buffer.dev.dev = data; |
| 242 | return snd_pcm_lib_preallocate_pages1(substream, size, max); |
| 243 | } |
| 244 | |
| 245 | /** |
| 246 | * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continous memory type (all substreams) |
Takashi Iwai | df8db93 | 2005-09-07 13:38:19 +0200 | [diff] [blame] | 247 | * @pcm: the pcm instance |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | * @type: DMA type (SNDRV_DMA_TYPE_*) |
| 249 | * @data: DMA type dependant data |
| 250 | * @size: the requested pre-allocation size in bytes |
| 251 | * @max: the max. allowed pre-allocation size |
| 252 | * |
| 253 | * Do pre-allocation to all substreams of the given pcm for the |
| 254 | * specified DMA type. |
| 255 | * |
| 256 | * Returns zero if successful, or a negative error code on failure. |
| 257 | */ |
| 258 | int snd_pcm_lib_preallocate_pages_for_all(snd_pcm_t *pcm, |
| 259 | int type, void *data, |
| 260 | size_t size, size_t max) |
| 261 | { |
| 262 | snd_pcm_substream_t *substream; |
| 263 | int stream, err; |
| 264 | |
| 265 | for (stream = 0; stream < 2; stream++) |
| 266 | for (substream = pcm->streams[stream].substream; substream; substream = substream->next) |
| 267 | if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0) |
| 268 | return err; |
| 269 | return 0; |
| 270 | } |
| 271 | |
| 272 | /** |
| 273 | * snd_pcm_sgbuf_ops_page - get the page struct at the given offset |
| 274 | * @substream: the pcm substream instance |
| 275 | * @offset: the buffer offset |
| 276 | * |
| 277 | * Returns the page struct at the given buffer offset. |
| 278 | * Used as the page callback of PCM ops. |
| 279 | */ |
| 280 | struct page *snd_pcm_sgbuf_ops_page(snd_pcm_substream_t *substream, unsigned long offset) |
| 281 | { |
| 282 | struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream); |
| 283 | |
| 284 | unsigned int idx = offset >> PAGE_SHIFT; |
| 285 | if (idx >= (unsigned int)sgbuf->pages) |
| 286 | return NULL; |
| 287 | return sgbuf->page_table[idx]; |
| 288 | } |
| 289 | |
| 290 | /** |
| 291 | * snd_pcm_lib_malloc_pages - allocate the DMA buffer |
| 292 | * @substream: the substream to allocate the DMA buffer to |
| 293 | * @size: the requested buffer size in bytes |
| 294 | * |
| 295 | * Allocates the DMA buffer on the BUS type given earlier to |
| 296 | * snd_pcm_lib_preallocate_xxx_pages(). |
| 297 | * |
| 298 | * Returns 1 if the buffer is changed, 0 if not changed, or a negative |
| 299 | * code on failure. |
| 300 | */ |
| 301 | int snd_pcm_lib_malloc_pages(snd_pcm_substream_t *substream, size_t size) |
| 302 | { |
| 303 | snd_pcm_runtime_t *runtime; |
| 304 | struct snd_dma_buffer *dmab = NULL; |
| 305 | |
| 306 | snd_assert(substream->dma_buffer.dev.type != SNDRV_DMA_TYPE_UNKNOWN, return -EINVAL); |
| 307 | snd_assert(substream != NULL, return -EINVAL); |
| 308 | runtime = substream->runtime; |
| 309 | snd_assert(runtime != NULL, return -EINVAL); |
| 310 | |
| 311 | if (runtime->dma_buffer_p) { |
| 312 | /* perphaps, we might free the large DMA memory region |
| 313 | to save some space here, but the actual solution |
| 314 | costs us less time */ |
| 315 | if (runtime->dma_buffer_p->bytes >= size) { |
| 316 | runtime->dma_bytes = size; |
| 317 | return 0; /* ok, do not change */ |
| 318 | } |
| 319 | snd_pcm_lib_free_pages(substream); |
| 320 | } |
| 321 | if (substream->dma_buffer.area != NULL && substream->dma_buffer.bytes >= size) { |
| 322 | dmab = &substream->dma_buffer; /* use the pre-allocated buffer */ |
| 323 | } else { |
Takashi Iwai | ca2c096 | 2005-09-09 14:20:23 +0200 | [diff] [blame^] | 324 | dmab = kzalloc(sizeof(*dmab), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | if (! dmab) |
| 326 | return -ENOMEM; |
| 327 | dmab->dev = substream->dma_buffer.dev; |
| 328 | if (snd_dma_alloc_pages(substream->dma_buffer.dev.type, |
| 329 | substream->dma_buffer.dev.dev, |
| 330 | size, dmab) < 0) { |
| 331 | kfree(dmab); |
| 332 | return -ENOMEM; |
| 333 | } |
| 334 | } |
| 335 | snd_pcm_set_runtime_buffer(substream, dmab); |
| 336 | runtime->dma_bytes = size; |
| 337 | return 1; /* area was changed */ |
| 338 | } |
| 339 | |
| 340 | /** |
| 341 | * snd_pcm_lib_free_pages - release the allocated DMA buffer. |
| 342 | * @substream: the substream to release the DMA buffer |
| 343 | * |
| 344 | * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages(). |
| 345 | * |
| 346 | * Returns zero if successful, or a negative error code on failure. |
| 347 | */ |
| 348 | int snd_pcm_lib_free_pages(snd_pcm_substream_t *substream) |
| 349 | { |
| 350 | snd_pcm_runtime_t *runtime; |
| 351 | |
| 352 | snd_assert(substream != NULL, return -EINVAL); |
| 353 | runtime = substream->runtime; |
| 354 | snd_assert(runtime != NULL, return -EINVAL); |
| 355 | if (runtime->dma_area == NULL) |
| 356 | return 0; |
| 357 | if (runtime->dma_buffer_p != &substream->dma_buffer) { |
| 358 | /* it's a newly allocated buffer. release it now. */ |
| 359 | snd_dma_free_pages(runtime->dma_buffer_p); |
| 360 | kfree(runtime->dma_buffer_p); |
| 361 | } |
| 362 | snd_pcm_set_runtime_buffer(substream, NULL); |
| 363 | return 0; |
| 364 | } |