diff options
Diffstat (limited to 'sound/core/pcm_memory.c')
| -rw-r--r-- | sound/core/pcm_memory.c | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/sound/core/pcm_memory.c b/sound/core/pcm_memory.c new file mode 100644 index 00000000000..f1d5f7a6ee0 --- /dev/null +++ b/sound/core/pcm_memory.c @@ -0,0 +1,363 @@ +/* + * Digital Audio (PCM) abstract layer + * Copyright (c) by Jaroslav Kysela <perex@suse.cz> + * + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include <sound/driver.h> +#include <asm/io.h> +#include <linux/time.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <sound/core.h> +#include <sound/pcm.h> +#include <sound/info.h> +#include <sound/initval.h> + +static int preallocate_dma = 1; +module_param(preallocate_dma, int, 0444); +MODULE_PARM_DESC(preallocate_dma, "Preallocate DMA memory when the PCM devices are initialized."); + +static int maximum_substreams = 4; +module_param(maximum_substreams, int, 0444); +MODULE_PARM_DESC(maximum_substreams, "Maximum substreams with preallocated DMA memory."); + +static const size_t snd_minimum_buffer = 16384; + + +/* + * try to allocate as the large pages as possible. + * stores the resultant memory size in *res_size. + * + * the minimum size is snd_minimum_buffer. it should be power of 2. + */ +static int preallocate_pcm_pages(snd_pcm_substream_t *substream, size_t size) +{ + struct snd_dma_buffer *dmab = &substream->dma_buffer; + int err; + + snd_assert(size > 0, return -EINVAL); + + /* already reserved? */ + if (snd_dma_get_reserved_buf(dmab, substream->dma_buf_id) > 0) { + if (dmab->bytes >= size) + return 0; /* yes */ + /* no, free the reserved block */ + snd_dma_free_pages(dmab); + dmab->bytes = 0; + } + + do { + if ((err = snd_dma_alloc_pages(dmab->dev.type, dmab->dev.dev, + size, dmab)) < 0) { + if (err != -ENOMEM) + return err; /* fatal error */ + } else + return 0; + size >>= 1; + } while (size >= snd_minimum_buffer); + dmab->bytes = 0; /* tell error */ + return 0; +} + +/* + * release the preallocated buffer if not yet done. + */ +static void snd_pcm_lib_preallocate_dma_free(snd_pcm_substream_t *substream) +{ + if (substream->dma_buffer.area == NULL) + return; + if (substream->dma_buf_id) + snd_dma_reserve_buf(&substream->dma_buffer, substream->dma_buf_id); + else + snd_dma_free_pages(&substream->dma_buffer); + substream->dma_buffer.area = NULL; +} + +/** + * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream. + * @substream: the pcm substream instance + * + * Releases the pre-allocated buffer of the given substream. + * + * Returns zero if successful, or a negative error code on failure. + */ +int snd_pcm_lib_preallocate_free(snd_pcm_substream_t *substream) +{ + snd_pcm_lib_preallocate_dma_free(substream); + if (substream->proc_prealloc_entry) { + snd_info_unregister(substream->proc_prealloc_entry); + substream->proc_prealloc_entry = NULL; + } + return 0; +} + +/** + * snd_pcm_lib_preallocate_free_for_all - release all pre-allocated buffers on the pcm + * @pcm: the pcm instance + * + * Releases all the pre-allocated buffers on the given pcm. + * + * Returns zero if successful, or a negative error code on failure. + */ +int snd_pcm_lib_preallocate_free_for_all(snd_pcm_t *pcm) +{ + snd_pcm_substream_t *substream; + int stream; + + for (stream = 0; stream < 2; stream++) + for (substream = pcm->streams[stream].substream; substream; substream = substream->next) + snd_pcm_lib_preallocate_free(substream); + return 0; +} + +/* + * read callback for prealloc proc file + * + * prints the current allocated size in kB. + */ +static void snd_pcm_lib_preallocate_proc_read(snd_info_entry_t *entry, + snd_info_buffer_t *buffer) +{ + snd_pcm_substream_t *substream = (snd_pcm_substream_t *)entry->private_data; + snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024); +} + +/* + * write callback for prealloc proc file + * + * accepts the preallocation size in kB. + */ +static void snd_pcm_lib_preallocate_proc_write(snd_info_entry_t *entry, + snd_info_buffer_t *buffer) +{ + snd_pcm_substream_t *substream = (snd_pcm_substream_t *)entry->private_data; + char line[64], str[64]; + size_t size; + struct snd_dma_buffer new_dmab; + + if (substream->runtime) { + buffer->error = -EBUSY; + return; + } + if (!snd_info_get_line(buffer, line, sizeof(line))) { + snd_info_get_str(str, line, sizeof(str)); + size = simple_strtoul(str, NULL, 10) * 1024; + if ((size != 0 && size < 8192) || size > substream->dma_max) { + buffer->error = -EINVAL; + return; + } + if (substream->dma_buffer.bytes == size) + return; + memset(&new_dmab, 0, sizeof(new_dmab)); + new_dmab.dev = substream->dma_buffer.dev; + if (size > 0) { + if (snd_dma_alloc_pages(substream->dma_buffer.dev.type, + substream->dma_buffer.dev.dev, + size, &new_dmab) < 0) { + buffer->error = -ENOMEM; + return; + } + substream->buffer_bytes_max = size; + } else { + substream->buffer_bytes_max = UINT_MAX; + } + if (substream->dma_buffer.area) + snd_dma_free_pages(&substream->dma_buffer); + substream->dma_buffer = new_dmab; + } else { + buffer->error = -EINVAL; + } +} + +/* + * pre-allocate the buffer and create a proc file for the substream + */ +static int snd_pcm_lib_preallocate_pages1(snd_pcm_substream_t *substream, + size_t size, size_t max) +{ + snd_info_entry_t *entry; + + if (size > 0 && preallocate_dma && substream->number < maximum_substreams) + preallocate_pcm_pages(substream, size); + + if (substream->dma_buffer.bytes > 0) + substream->buffer_bytes_max = substream->dma_buffer.bytes; + substream->dma_max = max; + if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) { + entry->c.text.read_size = 64; + entry->c.text.read = snd_pcm_lib_preallocate_proc_read; + entry->c.text.write_size = 64; + entry->c.text.write = snd_pcm_lib_preallocate_proc_write; + entry->private_data = substream; + if (snd_info_register(entry) < 0) { + snd_info_free_entry(entry); + entry = NULL; + } + } + substream->proc_prealloc_entry = entry; + return 0; +} + + +/** + * snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type + * @substream: the pcm substream instance + * @type: DMA type (SNDRV_DMA_TYPE_*) + * @data: DMA type dependant data + * @size: the requested pre-allocation size in bytes + * @max: the max. allowed pre-allocation size + * + * Do pre-allocation for the given DMA buffer type. + * + * When substream->dma_buf_id is set, the function tries to look for + * the reserved buffer, and the buffer is not freed but reserved at + * destruction time. The dma_buf_id must be unique for all systems + * (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id(). + * + * Returns zero if successful, or a negative error code on failure. + */ +int snd_pcm_lib_preallocate_pages(snd_pcm_substream_t *substream, + int type, struct device *data, + size_t size, size_t max) +{ + substream->dma_buffer.dev.type = type; + substream->dma_buffer.dev.dev = data; + return snd_pcm_lib_preallocate_pages1(substream, size, max); +} + +/** + * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continous memory type (all substreams) + * @substream: the pcm substream instance + * @type: DMA type (SNDRV_DMA_TYPE_*) + * @data: DMA type dependant data + * @size: the requested pre-allocation size in bytes + * @max: the max. allowed pre-allocation size + * + * Do pre-allocation to all substreams of the given pcm for the + * specified DMA type. + * + * Returns zero if successful, or a negative error code on failure. + */ +int snd_pcm_lib_preallocate_pages_for_all(snd_pcm_t *pcm, + int type, void *data, + size_t size, size_t max) +{ + snd_pcm_substream_t *substream; + int stream, err; + + for (stream = 0; stream < 2; stream++) + for (substream = pcm->streams[stream].substream; substream; substream = substream->next) + if ((err = snd_pcm_lib_preallocate_pages(substream, type, data, size, max)) < 0) + return err; + return 0; +} + +/** + * snd_pcm_sgbuf_ops_page - get the page struct at the given offset + * @substream: the pcm substream instance + * @offset: the buffer offset + * + * Returns the page struct at the given buffer offset. + * Used as the page callback of PCM ops. + */ +struct page *snd_pcm_sgbuf_ops_page(snd_pcm_substream_t *substream, unsigned long offset) +{ + struct snd_sg_buf *sgbuf = snd_pcm_substream_sgbuf(substream); + + unsigned int idx = offset >> PAGE_SHIFT; + if (idx >= (unsigned int)sgbuf->pages) + return NULL; + return sgbuf->page_table[idx]; +} + +/** + * snd_pcm_lib_malloc_pages - allocate the DMA buffer + * @substream: the substream to allocate the DMA buffer to + * @size: the requested buffer size in bytes + * + * Allocates the DMA buffer on the BUS type given earlier to + * snd_pcm_lib_preallocate_xxx_pages(). + * + * Returns 1 if the buffer is changed, 0 if not changed, or a negative + * code on failure. + */ +int snd_pcm_lib_malloc_pages(snd_pcm_substream_t *substream, size_t size) +{ + snd_pcm_runtime_t *runtime; + struct snd_dma_buffer *dmab = NULL; + + snd_assert(substream->dma_buffer.dev.type != SNDRV_DMA_TYPE_UNKNOWN, return -EINVAL); + snd_assert(substream != NULL, return -EINVAL); + runtime = substream->runtime; + snd_assert(runtime != NULL, return -EINVAL); + + if (runtime->dma_buffer_p) { + /* perphaps, we might free the large DMA memory region + to save some space here, but the actual solution + costs us less time */ + if (runtime->dma_buffer_p->bytes >= size) { + runtime->dma_bytes = size; + return 0; /* ok, do not change */ + } + snd_pcm_lib_free_pages(substream); + } + if (substream->dma_buffer.area != NULL && substream->dma_buffer.bytes >= size) { + dmab = &substream->dma_buffer; /* use the pre-allocated buffer */ + } else { + dmab = kcalloc(1, sizeof(*dmab), GFP_KERNEL); + if (! dmab) + return -ENOMEM; + dmab->dev = substream->dma_buffer.dev; + if (snd_dma_alloc_pages(substream->dma_buffer.dev.type, + substream->dma_buffer.dev.dev, + size, dmab) < 0) { + kfree(dmab); + return -ENOMEM; + } + } + snd_pcm_set_runtime_buffer(substream, dmab); + runtime->dma_bytes = size; + return 1; /* area was changed */ +} + +/** + * snd_pcm_lib_free_pages - release the allocated DMA buffer. + * @substream: the substream to release the DMA buffer + * + * Releases the DMA buffer allocated via snd_pcm_lib_malloc_pages(). + * + * Returns zero if successful, or a negative error code on failure. + */ +int snd_pcm_lib_free_pages(snd_pcm_substream_t *substream) +{ + snd_pcm_runtime_t *runtime; + + snd_assert(substream != NULL, return -EINVAL); + runtime = substream->runtime; + snd_assert(runtime != NULL, return -EINVAL); + if (runtime->dma_area == NULL) + return 0; + if (runtime->dma_buffer_p != &substream->dma_buffer) { + /* it's a newly allocated buffer. release it now. */ + snd_dma_free_pages(runtime->dma_buffer_p); + kfree(runtime->dma_buffer_p); + } + snd_pcm_set_runtime_buffer(substream, NULL); + return 0; +} |