diff options
Diffstat (limited to 'sound/core/pcm_memory.c')
| -rw-r--r-- | sound/core/pcm_memory.c | 563 |
1 files changed, 563 insertions, 0 deletions
diff --git a/sound/core/pcm_memory.c b/sound/core/pcm_memory.c new file mode 100644 index 000000000..a0b951471 --- /dev/null +++ b/sound/core/pcm_memory.c @@ -0,0 +1,563 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Digital Audio (PCM) abstract layer + * Copyright (c) by Jaroslav Kysela <perex@perex.cz> + */ + +#include <linux/io.h> +#include <linux/time.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/moduleparam.h> +#include <linux/vmalloc.h> +#include <linux/export.h> +#include <sound/core.h> +#include <sound/pcm.h> +#include <sound/info.h> +#include <sound/initval.h> +#include "pcm_local.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; + +static unsigned long max_alloc_per_card = 32UL * 1024UL * 1024UL; +module_param(max_alloc_per_card, ulong, 0644); +MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card."); + +static void __update_allocated_size(struct snd_card *card, ssize_t bytes) +{ + card->total_pcm_alloc_bytes += bytes; +} + +static void update_allocated_size(struct snd_card *card, ssize_t bytes) +{ + mutex_lock(&card->memory_mutex); + __update_allocated_size(card, bytes); + mutex_unlock(&card->memory_mutex); +} + +static void decrease_allocated_size(struct snd_card *card, size_t bytes) +{ + mutex_lock(&card->memory_mutex); + WARN_ON(card->total_pcm_alloc_bytes < bytes); + __update_allocated_size(card, -(ssize_t)bytes); + mutex_unlock(&card->memory_mutex); +} + +static int do_alloc_pages(struct snd_card *card, int type, struct device *dev, + int str, size_t size, struct snd_dma_buffer *dmab) +{ + enum dma_data_direction dir; + int err; + + /* check and reserve the requested size */ + mutex_lock(&card->memory_mutex); + if (max_alloc_per_card && + card->total_pcm_alloc_bytes + size > max_alloc_per_card) { + mutex_unlock(&card->memory_mutex); + return -ENOMEM; + } + __update_allocated_size(card, size); + mutex_unlock(&card->memory_mutex); + + if (str == SNDRV_PCM_STREAM_PLAYBACK) + dir = DMA_TO_DEVICE; + else + dir = DMA_FROM_DEVICE; + err = snd_dma_alloc_dir_pages(type, dev, dir, size, dmab); + if (!err) { + /* the actual allocation size might be bigger than requested, + * and we need to correct the account + */ + if (dmab->bytes != size) + update_allocated_size(card, dmab->bytes - size); + } else { + /* take back on allocation failure */ + decrease_allocated_size(card, size); + } + return err; +} + +static void do_free_pages(struct snd_card *card, struct snd_dma_buffer *dmab) +{ + if (!dmab->area) + return; + decrease_allocated_size(card, dmab->bytes); + snd_dma_free_pages(dmab); + dmab->area = NULL; +} + +/* + * 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(struct snd_pcm_substream *substream, + size_t size, bool no_fallback) +{ + struct snd_dma_buffer *dmab = &substream->dma_buffer; + struct snd_card *card = substream->pcm->card; + size_t orig_size = size; + int err; + + do { + err = do_alloc_pages(card, dmab->dev.type, dmab->dev.dev, + substream->stream, size, dmab); + if (err != -ENOMEM) + return err; + if (no_fallback) + break; + size >>= 1; + } while (size >= snd_minimum_buffer); + dmab->bytes = 0; /* tell error */ + pr_warn("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n", + substream->pcm->card->number, substream->pcm->device, + substream->stream ? 'c' : 'p', substream->number, + substream->pcm->name, orig_size); + return -ENOMEM; +} + +/** + * 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. + */ +void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream) +{ + do_free_pages(substream->pcm->card, &substream->dma_buffer); +} + +/** + * 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. + */ +void snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm) +{ + struct snd_pcm_substream *substream; + int stream; + + for_each_pcm_substream(pcm, stream, substream) + snd_pcm_lib_preallocate_free(substream); +} +EXPORT_SYMBOL(snd_pcm_lib_preallocate_free_for_all); + +#ifdef CONFIG_SND_VERBOSE_PROCFS +/* + * read callback for prealloc proc file + * + * prints the current allocated size in kB. + */ +static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry, + struct snd_info_buffer *buffer) +{ + struct snd_pcm_substream *substream = entry->private_data; + snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024); +} + +/* + * read callback for prealloc_max proc file + * + * prints the maximum allowed size in kB. + */ +static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry, + struct snd_info_buffer *buffer) +{ + struct snd_pcm_substream *substream = entry->private_data; + snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024); +} + +/* + * write callback for prealloc proc file + * + * accepts the preallocation size in kB. + */ +static void snd_pcm_lib_preallocate_proc_write(struct snd_info_entry *entry, + struct snd_info_buffer *buffer) +{ + struct snd_pcm_substream *substream = entry->private_data; + struct snd_card *card = substream->pcm->card; + char line[64], str[64]; + size_t size; + struct snd_dma_buffer new_dmab; + + mutex_lock(&substream->pcm->open_mutex); + if (substream->runtime) { + buffer->error = -EBUSY; + goto unlock; + } + 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; + goto unlock; + } + if (substream->dma_buffer.bytes == size) + goto unlock; + memset(&new_dmab, 0, sizeof(new_dmab)); + new_dmab.dev = substream->dma_buffer.dev; + if (size > 0) { + if (do_alloc_pages(card, + substream->dma_buffer.dev.type, + substream->dma_buffer.dev.dev, + substream->stream, + size, &new_dmab) < 0) { + buffer->error = -ENOMEM; + pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n", + substream->pcm->card->number, substream->pcm->device, + substream->stream ? 'c' : 'p', substream->number, + substream->pcm->name, size); + goto unlock; + } + substream->buffer_bytes_max = size; + } else { + substream->buffer_bytes_max = UINT_MAX; + } + if (substream->dma_buffer.area) + do_free_pages(card, &substream->dma_buffer); + substream->dma_buffer = new_dmab; + } else { + buffer->error = -EINVAL; + } + unlock: + mutex_unlock(&substream->pcm->open_mutex); +} + +static inline void preallocate_info_init(struct snd_pcm_substream *substream) +{ + struct snd_info_entry *entry; + + entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", + substream->proc_root); + if (entry) { + snd_info_set_text_ops(entry, substream, + snd_pcm_lib_preallocate_proc_read); + entry->c.text.write = snd_pcm_lib_preallocate_proc_write; + entry->mode |= 0200; + } + entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", + substream->proc_root); + if (entry) + snd_info_set_text_ops(entry, substream, + snd_pcm_lib_preallocate_max_proc_read); +} + +#else /* !CONFIG_SND_VERBOSE_PROCFS */ +static inline void preallocate_info_init(struct snd_pcm_substream *substream) +{ +} +#endif /* CONFIG_SND_VERBOSE_PROCFS */ + +/* + * pre-allocate the buffer and create a proc file for the substream + */ +static int preallocate_pages(struct snd_pcm_substream *substream, + int type, struct device *data, + size_t size, size_t max, bool managed) +{ + int err; + + if (snd_BUG_ON(substream->dma_buffer.dev.type)) + return -EINVAL; + + substream->dma_buffer.dev.type = type; + substream->dma_buffer.dev.dev = data; + + if (size > 0) { + if (!max) { + /* no fallback, only also inform -ENOMEM */ + err = preallocate_pcm_pages(substream, size, true); + if (err < 0) + return err; + } else if (preallocate_dma && + substream->number < maximum_substreams) { + err = preallocate_pcm_pages(substream, size, false); + if (err < 0 && err != -ENOMEM) + return err; + } + } + + if (substream->dma_buffer.bytes > 0) + substream->buffer_bytes_max = substream->dma_buffer.bytes; + substream->dma_max = max; + if (max > 0) + preallocate_info_init(substream); + if (managed) + substream->managed_buffer_alloc = 1; + return 0; +} + +static int preallocate_pages_for_all(struct snd_pcm *pcm, int type, + void *data, size_t size, size_t max, + bool managed) +{ + struct snd_pcm_substream *substream; + int stream, err; + + for_each_pcm_substream(pcm, stream, substream) { + err = preallocate_pages(substream, type, data, size, max, managed); + if (err < 0) + return err; + } + 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 dependent 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. + */ +void snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream, + int type, struct device *data, + size_t size, size_t max) +{ + preallocate_pages(substream, type, data, size, max, false); +} +EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages); + +/** + * snd_pcm_lib_preallocate_pages_for_all - pre-allocation for continuous memory type (all substreams) + * @pcm: the pcm instance + * @type: DMA type (SNDRV_DMA_TYPE_*) + * @data: DMA type dependent 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. + */ +void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm, + int type, void *data, + size_t size, size_t max) +{ + preallocate_pages_for_all(pcm, type, data, size, max, false); +} +EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all); + +/** + * snd_pcm_set_managed_buffer - set up buffer management for a substream + * @substream: the pcm substream instance + * @type: DMA type (SNDRV_DMA_TYPE_*) + * @data: DMA type dependent 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, and set the managed + * buffer allocation mode to the given substream. + * In this mode, PCM core will allocate a buffer automatically before PCM + * hw_params ops call, and release the buffer after PCM hw_free ops call + * as well, so that the driver doesn't need to invoke the allocation and + * the release explicitly in its callback. + * When a buffer is actually allocated before the PCM hw_params call, it + * turns on the runtime buffer_changed flag for drivers changing their h/w + * parameters accordingly. + * + * When @size is non-zero and @max is zero, this tries to allocate for only + * the exact buffer size without fallback, and may return -ENOMEM. + * Otherwise, the function tries to allocate smaller chunks if the allocation + * fails. This is the behavior of snd_pcm_set_fixed_buffer(). + * + * When both @size and @max are zero, the function only sets up the buffer + * for later dynamic allocations. It's used typically for buffers with + * SNDRV_DMA_TYPE_VMALLOC type. + * + * Upon successful buffer allocation and setup, the function returns 0. + * + * Return: zero if successful, or a negative error code + */ +int snd_pcm_set_managed_buffer(struct snd_pcm_substream *substream, int type, + struct device *data, size_t size, size_t max) +{ + return preallocate_pages(substream, type, data, size, max, true); +} +EXPORT_SYMBOL(snd_pcm_set_managed_buffer); + +/** + * snd_pcm_set_managed_buffer_all - set up buffer management for all substreams + * for all substreams + * @pcm: the pcm instance + * @type: DMA type (SNDRV_DMA_TYPE_*) + * @data: DMA type dependent 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 and size, and set the managed_buffer_alloc flag to each substream. + * + * Return: zero if successful, or a negative error code + */ +int snd_pcm_set_managed_buffer_all(struct snd_pcm *pcm, int type, + struct device *data, + size_t size, size_t max) +{ + return preallocate_pages_for_all(pcm, type, data, size, max, true); +} +EXPORT_SYMBOL(snd_pcm_set_managed_buffer_all); + +/** + * 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(). + * + * Return: 1 if the buffer is changed, 0 if not changed, or a negative + * code on failure. + */ +int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size) +{ + struct snd_card *card; + struct snd_pcm_runtime *runtime; + struct snd_dma_buffer *dmab = NULL; + + if (PCM_RUNTIME_CHECK(substream)) + return -EINVAL; + if (snd_BUG_ON(substream->dma_buffer.dev.type == + SNDRV_DMA_TYPE_UNKNOWN)) + return -EINVAL; + runtime = substream->runtime; + card = substream->pcm->card; + + 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 { + /* dma_max=0 means the fixed size preallocation */ + if (substream->dma_buffer.area && !substream->dma_max) + return -ENOMEM; + dmab = kzalloc(sizeof(*dmab), GFP_KERNEL); + if (! dmab) + return -ENOMEM; + dmab->dev = substream->dma_buffer.dev; + if (do_alloc_pages(card, + substream->dma_buffer.dev.type, + substream->dma_buffer.dev.dev, + substream->stream, + size, dmab) < 0) { + kfree(dmab); + pr_debug("ALSA pcmC%dD%d%c,%d:%s: cannot preallocate for size %zu\n", + substream->pcm->card->number, substream->pcm->device, + substream->stream ? 'c' : 'p', substream->number, + substream->pcm->name, size); + return -ENOMEM; + } + } + snd_pcm_set_runtime_buffer(substream, dmab); + runtime->dma_bytes = size; + return 1; /* area was changed */ +} +EXPORT_SYMBOL(snd_pcm_lib_malloc_pages); + +/** + * 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(). + * + * Return: Zero if successful, or a negative error code on failure. + */ +int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream) +{ + struct snd_pcm_runtime *runtime; + + if (PCM_RUNTIME_CHECK(substream)) + return -EINVAL; + runtime = substream->runtime; + if (runtime->dma_area == NULL) + return 0; + if (runtime->dma_buffer_p != &substream->dma_buffer) { + struct snd_card *card = substream->pcm->card; + + /* it's a newly allocated buffer. release it now. */ + do_free_pages(card, runtime->dma_buffer_p); + kfree(runtime->dma_buffer_p); + } + snd_pcm_set_runtime_buffer(substream, NULL); + return 0; +} +EXPORT_SYMBOL(snd_pcm_lib_free_pages); + +int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream, + size_t size, gfp_t gfp_flags) +{ + struct snd_pcm_runtime *runtime; + + if (PCM_RUNTIME_CHECK(substream)) + return -EINVAL; + runtime = substream->runtime; + if (runtime->dma_area) { + if (runtime->dma_bytes >= size) + return 0; /* already large enough */ + vfree(runtime->dma_area); + } + runtime->dma_area = __vmalloc(size, gfp_flags); + if (!runtime->dma_area) + return -ENOMEM; + runtime->dma_bytes = size; + return 1; +} +EXPORT_SYMBOL(_snd_pcm_lib_alloc_vmalloc_buffer); + +/** + * snd_pcm_lib_free_vmalloc_buffer - free vmalloc buffer + * @substream: the substream with a buffer allocated by + * snd_pcm_lib_alloc_vmalloc_buffer() + * + * Return: Zero if successful, or a negative error code on failure. + */ +int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream) +{ + struct snd_pcm_runtime *runtime; + + if (PCM_RUNTIME_CHECK(substream)) + return -EINVAL; + runtime = substream->runtime; + vfree(runtime->dma_area); + runtime->dma_area = NULL; + return 0; +} +EXPORT_SYMBOL(snd_pcm_lib_free_vmalloc_buffer); + +/** + * snd_pcm_lib_get_vmalloc_page - map vmalloc buffer offset to page struct + * @substream: the substream with a buffer allocated by + * snd_pcm_lib_alloc_vmalloc_buffer() + * @offset: offset in the buffer + * + * This function is to be used as the page callback in the PCM ops. + * + * Return: The page struct, or %NULL on failure. + */ +struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream, + unsigned long offset) +{ + return vmalloc_to_page(substream->runtime->dma_area + offset); +} +EXPORT_SYMBOL(snd_pcm_lib_get_vmalloc_page); |