--- /dev/null
+/*
+ * Digital Audio (PCM) abstract layer
+ * Copyright (c) by Jaroslav Kysela <perex@perex.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 <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>
+
+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(struct snd_pcm_substream *substream, size_t size)
+{
+ struct snd_dma_buffer *dmab = &substream->dma_buffer;
+ size_t orig_size = size;
+ int err;
+
+ 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 */
+ 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 0;
+}
+
+/*
+ * release the preallocated buffer if not yet done.
+ */
+static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
+{
+ if (substream->dma_buffer.area == NULL)
+ return;
+ 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.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
+{
+ snd_pcm_lib_preallocate_dma_free(substream);
+#ifdef CONFIG_SND_VERBOSE_PROCFS
+ snd_info_free_entry(substream->proc_prealloc_max_entry);
+ substream->proc_prealloc_max_entry = NULL;
+ snd_info_free_entry(substream->proc_prealloc_entry);
+ substream->proc_prealloc_entry = NULL;
+#endif
+ 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.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm)
+{
+ struct snd_pcm_substream *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;
+}
+
+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;
+ 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;
+ }
+}
+
+static inline void preallocate_info_init(struct snd_pcm_substream *substream)
+{
+ struct snd_info_entry *entry;
+
+ if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc", substream->proc_root)) != NULL) {
+ entry->c.text.read = snd_pcm_lib_preallocate_proc_read;
+ entry->c.text.write = snd_pcm_lib_preallocate_proc_write;
+ entry->mode |= S_IWUSR;
+ entry->private_data = substream;
+ if (snd_info_register(entry) < 0) {
+ snd_info_free_entry(entry);
+ entry = NULL;
+ }
+ }
+ substream->proc_prealloc_entry = entry;
+ if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
+ entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
+ entry->private_data = substream;
+ if (snd_info_register(entry) < 0) {
+ snd_info_free_entry(entry);
+ entry = NULL;
+ }
+ }
+ substream->proc_prealloc_max_entry = entry;
+}
+
+#else /* !CONFIG_SND_VERBOSE_PROCFS */
+#define preallocate_info_init(s)
+#endif /* CONFIG_SND_VERBOSE_PROCFS */
+
+/*
+ * pre-allocate the buffer and create a proc file for the substream
+ */
+static int snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
+ size_t size, size_t max)
+{
+
+ 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;
+ preallocate_info_init(substream);
+ 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.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *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);
+}
+
+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.
+ *
+ * Return: Zero if successful, or a negative error code on failure.
+ */
+int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
+ int type, void *data,
+ size_t size, size_t max)
+{
+ struct snd_pcm_substream *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;
+}
+
+EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
+
+#ifdef CONFIG_SND_DMA_SGBUF
+/**
+ * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
+ * @substream: the pcm substream instance
+ * @offset: the buffer offset
+ *
+ * Used as the page callback of PCM ops.
+ *
+ * Return: The page struct at the given buffer offset. %NULL on failure.
+ */
+struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *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];
+}
+
+EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
+#endif /* CONFIG_SND_DMA_SGBUF */
+
+/**
+ * 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_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;
+
+ 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 = kzalloc(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 */
+}
+
+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) {
+ /* 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;
+}
+
+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, PAGE_KERNEL);
+ 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);
Code Review / kvmfornfv.git / blobdiff