This is a preparation for allowing devres usages more widely in various sound drivers. As a first step, this patch adds a new allocator function, snd_devm_alloc_pages(), to manage the allocated pages via devres, so that the pages will be automagically released as device unbinding.
Unlike the old snd_dma_alloc_pages(), the new function returns directly the snd_dma_buffer pointer. The caller needs NULL-check for the allocation error appropriately.
Also, since a real device pointer is mandatory for devres, SNDRV_DMA_TYPE_CONTINUOUS or SNDRV_DMA_TYPE_VMALLOC type can't be used for this function.
Signed-off-by: Takashi Iwai tiwai@suse.de --- include/sound/memalloc.h | 4 ++++ sound/core/memalloc.c | 46 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 50 insertions(+)
diff --git a/include/sound/memalloc.h b/include/sound/memalloc.h index 44d87775b352..d22c9387b2ba 100644 --- a/include/sound/memalloc.h +++ b/include/sound/memalloc.h @@ -79,5 +79,9 @@ struct page *snd_sgbuf_get_page(struct snd_dma_buffer *dmab, size_t offset); unsigned int snd_sgbuf_get_chunk_size(struct snd_dma_buffer *dmab, unsigned int ofs, unsigned int size);
+/* device-managed memory allocator */ +struct snd_dma_buffer *snd_devm_alloc_pages(struct device *dev, int type, + size_t size); + #endif /* __SOUND_MEMALLOC_H */
diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c index 83b79edfa52d..3a78fdad1ab4 100644 --- a/sound/core/memalloc.c +++ b/sound/core/memalloc.c @@ -127,6 +127,52 @@ void snd_dma_free_pages(struct snd_dma_buffer *dmab) } EXPORT_SYMBOL(snd_dma_free_pages);
+/* called by devres */ +static void __snd_release_pages(struct device *dev, void *res) +{ + snd_dma_free_pages(res); +} + +/** + * snd_devm_alloc_pages - allocate the buffer and manage with devres + * @dev: the device pointer + * @type: the DMA buffer type + * @size: the buffer size to allocate + * + * Allocate buffer pages depending on the given type and manage using devres. + * The pages will be released automatically at the device removal. + * + * Unlike snd_dma_alloc_pages(), this function requires the real device pointer, + * hence it can't work with SNDRV_DMA_TYPE_CONTINUOUS or + * SNDRV_DMA_TYPE_VMALLOC type. + * + * The function returns the snd_dma_buffer object at success, or NULL if failed. + */ +struct snd_dma_buffer * +snd_devm_alloc_pages(struct device *dev, int type, size_t size) +{ + struct snd_dma_buffer *dmab; + int err; + + if (WARN_ON(type == SNDRV_DMA_TYPE_CONTINUOUS || + type == SNDRV_DMA_TYPE_VMALLOC)) + return NULL; + + dmab = devres_alloc(__snd_release_pages, sizeof(*dmab), GFP_KERNEL); + if (!dmab) + return NULL; + + err = snd_dma_alloc_pages(type, dev, size, dmab); + if (err < 0) { + devres_free(dmab); + return NULL; + } + + devres_add(dev, dmab); + return dmab; +} +EXPORT_SYMBOL_GPL(snd_devm_alloc_pages); + /** * snd_dma_buffer_mmap - perform mmap of the given DMA buffer * @dmab: buffer allocation information