From 427ae2689db0fb6377e39e63fae2991223cdd9e7 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Thu, 15 Jul 2021 09:58:23 +0200 Subject: ALSA: core: Add device-managed page allocator helper 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. Link: https://lore.kernel.org/r/20210715075941.23332-2-tiwai@suse.de Signed-off-by: Takashi Iwai --- sound/core/memalloc.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) (limited to 'sound/core/memalloc.c') 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 -- cgit