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@xxxxxxx>
---
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
--
2.26.2
