linux/include/sound/memalloc.h
Takashi Iwai 427ae2689d 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 <tiwai@suse.de>
2021-07-19 16:16:32 +02:00

88 lines
2.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
* Takashi Iwai <tiwai@suse.de>
*
* Generic memory allocators
*/
#ifndef __SOUND_MEMALLOC_H
#define __SOUND_MEMALLOC_H
#include <asm/page.h>
struct device;
struct vm_area_struct;
/*
* buffer device info
*/
struct snd_dma_device {
int type; /* SNDRV_DMA_TYPE_XXX */
struct device *dev; /* generic device */
};
#define snd_dma_continuous_data(x) ((struct device *)(__force unsigned long)(x))
/*
* buffer types
*/
#define SNDRV_DMA_TYPE_UNKNOWN 0 /* not defined */
#define SNDRV_DMA_TYPE_CONTINUOUS 1 /* continuous no-DMA memory */
#define SNDRV_DMA_TYPE_DEV 2 /* generic device continuous */
#define SNDRV_DMA_TYPE_DEV_UC 5 /* continuous non-cahced */
#ifdef CONFIG_SND_DMA_SGBUF
#define SNDRV_DMA_TYPE_DEV_SG 3 /* generic device SG-buffer */
#define SNDRV_DMA_TYPE_DEV_UC_SG 6 /* SG non-cached */
#else
#define SNDRV_DMA_TYPE_DEV_SG SNDRV_DMA_TYPE_DEV /* no SG-buf support */
#define SNDRV_DMA_TYPE_DEV_UC_SG SNDRV_DMA_TYPE_DEV_UC
#endif
#ifdef CONFIG_GENERIC_ALLOCATOR
#define SNDRV_DMA_TYPE_DEV_IRAM 4 /* generic device iram-buffer */
#else
#define SNDRV_DMA_TYPE_DEV_IRAM SNDRV_DMA_TYPE_DEV
#endif
#define SNDRV_DMA_TYPE_VMALLOC 7 /* vmalloc'ed buffer */
/*
* info for buffer allocation
*/
struct snd_dma_buffer {
struct snd_dma_device dev; /* device type */
unsigned char *area; /* virtual pointer */
dma_addr_t addr; /* physical address */
size_t bytes; /* buffer size in bytes */
void *private_data; /* private for allocator; don't touch */
};
/*
* return the pages matching with the given byte size
*/
static inline unsigned int snd_sgbuf_aligned_pages(size_t size)
{
return (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
}
/* allocate/release a buffer */
int snd_dma_alloc_pages(int type, struct device *dev, size_t size,
struct snd_dma_buffer *dmab);
int snd_dma_alloc_pages_fallback(int type, struct device *dev, size_t size,
struct snd_dma_buffer *dmab);
void snd_dma_free_pages(struct snd_dma_buffer *dmab);
int snd_dma_buffer_mmap(struct snd_dma_buffer *dmab,
struct vm_area_struct *area);
dma_addr_t snd_sgbuf_get_addr(struct snd_dma_buffer *dmab, size_t offset);
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 */