root/include/sound/memalloc.h

INCLUDED FROM

DEFINITIONS

1. snd_sgbuf_aligned_pages
2. snd_sgbuf_get_addr
3. snd_sgbuf_get_ptr

/*
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 *                   Takashi Iwai <tiwai@suse.de>
 * 
 *  Generic memory allocators
 *
 *
 *   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
 *
 */

#ifndef __SOUND_MEMALLOC_H
#define __SOUND_MEMALLOC_H

struct device;

/*
 * buffer device info
 */
struct snd_dma_device {
        int type;                       /* SNDRV_DMA_TYPE_XXX */
        struct device *dev;             /* generic device */
};

#ifndef snd_dma_pci_data
#define snd_dma_pci_data(pci)   (&(pci)->dev)
#define snd_dma_isa_data()      NULL
#define snd_dma_continuous_data(x)      ((struct device *)(unsigned long)(x))
#endif


/*
 * 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_SG           3       /* generic device SG-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 */
};

/*
 * Scatter-Gather generic device pages
 */
void *snd_malloc_sgbuf_pages(struct device *device,
                             size_t size, struct snd_dma_buffer *dmab,
                             size_t *res_size);
int snd_free_sgbuf_pages(struct snd_dma_buffer *dmab);

struct snd_sg_page {
        void *buf;
        dma_addr_t addr;
};

struct snd_sg_buf {
        int size;       /* allocated byte size */
        int pages;      /* allocated pages */
        int tblsize;    /* allocated table size */
        struct snd_sg_page *table;      /* address table */
        struct page **page_table;       /* page table (for vmap/vunmap) */
        struct device *dev;
};

/*
 * 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;
}

/*
 * return the physical address at the corresponding offset
 */
static inline dma_addr_t snd_sgbuf_get_addr(struct snd_sg_buf *sgbuf, size_t offset)
{
        dma_addr_t addr = sgbuf->table[offset >> PAGE_SHIFT].addr;
        addr &= PAGE_MASK;
        return addr + offset % PAGE_SIZE;
}

/*
 * return the virtual address at the corresponding offset
 */
static inline void *snd_sgbuf_get_ptr(struct snd_sg_buf *sgbuf, size_t offset)
{
        return sgbuf->table[offset >> PAGE_SHIFT].buf + offset % PAGE_SIZE;
}

/* 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);

/* buffer-preservation managements */

#define snd_dma_pci_buf_id(pci) (((unsigned int)(pci)->vendor << 16) | (pci)->device)

size_t snd_dma_get_reserved_buf(struct snd_dma_buffer *dmab, unsigned int id);
int snd_dma_reserve_buf(struct snd_dma_buffer *dmab, unsigned int id);

/* basic memory allocation functions */
void *snd_malloc_pages(size_t size, gfp_t gfp_flags);
void snd_free_pages(void *ptr, size_t size);

#endif /* __SOUND_MEMALLOC_H */