root/include/linux/dma-mapping.h

INCLUDED FROM

DEFINITIONS

1. valid_dma_direction
2. is_device_dma_capable
3. is_buffer_dma_capable
4. dma_get_mask
5. dma_get_max_seg_size
6. dma_set_max_seg_size
7. dma_get_seg_boundary
8. dma_set_seg_boundary
9. dma_declare_coherent_memory
10. dma_release_declared_memory
11. dma_mark_declared_memory_occupied
12. dmam_declare_coherent_memory
13. dmam_release_declared_memory

#ifndef _LINUX_DMA_MAPPING_H
#define _LINUX_DMA_MAPPING_H

#include <linux/device.h>
#include <linux/err.h>

/* These definitions mirror those in pci.h, so they can be used
 * interchangeably with their PCI_ counterparts */
enum dma_data_direction {
        DMA_BIDIRECTIONAL = 0,
        DMA_TO_DEVICE = 1,
        DMA_FROM_DEVICE = 2,
        DMA_NONE = 3,
};

#define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))

/*
 * NOTE: do not use the below macros in new code and do not add new definitions
 * here.
 *
 * Instead, just open-code DMA_BIT_MASK(n) within your driver
 */
#define DMA_64BIT_MASK  DMA_BIT_MASK(64)
#define DMA_48BIT_MASK  DMA_BIT_MASK(48)
#define DMA_47BIT_MASK  DMA_BIT_MASK(47)
#define DMA_40BIT_MASK  DMA_BIT_MASK(40)
#define DMA_39BIT_MASK  DMA_BIT_MASK(39)
#define DMA_35BIT_MASK  DMA_BIT_MASK(35)
#define DMA_32BIT_MASK  DMA_BIT_MASK(32)
#define DMA_31BIT_MASK  DMA_BIT_MASK(31)
#define DMA_30BIT_MASK  DMA_BIT_MASK(30)
#define DMA_29BIT_MASK  DMA_BIT_MASK(29)
#define DMA_28BIT_MASK  DMA_BIT_MASK(28)
#define DMA_24BIT_MASK  DMA_BIT_MASK(24)

#define DMA_MASK_NONE   0x0ULL

static inline int valid_dma_direction(int dma_direction)
{
        return ((dma_direction == DMA_BIDIRECTIONAL) ||
                (dma_direction == DMA_TO_DEVICE) ||
                (dma_direction == DMA_FROM_DEVICE));
}

static inline int is_device_dma_capable(struct device *dev)
{
        return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE;
}

static inline int is_buffer_dma_capable(u64 mask, dma_addr_t addr, size_t size)
{
        return addr + size <= mask;
}

#ifdef CONFIG_HAS_DMA
#include <asm/dma-mapping.h>
#else
#include <asm-generic/dma-mapping-broken.h>
#endif

/* Backwards compat, remove in 2.7.x */
#define dma_sync_single         dma_sync_single_for_cpu
#define dma_sync_sg             dma_sync_sg_for_cpu

static inline u64 dma_get_mask(struct device *dev)
{
        if (dev && dev->dma_mask && *dev->dma_mask)
                return *dev->dma_mask;
        return DMA_32BIT_MASK;
}

extern u64 dma_get_required_mask(struct device *dev);

static inline unsigned int dma_get_max_seg_size(struct device *dev)
{
        return dev->dma_parms ? dev->dma_parms->max_segment_size : 65536;
}

static inline unsigned int dma_set_max_seg_size(struct device *dev,
                                                unsigned int size)
{
        if (dev->dma_parms) {
                dev->dma_parms->max_segment_size = size;
                return 0;
        } else
                return -EIO;
}

static inline unsigned long dma_get_seg_boundary(struct device *dev)
{
        return dev->dma_parms ?
                dev->dma_parms->segment_boundary_mask : 0xffffffff;
}

static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask)
{
        if (dev->dma_parms) {
                dev->dma_parms->segment_boundary_mask = mask;
                return 0;
        } else
                return -EIO;
}

/* flags for the coherent memory api */
#define DMA_MEMORY_MAP                  0x01
#define DMA_MEMORY_IO                   0x02
#define DMA_MEMORY_INCLUDES_CHILDREN    0x04
#define DMA_MEMORY_EXCLUSIVE            0x08

#ifndef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
static inline int
dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
                            dma_addr_t device_addr, size_t size, int flags)
{
        return 0;
}

static inline void
dma_release_declared_memory(struct device *dev)
{
}

static inline void *
dma_mark_declared_memory_occupied(struct device *dev,
                                  dma_addr_t device_addr, size_t size)
{
        return ERR_PTR(-EBUSY);
}
#endif

/*
 * Managed DMA API
 */
extern void *dmam_alloc_coherent(struct device *dev, size_t size,
                                 dma_addr_t *dma_handle, gfp_t gfp);
extern void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
                               dma_addr_t dma_handle);
extern void *dmam_alloc_noncoherent(struct device *dev, size_t size,
                                    dma_addr_t *dma_handle, gfp_t gfp);
extern void dmam_free_noncoherent(struct device *dev, size_t size, void *vaddr,
                                  dma_addr_t dma_handle);
#ifdef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
extern int dmam_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
                                        dma_addr_t device_addr, size_t size,
                                        int flags);
extern void dmam_release_declared_memory(struct device *dev);
#else /* ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY */
static inline int dmam_declare_coherent_memory(struct device *dev,
                                dma_addr_t bus_addr, dma_addr_t device_addr,
                                size_t size, gfp_t gfp)
{
        return 0;
}

static inline void dmam_release_declared_memory(struct device *dev)
{
}
#endif /* ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY */

#ifndef CONFIG_HAVE_DMA_ATTRS
struct dma_attrs;

#define dma_map_single_attrs(dev, cpu_addr, size, dir, attrs) \
        dma_map_single(dev, cpu_addr, size, dir)

#define dma_unmap_single_attrs(dev, dma_addr, size, dir, attrs) \
        dma_unmap_single(dev, dma_addr, size, dir)

#define dma_map_sg_attrs(dev, sgl, nents, dir, attrs) \
        dma_map_sg(dev, sgl, nents, dir)

#define dma_unmap_sg_attrs(dev, sgl, nents, dir, attrs) \
        dma_unmap_sg(dev, sgl, nents, dir)

#endif /* CONFIG_HAVE_DMA_ATTRS */

#endif