dma-mapping.h
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#ifndef _ASM_DMA_MAPPING_H
#define _ASM_DMA_MAPPING_H
#include <linux/device.h>
#include <asm/cache.h>
#include <asm/cacheflush.h>
#include <asm/scatterlist.h>
#include <asm/io.h>
#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
#define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
extern unsigned long __nongprelbss dma_coherent_mem_start;
extern unsigned long __nongprelbss dma_coherent_mem_end;
void *dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp);
void dma_free_coherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle);
/*
* These macros should be used after a pci_map_sg call has been done
* to get bus addresses of each of the SG entries and their lengths.
* You should only work with the number of sg entries pci_map_sg
* returns, or alternatively stop on the first sg_dma_len(sg) which
* is 0.
*/
#define sg_dma_address(sg) ((sg)->dma_address)
#define sg_dma_len(sg) ((sg)->length)
/*
* Map a single buffer of the indicated size for DMA in streaming mode.
* The 32-bit bus address to use is returned.
*
* Once the device is given the dma address, the device owns this memory
* until either pci_unmap_single or pci_dma_sync_single is performed.
*/
extern dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
enum dma_data_direction direction);
/*
* Unmap a single streaming mode DMA translation. The dma_addr and size
* must match what was provided for in a previous pci_map_single call. All
* other usages are undefined.
*
* After this call, reads by the cpu to the buffer are guarenteed to see
* whatever the device wrote there.
*/
static inline
void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
enum dma_data_direction direction)
{
BUG_ON(direction == DMA_NONE);
}
/*
* Map a set of buffers described by scatterlist in streaming
* mode for DMA. This is the scather-gather version of the
* above pci_map_single interface. Here the scatter gather list
* elements are each tagged with the appropriate dma address
* and length. They are obtained via sg_dma_{address,length}(SG).
*
* NOTE: An implementation may be able to use a smaller number of
* DMA address/length pairs than there are SG table elements.
* (for example via virtual mapping capabilities)
* The routine returns the number of addr/length pairs actually
* used, at most nents.
*
* Device ownership issues as mentioned above for pci_map_single are
* the same here.
*/
extern int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction direction);
/*
* Unmap a set of streaming mode DMA translations.
* Again, cpu read rules concerning calls here are the same as for
* pci_unmap_single() above.
*/
static inline
void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
enum dma_data_direction direction)
{
BUG_ON(direction == DMA_NONE);
}
extern
dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset,
size_t size, enum dma_data_direction direction);
static inline
void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
enum dma_data_direction direction)
{
BUG_ON(direction == DMA_NONE);
}
static inline
void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size,
enum dma_data_direction direction)
{
}
static inline
void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size,
enum dma_data_direction direction)
{
flush_write_buffers();
}
static inline
void dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
unsigned long offset, size_t size,
enum dma_data_direction direction)
{
}
static inline
void dma_sync_single_range_for_device(struct device *dev, dma_addr_t dma_handle,
unsigned long offset, size_t size,
enum dma_data_direction direction)
{
flush_write_buffers();
}
static inline
void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
enum dma_data_direction direction)
{
}
static inline
void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems,
enum dma_data_direction direction)
{
flush_write_buffers();
}
static inline
int dma_mapping_error(dma_addr_t dma_addr)
{
return 0;
}
static inline
int dma_supported(struct device *dev, u64 mask)
{
/*
* we fall back to GFP_DMA when the mask isn't all 1s,
* so we can't guarantee allocations that must be
* within a tighter range than GFP_DMA..
*/
if (mask < 0x00ffffff)
return 0;
return 1;
}
static inline
int dma_set_mask(struct device *dev, u64 mask)
{
if (!dev->dma_mask || !dma_supported(dev, mask))
return -EIO;
*dev->dma_mask = mask;
return 0;
}
static inline
int dma_get_cache_alignment(void)
{
return 1 << L1_CACHE_SHIFT;
}
#define dma_is_consistent(d, h) (1)
static inline
void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
enum dma_data_direction direction)
{
flush_write_buffers();
}
#endif /* _ASM_DMA_MAPPING_H */