linux-stable/include/asm-x86/dma-mapping_32.h
Jens Axboe 18dabf473e Change table chaining layout
Change the page member of the scatterlist structure to be an unsigned
long, and encode more stuff in the lower bits:

- Bits 0 and 1 zero: this is a normal sg entry. Next sg entry is located
  at sg + 1.
- Bit 0 set: this is a chain entry, the next real entry is at ->page_link
  with the two low bits masked off.
- Bit 1 set: this is the final entry in the sg entry. sg_next() will return
  NULL when passed such an entry.

It's thus important that sg table users use the proper accessors to get
and set the page member.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-22 21:20:01 +02:00

187 lines
4.3 KiB
C

#ifndef _ASM_I386_DMA_MAPPING_H
#define _ASM_I386_DMA_MAPPING_H
#include <linux/mm.h>
#include <linux/scatterlist.h>
#include <asm/cache.h>
#include <asm/io.h>
#include <asm/bug.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)
void *dma_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag);
void dma_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle);
static inline dma_addr_t
dma_map_single(struct device *dev, void *ptr, size_t size,
enum dma_data_direction direction)
{
BUG_ON(!valid_dma_direction(direction));
WARN_ON(size == 0);
flush_write_buffers();
return virt_to_phys(ptr);
}
static inline void
dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
enum dma_data_direction direction)
{
BUG_ON(!valid_dma_direction(direction));
}
static inline int
dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
enum dma_data_direction direction)
{
struct scatterlist *sg;
int i;
BUG_ON(!valid_dma_direction(direction));
WARN_ON(nents == 0 || sglist[0].length == 0);
for_each_sg(sglist, sg, nents, i) {
BUG_ON(!sg_page(sg));
sg->dma_address = sg_phys(sg);
}
flush_write_buffers();
return nents;
}
static inline dma_addr_t
dma_map_page(struct device *dev, struct page *page, unsigned long offset,
size_t size, enum dma_data_direction direction)
{
BUG_ON(!valid_dma_direction(direction));
return page_to_phys(page) + offset;
}
static inline void
dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
enum dma_data_direction direction)
{
BUG_ON(!valid_dma_direction(direction));
}
static inline void
dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
enum dma_data_direction direction)
{
BUG_ON(!valid_dma_direction(direction));
}
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;
}
extern int forbid_dac;
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;
/* Work around chipset bugs */
if (forbid_dac > 0 && mask > 0xffffffffULL)
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)
{
/* no easy way to get cache size on all x86, so return the
* maximum possible, to be safe */
return (1 << INTERNODE_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();
}
#define ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
extern int
dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
dma_addr_t device_addr, size_t size, int flags);
extern void
dma_release_declared_memory(struct device *dev);
extern void *
dma_mark_declared_memory_occupied(struct device *dev,
dma_addr_t device_addr, size_t size);
#endif