- 根目录:
- arch
- avr32
- include
- asm
- dma-mapping.h
#ifndef __ASM_AVR32_DMA_MAPPING_H
#define __ASM_AVR32_DMA_MAPPING_H
#include <linux/mm.h>
#include <linux/device.h>
#include <linux/scatterlist.h>
#include <asm/processor.h>
#include <asm/cacheflush.h>
#include <asm/io.h>
extern void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
int direction);
/*
* Return whether the given device DMA address mask can be supported
* properly. For example, if your device can only drive the low 24-bits
* during bus mastering, then you would pass 0x00ffffff as the mask
* to this function.
*/
static inline int dma_supported(struct device *dev, u64 mask)
{
/* Fix when needed. I really don't know of any limitations */
return 1;
}
static inline int dma_set_mask(struct device *dev, u64 dma_mask)
{
if (!dev->dma_mask || !dma_supported(dev, dma_mask))
return -EIO;
*dev->dma_mask = dma_mask;
return 0;
}
/*
* dma_map_single can't fail as it is implemented now.
*/
static inline int dma_mapping_error(struct device *dev, dma_addr_t addr)
{
return 0;
}
/**
* dma_alloc_coherent - allocate consistent memory for DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @size: required memory size
* @handle: bus-specific DMA address
*
* Allocate some uncached, unbuffered memory for a device for
* performing DMA. This function allocates pages, and will
* return the CPU-viewed address, and sets @handle to be the
* device-viewed address.
*/
extern void *dma_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t gfp);
/**
* dma_free_coherent - free memory allocated by dma_alloc_coherent
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @size: size of memory originally requested in dma_alloc_coherent
* @cpu_addr: CPU-view address returned from dma_alloc_coherent
* @handle: device-view address returned from dma_alloc_coherent
*
* Free (and unmap) a DMA buffer previously allocated by
* dma_alloc_coherent().
*
* References to memory and mappings associated with cpu_addr/handle
* during and after this call executing are illegal.
*/
extern void dma_free_coherent(struct device *dev, size_t size,
void *cpu_addr, dma_addr_t handle);
/**
* dma_alloc_writecombine - allocate write-combining memory for DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @size: required memory size
* @handle: bus-specific DMA address
*
* Allocate some uncached, buffered memory for a device for
* performing DMA. This function allocates pages, and will
* return the CPU-viewed address, and sets @handle to be the
* device-viewed address.
*/
extern void *dma_alloc_writecombine(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t gfp);
/**
* dma_free_coherent - free memory allocated by dma_alloc_writecombine
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @size: size of memory originally requested in dma_alloc_writecombine
* @cpu_addr: CPU-view address returned from dma_alloc_writecombine
* @handle: device-view address returned from dma_alloc_writecombine
*
* Free (and unmap) a DMA buffer previously allocated by
* dma_alloc_writecombine().
*
* References to memory and mappings associated with cpu_addr/handle
* during and after this call executing are illegal.
*/
extern void dma_free_writecombine(struct device *dev, size_t size,
void *cpu_addr, dma_addr_t handle);
/**
* dma_map_single - map a single buffer for streaming DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @cpu_addr: CPU direct mapped address of buffer
* @size: size of buffer to map
* @dir: DMA transfer direction
*
* Ensure that any data held in the cache is appropriately discarded
* or written back.
*
* The device owns this memory once this call has completed. The CPU
* can regain ownership by calling dma_unmap_single() or dma_sync_single().
*/
static inline dma_addr_t
dma_map_single(struct device *dev, void *cpu_addr, size_t size,
enum dma_data_direction direction)
{
dma_cache_sync(dev, cpu_addr, size, direction);
return virt_to_bus(cpu_addr);
}
/**
* dma_unmap_single - unmap a single buffer previously mapped
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @handle: DMA address of buffer
* @size: size of buffer to map
* @dir: DMA transfer direction
*
* Unmap a single streaming mode DMA translation. The handle and size
* must match what was provided in the previous dma_map_single() call.
* All other usages are undefined.
*
* After this call, reads by the CPU to the buffer are guaranteed 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)
{
}
/**
* dma_map_page - map a portion of a page for streaming DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @page: page that buffer resides in
* @offset: offset into page for start of buffer
* @size: size of buffer to map
* @dir: DMA transfer direction
*
* Ensure that any data held in the cache is appropriately discarded
* or written back.
*
* The device owns this memory once this call has completed. The CPU
* can regain ownership by calling dma_unmap_page() or dma_sync_single().
*/
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)
{
return dma_map_single(dev, page_address(page) + offset,
size, direction);
}
/**
* dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @handle: DMA address of buffer
* @size: size of buffer to map
* @dir: DMA transfer direction
*
* Unmap a single streaming mode DMA translation. The handle and size
* must match what was provided in the previous dma_map_single() call.
* All other usages are undefined.
*
* After this call, reads by the CPU to the buffer are guaranteed to see
* whatever the device wrote there.
*/
static inline void
dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
enum dma_data_direction direction)
{
dma_unmap_single(dev, dma_address, size, direction);
}
/**
* dma_map_sg - map a set of SG buffers for streaming mode DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map
* @dir: DMA transfer direction
*
* Map a set of buffers described by scatterlist in streaming
* mode for DMA. This is the scatter-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.
*/
static inline int
dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction direction)
{
int i;
for (i = 0; i < nents; i++) {
char *virt;
sg[i].dma_address = page_to_bus(sg_page(&sg[i])) + sg[i].offset;
virt = sg_virt(&sg[i]);
dma_cache_sync(dev, virt, sg[i].length, direction);
}
return nents;
}
/**
* dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map
* @dir: DMA transfer 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)
{
}
/**
* dma_sync_single_for_cpu
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @handle: DMA address of buffer
* @size: size of buffer to map
* @dir: DMA transfer direction
*
* Make physical memory consistent for a single streaming mode DMA
* translation after a transfer.
*
* If you perform a dma_map_single() but wish to interrogate the
* buffer using the cpu, yet do not wish to teardown the DMA mapping,
* you must call this function before doing so. At the next point you
* give the DMA address back to the card, you must first perform a
* dma_sync_single_for_device, and then the device again owns the
* buffer.
*/
static inline void
dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction direction)
{
/*
* No need to do anything since the CPU isn't supposed to
* touch this memory after we flushed it at mapping- or
* sync-for-device time.
*/
}
static inline void
dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction direction)
{
dma_cache_sync(dev, bus_to_virt(dma_handle), size, direction);
}
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)
{
/* just sync everything, that's all the pci API can do */
dma_sync_single_for_cpu(dev, dma_handle, offset+size, 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)
{
/* just sync everything, that's all the pci API can do */
dma_sync_single_for_device(dev, dma_handle, offset+size, direction);
}
/**
* dma_sync_sg_for_cpu
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map
* @dir: DMA transfer direction
*
* Make physical memory consistent for a set of streaming
* mode DMA translations after a transfer.
*
* The same as dma_sync_single_for_* but for a scatter-gather list,
* same rules and usage.
*/
static inline void
dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction direction)
{
/*
* No need to do anything since the CPU isn't supposed to
* touch this memory after we flushed it at mapping- or
* sync-for-device time.
*/
}
static inline void
dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction direction)
{
int i;
for (i = 0; i < nents; i++) {
dma_cache_sync(dev, sg_virt(&sg[i]), sg[i].length, direction);
}
}
/* Now for the API extensions over the pci_ one */
#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)
/* drivers/base/dma-mapping.c */
extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size);
extern int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t dma_addr,
size_t size);
#define dma_mmap_coherent(d, v, c, h, s) dma_common_mmap(d, v, c, h, s)
#define dma_get_sgtable(d, t, v, h, s) dma_common_get_sgtable(d, t, v, h, s)
#endif /* __ASM_AVR32_DMA_MAPPING_H */