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Diffstat (limited to 'include/asm-avr32/dma-mapping.h')
| -rw-r--r-- | include/asm-avr32/dma-mapping.h | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/include/asm-avr32/dma-mapping.h b/include/asm-avr32/dma-mapping.h new file mode 100644 index 000000000000..4c40cb41cdf8 --- /dev/null +++ b/include/asm-avr32/dma-mapping.h @@ -0,0 +1,320 @@ +#ifndef __ASM_AVR32_DMA_MAPPING_H +#define __ASM_AVR32_DMA_MAPPING_H + +#include <linux/mm.h> +#include <linux/device.h> +#include <asm/scatterlist.h> +#include <asm/processor.h> +#include <asm/cacheflush.h> +#include <asm/io.h> + +extern void dma_cache_sync(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_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(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[i].page) + sg[i].offset; + virt = page_address(sg[i].page) + sg[i].offset; + dma_cache_sync(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) +{ + dma_cache_sync(bus_to_virt(dma_handle), size, 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) +{ + dma_cache_sync(bus_to_virt(dma_handle), 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) +{ + int i; + + for (i = 0; i < nents; i++) { + dma_cache_sync(page_address(sg[i].page) + sg[i].offset, + sg[i].length, direction); + } +} + +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(page_address(sg[i].page) + sg[i].offset, + 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) + +static inline int dma_is_consistent(dma_addr_t dma_addr) +{ + return 1; +} + +static inline int dma_get_cache_alignment(void) +{ + return boot_cpu_data.dcache.linesz; +} + +#endif /* __ASM_AVR32_DMA_MAPPING_H */ |