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Diffstat (limited to 'arch/arm/include/asm/dma-mapping.h')
| -rw-r--r-- | arch/arm/include/asm/dma-mapping.h | 512 |
1 files changed, 512 insertions, 0 deletions
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h new file mode 100644 index 000000000000..7b95d2058395 --- /dev/null +++ b/arch/arm/include/asm/dma-mapping.h @@ -0,0 +1,512 @@ +#ifndef ASMARM_DMA_MAPPING_H +#define ASMARM_DMA_MAPPING_H + +#ifdef __KERNEL__ + +#include <linux/mm_types.h> +#include <linux/scatterlist.h> + +#include <asm-generic/dma-coherent.h> +#include <asm/memory.h> + +/* + * page_to_dma/dma_to_virt/virt_to_dma are architecture private functions + * used internally by the DMA-mapping API to provide DMA addresses. They + * must not be used by drivers. + */ +#ifndef __arch_page_to_dma +static inline dma_addr_t page_to_dma(struct device *dev, struct page *page) +{ + return (dma_addr_t)__virt_to_bus((unsigned long)page_address(page)); +} + +static inline void *dma_to_virt(struct device *dev, dma_addr_t addr) +{ + return (void *)__bus_to_virt(addr); +} + +static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) +{ + return (dma_addr_t)__virt_to_bus((unsigned long)(addr)); +} +#else +static inline dma_addr_t page_to_dma(struct device *dev, struct page *page) +{ + return __arch_page_to_dma(dev, page); +} + +static inline void *dma_to_virt(struct device *dev, dma_addr_t addr) +{ + return __arch_dma_to_virt(dev, addr); +} + +static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) +{ + return __arch_virt_to_dma(dev, addr); +} +#endif + +/* + * DMA-consistent mapping functions. These allocate/free a region of + * uncached, unwrite-buffered mapped memory space for use with DMA + * devices. This is the "generic" version. The PCI specific version + * is in pci.h + * + * Note: Drivers should NOT use this function directly, as it will break + * platforms with CONFIG_DMABOUNCE. + * Use the driver DMA support - see dma-mapping.h (dma_sync_*) + */ +extern void dma_cache_maint(const void *kaddr, size_t size, int rw); + +/* + * 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. + * + * FIXME: This should really be a platform specific issue - we should + * return false if GFP_DMA allocations may not satisfy the supplied 'mask'. + */ +static inline int dma_supported(struct device *dev, u64 mask) +{ + return dev->dma_mask && *dev->dma_mask != 0; +} + +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; +} + +static inline int dma_get_cache_alignment(void) +{ + return 32; +} + +static inline int dma_is_consistent(struct device *dev, dma_addr_t handle) +{ + return !!arch_is_coherent(); +} + +/* + * DMA errors are defined by all-bits-set in the DMA address. + */ +static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr) +{ + return dma_addr == ~0; +} + +/* + * Dummy noncoherent implementation. We don't provide a dma_cache_sync + * function so drivers using this API are highlighted with build warnings. + */ +static inline void * +dma_alloc_noncoherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp) +{ + return NULL; +} + +static inline void +dma_free_noncoherent(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle) +{ +} + +/** + * 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_mmap_coherent - map a coherent DMA allocation into user space + * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices + * @vma: vm_area_struct describing requested user mapping + * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent + * @handle: device-view address returned from dma_alloc_coherent + * @size: size of memory originally requested in dma_alloc_coherent + * + * Map a coherent DMA buffer previously allocated by dma_alloc_coherent + * into user space. The coherent DMA buffer must not be freed by the + * driver until the user space mapping has been released. + */ +int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t handle, size_t size); + + +/** + * dma_alloc_writecombine - allocate writecombining 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); + +#define dma_free_writecombine(dev,size,cpu_addr,handle) \ + dma_free_coherent(dev,size,cpu_addr,handle) + +int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t handle, size_t size); + + +/** + * 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_for_cpu(). + */ +#ifndef CONFIG_DMABOUNCE +static inline dma_addr_t +dma_map_single(struct device *dev, void *cpu_addr, size_t size, + enum dma_data_direction dir) +{ + if (!arch_is_coherent()) + dma_cache_maint(cpu_addr, size, dir); + + return virt_to_dma(dev, cpu_addr); +} +#else +extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction); +#endif + +/** + * 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_for_cpu(). + */ +static inline dma_addr_t +dma_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir) +{ + return dma_map_single(dev, page_address(page) + offset, size, dir); +} + +/** + * 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. + */ +#ifndef CONFIG_DMABOUNCE +static inline void +dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size, + enum dma_data_direction dir) +{ + /* nothing to do */ +} +#else +extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction); +#endif + +/** + * 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 handle, size_t size, + enum dma_data_direction dir) +{ + dma_unmap_single(dev, handle, size, dir); +} + +/** + * 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 dma_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 dma_map_single are + * the same here. + */ +#ifndef CONFIG_DMABOUNCE +static inline int +dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, + enum dma_data_direction dir) +{ + int i; + + for (i = 0; i < nents; i++, sg++) { + char *virt; + + sg->dma_address = page_to_dma(dev, sg_page(sg)) + sg->offset; + virt = sg_virt(sg); + + if (!arch_is_coherent()) + dma_cache_maint(virt, sg->length, dir); + } + + return nents; +} +#else +extern int dma_map_sg(struct device *, struct scatterlist *, int, enum dma_data_direction); +#endif + +/** + * 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 + * dma_unmap_single() above. + */ +#ifndef CONFIG_DMABOUNCE +static inline void +dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, + enum dma_data_direction dir) +{ + + /* nothing to do */ +} +#else +extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_data_direction); +#endif + + +/** + * dma_sync_single_range_for_cpu + * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices + * @handle: DMA address of buffer + * @offset: offset of region to start sync + * @size: size of region to sync + * @dir: DMA transfer direction (same as passed to dma_map_single) + * + * 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 PCI dma + * mapping, you must call this function before doing so. At the + * next point you give the PCI dma address back to the card, you + * must first the perform a dma_sync_for_device, and then the + * device again owns the buffer. + */ +#ifndef CONFIG_DMABOUNCE +static inline void +dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t handle, + unsigned long offset, size_t size, + enum dma_data_direction dir) +{ + if (!arch_is_coherent()) + dma_cache_maint(dma_to_virt(dev, handle) + offset, size, dir); +} + +static inline void +dma_sync_single_range_for_device(struct device *dev, dma_addr_t handle, + unsigned long offset, size_t size, + enum dma_data_direction dir) +{ + if (!arch_is_coherent()) + dma_cache_maint(dma_to_virt(dev, handle) + offset, size, dir); +} +#else +extern void dma_sync_single_range_for_cpu(struct device *, dma_addr_t, unsigned long, size_t, enum dma_data_direction); +extern void dma_sync_single_range_for_device(struct device *, dma_addr_t, unsigned long, size_t, enum dma_data_direction); +#endif + +static inline void +dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size, + enum dma_data_direction dir) +{ + dma_sync_single_range_for_cpu(dev, handle, 0, size, dir); +} + +static inline void +dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size, + enum dma_data_direction dir) +{ + dma_sync_single_range_for_device(dev, handle, 0, size, dir); +} + + +/** + * 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. + */ +#ifndef CONFIG_DMABOUNCE +static inline void +dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents, + enum dma_data_direction dir) +{ + int i; + + for (i = 0; i < nents; i++, sg++) { + char *virt = sg_virt(sg); + if (!arch_is_coherent()) + dma_cache_maint(virt, sg->length, dir); + } +} + +static inline void +dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents, + enum dma_data_direction dir) +{ + int i; + + for (i = 0; i < nents; i++, sg++) { + char *virt = sg_virt(sg); + if (!arch_is_coherent()) + dma_cache_maint(virt, sg->length, dir); + } +} +#else +extern void dma_sync_sg_for_cpu(struct device*, struct scatterlist*, int, enum dma_data_direction); +extern void dma_sync_sg_for_device(struct device*, struct scatterlist*, int, enum dma_data_direction); +#endif + +#ifdef CONFIG_DMABOUNCE +/* + * For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic" + * and utilize bounce buffers as needed to work around limited DMA windows. + * + * On the SA-1111, a bug limits DMA to only certain regions of RAM. + * On the IXP425, the PCI inbound window is 64MB (256MB total RAM) + * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM) + * + * The following are helper functions used by the dmabounce subystem + * + */ + +/** + * dmabounce_register_dev + * + * @dev: valid struct device pointer + * @small_buf_size: size of buffers to use with small buffer pool + * @large_buf_size: size of buffers to use with large buffer pool (can be 0) + * + * This function should be called by low-level platform code to register + * a device as requireing DMA buffer bouncing. The function will allocate + * appropriate DMA pools for the device. + * + */ +extern int dmabounce_register_dev(struct device *, unsigned long, unsigned long); + +/** + * dmabounce_unregister_dev + * + * @dev: valid struct device pointer + * + * This function should be called by low-level platform code when device + * that was previously registered with dmabounce_register_dev is removed + * from the system. + * + */ +extern void dmabounce_unregister_dev(struct device *); + +/** + * dma_needs_bounce + * + * @dev: valid struct device pointer + * @dma_handle: dma_handle of unbounced buffer + * @size: size of region being mapped + * + * Platforms that utilize the dmabounce mechanism must implement + * this function. + * + * The dmabounce routines call this function whenever a dma-mapping + * is requested to determine whether a given buffer needs to be bounced + * or not. The function must return 0 if the buffer is OK for + * DMA access and 1 if the buffer needs to be bounced. + * + */ +extern int dma_needs_bounce(struct device*, dma_addr_t, size_t); +#endif /* CONFIG_DMABOUNCE */ + +#endif /* __KERNEL__ */ +#endif |