diff options
Diffstat (limited to 'arch/arm/include/asm/dma-mapping.h')
| -rw-r--r-- | arch/arm/include/asm/dma-mapping.h | 474 |
1 files changed, 474 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 00000000..cb3b7c98 --- /dev/null +++ b/arch/arm/include/asm/dma-mapping.h @@ -0,0 +1,474 @@ +#ifndef ASMARM_DMA_MAPPING_H +#define ASMARM_DMA_MAPPING_H + +#ifdef __KERNEL__ + +#include <linux/mm_types.h> +#include <linux/scatterlist.h> +#include <linux/dma-debug.h> + +#include <asm-generic/dma-coherent.h> +#include <asm/memory.h> + +#ifdef __arch_page_to_dma +#error Please update to __arch_pfn_to_dma +#endif + +/* + * dma_to_pfn/pfn_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_pfn_to_dma +static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn) +{ + return (dma_addr_t)__pfn_to_bus(pfn); +} + +static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr) +{ + return __bus_to_pfn(addr); +} + +static inline void *dma_to_virt(struct device *dev, dma_addr_t addr) +{ + return (void *)__bus_to_virt((unsigned long)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 pfn_to_dma(struct device *dev, unsigned long pfn) +{ + return __arch_pfn_to_dma(dev, pfn); +} + +static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr) +{ + return __arch_dma_to_pfn(dev, addr); +} + +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 + +/* + * The DMA API is built upon the notion of "buffer ownership". A buffer + * is either exclusively owned by the CPU (and therefore may be accessed + * by it) or exclusively owned by the DMA device. These helper functions + * represent the transitions between these two ownership states. + * + * Note, however, that on later ARMs, this notion does not work due to + * speculative prefetches. We model our approach on the assumption that + * the CPU does do speculative prefetches, which means we clean caches + * before transfers and delay cache invalidation until transfer completion. + * + * Private support functions: these are not part of the API and are + * liable to change. Drivers must not use these. + */ +static inline void __dma_single_cpu_to_dev(const void *kaddr, size_t size, + enum dma_data_direction dir) +{ + extern void ___dma_single_cpu_to_dev(const void *, size_t, + enum dma_data_direction); + + if (!arch_is_coherent()) + ___dma_single_cpu_to_dev(kaddr, size, dir); +} + +static inline void __dma_single_dev_to_cpu(const void *kaddr, size_t size, + enum dma_data_direction dir) +{ + extern void ___dma_single_dev_to_cpu(const void *, size_t, + enum dma_data_direction); + + if (!arch_is_coherent()) + ___dma_single_dev_to_cpu(kaddr, size, dir); +} + +static inline void __dma_page_cpu_to_dev(struct page *page, unsigned long off, + size_t size, enum dma_data_direction dir) +{ + extern void ___dma_page_cpu_to_dev(struct page *, unsigned long, + size_t, enum dma_data_direction); + + if (!arch_is_coherent()) + ___dma_page_cpu_to_dev(page, off, size, dir); +} + +static inline void __dma_page_dev_to_cpu(struct page *page, unsigned long off, + size_t size, enum dma_data_direction dir) +{ + extern void ___dma_page_dev_to_cpu(struct page *, unsigned long, + size_t, enum dma_data_direction); + + if (!arch_is_coherent()) + ___dma_page_dev_to_cpu(page, off, size, dir); +} + +extern int dma_supported(struct device *, u64); +extern int dma_set_mask(struct device *, u64); + +/* + * 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 *, size_t, dma_addr_t *, gfp_t); + +/** + * 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 *, size_t, void *, dma_addr_t); + +/** + * 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 *, struct vm_area_struct *, + void *, dma_addr_t, size_t); + + +/** + * 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 *, size_t, dma_addr_t *, + gfp_t); + +#define dma_free_writecombine(dev,size,cpu_addr,handle) \ + dma_free_coherent(dev,size,cpu_addr,handle) + +int dma_mmap_writecombine(struct device *, struct vm_area_struct *, + void *, dma_addr_t, size_t); + +/* + * This can be called during boot to increase the size of the consistent + * DMA region above it's default value of 2MB. It must be called before the + * memory allocator is initialised, i.e. before any core_initcall. + */ +extern void __init init_consistent_dma_size(unsigned long size); + + +#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) + * @needs_bounce_fn: called to determine whether buffer needs bouncing + * + * 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, int (*)(struct device *, dma_addr_t, size_t)); + +/** + * 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 *); + +/* + * The DMA API, implemented by dmabounce.c. See below for descriptions. + */ +extern dma_addr_t __dma_map_page(struct device *, struct page *, + unsigned long, size_t, enum dma_data_direction); +extern void __dma_unmap_page(struct device *, dma_addr_t, size_t, + enum dma_data_direction); + +/* + * Private functions + */ +int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long, + size_t, enum dma_data_direction); +int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long, + size_t, enum dma_data_direction); +#else +static inline int dmabounce_sync_for_cpu(struct device *d, dma_addr_t addr, + unsigned long offset, size_t size, enum dma_data_direction dir) +{ + return 1; +} + +static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr, + unsigned long offset, size_t size, enum dma_data_direction dir) +{ + return 1; +} + + +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) +{ + __dma_page_cpu_to_dev(page, offset, size, dir); + return pfn_to_dma(dev, page_to_pfn(page)) + offset; +} + +static inline void __dma_unmap_page(struct device *dev, dma_addr_t handle, + size_t size, enum dma_data_direction dir) +{ + __dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)), + handle & ~PAGE_MASK, size, dir); +} +#endif /* CONFIG_DMABOUNCE */ + +/** + * 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(). + */ +static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr, + size_t size, enum dma_data_direction dir) +{ + unsigned long offset; + struct page *page; + dma_addr_t addr; + + BUG_ON(!virt_addr_valid(cpu_addr)); + BUG_ON(!virt_addr_valid(cpu_addr + size - 1)); + BUG_ON(!valid_dma_direction(dir)); + + page = virt_to_page(cpu_addr); + offset = (unsigned long)cpu_addr & ~PAGE_MASK; + addr = __dma_map_page(dev, page, offset, size, dir); + debug_dma_map_page(dev, page, offset, size, dir, addr, true); + + return addr; +} + +/** + * 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(). + */ +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) +{ + dma_addr_t addr; + + BUG_ON(!valid_dma_direction(dir)); + + addr = __dma_map_page(dev, page, offset, size, dir); + debug_dma_map_page(dev, page, offset, size, dir, addr, false); + + return 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 (same as passed to dma_map_single) + * @dir: DMA transfer direction (same as passed to dma_map_single) + * + * 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 handle, + size_t size, enum dma_data_direction dir) +{ + debug_dma_unmap_page(dev, handle, size, dir, true); + __dma_unmap_page(dev, handle, size, dir); +} + +/** + * 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 (same as passed to dma_map_page) + * @dir: DMA transfer direction (same as passed to dma_map_page) + * + * Unmap a page streaming mode DMA translation. The handle and size + * must match what was provided in the previous dma_map_page() 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) +{ + debug_dma_unmap_page(dev, handle, size, dir, false); + __dma_unmap_page(dev, handle, size, dir); +} + +/** + * 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. + */ +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) +{ + BUG_ON(!valid_dma_direction(dir)); + + debug_dma_sync_single_for_cpu(dev, handle + offset, size, dir); + + if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir)) + return; + + __dma_single_dev_to_cpu(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) +{ + BUG_ON(!valid_dma_direction(dir)); + + debug_dma_sync_single_for_device(dev, handle + offset, size, dir); + + if (!dmabounce_sync_for_device(dev, handle, offset, size, dir)) + return; + + __dma_single_cpu_to_dev(dma_to_virt(dev, handle) + offset, size, dir); +} + +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); +} + +/* + * The scatter list versions of the above methods. + */ +extern int dma_map_sg(struct device *, struct scatterlist *, int, + enum dma_data_direction); +extern void dma_unmap_sg(struct device *, struct scatterlist *, int, + enum dma_data_direction); +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 /* __KERNEL__ */ +#endif |