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Diffstat (limited to 'kernel/arch/microblaze/kernel/dma.c')
| -rw-r--r-- | kernel/arch/microblaze/kernel/dma.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/kernel/arch/microblaze/kernel/dma.c b/kernel/arch/microblaze/kernel/dma.c new file mode 100644 index 000000000..ed7ba8a11 --- /dev/null +++ b/kernel/arch/microblaze/kernel/dma.c @@ -0,0 +1,207 @@ +/* + * Copyright (C) 2009-2010 PetaLogix + * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation + * + * Provide default implementations of the DMA mapping callbacks for + * directly mapped busses. + */ + +#include <linux/device.h> +#include <linux/dma-mapping.h> +#include <linux/gfp.h> +#include <linux/dma-debug.h> +#include <linux/export.h> +#include <linux/bug.h> + +#define NOT_COHERENT_CACHE + +static void *dma_direct_alloc_coherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t flag, + struct dma_attrs *attrs) +{ +#ifdef NOT_COHERENT_CACHE + return consistent_alloc(flag, size, dma_handle); +#else + void *ret; + struct page *page; + int node = dev_to_node(dev); + + /* ignore region specifiers */ + flag &= ~(__GFP_HIGHMEM); + + page = alloc_pages_node(node, flag, get_order(size)); + if (page == NULL) + return NULL; + ret = page_address(page); + memset(ret, 0, size); + *dma_handle = virt_to_phys(ret); + + return ret; +#endif +} + +static void dma_direct_free_coherent(struct device *dev, size_t size, + void *vaddr, dma_addr_t dma_handle, + struct dma_attrs *attrs) +{ +#ifdef NOT_COHERENT_CACHE + consistent_free(size, vaddr); +#else + free_pages((unsigned long)vaddr, get_order(size)); +#endif +} + +static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, + int nents, enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + struct scatterlist *sg; + int i; + + /* FIXME this part of code is untested */ + for_each_sg(sgl, sg, nents, i) { + sg->dma_address = sg_phys(sg); + __dma_sync(page_to_phys(sg_page(sg)) + sg->offset, + sg->length, direction); + } + + return nents; +} + +static int dma_direct_dma_supported(struct device *dev, u64 mask) +{ + return 1; +} + +static inline dma_addr_t dma_direct_map_page(struct device *dev, + struct page *page, + unsigned long offset, + size_t size, + enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + __dma_sync(page_to_phys(page) + offset, size, direction); + return page_to_phys(page) + offset; +} + +static inline void dma_direct_unmap_page(struct device *dev, + dma_addr_t dma_address, + size_t size, + enum dma_data_direction direction, + struct dma_attrs *attrs) +{ +/* There is not necessary to do cache cleanup + * + * phys_to_virt is here because in __dma_sync_page is __virt_to_phys and + * dma_address is physical address + */ + __dma_sync(dma_address, size, direction); +} + +static inline void +dma_direct_sync_single_for_cpu(struct device *dev, + dma_addr_t dma_handle, size_t size, + enum dma_data_direction direction) +{ + /* + * It's pointless to flush the cache as the memory segment + * is given to the CPU + */ + + if (direction == DMA_FROM_DEVICE) + __dma_sync(dma_handle, size, direction); +} + +static inline void +dma_direct_sync_single_for_device(struct device *dev, + dma_addr_t dma_handle, size_t size, + enum dma_data_direction direction) +{ + /* + * It's pointless to invalidate the cache if the device isn't + * supposed to write to the relevant region + */ + + if (direction == DMA_TO_DEVICE) + __dma_sync(dma_handle, size, direction); +} + +static inline void +dma_direct_sync_sg_for_cpu(struct device *dev, + struct scatterlist *sgl, int nents, + enum dma_data_direction direction) +{ + struct scatterlist *sg; + int i; + + /* FIXME this part of code is untested */ + if (direction == DMA_FROM_DEVICE) + for_each_sg(sgl, sg, nents, i) + __dma_sync(sg->dma_address, sg->length, direction); +} + +static inline void +dma_direct_sync_sg_for_device(struct device *dev, + struct scatterlist *sgl, int nents, + enum dma_data_direction direction) +{ + struct scatterlist *sg; + int i; + + /* FIXME this part of code is untested */ + if (direction == DMA_TO_DEVICE) + for_each_sg(sgl, sg, nents, i) + __dma_sync(sg->dma_address, sg->length, direction); +} + +int dma_direct_mmap_coherent(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t handle, size_t size, + struct dma_attrs *attrs) +{ +#ifdef CONFIG_MMU + unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; + unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; + unsigned long off = vma->vm_pgoff; + unsigned long pfn; + + if (off >= count || user_count > (count - off)) + return -ENXIO; + +#ifdef NOT_COHERENT_CACHE + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + pfn = consistent_virt_to_pfn(cpu_addr); +#else + pfn = virt_to_pfn(cpu_addr); +#endif + return remap_pfn_range(vma, vma->vm_start, pfn + off, + vma->vm_end - vma->vm_start, vma->vm_page_prot); +#else + return -ENXIO; +#endif +} + +struct dma_map_ops dma_direct_ops = { + .alloc = dma_direct_alloc_coherent, + .free = dma_direct_free_coherent, + .mmap = dma_direct_mmap_coherent, + .map_sg = dma_direct_map_sg, + .dma_supported = dma_direct_dma_supported, + .map_page = dma_direct_map_page, + .unmap_page = dma_direct_unmap_page, + .sync_single_for_cpu = dma_direct_sync_single_for_cpu, + .sync_single_for_device = dma_direct_sync_single_for_device, + .sync_sg_for_cpu = dma_direct_sync_sg_for_cpu, + .sync_sg_for_device = dma_direct_sync_sg_for_device, +}; +EXPORT_SYMBOL(dma_direct_ops); + +/* Number of entries preallocated for DMA-API debugging */ +#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16) + +static int __init dma_init(void) +{ + dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); + + return 0; +} +fs_initcall(dma_init); |