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author | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
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committer | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
commit | 849369d6c66d3054688672f97d31fceb8e8230fb (patch) | |
tree | 6135abc790ca67dedbe07c39806591e70eda81ce /arch/powerpc/kernel/dma-iommu.c | |
download | linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.gz linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.bz2 linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.zip |
initial_commit
Diffstat (limited to 'arch/powerpc/kernel/dma-iommu.c')
-rw-r--r-- | arch/powerpc/kernel/dma-iommu.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c new file mode 100644 index 00000000..e7554154 --- /dev/null +++ b/arch/powerpc/kernel/dma-iommu.c @@ -0,0 +1,102 @@ +/* + * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation + * + * Provide default implementations of the DMA mapping callbacks for + * busses using the iommu infrastructure + */ + +#include <asm/iommu.h> + +/* + * Generic iommu implementation + */ + +/* Allocates a contiguous real buffer and creates mappings over it. + * Returns the virtual address of the buffer and sets dma_handle + * to the dma address (mapping) of the first page. + */ +static void *dma_iommu_alloc_coherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t flag) +{ + return iommu_alloc_coherent(dev, get_iommu_table_base(dev), size, + dma_handle, dev->coherent_dma_mask, flag, + dev_to_node(dev)); +} + +static void dma_iommu_free_coherent(struct device *dev, size_t size, + void *vaddr, dma_addr_t dma_handle) +{ + iommu_free_coherent(get_iommu_table_base(dev), size, vaddr, dma_handle); +} + +/* Creates TCEs for a user provided buffer. The user buffer must be + * contiguous real kernel storage (not vmalloc). The address passed here + * comprises a page address and offset into that page. The dma_addr_t + * returned will point to the same byte within the page as was passed in. + */ +static dma_addr_t dma_iommu_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + return iommu_map_page(dev, get_iommu_table_base(dev), page, offset, + size, device_to_mask(dev), direction, attrs); +} + + +static void dma_iommu_unmap_page(struct device *dev, dma_addr_t dma_handle, + size_t size, enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + iommu_unmap_page(get_iommu_table_base(dev), dma_handle, size, direction, + attrs); +} + + +static int dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist, + int nelems, enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + return iommu_map_sg(dev, get_iommu_table_base(dev), sglist, nelems, + device_to_mask(dev), direction, attrs); +} + +static void dma_iommu_unmap_sg(struct device *dev, struct scatterlist *sglist, + int nelems, enum dma_data_direction direction, + struct dma_attrs *attrs) +{ + iommu_unmap_sg(get_iommu_table_base(dev), sglist, nelems, direction, + attrs); +} + +/* We support DMA to/from any memory page via the iommu */ +static int dma_iommu_dma_supported(struct device *dev, u64 mask) +{ + struct iommu_table *tbl = get_iommu_table_base(dev); + + if (!tbl) { + dev_info(dev, "Warning: IOMMU dma not supported: mask 0x%08llx" + ", table unavailable\n", mask); + return 0; + } + + if ((tbl->it_offset + tbl->it_size) > (mask >> IOMMU_PAGE_SHIFT)) { + dev_info(dev, "Warning: IOMMU window too big for device mask\n"); + dev_info(dev, "mask: 0x%08llx, table end: 0x%08lx\n", + mask, (tbl->it_offset + tbl->it_size) << + IOMMU_PAGE_SHIFT); + return 0; + } else + return 1; +} + +struct dma_map_ops dma_iommu_ops = { + .alloc_coherent = dma_iommu_alloc_coherent, + .free_coherent = dma_iommu_free_coherent, + .map_sg = dma_iommu_map_sg, + .unmap_sg = dma_iommu_unmap_sg, + .dma_supported = dma_iommu_dma_supported, + .map_page = dma_iommu_map_page, + .unmap_page = dma_iommu_unmap_page, +}; +EXPORT_SYMBOL(dma_iommu_ops); |