mirror of https://gitee.com/openkylin/linux.git
104 lines
3.1 KiB
C
104 lines
3.1 KiB
C
/*
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* Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
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*
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* Provide default implementations of the DMA mapping callbacks for
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* busses using the iommu infrastructure
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*/
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#include <asm/iommu.h>
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/*
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* Generic iommu implementation
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*/
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/* Allocates a contiguous real buffer and creates mappings over it.
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* Returns the virtual address of the buffer and sets dma_handle
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* to the dma address (mapping) of the first page.
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*/
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static void *dma_iommu_alloc_coherent(struct device *dev, size_t size,
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dma_addr_t *dma_handle, gfp_t flag)
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{
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return iommu_alloc_coherent(dev, dev->archdata.dma_data, size,
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dma_handle, device_to_mask(dev), flag,
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dev_to_node(dev));
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}
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static void dma_iommu_free_coherent(struct device *dev, size_t size,
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void *vaddr, dma_addr_t dma_handle)
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{
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iommu_free_coherent(dev->archdata.dma_data, size, vaddr, dma_handle);
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}
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/* Creates TCEs for a user provided buffer. The user buffer must be
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* contiguous real kernel storage (not vmalloc). The address of the buffer
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* passed here is the kernel (virtual) address of the buffer. The buffer
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* need not be page aligned, the dma_addr_t returned will point to the same
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* byte within the page as vaddr.
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*/
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static dma_addr_t dma_iommu_map_single(struct device *dev, void *vaddr,
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size_t size,
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enum dma_data_direction direction,
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struct dma_attrs *attrs)
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{
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return iommu_map_single(dev, dev->archdata.dma_data, vaddr, size,
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device_to_mask(dev), direction, attrs);
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}
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static void dma_iommu_unmap_single(struct device *dev, dma_addr_t dma_handle,
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size_t size,
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enum dma_data_direction direction,
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struct dma_attrs *attrs)
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{
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iommu_unmap_single(dev->archdata.dma_data, dma_handle, size, direction,
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attrs);
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}
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static int dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist,
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int nelems, enum dma_data_direction direction,
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struct dma_attrs *attrs)
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{
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return iommu_map_sg(dev, dev->archdata.dma_data, sglist, nelems,
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device_to_mask(dev), direction, attrs);
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}
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static void dma_iommu_unmap_sg(struct device *dev, struct scatterlist *sglist,
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int nelems, enum dma_data_direction direction,
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struct dma_attrs *attrs)
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{
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iommu_unmap_sg(dev->archdata.dma_data, sglist, nelems, direction,
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attrs);
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}
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/* We support DMA to/from any memory page via the iommu */
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static int dma_iommu_dma_supported(struct device *dev, u64 mask)
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{
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struct iommu_table *tbl = dev->archdata.dma_data;
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if (!tbl || tbl->it_offset > mask) {
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printk(KERN_INFO
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"Warning: IOMMU offset too big for device mask\n");
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if (tbl)
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printk(KERN_INFO
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"mask: 0x%08lx, table offset: 0x%08lx\n",
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mask, tbl->it_offset);
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else
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printk(KERN_INFO "mask: 0x%08lx, table unavailable\n",
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mask);
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return 0;
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} else
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return 1;
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}
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struct dma_mapping_ops dma_iommu_ops = {
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.alloc_coherent = dma_iommu_alloc_coherent,
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.free_coherent = dma_iommu_free_coherent,
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.map_single = dma_iommu_map_single,
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.unmap_single = dma_iommu_unmap_single,
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.map_sg = dma_iommu_map_sg,
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.unmap_sg = dma_iommu_unmap_sg,
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.dma_supported = dma_iommu_dma_supported,
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};
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EXPORT_SYMBOL(dma_iommu_ops);
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