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After the merge of the 32 and 64bit DMA code, dma_direct_ops lost their map/unmap_single() functions but gained map/unmap_page(). This caused a problem for Cell because Cell's dma_iommu_fixed_ops called the dma_direct_ops if the fixed linear mapping was to be used or the iommu ops if the dynamic window was to be used. So in order to fix this problem we need to update the 64bit DMA code to use map/unmap_page. First, we update the generic IOMMU code so that iommu_map_single() becomes iommu_map_page() and iommu_unmap_single() becomes iommu_unmap_page(). Then we propagate these changes up through all the callers of these two functions and in the process update all the dma_mapping_ops so that they have map/unmap_page rahter than map/unmap_single. We can do this because on 64bit there is no HIGHMEM memory so map/unmap_page ends up performing exactly the same function as map/unmap_single, just taking different arguments. This has no affect on drivers because the dma_map_single_attrs() just ends up calling the map_page() function of the appropriate dma_mapping_ops and similarly the dma_unmap_single_attrs() calls unmap_page(). This fixes an oops on Cell blades, which oops on boot without this because they call dma_direct_ops.map_single, which is NULL. Signed-off-by: Mark Nelson <markn@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
102 lines
3.1 KiB
C
102 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 passed here
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* comprises a page address and offset into that page. The dma_addr_t
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* returned will point to the same byte within the page as was passed in.
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*/
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static dma_addr_t dma_iommu_map_page(struct device *dev, struct page *page,
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unsigned long offset, 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_page(dev, dev->archdata.dma_data, page, offset, size,
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device_to_mask(dev), direction, attrs);
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}
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static void dma_iommu_unmap_page(struct device *dev, dma_addr_t dma_handle,
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size_t size, enum dma_data_direction direction,
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struct dma_attrs *attrs)
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{
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iommu_unmap_page(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_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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.map_page = dma_iommu_map_page,
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.unmap_page = dma_iommu_unmap_page,
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};
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EXPORT_SYMBOL(dma_iommu_ops);
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