4c374af5fd
Checking for device mask to cover the whole IOMMU table is too strict. IOMMU allocators should handle mask constraint properly for each allocation. The patch enables to use old AirPort Extreme cards on PowerMacs with more than 1GB of memory; without the patch the driver init fails with: b43-pci-bridge 0001:01:01.0: Warning: IOMMU window too big for device mask b43-pci-bridge 0001:01:01.0: mask: 0x3fffffff, table end: 0x80000000 b43-phy0 ERROR: The machine/kernel does not support the required 30-bit DMA mask Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
120 lines
3.5 KiB
C
120 lines
3.5 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 <linux/export.h>
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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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struct dma_attrs *attrs)
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{
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return iommu_alloc_coherent(dev, get_iommu_table_base(dev), size,
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dma_handle, dev->coherent_dma_mask, 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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struct dma_attrs *attrs)
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{
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iommu_free_coherent(get_iommu_table_base(dev), 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, get_iommu_table_base(dev), page, offset,
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size, 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(get_iommu_table_base(dev), 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, get_iommu_table_base(dev), 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(get_iommu_table_base(dev), 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 = get_iommu_table_base(dev);
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if (!tbl) {
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dev_info(dev, "Warning: IOMMU dma not supported: mask 0x%08llx"
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", table unavailable\n", mask);
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return 0;
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}
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if (tbl->it_offset > (mask >> IOMMU_PAGE_SHIFT)) {
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dev_info(dev, "Warning: IOMMU offset too big for device mask\n");
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dev_info(dev, "mask: 0x%08llx, table offset: 0x%08lx\n",
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mask, tbl->it_offset << IOMMU_PAGE_SHIFT);
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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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static u64 dma_iommu_get_required_mask(struct device *dev)
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{
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struct iommu_table *tbl = get_iommu_table_base(dev);
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u64 mask;
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if (!tbl)
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return 0;
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mask = 1ULL < (fls_long(tbl->it_offset + tbl->it_size) - 1);
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mask += mask - 1;
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return mask;
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}
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struct dma_map_ops dma_iommu_ops = {
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.alloc = dma_iommu_alloc_coherent,
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.free = dma_iommu_free_coherent,
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.mmap = dma_direct_mmap_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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.get_required_mask = dma_iommu_get_required_mask,
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};
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EXPORT_SYMBOL(dma_iommu_ops);
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