![Andi Kleen](/assets/img/avatar_default.png)
It was broken before. But having it is important as possible hardware bug workaround. And previously there was no way to force swiotlb if there is another IOMMU. Side effect is that iommu=force won't force swiotlb anymore even if there isn't another IOMMU. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
44 lines
1.3 KiB
C
44 lines
1.3 KiB
C
/* Glue code to lib/swiotlb.c */
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#include <linux/pci.h>
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#include <linux/cache.h>
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#include <linux/module.h>
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#include <asm/dma-mapping.h>
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#include <asm/proto.h>
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#include <asm/swiotlb.h>
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#include <asm/dma.h>
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int swiotlb __read_mostly;
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EXPORT_SYMBOL(swiotlb);
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struct dma_mapping_ops swiotlb_dma_ops = {
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.mapping_error = swiotlb_dma_mapping_error,
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.alloc_coherent = swiotlb_alloc_coherent,
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.free_coherent = swiotlb_free_coherent,
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.map_single = swiotlb_map_single,
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.unmap_single = swiotlb_unmap_single,
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.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
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.sync_single_for_device = swiotlb_sync_single_for_device,
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.sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
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.sync_single_range_for_device = swiotlb_sync_single_range_for_device,
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.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
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.sync_sg_for_device = swiotlb_sync_sg_for_device,
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.map_sg = swiotlb_map_sg,
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.unmap_sg = swiotlb_unmap_sg,
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.dma_supported = NULL,
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};
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void pci_swiotlb_init(void)
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{
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/* don't initialize swiotlb if iommu=off (no_iommu=1) */
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if (!iommu_detected && !no_iommu && end_pfn > MAX_DMA32_PFN)
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swiotlb = 1;
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if (swiotlb_force)
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swiotlb = 1;
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if (swiotlb) {
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printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
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swiotlb_init();
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dma_ops = &swiotlb_dma_ops;
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}
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}
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