From 17a941d854a3f7b0bb916fdeee4c9ffdcc19d8d3 Mon Sep 17 00:00:00 2001 From: Muli Ben-Yehuda Date: Wed, 11 Jan 2006 22:44:42 +0100 Subject: [PATCH] x86_64: Use function pointers to call DMA mapping functions AK: I hacked Muli's original patch a lot and there were a lot of changes - all bugs are probably to blame on me now. There were also some changes in the fall back behaviour for swiotlb - in particular it doesn't try to use GFP_DMA now anymore. Also all DMA mapping operations use the same core dma_alloc_coherent code with proper fallbacks now. And various other changes and cleanups. Known problems: iommu=force swiotlb=force together breaks needs more testing. This patch cleans up x86_64's DMA mapping dispatching code. Right now we have three possible IOMMU types: AGP GART, swiotlb and nommu, and in the future we will also have Xen's x86_64 swiotlb and other HW IOMMUs for x86_64. In order to support all of them cleanly, this patch: - introduces a struct dma_mapping_ops with function pointers for each of the DMA mapping operations of gart (AMD HW IOMMU), swiotlb (software IOMMU) and nommu (no IOMMU). - gets rid of: if (swiotlb) return swiotlb_xxx(); - PCI_DMA_BUS_IS_PHYS is now checked against the dma_ops being set This makes swiotlb faster by avoiding double copying in some cases. Signed-Off-By: Muli Ben-Yehuda Signed-Off-By: Jon D. Mason Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/pci-swiotlb.c | 42 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 arch/x86_64/kernel/pci-swiotlb.c (limited to 'arch/x86_64/kernel/pci-swiotlb.c') diff --git a/arch/x86_64/kernel/pci-swiotlb.c b/arch/x86_64/kernel/pci-swiotlb.c new file mode 100644 index 00000000000..3569a25ad7f --- /dev/null +++ b/arch/x86_64/kernel/pci-swiotlb.c @@ -0,0 +1,42 @@ +/* Glue code to lib/swiotlb.c */ + +#include +#include +#include +#include +#include +#include +#include + +int swiotlb __read_mostly; +EXPORT_SYMBOL(swiotlb); + +struct dma_mapping_ops swiotlb_dma_ops = { + .mapping_error = swiotlb_dma_mapping_error, + .alloc_coherent = swiotlb_alloc_coherent, + .free_coherent = swiotlb_free_coherent, + .map_single = swiotlb_map_single, + .unmap_single = swiotlb_unmap_single, + .sync_single_for_cpu = swiotlb_sync_single_for_cpu, + .sync_single_for_device = swiotlb_sync_single_for_device, + .sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu, + .sync_single_range_for_device = swiotlb_sync_single_range_for_device, + .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu, + .sync_sg_for_device = swiotlb_sync_sg_for_device, + .map_sg = swiotlb_map_sg, + .unmap_sg = swiotlb_unmap_sg, + .dma_supported = NULL, +}; + +void pci_swiotlb_init(void) +{ + /* don't initialize swiotlb if iommu=off (no_iommu=1) */ + if (!iommu_aperture && !no_iommu && + (end_pfn > MAX_DMA32_PFN || force_iommu)) + swiotlb = 1; + if (swiotlb) { + swiotlb_init(); + printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n"); + dma_ops = &swiotlb_dma_ops; + } +} -- cgit v1.2.3