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authorMuli Ben-Yehuda <mulix@mulix.org>2006-01-11 22:44:42 +0100
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-11 19:04:55 -0800
commit17a941d854a3f7b0bb916fdeee4c9ffdcc19d8d3 (patch)
treeb6b3b55318336adf769bf57141a01a9defbbb202 /arch/x86_64/kernel/pci-swiotlb.c
parent8a6fdd3e912e0ce6f723431d66baf704bf8a1d26 (diff)
[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 <mulix@mulix.org> Signed-Off-By: Jon D. Mason <jdmason@us.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/x86_64/kernel/pci-swiotlb.c')
-rw-r--r--arch/x86_64/kernel/pci-swiotlb.c42
1 files changed, 42 insertions, 0 deletions
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 <linux/pci.h>
+#include <linux/cache.h>
+#include <linux/module.h>
+#include <asm/dma-mapping.h>
+#include <asm/proto.h>
+#include <asm/swiotlb.h>
+#include <asm/dma.h>
+
+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;
+ }
+}