[PATCH 05/31] x86/pci-calgary: handle page-less SG entries

Christoph Hellwig hch at lst.de
Wed Aug 12 17:05:24 AEST 2015


For the iommu offset we just need and offset into the page.  Calculate
that using the physical address instead of using the virtual address
so that we don't require a virtual mapping.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 arch/x86/kernel/pci-calgary_64.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index 0497f71..8f1581d 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -368,16 +368,14 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
 {
 	struct iommu_table *tbl = find_iommu_table(dev);
 	struct scatterlist *s;
-	unsigned long vaddr;
+	unsigned long paddr;
 	unsigned int npages;
 	unsigned long entry;
 	int i;
 
 	for_each_sg(sg, s, nelems, i) {
-		BUG_ON(!sg_page(s));
-
-		vaddr = (unsigned long) sg_virt(s);
-		npages = iommu_num_pages(vaddr, s->length, PAGE_SIZE);
+		paddr = sg_phys(s);
+		npages = iommu_num_pages(paddr, s->length, PAGE_SIZE);
 
 		entry = iommu_range_alloc(dev, tbl, npages);
 		if (entry == DMA_ERROR_CODE) {
@@ -389,7 +387,7 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
 		s->dma_address = (entry << PAGE_SHIFT) | s->offset;
 
 		/* insert into HW table */
-		tce_build(tbl, entry, npages, vaddr & PAGE_MASK, dir);
+		tce_build(tbl, entry, npages, paddr & PAGE_MASK, dir);
 
 		s->dma_length = s->length;
 	}
-- 
1.9.1



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