intel-iommu sg chaining support

x86_64 defines ARCH_HAS_SG_CHAIN. So if IOMMU implementations don't
support sg chaining, we will get data corruption.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 8f372c8..b3d7031 100644 (file)
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -1963,7 +1963,7 @@ static void intel_free_coherent(struct device *hwdev, size_t size,
 }
 
 #define SG_ENT_VIRT_ADDRESS(sg)        (page_address((sg)->page) + (sg)->offset)
-static void intel_unmap_sg(struct device *hwdev, struct scatterlist *sg,
+static void intel_unmap_sg(struct device *hwdev, struct scatterlist *sglist,
        int nelems, int dir)
 {
        int i;
@@ -1973,16 +1973,17 @@ static void intel_unmap_sg(struct device *hwdev, struct scatterlist *sg,
        struct iova *iova;
        size_t size = 0;
        void *addr;
+       struct scatterlist *sg;
 
        if (pdev->dev.archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO)
                return;
 
        domain = find_domain(pdev);
 
-       iova = find_iova(&domain->iovad, IOVA_PFN(sg[0].dma_address));
+       iova = find_iova(&domain->iovad, IOVA_PFN(sglist[0].dma_address));
        if (!iova)
                return;
-       for (i = 0; i < nelems; i++, sg++) {
+       for_each_sg(sglist, sg, nelems, i) {
                addr = SG_ENT_VIRT_ADDRESS(sg);
                size += aligned_size((u64)addr, sg->length);
        }
@@ -2003,21 +2004,21 @@ static void intel_unmap_sg(struct device *hwdev, struct scatterlist *sg,
 }
 
 static int intel_nontranslate_map_sg(struct device *hddev,
-       struct scatterlist *sg, int nelems, int dir)
+       struct scatterlist *sglist, int nelems, int dir)
 {
        int i;
+       struct scatterlist *sg;
 
-       for (i = 0; i < nelems; i++) {
-               struct scatterlist *s = &sg[i];
-               BUG_ON(!s->page);
-               s->dma_address = virt_to_bus(SG_ENT_VIRT_ADDRESS(s));
-               s->dma_length = s->length;
+       for_each_sg(sglist, sg, nelems, i) {
+               BUG_ON(!sg->page);
+               sg->dma_address = virt_to_bus(SG_ENT_VIRT_ADDRESS(sg));
+               sg->dma_length = sg->length;
        }
        return nelems;
 }
 
-static int intel_map_sg(struct device *hwdev, struct scatterlist *sg,
-       int nelems, int dir)
+static int intel_map_sg(struct device *hwdev, struct scatterlist *sglist,
+                               int nelems, int dir)
 {
        void *addr;
        int i;
@@ -2028,18 +2029,18 @@ static int intel_map_sg(struct device *hwdev, struct scatterlist *sg,
        size_t offset = 0;
        struct iova *iova = NULL;
        int ret;
-       struct scatterlist *orig_sg = sg;
+       struct scatterlist *sg;
        unsigned long start_addr;
 
        BUG_ON(dir == DMA_NONE);
        if (pdev->dev.archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO)
-               return intel_nontranslate_map_sg(hwdev, sg, nelems, dir);
+               return intel_nontranslate_map_sg(hwdev, sglist, nelems, dir);
 
        domain = get_valid_domain_for_dev(pdev);
        if (!domain)
                return 0;
 
-       for (i = 0; i < nelems; i++, sg++) {
+       for_each_sg(sglist, sg, nelems, i) {
                addr = SG_ENT_VIRT_ADDRESS(sg);
                addr = (void *)virt_to_phys(addr);
                size += aligned_size((u64)addr, sg->length);
@@ -2047,7 +2048,7 @@ static int intel_map_sg(struct device *hwdev, struct scatterlist *sg,
 
        iova = __intel_alloc_iova(hwdev, domain, size);
        if (!iova) {
-               orig_sg->dma_length = 0;
+               sglist->dma_length = 0;
                return 0;
        }
 
@@ -2063,8 +2064,7 @@ static int intel_map_sg(struct device *hwdev, struct scatterlist *sg,
 
        start_addr = iova->pfn_lo << PAGE_SHIFT_4K;
        offset = 0;
-       sg = orig_sg;
-       for (i = 0; i < nelems; i++, sg++) {
+       for_each_sg(sglist, sg, nelems, i) {
                addr = SG_ENT_VIRT_ADDRESS(sg);
                addr = (void *)virt_to_phys(addr);
                size = aligned_size((u64)addr, sg->length);