From: Nadav Amit Date: Fri, 23 Jul 2021 09:32:08 +0000 (-0700) Subject: iommu/amd: Sync once for scatter-gather operations X-Git-Tag: accepted/tizen/unified/20230118.172025~6400^2~5^5~3 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3b122a5666cb7c0bb9a439fba0c9a6cf59f999c3;p=platform%2Fkernel%2Flinux-rpi.git iommu/amd: Sync once for scatter-gather operations On virtual machines, software must flush the IOTLB after each page table entry update. The iommu_map_sg() code iterates through the given scatter-gather list and invokes iommu_map() for each element in the scatter-gather list, which calls into the vendor IOMMU driver through iommu_ops callback. As the result, a single sg mapping may lead to multiple IOTLB flushes. Fix this by adding amd_iotlb_sync_map() callback and flushing at this point after all sg mappings we set. This commit is followed and inspired by commit 933fcd01e97e2 ("iommu/vt-d: Add iotlb_sync_map callback"). Cc: Joerg Roedel Cc: Will Deacon Cc: Jiajun Cao Cc: Robin Murphy Cc: Lu Baolu Cc: iommu@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Nadav Amit Link: https://lore.kernel.org/r/20210723093209.714328-7-namit@vmware.com Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 0957be3..cee91cd 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -2028,6 +2028,16 @@ static int amd_iommu_attach_device(struct iommu_domain *dom, return ret; } +static void amd_iommu_iotlb_sync_map(struct iommu_domain *dom, + unsigned long iova, size_t size) +{ + struct protection_domain *domain = to_pdomain(dom); + struct io_pgtable_ops *ops = &domain->iop.iop.ops; + + if (ops->map) + domain_flush_np_cache(domain, iova, size); +} + static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova, phys_addr_t paddr, size_t page_size, int iommu_prot, gfp_t gfp) @@ -2046,10 +2056,8 @@ static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova, if (iommu_prot & IOMMU_WRITE) prot |= IOMMU_PROT_IW; - if (ops->map) { + if (ops->map) ret = ops->map(ops, iova, paddr, page_size, prot, gfp); - domain_flush_np_cache(domain, iova, page_size); - } return ret; } @@ -2229,6 +2237,7 @@ const struct iommu_ops amd_iommu_ops = { .attach_dev = amd_iommu_attach_device, .detach_dev = amd_iommu_detach_device, .map = amd_iommu_map, + .iotlb_sync_map = amd_iommu_iotlb_sync_map, .unmap = amd_iommu_unmap, .iova_to_phys = amd_iommu_iova_to_phys, .probe_device = amd_iommu_probe_device,