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authorArvind Sankar <nivedita@alum.mit.edu>2019-10-08 10:33:57 -0400
committerChristoph Hellwig <hch@lst.de>2019-10-18 17:19:20 +0200
commit9c24eaf81cc44d4bb38081c99eafd72ed85cf7f3 (patch)
treec7308459daee66e24068e6b1bd9e685553e36dd9 /drivers
parent0e2adab6cf285c41e825b6c74a3aa61324d1132c (diff)
iommu/vt-d: Return the correct dma mask when we are bypassing the IOMMU
We must return a mask covering the full physical RAM when bypassing the IOMMU mapping. Also, in iommu_need_mapping, we need to check using dma_direct_get_required_mask to ensure that the device's dma_mask can cover physical RAM before deciding to bypass IOMMU mapping. Based on an earlier patch from Christoph Hellwig. Fixes: 249baa547901 ("dma-mapping: provide a better default ->get_required_mask") Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Acked-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/iommu/intel-iommu.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 3f974919d3bd..79e35b3180ac 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3471,7 +3471,7 @@ static bool iommu_need_mapping(struct device *dev)
if (dev->coherent_dma_mask && dev->coherent_dma_mask < dma_mask)
dma_mask = dev->coherent_dma_mask;
- if (dma_mask >= dma_get_required_mask(dev))
+ if (dma_mask >= dma_direct_get_required_mask(dev))
return false;
/*
@@ -3775,6 +3775,13 @@ static int intel_map_sg(struct device *dev, struct scatterlist *sglist, int nele
return nelems;
}
+static u64 intel_get_required_mask(struct device *dev)
+{
+ if (!iommu_need_mapping(dev))
+ return dma_direct_get_required_mask(dev);
+ return DMA_BIT_MASK(32);
+}
+
static const struct dma_map_ops intel_dma_ops = {
.alloc = intel_alloc_coherent,
.free = intel_free_coherent,
@@ -3787,6 +3794,7 @@ static const struct dma_map_ops intel_dma_ops = {
.dma_supported = dma_direct_supported,
.mmap = dma_common_mmap,
.get_sgtable = dma_common_get_sgtable,
+ .get_required_mask = intel_get_required_mask,
};
static void