>From 074e8cc145dde514427c40124913a90c4552dd6e Mon Sep 17 00:00:00 2001 From: Arvind Sankar Date: Mon, 7 Oct 2019 14:19:12 -0400 Subject: [PATCH] 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. Fixes: 249baa547901 ("dma-mapping: provide a better default ->get_required_mask") Signed-off-by: Arvind Sankar --- drivers/iommu/intel-iommu.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) 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 -- 2.21.0