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authorRobin Murphy <robin.murphy@arm.com>2018-07-23 23:16:10 +0100
committerChristoph Hellwig <hch@lst.de>2018-07-27 19:01:06 +0200
commit03bfdc31176cbe21e456f889ccbbf67568831149 (patch)
tree25ae917520c023e69f0ccb71b71d56c20198592e /drivers/iommu
parent6c2fb2ea76361da9b420a8e23a2a19e7842cbdda (diff)
iommu/dma: Respect bus DMA limit for IOVAs
Take the new bus limit into account (when present) for IOVA allocations, to accommodate those SoCs which integrate off-the-shelf IP blocks with narrower interconnects such that the link between a device output and an IOMMU input can truncate DMA addresses to even fewer bits than the native size of either block's interface would imply. Eventually it might make sense for the DMA core to apply this constraint up-front in dma_set_mask() and friends, but for now this seems like the least risky approach. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/dma-iommu.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index ddcbbdb5d658..511ff9a1d6d9 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -367,6 +367,9 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
if (iova_len < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
iova_len = roundup_pow_of_two(iova_len);
+ if (dev->bus_dma_mask)
+ dma_limit &= dev->bus_dma_mask;
+
if (domain->geometry.force_aperture)
dma_limit = min(dma_limit, domain->geometry.aperture_end);