Hi Murali, On 23/01/15 22:32, Murali Karicheri wrote:
Limit the dma_mask to minimum of dma_mask and dma_base + size - 1. Also arm_iommu_create_mapping() has size parameter of size_t and arm_setup_iommu_dma_ops() can take a value higher than that. So limit the size to SIZE_MAX. Signed-off-by: Murali Karicheri <m-karicheri2@xxxxxx> --- arch/arm/mm/dma-mapping.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 7864797..a1f9030 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -2004,6 +2004,13 @@ static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size, if (!iommu) return false; + /* + * currently arm_iommu_create_mapping() takes a max of size_t + * for size param. So check this limit for now. + */ + if (size > SIZE_MAX) + return false; + mapping = arm_iommu_create_mapping(dev->bus, dma_base, size); if (IS_ERR(mapping)) { pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n", @@ -2053,6 +2060,9 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, { struct dma_map_ops *dma_ops; + /* limit dma_mask to the lower of the two values */ + *dev->dma_mask = min((*dev->dma_mask), (dma_base + size - 1)); +
Is there any reason not to do this in of_dma_configure? It seems like something everyone could benefit from - I'd cooked up a dodgy workaround for the same issue in my arm64 IOMMU code, but handling it generically in common code would be much nicer.
Robin.
dev->archdata.dma_coherent = coherent; if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu)) dma_ops = arm_get_iommu_dma_map_ops(coherent);
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