From: Christoph Hellwig Date: Fri, 4 Jan 2019 08:50:33 +0000 (+0100) Subject: x86/amd_gart: fix unmapping of non-GART mappings X-Git-Tag: v5.15~7210^2~1 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=06f55fd2d22742ed7e725124dfea68936d12ce40;p=mirror_ubuntu-kernels.git x86/amd_gart: fix unmapping of non-GART mappings In many cases we don't have to create a GART mapping at all, which also means there is nothing to unmap. Fix the range check that was incorrectly modified when removing the mapping_error method. Fixes: 9e8aa6b546 ("x86/amd_gart: remove the mapping_error dma_map_ops method") Reported-by: Michal Kubecek Signed-off-by: Christoph Hellwig Tested-by: Michal Kubecek --- diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c index e0ff3ac8c127..2c0aa34af69c 100644 --- a/arch/x86/kernel/amd_gart_64.c +++ b/arch/x86/kernel/amd_gart_64.c @@ -256,7 +256,15 @@ static void gart_unmap_page(struct device *dev, dma_addr_t dma_addr, int npages; int i; - if (dma_addr == DMA_MAPPING_ERROR || + if (WARN_ON_ONCE(dma_addr == DMA_MAPPING_ERROR)) + return; + + /* + * This driver will not always use a GART mapping, but might have + * created a direct mapping instead. If that is the case there is + * nothing to unmap here. + */ + if (dma_addr < iommu_bus_base || dma_addr >= iommu_bus_base + iommu_size) return;