From 06f55fd2d22742ed7e725124dfea68936d12ce40 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Fri, 4 Jan 2019 09:50:33 +0100
Subject: [PATCH] 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 <mkubecek@suse.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Michal Kubecek <mkubecek@suse.cz>
---
arch/x86/kernel/amd_gart_64.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c
index e0ff3ac8c1274..2c0aa34af69c5 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;
--
GitLab