From: Robin Murphy <robin.murphy@arm.com>
To: hch@lst.de, konrad.wilk@oracle.com
Cc: m.szyprowski@samsung.com, john.stultz@linaro.org,
iommu@lists.linux-foundation.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, sstabellini@kernel.org
Subject: [PATCH v2 2/2] swiotlb: Skip cache maintenance on map error
Date: Wed, 21 Nov 2018 16:00:51 +0000 [thread overview]
Message-ID: <cc6d91acc357235cbd6e0e134382c58caa188801.1542812807.git.robin.murphy@arm.com> (raw)
In-Reply-To: <cover.1542812807.git.robin.murphy@arm.com>
If swiotlb_bounce_page() failed, calling arch_sync_dma_for_device() may
lead to such delights as performing cache maintenance on whatever
address phys_to_virt(SWIOTLB_MAP_ERROR) looks like, which is typically
outside the kernel memory map and goes about as well as expected.
Don't do that.
Fixes: a4a4330db46a ("swiotlb: add support for non-coherent DMA")
Tested-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
v2: Collect tags
kernel/dma/swiotlb.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 5731daa09a32..045930e32c0e 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -679,7 +679,8 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
}
if (!dev_is_dma_coherent(dev) &&
- (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
+ (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0 &&
+ dev_addr != DIRECT_MAPPING_ERROR)
arch_sync_dma_for_device(dev, phys, size, dir);
return dev_addr;
--
2.19.1.dirty
next prev parent reply other threads:[~2018-11-21 16:01 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-21 16:00 [PATCH v2 0/2] SWIOTLB fixes for 4.20 Robin Murphy
2018-11-21 16:00 ` [PATCH v2 1/2] dma-direct: Make DIRECT_MAPPING_ERROR viable for SWIOTLB Robin Murphy
2018-11-21 16:00 ` Robin Murphy [this message]
2018-11-27 20:38 ` [PATCH v2 2/2] swiotlb: Skip cache maintenance on map error Stefano Stabellini
2018-11-21 17:49 ` [PATCH v2 0/2] SWIOTLB fixes for 4.20 Christoph Hellwig
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