diff options
Diffstat (limited to 'arm64-dma-mapping-Fix-dma_mapping_error-when-bypassing-SWIOTLB.patch')
| -rw-r--r-- | arm64-dma-mapping-Fix-dma_mapping_error-when-bypassing-SWIOTLB.patch | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/arm64-dma-mapping-Fix-dma_mapping_error-when-bypassing-SWIOTLB.patch b/arm64-dma-mapping-Fix-dma_mapping_error-when-bypassing-SWIOTLB.patch new file mode 100644 index 000000000..2e7f51ec6 --- /dev/null +++ b/arm64-dma-mapping-Fix-dma_mapping_error-when-bypassing-SWIOTLB.patch @@ -0,0 +1,66 @@ +From patchwork Wed Jan 25 18:31:31 2017 +Content-Type: text/plain; charset="utf-8" +MIME-Version: 1.0 +Content-Transfer-Encoding: 7bit +Subject: [v2] arm64: dma-mapping: Fix dma_mapping_error() when bypassing + SWIOTLB +From: Robin Murphy <robin.murphy@arm.com> +X-Patchwork-Id: 9537723 +Message-Id: <840027acb4750542003dff17b4a8902ba8972754.1485368348.git.robin.murphy@arm.com> +To: will.deacon@arm.com, + catalin.marinas@arm.com +Cc: Jisheng Zhang <jszhang@marvell.com>, arnd@arndb.de, + konrad.wilk@oracle.com, aaro.koskinen@iki.fi, stable@vger.kernel.org, + linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org +Date: Wed, 25 Jan 2017 18:31:31 +0000 + +When bypassing SWIOTLB on small-memory systems, we need to avoid calling +into swiotlb_dma_mapping_error() in exactly the same way as we avoid +swiotlb_dma_supported(), because the former also relies on SWIOTLB state +being initialised. + +Under the assumptions for which we skip SWIOTLB, dma_map_{single,page}() +will only ever return the DMA-offset-adjusted physical address of the +page passed in, thus we can report success unconditionally. + +Fixes: b67a8b29df7e ("arm64: mm: only initialize swiotlb when necessary") +CC: stable@vger.kernel.org +CC: Jisheng Zhang <jszhang@marvell.com> +Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi> +Signed-off-by: Robin Murphy <robin.murphy@arm.com> +Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi> +--- + +v2: Get the return value the right way round this time... After some + careful reasoning it really is that simple. + + arch/arm64/mm/dma-mapping.c | 9 ++++++++- + 1 file changed, 8 insertions(+), 1 deletion(-) + +diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c +index e04082700bb1..1ffb7d5d299a 100644 +--- a/arch/arm64/mm/dma-mapping.c ++++ b/arch/arm64/mm/dma-mapping.c +@@ -352,6 +352,13 @@ static int __swiotlb_dma_supported(struct device *hwdev, u64 mask) + return 1; + } + ++static int __swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t addr) ++{ ++ if (swiotlb) ++ return swiotlb_dma_mapping_error(hwdev, addr); ++ return 0; ++} ++ + static struct dma_map_ops swiotlb_dma_ops = { + .alloc = __dma_alloc, + .free = __dma_free, +@@ -366,7 +373,7 @@ static struct dma_map_ops swiotlb_dma_ops = { + .sync_sg_for_cpu = __swiotlb_sync_sg_for_cpu, + .sync_sg_for_device = __swiotlb_sync_sg_for_device, + .dma_supported = __swiotlb_dma_supported, +- .mapping_error = swiotlb_dma_mapping_error, ++ .mapping_error = __swiotlb_dma_mapping_error, + }; + + static int __init atomic_pool_init(void) |