From: Robin Murphy Date: Wed, 25 Jan 2017 18:31:31 +0000 (+0000) Subject: arm64: dma-mapping: Fix dma_mapping_error() when bypassing SWIOTLB X-Git-Tag: v4.11-rc1~120^2~33 X-Git-Url: https://git.kernelconcepts.de/?p=karo-tx-linux.git;a=commitdiff_plain;h=adbe7e26f4257f72817495b9bce114284060b0d7 arm64: dma-mapping: Fix dma_mapping_error() when bypassing SWIOTLB 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 Reported-by: Aaro Koskinen Signed-off-by: Robin Murphy Signed-off-by: Will Deacon --- diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 0ec1ae933342..7ce2b78a72b9 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -356,6 +356,13 @@ 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, @@ -370,7 +377,7 @@ 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)