Commit adbe7e26 authored Jan 25, 2017 by Robin Murphy Committed by Will Deacon Jan 26, 2017

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: b67a8b29 ("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>
Signed-off-by: Will Deacon <will.deacon@arm.com>

parent 2e449048

arch/arm64/mm/dma-mapping.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -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)