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