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From: David Stevens <stevensd@chromium.org>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
	Lu Baolu <baolu.lu@linux.intel.com>, Tom Murphy <murphyt7@tcd.ie>,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	David Stevens <stevensd@chromium.org>
Subject: [PATCH v2 3/4] dma-iommu: pass SKIP_CPU_SYNC to swiotlb unmap
Date: Fri,  9 Jul 2021 12:35:01 +0900	[thread overview]
Message-ID: <20210709033502.3545820-4-stevensd@google.com> (raw)
In-Reply-To: <20210709033502.3545820-1-stevensd@google.com>

From: David Stevens <stevensd@chromium.org>

If SKIP_CPU_SYNC isn't already set, then iommu_dma_unmap_(page|sg) has
already called iommu_dma_sync_(single|sg)_for_cpu, so there is no need
to copy from the bounce buffer again.

Signed-off-by: David Stevens <stevensd@chromium.org>
---
 drivers/iommu/dma-iommu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index e79e274d2dc5..0a9a9a343e64 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -505,7 +505,8 @@ static void __iommu_dma_unmap_swiotlb(struct device *dev, dma_addr_t dma_addr,
 	__iommu_dma_unmap(dev, dma_addr, size);
 
 	if (unlikely(is_swiotlb_buffer(phys)))
-		swiotlb_tbl_unmap_single(dev, phys, size, dir, attrs);
+		swiotlb_tbl_unmap_single(dev, phys, size, dir,
+					 attrs | DMA_ATTR_SKIP_CPU_SYNC);
 }
 
 static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
-- 
2.32.0.93.g670b81a890-goog


  parent reply	other threads:[~2021-07-09  3:35 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-09  3:34 [PATCH v2 0/4] Fixes for dma-iommu swiotlb bounce buffers David Stevens
2021-07-09  3:34 ` [PATCH v2 1/4] dma-iommu: fix sync_sg with swiotlb David Stevens
2021-08-02 13:30   ` Will Deacon
2021-08-05  3:40     ` David Stevens
2021-07-09  3:35 ` [PATCH v2 2/4] dma-iommu: fix arch_sync_dma for map " David Stevens
2021-08-02 13:40   ` Will Deacon
2021-08-02 13:50     ` Will Deacon
2021-07-09  3:35 ` David Stevens [this message]
2021-08-02 13:54   ` [PATCH v2 3/4] dma-iommu: pass SKIP_CPU_SYNC to swiotlb unmap Will Deacon
2021-08-05  5:26     ` David Stevens
2021-08-06 11:38       ` Will Deacon
2021-07-09  3:35 ` [PATCH v2 4/4] dma-iommu: Check CONFIG_SWIOTLB more broadly David Stevens

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