From: David Stevens <stevensd@chromium.org>
To: Robin Murphy <robin.murphy@arm.com>, Will Deacon <will@kernel.org>
Cc: Joerg Roedel <joro@8bytes.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 v3 3/5] dma-iommu: add SKIP_CPU_SYNC after syncing
Date: Wed, 11 Aug 2021 11:42:45 +0900 [thread overview]
Message-ID: <20210811024247.1144246-4-stevensd@google.com> (raw)
In-Reply-To: <20210811024247.1144246-1-stevensd@google.com>
From: David Stevens <stevensd@chromium.org>
After syncing in map/unmap, add the DMA_ATTR_SKIP_CPU_SYNC flag so
anything that uses attrs later on will skip any sync work that has
already been completed. In particular, this skips copying from the
swiotlb twice during unmap.
Signed-off-by: David Stevens <stevensd@chromium.org>
---
drivers/iommu/dma-iommu.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 4f0cc4a0a61f..be0214b1455c 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -859,8 +859,11 @@ static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
static void iommu_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction dir, unsigned long attrs)
{
- if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
iommu_dma_sync_single_for_cpu(dev, dma_handle, size, dir);
+ attrs |= DMA_ATTR_SKIP_CPU_SYNC;
+ }
+
__iommu_dma_unmap_swiotlb(dev, dma_handle, size, dir, attrs);
}
@@ -999,8 +1002,10 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
if (dev_is_untrusted(dev))
return iommu_dma_map_sg_swiotlb(dev, sg, nents, dir, attrs);
- if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
iommu_dma_sync_sg_for_device(dev, sg, nents, dir);
+ attrs |= DMA_ATTR_SKIP_CPU_SYNC;
+ }
/*
* Work out how much IOVA space we need, and align the segments to
@@ -1068,8 +1073,10 @@ static void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
struct scatterlist *tmp;
int i;
- if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
iommu_dma_sync_sg_for_cpu(dev, sg, nents, dir);
+ attrs |= DMA_ATTR_SKIP_CPU_SYNC;
+ }
if (dev_is_untrusted(dev)) {
iommu_dma_unmap_sg_swiotlb(dev, sg, nents, dir, attrs);
--
2.32.0.605.g8dce9f2422-goog
next prev parent reply other threads:[~2021-08-11 2:44 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-11 2:42 [PATCH v3 0/5] Fixes for dma-iommu swiotlb bounce buffers David Stevens
2021-08-11 2:42 ` [PATCH v3 1/5] dma-iommu: fix sync_sg with swiotlb David Stevens
2021-08-11 5:57 ` Christoph Hellwig
2021-08-11 18:22 ` Robin Murphy
2021-08-11 2:42 ` [PATCH v3 2/5] dma-iommu: fix arch_sync_dma for map David Stevens
2021-08-11 6:01 ` Christoph Hellwig
2021-08-11 18:47 ` Robin Murphy
2021-08-12 9:21 ` David Stevens
2021-08-12 10:38 ` Robin Murphy
2021-08-11 2:42 ` David Stevens [this message]
2021-08-11 6:07 ` [PATCH v3 3/5] dma-iommu: add SKIP_CPU_SYNC after syncing Christoph Hellwig
2021-08-11 19:00 ` Robin Murphy
2021-08-11 2:42 ` [PATCH v3 4/5] dma-iommu: Check CONFIG_SWIOTLB more broadly David Stevens
2021-08-11 19:02 ` Robin Murphy
2021-08-11 2:42 ` [PATCH v3 5/5] dma-iommu: account for min_align_mask David Stevens
2021-08-11 9:26 ` Mi, Dapeng1
2021-08-11 19:12 ` Robin Murphy
2021-08-12 1:45 ` David Stevens
2021-08-12 9:57 ` Robin Murphy
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