From 4bfa135abec99f4b35b5636f56a6db75ce3c64d7 Mon Sep 17 00:00:00 2001
From: Alexander Duyck <alexander.h.duyck@intel.com>
Date: Wed, 14 Dec 2016 15:05:21 -0800
Subject: [PATCH] arch/xtensa: add option to skip DMA sync as a part of mapping
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to
avoid invoking cache line invalidation if the driver will just handle it
via a sync_for_cpu or sync_for_device call.
Link: http://lkml.kernel.org/r/20161110113555.76501.52536.stgit@ahduyck-blue-test.jf.intel.com
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
arch/xtensa/kernel/pci-dma.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c
index 1e68806d6695a..6a16decf278fa 100644
--- a/arch/xtensa/kernel/pci-dma.c
+++ b/arch/xtensa/kernel/pci-dma.c
@@ -189,7 +189,9 @@ static dma_addr_t xtensa_map_page(struct device *dev, struct page *page,
{
dma_addr_t dma_handle = page_to_phys(page) + offset;
- xtensa_sync_single_for_device(dev, dma_handle, size, dir);
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ xtensa_sync_single_for_device(dev, dma_handle, size, dir);
+
return dma_handle;
}
@@ -197,7 +199,8 @@ static void xtensa_unmap_page(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
- xtensa_sync_single_for_cpu(dev, dma_handle, size, dir);
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ xtensa_sync_single_for_cpu(dev, dma_handle, size, dir);
}
static int xtensa_map_sg(struct device *dev, struct scatterlist *sg,
--
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