From 98ac2fc274e07a22bea43682cf8998f47ffea9d0 Mon Sep 17 00:00:00 2001
From: Alexander Duyck <alexander.h.duyck@intel.com>
Date: Wed, 14 Dec 2016 15:04:55 -0800
Subject: [PATCH] arch/microblaze: add option to skip DMA sync as a part of map
and unmap
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/20161110113508.76501.77583.stgit@ahduyck-blue-test.jf.intel.com
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Michal Simek <monstr@monstr.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
arch/microblaze/kernel/dma.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/microblaze/kernel/dma.c b/arch/microblaze/kernel/dma.c
index ec04dc1e2527a..818daf230eb4e 100644
--- a/arch/microblaze/kernel/dma.c
+++ b/arch/microblaze/kernel/dma.c
@@ -61,6 +61,10 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
/* FIXME this part of code is untested */
for_each_sg(sgl, sg, nents, i) {
sg->dma_address = sg_phys(sg);
+
+ if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+ continue;
+
__dma_sync(page_to_phys(sg_page(sg)) + sg->offset,
sg->length, direction);
}
@@ -80,7 +84,8 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev,
enum dma_data_direction direction,
unsigned long attrs)
{
- __dma_sync(page_to_phys(page) + offset, size, direction);
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ __dma_sync(page_to_phys(page) + offset, size, direction);
return page_to_phys(page) + offset;
}
@@ -95,7 +100,8 @@ static inline void dma_direct_unmap_page(struct device *dev,
* phys_to_virt is here because in __dma_sync_page is __virt_to_phys and
* dma_address is physical address
*/
- __dma_sync(dma_address, size, direction);
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ __dma_sync(dma_address, size, direction);
}
static inline void
--
GitLab