From 043b42bcbbc6bc87c457b156041d74d51f6cebc2 Mon Sep 17 00:00:00 2001
From: Alexander Duyck <alexander.h.duyck@intel.com>
Date: Wed, 14 Dec 2016 15:05:03 -0800
Subject: [PATCH] arch/openrisc: 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/20161110113524.76501.87966.stgit@ahduyck-blue-test.jf.intel.com
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
arch/openrisc/kernel/dma.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/openrisc/kernel/dma.c b/arch/openrisc/kernel/dma.c
index 140c99140649d..906998bac9575 100644
--- a/arch/openrisc/kernel/dma.c
+++ b/arch/openrisc/kernel/dma.c
@@ -141,6 +141,9 @@ or1k_map_page(struct device *dev, struct page *page,
unsigned long cl;
dma_addr_t addr = page_to_phys(page) + offset;
+ if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+ return addr;
+
switch (dir) {
case DMA_TO_DEVICE:
/* Flush the dcache for the requested range */
--
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