[net-next PATCH 16/27] arch/openrisc: Add option to skip DMA sync as a part of mapping

From: Alexander Duyck
Date: Tue Oct 25 2016 - 17:39:00 EST


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.

Cc: Jonas Bonn <jonas@xxxxxxxxxxxx>
Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>
---
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 140c991..906998b 100644
--- a/arch/openrisc/kernel/dma.c
+++ b/arch/openrisc/kernel/dma.c
@@ -141,6 +141,9 @@
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 */