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

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  [net-next PATCH 16/27] arch/openrisc: Add option to skip DMA sync  as a part of mapping Alexander Duyck <alexander.h.duyck@intel.com> - 2016-10-25 23:40 +0200

#1508660 — [net-next PATCH 16/27] 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.

Cc: Jonas Bonn <jonas@southpole.se>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
 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 */

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