Thread (38 messages) 38 messages, 7 authors, 2016-10-28

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

From: Alexander Duyck <hidden>
Date: 2016-10-25 21:38:56
Also in: intel-wired-lan, linux-mm, lkml
Subsystem: openrisc architecture, the rest · Maintainers: Jonas Bonn, Stefan Kristiansson, Stafford Horne, Linus Torvalds

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 <redacted>
---
 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 */

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help