+ arch-c6x-add-option-to-skip-sync-on-dma-map-and-unmap.patch added to -mm tree

+ arch-c6x-add-option-to-skip-sync-on-dma-map-and-unmap.patch added to -mm tree

[akpm]

The patch titled
     Subject: arch/c6x: add option to skip sync on DMA map and unmap
has been added to the -mm tree.  Its filename is
     arch-c6x-add-option-to-skip-sync-on-dma-map-and-unmap.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/arch-c6x-add-option-to-skip-sync-on-dma-map-and-unmap.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/arch-c6x-add-option-to-skip-sync-on-dma-map-and-unmap.patch

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------------------------------------------------------
From: Alexander Duyck <alexander.h.duyck@intel.com>
Subject: arch/c6x: add option to skip sync on DMA 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
later via a sync_for_cpu or sync_for_device call.

Link: http://lkml.kernel.org/r/20161110113442.76501.7673.stgit@ahduyck-blue-test.jf.intel.com
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/c6x/kernel/dma.c |   14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff -puN arch/c6x/kernel/dma.c~arch-c6x-add-option-to-skip-sync-on-dma-map-and-unmap arch/c6x/kernel/dma.c
--- a/arch/c6x/kernel/dma.c~arch-c6x-add-option-to-skip-sync-on-dma-map-and-unmap
+++ a/arch/c6x/kernel/dma.c
@@ -42,14 +42,17 @@ static dma_addr_t c6x_dma_map_page(struc
 {
 	dma_addr_t handle = virt_to_phys(page_address(page) + offset);
 
-	c6x_dma_sync(handle, size, dir);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		c6x_dma_sync(handle, size, dir);
+
 	return handle;
 }
 
 static void c6x_dma_unmap_page(struct device *dev, dma_addr_t handle,
 		size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
-	c6x_dma_sync(handle, size, dir);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		c6x_dma_sync(handle, size, dir);
 }
 
 static int c6x_dma_map_sg(struct device *dev, struct scatterlist *sglist,
@@ -60,7 +63,8 @@ static int c6x_dma_map_sg(struct device
 
 	for_each_sg(sglist, sg, nents, i) {
 		sg->dma_address = sg_phys(sg);
-		c6x_dma_sync(sg->dma_address, sg->length, dir);
+		if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+			c6x_dma_sync(sg->dma_address, sg->length, dir);
 	}
 
 	return nents;
@@ -72,9 +76,11 @@ static void c6x_dma_unmap_sg(struct devi
 	struct scatterlist *sg;
 	int i;
 
+	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+		return;
+
 	for_each_sg(sglist, sg, nents, i)
 		c6x_dma_sync(sg_dma_address(sg), sg->length, dir);
-
 }
 
 static void c6x_dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle,
_

Patches currently in -mm which might be from alexander.h.duyck@intel.com are

arch-arc-add-option-to-skip-sync-on-dma-mapping.patch
arch-arm-add-option-to-skip-sync-on-dma-map-and-unmap.patch
arch-avr32-add-option-to-skip-sync-on-dma-map.patch
arch-blackfin-add-option-to-skip-sync-on-dma-map.patch
arch-c6x-add-option-to-skip-sync-on-dma-map-and-unmap.patch
arch-frv-add-option-to-skip-sync-on-dma-map.patch
arch-hexagon-add-option-to-skip-dma-sync-as-a-part-of-mapping.patch
arch-m68k-add-option-to-skip-dma-sync-as-a-part-of-mapping.patch
arch-metag-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap.patch
arch-microblaze-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap.patch
arch-mips-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap.patch
arch-nios2-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap.patch
arch-openrisc-add-option-to-skip-dma-sync-as-a-part-of-mapping.patch
arch-parisc-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap.patch
arch-powerpc-add-option-to-skip-dma-sync-as-a-part-of-mapping.patch
arch-sh-add-option-to-skip-dma-sync-as-a-part-of-mapping.patch
arch-sparc-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap.patch
arch-tile-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap.patch
arch-xtensa-add-option-to-skip-dma-sync-as-a-part-of-mapping.patch
dma-add-calls-for-dma_map_page_attrs-and-dma_unmap_page_attrs.patch
mm-add-support-for-releasing-multiple-instances-of-a-page.patch
igb-update-driver-to-make-use-of-dma_attr_skip_cpu_sync.patch
igb-update-code-to-better-handle-incrementing-page-count.patch