+ arch-mips-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap.patch added to -mm tree

+ arch-mips-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap.patch added to -mm tree

[akpm]

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

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

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/SubmitChecklist when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

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

Link: http://lkml.kernel.org/r/20161110113513.76501.32321.stgit@ahduyck-blue-test.jf.intel.com
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Keguang Zhang <keguang.zhang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/mips/loongson64/common/dma-swiotlb.c |    2 +-
 arch/mips/mm/dma-default.c                |    8 +++++---
 2 files changed, 6 insertions(+), 4 deletions(-)

diff -puN arch/mips/loongson64/common/dma-swiotlb.c~arch-mips-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap arch/mips/loongson64/common/dma-swiotlb.c
--- a/arch/mips/loongson64/common/dma-swiotlb.c~arch-mips-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap
+++ a/arch/mips/loongson64/common/dma-swiotlb.c
@@ -61,7 +61,7 @@ static int loongson_dma_map_sg(struct de
 				int nents, enum dma_data_direction dir,
 				unsigned long attrs)
 {
-	int r = swiotlb_map_sg_attrs(dev, sg, nents, dir, 0);
+	int r = swiotlb_map_sg_attrs(dev, sg, nents, dir, attrs);
 	mb();
 
 	return r;
diff -puN arch/mips/mm/dma-default.c~arch-mips-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap arch/mips/mm/dma-default.c
--- a/arch/mips/mm/dma-default.c~arch-mips-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap
+++ a/arch/mips/mm/dma-default.c
@@ -293,7 +293,7 @@ static inline void __dma_sync(struct pag
 static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
 	size_t size, enum dma_data_direction direction, unsigned long attrs)
 {
-	if (cpu_needs_post_dma_flush(dev))
+	if (cpu_needs_post_dma_flush(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 		__dma_sync(dma_addr_to_page(dev, dma_addr),
 			   dma_addr & ~PAGE_MASK, size, direction);
 	plat_post_dma_flush(dev);
@@ -307,7 +307,8 @@ static int mips_dma_map_sg(struct device
 	struct scatterlist *sg;
 
 	for_each_sg(sglist, sg, nents, i) {
-		if (!plat_device_is_coherent(dev))
+		if (!plat_device_is_coherent(dev) &&
+		    !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 			__dma_sync(sg_page(sg), sg->offset, sg->length,
 				   direction);
 #ifdef CONFIG_NEED_SG_DMA_LENGTH
@@ -324,7 +325,7 @@ static dma_addr_t mips_dma_map_page(stru
 	unsigned long offset, size_t size, enum dma_data_direction direction,
 	unsigned long attrs)
 {
-	if (!plat_device_is_coherent(dev))
+	if (!plat_device_is_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 		__dma_sync(page, offset, size, direction);
 
 	return plat_map_dma_mem_page(dev, page) + offset;
@@ -339,6 +340,7 @@ static void mips_dma_unmap_sg(struct dev
 
 	for_each_sg(sglist, sg, nhwentries, i) {
 		if (!plat_device_is_coherent(dev) &&
+		    !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
 		    direction != DMA_TO_DEVICE)
 			__dma_sync(sg_page(sg), sg->offset, sg->length,
 				   direction);
_

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