The patch titled
Subject: arch/metag: add option to skip DMA sync as a part of map and unmap
has been added to the -mm tree. Its filename is
arch-metag-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-metag-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-metag-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap.patch
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------------------------------------------------------
From: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>
Subject: arch/metag: 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/20161110113503.76501.80809.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>
Cc: James Hogan <james.hogan@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/metag/kernel/dma.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff -puN arch/metag/kernel/dma.c~arch-metag-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap arch/metag/kernel/dma.c
--- a/arch/metag/kernel/dma.c~arch-metag-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap
+++ a/arch/metag/kernel/dma.c
@@ -484,8 +484,9 @@ static dma_addr_t metag_dma_map_page(str
unsigned long offset, size_t size,
enum dma_data_direction direction, unsigned long attrs)
{
- dma_sync_for_device((void *)(page_to_phys(page) + offset), size,
- direction);
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ dma_sync_for_device((void *)(page_to_phys(page) + offset),
+ size, direction);
return page_to_phys(page) + offset;
}
@@ -493,7 +494,8 @@ static void metag_dma_unmap_page(struct
size_t size, enum dma_data_direction direction,
unsigned long attrs)
{
- dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);
}
static int metag_dma_map_sg(struct device *dev, struct scatterlist *sglist,
@@ -507,6 +509,10 @@ static int metag_dma_map_sg(struct devic
BUG_ON(!sg_page(sg));
sg->dma_address = sg_phys(sg);
+
+ if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+ continue;
+
dma_sync_for_device(sg_virt(sg), sg->length, direction);
}
@@ -525,6 +531,10 @@ static void metag_dma_unmap_sg(struct de
BUG_ON(!sg_page(sg));
sg->dma_address = sg_phys(sg);
+
+ if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+ continue;
+
dma_sync_for_cpu(sg_virt(sg), sg->length, direction);
}
}
_
Patches currently in -mm which might be from alexander.h.duyck@xxxxxxxxx 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
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