The patch titled
Subject: arch/parisc: add option to skip DMA sync as a part of map and unmap
has been added to the -mm tree. Its filename is
arch-parisc-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-parisc-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-parisc-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/parisc: 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/20161110113529.76501.44762.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>
Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/parisc/kernel/pci-dma.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff -puN arch/parisc/kernel/pci-dma.c~arch-parisc-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap arch/parisc/kernel/pci-dma.c
--- a/arch/parisc/kernel/pci-dma.c~arch-parisc-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap
+++ a/arch/parisc/kernel/pci-dma.c
@@ -459,7 +459,9 @@ static dma_addr_t pa11_dma_map_page(stru
void *addr = page_address(page) + offset;
BUG_ON(direction == DMA_NONE);
- flush_kernel_dcache_range((unsigned long) addr, size);
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ flush_kernel_dcache_range((unsigned long) addr, size);
+
return virt_to_phys(addr);
}
@@ -469,8 +471,11 @@ static void pa11_dma_unmap_page(struct d
{
BUG_ON(direction == DMA_NONE);
+ if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+ return;
+
if (direction == DMA_TO_DEVICE)
- return;
+ return;
/*
* For PCI_DMA_FROMDEVICE this flush is not necessary for the
@@ -479,7 +484,6 @@ static void pa11_dma_unmap_page(struct d
*/
flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle), size);
- return;
}
static int pa11_dma_map_sg(struct device *dev, struct scatterlist *sglist,
@@ -496,6 +500,10 @@ static int pa11_dma_map_sg(struct device
sg_dma_address(sg) = (dma_addr_t) virt_to_phys(vaddr);
sg_dma_len(sg) = sg->length;
+
+ if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+ continue;
+
flush_kernel_dcache_range(vaddr, sg->length);
}
return nents;
@@ -510,14 +518,16 @@ static void pa11_dma_unmap_sg(struct dev
BUG_ON(direction == DMA_NONE);
+ if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+ return;
+
if (direction == DMA_TO_DEVICE)
- return;
+ return;
/* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
for_each_sg(sglist, sg, nents, i)
flush_kernel_vmap_range(sg_virt(sg), sg->length);
- return;
}
static void pa11_dma_sync_single_for_cpu(struct device *dev,
_
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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