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authorAlexander Duyck <alexander.h.duyck@intel.com>2016-12-15 02:05:06 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-15 03:04:07 +0300
commitf50a2bd298b47e1957f67f794aed90f2c3bd9a10 (patch)
tree606dc2c3fd59a7f52f15a77730bf52e595f1ee77 /arch/parisc
parent043b42bcbbc6bc87c457b156041d74d51f6cebc2 (diff)
downloadlinux-f50a2bd298b47e1957f67f794aed90f2c3bd9a10.tar.xz
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@ahduyck-blue-test.jf.intel.com Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/parisc')
-rw-r--r--arch/parisc/kernel/pci-dma.c20
1 files changed, 15 insertions, 5 deletions
diff --git a/arch/parisc/kernel/pci-dma.c b/arch/parisc/kernel/pci-dma.c
index 494ff6e8c88a..b6298a85e8ae 100644
--- a/arch/parisc/kernel/pci-dma.c
+++ b/arch/parisc/kernel/pci-dma.c
@@ -459,7 +459,9 @@ static dma_addr_t pa11_dma_map_page(struct device *dev, struct page *page,
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 device *dev, dma_addr_t dma_handle,
{
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 device *dev, dma_addr_t dma_handle,
*/
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 *dev, struct scatterlist *sglist,
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 device *dev, struct scatterlist *sglist,
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,