diff options
| author |   Alexander Duyck <alexander.h.duyck@intel.com> | 2016-12-14 15:05:06 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-14 16:04:07 -0800 |
| commit | f50a2bd298b47e1957f67f794aed90f2c3bd9a10 (patch) | |
| tree | 606dc2c3fd59a7f52f15a77730bf52e595f1ee77 /arch | |
| parent | arch/openrisc: add option to skip DMA sync as a part of mapping (diff) | |
| download | linux-dev-f50a2bd298b47e1957f67f794aed90f2c3bd9a10.tar.xz linux-dev-f50a2bd298b47e1957f67f794aed90f2c3bd9a10.zip | |
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')
| -rw-r--r-- | arch/parisc/kernel/pci-dma.c | 20 |
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, |