Commit 4bfa135a authored Dec 14, 2016 by Alexander Duyck Committed by Linus Torvalds Dec 14, 2016

arch/xtensa: add option to skip DMA sync as a part of mapping

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/20161110113555.76501.52536.stgit@ahduyck-blue-test.jf.intel.com

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 33c77e53

arch/xtensa/kernel/pci-dma.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -189,7 +189,9 @@ static dma_addr_t xtensa_map_page(struct device dev, struct page page,
		{
		dma_addr_t dma_handle = page_to_phys(page) + offset;

		if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
		xtensa_sync_single_for_device(dev, dma_handle, size, dir);

		return dma_handle;
		}

		@@ -197,6 +199,7 @@ static void xtensa_unmap_page(struct device *dev, dma_addr_t dma_handle,
		size_t size, enum dma_data_direction dir,
		unsigned long attrs)
		{
		if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
		xtensa_sync_single_for_cpu(dev, dma_handle, size, dir);
		}