+ arch-parisc-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap.patch added to -mm tree

+ arch-parisc-add-option-to-skip-dma-sync-as-a-part-of-map-and-unmap.patch added to -mm tree

[akpm]

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@intel.com>
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@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>
---

 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@intel.com 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