[net-next PATCH RFC 08/26] arch/frv: Add option to skip sync on DMA map

[Alexander Duyck]

The use of DMA_ATTR_SKIP_CPU_SYNC was not consistent across all of the DMA
APIs in the arch/arm folder.  This change is meant to correct that so that
we get consistent behavior.

Signed-off-by: Alexander Duyck <alexander.h.du...@intel.com>
---
 arch/frv/mb93090-mb00/pci-dma-nommu.c |   16 +++++++++++-----
 arch/frv/mb93090-mb00/pci-dma.c       |    7 ++++++-
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/arch/frv/mb93090-mb00/pci-dma-nommu.c 
b/arch/frv/mb93090-mb00/pci-dma-nommu.c
index 90f2e4c..ff606d1 100644
--- a/arch/frv/mb93090-mb00/pci-dma-nommu.c
+++ b/arch/frv/mb93090-mb00/pci-dma-nommu.c
@@ -109,16 +109,19 @@ static int frv_dma_map_sg(struct device *dev, struct 
scatterlist *sglist,
                int nents, enum dma_data_direction direction,
                unsigned long attrs)
 {
-       int i;
        struct scatterlist *sg;
+       int i;
+
+       WARN_ON(direction == DMA_NONE);
+
+       if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+               return nents;
 
        for_each_sg(sglist, sg, nents, i) {
                frv_cache_wback_inv(sg_dma_address(sg),
                                    sg_dma_address(sg) + sg_dma_len(sg));
        }
 
-       BUG_ON(direction == DMA_NONE);
-
        return nents;
 }
 
@@ -126,8 +129,11 @@ static dma_addr_t frv_dma_map_page(struct device *dev, 
struct page *page,
                unsigned long offset, size_t size,
                enum dma_data_direction direction, unsigned long attrs)
 {
-       BUG_ON(direction == DMA_NONE);
-       flush_dcache_page(page);
+       WARN_ON(direction == DMA_NONE);
+
+       if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+               flush_dcache_page(page);
+
        return (dma_addr_t) page_to_phys(page) + offset;
 }
 
diff --git a/arch/frv/mb93090-mb00/pci-dma.c b/arch/frv/mb93090-mb00/pci-dma.c
index f585745..ee5dadf 100644
--- a/arch/frv/mb93090-mb00/pci-dma.c
+++ b/arch/frv/mb93090-mb00/pci-dma.c
@@ -52,6 +52,9 @@ static int frv_dma_map_sg(struct device *dev, struct 
scatterlist *sglist,
        for_each_sg(sglist, sg, nents, i) {
                vaddr = kmap_atomic_primary(sg_page(sg));
 
+               if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+                       continue;
+
                frv_dcache_writeback((unsigned long) vaddr,
                                     (unsigned long) vaddr + PAGE_SIZE);
 
@@ -70,7 +73,9 @@ static dma_addr_t frv_dma_map_page(struct device *dev, struct 
page *page,
                unsigned long offset, size_t size,
                enum dma_data_direction direction, unsigned long attrs)
 {
-       flush_dcache_page(page);
+       if (!(attr & DMA_ATTR_SKIP_CPU_SYNC))
+               flush_dcache_page(page);
+
        return (dma_addr_t) page_to_phys(page) + offset;
 }