dma-ops: Remove flush_write_buffers() in dma-mapping-common.h

This moves flush_write_buffers() in
asm-generic/dma-mapping-common.h to
arch/x86/kernel/pci-nommu.c.

The purpose of this patch is that, we can avoid defining NULL
flush_write_buffers() on IA64 and SPARC.

dma-mapping-common.h is used by X86 and IA64 (and SPARC soon)
but only X86 with CONFIG_X86_OOSTORE or CONFIG_X86_PPRO_FENCE
actually uses flush_write_buffers(). CONFIG_X86_OOSTORE or
CONFIG_X86_PPRO_FENCE is usable with only kernel/pci-nommu.c
(that is, not usable with other X86 IOMMU implementations such
as SWIOTLB, VT-d, etc) so we can safely move
flush_write_buffers() in asm-generic/dma-mapping-common.h to
arch/x86/kernel/pci-nommu.c.

The further discussion is:

  http://lkml.org/lkml/2009/6/28/104

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: davem@davemloft.net
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
LKML-Reference: <1249872797-1314-2-git-send-email-fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 22 insertions, 5 deletions

diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
index c0a4222bf62b..a3933d4330cd 100644
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -79,12 +79,29 @@ static void nommu_free_coherent(struct device *dev, size_t size, void *vaddr,
         free_pages((unsigned long)vaddr, get_order(size));
 }
 
+static void nommu_sync_single_for_device(struct device *dev,
+                        dma_addr_t addr, size_t size,
+                        enum dma_data_direction dir)
+{
+        flush_write_buffers();
+}
+
+
+static void nommu_sync_sg_for_device(struct device *dev,
+                        struct scatterlist *sg, int nelems,
+                        enum dma_data_direction dir)
+{
+        flush_write_buffers();
+}
+
 struct dma_map_ops nommu_dma_ops = {
-        .alloc_coherent = dma_generic_alloc_coherent,
-        .free_coherent  = nommu_free_coherent,
-        .map_sg         = nommu_map_sg,
-        .map_page       = nommu_map_page,
-        .is_phys        = 1,
+        .alloc_coherent         = dma_generic_alloc_coherent,
+        .free_coherent          = nommu_free_coherent,
+        .map_sg                 = nommu_map_sg,
+        .map_page               = nommu_map_page,
+        .sync_single_for_device = nommu_sync_single_for_device,
+        .sync_sg_for_device     = nommu_sync_sg_for_device,
+        .is_phys                = 1,
 };
 
 void __init no_iommu_init(void)