[PATCH -mm] uml: disable CONFIG_HAS_DMA

[FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>]

I think that it's better to detect DMA misuse at build time rather
than calling BUG_ON. Architectures that can't do DMA need to disable
CONFIG_HAS_DMA.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
---
 arch/um/Kconfig.um                |    3 +
 arch/um/defconfig                 |    1 -
 arch/um/include/asm/dma-mapping.h |  112 -------------------------------------
 3 files changed, 3 insertions(+), 113 deletions(-)
 delete mode 100644 arch/um/include/asm/dma-mapping.h

diff --git a/arch/um/Kconfig.um b/arch/um/Kconfig.um
index ec2b8da..3de40b8 100644
--- a/arch/um/Kconfig.um
+++ b/arch/um/Kconfig.um
@@ -147,3 +147,6 @@ config KERNEL_STACK_ORDER
 	  This option determines the size of UML kernel stacks.  They will
 	  be 1 << order pages.  The default is OK unless you're running Valgrind
 	  on UML, in which case, set this to 3.
+
+config HAS_DMA
+       def_bool n
diff --git a/arch/um/defconfig b/arch/um/defconfig
index 6bd456f..564f3de 100644
--- a/arch/um/defconfig
+++ b/arch/um/defconfig
@@ -566,7 +566,6 @@ CONFIG_CRC32=m
 # CONFIG_CRC7 is not set
 # CONFIG_LIBCRC32C is not set
 CONFIG_PLIST=y
-CONFIG_HAS_DMA=y
 
 #
 # SCSI device support
diff --git a/arch/um/include/asm/dma-mapping.h b/arch/um/include/asm/dma-mapping.h
deleted file mode 100644
index 1f469e8..0000000
--- a/arch/um/include/asm/dma-mapping.h
+++ /dev/null
@@ -1,112 +0,0 @@
-#ifndef _ASM_DMA_MAPPING_H
-#define _ASM_DMA_MAPPING_H
-
-#include <asm/scatterlist.h>
-
-static inline int
-dma_supported(struct device *dev, u64 mask)
-{
-	BUG();
-	return(0);
-}
-
-static inline int
-dma_set_mask(struct device *dev, u64 dma_mask)
-{
-	BUG();
-	return(0);
-}
-
-static inline void *
-dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
-		   gfp_t flag)
-{
-	BUG();
-	return((void *) 0);
-}
-
-static inline void
-dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
-		  dma_addr_t dma_handle)
-{
-	BUG();
-}
-
-static inline dma_addr_t
-dma_map_single(struct device *dev, void *cpu_addr, size_t size,
-	       enum dma_data_direction direction)
-{
-	BUG();
-	return(0);
-}
-
-static inline void
-dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
-		 enum dma_data_direction direction)
-{
-	BUG();
-}
-
-static inline dma_addr_t
-dma_map_page(struct device *dev, struct page *page,
-	     unsigned long offset, size_t size,
-	     enum dma_data_direction direction)
-{
-	BUG();
-	return(0);
-}
-
-static inline void
-dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
-	       enum dma_data_direction direction)
-{
-	BUG();
-}
-
-static inline int
-dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
-	   enum dma_data_direction direction)
-{
-	BUG();
-	return(0);
-}
-
-static inline void
-dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
-	     enum dma_data_direction direction)
-{
-	BUG();
-}
-
-static inline void
-dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size,
-		enum dma_data_direction direction)
-{
-	BUG();
-}
-
-static inline void
-dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
-	    enum dma_data_direction direction)
-{
-	BUG();
-}
-
-#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
-#define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
-
-static inline void
-dma_cache_sync(struct device *dev, void *vaddr, size_t size,
-	       enum dma_data_direction direction)
-{
-	BUG();
-}
-
-static inline int
-dma_mapping_error(struct device *dev, dma_addr_t dma_handle)
-{
-	BUG();
-	return 0;
-}
-
-#endif
-- 
1.7.1