dma-mapping: prevent dma dependent code from linking on !HAS_DMA archs

Continuing the work started in 411f0f3edc141a582190d3605cadd1d993abb6df ...

This enables code with a dma path, that compiles away, to build without
requiring additional code factoring. It also prevents code that calls
dma_alloc_coherent and dma_free_coherent from linking whereas previously
the code would hit a BUG() at run time. Finally, it allows archs that set
!HAS_DMA to delete their asm/dma-mapping.h file.

Cc: Cornelia Huck <[e-mail]>
Cc: Martin Schwidefsky <[e-mail]>
Cc: Heiko Carstens <[e-mail]>
Cc: John W. Linville <[e-mail]>
Cc: Kyle McMartin <[e-mail]>
Cc: James Bottomley <[e-mail]>
Cc: Tejun Heo <[e-mail]>
Cc: Jeff Garzik <[e-mail]>
Cc: <[e-mail]>
Cc: <[e-mail]>
Cc: <[e-mail]>
Cc: <[e-mail]>
Signed-off-by: Dan Williams <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/arm26/Kconfig

···
 	bool
 	default y
 
+config NO_DMA
+	def_bool y
+
 config ARCH_ACORN
         bool
         default y

arch/h8300/Kconfig

···
 config NO_IOPORT
 	def_bool y
 
+config NO_DMA
+	def_bool y
+
 config ISA
 	bool
 	default y

arch/m32r/Kconfig

···
 config NO_IOPORT
 	def_bool y
 
+config NO_DMA
+	def_bool y
+
 source "init/Kconfig"
 
 

drivers/dma/Kconfig

···
 #
 
 menu "DMA Engine support"
-	depends on !S390
+	depends on HAS_DMA
 
 config DMA_ENGINE
 	bool "Support for DMA engines"

include/asm-arm26/dma-mapping.h

···
-#include <asm-generic/dma-mapping-broken.h>
-

include/asm-generic/dma-mapping-broken.h

···
 #ifndef _ASM_GENERIC_DMA_MAPPING_H
 #define _ASM_GENERIC_DMA_MAPPING_H
 
-/* This is used for archs that do not support DMA */
+/* define the dma api to allow compilation but not linking of
+ * dma dependent code.  Code that depends on the dma-mapping
+ * API needs to set 'depends on HAS_DMA' in its Kconfig
+ */
 
-static inline void *
+struct scatterlist;
+
+extern void *
 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
-		   gfp_t flag)
-{
-	BUG();
-	return NULL;
-}
+		   gfp_t flag);
 
-static inline void
+extern void
 dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
-		    dma_addr_t dma_handle)
-{
-	BUG();
-}
+		    dma_addr_t dma_handle);
 
 #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)
+
+extern dma_addr_t
+dma_map_single(struct device *dev, void *ptr, size_t size,
+	       enum dma_data_direction direction);
+
+extern void
+dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
+		 enum dma_data_direction direction);
+
+extern int
+dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+	   enum dma_data_direction direction);
+
+extern void
+dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
+	     enum dma_data_direction direction);
+
+extern dma_addr_t
+dma_map_page(struct device *dev, struct page *page, unsigned long offset,
+	     size_t size, enum dma_data_direction direction);
+
+extern void
+dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
+	       enum dma_data_direction direction);
+
+extern void
+dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size,
+			enum dma_data_direction direction);
+
+extern void
+dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
+			      unsigned long offset, size_t size,
+			      enum dma_data_direction direction);
+
+extern void
+dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
+		    enum dma_data_direction direction);
+
+#define dma_sync_single_for_device dma_sync_single_for_cpu
+#define dma_sync_single_range_for_device dma_sync_single_range_for_cpu
+#define dma_sync_sg_for_device dma_sync_sg_for_cpu
+
+extern int
+dma_mapping_error(dma_addr_t dma_addr);
+
+extern int
+dma_supported(struct device *dev, u64 mask);
+
+extern int
+dma_set_mask(struct device *dev, u64 mask);
+
+extern int
+dma_get_cache_alignment(void);
+
+extern int
+dma_is_consistent(struct device *dev, dma_addr_t dma_handle);
+
+extern void
+dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+	       enum dma_data_direction direction);
 
 #endif /* _ASM_GENERIC_DMA_MAPPING_H */

include/asm-h8300/dma-mapping.h

···
-#include <asm-generic/dma-mapping-broken.h>

include/asm-m32r/dma-mapping.h

···
-#ifndef _ASM_M32R_DMA_MAPPING_H
-#define _ASM_M32R_DMA_MAPPING_H
-
-#include <asm-generic/dma-mapping-broken.h>
-
-#endif /* _ASM_M32R_DMA_MAPPING_H */

include/asm-s390/dma-mapping.h

···
-/*
- *  include/asm-s390/dma-mapping.h
- *
- *  S390 version
- *
- *  This file exists so that #include <dma-mapping.h> doesn't break anything.
- */
-
-#ifndef _ASM_DMA_MAPPING_H
-#define _ASM_DMA_MAPPING_H
-
-#endif /* _ASM_DMA_MAPPING_H */

include/linux/dma-mapping.h

···
 		(dma_direction == DMA_FROM_DEVICE));
 }
 
+#ifdef CONFIG_HAS_DMA
 #include <asm/dma-mapping.h>
+#else
+#include <asm-generic/dma-mapping-broken.h>
+#endif
 
 /* Backwards compat, remove in 2.7.x */
 #define dma_sync_single		dma_sync_single_for_cpu