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 <cornelia.huck@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: <geert@linux-m68k.org>
Cc: <zippel@linux-m68k.org>
Cc: <spyro@f2s.com>
Cc: <ysato@users.sourceforge.jp>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

10 files changed, 84 insertions, 34 deletions

diff --git a/arch/arm26/Kconfig b/arch/arm26/Kconfig
index 20688bc13e9b..9044f33299f7 100644
--- a/arch/arm26/Kconfig
+++ b/arch/arm26/Kconfig
@@ -17,6 +17,9 @@ config MMU
         bool
         default y
 
+config NO_DMA
+        def_bool y
+
 config ARCH_ACORN
         bool
         default y
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index 618dbad696f6..e35f74e6e505 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -68,6 +68,9 @@ config TIME_LOW_RES
 config NO_IOPORT
         def_bool y
 
+config NO_DMA
+        def_bool y
+
 config ISA
         bool
         default y
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index c3bb8a755b00..8ccf3e47bff8 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -31,6 +31,9 @@ config GENERIC_IRQ_PROBE
 config NO_IOPORT
         def_bool y
 
+config NO_DMA
+        def_bool y
+
 source "init/Kconfig"
 
 
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index b31756d59978..8f670dae53bb 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -3,7 +3,7 @@
 #
 
 menu "DMA Engine support"
-        depends on !S390
+        depends on HAS_DMA
 
 config DMA_ENGINE
         bool "Support for DMA engines"
diff --git a/include/asm-arm26/dma-mapping.h b/include/asm-arm26/dma-mapping.h
deleted file mode 100644
index a95eae0aeb77..000000000000
--- a/include/asm-arm26/dma-mapping.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#include <asm-generic/dma-mapping-broken.h>
-
diff --git a/include/asm-generic/dma-mapping-broken.h b/include/asm-generic/dma-mapping-broken.h
index 29413d3d4605..e2468f894d2a 100644
--- a/include/asm-generic/dma-mapping-broken.h
+++ b/include/asm-generic/dma-mapping-broken.h
@@ -1,24 +1,82 @@
 #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 */
diff --git a/include/asm-h8300/dma-mapping.h b/include/asm-h8300/dma-mapping.h
deleted file mode 100644
index d00e40099165..000000000000
--- a/include/asm-h8300/dma-mapping.h
+++ /dev/null
@@ -1 +0,0 @@
-#include <asm-generic/dma-mapping-broken.h>
diff --git a/include/asm-m32r/dma-mapping.h b/include/asm-m32r/dma-mapping.h
deleted file mode 100644
index f9b58ebba361..000000000000
--- a/include/asm-m32r/dma-mapping.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#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 */
diff --git a/include/asm-s390/dma-mapping.h b/include/asm-s390/dma-mapping.h
deleted file mode 100644
index 3f8c12fde0f0..000000000000
--- a/include/asm-s390/dma-mapping.h
+++ /dev/null
@@ -1,12 +0,0 @@
-/*
- *  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 */
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 9a663c6db16a..2dc21cbeb304 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -31,7 +31,11 @@ static inline int valid_dma_direction(int dma_direction)
                 (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