Introduce CONFIG_HAS_DMA

Architectures that don't support DMA can say so by adding a config NO_DMA
to their Kconfig file.  This will prevent compilation of some dma specific
driver code.  Also dma-mapping-broken.h isn't needed anymore on at least
s390.  This avoids compilation and linking of otherwise dead/broken code.

Other architectures that include dma-mapping-broken.h are arm26, h8300,
m68k, m68knommu and v850.  If these could be converted as well we could get
rid of the header file.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
"John W. Linville" <linville@tuxdriver.com>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: <James.Bottomley@SteelEye.com>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <geert@linux-m68k.org>
Cc: <zippel@linux-m68k.org>
Cc: <spyro@f2s.com>
Cc: <uclinux-v850@lsi.nec.co.jp>
Cc: <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/s390/Kconfig

@@ -49,6 +49,9 @@ config GENERIC_BUG
 config NO_IOMEM
 	def_bool y
 
+config NO_DMA
+	def_bool y
+
 mainmenu "Linux Kernel Configuration"
 
 config S390

drivers/base/Makefile

@@ -2,10 +2,10 @@
 
 obj-y			:= core.o sys.o bus.o dd.o \
 			   driver.o class.o platform.o \
-			   cpu.o firmware.o init.o map.o dmapool.o \
-			   dma-mapping.o devres.o \
+			   cpu.o firmware.o init.o map.o devres.o \
 			   attribute_container.o transport_class.o
 obj-y			+= power/
+obj-$(CONFIG_HAS_DMA)	+= dma-mapping.o dmapool.o
 obj-$(CONFIG_ISA)	+= isa.o
 obj-$(CONFIG_FW_LOADER)	+= firmware_class.o
 obj-$(CONFIG_NUMA)	+= node.o

include/asm-s390/dma-mapping.h

@@ -9,6 +9,4 @@
 #ifndef _ASM_DMA_MAPPING_H
 #define _ASM_DMA_MAPPING_H
 
-#include <asm-generic/dma-mapping-broken.h>
-
 #endif /* _ASM_DMA_MAPPING_H */

lib/Kconfig

@@ -111,4 +111,9 @@ config HAS_IOPORT
 	depends on HAS_IOMEM && !NO_IOPORT
 	default y
 
+config HAS_DMA
+	boolean
+	depends on !NO_DMA
+	default y
+
 endmenu