MIPS: Octeon: Fix build error if CONFIG_BUG=n

  CC      init/do_mounts.o
In file included from /home/ralf/src/linux/linux-mips/arch/mips/include/asm/dma-mapping.h:10:0,
                 from include/linux/dma-mapping.h:76,
                 from include/linux/skbuff.h:33,
                 from include/linux/icmpv6.h:4,
                 from include/linux/ipv6.h:59,
                 from include/net/ipv6.h:16,
                 from include/linux/sunrpc/clnt.h:26,
                 from include/linux/nfs_fs.h:30,
                 from init/do_mounts.c:30:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_map_dma_mem’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:24:1: warning: no return statement in function returning non-void [-Wreturn-type]
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_map_dma_mem_page’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:30:1: warning: no return statement in function returning non-void [-Wreturn-type]
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_dma_addr_to_phys’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:36:1: warning: no return statement in function returning non-void [-Wreturn-type]
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_dma_supported’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:47:1: warning: no return statement in function returning non-void [-Wreturn-type]
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_dma_mapping_error’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:63:1: warning: no return statement in function returning non-void [-Wreturn-type]
  LD      init/mounts.o
  CC      init/init_task.o
In file included from /home/ralf/src/linux/linux-mips/arch/mips/include/asm/dma-mapping.h:10:0,
                 from include/linux/dma-mapping.h:76,
                 from include/linux/skbuff.h:33,
                 from include/linux/netfilter.h:5,
                 from include/net/netns/netfilter.h:5,
                 from include/net/net_namespace.h:20,
                 from include/linux/init_task.h:14,
                 from init/init_task.c:1:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_map_dma_mem’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:24:1: warning: no return statement in function returning non-void [-Wreturn-type]
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_map_dma_mem_page’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:30:1: warning: no return statement in function returning non-void [-Wreturn-type]
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_dma_addr_to_phys’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:36:1: warning: no return statement in function returning non-void [-Wreturn-type]
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_dma_supported’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:47:1: warning: no return statement in function returning non-void [-Wreturn-type]
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_dma_mapping_error’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:63:1: warning: no return statement in function returning non-void [-Wreturn-type]
  LD      init/built-in.o
  CC      arch/mips/cavium-octeon/setup.o
In file included from /home/ralf/src/linux/linux-mips/arch/mips/include/asm/dma-mapping.h:10:0,
                 from include/linux/dma-mapping.h:76,
                 from include/asm-generic/pci-dma-compat.h:7,
                 from /home/ralf/src/linux/linux-mips/arch/mips/include/asm/pci.h:129,
                 from include/linux/pci.h:1451,
                 from /home/ralf/src/linux/linux-mips/arch/mips/include/asm/octeon/pci-octeon.h:12,
                 from arch/mips/cavium-octeon/setup.c:41:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_map_dma_mem’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:24:1: error: no return statement in function returning non-void [-Werror=return-type]
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_map_dma_mem_page’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:30:1: error: no return statement in function returning non-void [-Werror=return-type]
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_dma_addr_to_phys’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:36:1: error: no return statement in function returning non-void [-Werror=return-type]
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_dma_supported’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:47:1: error: no return statement in function returning non-void [-Werror=return-type]
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h: In function ‘plat_dma_mapping_error’:
/home/ralf/src/linux/linux-mips/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h:63:1: error: no return statement in function returning non-void [-Werror=return-type]
cc1: all warnings being treated as errors
make[2]: *** [arch/mips/cavium-octeon/setup.o] Error 1
make[1]: *** [arch/mips/cavium-octeon] Error 2
make: *** [arch/mips] Error 2

[ralf@linux-mips.org: while at it, also include <linux/bug.h> directly.]
Signed-off-by: David Daney <david.daney@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/5519/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h

@@ -13,6 +13,8 @@
 #ifndef __ASM_MACH_CAVIUM_OCTEON_DMA_COHERENCE_H
 #define __ASM_MACH_CAVIUM_OCTEON_DMA_COHERENCE_H
 
+#include <linux/bug.h>
+
 struct device;
 
 extern void octeon_pci_dma_init(void);
@@ -21,18 +23,21 @@ static inline dma_addr_t plat_map_dma_mem(struct device *dev, void *addr,
 	size_t size)
 {
 	BUG();
+	return 0;
 }
 
 static inline dma_addr_t plat_map_dma_mem_page(struct device *dev,
 	struct page *page)
 {
 	BUG();
+	return 0;
 }
 
 static inline unsigned long plat_dma_addr_to_phys(struct device *dev,
 	dma_addr_t dma_addr)
 {
 	BUG();
+	return 0;
 }
 
 static inline void plat_unmap_dma_mem(struct device *dev, dma_addr_t dma_addr,
@@ -44,6 +49,7 @@ static inline void plat_unmap_dma_mem(struct device *dev, dma_addr_t dma_addr,
 static inline int plat_dma_supported(struct device *dev, u64 mask)
 {
 	BUG();
+	return 0;
 }
 
 static inline void plat_extra_sync_for_device(struct device *dev)
@@ -60,6 +66,7 @@ static inline int plat_dma_mapping_error(struct device *dev,
 					 dma_addr_t dma_addr)
 {
 	BUG();
+	return 0;
 }
 
 dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);