[POWERPC] Add __read_mostly support for powerpc

Signed-off-by: NTony Breeds <tony@bakeyournoodle.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

arch/powerpc/kernel/vmlinux.lds.S

@@ -7,6 +7,7 @@
 #define PROVIDE32(x)	PROVIDE(x)
 #endif
 #include <asm-generic/vmlinux.lds.h>
+#include <asm/cache.h>
 
 ENTRY(_stext)
 
@@ -211,6 +212,11 @@ SECTIONS
 		*(.data.cacheline_aligned)
 	}
 
+	. = ALIGN(L1_CACHE_BYTES);
+	.data.read_mostly : {
+		*(.data.read_mostly)
+	}
+
 	. = ALIGN(PAGE_SIZE);
 	__data_nosave : {
 		__nosave_begin = .;

include/asm-powerpc/cache.h

@@ -34,5 +34,9 @@ struct ppc64_caches {
 extern struct ppc64_caches ppc64_caches;
 #endif /* __powerpc64__ && ! __ASSEMBLY__ */
 
+#if !defined(__ASSEMBLY__)
+#define __read_mostly __attribute__((__section__(".data.read_mostly")))
+#endif
+
 #endif /* __KERNEL__ */
 #endif /* _ASM_POWERPC_CACHE_H */