powerpc: Add _GLOBAL_TOC for ABIv2 assembly functions exported to modules

If an assembly function that calls back into c code is exported to
modules, we need to ensure r2 is setup correctly. There are only
two places crazy enough to do it (two of which are my fault).
Signed-off-by: Anton Blanchard <anton@samba.org>

arch/powerpc/include/asm/ppc_asm.h

@@ -207,6 +207,16 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
 	.globl name; \
 name:
 
+#define _GLOBAL_TOC(name) \
+	.section ".text"; \
+	.align 2 ; \
+	.type name,@function; \
+	.globl name; \
+name: \
+0:	addis r2,r12,(.TOC.-0b)@ha; \
+	addi r2,r2,(.TOC.-0b)@l; \
+	.localentry name,.-name
+
 #define _KPROBE(name) \
 	.section ".kprobes.text","a"; \
 	.align 2 ; \
@@ -235,6 +245,8 @@ name: \
 	.type GLUE(.,name),@function; \
 GLUE(.,name):
 
+#define _GLOBAL_TOC(name) _GLOBAL(name)
+
 #define _KPROBE(name) \
 	.section ".kprobes.text","a"; \
 	.align 2 ; \

arch/powerpc/lib/copyuser_64.S

@@ -18,7 +18,7 @@
 #endif
 
 	.align	7
-_GLOBAL(__copy_tofrom_user)
+_GLOBAL_TOC(__copy_tofrom_user)
 BEGIN_FTR_SECTION
 	nop
 FTR_SECTION_ELSE

arch/powerpc/lib/memcpy_64.S

@@ -10,7 +10,7 @@
 #include <asm/ppc_asm.h>
 
 	.align	7
-_GLOBAL(memcpy)
+_GLOBAL_TOC(memcpy)
 BEGIN_FTR_SECTION
 	std	r3,-STACKFRAMESIZE+STK_REG(R31)(r1)	/* save destination pointer for return value */
 FTR_SECTION_ELSE