powerpc: Move some extern declarations from C code into headers

This also make klimit have the same type on 32-bit as on 64-bit,
namely unsigned long, and defines and initializes it in one place.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/system.h b/include/asm-powerpc/system.h
index f0cce5a..5341b75 100644
--- a/include/asm-powerpc/system.h
+++ b/include/asm-powerpc/system.h
@@ -179,6 +179,7 @@
 extern unsigned int rtas_data;
 extern int mem_init_done;	/* set on boot once kmalloc can be called */
 extern unsigned long memory_limit;
+extern unsigned long klimit;
 
 extern int powersave_nap;	/* set if nap mode can be used in idle loop */
 
diff --git a/include/asm-ppc64/mmu.h b/include/asm-ppc64/mmu.h
index c43d512..1a7e0af 100644
--- a/include/asm-ppc64/mmu.h
+++ b/include/asm-ppc64/mmu.h
@@ -229,6 +229,7 @@
 extern void hpte_init_native(void);
 extern void hpte_init_lpar(void);
 extern void hpte_init_iSeries(void);
+extern void mm_init_ppc64(void);
 
 extern long pSeries_lpar_hpte_insert(unsigned long hpte_group,
 				     unsigned long va, unsigned long prpn,