[POWERPC] 4xx: Fix 4xx flush_tlb_page()

On 4xx CPUs, the current implementation of flush_tlb_page() uses
a low level _tlbie() assembly function that only works for the
current PID. Thus, invalidations caused by, for example, a COW
fault triggered by get_user_pages() from a different context will
not work properly, causing among other things, gdb breakpoints
to fail.

This patch adds a "pid" argument to _tlbie() on 4xx processors,
and uses it to flush entries in the right context. FSL BookE
also gets the argument but it seems they don't need it (their
tlbivax form ignores the PID when invalidating according to the
document I have).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
diff --git a/include/asm-powerpc/tlbflush.h b/include/asm-powerpc/tlbflush.h
index b6b036c..e7b4c0d 100644
--- a/include/asm-powerpc/tlbflush.h
+++ b/include/asm-powerpc/tlbflush.h
@@ -1,5 +1,6 @@
 #ifndef _ASM_POWERPC_TLBFLUSH_H
 #define _ASM_POWERPC_TLBFLUSH_H
+
 /*
  * TLB flushing:
  *
@@ -16,9 +17,6 @@
  */
 #ifdef __KERNEL__
 
-struct mm_struct;
-struct vm_area_struct;
-
 #if defined(CONFIG_4xx) || defined(CONFIG_8xx) || defined(CONFIG_FSL_BOOKE)
 /*
  * TLB flushing for software loaded TLB chips
@@ -28,7 +26,9 @@
  * specific tlbie's
  */
 
-extern void _tlbie(unsigned long address);
+#include <linux/mm.h>
+
+extern void _tlbie(unsigned long address, unsigned int pid);
 
 #if defined(CONFIG_40x) || defined(CONFIG_8xx)
 #define _tlbia()	asm volatile ("tlbia; sync" : : : "memory")
@@ -44,13 +44,13 @@
 static inline void flush_tlb_page(struct vm_area_struct *vma,
 				  unsigned long vmaddr)
 {
-	_tlbie(vmaddr);
+	_tlbie(vmaddr, vma->vm_mm->context.id);
 }
 
 static inline void flush_tlb_page_nohash(struct vm_area_struct *vma,
 					 unsigned long vmaddr)
 {
-	_tlbie(vmaddr);
+	_tlbie(vmaddr, vma->vm_mm->context.id);
 }
 
 static inline void flush_tlb_range(struct vm_area_struct *vma,