1 files changed, 11 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 0c326823c6d4..be9f9e5470e8 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -31,6 +31,7 @@
 #include <asm/ppc_asm.h>
 #include <asm/asm-offsets.h>
 #include <asm/ptrace.h>
+#include <asm/bug.h>
 
 /* 601 only have IBAT; cr0.eq is set on 601 when using this macro */
 #define LOAD_BAT(n, reg, RA, RB)        \
@@ -1070,9 +1071,14 @@ start_here:
         RFI
 
 /*
+ * void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
+ *
  * Set up the segment registers for a new context.
  */
-_ENTRY(set_context)
+_ENTRY(switch_mmu_context)
+        lwz     r3,MMCONTEXTID(r4)
+        cmpwi   cr0,r3,0
+        blt-    4f
         mulli   r3,r3,897       /* multiply context by skew factor */
         rlwinm  r3,r3,4,8,27    /* VSID = (context & 0xfffff) << 4 */
         addis   r3,r3,0x6000    /* Set Ks, Ku bits */
@@ -1083,6 +1089,7 @@ _ENTRY(set_context)
         /* Context switch the PTE pointer for the Abatron BDI2000.
          * The PGDIR is passed as second argument.
          */
+        lwz     r4,MM_PGD(r4)
         lis     r5, KERNELBASE@h
         lwz     r5, 0xf0(r5)
         stw     r4, 0x4(r5)
@@ -1098,6 +1105,9 @@ _ENTRY(set_context)
         sync
         isync
         blr
+4:      trap
+        EMIT_BUG_ENTRY 4b,__FILE__,__LINE__,0
+        blr
 
 /*
  * An undocumented "feature" of 604e requires that the v bit