[POWERPC] Don't access HID registers if running on a Hypervisor.

The following patch avoids accessing Hypervisor privilege HID
registers when running on a Hypervisor (MSR[HV]=0).

Signed-off-by: Jimi Xenidis <jimix@watson.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 12 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/cpu_setup_power4.S b/arch/powerpc/kernel/cpu_setup_power4.S
index 271418308d53..1fc863261003 100644
--- a/arch/powerpc/kernel/cpu_setup_power4.S
+++ b/arch/powerpc/kernel/cpu_setup_power4.S
@@ -125,7 +125,12 @@ _GLOBAL(__save_cpu_setup)
         cmpwi   r0,0x44
         bne     2f
 
-1:      /* Save HID0,1,4 and 5 */
+1:      /* skip if not running in HV mode */
+        mfmsr   r0
+        rldicl. r0,r0,4,63
+        beq     2f
+
+        /* Save HID0,1,4 and 5 */
         mfspr   r3,SPRN_HID0
         std     r3,CS_HID0(r5)
         mfspr   r3,SPRN_HID1
@@ -159,7 +164,12 @@ _GLOBAL(__restore_cpu_setup)
         cmpwi   r0,0x44
         bnelr
 
-1:      /* Before accessing memory, we make sure rm_ci is clear */
+1:      /* skip if not running in HV mode */
+        mfmsr   r0
+        rldicl. r0,r0,4,63
+        beqlr
+
+        /* Before accessing memory, we make sure rm_ci is clear */
         li      r0,0
         mfspr   r3,SPRN_HID4
         rldimi  r3,r0,40,23     /* clear bit 23 (rm_ci) */