[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>

diff --git a/arch/powerpc/kernel/cpu_setup_power4.S b/arch/powerpc/kernel/cpu_setup_power4.S
index 2714183..1fc8632 100644 (file)
--- 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) */