powerpc: Fix for getting CPU number in power_save_ppc32_restore()

The calculation to get TI_CPU based off of SPRG3 was just plain wrong,
meaning that we were getting garbage for the CPU number on 6xx/G3/G4
based SMP boxes in this code.

Just offset off the stack pointer (to get to thread_info) like all the
other references to TI_CPU do.

This was pointed out by Chen Gong <G.Chen@freescale.com>

[paulus@samba.org - use rlwinm r12,r11,... instead of
 rlwinm r12,r1,...; tophys()]

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

2 files changed, 3 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/idle_6xx.S b/arch/powerpc/kernel/idle_6xx.S
index 019b02d8844f..15c611de1ee2 100644
--- a/arch/powerpc/kernel/idle_6xx.S
+++ b/arch/powerpc/kernel/idle_6xx.S
@@ -158,7 +158,7 @@ _GLOBAL(power_save_ppc32_restore)
         stw     r9,_NIP(r11)            /* make it do a blr */
 
 #ifdef CONFIG_SMP
-        mfspr   r12,SPRN_SPRG3
+        rlwinm  r12,r11,0,0,31-THREAD_SHIFT
         lwz     r11,TI_CPU(r12)         /* get cpu number * 4 */
         slwi    r11,r11,2
 #else
diff --git a/arch/powerpc/kernel/idle_e500.S b/arch/powerpc/kernel/idle_e500.S
index 06304034b393..47a1a983ff88 100644
--- a/arch/powerpc/kernel/idle_e500.S
+++ b/arch/powerpc/kernel/idle_e500.S
@@ -84,10 +84,11 @@ _GLOBAL(power_save_ppc32_restore)
         stw     r9,_NIP(r11)            /* make it do a blr */
 
 #ifdef CONFIG_SMP
-        mfspr   r12,SPRN_SPRG3
+        rlwinm  r12,r1,0,0,31-THREAD_SHIFT
         lwz     r11,TI_CPU(r12)         /* get cpu number * 4 */
         slwi    r11,r11,2
 #else
         li      r11,0
 #endif
+
         b       transfer_to_handler_cont