powerpc: Setup relocation on exceptions for bare metal systems

This turns on MMU on execptions via AIL field in the LPCR.

Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 4 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 7b44a6e3e0f0..1b853f744f8b 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -249,6 +249,8 @@
 #define   LPCR_RMLS    0x1C000000      /* impl dependent rmo limit sel */
 #define   LPCR_RMLS_SH  (63-37)
 #define   LPCR_ILE     0x02000000      /* !HV irqs set MSR:LE */
+#define   LPCR_AIL_0    0x00000000      /* MMU off exception offset 0x0 */
+#define   LPCR_AIL_3    0x01800000      /* MMU on exception offset 0xc00...4xxx */
 #define   LPCR_PECE     0x00007000      /* powersave exit cause enable */
 #define     LPCR_PECE0  0x00004000      /* ext. exceptions can cause exit */
 #define     LPCR_PECE1  0x00002000      /* decrementer can cause exit */
diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S
index 52dd03396c5d..57cf14065aec 100644
--- a/arch/powerpc/kernel/cpu_setup_power.S
+++ b/arch/powerpc/kernel/cpu_setup_power.S
@@ -54,6 +54,7 @@ _GLOBAL(__setup_cpu_power8)
         li      r0,0
         mtspr   SPRN_LPID,r0
         mfspr   r3,SPRN_LPCR
+        oris    r3, r3, LPCR_AIL_3@h
         bl      __init_LPCR
         bl      __init_TLB
         mtlr    r11
@@ -67,6 +68,7 @@ _GLOBAL(__restore_cpu_power8)
         li      r0,0
         mtspr   SPRN_LPID,r0
         mfspr   r3,SPRN_LPCR
+        oris    r3, r3, LPCR_AIL_3@h
         bl      __init_LPCR
         bl      __init_TLB
         mtlr    r11