powerpc: Fix TLB cleanup at boot on POWER8

The TLB has 512 congruence classes (2048 entries 4 way set associative)
while P7 had 128

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S
index a283b6442b26..18b5b9cf8e37 100644
--- a/arch/powerpc/kernel/cpu_setup_power.S
+++ b/arch/powerpc/kernel/cpu_setup_power.S
@@ -135,8 +135,12 @@ __init_HFSCR:
         blr
 
 __init_TLB:
-        /* Clear the TLB */
-        li      r6,128
+        /*
+         * Clear the TLB using the "IS 3" form of tlbiel instruction
+         * (invalidate by congruence class). P7 has 128 CCs, P8 has 512
+         * so we just always do 512
+         */
+        li      r6,512
         mtctr   r6
         li      r7,0xc00        /* IS field = 0b11 */
         ptesync