powerpc/64s: Fix OPAL_CALL non-maskable interrupt reentrancy

OPAL_CALL uses SRR[01] with MSR_RI=1, which gets corrupted if there
is an interleaving system reset or machine check interrupt.

Use HSRR[01] instead, which does not require MSR_RI=0.

Signed-off-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>

diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index f620572f891f4ffdde6702f400158383bba5dd59..4ca6c26a56d5cd2c2ef5fcbe0fda2c034b9dae3d 100644 (file)
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -99,10 +99,10 @@ opal_return:
        lwz     r4,8(r1);
        ld      r5,PPC_LR_STKOFF(r1);
        ld      r6,PACASAVEDMSR(r13);
-       mtspr   SPRN_SRR0,r5;
-       mtspr   SPRN_SRR1,r6;
        mtcr    r4;
-       rfid
+       mtspr   SPRN_HSRR0,r5;
+       mtspr   SPRN_HSRR1,r6;
+       hrfid
 
 opal_real_call:
        mfcr    r11