From: Mahesh Salgaonkar <mahesh@xxxxxxxxxxxxxxxxxx> OPAL_CALL wrapper code sticks the r1 (stack pointer) into PACAR1 purely for debugging purpose only. The power7_wakeup* functions relies on stack pointer saved in PACAR1. Any opal call made using opal wrapper (directly or in-directly) before we fall through power7_wakeup*, then it ends up replacing r1 in PACAR1(r13) leading to kernel panic. So far we don't see any issues because we have never made any opal calls using OPAL wrapper before power7_wakeup*. But the subsequent HMI patch would need to invoke C calls during cpu wakeup/idle path that in-directly makes opal call using opal wrapper. This patch facilitates the subsequent HMI patch by removing usage of PACAR1 from opal call wrapper. Signed-off-by: Mahesh Salgaonkar <mahesh@xxxxxxxxxxxxxxxxxx> Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> --- arch/powerpc/platforms/powernv/opal-wrappers.S | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S index e45b88a..df6ad94 100644 --- a/arch/powerpc/platforms/powernv/opal-wrappers.S +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S @@ -64,7 +64,6 @@ END_FTR_SECTION(0, 1); \ OPAL_BRANCH(opal_tracepoint_entry) \ mfcr r12; \ stw r12,8(r1); \ - std r1,PACAR1(r13); \ li r11,0; \ mfmsr r12; \ ori r11,r11,MSR_EE; \ @@ -127,7 +126,6 @@ opal_tracepoint_entry: mfcr r12 std r11,16(r1) stw r12,8(r1) - std r1,PACAR1(r13) li r11,0 mfmsr r12 ori r11,r11,MSR_EE -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
