From cb0be7ec03077a31712183bfbe7801061e2966b8 Mon Sep 17 00:00:00 2001
From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
Date: Tue, 16 May 2017 14:19:45 +0530
Subject: [PATCH] powerpc/powernv/idle: Restore LPCR on wakeup from deep-stop
References: bsc#1055121
Patch-mainline: v4.13-rc1
Git-commit: cb0be7ec03077a31712183bfbe7801061e2966b8
On wakeup from a deep stop state which is supposed to lose the
hypervisor state, we don't restore the LPCR to the old value but set
it to a "sane" value via cur_cpu_spec->cpu_restore().
The problem is that the "sane" value doesn't include UPRT and the HR
bits which are required to run correctly in Radix mode.
Fix this on POWER9 onwards by restoring the LPCR value whatever it was
before executing the stop instruction.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/kernel/idle_book3s.S | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index afd029f1039b..6c9920d9221c 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -31,6 +31,7 @@
* registers for winkle support.
*/
#define _SDR1 GPR3
+#define _PTCR GPR3
#define _RPR GPR4
#define _SPURR GPR5
#define _PURR GPR6
@@ -39,7 +40,7 @@
#define _AMOR GPR9
#define _WORT GPR10
#define _WORC GPR11
-#define _PTCR GPR12
+#define _LPCR GPR12
#define PSSCR_EC_ESL_MASK_SHIFTED (PSSCR_EC | PSSCR_ESL) >> 16
@@ -55,12 +56,14 @@ save_sprs_to_stack:
* here since any thread in the core might wake up first
*/
BEGIN_FTR_SECTION
- mfspr r3,SPRN_PTCR
- std r3,_PTCR(r1)
/*
* Note - SDR1 is dropped in Power ISA v3. Hence not restoring
* SDR1 here
*/
+ mfspr r3,SPRN_PTCR
+ std r3,_PTCR(r1)
+ mfspr r3,SPRN_LPCR
+ std r3,_LPCR(r1)
FTR_SECTION_ELSE
mfspr r3,SPRN_SDR1
std r3,_SDR1(r1)
@@ -813,6 +816,10 @@ no_segments:
mtctr r12
bctrl
+BEGIN_FTR_SECTION
+ ld r4,_LPCR(r1)
+ mtspr SPRN_LPCR,r4
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
hypervisor_state_restored:
mtspr SPRN_SRR1,r16
--
2.10.2