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authorIngo Molnar <mingo@kernel.org>2017-08-10 13:14:15 +0200
committerIngo Molnar <mingo@kernel.org>2017-08-10 13:14:15 +0200
commit1d0f49e14007a5426eb7e9e5808168cdb77b3e7f (patch)
tree1d7eb036e06938dedb7488910e4d34dc4c73fa68 /arch/powerpc/kernel/idle_book3s.S
parent99504819fc643160afd6813921b1d42b18e52a49 (diff)
parente93c17301ac55321fc18e0f8316e924e58a83c8c (diff)
downloadlinux-stable-1d0f49e14007a5426eb7e9e5808168cdb77b3e7f.tar.gz
Merge branch 'x86/urgent' into x86/asm, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/powerpc/kernel/idle_book3s.S')
-rw-r--r--arch/powerpc/kernel/idle_book3s.S21
1 files changed, 20 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index 5adb390e773b..e6252c5a57a4 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -30,6 +30,7 @@
* Use unused space in the interrupt stack to save and restore
* registers for winkle support.
*/
+#define _MMCR0 GPR0
#define _SDR1 GPR3
#define _PTCR GPR3
#define _RPR GPR4
@@ -272,6 +273,14 @@ power_enter_stop:
b pnv_wakeup_noloss
.Lhandle_esl_ec_set:
+ /*
+ * POWER9 DD2 can incorrectly set PMAO when waking up after a
+ * state-loss idle. Saving and restoring MMCR0 over idle is a
+ * workaround.
+ */
+ mfspr r4,SPRN_MMCR0
+ std r4,_MMCR0(r1)
+
/*
* Check if the requested state is a deep idle state.
*/
@@ -450,10 +459,20 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
pnv_restore_hyp_resource_arch300:
/*
* Workaround for POWER9, if we lost resources, the ERAT
- * might have been mixed up and needs flushing.
+ * might have been mixed up and needs flushing. We also need
+ * to reload MMCR0 (see comment above). We also need to set
+ * then clear bit 60 in MMCRA to ensure the PMU starts running.
*/
blt cr3,1f
PPC_INVALIDATE_ERAT
+ ld r1,PACAR1(r13)
+ mfspr r4,SPRN_MMCRA
+ ori r4,r4,(1 << (63-60))
+ mtspr SPRN_MMCRA,r4
+ xori r4,r4,(1 << (63-60))
+ mtspr SPRN_MMCRA,r4
+ ld r4,_MMCR0(r1)
+ mtspr SPRN_MMCR0,r4
1:
/*
* POWER ISA 3. Use PSSCR to determine if we