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-rw-r--r--arch/powerpc/kernel/idle_book3s.S8
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index 516ebef905c0..e6252c5a57a4 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -460,11 +460,17 @@ pnv_restore_hyp_resource_arch300:
/*
* Workaround for POWER9, if we lost resources, the ERAT
* might have been mixed up and needs flushing. We also need
- * to reload MMCR0 (see comment above).
+ * 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: