[PATCH 5.2 391/413] powerpc/powernv/idle: Fix restore of SPRN_LDBAR for POWER9 stop state.

From: Greg Kroah-Hartman
Date: Wed Jul 24 2019 - 15:43:15 EST


From: Athira Rajeev <atrajeev@xxxxxxxxxxxxxxxxxx>

commit f5a9e488d62360c91c5770bd55a0b40e419a71ce upstream.

commit 10d91611f426 ("powerpc/64s: Reimplement book3s idle code in C")
reimplemented book3S code to pltform/powernv/idle.c. But when doing so
missed to add the per-thread LDBAR update in the core_woken path of
the power9_idle_stop(). Patch fixes the same.

Fixes: 10d91611f426 ("powerpc/64s: Reimplement book3s idle code in C")
Cc: stable@xxxxxxxxxxxxxxx # v5.2+
Signed-off-by: Athira Rajeev <atrajeev@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Madhavan Srinivasan <maddy@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20190702105836.26695-1-maddy@xxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/powerpc/platforms/powernv/idle.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -758,7 +758,6 @@ static unsigned long power9_idle_stop(un
mtspr(SPRN_PTCR, sprs.ptcr);
mtspr(SPRN_RPR, sprs.rpr);
mtspr(SPRN_TSCR, sprs.tscr);
- mtspr(SPRN_LDBAR, sprs.ldbar);

if (pls >= pnv_first_tb_loss_level) {
/* TB loss */
@@ -790,6 +789,7 @@ core_woken:
mtspr(SPRN_MMCR0, sprs.mmcr0);
mtspr(SPRN_MMCR1, sprs.mmcr1);
mtspr(SPRN_MMCR2, sprs.mmcr2);
+ mtspr(SPRN_LDBAR, sprs.ldbar);

mtspr(SPRN_SPRG3, local_paca->sprg_vdso);