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

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

[Madhavan Srinivasan]

From: Athira Rajeev <atrajeev@linux.vnet.ibm.com>

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")
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
---
 arch/powerpc/platforms/powernv/idle.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index 2f4479b94ac3..fd14a6237954 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -758,7 +758,6 @@ static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
 	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 @@ static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
 	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);
 
-- 
2.20.1

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

[Nicholas Piggin]

Madhavan Srinivasan's on July 2, 2019 8:58 pm:
> From: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
> 
> 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")
> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
> Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
> ---
>  arch/powerpc/platforms/powernv/idle.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
> index 2f4479b94ac3..fd14a6237954 100644
> --- a/arch/powerpc/platforms/powernv/idle.c
> +++ b/arch/powerpc/platforms/powernv/idle.c
> @@ -758,7 +758,6 @@ static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
>  	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 @@ static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
>  	mtspr(SPRN_MMCR0,	sprs.mmcr0);
>  	mtspr(SPRN_MMCR1,	sprs.mmcr1);
>  	mtspr(SPRN_MMCR2,	sprs.mmcr2);
> +	mtspr(SPRN_LDBAR,	sprs.ldbar);

Oh that's another one I messed up, thanks for the fix. I must have
confused myself with the SPR table in the UM :(

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>

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

[Michael Ellerman]

On Tue, 2019-07-02 at 10:58:36 UTC, Madhavan Srinivasan wrote:
> From: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
> 
> 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")
> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
> Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
> Reviewed-by: Nicholas Piggin <npiggin@gmail.com>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/f5a9e488d62360c91c5770bd55a0b40e419a71ce

cheers