* [PATCH] POWER9 PMU stops after idle workaround
@ 2017-07-20 1:53 Nicholas Piggin
2017-07-20 4:13 ` Madhavan Srinivasan
` (3 more replies)
0 siblings, 4 replies; 7+ messages in thread
From: Nicholas Piggin @ 2017-07-20 1:53 UTC (permalink / raw)
To: Michael Ellerman
Cc: Nicholas Piggin, linuxppc-dev, Madhavan Srinivasan,
Anton Blanchard, Michael Neuling, Gautham R Shenoy,
Vaidyanathan Srinivasan
POWER9 DD2 PMU can stop after a state-loss idle in some conditions.
A solution is to set then clear MMCRA[60] after wake from state-loss
idle.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/idle_book3s.S | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
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:
--
2.11.0
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] POWER9 PMU stops after idle workaround
2017-07-20 1:53 [PATCH] POWER9 PMU stops after idle workaround Nicholas Piggin
@ 2017-07-20 4:13 ` Madhavan Srinivasan
2017-07-20 5:06 ` Vaidyanathan Srinivasan
` (2 subsequent siblings)
3 siblings, 0 replies; 7+ messages in thread
From: Madhavan Srinivasan @ 2017-07-20 4:13 UTC (permalink / raw)
To: linuxppc-dev
On Thursday 20 July 2017 07:23 AM, Nicholas Piggin wrote:
> POWER9 DD2 PMU can stop after a state-loss idle in some conditions.
>
> A solution is to set then clear MMCRA[60] after wake from state-loss
> idle.
Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
> arch/powerpc/kernel/idle_book3s.S | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> 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:
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] POWER9 PMU stops after idle workaround
2017-07-20 1:53 [PATCH] POWER9 PMU stops after idle workaround Nicholas Piggin
2017-07-20 4:13 ` Madhavan Srinivasan
@ 2017-07-20 5:06 ` Vaidyanathan Srinivasan
2017-08-02 4:30 ` Anton Blanchard
2017-08-03 10:19 ` Michael Ellerman
3 siblings, 0 replies; 7+ messages in thread
From: Vaidyanathan Srinivasan @ 2017-07-20 5:06 UTC (permalink / raw)
To: Nicholas Piggin
Cc: Michael Ellerman, linuxppc-dev, Madhavan Srinivasan,
Anton Blanchard, Michael Neuling, Gautham R Shenoy
* Nicholas Piggin <npiggin@gmail.com> [2017-07-20 11:53:22]:
> POWER9 DD2 PMU can stop after a state-loss idle in some conditions.
>
> A solution is to set then clear MMCRA[60] after wake from state-loss
> idle.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
> ---
> arch/powerpc/kernel/idle_book3s.S | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> 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
Timing is ok to resolve the issue? Does back-to-back bit flip of
MMCRA[60] gets the job done for all cases? Just asking since this
issue in itself is a corner case ;)
--Vaidy
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] POWER9 PMU stops after idle workaround
2017-07-20 1:53 [PATCH] POWER9 PMU stops after idle workaround Nicholas Piggin
2017-07-20 4:13 ` Madhavan Srinivasan
2017-07-20 5:06 ` Vaidyanathan Srinivasan
@ 2017-08-02 4:30 ` Anton Blanchard
2017-08-03 10:19 ` Michael Ellerman
3 siblings, 0 replies; 7+ messages in thread
From: Anton Blanchard @ 2017-08-02 4:30 UTC (permalink / raw)
To: Nicholas Piggin
Cc: Michael Ellerman, linuxppc-dev, Madhavan Srinivasan,
Michael Neuling, Gautham R Shenoy, Vaidyanathan Srinivasan
Hi Nick,
> POWER9 DD2 PMU can stop after a state-loss idle in some conditions.
>
> A solution is to set then clear MMCRA[60] after wake from state-loss
> idle.
Looks good.
Acked-by: Anton Blanchard <anton@samba.org>
Anton
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
> arch/powerpc/kernel/idle_book3s.S | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> 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:
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: POWER9 PMU stops after idle workaround
2017-07-20 1:53 [PATCH] POWER9 PMU stops after idle workaround Nicholas Piggin
` (2 preceding siblings ...)
2017-08-02 4:30 ` Anton Blanchard
@ 2017-08-03 10:19 ` Michael Ellerman
2017-09-13 16:11 ` Michal Suchánek
3 siblings, 1 reply; 7+ messages in thread
From: Michael Ellerman @ 2017-08-03 10:19 UTC (permalink / raw)
To: Nicholas Piggin
Cc: Madhavan Srinivasan, Gautham R Shenoy, Michael Neuling,
Nicholas Piggin, Anton Blanchard, linuxppc-dev
On Thu, 2017-07-20 at 01:53:22 UTC, Nicholas Piggin wrote:
> POWER9 DD2 PMU can stop after a state-loss idle in some conditions.
>
> A solution is to set then clear MMCRA[60] after wake from state-loss
> idle.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
> Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
> Acked-by: Anton Blanchard <anton@samba.org>
Applied to powerpc fixes, thanks.
https://git.kernel.org/powerpc/c/bdd21ddb919d28f9c62cdc6286cac9
cheers
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: POWER9 PMU stops after idle workaround
2017-08-03 10:19 ` Michael Ellerman
@ 2017-09-13 16:11 ` Michal Suchánek
2017-09-13 20:45 ` Michael Ellerman
0 siblings, 1 reply; 7+ messages in thread
From: Michal Suchánek @ 2017-09-13 16:11 UTC (permalink / raw)
To: Michael Ellerman
Cc: Michael Ellerman, Nicholas Piggin, Madhavan Srinivasan,
Gautham R Shenoy, Michael Neuling, Anton Blanchard, linuxppc-dev
On Thu, 3 Aug 2017 20:19:38 +1000 (AEST)
Michael Ellerman <patch-notifications@ellerman.id.au> wrote:
> On Thu, 2017-07-20 at 01:53:22 UTC, Nicholas Piggin wrote:
> > POWER9 DD2 PMU can stop after a state-loss idle in some conditions.
> >
> > A solution is to set then clear MMCRA[60] after wake from state-loss
> > idle.
> >
> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> > Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
> > Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
> > Acked-by: Anton Blanchard <anton@samba.org>
>
> Applied to powerpc fixes, thanks.
>
> https://git.kernel.org/powerpc/c/bdd21ddb919d28f9c62cdc6286cac9
>
> cheers
Not there anymore. I see this only in the merge branch.
Thanks
Michal
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: POWER9 PMU stops after idle workaround
2017-09-13 16:11 ` Michal Suchánek
@ 2017-09-13 20:45 ` Michael Ellerman
0 siblings, 0 replies; 7+ messages in thread
From: Michael Ellerman @ 2017-09-13 20:45 UTC (permalink / raw)
To: Michal Suchánek, Michael Ellerman
Cc: Michael Ellerman, Nicholas Piggin, Madhavan Srinivasan,
Gautham R Shenoy, Michael Neuling, Anton Blanchard, linuxppc-dev
[-- Attachment #1: Type: text/plain, Size: 1223 bytes --]
Yeah I messed up the subject when comitting, from memory, so I had to rebase and force push.
I think this is it:
https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id=09539f9b123652e969894d6299ae0df2fe12cb5d
cheers
On 14 September 2017 2:11:16 am AEST, "Michal Suchánek" <msuchanek@suse.de> wrote:
>On Thu, 3 Aug 2017 20:19:38 +1000 (AEST)
>Michael Ellerman <patch-notifications@ellerman.id.au> wrote:
>
>> On Thu, 2017-07-20 at 01:53:22 UTC, Nicholas Piggin wrote:
>> > POWER9 DD2 PMU can stop after a state-loss idle in some conditions.
>> >
>> > A solution is to set then clear MMCRA[60] after wake from
>state-loss
>> > idle.
>> >
>> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> > Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
>> > Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
>> > Acked-by: Anton Blanchard <anton@samba.org>
>>
>> Applied to powerpc fixes, thanks.
>>
>> https://git.kernel.org/powerpc/c/bdd21ddb919d28f9c62cdc6286cac9
>>
>> cheers
>
>Not there anymore. I see this only in the merge branch.
>
>Thanks
>
>Michal
--
Sent from my Android phone with K-9 Mail. Please excuse my brevity.
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^ permalink raw reply [flat|nested] 7+ messages in thread
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2017-07-20 1:53 [PATCH] POWER9 PMU stops after idle workaround Nicholas Piggin
2017-07-20 4:13 ` Madhavan Srinivasan
2017-07-20 5:06 ` Vaidyanathan Srinivasan
2017-08-02 4:30 ` Anton Blanchard
2017-08-03 10:19 ` Michael Ellerman
2017-09-13 16:11 ` Michal Suchánek
2017-09-13 20:45 ` Michael Ellerman
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