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* [PATCH] perf/arm-cmn: Move overlapping wp_combine field
@ 2023-03-01 17:55 Ilkka Koskinen
  2023-03-01 18:39 ` Robin Murphy
  2023-03-27 15:01 ` Will Deacon
  0 siblings, 2 replies; 5+ messages in thread
From: Ilkka Koskinen @ 2023-03-01 17:55 UTC (permalink / raw)
  To: Robin Murphy, Will Deacon
  Cc: Mark Rutland, linux-arm-kernel, Ilkka Koskinen, patches

As eventid field was expanded to support new mesh versions, it started to
overlap with wp_combine field. Move wp_combine to fix the issue.

Fixes: 23760a014417 ("perf/arm-cmn: Add CMN-700 support")
Signed-off-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
---
 drivers/perf/arm-cmn.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
index c9689861be3f..9f2edc28d16e 100644
--- a/drivers/perf/arm-cmn.c
+++ b/drivers/perf/arm-cmn.c
@@ -166,7 +166,7 @@
 #define CMN_EVENT_BYNODEID(event)	FIELD_GET(CMN_CONFIG_BYNODEID, (event)->attr.config)
 #define CMN_EVENT_NODEID(event)		FIELD_GET(CMN_CONFIG_NODEID, (event)->attr.config)
 
-#define CMN_CONFIG_WP_COMBINE		GENMASK_ULL(27, 24)
+#define CMN_CONFIG_WP_COMBINE		GENMASK_ULL(30, 27)
 #define CMN_CONFIG_WP_DEV_SEL		GENMASK_ULL(50, 48)
 #define CMN_CONFIG_WP_CHN_SEL		GENMASK_ULL(55, 51)
 /* Note that we don't yet support the tertiary match group on newer IPs */
-- 
2.17.1


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^ permalink raw reply related	[flat|nested] 5+ messages in thread
* Re: [PATCH] perf/arm-cmn: Move overlapping wp_combine field
  2023-03-01 17:55 [PATCH] perf/arm-cmn: Move overlapping wp_combine field Ilkka Koskinen
@ 2023-03-01 18:39 ` Robin Murphy
  2023-03-02  0:55   ` Ilkka Koskinen
  2023-03-27 15:01 ` Will Deacon
  1 sibling, 1 reply; 5+ messages in thread
From: Robin Murphy @ 2023-03-01 18:39 UTC (permalink / raw)
  To: Ilkka Koskinen, Will Deacon; +Cc: Mark Rutland, linux-arm-kernel, patches

On 2023-03-01 17:55, Ilkka Koskinen wrote:
> As eventid field was expanded to support new mesh versions, it started to
> overlap with wp_combine field. Move wp_combine to fix the issue.

Watchpoint events still only strictly need 2 bits of eventid, though. 
Could you clarify whether userspace is getting confused by this, or 
whether it's just arm_cmn_event_init() falling over itself (FWIW I can 
see how I broke things there...)

Thanks,
Robin.

> Fixes: 23760a014417 ("perf/arm-cmn: Add CMN-700 support")
> Signed-off-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
> ---
>   drivers/perf/arm-cmn.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
> index c9689861be3f..9f2edc28d16e 100644
> --- a/drivers/perf/arm-cmn.c
> +++ b/drivers/perf/arm-cmn.c
> @@ -166,7 +166,7 @@
>   #define CMN_EVENT_BYNODEID(event)	FIELD_GET(CMN_CONFIG_BYNODEID, (event)->attr.config)
>   #define CMN_EVENT_NODEID(event)		FIELD_GET(CMN_CONFIG_NODEID, (event)->attr.config)
>   
> -#define CMN_CONFIG_WP_COMBINE		GENMASK_ULL(27, 24)
> +#define CMN_CONFIG_WP_COMBINE		GENMASK_ULL(30, 27)
>   #define CMN_CONFIG_WP_DEV_SEL		GENMASK_ULL(50, 48)
>   #define CMN_CONFIG_WP_CHN_SEL		GENMASK_ULL(55, 51)
>   /* Note that we don't yet support the tertiary match group on newer IPs */

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^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH] perf/arm-cmn: Move overlapping wp_combine field
  2023-03-01 18:39 ` Robin Murphy
@ 2023-03-02  0:55   ` Ilkka Koskinen
  2023-03-20 23:47     ` Ilkka Koskinen
  0 siblings, 1 reply; 5+ messages in thread
From: Ilkka Koskinen @ 2023-03-02  0:55 UTC (permalink / raw)
  To: Robin Murphy
  Cc: Ilkka Koskinen, Will Deacon, Mark Rutland, linux-arm-kernel, patches


Hi Robin,

On Wed, 1 Mar 2023, Robin Murphy wrote:
> On 2023-03-01 17:55, Ilkka Koskinen wrote:
>> As eventid field was expanded to support new mesh versions, it started to
>> overlap with wp_combine field. Move wp_combine to fix the issue.
>
> Watchpoint events still only strictly need 2 bits of eventid, though. Could 
> you clarify whether userspace is getting confused by this, or whether it's 
> just arm_cmn_event_init() falling over itself (FWIW I can see how I broke 
> things there...)

Basically, perf seems to set eventid at first and then wp_combine field 
into the config argument. The problem is when arm_cmn_event_init() is 
doing:

 	eventid = CMN_EVENT_EVENTID(event);
 	....
 	if (eventid != CMN_WP_UP && eventid != CMN_WP_DOWN)
 		return -EINVAL;

If wp_combine has any of the overlapping bits set, eventid doesn't match 
with either up or down event.

Cheers, Ilkka

>
> Thanks,
> Robin.
>
>> Fixes: 23760a014417 ("perf/arm-cmn: Add CMN-700 support")
>> Signed-off-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
>> ---
>>   drivers/perf/arm-cmn.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
>> index c9689861be3f..9f2edc28d16e 100644
>> --- a/drivers/perf/arm-cmn.c
>> +++ b/drivers/perf/arm-cmn.c
>> @@ -166,7 +166,7 @@
>>   #define CMN_EVENT_BYNODEID(event)	FIELD_GET(CMN_CONFIG_BYNODEID, 
>> (event)->attr.config)
>>   #define CMN_EVENT_NODEID(event)		FIELD_GET(CMN_CONFIG_NODEID, 
>> (event)->attr.config)
>>   -#define CMN_CONFIG_WP_COMBINE		GENMASK_ULL(27, 24)
>> +#define CMN_CONFIG_WP_COMBINE		GENMASK_ULL(30, 27)
>>   #define CMN_CONFIG_WP_DEV_SEL		GENMASK_ULL(50, 48)
>>   #define CMN_CONFIG_WP_CHN_SEL		GENMASK_ULL(55, 51)
>>   /* Note that we don't yet support the tertiary match group on newer IPs 
>> */
>

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^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH] perf/arm-cmn: Move overlapping wp_combine field
  2023-03-02  0:55   ` Ilkka Koskinen
@ 2023-03-20 23:47     ` Ilkka Koskinen
  0 siblings, 0 replies; 5+ messages in thread
From: Ilkka Koskinen @ 2023-03-20 23:47 UTC (permalink / raw)
  To: Robin Murphy; +Cc: Will Deacon, Mark Rutland, linux-arm-kernel, patches


Hi Robin,

On Wed, 1 Mar 2023, Ilkka Koskinen wrote:
>
> Hi Robin,
>
> On Wed, 1 Mar 2023, Robin Murphy wrote:
>> On 2023-03-01 17:55, Ilkka Koskinen wrote:
>>> As eventid field was expanded to support new mesh versions, it started to
>>> overlap with wp_combine field. Move wp_combine to fix the issue.
>> 
>> Watchpoint events still only strictly need 2 bits of eventid, though. Could 
>> you clarify whether userspace is getting confused by this, or whether it's 
>> just arm_cmn_event_init() falling over itself (FWIW I can see how I broke 
>> things there...)
>
> Basically, perf seems to set eventid at first and then wp_combine field into 
> the config argument. The problem is when arm_cmn_event_init() is doing:
>
> 	eventid = CMN_EVENT_EVENTID(event);
> 	....
> 	if (eventid != CMN_WP_UP && eventid != CMN_WP_DOWN)
> 		return -EINVAL;
>
> If wp_combine has any of the overlapping bits set, eventid doesn't match with 
> either up or down event.

I probably should have also copy pasted what the format files say:

 	$ cat format/eventid format/wp_combine
 	config:16-26
 	config:24-27

So, here you can see that those two fields overlap. If wp_combine has any 
of the bits 24-26 set, arm_cmn_event_init() returns -EINVAL as shown in 
the code above.

Would you need some more clarification from me?

Br, Ilkka


>
> Cheers, Ilkka
>
>> 
>> Thanks,
>> Robin.
>> 
>>> Fixes: 23760a014417 ("perf/arm-cmn: Add CMN-700 support")
>>> Signed-off-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
>>> ---
>>>   drivers/perf/arm-cmn.c | 2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>> 
>>> diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
>>> index c9689861be3f..9f2edc28d16e 100644
>>> --- a/drivers/perf/arm-cmn.c
>>> +++ b/drivers/perf/arm-cmn.c
>>> @@ -166,7 +166,7 @@
>>>   #define CMN_EVENT_BYNODEID(event)	FIELD_GET(CMN_CONFIG_BYNODEID, 
>>> (event)->attr.config)
>>>   #define CMN_EVENT_NODEID(event)		FIELD_GET(CMN_CONFIG_NODEID, 
>>> (event)->attr.config)
>>>   -#define CMN_CONFIG_WP_COMBINE		GENMASK_ULL(27, 24)
>>> +#define CMN_CONFIG_WP_COMBINE		GENMASK_ULL(30, 27)
>>>   #define CMN_CONFIG_WP_DEV_SEL		GENMASK_ULL(50, 48)
>>>   #define CMN_CONFIG_WP_CHN_SEL		GENMASK_ULL(55, 51)
>>>   /* Note that we don't yet support the tertiary match group on newer IPs 
>>> */
>> 
>

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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: [PATCH] perf/arm-cmn: Move overlapping wp_combine field
  2023-03-01 17:55 [PATCH] perf/arm-cmn: Move overlapping wp_combine field Ilkka Koskinen
  2023-03-01 18:39 ` Robin Murphy
@ 2023-03-27 15:01 ` Will Deacon
  1 sibling, 0 replies; 5+ messages in thread
From: Will Deacon @ 2023-03-27 15:01 UTC (permalink / raw)
  To: Ilkka Koskinen, Robin Murphy
  Cc: catalin.marinas, kernel-team, Will Deacon, Mark Rutland, patches,
	linux-arm-kernel

On Wed, 1 Mar 2023 09:55:40 -0800, Ilkka Koskinen wrote:
> As eventid field was expanded to support new mesh versions, it started to
> overlap with wp_combine field. Move wp_combine to fix the issue.
> 
> 

Applied to will (for-next/perf), thanks!

[1/1] perf/arm-cmn: Move overlapping wp_combine field
      https://git.kernel.org/will/c/f87e9114b5e5

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev

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^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2023-03-27 15:02 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-03-01 17:55 [PATCH] perf/arm-cmn: Move overlapping wp_combine field Ilkka Koskinen
2023-03-01 18:39 ` Robin Murphy
2023-03-02  0:55   ` Ilkka Koskinen
2023-03-20 23:47     ` Ilkka Koskinen
2023-03-27 15:01 ` Will Deacon

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