diff mbox series

[v2] add pmu to amlogic meson sm1

Message ID 20220206144343.2194-1-crawford.benjamin15@gmail.com (mailing list archive)
State New, archived
Headers show
Series [v2] add pmu to amlogic meson sm1 | expand

Commit Message

Benjamin Mordaunt Feb. 6, 2022, 2:43 p.m. UTC
---
The dts for meson sm1 appears to omit the SoC's PMU,
which is essential for accessing perf events regarding
e.g. cache on e.g. the Odroid C4 platform. Add it.

 arch/arm64/boot/dts/amlogic/meson-sm1.dtsi | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

Comments

Neil Armstrong Feb. 7, 2022, 8:14 a.m. UTC | #1
Hi,

On 06/02/2022 15:43, Benjamin Mordaunt wrote:
> ---
> The dts for meson sm1 appears to omit the SoC's PMU,
> which is essential for accessing perf events regarding
> e.g. cache on e.g. the Odroid C4 platform. Add it.
> 
>   arch/arm64/boot/dts/amlogic/meson-sm1.dtsi | 13 ++++++++++++-
>   1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
> index 3d8b1f4f2..4147eecd2 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
> +++ b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
> @@ -6,6 +6,8 @@
>   
>   #include "meson-g12-common.dtsi"
>   #include <dt-bindings/clock/axg-audio-clkc.h>
> +#include <dt-bindings/interrupt-controller/irq.h>
> +#include <dt-bindings/interrupt-controller/arm-gic.h>
>   #include <dt-bindings/power/meson-sm1-power.h>
>   #include <dt-bindings/reset/amlogic,meson-axg-audio-arb.h>
>   #include <dt-bindings/reset/amlogic,meson-g12a-audio-reset.h>
> @@ -90,7 +92,16 @@ l2: l2-cache0 {
>   			compatible = "cache";
>   		};
>   	};
> -
> +	
> +	arm-pmu {
> +		compatible = "arm,cortex-a55-pmu";
> +		interrupts = <GIC_SPI 137 IRQ_TYPE_LEVEL_HIGH>,
> +			     <GIC_SPI 138 IRQ_TYPE_LEVEL_HIGH>,
> +			     <GIC_SPI 153 IRQ_TYPE_LEVEL_HIGH>,
> +			     <GIC_SPI 154 IRQ_TYPE_LEVEL_HIGH>;
> +		interrupt-affinity = <&cpu0>, <&cpu1>, <&cpu2>, <&cpu3>;
> +	};
> +	
>   	cpu_opp_table: opp-table {
>   		compatible = "operating-points-v2";
>   		opp-shared;

Please see Marc's comments about PMU support:
http://lore.kernel.org/r/8735pcq63o.wl-maz@kernel.org

Neil
Robin Murphy Feb. 7, 2022, 1:20 p.m. UTC | #2
On 2022-02-07 08:14, Neil Armstrong wrote:
> Hi,
> 
> On 06/02/2022 15:43, Benjamin Mordaunt wrote:
>> ---
>> The dts for meson sm1 appears to omit the SoC's PMU,
>> which is essential for accessing perf events regarding
>> e.g. cache on e.g. the Odroid C4 platform. Add it.
>>
>>   arch/arm64/boot/dts/amlogic/meson-sm1.dtsi | 13 ++++++++++++-
>>   1 file changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi 
>> b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
>> index 3d8b1f4f2..4147eecd2 100644
>> --- a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
>> +++ b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
>> @@ -6,6 +6,8 @@
>>   #include "meson-g12-common.dtsi"
>>   #include <dt-bindings/clock/axg-audio-clkc.h>
>> +#include <dt-bindings/interrupt-controller/irq.h>
>> +#include <dt-bindings/interrupt-controller/arm-gic.h>
>>   #include <dt-bindings/power/meson-sm1-power.h>
>>   #include <dt-bindings/reset/amlogic,meson-axg-audio-arb.h>
>>   #include <dt-bindings/reset/amlogic,meson-g12a-audio-reset.h>
>> @@ -90,7 +92,16 @@ l2: l2-cache0 {
>>               compatible = "cache";
>>           };
>>       };
>> -
>> +
>> +    arm-pmu {
>> +        compatible = "arm,cortex-a55-pmu";
>> +        interrupts = <GIC_SPI 137 IRQ_TYPE_LEVEL_HIGH>,
>> +                 <GIC_SPI 138 IRQ_TYPE_LEVEL_HIGH>,
>> +                 <GIC_SPI 153 IRQ_TYPE_LEVEL_HIGH>,
>> +                 <GIC_SPI 154 IRQ_TYPE_LEVEL_HIGH>;
>> +        interrupt-affinity = <&cpu0>, <&cpu1>, <&cpu2>, <&cpu3>;
>> +    };
>> +
>>       cpu_opp_table: opp-table {
>>           compatible = "operating-points-v2";
>>           opp-shared;
> 
> Please see Marc's comments about PMU support:
> http://lore.kernel.org/r/8735pcq63o.wl-maz@kernel.org

If SM1 actually has distinct per-core interrupts as the patch implies 
then it's fine - it's only G12B and anything else that combines multiple 
PMU IRQs into a single SPI which are unsupportable.

Robin.
Robin Murphy Feb. 7, 2022, 1:47 p.m. UTC | #3
On 2022-02-07 13:33, Benjamin Mordaunt wrote:
> The S905X3’s (Odroid C4) datasheet appears to report 4 individual PMUIRQs,
> much in the same way as GX. If that is indeed the case, I think this patch
> applies. Otherwise, is the datasheet wrong if Marc’s comments apply?

A fairly solid test would be to run a sampling event (e.g. `perf stat`) 
taskset to a single CPU and observe the corresponding IRQ count increase 
in /proc/interrupts, for each core in turn. If that behaves as expected 
then chances are everything is indeed sane.

Couple of nitpicks for the patch itself - you're almost there, but 
you've got spurious tabs on the blank lines, plus you need a proper 
commit message and your sign-off above the "---" line - anything you add 
below there is treated as additional commentary for reviewers' benefit 
and will be discarded by `git am`.

Cheers,
Robin.

> 
> / Ben
> 
> On Mon, 7 Feb 2022 at 13:20, Robin Murphy <robin.murphy@arm.com> wrote:
> 
>> On 2022-02-07 08:14, Neil Armstrong wrote:
>>> Hi,
>>>
>>> On 06/02/2022 15:43, Benjamin Mordaunt wrote:
>>>> ---
>>>> The dts for meson sm1 appears to omit the SoC's PMU,
>>>> which is essential for accessing perf events regarding
>>>> e.g. cache on e.g. the Odroid C4 platform. Add it.
>>>>
>>>>    arch/arm64/boot/dts/amlogic/meson-sm1.dtsi | 13 ++++++++++++-
>>>>    1 file changed, 12 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
>>>> b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
>>>> index 3d8b1f4f2..4147eecd2 100644
>>>> --- a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
>>>> +++ b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
>>>> @@ -6,6 +6,8 @@
>>>>    #include "meson-g12-common.dtsi"
>>>>    #include <dt-bindings/clock/axg-audio-clkc.h>
>>>> +#include <dt-bindings/interrupt-controller/irq.h>
>>>> +#include <dt-bindings/interrupt-controller/arm-gic.h>
>>>>    #include <dt-bindings/power/meson-sm1-power.h>
>>>>    #include <dt-bindings/reset/amlogic,meson-axg-audio-arb.h>
>>>>    #include <dt-bindings/reset/amlogic,meson-g12a-audio-reset.h>
>>>> @@ -90,7 +92,16 @@ l2: l2-cache0 {
>>>>                compatible = "cache";
>>>>            };
>>>>        };
>>>> -
>>>> +
>>>> +    arm-pmu {
>>>> +        compatible = "arm,cortex-a55-pmu";
>>>> +        interrupts = <GIC_SPI 137 IRQ_TYPE_LEVEL_HIGH>,
>>>> +                 <GIC_SPI 138 IRQ_TYPE_LEVEL_HIGH>,
>>>> +                 <GIC_SPI 153 IRQ_TYPE_LEVEL_HIGH>,
>>>> +                 <GIC_SPI 154 IRQ_TYPE_LEVEL_HIGH>;
>>>> +        interrupt-affinity = <&cpu0>, <&cpu1>, <&cpu2>, <&cpu3>;
>>>> +    };
>>>> +
>>>>        cpu_opp_table: opp-table {
>>>>            compatible = "operating-points-v2";
>>>>            opp-shared;
>>>
>>> Please see Marc's comments about PMU support:
>>> http://lore.kernel.org/r/8735pcq63o.wl-maz@kernel.org
>>
>> If SM1 actually has distinct per-core interrupts as the patch implies
>> then it's fine - it's only G12B and anything else that combines multiple
>> PMU IRQs into a single SPI which are unsupportable.
>>
>> Robin.
>>
>
Benjamin Mordaunt Feb. 8, 2022, 4:02 p.m. UTC | #4
Okay so this does appear to be behaving with some issues (unless I've
just got 2 of the interrupt numbers wrong, but it seems unlikely at
this stage).

CPUs 0 and 1 seem to be behaving somewhat sensibly, while `perf stat`
reports `<not supported>` for caches and branches with CPUs 2 and 3.
Would this suggest this implementation is indeed broken?

Thanks,
Ben


On Mon, Feb 7, 2022 at 1:47 PM Robin Murphy <robin.murphy@arm.com> wrote:
>
> On 2022-02-07 13:33, Benjamin Mordaunt wrote:
> > The S905X3’s (Odroid C4) datasheet appears to report 4 individual PMUIRQs,
> > much in the same way as GX. If that is indeed the case, I think this patch
> > applies. Otherwise, is the datasheet wrong if Marc’s comments apply?
>
> A fairly solid test would be to run a sampling event (e.g. `perf stat`)
> taskset to a single CPU and observe the corresponding IRQ count increase
> in /proc/interrupts, for each core in turn. If that behaves as expected
> then chances are everything is indeed sane.
>
> Couple of nitpicks for the patch itself - you're almost there, but
> you've got spurious tabs on the blank lines, plus you need a proper
> commit message and your sign-off above the "---" line - anything you add
> below there is treated as additional commentary for reviewers' benefit
> and will be discarded by `git am`.
>
> Cheers,
> Robin.
>
> >
> > / Ben
> >
> > On Mon, 7 Feb 2022 at 13:20, Robin Murphy <robin.murphy@arm.com> wrote:
> >
> >> On 2022-02-07 08:14, Neil Armstrong wrote:
> >>> Hi,
> >>>
> >>> On 06/02/2022 15:43, Benjamin Mordaunt wrote:
> >>>> ---
> >>>> The dts for meson sm1 appears to omit the SoC's PMU,
> >>>> which is essential for accessing perf events regarding
> >>>> e.g. cache on e.g. the Odroid C4 platform. Add it.
> >>>>
> >>>>    arch/arm64/boot/dts/amlogic/meson-sm1.dtsi | 13 ++++++++++++-
> >>>>    1 file changed, 12 insertions(+), 1 deletion(-)
> >>>>
> >>>> diff --git a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
> >>>> b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
> >>>> index 3d8b1f4f2..4147eecd2 100644
> >>>> --- a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
> >>>> +++ b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
> >>>> @@ -6,6 +6,8 @@
> >>>>    #include "meson-g12-common.dtsi"
> >>>>    #include <dt-bindings/clock/axg-audio-clkc.h>
> >>>> +#include <dt-bindings/interrupt-controller/irq.h>
> >>>> +#include <dt-bindings/interrupt-controller/arm-gic.h>
> >>>>    #include <dt-bindings/power/meson-sm1-power.h>
> >>>>    #include <dt-bindings/reset/amlogic,meson-axg-audio-arb.h>
> >>>>    #include <dt-bindings/reset/amlogic,meson-g12a-audio-reset.h>
> >>>> @@ -90,7 +92,16 @@ l2: l2-cache0 {
> >>>>                compatible = "cache";
> >>>>            };
> >>>>        };
> >>>> -
> >>>> +
> >>>> +    arm-pmu {
> >>>> +        compatible = "arm,cortex-a55-pmu";
> >>>> +        interrupts = <GIC_SPI 137 IRQ_TYPE_LEVEL_HIGH>,
> >>>> +                 <GIC_SPI 138 IRQ_TYPE_LEVEL_HIGH>,
> >>>> +                 <GIC_SPI 153 IRQ_TYPE_LEVEL_HIGH>,
> >>>> +                 <GIC_SPI 154 IRQ_TYPE_LEVEL_HIGH>;
> >>>> +        interrupt-affinity = <&cpu0>, <&cpu1>, <&cpu2>, <&cpu3>;
> >>>> +    };
> >>>> +
> >>>>        cpu_opp_table: opp-table {
> >>>>            compatible = "operating-points-v2";
> >>>>            opp-shared;
> >>>
> >>> Please see Marc's comments about PMU support:
> >>> http://lore.kernel.org/r/8735pcq63o.wl-maz@kernel.org
> >>
> >> If SM1 actually has distinct per-core interrupts as the patch implies
> >> then it's fine - it's only G12B and anything else that combines multiple
> >> PMU IRQs into a single SPI which are unsupportable.
> >>
> >> Robin.
> >>
> >
Robin Murphy Feb. 8, 2022, 4:36 p.m. UTC | #5
On 2022-02-08 16:02, Benjamin Mordaunt wrote:
> Okay so this does appear to be behaving with some issues (unless I've
> just got 2 of the interrupt numbers wrong, but it seems unlikely at
> this stage).
> 
> CPUs 0 and 1 seem to be behaving somewhat sensibly, while `perf stat`
> reports `<not supported>` for caches and branches with CPUs 2 and 3.
> Would this suggest this implementation is indeed broken?

Taking a closer look, the interrupts for CPUs 2 and 3 here are clearly 
wrong since they already belong to some audio controllers in the DTSI. I 
looked up documentation and found an S905D3 manual from Khadas which 
documents SPI 137 (GIC interrupt 169) as "|PMUIRQ_a[3:0]", which I can't 
read as anything other than "logical OR of all 4 PMU IRQs". Not sure 
about SPI 138 but I'd guess it's something that just happens to fire in 
a manner that appears to sort of work for the PMU.

Sadly it looks like Neil's instinct was right and this one is also in 
fact dead, sorry :(

Robin.

> 
> Thanks,
> Ben
> 
> 
> On Mon, Feb 7, 2022 at 1:47 PM Robin Murphy <robin.murphy@arm.com> wrote:
>>
>> On 2022-02-07 13:33, Benjamin Mordaunt wrote:
>>> The S905X3’s (Odroid C4) datasheet appears to report 4 individual PMUIRQs,
>>> much in the same way as GX. If that is indeed the case, I think this patch
>>> applies. Otherwise, is the datasheet wrong if Marc’s comments apply?
>>
>> A fairly solid test would be to run a sampling event (e.g. `perf stat`)
>> taskset to a single CPU and observe the corresponding IRQ count increase
>> in /proc/interrupts, for each core in turn. If that behaves as expected
>> then chances are everything is indeed sane.
>>
>> Couple of nitpicks for the patch itself - you're almost there, but
>> you've got spurious tabs on the blank lines, plus you need a proper
>> commit message and your sign-off above the "---" line - anything you add
>> below there is treated as additional commentary for reviewers' benefit
>> and will be discarded by `git am`.
>>
>> Cheers,
>> Robin.
>>
>>>
>>> / Ben
>>>
>>> On Mon, 7 Feb 2022 at 13:20, Robin Murphy <robin.murphy@arm.com> wrote:
>>>
>>>> On 2022-02-07 08:14, Neil Armstrong wrote:
>>>>> Hi,
>>>>>
>>>>> On 06/02/2022 15:43, Benjamin Mordaunt wrote:
>>>>>> ---
>>>>>> The dts for meson sm1 appears to omit the SoC's PMU,
>>>>>> which is essential for accessing perf events regarding
>>>>>> e.g. cache on e.g. the Odroid C4 platform. Add it.
>>>>>>
>>>>>>     arch/arm64/boot/dts/amlogic/meson-sm1.dtsi | 13 ++++++++++++-
>>>>>>     1 file changed, 12 insertions(+), 1 deletion(-)
>>>>>>
>>>>>> diff --git a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
>>>>>> b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
>>>>>> index 3d8b1f4f2..4147eecd2 100644
>>>>>> --- a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
>>>>>> +++ b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
>>>>>> @@ -6,6 +6,8 @@
>>>>>>     #include "meson-g12-common.dtsi"
>>>>>>     #include <dt-bindings/clock/axg-audio-clkc.h>
>>>>>> +#include <dt-bindings/interrupt-controller/irq.h>
>>>>>> +#include <dt-bindings/interrupt-controller/arm-gic.h>
>>>>>>     #include <dt-bindings/power/meson-sm1-power.h>
>>>>>>     #include <dt-bindings/reset/amlogic,meson-axg-audio-arb.h>
>>>>>>     #include <dt-bindings/reset/amlogic,meson-g12a-audio-reset.h>
>>>>>> @@ -90,7 +92,16 @@ l2: l2-cache0 {
>>>>>>                 compatible = "cache";
>>>>>>             };
>>>>>>         };
>>>>>> -
>>>>>> +
>>>>>> +    arm-pmu {
>>>>>> +        compatible = "arm,cortex-a55-pmu";
>>>>>> +        interrupts = <GIC_SPI 137 IRQ_TYPE_LEVEL_HIGH>,
>>>>>> +                 <GIC_SPI 138 IRQ_TYPE_LEVEL_HIGH>,
>>>>>> +                 <GIC_SPI 153 IRQ_TYPE_LEVEL_HIGH>,
>>>>>> +                 <GIC_SPI 154 IRQ_TYPE_LEVEL_HIGH>;
>>>>>> +        interrupt-affinity = <&cpu0>, <&cpu1>, <&cpu2>, <&cpu3>;
>>>>>> +    };
>>>>>> +
>>>>>>         cpu_opp_table: opp-table {
>>>>>>             compatible = "operating-points-v2";
>>>>>>             opp-shared;
>>>>>
>>>>> Please see Marc's comments about PMU support:
>>>>> http://lore.kernel.org/r/8735pcq63o.wl-maz@kernel.org
>>>>
>>>> If SM1 actually has distinct per-core interrupts as the patch implies
>>>> then it's fine - it's only G12B and anything else that combines multiple
>>>> PMU IRQs into a single SPI which are unsupportable.
>>>>
>>>> Robin.
>>>>
>>>
diff mbox series

Patch

diff --git a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
index 3d8b1f4f2..4147eecd2 100644
--- a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi
@@ -6,6 +6,8 @@ 
 
 #include "meson-g12-common.dtsi"
 #include <dt-bindings/clock/axg-audio-clkc.h>
+#include <dt-bindings/interrupt-controller/irq.h>
+#include <dt-bindings/interrupt-controller/arm-gic.h>
 #include <dt-bindings/power/meson-sm1-power.h>
 #include <dt-bindings/reset/amlogic,meson-axg-audio-arb.h>
 #include <dt-bindings/reset/amlogic,meson-g12a-audio-reset.h>
@@ -90,7 +92,16 @@  l2: l2-cache0 {
 			compatible = "cache";
 		};
 	};
-
+	
+	arm-pmu {
+		compatible = "arm,cortex-a55-pmu";
+		interrupts = <GIC_SPI 137 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 138 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 153 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 154 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-affinity = <&cpu0>, <&cpu1>, <&cpu2>, <&cpu3>;
+	};
+	
 	cpu_opp_table: opp-table {
 		compatible = "operating-points-v2";
 		opp-shared;