Re: [PATCH] ARM64: dts: rockchip: add core dtsi file for RK3399 SoCs

[Marc Zyngier <marc.zyngier-5wv7dgnIgG8@public.gmane.org>]

On 25/04/16 10:48, Huang, Tao wrote:
> Hi, Marc:
> On 2016年04月21日 19:30, Marc Zyngier wrote:
>> On Thu, 21 Apr 2016 18:47:20 +0800
>> "Huang, Tao" <huangtao-TNX95d0MmH7DzftRWevZcw@public.gmane.org> wrote:
>>
>>> Hi, Mark:
>>> On 2016年04月21日 18:19, Mark Rutland wrote:
>>>> On Thu, Apr 21, 2016 at 11:58:12AM +0800, Jianqun Xu wrote:
>>>>> +		cpu_l0: cpu@0 {
>>>>> +			device_type = "cpu";
>>>>> +			compatible = "arm,cortex-a53", "arm,armv8";
>>>>> +			reg = <0x0 0x0>;
>>>>> +			enable-method = "psci";
>>>>> +			#cooling-cells = <2>; /* min followed by max */
>>>>> +			clocks = <&cru ARMCLKL>;
>>>>> +		};
>>>>> +		cpu_b0: cpu@100 {
>>>>> +			device_type = "cpu";
>>>>> +			compatible = "arm,cortex-a72", "arm,armv8";
>>>>> +			reg = <0x0 0x100>;
>>>>> +			enable-method = "psci";
>>>>> +			#cooling-cells = <2>; /* min followed by max */
>>>>> +			clocks = <&cru ARMCLKB>;
>>>>> +		};
>>>>> +
>>>>> +	arm-pmu {
>>>>> +		compatible = "arm,armv8-pmuv3";
>>>>> +		interrupts = <GIC_PPI 7 IRQ_TYPE_LEVEL_LOW>;
>>>>> +	};
>>>> This is wrong, and must go. There should be a separate node for the PMU
>>>> of each microarchitecture, with the appropriate compatible string to
>>>> represent that (see the juno dts).
>>> You are right. The first version we wrote is:
>>>     pmu_a53 {
>>>         compatible = "arm,cortex-a53-pmu";
>>>         interrupts = <GIC_PPI 7 IRQ_TYPE_LEVEL_LOW>;
>>>         interrupt-affinity = <&cpu_l0>,
>>>                      <&cpu_l1>,
>>>                      <&cpu_l2>,
>>>                      <&cpu_l3>;
>>>     };
>>>
>>>     pmu_a72 {
>>>         compatible = "arm,cortex-a72-pmu";
>>>         interrupts = <GIC_PPI 7 IRQ_TYPE_LEVEL_LOW>;
>>>         interrupt-affinity = <&cpu_b0>,
>>>                      <&cpu_b1>;
>>>     };
>>> but unfortunately, the arm pmu driver do not support PPI in two cluster
>>> well,
>>> so we have to replace with this implementation.
>>>> In this case things are messier as the same PPI number is being used
>>>> across clusters. Marc (Cc'd) has been working on PPI partitions, which
>>>> should allow us to support that.
>>> Great! So what we can do right now? Wait this feature, and delete
>>> arm-pmu node?
>> I'd rather you have a look at the patches, test them with your HW,
>> and comment on what doesn't work!
>>
>> You can find the patches over there:
>>
>> https://lkml.org/lkml/2016/4/11/182
>>
>> and on the following branch:
>>
>> git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git
>> irq/percpu-partition
> 
> I tested these patches. Because our kernel is based on v4.4, so I back
> port most changes about
> include/linux/irqdomain.h
> kernel/irq/irqdomain.c
> drivers/irqchip/irq-gic-v3.c
> and change rk3399.dtsi base on your arm,gic-v3.txt:
> 
>      gic: interrupt-controller@fee00000 {
>          compatible = "arm,gic-v3";
> -        #interrupt-cells = <3>;
> +        #interrupt-cells = <4>;
>          #address-cells = <2>;
>          #size-cells = <2>;
> ...
> +
> +        ppi-partitions {
> +            part0: interrupt-partition-0 {
> +                affinity = <&cpu_l0 &cpu_l1 &cpu_l2 &cpu_l3>;
> +            };
> +
> +            part1: interrupt-partition-1 {
> +                affinity = <&cpu_b0 &cpu_b1>;
> +            };
> +        };
> 
> and change every interrupts from three cells to four cells, such as
>      saradc: saradc@ff100000 {
>          compatible = "rockchip,rk3399-saradc";
>          reg = <0x0 0xff100000 0x0 0x100>;
> -        interrupts = <GIC_SPI 62 IRQ_TYPE_LEVEL_HIGH>;
> +        interrupts = <GIC_SPI 62 IRQ_TYPE_LEVEL_HIGH 0>;
>          #io-channel-cells = <1>;
>          clocks = <&cru SCLK_SARADC>, <&cru PCLK_SARADC>;
>          clock-names = "saradc", "apb_pclk";
> 
> and pmu define as:
>     pmu_a53 {
>         compatible = "arm,cortex-a53-pmu";
>         interrupts = <GIC_PPI 7 IRQ_TYPE_LEVEL_LOW &part0>;
>         interrupt-affinity = <&cpu_l0>,
>                      <&cpu_l1>,
>                      <&cpu_l2>,
>                      <&cpu_l3>;
>     };
> 
>     pmu_a72 {
>         compatible = "arm,cortex-a72-pmu", "arm,cortex-a57-pmu";
>         interrupts = <GIC_PPI 7 IRQ_TYPE_LEVEL_LOW &part1>;
>         interrupt-affinity = <&cpu_b0>,
>                      <&cpu_b1>;
>     };
> 
> It can boot. And I test with Android simpleperf stat and perf top, it works!
> So these patches work on RK3399.

Good, thanks for testing.

> But as I mentioned, we must change every interrupt in dts, do you think
> this is acceptable?

I can't see why not.

>>
>> Of course, you'll have to hack a bit in the PMU code to make it
>> understand per-PMU affinity together with percpu interrupts, but it
>> wouldn't be fun if there was nothing to do...
> I don't change drivers/perf/arm_pmu.c, it just work.

Having had a look with Mark, it may work, but it is rather unsafe. I may
have a go at it, but I'm going to have to rely on you to test it (or you
can send me a board ;-).

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...
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