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

["Huang, Tao" <huangtao@rock-chips.com>]

Hi, Marc:
On 2016年04月25日 18:39, Marc Zyngier wrote:
> On 25/04/16 11:06, Marc Zyngier wrote:
>> 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@rock-chips.com> 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 ;-).
> I came up with the following (untested) patch. Please let me know if this
> works for you.
>
> Thanks,
>
> 	M.
>
> >From b88c08bb689d3fe40c46788453a07ba22dae9220 Mon Sep 17 00:00:00 2001
> From: Marc Zyngier <marc.zyngier@arm.com>
> Date: Mon, 25 Apr 2016 11:23:54 +0100
> Subject: [PATCH] drivers/perf: arm-pmu: Handle per-interrupt affinity mask
>
> On a big-little system, PMUs can be wired to CPUs using per CPU
> interrups (PPI). In this case, it is important to make sure that
> the enable/disable do happen on the right set of CPUs.
>
> Do this by querying the corresponding cpumask on the corresponding
> paths
>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  drivers/perf/arm_pmu.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
> index f700908..3de5e1c 100644
> --- a/drivers/perf/arm_pmu.c
> +++ b/drivers/perf/arm_pmu.c
> @@ -603,7 +603,11 @@ static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
>  
>  	irq = platform_get_irq(pmu_device, 0);
>  	if (irq >= 0 && irq_is_percpu(irq)) {
> -		on_each_cpu(cpu_pmu_disable_percpu_irq, &irq, 1);
> +		struct cpumask ppi_cpumask;
> +
> +		irq_get_percpu_devid_partition(irq, &ppi_cpumask);
> +		on_each_cpu_mask(&ppi_cpumask, cpu_pmu_disable_percpu_irq,
> +				 &irq, 1);
>  		free_percpu_irq(irq, &hw_events->percpu_pmu);
>  	} else {
>  		for (i = 0; i < irqs; ++i) {
> @@ -638,6 +642,8 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
>  
>  	irq = platform_get_irq(pmu_device, 0);
>  	if (irq >= 0 && irq_is_percpu(irq)) {
> +		struct cpumask ppi_cpumask;
> +
>  		err = request_percpu_irq(irq, handler, "arm-pmu",
>  					 &hw_events->percpu_pmu);
>  		if (err) {
> @@ -645,7 +651,10 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
>  				irq);
>  			return err;
>  		}
> -		on_each_cpu(cpu_pmu_enable_percpu_irq, &irq, 1);
> +
> +		irq_get_percpu_devid_partition(irq, &ppi_cpumask);
> +		on_each_cpu_mask(&ppi_cpumask, cpu_pmu_enable_percpu_irq,
> +				 &irq, 1);
>  	} else {
>  		for (i = 0; i < irqs; ++i) {
>  			int cpu = i;
This patch reduce the count call cpu_pmu_enable/disable_percpu_irq. For
example, if I call
perf.android top --cpu 0
only cpus 0~3 will enable and disable.

But the original code is work too because reference count is right too.
We just enable the irq we do not want, but there is not side effects.

Anyway, this patch work.

I believe the really  wrong thing is we have to set interrupt-affinity
on device tree, but we also set interrupt-partition too. The information
is duplicated.

Thanks,
Huang Tao