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

Huang, Tao
2016-04-25T09:49:07Z

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.

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

Thanks,
Huang Tao