Hi Mark,
Thanks for your further explanation.
On 2017/10/18 21:55, Mark Rutland wrote:
> On Wed, Oct 18, 2017 at 09:33:30PM +0800, Zhangshaokun wrote:
>> On 2017/10/17 23:16, Mark Rutland wrote:
>>> On Tue, Aug 22, 2017 at 04:07:54PM +0800, Shaokun Zhang wrote:
>>>> +static int hisi_l3c_pmu_init_data(struct platform_device *pdev,
>>>> + struct hisi_pmu *l3c_pmu)
>>>> +{
>>>> + unsigned long long id;
>>>> + struct resource *res;
>>>> + acpi_status status;
>>>> + int cpu;
>>>> +
>>>> + status = acpi_evaluate_integer(ACPI_HANDLE(&pdev->dev),
>>>> + "_UID", NULL, &id);
>>>> + if (ACPI_FAILURE(status))
>>>> + return -EINVAL;
>>>> +
>>>> + l3c_pmu->id = id;
>>>> +
>>>> + /*
>>>> + * Use the SCCL_ID and CCL_ID to identify the L3C PMU, while
>>>> + * SCCL_ID is in MPIDR[aff2] and CCL_ID is in MPIDR[aff1].
>>>> + */
>>>> + if (device_property_read_u32(&pdev->dev, "hisilicon,scl-id",
>>>> + &l3c_pmu->sccl_id)) {
>>>> + dev_err(&pdev->dev, "Can not read l3c sccl-id!\n");
>>>> + return -EINVAL;
>>>> + }
>>>> +
>>>> + if (device_property_read_u32(&pdev->dev, "hisilicon,ccl-id",
>>>> + &l3c_pmu->ccl_id)) {
>>>> + dev_err(&pdev->dev, "Can not read l3c ccl-id!\n");
>>>> + return -EINVAL;
>>>> + }
>>>> +
>>>> + /* Initialise the associated cpumask of the PMU */
>>>> + for_each_present_cpu(cpu)
>>>> + smp_call_function_single(cpu, hisi_l3c_pmu_set_cpumask_by_ccl,
>>>> + (void *)l3c_pmu, 1);
>
>>> Rather than a proble-time smp_call_function_single(), can you follow the
>>> qcom l2's approach of associating CPUs with a PMU instance in the
>>> notifier? That will work even if CPUs are brought online very late.
>>
>> A good guidance, but HHA and DDRC PMUs are different from L3C PMU, the former
>> share the same SCCL and the latter share the same SCCL and CCL. I will
>> try to deal with this difference in online notifier.
>
> FWIW, I think it makes sense for each PMU to have its own notifier
> (perhaps with some shared code that each calls to do the migration).
>
> I just want to avoid the smp_call_function_single() at probe time, as
> that doesn't work in some cases.
>
Got it, i shall update the hisi_pmu::associated_cpus only in online
and offline notifiers.
Thanks,
Shaokun
> Thanks,
> Mark.
>
> .
>
