Re: [PATCH v2 2/3] drivers/perf: hisi: Add support for HiSilicon UC PMU driver

From: Yicong Yang
Date: Thu Jun 01 2023 - 02:54:06 EST


On 2023/5/31 23:59, Jonathan Cameron wrote:
> On Wed, 31 May 2023 18:46:24 +0800
> Junhao He <hejunhao3@xxxxxxxxxx> wrote:
>
> Hi Junhao,
>
> A few small comments inline.
>
>> On HiSilicon Hip09 platform, there is a UC (unified cache) module
>> on each chip SCCL (Super CPU Cluster). UC is a cache that provides
>> coherence between NUMA and UMA domains. It is located between L2
>> and Memory System. While PA uncore PMU model is the same as other
>> Hip09 PMU modules and many PMU events are supported.
>
> I don't follow what this sentence means. Normally you'd have
> While A, B is different..
>
>
>> Let's support
>> the PMU driver using the HiSilicon uncore PMU framework.
>>
>> * rd_req_en : rd_req_en is the abbreviation of read request tracetag enable
>> and allows user to count only read operations.
>> details are listed in the hisi-pmu document.
> Details are .. Also no need for the ine break
> and allows user to count only read operations. Details are listed
> in the hisi-pmu document at ....
>
>>
>> * srcid_en & srcid: allows user to filter statistics that come from
>
> Allows
> for consistency with the uring_channel description that follows.
>
>> specific CPU/ICL by configuration source ID.
>>
>> * uring_channel: Allows users to filter statistical information based on
>> the specified tx request uring channel.
>> uring_channel only supported events: [0x47 ~ 0x59].
>>
>> Signed-off-by: Junhao He <hejunhao3@xxxxxxxxxx>
>
>
>> diff --git a/drivers/perf/hisilicon/hisi_uncore_uc_pmu.c b/drivers/perf/hisilicon/hisi_uncore_uc_pmu.c
>> new file mode 100644
>> index 000000000000..d27f28584fd7
>> --- /dev/null
>> +++ b/drivers/perf/hisilicon/hisi_uncore_uc_pmu.c
>> @@ -0,0 +1,577 @@
> ...
>
>
>
>
>> +static int hisi_uc_pmu_init_data(struct platform_device *pdev,
>> + struct hisi_pmu *uc_pmu)
>> +{
>> + /*
>> + * Use SCCL (Super CPU Cluster) ID and CCL (CPU Cluster) ID to
>> + * identify the topology information of UC PMU devices in the chip.
>> + */
>
>>From patch description, I'd assume there is only one of these
> per sccl so why do we care about the cluster level or the sub-id?
> Perhaps that description is missleading?
>
>> + if (device_property_read_u32(&pdev->dev, "hisilicon,scl-id",
>> + &uc_pmu->sccl_id)) {
>> + dev_err(&pdev->dev, "Can not read uc sccl-id!\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (device_property_read_u32(&pdev->dev, "hisilicon,ccl-id",
>> + &uc_pmu->ccl_id)) {
>> + dev_err(&pdev->dev, "Can not read uc ccl-id!\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (device_property_read_u32(&pdev->dev, "hisilicon,sub-id",
>> + &uc_pmu->sub_id)) {
>> + dev_err(&pdev->dev, "Can not read sub-id!\n");
>> + return -EINVAL;
>> + }
>> +
>> + uc_pmu->base = devm_platform_ioremap_resource(pdev, 0);
>> + if (IS_ERR(uc_pmu->base)) {
>> + dev_err(&pdev->dev, "ioremap failed for uc_pmu resource\n");
>> + return PTR_ERR(uc_pmu->base);
>> + }
>> +
>> + uc_pmu->identifier = readl(uc_pmu->base + HISI_UC_VERSION_REG);
>> +
>> + return 0;
>> +}
>
>
>> +static struct platform_driver hisi_uc_pmu_driver = {
>> + .driver = {
>> + .name = "hisi_uc_pmu",
>> + .acpi_match_table = hisi_uc_pmu_acpi_match,
>> + /*
>> + * We have not worked out a safe bind/unbind process,
>> + * so this is not supported yet.
>
> If you can reference more info on this that would be great.
> Perhaps a thread talking about why?
>

We handle like this from this patch,
https://lore.kernel.org/linux-arm-kernel/1594975763-32966-1-git-send-email-liuqi115@xxxxxxxxxx/

>> + */
>> + .suppress_bind_attrs = true,
>> + },
>> + .probe = hisi_uc_pmu_probe,
>> +};
> .
>