linux-kernel - Re: [PATCH v4 4/6] perf: hisi: Add support for HiSilicon SoC HHA PMU driver

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Message-ID: <059720e3-e842-3e51-158d-3d36a2081bdd@hisilicon.com>
Date:   Thu, 17 Aug 2017 11:38:34 +0800
From:   Zhangshaokun <zhangshaokun@...ilicon.com>
To:     Mark Rutland <mark.rutland@....com>
CC:     <linux-doc@...r.kernel.org>, <will.deacon@....com>,
        <linuxarm@...wei.com>, <linux-kernel@...r.kernel.org>,
        <jonathan.cameron@...wei.com>,
        <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v4 4/6] perf: hisi: Add support for HiSilicon SoC HHA PMU
 driver

Hi Mark,

On 2017/8/15 19:05, Mark Rutland wrote:
> On Tue, Jul 25, 2017 at 08:10:40PM +0800, Shaokun Zhang wrote:
>> +/* HHA register definition */
>> +#define HHA_INT_MASK		0x0804
>> +#define HHA_INT_STATUS		0x0808
>> +#define HHA_INT_CLEAR		0x080C
>> +#define HHA_PERF_CTRL		0x1E00
>> +#define HHA_EVENT_CTRL		0x1E04
>> +#define HHA_EVENT_TYPE0		0x1E80
>> +#define HHA_CNT0_LOWER		0x1F00
>> +
>> +/* HHA has 16-counters and supports 0x50 events */
> 
> As with the L3C PMU, what exactly does this mean?
> 
> Does this mean event IDs 0-0x4f are valid?
> 

It is the same as L3C PMU and it is event IDs.

> [...]
> 
>> +static irqreturn_t hisi_hha_pmu_isr(int irq, void *dev_id)
>> +{
>> +	struct hisi_pmu *hha_pmu = dev_id;
>> +	struct perf_event *event;
>> +	unsigned long overflown;
>> +	u32 status;
>> +	int idx;
>> +
>> +	/* Read HHA_INT_STATUS register */
>> +	status = readl(hha_pmu->base + HHA_INT_STATUS);
>> +	if (!status)
>> +		return IRQ_NONE;
>> +	overflown = status;
> 
> No need for the u32 temporary here.
> 

Ok.

> [....]
> 
>> +static int hisi_hha_pmu_dev_probe(struct platform_device *pdev,
>> +				  struct hisi_pmu *hha_pmu)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	int ret;
>> +
>> +	ret = hisi_hha_pmu_init_data(pdev, hha_pmu);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/* Pick one core to use for cpumask attributes */
>> +	cpumask_set_cpu(smp_processor_id(), &hha_pmu->cpus);
>> +
> 
> Why does this not have the usual event migration callbacks, across CPUs
> in the same SCCL?
> 

Sorry we missed this. Shall add CPU hotplug callbacks and handle the cpumask
update and event migration.

>> +	ret = hisi_hha_pmu_init_irq(hha_pmu, pdev);
>> +	if (ret)
>> +		return ret;
>> +
>> +	hha_pmu->name = devm_kasprintf(dev, GFP_KERNEL, "hisi_hha%u_%u",
>> +				       hha_pmu->hha_uid, hha_pmu->sccl_id);
> 
> As on the doc patch, this should be hierarchical.
> 

Surely.

Thanks,
Shaokun

> Thanks,
> Mark
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 
> 

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