Re: [PATCH v8 5/8] perf tool: Add support for HiSilicon PCIe Tune and Trace device driver

From: Jonathan Cameron via iommu <iommu@lists.linux-foundation.org>
To: Yicong Yang <yangyicong@hisilicon.com>
Cc: mark.rutland@arm.com, prime.zeng@huawei.com,
	alexander.shishkin@linux.intel.com, linux-pci@vger.kernel.org,
	linuxarm@huawei.com, james.clark@arm.com, will@kernel.org,
	peterz@infradead.org, mingo@redhat.com, helgaas@kernel.org,
	liuqi115@huawei.com, suzuki.poulose@arm.com, acme@kernel.org,
	zhangshaokun@hisilicon.com, linux-arm-kernel@lists.infradead.org,
	mathieu.poirier@linaro.org, gregkh@linuxfoundation.org,
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
	iommu@lists.linux-foundation.org, leo.yan@linaro.org,
	robin.murphy@arm.com
Subject: Re: [PATCH v8 5/8] perf tool: Add support for HiSilicon PCIe Tune and Trace device driver
Date: Mon, 16 May 2022 15:20:22 +0100	[thread overview]
Message-ID: <20220516152022.00001ab9@Huawei.com> (raw)
In-Reply-To: <20220516125223.32012-6-yangyicong@hisilicon.com>

On Mon, 16 May 2022 20:52:20 +0800
Yicong Yang <yangyicong@hisilicon.com> wrote:

> From: Qi Liu <liuqi115@huawei.com>
> 
> HiSilicon PCIe tune and trace device (PTT) could dynamically tune
> the PCIe link's events, and trace the TLP headers).
> 
> This patch add support for PTT device in perf tool, so users could
> use 'perf record' to get TLP headers trace data.
> 
> Signed-off-by: Qi Liu <liuqi115@huawei.com>
> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>

One query inline.

> diff --git a/tools/perf/arch/arm/util/auxtrace.c b/tools/perf/arch/arm/util/auxtrace.c
> index 384c7cfda0fd..297fffedf45e 100644
> --- a/tools/perf/arch/arm/util/auxtrace.c
> +++ b/tools/perf/arch/arm/util/auxtrace.c

...

>  static struct perf_pmu *find_pmu_for_event(struct perf_pmu **pmus,
>  					   int pmu_nr, struct evsel *evsel)
>  {
> @@ -71,17 +120,21 @@ struct auxtrace_record
>  {
>  	struct perf_pmu	*cs_etm_pmu = NULL;
>  	struct perf_pmu **arm_spe_pmus = NULL;
> +	struct perf_pmu **hisi_ptt_pmus = NULL;
>  	struct evsel *evsel;
>  	struct perf_pmu *found_etm = NULL;
>  	struct perf_pmu *found_spe = NULL;
> +	struct perf_pmu *found_ptt = NULL;
>  	int auxtrace_event_cnt = 0;
>  	int nr_spes = 0;
> +	int nr_ptts = 0;
>  
>  	if (!evlist)
>  		return NULL;
>  
>  	cs_etm_pmu = perf_pmu__find(CORESIGHT_ETM_PMU_NAME);
>  	arm_spe_pmus = find_all_arm_spe_pmus(&nr_spes, err);
> +	hisi_ptt_pmus = find_all_hisi_ptt_pmus(&nr_ptts, err);
>  
>  	evlist__for_each_entry(evlist, evsel) {
>  		if (cs_etm_pmu && !found_etm)
> @@ -89,9 +142,13 @@ struct auxtrace_record
>  
>  		if (arm_spe_pmus && !found_spe)
>  			found_spe = find_pmu_for_event(arm_spe_pmus, nr_spes, evsel);
> +
> +		if (arm_spe_pmus && !found_spe)

		if (hisi_ptt_pmus && !found_ptt) ?

Otherwise, I'm not sure what the purpose of the checking against spe is.

> +			found_ptt = find_pmu_for_event(hisi_ptt_pmus, nr_ptts, evsel);
>  	}
>  
>  	free(arm_spe_pmus);
> +	free(hisi_ptt_pmus);
>  
>  	if (found_etm)
>  		auxtrace_event_cnt++;
> @@ -99,6 +156,9 @@ struct auxtrace_record
>  	if (found_spe)
>  		auxtrace_event_cnt++;
>  
> +	if (found_ptt)
> +		auxtrace_event_cnt++;
> +
>  	if (auxtrace_event_cnt > 1) {
>  		pr_err("Concurrent AUX trace operation not currently supported\n");
>  		*err = -EOPNOTSUPP;
> @@ -111,6 +171,9 @@ struct auxtrace_record
>  #if defined(__aarch64__)
>  	if (found_spe)
>  		return arm_spe_recording_init(err, found_spe);
> +
> +	if (found_ptt)
> +		return hisi_ptt_recording_init(err, found_ptt);
>  #endif
>  
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