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Message-ID: <e51863c0-496b-9630-e61a-2faa74356118@arm.com>
Date:   Wed, 16 Aug 2023 15:03:46 +0100
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Subject: Re: [PATCH v6 2/4] perf: arm_cspmu: Support implementation specific
 filters
Content-Language: en-US
To:     Ilkka Koskinen <ilkka@os.amperecomputing.com>,
        Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Besar Wicaksono <bwicaksono@nvidia.com>,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Jonathan Corbet <corbet@lwn.net>
Cc:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-doc@vger.kernel.org
References: <20230815063526.9022-1-ilkka@os.amperecomputing.com>
 <20230815063526.9022-3-ilkka@os.amperecomputing.com>
From:   Suzuki K Poulose <suzuki.poulose@arm.com>
In-Reply-To: <20230815063526.9022-3-ilkka@os.amperecomputing.com>
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Precedence: bulk

On 15/08/2023 07:35, Ilkka Koskinen wrote:
> ARM Coresight PMU architecture specification [1] defines PMEVTYPER and
> PMEVFILT* registers as optional in Chapter 2.1. Moreover, implementers may
> choose to use PMIMPDEF* registers (offset: 0xD80-> 0xDFF) to filter the
> events. Add support for those by adding implementation specific filter
> callback function.
> 
> [1] https://developer.arm.com/documentation/ihi0091/latest
> 
> Signed-off-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
> Reviewed-by: Besar Wicaksono <bwicaksono@nvidia.com>

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>

> ---
>   drivers/perf/arm_cspmu/arm_cspmu.c | 12 ++++++++----
>   drivers/perf/arm_cspmu/arm_cspmu.h |  3 +++
>   2 files changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c b/drivers/perf/arm_cspmu/arm_cspmu.c
> index 6387cbad7a7d..94f6856ec786 100644
> --- a/drivers/perf/arm_cspmu/arm_cspmu.c
> +++ b/drivers/perf/arm_cspmu/arm_cspmu.c
> @@ -116,6 +116,9 @@ static unsigned long arm_cspmu_cpuhp_state;
>   
>   static DEFINE_MUTEX(arm_cspmu_lock);
>   
> +static void arm_cspmu_set_ev_filter(struct arm_cspmu *cspmu,
> +				    struct hw_perf_event *hwc, u32 filter);
> +
>   static struct acpi_apmt_node *arm_cspmu_apmt_node(struct device *dev)
>   {
>   	return *(struct acpi_apmt_node **)dev_get_platdata(dev);
> @@ -450,6 +453,7 @@ static int arm_cspmu_init_impl_ops(struct arm_cspmu *cspmu)
>   	CHECK_DEFAULT_IMPL_OPS(impl_ops, event_type);
>   	CHECK_DEFAULT_IMPL_OPS(impl_ops, event_filter);
>   	CHECK_DEFAULT_IMPL_OPS(impl_ops, event_attr_is_visible);
> +	CHECK_DEFAULT_IMPL_OPS(impl_ops, set_ev_filter);
>   
>   	return 0;
>   }
> @@ -811,9 +815,9 @@ static inline void arm_cspmu_set_event(struct arm_cspmu *cspmu,
>   	writel(hwc->config, cspmu->base0 + offset);
>   }
>   
> -static inline void arm_cspmu_set_ev_filter(struct arm_cspmu *cspmu,
> -					   struct hw_perf_event *hwc,
> -					   u32 filter)
> +static void arm_cspmu_set_ev_filter(struct arm_cspmu *cspmu,
> +					struct hw_perf_event *hwc,
> +					u32 filter)
>   {
>   	u32 offset = PMEVFILTR + (4 * hwc->idx);
>   
> @@ -845,7 +849,7 @@ static void arm_cspmu_start(struct perf_event *event, int pmu_flags)
>   		arm_cspmu_set_cc_filter(cspmu, filter);
>   	} else {
>   		arm_cspmu_set_event(cspmu, hwc);
> -		arm_cspmu_set_ev_filter(cspmu, hwc, filter);
> +		cspmu->impl.ops.set_ev_filter(cspmu, hwc, filter);
>   	}
>   
>   	hwc->state = 0;
> diff --git a/drivers/perf/arm_cspmu/arm_cspmu.h b/drivers/perf/arm_cspmu/arm_cspmu.h
> index e5c6dff2ce7f..274ca3d10578 100644
> --- a/drivers/perf/arm_cspmu/arm_cspmu.h
> +++ b/drivers/perf/arm_cspmu/arm_cspmu.h
> @@ -104,6 +104,9 @@ struct arm_cspmu_impl_ops {
>   	u32 (*event_type)(const struct perf_event *event);
>   	/* Decode filter value from configs */
>   	u32 (*event_filter)(const struct perf_event *event);
> +	/* Set event filter */
> +	void (*set_ev_filter)(struct arm_cspmu *cspmu,
> +			      struct hw_perf_event *hwc, u32 filter);
>   	/* Hide/show unsupported events */
>   	umode_t (*event_attr_is_visible)(struct kobject *kobj,
>   					 struct attribute *attr, int unused);