Re: [PATCH v3 1/5] perf/arm_cspmu: Add arm_cspmu_acpi_dev_get

[Suzuki K Poulose]

On 30/09/2025 14:00, Besar Wicaksono wrote:
> > -----Original Message-----
> > From: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> > Sent: Tuesday, September 30, 2025 3:38 AM
> > To: Besar Wicaksono <bwicaksono@xxxxxxxxxx>; will@xxxxxxxxxx;
> > robin.murphy@xxxxxxx; ilkka@xxxxxxxxxxxxxxxxxxxxxx
> > Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-
> > tegra@xxxxxxxxxxxxxxx; mark.rutland@xxxxxxx; Thierry Reding
> > <treding@xxxxxxxxxx>; Jon Hunter <jonathanh@xxxxxxxxxx>; Vikram Sethi
> > <vsethi@xxxxxxxxxx>; Rich Wiley <rwiley@xxxxxxxxxx>; Shanker Donthineni
> > <sdonthineni@xxxxxxxxxx>
> > Subject: Re: [PATCH v3 1/5] perf/arm_cspmu: Add arm_cspmu_acpi_dev_get
> >
> > External email: Use caution opening links or attachments
> >
> >
> > On 30/09/2025 01:26, Besar Wicaksono wrote:
> > > Add interface to get ACPI device associated with the
> > > PMU. This ACPI device may contain additional properties
> > > not covered by the standard properties.
> > >
> > > Signed-off-by: Besar Wicaksono <bwicaksono@xxxxxxxxxx>
> >
> > Repeat: Where is the user ?
>
> I thought you were okay if the use case is on future (different) series.
>
> So, this is a heads up on what I will have in nvidia_cspmu when adding the
> new PMU support. Do you prefer it to be part of this series?

No, I recommended the opposite. Apologies, if that wasn't clear.
Add a helper only when there is a user.

Suzuki


> +static u32 nv_cspmu_get_inst_id(const struct arm_cspmu *cspmu)
>
> +{
>
> +     u32 inst_id;
>
> +     struct fwnode_handle *fwnode;
>
> +     struct acpi_device *adev;
>
> +
>
> +     inst_id = 0;
>
> +
>
> +     adev = arm_cspmu_acpi_dev_get(cspmu);
>
> +     if (!adev)
>
> +           return 0;
>
> +
>
> +     fwnode = acpi_fwnode_handle(adev);
>
> +     if (fwnode && fwnode_property_read_u32(fwnode, "instance_id", 
> &inst_id))
>
> +           kstrtou32(acpi_device_uid(adev), 0, &inst_id);
>
> +
>
> +     acpi_dev_put(adev);
>
> +     return inst_id;
>
> +}
>
> Thanks,
> Besar