linux-kernel - Re: [PATCH 1/5] perf/arm_cspmu: Export arm_cspmu_apmt

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <88a25a26-109d-b5cc-4bd2-776c3c2ba113@os.amperecomputing.com>
Date: Tue, 19 Aug 2025 13:16:01 -0700 (PDT)
From: Ilkka Koskinen <ilkka@...amperecomputing.com>
To: Besar Wicaksono <bwicaksono@...dia.com>
cc: will@...nel.org, linux-arm-kernel@...ts.infradead.org, 
    linux-kernel@...r.kernel.org, linux-tegra@...r.kernel.org, 
    suzuki.poulose@....com, robin.murphy@....com, ilkka@...amperecomputing.com, 
    mark.rutland@....com, treding@...dia.com, jonathanh@...dia.com, 
    vsethi@...dia.com, rwiley@...dia.com, sdonthineni@...dia.com
Subject: Re: [PATCH 1/5] perf/arm_cspmu: Export arm_cspmu_apmt_node


Hi Ben,

On Tue, 12 Aug 2025, Besar Wicaksono wrote:
> Make arm_cspmu_apmt_node API accessible to vendor driver.

I think I haven't seen the latest version of the spec. So, I'm curious,
what kind of information the table has that the vendor drivers needs to 
have access to it?

>
> Signed-off-by: Besar Wicaksono <bwicaksono@...dia.com>
> ---
> drivers/perf/arm_cspmu/arm_cspmu.c | 3 ++-
> drivers/perf/arm_cspmu/arm_cspmu.h | 4 ++++
> 2 files changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c b/drivers/perf/arm_cspmu/arm_cspmu.c
> index efa9b229e701..e4b98cfa606c 100644
> --- a/drivers/perf/arm_cspmu/arm_cspmu.c
> +++ b/drivers/perf/arm_cspmu/arm_cspmu.c
> @@ -70,12 +70,13 @@ static void arm_cspmu_set_ev_filter(struct arm_cspmu *cspmu,
> static void arm_cspmu_set_cc_filter(struct arm_cspmu *cspmu,
> 				    const struct perf_event *event);
>
> -static struct acpi_apmt_node *arm_cspmu_apmt_node(struct device *dev)
> +struct acpi_apmt_node *arm_cspmu_apmt_node(struct device *dev)
> {
> 	struct acpi_apmt_node **ptr = dev_get_platdata(dev);
>
> 	return ptr ? *ptr : NULL;
> }
> +EXPORT_SYMBOL_GPL(arm_cspmu_apmt_node);

Rather than exporting the function, wouldn't it be better to move it to 
arm_cspmu.h instead?

Cheers, Ilkka

>
> /*
>  * In CoreSight PMU architecture, all of the MMIO registers are 32-bit except
> diff --git a/drivers/perf/arm_cspmu/arm_cspmu.h b/drivers/perf/arm_cspmu/arm_cspmu.h
> index 19684b76bd96..36c1dcce33d6 100644
> --- a/drivers/perf/arm_cspmu/arm_cspmu.h
> +++ b/drivers/perf/arm_cspmu/arm_cspmu.h
> @@ -8,6 +8,7 @@
> #ifndef __ARM_CSPMU_H__
> #define __ARM_CSPMU_H__
>
> +#include <linux/acpi.h>
> #include <linux/bitfield.h>
> #include <linux/cpumask.h>
> #include <linux/device.h>
> @@ -222,4 +223,7 @@ int arm_cspmu_impl_register(const struct arm_cspmu_impl_match *impl_match);
> /* Unregister vendor backend. */
> void arm_cspmu_impl_unregister(const struct arm_cspmu_impl_match *impl_match);
>
> +/* Get ACPI APMT node. */
> +struct acpi_apmt_node *arm_cspmu_apmt_node(struct device *dev);
> +
> #endif /* __ARM_CSPMU_H__ */
> -- 
> 2.47.0
>
>