[RFC 09/14] lib: sbi: Add PMU specific platform hooks

[Anup Patel]

> -----Original Message-----
> From: Atish Patra <atish.patra at wdc.com>
> Sent: 20 March 2021 03:43
> To: opensbi at lists.infradead.org
> Cc: Atish Patra <Atish.Patra at wdc.com>; Anup Patel <Anup.Patel at wdc.com>
> Subject: [RFC 09/14] lib: sbi: Add PMU specific platform hooks
> 
> A platform hook to initialize PMU allows platform vendors to provide their
> own mechanism to define pmu event-counter mappings in addition to the DT
> based approach.
> 
> Another platform hook that allows platform vendors customize the final
> mhpmevent value configuration.
> 
> Signed-off-by: Atish Patra <atish.patra at wdc.com>
> ---
>  include/sbi/sbi_platform.h | 38
> ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
> 
> diff --git a/include/sbi/sbi_platform.h b/include/sbi/sbi_platform.h index
> dadbc1e94e18..02773f672443 100644
> --- a/include/sbi/sbi_platform.h
> +++ b/include/sbi/sbi_platform.h
> @@ -97,6 +97,11 @@ struct sbi_platform_operations {
>  	/** Initialize (or populate) domains for the platform */
>  	int (*domains_init)(void);
> 
> +	/** Initialize hw performance counters */
> +	int (*pmu_init)(void);
> +
> +	uint64_t (*get_mhpmevent_value)(uint32_t event_idx, uint64_t
> data);

Rename get_mhpmevent_value() to pmu_xlate_to_mhpmevent() and
add one line comment about this callback.

> +
>  	/** Write a character to the platform console output */
>  	void (*console_putc)(char ch);
>  	/** Read a character from the platform console input */ @@ -514,6
> +519,39 @@ static inline int sbi_platform_domains_init(const struct
> sbi_platform *plat)
>  	return 0;
>  }
> 
> +/**
> + * Setup hw PMU events for the platform
> + *
> + * @param plat pointer to struct sbi_platform
> + *
> + * @return 0 on success and negative error code on failure  */ static
> +inline int sbi_platform_pmu_init(const struct sbi_platform *plat) {
> +	if (plat && sbi_platform_ops(plat)->pmu_init)
> +		return sbi_platform_ops(plat)->pmu_init();
> +	return 0;
> +}
> +
> +/**
> + * Get the value to be written in mhpmeventx for event_idx
> + *
> + * @param plat pointer to struct sbi_platform
> + * @param event_idx ID of the PMU event
> + * @param data Additional configuration data passed from supervisor
> +software
> + *
> + * @return expected value by the platform or 0 if platform doesn't know
> +about
> + * the event
> + */
> +static inline int sbi_platform_get_mhpmevent_value(const struct

Rename this as-per above suggestion.

> sbi_platform *plat,
> +						   uint32_t event_idx,
> uint64_t data) {
> +	if (plat && sbi_platform_ops(plat)->get_mhpmevent_value)
> +		return sbi_platform_ops(plat)-
> >get_mhpmevent_value(event_idx,
> +								   data);
> +	return 0;
> +}
> +
>  /**
>   * Write a character to the platform console output
>   *
> --
> 2.25.1

Regards,
Anup