On Wed, Feb 24, 2021 at 07:58:39PM +0530, Madhavan Srinivasan wrote:
> Introduce code to support the checking of attr.config* for
> values which are reserved for a given platform.
> Performance Monitoring Unit (PMU) configuration registers
> have fileds that are reserved and specific values to bit fields
s/fileds/fields/
> as reserved. Writing a none zero values in these fields
Should the previous sentences say something like "required values
for specific bit fields" or "specific bit fields that are reserved"?
s/none zero/non-zero/
> or writing invalid value to bit fields will have unknown
> behaviours.
>
> Patch here add a generic call-back function "check_attr_config"
s/add/adds/ or "This patch adds ..." or just "Add ...".
> in "struct power_pmu", to be called in event_init to
> check for attr.config* values for a given platform.
> "check_attr_config" is valid only for raw event type.
>
> Suggested-by: Alexey Kardashevskiy <a...@ozlabs.ru>
> Signed-off-by: Madhavan Srinivasan <ma...@linux.ibm.com>
> ---
> arch/powerpc/include/asm/perf_event_server.h | 6 ++++++
> arch/powerpc/perf/core-book3s.c | 12 ++++++++++++
> 2 files changed, 18 insertions(+)
>
> diff --git a/arch/powerpc/include/asm/perf_event_server.h
> b/arch/powerpc/include/asm/perf_event_server.h
> index 00e7e671bb4b..dde97d7d9253 100644
> --- a/arch/powerpc/include/asm/perf_event_server.h
> +++ b/arch/powerpc/include/asm/perf_event_server.h
> @@ -67,6 +67,12 @@ struct power_pmu {
> * the pmu supports extended perf regs capability
> */
> int capabilities;
> + /*
> + * Function to check event code for values which are
> + * reserved. Function takes struct perf_event as input,
> + * since event code could be spread in attr.config*
> + */
> + int (*check_attr_config)(struct perf_event *ev);
> };
>
> /*
> diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
> index 6817331e22ff..679d67506299 100644
> --- a/arch/powerpc/perf/core-book3s.c
> +++ b/arch/powerpc/perf/core-book3s.c
> @@ -1958,6 +1958,18 @@ static int power_pmu_event_init(struct perf_event
> *event)
>
> if (ppmu->blacklist_ev && is_event_blacklisted(ev))
> return -EINVAL;
> + /*
> + * PMU config registers have fileds that are
> + * reserved and spacific values to bit fileds be reserved.
s/spacific/specific/
s/fileds/fields/
Same comment about "specific values to bit fields be reserved", and
rewording that to be more clear.
> + * This call-back will check the event code for same.
> + *
> + * Event type hardware and hw_cache will not value
> + * invalid values in the event code which is not true
> + * for raw event type.
I confess I don't understand what this means. (But it could be just me!)
> + */
> + if (ppmu->check_attr_config &&
> + ppmu->check_attr_config(event))
> + return -EINVAL;
> break;
> default:
> return -ENOENT;
> --
PC
