Re: [PATCH 7/8] xtensa: implement counting and sampling perf events

[Peter Zijlstra <peterz@infradead.org>]

On Mon, Jul 06, 2015 at 04:32:48PM +0300, Max Filippov wrote:
> +static int xtensa_pmu_event_init(struct perf_event *event)
> +{
> +	int ret;
> +
> +	switch (event->attr.type) {
> +	case PERF_TYPE_HARDWARE:
> +		if (event->attr.config >= ARRAY_SIZE(xtensa_hw_ctl) ||
> +		    xtensa_hw_ctl[event->attr.config] == 0)
> +			return -ENOENT;
> +		event->hw.config = xtensa_hw_ctl[event->attr.config];
> +		return 0;
> +
> +	case PERF_TYPE_HW_CACHE:
> +		ret = xtensa_pmu_cache_event(event->attr.config);
> +		if (ret < 0)
> +			return ret;
> +		event->hw.config = ret;
> +		return 0;
> +
> +	case PERF_TYPE_RAW:
> +		/* Not 'previous counter' select */
> +		if ((event->attr.config & XTENSA_PMU_PMCTRL_SELECT) ==
> +		    (1 << XTENSA_PMU_PMCTRL_SELECT_SHIFT))
> +			return -ENOENT;
> +		event->hw.config = (event->attr.config &
> +				    (XTENSA_PMU_PMCTRL_KRNLCNT |
> +				     XTENSA_PMU_PMCTRL_TRACELEVEL |
> +				     XTENSA_PMU_PMCTRL_SELECT |
> +				     XTENSA_PMU_PMCTRL_MASK)) |
> +			XTENSA_PMU_PMCTRL_INTEN;
> +		return 0;

Since this PMU implements TYPE_HARDWARE/TYPE_HW_CACHE/TYPE_RAW,
returning -ENOENT for those is wrong.

If the configuration is invalid, return -EINVAL.

> +
> +	default:
> +		return -ENOENT;
> +	}
> +}