Re: [PATCH v2 4/6] powernv:cpufreq: Create pstate_id_to_freq() helper

[Preeti U Murthy <preeti@linux.vnet.ibm.com>]

On 03/10/2014 04:40 PM, Gautham R. Shenoy wrote:
> From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
> 
> Create a helper routine that can return the cpu-frequency for the
> corresponding pstate_id.
> 
> Also, cache the values of the pstate_max, pstate_min and
> pstate_nominal and nr_pstates in a static structure so that they can
> be reused in the future to perform any validations.
> 
> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
> ---
>  drivers/cpufreq/powernv-cpufreq.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
> index 4c2e8ca..0ecd163 100644
> --- a/drivers/cpufreq/powernv-cpufreq.c
> +++ b/drivers/cpufreq/powernv-cpufreq.c
> @@ -39,6 +39,14 @@ static DEFINE_PER_CPU(struct mutex, freq_switch_lock);
>  static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1];
>  static int powernv_pstate_ids[POWERNV_MAX_PSTATES+1];
>  
> +struct powernv_pstate_info {
> +	int pstate_min_id;
> +	int pstate_max_id;
> +	int pstate_nominal_id;
> +	int nr_pstates;
> +};
> +static struct powernv_pstate_info powernv_pstate_info;
> +
>  /*
>   * Initialize the freq table based on data obtained
>   * from the firmware passed via device-tree
> @@ -112,9 +120,28 @@ static int init_powernv_pstates(void)
>  	for (i = 0; powernv_freqs[i].frequency != CPUFREQ_TABLE_END; i++)
>  		pr_debug("%d: %d\n", i, powernv_freqs[i].frequency);
>  
> +	powernv_pstate_info.pstate_min_id = pstate_min;
> +	powernv_pstate_info.pstate_max_id = pstate_max;
> +	powernv_pstate_info.pstate_nominal_id = pstate_nominal;
> +	powernv_pstate_info.nr_pstates = nr_pstates;
> +
>  	return 0;
>  }
>  
> +/**
> + * Returns the cpu frequency corresponding to the pstate_id.
> + */
> +static unsigned int pstate_id_to_freq(int pstate_id)
> +{
> +	int i;
> +
> +	i = powernv_pstate_info.pstate_max_id - pstate_id;
> +
> +	BUG_ON(i >= powernv_pstate_info.nr_pstates || i < 0);
> +	WARN_ON(powernv_pstate_ids[i] != pstate_id);
> +	return powernv_freqs[i].frequency;
> +}
> +
>  static struct freq_attr *powernv_cpu_freq_attr[] = {
>  	&cpufreq_freq_attr_scaling_available_freqs,
>  	NULL,
> 
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>