[PATCH v3 5/5] powernv:cpufreq: Implement the driver->get() method

[Viresh Kumar]

On Thu, Mar 20, 2014 at 5:41 PM, Gautham R. Shenoy
<ego at linux.vnet.ibm.com> wrote:
> From: "Gautham R. Shenoy" <ego at linux.vnet.ibm.com>
>
> The current frequency of a cpu is reported through the sysfs file
> cpuinfo_cur_freq. This requires the driver to implement a
> "->get(unsigned int cpu)" method which will return the current
> operating frequency.
>
> Implement a function named powernv_cpufreq_get() which reads the local
> pstate from the PMSR and returns the corresponding frequency.
>
> Set the powernv_cpufreq_driver.get hook to powernv_cpufreq_get().
>
> Signed-off-by: Gautham R. Shenoy <ego at linux.vnet.ibm.com>
> ---
>  drivers/cpufreq/powernv-cpufreq.c | 38 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 38 insertions(+)

Please merge these fixups with the first patch which is creating the driver.
I understand that a different guy has created this patch and so wanted
to have a patch on his name but its really difficult to review this way.
Better add your signed-off in the first patch instead. Sending such changes
once the driver is mainlined looks fine.

> diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
> index 46bee8a..ef6ed8c 100644
> --- a/drivers/cpufreq/powernv-cpufreq.c
> +++ b/drivers/cpufreq/powernv-cpufreq.c
> @@ -206,6 +206,43 @@ static inline void set_pmspr(unsigned long sprn, unsigned long val)
>         BUG();
>  }
>
> +/*
> + * Computes the current frequency on this cpu
> + * and stores the result in *ret_freq.
> + */
> +static void powernv_read_cpu_freq(void *ret_freq)
> +{
> +       unsigned long pmspr_val;
> +       s8 local_pstate_id;
> +       int *cur_freq, freq, pstate_id;
> +
> +       cur_freq = (int *)ret_freq;

You don't need cur_freq variable at all..

> +       pmspr_val = get_pmspr(SPRN_PMSR);
> +
> +       /* The local pstate id corresponds bits 48..55 in the PMSR.
> +         * Note: Watch out for the sign! */
> +       local_pstate_id = (pmspr_val >> 48) & 0xFF;
> +       pstate_id = local_pstate_id;

similarly local_pstate_id

> +
> +       freq = pstate_id_to_freq(pstate_id);
> +       pr_debug("cpu %d pmsr %lx pstate_id %d frequency %d \n",
> +               smp_processor_id(), pmspr_val, pstate_id, freq);
> +       *cur_freq = freq;

Move above print here after a blank line. Also remove freq variable as
well and use *cur_freq directly.. And then you can rename it to freq as well.

> +}
> +
> +/*
> + * Returns the cpu frequency as reported by the firmware for 'cpu'.
> + * This value is reported through the sysfs file cpuinfo_cur_freq.
> + */
> +unsigned int powernv_cpufreq_get(unsigned int cpu)
> +{
> +       int ret_freq;
> +
> +       smp_call_function_any(cpu_sibling_mask(cpu), powernv_read_cpu_freq,
> +                       &ret_freq, 1);
> +       return ret_freq;
> +}
> +
>  static void set_pstate(void *pstate)
>  {
>         unsigned long val;
> @@ -297,6 +334,7 @@ static int powernv_cpufreq_target(struct cpufreq_policy *policy,
>  static struct cpufreq_driver powernv_cpufreq_driver = {
>         .verify         = powernv_cpufreq_verify,
>         .target         = powernv_cpufreq_target,
> +       .get            = powernv_cpufreq_get,
>         .init           = powernv_cpufreq_cpu_init,
>         .exit           = powernv_cpufreq_cpu_exit,
>         .name           = "powernv-cpufreq",
> --
> 1.8.3.1
>
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