On Monday 10 Sep 2018 at 17:06:38 (+0100), Sudeep Holla wrote:
> On Mon, Sep 03, 2018 at 11:24:39AM +0100, Quentin Perret wrote:
> > The SCMI protocol can be used to get power estimates from firmware
> > corresponding to each performance state of a device. Although these power
> > costs are already managed by the SCMI firmware driver, they are not
> > exposed to any external subsystem yet.
> >
> > Fix this by adding a new get_power() interface to the exisiting perf_ops
> > defined for the SCMI protocol.
> >
> > Signed-off-by: Quentin Perret <quentin.per...@arm.com>
> > ---
> > v2: rebased on 4.19-rc2
> > ---
> > drivers/firmware/arm_scmi/perf.c | 28 ++++++++++++++++++++++++++++
> > include/linux/scmi_protocol.h | 4 ++++
> > 2 files changed, 32 insertions(+)
> >
> > diff --git a/drivers/firmware/arm_scmi/perf.c
> > b/drivers/firmware/arm_scmi/perf.c
> > index 721e6c57beae..272abd2cb3f0 100644
> > --- a/drivers/firmware/arm_scmi/perf.c
> > +++ b/drivers/firmware/arm_scmi/perf.c
> > @@ -421,6 +421,33 @@ static int scmi_dvfs_freq_get(const struct scmi_handle
> > *handle, u32 domain,
> > return ret;
> > }
> >
> > +static int scmi_dvfs_power_get(const struct scmi_handle *handle, u32
> > domain,
> > + unsigned long *freq, unsigned long *power)
>
> I feel the name "power_get" gives me feeling that it refers to instant
> power than the computed value. At least in scmi interface, freq_get
> provides current value of running frequency. I am not sure of the
> consistency in the naming in other subsystems.
Right, I see your point.
> Does it makes sense to name it "scmi_dvfs_est_power_get" as it actually
> refers to estimated power cost ?
"scmi_dvfs_est_power_get" sounds good to me.
> > +{
> > + struct scmi_perf_info *pi = handle->perf_priv;
> > + struct perf_dom_info *dom;
> > + unsigned long opp_freq;
> > + int idx, ret = -EINVAL;
> > + struct scmi_opp *opp;
> > +
> > + dom = pi->dom_info + domain;
> > + if (!dom)
> > + return -EIO;
> > +
> > + for (opp = dom->opp, idx = 0; idx < dom->opp_count; idx++, opp++) {
> > + opp_freq = opp->perf * dom->mult_factor;
> > + if (opp_freq < *freq)
> > + continue;
> > +
> > + *freq = opp_freq;
> > + *power = opp->power;
> > + ret = 0;
> > + break;
> > + }
> > +
> > + return ret;
> > +}
> > +
> > static struct scmi_perf_ops perf_ops = {
> > .limits_set = scmi_perf_limits_set,
> > .limits_get = scmi_perf_limits_get,
> > @@ -431,6 +458,7 @@ static struct scmi_perf_ops perf_ops = {
> > .device_opps_add = scmi_dvfs_device_opps_add,
> > .freq_set = scmi_dvfs_freq_set,
> > .freq_get = scmi_dvfs_freq_get,
> > + .power_get = scmi_dvfs_power_get,
>
> same here s/.power_get/.est_power_get/
>
> > };
> >
> > static int scmi_perf_protocol_init(struct scmi_handle *handle)
> > diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
> > index f4c9fc0fc755..2ecbd2c5a249 100644
> > --- a/include/linux/scmi_protocol.h
> > +++ b/include/linux/scmi_protocol.h
> > @@ -91,6 +91,8 @@ struct scmi_clk_ops {
> > * to sustained performance level mapping
> > * @freq_get: gets the frequency for a given device using sustained
> > frequency
> > * to sustained performance level mapping
> > + * @power_get: gets the power dissipated for a given performance domain at
> > a
>
> s/power dissipated/estimated power cost/
Ack for the two remarks above.
I'll spin a v3 soon.
Thanks!
Quentin
