| Message ID | 20240819-lpm-v6-10-constraints-pmdomain-v2-1-461325a6008f@baylibre.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere, archived |
| Headers | show |
| Series | pmdomain: ti_sci: collect and send low-power mode constraints | expand |
On Tue, 20 Aug 2024 at 02:00, Kevin Hilman <khilman@baylibre.com> wrote: > > For each device in a TI SCI PM domain, check whether the device has > any resume latency constraints set via per-device PM QoS. If > constraints are set, send them to DM via the new SCI constraints API. > > Checking for constraints happen for each device before system-wide > suspend (via ->suspend() hook.) > > An important detail here is that the PM domain driver inserts itself > into the path of both the ->suspend() and ->resume() hook path > of *all* devices in the PM domain. This allows generic PM domain code > to handle the constraint management and communication with TI SCI. > > Further, this allows device drivers to use existing PM QoS APIs to > add/update constraints. > > DM firmware clears constraints during its resume, so Linux has > to check/update/send constraints each time system suspends. > > Co-developed-by: Vibhore Vardhan <vibhore@ti.com> > Signed-off-by: Vibhore Vardhan <vibhore@ti.com> > Signed-off-by: Kevin Hilman <khilman@baylibre.com> > Signed-off-by: Dhruva Gole <d-gole@ti.com> > --- > drivers/pmdomain/ti/ti_sci_pm_domains.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 48 insertions(+) > > diff --git a/drivers/pmdomain/ti/ti_sci_pm_domains.c b/drivers/pmdomain/ti/ti_sci_pm_domains.c > index 1510d5ddae3d..963272fa387b 100644 > --- a/drivers/pmdomain/ti/ti_sci_pm_domains.c > +++ b/drivers/pmdomain/ti/ti_sci_pm_domains.c > @@ -13,6 +13,8 @@ > #include <linux/platform_device.h> > #include <linux/pm_domain.h> > #include <linux/slab.h> > +#include <linux/pm_qos.h> > +#include <linux/pm_runtime.h> > #include <linux/soc/ti/ti_sci_protocol.h> > #include <dt-bindings/soc/ti,sci_pm_domain.h> > > @@ -51,6 +53,29 @@ struct ti_sci_pm_domain { > > #define genpd_to_ti_sci_pd(gpd) container_of(gpd, struct ti_sci_pm_domain, pd) > > +static inline bool ti_sci_pd_is_valid_constraint(s32 val) > +{ > + return val != PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; > +} Should we perhaps add a generic helper function for this? Seems like a similar check is done at other places in the kernel too. > + > +static int ti_sci_pd_set_lat_constraint(struct device *dev, s32 val) > +{ Looks like you may want to turn this into a static void rather than static int. At least the caller, below, doesn't care about the return value. > + struct generic_pm_domain *genpd = pd_to_genpd(dev->pm_domain); > + struct ti_sci_pm_domain *pd = genpd_to_ti_sci_pd(genpd); > + const struct ti_sci_handle *ti_sci = pd->parent->ti_sci; > + int ret; > + > + ret = ti_sci->ops.pm_ops.set_latency_constraint(ti_sci, val, TISCI_MSG_CONSTRAINT_SET); > + if (ret) > + dev_err(dev, "ti_sci_pd: set latency constraint failed: ret=%d\n", > + ret); > + else > + dev_dbg(dev, "ti_sci_pd: ID:%d set latency constraint %d\n", > + pd->idx, val); > + > + return ret; > +} > + > /* > * ti_sci_pd_power_off(): genpd power down hook > * @domain: pointer to the powerdomain to power off > @@ -79,6 +104,22 @@ static int ti_sci_pd_power_on(struct generic_pm_domain *domain) > return ti_sci->ops.dev_ops.get_device(ti_sci, pd->idx); > } > > +static int ti_sci_pd_suspend(struct device *dev) > +{ > + int ret; > + s32 val; > + > + ret = pm_generic_suspend(dev); > + if (ret) > + return ret; > + > + val = dev_pm_qos_read_value(dev, DEV_PM_QOS_RESUME_LATENCY); > + if (ti_sci_pd_is_valid_constraint(val)) > + ti_sci_pd_set_lat_constraint(dev, val); > + > + return 0; > +} > + > /* > * ti_sci_pd_xlate(): translation service for TI SCI genpds > * @genpdspec: DT identification data for the genpd > @@ -188,6 +229,13 @@ static int ti_sci_pm_domain_probe(struct platform_device *pdev) > pd->pd.power_on = ti_sci_pd_power_on; > pd->idx = args.args[0]; > pd->parent = pd_provider; > + /* > + * If SCI constraint functions are present, then firmware > + * supports the constraints API. > + */ > + if (pd_provider->ti_sci->ops.pm_ops.set_device_constraint && > + pd_provider->ti_sci->ops.pm_ops.set_latency_constraint) > + pd->pd.domain.ops.suspend = ti_sci_pd_suspend; > > pm_genpd_init(&pd->pd, NULL, true); > > > -- > 2.46.0 > Other than the minor things above, this looks good to me. Kind regards Uffe
Ulf Hansson <ulf.hansson@linaro.org> writes: > On Tue, 20 Aug 2024 at 02:00, Kevin Hilman <khilman@baylibre.com> wrote: >> >> For each device in a TI SCI PM domain, check whether the device has >> any resume latency constraints set via per-device PM QoS. If >> constraints are set, send them to DM via the new SCI constraints API. >> >> Checking for constraints happen for each device before system-wide >> suspend (via ->suspend() hook.) >> >> An important detail here is that the PM domain driver inserts itself >> into the path of both the ->suspend() and ->resume() hook path >> of *all* devices in the PM domain. This allows generic PM domain code >> to handle the constraint management and communication with TI SCI. >> >> Further, this allows device drivers to use existing PM QoS APIs to >> add/update constraints. >> >> DM firmware clears constraints during its resume, so Linux has >> to check/update/send constraints each time system suspends. >> >> Co-developed-by: Vibhore Vardhan <vibhore@ti.com> >> Signed-off-by: Vibhore Vardhan <vibhore@ti.com> >> Signed-off-by: Kevin Hilman <khilman@baylibre.com> >> Signed-off-by: Dhruva Gole <d-gole@ti.com> >> --- >> drivers/pmdomain/ti/ti_sci_pm_domains.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 48 insertions(+) >> >> diff --git a/drivers/pmdomain/ti/ti_sci_pm_domains.c b/drivers/pmdomain/ti/ti_sci_pm_domains.c >> index 1510d5ddae3d..963272fa387b 100644 >> --- a/drivers/pmdomain/ti/ti_sci_pm_domains.c >> +++ b/drivers/pmdomain/ti/ti_sci_pm_domains.c >> @@ -13,6 +13,8 @@ >> #include <linux/platform_device.h> >> #include <linux/pm_domain.h> >> #include <linux/slab.h> >> +#include <linux/pm_qos.h> >> +#include <linux/pm_runtime.h> >> #include <linux/soc/ti/ti_sci_protocol.h> >> #include <dt-bindings/soc/ti,sci_pm_domain.h> >> >> @@ -51,6 +53,29 @@ struct ti_sci_pm_domain { >> >> #define genpd_to_ti_sci_pd(gpd) container_of(gpd, struct ti_sci_pm_domain, pd) >> >> +static inline bool ti_sci_pd_is_valid_constraint(s32 val) >> +{ >> + return val != PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; >> +} > > Should we perhaps add a generic helper function for this? Seems like a > similar check is done at other places in the kernel too. Maybe, but I don't see a lot of this same usage under drivers/*. But I'll have a closer look for a follow-up patch that might be able to make a common helper for this. >> + >> +static int ti_sci_pd_set_lat_constraint(struct device *dev, s32 val) >> +{ > > Looks like you may want to turn this into a static void rather than > static int. At least the caller, below, doesn't care about the return > value. Yup, OK. >> + struct generic_pm_domain *genpd = pd_to_genpd(dev->pm_domain); >> + struct ti_sci_pm_domain *pd = genpd_to_ti_sci_pd(genpd); >> + const struct ti_sci_handle *ti_sci = pd->parent->ti_sci; >> + int ret; >> + >> + ret = ti_sci->ops.pm_ops.set_latency_constraint(ti_sci, val, TISCI_MSG_CONSTRAINT_SET); >> + if (ret) >> + dev_err(dev, "ti_sci_pd: set latency constraint failed: ret=%d\n", >> + ret); >> + else >> + dev_dbg(dev, "ti_sci_pd: ID:%d set latency constraint %d\n", >> + pd->idx, val); >> + >> + return ret; >> +} >> + >> /* >> * ti_sci_pd_power_off(): genpd power down hook >> * @domain: pointer to the powerdomain to power off >> @@ -79,6 +104,22 @@ static int ti_sci_pd_power_on(struct generic_pm_domain *domain) >> return ti_sci->ops.dev_ops.get_device(ti_sci, pd->idx); >> } >> >> +static int ti_sci_pd_suspend(struct device *dev) >> +{ >> + int ret; >> + s32 val; >> + >> + ret = pm_generic_suspend(dev); >> + if (ret) >> + return ret; >> + >> + val = dev_pm_qos_read_value(dev, DEV_PM_QOS_RESUME_LATENCY); >> + if (ti_sci_pd_is_valid_constraint(val)) >> + ti_sci_pd_set_lat_constraint(dev, val); >> + >> + return 0; >> +} >> + >> /* >> * ti_sci_pd_xlate(): translation service for TI SCI genpds >> * @genpdspec: DT identification data for the genpd >> @@ -188,6 +229,13 @@ static int ti_sci_pm_domain_probe(struct platform_device *pdev) >> pd->pd.power_on = ti_sci_pd_power_on; >> pd->idx = args.args[0]; >> pd->parent = pd_provider; >> + /* >> + * If SCI constraint functions are present, then firmware >> + * supports the constraints API. >> + */ >> + if (pd_provider->ti_sci->ops.pm_ops.set_device_constraint && >> + pd_provider->ti_sci->ops.pm_ops.set_latency_constraint) >> + pd->pd.domain.ops.suspend = ti_sci_pd_suspend; >> >> pm_genpd_init(&pd->pd, NULL, true); >> >> >> -- >> 2.46.0 >> > > Other than the minor things above, this looks good to me. Thanks for the review! Will spin a v3 shortly. Kevin
diff --git a/drivers/pmdomain/ti/ti_sci_pm_domains.c b/drivers/pmdomain/ti/ti_sci_pm_domains.c index 1510d5ddae3d..963272fa387b 100644 --- a/drivers/pmdomain/ti/ti_sci_pm_domains.c +++ b/drivers/pmdomain/ti/ti_sci_pm_domains.c @@ -13,6 +13,8 @@ #include <linux/platform_device.h> #include <linux/pm_domain.h> #include <linux/slab.h> +#include <linux/pm_qos.h> +#include <linux/pm_runtime.h> #include <linux/soc/ti/ti_sci_protocol.h> #include <dt-bindings/soc/ti,sci_pm_domain.h> @@ -51,6 +53,29 @@ struct ti_sci_pm_domain { #define genpd_to_ti_sci_pd(gpd) container_of(gpd, struct ti_sci_pm_domain, pd) +static inline bool ti_sci_pd_is_valid_constraint(s32 val) +{ + return val != PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; +} + +static int ti_sci_pd_set_lat_constraint(struct device *dev, s32 val) +{ + struct generic_pm_domain *genpd = pd_to_genpd(dev->pm_domain); + struct ti_sci_pm_domain *pd = genpd_to_ti_sci_pd(genpd); + const struct ti_sci_handle *ti_sci = pd->parent->ti_sci; + int ret; + + ret = ti_sci->ops.pm_ops.set_latency_constraint(ti_sci, val, TISCI_MSG_CONSTRAINT_SET); + if (ret) + dev_err(dev, "ti_sci_pd: set latency constraint failed: ret=%d\n", + ret); + else + dev_dbg(dev, "ti_sci_pd: ID:%d set latency constraint %d\n", + pd->idx, val); + + return ret; +} + /* * ti_sci_pd_power_off(): genpd power down hook * @domain: pointer to the powerdomain to power off @@ -79,6 +104,22 @@ static int ti_sci_pd_power_on(struct generic_pm_domain *domain) return ti_sci->ops.dev_ops.get_device(ti_sci, pd->idx); } +static int ti_sci_pd_suspend(struct device *dev) +{ + int ret; + s32 val; + + ret = pm_generic_suspend(dev); + if (ret) + return ret; + + val = dev_pm_qos_read_value(dev, DEV_PM_QOS_RESUME_LATENCY); + if (ti_sci_pd_is_valid_constraint(val)) + ti_sci_pd_set_lat_constraint(dev, val); + + return 0; +} + /* * ti_sci_pd_xlate(): translation service for TI SCI genpds * @genpdspec: DT identification data for the genpd @@ -188,6 +229,13 @@ static int ti_sci_pm_domain_probe(struct platform_device *pdev) pd->pd.power_on = ti_sci_pd_power_on; pd->idx = args.args[0]; pd->parent = pd_provider; + /* + * If SCI constraint functions are present, then firmware + * supports the constraints API. + */ + if (pd_provider->ti_sci->ops.pm_ops.set_device_constraint && + pd_provider->ti_sci->ops.pm_ops.set_latency_constraint) + pd->pd.domain.ops.suspend = ti_sci_pd_suspend; pm_genpd_init(&pd->pd, NULL, true);