| Message ID | 1641749107-31979-7-git-send-email-quic_mkshah@quicinc.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere, archived |
| Headers | show |
| Series | Add APSS RSC to Cluster power domain | expand |
On Sun, 9 Jan 2022 at 18:26, Maulik Shah <quic_mkshah@quicinc.com> wrote: > > From: Lina Iyer <ilina@codeaurora.org> > > RSC is part the CPU subsystem and powers off the CPU domains when all > the CPUs and no RPMH transactions are pending from any of the drivers. > The RSC needs to flush the 'sleep' and 'wake' votes that are critical > for saving power when all the CPUs are in idle. > > Let's make RSC part of the CPU PM domains, by attaching it to the > cluster power domain. Registering for PM domain notifications, RSC > driver can be notified that the last CPU is powering down. When the last > CPU is powering down the domain, let's flush the 'sleep' and 'wake' > votes that are stored in the data buffers into the hardware and also > write next wakeup in CONTROL_TCS. > > Signed-off-by: Lina Iyer <ilina@codeaurora.org> > Signed-off-by: Maulik Shah <quic_mkshah@quicinc.com> > --- > drivers/soc/qcom/rpmh-internal.h | 6 +++- > drivers/soc/qcom/rpmh-rsc.c | 60 ++++++++++++++++++++++++++++++++++++++-- > 2 files changed, 62 insertions(+), 4 deletions(-) > > diff --git a/drivers/soc/qcom/rpmh-internal.h b/drivers/soc/qcom/rpmh-internal.h > index 344ba68..32ac117 100644 > --- a/drivers/soc/qcom/rpmh-internal.h > +++ b/drivers/soc/qcom/rpmh-internal.h > @@ -97,7 +97,9 @@ struct rpmh_ctrlr { > * @rsc_pm: CPU PM notifier for controller. > * Used when solver mode is not present. > * @cpus_in_pm: Number of CPUs not in idle power collapse. > - * Used when solver mode is not present. > + * Used when solver mode and "power-domains" is not present. > + * @genpd_nb: PM Domain notifier for cluster genpd notifications. > + * @genpdb: PM Domain for cluster genpd. /s/genpdb/genpd > * @tcs: TCS groups. > * @tcs_in_use: S/W state of the TCS; only set for ACTIVE_ONLY > * transfers, but might show a sleep/wake TCS in use if > @@ -117,6 +119,8 @@ struct rsc_drv { > int id; > int num_tcs; > struct notifier_block rsc_pm; > + struct notifier_block genpd_nb; > + struct generic_pm_domain *genpd; > atomic_t cpus_in_pm; > struct tcs_group tcs[TCS_TYPE_NR]; > DECLARE_BITMAP(tcs_in_use, MAX_TCS_NR); > diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c > index 01c2f50c..5875ad5 100644 > --- a/drivers/soc/qcom/rpmh-rsc.c > +++ b/drivers/soc/qcom/rpmh-rsc.c > @@ -14,10 +14,13 @@ > #include <linux/kernel.h> > #include <linux/list.h> > #include <linux/module.h> > +#include <linux/notifier.h> > #include <linux/of.h> > #include <linux/of_irq.h> > #include <linux/of_platform.h> > #include <linux/platform_device.h> > +#include <linux/pm_domain.h> > +#include <linux/pm_runtime.h> > #include <linux/slab.h> > #include <linux/spinlock.h> > #include <linux/wait.h> > @@ -834,6 +837,51 @@ static int rpmh_rsc_cpu_pm_callback(struct notifier_block *nfb, > return ret; > } > > +/** > + * rpmh_rsc_pd_callback() - Check if any of the AMCs are busy. > + * @nfb: Pointer to the genpd notifier block in struct rsc_drv. > + * @action: GENPD_NOTIFY_PRE_OFF, GENPD_NOTIFY_OFF, GENPD_NOTIFY_PRE_ON or GENPD_NOTIFY_ON. > + * @v: Unused > + * > + * This function is given to dev_pm_genpd_add_notifier() so we can be informed > + * about when cluster-pd is going down. When cluster go down we know no more active > + * transfers will be started so we write sleep/wake sets. This function gets > + * called from cpuidle code paths and also at system suspend time. > + * > + * If AMCs are not busy then writes cached sleep and wake messages to TCSes. > + * The firmware then takes care of triggering them when entering deepest low power modes. > + * > + * Return: > + * * NOTIFY_OK - success > + * * NOTIFY_BAD - failure > + */ > +static int rpmh_rsc_pd_callback(struct notifier_block *nfb, > + unsigned long action, void *v) > +{ > + struct rsc_drv *drv = container_of(nfb, struct rsc_drv, genpd_nb); > + > + /* We don't need to lock as domin on/off are serialized */ /s/domin/genpd > + if ((action == GENPD_NOTIFY_PRE_OFF) && > + (rpmh_rsc_ctrlr_is_busy(drv) || rpmh_flush(&drv->client))) > + return NOTIFY_BAD; > + > + return NOTIFY_OK; > +} > + > +static int rpmh_rsc_pd_attach(struct rsc_drv *drv, struct device *dev) > +{ > + int ret; > + > + pm_runtime_enable(dev); > + ret = dev_pm_domain_attach(dev, false); Unless I have missed something, this should not be needed. This is because it's a regular platform driver and we only have a single PM domain to attach for the rsc device. In this case, the platform bus is capable of managing the attach to the genpd. See platform_probe() in drivers/base/platform.c. > + if (ret) > + return ret; > + > + drv->genpd = pd_to_genpd(dev->pm_domain); I couldn't find where this pointer is being used later in the driver. In any case, you can probably use dev->pm_domain directly wherever needed instead. > + drv->genpd_nb.notifier_call = rpmh_rsc_pd_callback; > + return dev_pm_genpd_add_notifier(dev, &drv->genpd_nb); You should call pm_runtime_disable() in the error path. > +} > + > static int rpmh_probe_tcs_config(struct platform_device *pdev, > struct rsc_drv *drv, void __iomem *base) > { > @@ -963,7 +1011,7 @@ static int rpmh_rsc_probe(struct platform_device *pdev) > return ret; > > /* > - * CPU PM notification are not required for controllers that support > + * CPU PM/genpd notification are not required for controllers that support > * 'HW solver' mode where they can be in autonomous mode executing low > * power mode to power down. > */ > @@ -971,8 +1019,14 @@ static int rpmh_rsc_probe(struct platform_device *pdev) > solver_config &= DRV_HW_SOLVER_MASK << DRV_HW_SOLVER_SHIFT; > solver_config = solver_config >> DRV_HW_SOLVER_SHIFT; > if (!solver_config) { > - drv->rsc_pm.notifier_call = rpmh_rsc_cpu_pm_callback; > - cpu_pm_register_notifier(&drv->rsc_pm); > + if (of_find_property(dn, "power-domains", NULL)) { Rather than parsing the DT, I think it's better to check if "dev->pm_domain" has been assigned. As I indicated above, the platform bus manages the attach before the driver's ->probe() callback is invoked. > + ret = rpmh_rsc_pd_attach(drv, &pdev->dev); > + if (ret) > + return ret; > + } else { > + drv->rsc_pm.notifier_call = rpmh_rsc_cpu_pm_callback; > + cpu_pm_register_notifier(&drv->rsc_pm); > + } > } > > /* Enable the active TCS to send requests immediately */ Beyond this point, you need to call the below to manage the error path correctly: dev_pm_genpd_remove_notifier() pm_runtime_disable() > -- > 2.7.4 > Kind regards Uffe
diff --git a/drivers/soc/qcom/rpmh-internal.h b/drivers/soc/qcom/rpmh-internal.h index 344ba68..32ac117 100644 --- a/drivers/soc/qcom/rpmh-internal.h +++ b/drivers/soc/qcom/rpmh-internal.h @@ -97,7 +97,9 @@ struct rpmh_ctrlr { * @rsc_pm: CPU PM notifier for controller. * Used when solver mode is not present. * @cpus_in_pm: Number of CPUs not in idle power collapse. - * Used when solver mode is not present. + * Used when solver mode and "power-domains" is not present. + * @genpd_nb: PM Domain notifier for cluster genpd notifications. + * @genpdb: PM Domain for cluster genpd. * @tcs: TCS groups. * @tcs_in_use: S/W state of the TCS; only set for ACTIVE_ONLY * transfers, but might show a sleep/wake TCS in use if @@ -117,6 +119,8 @@ struct rsc_drv { int id; int num_tcs; struct notifier_block rsc_pm; + struct notifier_block genpd_nb; + struct generic_pm_domain *genpd; atomic_t cpus_in_pm; struct tcs_group tcs[TCS_TYPE_NR]; DECLARE_BITMAP(tcs_in_use, MAX_TCS_NR); diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c index 01c2f50c..5875ad5 100644 --- a/drivers/soc/qcom/rpmh-rsc.c +++ b/drivers/soc/qcom/rpmh-rsc.c @@ -14,10 +14,13 @@ #include <linux/kernel.h> #include <linux/list.h> #include <linux/module.h> +#include <linux/notifier.h> #include <linux/of.h> #include <linux/of_irq.h> #include <linux/of_platform.h> #include <linux/platform_device.h> +#include <linux/pm_domain.h> +#include <linux/pm_runtime.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/wait.h> @@ -834,6 +837,51 @@ static int rpmh_rsc_cpu_pm_callback(struct notifier_block *nfb, return ret; } +/** + * rpmh_rsc_pd_callback() - Check if any of the AMCs are busy. + * @nfb: Pointer to the genpd notifier block in struct rsc_drv. + * @action: GENPD_NOTIFY_PRE_OFF, GENPD_NOTIFY_OFF, GENPD_NOTIFY_PRE_ON or GENPD_NOTIFY_ON. + * @v: Unused + * + * This function is given to dev_pm_genpd_add_notifier() so we can be informed + * about when cluster-pd is going down. When cluster go down we know no more active + * transfers will be started so we write sleep/wake sets. This function gets + * called from cpuidle code paths and also at system suspend time. + * + * If AMCs are not busy then writes cached sleep and wake messages to TCSes. + * The firmware then takes care of triggering them when entering deepest low power modes. + * + * Return: + * * NOTIFY_OK - success + * * NOTIFY_BAD - failure + */ +static int rpmh_rsc_pd_callback(struct notifier_block *nfb, + unsigned long action, void *v) +{ + struct rsc_drv *drv = container_of(nfb, struct rsc_drv, genpd_nb); + + /* We don't need to lock as domin on/off are serialized */ + if ((action == GENPD_NOTIFY_PRE_OFF) && + (rpmh_rsc_ctrlr_is_busy(drv) || rpmh_flush(&drv->client))) + return NOTIFY_BAD; + + return NOTIFY_OK; +} + +static int rpmh_rsc_pd_attach(struct rsc_drv *drv, struct device *dev) +{ + int ret; + + pm_runtime_enable(dev); + ret = dev_pm_domain_attach(dev, false); + if (ret) + return ret; + + drv->genpd = pd_to_genpd(dev->pm_domain); + drv->genpd_nb.notifier_call = rpmh_rsc_pd_callback; + return dev_pm_genpd_add_notifier(dev, &drv->genpd_nb); +} + static int rpmh_probe_tcs_config(struct platform_device *pdev, struct rsc_drv *drv, void __iomem *base) { @@ -963,7 +1011,7 @@ static int rpmh_rsc_probe(struct platform_device *pdev) return ret; /* - * CPU PM notification are not required for controllers that support + * CPU PM/genpd notification are not required for controllers that support * 'HW solver' mode where they can be in autonomous mode executing low * power mode to power down. */ @@ -971,8 +1019,14 @@ static int rpmh_rsc_probe(struct platform_device *pdev) solver_config &= DRV_HW_SOLVER_MASK << DRV_HW_SOLVER_SHIFT; solver_config = solver_config >> DRV_HW_SOLVER_SHIFT; if (!solver_config) { - drv->rsc_pm.notifier_call = rpmh_rsc_cpu_pm_callback; - cpu_pm_register_notifier(&drv->rsc_pm); + if (of_find_property(dn, "power-domains", NULL)) { + ret = rpmh_rsc_pd_attach(drv, &pdev->dev); + if (ret) + return ret; + } else { + drv->rsc_pm.notifier_call = rpmh_rsc_cpu_pm_callback; + cpu_pm_register_notifier(&drv->rsc_pm); + } } /* Enable the active TCS to send requests immediately */