| Message ID | 20181129174700.16585-3-ulf.hansson@linaro.org (mailing list archive) |
|---|---|
| State | Deferred |
| Headers | show |
| Series | PM / Domains: Support hierarchical CPU arrangement (PSCI/ARM) | expand |
On 29/11/2018 18:46, Ulf Hansson wrote: > To enable a device belonging to a CPU to be attached to a PM domain managed > by genpd, let's do a few changes to it, as to make it convenient to manage > the specifics around CPUs. > > To be able to quickly find out what CPUs that are attached to a genpd, > which typically becomes useful from a genpd governor as following changes > is about to show, let's add a cpumask to the struct generic_pm_domain. At > the point when a CPU device gets attached to a genpd, let's update its > cpumask. Moreover, let's also propagate changes to the cpumask upwards in > the topology to the master PM domains. In this way, the cpumask for a genpd > hierarchically reflects all CPUs attached to the topology below it. > > Finally, let's make this an opt-in feature, to avoid having to manage CPUs > and the cpumask for a genpd that doesn't need it. For that reason, let's > add a new genpd configuration bit, GENPD_FLAG_CPU_DOMAIN. > > Cc: Lina Iyer <ilina@codeaurora.org> > Co-developed-by: Lina Iyer <lina.iyer@linaro.org> > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > --- > > Changes in v10: > - Don't allocate the cpumask when not used. > - Simplify the code that updates the cpumask. > - Document the GENPD_FLAG_CPU_DOMAIN. > > --- > drivers/base/power/domain.c | 66 ++++++++++++++++++++++++++++++++++++- > include/linux/pm_domain.h | 13 ++++++++ > 2 files changed, 78 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > index e27b91d36a2a..c3ff8e395308 100644 > --- a/drivers/base/power/domain.c > +++ b/drivers/base/power/domain.c > @@ -20,6 +20,7 @@ > #include <linux/sched.h> > #include <linux/suspend.h> > #include <linux/export.h> > +#include <linux/cpu.h> > > #include "power.h" > > @@ -126,6 +127,7 @@ static const struct genpd_lock_ops genpd_spin_ops = { > #define genpd_is_irq_safe(genpd) (genpd->flags & GENPD_FLAG_IRQ_SAFE) > #define genpd_is_always_on(genpd) (genpd->flags & GENPD_FLAG_ALWAYS_ON) > #define genpd_is_active_wakeup(genpd) (genpd->flags & GENPD_FLAG_ACTIVE_WAKEUP) > +#define genpd_is_cpu_domain(genpd) (genpd->flags & GENPD_FLAG_CPU_DOMAIN) > > static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev, > const struct generic_pm_domain *genpd) > @@ -1377,6 +1379,56 @@ static void genpd_free_dev_data(struct device *dev, > dev_pm_put_subsys_data(dev); > } > > +static void __genpd_update_cpumask(struct generic_pm_domain *genpd, > + int cpu, bool set, unsigned int depth) > +{ > + struct gpd_link *link; > + > + if (!genpd_is_cpu_domain(genpd)) > + return; With this test, we won't continue updating the cpumask for the other masters. Is it done on purpose ? > + list_for_each_entry(link, &genpd->slave_links, slave_node) { > + struct generic_pm_domain *master = link->master; > + > + genpd_lock_nested(master, depth + 1); > + __genpd_update_cpumask(master, cpu, set, depth + 1); > + genpd_unlock(master); > + } > + > + if (set) > + cpumask_set_cpu(cpu, genpd->cpus); > + else > + cpumask_clear_cpu(cpu, genpd->cpus); > +} > + > +static void genpd_update_cpumask(struct generic_pm_domain *genpd, > + struct device *dev, bool set) > +{ > + int cpu; > + > + if (!genpd_is_cpu_domain(genpd)) > + return; > + > + for_each_possible_cpu(cpu) { > + if (get_cpu_device(cpu) == dev) { > + __genpd_update_cpumask(genpd, cpu, set, 0); > + return; > + } > + } > +} > + > +static void genpd_set_cpumask(struct generic_pm_domain *genpd, > + struct device *dev) > +{ > + genpd_update_cpumask(genpd, dev, true); > +} > + > +static void genpd_clear_cpumask(struct generic_pm_domain *genpd, > + struct device *dev) > +{ > + genpd_update_cpumask(genpd, dev, false); > +} > + > static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, > struct gpd_timing_data *td) > { > @@ -1398,6 +1450,8 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, > if (ret) > goto out; > > + genpd_set_cpumask(genpd, dev); > + > dev_pm_domain_set(dev, &genpd->domain); > > genpd->device_count++; > @@ -1459,6 +1513,7 @@ static int genpd_remove_device(struct generic_pm_domain *genpd, > if (genpd->detach_dev) > genpd->detach_dev(genpd, dev); > > + genpd_clear_cpumask(genpd, dev); > dev_pm_domain_set(dev, NULL); > > list_del_init(&pdd->list_node); > @@ -1686,11 +1741,18 @@ int pm_genpd_init(struct generic_pm_domain *genpd, > if (genpd_is_always_on(genpd) && !genpd_status_on(genpd)) > return -EINVAL; > > + if (genpd_is_cpu_domain(genpd) && > + !zalloc_cpumask_var(&genpd->cpus, GFP_KERNEL)) > + return -ENOMEM; > + > /* Use only one "off" state if there were no states declared */ > if (genpd->state_count == 0) { > ret = genpd_set_default_power_state(genpd); > - if (ret) > + if (ret) { > + if (genpd_is_cpu_domain(genpd)) > + free_cpumask_var(genpd->cpus); > return ret; > + } > } else if (!gov) { > pr_warn("%s : no governor for states\n", genpd->name); > } > @@ -1736,6 +1798,8 @@ static int genpd_remove(struct generic_pm_domain *genpd) > list_del(&genpd->gpd_list_node); > genpd_unlock(genpd); > cancel_work_sync(&genpd->power_off_work); > + if (genpd_is_cpu_domain(genpd)) > + free_cpumask_var(genpd->cpus); > if (genpd->free_state) { > kfree(genpd->states); > genpd->states = NULL; > diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h > index f9e09bd4152c..5a4673605d22 100644 > --- a/include/linux/pm_domain.h > +++ b/include/linux/pm_domain.h > @@ -16,6 +16,7 @@ > #include <linux/of.h> > #include <linux/notifier.h> > #include <linux/spinlock.h> > +#include <linux/cpumask.h> > > /* > * Flags to control the behaviour of a genpd. > @@ -42,11 +43,22 @@ > * GENPD_FLAG_ACTIVE_WAKEUP: Instructs genpd to keep the PM domain powered > * on, in case any of its attached devices is used > * in the wakeup path to serve system wakeups. > + * > + * GENPD_FLAG_CPU_DOMAIN: Instructs genpd that it should expect to get > + * devices attached, which may belong to CPUs or > + * possibly have subdomains with CPUs attached. > + * This flag enables the genpd backend driver to > + * deploy idle power management support for CPUs > + * and groups of CPUs. Note that, the backend > + * driver must then comply with the so called, > + * last-man-standing algorithm, for the CPUs in the > + * PM domain. > */ > #define GENPD_FLAG_PM_CLK (1U << 0) > #define GENPD_FLAG_IRQ_SAFE (1U << 1) > #define GENPD_FLAG_ALWAYS_ON (1U << 2) > #define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3) > +#define GENPD_FLAG_CPU_DOMAIN (1U << 4) > > enum gpd_status { > GPD_STATE_ACTIVE = 0, /* PM domain is active */ > @@ -93,6 +105,7 @@ struct generic_pm_domain { > unsigned int suspended_count; /* System suspend device counter */ > unsigned int prepared_count; /* Suspend counter of prepared devices */ > unsigned int performance_state; /* Aggregated max performance state */ > + cpumask_var_t cpus; /* A cpumask of the attached CPUs */ > int (*power_off)(struct generic_pm_domain *domain); > int (*power_on)(struct generic_pm_domain *domain); > unsigned int (*opp_to_performance_state)(struct generic_pm_domain *genpd, >
On Wed, 19 Dec 2018 at 10:53, Daniel Lezcano <daniel.lezcano@linaro.org> wrote: > > On 29/11/2018 18:46, Ulf Hansson wrote: > > To enable a device belonging to a CPU to be attached to a PM domain managed > > by genpd, let's do a few changes to it, as to make it convenient to manage > > the specifics around CPUs. > > > > To be able to quickly find out what CPUs that are attached to a genpd, > > which typically becomes useful from a genpd governor as following changes > > is about to show, let's add a cpumask to the struct generic_pm_domain. At > > the point when a CPU device gets attached to a genpd, let's update its > > cpumask. Moreover, let's also propagate changes to the cpumask upwards in > > the topology to the master PM domains. In this way, the cpumask for a genpd > > hierarchically reflects all CPUs attached to the topology below it. > > > > Finally, let's make this an opt-in feature, to avoid having to manage CPUs > > and the cpumask for a genpd that doesn't need it. For that reason, let's > > add a new genpd configuration bit, GENPD_FLAG_CPU_DOMAIN. > > > > Cc: Lina Iyer <ilina@codeaurora.org> > > Co-developed-by: Lina Iyer <lina.iyer@linaro.org> > > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > > --- > > > > Changes in v10: > > - Don't allocate the cpumask when not used. > > - Simplify the code that updates the cpumask. > > - Document the GENPD_FLAG_CPU_DOMAIN. > > > > --- > > drivers/base/power/domain.c | 66 ++++++++++++++++++++++++++++++++++++- > > include/linux/pm_domain.h | 13 ++++++++ > > 2 files changed, 78 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > > index e27b91d36a2a..c3ff8e395308 100644 > > --- a/drivers/base/power/domain.c > > +++ b/drivers/base/power/domain.c > > @@ -20,6 +20,7 @@ > > #include <linux/sched.h> > > #include <linux/suspend.h> > > #include <linux/export.h> > > +#include <linux/cpu.h> > > > > #include "power.h" > > > > @@ -126,6 +127,7 @@ static const struct genpd_lock_ops genpd_spin_ops = { > > #define genpd_is_irq_safe(genpd) (genpd->flags & GENPD_FLAG_IRQ_SAFE) > > #define genpd_is_always_on(genpd) (genpd->flags & GENPD_FLAG_ALWAYS_ON) > > #define genpd_is_active_wakeup(genpd) (genpd->flags & GENPD_FLAG_ACTIVE_WAKEUP) > > +#define genpd_is_cpu_domain(genpd) (genpd->flags & GENPD_FLAG_CPU_DOMAIN) > > > > static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev, > > const struct generic_pm_domain *genpd) > > @@ -1377,6 +1379,56 @@ static void genpd_free_dev_data(struct device *dev, > > dev_pm_put_subsys_data(dev); > > } > > > > +static void __genpd_update_cpumask(struct generic_pm_domain *genpd, > > + int cpu, bool set, unsigned int depth) > > +{ > > + struct gpd_link *link; > > + > > + if (!genpd_is_cpu_domain(genpd)) > > + return; > > With this test, we won't continue updating the cpumask for the other > masters. Is it done on purpose ? Correct, and yes it's on purpose. We are not even allocating the cpumask for the genpd in question, unless it has the GENPD_FLAG_CPU_DOMAIN set. [...] Kind regards Uffe
On Wednesday, December 19, 2018 11:02:05 AM CET Ulf Hansson wrote: > On Wed, 19 Dec 2018 at 10:53, Daniel Lezcano <daniel.lezcano@linaro.org> wrote: > > > > On 29/11/2018 18:46, Ulf Hansson wrote: > > > To enable a device belonging to a CPU to be attached to a PM domain managed > > > by genpd, let's do a few changes to it, as to make it convenient to manage > > > the specifics around CPUs. > > > > > > To be able to quickly find out what CPUs that are attached to a genpd, > > > which typically becomes useful from a genpd governor as following changes > > > is about to show, let's add a cpumask to the struct generic_pm_domain. At > > > the point when a CPU device gets attached to a genpd, let's update its > > > cpumask. Moreover, let's also propagate changes to the cpumask upwards in > > > the topology to the master PM domains. In this way, the cpumask for a genpd > > > hierarchically reflects all CPUs attached to the topology below it. > > > > > > Finally, let's make this an opt-in feature, to avoid having to manage CPUs > > > and the cpumask for a genpd that doesn't need it. For that reason, let's > > > add a new genpd configuration bit, GENPD_FLAG_CPU_DOMAIN. > > > > > > Cc: Lina Iyer <ilina@codeaurora.org> > > > Co-developed-by: Lina Iyer <lina.iyer@linaro.org> > > > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > > > --- > > > > > > Changes in v10: > > > - Don't allocate the cpumask when not used. > > > - Simplify the code that updates the cpumask. > > > - Document the GENPD_FLAG_CPU_DOMAIN. > > > > > > --- > > > drivers/base/power/domain.c | 66 ++++++++++++++++++++++++++++++++++++- > > > include/linux/pm_domain.h | 13 ++++++++ > > > 2 files changed, 78 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > > > index e27b91d36a2a..c3ff8e395308 100644 > > > --- a/drivers/base/power/domain.c > > > +++ b/drivers/base/power/domain.c > > > @@ -20,6 +20,7 @@ > > > #include <linux/sched.h> > > > #include <linux/suspend.h> > > > #include <linux/export.h> > > > +#include <linux/cpu.h> > > > > > > #include "power.h" > > > > > > @@ -126,6 +127,7 @@ static const struct genpd_lock_ops genpd_spin_ops = { > > > #define genpd_is_irq_safe(genpd) (genpd->flags & GENPD_FLAG_IRQ_SAFE) > > > #define genpd_is_always_on(genpd) (genpd->flags & GENPD_FLAG_ALWAYS_ON) > > > #define genpd_is_active_wakeup(genpd) (genpd->flags & GENPD_FLAG_ACTIVE_WAKEUP) > > > +#define genpd_is_cpu_domain(genpd) (genpd->flags & GENPD_FLAG_CPU_DOMAIN) > > > > > > static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev, > > > const struct generic_pm_domain *genpd) > > > @@ -1377,6 +1379,56 @@ static void genpd_free_dev_data(struct device *dev, > > > dev_pm_put_subsys_data(dev); > > > } > > > > > > +static void __genpd_update_cpumask(struct generic_pm_domain *genpd, > > > + int cpu, bool set, unsigned int depth) > > > +{ > > > + struct gpd_link *link; > > > + > > > + if (!genpd_is_cpu_domain(genpd)) > > > + return; > > > > With this test, we won't continue updating the cpumask for the other > > masters. Is it done on purpose ? > > Correct, and yes it's on purpose. > > We are not even allocating the cpumask for the genpd in question, > unless it has the GENPD_FLAG_CPU_DOMAIN set. So this patch is generally fine by me. You can add my ACK to it when submitting it again, unless it is changed, so I know I've seen it already.
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index e27b91d36a2a..c3ff8e395308 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -20,6 +20,7 @@ #include <linux/sched.h> #include <linux/suspend.h> #include <linux/export.h> +#include <linux/cpu.h> #include "power.h" @@ -126,6 +127,7 @@ static const struct genpd_lock_ops genpd_spin_ops = { #define genpd_is_irq_safe(genpd) (genpd->flags & GENPD_FLAG_IRQ_SAFE) #define genpd_is_always_on(genpd) (genpd->flags & GENPD_FLAG_ALWAYS_ON) #define genpd_is_active_wakeup(genpd) (genpd->flags & GENPD_FLAG_ACTIVE_WAKEUP) +#define genpd_is_cpu_domain(genpd) (genpd->flags & GENPD_FLAG_CPU_DOMAIN) static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev, const struct generic_pm_domain *genpd) @@ -1377,6 +1379,56 @@ static void genpd_free_dev_data(struct device *dev, dev_pm_put_subsys_data(dev); } +static void __genpd_update_cpumask(struct generic_pm_domain *genpd, + int cpu, bool set, unsigned int depth) +{ + struct gpd_link *link; + + if (!genpd_is_cpu_domain(genpd)) + return; + + list_for_each_entry(link, &genpd->slave_links, slave_node) { + struct generic_pm_domain *master = link->master; + + genpd_lock_nested(master, depth + 1); + __genpd_update_cpumask(master, cpu, set, depth + 1); + genpd_unlock(master); + } + + if (set) + cpumask_set_cpu(cpu, genpd->cpus); + else + cpumask_clear_cpu(cpu, genpd->cpus); +} + +static void genpd_update_cpumask(struct generic_pm_domain *genpd, + struct device *dev, bool set) +{ + int cpu; + + if (!genpd_is_cpu_domain(genpd)) + return; + + for_each_possible_cpu(cpu) { + if (get_cpu_device(cpu) == dev) { + __genpd_update_cpumask(genpd, cpu, set, 0); + return; + } + } +} + +static void genpd_set_cpumask(struct generic_pm_domain *genpd, + struct device *dev) +{ + genpd_update_cpumask(genpd, dev, true); +} + +static void genpd_clear_cpumask(struct generic_pm_domain *genpd, + struct device *dev) +{ + genpd_update_cpumask(genpd, dev, false); +} + static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, struct gpd_timing_data *td) { @@ -1398,6 +1450,8 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, if (ret) goto out; + genpd_set_cpumask(genpd, dev); + dev_pm_domain_set(dev, &genpd->domain); genpd->device_count++; @@ -1459,6 +1513,7 @@ static int genpd_remove_device(struct generic_pm_domain *genpd, if (genpd->detach_dev) genpd->detach_dev(genpd, dev); + genpd_clear_cpumask(genpd, dev); dev_pm_domain_set(dev, NULL); list_del_init(&pdd->list_node); @@ -1686,11 +1741,18 @@ int pm_genpd_init(struct generic_pm_domain *genpd, if (genpd_is_always_on(genpd) && !genpd_status_on(genpd)) return -EINVAL; + if (genpd_is_cpu_domain(genpd) && + !zalloc_cpumask_var(&genpd->cpus, GFP_KERNEL)) + return -ENOMEM; + /* Use only one "off" state if there were no states declared */ if (genpd->state_count == 0) { ret = genpd_set_default_power_state(genpd); - if (ret) + if (ret) { + if (genpd_is_cpu_domain(genpd)) + free_cpumask_var(genpd->cpus); return ret; + } } else if (!gov) { pr_warn("%s : no governor for states\n", genpd->name); } @@ -1736,6 +1798,8 @@ static int genpd_remove(struct generic_pm_domain *genpd) list_del(&genpd->gpd_list_node); genpd_unlock(genpd); cancel_work_sync(&genpd->power_off_work); + if (genpd_is_cpu_domain(genpd)) + free_cpumask_var(genpd->cpus); if (genpd->free_state) { kfree(genpd->states); genpd->states = NULL; diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index f9e09bd4152c..5a4673605d22 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -16,6 +16,7 @@ #include <linux/of.h> #include <linux/notifier.h> #include <linux/spinlock.h> +#include <linux/cpumask.h> /* * Flags to control the behaviour of a genpd. @@ -42,11 +43,22 @@ * GENPD_FLAG_ACTIVE_WAKEUP: Instructs genpd to keep the PM domain powered * on, in case any of its attached devices is used * in the wakeup path to serve system wakeups. + * + * GENPD_FLAG_CPU_DOMAIN: Instructs genpd that it should expect to get + * devices attached, which may belong to CPUs or + * possibly have subdomains with CPUs attached. + * This flag enables the genpd backend driver to + * deploy idle power management support for CPUs + * and groups of CPUs. Note that, the backend + * driver must then comply with the so called, + * last-man-standing algorithm, for the CPUs in the + * PM domain. */ #define GENPD_FLAG_PM_CLK (1U << 0) #define GENPD_FLAG_IRQ_SAFE (1U << 1) #define GENPD_FLAG_ALWAYS_ON (1U << 2) #define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3) +#define GENPD_FLAG_CPU_DOMAIN (1U << 4) enum gpd_status { GPD_STATE_ACTIVE = 0, /* PM domain is active */ @@ -93,6 +105,7 @@ struct generic_pm_domain { unsigned int suspended_count; /* System suspend device counter */ unsigned int prepared_count; /* Suspend counter of prepared devices */ unsigned int performance_state; /* Aggregated max performance state */ + cpumask_var_t cpus; /* A cpumask of the attached CPUs */ int (*power_off)(struct generic_pm_domain *domain); int (*power_on)(struct generic_pm_domain *domain); unsigned int (*opp_to_performance_state)(struct generic_pm_domain *genpd,
To enable a device belonging to a CPU to be attached to a PM domain managed by genpd, let's do a few changes to it, as to make it convenient to manage the specifics around CPUs. To be able to quickly find out what CPUs that are attached to a genpd, which typically becomes useful from a genpd governor as following changes is about to show, let's add a cpumask to the struct generic_pm_domain. At the point when a CPU device gets attached to a genpd, let's update its cpumask. Moreover, let's also propagate changes to the cpumask upwards in the topology to the master PM domains. In this way, the cpumask for a genpd hierarchically reflects all CPUs attached to the topology below it. Finally, let's make this an opt-in feature, to avoid having to manage CPUs and the cpumask for a genpd that doesn't need it. For that reason, let's add a new genpd configuration bit, GENPD_FLAG_CPU_DOMAIN. Cc: Lina Iyer <ilina@codeaurora.org> Co-developed-by: Lina Iyer <lina.iyer@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> --- Changes in v10: - Don't allocate the cpumask when not used. - Simplify the code that updates the cpumask. - Document the GENPD_FLAG_CPU_DOMAIN. --- drivers/base/power/domain.c | 66 ++++++++++++++++++++++++++++++++++++- include/linux/pm_domain.h | 13 ++++++++ 2 files changed, 78 insertions(+), 1 deletion(-)