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PM / Domains: Add support for CPU devices to genpd

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To enable a CPU device to be attached to a PM domain managed by genpd,
make a few changes to it for convenience.

To be able to quickly find out what CPUs are attached to a genpd,
which typically becomes useful from a genpd governor as subsequent
changes are about to show, add a cpumask to struct generic_pm_domain
to be updated when a CPU device gets attached to the genpd containing
that cpumask. Also, propagate the cpumask changes upwards in the
domain hierarchy to the master PM domains. This way, the cpumask for
a genpd hierarchically reflects all CPUs attached to the topology
below it.

Finally, make this an opt-in feature, to avoid having to manage CPUs
and the cpumask for a genpd that don't need it. To that end, add
a new genpd configuration bit, GENPD_FLAG_CPU_DOMAIN.

Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Ulf Hansson 2019-03-27 15:35:46 +01:00 committed by Rafael J. Wysocki
parent 49a27e2790
commit eb594b7325
2 changed files with 77 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

65
drivers/base/power/domain.c
View file

@ -22,6 +22,7 @@
#include <linux/sched.h>
#include <linux/suspend.h>
#include <linux/export.h>
#include <linux/cpu.h>
#include "power.h"
@ -128,6 +129,7 @@ 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)
@ -1454,6 +1456,56 @@ 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)
{
@ -1475,6 +1527,7 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
genpd_lock(genpd);
genpd_set_cpumask(genpd, dev);
dev_pm_domain_set(dev, &genpd->domain);
genpd->device_count++;
@ -1532,6 +1585,7 @@ static int genpd_remove_device(struct generic_pm_domain *genpd,
genpd->device_count--;
genpd->max_off_time_changed = true;
genpd_clear_cpumask(genpd, dev);
dev_pm_domain_set(dev, NULL);
list_del_init(&pdd->list_node);
@ -1768,11 +1822,18 @@ 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 && genpd->state_count > 1) {
pr_warn("%s: no governor for states\n", genpd->name);
}
@ -1818,6 +1879,8 @@ 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_states)
genpd->free_states(genpd->states, genpd->state_count);

13
include/linux/pm_domain.h
View file

@ -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 */
@ -94,6 +106,7 @@ 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);
struct opp_table *opp_table; /* OPP table of the genpd */