Messages in this thread Patch in this message | | | From | Viresh Kumar <> | Subject | [PATCH V2 5/5] PM / Domains: Propagate performance state updates | Date | Mon, 26 Nov 2018 13:40:04 +0530 |
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This commit updates genpd core to start propagating performance state updates to master domains that have their set_performance_state() callback set.
A genpd handles two type of performance states now. The first one is the performance state requirement put on the genpd by the devices and sub-domains under it, which is already represented by genpd->performance_state. The second type, introduced in this commit, is the performance state requirement(s) put by the genpd on its master domain(s). There is a separate value required for each master that the genpd has and so a new field is added to the struct gpd_link (link->performance_state), which represents the link between a genpd and its master. The struct gpd_link also got another field prev_performance_state, which is used by genpd core as a temporary variable during transitions.
We need to propagate setting performance state while powering-on a genpd as well, as we ignore performance state requirements from sub-domains which are powered-off. For this reason _genpd_power_on() also received the additional parameter, depth, which is used for hierarchical locking within genpd.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- drivers/base/power/domain.c | 113 ++++++++++++++++++++++++++++++------ include/linux/pm_domain.h | 4 ++ 2 files changed, 98 insertions(+), 19 deletions(-)
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index d6b389a9f678..206e263abe90 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -239,24 +239,88 @@ static void genpd_update_accounting(struct generic_pm_domain *genpd) static inline void genpd_update_accounting(struct generic_pm_domain *genpd) {} #endif +static int _genpd_reeval_performance_state(struct generic_pm_domain *genpd, + unsigned int state, int depth); + static int _genpd_set_performance_state(struct generic_pm_domain *genpd, - unsigned int state) + unsigned int state, int depth) { + struct generic_pm_domain *master; + struct gpd_link *link; + unsigned int mstate; int ret; + /* Propagate to masters of genpd */ + list_for_each_entry(link, &genpd->slave_links, slave_node) { + master = link->master; + + if (!master->set_performance_state) + continue; + + if (unlikely(!state)) { + mstate = 0; + } else { + /* Find master's performance state */ + mstate = dev_pm_opp_xlate_performance_state(genpd->opp_table, + master->opp_table, state); + if (unlikely(!mstate)) { + ret = -EINVAL; + goto err; + } + } + + genpd_lock_nested(master, depth + 1); + + link->prev_performance_state = link->performance_state; + link->performance_state = mstate; + ret = _genpd_reeval_performance_state(master, mstate, depth + 1); + if (ret) + link->performance_state = link->prev_performance_state; + + genpd_unlock(master); + + if (ret) + goto err; + } + ret = genpd->set_performance_state(genpd, state); if (ret) - return ret; + goto err; genpd->performance_state = state; return 0; + +err: + /* Encountered an error, lets rollback */ + list_for_each_entry_continue_reverse(link, &genpd->slave_links, + slave_node) { + master = link->master; + + if (!master->set_performance_state) + continue; + + genpd_lock_nested(master, depth + 1); + + mstate = link->prev_performance_state; + link->performance_state = mstate; + + if (_genpd_reeval_performance_state(master, mstate, depth + 1)) { + pr_err("%s: Failed to roll back to %d performance state\n", + master->name, mstate); + } + + genpd_unlock(master); + } + + return ret; } static int _genpd_reeval_performance_state(struct generic_pm_domain *genpd, - unsigned int state) + unsigned int state, int depth) { struct generic_pm_domain_data *pd_data; struct pm_domain_data *pdd; + struct gpd_link *link; /* New requested state is same as Max requested state */ if (state == genpd->performance_state) @@ -274,18 +338,27 @@ static int _genpd_reeval_performance_state(struct generic_pm_domain *genpd, state = pd_data->performance_state; } - if (state == genpd->performance_state) - return 0; - /* - * We aren't propagating performance state changes of a subdomain to its - * masters as we don't have hardware that needs it. Over that, the - * performance states of subdomain and its masters may not have - * one-to-one mapping and would require additional information. We can - * get back to this once we have hardware that needs it. For that - * reason, we don't have to consider performance state of the subdomains - * of genpd here. + * Traverse all powered-on subdomains within the domain. This can be + * done without any additional locking as the link->performance_state + * field is protected by the master genpd->lock, which is already taken. + * + * Also note that link->performance_state (subdomain's performance state + * requirement to master domain) is different from + * link->slave->performance_state (current performance state requirement + * of the devices/sub-domains of the subdomain) and so can have a + * different value. */ + list_for_each_entry(link, &genpd->master_links, master_node) { + if (!genpd_status_on(link->slave)) + continue; + + if (link->performance_state > state) + state = link->performance_state; + } + + if (state == genpd->performance_state) + return 0; update_state: if (!genpd_status_on(genpd)) { @@ -293,7 +366,7 @@ static int _genpd_reeval_performance_state(struct generic_pm_domain *genpd, return 0; } - return _genpd_set_performance_state(genpd, state); + return _genpd_set_performance_state(genpd, state, depth); } /** @@ -337,7 +410,7 @@ int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state) prev = gpd_data->performance_state; gpd_data->performance_state = state; - ret = _genpd_reeval_performance_state(genpd, state); + ret = _genpd_reeval_performance_state(genpd, state, 0); if (ret) gpd_data->performance_state = prev; @@ -347,7 +420,8 @@ int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state) } EXPORT_SYMBOL_GPL(dev_pm_genpd_set_performance_state); -static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed) +static int +_genpd_power_on(struct generic_pm_domain *genpd, bool timed, int depth) { unsigned int state_idx = genpd->state_idx; ktime_t time_start; @@ -368,7 +442,8 @@ static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed) elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start)); if (unlikely(genpd->set_performance_state)) { - ret = genpd->set_performance_state(genpd, genpd->performance_state); + ret = _genpd_set_performance_state(genpd, + genpd->performance_state, depth); if (ret) { pr_warn("%s: Failed to set performance state %d (%d)\n", genpd->name, genpd->performance_state, ret); @@ -558,7 +633,7 @@ static int genpd_power_on(struct generic_pm_domain *genpd, unsigned int depth) } } - ret = _genpd_power_on(genpd, true); + ret = _genpd_power_on(genpd, true, depth); if (ret) goto err; @@ -963,7 +1038,7 @@ static void genpd_sync_power_on(struct generic_pm_domain *genpd, bool use_lock, genpd_unlock(link->master); } - _genpd_power_on(genpd, false); + _genpd_power_on(genpd, false, depth); genpd->status = GPD_STATE_ACTIVE; } diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index 9ad101362aef..dd364abb649a 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -136,6 +136,10 @@ struct gpd_link { struct list_head master_node; struct generic_pm_domain *slave; struct list_head slave_node; + + /* Sub-domain's per-master domain performance state */ + unsigned int performance_state; + unsigned int prev_performance_state; }; struct gpd_timing_data { -- 2.19.1.568.g152ad8e3369a
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