| Message ID | 0c7ef1300e212f0ae06ccf10398f8c9453c064a5.1544782279.git.viresh.kumar@linaro.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | PM / Domains: Allow performance state propagation | expand |
On Fri, 14 Dec 2018 at 11:15, Viresh Kumar <viresh.kumar@linaro.org> wrote: > > Currently a genpd only handles the performance state requirements from > the devices under its control. This commit extends that to also handle > the performance state requirement(s) put on the master genpd by its > sub-domains. 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. > > On a call to dev_pm_genpd_set_performance_state(), the genpd core first > updates the performance state of the masters of the device's genpd and > then updates the performance state of the genpd. The masters do the same > and propagate performance state updates to their masters before updating > their own. The performance state transition from genpd to its master is > done with the help of dev_pm_opp_xlate_performance_state(), which looks > at the OPP tables of both the domains to translate the state. > Perfect! Thanks for clarifying these things in the changelog! > Tested-by: Rajendra Nayak <rnayak@codeaurora.org> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Kind regards Uffe > --- > drivers/base/power/domain.c | 93 ++++++++++++++++++++++++++++++++----- > include/linux/pm_domain.h | 4 ++ > 2 files changed, 86 insertions(+), 11 deletions(-) > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > index 808ba41b6580..611c0ccbad5f 100644 > --- a/drivers/base/power/domain.c > +++ b/drivers/base/power/domain.c > @@ -244,6 +244,7 @@ static int _genpd_reeval_performance_state(struct generic_pm_domain *genpd, > { > 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) > @@ -262,31 +263,101 @@ static int _genpd_reeval_performance_state(struct generic_pm_domain *genpd, > } > > /* > - * 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 sub-domains 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. > + * > + * Note that we also take vote from powered-off sub-domains into account > + * as the same is done for devices right now. > */ > + list_for_each_entry(link, &genpd->master_links, master_node) { > + if (link->performance_state > state) > + state = link->performance_state; > + } > + > return state; > } > > static int _genpd_set_performance_state(struct generic_pm_domain *genpd, > - unsigned int state) > + unsigned int state, int depth) > { > - int ret; > + struct generic_pm_domain *master; > + struct gpd_link *link; > + int master_state, ret; > > if (state == genpd->performance_state) > return 0; > > + /* Propagate to masters of genpd */ > + list_for_each_entry(link, &genpd->slave_links, slave_node) { > + master = link->master; > + > + if (!master->set_performance_state) > + continue; > + > + /* Find master's performance state */ > + ret = dev_pm_opp_xlate_performance_state(genpd->opp_table, > + master->opp_table, > + state); > + if (unlikely(ret < 0)) > + goto err; > + > + master_state = ret; > + > + genpd_lock_nested(master, depth + 1); > + > + link->prev_performance_state = link->performance_state; > + link->performance_state = master_state; > + master_state = _genpd_reeval_performance_state(master, > + master_state); > + ret = _genpd_set_performance_state(master, master_state, 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); > + > + master_state = link->prev_performance_state; > + link->performance_state = master_state; > + > + master_state = _genpd_reeval_performance_state(master, > + master_state); > + if (_genpd_set_performance_state(master, master_state, depth + 1)) { > + pr_err("%s: Failed to roll back to %d performance state\n", > + master->name, master_state); > + } > + > + genpd_unlock(master); > + } > + > + return ret; > } > > /** > @@ -331,7 +402,7 @@ int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state) > gpd_data->performance_state = state; > > state = _genpd_reeval_performance_state(genpd, state); > - ret = _genpd_set_performance_state(genpd, state); > + ret = _genpd_set_performance_state(genpd, state, 0); > if (ret) > gpd_data->performance_state = prev; > > 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 >
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 808ba41b6580..611c0ccbad5f 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -244,6 +244,7 @@ static int _genpd_reeval_performance_state(struct generic_pm_domain *genpd, { 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) @@ -262,31 +263,101 @@ static int _genpd_reeval_performance_state(struct generic_pm_domain *genpd, } /* - * 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 sub-domains 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. + * + * Note that we also take vote from powered-off sub-domains into account + * as the same is done for devices right now. */ + list_for_each_entry(link, &genpd->master_links, master_node) { + if (link->performance_state > state) + state = link->performance_state; + } + return state; } static int _genpd_set_performance_state(struct generic_pm_domain *genpd, - unsigned int state) + unsigned int state, int depth) { - int ret; + struct generic_pm_domain *master; + struct gpd_link *link; + int master_state, ret; if (state == genpd->performance_state) return 0; + /* Propagate to masters of genpd */ + list_for_each_entry(link, &genpd->slave_links, slave_node) { + master = link->master; + + if (!master->set_performance_state) + continue; + + /* Find master's performance state */ + ret = dev_pm_opp_xlate_performance_state(genpd->opp_table, + master->opp_table, + state); + if (unlikely(ret < 0)) + goto err; + + master_state = ret; + + genpd_lock_nested(master, depth + 1); + + link->prev_performance_state = link->performance_state; + link->performance_state = master_state; + master_state = _genpd_reeval_performance_state(master, + master_state); + ret = _genpd_set_performance_state(master, master_state, 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); + + master_state = link->prev_performance_state; + link->performance_state = master_state; + + master_state = _genpd_reeval_performance_state(master, + master_state); + if (_genpd_set_performance_state(master, master_state, depth + 1)) { + pr_err("%s: Failed to roll back to %d performance state\n", + master->name, master_state); + } + + genpd_unlock(master); + } + + return ret; } /** @@ -331,7 +402,7 @@ int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state) gpd_data->performance_state = state; state = _genpd_reeval_performance_state(genpd, state); - ret = _genpd_set_performance_state(genpd, state); + ret = _genpd_set_performance_state(genpd, state, 0); if (ret) gpd_data->performance_state = prev; 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 {