1 // SPDX-License-Identifier: GPL-2.0
3  * drivers/base/power/domain_governor.c - Governors for device PM domains.
20 	if (dev->power.subsys_data && dev->power.subsys_data->domain_data) {  in dev_update_qos_constraint()
21 		struct gpd_timing_data *td = dev_gpd_data(dev)->td;  in dev_update_qos_constraint()
24 		 * Only take suspend-time QoS constraints of devices into  in dev_update_qos_constraint()
30 		constraint_ns = td ? td->effective_constraint_ns :  in dev_update_qos_constraint()
34 		 * The child is not in a domain and there's no info on its  in dev_update_qos_constraint()
50  * default_suspend_ok - Default PM domain governor routine to suspend devices.
57 	struct gpd_timing_data *td = dev_gpd_data(dev)->td;  in default_suspend_ok()
63 	spin_lock_irqsave(&dev->power.lock, flags);  in default_suspend_ok()
65 	if (!td->constraint_changed) {  in default_suspend_ok()
66 		bool ret = td->cached_suspend_ok;  in default_suspend_ok()
68 		spin_unlock_irqrestore(&dev->power.lock, flags);  in default_suspend_ok()
71 	td->constraint_changed = false;  in default_suspend_ok()
72 	td->cached_suspend_ok = false;  in default_suspend_ok()
73 	td->effective_constraint_ns = 0;  in default_suspend_ok()
76 	spin_unlock_irqrestore(&dev->power.lock, flags);  in default_suspend_ok()
87 	if (!dev->power.ignore_children)  in default_suspend_ok()
93 		td->effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS;  in default_suspend_ok()
94 		td->cached_suspend_ok = true;  in default_suspend_ok()
98 		 * domain has a zero PM QoS constraint and it's better not to  in default_suspend_ok()
104 		constraint_ns -= td->suspend_latency_ns +  in default_suspend_ok()
105 				td->resume_latency_ns;  in default_suspend_ok()
114 		td->effective_constraint_ns = constraint_ns;  in default_suspend_ok()
115 		td->cached_suspend_ok = true;  in default_suspend_ok()
122 	return td->cached_suspend_ok;  in default_suspend_ok()
132 	if (!(genpd->flags & GENPD_FLAG_MIN_RESIDENCY))  in update_domain_next_wakeup()
138 	 * devices attached to this domain and from all the sub-domains.  in update_domain_next_wakeup()
140 	 * stale when we read that here. We will ignore to ensure the domain  in update_domain_next_wakeup()
141 	 * is able to enter its optimal idle state.  in update_domain_next_wakeup()
143 	list_for_each_entry(pdd, &genpd->dev_list, list_node) {  in update_domain_next_wakeup()
144 		next_wakeup = to_gpd_data(pdd)->td->next_wakeup;  in update_domain_next_wakeup()
150 	list_for_each_entry(link, &genpd->parent_links, parent_node) {  in update_domain_next_wakeup()
151 		struct genpd_governor_data *cgd = link->child->gd;  in update_domain_next_wakeup()
153 		next_wakeup = cgd ? cgd->next_wakeup : KTIME_MAX;  in update_domain_next_wakeup()
159 	genpd->gd->next_wakeup = domain_wakeup;  in update_domain_next_wakeup()
165 	ktime_t domain_wakeup = genpd->gd->next_wakeup;  in next_wakeup_allows_state()
168 	min_sleep_ns = genpd->states[state].power_off_latency_ns +  in next_wakeup_allows_state()
169 		       genpd->states[state].residency_ns;  in next_wakeup_allows_state()
185 	off_on_time_ns = genpd->states[state].power_off_latency_ns +  in __default_power_down_ok()
186 		genpd->states[state].power_on_latency_ns;  in __default_power_down_ok()
188 	min_off_time_ns = -1;  in __default_power_down_ok()
194 	list_for_each_entry(link, &genpd->parent_links, parent_node) {  in __default_power_down_ok()
195 		struct genpd_governor_data *cgd = link->child->gd;  in __default_power_down_ok()
197 		s64 sd_max_off_ns = cgd ? cgd->max_off_time_ns : -1;  in __default_power_down_ok()
204 		 * the current domain to turn off and on (that's how much time  in __default_power_down_ok()
215 	 * Check if the devices in the domain can be off enough time.  in __default_power_down_ok()
217 	list_for_each_entry(pdd, &genpd->dev_list, list_node) {  in __default_power_down_ok()
223 		 * domain to turn off and on (that's how much time it will  in __default_power_down_ok()
226 		td = to_gpd_data(pdd)->td;  in __default_power_down_ok()
227 		constraint_ns = td->effective_constraint_ns;  in __default_power_down_ok()
230 		 * devices in the domain are suspended, so it must be positive.  in __default_power_down_ok()
244 	 * latency constraints, so the domain can spend arbitrary time in the  in __default_power_down_ok()
252 	 * time and the time needed to turn the domain on is the maximum  in __default_power_down_ok()
253 	 * theoretical time this domain can spend in the "off" state.  in __default_power_down_ok()
255 	genpd->gd->max_off_time_ns = min_off_time_ns -  in __default_power_down_ok()
256 		genpd->states[state].power_on_latency_ns;  in __default_power_down_ok()
261  * _default_power_down_ok - Default generic PM domain power off governor routine.
262  * @pd: PM domain to check.
265  * This routine must be executed under the PM domain's lock.
272 	struct genpd_governor_data *gd = genpd->gd;  in _default_power_down_ok()
273 	int state_idx = genpd->state_count - 1;  in _default_power_down_ok()
278 	 * to find when the domain would wakeup and do it for every device down  in _default_power_down_ok()
283 	if ((genpd->flags & GENPD_FLAG_MIN_RESIDENCY) && (gd->next_wakeup != KTIME_MAX)) {  in _default_power_down_ok()
284 		/* Let's find out the deepest domain idle state, the devices prefer */  in _default_power_down_ok()
287 				gd->max_off_time_changed = true;  in _default_power_down_ok()
290 			state_idx--;  in _default_power_down_ok()
295 			gd->cached_power_down_ok = false;  in _default_power_down_ok()
300 	if (!gd->max_off_time_changed) {  in _default_power_down_ok()
301 		genpd->state_idx = gd->cached_power_down_state_idx;  in _default_power_down_ok()
302 		return gd->cached_power_down_ok;  in _default_power_down_ok()
311 	list_for_each_entry(link, &genpd->child_links, child_node) {  in _default_power_down_ok()
312 		struct genpd_governor_data *pgd = link->parent->gd;  in _default_power_down_ok()
315 			pgd->max_off_time_changed = true;  in _default_power_down_ok()
318 	gd->max_off_time_ns = -1;  in _default_power_down_ok()
319 	gd->max_off_time_changed = false;  in _default_power_down_ok()
320 	gd->cached_power_down_ok = true;  in _default_power_down_ok()
328 			gd->cached_power_down_ok = false;  in _default_power_down_ok()
331 		state_idx--;  in _default_power_down_ok()
335 	genpd->state_idx = state_idx;  in _default_power_down_ok()
336 	gd->cached_power_down_state_idx = genpd->state_idx;  in _default_power_down_ok()
337 	return gd->cached_power_down_ok;  in _default_power_down_ok()
359 	if (!(genpd->flags & GENPD_FLAG_CPU_DOMAIN))  in cpu_power_down_ok()
363 	 * Find the next wakeup for any of the online CPUs within the PM domain  in cpu_power_down_ok()
364 	 * and its subdomains. Note, we only need the genpd->cpus, as it already  in cpu_power_down_ok()
368 	for_each_cpu_and(cpu, genpd->cpus, cpu_online_mask) {  in cpu_power_down_ok()
371 			next_hrtimer = READ_ONCE(dev->next_hrtimer);  in cpu_power_down_ok()
377 	/* The minimum idle duration is from now - until the next wakeup. */  in cpu_power_down_ok()
383 	genpd->gd->next_hrtimer = domain_wakeup;  in cpu_power_down_ok()
386 	 * Find the deepest idle state that has its residency value satisfied  in cpu_power_down_ok()
390 	i = genpd->state_idx;  in cpu_power_down_ok()
392 		if (idle_duration_ns >= (genpd->states[i].residency_ns +  in cpu_power_down_ok()
393 		    genpd->states[i].power_off_latency_ns)) {  in cpu_power_down_ok()
394 			genpd->state_idx = i;  in cpu_power_down_ok()
397 	} while (--i >= 0);  in cpu_power_down_ok()
414  * pm_domain_always_on_gov - A governor implementing an always-on policy