1 // SPDX-License-Identifier: GPL-2.0
19  * The idle + run duration is specified via separate helpers and that allows
34  * It is up to the user of this framework to provide a lock for higher-level
51  * struct idle_inject_thread - task on/off switch structure
53  * @should_run: whether or not to run the task (for the smpboot kthread API)
61  * struct idle_inject_device - idle injection data
64  * @run_duration_us: duration of CPU run time to allow
80  * idle_inject_wakeup - Wake up idle injection threads
91 	for_each_cpu_and(cpu, to_cpumask(ii_dev->cpumask), cpu_online_mask) {  in idle_inject_wakeup()
93 		iit->should_run = 1;  in idle_inject_wakeup()
94 		wake_up_process(iit->tsk);  in idle_inject_wakeup()
99  * idle_inject_timer_fn - idle injection timer function
114 	duration_us = READ_ONCE(ii_dev->run_duration_us);  in idle_inject_timer_fn()
115 	duration_us += READ_ONCE(ii_dev->idle_duration_us);  in idle_inject_timer_fn()
125  * idle_inject_fn - idle injection work function
140 	 * Let the smpboot main loop know that the task should not run again.  in idle_inject_fn()
142 	iit->should_run = 0;  in idle_inject_fn()
144 	play_idle_precise(READ_ONCE(ii_dev->idle_duration_us) * NSEC_PER_USEC,  in idle_inject_fn()
145 			  READ_ONCE(ii_dev->latency_us) * NSEC_PER_USEC);  in idle_inject_fn()
149  * idle_inject_set_duration - idle and run duration update helper
150  * @run_duration_us: CPU run time to allow in microseconds
158 		WRITE_ONCE(ii_dev->run_duration_us, run_duration_us);  in idle_inject_set_duration()
159 		WRITE_ONCE(ii_dev->idle_duration_us, idle_duration_us);  in idle_inject_set_duration()
164  * idle_inject_get_duration - idle and run duration retrieval helper
165  * @run_duration_us: memory location to store the current CPU run time
172 	*run_duration_us = READ_ONCE(ii_dev->run_duration_us);  in idle_inject_get_duration()
173 	*idle_duration_us = READ_ONCE(ii_dev->idle_duration_us);  in idle_inject_get_duration()
177  * idle_inject_set_latency - set the maximum latency allowed
183 	WRITE_ONCE(ii_dev->latency_us, latency_us);  in idle_inject_set_latency()
187  * idle_inject_start - start idle injections
188  * @ii_dev: idle injection control device structure
194  * Return: -EINVAL if the CPU idle or CPU run time is not set or 0 on success.
198 	unsigned int idle_duration_us = READ_ONCE(ii_dev->idle_duration_us);  in idle_inject_start()
199 	unsigned int run_duration_us = READ_ONCE(ii_dev->run_duration_us);  in idle_inject_start()
202 		return -EINVAL;  in idle_inject_start()
205 		 cpumask_pr_args(to_cpumask(ii_dev->cpumask)));  in idle_inject_start()
209 	hrtimer_start(&ii_dev->timer,  in idle_inject_start()
218  * idle_inject_stop - stops idle injections
219  * @ii_dev: idle injection control device structure
234 		 cpumask_pr_args(to_cpumask(ii_dev->cpumask)));  in idle_inject_stop()
236 	hrtimer_cancel(&ii_dev->timer);  in idle_inject_stop()
253 	for_each_cpu(cpu, to_cpumask(ii_dev->cpumask)) {  in idle_inject_stop()
255 		iit->should_run = 0;  in idle_inject_stop()
257 		wait_task_inactive(iit->tsk, TASK_ANY);  in idle_inject_stop()
264  * idle_inject_setup - prepare the current task for idle injection
276  * idle_inject_should_run - function helper for the smpboot API
279  * Return: whether or not the thread can run.
286 	return iit->should_run;  in idle_inject_should_run()
290  * idle_inject_register - initialize idle injection on a set of CPUs
293  * This function creates an idle injection control device structure for the
297  * Return: NULL if memory allocation fails, idle injection control device
309 	cpumask_copy(to_cpumask(ii_dev->cpumask), cpumask);  in idle_inject_register()
310 	hrtimer_init(&ii_dev->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);  in idle_inject_register()
311 	ii_dev->timer.function = idle_inject_timer_fn;  in idle_inject_register()
312 	ii_dev->latency_us = UINT_MAX;  in idle_inject_register()
314 	for_each_cpu(cpu, to_cpumask(ii_dev->cpumask)) {  in idle_inject_register()
327 	for_each_cpu(cpu_rb, to_cpumask(ii_dev->cpumask)) {  in idle_inject_register()
339  * idle_inject_unregister - unregister idle injection control device
340  * @ii_dev: idle injection control device to unregister
342  * The function stops idle injection for the given control device,
352 	for_each_cpu(cpu, to_cpumask(ii_dev->cpumask))  in idle_inject_unregister()