2  * driver.c - driver support
4  * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
30  * __cpuidle_get_cpu_driver - return the cpuidle driver tied to a CPU.
42  * __cpuidle_unset_driver - unset per CPU driver variables.
43  * @drv: a valid pointer to a struct cpuidle_driver
46  * variable. If @drv is different from the registered driver, the corresponding
49 static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)  in __cpuidle_unset_driver()  argument
53 	for_each_cpu(cpu, drv->cpumask) {  in __cpuidle_unset_driver()
55 		if (drv != __cpuidle_get_cpu_driver(cpu))  in __cpuidle_unset_driver()
63  * __cpuidle_set_driver - set per CPU driver variables for the given driver.
64  * @drv: a valid pointer to a struct cpuidle_driver
66  * Returns 0 on success, -EBUSY if any CPU in the cpumask have a driver
67  * different from drv already.
69 static inline int __cpuidle_set_driver(struct cpuidle_driver *drv)  in __cpuidle_set_driver()  argument
73 	for_each_cpu(cpu, drv->cpumask) {  in __cpuidle_set_driver()
77 		if (old_drv && old_drv != drv)  in __cpuidle_set_driver()
78 			return -EBUSY;  in __cpuidle_set_driver()
81 	for_each_cpu(cpu, drv->cpumask)  in __cpuidle_set_driver()
82 		per_cpu(cpuidle_drivers, cpu) = drv;  in __cpuidle_set_driver()
84 	return 0;  in __cpuidle_set_driver()
92  * __cpuidle_get_cpu_driver - return the global cpuidle driver pointer.
104  * __cpuidle_set_driver - assign the global cpuidle driver variable.
105  * @drv: pointer to a struct cpuidle_driver object
107  * Returns 0 on success, -EBUSY if the driver is already registered.
109 static inline int __cpuidle_set_driver(struct cpuidle_driver *drv)  in __cpuidle_set_driver()  argument
112 		return -EBUSY;  in __cpuidle_set_driver()
114 	cpuidle_curr_driver = drv;  in __cpuidle_set_driver()
116 	return 0;  in __cpuidle_set_driver()
120  * __cpuidle_unset_driver - unset the global cpuidle driver variable.
121  * @drv: a pointer to a struct cpuidle_driver
123  * Reset the global cpuidle variable to NULL.  If @drv does not match the
126 static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)  in __cpuidle_unset_driver()  argument
128 	if (drv == cpuidle_curr_driver)  in __cpuidle_unset_driver()
135  * cpuidle_setup_broadcast_timer - enable/disable the broadcast timer on a cpu
152  * __cpuidle_driver_init - initialize the driver's internal data
153  * @drv: a valid pointer to a struct cpuidle_driver
155 static void __cpuidle_driver_init(struct cpuidle_driver *drv)  in __cpuidle_driver_init()  argument
164 	if (!drv->cpumask)  in __cpuidle_driver_init()
165 		drv->cpumask = (struct cpumask *)cpu_possible_mask;  in __cpuidle_driver_init()
167 	for (i = 0; i < drv->state_count; i++) {  in __cpuidle_driver_init()
168 		struct cpuidle_state *s = &drv->states[i];  in __cpuidle_driver_init()
175 		if (s->flags & CPUIDLE_FLAG_TIMER_STOP)  in __cpuidle_driver_init()
176 			drv->bctimer = 1;  in __cpuidle_driver_init()
183 		if (s->target_residency > 0)  in __cpuidle_driver_init()
184 			s->target_residency_ns = s->target_residency * NSEC_PER_USEC;  in __cpuidle_driver_init()
185 		else if (s->target_residency_ns < 0)  in __cpuidle_driver_init()
186 			s->target_residency_ns = 0;  in __cpuidle_driver_init()
188 			s->target_residency = div_u64(s->target_residency_ns, NSEC_PER_USEC);  in __cpuidle_driver_init()
190 		if (s->exit_latency > 0)  in __cpuidle_driver_init()
191 			s->exit_latency_ns = mul_u32_u32(s->exit_latency, NSEC_PER_USEC);  in __cpuidle_driver_init()
192 		else if (s->exit_latency_ns < 0)  in __cpuidle_driver_init()
193 			s->exit_latency_ns =  0;  in __cpuidle_driver_init()
195 			s->exit_latency = div_u64(s->exit_latency_ns, NSEC_PER_USEC);  in __cpuidle_driver_init()
201  * @drv: a valid pointer to a struct cpuidle_driver
207  * Returns 0 on success, a negative error code otherwise:
208  *  * -EINVAL if the driver pointer is NULL or no idle states are available
209  *  * -ENODEV if the cpuidle framework is disabled
210  *  * -EBUSY if the driver is already assigned to the global variable(s)
212 static int __cpuidle_register_driver(struct cpuidle_driver *drv)  in __cpuidle_register_driver()  argument
216 	if (!drv || !drv->state_count)  in __cpuidle_register_driver()
217 		return -EINVAL;  in __cpuidle_register_driver()
219 	ret = cpuidle_coupled_state_verify(drv);  in __cpuidle_register_driver()
224 		return -ENODEV;  in __cpuidle_register_driver()
226 	__cpuidle_driver_init(drv);  in __cpuidle_register_driver()
228 	ret = __cpuidle_set_driver(drv);  in __cpuidle_register_driver()
232 	if (drv->bctimer)  in __cpuidle_register_driver()
233 		on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer,  in __cpuidle_register_driver()
236 	return 0;  in __cpuidle_register_driver()
240  * __cpuidle_unregister_driver - unregister the driver
241  * @drv: a valid pointer to a struct cpuidle_driver
248 static void __cpuidle_unregister_driver(struct cpuidle_driver *drv)  in __cpuidle_unregister_driver()  argument
250 	if (drv->bctimer) {  in __cpuidle_unregister_driver()
251 		drv->bctimer = 0;  in __cpuidle_unregister_driver()
252 		on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer,  in __cpuidle_unregister_driver()
256 	__cpuidle_unset_driver(drv);  in __cpuidle_unregister_driver()
260  * cpuidle_register_driver - registers a driver
261  * @drv: a pointer to a valid struct cpuidle_driver
266  * Returns 0 on success, a negative error code (returned by
269 int cpuidle_register_driver(struct cpuidle_driver *drv)  in cpuidle_register_driver()  argument
275 	ret = __cpuidle_register_driver(drv);  in cpuidle_register_driver()
278 	if (!ret && !strlen(param_governor) && drv->governor &&  in cpuidle_register_driver()
279 	    (cpuidle_get_driver() == drv)) {  in cpuidle_register_driver()
281 		gov = cpuidle_find_governor(drv->governor);  in cpuidle_register_driver()
284 			if (cpuidle_switch_governor(gov) < 0)  in cpuidle_register_driver()
295  * cpuidle_unregister_driver - unregisters a driver
296  * @drv: a pointer to a valid struct cpuidle_driver
299  * to [un]register the driver from occuring at the same time.  @drv has to
302 void cpuidle_unregister_driver(struct cpuidle_driver *drv)  in cpuidle_unregister_driver()  argument
304 	bool enabled = (cpuidle_get_driver() == drv);  in cpuidle_unregister_driver()
307 	__cpuidle_unregister_driver(drv);  in cpuidle_unregister_driver()
323  * cpuidle_get_driver - return the driver tied to the current CPU.
329 	struct cpuidle_driver *drv;  in cpuidle_get_driver()  local
333 	drv = __cpuidle_get_cpu_driver(cpu);  in cpuidle_get_driver()
336 	return drv;  in cpuidle_get_driver()
341  * cpuidle_get_cpu_driver - return the driver registered for a CPU.
352 	return __cpuidle_get_cpu_driver(dev->cpu);  in cpuidle_get_cpu_driver()
357  * cpuidle_driver_state_disabled - Disable or enable an idle state
358  * @drv: cpuidle driver owning the state
362 void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx,  in cpuidle_driver_state_disabled()  argument
371 	if (!drv->cpumask) {  in cpuidle_driver_state_disabled()
372 		drv->states[idx].flags |= CPUIDLE_FLAG_UNUSABLE;  in cpuidle_driver_state_disabled()
376 	for_each_cpu(cpu, drv->cpumask) {  in cpuidle_driver_state_disabled()
383 			dev->states_usage[idx].disable |= CPUIDLE_STATE_DISABLED_BY_DRIVER;  in cpuidle_driver_state_disabled()
385 			dev->states_usage[idx].disable &= ~CPUIDLE_STATE_DISABLED_BY_DRIVER;  in cpuidle_driver_state_disabled()