2  * driver.c - driver support
4  * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
29  * __cpuidle_get_cpu_driver - return the cpuidle driver tied to a CPU.
41  * __cpuidle_unset_driver - unset per CPU driver variables.
42  * @drv: a valid pointer to a struct cpuidle_driver
45  * variable. If @drv is different from the registered driver, the corresponding
48 static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)  in __cpuidle_unset_driver()  argument
52 	for_each_cpu(cpu, drv->cpumask) {  in __cpuidle_unset_driver()
54 		if (drv != __cpuidle_get_cpu_driver(cpu))  in __cpuidle_unset_driver()
62  * __cpuidle_set_driver - set per CPU driver variables for the given driver.
63  * @drv: a valid pointer to a struct cpuidle_driver
65  * Returns 0 on success, -EBUSY if any CPU in the cpumask have a driver
66  * different from drv already.
68 static inline int __cpuidle_set_driver(struct cpuidle_driver *drv)  in __cpuidle_set_driver()  argument
72 	for_each_cpu(cpu, drv->cpumask) {  in __cpuidle_set_driver()
76 		if (old_drv && old_drv != drv)  in __cpuidle_set_driver()
77 			return -EBUSY;  in __cpuidle_set_driver()
80 	for_each_cpu(cpu, drv->cpumask)  in __cpuidle_set_driver()
81 		per_cpu(cpuidle_drivers, cpu) = drv;  in __cpuidle_set_driver()
91  * __cpuidle_get_cpu_driver - return the global cpuidle driver pointer.
103  * __cpuidle_set_driver - assign the global cpuidle driver variable.
104  * @drv: pointer to a struct cpuidle_driver object
106  * Returns 0 on success, -EBUSY if the driver is already registered.
108 static inline int __cpuidle_set_driver(struct cpuidle_driver *drv)  in __cpuidle_set_driver()  argument
111 		return -EBUSY;  in __cpuidle_set_driver()
113 	cpuidle_curr_driver = drv;  in __cpuidle_set_driver()
119  * __cpuidle_unset_driver - unset the global cpuidle driver variable.
120  * @drv: a pointer to a struct cpuidle_driver
122  * Reset the global cpuidle variable to NULL.  If @drv does not match the
125 static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)  in __cpuidle_unset_driver()  argument
127 	if (drv == cpuidle_curr_driver)  in __cpuidle_unset_driver()
134  * cpuidle_setup_broadcast_timer - enable/disable the broadcast timer on a cpu
151  * __cpuidle_driver_init - initialize the driver's internal data
152  * @drv: a valid pointer to a struct cpuidle_driver
154 static void __cpuidle_driver_init(struct cpuidle_driver *drv)  in __cpuidle_driver_init()  argument
163 	if (!drv->cpumask)  in __cpuidle_driver_init()
164 		drv->cpumask = (struct cpumask *)cpu_possible_mask;  in __cpuidle_driver_init()
166 	for (i = 0; i < drv->state_count; i++) {  in __cpuidle_driver_init()
167 		struct cpuidle_state *s = &drv->states[i];  in __cpuidle_driver_init()
174 		if (s->flags & CPUIDLE_FLAG_TIMER_STOP)  in __cpuidle_driver_init()
175 			drv->bctimer = 1;  in __cpuidle_driver_init()
182 		if (s->target_residency > 0)  in __cpuidle_driver_init()
183 			s->target_residency_ns = s->target_residency * NSEC_PER_USEC;  in __cpuidle_driver_init()
185 		if (s->exit_latency > 0)  in __cpuidle_driver_init()
186 			s->exit_latency_ns = s->exit_latency * NSEC_PER_USEC;  in __cpuidle_driver_init()
192  * @drv: a valid pointer to a struct cpuidle_driver
199  *  * -EINVAL if the driver pointer is NULL or no idle states are available
200  *  * -ENODEV if the cpuidle framework is disabled
201  *  * -EBUSY if the driver is already assigned to the global variable(s)
203 static int __cpuidle_register_driver(struct cpuidle_driver *drv)  in __cpuidle_register_driver()  argument
207 	if (!drv || !drv->state_count)  in __cpuidle_register_driver()
208 		return -EINVAL;  in __cpuidle_register_driver()
210 	ret = cpuidle_coupled_state_verify(drv);  in __cpuidle_register_driver()
215 		return -ENODEV;  in __cpuidle_register_driver()
217 	__cpuidle_driver_init(drv);  in __cpuidle_register_driver()
219 	ret = __cpuidle_set_driver(drv);  in __cpuidle_register_driver()
223 	if (drv->bctimer)  in __cpuidle_register_driver()
224 		on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer,  in __cpuidle_register_driver()
225 				 (void *)1, 1);  in __cpuidle_register_driver()
231  * __cpuidle_unregister_driver - unregister the driver
232  * @drv: a valid pointer to a struct cpuidle_driver
239 static void __cpuidle_unregister_driver(struct cpuidle_driver *drv)  in __cpuidle_unregister_driver()  argument
241 	if (drv->bctimer) {  in __cpuidle_unregister_driver()
242 		drv->bctimer = 0;  in __cpuidle_unregister_driver()
243 		on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer,  in __cpuidle_unregister_driver()
244 				 NULL, 1);  in __cpuidle_unregister_driver()
247 	__cpuidle_unset_driver(drv);  in __cpuidle_unregister_driver()
251  * cpuidle_register_driver - registers a driver
252  * @drv: a pointer to a valid struct cpuidle_driver
260 int cpuidle_register_driver(struct cpuidle_driver *drv)  in cpuidle_register_driver()  argument
266 	ret = __cpuidle_register_driver(drv);  in cpuidle_register_driver()
269 	if (!ret && !strlen(param_governor) && drv->governor &&  in cpuidle_register_driver()
270 	    (cpuidle_get_driver() == drv)) {  in cpuidle_register_driver()
272 		gov = cpuidle_find_governor(drv->governor);  in cpuidle_register_driver()
286  * cpuidle_unregister_driver - unregisters a driver
287  * @drv: a pointer to a valid struct cpuidle_driver
290  * to [un]register the driver from occuring at the same time.  @drv has to
293 void cpuidle_unregister_driver(struct cpuidle_driver *drv)  in cpuidle_unregister_driver()  argument
295 	bool enabled = (cpuidle_get_driver() == drv);  in cpuidle_unregister_driver()
298 	__cpuidle_unregister_driver(drv);  in cpuidle_unregister_driver()
314  * cpuidle_get_driver - return the driver tied to the current CPU.
320 	struct cpuidle_driver *drv;  in cpuidle_get_driver()  local
324 	drv = __cpuidle_get_cpu_driver(cpu);  in cpuidle_get_driver()
327 	return drv;  in cpuidle_get_driver()
332  * cpuidle_get_cpu_driver - return the driver registered for a CPU.
343 	return __cpuidle_get_cpu_driver(dev->cpu);  in cpuidle_get_cpu_driver()
348  * cpuidle_driver_state_disabled - Disable or enable an idle state
349  * @drv: cpuidle driver owning the state
353 void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx,  in cpuidle_driver_state_disabled()  argument
362 	if (!drv->cpumask) {  in cpuidle_driver_state_disabled()
363 		drv->states[idx].flags |= CPUIDLE_FLAG_UNUSABLE;  in cpuidle_driver_state_disabled()
367 	for_each_cpu(cpu, drv->cpumask) {  in cpuidle_driver_state_disabled()
374 			dev->states_usage[idx].disable |= CPUIDLE_STATE_DISABLED_BY_DRIVER;  in cpuidle_driver_state_disabled()
376 			dev->states_usage[idx].disable &= ~CPUIDLE_STATE_DISABLED_BY_DRIVER;  in cpuidle_driver_state_disabled()