1 // SPDX-License-Identifier: GPL-2.0
3  *  cpuidle-powernv - idle state cpuidle driver.
4  *  Adapted from drivers/cpuidle/cpuidle-pseries
26  * Expose only those Hardware idle states via the cpuidle framework
32 	.name             = "powernv_idle",
58 	for (i = index + 1; i < drv->state_count; i++) {  in get_snooze_timeout()
59 		if (dev->states_usage[i].disable)  in get_snooze_timeout()
62 		return drv->states[i].target_residency * tb_ticks_per_usec;  in get_snooze_timeout()
79 	dev->poll_time_limit = false;  in snooze_loop()
90 			dev->poll_time_limit = true;  in snooze_loop()
156 		.name = "snooze",
196 	drv->state_count = 0;  in powernv_cpuidle_driver_init()
199 		/* Is the state not enabled? */  in powernv_cpuidle_driver_init()
203 		drv->states[drv->state_count] =	/* structure copy */  in powernv_cpuidle_driver_init()
206 		drv->state_count += 1;  in powernv_cpuidle_driver_init()
216 	 * drv->cpumask defaults to cpu_possible_mask in  in powernv_cpuidle_driver_init()
219 	 * cannot be hot-added later at run time.  in powernv_cpuidle_driver_init()
225 	drv->cpumask = (struct cpumask *)cpu_present_mask;  in powernv_cpuidle_driver_init()
230 static inline void add_powernv_state(int index, const char *name,  in add_powernv_state()  argument
239 	strscpy(powernv_states[index].name, name, CPUIDLE_NAME_LEN);  in add_powernv_state()
240 	strscpy(powernv_states[index].desc, name, CPUIDLE_NAME_LEN);  in add_powernv_state()
262 		pr_warn("cpuidle-powernv : Only Snooze is available\n");  in powernv_add_idle_states()
270 	 * Since snooze is used as first idle state, max idle states allowed is  in powernv_add_idle_states()
271 	 * CPUIDLE_STATE_MAX -1  in powernv_add_idle_states()
273 	if (nr_pnv_idle_states > CPUIDLE_STATE_MAX - 1) {  in powernv_add_idle_states()
274 		pr_warn("cpuidle-powernv: discovered idle states more than allowed");  in powernv_add_idle_states()
275 		dt_idle_states = CPUIDLE_STATE_MAX - 1;  in powernv_add_idle_states()
279 	 * If the idle states use stop instruction, probe for psscr values  in powernv_add_idle_states()
288 		struct pnv_idle_states_t *state = &pnv_idle_states[i];  in powernv_add_idle_states()  local
291 		 * Skip the platform idle state whose flag isn't in  in powernv_add_idle_states()
294 		if ((state->flags & supported_flags) != state->flags)  in powernv_add_idle_states()
297 		 * If an idle state has exit latency beyond  in powernv_add_idle_states()
299 		 * in cpu-idle.  in powernv_add_idle_states()
301 		if (state->latency_ns > POWERNV_THRESHOLD_LATENCY_NS)  in powernv_add_idle_states()
307 		exit_latency = DIV_ROUND_UP(state->latency_ns, 1000);  in powernv_add_idle_states()
308 		target_residency = DIV_ROUND_UP(state->residency_ns, 1000);  in powernv_add_idle_states()
310 		if (has_stop_states && !(state->valid))  in powernv_add_idle_states()
313 		if (state->flags & OPAL_PM_TIMEBASE_STOP)  in powernv_add_idle_states()
316 		if (state->flags & OPAL_PM_NAP_ENABLED) {  in powernv_add_idle_states()
317 			/* Add NAP state */  in powernv_add_idle_states()
322 			add_powernv_state(nr_idle_states, state->name,  in powernv_add_idle_states()
325 					  state->psscr_val,  in powernv_add_idle_states()
326 					  state->psscr_mask);  in powernv_add_idle_states()
334 		else if (state->flags & OPAL_PM_SLEEP_ENABLED ||  in powernv_add_idle_states()
335 			 state->flags & OPAL_PM_SLEEP_ENABLED_ER1) {  in powernv_add_idle_states()
336 			/* Add FASTSLEEP state */  in powernv_add_idle_states()
342 			add_powernv_state(nr_idle_states, state->name,  in powernv_add_idle_states()
345 					  state->psscr_val,  in powernv_add_idle_states()
346 					  state->psscr_mask);  in powernv_add_idle_states()
359  * Choose state table for shared versus dedicated partition
364 		return -ENODEV;  in powernv_idle_probe()
368 		/* Device tree can indicate more idle states */  in powernv_idle_probe()
374  		return -ENODEV;  in powernv_idle_probe()