1 // SPDX-License-Identifier: GPL-2.0-only
3  * arch/arm/common/mcpm_entry.c -- entry point for multi-cluster PM
6  * Copyright:   (C) 2012-2013  Linaro Limited
24  * see Documentation/arch/arm/cluster-pm-race-avoidance.rst.
34 static void __mcpm_cpu_going_down(unsigned int cpu, unsigned int cluster)  in __mcpm_cpu_going_down()  argument
36 	mcpm_sync.clusters[cluster].cpus[cpu].cpu = CPU_GOING_DOWN;  in __mcpm_cpu_going_down()
37 	sync_cache_w(&mcpm_sync.clusters[cluster].cpus[cpu].cpu);  in __mcpm_cpu_going_down()
42  *    cluster can be torn down without disrupting this CPU.
47 static void __mcpm_cpu_down(unsigned int cpu, unsigned int cluster)  in __mcpm_cpu_down()  argument
50 	mcpm_sync.clusters[cluster].cpus[cpu].cpu = CPU_DOWN;  in __mcpm_cpu_down()
51 	sync_cache_w(&mcpm_sync.clusters[cluster].cpus[cpu].cpu);  in __mcpm_cpu_down()
56  * __mcpm_outbound_leave_critical: Leave the cluster teardown critical section.
57  * @state: the final state of the cluster:
58  *     CLUSTER_UP: no destructive teardown was done and the cluster has been
60  *     CLUSTER_DOWN: the cluster has been torn-down, ready for power-off
63 static void __mcpm_outbound_leave_critical(unsigned int cluster, int state)  in __mcpm_outbound_leave_critical()  argument
66 	mcpm_sync.clusters[cluster].cluster = state;  in __mcpm_outbound_leave_critical()
67 	sync_cache_w(&mcpm_sync.clusters[cluster].cluster);  in __mcpm_outbound_leave_critical()
72  * __mcpm_outbound_enter_critical: Enter the cluster teardown critical section.
78  *         observed, or the cluster is already being set up;
80  *         cluster.
82 static bool __mcpm_outbound_enter_critical(unsigned int cpu, unsigned int cluster)  in __mcpm_outbound_enter_critical()  argument
85 	struct mcpm_sync_struct *c = &mcpm_sync.clusters[cluster];  in __mcpm_outbound_enter_critical()
87 	/* Warn inbound CPUs that the cluster is being torn down: */  in __mcpm_outbound_enter_critical()
88 	c->cluster = CLUSTER_GOING_DOWN;  in __mcpm_outbound_enter_critical()
89 	sync_cache_w(&c->cluster);  in __mcpm_outbound_enter_critical()
91 	/* Back out if the inbound cluster is already in the critical region: */  in __mcpm_outbound_enter_critical()
92 	sync_cache_r(&c->inbound);  in __mcpm_outbound_enter_critical()
93 	if (c->inbound == INBOUND_COMING_UP)  in __mcpm_outbound_enter_critical()
98 	 * teardown is complete on each CPU before tearing down the cluster.  in __mcpm_outbound_enter_critical()
101 	 * shouldn't be taking the cluster down at all: abort in that case.  in __mcpm_outbound_enter_critical()
103 	sync_cache_r(&c->cpus);  in __mcpm_outbound_enter_critical()
111 			cpustate = c->cpus[i].cpu;  in __mcpm_outbound_enter_critical()
116 			sync_cache_r(&c->cpus[i].cpu);  in __mcpm_outbound_enter_critical()
131 	__mcpm_outbound_leave_critical(cluster, CLUSTER_UP);  in __mcpm_outbound_enter_critical()
135 static int __mcpm_cluster_state(unsigned int cluster)  in __mcpm_cluster_state()  argument
137 	sync_cache_r(&mcpm_sync.clusters[cluster].cluster);  in __mcpm_cluster_state()
138 	return mcpm_sync.clusters[cluster].cluster;  in __mcpm_cluster_state()
143 void mcpm_set_entry_vector(unsigned cpu, unsigned cluster, void *ptr)  in mcpm_set_entry_vector()  argument
146 	mcpm_entry_vectors[cluster][cpu] = val;  in mcpm_set_entry_vector()
147 	sync_cache_w(&mcpm_entry_vectors[cluster][cpu]);  in mcpm_set_entry_vector()
152 void mcpm_set_early_poke(unsigned cpu, unsigned cluster,  in mcpm_set_early_poke()  argument
155 	unsigned long *poke = &mcpm_entry_early_pokes[cluster][cpu][0];  in mcpm_set_early_poke()
166 		return -EBUSY;  in mcpm_platform_register()
187 static inline bool mcpm_cluster_unused(unsigned int cluster)  in mcpm_cluster_unused()  argument
191 		cnt |= mcpm_cpu_use_count[cluster][i];  in mcpm_cluster_unused()
195 int mcpm_cpu_power_up(unsigned int cpu, unsigned int cluster)  in mcpm_cpu_power_up()  argument
200 	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);  in mcpm_cpu_power_up()
202 		return -EUNATCH; /* try not to shadow power_up errors */  in mcpm_cpu_power_up()
212 	cpu_is_down = !mcpm_cpu_use_count[cluster][cpu];  in mcpm_cpu_power_up()
213 	cluster_is_down = mcpm_cluster_unused(cluster);  in mcpm_cpu_power_up()
215 	mcpm_cpu_use_count[cluster][cpu]++;  in mcpm_cpu_power_up()
224 	BUG_ON(mcpm_cpu_use_count[cluster][cpu] != 1 &&  in mcpm_cpu_power_up()
225 	       mcpm_cpu_use_count[cluster][cpu] != 2);  in mcpm_cpu_power_up()
228 		ret = platform_ops->cluster_powerup(cluster);  in mcpm_cpu_power_up()
230 		ret = platform_ops->cpu_powerup(cpu, cluster);  in mcpm_cpu_power_up()
241 	unsigned int mpidr, cpu, cluster;  in mcpm_cpu_power_down()  local
247 	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);  in mcpm_cpu_power_down()
248 	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);  in mcpm_cpu_power_down()
255 	__mcpm_cpu_going_down(cpu, cluster);  in mcpm_cpu_power_down()
257 	BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);  in mcpm_cpu_power_down()
259 	mcpm_cpu_use_count[cluster][cpu]--;  in mcpm_cpu_power_down()
260 	BUG_ON(mcpm_cpu_use_count[cluster][cpu] != 0 &&  in mcpm_cpu_power_down()
261 	       mcpm_cpu_use_count[cluster][cpu] != 1);  in mcpm_cpu_power_down()
262 	cpu_going_down = !mcpm_cpu_use_count[cluster][cpu];  in mcpm_cpu_power_down()
263 	last_man = mcpm_cluster_unused(cluster);  in mcpm_cpu_power_down()
265 	if (last_man && __mcpm_outbound_enter_critical(cpu, cluster)) {  in mcpm_cpu_power_down()
266 		platform_ops->cpu_powerdown_prepare(cpu, cluster);  in mcpm_cpu_power_down()
267 		platform_ops->cluster_powerdown_prepare(cluster);  in mcpm_cpu_power_down()
269 		platform_ops->cluster_cache_disable();  in mcpm_cpu_power_down()
270 		__mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN);  in mcpm_cpu_power_down()
273 			platform_ops->cpu_powerdown_prepare(cpu, cluster);  in mcpm_cpu_power_down()
283 		platform_ops->cpu_cache_disable();  in mcpm_cpu_power_down()
286 	__mcpm_cpu_down(cpu, cluster);  in mcpm_cpu_power_down()
288 	/* Now we are prepared for power-down, do it: */  in mcpm_cpu_power_down()
297 	 * the required reset condition.  We must perform a re-entry in  in mcpm_cpu_power_down()
308 int mcpm_wait_for_cpu_powerdown(unsigned int cpu, unsigned int cluster)  in mcpm_wait_for_cpu_powerdown()  argument
312 	if (WARN_ON_ONCE(!platform_ops || !platform_ops->wait_for_powerdown))  in mcpm_wait_for_cpu_powerdown()
313 		return -EUNATCH;  in mcpm_wait_for_cpu_powerdown()
315 	ret = platform_ops->wait_for_powerdown(cpu, cluster);  in mcpm_wait_for_cpu_powerdown()
317 		pr_warn("%s: cpu %u, cluster %u failed to power down (%d)\n",  in mcpm_wait_for_cpu_powerdown()
318 			__func__, cpu, cluster, ret);  in mcpm_wait_for_cpu_powerdown()
329 	if (platform_ops->cpu_suspend_prepare) {  in mcpm_cpu_suspend()
332 		unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);   in mcpm_cpu_suspend()  local
334 		platform_ops->cpu_suspend_prepare(cpu, cluster);  in mcpm_cpu_suspend()
342 	unsigned int mpidr, cpu, cluster;  in mcpm_cpu_powered_up()  local
347 		return -EUNATCH;  in mcpm_cpu_powered_up()
351 	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);  in mcpm_cpu_powered_up()
355 	cpu_was_down = !mcpm_cpu_use_count[cluster][cpu];  in mcpm_cpu_powered_up()
356 	first_man = mcpm_cluster_unused(cluster);  in mcpm_cpu_powered_up()
358 	if (first_man && platform_ops->cluster_is_up)  in mcpm_cpu_powered_up()
359 		platform_ops->cluster_is_up(cluster);  in mcpm_cpu_powered_up()
361 		mcpm_cpu_use_count[cluster][cpu] = 1;  in mcpm_cpu_powered_up()
362 	if (platform_ops->cpu_is_up)  in mcpm_cpu_powered_up()
363 		platform_ops->cpu_is_up(cpu, cluster);  in mcpm_cpu_powered_up()
378 	unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);  in nocache_trampoline()  local
381 	mcpm_set_entry_vector(cpu, cluster, cpu_resume_no_hyp);  in nocache_trampoline()
384 	__mcpm_cpu_going_down(cpu, cluster);  in nocache_trampoline()
385 	BUG_ON(!__mcpm_outbound_enter_critical(cpu, cluster));  in nocache_trampoline()
387 	__mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN);  in nocache_trampoline()
388 	__mcpm_cpu_down(cpu, cluster);  in nocache_trampoline()
400 	 * We're going to soft-restart the current CPU through the  in mcpm_loopback()
401 	 * low-level MCPM code by leveraging the suspend/resume  in mcpm_loopback()
429 	BUG_ON((unsigned long)&mcpm_sync & (__CACHE_WRITEBACK_GRANULE - 1));  in mcpm_sync_init()
432 	 * Set initial CPU and cluster states.  in mcpm_sync_init()
433 	 * Only one cluster is assumed to be active at this point.  in mcpm_sync_init()
436 		mcpm_sync.clusters[i].cluster = CLUSTER_DOWN;  in mcpm_sync_init()
447 	mcpm_sync.clusters[this_cluster].cluster = CLUSTER_UP;  in mcpm_sync_init()