blob: 2b519eee84d8ac7bb80e7374557769534970a320 [file] [log] [blame]
Nicolas Pitre81543a92012-10-19 20:48:50 -04001/*
2 * arch/arm/mach-vexpress/tc2_pm.c - TC2 power management support
3 *
4 * Created by: Nicolas Pitre, October 2012
5 * Copyright: (C) 2012 Linaro Limited
6 *
7 * Some portions of this file were originally written by Achin Gupta
8 * Copyright: (C) 2012 ARM Limited
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14
15#include <linux/init.h>
16#include <linux/kernel.h>
17#include <linux/spinlock.h>
18#include <linux/errno.h>
Lorenzo Pieralisi0b94e1b2013-02-05 11:09:16 +000019#include <linux/irqchip/arm-gic.h>
Nicolas Pitre81543a92012-10-19 20:48:50 -040020
21#include <asm/mcpm.h>
22#include <asm/proc-fns.h>
23#include <asm/cacheflush.h>
24#include <asm/cputype.h>
25#include <asm/cp15.h>
Achin Gupta58068c42012-12-17 00:15:00 +000026#include <asm/psci.h>
Nicolas Pitre81543a92012-10-19 20:48:50 -040027
28#include <mach/motherboard.h>
Achin Gupta922b78c2013-03-10 22:36:51 +000029#include <mach/tc2.h>
Nicolas Pitre81543a92012-10-19 20:48:50 -040030
31#include <linux/vexpress.h>
32#include <linux/arm-cci.h>
33
34/*
35 * We can't use regular spinlocks. In the switcher case, it is possible
36 * for an outbound CPU to call power_down() after its inbound counterpart
37 * is already live using the same logical CPU number which trips lockdep
38 * debugging.
39 */
40static arch_spinlock_t tc2_pm_lock = __ARCH_SPIN_LOCK_UNLOCKED;
41
Achin Gupta922b78c2013-03-10 22:36:51 +000042static int tc2_pm_use_count[TC2_MAX_CPUS][TC2_MAX_CLUSTERS];
Nicolas Pitre81543a92012-10-19 20:48:50 -040043
44static int tc2_pm_power_up(unsigned int cpu, unsigned int cluster)
45{
46 pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
Achin Gupta922b78c2013-03-10 22:36:51 +000047 if (cluster >= TC2_MAX_CLUSTERS ||
48 cpu >= vexpress_spc_get_nb_cpus(cluster))
Nicolas Pitre81543a92012-10-19 20:48:50 -040049 return -EINVAL;
50
51 /*
52 * Since this is called with IRQs enabled, and no arch_spin_lock_irq
53 * variant exists, we need to disable IRQs manually here.
54 */
55 local_irq_disable();
56 arch_spin_lock(&tc2_pm_lock);
57
58 if (!tc2_pm_use_count[0][cluster] &&
59 !tc2_pm_use_count[1][cluster] &&
60 !tc2_pm_use_count[2][cluster])
61 vexpress_spc_powerdown_enable(cluster, 0);
62
63 tc2_pm_use_count[cpu][cluster]++;
64 if (tc2_pm_use_count[cpu][cluster] == 1) {
Jon Medhurstdd94c6f2013-05-31 13:43:05 +010065 vexpress_spc_write_resume_reg(cluster, cpu,
Nicolas Pitre81543a92012-10-19 20:48:50 -040066 virt_to_phys(mcpm_entry_point));
67 vexpress_spc_set_cpu_wakeup_irq(cpu, cluster, 1);
68 } else if (tc2_pm_use_count[cpu][cluster] != 2) {
69 /*
70 * The only possible values are:
71 * 0 = CPU down
72 * 1 = CPU (still) up
73 * 2 = CPU requested to be up before it had a chance
74 * to actually make itself down.
75 * Any other value is a bug.
76 */
77 BUG();
78 }
79
80 arch_spin_unlock(&tc2_pm_lock);
81 local_irq_enable();
82
83 return 0;
84}
85
Nicolas Pitre3ce60842012-12-10 00:22:06 -050086static void tc2_pm_down(u64 residency)
Nicolas Pitre81543a92012-10-19 20:48:50 -040087{
88 unsigned int mpidr, cpu, cluster;
89 bool last_man = false, skip_wfi = false;
90
91 mpidr = read_cpuid_mpidr();
92 cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
93 cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
94
95 pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
Achin Gupta922b78c2013-03-10 22:36:51 +000096 BUG_ON(cluster >= TC2_MAX_CLUSTERS ||
97 cpu >= vexpress_spc_get_nb_cpus(cluster));
Nicolas Pitre81543a92012-10-19 20:48:50 -040098
99 __mcpm_cpu_going_down(cpu, cluster);
100
101 arch_spin_lock(&tc2_pm_lock);
102 BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);
103 tc2_pm_use_count[cpu][cluster]--;
104 if (tc2_pm_use_count[cpu][cluster] == 0) {
105 vexpress_spc_set_cpu_wakeup_irq(cpu, cluster, 1);
106 if (!tc2_pm_use_count[0][cluster] &&
107 !tc2_pm_use_count[1][cluster] &&
Nicolas Pitre3ce60842012-12-10 00:22:06 -0500108 !tc2_pm_use_count[2][cluster] &&
109 (!residency || residency > 5000)) {
Nicolas Pitre81543a92012-10-19 20:48:50 -0400110 vexpress_spc_powerdown_enable(cluster, 1);
111 vexpress_spc_set_global_wakeup_intr(1);
112 last_man = true;
113 }
114 } else if (tc2_pm_use_count[cpu][cluster] == 1) {
115 /*
116 * A power_up request went ahead of us.
117 * Even if we do not want to shut this CPU down,
118 * the caller expects a certain state as if the WFI
119 * was aborted. So let's continue with cache cleaning.
120 */
121 skip_wfi = true;
122 } else
123 BUG();
124
Lorenzo Pieralisi4bb2d492013-11-29 09:53:12 +0000125 /*
126 * If the CPU is committed to power down, make sure
127 * the power controller will be in charge of waking it
128 * up upon IRQ, ie IRQ lines are cut from GIC CPU IF
129 * to the CPU by disabling the GIC CPU IF to prevent wfi
130 * from completing execution behind power controller back
131 */
132 if (!skip_wfi)
133 gic_cpu_if_down();
Lorenzo Pieralisi0b94e1b2013-02-05 11:09:16 +0000134
Nicolas Pitre81543a92012-10-19 20:48:50 -0400135 if (last_man && __mcpm_outbound_enter_critical(cpu, cluster)) {
136 arch_spin_unlock(&tc2_pm_lock);
137
138 set_cr(get_cr() & ~CR_C);
139 flush_cache_all();
140 asm volatile ("clrex");
141 set_auxcr(get_auxcr() & ~(1 << 6));
142
Jon Medhurstd9552952013-05-09 16:50:56 +0100143 cci_disable_port_by_cpu(mpidr);
Nicolas Pitre81543a92012-10-19 20:48:50 -0400144
145 /*
146 * Ensure that both C & I bits are disabled in the SCTLR
147 * before disabling ACE snoops. This ensures that no
148 * coherency traffic will originate from this cpu after
149 * ACE snoops are turned off.
150 */
151 cpu_proc_fin();
152
153 __mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN);
154 } else {
155 /*
156 * If last man then undo any setup done previously.
157 */
158 if (last_man) {
159 vexpress_spc_powerdown_enable(cluster, 0);
160 vexpress_spc_set_global_wakeup_intr(0);
161 }
162
163 arch_spin_unlock(&tc2_pm_lock);
164
165 set_cr(get_cr() & ~CR_C);
166 flush_cache_louis();
167 asm volatile ("clrex");
168 set_auxcr(get_auxcr() & ~(1 << 6));
169 }
170
171 __mcpm_cpu_down(cpu, cluster);
172
173 /* Now we are prepared for power-down, do it: */
174 if (!skip_wfi)
175 wfi();
176
177 /* Not dead at this point? Let our caller cope. */
178}
179
Nicolas Pitre3ce60842012-12-10 00:22:06 -0500180static void tc2_pm_power_down(void)
181{
182 tc2_pm_down(0);
183}
184
185static void tc2_pm_suspend(u64 residency)
186{
Lorenzo Pieralisiaa55d812013-03-14 14:07:20 +0000187 extern void tc2_resume(void);
Nicolas Pitre3ce60842012-12-10 00:22:06 -0500188 unsigned int mpidr, cpu, cluster;
189
190 mpidr = read_cpuid_mpidr();
191 cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
192 cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
Jon Medhurstdd94c6f2013-05-31 13:43:05 +0100193 vexpress_spc_write_resume_reg(cluster, cpu,
Lorenzo Pieralisiaa55d812013-03-14 14:07:20 +0000194 virt_to_phys(tc2_resume));
195
Nicolas Pitre3ce60842012-12-10 00:22:06 -0500196 tc2_pm_down(residency);
197}
198
Nicolas Pitre81543a92012-10-19 20:48:50 -0400199static void tc2_pm_powered_up(void)
200{
201 unsigned int mpidr, cpu, cluster;
202 unsigned long flags;
203
204 mpidr = read_cpuid_mpidr();
205 cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
206 cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
207
208 pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
Achin Gupta922b78c2013-03-10 22:36:51 +0000209 BUG_ON(cluster >= TC2_MAX_CLUSTERS ||
210 cpu >= vexpress_spc_get_nb_cpus(cluster));
Nicolas Pitre81543a92012-10-19 20:48:50 -0400211
212 local_irq_save(flags);
213 arch_spin_lock(&tc2_pm_lock);
214
215 if (!tc2_pm_use_count[0][cluster] &&
216 !tc2_pm_use_count[1][cluster] &&
217 !tc2_pm_use_count[2][cluster]) {
218 vexpress_spc_powerdown_enable(cluster, 0);
219 vexpress_spc_set_global_wakeup_intr(0);
220 }
221
222 if (!tc2_pm_use_count[cpu][cluster])
223 tc2_pm_use_count[cpu][cluster] = 1;
224
225 vexpress_spc_set_cpu_wakeup_irq(cpu, cluster, 0);
Jon Medhurstdd94c6f2013-05-31 13:43:05 +0100226 vexpress_spc_write_resume_reg(cluster, cpu, 0);
Nicolas Pitre81543a92012-10-19 20:48:50 -0400227
228 arch_spin_unlock(&tc2_pm_lock);
229 local_irq_restore(flags);
230}
231
232static const struct mcpm_platform_ops tc2_pm_power_ops = {
233 .power_up = tc2_pm_power_up,
234 .power_down = tc2_pm_power_down,
Nicolas Pitre3ce60842012-12-10 00:22:06 -0500235 .suspend = tc2_pm_suspend,
Nicolas Pitre81543a92012-10-19 20:48:50 -0400236 .powered_up = tc2_pm_powered_up,
237};
238
239static void __init tc2_pm_usage_count_init(void)
240{
241 unsigned int mpidr, cpu, cluster;
242
243 mpidr = read_cpuid_mpidr();
244 cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
245 cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
246
247 pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
Achin Gupta922b78c2013-03-10 22:36:51 +0000248 BUG_ON(cluster >= TC2_MAX_CLUSTERS ||
249 cpu >= vexpress_spc_get_nb_cpus(cluster));
250
Nicolas Pitre81543a92012-10-19 20:48:50 -0400251 tc2_pm_use_count[cpu][cluster] = 1;
252}
253
254extern void tc2_pm_power_up_setup(unsigned int affinity_level);
255
256static int __init tc2_pm_init(void)
257{
258 int ret;
259
Achin Gupta58068c42012-12-17 00:15:00 +0000260 ret = psci_probe();
261 if (!ret) {
262 pr_debug("psci found. Aborting native init\n");
263 return -ENODEV;
264 }
265
Nicolas Pitre81543a92012-10-19 20:48:50 -0400266 if (!vexpress_spc_check_loaded())
267 return -ENODEV;
268
269 tc2_pm_usage_count_init();
270
271 ret = mcpm_platform_register(&tc2_pm_power_ops);
272 if (!ret)
273 ret = mcpm_sync_init(tc2_pm_power_up_setup);
274 if (!ret)
275 pr_info("TC2 power management initialized\n");
276 return ret;
277}
278
279early_initcall(tc2_pm_init);