Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 1 | /* |
| 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 Pieralisi | 0b94e1b | 2013-02-05 11:09:16 +0000 | [diff] [blame] | 19 | #include <linux/irqchip/arm-gic.h> |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 20 | |
| 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 Gupta | 58068c4 | 2012-12-17 00:15:00 +0000 | [diff] [blame] | 26 | #include <asm/psci.h> |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 27 | |
| 28 | #include <mach/motherboard.h> |
Achin Gupta | 922b78c | 2013-03-10 22:36:51 +0000 | [diff] [blame] | 29 | #include <mach/tc2.h> |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 30 | |
| 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 | */ |
| 40 | static arch_spinlock_t tc2_pm_lock = __ARCH_SPIN_LOCK_UNLOCKED; |
| 41 | |
Achin Gupta | 922b78c | 2013-03-10 22:36:51 +0000 | [diff] [blame] | 42 | static int tc2_pm_use_count[TC2_MAX_CPUS][TC2_MAX_CLUSTERS]; |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 43 | |
| 44 | static 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 Gupta | 922b78c | 2013-03-10 22:36:51 +0000 | [diff] [blame] | 47 | if (cluster >= TC2_MAX_CLUSTERS || |
| 48 | cpu >= vexpress_spc_get_nb_cpus(cluster)) |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 49 | 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 Medhurst | dd94c6f | 2013-05-31 13:43:05 +0100 | [diff] [blame] | 65 | vexpress_spc_write_resume_reg(cluster, cpu, |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 66 | 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 Pitre | 3ce6084 | 2012-12-10 00:22:06 -0500 | [diff] [blame] | 86 | static void tc2_pm_down(u64 residency) |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 87 | { |
| 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 Gupta | 922b78c | 2013-03-10 22:36:51 +0000 | [diff] [blame] | 96 | BUG_ON(cluster >= TC2_MAX_CLUSTERS || |
| 97 | cpu >= vexpress_spc_get_nb_cpus(cluster)); |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 98 | |
| 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 Pitre | 3ce6084 | 2012-12-10 00:22:06 -0500 | [diff] [blame] | 108 | !tc2_pm_use_count[2][cluster] && |
| 109 | (!residency || residency > 5000)) { |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 110 | 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 Pieralisi | 4bb2d49 | 2013-11-29 09:53:12 +0000 | [diff] [blame^] | 125 | /* |
| 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 Pieralisi | 0b94e1b | 2013-02-05 11:09:16 +0000 | [diff] [blame] | 134 | |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 135 | 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 Medhurst | d955295 | 2013-05-09 16:50:56 +0100 | [diff] [blame] | 143 | cci_disable_port_by_cpu(mpidr); |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 144 | |
| 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 Pitre | 3ce6084 | 2012-12-10 00:22:06 -0500 | [diff] [blame] | 180 | static void tc2_pm_power_down(void) |
| 181 | { |
| 182 | tc2_pm_down(0); |
| 183 | } |
| 184 | |
| 185 | static void tc2_pm_suspend(u64 residency) |
| 186 | { |
Lorenzo Pieralisi | aa55d81 | 2013-03-14 14:07:20 +0000 | [diff] [blame] | 187 | extern void tc2_resume(void); |
Nicolas Pitre | 3ce6084 | 2012-12-10 00:22:06 -0500 | [diff] [blame] | 188 | 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 Medhurst | dd94c6f | 2013-05-31 13:43:05 +0100 | [diff] [blame] | 193 | vexpress_spc_write_resume_reg(cluster, cpu, |
Lorenzo Pieralisi | aa55d81 | 2013-03-14 14:07:20 +0000 | [diff] [blame] | 194 | virt_to_phys(tc2_resume)); |
| 195 | |
Nicolas Pitre | 3ce6084 | 2012-12-10 00:22:06 -0500 | [diff] [blame] | 196 | tc2_pm_down(residency); |
| 197 | } |
| 198 | |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 199 | static 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 Gupta | 922b78c | 2013-03-10 22:36:51 +0000 | [diff] [blame] | 209 | BUG_ON(cluster >= TC2_MAX_CLUSTERS || |
| 210 | cpu >= vexpress_spc_get_nb_cpus(cluster)); |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 211 | |
| 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 Medhurst | dd94c6f | 2013-05-31 13:43:05 +0100 | [diff] [blame] | 226 | vexpress_spc_write_resume_reg(cluster, cpu, 0); |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 227 | |
| 228 | arch_spin_unlock(&tc2_pm_lock); |
| 229 | local_irq_restore(flags); |
| 230 | } |
| 231 | |
| 232 | static const struct mcpm_platform_ops tc2_pm_power_ops = { |
| 233 | .power_up = tc2_pm_power_up, |
| 234 | .power_down = tc2_pm_power_down, |
Nicolas Pitre | 3ce6084 | 2012-12-10 00:22:06 -0500 | [diff] [blame] | 235 | .suspend = tc2_pm_suspend, |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 236 | .powered_up = tc2_pm_powered_up, |
| 237 | }; |
| 238 | |
| 239 | static 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 Gupta | 922b78c | 2013-03-10 22:36:51 +0000 | [diff] [blame] | 248 | BUG_ON(cluster >= TC2_MAX_CLUSTERS || |
| 249 | cpu >= vexpress_spc_get_nb_cpus(cluster)); |
| 250 | |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 251 | tc2_pm_use_count[cpu][cluster] = 1; |
| 252 | } |
| 253 | |
| 254 | extern void tc2_pm_power_up_setup(unsigned int affinity_level); |
| 255 | |
| 256 | static int __init tc2_pm_init(void) |
| 257 | { |
| 258 | int ret; |
| 259 | |
Achin Gupta | 58068c4 | 2012-12-17 00:15:00 +0000 | [diff] [blame] | 260 | ret = psci_probe(); |
| 261 | if (!ret) { |
| 262 | pr_debug("psci found. Aborting native init\n"); |
| 263 | return -ENODEV; |
| 264 | } |
| 265 | |
Nicolas Pitre | 81543a9 | 2012-10-19 20:48:50 -0400 | [diff] [blame] | 266 | 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 | |
| 279 | early_initcall(tc2_pm_init); |