1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. 4 * 5 * This file contains power management functions related to interrupts. 6 */ 7 8 #include <linux/irq.h> 9 #include <linux/module.h> 10 #include <linux/interrupt.h> 11 #include <linux/suspend.h> 12 #include <linux/syscore_ops.h> 13 14 #include "internals.h" 15 16 bool irq_pm_check_wakeup(struct irq_desc *desc) 17 { 18 if (irqd_is_wakeup_armed(&desc->irq_data)) { 19 irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED); 20 desc->istate |= IRQS_SUSPENDED | IRQS_PENDING; 21 desc->depth++; 22 irq_disable(desc); 23 pm_system_irq_wakeup(irq_desc_get_irq(desc)); 24 return true; 25 } 26 return false; 27 } 28 29 /* 30 * Called from __setup_irq() with desc->lock held after @action has 31 * been installed in the action chain. 32 */ 33 void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action) 34 { 35 desc->nr_actions++; 36 37 if (action->flags & IRQF_FORCE_RESUME) 38 desc->force_resume_depth++; 39 40 WARN_ON_ONCE(desc->force_resume_depth && 41 desc->force_resume_depth != desc->nr_actions); 42 43 if (action->flags & IRQF_NO_SUSPEND) 44 desc->no_suspend_depth++; 45 else if (action->flags & IRQF_COND_SUSPEND) 46 desc->cond_suspend_depth++; 47 48 WARN_ON_ONCE(desc->no_suspend_depth && 49 (desc->no_suspend_depth + 50 desc->cond_suspend_depth) != desc->nr_actions); 51 } 52 53 /* 54 * Called from __free_irq() with desc->lock held after @action has 55 * been removed from the action chain. 56 */ 57 void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action) 58 { 59 desc->nr_actions--; 60 61 if (action->flags & IRQF_FORCE_RESUME) 62 desc->force_resume_depth--; 63 64 if (action->flags & IRQF_NO_SUSPEND) 65 desc->no_suspend_depth--; 66 else if (action->flags & IRQF_COND_SUSPEND) 67 desc->cond_suspend_depth--; 68 } 69 70 static bool suspend_device_irq(struct irq_desc *desc) 71 { 72 unsigned long chipflags = irq_desc_get_chip(desc)->flags; 73 struct irq_data *irqd = &desc->irq_data; 74 75 if (!desc->action || irq_desc_is_chained(desc) || 76 desc->no_suspend_depth) 77 return false; 78 79 if (irqd_is_wakeup_set(irqd)) { 80 irqd_set(irqd, IRQD_WAKEUP_ARMED); 81 82 if ((chipflags & IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND) && 83 irqd_irq_disabled(irqd)) { 84 /* 85 * Interrupt marked for wakeup is in disabled state. 86 * Enable interrupt here to unmask/enable in irqchip 87 * to be able to resume with such interrupts. 88 */ 89 __enable_irq(desc); 90 irqd_set(irqd, IRQD_IRQ_ENABLED_ON_SUSPEND); 91 } 92 /* 93 * We return true here to force the caller to issue 94 * synchronize_irq(). We need to make sure that the 95 * IRQD_WAKEUP_ARMED is visible before we return from 96 * suspend_device_irqs(). 97 */ 98 return true; 99 } 100 101 desc->istate |= IRQS_SUSPENDED; 102 __disable_irq(desc); 103 104 /* 105 * Hardware which has no wakeup source configuration facility 106 * requires that the non wakeup interrupts are masked at the 107 * chip level. The chip implementation indicates that with 108 * IRQCHIP_MASK_ON_SUSPEND. 109 */ 110 if (chipflags & IRQCHIP_MASK_ON_SUSPEND) 111 mask_irq(desc); 112 return true; 113 } 114 115 /** 116 * suspend_device_irqs - disable all currently enabled interrupt lines 117 * 118 * During system-wide suspend or hibernation device drivers need to be 119 * prevented from receiving interrupts and this function is provided 120 * for this purpose. 121 * 122 * So we disable all interrupts and mark them IRQS_SUSPENDED except 123 * for those which are unused, those which are marked as not 124 * suspendable via an interrupt request with the flag IRQF_NO_SUSPEND 125 * set and those which are marked as active wakeup sources. 126 * 127 * The active wakeup sources are handled by the flow handler entry 128 * code which checks for the IRQD_WAKEUP_ARMED flag, suspends the 129 * interrupt and notifies the pm core about the wakeup. 130 */ 131 void suspend_device_irqs(void) 132 { 133 struct irq_desc *desc; 134 int irq; 135 136 for_each_irq_desc(irq, desc) { 137 unsigned long flags; 138 bool sync; 139 140 if (irq_settings_is_nested_thread(desc)) 141 continue; 142 raw_spin_lock_irqsave(&desc->lock, flags); 143 sync = suspend_device_irq(desc); 144 raw_spin_unlock_irqrestore(&desc->lock, flags); 145 146 if (sync) 147 synchronize_irq(irq); 148 } 149 } 150 151 static void resume_irq(struct irq_desc *desc) 152 { 153 struct irq_data *irqd = &desc->irq_data; 154 155 irqd_clear(irqd, IRQD_WAKEUP_ARMED); 156 157 if (irqd_is_enabled_on_suspend(irqd)) { 158 /* 159 * Interrupt marked for wakeup was enabled during suspend 160 * entry. Disable such interrupts to restore them back to 161 * original state. 162 */ 163 __disable_irq(desc); 164 irqd_clear(irqd, IRQD_IRQ_ENABLED_ON_SUSPEND); 165 } 166 167 if (desc->istate & IRQS_SUSPENDED) 168 goto resume; 169 170 /* Force resume the interrupt? */ 171 if (!desc->force_resume_depth) 172 return; 173 174 /* Pretend that it got disabled ! */ 175 desc->depth++; 176 irq_state_set_disabled(desc); 177 irq_state_set_masked(desc); 178 resume: 179 desc->istate &= ~IRQS_SUSPENDED; 180 __enable_irq(desc); 181 } 182 183 static void resume_irqs(bool want_early) 184 { 185 struct irq_desc *desc; 186 int irq; 187 188 for_each_irq_desc(irq, desc) { 189 unsigned long flags; 190 bool is_early = desc->action && 191 desc->action->flags & IRQF_EARLY_RESUME; 192 193 if (!is_early && want_early) 194 continue; 195 if (irq_settings_is_nested_thread(desc)) 196 continue; 197 198 raw_spin_lock_irqsave(&desc->lock, flags); 199 resume_irq(desc); 200 raw_spin_unlock_irqrestore(&desc->lock, flags); 201 } 202 } 203 204 /** 205 * rearm_wake_irq - rearm a wakeup interrupt line after signaling wakeup 206 * @irq: Interrupt to rearm 207 */ 208 void rearm_wake_irq(unsigned int irq) 209 { 210 unsigned long flags; 211 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); 212 213 if (!desc) 214 return; 215 216 if (!(desc->istate & IRQS_SUSPENDED) || 217 !irqd_is_wakeup_set(&desc->irq_data)) 218 goto unlock; 219 220 desc->istate &= ~IRQS_SUSPENDED; 221 irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED); 222 __enable_irq(desc); 223 224 unlock: 225 irq_put_desc_busunlock(desc, flags); 226 } 227 228 /** 229 * irq_pm_syscore_resume - enable interrupt lines early 230 * 231 * Enable all interrupt lines with %IRQF_EARLY_RESUME set. 232 */ 233 static void irq_pm_syscore_resume(void) 234 { 235 resume_irqs(true); 236 } 237 238 static struct syscore_ops irq_pm_syscore_ops = { 239 .resume = irq_pm_syscore_resume, 240 }; 241 242 static int __init irq_pm_init_ops(void) 243 { 244 register_syscore_ops(&irq_pm_syscore_ops); 245 return 0; 246 } 247 248 device_initcall(irq_pm_init_ops); 249 250 /** 251 * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs() 252 * 253 * Enable all non-%IRQF_EARLY_RESUME interrupt lines previously 254 * disabled by suspend_device_irqs() that have the IRQS_SUSPENDED flag 255 * set as well as those with %IRQF_FORCE_RESUME. 256 */ 257 void resume_device_irqs(void) 258 { 259 resume_irqs(false); 260 } 261