1 /* 2 * kernel/power/suspend.c - Suspend to RAM and standby functionality. 3 * 4 * Copyright (c) 2003 Patrick Mochel 5 * Copyright (c) 2003 Open Source Development Lab 6 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. 7 * 8 * This file is released under the GPLv2. 9 */ 10 11 #include <linux/string.h> 12 #include <linux/delay.h> 13 #include <linux/errno.h> 14 #include <linux/init.h> 15 #include <linux/console.h> 16 #include <linux/cpu.h> 17 #include <linux/syscalls.h> 18 19 #include "power.h" 20 21 const char *const pm_states[PM_SUSPEND_MAX] = { 22 [PM_SUSPEND_STANDBY] = "standby", 23 [PM_SUSPEND_MEM] = "mem", 24 }; 25 26 static struct platform_suspend_ops *suspend_ops; 27 28 /** 29 * suspend_set_ops - Set the global suspend method table. 30 * @ops: Pointer to ops structure. 31 */ 32 void suspend_set_ops(struct platform_suspend_ops *ops) 33 { 34 mutex_lock(&pm_mutex); 35 suspend_ops = ops; 36 mutex_unlock(&pm_mutex); 37 } 38 39 bool valid_state(suspend_state_t state) 40 { 41 /* 42 * All states need lowlevel support and need to be valid to the lowlevel 43 * implementation, no valid callback implies that none are valid. 44 */ 45 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state); 46 } 47 48 /** 49 * suspend_valid_only_mem - generic memory-only valid callback 50 * 51 * Platform drivers that implement mem suspend only and only need 52 * to check for that in their .valid callback can use this instead 53 * of rolling their own .valid callback. 54 */ 55 int suspend_valid_only_mem(suspend_state_t state) 56 { 57 return state == PM_SUSPEND_MEM; 58 } 59 60 static int suspend_test(int level) 61 { 62 #ifdef CONFIG_PM_DEBUG 63 if (pm_test_level == level) { 64 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n"); 65 mdelay(5000); 66 return 1; 67 } 68 #endif /* !CONFIG_PM_DEBUG */ 69 return 0; 70 } 71 72 /** 73 * suspend_prepare - Do prep work before entering low-power state. 74 * 75 * This is common code that is called for each state that we're entering. 76 * Run suspend notifiers, allocate a console and stop all processes. 77 */ 78 static int suspend_prepare(void) 79 { 80 int error; 81 82 if (!suspend_ops || !suspend_ops->enter) 83 return -EPERM; 84 85 pm_prepare_console(); 86 87 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE); 88 if (error) 89 goto Finish; 90 91 error = usermodehelper_disable(); 92 if (error) 93 goto Finish; 94 95 error = suspend_freeze_processes(); 96 if (!error) 97 return 0; 98 99 suspend_thaw_processes(); 100 usermodehelper_enable(); 101 Finish: 102 pm_notifier_call_chain(PM_POST_SUSPEND); 103 pm_restore_console(); 104 return error; 105 } 106 107 /* default implementation */ 108 void __attribute__ ((weak)) arch_suspend_disable_irqs(void) 109 { 110 local_irq_disable(); 111 } 112 113 /* default implementation */ 114 void __attribute__ ((weak)) arch_suspend_enable_irqs(void) 115 { 116 local_irq_enable(); 117 } 118 119 /** 120 * suspend_enter - enter the desired system sleep state. 121 * @state: state to enter 122 * 123 * This function should be called after devices have been suspended. 124 */ 125 static int suspend_enter(suspend_state_t state) 126 { 127 int error; 128 129 if (suspend_ops->prepare) { 130 error = suspend_ops->prepare(); 131 if (error) 132 return error; 133 } 134 135 error = dpm_suspend_noirq(PMSG_SUSPEND); 136 if (error) { 137 printk(KERN_ERR "PM: Some devices failed to power down\n"); 138 goto Platfrom_finish; 139 } 140 141 if (suspend_ops->prepare_late) { 142 error = suspend_ops->prepare_late(); 143 if (error) 144 goto Power_up_devices; 145 } 146 147 if (suspend_test(TEST_PLATFORM)) 148 goto Platform_wake; 149 150 error = disable_nonboot_cpus(); 151 if (error || suspend_test(TEST_CPUS)) 152 goto Enable_cpus; 153 154 arch_suspend_disable_irqs(); 155 BUG_ON(!irqs_disabled()); 156 157 error = sysdev_suspend(PMSG_SUSPEND); 158 if (!error) { 159 if (!suspend_test(TEST_CORE)) 160 error = suspend_ops->enter(state); 161 sysdev_resume(); 162 } 163 164 arch_suspend_enable_irqs(); 165 BUG_ON(irqs_disabled()); 166 167 Enable_cpus: 168 enable_nonboot_cpus(); 169 170 Platform_wake: 171 if (suspend_ops->wake) 172 suspend_ops->wake(); 173 174 Power_up_devices: 175 dpm_resume_noirq(PMSG_RESUME); 176 177 Platfrom_finish: 178 if (suspend_ops->finish) 179 suspend_ops->finish(); 180 181 return error; 182 } 183 184 /** 185 * suspend_devices_and_enter - suspend devices and enter the desired system 186 * sleep state. 187 * @state: state to enter 188 */ 189 int suspend_devices_and_enter(suspend_state_t state) 190 { 191 int error; 192 gfp_t saved_mask; 193 194 if (!suspend_ops) 195 return -ENOSYS; 196 197 if (suspend_ops->begin) { 198 error = suspend_ops->begin(state); 199 if (error) 200 goto Close; 201 } 202 suspend_console(); 203 saved_mask = clear_gfp_allowed_mask(GFP_IOFS); 204 suspend_test_start(); 205 error = dpm_suspend_start(PMSG_SUSPEND); 206 if (error) { 207 printk(KERN_ERR "PM: Some devices failed to suspend\n"); 208 goto Recover_platform; 209 } 210 suspend_test_finish("suspend devices"); 211 if (suspend_test(TEST_DEVICES)) 212 goto Recover_platform; 213 214 suspend_enter(state); 215 216 Resume_devices: 217 suspend_test_start(); 218 dpm_resume_end(PMSG_RESUME); 219 suspend_test_finish("resume devices"); 220 set_gfp_allowed_mask(saved_mask); 221 resume_console(); 222 Close: 223 if (suspend_ops->end) 224 suspend_ops->end(); 225 return error; 226 227 Recover_platform: 228 if (suspend_ops->recover) 229 suspend_ops->recover(); 230 goto Resume_devices; 231 } 232 233 /** 234 * suspend_finish - Do final work before exiting suspend sequence. 235 * 236 * Call platform code to clean up, restart processes, and free the 237 * console that we've allocated. This is not called for suspend-to-disk. 238 */ 239 static void suspend_finish(void) 240 { 241 suspend_thaw_processes(); 242 usermodehelper_enable(); 243 pm_notifier_call_chain(PM_POST_SUSPEND); 244 pm_restore_console(); 245 } 246 247 /** 248 * enter_state - Do common work of entering low-power state. 249 * @state: pm_state structure for state we're entering. 250 * 251 * Make sure we're the only ones trying to enter a sleep state. Fail 252 * if someone has beat us to it, since we don't want anything weird to 253 * happen when we wake up. 254 * Then, do the setup for suspend, enter the state, and cleaup (after 255 * we've woken up). 256 */ 257 int enter_state(suspend_state_t state) 258 { 259 int error; 260 261 if (!valid_state(state)) 262 return -ENODEV; 263 264 if (!mutex_trylock(&pm_mutex)) 265 return -EBUSY; 266 267 printk(KERN_INFO "PM: Syncing filesystems ... "); 268 sys_sync(); 269 printk("done.\n"); 270 271 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); 272 error = suspend_prepare(); 273 if (error) 274 goto Unlock; 275 276 if (suspend_test(TEST_FREEZER)) 277 goto Finish; 278 279 pr_debug("PM: Entering %s sleep\n", pm_states[state]); 280 error = suspend_devices_and_enter(state); 281 282 Finish: 283 pr_debug("PM: Finishing wakeup.\n"); 284 suspend_finish(); 285 Unlock: 286 mutex_unlock(&pm_mutex); 287 return error; 288 } 289 290 /** 291 * pm_suspend - Externally visible function for suspending system. 292 * @state: Enumerated value of state to enter. 293 * 294 * Determine whether or not value is within range, get state 295 * structure, and enter (above). 296 */ 297 int pm_suspend(suspend_state_t state) 298 { 299 if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) 300 return enter_state(state); 301 return -EINVAL; 302 } 303 EXPORT_SYMBOL(pm_suspend); 304