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 #include <linux/gfp.h> 19 #include <linux/io.h> 20 #include <linux/kernel.h> 21 #include <linux/list.h> 22 #include <linux/mm.h> 23 #include <linux/slab.h> 24 #include <linux/suspend.h> 25 26 #include "power.h" 27 28 const char *const pm_states[PM_SUSPEND_MAX] = { 29 [PM_SUSPEND_STANDBY] = "standby", 30 [PM_SUSPEND_MEM] = "mem", 31 }; 32 33 static struct platform_suspend_ops *suspend_ops; 34 35 /** 36 * suspend_set_ops - Set the global suspend method table. 37 * @ops: Pointer to ops structure. 38 */ 39 void suspend_set_ops(struct platform_suspend_ops *ops) 40 { 41 mutex_lock(&pm_mutex); 42 suspend_ops = ops; 43 mutex_unlock(&pm_mutex); 44 } 45 46 bool valid_state(suspend_state_t state) 47 { 48 /* 49 * All states need lowlevel support and need to be valid to the lowlevel 50 * implementation, no valid callback implies that none are valid. 51 */ 52 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state); 53 } 54 55 /** 56 * suspend_valid_only_mem - generic memory-only valid callback 57 * 58 * Platform drivers that implement mem suspend only and only need 59 * to check for that in their .valid callback can use this instead 60 * of rolling their own .valid callback. 61 */ 62 int suspend_valid_only_mem(suspend_state_t state) 63 { 64 return state == PM_SUSPEND_MEM; 65 } 66 67 static int suspend_test(int level) 68 { 69 #ifdef CONFIG_PM_DEBUG 70 if (pm_test_level == level) { 71 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n"); 72 mdelay(5000); 73 return 1; 74 } 75 #endif /* !CONFIG_PM_DEBUG */ 76 return 0; 77 } 78 79 /** 80 * suspend_prepare - Do prep work before entering low-power state. 81 * 82 * This is common code that is called for each state that we're entering. 83 * Run suspend notifiers, allocate a console and stop all processes. 84 */ 85 static int suspend_prepare(void) 86 { 87 int error; 88 89 if (!suspend_ops || !suspend_ops->enter) 90 return -EPERM; 91 92 pm_prepare_console(); 93 94 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE); 95 if (error) 96 goto Finish; 97 98 error = usermodehelper_disable(); 99 if (error) 100 goto Finish; 101 102 error = suspend_freeze_processes(); 103 if (!error) 104 return 0; 105 106 suspend_thaw_processes(); 107 usermodehelper_enable(); 108 Finish: 109 pm_notifier_call_chain(PM_POST_SUSPEND); 110 pm_restore_console(); 111 return error; 112 } 113 114 /* default implementation */ 115 void __attribute__ ((weak)) arch_suspend_disable_irqs(void) 116 { 117 local_irq_disable(); 118 } 119 120 /* default implementation */ 121 void __attribute__ ((weak)) arch_suspend_enable_irqs(void) 122 { 123 local_irq_enable(); 124 } 125 126 /** 127 * suspend_enter - enter the desired system sleep state. 128 * @state: state to enter 129 * 130 * This function should be called after devices have been suspended. 131 */ 132 static int suspend_enter(suspend_state_t state) 133 { 134 int error; 135 136 if (suspend_ops->prepare) { 137 error = suspend_ops->prepare(); 138 if (error) 139 goto Platform_finish; 140 } 141 142 error = dpm_suspend_noirq(PMSG_SUSPEND); 143 if (error) { 144 printk(KERN_ERR "PM: Some devices failed to power down\n"); 145 goto Platform_finish; 146 } 147 148 if (suspend_ops->prepare_late) { 149 error = suspend_ops->prepare_late(); 150 if (error) 151 goto Platform_wake; 152 } 153 154 if (suspend_test(TEST_PLATFORM)) 155 goto Platform_wake; 156 157 error = disable_nonboot_cpus(); 158 if (error || suspend_test(TEST_CPUS)) 159 goto Enable_cpus; 160 161 arch_suspend_disable_irqs(); 162 BUG_ON(!irqs_disabled()); 163 164 error = sysdev_suspend(PMSG_SUSPEND); 165 if (!error) { 166 if (!suspend_test(TEST_CORE) && pm_check_wakeup_events()) { 167 error = suspend_ops->enter(state); 168 events_check_enabled = false; 169 } 170 sysdev_resume(); 171 } 172 173 arch_suspend_enable_irqs(); 174 BUG_ON(irqs_disabled()); 175 176 Enable_cpus: 177 enable_nonboot_cpus(); 178 179 Platform_wake: 180 if (suspend_ops->wake) 181 suspend_ops->wake(); 182 183 dpm_resume_noirq(PMSG_RESUME); 184 185 Platform_finish: 186 if (suspend_ops->finish) 187 suspend_ops->finish(); 188 189 return error; 190 } 191 192 /** 193 * suspend_devices_and_enter - suspend devices and enter the desired system 194 * sleep state. 195 * @state: state to enter 196 */ 197 int suspend_devices_and_enter(suspend_state_t state) 198 { 199 int error; 200 gfp_t saved_mask; 201 202 if (!suspend_ops) 203 return -ENOSYS; 204 205 if (suspend_ops->begin) { 206 error = suspend_ops->begin(state); 207 if (error) 208 goto Close; 209 } 210 suspend_console(); 211 saved_mask = clear_gfp_allowed_mask(GFP_IOFS); 212 suspend_test_start(); 213 error = dpm_suspend_start(PMSG_SUSPEND); 214 if (error) { 215 printk(KERN_ERR "PM: Some devices failed to suspend\n"); 216 goto Recover_platform; 217 } 218 suspend_test_finish("suspend devices"); 219 if (suspend_test(TEST_DEVICES)) 220 goto Recover_platform; 221 222 suspend_enter(state); 223 224 Resume_devices: 225 suspend_test_start(); 226 dpm_resume_end(PMSG_RESUME); 227 suspend_test_finish("resume devices"); 228 set_gfp_allowed_mask(saved_mask); 229 resume_console(); 230 Close: 231 if (suspend_ops->end) 232 suspend_ops->end(); 233 return error; 234 235 Recover_platform: 236 if (suspend_ops->recover) 237 suspend_ops->recover(); 238 goto Resume_devices; 239 } 240 241 /** 242 * suspend_finish - Do final work before exiting suspend sequence. 243 * 244 * Call platform code to clean up, restart processes, and free the 245 * console that we've allocated. This is not called for suspend-to-disk. 246 */ 247 static void suspend_finish(void) 248 { 249 suspend_thaw_processes(); 250 usermodehelper_enable(); 251 pm_notifier_call_chain(PM_POST_SUSPEND); 252 pm_restore_console(); 253 } 254 255 /** 256 * enter_state - Do common work of entering low-power state. 257 * @state: pm_state structure for state we're entering. 258 * 259 * Make sure we're the only ones trying to enter a sleep state. Fail 260 * if someone has beat us to it, since we don't want anything weird to 261 * happen when we wake up. 262 * Then, do the setup for suspend, enter the state, and cleaup (after 263 * we've woken up). 264 */ 265 int enter_state(suspend_state_t state) 266 { 267 int error; 268 269 if (!valid_state(state)) 270 return -ENODEV; 271 272 if (!mutex_trylock(&pm_mutex)) 273 return -EBUSY; 274 275 printk(KERN_INFO "PM: Syncing filesystems ... "); 276 sys_sync(); 277 printk("done.\n"); 278 279 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); 280 error = suspend_prepare(); 281 if (error) 282 goto Unlock; 283 284 if (suspend_test(TEST_FREEZER)) 285 goto Finish; 286 287 pr_debug("PM: Entering %s sleep\n", pm_states[state]); 288 error = suspend_devices_and_enter(state); 289 290 Finish: 291 pr_debug("PM: Finishing wakeup.\n"); 292 suspend_finish(); 293 Unlock: 294 mutex_unlock(&pm_mutex); 295 return error; 296 } 297 298 /** 299 * pm_suspend - Externally visible function for suspending system. 300 * @state: Enumerated value of state to enter. 301 * 302 * Determine whether or not value is within range, get state 303 * structure, and enter (above). 304 */ 305 int pm_suspend(suspend_state_t state) 306 { 307 if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) 308 return enter_state(state); 309 return -EINVAL; 310 } 311 EXPORT_SYMBOL(pm_suspend); 312