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 return error; 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 Platfrom_finish; 146 } 147 148 if (suspend_ops->prepare_late) { 149 error = suspend_ops->prepare_late(); 150 if (error) 151 goto Power_up_devices; 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)) 167 error = suspend_ops->enter(state); 168 sysdev_resume(); 169 } 170 171 arch_suspend_enable_irqs(); 172 BUG_ON(irqs_disabled()); 173 174 Enable_cpus: 175 enable_nonboot_cpus(); 176 177 Platform_wake: 178 if (suspend_ops->wake) 179 suspend_ops->wake(); 180 181 Power_up_devices: 182 dpm_resume_noirq(PMSG_RESUME); 183 184 Platfrom_finish: 185 if (suspend_ops->finish) 186 suspend_ops->finish(); 187 188 return error; 189 } 190 191 /** 192 * suspend_devices_and_enter - suspend devices and enter the desired system 193 * sleep state. 194 * @state: state to enter 195 */ 196 int suspend_devices_and_enter(suspend_state_t state) 197 { 198 int error; 199 gfp_t saved_mask; 200 201 if (!suspend_ops) 202 return -ENOSYS; 203 204 if (suspend_ops->begin) { 205 error = suspend_ops->begin(state); 206 if (error) 207 goto Close; 208 } 209 suspend_console(); 210 saved_mask = clear_gfp_allowed_mask(GFP_IOFS); 211 suspend_test_start(); 212 error = dpm_suspend_start(PMSG_SUSPEND); 213 if (error) { 214 printk(KERN_ERR "PM: Some devices failed to suspend\n"); 215 goto Recover_platform; 216 } 217 suspend_test_finish("suspend devices"); 218 if (suspend_test(TEST_DEVICES)) 219 goto Recover_platform; 220 221 suspend_enter(state); 222 223 Resume_devices: 224 suspend_test_start(); 225 dpm_resume_end(PMSG_RESUME); 226 suspend_test_finish("resume devices"); 227 set_gfp_allowed_mask(saved_mask); 228 resume_console(); 229 Close: 230 if (suspend_ops->end) 231 suspend_ops->end(); 232 return error; 233 234 Recover_platform: 235 if (suspend_ops->recover) 236 suspend_ops->recover(); 237 goto Resume_devices; 238 } 239 240 /** 241 * suspend_finish - Do final work before exiting suspend sequence. 242 * 243 * Call platform code to clean up, restart processes, and free the 244 * console that we've allocated. This is not called for suspend-to-disk. 245 */ 246 static void suspend_finish(void) 247 { 248 suspend_thaw_processes(); 249 usermodehelper_enable(); 250 pm_notifier_call_chain(PM_POST_SUSPEND); 251 pm_restore_console(); 252 } 253 254 /** 255 * enter_state - Do common work of entering low-power state. 256 * @state: pm_state structure for state we're entering. 257 * 258 * Make sure we're the only ones trying to enter a sleep state. Fail 259 * if someone has beat us to it, since we don't want anything weird to 260 * happen when we wake up. 261 * Then, do the setup for suspend, enter the state, and cleaup (after 262 * we've woken up). 263 */ 264 int enter_state(suspend_state_t state) 265 { 266 int error; 267 268 if (!valid_state(state)) 269 return -ENODEV; 270 271 if (!mutex_trylock(&pm_mutex)) 272 return -EBUSY; 273 274 printk(KERN_INFO "PM: Syncing filesystems ... "); 275 sys_sync(); 276 printk("done.\n"); 277 278 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); 279 error = suspend_prepare(); 280 if (error) 281 goto Unlock; 282 283 if (suspend_test(TEST_FREEZER)) 284 goto Finish; 285 286 pr_debug("PM: Entering %s sleep\n", pm_states[state]); 287 error = suspend_devices_and_enter(state); 288 289 Finish: 290 pr_debug("PM: Finishing wakeup.\n"); 291 suspend_finish(); 292 Unlock: 293 mutex_unlock(&pm_mutex); 294 return error; 295 } 296 297 /** 298 * pm_suspend - Externally visible function for suspending system. 299 * @state: Enumerated value of state to enter. 300 * 301 * Determine whether or not value is within range, get state 302 * structure, and enter (above). 303 */ 304 int pm_suspend(suspend_state_t state) 305 { 306 if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) 307 return enter_state(state); 308 return -EINVAL; 309 } 310 EXPORT_SYMBOL(pm_suspend); 311