cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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pm.h (36198B)


      1/* SPDX-License-Identifier: GPL-2.0-or-later */
      2/*
      3 *  pm.h - Power management interface
      4 *
      5 *  Copyright (C) 2000 Andrew Henroid
      6 */
      7
      8#ifndef _LINUX_PM_H
      9#define _LINUX_PM_H
     10
     11#include <linux/export.h>
     12#include <linux/list.h>
     13#include <linux/workqueue.h>
     14#include <linux/spinlock.h>
     15#include <linux/wait.h>
     16#include <linux/timer.h>
     17#include <linux/hrtimer.h>
     18#include <linux/completion.h>
     19
     20/*
     21 * Callbacks for platform drivers to implement.
     22 */
     23extern void (*pm_power_off)(void);
     24
     25struct device; /* we have a circular dep with device.h */
     26#ifdef CONFIG_VT_CONSOLE_SLEEP
     27extern void pm_vt_switch_required(struct device *dev, bool required);
     28extern void pm_vt_switch_unregister(struct device *dev);
     29#else
     30static inline void pm_vt_switch_required(struct device *dev, bool required)
     31{
     32}
     33static inline void pm_vt_switch_unregister(struct device *dev)
     34{
     35}
     36#endif /* CONFIG_VT_CONSOLE_SLEEP */
     37
     38#ifdef CONFIG_CXL_SUSPEND
     39bool cxl_mem_active(void);
     40#else
     41static inline bool cxl_mem_active(void)
     42{
     43	return false;
     44}
     45#endif
     46
     47/*
     48 * Device power management
     49 */
     50
     51
     52#ifdef CONFIG_PM
     53extern const char power_group_name[];		/* = "power" */
     54#else
     55#define power_group_name	NULL
     56#endif
     57
     58typedef struct pm_message {
     59	int event;
     60} pm_message_t;
     61
     62/**
     63 * struct dev_pm_ops - device PM callbacks.
     64 *
     65 * @prepare: The principal role of this callback is to prevent new children of
     66 *	the device from being registered after it has returned (the driver's
     67 *	subsystem and generally the rest of the kernel is supposed to prevent
     68 *	new calls to the probe method from being made too once @prepare() has
     69 *	succeeded).  If @prepare() detects a situation it cannot handle (e.g.
     70 *	registration of a child already in progress), it may return -EAGAIN, so
     71 *	that the PM core can execute it once again (e.g. after a new child has
     72 *	been registered) to recover from the race condition.
     73 *	This method is executed for all kinds of suspend transitions and is
     74 *	followed by one of the suspend callbacks: @suspend(), @freeze(), or
     75 *	@poweroff().  If the transition is a suspend to memory or standby (that
     76 *	is, not related to hibernation), the return value of @prepare() may be
     77 *	used to indicate to the PM core to leave the device in runtime suspend
     78 *	if applicable.  Namely, if @prepare() returns a positive number, the PM
     79 *	core will understand that as a declaration that the device appears to be
     80 *	runtime-suspended and it may be left in that state during the entire
     81 *	transition and during the subsequent resume if all of its descendants
     82 *	are left in runtime suspend too.  If that happens, @complete() will be
     83 *	executed directly after @prepare() and it must ensure the proper
     84 *	functioning of the device after the system resume.
     85 *	The PM core executes subsystem-level @prepare() for all devices before
     86 *	starting to invoke suspend callbacks for any of them, so generally
     87 *	devices may be assumed to be functional or to respond to runtime resume
     88 *	requests while @prepare() is being executed.  However, device drivers
     89 *	may NOT assume anything about the availability of user space at that
     90 *	time and it is NOT valid to request firmware from within @prepare()
     91 *	(it's too late to do that).  It also is NOT valid to allocate
     92 *	substantial amounts of memory from @prepare() in the GFP_KERNEL mode.
     93 *	[To work around these limitations, drivers may register suspend and
     94 *	hibernation notifiers to be executed before the freezing of tasks.]
     95 *
     96 * @complete: Undo the changes made by @prepare().  This method is executed for
     97 *	all kinds of resume transitions, following one of the resume callbacks:
     98 *	@resume(), @thaw(), @restore().  Also called if the state transition
     99 *	fails before the driver's suspend callback: @suspend(), @freeze() or
    100 *	@poweroff(), can be executed (e.g. if the suspend callback fails for one
    101 *	of the other devices that the PM core has unsuccessfully attempted to
    102 *	suspend earlier).
    103 *	The PM core executes subsystem-level @complete() after it has executed
    104 *	the appropriate resume callbacks for all devices.  If the corresponding
    105 *	@prepare() at the beginning of the suspend transition returned a
    106 *	positive number and the device was left in runtime suspend (without
    107 *	executing any suspend and resume callbacks for it), @complete() will be
    108 *	the only callback executed for the device during resume.  In that case,
    109 *	@complete() must be prepared to do whatever is necessary to ensure the
    110 *	proper functioning of the device after the system resume.  To this end,
    111 *	@complete() can check the power.direct_complete flag of the device to
    112 *	learn whether (unset) or not (set) the previous suspend and resume
    113 *	callbacks have been executed for it.
    114 *
    115 * @suspend: Executed before putting the system into a sleep state in which the
    116 *	contents of main memory are preserved.  The exact action to perform
    117 *	depends on the device's subsystem (PM domain, device type, class or bus
    118 *	type), but generally the device must be quiescent after subsystem-level
    119 *	@suspend() has returned, so that it doesn't do any I/O or DMA.
    120 *	Subsystem-level @suspend() is executed for all devices after invoking
    121 *	subsystem-level @prepare() for all of them.
    122 *
    123 * @suspend_late: Continue operations started by @suspend().  For a number of
    124 *	devices @suspend_late() may point to the same callback routine as the
    125 *	runtime suspend callback.
    126 *
    127 * @resume: Executed after waking the system up from a sleep state in which the
    128 *	contents of main memory were preserved.  The exact action to perform
    129 *	depends on the device's subsystem, but generally the driver is expected
    130 *	to start working again, responding to hardware events and software
    131 *	requests (the device itself may be left in a low-power state, waiting
    132 *	for a runtime resume to occur).  The state of the device at the time its
    133 *	driver's @resume() callback is run depends on the platform and subsystem
    134 *	the device belongs to.  On most platforms, there are no restrictions on
    135 *	availability of resources like clocks during @resume().
    136 *	Subsystem-level @resume() is executed for all devices after invoking
    137 *	subsystem-level @resume_noirq() for all of them.
    138 *
    139 * @resume_early: Prepare to execute @resume().  For a number of devices
    140 *	@resume_early() may point to the same callback routine as the runtime
    141 *	resume callback.
    142 *
    143 * @freeze: Hibernation-specific, executed before creating a hibernation image.
    144 *	Analogous to @suspend(), but it should not enable the device to signal
    145 *	wakeup events or change its power state.  The majority of subsystems
    146 *	(with the notable exception of the PCI bus type) expect the driver-level
    147 *	@freeze() to save the device settings in memory to be used by @restore()
    148 *	during the subsequent resume from hibernation.
    149 *	Subsystem-level @freeze() is executed for all devices after invoking
    150 *	subsystem-level @prepare() for all of them.
    151 *
    152 * @freeze_late: Continue operations started by @freeze().  Analogous to
    153 *	@suspend_late(), but it should not enable the device to signal wakeup
    154 *	events or change its power state.
    155 *
    156 * @thaw: Hibernation-specific, executed after creating a hibernation image OR
    157 *	if the creation of an image has failed.  Also executed after a failing
    158 *	attempt to restore the contents of main memory from such an image.
    159 *	Undo the changes made by the preceding @freeze(), so the device can be
    160 *	operated in the same way as immediately before the call to @freeze().
    161 *	Subsystem-level @thaw() is executed for all devices after invoking
    162 *	subsystem-level @thaw_noirq() for all of them.  It also may be executed
    163 *	directly after @freeze() in case of a transition error.
    164 *
    165 * @thaw_early: Prepare to execute @thaw().  Undo the changes made by the
    166 *	preceding @freeze_late().
    167 *
    168 * @poweroff: Hibernation-specific, executed after saving a hibernation image.
    169 *	Analogous to @suspend(), but it need not save the device's settings in
    170 *	memory.
    171 *	Subsystem-level @poweroff() is executed for all devices after invoking
    172 *	subsystem-level @prepare() for all of them.
    173 *
    174 * @poweroff_late: Continue operations started by @poweroff().  Analogous to
    175 *	@suspend_late(), but it need not save the device's settings in memory.
    176 *
    177 * @restore: Hibernation-specific, executed after restoring the contents of main
    178 *	memory from a hibernation image, analogous to @resume().
    179 *
    180 * @restore_early: Prepare to execute @restore(), analogous to @resume_early().
    181 *
    182 * @suspend_noirq: Complete the actions started by @suspend().  Carry out any
    183 *	additional operations required for suspending the device that might be
    184 *	racing with its driver's interrupt handler, which is guaranteed not to
    185 *	run while @suspend_noirq() is being executed.
    186 *	It generally is expected that the device will be in a low-power state
    187 *	(appropriate for the target system sleep state) after subsystem-level
    188 *	@suspend_noirq() has returned successfully.  If the device can generate
    189 *	system wakeup signals and is enabled to wake up the system, it should be
    190 *	configured to do so at that time.  However, depending on the platform
    191 *	and device's subsystem, @suspend() or @suspend_late() may be allowed to
    192 *	put the device into the low-power state and configure it to generate
    193 *	wakeup signals, in which case it generally is not necessary to define
    194 *	@suspend_noirq().
    195 *
    196 * @resume_noirq: Prepare for the execution of @resume() by carrying out any
    197 *	operations required for resuming the device that might be racing with
    198 *	its driver's interrupt handler, which is guaranteed not to run while
    199 *	@resume_noirq() is being executed.
    200 *
    201 * @freeze_noirq: Complete the actions started by @freeze().  Carry out any
    202 *	additional operations required for freezing the device that might be
    203 *	racing with its driver's interrupt handler, which is guaranteed not to
    204 *	run while @freeze_noirq() is being executed.
    205 *	The power state of the device should not be changed by either @freeze(),
    206 *	or @freeze_late(), or @freeze_noirq() and it should not be configured to
    207 *	signal system wakeup by any of these callbacks.
    208 *
    209 * @thaw_noirq: Prepare for the execution of @thaw() by carrying out any
    210 *	operations required for thawing the device that might be racing with its
    211 *	driver's interrupt handler, which is guaranteed not to run while
    212 *	@thaw_noirq() is being executed.
    213 *
    214 * @poweroff_noirq: Complete the actions started by @poweroff().  Analogous to
    215 *	@suspend_noirq(), but it need not save the device's settings in memory.
    216 *
    217 * @restore_noirq: Prepare for the execution of @restore() by carrying out any
    218 *	operations required for thawing the device that might be racing with its
    219 *	driver's interrupt handler, which is guaranteed not to run while
    220 *	@restore_noirq() is being executed.  Analogous to @resume_noirq().
    221 *
    222 * @runtime_suspend: Prepare the device for a condition in which it won't be
    223 *	able to communicate with the CPU(s) and RAM due to power management.
    224 *	This need not mean that the device should be put into a low-power state.
    225 *	For example, if the device is behind a link which is about to be turned
    226 *	off, the device may remain at full power.  If the device does go to low
    227 *	power and is capable of generating runtime wakeup events, remote wakeup
    228 *	(i.e., a hardware mechanism allowing the device to request a change of
    229 *	its power state via an interrupt) should be enabled for it.
    230 *
    231 * @runtime_resume: Put the device into the fully active state in response to a
    232 *	wakeup event generated by hardware or at the request of software.  If
    233 *	necessary, put the device into the full-power state and restore its
    234 *	registers, so that it is fully operational.
    235 *
    236 * @runtime_idle: Device appears to be inactive and it might be put into a
    237 *	low-power state if all of the necessary conditions are satisfied.
    238 *	Check these conditions, and return 0 if it's appropriate to let the PM
    239 *	core queue a suspend request for the device.
    240 *
    241 * Several device power state transitions are externally visible, affecting
    242 * the state of pending I/O queues and (for drivers that touch hardware)
    243 * interrupts, wakeups, DMA, and other hardware state.  There may also be
    244 * internal transitions to various low-power modes which are transparent
    245 * to the rest of the driver stack (such as a driver that's ON gating off
    246 * clocks which are not in active use).
    247 *
    248 * The externally visible transitions are handled with the help of callbacks
    249 * included in this structure in such a way that, typically, two levels of
    250 * callbacks are involved.  First, the PM core executes callbacks provided by PM
    251 * domains, device types, classes and bus types.  They are the subsystem-level
    252 * callbacks expected to execute callbacks provided by device drivers, although
    253 * they may choose not to do that.  If the driver callbacks are executed, they
    254 * have to collaborate with the subsystem-level callbacks to achieve the goals
    255 * appropriate for the given system transition, given transition phase and the
    256 * subsystem the device belongs to.
    257 *
    258 * All of the above callbacks, except for @complete(), return error codes.
    259 * However, the error codes returned by @resume(), @thaw(), @restore(),
    260 * @resume_noirq(), @thaw_noirq(), and @restore_noirq(), do not cause the PM
    261 * core to abort the resume transition during which they are returned.  The
    262 * error codes returned in those cases are only printed to the system logs for
    263 * debugging purposes.  Still, it is recommended that drivers only return error
    264 * codes from their resume methods in case of an unrecoverable failure (i.e.
    265 * when the device being handled refuses to resume and becomes unusable) to
    266 * allow the PM core to be modified in the future, so that it can avoid
    267 * attempting to handle devices that failed to resume and their children.
    268 *
    269 * It is allowed to unregister devices while the above callbacks are being
    270 * executed.  However, a callback routine MUST NOT try to unregister the device
    271 * it was called for, although it may unregister children of that device (for
    272 * example, if it detects that a child was unplugged while the system was
    273 * asleep).
    274 *
    275 * There also are callbacks related to runtime power management of devices.
    276 * Again, as a rule these callbacks are executed by the PM core for subsystems
    277 * (PM domains, device types, classes and bus types) and the subsystem-level
    278 * callbacks are expected to invoke the driver callbacks.  Moreover, the exact
    279 * actions to be performed by a device driver's callbacks generally depend on
    280 * the platform and subsystem the device belongs to.
    281 *
    282 * Refer to Documentation/power/runtime_pm.rst for more information about the
    283 * role of the @runtime_suspend(), @runtime_resume() and @runtime_idle()
    284 * callbacks in device runtime power management.
    285 */
    286struct dev_pm_ops {
    287	int (*prepare)(struct device *dev);
    288	void (*complete)(struct device *dev);
    289	int (*suspend)(struct device *dev);
    290	int (*resume)(struct device *dev);
    291	int (*freeze)(struct device *dev);
    292	int (*thaw)(struct device *dev);
    293	int (*poweroff)(struct device *dev);
    294	int (*restore)(struct device *dev);
    295	int (*suspend_late)(struct device *dev);
    296	int (*resume_early)(struct device *dev);
    297	int (*freeze_late)(struct device *dev);
    298	int (*thaw_early)(struct device *dev);
    299	int (*poweroff_late)(struct device *dev);
    300	int (*restore_early)(struct device *dev);
    301	int (*suspend_noirq)(struct device *dev);
    302	int (*resume_noirq)(struct device *dev);
    303	int (*freeze_noirq)(struct device *dev);
    304	int (*thaw_noirq)(struct device *dev);
    305	int (*poweroff_noirq)(struct device *dev);
    306	int (*restore_noirq)(struct device *dev);
    307	int (*runtime_suspend)(struct device *dev);
    308	int (*runtime_resume)(struct device *dev);
    309	int (*runtime_idle)(struct device *dev);
    310};
    311
    312#define SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
    313	.suspend = pm_sleep_ptr(suspend_fn), \
    314	.resume = pm_sleep_ptr(resume_fn), \
    315	.freeze = pm_sleep_ptr(suspend_fn), \
    316	.thaw = pm_sleep_ptr(resume_fn), \
    317	.poweroff = pm_sleep_ptr(suspend_fn), \
    318	.restore = pm_sleep_ptr(resume_fn),
    319
    320#define LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
    321	.suspend_late = pm_sleep_ptr(suspend_fn), \
    322	.resume_early = pm_sleep_ptr(resume_fn), \
    323	.freeze_late = pm_sleep_ptr(suspend_fn), \
    324	.thaw_early = pm_sleep_ptr(resume_fn), \
    325	.poweroff_late = pm_sleep_ptr(suspend_fn), \
    326	.restore_early = pm_sleep_ptr(resume_fn),
    327
    328#define NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
    329	.suspend_noirq = pm_sleep_ptr(suspend_fn), \
    330	.resume_noirq = pm_sleep_ptr(resume_fn), \
    331	.freeze_noirq = pm_sleep_ptr(suspend_fn), \
    332	.thaw_noirq = pm_sleep_ptr(resume_fn), \
    333	.poweroff_noirq = pm_sleep_ptr(suspend_fn), \
    334	.restore_noirq = pm_sleep_ptr(resume_fn),
    335
    336#define RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
    337	.runtime_suspend = suspend_fn, \
    338	.runtime_resume = resume_fn, \
    339	.runtime_idle = idle_fn,
    340
    341#ifdef CONFIG_PM_SLEEP
    342#define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
    343	SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
    344#else
    345#define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
    346#endif
    347
    348#ifdef CONFIG_PM_SLEEP
    349#define SET_LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
    350	LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
    351#else
    352#define SET_LATE_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
    353#endif
    354
    355#ifdef CONFIG_PM_SLEEP
    356#define SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
    357	NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
    358#else
    359#define SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
    360#endif
    361
    362#ifdef CONFIG_PM
    363#define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
    364	RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
    365#else
    366#define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
    367#endif
    368
    369#define _DEFINE_DEV_PM_OPS(name, \
    370			   suspend_fn, resume_fn, \
    371			   runtime_suspend_fn, runtime_resume_fn, idle_fn) \
    372const struct dev_pm_ops name = { \
    373	SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
    374	RUNTIME_PM_OPS(runtime_suspend_fn, runtime_resume_fn, idle_fn) \
    375}
    376
    377#ifdef CONFIG_PM
    378#define _EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn, runtime_suspend_fn, \
    379			   runtime_resume_fn, idle_fn, sec, ns)		\
    380	_DEFINE_DEV_PM_OPS(name, suspend_fn, resume_fn, runtime_suspend_fn, \
    381			   runtime_resume_fn, idle_fn); \
    382	__EXPORT_SYMBOL(name, sec, ns)
    383#else
    384#define _EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn, runtime_suspend_fn, \
    385			   runtime_resume_fn, idle_fn, sec, ns) \
    386static __maybe_unused _DEFINE_DEV_PM_OPS(__static_##name, suspend_fn, \
    387					 resume_fn, runtime_suspend_fn, \
    388					 runtime_resume_fn, idle_fn)
    389#endif
    390
    391/*
    392 * Use this if you want to use the same suspend and resume callbacks for suspend
    393 * to RAM and hibernation.
    394 *
    395 * If the underlying dev_pm_ops struct symbol has to be exported, use
    396 * EXPORT_SIMPLE_DEV_PM_OPS() or EXPORT_GPL_SIMPLE_DEV_PM_OPS() instead.
    397 */
    398#define DEFINE_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
    399	_DEFINE_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL)
    400
    401#define EXPORT_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
    402	_EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL, "", "")
    403#define EXPORT_GPL_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
    404	_EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL, "_gpl", "")
    405#define EXPORT_NS_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn, ns)	\
    406	_EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL, "", #ns)
    407#define EXPORT_NS_GPL_SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn, ns)	\
    408	_EXPORT_DEV_PM_OPS(name, suspend_fn, resume_fn, NULL, NULL, NULL, "_gpl", #ns)
    409
    410/* Deprecated. Use DEFINE_SIMPLE_DEV_PM_OPS() instead. */
    411#define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
    412const struct dev_pm_ops __maybe_unused name = { \
    413	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
    414}
    415
    416/*
    417 * Use this for defining a set of PM operations to be used in all situations
    418 * (system suspend, hibernation or runtime PM).
    419 * NOTE: In general, system suspend callbacks, .suspend() and .resume(), should
    420 * be different from the corresponding runtime PM callbacks, .runtime_suspend(),
    421 * and .runtime_resume(), because .runtime_suspend() always works on an already
    422 * quiescent device, while .suspend() should assume that the device may be doing
    423 * something when it is called (it should ensure that the device will be
    424 * quiescent after it has returned).  Therefore it's better to point the "late"
    425 * suspend and "early" resume callback pointers, .suspend_late() and
    426 * .resume_early(), to the same routines as .runtime_suspend() and
    427 * .runtime_resume(), respectively (and analogously for hibernation).
    428 *
    429 * Deprecated. You most likely don't want this macro. Use
    430 * DEFINE_RUNTIME_DEV_PM_OPS() instead.
    431 */
    432#define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
    433const struct dev_pm_ops __maybe_unused name = { \
    434	SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
    435	SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
    436}
    437
    438#define pm_ptr(_ptr) PTR_IF(IS_ENABLED(CONFIG_PM), (_ptr))
    439#define pm_sleep_ptr(_ptr) PTR_IF(IS_ENABLED(CONFIG_PM_SLEEP), (_ptr))
    440
    441/*
    442 * PM_EVENT_ messages
    443 *
    444 * The following PM_EVENT_ messages are defined for the internal use of the PM
    445 * core, in order to provide a mechanism allowing the high level suspend and
    446 * hibernation code to convey the necessary information to the device PM core
    447 * code:
    448 *
    449 * ON		No transition.
    450 *
    451 * FREEZE	System is going to hibernate, call ->prepare() and ->freeze()
    452 *		for all devices.
    453 *
    454 * SUSPEND	System is going to suspend, call ->prepare() and ->suspend()
    455 *		for all devices.
    456 *
    457 * HIBERNATE	Hibernation image has been saved, call ->prepare() and
    458 *		->poweroff() for all devices.
    459 *
    460 * QUIESCE	Contents of main memory are going to be restored from a (loaded)
    461 *		hibernation image, call ->prepare() and ->freeze() for all
    462 *		devices.
    463 *
    464 * RESUME	System is resuming, call ->resume() and ->complete() for all
    465 *		devices.
    466 *
    467 * THAW		Hibernation image has been created, call ->thaw() and
    468 *		->complete() for all devices.
    469 *
    470 * RESTORE	Contents of main memory have been restored from a hibernation
    471 *		image, call ->restore() and ->complete() for all devices.
    472 *
    473 * RECOVER	Creation of a hibernation image or restoration of the main
    474 *		memory contents from a hibernation image has failed, call
    475 *		->thaw() and ->complete() for all devices.
    476 *
    477 * The following PM_EVENT_ messages are defined for internal use by
    478 * kernel subsystems.  They are never issued by the PM core.
    479 *
    480 * USER_SUSPEND		Manual selective suspend was issued by userspace.
    481 *
    482 * USER_RESUME		Manual selective resume was issued by userspace.
    483 *
    484 * REMOTE_WAKEUP	Remote-wakeup request was received from the device.
    485 *
    486 * AUTO_SUSPEND		Automatic (device idle) runtime suspend was
    487 *			initiated by the subsystem.
    488 *
    489 * AUTO_RESUME		Automatic (device needed) runtime resume was
    490 *			requested by a driver.
    491 */
    492
    493#define PM_EVENT_INVALID	(-1)
    494#define PM_EVENT_ON		0x0000
    495#define PM_EVENT_FREEZE		0x0001
    496#define PM_EVENT_SUSPEND	0x0002
    497#define PM_EVENT_HIBERNATE	0x0004
    498#define PM_EVENT_QUIESCE	0x0008
    499#define PM_EVENT_RESUME		0x0010
    500#define PM_EVENT_THAW		0x0020
    501#define PM_EVENT_RESTORE	0x0040
    502#define PM_EVENT_RECOVER	0x0080
    503#define PM_EVENT_USER		0x0100
    504#define PM_EVENT_REMOTE		0x0200
    505#define PM_EVENT_AUTO		0x0400
    506
    507#define PM_EVENT_SLEEP		(PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
    508#define PM_EVENT_USER_SUSPEND	(PM_EVENT_USER | PM_EVENT_SUSPEND)
    509#define PM_EVENT_USER_RESUME	(PM_EVENT_USER | PM_EVENT_RESUME)
    510#define PM_EVENT_REMOTE_RESUME	(PM_EVENT_REMOTE | PM_EVENT_RESUME)
    511#define PM_EVENT_AUTO_SUSPEND	(PM_EVENT_AUTO | PM_EVENT_SUSPEND)
    512#define PM_EVENT_AUTO_RESUME	(PM_EVENT_AUTO | PM_EVENT_RESUME)
    513
    514#define PMSG_INVALID	((struct pm_message){ .event = PM_EVENT_INVALID, })
    515#define PMSG_ON		((struct pm_message){ .event = PM_EVENT_ON, })
    516#define PMSG_FREEZE	((struct pm_message){ .event = PM_EVENT_FREEZE, })
    517#define PMSG_QUIESCE	((struct pm_message){ .event = PM_EVENT_QUIESCE, })
    518#define PMSG_SUSPEND	((struct pm_message){ .event = PM_EVENT_SUSPEND, })
    519#define PMSG_HIBERNATE	((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
    520#define PMSG_RESUME	((struct pm_message){ .event = PM_EVENT_RESUME, })
    521#define PMSG_THAW	((struct pm_message){ .event = PM_EVENT_THAW, })
    522#define PMSG_RESTORE	((struct pm_message){ .event = PM_EVENT_RESTORE, })
    523#define PMSG_RECOVER	((struct pm_message){ .event = PM_EVENT_RECOVER, })
    524#define PMSG_USER_SUSPEND	((struct pm_message) \
    525					{ .event = PM_EVENT_USER_SUSPEND, })
    526#define PMSG_USER_RESUME	((struct pm_message) \
    527					{ .event = PM_EVENT_USER_RESUME, })
    528#define PMSG_REMOTE_RESUME	((struct pm_message) \
    529					{ .event = PM_EVENT_REMOTE_RESUME, })
    530#define PMSG_AUTO_SUSPEND	((struct pm_message) \
    531					{ .event = PM_EVENT_AUTO_SUSPEND, })
    532#define PMSG_AUTO_RESUME	((struct pm_message) \
    533					{ .event = PM_EVENT_AUTO_RESUME, })
    534
    535#define PMSG_IS_AUTO(msg)	(((msg).event & PM_EVENT_AUTO) != 0)
    536
    537/*
    538 * Device run-time power management status.
    539 *
    540 * These status labels are used internally by the PM core to indicate the
    541 * current status of a device with respect to the PM core operations.  They do
    542 * not reflect the actual power state of the device or its status as seen by the
    543 * driver.
    544 *
    545 * RPM_ACTIVE		Device is fully operational.  Indicates that the device
    546 *			bus type's ->runtime_resume() callback has completed
    547 *			successfully.
    548 *
    549 * RPM_SUSPENDED	Device bus type's ->runtime_suspend() callback has
    550 *			completed successfully.  The device is regarded as
    551 *			suspended.
    552 *
    553 * RPM_RESUMING		Device bus type's ->runtime_resume() callback is being
    554 *			executed.
    555 *
    556 * RPM_SUSPENDING	Device bus type's ->runtime_suspend() callback is being
    557 *			executed.
    558 */
    559
    560enum rpm_status {
    561	RPM_INVALID = -1,
    562	RPM_ACTIVE = 0,
    563	RPM_RESUMING,
    564	RPM_SUSPENDED,
    565	RPM_SUSPENDING,
    566};
    567
    568/*
    569 * Device run-time power management request types.
    570 *
    571 * RPM_REQ_NONE		Do nothing.
    572 *
    573 * RPM_REQ_IDLE		Run the device bus type's ->runtime_idle() callback
    574 *
    575 * RPM_REQ_SUSPEND	Run the device bus type's ->runtime_suspend() callback
    576 *
    577 * RPM_REQ_AUTOSUSPEND	Same as RPM_REQ_SUSPEND, but not until the device has
    578 *			been inactive for as long as power.autosuspend_delay
    579 *
    580 * RPM_REQ_RESUME	Run the device bus type's ->runtime_resume() callback
    581 */
    582
    583enum rpm_request {
    584	RPM_REQ_NONE = 0,
    585	RPM_REQ_IDLE,
    586	RPM_REQ_SUSPEND,
    587	RPM_REQ_AUTOSUSPEND,
    588	RPM_REQ_RESUME,
    589};
    590
    591struct wakeup_source;
    592struct wake_irq;
    593struct pm_domain_data;
    594
    595struct pm_subsys_data {
    596	spinlock_t lock;
    597	unsigned int refcount;
    598#ifdef CONFIG_PM_CLK
    599	unsigned int clock_op_might_sleep;
    600	struct mutex clock_mutex;
    601	struct list_head clock_list;
    602#endif
    603#ifdef CONFIG_PM_GENERIC_DOMAINS
    604	struct pm_domain_data *domain_data;
    605#endif
    606};
    607
    608/*
    609 * Driver flags to control system suspend/resume behavior.
    610 *
    611 * These flags can be set by device drivers at the probe time.  They need not be
    612 * cleared by the drivers as the driver core will take care of that.
    613 *
    614 * NO_DIRECT_COMPLETE: Do not apply direct-complete optimization to the device.
    615 * SMART_PREPARE: Take the driver ->prepare callback return value into account.
    616 * SMART_SUSPEND: Avoid resuming the device from runtime suspend.
    617 * MAY_SKIP_RESUME: Allow driver "noirq" and "early" callbacks to be skipped.
    618 *
    619 * See Documentation/driver-api/pm/devices.rst for details.
    620 */
    621#define DPM_FLAG_NO_DIRECT_COMPLETE	BIT(0)
    622#define DPM_FLAG_SMART_PREPARE		BIT(1)
    623#define DPM_FLAG_SMART_SUSPEND		BIT(2)
    624#define DPM_FLAG_MAY_SKIP_RESUME	BIT(3)
    625
    626struct dev_pm_info {
    627	pm_message_t		power_state;
    628	unsigned int		can_wakeup:1;
    629	unsigned int		async_suspend:1;
    630	bool			in_dpm_list:1;	/* Owned by the PM core */
    631	bool			is_prepared:1;	/* Owned by the PM core */
    632	bool			is_suspended:1;	/* Ditto */
    633	bool			is_noirq_suspended:1;
    634	bool			is_late_suspended:1;
    635	bool			no_pm:1;
    636	bool			early_init:1;	/* Owned by the PM core */
    637	bool			direct_complete:1;	/* Owned by the PM core */
    638	u32			driver_flags;
    639	spinlock_t		lock;
    640#ifdef CONFIG_PM_SLEEP
    641	struct list_head	entry;
    642	struct completion	completion;
    643	struct wakeup_source	*wakeup;
    644	bool			wakeup_path:1;
    645	bool			syscore:1;
    646	bool			no_pm_callbacks:1;	/* Owned by the PM core */
    647	unsigned int		must_resume:1;	/* Owned by the PM core */
    648	unsigned int		may_skip_resume:1;	/* Set by subsystems */
    649#else
    650	unsigned int		should_wakeup:1;
    651#endif
    652#ifdef CONFIG_PM
    653	struct hrtimer		suspend_timer;
    654	u64			timer_expires;
    655	struct work_struct	work;
    656	wait_queue_head_t	wait_queue;
    657	struct wake_irq		*wakeirq;
    658	atomic_t		usage_count;
    659	atomic_t		child_count;
    660	unsigned int		disable_depth:3;
    661	unsigned int		idle_notification:1;
    662	unsigned int		request_pending:1;
    663	unsigned int		deferred_resume:1;
    664	unsigned int		needs_force_resume:1;
    665	unsigned int		runtime_auto:1;
    666	bool			ignore_children:1;
    667	unsigned int		no_callbacks:1;
    668	unsigned int		irq_safe:1;
    669	unsigned int		use_autosuspend:1;
    670	unsigned int		timer_autosuspends:1;
    671	unsigned int		memalloc_noio:1;
    672	unsigned int		links_count;
    673	enum rpm_request	request;
    674	enum rpm_status		runtime_status;
    675	enum rpm_status		last_status;
    676	int			runtime_error;
    677	int			autosuspend_delay;
    678	u64			last_busy;
    679	u64			active_time;
    680	u64			suspended_time;
    681	u64			accounting_timestamp;
    682#endif
    683	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */
    684	void (*set_latency_tolerance)(struct device *, s32);
    685	struct dev_pm_qos	*qos;
    686};
    687
    688extern int dev_pm_get_subsys_data(struct device *dev);
    689extern void dev_pm_put_subsys_data(struct device *dev);
    690
    691/**
    692 * struct dev_pm_domain - power management domain representation.
    693 *
    694 * @ops: Power management operations associated with this domain.
    695 * @start: Called when a user needs to start the device via the domain.
    696 * @detach: Called when removing a device from the domain.
    697 * @activate: Called before executing probe routines for bus types and drivers.
    698 * @sync: Called after successful driver probe.
    699 * @dismiss: Called after unsuccessful driver probe and after driver removal.
    700 *
    701 * Power domains provide callbacks that are executed during system suspend,
    702 * hibernation, system resume and during runtime PM transitions instead of
    703 * subsystem-level and driver-level callbacks.
    704 */
    705struct dev_pm_domain {
    706	struct dev_pm_ops	ops;
    707	int (*start)(struct device *dev);
    708	void (*detach)(struct device *dev, bool power_off);
    709	int (*activate)(struct device *dev);
    710	void (*sync)(struct device *dev);
    711	void (*dismiss)(struct device *dev);
    712};
    713
    714/*
    715 * The PM_EVENT_ messages are also used by drivers implementing the legacy
    716 * suspend framework, based on the ->suspend() and ->resume() callbacks common
    717 * for suspend and hibernation transitions, according to the rules below.
    718 */
    719
    720/* Necessary, because several drivers use PM_EVENT_PRETHAW */
    721#define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
    722
    723/*
    724 * One transition is triggered by resume(), after a suspend() call; the
    725 * message is implicit:
    726 *
    727 * ON		Driver starts working again, responding to hardware events
    728 *		and software requests.  The hardware may have gone through
    729 *		a power-off reset, or it may have maintained state from the
    730 *		previous suspend() which the driver will rely on while
    731 *		resuming.  On most platforms, there are no restrictions on
    732 *		availability of resources like clocks during resume().
    733 *
    734 * Other transitions are triggered by messages sent using suspend().  All
    735 * these transitions quiesce the driver, so that I/O queues are inactive.
    736 * That commonly entails turning off IRQs and DMA; there may be rules
    737 * about how to quiesce that are specific to the bus or the device's type.
    738 * (For example, network drivers mark the link state.)  Other details may
    739 * differ according to the message:
    740 *
    741 * SUSPEND	Quiesce, enter a low power device state appropriate for
    742 *		the upcoming system state (such as PCI_D3hot), and enable
    743 *		wakeup events as appropriate.
    744 *
    745 * HIBERNATE	Enter a low power device state appropriate for the hibernation
    746 *		state (eg. ACPI S4) and enable wakeup events as appropriate.
    747 *
    748 * FREEZE	Quiesce operations so that a consistent image can be saved;
    749 *		but do NOT otherwise enter a low power device state, and do
    750 *		NOT emit system wakeup events.
    751 *
    752 * PRETHAW	Quiesce as if for FREEZE; additionally, prepare for restoring
    753 *		the system from a snapshot taken after an earlier FREEZE.
    754 *		Some drivers will need to reset their hardware state instead
    755 *		of preserving it, to ensure that it's never mistaken for the
    756 *		state which that earlier snapshot had set up.
    757 *
    758 * A minimally power-aware driver treats all messages as SUSPEND, fully
    759 * reinitializes its device during resume() -- whether or not it was reset
    760 * during the suspend/resume cycle -- and can't issue wakeup events.
    761 *
    762 * More power-aware drivers may also use low power states at runtime as
    763 * well as during system sleep states like PM_SUSPEND_STANDBY.  They may
    764 * be able to use wakeup events to exit from runtime low-power states,
    765 * or from system low-power states such as standby or suspend-to-RAM.
    766 */
    767
    768#ifdef CONFIG_PM_SLEEP
    769extern void device_pm_lock(void);
    770extern void dpm_resume_start(pm_message_t state);
    771extern void dpm_resume_end(pm_message_t state);
    772extern void dpm_resume_noirq(pm_message_t state);
    773extern void dpm_resume_early(pm_message_t state);
    774extern void dpm_resume(pm_message_t state);
    775extern void dpm_complete(pm_message_t state);
    776
    777extern void device_pm_unlock(void);
    778extern int dpm_suspend_end(pm_message_t state);
    779extern int dpm_suspend_start(pm_message_t state);
    780extern int dpm_suspend_noirq(pm_message_t state);
    781extern int dpm_suspend_late(pm_message_t state);
    782extern int dpm_suspend(pm_message_t state);
    783extern int dpm_prepare(pm_message_t state);
    784
    785extern void __suspend_report_result(const char *function, struct device *dev, void *fn, int ret);
    786
    787#define suspend_report_result(dev, fn, ret)				\
    788	do {								\
    789		__suspend_report_result(__func__, dev, fn, ret);	\
    790	} while (0)
    791
    792extern int device_pm_wait_for_dev(struct device *sub, struct device *dev);
    793extern void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *));
    794
    795extern int pm_generic_prepare(struct device *dev);
    796extern int pm_generic_suspend_late(struct device *dev);
    797extern int pm_generic_suspend_noirq(struct device *dev);
    798extern int pm_generic_suspend(struct device *dev);
    799extern int pm_generic_resume_early(struct device *dev);
    800extern int pm_generic_resume_noirq(struct device *dev);
    801extern int pm_generic_resume(struct device *dev);
    802extern int pm_generic_freeze_noirq(struct device *dev);
    803extern int pm_generic_freeze_late(struct device *dev);
    804extern int pm_generic_freeze(struct device *dev);
    805extern int pm_generic_thaw_noirq(struct device *dev);
    806extern int pm_generic_thaw_early(struct device *dev);
    807extern int pm_generic_thaw(struct device *dev);
    808extern int pm_generic_restore_noirq(struct device *dev);
    809extern int pm_generic_restore_early(struct device *dev);
    810extern int pm_generic_restore(struct device *dev);
    811extern int pm_generic_poweroff_noirq(struct device *dev);
    812extern int pm_generic_poweroff_late(struct device *dev);
    813extern int pm_generic_poweroff(struct device *dev);
    814extern void pm_generic_complete(struct device *dev);
    815
    816extern bool dev_pm_skip_resume(struct device *dev);
    817extern bool dev_pm_skip_suspend(struct device *dev);
    818
    819#else /* !CONFIG_PM_SLEEP */
    820
    821#define device_pm_lock() do {} while (0)
    822#define device_pm_unlock() do {} while (0)
    823
    824static inline int dpm_suspend_start(pm_message_t state)
    825{
    826	return 0;
    827}
    828
    829#define suspend_report_result(dev, fn, ret)	do {} while (0)
    830
    831static inline int device_pm_wait_for_dev(struct device *a, struct device *b)
    832{
    833	return 0;
    834}
    835
    836static inline void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
    837{
    838}
    839
    840#define pm_generic_prepare		NULL
    841#define pm_generic_suspend_late		NULL
    842#define pm_generic_suspend_noirq	NULL
    843#define pm_generic_suspend		NULL
    844#define pm_generic_resume_early		NULL
    845#define pm_generic_resume_noirq		NULL
    846#define pm_generic_resume		NULL
    847#define pm_generic_freeze_noirq		NULL
    848#define pm_generic_freeze_late		NULL
    849#define pm_generic_freeze		NULL
    850#define pm_generic_thaw_noirq		NULL
    851#define pm_generic_thaw_early		NULL
    852#define pm_generic_thaw			NULL
    853#define pm_generic_restore_noirq	NULL
    854#define pm_generic_restore_early	NULL
    855#define pm_generic_restore		NULL
    856#define pm_generic_poweroff_noirq	NULL
    857#define pm_generic_poweroff_late	NULL
    858#define pm_generic_poweroff		NULL
    859#define pm_generic_complete		NULL
    860#endif /* !CONFIG_PM_SLEEP */
    861
    862/* How to reorder dpm_list after device_move() */
    863enum dpm_order {
    864	DPM_ORDER_NONE,
    865	DPM_ORDER_DEV_AFTER_PARENT,
    866	DPM_ORDER_PARENT_BEFORE_DEV,
    867	DPM_ORDER_DEV_LAST,
    868};
    869
    870#endif /* _LINUX_PM_H */