![Rafael J. Wysocki](/assets/img/avatar_default.png)
Introduce 'struct pm_ops' and 'struct pm_ext_ops' ('ext' meaning 'extended') representing suspend and hibernation operations for bus types, device classes, device types and device drivers. Modify the PM core to use 'struct pm_ops' and 'struct pm_ext_ops' objects, if defined, instead of the ->suspend(), ->resume(), ->suspend_late(), and ->resume_early() callbacks (the old callbacks will be considered as legacy and gradually phased out). The main purpose of doing this is to separate suspend (aka S2RAM and standby) callbacks from hibernation callbacks in such a way that the new callbacks won't take arguments and the semantics of each of them will be clearly specified. This has been requested for multiple times by many people, including Linus himself, and the reason is that within the current scheme if ->resume() is called, for example, it's difficult to say why it's been called (ie. is it a resume from RAM or from hibernation or a suspend/hibernation failure etc.?). The second purpose is to make the suspend/hibernation callbacks more flexible so that device drivers can handle more than they can within the current scheme. For example, some drivers may need to prevent new children of the device from being registered before their ->suspend() callbacks are executed or they may want to carry out some operations requiring the availability of some other devices, not directly bound via the parent-child relationship, in order to prepare for the execution of ->suspend(), etc. Ultimately, we'd like to stop using the freezing of tasks for suspend and therefore the drivers' suspend/hibernation code will have to take care of the handling of the user space during suspend/hibernation. That, in turn, would be difficult within the current scheme, without the new ->prepare() and ->complete() callbacks. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
485 lines
18 KiB
C
485 lines
18 KiB
C
/*
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* pm.h - Power management interface
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*
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* Copyright (C) 2000 Andrew Henroid
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#ifndef _LINUX_PM_H
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#define _LINUX_PM_H
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#include <linux/list.h>
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#include <asm/atomic.h>
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#include <asm/errno.h>
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/*
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* Power management requests... these are passed to pm_send_all() and friends.
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*
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* these functions are old and deprecated, see below.
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*/
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typedef int __bitwise pm_request_t;
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#define PM_SUSPEND ((__force pm_request_t) 1) /* enter D1-D3 */
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#define PM_RESUME ((__force pm_request_t) 2) /* enter D0 */
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/*
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* Device types... these are passed to pm_register
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*/
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typedef int __bitwise pm_dev_t;
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#define PM_UNKNOWN_DEV ((__force pm_dev_t) 0) /* generic */
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#define PM_SYS_DEV ((__force pm_dev_t) 1) /* system device (fan, KB controller, ...) */
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#define PM_PCI_DEV ((__force pm_dev_t) 2) /* PCI device */
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#define PM_USB_DEV ((__force pm_dev_t) 3) /* USB device */
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#define PM_SCSI_DEV ((__force pm_dev_t) 4) /* SCSI device */
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#define PM_ISA_DEV ((__force pm_dev_t) 5) /* ISA device */
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#define PM_MTD_DEV ((__force pm_dev_t) 6) /* Memory Technology Device */
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/*
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* System device hardware ID (PnP) values
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*/
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enum
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{
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PM_SYS_UNKNOWN = 0x00000000, /* generic */
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PM_SYS_KBC = 0x41d00303, /* keyboard controller */
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PM_SYS_COM = 0x41d00500, /* serial port */
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PM_SYS_IRDA = 0x41d00510, /* IRDA controller */
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PM_SYS_FDC = 0x41d00700, /* floppy controller */
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PM_SYS_VGA = 0x41d00900, /* VGA controller */
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PM_SYS_PCMCIA = 0x41d00e00, /* PCMCIA controller */
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};
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/*
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* Device identifier
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*/
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#define PM_PCI_ID(dev) ((dev)->bus->number << 16 | (dev)->devfn)
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/*
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* Request handler callback
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*/
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struct pm_dev;
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typedef int (*pm_callback)(struct pm_dev *dev, pm_request_t rqst, void *data);
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/*
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* Dynamic device information
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*/
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struct pm_dev
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{
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pm_dev_t type;
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unsigned long id;
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pm_callback callback;
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void *data;
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unsigned long flags;
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unsigned long state;
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unsigned long prev_state;
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struct list_head entry;
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};
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/* Functions above this comment are list-based old-style power
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* management. Please avoid using them. */
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/*
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* Callbacks for platform drivers to implement.
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*/
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extern void (*pm_idle)(void);
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extern void (*pm_power_off)(void);
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extern void (*pm_power_off_prepare)(void);
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/*
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* Device power management
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*/
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struct device;
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typedef struct pm_message {
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int event;
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} pm_message_t;
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/**
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* struct pm_ops - device PM callbacks
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*
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* Several driver power state transitions are externally visible, affecting
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* the state of pending I/O queues and (for drivers that touch hardware)
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* interrupts, wakeups, DMA, and other hardware state. There may also be
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* internal transitions to various low power modes, which are transparent
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* to the rest of the driver stack (such as a driver that's ON gating off
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* clocks which are not in active use).
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*
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* The externally visible transitions are handled with the help of the following
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* callbacks included in this structure:
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*
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* @prepare: Prepare the device for the upcoming transition, but do NOT change
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* its hardware state. Prevent new children of the device from being
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* registered after @prepare() returns (the driver's subsystem and
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* generally the rest of the kernel is supposed to prevent new calls to the
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* probe method from being made too once @prepare() has succeeded). If
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* @prepare() detects a situation it cannot handle (e.g. registration of a
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* child already in progress), it may return -EAGAIN, so that the PM core
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* can execute it once again (e.g. after the new child has been registered)
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* to recover from the race condition. This method is executed for all
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* kinds of suspend transitions and is followed by one of the suspend
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* callbacks: @suspend(), @freeze(), or @poweroff().
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* The PM core executes @prepare() for all devices before starting to
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* execute suspend callbacks for any of them, so drivers may assume all of
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* the other devices to be present and functional while @prepare() is being
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* executed. In particular, it is safe to make GFP_KERNEL memory
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* allocations from within @prepare(). However, drivers may NOT assume
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* anything about the availability of the user space at that time and it
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* is not correct to request firmware from within @prepare() (it's too
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* late to do that). [To work around this limitation, drivers may
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* register suspend and hibernation notifiers that are executed before the
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* freezing of tasks.]
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*
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* @complete: Undo the changes made by @prepare(). This method is executed for
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* all kinds of resume transitions, following one of the resume callbacks:
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* @resume(), @thaw(), @restore(). Also called if the state transition
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* fails before the driver's suspend callback (@suspend(), @freeze(),
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* @poweroff()) can be executed (e.g. if the suspend callback fails for one
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* of the other devices that the PM core has unsuccessfully attempted to
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* suspend earlier).
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* The PM core executes @complete() after it has executed the appropriate
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* resume callback for all devices.
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*
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* @suspend: Executed before putting the system into a sleep state in which the
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* contents of main memory are preserved. Quiesce the device, put it into
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* a low power state appropriate for the upcoming system state (such as
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* PCI_D3hot), and enable wakeup events as appropriate.
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*
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* @resume: Executed after waking the system up from a sleep state in which the
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* contents of main memory were preserved. Put the device into the
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* appropriate state, according to the information saved in memory by the
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* preceding @suspend(). The driver starts working again, responding to
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* hardware events and software requests. The hardware may have gone
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* through a power-off reset, or it may have maintained state from the
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* previous suspend() which the driver may rely on while resuming. On most
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* platforms, there are no restrictions on availability of resources like
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* clocks during @resume().
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*
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* @freeze: Hibernation-specific, executed before creating a hibernation image.
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* Quiesce operations so that a consistent image can be created, but do NOT
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* otherwise put the device into a low power device state and do NOT emit
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* system wakeup events. Save in main memory the device settings to be
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* used by @restore() during the subsequent resume from hibernation or by
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* the subsequent @thaw(), if the creation of the image or the restoration
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* of main memory contents from it fails.
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*
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* @thaw: Hibernation-specific, executed after creating a hibernation image OR
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* if the creation of the image fails. Also executed after a failing
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* attempt to restore the contents of main memory from such an image.
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* Undo the changes made by the preceding @freeze(), so the device can be
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* operated in the same way as immediately before the call to @freeze().
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*
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* @poweroff: Hibernation-specific, executed after saving a hibernation image.
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* Quiesce the device, put it into a low power state appropriate for the
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* upcoming system state (such as PCI_D3hot), and enable wakeup events as
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* appropriate.
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*
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* @restore: Hibernation-specific, executed after restoring the contents of main
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* memory from a hibernation image. Driver starts working again,
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* responding to hardware events and software requests. Drivers may NOT
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* make ANY assumptions about the hardware state right prior to @restore().
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* On most platforms, there are no restrictions on availability of
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* resources like clocks during @restore().
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*
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* All of the above callbacks, except for @complete(), return error codes.
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* However, the error codes returned by the resume operations, @resume(),
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* @thaw(), and @restore(), do not cause the PM core to abort the resume
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* transition during which they are returned. The error codes returned in
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* that cases are only printed by the PM core to the system logs for debugging
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* purposes. Still, it is recommended that drivers only return error codes
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* from their resume methods in case of an unrecoverable failure (i.e. when the
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* device being handled refuses to resume and becomes unusable) to allow us to
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* modify the PM core in the future, so that it can avoid attempting to handle
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* devices that failed to resume and their children.
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*
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* It is allowed to unregister devices while the above callbacks are being
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* executed. However, it is not allowed to unregister a device from within any
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* of its own callbacks.
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*/
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struct pm_ops {
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int (*prepare)(struct device *dev);
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void (*complete)(struct device *dev);
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int (*suspend)(struct device *dev);
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int (*resume)(struct device *dev);
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int (*freeze)(struct device *dev);
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int (*thaw)(struct device *dev);
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int (*poweroff)(struct device *dev);
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int (*restore)(struct device *dev);
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};
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/**
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* struct pm_ext_ops - extended device PM callbacks
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*
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* Some devices require certain operations related to suspend and hibernation
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* to be carried out with interrupts disabled. Thus, 'struct pm_ext_ops' below
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* is defined, adding callbacks to be executed with interrupts disabled to
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* 'struct pm_ops'.
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*
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* The following callbacks included in 'struct pm_ext_ops' are executed with
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* the nonboot CPUs switched off and with interrupts disabled on the only
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* functional CPU. They also are executed with the PM core list of devices
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* locked, so they must NOT unregister any devices.
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*
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* @suspend_noirq: Complete the operations of ->suspend() by carrying out any
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* actions required for suspending the device that need interrupts to be
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* disabled
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*
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* @resume_noirq: Prepare for the execution of ->resume() by carrying out any
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* actions required for resuming the device that need interrupts to be
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* disabled
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*
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* @freeze_noirq: Complete the operations of ->freeze() by carrying out any
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* actions required for freezing the device that need interrupts to be
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* disabled
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*
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* @thaw_noirq: Prepare for the execution of ->thaw() by carrying out any
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* actions required for thawing the device that need interrupts to be
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* disabled
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*
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* @poweroff_noirq: Complete the operations of ->poweroff() by carrying out any
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* actions required for handling the device that need interrupts to be
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* disabled
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*
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* @restore_noirq: Prepare for the execution of ->restore() by carrying out any
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* actions required for restoring the operations of the device that need
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* interrupts to be disabled
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*
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* All of the above callbacks return error codes, but the error codes returned
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* by the resume operations, @resume_noirq(), @thaw_noirq(), and
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* @restore_noirq(), do not cause the PM core to abort the resume transition
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* during which they are returned. The error codes returned in that cases are
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* only printed by the PM core to the system logs for debugging purposes.
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* Still, as stated above, it is recommended that drivers only return error
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* codes from their resume methods if the device being handled fails to resume
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* and is not usable any more.
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*/
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struct pm_ext_ops {
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struct pm_ops base;
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int (*suspend_noirq)(struct device *dev);
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int (*resume_noirq)(struct device *dev);
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int (*freeze_noirq)(struct device *dev);
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int (*thaw_noirq)(struct device *dev);
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int (*poweroff_noirq)(struct device *dev);
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int (*restore_noirq)(struct device *dev);
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};
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/**
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* PM_EVENT_ messages
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*
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* The following PM_EVENT_ messages are defined for the internal use of the PM
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* core, in order to provide a mechanism allowing the high level suspend and
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* hibernation code to convey the necessary information to the device PM core
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* code:
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*
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* ON No transition.
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*
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* FREEZE System is going to hibernate, call ->prepare() and ->freeze()
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* for all devices.
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*
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* SUSPEND System is going to suspend, call ->prepare() and ->suspend()
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* for all devices.
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*
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* HIBERNATE Hibernation image has been saved, call ->prepare() and
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* ->poweroff() for all devices.
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*
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* QUIESCE Contents of main memory are going to be restored from a (loaded)
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* hibernation image, call ->prepare() and ->freeze() for all
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* devices.
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*
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* RESUME System is resuming, call ->resume() and ->complete() for all
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* devices.
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*
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* THAW Hibernation image has been created, call ->thaw() and
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* ->complete() for all devices.
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*
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* RESTORE Contents of main memory have been restored from a hibernation
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* image, call ->restore() and ->complete() for all devices.
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*
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* RECOVER Creation of a hibernation image or restoration of the main
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* memory contents from a hibernation image has failed, call
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* ->thaw() and ->complete() for all devices.
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*/
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#define PM_EVENT_ON 0x0000
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#define PM_EVENT_FREEZE 0x0001
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#define PM_EVENT_SUSPEND 0x0002
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#define PM_EVENT_HIBERNATE 0x0004
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#define PM_EVENT_QUIESCE 0x0008
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#define PM_EVENT_RESUME 0x0010
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#define PM_EVENT_THAW 0x0020
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#define PM_EVENT_RESTORE 0x0040
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#define PM_EVENT_RECOVER 0x0080
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#define PM_EVENT_SLEEP (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
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#define PMSG_FREEZE ((struct pm_message){ .event = PM_EVENT_FREEZE, })
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#define PMSG_QUIESCE ((struct pm_message){ .event = PM_EVENT_QUIESCE, })
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#define PMSG_SUSPEND ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
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#define PMSG_HIBERNATE ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
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#define PMSG_RESUME ((struct pm_message){ .event = PM_EVENT_RESUME, })
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#define PMSG_THAW ((struct pm_message){ .event = PM_EVENT_THAW, })
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#define PMSG_RESTORE ((struct pm_message){ .event = PM_EVENT_RESTORE, })
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#define PMSG_RECOVER ((struct pm_message){ .event = PM_EVENT_RECOVER, })
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#define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, })
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/**
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* Device power management states
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*
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* These state labels are used internally by the PM core to indicate the current
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* status of a device with respect to the PM core operations.
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*
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* DPM_ON Device is regarded as operational. Set this way
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* initially and when ->complete() is about to be called.
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* Also set when ->prepare() fails.
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*
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* DPM_PREPARING Device is going to be prepared for a PM transition. Set
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* when ->prepare() is about to be called.
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*
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* DPM_RESUMING Device is going to be resumed. Set when ->resume(),
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* ->thaw(), or ->restore() is about to be called.
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*
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* DPM_SUSPENDING Device has been prepared for a power transition. Set
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* when ->prepare() has just succeeded.
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*
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* DPM_OFF Device is regarded as inactive. Set immediately after
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* ->suspend(), ->freeze(), or ->poweroff() has succeeded.
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* Also set when ->resume()_noirq, ->thaw_noirq(), or
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* ->restore_noirq() is about to be called.
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*
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* DPM_OFF_IRQ Device is in a "deep sleep". Set immediately after
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* ->suspend_noirq(), ->freeze_noirq(), or
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* ->poweroff_noirq() has just succeeded.
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*/
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enum dpm_state {
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DPM_INVALID,
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DPM_ON,
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DPM_PREPARING,
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DPM_RESUMING,
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DPM_SUSPENDING,
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DPM_OFF,
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DPM_OFF_IRQ,
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};
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struct dev_pm_info {
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pm_message_t power_state;
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unsigned can_wakeup:1;
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unsigned should_wakeup:1;
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enum dpm_state status; /* Owned by the PM core */
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#ifdef CONFIG_PM_SLEEP
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struct list_head entry;
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#endif
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};
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/*
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* The PM_EVENT_ messages are also used by drivers implementing the legacy
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* suspend framework, based on the ->suspend() and ->resume() callbacks common
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* for suspend and hibernation transitions, according to the rules below.
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*/
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/* Necessary, because several drivers use PM_EVENT_PRETHAW */
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#define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
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/*
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* One transition is triggered by resume(), after a suspend() call; the
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* message is implicit:
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*
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* ON Driver starts working again, responding to hardware events
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* and software requests. The hardware may have gone through
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* a power-off reset, or it may have maintained state from the
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* previous suspend() which the driver will rely on while
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* resuming. On most platforms, there are no restrictions on
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* availability of resources like clocks during resume().
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*
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* Other transitions are triggered by messages sent using suspend(). All
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* these transitions quiesce the driver, so that I/O queues are inactive.
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* That commonly entails turning off IRQs and DMA; there may be rules
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* about how to quiesce that are specific to the bus or the device's type.
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* (For example, network drivers mark the link state.) Other details may
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* differ according to the message:
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*
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* SUSPEND Quiesce, enter a low power device state appropriate for
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* the upcoming system state (such as PCI_D3hot), and enable
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* wakeup events as appropriate.
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*
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* HIBERNATE Enter a low power device state appropriate for the hibernation
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* state (eg. ACPI S4) and enable wakeup events as appropriate.
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*
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* FREEZE Quiesce operations so that a consistent image can be saved;
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* but do NOT otherwise enter a low power device state, and do
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* NOT emit system wakeup events.
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*
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* PRETHAW Quiesce as if for FREEZE; additionally, prepare for restoring
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* the system from a snapshot taken after an earlier FREEZE.
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* Some drivers will need to reset their hardware state instead
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* of preserving it, to ensure that it's never mistaken for the
|
|
* state which that earlier snapshot had set up.
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|
*
|
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* A minimally power-aware driver treats all messages as SUSPEND, fully
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|
* reinitializes its device during resume() -- whether or not it was reset
|
|
* during the suspend/resume cycle -- and can't issue wakeup events.
|
|
*
|
|
* More power-aware drivers may also use low power states at runtime as
|
|
* well as during system sleep states like PM_SUSPEND_STANDBY. They may
|
|
* be able to use wakeup events to exit from runtime low-power states,
|
|
* or from system low-power states such as standby or suspend-to-RAM.
|
|
*/
|
|
|
|
#ifdef CONFIG_PM_SLEEP
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|
extern void device_pm_lock(void);
|
|
extern void device_power_up(pm_message_t state);
|
|
extern void device_resume(pm_message_t state);
|
|
|
|
extern void device_pm_unlock(void);
|
|
extern int device_power_down(pm_message_t state);
|
|
extern int device_suspend(pm_message_t state);
|
|
extern int device_prepare_suspend(pm_message_t state);
|
|
|
|
extern void __suspend_report_result(const char *function, void *fn, int ret);
|
|
|
|
#define suspend_report_result(fn, ret) \
|
|
do { \
|
|
__suspend_report_result(__FUNCTION__, fn, ret); \
|
|
} while (0)
|
|
|
|
#else /* !CONFIG_PM_SLEEP */
|
|
|
|
static inline int device_suspend(pm_message_t state)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
#define suspend_report_result(fn, ret) do {} while (0)
|
|
|
|
#endif /* !CONFIG_PM_SLEEP */
|
|
|
|
/*
|
|
* Global Power Management flags
|
|
* Used to keep APM and ACPI from both being active
|
|
*/
|
|
extern unsigned int pm_flags;
|
|
|
|
#define PM_APM 1
|
|
#define PM_ACPI 2
|
|
|
|
#endif /* _LINUX_PM_H */
|