linux-hardened/include/linux/device.h
Rafael J. Wysocki 5af84b8270 PM: Asynchronous suspend and resume of devices
Theoretically, the total time of system sleep transitions (suspend
to RAM, hibernation) can be reduced by running suspend and resume
callbacks of device drivers in parallel with each other.  However,
there are dependencies between devices such that we're not allowed
to suspend the parent of a device before suspending the device
itself.  Analogously, we're not allowed to resume a device before
resuming its parent.

The most straightforward way to take these dependencies into accout
is to start the async threads used for suspending and resuming
devices at the core level, so that async_schedule() is called for
each suspend and resume callback supposed to be executed
asynchronously.

For this purpose, introduce a new device flag, power.async_suspend,
used to mark the devices whose suspend and resume callbacks are to be
executed asynchronously (ie. in parallel with the main suspend/resume
thread and possibly in parallel with each other) and helper function
device_enable_async_suspend() allowing one to set power.async_suspend
for given device (power.async_suspend is unset by default for all
devices).  For each device with the power.async_suspend flag set the
PM core will use async_schedule() to execute its suspend and resume
callbacks.

The async threads started for different devices as a result of
calling async_schedule() are synchronized with each other and with
the main suspend/resume thread with the help of completions, in the
following way:
(1) There is a completion, power.completion, for each device object.
(2) Each device's completion is reset before calling async_schedule()
    for the device or, in the case of devices with the
    power.async_suspend flags unset, before executing the device's
    suspend and resume callbacks.
(3) During suspend, right before running the bus type, device type
    and device class suspend callbacks for the device, the PM core
    waits for the completions of all the device's children to be
    completed.
(4) During resume, right before running the bus type, device type and
    device class resume callbacks for the device, the PM core waits
    for the completion of the device's parent to be completed.
(5) The PM core completes power.completion for each device right
    after the bus type, device type and device class suspend (or
    resume) callbacks executed for the device have returned.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-02-26 20:39:09 +01:00

634 lines
20 KiB
C

/*
* device.h - generic, centralized driver model
*
* Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
* Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
* Copyright (c) 2008-2009 Novell Inc.
*
* This file is released under the GPLv2
*
* See Documentation/driver-model/ for more information.
*/
#ifndef _DEVICE_H_
#define _DEVICE_H_
#include <linux/ioport.h>
#include <linux/kobject.h>
#include <linux/klist.h>
#include <linux/list.h>
#include <linux/lockdep.h>
#include <linux/compiler.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/pm.h>
#include <linux/semaphore.h>
#include <asm/atomic.h>
#include <asm/device.h>
struct device;
struct device_private;
struct device_driver;
struct driver_private;
struct class;
struct class_private;
struct bus_type;
struct bus_type_private;
struct bus_attribute {
struct attribute attr;
ssize_t (*show)(struct bus_type *bus, char *buf);
ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);
};
#define BUS_ATTR(_name, _mode, _show, _store) \
struct bus_attribute bus_attr_##_name = __ATTR(_name, _mode, _show, _store)
extern int __must_check bus_create_file(struct bus_type *,
struct bus_attribute *);
extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
struct bus_type {
const char *name;
struct bus_attribute *bus_attrs;
struct device_attribute *dev_attrs;
struct driver_attribute *drv_attrs;
int (*match)(struct device *dev, struct device_driver *drv);
int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
int (*probe)(struct device *dev);
int (*remove)(struct device *dev);
void (*shutdown)(struct device *dev);
int (*suspend)(struct device *dev, pm_message_t state);
int (*resume)(struct device *dev);
const struct dev_pm_ops *pm;
struct bus_type_private *p;
};
extern int __must_check bus_register(struct bus_type *bus);
extern void bus_unregister(struct bus_type *bus);
extern int __must_check bus_rescan_devices(struct bus_type *bus);
/* iterator helpers for buses */
int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
int (*fn)(struct device *dev, void *data));
struct device *bus_find_device(struct bus_type *bus, struct device *start,
void *data,
int (*match)(struct device *dev, void *data));
struct device *bus_find_device_by_name(struct bus_type *bus,
struct device *start,
const char *name);
int __must_check bus_for_each_drv(struct bus_type *bus,
struct device_driver *start, void *data,
int (*fn)(struct device_driver *, void *));
void bus_sort_breadthfirst(struct bus_type *bus,
int (*compare)(const struct device *a,
const struct device *b));
/*
* Bus notifiers: Get notified of addition/removal of devices
* and binding/unbinding of drivers to devices.
* In the long run, it should be a replacement for the platform
* notify hooks.
*/
struct notifier_block;
extern int bus_register_notifier(struct bus_type *bus,
struct notifier_block *nb);
extern int bus_unregister_notifier(struct bus_type *bus,
struct notifier_block *nb);
/* All 4 notifers below get called with the target struct device *
* as an argument. Note that those functions are likely to be called
* with the device semaphore held in the core, so be careful.
*/
#define BUS_NOTIFY_ADD_DEVICE 0x00000001 /* device added */
#define BUS_NOTIFY_DEL_DEVICE 0x00000002 /* device removed */
#define BUS_NOTIFY_BOUND_DRIVER 0x00000003 /* driver bound to device */
#define BUS_NOTIFY_UNBIND_DRIVER 0x00000004 /* driver about to be
unbound */
#define BUS_NOTIFY_UNBOUND_DRIVER 0x00000005 /* driver is unbound
from the device */
extern struct kset *bus_get_kset(struct bus_type *bus);
extern struct klist *bus_get_device_klist(struct bus_type *bus);
struct device_driver {
const char *name;
struct bus_type *bus;
struct module *owner;
const char *mod_name; /* used for built-in modules */
bool suppress_bind_attrs; /* disables bind/unbind via sysfs */
int (*probe) (struct device *dev);
int (*remove) (struct device *dev);
void (*shutdown) (struct device *dev);
int (*suspend) (struct device *dev, pm_message_t state);
int (*resume) (struct device *dev);
const struct attribute_group **groups;
const struct dev_pm_ops *pm;
struct driver_private *p;
};
extern int __must_check driver_register(struct device_driver *drv);
extern void driver_unregister(struct device_driver *drv);
extern struct device_driver *get_driver(struct device_driver *drv);
extern void put_driver(struct device_driver *drv);
extern struct device_driver *driver_find(const char *name,
struct bus_type *bus);
extern int driver_probe_done(void);
extern void wait_for_device_probe(void);
/* sysfs interface for exporting driver attributes */
struct driver_attribute {
struct attribute attr;
ssize_t (*show)(struct device_driver *driver, char *buf);
ssize_t (*store)(struct device_driver *driver, const char *buf,
size_t count);
};
#define DRIVER_ATTR(_name, _mode, _show, _store) \
struct driver_attribute driver_attr_##_name = \
__ATTR(_name, _mode, _show, _store)
extern int __must_check driver_create_file(struct device_driver *driver,
const struct driver_attribute *attr);
extern void driver_remove_file(struct device_driver *driver,
const struct driver_attribute *attr);
extern int __must_check driver_add_kobj(struct device_driver *drv,
struct kobject *kobj,
const char *fmt, ...);
extern int __must_check driver_for_each_device(struct device_driver *drv,
struct device *start,
void *data,
int (*fn)(struct device *dev,
void *));
struct device *driver_find_device(struct device_driver *drv,
struct device *start, void *data,
int (*match)(struct device *dev, void *data));
/*
* device classes
*/
struct class {
const char *name;
struct module *owner;
struct class_attribute *class_attrs;
struct device_attribute *dev_attrs;
struct kobject *dev_kobj;
int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
char *(*devnode)(struct device *dev, mode_t *mode);
void (*class_release)(struct class *class);
void (*dev_release)(struct device *dev);
int (*suspend)(struct device *dev, pm_message_t state);
int (*resume)(struct device *dev);
const struct dev_pm_ops *pm;
struct class_private *p;
};
struct class_dev_iter {
struct klist_iter ki;
const struct device_type *type;
};
extern struct kobject *sysfs_dev_block_kobj;
extern struct kobject *sysfs_dev_char_kobj;
extern int __must_check __class_register(struct class *class,
struct lock_class_key *key);
extern void class_unregister(struct class *class);
/* This is a #define to keep the compiler from merging different
* instances of the __key variable */
#define class_register(class) \
({ \
static struct lock_class_key __key; \
__class_register(class, &__key); \
})
struct class_compat;
struct class_compat *class_compat_register(const char *name);
void class_compat_unregister(struct class_compat *cls);
int class_compat_create_link(struct class_compat *cls, struct device *dev,
struct device *device_link);
void class_compat_remove_link(struct class_compat *cls, struct device *dev,
struct device *device_link);
extern void class_dev_iter_init(struct class_dev_iter *iter,
struct class *class,
struct device *start,
const struct device_type *type);
extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
extern void class_dev_iter_exit(struct class_dev_iter *iter);
extern int class_for_each_device(struct class *class, struct device *start,
void *data,
int (*fn)(struct device *dev, void *data));
extern struct device *class_find_device(struct class *class,
struct device *start, void *data,
int (*match)(struct device *, void *));
struct class_attribute {
struct attribute attr;
ssize_t (*show)(struct class *class, char *buf);
ssize_t (*store)(struct class *class, const char *buf, size_t count);
};
#define CLASS_ATTR(_name, _mode, _show, _store) \
struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store)
extern int __must_check class_create_file(struct class *class,
const struct class_attribute *attr);
extern void class_remove_file(struct class *class,
const struct class_attribute *attr);
struct class_interface {
struct list_head node;
struct class *class;
int (*add_dev) (struct device *, struct class_interface *);
void (*remove_dev) (struct device *, struct class_interface *);
};
extern int __must_check class_interface_register(struct class_interface *);
extern void class_interface_unregister(struct class_interface *);
extern struct class * __must_check __class_create(struct module *owner,
const char *name,
struct lock_class_key *key);
extern void class_destroy(struct class *cls);
/* This is a #define to keep the compiler from merging different
* instances of the __key variable */
#define class_create(owner, name) \
({ \
static struct lock_class_key __key; \
__class_create(owner, name, &__key); \
})
/*
* The type of device, "struct device" is embedded in. A class
* or bus can contain devices of different types
* like "partitions" and "disks", "mouse" and "event".
* This identifies the device type and carries type-specific
* information, equivalent to the kobj_type of a kobject.
* If "name" is specified, the uevent will contain it in
* the DEVTYPE variable.
*/
struct device_type {
const char *name;
const struct attribute_group **groups;
int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
char *(*devnode)(struct device *dev, mode_t *mode);
void (*release)(struct device *dev);
const struct dev_pm_ops *pm;
};
/* interface for exporting device attributes */
struct device_attribute {
struct attribute attr;
ssize_t (*show)(struct device *dev, struct device_attribute *attr,
char *buf);
ssize_t (*store)(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count);
};
#define DEVICE_ATTR(_name, _mode, _show, _store) \
struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
extern int __must_check device_create_file(struct device *device,
const struct device_attribute *entry);
extern void device_remove_file(struct device *dev,
const struct device_attribute *attr);
extern int __must_check device_create_bin_file(struct device *dev,
const struct bin_attribute *attr);
extern void device_remove_bin_file(struct device *dev,
const struct bin_attribute *attr);
extern int device_schedule_callback_owner(struct device *dev,
void (*func)(struct device *dev), struct module *owner);
/* This is a macro to avoid include problems with THIS_MODULE */
#define device_schedule_callback(dev, func) \
device_schedule_callback_owner(dev, func, THIS_MODULE)
/* device resource management */
typedef void (*dr_release_t)(struct device *dev, void *res);
typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
#ifdef CONFIG_DEBUG_DEVRES
extern void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
const char *name);
#define devres_alloc(release, size, gfp) \
__devres_alloc(release, size, gfp, #release)
#else
extern void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp);
#endif
extern void devres_free(void *res);
extern void devres_add(struct device *dev, void *res);
extern void *devres_find(struct device *dev, dr_release_t release,
dr_match_t match, void *match_data);
extern void *devres_get(struct device *dev, void *new_res,
dr_match_t match, void *match_data);
extern void *devres_remove(struct device *dev, dr_release_t release,
dr_match_t match, void *match_data);
extern int devres_destroy(struct device *dev, dr_release_t release,
dr_match_t match, void *match_data);
/* devres group */
extern void * __must_check devres_open_group(struct device *dev, void *id,
gfp_t gfp);
extern void devres_close_group(struct device *dev, void *id);
extern void devres_remove_group(struct device *dev, void *id);
extern int devres_release_group(struct device *dev, void *id);
/* managed kzalloc/kfree for device drivers, no kmalloc, always use kzalloc */
extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp);
extern void devm_kfree(struct device *dev, void *p);
struct device_dma_parameters {
/*
* a low level driver may set these to teach IOMMU code about
* sg limitations.
*/
unsigned int max_segment_size;
unsigned long segment_boundary_mask;
};
struct device {
struct device *parent;
struct device_private *p;
struct kobject kobj;
const char *init_name; /* initial name of the device */
struct device_type *type;
struct semaphore sem; /* semaphore to synchronize calls to
* its driver.
*/
struct bus_type *bus; /* type of bus device is on */
struct device_driver *driver; /* which driver has allocated this
device */
void *platform_data; /* Platform specific data, device
core doesn't touch it */
struct dev_pm_info power;
#ifdef CONFIG_NUMA
int numa_node; /* NUMA node this device is close to */
#endif
u64 *dma_mask; /* dma mask (if dma'able device) */
u64 coherent_dma_mask;/* Like dma_mask, but for
alloc_coherent mappings as
not all hardware supports
64 bit addresses for consistent
allocations such descriptors. */
struct device_dma_parameters *dma_parms;
struct list_head dma_pools; /* dma pools (if dma'ble) */
struct dma_coherent_mem *dma_mem; /* internal for coherent mem
override */
/* arch specific additions */
struct dev_archdata archdata;
dev_t devt; /* dev_t, creates the sysfs "dev" */
spinlock_t devres_lock;
struct list_head devres_head;
struct klist_node knode_class;
struct class *class;
const struct attribute_group **groups; /* optional groups */
void (*release)(struct device *dev);
};
/* Get the wakeup routines, which depend on struct device */
#include <linux/pm_wakeup.h>
static inline const char *dev_name(const struct device *dev)
{
return kobject_name(&dev->kobj);
}
extern int dev_set_name(struct device *dev, const char *name, ...)
__attribute__((format(printf, 2, 3)));
#ifdef CONFIG_NUMA
static inline int dev_to_node(struct device *dev)
{
return dev->numa_node;
}
static inline void set_dev_node(struct device *dev, int node)
{
dev->numa_node = node;
}
#else
static inline int dev_to_node(struct device *dev)
{
return -1;
}
static inline void set_dev_node(struct device *dev, int node)
{
}
#endif
static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
{
return dev->kobj.uevent_suppress;
}
static inline void dev_set_uevent_suppress(struct device *dev, int val)
{
dev->kobj.uevent_suppress = val;
}
static inline int device_is_registered(struct device *dev)
{
return dev->kobj.state_in_sysfs;
}
static inline void device_enable_async_suspend(struct device *dev)
{
if (dev->power.status == DPM_ON)
dev->power.async_suspend = true;
}
void driver_init(void);
/*
* High level routines for use by the bus drivers
*/
extern int __must_check device_register(struct device *dev);
extern void device_unregister(struct device *dev);
extern void device_initialize(struct device *dev);
extern int __must_check device_add(struct device *dev);
extern void device_del(struct device *dev);
extern int device_for_each_child(struct device *dev, void *data,
int (*fn)(struct device *dev, void *data));
extern struct device *device_find_child(struct device *dev, void *data,
int (*match)(struct device *dev, void *data));
extern int device_rename(struct device *dev, char *new_name);
extern int device_move(struct device *dev, struct device *new_parent,
enum dpm_order dpm_order);
extern const char *device_get_devnode(struct device *dev,
mode_t *mode, const char **tmp);
extern void *dev_get_drvdata(const struct device *dev);
extern void dev_set_drvdata(struct device *dev, void *data);
/*
* Root device objects for grouping under /sys/devices
*/
extern struct device *__root_device_register(const char *name,
struct module *owner);
static inline struct device *root_device_register(const char *name)
{
return __root_device_register(name, THIS_MODULE);
}
extern void root_device_unregister(struct device *root);
static inline void *dev_get_platdata(const struct device *dev)
{
return dev->platform_data;
}
/*
* Manual binding of a device to driver. See drivers/base/bus.c
* for information on use.
*/
extern int __must_check device_bind_driver(struct device *dev);
extern void device_release_driver(struct device *dev);
extern int __must_check device_attach(struct device *dev);
extern int __must_check driver_attach(struct device_driver *drv);
extern int __must_check device_reprobe(struct device *dev);
/*
* Easy functions for dynamically creating devices on the fly
*/
extern struct device *device_create_vargs(struct class *cls,
struct device *parent,
dev_t devt,
void *drvdata,
const char *fmt,
va_list vargs);
extern struct device *device_create(struct class *cls, struct device *parent,
dev_t devt, void *drvdata,
const char *fmt, ...)
__attribute__((format(printf, 5, 6)));
extern void device_destroy(struct class *cls, dev_t devt);
/*
* Platform "fixup" functions - allow the platform to have their say
* about devices and actions that the general device layer doesn't
* know about.
*/
/* Notify platform of device discovery */
extern int (*platform_notify)(struct device *dev);
extern int (*platform_notify_remove)(struct device *dev);
/**
* get_device - atomically increment the reference count for the device.
*
*/
extern struct device *get_device(struct device *dev);
extern void put_device(struct device *dev);
extern void wait_for_device_probe(void);
#ifdef CONFIG_DEVTMPFS
extern int devtmpfs_create_node(struct device *dev);
extern int devtmpfs_delete_node(struct device *dev);
extern int devtmpfs_mount(const char *mntdir);
#else
static inline int devtmpfs_create_node(struct device *dev) { return 0; }
static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
static inline int devtmpfs_mount(const char *mountpoint) { return 0; }
#endif
/* drivers/base/power/shutdown.c */
extern void device_shutdown(void);
/* drivers/base/sys.c */
extern void sysdev_shutdown(void);
/* debugging and troubleshooting/diagnostic helpers. */
extern const char *dev_driver_string(const struct device *dev);
#define dev_printk(level, dev, format, arg...) \
printk(level "%s %s: " format , dev_driver_string(dev) , \
dev_name(dev) , ## arg)
#define dev_emerg(dev, format, arg...) \
dev_printk(KERN_EMERG , dev , format , ## arg)
#define dev_alert(dev, format, arg...) \
dev_printk(KERN_ALERT , dev , format , ## arg)
#define dev_crit(dev, format, arg...) \
dev_printk(KERN_CRIT , dev , format , ## arg)
#define dev_err(dev, format, arg...) \
dev_printk(KERN_ERR , dev , format , ## arg)
#define dev_warn(dev, format, arg...) \
dev_printk(KERN_WARNING , dev , format , ## arg)
#define dev_notice(dev, format, arg...) \
dev_printk(KERN_NOTICE , dev , format , ## arg)
#define dev_info(dev, format, arg...) \
dev_printk(KERN_INFO , dev , format , ## arg)
#if defined(DEBUG)
#define dev_dbg(dev, format, arg...) \
dev_printk(KERN_DEBUG , dev , format , ## arg)
#elif defined(CONFIG_DYNAMIC_DEBUG)
#define dev_dbg(dev, format, ...) do { \
dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \
} while (0)
#else
#define dev_dbg(dev, format, arg...) \
({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; })
#endif
#ifdef VERBOSE_DEBUG
#define dev_vdbg dev_dbg
#else
#define dev_vdbg(dev, format, arg...) \
({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; })
#endif
/*
* dev_WARN() acts like dev_printk(), but with the key difference
* of using a WARN/WARN_ON to get the message out, including the
* file/line information and a backtrace.
*/
#define dev_WARN(dev, format, arg...) \
WARN(1, "Device: %s\n" format, dev_driver_string(dev), ## arg);
/* Create alias, so I can be autoloaded. */
#define MODULE_ALIAS_CHARDEV(major,minor) \
MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))
#define MODULE_ALIAS_CHARDEV_MAJOR(major) \
MODULE_ALIAS("char-major-" __stringify(major) "-*")
#endif /* _DEVICE_H_ */