linux/drivers/base/sys.c
Rafael J. Wysocki 2ed8d2b3a8 PM: Rework handling of interrupts during suspend-resume
Use the functions introduced in by the previous patch,
suspend_device_irqs(), resume_device_irqs() and check_wakeup_irqs(),
to rework the handling of interrupts during suspend (hibernation) and
resume.  Namely, interrupts will only be disabled on the CPU right
before suspending sysdevs, while device drivers will be prevented
from receiving interrupts, with the help of the new helper function,
before their "late" suspend callbacks run (and analogously during
resume).

In addition, since the device interrups are now disabled before the
CPU has turned all interrupts off and the CPU will ACK the interrupts
setting the IRQ_PENDING bit for them, check in sysdev_suspend() if
any wake-up interrupts are pending and abort suspend if that's the
case.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Ingo Molnar <mingo@elte.hu>
2009-03-30 21:46:54 +02:00

533 lines
13 KiB
C

/*
* sys.c - pseudo-bus for system 'devices' (cpus, PICs, timers, etc)
*
* Copyright (c) 2002-3 Patrick Mochel
* 2002-3 Open Source Development Lab
*
* This file is released under the GPLv2
*
* This exports a 'system' bus type.
* By default, a 'sys' bus gets added to the root of the system. There will
* always be core system devices. Devices can use sysdev_register() to
* add themselves as children of the system bus.
*/
#include <linux/sysdev.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/interrupt.h>
#include "base.h"
#define to_sysdev(k) container_of(k, struct sys_device, kobj)
#define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr)
static ssize_t
sysdev_show(struct kobject *kobj, struct attribute *attr, char *buffer)
{
struct sys_device *sysdev = to_sysdev(kobj);
struct sysdev_attribute *sysdev_attr = to_sysdev_attr(attr);
if (sysdev_attr->show)
return sysdev_attr->show(sysdev, sysdev_attr, buffer);
return -EIO;
}
static ssize_t
sysdev_store(struct kobject *kobj, struct attribute *attr,
const char *buffer, size_t count)
{
struct sys_device *sysdev = to_sysdev(kobj);
struct sysdev_attribute *sysdev_attr = to_sysdev_attr(attr);
if (sysdev_attr->store)
return sysdev_attr->store(sysdev, sysdev_attr, buffer, count);
return -EIO;
}
static struct sysfs_ops sysfs_ops = {
.show = sysdev_show,
.store = sysdev_store,
};
static struct kobj_type ktype_sysdev = {
.sysfs_ops = &sysfs_ops,
};
int sysdev_create_file(struct sys_device *s, struct sysdev_attribute *a)
{
return sysfs_create_file(&s->kobj, &a->attr);
}
void sysdev_remove_file(struct sys_device *s, struct sysdev_attribute *a)
{
sysfs_remove_file(&s->kobj, &a->attr);
}
EXPORT_SYMBOL_GPL(sysdev_create_file);
EXPORT_SYMBOL_GPL(sysdev_remove_file);
#define to_sysdev_class(k) container_of(k, struct sysdev_class, kset.kobj)
#define to_sysdev_class_attr(a) container_of(a, \
struct sysdev_class_attribute, attr)
static ssize_t sysdev_class_show(struct kobject *kobj, struct attribute *attr,
char *buffer)
{
struct sysdev_class *class = to_sysdev_class(kobj);
struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);
if (class_attr->show)
return class_attr->show(class, buffer);
return -EIO;
}
static ssize_t sysdev_class_store(struct kobject *kobj, struct attribute *attr,
const char *buffer, size_t count)
{
struct sysdev_class *class = to_sysdev_class(kobj);
struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);
if (class_attr->store)
return class_attr->store(class, buffer, count);
return -EIO;
}
static struct sysfs_ops sysfs_class_ops = {
.show = sysdev_class_show,
.store = sysdev_class_store,
};
static struct kobj_type ktype_sysdev_class = {
.sysfs_ops = &sysfs_class_ops,
};
int sysdev_class_create_file(struct sysdev_class *c,
struct sysdev_class_attribute *a)
{
return sysfs_create_file(&c->kset.kobj, &a->attr);
}
EXPORT_SYMBOL_GPL(sysdev_class_create_file);
void sysdev_class_remove_file(struct sysdev_class *c,
struct sysdev_class_attribute *a)
{
sysfs_remove_file(&c->kset.kobj, &a->attr);
}
EXPORT_SYMBOL_GPL(sysdev_class_remove_file);
static struct kset *system_kset;
int sysdev_class_register(struct sysdev_class *cls)
{
pr_debug("Registering sysdev class '%s'\n", cls->name);
INIT_LIST_HEAD(&cls->drivers);
memset(&cls->kset.kobj, 0x00, sizeof(struct kobject));
cls->kset.kobj.parent = &system_kset->kobj;
cls->kset.kobj.ktype = &ktype_sysdev_class;
cls->kset.kobj.kset = system_kset;
kobject_set_name(&cls->kset.kobj, cls->name);
return kset_register(&cls->kset);
}
void sysdev_class_unregister(struct sysdev_class *cls)
{
pr_debug("Unregistering sysdev class '%s'\n",
kobject_name(&cls->kset.kobj));
kset_unregister(&cls->kset);
}
EXPORT_SYMBOL_GPL(sysdev_class_register);
EXPORT_SYMBOL_GPL(sysdev_class_unregister);
static DEFINE_MUTEX(sysdev_drivers_lock);
/**
* sysdev_driver_register - Register auxillary driver
* @cls: Device class driver belongs to.
* @drv: Driver.
*
* @drv is inserted into @cls->drivers to be
* called on each operation on devices of that class. The refcount
* of @cls is incremented.
*/
int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv)
{
int err = 0;
if (!cls) {
WARN(1, KERN_WARNING "sysdev: invalid class passed to "
"sysdev_driver_register!\n");
return -EINVAL;
}
/* Check whether this driver has already been added to a class. */
if (drv->entry.next && !list_empty(&drv->entry))
WARN(1, KERN_WARNING "sysdev: class %s: driver (%p) has already"
" been registered to a class, something is wrong, but "
"will forge on!\n", cls->name, drv);
mutex_lock(&sysdev_drivers_lock);
if (cls && kset_get(&cls->kset)) {
list_add_tail(&drv->entry, &cls->drivers);
/* If devices of this class already exist, tell the driver */
if (drv->add) {
struct sys_device *dev;
list_for_each_entry(dev, &cls->kset.list, kobj.entry)
drv->add(dev);
}
} else {
err = -EINVAL;
WARN(1, KERN_ERR "%s: invalid device class\n", __func__);
}
mutex_unlock(&sysdev_drivers_lock);
return err;
}
/**
* sysdev_driver_unregister - Remove an auxillary driver.
* @cls: Class driver belongs to.
* @drv: Driver.
*/
void sysdev_driver_unregister(struct sysdev_class *cls,
struct sysdev_driver *drv)
{
mutex_lock(&sysdev_drivers_lock);
list_del_init(&drv->entry);
if (cls) {
if (drv->remove) {
struct sys_device *dev;
list_for_each_entry(dev, &cls->kset.list, kobj.entry)
drv->remove(dev);
}
kset_put(&cls->kset);
}
mutex_unlock(&sysdev_drivers_lock);
}
EXPORT_SYMBOL_GPL(sysdev_driver_register);
EXPORT_SYMBOL_GPL(sysdev_driver_unregister);
/**
* sysdev_register - add a system device to the tree
* @sysdev: device in question
*
*/
int sysdev_register(struct sys_device *sysdev)
{
int error;
struct sysdev_class *cls = sysdev->cls;
if (!cls)
return -EINVAL;
pr_debug("Registering sys device of class '%s'\n",
kobject_name(&cls->kset.kobj));
/* initialize the kobject to 0, in case it had previously been used */
memset(&sysdev->kobj, 0x00, sizeof(struct kobject));
/* Make sure the kset is set */
sysdev->kobj.kset = &cls->kset;
/* Register the object */
error = kobject_init_and_add(&sysdev->kobj, &ktype_sysdev, NULL,
"%s%d", kobject_name(&cls->kset.kobj),
sysdev->id);
if (!error) {
struct sysdev_driver *drv;
pr_debug("Registering sys device '%s'\n",
kobject_name(&sysdev->kobj));
mutex_lock(&sysdev_drivers_lock);
/* Generic notification is implicit, because it's that
* code that should have called us.
*/
/* Notify class auxillary drivers */
list_for_each_entry(drv, &cls->drivers, entry) {
if (drv->add)
drv->add(sysdev);
}
mutex_unlock(&sysdev_drivers_lock);
}
kobject_uevent(&sysdev->kobj, KOBJ_ADD);
return error;
}
void sysdev_unregister(struct sys_device *sysdev)
{
struct sysdev_driver *drv;
mutex_lock(&sysdev_drivers_lock);
list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
if (drv->remove)
drv->remove(sysdev);
}
mutex_unlock(&sysdev_drivers_lock);
kobject_put(&sysdev->kobj);
}
/**
* sysdev_shutdown - Shut down all system devices.
*
* Loop over each class of system devices, and the devices in each
* of those classes. For each device, we call the shutdown method for
* each driver registered for the device - the auxillaries,
* and the class driver.
*
* Note: The list is iterated in reverse order, so that we shut down
* child devices before we shut down thier parents. The list ordering
* is guaranteed by virtue of the fact that child devices are registered
* after their parents.
*/
void sysdev_shutdown(void)
{
struct sysdev_class *cls;
pr_debug("Shutting Down System Devices\n");
mutex_lock(&sysdev_drivers_lock);
list_for_each_entry_reverse(cls, &system_kset->list, kset.kobj.entry) {
struct sys_device *sysdev;
pr_debug("Shutting down type '%s':\n",
kobject_name(&cls->kset.kobj));
list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
struct sysdev_driver *drv;
pr_debug(" %s\n", kobject_name(&sysdev->kobj));
/* Call auxillary drivers first */
list_for_each_entry(drv, &cls->drivers, entry) {
if (drv->shutdown)
drv->shutdown(sysdev);
}
/* Now call the generic one */
if (cls->shutdown)
cls->shutdown(sysdev);
}
}
mutex_unlock(&sysdev_drivers_lock);
}
static void __sysdev_resume(struct sys_device *dev)
{
struct sysdev_class *cls = dev->cls;
struct sysdev_driver *drv;
/* First, call the class-specific one */
if (cls->resume)
cls->resume(dev);
/* Call auxillary drivers next. */
list_for_each_entry(drv, &cls->drivers, entry) {
if (drv->resume)
drv->resume(dev);
}
}
/**
* sysdev_suspend - Suspend all system devices.
* @state: Power state to enter.
*
* We perform an almost identical operation as sysdev_shutdown()
* above, though calling ->suspend() instead. Interrupts are disabled
* when this called. Devices are responsible for both saving state and
* quiescing or powering down the device.
*
* This is only called by the device PM core, so we let them handle
* all synchronization.
*/
int sysdev_suspend(pm_message_t state)
{
struct sysdev_class *cls;
struct sys_device *sysdev, *err_dev;
struct sysdev_driver *drv, *err_drv;
int ret;
pr_debug("Checking wake-up interrupts\n");
/* Return error code if there are any wake-up interrupts pending */
ret = check_wakeup_irqs();
if (ret)
return ret;
pr_debug("Suspending System Devices\n");
list_for_each_entry_reverse(cls, &system_kset->list, kset.kobj.entry) {
pr_debug("Suspending type '%s':\n",
kobject_name(&cls->kset.kobj));
list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
pr_debug(" %s\n", kobject_name(&sysdev->kobj));
/* Call auxillary drivers first */
list_for_each_entry(drv, &cls->drivers, entry) {
if (drv->suspend) {
ret = drv->suspend(sysdev, state);
if (ret)
goto aux_driver;
}
}
/* Now call the generic one */
if (cls->suspend) {
ret = cls->suspend(sysdev, state);
if (ret)
goto cls_driver;
}
}
}
return 0;
/* resume current sysdev */
cls_driver:
drv = NULL;
printk(KERN_ERR "Class suspend failed for %s\n",
kobject_name(&sysdev->kobj));
aux_driver:
if (drv)
printk(KERN_ERR "Class driver suspend failed for %s\n",
kobject_name(&sysdev->kobj));
list_for_each_entry(err_drv, &cls->drivers, entry) {
if (err_drv == drv)
break;
if (err_drv->resume)
err_drv->resume(sysdev);
}
/* resume other sysdevs in current class */
list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
if (err_dev == sysdev)
break;
pr_debug(" %s\n", kobject_name(&err_dev->kobj));
__sysdev_resume(err_dev);
}
/* resume other classes */
list_for_each_entry_continue(cls, &system_kset->list, kset.kobj.entry) {
list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
pr_debug(" %s\n", kobject_name(&err_dev->kobj));
__sysdev_resume(err_dev);
}
}
return ret;
}
EXPORT_SYMBOL_GPL(sysdev_suspend);
/**
* sysdev_resume - Bring system devices back to life.
*
* Similar to sysdev_suspend(), but we iterate the list forwards
* to guarantee that parent devices are resumed before their children.
*
* Note: Interrupts are disabled when called.
*/
int sysdev_resume(void)
{
struct sysdev_class *cls;
pr_debug("Resuming System Devices\n");
list_for_each_entry(cls, &system_kset->list, kset.kobj.entry) {
struct sys_device *sysdev;
pr_debug("Resuming type '%s':\n",
kobject_name(&cls->kset.kobj));
list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
pr_debug(" %s\n", kobject_name(&sysdev->kobj));
__sysdev_resume(sysdev);
}
}
return 0;
}
EXPORT_SYMBOL_GPL(sysdev_resume);
int __init system_bus_init(void)
{
system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
if (!system_kset)
return -ENOMEM;
return 0;
}
EXPORT_SYMBOL_GPL(sysdev_register);
EXPORT_SYMBOL_GPL(sysdev_unregister);
#define to_ext_attr(x) container_of(x, struct sysdev_ext_attribute, attr)
ssize_t sysdev_store_ulong(struct sys_device *sysdev,
struct sysdev_attribute *attr,
const char *buf, size_t size)
{
struct sysdev_ext_attribute *ea = to_ext_attr(attr);
char *end;
unsigned long new = simple_strtoul(buf, &end, 0);
if (end == buf)
return -EINVAL;
*(unsigned long *)(ea->var) = new;
/* Always return full write size even if we didn't consume all */
return size;
}
EXPORT_SYMBOL_GPL(sysdev_store_ulong);
ssize_t sysdev_show_ulong(struct sys_device *sysdev,
struct sysdev_attribute *attr,
char *buf)
{
struct sysdev_ext_attribute *ea = to_ext_attr(attr);
return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
}
EXPORT_SYMBOL_GPL(sysdev_show_ulong);
ssize_t sysdev_store_int(struct sys_device *sysdev,
struct sysdev_attribute *attr,
const char *buf, size_t size)
{
struct sysdev_ext_attribute *ea = to_ext_attr(attr);
char *end;
long new = simple_strtol(buf, &end, 0);
if (end == buf || new > INT_MAX || new < INT_MIN)
return -EINVAL;
*(int *)(ea->var) = new;
/* Always return full write size even if we didn't consume all */
return size;
}
EXPORT_SYMBOL_GPL(sysdev_store_int);
ssize_t sysdev_show_int(struct sys_device *sysdev,
struct sysdev_attribute *attr,
char *buf)
{
struct sysdev_ext_attribute *ea = to_ext_attr(attr);
return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
}
EXPORT_SYMBOL_GPL(sysdev_show_int);