[RFC 1/2] PM: merge drivers/base/power/{main, suspend, resume}.c

Alan Stern
2007-07-31T20:48:49Z

On Tue, 31 Jul 2007, Rafael J. Wysocki wrote:

> > Binding and unbinding aren't an issue once the PM core owns all the
> > device semaphores.
>
> Yes, but currently they aren't held accross the entire suspend.

Here's my answer to that. The first patch in this series simply merges
several files into one, allowing stuff to be eliminated from the header
file and various symbols to be made static. The second patch makes
some genuine changes... coming up.

Alan Stern

Index: usb-2.6/drivers/base/power/Makefile
===================================================================
--- usb-2.6.orig/drivers/base/power/Makefile
+++ usb-2.6/drivers/base/power/Makefile
@@ -1,5 +1,5 @@
obj-y := shutdown.o
-obj-$(CONFIG_PM) += main.o suspend.o resume.o sysfs.o
+obj-$(CONFIG_PM) += main.o sysfs.o
obj-$(CONFIG_PM_TRACE) += trace.o

ifeq ($(CONFIG_DEBUG_DRIVER),y)
Index: usb-2.6/drivers/base/power/power.h
===================================================================
--- usb-2.6.orig/drivers/base/power/power.h
+++ usb-2.6/drivers/base/power/power.h
@@ -11,32 +11,11 @@ extern void device_shutdown(void);
* main.c
*/

-/*
- * Used to synchronize global power management operations.
- */
-extern struct mutex dpm_mtx;
-
-/*
- * Used to serialize changes to the dpm_* lists.
- */
-extern struct mutex dpm_list_mtx;
-
-/*
- * The PM lists.
- */
-extern struct list_head dpm_active;
-extern struct list_head dpm_off;
-extern struct list_head dpm_off_irq;
-
-
-static inline struct dev_pm_info * to_pm_info(struct list_head * entry)
-{
- return container_of(entry, struct dev_pm_info, entry);
-}
+extern struct list_head dpm_active; /* The active device list */

static inline struct device * to_device(struct list_head * entry)
{
- return container_of(to_pm_info(entry), struct device, power);
+ return container_of(entry, struct device, power.entry);
}

extern int device_pm_add(struct device *);
@@ -49,19 +28,6 @@ extern void device_pm_remove(struct devi
extern int dpm_sysfs_add(struct device *);
extern void dpm_sysfs_remove(struct device *);

-/*
- * resume.c
- */
-
-extern void dpm_resume(void);
-extern void dpm_power_up(void);
-extern int resume_device(struct device *);
-
-/*
- * suspend.c
- */
-extern int suspend_device(struct device *, pm_message_t);
-
#else /* CONFIG_PM */

Index: usb-2.6/drivers/base/power/main.c
===================================================================
--- usb-2.6.orig/drivers/base/power/main.c
+++ usb-2.6/drivers/base/power/main.c
@@ -20,19 +20,24 @@
*/

#include <linux/device.h>
+#include <linux/kallsyms.h>
#include <linux/mutex.h>
+#include <linux/pm.h>
+#include <linux/resume-trace.h>

+#include "../base.h"
#include "power.h"

LIST_HEAD(dpm_active);
-LIST_HEAD(dpm_off);
-LIST_HEAD(dpm_off_irq);
+static LIST_HEAD(dpm_off);
+static LIST_HEAD(dpm_off_irq);

-DEFINE_MUTEX(dpm_mtx);
-DEFINE_MUTEX(dpm_list_mtx);
+static DEFINE_MUTEX(dpm_mtx);
+static DEFINE_MUTEX(dpm_list_mtx);

int (*platform_enable_wakeup)(struct device *dev, int is_on);

+
int device_pm_add(struct device *dev)
{
int error;
@@ -61,3 +66,334 @@ void device_pm_remove(struct device *dev
}

+/*------------------------- Resume routines -------------------------*/
+
+/**
+ * resume_device - Restore state for one device.
+ * @dev: Device.
+ *
+ */
+
+int resume_device(struct device * dev)
+{
+ int error = 0;
+
+ TRACE_DEVICE(dev);
+ TRACE_RESUME(0);
+
+ down(&dev->sem);
+
+ if (dev->bus && dev->bus->resume) {
+ dev_dbg(dev,"resuming\n");
+ error = dev->bus->resume(dev);
+ }
+
+ if (!error && dev->type && dev->type->resume) {
+ dev_dbg(dev,"resuming\n");
+ error = dev->type->resume(dev);
+ }
+
+ if (!error && dev->class && dev->class->resume) {
+ dev_dbg(dev,"class resume\n");
+ error = dev->class->resume(dev);
+ }
+
+ up(&dev->sem);
+
+ TRACE_RESUME(error);
+ return error;
+}
+
+
+static int resume_device_early(struct device * dev)
+{
+ int error = 0;
+
+ TRACE_DEVICE(dev);
+ TRACE_RESUME(0);
+ if (dev->bus && dev->bus->resume_early) {
+ dev_dbg(dev,"EARLY resume\n");
+ error = dev->bus->resume_early(dev);
+ }
+ TRACE_RESUME(error);
+ return error;
+}
+
+/*
+ * Resume the devices that have either not gone through
+ * the late suspend, or that did go through it but also
+ * went through the early resume
+ */
+static void dpm_resume(void)
+{
+ mutex_lock(&dpm_list_mtx);
+ while(!list_empty(&dpm_off)) {
+ struct list_head * entry = dpm_off.next;
+ struct device * dev = to_device(entry);
+
+ get_device(dev);
+ list_move_tail(entry, &dpm_active);
+
+ mutex_unlock(&dpm_list_mtx);
+ resume_device(dev);
+ mutex_lock(&dpm_list_mtx);
+ put_device(dev);
+ }
+ mutex_unlock(&dpm_list_mtx);
+}
+
+
+/**
+ * device_resume - Restore state of each device in system.
+ *
+ * Walk the dpm_off list, remove each entry, resume the device,
+ * then add it to the dpm_active list.
+ */
+
+void device_resume(void)
+{
+ might_sleep();
+ mutex_lock(&dpm_mtx);
+ dpm_resume();
+ mutex_unlock(&dpm_mtx);
+}
+
+EXPORT_SYMBOL_GPL(device_resume);
+
+
+/**
+ * dpm_power_up - Power on some devices.
+ *
+ * Walk the dpm_off_irq list and power each device up. This
+ * is used for devices that required they be powered down with
+ * interrupts disabled. As devices are powered on, they are moved
+ * to the dpm_active list.
+ *
+ * Interrupts must be disabled when calling this.
+ */
+
+static void dpm_power_up(void)
+{
+ while(!list_empty(&dpm_off_irq)) {
+ struct list_head * entry = dpm_off_irq.next;
+ struct device * dev = to_device(entry);
+
+ list_move_tail(entry, &dpm_off);
+ resume_device_early(dev);
+ }
+}
+
+
+/**
+ * device_power_up - Turn on all devices that need special attention.
+ *
+ * Power on system devices then devices that required we shut them down
+ * with interrupts disabled.
+ * Called with interrupts disabled.
+ */
+
+void device_power_up(void)
+{
+ sysdev_resume();
+ dpm_power_up();
+}
+
+EXPORT_SYMBOL_GPL(device_power_up);
+
+
+/*------------------------- Suspend routines -------------------------*/
+
+/*
+ * The entries in the dpm_active list are in a depth first order, simply
+ * because children are guaranteed to be discovered after parents, and
+ * are inserted at the back of the list on discovery.
+ *
+ * All list on the suspend path are done in reverse order, so we operate
+ * on the leaves of the device tree (or forests, depending on how you want
+ * to look at it ;) first. As nodes are removed from the back of the list,
+ * they are inserted into the front of their destintation lists.
+ *
+ * Things are the reverse on the resume path - iterations are done in
+ * forward order, and nodes are inserted at the back of their destination
+ * lists. This way, the ancestors will be accessed before their descendents.
+ */
+
+static inline char *suspend_verb(u32 event)
+{
+ switch (event) {
+ case PM_EVENT_SUSPEND: return "suspend";
+ case PM_EVENT_FREEZE: return "freeze";
+ case PM_EVENT_PRETHAW: return "prethaw";
+ default: return "(unknown suspend event)";
+ }
+}
+
+
+static void
+suspend_device_dbg(struct device *dev, pm_message_t state, char *info)
+{
+ dev_dbg(dev, "%s%s%s\n", info, suspend_verb(state.event),
+ ((state.event == PM_EVENT_SUSPEND) && device_may_wakeup(dev)) ?
+ ", may wakeup" : "");
+}
+
+/**
+ * suspend_device - Save state of one device.
+ * @dev: Device.
+ * @state: Power state device is entering.
+ */
+
+int suspend_device(struct device * dev, pm_message_t state)
+{
+ int error = 0;
+
+ down(&dev->sem);
+ if (dev->power.power_state.event) {
+ dev_dbg(dev, "PM: suspend %d-->%d\n",
+ dev->power.power_state.event, state.event);
+ }
+
+ if (dev->class && dev->class->suspend) {
+ suspend_device_dbg(dev, state, "class ");
+ error = dev->class->suspend(dev, state);
+ suspend_report_result(dev->class->suspend, error);
+ }
+
+ if (!error && dev->type && dev->type->suspend) {
+ suspend_device_dbg(dev, state, "type ");
+ error = dev->type->suspend(dev, state);
+ suspend_report_result(dev->type->suspend, error);
+ }
+
+ if (!error && dev->bus && dev->bus->suspend) {
+ suspend_device_dbg(dev, state, "");
+ error = dev->bus->suspend(dev, state);
+ suspend_report_result(dev->bus->suspend, error);
+ }
+ up(&dev->sem);
+ return error;
+}
+
+
+/*
+ * This is called with interrupts off, only a single CPU
+ * running. We can't acquire a mutex or semaphore (and we don't
+ * need the protection)
+ */
+static int suspend_device_late(struct device *dev, pm_message_t state)
+{
+ int error = 0;
+
+ if (dev->bus && dev->bus->suspend_late) {
+ suspend_device_dbg(dev, state, "LATE ");
+ error = dev->bus->suspend_late(dev, state);
+ suspend_report_result(dev->bus->suspend_late, error);
+ }
+ return error;
+}
+
+/**
+ * device_suspend - Save state and stop all devices in system.
+ * @state: Power state to put each device in.
+ *
+ * Walk the dpm_active list, call ->suspend() for each device, and move
+ * it to the dpm_off list.
+ *
+ * (For historical reasons, if it returns -EAGAIN, that used to mean
+ * that the device would be called again with interrupts disabled.
+ * These days, we use the "suspend_late()" callback for that, so we
+ * print a warning and consider it an error).
+ *
+ * If we get a different error, try and back out.
+ *
+ * If we hit a failure with any of the devices, call device_resume()
+ * above to bring the suspended devices back to life.
+ *
+ */
+
+int device_suspend(pm_message_t state)
+{
+ int error = 0;
+
+ might_sleep();
+ mutex_lock(&dpm_mtx);
+ mutex_lock(&dpm_list_mtx);
+ while (!list_empty(&dpm_active) && error == 0) {
+ struct list_head * entry = dpm_active.prev;
+ struct device * dev = to_device(entry);
+
+ get_device(dev);
+ mutex_unlock(&dpm_list_mtx);
+
+ error = suspend_device(dev, state);
+
+ mutex_lock(&dpm_list_mtx);
+
+ /* Check if the device got removed */
+ if (!list_empty(&dev->power.entry)) {
+ /* Move it to the dpm_off list */
+ if (!error)
+ list_move(&dev->power.entry, &dpm_off);
+ }
+ if (error)
+ printk(KERN_ERR "Could not suspend device %s: "
+ "error %d%s\n",
+ kobject_name(&dev->kobj), error,
+ error == -EAGAIN ? " (please convert to suspend_late)" : "");
+ put_device(dev);
+ }
+ mutex_unlock(&dpm_list_mtx);
+ if (error)
+ dpm_resume();
+
+ mutex_unlock(&dpm_mtx);
+ return error;
+}
+
+EXPORT_SYMBOL_GPL(device_suspend);
+
+/**
+ * device_power_down - Shut down special devices.
+ * @state: Power state to enter.
+ *
+ * Walk the dpm_off_irq list, calling ->power_down() for each device that
+ * couldn't power down the device with interrupts enabled. When we're
+ * done, power down system devices.
+ */
+
+int device_power_down(pm_message_t state)
+{
+ int error = 0;
+ struct device * dev;
+
+ while (!list_empty(&dpm_off)) {
+ struct list_head * entry = dpm_off.prev;
+
+ dev = to_device(entry);
+ error = suspend_device_late(dev, state);
+ if (error)
+ goto Error;
+ list_move(&dev->power.entry, &dpm_off_irq);
+ }
+
+ error = sysdev_suspend(state);
+ Done:
+ return error;
+ Error:
+ printk(KERN_ERR "Could not power down device %s: "
+ "error %d\n", kobject_name(&dev->kobj), error);
+ dpm_power_up();
+ goto Done;
+}
+
+EXPORT_SYMBOL_GPL(device_power_down);
+
+void __suspend_report_result(const char *function, void *fn, int ret)
+{
+ if (ret) {
+ printk(KERN_ERR "%s(): ", function);
+ print_fn_descriptor_symbol("%s() returns ", (unsigned long)fn);
+ printk("%d\n", ret);
+ }
+}
+EXPORT_SYMBOL_GPL(__suspend_report_result);
Index: usb-2.6/drivers/base/power/resume.c
===================================================================
--- usb-2.6.orig/drivers/base/power/resume.c
+++ /dev/null
@@ -1,149 +0,0 @@
-/*
- * resume.c - Functions for waking devices up.
- *
- * Copyright (c) 2003 Patrick Mochel
- * Copyright (c) 2003 Open Source Development Labs
- *
- * This file is released under the GPLv2
- *
- */
-
-#include <linux/device.h>
-#include <linux/resume-trace.h>
-#include "../base.h"
-#include "power.h"
-
-
-/**
- * resume_device - Restore state for one device.
- * @dev: Device.
- *
- */
-
-int resume_device(struct device * dev)
-{
- int error = 0;
-
- TRACE_DEVICE(dev);
- TRACE_RESUME(0);
-
- down(&dev->sem);
-
- if (dev->bus && dev->bus->resume) {
- dev_dbg(dev,"resuming\n");
- error = dev->bus->resume(dev);
- }
-
- if (!error && dev->type && dev->type->resume) {
- dev_dbg(dev,"resuming\n");
- error = dev->type->resume(dev);
- }
-
- if (!error && dev->class && dev->class->resume) {
- dev_dbg(dev,"class resume\n");
- error = dev->class->resume(dev);
- }
-
- up(&dev->sem);
-
- TRACE_RESUME(error);
- return error;
-}
-
-
-static int resume_device_early(struct device * dev)
-{
- int error = 0;
-
- TRACE_DEVICE(dev);
- TRACE_RESUME(0);
- if (dev->bus && dev->bus->resume_early) {
- dev_dbg(dev,"EARLY resume\n");
- error = dev->bus->resume_early(dev);
- }
- TRACE_RESUME(error);
- return error;
-}
-
-/*
- * Resume the devices that have either not gone through
- * the late suspend, or that did go through it but also
- * went through the early resume
- */
-void dpm_resume(void)
-{
- mutex_lock(&dpm_list_mtx);
- while(!list_empty(&dpm_off)) {
- struct list_head * entry = dpm_off.next;
- struct device * dev = to_device(entry);
-
- get_device(dev);
- list_move_tail(entry, &dpm_active);
-
- mutex_unlock(&dpm_list_mtx);
- resume_device(dev);
- mutex_lock(&dpm_list_mtx);
- put_device(dev);
- }
- mutex_unlock(&dpm_list_mtx);
-}
-
-
-/**
- * device_resume - Restore state of each device in system.
- *
- * Walk the dpm_off list, remove each entry, resume the device,
- * then add it to the dpm_active list.
- */
-
-void device_resume(void)
-{
- might_sleep();
- mutex_lock(&dpm_mtx);
- dpm_resume();
- mutex_unlock(&dpm_mtx);
-}
-
-EXPORT_SYMBOL_GPL(device_resume);
-
-
-/**
- * dpm_power_up - Power on some devices.
- *
- * Walk the dpm_off_irq list and power each device up. This
- * is used for devices that required they be powered down with
- * interrupts disabled. As devices are powered on, they are moved
- * to the dpm_active list.
- *
- * Interrupts must be disabled when calling this.
- */
-
-void dpm_power_up(void)
-{
- while(!list_empty(&dpm_off_irq)) {
- struct list_head * entry = dpm_off_irq.next;
- struct device * dev = to_device(entry);
-
- list_move_tail(entry, &dpm_off);
- resume_device_early(dev);
- }
-}
-
-
-/**
- * device_power_up - Turn on all devices that need special attention.
- *
- * Power on system devices then devices that required we shut them down
- * with interrupts disabled.
- * Called with interrupts disabled.
- */
-
-void device_power_up(void)
-{
- sysdev_resume();
- dpm_power_up();
-}
-
-EXPORT_SYMBOL_GPL(device_power_up);
-
-
Index: usb-2.6/drivers/base/power/suspend.c
===================================================================
--- usb-2.6.orig/drivers/base/power/suspend.c
+++ /dev/null
@@ -1,210 +0,0 @@
-/*
- * suspend.c - Functions for putting devices to sleep.
- *
- * Copyright (c) 2003 Patrick Mochel
- * Copyright (c) 2003 Open Source Development Labs
- *
- * This file is released under the GPLv2
- *
- */
-
-#include <linux/device.h>
-#include <linux/kallsyms.h>
-#include <linux/pm.h>
-#include "../base.h"
-#include "power.h"
-
-/*
- * The entries in the dpm_active list are in a depth first order, simply
- * because children are guaranteed to be discovered after parents, and
- * are inserted at the back of the list on discovery.
- *
- * All list on the suspend path are done in reverse order, so we operate
- * on the leaves of the device tree (or forests, depending on how you want
- * to look at it ;) first. As nodes are removed from the back of the list,
- * they are inserted into the front of their destintation lists.
- *
- * Things are the reverse on the resume path - iterations are done in
- * forward order, and nodes are inserted at the back of their destination
- * lists. This way, the ancestors will be accessed before their descendents.
- */
-
-static inline char *suspend_verb(u32 event)
-{
- switch (event) {
- case PM_EVENT_SUSPEND: return "suspend";
- case PM_EVENT_FREEZE: return "freeze";
- case PM_EVENT_PRETHAW: return "prethaw";
- default: return "(unknown suspend event)";
- }
-}
-
-
-static void
-suspend_device_dbg(struct device *dev, pm_message_t state, char *info)
-{
- dev_dbg(dev, "%s%s%s\n", info, suspend_verb(state.event),
- ((state.event == PM_EVENT_SUSPEND) && device_may_wakeup(dev)) ?
- ", may wakeup" : "");
-}
-
-/**
- * suspend_device - Save state of one device.
- * @dev: Device.
- * @state: Power state device is entering.
- */
-
-int suspend_device(struct device * dev, pm_message_t state)
-{
- int error = 0;
-
- down(&dev->sem);
- if (dev->power.power_state.event) {
- dev_dbg(dev, "PM: suspend %d-->%d\n",
- dev->power.power_state.event, state.event);
- }
-
- if (dev->class && dev->class->suspend) {
- suspend_device_dbg(dev, state, "class ");
- error = dev->class->suspend(dev, state);
- suspend_report_result(dev->class->suspend, error);
- }
-
- if (!error && dev->type && dev->type->suspend) {
- suspend_device_dbg(dev, state, "type ");
- error = dev->type->suspend(dev, state);
- suspend_report_result(dev->type->suspend, error);
- }
-
- if (!error && dev->bus && dev->bus->suspend) {
- suspend_device_dbg(dev, state, "");
- error = dev->bus->suspend(dev, state);
- suspend_report_result(dev->bus->suspend, error);
- }
- up(&dev->sem);
- return error;
-}
-
-
-/*
- * This is called with interrupts off, only a single CPU
- * running. We can't acquire a mutex or semaphore (and we don't
- * need the protection)
- */
-static int suspend_device_late(struct device *dev, pm_message_t state)
-{
- int error = 0;
-
- if (dev->bus && dev->bus->suspend_late) {
- suspend_device_dbg(dev, state, "LATE ");
- error = dev->bus->suspend_late(dev, state);
- suspend_report_result(dev->bus->suspend_late, error);
- }
- return error;
-}
-
-/**
- * device_suspend - Save state and stop all devices in system.
- * @state: Power state to put each device in.
- *
- * Walk the dpm_active list, call ->suspend() for each device, and move
- * it to the dpm_off list.
- *
- * (For historical reasons, if it returns -EAGAIN, that used to mean
- * that the device would be called again with interrupts disabled.
- * These days, we use the "suspend_late()" callback for that, so we
- * print a warning and consider it an error).
- *
- * If we get a different error, try and back out.
- *
- * If we hit a failure with any of the devices, call device_resume()
- * above to bring the suspended devices back to life.
- *
- */
-
-int device_suspend(pm_message_t state)
-{
- int error = 0;
-
- might_sleep();
- mutex_lock(&dpm_mtx);
- mutex_lock(&dpm_list_mtx);
- while (!list_empty(&dpm_active) && error == 0) {
- struct list_head * entry = dpm_active.prev;
- struct device * dev = to_device(entry);
-
- get_device(dev);
- mutex_unlock(&dpm_list_mtx);
-
- error = suspend_device(dev, state);
-
- mutex_lock(&dpm_list_mtx);
-
- /* Check if the device got removed */
- if (!list_empty(&dev->power.entry)) {
- /* Move it to the dpm_off list */
- if (!error)
- list_move(&dev->power.entry, &dpm_off);
- }
- if (error)
- printk(KERN_ERR "Could not suspend device %s: "
- "error %d%s\n",
- kobject_name(&dev->kobj), error,
- error == -EAGAIN ? " (please convert to suspend_late)" : "");
- put_device(dev);
- }
- mutex_unlock(&dpm_list_mtx);
- if (error)
- dpm_resume();
-
- mutex_unlock(&dpm_mtx);
- return error;
-}
-
-EXPORT_SYMBOL_GPL(device_suspend);
-
-/**
- * device_power_down - Shut down special devices.
- * @state: Power state to enter.
- *
- * Walk the dpm_off_irq list, calling ->power_down() for each device that
- * couldn't power down the device with interrupts enabled. When we're
- * done, power down system devices.
- */
-
-int device_power_down(pm_message_t state)
-{
- int error = 0;
- struct device * dev;
-
- while (!list_empty(&dpm_off)) {
- struct list_head * entry = dpm_off.prev;
-
- dev = to_device(entry);
- error = suspend_device_late(dev, state);
- if (error)
- goto Error;
- list_move(&dev->power.entry, &dpm_off_irq);
- }
-
- error = sysdev_suspend(state);
- Done:
- return error;
- Error:
- printk(KERN_ERR "Could not power down device %s: "
- "error %d\n", kobject_name(&dev->kobj), error);
- dpm_power_up();
- goto Done;
-}
-
-EXPORT_SYMBOL_GPL(device_power_down);
-
-void __suspend_report_result(const char *function, void *fn, int ret)
-{
- if (ret) {
- printk(KERN_ERR "%s(): ", function);
- print_fn_descriptor_symbol("%s() returns ", (unsigned long)fn);
- printk("%d\n", ret);
- }
-}
-EXPORT_SYMBOL_GPL(__suspend_report_result);