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PM / Hibernate: Update kerneldoc comments in hibernate.c
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Some of the kerneldoc comments in kernel/power/hibernate.c are
outdated and some of them don't adhere to the kernel's standards.
Update them and make them look in a consistent way.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
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Rafael J. Wysocki committed May 24, 2011
1 parent 3542580 commit f42a981
Showing 1 changed file with 104 additions and 90 deletions.
194 changes: 104 additions & 90 deletions kernel/power/hibernate.c
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Original file line number Diff line number Diff line change
Expand Up @@ -54,10 +54,9 @@ static int hibernation_mode = HIBERNATION_SHUTDOWN;
static const struct platform_hibernation_ops *hibernation_ops;

/**
* hibernation_set_ops - set the global hibernate operations
* @ops: the hibernation operations to use in subsequent hibernation transitions
* hibernation_set_ops - Set the global hibernate operations.
* @ops: Hibernation operations to use in subsequent hibernation transitions.
*/

void hibernation_set_ops(const struct platform_hibernation_ops *ops)
{
if (ops && !(ops->begin && ops->end && ops->pre_snapshot
Expand Down Expand Up @@ -114,30 +113,31 @@ static int hibernation_test(int level) { return 0; }
#endif /* !CONFIG_PM_DEBUG */

/**
* platform_begin - tell the platform driver that we're starting
* hibernation
* platform_begin - Call platform to start hibernation.
* @platform_mode: Whether or not to use the platform driver.
*/

static int platform_begin(int platform_mode)
{
return (platform_mode && hibernation_ops) ?
hibernation_ops->begin() : 0;
}

/**
* platform_end - tell the platform driver that we've entered the
* working state
* platform_end - Call platform to finish transition to the working state.
* @platform_mode: Whether or not to use the platform driver.
*/

static void platform_end(int platform_mode)
{
if (platform_mode && hibernation_ops)
hibernation_ops->end();
}

/**
* platform_pre_snapshot - prepare the machine for hibernation using the
* platform driver if so configured and return an error code if it fails
* platform_pre_snapshot - Call platform to prepare the machine for hibernation.
* @platform_mode: Whether or not to use the platform driver.
*
* Use the platform driver to prepare the system for creating a hibernate image,
* if so configured, and return an error code if that fails.
*/

static int platform_pre_snapshot(int platform_mode)
Expand All @@ -147,71 +147,85 @@ static int platform_pre_snapshot(int platform_mode)
}

/**
* platform_leave - prepare the machine for switching to the normal mode
* of operation using the platform driver (called with interrupts disabled)
* platform_leave - Call platform to prepare a transition to the working state.
* @platform_mode: Whether or not to use the platform driver.
*
* Use the platform driver prepare to prepare the machine for switching to the
* normal mode of operation.
*
* This routine is called on one CPU with interrupts disabled.
*/

static void platform_leave(int platform_mode)
{
if (platform_mode && hibernation_ops)
hibernation_ops->leave();
}

/**
* platform_finish - switch the machine to the normal mode of operation
* using the platform driver (must be called after platform_prepare())
* platform_finish - Call platform to switch the system to the working state.
* @platform_mode: Whether or not to use the platform driver.
*
* Use the platform driver to switch the machine to the normal mode of
* operation.
*
* This routine must be called after platform_prepare().
*/

static void platform_finish(int platform_mode)
{
if (platform_mode && hibernation_ops)
hibernation_ops->finish();
}

/**
* platform_pre_restore - prepare the platform for the restoration from a
* hibernation image. If the restore fails after this function has been
* called, platform_restore_cleanup() must be called.
* platform_pre_restore - Prepare for hibernate image restoration.
* @platform_mode: Whether or not to use the platform driver.
*
* Use the platform driver to prepare the system for resume from a hibernation
* image.
*
* If the restore fails after this function has been called,
* platform_restore_cleanup() must be called.
*/

static int platform_pre_restore(int platform_mode)
{
return (platform_mode && hibernation_ops) ?
hibernation_ops->pre_restore() : 0;
}

/**
* platform_restore_cleanup - switch the platform to the normal mode of
* operation after a failing restore. If platform_pre_restore() has been
* called before the failing restore, this function must be called too,
* regardless of the result of platform_pre_restore().
* platform_restore_cleanup - Switch to the working state after failing restore.
* @platform_mode: Whether or not to use the platform driver.
*
* Use the platform driver to switch the system to the normal mode of operation
* after a failing restore.
*
* If platform_pre_restore() has been called before the failing restore, this
* function must be called too, regardless of the result of
* platform_pre_restore().
*/

static void platform_restore_cleanup(int platform_mode)
{
if (platform_mode && hibernation_ops)
hibernation_ops->restore_cleanup();
}

/**
* platform_recover - recover the platform from a failure to suspend
* devices.
* platform_recover - Recover from a failure to suspend devices.
* @platform_mode: Whether or not to use the platform driver.
*/

static void platform_recover(int platform_mode)
{
if (platform_mode && hibernation_ops && hibernation_ops->recover)
hibernation_ops->recover();
}

/**
* swsusp_show_speed - print the time elapsed between two events.
* @start: Starting event.
* @stop: Final event.
* @nr_pages - number of pages processed between @start and @stop
* @msg - introductory message to print
* swsusp_show_speed - Print time elapsed between two events during hibernation.
* @start: Starting event.
* @stop: Final event.
* @nr_pages: Number of memory pages processed between @start and @stop.
* @msg: Additional diagnostic message to print.
*/

void swsusp_show_speed(struct timeval *start, struct timeval *stop,
unsigned nr_pages, char *msg)
{
Expand All @@ -234,11 +248,14 @@ void swsusp_show_speed(struct timeval *start, struct timeval *stop,
}

/**
* create_image - freeze devices that need to be frozen with interrupts
* off, create the hibernation image and thaw those devices. Control
* reappears in this routine after a restore.
* create_image - Create a hibernation image.
* @platform_mode: Whether or not to use the platform driver.
*
* Execute device drivers' .freeze_noirq() callbacks, create a hibernation image
* and execute the drivers' .thaw_noirq() callbacks.
*
* Control reappears in this routine after the subsequent restore.
*/

static int create_image(int platform_mode)
{
int error;
Expand Down Expand Up @@ -303,14 +320,11 @@ static int create_image(int platform_mode)
}

/**
* hibernation_snapshot - quiesce devices and create the hibernation
* snapshot image.
* @platform_mode - if set, use the platform driver, if available, to
* prepare the platform firmware for the power transition.
* hibernation_snapshot - Quiesce devices and create a hibernation image.
* @platform_mode: If set, use platform driver to prepare for the transition.
*
* Must be called with pm_mutex held
* This routine must be called with pm_mutex held.
*/

int hibernation_snapshot(int platform_mode)
{
pm_message_t msg = PMSG_RECOVER;
Expand Down Expand Up @@ -370,13 +384,14 @@ int hibernation_snapshot(int platform_mode)
}

/**
* resume_target_kernel - prepare devices that need to be suspended with
* interrupts off, restore the contents of highmem that have not been
* restored yet from the image and run the low level code that will restore
* the remaining contents of memory and switch to the just restored target
* kernel.
* resume_target_kernel - Restore system state from a hibernation image.
* @platform_mode: Whether or not to use the platform driver.
*
* Execute device drivers' .freeze_noirq() callbacks, restore the contents of
* highmem that have not been restored yet from the image and run the low-level
* code that will restore the remaining contents of memory and switch to the
* just restored target kernel.
*/

static int resume_target_kernel(bool platform_mode)
{
int error;
Expand Down Expand Up @@ -444,14 +459,12 @@ static int resume_target_kernel(bool platform_mode)
}

/**
* hibernation_restore - quiesce devices and restore the hibernation
* snapshot image. If successful, control returns in hibernation_snaphot()
* @platform_mode - if set, use the platform driver, if available, to
* prepare the platform firmware for the transition.
* hibernation_restore - Quiesce devices and restore from a hibernation image.
* @platform_mode: If set, use platform driver to prepare for the transition.
*
* Must be called with pm_mutex held
* This routine must be called with pm_mutex held. If it is successful, control
* reappears in the restored target kernel in hibernation_snaphot().
*/

int hibernation_restore(int platform_mode)
{
int error;
Expand All @@ -471,10 +484,8 @@ int hibernation_restore(int platform_mode)
}

/**
* hibernation_platform_enter - enter the hibernation state using the
* platform driver (if available)
* hibernation_platform_enter - Power off the system using the platform driver.
*/

int hibernation_platform_enter(void)
{
int error;
Expand Down Expand Up @@ -545,12 +556,12 @@ int hibernation_platform_enter(void)
}

/**
* power_down - Shut the machine down for hibernation.
* power_down - Shut the machine down for hibernation.
*
* Use the platform driver, if configured so; otherwise try
* to power off or reboot.
* Use the platform driver, if configured, to put the system into the sleep
* state corresponding to hibernation, or try to power it off or reboot,
* depending on the value of hibernation_mode.
*/

static void power_down(void)
{
switch (hibernation_mode) {
Expand Down Expand Up @@ -587,9 +598,8 @@ static int prepare_processes(void)
}

/**
* hibernate - The granpappy of the built-in hibernation management
* hibernate - Carry out system hibernation, including saving the image.
*/

int hibernate(void)
{
int error;
Expand Down Expand Up @@ -667,17 +677,20 @@ int hibernate(void)


/**
* software_resume - Resume from a saved image.
* software_resume - Resume from a saved hibernation image.
*
* This routine is called as a late initcall, when all devices have been
* discovered and initialized already.
*
* Called as a late_initcall (so all devices are discovered and
* initialized), we call swsusp to see if we have a saved image or not.
* If so, we quiesce devices, the restore the saved image. We will
* return above (in hibernate() ) if everything goes well.
* Otherwise, we fail gracefully and return to the normally
* scheduled program.
* The image reading code is called to see if there is a hibernation image
* available for reading. If that is the case, devices are quiesced and the
* contents of memory is restored from the saved image.
*
* If this is successful, control reappears in the restored target kernel in
* hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
* attempts to recover gracefully and make the kernel return to the normal mode
* of operation.
*/

static int software_resume(void)
{
int error;
Expand Down Expand Up @@ -807,30 +820,32 @@ static const char * const hibernation_modes[] = {
[HIBERNATION_TESTPROC] = "testproc",
};

/**
* disk - Control hibernation mode
*
* Suspend-to-disk can be handled in several ways. We have a few options
* for putting the system to sleep - using the platform driver (e.g. ACPI
* or other hibernation_ops), powering off the system or rebooting the
* system (for testing) as well as the two test modes.
/*
* /sys/power/disk - Control hibernation mode.
*
* The system can support 'platform', and that is known a priori (and
* encoded by the presence of hibernation_ops). However, the user may
* choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
* test modes, 'test' or 'testproc'.
* Hibernation can be handled in several ways. There are a few different ways
* to put the system into the sleep state: using the platform driver (e.g. ACPI
* or other hibernation_ops), powering it off or rebooting it (for testing
* mostly), or using one of the two available test modes.
*
* show() will display what the mode is currently set to.
* store() will accept one of
* The sysfs file /sys/power/disk provides an interface for selecting the
* hibernation mode to use. Reading from this file causes the available modes
* to be printed. There are 5 modes that can be supported:
*
* 'platform'
* 'shutdown'
* 'reboot'
* 'test'
* 'testproc'
*
* It will only change to 'platform' if the system
* supports it (as determined by having hibernation_ops).
* If a platform hibernation driver is in use, 'platform' will be supported
* and will be used by default. Otherwise, 'shutdown' will be used by default.
* The selected option (i.e. the one corresponding to the current value of
* hibernation_mode) is enclosed by a square bracket.
*
* To select a given hibernation mode it is necessary to write the mode's
* string representation (as returned by reading from /sys/power/disk) back
* into /sys/power/disk.
*/

static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
Expand Down Expand Up @@ -863,7 +878,6 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
return buf-start;
}


static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
Expand Down

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