kernel/reboot: Add kernel_can_power_off()

Add kernel_can_power_off() helper that replaces open-coded checks of
the global pm_power_off variable. This is a necessary step towards
supporting chained power-off handlers.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Dmitry Osipenko 2022-05-10 02:32:15 +03:00 committed by Rafael J. Wysocki
parent 5d34b41aa4
commit 0e2110d2e9
2 changed files with 14 additions and 1 deletions

View File

@ -149,6 +149,7 @@ extern void kernel_restart_prepare(char *cmd);
extern void kernel_restart(char *cmd);
extern void kernel_halt(void);
extern void kernel_power_off(void);
extern bool kernel_can_power_off(void);
extern int C_A_D; /* for sysctl */
void ctrl_alt_del(void);

View File

@ -523,6 +523,18 @@ void do_kernel_power_off(void)
atomic_notifier_call_chain(&power_off_handler_list, 0, NULL);
}
/**
* kernel_can_power_off - check whether system can be powered off
*
* Returns true if power-off handler is registered and system can be
* powered off, false otherwise.
*/
bool kernel_can_power_off(void)
{
return !atomic_notifier_call_chain_is_empty(&power_off_handler_list);
}
EXPORT_SYMBOL_GPL(kernel_can_power_off);
/**
* kernel_power_off - power_off the system
*
@ -581,7 +593,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
/* Instead of trying to make the power_off code look like
* halt when pm_power_off is not set do it the easy way.
*/
if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !kernel_can_power_off())
cmd = LINUX_REBOOT_CMD_HALT;
mutex_lock(&system_transition_mutex);