Re: reboot vs poweroff

Eric W. Biederman
2005-09-10T21:07:29Z

"Brown, Len" <len.brown@intel.com> writes:

>
>>Patch tested and works fine here. You should probably make a
>>note in the bugzilla so we don't get a conflicting merge
>>from the ACPI folks.
>
> One might also consider that it would be a good idea to
> send patches that break ACPI files to the ACPI maintainer
> and acpi-devel@lists.sourceforge.net before sending them
> to Linus...

OK hopefully this is my final version of this bug fix.

Eric

diff --git a/include/linux/reboot.h b/include/linux/reboot.h
--- a/include/linux/reboot.h
+++ b/include/linux/reboot.h
@@ -59,6 +59,10 @@ extern void machine_crash_shutdown(struc
* Architecture independent implemenations of sys_reboot commands.
*/

+extern void kernel_restart_prepare(char *cmd);
+extern void kernel_halt_prepare(void);
+extern void kernel_power_off_prepare(void);
+
extern void kernel_restart(char *cmd);
extern void kernel_halt(void);
extern void kernel_power_off(void);
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -17,12 +17,12 @@
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/mount.h>
+#include <linux/pm.h>

#include "power.h"

extern suspend_disk_method_t pm_disk_mode;
-extern struct pm_ops * pm_ops;

extern int swsusp_suspend(void);
extern int swsusp_write(void);
@@ -49,13 +49,11 @@ dev_t swsusp_resume_device;

static void power_down(suspend_disk_method_t mode)
{
- unsigned long flags;
int error = 0;

- local_irq_save(flags);
switch(mode) {
case PM_DISK_PLATFORM:
- device_shutdown();
+ kernel_power_off_prepare();
error = pm_ops->enter(PM_SUSPEND_DISK);
break;
case PM_DISK_SHUTDOWN:
diff --git a/kernel/sys.c b/kernel/sys.c
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -361,17 +361,35 @@ out_unlock:
return retval;
}

+/**
+ * emergency_restart - reboot the system
+ *
+ * Without shutting down any hardware or taking any locks
+ * reboot the system. This is called when we know we are in
+ * trouble so this is our best effort to reboot. This is
+ * safe to call in interrupt context.
+ */
void emergency_restart(void)
{
machine_emergency_restart();
}
EXPORT_SYMBOL_GPL(emergency_restart);

-void kernel_restart(char *cmd)
+/**
+ * kernel_restart - reboot the system
+ *
+ * Shutdown everything and perform a clean reboot.
+ * This is not safe to call in interrupt context.
+ */
+void kernel_restart_prepare(char *cmd)
{
notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
system_state = SYSTEM_RESTART;
device_shutdown();
+}
+void kernel_restart(char *cmd)
+{
+ kernel_restart_prepare(cmd);
if (!cmd) {
printk(KERN_EMERG "Restarting system.\n");
} else {
@@ -382,6 +400,12 @@ void kernel_restart(char *cmd)
}
EXPORT_SYMBOL_GPL(kernel_restart);

+/**
+ * kernel_kexec - reboot the system
+ *
+ * Move into place and start executing a preloaded standalone
+ * executable. If nothing was preloaded return an error.
+ */
void kernel_kexec(void)
{
#ifdef CONFIG_KEXEC
@@ -390,9 +414,7 @@ void kernel_kexec(void)
if (!image) {
return;
}
- notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
- system_state = SYSTEM_RESTART;
- device_shutdown();
+ kernel_restart_prepare(NULL);
printk(KERN_EMERG "Starting new kernel\n");
machine_shutdown();
machine_kexec(image);
@@ -400,21 +422,39 @@ void kernel_kexec(void)
}
EXPORT_SYMBOL_GPL(kernel_kexec);

-void kernel_halt(void)
+/**
+ * kernel_halt - halt the system
+ *
+ * Shutdown everything and perform a clean system halt.
+ */
+void kernel_halt_prepare(void)
{
notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL);
system_state = SYSTEM_HALT;
device_shutdown();
+}
+void kernel_halt(void)
+{
+ kernel_halt_prepare();
printk(KERN_EMERG "System halted.\n");
machine_halt();
}
EXPORT_SYMBOL_GPL(kernel_halt);

-void kernel_power_off(void)
+/**
+ * kernel_power_off - power_off the system
+ *
+ * Shutdown everything and perform a clean system power_off.
+ */
+void kernel_power_off_prepare(void)
{
notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL);
system_state = SYSTEM_POWER_OFF;
device_shutdown();
+}
+void kernel_power_off(void)
+{
+ kernel_power_off_prepare();
printk(KERN_EMERG "Power down.\n");
machine_power_off();
}