[SPARC]: Add sysctl to control serial console power-off restrictions.

arch/sparc/kernel/process.c

@@ -55,6 +55,12 @@ void (*pm_idle)(void);
  */
 void (*pm_power_off)(void);
 
+/*
+ * sysctl - toggle power-off restriction for serial console 
+ * systems in machine_power_off()
+ */
+int scons_pwroff = 1;
+
 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
 
 struct task_struct *last_task_used_math = NULL;
@@ -186,7 +192,7 @@ EXPORT_SYMBOL(machine_restart);
 void machine_power_off(void)
 {
 #ifdef CONFIG_SUN_AUXIO
-	if (auxio_power_register && !serial_console)
+	if (auxio_power_register && (!serial_console || scons_pwroff))
 		*auxio_power_register |= AUXIO_POWER_OFF;
 #endif
 	machine_halt();

arch/sparc64/kernel/power.c

@@ -20,6 +20,12 @@
 #define __KERNEL_SYSCALLS__
 #include <linux/unistd.h>
 
+/*
+ * sysctl - toggle power-off restriction for serial console 
+ * systems in machine_power_off()
+ */
+int scons_pwroff = 1; 
+
 #ifdef CONFIG_PCI
 static unsigned long power_reg = 0UL;
 
@@ -44,7 +50,7 @@ static void (*poweroff_method)(void) = machine_alt_power_off;
 
 void machine_power_off(void)
 {
-	if (!serial_console) {
+	if (!serial_console || scons_pwroff) {
 #ifdef CONFIG_PCI
 		if (power_reg != 0UL) {
 			/* Both register bits seem to have the

include/linux/sysctl.h

@@ -131,6 +131,7 @@ enum
 	KERN_PRINTK_RATELIMIT_BURST=61,	/* int: tune printk ratelimiting */
 	KERN_PTY=62,		/* dir: pty driver */
 	KERN_NGROUPS_MAX=63,	/* int: NGROUPS_MAX */
+	KERN_SPARC_SCONS_PWROFF=64, /* int: serial console power-off halt */
 };
 
 

kernel/sysctl.c

@@ -93,6 +93,7 @@ extern int sem_ctls[];
 #ifdef __sparc__
 extern char reboot_command [];
 extern int stop_a_enabled;
+extern int scons_pwroff;
 #endif
 
 #ifdef __hppa__
@@ -325,6 +326,14 @@ static ctl_table kern_table[] = {
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec,
 	},
+	{
+		.ctl_name	= KERN_SPARC_SCONS_PWROFF,
+		.procname	= "scons-poweroff",
+		.data		= &scons_pwroff,
+		.maxlen		= sizeof (int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
 #endif
 #ifdef __hppa__
 	{