xtensa: drop platform_halt and platform_power_off

Instead of using xtensa-specific platform_halt and platform_power_off
callbacks use do_kernel_power_off in the machine_halt and
machine_power_off and reimplement existing platform_halt and
platform_power_off users with register_sys_off_handler.

Drop platform_halt and platform_power_off declarations and default
implementations.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/include/asm/platform.h

@@ -27,16 +27,6 @@ extern void platform_init(bp_tag_t*);
  */
 extern void platform_setup (char **);
 
-/*
- * platform_halt is called to stop the system and halt.
- */
-extern void platform_halt (void);
-
-/*
- * platform_power_off is called to stop the system and power it off.
- */
-extern void platform_power_off (void);
-
 /*
  * platform_idle is called from the idle function.
  */

arch/xtensa/kernel/platform.c

@@ -28,8 +28,6 @@
 
 _F(void, init, (bp_tag_t *first), { });
 _F(void, setup, (char** cmd), { });
-_F(void, halt, (void), { while(1); });
-_F(void, power_off, (void), { while(1); });
 _F(void, idle, (void), { __asm__ __volatile__ ("waiti 0" ::: "memory"); });
 
 #ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT

arch/xtensa/kernel/setup.c

@@ -533,14 +533,20 @@ void machine_restart(char * cmd)
 
 void machine_halt(void)
 {
-	platform_halt();
-	while (1);
+	local_irq_disable();
+	smp_send_stop();
+	do_kernel_power_off();
+	while (1)
+		cpu_relax();
 }
 
 void machine_power_off(void)
 {
-	platform_power_off();
-	while (1);
+	local_irq_disable();
+	smp_send_stop();
+	do_kernel_power_off();
+	while (1)
+		cpu_relax();
 }
 #ifdef CONFIG_PROC_FS
 

arch/xtensa/platforms/iss/setup.c

@@ -25,16 +25,11 @@
 #include <platform/simcall.h>
 
 
-void platform_halt(void)
-{
-	pr_info(" ** Called platform_halt() **\n");
-	simc_exit(0);
-}
-
-void platform_power_off(void)
+static int iss_power_off(struct sys_off_data *unused)
 {
 	pr_info(" ** Called platform_power_off() **\n");
 	simc_exit(0);
+	return NOTIFY_DONE;
 }
 
 static int iss_restart(struct notifier_block *this,
@@ -90,4 +85,7 @@ void __init platform_setup(char **p_cmdline)
 
 	atomic_notifier_chain_register(&panic_notifier_list, &iss_panic_block);
 	register_restart_handler(&iss_restart_block);
+	register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
+				 SYS_OFF_PRIO_PLATFORM,
+				 iss_power_off, NULL);
 }

arch/xtensa/platforms/xt2000/setup.c

@@ -42,18 +42,12 @@ static void led_print (int f, char *s)
 		    break;
 }
 
-void platform_halt(void)
-{
-	led_print (0, "  HALT  ");
-	local_irq_disable();
-	while (1);
-}
-
-void platform_power_off(void)
+static int xt2000_power_off(struct sys_off_data *unused)
 {
 	led_print (0, "POWEROFF");
 	local_irq_disable();
 	while (1);
+	return NOTIFY_DONE;
 }
 
 static int xt2000_restart(struct notifier_block *this,
@@ -147,6 +141,9 @@ static int __init xt2000_setup_devinit(void)
 	platform_device_register(&xt2000_sonic_device);
 	mod_timer(&heartbeat_timer, jiffies + HZ / 2);
 	register_restart_handler(&xt2000_restart_block);
+	register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
+				 SYS_OFF_PRIO_DEFAULT,
+				 xt2000_power_off, NULL);
 	return 0;
 }
 

arch/xtensa/platforms/xtfpga/setup.c

@@ -33,20 +33,13 @@
 #include <platform/lcd.h>
 #include <platform/hardware.h>
 
-void platform_halt(void)
-{
-	lcd_disp_at_pos(" HALT ", 0);
-	local_irq_disable();
-	while (1)
-		cpu_relax();
-}
-
-void platform_power_off(void)
+static int xtfpga_power_off(struct sys_off_data *unused)
 {
 	lcd_disp_at_pos("POWEROFF", 0);
 	local_irq_disable();
 	while (1)
 		cpu_relax();
+	return NOTIFY_DONE;
 }
 
 static int xtfpga_restart(struct notifier_block *this,
@@ -79,6 +72,9 @@ void __init platform_calibrate_ccount(void)
 static void __init xtfpga_register_handlers(void)
 {
 	register_restart_handler(&xtfpga_restart_block);
+	register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
+				 SYS_OFF_PRIO_DEFAULT,
+				 xtfpga_power_off, NULL);
 }
 
 #ifdef CONFIG_USE_OF