[PATCH v2 08/47] kernel: Move pm_power_off to common code

[Guenter Roeck <linux@roeck-us.net>]

pm_power_off is defined for all architectures. Move it to common code.

Have all architectures call do_kernel_power_off instead of pm_power_off.
Some architectures point pm_power_off to machine_power_off. For those,
call do_kernel_power_off from machine_power_off instead.

Acked-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Hirokazu Takata <takata@linux-m32r.org>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Acked-by: Richard Weinberger <richard@nod.at>
Acked-by: Xuetao Guan <gxt@mprc.pku.edu.cn>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2:
- do_kernel_poweroff -> do_kernel_power_off
- have_kernel_poweroff -> have_kernel_power_off

 arch/alpha/kernel/process.c        |  9 +++------
 arch/arc/kernel/reset.c            |  5 +----
 arch/arm/kernel/process.c          |  5 +----
 arch/arm64/kernel/process.c        |  5 +----
 arch/avr32/kernel/process.c        |  6 +-----
 arch/blackfin/kernel/process.c     |  3 ---
 arch/blackfin/kernel/reboot.c      |  2 ++
 arch/c6x/kernel/process.c          |  9 +--------
 arch/cris/kernel/process.c         |  4 +---
 arch/frv/kernel/process.c          |  5 ++---
 arch/hexagon/kernel/reset.c        |  5 ++---
 arch/ia64/kernel/process.c         |  5 +----
 arch/m32r/kernel/process.c         |  8 ++++----
 arch/m68k/kernel/process.c         |  6 +-----
 arch/metag/kernel/process.c        |  6 +-----
 arch/microblaze/kernel/process.c   |  3 ---
 arch/microblaze/kernel/reset.c     |  1 +
 arch/mips/kernel/reset.c           |  6 +-----
 arch/mn10300/kernel/process.c      |  8 ++------
 arch/openrisc/kernel/process.c     |  8 +++++---
 arch/parisc/kernel/process.c       |  8 ++++----
 arch/powerpc/kernel/setup-common.c |  6 +++---
 arch/s390/kernel/setup.c           |  8 ++------
 arch/score/kernel/process.c        |  8 ++++----
 arch/sh/kernel/reboot.c            |  6 +-----
 arch/sparc/kernel/process_32.c     | 10 ++--------
 arch/sparc/kernel/reboot.c         |  8 ++------
 arch/tile/kernel/reboot.c          |  7 +++----
 arch/um/kernel/reboot.c            |  2 --
 arch/unicore32/kernel/process.c    |  9 +--------
 arch/x86/kernel/reboot.c           | 11 +++--------
 arch/x86/xen/enlighten.c           |  3 +--
 arch/xtensa/kernel/process.c       |  4 ----
 drivers/parisc/power.c             |  3 +--
 kernel/power/poweroff_handler.c    |  8 ++++++++
 kernel/reboot.c                    |  4 ++--
 36 files changed, 68 insertions(+), 146 deletions(-)

diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 1941a07..81c43f8 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -24,6 +24,7 @@
 #include <linux/vt.h>
 #include <linux/mman.h>
 #include <linux/elfcore.h>
+#include <linux/pm.h>
 #include <linux/reboot.h>
 #include <linux/tty.h>
 #include <linux/console.h>
@@ -40,12 +41,6 @@
 #include "proto.h"
 #include "pci_impl.h"
 
-/*
- * Power off function, if any
- */
-void (*pm_power_off)(void) = machine_power_off;
-EXPORT_SYMBOL(pm_power_off);
-
 #ifdef CONFIG_ALPHA_WTINT
 /*
  * Sleep the CPU.
@@ -184,6 +179,8 @@ machine_halt(void)
 void
 machine_power_off(void)
 {
+	do_kernel_power_off();
+
 	common_shutdown(LINUX_REBOOT_CMD_POWER_OFF, NULL);
 }
 
diff --git a/arch/arc/kernel/reset.c b/arch/arc/kernel/reset.c
index 2768fa1..0758d9d 100644
--- a/arch/arc/kernel/reset.c
+++ b/arch/arc/kernel/reset.c
@@ -26,9 +26,6 @@ void machine_restart(char *__unused)
 
 void machine_power_off(void)
 {
-	/* FIXME ::  power off ??? */
+	do_kernel_power_off();
 	machine_halt();
 }
-
-void (*pm_power_off) (void) = NULL;
-EXPORT_SYMBOL(pm_power_off);
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index fe972a2..aa3f656 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -117,8 +117,6 @@ void soft_restart(unsigned long addr)
 /*
  * Function pointers to optional machine specific functions
  */
-void (*pm_power_off)(void);
-EXPORT_SYMBOL(pm_power_off);
 
 void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
 
@@ -205,8 +203,7 @@ void machine_power_off(void)
 	local_irq_disable();
 	smp_send_stop();
 
-	if (pm_power_off)
-		pm_power_off();
+	do_kernel_power_off();
 }
 
 /*
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index c3065db..46a483a 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -68,8 +68,6 @@ void soft_restart(unsigned long addr)
 /*
  * Function pointers to optional machine specific functions
  */
-void (*pm_power_off)(void);
-EXPORT_SYMBOL_GPL(pm_power_off);
 
 void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
 
@@ -129,8 +127,7 @@ void machine_power_off(void)
 {
 	local_irq_disable();
 	smp_send_stop();
-	if (pm_power_off)
-		pm_power_off();
+	do_kernel_power_off();
 }
 
 /*
diff --git a/arch/avr32/kernel/process.c b/arch/avr32/kernel/process.c
index 42a53e74..529c1f6 100644
--- a/arch/avr32/kernel/process.c
+++ b/arch/avr32/kernel/process.c
@@ -23,9 +23,6 @@
 
 #include <mach/pm.h>
 
-void (*pm_power_off)(void);
-EXPORT_SYMBOL(pm_power_off);
-
 /*
  * This file handles the architecture-dependent parts of process handling..
  */
@@ -48,8 +45,7 @@ void machine_halt(void)
 
 void machine_power_off(void)
 {
-	if (pm_power_off)
-		pm_power_off();
+	do_kernel_power_off();
 }
 
 void machine_restart(char *cmd)
diff --git a/arch/blackfin/kernel/process.c b/arch/blackfin/kernel/process.c
index 4aa5545..812dd83 100644
--- a/arch/blackfin/kernel/process.c
+++ b/arch/blackfin/kernel/process.c
@@ -39,9 +39,6 @@ int nr_l1stack_tasks;
 void *l1_stack_base;
 unsigned long l1_stack_len;
 
-void (*pm_power_off)(void) = NULL;
-EXPORT_SYMBOL(pm_power_off);
-
 /*
  * The idle loop on BFIN
  */
diff --git a/arch/blackfin/kernel/reboot.c b/arch/blackfin/kernel/reboot.c
index c4f50a3..387d610 100644
--- a/arch/blackfin/kernel/reboot.c
+++ b/arch/blackfin/kernel/reboot.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/interrupt.h>
+#include <linux/pm.h>
 #include <asm/bfin-global.h>
 #include <asm/reboot.h>
 #include <asm/bfrom.h>
@@ -106,6 +107,7 @@ void machine_halt(void)
 __attribute__((weak))
 void native_machine_power_off(void)
 {
+	do_kernel_power_off();
 	idle_with_irq_disabled();
 }
 
diff --git a/arch/c6x/kernel/process.c b/arch/c6x/kernel/process.c
index 57d2ea8..edf7e5a 100644
--- a/arch/c6x/kernel/process.c
+++ b/arch/c6x/kernel/process.c
@@ -27,12 +27,6 @@ void	(*c6x_halt)(void);
 extern asmlinkage void ret_from_fork(void);
 extern asmlinkage void ret_from_kernel_thread(void);
 
-/*
- * power off function, if any
- */
-void (*pm_power_off)(void);
-EXPORT_SYMBOL(pm_power_off);
-
 void arch_cpu_idle(void)
 {
 	unsigned long tmp;
@@ -73,8 +67,7 @@ void machine_halt(void)
 
 void machine_power_off(void)
 {
-	if (pm_power_off)
-		pm_power_off();
+	do_kernel_power_off();
 	halt_loop();
 }
 
diff --git a/arch/cris/kernel/process.c b/arch/cris/kernel/process.c
index b78498e..9ebd76b 100644
--- a/arch/cris/kernel/process.c
+++ b/arch/cris/kernel/process.c
@@ -31,9 +31,6 @@
 
 extern void default_idle(void);
 
-void (*pm_power_off)(void);
-EXPORT_SYMBOL(pm_power_off);
-
 void arch_cpu_idle(void)
 {
 	default_idle();
@@ -60,6 +57,7 @@ void machine_halt(void)
 
 void machine_power_off(void)
 {
+	do_kernel_power_off();
 }
 
 /*
diff --git a/arch/frv/kernel/process.c b/arch/frv/kernel/process.c
index 5d40aeb77..502dabb 100644
--- a/arch/frv/kernel/process.c
+++ b/arch/frv/kernel/process.c
@@ -42,9 +42,6 @@ asmlinkage void ret_from_kernel_thread(void);
 
 #include <asm/pgalloc.h>
 
-void (*pm_power_off)(void);
-EXPORT_SYMBOL(pm_power_off);
-
 static void core_sleep_idle(void)
 {
 #ifdef LED_DEBUG_SLEEP
@@ -107,6 +104,8 @@ void machine_power_off(void)
 	gdbstub_exit(0);
 #endif
 
+	do_kernel_power_off();
+
 	for (;;);
 }
 
diff --git a/arch/hexagon/kernel/reset.c b/arch/hexagon/kernel/reset.c
index 76483c1..6f607b6 100644
--- a/arch/hexagon/kernel/reset.c
+++ b/arch/hexagon/kernel/reset.c
@@ -16,11 +16,13 @@
  * 02110-1301, USA.
  */
 
+#include <linux/pm.h>
 #include <linux/smp.h>
 #include <asm/hexagon_vm.h>
 
 void machine_power_off(void)
 {
+	do_kernel_power_off();
 	smp_send_stop();
 	__vmstop();
 }
@@ -32,6 +34,3 @@ void machine_halt(void)
 void machine_restart(char *cmd)
 {
 }
-
-void (*pm_power_off)(void) = NULL;
-EXPORT_SYMBOL(pm_power_off);
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index b515149..88121a2 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -57,8 +57,6 @@ void (*ia64_mark_idle)(int);
 
 unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
 EXPORT_SYMBOL(boot_option_idle_override);
-void (*pm_power_off) (void);
-EXPORT_SYMBOL(pm_power_off);
 
 void
 ia64_do_show_stack (struct unw_frame_info *info, void *arg)
@@ -675,8 +673,7 @@ machine_halt (void)
 void
 machine_power_off (void)
 {
-	if (pm_power_off)
-		pm_power_off();
+	do_kernel_power_off();
 	machine_halt();
 }
 
diff --git a/arch/m32r/kernel/process.c b/arch/m32r/kernel/process.c
index e69221d..65a037e 100644
--- a/arch/m32r/kernel/process.c
+++ b/arch/m32r/kernel/process.c
@@ -23,6 +23,7 @@
 #include <linux/fs.h>
 #include <linux/slab.h>
 #include <linux/module.h>
+#include <linux/pm.h>
 #include <linux/ptrace.h>
 #include <linux/unistd.h>
 #include <linux/hardirq.h>
@@ -44,9 +45,6 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
 	return tsk->thread.lr;
 }
 
-void (*pm_power_off)(void) = NULL;
-EXPORT_SYMBOL(pm_power_off);
-
 void machine_restart(char *__unused)
 {
 #if defined(CONFIG_PLAT_MAPPI3)
@@ -67,7 +65,9 @@ void machine_halt(void)
 
 void machine_power_off(void)
 {
-	/* M32R_FIXME */
+	do_kernel_power_off();
+	for (;;)
+		;
 }
 
 void show_regs(struct pt_regs * regs)
diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
index afe3d6e..bbc0a63 100644
--- a/arch/m68k/kernel/process.c
+++ b/arch/m68k/kernel/process.c
@@ -78,14 +78,10 @@ void machine_halt(void)
 
 void machine_power_off(void)
 {
-	if (pm_power_off)
-		pm_power_off();
+	do_kernel_power_off();
 	for (;;);
 }
 
-void (*pm_power_off)(void) = machine_power_off;
-EXPORT_SYMBOL(pm_power_off);
-
 void show_regs(struct pt_regs * regs)
 {
 	printk("\n");
diff --git a/arch/metag/kernel/process.c b/arch/metag/kernel/process.c
index 483dff9..8d95773 100644
--- a/arch/metag/kernel/process.c
+++ b/arch/metag/kernel/process.c
@@ -67,9 +67,6 @@ void arch_cpu_idle_dead(void)
 }
 #endif
 
-void (*pm_power_off)(void);
-EXPORT_SYMBOL(pm_power_off);
-
 void (*soc_restart)(char *cmd);
 void (*soc_halt)(void);
 
@@ -90,8 +87,7 @@ void machine_halt(void)
 
 void machine_power_off(void)
 {
-	if (pm_power_off)
-		pm_power_off();
+	do_kernel_power_off();
 	smp_send_stop();
 	hard_processor_halt(HALT_OK);
 }
diff --git a/arch/microblaze/kernel/process.c b/arch/microblaze/kernel/process.c
index b2dd371..0ebca36 100644
--- a/arch/microblaze/kernel/process.c
+++ b/arch/microblaze/kernel/process.c
@@ -44,9 +44,6 @@ void show_regs(struct pt_regs *regs)
 				regs->msr, regs->ear, regs->esr, regs->fsr);
 }
 
-void (*pm_power_off)(void) = NULL;
-EXPORT_SYMBOL(pm_power_off);
-
 void flush_thread(void)
 {
 }
diff --git a/arch/microblaze/kernel/reset.c b/arch/microblaze/kernel/reset.c
index fbe58c6..2c6b32c 100644
--- a/arch/microblaze/kernel/reset.c
+++ b/arch/microblaze/kernel/reset.c
@@ -103,6 +103,7 @@ void machine_halt(void)
 void machine_power_off(void)
 {
 	pr_notice("Machine power off...\n");
+	do_kernel_power_off();
 	while (1)
 		;
 }
diff --git a/arch/mips/kernel/reset.c b/arch/mips/kernel/reset.c
index 07fc524..09e74d2 100644
--- a/arch/mips/kernel/reset.c
+++ b/arch/mips/kernel/reset.c
@@ -21,9 +21,6 @@
  */
 void (*_machine_restart)(char *command);
 void (*_machine_halt)(void);
-void (*pm_power_off)(void);
-
-EXPORT_SYMBOL(pm_power_off);
 
 void machine_restart(char *command)
 {
@@ -39,6 +36,5 @@ void machine_halt(void)
 
 void machine_power_off(void)
 {
-	if (pm_power_off)
-		pm_power_off();
+	do_kernel_power_off();
 }
diff --git a/arch/mn10300/kernel/process.c b/arch/mn10300/kernel/process.c
index 3707da5..c78b2eb 100644
--- a/arch/mn10300/kernel/process.c
+++ b/arch/mn10300/kernel/process.c
@@ -20,6 +20,7 @@
 #include <linux/user.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
+#include <linux/pm.h>
 #include <linux/reboot.h>
 #include <linux/percpu.h>
 #include <linux/err.h>
@@ -45,12 +46,6 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
 }
 
 /*
- * power off function, if any
- */
-void (*pm_power_off)(void);
-EXPORT_SYMBOL(pm_power_off);
-
-/*
  * On SMP it's slightly faster (but much more power-consuming!)
  * to poll the ->work.need_resched flag instead of waiting for the
  * cross-CPU IPI to arrive. Use this option with caution.
@@ -93,6 +88,7 @@ void machine_power_off(void)
 #ifdef CONFIG_KERNEL_DEBUGGER
 	gdbstub_exit(0);
 #endif
+	do_kernel_power_off();
 }
 
 void show_regs(struct pt_regs *regs)
diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
index 386af25..494afd2 100644
--- a/arch/openrisc/kernel/process.c
+++ b/arch/openrisc/kernel/process.c
@@ -25,6 +25,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/mm.h>
+#include <linux/pm.h>
 #include <linux/stddef.h>
 #include <linux/unistd.h>
 #include <linux/ptrace.h>
@@ -51,7 +52,7 @@
  */
 struct thread_info *current_thread_info_set[NR_CPUS] = { &init_thread_info, };
 
-void machine_restart(void)
+void machine_restart(char *cmd)
 {
 	printk(KERN_INFO "*** MACHINE RESTART ***\n");
 	__asm__("l.nop 1");
@@ -72,11 +73,12 @@ void machine_halt(void)
 void machine_power_off(void)
 {
 	printk(KERN_INFO "*** MACHINE POWER OFF ***\n");
+
+	do_kernel_power_off();
+
 	__asm__("l.nop 1");
 }
 
-void (*pm_power_off) (void) = machine_power_off;
-
 /*
  * When a process does an "exec", machine state like FPU and debug
  * registers need to be reset.  This is a hook function for that.
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index 0bbbf0d..3f5d14a 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -41,6 +41,7 @@
 #include <linux/fs.h>
 #include <linux/module.h>
 #include <linux/personality.h>
+#include <linux/pm.h>
 #include <linux/ptrace.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
@@ -133,7 +134,9 @@ void machine_power_off(void)
 	pdc_soft_power_button(0);
 	
 	pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
-		
+
+	do_kernel_power_off();
+
 	/* It seems we have no way to power the system off via
 	 * software. The user has to press the button himself. */
 
@@ -141,9 +144,6 @@ void machine_power_off(void)
 	       "Please power this system off now.");
 }
 
-void (*pm_power_off)(void) = machine_power_off;
-EXPORT_SYMBOL(pm_power_off);
-
 /*
  * Free current thread data structures etc..
  */
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 1362cd6..5b7a851 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -141,6 +141,9 @@ void machine_power_off(void)
 	machine_shutdown();
 	if (ppc_md.power_off)
 		ppc_md.power_off();
+
+	do_kernel_power_off();
+
 #ifdef CONFIG_SMP
 	smp_send_stop();
 #endif
@@ -151,9 +154,6 @@ void machine_power_off(void)
 /* Used by the G5 thermal driver */
 EXPORT_SYMBOL_GPL(machine_power_off);
 
-void (*pm_power_off)(void) = machine_power_off;
-EXPORT_SYMBOL_GPL(pm_power_off);
-
 void machine_halt(void)
 {
 	machine_shutdown();
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index e80d9ff..267e025 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -263,13 +263,9 @@ void machine_power_off(void)
 		 */
 		console_unblank();
 	_machine_power_off();
-}
 
-/*
- * Dummy power off function.
- */
-void (*pm_power_off)(void) = machine_power_off;
-EXPORT_SYMBOL_GPL(pm_power_off);
+	do_kernel_power_off();
+}
 
 static int __init early_parse_mem(char *p)
 {
diff --git a/arch/score/kernel/process.c b/arch/score/kernel/process.c
index a1519ad3..b76ea67 100644
--- a/arch/score/kernel/process.c
+++ b/arch/score/kernel/process.c
@@ -29,9 +29,6 @@
 #include <linux/pm.h>
 #include <linux/rcupdate.h>
 
-void (*pm_power_off)(void);
-EXPORT_SYMBOL(pm_power_off);
-
 /* If or when software machine-restart is implemented, add code here. */
 void machine_restart(char *command) {}
 
@@ -39,7 +36,10 @@ void machine_restart(char *command) {}
 void machine_halt(void) {}
 
 /* If or when software machine-power-off is implemented, add code here. */
-void machine_power_off(void) {}
+void machine_power_off(void)
+{
+	do_kernel_power_off();
+}
 
 void ret_from_fork(void);
 void ret_from_kernel_thread(void);
diff --git a/arch/sh/kernel/reboot.c b/arch/sh/kernel/reboot.c
index 04afe5b..065de12 100644
--- a/arch/sh/kernel/reboot.c
+++ b/arch/sh/kernel/reboot.c
@@ -11,9 +11,6 @@
 #include <asm/tlbflush.h>
 #include <asm/traps.h>
 
-void (*pm_power_off)(void);
-EXPORT_SYMBOL(pm_power_off);
-
 #ifdef CONFIG_SUPERH32
 static void watchdog_trigger_immediate(void)
 {
@@ -51,8 +48,7 @@ static void native_machine_shutdown(void)
 
 static void native_machine_power_off(void)
 {
-	if (pm_power_off)
-		pm_power_off();
+	do_kernel_power_off();
 }
 
 static void native_machine_halt(void)
diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c
index 50e7b62..cb8148a 100644
--- a/arch/sparc/kernel/process_32.c
+++ b/arch/sparc/kernel/process_32.c
@@ -48,14 +48,6 @@
  */
 void (*sparc_idle)(void);
 
-/* 
- * Power-off handler instantiation for pm.h compliance
- * This is done via auxio, but could be used as a fallback
- * handler when auxio is not present-- unused for now...
- */
-void (*pm_power_off)(void) = machine_power_off;
-EXPORT_SYMBOL(pm_power_off);
-
 /*
  * sysctl - toggle power-off restriction for serial console 
  * systems in machine_power_off()
@@ -112,6 +104,8 @@ void machine_power_off(void)
 		sbus_writeb(power_register, auxio_power_register);
 	}
 
+	do_kernel_power_off();
+
 	machine_halt();
 }
 
diff --git a/arch/sparc/kernel/reboot.c b/arch/sparc/kernel/reboot.c
index eba7d91..3c0bb03 100644
--- a/arch/sparc/kernel/reboot.c
+++ b/arch/sparc/kernel/reboot.c
@@ -16,17 +16,13 @@
  */
 int scons_pwroff = 1;
 
-/* This isn't actually used, it exists merely to satisfy the
- * reference in kernel/sys.c
- */
-void (*pm_power_off)(void) = machine_power_off;
-EXPORT_SYMBOL(pm_power_off);
-
 void machine_power_off(void)
 {
 	if (strcmp(of_console_device->type, "serial") || scons_pwroff)
 		prom_halt_power_off();
 
+	do_kernel_power_off();
+
 	prom_halt();
 }
 
diff --git a/arch/tile/kernel/reboot.c b/arch/tile/kernel/reboot.c
index 6c5d2c0..8ff4a7f 100644
--- a/arch/tile/kernel/reboot.c
+++ b/arch/tile/kernel/reboot.c
@@ -36,6 +36,9 @@ void machine_power_off(void)
 {
 	arch_local_irq_disable_all();
 	smp_send_stop();
+
+	do_kernel_power_off();
+
 	hv_power_off();
 }
 
@@ -45,7 +48,3 @@ void machine_restart(char *cmd)
 	smp_send_stop();
 	hv_restart((HV_VirtAddr) "vmlinux", (HV_VirtAddr) cmd);
 }
-
-/* No interesting distinction to be made here. */
-void (*pm_power_off)(void) = NULL;
-EXPORT_SYMBOL(pm_power_off);
diff --git a/arch/um/kernel/reboot.c b/arch/um/kernel/reboot.c
index ced8903..a82ef28 100644
--- a/arch/um/kernel/reboot.c
+++ b/arch/um/kernel/reboot.c
@@ -11,8 +11,6 @@
 #include <os.h>
 #include <skas.h>
 
-void (*pm_power_off)(void);
-
 static void kill_off_processes(void)
 {
 	if (proc_mm)
diff --git a/arch/unicore32/kernel/process.c b/arch/unicore32/kernel/process.c
index b008e99..9490dd5 100644
--- a/arch/unicore32/kernel/process.c
+++ b/arch/unicore32/kernel/process.c
@@ -56,16 +56,9 @@ void machine_halt(void)
 	gpio_set_value(GPO_SOFT_OFF, 0);
 }
 
-/*
- * Function pointers to optional machine specific functions
- */
-void (*pm_power_off)(void) = NULL;
-EXPORT_SYMBOL(pm_power_off);
-
 void machine_power_off(void)
 {
-	if (pm_power_off)
-		pm_power_off();
+	do_kernel_power_off();
 	machine_halt();
 }
 
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 17962e6..5c09e28 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -30,12 +30,6 @@
 #include <asm/x86_init.h>
 #include <asm/efi.h>
 
-/*
- * Power off function, if any
- */
-void (*pm_power_off)(void);
-EXPORT_SYMBOL(pm_power_off);
-
 static const struct desc_ptr no_idt = {};
 
 /*
@@ -647,11 +641,12 @@ static void native_machine_halt(void)
 
 static void native_machine_power_off(void)
 {
-	if (pm_power_off) {
+	if (have_kernel_power_off()) {
 		if (!reboot_force)
 			machine_shutdown();
-		pm_power_off();
+		do_kernel_power_off();
 	}
+
 	/* A fallback in case there is no PM info available */
 	tboot_shutdown(TB_SHUTDOWN_HALT);
 }
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 1a3f044..c2c1d74 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1320,8 +1320,7 @@ static void xen_machine_halt(void)
 
 static void xen_machine_power_off(void)
 {
-	if (pm_power_off)
-		pm_power_off();
+	do_kernel_power_off();
 	xen_reboot(SHUTDOWN_poweroff);
 }
 
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
index 1c85323..c487296 100644
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -49,10 +49,6 @@ extern void ret_from_kernel_thread(void);
 
 struct task_struct *current_set[NR_CPUS] = {&init_task, };
 
-void (*pm_power_off)(void) = NULL;
-EXPORT_SYMBOL(pm_power_off);
-
-
 #if XTENSA_HAVE_COPROCESSORS
 
 void coprocessor_release_all(struct thread_info *ti)
diff --git a/drivers/parisc/power.c b/drivers/parisc/power.c
index ef31b77..f10cf92 100644
--- a/drivers/parisc/power.c
+++ b/drivers/parisc/power.c
@@ -95,8 +95,7 @@ static void process_shutdown(void)
 		/* send kill signal */
 		if (kill_cad_pid(SIGINT, 1)) {
 			/* just in case killing init process failed */
-			if (pm_power_off)
-				pm_power_off();
+			kernel_power_off();
 		}
 	}
 }
diff --git a/kernel/power/poweroff_handler.c b/kernel/power/poweroff_handler.c
index aeb4736..37f0b88 100644
--- a/kernel/power/poweroff_handler.c
+++ b/kernel/power/poweroff_handler.c
@@ -22,6 +22,12 @@
 #include <linux/types.h>
 
 /*
+ * If set, calling this function will power off the system immediately.
+ */
+void (*pm_power_off)(void);
+EXPORT_SYMBOL(pm_power_off);
+
+/*
  *	Notifier list for kernel code which wants to be called
  *	to power off the system.
  */
@@ -236,6 +242,8 @@ EXPORT_SYMBOL(devm_register_power_off_handler);
 void do_kernel_power_off(void)
 {
 	spin_lock(&power_off_handler_lock);
+	if (pm_power_off)
+		pm_power_off();
 	raw_notifier_call_chain(&power_off_handler_list, 0, NULL);
 	spin_unlock(&power_off_handler_lock);
 }
diff --git a/kernel/reboot.c b/kernel/reboot.c
index 5925f5a..0930851 100644
--- a/kernel/reboot.c
+++ b/kernel/reboot.c
@@ -306,9 +306,9 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
 		return ret;
 
 	/* Instead of trying to make the power_off code look like
-	 * halt when pm_power_off is not set do it the easy way.
+	 * halt when no poweroff handler exists do it the easy way.
 	 */
-	if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
+	if (cmd == LINUX_REBOOT_CMD_POWER_OFF && !have_kernel_power_off())
 		cmd = LINUX_REBOOT_CMD_HALT;
 
 	mutex_lock(&reboot_mutex);
-- 
1.9.1