m68k: Switch to new sys-off handler API

Kernel now supports chained power-off handlers. Use
register_power_off_handler() that registers power-off handlers and
do_kernel_power_off() that invokes chained power-off handlers. Legacy
pm_power_off() will be removed once all drivers will be converted to
the new sys-off API.

Normally arch code should adopt only the do_kernel_power_off() at first,
but m68k is a special case because it uses pm_power_off() "inside out",
i.e. pm_power_off() invokes machine_power_off() [in fact it does nothing],
while it's machine_power_off() that should invoke the pm_power_off(), and
thus, we can't convert platforms to the new API separately. There are only
two platforms changed here, so it's not a big deal.

Acked-by: Geert Uytterhoeven <[e-mail]>
Reviewed-by: Michał Mirosław <[e-mail]>
Signed-off-by: Dmitry Osipenko <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>

arch/m68k/emu/natfeat.c

···
 #include <linux/string.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/reboot.h>
 #include <linux/io.h>
 #include <asm/machdep.h>
 #include <asm/natfeat.h>
···
 	pr_info("NatFeats found (%s, %lu.%lu)\n", buf, version >> 16,
 		version & 0xffff);
 
-	mach_power_off = nf_poweroff;
+	register_platform_power_off(nf_poweroff);
 }

arch/m68k/include/asm/machdep.h

···
 extern int (*mach_set_rtc_pll)(struct rtc_pll_info *);
 extern void (*mach_reset)( void );
 extern void (*mach_halt)( void );
-extern void (*mach_power_off)( void );
 extern unsigned long (*mach_hd_init) (unsigned long, unsigned long);
 extern void (*mach_hd_setup)(char *, int *);
 extern void (*mach_heartbeat) (int);

arch/m68k/kernel/process.c

···
 
 void machine_power_off(void)
 {
-	if (mach_power_off)
-		mach_power_off();
+	do_kernel_power_off();
 	for (;;);
 }
 
-void (*pm_power_off)(void) = machine_power_off;
+void (*pm_power_off)(void);
 EXPORT_SYMBOL(pm_power_off);
 
 void show_regs(struct pt_regs * regs)

arch/m68k/kernel/setup_mm.c

···
 EXPORT_SYMBOL(mach_set_rtc_pll);
 void (*mach_reset)( void );
 void (*mach_halt)( void );
-void (*mach_power_off)( void );
 #ifdef CONFIG_HEARTBEAT
 void (*mach_heartbeat) (int);
 EXPORT_SYMBOL(mach_heartbeat);

arch/m68k/kernel/setup_no.c

···
 /* machine dependent reboot functions */
 void (*mach_reset)(void);
 void (*mach_halt)(void);
-void (*mach_power_off)(void);
 
 #ifdef CONFIG_M68000
 #if defined(CONFIG_M68328)

arch/m68k/mac/config.c

···
 
 #include <linux/errno.h>
 #include <linux/module.h>
+#include <linux/reboot.h>
 #include <linux/types.h>
 #include <linux/mm.h>
 #include <linux/tty.h>
···
 	mach_hwclk = mac_hwclk;
 	mach_reset = mac_reset;
 	mach_halt = mac_poweroff;
-	mach_power_off = mac_poweroff;
 #if IS_ENABLED(CONFIG_INPUT_M68K_BEEP)
 	mach_beep = mac_mksound;
 #endif
···
 
 	if (macintosh_config->ident == MAC_MODEL_IICI)
 		mach_l2_flush = via_l2_flush;
+
+	register_platform_power_off(mac_poweroff);
 }