s390: remove broken hibernate / power management support

Hibernation is known to be broken for many years on s390. Given that
there aren't any real use cases, remove the code instead of spending
time to fix and maintain it.

Without hibernate support it doesn't make too much sense to keep power
management support; therefore remove it completely.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

arch/s390/Kconfig

@@ -102,7 +102,6 @@ config S390
 	select ARCH_INLINE_WRITE_UNLOCK_IRQ
 	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
 	select ARCH_KEEP_MEMBLOCK
-	select ARCH_SAVE_PAGE_KEYS if HIBERNATION
 	select ARCH_STACKWALK
 	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_SUPPORTS_NUMA_BALANCING
@@ -810,15 +809,6 @@ config SECCOMP
 
 	  If unsure, say Y.
 
-menu "Power Management"
-
-config ARCH_HIBERNATION_POSSIBLE
-	def_bool y
-
-source "kernel/power/Kconfig"
-
-endmenu
-
 config CCW
 	def_bool y
 

arch/s390/kernel/Makefile

@@ -54,7 +54,6 @@ CFLAGS_REMOVE_nospec-branch.o	+= $(CC_FLAGS_EXPOLINE)
 
 obj-$(CONFIG_MODULES)		+= module.o
 obj-$(CONFIG_SCHED_TOPOLOGY)	+= topology.o
-obj-$(CONFIG_HIBERNATION)	+= suspend.o swsusp.o
 obj-$(CONFIG_AUDIT)		+= audit.o
 compat-obj-$(CONFIG_AUDIT)	+= compat_audit.o
 obj-$(CONFIG_COMPAT)		+= compat_linux.o compat_signal.o

arch/s390/kernel/machine_kexec.c

@@ -14,7 +14,6 @@
 #include <linux/reboot.h>
 #include <linux/ftrace.h>
 #include <linux/debug_locks.h>
-#include <linux/suspend.h>
 #include <asm/cio.h>
 #include <asm/setup.h>
 #include <asm/pgtable.h>
@@ -38,36 +37,6 @@ extern const unsigned long long relocate_kernel_len;
 
 #ifdef CONFIG_CRASH_DUMP
 
-/*
- * PM notifier callback for kdump
- */
-static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
-			       void *ptr)
-{
-	switch (action) {
-	case PM_SUSPEND_PREPARE:
-	case PM_HIBERNATION_PREPARE:
-		if (kexec_crash_image)
-			arch_kexec_unprotect_crashkres();
-		break;
-	case PM_POST_SUSPEND:
-	case PM_POST_HIBERNATION:
-		if (kexec_crash_image)
-			arch_kexec_protect_crashkres();
-		break;
-	default:
-		return NOTIFY_DONE;
-	}
-	return NOTIFY_OK;
-}
-
-static int __init machine_kdump_pm_init(void)
-{
-	pm_notifier(machine_kdump_pm_cb, 0);
-	return 0;
-}
-arch_initcall(machine_kdump_pm_init);
-
 /*
  * Reset the system, copy boot CPU registers to absolute zero,
  * and jump to the kdump image