xref: /OK3568_Linux_fs/kernel/drivers/s390/char/sclp_quiesce.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  *     signal quiesce handler
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  *  Copyright IBM Corp. 1999, 2004
6*4882a593Smuzhiyun  *  Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
7*4882a593Smuzhiyun  *             Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
8*4882a593Smuzhiyun  */
9*4882a593Smuzhiyun 
10*4882a593Smuzhiyun #include <linux/types.h>
11*4882a593Smuzhiyun #include <linux/cpumask.h>
12*4882a593Smuzhiyun #include <linux/smp.h>
13*4882a593Smuzhiyun #include <linux/init.h>
14*4882a593Smuzhiyun #include <linux/reboot.h>
15*4882a593Smuzhiyun #include <linux/atomic.h>
16*4882a593Smuzhiyun #include <asm/ptrace.h>
17*4882a593Smuzhiyun #include <asm/smp.h>
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun #include "sclp.h"
20*4882a593Smuzhiyun 
21*4882a593Smuzhiyun static void (*old_machine_restart)(char *);
22*4882a593Smuzhiyun static void (*old_machine_halt)(void);
23*4882a593Smuzhiyun static void (*old_machine_power_off)(void);
24*4882a593Smuzhiyun 
25*4882a593Smuzhiyun /* Shutdown handler. Signal completion of shutdown by loading special PSW. */
do_machine_quiesce(void)26*4882a593Smuzhiyun static void do_machine_quiesce(void)
27*4882a593Smuzhiyun {
28*4882a593Smuzhiyun 	psw_t quiesce_psw;
29*4882a593Smuzhiyun 
30*4882a593Smuzhiyun 	smp_send_stop();
31*4882a593Smuzhiyun 	quiesce_psw.mask =
32*4882a593Smuzhiyun 		PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA | PSW_MASK_WAIT;
33*4882a593Smuzhiyun 	quiesce_psw.addr = 0xfff;
34*4882a593Smuzhiyun 	__load_psw(quiesce_psw);
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun 
37*4882a593Smuzhiyun /* Handler for quiesce event. Start shutdown procedure. */
sclp_quiesce_handler(struct evbuf_header * evbuf)38*4882a593Smuzhiyun static void sclp_quiesce_handler(struct evbuf_header *evbuf)
39*4882a593Smuzhiyun {
40*4882a593Smuzhiyun 	if (_machine_restart != (void *) do_machine_quiesce) {
41*4882a593Smuzhiyun 		old_machine_restart = _machine_restart;
42*4882a593Smuzhiyun 		old_machine_halt = _machine_halt;
43*4882a593Smuzhiyun 		old_machine_power_off = _machine_power_off;
44*4882a593Smuzhiyun 		_machine_restart = (void *) do_machine_quiesce;
45*4882a593Smuzhiyun 		_machine_halt = do_machine_quiesce;
46*4882a593Smuzhiyun 		_machine_power_off = do_machine_quiesce;
47*4882a593Smuzhiyun 	}
48*4882a593Smuzhiyun 	ctrl_alt_del();
49*4882a593Smuzhiyun }
50*4882a593Smuzhiyun 
51*4882a593Smuzhiyun /* Undo machine restart/halt/power_off modification on resume */
sclp_quiesce_pm_event(struct sclp_register * reg,enum sclp_pm_event sclp_pm_event)52*4882a593Smuzhiyun static void sclp_quiesce_pm_event(struct sclp_register *reg,
53*4882a593Smuzhiyun 				  enum sclp_pm_event sclp_pm_event)
54*4882a593Smuzhiyun {
55*4882a593Smuzhiyun 	switch (sclp_pm_event) {
56*4882a593Smuzhiyun 	case SCLP_PM_EVENT_RESTORE:
57*4882a593Smuzhiyun 		if (old_machine_restart) {
58*4882a593Smuzhiyun 			_machine_restart = old_machine_restart;
59*4882a593Smuzhiyun 			_machine_halt = old_machine_halt;
60*4882a593Smuzhiyun 			_machine_power_off = old_machine_power_off;
61*4882a593Smuzhiyun 			old_machine_restart = NULL;
62*4882a593Smuzhiyun 			old_machine_halt = NULL;
63*4882a593Smuzhiyun 			old_machine_power_off = NULL;
64*4882a593Smuzhiyun 		}
65*4882a593Smuzhiyun 		break;
66*4882a593Smuzhiyun 	case SCLP_PM_EVENT_FREEZE:
67*4882a593Smuzhiyun 	case SCLP_PM_EVENT_THAW:
68*4882a593Smuzhiyun 		break;
69*4882a593Smuzhiyun 	}
70*4882a593Smuzhiyun }
71*4882a593Smuzhiyun 
72*4882a593Smuzhiyun static struct sclp_register sclp_quiesce_event = {
73*4882a593Smuzhiyun 	.receive_mask = EVTYP_SIGQUIESCE_MASK,
74*4882a593Smuzhiyun 	.receiver_fn = sclp_quiesce_handler,
75*4882a593Smuzhiyun 	.pm_event_fn = sclp_quiesce_pm_event
76*4882a593Smuzhiyun };
77*4882a593Smuzhiyun 
78*4882a593Smuzhiyun /* Initialize quiesce driver. */
sclp_quiesce_init(void)79*4882a593Smuzhiyun static int __init sclp_quiesce_init(void)
80*4882a593Smuzhiyun {
81*4882a593Smuzhiyun 	return sclp_register(&sclp_quiesce_event);
82*4882a593Smuzhiyun }
83*4882a593Smuzhiyun device_initcall(sclp_quiesce_init);
84