1/*
2 *     signal quiesce handler
3 *
4 *  Copyright IBM Corp. 1999, 2004
5 *  Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
6 *             Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
7 */
8
9#include <linux/module.h>
10#include <linux/types.h>
11#include <linux/cpumask.h>
12#include <linux/smp.h>
13#include <linux/init.h>
14#include <linux/reboot.h>
15#include <linux/atomic.h>
16#include <asm/ptrace.h>
17#include <asm/smp.h>
18
19#include "sclp.h"
20
21static void (*old_machine_restart)(char *);
22static void (*old_machine_halt)(void);
23static void (*old_machine_power_off)(void);
24
25/* Shutdown handler. Signal completion of shutdown by loading special PSW. */
26static void do_machine_quiesce(void)
27{
28	psw_t quiesce_psw;
29
30	smp_send_stop();
31	quiesce_psw.mask =
32		PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA | PSW_MASK_WAIT;
33	quiesce_psw.addr = 0xfff;
34	__load_psw(quiesce_psw);
35}
36
37/* Handler for quiesce event. Start shutdown procedure. */
38static void sclp_quiesce_handler(struct evbuf_header *evbuf)
39{
40	if (_machine_restart != (void *) do_machine_quiesce) {
41		old_machine_restart = _machine_restart;
42		old_machine_halt = _machine_halt;
43		old_machine_power_off = _machine_power_off;
44		_machine_restart = (void *) do_machine_quiesce;
45		_machine_halt = do_machine_quiesce;
46		_machine_power_off = do_machine_quiesce;
47	}
48	ctrl_alt_del();
49}
50
51/* Undo machine restart/halt/power_off modification on resume */
52static void sclp_quiesce_pm_event(struct sclp_register *reg,
53				  enum sclp_pm_event sclp_pm_event)
54{
55	switch (sclp_pm_event) {
56	case SCLP_PM_EVENT_RESTORE:
57		if (old_machine_restart) {
58			_machine_restart = old_machine_restart;
59			_machine_halt = old_machine_halt;
60			_machine_power_off = old_machine_power_off;
61			old_machine_restart = NULL;
62			old_machine_halt = NULL;
63			old_machine_power_off = NULL;
64		}
65		break;
66	case SCLP_PM_EVENT_FREEZE:
67	case SCLP_PM_EVENT_THAW:
68		break;
69	}
70}
71
72static struct sclp_register sclp_quiesce_event = {
73	.receive_mask = EVTYP_SIGQUIESCE_MASK,
74	.receiver_fn = sclp_quiesce_handler,
75	.pm_event_fn = sclp_quiesce_pm_event
76};
77
78/* Initialize quiesce driver. */
79static int __init sclp_quiesce_init(void)
80{
81	return sclp_register(&sclp_quiesce_event);
82}
83
84module_init(sclp_quiesce_init);
85