tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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/types.h>
10#include <linux/cpumask.h>
11#include <linux/smp.h>
12#include <linux/init.h>
13#include <linux/reboot.h>
14#include <linux/atomic.h>
15#include <asm/ptrace.h>
16#include <asm/smp.h>
17
18#include "sclp.h"
19
20static void (*old_machine_restart)(char *);
21static void (*old_machine_halt)(void);
22static void (*old_machine_power_off)(void);
23
24/* Shutdown handler. Signal completion of shutdown by loading special PSW. */
25static void do_machine_quiesce(void)
26{
27 psw_t quiesce_psw;
28
29 smp_send_stop();
30 quiesce_psw.mask =
31 PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA | PSW_MASK_WAIT;
32 quiesce_psw.addr = 0xfff;
33 __load_psw(quiesce_psw);
34}
35
36/* Handler for quiesce event. Start shutdown procedure. */
37static void sclp_quiesce_handler(struct evbuf_header *evbuf)
38{
39 if (_machine_restart != (void *) do_machine_quiesce) {
40 old_machine_restart = _machine_restart;
41 old_machine_halt = _machine_halt;
42 old_machine_power_off = _machine_power_off;
43 _machine_restart = (void *) do_machine_quiesce;
44 _machine_halt = do_machine_quiesce;
45 _machine_power_off = do_machine_quiesce;
46 }
47 ctrl_alt_del();
48}
49
50/* Undo machine restart/halt/power_off modification on resume */
51static void sclp_quiesce_pm_event(struct sclp_register *reg,
52 enum sclp_pm_event sclp_pm_event)
53{
54 switch (sclp_pm_event) {
55 case SCLP_PM_EVENT_RESTORE:
56 if (old_machine_restart) {
57 _machine_restart = old_machine_restart;
58 _machine_halt = old_machine_halt;
59 _machine_power_off = old_machine_power_off;
60 old_machine_restart = NULL;
61 old_machine_halt = NULL;
62 old_machine_power_off = NULL;
63 }
64 break;
65 case SCLP_PM_EVENT_FREEZE:
66 case SCLP_PM_EVENT_THAW:
67 break;
68 }
69}
70
71static struct sclp_register sclp_quiesce_event = {
72 .receive_mask = EVTYP_SIGQUIESCE_MASK,
73 .receiver_fn = sclp_quiesce_handler,
74 .pm_event_fn = sclp_quiesce_pm_event
75};
76
77/* Initialize quiesce driver. */
78static int __init sclp_quiesce_init(void)
79{
80 return sclp_register(&sclp_quiesce_event);
81}
82device_initcall(sclp_quiesce_init);