tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * drivers/s390/char/sclp_quiesce.c
3 * signal quiesce handler
4 *
5 * (C) Copyright IBM Corp. 1999,2004
6 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
7 * Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
8 */
9
10#include <linux/module.h>
11#include <linux/types.h>
12#include <linux/cpumask.h>
13#include <linux/smp.h>
14#include <linux/init.h>
15#include <linux/reboot.h>
16#include <linux/atomic.h>
17#include <asm/ptrace.h>
18#include <asm/sigp.h>
19#include <asm/smp.h>
20
21#include "sclp.h"
22
23static void (*old_machine_restart)(char *);
24static void (*old_machine_halt)(void);
25static void (*old_machine_power_off)(void);
26
27/* Shutdown handler. Signal completion of shutdown by loading special PSW. */
28static void do_machine_quiesce(void)
29{
30 psw_t quiesce_psw;
31
32 smp_send_stop();
33 quiesce_psw.mask =
34 PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA | PSW_MASK_WAIT;
35 quiesce_psw.addr = 0xfff;
36 __load_psw(quiesce_psw);
37}
38
39/* Handler for quiesce event. Start shutdown procedure. */
40static void sclp_quiesce_handler(struct evbuf_header *evbuf)
41{
42 if (_machine_restart != (void *) do_machine_quiesce) {
43 old_machine_restart = _machine_restart;
44 old_machine_halt = _machine_halt;
45 old_machine_power_off = _machine_power_off;
46 _machine_restart = (void *) do_machine_quiesce;
47 _machine_halt = do_machine_quiesce;
48 _machine_power_off = do_machine_quiesce;
49 }
50 ctrl_alt_del();
51}
52
53/* Undo machine restart/halt/power_off modification on resume */
54static void sclp_quiesce_pm_event(struct sclp_register *reg,
55 enum sclp_pm_event sclp_pm_event)
56{
57 switch (sclp_pm_event) {
58 case SCLP_PM_EVENT_RESTORE:
59 if (old_machine_restart) {
60 _machine_restart = old_machine_restart;
61 _machine_halt = old_machine_halt;
62 _machine_power_off = old_machine_power_off;
63 old_machine_restart = NULL;
64 old_machine_halt = NULL;
65 old_machine_power_off = NULL;
66 }
67 break;
68 case SCLP_PM_EVENT_FREEZE:
69 case SCLP_PM_EVENT_THAW:
70 break;
71 }
72}
73
74static struct sclp_register sclp_quiesce_event = {
75 .receive_mask = EVTYP_SIGQUIESCE_MASK,
76 .receiver_fn = sclp_quiesce_handler,
77 .pm_event_fn = sclp_quiesce_pm_event
78};
79
80/* Initialize quiesce driver. */
81static int __init sclp_quiesce_init(void)
82{
83 return sclp_register(&sclp_quiesce_event);
84}
85
86module_init(sclp_quiesce_init);