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Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git...
[karo-tx-linux.git] / drivers / s390 / char / sclp_quiesce.c
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
21 static void (*old_machine_restart)(char *);
22 static void (*old_machine_halt)(void);
23 static void (*old_machine_power_off)(void);
24
25 /* Shutdown handler. Signal completion of shutdown by loading special PSW. */
26 static 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. */
38 static 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 */
52 static 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
72 static 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. */
79 static int __init sclp_quiesce_init(void)
80 {
81         return sclp_register(&sclp_quiesce_event);
82 }
83
84 module_init(sclp_quiesce_init);