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 23 static void (*old_machine_restart)(char *); 24 static void (*old_machine_halt)(void); 25 static void (*old_machine_power_off)(void); 26 27 /* Shutdown handler. Signal completion of shutdown by loading special PSW. */ 28 static 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. */ 40 static 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 */ 54 static 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 74 static 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. */ 81 static int __init sclp_quiesce_init(void) 82 { 83 return sclp_register(&sclp_quiesce_event); 84 } 85 86 module_init(sclp_quiesce_init); 87