1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * signal quiesce handler 4 * 5 * 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/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 device_initcall(sclp_quiesce_init); 84