1 2 /* 3 * IBM ASM Service Processor Device Driver 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 18 * 19 * Copyright (C) IBM Corporation, 2004 20 * 21 * Author: Max Asb�ck <amax@us.ibm.com> 22 * 23 */ 24 25 #include <linux/notifier.h> 26 #include "ibmasm.h" 27 #include "dot_command.h" 28 29 static int suspend_heartbeats = 0; 30 31 /* 32 * Once the driver indicates to the service processor that it is running 33 * - see send_os_state() - the service processor sends periodic heartbeats 34 * to the driver. The driver must respond to the heartbeats or else the OS 35 * will be rebooted. 36 * In the case of a panic the interrupt handler continues to work and thus 37 * continues to respond to heartbeats, making the service processor believe 38 * the OS is still running and thus preventing a reboot. 39 * To prevent this from happening a callback is added the panic_notifier_list. 40 * Before responding to a heartbeat the driver checks if a panic has happened, 41 * if yes it suspends heartbeat, causing the service processor to reboot as 42 * expected. 43 */ 44 static int panic_happened(struct notifier_block *n, unsigned long val, void *v) 45 { 46 suspend_heartbeats = 1; 47 return 0; 48 } 49 50 static struct notifier_block panic_notifier = { panic_happened, NULL, 1 }; 51 52 void ibmasm_register_panic_notifier(void) 53 { 54 notifier_chain_register(&panic_notifier_list, &panic_notifier); 55 } 56 57 void ibmasm_unregister_panic_notifier(void) 58 { 59 notifier_chain_unregister(&panic_notifier_list, &panic_notifier); 60 } 61 62 63 int ibmasm_heartbeat_init(struct service_processor *sp) 64 { 65 sp->heartbeat = ibmasm_new_command(HEARTBEAT_BUFFER_SIZE); 66 if (sp->heartbeat == NULL) 67 return -ENOMEM; 68 69 return 0; 70 } 71 72 void ibmasm_heartbeat_exit(struct service_processor *sp) 73 { 74 command_put(sp->heartbeat); 75 } 76 77 void ibmasm_receive_heartbeat(struct service_processor *sp, void *message, size_t size) 78 { 79 struct command *cmd = sp->heartbeat; 80 struct dot_command_header *header = (struct dot_command_header *)cmd->buffer; 81 82 if (suspend_heartbeats) 83 return; 84 85 /* return the received dot command to sender */ 86 cmd->status = IBMASM_CMD_PENDING; 87 size = min(size, cmd->buffer_size); 88 memcpy(cmd->buffer, message, size); 89 header->type = sp_write; 90 ibmasm_exec_command(sp, cmd); 91 } 92