11da177e4SLinus Torvalds 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * IBM ASM Service Processor Device Driver 41da177e4SLinus Torvalds * 51da177e4SLinus Torvalds * This program is free software; you can redistribute it and/or modify 61da177e4SLinus Torvalds * it under the terms of the GNU General Public License as published by 71da177e4SLinus Torvalds * the Free Software Foundation; either version 2 of the License, or 81da177e4SLinus Torvalds * (at your option) any later version. 91da177e4SLinus Torvalds * 101da177e4SLinus Torvalds * This program is distributed in the hope that it will be useful, 111da177e4SLinus Torvalds * but WITHOUT ANY WARRANTY; without even the implied warranty of 121da177e4SLinus Torvalds * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 131da177e4SLinus Torvalds * GNU General Public License for more details. 141da177e4SLinus Torvalds * 151da177e4SLinus Torvalds * You should have received a copy of the GNU General Public License 161da177e4SLinus Torvalds * along with this program; if not, write to the Free Software 171da177e4SLinus Torvalds * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 181da177e4SLinus Torvalds * 191da177e4SLinus Torvalds * Copyright (C) IBM Corporation, 2004 201da177e4SLinus Torvalds * 211da177e4SLinus Torvalds * Author: Max Asb�ck <amax@us.ibm.com> 221da177e4SLinus Torvalds * 231da177e4SLinus Torvalds */ 241da177e4SLinus Torvalds 251da177e4SLinus Torvalds #include <linux/notifier.h> 261da177e4SLinus Torvalds #include "ibmasm.h" 271da177e4SLinus Torvalds #include "dot_command.h" 281da177e4SLinus Torvalds 291da177e4SLinus Torvalds static int suspend_heartbeats = 0; 301da177e4SLinus Torvalds 311da177e4SLinus Torvalds /* 321da177e4SLinus Torvalds * Once the driver indicates to the service processor that it is running 331da177e4SLinus Torvalds * - see send_os_state() - the service processor sends periodic heartbeats 341da177e4SLinus Torvalds * to the driver. The driver must respond to the heartbeats or else the OS 351da177e4SLinus Torvalds * will be rebooted. 361da177e4SLinus Torvalds * In the case of a panic the interrupt handler continues to work and thus 371da177e4SLinus Torvalds * continues to respond to heartbeats, making the service processor believe 381da177e4SLinus Torvalds * the OS is still running and thus preventing a reboot. 391da177e4SLinus Torvalds * To prevent this from happening a callback is added the panic_notifier_list. 401da177e4SLinus Torvalds * Before responding to a heartbeat the driver checks if a panic has happened, 411da177e4SLinus Torvalds * if yes it suspends heartbeat, causing the service processor to reboot as 421da177e4SLinus Torvalds * expected. 431da177e4SLinus Torvalds */ 441da177e4SLinus Torvalds static int panic_happened(struct notifier_block *n, unsigned long val, void *v) 451da177e4SLinus Torvalds { 461da177e4SLinus Torvalds suspend_heartbeats = 1; 471da177e4SLinus Torvalds return 0; 481da177e4SLinus Torvalds } 491da177e4SLinus Torvalds 501da177e4SLinus Torvalds static struct notifier_block panic_notifier = { panic_happened, NULL, 1 }; 511da177e4SLinus Torvalds 521da177e4SLinus Torvalds void ibmasm_register_panic_notifier(void) 531da177e4SLinus Torvalds { 541da177e4SLinus Torvalds notifier_chain_register(&panic_notifier_list, &panic_notifier); 551da177e4SLinus Torvalds } 561da177e4SLinus Torvalds 571da177e4SLinus Torvalds void ibmasm_unregister_panic_notifier(void) 581da177e4SLinus Torvalds { 591da177e4SLinus Torvalds notifier_chain_unregister(&panic_notifier_list, &panic_notifier); 601da177e4SLinus Torvalds } 611da177e4SLinus Torvalds 621da177e4SLinus Torvalds 631da177e4SLinus Torvalds int ibmasm_heartbeat_init(struct service_processor *sp) 641da177e4SLinus Torvalds { 651da177e4SLinus Torvalds sp->heartbeat = ibmasm_new_command(HEARTBEAT_BUFFER_SIZE); 661da177e4SLinus Torvalds if (sp->heartbeat == NULL) 671da177e4SLinus Torvalds return -ENOMEM; 681da177e4SLinus Torvalds 691da177e4SLinus Torvalds return 0; 701da177e4SLinus Torvalds } 711da177e4SLinus Torvalds 721da177e4SLinus Torvalds void ibmasm_heartbeat_exit(struct service_processor *sp) 731da177e4SLinus Torvalds { 741da177e4SLinus Torvalds command_put(sp->heartbeat); 751da177e4SLinus Torvalds } 761da177e4SLinus Torvalds 771da177e4SLinus Torvalds void ibmasm_receive_heartbeat(struct service_processor *sp, void *message, size_t size) 781da177e4SLinus Torvalds { 791da177e4SLinus Torvalds struct command *cmd = sp->heartbeat; 801da177e4SLinus Torvalds struct dot_command_header *header = (struct dot_command_header *)cmd->buffer; 811da177e4SLinus Torvalds 821da177e4SLinus Torvalds if (suspend_heartbeats) 831da177e4SLinus Torvalds return; 841da177e4SLinus Torvalds 851da177e4SLinus Torvalds /* return the received dot command to sender */ 861da177e4SLinus Torvalds cmd->status = IBMASM_CMD_PENDING; 871da177e4SLinus Torvalds size = min(size, cmd->buffer_size); 881da177e4SLinus Torvalds memcpy(cmd->buffer, message, size); 891da177e4SLinus Torvalds header->type = sp_write; 901da177e4SLinus Torvalds ibmasm_exec_command(sp, cmd); 911da177e4SLinus Torvalds } 92