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 #include "lowlevel.h" 29 30 static int suspend_heartbeats = 0; 31 32 /* 33 * Once the driver indicates to the service processor that it is running 34 * - see send_os_state() - the service processor sends periodic heartbeats 35 * to the driver. The driver must respond to the heartbeats or else the OS 36 * will be rebooted. 37 * In the case of a panic the interrupt handler continues to work and thus 38 * continues to respond to heartbeats, making the service processor believe 39 * the OS is still running and thus preventing a reboot. 40 * To prevent this from happening a callback is added the panic_notifier_list. 41 * Before responding to a heartbeat the driver checks if a panic has happened, 42 * if yes it suspends heartbeat, causing the service processor to reboot as 43 * expected. 44 */ 45 static int panic_happened(struct notifier_block *n, unsigned long val, void *v) 46 { 47 suspend_heartbeats = 1; 48 return 0; 49 } 50 51 static struct notifier_block panic_notifier = { panic_happened, NULL, 1 }; 52 53 void ibmasm_register_panic_notifier(void) 54 { 55 notifier_chain_register(&panic_notifier_list, &panic_notifier); 56 } 57 58 void ibmasm_unregister_panic_notifier(void) 59 { 60 notifier_chain_unregister(&panic_notifier_list, &panic_notifier); 61 } 62 63 64 int ibmasm_heartbeat_init(struct service_processor *sp) 65 { 66 sp->heartbeat = ibmasm_new_command(sp, HEARTBEAT_BUFFER_SIZE); 67 if (sp->heartbeat == NULL) 68 return -ENOMEM; 69 70 return 0; 71 } 72 73 void ibmasm_heartbeat_exit(struct service_processor *sp) 74 { 75 char tsbuf[32]; 76 77 dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf)); 78 ibmasm_wait_for_response(sp->heartbeat, IBMASM_CMD_TIMEOUT_NORMAL); 79 dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf)); 80 suspend_heartbeats = 1; 81 command_put(sp->heartbeat); 82 } 83 84 void ibmasm_receive_heartbeat(struct service_processor *sp, void *message, size_t size) 85 { 86 struct command *cmd = sp->heartbeat; 87 struct dot_command_header *header = (struct dot_command_header *)cmd->buffer; 88 char tsbuf[32]; 89 90 dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf)); 91 if (suspend_heartbeats) 92 return; 93 94 /* return the received dot command to sender */ 95 cmd->status = IBMASM_CMD_PENDING; 96 size = min(size, cmd->buffer_size); 97 memcpy_fromio(cmd->buffer, message, size); 98 header->type = sp_write; 99 ibmasm_exec_command(sp, cmd); 100 } 101