/* * IBM ASM Service Processor Device Driver * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * Copyright (C) IBM Corporation, 2004 * * Author: Max Asböck <amax@us.ibm.com> * */ #include <linux/notifier.h> #include "ibmasm.h" #include "dot_command.h" #include "lowlevel.h" static int suspend_heartbeats = 0; /* * Once the driver indicates to the service processor that it is running * - see send_os_state() - the service processor sends periodic heartbeats * to the driver. The driver must respond to the heartbeats or else the OS * will be rebooted. * In the case of a panic the interrupt handler continues to work and thus * continues to respond to heartbeats, making the service processor believe * the OS is still running and thus preventing a reboot. * To prevent this from happening a callback is added the panic_notifier_list. * Before responding to a heartbeat the driver checks if a panic has happened, * if yes it suspends heartbeat, causing the service processor to reboot as * expected. */ static int panic_happened(struct notifier_block *n, unsigned long val, void *v) { suspend_heartbeats = 1; return 0; } static struct notifier_block panic_notifier = { panic_happened, NULL, 1 }; void ibmasm_register_panic_notifier(void) { atomic_notifier_chain_register(&panic_notifier_list, &panic_notifier); } void ibmasm_unregister_panic_notifier(void) { atomic_notifier_chain_unregister(&panic_notifier_list, &panic_notifier); } int ibmasm_heartbeat_init(struct service_processor *sp) { sp->heartbeat = ibmasm_new_command(sp, HEARTBEAT_BUFFER_SIZE); if (sp->heartbeat == NULL) return -ENOMEM; return 0; } void ibmasm_heartbeat_exit(struct service_processor *sp) { char tsbuf[32]; dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); ibmasm_wait_for_response(sp->heartbeat, IBMASM_CMD_TIMEOUT_NORMAL); dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); suspend_heartbeats = 1; command_put(sp->heartbeat); } void ibmasm_receive_heartbeat(struct service_processor *sp, void *message, size_t size) { struct command *cmd = sp->heartbeat; struct dot_command_header *header = (struct dot_command_header *)cmd->buffer; char tsbuf[32]; dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); if (suspend_heartbeats) return; /* return the received dot command to sender */ cmd->status = IBMASM_CMD_PENDING; size = min(size, cmd->buffer_size); memcpy_fromio(cmd->buffer, message, size); header->type = sp_write; ibmasm_exec_command(sp, cmd); }