/*
* 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"
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)
{
notifier_chain_register(&panic_notifier_list, &panic_notifier);
}
void ibmasm_unregister_panic_notifier(void)
{
notifier_chain_unregister(&panic_notifier_list, &panic_notifier);
}
int ibmasm_heartbeat_init(struct service_processor *sp)
{
sp->heartbeat = ibmasm_new_command(HEARTBEAT_BUFFER_SIZE);
if (sp->heartbeat == NULL)
return -ENOMEM;
return 0;
}
void ibmasm_heartbeat_exit(struct service_processor *sp)
{
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;
if (suspend_heartbeats)
return;
/* return the received dot command to sender */
cmd->status = IBMASM_CMD_PENDING;
size = min(size, cmd->buffer_size);
memcpy(cmd->buffer, message, size);
header->type = sp_write;
ibmasm_exec_command(sp, cmd);
}
