diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/misc/ibmasm/heartbeat.c | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/drivers/misc/ibmasm/heartbeat.c b/drivers/misc/ibmasm/heartbeat.c new file mode 100644 index 000000000..90746378f --- /dev/null +++ b/drivers/misc/ibmasm/heartbeat.c @@ -0,0 +1,101 @@ + +/* + * 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); +} |