Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | * |
Al Viro | d36b691 | 2011-12-29 17:09:01 -0500 | [diff] [blame] | 21 | * Author: Max Asböck <amax@us.ibm.com> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | * |
| 23 | */ |
| 24 | |
| 25 | #include <linux/notifier.h> |
| 26 | #include "ibmasm.h" |
| 27 | #include "dot_command.h" |
Max Asbock | 8818760 | 2005-06-21 17:16:36 -0700 | [diff] [blame] | 28 | #include "lowlevel.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | { |
Alan Stern | e041c68 | 2006-03-27 01:16:30 -0800 | [diff] [blame] | 55 | atomic_notifier_chain_register(&panic_notifier_list, &panic_notifier); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | } |
| 57 | |
| 58 | void ibmasm_unregister_panic_notifier(void) |
| 59 | { |
Alan Stern | e041c68 | 2006-03-27 01:16:30 -0800 | [diff] [blame] | 60 | atomic_notifier_chain_unregister(&panic_notifier_list, |
| 61 | &panic_notifier); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | } |
| 63 | |
| 64 | |
| 65 | int ibmasm_heartbeat_init(struct service_processor *sp) |
| 66 | { |
Max Asbock | 8818760 | 2005-06-21 17:16:36 -0700 | [diff] [blame] | 67 | sp->heartbeat = ibmasm_new_command(sp, HEARTBEAT_BUFFER_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | if (sp->heartbeat == NULL) |
| 69 | return -ENOMEM; |
| 70 | |
| 71 | return 0; |
| 72 | } |
| 73 | |
| 74 | void ibmasm_heartbeat_exit(struct service_processor *sp) |
| 75 | { |
Max Asbock | 8818760 | 2005-06-21 17:16:36 -0700 | [diff] [blame] | 76 | char tsbuf[32]; |
| 77 | |
Harvey Harrison | 6e57419 | 2008-04-29 00:59:20 -0700 | [diff] [blame] | 78 | dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); |
Max Asbock | 8818760 | 2005-06-21 17:16:36 -0700 | [diff] [blame] | 79 | ibmasm_wait_for_response(sp->heartbeat, IBMASM_CMD_TIMEOUT_NORMAL); |
Harvey Harrison | 6e57419 | 2008-04-29 00:59:20 -0700 | [diff] [blame] | 80 | dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); |
Max Asbock | 8818760 | 2005-06-21 17:16:36 -0700 | [diff] [blame] | 81 | suspend_heartbeats = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | command_put(sp->heartbeat); |
| 83 | } |
| 84 | |
| 85 | void ibmasm_receive_heartbeat(struct service_processor *sp, void *message, size_t size) |
| 86 | { |
| 87 | struct command *cmd = sp->heartbeat; |
| 88 | struct dot_command_header *header = (struct dot_command_header *)cmd->buffer; |
Max Asbock | 8818760 | 2005-06-21 17:16:36 -0700 | [diff] [blame] | 89 | char tsbuf[32]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | |
Harvey Harrison | 6e57419 | 2008-04-29 00:59:20 -0700 | [diff] [blame] | 91 | dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | if (suspend_heartbeats) |
| 93 | return; |
| 94 | |
| 95 | /* return the received dot command to sender */ |
| 96 | cmd->status = IBMASM_CMD_PENDING; |
| 97 | size = min(size, cmd->buffer_size); |
Max Asbock | 8818760 | 2005-06-21 17:16:36 -0700 | [diff] [blame] | 98 | memcpy_fromio(cmd->buffer, message, size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | header->type = sp_write; |
| 100 | ibmasm_exec_command(sp, cmd); |
| 101 | } |