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1da177e4 LT |
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 | * | |
d36b6910 | 21 | * Author: Max Asböck <amax@us.ibm.com> |
1da177e4 LT |
22 | * |
23 | */ | |
24 | ||
25 | #include <linux/notifier.h> | |
26 | #include "ibmasm.h" | |
27 | #include "dot_command.h" | |
88187605 | 28 | #include "lowlevel.h" |
1da177e4 LT |
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 | { | |
e041c683 | 55 | atomic_notifier_chain_register(&panic_notifier_list, &panic_notifier); |
1da177e4 LT |
56 | } |
57 | ||
58 | void ibmasm_unregister_panic_notifier(void) | |
59 | { | |
e041c683 AS |
60 | atomic_notifier_chain_unregister(&panic_notifier_list, |
61 | &panic_notifier); | |
1da177e4 LT |
62 | } |
63 | ||
64 | ||
65 | int ibmasm_heartbeat_init(struct service_processor *sp) | |
66 | { | |
88187605 | 67 | sp->heartbeat = ibmasm_new_command(sp, HEARTBEAT_BUFFER_SIZE); |
1da177e4 LT |
68 | if (sp->heartbeat == NULL) |
69 | return -ENOMEM; | |
70 | ||
71 | return 0; | |
72 | } | |
73 | ||
74 | void ibmasm_heartbeat_exit(struct service_processor *sp) | |
75 | { | |
88187605 MA |
76 | char tsbuf[32]; |
77 | ||
6e574195 | 78 | dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); |
88187605 | 79 | ibmasm_wait_for_response(sp->heartbeat, IBMASM_CMD_TIMEOUT_NORMAL); |
6e574195 | 80 | dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); |
88187605 | 81 | suspend_heartbeats = 1; |
1da177e4 LT |
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; | |
88187605 | 89 | char tsbuf[32]; |
1da177e4 | 90 | |
6e574195 | 91 | dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); |
1da177e4 LT |
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); | |
88187605 | 98 | memcpy_fromio(cmd->buffer, message, size); |
1da177e4 LT |
99 | header->type = sp_write; |
100 | ibmasm_exec_command(sp, cmd); | |
101 | } |