]>
Commit | Line | Data |
---|---|---|
1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | |
3 | /* | |
4 | * IBM ASM Service Processor Device Driver | |
5 | * | |
1da177e4 LT |
6 | * Copyright (C) IBM Corporation, 2004 |
7 | * | |
d36b6910 | 8 | * Author: Max Asböck <amax@us.ibm.com> |
1da177e4 LT |
9 | */ |
10 | ||
11 | #include <linux/notifier.h> | |
12 | #include "ibmasm.h" | |
13 | #include "dot_command.h" | |
88187605 | 14 | #include "lowlevel.h" |
1da177e4 LT |
15 | |
16 | static int suspend_heartbeats = 0; | |
17 | ||
18 | /* | |
19 | * Once the driver indicates to the service processor that it is running | |
20 | * - see send_os_state() - the service processor sends periodic heartbeats | |
21 | * to the driver. The driver must respond to the heartbeats or else the OS | |
22 | * will be rebooted. | |
23 | * In the case of a panic the interrupt handler continues to work and thus | |
24 | * continues to respond to heartbeats, making the service processor believe | |
25 | * the OS is still running and thus preventing a reboot. | |
26 | * To prevent this from happening a callback is added the panic_notifier_list. | |
27 | * Before responding to a heartbeat the driver checks if a panic has happened, | |
28 | * if yes it suspends heartbeat, causing the service processor to reboot as | |
29 | * expected. | |
30 | */ | |
31 | static int panic_happened(struct notifier_block *n, unsigned long val, void *v) | |
32 | { | |
33 | suspend_heartbeats = 1; | |
34 | return 0; | |
35 | } | |
36 | ||
37 | static struct notifier_block panic_notifier = { panic_happened, NULL, 1 }; | |
38 | ||
39 | void ibmasm_register_panic_notifier(void) | |
40 | { | |
e041c683 | 41 | atomic_notifier_chain_register(&panic_notifier_list, &panic_notifier); |
1da177e4 LT |
42 | } |
43 | ||
44 | void ibmasm_unregister_panic_notifier(void) | |
45 | { | |
e041c683 AS |
46 | atomic_notifier_chain_unregister(&panic_notifier_list, |
47 | &panic_notifier); | |
1da177e4 LT |
48 | } |
49 | ||
50 | ||
51 | int ibmasm_heartbeat_init(struct service_processor *sp) | |
52 | { | |
88187605 | 53 | sp->heartbeat = ibmasm_new_command(sp, HEARTBEAT_BUFFER_SIZE); |
1da177e4 LT |
54 | if (sp->heartbeat == NULL) |
55 | return -ENOMEM; | |
56 | ||
57 | return 0; | |
58 | } | |
59 | ||
60 | void ibmasm_heartbeat_exit(struct service_processor *sp) | |
61 | { | |
88187605 MA |
62 | char tsbuf[32]; |
63 | ||
6e574195 | 64 | dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); |
88187605 | 65 | ibmasm_wait_for_response(sp->heartbeat, IBMASM_CMD_TIMEOUT_NORMAL); |
6e574195 | 66 | dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); |
88187605 | 67 | suspend_heartbeats = 1; |
1da177e4 LT |
68 | command_put(sp->heartbeat); |
69 | } | |
70 | ||
71 | void ibmasm_receive_heartbeat(struct service_processor *sp, void *message, size_t size) | |
72 | { | |
73 | struct command *cmd = sp->heartbeat; | |
74 | struct dot_command_header *header = (struct dot_command_header *)cmd->buffer; | |
88187605 | 75 | char tsbuf[32]; |
1da177e4 | 76 | |
6e574195 | 77 | dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); |
1da177e4 LT |
78 | if (suspend_heartbeats) |
79 | return; | |
80 | ||
81 | /* return the received dot command to sender */ | |
82 | cmd->status = IBMASM_CMD_PENDING; | |
83 | size = min(size, cmd->buffer_size); | |
88187605 | 84 | memcpy_fromio(cmd->buffer, message, size); |
1da177e4 LT |
85 | header->type = sp_write; |
86 | ibmasm_exec_command(sp, cmd); | |
87 | } |