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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/misc/ibmasm/heartbeat.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/misc/ibmasm/heartbeat.c')
-rw-r--r--drivers/misc/ibmasm/heartbeat.c91
1 files changed, 91 insertions, 0 deletions
diff --git a/drivers/misc/ibmasm/heartbeat.c b/drivers/misc/ibmasm/heartbeat.c
new file mode 100644
index 000000000000..ce09309174d6
--- /dev/null
+++ b/drivers/misc/ibmasm/heartbeat.c
@@ -0,0 +1,91 @@
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 *
21 * Author: Max Asböck <amax@us.ibm.com>
22 *
23 */
24
25#include <linux/notifier.h>
26#include "ibmasm.h"
27#include "dot_command.h"
28
29static int suspend_heartbeats = 0;
30
31/*
32 * Once the driver indicates to the service processor that it is running
33 * - see send_os_state() - the service processor sends periodic heartbeats
34 * to the driver. The driver must respond to the heartbeats or else the OS
35 * will be rebooted.
36 * In the case of a panic the interrupt handler continues to work and thus
37 * continues to respond to heartbeats, making the service processor believe
38 * the OS is still running and thus preventing a reboot.
39 * To prevent this from happening a callback is added the panic_notifier_list.
40 * Before responding to a heartbeat the driver checks if a panic has happened,
41 * if yes it suspends heartbeat, causing the service processor to reboot as
42 * expected.
43 */
44static int panic_happened(struct notifier_block *n, unsigned long val, void *v)
45{
46 suspend_heartbeats = 1;
47 return 0;
48}
49
50static struct notifier_block panic_notifier = { panic_happened, NULL, 1 };
51
52void ibmasm_register_panic_notifier(void)
53{
54 notifier_chain_register(&panic_notifier_list, &panic_notifier);
55}
56
57void ibmasm_unregister_panic_notifier(void)
58{
59 notifier_chain_unregister(&panic_notifier_list, &panic_notifier);
60}
61
62
63int ibmasm_heartbeat_init(struct service_processor *sp)
64{
65 sp->heartbeat = ibmasm_new_command(HEARTBEAT_BUFFER_SIZE);
66 if (sp->heartbeat == NULL)
67 return -ENOMEM;
68
69 return 0;
70}
71
72void ibmasm_heartbeat_exit(struct service_processor *sp)
73{
74 command_put(sp->heartbeat);
75}
76
77void ibmasm_receive_heartbeat(struct service_processor *sp, void *message, size_t size)
78{
79 struct command *cmd = sp->heartbeat;
80 struct dot_command_header *header = (struct dot_command_header *)cmd->buffer;
81
82 if (suspend_heartbeats)
83 return;
84
85 /* return the received dot command to sender */
86 cmd->status = IBMASM_CMD_PENDING;
87 size = min(size, cmd->buffer_size);
88 memcpy(cmd->buffer, message, size);
89 header->type = sp_write;
90 ibmasm_exec_command(sp, cmd);
91}