Update copyrights
[linux-2.6.git] / drivers / misc / ibmasm / r_heartbeat.c
1
2 /*
3  * This program is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License as published by
5  * the Free Software Foundation; either version 2 of the License, or
6  * (at your option) any later version.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, write to the Free Software
15  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
16  *
17  * Copyright (C) IBM Corporation, 2004
18  *
19  * Author: Max Asböck <amax@us.ibm.com>
20  *
21  */
22
23 #include <linux/sched.h>
24 #include "ibmasm.h"
25 #include "dot_command.h"
26
27 /*
28  * Reverse Heartbeat, i.e. heartbeats sent from the driver to the
29  * service processor.
30  * These heartbeats are initiated by user level programs.
31  */
32
33 /* the reverse heartbeat dot command */
34 #pragma pack(1)
35 static struct {
36         struct dot_command_header       header;
37         unsigned char                   command[3];
38 } rhb_dot_cmd = {
39         .header = {
40                 .type =         sp_read,
41                 .command_size = 3,
42                 .data_size =    0,
43                 .status =       0
44         },
45         .command = { 4, 3, 6 }
46 };
47 #pragma pack()
48
49 void ibmasm_init_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb)
50 {
51         init_waitqueue_head(&rhb->wait);
52         rhb->stopped = 0;
53 }
54
55 /**
56  * start_reverse_heartbeat
57  * Loop forever, sending a reverse heartbeat dot command to the service
58  * processor, then sleeping. The loop comes to an end if the service
59  * processor fails to respond 3 times or we were interrupted.
60  */
61 int ibmasm_start_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb)
62 {
63         struct command *cmd;
64         int times_failed = 0;
65         int result = 1;
66
67         cmd = ibmasm_new_command(sp, sizeof rhb_dot_cmd);
68         if (!cmd)
69                 return -ENOMEM;
70
71         while (times_failed < 3) {
72                 memcpy(cmd->buffer, (void *)&rhb_dot_cmd, sizeof rhb_dot_cmd);
73                 cmd->status = IBMASM_CMD_PENDING;
74                 ibmasm_exec_command(sp, cmd);
75                 ibmasm_wait_for_response(cmd, IBMASM_CMD_TIMEOUT_NORMAL);
76
77                 if (cmd->status != IBMASM_CMD_COMPLETE)
78                         times_failed++;
79
80                 wait_event_interruptible_timeout(rhb->wait,
81                         rhb->stopped,
82                         REVERSE_HEARTBEAT_TIMEOUT * HZ);
83
84                 if (signal_pending(current) || rhb->stopped) {
85                         result = -EINTR;
86                         break;
87                 }
88         }
89         command_put(cmd);
90         rhb->stopped = 0;
91
92         return result;
93 }
94
95 void ibmasm_stop_reverse_heartbeat(struct reverse_heartbeat *rhb)
96 {
97         rhb->stopped = 1;
98         wake_up_interruptible(&rhb->wait);
99 }