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)
35static 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
49void 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 */
61int 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
95void ibmasm_stop_reverse_heartbeat(struct reverse_heartbeat *rhb)
96{
97	rhb->stopped = 1;
98	wake_up_interruptible(&rhb->wait);
99}
100