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 Asb�ck <amax@us.ibm.com>
20 *
21 */
22
23#include "ibmasm.h"
24#include "dot_command.h"
25
26/*
27 * Reverse Heartbeat, i.e. heartbeats sent from the driver to the
28 * service processor.
29 * These heartbeats are initiated by user level programs.
30 */
31
32/* the reverse heartbeat dot command */
33#pragma pack(1)
34static struct {
35	struct dot_command_header	header;
36	unsigned char			command[3];
37} rhb_dot_cmd = {
38	.header = {
39		.type = 	sp_read,
40		.command_size = 3,
41		.data_size =	0,
42		.status = 	0
43	},
44	.command = { 4, 3, 6 }
45};
46#pragma pack()
47
48void ibmasm_init_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb)
49{
50	init_waitqueue_head(&rhb->wait);
51	rhb->stopped = 0;
52}
53
54/**
55 * start_reverse_heartbeat
56 * Loop forever, sending a reverse heartbeat dot command to the service
57 * processor, then sleeping. The loop comes to an end if the service
58 * processor fails to respond 3 times or we were interrupted.
59 */
60int ibmasm_start_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb)
61{
62	struct command *cmd;
63	int times_failed = 0;
64	int result = 1;
65
66	cmd = ibmasm_new_command(sp, sizeof rhb_dot_cmd);
67	if (!cmd)
68		return -ENOMEM;
69
70	while (times_failed < 3) {
71		memcpy(cmd->buffer, (void *)&rhb_dot_cmd, sizeof rhb_dot_cmd);
72		cmd->status = IBMASM_CMD_PENDING;
73		ibmasm_exec_command(sp, cmd);
74		ibmasm_wait_for_response(cmd, IBMASM_CMD_TIMEOUT_NORMAL);
75
76		if (cmd->status != IBMASM_CMD_COMPLETE)
77			times_failed++;
78
79		wait_event_interruptible_timeout(rhb->wait,
80			rhb->stopped,
81			REVERSE_HEARTBEAT_TIMEOUT * HZ);
82
83		if (signal_pending(current) || rhb->stopped) {
84			result = -EINTR;
85			break;
86		}
87	}
88	command_put(cmd);
89	rhb->stopped = 0;
90
91	return result;
92}
93
94void ibmasm_stop_reverse_heartbeat(struct reverse_heartbeat *rhb)
95{
96	rhb->stopped = 1;
97	wake_up_interruptible(&rhb->wait);
98}
99