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)
34 static 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 
48 void 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  */
60 int 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 
94 void ibmasm_stop_reverse_heartbeat(struct reverse_heartbeat *rhb)
95 {
96 	rhb->stopped = 1;
97 	wake_up_interruptible(&rhb->wait);
98 }
99