aboutsummaryrefslogtreecommitdiff
path: root/drivers/misc/ibmasm/command.c
blob: 7d56f45dee198a38afbbb808bfe53d46e42d487b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187

/*
 * IBM ASM Service Processor Device Driver
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Copyright (C) IBM Corporation, 2004
 *
 * Author: Max Asböck <amax@us.ibm.com>
 *
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include "ibmasm.h"
#include "lowlevel.h"

static void exec_next_command(struct service_processor *sp);

static atomic_t command_count = ATOMIC_INIT(0);

struct command *ibmasm_new_command(struct service_processor *sp, size_t buffer_size)
{
	struct command *cmd;

	if (buffer_size > IBMASM_CMD_MAX_BUFFER_SIZE)
		return NULL;

	cmd = kzalloc(sizeof(struct command), GFP_KERNEL);
	if (cmd == NULL)
		return NULL;


	cmd->buffer = kzalloc(buffer_size, GFP_KERNEL);
	if (cmd->buffer == NULL) {
		kfree(cmd);
		return NULL;
	}
	cmd->buffer_size = buffer_size;

	kref_init(&cmd->kref);
	cmd->lock = &sp->lock;

	cmd->status = IBMASM_CMD_PENDING;
	init_waitqueue_head(&cmd->wait);
	INIT_LIST_HEAD(&cmd->queue_node);

	atomic_inc(&command_count);
	dbg("command count: %d\n", atomic_read(&command_count));

	return cmd;
}

void ibmasm_free_command(struct kref *kref)
{
	struct command *cmd = to_command(kref);

	list_del(&cmd->queue_node);
	atomic_dec(&command_count);
	dbg("command count: %d\n", atomic_read(&command_count));
	kfree(cmd->buffer);
	kfree(cmd);
}

static void enqueue_command(struct service_processor *sp, struct command *cmd)
{
	list_add_tail(&cmd->queue_node, &sp->command_queue);
}

static struct command *dequeue_command(struct service_processor *sp)
{
	struct command *cmd;
	struct list_head *next;

	if (list_empty(&sp->command_queue))
		return NULL;

	next = sp->command_queue.next;
	list_del_init(next);
	cmd = list_entry(next, struct command, queue_node);

	return cmd;
}

static inline void do_exec_command(struct service_processor *sp)
{
	char tsbuf[32];

	dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));

	if (ibmasm_send_i2o_message(sp)) {
		sp->current_command->status = IBMASM_CMD_FAILED;
		wake_up(&sp->current_command->wait);
		command_put(sp->current_command);
		exec_next_command(sp);
	}
}

/**
 * exec_command
 * send a command to a service processor
 * Commands are executed sequentially. One command (sp->current_command)
 * is sent to the service processor. Once the interrupt handler gets a
 * message of type command_response, the message is copied into
 * the current commands buffer,
 */
void ibmasm_exec_command(struct service_processor *sp, struct command *cmd)
{
	unsigned long flags;
	char tsbuf[32];

	dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));

	spin_lock_irqsave(&sp->lock, flags);

	if (!sp->current_command) {
		sp->current_command = cmd;
		command_get(sp->current_command);
		spin_unlock_irqrestore(&sp->lock, flags);
		do_exec_command(sp);
	} else {
		enqueue_command(sp, cmd);
		spin_unlock_irqrestore(&sp->lock, flags);
	}
}

static void exec_next_command(struct service_processor *sp)
{
	unsigned long flags;
	char tsbuf[32];

	dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));

	spin_lock_irqsave(&sp->lock, flags);
	sp->current_command = dequeue_command(sp);
	if (sp->current_command) {
		command_get(sp->current_command);
		spin_unlock_irqrestore(&sp->lock, flags);
		do_exec_command(sp);
	} else {
		spin_unlock_irqrestore(&sp->lock, flags);
	}
}

/**
 * Sleep until a command has failed or a response has been received
 * and the command status been updated by the interrupt handler.
 * (see receive_response).
 */
void ibmasm_wait_for_response(struct command *cmd, int timeout)
{
	wait_event_interruptible_timeout(cmd->wait,
				cmd->status == IBMASM_CMD_COMPLETE ||
				cmd->status == IBMASM_CMD_FAILED,
				timeout * HZ);
}

/**
 * receive_command_response
 * called by the interrupt handler when a dot command of type command_response
 * was received.
 */
void ibmasm_receive_command_response(struct service_processor *sp, void *response, size_t size)
{
	struct command *cmd = sp->current_command;

	if (!sp->current_command)
		return;

	memcpy_fromio(cmd->buffer, response, min(size, cmd->buffer_size));
	cmd->status = IBMASM_CMD_COMPLETE;
	wake_up(&sp->current_command->wait);
	command_put(sp->current_command);
	exec_next_command(sp);
}