command.c revision a045171f875cd61f690981a78ab98fbd137c938b 
1
2/*
3 * IBM ASM Service Processor Device Driver
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 *
19 * Copyright (C) IBM Corporation, 2004
20 *
21 * Author: Max Asb�ck <amax@us.ibm.com>
22 *
23 */
24
25#include "ibmasm.h"
26#include "lowlevel.h"
27
28static void exec_next_command(struct service_processor *sp);
29
30static atomic_t command_count = ATOMIC_INIT(0);
31
32struct command *ibmasm_new_command(struct service_processor *sp, size_t buffer_size)
33{
34	struct command *cmd;
35
36	if (buffer_size > IBMASM_CMD_MAX_BUFFER_SIZE)
37		return NULL;
38
39	cmd = kzalloc(sizeof(struct command), GFP_KERNEL);
40	if (cmd == NULL)
41		return NULL;
42
43
44	cmd->buffer = kzalloc(buffer_size, GFP_KERNEL);
45	if (cmd->buffer == NULL) {
46		kfree(cmd);
47		return NULL;
48	}
49	cmd->buffer_size = buffer_size;
50
51	kref_init(&cmd->kref);
52	cmd->lock = &sp->lock;
53
54	cmd->status = IBMASM_CMD_PENDING;
55	init_waitqueue_head(&cmd->wait);
56	INIT_LIST_HEAD(&cmd->queue_node);
57
58	atomic_inc(&command_count);
59	dbg("command count: %d\n", atomic_read(&command_count));
60
61	return cmd;
62}
63
64void ibmasm_free_command(struct kref *kref)
65{
66	struct command *cmd = to_command(kref);
67
68	list_del(&cmd->queue_node);
69	atomic_dec(&command_count);
70	dbg("command count: %d\n", atomic_read(&command_count));
71	kfree(cmd->buffer);
72	kfree(cmd);
73}
74
75static void enqueue_command(struct service_processor *sp, struct command *cmd)
76{
77	list_add_tail(&cmd->queue_node, &sp->command_queue);
78}
79
80static struct command *dequeue_command(struct service_processor *sp)
81{
82	struct command *cmd;
83	struct list_head *next;
84
85	if (list_empty(&sp->command_queue))
86		return NULL;
87
88	next = sp->command_queue.next;
89	list_del_init(next);
90	cmd = list_entry(next, struct command, queue_node);
91
92	return cmd;
93}
94
95static inline void do_exec_command(struct service_processor *sp)
96{
97	char tsbuf[32];
98
99	dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
100
101	if (ibmasm_send_i2o_message(sp)) {
102		sp->current_command->status = IBMASM_CMD_FAILED;
103		wake_up(&sp->current_command->wait);
104		command_put(sp->current_command);
105		exec_next_command(sp);
106	}
107}
108
109/**
110 * exec_command
111 * send a command to a service processor
112 * Commands are executed sequentially. One command (sp->current_command)
113 * is sent to the service processor. Once the interrupt handler gets a
114 * message of type command_response, the message is copied into
115 * the current commands buffer,
116 */
117void ibmasm_exec_command(struct service_processor *sp, struct command *cmd)
118{
119	unsigned long flags;
120	char tsbuf[32];
121
122	dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
123
124	spin_lock_irqsave(&sp->lock, flags);
125
126	if (!sp->current_command) {
127		sp->current_command = cmd;
128		command_get(sp->current_command);
129		spin_unlock_irqrestore(&sp->lock, flags);
130		do_exec_command(sp);
131	} else {
132		enqueue_command(sp, cmd);
133		spin_unlock_irqrestore(&sp->lock, flags);
134	}
135}
136
137static void exec_next_command(struct service_processor *sp)
138{
139	unsigned long flags;
140	char tsbuf[32];
141
142	dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
143
144	spin_lock_irqsave(&sp->lock, flags);
145	sp->current_command = dequeue_command(sp);
146	if (sp->current_command) {
147		command_get(sp->current_command);
148		spin_unlock_irqrestore(&sp->lock, flags);
149		do_exec_command(sp);
150	} else {
151		spin_unlock_irqrestore(&sp->lock, flags);
152	}
153}
154
155/**
156 * Sleep until a command has failed or a response has been received
157 * and the command status been updated by the interrupt handler.
158 * (see receive_response).
159 */
160void ibmasm_wait_for_response(struct command *cmd, int timeout)
161{
162	wait_event_interruptible_timeout(cmd->wait,
163				cmd->status == IBMASM_CMD_COMPLETE ||
164				cmd->status == IBMASM_CMD_FAILED,
165				timeout * HZ);
166}
167
168/**
169 * receive_command_response
170 * called by the interrupt handler when a dot command of type command_response
171 * was received.
172 */
173void ibmasm_receive_command_response(struct service_processor *sp, void *response, size_t size)
174{
175	struct command *cmd = sp->current_command;
176
177	if (!sp->current_command)
178		return;
179
180	memcpy_fromio(cmd->buffer, response, min(size, cmd->buffer_size));
181	cmd->status = IBMASM_CMD_COMPLETE;
182	wake_up(&sp->current_command->wait);
183	command_put(sp->current_command);
184	exec_next_command(sp);
185}
186