command.c revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 
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
27static void exec_next_command(struct service_processor *sp);
28static void free_command(struct kobject *kobj);
29
30static struct kobj_type ibmasm_cmd_kobj_type = {
31	.release = free_command,
32};
33
34
35struct command *ibmasm_new_command(size_t buffer_size)
36{
37	struct command *cmd;
38
39	if (buffer_size > IBMASM_CMD_MAX_BUFFER_SIZE)
40		return NULL;
41
42	cmd = kmalloc(sizeof(struct command), GFP_KERNEL);
43	if (cmd == NULL)
44		return NULL;
45
46	memset(cmd, 0, sizeof(*cmd));
47
48	cmd->buffer = kmalloc(buffer_size, GFP_KERNEL);
49	if (cmd->buffer == NULL) {
50		kfree(cmd);
51		return NULL;
52	}
53	memset(cmd->buffer, 0, buffer_size);
54	cmd->buffer_size = buffer_size;
55
56	kobject_init(&cmd->kobj);
57	cmd->kobj.ktype = &ibmasm_cmd_kobj_type;
58
59	cmd->status = IBMASM_CMD_PENDING;
60	init_waitqueue_head(&cmd->wait);
61	INIT_LIST_HEAD(&cmd->queue_node);
62
63	return cmd;
64}
65
66static void free_command(struct kobject *kobj)
67{
68	struct command *cmd = to_command(kobj);
69
70	list_del(&cmd->queue_node);
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	if (ibmasm_send_i2o_message(sp)) {
98		sp->current_command->status = IBMASM_CMD_FAILED;
99		exec_next_command(sp);
100	}
101}
102
103/**
104 * exec_command
105 * send a command to a service processor
106 * Commands are executed sequentially. One command (sp->current_command)
107 * is sent to the service processor. Once the interrupt handler gets a
108 * message of type command_response, the message is copied into
109 * the current commands buffer,
110 */
111void ibmasm_exec_command(struct service_processor *sp, struct command *cmd)
112{
113	unsigned long flags;
114
115	spin_lock_irqsave(&sp->lock, flags);
116
117	if (!sp->current_command) {
118		command_get(cmd);
119		sp->current_command = cmd;
120		spin_unlock_irqrestore(&sp->lock, flags);
121
122		do_exec_command(sp);
123	} else {
124		enqueue_command(sp, cmd);
125		spin_unlock_irqrestore(&sp->lock, flags);
126	}
127}
128
129static void exec_next_command(struct service_processor *sp)
130{
131	unsigned long flags;
132
133	wake_up(&sp->current_command->wait);
134	command_put(sp->current_command);
135
136	spin_lock_irqsave(&sp->lock, flags);
137	sp->current_command = dequeue_command(sp);
138	if (sp->current_command) {
139		command_get(sp->current_command);
140		spin_unlock_irqrestore(&sp->lock, flags);
141		do_exec_command(sp);
142	} else {
143		spin_unlock_irqrestore(&sp->lock, flags);
144	}
145}
146
147/**
148 * Sleep until a command has failed or a response has been received
149 * and the command status been updated by the interrupt handler.
150 * (see receive_response).
151 */
152void ibmasm_wait_for_response(struct command *cmd, int timeout)
153{
154	wait_event_interruptible_timeout(cmd->wait,
155				cmd->status == IBMASM_CMD_COMPLETE ||
156				cmd->status == IBMASM_CMD_FAILED,
157				timeout * HZ);
158}
159
160/**
161 * receive_command_response
162 * called by the interrupt handler when a dot command of type command_response
163 * was received.
164 */
165void ibmasm_receive_command_response(struct service_processor *sp, void *response, size_t size)
166{
167	struct command *cmd = sp->current_command;
168
169	if (!sp->current_command)
170		return;
171
172	memcpy(cmd->buffer, response, min(size, cmd->buffer_size));
173	cmd->status = IBMASM_CMD_COMPLETE;
174	exec_next_command(sp);
175}
176