command.c revision 3110dc7a8660ea1617afac2a55e3d18ae6ce141b 
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);
29static void free_command(struct kobject *kobj);
30
31static struct kobj_type ibmasm_cmd_kobj_type = {
32	.release = free_command,
33};
34
35static atomic_t command_count = ATOMIC_INIT(0);
36
37struct command *ibmasm_new_command(struct service_processor *sp, size_t buffer_size)
38{
39	struct command *cmd;
40
41	if (buffer_size > IBMASM_CMD_MAX_BUFFER_SIZE)
42		return NULL;
43
44	cmd = kmalloc(sizeof(struct command), GFP_KERNEL);
45	if (cmd == NULL)
46		return NULL;
47
48	memset(cmd, 0, sizeof(*cmd));
49
50	cmd->buffer = kmalloc(buffer_size, GFP_KERNEL);
51	if (cmd->buffer == NULL) {
52		kfree(cmd);
53		return NULL;
54	}
55	memset(cmd->buffer, 0, buffer_size);
56	cmd->buffer_size = buffer_size;
57
58	kobject_init(&cmd->kobj);
59	cmd->kobj.ktype = &ibmasm_cmd_kobj_type;
60	cmd->lock = &sp->lock;
61
62	cmd->status = IBMASM_CMD_PENDING;
63	init_waitqueue_head(&cmd->wait);
64	INIT_LIST_HEAD(&cmd->queue_node);
65
66	atomic_inc(&command_count);
67	dbg("command count: %d\n", atomic_read(&command_count));
68
69	return cmd;
70}
71
72static void free_command(struct kobject *kobj)
73{
74	struct command *cmd = to_command(kobj);
75
76	list_del(&cmd->queue_node);
77	atomic_dec(&command_count);
78	dbg("command count: %d\n", atomic_read(&command_count));
79	kfree(cmd->buffer);
80	kfree(cmd);
81}
82
83static void enqueue_command(struct service_processor *sp, struct command *cmd)
84{
85	list_add_tail(&cmd->queue_node, &sp->command_queue);
86}
87
88static struct command *dequeue_command(struct service_processor *sp)
89{
90	struct command *cmd;
91	struct list_head *next;
92
93	if (list_empty(&sp->command_queue))
94		return NULL;
95
96	next = sp->command_queue.next;
97	list_del_init(next);
98	cmd = list_entry(next, struct command, queue_node);
99
100	return cmd;
101}
102
103static inline void do_exec_command(struct service_processor *sp)
104{
105	char tsbuf[32];
106
107	dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
108
109	if (ibmasm_send_i2o_message(sp)) {
110		sp->current_command->status = IBMASM_CMD_FAILED;
111		wake_up(&sp->current_command->wait);
112		command_put(sp->current_command);
113		exec_next_command(sp);
114	}
115}
116
117/**
118 * exec_command
119 * send a command to a service processor
120 * Commands are executed sequentially. One command (sp->current_command)
121 * is sent to the service processor. Once the interrupt handler gets a
122 * message of type command_response, the message is copied into
123 * the current commands buffer,
124 */
125void ibmasm_exec_command(struct service_processor *sp, struct command *cmd)
126{
127	unsigned long flags;
128	char tsbuf[32];
129
130	dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
131
132	spin_lock_irqsave(&sp->lock, flags);
133
134	if (!sp->current_command) {
135		sp->current_command = cmd;
136		command_get(sp->current_command);
137		spin_unlock_irqrestore(&sp->lock, flags);
138		do_exec_command(sp);
139	} else {
140		enqueue_command(sp, cmd);
141		spin_unlock_irqrestore(&sp->lock, flags);
142	}
143}
144
145static void exec_next_command(struct service_processor *sp)
146{
147	unsigned long flags;
148	char tsbuf[32];
149
150	dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
151
152	spin_lock_irqsave(&sp->lock, flags);
153	sp->current_command = dequeue_command(sp);
154	if (sp->current_command) {
155		command_get(sp->current_command);
156		spin_unlock_irqrestore(&sp->lock, flags);
157		do_exec_command(sp);
158	} else {
159		spin_unlock_irqrestore(&sp->lock, flags);
160	}
161}
162
163/**
164 * Sleep until a command has failed or a response has been received
165 * and the command status been updated by the interrupt handler.
166 * (see receive_response).
167 */
168void ibmasm_wait_for_response(struct command *cmd, int timeout)
169{
170	wait_event_interruptible_timeout(cmd->wait,
171				cmd->status == IBMASM_CMD_COMPLETE ||
172				cmd->status == IBMASM_CMD_FAILED,
173				timeout * HZ);
174}
175
176/**
177 * receive_command_response
178 * called by the interrupt handler when a dot command of type command_response
179 * was received.
180 */
181void ibmasm_receive_command_response(struct service_processor *sp, void *response, size_t size)
182{
183	struct command *cmd = sp->current_command;
184
185	if (!sp->current_command)
186		return;
187
188	memcpy_fromio(cmd->buffer, response, min(size, cmd->buffer_size));
189	cmd->status = IBMASM_CMD_COMPLETE;
190	wake_up(&sp->current_command->wait);
191	command_put(sp->current_command);
192	exec_next_command(sp);
193}
194