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Merge branch 'release' of git://lm-sensors.org/kernel/mhoffman/hwmon-2.6
[linux-2.6-omap-h63xx.git] / drivers / misc / ibmasm / command.c
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 Asböck <amax@us.ibm.com>
22  *
23  */
24
25 #include "ibmasm.h"
26 #include "lowlevel.h"
27
28 static void exec_next_command(struct service_processor *sp);
29 static void free_command(struct kobject *kobj);
30
31 static struct kobj_type ibmasm_cmd_kobj_type = {
32         .release = free_command,
33 };
34
35 static atomic_t command_count = ATOMIC_INIT(0);
36
37 struct 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 = kzalloc(sizeof(struct command), GFP_KERNEL);
45         if (cmd == NULL)
46                 return NULL;
47
48
49         cmd->buffer = kzalloc(buffer_size, GFP_KERNEL);
50         if (cmd->buffer == NULL) {
51                 kfree(cmd);
52                 return NULL;
53         }
54         cmd->buffer_size = buffer_size;
55
56         kobject_init(&cmd->kobj);
57         cmd->kobj.ktype = &ibmasm_cmd_kobj_type;
58         cmd->lock = &sp->lock;
59
60         cmd->status = IBMASM_CMD_PENDING;
61         init_waitqueue_head(&cmd->wait);
62         INIT_LIST_HEAD(&cmd->queue_node);
63
64         atomic_inc(&command_count);
65         dbg("command count: %d\n", atomic_read(&command_count));
66
67         return cmd;
68 }
69
70 static void free_command(struct kobject *kobj)
71 {
72         struct command *cmd = to_command(kobj);
73
74         list_del(&cmd->queue_node);
75         atomic_dec(&command_count);
76         dbg("command count: %d\n", atomic_read(&command_count));
77         kfree(cmd->buffer);
78         kfree(cmd);
79 }
80
81 static void enqueue_command(struct service_processor *sp, struct command *cmd)
82 {
83         list_add_tail(&cmd->queue_node, &sp->command_queue);
84 }
85
86 static struct command *dequeue_command(struct service_processor *sp)
87 {
88         struct command *cmd;
89         struct list_head *next;
90
91         if (list_empty(&sp->command_queue))
92                 return NULL;
93
94         next = sp->command_queue.next;
95         list_del_init(next);
96         cmd = list_entry(next, struct command, queue_node);
97
98         return cmd;
99 }
100
101 static inline void do_exec_command(struct service_processor *sp)
102 {
103         char tsbuf[32];
104
105         dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
106
107         if (ibmasm_send_i2o_message(sp)) {
108                 sp->current_command->status = IBMASM_CMD_FAILED;
109                 wake_up(&sp->current_command->wait);
110                 command_put(sp->current_command);
111                 exec_next_command(sp);
112         }
113 }
114
115 /**
116  * exec_command
117  * send a command to a service processor
118  * Commands are executed sequentially. One command (sp->current_command)
119  * is sent to the service processor. Once the interrupt handler gets a
120  * message of type command_response, the message is copied into
121  * the current commands buffer,
122  */
123 void ibmasm_exec_command(struct service_processor *sp, struct command *cmd)
124 {
125         unsigned long flags;
126         char tsbuf[32];
127
128         dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
129
130         spin_lock_irqsave(&sp->lock, flags);
131
132         if (!sp->current_command) {
133                 sp->current_command = cmd;
134                 command_get(sp->current_command);
135                 spin_unlock_irqrestore(&sp->lock, flags);
136                 do_exec_command(sp);
137         } else {
138                 enqueue_command(sp, cmd);
139                 spin_unlock_irqrestore(&sp->lock, flags);
140         }
141 }
142
143 static void exec_next_command(struct service_processor *sp)
144 {
145         unsigned long flags;
146         char tsbuf[32];
147
148         dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
149
150         spin_lock_irqsave(&sp->lock, flags);
151         sp->current_command = dequeue_command(sp);
152         if (sp->current_command) {
153                 command_get(sp->current_command);
154                 spin_unlock_irqrestore(&sp->lock, flags);
155                 do_exec_command(sp);
156         } else {
157                 spin_unlock_irqrestore(&sp->lock, flags);
158         }
159 }
160
161 /**
162  * Sleep until a command has failed or a response has been received
163  * and the command status been updated by the interrupt handler.
164  * (see receive_response).
165  */
166 void ibmasm_wait_for_response(struct command *cmd, int timeout)
167 {
168         wait_event_interruptible_timeout(cmd->wait,
169                                 cmd->status == IBMASM_CMD_COMPLETE ||
170                                 cmd->status == IBMASM_CMD_FAILED,
171                                 timeout * HZ);
172 }
173
174 /**
175  * receive_command_response
176  * called by the interrupt handler when a dot command of type command_response
177  * was received.
178  */
179 void ibmasm_receive_command_response(struct service_processor *sp, void *response, size_t size)
180 {
181         struct command *cmd = sp->current_command;
182
183         if (!sp->current_command)
184                 return;
185
186         memcpy_fromio(cmd->buffer, response, min(size, cmd->buffer_size));
187         cmd->status = IBMASM_CMD_COMPLETE;
188         wake_up(&sp->current_command->wait);
189         command_put(sp->current_command);
190         exec_next_command(sp);
191 }