V4L/DVB (6715): ivtv: Remove unnecessary register update
[linux-2.6/verdex.git] / drivers / misc / ibmasm / command.c
blob1a0e7978226a6b593e048e31ef00e4e40dd13d41
2 /*
3 * IBM ASM Service Processor Device Driver
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.
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.
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.
19 * Copyright (C) IBM Corporation, 2004
21 * Author: Max Asböck <amax@us.ibm.com>
25 #include "ibmasm.h"
26 #include "lowlevel.h"
28 static void exec_next_command(struct service_processor *sp);
30 static atomic_t command_count = ATOMIC_INIT(0);
32 struct command *ibmasm_new_command(struct service_processor *sp, size_t buffer_size)
34 struct command *cmd;
36 if (buffer_size > IBMASM_CMD_MAX_BUFFER_SIZE)
37 return NULL;
39 cmd = kzalloc(sizeof(struct command), GFP_KERNEL);
40 if (cmd == NULL)
41 return NULL;
44 cmd->buffer = kzalloc(buffer_size, GFP_KERNEL);
45 if (cmd->buffer == NULL) {
46 kfree(cmd);
47 return NULL;
49 cmd->buffer_size = buffer_size;
51 kref_init(&cmd->kref);
52 cmd->lock = &sp->lock;
54 cmd->status = IBMASM_CMD_PENDING;
55 init_waitqueue_head(&cmd->wait);
56 INIT_LIST_HEAD(&cmd->queue_node);
58 atomic_inc(&command_count);
59 dbg("command count: %d\n", atomic_read(&command_count));
61 return cmd;
64 void ibmasm_free_command(struct kref *kref)
66 struct command *cmd = to_command(kref);
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);
75 static void enqueue_command(struct service_processor *sp, struct command *cmd)
77 list_add_tail(&cmd->queue_node, &sp->command_queue);
80 static struct command *dequeue_command(struct service_processor *sp)
82 struct command *cmd;
83 struct list_head *next;
85 if (list_empty(&sp->command_queue))
86 return NULL;
88 next = sp->command_queue.next;
89 list_del_init(next);
90 cmd = list_entry(next, struct command, queue_node);
92 return cmd;
95 static inline void do_exec_command(struct service_processor *sp)
97 char tsbuf[32];
99 dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
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);
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,
117 void ibmasm_exec_command(struct service_processor *sp, struct command *cmd)
119 unsigned long flags;
120 char tsbuf[32];
122 dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
124 spin_lock_irqsave(&sp->lock, flags);
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);
137 static void exec_next_command(struct service_processor *sp)
139 unsigned long flags;
140 char tsbuf[32];
142 dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));
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);
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).
160 void ibmasm_wait_for_response(struct command *cmd, int timeout)
162 wait_event_interruptible_timeout(cmd->wait,
163 cmd->status == IBMASM_CMD_COMPLETE ||
164 cmd->status == IBMASM_CMD_FAILED,
165 timeout * HZ);
169 * receive_command_response
170 * called by the interrupt handler when a dot command of type command_response
171 * was received.
173 void ibmasm_receive_command_response(struct service_processor *sp, void *response, size_t size)
175 struct command *cmd = sp->current_command;
177 if (!sp->current_command)
178 return;
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);