Linux 2.6.34-rc3
[pohmelfs.git] / drivers / misc / ibmasm / command.c
blobe2031739aa29fda4a188d4ac35101bc9f7439ee0
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 <linux/sched.h>
26 #include "ibmasm.h"
27 #include "lowlevel.h"
29 static void exec_next_command(struct service_processor *sp);
31 static atomic_t command_count = ATOMIC_INIT(0);
33 struct command *ibmasm_new_command(struct service_processor *sp, size_t buffer_size)
35 struct command *cmd;
37 if (buffer_size > IBMASM_CMD_MAX_BUFFER_SIZE)
38 return NULL;
40 cmd = kzalloc(sizeof(struct command), GFP_KERNEL);
41 if (cmd == NULL)
42 return NULL;
45 cmd->buffer = kzalloc(buffer_size, GFP_KERNEL);
46 if (cmd->buffer == NULL) {
47 kfree(cmd);
48 return NULL;
50 cmd->buffer_size = buffer_size;
52 kref_init(&cmd->kref);
53 cmd->lock = &sp->lock;
55 cmd->status = IBMASM_CMD_PENDING;
56 init_waitqueue_head(&cmd->wait);
57 INIT_LIST_HEAD(&cmd->queue_node);
59 atomic_inc(&command_count);
60 dbg("command count: %d\n", atomic_read(&command_count));
62 return cmd;
65 void ibmasm_free_command(struct kref *kref)
67 struct command *cmd = to_command(kref);
69 list_del(&cmd->queue_node);
70 atomic_dec(&command_count);
71 dbg("command count: %d\n", atomic_read(&command_count));
72 kfree(cmd->buffer);
73 kfree(cmd);
76 static void enqueue_command(struct service_processor *sp, struct command *cmd)
78 list_add_tail(&cmd->queue_node, &sp->command_queue);
81 static struct command *dequeue_command(struct service_processor *sp)
83 struct command *cmd;
84 struct list_head *next;
86 if (list_empty(&sp->command_queue))
87 return NULL;
89 next = sp->command_queue.next;
90 list_del_init(next);
91 cmd = list_entry(next, struct command, queue_node);
93 return cmd;
96 static inline void do_exec_command(struct service_processor *sp)
98 char tsbuf[32];
100 dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
102 if (ibmasm_send_i2o_message(sp)) {
103 sp->current_command->status = IBMASM_CMD_FAILED;
104 wake_up(&sp->current_command->wait);
105 command_put(sp->current_command);
106 exec_next_command(sp);
111 * exec_command
112 * send a command to a service processor
113 * Commands are executed sequentially. One command (sp->current_command)
114 * is sent to the service processor. Once the interrupt handler gets a
115 * message of type command_response, the message is copied into
116 * the current commands buffer,
118 void ibmasm_exec_command(struct service_processor *sp, struct command *cmd)
120 unsigned long flags;
121 char tsbuf[32];
123 dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
125 spin_lock_irqsave(&sp->lock, flags);
127 if (!sp->current_command) {
128 sp->current_command = cmd;
129 command_get(sp->current_command);
130 spin_unlock_irqrestore(&sp->lock, flags);
131 do_exec_command(sp);
132 } else {
133 enqueue_command(sp, cmd);
134 spin_unlock_irqrestore(&sp->lock, flags);
138 static void exec_next_command(struct service_processor *sp)
140 unsigned long flags;
141 char tsbuf[32];
143 dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
145 spin_lock_irqsave(&sp->lock, flags);
146 sp->current_command = dequeue_command(sp);
147 if (sp->current_command) {
148 command_get(sp->current_command);
149 spin_unlock_irqrestore(&sp->lock, flags);
150 do_exec_command(sp);
151 } else {
152 spin_unlock_irqrestore(&sp->lock, flags);
157 * Sleep until a command has failed or a response has been received
158 * and the command status been updated by the interrupt handler.
159 * (see receive_response).
161 void ibmasm_wait_for_response(struct command *cmd, int timeout)
163 wait_event_interruptible_timeout(cmd->wait,
164 cmd->status == IBMASM_CMD_COMPLETE ||
165 cmd->status == IBMASM_CMD_FAILED,
166 timeout * HZ);
170 * receive_command_response
171 * called by the interrupt handler when a dot command of type command_response
172 * was received.
174 void ibmasm_receive_command_response(struct service_processor *sp, void *response, size_t size)
176 struct command *cmd = sp->current_command;
178 if (!sp->current_command)
179 return;
181 memcpy_fromio(cmd->buffer, response, min(size, cmd->buffer_size));
182 cmd->status = IBMASM_CMD_COMPLETE;
183 wake_up(&sp->current_command->wait);
184 command_put(sp->current_command);
185 exec_next_command(sp);