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