[PATCH] ibmasm driver: fix race in command refcount logic
[linux-2.6.git] / drivers / misc / ibmasm / dot_command.c
1 /*
2  * IBM ASM Service Processor Device Driver
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17  *
18  * Copyright (C) IBM Corporation, 2004
19  *
20  * Author: Max Asböck <amax@us.ibm.com> 
21  *
22  */
23
24 #include "ibmasm.h"
25 #include "dot_command.h"
26
27 /**
28  * Dispatch an incoming message to the specific handler for the message.
29  * Called from interrupt context.
30  */
31 void ibmasm_receive_message(struct service_processor *sp, void *message, int message_size)
32 {
33         u32 size;
34         struct dot_command_header *header = (struct dot_command_header *)message;
35
36         if (message_size == 0)
37                 return;
38
39         size = get_dot_command_size(message);
40         if (size == 0)
41                 return;
42
43         if (size > message_size)
44                 size = message_size;
45
46         switch (header->type) {
47         case sp_event: 
48                 ibmasm_receive_event(sp, message, size);
49                 break;
50         case sp_command_response:
51                 ibmasm_receive_command_response(sp, message, size); 
52                 break;
53         case sp_heartbeat:
54                 ibmasm_receive_heartbeat(sp, message, size);
55                 break;
56         default:
57                 dev_err(sp->dev, "Received unknown message from service processor\n");
58         }
59 }
60
61
62 #define INIT_BUFFER_SIZE 32
63
64
65 /**
66  * send the 4.3.5.10 dot command (driver VPD) to the service processor
67  */
68 int ibmasm_send_driver_vpd(struct service_processor *sp)
69 {
70         struct command *command;
71         struct dot_command_header *header;
72         u8 *vpd_command;
73         u8 *vpd_data;
74         int result = 0;
75
76         command = ibmasm_new_command(sp, INIT_BUFFER_SIZE);
77         if (command == NULL)
78                 return -ENOMEM;
79
80         header = (struct dot_command_header *)command->buffer;
81         header->type                = sp_write;
82         header->command_size        = 4;
83         header->data_size           = 16;
84         header->status              = 0;
85         header->reserved            = 0;
86
87         vpd_command = command->buffer + sizeof(struct dot_command_header);
88         vpd_command[0] = 0x4;
89         vpd_command[1] = 0x3;
90         vpd_command[2] = 0x5;
91         vpd_command[3] = 0xa;
92
93         vpd_data = vpd_command + header->command_size;
94         vpd_data[0] = 0;
95         strcat(vpd_data, IBMASM_DRIVER_VPD);
96         vpd_data[10] = 0;
97         vpd_data[15] = 0;
98         
99         ibmasm_exec_command(sp, command);
100         ibmasm_wait_for_response(command, IBMASM_CMD_TIMEOUT_NORMAL);
101
102         if (command->status != IBMASM_CMD_COMPLETE)
103                 result = -ENODEV;
104
105         command_put(command);
106
107         return result;
108 }
109
110 struct os_state_command {
111         struct dot_command_header       header;
112         unsigned char                   command[3];
113         unsigned char                   data;
114 };
115
116 /**
117  * send the 4.3.6 dot command (os state) to the service processor
118  * During driver init this function is called with os state "up".
119  * This causes the service processor to start sending heartbeats the
120  * driver.
121  * During driver exit the function is called with os state "down", 
122  * causing the service processor to stop the heartbeats.
123  */
124 int ibmasm_send_os_state(struct service_processor *sp, int os_state)
125 {
126         struct command *cmd;
127         struct os_state_command *os_state_cmd;
128         int result = 0;
129
130         cmd = ibmasm_new_command(sp, sizeof(struct os_state_command));
131         if (cmd == NULL)
132                 return -ENOMEM;
133
134         os_state_cmd = (struct os_state_command *)cmd->buffer;
135         os_state_cmd->header.type               = sp_write;
136         os_state_cmd->header.command_size       = 3;
137         os_state_cmd->header.data_size          = 1;
138         os_state_cmd->header.status             = 0;
139         os_state_cmd->command[0]                = 4;
140         os_state_cmd->command[1]                = 3;
141         os_state_cmd->command[2]                = 6;
142         os_state_cmd->data                      = os_state;
143
144         ibmasm_exec_command(sp, cmd);
145         ibmasm_wait_for_response(cmd, IBMASM_CMD_TIMEOUT_NORMAL);
146
147         if (cmd->status != IBMASM_CMD_COMPLETE)
148                 result = -ENODEV;
149
150         command_put(cmd);
151         return result;
152 }