1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * acpi_ipmi.c - ACPI IPMI opregion
4 *
5 * Copyright (C) 2010, 2013 Intel Corporation
6 * Author: Zhao Yakui <yakui.zhao@intel.com>
7 * Lv Zheng <lv.zheng@intel.com>
8 */
9
10 #include <linux/module.h>
11 #include <linux/acpi.h>
12 #include <linux/ipmi.h>
13 #include <linux/spinlock.h>
14
15 MODULE_AUTHOR("Zhao Yakui");
16 MODULE_DESCRIPTION("ACPI IPMI Opregion driver");
17 MODULE_LICENSE("GPL");
18
19 #define ACPI_IPMI_OK 0
20 #define ACPI_IPMI_TIMEOUT 0x10
21 #define ACPI_IPMI_UNKNOWN 0x07
22 /* the IPMI timeout is 5s */
23 #define IPMI_TIMEOUT (5000)
24 #define ACPI_IPMI_MAX_MSG_LENGTH 64
25
26 struct acpi_ipmi_device {
27 /* the device list attached to driver_data.ipmi_devices */
28 struct list_head head;
29
30 /* the IPMI request message list */
31 struct list_head tx_msg_list;
32
33 spinlock_t tx_msg_lock;
34 acpi_handle handle;
35 struct device *dev;
36 struct ipmi_user *user_interface;
37 int ipmi_ifnum; /* IPMI interface number */
38 long curr_msgid;
39 bool dead;
40 struct kref kref;
41 };
42
43 struct ipmi_driver_data {
44 struct list_head ipmi_devices;
45 struct ipmi_smi_watcher bmc_events;
46 const struct ipmi_user_hndl ipmi_hndlrs;
47 struct mutex ipmi_lock;
48
49 /*
50 * NOTE: IPMI System Interface Selection
51 * There is no system interface specified by the IPMI operation
52 * region access. We try to select one system interface with ACPI
53 * handle set. IPMI messages passed from the ACPI codes are sent
54 * to this selected global IPMI system interface.
55 */
56 struct acpi_ipmi_device *selected_smi;
57 };
58
59 struct acpi_ipmi_msg {
60 struct list_head head;
61
62 /*
63 * General speaking the addr type should be SI_ADDR_TYPE. And
64 * the addr channel should be BMC.
65 * In fact it can also be IPMB type. But we will have to
66 * parse it from the Netfn command buffer. It is so complex
67 * that it is skipped.
68 */
69 struct ipmi_addr addr;
70 long tx_msgid;
71
72 /* it is used to track whether the IPMI message is finished */
73 struct completion tx_complete;
74
75 struct kernel_ipmi_msg tx_message;
76 int msg_done;
77
78 /* tx/rx data . And copy it from/to ACPI object buffer */
79 u8 data[ACPI_IPMI_MAX_MSG_LENGTH];
80 u8 rx_len;
81
82 struct acpi_ipmi_device *device;
83 struct kref kref;
84 };
85
86 /* IPMI request/response buffer per ACPI 4.0, sec 5.5.2.4.3.2 */
87 struct acpi_ipmi_buffer {
88 u8 status;
89 u8 length;
90 u8 data[ACPI_IPMI_MAX_MSG_LENGTH];
91 };
92
93 static void ipmi_register_bmc(int iface, struct device *dev);
94 static void ipmi_bmc_gone(int iface);
95 static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data);
96
97 static struct ipmi_driver_data driver_data = {
98 .ipmi_devices = LIST_HEAD_INIT(driver_data.ipmi_devices),
99 .bmc_events = {
100 .owner = THIS_MODULE,
101 .new_smi = ipmi_register_bmc,
102 .smi_gone = ipmi_bmc_gone,
103 },
104 .ipmi_hndlrs = {
105 .ipmi_recv_hndl = ipmi_msg_handler,
106 },
107 .ipmi_lock = __MUTEX_INITIALIZER(driver_data.ipmi_lock)
108 };
109
110 static struct acpi_ipmi_device *
ipmi_dev_alloc(int iface,struct device * dev,acpi_handle handle)111 ipmi_dev_alloc(int iface, struct device *dev, acpi_handle handle)
112 {
113 struct acpi_ipmi_device *ipmi_device;
114 int err;
115 struct ipmi_user *user;
116
117 ipmi_device = kzalloc(sizeof(*ipmi_device), GFP_KERNEL);
118 if (!ipmi_device)
119 return NULL;
120
121 kref_init(&ipmi_device->kref);
122 INIT_LIST_HEAD(&ipmi_device->head);
123 INIT_LIST_HEAD(&ipmi_device->tx_msg_list);
124 spin_lock_init(&ipmi_device->tx_msg_lock);
125 ipmi_device->handle = handle;
126 ipmi_device->dev = get_device(dev);
127 ipmi_device->ipmi_ifnum = iface;
128
129 err = ipmi_create_user(iface, &driver_data.ipmi_hndlrs,
130 ipmi_device, &user);
131 if (err) {
132 put_device(dev);
133 kfree(ipmi_device);
134 return NULL;
135 }
136 ipmi_device->user_interface = user;
137
138 return ipmi_device;
139 }
140
ipmi_dev_release(struct acpi_ipmi_device * ipmi_device)141 static void ipmi_dev_release(struct acpi_ipmi_device *ipmi_device)
142 {
143 ipmi_destroy_user(ipmi_device->user_interface);
144 put_device(ipmi_device->dev);
145 kfree(ipmi_device);
146 }
147
ipmi_dev_release_kref(struct kref * kref)148 static void ipmi_dev_release_kref(struct kref *kref)
149 {
150 struct acpi_ipmi_device *ipmi =
151 container_of(kref, struct acpi_ipmi_device, kref);
152
153 ipmi_dev_release(ipmi);
154 }
155
__ipmi_dev_kill(struct acpi_ipmi_device * ipmi_device)156 static void __ipmi_dev_kill(struct acpi_ipmi_device *ipmi_device)
157 {
158 list_del(&ipmi_device->head);
159 if (driver_data.selected_smi == ipmi_device)
160 driver_data.selected_smi = NULL;
161
162 /*
163 * Always setting dead flag after deleting from the list or
164 * list_for_each_entry() codes must get changed.
165 */
166 ipmi_device->dead = true;
167 }
168
acpi_ipmi_dev_get(void)169 static struct acpi_ipmi_device *acpi_ipmi_dev_get(void)
170 {
171 struct acpi_ipmi_device *ipmi_device = NULL;
172
173 mutex_lock(&driver_data.ipmi_lock);
174 if (driver_data.selected_smi) {
175 ipmi_device = driver_data.selected_smi;
176 kref_get(&ipmi_device->kref);
177 }
178 mutex_unlock(&driver_data.ipmi_lock);
179
180 return ipmi_device;
181 }
182
acpi_ipmi_dev_put(struct acpi_ipmi_device * ipmi_device)183 static void acpi_ipmi_dev_put(struct acpi_ipmi_device *ipmi_device)
184 {
185 kref_put(&ipmi_device->kref, ipmi_dev_release_kref);
186 }
187
ipmi_msg_alloc(void)188 static struct acpi_ipmi_msg *ipmi_msg_alloc(void)
189 {
190 struct acpi_ipmi_device *ipmi;
191 struct acpi_ipmi_msg *ipmi_msg;
192
193 ipmi = acpi_ipmi_dev_get();
194 if (!ipmi)
195 return NULL;
196
197 ipmi_msg = kzalloc(sizeof(struct acpi_ipmi_msg), GFP_KERNEL);
198 if (!ipmi_msg) {
199 acpi_ipmi_dev_put(ipmi);
200 return NULL;
201 }
202
203 kref_init(&ipmi_msg->kref);
204 init_completion(&ipmi_msg->tx_complete);
205 INIT_LIST_HEAD(&ipmi_msg->head);
206 ipmi_msg->device = ipmi;
207 ipmi_msg->msg_done = ACPI_IPMI_UNKNOWN;
208
209 return ipmi_msg;
210 }
211
ipmi_msg_release(struct acpi_ipmi_msg * tx_msg)212 static void ipmi_msg_release(struct acpi_ipmi_msg *tx_msg)
213 {
214 acpi_ipmi_dev_put(tx_msg->device);
215 kfree(tx_msg);
216 }
217
ipmi_msg_release_kref(struct kref * kref)218 static void ipmi_msg_release_kref(struct kref *kref)
219 {
220 struct acpi_ipmi_msg *tx_msg =
221 container_of(kref, struct acpi_ipmi_msg, kref);
222
223 ipmi_msg_release(tx_msg);
224 }
225
acpi_ipmi_msg_get(struct acpi_ipmi_msg * tx_msg)226 static struct acpi_ipmi_msg *acpi_ipmi_msg_get(struct acpi_ipmi_msg *tx_msg)
227 {
228 kref_get(&tx_msg->kref);
229
230 return tx_msg;
231 }
232
acpi_ipmi_msg_put(struct acpi_ipmi_msg * tx_msg)233 static void acpi_ipmi_msg_put(struct acpi_ipmi_msg *tx_msg)
234 {
235 kref_put(&tx_msg->kref, ipmi_msg_release_kref);
236 }
237
238 #define IPMI_OP_RGN_NETFN(offset) ((offset >> 8) & 0xff)
239 #define IPMI_OP_RGN_CMD(offset) (offset & 0xff)
acpi_format_ipmi_request(struct acpi_ipmi_msg * tx_msg,acpi_physical_address address,acpi_integer * value)240 static int acpi_format_ipmi_request(struct acpi_ipmi_msg *tx_msg,
241 acpi_physical_address address,
242 acpi_integer *value)
243 {
244 struct kernel_ipmi_msg *msg;
245 struct acpi_ipmi_buffer *buffer;
246 struct acpi_ipmi_device *device;
247 unsigned long flags;
248
249 msg = &tx_msg->tx_message;
250
251 /*
252 * IPMI network function and command are encoded in the address
253 * within the IPMI OpRegion; see ACPI 4.0, sec 5.5.2.4.3.
254 */
255 msg->netfn = IPMI_OP_RGN_NETFN(address);
256 msg->cmd = IPMI_OP_RGN_CMD(address);
257 msg->data = tx_msg->data;
258
259 /*
260 * value is the parameter passed by the IPMI opregion space handler.
261 * It points to the IPMI request message buffer
262 */
263 buffer = (struct acpi_ipmi_buffer *)value;
264
265 /* copy the tx message data */
266 if (buffer->length > ACPI_IPMI_MAX_MSG_LENGTH) {
267 dev_WARN_ONCE(tx_msg->device->dev, true,
268 "Unexpected request (msg len %d).\n",
269 buffer->length);
270 return -EINVAL;
271 }
272 msg->data_len = buffer->length;
273 memcpy(tx_msg->data, buffer->data, msg->data_len);
274
275 /*
276 * now the default type is SYSTEM_INTERFACE and channel type is BMC.
277 * If the netfn is APP_REQUEST and the cmd is SEND_MESSAGE,
278 * the addr type should be changed to IPMB. Then we will have to parse
279 * the IPMI request message buffer to get the IPMB address.
280 * If so, please fix me.
281 */
282 tx_msg->addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
283 tx_msg->addr.channel = IPMI_BMC_CHANNEL;
284 tx_msg->addr.data[0] = 0;
285
286 /* Get the msgid */
287 device = tx_msg->device;
288
289 spin_lock_irqsave(&device->tx_msg_lock, flags);
290 device->curr_msgid++;
291 tx_msg->tx_msgid = device->curr_msgid;
292 spin_unlock_irqrestore(&device->tx_msg_lock, flags);
293
294 return 0;
295 }
296
acpi_format_ipmi_response(struct acpi_ipmi_msg * msg,acpi_integer * value)297 static void acpi_format_ipmi_response(struct acpi_ipmi_msg *msg,
298 acpi_integer *value)
299 {
300 struct acpi_ipmi_buffer *buffer;
301
302 /*
303 * value is also used as output parameter. It represents the response
304 * IPMI message returned by IPMI command.
305 */
306 buffer = (struct acpi_ipmi_buffer *)value;
307
308 /*
309 * If the flag of msg_done is not set, it means that the IPMI command is
310 * not executed correctly.
311 */
312 buffer->status = msg->msg_done;
313 if (msg->msg_done != ACPI_IPMI_OK)
314 return;
315
316 /*
317 * If the IPMI response message is obtained correctly, the status code
318 * will be ACPI_IPMI_OK
319 */
320 buffer->length = msg->rx_len;
321 memcpy(buffer->data, msg->data, msg->rx_len);
322 }
323
ipmi_flush_tx_msg(struct acpi_ipmi_device * ipmi)324 static void ipmi_flush_tx_msg(struct acpi_ipmi_device *ipmi)
325 {
326 struct acpi_ipmi_msg *tx_msg;
327 unsigned long flags;
328
329 /*
330 * NOTE: On-going ipmi_recv_msg
331 * ipmi_msg_handler() may still be invoked by ipmi_si after
332 * flushing. But it is safe to do a fast flushing on module_exit()
333 * without waiting for all ipmi_recv_msg(s) to complete from
334 * ipmi_msg_handler() as it is ensured by ipmi_si that all
335 * ipmi_recv_msg(s) are freed after invoking ipmi_destroy_user().
336 */
337 spin_lock_irqsave(&ipmi->tx_msg_lock, flags);
338 while (!list_empty(&ipmi->tx_msg_list)) {
339 tx_msg = list_first_entry(&ipmi->tx_msg_list,
340 struct acpi_ipmi_msg,
341 head);
342 list_del(&tx_msg->head);
343 spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags);
344
345 /* wake up the sleep thread on the Tx msg */
346 complete(&tx_msg->tx_complete);
347 acpi_ipmi_msg_put(tx_msg);
348 spin_lock_irqsave(&ipmi->tx_msg_lock, flags);
349 }
350 spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags);
351 }
352
ipmi_cancel_tx_msg(struct acpi_ipmi_device * ipmi,struct acpi_ipmi_msg * msg)353 static void ipmi_cancel_tx_msg(struct acpi_ipmi_device *ipmi,
354 struct acpi_ipmi_msg *msg)
355 {
356 struct acpi_ipmi_msg *tx_msg, *temp;
357 bool msg_found = false;
358 unsigned long flags;
359
360 spin_lock_irqsave(&ipmi->tx_msg_lock, flags);
361 list_for_each_entry_safe(tx_msg, temp, &ipmi->tx_msg_list, head) {
362 if (msg == tx_msg) {
363 msg_found = true;
364 list_del(&tx_msg->head);
365 break;
366 }
367 }
368 spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags);
369
370 if (msg_found)
371 acpi_ipmi_msg_put(tx_msg);
372 }
373
ipmi_msg_handler(struct ipmi_recv_msg * msg,void * user_msg_data)374 static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data)
375 {
376 struct acpi_ipmi_device *ipmi_device = user_msg_data;
377 bool msg_found = false;
378 struct acpi_ipmi_msg *tx_msg, *temp;
379 struct device *dev = ipmi_device->dev;
380 unsigned long flags;
381
382 if (msg->user != ipmi_device->user_interface) {
383 dev_warn(dev,
384 "Unexpected response is returned. returned user %p, expected user %p\n",
385 msg->user, ipmi_device->user_interface);
386 goto out_msg;
387 }
388
389 spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags);
390 list_for_each_entry_safe(tx_msg, temp, &ipmi_device->tx_msg_list, head) {
391 if (msg->msgid == tx_msg->tx_msgid) {
392 msg_found = true;
393 list_del(&tx_msg->head);
394 break;
395 }
396 }
397 spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags);
398
399 if (!msg_found) {
400 dev_warn(dev,
401 "Unexpected response (msg id %ld) is returned.\n",
402 msg->msgid);
403 goto out_msg;
404 }
405
406 /* copy the response data to Rx_data buffer */
407 if (msg->msg.data_len > ACPI_IPMI_MAX_MSG_LENGTH) {
408 dev_WARN_ONCE(dev, true,
409 "Unexpected response (msg len %d).\n",
410 msg->msg.data_len);
411 goto out_comp;
412 }
413
414 /* response msg is an error msg */
415 msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
416 if (msg->recv_type == IPMI_RESPONSE_RECV_TYPE &&
417 msg->msg.data_len == 1) {
418 if (msg->msg.data[0] == IPMI_TIMEOUT_COMPLETION_CODE) {
419 dev_dbg_once(dev, "Unexpected response (timeout).\n");
420 tx_msg->msg_done = ACPI_IPMI_TIMEOUT;
421 }
422 goto out_comp;
423 }
424
425 tx_msg->rx_len = msg->msg.data_len;
426 memcpy(tx_msg->data, msg->msg.data, tx_msg->rx_len);
427 tx_msg->msg_done = ACPI_IPMI_OK;
428
429 out_comp:
430 complete(&tx_msg->tx_complete);
431 acpi_ipmi_msg_put(tx_msg);
432 out_msg:
433 ipmi_free_recv_msg(msg);
434 }
435
ipmi_register_bmc(int iface,struct device * dev)436 static void ipmi_register_bmc(int iface, struct device *dev)
437 {
438 struct acpi_ipmi_device *ipmi_device, *temp;
439 int err;
440 struct ipmi_smi_info smi_data;
441 acpi_handle handle;
442
443 err = ipmi_get_smi_info(iface, &smi_data);
444 if (err)
445 return;
446
447 if (smi_data.addr_src != SI_ACPI)
448 goto err_ref;
449 handle = smi_data.addr_info.acpi_info.acpi_handle;
450 if (!handle)
451 goto err_ref;
452
453 ipmi_device = ipmi_dev_alloc(iface, smi_data.dev, handle);
454 if (!ipmi_device) {
455 dev_warn(smi_data.dev, "Can't create IPMI user interface\n");
456 goto err_ref;
457 }
458
459 mutex_lock(&driver_data.ipmi_lock);
460 list_for_each_entry(temp, &driver_data.ipmi_devices, head) {
461 /*
462 * if the corresponding ACPI handle is already added
463 * to the device list, don't add it again.
464 */
465 if (temp->handle == handle)
466 goto err_lock;
467 }
468 if (!driver_data.selected_smi)
469 driver_data.selected_smi = ipmi_device;
470 list_add_tail(&ipmi_device->head, &driver_data.ipmi_devices);
471 mutex_unlock(&driver_data.ipmi_lock);
472
473 put_device(smi_data.dev);
474 return;
475
476 err_lock:
477 mutex_unlock(&driver_data.ipmi_lock);
478 ipmi_dev_release(ipmi_device);
479 err_ref:
480 put_device(smi_data.dev);
481 }
482
ipmi_bmc_gone(int iface)483 static void ipmi_bmc_gone(int iface)
484 {
485 struct acpi_ipmi_device *ipmi_device, *temp;
486 bool dev_found = false;
487
488 mutex_lock(&driver_data.ipmi_lock);
489 list_for_each_entry_safe(ipmi_device, temp,
490 &driver_data.ipmi_devices, head) {
491 if (ipmi_device->ipmi_ifnum != iface) {
492 dev_found = true;
493 __ipmi_dev_kill(ipmi_device);
494 break;
495 }
496 }
497 if (!driver_data.selected_smi)
498 driver_data.selected_smi = list_first_entry_or_null(
499 &driver_data.ipmi_devices,
500 struct acpi_ipmi_device, head);
501 mutex_unlock(&driver_data.ipmi_lock);
502
503 if (dev_found) {
504 ipmi_flush_tx_msg(ipmi_device);
505 acpi_ipmi_dev_put(ipmi_device);
506 }
507 }
508
509 /*
510 * This is the IPMI opregion space handler.
511 * @function: indicates the read/write. In fact as the IPMI message is driven
512 * by command, only write is meaningful.
513 * @address: This contains the netfn/command of IPMI request message.
514 * @bits : not used.
515 * @value : it is an in/out parameter. It points to the IPMI message buffer.
516 * Before the IPMI message is sent, it represents the actual request
517 * IPMI message. After the IPMI message is finished, it represents
518 * the response IPMI message returned by IPMI command.
519 * @handler_context: IPMI device context.
520 */
521 static acpi_status
acpi_ipmi_space_handler(u32 function,acpi_physical_address address,u32 bits,acpi_integer * value,void * handler_context,void * region_context)522 acpi_ipmi_space_handler(u32 function, acpi_physical_address address,
523 u32 bits, acpi_integer *value,
524 void *handler_context, void *region_context)
525 {
526 struct acpi_ipmi_msg *tx_msg;
527 struct acpi_ipmi_device *ipmi_device;
528 int err;
529 acpi_status status;
530 unsigned long flags;
531
532 /*
533 * IPMI opregion message.
534 * IPMI message is firstly written to the BMC and system software
535 * can get the respsonse. So it is unmeaningful for the read access
536 * of IPMI opregion.
537 */
538 if ((function & ACPI_IO_MASK) == ACPI_READ)
539 return AE_TYPE;
540
541 tx_msg = ipmi_msg_alloc();
542 if (!tx_msg)
543 return AE_NOT_EXIST;
544 ipmi_device = tx_msg->device;
545
546 if (acpi_format_ipmi_request(tx_msg, address, value) != 0) {
547 ipmi_msg_release(tx_msg);
548 return AE_TYPE;
549 }
550
551 acpi_ipmi_msg_get(tx_msg);
552 mutex_lock(&driver_data.ipmi_lock);
553 /* Do not add a tx_msg that can not be flushed. */
554 if (ipmi_device->dead) {
555 mutex_unlock(&driver_data.ipmi_lock);
556 ipmi_msg_release(tx_msg);
557 return AE_NOT_EXIST;
558 }
559 spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags);
560 list_add_tail(&tx_msg->head, &ipmi_device->tx_msg_list);
561 spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags);
562 mutex_unlock(&driver_data.ipmi_lock);
563
564 err = ipmi_request_settime(ipmi_device->user_interface,
565 &tx_msg->addr,
566 tx_msg->tx_msgid,
567 &tx_msg->tx_message,
568 NULL, 0, 0, IPMI_TIMEOUT);
569 if (err) {
570 status = AE_ERROR;
571 goto out_msg;
572 }
573 wait_for_completion(&tx_msg->tx_complete);
574
575 acpi_format_ipmi_response(tx_msg, value);
576 status = AE_OK;
577
578 out_msg:
579 ipmi_cancel_tx_msg(ipmi_device, tx_msg);
580 acpi_ipmi_msg_put(tx_msg);
581 return status;
582 }
583
acpi_ipmi_init(void)584 static int __init acpi_ipmi_init(void)
585 {
586 int result;
587 acpi_status status;
588
589 if (acpi_disabled)
590 return 0;
591
592 status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
593 ACPI_ADR_SPACE_IPMI,
594 &acpi_ipmi_space_handler,
595 NULL, NULL);
596 if (ACPI_FAILURE(status)) {
597 pr_warn("Can't register IPMI opregion space handle\n");
598 return -EINVAL;
599 }
600
601 result = ipmi_smi_watcher_register(&driver_data.bmc_events);
602 if (result) {
603 acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
604 ACPI_ADR_SPACE_IPMI,
605 &acpi_ipmi_space_handler);
606 pr_err("Can't register IPMI system interface watcher\n");
607 }
608
609 return result;
610 }
611
acpi_ipmi_exit(void)612 static void __exit acpi_ipmi_exit(void)
613 {
614 struct acpi_ipmi_device *ipmi_device;
615
616 if (acpi_disabled)
617 return;
618
619 ipmi_smi_watcher_unregister(&driver_data.bmc_events);
620
621 /*
622 * When one smi_watcher is unregistered, it is only deleted
623 * from the smi_watcher list. But the smi_gone callback function
624 * is not called. So explicitly uninstall the ACPI IPMI oregion
625 * handler and free it.
626 */
627 mutex_lock(&driver_data.ipmi_lock);
628 while (!list_empty(&driver_data.ipmi_devices)) {
629 ipmi_device = list_first_entry(&driver_data.ipmi_devices,
630 struct acpi_ipmi_device,
631 head);
632 __ipmi_dev_kill(ipmi_device);
633 mutex_unlock(&driver_data.ipmi_lock);
634
635 ipmi_flush_tx_msg(ipmi_device);
636 acpi_ipmi_dev_put(ipmi_device);
637
638 mutex_lock(&driver_data.ipmi_lock);
639 }
640 mutex_unlock(&driver_data.ipmi_lock);
641 acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
642 ACPI_ADR_SPACE_IPMI,
643 &acpi_ipmi_space_handler);
644 }
645
646 module_init(acpi_ipmi_init);
647 module_exit(acpi_ipmi_exit);
648