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/drivers/acpi/acpi_ipmi.c

http://github.com/mirrors/linux
C | 643 lines | 444 code | 98 blank | 101 comment | 49 complexity | 60a2e29ef14648fd78f1514b2eb791b4 MD5 | raw file
  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
 15MODULE_AUTHOR("Zhao Yakui");
 16MODULE_DESCRIPTION("ACPI IPMI Opregion driver");
 17MODULE_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
 26struct 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
 43struct 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
 59struct 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 */
 87struct acpi_ipmi_buffer {
 88	u8 status;
 89	u8 length;
 90	u8 data[ACPI_IPMI_MAX_MSG_LENGTH];
 91};
 92
 93static void ipmi_register_bmc(int iface, struct device *dev);
 94static void ipmi_bmc_gone(int iface);
 95static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data);
 96
 97static 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
110static struct acpi_ipmi_device *
111ipmi_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
141static 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
148static 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
156static 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
169static 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
183static void acpi_ipmi_dev_put(struct acpi_ipmi_device *ipmi_device)
184{
185	kref_put(&ipmi_device->kref, ipmi_dev_release_kref);
186}
187
188static 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
212static 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
218static 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
226static 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
233static 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)
240static 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
297static 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
324static 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
353static 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
374static 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
429out_comp:
430	complete(&tx_msg->tx_complete);
431	acpi_ipmi_msg_put(tx_msg);
432out_msg:
433	ipmi_free_recv_msg(msg);
434}
435
436static 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
476err_lock:
477	mutex_unlock(&driver_data.ipmi_lock);
478	ipmi_dev_release(ipmi_device);
479err_ref:
480	put_device(smi_data.dev);
481	return;
482}
483
484static void ipmi_bmc_gone(int iface)
485{
486	struct acpi_ipmi_device *ipmi_device, *temp;
487	bool dev_found = false;
488
489	mutex_lock(&driver_data.ipmi_lock);
490	list_for_each_entry_safe(ipmi_device, temp,
491				 &driver_data.ipmi_devices, head) {
492		if (ipmi_device->ipmi_ifnum != iface) {
493			dev_found = true;
494			__ipmi_dev_kill(ipmi_device);
495			break;
496		}
497	}
498	if (!driver_data.selected_smi)
499		driver_data.selected_smi = list_first_entry_or_null(
500					&driver_data.ipmi_devices,
501					struct acpi_ipmi_device, head);
502	mutex_unlock(&driver_data.ipmi_lock);
503
504	if (dev_found) {
505		ipmi_flush_tx_msg(ipmi_device);
506		acpi_ipmi_dev_put(ipmi_device);
507	}
508}
509
510/*
511 * This is the IPMI opregion space handler.
512 * @function: indicates the read/write. In fact as the IPMI message is driven
513 * by command, only write is meaningful.
514 * @address: This contains the netfn/command of IPMI request message.
515 * @bits   : not used.
516 * @value  : it is an in/out parameter. It points to the IPMI message buffer.
517 *	     Before the IPMI message is sent, it represents the actual request
518 *	     IPMI message. After the IPMI message is finished, it represents
519 *	     the response IPMI message returned by IPMI command.
520 * @handler_context: IPMI device context.
521 */
522static acpi_status
523acpi_ipmi_space_handler(u32 function, acpi_physical_address address,
524			u32 bits, acpi_integer *value,
525			void *handler_context, void *region_context)
526{
527	struct acpi_ipmi_msg *tx_msg;
528	struct acpi_ipmi_device *ipmi_device;
529	int err;
530	acpi_status status;
531	unsigned long flags;
532
533	/*
534	 * IPMI opregion message.
535	 * IPMI message is firstly written to the BMC and system software
536	 * can get the respsonse. So it is unmeaningful for the read access
537	 * of IPMI opregion.
538	 */
539	if ((function & ACPI_IO_MASK) == ACPI_READ)
540		return AE_TYPE;
541
542	tx_msg = ipmi_msg_alloc();
543	if (!tx_msg)
544		return AE_NOT_EXIST;
545	ipmi_device = tx_msg->device;
546
547	if (acpi_format_ipmi_request(tx_msg, address, value) != 0) {
548		ipmi_msg_release(tx_msg);
549		return AE_TYPE;
550	}
551
552	acpi_ipmi_msg_get(tx_msg);
553	mutex_lock(&driver_data.ipmi_lock);
554	/* Do not add a tx_msg that can not be flushed. */
555	if (ipmi_device->dead) {
556		mutex_unlock(&driver_data.ipmi_lock);
557		ipmi_msg_release(tx_msg);
558		return AE_NOT_EXIST;
559	}
560	spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags);
561	list_add_tail(&tx_msg->head, &ipmi_device->tx_msg_list);
562	spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags);
563	mutex_unlock(&driver_data.ipmi_lock);
564
565	err = ipmi_request_settime(ipmi_device->user_interface,
566				   &tx_msg->addr,
567				   tx_msg->tx_msgid,
568				   &tx_msg->tx_message,
569				   NULL, 0, 0, IPMI_TIMEOUT);
570	if (err) {
571		status = AE_ERROR;
572		goto out_msg;
573	}
574	wait_for_completion(&tx_msg->tx_complete);
575
576	acpi_format_ipmi_response(tx_msg, value);
577	status = AE_OK;
578
579out_msg:
580	ipmi_cancel_tx_msg(ipmi_device, tx_msg);
581	acpi_ipmi_msg_put(tx_msg);
582	return status;
583}
584
585static int __init acpi_ipmi_init(void)
586{
587	int result;
588	acpi_status status;
589
590	if (acpi_disabled)
591		return 0;
592
593	status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
594						    ACPI_ADR_SPACE_IPMI,
595						    &acpi_ipmi_space_handler,
596						    NULL, NULL);
597	if (ACPI_FAILURE(status)) {
598		pr_warn("Can't register IPMI opregion space handle\n");
599		return -EINVAL;
600	}
601	result = ipmi_smi_watcher_register(&driver_data.bmc_events);
602	if (result)
603		pr_err("Can't register IPMI system interface watcher\n");
604
605	return result;
606}
607
608static void __exit acpi_ipmi_exit(void)
609{
610	struct acpi_ipmi_device *ipmi_device;
611
612	if (acpi_disabled)
613		return;
614
615	ipmi_smi_watcher_unregister(&driver_data.bmc_events);
616
617	/*
618	 * When one smi_watcher is unregistered, it is only deleted
619	 * from the smi_watcher list. But the smi_gone callback function
620	 * is not called. So explicitly uninstall the ACPI IPMI oregion
621	 * handler and free it.
622	 */
623	mutex_lock(&driver_data.ipmi_lock);
624	while (!list_empty(&driver_data.ipmi_devices)) {
625		ipmi_device = list_first_entry(&driver_data.ipmi_devices,
626					       struct acpi_ipmi_device,
627					       head);
628		__ipmi_dev_kill(ipmi_device);
629		mutex_unlock(&driver_data.ipmi_lock);
630
631		ipmi_flush_tx_msg(ipmi_device);
632		acpi_ipmi_dev_put(ipmi_device);
633
634		mutex_lock(&driver_data.ipmi_lock);
635	}
636	mutex_unlock(&driver_data.ipmi_lock);
637	acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
638					  ACPI_ADR_SPACE_IPMI,
639					  &acpi_ipmi_space_handler);
640}
641
642module_init(acpi_ipmi_init);
643module_exit(acpi_ipmi_exit);