xref: /linux/drivers/char/ipmi/ipmi_msghandler.c (revision 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * ipmi_msghandler.c
4  *
5  * Incoming and outgoing message routing for an IPMI interface.
6  *
7  * Author: MontaVista Software, Inc.
8  *         Corey Minyard <minyard@mvista.com>
9  *         source@mvista.com
10  *
11  * Copyright 2002 MontaVista Software Inc.
12  */
13 
14 #define pr_fmt(fmt) "IPMI message handler: " fmt
15 #define dev_fmt(fmt) pr_fmt(fmt)
16 
17 #include <linux/module.h>
18 #include <linux/errno.h>
19 #include <linux/panic_notifier.h>
20 #include <linux/poll.h>
21 #include <linux/sched.h>
22 #include <linux/seq_file.h>
23 #include <linux/spinlock.h>
24 #include <linux/mutex.h>
25 #include <linux/slab.h>
26 #include <linux/ipmi.h>
27 #include <linux/ipmi_smi.h>
28 #include <linux/notifier.h>
29 #include <linux/init.h>
30 #include <linux/rcupdate.h>
31 #include <linux/interrupt.h>
32 #include <linux/moduleparam.h>
33 #include <linux/workqueue.h>
34 #include <linux/uuid.h>
35 #include <linux/nospec.h>
36 #include <linux/vmalloc.h>
37 #include <linux/delay.h>
38 
39 #define IPMI_DRIVER_VERSION "39.2"
40 
41 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(struct ipmi_user *user);
42 static void ipmi_set_recv_msg_user(struct ipmi_recv_msg *msg,
43 				   struct ipmi_user *user);
44 static int ipmi_init_msghandler(void);
45 static void smi_work(struct work_struct *t);
46 static void handle_new_recv_msgs(struct ipmi_smi *intf);
47 static void need_waiter(struct ipmi_smi *intf);
48 static int handle_one_recv_msg(struct ipmi_smi *intf,
49 			       struct ipmi_smi_msg *msg);
50 static void intf_free(struct kref *ref);
51 
52 static bool initialized;
53 static bool drvregistered;
54 
55 static struct timer_list ipmi_timer;
56 
57 /* Numbers in this enumerator should be mapped to ipmi_panic_event_str */
58 enum ipmi_panic_event_op {
59 	IPMI_SEND_PANIC_EVENT_NONE,
60 	IPMI_SEND_PANIC_EVENT,
61 	IPMI_SEND_PANIC_EVENT_STRING,
62 	IPMI_SEND_PANIC_EVENT_MAX
63 };
64 
65 /* Indices in this array should be mapped to enum ipmi_panic_event_op */
66 static const char *const ipmi_panic_event_str[] = { "none", "event", "string", NULL };
67 
68 #ifdef CONFIG_IPMI_PANIC_STRING
69 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT_STRING
70 #elif defined(CONFIG_IPMI_PANIC_EVENT)
71 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT
72 #else
73 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT_NONE
74 #endif
75 
76 static enum ipmi_panic_event_op ipmi_send_panic_event = IPMI_PANIC_DEFAULT;
77 
78 static int panic_op_write_handler(const char *val,
79 				  const struct kernel_param *kp)
80 {
81 	char valcp[16];
82 	int e;
83 
84 	strscpy(valcp, val, sizeof(valcp));
85 	e = match_string(ipmi_panic_event_str, -1, strstrip(valcp));
86 	if (e < 0)
87 		return e;
88 
89 	ipmi_send_panic_event = e;
90 	return 0;
91 }
92 
93 static int panic_op_read_handler(char *buffer, const struct kernel_param *kp)
94 {
95 	const char *event_str;
96 
97 	if (ipmi_send_panic_event >= IPMI_SEND_PANIC_EVENT_MAX)
98 		event_str = "???";
99 	else
100 		event_str = ipmi_panic_event_str[ipmi_send_panic_event];
101 
102 	return sprintf(buffer, "%s\n", event_str);
103 }
104 
105 static const struct kernel_param_ops panic_op_ops = {
106 	.set = panic_op_write_handler,
107 	.get = panic_op_read_handler
108 };
109 module_param_cb(panic_op, &panic_op_ops, NULL, 0600);
110 MODULE_PARM_DESC(panic_op, "Sets if the IPMI driver will attempt to store panic information in the event log in the event of a panic.  Set to 'none' for no, 'event' for a single event, or 'string' for a generic event and the panic string in IPMI OEM events.");
111 
112 
113 #define MAX_EVENTS_IN_QUEUE	25
114 
115 /* Remain in auto-maintenance mode for this amount of time (in ms). */
116 static unsigned long maintenance_mode_timeout_ms = 30000;
117 module_param(maintenance_mode_timeout_ms, ulong, 0644);
118 MODULE_PARM_DESC(maintenance_mode_timeout_ms,
119 		 "The time (milliseconds) after the last maintenance message that the connection stays in maintenance mode.");
120 
121 /*
122  * Don't let a message sit in a queue forever, always time it with at lest
123  * the max message timer.  This is in milliseconds.
124  */
125 #define MAX_MSG_TIMEOUT		60000
126 
127 /*
128  * Timeout times below are in milliseconds, and are done off a 1
129  * second timer.  So setting the value to 1000 would mean anything
130  * between 0 and 1000ms.  So really the only reasonable minimum
131  * setting it 2000ms, which is between 1 and 2 seconds.
132  */
133 
134 /* The default timeout for message retries. */
135 static unsigned long default_retry_ms = 2000;
136 module_param(default_retry_ms, ulong, 0644);
137 MODULE_PARM_DESC(default_retry_ms,
138 		 "The time (milliseconds) between retry sends");
139 
140 /* The default timeout for maintenance mode message retries. */
141 static unsigned long default_maintenance_retry_ms = 3000;
142 module_param(default_maintenance_retry_ms, ulong, 0644);
143 MODULE_PARM_DESC(default_maintenance_retry_ms,
144 		 "The time (milliseconds) between retry sends in maintenance mode");
145 
146 /* The default maximum number of retries */
147 static unsigned int default_max_retries = 4;
148 module_param(default_max_retries, uint, 0644);
149 MODULE_PARM_DESC(default_max_retries,
150 		 "The time (milliseconds) between retry sends in maintenance mode");
151 
152 /* The default maximum number of users that may register. */
153 static unsigned int max_users = 30;
154 module_param(max_users, uint, 0644);
155 MODULE_PARM_DESC(max_users,
156 		 "The most users that may use the IPMI stack at one time.");
157 
158 /* The default maximum number of message a user may have outstanding. */
159 static unsigned int max_msgs_per_user = 100;
160 module_param(max_msgs_per_user, uint, 0644);
161 MODULE_PARM_DESC(max_msgs_per_user,
162 		 "The most message a user may have outstanding.");
163 
164 /* Call every ~1000 ms. */
165 #define IPMI_TIMEOUT_TIME	1000
166 
167 /* How many jiffies does it take to get to the timeout time. */
168 #define IPMI_TIMEOUT_JIFFIES	((IPMI_TIMEOUT_TIME * HZ) / 1000)
169 
170 /*
171  * Request events from the queue every second (this is the number of
172  * IPMI_TIMEOUT_TIMES between event requests).  Hopefully, in the
173  * future, IPMI will add a way to know immediately if an event is in
174  * the queue and this silliness can go away.
175  */
176 #define IPMI_REQUEST_EV_TIME	(1000 / (IPMI_TIMEOUT_TIME))
177 
178 /* How long should we cache dynamic device IDs? */
179 #define IPMI_DYN_DEV_ID_EXPIRY	(10 * HZ)
180 
181 /*
182  * The main "user" data structure.
183  */
184 struct ipmi_user {
185 	struct list_head link;
186 
187 	struct kref refcount;
188 	refcount_t destroyed;
189 
190 	/* The upper layer that handles receive messages. */
191 	const struct ipmi_user_hndl *handler;
192 	void             *handler_data;
193 
194 	/* The interface this user is bound to. */
195 	struct ipmi_smi *intf;
196 
197 	/* Does this interface receive IPMI events? */
198 	bool gets_events;
199 
200 	atomic_t nr_msgs;
201 };
202 
203 struct cmd_rcvr {
204 	struct list_head link;
205 
206 	struct ipmi_user *user;
207 	unsigned char netfn;
208 	unsigned char cmd;
209 	unsigned int  chans;
210 
211 	/*
212 	 * This is used to form a linked lised during mass deletion.
213 	 * Since this is in an RCU list, we cannot use the link above
214 	 * or change any data until the RCU period completes.  So we
215 	 * use this next variable during mass deletion so we can have
216 	 * a list and don't have to wait and restart the search on
217 	 * every individual deletion of a command.
218 	 */
219 	struct cmd_rcvr *next;
220 };
221 
222 struct seq_table {
223 	unsigned int         inuse : 1;
224 	unsigned int         broadcast : 1;
225 
226 	unsigned long        timeout;
227 	unsigned long        orig_timeout;
228 	unsigned int         retries_left;
229 
230 	/*
231 	 * To verify on an incoming send message response that this is
232 	 * the message that the response is for, we keep a sequence id
233 	 * and increment it every time we send a message.
234 	 */
235 	long                 seqid;
236 
237 	/*
238 	 * This is held so we can properly respond to the message on a
239 	 * timeout, and it is used to hold the temporary data for
240 	 * retransmission, too.
241 	 */
242 	struct ipmi_recv_msg *recv_msg;
243 };
244 
245 /*
246  * Store the information in a msgid (long) to allow us to find a
247  * sequence table entry from the msgid.
248  */
249 #define STORE_SEQ_IN_MSGID(seq, seqid) \
250 	((((seq) & 0x3f) << 26) | ((seqid) & 0x3ffffff))
251 
252 #define GET_SEQ_FROM_MSGID(msgid, seq, seqid) \
253 	do {								\
254 		seq = (((msgid) >> 26) & 0x3f);				\
255 		seqid = ((msgid) & 0x3ffffff);				\
256 	} while (0)
257 
258 #define NEXT_SEQID(seqid) (((seqid) + 1) & 0x3ffffff)
259 
260 #define IPMI_MAX_CHANNELS       16
261 struct ipmi_channel {
262 	unsigned char medium;
263 	unsigned char protocol;
264 };
265 
266 struct ipmi_channel_set {
267 	struct ipmi_channel c[IPMI_MAX_CHANNELS];
268 };
269 
270 struct ipmi_my_addrinfo {
271 	/*
272 	 * My slave address.  This is initialized to IPMI_BMC_SLAVE_ADDR,
273 	 * but may be changed by the user.
274 	 */
275 	unsigned char address;
276 
277 	/*
278 	 * My LUN.  This should generally stay the SMS LUN, but just in
279 	 * case...
280 	 */
281 	unsigned char lun;
282 };
283 
284 /*
285  * Note that the product id, manufacturer id, guid, and device id are
286  * immutable in this structure, so dyn_mutex is not required for
287  * accessing those.  If those change on a BMC, a new BMC is allocated.
288  */
289 struct bmc_device {
290 	struct platform_device pdev;
291 	struct list_head       intfs; /* Interfaces on this BMC. */
292 	struct ipmi_device_id  id;
293 	struct ipmi_device_id  fetch_id;
294 	int                    dyn_id_set;
295 	unsigned long          dyn_id_expiry;
296 	struct mutex           dyn_mutex; /* Protects id, intfs, & dyn* */
297 	guid_t                 guid;
298 	guid_t                 fetch_guid;
299 	int                    dyn_guid_set;
300 	struct kref	       usecount;
301 	struct work_struct     remove_work;
302 	unsigned char	       cc; /* completion code */
303 };
304 #define to_bmc_device(x) container_of((x), struct bmc_device, pdev.dev)
305 
306 static struct workqueue_struct *bmc_remove_work_wq;
307 
308 static int bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
309 			     struct ipmi_device_id *id,
310 			     bool *guid_set, guid_t *guid);
311 
312 /*
313  * Various statistics for IPMI, these index stats[] in the ipmi_smi
314  * structure.
315  */
316 enum ipmi_stat_indexes {
317 	/* Commands we got from the user that were invalid. */
318 	IPMI_STAT_sent_invalid_commands = 0,
319 
320 	/* Commands we sent to the MC. */
321 	IPMI_STAT_sent_local_commands,
322 
323 	/* Responses from the MC that were delivered to a user. */
324 	IPMI_STAT_handled_local_responses,
325 
326 	/* Responses from the MC that were not delivered to a user. */
327 	IPMI_STAT_unhandled_local_responses,
328 
329 	/* Commands we sent out to the IPMB bus. */
330 	IPMI_STAT_sent_ipmb_commands,
331 
332 	/* Commands sent on the IPMB that had errors on the SEND CMD */
333 	IPMI_STAT_sent_ipmb_command_errs,
334 
335 	/* Each retransmit increments this count. */
336 	IPMI_STAT_retransmitted_ipmb_commands,
337 
338 	/*
339 	 * When a message times out (runs out of retransmits) this is
340 	 * incremented.
341 	 */
342 	IPMI_STAT_timed_out_ipmb_commands,
343 
344 	/*
345 	 * This is like above, but for broadcasts.  Broadcasts are
346 	 * *not* included in the above count (they are expected to
347 	 * time out).
348 	 */
349 	IPMI_STAT_timed_out_ipmb_broadcasts,
350 
351 	/* Responses I have sent to the IPMB bus. */
352 	IPMI_STAT_sent_ipmb_responses,
353 
354 	/* The response was delivered to the user. */
355 	IPMI_STAT_handled_ipmb_responses,
356 
357 	/* The response had invalid data in it. */
358 	IPMI_STAT_invalid_ipmb_responses,
359 
360 	/* The response didn't have anyone waiting for it. */
361 	IPMI_STAT_unhandled_ipmb_responses,
362 
363 	/* Commands we sent out to the IPMB bus. */
364 	IPMI_STAT_sent_lan_commands,
365 
366 	/* Commands sent on the IPMB that had errors on the SEND CMD */
367 	IPMI_STAT_sent_lan_command_errs,
368 
369 	/* Each retransmit increments this count. */
370 	IPMI_STAT_retransmitted_lan_commands,
371 
372 	/*
373 	 * When a message times out (runs out of retransmits) this is
374 	 * incremented.
375 	 */
376 	IPMI_STAT_timed_out_lan_commands,
377 
378 	/* Responses I have sent to the IPMB bus. */
379 	IPMI_STAT_sent_lan_responses,
380 
381 	/* The response was delivered to the user. */
382 	IPMI_STAT_handled_lan_responses,
383 
384 	/* The response had invalid data in it. */
385 	IPMI_STAT_invalid_lan_responses,
386 
387 	/* The response didn't have anyone waiting for it. */
388 	IPMI_STAT_unhandled_lan_responses,
389 
390 	/* The command was delivered to the user. */
391 	IPMI_STAT_handled_commands,
392 
393 	/* The command had invalid data in it. */
394 	IPMI_STAT_invalid_commands,
395 
396 	/* The command didn't have anyone waiting for it. */
397 	IPMI_STAT_unhandled_commands,
398 
399 	/* Invalid data in an event. */
400 	IPMI_STAT_invalid_events,
401 
402 	/* Events that were received with the proper format. */
403 	IPMI_STAT_events,
404 
405 	/* Retransmissions on IPMB that failed. */
406 	IPMI_STAT_dropped_rexmit_ipmb_commands,
407 
408 	/* Retransmissions on LAN that failed. */
409 	IPMI_STAT_dropped_rexmit_lan_commands,
410 
411 	/* This *must* remain last, add new values above this. */
412 	IPMI_NUM_STATS
413 };
414 
415 
416 #define IPMI_IPMB_NUM_SEQ	64
417 struct ipmi_smi {
418 	struct module *owner;
419 
420 	/* What interface number are we? */
421 	int intf_num;
422 
423 	struct kref refcount;
424 
425 	/* Set when the interface is being unregistered. */
426 	bool in_shutdown;
427 
428 	/* Used for a list of interfaces. */
429 	struct list_head link;
430 
431 	/*
432 	 * The list of upper layers that are using me.
433 	 */
434 	struct list_head users;
435 	struct mutex users_mutex;
436 	atomic_t nr_users;
437 	struct device_attribute nr_users_devattr;
438 	struct device_attribute nr_msgs_devattr;
439 	struct device_attribute maintenance_mode_devattr;
440 
441 
442 	/* Used for wake ups at startup. */
443 	wait_queue_head_t waitq;
444 
445 	/*
446 	 * Prevents the interface from being unregistered when the
447 	 * interface is used by being looked up through the BMC
448 	 * structure.
449 	 */
450 	struct mutex bmc_reg_mutex;
451 
452 	struct bmc_device tmp_bmc;
453 	struct bmc_device *bmc;
454 	bool bmc_registered;
455 	struct list_head bmc_link;
456 	char *my_dev_name;
457 	bool in_bmc_register;  /* Handle recursive situations.  Yuck. */
458 	struct work_struct bmc_reg_work;
459 
460 	const struct ipmi_smi_handlers *handlers;
461 	void                     *send_info;
462 
463 	/* Driver-model device for the system interface. */
464 	struct device          *si_dev;
465 
466 	/*
467 	 * A table of sequence numbers for this interface.  We use the
468 	 * sequence numbers for IPMB messages that go out of the
469 	 * interface to match them up with their responses.  A routine
470 	 * is called periodically to time the items in this list.
471 	 */
472 	struct mutex seq_lock;
473 	struct seq_table seq_table[IPMI_IPMB_NUM_SEQ];
474 	int curr_seq;
475 
476 	/*
477 	 * Messages queued for deliver to the user.
478 	 */
479 	struct mutex user_msgs_mutex;
480 	struct list_head user_msgs;
481 
482 	/*
483 	 * Messages queued for processing.  If processing fails (out
484 	 * of memory for instance), They will stay in here to be
485 	 * processed later in a periodic timer interrupt.  The
486 	 * workqueue is for handling received messages directly from
487 	 * the handler.
488 	 */
489 	spinlock_t       waiting_rcv_msgs_lock;
490 	struct list_head waiting_rcv_msgs;
491 	atomic_t	 watchdog_pretimeouts_to_deliver;
492 	struct work_struct smi_work;
493 
494 	spinlock_t             xmit_msgs_lock;
495 	struct list_head       xmit_msgs;
496 	struct ipmi_smi_msg    *curr_msg;
497 	struct list_head       hp_xmit_msgs;
498 
499 	/*
500 	 * The list of command receivers that are registered for commands
501 	 * on this interface.
502 	 */
503 	struct mutex     cmd_rcvrs_mutex;
504 	struct list_head cmd_rcvrs;
505 
506 	/*
507 	 * Events that were queues because no one was there to receive
508 	 * them.
509 	 */
510 	struct mutex     events_mutex; /* For dealing with event stuff. */
511 	struct list_head waiting_events;
512 	unsigned int     waiting_events_count; /* How many events in queue? */
513 	char             event_msg_printed;
514 
515 	/* How many users are waiting for events? */
516 	atomic_t         event_waiters;
517 	unsigned int     ticks_to_req_ev;
518 
519 	spinlock_t       watch_lock; /* For dealing with watch stuff below. */
520 
521 	/* How many users are waiting for commands? */
522 	unsigned int     command_waiters;
523 
524 	/* How many users are waiting for watchdogs? */
525 	unsigned int     watchdog_waiters;
526 
527 	/* How many users are waiting for message responses? */
528 	unsigned int     response_waiters;
529 
530 	/*
531 	 * Tells what the lower layer has last been asked to watch for,
532 	 * messages and/or watchdogs.  Protected by watch_lock.
533 	 */
534 	unsigned int     last_watch_mask;
535 
536 	/*
537 	 * The event receiver for my BMC, only really used at panic
538 	 * shutdown as a place to store this.
539 	 */
540 	unsigned char event_receiver;
541 	unsigned char event_receiver_lun;
542 	unsigned char local_sel_device;
543 	unsigned char local_event_generator;
544 
545 	/* For handling of maintenance mode. */
546 	int maintenance_mode;
547 
548 #define IPMI_MAINTENANCE_MODE_STATE_OFF		0
549 #define IPMI_MAINTENANCE_MODE_STATE_FIRMWARE	1
550 #define IPMI_MAINTENANCE_MODE_STATE_RESET	2
551 	int maintenance_mode_state;
552 	int auto_maintenance_timeout;
553 	spinlock_t maintenance_mode_lock; /* Used in a timer... */
554 
555 	/*
556 	 * If we are doing maintenance on something on IPMB, extend
557 	 * the timeout time to avoid timeouts writing firmware and
558 	 * such.
559 	 */
560 	int ipmb_maintenance_mode_timeout;
561 
562 	/*
563 	 * A cheap hack, if this is non-null and a message to an
564 	 * interface comes in with a NULL user, call this routine with
565 	 * it.  Note that the message will still be freed by the
566 	 * caller.  This only works on the system interface.
567 	 *
568 	 * Protected by bmc_reg_mutex.
569 	 */
570 	void (*null_user_handler)(struct ipmi_smi *intf,
571 				  struct ipmi_recv_msg *msg);
572 
573 	/*
574 	 * When we are scanning the channels for an SMI, this will
575 	 * tell which channel we are scanning.
576 	 */
577 	int curr_channel;
578 
579 	/* Channel information */
580 	struct ipmi_channel_set *channel_list;
581 	unsigned int curr_working_cset; /* First index into the following. */
582 	struct ipmi_channel_set wchannels[2];
583 	struct ipmi_my_addrinfo addrinfo[IPMI_MAX_CHANNELS];
584 	bool channels_ready;
585 
586 	atomic_t stats[IPMI_NUM_STATS];
587 
588 	/*
589 	 * run_to_completion duplicate of smb_info, smi_info
590 	 * and ipmi_serial_info structures. Used to decrease numbers of
591 	 * parameters passed by "low" level IPMI code.
592 	 */
593 	int run_to_completion;
594 };
595 #define to_si_intf_from_dev(device) container_of(device, struct ipmi_smi, dev)
596 
597 static void __get_guid(struct ipmi_smi *intf);
598 static void __ipmi_bmc_unregister(struct ipmi_smi *intf);
599 static int __ipmi_bmc_register(struct ipmi_smi *intf,
600 			       struct ipmi_device_id *id,
601 			       bool guid_set, guid_t *guid, int intf_num);
602 static int __scan_channels(struct ipmi_smi *intf,
603 				struct ipmi_device_id *id, bool rescan);
604 
605 static void ipmi_lock_xmit_msgs(struct ipmi_smi *intf, int run_to_completion,
606 				unsigned long *flags)
607 {
608 	if (run_to_completion)
609 		return;
610 	spin_lock_irqsave(&intf->xmit_msgs_lock, *flags);
611 }
612 
613 static void ipmi_unlock_xmit_msgs(struct ipmi_smi *intf, int run_to_completion,
614 				  unsigned long *flags)
615 {
616 	if (run_to_completion)
617 		return;
618 	spin_unlock_irqrestore(&intf->xmit_msgs_lock, *flags);
619 }
620 
621 static void free_ipmi_user(struct kref *ref)
622 {
623 	struct ipmi_user *user = container_of(ref, struct ipmi_user, refcount);
624 	struct module *owner;
625 
626 	owner = user->intf->owner;
627 	kref_put(&user->intf->refcount, intf_free);
628 	module_put(owner);
629 	vfree(user);
630 }
631 
632 static void release_ipmi_user(struct ipmi_user *user)
633 {
634 	kref_put(&user->refcount, free_ipmi_user);
635 }
636 
637 static struct ipmi_user *acquire_ipmi_user(struct ipmi_user *user)
638 {
639 	if (!kref_get_unless_zero(&user->refcount))
640 		return NULL;
641 	return user;
642 }
643 
644 /*
645  * The driver model view of the IPMI messaging driver.
646  */
647 static struct platform_driver ipmidriver = {
648 	.driver = {
649 		.name = "ipmi",
650 		.bus = &platform_bus_type
651 	}
652 };
653 /*
654  * This mutex keeps us from adding the same BMC twice.
655  */
656 static DEFINE_MUTEX(ipmidriver_mutex);
657 
658 static LIST_HEAD(ipmi_interfaces);
659 static DEFINE_MUTEX(ipmi_interfaces_mutex);
660 
661 /*
662  * List of watchers that want to know when smi's are added and deleted.
663  */
664 static LIST_HEAD(smi_watchers);
665 static DEFINE_MUTEX(smi_watchers_mutex);
666 
667 #define ipmi_inc_stat(intf, stat) \
668 	atomic_inc(&(intf)->stats[IPMI_STAT_ ## stat])
669 #define ipmi_get_stat(intf, stat) \
670 	((unsigned int) atomic_read(&(intf)->stats[IPMI_STAT_ ## stat]))
671 
672 static const char * const addr_src_to_str[] = {
673 	"invalid", "hotmod", "hardcoded", "SPMI", "ACPI", "SMBIOS", "PCI",
674 	"device-tree", "platform"
675 };
676 
677 const char *ipmi_addr_src_to_str(enum ipmi_addr_src src)
678 {
679 	if (src >= SI_LAST)
680 		src = 0; /* Invalid */
681 	return addr_src_to_str[src];
682 }
683 EXPORT_SYMBOL(ipmi_addr_src_to_str);
684 
685 static int is_lan_addr(struct ipmi_addr *addr)
686 {
687 	return addr->addr_type == IPMI_LAN_ADDR_TYPE;
688 }
689 
690 static int is_ipmb_addr(struct ipmi_addr *addr)
691 {
692 	return addr->addr_type == IPMI_IPMB_ADDR_TYPE;
693 }
694 
695 static int is_ipmb_bcast_addr(struct ipmi_addr *addr)
696 {
697 	return addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE;
698 }
699 
700 static int is_ipmb_direct_addr(struct ipmi_addr *addr)
701 {
702 	return addr->addr_type == IPMI_IPMB_DIRECT_ADDR_TYPE;
703 }
704 
705 static void free_recv_msg_list(struct list_head *q)
706 {
707 	struct ipmi_recv_msg *msg, *msg2;
708 
709 	list_for_each_entry_safe(msg, msg2, q, link) {
710 		list_del(&msg->link);
711 		ipmi_free_recv_msg(msg);
712 	}
713 }
714 
715 static void free_smi_msg_list(struct list_head *q)
716 {
717 	struct ipmi_smi_msg *msg, *msg2;
718 
719 	list_for_each_entry_safe(msg, msg2, q, link) {
720 		list_del(&msg->link);
721 		ipmi_free_smi_msg(msg);
722 	}
723 }
724 
725 static void intf_free(struct kref *ref)
726 {
727 	struct ipmi_smi *intf = container_of(ref, struct ipmi_smi, refcount);
728 	int              i;
729 	struct cmd_rcvr  *rcvr, *rcvr2;
730 
731 	free_smi_msg_list(&intf->waiting_rcv_msgs);
732 	free_recv_msg_list(&intf->waiting_events);
733 
734 	/*
735 	 * Wholesale remove all the entries from the list in the
736 	 * interface.  No need for locks, this is single-threaded.
737 	 */
738 	list_for_each_entry_safe(rcvr, rcvr2, &intf->cmd_rcvrs, link)
739 		kfree(rcvr);
740 
741 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
742 		if ((intf->seq_table[i].inuse)
743 					&& (intf->seq_table[i].recv_msg))
744 			ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
745 	}
746 
747 	kfree(intf);
748 }
749 
750 int ipmi_smi_watcher_register(struct ipmi_smi_watcher *watcher)
751 {
752 	struct ipmi_smi *intf;
753 	unsigned int count = 0, i;
754 	int *interfaces = NULL;
755 	struct device **devices = NULL;
756 	int rv = 0;
757 
758 	/*
759 	 * Make sure the driver is actually initialized, this handles
760 	 * problems with initialization order.
761 	 */
762 	rv = ipmi_init_msghandler();
763 	if (rv)
764 		return rv;
765 
766 	mutex_lock(&smi_watchers_mutex);
767 
768 	list_add(&watcher->link, &smi_watchers);
769 
770 	/*
771 	 * Build an array of ipmi interfaces and fill it in, and
772 	 * another array of the devices.  We can't call the callback
773 	 * with ipmi_interfaces_mutex held.  smi_watchers_mutex will
774 	 * keep things in order for the user.
775 	 */
776 	mutex_lock(&ipmi_interfaces_mutex);
777 	list_for_each_entry(intf, &ipmi_interfaces, link)
778 		count++;
779 	if (count > 0) {
780 		interfaces = kmalloc_objs(*interfaces, count);
781 		if (!interfaces) {
782 			rv = -ENOMEM;
783 		} else {
784 			devices = kmalloc_objs(*devices, count);
785 			if (!devices) {
786 				kfree(interfaces);
787 				interfaces = NULL;
788 				rv = -ENOMEM;
789 			}
790 		}
791 		count = 0;
792 	}
793 	if (interfaces) {
794 		list_for_each_entry(intf, &ipmi_interfaces, link) {
795 			int intf_num = READ_ONCE(intf->intf_num);
796 
797 			if (intf_num == -1)
798 				continue;
799 			devices[count] = intf->si_dev;
800 			interfaces[count++] = intf_num;
801 		}
802 	}
803 	mutex_unlock(&ipmi_interfaces_mutex);
804 
805 	if (interfaces) {
806 		for (i = 0; i < count; i++)
807 			watcher->new_smi(interfaces[i], devices[i]);
808 		kfree(interfaces);
809 		kfree(devices);
810 	}
811 
812 	mutex_unlock(&smi_watchers_mutex);
813 
814 	return rv;
815 }
816 EXPORT_SYMBOL(ipmi_smi_watcher_register);
817 
818 int ipmi_smi_watcher_unregister(struct ipmi_smi_watcher *watcher)
819 {
820 	mutex_lock(&smi_watchers_mutex);
821 	list_del(&watcher->link);
822 	mutex_unlock(&smi_watchers_mutex);
823 	return 0;
824 }
825 EXPORT_SYMBOL(ipmi_smi_watcher_unregister);
826 
827 static void
828 call_smi_watchers(int i, struct device *dev)
829 {
830 	struct ipmi_smi_watcher *w;
831 
832 	list_for_each_entry(w, &smi_watchers, link) {
833 		if (try_module_get(w->owner)) {
834 			w->new_smi(i, dev);
835 			module_put(w->owner);
836 		}
837 	}
838 }
839 
840 static int
841 ipmi_addr_equal(struct ipmi_addr *addr1, struct ipmi_addr *addr2)
842 {
843 	if (addr1->addr_type != addr2->addr_type)
844 		return 0;
845 
846 	if (addr1->channel != addr2->channel)
847 		return 0;
848 
849 	if (addr1->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
850 		struct ipmi_system_interface_addr *smi_addr1
851 		    = (struct ipmi_system_interface_addr *) addr1;
852 		struct ipmi_system_interface_addr *smi_addr2
853 		    = (struct ipmi_system_interface_addr *) addr2;
854 		return (smi_addr1->lun == smi_addr2->lun);
855 	}
856 
857 	if (is_ipmb_addr(addr1) || is_ipmb_bcast_addr(addr1)) {
858 		struct ipmi_ipmb_addr *ipmb_addr1
859 		    = (struct ipmi_ipmb_addr *) addr1;
860 		struct ipmi_ipmb_addr *ipmb_addr2
861 		    = (struct ipmi_ipmb_addr *) addr2;
862 
863 		return ((ipmb_addr1->slave_addr == ipmb_addr2->slave_addr)
864 			&& (ipmb_addr1->lun == ipmb_addr2->lun));
865 	}
866 
867 	if (is_ipmb_direct_addr(addr1)) {
868 		struct ipmi_ipmb_direct_addr *daddr1
869 			= (struct ipmi_ipmb_direct_addr *) addr1;
870 		struct ipmi_ipmb_direct_addr *daddr2
871 			= (struct ipmi_ipmb_direct_addr *) addr2;
872 
873 		return daddr1->slave_addr == daddr2->slave_addr &&
874 			daddr1->rq_lun == daddr2->rq_lun &&
875 			daddr1->rs_lun == daddr2->rs_lun;
876 	}
877 
878 	if (is_lan_addr(addr1)) {
879 		struct ipmi_lan_addr *lan_addr1
880 			= (struct ipmi_lan_addr *) addr1;
881 		struct ipmi_lan_addr *lan_addr2
882 		    = (struct ipmi_lan_addr *) addr2;
883 
884 		return ((lan_addr1->remote_SWID == lan_addr2->remote_SWID)
885 			&& (lan_addr1->local_SWID == lan_addr2->local_SWID)
886 			&& (lan_addr1->session_handle
887 			    == lan_addr2->session_handle)
888 			&& (lan_addr1->lun == lan_addr2->lun));
889 	}
890 
891 	return 1;
892 }
893 
894 int ipmi_validate_addr(struct ipmi_addr *addr, int len)
895 {
896 	if (len < sizeof(struct ipmi_system_interface_addr))
897 		return -EINVAL;
898 
899 	if (addr->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
900 		if (addr->channel != IPMI_BMC_CHANNEL)
901 			return -EINVAL;
902 		return 0;
903 	}
904 
905 	if ((addr->channel == IPMI_BMC_CHANNEL)
906 	    || (addr->channel >= IPMI_MAX_CHANNELS)
907 	    || (addr->channel < 0))
908 		return -EINVAL;
909 
910 	if (is_ipmb_addr(addr) || is_ipmb_bcast_addr(addr)) {
911 		if (len < sizeof(struct ipmi_ipmb_addr))
912 			return -EINVAL;
913 		return 0;
914 	}
915 
916 	if (is_ipmb_direct_addr(addr)) {
917 		struct ipmi_ipmb_direct_addr *daddr = (void *) addr;
918 
919 		if (addr->channel != 0)
920 			return -EINVAL;
921 		if (len < sizeof(struct ipmi_ipmb_direct_addr))
922 			return -EINVAL;
923 
924 		if (daddr->slave_addr & 0x01)
925 			return -EINVAL;
926 		if (daddr->rq_lun >= 4)
927 			return -EINVAL;
928 		if (daddr->rs_lun >= 4)
929 			return -EINVAL;
930 		return 0;
931 	}
932 
933 	if (is_lan_addr(addr)) {
934 		if (len < sizeof(struct ipmi_lan_addr))
935 			return -EINVAL;
936 		return 0;
937 	}
938 
939 	return -EINVAL;
940 }
941 EXPORT_SYMBOL(ipmi_validate_addr);
942 
943 unsigned int ipmi_addr_length(int addr_type)
944 {
945 	if (addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
946 		return sizeof(struct ipmi_system_interface_addr);
947 
948 	if ((addr_type == IPMI_IPMB_ADDR_TYPE)
949 			|| (addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE))
950 		return sizeof(struct ipmi_ipmb_addr);
951 
952 	if (addr_type == IPMI_IPMB_DIRECT_ADDR_TYPE)
953 		return sizeof(struct ipmi_ipmb_direct_addr);
954 
955 	if (addr_type == IPMI_LAN_ADDR_TYPE)
956 		return sizeof(struct ipmi_lan_addr);
957 
958 	return 0;
959 }
960 EXPORT_SYMBOL(ipmi_addr_length);
961 
962 static int deliver_response(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
963 {
964 	int rv = 0;
965 
966 	if (!msg->user) {
967 		/* Special handling for NULL users. */
968 		if (intf->null_user_handler) {
969 			intf->null_user_handler(intf, msg);
970 		} else {
971 			/* No handler, so give up. */
972 			rv = -EINVAL;
973 		}
974 		ipmi_free_recv_msg(msg);
975 	} else if (oops_in_progress) {
976 		/*
977 		 * If we are running in the panic context, calling the
978 		 * receive handler doesn't much meaning and has a deadlock
979 		 * risk.  At this moment, simply skip it in that case.
980 		 */
981 		ipmi_free_recv_msg(msg);
982 	} else {
983 		/*
984 		 * Deliver it in smi_work.  The message will hold a
985 		 * refcount to the user.
986 		 */
987 		mutex_lock(&intf->user_msgs_mutex);
988 		list_add_tail(&msg->link, &intf->user_msgs);
989 		mutex_unlock(&intf->user_msgs_mutex);
990 		queue_work(system_percpu_wq, &intf->smi_work);
991 	}
992 
993 	return rv;
994 }
995 
996 static void deliver_local_response(struct ipmi_smi *intf,
997 				   struct ipmi_recv_msg *msg)
998 {
999 	if (deliver_response(intf, msg))
1000 		ipmi_inc_stat(intf, unhandled_local_responses);
1001 	else
1002 		ipmi_inc_stat(intf, handled_local_responses);
1003 }
1004 
1005 static void deliver_err_response(struct ipmi_smi *intf,
1006 				 struct ipmi_recv_msg *msg, int err)
1007 {
1008 	msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
1009 	msg->msg_data[0] = err;
1010 	msg->msg.netfn |= 1; /* Convert to a response. */
1011 	msg->msg.data_len = 1;
1012 	msg->msg.data = msg->msg_data;
1013 	deliver_local_response(intf, msg);
1014 }
1015 
1016 static void smi_add_watch(struct ipmi_smi *intf, unsigned int flags)
1017 {
1018 	unsigned long iflags;
1019 
1020 	if (!intf->handlers->set_need_watch)
1021 		return;
1022 
1023 	spin_lock_irqsave(&intf->watch_lock, iflags);
1024 	if (flags & IPMI_WATCH_MASK_CHECK_MESSAGES)
1025 		intf->response_waiters++;
1026 
1027 	if (flags & IPMI_WATCH_MASK_CHECK_WATCHDOG)
1028 		intf->watchdog_waiters++;
1029 
1030 	if (flags & IPMI_WATCH_MASK_CHECK_COMMANDS)
1031 		intf->command_waiters++;
1032 
1033 	if ((intf->last_watch_mask & flags) != flags) {
1034 		intf->last_watch_mask |= flags;
1035 		intf->handlers->set_need_watch(intf->send_info,
1036 					       intf->last_watch_mask);
1037 	}
1038 	spin_unlock_irqrestore(&intf->watch_lock, iflags);
1039 }
1040 
1041 static void smi_remove_watch(struct ipmi_smi *intf, unsigned int flags)
1042 {
1043 	unsigned long iflags;
1044 
1045 	if (!intf->handlers->set_need_watch)
1046 		return;
1047 
1048 	spin_lock_irqsave(&intf->watch_lock, iflags);
1049 	if (flags & IPMI_WATCH_MASK_CHECK_MESSAGES)
1050 		intf->response_waiters--;
1051 
1052 	if (flags & IPMI_WATCH_MASK_CHECK_WATCHDOG)
1053 		intf->watchdog_waiters--;
1054 
1055 	if (flags & IPMI_WATCH_MASK_CHECK_COMMANDS)
1056 		intf->command_waiters--;
1057 
1058 	flags = 0;
1059 	if (intf->response_waiters)
1060 		flags |= IPMI_WATCH_MASK_CHECK_MESSAGES;
1061 	if (intf->watchdog_waiters)
1062 		flags |= IPMI_WATCH_MASK_CHECK_WATCHDOG;
1063 	if (intf->command_waiters)
1064 		flags |= IPMI_WATCH_MASK_CHECK_COMMANDS;
1065 
1066 	if (intf->last_watch_mask != flags) {
1067 		intf->last_watch_mask = flags;
1068 		intf->handlers->set_need_watch(intf->send_info,
1069 					       intf->last_watch_mask);
1070 	}
1071 	spin_unlock_irqrestore(&intf->watch_lock, iflags);
1072 }
1073 
1074 /*
1075  * Find the next sequence number not being used and add the given
1076  * message with the given timeout to the sequence table.  This must be
1077  * called with the interface's seq_lock held.
1078  */
1079 static int intf_next_seq(struct ipmi_smi      *intf,
1080 			 struct ipmi_recv_msg *recv_msg,
1081 			 unsigned long        timeout,
1082 			 int                  retries,
1083 			 int                  broadcast,
1084 			 unsigned char        *seq,
1085 			 long                 *seqid)
1086 {
1087 	int          rv = 0;
1088 	unsigned int i;
1089 
1090 	if (timeout == 0)
1091 		timeout = default_retry_ms;
1092 	if (retries < 0)
1093 		retries = default_max_retries;
1094 
1095 	for (i = intf->curr_seq; (i+1)%IPMI_IPMB_NUM_SEQ != intf->curr_seq;
1096 					i = (i+1)%IPMI_IPMB_NUM_SEQ) {
1097 		if (!intf->seq_table[i].inuse)
1098 			break;
1099 	}
1100 
1101 	if (!intf->seq_table[i].inuse) {
1102 		intf->seq_table[i].recv_msg = recv_msg;
1103 
1104 		/*
1105 		 * Start with the maximum timeout, when the send response
1106 		 * comes in we will start the real timer.
1107 		 */
1108 		intf->seq_table[i].timeout = MAX_MSG_TIMEOUT;
1109 		intf->seq_table[i].orig_timeout = timeout;
1110 		intf->seq_table[i].retries_left = retries;
1111 		intf->seq_table[i].broadcast = broadcast;
1112 		intf->seq_table[i].inuse = 1;
1113 		intf->seq_table[i].seqid = NEXT_SEQID(intf->seq_table[i].seqid);
1114 		*seq = i;
1115 		*seqid = intf->seq_table[i].seqid;
1116 		intf->curr_seq = (i+1)%IPMI_IPMB_NUM_SEQ;
1117 		smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1118 		need_waiter(intf);
1119 	} else {
1120 		rv = -EAGAIN;
1121 	}
1122 
1123 	return rv;
1124 }
1125 
1126 /*
1127  * Return the receive message for the given sequence number and
1128  * release the sequence number so it can be reused.  Some other data
1129  * is passed in to be sure the message matches up correctly (to help
1130  * guard against message coming in after their timeout and the
1131  * sequence number being reused).
1132  */
1133 static int intf_find_seq(struct ipmi_smi      *intf,
1134 			 unsigned char        seq,
1135 			 short                channel,
1136 			 unsigned char        cmd,
1137 			 unsigned char        netfn,
1138 			 struct ipmi_addr     *addr,
1139 			 struct ipmi_recv_msg **recv_msg)
1140 {
1141 	int           rv = -ENODEV;
1142 
1143 	if (seq >= IPMI_IPMB_NUM_SEQ)
1144 		return -EINVAL;
1145 
1146 	mutex_lock(&intf->seq_lock);
1147 	if (intf->seq_table[seq].inuse) {
1148 		struct ipmi_recv_msg *msg = intf->seq_table[seq].recv_msg;
1149 
1150 		if ((msg->addr.channel == channel) && (msg->msg.cmd == cmd)
1151 				&& (msg->msg.netfn == netfn)
1152 				&& (ipmi_addr_equal(addr, &msg->addr))) {
1153 			*recv_msg = msg;
1154 			intf->seq_table[seq].inuse = 0;
1155 			smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1156 			rv = 0;
1157 		}
1158 	}
1159 	mutex_unlock(&intf->seq_lock);
1160 
1161 	return rv;
1162 }
1163 
1164 
1165 /* Start the timer for a specific sequence table entry. */
1166 static int intf_start_seq_timer(struct ipmi_smi *intf,
1167 				long       msgid)
1168 {
1169 	int           rv = -ENODEV;
1170 	unsigned char seq;
1171 	unsigned long seqid;
1172 
1173 
1174 	GET_SEQ_FROM_MSGID(msgid, seq, seqid);
1175 
1176 	mutex_lock(&intf->seq_lock);
1177 	/*
1178 	 * We do this verification because the user can be deleted
1179 	 * while a message is outstanding.
1180 	 */
1181 	if ((intf->seq_table[seq].inuse)
1182 				&& (intf->seq_table[seq].seqid == seqid)) {
1183 		struct seq_table *ent = &intf->seq_table[seq];
1184 		ent->timeout = ent->orig_timeout;
1185 		rv = 0;
1186 	}
1187 	mutex_unlock(&intf->seq_lock);
1188 
1189 	return rv;
1190 }
1191 
1192 /* Got an error for the send message for a specific sequence number. */
1193 static int intf_err_seq(struct ipmi_smi *intf,
1194 			long         msgid,
1195 			unsigned int err)
1196 {
1197 	int                  rv = -ENODEV;
1198 	unsigned char        seq;
1199 	unsigned long        seqid;
1200 	struct ipmi_recv_msg *msg = NULL;
1201 
1202 
1203 	GET_SEQ_FROM_MSGID(msgid, seq, seqid);
1204 
1205 	mutex_lock(&intf->seq_lock);
1206 	/*
1207 	 * We do this verification because the user can be deleted
1208 	 * while a message is outstanding.
1209 	 */
1210 	if ((intf->seq_table[seq].inuse)
1211 				&& (intf->seq_table[seq].seqid == seqid)) {
1212 		struct seq_table *ent = &intf->seq_table[seq];
1213 
1214 		ent->inuse = 0;
1215 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1216 		msg = ent->recv_msg;
1217 		rv = 0;
1218 	}
1219 	mutex_unlock(&intf->seq_lock);
1220 
1221 	if (msg)
1222 		deliver_err_response(intf, msg, err);
1223 
1224 	return rv;
1225 }
1226 
1227 int ipmi_create_user(unsigned int          if_num,
1228 		     const struct ipmi_user_hndl *handler,
1229 		     void                  *handler_data,
1230 		     struct ipmi_user      **user)
1231 {
1232 	struct ipmi_user *new_user = NULL;
1233 	int           rv = 0;
1234 	struct ipmi_smi *intf;
1235 
1236 	/*
1237 	 * There is no module usecount here, because it's not
1238 	 * required.  Since this can only be used by and called from
1239 	 * other modules, they will implicitly use this module, and
1240 	 * thus this can't be removed unless the other modules are
1241 	 * removed.
1242 	 */
1243 
1244 	if (handler == NULL)
1245 		return -EINVAL;
1246 
1247 	/*
1248 	 * Make sure the driver is actually initialized, this handles
1249 	 * problems with initialization order.
1250 	 */
1251 	rv = ipmi_init_msghandler();
1252 	if (rv)
1253 		return rv;
1254 
1255 	mutex_lock(&ipmi_interfaces_mutex);
1256 	list_for_each_entry(intf, &ipmi_interfaces, link) {
1257 		if (intf->intf_num == if_num)
1258 			goto found;
1259 	}
1260 	/* Not found, return an error */
1261 	rv = -EINVAL;
1262 	goto out_unlock;
1263 
1264  found:
1265 	if (intf->in_shutdown) {
1266 		rv = -ENODEV;
1267 		goto out_unlock;
1268 	}
1269 
1270 	if (atomic_add_return(1, &intf->nr_users) > max_users) {
1271 		rv = -EBUSY;
1272 		goto out_kfree;
1273 	}
1274 
1275 	new_user = vzalloc(sizeof(*new_user));
1276 	if (!new_user) {
1277 		rv = -ENOMEM;
1278 		goto out_kfree;
1279 	}
1280 
1281 	if (!try_module_get(intf->owner)) {
1282 		rv = -ENODEV;
1283 		goto out_kfree;
1284 	}
1285 
1286 	/* Note that each existing user holds a refcount to the interface. */
1287 	kref_get(&intf->refcount);
1288 
1289 	atomic_set(&new_user->nr_msgs, 0);
1290 	kref_init(&new_user->refcount);
1291 	refcount_set(&new_user->destroyed, 1);
1292 	kref_get(&new_user->refcount); /* Destroy owns a refcount. */
1293 	new_user->handler = handler;
1294 	new_user->handler_data = handler_data;
1295 	new_user->intf = intf;
1296 	new_user->gets_events = false;
1297 
1298 	mutex_lock(&intf->users_mutex);
1299 	mutex_lock(&intf->seq_lock);
1300 	list_add(&new_user->link, &intf->users);
1301 	mutex_unlock(&intf->seq_lock);
1302 	mutex_unlock(&intf->users_mutex);
1303 
1304 	if (handler->ipmi_watchdog_pretimeout)
1305 		/* User wants pretimeouts, so make sure to watch for them. */
1306 		smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_WATCHDOG);
1307 
1308 out_kfree:
1309 	if (rv) {
1310 		atomic_dec(&intf->nr_users);
1311 		vfree(new_user);
1312 	} else {
1313 		*user = new_user;
1314 	}
1315 out_unlock:
1316 	mutex_unlock(&ipmi_interfaces_mutex);
1317 	return rv;
1318 }
1319 EXPORT_SYMBOL(ipmi_create_user);
1320 
1321 int ipmi_get_smi_info(int if_num, struct ipmi_smi_info *data)
1322 {
1323 	int rv = -EINVAL;
1324 	struct ipmi_smi *intf;
1325 
1326 	mutex_lock(&ipmi_interfaces_mutex);
1327 	list_for_each_entry(intf, &ipmi_interfaces, link) {
1328 		if (intf->intf_num == if_num) {
1329 			if (!intf->handlers->get_smi_info)
1330 				rv = -ENOTTY;
1331 			else
1332 				rv = intf->handlers->get_smi_info(intf->send_info, data);
1333 			break;
1334 		}
1335 	}
1336 	mutex_unlock(&ipmi_interfaces_mutex);
1337 
1338 	return rv;
1339 }
1340 EXPORT_SYMBOL(ipmi_get_smi_info);
1341 
1342 /* Must be called with intf->users_mutex held. */
1343 static void _ipmi_destroy_user(struct ipmi_user *user)
1344 {
1345 	struct ipmi_smi  *intf = user->intf;
1346 	int              i;
1347 	struct cmd_rcvr  *rcvr;
1348 	struct cmd_rcvr  *rcvrs = NULL;
1349 	struct ipmi_recv_msg *msg, *msg2;
1350 
1351 	if (!refcount_dec_if_one(&user->destroyed))
1352 		return;
1353 
1354 	if (user->handler->shutdown)
1355 		user->handler->shutdown(user->handler_data);
1356 
1357 	if (user->handler->ipmi_watchdog_pretimeout)
1358 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_WATCHDOG);
1359 
1360 	if (user->gets_events)
1361 		atomic_dec(&intf->event_waiters);
1362 
1363 	/* Remove the user from the interface's list and sequence table. */
1364 	list_del(&user->link);
1365 	atomic_dec(&intf->nr_users);
1366 
1367 	mutex_lock(&intf->seq_lock);
1368 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
1369 		if (intf->seq_table[i].inuse
1370 		    && (intf->seq_table[i].recv_msg->user == user)) {
1371 			intf->seq_table[i].inuse = 0;
1372 			smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1373 			ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
1374 		}
1375 	}
1376 	mutex_unlock(&intf->seq_lock);
1377 
1378 	/*
1379 	 * Remove the user from the command receiver's table.  First
1380 	 * we build a list of everything (not using the standard link,
1381 	 * since other things may be using it till we do
1382 	 * synchronize_rcu()) then free everything in that list.
1383 	 */
1384 	mutex_lock(&intf->cmd_rcvrs_mutex);
1385 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1386 				lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1387 		if (rcvr->user == user) {
1388 			list_del_rcu(&rcvr->link);
1389 			rcvr->next = rcvrs;
1390 			rcvrs = rcvr;
1391 		}
1392 	}
1393 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1394 	synchronize_rcu();
1395 	while (rcvrs) {
1396 		rcvr = rcvrs;
1397 		rcvrs = rcvr->next;
1398 		kfree(rcvr);
1399 	}
1400 
1401 	mutex_lock(&intf->user_msgs_mutex);
1402 	list_for_each_entry_safe(msg, msg2, &intf->user_msgs, link) {
1403 		if (msg->user != user)
1404 			continue;
1405 		list_del(&msg->link);
1406 		ipmi_free_recv_msg(msg);
1407 	}
1408 	mutex_unlock(&intf->user_msgs_mutex);
1409 
1410 	release_ipmi_user(user);
1411 }
1412 
1413 void ipmi_destroy_user(struct ipmi_user *user)
1414 {
1415 	struct ipmi_smi *intf = user->intf;
1416 
1417 	mutex_lock(&intf->users_mutex);
1418 	_ipmi_destroy_user(user);
1419 	mutex_unlock(&intf->users_mutex);
1420 
1421 	kref_put(&user->refcount, free_ipmi_user);
1422 }
1423 EXPORT_SYMBOL(ipmi_destroy_user);
1424 
1425 int ipmi_get_version(struct ipmi_user *user,
1426 		     unsigned char *major,
1427 		     unsigned char *minor)
1428 {
1429 	struct ipmi_device_id id;
1430 	int rv;
1431 
1432 	user = acquire_ipmi_user(user);
1433 	if (!user)
1434 		return -ENODEV;
1435 
1436 	rv = bmc_get_device_id(user->intf, NULL, &id, NULL, NULL);
1437 	if (!rv) {
1438 		*major = ipmi_version_major(&id);
1439 		*minor = ipmi_version_minor(&id);
1440 	}
1441 	release_ipmi_user(user);
1442 
1443 	return rv;
1444 }
1445 EXPORT_SYMBOL(ipmi_get_version);
1446 
1447 int ipmi_set_my_address(struct ipmi_user *user,
1448 			unsigned int  channel,
1449 			unsigned char address)
1450 {
1451 	int rv = 0;
1452 
1453 	user = acquire_ipmi_user(user);
1454 	if (!user)
1455 		return -ENODEV;
1456 
1457 	if (channel >= IPMI_MAX_CHANNELS) {
1458 		rv = -EINVAL;
1459 	} else {
1460 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1461 		user->intf->addrinfo[channel].address = address;
1462 	}
1463 	release_ipmi_user(user);
1464 
1465 	return rv;
1466 }
1467 EXPORT_SYMBOL(ipmi_set_my_address);
1468 
1469 int ipmi_get_my_address(struct ipmi_user *user,
1470 			unsigned int  channel,
1471 			unsigned char *address)
1472 {
1473 	int rv = 0;
1474 
1475 	user = acquire_ipmi_user(user);
1476 	if (!user)
1477 		return -ENODEV;
1478 
1479 	if (channel >= IPMI_MAX_CHANNELS) {
1480 		rv = -EINVAL;
1481 	} else {
1482 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1483 		*address = user->intf->addrinfo[channel].address;
1484 	}
1485 	release_ipmi_user(user);
1486 
1487 	return rv;
1488 }
1489 EXPORT_SYMBOL(ipmi_get_my_address);
1490 
1491 int ipmi_set_my_LUN(struct ipmi_user *user,
1492 		    unsigned int  channel,
1493 		    unsigned char LUN)
1494 {
1495 	int rv = 0;
1496 
1497 	user = acquire_ipmi_user(user);
1498 	if (!user)
1499 		return -ENODEV;
1500 
1501 	if (channel >= IPMI_MAX_CHANNELS) {
1502 		rv = -EINVAL;
1503 	} else {
1504 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1505 		user->intf->addrinfo[channel].lun = LUN & 0x3;
1506 	}
1507 	release_ipmi_user(user);
1508 
1509 	return rv;
1510 }
1511 EXPORT_SYMBOL(ipmi_set_my_LUN);
1512 
1513 int ipmi_get_my_LUN(struct ipmi_user *user,
1514 		    unsigned int  channel,
1515 		    unsigned char *address)
1516 {
1517 	int rv = 0;
1518 
1519 	user = acquire_ipmi_user(user);
1520 	if (!user)
1521 		return -ENODEV;
1522 
1523 	if (channel >= IPMI_MAX_CHANNELS) {
1524 		rv = -EINVAL;
1525 	} else {
1526 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1527 		*address = user->intf->addrinfo[channel].lun;
1528 	}
1529 	release_ipmi_user(user);
1530 
1531 	return rv;
1532 }
1533 EXPORT_SYMBOL(ipmi_get_my_LUN);
1534 
1535 int ipmi_get_maintenance_mode(struct ipmi_user *user)
1536 {
1537 	int mode;
1538 	unsigned long flags;
1539 
1540 	user = acquire_ipmi_user(user);
1541 	if (!user)
1542 		return -ENODEV;
1543 
1544 	spin_lock_irqsave(&user->intf->maintenance_mode_lock, flags);
1545 	mode = user->intf->maintenance_mode;
1546 	spin_unlock_irqrestore(&user->intf->maintenance_mode_lock, flags);
1547 	release_ipmi_user(user);
1548 
1549 	return mode;
1550 }
1551 EXPORT_SYMBOL(ipmi_get_maintenance_mode);
1552 
1553 static void maintenance_mode_update(struct ipmi_smi *intf)
1554 {
1555 	if (intf->handlers->set_maintenance_mode)
1556 		/*
1557 		 * Lower level drivers only care about firmware mode
1558 		 * as it affects their timing.  They don't care about
1559 		 * reset, which disables all commands for a while.
1560 		 */
1561 		intf->handlers->set_maintenance_mode(
1562 			intf->send_info,
1563 			(intf->maintenance_mode_state ==
1564 			 IPMI_MAINTENANCE_MODE_STATE_FIRMWARE));
1565 }
1566 
1567 int ipmi_set_maintenance_mode(struct ipmi_user *user, int mode)
1568 {
1569 	int rv = 0;
1570 	unsigned long flags;
1571 	struct ipmi_smi *intf = user->intf;
1572 
1573 	user = acquire_ipmi_user(user);
1574 	if (!user)
1575 		return -ENODEV;
1576 
1577 	spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
1578 	if (intf->maintenance_mode != mode) {
1579 		switch (mode) {
1580 		case IPMI_MAINTENANCE_MODE_AUTO:
1581 			/* Just leave it alone. */
1582 			break;
1583 
1584 		case IPMI_MAINTENANCE_MODE_OFF:
1585 			intf->maintenance_mode_state =
1586 				IPMI_MAINTENANCE_MODE_STATE_OFF;
1587 			break;
1588 
1589 		case IPMI_MAINTENANCE_MODE_ON:
1590 			intf->maintenance_mode_state =
1591 				IPMI_MAINTENANCE_MODE_STATE_FIRMWARE;
1592 			break;
1593 
1594 		default:
1595 			rv = -EINVAL;
1596 			goto out_unlock;
1597 		}
1598 		intf->maintenance_mode = mode;
1599 
1600 		maintenance_mode_update(intf);
1601 	}
1602  out_unlock:
1603 	spin_unlock_irqrestore(&intf->maintenance_mode_lock, flags);
1604 	release_ipmi_user(user);
1605 
1606 	return rv;
1607 }
1608 EXPORT_SYMBOL(ipmi_set_maintenance_mode);
1609 
1610 int ipmi_set_gets_events(struct ipmi_user *user, bool val)
1611 {
1612 	struct ipmi_smi      *intf = user->intf;
1613 	struct ipmi_recv_msg *msg, *msg2;
1614 	LIST_HEAD(msgs);
1615 
1616 	user = acquire_ipmi_user(user);
1617 	if (!user)
1618 		return -ENODEV;
1619 
1620 	mutex_lock(&intf->events_mutex);
1621 	if (user->gets_events == val)
1622 		goto out;
1623 
1624 	user->gets_events = val;
1625 
1626 	if (val) {
1627 		if (atomic_inc_return(&intf->event_waiters) == 1)
1628 			need_waiter(intf);
1629 	} else {
1630 		atomic_dec(&intf->event_waiters);
1631 	}
1632 
1633 	/* Deliver any queued events. */
1634 	while (user->gets_events && !list_empty(&intf->waiting_events)) {
1635 		list_for_each_entry_safe(msg, msg2, &intf->waiting_events, link)
1636 			list_move_tail(&msg->link, &msgs);
1637 		intf->waiting_events_count = 0;
1638 		if (intf->event_msg_printed) {
1639 			dev_warn(intf->si_dev, "Event queue no longer full\n");
1640 			intf->event_msg_printed = 0;
1641 		}
1642 
1643 		list_for_each_entry_safe(msg, msg2, &msgs, link) {
1644 			ipmi_set_recv_msg_user(msg, user);
1645 			deliver_local_response(intf, msg);
1646 		}
1647 	}
1648 
1649  out:
1650 	mutex_unlock(&intf->events_mutex);
1651 	release_ipmi_user(user);
1652 
1653 	return 0;
1654 }
1655 EXPORT_SYMBOL(ipmi_set_gets_events);
1656 
1657 static struct cmd_rcvr *find_cmd_rcvr(struct ipmi_smi *intf,
1658 				      unsigned char netfn,
1659 				      unsigned char cmd,
1660 				      unsigned char chan)
1661 {
1662 	struct cmd_rcvr *rcvr;
1663 
1664 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1665 				lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1666 		if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
1667 					&& (rcvr->chans & (1 << chan)))
1668 			return rcvr;
1669 	}
1670 	return NULL;
1671 }
1672 
1673 static int is_cmd_rcvr_exclusive(struct ipmi_smi *intf,
1674 				 unsigned char netfn,
1675 				 unsigned char cmd,
1676 				 unsigned int  chans)
1677 {
1678 	struct cmd_rcvr *rcvr;
1679 
1680 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1681 				lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1682 		if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
1683 					&& (rcvr->chans & chans))
1684 			return 0;
1685 	}
1686 	return 1;
1687 }
1688 
1689 int ipmi_register_for_cmd(struct ipmi_user *user,
1690 			  unsigned char netfn,
1691 			  unsigned char cmd,
1692 			  unsigned int  chans)
1693 {
1694 	struct ipmi_smi *intf = user->intf;
1695 	struct cmd_rcvr *rcvr;
1696 	int rv = 0;
1697 
1698 	user = acquire_ipmi_user(user);
1699 	if (!user)
1700 		return -ENODEV;
1701 
1702 	rcvr = kmalloc_obj(*rcvr);
1703 	if (!rcvr) {
1704 		rv = -ENOMEM;
1705 		goto out_release;
1706 	}
1707 	rcvr->cmd = cmd;
1708 	rcvr->netfn = netfn;
1709 	rcvr->chans = chans;
1710 	rcvr->user = user;
1711 
1712 	mutex_lock(&intf->cmd_rcvrs_mutex);
1713 	/* Make sure the command/netfn is not already registered. */
1714 	if (!is_cmd_rcvr_exclusive(intf, netfn, cmd, chans)) {
1715 		rv = -EBUSY;
1716 		goto out_unlock;
1717 	}
1718 
1719 	smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS);
1720 
1721 	list_add_rcu(&rcvr->link, &intf->cmd_rcvrs);
1722 
1723 out_unlock:
1724 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1725 	if (rv)
1726 		kfree(rcvr);
1727 out_release:
1728 	release_ipmi_user(user);
1729 
1730 	return rv;
1731 }
1732 EXPORT_SYMBOL(ipmi_register_for_cmd);
1733 
1734 int ipmi_unregister_for_cmd(struct ipmi_user *user,
1735 			    unsigned char netfn,
1736 			    unsigned char cmd,
1737 			    unsigned int  chans)
1738 {
1739 	struct ipmi_smi *intf = user->intf;
1740 	struct cmd_rcvr *rcvr;
1741 	struct cmd_rcvr *rcvrs = NULL;
1742 	int i, rv = -ENOENT;
1743 
1744 	user = acquire_ipmi_user(user);
1745 	if (!user)
1746 		return -ENODEV;
1747 
1748 	mutex_lock(&intf->cmd_rcvrs_mutex);
1749 	for (i = 0; i < IPMI_NUM_CHANNELS; i++) {
1750 		if (((1 << i) & chans) == 0)
1751 			continue;
1752 		rcvr = find_cmd_rcvr(intf, netfn, cmd, i);
1753 		if (rcvr == NULL)
1754 			continue;
1755 		if (rcvr->user == user) {
1756 			rv = 0;
1757 			rcvr->chans &= ~chans;
1758 			if (rcvr->chans == 0) {
1759 				list_del_rcu(&rcvr->link);
1760 				rcvr->next = rcvrs;
1761 				rcvrs = rcvr;
1762 			}
1763 		}
1764 	}
1765 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1766 	synchronize_rcu();
1767 	release_ipmi_user(user);
1768 	while (rcvrs) {
1769 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS);
1770 		rcvr = rcvrs;
1771 		rcvrs = rcvr->next;
1772 		kfree(rcvr);
1773 	}
1774 
1775 	return rv;
1776 }
1777 EXPORT_SYMBOL(ipmi_unregister_for_cmd);
1778 
1779 unsigned char
1780 ipmb_checksum(unsigned char *data, int size)
1781 {
1782 	unsigned char csum = 0;
1783 
1784 	for (; size > 0; size--, data++)
1785 		csum += *data;
1786 
1787 	return -csum;
1788 }
1789 EXPORT_SYMBOL(ipmb_checksum);
1790 
1791 static inline void format_ipmb_msg(struct ipmi_smi_msg   *smi_msg,
1792 				   struct kernel_ipmi_msg *msg,
1793 				   struct ipmi_ipmb_addr *ipmb_addr,
1794 				   long                  msgid,
1795 				   unsigned char         ipmb_seq,
1796 				   int                   broadcast,
1797 				   unsigned char         source_address,
1798 				   unsigned char         source_lun)
1799 {
1800 	int i = broadcast;
1801 
1802 	/* Format the IPMB header data. */
1803 	smi_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
1804 	smi_msg->data[1] = IPMI_SEND_MSG_CMD;
1805 	smi_msg->data[2] = ipmb_addr->channel;
1806 	if (broadcast)
1807 		smi_msg->data[3] = 0;
1808 	smi_msg->data[i+3] = ipmb_addr->slave_addr;
1809 	smi_msg->data[i+4] = (msg->netfn << 2) | (ipmb_addr->lun & 0x3);
1810 	smi_msg->data[i+5] = ipmb_checksum(&smi_msg->data[i + 3], 2);
1811 	smi_msg->data[i+6] = source_address;
1812 	smi_msg->data[i+7] = (ipmb_seq << 2) | source_lun;
1813 	smi_msg->data[i+8] = msg->cmd;
1814 
1815 	/* Now tack on the data to the message. */
1816 	if (msg->data_len > 0)
1817 		memcpy(&smi_msg->data[i + 9], msg->data, msg->data_len);
1818 	smi_msg->data_size = msg->data_len + 9;
1819 
1820 	/* Now calculate the checksum and tack it on. */
1821 	smi_msg->data[i+smi_msg->data_size]
1822 		= ipmb_checksum(&smi_msg->data[i + 6], smi_msg->data_size - 6);
1823 
1824 	/*
1825 	 * Add on the checksum size and the offset from the
1826 	 * broadcast.
1827 	 */
1828 	smi_msg->data_size += 1 + i;
1829 
1830 	smi_msg->msgid = msgid;
1831 }
1832 
1833 static inline void format_lan_msg(struct ipmi_smi_msg   *smi_msg,
1834 				  struct kernel_ipmi_msg *msg,
1835 				  struct ipmi_lan_addr  *lan_addr,
1836 				  long                  msgid,
1837 				  unsigned char         ipmb_seq,
1838 				  unsigned char         source_lun)
1839 {
1840 	/* Format the IPMB header data. */
1841 	smi_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
1842 	smi_msg->data[1] = IPMI_SEND_MSG_CMD;
1843 	smi_msg->data[2] = lan_addr->channel;
1844 	smi_msg->data[3] = lan_addr->session_handle;
1845 	smi_msg->data[4] = lan_addr->remote_SWID;
1846 	smi_msg->data[5] = (msg->netfn << 2) | (lan_addr->lun & 0x3);
1847 	smi_msg->data[6] = ipmb_checksum(&smi_msg->data[4], 2);
1848 	smi_msg->data[7] = lan_addr->local_SWID;
1849 	smi_msg->data[8] = (ipmb_seq << 2) | source_lun;
1850 	smi_msg->data[9] = msg->cmd;
1851 
1852 	/* Now tack on the data to the message. */
1853 	if (msg->data_len > 0)
1854 		memcpy(&smi_msg->data[10], msg->data, msg->data_len);
1855 	smi_msg->data_size = msg->data_len + 10;
1856 
1857 	/* Now calculate the checksum and tack it on. */
1858 	smi_msg->data[smi_msg->data_size]
1859 		= ipmb_checksum(&smi_msg->data[7], smi_msg->data_size - 7);
1860 
1861 	/*
1862 	 * Add on the checksum size and the offset from the
1863 	 * broadcast.
1864 	 */
1865 	smi_msg->data_size += 1;
1866 
1867 	smi_msg->msgid = msgid;
1868 }
1869 
1870 static struct ipmi_smi_msg *smi_add_send_msg(struct ipmi_smi *intf,
1871 					     struct ipmi_smi_msg *smi_msg,
1872 					     int priority)
1873 {
1874 	if (intf->curr_msg) {
1875 		if (priority > 0)
1876 			list_add_tail(&smi_msg->link, &intf->hp_xmit_msgs);
1877 		else
1878 			list_add_tail(&smi_msg->link, &intf->xmit_msgs);
1879 		smi_msg = NULL;
1880 	} else {
1881 		intf->curr_msg = smi_msg;
1882 	}
1883 
1884 	return smi_msg;
1885 }
1886 
1887 static int smi_send(struct ipmi_smi *intf,
1888 		     const struct ipmi_smi_handlers *handlers,
1889 		     struct ipmi_smi_msg *smi_msg, int priority)
1890 {
1891 	int run_to_completion = READ_ONCE(intf->run_to_completion);
1892 	unsigned long flags = 0;
1893 	int rv = 0;
1894 
1895 	ipmi_lock_xmit_msgs(intf, run_to_completion, &flags);
1896 	smi_msg = smi_add_send_msg(intf, smi_msg, priority);
1897 	ipmi_unlock_xmit_msgs(intf, run_to_completion, &flags);
1898 
1899 	if (smi_msg) {
1900 		rv = handlers->sender(intf->send_info, smi_msg);
1901 		if (rv) {
1902 			ipmi_lock_xmit_msgs(intf, run_to_completion, &flags);
1903 			intf->curr_msg = NULL;
1904 			ipmi_unlock_xmit_msgs(intf, run_to_completion, &flags);
1905 			/*
1906 			 * Something may have been added to the transmit
1907 			 * queue, so schedule a check for that.
1908 			 */
1909 			queue_work(system_wq, &intf->smi_work);
1910 		}
1911 	}
1912 	return rv;
1913 }
1914 
1915 static bool is_maintenance_mode_cmd(struct kernel_ipmi_msg *msg)
1916 {
1917 	return (((msg->netfn == IPMI_NETFN_APP_REQUEST)
1918 		 && ((msg->cmd == IPMI_COLD_RESET_CMD)
1919 		     || (msg->cmd == IPMI_WARM_RESET_CMD)))
1920 		|| (msg->netfn == IPMI_NETFN_FIRMWARE_REQUEST));
1921 }
1922 
1923 static int i_ipmi_req_sysintf(struct ipmi_smi        *intf,
1924 			      struct ipmi_addr       *addr,
1925 			      long                   msgid,
1926 			      struct kernel_ipmi_msg *msg,
1927 			      struct ipmi_smi_msg    *smi_msg,
1928 			      struct ipmi_recv_msg   *recv_msg,
1929 			      int                    retries,
1930 			      unsigned int           retry_time_ms)
1931 {
1932 	struct ipmi_system_interface_addr *smi_addr;
1933 
1934 	if (msg->netfn & 1)
1935 		/* Responses are not allowed to the SMI. */
1936 		return -EINVAL;
1937 
1938 	smi_addr = (struct ipmi_system_interface_addr *) addr;
1939 	if (smi_addr->lun > 3) {
1940 		ipmi_inc_stat(intf, sent_invalid_commands);
1941 		return -EINVAL;
1942 	}
1943 
1944 	memcpy(&recv_msg->addr, smi_addr, sizeof(*smi_addr));
1945 
1946 	if ((msg->netfn == IPMI_NETFN_APP_REQUEST)
1947 	    && ((msg->cmd == IPMI_SEND_MSG_CMD)
1948 		|| (msg->cmd == IPMI_GET_MSG_CMD)
1949 		|| (msg->cmd == IPMI_READ_EVENT_MSG_BUFFER_CMD))) {
1950 		/*
1951 		 * We don't let the user do these, since we manage
1952 		 * the sequence numbers.
1953 		 */
1954 		ipmi_inc_stat(intf, sent_invalid_commands);
1955 		return -EINVAL;
1956 	}
1957 
1958 	if (is_maintenance_mode_cmd(msg)) {
1959 		unsigned long flags;
1960 		int newst;
1961 
1962 		if (msg->netfn == IPMI_NETFN_FIRMWARE_REQUEST)
1963 			newst = IPMI_MAINTENANCE_MODE_STATE_FIRMWARE;
1964 		else
1965 			newst = IPMI_MAINTENANCE_MODE_STATE_RESET;
1966 
1967 		spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
1968 		intf->auto_maintenance_timeout = maintenance_mode_timeout_ms;
1969 		if (!intf->maintenance_mode
1970 				&& intf->maintenance_mode_state < newst) {
1971 			intf->maintenance_mode_state = newst;
1972 			maintenance_mode_update(intf);
1973 			mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
1974 		}
1975 		spin_unlock_irqrestore(&intf->maintenance_mode_lock,
1976 				       flags);
1977 	}
1978 
1979 	if (msg->data_len + 2 > IPMI_MAX_MSG_LENGTH) {
1980 		ipmi_inc_stat(intf, sent_invalid_commands);
1981 		return -EMSGSIZE;
1982 	}
1983 
1984 	smi_msg->data[0] = (msg->netfn << 2) | (smi_addr->lun & 0x3);
1985 	smi_msg->data[1] = msg->cmd;
1986 	smi_msg->msgid = msgid;
1987 	smi_msg->recv_msg = recv_msg;
1988 	if (msg->data_len > 0)
1989 		memcpy(&smi_msg->data[2], msg->data, msg->data_len);
1990 	smi_msg->data_size = msg->data_len + 2;
1991 	ipmi_inc_stat(intf, sent_local_commands);
1992 
1993 	return 0;
1994 }
1995 
1996 static int i_ipmi_req_ipmb(struct ipmi_smi        *intf,
1997 			   struct ipmi_addr       *addr,
1998 			   long                   msgid,
1999 			   struct kernel_ipmi_msg *msg,
2000 			   struct ipmi_smi_msg    *smi_msg,
2001 			   struct ipmi_recv_msg   *recv_msg,
2002 			   unsigned char          source_address,
2003 			   unsigned char          source_lun,
2004 			   int                    retries,
2005 			   unsigned int           retry_time_ms)
2006 {
2007 	struct ipmi_ipmb_addr *ipmb_addr;
2008 	unsigned char ipmb_seq;
2009 	long seqid;
2010 	int broadcast = 0;
2011 	struct ipmi_channel *chans;
2012 	int rv = 0;
2013 
2014 	if (addr->channel >= IPMI_MAX_CHANNELS) {
2015 		ipmi_inc_stat(intf, sent_invalid_commands);
2016 		return -EINVAL;
2017 	}
2018 
2019 	chans = READ_ONCE(intf->channel_list)->c;
2020 
2021 	if (chans[addr->channel].medium != IPMI_CHANNEL_MEDIUM_IPMB) {
2022 		ipmi_inc_stat(intf, sent_invalid_commands);
2023 		return -EINVAL;
2024 	}
2025 
2026 	if (addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE) {
2027 		/*
2028 		 * Broadcasts add a zero at the beginning of the
2029 		 * message, but otherwise is the same as an IPMB
2030 		 * address.
2031 		 */
2032 		addr->addr_type = IPMI_IPMB_ADDR_TYPE;
2033 		broadcast = 1;
2034 		retries = 0; /* Don't retry broadcasts. */
2035 	}
2036 
2037 	/*
2038 	 * 9 for the header and 1 for the checksum, plus
2039 	 * possibly one for the broadcast.
2040 	 */
2041 	if ((msg->data_len + 10 + broadcast) > IPMI_MAX_MSG_LENGTH) {
2042 		ipmi_inc_stat(intf, sent_invalid_commands);
2043 		return -EMSGSIZE;
2044 	}
2045 
2046 	ipmb_addr = (struct ipmi_ipmb_addr *) addr;
2047 	if (ipmb_addr->lun > 3) {
2048 		ipmi_inc_stat(intf, sent_invalid_commands);
2049 		return -EINVAL;
2050 	}
2051 
2052 	memcpy(&recv_msg->addr, ipmb_addr, sizeof(*ipmb_addr));
2053 
2054 	if (recv_msg->msg.netfn & 0x1) {
2055 		/*
2056 		 * It's a response, so use the user's sequence
2057 		 * from msgid.
2058 		 */
2059 		ipmi_inc_stat(intf, sent_ipmb_responses);
2060 		format_ipmb_msg(smi_msg, msg, ipmb_addr, msgid,
2061 				msgid, broadcast,
2062 				source_address, source_lun);
2063 
2064 		/*
2065 		 * Save the receive message so we can use it
2066 		 * to deliver the response.
2067 		 */
2068 		smi_msg->recv_msg = recv_msg;
2069 	} else {
2070 		mutex_lock(&intf->seq_lock);
2071 
2072 		if (is_maintenance_mode_cmd(msg))
2073 			intf->ipmb_maintenance_mode_timeout =
2074 				maintenance_mode_timeout_ms;
2075 
2076 		if (intf->ipmb_maintenance_mode_timeout && retry_time_ms == 0)
2077 			/* Different default in maintenance mode */
2078 			retry_time_ms = default_maintenance_retry_ms;
2079 
2080 		/*
2081 		 * Create a sequence number with a 1 second
2082 		 * timeout and 4 retries.
2083 		 */
2084 		rv = intf_next_seq(intf,
2085 				   recv_msg,
2086 				   retry_time_ms,
2087 				   retries,
2088 				   broadcast,
2089 				   &ipmb_seq,
2090 				   &seqid);
2091 		if (rv)
2092 			/*
2093 			 * We have used up all the sequence numbers,
2094 			 * probably, so abort.
2095 			 */
2096 			goto out_err;
2097 
2098 		ipmi_inc_stat(intf, sent_ipmb_commands);
2099 
2100 		/*
2101 		 * Store the sequence number in the message,
2102 		 * so that when the send message response
2103 		 * comes back we can start the timer.
2104 		 */
2105 		format_ipmb_msg(smi_msg, msg, ipmb_addr,
2106 				STORE_SEQ_IN_MSGID(ipmb_seq, seqid),
2107 				ipmb_seq, broadcast,
2108 				source_address, source_lun);
2109 
2110 		/*
2111 		 * Copy the message into the recv message data, so we
2112 		 * can retransmit it later if necessary.
2113 		 */
2114 		memcpy(recv_msg->msg_data, smi_msg->data,
2115 		       smi_msg->data_size);
2116 		recv_msg->msg.data = recv_msg->msg_data;
2117 		recv_msg->msg.data_len = smi_msg->data_size;
2118 
2119 		/*
2120 		 * We don't unlock until here, because we need
2121 		 * to copy the completed message into the
2122 		 * recv_msg before we release the lock.
2123 		 * Otherwise, race conditions may bite us.  I
2124 		 * know that's pretty paranoid, but I prefer
2125 		 * to be correct.
2126 		 */
2127 out_err:
2128 		mutex_unlock(&intf->seq_lock);
2129 	}
2130 
2131 	return rv;
2132 }
2133 
2134 static int i_ipmi_req_ipmb_direct(struct ipmi_smi        *intf,
2135 				  struct ipmi_addr       *addr,
2136 				  long			 msgid,
2137 				  struct kernel_ipmi_msg *msg,
2138 				  struct ipmi_smi_msg    *smi_msg,
2139 				  struct ipmi_recv_msg   *recv_msg,
2140 				  unsigned char          source_lun)
2141 {
2142 	struct ipmi_ipmb_direct_addr *daddr;
2143 	bool is_cmd = !(recv_msg->msg.netfn & 0x1);
2144 
2145 	if (!(intf->handlers->flags & IPMI_SMI_CAN_HANDLE_IPMB_DIRECT))
2146 		return -EAFNOSUPPORT;
2147 
2148 	/* Responses must have a completion code. */
2149 	if (!is_cmd && msg->data_len < 1) {
2150 		ipmi_inc_stat(intf, sent_invalid_commands);
2151 		return -EINVAL;
2152 	}
2153 
2154 	if ((msg->data_len + 4) > IPMI_MAX_MSG_LENGTH) {
2155 		ipmi_inc_stat(intf, sent_invalid_commands);
2156 		return -EMSGSIZE;
2157 	}
2158 
2159 	daddr = (struct ipmi_ipmb_direct_addr *) addr;
2160 	if (daddr->rq_lun > 3 || daddr->rs_lun > 3) {
2161 		ipmi_inc_stat(intf, sent_invalid_commands);
2162 		return -EINVAL;
2163 	}
2164 
2165 	smi_msg->type = IPMI_SMI_MSG_TYPE_IPMB_DIRECT;
2166 	smi_msg->msgid = msgid;
2167 
2168 	if (is_cmd) {
2169 		smi_msg->data[0] = msg->netfn << 2 | daddr->rs_lun;
2170 		smi_msg->data[2] = recv_msg->msgid << 2 | daddr->rq_lun;
2171 	} else {
2172 		smi_msg->data[0] = msg->netfn << 2 | daddr->rq_lun;
2173 		smi_msg->data[2] = recv_msg->msgid << 2 | daddr->rs_lun;
2174 	}
2175 	smi_msg->data[1] = daddr->slave_addr;
2176 	smi_msg->data[3] = msg->cmd;
2177 
2178 	memcpy(smi_msg->data + 4, msg->data, msg->data_len);
2179 	smi_msg->data_size = msg->data_len + 4;
2180 
2181 	smi_msg->recv_msg = recv_msg;
2182 
2183 	return 0;
2184 }
2185 
2186 static int i_ipmi_req_lan(struct ipmi_smi        *intf,
2187 			  struct ipmi_addr       *addr,
2188 			  long                   msgid,
2189 			  struct kernel_ipmi_msg *msg,
2190 			  struct ipmi_smi_msg    *smi_msg,
2191 			  struct ipmi_recv_msg   *recv_msg,
2192 			  unsigned char          source_lun,
2193 			  int                    retries,
2194 			  unsigned int           retry_time_ms)
2195 {
2196 	struct ipmi_lan_addr  *lan_addr;
2197 	unsigned char ipmb_seq;
2198 	long seqid;
2199 	struct ipmi_channel *chans;
2200 	int rv = 0;
2201 
2202 	if (addr->channel >= IPMI_MAX_CHANNELS) {
2203 		ipmi_inc_stat(intf, sent_invalid_commands);
2204 		return -EINVAL;
2205 	}
2206 
2207 	chans = READ_ONCE(intf->channel_list)->c;
2208 
2209 	if ((chans[addr->channel].medium
2210 				!= IPMI_CHANNEL_MEDIUM_8023LAN)
2211 			&& (chans[addr->channel].medium
2212 			    != IPMI_CHANNEL_MEDIUM_ASYNC)) {
2213 		ipmi_inc_stat(intf, sent_invalid_commands);
2214 		return -EINVAL;
2215 	}
2216 
2217 	/* 11 for the header and 1 for the checksum. */
2218 	if ((msg->data_len + 12) > IPMI_MAX_MSG_LENGTH) {
2219 		ipmi_inc_stat(intf, sent_invalid_commands);
2220 		return -EMSGSIZE;
2221 	}
2222 
2223 	lan_addr = (struct ipmi_lan_addr *) addr;
2224 	if (lan_addr->lun > 3) {
2225 		ipmi_inc_stat(intf, sent_invalid_commands);
2226 		return -EINVAL;
2227 	}
2228 
2229 	memcpy(&recv_msg->addr, lan_addr, sizeof(*lan_addr));
2230 
2231 	if (recv_msg->msg.netfn & 0x1) {
2232 		/*
2233 		 * It's a response, so use the user's sequence
2234 		 * from msgid.
2235 		 */
2236 		ipmi_inc_stat(intf, sent_lan_responses);
2237 		format_lan_msg(smi_msg, msg, lan_addr, msgid,
2238 			       msgid, source_lun);
2239 
2240 		/*
2241 		 * Save the receive message so we can use it
2242 		 * to deliver the response.
2243 		 */
2244 		smi_msg->recv_msg = recv_msg;
2245 	} else {
2246 		mutex_lock(&intf->seq_lock);
2247 
2248 		/*
2249 		 * Create a sequence number with a 1 second
2250 		 * timeout and 4 retries.
2251 		 */
2252 		rv = intf_next_seq(intf,
2253 				   recv_msg,
2254 				   retry_time_ms,
2255 				   retries,
2256 				   0,
2257 				   &ipmb_seq,
2258 				   &seqid);
2259 		if (rv)
2260 			/*
2261 			 * We have used up all the sequence numbers,
2262 			 * probably, so abort.
2263 			 */
2264 			goto out_err;
2265 
2266 		ipmi_inc_stat(intf, sent_lan_commands);
2267 
2268 		/*
2269 		 * Store the sequence number in the message,
2270 		 * so that when the send message response
2271 		 * comes back we can start the timer.
2272 		 */
2273 		format_lan_msg(smi_msg, msg, lan_addr,
2274 			       STORE_SEQ_IN_MSGID(ipmb_seq, seqid),
2275 			       ipmb_seq, source_lun);
2276 
2277 		/*
2278 		 * Copy the message into the recv message data, so we
2279 		 * can retransmit it later if necessary.
2280 		 */
2281 		memcpy(recv_msg->msg_data, smi_msg->data,
2282 		       smi_msg->data_size);
2283 		recv_msg->msg.data = recv_msg->msg_data;
2284 		recv_msg->msg.data_len = smi_msg->data_size;
2285 
2286 		/*
2287 		 * We don't unlock until here, because we need
2288 		 * to copy the completed message into the
2289 		 * recv_msg before we release the lock.
2290 		 * Otherwise, race conditions may bite us.  I
2291 		 * know that's pretty paranoid, but I prefer
2292 		 * to be correct.
2293 		 */
2294 out_err:
2295 		mutex_unlock(&intf->seq_lock);
2296 	}
2297 
2298 	return rv;
2299 }
2300 
2301 /*
2302  * Separate from ipmi_request so that the user does not have to be
2303  * supplied in certain circumstances (mainly at panic time).  If
2304  * messages are supplied, they will be freed, even if an error
2305  * occurs.
2306  */
2307 static int i_ipmi_request(struct ipmi_user     *user,
2308 			  struct ipmi_smi      *intf,
2309 			  struct ipmi_addr     *addr,
2310 			  long                 msgid,
2311 			  struct kernel_ipmi_msg *msg,
2312 			  void                 *user_msg_data,
2313 			  void                 *supplied_smi,
2314 			  struct ipmi_recv_msg *supplied_recv,
2315 			  int                  priority,
2316 			  unsigned char        source_address,
2317 			  unsigned char        source_lun,
2318 			  int                  retries,
2319 			  unsigned int         retry_time_ms)
2320 {
2321 	struct ipmi_smi_msg *smi_msg;
2322 	struct ipmi_recv_msg *recv_msg;
2323 	int run_to_completion = READ_ONCE(intf->run_to_completion);
2324 	int rv = 0;
2325 	bool in_seq_table = false;
2326 
2327 	if (supplied_recv) {
2328 		recv_msg = supplied_recv;
2329 		recv_msg->user = user;
2330 		if (user) {
2331 			atomic_inc(&user->nr_msgs);
2332 			/* The put happens when the message is freed. */
2333 			kref_get(&user->refcount);
2334 		}
2335 	} else {
2336 		recv_msg = ipmi_alloc_recv_msg(user);
2337 		if (IS_ERR(recv_msg))
2338 			return PTR_ERR(recv_msg);
2339 	}
2340 	recv_msg->user_msg_data = user_msg_data;
2341 
2342 	if (supplied_smi)
2343 		smi_msg = supplied_smi;
2344 	else {
2345 		smi_msg = ipmi_alloc_smi_msg();
2346 		if (smi_msg == NULL) {
2347 			if (!supplied_recv)
2348 				ipmi_free_recv_msg(recv_msg);
2349 			else if (recv_msg->user) {
2350 				atomic_dec(&recv_msg->user->nr_msgs);
2351 				kref_put(&recv_msg->user->refcount, free_ipmi_user);
2352 			}
2353 			return -ENOMEM;
2354 		}
2355 	}
2356 
2357 	if (!run_to_completion)
2358 		mutex_lock(&intf->users_mutex);
2359 	if (intf->maintenance_mode_state == IPMI_MAINTENANCE_MODE_STATE_RESET) {
2360 		/* No messages while the BMC is in reset. */
2361 		rv = -EBUSY;
2362 		goto out_err;
2363 	}
2364 	if (intf->in_shutdown) {
2365 		rv = -ENODEV;
2366 		goto out_err;
2367 	}
2368 
2369 	recv_msg->msgid = msgid;
2370 	/*
2371 	 * Store the message to send in the receive message so timeout
2372 	 * responses can get the proper response data.
2373 	 */
2374 	recv_msg->msg = *msg;
2375 
2376 	if (addr->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
2377 		rv = i_ipmi_req_sysintf(intf, addr, msgid, msg, smi_msg,
2378 					recv_msg, retries, retry_time_ms);
2379 	} else if (is_ipmb_addr(addr) || is_ipmb_bcast_addr(addr)) {
2380 		rv = i_ipmi_req_ipmb(intf, addr, msgid, msg, smi_msg, recv_msg,
2381 				     source_address, source_lun,
2382 				     retries, retry_time_ms);
2383 		in_seq_table = true;
2384 	} else if (is_ipmb_direct_addr(addr)) {
2385 		rv = i_ipmi_req_ipmb_direct(intf, addr, msgid, msg, smi_msg,
2386 					    recv_msg, source_lun);
2387 	} else if (is_lan_addr(addr)) {
2388 		rv = i_ipmi_req_lan(intf, addr, msgid, msg, smi_msg, recv_msg,
2389 				    source_lun, retries, retry_time_ms);
2390 		in_seq_table = true;
2391 	} else {
2392 		/* Unknown address type. */
2393 		ipmi_inc_stat(intf, sent_invalid_commands);
2394 		rv = -EINVAL;
2395 	}
2396 
2397 	if (!rv) {
2398 		dev_dbg(intf->si_dev, "Send: %*ph\n",
2399 			smi_msg->data_size, smi_msg->data);
2400 
2401 		rv = smi_send(intf, intf->handlers, smi_msg, priority);
2402 		if (rv != IPMI_CC_NO_ERROR)
2403 			/* smi_send() returns an IPMI err, return a Linux one. */
2404 			rv = -EIO;
2405 		if (rv && in_seq_table) {
2406 			/*
2407 			 * If it's in the sequence table, it will be
2408 			 * retried later, so ignore errors.
2409 			 */
2410 			rv = 0;
2411 			/* But we need to fix the timeout. */
2412 			intf_start_seq_timer(intf, smi_msg->msgid);
2413 			ipmi_free_smi_msg(smi_msg);
2414 			smi_msg = NULL;
2415 		}
2416 	}
2417 out_err:
2418 	if (!run_to_completion)
2419 		mutex_unlock(&intf->users_mutex);
2420 
2421 	if (rv) {
2422 		if (!supplied_smi)
2423 			ipmi_free_smi_msg(smi_msg);
2424 		if (!supplied_recv)
2425 			ipmi_free_recv_msg(recv_msg);
2426 		else if (recv_msg->user) {
2427 			atomic_dec(&recv_msg->user->nr_msgs);
2428 			kref_put(&recv_msg->user->refcount, free_ipmi_user);
2429 		}
2430 	}
2431 	return rv;
2432 }
2433 
2434 static int check_addr(struct ipmi_smi  *intf,
2435 		      struct ipmi_addr *addr,
2436 		      unsigned char    *saddr,
2437 		      unsigned char    *lun)
2438 {
2439 	if (addr->channel >= IPMI_MAX_CHANNELS)
2440 		return -EINVAL;
2441 	addr->channel = array_index_nospec(addr->channel, IPMI_MAX_CHANNELS);
2442 	*lun = intf->addrinfo[addr->channel].lun;
2443 	*saddr = intf->addrinfo[addr->channel].address;
2444 	return 0;
2445 }
2446 
2447 int ipmi_request_settime(struct ipmi_user *user,
2448 			 struct ipmi_addr *addr,
2449 			 long             msgid,
2450 			 struct kernel_ipmi_msg  *msg,
2451 			 void             *user_msg_data,
2452 			 int              priority,
2453 			 int              retries,
2454 			 unsigned int     retry_time_ms)
2455 {
2456 	unsigned char saddr = 0, lun = 0;
2457 	int rv;
2458 
2459 	if (!user)
2460 		return -EINVAL;
2461 
2462 	user = acquire_ipmi_user(user);
2463 	if (!user)
2464 		return -ENODEV;
2465 
2466 	rv = check_addr(user->intf, addr, &saddr, &lun);
2467 	if (!rv)
2468 		rv = i_ipmi_request(user,
2469 				    user->intf,
2470 				    addr,
2471 				    msgid,
2472 				    msg,
2473 				    user_msg_data,
2474 				    NULL, NULL,
2475 				    priority,
2476 				    saddr,
2477 				    lun,
2478 				    retries,
2479 				    retry_time_ms);
2480 
2481 	release_ipmi_user(user);
2482 	return rv;
2483 }
2484 EXPORT_SYMBOL(ipmi_request_settime);
2485 
2486 int ipmi_request_supply_msgs(struct ipmi_user     *user,
2487 			     struct ipmi_addr     *addr,
2488 			     long                 msgid,
2489 			     struct kernel_ipmi_msg *msg,
2490 			     void                 *user_msg_data,
2491 			     void                 *supplied_smi,
2492 			     struct ipmi_recv_msg *supplied_recv,
2493 			     int                  priority)
2494 {
2495 	unsigned char saddr = 0, lun = 0;
2496 	int rv;
2497 
2498 	if (!user)
2499 		return -EINVAL;
2500 
2501 	user = acquire_ipmi_user(user);
2502 	if (!user)
2503 		return -ENODEV;
2504 
2505 	rv = check_addr(user->intf, addr, &saddr, &lun);
2506 	if (!rv)
2507 		rv = i_ipmi_request(user,
2508 				    user->intf,
2509 				    addr,
2510 				    msgid,
2511 				    msg,
2512 				    user_msg_data,
2513 				    supplied_smi,
2514 				    supplied_recv,
2515 				    priority,
2516 				    saddr,
2517 				    lun,
2518 				    -1, 0);
2519 
2520 	release_ipmi_user(user);
2521 	return rv;
2522 }
2523 EXPORT_SYMBOL(ipmi_request_supply_msgs);
2524 
2525 static void bmc_device_id_handler(struct ipmi_smi *intf,
2526 				  struct ipmi_recv_msg *msg)
2527 {
2528 	int rv;
2529 
2530 	if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
2531 			|| (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE)
2532 			|| (msg->msg.cmd != IPMI_GET_DEVICE_ID_CMD)) {
2533 		dev_warn(intf->si_dev,
2534 			 "invalid device_id msg: addr_type=%d netfn=%x cmd=%x\n",
2535 			 msg->addr.addr_type, msg->msg.netfn, msg->msg.cmd);
2536 		return;
2537 	}
2538 
2539 	if (msg->msg.data[0]) {
2540 		dev_warn(intf->si_dev, "device id fetch failed: 0x%2.2x\n",
2541 			 msg->msg.data[0]);
2542 		intf->bmc->dyn_id_set = 0;
2543 		goto out;
2544 	}
2545 
2546 	rv = ipmi_demangle_device_id(msg->msg.netfn, msg->msg.cmd,
2547 			msg->msg.data, msg->msg.data_len, &intf->bmc->fetch_id);
2548 	if (rv) {
2549 		dev_warn(intf->si_dev, "device id demangle failed: %d\n", rv);
2550 		/* record completion code when error */
2551 		intf->bmc->cc = msg->msg.data[0];
2552 		intf->bmc->dyn_id_set = 0;
2553 	} else {
2554 		/*
2555 		 * Make sure the id data is available before setting
2556 		 * dyn_id_set.
2557 		 */
2558 		smp_wmb();
2559 		intf->bmc->dyn_id_set = 1;
2560 	}
2561 out:
2562 	wake_up(&intf->waitq);
2563 }
2564 
2565 static int
2566 send_get_device_id_cmd(struct ipmi_smi *intf)
2567 {
2568 	struct ipmi_system_interface_addr si;
2569 	struct kernel_ipmi_msg msg;
2570 
2571 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
2572 	si.channel = IPMI_BMC_CHANNEL;
2573 	si.lun = 0;
2574 
2575 	msg.netfn = IPMI_NETFN_APP_REQUEST;
2576 	msg.cmd = IPMI_GET_DEVICE_ID_CMD;
2577 	msg.data = NULL;
2578 	msg.data_len = 0;
2579 
2580 	return i_ipmi_request(NULL,
2581 			      intf,
2582 			      (struct ipmi_addr *) &si,
2583 			      0,
2584 			      &msg,
2585 			      intf,
2586 			      NULL,
2587 			      NULL,
2588 			      0,
2589 			      intf->addrinfo[0].address,
2590 			      intf->addrinfo[0].lun,
2591 			      -1, 0);
2592 }
2593 
2594 static int __get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc)
2595 {
2596 	int rv;
2597 	unsigned int retry_count = 0;
2598 
2599 	intf->null_user_handler = bmc_device_id_handler;
2600 
2601 retry:
2602 	bmc->cc = 0;
2603 	bmc->dyn_id_set = 2;
2604 
2605 	rv = send_get_device_id_cmd(intf);
2606 	if (rv)
2607 		goto out_reset_handler;
2608 
2609 	wait_event(intf->waitq, bmc->dyn_id_set != 2);
2610 
2611 	if (!bmc->dyn_id_set) {
2612 		if (bmc->cc != IPMI_CC_NO_ERROR &&
2613 		    ++retry_count <= GET_DEVICE_ID_MAX_RETRY) {
2614 			msleep(500);
2615 			dev_warn(intf->si_dev,
2616 			    "BMC returned 0x%2.2x, retry get bmc device id\n",
2617 			    bmc->cc);
2618 			goto retry;
2619 		}
2620 
2621 		rv = -EIO; /* Something went wrong in the fetch. */
2622 	}
2623 
2624 	/* dyn_id_set makes the id data available. */
2625 	smp_rmb();
2626 
2627 out_reset_handler:
2628 	intf->null_user_handler = NULL;
2629 
2630 	return rv;
2631 }
2632 
2633 /*
2634  * Fetch the device id for the bmc/interface.  You must pass in either
2635  * bmc or intf, this code will get the other one.  If the data has
2636  * been recently fetched, this will just use the cached data.  Otherwise
2637  * it will run a new fetch.
2638  *
2639  * Except for the first time this is called (in ipmi_add_smi()),
2640  * this will always return good data;
2641  */
2642 static int __bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
2643 			       struct ipmi_device_id *id,
2644 			       bool *guid_set, guid_t *guid, int intf_num)
2645 {
2646 	int rv = 0;
2647 	int prev_dyn_id_set, prev_guid_set;
2648 	bool intf_set = intf != NULL;
2649 
2650 	if (!intf) {
2651 		mutex_lock(&bmc->dyn_mutex);
2652 retry_bmc_lock:
2653 		if (list_empty(&bmc->intfs)) {
2654 			mutex_unlock(&bmc->dyn_mutex);
2655 			return -ENOENT;
2656 		}
2657 		intf = list_first_entry(&bmc->intfs, struct ipmi_smi,
2658 					bmc_link);
2659 		kref_get(&intf->refcount);
2660 		mutex_unlock(&bmc->dyn_mutex);
2661 		mutex_lock(&intf->bmc_reg_mutex);
2662 		mutex_lock(&bmc->dyn_mutex);
2663 		if (intf != list_first_entry(&bmc->intfs, struct ipmi_smi,
2664 					     bmc_link)) {
2665 			mutex_unlock(&intf->bmc_reg_mutex);
2666 			kref_put(&intf->refcount, intf_free);
2667 			goto retry_bmc_lock;
2668 		}
2669 	} else {
2670 		mutex_lock(&intf->bmc_reg_mutex);
2671 		bmc = intf->bmc;
2672 		mutex_lock(&bmc->dyn_mutex);
2673 		kref_get(&intf->refcount);
2674 	}
2675 
2676 	/* If we have a valid and current ID, just return that. */
2677 	if (intf->in_bmc_register ||
2678 	    (bmc->dyn_id_set && time_is_after_jiffies(bmc->dyn_id_expiry)))
2679 		goto out_noprocessing;
2680 
2681 	/* Don't allow sysfs access when in maintenance mode. */
2682 	if (intf->maintenance_mode_state) {
2683 		rv = -EBUSY;
2684 		goto out_noprocessing;
2685 	}
2686 
2687 	prev_guid_set = bmc->dyn_guid_set;
2688 	__get_guid(intf);
2689 
2690 	prev_dyn_id_set = bmc->dyn_id_set;
2691 	rv = __get_device_id(intf, bmc);
2692 	if (rv)
2693 		goto out;
2694 
2695 	/*
2696 	 * The guid, device id, manufacturer id, and product id should
2697 	 * not change on a BMC.  If it does we have to do some dancing.
2698 	 */
2699 	if (!intf->bmc_registered
2700 	    || (!prev_guid_set && bmc->dyn_guid_set)
2701 	    || (!prev_dyn_id_set && bmc->dyn_id_set)
2702 	    || (prev_guid_set && bmc->dyn_guid_set
2703 		&& !guid_equal(&bmc->guid, &bmc->fetch_guid))
2704 	    || bmc->id.device_id != bmc->fetch_id.device_id
2705 	    || bmc->id.manufacturer_id != bmc->fetch_id.manufacturer_id
2706 	    || bmc->id.product_id != bmc->fetch_id.product_id) {
2707 		struct ipmi_device_id id = bmc->fetch_id;
2708 		int guid_set = bmc->dyn_guid_set;
2709 		guid_t guid;
2710 
2711 		guid = bmc->fetch_guid;
2712 		mutex_unlock(&bmc->dyn_mutex);
2713 
2714 		__ipmi_bmc_unregister(intf);
2715 		/* Fill in the temporary BMC for good measure. */
2716 		intf->bmc->id = id;
2717 		intf->bmc->dyn_guid_set = guid_set;
2718 		intf->bmc->guid = guid;
2719 		if (__ipmi_bmc_register(intf, &id, guid_set, &guid, intf_num))
2720 			need_waiter(intf); /* Retry later on an error. */
2721 		else
2722 			__scan_channels(intf, &id, false);
2723 
2724 
2725 		if (!intf_set) {
2726 			/*
2727 			 * We weren't given the interface on the
2728 			 * command line, so restart the operation on
2729 			 * the next interface for the BMC.
2730 			 */
2731 			mutex_unlock(&intf->bmc_reg_mutex);
2732 			mutex_lock(&bmc->dyn_mutex);
2733 			goto retry_bmc_lock;
2734 		}
2735 
2736 		/* We have a new BMC, set it up. */
2737 		bmc = intf->bmc;
2738 		mutex_lock(&bmc->dyn_mutex);
2739 		goto out_noprocessing;
2740 	} else if (memcmp(&bmc->fetch_id, &bmc->id, sizeof(bmc->id)))
2741 		/* Version info changes, scan the channels again. */
2742 		__scan_channels(intf, &bmc->fetch_id, true);
2743 
2744 	bmc->dyn_id_expiry = jiffies + IPMI_DYN_DEV_ID_EXPIRY;
2745 
2746 out:
2747 	if (rv && prev_dyn_id_set) {
2748 		rv = 0; /* Ignore failures if we have previous data. */
2749 		bmc->dyn_id_set = prev_dyn_id_set;
2750 	}
2751 	if (!rv) {
2752 		bmc->id = bmc->fetch_id;
2753 		if (bmc->dyn_guid_set)
2754 			bmc->guid = bmc->fetch_guid;
2755 		else if (prev_guid_set)
2756 			/*
2757 			 * The guid used to be valid and it failed to fetch,
2758 			 * just use the cached value.
2759 			 */
2760 			bmc->dyn_guid_set = prev_guid_set;
2761 	}
2762 out_noprocessing:
2763 	if (!rv) {
2764 		if (id)
2765 			*id = bmc->id;
2766 
2767 		if (guid_set)
2768 			*guid_set = bmc->dyn_guid_set;
2769 
2770 		if (guid && bmc->dyn_guid_set)
2771 			*guid =  bmc->guid;
2772 	}
2773 
2774 	mutex_unlock(&bmc->dyn_mutex);
2775 	mutex_unlock(&intf->bmc_reg_mutex);
2776 
2777 	kref_put(&intf->refcount, intf_free);
2778 	return rv;
2779 }
2780 
2781 static int bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
2782 			     struct ipmi_device_id *id,
2783 			     bool *guid_set, guid_t *guid)
2784 {
2785 	return __bmc_get_device_id(intf, bmc, id, guid_set, guid, -1);
2786 }
2787 
2788 static ssize_t device_id_show(struct device *dev,
2789 			      struct device_attribute *attr,
2790 			      char *buf)
2791 {
2792 	struct bmc_device *bmc = to_bmc_device(dev);
2793 	struct ipmi_device_id id;
2794 	int rv;
2795 
2796 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2797 	if (rv)
2798 		return rv;
2799 
2800 	return sysfs_emit(buf, "%u\n", id.device_id);
2801 }
2802 static DEVICE_ATTR_RO(device_id);
2803 
2804 static ssize_t provides_device_sdrs_show(struct device *dev,
2805 					 struct device_attribute *attr,
2806 					 char *buf)
2807 {
2808 	struct bmc_device *bmc = to_bmc_device(dev);
2809 	struct ipmi_device_id id;
2810 	int rv;
2811 
2812 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2813 	if (rv)
2814 		return rv;
2815 
2816 	return sysfs_emit(buf, "%u\n", (id.device_revision & 0x80) >> 7);
2817 }
2818 static DEVICE_ATTR_RO(provides_device_sdrs);
2819 
2820 static ssize_t revision_show(struct device *dev, struct device_attribute *attr,
2821 			     char *buf)
2822 {
2823 	struct bmc_device *bmc = to_bmc_device(dev);
2824 	struct ipmi_device_id id;
2825 	int rv;
2826 
2827 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2828 	if (rv)
2829 		return rv;
2830 
2831 	return sysfs_emit(buf, "%u\n", id.device_revision & 0x0F);
2832 }
2833 static DEVICE_ATTR_RO(revision);
2834 
2835 static ssize_t firmware_revision_show(struct device *dev,
2836 				      struct device_attribute *attr,
2837 				      char *buf)
2838 {
2839 	struct bmc_device *bmc = to_bmc_device(dev);
2840 	struct ipmi_device_id id;
2841 	int rv;
2842 
2843 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2844 	if (rv)
2845 		return rv;
2846 
2847 	return sysfs_emit(buf, "%u.%x\n", id.firmware_revision_1,
2848 			id.firmware_revision_2);
2849 }
2850 static DEVICE_ATTR_RO(firmware_revision);
2851 
2852 static ssize_t ipmi_version_show(struct device *dev,
2853 				 struct device_attribute *attr,
2854 				 char *buf)
2855 {
2856 	struct bmc_device *bmc = to_bmc_device(dev);
2857 	struct ipmi_device_id id;
2858 	int rv;
2859 
2860 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2861 	if (rv)
2862 		return rv;
2863 
2864 	return sysfs_emit(buf, "%u.%u\n",
2865 			ipmi_version_major(&id),
2866 			ipmi_version_minor(&id));
2867 }
2868 static DEVICE_ATTR_RO(ipmi_version);
2869 
2870 static ssize_t add_dev_support_show(struct device *dev,
2871 				    struct device_attribute *attr,
2872 				    char *buf)
2873 {
2874 	struct bmc_device *bmc = to_bmc_device(dev);
2875 	struct ipmi_device_id id;
2876 	int rv;
2877 
2878 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2879 	if (rv)
2880 		return rv;
2881 
2882 	return sysfs_emit(buf, "0x%02x\n", id.additional_device_support);
2883 }
2884 static DEVICE_ATTR(additional_device_support, S_IRUGO, add_dev_support_show,
2885 		   NULL);
2886 
2887 static ssize_t manufacturer_id_show(struct device *dev,
2888 				    struct device_attribute *attr,
2889 				    char *buf)
2890 {
2891 	struct bmc_device *bmc = to_bmc_device(dev);
2892 	struct ipmi_device_id id;
2893 	int rv;
2894 
2895 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2896 	if (rv)
2897 		return rv;
2898 
2899 	return sysfs_emit(buf, "0x%6.6x\n", id.manufacturer_id);
2900 }
2901 static DEVICE_ATTR_RO(manufacturer_id);
2902 
2903 static ssize_t product_id_show(struct device *dev,
2904 			       struct device_attribute *attr,
2905 			       char *buf)
2906 {
2907 	struct bmc_device *bmc = to_bmc_device(dev);
2908 	struct ipmi_device_id id;
2909 	int rv;
2910 
2911 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2912 	if (rv)
2913 		return rv;
2914 
2915 	return sysfs_emit(buf, "0x%4.4x\n", id.product_id);
2916 }
2917 static DEVICE_ATTR_RO(product_id);
2918 
2919 static ssize_t aux_firmware_rev_show(struct device *dev,
2920 				     struct device_attribute *attr,
2921 				     char *buf)
2922 {
2923 	struct bmc_device *bmc = to_bmc_device(dev);
2924 	struct ipmi_device_id id;
2925 	int rv;
2926 
2927 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2928 	if (rv)
2929 		return rv;
2930 
2931 	return sysfs_emit(buf, "0x%02x 0x%02x 0x%02x 0x%02x\n",
2932 			id.aux_firmware_revision[3],
2933 			id.aux_firmware_revision[2],
2934 			id.aux_firmware_revision[1],
2935 			id.aux_firmware_revision[0]);
2936 }
2937 static DEVICE_ATTR(aux_firmware_revision, S_IRUGO, aux_firmware_rev_show, NULL);
2938 
2939 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
2940 			 char *buf)
2941 {
2942 	struct bmc_device *bmc = to_bmc_device(dev);
2943 	bool guid_set;
2944 	guid_t guid;
2945 	int rv;
2946 
2947 	rv = bmc_get_device_id(NULL, bmc, NULL, &guid_set, &guid);
2948 	if (rv)
2949 		return rv;
2950 	if (!guid_set)
2951 		return -ENOENT;
2952 
2953 	return sysfs_emit(buf, "%pUl\n", &guid);
2954 }
2955 static DEVICE_ATTR_RO(guid);
2956 
2957 static struct attribute *bmc_dev_attrs[] = {
2958 	&dev_attr_device_id.attr,
2959 	&dev_attr_provides_device_sdrs.attr,
2960 	&dev_attr_revision.attr,
2961 	&dev_attr_firmware_revision.attr,
2962 	&dev_attr_ipmi_version.attr,
2963 	&dev_attr_additional_device_support.attr,
2964 	&dev_attr_manufacturer_id.attr,
2965 	&dev_attr_product_id.attr,
2966 	&dev_attr_aux_firmware_revision.attr,
2967 	&dev_attr_guid.attr,
2968 	NULL
2969 };
2970 
2971 static umode_t bmc_dev_attr_is_visible(struct kobject *kobj,
2972 				       struct attribute *attr, int idx)
2973 {
2974 	struct device *dev = kobj_to_dev(kobj);
2975 	struct bmc_device *bmc = to_bmc_device(dev);
2976 	umode_t mode = attr->mode;
2977 	int rv;
2978 
2979 	if (attr == &dev_attr_aux_firmware_revision.attr) {
2980 		struct ipmi_device_id id;
2981 
2982 		rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2983 		return (!rv && id.aux_firmware_revision_set) ? mode : 0;
2984 	}
2985 	if (attr == &dev_attr_guid.attr) {
2986 		bool guid_set;
2987 
2988 		rv = bmc_get_device_id(NULL, bmc, NULL, &guid_set, NULL);
2989 		return (!rv && guid_set) ? mode : 0;
2990 	}
2991 	return mode;
2992 }
2993 
2994 static const struct attribute_group bmc_dev_attr_group = {
2995 	.attrs		= bmc_dev_attrs,
2996 	.is_visible	= bmc_dev_attr_is_visible,
2997 };
2998 
2999 static const struct attribute_group *bmc_dev_attr_groups[] = {
3000 	&bmc_dev_attr_group,
3001 	NULL
3002 };
3003 
3004 static const struct device_type bmc_device_type = {
3005 	.groups		= bmc_dev_attr_groups,
3006 };
3007 
3008 static int __find_bmc_guid(struct device *dev, const void *data)
3009 {
3010 	const guid_t *guid = data;
3011 	struct bmc_device *bmc;
3012 	int rv;
3013 
3014 	if (dev->type != &bmc_device_type)
3015 		return 0;
3016 
3017 	bmc = to_bmc_device(dev);
3018 	rv = bmc->dyn_guid_set && guid_equal(&bmc->guid, guid);
3019 	if (rv)
3020 		rv = kref_get_unless_zero(&bmc->usecount);
3021 	return rv;
3022 }
3023 
3024 /*
3025  * Returns with the bmc's usecount incremented, if it is non-NULL.
3026  */
3027 static struct bmc_device *ipmi_find_bmc_guid(struct device_driver *drv,
3028 					     guid_t *guid)
3029 {
3030 	struct device *dev;
3031 	struct bmc_device *bmc = NULL;
3032 
3033 	dev = driver_find_device(drv, NULL, guid, __find_bmc_guid);
3034 	if (dev) {
3035 		bmc = to_bmc_device(dev);
3036 		put_device(dev);
3037 	}
3038 	return bmc;
3039 }
3040 
3041 struct prod_dev_id {
3042 	unsigned int  product_id;
3043 	unsigned char device_id;
3044 };
3045 
3046 static int __find_bmc_prod_dev_id(struct device *dev, const void *data)
3047 {
3048 	const struct prod_dev_id *cid = data;
3049 	struct bmc_device *bmc;
3050 	int rv;
3051 
3052 	if (dev->type != &bmc_device_type)
3053 		return 0;
3054 
3055 	bmc = to_bmc_device(dev);
3056 	rv = (bmc->id.product_id == cid->product_id
3057 	      && bmc->id.device_id == cid->device_id);
3058 	if (rv)
3059 		rv = kref_get_unless_zero(&bmc->usecount);
3060 	return rv;
3061 }
3062 
3063 /*
3064  * Returns with the bmc's usecount incremented, if it is non-NULL.
3065  */
3066 static struct bmc_device *ipmi_find_bmc_prod_dev_id(
3067 	struct device_driver *drv,
3068 	unsigned int product_id, unsigned char device_id)
3069 {
3070 	struct prod_dev_id id = {
3071 		.product_id = product_id,
3072 		.device_id = device_id,
3073 	};
3074 	struct device *dev;
3075 	struct bmc_device *bmc = NULL;
3076 
3077 	dev = driver_find_device(drv, NULL, &id, __find_bmc_prod_dev_id);
3078 	if (dev) {
3079 		bmc = to_bmc_device(dev);
3080 		put_device(dev);
3081 	}
3082 	return bmc;
3083 }
3084 
3085 static DEFINE_IDA(ipmi_bmc_ida);
3086 
3087 static void
3088 release_bmc_device(struct device *dev)
3089 {
3090 	kfree(to_bmc_device(dev));
3091 }
3092 
3093 static void cleanup_bmc_work(struct work_struct *work)
3094 {
3095 	struct bmc_device *bmc = container_of(work, struct bmc_device,
3096 					      remove_work);
3097 	int id = bmc->pdev.id; /* Unregister overwrites id */
3098 
3099 	platform_device_unregister(&bmc->pdev);
3100 	ida_free(&ipmi_bmc_ida, id);
3101 }
3102 
3103 static void
3104 cleanup_bmc_device(struct kref *ref)
3105 {
3106 	struct bmc_device *bmc = container_of(ref, struct bmc_device, usecount);
3107 
3108 	/*
3109 	 * Remove the platform device in a work queue to avoid issues
3110 	 * with removing the device attributes while reading a device
3111 	 * attribute.
3112 	 */
3113 	queue_work(bmc_remove_work_wq, &bmc->remove_work);
3114 }
3115 
3116 /*
3117  * Must be called with intf->bmc_reg_mutex held.
3118  */
3119 static void __ipmi_bmc_unregister(struct ipmi_smi *intf)
3120 {
3121 	struct bmc_device *bmc = intf->bmc;
3122 
3123 	if (!intf->bmc_registered)
3124 		return;
3125 
3126 	sysfs_remove_link(&intf->si_dev->kobj, "bmc");
3127 	sysfs_remove_link(&bmc->pdev.dev.kobj, intf->my_dev_name);
3128 	kfree(intf->my_dev_name);
3129 	intf->my_dev_name = NULL;
3130 
3131 	mutex_lock(&bmc->dyn_mutex);
3132 	list_del(&intf->bmc_link);
3133 	mutex_unlock(&bmc->dyn_mutex);
3134 	intf->bmc = &intf->tmp_bmc;
3135 	kref_put(&bmc->usecount, cleanup_bmc_device);
3136 	intf->bmc_registered = false;
3137 }
3138 
3139 static void ipmi_bmc_unregister(struct ipmi_smi *intf)
3140 {
3141 	mutex_lock(&intf->bmc_reg_mutex);
3142 	__ipmi_bmc_unregister(intf);
3143 	mutex_unlock(&intf->bmc_reg_mutex);
3144 }
3145 
3146 /*
3147  * Must be called with intf->bmc_reg_mutex held.
3148  */
3149 static int __ipmi_bmc_register(struct ipmi_smi *intf,
3150 			       struct ipmi_device_id *id,
3151 			       bool guid_set, guid_t *guid, int intf_num)
3152 {
3153 	int               rv;
3154 	struct bmc_device *bmc;
3155 	struct bmc_device *old_bmc;
3156 
3157 	/*
3158 	 * platform_device_register() can cause bmc_reg_mutex to
3159 	 * be claimed because of the is_visible functions of
3160 	 * the attributes.  Eliminate possible recursion and
3161 	 * release the lock.
3162 	 */
3163 	intf->in_bmc_register = true;
3164 	mutex_unlock(&intf->bmc_reg_mutex);
3165 
3166 	/*
3167 	 * Try to find if there is an bmc_device struct
3168 	 * representing the interfaced BMC already
3169 	 */
3170 	mutex_lock(&ipmidriver_mutex);
3171 	if (guid_set)
3172 		old_bmc = ipmi_find_bmc_guid(&ipmidriver.driver, guid);
3173 	else
3174 		old_bmc = ipmi_find_bmc_prod_dev_id(&ipmidriver.driver,
3175 						    id->product_id,
3176 						    id->device_id);
3177 
3178 	/*
3179 	 * If there is already an bmc_device, free the new one,
3180 	 * otherwise register the new BMC device
3181 	 */
3182 	if (old_bmc) {
3183 		bmc = old_bmc;
3184 		/*
3185 		 * Note: old_bmc already has usecount incremented by
3186 		 * the BMC find functions.
3187 		 */
3188 		intf->bmc = old_bmc;
3189 		mutex_lock(&bmc->dyn_mutex);
3190 		list_add_tail(&intf->bmc_link, &bmc->intfs);
3191 		mutex_unlock(&bmc->dyn_mutex);
3192 
3193 		dev_info(intf->si_dev,
3194 			 "interfacing existing BMC (man_id: 0x%6.6x, prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n",
3195 			 bmc->id.manufacturer_id,
3196 			 bmc->id.product_id,
3197 			 bmc->id.device_id);
3198 	} else {
3199 		bmc = kzalloc_obj(*bmc);
3200 		if (!bmc) {
3201 			rv = -ENOMEM;
3202 			goto out;
3203 		}
3204 		INIT_LIST_HEAD(&bmc->intfs);
3205 		mutex_init(&bmc->dyn_mutex);
3206 		INIT_WORK(&bmc->remove_work, cleanup_bmc_work);
3207 
3208 		bmc->id = *id;
3209 		bmc->dyn_id_set = 1;
3210 		bmc->dyn_guid_set = guid_set;
3211 		bmc->guid = *guid;
3212 		bmc->dyn_id_expiry = jiffies + IPMI_DYN_DEV_ID_EXPIRY;
3213 
3214 		bmc->pdev.name = "ipmi_bmc";
3215 
3216 		rv = ida_alloc(&ipmi_bmc_ida, GFP_KERNEL);
3217 		if (rv < 0) {
3218 			kfree(bmc);
3219 			goto out;
3220 		}
3221 
3222 		bmc->pdev.dev.driver = &ipmidriver.driver;
3223 		bmc->pdev.id = rv;
3224 		bmc->pdev.dev.release = release_bmc_device;
3225 		bmc->pdev.dev.type = &bmc_device_type;
3226 		kref_init(&bmc->usecount);
3227 
3228 		intf->bmc = bmc;
3229 		mutex_lock(&bmc->dyn_mutex);
3230 		list_add_tail(&intf->bmc_link, &bmc->intfs);
3231 		mutex_unlock(&bmc->dyn_mutex);
3232 
3233 		rv = platform_device_register(&bmc->pdev);
3234 		if (rv) {
3235 			dev_err(intf->si_dev,
3236 				"Unable to register bmc device: %d\n",
3237 				rv);
3238 			goto out_list_del;
3239 		}
3240 
3241 		dev_info(intf->si_dev,
3242 			 "Found new BMC (man_id: 0x%6.6x, prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n",
3243 			 bmc->id.manufacturer_id,
3244 			 bmc->id.product_id,
3245 			 bmc->id.device_id);
3246 	}
3247 
3248 	/*
3249 	 * create symlink from system interface device to bmc device
3250 	 * and back.
3251 	 */
3252 	rv = sysfs_create_link(&intf->si_dev->kobj, &bmc->pdev.dev.kobj, "bmc");
3253 	if (rv) {
3254 		dev_err(intf->si_dev, "Unable to create bmc symlink: %d\n", rv);
3255 		goto out_put_bmc;
3256 	}
3257 
3258 	if (intf_num == -1)
3259 		intf_num = intf->intf_num;
3260 	intf->my_dev_name = kasprintf(GFP_KERNEL, "ipmi%d", intf_num);
3261 	if (!intf->my_dev_name) {
3262 		rv = -ENOMEM;
3263 		dev_err(intf->si_dev, "Unable to allocate link from BMC: %d\n",
3264 			rv);
3265 		goto out_unlink1;
3266 	}
3267 
3268 	rv = sysfs_create_link(&bmc->pdev.dev.kobj, &intf->si_dev->kobj,
3269 			       intf->my_dev_name);
3270 	if (rv) {
3271 		dev_err(intf->si_dev, "Unable to create symlink to bmc: %d\n",
3272 			rv);
3273 		goto out_free_my_dev_name;
3274 	}
3275 
3276 	intf->bmc_registered = true;
3277 
3278 out:
3279 	mutex_unlock(&ipmidriver_mutex);
3280 	mutex_lock(&intf->bmc_reg_mutex);
3281 	intf->in_bmc_register = false;
3282 	return rv;
3283 
3284 
3285 out_free_my_dev_name:
3286 	kfree(intf->my_dev_name);
3287 	intf->my_dev_name = NULL;
3288 
3289 out_unlink1:
3290 	sysfs_remove_link(&intf->si_dev->kobj, "bmc");
3291 
3292 out_put_bmc:
3293 	mutex_lock(&bmc->dyn_mutex);
3294 	list_del(&intf->bmc_link);
3295 	mutex_unlock(&bmc->dyn_mutex);
3296 	intf->bmc = &intf->tmp_bmc;
3297 	kref_put(&bmc->usecount, cleanup_bmc_device);
3298 	goto out;
3299 
3300 out_list_del:
3301 	mutex_lock(&bmc->dyn_mutex);
3302 	list_del(&intf->bmc_link);
3303 	mutex_unlock(&bmc->dyn_mutex);
3304 	intf->bmc = &intf->tmp_bmc;
3305 	ida_free(&ipmi_bmc_ida, bmc->pdev.id);
3306 	put_device(&bmc->pdev.dev);
3307 	goto out;
3308 }
3309 
3310 static int
3311 send_guid_cmd(struct ipmi_smi *intf, int chan)
3312 {
3313 	struct kernel_ipmi_msg            msg;
3314 	struct ipmi_system_interface_addr si;
3315 
3316 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
3317 	si.channel = IPMI_BMC_CHANNEL;
3318 	si.lun = 0;
3319 
3320 	msg.netfn = IPMI_NETFN_APP_REQUEST;
3321 	msg.cmd = IPMI_GET_DEVICE_GUID_CMD;
3322 	msg.data = NULL;
3323 	msg.data_len = 0;
3324 	return i_ipmi_request(NULL,
3325 			      intf,
3326 			      (struct ipmi_addr *) &si,
3327 			      0,
3328 			      &msg,
3329 			      intf,
3330 			      NULL,
3331 			      NULL,
3332 			      0,
3333 			      intf->addrinfo[0].address,
3334 			      intf->addrinfo[0].lun,
3335 			      -1, 0);
3336 }
3337 
3338 static void guid_handler(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
3339 {
3340 	struct bmc_device *bmc = intf->bmc;
3341 
3342 	if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
3343 	    || (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE)
3344 	    || (msg->msg.cmd != IPMI_GET_DEVICE_GUID_CMD))
3345 		/* Not for me */
3346 		return;
3347 
3348 	if (msg->msg.data[0] != 0) {
3349 		/* Error from getting the GUID, the BMC doesn't have one. */
3350 		bmc->dyn_guid_set = 0;
3351 		goto out;
3352 	}
3353 
3354 	if (msg->msg.data_len < UUID_SIZE + 1) {
3355 		bmc->dyn_guid_set = 0;
3356 		dev_warn(intf->si_dev,
3357 			 "The GUID response from the BMC was too short, it was %d but should have been %d.  Assuming GUID is not available.\n",
3358 			 msg->msg.data_len, UUID_SIZE + 1);
3359 		goto out;
3360 	}
3361 
3362 	import_guid(&bmc->fetch_guid, msg->msg.data + 1);
3363 	/*
3364 	 * Make sure the guid data is available before setting
3365 	 * dyn_guid_set.
3366 	 */
3367 	smp_wmb();
3368 	bmc->dyn_guid_set = 1;
3369  out:
3370 	wake_up(&intf->waitq);
3371 }
3372 
3373 static void __get_guid(struct ipmi_smi *intf)
3374 {
3375 	int rv;
3376 	struct bmc_device *bmc = intf->bmc;
3377 
3378 	bmc->dyn_guid_set = 2;
3379 	intf->null_user_handler = guid_handler;
3380 	rv = send_guid_cmd(intf, 0);
3381 	if (rv)
3382 		/* Send failed, no GUID available. */
3383 		bmc->dyn_guid_set = 0;
3384 	else
3385 		wait_event(intf->waitq, bmc->dyn_guid_set != 2);
3386 
3387 	/* dyn_guid_set makes the guid data available. */
3388 	smp_rmb();
3389 
3390 	intf->null_user_handler = NULL;
3391 }
3392 
3393 static int
3394 send_channel_info_cmd(struct ipmi_smi *intf, int chan)
3395 {
3396 	struct kernel_ipmi_msg            msg;
3397 	unsigned char                     data[1];
3398 	struct ipmi_system_interface_addr si;
3399 
3400 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
3401 	si.channel = IPMI_BMC_CHANNEL;
3402 	si.lun = 0;
3403 
3404 	msg.netfn = IPMI_NETFN_APP_REQUEST;
3405 	msg.cmd = IPMI_GET_CHANNEL_INFO_CMD;
3406 	msg.data = data;
3407 	msg.data_len = 1;
3408 	data[0] = chan;
3409 	return i_ipmi_request(NULL,
3410 			      intf,
3411 			      (struct ipmi_addr *) &si,
3412 			      0,
3413 			      &msg,
3414 			      intf,
3415 			      NULL,
3416 			      NULL,
3417 			      0,
3418 			      intf->addrinfo[0].address,
3419 			      intf->addrinfo[0].lun,
3420 			      -1, 0);
3421 }
3422 
3423 static void
3424 channel_handler(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
3425 {
3426 	int rv = 0;
3427 	int ch;
3428 	unsigned int set = intf->curr_working_cset;
3429 	struct ipmi_channel *chans;
3430 
3431 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
3432 	    && (msg->msg.netfn == IPMI_NETFN_APP_RESPONSE)
3433 	    && (msg->msg.cmd == IPMI_GET_CHANNEL_INFO_CMD)) {
3434 		/* It's the one we want */
3435 		if (msg->msg.data[0] != 0) {
3436 			/* Got an error from the channel, just go on. */
3437 			if (msg->msg.data[0] == IPMI_INVALID_COMMAND_ERR) {
3438 				/*
3439 				 * If the MC does not support this
3440 				 * command, that is legal.  We just
3441 				 * assume it has one IPMB at channel
3442 				 * zero.
3443 				 */
3444 				intf->wchannels[set].c[0].medium
3445 					= IPMI_CHANNEL_MEDIUM_IPMB;
3446 				intf->wchannels[set].c[0].protocol
3447 					= IPMI_CHANNEL_PROTOCOL_IPMB;
3448 
3449 				intf->channel_list = intf->wchannels + set;
3450 				intf->channels_ready = true;
3451 				wake_up(&intf->waitq);
3452 				goto out;
3453 			}
3454 			goto next_channel;
3455 		}
3456 		if (msg->msg.data_len < 4) {
3457 			/* Message not big enough, just go on. */
3458 			goto next_channel;
3459 		}
3460 		ch = intf->curr_channel;
3461 		chans = intf->wchannels[set].c;
3462 		chans[ch].medium = msg->msg.data[2] & 0x7f;
3463 		chans[ch].protocol = msg->msg.data[3] & 0x1f;
3464 
3465  next_channel:
3466 		intf->curr_channel++;
3467 		if (intf->curr_channel >= IPMI_MAX_CHANNELS) {
3468 			intf->channel_list = intf->wchannels + set;
3469 			intf->channels_ready = true;
3470 			wake_up(&intf->waitq);
3471 		} else {
3472 			rv = send_channel_info_cmd(intf, intf->curr_channel);
3473 		}
3474 
3475 		if (rv) {
3476 			/* Got an error somehow, just give up. */
3477 			dev_warn(intf->si_dev,
3478 				 "Error sending channel information for channel %d: %d\n",
3479 				 intf->curr_channel, rv);
3480 
3481 			intf->channel_list = intf->wchannels + set;
3482 			intf->channels_ready = true;
3483 			wake_up(&intf->waitq);
3484 		}
3485 	}
3486  out:
3487 	return;
3488 }
3489 
3490 /*
3491  * Must be holding intf->bmc_reg_mutex to call this.
3492  */
3493 static int __scan_channels(struct ipmi_smi *intf,
3494 				struct ipmi_device_id *id,
3495 				bool rescan)
3496 {
3497 	int rv;
3498 
3499 	if (rescan) {
3500 		/* Clear channels_ready to force channels rescan. */
3501 		intf->channels_ready = false;
3502 	}
3503 
3504 	/* Skip channel scan if channels are already marked ready */
3505 	if (intf->channels_ready)
3506 		return 0;
3507 
3508 	if (ipmi_version_major(id) > 1
3509 			|| (ipmi_version_major(id) == 1
3510 			    && ipmi_version_minor(id) >= 5)) {
3511 		unsigned int set;
3512 
3513 		/*
3514 		 * Start scanning the channels to see what is
3515 		 * available.
3516 		 */
3517 		set = !intf->curr_working_cset;
3518 		intf->curr_working_cset = set;
3519 		memset(&intf->wchannels[set], 0,
3520 		       sizeof(struct ipmi_channel_set));
3521 
3522 		intf->null_user_handler = channel_handler;
3523 		intf->curr_channel = 0;
3524 		rv = send_channel_info_cmd(intf, 0);
3525 		if (rv) {
3526 			dev_warn(intf->si_dev,
3527 				 "Error sending channel information for channel 0, %d\n",
3528 				 rv);
3529 			intf->null_user_handler = NULL;
3530 			return -EIO;
3531 		}
3532 
3533 		/* Wait for the channel info to be read. */
3534 		wait_event(intf->waitq, intf->channels_ready);
3535 		intf->null_user_handler = NULL;
3536 	} else {
3537 		unsigned int set = intf->curr_working_cset;
3538 
3539 		/* Assume a single IPMB channel at zero. */
3540 		intf->wchannels[set].c[0].medium = IPMI_CHANNEL_MEDIUM_IPMB;
3541 		intf->wchannels[set].c[0].protocol = IPMI_CHANNEL_PROTOCOL_IPMB;
3542 		intf->channel_list = intf->wchannels + set;
3543 		intf->channels_ready = true;
3544 	}
3545 
3546 	return 0;
3547 }
3548 
3549 static void ipmi_poll(struct ipmi_smi *intf)
3550 {
3551 	if (intf->handlers->poll)
3552 		intf->handlers->poll(intf->send_info);
3553 	/* In case something came in */
3554 	handle_new_recv_msgs(intf);
3555 }
3556 
3557 void ipmi_poll_interface(struct ipmi_user *user)
3558 {
3559 	ipmi_poll(user->intf);
3560 }
3561 EXPORT_SYMBOL(ipmi_poll_interface);
3562 
3563 static ssize_t nr_users_show(struct device *dev,
3564 			     struct device_attribute *attr,
3565 			     char *buf)
3566 {
3567 	struct ipmi_smi *intf = container_of(attr,
3568 			 struct ipmi_smi, nr_users_devattr);
3569 
3570 	return sysfs_emit(buf, "%d\n", atomic_read(&intf->nr_users));
3571 }
3572 static DEVICE_ATTR_RO(nr_users);
3573 
3574 static ssize_t nr_msgs_show(struct device *dev,
3575 			    struct device_attribute *attr,
3576 			    char *buf)
3577 {
3578 	struct ipmi_smi *intf = container_of(attr,
3579 					     struct ipmi_smi, nr_msgs_devattr);
3580 	struct ipmi_user *user;
3581 	unsigned int count = 0;
3582 
3583 	mutex_lock(&intf->users_mutex);
3584 	list_for_each_entry(user, &intf->users, link)
3585 		count += atomic_read(&user->nr_msgs);
3586 	mutex_unlock(&intf->users_mutex);
3587 
3588 	return sysfs_emit(buf, "%u\n", count);
3589 }
3590 static DEVICE_ATTR_RO(nr_msgs);
3591 
3592 static ssize_t maintenance_mode_show(struct device *dev,
3593 				     struct device_attribute *attr,
3594 				     char *buf)
3595 {
3596 	struct ipmi_smi *intf = container_of(attr,
3597 					     struct ipmi_smi,
3598 					     maintenance_mode_devattr);
3599 
3600 	return sysfs_emit(buf, "%u %d\n", intf->maintenance_mode_state,
3601 			  intf->auto_maintenance_timeout);
3602 }
3603 static DEVICE_ATTR_RO(maintenance_mode);
3604 
3605 static void redo_bmc_reg(struct work_struct *work)
3606 {
3607 	struct ipmi_smi *intf = container_of(work, struct ipmi_smi,
3608 					     bmc_reg_work);
3609 
3610 	if (!intf->in_shutdown)
3611 		bmc_get_device_id(intf, NULL, NULL, NULL, NULL);
3612 
3613 	kref_put(&intf->refcount, intf_free);
3614 }
3615 
3616 int ipmi_add_smi(struct module         *owner,
3617 		 const struct ipmi_smi_handlers *handlers,
3618 		 void		       *send_info,
3619 		 struct device         *si_dev,
3620 		 unsigned char         slave_addr)
3621 {
3622 	int              i, j;
3623 	int              rv;
3624 	struct ipmi_smi *intf, *tintf;
3625 	struct list_head *link;
3626 	struct ipmi_device_id id;
3627 
3628 	/*
3629 	 * Make sure the driver is actually initialized, this handles
3630 	 * problems with initialization order.
3631 	 */
3632 	rv = ipmi_init_msghandler();
3633 	if (rv)
3634 		return rv;
3635 
3636 	intf = kzalloc_obj(*intf);
3637 	if (!intf)
3638 		return -ENOMEM;
3639 
3640 	intf->owner = owner;
3641 	intf->bmc = &intf->tmp_bmc;
3642 	INIT_LIST_HEAD(&intf->bmc->intfs);
3643 	mutex_init(&intf->bmc->dyn_mutex);
3644 	INIT_LIST_HEAD(&intf->bmc_link);
3645 	mutex_init(&intf->bmc_reg_mutex);
3646 	intf->intf_num = -1; /* Mark it invalid for now. */
3647 	kref_init(&intf->refcount);
3648 	INIT_WORK(&intf->bmc_reg_work, redo_bmc_reg);
3649 	intf->si_dev = si_dev;
3650 	for (j = 0; j < IPMI_MAX_CHANNELS; j++) {
3651 		intf->addrinfo[j].address = IPMI_BMC_SLAVE_ADDR;
3652 		intf->addrinfo[j].lun = 2;
3653 	}
3654 	if (slave_addr != 0)
3655 		intf->addrinfo[0].address = slave_addr;
3656 	INIT_LIST_HEAD(&intf->user_msgs);
3657 	mutex_init(&intf->user_msgs_mutex);
3658 	INIT_LIST_HEAD(&intf->users);
3659 	mutex_init(&intf->users_mutex);
3660 	atomic_set(&intf->nr_users, 0);
3661 	intf->handlers = handlers;
3662 	intf->send_info = send_info;
3663 	mutex_init(&intf->seq_lock);
3664 	for (j = 0; j < IPMI_IPMB_NUM_SEQ; j++) {
3665 		intf->seq_table[j].inuse = 0;
3666 		intf->seq_table[j].seqid = 0;
3667 	}
3668 	intf->curr_seq = 0;
3669 	spin_lock_init(&intf->waiting_rcv_msgs_lock);
3670 	INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
3671 	INIT_WORK(&intf->smi_work, smi_work);
3672 	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 0);
3673 	spin_lock_init(&intf->xmit_msgs_lock);
3674 	INIT_LIST_HEAD(&intf->xmit_msgs);
3675 	INIT_LIST_HEAD(&intf->hp_xmit_msgs);
3676 	mutex_init(&intf->events_mutex);
3677 	spin_lock_init(&intf->watch_lock);
3678 	atomic_set(&intf->event_waiters, 0);
3679 	intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
3680 	INIT_LIST_HEAD(&intf->waiting_events);
3681 	intf->waiting_events_count = 0;
3682 	mutex_init(&intf->cmd_rcvrs_mutex);
3683 	spin_lock_init(&intf->maintenance_mode_lock);
3684 	INIT_LIST_HEAD(&intf->cmd_rcvrs);
3685 	init_waitqueue_head(&intf->waitq);
3686 	for (i = 0; i < IPMI_NUM_STATS; i++)
3687 		atomic_set(&intf->stats[i], 0);
3688 
3689 	/*
3690 	 * Grab the watchers mutex so we can deliver the new interface
3691 	 * without races.
3692 	 */
3693 	mutex_lock(&smi_watchers_mutex);
3694 	mutex_lock(&ipmi_interfaces_mutex);
3695 	/* Look for a hole in the numbers. */
3696 	i = 0;
3697 	link = &ipmi_interfaces;
3698 	list_for_each_entry(tintf, &ipmi_interfaces, link) {
3699 		if (tintf->intf_num != i) {
3700 			link = &tintf->link;
3701 			break;
3702 		}
3703 		i++;
3704 	}
3705 	/* Add the new interface in numeric order. */
3706 	if (i == 0)
3707 		list_add(&intf->link, &ipmi_interfaces);
3708 	else
3709 		list_add_tail(&intf->link, link);
3710 
3711 	rv = handlers->start_processing(send_info, intf);
3712 	if (rv)
3713 		goto out_err;
3714 
3715 	rv = __bmc_get_device_id(intf, NULL, &id, NULL, NULL, i);
3716 	if (rv) {
3717 		dev_err(si_dev, "Unable to get the device id: %d\n", rv);
3718 		goto out_err_started;
3719 	}
3720 
3721 	mutex_lock(&intf->bmc_reg_mutex);
3722 	rv = __scan_channels(intf, &id, false);
3723 	mutex_unlock(&intf->bmc_reg_mutex);
3724 	if (rv)
3725 		goto out_err_bmc_reg;
3726 
3727 	intf->nr_users_devattr = dev_attr_nr_users;
3728 	sysfs_attr_init(&intf->nr_users_devattr.attr);
3729 	rv = device_create_file(intf->si_dev, &intf->nr_users_devattr);
3730 	if (rv)
3731 		goto out_err_bmc_reg;
3732 
3733 	intf->nr_msgs_devattr = dev_attr_nr_msgs;
3734 	sysfs_attr_init(&intf->nr_msgs_devattr.attr);
3735 	rv = device_create_file(intf->si_dev, &intf->nr_msgs_devattr);
3736 	if (rv) {
3737 		device_remove_file(intf->si_dev, &intf->nr_users_devattr);
3738 		goto out_err_bmc_reg;
3739 	}
3740 
3741 	intf->maintenance_mode_devattr = dev_attr_maintenance_mode;
3742 	sysfs_attr_init(&intf->maintenance_mode_devattr.attr);
3743 	rv = device_create_file(intf->si_dev, &intf->maintenance_mode_devattr);
3744 	if (rv) {
3745 		device_remove_file(intf->si_dev, &intf->nr_msgs_devattr);
3746 		device_remove_file(intf->si_dev, &intf->nr_users_devattr);
3747 		goto out_err_bmc_reg;
3748 	}
3749 
3750 	intf->intf_num = i;
3751 	mutex_unlock(&ipmi_interfaces_mutex);
3752 
3753 	/* After this point the interface is legal to use. */
3754 	call_smi_watchers(i, intf->si_dev);
3755 
3756 	mutex_unlock(&smi_watchers_mutex);
3757 
3758 	return 0;
3759 
3760  out_err_bmc_reg:
3761 	ipmi_bmc_unregister(intf);
3762  out_err_started:
3763 	intf->in_shutdown = true;
3764 	if (intf->handlers->shutdown)
3765 		intf->handlers->shutdown(intf->send_info);
3766  out_err:
3767 	list_del(&intf->link);
3768 	mutex_unlock(&ipmi_interfaces_mutex);
3769 	mutex_unlock(&smi_watchers_mutex);
3770 	cancel_work_sync(&intf->smi_work);
3771 	kref_put(&intf->refcount, intf_free);
3772 
3773 	return rv;
3774 }
3775 EXPORT_SYMBOL(ipmi_add_smi);
3776 
3777 static void deliver_smi_err_response(struct ipmi_smi *intf,
3778 				     struct ipmi_smi_msg *msg,
3779 				     unsigned char err)
3780 {
3781 	int rv;
3782 	msg->rsp[0] = msg->data[0] | 4;
3783 	msg->rsp[1] = msg->data[1];
3784 	msg->rsp[2] = err;
3785 	msg->rsp_size = 3;
3786 
3787 	/* This will never requeue, but it may ask us to free the message. */
3788 	rv = handle_one_recv_msg(intf, msg);
3789 	if (rv == 0)
3790 		ipmi_free_smi_msg(msg);
3791 }
3792 
3793 static void cleanup_smi_msgs(struct ipmi_smi *intf)
3794 {
3795 	int              i;
3796 	struct seq_table *ent;
3797 	struct ipmi_smi_msg *msg;
3798 	struct list_head *entry;
3799 	LIST_HEAD(tmplist);
3800 
3801 	/* Clear out our transmit queues and hold the messages. */
3802 	list_splice_tail(&intf->hp_xmit_msgs, &tmplist);
3803 	list_splice_tail(&intf->xmit_msgs, &tmplist);
3804 
3805 	/* Current message first, to preserve order */
3806 	while (intf->curr_msg && !list_empty(&intf->waiting_rcv_msgs)) {
3807 		/* Wait for the message to clear out. */
3808 		schedule_timeout(1);
3809 	}
3810 
3811 	/* No need for locks, the interface is down. */
3812 
3813 	/*
3814 	 * Return errors for all pending messages in queue and in the
3815 	 * tables waiting for remote responses.
3816 	 */
3817 	while (!list_empty(&tmplist)) {
3818 		entry = tmplist.next;
3819 		list_del(entry);
3820 		msg = list_entry(entry, struct ipmi_smi_msg, link);
3821 		deliver_smi_err_response(intf, msg, IPMI_ERR_UNSPECIFIED);
3822 	}
3823 
3824 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
3825 		ent = &intf->seq_table[i];
3826 		if (!ent->inuse)
3827 			continue;
3828 		deliver_err_response(intf, ent->recv_msg, IPMI_ERR_UNSPECIFIED);
3829 	}
3830 }
3831 
3832 void ipmi_unregister_smi(struct ipmi_smi *intf)
3833 {
3834 	struct ipmi_smi_watcher *w;
3835 	int intf_num;
3836 
3837 	if (!intf)
3838 		return;
3839 
3840 	intf_num = intf->intf_num;
3841 	mutex_lock(&ipmi_interfaces_mutex);
3842 	cancel_work_sync(&intf->smi_work);
3843 	/* smi_work() can no longer be in progress after this. */
3844 
3845 	intf->intf_num = -1;
3846 	intf->in_shutdown = true;
3847 	list_del(&intf->link);
3848 	mutex_unlock(&ipmi_interfaces_mutex);
3849 
3850 	/*
3851 	 * At this point no users can be added to the interface and no
3852 	 * new messages can be sent.
3853 	 */
3854 
3855 	if (intf->handlers->shutdown)
3856 		intf->handlers->shutdown(intf->send_info);
3857 
3858 	device_remove_file(intf->si_dev, &intf->maintenance_mode_devattr);
3859 	device_remove_file(intf->si_dev, &intf->nr_msgs_devattr);
3860 	device_remove_file(intf->si_dev, &intf->nr_users_devattr);
3861 
3862 	/*
3863 	 * Call all the watcher interfaces to tell them that
3864 	 * an interface is going away.
3865 	 */
3866 	mutex_lock(&smi_watchers_mutex);
3867 	list_for_each_entry(w, &smi_watchers, link)
3868 		w->smi_gone(intf_num);
3869 	mutex_unlock(&smi_watchers_mutex);
3870 
3871 	mutex_lock(&intf->users_mutex);
3872 	while (!list_empty(&intf->users)) {
3873 		struct ipmi_user *user = list_first_entry(&intf->users,
3874 						    struct ipmi_user, link);
3875 
3876 		_ipmi_destroy_user(user);
3877 	}
3878 	mutex_unlock(&intf->users_mutex);
3879 
3880 	cleanup_smi_msgs(intf);
3881 
3882 	ipmi_bmc_unregister(intf);
3883 
3884 	kref_put(&intf->refcount, intf_free);
3885 }
3886 EXPORT_SYMBOL(ipmi_unregister_smi);
3887 
3888 static int handle_ipmb_get_msg_rsp(struct ipmi_smi *intf,
3889 				   struct ipmi_smi_msg *msg)
3890 {
3891 	struct ipmi_ipmb_addr ipmb_addr;
3892 	struct ipmi_recv_msg  *recv_msg;
3893 
3894 	/*
3895 	 * This is 11, not 10, because the response must contain a
3896 	 * completion code.
3897 	 */
3898 	if (msg->rsp_size < 11) {
3899 		/* Message not big enough, just ignore it. */
3900 		ipmi_inc_stat(intf, invalid_ipmb_responses);
3901 		return 0;
3902 	}
3903 
3904 	if (msg->rsp[2] != 0) {
3905 		/* An error getting the response, just ignore it. */
3906 		return 0;
3907 	}
3908 
3909 	ipmb_addr.addr_type = IPMI_IPMB_ADDR_TYPE;
3910 	ipmb_addr.slave_addr = msg->rsp[6];
3911 	ipmb_addr.channel = msg->rsp[3] & 0x0f;
3912 	ipmb_addr.lun = msg->rsp[7] & 3;
3913 
3914 	/*
3915 	 * It's a response from a remote entity.  Look up the sequence
3916 	 * number and handle the response.
3917 	 */
3918 	if (intf_find_seq(intf,
3919 			  msg->rsp[7] >> 2,
3920 			  msg->rsp[3] & 0x0f,
3921 			  msg->rsp[8],
3922 			  (msg->rsp[4] >> 2) & (~1),
3923 			  (struct ipmi_addr *) &ipmb_addr,
3924 			  &recv_msg)) {
3925 		/*
3926 		 * We were unable to find the sequence number,
3927 		 * so just nuke the message.
3928 		 */
3929 		ipmi_inc_stat(intf, unhandled_ipmb_responses);
3930 		return 0;
3931 	}
3932 
3933 	memcpy(recv_msg->msg_data, &msg->rsp[9], msg->rsp_size - 9);
3934 	/*
3935 	 * The other fields matched, so no need to set them, except
3936 	 * for netfn, which needs to be the response that was
3937 	 * returned, not the request value.
3938 	 */
3939 	recv_msg->msg.netfn = msg->rsp[4] >> 2;
3940 	recv_msg->msg.data = recv_msg->msg_data;
3941 	recv_msg->msg.data_len = msg->rsp_size - 10;
3942 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
3943 	if (deliver_response(intf, recv_msg))
3944 		ipmi_inc_stat(intf, unhandled_ipmb_responses);
3945 	else
3946 		ipmi_inc_stat(intf, handled_ipmb_responses);
3947 
3948 	return 0;
3949 }
3950 
3951 static int handle_ipmb_get_msg_cmd(struct ipmi_smi *intf,
3952 				   struct ipmi_smi_msg *msg)
3953 {
3954 	struct cmd_rcvr          *rcvr;
3955 	int                      rv = 0;
3956 	unsigned char            netfn;
3957 	unsigned char            cmd;
3958 	unsigned char            chan;
3959 	struct ipmi_user         *user = NULL;
3960 	struct ipmi_ipmb_addr    *ipmb_addr;
3961 	struct ipmi_recv_msg     *recv_msg = NULL;
3962 
3963 	if (msg->rsp_size < 10) {
3964 		/* Message not big enough, just ignore it. */
3965 		ipmi_inc_stat(intf, invalid_commands);
3966 		return 0;
3967 	}
3968 
3969 	if (msg->rsp[2] != 0) {
3970 		/* An error getting the response, just ignore it. */
3971 		return 0;
3972 	}
3973 
3974 	netfn = msg->rsp[4] >> 2;
3975 	cmd = msg->rsp[8];
3976 	chan = msg->rsp[3] & 0xf;
3977 
3978 	rcu_read_lock();
3979 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
3980 	if (rcvr) {
3981 		user = rcvr->user;
3982 		recv_msg = ipmi_alloc_recv_msg(user);
3983 	}
3984 	rcu_read_unlock();
3985 
3986 	if (user == NULL) {
3987 		/* We didn't find a user, deliver an error response. */
3988 		ipmi_inc_stat(intf, unhandled_commands);
3989 
3990 		msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
3991 		msg->data[1] = IPMI_SEND_MSG_CMD;
3992 		msg->data[2] = msg->rsp[3];
3993 		msg->data[3] = msg->rsp[6];
3994 		msg->data[4] = ((netfn + 1) << 2) | (msg->rsp[7] & 0x3);
3995 		msg->data[5] = ipmb_checksum(&msg->data[3], 2);
3996 		msg->data[6] = intf->addrinfo[msg->rsp[3] & 0xf].address;
3997 		/* rqseq/lun */
3998 		msg->data[7] = (msg->rsp[7] & 0xfc) | (msg->rsp[4] & 0x3);
3999 		msg->data[8] = msg->rsp[8]; /* cmd */
4000 		msg->data[9] = IPMI_INVALID_CMD_COMPLETION_CODE;
4001 		msg->data[10] = ipmb_checksum(&msg->data[6], 4);
4002 		msg->data_size = 11;
4003 
4004 		dev_dbg(intf->si_dev, "Invalid command: %*ph\n",
4005 			msg->data_size, msg->data);
4006 
4007 		if (smi_send(intf, intf->handlers, msg, 0) == IPMI_CC_NO_ERROR)
4008 			/*
4009 			 * We used the message, so return the value that
4010 			 * causes it to not be freed or queued.
4011 			 */
4012 			rv = -1;
4013 	} else if (!IS_ERR(recv_msg)) {
4014 		/* Extract the source address from the data. */
4015 		ipmb_addr = (struct ipmi_ipmb_addr *) &recv_msg->addr;
4016 		ipmb_addr->addr_type = IPMI_IPMB_ADDR_TYPE;
4017 		ipmb_addr->slave_addr = msg->rsp[6];
4018 		ipmb_addr->lun = msg->rsp[7] & 3;
4019 		ipmb_addr->channel = msg->rsp[3] & 0xf;
4020 
4021 		/*
4022 		 * Extract the rest of the message information
4023 		 * from the IPMB header.
4024 		 */
4025 		recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
4026 		recv_msg->msgid = msg->rsp[7] >> 2;
4027 		recv_msg->msg.netfn = msg->rsp[4] >> 2;
4028 		recv_msg->msg.cmd = msg->rsp[8];
4029 		recv_msg->msg.data = recv_msg->msg_data;
4030 
4031 		/*
4032 		 * We chop off 10, not 9 bytes because the checksum
4033 		 * at the end also needs to be removed.
4034 		 */
4035 		recv_msg->msg.data_len = msg->rsp_size - 10;
4036 		memcpy(recv_msg->msg_data, &msg->rsp[9],
4037 		       msg->rsp_size - 10);
4038 		if (deliver_response(intf, recv_msg))
4039 			ipmi_inc_stat(intf, unhandled_commands);
4040 		else
4041 			ipmi_inc_stat(intf, handled_commands);
4042 	} else {
4043 		/*
4044 		 * We couldn't allocate memory for the message, so
4045 		 * requeue it for handling later.
4046 		 */
4047 		rv = 1;
4048 	}
4049 
4050 	return rv;
4051 }
4052 
4053 static int handle_ipmb_direct_rcv_cmd(struct ipmi_smi *intf,
4054 				      struct ipmi_smi_msg *msg)
4055 {
4056 	struct cmd_rcvr          *rcvr;
4057 	int                      rv = 0;
4058 	struct ipmi_user         *user = NULL;
4059 	struct ipmi_ipmb_direct_addr *daddr;
4060 	struct ipmi_recv_msg     *recv_msg = NULL;
4061 	unsigned char netfn = msg->rsp[0] >> 2;
4062 	unsigned char cmd = msg->rsp[3];
4063 
4064 	rcu_read_lock();
4065 	/* We always use channel 0 for direct messages. */
4066 	rcvr = find_cmd_rcvr(intf, netfn, cmd, 0);
4067 	if (rcvr) {
4068 		user = rcvr->user;
4069 		recv_msg = ipmi_alloc_recv_msg(user);
4070 	}
4071 	rcu_read_unlock();
4072 
4073 	if (user == NULL) {
4074 		/* We didn't find a user, deliver an error response. */
4075 		ipmi_inc_stat(intf, unhandled_commands);
4076 
4077 		msg->data[0] = (netfn + 1) << 2;
4078 		msg->data[0] |= msg->rsp[2] & 0x3; /* rqLUN */
4079 		msg->data[1] = msg->rsp[1]; /* Addr */
4080 		msg->data[2] = msg->rsp[2] & ~0x3; /* rqSeq */
4081 		msg->data[2] |= msg->rsp[0] & 0x3; /* rsLUN */
4082 		msg->data[3] = cmd;
4083 		msg->data[4] = IPMI_INVALID_CMD_COMPLETION_CODE;
4084 		msg->data_size = 5;
4085 
4086 		if (smi_send(intf, intf->handlers, msg, 0) == IPMI_CC_NO_ERROR)
4087 			/*
4088 			 * We used the message, so return the value that
4089 			 * causes it to not be freed or queued.
4090 			 */
4091 			rv = -1;
4092 	} else if (!IS_ERR(recv_msg)) {
4093 		/* Extract the source address from the data. */
4094 		daddr = (struct ipmi_ipmb_direct_addr *)&recv_msg->addr;
4095 		daddr->addr_type = IPMI_IPMB_DIRECT_ADDR_TYPE;
4096 		daddr->channel = 0;
4097 		daddr->slave_addr = msg->rsp[1];
4098 		daddr->rs_lun = msg->rsp[0] & 3;
4099 		daddr->rq_lun = msg->rsp[2] & 3;
4100 
4101 		/*
4102 		 * Extract the rest of the message information
4103 		 * from the IPMB header.
4104 		 */
4105 		recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
4106 		recv_msg->msgid = (msg->rsp[2] >> 2);
4107 		recv_msg->msg.netfn = msg->rsp[0] >> 2;
4108 		recv_msg->msg.cmd = msg->rsp[3];
4109 		recv_msg->msg.data = recv_msg->msg_data;
4110 
4111 		recv_msg->msg.data_len = msg->rsp_size - 4;
4112 		memcpy(recv_msg->msg_data, msg->rsp + 4,
4113 		       msg->rsp_size - 4);
4114 		if (deliver_response(intf, recv_msg))
4115 			ipmi_inc_stat(intf, unhandled_commands);
4116 		else
4117 			ipmi_inc_stat(intf, handled_commands);
4118 	} else {
4119 		/*
4120 		 * We couldn't allocate memory for the message, so
4121 		 * requeue it for handling later.
4122 		 */
4123 		rv = 1;
4124 	}
4125 
4126 	return rv;
4127 }
4128 
4129 static int handle_ipmb_direct_rcv_rsp(struct ipmi_smi *intf,
4130 				      struct ipmi_smi_msg *msg)
4131 {
4132 	struct ipmi_recv_msg *recv_msg;
4133 	struct ipmi_ipmb_direct_addr *daddr;
4134 
4135 	recv_msg = msg->recv_msg;
4136 	if (recv_msg == NULL) {
4137 		dev_warn(intf->si_dev,
4138 			 "IPMI direct message received with no owner. This could be because of a malformed message, or because of a hardware error.  Contact your hardware vendor for assistance.\n");
4139 		return 0;
4140 	}
4141 
4142 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
4143 	recv_msg->msgid = msg->msgid;
4144 	daddr = (struct ipmi_ipmb_direct_addr *) &recv_msg->addr;
4145 	daddr->addr_type = IPMI_IPMB_DIRECT_ADDR_TYPE;
4146 	daddr->channel = 0;
4147 	daddr->slave_addr = msg->rsp[1];
4148 	daddr->rq_lun = msg->rsp[0] & 3;
4149 	daddr->rs_lun = msg->rsp[2] & 3;
4150 	recv_msg->msg.netfn = msg->rsp[0] >> 2;
4151 	recv_msg->msg.cmd = msg->rsp[3];
4152 	memcpy(recv_msg->msg_data, &msg->rsp[4], msg->rsp_size - 4);
4153 	recv_msg->msg.data = recv_msg->msg_data;
4154 	recv_msg->msg.data_len = msg->rsp_size - 4;
4155 	deliver_local_response(intf, recv_msg);
4156 
4157 	return 0;
4158 }
4159 
4160 static int handle_lan_get_msg_rsp(struct ipmi_smi *intf,
4161 				  struct ipmi_smi_msg *msg)
4162 {
4163 	struct ipmi_lan_addr  lan_addr;
4164 	struct ipmi_recv_msg  *recv_msg;
4165 
4166 
4167 	/*
4168 	 * This is 13, not 12, because the response must contain a
4169 	 * completion code.
4170 	 */
4171 	if (msg->rsp_size < 13) {
4172 		/* Message not big enough, just ignore it. */
4173 		ipmi_inc_stat(intf, invalid_lan_responses);
4174 		return 0;
4175 	}
4176 
4177 	if (msg->rsp[2] != 0) {
4178 		/* An error getting the response, just ignore it. */
4179 		return 0;
4180 	}
4181 
4182 	lan_addr.addr_type = IPMI_LAN_ADDR_TYPE;
4183 	lan_addr.session_handle = msg->rsp[4];
4184 	lan_addr.remote_SWID = msg->rsp[8];
4185 	lan_addr.local_SWID = msg->rsp[5];
4186 	lan_addr.channel = msg->rsp[3] & 0x0f;
4187 	lan_addr.privilege = msg->rsp[3] >> 4;
4188 	lan_addr.lun = msg->rsp[9] & 3;
4189 
4190 	/*
4191 	 * It's a response from a remote entity.  Look up the sequence
4192 	 * number and handle the response.
4193 	 */
4194 	if (intf_find_seq(intf,
4195 			  msg->rsp[9] >> 2,
4196 			  msg->rsp[3] & 0x0f,
4197 			  msg->rsp[10],
4198 			  (msg->rsp[6] >> 2) & (~1),
4199 			  (struct ipmi_addr *) &lan_addr,
4200 			  &recv_msg)) {
4201 		/*
4202 		 * We were unable to find the sequence number,
4203 		 * so just nuke the message.
4204 		 */
4205 		ipmi_inc_stat(intf, unhandled_lan_responses);
4206 		return 0;
4207 	}
4208 
4209 	memcpy(recv_msg->msg_data, &msg->rsp[11], msg->rsp_size - 11);
4210 	/*
4211 	 * The other fields matched, so no need to set them, except
4212 	 * for netfn, which needs to be the response that was
4213 	 * returned, not the request value.
4214 	 */
4215 	recv_msg->msg.netfn = msg->rsp[6] >> 2;
4216 	recv_msg->msg.data = recv_msg->msg_data;
4217 	recv_msg->msg.data_len = msg->rsp_size - 12;
4218 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
4219 	if (deliver_response(intf, recv_msg))
4220 		ipmi_inc_stat(intf, unhandled_lan_responses);
4221 	else
4222 		ipmi_inc_stat(intf, handled_lan_responses);
4223 
4224 	return 0;
4225 }
4226 
4227 static int handle_lan_get_msg_cmd(struct ipmi_smi *intf,
4228 				  struct ipmi_smi_msg *msg)
4229 {
4230 	struct cmd_rcvr          *rcvr;
4231 	int                      rv = 0; /* Free by default */
4232 	unsigned char            netfn;
4233 	unsigned char            cmd;
4234 	unsigned char            chan;
4235 	struct ipmi_user         *user = NULL;
4236 	struct ipmi_lan_addr     *lan_addr;
4237 	struct ipmi_recv_msg     *recv_msg = NULL;
4238 
4239 	if (msg->rsp_size < 12) {
4240 		/* Message not big enough, just ignore it. */
4241 		ipmi_inc_stat(intf, invalid_commands);
4242 		return 0;
4243 	}
4244 
4245 	if (msg->rsp[2] != 0) {
4246 		/* An error getting the response, just ignore it. */
4247 		return 0;
4248 	}
4249 
4250 	netfn = msg->rsp[6] >> 2;
4251 	cmd = msg->rsp[10];
4252 	chan = msg->rsp[3] & 0xf;
4253 
4254 	rcu_read_lock();
4255 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
4256 	if (rcvr) {
4257 		user = rcvr->user;
4258 		recv_msg = ipmi_alloc_recv_msg(user);
4259 	}
4260 	rcu_read_unlock();
4261 
4262 	if (user == NULL) {
4263 		/* We didn't find a user, just give up and return an error. */
4264 		ipmi_inc_stat(intf, unhandled_commands);
4265 
4266 		msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
4267 		msg->data[1] = IPMI_SEND_MSG_CMD;
4268 		msg->data[2] = chan;
4269 		msg->data[3] = msg->rsp[4]; /* handle */
4270 		msg->data[4] = msg->rsp[8]; /* rsSWID */
4271 		msg->data[5] = ((netfn + 1) << 2) | (msg->rsp[9] & 0x3);
4272 		msg->data[6] = ipmb_checksum(&msg->data[3], 3);
4273 		msg->data[7] = msg->rsp[5]; /* rqSWID */
4274 		/* rqseq/lun */
4275 		msg->data[8] = (msg->rsp[9] & 0xfc) | (msg->rsp[6] & 0x3);
4276 		msg->data[9] = cmd;
4277 		msg->data[10] = IPMI_INVALID_CMD_COMPLETION_CODE;
4278 		msg->data[11] = ipmb_checksum(&msg->data[7], 4);
4279 		msg->data_size = 12;
4280 
4281 		dev_dbg(intf->si_dev, "Invalid command: %*ph\n",
4282 			msg->data_size, msg->data);
4283 
4284 		if (smi_send(intf, intf->handlers, msg, 0) == IPMI_CC_NO_ERROR)
4285 			/*
4286 			 * We used the message, so return the value that
4287 			 * causes it to not be freed or queued.
4288 			 */
4289 			rv = -1;
4290 	} else if (!IS_ERR(recv_msg)) {
4291 		/* Extract the source address from the data. */
4292 		lan_addr = (struct ipmi_lan_addr *) &recv_msg->addr;
4293 		lan_addr->addr_type = IPMI_LAN_ADDR_TYPE;
4294 		lan_addr->session_handle = msg->rsp[4];
4295 		lan_addr->remote_SWID = msg->rsp[8];
4296 		lan_addr->local_SWID = msg->rsp[5];
4297 		lan_addr->lun = msg->rsp[9] & 3;
4298 		lan_addr->channel = msg->rsp[3] & 0xf;
4299 		lan_addr->privilege = msg->rsp[3] >> 4;
4300 
4301 		/*
4302 		 * Extract the rest of the message information
4303 		 * from the IPMB header.
4304 		 */
4305 		recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
4306 		recv_msg->msgid = msg->rsp[9] >> 2;
4307 		recv_msg->msg.netfn = msg->rsp[6] >> 2;
4308 		recv_msg->msg.cmd = msg->rsp[10];
4309 		recv_msg->msg.data = recv_msg->msg_data;
4310 
4311 		/*
4312 		 * We chop off 12, not 11 bytes because the checksum
4313 		 * at the end also needs to be removed.
4314 		 */
4315 		recv_msg->msg.data_len = msg->rsp_size - 12;
4316 		memcpy(recv_msg->msg_data, &msg->rsp[11],
4317 		       msg->rsp_size - 12);
4318 		if (deliver_response(intf, recv_msg))
4319 			ipmi_inc_stat(intf, unhandled_commands);
4320 		else
4321 			ipmi_inc_stat(intf, handled_commands);
4322 	} else {
4323 		/*
4324 		 * We couldn't allocate memory for the message, so
4325 		 * requeue it for handling later.
4326 		 */
4327 		rv = 1;
4328 	}
4329 
4330 	return rv;
4331 }
4332 
4333 /*
4334  * This routine will handle "Get Message" command responses with
4335  * channels that use an OEM Medium. The message format belongs to
4336  * the OEM.  See IPMI 2.0 specification, Chapter 6 and
4337  * Chapter 22, sections 22.6 and 22.24 for more details.
4338  */
4339 static int handle_oem_get_msg_cmd(struct ipmi_smi *intf,
4340 				  struct ipmi_smi_msg *msg)
4341 {
4342 	struct cmd_rcvr       *rcvr;
4343 	int                   rv = 0;
4344 	unsigned char         netfn;
4345 	unsigned char         cmd;
4346 	unsigned char         chan;
4347 	struct ipmi_user *user = NULL;
4348 	struct ipmi_system_interface_addr *smi_addr;
4349 	struct ipmi_recv_msg  *recv_msg = NULL;
4350 
4351 	/*
4352 	 * We expect the OEM SW to perform error checking
4353 	 * so we just do some basic sanity checks
4354 	 */
4355 	if (msg->rsp_size < 4) {
4356 		/* Message not big enough, just ignore it. */
4357 		ipmi_inc_stat(intf, invalid_commands);
4358 		return 0;
4359 	}
4360 
4361 	if (msg->rsp[2] != 0) {
4362 		/* An error getting the response, just ignore it. */
4363 		return 0;
4364 	}
4365 
4366 	/*
4367 	 * This is an OEM Message so the OEM needs to know how
4368 	 * handle the message. We do no interpretation.
4369 	 */
4370 	netfn = msg->rsp[0] >> 2;
4371 	cmd = msg->rsp[1];
4372 	chan = msg->rsp[3] & 0xf;
4373 
4374 	rcu_read_lock();
4375 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
4376 	if (rcvr) {
4377 		user = rcvr->user;
4378 		recv_msg = ipmi_alloc_recv_msg(user);
4379 	}
4380 	rcu_read_unlock();
4381 
4382 	if (user == NULL) {
4383 		/* We didn't find a user, just give up. */
4384 		ipmi_inc_stat(intf, unhandled_commands);
4385 
4386 		/*
4387 		 * Don't do anything with these messages, just allow
4388 		 * them to be freed.
4389 		 */
4390 
4391 		rv = 0;
4392 	} else if (!IS_ERR(recv_msg)) {
4393 		/*
4394 		 * OEM Messages are expected to be delivered via
4395 		 * the system interface to SMS software.  We might
4396 		 * need to visit this again depending on OEM
4397 		 * requirements
4398 		 */
4399 		smi_addr = ((struct ipmi_system_interface_addr *)
4400 			    &recv_msg->addr);
4401 		smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4402 		smi_addr->channel = IPMI_BMC_CHANNEL;
4403 		smi_addr->lun = msg->rsp[0] & 3;
4404 
4405 		recv_msg->user_msg_data = NULL;
4406 		recv_msg->recv_type = IPMI_OEM_RECV_TYPE;
4407 		recv_msg->msg.netfn = msg->rsp[0] >> 2;
4408 		recv_msg->msg.cmd = msg->rsp[1];
4409 		recv_msg->msg.data = recv_msg->msg_data;
4410 
4411 		/*
4412 		 * The message starts at byte 4 which follows the
4413 		 * Channel Byte in the "GET MESSAGE" command
4414 		 */
4415 		recv_msg->msg.data_len = msg->rsp_size - 4;
4416 		memcpy(recv_msg->msg_data, &msg->rsp[4],
4417 		       msg->rsp_size - 4);
4418 		if (deliver_response(intf, recv_msg))
4419 			ipmi_inc_stat(intf, unhandled_commands);
4420 		else
4421 			ipmi_inc_stat(intf, handled_commands);
4422 	} else {
4423 		/*
4424 		 * We couldn't allocate memory for the message, so
4425 		 * requeue it for handling later.
4426 		 */
4427 		rv = 1;
4428 	}
4429 
4430 	return rv;
4431 }
4432 
4433 static void copy_event_into_recv_msg(struct ipmi_recv_msg *recv_msg,
4434 				     struct ipmi_smi_msg  *msg)
4435 {
4436 	struct ipmi_system_interface_addr *smi_addr;
4437 
4438 	recv_msg->msgid = 0;
4439 	smi_addr = (struct ipmi_system_interface_addr *) &recv_msg->addr;
4440 	smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4441 	smi_addr->channel = IPMI_BMC_CHANNEL;
4442 	smi_addr->lun = msg->rsp[0] & 3;
4443 	recv_msg->recv_type = IPMI_ASYNC_EVENT_RECV_TYPE;
4444 	recv_msg->msg.netfn = msg->rsp[0] >> 2;
4445 	recv_msg->msg.cmd = msg->rsp[1];
4446 	memcpy(recv_msg->msg_data, &msg->rsp[3], msg->rsp_size - 3);
4447 	recv_msg->msg.data = recv_msg->msg_data;
4448 	recv_msg->msg.data_len = msg->rsp_size - 3;
4449 }
4450 
4451 static int handle_read_event_rsp(struct ipmi_smi *intf,
4452 				 struct ipmi_smi_msg *msg)
4453 {
4454 	struct ipmi_recv_msg *recv_msg, *recv_msg2;
4455 	LIST_HEAD(msgs);
4456 	struct ipmi_user     *user;
4457 	int rv = 0, deliver_count = 0;
4458 
4459 	if (msg->rsp_size < 19) {
4460 		/* Message is too small to be an IPMB event. */
4461 		ipmi_inc_stat(intf, invalid_events);
4462 		return 0;
4463 	}
4464 
4465 	if (msg->rsp[2] != 0) {
4466 		/* An error getting the event, just ignore it. */
4467 		return 0;
4468 	}
4469 
4470 	mutex_lock(&intf->events_mutex);
4471 
4472 	ipmi_inc_stat(intf, events);
4473 
4474 	/*
4475 	 * Allocate and fill in one message for every user that is
4476 	 * getting events.
4477 	 */
4478 	mutex_lock(&intf->users_mutex);
4479 	list_for_each_entry(user, &intf->users, link) {
4480 		if (!user->gets_events)
4481 			continue;
4482 
4483 		recv_msg = ipmi_alloc_recv_msg(user);
4484 		if (IS_ERR(recv_msg)) {
4485 			mutex_unlock(&intf->users_mutex);
4486 			list_for_each_entry_safe(recv_msg, recv_msg2, &msgs,
4487 						 link) {
4488 				list_del(&recv_msg->link);
4489 				ipmi_free_recv_msg(recv_msg);
4490 			}
4491 			/*
4492 			 * We couldn't allocate memory for the
4493 			 * message, so requeue it for handling
4494 			 * later.
4495 			 */
4496 			rv = 1;
4497 			goto out;
4498 		}
4499 
4500 		deliver_count++;
4501 
4502 		copy_event_into_recv_msg(recv_msg, msg);
4503 		list_add_tail(&recv_msg->link, &msgs);
4504 	}
4505 	mutex_unlock(&intf->users_mutex);
4506 
4507 	if (deliver_count) {
4508 		/* Now deliver all the messages. */
4509 		list_for_each_entry_safe(recv_msg, recv_msg2, &msgs, link) {
4510 			list_del(&recv_msg->link);
4511 			deliver_local_response(intf, recv_msg);
4512 		}
4513 	} else if (intf->waiting_events_count < MAX_EVENTS_IN_QUEUE) {
4514 		/*
4515 		 * No one to receive the message, put it in queue if there's
4516 		 * not already too many things in the queue.
4517 		 */
4518 		recv_msg = ipmi_alloc_recv_msg(NULL);
4519 		if (IS_ERR(recv_msg)) {
4520 			/*
4521 			 * We couldn't allocate memory for the
4522 			 * message, so requeue it for handling
4523 			 * later.
4524 			 */
4525 			rv = 1;
4526 			goto out;
4527 		}
4528 
4529 		copy_event_into_recv_msg(recv_msg, msg);
4530 		list_add_tail(&recv_msg->link, &intf->waiting_events);
4531 		intf->waiting_events_count++;
4532 	} else if (!intf->event_msg_printed) {
4533 		/*
4534 		 * There's too many things in the queue, discard this
4535 		 * message.
4536 		 */
4537 		dev_warn(intf->si_dev,
4538 			 "Event queue full, discarding incoming events\n");
4539 		intf->event_msg_printed = 1;
4540 	}
4541 
4542  out:
4543 	mutex_unlock(&intf->events_mutex);
4544 
4545 	return rv;
4546 }
4547 
4548 static int handle_bmc_rsp(struct ipmi_smi *intf,
4549 			  struct ipmi_smi_msg *msg)
4550 {
4551 	struct ipmi_recv_msg *recv_msg;
4552 	struct ipmi_system_interface_addr *smi_addr;
4553 
4554 	recv_msg = msg->recv_msg;
4555 	if (recv_msg == NULL) {
4556 		dev_warn(intf->si_dev,
4557 			 "IPMI SMI message received with no owner. This could be because of a malformed message, or because of a hardware error.  Contact your hardware vendor for assistance.\n");
4558 		return 0;
4559 	}
4560 
4561 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
4562 	recv_msg->msgid = msg->msgid;
4563 	smi_addr = ((struct ipmi_system_interface_addr *)
4564 		    &recv_msg->addr);
4565 	smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4566 	smi_addr->channel = IPMI_BMC_CHANNEL;
4567 	smi_addr->lun = msg->rsp[0] & 3;
4568 	recv_msg->msg.netfn = msg->rsp[0] >> 2;
4569 	recv_msg->msg.cmd = msg->rsp[1];
4570 	memcpy(recv_msg->msg_data, &msg->rsp[2], msg->rsp_size - 2);
4571 	recv_msg->msg.data = recv_msg->msg_data;
4572 	recv_msg->msg.data_len = msg->rsp_size - 2;
4573 	deliver_local_response(intf, recv_msg);
4574 
4575 	return 0;
4576 }
4577 
4578 /*
4579  * Handle a received message.  Return 1 if the message should be requeued,
4580  * 0 if the message should be freed, or -1 if the message should not
4581  * be freed or requeued.
4582  */
4583 static int handle_one_recv_msg(struct ipmi_smi *intf,
4584 			       struct ipmi_smi_msg *msg)
4585 {
4586 	int requeue = 0;
4587 	int chan;
4588 	unsigned char cc;
4589 	bool is_cmd = !((msg->rsp[0] >> 2) & 1);
4590 
4591 	dev_dbg(intf->si_dev, "Recv: %*ph\n", msg->rsp_size, msg->rsp);
4592 
4593 	if (msg->rsp_size < 2) {
4594 		/* Message is too small to be correct. */
4595 		dev_warn_ratelimited(intf->si_dev,
4596 				     "BMC returned too small a message for netfn %x cmd %x, got %d bytes\n",
4597 				     (msg->data[0] >> 2) | 1,
4598 				     msg->data[1], msg->rsp_size);
4599 
4600 return_unspecified:
4601 		/* Generate an error response for the message. */
4602 		msg->rsp[0] = msg->data[0] | (1 << 2);
4603 		msg->rsp[1] = msg->data[1];
4604 		msg->rsp[2] = IPMI_ERR_UNSPECIFIED;
4605 		msg->rsp_size = 3;
4606 	} else if (msg->type == IPMI_SMI_MSG_TYPE_IPMB_DIRECT) {
4607 		/* commands must have at least 4 bytes, responses 5. */
4608 		if (is_cmd && (msg->rsp_size < 4)) {
4609 			ipmi_inc_stat(intf, invalid_commands);
4610 			goto out;
4611 		}
4612 		if (!is_cmd && (msg->rsp_size < 5)) {
4613 			ipmi_inc_stat(intf, invalid_ipmb_responses);
4614 			/* Construct a valid error response. */
4615 			msg->rsp[0] = msg->data[0] & 0xfc; /* NetFN */
4616 			msg->rsp[0] |= (1 << 2); /* Make it a response */
4617 			msg->rsp[0] |= msg->data[2] & 3; /* rqLUN */
4618 			msg->rsp[1] = msg->data[1]; /* Addr */
4619 			msg->rsp[2] = msg->data[2] & 0xfc; /* rqSeq */
4620 			msg->rsp[2] |= msg->data[0] & 0x3; /* rsLUN */
4621 			msg->rsp[3] = msg->data[3]; /* Cmd */
4622 			msg->rsp[4] = IPMI_ERR_UNSPECIFIED;
4623 			msg->rsp_size = 5;
4624 		}
4625 	} else if ((msg->data_size >= 2)
4626 	    && (msg->data[0] == (IPMI_NETFN_APP_REQUEST << 2))
4627 	    && (msg->data[1] == IPMI_SEND_MSG_CMD)
4628 	    && (msg->recv_msg == NULL)) {
4629 
4630 		if (intf->in_shutdown || intf->run_to_completion)
4631 			goto out;
4632 
4633 		/*
4634 		 * This is the local response to a command send, start
4635 		 * the timer for these.  The recv_msg will not be
4636 		 * NULL if this is a response send, and we will let
4637 		 * response sends just go through.
4638 		 */
4639 
4640 		/*
4641 		 * Check for errors, if we get certain errors (ones
4642 		 * that mean basically we can try again later), we
4643 		 * ignore them and start the timer.  Otherwise we
4644 		 * report the error immediately.
4645 		 */
4646 		if ((msg->rsp_size >= 3) && (msg->rsp[2] != 0)
4647 		    && (msg->rsp[2] != IPMI_NODE_BUSY_ERR)
4648 		    && (msg->rsp[2] != IPMI_LOST_ARBITRATION_ERR)
4649 		    && (msg->rsp[2] != IPMI_BUS_ERR)
4650 		    && (msg->rsp[2] != IPMI_NAK_ON_WRITE_ERR)) {
4651 			int ch = msg->rsp[3] & 0xf;
4652 			struct ipmi_channel *chans;
4653 
4654 			/* Got an error sending the message, handle it. */
4655 
4656 			chans = READ_ONCE(intf->channel_list)->c;
4657 			if ((chans[ch].medium == IPMI_CHANNEL_MEDIUM_8023LAN)
4658 			    || (chans[ch].medium == IPMI_CHANNEL_MEDIUM_ASYNC))
4659 				ipmi_inc_stat(intf, sent_lan_command_errs);
4660 			else
4661 				ipmi_inc_stat(intf, sent_ipmb_command_errs);
4662 			intf_err_seq(intf, msg->msgid, msg->rsp[2]);
4663 		} else
4664 			/* The message was sent, start the timer. */
4665 			intf_start_seq_timer(intf, msg->msgid);
4666 		requeue = 0;
4667 		goto out;
4668 	} else if (((msg->rsp[0] >> 2) != ((msg->data[0] >> 2) | 1))
4669 		   || (msg->rsp[1] != msg->data[1])) {
4670 		/*
4671 		 * The NetFN and Command in the response is not even
4672 		 * marginally correct.
4673 		 */
4674 		dev_warn_ratelimited(intf->si_dev,
4675 				     "BMC returned incorrect response, expected netfn %x cmd %x, got netfn %x cmd %x\n",
4676 				     (msg->data[0] >> 2) | 1, msg->data[1],
4677 				     msg->rsp[0] >> 2, msg->rsp[1]);
4678 
4679 		goto return_unspecified;
4680 	}
4681 
4682 	if (msg->type == IPMI_SMI_MSG_TYPE_IPMB_DIRECT) {
4683 		if ((msg->data[0] >> 2) & 1) {
4684 			/* It's a response to a sent response. */
4685 			chan = 0;
4686 			cc = msg->rsp[4];
4687 			goto process_response_response;
4688 		}
4689 		if (is_cmd)
4690 			requeue = handle_ipmb_direct_rcv_cmd(intf, msg);
4691 		else
4692 			requeue = handle_ipmb_direct_rcv_rsp(intf, msg);
4693 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4694 		   && (msg->rsp[1] == IPMI_SEND_MSG_CMD)
4695 		   && (msg->recv_msg != NULL)) {
4696 		/*
4697 		 * It's a response to a response we sent.  For this we
4698 		 * deliver a send message response to the user.
4699 		 */
4700 		struct ipmi_recv_msg *recv_msg;
4701 
4702 		if (intf->run_to_completion)
4703 			goto out;
4704 
4705 		chan = msg->data[2] & 0x0f;
4706 		if (chan >= IPMI_MAX_CHANNELS)
4707 			/* Invalid channel number */
4708 			goto out;
4709 		cc = msg->rsp[2];
4710 
4711 process_response_response:
4712 		recv_msg = msg->recv_msg;
4713 
4714 		requeue = 0;
4715 		if (!recv_msg)
4716 			goto out;
4717 
4718 		recv_msg->recv_type = IPMI_RESPONSE_RESPONSE_TYPE;
4719 		recv_msg->msg.data = recv_msg->msg_data;
4720 		recv_msg->msg_data[0] = cc;
4721 		recv_msg->msg.data_len = 1;
4722 		deliver_local_response(intf, recv_msg);
4723 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4724 		   && (msg->rsp[1] == IPMI_GET_MSG_CMD)) {
4725 		struct ipmi_channel   *chans;
4726 
4727 		if (intf->run_to_completion)
4728 			goto out;
4729 
4730 		/* It's from the receive queue. */
4731 		chan = msg->rsp[3] & 0xf;
4732 		if (chan >= IPMI_MAX_CHANNELS) {
4733 			/* Invalid channel number */
4734 			requeue = 0;
4735 			goto out;
4736 		}
4737 
4738 		/*
4739 		 * We need to make sure the channels have been initialized.
4740 		 * The channel_handler routine will set the "curr_channel"
4741 		 * equal to or greater than IPMI_MAX_CHANNELS when all the
4742 		 * channels for this interface have been initialized.
4743 		 */
4744 		if (!intf->channels_ready) {
4745 			requeue = 0; /* Throw the message away */
4746 			goto out;
4747 		}
4748 
4749 		chans = READ_ONCE(intf->channel_list)->c;
4750 
4751 		switch (chans[chan].medium) {
4752 		case IPMI_CHANNEL_MEDIUM_IPMB:
4753 			if (msg->rsp[4] & 0x04) {
4754 				/*
4755 				 * It's a response, so find the
4756 				 * requesting message and send it up.
4757 				 */
4758 				requeue = handle_ipmb_get_msg_rsp(intf, msg);
4759 			} else {
4760 				/*
4761 				 * It's a command to the SMS from some other
4762 				 * entity.  Handle that.
4763 				 */
4764 				requeue = handle_ipmb_get_msg_cmd(intf, msg);
4765 			}
4766 			break;
4767 
4768 		case IPMI_CHANNEL_MEDIUM_8023LAN:
4769 		case IPMI_CHANNEL_MEDIUM_ASYNC:
4770 			if (msg->rsp[6] & 0x04) {
4771 				/*
4772 				 * It's a response, so find the
4773 				 * requesting message and send it up.
4774 				 */
4775 				requeue = handle_lan_get_msg_rsp(intf, msg);
4776 			} else {
4777 				/*
4778 				 * It's a command to the SMS from some other
4779 				 * entity.  Handle that.
4780 				 */
4781 				requeue = handle_lan_get_msg_cmd(intf, msg);
4782 			}
4783 			break;
4784 
4785 		default:
4786 			/* Check for OEM Channels.  Clients had better
4787 			   register for these commands. */
4788 			if ((chans[chan].medium >= IPMI_CHANNEL_MEDIUM_OEM_MIN)
4789 			    && (chans[chan].medium
4790 				<= IPMI_CHANNEL_MEDIUM_OEM_MAX)) {
4791 				requeue = handle_oem_get_msg_cmd(intf, msg);
4792 			} else {
4793 				/*
4794 				 * We don't handle the channel type, so just
4795 				 * free the message.
4796 				 */
4797 				requeue = 0;
4798 			}
4799 		}
4800 
4801 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4802 		   && (msg->rsp[1] == IPMI_READ_EVENT_MSG_BUFFER_CMD)) {
4803 		/* It's an asynchronous event. */
4804 		if (intf->run_to_completion)
4805 			goto out;
4806 
4807 		requeue = handle_read_event_rsp(intf, msg);
4808 	} else {
4809 		/* It's a response from the local BMC. */
4810 		requeue = handle_bmc_rsp(intf, msg);
4811 	}
4812 
4813  out:
4814 	return requeue;
4815 }
4816 
4817 /*
4818  * If there are messages in the queue or pretimeouts, handle them.
4819  */
4820 static void handle_new_recv_msgs(struct ipmi_smi *intf)
4821 {
4822 	struct ipmi_smi_msg *smi_msg;
4823 	unsigned long flags = 0;
4824 	int rv;
4825 	int run_to_completion = READ_ONCE(intf->run_to_completion);
4826 
4827 	/* See if any waiting messages need to be processed. */
4828 	if (!run_to_completion)
4829 		spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4830 	while (!list_empty(&intf->waiting_rcv_msgs)) {
4831 		smi_msg = list_entry(intf->waiting_rcv_msgs.next,
4832 				     struct ipmi_smi_msg, link);
4833 		list_del(&smi_msg->link);
4834 		if (!run_to_completion)
4835 			spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
4836 					       flags);
4837 		rv = handle_one_recv_msg(intf, smi_msg);
4838 		if (!run_to_completion)
4839 			spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4840 		if (rv > 0) {
4841 			/*
4842 			 * To preserve message order, quit if we
4843 			 * can't handle a message.  Add the message
4844 			 * back at the head, this is safe because this
4845 			 * workqueue is the only thing that pulls the
4846 			 * messages.
4847 			 */
4848 			list_add(&smi_msg->link, &intf->waiting_rcv_msgs);
4849 			break;
4850 		} else {
4851 			if (rv == 0)
4852 				/* Message handled */
4853 				ipmi_free_smi_msg(smi_msg);
4854 			/* If rv < 0, fatal error, del but don't free. */
4855 		}
4856 	}
4857 	if (!run_to_completion)
4858 		spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock, flags);
4859 }
4860 
4861 static void smi_work(struct work_struct *t)
4862 {
4863 	unsigned long flags = 0; /* keep us warning-free. */
4864 	struct ipmi_smi *intf = from_work(intf, t, smi_work);
4865 	int run_to_completion = READ_ONCE(intf->run_to_completion);
4866 	struct ipmi_smi_msg *newmsg = NULL;
4867 	struct ipmi_recv_msg *msg, *msg2;
4868 	int cc;
4869 
4870 	/*
4871 	 * Start the next message if available.
4872 	 *
4873 	 * Do this here, not in the actual receiver, because we may deadlock
4874 	 * because the lower layer is allowed to hold locks while calling
4875 	 * message delivery.
4876 	 */
4877 restart:
4878 	ipmi_lock_xmit_msgs(intf, run_to_completion, &flags);
4879 	if (intf->curr_msg == NULL && !intf->in_shutdown) {
4880 		struct list_head *entry = NULL;
4881 
4882 		/* Pick the high priority queue first. */
4883 		if (!list_empty(&intf->hp_xmit_msgs))
4884 			entry = intf->hp_xmit_msgs.next;
4885 		else if (!list_empty(&intf->xmit_msgs))
4886 			entry = intf->xmit_msgs.next;
4887 
4888 		if (entry) {
4889 			list_del(entry);
4890 			newmsg = list_entry(entry, struct ipmi_smi_msg, link);
4891 			intf->curr_msg = newmsg;
4892 		}
4893 	}
4894 	ipmi_unlock_xmit_msgs(intf, run_to_completion, &flags);
4895 
4896 	if (newmsg) {
4897 		cc = intf->handlers->sender(intf->send_info, newmsg);
4898 		if (cc) {
4899 			if (newmsg->recv_msg)
4900 				deliver_err_response(intf,
4901 						     newmsg->recv_msg, cc);
4902 			ipmi_lock_xmit_msgs(intf, run_to_completion, &flags);
4903 			intf->curr_msg = NULL;
4904 			ipmi_unlock_xmit_msgs(intf, run_to_completion, &flags);
4905 			ipmi_free_smi_msg(newmsg);
4906 			newmsg = NULL;
4907 			goto restart;
4908 		}
4909 	}
4910 
4911 	handle_new_recv_msgs(intf);
4912 
4913 	/* Nothing below applies during panic time. */
4914 	if (run_to_completion)
4915 		return;
4916 
4917 	/*
4918 	 * If the pretimout count is non-zero, decrement one from it and
4919 	 * deliver pretimeouts to all the users.
4920 	 */
4921 	if (atomic_add_unless(&intf->watchdog_pretimeouts_to_deliver, -1, 0)) {
4922 		struct ipmi_user *user;
4923 
4924 		mutex_lock(&intf->users_mutex);
4925 		list_for_each_entry(user, &intf->users, link) {
4926 			if (user->handler->ipmi_watchdog_pretimeout)
4927 				user->handler->ipmi_watchdog_pretimeout(
4928 					user->handler_data);
4929 		}
4930 		mutex_unlock(&intf->users_mutex);
4931 	}
4932 
4933 	/*
4934 	 * Freeing the message can cause a user to be released, which
4935 	 * can then cause the interface to be freed.  Make sure that
4936 	 * doesn't happen until we are ready.
4937 	 */
4938 	kref_get(&intf->refcount);
4939 
4940 	mutex_lock(&intf->user_msgs_mutex);
4941 	list_for_each_entry_safe(msg, msg2, &intf->user_msgs, link) {
4942 		struct ipmi_user *user = msg->user;
4943 
4944 		list_del(&msg->link);
4945 
4946 		if (refcount_read(&user->destroyed) == 0)
4947 			ipmi_free_recv_msg(msg);
4948 		else
4949 			user->handler->ipmi_recv_hndl(msg, user->handler_data);
4950 	}
4951 	mutex_unlock(&intf->user_msgs_mutex);
4952 
4953 	kref_put(&intf->refcount, intf_free);
4954 }
4955 
4956 /* Handle a new message from the lower layer. */
4957 void ipmi_smi_msg_received(struct ipmi_smi *intf,
4958 			   struct ipmi_smi_msg *msg)
4959 {
4960 	unsigned long flags = 0; /* keep us warning-free. */
4961 	int run_to_completion = READ_ONCE(intf->run_to_completion);
4962 
4963 	/*
4964 	 * To preserve message order, we keep a queue and deliver from
4965 	 * a workqueue.
4966 	 */
4967 	if (!run_to_completion)
4968 		spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4969 	list_add_tail(&msg->link, &intf->waiting_rcv_msgs);
4970 	if (!run_to_completion)
4971 		spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
4972 				       flags);
4973 
4974 	ipmi_lock_xmit_msgs(intf, run_to_completion, &flags);
4975 	/*
4976 	 * We can get an asynchronous event or receive message in addition
4977 	 * to commands we send.
4978 	 */
4979 	if (msg == intf->curr_msg)
4980 		intf->curr_msg = NULL;
4981 	ipmi_unlock_xmit_msgs(intf, run_to_completion, &flags);
4982 
4983 	if (run_to_completion)
4984 		smi_work(&intf->smi_work);
4985 	else
4986 		queue_work(system_percpu_wq, &intf->smi_work);
4987 }
4988 EXPORT_SYMBOL(ipmi_smi_msg_received);
4989 
4990 void ipmi_smi_watchdog_pretimeout(struct ipmi_smi *intf)
4991 {
4992 	if (intf->in_shutdown)
4993 		return;
4994 
4995 	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 1);
4996 	queue_work(system_percpu_wq, &intf->smi_work);
4997 }
4998 EXPORT_SYMBOL(ipmi_smi_watchdog_pretimeout);
4999 
5000 static struct ipmi_smi_msg *
5001 smi_from_recv_msg(struct ipmi_smi *intf, struct ipmi_recv_msg *recv_msg,
5002 		  unsigned char seq, long seqid)
5003 {
5004 	struct ipmi_smi_msg *smi_msg = ipmi_alloc_smi_msg();
5005 	if (!smi_msg)
5006 		/*
5007 		 * If we can't allocate the message, then just return, we
5008 		 * get 4 retries, so this should be ok.
5009 		 */
5010 		return NULL;
5011 
5012 	memcpy(smi_msg->data, recv_msg->msg.data, recv_msg->msg.data_len);
5013 	smi_msg->data_size = recv_msg->msg.data_len;
5014 	smi_msg->msgid = STORE_SEQ_IN_MSGID(seq, seqid);
5015 
5016 	dev_dbg(intf->si_dev, "Resend: %*ph\n",
5017 		smi_msg->data_size, smi_msg->data);
5018 
5019 	return smi_msg;
5020 }
5021 
5022 static void check_msg_timeout(struct ipmi_smi *intf, struct seq_table *ent,
5023 			      struct list_head *timeouts,
5024 			      unsigned long timeout_period,
5025 			      int slot, bool *need_timer)
5026 {
5027 	struct ipmi_recv_msg *msg;
5028 
5029 	if (intf->in_shutdown)
5030 		return;
5031 
5032 	if (!ent->inuse)
5033 		return;
5034 
5035 	if (timeout_period < ent->timeout) {
5036 		ent->timeout -= timeout_period;
5037 		*need_timer = true;
5038 		return;
5039 	}
5040 
5041 	if (ent->retries_left == 0) {
5042 		/* The message has used all its retries. */
5043 		ent->inuse = 0;
5044 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
5045 		msg = ent->recv_msg;
5046 		list_add_tail(&msg->link, timeouts);
5047 		if (ent->broadcast)
5048 			ipmi_inc_stat(intf, timed_out_ipmb_broadcasts);
5049 		else if (is_lan_addr(&ent->recv_msg->addr))
5050 			ipmi_inc_stat(intf, timed_out_lan_commands);
5051 		else
5052 			ipmi_inc_stat(intf, timed_out_ipmb_commands);
5053 	} else {
5054 		struct ipmi_smi_msg *smi_msg;
5055 		/* More retries, send again. */
5056 
5057 		*need_timer = true;
5058 
5059 		/*
5060 		 * Start with the max timer, set to normal timer after
5061 		 * the message is sent.
5062 		 */
5063 		ent->timeout = MAX_MSG_TIMEOUT;
5064 		ent->retries_left--;
5065 		smi_msg = smi_from_recv_msg(intf, ent->recv_msg, slot,
5066 					    ent->seqid);
5067 		if (!smi_msg) {
5068 			if (is_lan_addr(&ent->recv_msg->addr))
5069 				ipmi_inc_stat(intf,
5070 					      dropped_rexmit_lan_commands);
5071 			else
5072 				ipmi_inc_stat(intf,
5073 					      dropped_rexmit_ipmb_commands);
5074 			return;
5075 		}
5076 
5077 		mutex_unlock(&intf->seq_lock);
5078 
5079 		/*
5080 		 * Send the new message.  We send with a zero
5081 		 * priority.  It timed out, I doubt time is that
5082 		 * critical now, and high priority messages are really
5083 		 * only for messages to the local MC, which don't get
5084 		 * resent.
5085 		 */
5086 		if (intf->handlers) {
5087 			if (is_lan_addr(&ent->recv_msg->addr))
5088 				ipmi_inc_stat(intf,
5089 					      retransmitted_lan_commands);
5090 			else
5091 				ipmi_inc_stat(intf,
5092 					      retransmitted_ipmb_commands);
5093 
5094 			/* If this fails we'll retry later or timeout. */
5095 			if (smi_send(intf, intf->handlers, smi_msg, 0) != IPMI_CC_NO_ERROR) {
5096 				/* But fix the timeout. */
5097 				intf_start_seq_timer(intf, smi_msg->msgid);
5098 				ipmi_free_smi_msg(smi_msg);
5099 			}
5100 		} else
5101 			ipmi_free_smi_msg(smi_msg);
5102 
5103 		mutex_lock(&intf->seq_lock);
5104 	}
5105 }
5106 
5107 static bool ipmi_timeout_handler(struct ipmi_smi *intf,
5108 				 unsigned long timeout_period)
5109 {
5110 	LIST_HEAD(timeouts);
5111 	struct ipmi_recv_msg *msg, *msg2;
5112 	unsigned long        flags;
5113 	int                  i;
5114 	bool                 need_timer = false;
5115 
5116 	if (!intf->bmc_registered) {
5117 		kref_get(&intf->refcount);
5118 		if (!schedule_work(&intf->bmc_reg_work)) {
5119 			kref_put(&intf->refcount, intf_free);
5120 			need_timer = true;
5121 		}
5122 	}
5123 
5124 	/*
5125 	 * Go through the seq table and find any messages that
5126 	 * have timed out, putting them in the timeouts
5127 	 * list.
5128 	 */
5129 	mutex_lock(&intf->seq_lock);
5130 	if (intf->ipmb_maintenance_mode_timeout) {
5131 		if (intf->ipmb_maintenance_mode_timeout <= timeout_period)
5132 			intf->ipmb_maintenance_mode_timeout = 0;
5133 		else
5134 			intf->ipmb_maintenance_mode_timeout -= timeout_period;
5135 	}
5136 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++)
5137 		check_msg_timeout(intf, &intf->seq_table[i],
5138 				  &timeouts, timeout_period, i,
5139 				  &need_timer);
5140 	mutex_unlock(&intf->seq_lock);
5141 
5142 	list_for_each_entry_safe(msg, msg2, &timeouts, link)
5143 		deliver_err_response(intf, msg, IPMI_TIMEOUT_COMPLETION_CODE);
5144 
5145 	/*
5146 	 * Maintenance mode handling.  Check the timeout
5147 	 * optimistically before we claim the lock.  It may
5148 	 * mean a timeout gets missed occasionally, but that
5149 	 * only means the timeout gets extended by one period
5150 	 * in that case.  No big deal, and it avoids the lock
5151 	 * most of the time.
5152 	 */
5153 	if (intf->auto_maintenance_timeout > 0) {
5154 		spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
5155 		if (intf->auto_maintenance_timeout > 0) {
5156 			intf->auto_maintenance_timeout
5157 				-= timeout_period;
5158 			if (!intf->maintenance_mode
5159 			    && (intf->auto_maintenance_timeout <= 0)) {
5160 				intf->maintenance_mode_state =
5161 					IPMI_MAINTENANCE_MODE_STATE_OFF;
5162 				intf->auto_maintenance_timeout = 0;
5163 				maintenance_mode_update(intf);
5164 			}
5165 		}
5166 		spin_unlock_irqrestore(&intf->maintenance_mode_lock,
5167 				       flags);
5168 	}
5169 
5170 	queue_work(system_percpu_wq, &intf->smi_work);
5171 
5172 	return need_timer;
5173 }
5174 
5175 static void ipmi_request_event(struct ipmi_smi *intf)
5176 {
5177 	/* No event requests when in maintenance mode. */
5178 	if (intf->maintenance_mode_state)
5179 		return;
5180 
5181 	if (!intf->in_shutdown)
5182 		intf->handlers->request_events(intf->send_info);
5183 }
5184 
5185 static atomic_t stop_operation;
5186 
5187 static void ipmi_timeout_work(struct work_struct *work)
5188 {
5189 	if (atomic_read(&stop_operation))
5190 		return;
5191 
5192 	struct ipmi_smi *intf;
5193 	bool need_timer = false;
5194 
5195 	if (atomic_read(&stop_operation))
5196 		return;
5197 
5198 	mutex_lock(&ipmi_interfaces_mutex);
5199 	list_for_each_entry(intf, &ipmi_interfaces, link) {
5200 		if (atomic_read(&intf->event_waiters)) {
5201 			intf->ticks_to_req_ev--;
5202 			if (intf->ticks_to_req_ev == 0) {
5203 				ipmi_request_event(intf);
5204 				intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
5205 			}
5206 			need_timer = true;
5207 		}
5208 		if (intf->maintenance_mode_state)
5209 			need_timer = true;
5210 
5211 		need_timer |= ipmi_timeout_handler(intf, IPMI_TIMEOUT_TIME);
5212 	}
5213 	mutex_unlock(&ipmi_interfaces_mutex);
5214 
5215 	if (need_timer)
5216 		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
5217 }
5218 
5219 static DECLARE_WORK(ipmi_timer_work, ipmi_timeout_work);
5220 
5221 static void ipmi_timeout(struct timer_list *unused)
5222 {
5223 	if (atomic_read(&stop_operation))
5224 		return;
5225 
5226 	queue_work(system_percpu_wq, &ipmi_timer_work);
5227 }
5228 
5229 static void need_waiter(struct ipmi_smi *intf)
5230 {
5231 	/* Racy, but worst case we start the timer twice. */
5232 	if (!timer_pending(&ipmi_timer))
5233 		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
5234 }
5235 
5236 static atomic_t smi_msg_inuse_count = ATOMIC_INIT(0);
5237 static atomic_t recv_msg_inuse_count = ATOMIC_INIT(0);
5238 
5239 static void free_smi_msg(struct ipmi_smi_msg *msg)
5240 {
5241 	atomic_dec(&smi_msg_inuse_count);
5242 	/* Try to keep as much stuff out of the panic path as possible. */
5243 	if (!oops_in_progress)
5244 		kfree(msg);
5245 }
5246 
5247 struct ipmi_smi_msg *ipmi_alloc_smi_msg(void)
5248 {
5249 	struct ipmi_smi_msg *rv;
5250 	rv = kmalloc_obj(struct ipmi_smi_msg, GFP_ATOMIC);
5251 	if (rv) {
5252 		rv->done = free_smi_msg;
5253 		rv->recv_msg = NULL;
5254 		rv->type = IPMI_SMI_MSG_TYPE_NORMAL;
5255 		atomic_inc(&smi_msg_inuse_count);
5256 	}
5257 	return rv;
5258 }
5259 EXPORT_SYMBOL(ipmi_alloc_smi_msg);
5260 
5261 static void free_recv_msg(struct ipmi_recv_msg *msg)
5262 {
5263 	atomic_dec(&recv_msg_inuse_count);
5264 	/* Try to keep as much stuff out of the panic path as possible. */
5265 	if (!oops_in_progress)
5266 		kfree(msg);
5267 }
5268 
5269 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(struct ipmi_user *user)
5270 {
5271 	struct ipmi_recv_msg *rv;
5272 
5273 	if (user) {
5274 		if (atomic_add_return(1, &user->nr_msgs) > max_msgs_per_user) {
5275 			atomic_dec(&user->nr_msgs);
5276 			return ERR_PTR(-EBUSY);
5277 		}
5278 	}
5279 
5280 	rv = kmalloc_obj(struct ipmi_recv_msg, GFP_ATOMIC);
5281 	if (!rv) {
5282 		if (user)
5283 			atomic_dec(&user->nr_msgs);
5284 		return ERR_PTR(-ENOMEM);
5285 	}
5286 
5287 	rv->user = user;
5288 	rv->done = free_recv_msg;
5289 	if (user)
5290 		kref_get(&user->refcount);
5291 	atomic_inc(&recv_msg_inuse_count);
5292 	return rv;
5293 }
5294 
5295 void ipmi_free_recv_msg(struct ipmi_recv_msg *msg)
5296 {
5297 	if (msg->user && !oops_in_progress) {
5298 		atomic_dec(&msg->user->nr_msgs);
5299 		kref_put(&msg->user->refcount, free_ipmi_user);
5300 	}
5301 	msg->done(msg);
5302 }
5303 EXPORT_SYMBOL(ipmi_free_recv_msg);
5304 
5305 static void ipmi_set_recv_msg_user(struct ipmi_recv_msg *msg,
5306 				   struct ipmi_user *user)
5307 {
5308 	WARN_ON_ONCE(msg->user); /* User should not be set. */
5309 	msg->user = user;
5310 	atomic_inc(&user->nr_msgs);
5311 	kref_get(&user->refcount);
5312 }
5313 
5314 static atomic_t panic_done_count = ATOMIC_INIT(0);
5315 
5316 static void dummy_smi_done_handler(struct ipmi_smi_msg *msg)
5317 {
5318 	atomic_dec(&panic_done_count);
5319 }
5320 
5321 static void dummy_recv_done_handler(struct ipmi_recv_msg *msg)
5322 {
5323 	atomic_dec(&panic_done_count);
5324 }
5325 
5326 /*
5327  * Inside a panic, send a message and wait for a response.
5328  */
5329 static void _ipmi_panic_request_and_wait(struct ipmi_smi *intf,
5330 					 struct ipmi_addr *addr,
5331 					 struct kernel_ipmi_msg *msg)
5332 {
5333 	struct ipmi_smi_msg  smi_msg;
5334 	struct ipmi_recv_msg recv_msg;
5335 	int rv;
5336 
5337 	smi_msg.done = dummy_smi_done_handler;
5338 	recv_msg.done = dummy_recv_done_handler;
5339 	atomic_add(2, &panic_done_count);
5340 	rv = i_ipmi_request(NULL,
5341 			    intf,
5342 			    addr,
5343 			    0,
5344 			    msg,
5345 			    intf,
5346 			    &smi_msg,
5347 			    &recv_msg,
5348 			    0,
5349 			    intf->addrinfo[0].address,
5350 			    intf->addrinfo[0].lun,
5351 			    0, 1); /* Don't retry, and don't wait. */
5352 	if (rv)
5353 		atomic_sub(2, &panic_done_count);
5354 	else if (intf->handlers->flush_messages)
5355 		intf->handlers->flush_messages(intf->send_info);
5356 
5357 	while (atomic_read(&panic_done_count) != 0)
5358 		ipmi_poll(intf);
5359 }
5360 
5361 void ipmi_panic_request_and_wait(struct ipmi_user *user,
5362 				 struct ipmi_addr *addr,
5363 				 struct kernel_ipmi_msg *msg)
5364 {
5365 	user->intf->run_to_completion = 1;
5366 	_ipmi_panic_request_and_wait(user->intf, addr, msg);
5367 }
5368 EXPORT_SYMBOL(ipmi_panic_request_and_wait);
5369 
5370 static void event_receiver_fetcher(struct ipmi_smi *intf,
5371 				   struct ipmi_recv_msg *msg)
5372 {
5373 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
5374 	    && (msg->msg.netfn == IPMI_NETFN_SENSOR_EVENT_RESPONSE)
5375 	    && (msg->msg.cmd == IPMI_GET_EVENT_RECEIVER_CMD)
5376 	    && (msg->msg.data[0] == IPMI_CC_NO_ERROR)) {
5377 		/* A get event receiver command, save it. */
5378 		intf->event_receiver = msg->msg.data[1];
5379 		intf->event_receiver_lun = msg->msg.data[2] & 0x3;
5380 	}
5381 }
5382 
5383 static void device_id_fetcher(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
5384 {
5385 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
5386 	    && (msg->msg.netfn == IPMI_NETFN_APP_RESPONSE)
5387 	    && (msg->msg.cmd == IPMI_GET_DEVICE_ID_CMD)
5388 	    && (msg->msg.data[0] == IPMI_CC_NO_ERROR)) {
5389 		/*
5390 		 * A get device id command, save if we are an event
5391 		 * receiver or generator.
5392 		 */
5393 		intf->local_sel_device = (msg->msg.data[6] >> 2) & 1;
5394 		intf->local_event_generator = (msg->msg.data[6] >> 5) & 1;
5395 	}
5396 }
5397 
5398 static void send_panic_events(struct ipmi_smi *intf, char *str)
5399 {
5400 	struct kernel_ipmi_msg msg;
5401 	unsigned char data[16];
5402 	struct ipmi_system_interface_addr *si;
5403 	struct ipmi_addr addr;
5404 	char *p = str;
5405 	struct ipmi_ipmb_addr *ipmb;
5406 	int j;
5407 
5408 	if (ipmi_send_panic_event == IPMI_SEND_PANIC_EVENT_NONE)
5409 		return;
5410 
5411 	si = (struct ipmi_system_interface_addr *) &addr;
5412 	si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
5413 	si->channel = IPMI_BMC_CHANNEL;
5414 	si->lun = 0;
5415 
5416 	/* Fill in an event telling that we have failed. */
5417 	msg.netfn = 0x04; /* Sensor or Event. */
5418 	msg.cmd = 2; /* Platform event command. */
5419 	msg.data = data;
5420 	msg.data_len = 8;
5421 	data[0] = 0x41; /* Kernel generator ID, IPMI table 5-4 */
5422 	data[1] = 0x03; /* This is for IPMI 1.0. */
5423 	data[2] = 0x20; /* OS Critical Stop, IPMI table 36-3 */
5424 	data[4] = 0x6f; /* Sensor specific, IPMI table 36-1 */
5425 	data[5] = 0xa1; /* Runtime stop OEM bytes 2 & 3. */
5426 
5427 	/*
5428 	 * Put a few breadcrumbs in.  Hopefully later we can add more things
5429 	 * to make the panic events more useful.
5430 	 */
5431 	if (str) {
5432 		data[3] = str[0];
5433 		data[6] = str[1];
5434 		data[7] = str[2];
5435 	}
5436 
5437 	/* Send the event announcing the panic. */
5438 	_ipmi_panic_request_and_wait(intf, &addr, &msg);
5439 
5440 	/*
5441 	 * On every interface, dump a bunch of OEM event holding the
5442 	 * string.
5443 	 */
5444 	if (ipmi_send_panic_event != IPMI_SEND_PANIC_EVENT_STRING || !str)
5445 		return;
5446 
5447 	/*
5448 	 * intf_num is used as an marker to tell if the
5449 	 * interface is valid.  Thus we need a read barrier to
5450 	 * make sure data fetched before checking intf_num
5451 	 * won't be used.
5452 	 */
5453 	smp_rmb();
5454 
5455 	/*
5456 	 * First job here is to figure out where to send the
5457 	 * OEM events.  There's no way in IPMI to send OEM
5458 	 * events using an event send command, so we have to
5459 	 * find the SEL to put them in and stick them in
5460 	 * there.
5461 	 */
5462 
5463 	/* Get capabilities from the get device id. */
5464 	intf->local_sel_device = 0;
5465 	intf->local_event_generator = 0;
5466 	intf->event_receiver = 0;
5467 
5468 	/* Request the device info from the local MC. */
5469 	msg.netfn = IPMI_NETFN_APP_REQUEST;
5470 	msg.cmd = IPMI_GET_DEVICE_ID_CMD;
5471 	msg.data = NULL;
5472 	msg.data_len = 0;
5473 	intf->null_user_handler = device_id_fetcher;
5474 	_ipmi_panic_request_and_wait(intf, &addr, &msg);
5475 
5476 	if (intf->local_event_generator) {
5477 		/* Request the event receiver from the local MC. */
5478 		msg.netfn = IPMI_NETFN_SENSOR_EVENT_REQUEST;
5479 		msg.cmd = IPMI_GET_EVENT_RECEIVER_CMD;
5480 		msg.data = NULL;
5481 		msg.data_len = 0;
5482 		intf->null_user_handler = event_receiver_fetcher;
5483 		_ipmi_panic_request_and_wait(intf, &addr, &msg);
5484 	}
5485 	intf->null_user_handler = NULL;
5486 
5487 	/*
5488 	 * Validate the event receiver.  The low bit must not
5489 	 * be 1 (it must be a valid IPMB address), it cannot
5490 	 * be zero, and it must not be my address.
5491 	 */
5492 	if (((intf->event_receiver & 1) == 0)
5493 	    && (intf->event_receiver != 0)
5494 	    && (intf->event_receiver != intf->addrinfo[0].address)) {
5495 		/*
5496 		 * The event receiver is valid, send an IPMB
5497 		 * message.
5498 		 */
5499 		ipmb = (struct ipmi_ipmb_addr *) &addr;
5500 		ipmb->addr_type = IPMI_IPMB_ADDR_TYPE;
5501 		ipmb->channel = 0; /* FIXME - is this right? */
5502 		ipmb->lun = intf->event_receiver_lun;
5503 		ipmb->slave_addr = intf->event_receiver;
5504 	} else if (intf->local_sel_device) {
5505 		/*
5506 		 * The event receiver was not valid (or was
5507 		 * me), but I am an SEL device, just dump it
5508 		 * in my SEL.
5509 		 */
5510 		si = (struct ipmi_system_interface_addr *) &addr;
5511 		si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
5512 		si->channel = IPMI_BMC_CHANNEL;
5513 		si->lun = 0;
5514 	} else
5515 		return; /* No where to send the event. */
5516 
5517 	msg.netfn = IPMI_NETFN_STORAGE_REQUEST; /* Storage. */
5518 	msg.cmd = IPMI_ADD_SEL_ENTRY_CMD;
5519 	msg.data = data;
5520 	msg.data_len = 16;
5521 
5522 	j = 0;
5523 	while (*p) {
5524 		int size = strnlen(p, 11);
5525 
5526 		data[0] = 0;
5527 		data[1] = 0;
5528 		data[2] = 0xf0; /* OEM event without timestamp. */
5529 		data[3] = intf->addrinfo[0].address;
5530 		data[4] = j++; /* sequence # */
5531 
5532 		memcpy_and_pad(data+5, 11, p, size, '\0');
5533 		p += size;
5534 
5535 		_ipmi_panic_request_and_wait(intf, &addr, &msg);
5536 	}
5537 }
5538 
5539 static int has_panicked;
5540 
5541 static int panic_event(struct notifier_block *this,
5542 		       unsigned long         event,
5543 		       void                  *ptr)
5544 {
5545 	struct ipmi_smi *intf;
5546 	struct ipmi_user *user;
5547 
5548 	if (has_panicked)
5549 		return NOTIFY_DONE;
5550 	has_panicked = 1;
5551 
5552 	/* For every registered interface, set it to run to completion. */
5553 	list_for_each_entry(intf, &ipmi_interfaces, link) {
5554 		if (!intf->handlers || intf->intf_num == -1)
5555 			/* Interface is not ready. */
5556 			continue;
5557 
5558 		if (!intf->handlers->poll)
5559 			continue;
5560 
5561 		/*
5562 		 * If we were interrupted while locking xmit_msgs_lock or
5563 		 * waiting_rcv_msgs_lock, the corresponding list may be
5564 		 * corrupted.  In this case, drop items on the list for
5565 		 * the safety.
5566 		 */
5567 		if (!spin_trylock(&intf->xmit_msgs_lock)) {
5568 			INIT_LIST_HEAD(&intf->xmit_msgs);
5569 			INIT_LIST_HEAD(&intf->hp_xmit_msgs);
5570 		} else
5571 			spin_unlock(&intf->xmit_msgs_lock);
5572 
5573 		if (!spin_trylock(&intf->waiting_rcv_msgs_lock))
5574 			INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
5575 		else
5576 			spin_unlock(&intf->waiting_rcv_msgs_lock);
5577 
5578 		intf->run_to_completion = 1;
5579 		if (intf->handlers->set_run_to_completion)
5580 			intf->handlers->set_run_to_completion(intf->send_info,
5581 							      1);
5582 
5583 		list_for_each_entry(user, &intf->users, link) {
5584 			if (user->handler->ipmi_panic_handler)
5585 				user->handler->ipmi_panic_handler(
5586 					user->handler_data);
5587 		}
5588 
5589 		send_panic_events(intf, ptr);
5590 	}
5591 
5592 	return NOTIFY_DONE;
5593 }
5594 
5595 /* Must be called with ipmi_interfaces_mutex held. */
5596 static int ipmi_register_driver(void)
5597 {
5598 	int rv;
5599 
5600 	if (drvregistered)
5601 		return 0;
5602 
5603 	rv = driver_register(&ipmidriver.driver);
5604 	if (rv)
5605 		pr_err("Could not register IPMI driver\n");
5606 	else
5607 		drvregistered = true;
5608 	return rv;
5609 }
5610 
5611 static struct notifier_block panic_block = {
5612 	.notifier_call	= panic_event,
5613 	.next		= NULL,
5614 	.priority	= 200	/* priority: INT_MAX >= x >= 0 */
5615 };
5616 
5617 static int ipmi_init_msghandler(void)
5618 {
5619 	int rv;
5620 
5621 	mutex_lock(&ipmi_interfaces_mutex);
5622 	rv = ipmi_register_driver();
5623 	if (rv)
5624 		goto out;
5625 	if (initialized)
5626 		goto out;
5627 
5628 	bmc_remove_work_wq = create_singlethread_workqueue("ipmi-msghandler-remove-wq");
5629 	if (!bmc_remove_work_wq) {
5630 		pr_err("unable to create ipmi-msghandler-remove-wq workqueue");
5631 		rv = -ENOMEM;
5632 		goto out;
5633 	}
5634 
5635 	timer_setup(&ipmi_timer, ipmi_timeout, 0);
5636 	mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
5637 
5638 	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
5639 
5640 	initialized = true;
5641 
5642 out:
5643 	mutex_unlock(&ipmi_interfaces_mutex);
5644 	return rv;
5645 }
5646 
5647 static int __init ipmi_init_msghandler_mod(void)
5648 {
5649 	int rv;
5650 
5651 	pr_info("version " IPMI_DRIVER_VERSION "\n");
5652 
5653 	mutex_lock(&ipmi_interfaces_mutex);
5654 	rv = ipmi_register_driver();
5655 	mutex_unlock(&ipmi_interfaces_mutex);
5656 
5657 	return rv;
5658 }
5659 
5660 static void __exit cleanup_ipmi(void)
5661 {
5662 	int count;
5663 
5664 	if (initialized) {
5665 		destroy_workqueue(bmc_remove_work_wq);
5666 
5667 		atomic_notifier_chain_unregister(&panic_notifier_list,
5668 						 &panic_block);
5669 
5670 		/*
5671 		 * This can't be called if any interfaces exist, so no worry
5672 		 * about shutting down the interfaces.
5673 		 */
5674 
5675 		/*
5676 		 * Tell the timer to stop, then wait for it to stop.  This
5677 		 * avoids problems with race conditions removing the timer
5678 		 * here.
5679 		 */
5680 		atomic_set(&stop_operation, 1);
5681 		timer_delete_sync(&ipmi_timer);
5682 		cancel_work_sync(&ipmi_timer_work);
5683 
5684 		initialized = false;
5685 
5686 		/* Check for buffer leaks. */
5687 		count = atomic_read(&smi_msg_inuse_count);
5688 		if (count != 0)
5689 			pr_warn("SMI message count %d at exit\n", count);
5690 		count = atomic_read(&recv_msg_inuse_count);
5691 		if (count != 0)
5692 			pr_warn("recv message count %d at exit\n", count);
5693 	}
5694 	if (drvregistered)
5695 		driver_unregister(&ipmidriver.driver);
5696 }
5697 module_exit(cleanup_ipmi);
5698 
5699 module_init(ipmi_init_msghandler_mod);
5700 MODULE_LICENSE("GPL");
5701 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
5702 MODULE_DESCRIPTION("Incoming and outgoing message routing for an IPMI interface.");
5703 MODULE_VERSION(IPMI_DRIVER_VERSION);
5704 MODULE_SOFTDEP("post: ipmi_devintf");
5705