xref: /linux/drivers/char/ipmi/ipmi_msghandler.c (revision 68a052239fc4b351e961f698b824f7654a346091)
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, struct ipmi_device_id *id);
603 
604 static void free_ipmi_user(struct kref *ref)
605 {
606 	struct ipmi_user *user = container_of(ref, struct ipmi_user, refcount);
607 	struct module *owner;
608 
609 	owner = user->intf->owner;
610 	kref_put(&user->intf->refcount, intf_free);
611 	module_put(owner);
612 	vfree(user);
613 }
614 
615 static void release_ipmi_user(struct ipmi_user *user)
616 {
617 	kref_put(&user->refcount, free_ipmi_user);
618 }
619 
620 static struct ipmi_user *acquire_ipmi_user(struct ipmi_user *user)
621 {
622 	if (!kref_get_unless_zero(&user->refcount))
623 		return NULL;
624 	return user;
625 }
626 
627 /*
628  * The driver model view of the IPMI messaging driver.
629  */
630 static struct platform_driver ipmidriver = {
631 	.driver = {
632 		.name = "ipmi",
633 		.bus = &platform_bus_type
634 	}
635 };
636 /*
637  * This mutex keeps us from adding the same BMC twice.
638  */
639 static DEFINE_MUTEX(ipmidriver_mutex);
640 
641 static LIST_HEAD(ipmi_interfaces);
642 static DEFINE_MUTEX(ipmi_interfaces_mutex);
643 
644 /*
645  * List of watchers that want to know when smi's are added and deleted.
646  */
647 static LIST_HEAD(smi_watchers);
648 static DEFINE_MUTEX(smi_watchers_mutex);
649 
650 #define ipmi_inc_stat(intf, stat) \
651 	atomic_inc(&(intf)->stats[IPMI_STAT_ ## stat])
652 #define ipmi_get_stat(intf, stat) \
653 	((unsigned int) atomic_read(&(intf)->stats[IPMI_STAT_ ## stat]))
654 
655 static const char * const addr_src_to_str[] = {
656 	"invalid", "hotmod", "hardcoded", "SPMI", "ACPI", "SMBIOS", "PCI",
657 	"device-tree", "platform"
658 };
659 
660 const char *ipmi_addr_src_to_str(enum ipmi_addr_src src)
661 {
662 	if (src >= SI_LAST)
663 		src = 0; /* Invalid */
664 	return addr_src_to_str[src];
665 }
666 EXPORT_SYMBOL(ipmi_addr_src_to_str);
667 
668 static int is_lan_addr(struct ipmi_addr *addr)
669 {
670 	return addr->addr_type == IPMI_LAN_ADDR_TYPE;
671 }
672 
673 static int is_ipmb_addr(struct ipmi_addr *addr)
674 {
675 	return addr->addr_type == IPMI_IPMB_ADDR_TYPE;
676 }
677 
678 static int is_ipmb_bcast_addr(struct ipmi_addr *addr)
679 {
680 	return addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE;
681 }
682 
683 static int is_ipmb_direct_addr(struct ipmi_addr *addr)
684 {
685 	return addr->addr_type == IPMI_IPMB_DIRECT_ADDR_TYPE;
686 }
687 
688 static void free_recv_msg_list(struct list_head *q)
689 {
690 	struct ipmi_recv_msg *msg, *msg2;
691 
692 	list_for_each_entry_safe(msg, msg2, q, link) {
693 		list_del(&msg->link);
694 		ipmi_free_recv_msg(msg);
695 	}
696 }
697 
698 static void free_smi_msg_list(struct list_head *q)
699 {
700 	struct ipmi_smi_msg *msg, *msg2;
701 
702 	list_for_each_entry_safe(msg, msg2, q, link) {
703 		list_del(&msg->link);
704 		ipmi_free_smi_msg(msg);
705 	}
706 }
707 
708 static void intf_free(struct kref *ref)
709 {
710 	struct ipmi_smi *intf = container_of(ref, struct ipmi_smi, refcount);
711 	int              i;
712 	struct cmd_rcvr  *rcvr, *rcvr2;
713 
714 	free_smi_msg_list(&intf->waiting_rcv_msgs);
715 	free_recv_msg_list(&intf->waiting_events);
716 
717 	/*
718 	 * Wholesale remove all the entries from the list in the
719 	 * interface.  No need for locks, this is single-threaded.
720 	 */
721 	list_for_each_entry_safe(rcvr, rcvr2, &intf->cmd_rcvrs, link)
722 		kfree(rcvr);
723 
724 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
725 		if ((intf->seq_table[i].inuse)
726 					&& (intf->seq_table[i].recv_msg))
727 			ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
728 	}
729 
730 	kfree(intf);
731 }
732 
733 int ipmi_smi_watcher_register(struct ipmi_smi_watcher *watcher)
734 {
735 	struct ipmi_smi *intf;
736 	unsigned int count = 0, i;
737 	int *interfaces = NULL;
738 	struct device **devices = NULL;
739 	int rv = 0;
740 
741 	/*
742 	 * Make sure the driver is actually initialized, this handles
743 	 * problems with initialization order.
744 	 */
745 	rv = ipmi_init_msghandler();
746 	if (rv)
747 		return rv;
748 
749 	mutex_lock(&smi_watchers_mutex);
750 
751 	list_add(&watcher->link, &smi_watchers);
752 
753 	/*
754 	 * Build an array of ipmi interfaces and fill it in, and
755 	 * another array of the devices.  We can't call the callback
756 	 * with ipmi_interfaces_mutex held.  smi_watchers_mutex will
757 	 * keep things in order for the user.
758 	 */
759 	mutex_lock(&ipmi_interfaces_mutex);
760 	list_for_each_entry(intf, &ipmi_interfaces, link)
761 		count++;
762 	if (count > 0) {
763 		interfaces = kmalloc_array(count, sizeof(*interfaces),
764 					   GFP_KERNEL);
765 		if (!interfaces) {
766 			rv = -ENOMEM;
767 		} else {
768 			devices = kmalloc_array(count, sizeof(*devices),
769 						GFP_KERNEL);
770 			if (!devices) {
771 				kfree(interfaces);
772 				interfaces = NULL;
773 				rv = -ENOMEM;
774 			}
775 		}
776 		count = 0;
777 	}
778 	if (interfaces) {
779 		list_for_each_entry(intf, &ipmi_interfaces, link) {
780 			int intf_num = READ_ONCE(intf->intf_num);
781 
782 			if (intf_num == -1)
783 				continue;
784 			devices[count] = intf->si_dev;
785 			interfaces[count++] = intf_num;
786 		}
787 	}
788 	mutex_unlock(&ipmi_interfaces_mutex);
789 
790 	if (interfaces) {
791 		for (i = 0; i < count; i++)
792 			watcher->new_smi(interfaces[i], devices[i]);
793 		kfree(interfaces);
794 		kfree(devices);
795 	}
796 
797 	mutex_unlock(&smi_watchers_mutex);
798 
799 	return rv;
800 }
801 EXPORT_SYMBOL(ipmi_smi_watcher_register);
802 
803 int ipmi_smi_watcher_unregister(struct ipmi_smi_watcher *watcher)
804 {
805 	mutex_lock(&smi_watchers_mutex);
806 	list_del(&watcher->link);
807 	mutex_unlock(&smi_watchers_mutex);
808 	return 0;
809 }
810 EXPORT_SYMBOL(ipmi_smi_watcher_unregister);
811 
812 static void
813 call_smi_watchers(int i, struct device *dev)
814 {
815 	struct ipmi_smi_watcher *w;
816 
817 	list_for_each_entry(w, &smi_watchers, link) {
818 		if (try_module_get(w->owner)) {
819 			w->new_smi(i, dev);
820 			module_put(w->owner);
821 		}
822 	}
823 }
824 
825 static int
826 ipmi_addr_equal(struct ipmi_addr *addr1, struct ipmi_addr *addr2)
827 {
828 	if (addr1->addr_type != addr2->addr_type)
829 		return 0;
830 
831 	if (addr1->channel != addr2->channel)
832 		return 0;
833 
834 	if (addr1->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
835 		struct ipmi_system_interface_addr *smi_addr1
836 		    = (struct ipmi_system_interface_addr *) addr1;
837 		struct ipmi_system_interface_addr *smi_addr2
838 		    = (struct ipmi_system_interface_addr *) addr2;
839 		return (smi_addr1->lun == smi_addr2->lun);
840 	}
841 
842 	if (is_ipmb_addr(addr1) || is_ipmb_bcast_addr(addr1)) {
843 		struct ipmi_ipmb_addr *ipmb_addr1
844 		    = (struct ipmi_ipmb_addr *) addr1;
845 		struct ipmi_ipmb_addr *ipmb_addr2
846 		    = (struct ipmi_ipmb_addr *) addr2;
847 
848 		return ((ipmb_addr1->slave_addr == ipmb_addr2->slave_addr)
849 			&& (ipmb_addr1->lun == ipmb_addr2->lun));
850 	}
851 
852 	if (is_ipmb_direct_addr(addr1)) {
853 		struct ipmi_ipmb_direct_addr *daddr1
854 			= (struct ipmi_ipmb_direct_addr *) addr1;
855 		struct ipmi_ipmb_direct_addr *daddr2
856 			= (struct ipmi_ipmb_direct_addr *) addr2;
857 
858 		return daddr1->slave_addr == daddr2->slave_addr &&
859 			daddr1->rq_lun == daddr2->rq_lun &&
860 			daddr1->rs_lun == daddr2->rs_lun;
861 	}
862 
863 	if (is_lan_addr(addr1)) {
864 		struct ipmi_lan_addr *lan_addr1
865 			= (struct ipmi_lan_addr *) addr1;
866 		struct ipmi_lan_addr *lan_addr2
867 		    = (struct ipmi_lan_addr *) addr2;
868 
869 		return ((lan_addr1->remote_SWID == lan_addr2->remote_SWID)
870 			&& (lan_addr1->local_SWID == lan_addr2->local_SWID)
871 			&& (lan_addr1->session_handle
872 			    == lan_addr2->session_handle)
873 			&& (lan_addr1->lun == lan_addr2->lun));
874 	}
875 
876 	return 1;
877 }
878 
879 int ipmi_validate_addr(struct ipmi_addr *addr, int len)
880 {
881 	if (len < sizeof(struct ipmi_system_interface_addr))
882 		return -EINVAL;
883 
884 	if (addr->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
885 		if (addr->channel != IPMI_BMC_CHANNEL)
886 			return -EINVAL;
887 		return 0;
888 	}
889 
890 	if ((addr->channel == IPMI_BMC_CHANNEL)
891 	    || (addr->channel >= IPMI_MAX_CHANNELS)
892 	    || (addr->channel < 0))
893 		return -EINVAL;
894 
895 	if (is_ipmb_addr(addr) || is_ipmb_bcast_addr(addr)) {
896 		if (len < sizeof(struct ipmi_ipmb_addr))
897 			return -EINVAL;
898 		return 0;
899 	}
900 
901 	if (is_ipmb_direct_addr(addr)) {
902 		struct ipmi_ipmb_direct_addr *daddr = (void *) addr;
903 
904 		if (addr->channel != 0)
905 			return -EINVAL;
906 		if (len < sizeof(struct ipmi_ipmb_direct_addr))
907 			return -EINVAL;
908 
909 		if (daddr->slave_addr & 0x01)
910 			return -EINVAL;
911 		if (daddr->rq_lun >= 4)
912 			return -EINVAL;
913 		if (daddr->rs_lun >= 4)
914 			return -EINVAL;
915 		return 0;
916 	}
917 
918 	if (is_lan_addr(addr)) {
919 		if (len < sizeof(struct ipmi_lan_addr))
920 			return -EINVAL;
921 		return 0;
922 	}
923 
924 	return -EINVAL;
925 }
926 EXPORT_SYMBOL(ipmi_validate_addr);
927 
928 unsigned int ipmi_addr_length(int addr_type)
929 {
930 	if (addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
931 		return sizeof(struct ipmi_system_interface_addr);
932 
933 	if ((addr_type == IPMI_IPMB_ADDR_TYPE)
934 			|| (addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE))
935 		return sizeof(struct ipmi_ipmb_addr);
936 
937 	if (addr_type == IPMI_IPMB_DIRECT_ADDR_TYPE)
938 		return sizeof(struct ipmi_ipmb_direct_addr);
939 
940 	if (addr_type == IPMI_LAN_ADDR_TYPE)
941 		return sizeof(struct ipmi_lan_addr);
942 
943 	return 0;
944 }
945 EXPORT_SYMBOL(ipmi_addr_length);
946 
947 static int deliver_response(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
948 {
949 	int rv = 0;
950 
951 	if (!msg->user) {
952 		/* Special handling for NULL users. */
953 		if (intf->null_user_handler) {
954 			intf->null_user_handler(intf, msg);
955 		} else {
956 			/* No handler, so give up. */
957 			rv = -EINVAL;
958 		}
959 		ipmi_free_recv_msg(msg);
960 	} else if (oops_in_progress) {
961 		/*
962 		 * If we are running in the panic context, calling the
963 		 * receive handler doesn't much meaning and has a deadlock
964 		 * risk.  At this moment, simply skip it in that case.
965 		 */
966 		ipmi_free_recv_msg(msg);
967 	} else {
968 		/*
969 		 * Deliver it in smi_work.  The message will hold a
970 		 * refcount to the user.
971 		 */
972 		mutex_lock(&intf->user_msgs_mutex);
973 		list_add_tail(&msg->link, &intf->user_msgs);
974 		mutex_unlock(&intf->user_msgs_mutex);
975 		queue_work(system_wq, &intf->smi_work);
976 	}
977 
978 	return rv;
979 }
980 
981 static void deliver_local_response(struct ipmi_smi *intf,
982 				   struct ipmi_recv_msg *msg)
983 {
984 	if (deliver_response(intf, msg))
985 		ipmi_inc_stat(intf, unhandled_local_responses);
986 	else
987 		ipmi_inc_stat(intf, handled_local_responses);
988 }
989 
990 static void deliver_err_response(struct ipmi_smi *intf,
991 				 struct ipmi_recv_msg *msg, int err)
992 {
993 	msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
994 	msg->msg_data[0] = err;
995 	msg->msg.netfn |= 1; /* Convert to a response. */
996 	msg->msg.data_len = 1;
997 	msg->msg.data = msg->msg_data;
998 	deliver_local_response(intf, msg);
999 }
1000 
1001 static void smi_add_watch(struct ipmi_smi *intf, unsigned int flags)
1002 {
1003 	unsigned long iflags;
1004 
1005 	if (!intf->handlers->set_need_watch)
1006 		return;
1007 
1008 	spin_lock_irqsave(&intf->watch_lock, iflags);
1009 	if (flags & IPMI_WATCH_MASK_CHECK_MESSAGES)
1010 		intf->response_waiters++;
1011 
1012 	if (flags & IPMI_WATCH_MASK_CHECK_WATCHDOG)
1013 		intf->watchdog_waiters++;
1014 
1015 	if (flags & IPMI_WATCH_MASK_CHECK_COMMANDS)
1016 		intf->command_waiters++;
1017 
1018 	if ((intf->last_watch_mask & flags) != flags) {
1019 		intf->last_watch_mask |= flags;
1020 		intf->handlers->set_need_watch(intf->send_info,
1021 					       intf->last_watch_mask);
1022 	}
1023 	spin_unlock_irqrestore(&intf->watch_lock, iflags);
1024 }
1025 
1026 static void smi_remove_watch(struct ipmi_smi *intf, unsigned int flags)
1027 {
1028 	unsigned long iflags;
1029 
1030 	if (!intf->handlers->set_need_watch)
1031 		return;
1032 
1033 	spin_lock_irqsave(&intf->watch_lock, iflags);
1034 	if (flags & IPMI_WATCH_MASK_CHECK_MESSAGES)
1035 		intf->response_waiters--;
1036 
1037 	if (flags & IPMI_WATCH_MASK_CHECK_WATCHDOG)
1038 		intf->watchdog_waiters--;
1039 
1040 	if (flags & IPMI_WATCH_MASK_CHECK_COMMANDS)
1041 		intf->command_waiters--;
1042 
1043 	flags = 0;
1044 	if (intf->response_waiters)
1045 		flags |= IPMI_WATCH_MASK_CHECK_MESSAGES;
1046 	if (intf->watchdog_waiters)
1047 		flags |= IPMI_WATCH_MASK_CHECK_WATCHDOG;
1048 	if (intf->command_waiters)
1049 		flags |= IPMI_WATCH_MASK_CHECK_COMMANDS;
1050 
1051 	if (intf->last_watch_mask != flags) {
1052 		intf->last_watch_mask = flags;
1053 		intf->handlers->set_need_watch(intf->send_info,
1054 					       intf->last_watch_mask);
1055 	}
1056 	spin_unlock_irqrestore(&intf->watch_lock, iflags);
1057 }
1058 
1059 /*
1060  * Find the next sequence number not being used and add the given
1061  * message with the given timeout to the sequence table.  This must be
1062  * called with the interface's seq_lock held.
1063  */
1064 static int intf_next_seq(struct ipmi_smi      *intf,
1065 			 struct ipmi_recv_msg *recv_msg,
1066 			 unsigned long        timeout,
1067 			 int                  retries,
1068 			 int                  broadcast,
1069 			 unsigned char        *seq,
1070 			 long                 *seqid)
1071 {
1072 	int          rv = 0;
1073 	unsigned int i;
1074 
1075 	if (timeout == 0)
1076 		timeout = default_retry_ms;
1077 	if (retries < 0)
1078 		retries = default_max_retries;
1079 
1080 	for (i = intf->curr_seq; (i+1)%IPMI_IPMB_NUM_SEQ != intf->curr_seq;
1081 					i = (i+1)%IPMI_IPMB_NUM_SEQ) {
1082 		if (!intf->seq_table[i].inuse)
1083 			break;
1084 	}
1085 
1086 	if (!intf->seq_table[i].inuse) {
1087 		intf->seq_table[i].recv_msg = recv_msg;
1088 
1089 		/*
1090 		 * Start with the maximum timeout, when the send response
1091 		 * comes in we will start the real timer.
1092 		 */
1093 		intf->seq_table[i].timeout = MAX_MSG_TIMEOUT;
1094 		intf->seq_table[i].orig_timeout = timeout;
1095 		intf->seq_table[i].retries_left = retries;
1096 		intf->seq_table[i].broadcast = broadcast;
1097 		intf->seq_table[i].inuse = 1;
1098 		intf->seq_table[i].seqid = NEXT_SEQID(intf->seq_table[i].seqid);
1099 		*seq = i;
1100 		*seqid = intf->seq_table[i].seqid;
1101 		intf->curr_seq = (i+1)%IPMI_IPMB_NUM_SEQ;
1102 		smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1103 		need_waiter(intf);
1104 	} else {
1105 		rv = -EAGAIN;
1106 	}
1107 
1108 	return rv;
1109 }
1110 
1111 /*
1112  * Return the receive message for the given sequence number and
1113  * release the sequence number so it can be reused.  Some other data
1114  * is passed in to be sure the message matches up correctly (to help
1115  * guard against message coming in after their timeout and the
1116  * sequence number being reused).
1117  */
1118 static int intf_find_seq(struct ipmi_smi      *intf,
1119 			 unsigned char        seq,
1120 			 short                channel,
1121 			 unsigned char        cmd,
1122 			 unsigned char        netfn,
1123 			 struct ipmi_addr     *addr,
1124 			 struct ipmi_recv_msg **recv_msg)
1125 {
1126 	int           rv = -ENODEV;
1127 
1128 	if (seq >= IPMI_IPMB_NUM_SEQ)
1129 		return -EINVAL;
1130 
1131 	mutex_lock(&intf->seq_lock);
1132 	if (intf->seq_table[seq].inuse) {
1133 		struct ipmi_recv_msg *msg = intf->seq_table[seq].recv_msg;
1134 
1135 		if ((msg->addr.channel == channel) && (msg->msg.cmd == cmd)
1136 				&& (msg->msg.netfn == netfn)
1137 				&& (ipmi_addr_equal(addr, &msg->addr))) {
1138 			*recv_msg = msg;
1139 			intf->seq_table[seq].inuse = 0;
1140 			smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1141 			rv = 0;
1142 		}
1143 	}
1144 	mutex_unlock(&intf->seq_lock);
1145 
1146 	return rv;
1147 }
1148 
1149 
1150 /* Start the timer for a specific sequence table entry. */
1151 static int intf_start_seq_timer(struct ipmi_smi *intf,
1152 				long       msgid)
1153 {
1154 	int           rv = -ENODEV;
1155 	unsigned char seq;
1156 	unsigned long seqid;
1157 
1158 
1159 	GET_SEQ_FROM_MSGID(msgid, seq, seqid);
1160 
1161 	mutex_lock(&intf->seq_lock);
1162 	/*
1163 	 * We do this verification because the user can be deleted
1164 	 * while a message is outstanding.
1165 	 */
1166 	if ((intf->seq_table[seq].inuse)
1167 				&& (intf->seq_table[seq].seqid == seqid)) {
1168 		struct seq_table *ent = &intf->seq_table[seq];
1169 		ent->timeout = ent->orig_timeout;
1170 		rv = 0;
1171 	}
1172 	mutex_unlock(&intf->seq_lock);
1173 
1174 	return rv;
1175 }
1176 
1177 /* Got an error for the send message for a specific sequence number. */
1178 static int intf_err_seq(struct ipmi_smi *intf,
1179 			long         msgid,
1180 			unsigned int err)
1181 {
1182 	int                  rv = -ENODEV;
1183 	unsigned char        seq;
1184 	unsigned long        seqid;
1185 	struct ipmi_recv_msg *msg = NULL;
1186 
1187 
1188 	GET_SEQ_FROM_MSGID(msgid, seq, seqid);
1189 
1190 	mutex_lock(&intf->seq_lock);
1191 	/*
1192 	 * We do this verification because the user can be deleted
1193 	 * while a message is outstanding.
1194 	 */
1195 	if ((intf->seq_table[seq].inuse)
1196 				&& (intf->seq_table[seq].seqid == seqid)) {
1197 		struct seq_table *ent = &intf->seq_table[seq];
1198 
1199 		ent->inuse = 0;
1200 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1201 		msg = ent->recv_msg;
1202 		rv = 0;
1203 	}
1204 	mutex_unlock(&intf->seq_lock);
1205 
1206 	if (msg)
1207 		deliver_err_response(intf, msg, err);
1208 
1209 	return rv;
1210 }
1211 
1212 int ipmi_create_user(unsigned int          if_num,
1213 		     const struct ipmi_user_hndl *handler,
1214 		     void                  *handler_data,
1215 		     struct ipmi_user      **user)
1216 {
1217 	struct ipmi_user *new_user = NULL;
1218 	int           rv = 0;
1219 	struct ipmi_smi *intf;
1220 
1221 	/*
1222 	 * There is no module usecount here, because it's not
1223 	 * required.  Since this can only be used by and called from
1224 	 * other modules, they will implicitly use this module, and
1225 	 * thus this can't be removed unless the other modules are
1226 	 * removed.
1227 	 */
1228 
1229 	if (handler == NULL)
1230 		return -EINVAL;
1231 
1232 	/*
1233 	 * Make sure the driver is actually initialized, this handles
1234 	 * problems with initialization order.
1235 	 */
1236 	rv = ipmi_init_msghandler();
1237 	if (rv)
1238 		return rv;
1239 
1240 	mutex_lock(&ipmi_interfaces_mutex);
1241 	list_for_each_entry(intf, &ipmi_interfaces, link) {
1242 		if (intf->intf_num == if_num)
1243 			goto found;
1244 	}
1245 	/* Not found, return an error */
1246 	rv = -EINVAL;
1247 	goto out_unlock;
1248 
1249  found:
1250 	if (intf->in_shutdown) {
1251 		rv = -ENODEV;
1252 		goto out_unlock;
1253 	}
1254 
1255 	if (atomic_add_return(1, &intf->nr_users) > max_users) {
1256 		rv = -EBUSY;
1257 		goto out_kfree;
1258 	}
1259 
1260 	new_user = vzalloc(sizeof(*new_user));
1261 	if (!new_user) {
1262 		rv = -ENOMEM;
1263 		goto out_kfree;
1264 	}
1265 
1266 	if (!try_module_get(intf->owner)) {
1267 		rv = -ENODEV;
1268 		goto out_kfree;
1269 	}
1270 
1271 	/* Note that each existing user holds a refcount to the interface. */
1272 	kref_get(&intf->refcount);
1273 
1274 	atomic_set(&new_user->nr_msgs, 0);
1275 	kref_init(&new_user->refcount);
1276 	refcount_set(&new_user->destroyed, 1);
1277 	kref_get(&new_user->refcount); /* Destroy owns a refcount. */
1278 	new_user->handler = handler;
1279 	new_user->handler_data = handler_data;
1280 	new_user->intf = intf;
1281 	new_user->gets_events = false;
1282 
1283 	mutex_lock(&intf->users_mutex);
1284 	mutex_lock(&intf->seq_lock);
1285 	list_add(&new_user->link, &intf->users);
1286 	mutex_unlock(&intf->seq_lock);
1287 	mutex_unlock(&intf->users_mutex);
1288 
1289 	if (handler->ipmi_watchdog_pretimeout)
1290 		/* User wants pretimeouts, so make sure to watch for them. */
1291 		smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_WATCHDOG);
1292 
1293 out_kfree:
1294 	if (rv) {
1295 		atomic_dec(&intf->nr_users);
1296 		vfree(new_user);
1297 	} else {
1298 		*user = new_user;
1299 	}
1300 out_unlock:
1301 	mutex_unlock(&ipmi_interfaces_mutex);
1302 	return rv;
1303 }
1304 EXPORT_SYMBOL(ipmi_create_user);
1305 
1306 int ipmi_get_smi_info(int if_num, struct ipmi_smi_info *data)
1307 {
1308 	int rv = -EINVAL;
1309 	struct ipmi_smi *intf;
1310 
1311 	mutex_lock(&ipmi_interfaces_mutex);
1312 	list_for_each_entry(intf, &ipmi_interfaces, link) {
1313 		if (intf->intf_num == if_num) {
1314 			if (!intf->handlers->get_smi_info)
1315 				rv = -ENOTTY;
1316 			else
1317 				rv = intf->handlers->get_smi_info(intf->send_info, data);
1318 			break;
1319 		}
1320 	}
1321 	mutex_unlock(&ipmi_interfaces_mutex);
1322 
1323 	return rv;
1324 }
1325 EXPORT_SYMBOL(ipmi_get_smi_info);
1326 
1327 /* Must be called with intf->users_mutex held. */
1328 static void _ipmi_destroy_user(struct ipmi_user *user)
1329 {
1330 	struct ipmi_smi  *intf = user->intf;
1331 	int              i;
1332 	struct cmd_rcvr  *rcvr;
1333 	struct cmd_rcvr  *rcvrs = NULL;
1334 	struct ipmi_recv_msg *msg, *msg2;
1335 
1336 	if (!refcount_dec_if_one(&user->destroyed))
1337 		return;
1338 
1339 	if (user->handler->shutdown)
1340 		user->handler->shutdown(user->handler_data);
1341 
1342 	if (user->handler->ipmi_watchdog_pretimeout)
1343 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_WATCHDOG);
1344 
1345 	if (user->gets_events)
1346 		atomic_dec(&intf->event_waiters);
1347 
1348 	/* Remove the user from the interface's list and sequence table. */
1349 	list_del(&user->link);
1350 	atomic_dec(&intf->nr_users);
1351 
1352 	mutex_lock(&intf->seq_lock);
1353 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
1354 		if (intf->seq_table[i].inuse
1355 		    && (intf->seq_table[i].recv_msg->user == user)) {
1356 			intf->seq_table[i].inuse = 0;
1357 			smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1358 			ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
1359 		}
1360 	}
1361 	mutex_unlock(&intf->seq_lock);
1362 
1363 	/*
1364 	 * Remove the user from the command receiver's table.  First
1365 	 * we build a list of everything (not using the standard link,
1366 	 * since other things may be using it till we do
1367 	 * synchronize_rcu()) then free everything in that list.
1368 	 */
1369 	mutex_lock(&intf->cmd_rcvrs_mutex);
1370 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1371 				lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1372 		if (rcvr->user == user) {
1373 			list_del_rcu(&rcvr->link);
1374 			rcvr->next = rcvrs;
1375 			rcvrs = rcvr;
1376 		}
1377 	}
1378 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1379 	while (rcvrs) {
1380 		rcvr = rcvrs;
1381 		rcvrs = rcvr->next;
1382 		kfree(rcvr);
1383 	}
1384 
1385 	mutex_lock(&intf->user_msgs_mutex);
1386 	list_for_each_entry_safe(msg, msg2, &intf->user_msgs, link) {
1387 		if (msg->user != user)
1388 			continue;
1389 		list_del(&msg->link);
1390 		ipmi_free_recv_msg(msg);
1391 	}
1392 	mutex_unlock(&intf->user_msgs_mutex);
1393 
1394 	release_ipmi_user(user);
1395 }
1396 
1397 void ipmi_destroy_user(struct ipmi_user *user)
1398 {
1399 	struct ipmi_smi *intf = user->intf;
1400 
1401 	mutex_lock(&intf->users_mutex);
1402 	_ipmi_destroy_user(user);
1403 	mutex_unlock(&intf->users_mutex);
1404 
1405 	kref_put(&user->refcount, free_ipmi_user);
1406 }
1407 EXPORT_SYMBOL(ipmi_destroy_user);
1408 
1409 int ipmi_get_version(struct ipmi_user *user,
1410 		     unsigned char *major,
1411 		     unsigned char *minor)
1412 {
1413 	struct ipmi_device_id id;
1414 	int rv;
1415 
1416 	user = acquire_ipmi_user(user);
1417 	if (!user)
1418 		return -ENODEV;
1419 
1420 	rv = bmc_get_device_id(user->intf, NULL, &id, NULL, NULL);
1421 	if (!rv) {
1422 		*major = ipmi_version_major(&id);
1423 		*minor = ipmi_version_minor(&id);
1424 	}
1425 	release_ipmi_user(user);
1426 
1427 	return rv;
1428 }
1429 EXPORT_SYMBOL(ipmi_get_version);
1430 
1431 int ipmi_set_my_address(struct ipmi_user *user,
1432 			unsigned int  channel,
1433 			unsigned char address)
1434 {
1435 	int rv = 0;
1436 
1437 	user = acquire_ipmi_user(user);
1438 	if (!user)
1439 		return -ENODEV;
1440 
1441 	if (channel >= IPMI_MAX_CHANNELS) {
1442 		rv = -EINVAL;
1443 	} else {
1444 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1445 		user->intf->addrinfo[channel].address = address;
1446 	}
1447 	release_ipmi_user(user);
1448 
1449 	return rv;
1450 }
1451 EXPORT_SYMBOL(ipmi_set_my_address);
1452 
1453 int ipmi_get_my_address(struct ipmi_user *user,
1454 			unsigned int  channel,
1455 			unsigned char *address)
1456 {
1457 	int rv = 0;
1458 
1459 	user = acquire_ipmi_user(user);
1460 	if (!user)
1461 		return -ENODEV;
1462 
1463 	if (channel >= IPMI_MAX_CHANNELS) {
1464 		rv = -EINVAL;
1465 	} else {
1466 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1467 		*address = user->intf->addrinfo[channel].address;
1468 	}
1469 	release_ipmi_user(user);
1470 
1471 	return rv;
1472 }
1473 EXPORT_SYMBOL(ipmi_get_my_address);
1474 
1475 int ipmi_set_my_LUN(struct ipmi_user *user,
1476 		    unsigned int  channel,
1477 		    unsigned char LUN)
1478 {
1479 	int rv = 0;
1480 
1481 	user = acquire_ipmi_user(user);
1482 	if (!user)
1483 		return -ENODEV;
1484 
1485 	if (channel >= IPMI_MAX_CHANNELS) {
1486 		rv = -EINVAL;
1487 	} else {
1488 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1489 		user->intf->addrinfo[channel].lun = LUN & 0x3;
1490 	}
1491 	release_ipmi_user(user);
1492 
1493 	return rv;
1494 }
1495 EXPORT_SYMBOL(ipmi_set_my_LUN);
1496 
1497 int ipmi_get_my_LUN(struct ipmi_user *user,
1498 		    unsigned int  channel,
1499 		    unsigned char *address)
1500 {
1501 	int rv = 0;
1502 
1503 	user = acquire_ipmi_user(user);
1504 	if (!user)
1505 		return -ENODEV;
1506 
1507 	if (channel >= IPMI_MAX_CHANNELS) {
1508 		rv = -EINVAL;
1509 	} else {
1510 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1511 		*address = user->intf->addrinfo[channel].lun;
1512 	}
1513 	release_ipmi_user(user);
1514 
1515 	return rv;
1516 }
1517 EXPORT_SYMBOL(ipmi_get_my_LUN);
1518 
1519 int ipmi_get_maintenance_mode(struct ipmi_user *user)
1520 {
1521 	int mode;
1522 	unsigned long flags;
1523 
1524 	user = acquire_ipmi_user(user);
1525 	if (!user)
1526 		return -ENODEV;
1527 
1528 	spin_lock_irqsave(&user->intf->maintenance_mode_lock, flags);
1529 	mode = user->intf->maintenance_mode;
1530 	spin_unlock_irqrestore(&user->intf->maintenance_mode_lock, flags);
1531 	release_ipmi_user(user);
1532 
1533 	return mode;
1534 }
1535 EXPORT_SYMBOL(ipmi_get_maintenance_mode);
1536 
1537 static void maintenance_mode_update(struct ipmi_smi *intf)
1538 {
1539 	if (intf->handlers->set_maintenance_mode)
1540 		/*
1541 		 * Lower level drivers only care about firmware mode
1542 		 * as it affects their timing.  They don't care about
1543 		 * reset, which disables all commands for a while.
1544 		 */
1545 		intf->handlers->set_maintenance_mode(
1546 			intf->send_info,
1547 			(intf->maintenance_mode_state ==
1548 			 IPMI_MAINTENANCE_MODE_STATE_FIRMWARE));
1549 }
1550 
1551 int ipmi_set_maintenance_mode(struct ipmi_user *user, int mode)
1552 {
1553 	int rv = 0;
1554 	unsigned long flags;
1555 	struct ipmi_smi *intf = user->intf;
1556 
1557 	user = acquire_ipmi_user(user);
1558 	if (!user)
1559 		return -ENODEV;
1560 
1561 	spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
1562 	if (intf->maintenance_mode != mode) {
1563 		switch (mode) {
1564 		case IPMI_MAINTENANCE_MODE_AUTO:
1565 			/* Just leave it alone. */
1566 			break;
1567 
1568 		case IPMI_MAINTENANCE_MODE_OFF:
1569 			intf->maintenance_mode_state =
1570 				IPMI_MAINTENANCE_MODE_STATE_OFF;
1571 			break;
1572 
1573 		case IPMI_MAINTENANCE_MODE_ON:
1574 			intf->maintenance_mode_state =
1575 				IPMI_MAINTENANCE_MODE_STATE_FIRMWARE;
1576 			break;
1577 
1578 		default:
1579 			rv = -EINVAL;
1580 			goto out_unlock;
1581 		}
1582 		intf->maintenance_mode = mode;
1583 
1584 		maintenance_mode_update(intf);
1585 	}
1586  out_unlock:
1587 	spin_unlock_irqrestore(&intf->maintenance_mode_lock, flags);
1588 	release_ipmi_user(user);
1589 
1590 	return rv;
1591 }
1592 EXPORT_SYMBOL(ipmi_set_maintenance_mode);
1593 
1594 int ipmi_set_gets_events(struct ipmi_user *user, bool val)
1595 {
1596 	struct ipmi_smi      *intf = user->intf;
1597 	struct ipmi_recv_msg *msg, *msg2;
1598 	struct list_head     msgs;
1599 
1600 	user = acquire_ipmi_user(user);
1601 	if (!user)
1602 		return -ENODEV;
1603 
1604 	INIT_LIST_HEAD(&msgs);
1605 
1606 	mutex_lock(&intf->events_mutex);
1607 	if (user->gets_events == val)
1608 		goto out;
1609 
1610 	user->gets_events = val;
1611 
1612 	if (val) {
1613 		if (atomic_inc_return(&intf->event_waiters) == 1)
1614 			need_waiter(intf);
1615 	} else {
1616 		atomic_dec(&intf->event_waiters);
1617 	}
1618 
1619 	/* Deliver any queued events. */
1620 	while (user->gets_events && !list_empty(&intf->waiting_events)) {
1621 		list_for_each_entry_safe(msg, msg2, &intf->waiting_events, link)
1622 			list_move_tail(&msg->link, &msgs);
1623 		intf->waiting_events_count = 0;
1624 		if (intf->event_msg_printed) {
1625 			dev_warn(intf->si_dev, "Event queue no longer full\n");
1626 			intf->event_msg_printed = 0;
1627 		}
1628 
1629 		list_for_each_entry_safe(msg, msg2, &msgs, link) {
1630 			ipmi_set_recv_msg_user(msg, user);
1631 			deliver_local_response(intf, msg);
1632 		}
1633 	}
1634 
1635  out:
1636 	mutex_unlock(&intf->events_mutex);
1637 	release_ipmi_user(user);
1638 
1639 	return 0;
1640 }
1641 EXPORT_SYMBOL(ipmi_set_gets_events);
1642 
1643 static struct cmd_rcvr *find_cmd_rcvr(struct ipmi_smi *intf,
1644 				      unsigned char netfn,
1645 				      unsigned char cmd,
1646 				      unsigned char chan)
1647 {
1648 	struct cmd_rcvr *rcvr;
1649 
1650 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1651 				lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1652 		if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
1653 					&& (rcvr->chans & (1 << chan)))
1654 			return rcvr;
1655 	}
1656 	return NULL;
1657 }
1658 
1659 static int is_cmd_rcvr_exclusive(struct ipmi_smi *intf,
1660 				 unsigned char netfn,
1661 				 unsigned char cmd,
1662 				 unsigned int  chans)
1663 {
1664 	struct cmd_rcvr *rcvr;
1665 
1666 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1667 				lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1668 		if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
1669 					&& (rcvr->chans & chans))
1670 			return 0;
1671 	}
1672 	return 1;
1673 }
1674 
1675 int ipmi_register_for_cmd(struct ipmi_user *user,
1676 			  unsigned char netfn,
1677 			  unsigned char cmd,
1678 			  unsigned int  chans)
1679 {
1680 	struct ipmi_smi *intf = user->intf;
1681 	struct cmd_rcvr *rcvr;
1682 	int rv = 0;
1683 
1684 	user = acquire_ipmi_user(user);
1685 	if (!user)
1686 		return -ENODEV;
1687 
1688 	rcvr = kmalloc(sizeof(*rcvr), GFP_KERNEL);
1689 	if (!rcvr) {
1690 		rv = -ENOMEM;
1691 		goto out_release;
1692 	}
1693 	rcvr->cmd = cmd;
1694 	rcvr->netfn = netfn;
1695 	rcvr->chans = chans;
1696 	rcvr->user = user;
1697 
1698 	mutex_lock(&intf->cmd_rcvrs_mutex);
1699 	/* Make sure the command/netfn is not already registered. */
1700 	if (!is_cmd_rcvr_exclusive(intf, netfn, cmd, chans)) {
1701 		rv = -EBUSY;
1702 		goto out_unlock;
1703 	}
1704 
1705 	smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS);
1706 
1707 	list_add_rcu(&rcvr->link, &intf->cmd_rcvrs);
1708 
1709 out_unlock:
1710 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1711 	if (rv)
1712 		kfree(rcvr);
1713 out_release:
1714 	release_ipmi_user(user);
1715 
1716 	return rv;
1717 }
1718 EXPORT_SYMBOL(ipmi_register_for_cmd);
1719 
1720 int ipmi_unregister_for_cmd(struct ipmi_user *user,
1721 			    unsigned char netfn,
1722 			    unsigned char cmd,
1723 			    unsigned int  chans)
1724 {
1725 	struct ipmi_smi *intf = user->intf;
1726 	struct cmd_rcvr *rcvr;
1727 	struct cmd_rcvr *rcvrs = NULL;
1728 	int i, rv = -ENOENT;
1729 
1730 	user = acquire_ipmi_user(user);
1731 	if (!user)
1732 		return -ENODEV;
1733 
1734 	mutex_lock(&intf->cmd_rcvrs_mutex);
1735 	for (i = 0; i < IPMI_NUM_CHANNELS; i++) {
1736 		if (((1 << i) & chans) == 0)
1737 			continue;
1738 		rcvr = find_cmd_rcvr(intf, netfn, cmd, i);
1739 		if (rcvr == NULL)
1740 			continue;
1741 		if (rcvr->user == user) {
1742 			rv = 0;
1743 			rcvr->chans &= ~chans;
1744 			if (rcvr->chans == 0) {
1745 				list_del_rcu(&rcvr->link);
1746 				rcvr->next = rcvrs;
1747 				rcvrs = rcvr;
1748 			}
1749 		}
1750 	}
1751 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1752 	synchronize_rcu();
1753 	release_ipmi_user(user);
1754 	while (rcvrs) {
1755 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS);
1756 		rcvr = rcvrs;
1757 		rcvrs = rcvr->next;
1758 		kfree(rcvr);
1759 	}
1760 
1761 	return rv;
1762 }
1763 EXPORT_SYMBOL(ipmi_unregister_for_cmd);
1764 
1765 unsigned char
1766 ipmb_checksum(unsigned char *data, int size)
1767 {
1768 	unsigned char csum = 0;
1769 
1770 	for (; size > 0; size--, data++)
1771 		csum += *data;
1772 
1773 	return -csum;
1774 }
1775 EXPORT_SYMBOL(ipmb_checksum);
1776 
1777 static inline void format_ipmb_msg(struct ipmi_smi_msg   *smi_msg,
1778 				   struct kernel_ipmi_msg *msg,
1779 				   struct ipmi_ipmb_addr *ipmb_addr,
1780 				   long                  msgid,
1781 				   unsigned char         ipmb_seq,
1782 				   int                   broadcast,
1783 				   unsigned char         source_address,
1784 				   unsigned char         source_lun)
1785 {
1786 	int i = broadcast;
1787 
1788 	/* Format the IPMB header data. */
1789 	smi_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
1790 	smi_msg->data[1] = IPMI_SEND_MSG_CMD;
1791 	smi_msg->data[2] = ipmb_addr->channel;
1792 	if (broadcast)
1793 		smi_msg->data[3] = 0;
1794 	smi_msg->data[i+3] = ipmb_addr->slave_addr;
1795 	smi_msg->data[i+4] = (msg->netfn << 2) | (ipmb_addr->lun & 0x3);
1796 	smi_msg->data[i+5] = ipmb_checksum(&smi_msg->data[i + 3], 2);
1797 	smi_msg->data[i+6] = source_address;
1798 	smi_msg->data[i+7] = (ipmb_seq << 2) | source_lun;
1799 	smi_msg->data[i+8] = msg->cmd;
1800 
1801 	/* Now tack on the data to the message. */
1802 	if (msg->data_len > 0)
1803 		memcpy(&smi_msg->data[i + 9], msg->data, msg->data_len);
1804 	smi_msg->data_size = msg->data_len + 9;
1805 
1806 	/* Now calculate the checksum and tack it on. */
1807 	smi_msg->data[i+smi_msg->data_size]
1808 		= ipmb_checksum(&smi_msg->data[i + 6], smi_msg->data_size - 6);
1809 
1810 	/*
1811 	 * Add on the checksum size and the offset from the
1812 	 * broadcast.
1813 	 */
1814 	smi_msg->data_size += 1 + i;
1815 
1816 	smi_msg->msgid = msgid;
1817 }
1818 
1819 static inline void format_lan_msg(struct ipmi_smi_msg   *smi_msg,
1820 				  struct kernel_ipmi_msg *msg,
1821 				  struct ipmi_lan_addr  *lan_addr,
1822 				  long                  msgid,
1823 				  unsigned char         ipmb_seq,
1824 				  unsigned char         source_lun)
1825 {
1826 	/* Format the IPMB header data. */
1827 	smi_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
1828 	smi_msg->data[1] = IPMI_SEND_MSG_CMD;
1829 	smi_msg->data[2] = lan_addr->channel;
1830 	smi_msg->data[3] = lan_addr->session_handle;
1831 	smi_msg->data[4] = lan_addr->remote_SWID;
1832 	smi_msg->data[5] = (msg->netfn << 2) | (lan_addr->lun & 0x3);
1833 	smi_msg->data[6] = ipmb_checksum(&smi_msg->data[4], 2);
1834 	smi_msg->data[7] = lan_addr->local_SWID;
1835 	smi_msg->data[8] = (ipmb_seq << 2) | source_lun;
1836 	smi_msg->data[9] = msg->cmd;
1837 
1838 	/* Now tack on the data to the message. */
1839 	if (msg->data_len > 0)
1840 		memcpy(&smi_msg->data[10], msg->data, msg->data_len);
1841 	smi_msg->data_size = msg->data_len + 10;
1842 
1843 	/* Now calculate the checksum and tack it on. */
1844 	smi_msg->data[smi_msg->data_size]
1845 		= ipmb_checksum(&smi_msg->data[7], smi_msg->data_size - 7);
1846 
1847 	/*
1848 	 * Add on the checksum size and the offset from the
1849 	 * broadcast.
1850 	 */
1851 	smi_msg->data_size += 1;
1852 
1853 	smi_msg->msgid = msgid;
1854 }
1855 
1856 static struct ipmi_smi_msg *smi_add_send_msg(struct ipmi_smi *intf,
1857 					     struct ipmi_smi_msg *smi_msg,
1858 					     int priority)
1859 {
1860 	if (intf->curr_msg) {
1861 		if (priority > 0)
1862 			list_add_tail(&smi_msg->link, &intf->hp_xmit_msgs);
1863 		else
1864 			list_add_tail(&smi_msg->link, &intf->xmit_msgs);
1865 		smi_msg = NULL;
1866 	} else {
1867 		intf->curr_msg = smi_msg;
1868 	}
1869 
1870 	return smi_msg;
1871 }
1872 
1873 static void smi_send(struct ipmi_smi *intf,
1874 		     const struct ipmi_smi_handlers *handlers,
1875 		     struct ipmi_smi_msg *smi_msg, int priority)
1876 {
1877 	int run_to_completion = READ_ONCE(intf->run_to_completion);
1878 	unsigned long flags = 0;
1879 
1880 	if (!run_to_completion)
1881 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
1882 	smi_msg = smi_add_send_msg(intf, smi_msg, priority);
1883 	if (!run_to_completion)
1884 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
1885 
1886 	if (smi_msg)
1887 		handlers->sender(intf->send_info, smi_msg);
1888 }
1889 
1890 static bool is_maintenance_mode_cmd(struct kernel_ipmi_msg *msg)
1891 {
1892 	return (((msg->netfn == IPMI_NETFN_APP_REQUEST)
1893 		 && ((msg->cmd == IPMI_COLD_RESET_CMD)
1894 		     || (msg->cmd == IPMI_WARM_RESET_CMD)))
1895 		|| (msg->netfn == IPMI_NETFN_FIRMWARE_REQUEST));
1896 }
1897 
1898 static int i_ipmi_req_sysintf(struct ipmi_smi        *intf,
1899 			      struct ipmi_addr       *addr,
1900 			      long                   msgid,
1901 			      struct kernel_ipmi_msg *msg,
1902 			      struct ipmi_smi_msg    *smi_msg,
1903 			      struct ipmi_recv_msg   *recv_msg,
1904 			      int                    retries,
1905 			      unsigned int           retry_time_ms)
1906 {
1907 	struct ipmi_system_interface_addr *smi_addr;
1908 
1909 	if (msg->netfn & 1)
1910 		/* Responses are not allowed to the SMI. */
1911 		return -EINVAL;
1912 
1913 	smi_addr = (struct ipmi_system_interface_addr *) addr;
1914 	if (smi_addr->lun > 3) {
1915 		ipmi_inc_stat(intf, sent_invalid_commands);
1916 		return -EINVAL;
1917 	}
1918 
1919 	memcpy(&recv_msg->addr, smi_addr, sizeof(*smi_addr));
1920 
1921 	if ((msg->netfn == IPMI_NETFN_APP_REQUEST)
1922 	    && ((msg->cmd == IPMI_SEND_MSG_CMD)
1923 		|| (msg->cmd == IPMI_GET_MSG_CMD)
1924 		|| (msg->cmd == IPMI_READ_EVENT_MSG_BUFFER_CMD))) {
1925 		/*
1926 		 * We don't let the user do these, since we manage
1927 		 * the sequence numbers.
1928 		 */
1929 		ipmi_inc_stat(intf, sent_invalid_commands);
1930 		return -EINVAL;
1931 	}
1932 
1933 	if (is_maintenance_mode_cmd(msg)) {
1934 		unsigned long flags;
1935 		int newst;
1936 
1937 		if (msg->netfn == IPMI_NETFN_FIRMWARE_REQUEST)
1938 			newst = IPMI_MAINTENANCE_MODE_STATE_FIRMWARE;
1939 		else
1940 			newst = IPMI_MAINTENANCE_MODE_STATE_RESET;
1941 
1942 		spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
1943 		intf->auto_maintenance_timeout = maintenance_mode_timeout_ms;
1944 		if (!intf->maintenance_mode
1945 				&& intf->maintenance_mode_state < newst) {
1946 			intf->maintenance_mode_state = newst;
1947 			maintenance_mode_update(intf);
1948 			mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
1949 		}
1950 		spin_unlock_irqrestore(&intf->maintenance_mode_lock,
1951 				       flags);
1952 	}
1953 
1954 	if (msg->data_len + 2 > IPMI_MAX_MSG_LENGTH) {
1955 		ipmi_inc_stat(intf, sent_invalid_commands);
1956 		return -EMSGSIZE;
1957 	}
1958 
1959 	smi_msg->data[0] = (msg->netfn << 2) | (smi_addr->lun & 0x3);
1960 	smi_msg->data[1] = msg->cmd;
1961 	smi_msg->msgid = msgid;
1962 	smi_msg->recv_msg = recv_msg;
1963 	if (msg->data_len > 0)
1964 		memcpy(&smi_msg->data[2], msg->data, msg->data_len);
1965 	smi_msg->data_size = msg->data_len + 2;
1966 	ipmi_inc_stat(intf, sent_local_commands);
1967 
1968 	return 0;
1969 }
1970 
1971 static int i_ipmi_req_ipmb(struct ipmi_smi        *intf,
1972 			   struct ipmi_addr       *addr,
1973 			   long                   msgid,
1974 			   struct kernel_ipmi_msg *msg,
1975 			   struct ipmi_smi_msg    *smi_msg,
1976 			   struct ipmi_recv_msg   *recv_msg,
1977 			   unsigned char          source_address,
1978 			   unsigned char          source_lun,
1979 			   int                    retries,
1980 			   unsigned int           retry_time_ms)
1981 {
1982 	struct ipmi_ipmb_addr *ipmb_addr;
1983 	unsigned char ipmb_seq;
1984 	long seqid;
1985 	int broadcast = 0;
1986 	struct ipmi_channel *chans;
1987 	int rv = 0;
1988 
1989 	if (addr->channel >= IPMI_MAX_CHANNELS) {
1990 		ipmi_inc_stat(intf, sent_invalid_commands);
1991 		return -EINVAL;
1992 	}
1993 
1994 	chans = READ_ONCE(intf->channel_list)->c;
1995 
1996 	if (chans[addr->channel].medium != IPMI_CHANNEL_MEDIUM_IPMB) {
1997 		ipmi_inc_stat(intf, sent_invalid_commands);
1998 		return -EINVAL;
1999 	}
2000 
2001 	if (addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE) {
2002 		/*
2003 		 * Broadcasts add a zero at the beginning of the
2004 		 * message, but otherwise is the same as an IPMB
2005 		 * address.
2006 		 */
2007 		addr->addr_type = IPMI_IPMB_ADDR_TYPE;
2008 		broadcast = 1;
2009 		retries = 0; /* Don't retry broadcasts. */
2010 	}
2011 
2012 	/*
2013 	 * 9 for the header and 1 for the checksum, plus
2014 	 * possibly one for the broadcast.
2015 	 */
2016 	if ((msg->data_len + 10 + broadcast) > IPMI_MAX_MSG_LENGTH) {
2017 		ipmi_inc_stat(intf, sent_invalid_commands);
2018 		return -EMSGSIZE;
2019 	}
2020 
2021 	ipmb_addr = (struct ipmi_ipmb_addr *) addr;
2022 	if (ipmb_addr->lun > 3) {
2023 		ipmi_inc_stat(intf, sent_invalid_commands);
2024 		return -EINVAL;
2025 	}
2026 
2027 	memcpy(&recv_msg->addr, ipmb_addr, sizeof(*ipmb_addr));
2028 
2029 	if (recv_msg->msg.netfn & 0x1) {
2030 		/*
2031 		 * It's a response, so use the user's sequence
2032 		 * from msgid.
2033 		 */
2034 		ipmi_inc_stat(intf, sent_ipmb_responses);
2035 		format_ipmb_msg(smi_msg, msg, ipmb_addr, msgid,
2036 				msgid, broadcast,
2037 				source_address, source_lun);
2038 
2039 		/*
2040 		 * Save the receive message so we can use it
2041 		 * to deliver the response.
2042 		 */
2043 		smi_msg->recv_msg = recv_msg;
2044 	} else {
2045 		mutex_lock(&intf->seq_lock);
2046 
2047 		if (is_maintenance_mode_cmd(msg))
2048 			intf->ipmb_maintenance_mode_timeout =
2049 				maintenance_mode_timeout_ms;
2050 
2051 		if (intf->ipmb_maintenance_mode_timeout && retry_time_ms == 0)
2052 			/* Different default in maintenance mode */
2053 			retry_time_ms = default_maintenance_retry_ms;
2054 
2055 		/*
2056 		 * Create a sequence number with a 1 second
2057 		 * timeout and 4 retries.
2058 		 */
2059 		rv = intf_next_seq(intf,
2060 				   recv_msg,
2061 				   retry_time_ms,
2062 				   retries,
2063 				   broadcast,
2064 				   &ipmb_seq,
2065 				   &seqid);
2066 		if (rv)
2067 			/*
2068 			 * We have used up all the sequence numbers,
2069 			 * probably, so abort.
2070 			 */
2071 			goto out_err;
2072 
2073 		ipmi_inc_stat(intf, sent_ipmb_commands);
2074 
2075 		/*
2076 		 * Store the sequence number in the message,
2077 		 * so that when the send message response
2078 		 * comes back we can start the timer.
2079 		 */
2080 		format_ipmb_msg(smi_msg, msg, ipmb_addr,
2081 				STORE_SEQ_IN_MSGID(ipmb_seq, seqid),
2082 				ipmb_seq, broadcast,
2083 				source_address, source_lun);
2084 
2085 		/*
2086 		 * Copy the message into the recv message data, so we
2087 		 * can retransmit it later if necessary.
2088 		 */
2089 		memcpy(recv_msg->msg_data, smi_msg->data,
2090 		       smi_msg->data_size);
2091 		recv_msg->msg.data = recv_msg->msg_data;
2092 		recv_msg->msg.data_len = smi_msg->data_size;
2093 
2094 		/*
2095 		 * We don't unlock until here, because we need
2096 		 * to copy the completed message into the
2097 		 * recv_msg before we release the lock.
2098 		 * Otherwise, race conditions may bite us.  I
2099 		 * know that's pretty paranoid, but I prefer
2100 		 * to be correct.
2101 		 */
2102 out_err:
2103 		mutex_unlock(&intf->seq_lock);
2104 	}
2105 
2106 	return rv;
2107 }
2108 
2109 static int i_ipmi_req_ipmb_direct(struct ipmi_smi        *intf,
2110 				  struct ipmi_addr       *addr,
2111 				  long			 msgid,
2112 				  struct kernel_ipmi_msg *msg,
2113 				  struct ipmi_smi_msg    *smi_msg,
2114 				  struct ipmi_recv_msg   *recv_msg,
2115 				  unsigned char          source_lun)
2116 {
2117 	struct ipmi_ipmb_direct_addr *daddr;
2118 	bool is_cmd = !(recv_msg->msg.netfn & 0x1);
2119 
2120 	if (!(intf->handlers->flags & IPMI_SMI_CAN_HANDLE_IPMB_DIRECT))
2121 		return -EAFNOSUPPORT;
2122 
2123 	/* Responses must have a completion code. */
2124 	if (!is_cmd && msg->data_len < 1) {
2125 		ipmi_inc_stat(intf, sent_invalid_commands);
2126 		return -EINVAL;
2127 	}
2128 
2129 	if ((msg->data_len + 4) > IPMI_MAX_MSG_LENGTH) {
2130 		ipmi_inc_stat(intf, sent_invalid_commands);
2131 		return -EMSGSIZE;
2132 	}
2133 
2134 	daddr = (struct ipmi_ipmb_direct_addr *) addr;
2135 	if (daddr->rq_lun > 3 || daddr->rs_lun > 3) {
2136 		ipmi_inc_stat(intf, sent_invalid_commands);
2137 		return -EINVAL;
2138 	}
2139 
2140 	smi_msg->type = IPMI_SMI_MSG_TYPE_IPMB_DIRECT;
2141 	smi_msg->msgid = msgid;
2142 
2143 	if (is_cmd) {
2144 		smi_msg->data[0] = msg->netfn << 2 | daddr->rs_lun;
2145 		smi_msg->data[2] = recv_msg->msgid << 2 | daddr->rq_lun;
2146 	} else {
2147 		smi_msg->data[0] = msg->netfn << 2 | daddr->rq_lun;
2148 		smi_msg->data[2] = recv_msg->msgid << 2 | daddr->rs_lun;
2149 	}
2150 	smi_msg->data[1] = daddr->slave_addr;
2151 	smi_msg->data[3] = msg->cmd;
2152 
2153 	memcpy(smi_msg->data + 4, msg->data, msg->data_len);
2154 	smi_msg->data_size = msg->data_len + 4;
2155 
2156 	smi_msg->recv_msg = recv_msg;
2157 
2158 	return 0;
2159 }
2160 
2161 static int i_ipmi_req_lan(struct ipmi_smi        *intf,
2162 			  struct ipmi_addr       *addr,
2163 			  long                   msgid,
2164 			  struct kernel_ipmi_msg *msg,
2165 			  struct ipmi_smi_msg    *smi_msg,
2166 			  struct ipmi_recv_msg   *recv_msg,
2167 			  unsigned char          source_lun,
2168 			  int                    retries,
2169 			  unsigned int           retry_time_ms)
2170 {
2171 	struct ipmi_lan_addr  *lan_addr;
2172 	unsigned char ipmb_seq;
2173 	long seqid;
2174 	struct ipmi_channel *chans;
2175 	int rv = 0;
2176 
2177 	if (addr->channel >= IPMI_MAX_CHANNELS) {
2178 		ipmi_inc_stat(intf, sent_invalid_commands);
2179 		return -EINVAL;
2180 	}
2181 
2182 	chans = READ_ONCE(intf->channel_list)->c;
2183 
2184 	if ((chans[addr->channel].medium
2185 				!= IPMI_CHANNEL_MEDIUM_8023LAN)
2186 			&& (chans[addr->channel].medium
2187 			    != IPMI_CHANNEL_MEDIUM_ASYNC)) {
2188 		ipmi_inc_stat(intf, sent_invalid_commands);
2189 		return -EINVAL;
2190 	}
2191 
2192 	/* 11 for the header and 1 for the checksum. */
2193 	if ((msg->data_len + 12) > IPMI_MAX_MSG_LENGTH) {
2194 		ipmi_inc_stat(intf, sent_invalid_commands);
2195 		return -EMSGSIZE;
2196 	}
2197 
2198 	lan_addr = (struct ipmi_lan_addr *) addr;
2199 	if (lan_addr->lun > 3) {
2200 		ipmi_inc_stat(intf, sent_invalid_commands);
2201 		return -EINVAL;
2202 	}
2203 
2204 	memcpy(&recv_msg->addr, lan_addr, sizeof(*lan_addr));
2205 
2206 	if (recv_msg->msg.netfn & 0x1) {
2207 		/*
2208 		 * It's a response, so use the user's sequence
2209 		 * from msgid.
2210 		 */
2211 		ipmi_inc_stat(intf, sent_lan_responses);
2212 		format_lan_msg(smi_msg, msg, lan_addr, msgid,
2213 			       msgid, source_lun);
2214 
2215 		/*
2216 		 * Save the receive message so we can use it
2217 		 * to deliver the response.
2218 		 */
2219 		smi_msg->recv_msg = recv_msg;
2220 	} else {
2221 		mutex_lock(&intf->seq_lock);
2222 
2223 		/*
2224 		 * Create a sequence number with a 1 second
2225 		 * timeout and 4 retries.
2226 		 */
2227 		rv = intf_next_seq(intf,
2228 				   recv_msg,
2229 				   retry_time_ms,
2230 				   retries,
2231 				   0,
2232 				   &ipmb_seq,
2233 				   &seqid);
2234 		if (rv)
2235 			/*
2236 			 * We have used up all the sequence numbers,
2237 			 * probably, so abort.
2238 			 */
2239 			goto out_err;
2240 
2241 		ipmi_inc_stat(intf, sent_lan_commands);
2242 
2243 		/*
2244 		 * Store the sequence number in the message,
2245 		 * so that when the send message response
2246 		 * comes back we can start the timer.
2247 		 */
2248 		format_lan_msg(smi_msg, msg, lan_addr,
2249 			       STORE_SEQ_IN_MSGID(ipmb_seq, seqid),
2250 			       ipmb_seq, source_lun);
2251 
2252 		/*
2253 		 * Copy the message into the recv message data, so we
2254 		 * can retransmit it later if necessary.
2255 		 */
2256 		memcpy(recv_msg->msg_data, smi_msg->data,
2257 		       smi_msg->data_size);
2258 		recv_msg->msg.data = recv_msg->msg_data;
2259 		recv_msg->msg.data_len = smi_msg->data_size;
2260 
2261 		/*
2262 		 * We don't unlock until here, because we need
2263 		 * to copy the completed message into the
2264 		 * recv_msg before we release the lock.
2265 		 * Otherwise, race conditions may bite us.  I
2266 		 * know that's pretty paranoid, but I prefer
2267 		 * to be correct.
2268 		 */
2269 out_err:
2270 		mutex_unlock(&intf->seq_lock);
2271 	}
2272 
2273 	return rv;
2274 }
2275 
2276 /*
2277  * Separate from ipmi_request so that the user does not have to be
2278  * supplied in certain circumstances (mainly at panic time).  If
2279  * messages are supplied, they will be freed, even if an error
2280  * occurs.
2281  */
2282 static int i_ipmi_request(struct ipmi_user     *user,
2283 			  struct ipmi_smi      *intf,
2284 			  struct ipmi_addr     *addr,
2285 			  long                 msgid,
2286 			  struct kernel_ipmi_msg *msg,
2287 			  void                 *user_msg_data,
2288 			  void                 *supplied_smi,
2289 			  struct ipmi_recv_msg *supplied_recv,
2290 			  int                  priority,
2291 			  unsigned char        source_address,
2292 			  unsigned char        source_lun,
2293 			  int                  retries,
2294 			  unsigned int         retry_time_ms)
2295 {
2296 	struct ipmi_smi_msg *smi_msg;
2297 	struct ipmi_recv_msg *recv_msg;
2298 	int run_to_completion = READ_ONCE(intf->run_to_completion);
2299 	int rv = 0;
2300 
2301 	if (supplied_recv) {
2302 		recv_msg = supplied_recv;
2303 		recv_msg->user = user;
2304 		if (user)
2305 			atomic_inc(&user->nr_msgs);
2306 	} else {
2307 		recv_msg = ipmi_alloc_recv_msg(user);
2308 		if (IS_ERR(recv_msg))
2309 			return PTR_ERR(recv_msg);
2310 	}
2311 	recv_msg->user_msg_data = user_msg_data;
2312 
2313 	if (supplied_smi)
2314 		smi_msg = supplied_smi;
2315 	else {
2316 		smi_msg = ipmi_alloc_smi_msg();
2317 		if (smi_msg == NULL) {
2318 			if (!supplied_recv)
2319 				ipmi_free_recv_msg(recv_msg);
2320 			return -ENOMEM;
2321 		}
2322 	}
2323 
2324 	if (!run_to_completion)
2325 		mutex_lock(&intf->users_mutex);
2326 	if (intf->maintenance_mode_state == IPMI_MAINTENANCE_MODE_STATE_RESET) {
2327 		/* No messages while the BMC is in reset. */
2328 		rv = -EBUSY;
2329 		goto out_err;
2330 	}
2331 	if (intf->in_shutdown) {
2332 		rv = -ENODEV;
2333 		goto out_err;
2334 	}
2335 
2336 	recv_msg->msgid = msgid;
2337 	/*
2338 	 * Store the message to send in the receive message so timeout
2339 	 * responses can get the proper response data.
2340 	 */
2341 	recv_msg->msg = *msg;
2342 
2343 	if (addr->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
2344 		rv = i_ipmi_req_sysintf(intf, addr, msgid, msg, smi_msg,
2345 					recv_msg, retries, retry_time_ms);
2346 	} else if (is_ipmb_addr(addr) || is_ipmb_bcast_addr(addr)) {
2347 		rv = i_ipmi_req_ipmb(intf, addr, msgid, msg, smi_msg, recv_msg,
2348 				     source_address, source_lun,
2349 				     retries, retry_time_ms);
2350 	} else if (is_ipmb_direct_addr(addr)) {
2351 		rv = i_ipmi_req_ipmb_direct(intf, addr, msgid, msg, smi_msg,
2352 					    recv_msg, source_lun);
2353 	} else if (is_lan_addr(addr)) {
2354 		rv = i_ipmi_req_lan(intf, addr, msgid, msg, smi_msg, recv_msg,
2355 				    source_lun, retries, retry_time_ms);
2356 	} else {
2357 	    /* Unknown address type. */
2358 		ipmi_inc_stat(intf, sent_invalid_commands);
2359 		rv = -EINVAL;
2360 	}
2361 
2362 	if (rv) {
2363 out_err:
2364 		if (!supplied_smi)
2365 			ipmi_free_smi_msg(smi_msg);
2366 		if (!supplied_recv)
2367 			ipmi_free_recv_msg(recv_msg);
2368 	} else {
2369 		dev_dbg(intf->si_dev, "Send: %*ph\n",
2370 			smi_msg->data_size, smi_msg->data);
2371 
2372 		smi_send(intf, intf->handlers, smi_msg, priority);
2373 	}
2374 	if (!run_to_completion)
2375 		mutex_unlock(&intf->users_mutex);
2376 
2377 	return rv;
2378 }
2379 
2380 static int check_addr(struct ipmi_smi  *intf,
2381 		      struct ipmi_addr *addr,
2382 		      unsigned char    *saddr,
2383 		      unsigned char    *lun)
2384 {
2385 	if (addr->channel >= IPMI_MAX_CHANNELS)
2386 		return -EINVAL;
2387 	addr->channel = array_index_nospec(addr->channel, IPMI_MAX_CHANNELS);
2388 	*lun = intf->addrinfo[addr->channel].lun;
2389 	*saddr = intf->addrinfo[addr->channel].address;
2390 	return 0;
2391 }
2392 
2393 int ipmi_request_settime(struct ipmi_user *user,
2394 			 struct ipmi_addr *addr,
2395 			 long             msgid,
2396 			 struct kernel_ipmi_msg  *msg,
2397 			 void             *user_msg_data,
2398 			 int              priority,
2399 			 int              retries,
2400 			 unsigned int     retry_time_ms)
2401 {
2402 	unsigned char saddr = 0, lun = 0;
2403 	int rv;
2404 
2405 	if (!user)
2406 		return -EINVAL;
2407 
2408 	user = acquire_ipmi_user(user);
2409 	if (!user)
2410 		return -ENODEV;
2411 
2412 	rv = check_addr(user->intf, addr, &saddr, &lun);
2413 	if (!rv)
2414 		rv = i_ipmi_request(user,
2415 				    user->intf,
2416 				    addr,
2417 				    msgid,
2418 				    msg,
2419 				    user_msg_data,
2420 				    NULL, NULL,
2421 				    priority,
2422 				    saddr,
2423 				    lun,
2424 				    retries,
2425 				    retry_time_ms);
2426 
2427 	release_ipmi_user(user);
2428 	return rv;
2429 }
2430 EXPORT_SYMBOL(ipmi_request_settime);
2431 
2432 int ipmi_request_supply_msgs(struct ipmi_user     *user,
2433 			     struct ipmi_addr     *addr,
2434 			     long                 msgid,
2435 			     struct kernel_ipmi_msg *msg,
2436 			     void                 *user_msg_data,
2437 			     void                 *supplied_smi,
2438 			     struct ipmi_recv_msg *supplied_recv,
2439 			     int                  priority)
2440 {
2441 	unsigned char saddr = 0, lun = 0;
2442 	int rv;
2443 
2444 	if (!user)
2445 		return -EINVAL;
2446 
2447 	user = acquire_ipmi_user(user);
2448 	if (!user)
2449 		return -ENODEV;
2450 
2451 	rv = check_addr(user->intf, addr, &saddr, &lun);
2452 	if (!rv)
2453 		rv = i_ipmi_request(user,
2454 				    user->intf,
2455 				    addr,
2456 				    msgid,
2457 				    msg,
2458 				    user_msg_data,
2459 				    supplied_smi,
2460 				    supplied_recv,
2461 				    priority,
2462 				    saddr,
2463 				    lun,
2464 				    -1, 0);
2465 
2466 	release_ipmi_user(user);
2467 	return rv;
2468 }
2469 EXPORT_SYMBOL(ipmi_request_supply_msgs);
2470 
2471 static void bmc_device_id_handler(struct ipmi_smi *intf,
2472 				  struct ipmi_recv_msg *msg)
2473 {
2474 	int rv;
2475 
2476 	if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
2477 			|| (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE)
2478 			|| (msg->msg.cmd != IPMI_GET_DEVICE_ID_CMD)) {
2479 		dev_warn(intf->si_dev,
2480 			 "invalid device_id msg: addr_type=%d netfn=%x cmd=%x\n",
2481 			 msg->addr.addr_type, msg->msg.netfn, msg->msg.cmd);
2482 		return;
2483 	}
2484 
2485 	if (msg->msg.data[0]) {
2486 		dev_warn(intf->si_dev, "device id fetch failed: 0x%2.2x\n",
2487 			 msg->msg.data[0]);
2488 		intf->bmc->dyn_id_set = 0;
2489 		goto out;
2490 	}
2491 
2492 	rv = ipmi_demangle_device_id(msg->msg.netfn, msg->msg.cmd,
2493 			msg->msg.data, msg->msg.data_len, &intf->bmc->fetch_id);
2494 	if (rv) {
2495 		dev_warn(intf->si_dev, "device id demangle failed: %d\n", rv);
2496 		/* record completion code when error */
2497 		intf->bmc->cc = msg->msg.data[0];
2498 		intf->bmc->dyn_id_set = 0;
2499 	} else {
2500 		/*
2501 		 * Make sure the id data is available before setting
2502 		 * dyn_id_set.
2503 		 */
2504 		smp_wmb();
2505 		intf->bmc->dyn_id_set = 1;
2506 	}
2507 out:
2508 	wake_up(&intf->waitq);
2509 }
2510 
2511 static int
2512 send_get_device_id_cmd(struct ipmi_smi *intf)
2513 {
2514 	struct ipmi_system_interface_addr si;
2515 	struct kernel_ipmi_msg msg;
2516 
2517 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
2518 	si.channel = IPMI_BMC_CHANNEL;
2519 	si.lun = 0;
2520 
2521 	msg.netfn = IPMI_NETFN_APP_REQUEST;
2522 	msg.cmd = IPMI_GET_DEVICE_ID_CMD;
2523 	msg.data = NULL;
2524 	msg.data_len = 0;
2525 
2526 	return i_ipmi_request(NULL,
2527 			      intf,
2528 			      (struct ipmi_addr *) &si,
2529 			      0,
2530 			      &msg,
2531 			      intf,
2532 			      NULL,
2533 			      NULL,
2534 			      0,
2535 			      intf->addrinfo[0].address,
2536 			      intf->addrinfo[0].lun,
2537 			      -1, 0);
2538 }
2539 
2540 static int __get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc)
2541 {
2542 	int rv;
2543 	unsigned int retry_count = 0;
2544 
2545 	intf->null_user_handler = bmc_device_id_handler;
2546 
2547 retry:
2548 	bmc->cc = 0;
2549 	bmc->dyn_id_set = 2;
2550 
2551 	rv = send_get_device_id_cmd(intf);
2552 	if (rv)
2553 		goto out_reset_handler;
2554 
2555 	wait_event(intf->waitq, bmc->dyn_id_set != 2);
2556 
2557 	if (!bmc->dyn_id_set) {
2558 		if (bmc->cc != IPMI_CC_NO_ERROR &&
2559 		    ++retry_count <= GET_DEVICE_ID_MAX_RETRY) {
2560 			msleep(500);
2561 			dev_warn(intf->si_dev,
2562 			    "BMC returned 0x%2.2x, retry get bmc device id\n",
2563 			    bmc->cc);
2564 			goto retry;
2565 		}
2566 
2567 		rv = -EIO; /* Something went wrong in the fetch. */
2568 	}
2569 
2570 	/* dyn_id_set makes the id data available. */
2571 	smp_rmb();
2572 
2573 out_reset_handler:
2574 	intf->null_user_handler = NULL;
2575 
2576 	return rv;
2577 }
2578 
2579 /*
2580  * Fetch the device id for the bmc/interface.  You must pass in either
2581  * bmc or intf, this code will get the other one.  If the data has
2582  * been recently fetched, this will just use the cached data.  Otherwise
2583  * it will run a new fetch.
2584  *
2585  * Except for the first time this is called (in ipmi_add_smi()),
2586  * this will always return good data;
2587  */
2588 static int __bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
2589 			       struct ipmi_device_id *id,
2590 			       bool *guid_set, guid_t *guid, int intf_num)
2591 {
2592 	int rv = 0;
2593 	int prev_dyn_id_set, prev_guid_set;
2594 	bool intf_set = intf != NULL;
2595 
2596 	if (!intf) {
2597 		mutex_lock(&bmc->dyn_mutex);
2598 retry_bmc_lock:
2599 		if (list_empty(&bmc->intfs)) {
2600 			mutex_unlock(&bmc->dyn_mutex);
2601 			return -ENOENT;
2602 		}
2603 		intf = list_first_entry(&bmc->intfs, struct ipmi_smi,
2604 					bmc_link);
2605 		kref_get(&intf->refcount);
2606 		mutex_unlock(&bmc->dyn_mutex);
2607 		mutex_lock(&intf->bmc_reg_mutex);
2608 		mutex_lock(&bmc->dyn_mutex);
2609 		if (intf != list_first_entry(&bmc->intfs, struct ipmi_smi,
2610 					     bmc_link)) {
2611 			mutex_unlock(&intf->bmc_reg_mutex);
2612 			kref_put(&intf->refcount, intf_free);
2613 			goto retry_bmc_lock;
2614 		}
2615 	} else {
2616 		mutex_lock(&intf->bmc_reg_mutex);
2617 		bmc = intf->bmc;
2618 		mutex_lock(&bmc->dyn_mutex);
2619 		kref_get(&intf->refcount);
2620 	}
2621 
2622 	/* If we have a valid and current ID, just return that. */
2623 	if (intf->in_bmc_register ||
2624 	    (bmc->dyn_id_set && time_is_after_jiffies(bmc->dyn_id_expiry)))
2625 		goto out_noprocessing;
2626 
2627 	/* Don't allow sysfs access when in maintenance mode. */
2628 	if (intf->maintenance_mode_state) {
2629 		rv = -EBUSY;
2630 		goto out_noprocessing;
2631 	}
2632 
2633 	prev_guid_set = bmc->dyn_guid_set;
2634 	__get_guid(intf);
2635 
2636 	prev_dyn_id_set = bmc->dyn_id_set;
2637 	rv = __get_device_id(intf, bmc);
2638 	if (rv)
2639 		goto out;
2640 
2641 	/*
2642 	 * The guid, device id, manufacturer id, and product id should
2643 	 * not change on a BMC.  If it does we have to do some dancing.
2644 	 */
2645 	if (!intf->bmc_registered
2646 	    || (!prev_guid_set && bmc->dyn_guid_set)
2647 	    || (!prev_dyn_id_set && bmc->dyn_id_set)
2648 	    || (prev_guid_set && bmc->dyn_guid_set
2649 		&& !guid_equal(&bmc->guid, &bmc->fetch_guid))
2650 	    || bmc->id.device_id != bmc->fetch_id.device_id
2651 	    || bmc->id.manufacturer_id != bmc->fetch_id.manufacturer_id
2652 	    || bmc->id.product_id != bmc->fetch_id.product_id) {
2653 		struct ipmi_device_id id = bmc->fetch_id;
2654 		int guid_set = bmc->dyn_guid_set;
2655 		guid_t guid;
2656 
2657 		guid = bmc->fetch_guid;
2658 		mutex_unlock(&bmc->dyn_mutex);
2659 
2660 		__ipmi_bmc_unregister(intf);
2661 		/* Fill in the temporary BMC for good measure. */
2662 		intf->bmc->id = id;
2663 		intf->bmc->dyn_guid_set = guid_set;
2664 		intf->bmc->guid = guid;
2665 		if (__ipmi_bmc_register(intf, &id, guid_set, &guid, intf_num))
2666 			need_waiter(intf); /* Retry later on an error. */
2667 		else
2668 			__scan_channels(intf, &id);
2669 
2670 
2671 		if (!intf_set) {
2672 			/*
2673 			 * We weren't given the interface on the
2674 			 * command line, so restart the operation on
2675 			 * the next interface for the BMC.
2676 			 */
2677 			mutex_unlock(&intf->bmc_reg_mutex);
2678 			mutex_lock(&bmc->dyn_mutex);
2679 			goto retry_bmc_lock;
2680 		}
2681 
2682 		/* We have a new BMC, set it up. */
2683 		bmc = intf->bmc;
2684 		mutex_lock(&bmc->dyn_mutex);
2685 		goto out_noprocessing;
2686 	} else if (memcmp(&bmc->fetch_id, &bmc->id, sizeof(bmc->id)))
2687 		/* Version info changes, scan the channels again. */
2688 		__scan_channels(intf, &bmc->fetch_id);
2689 
2690 	bmc->dyn_id_expiry = jiffies + IPMI_DYN_DEV_ID_EXPIRY;
2691 
2692 out:
2693 	if (rv && prev_dyn_id_set) {
2694 		rv = 0; /* Ignore failures if we have previous data. */
2695 		bmc->dyn_id_set = prev_dyn_id_set;
2696 	}
2697 	if (!rv) {
2698 		bmc->id = bmc->fetch_id;
2699 		if (bmc->dyn_guid_set)
2700 			bmc->guid = bmc->fetch_guid;
2701 		else if (prev_guid_set)
2702 			/*
2703 			 * The guid used to be valid and it failed to fetch,
2704 			 * just use the cached value.
2705 			 */
2706 			bmc->dyn_guid_set = prev_guid_set;
2707 	}
2708 out_noprocessing:
2709 	if (!rv) {
2710 		if (id)
2711 			*id = bmc->id;
2712 
2713 		if (guid_set)
2714 			*guid_set = bmc->dyn_guid_set;
2715 
2716 		if (guid && bmc->dyn_guid_set)
2717 			*guid =  bmc->guid;
2718 	}
2719 
2720 	mutex_unlock(&bmc->dyn_mutex);
2721 	mutex_unlock(&intf->bmc_reg_mutex);
2722 
2723 	kref_put(&intf->refcount, intf_free);
2724 	return rv;
2725 }
2726 
2727 static int bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
2728 			     struct ipmi_device_id *id,
2729 			     bool *guid_set, guid_t *guid)
2730 {
2731 	return __bmc_get_device_id(intf, bmc, id, guid_set, guid, -1);
2732 }
2733 
2734 static ssize_t device_id_show(struct device *dev,
2735 			      struct device_attribute *attr,
2736 			      char *buf)
2737 {
2738 	struct bmc_device *bmc = to_bmc_device(dev);
2739 	struct ipmi_device_id id;
2740 	int rv;
2741 
2742 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2743 	if (rv)
2744 		return rv;
2745 
2746 	return sysfs_emit(buf, "%u\n", id.device_id);
2747 }
2748 static DEVICE_ATTR_RO(device_id);
2749 
2750 static ssize_t provides_device_sdrs_show(struct device *dev,
2751 					 struct device_attribute *attr,
2752 					 char *buf)
2753 {
2754 	struct bmc_device *bmc = to_bmc_device(dev);
2755 	struct ipmi_device_id id;
2756 	int rv;
2757 
2758 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2759 	if (rv)
2760 		return rv;
2761 
2762 	return sysfs_emit(buf, "%u\n", (id.device_revision & 0x80) >> 7);
2763 }
2764 static DEVICE_ATTR_RO(provides_device_sdrs);
2765 
2766 static ssize_t revision_show(struct device *dev, struct device_attribute *attr,
2767 			     char *buf)
2768 {
2769 	struct bmc_device *bmc = to_bmc_device(dev);
2770 	struct ipmi_device_id id;
2771 	int rv;
2772 
2773 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2774 	if (rv)
2775 		return rv;
2776 
2777 	return sysfs_emit(buf, "%u\n", id.device_revision & 0x0F);
2778 }
2779 static DEVICE_ATTR_RO(revision);
2780 
2781 static ssize_t firmware_revision_show(struct device *dev,
2782 				      struct device_attribute *attr,
2783 				      char *buf)
2784 {
2785 	struct bmc_device *bmc = to_bmc_device(dev);
2786 	struct ipmi_device_id id;
2787 	int rv;
2788 
2789 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2790 	if (rv)
2791 		return rv;
2792 
2793 	return sysfs_emit(buf, "%u.%x\n", id.firmware_revision_1,
2794 			id.firmware_revision_2);
2795 }
2796 static DEVICE_ATTR_RO(firmware_revision);
2797 
2798 static ssize_t ipmi_version_show(struct device *dev,
2799 				 struct device_attribute *attr,
2800 				 char *buf)
2801 {
2802 	struct bmc_device *bmc = to_bmc_device(dev);
2803 	struct ipmi_device_id id;
2804 	int rv;
2805 
2806 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2807 	if (rv)
2808 		return rv;
2809 
2810 	return sysfs_emit(buf, "%u.%u\n",
2811 			ipmi_version_major(&id),
2812 			ipmi_version_minor(&id));
2813 }
2814 static DEVICE_ATTR_RO(ipmi_version);
2815 
2816 static ssize_t add_dev_support_show(struct device *dev,
2817 				    struct device_attribute *attr,
2818 				    char *buf)
2819 {
2820 	struct bmc_device *bmc = to_bmc_device(dev);
2821 	struct ipmi_device_id id;
2822 	int rv;
2823 
2824 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2825 	if (rv)
2826 		return rv;
2827 
2828 	return sysfs_emit(buf, "0x%02x\n", id.additional_device_support);
2829 }
2830 static DEVICE_ATTR(additional_device_support, S_IRUGO, add_dev_support_show,
2831 		   NULL);
2832 
2833 static ssize_t manufacturer_id_show(struct device *dev,
2834 				    struct device_attribute *attr,
2835 				    char *buf)
2836 {
2837 	struct bmc_device *bmc = to_bmc_device(dev);
2838 	struct ipmi_device_id id;
2839 	int rv;
2840 
2841 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2842 	if (rv)
2843 		return rv;
2844 
2845 	return sysfs_emit(buf, "0x%6.6x\n", id.manufacturer_id);
2846 }
2847 static DEVICE_ATTR_RO(manufacturer_id);
2848 
2849 static ssize_t product_id_show(struct device *dev,
2850 			       struct device_attribute *attr,
2851 			       char *buf)
2852 {
2853 	struct bmc_device *bmc = to_bmc_device(dev);
2854 	struct ipmi_device_id id;
2855 	int rv;
2856 
2857 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2858 	if (rv)
2859 		return rv;
2860 
2861 	return sysfs_emit(buf, "0x%4.4x\n", id.product_id);
2862 }
2863 static DEVICE_ATTR_RO(product_id);
2864 
2865 static ssize_t aux_firmware_rev_show(struct device *dev,
2866 				     struct device_attribute *attr,
2867 				     char *buf)
2868 {
2869 	struct bmc_device *bmc = to_bmc_device(dev);
2870 	struct ipmi_device_id id;
2871 	int rv;
2872 
2873 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2874 	if (rv)
2875 		return rv;
2876 
2877 	return sysfs_emit(buf, "0x%02x 0x%02x 0x%02x 0x%02x\n",
2878 			id.aux_firmware_revision[3],
2879 			id.aux_firmware_revision[2],
2880 			id.aux_firmware_revision[1],
2881 			id.aux_firmware_revision[0]);
2882 }
2883 static DEVICE_ATTR(aux_firmware_revision, S_IRUGO, aux_firmware_rev_show, NULL);
2884 
2885 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
2886 			 char *buf)
2887 {
2888 	struct bmc_device *bmc = to_bmc_device(dev);
2889 	bool guid_set;
2890 	guid_t guid;
2891 	int rv;
2892 
2893 	rv = bmc_get_device_id(NULL, bmc, NULL, &guid_set, &guid);
2894 	if (rv)
2895 		return rv;
2896 	if (!guid_set)
2897 		return -ENOENT;
2898 
2899 	return sysfs_emit(buf, "%pUl\n", &guid);
2900 }
2901 static DEVICE_ATTR_RO(guid);
2902 
2903 static struct attribute *bmc_dev_attrs[] = {
2904 	&dev_attr_device_id.attr,
2905 	&dev_attr_provides_device_sdrs.attr,
2906 	&dev_attr_revision.attr,
2907 	&dev_attr_firmware_revision.attr,
2908 	&dev_attr_ipmi_version.attr,
2909 	&dev_attr_additional_device_support.attr,
2910 	&dev_attr_manufacturer_id.attr,
2911 	&dev_attr_product_id.attr,
2912 	&dev_attr_aux_firmware_revision.attr,
2913 	&dev_attr_guid.attr,
2914 	NULL
2915 };
2916 
2917 static umode_t bmc_dev_attr_is_visible(struct kobject *kobj,
2918 				       struct attribute *attr, int idx)
2919 {
2920 	struct device *dev = kobj_to_dev(kobj);
2921 	struct bmc_device *bmc = to_bmc_device(dev);
2922 	umode_t mode = attr->mode;
2923 	int rv;
2924 
2925 	if (attr == &dev_attr_aux_firmware_revision.attr) {
2926 		struct ipmi_device_id id;
2927 
2928 		rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2929 		return (!rv && id.aux_firmware_revision_set) ? mode : 0;
2930 	}
2931 	if (attr == &dev_attr_guid.attr) {
2932 		bool guid_set;
2933 
2934 		rv = bmc_get_device_id(NULL, bmc, NULL, &guid_set, NULL);
2935 		return (!rv && guid_set) ? mode : 0;
2936 	}
2937 	return mode;
2938 }
2939 
2940 static const struct attribute_group bmc_dev_attr_group = {
2941 	.attrs		= bmc_dev_attrs,
2942 	.is_visible	= bmc_dev_attr_is_visible,
2943 };
2944 
2945 static const struct attribute_group *bmc_dev_attr_groups[] = {
2946 	&bmc_dev_attr_group,
2947 	NULL
2948 };
2949 
2950 static const struct device_type bmc_device_type = {
2951 	.groups		= bmc_dev_attr_groups,
2952 };
2953 
2954 static int __find_bmc_guid(struct device *dev, const void *data)
2955 {
2956 	const guid_t *guid = data;
2957 	struct bmc_device *bmc;
2958 	int rv;
2959 
2960 	if (dev->type != &bmc_device_type)
2961 		return 0;
2962 
2963 	bmc = to_bmc_device(dev);
2964 	rv = bmc->dyn_guid_set && guid_equal(&bmc->guid, guid);
2965 	if (rv)
2966 		rv = kref_get_unless_zero(&bmc->usecount);
2967 	return rv;
2968 }
2969 
2970 /*
2971  * Returns with the bmc's usecount incremented, if it is non-NULL.
2972  */
2973 static struct bmc_device *ipmi_find_bmc_guid(struct device_driver *drv,
2974 					     guid_t *guid)
2975 {
2976 	struct device *dev;
2977 	struct bmc_device *bmc = NULL;
2978 
2979 	dev = driver_find_device(drv, NULL, guid, __find_bmc_guid);
2980 	if (dev) {
2981 		bmc = to_bmc_device(dev);
2982 		put_device(dev);
2983 	}
2984 	return bmc;
2985 }
2986 
2987 struct prod_dev_id {
2988 	unsigned int  product_id;
2989 	unsigned char device_id;
2990 };
2991 
2992 static int __find_bmc_prod_dev_id(struct device *dev, const void *data)
2993 {
2994 	const struct prod_dev_id *cid = data;
2995 	struct bmc_device *bmc;
2996 	int rv;
2997 
2998 	if (dev->type != &bmc_device_type)
2999 		return 0;
3000 
3001 	bmc = to_bmc_device(dev);
3002 	rv = (bmc->id.product_id == cid->product_id
3003 	      && bmc->id.device_id == cid->device_id);
3004 	if (rv)
3005 		rv = kref_get_unless_zero(&bmc->usecount);
3006 	return rv;
3007 }
3008 
3009 /*
3010  * Returns with the bmc's usecount incremented, if it is non-NULL.
3011  */
3012 static struct bmc_device *ipmi_find_bmc_prod_dev_id(
3013 	struct device_driver *drv,
3014 	unsigned int product_id, unsigned char device_id)
3015 {
3016 	struct prod_dev_id id = {
3017 		.product_id = product_id,
3018 		.device_id = device_id,
3019 	};
3020 	struct device *dev;
3021 	struct bmc_device *bmc = NULL;
3022 
3023 	dev = driver_find_device(drv, NULL, &id, __find_bmc_prod_dev_id);
3024 	if (dev) {
3025 		bmc = to_bmc_device(dev);
3026 		put_device(dev);
3027 	}
3028 	return bmc;
3029 }
3030 
3031 static DEFINE_IDA(ipmi_bmc_ida);
3032 
3033 static void
3034 release_bmc_device(struct device *dev)
3035 {
3036 	kfree(to_bmc_device(dev));
3037 }
3038 
3039 static void cleanup_bmc_work(struct work_struct *work)
3040 {
3041 	struct bmc_device *bmc = container_of(work, struct bmc_device,
3042 					      remove_work);
3043 	int id = bmc->pdev.id; /* Unregister overwrites id */
3044 
3045 	platform_device_unregister(&bmc->pdev);
3046 	ida_free(&ipmi_bmc_ida, id);
3047 }
3048 
3049 static void
3050 cleanup_bmc_device(struct kref *ref)
3051 {
3052 	struct bmc_device *bmc = container_of(ref, struct bmc_device, usecount);
3053 
3054 	/*
3055 	 * Remove the platform device in a work queue to avoid issues
3056 	 * with removing the device attributes while reading a device
3057 	 * attribute.
3058 	 */
3059 	queue_work(bmc_remove_work_wq, &bmc->remove_work);
3060 }
3061 
3062 /*
3063  * Must be called with intf->bmc_reg_mutex held.
3064  */
3065 static void __ipmi_bmc_unregister(struct ipmi_smi *intf)
3066 {
3067 	struct bmc_device *bmc = intf->bmc;
3068 
3069 	if (!intf->bmc_registered)
3070 		return;
3071 
3072 	sysfs_remove_link(&intf->si_dev->kobj, "bmc");
3073 	sysfs_remove_link(&bmc->pdev.dev.kobj, intf->my_dev_name);
3074 	kfree(intf->my_dev_name);
3075 	intf->my_dev_name = NULL;
3076 
3077 	mutex_lock(&bmc->dyn_mutex);
3078 	list_del(&intf->bmc_link);
3079 	mutex_unlock(&bmc->dyn_mutex);
3080 	intf->bmc = &intf->tmp_bmc;
3081 	kref_put(&bmc->usecount, cleanup_bmc_device);
3082 	intf->bmc_registered = false;
3083 }
3084 
3085 static void ipmi_bmc_unregister(struct ipmi_smi *intf)
3086 {
3087 	mutex_lock(&intf->bmc_reg_mutex);
3088 	__ipmi_bmc_unregister(intf);
3089 	mutex_unlock(&intf->bmc_reg_mutex);
3090 }
3091 
3092 /*
3093  * Must be called with intf->bmc_reg_mutex held.
3094  */
3095 static int __ipmi_bmc_register(struct ipmi_smi *intf,
3096 			       struct ipmi_device_id *id,
3097 			       bool guid_set, guid_t *guid, int intf_num)
3098 {
3099 	int               rv;
3100 	struct bmc_device *bmc;
3101 	struct bmc_device *old_bmc;
3102 
3103 	/*
3104 	 * platform_device_register() can cause bmc_reg_mutex to
3105 	 * be claimed because of the is_visible functions of
3106 	 * the attributes.  Eliminate possible recursion and
3107 	 * release the lock.
3108 	 */
3109 	intf->in_bmc_register = true;
3110 	mutex_unlock(&intf->bmc_reg_mutex);
3111 
3112 	/*
3113 	 * Try to find if there is an bmc_device struct
3114 	 * representing the interfaced BMC already
3115 	 */
3116 	mutex_lock(&ipmidriver_mutex);
3117 	if (guid_set)
3118 		old_bmc = ipmi_find_bmc_guid(&ipmidriver.driver, guid);
3119 	else
3120 		old_bmc = ipmi_find_bmc_prod_dev_id(&ipmidriver.driver,
3121 						    id->product_id,
3122 						    id->device_id);
3123 
3124 	/*
3125 	 * If there is already an bmc_device, free the new one,
3126 	 * otherwise register the new BMC device
3127 	 */
3128 	if (old_bmc) {
3129 		bmc = old_bmc;
3130 		/*
3131 		 * Note: old_bmc already has usecount incremented by
3132 		 * the BMC find functions.
3133 		 */
3134 		intf->bmc = old_bmc;
3135 		mutex_lock(&bmc->dyn_mutex);
3136 		list_add_tail(&intf->bmc_link, &bmc->intfs);
3137 		mutex_unlock(&bmc->dyn_mutex);
3138 
3139 		dev_info(intf->si_dev,
3140 			 "interfacing existing BMC (man_id: 0x%6.6x, prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n",
3141 			 bmc->id.manufacturer_id,
3142 			 bmc->id.product_id,
3143 			 bmc->id.device_id);
3144 	} else {
3145 		bmc = kzalloc(sizeof(*bmc), GFP_KERNEL);
3146 		if (!bmc) {
3147 			rv = -ENOMEM;
3148 			goto out;
3149 		}
3150 		INIT_LIST_HEAD(&bmc->intfs);
3151 		mutex_init(&bmc->dyn_mutex);
3152 		INIT_WORK(&bmc->remove_work, cleanup_bmc_work);
3153 
3154 		bmc->id = *id;
3155 		bmc->dyn_id_set = 1;
3156 		bmc->dyn_guid_set = guid_set;
3157 		bmc->guid = *guid;
3158 		bmc->dyn_id_expiry = jiffies + IPMI_DYN_DEV_ID_EXPIRY;
3159 
3160 		bmc->pdev.name = "ipmi_bmc";
3161 
3162 		rv = ida_alloc(&ipmi_bmc_ida, GFP_KERNEL);
3163 		if (rv < 0) {
3164 			kfree(bmc);
3165 			goto out;
3166 		}
3167 
3168 		bmc->pdev.dev.driver = &ipmidriver.driver;
3169 		bmc->pdev.id = rv;
3170 		bmc->pdev.dev.release = release_bmc_device;
3171 		bmc->pdev.dev.type = &bmc_device_type;
3172 		kref_init(&bmc->usecount);
3173 
3174 		intf->bmc = bmc;
3175 		mutex_lock(&bmc->dyn_mutex);
3176 		list_add_tail(&intf->bmc_link, &bmc->intfs);
3177 		mutex_unlock(&bmc->dyn_mutex);
3178 
3179 		rv = platform_device_register(&bmc->pdev);
3180 		if (rv) {
3181 			dev_err(intf->si_dev,
3182 				"Unable to register bmc device: %d\n",
3183 				rv);
3184 			goto out_list_del;
3185 		}
3186 
3187 		dev_info(intf->si_dev,
3188 			 "Found new BMC (man_id: 0x%6.6x, prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n",
3189 			 bmc->id.manufacturer_id,
3190 			 bmc->id.product_id,
3191 			 bmc->id.device_id);
3192 	}
3193 
3194 	/*
3195 	 * create symlink from system interface device to bmc device
3196 	 * and back.
3197 	 */
3198 	rv = sysfs_create_link(&intf->si_dev->kobj, &bmc->pdev.dev.kobj, "bmc");
3199 	if (rv) {
3200 		dev_err(intf->si_dev, "Unable to create bmc symlink: %d\n", rv);
3201 		goto out_put_bmc;
3202 	}
3203 
3204 	if (intf_num == -1)
3205 		intf_num = intf->intf_num;
3206 	intf->my_dev_name = kasprintf(GFP_KERNEL, "ipmi%d", intf_num);
3207 	if (!intf->my_dev_name) {
3208 		rv = -ENOMEM;
3209 		dev_err(intf->si_dev, "Unable to allocate link from BMC: %d\n",
3210 			rv);
3211 		goto out_unlink1;
3212 	}
3213 
3214 	rv = sysfs_create_link(&bmc->pdev.dev.kobj, &intf->si_dev->kobj,
3215 			       intf->my_dev_name);
3216 	if (rv) {
3217 		dev_err(intf->si_dev, "Unable to create symlink to bmc: %d\n",
3218 			rv);
3219 		goto out_free_my_dev_name;
3220 	}
3221 
3222 	intf->bmc_registered = true;
3223 
3224 out:
3225 	mutex_unlock(&ipmidriver_mutex);
3226 	mutex_lock(&intf->bmc_reg_mutex);
3227 	intf->in_bmc_register = false;
3228 	return rv;
3229 
3230 
3231 out_free_my_dev_name:
3232 	kfree(intf->my_dev_name);
3233 	intf->my_dev_name = NULL;
3234 
3235 out_unlink1:
3236 	sysfs_remove_link(&intf->si_dev->kobj, "bmc");
3237 
3238 out_put_bmc:
3239 	mutex_lock(&bmc->dyn_mutex);
3240 	list_del(&intf->bmc_link);
3241 	mutex_unlock(&bmc->dyn_mutex);
3242 	intf->bmc = &intf->tmp_bmc;
3243 	kref_put(&bmc->usecount, cleanup_bmc_device);
3244 	goto out;
3245 
3246 out_list_del:
3247 	mutex_lock(&bmc->dyn_mutex);
3248 	list_del(&intf->bmc_link);
3249 	mutex_unlock(&bmc->dyn_mutex);
3250 	intf->bmc = &intf->tmp_bmc;
3251 	put_device(&bmc->pdev.dev);
3252 	goto out;
3253 }
3254 
3255 static int
3256 send_guid_cmd(struct ipmi_smi *intf, int chan)
3257 {
3258 	struct kernel_ipmi_msg            msg;
3259 	struct ipmi_system_interface_addr si;
3260 
3261 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
3262 	si.channel = IPMI_BMC_CHANNEL;
3263 	si.lun = 0;
3264 
3265 	msg.netfn = IPMI_NETFN_APP_REQUEST;
3266 	msg.cmd = IPMI_GET_DEVICE_GUID_CMD;
3267 	msg.data = NULL;
3268 	msg.data_len = 0;
3269 	return i_ipmi_request(NULL,
3270 			      intf,
3271 			      (struct ipmi_addr *) &si,
3272 			      0,
3273 			      &msg,
3274 			      intf,
3275 			      NULL,
3276 			      NULL,
3277 			      0,
3278 			      intf->addrinfo[0].address,
3279 			      intf->addrinfo[0].lun,
3280 			      -1, 0);
3281 }
3282 
3283 static void guid_handler(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
3284 {
3285 	struct bmc_device *bmc = intf->bmc;
3286 
3287 	if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
3288 	    || (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE)
3289 	    || (msg->msg.cmd != IPMI_GET_DEVICE_GUID_CMD))
3290 		/* Not for me */
3291 		return;
3292 
3293 	if (msg->msg.data[0] != 0) {
3294 		/* Error from getting the GUID, the BMC doesn't have one. */
3295 		bmc->dyn_guid_set = 0;
3296 		goto out;
3297 	}
3298 
3299 	if (msg->msg.data_len < UUID_SIZE + 1) {
3300 		bmc->dyn_guid_set = 0;
3301 		dev_warn(intf->si_dev,
3302 			 "The GUID response from the BMC was too short, it was %d but should have been %d.  Assuming GUID is not available.\n",
3303 			 msg->msg.data_len, UUID_SIZE + 1);
3304 		goto out;
3305 	}
3306 
3307 	import_guid(&bmc->fetch_guid, msg->msg.data + 1);
3308 	/*
3309 	 * Make sure the guid data is available before setting
3310 	 * dyn_guid_set.
3311 	 */
3312 	smp_wmb();
3313 	bmc->dyn_guid_set = 1;
3314  out:
3315 	wake_up(&intf->waitq);
3316 }
3317 
3318 static void __get_guid(struct ipmi_smi *intf)
3319 {
3320 	int rv;
3321 	struct bmc_device *bmc = intf->bmc;
3322 
3323 	bmc->dyn_guid_set = 2;
3324 	intf->null_user_handler = guid_handler;
3325 	rv = send_guid_cmd(intf, 0);
3326 	if (rv)
3327 		/* Send failed, no GUID available. */
3328 		bmc->dyn_guid_set = 0;
3329 	else
3330 		wait_event(intf->waitq, bmc->dyn_guid_set != 2);
3331 
3332 	/* dyn_guid_set makes the guid data available. */
3333 	smp_rmb();
3334 
3335 	intf->null_user_handler = NULL;
3336 }
3337 
3338 static int
3339 send_channel_info_cmd(struct ipmi_smi *intf, int chan)
3340 {
3341 	struct kernel_ipmi_msg            msg;
3342 	unsigned char                     data[1];
3343 	struct ipmi_system_interface_addr si;
3344 
3345 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
3346 	si.channel = IPMI_BMC_CHANNEL;
3347 	si.lun = 0;
3348 
3349 	msg.netfn = IPMI_NETFN_APP_REQUEST;
3350 	msg.cmd = IPMI_GET_CHANNEL_INFO_CMD;
3351 	msg.data = data;
3352 	msg.data_len = 1;
3353 	data[0] = chan;
3354 	return i_ipmi_request(NULL,
3355 			      intf,
3356 			      (struct ipmi_addr *) &si,
3357 			      0,
3358 			      &msg,
3359 			      intf,
3360 			      NULL,
3361 			      NULL,
3362 			      0,
3363 			      intf->addrinfo[0].address,
3364 			      intf->addrinfo[0].lun,
3365 			      -1, 0);
3366 }
3367 
3368 static void
3369 channel_handler(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
3370 {
3371 	int rv = 0;
3372 	int ch;
3373 	unsigned int set = intf->curr_working_cset;
3374 	struct ipmi_channel *chans;
3375 
3376 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
3377 	    && (msg->msg.netfn == IPMI_NETFN_APP_RESPONSE)
3378 	    && (msg->msg.cmd == IPMI_GET_CHANNEL_INFO_CMD)) {
3379 		/* It's the one we want */
3380 		if (msg->msg.data[0] != 0) {
3381 			/* Got an error from the channel, just go on. */
3382 			if (msg->msg.data[0] == IPMI_INVALID_COMMAND_ERR) {
3383 				/*
3384 				 * If the MC does not support this
3385 				 * command, that is legal.  We just
3386 				 * assume it has one IPMB at channel
3387 				 * zero.
3388 				 */
3389 				intf->wchannels[set].c[0].medium
3390 					= IPMI_CHANNEL_MEDIUM_IPMB;
3391 				intf->wchannels[set].c[0].protocol
3392 					= IPMI_CHANNEL_PROTOCOL_IPMB;
3393 
3394 				intf->channel_list = intf->wchannels + set;
3395 				intf->channels_ready = true;
3396 				wake_up(&intf->waitq);
3397 				goto out;
3398 			}
3399 			goto next_channel;
3400 		}
3401 		if (msg->msg.data_len < 4) {
3402 			/* Message not big enough, just go on. */
3403 			goto next_channel;
3404 		}
3405 		ch = intf->curr_channel;
3406 		chans = intf->wchannels[set].c;
3407 		chans[ch].medium = msg->msg.data[2] & 0x7f;
3408 		chans[ch].protocol = msg->msg.data[3] & 0x1f;
3409 
3410  next_channel:
3411 		intf->curr_channel++;
3412 		if (intf->curr_channel >= IPMI_MAX_CHANNELS) {
3413 			intf->channel_list = intf->wchannels + set;
3414 			intf->channels_ready = true;
3415 			wake_up(&intf->waitq);
3416 		} else {
3417 			intf->channel_list = intf->wchannels + set;
3418 			intf->channels_ready = true;
3419 			rv = send_channel_info_cmd(intf, intf->curr_channel);
3420 		}
3421 
3422 		if (rv) {
3423 			/* Got an error somehow, just give up. */
3424 			dev_warn(intf->si_dev,
3425 				 "Error sending channel information for channel %d: %d\n",
3426 				 intf->curr_channel, rv);
3427 
3428 			intf->channel_list = intf->wchannels + set;
3429 			intf->channels_ready = true;
3430 			wake_up(&intf->waitq);
3431 		}
3432 	}
3433  out:
3434 	return;
3435 }
3436 
3437 /*
3438  * Must be holding intf->bmc_reg_mutex to call this.
3439  */
3440 static int __scan_channels(struct ipmi_smi *intf, struct ipmi_device_id *id)
3441 {
3442 	int rv;
3443 
3444 	if (ipmi_version_major(id) > 1
3445 			|| (ipmi_version_major(id) == 1
3446 			    && ipmi_version_minor(id) >= 5)) {
3447 		unsigned int set;
3448 
3449 		/*
3450 		 * Start scanning the channels to see what is
3451 		 * available.
3452 		 */
3453 		set = !intf->curr_working_cset;
3454 		intf->curr_working_cset = set;
3455 		memset(&intf->wchannels[set], 0,
3456 		       sizeof(struct ipmi_channel_set));
3457 
3458 		intf->null_user_handler = channel_handler;
3459 		intf->curr_channel = 0;
3460 		rv = send_channel_info_cmd(intf, 0);
3461 		if (rv) {
3462 			dev_warn(intf->si_dev,
3463 				 "Error sending channel information for channel 0, %d\n",
3464 				 rv);
3465 			intf->null_user_handler = NULL;
3466 			return -EIO;
3467 		}
3468 
3469 		/* Wait for the channel info to be read. */
3470 		wait_event(intf->waitq, intf->channels_ready);
3471 		intf->null_user_handler = NULL;
3472 	} else {
3473 		unsigned int set = intf->curr_working_cset;
3474 
3475 		/* Assume a single IPMB channel at zero. */
3476 		intf->wchannels[set].c[0].medium = IPMI_CHANNEL_MEDIUM_IPMB;
3477 		intf->wchannels[set].c[0].protocol = IPMI_CHANNEL_PROTOCOL_IPMB;
3478 		intf->channel_list = intf->wchannels + set;
3479 		intf->channels_ready = true;
3480 	}
3481 
3482 	return 0;
3483 }
3484 
3485 static void ipmi_poll(struct ipmi_smi *intf)
3486 {
3487 	if (intf->handlers->poll)
3488 		intf->handlers->poll(intf->send_info);
3489 	/* In case something came in */
3490 	handle_new_recv_msgs(intf);
3491 }
3492 
3493 void ipmi_poll_interface(struct ipmi_user *user)
3494 {
3495 	ipmi_poll(user->intf);
3496 }
3497 EXPORT_SYMBOL(ipmi_poll_interface);
3498 
3499 static ssize_t nr_users_show(struct device *dev,
3500 			     struct device_attribute *attr,
3501 			     char *buf)
3502 {
3503 	struct ipmi_smi *intf = container_of(attr,
3504 			 struct ipmi_smi, nr_users_devattr);
3505 
3506 	return sysfs_emit(buf, "%d\n", atomic_read(&intf->nr_users));
3507 }
3508 static DEVICE_ATTR_RO(nr_users);
3509 
3510 static ssize_t nr_msgs_show(struct device *dev,
3511 			    struct device_attribute *attr,
3512 			    char *buf)
3513 {
3514 	struct ipmi_smi *intf = container_of(attr,
3515 					     struct ipmi_smi, nr_msgs_devattr);
3516 	struct ipmi_user *user;
3517 	unsigned int count = 0;
3518 
3519 	mutex_lock(&intf->users_mutex);
3520 	list_for_each_entry(user, &intf->users, link)
3521 		count += atomic_read(&user->nr_msgs);
3522 	mutex_unlock(&intf->users_mutex);
3523 
3524 	return sysfs_emit(buf, "%u\n", count);
3525 }
3526 static DEVICE_ATTR_RO(nr_msgs);
3527 
3528 static ssize_t maintenance_mode_show(struct device *dev,
3529 				     struct device_attribute *attr,
3530 				     char *buf)
3531 {
3532 	struct ipmi_smi *intf = container_of(attr,
3533 					     struct ipmi_smi,
3534 					     maintenance_mode_devattr);
3535 
3536 	return sysfs_emit(buf, "%u %d\n", intf->maintenance_mode_state,
3537 			  intf->auto_maintenance_timeout);
3538 }
3539 static DEVICE_ATTR_RO(maintenance_mode);
3540 
3541 static void redo_bmc_reg(struct work_struct *work)
3542 {
3543 	struct ipmi_smi *intf = container_of(work, struct ipmi_smi,
3544 					     bmc_reg_work);
3545 
3546 	if (!intf->in_shutdown)
3547 		bmc_get_device_id(intf, NULL, NULL, NULL, NULL);
3548 
3549 	kref_put(&intf->refcount, intf_free);
3550 }
3551 
3552 int ipmi_add_smi(struct module         *owner,
3553 		 const struct ipmi_smi_handlers *handlers,
3554 		 void		       *send_info,
3555 		 struct device         *si_dev,
3556 		 unsigned char         slave_addr)
3557 {
3558 	int              i, j;
3559 	int              rv;
3560 	struct ipmi_smi *intf, *tintf;
3561 	struct list_head *link;
3562 	struct ipmi_device_id id;
3563 
3564 	/*
3565 	 * Make sure the driver is actually initialized, this handles
3566 	 * problems with initialization order.
3567 	 */
3568 	rv = ipmi_init_msghandler();
3569 	if (rv)
3570 		return rv;
3571 
3572 	intf = kzalloc(sizeof(*intf), GFP_KERNEL);
3573 	if (!intf)
3574 		return -ENOMEM;
3575 
3576 	intf->owner = owner;
3577 	intf->bmc = &intf->tmp_bmc;
3578 	INIT_LIST_HEAD(&intf->bmc->intfs);
3579 	mutex_init(&intf->bmc->dyn_mutex);
3580 	INIT_LIST_HEAD(&intf->bmc_link);
3581 	mutex_init(&intf->bmc_reg_mutex);
3582 	intf->intf_num = -1; /* Mark it invalid for now. */
3583 	kref_init(&intf->refcount);
3584 	INIT_WORK(&intf->bmc_reg_work, redo_bmc_reg);
3585 	intf->si_dev = si_dev;
3586 	for (j = 0; j < IPMI_MAX_CHANNELS; j++) {
3587 		intf->addrinfo[j].address = IPMI_BMC_SLAVE_ADDR;
3588 		intf->addrinfo[j].lun = 2;
3589 	}
3590 	if (slave_addr != 0)
3591 		intf->addrinfo[0].address = slave_addr;
3592 	INIT_LIST_HEAD(&intf->user_msgs);
3593 	mutex_init(&intf->user_msgs_mutex);
3594 	INIT_LIST_HEAD(&intf->users);
3595 	mutex_init(&intf->users_mutex);
3596 	atomic_set(&intf->nr_users, 0);
3597 	intf->handlers = handlers;
3598 	intf->send_info = send_info;
3599 	mutex_init(&intf->seq_lock);
3600 	for (j = 0; j < IPMI_IPMB_NUM_SEQ; j++) {
3601 		intf->seq_table[j].inuse = 0;
3602 		intf->seq_table[j].seqid = 0;
3603 	}
3604 	intf->curr_seq = 0;
3605 	spin_lock_init(&intf->waiting_rcv_msgs_lock);
3606 	INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
3607 	INIT_WORK(&intf->smi_work, smi_work);
3608 	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 0);
3609 	spin_lock_init(&intf->xmit_msgs_lock);
3610 	INIT_LIST_HEAD(&intf->xmit_msgs);
3611 	INIT_LIST_HEAD(&intf->hp_xmit_msgs);
3612 	mutex_init(&intf->events_mutex);
3613 	spin_lock_init(&intf->watch_lock);
3614 	atomic_set(&intf->event_waiters, 0);
3615 	intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
3616 	INIT_LIST_HEAD(&intf->waiting_events);
3617 	intf->waiting_events_count = 0;
3618 	mutex_init(&intf->cmd_rcvrs_mutex);
3619 	spin_lock_init(&intf->maintenance_mode_lock);
3620 	INIT_LIST_HEAD(&intf->cmd_rcvrs);
3621 	init_waitqueue_head(&intf->waitq);
3622 	for (i = 0; i < IPMI_NUM_STATS; i++)
3623 		atomic_set(&intf->stats[i], 0);
3624 
3625 	/*
3626 	 * Grab the watchers mutex so we can deliver the new interface
3627 	 * without races.
3628 	 */
3629 	mutex_lock(&smi_watchers_mutex);
3630 	mutex_lock(&ipmi_interfaces_mutex);
3631 	/* Look for a hole in the numbers. */
3632 	i = 0;
3633 	link = &ipmi_interfaces;
3634 	list_for_each_entry(tintf, &ipmi_interfaces, link) {
3635 		if (tintf->intf_num != i) {
3636 			link = &tintf->link;
3637 			break;
3638 		}
3639 		i++;
3640 	}
3641 	/* Add the new interface in numeric order. */
3642 	if (i == 0)
3643 		list_add(&intf->link, &ipmi_interfaces);
3644 	else
3645 		list_add_tail(&intf->link, link);
3646 
3647 	rv = handlers->start_processing(send_info, intf);
3648 	if (rv)
3649 		goto out_err;
3650 
3651 	rv = __bmc_get_device_id(intf, NULL, &id, NULL, NULL, i);
3652 	if (rv) {
3653 		dev_err(si_dev, "Unable to get the device id: %d\n", rv);
3654 		goto out_err_started;
3655 	}
3656 
3657 	mutex_lock(&intf->bmc_reg_mutex);
3658 	rv = __scan_channels(intf, &id);
3659 	mutex_unlock(&intf->bmc_reg_mutex);
3660 	if (rv)
3661 		goto out_err_bmc_reg;
3662 
3663 	intf->nr_users_devattr = dev_attr_nr_users;
3664 	sysfs_attr_init(&intf->nr_users_devattr.attr);
3665 	rv = device_create_file(intf->si_dev, &intf->nr_users_devattr);
3666 	if (rv)
3667 		goto out_err_bmc_reg;
3668 
3669 	intf->nr_msgs_devattr = dev_attr_nr_msgs;
3670 	sysfs_attr_init(&intf->nr_msgs_devattr.attr);
3671 	rv = device_create_file(intf->si_dev, &intf->nr_msgs_devattr);
3672 	if (rv) {
3673 		device_remove_file(intf->si_dev, &intf->nr_users_devattr);
3674 		goto out_err_bmc_reg;
3675 	}
3676 
3677 	intf->maintenance_mode_devattr = dev_attr_maintenance_mode;
3678 	sysfs_attr_init(&intf->maintenance_mode_devattr.attr);
3679 	rv = device_create_file(intf->si_dev, &intf->maintenance_mode_devattr);
3680 	if (rv) {
3681 		device_remove_file(intf->si_dev, &intf->nr_users_devattr);
3682 		goto out_err_bmc_reg;
3683 	}
3684 
3685 	intf->intf_num = i;
3686 	mutex_unlock(&ipmi_interfaces_mutex);
3687 
3688 	/* After this point the interface is legal to use. */
3689 	call_smi_watchers(i, intf->si_dev);
3690 
3691 	mutex_unlock(&smi_watchers_mutex);
3692 
3693 	return 0;
3694 
3695  out_err_bmc_reg:
3696 	ipmi_bmc_unregister(intf);
3697  out_err_started:
3698 	if (intf->handlers->shutdown)
3699 		intf->handlers->shutdown(intf->send_info);
3700  out_err:
3701 	list_del(&intf->link);
3702 	mutex_unlock(&ipmi_interfaces_mutex);
3703 	mutex_unlock(&smi_watchers_mutex);
3704 	kref_put(&intf->refcount, intf_free);
3705 
3706 	return rv;
3707 }
3708 EXPORT_SYMBOL(ipmi_add_smi);
3709 
3710 static void deliver_smi_err_response(struct ipmi_smi *intf,
3711 				     struct ipmi_smi_msg *msg,
3712 				     unsigned char err)
3713 {
3714 	int rv;
3715 	msg->rsp[0] = msg->data[0] | 4;
3716 	msg->rsp[1] = msg->data[1];
3717 	msg->rsp[2] = err;
3718 	msg->rsp_size = 3;
3719 
3720 	/* This will never requeue, but it may ask us to free the message. */
3721 	rv = handle_one_recv_msg(intf, msg);
3722 	if (rv == 0)
3723 		ipmi_free_smi_msg(msg);
3724 }
3725 
3726 static void cleanup_smi_msgs(struct ipmi_smi *intf)
3727 {
3728 	int              i;
3729 	struct seq_table *ent;
3730 	struct ipmi_smi_msg *msg;
3731 	struct list_head *entry;
3732 	struct list_head tmplist;
3733 
3734 	/* Clear out our transmit queues and hold the messages. */
3735 	INIT_LIST_HEAD(&tmplist);
3736 	list_splice_tail(&intf->hp_xmit_msgs, &tmplist);
3737 	list_splice_tail(&intf->xmit_msgs, &tmplist);
3738 
3739 	/* Current message first, to preserve order */
3740 	while (intf->curr_msg && !list_empty(&intf->waiting_rcv_msgs)) {
3741 		/* Wait for the message to clear out. */
3742 		schedule_timeout(1);
3743 	}
3744 
3745 	/* No need for locks, the interface is down. */
3746 
3747 	/*
3748 	 * Return errors for all pending messages in queue and in the
3749 	 * tables waiting for remote responses.
3750 	 */
3751 	while (!list_empty(&tmplist)) {
3752 		entry = tmplist.next;
3753 		list_del(entry);
3754 		msg = list_entry(entry, struct ipmi_smi_msg, link);
3755 		deliver_smi_err_response(intf, msg, IPMI_ERR_UNSPECIFIED);
3756 	}
3757 
3758 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
3759 		ent = &intf->seq_table[i];
3760 		if (!ent->inuse)
3761 			continue;
3762 		deliver_err_response(intf, ent->recv_msg, IPMI_ERR_UNSPECIFIED);
3763 	}
3764 }
3765 
3766 void ipmi_unregister_smi(struct ipmi_smi *intf)
3767 {
3768 	struct ipmi_smi_watcher *w;
3769 	int intf_num;
3770 
3771 	if (!intf)
3772 		return;
3773 
3774 	intf_num = intf->intf_num;
3775 	mutex_lock(&ipmi_interfaces_mutex);
3776 	cancel_work_sync(&intf->smi_work);
3777 	/* smi_work() can no longer be in progress after this. */
3778 
3779 	intf->intf_num = -1;
3780 	intf->in_shutdown = true;
3781 	list_del(&intf->link);
3782 	mutex_unlock(&ipmi_interfaces_mutex);
3783 
3784 	/*
3785 	 * At this point no users can be added to the interface and no
3786 	 * new messages can be sent.
3787 	 */
3788 
3789 	if (intf->handlers->shutdown)
3790 		intf->handlers->shutdown(intf->send_info);
3791 
3792 	device_remove_file(intf->si_dev, &intf->maintenance_mode_devattr);
3793 	device_remove_file(intf->si_dev, &intf->nr_msgs_devattr);
3794 	device_remove_file(intf->si_dev, &intf->nr_users_devattr);
3795 
3796 	/*
3797 	 * Call all the watcher interfaces to tell them that
3798 	 * an interface is going away.
3799 	 */
3800 	mutex_lock(&smi_watchers_mutex);
3801 	list_for_each_entry(w, &smi_watchers, link)
3802 		w->smi_gone(intf_num);
3803 	mutex_unlock(&smi_watchers_mutex);
3804 
3805 	mutex_lock(&intf->users_mutex);
3806 	while (!list_empty(&intf->users)) {
3807 		struct ipmi_user *user = list_first_entry(&intf->users,
3808 						    struct ipmi_user, link);
3809 
3810 		_ipmi_destroy_user(user);
3811 	}
3812 	mutex_unlock(&intf->users_mutex);
3813 
3814 	cleanup_smi_msgs(intf);
3815 
3816 	ipmi_bmc_unregister(intf);
3817 
3818 	kref_put(&intf->refcount, intf_free);
3819 }
3820 EXPORT_SYMBOL(ipmi_unregister_smi);
3821 
3822 static int handle_ipmb_get_msg_rsp(struct ipmi_smi *intf,
3823 				   struct ipmi_smi_msg *msg)
3824 {
3825 	struct ipmi_ipmb_addr ipmb_addr;
3826 	struct ipmi_recv_msg  *recv_msg;
3827 
3828 	/*
3829 	 * This is 11, not 10, because the response must contain a
3830 	 * completion code.
3831 	 */
3832 	if (msg->rsp_size < 11) {
3833 		/* Message not big enough, just ignore it. */
3834 		ipmi_inc_stat(intf, invalid_ipmb_responses);
3835 		return 0;
3836 	}
3837 
3838 	if (msg->rsp[2] != 0) {
3839 		/* An error getting the response, just ignore it. */
3840 		return 0;
3841 	}
3842 
3843 	ipmb_addr.addr_type = IPMI_IPMB_ADDR_TYPE;
3844 	ipmb_addr.slave_addr = msg->rsp[6];
3845 	ipmb_addr.channel = msg->rsp[3] & 0x0f;
3846 	ipmb_addr.lun = msg->rsp[7] & 3;
3847 
3848 	/*
3849 	 * It's a response from a remote entity.  Look up the sequence
3850 	 * number and handle the response.
3851 	 */
3852 	if (intf_find_seq(intf,
3853 			  msg->rsp[7] >> 2,
3854 			  msg->rsp[3] & 0x0f,
3855 			  msg->rsp[8],
3856 			  (msg->rsp[4] >> 2) & (~1),
3857 			  (struct ipmi_addr *) &ipmb_addr,
3858 			  &recv_msg)) {
3859 		/*
3860 		 * We were unable to find the sequence number,
3861 		 * so just nuke the message.
3862 		 */
3863 		ipmi_inc_stat(intf, unhandled_ipmb_responses);
3864 		return 0;
3865 	}
3866 
3867 	memcpy(recv_msg->msg_data, &msg->rsp[9], msg->rsp_size - 9);
3868 	/*
3869 	 * The other fields matched, so no need to set them, except
3870 	 * for netfn, which needs to be the response that was
3871 	 * returned, not the request value.
3872 	 */
3873 	recv_msg->msg.netfn = msg->rsp[4] >> 2;
3874 	recv_msg->msg.data = recv_msg->msg_data;
3875 	recv_msg->msg.data_len = msg->rsp_size - 10;
3876 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
3877 	if (deliver_response(intf, recv_msg))
3878 		ipmi_inc_stat(intf, unhandled_ipmb_responses);
3879 	else
3880 		ipmi_inc_stat(intf, handled_ipmb_responses);
3881 
3882 	return 0;
3883 }
3884 
3885 static int handle_ipmb_get_msg_cmd(struct ipmi_smi *intf,
3886 				   struct ipmi_smi_msg *msg)
3887 {
3888 	struct cmd_rcvr          *rcvr;
3889 	int                      rv = 0;
3890 	unsigned char            netfn;
3891 	unsigned char            cmd;
3892 	unsigned char            chan;
3893 	struct ipmi_user         *user = NULL;
3894 	struct ipmi_ipmb_addr    *ipmb_addr;
3895 	struct ipmi_recv_msg     *recv_msg = NULL;
3896 
3897 	if (msg->rsp_size < 10) {
3898 		/* Message not big enough, just ignore it. */
3899 		ipmi_inc_stat(intf, invalid_commands);
3900 		return 0;
3901 	}
3902 
3903 	if (msg->rsp[2] != 0) {
3904 		/* An error getting the response, just ignore it. */
3905 		return 0;
3906 	}
3907 
3908 	netfn = msg->rsp[4] >> 2;
3909 	cmd = msg->rsp[8];
3910 	chan = msg->rsp[3] & 0xf;
3911 
3912 	rcu_read_lock();
3913 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
3914 	if (rcvr) {
3915 		user = rcvr->user;
3916 		recv_msg = ipmi_alloc_recv_msg(user);
3917 	}
3918 	rcu_read_unlock();
3919 
3920 	if (user == NULL) {
3921 		/* We didn't find a user, deliver an error response. */
3922 		ipmi_inc_stat(intf, unhandled_commands);
3923 
3924 		msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
3925 		msg->data[1] = IPMI_SEND_MSG_CMD;
3926 		msg->data[2] = msg->rsp[3];
3927 		msg->data[3] = msg->rsp[6];
3928 		msg->data[4] = ((netfn + 1) << 2) | (msg->rsp[7] & 0x3);
3929 		msg->data[5] = ipmb_checksum(&msg->data[3], 2);
3930 		msg->data[6] = intf->addrinfo[msg->rsp[3] & 0xf].address;
3931 		/* rqseq/lun */
3932 		msg->data[7] = (msg->rsp[7] & 0xfc) | (msg->rsp[4] & 0x3);
3933 		msg->data[8] = msg->rsp[8]; /* cmd */
3934 		msg->data[9] = IPMI_INVALID_CMD_COMPLETION_CODE;
3935 		msg->data[10] = ipmb_checksum(&msg->data[6], 4);
3936 		msg->data_size = 11;
3937 
3938 		dev_dbg(intf->si_dev, "Invalid command: %*ph\n",
3939 			msg->data_size, msg->data);
3940 
3941 		smi_send(intf, intf->handlers, msg, 0);
3942 		/*
3943 		 * We used the message, so return the value that
3944 		 * causes it to not be freed or queued.
3945 		 */
3946 		rv = -1;
3947 	} else if (!IS_ERR(recv_msg)) {
3948 		/* Extract the source address from the data. */
3949 		ipmb_addr = (struct ipmi_ipmb_addr *) &recv_msg->addr;
3950 		ipmb_addr->addr_type = IPMI_IPMB_ADDR_TYPE;
3951 		ipmb_addr->slave_addr = msg->rsp[6];
3952 		ipmb_addr->lun = msg->rsp[7] & 3;
3953 		ipmb_addr->channel = msg->rsp[3] & 0xf;
3954 
3955 		/*
3956 		 * Extract the rest of the message information
3957 		 * from the IPMB header.
3958 		 */
3959 		recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
3960 		recv_msg->msgid = msg->rsp[7] >> 2;
3961 		recv_msg->msg.netfn = msg->rsp[4] >> 2;
3962 		recv_msg->msg.cmd = msg->rsp[8];
3963 		recv_msg->msg.data = recv_msg->msg_data;
3964 
3965 		/*
3966 		 * We chop off 10, not 9 bytes because the checksum
3967 		 * at the end also needs to be removed.
3968 		 */
3969 		recv_msg->msg.data_len = msg->rsp_size - 10;
3970 		memcpy(recv_msg->msg_data, &msg->rsp[9],
3971 		       msg->rsp_size - 10);
3972 		if (deliver_response(intf, recv_msg))
3973 			ipmi_inc_stat(intf, unhandled_commands);
3974 		else
3975 			ipmi_inc_stat(intf, handled_commands);
3976 	} else {
3977 		/*
3978 		 * We couldn't allocate memory for the message, so
3979 		 * requeue it for handling later.
3980 		 */
3981 		rv = 1;
3982 	}
3983 
3984 	return rv;
3985 }
3986 
3987 static int handle_ipmb_direct_rcv_cmd(struct ipmi_smi *intf,
3988 				      struct ipmi_smi_msg *msg)
3989 {
3990 	struct cmd_rcvr          *rcvr;
3991 	int                      rv = 0;
3992 	struct ipmi_user         *user = NULL;
3993 	struct ipmi_ipmb_direct_addr *daddr;
3994 	struct ipmi_recv_msg     *recv_msg = NULL;
3995 	unsigned char netfn = msg->rsp[0] >> 2;
3996 	unsigned char cmd = msg->rsp[3];
3997 
3998 	rcu_read_lock();
3999 	/* We always use channel 0 for direct messages. */
4000 	rcvr = find_cmd_rcvr(intf, netfn, cmd, 0);
4001 	if (rcvr) {
4002 		user = rcvr->user;
4003 		recv_msg = ipmi_alloc_recv_msg(user);
4004 	}
4005 	rcu_read_unlock();
4006 
4007 	if (user == NULL) {
4008 		/* We didn't find a user, deliver an error response. */
4009 		ipmi_inc_stat(intf, unhandled_commands);
4010 
4011 		msg->data[0] = (netfn + 1) << 2;
4012 		msg->data[0] |= msg->rsp[2] & 0x3; /* rqLUN */
4013 		msg->data[1] = msg->rsp[1]; /* Addr */
4014 		msg->data[2] = msg->rsp[2] & ~0x3; /* rqSeq */
4015 		msg->data[2] |= msg->rsp[0] & 0x3; /* rsLUN */
4016 		msg->data[3] = cmd;
4017 		msg->data[4] = IPMI_INVALID_CMD_COMPLETION_CODE;
4018 		msg->data_size = 5;
4019 
4020 		smi_send(intf, intf->handlers, msg, 0);
4021 		/*
4022 		 * We used the message, so return the value that
4023 		 * causes it to not be freed or queued.
4024 		 */
4025 		rv = -1;
4026 	} else if (!IS_ERR(recv_msg)) {
4027 		/* Extract the source address from the data. */
4028 		daddr = (struct ipmi_ipmb_direct_addr *)&recv_msg->addr;
4029 		daddr->addr_type = IPMI_IPMB_DIRECT_ADDR_TYPE;
4030 		daddr->channel = 0;
4031 		daddr->slave_addr = msg->rsp[1];
4032 		daddr->rs_lun = msg->rsp[0] & 3;
4033 		daddr->rq_lun = msg->rsp[2] & 3;
4034 
4035 		/*
4036 		 * Extract the rest of the message information
4037 		 * from the IPMB header.
4038 		 */
4039 		recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
4040 		recv_msg->msgid = (msg->rsp[2] >> 2);
4041 		recv_msg->msg.netfn = msg->rsp[0] >> 2;
4042 		recv_msg->msg.cmd = msg->rsp[3];
4043 		recv_msg->msg.data = recv_msg->msg_data;
4044 
4045 		recv_msg->msg.data_len = msg->rsp_size - 4;
4046 		memcpy(recv_msg->msg_data, msg->rsp + 4,
4047 		       msg->rsp_size - 4);
4048 		if (deliver_response(intf, recv_msg))
4049 			ipmi_inc_stat(intf, unhandled_commands);
4050 		else
4051 			ipmi_inc_stat(intf, handled_commands);
4052 	} else {
4053 		/*
4054 		 * We couldn't allocate memory for the message, so
4055 		 * requeue it for handling later.
4056 		 */
4057 		rv = 1;
4058 	}
4059 
4060 	return rv;
4061 }
4062 
4063 static int handle_ipmb_direct_rcv_rsp(struct ipmi_smi *intf,
4064 				      struct ipmi_smi_msg *msg)
4065 {
4066 	struct ipmi_recv_msg *recv_msg;
4067 	struct ipmi_ipmb_direct_addr *daddr;
4068 
4069 	recv_msg = msg->recv_msg;
4070 	if (recv_msg == NULL) {
4071 		dev_warn(intf->si_dev,
4072 			 "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");
4073 		return 0;
4074 	}
4075 
4076 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
4077 	recv_msg->msgid = msg->msgid;
4078 	daddr = (struct ipmi_ipmb_direct_addr *) &recv_msg->addr;
4079 	daddr->addr_type = IPMI_IPMB_DIRECT_ADDR_TYPE;
4080 	daddr->channel = 0;
4081 	daddr->slave_addr = msg->rsp[1];
4082 	daddr->rq_lun = msg->rsp[0] & 3;
4083 	daddr->rs_lun = msg->rsp[2] & 3;
4084 	recv_msg->msg.netfn = msg->rsp[0] >> 2;
4085 	recv_msg->msg.cmd = msg->rsp[3];
4086 	memcpy(recv_msg->msg_data, &msg->rsp[4], msg->rsp_size - 4);
4087 	recv_msg->msg.data = recv_msg->msg_data;
4088 	recv_msg->msg.data_len = msg->rsp_size - 4;
4089 	deliver_local_response(intf, recv_msg);
4090 
4091 	return 0;
4092 }
4093 
4094 static int handle_lan_get_msg_rsp(struct ipmi_smi *intf,
4095 				  struct ipmi_smi_msg *msg)
4096 {
4097 	struct ipmi_lan_addr  lan_addr;
4098 	struct ipmi_recv_msg  *recv_msg;
4099 
4100 
4101 	/*
4102 	 * This is 13, not 12, because the response must contain a
4103 	 * completion code.
4104 	 */
4105 	if (msg->rsp_size < 13) {
4106 		/* Message not big enough, just ignore it. */
4107 		ipmi_inc_stat(intf, invalid_lan_responses);
4108 		return 0;
4109 	}
4110 
4111 	if (msg->rsp[2] != 0) {
4112 		/* An error getting the response, just ignore it. */
4113 		return 0;
4114 	}
4115 
4116 	lan_addr.addr_type = IPMI_LAN_ADDR_TYPE;
4117 	lan_addr.session_handle = msg->rsp[4];
4118 	lan_addr.remote_SWID = msg->rsp[8];
4119 	lan_addr.local_SWID = msg->rsp[5];
4120 	lan_addr.channel = msg->rsp[3] & 0x0f;
4121 	lan_addr.privilege = msg->rsp[3] >> 4;
4122 	lan_addr.lun = msg->rsp[9] & 3;
4123 
4124 	/*
4125 	 * It's a response from a remote entity.  Look up the sequence
4126 	 * number and handle the response.
4127 	 */
4128 	if (intf_find_seq(intf,
4129 			  msg->rsp[9] >> 2,
4130 			  msg->rsp[3] & 0x0f,
4131 			  msg->rsp[10],
4132 			  (msg->rsp[6] >> 2) & (~1),
4133 			  (struct ipmi_addr *) &lan_addr,
4134 			  &recv_msg)) {
4135 		/*
4136 		 * We were unable to find the sequence number,
4137 		 * so just nuke the message.
4138 		 */
4139 		ipmi_inc_stat(intf, unhandled_lan_responses);
4140 		return 0;
4141 	}
4142 
4143 	memcpy(recv_msg->msg_data, &msg->rsp[11], msg->rsp_size - 11);
4144 	/*
4145 	 * The other fields matched, so no need to set them, except
4146 	 * for netfn, which needs to be the response that was
4147 	 * returned, not the request value.
4148 	 */
4149 	recv_msg->msg.netfn = msg->rsp[6] >> 2;
4150 	recv_msg->msg.data = recv_msg->msg_data;
4151 	recv_msg->msg.data_len = msg->rsp_size - 12;
4152 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
4153 	if (deliver_response(intf, recv_msg))
4154 		ipmi_inc_stat(intf, unhandled_lan_responses);
4155 	else
4156 		ipmi_inc_stat(intf, handled_lan_responses);
4157 
4158 	return 0;
4159 }
4160 
4161 static int handle_lan_get_msg_cmd(struct ipmi_smi *intf,
4162 				  struct ipmi_smi_msg *msg)
4163 {
4164 	struct cmd_rcvr          *rcvr;
4165 	int                      rv = 0;
4166 	unsigned char            netfn;
4167 	unsigned char            cmd;
4168 	unsigned char            chan;
4169 	struct ipmi_user         *user = NULL;
4170 	struct ipmi_lan_addr     *lan_addr;
4171 	struct ipmi_recv_msg     *recv_msg = NULL;
4172 
4173 	if (msg->rsp_size < 12) {
4174 		/* Message not big enough, just ignore it. */
4175 		ipmi_inc_stat(intf, invalid_commands);
4176 		return 0;
4177 	}
4178 
4179 	if (msg->rsp[2] != 0) {
4180 		/* An error getting the response, just ignore it. */
4181 		return 0;
4182 	}
4183 
4184 	netfn = msg->rsp[6] >> 2;
4185 	cmd = msg->rsp[10];
4186 	chan = msg->rsp[3] & 0xf;
4187 
4188 	rcu_read_lock();
4189 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
4190 	if (rcvr) {
4191 		user = rcvr->user;
4192 		recv_msg = ipmi_alloc_recv_msg(user);
4193 	}
4194 	rcu_read_unlock();
4195 
4196 	if (user == NULL) {
4197 		/* We didn't find a user, just give up and return an error. */
4198 		ipmi_inc_stat(intf, unhandled_commands);
4199 
4200 		msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
4201 		msg->data[1] = IPMI_SEND_MSG_CMD;
4202 		msg->data[2] = chan;
4203 		msg->data[3] = msg->rsp[4]; /* handle */
4204 		msg->data[4] = msg->rsp[8]; /* rsSWID */
4205 		msg->data[5] = ((netfn + 1) << 2) | (msg->rsp[9] & 0x3);
4206 		msg->data[6] = ipmb_checksum(&msg->data[3], 3);
4207 		msg->data[7] = msg->rsp[5]; /* rqSWID */
4208 		/* rqseq/lun */
4209 		msg->data[8] = (msg->rsp[9] & 0xfc) | (msg->rsp[6] & 0x3);
4210 		msg->data[9] = cmd;
4211 		msg->data[10] = IPMI_INVALID_CMD_COMPLETION_CODE;
4212 		msg->data[11] = ipmb_checksum(&msg->data[7], 4);
4213 		msg->data_size = 12;
4214 
4215 		dev_dbg(intf->si_dev, "Invalid command: %*ph\n",
4216 			msg->data_size, msg->data);
4217 
4218 		smi_send(intf, intf->handlers, msg, 0);
4219 		/*
4220 		 * We used the message, so return the value that
4221 		 * causes it to not be freed or queued.
4222 		 */
4223 		rv = -1;
4224 	} else if (!IS_ERR(recv_msg)) {
4225 		/* Extract the source address from the data. */
4226 		lan_addr = (struct ipmi_lan_addr *) &recv_msg->addr;
4227 		lan_addr->addr_type = IPMI_LAN_ADDR_TYPE;
4228 		lan_addr->session_handle = msg->rsp[4];
4229 		lan_addr->remote_SWID = msg->rsp[8];
4230 		lan_addr->local_SWID = msg->rsp[5];
4231 		lan_addr->lun = msg->rsp[9] & 3;
4232 		lan_addr->channel = msg->rsp[3] & 0xf;
4233 		lan_addr->privilege = msg->rsp[3] >> 4;
4234 
4235 		/*
4236 		 * Extract the rest of the message information
4237 		 * from the IPMB header.
4238 		 */
4239 		recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
4240 		recv_msg->msgid = msg->rsp[9] >> 2;
4241 		recv_msg->msg.netfn = msg->rsp[6] >> 2;
4242 		recv_msg->msg.cmd = msg->rsp[10];
4243 		recv_msg->msg.data = recv_msg->msg_data;
4244 
4245 		/*
4246 		 * We chop off 12, not 11 bytes because the checksum
4247 		 * at the end also needs to be removed.
4248 		 */
4249 		recv_msg->msg.data_len = msg->rsp_size - 12;
4250 		memcpy(recv_msg->msg_data, &msg->rsp[11],
4251 		       msg->rsp_size - 12);
4252 		if (deliver_response(intf, recv_msg))
4253 			ipmi_inc_stat(intf, unhandled_commands);
4254 		else
4255 			ipmi_inc_stat(intf, handled_commands);
4256 	} else {
4257 		/*
4258 		 * We couldn't allocate memory for the message, so
4259 		 * requeue it for handling later.
4260 		 */
4261 		rv = 1;
4262 	}
4263 
4264 	return rv;
4265 }
4266 
4267 /*
4268  * This routine will handle "Get Message" command responses with
4269  * channels that use an OEM Medium. The message format belongs to
4270  * the OEM.  See IPMI 2.0 specification, Chapter 6 and
4271  * Chapter 22, sections 22.6 and 22.24 for more details.
4272  */
4273 static int handle_oem_get_msg_cmd(struct ipmi_smi *intf,
4274 				  struct ipmi_smi_msg *msg)
4275 {
4276 	struct cmd_rcvr       *rcvr;
4277 	int                   rv = 0;
4278 	unsigned char         netfn;
4279 	unsigned char         cmd;
4280 	unsigned char         chan;
4281 	struct ipmi_user *user = NULL;
4282 	struct ipmi_system_interface_addr *smi_addr;
4283 	struct ipmi_recv_msg  *recv_msg = NULL;
4284 
4285 	/*
4286 	 * We expect the OEM SW to perform error checking
4287 	 * so we just do some basic sanity checks
4288 	 */
4289 	if (msg->rsp_size < 4) {
4290 		/* Message not big enough, just ignore it. */
4291 		ipmi_inc_stat(intf, invalid_commands);
4292 		return 0;
4293 	}
4294 
4295 	if (msg->rsp[2] != 0) {
4296 		/* An error getting the response, just ignore it. */
4297 		return 0;
4298 	}
4299 
4300 	/*
4301 	 * This is an OEM Message so the OEM needs to know how
4302 	 * handle the message. We do no interpretation.
4303 	 */
4304 	netfn = msg->rsp[0] >> 2;
4305 	cmd = msg->rsp[1];
4306 	chan = msg->rsp[3] & 0xf;
4307 
4308 	rcu_read_lock();
4309 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
4310 	if (rcvr) {
4311 		user = rcvr->user;
4312 		recv_msg = ipmi_alloc_recv_msg(user);
4313 	}
4314 	rcu_read_unlock();
4315 
4316 	if (user == NULL) {
4317 		/* We didn't find a user, just give up. */
4318 		ipmi_inc_stat(intf, unhandled_commands);
4319 
4320 		/*
4321 		 * Don't do anything with these messages, just allow
4322 		 * them to be freed.
4323 		 */
4324 
4325 		rv = 0;
4326 	} else if (!IS_ERR(recv_msg)) {
4327 		/*
4328 		 * OEM Messages are expected to be delivered via
4329 		 * the system interface to SMS software.  We might
4330 		 * need to visit this again depending on OEM
4331 		 * requirements
4332 		 */
4333 		smi_addr = ((struct ipmi_system_interface_addr *)
4334 			    &recv_msg->addr);
4335 		smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4336 		smi_addr->channel = IPMI_BMC_CHANNEL;
4337 		smi_addr->lun = msg->rsp[0] & 3;
4338 
4339 		recv_msg->user_msg_data = NULL;
4340 		recv_msg->recv_type = IPMI_OEM_RECV_TYPE;
4341 		recv_msg->msg.netfn = msg->rsp[0] >> 2;
4342 		recv_msg->msg.cmd = msg->rsp[1];
4343 		recv_msg->msg.data = recv_msg->msg_data;
4344 
4345 		/*
4346 		 * The message starts at byte 4 which follows the
4347 		 * Channel Byte in the "GET MESSAGE" command
4348 		 */
4349 		recv_msg->msg.data_len = msg->rsp_size - 4;
4350 		memcpy(recv_msg->msg_data, &msg->rsp[4],
4351 		       msg->rsp_size - 4);
4352 		if (deliver_response(intf, recv_msg))
4353 			ipmi_inc_stat(intf, unhandled_commands);
4354 		else
4355 			ipmi_inc_stat(intf, handled_commands);
4356 	} else {
4357 		/*
4358 		 * We couldn't allocate memory for the message, so
4359 		 * requeue it for handling later.
4360 		 */
4361 		rv = 1;
4362 	}
4363 
4364 	return rv;
4365 }
4366 
4367 static void copy_event_into_recv_msg(struct ipmi_recv_msg *recv_msg,
4368 				     struct ipmi_smi_msg  *msg)
4369 {
4370 	struct ipmi_system_interface_addr *smi_addr;
4371 
4372 	recv_msg->msgid = 0;
4373 	smi_addr = (struct ipmi_system_interface_addr *) &recv_msg->addr;
4374 	smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4375 	smi_addr->channel = IPMI_BMC_CHANNEL;
4376 	smi_addr->lun = msg->rsp[0] & 3;
4377 	recv_msg->recv_type = IPMI_ASYNC_EVENT_RECV_TYPE;
4378 	recv_msg->msg.netfn = msg->rsp[0] >> 2;
4379 	recv_msg->msg.cmd = msg->rsp[1];
4380 	memcpy(recv_msg->msg_data, &msg->rsp[3], msg->rsp_size - 3);
4381 	recv_msg->msg.data = recv_msg->msg_data;
4382 	recv_msg->msg.data_len = msg->rsp_size - 3;
4383 }
4384 
4385 static int handle_read_event_rsp(struct ipmi_smi *intf,
4386 				 struct ipmi_smi_msg *msg)
4387 {
4388 	struct ipmi_recv_msg *recv_msg, *recv_msg2;
4389 	struct list_head     msgs;
4390 	struct ipmi_user     *user;
4391 	int rv = 0, deliver_count = 0;
4392 
4393 	if (msg->rsp_size < 19) {
4394 		/* Message is too small to be an IPMB event. */
4395 		ipmi_inc_stat(intf, invalid_events);
4396 		return 0;
4397 	}
4398 
4399 	if (msg->rsp[2] != 0) {
4400 		/* An error getting the event, just ignore it. */
4401 		return 0;
4402 	}
4403 
4404 	INIT_LIST_HEAD(&msgs);
4405 
4406 	mutex_lock(&intf->events_mutex);
4407 
4408 	ipmi_inc_stat(intf, events);
4409 
4410 	/*
4411 	 * Allocate and fill in one message for every user that is
4412 	 * getting events.
4413 	 */
4414 	mutex_lock(&intf->users_mutex);
4415 	list_for_each_entry(user, &intf->users, link) {
4416 		if (!user->gets_events)
4417 			continue;
4418 
4419 		recv_msg = ipmi_alloc_recv_msg(user);
4420 		if (IS_ERR(recv_msg)) {
4421 			mutex_unlock(&intf->users_mutex);
4422 			list_for_each_entry_safe(recv_msg, recv_msg2, &msgs,
4423 						 link) {
4424 				user = recv_msg->user;
4425 				list_del(&recv_msg->link);
4426 				ipmi_free_recv_msg(recv_msg);
4427 				kref_put(&user->refcount, free_ipmi_user);
4428 			}
4429 			/*
4430 			 * We couldn't allocate memory for the
4431 			 * message, so requeue it for handling
4432 			 * later.
4433 			 */
4434 			rv = 1;
4435 			goto out;
4436 		}
4437 
4438 		deliver_count++;
4439 
4440 		copy_event_into_recv_msg(recv_msg, msg);
4441 		list_add_tail(&recv_msg->link, &msgs);
4442 	}
4443 	mutex_unlock(&intf->users_mutex);
4444 
4445 	if (deliver_count) {
4446 		/* Now deliver all the messages. */
4447 		list_for_each_entry_safe(recv_msg, recv_msg2, &msgs, link) {
4448 			list_del(&recv_msg->link);
4449 			deliver_local_response(intf, recv_msg);
4450 		}
4451 	} else if (intf->waiting_events_count < MAX_EVENTS_IN_QUEUE) {
4452 		/*
4453 		 * No one to receive the message, put it in queue if there's
4454 		 * not already too many things in the queue.
4455 		 */
4456 		recv_msg = ipmi_alloc_recv_msg(NULL);
4457 		if (IS_ERR(recv_msg)) {
4458 			/*
4459 			 * We couldn't allocate memory for the
4460 			 * message, so requeue it for handling
4461 			 * later.
4462 			 */
4463 			rv = 1;
4464 			goto out;
4465 		}
4466 
4467 		copy_event_into_recv_msg(recv_msg, msg);
4468 		list_add_tail(&recv_msg->link, &intf->waiting_events);
4469 		intf->waiting_events_count++;
4470 	} else if (!intf->event_msg_printed) {
4471 		/*
4472 		 * There's too many things in the queue, discard this
4473 		 * message.
4474 		 */
4475 		dev_warn(intf->si_dev,
4476 			 "Event queue full, discarding incoming events\n");
4477 		intf->event_msg_printed = 1;
4478 	}
4479 
4480  out:
4481 	mutex_unlock(&intf->events_mutex);
4482 
4483 	return rv;
4484 }
4485 
4486 static int handle_bmc_rsp(struct ipmi_smi *intf,
4487 			  struct ipmi_smi_msg *msg)
4488 {
4489 	struct ipmi_recv_msg *recv_msg;
4490 	struct ipmi_system_interface_addr *smi_addr;
4491 
4492 	recv_msg = msg->recv_msg;
4493 	if (recv_msg == NULL) {
4494 		dev_warn(intf->si_dev,
4495 			 "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");
4496 		return 0;
4497 	}
4498 
4499 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
4500 	recv_msg->msgid = msg->msgid;
4501 	smi_addr = ((struct ipmi_system_interface_addr *)
4502 		    &recv_msg->addr);
4503 	smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4504 	smi_addr->channel = IPMI_BMC_CHANNEL;
4505 	smi_addr->lun = msg->rsp[0] & 3;
4506 	recv_msg->msg.netfn = msg->rsp[0] >> 2;
4507 	recv_msg->msg.cmd = msg->rsp[1];
4508 	memcpy(recv_msg->msg_data, &msg->rsp[2], msg->rsp_size - 2);
4509 	recv_msg->msg.data = recv_msg->msg_data;
4510 	recv_msg->msg.data_len = msg->rsp_size - 2;
4511 	deliver_local_response(intf, recv_msg);
4512 
4513 	return 0;
4514 }
4515 
4516 /*
4517  * Handle a received message.  Return 1 if the message should be requeued,
4518  * 0 if the message should be freed, or -1 if the message should not
4519  * be freed or requeued.
4520  */
4521 static int handle_one_recv_msg(struct ipmi_smi *intf,
4522 			       struct ipmi_smi_msg *msg)
4523 {
4524 	int requeue = 0;
4525 	int chan;
4526 	unsigned char cc;
4527 	bool is_cmd = !((msg->rsp[0] >> 2) & 1);
4528 
4529 	dev_dbg(intf->si_dev, "Recv: %*ph\n", msg->rsp_size, msg->rsp);
4530 
4531 	if (msg->rsp_size < 2) {
4532 		/* Message is too small to be correct. */
4533 		dev_warn_ratelimited(intf->si_dev,
4534 				     "BMC returned too small a message for netfn %x cmd %x, got %d bytes\n",
4535 				     (msg->data[0] >> 2) | 1,
4536 				     msg->data[1], msg->rsp_size);
4537 
4538 return_unspecified:
4539 		/* Generate an error response for the message. */
4540 		msg->rsp[0] = msg->data[0] | (1 << 2);
4541 		msg->rsp[1] = msg->data[1];
4542 		msg->rsp[2] = IPMI_ERR_UNSPECIFIED;
4543 		msg->rsp_size = 3;
4544 	} else if (msg->type == IPMI_SMI_MSG_TYPE_IPMB_DIRECT) {
4545 		/* commands must have at least 4 bytes, responses 5. */
4546 		if (is_cmd && (msg->rsp_size < 4)) {
4547 			ipmi_inc_stat(intf, invalid_commands);
4548 			goto out;
4549 		}
4550 		if (!is_cmd && (msg->rsp_size < 5)) {
4551 			ipmi_inc_stat(intf, invalid_ipmb_responses);
4552 			/* Construct a valid error response. */
4553 			msg->rsp[0] = msg->data[0] & 0xfc; /* NetFN */
4554 			msg->rsp[0] |= (1 << 2); /* Make it a response */
4555 			msg->rsp[0] |= msg->data[2] & 3; /* rqLUN */
4556 			msg->rsp[1] = msg->data[1]; /* Addr */
4557 			msg->rsp[2] = msg->data[2] & 0xfc; /* rqSeq */
4558 			msg->rsp[2] |= msg->data[0] & 0x3; /* rsLUN */
4559 			msg->rsp[3] = msg->data[3]; /* Cmd */
4560 			msg->rsp[4] = IPMI_ERR_UNSPECIFIED;
4561 			msg->rsp_size = 5;
4562 		}
4563 	} else if ((msg->data_size >= 2)
4564 	    && (msg->data[0] == (IPMI_NETFN_APP_REQUEST << 2))
4565 	    && (msg->data[1] == IPMI_SEND_MSG_CMD)
4566 	    && (msg->recv_msg == NULL)) {
4567 
4568 		if (intf->in_shutdown || intf->run_to_completion)
4569 			goto out;
4570 
4571 		/*
4572 		 * This is the local response to a command send, start
4573 		 * the timer for these.  The recv_msg will not be
4574 		 * NULL if this is a response send, and we will let
4575 		 * response sends just go through.
4576 		 */
4577 
4578 		/*
4579 		 * Check for errors, if we get certain errors (ones
4580 		 * that mean basically we can try again later), we
4581 		 * ignore them and start the timer.  Otherwise we
4582 		 * report the error immediately.
4583 		 */
4584 		if ((msg->rsp_size >= 3) && (msg->rsp[2] != 0)
4585 		    && (msg->rsp[2] != IPMI_NODE_BUSY_ERR)
4586 		    && (msg->rsp[2] != IPMI_LOST_ARBITRATION_ERR)
4587 		    && (msg->rsp[2] != IPMI_BUS_ERR)
4588 		    && (msg->rsp[2] != IPMI_NAK_ON_WRITE_ERR)) {
4589 			int ch = msg->rsp[3] & 0xf;
4590 			struct ipmi_channel *chans;
4591 
4592 			/* Got an error sending the message, handle it. */
4593 
4594 			chans = READ_ONCE(intf->channel_list)->c;
4595 			if ((chans[ch].medium == IPMI_CHANNEL_MEDIUM_8023LAN)
4596 			    || (chans[ch].medium == IPMI_CHANNEL_MEDIUM_ASYNC))
4597 				ipmi_inc_stat(intf, sent_lan_command_errs);
4598 			else
4599 				ipmi_inc_stat(intf, sent_ipmb_command_errs);
4600 			intf_err_seq(intf, msg->msgid, msg->rsp[2]);
4601 		} else
4602 			/* The message was sent, start the timer. */
4603 			intf_start_seq_timer(intf, msg->msgid);
4604 		requeue = 0;
4605 		goto out;
4606 	} else if (((msg->rsp[0] >> 2) != ((msg->data[0] >> 2) | 1))
4607 		   || (msg->rsp[1] != msg->data[1])) {
4608 		/*
4609 		 * The NetFN and Command in the response is not even
4610 		 * marginally correct.
4611 		 */
4612 		dev_warn_ratelimited(intf->si_dev,
4613 				     "BMC returned incorrect response, expected netfn %x cmd %x, got netfn %x cmd %x\n",
4614 				     (msg->data[0] >> 2) | 1, msg->data[1],
4615 				     msg->rsp[0] >> 2, msg->rsp[1]);
4616 
4617 		goto return_unspecified;
4618 	}
4619 
4620 	if (msg->type == IPMI_SMI_MSG_TYPE_IPMB_DIRECT) {
4621 		if ((msg->data[0] >> 2) & 1) {
4622 			/* It's a response to a sent response. */
4623 			chan = 0;
4624 			cc = msg->rsp[4];
4625 			goto process_response_response;
4626 		}
4627 		if (is_cmd)
4628 			requeue = handle_ipmb_direct_rcv_cmd(intf, msg);
4629 		else
4630 			requeue = handle_ipmb_direct_rcv_rsp(intf, msg);
4631 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4632 		   && (msg->rsp[1] == IPMI_SEND_MSG_CMD)
4633 		   && (msg->recv_msg != NULL)) {
4634 		/*
4635 		 * It's a response to a response we sent.  For this we
4636 		 * deliver a send message response to the user.
4637 		 */
4638 		struct ipmi_recv_msg *recv_msg;
4639 
4640 		if (intf->run_to_completion)
4641 			goto out;
4642 
4643 		chan = msg->data[2] & 0x0f;
4644 		if (chan >= IPMI_MAX_CHANNELS)
4645 			/* Invalid channel number */
4646 			goto out;
4647 		cc = msg->rsp[2];
4648 
4649 process_response_response:
4650 		recv_msg = msg->recv_msg;
4651 
4652 		requeue = 0;
4653 		if (!recv_msg)
4654 			goto out;
4655 
4656 		recv_msg->recv_type = IPMI_RESPONSE_RESPONSE_TYPE;
4657 		recv_msg->msg.data = recv_msg->msg_data;
4658 		recv_msg->msg_data[0] = cc;
4659 		recv_msg->msg.data_len = 1;
4660 		deliver_local_response(intf, recv_msg);
4661 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4662 		   && (msg->rsp[1] == IPMI_GET_MSG_CMD)) {
4663 		struct ipmi_channel   *chans;
4664 
4665 		if (intf->run_to_completion)
4666 			goto out;
4667 
4668 		/* It's from the receive queue. */
4669 		chan = msg->rsp[3] & 0xf;
4670 		if (chan >= IPMI_MAX_CHANNELS) {
4671 			/* Invalid channel number */
4672 			requeue = 0;
4673 			goto out;
4674 		}
4675 
4676 		/*
4677 		 * We need to make sure the channels have been initialized.
4678 		 * The channel_handler routine will set the "curr_channel"
4679 		 * equal to or greater than IPMI_MAX_CHANNELS when all the
4680 		 * channels for this interface have been initialized.
4681 		 */
4682 		if (!intf->channels_ready) {
4683 			requeue = 0; /* Throw the message away */
4684 			goto out;
4685 		}
4686 
4687 		chans = READ_ONCE(intf->channel_list)->c;
4688 
4689 		switch (chans[chan].medium) {
4690 		case IPMI_CHANNEL_MEDIUM_IPMB:
4691 			if (msg->rsp[4] & 0x04) {
4692 				/*
4693 				 * It's a response, so find the
4694 				 * requesting message and send it up.
4695 				 */
4696 				requeue = handle_ipmb_get_msg_rsp(intf, msg);
4697 			} else {
4698 				/*
4699 				 * It's a command to the SMS from some other
4700 				 * entity.  Handle that.
4701 				 */
4702 				requeue = handle_ipmb_get_msg_cmd(intf, msg);
4703 			}
4704 			break;
4705 
4706 		case IPMI_CHANNEL_MEDIUM_8023LAN:
4707 		case IPMI_CHANNEL_MEDIUM_ASYNC:
4708 			if (msg->rsp[6] & 0x04) {
4709 				/*
4710 				 * It's a response, so find the
4711 				 * requesting message and send it up.
4712 				 */
4713 				requeue = handle_lan_get_msg_rsp(intf, msg);
4714 			} else {
4715 				/*
4716 				 * It's a command to the SMS from some other
4717 				 * entity.  Handle that.
4718 				 */
4719 				requeue = handle_lan_get_msg_cmd(intf, msg);
4720 			}
4721 			break;
4722 
4723 		default:
4724 			/* Check for OEM Channels.  Clients had better
4725 			   register for these commands. */
4726 			if ((chans[chan].medium >= IPMI_CHANNEL_MEDIUM_OEM_MIN)
4727 			    && (chans[chan].medium
4728 				<= IPMI_CHANNEL_MEDIUM_OEM_MAX)) {
4729 				requeue = handle_oem_get_msg_cmd(intf, msg);
4730 			} else {
4731 				/*
4732 				 * We don't handle the channel type, so just
4733 				 * free the message.
4734 				 */
4735 				requeue = 0;
4736 			}
4737 		}
4738 
4739 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4740 		   && (msg->rsp[1] == IPMI_READ_EVENT_MSG_BUFFER_CMD)) {
4741 		/* It's an asynchronous event. */
4742 		if (intf->run_to_completion)
4743 			goto out;
4744 
4745 		requeue = handle_read_event_rsp(intf, msg);
4746 	} else {
4747 		/* It's a response from the local BMC. */
4748 		requeue = handle_bmc_rsp(intf, msg);
4749 	}
4750 
4751  out:
4752 	return requeue;
4753 }
4754 
4755 /*
4756  * If there are messages in the queue or pretimeouts, handle them.
4757  */
4758 static void handle_new_recv_msgs(struct ipmi_smi *intf)
4759 {
4760 	struct ipmi_smi_msg *smi_msg;
4761 	unsigned long flags = 0;
4762 	int rv;
4763 	int run_to_completion = READ_ONCE(intf->run_to_completion);
4764 
4765 	/* See if any waiting messages need to be processed. */
4766 	if (!run_to_completion)
4767 		spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4768 	while (!list_empty(&intf->waiting_rcv_msgs)) {
4769 		smi_msg = list_entry(intf->waiting_rcv_msgs.next,
4770 				     struct ipmi_smi_msg, link);
4771 		list_del(&smi_msg->link);
4772 		if (!run_to_completion)
4773 			spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
4774 					       flags);
4775 		rv = handle_one_recv_msg(intf, smi_msg);
4776 		if (!run_to_completion)
4777 			spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4778 		if (rv > 0) {
4779 			/*
4780 			 * To preserve message order, quit if we
4781 			 * can't handle a message.  Add the message
4782 			 * back at the head, this is safe because this
4783 			 * workqueue is the only thing that pulls the
4784 			 * messages.
4785 			 */
4786 			list_add(&smi_msg->link, &intf->waiting_rcv_msgs);
4787 			break;
4788 		} else {
4789 			if (rv == 0)
4790 				/* Message handled */
4791 				ipmi_free_smi_msg(smi_msg);
4792 			/* If rv < 0, fatal error, del but don't free. */
4793 		}
4794 	}
4795 	if (!run_to_completion)
4796 		spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock, flags);
4797 }
4798 
4799 static void smi_work(struct work_struct *t)
4800 {
4801 	unsigned long flags = 0; /* keep us warning-free. */
4802 	struct ipmi_smi *intf = from_work(intf, t, smi_work);
4803 	int run_to_completion = READ_ONCE(intf->run_to_completion);
4804 	struct ipmi_smi_msg *newmsg = NULL;
4805 	struct ipmi_recv_msg *msg, *msg2;
4806 	int cc;
4807 
4808 	/*
4809 	 * Start the next message if available.
4810 	 *
4811 	 * Do this here, not in the actual receiver, because we may deadlock
4812 	 * because the lower layer is allowed to hold locks while calling
4813 	 * message delivery.
4814 	 */
4815 restart:
4816 	if (!run_to_completion)
4817 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
4818 	if (intf->curr_msg == NULL && !intf->in_shutdown) {
4819 		struct list_head *entry = NULL;
4820 
4821 		/* Pick the high priority queue first. */
4822 		if (!list_empty(&intf->hp_xmit_msgs))
4823 			entry = intf->hp_xmit_msgs.next;
4824 		else if (!list_empty(&intf->xmit_msgs))
4825 			entry = intf->xmit_msgs.next;
4826 
4827 		if (entry) {
4828 			list_del(entry);
4829 			newmsg = list_entry(entry, struct ipmi_smi_msg, link);
4830 			intf->curr_msg = newmsg;
4831 		}
4832 	}
4833 	if (!run_to_completion)
4834 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
4835 
4836 	if (newmsg) {
4837 		cc = intf->handlers->sender(intf->send_info, newmsg);
4838 		if (cc) {
4839 			if (newmsg->recv_msg)
4840 				deliver_err_response(intf,
4841 						     newmsg->recv_msg, cc);
4842 			else
4843 				ipmi_free_smi_msg(newmsg);
4844 			goto restart;
4845 		}
4846 	}
4847 
4848 	handle_new_recv_msgs(intf);
4849 
4850 	/* Nothing below applies during panic time. */
4851 	if (run_to_completion)
4852 		return;
4853 
4854 	/*
4855 	 * If the pretimout count is non-zero, decrement one from it and
4856 	 * deliver pretimeouts to all the users.
4857 	 */
4858 	if (atomic_add_unless(&intf->watchdog_pretimeouts_to_deliver, -1, 0)) {
4859 		struct ipmi_user *user;
4860 
4861 		mutex_lock(&intf->users_mutex);
4862 		list_for_each_entry(user, &intf->users, link) {
4863 			if (user->handler->ipmi_watchdog_pretimeout)
4864 				user->handler->ipmi_watchdog_pretimeout(
4865 					user->handler_data);
4866 		}
4867 		mutex_unlock(&intf->users_mutex);
4868 	}
4869 
4870 	/*
4871 	 * Freeing the message can cause a user to be released, which
4872 	 * can then cause the interface to be freed.  Make sure that
4873 	 * doesn't happen until we are ready.
4874 	 */
4875 	kref_get(&intf->refcount);
4876 
4877 	mutex_lock(&intf->user_msgs_mutex);
4878 	list_for_each_entry_safe(msg, msg2, &intf->user_msgs, link) {
4879 		struct ipmi_user *user = msg->user;
4880 
4881 		list_del(&msg->link);
4882 
4883 		if (refcount_read(&user->destroyed) == 0)
4884 			ipmi_free_recv_msg(msg);
4885 		else
4886 			user->handler->ipmi_recv_hndl(msg, user->handler_data);
4887 	}
4888 	mutex_unlock(&intf->user_msgs_mutex);
4889 
4890 	kref_put(&intf->refcount, intf_free);
4891 }
4892 
4893 /* Handle a new message from the lower layer. */
4894 void ipmi_smi_msg_received(struct ipmi_smi *intf,
4895 			   struct ipmi_smi_msg *msg)
4896 {
4897 	unsigned long flags = 0; /* keep us warning-free. */
4898 	int run_to_completion = READ_ONCE(intf->run_to_completion);
4899 
4900 	/*
4901 	 * To preserve message order, we keep a queue and deliver from
4902 	 * a workqueue.
4903 	 */
4904 	if (!run_to_completion)
4905 		spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4906 	list_add_tail(&msg->link, &intf->waiting_rcv_msgs);
4907 	if (!run_to_completion)
4908 		spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
4909 				       flags);
4910 
4911 	if (!run_to_completion)
4912 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
4913 	/*
4914 	 * We can get an asynchronous event or receive message in addition
4915 	 * to commands we send.
4916 	 */
4917 	if (msg == intf->curr_msg)
4918 		intf->curr_msg = NULL;
4919 	if (!run_to_completion)
4920 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
4921 
4922 	if (run_to_completion)
4923 		smi_work(&intf->smi_work);
4924 	else
4925 		queue_work(system_wq, &intf->smi_work);
4926 }
4927 EXPORT_SYMBOL(ipmi_smi_msg_received);
4928 
4929 void ipmi_smi_watchdog_pretimeout(struct ipmi_smi *intf)
4930 {
4931 	if (intf->in_shutdown)
4932 		return;
4933 
4934 	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 1);
4935 	queue_work(system_wq, &intf->smi_work);
4936 }
4937 EXPORT_SYMBOL(ipmi_smi_watchdog_pretimeout);
4938 
4939 static struct ipmi_smi_msg *
4940 smi_from_recv_msg(struct ipmi_smi *intf, struct ipmi_recv_msg *recv_msg,
4941 		  unsigned char seq, long seqid)
4942 {
4943 	struct ipmi_smi_msg *smi_msg = ipmi_alloc_smi_msg();
4944 	if (!smi_msg)
4945 		/*
4946 		 * If we can't allocate the message, then just return, we
4947 		 * get 4 retries, so this should be ok.
4948 		 */
4949 		return NULL;
4950 
4951 	memcpy(smi_msg->data, recv_msg->msg.data, recv_msg->msg.data_len);
4952 	smi_msg->data_size = recv_msg->msg.data_len;
4953 	smi_msg->msgid = STORE_SEQ_IN_MSGID(seq, seqid);
4954 
4955 	dev_dbg(intf->si_dev, "Resend: %*ph\n",
4956 		smi_msg->data_size, smi_msg->data);
4957 
4958 	return smi_msg;
4959 }
4960 
4961 static void check_msg_timeout(struct ipmi_smi *intf, struct seq_table *ent,
4962 			      struct list_head *timeouts,
4963 			      unsigned long timeout_period,
4964 			      int slot, bool *need_timer)
4965 {
4966 	struct ipmi_recv_msg *msg;
4967 
4968 	if (intf->in_shutdown)
4969 		return;
4970 
4971 	if (!ent->inuse)
4972 		return;
4973 
4974 	if (timeout_period < ent->timeout) {
4975 		ent->timeout -= timeout_period;
4976 		*need_timer = true;
4977 		return;
4978 	}
4979 
4980 	if (ent->retries_left == 0) {
4981 		/* The message has used all its retries. */
4982 		ent->inuse = 0;
4983 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
4984 		msg = ent->recv_msg;
4985 		list_add_tail(&msg->link, timeouts);
4986 		if (ent->broadcast)
4987 			ipmi_inc_stat(intf, timed_out_ipmb_broadcasts);
4988 		else if (is_lan_addr(&ent->recv_msg->addr))
4989 			ipmi_inc_stat(intf, timed_out_lan_commands);
4990 		else
4991 			ipmi_inc_stat(intf, timed_out_ipmb_commands);
4992 	} else {
4993 		struct ipmi_smi_msg *smi_msg;
4994 		/* More retries, send again. */
4995 
4996 		*need_timer = true;
4997 
4998 		/*
4999 		 * Start with the max timer, set to normal timer after
5000 		 * the message is sent.
5001 		 */
5002 		ent->timeout = MAX_MSG_TIMEOUT;
5003 		ent->retries_left--;
5004 		smi_msg = smi_from_recv_msg(intf, ent->recv_msg, slot,
5005 					    ent->seqid);
5006 		if (!smi_msg) {
5007 			if (is_lan_addr(&ent->recv_msg->addr))
5008 				ipmi_inc_stat(intf,
5009 					      dropped_rexmit_lan_commands);
5010 			else
5011 				ipmi_inc_stat(intf,
5012 					      dropped_rexmit_ipmb_commands);
5013 			return;
5014 		}
5015 
5016 		mutex_unlock(&intf->seq_lock);
5017 
5018 		/*
5019 		 * Send the new message.  We send with a zero
5020 		 * priority.  It timed out, I doubt time is that
5021 		 * critical now, and high priority messages are really
5022 		 * only for messages to the local MC, which don't get
5023 		 * resent.
5024 		 */
5025 		if (intf->handlers) {
5026 			if (is_lan_addr(&ent->recv_msg->addr))
5027 				ipmi_inc_stat(intf,
5028 					      retransmitted_lan_commands);
5029 			else
5030 				ipmi_inc_stat(intf,
5031 					      retransmitted_ipmb_commands);
5032 
5033 			smi_send(intf, intf->handlers, smi_msg, 0);
5034 		} else
5035 			ipmi_free_smi_msg(smi_msg);
5036 
5037 		mutex_lock(&intf->seq_lock);
5038 	}
5039 }
5040 
5041 static bool ipmi_timeout_handler(struct ipmi_smi *intf,
5042 				 unsigned long timeout_period)
5043 {
5044 	struct list_head     timeouts;
5045 	struct ipmi_recv_msg *msg, *msg2;
5046 	unsigned long        flags;
5047 	int                  i;
5048 	bool                 need_timer = false;
5049 
5050 	if (!intf->bmc_registered) {
5051 		kref_get(&intf->refcount);
5052 		if (!schedule_work(&intf->bmc_reg_work)) {
5053 			kref_put(&intf->refcount, intf_free);
5054 			need_timer = true;
5055 		}
5056 	}
5057 
5058 	/*
5059 	 * Go through the seq table and find any messages that
5060 	 * have timed out, putting them in the timeouts
5061 	 * list.
5062 	 */
5063 	INIT_LIST_HEAD(&timeouts);
5064 	mutex_lock(&intf->seq_lock);
5065 	if (intf->ipmb_maintenance_mode_timeout) {
5066 		if (intf->ipmb_maintenance_mode_timeout <= timeout_period)
5067 			intf->ipmb_maintenance_mode_timeout = 0;
5068 		else
5069 			intf->ipmb_maintenance_mode_timeout -= timeout_period;
5070 	}
5071 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++)
5072 		check_msg_timeout(intf, &intf->seq_table[i],
5073 				  &timeouts, timeout_period, i,
5074 				  &need_timer);
5075 	mutex_unlock(&intf->seq_lock);
5076 
5077 	list_for_each_entry_safe(msg, msg2, &timeouts, link)
5078 		deliver_err_response(intf, msg, IPMI_TIMEOUT_COMPLETION_CODE);
5079 
5080 	/*
5081 	 * Maintenance mode handling.  Check the timeout
5082 	 * optimistically before we claim the lock.  It may
5083 	 * mean a timeout gets missed occasionally, but that
5084 	 * only means the timeout gets extended by one period
5085 	 * in that case.  No big deal, and it avoids the lock
5086 	 * most of the time.
5087 	 */
5088 	if (intf->auto_maintenance_timeout > 0) {
5089 		spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
5090 		if (intf->auto_maintenance_timeout > 0) {
5091 			intf->auto_maintenance_timeout
5092 				-= timeout_period;
5093 			if (!intf->maintenance_mode
5094 			    && (intf->auto_maintenance_timeout <= 0)) {
5095 				intf->maintenance_mode_state =
5096 					IPMI_MAINTENANCE_MODE_STATE_OFF;
5097 				intf->auto_maintenance_timeout = 0;
5098 				maintenance_mode_update(intf);
5099 			}
5100 		}
5101 		spin_unlock_irqrestore(&intf->maintenance_mode_lock,
5102 				       flags);
5103 	}
5104 
5105 	queue_work(system_wq, &intf->smi_work);
5106 
5107 	return need_timer;
5108 }
5109 
5110 static void ipmi_request_event(struct ipmi_smi *intf)
5111 {
5112 	/* No event requests when in maintenance mode. */
5113 	if (intf->maintenance_mode_state)
5114 		return;
5115 
5116 	if (!intf->in_shutdown)
5117 		intf->handlers->request_events(intf->send_info);
5118 }
5119 
5120 static atomic_t stop_operation;
5121 
5122 static void ipmi_timeout_work(struct work_struct *work)
5123 {
5124 	if (atomic_read(&stop_operation))
5125 		return;
5126 
5127 	struct ipmi_smi *intf;
5128 	bool need_timer = false;
5129 
5130 	if (atomic_read(&stop_operation))
5131 		return;
5132 
5133 	mutex_lock(&ipmi_interfaces_mutex);
5134 	list_for_each_entry(intf, &ipmi_interfaces, link) {
5135 		if (atomic_read(&intf->event_waiters)) {
5136 			intf->ticks_to_req_ev--;
5137 			if (intf->ticks_to_req_ev == 0) {
5138 				ipmi_request_event(intf);
5139 				intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
5140 			}
5141 			need_timer = true;
5142 		}
5143 		if (intf->maintenance_mode_state)
5144 			need_timer = true;
5145 
5146 		need_timer |= ipmi_timeout_handler(intf, IPMI_TIMEOUT_TIME);
5147 	}
5148 	mutex_unlock(&ipmi_interfaces_mutex);
5149 
5150 	if (need_timer)
5151 		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
5152 }
5153 
5154 static DECLARE_WORK(ipmi_timer_work, ipmi_timeout_work);
5155 
5156 static void ipmi_timeout(struct timer_list *unused)
5157 {
5158 	if (atomic_read(&stop_operation))
5159 		return;
5160 
5161 	queue_work(system_wq, &ipmi_timer_work);
5162 }
5163 
5164 static void need_waiter(struct ipmi_smi *intf)
5165 {
5166 	/* Racy, but worst case we start the timer twice. */
5167 	if (!timer_pending(&ipmi_timer))
5168 		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
5169 }
5170 
5171 static atomic_t smi_msg_inuse_count = ATOMIC_INIT(0);
5172 static atomic_t recv_msg_inuse_count = ATOMIC_INIT(0);
5173 
5174 static void free_smi_msg(struct ipmi_smi_msg *msg)
5175 {
5176 	atomic_dec(&smi_msg_inuse_count);
5177 	/* Try to keep as much stuff out of the panic path as possible. */
5178 	if (!oops_in_progress)
5179 		kfree(msg);
5180 }
5181 
5182 struct ipmi_smi_msg *ipmi_alloc_smi_msg(void)
5183 {
5184 	struct ipmi_smi_msg *rv;
5185 	rv = kmalloc(sizeof(struct ipmi_smi_msg), GFP_ATOMIC);
5186 	if (rv) {
5187 		rv->done = free_smi_msg;
5188 		rv->recv_msg = NULL;
5189 		rv->type = IPMI_SMI_MSG_TYPE_NORMAL;
5190 		atomic_inc(&smi_msg_inuse_count);
5191 	}
5192 	return rv;
5193 }
5194 EXPORT_SYMBOL(ipmi_alloc_smi_msg);
5195 
5196 static void free_recv_msg(struct ipmi_recv_msg *msg)
5197 {
5198 	atomic_dec(&recv_msg_inuse_count);
5199 	/* Try to keep as much stuff out of the panic path as possible. */
5200 	if (!oops_in_progress)
5201 		kfree(msg);
5202 }
5203 
5204 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(struct ipmi_user *user)
5205 {
5206 	struct ipmi_recv_msg *rv;
5207 
5208 	if (user) {
5209 		if (atomic_add_return(1, &user->nr_msgs) > max_msgs_per_user) {
5210 			atomic_dec(&user->nr_msgs);
5211 			return ERR_PTR(-EBUSY);
5212 		}
5213 	}
5214 
5215 	rv = kmalloc(sizeof(struct ipmi_recv_msg), GFP_ATOMIC);
5216 	if (!rv) {
5217 		if (user)
5218 			atomic_dec(&user->nr_msgs);
5219 		return ERR_PTR(-ENOMEM);
5220 	}
5221 
5222 	rv->user = user;
5223 	rv->done = free_recv_msg;
5224 	if (user)
5225 		kref_get(&user->refcount);
5226 	atomic_inc(&recv_msg_inuse_count);
5227 	return rv;
5228 }
5229 
5230 void ipmi_free_recv_msg(struct ipmi_recv_msg *msg)
5231 {
5232 	if (msg->user && !oops_in_progress) {
5233 		atomic_dec(&msg->user->nr_msgs);
5234 		kref_put(&msg->user->refcount, free_ipmi_user);
5235 	}
5236 	msg->done(msg);
5237 }
5238 EXPORT_SYMBOL(ipmi_free_recv_msg);
5239 
5240 static void ipmi_set_recv_msg_user(struct ipmi_recv_msg *msg,
5241 				   struct ipmi_user *user)
5242 {
5243 	WARN_ON_ONCE(msg->user); /* User should not be set. */
5244 	msg->user = user;
5245 	atomic_inc(&user->nr_msgs);
5246 	kref_get(&user->refcount);
5247 }
5248 
5249 static atomic_t panic_done_count = ATOMIC_INIT(0);
5250 
5251 static void dummy_smi_done_handler(struct ipmi_smi_msg *msg)
5252 {
5253 	atomic_dec(&panic_done_count);
5254 }
5255 
5256 static void dummy_recv_done_handler(struct ipmi_recv_msg *msg)
5257 {
5258 	atomic_dec(&panic_done_count);
5259 }
5260 
5261 /*
5262  * Inside a panic, send a message and wait for a response.
5263  */
5264 static void _ipmi_panic_request_and_wait(struct ipmi_smi *intf,
5265 					 struct ipmi_addr *addr,
5266 					 struct kernel_ipmi_msg *msg)
5267 {
5268 	struct ipmi_smi_msg  smi_msg;
5269 	struct ipmi_recv_msg recv_msg;
5270 	int rv;
5271 
5272 	smi_msg.done = dummy_smi_done_handler;
5273 	recv_msg.done = dummy_recv_done_handler;
5274 	atomic_add(2, &panic_done_count);
5275 	rv = i_ipmi_request(NULL,
5276 			    intf,
5277 			    addr,
5278 			    0,
5279 			    msg,
5280 			    intf,
5281 			    &smi_msg,
5282 			    &recv_msg,
5283 			    0,
5284 			    intf->addrinfo[0].address,
5285 			    intf->addrinfo[0].lun,
5286 			    0, 1); /* Don't retry, and don't wait. */
5287 	if (rv)
5288 		atomic_sub(2, &panic_done_count);
5289 	else if (intf->handlers->flush_messages)
5290 		intf->handlers->flush_messages(intf->send_info);
5291 
5292 	while (atomic_read(&panic_done_count) != 0)
5293 		ipmi_poll(intf);
5294 }
5295 
5296 void ipmi_panic_request_and_wait(struct ipmi_user *user,
5297 				 struct ipmi_addr *addr,
5298 				 struct kernel_ipmi_msg *msg)
5299 {
5300 	user->intf->run_to_completion = 1;
5301 	_ipmi_panic_request_and_wait(user->intf, addr, msg);
5302 }
5303 EXPORT_SYMBOL(ipmi_panic_request_and_wait);
5304 
5305 static void event_receiver_fetcher(struct ipmi_smi *intf,
5306 				   struct ipmi_recv_msg *msg)
5307 {
5308 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
5309 	    && (msg->msg.netfn == IPMI_NETFN_SENSOR_EVENT_RESPONSE)
5310 	    && (msg->msg.cmd == IPMI_GET_EVENT_RECEIVER_CMD)
5311 	    && (msg->msg.data[0] == IPMI_CC_NO_ERROR)) {
5312 		/* A get event receiver command, save it. */
5313 		intf->event_receiver = msg->msg.data[1];
5314 		intf->event_receiver_lun = msg->msg.data[2] & 0x3;
5315 	}
5316 }
5317 
5318 static void device_id_fetcher(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
5319 {
5320 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
5321 	    && (msg->msg.netfn == IPMI_NETFN_APP_RESPONSE)
5322 	    && (msg->msg.cmd == IPMI_GET_DEVICE_ID_CMD)
5323 	    && (msg->msg.data[0] == IPMI_CC_NO_ERROR)) {
5324 		/*
5325 		 * A get device id command, save if we are an event
5326 		 * receiver or generator.
5327 		 */
5328 		intf->local_sel_device = (msg->msg.data[6] >> 2) & 1;
5329 		intf->local_event_generator = (msg->msg.data[6] >> 5) & 1;
5330 	}
5331 }
5332 
5333 static void send_panic_events(struct ipmi_smi *intf, char *str)
5334 {
5335 	struct kernel_ipmi_msg msg;
5336 	unsigned char data[16];
5337 	struct ipmi_system_interface_addr *si;
5338 	struct ipmi_addr addr;
5339 	char *p = str;
5340 	struct ipmi_ipmb_addr *ipmb;
5341 	int j;
5342 
5343 	if (ipmi_send_panic_event == IPMI_SEND_PANIC_EVENT_NONE)
5344 		return;
5345 
5346 	si = (struct ipmi_system_interface_addr *) &addr;
5347 	si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
5348 	si->channel = IPMI_BMC_CHANNEL;
5349 	si->lun = 0;
5350 
5351 	/* Fill in an event telling that we have failed. */
5352 	msg.netfn = 0x04; /* Sensor or Event. */
5353 	msg.cmd = 2; /* Platform event command. */
5354 	msg.data = data;
5355 	msg.data_len = 8;
5356 	data[0] = 0x41; /* Kernel generator ID, IPMI table 5-4 */
5357 	data[1] = 0x03; /* This is for IPMI 1.0. */
5358 	data[2] = 0x20; /* OS Critical Stop, IPMI table 36-3 */
5359 	data[4] = 0x6f; /* Sensor specific, IPMI table 36-1 */
5360 	data[5] = 0xa1; /* Runtime stop OEM bytes 2 & 3. */
5361 
5362 	/*
5363 	 * Put a few breadcrumbs in.  Hopefully later we can add more things
5364 	 * to make the panic events more useful.
5365 	 */
5366 	if (str) {
5367 		data[3] = str[0];
5368 		data[6] = str[1];
5369 		data[7] = str[2];
5370 	}
5371 
5372 	/* Send the event announcing the panic. */
5373 	_ipmi_panic_request_and_wait(intf, &addr, &msg);
5374 
5375 	/*
5376 	 * On every interface, dump a bunch of OEM event holding the
5377 	 * string.
5378 	 */
5379 	if (ipmi_send_panic_event != IPMI_SEND_PANIC_EVENT_STRING || !str)
5380 		return;
5381 
5382 	/*
5383 	 * intf_num is used as an marker to tell if the
5384 	 * interface is valid.  Thus we need a read barrier to
5385 	 * make sure data fetched before checking intf_num
5386 	 * won't be used.
5387 	 */
5388 	smp_rmb();
5389 
5390 	/*
5391 	 * First job here is to figure out where to send the
5392 	 * OEM events.  There's no way in IPMI to send OEM
5393 	 * events using an event send command, so we have to
5394 	 * find the SEL to put them in and stick them in
5395 	 * there.
5396 	 */
5397 
5398 	/* Get capabilities from the get device id. */
5399 	intf->local_sel_device = 0;
5400 	intf->local_event_generator = 0;
5401 	intf->event_receiver = 0;
5402 
5403 	/* Request the device info from the local MC. */
5404 	msg.netfn = IPMI_NETFN_APP_REQUEST;
5405 	msg.cmd = IPMI_GET_DEVICE_ID_CMD;
5406 	msg.data = NULL;
5407 	msg.data_len = 0;
5408 	intf->null_user_handler = device_id_fetcher;
5409 	_ipmi_panic_request_and_wait(intf, &addr, &msg);
5410 
5411 	if (intf->local_event_generator) {
5412 		/* Request the event receiver from the local MC. */
5413 		msg.netfn = IPMI_NETFN_SENSOR_EVENT_REQUEST;
5414 		msg.cmd = IPMI_GET_EVENT_RECEIVER_CMD;
5415 		msg.data = NULL;
5416 		msg.data_len = 0;
5417 		intf->null_user_handler = event_receiver_fetcher;
5418 		_ipmi_panic_request_and_wait(intf, &addr, &msg);
5419 	}
5420 	intf->null_user_handler = NULL;
5421 
5422 	/*
5423 	 * Validate the event receiver.  The low bit must not
5424 	 * be 1 (it must be a valid IPMB address), it cannot
5425 	 * be zero, and it must not be my address.
5426 	 */
5427 	if (((intf->event_receiver & 1) == 0)
5428 	    && (intf->event_receiver != 0)
5429 	    && (intf->event_receiver != intf->addrinfo[0].address)) {
5430 		/*
5431 		 * The event receiver is valid, send an IPMB
5432 		 * message.
5433 		 */
5434 		ipmb = (struct ipmi_ipmb_addr *) &addr;
5435 		ipmb->addr_type = IPMI_IPMB_ADDR_TYPE;
5436 		ipmb->channel = 0; /* FIXME - is this right? */
5437 		ipmb->lun = intf->event_receiver_lun;
5438 		ipmb->slave_addr = intf->event_receiver;
5439 	} else if (intf->local_sel_device) {
5440 		/*
5441 		 * The event receiver was not valid (or was
5442 		 * me), but I am an SEL device, just dump it
5443 		 * in my SEL.
5444 		 */
5445 		si = (struct ipmi_system_interface_addr *) &addr;
5446 		si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
5447 		si->channel = IPMI_BMC_CHANNEL;
5448 		si->lun = 0;
5449 	} else
5450 		return; /* No where to send the event. */
5451 
5452 	msg.netfn = IPMI_NETFN_STORAGE_REQUEST; /* Storage. */
5453 	msg.cmd = IPMI_ADD_SEL_ENTRY_CMD;
5454 	msg.data = data;
5455 	msg.data_len = 16;
5456 
5457 	j = 0;
5458 	while (*p) {
5459 		int size = strnlen(p, 11);
5460 
5461 		data[0] = 0;
5462 		data[1] = 0;
5463 		data[2] = 0xf0; /* OEM event without timestamp. */
5464 		data[3] = intf->addrinfo[0].address;
5465 		data[4] = j++; /* sequence # */
5466 
5467 		memcpy_and_pad(data+5, 11, p, size, '\0');
5468 		p += size;
5469 
5470 		_ipmi_panic_request_and_wait(intf, &addr, &msg);
5471 	}
5472 }
5473 
5474 static int has_panicked;
5475 
5476 static int panic_event(struct notifier_block *this,
5477 		       unsigned long         event,
5478 		       void                  *ptr)
5479 {
5480 	struct ipmi_smi *intf;
5481 	struct ipmi_user *user;
5482 
5483 	if (has_panicked)
5484 		return NOTIFY_DONE;
5485 	has_panicked = 1;
5486 
5487 	/* For every registered interface, set it to run to completion. */
5488 	list_for_each_entry(intf, &ipmi_interfaces, link) {
5489 		if (!intf->handlers || intf->intf_num == -1)
5490 			/* Interface is not ready. */
5491 			continue;
5492 
5493 		if (!intf->handlers->poll)
5494 			continue;
5495 
5496 		/*
5497 		 * If we were interrupted while locking xmit_msgs_lock or
5498 		 * waiting_rcv_msgs_lock, the corresponding list may be
5499 		 * corrupted.  In this case, drop items on the list for
5500 		 * the safety.
5501 		 */
5502 		if (!spin_trylock(&intf->xmit_msgs_lock)) {
5503 			INIT_LIST_HEAD(&intf->xmit_msgs);
5504 			INIT_LIST_HEAD(&intf->hp_xmit_msgs);
5505 		} else
5506 			spin_unlock(&intf->xmit_msgs_lock);
5507 
5508 		if (!spin_trylock(&intf->waiting_rcv_msgs_lock))
5509 			INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
5510 		else
5511 			spin_unlock(&intf->waiting_rcv_msgs_lock);
5512 
5513 		intf->run_to_completion = 1;
5514 		if (intf->handlers->set_run_to_completion)
5515 			intf->handlers->set_run_to_completion(intf->send_info,
5516 							      1);
5517 
5518 		list_for_each_entry(user, &intf->users, link) {
5519 			if (user->handler->ipmi_panic_handler)
5520 				user->handler->ipmi_panic_handler(
5521 					user->handler_data);
5522 		}
5523 
5524 		send_panic_events(intf, ptr);
5525 	}
5526 
5527 	return NOTIFY_DONE;
5528 }
5529 
5530 /* Must be called with ipmi_interfaces_mutex held. */
5531 static int ipmi_register_driver(void)
5532 {
5533 	int rv;
5534 
5535 	if (drvregistered)
5536 		return 0;
5537 
5538 	rv = driver_register(&ipmidriver.driver);
5539 	if (rv)
5540 		pr_err("Could not register IPMI driver\n");
5541 	else
5542 		drvregistered = true;
5543 	return rv;
5544 }
5545 
5546 static struct notifier_block panic_block = {
5547 	.notifier_call	= panic_event,
5548 	.next		= NULL,
5549 	.priority	= 200	/* priority: INT_MAX >= x >= 0 */
5550 };
5551 
5552 static int ipmi_init_msghandler(void)
5553 {
5554 	int rv;
5555 
5556 	mutex_lock(&ipmi_interfaces_mutex);
5557 	rv = ipmi_register_driver();
5558 	if (rv)
5559 		goto out;
5560 	if (initialized)
5561 		goto out;
5562 
5563 	bmc_remove_work_wq = create_singlethread_workqueue("ipmi-msghandler-remove-wq");
5564 	if (!bmc_remove_work_wq) {
5565 		pr_err("unable to create ipmi-msghandler-remove-wq workqueue");
5566 		rv = -ENOMEM;
5567 		goto out;
5568 	}
5569 
5570 	timer_setup(&ipmi_timer, ipmi_timeout, 0);
5571 	mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
5572 
5573 	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
5574 
5575 	initialized = true;
5576 
5577 out:
5578 	mutex_unlock(&ipmi_interfaces_mutex);
5579 	return rv;
5580 }
5581 
5582 static int __init ipmi_init_msghandler_mod(void)
5583 {
5584 	int rv;
5585 
5586 	pr_info("version " IPMI_DRIVER_VERSION "\n");
5587 
5588 	mutex_lock(&ipmi_interfaces_mutex);
5589 	rv = ipmi_register_driver();
5590 	mutex_unlock(&ipmi_interfaces_mutex);
5591 
5592 	return rv;
5593 }
5594 
5595 static void __exit cleanup_ipmi(void)
5596 {
5597 	int count;
5598 
5599 	if (initialized) {
5600 		destroy_workqueue(bmc_remove_work_wq);
5601 
5602 		atomic_notifier_chain_unregister(&panic_notifier_list,
5603 						 &panic_block);
5604 
5605 		/*
5606 		 * This can't be called if any interfaces exist, so no worry
5607 		 * about shutting down the interfaces.
5608 		 */
5609 
5610 		/*
5611 		 * Tell the timer to stop, then wait for it to stop.  This
5612 		 * avoids problems with race conditions removing the timer
5613 		 * here.
5614 		 */
5615 		atomic_set(&stop_operation, 1);
5616 		timer_delete_sync(&ipmi_timer);
5617 		cancel_work_sync(&ipmi_timer_work);
5618 
5619 		initialized = false;
5620 
5621 		/* Check for buffer leaks. */
5622 		count = atomic_read(&smi_msg_inuse_count);
5623 		if (count != 0)
5624 			pr_warn("SMI message count %d at exit\n", count);
5625 		count = atomic_read(&recv_msg_inuse_count);
5626 		if (count != 0)
5627 			pr_warn("recv message count %d at exit\n", count);
5628 	}
5629 	if (drvregistered)
5630 		driver_unregister(&ipmidriver.driver);
5631 }
5632 module_exit(cleanup_ipmi);
5633 
5634 module_init(ipmi_init_msghandler_mod);
5635 MODULE_LICENSE("GPL");
5636 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
5637 MODULE_DESCRIPTION("Incoming and outgoing message routing for an IPMI interface.");
5638 MODULE_VERSION(IPMI_DRIVER_VERSION);
5639 MODULE_SOFTDEP("post: ipmi_devintf");
5640