xref: /openbmc/linux/drivers/char/ipmi/ipmi_msghandler.c (revision f97cee494dc92395a668445bcd24d34c89f4ff8c)
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) "%s" fmt, "IPMI message handler: "
15 #define dev_fmt pr_fmt
16 
17 #include <linux/module.h>
18 #include <linux/errno.h>
19 #include <linux/poll.h>
20 #include <linux/sched.h>
21 #include <linux/seq_file.h>
22 #include <linux/spinlock.h>
23 #include <linux/mutex.h>
24 #include <linux/slab.h>
25 #include <linux/ipmi.h>
26 #include <linux/ipmi_smi.h>
27 #include <linux/notifier.h>
28 #include <linux/init.h>
29 #include <linux/proc_fs.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 
38 #define IPMI_DRIVER_VERSION "39.2"
39 
40 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void);
41 static int ipmi_init_msghandler(void);
42 static void smi_recv_tasklet(unsigned long);
43 static void handle_new_recv_msgs(struct ipmi_smi *intf);
44 static void need_waiter(struct ipmi_smi *intf);
45 static int handle_one_recv_msg(struct ipmi_smi *intf,
46 			       struct ipmi_smi_msg *msg);
47 
48 static bool initialized;
49 static bool drvregistered;
50 
51 enum ipmi_panic_event_op {
52 	IPMI_SEND_PANIC_EVENT_NONE,
53 	IPMI_SEND_PANIC_EVENT,
54 	IPMI_SEND_PANIC_EVENT_STRING
55 };
56 #ifdef CONFIG_IPMI_PANIC_STRING
57 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT_STRING
58 #elif defined(CONFIG_IPMI_PANIC_EVENT)
59 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT
60 #else
61 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT_NONE
62 #endif
63 static enum ipmi_panic_event_op ipmi_send_panic_event = IPMI_PANIC_DEFAULT;
64 
65 static int panic_op_write_handler(const char *val,
66 				  const struct kernel_param *kp)
67 {
68 	char valcp[16];
69 	char *s;
70 
71 	strncpy(valcp, val, 15);
72 	valcp[15] = '\0';
73 
74 	s = strstrip(valcp);
75 
76 	if (strcmp(s, "none") == 0)
77 		ipmi_send_panic_event = IPMI_SEND_PANIC_EVENT_NONE;
78 	else if (strcmp(s, "event") == 0)
79 		ipmi_send_panic_event = IPMI_SEND_PANIC_EVENT;
80 	else if (strcmp(s, "string") == 0)
81 		ipmi_send_panic_event = IPMI_SEND_PANIC_EVENT_STRING;
82 	else
83 		return -EINVAL;
84 
85 	return 0;
86 }
87 
88 static int panic_op_read_handler(char *buffer, const struct kernel_param *kp)
89 {
90 	switch (ipmi_send_panic_event) {
91 	case IPMI_SEND_PANIC_EVENT_NONE:
92 		strcpy(buffer, "none");
93 		break;
94 
95 	case IPMI_SEND_PANIC_EVENT:
96 		strcpy(buffer, "event");
97 		break;
98 
99 	case IPMI_SEND_PANIC_EVENT_STRING:
100 		strcpy(buffer, "string");
101 		break;
102 
103 	default:
104 		strcpy(buffer, "???");
105 		break;
106 	}
107 
108 	return strlen(buffer);
109 }
110 
111 static const struct kernel_param_ops panic_op_ops = {
112 	.set = panic_op_write_handler,
113 	.get = panic_op_read_handler
114 };
115 module_param_cb(panic_op, &panic_op_ops, NULL, 0600);
116 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.");
117 
118 
119 #define MAX_EVENTS_IN_QUEUE	25
120 
121 /* Remain in auto-maintenance mode for this amount of time (in ms). */
122 static unsigned long maintenance_mode_timeout_ms = 30000;
123 module_param(maintenance_mode_timeout_ms, ulong, 0644);
124 MODULE_PARM_DESC(maintenance_mode_timeout_ms,
125 		 "The time (milliseconds) after the last maintenance message that the connection stays in maintenance mode.");
126 
127 /*
128  * Don't let a message sit in a queue forever, always time it with at lest
129  * the max message timer.  This is in milliseconds.
130  */
131 #define MAX_MSG_TIMEOUT		60000
132 
133 /*
134  * Timeout times below are in milliseconds, and are done off a 1
135  * second timer.  So setting the value to 1000 would mean anything
136  * between 0 and 1000ms.  So really the only reasonable minimum
137  * setting it 2000ms, which is between 1 and 2 seconds.
138  */
139 
140 /* The default timeout for message retries. */
141 static unsigned long default_retry_ms = 2000;
142 module_param(default_retry_ms, ulong, 0644);
143 MODULE_PARM_DESC(default_retry_ms,
144 		 "The time (milliseconds) between retry sends");
145 
146 /* The default timeout for maintenance mode message retries. */
147 static unsigned long default_maintenance_retry_ms = 3000;
148 module_param(default_maintenance_retry_ms, ulong, 0644);
149 MODULE_PARM_DESC(default_maintenance_retry_ms,
150 		 "The time (milliseconds) between retry sends in maintenance mode");
151 
152 /* The default maximum number of retries */
153 static unsigned int default_max_retries = 4;
154 module_param(default_max_retries, uint, 0644);
155 MODULE_PARM_DESC(default_max_retries,
156 		 "The time (milliseconds) between retry sends in maintenance mode");
157 
158 /* Call every ~1000 ms. */
159 #define IPMI_TIMEOUT_TIME	1000
160 
161 /* How many jiffies does it take to get to the timeout time. */
162 #define IPMI_TIMEOUT_JIFFIES	((IPMI_TIMEOUT_TIME * HZ) / 1000)
163 
164 /*
165  * Request events from the queue every second (this is the number of
166  * IPMI_TIMEOUT_TIMES between event requests).  Hopefully, in the
167  * future, IPMI will add a way to know immediately if an event is in
168  * the queue and this silliness can go away.
169  */
170 #define IPMI_REQUEST_EV_TIME	(1000 / (IPMI_TIMEOUT_TIME))
171 
172 /* How long should we cache dynamic device IDs? */
173 #define IPMI_DYN_DEV_ID_EXPIRY	(10 * HZ)
174 
175 /*
176  * The main "user" data structure.
177  */
178 struct ipmi_user {
179 	struct list_head link;
180 
181 	/*
182 	 * Set to NULL when the user is destroyed, a pointer to myself
183 	 * so srcu_dereference can be used on it.
184 	 */
185 	struct ipmi_user *self;
186 	struct srcu_struct release_barrier;
187 
188 	struct kref refcount;
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 	/* Free must run in process context for RCU cleanup. */
201 	struct work_struct remove_work;
202 };
203 
204 static struct ipmi_user *acquire_ipmi_user(struct ipmi_user *user, int *index)
205 	__acquires(user->release_barrier)
206 {
207 	struct ipmi_user *ruser;
208 
209 	*index = srcu_read_lock(&user->release_barrier);
210 	ruser = srcu_dereference(user->self, &user->release_barrier);
211 	if (!ruser)
212 		srcu_read_unlock(&user->release_barrier, *index);
213 	return ruser;
214 }
215 
216 static void release_ipmi_user(struct ipmi_user *user, int index)
217 {
218 	srcu_read_unlock(&user->release_barrier, index);
219 }
220 
221 struct cmd_rcvr {
222 	struct list_head link;
223 
224 	struct ipmi_user *user;
225 	unsigned char netfn;
226 	unsigned char cmd;
227 	unsigned int  chans;
228 
229 	/*
230 	 * This is used to form a linked lised during mass deletion.
231 	 * Since this is in an RCU list, we cannot use the link above
232 	 * or change any data until the RCU period completes.  So we
233 	 * use this next variable during mass deletion so we can have
234 	 * a list and don't have to wait and restart the search on
235 	 * every individual deletion of a command.
236 	 */
237 	struct cmd_rcvr *next;
238 };
239 
240 struct seq_table {
241 	unsigned int         inuse : 1;
242 	unsigned int         broadcast : 1;
243 
244 	unsigned long        timeout;
245 	unsigned long        orig_timeout;
246 	unsigned int         retries_left;
247 
248 	/*
249 	 * To verify on an incoming send message response that this is
250 	 * the message that the response is for, we keep a sequence id
251 	 * and increment it every time we send a message.
252 	 */
253 	long                 seqid;
254 
255 	/*
256 	 * This is held so we can properly respond to the message on a
257 	 * timeout, and it is used to hold the temporary data for
258 	 * retransmission, too.
259 	 */
260 	struct ipmi_recv_msg *recv_msg;
261 };
262 
263 /*
264  * Store the information in a msgid (long) to allow us to find a
265  * sequence table entry from the msgid.
266  */
267 #define STORE_SEQ_IN_MSGID(seq, seqid) \
268 	((((seq) & 0x3f) << 26) | ((seqid) & 0x3ffffff))
269 
270 #define GET_SEQ_FROM_MSGID(msgid, seq, seqid) \
271 	do {								\
272 		seq = (((msgid) >> 26) & 0x3f);				\
273 		seqid = ((msgid) & 0x3ffffff);				\
274 	} while (0)
275 
276 #define NEXT_SEQID(seqid) (((seqid) + 1) & 0x3ffffff)
277 
278 #define IPMI_MAX_CHANNELS       16
279 struct ipmi_channel {
280 	unsigned char medium;
281 	unsigned char protocol;
282 };
283 
284 struct ipmi_channel_set {
285 	struct ipmi_channel c[IPMI_MAX_CHANNELS];
286 };
287 
288 struct ipmi_my_addrinfo {
289 	/*
290 	 * My slave address.  This is initialized to IPMI_BMC_SLAVE_ADDR,
291 	 * but may be changed by the user.
292 	 */
293 	unsigned char address;
294 
295 	/*
296 	 * My LUN.  This should generally stay the SMS LUN, but just in
297 	 * case...
298 	 */
299 	unsigned char lun;
300 };
301 
302 /*
303  * Note that the product id, manufacturer id, guid, and device id are
304  * immutable in this structure, so dyn_mutex is not required for
305  * accessing those.  If those change on a BMC, a new BMC is allocated.
306  */
307 struct bmc_device {
308 	struct platform_device pdev;
309 	struct list_head       intfs; /* Interfaces on this BMC. */
310 	struct ipmi_device_id  id;
311 	struct ipmi_device_id  fetch_id;
312 	int                    dyn_id_set;
313 	unsigned long          dyn_id_expiry;
314 	struct mutex           dyn_mutex; /* Protects id, intfs, & dyn* */
315 	guid_t                 guid;
316 	guid_t                 fetch_guid;
317 	int                    dyn_guid_set;
318 	struct kref	       usecount;
319 	struct work_struct     remove_work;
320 };
321 #define to_bmc_device(x) container_of((x), struct bmc_device, pdev.dev)
322 
323 static int bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
324 			     struct ipmi_device_id *id,
325 			     bool *guid_set, guid_t *guid);
326 
327 /*
328  * Various statistics for IPMI, these index stats[] in the ipmi_smi
329  * structure.
330  */
331 enum ipmi_stat_indexes {
332 	/* Commands we got from the user that were invalid. */
333 	IPMI_STAT_sent_invalid_commands = 0,
334 
335 	/* Commands we sent to the MC. */
336 	IPMI_STAT_sent_local_commands,
337 
338 	/* Responses from the MC that were delivered to a user. */
339 	IPMI_STAT_handled_local_responses,
340 
341 	/* Responses from the MC that were not delivered to a user. */
342 	IPMI_STAT_unhandled_local_responses,
343 
344 	/* Commands we sent out to the IPMB bus. */
345 	IPMI_STAT_sent_ipmb_commands,
346 
347 	/* Commands sent on the IPMB that had errors on the SEND CMD */
348 	IPMI_STAT_sent_ipmb_command_errs,
349 
350 	/* Each retransmit increments this count. */
351 	IPMI_STAT_retransmitted_ipmb_commands,
352 
353 	/*
354 	 * When a message times out (runs out of retransmits) this is
355 	 * incremented.
356 	 */
357 	IPMI_STAT_timed_out_ipmb_commands,
358 
359 	/*
360 	 * This is like above, but for broadcasts.  Broadcasts are
361 	 * *not* included in the above count (they are expected to
362 	 * time out).
363 	 */
364 	IPMI_STAT_timed_out_ipmb_broadcasts,
365 
366 	/* Responses I have sent to the IPMB bus. */
367 	IPMI_STAT_sent_ipmb_responses,
368 
369 	/* The response was delivered to the user. */
370 	IPMI_STAT_handled_ipmb_responses,
371 
372 	/* The response had invalid data in it. */
373 	IPMI_STAT_invalid_ipmb_responses,
374 
375 	/* The response didn't have anyone waiting for it. */
376 	IPMI_STAT_unhandled_ipmb_responses,
377 
378 	/* Commands we sent out to the IPMB bus. */
379 	IPMI_STAT_sent_lan_commands,
380 
381 	/* Commands sent on the IPMB that had errors on the SEND CMD */
382 	IPMI_STAT_sent_lan_command_errs,
383 
384 	/* Each retransmit increments this count. */
385 	IPMI_STAT_retransmitted_lan_commands,
386 
387 	/*
388 	 * When a message times out (runs out of retransmits) this is
389 	 * incremented.
390 	 */
391 	IPMI_STAT_timed_out_lan_commands,
392 
393 	/* Responses I have sent to the IPMB bus. */
394 	IPMI_STAT_sent_lan_responses,
395 
396 	/* The response was delivered to the user. */
397 	IPMI_STAT_handled_lan_responses,
398 
399 	/* The response had invalid data in it. */
400 	IPMI_STAT_invalid_lan_responses,
401 
402 	/* The response didn't have anyone waiting for it. */
403 	IPMI_STAT_unhandled_lan_responses,
404 
405 	/* The command was delivered to the user. */
406 	IPMI_STAT_handled_commands,
407 
408 	/* The command had invalid data in it. */
409 	IPMI_STAT_invalid_commands,
410 
411 	/* The command didn't have anyone waiting for it. */
412 	IPMI_STAT_unhandled_commands,
413 
414 	/* Invalid data in an event. */
415 	IPMI_STAT_invalid_events,
416 
417 	/* Events that were received with the proper format. */
418 	IPMI_STAT_events,
419 
420 	/* Retransmissions on IPMB that failed. */
421 	IPMI_STAT_dropped_rexmit_ipmb_commands,
422 
423 	/* Retransmissions on LAN that failed. */
424 	IPMI_STAT_dropped_rexmit_lan_commands,
425 
426 	/* This *must* remain last, add new values above this. */
427 	IPMI_NUM_STATS
428 };
429 
430 
431 #define IPMI_IPMB_NUM_SEQ	64
432 struct ipmi_smi {
433 	struct module *owner;
434 
435 	/* What interface number are we? */
436 	int intf_num;
437 
438 	struct kref refcount;
439 
440 	/* Set when the interface is being unregistered. */
441 	bool in_shutdown;
442 
443 	/* Used for a list of interfaces. */
444 	struct list_head link;
445 
446 	/*
447 	 * The list of upper layers that are using me.  seq_lock write
448 	 * protects this.  Read protection is with srcu.
449 	 */
450 	struct list_head users;
451 	struct srcu_struct users_srcu;
452 
453 	/* Used for wake ups at startup. */
454 	wait_queue_head_t waitq;
455 
456 	/*
457 	 * Prevents the interface from being unregistered when the
458 	 * interface is used by being looked up through the BMC
459 	 * structure.
460 	 */
461 	struct mutex bmc_reg_mutex;
462 
463 	struct bmc_device tmp_bmc;
464 	struct bmc_device *bmc;
465 	bool bmc_registered;
466 	struct list_head bmc_link;
467 	char *my_dev_name;
468 	bool in_bmc_register;  /* Handle recursive situations.  Yuck. */
469 	struct work_struct bmc_reg_work;
470 
471 	const struct ipmi_smi_handlers *handlers;
472 	void                     *send_info;
473 
474 	/* Driver-model device for the system interface. */
475 	struct device          *si_dev;
476 
477 	/*
478 	 * A table of sequence numbers for this interface.  We use the
479 	 * sequence numbers for IPMB messages that go out of the
480 	 * interface to match them up with their responses.  A routine
481 	 * is called periodically to time the items in this list.
482 	 */
483 	spinlock_t       seq_lock;
484 	struct seq_table seq_table[IPMI_IPMB_NUM_SEQ];
485 	int curr_seq;
486 
487 	/*
488 	 * Messages queued for delivery.  If delivery fails (out of memory
489 	 * for instance), They will stay in here to be processed later in a
490 	 * periodic timer interrupt.  The tasklet is for handling received
491 	 * messages directly from the handler.
492 	 */
493 	spinlock_t       waiting_rcv_msgs_lock;
494 	struct list_head waiting_rcv_msgs;
495 	atomic_t	 watchdog_pretimeouts_to_deliver;
496 	struct tasklet_struct recv_tasklet;
497 
498 	spinlock_t             xmit_msgs_lock;
499 	struct list_head       xmit_msgs;
500 	struct ipmi_smi_msg    *curr_msg;
501 	struct list_head       hp_xmit_msgs;
502 
503 	/*
504 	 * The list of command receivers that are registered for commands
505 	 * on this interface.
506 	 */
507 	struct mutex     cmd_rcvrs_mutex;
508 	struct list_head cmd_rcvrs;
509 
510 	/*
511 	 * Events that were queues because no one was there to receive
512 	 * them.
513 	 */
514 	spinlock_t       events_lock; /* For dealing with event stuff. */
515 	struct list_head waiting_events;
516 	unsigned int     waiting_events_count; /* How many events in queue? */
517 	char             delivering_events;
518 	char             event_msg_printed;
519 
520 	/* How many users are waiting for events? */
521 	atomic_t         event_waiters;
522 	unsigned int     ticks_to_req_ev;
523 
524 	spinlock_t       watch_lock; /* For dealing with watch stuff below. */
525 
526 	/* How many users are waiting for commands? */
527 	unsigned int     command_waiters;
528 
529 	/* How many users are waiting for watchdogs? */
530 	unsigned int     watchdog_waiters;
531 
532 	/* How many users are waiting for message responses? */
533 	unsigned int     response_waiters;
534 
535 	/*
536 	 * Tells what the lower layer has last been asked to watch for,
537 	 * messages and/or watchdogs.  Protected by watch_lock.
538 	 */
539 	unsigned int     last_watch_mask;
540 
541 	/*
542 	 * The event receiver for my BMC, only really used at panic
543 	 * shutdown as a place to store this.
544 	 */
545 	unsigned char event_receiver;
546 	unsigned char event_receiver_lun;
547 	unsigned char local_sel_device;
548 	unsigned char local_event_generator;
549 
550 	/* For handling of maintenance mode. */
551 	int maintenance_mode;
552 	bool maintenance_mode_enable;
553 	int auto_maintenance_timeout;
554 	spinlock_t maintenance_mode_lock; /* Used in a timer... */
555 
556 	/*
557 	 * If we are doing maintenance on something on IPMB, extend
558 	 * the timeout time to avoid timeouts writing firmware and
559 	 * such.
560 	 */
561 	int ipmb_maintenance_mode_timeout;
562 
563 	/*
564 	 * A cheap hack, if this is non-null and a message to an
565 	 * interface comes in with a NULL user, call this routine with
566 	 * it.  Note that the message will still be freed by the
567 	 * caller.  This only works on the system interface.
568 	 *
569 	 * Protected by bmc_reg_mutex.
570 	 */
571 	void (*null_user_handler)(struct ipmi_smi *intf,
572 				  struct ipmi_recv_msg *msg);
573 
574 	/*
575 	 * When we are scanning the channels for an SMI, this will
576 	 * tell which channel we are scanning.
577 	 */
578 	int curr_channel;
579 
580 	/* Channel information */
581 	struct ipmi_channel_set *channel_list;
582 	unsigned int curr_working_cset; /* First index into the following. */
583 	struct ipmi_channel_set wchannels[2];
584 	struct ipmi_my_addrinfo addrinfo[IPMI_MAX_CHANNELS];
585 	bool channels_ready;
586 
587 	atomic_t stats[IPMI_NUM_STATS];
588 
589 	/*
590 	 * run_to_completion duplicate of smb_info, smi_info
591 	 * and ipmi_serial_info structures. Used to decrease numbers of
592 	 * parameters passed by "low" level IPMI code.
593 	 */
594 	int run_to_completion;
595 };
596 #define to_si_intf_from_dev(device) container_of(device, struct ipmi_smi, dev)
597 
598 static void __get_guid(struct ipmi_smi *intf);
599 static void __ipmi_bmc_unregister(struct ipmi_smi *intf);
600 static int __ipmi_bmc_register(struct ipmi_smi *intf,
601 			       struct ipmi_device_id *id,
602 			       bool guid_set, guid_t *guid, int intf_num);
603 static int __scan_channels(struct ipmi_smi *intf, struct ipmi_device_id *id);
604 
605 
606 /**
607  * The driver model view of the IPMI messaging driver.
608  */
609 static struct platform_driver ipmidriver = {
610 	.driver = {
611 		.name = "ipmi",
612 		.bus = &platform_bus_type
613 	}
614 };
615 /*
616  * This mutex keeps us from adding the same BMC twice.
617  */
618 static DEFINE_MUTEX(ipmidriver_mutex);
619 
620 static LIST_HEAD(ipmi_interfaces);
621 static DEFINE_MUTEX(ipmi_interfaces_mutex);
622 #define ipmi_interfaces_mutex_held() \
623 	lockdep_is_held(&ipmi_interfaces_mutex)
624 static struct srcu_struct ipmi_interfaces_srcu;
625 
626 /*
627  * List of watchers that want to know when smi's are added and deleted.
628  */
629 static LIST_HEAD(smi_watchers);
630 static DEFINE_MUTEX(smi_watchers_mutex);
631 
632 #define ipmi_inc_stat(intf, stat) \
633 	atomic_inc(&(intf)->stats[IPMI_STAT_ ## stat])
634 #define ipmi_get_stat(intf, stat) \
635 	((unsigned int) atomic_read(&(intf)->stats[IPMI_STAT_ ## stat]))
636 
637 static const char * const addr_src_to_str[] = {
638 	"invalid", "hotmod", "hardcoded", "SPMI", "ACPI", "SMBIOS", "PCI",
639 	"device-tree", "platform"
640 };
641 
642 const char *ipmi_addr_src_to_str(enum ipmi_addr_src src)
643 {
644 	if (src >= SI_LAST)
645 		src = 0; /* Invalid */
646 	return addr_src_to_str[src];
647 }
648 EXPORT_SYMBOL(ipmi_addr_src_to_str);
649 
650 static int is_lan_addr(struct ipmi_addr *addr)
651 {
652 	return addr->addr_type == IPMI_LAN_ADDR_TYPE;
653 }
654 
655 static int is_ipmb_addr(struct ipmi_addr *addr)
656 {
657 	return addr->addr_type == IPMI_IPMB_ADDR_TYPE;
658 }
659 
660 static int is_ipmb_bcast_addr(struct ipmi_addr *addr)
661 {
662 	return addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE;
663 }
664 
665 static void free_recv_msg_list(struct list_head *q)
666 {
667 	struct ipmi_recv_msg *msg, *msg2;
668 
669 	list_for_each_entry_safe(msg, msg2, q, link) {
670 		list_del(&msg->link);
671 		ipmi_free_recv_msg(msg);
672 	}
673 }
674 
675 static void free_smi_msg_list(struct list_head *q)
676 {
677 	struct ipmi_smi_msg *msg, *msg2;
678 
679 	list_for_each_entry_safe(msg, msg2, q, link) {
680 		list_del(&msg->link);
681 		ipmi_free_smi_msg(msg);
682 	}
683 }
684 
685 static void clean_up_interface_data(struct ipmi_smi *intf)
686 {
687 	int              i;
688 	struct cmd_rcvr  *rcvr, *rcvr2;
689 	struct list_head list;
690 
691 	tasklet_kill(&intf->recv_tasklet);
692 
693 	free_smi_msg_list(&intf->waiting_rcv_msgs);
694 	free_recv_msg_list(&intf->waiting_events);
695 
696 	/*
697 	 * Wholesale remove all the entries from the list in the
698 	 * interface and wait for RCU to know that none are in use.
699 	 */
700 	mutex_lock(&intf->cmd_rcvrs_mutex);
701 	INIT_LIST_HEAD(&list);
702 	list_splice_init_rcu(&intf->cmd_rcvrs, &list, synchronize_rcu);
703 	mutex_unlock(&intf->cmd_rcvrs_mutex);
704 
705 	list_for_each_entry_safe(rcvr, rcvr2, &list, link)
706 		kfree(rcvr);
707 
708 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
709 		if ((intf->seq_table[i].inuse)
710 					&& (intf->seq_table[i].recv_msg))
711 			ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
712 	}
713 }
714 
715 static void intf_free(struct kref *ref)
716 {
717 	struct ipmi_smi *intf = container_of(ref, struct ipmi_smi, refcount);
718 
719 	clean_up_interface_data(intf);
720 	kfree(intf);
721 }
722 
723 struct watcher_entry {
724 	int              intf_num;
725 	struct ipmi_smi  *intf;
726 	struct list_head link;
727 };
728 
729 int ipmi_smi_watcher_register(struct ipmi_smi_watcher *watcher)
730 {
731 	struct ipmi_smi *intf;
732 	int index, rv;
733 
734 	/*
735 	 * Make sure the driver is actually initialized, this handles
736 	 * problems with initialization order.
737 	 */
738 	rv = ipmi_init_msghandler();
739 	if (rv)
740 		return rv;
741 
742 	mutex_lock(&smi_watchers_mutex);
743 
744 	list_add(&watcher->link, &smi_watchers);
745 
746 	index = srcu_read_lock(&ipmi_interfaces_srcu);
747 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
748 		int intf_num = READ_ONCE(intf->intf_num);
749 
750 		if (intf_num == -1)
751 			continue;
752 		watcher->new_smi(intf_num, intf->si_dev);
753 	}
754 	srcu_read_unlock(&ipmi_interfaces_srcu, index);
755 
756 	mutex_unlock(&smi_watchers_mutex);
757 
758 	return 0;
759 }
760 EXPORT_SYMBOL(ipmi_smi_watcher_register);
761 
762 int ipmi_smi_watcher_unregister(struct ipmi_smi_watcher *watcher)
763 {
764 	mutex_lock(&smi_watchers_mutex);
765 	list_del(&watcher->link);
766 	mutex_unlock(&smi_watchers_mutex);
767 	return 0;
768 }
769 EXPORT_SYMBOL(ipmi_smi_watcher_unregister);
770 
771 /*
772  * Must be called with smi_watchers_mutex held.
773  */
774 static void
775 call_smi_watchers(int i, struct device *dev)
776 {
777 	struct ipmi_smi_watcher *w;
778 
779 	mutex_lock(&smi_watchers_mutex);
780 	list_for_each_entry(w, &smi_watchers, link) {
781 		if (try_module_get(w->owner)) {
782 			w->new_smi(i, dev);
783 			module_put(w->owner);
784 		}
785 	}
786 	mutex_unlock(&smi_watchers_mutex);
787 }
788 
789 static int
790 ipmi_addr_equal(struct ipmi_addr *addr1, struct ipmi_addr *addr2)
791 {
792 	if (addr1->addr_type != addr2->addr_type)
793 		return 0;
794 
795 	if (addr1->channel != addr2->channel)
796 		return 0;
797 
798 	if (addr1->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
799 		struct ipmi_system_interface_addr *smi_addr1
800 		    = (struct ipmi_system_interface_addr *) addr1;
801 		struct ipmi_system_interface_addr *smi_addr2
802 		    = (struct ipmi_system_interface_addr *) addr2;
803 		return (smi_addr1->lun == smi_addr2->lun);
804 	}
805 
806 	if (is_ipmb_addr(addr1) || is_ipmb_bcast_addr(addr1)) {
807 		struct ipmi_ipmb_addr *ipmb_addr1
808 		    = (struct ipmi_ipmb_addr *) addr1;
809 		struct ipmi_ipmb_addr *ipmb_addr2
810 		    = (struct ipmi_ipmb_addr *) addr2;
811 
812 		return ((ipmb_addr1->slave_addr == ipmb_addr2->slave_addr)
813 			&& (ipmb_addr1->lun == ipmb_addr2->lun));
814 	}
815 
816 	if (is_lan_addr(addr1)) {
817 		struct ipmi_lan_addr *lan_addr1
818 			= (struct ipmi_lan_addr *) addr1;
819 		struct ipmi_lan_addr *lan_addr2
820 		    = (struct ipmi_lan_addr *) addr2;
821 
822 		return ((lan_addr1->remote_SWID == lan_addr2->remote_SWID)
823 			&& (lan_addr1->local_SWID == lan_addr2->local_SWID)
824 			&& (lan_addr1->session_handle
825 			    == lan_addr2->session_handle)
826 			&& (lan_addr1->lun == lan_addr2->lun));
827 	}
828 
829 	return 1;
830 }
831 
832 int ipmi_validate_addr(struct ipmi_addr *addr, int len)
833 {
834 	if (len < sizeof(struct ipmi_system_interface_addr))
835 		return -EINVAL;
836 
837 	if (addr->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
838 		if (addr->channel != IPMI_BMC_CHANNEL)
839 			return -EINVAL;
840 		return 0;
841 	}
842 
843 	if ((addr->channel == IPMI_BMC_CHANNEL)
844 	    || (addr->channel >= IPMI_MAX_CHANNELS)
845 	    || (addr->channel < 0))
846 		return -EINVAL;
847 
848 	if (is_ipmb_addr(addr) || is_ipmb_bcast_addr(addr)) {
849 		if (len < sizeof(struct ipmi_ipmb_addr))
850 			return -EINVAL;
851 		return 0;
852 	}
853 
854 	if (is_lan_addr(addr)) {
855 		if (len < sizeof(struct ipmi_lan_addr))
856 			return -EINVAL;
857 		return 0;
858 	}
859 
860 	return -EINVAL;
861 }
862 EXPORT_SYMBOL(ipmi_validate_addr);
863 
864 unsigned int ipmi_addr_length(int addr_type)
865 {
866 	if (addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
867 		return sizeof(struct ipmi_system_interface_addr);
868 
869 	if ((addr_type == IPMI_IPMB_ADDR_TYPE)
870 			|| (addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE))
871 		return sizeof(struct ipmi_ipmb_addr);
872 
873 	if (addr_type == IPMI_LAN_ADDR_TYPE)
874 		return sizeof(struct ipmi_lan_addr);
875 
876 	return 0;
877 }
878 EXPORT_SYMBOL(ipmi_addr_length);
879 
880 static int deliver_response(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
881 {
882 	int rv = 0;
883 
884 	if (!msg->user) {
885 		/* Special handling for NULL users. */
886 		if (intf->null_user_handler) {
887 			intf->null_user_handler(intf, msg);
888 		} else {
889 			/* No handler, so give up. */
890 			rv = -EINVAL;
891 		}
892 		ipmi_free_recv_msg(msg);
893 	} else if (oops_in_progress) {
894 		/*
895 		 * If we are running in the panic context, calling the
896 		 * receive handler doesn't much meaning and has a deadlock
897 		 * risk.  At this moment, simply skip it in that case.
898 		 */
899 		ipmi_free_recv_msg(msg);
900 	} else {
901 		int index;
902 		struct ipmi_user *user = acquire_ipmi_user(msg->user, &index);
903 
904 		if (user) {
905 			user->handler->ipmi_recv_hndl(msg, user->handler_data);
906 			release_ipmi_user(user, index);
907 		} else {
908 			/* User went away, give up. */
909 			ipmi_free_recv_msg(msg);
910 			rv = -EINVAL;
911 		}
912 	}
913 
914 	return rv;
915 }
916 
917 static void deliver_local_response(struct ipmi_smi *intf,
918 				   struct ipmi_recv_msg *msg)
919 {
920 	if (deliver_response(intf, msg))
921 		ipmi_inc_stat(intf, unhandled_local_responses);
922 	else
923 		ipmi_inc_stat(intf, handled_local_responses);
924 }
925 
926 static void deliver_err_response(struct ipmi_smi *intf,
927 				 struct ipmi_recv_msg *msg, int err)
928 {
929 	msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
930 	msg->msg_data[0] = err;
931 	msg->msg.netfn |= 1; /* Convert to a response. */
932 	msg->msg.data_len = 1;
933 	msg->msg.data = msg->msg_data;
934 	deliver_local_response(intf, msg);
935 }
936 
937 static void smi_add_watch(struct ipmi_smi *intf, unsigned int flags)
938 {
939 	unsigned long iflags;
940 
941 	if (!intf->handlers->set_need_watch)
942 		return;
943 
944 	spin_lock_irqsave(&intf->watch_lock, iflags);
945 	if (flags & IPMI_WATCH_MASK_CHECK_MESSAGES)
946 		intf->response_waiters++;
947 
948 	if (flags & IPMI_WATCH_MASK_CHECK_WATCHDOG)
949 		intf->watchdog_waiters++;
950 
951 	if (flags & IPMI_WATCH_MASK_CHECK_COMMANDS)
952 		intf->command_waiters++;
953 
954 	if ((intf->last_watch_mask & flags) != flags) {
955 		intf->last_watch_mask |= flags;
956 		intf->handlers->set_need_watch(intf->send_info,
957 					       intf->last_watch_mask);
958 	}
959 	spin_unlock_irqrestore(&intf->watch_lock, iflags);
960 }
961 
962 static void smi_remove_watch(struct ipmi_smi *intf, unsigned int flags)
963 {
964 	unsigned long iflags;
965 
966 	if (!intf->handlers->set_need_watch)
967 		return;
968 
969 	spin_lock_irqsave(&intf->watch_lock, iflags);
970 	if (flags & IPMI_WATCH_MASK_CHECK_MESSAGES)
971 		intf->response_waiters--;
972 
973 	if (flags & IPMI_WATCH_MASK_CHECK_WATCHDOG)
974 		intf->watchdog_waiters--;
975 
976 	if (flags & IPMI_WATCH_MASK_CHECK_COMMANDS)
977 		intf->command_waiters--;
978 
979 	flags = 0;
980 	if (intf->response_waiters)
981 		flags |= IPMI_WATCH_MASK_CHECK_MESSAGES;
982 	if (intf->watchdog_waiters)
983 		flags |= IPMI_WATCH_MASK_CHECK_WATCHDOG;
984 	if (intf->command_waiters)
985 		flags |= IPMI_WATCH_MASK_CHECK_COMMANDS;
986 
987 	if (intf->last_watch_mask != flags) {
988 		intf->last_watch_mask = flags;
989 		intf->handlers->set_need_watch(intf->send_info,
990 					       intf->last_watch_mask);
991 	}
992 	spin_unlock_irqrestore(&intf->watch_lock, iflags);
993 }
994 
995 /*
996  * Find the next sequence number not being used and add the given
997  * message with the given timeout to the sequence table.  This must be
998  * called with the interface's seq_lock held.
999  */
1000 static int intf_next_seq(struct ipmi_smi      *intf,
1001 			 struct ipmi_recv_msg *recv_msg,
1002 			 unsigned long        timeout,
1003 			 int                  retries,
1004 			 int                  broadcast,
1005 			 unsigned char        *seq,
1006 			 long                 *seqid)
1007 {
1008 	int          rv = 0;
1009 	unsigned int i;
1010 
1011 	if (timeout == 0)
1012 		timeout = default_retry_ms;
1013 	if (retries < 0)
1014 		retries = default_max_retries;
1015 
1016 	for (i = intf->curr_seq; (i+1)%IPMI_IPMB_NUM_SEQ != intf->curr_seq;
1017 					i = (i+1)%IPMI_IPMB_NUM_SEQ) {
1018 		if (!intf->seq_table[i].inuse)
1019 			break;
1020 	}
1021 
1022 	if (!intf->seq_table[i].inuse) {
1023 		intf->seq_table[i].recv_msg = recv_msg;
1024 
1025 		/*
1026 		 * Start with the maximum timeout, when the send response
1027 		 * comes in we will start the real timer.
1028 		 */
1029 		intf->seq_table[i].timeout = MAX_MSG_TIMEOUT;
1030 		intf->seq_table[i].orig_timeout = timeout;
1031 		intf->seq_table[i].retries_left = retries;
1032 		intf->seq_table[i].broadcast = broadcast;
1033 		intf->seq_table[i].inuse = 1;
1034 		intf->seq_table[i].seqid = NEXT_SEQID(intf->seq_table[i].seqid);
1035 		*seq = i;
1036 		*seqid = intf->seq_table[i].seqid;
1037 		intf->curr_seq = (i+1)%IPMI_IPMB_NUM_SEQ;
1038 		smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1039 		need_waiter(intf);
1040 	} else {
1041 		rv = -EAGAIN;
1042 	}
1043 
1044 	return rv;
1045 }
1046 
1047 /*
1048  * Return the receive message for the given sequence number and
1049  * release the sequence number so it can be reused.  Some other data
1050  * is passed in to be sure the message matches up correctly (to help
1051  * guard against message coming in after their timeout and the
1052  * sequence number being reused).
1053  */
1054 static int intf_find_seq(struct ipmi_smi      *intf,
1055 			 unsigned char        seq,
1056 			 short                channel,
1057 			 unsigned char        cmd,
1058 			 unsigned char        netfn,
1059 			 struct ipmi_addr     *addr,
1060 			 struct ipmi_recv_msg **recv_msg)
1061 {
1062 	int           rv = -ENODEV;
1063 	unsigned long flags;
1064 
1065 	if (seq >= IPMI_IPMB_NUM_SEQ)
1066 		return -EINVAL;
1067 
1068 	spin_lock_irqsave(&intf->seq_lock, flags);
1069 	if (intf->seq_table[seq].inuse) {
1070 		struct ipmi_recv_msg *msg = intf->seq_table[seq].recv_msg;
1071 
1072 		if ((msg->addr.channel == channel) && (msg->msg.cmd == cmd)
1073 				&& (msg->msg.netfn == netfn)
1074 				&& (ipmi_addr_equal(addr, &msg->addr))) {
1075 			*recv_msg = msg;
1076 			intf->seq_table[seq].inuse = 0;
1077 			smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1078 			rv = 0;
1079 		}
1080 	}
1081 	spin_unlock_irqrestore(&intf->seq_lock, flags);
1082 
1083 	return rv;
1084 }
1085 
1086 
1087 /* Start the timer for a specific sequence table entry. */
1088 static int intf_start_seq_timer(struct ipmi_smi *intf,
1089 				long       msgid)
1090 {
1091 	int           rv = -ENODEV;
1092 	unsigned long flags;
1093 	unsigned char seq;
1094 	unsigned long seqid;
1095 
1096 
1097 	GET_SEQ_FROM_MSGID(msgid, seq, seqid);
1098 
1099 	spin_lock_irqsave(&intf->seq_lock, flags);
1100 	/*
1101 	 * We do this verification because the user can be deleted
1102 	 * while a message is outstanding.
1103 	 */
1104 	if ((intf->seq_table[seq].inuse)
1105 				&& (intf->seq_table[seq].seqid == seqid)) {
1106 		struct seq_table *ent = &intf->seq_table[seq];
1107 		ent->timeout = ent->orig_timeout;
1108 		rv = 0;
1109 	}
1110 	spin_unlock_irqrestore(&intf->seq_lock, flags);
1111 
1112 	return rv;
1113 }
1114 
1115 /* Got an error for the send message for a specific sequence number. */
1116 static int intf_err_seq(struct ipmi_smi *intf,
1117 			long         msgid,
1118 			unsigned int err)
1119 {
1120 	int                  rv = -ENODEV;
1121 	unsigned long        flags;
1122 	unsigned char        seq;
1123 	unsigned long        seqid;
1124 	struct ipmi_recv_msg *msg = NULL;
1125 
1126 
1127 	GET_SEQ_FROM_MSGID(msgid, seq, seqid);
1128 
1129 	spin_lock_irqsave(&intf->seq_lock, flags);
1130 	/*
1131 	 * We do this verification because the user can be deleted
1132 	 * while a message is outstanding.
1133 	 */
1134 	if ((intf->seq_table[seq].inuse)
1135 				&& (intf->seq_table[seq].seqid == seqid)) {
1136 		struct seq_table *ent = &intf->seq_table[seq];
1137 
1138 		ent->inuse = 0;
1139 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1140 		msg = ent->recv_msg;
1141 		rv = 0;
1142 	}
1143 	spin_unlock_irqrestore(&intf->seq_lock, flags);
1144 
1145 	if (msg)
1146 		deliver_err_response(intf, msg, err);
1147 
1148 	return rv;
1149 }
1150 
1151 static void free_user_work(struct work_struct *work)
1152 {
1153 	struct ipmi_user *user = container_of(work, struct ipmi_user,
1154 					      remove_work);
1155 
1156 	cleanup_srcu_struct(&user->release_barrier);
1157 	vfree(user);
1158 }
1159 
1160 int ipmi_create_user(unsigned int          if_num,
1161 		     const struct ipmi_user_hndl *handler,
1162 		     void                  *handler_data,
1163 		     struct ipmi_user      **user)
1164 {
1165 	unsigned long flags;
1166 	struct ipmi_user *new_user;
1167 	int           rv, index;
1168 	struct ipmi_smi *intf;
1169 
1170 	/*
1171 	 * There is no module usecount here, because it's not
1172 	 * required.  Since this can only be used by and called from
1173 	 * other modules, they will implicitly use this module, and
1174 	 * thus this can't be removed unless the other modules are
1175 	 * removed.
1176 	 */
1177 
1178 	if (handler == NULL)
1179 		return -EINVAL;
1180 
1181 	/*
1182 	 * Make sure the driver is actually initialized, this handles
1183 	 * problems with initialization order.
1184 	 */
1185 	rv = ipmi_init_msghandler();
1186 	if (rv)
1187 		return rv;
1188 
1189 	new_user = vzalloc(sizeof(*new_user));
1190 	if (!new_user)
1191 		return -ENOMEM;
1192 
1193 	index = srcu_read_lock(&ipmi_interfaces_srcu);
1194 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
1195 		if (intf->intf_num == if_num)
1196 			goto found;
1197 	}
1198 	/* Not found, return an error */
1199 	rv = -EINVAL;
1200 	goto out_kfree;
1201 
1202  found:
1203 	INIT_WORK(&new_user->remove_work, free_user_work);
1204 
1205 	rv = init_srcu_struct(&new_user->release_barrier);
1206 	if (rv)
1207 		goto out_kfree;
1208 
1209 	if (!try_module_get(intf->owner)) {
1210 		rv = -ENODEV;
1211 		goto out_kfree;
1212 	}
1213 
1214 	/* Note that each existing user holds a refcount to the interface. */
1215 	kref_get(&intf->refcount);
1216 
1217 	kref_init(&new_user->refcount);
1218 	new_user->handler = handler;
1219 	new_user->handler_data = handler_data;
1220 	new_user->intf = intf;
1221 	new_user->gets_events = false;
1222 
1223 	rcu_assign_pointer(new_user->self, new_user);
1224 	spin_lock_irqsave(&intf->seq_lock, flags);
1225 	list_add_rcu(&new_user->link, &intf->users);
1226 	spin_unlock_irqrestore(&intf->seq_lock, flags);
1227 	if (handler->ipmi_watchdog_pretimeout)
1228 		/* User wants pretimeouts, so make sure to watch for them. */
1229 		smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_WATCHDOG);
1230 	srcu_read_unlock(&ipmi_interfaces_srcu, index);
1231 	*user = new_user;
1232 	return 0;
1233 
1234 out_kfree:
1235 	srcu_read_unlock(&ipmi_interfaces_srcu, index);
1236 	vfree(new_user);
1237 	return rv;
1238 }
1239 EXPORT_SYMBOL(ipmi_create_user);
1240 
1241 int ipmi_get_smi_info(int if_num, struct ipmi_smi_info *data)
1242 {
1243 	int rv, index;
1244 	struct ipmi_smi *intf;
1245 
1246 	index = srcu_read_lock(&ipmi_interfaces_srcu);
1247 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
1248 		if (intf->intf_num == if_num)
1249 			goto found;
1250 	}
1251 	srcu_read_unlock(&ipmi_interfaces_srcu, index);
1252 
1253 	/* Not found, return an error */
1254 	return -EINVAL;
1255 
1256 found:
1257 	if (!intf->handlers->get_smi_info)
1258 		rv = -ENOTTY;
1259 	else
1260 		rv = intf->handlers->get_smi_info(intf->send_info, data);
1261 	srcu_read_unlock(&ipmi_interfaces_srcu, index);
1262 
1263 	return rv;
1264 }
1265 EXPORT_SYMBOL(ipmi_get_smi_info);
1266 
1267 static void free_user(struct kref *ref)
1268 {
1269 	struct ipmi_user *user = container_of(ref, struct ipmi_user, refcount);
1270 
1271 	/* SRCU cleanup must happen in task context. */
1272 	schedule_work(&user->remove_work);
1273 }
1274 
1275 static void _ipmi_destroy_user(struct ipmi_user *user)
1276 {
1277 	struct ipmi_smi  *intf = user->intf;
1278 	int              i;
1279 	unsigned long    flags;
1280 	struct cmd_rcvr  *rcvr;
1281 	struct cmd_rcvr  *rcvrs = NULL;
1282 
1283 	if (!acquire_ipmi_user(user, &i)) {
1284 		/*
1285 		 * The user has already been cleaned up, just make sure
1286 		 * nothing is using it and return.
1287 		 */
1288 		synchronize_srcu(&user->release_barrier);
1289 		return;
1290 	}
1291 
1292 	rcu_assign_pointer(user->self, NULL);
1293 	release_ipmi_user(user, i);
1294 
1295 	synchronize_srcu(&user->release_barrier);
1296 
1297 	if (user->handler->shutdown)
1298 		user->handler->shutdown(user->handler_data);
1299 
1300 	if (user->handler->ipmi_watchdog_pretimeout)
1301 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_WATCHDOG);
1302 
1303 	if (user->gets_events)
1304 		atomic_dec(&intf->event_waiters);
1305 
1306 	/* Remove the user from the interface's sequence table. */
1307 	spin_lock_irqsave(&intf->seq_lock, flags);
1308 	list_del_rcu(&user->link);
1309 
1310 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
1311 		if (intf->seq_table[i].inuse
1312 		    && (intf->seq_table[i].recv_msg->user == user)) {
1313 			intf->seq_table[i].inuse = 0;
1314 			smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1315 			ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
1316 		}
1317 	}
1318 	spin_unlock_irqrestore(&intf->seq_lock, flags);
1319 
1320 	/*
1321 	 * Remove the user from the command receiver's table.  First
1322 	 * we build a list of everything (not using the standard link,
1323 	 * since other things may be using it till we do
1324 	 * synchronize_srcu()) then free everything in that list.
1325 	 */
1326 	mutex_lock(&intf->cmd_rcvrs_mutex);
1327 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1328 				lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1329 		if (rcvr->user == user) {
1330 			list_del_rcu(&rcvr->link);
1331 			rcvr->next = rcvrs;
1332 			rcvrs = rcvr;
1333 		}
1334 	}
1335 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1336 	synchronize_rcu();
1337 	while (rcvrs) {
1338 		rcvr = rcvrs;
1339 		rcvrs = rcvr->next;
1340 		kfree(rcvr);
1341 	}
1342 
1343 	kref_put(&intf->refcount, intf_free);
1344 	module_put(intf->owner);
1345 }
1346 
1347 int ipmi_destroy_user(struct ipmi_user *user)
1348 {
1349 	_ipmi_destroy_user(user);
1350 
1351 	kref_put(&user->refcount, free_user);
1352 
1353 	return 0;
1354 }
1355 EXPORT_SYMBOL(ipmi_destroy_user);
1356 
1357 int ipmi_get_version(struct ipmi_user *user,
1358 		     unsigned char *major,
1359 		     unsigned char *minor)
1360 {
1361 	struct ipmi_device_id id;
1362 	int rv, index;
1363 
1364 	user = acquire_ipmi_user(user, &index);
1365 	if (!user)
1366 		return -ENODEV;
1367 
1368 	rv = bmc_get_device_id(user->intf, NULL, &id, NULL, NULL);
1369 	if (!rv) {
1370 		*major = ipmi_version_major(&id);
1371 		*minor = ipmi_version_minor(&id);
1372 	}
1373 	release_ipmi_user(user, index);
1374 
1375 	return rv;
1376 }
1377 EXPORT_SYMBOL(ipmi_get_version);
1378 
1379 int ipmi_set_my_address(struct ipmi_user *user,
1380 			unsigned int  channel,
1381 			unsigned char address)
1382 {
1383 	int index, rv = 0;
1384 
1385 	user = acquire_ipmi_user(user, &index);
1386 	if (!user)
1387 		return -ENODEV;
1388 
1389 	if (channel >= IPMI_MAX_CHANNELS) {
1390 		rv = -EINVAL;
1391 	} else {
1392 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1393 		user->intf->addrinfo[channel].address = address;
1394 	}
1395 	release_ipmi_user(user, index);
1396 
1397 	return rv;
1398 }
1399 EXPORT_SYMBOL(ipmi_set_my_address);
1400 
1401 int ipmi_get_my_address(struct ipmi_user *user,
1402 			unsigned int  channel,
1403 			unsigned char *address)
1404 {
1405 	int index, rv = 0;
1406 
1407 	user = acquire_ipmi_user(user, &index);
1408 	if (!user)
1409 		return -ENODEV;
1410 
1411 	if (channel >= IPMI_MAX_CHANNELS) {
1412 		rv = -EINVAL;
1413 	} else {
1414 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1415 		*address = user->intf->addrinfo[channel].address;
1416 	}
1417 	release_ipmi_user(user, index);
1418 
1419 	return rv;
1420 }
1421 EXPORT_SYMBOL(ipmi_get_my_address);
1422 
1423 int ipmi_set_my_LUN(struct ipmi_user *user,
1424 		    unsigned int  channel,
1425 		    unsigned char LUN)
1426 {
1427 	int index, rv = 0;
1428 
1429 	user = acquire_ipmi_user(user, &index);
1430 	if (!user)
1431 		return -ENODEV;
1432 
1433 	if (channel >= IPMI_MAX_CHANNELS) {
1434 		rv = -EINVAL;
1435 	} else {
1436 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1437 		user->intf->addrinfo[channel].lun = LUN & 0x3;
1438 	}
1439 	release_ipmi_user(user, index);
1440 
1441 	return rv;
1442 }
1443 EXPORT_SYMBOL(ipmi_set_my_LUN);
1444 
1445 int ipmi_get_my_LUN(struct ipmi_user *user,
1446 		    unsigned int  channel,
1447 		    unsigned char *address)
1448 {
1449 	int index, rv = 0;
1450 
1451 	user = acquire_ipmi_user(user, &index);
1452 	if (!user)
1453 		return -ENODEV;
1454 
1455 	if (channel >= IPMI_MAX_CHANNELS) {
1456 		rv = -EINVAL;
1457 	} else {
1458 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1459 		*address = user->intf->addrinfo[channel].lun;
1460 	}
1461 	release_ipmi_user(user, index);
1462 
1463 	return rv;
1464 }
1465 EXPORT_SYMBOL(ipmi_get_my_LUN);
1466 
1467 int ipmi_get_maintenance_mode(struct ipmi_user *user)
1468 {
1469 	int mode, index;
1470 	unsigned long flags;
1471 
1472 	user = acquire_ipmi_user(user, &index);
1473 	if (!user)
1474 		return -ENODEV;
1475 
1476 	spin_lock_irqsave(&user->intf->maintenance_mode_lock, flags);
1477 	mode = user->intf->maintenance_mode;
1478 	spin_unlock_irqrestore(&user->intf->maintenance_mode_lock, flags);
1479 	release_ipmi_user(user, index);
1480 
1481 	return mode;
1482 }
1483 EXPORT_SYMBOL(ipmi_get_maintenance_mode);
1484 
1485 static void maintenance_mode_update(struct ipmi_smi *intf)
1486 {
1487 	if (intf->handlers->set_maintenance_mode)
1488 		intf->handlers->set_maintenance_mode(
1489 			intf->send_info, intf->maintenance_mode_enable);
1490 }
1491 
1492 int ipmi_set_maintenance_mode(struct ipmi_user *user, int mode)
1493 {
1494 	int rv = 0, index;
1495 	unsigned long flags;
1496 	struct ipmi_smi *intf = user->intf;
1497 
1498 	user = acquire_ipmi_user(user, &index);
1499 	if (!user)
1500 		return -ENODEV;
1501 
1502 	spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
1503 	if (intf->maintenance_mode != mode) {
1504 		switch (mode) {
1505 		case IPMI_MAINTENANCE_MODE_AUTO:
1506 			intf->maintenance_mode_enable
1507 				= (intf->auto_maintenance_timeout > 0);
1508 			break;
1509 
1510 		case IPMI_MAINTENANCE_MODE_OFF:
1511 			intf->maintenance_mode_enable = false;
1512 			break;
1513 
1514 		case IPMI_MAINTENANCE_MODE_ON:
1515 			intf->maintenance_mode_enable = true;
1516 			break;
1517 
1518 		default:
1519 			rv = -EINVAL;
1520 			goto out_unlock;
1521 		}
1522 		intf->maintenance_mode = mode;
1523 
1524 		maintenance_mode_update(intf);
1525 	}
1526  out_unlock:
1527 	spin_unlock_irqrestore(&intf->maintenance_mode_lock, flags);
1528 	release_ipmi_user(user, index);
1529 
1530 	return rv;
1531 }
1532 EXPORT_SYMBOL(ipmi_set_maintenance_mode);
1533 
1534 int ipmi_set_gets_events(struct ipmi_user *user, bool val)
1535 {
1536 	unsigned long        flags;
1537 	struct ipmi_smi      *intf = user->intf;
1538 	struct ipmi_recv_msg *msg, *msg2;
1539 	struct list_head     msgs;
1540 	int index;
1541 
1542 	user = acquire_ipmi_user(user, &index);
1543 	if (!user)
1544 		return -ENODEV;
1545 
1546 	INIT_LIST_HEAD(&msgs);
1547 
1548 	spin_lock_irqsave(&intf->events_lock, flags);
1549 	if (user->gets_events == val)
1550 		goto out;
1551 
1552 	user->gets_events = val;
1553 
1554 	if (val) {
1555 		if (atomic_inc_return(&intf->event_waiters) == 1)
1556 			need_waiter(intf);
1557 	} else {
1558 		atomic_dec(&intf->event_waiters);
1559 	}
1560 
1561 	if (intf->delivering_events)
1562 		/*
1563 		 * Another thread is delivering events for this, so
1564 		 * let it handle any new events.
1565 		 */
1566 		goto out;
1567 
1568 	/* Deliver any queued events. */
1569 	while (user->gets_events && !list_empty(&intf->waiting_events)) {
1570 		list_for_each_entry_safe(msg, msg2, &intf->waiting_events, link)
1571 			list_move_tail(&msg->link, &msgs);
1572 		intf->waiting_events_count = 0;
1573 		if (intf->event_msg_printed) {
1574 			dev_warn(intf->si_dev, "Event queue no longer full\n");
1575 			intf->event_msg_printed = 0;
1576 		}
1577 
1578 		intf->delivering_events = 1;
1579 		spin_unlock_irqrestore(&intf->events_lock, flags);
1580 
1581 		list_for_each_entry_safe(msg, msg2, &msgs, link) {
1582 			msg->user = user;
1583 			kref_get(&user->refcount);
1584 			deliver_local_response(intf, msg);
1585 		}
1586 
1587 		spin_lock_irqsave(&intf->events_lock, flags);
1588 		intf->delivering_events = 0;
1589 	}
1590 
1591  out:
1592 	spin_unlock_irqrestore(&intf->events_lock, flags);
1593 	release_ipmi_user(user, index);
1594 
1595 	return 0;
1596 }
1597 EXPORT_SYMBOL(ipmi_set_gets_events);
1598 
1599 static struct cmd_rcvr *find_cmd_rcvr(struct ipmi_smi *intf,
1600 				      unsigned char netfn,
1601 				      unsigned char cmd,
1602 				      unsigned char chan)
1603 {
1604 	struct cmd_rcvr *rcvr;
1605 
1606 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1607 				lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1608 		if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
1609 					&& (rcvr->chans & (1 << chan)))
1610 			return rcvr;
1611 	}
1612 	return NULL;
1613 }
1614 
1615 static int is_cmd_rcvr_exclusive(struct ipmi_smi *intf,
1616 				 unsigned char netfn,
1617 				 unsigned char cmd,
1618 				 unsigned int  chans)
1619 {
1620 	struct cmd_rcvr *rcvr;
1621 
1622 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1623 				lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1624 		if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
1625 					&& (rcvr->chans & chans))
1626 			return 0;
1627 	}
1628 	return 1;
1629 }
1630 
1631 int ipmi_register_for_cmd(struct ipmi_user *user,
1632 			  unsigned char netfn,
1633 			  unsigned char cmd,
1634 			  unsigned int  chans)
1635 {
1636 	struct ipmi_smi *intf = user->intf;
1637 	struct cmd_rcvr *rcvr;
1638 	int rv = 0, index;
1639 
1640 	user = acquire_ipmi_user(user, &index);
1641 	if (!user)
1642 		return -ENODEV;
1643 
1644 	rcvr = kmalloc(sizeof(*rcvr), GFP_KERNEL);
1645 	if (!rcvr) {
1646 		rv = -ENOMEM;
1647 		goto out_release;
1648 	}
1649 	rcvr->cmd = cmd;
1650 	rcvr->netfn = netfn;
1651 	rcvr->chans = chans;
1652 	rcvr->user = user;
1653 
1654 	mutex_lock(&intf->cmd_rcvrs_mutex);
1655 	/* Make sure the command/netfn is not already registered. */
1656 	if (!is_cmd_rcvr_exclusive(intf, netfn, cmd, chans)) {
1657 		rv = -EBUSY;
1658 		goto out_unlock;
1659 	}
1660 
1661 	smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS);
1662 
1663 	list_add_rcu(&rcvr->link, &intf->cmd_rcvrs);
1664 
1665 out_unlock:
1666 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1667 	if (rv)
1668 		kfree(rcvr);
1669 out_release:
1670 	release_ipmi_user(user, index);
1671 
1672 	return rv;
1673 }
1674 EXPORT_SYMBOL(ipmi_register_for_cmd);
1675 
1676 int ipmi_unregister_for_cmd(struct ipmi_user *user,
1677 			    unsigned char netfn,
1678 			    unsigned char cmd,
1679 			    unsigned int  chans)
1680 {
1681 	struct ipmi_smi *intf = user->intf;
1682 	struct cmd_rcvr *rcvr;
1683 	struct cmd_rcvr *rcvrs = NULL;
1684 	int i, rv = -ENOENT, index;
1685 
1686 	user = acquire_ipmi_user(user, &index);
1687 	if (!user)
1688 		return -ENODEV;
1689 
1690 	mutex_lock(&intf->cmd_rcvrs_mutex);
1691 	for (i = 0; i < IPMI_NUM_CHANNELS; i++) {
1692 		if (((1 << i) & chans) == 0)
1693 			continue;
1694 		rcvr = find_cmd_rcvr(intf, netfn, cmd, i);
1695 		if (rcvr == NULL)
1696 			continue;
1697 		if (rcvr->user == user) {
1698 			rv = 0;
1699 			rcvr->chans &= ~chans;
1700 			if (rcvr->chans == 0) {
1701 				list_del_rcu(&rcvr->link);
1702 				rcvr->next = rcvrs;
1703 				rcvrs = rcvr;
1704 			}
1705 		}
1706 	}
1707 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1708 	synchronize_rcu();
1709 	release_ipmi_user(user, index);
1710 	while (rcvrs) {
1711 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS);
1712 		rcvr = rcvrs;
1713 		rcvrs = rcvr->next;
1714 		kfree(rcvr);
1715 	}
1716 
1717 	return rv;
1718 }
1719 EXPORT_SYMBOL(ipmi_unregister_for_cmd);
1720 
1721 static unsigned char
1722 ipmb_checksum(unsigned char *data, int size)
1723 {
1724 	unsigned char csum = 0;
1725 
1726 	for (; size > 0; size--, data++)
1727 		csum += *data;
1728 
1729 	return -csum;
1730 }
1731 
1732 static inline void format_ipmb_msg(struct ipmi_smi_msg   *smi_msg,
1733 				   struct kernel_ipmi_msg *msg,
1734 				   struct ipmi_ipmb_addr *ipmb_addr,
1735 				   long                  msgid,
1736 				   unsigned char         ipmb_seq,
1737 				   int                   broadcast,
1738 				   unsigned char         source_address,
1739 				   unsigned char         source_lun)
1740 {
1741 	int i = broadcast;
1742 
1743 	/* Format the IPMB header data. */
1744 	smi_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
1745 	smi_msg->data[1] = IPMI_SEND_MSG_CMD;
1746 	smi_msg->data[2] = ipmb_addr->channel;
1747 	if (broadcast)
1748 		smi_msg->data[3] = 0;
1749 	smi_msg->data[i+3] = ipmb_addr->slave_addr;
1750 	smi_msg->data[i+4] = (msg->netfn << 2) | (ipmb_addr->lun & 0x3);
1751 	smi_msg->data[i+5] = ipmb_checksum(&smi_msg->data[i + 3], 2);
1752 	smi_msg->data[i+6] = source_address;
1753 	smi_msg->data[i+7] = (ipmb_seq << 2) | source_lun;
1754 	smi_msg->data[i+8] = msg->cmd;
1755 
1756 	/* Now tack on the data to the message. */
1757 	if (msg->data_len > 0)
1758 		memcpy(&smi_msg->data[i + 9], msg->data, msg->data_len);
1759 	smi_msg->data_size = msg->data_len + 9;
1760 
1761 	/* Now calculate the checksum and tack it on. */
1762 	smi_msg->data[i+smi_msg->data_size]
1763 		= ipmb_checksum(&smi_msg->data[i + 6], smi_msg->data_size - 6);
1764 
1765 	/*
1766 	 * Add on the checksum size and the offset from the
1767 	 * broadcast.
1768 	 */
1769 	smi_msg->data_size += 1 + i;
1770 
1771 	smi_msg->msgid = msgid;
1772 }
1773 
1774 static inline void format_lan_msg(struct ipmi_smi_msg   *smi_msg,
1775 				  struct kernel_ipmi_msg *msg,
1776 				  struct ipmi_lan_addr  *lan_addr,
1777 				  long                  msgid,
1778 				  unsigned char         ipmb_seq,
1779 				  unsigned char         source_lun)
1780 {
1781 	/* Format the IPMB header data. */
1782 	smi_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
1783 	smi_msg->data[1] = IPMI_SEND_MSG_CMD;
1784 	smi_msg->data[2] = lan_addr->channel;
1785 	smi_msg->data[3] = lan_addr->session_handle;
1786 	smi_msg->data[4] = lan_addr->remote_SWID;
1787 	smi_msg->data[5] = (msg->netfn << 2) | (lan_addr->lun & 0x3);
1788 	smi_msg->data[6] = ipmb_checksum(&smi_msg->data[4], 2);
1789 	smi_msg->data[7] = lan_addr->local_SWID;
1790 	smi_msg->data[8] = (ipmb_seq << 2) | source_lun;
1791 	smi_msg->data[9] = msg->cmd;
1792 
1793 	/* Now tack on the data to the message. */
1794 	if (msg->data_len > 0)
1795 		memcpy(&smi_msg->data[10], msg->data, msg->data_len);
1796 	smi_msg->data_size = msg->data_len + 10;
1797 
1798 	/* Now calculate the checksum and tack it on. */
1799 	smi_msg->data[smi_msg->data_size]
1800 		= ipmb_checksum(&smi_msg->data[7], smi_msg->data_size - 7);
1801 
1802 	/*
1803 	 * Add on the checksum size and the offset from the
1804 	 * broadcast.
1805 	 */
1806 	smi_msg->data_size += 1;
1807 
1808 	smi_msg->msgid = msgid;
1809 }
1810 
1811 static struct ipmi_smi_msg *smi_add_send_msg(struct ipmi_smi *intf,
1812 					     struct ipmi_smi_msg *smi_msg,
1813 					     int priority)
1814 {
1815 	if (intf->curr_msg) {
1816 		if (priority > 0)
1817 			list_add_tail(&smi_msg->link, &intf->hp_xmit_msgs);
1818 		else
1819 			list_add_tail(&smi_msg->link, &intf->xmit_msgs);
1820 		smi_msg = NULL;
1821 	} else {
1822 		intf->curr_msg = smi_msg;
1823 	}
1824 
1825 	return smi_msg;
1826 }
1827 
1828 static void smi_send(struct ipmi_smi *intf,
1829 		     const struct ipmi_smi_handlers *handlers,
1830 		     struct ipmi_smi_msg *smi_msg, int priority)
1831 {
1832 	int run_to_completion = intf->run_to_completion;
1833 	unsigned long flags = 0;
1834 
1835 	if (!run_to_completion)
1836 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
1837 	smi_msg = smi_add_send_msg(intf, smi_msg, priority);
1838 
1839 	if (!run_to_completion)
1840 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
1841 
1842 	if (smi_msg)
1843 		handlers->sender(intf->send_info, smi_msg);
1844 }
1845 
1846 static bool is_maintenance_mode_cmd(struct kernel_ipmi_msg *msg)
1847 {
1848 	return (((msg->netfn == IPMI_NETFN_APP_REQUEST)
1849 		 && ((msg->cmd == IPMI_COLD_RESET_CMD)
1850 		     || (msg->cmd == IPMI_WARM_RESET_CMD)))
1851 		|| (msg->netfn == IPMI_NETFN_FIRMWARE_REQUEST));
1852 }
1853 
1854 static int i_ipmi_req_sysintf(struct ipmi_smi        *intf,
1855 			      struct ipmi_addr       *addr,
1856 			      long                   msgid,
1857 			      struct kernel_ipmi_msg *msg,
1858 			      struct ipmi_smi_msg    *smi_msg,
1859 			      struct ipmi_recv_msg   *recv_msg,
1860 			      int                    retries,
1861 			      unsigned int           retry_time_ms)
1862 {
1863 	struct ipmi_system_interface_addr *smi_addr;
1864 
1865 	if (msg->netfn & 1)
1866 		/* Responses are not allowed to the SMI. */
1867 		return -EINVAL;
1868 
1869 	smi_addr = (struct ipmi_system_interface_addr *) addr;
1870 	if (smi_addr->lun > 3) {
1871 		ipmi_inc_stat(intf, sent_invalid_commands);
1872 		return -EINVAL;
1873 	}
1874 
1875 	memcpy(&recv_msg->addr, smi_addr, sizeof(*smi_addr));
1876 
1877 	if ((msg->netfn == IPMI_NETFN_APP_REQUEST)
1878 	    && ((msg->cmd == IPMI_SEND_MSG_CMD)
1879 		|| (msg->cmd == IPMI_GET_MSG_CMD)
1880 		|| (msg->cmd == IPMI_READ_EVENT_MSG_BUFFER_CMD))) {
1881 		/*
1882 		 * We don't let the user do these, since we manage
1883 		 * the sequence numbers.
1884 		 */
1885 		ipmi_inc_stat(intf, sent_invalid_commands);
1886 		return -EINVAL;
1887 	}
1888 
1889 	if (is_maintenance_mode_cmd(msg)) {
1890 		unsigned long flags;
1891 
1892 		spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
1893 		intf->auto_maintenance_timeout
1894 			= maintenance_mode_timeout_ms;
1895 		if (!intf->maintenance_mode
1896 		    && !intf->maintenance_mode_enable) {
1897 			intf->maintenance_mode_enable = true;
1898 			maintenance_mode_update(intf);
1899 		}
1900 		spin_unlock_irqrestore(&intf->maintenance_mode_lock,
1901 				       flags);
1902 	}
1903 
1904 	if (msg->data_len + 2 > IPMI_MAX_MSG_LENGTH) {
1905 		ipmi_inc_stat(intf, sent_invalid_commands);
1906 		return -EMSGSIZE;
1907 	}
1908 
1909 	smi_msg->data[0] = (msg->netfn << 2) | (smi_addr->lun & 0x3);
1910 	smi_msg->data[1] = msg->cmd;
1911 	smi_msg->msgid = msgid;
1912 	smi_msg->user_data = recv_msg;
1913 	if (msg->data_len > 0)
1914 		memcpy(&smi_msg->data[2], msg->data, msg->data_len);
1915 	smi_msg->data_size = msg->data_len + 2;
1916 	ipmi_inc_stat(intf, sent_local_commands);
1917 
1918 	return 0;
1919 }
1920 
1921 static int i_ipmi_req_ipmb(struct ipmi_smi        *intf,
1922 			   struct ipmi_addr       *addr,
1923 			   long                   msgid,
1924 			   struct kernel_ipmi_msg *msg,
1925 			   struct ipmi_smi_msg    *smi_msg,
1926 			   struct ipmi_recv_msg   *recv_msg,
1927 			   unsigned char          source_address,
1928 			   unsigned char          source_lun,
1929 			   int                    retries,
1930 			   unsigned int           retry_time_ms)
1931 {
1932 	struct ipmi_ipmb_addr *ipmb_addr;
1933 	unsigned char ipmb_seq;
1934 	long seqid;
1935 	int broadcast = 0;
1936 	struct ipmi_channel *chans;
1937 	int rv = 0;
1938 
1939 	if (addr->channel >= IPMI_MAX_CHANNELS) {
1940 		ipmi_inc_stat(intf, sent_invalid_commands);
1941 		return -EINVAL;
1942 	}
1943 
1944 	chans = READ_ONCE(intf->channel_list)->c;
1945 
1946 	if (chans[addr->channel].medium != IPMI_CHANNEL_MEDIUM_IPMB) {
1947 		ipmi_inc_stat(intf, sent_invalid_commands);
1948 		return -EINVAL;
1949 	}
1950 
1951 	if (addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE) {
1952 		/*
1953 		 * Broadcasts add a zero at the beginning of the
1954 		 * message, but otherwise is the same as an IPMB
1955 		 * address.
1956 		 */
1957 		addr->addr_type = IPMI_IPMB_ADDR_TYPE;
1958 		broadcast = 1;
1959 		retries = 0; /* Don't retry broadcasts. */
1960 	}
1961 
1962 	/*
1963 	 * 9 for the header and 1 for the checksum, plus
1964 	 * possibly one for the broadcast.
1965 	 */
1966 	if ((msg->data_len + 10 + broadcast) > IPMI_MAX_MSG_LENGTH) {
1967 		ipmi_inc_stat(intf, sent_invalid_commands);
1968 		return -EMSGSIZE;
1969 	}
1970 
1971 	ipmb_addr = (struct ipmi_ipmb_addr *) addr;
1972 	if (ipmb_addr->lun > 3) {
1973 		ipmi_inc_stat(intf, sent_invalid_commands);
1974 		return -EINVAL;
1975 	}
1976 
1977 	memcpy(&recv_msg->addr, ipmb_addr, sizeof(*ipmb_addr));
1978 
1979 	if (recv_msg->msg.netfn & 0x1) {
1980 		/*
1981 		 * It's a response, so use the user's sequence
1982 		 * from msgid.
1983 		 */
1984 		ipmi_inc_stat(intf, sent_ipmb_responses);
1985 		format_ipmb_msg(smi_msg, msg, ipmb_addr, msgid,
1986 				msgid, broadcast,
1987 				source_address, source_lun);
1988 
1989 		/*
1990 		 * Save the receive message so we can use it
1991 		 * to deliver the response.
1992 		 */
1993 		smi_msg->user_data = recv_msg;
1994 	} else {
1995 		/* It's a command, so get a sequence for it. */
1996 		unsigned long flags;
1997 
1998 		spin_lock_irqsave(&intf->seq_lock, flags);
1999 
2000 		if (is_maintenance_mode_cmd(msg))
2001 			intf->ipmb_maintenance_mode_timeout =
2002 				maintenance_mode_timeout_ms;
2003 
2004 		if (intf->ipmb_maintenance_mode_timeout && retry_time_ms == 0)
2005 			/* Different default in maintenance mode */
2006 			retry_time_ms = default_maintenance_retry_ms;
2007 
2008 		/*
2009 		 * Create a sequence number with a 1 second
2010 		 * timeout and 4 retries.
2011 		 */
2012 		rv = intf_next_seq(intf,
2013 				   recv_msg,
2014 				   retry_time_ms,
2015 				   retries,
2016 				   broadcast,
2017 				   &ipmb_seq,
2018 				   &seqid);
2019 		if (rv)
2020 			/*
2021 			 * We have used up all the sequence numbers,
2022 			 * probably, so abort.
2023 			 */
2024 			goto out_err;
2025 
2026 		ipmi_inc_stat(intf, sent_ipmb_commands);
2027 
2028 		/*
2029 		 * Store the sequence number in the message,
2030 		 * so that when the send message response
2031 		 * comes back we can start the timer.
2032 		 */
2033 		format_ipmb_msg(smi_msg, msg, ipmb_addr,
2034 				STORE_SEQ_IN_MSGID(ipmb_seq, seqid),
2035 				ipmb_seq, broadcast,
2036 				source_address, source_lun);
2037 
2038 		/*
2039 		 * Copy the message into the recv message data, so we
2040 		 * can retransmit it later if necessary.
2041 		 */
2042 		memcpy(recv_msg->msg_data, smi_msg->data,
2043 		       smi_msg->data_size);
2044 		recv_msg->msg.data = recv_msg->msg_data;
2045 		recv_msg->msg.data_len = smi_msg->data_size;
2046 
2047 		/*
2048 		 * We don't unlock until here, because we need
2049 		 * to copy the completed message into the
2050 		 * recv_msg before we release the lock.
2051 		 * Otherwise, race conditions may bite us.  I
2052 		 * know that's pretty paranoid, but I prefer
2053 		 * to be correct.
2054 		 */
2055 out_err:
2056 		spin_unlock_irqrestore(&intf->seq_lock, flags);
2057 	}
2058 
2059 	return rv;
2060 }
2061 
2062 static int i_ipmi_req_lan(struct ipmi_smi        *intf,
2063 			  struct ipmi_addr       *addr,
2064 			  long                   msgid,
2065 			  struct kernel_ipmi_msg *msg,
2066 			  struct ipmi_smi_msg    *smi_msg,
2067 			  struct ipmi_recv_msg   *recv_msg,
2068 			  unsigned char          source_lun,
2069 			  int                    retries,
2070 			  unsigned int           retry_time_ms)
2071 {
2072 	struct ipmi_lan_addr  *lan_addr;
2073 	unsigned char ipmb_seq;
2074 	long seqid;
2075 	struct ipmi_channel *chans;
2076 	int rv = 0;
2077 
2078 	if (addr->channel >= IPMI_MAX_CHANNELS) {
2079 		ipmi_inc_stat(intf, sent_invalid_commands);
2080 		return -EINVAL;
2081 	}
2082 
2083 	chans = READ_ONCE(intf->channel_list)->c;
2084 
2085 	if ((chans[addr->channel].medium
2086 				!= IPMI_CHANNEL_MEDIUM_8023LAN)
2087 			&& (chans[addr->channel].medium
2088 			    != IPMI_CHANNEL_MEDIUM_ASYNC)) {
2089 		ipmi_inc_stat(intf, sent_invalid_commands);
2090 		return -EINVAL;
2091 	}
2092 
2093 	/* 11 for the header and 1 for the checksum. */
2094 	if ((msg->data_len + 12) > IPMI_MAX_MSG_LENGTH) {
2095 		ipmi_inc_stat(intf, sent_invalid_commands);
2096 		return -EMSGSIZE;
2097 	}
2098 
2099 	lan_addr = (struct ipmi_lan_addr *) addr;
2100 	if (lan_addr->lun > 3) {
2101 		ipmi_inc_stat(intf, sent_invalid_commands);
2102 		return -EINVAL;
2103 	}
2104 
2105 	memcpy(&recv_msg->addr, lan_addr, sizeof(*lan_addr));
2106 
2107 	if (recv_msg->msg.netfn & 0x1) {
2108 		/*
2109 		 * It's a response, so use the user's sequence
2110 		 * from msgid.
2111 		 */
2112 		ipmi_inc_stat(intf, sent_lan_responses);
2113 		format_lan_msg(smi_msg, msg, lan_addr, msgid,
2114 			       msgid, source_lun);
2115 
2116 		/*
2117 		 * Save the receive message so we can use it
2118 		 * to deliver the response.
2119 		 */
2120 		smi_msg->user_data = recv_msg;
2121 	} else {
2122 		/* It's a command, so get a sequence for it. */
2123 		unsigned long flags;
2124 
2125 		spin_lock_irqsave(&intf->seq_lock, flags);
2126 
2127 		/*
2128 		 * Create a sequence number with a 1 second
2129 		 * timeout and 4 retries.
2130 		 */
2131 		rv = intf_next_seq(intf,
2132 				   recv_msg,
2133 				   retry_time_ms,
2134 				   retries,
2135 				   0,
2136 				   &ipmb_seq,
2137 				   &seqid);
2138 		if (rv)
2139 			/*
2140 			 * We have used up all the sequence numbers,
2141 			 * probably, so abort.
2142 			 */
2143 			goto out_err;
2144 
2145 		ipmi_inc_stat(intf, sent_lan_commands);
2146 
2147 		/*
2148 		 * Store the sequence number in the message,
2149 		 * so that when the send message response
2150 		 * comes back we can start the timer.
2151 		 */
2152 		format_lan_msg(smi_msg, msg, lan_addr,
2153 			       STORE_SEQ_IN_MSGID(ipmb_seq, seqid),
2154 			       ipmb_seq, source_lun);
2155 
2156 		/*
2157 		 * Copy the message into the recv message data, so we
2158 		 * can retransmit it later if necessary.
2159 		 */
2160 		memcpy(recv_msg->msg_data, smi_msg->data,
2161 		       smi_msg->data_size);
2162 		recv_msg->msg.data = recv_msg->msg_data;
2163 		recv_msg->msg.data_len = smi_msg->data_size;
2164 
2165 		/*
2166 		 * We don't unlock until here, because we need
2167 		 * to copy the completed message into the
2168 		 * recv_msg before we release the lock.
2169 		 * Otherwise, race conditions may bite us.  I
2170 		 * know that's pretty paranoid, but I prefer
2171 		 * to be correct.
2172 		 */
2173 out_err:
2174 		spin_unlock_irqrestore(&intf->seq_lock, flags);
2175 	}
2176 
2177 	return rv;
2178 }
2179 
2180 /*
2181  * Separate from ipmi_request so that the user does not have to be
2182  * supplied in certain circumstances (mainly at panic time).  If
2183  * messages are supplied, they will be freed, even if an error
2184  * occurs.
2185  */
2186 static int i_ipmi_request(struct ipmi_user     *user,
2187 			  struct ipmi_smi      *intf,
2188 			  struct ipmi_addr     *addr,
2189 			  long                 msgid,
2190 			  struct kernel_ipmi_msg *msg,
2191 			  void                 *user_msg_data,
2192 			  void                 *supplied_smi,
2193 			  struct ipmi_recv_msg *supplied_recv,
2194 			  int                  priority,
2195 			  unsigned char        source_address,
2196 			  unsigned char        source_lun,
2197 			  int                  retries,
2198 			  unsigned int         retry_time_ms)
2199 {
2200 	struct ipmi_smi_msg *smi_msg;
2201 	struct ipmi_recv_msg *recv_msg;
2202 	int rv = 0;
2203 
2204 	if (supplied_recv)
2205 		recv_msg = supplied_recv;
2206 	else {
2207 		recv_msg = ipmi_alloc_recv_msg();
2208 		if (recv_msg == NULL) {
2209 			rv = -ENOMEM;
2210 			goto out;
2211 		}
2212 	}
2213 	recv_msg->user_msg_data = user_msg_data;
2214 
2215 	if (supplied_smi)
2216 		smi_msg = (struct ipmi_smi_msg *) supplied_smi;
2217 	else {
2218 		smi_msg = ipmi_alloc_smi_msg();
2219 		if (smi_msg == NULL) {
2220 			if (!supplied_recv)
2221 				ipmi_free_recv_msg(recv_msg);
2222 			rv = -ENOMEM;
2223 			goto out;
2224 		}
2225 	}
2226 
2227 	rcu_read_lock();
2228 	if (intf->in_shutdown) {
2229 		rv = -ENODEV;
2230 		goto out_err;
2231 	}
2232 
2233 	recv_msg->user = user;
2234 	if (user)
2235 		/* The put happens when the message is freed. */
2236 		kref_get(&user->refcount);
2237 	recv_msg->msgid = msgid;
2238 	/*
2239 	 * Store the message to send in the receive message so timeout
2240 	 * responses can get the proper response data.
2241 	 */
2242 	recv_msg->msg = *msg;
2243 
2244 	if (addr->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
2245 		rv = i_ipmi_req_sysintf(intf, addr, msgid, msg, smi_msg,
2246 					recv_msg, retries, retry_time_ms);
2247 	} else if (is_ipmb_addr(addr) || is_ipmb_bcast_addr(addr)) {
2248 		rv = i_ipmi_req_ipmb(intf, addr, msgid, msg, smi_msg, recv_msg,
2249 				     source_address, source_lun,
2250 				     retries, retry_time_ms);
2251 	} else if (is_lan_addr(addr)) {
2252 		rv = i_ipmi_req_lan(intf, addr, msgid, msg, smi_msg, recv_msg,
2253 				    source_lun, retries, retry_time_ms);
2254 	} else {
2255 	    /* Unknown address type. */
2256 		ipmi_inc_stat(intf, sent_invalid_commands);
2257 		rv = -EINVAL;
2258 	}
2259 
2260 	if (rv) {
2261 out_err:
2262 		ipmi_free_smi_msg(smi_msg);
2263 		ipmi_free_recv_msg(recv_msg);
2264 	} else {
2265 		pr_debug("Send: %*ph\n", smi_msg->data_size, smi_msg->data);
2266 
2267 		smi_send(intf, intf->handlers, smi_msg, priority);
2268 	}
2269 	rcu_read_unlock();
2270 
2271 out:
2272 	return rv;
2273 }
2274 
2275 static int check_addr(struct ipmi_smi  *intf,
2276 		      struct ipmi_addr *addr,
2277 		      unsigned char    *saddr,
2278 		      unsigned char    *lun)
2279 {
2280 	if (addr->channel >= IPMI_MAX_CHANNELS)
2281 		return -EINVAL;
2282 	addr->channel = array_index_nospec(addr->channel, IPMI_MAX_CHANNELS);
2283 	*lun = intf->addrinfo[addr->channel].lun;
2284 	*saddr = intf->addrinfo[addr->channel].address;
2285 	return 0;
2286 }
2287 
2288 int ipmi_request_settime(struct ipmi_user *user,
2289 			 struct ipmi_addr *addr,
2290 			 long             msgid,
2291 			 struct kernel_ipmi_msg  *msg,
2292 			 void             *user_msg_data,
2293 			 int              priority,
2294 			 int              retries,
2295 			 unsigned int     retry_time_ms)
2296 {
2297 	unsigned char saddr = 0, lun = 0;
2298 	int rv, index;
2299 
2300 	if (!user)
2301 		return -EINVAL;
2302 
2303 	user = acquire_ipmi_user(user, &index);
2304 	if (!user)
2305 		return -ENODEV;
2306 
2307 	rv = check_addr(user->intf, addr, &saddr, &lun);
2308 	if (!rv)
2309 		rv = i_ipmi_request(user,
2310 				    user->intf,
2311 				    addr,
2312 				    msgid,
2313 				    msg,
2314 				    user_msg_data,
2315 				    NULL, NULL,
2316 				    priority,
2317 				    saddr,
2318 				    lun,
2319 				    retries,
2320 				    retry_time_ms);
2321 
2322 	release_ipmi_user(user, index);
2323 	return rv;
2324 }
2325 EXPORT_SYMBOL(ipmi_request_settime);
2326 
2327 int ipmi_request_supply_msgs(struct ipmi_user     *user,
2328 			     struct ipmi_addr     *addr,
2329 			     long                 msgid,
2330 			     struct kernel_ipmi_msg *msg,
2331 			     void                 *user_msg_data,
2332 			     void                 *supplied_smi,
2333 			     struct ipmi_recv_msg *supplied_recv,
2334 			     int                  priority)
2335 {
2336 	unsigned char saddr = 0, lun = 0;
2337 	int rv, index;
2338 
2339 	if (!user)
2340 		return -EINVAL;
2341 
2342 	user = acquire_ipmi_user(user, &index);
2343 	if (!user)
2344 		return -ENODEV;
2345 
2346 	rv = check_addr(user->intf, addr, &saddr, &lun);
2347 	if (!rv)
2348 		rv = i_ipmi_request(user,
2349 				    user->intf,
2350 				    addr,
2351 				    msgid,
2352 				    msg,
2353 				    user_msg_data,
2354 				    supplied_smi,
2355 				    supplied_recv,
2356 				    priority,
2357 				    saddr,
2358 				    lun,
2359 				    -1, 0);
2360 
2361 	release_ipmi_user(user, index);
2362 	return rv;
2363 }
2364 EXPORT_SYMBOL(ipmi_request_supply_msgs);
2365 
2366 static void bmc_device_id_handler(struct ipmi_smi *intf,
2367 				  struct ipmi_recv_msg *msg)
2368 {
2369 	int rv;
2370 
2371 	if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
2372 			|| (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE)
2373 			|| (msg->msg.cmd != IPMI_GET_DEVICE_ID_CMD)) {
2374 		dev_warn(intf->si_dev,
2375 			 "invalid device_id msg: addr_type=%d netfn=%x cmd=%x\n",
2376 			 msg->addr.addr_type, msg->msg.netfn, msg->msg.cmd);
2377 		return;
2378 	}
2379 
2380 	rv = ipmi_demangle_device_id(msg->msg.netfn, msg->msg.cmd,
2381 			msg->msg.data, msg->msg.data_len, &intf->bmc->fetch_id);
2382 	if (rv) {
2383 		dev_warn(intf->si_dev, "device id demangle failed: %d\n", rv);
2384 		intf->bmc->dyn_id_set = 0;
2385 	} else {
2386 		/*
2387 		 * Make sure the id data is available before setting
2388 		 * dyn_id_set.
2389 		 */
2390 		smp_wmb();
2391 		intf->bmc->dyn_id_set = 1;
2392 	}
2393 
2394 	wake_up(&intf->waitq);
2395 }
2396 
2397 static int
2398 send_get_device_id_cmd(struct ipmi_smi *intf)
2399 {
2400 	struct ipmi_system_interface_addr si;
2401 	struct kernel_ipmi_msg msg;
2402 
2403 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
2404 	si.channel = IPMI_BMC_CHANNEL;
2405 	si.lun = 0;
2406 
2407 	msg.netfn = IPMI_NETFN_APP_REQUEST;
2408 	msg.cmd = IPMI_GET_DEVICE_ID_CMD;
2409 	msg.data = NULL;
2410 	msg.data_len = 0;
2411 
2412 	return i_ipmi_request(NULL,
2413 			      intf,
2414 			      (struct ipmi_addr *) &si,
2415 			      0,
2416 			      &msg,
2417 			      intf,
2418 			      NULL,
2419 			      NULL,
2420 			      0,
2421 			      intf->addrinfo[0].address,
2422 			      intf->addrinfo[0].lun,
2423 			      -1, 0);
2424 }
2425 
2426 static int __get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc)
2427 {
2428 	int rv;
2429 
2430 	bmc->dyn_id_set = 2;
2431 
2432 	intf->null_user_handler = bmc_device_id_handler;
2433 
2434 	rv = send_get_device_id_cmd(intf);
2435 	if (rv)
2436 		return rv;
2437 
2438 	wait_event(intf->waitq, bmc->dyn_id_set != 2);
2439 
2440 	if (!bmc->dyn_id_set)
2441 		rv = -EIO; /* Something went wrong in the fetch. */
2442 
2443 	/* dyn_id_set makes the id data available. */
2444 	smp_rmb();
2445 
2446 	intf->null_user_handler = NULL;
2447 
2448 	return rv;
2449 }
2450 
2451 /*
2452  * Fetch the device id for the bmc/interface.  You must pass in either
2453  * bmc or intf, this code will get the other one.  If the data has
2454  * been recently fetched, this will just use the cached data.  Otherwise
2455  * it will run a new fetch.
2456  *
2457  * Except for the first time this is called (in ipmi_add_smi()),
2458  * this will always return good data;
2459  */
2460 static int __bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
2461 			       struct ipmi_device_id *id,
2462 			       bool *guid_set, guid_t *guid, int intf_num)
2463 {
2464 	int rv = 0;
2465 	int prev_dyn_id_set, prev_guid_set;
2466 	bool intf_set = intf != NULL;
2467 
2468 	if (!intf) {
2469 		mutex_lock(&bmc->dyn_mutex);
2470 retry_bmc_lock:
2471 		if (list_empty(&bmc->intfs)) {
2472 			mutex_unlock(&bmc->dyn_mutex);
2473 			return -ENOENT;
2474 		}
2475 		intf = list_first_entry(&bmc->intfs, struct ipmi_smi,
2476 					bmc_link);
2477 		kref_get(&intf->refcount);
2478 		mutex_unlock(&bmc->dyn_mutex);
2479 		mutex_lock(&intf->bmc_reg_mutex);
2480 		mutex_lock(&bmc->dyn_mutex);
2481 		if (intf != list_first_entry(&bmc->intfs, struct ipmi_smi,
2482 					     bmc_link)) {
2483 			mutex_unlock(&intf->bmc_reg_mutex);
2484 			kref_put(&intf->refcount, intf_free);
2485 			goto retry_bmc_lock;
2486 		}
2487 	} else {
2488 		mutex_lock(&intf->bmc_reg_mutex);
2489 		bmc = intf->bmc;
2490 		mutex_lock(&bmc->dyn_mutex);
2491 		kref_get(&intf->refcount);
2492 	}
2493 
2494 	/* If we have a valid and current ID, just return that. */
2495 	if (intf->in_bmc_register ||
2496 	    (bmc->dyn_id_set && time_is_after_jiffies(bmc->dyn_id_expiry)))
2497 		goto out_noprocessing;
2498 
2499 	prev_guid_set = bmc->dyn_guid_set;
2500 	__get_guid(intf);
2501 
2502 	prev_dyn_id_set = bmc->dyn_id_set;
2503 	rv = __get_device_id(intf, bmc);
2504 	if (rv)
2505 		goto out;
2506 
2507 	/*
2508 	 * The guid, device id, manufacturer id, and product id should
2509 	 * not change on a BMC.  If it does we have to do some dancing.
2510 	 */
2511 	if (!intf->bmc_registered
2512 	    || (!prev_guid_set && bmc->dyn_guid_set)
2513 	    || (!prev_dyn_id_set && bmc->dyn_id_set)
2514 	    || (prev_guid_set && bmc->dyn_guid_set
2515 		&& !guid_equal(&bmc->guid, &bmc->fetch_guid))
2516 	    || bmc->id.device_id != bmc->fetch_id.device_id
2517 	    || bmc->id.manufacturer_id != bmc->fetch_id.manufacturer_id
2518 	    || bmc->id.product_id != bmc->fetch_id.product_id) {
2519 		struct ipmi_device_id id = bmc->fetch_id;
2520 		int guid_set = bmc->dyn_guid_set;
2521 		guid_t guid;
2522 
2523 		guid = bmc->fetch_guid;
2524 		mutex_unlock(&bmc->dyn_mutex);
2525 
2526 		__ipmi_bmc_unregister(intf);
2527 		/* Fill in the temporary BMC for good measure. */
2528 		intf->bmc->id = id;
2529 		intf->bmc->dyn_guid_set = guid_set;
2530 		intf->bmc->guid = guid;
2531 		if (__ipmi_bmc_register(intf, &id, guid_set, &guid, intf_num))
2532 			need_waiter(intf); /* Retry later on an error. */
2533 		else
2534 			__scan_channels(intf, &id);
2535 
2536 
2537 		if (!intf_set) {
2538 			/*
2539 			 * We weren't given the interface on the
2540 			 * command line, so restart the operation on
2541 			 * the next interface for the BMC.
2542 			 */
2543 			mutex_unlock(&intf->bmc_reg_mutex);
2544 			mutex_lock(&bmc->dyn_mutex);
2545 			goto retry_bmc_lock;
2546 		}
2547 
2548 		/* We have a new BMC, set it up. */
2549 		bmc = intf->bmc;
2550 		mutex_lock(&bmc->dyn_mutex);
2551 		goto out_noprocessing;
2552 	} else if (memcmp(&bmc->fetch_id, &bmc->id, sizeof(bmc->id)))
2553 		/* Version info changes, scan the channels again. */
2554 		__scan_channels(intf, &bmc->fetch_id);
2555 
2556 	bmc->dyn_id_expiry = jiffies + IPMI_DYN_DEV_ID_EXPIRY;
2557 
2558 out:
2559 	if (rv && prev_dyn_id_set) {
2560 		rv = 0; /* Ignore failures if we have previous data. */
2561 		bmc->dyn_id_set = prev_dyn_id_set;
2562 	}
2563 	if (!rv) {
2564 		bmc->id = bmc->fetch_id;
2565 		if (bmc->dyn_guid_set)
2566 			bmc->guid = bmc->fetch_guid;
2567 		else if (prev_guid_set)
2568 			/*
2569 			 * The guid used to be valid and it failed to fetch,
2570 			 * just use the cached value.
2571 			 */
2572 			bmc->dyn_guid_set = prev_guid_set;
2573 	}
2574 out_noprocessing:
2575 	if (!rv) {
2576 		if (id)
2577 			*id = bmc->id;
2578 
2579 		if (guid_set)
2580 			*guid_set = bmc->dyn_guid_set;
2581 
2582 		if (guid && bmc->dyn_guid_set)
2583 			*guid =  bmc->guid;
2584 	}
2585 
2586 	mutex_unlock(&bmc->dyn_mutex);
2587 	mutex_unlock(&intf->bmc_reg_mutex);
2588 
2589 	kref_put(&intf->refcount, intf_free);
2590 	return rv;
2591 }
2592 
2593 static int bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
2594 			     struct ipmi_device_id *id,
2595 			     bool *guid_set, guid_t *guid)
2596 {
2597 	return __bmc_get_device_id(intf, bmc, id, guid_set, guid, -1);
2598 }
2599 
2600 static ssize_t device_id_show(struct device *dev,
2601 			      struct device_attribute *attr,
2602 			      char *buf)
2603 {
2604 	struct bmc_device *bmc = to_bmc_device(dev);
2605 	struct ipmi_device_id id;
2606 	int rv;
2607 
2608 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2609 	if (rv)
2610 		return rv;
2611 
2612 	return snprintf(buf, 10, "%u\n", id.device_id);
2613 }
2614 static DEVICE_ATTR_RO(device_id);
2615 
2616 static ssize_t provides_device_sdrs_show(struct device *dev,
2617 					 struct device_attribute *attr,
2618 					 char *buf)
2619 {
2620 	struct bmc_device *bmc = to_bmc_device(dev);
2621 	struct ipmi_device_id id;
2622 	int rv;
2623 
2624 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2625 	if (rv)
2626 		return rv;
2627 
2628 	return snprintf(buf, 10, "%u\n", (id.device_revision & 0x80) >> 7);
2629 }
2630 static DEVICE_ATTR_RO(provides_device_sdrs);
2631 
2632 static ssize_t revision_show(struct device *dev, struct device_attribute *attr,
2633 			     char *buf)
2634 {
2635 	struct bmc_device *bmc = to_bmc_device(dev);
2636 	struct ipmi_device_id id;
2637 	int rv;
2638 
2639 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2640 	if (rv)
2641 		return rv;
2642 
2643 	return snprintf(buf, 20, "%u\n", id.device_revision & 0x0F);
2644 }
2645 static DEVICE_ATTR_RO(revision);
2646 
2647 static ssize_t firmware_revision_show(struct device *dev,
2648 				      struct device_attribute *attr,
2649 				      char *buf)
2650 {
2651 	struct bmc_device *bmc = to_bmc_device(dev);
2652 	struct ipmi_device_id id;
2653 	int rv;
2654 
2655 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2656 	if (rv)
2657 		return rv;
2658 
2659 	return snprintf(buf, 20, "%u.%x\n", id.firmware_revision_1,
2660 			id.firmware_revision_2);
2661 }
2662 static DEVICE_ATTR_RO(firmware_revision);
2663 
2664 static ssize_t ipmi_version_show(struct device *dev,
2665 				 struct device_attribute *attr,
2666 				 char *buf)
2667 {
2668 	struct bmc_device *bmc = to_bmc_device(dev);
2669 	struct ipmi_device_id id;
2670 	int rv;
2671 
2672 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2673 	if (rv)
2674 		return rv;
2675 
2676 	return snprintf(buf, 20, "%u.%u\n",
2677 			ipmi_version_major(&id),
2678 			ipmi_version_minor(&id));
2679 }
2680 static DEVICE_ATTR_RO(ipmi_version);
2681 
2682 static ssize_t add_dev_support_show(struct device *dev,
2683 				    struct device_attribute *attr,
2684 				    char *buf)
2685 {
2686 	struct bmc_device *bmc = to_bmc_device(dev);
2687 	struct ipmi_device_id id;
2688 	int rv;
2689 
2690 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2691 	if (rv)
2692 		return rv;
2693 
2694 	return snprintf(buf, 10, "0x%02x\n", id.additional_device_support);
2695 }
2696 static DEVICE_ATTR(additional_device_support, S_IRUGO, add_dev_support_show,
2697 		   NULL);
2698 
2699 static ssize_t manufacturer_id_show(struct device *dev,
2700 				    struct device_attribute *attr,
2701 				    char *buf)
2702 {
2703 	struct bmc_device *bmc = to_bmc_device(dev);
2704 	struct ipmi_device_id id;
2705 	int rv;
2706 
2707 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2708 	if (rv)
2709 		return rv;
2710 
2711 	return snprintf(buf, 20, "0x%6.6x\n", id.manufacturer_id);
2712 }
2713 static DEVICE_ATTR_RO(manufacturer_id);
2714 
2715 static ssize_t product_id_show(struct device *dev,
2716 			       struct device_attribute *attr,
2717 			       char *buf)
2718 {
2719 	struct bmc_device *bmc = to_bmc_device(dev);
2720 	struct ipmi_device_id id;
2721 	int rv;
2722 
2723 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2724 	if (rv)
2725 		return rv;
2726 
2727 	return snprintf(buf, 10, "0x%4.4x\n", id.product_id);
2728 }
2729 static DEVICE_ATTR_RO(product_id);
2730 
2731 static ssize_t aux_firmware_rev_show(struct device *dev,
2732 				     struct device_attribute *attr,
2733 				     char *buf)
2734 {
2735 	struct bmc_device *bmc = to_bmc_device(dev);
2736 	struct ipmi_device_id id;
2737 	int rv;
2738 
2739 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2740 	if (rv)
2741 		return rv;
2742 
2743 	return snprintf(buf, 21, "0x%02x 0x%02x 0x%02x 0x%02x\n",
2744 			id.aux_firmware_revision[3],
2745 			id.aux_firmware_revision[2],
2746 			id.aux_firmware_revision[1],
2747 			id.aux_firmware_revision[0]);
2748 }
2749 static DEVICE_ATTR(aux_firmware_revision, S_IRUGO, aux_firmware_rev_show, NULL);
2750 
2751 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
2752 			 char *buf)
2753 {
2754 	struct bmc_device *bmc = to_bmc_device(dev);
2755 	bool guid_set;
2756 	guid_t guid;
2757 	int rv;
2758 
2759 	rv = bmc_get_device_id(NULL, bmc, NULL, &guid_set, &guid);
2760 	if (rv)
2761 		return rv;
2762 	if (!guid_set)
2763 		return -ENOENT;
2764 
2765 	return snprintf(buf, UUID_STRING_LEN + 1 + 1, "%pUl\n", &guid);
2766 }
2767 static DEVICE_ATTR_RO(guid);
2768 
2769 static struct attribute *bmc_dev_attrs[] = {
2770 	&dev_attr_device_id.attr,
2771 	&dev_attr_provides_device_sdrs.attr,
2772 	&dev_attr_revision.attr,
2773 	&dev_attr_firmware_revision.attr,
2774 	&dev_attr_ipmi_version.attr,
2775 	&dev_attr_additional_device_support.attr,
2776 	&dev_attr_manufacturer_id.attr,
2777 	&dev_attr_product_id.attr,
2778 	&dev_attr_aux_firmware_revision.attr,
2779 	&dev_attr_guid.attr,
2780 	NULL
2781 };
2782 
2783 static umode_t bmc_dev_attr_is_visible(struct kobject *kobj,
2784 				       struct attribute *attr, int idx)
2785 {
2786 	struct device *dev = kobj_to_dev(kobj);
2787 	struct bmc_device *bmc = to_bmc_device(dev);
2788 	umode_t mode = attr->mode;
2789 	int rv;
2790 
2791 	if (attr == &dev_attr_aux_firmware_revision.attr) {
2792 		struct ipmi_device_id id;
2793 
2794 		rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2795 		return (!rv && id.aux_firmware_revision_set) ? mode : 0;
2796 	}
2797 	if (attr == &dev_attr_guid.attr) {
2798 		bool guid_set;
2799 
2800 		rv = bmc_get_device_id(NULL, bmc, NULL, &guid_set, NULL);
2801 		return (!rv && guid_set) ? mode : 0;
2802 	}
2803 	return mode;
2804 }
2805 
2806 static const struct attribute_group bmc_dev_attr_group = {
2807 	.attrs		= bmc_dev_attrs,
2808 	.is_visible	= bmc_dev_attr_is_visible,
2809 };
2810 
2811 static const struct attribute_group *bmc_dev_attr_groups[] = {
2812 	&bmc_dev_attr_group,
2813 	NULL
2814 };
2815 
2816 static const struct device_type bmc_device_type = {
2817 	.groups		= bmc_dev_attr_groups,
2818 };
2819 
2820 static int __find_bmc_guid(struct device *dev, const void *data)
2821 {
2822 	const guid_t *guid = data;
2823 	struct bmc_device *bmc;
2824 	int rv;
2825 
2826 	if (dev->type != &bmc_device_type)
2827 		return 0;
2828 
2829 	bmc = to_bmc_device(dev);
2830 	rv = bmc->dyn_guid_set && guid_equal(&bmc->guid, guid);
2831 	if (rv)
2832 		rv = kref_get_unless_zero(&bmc->usecount);
2833 	return rv;
2834 }
2835 
2836 /*
2837  * Returns with the bmc's usecount incremented, if it is non-NULL.
2838  */
2839 static struct bmc_device *ipmi_find_bmc_guid(struct device_driver *drv,
2840 					     guid_t *guid)
2841 {
2842 	struct device *dev;
2843 	struct bmc_device *bmc = NULL;
2844 
2845 	dev = driver_find_device(drv, NULL, guid, __find_bmc_guid);
2846 	if (dev) {
2847 		bmc = to_bmc_device(dev);
2848 		put_device(dev);
2849 	}
2850 	return bmc;
2851 }
2852 
2853 struct prod_dev_id {
2854 	unsigned int  product_id;
2855 	unsigned char device_id;
2856 };
2857 
2858 static int __find_bmc_prod_dev_id(struct device *dev, const void *data)
2859 {
2860 	const struct prod_dev_id *cid = data;
2861 	struct bmc_device *bmc;
2862 	int rv;
2863 
2864 	if (dev->type != &bmc_device_type)
2865 		return 0;
2866 
2867 	bmc = to_bmc_device(dev);
2868 	rv = (bmc->id.product_id == cid->product_id
2869 	      && bmc->id.device_id == cid->device_id);
2870 	if (rv)
2871 		rv = kref_get_unless_zero(&bmc->usecount);
2872 	return rv;
2873 }
2874 
2875 /*
2876  * Returns with the bmc's usecount incremented, if it is non-NULL.
2877  */
2878 static struct bmc_device *ipmi_find_bmc_prod_dev_id(
2879 	struct device_driver *drv,
2880 	unsigned int product_id, unsigned char device_id)
2881 {
2882 	struct prod_dev_id id = {
2883 		.product_id = product_id,
2884 		.device_id = device_id,
2885 	};
2886 	struct device *dev;
2887 	struct bmc_device *bmc = NULL;
2888 
2889 	dev = driver_find_device(drv, NULL, &id, __find_bmc_prod_dev_id);
2890 	if (dev) {
2891 		bmc = to_bmc_device(dev);
2892 		put_device(dev);
2893 	}
2894 	return bmc;
2895 }
2896 
2897 static DEFINE_IDA(ipmi_bmc_ida);
2898 
2899 static void
2900 release_bmc_device(struct device *dev)
2901 {
2902 	kfree(to_bmc_device(dev));
2903 }
2904 
2905 static void cleanup_bmc_work(struct work_struct *work)
2906 {
2907 	struct bmc_device *bmc = container_of(work, struct bmc_device,
2908 					      remove_work);
2909 	int id = bmc->pdev.id; /* Unregister overwrites id */
2910 
2911 	platform_device_unregister(&bmc->pdev);
2912 	ida_simple_remove(&ipmi_bmc_ida, id);
2913 }
2914 
2915 static void
2916 cleanup_bmc_device(struct kref *ref)
2917 {
2918 	struct bmc_device *bmc = container_of(ref, struct bmc_device, usecount);
2919 
2920 	/*
2921 	 * Remove the platform device in a work queue to avoid issues
2922 	 * with removing the device attributes while reading a device
2923 	 * attribute.
2924 	 */
2925 	schedule_work(&bmc->remove_work);
2926 }
2927 
2928 /*
2929  * Must be called with intf->bmc_reg_mutex held.
2930  */
2931 static void __ipmi_bmc_unregister(struct ipmi_smi *intf)
2932 {
2933 	struct bmc_device *bmc = intf->bmc;
2934 
2935 	if (!intf->bmc_registered)
2936 		return;
2937 
2938 	sysfs_remove_link(&intf->si_dev->kobj, "bmc");
2939 	sysfs_remove_link(&bmc->pdev.dev.kobj, intf->my_dev_name);
2940 	kfree(intf->my_dev_name);
2941 	intf->my_dev_name = NULL;
2942 
2943 	mutex_lock(&bmc->dyn_mutex);
2944 	list_del(&intf->bmc_link);
2945 	mutex_unlock(&bmc->dyn_mutex);
2946 	intf->bmc = &intf->tmp_bmc;
2947 	kref_put(&bmc->usecount, cleanup_bmc_device);
2948 	intf->bmc_registered = false;
2949 }
2950 
2951 static void ipmi_bmc_unregister(struct ipmi_smi *intf)
2952 {
2953 	mutex_lock(&intf->bmc_reg_mutex);
2954 	__ipmi_bmc_unregister(intf);
2955 	mutex_unlock(&intf->bmc_reg_mutex);
2956 }
2957 
2958 /*
2959  * Must be called with intf->bmc_reg_mutex held.
2960  */
2961 static int __ipmi_bmc_register(struct ipmi_smi *intf,
2962 			       struct ipmi_device_id *id,
2963 			       bool guid_set, guid_t *guid, int intf_num)
2964 {
2965 	int               rv;
2966 	struct bmc_device *bmc;
2967 	struct bmc_device *old_bmc;
2968 
2969 	/*
2970 	 * platform_device_register() can cause bmc_reg_mutex to
2971 	 * be claimed because of the is_visible functions of
2972 	 * the attributes.  Eliminate possible recursion and
2973 	 * release the lock.
2974 	 */
2975 	intf->in_bmc_register = true;
2976 	mutex_unlock(&intf->bmc_reg_mutex);
2977 
2978 	/*
2979 	 * Try to find if there is an bmc_device struct
2980 	 * representing the interfaced BMC already
2981 	 */
2982 	mutex_lock(&ipmidriver_mutex);
2983 	if (guid_set)
2984 		old_bmc = ipmi_find_bmc_guid(&ipmidriver.driver, guid);
2985 	else
2986 		old_bmc = ipmi_find_bmc_prod_dev_id(&ipmidriver.driver,
2987 						    id->product_id,
2988 						    id->device_id);
2989 
2990 	/*
2991 	 * If there is already an bmc_device, free the new one,
2992 	 * otherwise register the new BMC device
2993 	 */
2994 	if (old_bmc) {
2995 		bmc = old_bmc;
2996 		/*
2997 		 * Note: old_bmc already has usecount incremented by
2998 		 * the BMC find functions.
2999 		 */
3000 		intf->bmc = old_bmc;
3001 		mutex_lock(&bmc->dyn_mutex);
3002 		list_add_tail(&intf->bmc_link, &bmc->intfs);
3003 		mutex_unlock(&bmc->dyn_mutex);
3004 
3005 		dev_info(intf->si_dev,
3006 			 "interfacing existing BMC (man_id: 0x%6.6x, prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n",
3007 			 bmc->id.manufacturer_id,
3008 			 bmc->id.product_id,
3009 			 bmc->id.device_id);
3010 	} else {
3011 		bmc = kzalloc(sizeof(*bmc), GFP_KERNEL);
3012 		if (!bmc) {
3013 			rv = -ENOMEM;
3014 			goto out;
3015 		}
3016 		INIT_LIST_HEAD(&bmc->intfs);
3017 		mutex_init(&bmc->dyn_mutex);
3018 		INIT_WORK(&bmc->remove_work, cleanup_bmc_work);
3019 
3020 		bmc->id = *id;
3021 		bmc->dyn_id_set = 1;
3022 		bmc->dyn_guid_set = guid_set;
3023 		bmc->guid = *guid;
3024 		bmc->dyn_id_expiry = jiffies + IPMI_DYN_DEV_ID_EXPIRY;
3025 
3026 		bmc->pdev.name = "ipmi_bmc";
3027 
3028 		rv = ida_simple_get(&ipmi_bmc_ida, 0, 0, GFP_KERNEL);
3029 		if (rv < 0) {
3030 			kfree(bmc);
3031 			goto out;
3032 		}
3033 
3034 		bmc->pdev.dev.driver = &ipmidriver.driver;
3035 		bmc->pdev.id = rv;
3036 		bmc->pdev.dev.release = release_bmc_device;
3037 		bmc->pdev.dev.type = &bmc_device_type;
3038 		kref_init(&bmc->usecount);
3039 
3040 		intf->bmc = bmc;
3041 		mutex_lock(&bmc->dyn_mutex);
3042 		list_add_tail(&intf->bmc_link, &bmc->intfs);
3043 		mutex_unlock(&bmc->dyn_mutex);
3044 
3045 		rv = platform_device_register(&bmc->pdev);
3046 		if (rv) {
3047 			dev_err(intf->si_dev,
3048 				"Unable to register bmc device: %d\n",
3049 				rv);
3050 			goto out_list_del;
3051 		}
3052 
3053 		dev_info(intf->si_dev,
3054 			 "Found new BMC (man_id: 0x%6.6x, prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n",
3055 			 bmc->id.manufacturer_id,
3056 			 bmc->id.product_id,
3057 			 bmc->id.device_id);
3058 	}
3059 
3060 	/*
3061 	 * create symlink from system interface device to bmc device
3062 	 * and back.
3063 	 */
3064 	rv = sysfs_create_link(&intf->si_dev->kobj, &bmc->pdev.dev.kobj, "bmc");
3065 	if (rv) {
3066 		dev_err(intf->si_dev, "Unable to create bmc symlink: %d\n", rv);
3067 		goto out_put_bmc;
3068 	}
3069 
3070 	if (intf_num == -1)
3071 		intf_num = intf->intf_num;
3072 	intf->my_dev_name = kasprintf(GFP_KERNEL, "ipmi%d", intf_num);
3073 	if (!intf->my_dev_name) {
3074 		rv = -ENOMEM;
3075 		dev_err(intf->si_dev, "Unable to allocate link from BMC: %d\n",
3076 			rv);
3077 		goto out_unlink1;
3078 	}
3079 
3080 	rv = sysfs_create_link(&bmc->pdev.dev.kobj, &intf->si_dev->kobj,
3081 			       intf->my_dev_name);
3082 	if (rv) {
3083 		dev_err(intf->si_dev, "Unable to create symlink to bmc: %d\n",
3084 			rv);
3085 		goto out_free_my_dev_name;
3086 	}
3087 
3088 	intf->bmc_registered = true;
3089 
3090 out:
3091 	mutex_unlock(&ipmidriver_mutex);
3092 	mutex_lock(&intf->bmc_reg_mutex);
3093 	intf->in_bmc_register = false;
3094 	return rv;
3095 
3096 
3097 out_free_my_dev_name:
3098 	kfree(intf->my_dev_name);
3099 	intf->my_dev_name = NULL;
3100 
3101 out_unlink1:
3102 	sysfs_remove_link(&intf->si_dev->kobj, "bmc");
3103 
3104 out_put_bmc:
3105 	mutex_lock(&bmc->dyn_mutex);
3106 	list_del(&intf->bmc_link);
3107 	mutex_unlock(&bmc->dyn_mutex);
3108 	intf->bmc = &intf->tmp_bmc;
3109 	kref_put(&bmc->usecount, cleanup_bmc_device);
3110 	goto out;
3111 
3112 out_list_del:
3113 	mutex_lock(&bmc->dyn_mutex);
3114 	list_del(&intf->bmc_link);
3115 	mutex_unlock(&bmc->dyn_mutex);
3116 	intf->bmc = &intf->tmp_bmc;
3117 	put_device(&bmc->pdev.dev);
3118 	goto out;
3119 }
3120 
3121 static int
3122 send_guid_cmd(struct ipmi_smi *intf, int chan)
3123 {
3124 	struct kernel_ipmi_msg            msg;
3125 	struct ipmi_system_interface_addr si;
3126 
3127 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
3128 	si.channel = IPMI_BMC_CHANNEL;
3129 	si.lun = 0;
3130 
3131 	msg.netfn = IPMI_NETFN_APP_REQUEST;
3132 	msg.cmd = IPMI_GET_DEVICE_GUID_CMD;
3133 	msg.data = NULL;
3134 	msg.data_len = 0;
3135 	return i_ipmi_request(NULL,
3136 			      intf,
3137 			      (struct ipmi_addr *) &si,
3138 			      0,
3139 			      &msg,
3140 			      intf,
3141 			      NULL,
3142 			      NULL,
3143 			      0,
3144 			      intf->addrinfo[0].address,
3145 			      intf->addrinfo[0].lun,
3146 			      -1, 0);
3147 }
3148 
3149 static void guid_handler(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
3150 {
3151 	struct bmc_device *bmc = intf->bmc;
3152 
3153 	if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
3154 	    || (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE)
3155 	    || (msg->msg.cmd != IPMI_GET_DEVICE_GUID_CMD))
3156 		/* Not for me */
3157 		return;
3158 
3159 	if (msg->msg.data[0] != 0) {
3160 		/* Error from getting the GUID, the BMC doesn't have one. */
3161 		bmc->dyn_guid_set = 0;
3162 		goto out;
3163 	}
3164 
3165 	if (msg->msg.data_len < UUID_SIZE + 1) {
3166 		bmc->dyn_guid_set = 0;
3167 		dev_warn(intf->si_dev,
3168 			 "The GUID response from the BMC was too short, it was %d but should have been %d.  Assuming GUID is not available.\n",
3169 			 msg->msg.data_len, UUID_SIZE + 1);
3170 		goto out;
3171 	}
3172 
3173 	import_guid(&bmc->fetch_guid, msg->msg.data + 1);
3174 	/*
3175 	 * Make sure the guid data is available before setting
3176 	 * dyn_guid_set.
3177 	 */
3178 	smp_wmb();
3179 	bmc->dyn_guid_set = 1;
3180  out:
3181 	wake_up(&intf->waitq);
3182 }
3183 
3184 static void __get_guid(struct ipmi_smi *intf)
3185 {
3186 	int rv;
3187 	struct bmc_device *bmc = intf->bmc;
3188 
3189 	bmc->dyn_guid_set = 2;
3190 	intf->null_user_handler = guid_handler;
3191 	rv = send_guid_cmd(intf, 0);
3192 	if (rv)
3193 		/* Send failed, no GUID available. */
3194 		bmc->dyn_guid_set = 0;
3195 	else
3196 		wait_event(intf->waitq, bmc->dyn_guid_set != 2);
3197 
3198 	/* dyn_guid_set makes the guid data available. */
3199 	smp_rmb();
3200 
3201 	intf->null_user_handler = NULL;
3202 }
3203 
3204 static int
3205 send_channel_info_cmd(struct ipmi_smi *intf, int chan)
3206 {
3207 	struct kernel_ipmi_msg            msg;
3208 	unsigned char                     data[1];
3209 	struct ipmi_system_interface_addr si;
3210 
3211 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
3212 	si.channel = IPMI_BMC_CHANNEL;
3213 	si.lun = 0;
3214 
3215 	msg.netfn = IPMI_NETFN_APP_REQUEST;
3216 	msg.cmd = IPMI_GET_CHANNEL_INFO_CMD;
3217 	msg.data = data;
3218 	msg.data_len = 1;
3219 	data[0] = chan;
3220 	return i_ipmi_request(NULL,
3221 			      intf,
3222 			      (struct ipmi_addr *) &si,
3223 			      0,
3224 			      &msg,
3225 			      intf,
3226 			      NULL,
3227 			      NULL,
3228 			      0,
3229 			      intf->addrinfo[0].address,
3230 			      intf->addrinfo[0].lun,
3231 			      -1, 0);
3232 }
3233 
3234 static void
3235 channel_handler(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
3236 {
3237 	int rv = 0;
3238 	int ch;
3239 	unsigned int set = intf->curr_working_cset;
3240 	struct ipmi_channel *chans;
3241 
3242 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
3243 	    && (msg->msg.netfn == IPMI_NETFN_APP_RESPONSE)
3244 	    && (msg->msg.cmd == IPMI_GET_CHANNEL_INFO_CMD)) {
3245 		/* It's the one we want */
3246 		if (msg->msg.data[0] != 0) {
3247 			/* Got an error from the channel, just go on. */
3248 
3249 			if (msg->msg.data[0] == IPMI_INVALID_COMMAND_ERR) {
3250 				/*
3251 				 * If the MC does not support this
3252 				 * command, that is legal.  We just
3253 				 * assume it has one IPMB at channel
3254 				 * zero.
3255 				 */
3256 				intf->wchannels[set].c[0].medium
3257 					= IPMI_CHANNEL_MEDIUM_IPMB;
3258 				intf->wchannels[set].c[0].protocol
3259 					= IPMI_CHANNEL_PROTOCOL_IPMB;
3260 
3261 				intf->channel_list = intf->wchannels + set;
3262 				intf->channels_ready = true;
3263 				wake_up(&intf->waitq);
3264 				goto out;
3265 			}
3266 			goto next_channel;
3267 		}
3268 		if (msg->msg.data_len < 4) {
3269 			/* Message not big enough, just go on. */
3270 			goto next_channel;
3271 		}
3272 		ch = intf->curr_channel;
3273 		chans = intf->wchannels[set].c;
3274 		chans[ch].medium = msg->msg.data[2] & 0x7f;
3275 		chans[ch].protocol = msg->msg.data[3] & 0x1f;
3276 
3277  next_channel:
3278 		intf->curr_channel++;
3279 		if (intf->curr_channel >= IPMI_MAX_CHANNELS) {
3280 			intf->channel_list = intf->wchannels + set;
3281 			intf->channels_ready = true;
3282 			wake_up(&intf->waitq);
3283 		} else {
3284 			intf->channel_list = intf->wchannels + set;
3285 			intf->channels_ready = true;
3286 			rv = send_channel_info_cmd(intf, intf->curr_channel);
3287 		}
3288 
3289 		if (rv) {
3290 			/* Got an error somehow, just give up. */
3291 			dev_warn(intf->si_dev,
3292 				 "Error sending channel information for channel %d: %d\n",
3293 				 intf->curr_channel, rv);
3294 
3295 			intf->channel_list = intf->wchannels + set;
3296 			intf->channels_ready = true;
3297 			wake_up(&intf->waitq);
3298 		}
3299 	}
3300  out:
3301 	return;
3302 }
3303 
3304 /*
3305  * Must be holding intf->bmc_reg_mutex to call this.
3306  */
3307 static int __scan_channels(struct ipmi_smi *intf, struct ipmi_device_id *id)
3308 {
3309 	int rv;
3310 
3311 	if (ipmi_version_major(id) > 1
3312 			|| (ipmi_version_major(id) == 1
3313 			    && ipmi_version_minor(id) >= 5)) {
3314 		unsigned int set;
3315 
3316 		/*
3317 		 * Start scanning the channels to see what is
3318 		 * available.
3319 		 */
3320 		set = !intf->curr_working_cset;
3321 		intf->curr_working_cset = set;
3322 		memset(&intf->wchannels[set], 0,
3323 		       sizeof(struct ipmi_channel_set));
3324 
3325 		intf->null_user_handler = channel_handler;
3326 		intf->curr_channel = 0;
3327 		rv = send_channel_info_cmd(intf, 0);
3328 		if (rv) {
3329 			dev_warn(intf->si_dev,
3330 				 "Error sending channel information for channel 0, %d\n",
3331 				 rv);
3332 			return -EIO;
3333 		}
3334 
3335 		/* Wait for the channel info to be read. */
3336 		wait_event(intf->waitq, intf->channels_ready);
3337 		intf->null_user_handler = NULL;
3338 	} else {
3339 		unsigned int set = intf->curr_working_cset;
3340 
3341 		/* Assume a single IPMB channel at zero. */
3342 		intf->wchannels[set].c[0].medium = IPMI_CHANNEL_MEDIUM_IPMB;
3343 		intf->wchannels[set].c[0].protocol = IPMI_CHANNEL_PROTOCOL_IPMB;
3344 		intf->channel_list = intf->wchannels + set;
3345 		intf->channels_ready = true;
3346 	}
3347 
3348 	return 0;
3349 }
3350 
3351 static void ipmi_poll(struct ipmi_smi *intf)
3352 {
3353 	if (intf->handlers->poll)
3354 		intf->handlers->poll(intf->send_info);
3355 	/* In case something came in */
3356 	handle_new_recv_msgs(intf);
3357 }
3358 
3359 void ipmi_poll_interface(struct ipmi_user *user)
3360 {
3361 	ipmi_poll(user->intf);
3362 }
3363 EXPORT_SYMBOL(ipmi_poll_interface);
3364 
3365 static void redo_bmc_reg(struct work_struct *work)
3366 {
3367 	struct ipmi_smi *intf = container_of(work, struct ipmi_smi,
3368 					     bmc_reg_work);
3369 
3370 	if (!intf->in_shutdown)
3371 		bmc_get_device_id(intf, NULL, NULL, NULL, NULL);
3372 
3373 	kref_put(&intf->refcount, intf_free);
3374 }
3375 
3376 int ipmi_add_smi(struct module         *owner,
3377 		 const struct ipmi_smi_handlers *handlers,
3378 		 void		       *send_info,
3379 		 struct device         *si_dev,
3380 		 unsigned char         slave_addr)
3381 {
3382 	int              i, j;
3383 	int              rv;
3384 	struct ipmi_smi *intf, *tintf;
3385 	struct list_head *link;
3386 	struct ipmi_device_id id;
3387 
3388 	/*
3389 	 * Make sure the driver is actually initialized, this handles
3390 	 * problems with initialization order.
3391 	 */
3392 	rv = ipmi_init_msghandler();
3393 	if (rv)
3394 		return rv;
3395 
3396 	intf = kzalloc(sizeof(*intf), GFP_KERNEL);
3397 	if (!intf)
3398 		return -ENOMEM;
3399 
3400 	rv = init_srcu_struct(&intf->users_srcu);
3401 	if (rv) {
3402 		kfree(intf);
3403 		return rv;
3404 	}
3405 
3406 	intf->owner = owner;
3407 	intf->bmc = &intf->tmp_bmc;
3408 	INIT_LIST_HEAD(&intf->bmc->intfs);
3409 	mutex_init(&intf->bmc->dyn_mutex);
3410 	INIT_LIST_HEAD(&intf->bmc_link);
3411 	mutex_init(&intf->bmc_reg_mutex);
3412 	intf->intf_num = -1; /* Mark it invalid for now. */
3413 	kref_init(&intf->refcount);
3414 	INIT_WORK(&intf->bmc_reg_work, redo_bmc_reg);
3415 	intf->si_dev = si_dev;
3416 	for (j = 0; j < IPMI_MAX_CHANNELS; j++) {
3417 		intf->addrinfo[j].address = IPMI_BMC_SLAVE_ADDR;
3418 		intf->addrinfo[j].lun = 2;
3419 	}
3420 	if (slave_addr != 0)
3421 		intf->addrinfo[0].address = slave_addr;
3422 	INIT_LIST_HEAD(&intf->users);
3423 	intf->handlers = handlers;
3424 	intf->send_info = send_info;
3425 	spin_lock_init(&intf->seq_lock);
3426 	for (j = 0; j < IPMI_IPMB_NUM_SEQ; j++) {
3427 		intf->seq_table[j].inuse = 0;
3428 		intf->seq_table[j].seqid = 0;
3429 	}
3430 	intf->curr_seq = 0;
3431 	spin_lock_init(&intf->waiting_rcv_msgs_lock);
3432 	INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
3433 	tasklet_init(&intf->recv_tasklet,
3434 		     smi_recv_tasklet,
3435 		     (unsigned long) intf);
3436 	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 0);
3437 	spin_lock_init(&intf->xmit_msgs_lock);
3438 	INIT_LIST_HEAD(&intf->xmit_msgs);
3439 	INIT_LIST_HEAD(&intf->hp_xmit_msgs);
3440 	spin_lock_init(&intf->events_lock);
3441 	spin_lock_init(&intf->watch_lock);
3442 	atomic_set(&intf->event_waiters, 0);
3443 	intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
3444 	INIT_LIST_HEAD(&intf->waiting_events);
3445 	intf->waiting_events_count = 0;
3446 	mutex_init(&intf->cmd_rcvrs_mutex);
3447 	spin_lock_init(&intf->maintenance_mode_lock);
3448 	INIT_LIST_HEAD(&intf->cmd_rcvrs);
3449 	init_waitqueue_head(&intf->waitq);
3450 	for (i = 0; i < IPMI_NUM_STATS; i++)
3451 		atomic_set(&intf->stats[i], 0);
3452 
3453 	mutex_lock(&ipmi_interfaces_mutex);
3454 	/* Look for a hole in the numbers. */
3455 	i = 0;
3456 	link = &ipmi_interfaces;
3457 	list_for_each_entry_rcu(tintf, &ipmi_interfaces, link,
3458 				ipmi_interfaces_mutex_held()) {
3459 		if (tintf->intf_num != i) {
3460 			link = &tintf->link;
3461 			break;
3462 		}
3463 		i++;
3464 	}
3465 	/* Add the new interface in numeric order. */
3466 	if (i == 0)
3467 		list_add_rcu(&intf->link, &ipmi_interfaces);
3468 	else
3469 		list_add_tail_rcu(&intf->link, link);
3470 
3471 	rv = handlers->start_processing(send_info, intf);
3472 	if (rv)
3473 		goto out_err;
3474 
3475 	rv = __bmc_get_device_id(intf, NULL, &id, NULL, NULL, i);
3476 	if (rv) {
3477 		dev_err(si_dev, "Unable to get the device id: %d\n", rv);
3478 		goto out_err_started;
3479 	}
3480 
3481 	mutex_lock(&intf->bmc_reg_mutex);
3482 	rv = __scan_channels(intf, &id);
3483 	mutex_unlock(&intf->bmc_reg_mutex);
3484 	if (rv)
3485 		goto out_err_bmc_reg;
3486 
3487 	/*
3488 	 * Keep memory order straight for RCU readers.  Make
3489 	 * sure everything else is committed to memory before
3490 	 * setting intf_num to mark the interface valid.
3491 	 */
3492 	smp_wmb();
3493 	intf->intf_num = i;
3494 	mutex_unlock(&ipmi_interfaces_mutex);
3495 
3496 	/* After this point the interface is legal to use. */
3497 	call_smi_watchers(i, intf->si_dev);
3498 
3499 	return 0;
3500 
3501  out_err_bmc_reg:
3502 	ipmi_bmc_unregister(intf);
3503  out_err_started:
3504 	if (intf->handlers->shutdown)
3505 		intf->handlers->shutdown(intf->send_info);
3506  out_err:
3507 	list_del_rcu(&intf->link);
3508 	mutex_unlock(&ipmi_interfaces_mutex);
3509 	synchronize_srcu(&ipmi_interfaces_srcu);
3510 	cleanup_srcu_struct(&intf->users_srcu);
3511 	kref_put(&intf->refcount, intf_free);
3512 
3513 	return rv;
3514 }
3515 EXPORT_SYMBOL(ipmi_add_smi);
3516 
3517 static void deliver_smi_err_response(struct ipmi_smi *intf,
3518 				     struct ipmi_smi_msg *msg,
3519 				     unsigned char err)
3520 {
3521 	msg->rsp[0] = msg->data[0] | 4;
3522 	msg->rsp[1] = msg->data[1];
3523 	msg->rsp[2] = err;
3524 	msg->rsp_size = 3;
3525 	/* It's an error, so it will never requeue, no need to check return. */
3526 	handle_one_recv_msg(intf, msg);
3527 }
3528 
3529 static void cleanup_smi_msgs(struct ipmi_smi *intf)
3530 {
3531 	int              i;
3532 	struct seq_table *ent;
3533 	struct ipmi_smi_msg *msg;
3534 	struct list_head *entry;
3535 	struct list_head tmplist;
3536 
3537 	/* Clear out our transmit queues and hold the messages. */
3538 	INIT_LIST_HEAD(&tmplist);
3539 	list_splice_tail(&intf->hp_xmit_msgs, &tmplist);
3540 	list_splice_tail(&intf->xmit_msgs, &tmplist);
3541 
3542 	/* Current message first, to preserve order */
3543 	while (intf->curr_msg && !list_empty(&intf->waiting_rcv_msgs)) {
3544 		/* Wait for the message to clear out. */
3545 		schedule_timeout(1);
3546 	}
3547 
3548 	/* No need for locks, the interface is down. */
3549 
3550 	/*
3551 	 * Return errors for all pending messages in queue and in the
3552 	 * tables waiting for remote responses.
3553 	 */
3554 	while (!list_empty(&tmplist)) {
3555 		entry = tmplist.next;
3556 		list_del(entry);
3557 		msg = list_entry(entry, struct ipmi_smi_msg, link);
3558 		deliver_smi_err_response(intf, msg, IPMI_ERR_UNSPECIFIED);
3559 	}
3560 
3561 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
3562 		ent = &intf->seq_table[i];
3563 		if (!ent->inuse)
3564 			continue;
3565 		deliver_err_response(intf, ent->recv_msg, IPMI_ERR_UNSPECIFIED);
3566 	}
3567 }
3568 
3569 void ipmi_unregister_smi(struct ipmi_smi *intf)
3570 {
3571 	struct ipmi_smi_watcher *w;
3572 	int intf_num = intf->intf_num, index;
3573 
3574 	mutex_lock(&ipmi_interfaces_mutex);
3575 	intf->intf_num = -1;
3576 	intf->in_shutdown = true;
3577 	list_del_rcu(&intf->link);
3578 	mutex_unlock(&ipmi_interfaces_mutex);
3579 	synchronize_srcu(&ipmi_interfaces_srcu);
3580 
3581 	/* At this point no users can be added to the interface. */
3582 
3583 	/*
3584 	 * Call all the watcher interfaces to tell them that
3585 	 * an interface is going away.
3586 	 */
3587 	mutex_lock(&smi_watchers_mutex);
3588 	list_for_each_entry(w, &smi_watchers, link)
3589 		w->smi_gone(intf_num);
3590 	mutex_unlock(&smi_watchers_mutex);
3591 
3592 	index = srcu_read_lock(&intf->users_srcu);
3593 	while (!list_empty(&intf->users)) {
3594 		struct ipmi_user *user =
3595 			container_of(list_next_rcu(&intf->users),
3596 				     struct ipmi_user, link);
3597 
3598 		_ipmi_destroy_user(user);
3599 	}
3600 	srcu_read_unlock(&intf->users_srcu, index);
3601 
3602 	if (intf->handlers->shutdown)
3603 		intf->handlers->shutdown(intf->send_info);
3604 
3605 	cleanup_smi_msgs(intf);
3606 
3607 	ipmi_bmc_unregister(intf);
3608 
3609 	cleanup_srcu_struct(&intf->users_srcu);
3610 	kref_put(&intf->refcount, intf_free);
3611 }
3612 EXPORT_SYMBOL(ipmi_unregister_smi);
3613 
3614 static int handle_ipmb_get_msg_rsp(struct ipmi_smi *intf,
3615 				   struct ipmi_smi_msg *msg)
3616 {
3617 	struct ipmi_ipmb_addr ipmb_addr;
3618 	struct ipmi_recv_msg  *recv_msg;
3619 
3620 	/*
3621 	 * This is 11, not 10, because the response must contain a
3622 	 * completion code.
3623 	 */
3624 	if (msg->rsp_size < 11) {
3625 		/* Message not big enough, just ignore it. */
3626 		ipmi_inc_stat(intf, invalid_ipmb_responses);
3627 		return 0;
3628 	}
3629 
3630 	if (msg->rsp[2] != 0) {
3631 		/* An error getting the response, just ignore it. */
3632 		return 0;
3633 	}
3634 
3635 	ipmb_addr.addr_type = IPMI_IPMB_ADDR_TYPE;
3636 	ipmb_addr.slave_addr = msg->rsp[6];
3637 	ipmb_addr.channel = msg->rsp[3] & 0x0f;
3638 	ipmb_addr.lun = msg->rsp[7] & 3;
3639 
3640 	/*
3641 	 * It's a response from a remote entity.  Look up the sequence
3642 	 * number and handle the response.
3643 	 */
3644 	if (intf_find_seq(intf,
3645 			  msg->rsp[7] >> 2,
3646 			  msg->rsp[3] & 0x0f,
3647 			  msg->rsp[8],
3648 			  (msg->rsp[4] >> 2) & (~1),
3649 			  (struct ipmi_addr *) &ipmb_addr,
3650 			  &recv_msg)) {
3651 		/*
3652 		 * We were unable to find the sequence number,
3653 		 * so just nuke the message.
3654 		 */
3655 		ipmi_inc_stat(intf, unhandled_ipmb_responses);
3656 		return 0;
3657 	}
3658 
3659 	memcpy(recv_msg->msg_data, &msg->rsp[9], msg->rsp_size - 9);
3660 	/*
3661 	 * The other fields matched, so no need to set them, except
3662 	 * for netfn, which needs to be the response that was
3663 	 * returned, not the request value.
3664 	 */
3665 	recv_msg->msg.netfn = msg->rsp[4] >> 2;
3666 	recv_msg->msg.data = recv_msg->msg_data;
3667 	recv_msg->msg.data_len = msg->rsp_size - 10;
3668 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
3669 	if (deliver_response(intf, recv_msg))
3670 		ipmi_inc_stat(intf, unhandled_ipmb_responses);
3671 	else
3672 		ipmi_inc_stat(intf, handled_ipmb_responses);
3673 
3674 	return 0;
3675 }
3676 
3677 static int handle_ipmb_get_msg_cmd(struct ipmi_smi *intf,
3678 				   struct ipmi_smi_msg *msg)
3679 {
3680 	struct cmd_rcvr          *rcvr;
3681 	int                      rv = 0;
3682 	unsigned char            netfn;
3683 	unsigned char            cmd;
3684 	unsigned char            chan;
3685 	struct ipmi_user         *user = NULL;
3686 	struct ipmi_ipmb_addr    *ipmb_addr;
3687 	struct ipmi_recv_msg     *recv_msg;
3688 
3689 	if (msg->rsp_size < 10) {
3690 		/* Message not big enough, just ignore it. */
3691 		ipmi_inc_stat(intf, invalid_commands);
3692 		return 0;
3693 	}
3694 
3695 	if (msg->rsp[2] != 0) {
3696 		/* An error getting the response, just ignore it. */
3697 		return 0;
3698 	}
3699 
3700 	netfn = msg->rsp[4] >> 2;
3701 	cmd = msg->rsp[8];
3702 	chan = msg->rsp[3] & 0xf;
3703 
3704 	rcu_read_lock();
3705 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
3706 	if (rcvr) {
3707 		user = rcvr->user;
3708 		kref_get(&user->refcount);
3709 	} else
3710 		user = NULL;
3711 	rcu_read_unlock();
3712 
3713 	if (user == NULL) {
3714 		/* We didn't find a user, deliver an error response. */
3715 		ipmi_inc_stat(intf, unhandled_commands);
3716 
3717 		msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
3718 		msg->data[1] = IPMI_SEND_MSG_CMD;
3719 		msg->data[2] = msg->rsp[3];
3720 		msg->data[3] = msg->rsp[6];
3721 		msg->data[4] = ((netfn + 1) << 2) | (msg->rsp[7] & 0x3);
3722 		msg->data[5] = ipmb_checksum(&msg->data[3], 2);
3723 		msg->data[6] = intf->addrinfo[msg->rsp[3] & 0xf].address;
3724 		/* rqseq/lun */
3725 		msg->data[7] = (msg->rsp[7] & 0xfc) | (msg->rsp[4] & 0x3);
3726 		msg->data[8] = msg->rsp[8]; /* cmd */
3727 		msg->data[9] = IPMI_INVALID_CMD_COMPLETION_CODE;
3728 		msg->data[10] = ipmb_checksum(&msg->data[6], 4);
3729 		msg->data_size = 11;
3730 
3731 		pr_debug("Invalid command: %*ph\n", msg->data_size, msg->data);
3732 
3733 		rcu_read_lock();
3734 		if (!intf->in_shutdown) {
3735 			smi_send(intf, intf->handlers, msg, 0);
3736 			/*
3737 			 * We used the message, so return the value
3738 			 * that causes it to not be freed or
3739 			 * queued.
3740 			 */
3741 			rv = -1;
3742 		}
3743 		rcu_read_unlock();
3744 	} else {
3745 		recv_msg = ipmi_alloc_recv_msg();
3746 		if (!recv_msg) {
3747 			/*
3748 			 * We couldn't allocate memory for the
3749 			 * message, so requeue it for handling
3750 			 * later.
3751 			 */
3752 			rv = 1;
3753 			kref_put(&user->refcount, free_user);
3754 		} else {
3755 			/* Extract the source address from the data. */
3756 			ipmb_addr = (struct ipmi_ipmb_addr *) &recv_msg->addr;
3757 			ipmb_addr->addr_type = IPMI_IPMB_ADDR_TYPE;
3758 			ipmb_addr->slave_addr = msg->rsp[6];
3759 			ipmb_addr->lun = msg->rsp[7] & 3;
3760 			ipmb_addr->channel = msg->rsp[3] & 0xf;
3761 
3762 			/*
3763 			 * Extract the rest of the message information
3764 			 * from the IPMB header.
3765 			 */
3766 			recv_msg->user = user;
3767 			recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
3768 			recv_msg->msgid = msg->rsp[7] >> 2;
3769 			recv_msg->msg.netfn = msg->rsp[4] >> 2;
3770 			recv_msg->msg.cmd = msg->rsp[8];
3771 			recv_msg->msg.data = recv_msg->msg_data;
3772 
3773 			/*
3774 			 * We chop off 10, not 9 bytes because the checksum
3775 			 * at the end also needs to be removed.
3776 			 */
3777 			recv_msg->msg.data_len = msg->rsp_size - 10;
3778 			memcpy(recv_msg->msg_data, &msg->rsp[9],
3779 			       msg->rsp_size - 10);
3780 			if (deliver_response(intf, recv_msg))
3781 				ipmi_inc_stat(intf, unhandled_commands);
3782 			else
3783 				ipmi_inc_stat(intf, handled_commands);
3784 		}
3785 	}
3786 
3787 	return rv;
3788 }
3789 
3790 static int handle_lan_get_msg_rsp(struct ipmi_smi *intf,
3791 				  struct ipmi_smi_msg *msg)
3792 {
3793 	struct ipmi_lan_addr  lan_addr;
3794 	struct ipmi_recv_msg  *recv_msg;
3795 
3796 
3797 	/*
3798 	 * This is 13, not 12, because the response must contain a
3799 	 * completion code.
3800 	 */
3801 	if (msg->rsp_size < 13) {
3802 		/* Message not big enough, just ignore it. */
3803 		ipmi_inc_stat(intf, invalid_lan_responses);
3804 		return 0;
3805 	}
3806 
3807 	if (msg->rsp[2] != 0) {
3808 		/* An error getting the response, just ignore it. */
3809 		return 0;
3810 	}
3811 
3812 	lan_addr.addr_type = IPMI_LAN_ADDR_TYPE;
3813 	lan_addr.session_handle = msg->rsp[4];
3814 	lan_addr.remote_SWID = msg->rsp[8];
3815 	lan_addr.local_SWID = msg->rsp[5];
3816 	lan_addr.channel = msg->rsp[3] & 0x0f;
3817 	lan_addr.privilege = msg->rsp[3] >> 4;
3818 	lan_addr.lun = msg->rsp[9] & 3;
3819 
3820 	/*
3821 	 * It's a response from a remote entity.  Look up the sequence
3822 	 * number and handle the response.
3823 	 */
3824 	if (intf_find_seq(intf,
3825 			  msg->rsp[9] >> 2,
3826 			  msg->rsp[3] & 0x0f,
3827 			  msg->rsp[10],
3828 			  (msg->rsp[6] >> 2) & (~1),
3829 			  (struct ipmi_addr *) &lan_addr,
3830 			  &recv_msg)) {
3831 		/*
3832 		 * We were unable to find the sequence number,
3833 		 * so just nuke the message.
3834 		 */
3835 		ipmi_inc_stat(intf, unhandled_lan_responses);
3836 		return 0;
3837 	}
3838 
3839 	memcpy(recv_msg->msg_data, &msg->rsp[11], msg->rsp_size - 11);
3840 	/*
3841 	 * The other fields matched, so no need to set them, except
3842 	 * for netfn, which needs to be the response that was
3843 	 * returned, not the request value.
3844 	 */
3845 	recv_msg->msg.netfn = msg->rsp[6] >> 2;
3846 	recv_msg->msg.data = recv_msg->msg_data;
3847 	recv_msg->msg.data_len = msg->rsp_size - 12;
3848 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
3849 	if (deliver_response(intf, recv_msg))
3850 		ipmi_inc_stat(intf, unhandled_lan_responses);
3851 	else
3852 		ipmi_inc_stat(intf, handled_lan_responses);
3853 
3854 	return 0;
3855 }
3856 
3857 static int handle_lan_get_msg_cmd(struct ipmi_smi *intf,
3858 				  struct ipmi_smi_msg *msg)
3859 {
3860 	struct cmd_rcvr          *rcvr;
3861 	int                      rv = 0;
3862 	unsigned char            netfn;
3863 	unsigned char            cmd;
3864 	unsigned char            chan;
3865 	struct ipmi_user         *user = NULL;
3866 	struct ipmi_lan_addr     *lan_addr;
3867 	struct ipmi_recv_msg     *recv_msg;
3868 
3869 	if (msg->rsp_size < 12) {
3870 		/* Message not big enough, just ignore it. */
3871 		ipmi_inc_stat(intf, invalid_commands);
3872 		return 0;
3873 	}
3874 
3875 	if (msg->rsp[2] != 0) {
3876 		/* An error getting the response, just ignore it. */
3877 		return 0;
3878 	}
3879 
3880 	netfn = msg->rsp[6] >> 2;
3881 	cmd = msg->rsp[10];
3882 	chan = msg->rsp[3] & 0xf;
3883 
3884 	rcu_read_lock();
3885 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
3886 	if (rcvr) {
3887 		user = rcvr->user;
3888 		kref_get(&user->refcount);
3889 	} else
3890 		user = NULL;
3891 	rcu_read_unlock();
3892 
3893 	if (user == NULL) {
3894 		/* We didn't find a user, just give up. */
3895 		ipmi_inc_stat(intf, unhandled_commands);
3896 
3897 		/*
3898 		 * Don't do anything with these messages, just allow
3899 		 * them to be freed.
3900 		 */
3901 		rv = 0;
3902 	} else {
3903 		recv_msg = ipmi_alloc_recv_msg();
3904 		if (!recv_msg) {
3905 			/*
3906 			 * We couldn't allocate memory for the
3907 			 * message, so requeue it for handling later.
3908 			 */
3909 			rv = 1;
3910 			kref_put(&user->refcount, free_user);
3911 		} else {
3912 			/* Extract the source address from the data. */
3913 			lan_addr = (struct ipmi_lan_addr *) &recv_msg->addr;
3914 			lan_addr->addr_type = IPMI_LAN_ADDR_TYPE;
3915 			lan_addr->session_handle = msg->rsp[4];
3916 			lan_addr->remote_SWID = msg->rsp[8];
3917 			lan_addr->local_SWID = msg->rsp[5];
3918 			lan_addr->lun = msg->rsp[9] & 3;
3919 			lan_addr->channel = msg->rsp[3] & 0xf;
3920 			lan_addr->privilege = msg->rsp[3] >> 4;
3921 
3922 			/*
3923 			 * Extract the rest of the message information
3924 			 * from the IPMB header.
3925 			 */
3926 			recv_msg->user = user;
3927 			recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
3928 			recv_msg->msgid = msg->rsp[9] >> 2;
3929 			recv_msg->msg.netfn = msg->rsp[6] >> 2;
3930 			recv_msg->msg.cmd = msg->rsp[10];
3931 			recv_msg->msg.data = recv_msg->msg_data;
3932 
3933 			/*
3934 			 * We chop off 12, not 11 bytes because the checksum
3935 			 * at the end also needs to be removed.
3936 			 */
3937 			recv_msg->msg.data_len = msg->rsp_size - 12;
3938 			memcpy(recv_msg->msg_data, &msg->rsp[11],
3939 			       msg->rsp_size - 12);
3940 			if (deliver_response(intf, recv_msg))
3941 				ipmi_inc_stat(intf, unhandled_commands);
3942 			else
3943 				ipmi_inc_stat(intf, handled_commands);
3944 		}
3945 	}
3946 
3947 	return rv;
3948 }
3949 
3950 /*
3951  * This routine will handle "Get Message" command responses with
3952  * channels that use an OEM Medium. The message format belongs to
3953  * the OEM.  See IPMI 2.0 specification, Chapter 6 and
3954  * Chapter 22, sections 22.6 and 22.24 for more details.
3955  */
3956 static int handle_oem_get_msg_cmd(struct ipmi_smi *intf,
3957 				  struct ipmi_smi_msg *msg)
3958 {
3959 	struct cmd_rcvr       *rcvr;
3960 	int                   rv = 0;
3961 	unsigned char         netfn;
3962 	unsigned char         cmd;
3963 	unsigned char         chan;
3964 	struct ipmi_user *user = NULL;
3965 	struct ipmi_system_interface_addr *smi_addr;
3966 	struct ipmi_recv_msg  *recv_msg;
3967 
3968 	/*
3969 	 * We expect the OEM SW to perform error checking
3970 	 * so we just do some basic sanity checks
3971 	 */
3972 	if (msg->rsp_size < 4) {
3973 		/* Message not big enough, just ignore it. */
3974 		ipmi_inc_stat(intf, invalid_commands);
3975 		return 0;
3976 	}
3977 
3978 	if (msg->rsp[2] != 0) {
3979 		/* An error getting the response, just ignore it. */
3980 		return 0;
3981 	}
3982 
3983 	/*
3984 	 * This is an OEM Message so the OEM needs to know how
3985 	 * handle the message. We do no interpretation.
3986 	 */
3987 	netfn = msg->rsp[0] >> 2;
3988 	cmd = msg->rsp[1];
3989 	chan = msg->rsp[3] & 0xf;
3990 
3991 	rcu_read_lock();
3992 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
3993 	if (rcvr) {
3994 		user = rcvr->user;
3995 		kref_get(&user->refcount);
3996 	} else
3997 		user = NULL;
3998 	rcu_read_unlock();
3999 
4000 	if (user == NULL) {
4001 		/* We didn't find a user, just give up. */
4002 		ipmi_inc_stat(intf, unhandled_commands);
4003 
4004 		/*
4005 		 * Don't do anything with these messages, just allow
4006 		 * them to be freed.
4007 		 */
4008 
4009 		rv = 0;
4010 	} else {
4011 		recv_msg = ipmi_alloc_recv_msg();
4012 		if (!recv_msg) {
4013 			/*
4014 			 * We couldn't allocate memory for the
4015 			 * message, so requeue it for handling
4016 			 * later.
4017 			 */
4018 			rv = 1;
4019 			kref_put(&user->refcount, free_user);
4020 		} else {
4021 			/*
4022 			 * OEM Messages are expected to be delivered via
4023 			 * the system interface to SMS software.  We might
4024 			 * need to visit this again depending on OEM
4025 			 * requirements
4026 			 */
4027 			smi_addr = ((struct ipmi_system_interface_addr *)
4028 				    &recv_msg->addr);
4029 			smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4030 			smi_addr->channel = IPMI_BMC_CHANNEL;
4031 			smi_addr->lun = msg->rsp[0] & 3;
4032 
4033 			recv_msg->user = user;
4034 			recv_msg->user_msg_data = NULL;
4035 			recv_msg->recv_type = IPMI_OEM_RECV_TYPE;
4036 			recv_msg->msg.netfn = msg->rsp[0] >> 2;
4037 			recv_msg->msg.cmd = msg->rsp[1];
4038 			recv_msg->msg.data = recv_msg->msg_data;
4039 
4040 			/*
4041 			 * The message starts at byte 4 which follows the
4042 			 * the Channel Byte in the "GET MESSAGE" command
4043 			 */
4044 			recv_msg->msg.data_len = msg->rsp_size - 4;
4045 			memcpy(recv_msg->msg_data, &msg->rsp[4],
4046 			       msg->rsp_size - 4);
4047 			if (deliver_response(intf, recv_msg))
4048 				ipmi_inc_stat(intf, unhandled_commands);
4049 			else
4050 				ipmi_inc_stat(intf, handled_commands);
4051 		}
4052 	}
4053 
4054 	return rv;
4055 }
4056 
4057 static void copy_event_into_recv_msg(struct ipmi_recv_msg *recv_msg,
4058 				     struct ipmi_smi_msg  *msg)
4059 {
4060 	struct ipmi_system_interface_addr *smi_addr;
4061 
4062 	recv_msg->msgid = 0;
4063 	smi_addr = (struct ipmi_system_interface_addr *) &recv_msg->addr;
4064 	smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4065 	smi_addr->channel = IPMI_BMC_CHANNEL;
4066 	smi_addr->lun = msg->rsp[0] & 3;
4067 	recv_msg->recv_type = IPMI_ASYNC_EVENT_RECV_TYPE;
4068 	recv_msg->msg.netfn = msg->rsp[0] >> 2;
4069 	recv_msg->msg.cmd = msg->rsp[1];
4070 	memcpy(recv_msg->msg_data, &msg->rsp[3], msg->rsp_size - 3);
4071 	recv_msg->msg.data = recv_msg->msg_data;
4072 	recv_msg->msg.data_len = msg->rsp_size - 3;
4073 }
4074 
4075 static int handle_read_event_rsp(struct ipmi_smi *intf,
4076 				 struct ipmi_smi_msg *msg)
4077 {
4078 	struct ipmi_recv_msg *recv_msg, *recv_msg2;
4079 	struct list_head     msgs;
4080 	struct ipmi_user     *user;
4081 	int rv = 0, deliver_count = 0, index;
4082 	unsigned long        flags;
4083 
4084 	if (msg->rsp_size < 19) {
4085 		/* Message is too small to be an IPMB event. */
4086 		ipmi_inc_stat(intf, invalid_events);
4087 		return 0;
4088 	}
4089 
4090 	if (msg->rsp[2] != 0) {
4091 		/* An error getting the event, just ignore it. */
4092 		return 0;
4093 	}
4094 
4095 	INIT_LIST_HEAD(&msgs);
4096 
4097 	spin_lock_irqsave(&intf->events_lock, flags);
4098 
4099 	ipmi_inc_stat(intf, events);
4100 
4101 	/*
4102 	 * Allocate and fill in one message for every user that is
4103 	 * getting events.
4104 	 */
4105 	index = srcu_read_lock(&intf->users_srcu);
4106 	list_for_each_entry_rcu(user, &intf->users, link) {
4107 		if (!user->gets_events)
4108 			continue;
4109 
4110 		recv_msg = ipmi_alloc_recv_msg();
4111 		if (!recv_msg) {
4112 			rcu_read_unlock();
4113 			list_for_each_entry_safe(recv_msg, recv_msg2, &msgs,
4114 						 link) {
4115 				list_del(&recv_msg->link);
4116 				ipmi_free_recv_msg(recv_msg);
4117 			}
4118 			/*
4119 			 * We couldn't allocate memory for the
4120 			 * message, so requeue it for handling
4121 			 * later.
4122 			 */
4123 			rv = 1;
4124 			goto out;
4125 		}
4126 
4127 		deliver_count++;
4128 
4129 		copy_event_into_recv_msg(recv_msg, msg);
4130 		recv_msg->user = user;
4131 		kref_get(&user->refcount);
4132 		list_add_tail(&recv_msg->link, &msgs);
4133 	}
4134 	srcu_read_unlock(&intf->users_srcu, index);
4135 
4136 	if (deliver_count) {
4137 		/* Now deliver all the messages. */
4138 		list_for_each_entry_safe(recv_msg, recv_msg2, &msgs, link) {
4139 			list_del(&recv_msg->link);
4140 			deliver_local_response(intf, recv_msg);
4141 		}
4142 	} else if (intf->waiting_events_count < MAX_EVENTS_IN_QUEUE) {
4143 		/*
4144 		 * No one to receive the message, put it in queue if there's
4145 		 * not already too many things in the queue.
4146 		 */
4147 		recv_msg = ipmi_alloc_recv_msg();
4148 		if (!recv_msg) {
4149 			/*
4150 			 * We couldn't allocate memory for the
4151 			 * message, so requeue it for handling
4152 			 * later.
4153 			 */
4154 			rv = 1;
4155 			goto out;
4156 		}
4157 
4158 		copy_event_into_recv_msg(recv_msg, msg);
4159 		list_add_tail(&recv_msg->link, &intf->waiting_events);
4160 		intf->waiting_events_count++;
4161 	} else if (!intf->event_msg_printed) {
4162 		/*
4163 		 * There's too many things in the queue, discard this
4164 		 * message.
4165 		 */
4166 		dev_warn(intf->si_dev,
4167 			 "Event queue full, discarding incoming events\n");
4168 		intf->event_msg_printed = 1;
4169 	}
4170 
4171  out:
4172 	spin_unlock_irqrestore(&intf->events_lock, flags);
4173 
4174 	return rv;
4175 }
4176 
4177 static int handle_bmc_rsp(struct ipmi_smi *intf,
4178 			  struct ipmi_smi_msg *msg)
4179 {
4180 	struct ipmi_recv_msg *recv_msg;
4181 	struct ipmi_system_interface_addr *smi_addr;
4182 
4183 	recv_msg = (struct ipmi_recv_msg *) msg->user_data;
4184 	if (recv_msg == NULL) {
4185 		dev_warn(intf->si_dev,
4186 			 "IPMI 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");
4187 		return 0;
4188 	}
4189 
4190 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
4191 	recv_msg->msgid = msg->msgid;
4192 	smi_addr = ((struct ipmi_system_interface_addr *)
4193 		    &recv_msg->addr);
4194 	smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4195 	smi_addr->channel = IPMI_BMC_CHANNEL;
4196 	smi_addr->lun = msg->rsp[0] & 3;
4197 	recv_msg->msg.netfn = msg->rsp[0] >> 2;
4198 	recv_msg->msg.cmd = msg->rsp[1];
4199 	memcpy(recv_msg->msg_data, &msg->rsp[2], msg->rsp_size - 2);
4200 	recv_msg->msg.data = recv_msg->msg_data;
4201 	recv_msg->msg.data_len = msg->rsp_size - 2;
4202 	deliver_local_response(intf, recv_msg);
4203 
4204 	return 0;
4205 }
4206 
4207 /*
4208  * Handle a received message.  Return 1 if the message should be requeued,
4209  * 0 if the message should be freed, or -1 if the message should not
4210  * be freed or requeued.
4211  */
4212 static int handle_one_recv_msg(struct ipmi_smi *intf,
4213 			       struct ipmi_smi_msg *msg)
4214 {
4215 	int requeue;
4216 	int chan;
4217 
4218 	pr_debug("Recv: %*ph\n", msg->rsp_size, msg->rsp);
4219 
4220 	if ((msg->data_size >= 2)
4221 	    && (msg->data[0] == (IPMI_NETFN_APP_REQUEST << 2))
4222 	    && (msg->data[1] == IPMI_SEND_MSG_CMD)
4223 	    && (msg->user_data == NULL)) {
4224 
4225 		if (intf->in_shutdown)
4226 			goto free_msg;
4227 
4228 		/*
4229 		 * This is the local response to a command send, start
4230 		 * the timer for these.  The user_data will not be
4231 		 * NULL if this is a response send, and we will let
4232 		 * response sends just go through.
4233 		 */
4234 
4235 		/*
4236 		 * Check for errors, if we get certain errors (ones
4237 		 * that mean basically we can try again later), we
4238 		 * ignore them and start the timer.  Otherwise we
4239 		 * report the error immediately.
4240 		 */
4241 		if ((msg->rsp_size >= 3) && (msg->rsp[2] != 0)
4242 		    && (msg->rsp[2] != IPMI_NODE_BUSY_ERR)
4243 		    && (msg->rsp[2] != IPMI_LOST_ARBITRATION_ERR)
4244 		    && (msg->rsp[2] != IPMI_BUS_ERR)
4245 		    && (msg->rsp[2] != IPMI_NAK_ON_WRITE_ERR)) {
4246 			int ch = msg->rsp[3] & 0xf;
4247 			struct ipmi_channel *chans;
4248 
4249 			/* Got an error sending the message, handle it. */
4250 
4251 			chans = READ_ONCE(intf->channel_list)->c;
4252 			if ((chans[ch].medium == IPMI_CHANNEL_MEDIUM_8023LAN)
4253 			    || (chans[ch].medium == IPMI_CHANNEL_MEDIUM_ASYNC))
4254 				ipmi_inc_stat(intf, sent_lan_command_errs);
4255 			else
4256 				ipmi_inc_stat(intf, sent_ipmb_command_errs);
4257 			intf_err_seq(intf, msg->msgid, msg->rsp[2]);
4258 		} else
4259 			/* The message was sent, start the timer. */
4260 			intf_start_seq_timer(intf, msg->msgid);
4261 free_msg:
4262 		requeue = 0;
4263 		goto out;
4264 
4265 	} else if (msg->rsp_size < 2) {
4266 		/* Message is too small to be correct. */
4267 		dev_warn(intf->si_dev,
4268 			 "BMC returned too small a message for netfn %x cmd %x, got %d bytes\n",
4269 			 (msg->data[0] >> 2) | 1, msg->data[1], msg->rsp_size);
4270 
4271 		/* Generate an error response for the message. */
4272 		msg->rsp[0] = msg->data[0] | (1 << 2);
4273 		msg->rsp[1] = msg->data[1];
4274 		msg->rsp[2] = IPMI_ERR_UNSPECIFIED;
4275 		msg->rsp_size = 3;
4276 	} else if (((msg->rsp[0] >> 2) != ((msg->data[0] >> 2) | 1))
4277 		   || (msg->rsp[1] != msg->data[1])) {
4278 		/*
4279 		 * The NetFN and Command in the response is not even
4280 		 * marginally correct.
4281 		 */
4282 		dev_warn(intf->si_dev,
4283 			 "BMC returned incorrect response, expected netfn %x cmd %x, got netfn %x cmd %x\n",
4284 			 (msg->data[0] >> 2) | 1, msg->data[1],
4285 			 msg->rsp[0] >> 2, msg->rsp[1]);
4286 
4287 		/* Generate an error response for the message. */
4288 		msg->rsp[0] = msg->data[0] | (1 << 2);
4289 		msg->rsp[1] = msg->data[1];
4290 		msg->rsp[2] = IPMI_ERR_UNSPECIFIED;
4291 		msg->rsp_size = 3;
4292 	}
4293 
4294 	if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4295 	    && (msg->rsp[1] == IPMI_SEND_MSG_CMD)
4296 	    && (msg->user_data != NULL)) {
4297 		/*
4298 		 * It's a response to a response we sent.  For this we
4299 		 * deliver a send message response to the user.
4300 		 */
4301 		struct ipmi_recv_msg *recv_msg = msg->user_data;
4302 
4303 		requeue = 0;
4304 		if (msg->rsp_size < 2)
4305 			/* Message is too small to be correct. */
4306 			goto out;
4307 
4308 		chan = msg->data[2] & 0x0f;
4309 		if (chan >= IPMI_MAX_CHANNELS)
4310 			/* Invalid channel number */
4311 			goto out;
4312 
4313 		if (!recv_msg)
4314 			goto out;
4315 
4316 		recv_msg->recv_type = IPMI_RESPONSE_RESPONSE_TYPE;
4317 		recv_msg->msg.data = recv_msg->msg_data;
4318 		recv_msg->msg.data_len = 1;
4319 		recv_msg->msg_data[0] = msg->rsp[2];
4320 		deliver_local_response(intf, recv_msg);
4321 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4322 		   && (msg->rsp[1] == IPMI_GET_MSG_CMD)) {
4323 		struct ipmi_channel   *chans;
4324 
4325 		/* It's from the receive queue. */
4326 		chan = msg->rsp[3] & 0xf;
4327 		if (chan >= IPMI_MAX_CHANNELS) {
4328 			/* Invalid channel number */
4329 			requeue = 0;
4330 			goto out;
4331 		}
4332 
4333 		/*
4334 		 * We need to make sure the channels have been initialized.
4335 		 * The channel_handler routine will set the "curr_channel"
4336 		 * equal to or greater than IPMI_MAX_CHANNELS when all the
4337 		 * channels for this interface have been initialized.
4338 		 */
4339 		if (!intf->channels_ready) {
4340 			requeue = 0; /* Throw the message away */
4341 			goto out;
4342 		}
4343 
4344 		chans = READ_ONCE(intf->channel_list)->c;
4345 
4346 		switch (chans[chan].medium) {
4347 		case IPMI_CHANNEL_MEDIUM_IPMB:
4348 			if (msg->rsp[4] & 0x04) {
4349 				/*
4350 				 * It's a response, so find the
4351 				 * requesting message and send it up.
4352 				 */
4353 				requeue = handle_ipmb_get_msg_rsp(intf, msg);
4354 			} else {
4355 				/*
4356 				 * It's a command to the SMS from some other
4357 				 * entity.  Handle that.
4358 				 */
4359 				requeue = handle_ipmb_get_msg_cmd(intf, msg);
4360 			}
4361 			break;
4362 
4363 		case IPMI_CHANNEL_MEDIUM_8023LAN:
4364 		case IPMI_CHANNEL_MEDIUM_ASYNC:
4365 			if (msg->rsp[6] & 0x04) {
4366 				/*
4367 				 * It's a response, so find the
4368 				 * requesting message and send it up.
4369 				 */
4370 				requeue = handle_lan_get_msg_rsp(intf, msg);
4371 			} else {
4372 				/*
4373 				 * It's a command to the SMS from some other
4374 				 * entity.  Handle that.
4375 				 */
4376 				requeue = handle_lan_get_msg_cmd(intf, msg);
4377 			}
4378 			break;
4379 
4380 		default:
4381 			/* Check for OEM Channels.  Clients had better
4382 			   register for these commands. */
4383 			if ((chans[chan].medium >= IPMI_CHANNEL_MEDIUM_OEM_MIN)
4384 			    && (chans[chan].medium
4385 				<= IPMI_CHANNEL_MEDIUM_OEM_MAX)) {
4386 				requeue = handle_oem_get_msg_cmd(intf, msg);
4387 			} else {
4388 				/*
4389 				 * We don't handle the channel type, so just
4390 				 * free the message.
4391 				 */
4392 				requeue = 0;
4393 			}
4394 		}
4395 
4396 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4397 		   && (msg->rsp[1] == IPMI_READ_EVENT_MSG_BUFFER_CMD)) {
4398 		/* It's an asynchronous event. */
4399 		requeue = handle_read_event_rsp(intf, msg);
4400 	} else {
4401 		/* It's a response from the local BMC. */
4402 		requeue = handle_bmc_rsp(intf, msg);
4403 	}
4404 
4405  out:
4406 	return requeue;
4407 }
4408 
4409 /*
4410  * If there are messages in the queue or pretimeouts, handle them.
4411  */
4412 static void handle_new_recv_msgs(struct ipmi_smi *intf)
4413 {
4414 	struct ipmi_smi_msg  *smi_msg;
4415 	unsigned long        flags = 0;
4416 	int                  rv;
4417 	int                  run_to_completion = intf->run_to_completion;
4418 
4419 	/* See if any waiting messages need to be processed. */
4420 	if (!run_to_completion)
4421 		spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4422 	while (!list_empty(&intf->waiting_rcv_msgs)) {
4423 		smi_msg = list_entry(intf->waiting_rcv_msgs.next,
4424 				     struct ipmi_smi_msg, link);
4425 		list_del(&smi_msg->link);
4426 		if (!run_to_completion)
4427 			spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
4428 					       flags);
4429 		rv = handle_one_recv_msg(intf, smi_msg);
4430 		if (!run_to_completion)
4431 			spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4432 		if (rv > 0) {
4433 			/*
4434 			 * To preserve message order, quit if we
4435 			 * can't handle a message.  Add the message
4436 			 * back at the head, this is safe because this
4437 			 * tasklet is the only thing that pulls the
4438 			 * messages.
4439 			 */
4440 			list_add(&smi_msg->link, &intf->waiting_rcv_msgs);
4441 			break;
4442 		} else {
4443 			if (rv == 0)
4444 				/* Message handled */
4445 				ipmi_free_smi_msg(smi_msg);
4446 			/* If rv < 0, fatal error, del but don't free. */
4447 		}
4448 	}
4449 	if (!run_to_completion)
4450 		spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock, flags);
4451 
4452 	/*
4453 	 * If the pretimout count is non-zero, decrement one from it and
4454 	 * deliver pretimeouts to all the users.
4455 	 */
4456 	if (atomic_add_unless(&intf->watchdog_pretimeouts_to_deliver, -1, 0)) {
4457 		struct ipmi_user *user;
4458 		int index;
4459 
4460 		index = srcu_read_lock(&intf->users_srcu);
4461 		list_for_each_entry_rcu(user, &intf->users, link) {
4462 			if (user->handler->ipmi_watchdog_pretimeout)
4463 				user->handler->ipmi_watchdog_pretimeout(
4464 					user->handler_data);
4465 		}
4466 		srcu_read_unlock(&intf->users_srcu, index);
4467 	}
4468 }
4469 
4470 static void smi_recv_tasklet(unsigned long val)
4471 {
4472 	unsigned long flags = 0; /* keep us warning-free. */
4473 	struct ipmi_smi *intf = (struct ipmi_smi *) val;
4474 	int run_to_completion = intf->run_to_completion;
4475 	struct ipmi_smi_msg *newmsg = NULL;
4476 
4477 	/*
4478 	 * Start the next message if available.
4479 	 *
4480 	 * Do this here, not in the actual receiver, because we may deadlock
4481 	 * because the lower layer is allowed to hold locks while calling
4482 	 * message delivery.
4483 	 */
4484 
4485 	rcu_read_lock();
4486 
4487 	if (!run_to_completion)
4488 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
4489 	if (intf->curr_msg == NULL && !intf->in_shutdown) {
4490 		struct list_head *entry = NULL;
4491 
4492 		/* Pick the high priority queue first. */
4493 		if (!list_empty(&intf->hp_xmit_msgs))
4494 			entry = intf->hp_xmit_msgs.next;
4495 		else if (!list_empty(&intf->xmit_msgs))
4496 			entry = intf->xmit_msgs.next;
4497 
4498 		if (entry) {
4499 			list_del(entry);
4500 			newmsg = list_entry(entry, struct ipmi_smi_msg, link);
4501 			intf->curr_msg = newmsg;
4502 		}
4503 	}
4504 
4505 	if (!run_to_completion)
4506 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
4507 	if (newmsg)
4508 		intf->handlers->sender(intf->send_info, newmsg);
4509 
4510 	rcu_read_unlock();
4511 
4512 	handle_new_recv_msgs(intf);
4513 }
4514 
4515 /* Handle a new message from the lower layer. */
4516 void ipmi_smi_msg_received(struct ipmi_smi *intf,
4517 			   struct ipmi_smi_msg *msg)
4518 {
4519 	unsigned long flags = 0; /* keep us warning-free. */
4520 	int run_to_completion = intf->run_to_completion;
4521 
4522 	/*
4523 	 * To preserve message order, we keep a queue and deliver from
4524 	 * a tasklet.
4525 	 */
4526 	if (!run_to_completion)
4527 		spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4528 	list_add_tail(&msg->link, &intf->waiting_rcv_msgs);
4529 	if (!run_to_completion)
4530 		spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
4531 				       flags);
4532 
4533 	if (!run_to_completion)
4534 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
4535 	/*
4536 	 * We can get an asynchronous event or receive message in addition
4537 	 * to commands we send.
4538 	 */
4539 	if (msg == intf->curr_msg)
4540 		intf->curr_msg = NULL;
4541 	if (!run_to_completion)
4542 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
4543 
4544 	if (run_to_completion)
4545 		smi_recv_tasklet((unsigned long) intf);
4546 	else
4547 		tasklet_schedule(&intf->recv_tasklet);
4548 }
4549 EXPORT_SYMBOL(ipmi_smi_msg_received);
4550 
4551 void ipmi_smi_watchdog_pretimeout(struct ipmi_smi *intf)
4552 {
4553 	if (intf->in_shutdown)
4554 		return;
4555 
4556 	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 1);
4557 	tasklet_schedule(&intf->recv_tasklet);
4558 }
4559 EXPORT_SYMBOL(ipmi_smi_watchdog_pretimeout);
4560 
4561 static struct ipmi_smi_msg *
4562 smi_from_recv_msg(struct ipmi_smi *intf, struct ipmi_recv_msg *recv_msg,
4563 		  unsigned char seq, long seqid)
4564 {
4565 	struct ipmi_smi_msg *smi_msg = ipmi_alloc_smi_msg();
4566 	if (!smi_msg)
4567 		/*
4568 		 * If we can't allocate the message, then just return, we
4569 		 * get 4 retries, so this should be ok.
4570 		 */
4571 		return NULL;
4572 
4573 	memcpy(smi_msg->data, recv_msg->msg.data, recv_msg->msg.data_len);
4574 	smi_msg->data_size = recv_msg->msg.data_len;
4575 	smi_msg->msgid = STORE_SEQ_IN_MSGID(seq, seqid);
4576 
4577 	pr_debug("Resend: %*ph\n", smi_msg->data_size, smi_msg->data);
4578 
4579 	return smi_msg;
4580 }
4581 
4582 static void check_msg_timeout(struct ipmi_smi *intf, struct seq_table *ent,
4583 			      struct list_head *timeouts,
4584 			      unsigned long timeout_period,
4585 			      int slot, unsigned long *flags,
4586 			      bool *need_timer)
4587 {
4588 	struct ipmi_recv_msg *msg;
4589 
4590 	if (intf->in_shutdown)
4591 		return;
4592 
4593 	if (!ent->inuse)
4594 		return;
4595 
4596 	if (timeout_period < ent->timeout) {
4597 		ent->timeout -= timeout_period;
4598 		*need_timer = true;
4599 		return;
4600 	}
4601 
4602 	if (ent->retries_left == 0) {
4603 		/* The message has used all its retries. */
4604 		ent->inuse = 0;
4605 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
4606 		msg = ent->recv_msg;
4607 		list_add_tail(&msg->link, timeouts);
4608 		if (ent->broadcast)
4609 			ipmi_inc_stat(intf, timed_out_ipmb_broadcasts);
4610 		else if (is_lan_addr(&ent->recv_msg->addr))
4611 			ipmi_inc_stat(intf, timed_out_lan_commands);
4612 		else
4613 			ipmi_inc_stat(intf, timed_out_ipmb_commands);
4614 	} else {
4615 		struct ipmi_smi_msg *smi_msg;
4616 		/* More retries, send again. */
4617 
4618 		*need_timer = true;
4619 
4620 		/*
4621 		 * Start with the max timer, set to normal timer after
4622 		 * the message is sent.
4623 		 */
4624 		ent->timeout = MAX_MSG_TIMEOUT;
4625 		ent->retries_left--;
4626 		smi_msg = smi_from_recv_msg(intf, ent->recv_msg, slot,
4627 					    ent->seqid);
4628 		if (!smi_msg) {
4629 			if (is_lan_addr(&ent->recv_msg->addr))
4630 				ipmi_inc_stat(intf,
4631 					      dropped_rexmit_lan_commands);
4632 			else
4633 				ipmi_inc_stat(intf,
4634 					      dropped_rexmit_ipmb_commands);
4635 			return;
4636 		}
4637 
4638 		spin_unlock_irqrestore(&intf->seq_lock, *flags);
4639 
4640 		/*
4641 		 * Send the new message.  We send with a zero
4642 		 * priority.  It timed out, I doubt time is that
4643 		 * critical now, and high priority messages are really
4644 		 * only for messages to the local MC, which don't get
4645 		 * resent.
4646 		 */
4647 		if (intf->handlers) {
4648 			if (is_lan_addr(&ent->recv_msg->addr))
4649 				ipmi_inc_stat(intf,
4650 					      retransmitted_lan_commands);
4651 			else
4652 				ipmi_inc_stat(intf,
4653 					      retransmitted_ipmb_commands);
4654 
4655 			smi_send(intf, intf->handlers, smi_msg, 0);
4656 		} else
4657 			ipmi_free_smi_msg(smi_msg);
4658 
4659 		spin_lock_irqsave(&intf->seq_lock, *flags);
4660 	}
4661 }
4662 
4663 static bool ipmi_timeout_handler(struct ipmi_smi *intf,
4664 				 unsigned long timeout_period)
4665 {
4666 	struct list_head     timeouts;
4667 	struct ipmi_recv_msg *msg, *msg2;
4668 	unsigned long        flags;
4669 	int                  i;
4670 	bool                 need_timer = false;
4671 
4672 	if (!intf->bmc_registered) {
4673 		kref_get(&intf->refcount);
4674 		if (!schedule_work(&intf->bmc_reg_work)) {
4675 			kref_put(&intf->refcount, intf_free);
4676 			need_timer = true;
4677 		}
4678 	}
4679 
4680 	/*
4681 	 * Go through the seq table and find any messages that
4682 	 * have timed out, putting them in the timeouts
4683 	 * list.
4684 	 */
4685 	INIT_LIST_HEAD(&timeouts);
4686 	spin_lock_irqsave(&intf->seq_lock, flags);
4687 	if (intf->ipmb_maintenance_mode_timeout) {
4688 		if (intf->ipmb_maintenance_mode_timeout <= timeout_period)
4689 			intf->ipmb_maintenance_mode_timeout = 0;
4690 		else
4691 			intf->ipmb_maintenance_mode_timeout -= timeout_period;
4692 	}
4693 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++)
4694 		check_msg_timeout(intf, &intf->seq_table[i],
4695 				  &timeouts, timeout_period, i,
4696 				  &flags, &need_timer);
4697 	spin_unlock_irqrestore(&intf->seq_lock, flags);
4698 
4699 	list_for_each_entry_safe(msg, msg2, &timeouts, link)
4700 		deliver_err_response(intf, msg, IPMI_TIMEOUT_COMPLETION_CODE);
4701 
4702 	/*
4703 	 * Maintenance mode handling.  Check the timeout
4704 	 * optimistically before we claim the lock.  It may
4705 	 * mean a timeout gets missed occasionally, but that
4706 	 * only means the timeout gets extended by one period
4707 	 * in that case.  No big deal, and it avoids the lock
4708 	 * most of the time.
4709 	 */
4710 	if (intf->auto_maintenance_timeout > 0) {
4711 		spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
4712 		if (intf->auto_maintenance_timeout > 0) {
4713 			intf->auto_maintenance_timeout
4714 				-= timeout_period;
4715 			if (!intf->maintenance_mode
4716 			    && (intf->auto_maintenance_timeout <= 0)) {
4717 				intf->maintenance_mode_enable = false;
4718 				maintenance_mode_update(intf);
4719 			}
4720 		}
4721 		spin_unlock_irqrestore(&intf->maintenance_mode_lock,
4722 				       flags);
4723 	}
4724 
4725 	tasklet_schedule(&intf->recv_tasklet);
4726 
4727 	return need_timer;
4728 }
4729 
4730 static void ipmi_request_event(struct ipmi_smi *intf)
4731 {
4732 	/* No event requests when in maintenance mode. */
4733 	if (intf->maintenance_mode_enable)
4734 		return;
4735 
4736 	if (!intf->in_shutdown)
4737 		intf->handlers->request_events(intf->send_info);
4738 }
4739 
4740 static struct timer_list ipmi_timer;
4741 
4742 static atomic_t stop_operation;
4743 
4744 static void ipmi_timeout(struct timer_list *unused)
4745 {
4746 	struct ipmi_smi *intf;
4747 	bool need_timer = false;
4748 	int index;
4749 
4750 	if (atomic_read(&stop_operation))
4751 		return;
4752 
4753 	index = srcu_read_lock(&ipmi_interfaces_srcu);
4754 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
4755 		if (atomic_read(&intf->event_waiters)) {
4756 			intf->ticks_to_req_ev--;
4757 			if (intf->ticks_to_req_ev == 0) {
4758 				ipmi_request_event(intf);
4759 				intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
4760 			}
4761 			need_timer = true;
4762 		}
4763 
4764 		need_timer |= ipmi_timeout_handler(intf, IPMI_TIMEOUT_TIME);
4765 	}
4766 	srcu_read_unlock(&ipmi_interfaces_srcu, index);
4767 
4768 	if (need_timer)
4769 		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
4770 }
4771 
4772 static void need_waiter(struct ipmi_smi *intf)
4773 {
4774 	/* Racy, but worst case we start the timer twice. */
4775 	if (!timer_pending(&ipmi_timer))
4776 		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
4777 }
4778 
4779 static atomic_t smi_msg_inuse_count = ATOMIC_INIT(0);
4780 static atomic_t recv_msg_inuse_count = ATOMIC_INIT(0);
4781 
4782 static void free_smi_msg(struct ipmi_smi_msg *msg)
4783 {
4784 	atomic_dec(&smi_msg_inuse_count);
4785 	kfree(msg);
4786 }
4787 
4788 struct ipmi_smi_msg *ipmi_alloc_smi_msg(void)
4789 {
4790 	struct ipmi_smi_msg *rv;
4791 	rv = kmalloc(sizeof(struct ipmi_smi_msg), GFP_ATOMIC);
4792 	if (rv) {
4793 		rv->done = free_smi_msg;
4794 		rv->user_data = NULL;
4795 		atomic_inc(&smi_msg_inuse_count);
4796 	}
4797 	return rv;
4798 }
4799 EXPORT_SYMBOL(ipmi_alloc_smi_msg);
4800 
4801 static void free_recv_msg(struct ipmi_recv_msg *msg)
4802 {
4803 	atomic_dec(&recv_msg_inuse_count);
4804 	kfree(msg);
4805 }
4806 
4807 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void)
4808 {
4809 	struct ipmi_recv_msg *rv;
4810 
4811 	rv = kmalloc(sizeof(struct ipmi_recv_msg), GFP_ATOMIC);
4812 	if (rv) {
4813 		rv->user = NULL;
4814 		rv->done = free_recv_msg;
4815 		atomic_inc(&recv_msg_inuse_count);
4816 	}
4817 	return rv;
4818 }
4819 
4820 void ipmi_free_recv_msg(struct ipmi_recv_msg *msg)
4821 {
4822 	if (msg->user)
4823 		kref_put(&msg->user->refcount, free_user);
4824 	msg->done(msg);
4825 }
4826 EXPORT_SYMBOL(ipmi_free_recv_msg);
4827 
4828 static atomic_t panic_done_count = ATOMIC_INIT(0);
4829 
4830 static void dummy_smi_done_handler(struct ipmi_smi_msg *msg)
4831 {
4832 	atomic_dec(&panic_done_count);
4833 }
4834 
4835 static void dummy_recv_done_handler(struct ipmi_recv_msg *msg)
4836 {
4837 	atomic_dec(&panic_done_count);
4838 }
4839 
4840 /*
4841  * Inside a panic, send a message and wait for a response.
4842  */
4843 static void ipmi_panic_request_and_wait(struct ipmi_smi *intf,
4844 					struct ipmi_addr *addr,
4845 					struct kernel_ipmi_msg *msg)
4846 {
4847 	struct ipmi_smi_msg  smi_msg;
4848 	struct ipmi_recv_msg recv_msg;
4849 	int rv;
4850 
4851 	smi_msg.done = dummy_smi_done_handler;
4852 	recv_msg.done = dummy_recv_done_handler;
4853 	atomic_add(2, &panic_done_count);
4854 	rv = i_ipmi_request(NULL,
4855 			    intf,
4856 			    addr,
4857 			    0,
4858 			    msg,
4859 			    intf,
4860 			    &smi_msg,
4861 			    &recv_msg,
4862 			    0,
4863 			    intf->addrinfo[0].address,
4864 			    intf->addrinfo[0].lun,
4865 			    0, 1); /* Don't retry, and don't wait. */
4866 	if (rv)
4867 		atomic_sub(2, &panic_done_count);
4868 	else if (intf->handlers->flush_messages)
4869 		intf->handlers->flush_messages(intf->send_info);
4870 
4871 	while (atomic_read(&panic_done_count) != 0)
4872 		ipmi_poll(intf);
4873 }
4874 
4875 static void event_receiver_fetcher(struct ipmi_smi *intf,
4876 				   struct ipmi_recv_msg *msg)
4877 {
4878 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
4879 	    && (msg->msg.netfn == IPMI_NETFN_SENSOR_EVENT_RESPONSE)
4880 	    && (msg->msg.cmd == IPMI_GET_EVENT_RECEIVER_CMD)
4881 	    && (msg->msg.data[0] == IPMI_CC_NO_ERROR)) {
4882 		/* A get event receiver command, save it. */
4883 		intf->event_receiver = msg->msg.data[1];
4884 		intf->event_receiver_lun = msg->msg.data[2] & 0x3;
4885 	}
4886 }
4887 
4888 static void device_id_fetcher(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
4889 {
4890 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
4891 	    && (msg->msg.netfn == IPMI_NETFN_APP_RESPONSE)
4892 	    && (msg->msg.cmd == IPMI_GET_DEVICE_ID_CMD)
4893 	    && (msg->msg.data[0] == IPMI_CC_NO_ERROR)) {
4894 		/*
4895 		 * A get device id command, save if we are an event
4896 		 * receiver or generator.
4897 		 */
4898 		intf->local_sel_device = (msg->msg.data[6] >> 2) & 1;
4899 		intf->local_event_generator = (msg->msg.data[6] >> 5) & 1;
4900 	}
4901 }
4902 
4903 static void send_panic_events(struct ipmi_smi *intf, char *str)
4904 {
4905 	struct kernel_ipmi_msg msg;
4906 	unsigned char data[16];
4907 	struct ipmi_system_interface_addr *si;
4908 	struct ipmi_addr addr;
4909 	char *p = str;
4910 	struct ipmi_ipmb_addr *ipmb;
4911 	int j;
4912 
4913 	if (ipmi_send_panic_event == IPMI_SEND_PANIC_EVENT_NONE)
4914 		return;
4915 
4916 	si = (struct ipmi_system_interface_addr *) &addr;
4917 	si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4918 	si->channel = IPMI_BMC_CHANNEL;
4919 	si->lun = 0;
4920 
4921 	/* Fill in an event telling that we have failed. */
4922 	msg.netfn = 0x04; /* Sensor or Event. */
4923 	msg.cmd = 2; /* Platform event command. */
4924 	msg.data = data;
4925 	msg.data_len = 8;
4926 	data[0] = 0x41; /* Kernel generator ID, IPMI table 5-4 */
4927 	data[1] = 0x03; /* This is for IPMI 1.0. */
4928 	data[2] = 0x20; /* OS Critical Stop, IPMI table 36-3 */
4929 	data[4] = 0x6f; /* Sensor specific, IPMI table 36-1 */
4930 	data[5] = 0xa1; /* Runtime stop OEM bytes 2 & 3. */
4931 
4932 	/*
4933 	 * Put a few breadcrumbs in.  Hopefully later we can add more things
4934 	 * to make the panic events more useful.
4935 	 */
4936 	if (str) {
4937 		data[3] = str[0];
4938 		data[6] = str[1];
4939 		data[7] = str[2];
4940 	}
4941 
4942 	/* Send the event announcing the panic. */
4943 	ipmi_panic_request_and_wait(intf, &addr, &msg);
4944 
4945 	/*
4946 	 * On every interface, dump a bunch of OEM event holding the
4947 	 * string.
4948 	 */
4949 	if (ipmi_send_panic_event != IPMI_SEND_PANIC_EVENT_STRING || !str)
4950 		return;
4951 
4952 	/*
4953 	 * intf_num is used as an marker to tell if the
4954 	 * interface is valid.  Thus we need a read barrier to
4955 	 * make sure data fetched before checking intf_num
4956 	 * won't be used.
4957 	 */
4958 	smp_rmb();
4959 
4960 	/*
4961 	 * First job here is to figure out where to send the
4962 	 * OEM events.  There's no way in IPMI to send OEM
4963 	 * events using an event send command, so we have to
4964 	 * find the SEL to put them in and stick them in
4965 	 * there.
4966 	 */
4967 
4968 	/* Get capabilities from the get device id. */
4969 	intf->local_sel_device = 0;
4970 	intf->local_event_generator = 0;
4971 	intf->event_receiver = 0;
4972 
4973 	/* Request the device info from the local MC. */
4974 	msg.netfn = IPMI_NETFN_APP_REQUEST;
4975 	msg.cmd = IPMI_GET_DEVICE_ID_CMD;
4976 	msg.data = NULL;
4977 	msg.data_len = 0;
4978 	intf->null_user_handler = device_id_fetcher;
4979 	ipmi_panic_request_and_wait(intf, &addr, &msg);
4980 
4981 	if (intf->local_event_generator) {
4982 		/* Request the event receiver from the local MC. */
4983 		msg.netfn = IPMI_NETFN_SENSOR_EVENT_REQUEST;
4984 		msg.cmd = IPMI_GET_EVENT_RECEIVER_CMD;
4985 		msg.data = NULL;
4986 		msg.data_len = 0;
4987 		intf->null_user_handler = event_receiver_fetcher;
4988 		ipmi_panic_request_and_wait(intf, &addr, &msg);
4989 	}
4990 	intf->null_user_handler = NULL;
4991 
4992 	/*
4993 	 * Validate the event receiver.  The low bit must not
4994 	 * be 1 (it must be a valid IPMB address), it cannot
4995 	 * be zero, and it must not be my address.
4996 	 */
4997 	if (((intf->event_receiver & 1) == 0)
4998 	    && (intf->event_receiver != 0)
4999 	    && (intf->event_receiver != intf->addrinfo[0].address)) {
5000 		/*
5001 		 * The event receiver is valid, send an IPMB
5002 		 * message.
5003 		 */
5004 		ipmb = (struct ipmi_ipmb_addr *) &addr;
5005 		ipmb->addr_type = IPMI_IPMB_ADDR_TYPE;
5006 		ipmb->channel = 0; /* FIXME - is this right? */
5007 		ipmb->lun = intf->event_receiver_lun;
5008 		ipmb->slave_addr = intf->event_receiver;
5009 	} else if (intf->local_sel_device) {
5010 		/*
5011 		 * The event receiver was not valid (or was
5012 		 * me), but I am an SEL device, just dump it
5013 		 * in my SEL.
5014 		 */
5015 		si = (struct ipmi_system_interface_addr *) &addr;
5016 		si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
5017 		si->channel = IPMI_BMC_CHANNEL;
5018 		si->lun = 0;
5019 	} else
5020 		return; /* No where to send the event. */
5021 
5022 	msg.netfn = IPMI_NETFN_STORAGE_REQUEST; /* Storage. */
5023 	msg.cmd = IPMI_ADD_SEL_ENTRY_CMD;
5024 	msg.data = data;
5025 	msg.data_len = 16;
5026 
5027 	j = 0;
5028 	while (*p) {
5029 		int size = strlen(p);
5030 
5031 		if (size > 11)
5032 			size = 11;
5033 		data[0] = 0;
5034 		data[1] = 0;
5035 		data[2] = 0xf0; /* OEM event without timestamp. */
5036 		data[3] = intf->addrinfo[0].address;
5037 		data[4] = j++; /* sequence # */
5038 		/*
5039 		 * Always give 11 bytes, so strncpy will fill
5040 		 * it with zeroes for me.
5041 		 */
5042 		strncpy(data+5, p, 11);
5043 		p += size;
5044 
5045 		ipmi_panic_request_and_wait(intf, &addr, &msg);
5046 	}
5047 }
5048 
5049 static int has_panicked;
5050 
5051 static int panic_event(struct notifier_block *this,
5052 		       unsigned long         event,
5053 		       void                  *ptr)
5054 {
5055 	struct ipmi_smi *intf;
5056 	struct ipmi_user *user;
5057 
5058 	if (has_panicked)
5059 		return NOTIFY_DONE;
5060 	has_panicked = 1;
5061 
5062 	/* For every registered interface, set it to run to completion. */
5063 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
5064 		if (!intf->handlers || intf->intf_num == -1)
5065 			/* Interface is not ready. */
5066 			continue;
5067 
5068 		if (!intf->handlers->poll)
5069 			continue;
5070 
5071 		/*
5072 		 * If we were interrupted while locking xmit_msgs_lock or
5073 		 * waiting_rcv_msgs_lock, the corresponding list may be
5074 		 * corrupted.  In this case, drop items on the list for
5075 		 * the safety.
5076 		 */
5077 		if (!spin_trylock(&intf->xmit_msgs_lock)) {
5078 			INIT_LIST_HEAD(&intf->xmit_msgs);
5079 			INIT_LIST_HEAD(&intf->hp_xmit_msgs);
5080 		} else
5081 			spin_unlock(&intf->xmit_msgs_lock);
5082 
5083 		if (!spin_trylock(&intf->waiting_rcv_msgs_lock))
5084 			INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
5085 		else
5086 			spin_unlock(&intf->waiting_rcv_msgs_lock);
5087 
5088 		intf->run_to_completion = 1;
5089 		if (intf->handlers->set_run_to_completion)
5090 			intf->handlers->set_run_to_completion(intf->send_info,
5091 							      1);
5092 
5093 		list_for_each_entry_rcu(user, &intf->users, link) {
5094 			if (user->handler->ipmi_panic_handler)
5095 				user->handler->ipmi_panic_handler(
5096 					user->handler_data);
5097 		}
5098 
5099 		send_panic_events(intf, ptr);
5100 	}
5101 
5102 	return NOTIFY_DONE;
5103 }
5104 
5105 /* Must be called with ipmi_interfaces_mutex held. */
5106 static int ipmi_register_driver(void)
5107 {
5108 	int rv;
5109 
5110 	if (drvregistered)
5111 		return 0;
5112 
5113 	rv = driver_register(&ipmidriver.driver);
5114 	if (rv)
5115 		pr_err("Could not register IPMI driver\n");
5116 	else
5117 		drvregistered = true;
5118 	return rv;
5119 }
5120 
5121 static struct notifier_block panic_block = {
5122 	.notifier_call	= panic_event,
5123 	.next		= NULL,
5124 	.priority	= 200	/* priority: INT_MAX >= x >= 0 */
5125 };
5126 
5127 static int ipmi_init_msghandler(void)
5128 {
5129 	int rv;
5130 
5131 	mutex_lock(&ipmi_interfaces_mutex);
5132 	rv = ipmi_register_driver();
5133 	if (rv)
5134 		goto out;
5135 	if (initialized)
5136 		goto out;
5137 
5138 	init_srcu_struct(&ipmi_interfaces_srcu);
5139 
5140 	timer_setup(&ipmi_timer, ipmi_timeout, 0);
5141 	mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
5142 
5143 	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
5144 
5145 	initialized = true;
5146 
5147 out:
5148 	mutex_unlock(&ipmi_interfaces_mutex);
5149 	return rv;
5150 }
5151 
5152 static int __init ipmi_init_msghandler_mod(void)
5153 {
5154 	int rv;
5155 
5156 	pr_info("version " IPMI_DRIVER_VERSION "\n");
5157 
5158 	mutex_lock(&ipmi_interfaces_mutex);
5159 	rv = ipmi_register_driver();
5160 	mutex_unlock(&ipmi_interfaces_mutex);
5161 
5162 	return rv;
5163 }
5164 
5165 static void __exit cleanup_ipmi(void)
5166 {
5167 	int count;
5168 
5169 	if (initialized) {
5170 		atomic_notifier_chain_unregister(&panic_notifier_list,
5171 						 &panic_block);
5172 
5173 		/*
5174 		 * This can't be called if any interfaces exist, so no worry
5175 		 * about shutting down the interfaces.
5176 		 */
5177 
5178 		/*
5179 		 * Tell the timer to stop, then wait for it to stop.  This
5180 		 * avoids problems with race conditions removing the timer
5181 		 * here.
5182 		 */
5183 		atomic_set(&stop_operation, 1);
5184 		del_timer_sync(&ipmi_timer);
5185 
5186 		initialized = false;
5187 
5188 		/* Check for buffer leaks. */
5189 		count = atomic_read(&smi_msg_inuse_count);
5190 		if (count != 0)
5191 			pr_warn("SMI message count %d at exit\n", count);
5192 		count = atomic_read(&recv_msg_inuse_count);
5193 		if (count != 0)
5194 			pr_warn("recv message count %d at exit\n", count);
5195 
5196 		cleanup_srcu_struct(&ipmi_interfaces_srcu);
5197 	}
5198 	if (drvregistered)
5199 		driver_unregister(&ipmidriver.driver);
5200 }
5201 module_exit(cleanup_ipmi);
5202 
5203 module_init(ipmi_init_msghandler_mod);
5204 MODULE_LICENSE("GPL");
5205 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
5206 MODULE_DESCRIPTION("Incoming and outgoing message routing for an IPMI"
5207 		   " interface.");
5208 MODULE_VERSION(IPMI_DRIVER_VERSION);
5209 MODULE_SOFTDEP("post: ipmi_devintf");
5210