xref: /openbmc/linux/drivers/char/ipmi/ipmi_msghandler.c (revision b240b419db5d624ce7a5a397d6f62a1a686009ec)
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 #include <linux/module.h>
15 #include <linux/errno.h>
16 #include <linux/poll.h>
17 #include <linux/sched.h>
18 #include <linux/seq_file.h>
19 #include <linux/spinlock.h>
20 #include <linux/mutex.h>
21 #include <linux/slab.h>
22 #include <linux/ipmi.h>
23 #include <linux/ipmi_smi.h>
24 #include <linux/notifier.h>
25 #include <linux/init.h>
26 #include <linux/proc_fs.h>
27 #include <linux/rcupdate.h>
28 #include <linux/interrupt.h>
29 #include <linux/moduleparam.h>
30 #include <linux/workqueue.h>
31 #include <linux/uuid.h>
32 
33 #define PFX "IPMI message handler: "
34 
35 #define IPMI_DRIVER_VERSION "39.2"
36 
37 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void);
38 static int ipmi_init_msghandler(void);
39 static void smi_recv_tasklet(unsigned long);
40 static void handle_new_recv_msgs(ipmi_smi_t intf);
41 static void need_waiter(ipmi_smi_t intf);
42 static int handle_one_recv_msg(ipmi_smi_t          intf,
43 			       struct ipmi_smi_msg *msg);
44 
45 static int initialized;
46 
47 enum ipmi_panic_event_op {
48 	IPMI_SEND_PANIC_EVENT_NONE,
49 	IPMI_SEND_PANIC_EVENT,
50 	IPMI_SEND_PANIC_EVENT_STRING
51 };
52 #ifdef CONFIG_IPMI_PANIC_STRING
53 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT_STRING
54 #elif defined(CONFIG_IPMI_PANIC_EVENT)
55 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT
56 #else
57 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT_NONE
58 #endif
59 static enum ipmi_panic_event_op ipmi_send_panic_event = IPMI_PANIC_DEFAULT;
60 
61 static int panic_op_write_handler(const char *val,
62 				  const struct kernel_param *kp)
63 {
64 	char valcp[16];
65 	char *s;
66 
67 	strncpy(valcp, val, 15);
68 	valcp[15] = '\0';
69 
70 	s = strstrip(valcp);
71 
72 	if (strcmp(s, "none") == 0)
73 		ipmi_send_panic_event = IPMI_SEND_PANIC_EVENT_NONE;
74 	else if (strcmp(s, "event") == 0)
75 		ipmi_send_panic_event = IPMI_SEND_PANIC_EVENT;
76 	else if (strcmp(s, "string") == 0)
77 		ipmi_send_panic_event = IPMI_SEND_PANIC_EVENT_STRING;
78 	else
79 		return -EINVAL;
80 
81 	return 0;
82 }
83 
84 static int panic_op_read_handler(char *buffer, const struct kernel_param *kp)
85 {
86 	switch (ipmi_send_panic_event) {
87 	case IPMI_SEND_PANIC_EVENT_NONE:
88 		strcpy(buffer, "none");
89 		break;
90 
91 	case IPMI_SEND_PANIC_EVENT:
92 		strcpy(buffer, "event");
93 		break;
94 
95 	case IPMI_SEND_PANIC_EVENT_STRING:
96 		strcpy(buffer, "string");
97 		break;
98 
99 	default:
100 		strcpy(buffer, "???");
101 		break;
102 	}
103 
104 	return strlen(buffer);
105 }
106 
107 static const struct kernel_param_ops panic_op_ops = {
108 	.set = panic_op_write_handler,
109 	.get = panic_op_read_handler
110 };
111 module_param_cb(panic_op, &panic_op_ops, NULL, 0600);
112 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.");
113 
114 
115 #ifdef CONFIG_IPMI_PROC_INTERFACE
116 static struct proc_dir_entry *proc_ipmi_root;
117 #endif /* CONFIG_IPMI_PROC_INTERFACE */
118 
119 /* Remain in auto-maintenance mode for this amount of time (in ms). */
120 #define IPMI_MAINTENANCE_MODE_TIMEOUT 30000
121 
122 #define MAX_EVENTS_IN_QUEUE	25
123 
124 /*
125  * Don't let a message sit in a queue forever, always time it with at lest
126  * the max message timer.  This is in milliseconds.
127  */
128 #define MAX_MSG_TIMEOUT		60000
129 
130 /* Call every ~1000 ms. */
131 #define IPMI_TIMEOUT_TIME	1000
132 
133 /* How many jiffies does it take to get to the timeout time. */
134 #define IPMI_TIMEOUT_JIFFIES	((IPMI_TIMEOUT_TIME * HZ) / 1000)
135 
136 /*
137  * Request events from the queue every second (this is the number of
138  * IPMI_TIMEOUT_TIMES between event requests).  Hopefully, in the
139  * future, IPMI will add a way to know immediately if an event is in
140  * the queue and this silliness can go away.
141  */
142 #define IPMI_REQUEST_EV_TIME	(1000 / (IPMI_TIMEOUT_TIME))
143 
144 /* How long should we cache dynamic device IDs? */
145 #define IPMI_DYN_DEV_ID_EXPIRY	(10 * HZ)
146 
147 /*
148  * The main "user" data structure.
149  */
150 struct ipmi_user {
151 	struct list_head link;
152 
153 	/* Set to false when the user is destroyed. */
154 	bool valid;
155 
156 	struct kref refcount;
157 
158 	/* The upper layer that handles receive messages. */
159 	const struct ipmi_user_hndl *handler;
160 	void             *handler_data;
161 
162 	/* The interface this user is bound to. */
163 	ipmi_smi_t intf;
164 
165 	/* Does this interface receive IPMI events? */
166 	bool gets_events;
167 };
168 
169 struct cmd_rcvr {
170 	struct list_head link;
171 
172 	ipmi_user_t   user;
173 	unsigned char netfn;
174 	unsigned char cmd;
175 	unsigned int  chans;
176 
177 	/*
178 	 * This is used to form a linked lised during mass deletion.
179 	 * Since this is in an RCU list, we cannot use the link above
180 	 * or change any data until the RCU period completes.  So we
181 	 * use this next variable during mass deletion so we can have
182 	 * a list and don't have to wait and restart the search on
183 	 * every individual deletion of a command.
184 	 */
185 	struct cmd_rcvr *next;
186 };
187 
188 struct seq_table {
189 	unsigned int         inuse : 1;
190 	unsigned int         broadcast : 1;
191 
192 	unsigned long        timeout;
193 	unsigned long        orig_timeout;
194 	unsigned int         retries_left;
195 
196 	/*
197 	 * To verify on an incoming send message response that this is
198 	 * the message that the response is for, we keep a sequence id
199 	 * and increment it every time we send a message.
200 	 */
201 	long                 seqid;
202 
203 	/*
204 	 * This is held so we can properly respond to the message on a
205 	 * timeout, and it is used to hold the temporary data for
206 	 * retransmission, too.
207 	 */
208 	struct ipmi_recv_msg *recv_msg;
209 };
210 
211 /*
212  * Store the information in a msgid (long) to allow us to find a
213  * sequence table entry from the msgid.
214  */
215 #define STORE_SEQ_IN_MSGID(seq, seqid) \
216 	((((seq) & 0x3f) << 26) | ((seqid) & 0x3ffffff))
217 
218 #define GET_SEQ_FROM_MSGID(msgid, seq, seqid) \
219 	do {								\
220 		seq = (((msgid) >> 26) & 0x3f);				\
221 		seqid = ((msgid) & 0x3ffffff);				\
222 	} while (0)
223 
224 #define NEXT_SEQID(seqid) (((seqid) + 1) & 0x3ffffff)
225 
226 #define IPMI_MAX_CHANNELS       16
227 struct ipmi_channel {
228 	unsigned char medium;
229 	unsigned char protocol;
230 };
231 
232 struct ipmi_channel_set {
233 	struct ipmi_channel c[IPMI_MAX_CHANNELS];
234 };
235 
236 struct ipmi_my_addrinfo {
237 	/*
238 	 * My slave address.  This is initialized to IPMI_BMC_SLAVE_ADDR,
239 	 * but may be changed by the user.
240 	 */
241 	unsigned char address;
242 
243 	/*
244 	 * My LUN.  This should generally stay the SMS LUN, but just in
245 	 * case...
246 	 */
247 	unsigned char lun;
248 };
249 
250 #ifdef CONFIG_IPMI_PROC_INTERFACE
251 struct ipmi_proc_entry {
252 	char                   *name;
253 	struct ipmi_proc_entry *next;
254 };
255 #endif
256 
257 /*
258  * Note that the product id, manufacturer id, guid, and device id are
259  * immutable in this structure, so dyn_mutex is not required for
260  * accessing those.  If those change on a BMC, a new BMC is allocated.
261  */
262 struct bmc_device {
263 	struct platform_device pdev;
264 	struct list_head       intfs; /* Interfaces on this BMC. */
265 	struct ipmi_device_id  id;
266 	struct ipmi_device_id  fetch_id;
267 	int                    dyn_id_set;
268 	unsigned long          dyn_id_expiry;
269 	struct mutex           dyn_mutex; /* Protects id, intfs, & dyn* */
270 	guid_t                 guid;
271 	guid_t                 fetch_guid;
272 	int                    dyn_guid_set;
273 	struct kref	       usecount;
274 	struct work_struct     remove_work;
275 };
276 #define to_bmc_device(x) container_of((x), struct bmc_device, pdev.dev)
277 
278 static int bmc_get_device_id(ipmi_smi_t intf, struct bmc_device *bmc,
279 			     struct ipmi_device_id *id,
280 			     bool *guid_set, guid_t *guid);
281 
282 /*
283  * Various statistics for IPMI, these index stats[] in the ipmi_smi
284  * structure.
285  */
286 enum ipmi_stat_indexes {
287 	/* Commands we got from the user that were invalid. */
288 	IPMI_STAT_sent_invalid_commands = 0,
289 
290 	/* Commands we sent to the MC. */
291 	IPMI_STAT_sent_local_commands,
292 
293 	/* Responses from the MC that were delivered to a user. */
294 	IPMI_STAT_handled_local_responses,
295 
296 	/* Responses from the MC that were not delivered to a user. */
297 	IPMI_STAT_unhandled_local_responses,
298 
299 	/* Commands we sent out to the IPMB bus. */
300 	IPMI_STAT_sent_ipmb_commands,
301 
302 	/* Commands sent on the IPMB that had errors on the SEND CMD */
303 	IPMI_STAT_sent_ipmb_command_errs,
304 
305 	/* Each retransmit increments this count. */
306 	IPMI_STAT_retransmitted_ipmb_commands,
307 
308 	/*
309 	 * When a message times out (runs out of retransmits) this is
310 	 * incremented.
311 	 */
312 	IPMI_STAT_timed_out_ipmb_commands,
313 
314 	/*
315 	 * This is like above, but for broadcasts.  Broadcasts are
316 	 * *not* included in the above count (they are expected to
317 	 * time out).
318 	 */
319 	IPMI_STAT_timed_out_ipmb_broadcasts,
320 
321 	/* Responses I have sent to the IPMB bus. */
322 	IPMI_STAT_sent_ipmb_responses,
323 
324 	/* The response was delivered to the user. */
325 	IPMI_STAT_handled_ipmb_responses,
326 
327 	/* The response had invalid data in it. */
328 	IPMI_STAT_invalid_ipmb_responses,
329 
330 	/* The response didn't have anyone waiting for it. */
331 	IPMI_STAT_unhandled_ipmb_responses,
332 
333 	/* Commands we sent out to the IPMB bus. */
334 	IPMI_STAT_sent_lan_commands,
335 
336 	/* Commands sent on the IPMB that had errors on the SEND CMD */
337 	IPMI_STAT_sent_lan_command_errs,
338 
339 	/* Each retransmit increments this count. */
340 	IPMI_STAT_retransmitted_lan_commands,
341 
342 	/*
343 	 * When a message times out (runs out of retransmits) this is
344 	 * incremented.
345 	 */
346 	IPMI_STAT_timed_out_lan_commands,
347 
348 	/* Responses I have sent to the IPMB bus. */
349 	IPMI_STAT_sent_lan_responses,
350 
351 	/* The response was delivered to the user. */
352 	IPMI_STAT_handled_lan_responses,
353 
354 	/* The response had invalid data in it. */
355 	IPMI_STAT_invalid_lan_responses,
356 
357 	/* The response didn't have anyone waiting for it. */
358 	IPMI_STAT_unhandled_lan_responses,
359 
360 	/* The command was delivered to the user. */
361 	IPMI_STAT_handled_commands,
362 
363 	/* The command had invalid data in it. */
364 	IPMI_STAT_invalid_commands,
365 
366 	/* The command didn't have anyone waiting for it. */
367 	IPMI_STAT_unhandled_commands,
368 
369 	/* Invalid data in an event. */
370 	IPMI_STAT_invalid_events,
371 
372 	/* Events that were received with the proper format. */
373 	IPMI_STAT_events,
374 
375 	/* Retransmissions on IPMB that failed. */
376 	IPMI_STAT_dropped_rexmit_ipmb_commands,
377 
378 	/* Retransmissions on LAN that failed. */
379 	IPMI_STAT_dropped_rexmit_lan_commands,
380 
381 	/* This *must* remain last, add new values above this. */
382 	IPMI_NUM_STATS
383 };
384 
385 
386 #define IPMI_IPMB_NUM_SEQ	64
387 struct ipmi_smi {
388 	/* What interface number are we? */
389 	int intf_num;
390 
391 	struct kref refcount;
392 
393 	/* Set when the interface is being unregistered. */
394 	bool in_shutdown;
395 
396 	/* Used for a list of interfaces. */
397 	struct list_head link;
398 
399 	/*
400 	 * The list of upper layers that are using me.  seq_lock
401 	 * protects this.
402 	 */
403 	struct list_head users;
404 
405 	/* Used for wake ups at startup. */
406 	wait_queue_head_t waitq;
407 
408 	/*
409 	 * Prevents the interface from being unregistered when the
410 	 * interface is used by being looked up through the BMC
411 	 * structure.
412 	 */
413 	struct mutex bmc_reg_mutex;
414 
415 	struct bmc_device tmp_bmc;
416 	struct bmc_device *bmc;
417 	bool bmc_registered;
418 	struct list_head bmc_link;
419 	char *my_dev_name;
420 	bool in_bmc_register;  /* Handle recursive situations.  Yuck. */
421 	struct work_struct bmc_reg_work;
422 
423 	/*
424 	 * This is the lower-layer's sender routine.  Note that you
425 	 * must either be holding the ipmi_interfaces_mutex or be in
426 	 * an umpreemptible region to use this.  You must fetch the
427 	 * value into a local variable and make sure it is not NULL.
428 	 */
429 	const struct ipmi_smi_handlers *handlers;
430 	void                     *send_info;
431 
432 #ifdef CONFIG_IPMI_PROC_INTERFACE
433 	/* A list of proc entries for this interface. */
434 	struct mutex           proc_entry_lock;
435 	struct ipmi_proc_entry *proc_entries;
436 
437 	struct proc_dir_entry *proc_dir;
438 	char                  proc_dir_name[10];
439 #endif
440 
441 	/* Driver-model device for the system interface. */
442 	struct device          *si_dev;
443 
444 	/*
445 	 * A table of sequence numbers for this interface.  We use the
446 	 * sequence numbers for IPMB messages that go out of the
447 	 * interface to match them up with their responses.  A routine
448 	 * is called periodically to time the items in this list.
449 	 */
450 	spinlock_t       seq_lock;
451 	struct seq_table seq_table[IPMI_IPMB_NUM_SEQ];
452 	int curr_seq;
453 
454 	/*
455 	 * Messages queued for delivery.  If delivery fails (out of memory
456 	 * for instance), They will stay in here to be processed later in a
457 	 * periodic timer interrupt.  The tasklet is for handling received
458 	 * messages directly from the handler.
459 	 */
460 	spinlock_t       waiting_rcv_msgs_lock;
461 	struct list_head waiting_rcv_msgs;
462 	atomic_t	 watchdog_pretimeouts_to_deliver;
463 	struct tasklet_struct recv_tasklet;
464 
465 	spinlock_t             xmit_msgs_lock;
466 	struct list_head       xmit_msgs;
467 	struct ipmi_smi_msg    *curr_msg;
468 	struct list_head       hp_xmit_msgs;
469 
470 	/*
471 	 * The list of command receivers that are registered for commands
472 	 * on this interface.
473 	 */
474 	struct mutex     cmd_rcvrs_mutex;
475 	struct list_head cmd_rcvrs;
476 
477 	/*
478 	 * Events that were queues because no one was there to receive
479 	 * them.
480 	 */
481 	spinlock_t       events_lock; /* For dealing with event stuff. */
482 	struct list_head waiting_events;
483 	unsigned int     waiting_events_count; /* How many events in queue? */
484 	char             delivering_events;
485 	char             event_msg_printed;
486 	atomic_t         event_waiters;
487 	unsigned int     ticks_to_req_ev;
488 	int              last_needs_timer;
489 
490 	/*
491 	 * The event receiver for my BMC, only really used at panic
492 	 * shutdown as a place to store this.
493 	 */
494 	unsigned char event_receiver;
495 	unsigned char event_receiver_lun;
496 	unsigned char local_sel_device;
497 	unsigned char local_event_generator;
498 
499 	/* For handling of maintenance mode. */
500 	int maintenance_mode;
501 	bool maintenance_mode_enable;
502 	int auto_maintenance_timeout;
503 	spinlock_t maintenance_mode_lock; /* Used in a timer... */
504 
505 	/*
506 	 * A cheap hack, if this is non-null and a message to an
507 	 * interface comes in with a NULL user, call this routine with
508 	 * it.  Note that the message will still be freed by the
509 	 * caller.  This only works on the system interface.
510 	 *
511 	 * Protected by bmc_reg_mutex.
512 	 */
513 	void (*null_user_handler)(ipmi_smi_t intf, struct ipmi_recv_msg *msg);
514 
515 	/*
516 	 * When we are scanning the channels for an SMI, this will
517 	 * tell which channel we are scanning.
518 	 */
519 	int curr_channel;
520 
521 	/* Channel information */
522 	struct ipmi_channel_set *channel_list;
523 	unsigned int curr_working_cset; /* First index into the following. */
524 	struct ipmi_channel_set wchannels[2];
525 	struct ipmi_my_addrinfo addrinfo[IPMI_MAX_CHANNELS];
526 	bool channels_ready;
527 
528 	atomic_t stats[IPMI_NUM_STATS];
529 
530 	/*
531 	 * run_to_completion duplicate of smb_info, smi_info
532 	 * and ipmi_serial_info structures. Used to decrease numbers of
533 	 * parameters passed by "low" level IPMI code.
534 	 */
535 	int run_to_completion;
536 };
537 #define to_si_intf_from_dev(device) container_of(device, struct ipmi_smi, dev)
538 
539 static void __get_guid(ipmi_smi_t intf);
540 static void __ipmi_bmc_unregister(ipmi_smi_t intf);
541 static int __ipmi_bmc_register(ipmi_smi_t intf,
542 			       struct ipmi_device_id *id,
543 			       bool guid_set, guid_t *guid, int intf_num);
544 static int __scan_channels(ipmi_smi_t intf, struct ipmi_device_id *id);
545 
546 
547 /**
548  * The driver model view of the IPMI messaging driver.
549  */
550 static struct platform_driver ipmidriver = {
551 	.driver = {
552 		.name = "ipmi",
553 		.bus = &platform_bus_type
554 	}
555 };
556 /*
557  * This mutex keeps us from adding the same BMC twice.
558  */
559 static DEFINE_MUTEX(ipmidriver_mutex);
560 
561 static LIST_HEAD(ipmi_interfaces);
562 static DEFINE_MUTEX(ipmi_interfaces_mutex);
563 
564 /*
565  * List of watchers that want to know when smi's are added and deleted.
566  */
567 static LIST_HEAD(smi_watchers);
568 static DEFINE_MUTEX(smi_watchers_mutex);
569 
570 #define ipmi_inc_stat(intf, stat) \
571 	atomic_inc(&(intf)->stats[IPMI_STAT_ ## stat])
572 #define ipmi_get_stat(intf, stat) \
573 	((unsigned int) atomic_read(&(intf)->stats[IPMI_STAT_ ## stat]))
574 
575 static const char * const addr_src_to_str[] = {
576 	"invalid", "hotmod", "hardcoded", "SPMI", "ACPI", "SMBIOS", "PCI",
577 	"device-tree", "platform"
578 };
579 
580 const char *ipmi_addr_src_to_str(enum ipmi_addr_src src)
581 {
582 	if (src >= SI_LAST)
583 		src = 0; /* Invalid */
584 	return addr_src_to_str[src];
585 }
586 EXPORT_SYMBOL(ipmi_addr_src_to_str);
587 
588 static int is_lan_addr(struct ipmi_addr *addr)
589 {
590 	return addr->addr_type == IPMI_LAN_ADDR_TYPE;
591 }
592 
593 static int is_ipmb_addr(struct ipmi_addr *addr)
594 {
595 	return addr->addr_type == IPMI_IPMB_ADDR_TYPE;
596 }
597 
598 static int is_ipmb_bcast_addr(struct ipmi_addr *addr)
599 {
600 	return addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE;
601 }
602 
603 static void free_recv_msg_list(struct list_head *q)
604 {
605 	struct ipmi_recv_msg *msg, *msg2;
606 
607 	list_for_each_entry_safe(msg, msg2, q, link) {
608 		list_del(&msg->link);
609 		ipmi_free_recv_msg(msg);
610 	}
611 }
612 
613 static void free_smi_msg_list(struct list_head *q)
614 {
615 	struct ipmi_smi_msg *msg, *msg2;
616 
617 	list_for_each_entry_safe(msg, msg2, q, link) {
618 		list_del(&msg->link);
619 		ipmi_free_smi_msg(msg);
620 	}
621 }
622 
623 static void clean_up_interface_data(ipmi_smi_t intf)
624 {
625 	int              i;
626 	struct cmd_rcvr  *rcvr, *rcvr2;
627 	struct list_head list;
628 
629 	tasklet_kill(&intf->recv_tasklet);
630 
631 	free_smi_msg_list(&intf->waiting_rcv_msgs);
632 	free_recv_msg_list(&intf->waiting_events);
633 
634 	/*
635 	 * Wholesale remove all the entries from the list in the
636 	 * interface and wait for RCU to know that none are in use.
637 	 */
638 	mutex_lock(&intf->cmd_rcvrs_mutex);
639 	INIT_LIST_HEAD(&list);
640 	list_splice_init_rcu(&intf->cmd_rcvrs, &list, synchronize_rcu);
641 	mutex_unlock(&intf->cmd_rcvrs_mutex);
642 
643 	list_for_each_entry_safe(rcvr, rcvr2, &list, link)
644 		kfree(rcvr);
645 
646 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
647 		if ((intf->seq_table[i].inuse)
648 					&& (intf->seq_table[i].recv_msg))
649 			ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
650 	}
651 }
652 
653 static void intf_free(struct kref *ref)
654 {
655 	ipmi_smi_t intf = container_of(ref, struct ipmi_smi, refcount);
656 
657 	clean_up_interface_data(intf);
658 	kfree(intf);
659 }
660 
661 struct watcher_entry {
662 	int              intf_num;
663 	ipmi_smi_t       intf;
664 	struct list_head link;
665 };
666 
667 int ipmi_smi_watcher_register(struct ipmi_smi_watcher *watcher)
668 {
669 	ipmi_smi_t intf;
670 	LIST_HEAD(to_deliver);
671 	struct watcher_entry *e, *e2;
672 
673 	mutex_lock(&smi_watchers_mutex);
674 
675 	mutex_lock(&ipmi_interfaces_mutex);
676 
677 	/* Build a list of things to deliver. */
678 	list_for_each_entry(intf, &ipmi_interfaces, link) {
679 		if (intf->intf_num == -1)
680 			continue;
681 		e = kmalloc(sizeof(*e), GFP_KERNEL);
682 		if (!e)
683 			goto out_err;
684 		kref_get(&intf->refcount);
685 		e->intf = intf;
686 		e->intf_num = intf->intf_num;
687 		list_add_tail(&e->link, &to_deliver);
688 	}
689 
690 	/* We will succeed, so add it to the list. */
691 	list_add(&watcher->link, &smi_watchers);
692 
693 	mutex_unlock(&ipmi_interfaces_mutex);
694 
695 	list_for_each_entry_safe(e, e2, &to_deliver, link) {
696 		list_del(&e->link);
697 		watcher->new_smi(e->intf_num, e->intf->si_dev);
698 		kref_put(&e->intf->refcount, intf_free);
699 		kfree(e);
700 	}
701 
702 	mutex_unlock(&smi_watchers_mutex);
703 
704 	return 0;
705 
706  out_err:
707 	mutex_unlock(&ipmi_interfaces_mutex);
708 	mutex_unlock(&smi_watchers_mutex);
709 	list_for_each_entry_safe(e, e2, &to_deliver, link) {
710 		list_del(&e->link);
711 		kref_put(&e->intf->refcount, intf_free);
712 		kfree(e);
713 	}
714 	return -ENOMEM;
715 }
716 EXPORT_SYMBOL(ipmi_smi_watcher_register);
717 
718 int ipmi_smi_watcher_unregister(struct ipmi_smi_watcher *watcher)
719 {
720 	mutex_lock(&smi_watchers_mutex);
721 	list_del(&(watcher->link));
722 	mutex_unlock(&smi_watchers_mutex);
723 	return 0;
724 }
725 EXPORT_SYMBOL(ipmi_smi_watcher_unregister);
726 
727 /*
728  * Must be called with smi_watchers_mutex held.
729  */
730 static void
731 call_smi_watchers(int i, struct device *dev)
732 {
733 	struct ipmi_smi_watcher *w;
734 
735 	list_for_each_entry(w, &smi_watchers, link) {
736 		if (try_module_get(w->owner)) {
737 			w->new_smi(i, dev);
738 			module_put(w->owner);
739 		}
740 	}
741 }
742 
743 static int
744 ipmi_addr_equal(struct ipmi_addr *addr1, struct ipmi_addr *addr2)
745 {
746 	if (addr1->addr_type != addr2->addr_type)
747 		return 0;
748 
749 	if (addr1->channel != addr2->channel)
750 		return 0;
751 
752 	if (addr1->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
753 		struct ipmi_system_interface_addr *smi_addr1
754 		    = (struct ipmi_system_interface_addr *) addr1;
755 		struct ipmi_system_interface_addr *smi_addr2
756 		    = (struct ipmi_system_interface_addr *) addr2;
757 		return (smi_addr1->lun == smi_addr2->lun);
758 	}
759 
760 	if (is_ipmb_addr(addr1) || is_ipmb_bcast_addr(addr1)) {
761 		struct ipmi_ipmb_addr *ipmb_addr1
762 		    = (struct ipmi_ipmb_addr *) addr1;
763 		struct ipmi_ipmb_addr *ipmb_addr2
764 		    = (struct ipmi_ipmb_addr *) addr2;
765 
766 		return ((ipmb_addr1->slave_addr == ipmb_addr2->slave_addr)
767 			&& (ipmb_addr1->lun == ipmb_addr2->lun));
768 	}
769 
770 	if (is_lan_addr(addr1)) {
771 		struct ipmi_lan_addr *lan_addr1
772 			= (struct ipmi_lan_addr *) addr1;
773 		struct ipmi_lan_addr *lan_addr2
774 		    = (struct ipmi_lan_addr *) addr2;
775 
776 		return ((lan_addr1->remote_SWID == lan_addr2->remote_SWID)
777 			&& (lan_addr1->local_SWID == lan_addr2->local_SWID)
778 			&& (lan_addr1->session_handle
779 			    == lan_addr2->session_handle)
780 			&& (lan_addr1->lun == lan_addr2->lun));
781 	}
782 
783 	return 1;
784 }
785 
786 int ipmi_validate_addr(struct ipmi_addr *addr, int len)
787 {
788 	if (len < sizeof(struct ipmi_system_interface_addr))
789 		return -EINVAL;
790 
791 	if (addr->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
792 		if (addr->channel != IPMI_BMC_CHANNEL)
793 			return -EINVAL;
794 		return 0;
795 	}
796 
797 	if ((addr->channel == IPMI_BMC_CHANNEL)
798 	    || (addr->channel >= IPMI_MAX_CHANNELS)
799 	    || (addr->channel < 0))
800 		return -EINVAL;
801 
802 	if (is_ipmb_addr(addr) || is_ipmb_bcast_addr(addr)) {
803 		if (len < sizeof(struct ipmi_ipmb_addr))
804 			return -EINVAL;
805 		return 0;
806 	}
807 
808 	if (is_lan_addr(addr)) {
809 		if (len < sizeof(struct ipmi_lan_addr))
810 			return -EINVAL;
811 		return 0;
812 	}
813 
814 	return -EINVAL;
815 }
816 EXPORT_SYMBOL(ipmi_validate_addr);
817 
818 unsigned int ipmi_addr_length(int addr_type)
819 {
820 	if (addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
821 		return sizeof(struct ipmi_system_interface_addr);
822 
823 	if ((addr_type == IPMI_IPMB_ADDR_TYPE)
824 			|| (addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE))
825 		return sizeof(struct ipmi_ipmb_addr);
826 
827 	if (addr_type == IPMI_LAN_ADDR_TYPE)
828 		return sizeof(struct ipmi_lan_addr);
829 
830 	return 0;
831 }
832 EXPORT_SYMBOL(ipmi_addr_length);
833 
834 static void deliver_response(struct ipmi_recv_msg *msg)
835 {
836 	if (!msg->user) {
837 		ipmi_smi_t    intf = msg->user_msg_data;
838 
839 		/* Special handling for NULL users. */
840 		if (intf->null_user_handler) {
841 			intf->null_user_handler(intf, msg);
842 			ipmi_inc_stat(intf, handled_local_responses);
843 		} else {
844 			/* No handler, so give up. */
845 			ipmi_inc_stat(intf, unhandled_local_responses);
846 		}
847 		ipmi_free_recv_msg(msg);
848 	} else if (!oops_in_progress) {
849 		/*
850 		 * If we are running in the panic context, calling the
851 		 * receive handler doesn't much meaning and has a deadlock
852 		 * risk.  At this moment, simply skip it in that case.
853 		 */
854 
855 		ipmi_user_t user = msg->user;
856 		user->handler->ipmi_recv_hndl(msg, user->handler_data);
857 	}
858 }
859 
860 static void
861 deliver_err_response(struct ipmi_recv_msg *msg, int err)
862 {
863 	msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
864 	msg->msg_data[0] = err;
865 	msg->msg.netfn |= 1; /* Convert to a response. */
866 	msg->msg.data_len = 1;
867 	msg->msg.data = msg->msg_data;
868 	deliver_response(msg);
869 }
870 
871 /*
872  * Find the next sequence number not being used and add the given
873  * message with the given timeout to the sequence table.  This must be
874  * called with the interface's seq_lock held.
875  */
876 static int intf_next_seq(ipmi_smi_t           intf,
877 			 struct ipmi_recv_msg *recv_msg,
878 			 unsigned long        timeout,
879 			 int                  retries,
880 			 int                  broadcast,
881 			 unsigned char        *seq,
882 			 long                 *seqid)
883 {
884 	int          rv = 0;
885 	unsigned int i;
886 
887 	for (i = intf->curr_seq; (i+1)%IPMI_IPMB_NUM_SEQ != intf->curr_seq;
888 					i = (i+1)%IPMI_IPMB_NUM_SEQ) {
889 		if (!intf->seq_table[i].inuse)
890 			break;
891 	}
892 
893 	if (!intf->seq_table[i].inuse) {
894 		intf->seq_table[i].recv_msg = recv_msg;
895 
896 		/*
897 		 * Start with the maximum timeout, when the send response
898 		 * comes in we will start the real timer.
899 		 */
900 		intf->seq_table[i].timeout = MAX_MSG_TIMEOUT;
901 		intf->seq_table[i].orig_timeout = timeout;
902 		intf->seq_table[i].retries_left = retries;
903 		intf->seq_table[i].broadcast = broadcast;
904 		intf->seq_table[i].inuse = 1;
905 		intf->seq_table[i].seqid = NEXT_SEQID(intf->seq_table[i].seqid);
906 		*seq = i;
907 		*seqid = intf->seq_table[i].seqid;
908 		intf->curr_seq = (i+1)%IPMI_IPMB_NUM_SEQ;
909 		need_waiter(intf);
910 	} else {
911 		rv = -EAGAIN;
912 	}
913 
914 	return rv;
915 }
916 
917 /*
918  * Return the receive message for the given sequence number and
919  * release the sequence number so it can be reused.  Some other data
920  * is passed in to be sure the message matches up correctly (to help
921  * guard against message coming in after their timeout and the
922  * sequence number being reused).
923  */
924 static int intf_find_seq(ipmi_smi_t           intf,
925 			 unsigned char        seq,
926 			 short                channel,
927 			 unsigned char        cmd,
928 			 unsigned char        netfn,
929 			 struct ipmi_addr     *addr,
930 			 struct ipmi_recv_msg **recv_msg)
931 {
932 	int           rv = -ENODEV;
933 	unsigned long flags;
934 
935 	if (seq >= IPMI_IPMB_NUM_SEQ)
936 		return -EINVAL;
937 
938 	spin_lock_irqsave(&(intf->seq_lock), flags);
939 	if (intf->seq_table[seq].inuse) {
940 		struct ipmi_recv_msg *msg = intf->seq_table[seq].recv_msg;
941 
942 		if ((msg->addr.channel == channel) && (msg->msg.cmd == cmd)
943 				&& (msg->msg.netfn == netfn)
944 				&& (ipmi_addr_equal(addr, &(msg->addr)))) {
945 			*recv_msg = msg;
946 			intf->seq_table[seq].inuse = 0;
947 			rv = 0;
948 		}
949 	}
950 	spin_unlock_irqrestore(&(intf->seq_lock), flags);
951 
952 	return rv;
953 }
954 
955 
956 /* Start the timer for a specific sequence table entry. */
957 static int intf_start_seq_timer(ipmi_smi_t intf,
958 				long       msgid)
959 {
960 	int           rv = -ENODEV;
961 	unsigned long flags;
962 	unsigned char seq;
963 	unsigned long seqid;
964 
965 
966 	GET_SEQ_FROM_MSGID(msgid, seq, seqid);
967 
968 	spin_lock_irqsave(&(intf->seq_lock), flags);
969 	/*
970 	 * We do this verification because the user can be deleted
971 	 * while a message is outstanding.
972 	 */
973 	if ((intf->seq_table[seq].inuse)
974 				&& (intf->seq_table[seq].seqid == seqid)) {
975 		struct seq_table *ent = &(intf->seq_table[seq]);
976 		ent->timeout = ent->orig_timeout;
977 		rv = 0;
978 	}
979 	spin_unlock_irqrestore(&(intf->seq_lock), flags);
980 
981 	return rv;
982 }
983 
984 /* Got an error for the send message for a specific sequence number. */
985 static int intf_err_seq(ipmi_smi_t   intf,
986 			long         msgid,
987 			unsigned int err)
988 {
989 	int                  rv = -ENODEV;
990 	unsigned long        flags;
991 	unsigned char        seq;
992 	unsigned long        seqid;
993 	struct ipmi_recv_msg *msg = NULL;
994 
995 
996 	GET_SEQ_FROM_MSGID(msgid, seq, seqid);
997 
998 	spin_lock_irqsave(&(intf->seq_lock), flags);
999 	/*
1000 	 * We do this verification because the user can be deleted
1001 	 * while a message is outstanding.
1002 	 */
1003 	if ((intf->seq_table[seq].inuse)
1004 				&& (intf->seq_table[seq].seqid == seqid)) {
1005 		struct seq_table *ent = &(intf->seq_table[seq]);
1006 
1007 		ent->inuse = 0;
1008 		msg = ent->recv_msg;
1009 		rv = 0;
1010 	}
1011 	spin_unlock_irqrestore(&(intf->seq_lock), flags);
1012 
1013 	if (msg)
1014 		deliver_err_response(msg, err);
1015 
1016 	return rv;
1017 }
1018 
1019 
1020 int ipmi_create_user(unsigned int          if_num,
1021 		     const struct ipmi_user_hndl *handler,
1022 		     void                  *handler_data,
1023 		     ipmi_user_t           *user)
1024 {
1025 	unsigned long flags;
1026 	ipmi_user_t   new_user;
1027 	int           rv = 0;
1028 	ipmi_smi_t    intf;
1029 
1030 	/*
1031 	 * There is no module usecount here, because it's not
1032 	 * required.  Since this can only be used by and called from
1033 	 * other modules, they will implicitly use this module, and
1034 	 * thus this can't be removed unless the other modules are
1035 	 * removed.
1036 	 */
1037 
1038 	if (handler == NULL)
1039 		return -EINVAL;
1040 
1041 	/*
1042 	 * Make sure the driver is actually initialized, this handles
1043 	 * problems with initialization order.
1044 	 */
1045 	if (!initialized) {
1046 		rv = ipmi_init_msghandler();
1047 		if (rv)
1048 			return rv;
1049 
1050 		/*
1051 		 * The init code doesn't return an error if it was turned
1052 		 * off, but it won't initialize.  Check that.
1053 		 */
1054 		if (!initialized)
1055 			return -ENODEV;
1056 	}
1057 
1058 	new_user = kmalloc(sizeof(*new_user), GFP_KERNEL);
1059 	if (!new_user)
1060 		return -ENOMEM;
1061 
1062 	mutex_lock(&ipmi_interfaces_mutex);
1063 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
1064 		if (intf->intf_num == if_num)
1065 			goto found;
1066 	}
1067 	/* Not found, return an error */
1068 	rv = -EINVAL;
1069 	goto out_kfree;
1070 
1071  found:
1072 	/* Note that each existing user holds a refcount to the interface. */
1073 	kref_get(&intf->refcount);
1074 
1075 	kref_init(&new_user->refcount);
1076 	new_user->handler = handler;
1077 	new_user->handler_data = handler_data;
1078 	new_user->intf = intf;
1079 	new_user->gets_events = false;
1080 
1081 	if (!try_module_get(intf->handlers->owner)) {
1082 		rv = -ENODEV;
1083 		goto out_kref;
1084 	}
1085 
1086 	if (intf->handlers->inc_usecount) {
1087 		rv = intf->handlers->inc_usecount(intf->send_info);
1088 		if (rv) {
1089 			module_put(intf->handlers->owner);
1090 			goto out_kref;
1091 		}
1092 	}
1093 
1094 	/*
1095 	 * Hold the lock so intf->handlers is guaranteed to be good
1096 	 * until now
1097 	 */
1098 	mutex_unlock(&ipmi_interfaces_mutex);
1099 
1100 	new_user->valid = true;
1101 	spin_lock_irqsave(&intf->seq_lock, flags);
1102 	list_add_rcu(&new_user->link, &intf->users);
1103 	spin_unlock_irqrestore(&intf->seq_lock, flags);
1104 	if (handler->ipmi_watchdog_pretimeout) {
1105 		/* User wants pretimeouts, so make sure to watch for them. */
1106 		if (atomic_inc_return(&intf->event_waiters) == 1)
1107 			need_waiter(intf);
1108 	}
1109 	*user = new_user;
1110 	return 0;
1111 
1112 out_kref:
1113 	kref_put(&intf->refcount, intf_free);
1114 out_kfree:
1115 	mutex_unlock(&ipmi_interfaces_mutex);
1116 	kfree(new_user);
1117 	return rv;
1118 }
1119 EXPORT_SYMBOL(ipmi_create_user);
1120 
1121 int ipmi_get_smi_info(int if_num, struct ipmi_smi_info *data)
1122 {
1123 	int           rv = 0;
1124 	ipmi_smi_t    intf;
1125 	const struct ipmi_smi_handlers *handlers;
1126 
1127 	mutex_lock(&ipmi_interfaces_mutex);
1128 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
1129 		if (intf->intf_num == if_num)
1130 			goto found;
1131 	}
1132 	/* Not found, return an error */
1133 	rv = -EINVAL;
1134 	mutex_unlock(&ipmi_interfaces_mutex);
1135 	return rv;
1136 
1137 found:
1138 	handlers = intf->handlers;
1139 	rv = -ENOSYS;
1140 	if (handlers->get_smi_info)
1141 		rv = handlers->get_smi_info(intf->send_info, data);
1142 	mutex_unlock(&ipmi_interfaces_mutex);
1143 
1144 	return rv;
1145 }
1146 EXPORT_SYMBOL(ipmi_get_smi_info);
1147 
1148 static void free_user(struct kref *ref)
1149 {
1150 	ipmi_user_t user = container_of(ref, struct ipmi_user, refcount);
1151 	kfree(user);
1152 }
1153 
1154 int ipmi_destroy_user(ipmi_user_t user)
1155 {
1156 	ipmi_smi_t       intf = user->intf;
1157 	int              i;
1158 	unsigned long    flags;
1159 	struct cmd_rcvr  *rcvr;
1160 	struct cmd_rcvr  *rcvrs = NULL;
1161 
1162 	user->valid = false;
1163 
1164 	if (user->handler->ipmi_watchdog_pretimeout)
1165 		atomic_dec(&intf->event_waiters);
1166 
1167 	if (user->gets_events)
1168 		atomic_dec(&intf->event_waiters);
1169 
1170 	/* Remove the user from the interface's sequence table. */
1171 	spin_lock_irqsave(&intf->seq_lock, flags);
1172 	list_del_rcu(&user->link);
1173 
1174 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
1175 		if (intf->seq_table[i].inuse
1176 		    && (intf->seq_table[i].recv_msg->user == user)) {
1177 			intf->seq_table[i].inuse = 0;
1178 			ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
1179 		}
1180 	}
1181 	spin_unlock_irqrestore(&intf->seq_lock, flags);
1182 
1183 	/*
1184 	 * Remove the user from the command receiver's table.  First
1185 	 * we build a list of everything (not using the standard link,
1186 	 * since other things may be using it till we do
1187 	 * synchronize_rcu()) then free everything in that list.
1188 	 */
1189 	mutex_lock(&intf->cmd_rcvrs_mutex);
1190 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) {
1191 		if (rcvr->user == user) {
1192 			list_del_rcu(&rcvr->link);
1193 			rcvr->next = rcvrs;
1194 			rcvrs = rcvr;
1195 		}
1196 	}
1197 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1198 	synchronize_rcu();
1199 	while (rcvrs) {
1200 		rcvr = rcvrs;
1201 		rcvrs = rcvr->next;
1202 		kfree(rcvr);
1203 	}
1204 
1205 	mutex_lock(&ipmi_interfaces_mutex);
1206 	if (intf->handlers) {
1207 		module_put(intf->handlers->owner);
1208 		if (intf->handlers->dec_usecount)
1209 			intf->handlers->dec_usecount(intf->send_info);
1210 	}
1211 	mutex_unlock(&ipmi_interfaces_mutex);
1212 
1213 	kref_put(&intf->refcount, intf_free);
1214 
1215 	kref_put(&user->refcount, free_user);
1216 
1217 	return 0;
1218 }
1219 EXPORT_SYMBOL(ipmi_destroy_user);
1220 
1221 int ipmi_get_version(ipmi_user_t   user,
1222 		     unsigned char *major,
1223 		     unsigned char *minor)
1224 {
1225 	struct ipmi_device_id id;
1226 	int rv;
1227 
1228 	rv = bmc_get_device_id(user->intf, NULL, &id, NULL, NULL);
1229 	if (rv)
1230 		return rv;
1231 
1232 	*major = ipmi_version_major(&id);
1233 	*minor = ipmi_version_minor(&id);
1234 
1235 	return 0;
1236 }
1237 EXPORT_SYMBOL(ipmi_get_version);
1238 
1239 int ipmi_set_my_address(ipmi_user_t   user,
1240 			unsigned int  channel,
1241 			unsigned char address)
1242 {
1243 	if (channel >= IPMI_MAX_CHANNELS)
1244 		return -EINVAL;
1245 	user->intf->addrinfo[channel].address = address;
1246 	return 0;
1247 }
1248 EXPORT_SYMBOL(ipmi_set_my_address);
1249 
1250 int ipmi_get_my_address(ipmi_user_t   user,
1251 			unsigned int  channel,
1252 			unsigned char *address)
1253 {
1254 	if (channel >= IPMI_MAX_CHANNELS)
1255 		return -EINVAL;
1256 	*address = user->intf->addrinfo[channel].address;
1257 	return 0;
1258 }
1259 EXPORT_SYMBOL(ipmi_get_my_address);
1260 
1261 int ipmi_set_my_LUN(ipmi_user_t   user,
1262 		    unsigned int  channel,
1263 		    unsigned char LUN)
1264 {
1265 	if (channel >= IPMI_MAX_CHANNELS)
1266 		return -EINVAL;
1267 	user->intf->addrinfo[channel].lun = LUN & 0x3;
1268 	return 0;
1269 }
1270 EXPORT_SYMBOL(ipmi_set_my_LUN);
1271 
1272 int ipmi_get_my_LUN(ipmi_user_t   user,
1273 		    unsigned int  channel,
1274 		    unsigned char *address)
1275 {
1276 	if (channel >= IPMI_MAX_CHANNELS)
1277 		return -EINVAL;
1278 	*address = user->intf->addrinfo[channel].lun;
1279 	return 0;
1280 }
1281 EXPORT_SYMBOL(ipmi_get_my_LUN);
1282 
1283 int ipmi_get_maintenance_mode(ipmi_user_t user)
1284 {
1285 	int           mode;
1286 	unsigned long flags;
1287 
1288 	spin_lock_irqsave(&user->intf->maintenance_mode_lock, flags);
1289 	mode = user->intf->maintenance_mode;
1290 	spin_unlock_irqrestore(&user->intf->maintenance_mode_lock, flags);
1291 
1292 	return mode;
1293 }
1294 EXPORT_SYMBOL(ipmi_get_maintenance_mode);
1295 
1296 static void maintenance_mode_update(ipmi_smi_t intf)
1297 {
1298 	if (intf->handlers->set_maintenance_mode)
1299 		intf->handlers->set_maintenance_mode(
1300 			intf->send_info, intf->maintenance_mode_enable);
1301 }
1302 
1303 int ipmi_set_maintenance_mode(ipmi_user_t user, int mode)
1304 {
1305 	int           rv = 0;
1306 	unsigned long flags;
1307 	ipmi_smi_t    intf = user->intf;
1308 
1309 	spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
1310 	if (intf->maintenance_mode != mode) {
1311 		switch (mode) {
1312 		case IPMI_MAINTENANCE_MODE_AUTO:
1313 			intf->maintenance_mode_enable
1314 				= (intf->auto_maintenance_timeout > 0);
1315 			break;
1316 
1317 		case IPMI_MAINTENANCE_MODE_OFF:
1318 			intf->maintenance_mode_enable = false;
1319 			break;
1320 
1321 		case IPMI_MAINTENANCE_MODE_ON:
1322 			intf->maintenance_mode_enable = true;
1323 			break;
1324 
1325 		default:
1326 			rv = -EINVAL;
1327 			goto out_unlock;
1328 		}
1329 		intf->maintenance_mode = mode;
1330 
1331 		maintenance_mode_update(intf);
1332 	}
1333  out_unlock:
1334 	spin_unlock_irqrestore(&intf->maintenance_mode_lock, flags);
1335 
1336 	return rv;
1337 }
1338 EXPORT_SYMBOL(ipmi_set_maintenance_mode);
1339 
1340 int ipmi_set_gets_events(ipmi_user_t user, bool val)
1341 {
1342 	unsigned long        flags;
1343 	ipmi_smi_t           intf = user->intf;
1344 	struct ipmi_recv_msg *msg, *msg2;
1345 	struct list_head     msgs;
1346 
1347 	INIT_LIST_HEAD(&msgs);
1348 
1349 	spin_lock_irqsave(&intf->events_lock, flags);
1350 	if (user->gets_events == val)
1351 		goto out;
1352 
1353 	user->gets_events = val;
1354 
1355 	if (val) {
1356 		if (atomic_inc_return(&intf->event_waiters) == 1)
1357 			need_waiter(intf);
1358 	} else {
1359 		atomic_dec(&intf->event_waiters);
1360 	}
1361 
1362 	if (intf->delivering_events)
1363 		/*
1364 		 * Another thread is delivering events for this, so
1365 		 * let it handle any new events.
1366 		 */
1367 		goto out;
1368 
1369 	/* Deliver any queued events. */
1370 	while (user->gets_events && !list_empty(&intf->waiting_events)) {
1371 		list_for_each_entry_safe(msg, msg2, &intf->waiting_events, link)
1372 			list_move_tail(&msg->link, &msgs);
1373 		intf->waiting_events_count = 0;
1374 		if (intf->event_msg_printed) {
1375 			dev_warn(intf->si_dev,
1376 				 PFX "Event queue no longer full\n");
1377 			intf->event_msg_printed = 0;
1378 		}
1379 
1380 		intf->delivering_events = 1;
1381 		spin_unlock_irqrestore(&intf->events_lock, flags);
1382 
1383 		list_for_each_entry_safe(msg, msg2, &msgs, link) {
1384 			msg->user = user;
1385 			kref_get(&user->refcount);
1386 			deliver_response(msg);
1387 		}
1388 
1389 		spin_lock_irqsave(&intf->events_lock, flags);
1390 		intf->delivering_events = 0;
1391 	}
1392 
1393  out:
1394 	spin_unlock_irqrestore(&intf->events_lock, flags);
1395 
1396 	return 0;
1397 }
1398 EXPORT_SYMBOL(ipmi_set_gets_events);
1399 
1400 static struct cmd_rcvr *find_cmd_rcvr(ipmi_smi_t    intf,
1401 				      unsigned char netfn,
1402 				      unsigned char cmd,
1403 				      unsigned char chan)
1404 {
1405 	struct cmd_rcvr *rcvr;
1406 
1407 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) {
1408 		if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
1409 					&& (rcvr->chans & (1 << chan)))
1410 			return rcvr;
1411 	}
1412 	return NULL;
1413 }
1414 
1415 static int is_cmd_rcvr_exclusive(ipmi_smi_t    intf,
1416 				 unsigned char netfn,
1417 				 unsigned char cmd,
1418 				 unsigned int  chans)
1419 {
1420 	struct cmd_rcvr *rcvr;
1421 
1422 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) {
1423 		if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
1424 					&& (rcvr->chans & chans))
1425 			return 0;
1426 	}
1427 	return 1;
1428 }
1429 
1430 int ipmi_register_for_cmd(ipmi_user_t   user,
1431 			  unsigned char netfn,
1432 			  unsigned char cmd,
1433 			  unsigned int  chans)
1434 {
1435 	ipmi_smi_t      intf = user->intf;
1436 	struct cmd_rcvr *rcvr;
1437 	int             rv = 0;
1438 
1439 
1440 	rcvr = kmalloc(sizeof(*rcvr), GFP_KERNEL);
1441 	if (!rcvr)
1442 		return -ENOMEM;
1443 	rcvr->cmd = cmd;
1444 	rcvr->netfn = netfn;
1445 	rcvr->chans = chans;
1446 	rcvr->user = user;
1447 
1448 	mutex_lock(&intf->cmd_rcvrs_mutex);
1449 	/* Make sure the command/netfn is not already registered. */
1450 	if (!is_cmd_rcvr_exclusive(intf, netfn, cmd, chans)) {
1451 		rv = -EBUSY;
1452 		goto out_unlock;
1453 	}
1454 
1455 	if (atomic_inc_return(&intf->event_waiters) == 1)
1456 		need_waiter(intf);
1457 
1458 	list_add_rcu(&rcvr->link, &intf->cmd_rcvrs);
1459 
1460  out_unlock:
1461 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1462 	if (rv)
1463 		kfree(rcvr);
1464 
1465 	return rv;
1466 }
1467 EXPORT_SYMBOL(ipmi_register_for_cmd);
1468 
1469 int ipmi_unregister_for_cmd(ipmi_user_t   user,
1470 			    unsigned char netfn,
1471 			    unsigned char cmd,
1472 			    unsigned int  chans)
1473 {
1474 	ipmi_smi_t      intf = user->intf;
1475 	struct cmd_rcvr *rcvr;
1476 	struct cmd_rcvr *rcvrs = NULL;
1477 	int i, rv = -ENOENT;
1478 
1479 	mutex_lock(&intf->cmd_rcvrs_mutex);
1480 	for (i = 0; i < IPMI_NUM_CHANNELS; i++) {
1481 		if (((1 << i) & chans) == 0)
1482 			continue;
1483 		rcvr = find_cmd_rcvr(intf, netfn, cmd, i);
1484 		if (rcvr == NULL)
1485 			continue;
1486 		if (rcvr->user == user) {
1487 			rv = 0;
1488 			rcvr->chans &= ~chans;
1489 			if (rcvr->chans == 0) {
1490 				list_del_rcu(&rcvr->link);
1491 				rcvr->next = rcvrs;
1492 				rcvrs = rcvr;
1493 			}
1494 		}
1495 	}
1496 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1497 	synchronize_rcu();
1498 	while (rcvrs) {
1499 		atomic_dec(&intf->event_waiters);
1500 		rcvr = rcvrs;
1501 		rcvrs = rcvr->next;
1502 		kfree(rcvr);
1503 	}
1504 	return rv;
1505 }
1506 EXPORT_SYMBOL(ipmi_unregister_for_cmd);
1507 
1508 static unsigned char
1509 ipmb_checksum(unsigned char *data, int size)
1510 {
1511 	unsigned char csum = 0;
1512 
1513 	for (; size > 0; size--, data++)
1514 		csum += *data;
1515 
1516 	return -csum;
1517 }
1518 
1519 static inline void format_ipmb_msg(struct ipmi_smi_msg   *smi_msg,
1520 				   struct kernel_ipmi_msg *msg,
1521 				   struct ipmi_ipmb_addr *ipmb_addr,
1522 				   long                  msgid,
1523 				   unsigned char         ipmb_seq,
1524 				   int                   broadcast,
1525 				   unsigned char         source_address,
1526 				   unsigned char         source_lun)
1527 {
1528 	int i = broadcast;
1529 
1530 	/* Format the IPMB header data. */
1531 	smi_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
1532 	smi_msg->data[1] = IPMI_SEND_MSG_CMD;
1533 	smi_msg->data[2] = ipmb_addr->channel;
1534 	if (broadcast)
1535 		smi_msg->data[3] = 0;
1536 	smi_msg->data[i+3] = ipmb_addr->slave_addr;
1537 	smi_msg->data[i+4] = (msg->netfn << 2) | (ipmb_addr->lun & 0x3);
1538 	smi_msg->data[i+5] = ipmb_checksum(&(smi_msg->data[i+3]), 2);
1539 	smi_msg->data[i+6] = source_address;
1540 	smi_msg->data[i+7] = (ipmb_seq << 2) | source_lun;
1541 	smi_msg->data[i+8] = msg->cmd;
1542 
1543 	/* Now tack on the data to the message. */
1544 	if (msg->data_len > 0)
1545 		memcpy(&(smi_msg->data[i+9]), msg->data,
1546 		       msg->data_len);
1547 	smi_msg->data_size = msg->data_len + 9;
1548 
1549 	/* Now calculate the checksum and tack it on. */
1550 	smi_msg->data[i+smi_msg->data_size]
1551 		= ipmb_checksum(&(smi_msg->data[i+6]),
1552 				smi_msg->data_size-6);
1553 
1554 	/*
1555 	 * Add on the checksum size and the offset from the
1556 	 * broadcast.
1557 	 */
1558 	smi_msg->data_size += 1 + i;
1559 
1560 	smi_msg->msgid = msgid;
1561 }
1562 
1563 static inline void format_lan_msg(struct ipmi_smi_msg   *smi_msg,
1564 				  struct kernel_ipmi_msg *msg,
1565 				  struct ipmi_lan_addr  *lan_addr,
1566 				  long                  msgid,
1567 				  unsigned char         ipmb_seq,
1568 				  unsigned char         source_lun)
1569 {
1570 	/* Format the IPMB header data. */
1571 	smi_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
1572 	smi_msg->data[1] = IPMI_SEND_MSG_CMD;
1573 	smi_msg->data[2] = lan_addr->channel;
1574 	smi_msg->data[3] = lan_addr->session_handle;
1575 	smi_msg->data[4] = lan_addr->remote_SWID;
1576 	smi_msg->data[5] = (msg->netfn << 2) | (lan_addr->lun & 0x3);
1577 	smi_msg->data[6] = ipmb_checksum(&(smi_msg->data[4]), 2);
1578 	smi_msg->data[7] = lan_addr->local_SWID;
1579 	smi_msg->data[8] = (ipmb_seq << 2) | source_lun;
1580 	smi_msg->data[9] = msg->cmd;
1581 
1582 	/* Now tack on the data to the message. */
1583 	if (msg->data_len > 0)
1584 		memcpy(&(smi_msg->data[10]), msg->data,
1585 		       msg->data_len);
1586 	smi_msg->data_size = msg->data_len + 10;
1587 
1588 	/* Now calculate the checksum and tack it on. */
1589 	smi_msg->data[smi_msg->data_size]
1590 		= ipmb_checksum(&(smi_msg->data[7]),
1591 				smi_msg->data_size-7);
1592 
1593 	/*
1594 	 * Add on the checksum size and the offset from the
1595 	 * broadcast.
1596 	 */
1597 	smi_msg->data_size += 1;
1598 
1599 	smi_msg->msgid = msgid;
1600 }
1601 
1602 static struct ipmi_smi_msg *smi_add_send_msg(ipmi_smi_t intf,
1603 					     struct ipmi_smi_msg *smi_msg,
1604 					     int priority)
1605 {
1606 	if (intf->curr_msg) {
1607 		if (priority > 0)
1608 			list_add_tail(&smi_msg->link, &intf->hp_xmit_msgs);
1609 		else
1610 			list_add_tail(&smi_msg->link, &intf->xmit_msgs);
1611 		smi_msg = NULL;
1612 	} else {
1613 		intf->curr_msg = smi_msg;
1614 	}
1615 
1616 	return smi_msg;
1617 }
1618 
1619 
1620 static void smi_send(ipmi_smi_t intf, const struct ipmi_smi_handlers *handlers,
1621 		     struct ipmi_smi_msg *smi_msg, int priority)
1622 {
1623 	int run_to_completion = intf->run_to_completion;
1624 
1625 	if (run_to_completion) {
1626 		smi_msg = smi_add_send_msg(intf, smi_msg, priority);
1627 	} else {
1628 		unsigned long flags;
1629 
1630 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
1631 		smi_msg = smi_add_send_msg(intf, smi_msg, priority);
1632 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
1633 	}
1634 
1635 	if (smi_msg)
1636 		handlers->sender(intf->send_info, smi_msg);
1637 }
1638 
1639 /*
1640  * Separate from ipmi_request so that the user does not have to be
1641  * supplied in certain circumstances (mainly at panic time).  If
1642  * messages are supplied, they will be freed, even if an error
1643  * occurs.
1644  */
1645 static int i_ipmi_request(ipmi_user_t          user,
1646 			  ipmi_smi_t           intf,
1647 			  struct ipmi_addr     *addr,
1648 			  long                 msgid,
1649 			  struct kernel_ipmi_msg *msg,
1650 			  void                 *user_msg_data,
1651 			  void                 *supplied_smi,
1652 			  struct ipmi_recv_msg *supplied_recv,
1653 			  int                  priority,
1654 			  unsigned char        source_address,
1655 			  unsigned char        source_lun,
1656 			  int                  retries,
1657 			  unsigned int         retry_time_ms)
1658 {
1659 	int                      rv = 0;
1660 	struct ipmi_smi_msg      *smi_msg;
1661 	struct ipmi_recv_msg     *recv_msg;
1662 	unsigned long            flags;
1663 
1664 
1665 	if (supplied_recv)
1666 		recv_msg = supplied_recv;
1667 	else {
1668 		recv_msg = ipmi_alloc_recv_msg();
1669 		if (recv_msg == NULL)
1670 			return -ENOMEM;
1671 	}
1672 	recv_msg->user_msg_data = user_msg_data;
1673 
1674 	if (supplied_smi)
1675 		smi_msg = (struct ipmi_smi_msg *) supplied_smi;
1676 	else {
1677 		smi_msg = ipmi_alloc_smi_msg();
1678 		if (smi_msg == NULL) {
1679 			ipmi_free_recv_msg(recv_msg);
1680 			return -ENOMEM;
1681 		}
1682 	}
1683 
1684 	rcu_read_lock();
1685 	if (intf->in_shutdown) {
1686 		rv = -ENODEV;
1687 		goto out_err;
1688 	}
1689 
1690 	recv_msg->user = user;
1691 	if (user)
1692 		kref_get(&user->refcount);
1693 	recv_msg->msgid = msgid;
1694 	/*
1695 	 * Store the message to send in the receive message so timeout
1696 	 * responses can get the proper response data.
1697 	 */
1698 	recv_msg->msg = *msg;
1699 
1700 	if (addr->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
1701 		struct ipmi_system_interface_addr *smi_addr;
1702 
1703 		if (msg->netfn & 1) {
1704 			/* Responses are not allowed to the SMI. */
1705 			rv = -EINVAL;
1706 			goto out_err;
1707 		}
1708 
1709 		smi_addr = (struct ipmi_system_interface_addr *) addr;
1710 		if (smi_addr->lun > 3) {
1711 			ipmi_inc_stat(intf, sent_invalid_commands);
1712 			rv = -EINVAL;
1713 			goto out_err;
1714 		}
1715 
1716 		memcpy(&recv_msg->addr, smi_addr, sizeof(*smi_addr));
1717 
1718 		if ((msg->netfn == IPMI_NETFN_APP_REQUEST)
1719 		    && ((msg->cmd == IPMI_SEND_MSG_CMD)
1720 			|| (msg->cmd == IPMI_GET_MSG_CMD)
1721 			|| (msg->cmd == IPMI_READ_EVENT_MSG_BUFFER_CMD))) {
1722 			/*
1723 			 * We don't let the user do these, since we manage
1724 			 * the sequence numbers.
1725 			 */
1726 			ipmi_inc_stat(intf, sent_invalid_commands);
1727 			rv = -EINVAL;
1728 			goto out_err;
1729 		}
1730 
1731 		if (((msg->netfn == IPMI_NETFN_APP_REQUEST)
1732 		      && ((msg->cmd == IPMI_COLD_RESET_CMD)
1733 			  || (msg->cmd == IPMI_WARM_RESET_CMD)))
1734 		     || (msg->netfn == IPMI_NETFN_FIRMWARE_REQUEST)) {
1735 			spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
1736 			intf->auto_maintenance_timeout
1737 				= IPMI_MAINTENANCE_MODE_TIMEOUT;
1738 			if (!intf->maintenance_mode
1739 			    && !intf->maintenance_mode_enable) {
1740 				intf->maintenance_mode_enable = true;
1741 				maintenance_mode_update(intf);
1742 			}
1743 			spin_unlock_irqrestore(&intf->maintenance_mode_lock,
1744 					       flags);
1745 		}
1746 
1747 		if ((msg->data_len + 2) > IPMI_MAX_MSG_LENGTH) {
1748 			ipmi_inc_stat(intf, sent_invalid_commands);
1749 			rv = -EMSGSIZE;
1750 			goto out_err;
1751 		}
1752 
1753 		smi_msg->data[0] = (msg->netfn << 2) | (smi_addr->lun & 0x3);
1754 		smi_msg->data[1] = msg->cmd;
1755 		smi_msg->msgid = msgid;
1756 		smi_msg->user_data = recv_msg;
1757 		if (msg->data_len > 0)
1758 			memcpy(&(smi_msg->data[2]), msg->data, msg->data_len);
1759 		smi_msg->data_size = msg->data_len + 2;
1760 		ipmi_inc_stat(intf, sent_local_commands);
1761 	} else if (is_ipmb_addr(addr) || is_ipmb_bcast_addr(addr)) {
1762 		struct ipmi_ipmb_addr *ipmb_addr;
1763 		unsigned char         ipmb_seq;
1764 		long                  seqid;
1765 		int                   broadcast = 0;
1766 		struct ipmi_channel   *chans;
1767 
1768 		if (addr->channel >= IPMI_MAX_CHANNELS) {
1769 			ipmi_inc_stat(intf, sent_invalid_commands);
1770 			rv = -EINVAL;
1771 			goto out_err;
1772 		}
1773 
1774 		chans = READ_ONCE(intf->channel_list)->c;
1775 
1776 		if (chans[addr->channel].medium != IPMI_CHANNEL_MEDIUM_IPMB) {
1777 			ipmi_inc_stat(intf, sent_invalid_commands);
1778 			rv = -EINVAL;
1779 			goto out_err;
1780 		}
1781 
1782 		if (retries < 0) {
1783 		    if (addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE)
1784 			retries = 0; /* Don't retry broadcasts. */
1785 		    else
1786 			retries = 4;
1787 		}
1788 		if (addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE) {
1789 		    /*
1790 		     * Broadcasts add a zero at the beginning of the
1791 		     * message, but otherwise is the same as an IPMB
1792 		     * address.
1793 		     */
1794 		    addr->addr_type = IPMI_IPMB_ADDR_TYPE;
1795 		    broadcast = 1;
1796 		}
1797 
1798 
1799 		/* Default to 1 second retries. */
1800 		if (retry_time_ms == 0)
1801 		    retry_time_ms = 1000;
1802 
1803 		/*
1804 		 * 9 for the header and 1 for the checksum, plus
1805 		 * possibly one for the broadcast.
1806 		 */
1807 		if ((msg->data_len + 10 + broadcast) > IPMI_MAX_MSG_LENGTH) {
1808 			ipmi_inc_stat(intf, sent_invalid_commands);
1809 			rv = -EMSGSIZE;
1810 			goto out_err;
1811 		}
1812 
1813 		ipmb_addr = (struct ipmi_ipmb_addr *) addr;
1814 		if (ipmb_addr->lun > 3) {
1815 			ipmi_inc_stat(intf, sent_invalid_commands);
1816 			rv = -EINVAL;
1817 			goto out_err;
1818 		}
1819 
1820 		memcpy(&recv_msg->addr, ipmb_addr, sizeof(*ipmb_addr));
1821 
1822 		if (recv_msg->msg.netfn & 0x1) {
1823 			/*
1824 			 * It's a response, so use the user's sequence
1825 			 * from msgid.
1826 			 */
1827 			ipmi_inc_stat(intf, sent_ipmb_responses);
1828 			format_ipmb_msg(smi_msg, msg, ipmb_addr, msgid,
1829 					msgid, broadcast,
1830 					source_address, source_lun);
1831 
1832 			/*
1833 			 * Save the receive message so we can use it
1834 			 * to deliver the response.
1835 			 */
1836 			smi_msg->user_data = recv_msg;
1837 		} else {
1838 			/* It's a command, so get a sequence for it. */
1839 
1840 			spin_lock_irqsave(&(intf->seq_lock), flags);
1841 
1842 			/*
1843 			 * Create a sequence number with a 1 second
1844 			 * timeout and 4 retries.
1845 			 */
1846 			rv = intf_next_seq(intf,
1847 					   recv_msg,
1848 					   retry_time_ms,
1849 					   retries,
1850 					   broadcast,
1851 					   &ipmb_seq,
1852 					   &seqid);
1853 			if (rv) {
1854 				/*
1855 				 * We have used up all the sequence numbers,
1856 				 * probably, so abort.
1857 				 */
1858 				spin_unlock_irqrestore(&(intf->seq_lock),
1859 						       flags);
1860 				goto out_err;
1861 			}
1862 
1863 			ipmi_inc_stat(intf, sent_ipmb_commands);
1864 
1865 			/*
1866 			 * Store the sequence number in the message,
1867 			 * so that when the send message response
1868 			 * comes back we can start the timer.
1869 			 */
1870 			format_ipmb_msg(smi_msg, msg, ipmb_addr,
1871 					STORE_SEQ_IN_MSGID(ipmb_seq, seqid),
1872 					ipmb_seq, broadcast,
1873 					source_address, source_lun);
1874 
1875 			/*
1876 			 * Copy the message into the recv message data, so we
1877 			 * can retransmit it later if necessary.
1878 			 */
1879 			memcpy(recv_msg->msg_data, smi_msg->data,
1880 			       smi_msg->data_size);
1881 			recv_msg->msg.data = recv_msg->msg_data;
1882 			recv_msg->msg.data_len = smi_msg->data_size;
1883 
1884 			/*
1885 			 * We don't unlock until here, because we need
1886 			 * to copy the completed message into the
1887 			 * recv_msg before we release the lock.
1888 			 * Otherwise, race conditions may bite us.  I
1889 			 * know that's pretty paranoid, but I prefer
1890 			 * to be correct.
1891 			 */
1892 			spin_unlock_irqrestore(&(intf->seq_lock), flags);
1893 		}
1894 	} else if (is_lan_addr(addr)) {
1895 		struct ipmi_lan_addr  *lan_addr;
1896 		unsigned char         ipmb_seq;
1897 		long                  seqid;
1898 		struct ipmi_channel   *chans;
1899 
1900 		if (addr->channel >= IPMI_MAX_CHANNELS) {
1901 			ipmi_inc_stat(intf, sent_invalid_commands);
1902 			rv = -EINVAL;
1903 			goto out_err;
1904 		}
1905 
1906 		chans = READ_ONCE(intf->channel_list)->c;
1907 
1908 		if ((chans[addr->channel].medium
1909 				!= IPMI_CHANNEL_MEDIUM_8023LAN)
1910 		    && (chans[addr->channel].medium
1911 				!= IPMI_CHANNEL_MEDIUM_ASYNC)) {
1912 			ipmi_inc_stat(intf, sent_invalid_commands);
1913 			rv = -EINVAL;
1914 			goto out_err;
1915 		}
1916 
1917 		retries = 4;
1918 
1919 		/* Default to 1 second retries. */
1920 		if (retry_time_ms == 0)
1921 		    retry_time_ms = 1000;
1922 
1923 		/* 11 for the header and 1 for the checksum. */
1924 		if ((msg->data_len + 12) > IPMI_MAX_MSG_LENGTH) {
1925 			ipmi_inc_stat(intf, sent_invalid_commands);
1926 			rv = -EMSGSIZE;
1927 			goto out_err;
1928 		}
1929 
1930 		lan_addr = (struct ipmi_lan_addr *) addr;
1931 		if (lan_addr->lun > 3) {
1932 			ipmi_inc_stat(intf, sent_invalid_commands);
1933 			rv = -EINVAL;
1934 			goto out_err;
1935 		}
1936 
1937 		memcpy(&recv_msg->addr, lan_addr, sizeof(*lan_addr));
1938 
1939 		if (recv_msg->msg.netfn & 0x1) {
1940 			/*
1941 			 * It's a response, so use the user's sequence
1942 			 * from msgid.
1943 			 */
1944 			ipmi_inc_stat(intf, sent_lan_responses);
1945 			format_lan_msg(smi_msg, msg, lan_addr, msgid,
1946 				       msgid, source_lun);
1947 
1948 			/*
1949 			 * Save the receive message so we can use it
1950 			 * to deliver the response.
1951 			 */
1952 			smi_msg->user_data = recv_msg;
1953 		} else {
1954 			/* It's a command, so get a sequence for it. */
1955 
1956 			spin_lock_irqsave(&(intf->seq_lock), flags);
1957 
1958 			/*
1959 			 * Create a sequence number with a 1 second
1960 			 * timeout and 4 retries.
1961 			 */
1962 			rv = intf_next_seq(intf,
1963 					   recv_msg,
1964 					   retry_time_ms,
1965 					   retries,
1966 					   0,
1967 					   &ipmb_seq,
1968 					   &seqid);
1969 			if (rv) {
1970 				/*
1971 				 * We have used up all the sequence numbers,
1972 				 * probably, so abort.
1973 				 */
1974 				spin_unlock_irqrestore(&(intf->seq_lock),
1975 						       flags);
1976 				goto out_err;
1977 			}
1978 
1979 			ipmi_inc_stat(intf, sent_lan_commands);
1980 
1981 			/*
1982 			 * Store the sequence number in the message,
1983 			 * so that when the send message response
1984 			 * comes back we can start the timer.
1985 			 */
1986 			format_lan_msg(smi_msg, msg, lan_addr,
1987 				       STORE_SEQ_IN_MSGID(ipmb_seq, seqid),
1988 				       ipmb_seq, source_lun);
1989 
1990 			/*
1991 			 * Copy the message into the recv message data, so we
1992 			 * can retransmit it later if necessary.
1993 			 */
1994 			memcpy(recv_msg->msg_data, smi_msg->data,
1995 			       smi_msg->data_size);
1996 			recv_msg->msg.data = recv_msg->msg_data;
1997 			recv_msg->msg.data_len = smi_msg->data_size;
1998 
1999 			/*
2000 			 * We don't unlock until here, because we need
2001 			 * to copy the completed message into the
2002 			 * recv_msg before we release the lock.
2003 			 * Otherwise, race conditions may bite us.  I
2004 			 * know that's pretty paranoid, but I prefer
2005 			 * to be correct.
2006 			 */
2007 			spin_unlock_irqrestore(&(intf->seq_lock), flags);
2008 		}
2009 	} else {
2010 	    /* Unknown address type. */
2011 		ipmi_inc_stat(intf, sent_invalid_commands);
2012 		rv = -EINVAL;
2013 		goto out_err;
2014 	}
2015 
2016 #ifdef DEBUG_MSGING
2017 	{
2018 		int m;
2019 		for (m = 0; m < smi_msg->data_size; m++)
2020 			printk(" %2.2x", smi_msg->data[m]);
2021 		printk("\n");
2022 	}
2023 #endif
2024 
2025 	smi_send(intf, intf->handlers, smi_msg, priority);
2026 	rcu_read_unlock();
2027 
2028 	return 0;
2029 
2030  out_err:
2031 	rcu_read_unlock();
2032 	ipmi_free_smi_msg(smi_msg);
2033 	ipmi_free_recv_msg(recv_msg);
2034 	return rv;
2035 }
2036 
2037 static int check_addr(ipmi_smi_t       intf,
2038 		      struct ipmi_addr *addr,
2039 		      unsigned char    *saddr,
2040 		      unsigned char    *lun)
2041 {
2042 	if (addr->channel >= IPMI_MAX_CHANNELS)
2043 		return -EINVAL;
2044 	*lun = intf->addrinfo[addr->channel].lun;
2045 	*saddr = intf->addrinfo[addr->channel].address;
2046 	return 0;
2047 }
2048 
2049 int ipmi_request_settime(ipmi_user_t      user,
2050 			 struct ipmi_addr *addr,
2051 			 long             msgid,
2052 			 struct kernel_ipmi_msg  *msg,
2053 			 void             *user_msg_data,
2054 			 int              priority,
2055 			 int              retries,
2056 			 unsigned int     retry_time_ms)
2057 {
2058 	unsigned char saddr = 0, lun = 0;
2059 	int           rv;
2060 
2061 	if (!user)
2062 		return -EINVAL;
2063 	rv = check_addr(user->intf, addr, &saddr, &lun);
2064 	if (rv)
2065 		return rv;
2066 	return i_ipmi_request(user,
2067 			      user->intf,
2068 			      addr,
2069 			      msgid,
2070 			      msg,
2071 			      user_msg_data,
2072 			      NULL, NULL,
2073 			      priority,
2074 			      saddr,
2075 			      lun,
2076 			      retries,
2077 			      retry_time_ms);
2078 }
2079 EXPORT_SYMBOL(ipmi_request_settime);
2080 
2081 int ipmi_request_supply_msgs(ipmi_user_t          user,
2082 			     struct ipmi_addr     *addr,
2083 			     long                 msgid,
2084 			     struct kernel_ipmi_msg *msg,
2085 			     void                 *user_msg_data,
2086 			     void                 *supplied_smi,
2087 			     struct ipmi_recv_msg *supplied_recv,
2088 			     int                  priority)
2089 {
2090 	unsigned char saddr = 0, lun = 0;
2091 	int           rv;
2092 
2093 	if (!user)
2094 		return -EINVAL;
2095 	rv = check_addr(user->intf, addr, &saddr, &lun);
2096 	if (rv)
2097 		return rv;
2098 	return i_ipmi_request(user,
2099 			      user->intf,
2100 			      addr,
2101 			      msgid,
2102 			      msg,
2103 			      user_msg_data,
2104 			      supplied_smi,
2105 			      supplied_recv,
2106 			      priority,
2107 			      saddr,
2108 			      lun,
2109 			      -1, 0);
2110 }
2111 EXPORT_SYMBOL(ipmi_request_supply_msgs);
2112 
2113 static void bmc_device_id_handler(ipmi_smi_t intf, struct ipmi_recv_msg *msg)
2114 {
2115 	int rv;
2116 
2117 	if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
2118 			|| (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE)
2119 			|| (msg->msg.cmd != IPMI_GET_DEVICE_ID_CMD)) {
2120 		dev_warn(intf->si_dev,
2121 			 PFX "invalid device_id msg: addr_type=%d netfn=%x cmd=%x\n",
2122 			msg->addr.addr_type, msg->msg.netfn, msg->msg.cmd);
2123 		return;
2124 	}
2125 
2126 	rv = ipmi_demangle_device_id(msg->msg.netfn, msg->msg.cmd,
2127 			msg->msg.data, msg->msg.data_len, &intf->bmc->fetch_id);
2128 	if (rv) {
2129 		dev_warn(intf->si_dev,
2130 			 PFX "device id demangle failed: %d\n", rv);
2131 		intf->bmc->dyn_id_set = 0;
2132 	} else {
2133 		/*
2134 		 * Make sure the id data is available before setting
2135 		 * dyn_id_set.
2136 		 */
2137 		smp_wmb();
2138 		intf->bmc->dyn_id_set = 1;
2139 	}
2140 
2141 	wake_up(&intf->waitq);
2142 }
2143 
2144 static int
2145 send_get_device_id_cmd(ipmi_smi_t intf)
2146 {
2147 	struct ipmi_system_interface_addr si;
2148 	struct kernel_ipmi_msg msg;
2149 
2150 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
2151 	si.channel = IPMI_BMC_CHANNEL;
2152 	si.lun = 0;
2153 
2154 	msg.netfn = IPMI_NETFN_APP_REQUEST;
2155 	msg.cmd = IPMI_GET_DEVICE_ID_CMD;
2156 	msg.data = NULL;
2157 	msg.data_len = 0;
2158 
2159 	return i_ipmi_request(NULL,
2160 			      intf,
2161 			      (struct ipmi_addr *) &si,
2162 			      0,
2163 			      &msg,
2164 			      intf,
2165 			      NULL,
2166 			      NULL,
2167 			      0,
2168 			      intf->addrinfo[0].address,
2169 			      intf->addrinfo[0].lun,
2170 			      -1, 0);
2171 }
2172 
2173 static int __get_device_id(ipmi_smi_t intf, struct bmc_device *bmc)
2174 {
2175 	int rv;
2176 
2177 	bmc->dyn_id_set = 2;
2178 
2179 	intf->null_user_handler = bmc_device_id_handler;
2180 
2181 	rv = send_get_device_id_cmd(intf);
2182 	if (rv)
2183 		return rv;
2184 
2185 	wait_event(intf->waitq, bmc->dyn_id_set != 2);
2186 
2187 	if (!bmc->dyn_id_set)
2188 		rv = -EIO; /* Something went wrong in the fetch. */
2189 
2190 	/* dyn_id_set makes the id data available. */
2191 	smp_rmb();
2192 
2193 	intf->null_user_handler = NULL;
2194 
2195 	return rv;
2196 }
2197 
2198 /*
2199  * Fetch the device id for the bmc/interface.  You must pass in either
2200  * bmc or intf, this code will get the other one.  If the data has
2201  * been recently fetched, this will just use the cached data.  Otherwise
2202  * it will run a new fetch.
2203  *
2204  * Except for the first time this is called (in ipmi_register_smi()),
2205  * this will always return good data;
2206  */
2207 static int __bmc_get_device_id(ipmi_smi_t intf, struct bmc_device *bmc,
2208 			       struct ipmi_device_id *id,
2209 			       bool *guid_set, guid_t *guid, int intf_num)
2210 {
2211 	int rv = 0;
2212 	int prev_dyn_id_set, prev_guid_set;
2213 	bool intf_set = intf != NULL;
2214 
2215 	if (!intf) {
2216 		mutex_lock(&bmc->dyn_mutex);
2217 retry_bmc_lock:
2218 		if (list_empty(&bmc->intfs)) {
2219 			mutex_unlock(&bmc->dyn_mutex);
2220 			return -ENOENT;
2221 		}
2222 		intf = list_first_entry(&bmc->intfs, struct ipmi_smi,
2223 					bmc_link);
2224 		kref_get(&intf->refcount);
2225 		mutex_unlock(&bmc->dyn_mutex);
2226 		mutex_lock(&intf->bmc_reg_mutex);
2227 		mutex_lock(&bmc->dyn_mutex);
2228 		if (intf != list_first_entry(&bmc->intfs, struct ipmi_smi,
2229 					     bmc_link)) {
2230 			mutex_unlock(&intf->bmc_reg_mutex);
2231 			kref_put(&intf->refcount, intf_free);
2232 			goto retry_bmc_lock;
2233 		}
2234 	} else {
2235 		mutex_lock(&intf->bmc_reg_mutex);
2236 		bmc = intf->bmc;
2237 		mutex_lock(&bmc->dyn_mutex);
2238 		kref_get(&intf->refcount);
2239 	}
2240 
2241 	/* If we have a valid and current ID, just return that. */
2242 	if (intf->in_bmc_register ||
2243 	    (bmc->dyn_id_set && time_is_after_jiffies(bmc->dyn_id_expiry)))
2244 		goto out_noprocessing;
2245 
2246 	prev_guid_set = bmc->dyn_guid_set;
2247 	__get_guid(intf);
2248 
2249 	prev_dyn_id_set = bmc->dyn_id_set;
2250 	rv = __get_device_id(intf, bmc);
2251 	if (rv)
2252 		goto out;
2253 
2254 	/*
2255 	 * The guid, device id, manufacturer id, and product id should
2256 	 * not change on a BMC.  If it does we have to do some dancing.
2257 	 */
2258 	if (!intf->bmc_registered
2259 	    || (!prev_guid_set && bmc->dyn_guid_set)
2260 	    || (!prev_dyn_id_set && bmc->dyn_id_set)
2261 	    || (prev_guid_set && bmc->dyn_guid_set
2262 		&& !guid_equal(&bmc->guid, &bmc->fetch_guid))
2263 	    || bmc->id.device_id != bmc->fetch_id.device_id
2264 	    || bmc->id.manufacturer_id != bmc->fetch_id.manufacturer_id
2265 	    || bmc->id.product_id != bmc->fetch_id.product_id) {
2266 		struct ipmi_device_id id = bmc->fetch_id;
2267 		int guid_set = bmc->dyn_guid_set;
2268 		guid_t guid;
2269 
2270 		guid = bmc->fetch_guid;
2271 		mutex_unlock(&bmc->dyn_mutex);
2272 
2273 		__ipmi_bmc_unregister(intf);
2274 		/* Fill in the temporary BMC for good measure. */
2275 		intf->bmc->id = id;
2276 		intf->bmc->dyn_guid_set = guid_set;
2277 		intf->bmc->guid = guid;
2278 		if (__ipmi_bmc_register(intf, &id, guid_set, &guid, intf_num))
2279 			need_waiter(intf); /* Retry later on an error. */
2280 		else
2281 			__scan_channels(intf, &id);
2282 
2283 
2284 		if (!intf_set) {
2285 			/*
2286 			 * We weren't given the interface on the
2287 			 * command line, so restart the operation on
2288 			 * the next interface for the BMC.
2289 			 */
2290 			mutex_unlock(&intf->bmc_reg_mutex);
2291 			mutex_lock(&bmc->dyn_mutex);
2292 			goto retry_bmc_lock;
2293 		}
2294 
2295 		/* We have a new BMC, set it up. */
2296 		bmc = intf->bmc;
2297 		mutex_lock(&bmc->dyn_mutex);
2298 		goto out_noprocessing;
2299 	} else if (memcmp(&bmc->fetch_id, &bmc->id, sizeof(bmc->id)))
2300 		/* Version info changes, scan the channels again. */
2301 		__scan_channels(intf, &bmc->fetch_id);
2302 
2303 	bmc->dyn_id_expiry = jiffies + IPMI_DYN_DEV_ID_EXPIRY;
2304 
2305 out:
2306 	if (rv && prev_dyn_id_set) {
2307 		rv = 0; /* Ignore failures if we have previous data. */
2308 		bmc->dyn_id_set = prev_dyn_id_set;
2309 	}
2310 	if (!rv) {
2311 		bmc->id = bmc->fetch_id;
2312 		if (bmc->dyn_guid_set)
2313 			bmc->guid = bmc->fetch_guid;
2314 		else if (prev_guid_set)
2315 			/*
2316 			 * The guid used to be valid and it failed to fetch,
2317 			 * just use the cached value.
2318 			 */
2319 			bmc->dyn_guid_set = prev_guid_set;
2320 	}
2321 out_noprocessing:
2322 	if (!rv) {
2323 		if (id)
2324 			*id = bmc->id;
2325 
2326 		if (guid_set)
2327 			*guid_set = bmc->dyn_guid_set;
2328 
2329 		if (guid && bmc->dyn_guid_set)
2330 			*guid =  bmc->guid;
2331 	}
2332 
2333 	mutex_unlock(&bmc->dyn_mutex);
2334 	mutex_unlock(&intf->bmc_reg_mutex);
2335 
2336 	kref_put(&intf->refcount, intf_free);
2337 	return rv;
2338 }
2339 
2340 static int bmc_get_device_id(ipmi_smi_t intf, struct bmc_device *bmc,
2341 			     struct ipmi_device_id *id,
2342 			     bool *guid_set, guid_t *guid)
2343 {
2344 	return __bmc_get_device_id(intf, bmc, id, guid_set, guid, -1);
2345 }
2346 
2347 #ifdef CONFIG_IPMI_PROC_INTERFACE
2348 static int smi_ipmb_proc_show(struct seq_file *m, void *v)
2349 {
2350 	ipmi_smi_t intf = m->private;
2351 	int        i;
2352 
2353 	seq_printf(m, "%x", intf->addrinfo[0].address);
2354 	for (i = 1; i < IPMI_MAX_CHANNELS; i++)
2355 		seq_printf(m, " %x", intf->addrinfo[i].address);
2356 	seq_putc(m, '\n');
2357 
2358 	return 0;
2359 }
2360 
2361 static int smi_ipmb_proc_open(struct inode *inode, struct file *file)
2362 {
2363 	return single_open(file, smi_ipmb_proc_show, PDE_DATA(inode));
2364 }
2365 
2366 static const struct file_operations smi_ipmb_proc_ops = {
2367 	.open		= smi_ipmb_proc_open,
2368 	.read		= seq_read,
2369 	.llseek		= seq_lseek,
2370 	.release	= single_release,
2371 };
2372 
2373 static int smi_version_proc_show(struct seq_file *m, void *v)
2374 {
2375 	ipmi_smi_t intf = m->private;
2376 	struct ipmi_device_id id;
2377 	int rv;
2378 
2379 	rv = bmc_get_device_id(intf, NULL, &id, NULL, NULL);
2380 	if (rv)
2381 		return rv;
2382 
2383 	seq_printf(m, "%u.%u\n",
2384 		   ipmi_version_major(&id),
2385 		   ipmi_version_minor(&id));
2386 
2387 	return 0;
2388 }
2389 
2390 static int smi_version_proc_open(struct inode *inode, struct file *file)
2391 {
2392 	return single_open(file, smi_version_proc_show, PDE_DATA(inode));
2393 }
2394 
2395 static const struct file_operations smi_version_proc_ops = {
2396 	.open		= smi_version_proc_open,
2397 	.read		= seq_read,
2398 	.llseek		= seq_lseek,
2399 	.release	= single_release,
2400 };
2401 
2402 static int smi_stats_proc_show(struct seq_file *m, void *v)
2403 {
2404 	ipmi_smi_t intf = m->private;
2405 
2406 	seq_printf(m, "sent_invalid_commands:       %u\n",
2407 		       ipmi_get_stat(intf, sent_invalid_commands));
2408 	seq_printf(m, "sent_local_commands:         %u\n",
2409 		       ipmi_get_stat(intf, sent_local_commands));
2410 	seq_printf(m, "handled_local_responses:     %u\n",
2411 		       ipmi_get_stat(intf, handled_local_responses));
2412 	seq_printf(m, "unhandled_local_responses:   %u\n",
2413 		       ipmi_get_stat(intf, unhandled_local_responses));
2414 	seq_printf(m, "sent_ipmb_commands:          %u\n",
2415 		       ipmi_get_stat(intf, sent_ipmb_commands));
2416 	seq_printf(m, "sent_ipmb_command_errs:      %u\n",
2417 		       ipmi_get_stat(intf, sent_ipmb_command_errs));
2418 	seq_printf(m, "retransmitted_ipmb_commands: %u\n",
2419 		       ipmi_get_stat(intf, retransmitted_ipmb_commands));
2420 	seq_printf(m, "timed_out_ipmb_commands:     %u\n",
2421 		       ipmi_get_stat(intf, timed_out_ipmb_commands));
2422 	seq_printf(m, "timed_out_ipmb_broadcasts:   %u\n",
2423 		       ipmi_get_stat(intf, timed_out_ipmb_broadcasts));
2424 	seq_printf(m, "sent_ipmb_responses:         %u\n",
2425 		       ipmi_get_stat(intf, sent_ipmb_responses));
2426 	seq_printf(m, "handled_ipmb_responses:      %u\n",
2427 		       ipmi_get_stat(intf, handled_ipmb_responses));
2428 	seq_printf(m, "invalid_ipmb_responses:      %u\n",
2429 		       ipmi_get_stat(intf, invalid_ipmb_responses));
2430 	seq_printf(m, "unhandled_ipmb_responses:    %u\n",
2431 		       ipmi_get_stat(intf, unhandled_ipmb_responses));
2432 	seq_printf(m, "sent_lan_commands:           %u\n",
2433 		       ipmi_get_stat(intf, sent_lan_commands));
2434 	seq_printf(m, "sent_lan_command_errs:       %u\n",
2435 		       ipmi_get_stat(intf, sent_lan_command_errs));
2436 	seq_printf(m, "retransmitted_lan_commands:  %u\n",
2437 		       ipmi_get_stat(intf, retransmitted_lan_commands));
2438 	seq_printf(m, "timed_out_lan_commands:      %u\n",
2439 		       ipmi_get_stat(intf, timed_out_lan_commands));
2440 	seq_printf(m, "sent_lan_responses:          %u\n",
2441 		       ipmi_get_stat(intf, sent_lan_responses));
2442 	seq_printf(m, "handled_lan_responses:       %u\n",
2443 		       ipmi_get_stat(intf, handled_lan_responses));
2444 	seq_printf(m, "invalid_lan_responses:       %u\n",
2445 		       ipmi_get_stat(intf, invalid_lan_responses));
2446 	seq_printf(m, "unhandled_lan_responses:     %u\n",
2447 		       ipmi_get_stat(intf, unhandled_lan_responses));
2448 	seq_printf(m, "handled_commands:            %u\n",
2449 		       ipmi_get_stat(intf, handled_commands));
2450 	seq_printf(m, "invalid_commands:            %u\n",
2451 		       ipmi_get_stat(intf, invalid_commands));
2452 	seq_printf(m, "unhandled_commands:          %u\n",
2453 		       ipmi_get_stat(intf, unhandled_commands));
2454 	seq_printf(m, "invalid_events:              %u\n",
2455 		       ipmi_get_stat(intf, invalid_events));
2456 	seq_printf(m, "events:                      %u\n",
2457 		       ipmi_get_stat(intf, events));
2458 	seq_printf(m, "failed rexmit LAN msgs:      %u\n",
2459 		       ipmi_get_stat(intf, dropped_rexmit_lan_commands));
2460 	seq_printf(m, "failed rexmit IPMB msgs:     %u\n",
2461 		       ipmi_get_stat(intf, dropped_rexmit_ipmb_commands));
2462 	return 0;
2463 }
2464 
2465 static int smi_stats_proc_open(struct inode *inode, struct file *file)
2466 {
2467 	return single_open(file, smi_stats_proc_show, PDE_DATA(inode));
2468 }
2469 
2470 static const struct file_operations smi_stats_proc_ops = {
2471 	.open		= smi_stats_proc_open,
2472 	.read		= seq_read,
2473 	.llseek		= seq_lseek,
2474 	.release	= single_release,
2475 };
2476 
2477 int ipmi_smi_add_proc_entry(ipmi_smi_t smi, char *name,
2478 			    const struct file_operations *proc_ops,
2479 			    void *data)
2480 {
2481 	int                    rv = 0;
2482 	struct proc_dir_entry  *file;
2483 	struct ipmi_proc_entry *entry;
2484 
2485 	/* Create a list element. */
2486 	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
2487 	if (!entry)
2488 		return -ENOMEM;
2489 	entry->name = kstrdup(name, GFP_KERNEL);
2490 	if (!entry->name) {
2491 		kfree(entry);
2492 		return -ENOMEM;
2493 	}
2494 
2495 	file = proc_create_data(name, 0, smi->proc_dir, proc_ops, data);
2496 	if (!file) {
2497 		kfree(entry->name);
2498 		kfree(entry);
2499 		rv = -ENOMEM;
2500 	} else {
2501 		mutex_lock(&smi->proc_entry_lock);
2502 		/* Stick it on the list. */
2503 		entry->next = smi->proc_entries;
2504 		smi->proc_entries = entry;
2505 		mutex_unlock(&smi->proc_entry_lock);
2506 	}
2507 
2508 	return rv;
2509 }
2510 EXPORT_SYMBOL(ipmi_smi_add_proc_entry);
2511 
2512 static int add_proc_entries(ipmi_smi_t smi, int num)
2513 {
2514 	int rv = 0;
2515 
2516 	sprintf(smi->proc_dir_name, "%d", num);
2517 	smi->proc_dir = proc_mkdir(smi->proc_dir_name, proc_ipmi_root);
2518 	if (!smi->proc_dir)
2519 		rv = -ENOMEM;
2520 
2521 	if (rv == 0)
2522 		rv = ipmi_smi_add_proc_entry(smi, "stats",
2523 					     &smi_stats_proc_ops,
2524 					     smi);
2525 
2526 	if (rv == 0)
2527 		rv = ipmi_smi_add_proc_entry(smi, "ipmb",
2528 					     &smi_ipmb_proc_ops,
2529 					     smi);
2530 
2531 	if (rv == 0)
2532 		rv = ipmi_smi_add_proc_entry(smi, "version",
2533 					     &smi_version_proc_ops,
2534 					     smi);
2535 
2536 	return rv;
2537 }
2538 
2539 static void remove_proc_entries(ipmi_smi_t smi)
2540 {
2541 	struct ipmi_proc_entry *entry;
2542 
2543 	mutex_lock(&smi->proc_entry_lock);
2544 	while (smi->proc_entries) {
2545 		entry = smi->proc_entries;
2546 		smi->proc_entries = entry->next;
2547 
2548 		remove_proc_entry(entry->name, smi->proc_dir);
2549 		kfree(entry->name);
2550 		kfree(entry);
2551 	}
2552 	mutex_unlock(&smi->proc_entry_lock);
2553 	remove_proc_entry(smi->proc_dir_name, proc_ipmi_root);
2554 }
2555 #endif /* CONFIG_IPMI_PROC_INTERFACE */
2556 
2557 static ssize_t device_id_show(struct device *dev,
2558 			      struct device_attribute *attr,
2559 			      char *buf)
2560 {
2561 	struct bmc_device *bmc = to_bmc_device(dev);
2562 	struct ipmi_device_id id;
2563 	int rv;
2564 
2565 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2566 	if (rv)
2567 		return rv;
2568 
2569 	return snprintf(buf, 10, "%u\n", id.device_id);
2570 }
2571 static DEVICE_ATTR_RO(device_id);
2572 
2573 static ssize_t provides_device_sdrs_show(struct device *dev,
2574 					 struct device_attribute *attr,
2575 					 char *buf)
2576 {
2577 	struct bmc_device *bmc = to_bmc_device(dev);
2578 	struct ipmi_device_id id;
2579 	int rv;
2580 
2581 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2582 	if (rv)
2583 		return rv;
2584 
2585 	return snprintf(buf, 10, "%u\n", (id.device_revision & 0x80) >> 7);
2586 }
2587 static DEVICE_ATTR_RO(provides_device_sdrs);
2588 
2589 static ssize_t revision_show(struct device *dev, struct device_attribute *attr,
2590 			     char *buf)
2591 {
2592 	struct bmc_device *bmc = to_bmc_device(dev);
2593 	struct ipmi_device_id id;
2594 	int rv;
2595 
2596 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2597 	if (rv)
2598 		return rv;
2599 
2600 	return snprintf(buf, 20, "%u\n", id.device_revision & 0x0F);
2601 }
2602 static DEVICE_ATTR_RO(revision);
2603 
2604 static ssize_t firmware_revision_show(struct device *dev,
2605 				      struct device_attribute *attr,
2606 				      char *buf)
2607 {
2608 	struct bmc_device *bmc = to_bmc_device(dev);
2609 	struct ipmi_device_id id;
2610 	int rv;
2611 
2612 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2613 	if (rv)
2614 		return rv;
2615 
2616 	return snprintf(buf, 20, "%u.%x\n", id.firmware_revision_1,
2617 			id.firmware_revision_2);
2618 }
2619 static DEVICE_ATTR_RO(firmware_revision);
2620 
2621 static ssize_t ipmi_version_show(struct device *dev,
2622 				 struct device_attribute *attr,
2623 				 char *buf)
2624 {
2625 	struct bmc_device *bmc = to_bmc_device(dev);
2626 	struct ipmi_device_id id;
2627 	int rv;
2628 
2629 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2630 	if (rv)
2631 		return rv;
2632 
2633 	return snprintf(buf, 20, "%u.%u\n",
2634 			ipmi_version_major(&id),
2635 			ipmi_version_minor(&id));
2636 }
2637 static DEVICE_ATTR_RO(ipmi_version);
2638 
2639 static ssize_t add_dev_support_show(struct device *dev,
2640 				    struct device_attribute *attr,
2641 				    char *buf)
2642 {
2643 	struct bmc_device *bmc = to_bmc_device(dev);
2644 	struct ipmi_device_id id;
2645 	int rv;
2646 
2647 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2648 	if (rv)
2649 		return rv;
2650 
2651 	return snprintf(buf, 10, "0x%02x\n", id.additional_device_support);
2652 }
2653 static DEVICE_ATTR(additional_device_support, S_IRUGO, add_dev_support_show,
2654 		   NULL);
2655 
2656 static ssize_t manufacturer_id_show(struct device *dev,
2657 				    struct device_attribute *attr,
2658 				    char *buf)
2659 {
2660 	struct bmc_device *bmc = to_bmc_device(dev);
2661 	struct ipmi_device_id id;
2662 	int rv;
2663 
2664 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2665 	if (rv)
2666 		return rv;
2667 
2668 	return snprintf(buf, 20, "0x%6.6x\n", id.manufacturer_id);
2669 }
2670 static DEVICE_ATTR_RO(manufacturer_id);
2671 
2672 static ssize_t product_id_show(struct device *dev,
2673 			       struct device_attribute *attr,
2674 			       char *buf)
2675 {
2676 	struct bmc_device *bmc = to_bmc_device(dev);
2677 	struct ipmi_device_id id;
2678 	int rv;
2679 
2680 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2681 	if (rv)
2682 		return rv;
2683 
2684 	return snprintf(buf, 10, "0x%4.4x\n", id.product_id);
2685 }
2686 static DEVICE_ATTR_RO(product_id);
2687 
2688 static ssize_t aux_firmware_rev_show(struct device *dev,
2689 				     struct device_attribute *attr,
2690 				     char *buf)
2691 {
2692 	struct bmc_device *bmc = to_bmc_device(dev);
2693 	struct ipmi_device_id id;
2694 	int rv;
2695 
2696 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2697 	if (rv)
2698 		return rv;
2699 
2700 	return snprintf(buf, 21, "0x%02x 0x%02x 0x%02x 0x%02x\n",
2701 			id.aux_firmware_revision[3],
2702 			id.aux_firmware_revision[2],
2703 			id.aux_firmware_revision[1],
2704 			id.aux_firmware_revision[0]);
2705 }
2706 static DEVICE_ATTR(aux_firmware_revision, S_IRUGO, aux_firmware_rev_show, NULL);
2707 
2708 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
2709 			 char *buf)
2710 {
2711 	struct bmc_device *bmc = to_bmc_device(dev);
2712 	bool guid_set;
2713 	guid_t guid;
2714 	int rv;
2715 
2716 	rv = bmc_get_device_id(NULL, bmc, NULL, &guid_set, &guid);
2717 	if (rv)
2718 		return rv;
2719 	if (!guid_set)
2720 		return -ENOENT;
2721 
2722 	return snprintf(buf, 38, "%pUl\n", guid.b);
2723 }
2724 static DEVICE_ATTR_RO(guid);
2725 
2726 static struct attribute *bmc_dev_attrs[] = {
2727 	&dev_attr_device_id.attr,
2728 	&dev_attr_provides_device_sdrs.attr,
2729 	&dev_attr_revision.attr,
2730 	&dev_attr_firmware_revision.attr,
2731 	&dev_attr_ipmi_version.attr,
2732 	&dev_attr_additional_device_support.attr,
2733 	&dev_attr_manufacturer_id.attr,
2734 	&dev_attr_product_id.attr,
2735 	&dev_attr_aux_firmware_revision.attr,
2736 	&dev_attr_guid.attr,
2737 	NULL
2738 };
2739 
2740 static umode_t bmc_dev_attr_is_visible(struct kobject *kobj,
2741 				       struct attribute *attr, int idx)
2742 {
2743 	struct device *dev = kobj_to_dev(kobj);
2744 	struct bmc_device *bmc = to_bmc_device(dev);
2745 	umode_t mode = attr->mode;
2746 	int rv;
2747 
2748 	if (attr == &dev_attr_aux_firmware_revision.attr) {
2749 		struct ipmi_device_id id;
2750 
2751 		rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2752 		return (!rv && id.aux_firmware_revision_set) ? mode : 0;
2753 	}
2754 	if (attr == &dev_attr_guid.attr) {
2755 		bool guid_set;
2756 
2757 		rv = bmc_get_device_id(NULL, bmc, NULL, &guid_set, NULL);
2758 		return (!rv && guid_set) ? mode : 0;
2759 	}
2760 	return mode;
2761 }
2762 
2763 static const struct attribute_group bmc_dev_attr_group = {
2764 	.attrs		= bmc_dev_attrs,
2765 	.is_visible	= bmc_dev_attr_is_visible,
2766 };
2767 
2768 static const struct attribute_group *bmc_dev_attr_groups[] = {
2769 	&bmc_dev_attr_group,
2770 	NULL
2771 };
2772 
2773 static const struct device_type bmc_device_type = {
2774 	.groups		= bmc_dev_attr_groups,
2775 };
2776 
2777 static int __find_bmc_guid(struct device *dev, void *data)
2778 {
2779 	guid_t *guid = data;
2780 	struct bmc_device *bmc;
2781 	int rv;
2782 
2783 	if (dev->type != &bmc_device_type)
2784 		return 0;
2785 
2786 	bmc = to_bmc_device(dev);
2787 	rv = bmc->dyn_guid_set && guid_equal(&bmc->guid, guid);
2788 	if (rv)
2789 		rv = kref_get_unless_zero(&bmc->usecount);
2790 	return rv;
2791 }
2792 
2793 /*
2794  * Returns with the bmc's usecount incremented, if it is non-NULL.
2795  */
2796 static struct bmc_device *ipmi_find_bmc_guid(struct device_driver *drv,
2797 					     guid_t *guid)
2798 {
2799 	struct device *dev;
2800 	struct bmc_device *bmc = NULL;
2801 
2802 	dev = driver_find_device(drv, NULL, guid, __find_bmc_guid);
2803 	if (dev) {
2804 		bmc = to_bmc_device(dev);
2805 		put_device(dev);
2806 	}
2807 	return bmc;
2808 }
2809 
2810 struct prod_dev_id {
2811 	unsigned int  product_id;
2812 	unsigned char device_id;
2813 };
2814 
2815 static int __find_bmc_prod_dev_id(struct device *dev, void *data)
2816 {
2817 	struct prod_dev_id *cid = data;
2818 	struct bmc_device *bmc;
2819 	int rv;
2820 
2821 	if (dev->type != &bmc_device_type)
2822 		return 0;
2823 
2824 	bmc = to_bmc_device(dev);
2825 	rv = (bmc->id.product_id == cid->product_id
2826 	      && bmc->id.device_id == cid->device_id);
2827 	if (rv)
2828 		rv = kref_get_unless_zero(&bmc->usecount);
2829 	return rv;
2830 }
2831 
2832 /*
2833  * Returns with the bmc's usecount incremented, if it is non-NULL.
2834  */
2835 static struct bmc_device *ipmi_find_bmc_prod_dev_id(
2836 	struct device_driver *drv,
2837 	unsigned int product_id, unsigned char device_id)
2838 {
2839 	struct prod_dev_id id = {
2840 		.product_id = product_id,
2841 		.device_id = device_id,
2842 	};
2843 	struct device *dev;
2844 	struct bmc_device *bmc = NULL;
2845 
2846 	dev = driver_find_device(drv, NULL, &id, __find_bmc_prod_dev_id);
2847 	if (dev) {
2848 		bmc = to_bmc_device(dev);
2849 		put_device(dev);
2850 	}
2851 	return bmc;
2852 }
2853 
2854 static DEFINE_IDA(ipmi_bmc_ida);
2855 
2856 static void
2857 release_bmc_device(struct device *dev)
2858 {
2859 	kfree(to_bmc_device(dev));
2860 }
2861 
2862 static void cleanup_bmc_work(struct work_struct *work)
2863 {
2864 	struct bmc_device *bmc = container_of(work, struct bmc_device,
2865 					      remove_work);
2866 	int id = bmc->pdev.id; /* Unregister overwrites id */
2867 
2868 	platform_device_unregister(&bmc->pdev);
2869 	ida_simple_remove(&ipmi_bmc_ida, id);
2870 }
2871 
2872 static void
2873 cleanup_bmc_device(struct kref *ref)
2874 {
2875 	struct bmc_device *bmc = container_of(ref, struct bmc_device, usecount);
2876 
2877 	/*
2878 	 * Remove the platform device in a work queue to avoid issues
2879 	 * with removing the device attributes while reading a device
2880 	 * attribute.
2881 	 */
2882 	schedule_work(&bmc->remove_work);
2883 }
2884 
2885 /*
2886  * Must be called with intf->bmc_reg_mutex held.
2887  */
2888 static void __ipmi_bmc_unregister(ipmi_smi_t intf)
2889 {
2890 	struct bmc_device *bmc = intf->bmc;
2891 
2892 	if (!intf->bmc_registered)
2893 		return;
2894 
2895 	sysfs_remove_link(&intf->si_dev->kobj, "bmc");
2896 	sysfs_remove_link(&bmc->pdev.dev.kobj, intf->my_dev_name);
2897 	kfree(intf->my_dev_name);
2898 	intf->my_dev_name = NULL;
2899 
2900 	mutex_lock(&bmc->dyn_mutex);
2901 	list_del(&intf->bmc_link);
2902 	mutex_unlock(&bmc->dyn_mutex);
2903 	intf->bmc = &intf->tmp_bmc;
2904 	kref_put(&bmc->usecount, cleanup_bmc_device);
2905 	intf->bmc_registered = false;
2906 }
2907 
2908 static void ipmi_bmc_unregister(ipmi_smi_t intf)
2909 {
2910 	mutex_lock(&intf->bmc_reg_mutex);
2911 	__ipmi_bmc_unregister(intf);
2912 	mutex_unlock(&intf->bmc_reg_mutex);
2913 }
2914 
2915 /*
2916  * Must be called with intf->bmc_reg_mutex held.
2917  */
2918 static int __ipmi_bmc_register(ipmi_smi_t intf,
2919 			       struct ipmi_device_id *id,
2920 			       bool guid_set, guid_t *guid, int intf_num)
2921 {
2922 	int               rv;
2923 	struct bmc_device *bmc;
2924 	struct bmc_device *old_bmc;
2925 
2926 	/*
2927 	 * platform_device_register() can cause bmc_reg_mutex to
2928 	 * be claimed because of the is_visible functions of
2929 	 * the attributes.  Eliminate possible recursion and
2930 	 * release the lock.
2931 	 */
2932 	intf->in_bmc_register = true;
2933 	mutex_unlock(&intf->bmc_reg_mutex);
2934 
2935 	/*
2936 	 * Try to find if there is an bmc_device struct
2937 	 * representing the interfaced BMC already
2938 	 */
2939 	mutex_lock(&ipmidriver_mutex);
2940 	if (guid_set)
2941 		old_bmc = ipmi_find_bmc_guid(&ipmidriver.driver, guid);
2942 	else
2943 		old_bmc = ipmi_find_bmc_prod_dev_id(&ipmidriver.driver,
2944 						    id->product_id,
2945 						    id->device_id);
2946 
2947 	/*
2948 	 * If there is already an bmc_device, free the new one,
2949 	 * otherwise register the new BMC device
2950 	 */
2951 	if (old_bmc) {
2952 		bmc = old_bmc;
2953 		/*
2954 		 * Note: old_bmc already has usecount incremented by
2955 		 * the BMC find functions.
2956 		 */
2957 		intf->bmc = old_bmc;
2958 		mutex_lock(&bmc->dyn_mutex);
2959 		list_add_tail(&intf->bmc_link, &bmc->intfs);
2960 		mutex_unlock(&bmc->dyn_mutex);
2961 
2962 		dev_info(intf->si_dev,
2963 			 "ipmi: interfacing existing BMC (man_id: 0x%6.6x,"
2964 			 " prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n",
2965 			 bmc->id.manufacturer_id,
2966 			 bmc->id.product_id,
2967 			 bmc->id.device_id);
2968 	} else {
2969 		bmc = kzalloc(sizeof(*bmc), GFP_KERNEL);
2970 		if (!bmc) {
2971 			rv = -ENOMEM;
2972 			goto out;
2973 		}
2974 		INIT_LIST_HEAD(&bmc->intfs);
2975 		mutex_init(&bmc->dyn_mutex);
2976 		INIT_WORK(&bmc->remove_work, cleanup_bmc_work);
2977 
2978 		bmc->id = *id;
2979 		bmc->dyn_id_set = 1;
2980 		bmc->dyn_guid_set = guid_set;
2981 		bmc->guid = *guid;
2982 		bmc->dyn_id_expiry = jiffies + IPMI_DYN_DEV_ID_EXPIRY;
2983 
2984 		bmc->pdev.name = "ipmi_bmc";
2985 
2986 		rv = ida_simple_get(&ipmi_bmc_ida, 0, 0, GFP_KERNEL);
2987 		if (rv < 0)
2988 			goto out;
2989 		bmc->pdev.dev.driver = &ipmidriver.driver;
2990 		bmc->pdev.id = rv;
2991 		bmc->pdev.dev.release = release_bmc_device;
2992 		bmc->pdev.dev.type = &bmc_device_type;
2993 		kref_init(&bmc->usecount);
2994 
2995 		intf->bmc = bmc;
2996 		mutex_lock(&bmc->dyn_mutex);
2997 		list_add_tail(&intf->bmc_link, &bmc->intfs);
2998 		mutex_unlock(&bmc->dyn_mutex);
2999 
3000 		rv = platform_device_register(&bmc->pdev);
3001 		if (rv) {
3002 			dev_err(intf->si_dev,
3003 				PFX " Unable to register bmc device: %d\n",
3004 				rv);
3005 			goto out_list_del;
3006 		}
3007 
3008 		dev_info(intf->si_dev,
3009 			 "Found new BMC (man_id: 0x%6.6x, prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n",
3010 			 bmc->id.manufacturer_id,
3011 			 bmc->id.product_id,
3012 			 bmc->id.device_id);
3013 	}
3014 
3015 	/*
3016 	 * create symlink from system interface device to bmc device
3017 	 * and back.
3018 	 */
3019 	rv = sysfs_create_link(&intf->si_dev->kobj, &bmc->pdev.dev.kobj, "bmc");
3020 	if (rv) {
3021 		dev_err(intf->si_dev,
3022 			PFX "Unable to create bmc symlink: %d\n", rv);
3023 		goto out_put_bmc;
3024 	}
3025 
3026 	if (intf_num == -1)
3027 		intf_num = intf->intf_num;
3028 	intf->my_dev_name = kasprintf(GFP_KERNEL, "ipmi%d", intf_num);
3029 	if (!intf->my_dev_name) {
3030 		rv = -ENOMEM;
3031 		dev_err(intf->si_dev,
3032 			PFX "Unable to allocate link from BMC: %d\n", rv);
3033 		goto out_unlink1;
3034 	}
3035 
3036 	rv = sysfs_create_link(&bmc->pdev.dev.kobj, &intf->si_dev->kobj,
3037 			       intf->my_dev_name);
3038 	if (rv) {
3039 		kfree(intf->my_dev_name);
3040 		intf->my_dev_name = NULL;
3041 		dev_err(intf->si_dev,
3042 			PFX "Unable to create symlink to bmc: %d\n", rv);
3043 		goto out_free_my_dev_name;
3044 	}
3045 
3046 	intf->bmc_registered = true;
3047 
3048 out:
3049 	mutex_unlock(&ipmidriver_mutex);
3050 	mutex_lock(&intf->bmc_reg_mutex);
3051 	intf->in_bmc_register = false;
3052 	return rv;
3053 
3054 
3055 out_free_my_dev_name:
3056 	kfree(intf->my_dev_name);
3057 	intf->my_dev_name = NULL;
3058 
3059 out_unlink1:
3060 	sysfs_remove_link(&intf->si_dev->kobj, "bmc");
3061 
3062 out_put_bmc:
3063 	mutex_lock(&bmc->dyn_mutex);
3064 	list_del(&intf->bmc_link);
3065 	mutex_unlock(&bmc->dyn_mutex);
3066 	intf->bmc = &intf->tmp_bmc;
3067 	kref_put(&bmc->usecount, cleanup_bmc_device);
3068 	goto out;
3069 
3070 out_list_del:
3071 	mutex_lock(&bmc->dyn_mutex);
3072 	list_del(&intf->bmc_link);
3073 	mutex_unlock(&bmc->dyn_mutex);
3074 	intf->bmc = &intf->tmp_bmc;
3075 	put_device(&bmc->pdev.dev);
3076 	goto out;
3077 }
3078 
3079 static int
3080 send_guid_cmd(ipmi_smi_t intf, int chan)
3081 {
3082 	struct kernel_ipmi_msg            msg;
3083 	struct ipmi_system_interface_addr si;
3084 
3085 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
3086 	si.channel = IPMI_BMC_CHANNEL;
3087 	si.lun = 0;
3088 
3089 	msg.netfn = IPMI_NETFN_APP_REQUEST;
3090 	msg.cmd = IPMI_GET_DEVICE_GUID_CMD;
3091 	msg.data = NULL;
3092 	msg.data_len = 0;
3093 	return i_ipmi_request(NULL,
3094 			      intf,
3095 			      (struct ipmi_addr *) &si,
3096 			      0,
3097 			      &msg,
3098 			      intf,
3099 			      NULL,
3100 			      NULL,
3101 			      0,
3102 			      intf->addrinfo[0].address,
3103 			      intf->addrinfo[0].lun,
3104 			      -1, 0);
3105 }
3106 
3107 static void guid_handler(ipmi_smi_t intf, struct ipmi_recv_msg *msg)
3108 {
3109 	struct bmc_device *bmc = intf->bmc;
3110 
3111 	if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
3112 	    || (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE)
3113 	    || (msg->msg.cmd != IPMI_GET_DEVICE_GUID_CMD))
3114 		/* Not for me */
3115 		return;
3116 
3117 	if (msg->msg.data[0] != 0) {
3118 		/* Error from getting the GUID, the BMC doesn't have one. */
3119 		bmc->dyn_guid_set = 0;
3120 		goto out;
3121 	}
3122 
3123 	if (msg->msg.data_len < 17) {
3124 		bmc->dyn_guid_set = 0;
3125 		dev_warn(intf->si_dev,
3126 			 PFX "The GUID response from the BMC was too short, it was %d but should have been 17.  Assuming GUID is not available.\n",
3127 			 msg->msg.data_len);
3128 		goto out;
3129 	}
3130 
3131 	memcpy(bmc->fetch_guid.b, msg->msg.data + 1, 16);
3132 	/*
3133 	 * Make sure the guid data is available before setting
3134 	 * dyn_guid_set.
3135 	 */
3136 	smp_wmb();
3137 	bmc->dyn_guid_set = 1;
3138  out:
3139 	wake_up(&intf->waitq);
3140 }
3141 
3142 static void __get_guid(ipmi_smi_t intf)
3143 {
3144 	int rv;
3145 	struct bmc_device *bmc = intf->bmc;
3146 
3147 	bmc->dyn_guid_set = 2;
3148 	intf->null_user_handler = guid_handler;
3149 	rv = send_guid_cmd(intf, 0);
3150 	if (rv)
3151 		/* Send failed, no GUID available. */
3152 		bmc->dyn_guid_set = 0;
3153 
3154 	wait_event(intf->waitq, bmc->dyn_guid_set != 2);
3155 
3156 	/* dyn_guid_set makes the guid data available. */
3157 	smp_rmb();
3158 
3159 	intf->null_user_handler = NULL;
3160 }
3161 
3162 static int
3163 send_channel_info_cmd(ipmi_smi_t intf, int chan)
3164 {
3165 	struct kernel_ipmi_msg            msg;
3166 	unsigned char                     data[1];
3167 	struct ipmi_system_interface_addr si;
3168 
3169 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
3170 	si.channel = IPMI_BMC_CHANNEL;
3171 	si.lun = 0;
3172 
3173 	msg.netfn = IPMI_NETFN_APP_REQUEST;
3174 	msg.cmd = IPMI_GET_CHANNEL_INFO_CMD;
3175 	msg.data = data;
3176 	msg.data_len = 1;
3177 	data[0] = chan;
3178 	return i_ipmi_request(NULL,
3179 			      intf,
3180 			      (struct ipmi_addr *) &si,
3181 			      0,
3182 			      &msg,
3183 			      intf,
3184 			      NULL,
3185 			      NULL,
3186 			      0,
3187 			      intf->addrinfo[0].address,
3188 			      intf->addrinfo[0].lun,
3189 			      -1, 0);
3190 }
3191 
3192 static void
3193 channel_handler(ipmi_smi_t intf, struct ipmi_recv_msg *msg)
3194 {
3195 	int rv = 0;
3196 	int ch;
3197 	unsigned int set = intf->curr_working_cset;
3198 	struct ipmi_channel *chans;
3199 
3200 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
3201 	    && (msg->msg.netfn == IPMI_NETFN_APP_RESPONSE)
3202 	    && (msg->msg.cmd == IPMI_GET_CHANNEL_INFO_CMD)) {
3203 		/* It's the one we want */
3204 		if (msg->msg.data[0] != 0) {
3205 			/* Got an error from the channel, just go on. */
3206 
3207 			if (msg->msg.data[0] == IPMI_INVALID_COMMAND_ERR) {
3208 				/*
3209 				 * If the MC does not support this
3210 				 * command, that is legal.  We just
3211 				 * assume it has one IPMB at channel
3212 				 * zero.
3213 				 */
3214 				intf->wchannels[set].c[0].medium
3215 					= IPMI_CHANNEL_MEDIUM_IPMB;
3216 				intf->wchannels[set].c[0].protocol
3217 					= IPMI_CHANNEL_PROTOCOL_IPMB;
3218 
3219 				intf->channel_list = intf->wchannels + set;
3220 				intf->channels_ready = true;
3221 				wake_up(&intf->waitq);
3222 				goto out;
3223 			}
3224 			goto next_channel;
3225 		}
3226 		if (msg->msg.data_len < 4) {
3227 			/* Message not big enough, just go on. */
3228 			goto next_channel;
3229 		}
3230 		ch = intf->curr_channel;
3231 		chans = intf->wchannels[set].c;
3232 		chans[ch].medium = msg->msg.data[2] & 0x7f;
3233 		chans[ch].protocol = msg->msg.data[3] & 0x1f;
3234 
3235  next_channel:
3236 		intf->curr_channel++;
3237 		if (intf->curr_channel >= IPMI_MAX_CHANNELS) {
3238 			intf->channel_list = intf->wchannels + set;
3239 			intf->channels_ready = true;
3240 			wake_up(&intf->waitq);
3241 		} else {
3242 			intf->channel_list = intf->wchannels + set;
3243 			intf->channels_ready = true;
3244 			rv = send_channel_info_cmd(intf, intf->curr_channel);
3245 		}
3246 
3247 		if (rv) {
3248 			/* Got an error somehow, just give up. */
3249 			dev_warn(intf->si_dev,
3250 				 PFX "Error sending channel information for channel %d: %d\n",
3251 				 intf->curr_channel, rv);
3252 
3253 			intf->channel_list = intf->wchannels + set;
3254 			intf->channels_ready = true;
3255 			wake_up(&intf->waitq);
3256 		}
3257 	}
3258  out:
3259 	return;
3260 }
3261 
3262 /*
3263  * Must be holding intf->bmc_reg_mutex to call this.
3264  */
3265 static int __scan_channels(ipmi_smi_t intf, struct ipmi_device_id *id)
3266 {
3267 	int rv;
3268 
3269 	if (ipmi_version_major(id) > 1
3270 			|| (ipmi_version_major(id) == 1
3271 			    && ipmi_version_minor(id) >= 5)) {
3272 		unsigned int set;
3273 
3274 		/*
3275 		 * Start scanning the channels to see what is
3276 		 * available.
3277 		 */
3278 		set = !intf->curr_working_cset;
3279 		intf->curr_working_cset = set;
3280 		memset(&intf->wchannels[set], 0,
3281 		       sizeof(struct ipmi_channel_set));
3282 
3283 		intf->null_user_handler = channel_handler;
3284 		intf->curr_channel = 0;
3285 		rv = send_channel_info_cmd(intf, 0);
3286 		if (rv) {
3287 			dev_warn(intf->si_dev,
3288 				 "Error sending channel information for channel 0, %d\n",
3289 				 rv);
3290 			return -EIO;
3291 		}
3292 
3293 		/* Wait for the channel info to be read. */
3294 		wait_event(intf->waitq, intf->channels_ready);
3295 		intf->null_user_handler = NULL;
3296 	} else {
3297 		unsigned int set = intf->curr_working_cset;
3298 
3299 		/* Assume a single IPMB channel at zero. */
3300 		intf->wchannels[set].c[0].medium = IPMI_CHANNEL_MEDIUM_IPMB;
3301 		intf->wchannels[set].c[0].protocol = IPMI_CHANNEL_PROTOCOL_IPMB;
3302 		intf->channel_list = intf->wchannels + set;
3303 		intf->channels_ready = true;
3304 	}
3305 
3306 	return 0;
3307 }
3308 
3309 static void ipmi_poll(ipmi_smi_t intf)
3310 {
3311 	if (intf->handlers->poll)
3312 		intf->handlers->poll(intf->send_info);
3313 	/* In case something came in */
3314 	handle_new_recv_msgs(intf);
3315 }
3316 
3317 void ipmi_poll_interface(ipmi_user_t user)
3318 {
3319 	ipmi_poll(user->intf);
3320 }
3321 EXPORT_SYMBOL(ipmi_poll_interface);
3322 
3323 static void redo_bmc_reg(struct work_struct *work)
3324 {
3325 	ipmi_smi_t intf = container_of(work, struct ipmi_smi, bmc_reg_work);
3326 
3327 	if (!intf->in_shutdown)
3328 		bmc_get_device_id(intf, NULL, NULL, NULL, NULL);
3329 
3330 	kref_put(&intf->refcount, intf_free);
3331 }
3332 
3333 int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
3334 		      void		       *send_info,
3335 		      struct device            *si_dev,
3336 		      unsigned char            slave_addr)
3337 {
3338 	int              i, j;
3339 	int              rv;
3340 	ipmi_smi_t       intf;
3341 	ipmi_smi_t       tintf;
3342 	struct list_head *link;
3343 	struct ipmi_device_id id;
3344 
3345 	/*
3346 	 * Make sure the driver is actually initialized, this handles
3347 	 * problems with initialization order.
3348 	 */
3349 	if (!initialized) {
3350 		rv = ipmi_init_msghandler();
3351 		if (rv)
3352 			return rv;
3353 		/*
3354 		 * The init code doesn't return an error if it was turned
3355 		 * off, but it won't initialize.  Check that.
3356 		 */
3357 		if (!initialized)
3358 			return -ENODEV;
3359 	}
3360 
3361 	intf = kzalloc(sizeof(*intf), GFP_KERNEL);
3362 	if (!intf)
3363 		return -ENOMEM;
3364 
3365 	intf->bmc = &intf->tmp_bmc;
3366 	INIT_LIST_HEAD(&intf->bmc->intfs);
3367 	mutex_init(&intf->bmc->dyn_mutex);
3368 	INIT_LIST_HEAD(&intf->bmc_link);
3369 	mutex_init(&intf->bmc_reg_mutex);
3370 	intf->intf_num = -1; /* Mark it invalid for now. */
3371 	kref_init(&intf->refcount);
3372 	INIT_WORK(&intf->bmc_reg_work, redo_bmc_reg);
3373 	intf->si_dev = si_dev;
3374 	for (j = 0; j < IPMI_MAX_CHANNELS; j++) {
3375 		intf->addrinfo[j].address = IPMI_BMC_SLAVE_ADDR;
3376 		intf->addrinfo[j].lun = 2;
3377 	}
3378 	if (slave_addr != 0)
3379 		intf->addrinfo[0].address = slave_addr;
3380 	INIT_LIST_HEAD(&intf->users);
3381 	intf->handlers = handlers;
3382 	intf->send_info = send_info;
3383 	spin_lock_init(&intf->seq_lock);
3384 	for (j = 0; j < IPMI_IPMB_NUM_SEQ; j++) {
3385 		intf->seq_table[j].inuse = 0;
3386 		intf->seq_table[j].seqid = 0;
3387 	}
3388 	intf->curr_seq = 0;
3389 #ifdef CONFIG_IPMI_PROC_INTERFACE
3390 	mutex_init(&intf->proc_entry_lock);
3391 #endif
3392 	spin_lock_init(&intf->waiting_rcv_msgs_lock);
3393 	INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
3394 	tasklet_init(&intf->recv_tasklet,
3395 		     smi_recv_tasklet,
3396 		     (unsigned long) intf);
3397 	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 0);
3398 	spin_lock_init(&intf->xmit_msgs_lock);
3399 	INIT_LIST_HEAD(&intf->xmit_msgs);
3400 	INIT_LIST_HEAD(&intf->hp_xmit_msgs);
3401 	spin_lock_init(&intf->events_lock);
3402 	atomic_set(&intf->event_waiters, 0);
3403 	intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
3404 	INIT_LIST_HEAD(&intf->waiting_events);
3405 	intf->waiting_events_count = 0;
3406 	mutex_init(&intf->cmd_rcvrs_mutex);
3407 	spin_lock_init(&intf->maintenance_mode_lock);
3408 	INIT_LIST_HEAD(&intf->cmd_rcvrs);
3409 	init_waitqueue_head(&intf->waitq);
3410 	for (i = 0; i < IPMI_NUM_STATS; i++)
3411 		atomic_set(&intf->stats[i], 0);
3412 
3413 #ifdef CONFIG_IPMI_PROC_INTERFACE
3414 	intf->proc_dir = NULL;
3415 #endif
3416 
3417 	mutex_lock(&smi_watchers_mutex);
3418 	mutex_lock(&ipmi_interfaces_mutex);
3419 	/* Look for a hole in the numbers. */
3420 	i = 0;
3421 	link = &ipmi_interfaces;
3422 	list_for_each_entry_rcu(tintf, &ipmi_interfaces, link) {
3423 		if (tintf->intf_num != i) {
3424 			link = &tintf->link;
3425 			break;
3426 		}
3427 		i++;
3428 	}
3429 	/* Add the new interface in numeric order. */
3430 	if (i == 0)
3431 		list_add_rcu(&intf->link, &ipmi_interfaces);
3432 	else
3433 		list_add_tail_rcu(&intf->link, link);
3434 
3435 	rv = handlers->start_processing(send_info, intf);
3436 	if (rv)
3437 		goto out;
3438 
3439 	rv = __bmc_get_device_id(intf, NULL, &id, NULL, NULL, i);
3440 	if (rv) {
3441 		dev_err(si_dev, "Unable to get the device id: %d\n", rv);
3442 		goto out;
3443 	}
3444 
3445 	mutex_lock(&intf->bmc_reg_mutex);
3446 	rv = __scan_channels(intf, &id);
3447 	mutex_unlock(&intf->bmc_reg_mutex);
3448 	if (rv)
3449 		goto out;
3450 
3451 #ifdef CONFIG_IPMI_PROC_INTERFACE
3452 	rv = add_proc_entries(intf, i);
3453 #endif
3454 
3455  out:
3456 	if (rv) {
3457 		ipmi_bmc_unregister(intf);
3458 #ifdef CONFIG_IPMI_PROC_INTERFACE
3459 		if (intf->proc_dir)
3460 			remove_proc_entries(intf);
3461 #endif
3462 		intf->handlers = NULL;
3463 		list_del_rcu(&intf->link);
3464 		mutex_unlock(&ipmi_interfaces_mutex);
3465 		mutex_unlock(&smi_watchers_mutex);
3466 		synchronize_rcu();
3467 		kref_put(&intf->refcount, intf_free);
3468 	} else {
3469 		/*
3470 		 * Keep memory order straight for RCU readers.  Make
3471 		 * sure everything else is committed to memory before
3472 		 * setting intf_num to mark the interface valid.
3473 		 */
3474 		smp_wmb();
3475 		intf->intf_num = i;
3476 		mutex_unlock(&ipmi_interfaces_mutex);
3477 		/* After this point the interface is legal to use. */
3478 		call_smi_watchers(i, intf->si_dev);
3479 		mutex_unlock(&smi_watchers_mutex);
3480 	}
3481 
3482 	return rv;
3483 }
3484 EXPORT_SYMBOL(ipmi_register_smi);
3485 
3486 static void deliver_smi_err_response(ipmi_smi_t intf,
3487 				     struct ipmi_smi_msg *msg,
3488 				     unsigned char err)
3489 {
3490 	msg->rsp[0] = msg->data[0] | 4;
3491 	msg->rsp[1] = msg->data[1];
3492 	msg->rsp[2] = err;
3493 	msg->rsp_size = 3;
3494 	/* It's an error, so it will never requeue, no need to check return. */
3495 	handle_one_recv_msg(intf, msg);
3496 }
3497 
3498 static void cleanup_smi_msgs(ipmi_smi_t intf)
3499 {
3500 	int              i;
3501 	struct seq_table *ent;
3502 	struct ipmi_smi_msg *msg;
3503 	struct list_head *entry;
3504 	struct list_head tmplist;
3505 
3506 	/* Clear out our transmit queues and hold the messages. */
3507 	INIT_LIST_HEAD(&tmplist);
3508 	list_splice_tail(&intf->hp_xmit_msgs, &tmplist);
3509 	list_splice_tail(&intf->xmit_msgs, &tmplist);
3510 
3511 	/* Current message first, to preserve order */
3512 	while (intf->curr_msg && !list_empty(&intf->waiting_rcv_msgs)) {
3513 		/* Wait for the message to clear out. */
3514 		schedule_timeout(1);
3515 	}
3516 
3517 	/* No need for locks, the interface is down. */
3518 
3519 	/*
3520 	 * Return errors for all pending messages in queue and in the
3521 	 * tables waiting for remote responses.
3522 	 */
3523 	while (!list_empty(&tmplist)) {
3524 		entry = tmplist.next;
3525 		list_del(entry);
3526 		msg = list_entry(entry, struct ipmi_smi_msg, link);
3527 		deliver_smi_err_response(intf, msg, IPMI_ERR_UNSPECIFIED);
3528 	}
3529 
3530 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
3531 		ent = &(intf->seq_table[i]);
3532 		if (!ent->inuse)
3533 			continue;
3534 		deliver_err_response(ent->recv_msg, IPMI_ERR_UNSPECIFIED);
3535 	}
3536 }
3537 
3538 int ipmi_unregister_smi(ipmi_smi_t intf)
3539 {
3540 	struct ipmi_smi_watcher *w;
3541 	int intf_num = intf->intf_num;
3542 	ipmi_user_t user;
3543 
3544 	mutex_lock(&smi_watchers_mutex);
3545 	mutex_lock(&ipmi_interfaces_mutex);
3546 	intf->intf_num = -1;
3547 	intf->in_shutdown = true;
3548 	list_del_rcu(&intf->link);
3549 	mutex_unlock(&ipmi_interfaces_mutex);
3550 	synchronize_rcu();
3551 
3552 	cleanup_smi_msgs(intf);
3553 
3554 	/* Clean up the effects of users on the lower-level software. */
3555 	mutex_lock(&ipmi_interfaces_mutex);
3556 	rcu_read_lock();
3557 	list_for_each_entry_rcu(user, &intf->users, link) {
3558 		module_put(intf->handlers->owner);
3559 		if (intf->handlers->dec_usecount)
3560 			intf->handlers->dec_usecount(intf->send_info);
3561 	}
3562 	rcu_read_unlock();
3563 	intf->handlers = NULL;
3564 	mutex_unlock(&ipmi_interfaces_mutex);
3565 
3566 #ifdef CONFIG_IPMI_PROC_INTERFACE
3567 	remove_proc_entries(intf);
3568 #endif
3569 	ipmi_bmc_unregister(intf);
3570 
3571 	/*
3572 	 * Call all the watcher interfaces to tell them that
3573 	 * an interface is gone.
3574 	 */
3575 	list_for_each_entry(w, &smi_watchers, link)
3576 		w->smi_gone(intf_num);
3577 	mutex_unlock(&smi_watchers_mutex);
3578 
3579 	kref_put(&intf->refcount, intf_free);
3580 	return 0;
3581 }
3582 EXPORT_SYMBOL(ipmi_unregister_smi);
3583 
3584 static int handle_ipmb_get_msg_rsp(ipmi_smi_t          intf,
3585 				   struct ipmi_smi_msg *msg)
3586 {
3587 	struct ipmi_ipmb_addr ipmb_addr;
3588 	struct ipmi_recv_msg  *recv_msg;
3589 
3590 	/*
3591 	 * This is 11, not 10, because the response must contain a
3592 	 * completion code.
3593 	 */
3594 	if (msg->rsp_size < 11) {
3595 		/* Message not big enough, just ignore it. */
3596 		ipmi_inc_stat(intf, invalid_ipmb_responses);
3597 		return 0;
3598 	}
3599 
3600 	if (msg->rsp[2] != 0) {
3601 		/* An error getting the response, just ignore it. */
3602 		return 0;
3603 	}
3604 
3605 	ipmb_addr.addr_type = IPMI_IPMB_ADDR_TYPE;
3606 	ipmb_addr.slave_addr = msg->rsp[6];
3607 	ipmb_addr.channel = msg->rsp[3] & 0x0f;
3608 	ipmb_addr.lun = msg->rsp[7] & 3;
3609 
3610 	/*
3611 	 * It's a response from a remote entity.  Look up the sequence
3612 	 * number and handle the response.
3613 	 */
3614 	if (intf_find_seq(intf,
3615 			  msg->rsp[7] >> 2,
3616 			  msg->rsp[3] & 0x0f,
3617 			  msg->rsp[8],
3618 			  (msg->rsp[4] >> 2) & (~1),
3619 			  (struct ipmi_addr *) &(ipmb_addr),
3620 			  &recv_msg)) {
3621 		/*
3622 		 * We were unable to find the sequence number,
3623 		 * so just nuke the message.
3624 		 */
3625 		ipmi_inc_stat(intf, unhandled_ipmb_responses);
3626 		return 0;
3627 	}
3628 
3629 	memcpy(recv_msg->msg_data,
3630 	       &(msg->rsp[9]),
3631 	       msg->rsp_size - 9);
3632 	/*
3633 	 * The other fields matched, so no need to set them, except
3634 	 * for netfn, which needs to be the response that was
3635 	 * returned, not the request value.
3636 	 */
3637 	recv_msg->msg.netfn = msg->rsp[4] >> 2;
3638 	recv_msg->msg.data = recv_msg->msg_data;
3639 	recv_msg->msg.data_len = msg->rsp_size - 10;
3640 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
3641 	ipmi_inc_stat(intf, handled_ipmb_responses);
3642 	deliver_response(recv_msg);
3643 
3644 	return 0;
3645 }
3646 
3647 static int handle_ipmb_get_msg_cmd(ipmi_smi_t          intf,
3648 				   struct ipmi_smi_msg *msg)
3649 {
3650 	struct cmd_rcvr          *rcvr;
3651 	int                      rv = 0;
3652 	unsigned char            netfn;
3653 	unsigned char            cmd;
3654 	unsigned char            chan;
3655 	ipmi_user_t              user = NULL;
3656 	struct ipmi_ipmb_addr    *ipmb_addr;
3657 	struct ipmi_recv_msg     *recv_msg;
3658 
3659 	if (msg->rsp_size < 10) {
3660 		/* Message not big enough, just ignore it. */
3661 		ipmi_inc_stat(intf, invalid_commands);
3662 		return 0;
3663 	}
3664 
3665 	if (msg->rsp[2] != 0) {
3666 		/* An error getting the response, just ignore it. */
3667 		return 0;
3668 	}
3669 
3670 	netfn = msg->rsp[4] >> 2;
3671 	cmd = msg->rsp[8];
3672 	chan = msg->rsp[3] & 0xf;
3673 
3674 	rcu_read_lock();
3675 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
3676 	if (rcvr) {
3677 		user = rcvr->user;
3678 		kref_get(&user->refcount);
3679 	} else
3680 		user = NULL;
3681 	rcu_read_unlock();
3682 
3683 	if (user == NULL) {
3684 		/* We didn't find a user, deliver an error response. */
3685 		ipmi_inc_stat(intf, unhandled_commands);
3686 
3687 		msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
3688 		msg->data[1] = IPMI_SEND_MSG_CMD;
3689 		msg->data[2] = msg->rsp[3];
3690 		msg->data[3] = msg->rsp[6];
3691 		msg->data[4] = ((netfn + 1) << 2) | (msg->rsp[7] & 0x3);
3692 		msg->data[5] = ipmb_checksum(&(msg->data[3]), 2);
3693 		msg->data[6] = intf->addrinfo[msg->rsp[3] & 0xf].address;
3694 		/* rqseq/lun */
3695 		msg->data[7] = (msg->rsp[7] & 0xfc) | (msg->rsp[4] & 0x3);
3696 		msg->data[8] = msg->rsp[8]; /* cmd */
3697 		msg->data[9] = IPMI_INVALID_CMD_COMPLETION_CODE;
3698 		msg->data[10] = ipmb_checksum(&(msg->data[6]), 4);
3699 		msg->data_size = 11;
3700 
3701 #ifdef DEBUG_MSGING
3702 	{
3703 		int m;
3704 		printk("Invalid command:");
3705 		for (m = 0; m < msg->data_size; m++)
3706 			printk(" %2.2x", msg->data[m]);
3707 		printk("\n");
3708 	}
3709 #endif
3710 		rcu_read_lock();
3711 		if (!intf->in_shutdown) {
3712 			smi_send(intf, intf->handlers, msg, 0);
3713 			/*
3714 			 * We used the message, so return the value
3715 			 * that causes it to not be freed or
3716 			 * queued.
3717 			 */
3718 			rv = -1;
3719 		}
3720 		rcu_read_unlock();
3721 	} else {
3722 		/* Deliver the message to the user. */
3723 		ipmi_inc_stat(intf, handled_commands);
3724 
3725 		recv_msg = ipmi_alloc_recv_msg();
3726 		if (!recv_msg) {
3727 			/*
3728 			 * We couldn't allocate memory for the
3729 			 * message, so requeue it for handling
3730 			 * later.
3731 			 */
3732 			rv = 1;
3733 			kref_put(&user->refcount, free_user);
3734 		} else {
3735 			/* Extract the source address from the data. */
3736 			ipmb_addr = (struct ipmi_ipmb_addr *) &recv_msg->addr;
3737 			ipmb_addr->addr_type = IPMI_IPMB_ADDR_TYPE;
3738 			ipmb_addr->slave_addr = msg->rsp[6];
3739 			ipmb_addr->lun = msg->rsp[7] & 3;
3740 			ipmb_addr->channel = msg->rsp[3] & 0xf;
3741 
3742 			/*
3743 			 * Extract the rest of the message information
3744 			 * from the IPMB header.
3745 			 */
3746 			recv_msg->user = user;
3747 			recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
3748 			recv_msg->msgid = msg->rsp[7] >> 2;
3749 			recv_msg->msg.netfn = msg->rsp[4] >> 2;
3750 			recv_msg->msg.cmd = msg->rsp[8];
3751 			recv_msg->msg.data = recv_msg->msg_data;
3752 
3753 			/*
3754 			 * We chop off 10, not 9 bytes because the checksum
3755 			 * at the end also needs to be removed.
3756 			 */
3757 			recv_msg->msg.data_len = msg->rsp_size - 10;
3758 			memcpy(recv_msg->msg_data,
3759 			       &(msg->rsp[9]),
3760 			       msg->rsp_size - 10);
3761 			deliver_response(recv_msg);
3762 		}
3763 	}
3764 
3765 	return rv;
3766 }
3767 
3768 static int handle_lan_get_msg_rsp(ipmi_smi_t          intf,
3769 				  struct ipmi_smi_msg *msg)
3770 {
3771 	struct ipmi_lan_addr  lan_addr;
3772 	struct ipmi_recv_msg  *recv_msg;
3773 
3774 
3775 	/*
3776 	 * This is 13, not 12, because the response must contain a
3777 	 * completion code.
3778 	 */
3779 	if (msg->rsp_size < 13) {
3780 		/* Message not big enough, just ignore it. */
3781 		ipmi_inc_stat(intf, invalid_lan_responses);
3782 		return 0;
3783 	}
3784 
3785 	if (msg->rsp[2] != 0) {
3786 		/* An error getting the response, just ignore it. */
3787 		return 0;
3788 	}
3789 
3790 	lan_addr.addr_type = IPMI_LAN_ADDR_TYPE;
3791 	lan_addr.session_handle = msg->rsp[4];
3792 	lan_addr.remote_SWID = msg->rsp[8];
3793 	lan_addr.local_SWID = msg->rsp[5];
3794 	lan_addr.channel = msg->rsp[3] & 0x0f;
3795 	lan_addr.privilege = msg->rsp[3] >> 4;
3796 	lan_addr.lun = msg->rsp[9] & 3;
3797 
3798 	/*
3799 	 * It's a response from a remote entity.  Look up the sequence
3800 	 * number and handle the response.
3801 	 */
3802 	if (intf_find_seq(intf,
3803 			  msg->rsp[9] >> 2,
3804 			  msg->rsp[3] & 0x0f,
3805 			  msg->rsp[10],
3806 			  (msg->rsp[6] >> 2) & (~1),
3807 			  (struct ipmi_addr *) &(lan_addr),
3808 			  &recv_msg)) {
3809 		/*
3810 		 * We were unable to find the sequence number,
3811 		 * so just nuke the message.
3812 		 */
3813 		ipmi_inc_stat(intf, unhandled_lan_responses);
3814 		return 0;
3815 	}
3816 
3817 	memcpy(recv_msg->msg_data,
3818 	       &(msg->rsp[11]),
3819 	       msg->rsp_size - 11);
3820 	/*
3821 	 * The other fields matched, so no need to set them, except
3822 	 * for netfn, which needs to be the response that was
3823 	 * returned, not the request value.
3824 	 */
3825 	recv_msg->msg.netfn = msg->rsp[6] >> 2;
3826 	recv_msg->msg.data = recv_msg->msg_data;
3827 	recv_msg->msg.data_len = msg->rsp_size - 12;
3828 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
3829 	ipmi_inc_stat(intf, handled_lan_responses);
3830 	deliver_response(recv_msg);
3831 
3832 	return 0;
3833 }
3834 
3835 static int handle_lan_get_msg_cmd(ipmi_smi_t          intf,
3836 				  struct ipmi_smi_msg *msg)
3837 {
3838 	struct cmd_rcvr          *rcvr;
3839 	int                      rv = 0;
3840 	unsigned char            netfn;
3841 	unsigned char            cmd;
3842 	unsigned char            chan;
3843 	ipmi_user_t              user = NULL;
3844 	struct ipmi_lan_addr     *lan_addr;
3845 	struct ipmi_recv_msg     *recv_msg;
3846 
3847 	if (msg->rsp_size < 12) {
3848 		/* Message not big enough, just ignore it. */
3849 		ipmi_inc_stat(intf, invalid_commands);
3850 		return 0;
3851 	}
3852 
3853 	if (msg->rsp[2] != 0) {
3854 		/* An error getting the response, just ignore it. */
3855 		return 0;
3856 	}
3857 
3858 	netfn = msg->rsp[6] >> 2;
3859 	cmd = msg->rsp[10];
3860 	chan = msg->rsp[3] & 0xf;
3861 
3862 	rcu_read_lock();
3863 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
3864 	if (rcvr) {
3865 		user = rcvr->user;
3866 		kref_get(&user->refcount);
3867 	} else
3868 		user = NULL;
3869 	rcu_read_unlock();
3870 
3871 	if (user == NULL) {
3872 		/* We didn't find a user, just give up. */
3873 		ipmi_inc_stat(intf, unhandled_commands);
3874 
3875 		/*
3876 		 * Don't do anything with these messages, just allow
3877 		 * them to be freed.
3878 		 */
3879 		rv = 0;
3880 	} else {
3881 		/* Deliver the message to the user. */
3882 		ipmi_inc_stat(intf, handled_commands);
3883 
3884 		recv_msg = ipmi_alloc_recv_msg();
3885 		if (!recv_msg) {
3886 			/*
3887 			 * We couldn't allocate memory for the
3888 			 * message, so requeue it for handling later.
3889 			 */
3890 			rv = 1;
3891 			kref_put(&user->refcount, free_user);
3892 		} else {
3893 			/* Extract the source address from the data. */
3894 			lan_addr = (struct ipmi_lan_addr *) &recv_msg->addr;
3895 			lan_addr->addr_type = IPMI_LAN_ADDR_TYPE;
3896 			lan_addr->session_handle = msg->rsp[4];
3897 			lan_addr->remote_SWID = msg->rsp[8];
3898 			lan_addr->local_SWID = msg->rsp[5];
3899 			lan_addr->lun = msg->rsp[9] & 3;
3900 			lan_addr->channel = msg->rsp[3] & 0xf;
3901 			lan_addr->privilege = msg->rsp[3] >> 4;
3902 
3903 			/*
3904 			 * Extract the rest of the message information
3905 			 * from the IPMB header.
3906 			 */
3907 			recv_msg->user = user;
3908 			recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
3909 			recv_msg->msgid = msg->rsp[9] >> 2;
3910 			recv_msg->msg.netfn = msg->rsp[6] >> 2;
3911 			recv_msg->msg.cmd = msg->rsp[10];
3912 			recv_msg->msg.data = recv_msg->msg_data;
3913 
3914 			/*
3915 			 * We chop off 12, not 11 bytes because the checksum
3916 			 * at the end also needs to be removed.
3917 			 */
3918 			recv_msg->msg.data_len = msg->rsp_size - 12;
3919 			memcpy(recv_msg->msg_data,
3920 			       &(msg->rsp[11]),
3921 			       msg->rsp_size - 12);
3922 			deliver_response(recv_msg);
3923 		}
3924 	}
3925 
3926 	return rv;
3927 }
3928 
3929 /*
3930  * This routine will handle "Get Message" command responses with
3931  * channels that use an OEM Medium. The message format belongs to
3932  * the OEM.  See IPMI 2.0 specification, Chapter 6 and
3933  * Chapter 22, sections 22.6 and 22.24 for more details.
3934  */
3935 static int handle_oem_get_msg_cmd(ipmi_smi_t          intf,
3936 				  struct ipmi_smi_msg *msg)
3937 {
3938 	struct cmd_rcvr       *rcvr;
3939 	int                   rv = 0;
3940 	unsigned char         netfn;
3941 	unsigned char         cmd;
3942 	unsigned char         chan;
3943 	ipmi_user_t           user = NULL;
3944 	struct ipmi_system_interface_addr *smi_addr;
3945 	struct ipmi_recv_msg  *recv_msg;
3946 
3947 	/*
3948 	 * We expect the OEM SW to perform error checking
3949 	 * so we just do some basic sanity checks
3950 	 */
3951 	if (msg->rsp_size < 4) {
3952 		/* Message not big enough, just ignore it. */
3953 		ipmi_inc_stat(intf, invalid_commands);
3954 		return 0;
3955 	}
3956 
3957 	if (msg->rsp[2] != 0) {
3958 		/* An error getting the response, just ignore it. */
3959 		return 0;
3960 	}
3961 
3962 	/*
3963 	 * This is an OEM Message so the OEM needs to know how
3964 	 * handle the message. We do no interpretation.
3965 	 */
3966 	netfn = msg->rsp[0] >> 2;
3967 	cmd = msg->rsp[1];
3968 	chan = msg->rsp[3] & 0xf;
3969 
3970 	rcu_read_lock();
3971 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
3972 	if (rcvr) {
3973 		user = rcvr->user;
3974 		kref_get(&user->refcount);
3975 	} else
3976 		user = NULL;
3977 	rcu_read_unlock();
3978 
3979 	if (user == NULL) {
3980 		/* We didn't find a user, just give up. */
3981 		ipmi_inc_stat(intf, unhandled_commands);
3982 
3983 		/*
3984 		 * Don't do anything with these messages, just allow
3985 		 * them to be freed.
3986 		 */
3987 
3988 		rv = 0;
3989 	} else {
3990 		/* Deliver the message to the user. */
3991 		ipmi_inc_stat(intf, handled_commands);
3992 
3993 		recv_msg = ipmi_alloc_recv_msg();
3994 		if (!recv_msg) {
3995 			/*
3996 			 * We couldn't allocate memory for the
3997 			 * message, so requeue it for handling
3998 			 * later.
3999 			 */
4000 			rv = 1;
4001 			kref_put(&user->refcount, free_user);
4002 		} else {
4003 			/*
4004 			 * OEM Messages are expected to be delivered via
4005 			 * the system interface to SMS software.  We might
4006 			 * need to visit this again depending on OEM
4007 			 * requirements
4008 			 */
4009 			smi_addr = ((struct ipmi_system_interface_addr *)
4010 				    &(recv_msg->addr));
4011 			smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4012 			smi_addr->channel = IPMI_BMC_CHANNEL;
4013 			smi_addr->lun = msg->rsp[0] & 3;
4014 
4015 			recv_msg->user = user;
4016 			recv_msg->user_msg_data = NULL;
4017 			recv_msg->recv_type = IPMI_OEM_RECV_TYPE;
4018 			recv_msg->msg.netfn = msg->rsp[0] >> 2;
4019 			recv_msg->msg.cmd = msg->rsp[1];
4020 			recv_msg->msg.data = recv_msg->msg_data;
4021 
4022 			/*
4023 			 * The message starts at byte 4 which follows the
4024 			 * the Channel Byte in the "GET MESSAGE" command
4025 			 */
4026 			recv_msg->msg.data_len = msg->rsp_size - 4;
4027 			memcpy(recv_msg->msg_data,
4028 			       &(msg->rsp[4]),
4029 			       msg->rsp_size - 4);
4030 			deliver_response(recv_msg);
4031 		}
4032 	}
4033 
4034 	return rv;
4035 }
4036 
4037 static void copy_event_into_recv_msg(struct ipmi_recv_msg *recv_msg,
4038 				     struct ipmi_smi_msg  *msg)
4039 {
4040 	struct ipmi_system_interface_addr *smi_addr;
4041 
4042 	recv_msg->msgid = 0;
4043 	smi_addr = (struct ipmi_system_interface_addr *) &(recv_msg->addr);
4044 	smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4045 	smi_addr->channel = IPMI_BMC_CHANNEL;
4046 	smi_addr->lun = msg->rsp[0] & 3;
4047 	recv_msg->recv_type = IPMI_ASYNC_EVENT_RECV_TYPE;
4048 	recv_msg->msg.netfn = msg->rsp[0] >> 2;
4049 	recv_msg->msg.cmd = msg->rsp[1];
4050 	memcpy(recv_msg->msg_data, &(msg->rsp[3]), msg->rsp_size - 3);
4051 	recv_msg->msg.data = recv_msg->msg_data;
4052 	recv_msg->msg.data_len = msg->rsp_size - 3;
4053 }
4054 
4055 static int handle_read_event_rsp(ipmi_smi_t          intf,
4056 				 struct ipmi_smi_msg *msg)
4057 {
4058 	struct ipmi_recv_msg *recv_msg, *recv_msg2;
4059 	struct list_head     msgs;
4060 	ipmi_user_t          user;
4061 	int                  rv = 0;
4062 	int                  deliver_count = 0;
4063 	unsigned long        flags;
4064 
4065 	if (msg->rsp_size < 19) {
4066 		/* Message is too small to be an IPMB event. */
4067 		ipmi_inc_stat(intf, invalid_events);
4068 		return 0;
4069 	}
4070 
4071 	if (msg->rsp[2] != 0) {
4072 		/* An error getting the event, just ignore it. */
4073 		return 0;
4074 	}
4075 
4076 	INIT_LIST_HEAD(&msgs);
4077 
4078 	spin_lock_irqsave(&intf->events_lock, flags);
4079 
4080 	ipmi_inc_stat(intf, events);
4081 
4082 	/*
4083 	 * Allocate and fill in one message for every user that is
4084 	 * getting events.
4085 	 */
4086 	rcu_read_lock();
4087 	list_for_each_entry_rcu(user, &intf->users, link) {
4088 		if (!user->gets_events)
4089 			continue;
4090 
4091 		recv_msg = ipmi_alloc_recv_msg();
4092 		if (!recv_msg) {
4093 			rcu_read_unlock();
4094 			list_for_each_entry_safe(recv_msg, recv_msg2, &msgs,
4095 						 link) {
4096 				list_del(&recv_msg->link);
4097 				ipmi_free_recv_msg(recv_msg);
4098 			}
4099 			/*
4100 			 * We couldn't allocate memory for the
4101 			 * message, so requeue it for handling
4102 			 * later.
4103 			 */
4104 			rv = 1;
4105 			goto out;
4106 		}
4107 
4108 		deliver_count++;
4109 
4110 		copy_event_into_recv_msg(recv_msg, msg);
4111 		recv_msg->user = user;
4112 		kref_get(&user->refcount);
4113 		list_add_tail(&(recv_msg->link), &msgs);
4114 	}
4115 	rcu_read_unlock();
4116 
4117 	if (deliver_count) {
4118 		/* Now deliver all the messages. */
4119 		list_for_each_entry_safe(recv_msg, recv_msg2, &msgs, link) {
4120 			list_del(&recv_msg->link);
4121 			deliver_response(recv_msg);
4122 		}
4123 	} else if (intf->waiting_events_count < MAX_EVENTS_IN_QUEUE) {
4124 		/*
4125 		 * No one to receive the message, put it in queue if there's
4126 		 * not already too many things in the queue.
4127 		 */
4128 		recv_msg = ipmi_alloc_recv_msg();
4129 		if (!recv_msg) {
4130 			/*
4131 			 * We couldn't allocate memory for the
4132 			 * message, so requeue it for handling
4133 			 * later.
4134 			 */
4135 			rv = 1;
4136 			goto out;
4137 		}
4138 
4139 		copy_event_into_recv_msg(recv_msg, msg);
4140 		list_add_tail(&(recv_msg->link), &(intf->waiting_events));
4141 		intf->waiting_events_count++;
4142 	} else if (!intf->event_msg_printed) {
4143 		/*
4144 		 * There's too many things in the queue, discard this
4145 		 * message.
4146 		 */
4147 		dev_warn(intf->si_dev,
4148 			 PFX "Event queue full, discarding incoming events\n");
4149 		intf->event_msg_printed = 1;
4150 	}
4151 
4152  out:
4153 	spin_unlock_irqrestore(&(intf->events_lock), flags);
4154 
4155 	return rv;
4156 }
4157 
4158 static int handle_bmc_rsp(ipmi_smi_t          intf,
4159 			  struct ipmi_smi_msg *msg)
4160 {
4161 	struct ipmi_recv_msg *recv_msg;
4162 	struct ipmi_user     *user;
4163 
4164 	recv_msg = (struct ipmi_recv_msg *) msg->user_data;
4165 	if (recv_msg == NULL) {
4166 		dev_warn(intf->si_dev,
4167 			 "IPMI message received with no owner. This could be because of a malformed message, or because of a hardware error.  Contact your hardware vender for assistance\n");
4168 		return 0;
4169 	}
4170 
4171 	user = recv_msg->user;
4172 	/* Make sure the user still exists. */
4173 	if (user && !user->valid) {
4174 		/* The user for the message went away, so give up. */
4175 		ipmi_inc_stat(intf, unhandled_local_responses);
4176 		ipmi_free_recv_msg(recv_msg);
4177 	} else {
4178 		struct ipmi_system_interface_addr *smi_addr;
4179 
4180 		ipmi_inc_stat(intf, handled_local_responses);
4181 		recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
4182 		recv_msg->msgid = msg->msgid;
4183 		smi_addr = ((struct ipmi_system_interface_addr *)
4184 			    &(recv_msg->addr));
4185 		smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4186 		smi_addr->channel = IPMI_BMC_CHANNEL;
4187 		smi_addr->lun = msg->rsp[0] & 3;
4188 		recv_msg->msg.netfn = msg->rsp[0] >> 2;
4189 		recv_msg->msg.cmd = msg->rsp[1];
4190 		memcpy(recv_msg->msg_data,
4191 		       &(msg->rsp[2]),
4192 		       msg->rsp_size - 2);
4193 		recv_msg->msg.data = recv_msg->msg_data;
4194 		recv_msg->msg.data_len = msg->rsp_size - 2;
4195 		deliver_response(recv_msg);
4196 	}
4197 
4198 	return 0;
4199 }
4200 
4201 /*
4202  * Handle a received message.  Return 1 if the message should be requeued,
4203  * 0 if the message should be freed, or -1 if the message should not
4204  * be freed or requeued.
4205  */
4206 static int handle_one_recv_msg(ipmi_smi_t          intf,
4207 			       struct ipmi_smi_msg *msg)
4208 {
4209 	int requeue;
4210 	int chan;
4211 
4212 #ifdef DEBUG_MSGING
4213 	int m;
4214 	printk("Recv:");
4215 	for (m = 0; m < msg->rsp_size; m++)
4216 		printk(" %2.2x", msg->rsp[m]);
4217 	printk("\n");
4218 #endif
4219 	if (msg->rsp_size < 2) {
4220 		/* Message is too small to be correct. */
4221 		dev_warn(intf->si_dev,
4222 			 PFX "BMC returned to small a message for netfn %x cmd %x, got %d bytes\n",
4223 			 (msg->data[0] >> 2) | 1, msg->data[1], msg->rsp_size);
4224 
4225 		/* Generate an error response for the message. */
4226 		msg->rsp[0] = msg->data[0] | (1 << 2);
4227 		msg->rsp[1] = msg->data[1];
4228 		msg->rsp[2] = IPMI_ERR_UNSPECIFIED;
4229 		msg->rsp_size = 3;
4230 	} else if (((msg->rsp[0] >> 2) != ((msg->data[0] >> 2) | 1))
4231 		   || (msg->rsp[1] != msg->data[1])) {
4232 		/*
4233 		 * The NetFN and Command in the response is not even
4234 		 * marginally correct.
4235 		 */
4236 		dev_warn(intf->si_dev,
4237 			 PFX "BMC returned incorrect response, expected netfn %x cmd %x, got netfn %x cmd %x\n",
4238 			 (msg->data[0] >> 2) | 1, msg->data[1],
4239 			 msg->rsp[0] >> 2, msg->rsp[1]);
4240 
4241 		/* Generate an error response for the message. */
4242 		msg->rsp[0] = msg->data[0] | (1 << 2);
4243 		msg->rsp[1] = msg->data[1];
4244 		msg->rsp[2] = IPMI_ERR_UNSPECIFIED;
4245 		msg->rsp_size = 3;
4246 	}
4247 
4248 	if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4249 	    && (msg->rsp[1] == IPMI_SEND_MSG_CMD)
4250 	    && (msg->user_data != NULL)) {
4251 		/*
4252 		 * It's a response to a response we sent.  For this we
4253 		 * deliver a send message response to the user.
4254 		 */
4255 		struct ipmi_recv_msg     *recv_msg = msg->user_data;
4256 
4257 		requeue = 0;
4258 		if (msg->rsp_size < 2)
4259 			/* Message is too small to be correct. */
4260 			goto out;
4261 
4262 		chan = msg->data[2] & 0x0f;
4263 		if (chan >= IPMI_MAX_CHANNELS)
4264 			/* Invalid channel number */
4265 			goto out;
4266 
4267 		if (!recv_msg)
4268 			goto out;
4269 
4270 		/* Make sure the user still exists. */
4271 		if (!recv_msg->user || !recv_msg->user->valid)
4272 			goto out;
4273 
4274 		recv_msg->recv_type = IPMI_RESPONSE_RESPONSE_TYPE;
4275 		recv_msg->msg.data = recv_msg->msg_data;
4276 		recv_msg->msg.data_len = 1;
4277 		recv_msg->msg_data[0] = msg->rsp[2];
4278 		deliver_response(recv_msg);
4279 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4280 		   && (msg->rsp[1] == IPMI_GET_MSG_CMD)) {
4281 		struct ipmi_channel   *chans;
4282 
4283 		/* It's from the receive queue. */
4284 		chan = msg->rsp[3] & 0xf;
4285 		if (chan >= IPMI_MAX_CHANNELS) {
4286 			/* Invalid channel number */
4287 			requeue = 0;
4288 			goto out;
4289 		}
4290 
4291 		/*
4292 		 * We need to make sure the channels have been initialized.
4293 		 * The channel_handler routine will set the "curr_channel"
4294 		 * equal to or greater than IPMI_MAX_CHANNELS when all the
4295 		 * channels for this interface have been initialized.
4296 		 */
4297 		if (!intf->channels_ready) {
4298 			requeue = 0; /* Throw the message away */
4299 			goto out;
4300 		}
4301 
4302 		chans = READ_ONCE(intf->channel_list)->c;
4303 
4304 		switch (chans[chan].medium) {
4305 		case IPMI_CHANNEL_MEDIUM_IPMB:
4306 			if (msg->rsp[4] & 0x04) {
4307 				/*
4308 				 * It's a response, so find the
4309 				 * requesting message and send it up.
4310 				 */
4311 				requeue = handle_ipmb_get_msg_rsp(intf, msg);
4312 			} else {
4313 				/*
4314 				 * It's a command to the SMS from some other
4315 				 * entity.  Handle that.
4316 				 */
4317 				requeue = handle_ipmb_get_msg_cmd(intf, msg);
4318 			}
4319 			break;
4320 
4321 		case IPMI_CHANNEL_MEDIUM_8023LAN:
4322 		case IPMI_CHANNEL_MEDIUM_ASYNC:
4323 			if (msg->rsp[6] & 0x04) {
4324 				/*
4325 				 * It's a response, so find the
4326 				 * requesting message and send it up.
4327 				 */
4328 				requeue = handle_lan_get_msg_rsp(intf, msg);
4329 			} else {
4330 				/*
4331 				 * It's a command to the SMS from some other
4332 				 * entity.  Handle that.
4333 				 */
4334 				requeue = handle_lan_get_msg_cmd(intf, msg);
4335 			}
4336 			break;
4337 
4338 		default:
4339 			/* Check for OEM Channels.  Clients had better
4340 			   register for these commands. */
4341 			if ((chans[chan].medium >= IPMI_CHANNEL_MEDIUM_OEM_MIN)
4342 			    && (chans[chan].medium
4343 				<= IPMI_CHANNEL_MEDIUM_OEM_MAX)) {
4344 				requeue = handle_oem_get_msg_cmd(intf, msg);
4345 			} else {
4346 				/*
4347 				 * We don't handle the channel type, so just
4348 				 * free the message.
4349 				 */
4350 				requeue = 0;
4351 			}
4352 		}
4353 
4354 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4355 		   && (msg->rsp[1] == IPMI_READ_EVENT_MSG_BUFFER_CMD)) {
4356 		/* It's an asynchronous event. */
4357 		requeue = handle_read_event_rsp(intf, msg);
4358 	} else {
4359 		/* It's a response from the local BMC. */
4360 		requeue = handle_bmc_rsp(intf, msg);
4361 	}
4362 
4363  out:
4364 	return requeue;
4365 }
4366 
4367 /*
4368  * If there are messages in the queue or pretimeouts, handle them.
4369  */
4370 static void handle_new_recv_msgs(ipmi_smi_t intf)
4371 {
4372 	struct ipmi_smi_msg  *smi_msg;
4373 	unsigned long        flags = 0;
4374 	int                  rv;
4375 	int                  run_to_completion = intf->run_to_completion;
4376 
4377 	/* See if any waiting messages need to be processed. */
4378 	if (!run_to_completion)
4379 		spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4380 	while (!list_empty(&intf->waiting_rcv_msgs)) {
4381 		smi_msg = list_entry(intf->waiting_rcv_msgs.next,
4382 				     struct ipmi_smi_msg, link);
4383 		list_del(&smi_msg->link);
4384 		if (!run_to_completion)
4385 			spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
4386 					       flags);
4387 		rv = handle_one_recv_msg(intf, smi_msg);
4388 		if (!run_to_completion)
4389 			spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4390 		if (rv > 0) {
4391 			/*
4392 			 * To preserve message order, quit if we
4393 			 * can't handle a message.  Add the message
4394 			 * back at the head, this is safe because this
4395 			 * tasklet is the only thing that pulls the
4396 			 * messages.
4397 			 */
4398 			list_add(&smi_msg->link, &intf->waiting_rcv_msgs);
4399 			break;
4400 		} else {
4401 			if (rv == 0)
4402 				/* Message handled */
4403 				ipmi_free_smi_msg(smi_msg);
4404 			/* If rv < 0, fatal error, del but don't free. */
4405 		}
4406 	}
4407 	if (!run_to_completion)
4408 		spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock, flags);
4409 
4410 	/*
4411 	 * If the pretimout count is non-zero, decrement one from it and
4412 	 * deliver pretimeouts to all the users.
4413 	 */
4414 	if (atomic_add_unless(&intf->watchdog_pretimeouts_to_deliver, -1, 0)) {
4415 		ipmi_user_t user;
4416 
4417 		rcu_read_lock();
4418 		list_for_each_entry_rcu(user, &intf->users, link) {
4419 			if (user->handler->ipmi_watchdog_pretimeout)
4420 				user->handler->ipmi_watchdog_pretimeout(
4421 					user->handler_data);
4422 		}
4423 		rcu_read_unlock();
4424 	}
4425 }
4426 
4427 static void smi_recv_tasklet(unsigned long val)
4428 {
4429 	unsigned long flags = 0; /* keep us warning-free. */
4430 	ipmi_smi_t intf = (ipmi_smi_t) val;
4431 	int run_to_completion = intf->run_to_completion;
4432 	struct ipmi_smi_msg *newmsg = NULL;
4433 
4434 	/*
4435 	 * Start the next message if available.
4436 	 *
4437 	 * Do this here, not in the actual receiver, because we may deadlock
4438 	 * because the lower layer is allowed to hold locks while calling
4439 	 * message delivery.
4440 	 */
4441 
4442 	rcu_read_lock();
4443 
4444 	if (!run_to_completion)
4445 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
4446 	if (intf->curr_msg == NULL && !intf->in_shutdown) {
4447 		struct list_head *entry = NULL;
4448 
4449 		/* Pick the high priority queue first. */
4450 		if (!list_empty(&intf->hp_xmit_msgs))
4451 			entry = intf->hp_xmit_msgs.next;
4452 		else if (!list_empty(&intf->xmit_msgs))
4453 			entry = intf->xmit_msgs.next;
4454 
4455 		if (entry) {
4456 			list_del(entry);
4457 			newmsg = list_entry(entry, struct ipmi_smi_msg, link);
4458 			intf->curr_msg = newmsg;
4459 		}
4460 	}
4461 	if (!run_to_completion)
4462 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
4463 	if (newmsg)
4464 		intf->handlers->sender(intf->send_info, newmsg);
4465 
4466 	rcu_read_unlock();
4467 
4468 	handle_new_recv_msgs(intf);
4469 }
4470 
4471 /* Handle a new message from the lower layer. */
4472 void ipmi_smi_msg_received(ipmi_smi_t          intf,
4473 			   struct ipmi_smi_msg *msg)
4474 {
4475 	unsigned long flags = 0; /* keep us warning-free. */
4476 	int run_to_completion = intf->run_to_completion;
4477 
4478 	if ((msg->data_size >= 2)
4479 	    && (msg->data[0] == (IPMI_NETFN_APP_REQUEST << 2))
4480 	    && (msg->data[1] == IPMI_SEND_MSG_CMD)
4481 	    && (msg->user_data == NULL)) {
4482 
4483 		if (intf->in_shutdown)
4484 			goto free_msg;
4485 
4486 		/*
4487 		 * This is the local response to a command send, start
4488 		 * the timer for these.  The user_data will not be
4489 		 * NULL if this is a response send, and we will let
4490 		 * response sends just go through.
4491 		 */
4492 
4493 		/*
4494 		 * Check for errors, if we get certain errors (ones
4495 		 * that mean basically we can try again later), we
4496 		 * ignore them and start the timer.  Otherwise we
4497 		 * report the error immediately.
4498 		 */
4499 		if ((msg->rsp_size >= 3) && (msg->rsp[2] != 0)
4500 		    && (msg->rsp[2] != IPMI_NODE_BUSY_ERR)
4501 		    && (msg->rsp[2] != IPMI_LOST_ARBITRATION_ERR)
4502 		    && (msg->rsp[2] != IPMI_BUS_ERR)
4503 		    && (msg->rsp[2] != IPMI_NAK_ON_WRITE_ERR)) {
4504 			int ch = msg->rsp[3] & 0xf;
4505 			struct ipmi_channel *chans;
4506 
4507 			/* Got an error sending the message, handle it. */
4508 
4509 			chans = READ_ONCE(intf->channel_list)->c;
4510 			if ((chans[ch].medium == IPMI_CHANNEL_MEDIUM_8023LAN)
4511 			    || (chans[ch].medium == IPMI_CHANNEL_MEDIUM_ASYNC))
4512 				ipmi_inc_stat(intf, sent_lan_command_errs);
4513 			else
4514 				ipmi_inc_stat(intf, sent_ipmb_command_errs);
4515 			intf_err_seq(intf, msg->msgid, msg->rsp[2]);
4516 		} else
4517 			/* The message was sent, start the timer. */
4518 			intf_start_seq_timer(intf, msg->msgid);
4519 
4520 free_msg:
4521 		ipmi_free_smi_msg(msg);
4522 	} else {
4523 		/*
4524 		 * To preserve message order, we keep a queue and deliver from
4525 		 * a tasklet.
4526 		 */
4527 		if (!run_to_completion)
4528 			spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4529 		list_add_tail(&msg->link, &intf->waiting_rcv_msgs);
4530 		if (!run_to_completion)
4531 			spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
4532 					       flags);
4533 	}
4534 
4535 	if (!run_to_completion)
4536 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
4537 	/*
4538 	 * We can get an asynchronous event or receive message in addition
4539 	 * to commands we send.
4540 	 */
4541 	if (msg == intf->curr_msg)
4542 		intf->curr_msg = NULL;
4543 	if (!run_to_completion)
4544 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
4545 
4546 	if (run_to_completion)
4547 		smi_recv_tasklet((unsigned long) intf);
4548 	else
4549 		tasklet_schedule(&intf->recv_tasklet);
4550 }
4551 EXPORT_SYMBOL(ipmi_smi_msg_received);
4552 
4553 void ipmi_smi_watchdog_pretimeout(ipmi_smi_t intf)
4554 {
4555 	if (intf->in_shutdown)
4556 		return;
4557 
4558 	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 1);
4559 	tasklet_schedule(&intf->recv_tasklet);
4560 }
4561 EXPORT_SYMBOL(ipmi_smi_watchdog_pretimeout);
4562 
4563 static struct ipmi_smi_msg *
4564 smi_from_recv_msg(ipmi_smi_t intf, struct ipmi_recv_msg *recv_msg,
4565 		  unsigned char seq, long seqid)
4566 {
4567 	struct ipmi_smi_msg *smi_msg = ipmi_alloc_smi_msg();
4568 	if (!smi_msg)
4569 		/*
4570 		 * If we can't allocate the message, then just return, we
4571 		 * get 4 retries, so this should be ok.
4572 		 */
4573 		return NULL;
4574 
4575 	memcpy(smi_msg->data, recv_msg->msg.data, recv_msg->msg.data_len);
4576 	smi_msg->data_size = recv_msg->msg.data_len;
4577 	smi_msg->msgid = STORE_SEQ_IN_MSGID(seq, seqid);
4578 
4579 #ifdef DEBUG_MSGING
4580 	{
4581 		int m;
4582 		printk("Resend: ");
4583 		for (m = 0; m < smi_msg->data_size; m++)
4584 			printk(" %2.2x", smi_msg->data[m]);
4585 		printk("\n");
4586 	}
4587 #endif
4588 	return smi_msg;
4589 }
4590 
4591 static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent,
4592 			      struct list_head *timeouts,
4593 			      unsigned long timeout_period,
4594 			      int slot, unsigned long *flags,
4595 			      unsigned int *waiting_msgs)
4596 {
4597 	struct ipmi_recv_msg     *msg;
4598 	const struct ipmi_smi_handlers *handlers;
4599 
4600 	if (intf->in_shutdown)
4601 		return;
4602 
4603 	if (!ent->inuse)
4604 		return;
4605 
4606 	if (timeout_period < ent->timeout) {
4607 		ent->timeout -= timeout_period;
4608 		(*waiting_msgs)++;
4609 		return;
4610 	}
4611 
4612 	if (ent->retries_left == 0) {
4613 		/* The message has used all its retries. */
4614 		ent->inuse = 0;
4615 		msg = ent->recv_msg;
4616 		list_add_tail(&msg->link, timeouts);
4617 		if (ent->broadcast)
4618 			ipmi_inc_stat(intf, timed_out_ipmb_broadcasts);
4619 		else if (is_lan_addr(&ent->recv_msg->addr))
4620 			ipmi_inc_stat(intf, timed_out_lan_commands);
4621 		else
4622 			ipmi_inc_stat(intf, timed_out_ipmb_commands);
4623 	} else {
4624 		struct ipmi_smi_msg *smi_msg;
4625 		/* More retries, send again. */
4626 
4627 		(*waiting_msgs)++;
4628 
4629 		/*
4630 		 * Start with the max timer, set to normal timer after
4631 		 * the message is sent.
4632 		 */
4633 		ent->timeout = MAX_MSG_TIMEOUT;
4634 		ent->retries_left--;
4635 		smi_msg = smi_from_recv_msg(intf, ent->recv_msg, slot,
4636 					    ent->seqid);
4637 		if (!smi_msg) {
4638 			if (is_lan_addr(&ent->recv_msg->addr))
4639 				ipmi_inc_stat(intf,
4640 					      dropped_rexmit_lan_commands);
4641 			else
4642 				ipmi_inc_stat(intf,
4643 					      dropped_rexmit_ipmb_commands);
4644 			return;
4645 		}
4646 
4647 		spin_unlock_irqrestore(&intf->seq_lock, *flags);
4648 
4649 		/*
4650 		 * Send the new message.  We send with a zero
4651 		 * priority.  It timed out, I doubt time is that
4652 		 * critical now, and high priority messages are really
4653 		 * only for messages to the local MC, which don't get
4654 		 * resent.
4655 		 */
4656 		handlers = intf->handlers;
4657 		if (handlers) {
4658 			if (is_lan_addr(&ent->recv_msg->addr))
4659 				ipmi_inc_stat(intf,
4660 					      retransmitted_lan_commands);
4661 			else
4662 				ipmi_inc_stat(intf,
4663 					      retransmitted_ipmb_commands);
4664 
4665 			smi_send(intf, handlers, smi_msg, 0);
4666 		} else
4667 			ipmi_free_smi_msg(smi_msg);
4668 
4669 		spin_lock_irqsave(&intf->seq_lock, *flags);
4670 	}
4671 }
4672 
4673 static unsigned int ipmi_timeout_handler(ipmi_smi_t intf,
4674 					 unsigned long timeout_period)
4675 {
4676 	struct list_head     timeouts;
4677 	struct ipmi_recv_msg *msg, *msg2;
4678 	unsigned long        flags;
4679 	int                  i;
4680 	unsigned int         waiting_msgs = 0;
4681 
4682 	if (!intf->bmc_registered) {
4683 		kref_get(&intf->refcount);
4684 		if (!schedule_work(&intf->bmc_reg_work)) {
4685 			kref_put(&intf->refcount, intf_free);
4686 			waiting_msgs++;
4687 		}
4688 	}
4689 
4690 	/*
4691 	 * Go through the seq table and find any messages that
4692 	 * have timed out, putting them in the timeouts
4693 	 * list.
4694 	 */
4695 	INIT_LIST_HEAD(&timeouts);
4696 	spin_lock_irqsave(&intf->seq_lock, flags);
4697 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++)
4698 		check_msg_timeout(intf, &(intf->seq_table[i]),
4699 				  &timeouts, timeout_period, i,
4700 				  &flags, &waiting_msgs);
4701 	spin_unlock_irqrestore(&intf->seq_lock, flags);
4702 
4703 	list_for_each_entry_safe(msg, msg2, &timeouts, link)
4704 		deliver_err_response(msg, IPMI_TIMEOUT_COMPLETION_CODE);
4705 
4706 	/*
4707 	 * Maintenance mode handling.  Check the timeout
4708 	 * optimistically before we claim the lock.  It may
4709 	 * mean a timeout gets missed occasionally, but that
4710 	 * only means the timeout gets extended by one period
4711 	 * in that case.  No big deal, and it avoids the lock
4712 	 * most of the time.
4713 	 */
4714 	if (intf->auto_maintenance_timeout > 0) {
4715 		spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
4716 		if (intf->auto_maintenance_timeout > 0) {
4717 			intf->auto_maintenance_timeout
4718 				-= timeout_period;
4719 			if (!intf->maintenance_mode
4720 			    && (intf->auto_maintenance_timeout <= 0)) {
4721 				intf->maintenance_mode_enable = false;
4722 				maintenance_mode_update(intf);
4723 			}
4724 		}
4725 		spin_unlock_irqrestore(&intf->maintenance_mode_lock,
4726 				       flags);
4727 	}
4728 
4729 	tasklet_schedule(&intf->recv_tasklet);
4730 
4731 	return waiting_msgs;
4732 }
4733 
4734 static void ipmi_request_event(ipmi_smi_t intf)
4735 {
4736 	/* No event requests when in maintenance mode. */
4737 	if (intf->maintenance_mode_enable)
4738 		return;
4739 
4740 	if (!intf->in_shutdown)
4741 		intf->handlers->request_events(intf->send_info);
4742 }
4743 
4744 static struct timer_list ipmi_timer;
4745 
4746 static atomic_t stop_operation;
4747 
4748 static void ipmi_timeout(struct timer_list *unused)
4749 {
4750 	ipmi_smi_t intf;
4751 	int nt = 0;
4752 
4753 	if (atomic_read(&stop_operation))
4754 		return;
4755 
4756 	rcu_read_lock();
4757 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
4758 		int lnt = 0;
4759 
4760 		if (atomic_read(&intf->event_waiters)) {
4761 			intf->ticks_to_req_ev--;
4762 			if (intf->ticks_to_req_ev == 0) {
4763 				ipmi_request_event(intf);
4764 				intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
4765 			}
4766 			lnt++;
4767 		}
4768 
4769 		lnt += ipmi_timeout_handler(intf, IPMI_TIMEOUT_TIME);
4770 
4771 		lnt = !!lnt;
4772 		if (lnt != intf->last_needs_timer &&
4773 					intf->handlers->set_need_watch)
4774 			intf->handlers->set_need_watch(intf->send_info, lnt);
4775 		intf->last_needs_timer = lnt;
4776 
4777 		nt += lnt;
4778 	}
4779 	rcu_read_unlock();
4780 
4781 	if (nt)
4782 		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
4783 }
4784 
4785 static void need_waiter(ipmi_smi_t intf)
4786 {
4787 	/* Racy, but worst case we start the timer twice. */
4788 	if (!timer_pending(&ipmi_timer))
4789 		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
4790 }
4791 
4792 static atomic_t smi_msg_inuse_count = ATOMIC_INIT(0);
4793 static atomic_t recv_msg_inuse_count = ATOMIC_INIT(0);
4794 
4795 static void free_smi_msg(struct ipmi_smi_msg *msg)
4796 {
4797 	atomic_dec(&smi_msg_inuse_count);
4798 	kfree(msg);
4799 }
4800 
4801 struct ipmi_smi_msg *ipmi_alloc_smi_msg(void)
4802 {
4803 	struct ipmi_smi_msg *rv;
4804 	rv = kmalloc(sizeof(struct ipmi_smi_msg), GFP_ATOMIC);
4805 	if (rv) {
4806 		rv->done = free_smi_msg;
4807 		rv->user_data = NULL;
4808 		atomic_inc(&smi_msg_inuse_count);
4809 	}
4810 	return rv;
4811 }
4812 EXPORT_SYMBOL(ipmi_alloc_smi_msg);
4813 
4814 static void free_recv_msg(struct ipmi_recv_msg *msg)
4815 {
4816 	atomic_dec(&recv_msg_inuse_count);
4817 	kfree(msg);
4818 }
4819 
4820 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void)
4821 {
4822 	struct ipmi_recv_msg *rv;
4823 
4824 	rv = kmalloc(sizeof(struct ipmi_recv_msg), GFP_ATOMIC);
4825 	if (rv) {
4826 		rv->user = NULL;
4827 		rv->done = free_recv_msg;
4828 		atomic_inc(&recv_msg_inuse_count);
4829 	}
4830 	return rv;
4831 }
4832 
4833 void ipmi_free_recv_msg(struct ipmi_recv_msg *msg)
4834 {
4835 	if (msg->user)
4836 		kref_put(&msg->user->refcount, free_user);
4837 	msg->done(msg);
4838 }
4839 EXPORT_SYMBOL(ipmi_free_recv_msg);
4840 
4841 static atomic_t panic_done_count = ATOMIC_INIT(0);
4842 
4843 static void dummy_smi_done_handler(struct ipmi_smi_msg *msg)
4844 {
4845 	atomic_dec(&panic_done_count);
4846 }
4847 
4848 static void dummy_recv_done_handler(struct ipmi_recv_msg *msg)
4849 {
4850 	atomic_dec(&panic_done_count);
4851 }
4852 
4853 /*
4854  * Inside a panic, send a message and wait for a response.
4855  */
4856 static void ipmi_panic_request_and_wait(ipmi_smi_t           intf,
4857 					struct ipmi_addr     *addr,
4858 					struct kernel_ipmi_msg *msg)
4859 {
4860 	struct ipmi_smi_msg  smi_msg;
4861 	struct ipmi_recv_msg recv_msg;
4862 	int rv;
4863 
4864 	smi_msg.done = dummy_smi_done_handler;
4865 	recv_msg.done = dummy_recv_done_handler;
4866 	atomic_add(2, &panic_done_count);
4867 	rv = i_ipmi_request(NULL,
4868 			    intf,
4869 			    addr,
4870 			    0,
4871 			    msg,
4872 			    intf,
4873 			    &smi_msg,
4874 			    &recv_msg,
4875 			    0,
4876 			    intf->addrinfo[0].address,
4877 			    intf->addrinfo[0].lun,
4878 			    0, 1); /* Don't retry, and don't wait. */
4879 	if (rv)
4880 		atomic_sub(2, &panic_done_count);
4881 	else if (intf->handlers->flush_messages)
4882 		intf->handlers->flush_messages(intf->send_info);
4883 
4884 	while (atomic_read(&panic_done_count) != 0)
4885 		ipmi_poll(intf);
4886 }
4887 
4888 static void event_receiver_fetcher(ipmi_smi_t intf, struct ipmi_recv_msg *msg)
4889 {
4890 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
4891 	    && (msg->msg.netfn == IPMI_NETFN_SENSOR_EVENT_RESPONSE)
4892 	    && (msg->msg.cmd == IPMI_GET_EVENT_RECEIVER_CMD)
4893 	    && (msg->msg.data[0] == IPMI_CC_NO_ERROR)) {
4894 		/* A get event receiver command, save it. */
4895 		intf->event_receiver = msg->msg.data[1];
4896 		intf->event_receiver_lun = msg->msg.data[2] & 0x3;
4897 	}
4898 }
4899 
4900 static void device_id_fetcher(ipmi_smi_t intf, struct ipmi_recv_msg *msg)
4901 {
4902 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
4903 	    && (msg->msg.netfn == IPMI_NETFN_APP_RESPONSE)
4904 	    && (msg->msg.cmd == IPMI_GET_DEVICE_ID_CMD)
4905 	    && (msg->msg.data[0] == IPMI_CC_NO_ERROR)) {
4906 		/*
4907 		 * A get device id command, save if we are an event
4908 		 * receiver or generator.
4909 		 */
4910 		intf->local_sel_device = (msg->msg.data[6] >> 2) & 1;
4911 		intf->local_event_generator = (msg->msg.data[6] >> 5) & 1;
4912 	}
4913 }
4914 
4915 static void send_panic_events(char *str)
4916 {
4917 	struct kernel_ipmi_msg            msg;
4918 	ipmi_smi_t                        intf;
4919 	unsigned char                     data[16];
4920 	struct ipmi_system_interface_addr *si;
4921 	struct ipmi_addr                  addr;
4922 
4923 	if (ipmi_send_panic_event == IPMI_SEND_PANIC_EVENT_NONE)
4924 		return;
4925 
4926 	si = (struct ipmi_system_interface_addr *) &addr;
4927 	si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4928 	si->channel = IPMI_BMC_CHANNEL;
4929 	si->lun = 0;
4930 
4931 	/* Fill in an event telling that we have failed. */
4932 	msg.netfn = 0x04; /* Sensor or Event. */
4933 	msg.cmd = 2; /* Platform event command. */
4934 	msg.data = data;
4935 	msg.data_len = 8;
4936 	data[0] = 0x41; /* Kernel generator ID, IPMI table 5-4 */
4937 	data[1] = 0x03; /* This is for IPMI 1.0. */
4938 	data[2] = 0x20; /* OS Critical Stop, IPMI table 36-3 */
4939 	data[4] = 0x6f; /* Sensor specific, IPMI table 36-1 */
4940 	data[5] = 0xa1; /* Runtime stop OEM bytes 2 & 3. */
4941 
4942 	/*
4943 	 * Put a few breadcrumbs in.  Hopefully later we can add more things
4944 	 * to make the panic events more useful.
4945 	 */
4946 	if (str) {
4947 		data[3] = str[0];
4948 		data[6] = str[1];
4949 		data[7] = str[2];
4950 	}
4951 
4952 	/* For every registered interface, send the event. */
4953 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
4954 		if (!intf->handlers || !intf->handlers->poll)
4955 			/* Interface is not ready or can't run at panic time. */
4956 			continue;
4957 
4958 		/* Send the event announcing the panic. */
4959 		ipmi_panic_request_and_wait(intf, &addr, &msg);
4960 	}
4961 
4962 	/*
4963 	 * On every interface, dump a bunch of OEM event holding the
4964 	 * string.
4965 	 */
4966 	if (ipmi_send_panic_event != IPMI_SEND_PANIC_EVENT_STRING || !str)
4967 		return;
4968 
4969 	/* For every registered interface, send the event. */
4970 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
4971 		char                  *p = str;
4972 		struct ipmi_ipmb_addr *ipmb;
4973 		int                   j;
4974 
4975 		if (intf->intf_num == -1)
4976 			/* Interface was not ready yet. */
4977 			continue;
4978 
4979 		/*
4980 		 * intf_num is used as an marker to tell if the
4981 		 * interface is valid.  Thus we need a read barrier to
4982 		 * make sure data fetched before checking intf_num
4983 		 * won't be used.
4984 		 */
4985 		smp_rmb();
4986 
4987 		/*
4988 		 * First job here is to figure out where to send the
4989 		 * OEM events.  There's no way in IPMI to send OEM
4990 		 * events using an event send command, so we have to
4991 		 * find the SEL to put them in and stick them in
4992 		 * there.
4993 		 */
4994 
4995 		/* Get capabilities from the get device id. */
4996 		intf->local_sel_device = 0;
4997 		intf->local_event_generator = 0;
4998 		intf->event_receiver = 0;
4999 
5000 		/* Request the device info from the local MC. */
5001 		msg.netfn = IPMI_NETFN_APP_REQUEST;
5002 		msg.cmd = IPMI_GET_DEVICE_ID_CMD;
5003 		msg.data = NULL;
5004 		msg.data_len = 0;
5005 		intf->null_user_handler = device_id_fetcher;
5006 		ipmi_panic_request_and_wait(intf, &addr, &msg);
5007 
5008 		if (intf->local_event_generator) {
5009 			/* Request the event receiver from the local MC. */
5010 			msg.netfn = IPMI_NETFN_SENSOR_EVENT_REQUEST;
5011 			msg.cmd = IPMI_GET_EVENT_RECEIVER_CMD;
5012 			msg.data = NULL;
5013 			msg.data_len = 0;
5014 			intf->null_user_handler = event_receiver_fetcher;
5015 			ipmi_panic_request_and_wait(intf, &addr, &msg);
5016 		}
5017 		intf->null_user_handler = NULL;
5018 
5019 		/*
5020 		 * Validate the event receiver.  The low bit must not
5021 		 * be 1 (it must be a valid IPMB address), it cannot
5022 		 * be zero, and it must not be my address.
5023 		 */
5024 		if (((intf->event_receiver & 1) == 0)
5025 		    && (intf->event_receiver != 0)
5026 		    && (intf->event_receiver != intf->addrinfo[0].address)) {
5027 			/*
5028 			 * The event receiver is valid, send an IPMB
5029 			 * message.
5030 			 */
5031 			ipmb = (struct ipmi_ipmb_addr *) &addr;
5032 			ipmb->addr_type = IPMI_IPMB_ADDR_TYPE;
5033 			ipmb->channel = 0; /* FIXME - is this right? */
5034 			ipmb->lun = intf->event_receiver_lun;
5035 			ipmb->slave_addr = intf->event_receiver;
5036 		} else if (intf->local_sel_device) {
5037 			/*
5038 			 * The event receiver was not valid (or was
5039 			 * me), but I am an SEL device, just dump it
5040 			 * in my SEL.
5041 			 */
5042 			si = (struct ipmi_system_interface_addr *) &addr;
5043 			si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
5044 			si->channel = IPMI_BMC_CHANNEL;
5045 			si->lun = 0;
5046 		} else
5047 			continue; /* No where to send the event. */
5048 
5049 		msg.netfn = IPMI_NETFN_STORAGE_REQUEST; /* Storage. */
5050 		msg.cmd = IPMI_ADD_SEL_ENTRY_CMD;
5051 		msg.data = data;
5052 		msg.data_len = 16;
5053 
5054 		j = 0;
5055 		while (*p) {
5056 			int size = strlen(p);
5057 
5058 			if (size > 11)
5059 				size = 11;
5060 			data[0] = 0;
5061 			data[1] = 0;
5062 			data[2] = 0xf0; /* OEM event without timestamp. */
5063 			data[3] = intf->addrinfo[0].address;
5064 			data[4] = j++; /* sequence # */
5065 			/*
5066 			 * Always give 11 bytes, so strncpy will fill
5067 			 * it with zeroes for me.
5068 			 */
5069 			strncpy(data+5, p, 11);
5070 			p += size;
5071 
5072 			ipmi_panic_request_and_wait(intf, &addr, &msg);
5073 		}
5074 	}
5075 }
5076 
5077 static int has_panicked;
5078 
5079 static int panic_event(struct notifier_block *this,
5080 		       unsigned long         event,
5081 		       void                  *ptr)
5082 {
5083 	ipmi_smi_t intf;
5084 
5085 	if (has_panicked)
5086 		return NOTIFY_DONE;
5087 	has_panicked = 1;
5088 
5089 	/* For every registered interface, set it to run to completion. */
5090 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
5091 		if (!intf->handlers)
5092 			/* Interface is not ready. */
5093 			continue;
5094 
5095 		/*
5096 		 * If we were interrupted while locking xmit_msgs_lock or
5097 		 * waiting_rcv_msgs_lock, the corresponding list may be
5098 		 * corrupted.  In this case, drop items on the list for
5099 		 * the safety.
5100 		 */
5101 		if (!spin_trylock(&intf->xmit_msgs_lock)) {
5102 			INIT_LIST_HEAD(&intf->xmit_msgs);
5103 			INIT_LIST_HEAD(&intf->hp_xmit_msgs);
5104 		} else
5105 			spin_unlock(&intf->xmit_msgs_lock);
5106 
5107 		if (!spin_trylock(&intf->waiting_rcv_msgs_lock))
5108 			INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
5109 		else
5110 			spin_unlock(&intf->waiting_rcv_msgs_lock);
5111 
5112 		intf->run_to_completion = 1;
5113 		if (intf->handlers->set_run_to_completion)
5114 			intf->handlers->set_run_to_completion(intf->send_info,
5115 							      1);
5116 	}
5117 
5118 	send_panic_events(ptr);
5119 
5120 	return NOTIFY_DONE;
5121 }
5122 
5123 static struct notifier_block panic_block = {
5124 	.notifier_call	= panic_event,
5125 	.next		= NULL,
5126 	.priority	= 200	/* priority: INT_MAX >= x >= 0 */
5127 };
5128 
5129 static int ipmi_init_msghandler(void)
5130 {
5131 	int rv;
5132 
5133 	if (initialized)
5134 		return 0;
5135 
5136 	rv = driver_register(&ipmidriver.driver);
5137 	if (rv) {
5138 		pr_err(PFX "Could not register IPMI driver\n");
5139 		return rv;
5140 	}
5141 
5142 	pr_info("ipmi message handler version " IPMI_DRIVER_VERSION "\n");
5143 
5144 #ifdef CONFIG_IPMI_PROC_INTERFACE
5145 	proc_ipmi_root = proc_mkdir("ipmi", NULL);
5146 	if (!proc_ipmi_root) {
5147 	    pr_err(PFX "Unable to create IPMI proc dir");
5148 	    driver_unregister(&ipmidriver.driver);
5149 	    return -ENOMEM;
5150 	}
5151 
5152 #endif /* CONFIG_IPMI_PROC_INTERFACE */
5153 
5154 	timer_setup(&ipmi_timer, ipmi_timeout, 0);
5155 	mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
5156 
5157 	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
5158 
5159 	initialized = 1;
5160 
5161 	return 0;
5162 }
5163 
5164 static int __init ipmi_init_msghandler_mod(void)
5165 {
5166 	ipmi_init_msghandler();
5167 	return 0;
5168 }
5169 
5170 static void __exit cleanup_ipmi(void)
5171 {
5172 	int count;
5173 
5174 	if (!initialized)
5175 		return;
5176 
5177 	atomic_notifier_chain_unregister(&panic_notifier_list, &panic_block);
5178 
5179 	/*
5180 	 * This can't be called if any interfaces exist, so no worry
5181 	 * about shutting down the interfaces.
5182 	 */
5183 
5184 	/*
5185 	 * Tell the timer to stop, then wait for it to stop.  This
5186 	 * avoids problems with race conditions removing the timer
5187 	 * here.
5188 	 */
5189 	atomic_inc(&stop_operation);
5190 	del_timer_sync(&ipmi_timer);
5191 
5192 #ifdef CONFIG_IPMI_PROC_INTERFACE
5193 	proc_remove(proc_ipmi_root);
5194 #endif /* CONFIG_IPMI_PROC_INTERFACE */
5195 
5196 	driver_unregister(&ipmidriver.driver);
5197 
5198 	initialized = 0;
5199 
5200 	/* Check for buffer leaks. */
5201 	count = atomic_read(&smi_msg_inuse_count);
5202 	if (count != 0)
5203 		pr_warn(PFX "SMI message count %d at exit\n", count);
5204 	count = atomic_read(&recv_msg_inuse_count);
5205 	if (count != 0)
5206 		pr_warn(PFX "recv message count %d at exit\n", count);
5207 }
5208 module_exit(cleanup_ipmi);
5209 
5210 module_init(ipmi_init_msghandler_mod);
5211 MODULE_LICENSE("GPL");
5212 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
5213 MODULE_DESCRIPTION("Incoming and outgoing message routing for an IPMI"
5214 		   " interface.");
5215 MODULE_VERSION(IPMI_DRIVER_VERSION);
5216 MODULE_SOFTDEP("post: ipmi_devintf");
5217