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