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