xref: /linux/drivers/char/ipmi/ipmi_msghandler.c (revision 9e91f8a6c8688e27f4ccce7db457da87d6458836)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * ipmi_msghandler.c
4  *
5  * Incoming and outgoing message routing for an IPMI interface.
6  *
7  * Author: MontaVista Software, Inc.
8  *         Corey Minyard <minyard@mvista.com>
9  *         source@mvista.com
10  *
11  * Copyright 2002 MontaVista Software Inc.
12  */
13 
14 #define pr_fmt(fmt) "IPMI message handler: " fmt
15 #define dev_fmt(fmt) pr_fmt(fmt)
16 
17 #include <linux/module.h>
18 #include <linux/errno.h>
19 #include <linux/panic_notifier.h>
20 #include <linux/poll.h>
21 #include <linux/sched.h>
22 #include <linux/seq_file.h>
23 #include <linux/spinlock.h>
24 #include <linux/mutex.h>
25 #include <linux/slab.h>
26 #include <linux/ipmi.h>
27 #include <linux/ipmi_smi.h>
28 #include <linux/notifier.h>
29 #include <linux/init.h>
30 #include <linux/proc_fs.h>
31 #include <linux/rcupdate.h>
32 #include <linux/interrupt.h>
33 #include <linux/moduleparam.h>
34 #include <linux/workqueue.h>
35 #include <linux/uuid.h>
36 #include <linux/nospec.h>
37 #include <linux/vmalloc.h>
38 #include <linux/delay.h>
39 
40 #define IPMI_DRIVER_VERSION "39.2"
41 
42 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void);
43 static int ipmi_init_msghandler(void);
44 static void smi_work(struct work_struct *t);
45 static void handle_new_recv_msgs(struct ipmi_smi *intf);
46 static void need_waiter(struct ipmi_smi *intf);
47 static int handle_one_recv_msg(struct ipmi_smi *intf,
48 			       struct ipmi_smi_msg *msg);
49 
50 static bool initialized;
51 static bool drvregistered;
52 
53 /* Numbers in this enumerator should be mapped to ipmi_panic_event_str */
54 enum ipmi_panic_event_op {
55 	IPMI_SEND_PANIC_EVENT_NONE,
56 	IPMI_SEND_PANIC_EVENT,
57 	IPMI_SEND_PANIC_EVENT_STRING,
58 	IPMI_SEND_PANIC_EVENT_MAX
59 };
60 
61 /* Indices in this array should be mapped to enum ipmi_panic_event_op */
62 static const char *const ipmi_panic_event_str[] = { "none", "event", "string", NULL };
63 
64 #ifdef CONFIG_IPMI_PANIC_STRING
65 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT_STRING
66 #elif defined(CONFIG_IPMI_PANIC_EVENT)
67 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT
68 #else
69 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT_NONE
70 #endif
71 
72 static enum ipmi_panic_event_op ipmi_send_panic_event = IPMI_PANIC_DEFAULT;
73 
74 static int panic_op_write_handler(const char *val,
75 				  const struct kernel_param *kp)
76 {
77 	char valcp[16];
78 	int e;
79 
80 	strscpy(valcp, val, sizeof(valcp));
81 	e = match_string(ipmi_panic_event_str, -1, strstrip(valcp));
82 	if (e < 0)
83 		return e;
84 
85 	ipmi_send_panic_event = e;
86 	return 0;
87 }
88 
89 static int panic_op_read_handler(char *buffer, const struct kernel_param *kp)
90 {
91 	const char *event_str;
92 
93 	if (ipmi_send_panic_event >= IPMI_SEND_PANIC_EVENT_MAX)
94 		event_str = "???";
95 	else
96 		event_str = ipmi_panic_event_str[ipmi_send_panic_event];
97 
98 	return sprintf(buffer, "%s\n", event_str);
99 }
100 
101 static const struct kernel_param_ops panic_op_ops = {
102 	.set = panic_op_write_handler,
103 	.get = panic_op_read_handler
104 };
105 module_param_cb(panic_op, &panic_op_ops, NULL, 0600);
106 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.");
107 
108 
109 #define MAX_EVENTS_IN_QUEUE	25
110 
111 /* Remain in auto-maintenance mode for this amount of time (in ms). */
112 static unsigned long maintenance_mode_timeout_ms = 30000;
113 module_param(maintenance_mode_timeout_ms, ulong, 0644);
114 MODULE_PARM_DESC(maintenance_mode_timeout_ms,
115 		 "The time (milliseconds) after the last maintenance message that the connection stays in maintenance mode.");
116 
117 /*
118  * Don't let a message sit in a queue forever, always time it with at lest
119  * the max message timer.  This is in milliseconds.
120  */
121 #define MAX_MSG_TIMEOUT		60000
122 
123 /*
124  * Timeout times below are in milliseconds, and are done off a 1
125  * second timer.  So setting the value to 1000 would mean anything
126  * between 0 and 1000ms.  So really the only reasonable minimum
127  * setting it 2000ms, which is between 1 and 2 seconds.
128  */
129 
130 /* The default timeout for message retries. */
131 static unsigned long default_retry_ms = 2000;
132 module_param(default_retry_ms, ulong, 0644);
133 MODULE_PARM_DESC(default_retry_ms,
134 		 "The time (milliseconds) between retry sends");
135 
136 /* The default timeout for maintenance mode message retries. */
137 static unsigned long default_maintenance_retry_ms = 3000;
138 module_param(default_maintenance_retry_ms, ulong, 0644);
139 MODULE_PARM_DESC(default_maintenance_retry_ms,
140 		 "The time (milliseconds) between retry sends in maintenance mode");
141 
142 /* The default maximum number of retries */
143 static unsigned int default_max_retries = 4;
144 module_param(default_max_retries, uint, 0644);
145 MODULE_PARM_DESC(default_max_retries,
146 		 "The time (milliseconds) between retry sends in maintenance mode");
147 
148 /* The default maximum number of users that may register. */
149 static unsigned int max_users = 30;
150 module_param(max_users, uint, 0644);
151 MODULE_PARM_DESC(max_users,
152 		 "The most users that may use the IPMI stack at one time.");
153 
154 /* The default maximum number of message a user may have outstanding. */
155 static unsigned int max_msgs_per_user = 100;
156 module_param(max_msgs_per_user, uint, 0644);
157 MODULE_PARM_DESC(max_msgs_per_user,
158 		 "The most message a user may have outstanding.");
159 
160 /* Call every ~1000 ms. */
161 #define IPMI_TIMEOUT_TIME	1000
162 
163 /* How many jiffies does it take to get to the timeout time. */
164 #define IPMI_TIMEOUT_JIFFIES	((IPMI_TIMEOUT_TIME * HZ) / 1000)
165 
166 /*
167  * Request events from the queue every second (this is the number of
168  * IPMI_TIMEOUT_TIMES between event requests).  Hopefully, in the
169  * future, IPMI will add a way to know immediately if an event is in
170  * the queue and this silliness can go away.
171  */
172 #define IPMI_REQUEST_EV_TIME	(1000 / (IPMI_TIMEOUT_TIME))
173 
174 /* How long should we cache dynamic device IDs? */
175 #define IPMI_DYN_DEV_ID_EXPIRY	(10 * HZ)
176 
177 /*
178  * The main "user" data structure.
179  */
180 struct ipmi_user {
181 	struct list_head link;
182 
183 	struct kref refcount;
184 	refcount_t destroyed;
185 
186 	/* The upper layer that handles receive messages. */
187 	const struct ipmi_user_hndl *handler;
188 	void             *handler_data;
189 
190 	/* The interface this user is bound to. */
191 	struct ipmi_smi *intf;
192 
193 	/* Does this interface receive IPMI events? */
194 	bool gets_events;
195 
196 	atomic_t nr_msgs;
197 };
198 
199 static void free_ipmi_user(struct kref *ref)
200 {
201 	struct ipmi_user *user = container_of(ref, struct ipmi_user, refcount);
202 
203 	vfree(user);
204 }
205 
206 static void release_ipmi_user(struct ipmi_user *user)
207 {
208 	kref_put(&user->refcount, free_ipmi_user);
209 }
210 
211 static struct ipmi_user *acquire_ipmi_user(struct ipmi_user *user)
212 {
213 	if (!kref_get_unless_zero(&user->refcount))
214 		return NULL;
215 	return user;
216 }
217 
218 struct cmd_rcvr {
219 	struct list_head link;
220 
221 	struct ipmi_user *user;
222 	unsigned char netfn;
223 	unsigned char cmd;
224 	unsigned int  chans;
225 
226 	/*
227 	 * This is used to form a linked lised during mass deletion.
228 	 * Since this is in an RCU list, we cannot use the link above
229 	 * or change any data until the RCU period completes.  So we
230 	 * use this next variable during mass deletion so we can have
231 	 * a list and don't have to wait and restart the search on
232 	 * every individual deletion of a command.
233 	 */
234 	struct cmd_rcvr *next;
235 };
236 
237 struct seq_table {
238 	unsigned int         inuse : 1;
239 	unsigned int         broadcast : 1;
240 
241 	unsigned long        timeout;
242 	unsigned long        orig_timeout;
243 	unsigned int         retries_left;
244 
245 	/*
246 	 * To verify on an incoming send message response that this is
247 	 * the message that the response is for, we keep a sequence id
248 	 * and increment it every time we send a message.
249 	 */
250 	long                 seqid;
251 
252 	/*
253 	 * This is held so we can properly respond to the message on a
254 	 * timeout, and it is used to hold the temporary data for
255 	 * retransmission, too.
256 	 */
257 	struct ipmi_recv_msg *recv_msg;
258 };
259 
260 /*
261  * Store the information in a msgid (long) to allow us to find a
262  * sequence table entry from the msgid.
263  */
264 #define STORE_SEQ_IN_MSGID(seq, seqid) \
265 	((((seq) & 0x3f) << 26) | ((seqid) & 0x3ffffff))
266 
267 #define GET_SEQ_FROM_MSGID(msgid, seq, seqid) \
268 	do {								\
269 		seq = (((msgid) >> 26) & 0x3f);				\
270 		seqid = ((msgid) & 0x3ffffff);				\
271 	} while (0)
272 
273 #define NEXT_SEQID(seqid) (((seqid) + 1) & 0x3ffffff)
274 
275 #define IPMI_MAX_CHANNELS       16
276 struct ipmi_channel {
277 	unsigned char medium;
278 	unsigned char protocol;
279 };
280 
281 struct ipmi_channel_set {
282 	struct ipmi_channel c[IPMI_MAX_CHANNELS];
283 };
284 
285 struct ipmi_my_addrinfo {
286 	/*
287 	 * My slave address.  This is initialized to IPMI_BMC_SLAVE_ADDR,
288 	 * but may be changed by the user.
289 	 */
290 	unsigned char address;
291 
292 	/*
293 	 * My LUN.  This should generally stay the SMS LUN, but just in
294 	 * case...
295 	 */
296 	unsigned char lun;
297 };
298 
299 /*
300  * Note that the product id, manufacturer id, guid, and device id are
301  * immutable in this structure, so dyn_mutex is not required for
302  * accessing those.  If those change on a BMC, a new BMC is allocated.
303  */
304 struct bmc_device {
305 	struct platform_device pdev;
306 	struct list_head       intfs; /* Interfaces on this BMC. */
307 	struct ipmi_device_id  id;
308 	struct ipmi_device_id  fetch_id;
309 	int                    dyn_id_set;
310 	unsigned long          dyn_id_expiry;
311 	struct mutex           dyn_mutex; /* Protects id, intfs, & dyn* */
312 	guid_t                 guid;
313 	guid_t                 fetch_guid;
314 	int                    dyn_guid_set;
315 	struct kref	       usecount;
316 	struct work_struct     remove_work;
317 	unsigned char	       cc; /* completion code */
318 };
319 #define to_bmc_device(x) container_of((x), struct bmc_device, pdev.dev)
320 
321 static struct workqueue_struct *bmc_remove_work_wq;
322 
323 static int bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
324 			     struct ipmi_device_id *id,
325 			     bool *guid_set, guid_t *guid);
326 
327 /*
328  * Various statistics for IPMI, these index stats[] in the ipmi_smi
329  * structure.
330  */
331 enum ipmi_stat_indexes {
332 	/* Commands we got from the user that were invalid. */
333 	IPMI_STAT_sent_invalid_commands = 0,
334 
335 	/* Commands we sent to the MC. */
336 	IPMI_STAT_sent_local_commands,
337 
338 	/* Responses from the MC that were delivered to a user. */
339 	IPMI_STAT_handled_local_responses,
340 
341 	/* Responses from the MC that were not delivered to a user. */
342 	IPMI_STAT_unhandled_local_responses,
343 
344 	/* Commands we sent out to the IPMB bus. */
345 	IPMI_STAT_sent_ipmb_commands,
346 
347 	/* Commands sent on the IPMB that had errors on the SEND CMD */
348 	IPMI_STAT_sent_ipmb_command_errs,
349 
350 	/* Each retransmit increments this count. */
351 	IPMI_STAT_retransmitted_ipmb_commands,
352 
353 	/*
354 	 * When a message times out (runs out of retransmits) this is
355 	 * incremented.
356 	 */
357 	IPMI_STAT_timed_out_ipmb_commands,
358 
359 	/*
360 	 * This is like above, but for broadcasts.  Broadcasts are
361 	 * *not* included in the above count (they are expected to
362 	 * time out).
363 	 */
364 	IPMI_STAT_timed_out_ipmb_broadcasts,
365 
366 	/* Responses I have sent to the IPMB bus. */
367 	IPMI_STAT_sent_ipmb_responses,
368 
369 	/* The response was delivered to the user. */
370 	IPMI_STAT_handled_ipmb_responses,
371 
372 	/* The response had invalid data in it. */
373 	IPMI_STAT_invalid_ipmb_responses,
374 
375 	/* The response didn't have anyone waiting for it. */
376 	IPMI_STAT_unhandled_ipmb_responses,
377 
378 	/* Commands we sent out to the IPMB bus. */
379 	IPMI_STAT_sent_lan_commands,
380 
381 	/* Commands sent on the IPMB that had errors on the SEND CMD */
382 	IPMI_STAT_sent_lan_command_errs,
383 
384 	/* Each retransmit increments this count. */
385 	IPMI_STAT_retransmitted_lan_commands,
386 
387 	/*
388 	 * When a message times out (runs out of retransmits) this is
389 	 * incremented.
390 	 */
391 	IPMI_STAT_timed_out_lan_commands,
392 
393 	/* Responses I have sent to the IPMB bus. */
394 	IPMI_STAT_sent_lan_responses,
395 
396 	/* The response was delivered to the user. */
397 	IPMI_STAT_handled_lan_responses,
398 
399 	/* The response had invalid data in it. */
400 	IPMI_STAT_invalid_lan_responses,
401 
402 	/* The response didn't have anyone waiting for it. */
403 	IPMI_STAT_unhandled_lan_responses,
404 
405 	/* The command was delivered to the user. */
406 	IPMI_STAT_handled_commands,
407 
408 	/* The command had invalid data in it. */
409 	IPMI_STAT_invalid_commands,
410 
411 	/* The command didn't have anyone waiting for it. */
412 	IPMI_STAT_unhandled_commands,
413 
414 	/* Invalid data in an event. */
415 	IPMI_STAT_invalid_events,
416 
417 	/* Events that were received with the proper format. */
418 	IPMI_STAT_events,
419 
420 	/* Retransmissions on IPMB that failed. */
421 	IPMI_STAT_dropped_rexmit_ipmb_commands,
422 
423 	/* Retransmissions on LAN that failed. */
424 	IPMI_STAT_dropped_rexmit_lan_commands,
425 
426 	/* This *must* remain last, add new values above this. */
427 	IPMI_NUM_STATS
428 };
429 
430 
431 #define IPMI_IPMB_NUM_SEQ	64
432 struct ipmi_smi {
433 	struct module *owner;
434 
435 	/* What interface number are we? */
436 	int intf_num;
437 
438 	struct kref refcount;
439 
440 	/* Set when the interface is being unregistered. */
441 	bool in_shutdown;
442 
443 	/* Used for a list of interfaces. */
444 	struct list_head link;
445 
446 	/*
447 	 * The list of upper layers that are using me.
448 	 */
449 	struct list_head users;
450 	struct mutex users_mutex;
451 	atomic_t nr_users;
452 	struct device_attribute nr_users_devattr;
453 	struct device_attribute nr_msgs_devattr;
454 
455 
456 	/* Used for wake ups at startup. */
457 	wait_queue_head_t waitq;
458 
459 	/*
460 	 * Prevents the interface from being unregistered when the
461 	 * interface is used by being looked up through the BMC
462 	 * structure.
463 	 */
464 	struct mutex bmc_reg_mutex;
465 
466 	struct bmc_device tmp_bmc;
467 	struct bmc_device *bmc;
468 	bool bmc_registered;
469 	struct list_head bmc_link;
470 	char *my_dev_name;
471 	bool in_bmc_register;  /* Handle recursive situations.  Yuck. */
472 	struct work_struct bmc_reg_work;
473 
474 	const struct ipmi_smi_handlers *handlers;
475 	void                     *send_info;
476 
477 	/* Driver-model device for the system interface. */
478 	struct device          *si_dev;
479 
480 	/*
481 	 * A table of sequence numbers for this interface.  We use the
482 	 * sequence numbers for IPMB messages that go out of the
483 	 * interface to match them up with their responses.  A routine
484 	 * is called periodically to time the items in this list.
485 	 */
486 	spinlock_t       seq_lock;
487 	struct seq_table seq_table[IPMI_IPMB_NUM_SEQ];
488 	int curr_seq;
489 
490 	/*
491 	 * Messages queued for deliver to the user.
492 	 */
493 	struct mutex user_msgs_mutex;
494 	struct list_head user_msgs;
495 
496 	/*
497 	 * Messages queued for processing.  If processing fails (out
498 	 * of memory for instance), They will stay in here to be
499 	 * processed later in a periodic timer interrupt.  The
500 	 * workqueue is for handling received messages directly from
501 	 * the handler.
502 	 */
503 	spinlock_t       waiting_rcv_msgs_lock;
504 	struct list_head waiting_rcv_msgs;
505 	atomic_t	 watchdog_pretimeouts_to_deliver;
506 	struct work_struct smi_work;
507 
508 	spinlock_t             xmit_msgs_lock;
509 	struct list_head       xmit_msgs;
510 	struct ipmi_smi_msg    *curr_msg;
511 	struct list_head       hp_xmit_msgs;
512 
513 	/*
514 	 * The list of command receivers that are registered for commands
515 	 * on this interface.
516 	 */
517 	struct mutex     cmd_rcvrs_mutex;
518 	struct list_head cmd_rcvrs;
519 
520 	/*
521 	 * Events that were queues because no one was there to receive
522 	 * them.
523 	 */
524 	struct mutex     events_mutex; /* For dealing with event stuff. */
525 	struct list_head waiting_events;
526 	unsigned int     waiting_events_count; /* How many events in queue? */
527 	char             event_msg_printed;
528 
529 	/* How many users are waiting for events? */
530 	atomic_t         event_waiters;
531 	unsigned int     ticks_to_req_ev;
532 
533 	spinlock_t       watch_lock; /* For dealing with watch stuff below. */
534 
535 	/* How many users are waiting for commands? */
536 	unsigned int     command_waiters;
537 
538 	/* How many users are waiting for watchdogs? */
539 	unsigned int     watchdog_waiters;
540 
541 	/* How many users are waiting for message responses? */
542 	unsigned int     response_waiters;
543 
544 	/*
545 	 * Tells what the lower layer has last been asked to watch for,
546 	 * messages and/or watchdogs.  Protected by watch_lock.
547 	 */
548 	unsigned int     last_watch_mask;
549 
550 	/*
551 	 * The event receiver for my BMC, only really used at panic
552 	 * shutdown as a place to store this.
553 	 */
554 	unsigned char event_receiver;
555 	unsigned char event_receiver_lun;
556 	unsigned char local_sel_device;
557 	unsigned char local_event_generator;
558 
559 	/* For handling of maintenance mode. */
560 	int maintenance_mode;
561 	bool maintenance_mode_enable;
562 	int auto_maintenance_timeout;
563 	spinlock_t maintenance_mode_lock; /* Used in a timer... */
564 
565 	/*
566 	 * If we are doing maintenance on something on IPMB, extend
567 	 * the timeout time to avoid timeouts writing firmware and
568 	 * such.
569 	 */
570 	int ipmb_maintenance_mode_timeout;
571 
572 	/*
573 	 * A cheap hack, if this is non-null and a message to an
574 	 * interface comes in with a NULL user, call this routine with
575 	 * it.  Note that the message will still be freed by the
576 	 * caller.  This only works on the system interface.
577 	 *
578 	 * Protected by bmc_reg_mutex.
579 	 */
580 	void (*null_user_handler)(struct ipmi_smi *intf,
581 				  struct ipmi_recv_msg *msg);
582 
583 	/*
584 	 * When we are scanning the channels for an SMI, this will
585 	 * tell which channel we are scanning.
586 	 */
587 	int curr_channel;
588 
589 	/* Channel information */
590 	struct ipmi_channel_set *channel_list;
591 	unsigned int curr_working_cset; /* First index into the following. */
592 	struct ipmi_channel_set wchannels[2];
593 	struct ipmi_my_addrinfo addrinfo[IPMI_MAX_CHANNELS];
594 	bool channels_ready;
595 
596 	atomic_t stats[IPMI_NUM_STATS];
597 
598 	/*
599 	 * run_to_completion duplicate of smb_info, smi_info
600 	 * and ipmi_serial_info structures. Used to decrease numbers of
601 	 * parameters passed by "low" level IPMI code.
602 	 */
603 	int run_to_completion;
604 };
605 #define to_si_intf_from_dev(device) container_of(device, struct ipmi_smi, dev)
606 
607 static void __get_guid(struct ipmi_smi *intf);
608 static void __ipmi_bmc_unregister(struct ipmi_smi *intf);
609 static int __ipmi_bmc_register(struct ipmi_smi *intf,
610 			       struct ipmi_device_id *id,
611 			       bool guid_set, guid_t *guid, int intf_num);
612 static int __scan_channels(struct ipmi_smi *intf, struct ipmi_device_id *id);
613 
614 
615 /*
616  * The driver model view of the IPMI messaging driver.
617  */
618 static struct platform_driver ipmidriver = {
619 	.driver = {
620 		.name = "ipmi",
621 		.bus = &platform_bus_type
622 	}
623 };
624 /*
625  * This mutex keeps us from adding the same BMC twice.
626  */
627 static DEFINE_MUTEX(ipmidriver_mutex);
628 
629 static LIST_HEAD(ipmi_interfaces);
630 static DEFINE_MUTEX(ipmi_interfaces_mutex);
631 
632 /*
633  * List of watchers that want to know when smi's are added and deleted.
634  */
635 static LIST_HEAD(smi_watchers);
636 static DEFINE_MUTEX(smi_watchers_mutex);
637 
638 #define ipmi_inc_stat(intf, stat) \
639 	atomic_inc(&(intf)->stats[IPMI_STAT_ ## stat])
640 #define ipmi_get_stat(intf, stat) \
641 	((unsigned int) atomic_read(&(intf)->stats[IPMI_STAT_ ## stat]))
642 
643 static const char * const addr_src_to_str[] = {
644 	"invalid", "hotmod", "hardcoded", "SPMI", "ACPI", "SMBIOS", "PCI",
645 	"device-tree", "platform"
646 };
647 
648 const char *ipmi_addr_src_to_str(enum ipmi_addr_src src)
649 {
650 	if (src >= SI_LAST)
651 		src = 0; /* Invalid */
652 	return addr_src_to_str[src];
653 }
654 EXPORT_SYMBOL(ipmi_addr_src_to_str);
655 
656 static int is_lan_addr(struct ipmi_addr *addr)
657 {
658 	return addr->addr_type == IPMI_LAN_ADDR_TYPE;
659 }
660 
661 static int is_ipmb_addr(struct ipmi_addr *addr)
662 {
663 	return addr->addr_type == IPMI_IPMB_ADDR_TYPE;
664 }
665 
666 static int is_ipmb_bcast_addr(struct ipmi_addr *addr)
667 {
668 	return addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE;
669 }
670 
671 static int is_ipmb_direct_addr(struct ipmi_addr *addr)
672 {
673 	return addr->addr_type == IPMI_IPMB_DIRECT_ADDR_TYPE;
674 }
675 
676 static void free_recv_msg_list(struct list_head *q)
677 {
678 	struct ipmi_recv_msg *msg, *msg2;
679 
680 	list_for_each_entry_safe(msg, msg2, q, link) {
681 		list_del(&msg->link);
682 		ipmi_free_recv_msg(msg);
683 	}
684 }
685 
686 static void free_smi_msg_list(struct list_head *q)
687 {
688 	struct ipmi_smi_msg *msg, *msg2;
689 
690 	list_for_each_entry_safe(msg, msg2, q, link) {
691 		list_del(&msg->link);
692 		ipmi_free_smi_msg(msg);
693 	}
694 }
695 
696 static void intf_free(struct kref *ref)
697 {
698 	struct ipmi_smi *intf = container_of(ref, struct ipmi_smi, refcount);
699 	int              i;
700 	struct cmd_rcvr  *rcvr, *rcvr2;
701 
702 	free_smi_msg_list(&intf->waiting_rcv_msgs);
703 	free_recv_msg_list(&intf->waiting_events);
704 
705 	/*
706 	 * Wholesale remove all the entries from the list in the
707 	 * interface.  No need for locks, this is single-threaded.
708 	 */
709 	list_for_each_entry_safe(rcvr, rcvr2, &intf->cmd_rcvrs, link)
710 		kfree(rcvr);
711 
712 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
713 		if ((intf->seq_table[i].inuse)
714 					&& (intf->seq_table[i].recv_msg))
715 			ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
716 	}
717 
718 	kfree(intf);
719 }
720 
721 int ipmi_smi_watcher_register(struct ipmi_smi_watcher *watcher)
722 {
723 	struct ipmi_smi *intf;
724 	unsigned int count = 0, i;
725 	int *interfaces = NULL;
726 	struct device **devices = NULL;
727 	int rv = 0;
728 
729 	/*
730 	 * Make sure the driver is actually initialized, this handles
731 	 * problems with initialization order.
732 	 */
733 	rv = ipmi_init_msghandler();
734 	if (rv)
735 		return rv;
736 
737 	mutex_lock(&smi_watchers_mutex);
738 
739 	list_add(&watcher->link, &smi_watchers);
740 
741 	/*
742 	 * Build an array of ipmi interfaces and fill it in, and
743 	 * another array of the devices.  We can't call the callback
744 	 * with ipmi_interfaces_mutex held.  smi_watchers_mutex will
745 	 * keep things in order for the user.
746 	 */
747 	mutex_lock(&ipmi_interfaces_mutex);
748 	list_for_each_entry(intf, &ipmi_interfaces, link)
749 		count++;
750 	if (count > 0) {
751 		interfaces = kmalloc_array(count, sizeof(*interfaces),
752 					   GFP_KERNEL);
753 		if (!interfaces) {
754 			rv = -ENOMEM;
755 		} else {
756 			devices = kmalloc_array(count, sizeof(*devices),
757 						GFP_KERNEL);
758 			if (!devices) {
759 				kfree(interfaces);
760 				interfaces = NULL;
761 				rv = -ENOMEM;
762 			}
763 		}
764 		count = 0;
765 	}
766 	if (interfaces) {
767 		list_for_each_entry(intf, &ipmi_interfaces, link) {
768 			int intf_num = READ_ONCE(intf->intf_num);
769 
770 			if (intf_num == -1)
771 				continue;
772 			devices[count] = intf->si_dev;
773 			interfaces[count++] = intf_num;
774 		}
775 	}
776 	mutex_unlock(&ipmi_interfaces_mutex);
777 
778 	if (interfaces) {
779 		for (i = 0; i < count; i++)
780 			watcher->new_smi(interfaces[i], devices[i]);
781 		kfree(interfaces);
782 		kfree(devices);
783 	}
784 
785 	mutex_unlock(&smi_watchers_mutex);
786 
787 	return rv;
788 }
789 EXPORT_SYMBOL(ipmi_smi_watcher_register);
790 
791 int ipmi_smi_watcher_unregister(struct ipmi_smi_watcher *watcher)
792 {
793 	mutex_lock(&smi_watchers_mutex);
794 	list_del(&watcher->link);
795 	mutex_unlock(&smi_watchers_mutex);
796 	return 0;
797 }
798 EXPORT_SYMBOL(ipmi_smi_watcher_unregister);
799 
800 static void
801 call_smi_watchers(int i, struct device *dev)
802 {
803 	struct ipmi_smi_watcher *w;
804 
805 	list_for_each_entry(w, &smi_watchers, link) {
806 		if (try_module_get(w->owner)) {
807 			w->new_smi(i, dev);
808 			module_put(w->owner);
809 		}
810 	}
811 }
812 
813 static int
814 ipmi_addr_equal(struct ipmi_addr *addr1, struct ipmi_addr *addr2)
815 {
816 	if (addr1->addr_type != addr2->addr_type)
817 		return 0;
818 
819 	if (addr1->channel != addr2->channel)
820 		return 0;
821 
822 	if (addr1->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
823 		struct ipmi_system_interface_addr *smi_addr1
824 		    = (struct ipmi_system_interface_addr *) addr1;
825 		struct ipmi_system_interface_addr *smi_addr2
826 		    = (struct ipmi_system_interface_addr *) addr2;
827 		return (smi_addr1->lun == smi_addr2->lun);
828 	}
829 
830 	if (is_ipmb_addr(addr1) || is_ipmb_bcast_addr(addr1)) {
831 		struct ipmi_ipmb_addr *ipmb_addr1
832 		    = (struct ipmi_ipmb_addr *) addr1;
833 		struct ipmi_ipmb_addr *ipmb_addr2
834 		    = (struct ipmi_ipmb_addr *) addr2;
835 
836 		return ((ipmb_addr1->slave_addr == ipmb_addr2->slave_addr)
837 			&& (ipmb_addr1->lun == ipmb_addr2->lun));
838 	}
839 
840 	if (is_ipmb_direct_addr(addr1)) {
841 		struct ipmi_ipmb_direct_addr *daddr1
842 			= (struct ipmi_ipmb_direct_addr *) addr1;
843 		struct ipmi_ipmb_direct_addr *daddr2
844 			= (struct ipmi_ipmb_direct_addr *) addr2;
845 
846 		return daddr1->slave_addr == daddr2->slave_addr &&
847 			daddr1->rq_lun == daddr2->rq_lun &&
848 			daddr1->rs_lun == daddr2->rs_lun;
849 	}
850 
851 	if (is_lan_addr(addr1)) {
852 		struct ipmi_lan_addr *lan_addr1
853 			= (struct ipmi_lan_addr *) addr1;
854 		struct ipmi_lan_addr *lan_addr2
855 		    = (struct ipmi_lan_addr *) addr2;
856 
857 		return ((lan_addr1->remote_SWID == lan_addr2->remote_SWID)
858 			&& (lan_addr1->local_SWID == lan_addr2->local_SWID)
859 			&& (lan_addr1->session_handle
860 			    == lan_addr2->session_handle)
861 			&& (lan_addr1->lun == lan_addr2->lun));
862 	}
863 
864 	return 1;
865 }
866 
867 int ipmi_validate_addr(struct ipmi_addr *addr, int len)
868 {
869 	if (len < sizeof(struct ipmi_system_interface_addr))
870 		return -EINVAL;
871 
872 	if (addr->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
873 		if (addr->channel != IPMI_BMC_CHANNEL)
874 			return -EINVAL;
875 		return 0;
876 	}
877 
878 	if ((addr->channel == IPMI_BMC_CHANNEL)
879 	    || (addr->channel >= IPMI_MAX_CHANNELS)
880 	    || (addr->channel < 0))
881 		return -EINVAL;
882 
883 	if (is_ipmb_addr(addr) || is_ipmb_bcast_addr(addr)) {
884 		if (len < sizeof(struct ipmi_ipmb_addr))
885 			return -EINVAL;
886 		return 0;
887 	}
888 
889 	if (is_ipmb_direct_addr(addr)) {
890 		struct ipmi_ipmb_direct_addr *daddr = (void *) addr;
891 
892 		if (addr->channel != 0)
893 			return -EINVAL;
894 		if (len < sizeof(struct ipmi_ipmb_direct_addr))
895 			return -EINVAL;
896 
897 		if (daddr->slave_addr & 0x01)
898 			return -EINVAL;
899 		if (daddr->rq_lun >= 4)
900 			return -EINVAL;
901 		if (daddr->rs_lun >= 4)
902 			return -EINVAL;
903 		return 0;
904 	}
905 
906 	if (is_lan_addr(addr)) {
907 		if (len < sizeof(struct ipmi_lan_addr))
908 			return -EINVAL;
909 		return 0;
910 	}
911 
912 	return -EINVAL;
913 }
914 EXPORT_SYMBOL(ipmi_validate_addr);
915 
916 unsigned int ipmi_addr_length(int addr_type)
917 {
918 	if (addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
919 		return sizeof(struct ipmi_system_interface_addr);
920 
921 	if ((addr_type == IPMI_IPMB_ADDR_TYPE)
922 			|| (addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE))
923 		return sizeof(struct ipmi_ipmb_addr);
924 
925 	if (addr_type == IPMI_IPMB_DIRECT_ADDR_TYPE)
926 		return sizeof(struct ipmi_ipmb_direct_addr);
927 
928 	if (addr_type == IPMI_LAN_ADDR_TYPE)
929 		return sizeof(struct ipmi_lan_addr);
930 
931 	return 0;
932 }
933 EXPORT_SYMBOL(ipmi_addr_length);
934 
935 static int deliver_response(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
936 {
937 	int rv = 0;
938 
939 	if (!msg->user) {
940 		/* Special handling for NULL users. */
941 		if (intf->null_user_handler) {
942 			intf->null_user_handler(intf, msg);
943 		} else {
944 			/* No handler, so give up. */
945 			rv = -EINVAL;
946 		}
947 		ipmi_free_recv_msg(msg);
948 	} else if (oops_in_progress) {
949 		/*
950 		 * If we are running in the panic context, calling the
951 		 * receive handler doesn't much meaning and has a deadlock
952 		 * risk.  At this moment, simply skip it in that case.
953 		 */
954 		ipmi_free_recv_msg(msg);
955 		atomic_dec(&msg->user->nr_msgs);
956 	} else {
957 		struct ipmi_user *user = acquire_ipmi_user(msg->user);
958 
959 		if (user) {
960 			/* Deliver it in smi_work. */
961 			mutex_lock(&intf->user_msgs_mutex);
962 			list_add_tail(&msg->link, &intf->user_msgs);
963 			mutex_unlock(&intf->user_msgs_mutex);
964 			queue_work(system_wq, &intf->smi_work);
965 			/* User release will happen in the work queue. */
966 		} else {
967 			/* User went away, give up. */
968 			ipmi_free_recv_msg(msg);
969 			rv = -EINVAL;
970 		}
971 	}
972 
973 	return rv;
974 }
975 
976 static void deliver_local_response(struct ipmi_smi *intf,
977 				   struct ipmi_recv_msg *msg)
978 {
979 	if (deliver_response(intf, msg))
980 		ipmi_inc_stat(intf, unhandled_local_responses);
981 	else
982 		ipmi_inc_stat(intf, handled_local_responses);
983 }
984 
985 static void deliver_err_response(struct ipmi_smi *intf,
986 				 struct ipmi_recv_msg *msg, int err)
987 {
988 	msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
989 	msg->msg_data[0] = err;
990 	msg->msg.netfn |= 1; /* Convert to a response. */
991 	msg->msg.data_len = 1;
992 	msg->msg.data = msg->msg_data;
993 	deliver_local_response(intf, msg);
994 }
995 
996 static void smi_add_watch(struct ipmi_smi *intf, unsigned int flags)
997 {
998 	unsigned long iflags;
999 
1000 	if (!intf->handlers->set_need_watch)
1001 		return;
1002 
1003 	spin_lock_irqsave(&intf->watch_lock, iflags);
1004 	if (flags & IPMI_WATCH_MASK_CHECK_MESSAGES)
1005 		intf->response_waiters++;
1006 
1007 	if (flags & IPMI_WATCH_MASK_CHECK_WATCHDOG)
1008 		intf->watchdog_waiters++;
1009 
1010 	if (flags & IPMI_WATCH_MASK_CHECK_COMMANDS)
1011 		intf->command_waiters++;
1012 
1013 	if ((intf->last_watch_mask & flags) != flags) {
1014 		intf->last_watch_mask |= flags;
1015 		intf->handlers->set_need_watch(intf->send_info,
1016 					       intf->last_watch_mask);
1017 	}
1018 	spin_unlock_irqrestore(&intf->watch_lock, iflags);
1019 }
1020 
1021 static void smi_remove_watch(struct ipmi_smi *intf, unsigned int flags)
1022 {
1023 	unsigned long iflags;
1024 
1025 	if (!intf->handlers->set_need_watch)
1026 		return;
1027 
1028 	spin_lock_irqsave(&intf->watch_lock, iflags);
1029 	if (flags & IPMI_WATCH_MASK_CHECK_MESSAGES)
1030 		intf->response_waiters--;
1031 
1032 	if (flags & IPMI_WATCH_MASK_CHECK_WATCHDOG)
1033 		intf->watchdog_waiters--;
1034 
1035 	if (flags & IPMI_WATCH_MASK_CHECK_COMMANDS)
1036 		intf->command_waiters--;
1037 
1038 	flags = 0;
1039 	if (intf->response_waiters)
1040 		flags |= IPMI_WATCH_MASK_CHECK_MESSAGES;
1041 	if (intf->watchdog_waiters)
1042 		flags |= IPMI_WATCH_MASK_CHECK_WATCHDOG;
1043 	if (intf->command_waiters)
1044 		flags |= IPMI_WATCH_MASK_CHECK_COMMANDS;
1045 
1046 	if (intf->last_watch_mask != flags) {
1047 		intf->last_watch_mask = flags;
1048 		intf->handlers->set_need_watch(intf->send_info,
1049 					       intf->last_watch_mask);
1050 	}
1051 	spin_unlock_irqrestore(&intf->watch_lock, iflags);
1052 }
1053 
1054 /*
1055  * Find the next sequence number not being used and add the given
1056  * message with the given timeout to the sequence table.  This must be
1057  * called with the interface's seq_lock held.
1058  */
1059 static int intf_next_seq(struct ipmi_smi      *intf,
1060 			 struct ipmi_recv_msg *recv_msg,
1061 			 unsigned long        timeout,
1062 			 int                  retries,
1063 			 int                  broadcast,
1064 			 unsigned char        *seq,
1065 			 long                 *seqid)
1066 {
1067 	int          rv = 0;
1068 	unsigned int i;
1069 
1070 	if (timeout == 0)
1071 		timeout = default_retry_ms;
1072 	if (retries < 0)
1073 		retries = default_max_retries;
1074 
1075 	for (i = intf->curr_seq; (i+1)%IPMI_IPMB_NUM_SEQ != intf->curr_seq;
1076 					i = (i+1)%IPMI_IPMB_NUM_SEQ) {
1077 		if (!intf->seq_table[i].inuse)
1078 			break;
1079 	}
1080 
1081 	if (!intf->seq_table[i].inuse) {
1082 		intf->seq_table[i].recv_msg = recv_msg;
1083 
1084 		/*
1085 		 * Start with the maximum timeout, when the send response
1086 		 * comes in we will start the real timer.
1087 		 */
1088 		intf->seq_table[i].timeout = MAX_MSG_TIMEOUT;
1089 		intf->seq_table[i].orig_timeout = timeout;
1090 		intf->seq_table[i].retries_left = retries;
1091 		intf->seq_table[i].broadcast = broadcast;
1092 		intf->seq_table[i].inuse = 1;
1093 		intf->seq_table[i].seqid = NEXT_SEQID(intf->seq_table[i].seqid);
1094 		*seq = i;
1095 		*seqid = intf->seq_table[i].seqid;
1096 		intf->curr_seq = (i+1)%IPMI_IPMB_NUM_SEQ;
1097 		smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1098 		need_waiter(intf);
1099 	} else {
1100 		rv = -EAGAIN;
1101 	}
1102 
1103 	return rv;
1104 }
1105 
1106 /*
1107  * Return the receive message for the given sequence number and
1108  * release the sequence number so it can be reused.  Some other data
1109  * is passed in to be sure the message matches up correctly (to help
1110  * guard against message coming in after their timeout and the
1111  * sequence number being reused).
1112  */
1113 static int intf_find_seq(struct ipmi_smi      *intf,
1114 			 unsigned char        seq,
1115 			 short                channel,
1116 			 unsigned char        cmd,
1117 			 unsigned char        netfn,
1118 			 struct ipmi_addr     *addr,
1119 			 struct ipmi_recv_msg **recv_msg)
1120 {
1121 	int           rv = -ENODEV;
1122 	unsigned long flags;
1123 
1124 	if (seq >= IPMI_IPMB_NUM_SEQ)
1125 		return -EINVAL;
1126 
1127 	spin_lock_irqsave(&intf->seq_lock, flags);
1128 	if (intf->seq_table[seq].inuse) {
1129 		struct ipmi_recv_msg *msg = intf->seq_table[seq].recv_msg;
1130 
1131 		if ((msg->addr.channel == channel) && (msg->msg.cmd == cmd)
1132 				&& (msg->msg.netfn == netfn)
1133 				&& (ipmi_addr_equal(addr, &msg->addr))) {
1134 			*recv_msg = msg;
1135 			intf->seq_table[seq].inuse = 0;
1136 			smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1137 			rv = 0;
1138 		}
1139 	}
1140 	spin_unlock_irqrestore(&intf->seq_lock, flags);
1141 
1142 	return rv;
1143 }
1144 
1145 
1146 /* Start the timer for a specific sequence table entry. */
1147 static int intf_start_seq_timer(struct ipmi_smi *intf,
1148 				long       msgid)
1149 {
1150 	int           rv = -ENODEV;
1151 	unsigned long flags;
1152 	unsigned char seq;
1153 	unsigned long seqid;
1154 
1155 
1156 	GET_SEQ_FROM_MSGID(msgid, seq, seqid);
1157 
1158 	spin_lock_irqsave(&intf->seq_lock, flags);
1159 	/*
1160 	 * We do this verification because the user can be deleted
1161 	 * while a message is outstanding.
1162 	 */
1163 	if ((intf->seq_table[seq].inuse)
1164 				&& (intf->seq_table[seq].seqid == seqid)) {
1165 		struct seq_table *ent = &intf->seq_table[seq];
1166 		ent->timeout = ent->orig_timeout;
1167 		rv = 0;
1168 	}
1169 	spin_unlock_irqrestore(&intf->seq_lock, flags);
1170 
1171 	return rv;
1172 }
1173 
1174 /* Got an error for the send message for a specific sequence number. */
1175 static int intf_err_seq(struct ipmi_smi *intf,
1176 			long         msgid,
1177 			unsigned int err)
1178 {
1179 	int                  rv = -ENODEV;
1180 	unsigned long        flags;
1181 	unsigned char        seq;
1182 	unsigned long        seqid;
1183 	struct ipmi_recv_msg *msg = NULL;
1184 
1185 
1186 	GET_SEQ_FROM_MSGID(msgid, seq, seqid);
1187 
1188 	spin_lock_irqsave(&intf->seq_lock, flags);
1189 	/*
1190 	 * We do this verification because the user can be deleted
1191 	 * while a message is outstanding.
1192 	 */
1193 	if ((intf->seq_table[seq].inuse)
1194 				&& (intf->seq_table[seq].seqid == seqid)) {
1195 		struct seq_table *ent = &intf->seq_table[seq];
1196 
1197 		ent->inuse = 0;
1198 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1199 		msg = ent->recv_msg;
1200 		rv = 0;
1201 	}
1202 	spin_unlock_irqrestore(&intf->seq_lock, flags);
1203 
1204 	if (msg)
1205 		deliver_err_response(intf, msg, err);
1206 
1207 	return rv;
1208 }
1209 
1210 int ipmi_create_user(unsigned int          if_num,
1211 		     const struct ipmi_user_hndl *handler,
1212 		     void                  *handler_data,
1213 		     struct ipmi_user      **user)
1214 {
1215 	unsigned long flags;
1216 	struct ipmi_user *new_user = NULL;
1217 	int           rv = 0;
1218 	struct ipmi_smi *intf;
1219 
1220 	/*
1221 	 * There is no module usecount here, because it's not
1222 	 * required.  Since this can only be used by and called from
1223 	 * other modules, they will implicitly use this module, and
1224 	 * thus this can't be removed unless the other modules are
1225 	 * removed.
1226 	 */
1227 
1228 	if (handler == NULL)
1229 		return -EINVAL;
1230 
1231 	/*
1232 	 * Make sure the driver is actually initialized, this handles
1233 	 * problems with initialization order.
1234 	 */
1235 	rv = ipmi_init_msghandler();
1236 	if (rv)
1237 		return rv;
1238 
1239 	mutex_lock(&ipmi_interfaces_mutex);
1240 	list_for_each_entry(intf, &ipmi_interfaces, link) {
1241 		if (intf->intf_num == if_num)
1242 			goto found;
1243 	}
1244 	/* Not found, return an error */
1245 	rv = -EINVAL;
1246 	goto out_kfree;
1247 
1248  found:
1249 	if (intf->in_shutdown) {
1250 		rv = -ENODEV;
1251 		goto out_kfree;
1252 	}
1253 
1254 	if (atomic_add_return(1, &intf->nr_users) > max_users) {
1255 		rv = -EBUSY;
1256 		goto out_kfree;
1257 	}
1258 
1259 	new_user = vzalloc(sizeof(*new_user));
1260 	if (!new_user) {
1261 		rv = -ENOMEM;
1262 		goto out_kfree;
1263 	}
1264 
1265 	if (!try_module_get(intf->owner)) {
1266 		rv = -ENODEV;
1267 		goto out_kfree;
1268 	}
1269 
1270 	/* Note that each existing user holds a refcount to the interface. */
1271 	kref_get(&intf->refcount);
1272 
1273 	atomic_set(&new_user->nr_msgs, 0);
1274 	kref_init(&new_user->refcount);
1275 	refcount_set(&new_user->destroyed, 1);
1276 	kref_get(&new_user->refcount); /* Destroy owns a refcount. */
1277 	new_user->handler = handler;
1278 	new_user->handler_data = handler_data;
1279 	new_user->intf = intf;
1280 	new_user->gets_events = false;
1281 
1282 	mutex_lock(&intf->users_mutex);
1283 	spin_lock_irqsave(&intf->seq_lock, flags);
1284 	list_add(&new_user->link, &intf->users);
1285 	spin_unlock_irqrestore(&intf->seq_lock, flags);
1286 	mutex_unlock(&intf->users_mutex);
1287 
1288 	if (handler->ipmi_watchdog_pretimeout)
1289 		/* User wants pretimeouts, so make sure to watch for them. */
1290 		smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_WATCHDOG);
1291 
1292 out_kfree:
1293 	if (rv) {
1294 		atomic_dec(&intf->nr_users);
1295 		vfree(new_user);
1296 	} else {
1297 		*user = new_user;
1298 	}
1299 	mutex_unlock(&ipmi_interfaces_mutex);
1300 	return rv;
1301 }
1302 EXPORT_SYMBOL(ipmi_create_user);
1303 
1304 int ipmi_get_smi_info(int if_num, struct ipmi_smi_info *data)
1305 {
1306 	int rv = -EINVAL;
1307 	struct ipmi_smi *intf;
1308 
1309 	mutex_lock(&ipmi_interfaces_mutex);
1310 	list_for_each_entry(intf, &ipmi_interfaces, link) {
1311 		if (intf->intf_num == if_num) {
1312 			if (!intf->handlers->get_smi_info)
1313 				rv = -ENOTTY;
1314 			else
1315 				rv = intf->handlers->get_smi_info(intf->send_info, data);
1316 			break;
1317 		}
1318 	}
1319 	mutex_unlock(&ipmi_interfaces_mutex);
1320 
1321 	return rv;
1322 }
1323 EXPORT_SYMBOL(ipmi_get_smi_info);
1324 
1325 /* Must be called with intf->users_mutex held. */
1326 static void _ipmi_destroy_user(struct ipmi_user *user)
1327 {
1328 	struct ipmi_smi  *intf = user->intf;
1329 	int              i;
1330 	unsigned long    flags;
1331 	struct cmd_rcvr  *rcvr;
1332 	struct cmd_rcvr  *rcvrs = NULL;
1333 	struct module    *owner;
1334 
1335 	if (!refcount_dec_if_one(&user->destroyed))
1336 		return;
1337 
1338 	if (user->handler->shutdown)
1339 		user->handler->shutdown(user->handler_data);
1340 
1341 	if (user->handler->ipmi_watchdog_pretimeout)
1342 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_WATCHDOG);
1343 
1344 	if (user->gets_events)
1345 		atomic_dec(&intf->event_waiters);
1346 
1347 	/* Remove the user from the interface's list and sequence table. */
1348 	list_del(&user->link);
1349 	atomic_dec(&intf->nr_users);
1350 
1351 	spin_lock_irqsave(&intf->seq_lock, flags);
1352 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
1353 		if (intf->seq_table[i].inuse
1354 		    && (intf->seq_table[i].recv_msg->user == user)) {
1355 			intf->seq_table[i].inuse = 0;
1356 			smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
1357 			ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
1358 		}
1359 	}
1360 	spin_unlock_irqrestore(&intf->seq_lock, flags);
1361 
1362 	/*
1363 	 * Remove the user from the command receiver's table.  First
1364 	 * we build a list of everything (not using the standard link,
1365 	 * since other things may be using it till we do
1366 	 * synchronize_rcu()) then free everything in that list.
1367 	 */
1368 	mutex_lock(&intf->cmd_rcvrs_mutex);
1369 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1370 				lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1371 		if (rcvr->user == user) {
1372 			list_del_rcu(&rcvr->link);
1373 			rcvr->next = rcvrs;
1374 			rcvrs = rcvr;
1375 		}
1376 	}
1377 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1378 	while (rcvrs) {
1379 		rcvr = rcvrs;
1380 		rcvrs = rcvr->next;
1381 		kfree(rcvr);
1382 	}
1383 
1384 	release_ipmi_user(user);
1385 
1386 	owner = intf->owner;
1387 	kref_put(&intf->refcount, intf_free);
1388 	module_put(owner);
1389 }
1390 
1391 void ipmi_destroy_user(struct ipmi_user *user)
1392 {
1393 	struct ipmi_smi *intf = user->intf;
1394 
1395 	mutex_lock(&intf->users_mutex);
1396 	_ipmi_destroy_user(user);
1397 	mutex_unlock(&intf->users_mutex);
1398 
1399 	kref_put(&user->refcount, free_ipmi_user);
1400 }
1401 EXPORT_SYMBOL(ipmi_destroy_user);
1402 
1403 int ipmi_get_version(struct ipmi_user *user,
1404 		     unsigned char *major,
1405 		     unsigned char *minor)
1406 {
1407 	struct ipmi_device_id id;
1408 	int rv;
1409 
1410 	user = acquire_ipmi_user(user);
1411 	if (!user)
1412 		return -ENODEV;
1413 
1414 	rv = bmc_get_device_id(user->intf, NULL, &id, NULL, NULL);
1415 	if (!rv) {
1416 		*major = ipmi_version_major(&id);
1417 		*minor = ipmi_version_minor(&id);
1418 	}
1419 	release_ipmi_user(user);
1420 
1421 	return rv;
1422 }
1423 EXPORT_SYMBOL(ipmi_get_version);
1424 
1425 int ipmi_set_my_address(struct ipmi_user *user,
1426 			unsigned int  channel,
1427 			unsigned char address)
1428 {
1429 	int rv = 0;
1430 
1431 	user = acquire_ipmi_user(user);
1432 	if (!user)
1433 		return -ENODEV;
1434 
1435 	if (channel >= IPMI_MAX_CHANNELS) {
1436 		rv = -EINVAL;
1437 	} else {
1438 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1439 		user->intf->addrinfo[channel].address = address;
1440 	}
1441 	release_ipmi_user(user);
1442 
1443 	return rv;
1444 }
1445 EXPORT_SYMBOL(ipmi_set_my_address);
1446 
1447 int ipmi_get_my_address(struct ipmi_user *user,
1448 			unsigned int  channel,
1449 			unsigned char *address)
1450 {
1451 	int rv = 0;
1452 
1453 	user = acquire_ipmi_user(user);
1454 	if (!user)
1455 		return -ENODEV;
1456 
1457 	if (channel >= IPMI_MAX_CHANNELS) {
1458 		rv = -EINVAL;
1459 	} else {
1460 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1461 		*address = user->intf->addrinfo[channel].address;
1462 	}
1463 	release_ipmi_user(user);
1464 
1465 	return rv;
1466 }
1467 EXPORT_SYMBOL(ipmi_get_my_address);
1468 
1469 int ipmi_set_my_LUN(struct ipmi_user *user,
1470 		    unsigned int  channel,
1471 		    unsigned char LUN)
1472 {
1473 	int rv = 0;
1474 
1475 	user = acquire_ipmi_user(user);
1476 	if (!user)
1477 		return -ENODEV;
1478 
1479 	if (channel >= IPMI_MAX_CHANNELS) {
1480 		rv = -EINVAL;
1481 	} else {
1482 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1483 		user->intf->addrinfo[channel].lun = LUN & 0x3;
1484 	}
1485 	release_ipmi_user(user);
1486 
1487 	return rv;
1488 }
1489 EXPORT_SYMBOL(ipmi_set_my_LUN);
1490 
1491 int ipmi_get_my_LUN(struct ipmi_user *user,
1492 		    unsigned int  channel,
1493 		    unsigned char *address)
1494 {
1495 	int rv = 0;
1496 
1497 	user = acquire_ipmi_user(user);
1498 	if (!user)
1499 		return -ENODEV;
1500 
1501 	if (channel >= IPMI_MAX_CHANNELS) {
1502 		rv = -EINVAL;
1503 	} else {
1504 		channel = array_index_nospec(channel, IPMI_MAX_CHANNELS);
1505 		*address = user->intf->addrinfo[channel].lun;
1506 	}
1507 	release_ipmi_user(user);
1508 
1509 	return rv;
1510 }
1511 EXPORT_SYMBOL(ipmi_get_my_LUN);
1512 
1513 int ipmi_get_maintenance_mode(struct ipmi_user *user)
1514 {
1515 	int mode;
1516 	unsigned long flags;
1517 
1518 	user = acquire_ipmi_user(user);
1519 	if (!user)
1520 		return -ENODEV;
1521 
1522 	spin_lock_irqsave(&user->intf->maintenance_mode_lock, flags);
1523 	mode = user->intf->maintenance_mode;
1524 	spin_unlock_irqrestore(&user->intf->maintenance_mode_lock, flags);
1525 	release_ipmi_user(user);
1526 
1527 	return mode;
1528 }
1529 EXPORT_SYMBOL(ipmi_get_maintenance_mode);
1530 
1531 static void maintenance_mode_update(struct ipmi_smi *intf)
1532 {
1533 	if (intf->handlers->set_maintenance_mode)
1534 		intf->handlers->set_maintenance_mode(
1535 			intf->send_info, intf->maintenance_mode_enable);
1536 }
1537 
1538 int ipmi_set_maintenance_mode(struct ipmi_user *user, int mode)
1539 {
1540 	int rv = 0;
1541 	unsigned long flags;
1542 	struct ipmi_smi *intf = user->intf;
1543 
1544 	user = acquire_ipmi_user(user);
1545 	if (!user)
1546 		return -ENODEV;
1547 
1548 	spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
1549 	if (intf->maintenance_mode != mode) {
1550 		switch (mode) {
1551 		case IPMI_MAINTENANCE_MODE_AUTO:
1552 			intf->maintenance_mode_enable
1553 				= (intf->auto_maintenance_timeout > 0);
1554 			break;
1555 
1556 		case IPMI_MAINTENANCE_MODE_OFF:
1557 			intf->maintenance_mode_enable = false;
1558 			break;
1559 
1560 		case IPMI_MAINTENANCE_MODE_ON:
1561 			intf->maintenance_mode_enable = true;
1562 			break;
1563 
1564 		default:
1565 			rv = -EINVAL;
1566 			goto out_unlock;
1567 		}
1568 		intf->maintenance_mode = mode;
1569 
1570 		maintenance_mode_update(intf);
1571 	}
1572  out_unlock:
1573 	spin_unlock_irqrestore(&intf->maintenance_mode_lock, flags);
1574 	release_ipmi_user(user);
1575 
1576 	return rv;
1577 }
1578 EXPORT_SYMBOL(ipmi_set_maintenance_mode);
1579 
1580 int ipmi_set_gets_events(struct ipmi_user *user, bool val)
1581 {
1582 	struct ipmi_smi      *intf = user->intf;
1583 	struct ipmi_recv_msg *msg, *msg2;
1584 	struct list_head     msgs;
1585 
1586 	user = acquire_ipmi_user(user);
1587 	if (!user)
1588 		return -ENODEV;
1589 
1590 	INIT_LIST_HEAD(&msgs);
1591 
1592 	mutex_lock(&intf->events_mutex);
1593 	if (user->gets_events == val)
1594 		goto out;
1595 
1596 	user->gets_events = val;
1597 
1598 	if (val) {
1599 		if (atomic_inc_return(&intf->event_waiters) == 1)
1600 			need_waiter(intf);
1601 	} else {
1602 		atomic_dec(&intf->event_waiters);
1603 	}
1604 
1605 	/* Deliver any queued events. */
1606 	while (user->gets_events && !list_empty(&intf->waiting_events)) {
1607 		list_for_each_entry_safe(msg, msg2, &intf->waiting_events, link)
1608 			list_move_tail(&msg->link, &msgs);
1609 		intf->waiting_events_count = 0;
1610 		if (intf->event_msg_printed) {
1611 			dev_warn(intf->si_dev, "Event queue no longer full\n");
1612 			intf->event_msg_printed = 0;
1613 		}
1614 
1615 		list_for_each_entry_safe(msg, msg2, &msgs, link) {
1616 			msg->user = user;
1617 			kref_get(&user->refcount);
1618 			deliver_local_response(intf, msg);
1619 		}
1620 	}
1621 
1622  out:
1623 	mutex_unlock(&intf->events_mutex);
1624 	release_ipmi_user(user);
1625 
1626 	return 0;
1627 }
1628 EXPORT_SYMBOL(ipmi_set_gets_events);
1629 
1630 static struct cmd_rcvr *find_cmd_rcvr(struct ipmi_smi *intf,
1631 				      unsigned char netfn,
1632 				      unsigned char cmd,
1633 				      unsigned char chan)
1634 {
1635 	struct cmd_rcvr *rcvr;
1636 
1637 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1638 				lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1639 		if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
1640 					&& (rcvr->chans & (1 << chan)))
1641 			return rcvr;
1642 	}
1643 	return NULL;
1644 }
1645 
1646 static int is_cmd_rcvr_exclusive(struct ipmi_smi *intf,
1647 				 unsigned char netfn,
1648 				 unsigned char cmd,
1649 				 unsigned int  chans)
1650 {
1651 	struct cmd_rcvr *rcvr;
1652 
1653 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
1654 				lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
1655 		if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
1656 					&& (rcvr->chans & chans))
1657 			return 0;
1658 	}
1659 	return 1;
1660 }
1661 
1662 int ipmi_register_for_cmd(struct ipmi_user *user,
1663 			  unsigned char netfn,
1664 			  unsigned char cmd,
1665 			  unsigned int  chans)
1666 {
1667 	struct ipmi_smi *intf = user->intf;
1668 	struct cmd_rcvr *rcvr;
1669 	int rv = 0;
1670 
1671 	user = acquire_ipmi_user(user);
1672 	if (!user)
1673 		return -ENODEV;
1674 
1675 	rcvr = kmalloc(sizeof(*rcvr), GFP_KERNEL);
1676 	if (!rcvr) {
1677 		rv = -ENOMEM;
1678 		goto out_release;
1679 	}
1680 	rcvr->cmd = cmd;
1681 	rcvr->netfn = netfn;
1682 	rcvr->chans = chans;
1683 	rcvr->user = user;
1684 
1685 	mutex_lock(&intf->cmd_rcvrs_mutex);
1686 	/* Make sure the command/netfn is not already registered. */
1687 	if (!is_cmd_rcvr_exclusive(intf, netfn, cmd, chans)) {
1688 		rv = -EBUSY;
1689 		goto out_unlock;
1690 	}
1691 
1692 	smi_add_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS);
1693 
1694 	list_add_rcu(&rcvr->link, &intf->cmd_rcvrs);
1695 
1696 out_unlock:
1697 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1698 	if (rv)
1699 		kfree(rcvr);
1700 out_release:
1701 	release_ipmi_user(user);
1702 
1703 	return rv;
1704 }
1705 EXPORT_SYMBOL(ipmi_register_for_cmd);
1706 
1707 int ipmi_unregister_for_cmd(struct ipmi_user *user,
1708 			    unsigned char netfn,
1709 			    unsigned char cmd,
1710 			    unsigned int  chans)
1711 {
1712 	struct ipmi_smi *intf = user->intf;
1713 	struct cmd_rcvr *rcvr;
1714 	struct cmd_rcvr *rcvrs = NULL;
1715 	int i, rv = -ENOENT;
1716 
1717 	user = acquire_ipmi_user(user);
1718 	if (!user)
1719 		return -ENODEV;
1720 
1721 	mutex_lock(&intf->cmd_rcvrs_mutex);
1722 	for (i = 0; i < IPMI_NUM_CHANNELS; i++) {
1723 		if (((1 << i) & chans) == 0)
1724 			continue;
1725 		rcvr = find_cmd_rcvr(intf, netfn, cmd, i);
1726 		if (rcvr == NULL)
1727 			continue;
1728 		if (rcvr->user == user) {
1729 			rv = 0;
1730 			rcvr->chans &= ~chans;
1731 			if (rcvr->chans == 0) {
1732 				list_del_rcu(&rcvr->link);
1733 				rcvr->next = rcvrs;
1734 				rcvrs = rcvr;
1735 			}
1736 		}
1737 	}
1738 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1739 	synchronize_rcu();
1740 	release_ipmi_user(user);
1741 	while (rcvrs) {
1742 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_COMMANDS);
1743 		rcvr = rcvrs;
1744 		rcvrs = rcvr->next;
1745 		kfree(rcvr);
1746 	}
1747 
1748 	return rv;
1749 }
1750 EXPORT_SYMBOL(ipmi_unregister_for_cmd);
1751 
1752 unsigned char
1753 ipmb_checksum(unsigned char *data, int size)
1754 {
1755 	unsigned char csum = 0;
1756 
1757 	for (; size > 0; size--, data++)
1758 		csum += *data;
1759 
1760 	return -csum;
1761 }
1762 EXPORT_SYMBOL(ipmb_checksum);
1763 
1764 static inline void format_ipmb_msg(struct ipmi_smi_msg   *smi_msg,
1765 				   struct kernel_ipmi_msg *msg,
1766 				   struct ipmi_ipmb_addr *ipmb_addr,
1767 				   long                  msgid,
1768 				   unsigned char         ipmb_seq,
1769 				   int                   broadcast,
1770 				   unsigned char         source_address,
1771 				   unsigned char         source_lun)
1772 {
1773 	int i = broadcast;
1774 
1775 	/* Format the IPMB header data. */
1776 	smi_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
1777 	smi_msg->data[1] = IPMI_SEND_MSG_CMD;
1778 	smi_msg->data[2] = ipmb_addr->channel;
1779 	if (broadcast)
1780 		smi_msg->data[3] = 0;
1781 	smi_msg->data[i+3] = ipmb_addr->slave_addr;
1782 	smi_msg->data[i+4] = (msg->netfn << 2) | (ipmb_addr->lun & 0x3);
1783 	smi_msg->data[i+5] = ipmb_checksum(&smi_msg->data[i + 3], 2);
1784 	smi_msg->data[i+6] = source_address;
1785 	smi_msg->data[i+7] = (ipmb_seq << 2) | source_lun;
1786 	smi_msg->data[i+8] = msg->cmd;
1787 
1788 	/* Now tack on the data to the message. */
1789 	if (msg->data_len > 0)
1790 		memcpy(&smi_msg->data[i + 9], msg->data, msg->data_len);
1791 	smi_msg->data_size = msg->data_len + 9;
1792 
1793 	/* Now calculate the checksum and tack it on. */
1794 	smi_msg->data[i+smi_msg->data_size]
1795 		= ipmb_checksum(&smi_msg->data[i + 6], smi_msg->data_size - 6);
1796 
1797 	/*
1798 	 * Add on the checksum size and the offset from the
1799 	 * broadcast.
1800 	 */
1801 	smi_msg->data_size += 1 + i;
1802 
1803 	smi_msg->msgid = msgid;
1804 }
1805 
1806 static inline void format_lan_msg(struct ipmi_smi_msg   *smi_msg,
1807 				  struct kernel_ipmi_msg *msg,
1808 				  struct ipmi_lan_addr  *lan_addr,
1809 				  long                  msgid,
1810 				  unsigned char         ipmb_seq,
1811 				  unsigned char         source_lun)
1812 {
1813 	/* Format the IPMB header data. */
1814 	smi_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
1815 	smi_msg->data[1] = IPMI_SEND_MSG_CMD;
1816 	smi_msg->data[2] = lan_addr->channel;
1817 	smi_msg->data[3] = lan_addr->session_handle;
1818 	smi_msg->data[4] = lan_addr->remote_SWID;
1819 	smi_msg->data[5] = (msg->netfn << 2) | (lan_addr->lun & 0x3);
1820 	smi_msg->data[6] = ipmb_checksum(&smi_msg->data[4], 2);
1821 	smi_msg->data[7] = lan_addr->local_SWID;
1822 	smi_msg->data[8] = (ipmb_seq << 2) | source_lun;
1823 	smi_msg->data[9] = msg->cmd;
1824 
1825 	/* Now tack on the data to the message. */
1826 	if (msg->data_len > 0)
1827 		memcpy(&smi_msg->data[10], msg->data, msg->data_len);
1828 	smi_msg->data_size = msg->data_len + 10;
1829 
1830 	/* Now calculate the checksum and tack it on. */
1831 	smi_msg->data[smi_msg->data_size]
1832 		= ipmb_checksum(&smi_msg->data[7], smi_msg->data_size - 7);
1833 
1834 	/*
1835 	 * Add on the checksum size and the offset from the
1836 	 * broadcast.
1837 	 */
1838 	smi_msg->data_size += 1;
1839 
1840 	smi_msg->msgid = msgid;
1841 }
1842 
1843 static struct ipmi_smi_msg *smi_add_send_msg(struct ipmi_smi *intf,
1844 					     struct ipmi_smi_msg *smi_msg,
1845 					     int priority)
1846 {
1847 	if (intf->curr_msg) {
1848 		if (priority > 0)
1849 			list_add_tail(&smi_msg->link, &intf->hp_xmit_msgs);
1850 		else
1851 			list_add_tail(&smi_msg->link, &intf->xmit_msgs);
1852 		smi_msg = NULL;
1853 	} else {
1854 		intf->curr_msg = smi_msg;
1855 	}
1856 
1857 	return smi_msg;
1858 }
1859 
1860 static void smi_send(struct ipmi_smi *intf,
1861 		     const struct ipmi_smi_handlers *handlers,
1862 		     struct ipmi_smi_msg *smi_msg, int priority)
1863 {
1864 	int run_to_completion = READ_ONCE(intf->run_to_completion);
1865 	unsigned long flags = 0;
1866 
1867 	if (!run_to_completion)
1868 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
1869 	smi_msg = smi_add_send_msg(intf, smi_msg, priority);
1870 	if (!run_to_completion)
1871 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
1872 
1873 	if (smi_msg)
1874 		handlers->sender(intf->send_info, smi_msg);
1875 }
1876 
1877 static bool is_maintenance_mode_cmd(struct kernel_ipmi_msg *msg)
1878 {
1879 	return (((msg->netfn == IPMI_NETFN_APP_REQUEST)
1880 		 && ((msg->cmd == IPMI_COLD_RESET_CMD)
1881 		     || (msg->cmd == IPMI_WARM_RESET_CMD)))
1882 		|| (msg->netfn == IPMI_NETFN_FIRMWARE_REQUEST));
1883 }
1884 
1885 static int i_ipmi_req_sysintf(struct ipmi_smi        *intf,
1886 			      struct ipmi_addr       *addr,
1887 			      long                   msgid,
1888 			      struct kernel_ipmi_msg *msg,
1889 			      struct ipmi_smi_msg    *smi_msg,
1890 			      struct ipmi_recv_msg   *recv_msg,
1891 			      int                    retries,
1892 			      unsigned int           retry_time_ms)
1893 {
1894 	struct ipmi_system_interface_addr *smi_addr;
1895 
1896 	if (msg->netfn & 1)
1897 		/* Responses are not allowed to the SMI. */
1898 		return -EINVAL;
1899 
1900 	smi_addr = (struct ipmi_system_interface_addr *) addr;
1901 	if (smi_addr->lun > 3) {
1902 		ipmi_inc_stat(intf, sent_invalid_commands);
1903 		return -EINVAL;
1904 	}
1905 
1906 	memcpy(&recv_msg->addr, smi_addr, sizeof(*smi_addr));
1907 
1908 	if ((msg->netfn == IPMI_NETFN_APP_REQUEST)
1909 	    && ((msg->cmd == IPMI_SEND_MSG_CMD)
1910 		|| (msg->cmd == IPMI_GET_MSG_CMD)
1911 		|| (msg->cmd == IPMI_READ_EVENT_MSG_BUFFER_CMD))) {
1912 		/*
1913 		 * We don't let the user do these, since we manage
1914 		 * the sequence numbers.
1915 		 */
1916 		ipmi_inc_stat(intf, sent_invalid_commands);
1917 		return -EINVAL;
1918 	}
1919 
1920 	if (is_maintenance_mode_cmd(msg)) {
1921 		unsigned long flags;
1922 
1923 		spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
1924 		intf->auto_maintenance_timeout
1925 			= maintenance_mode_timeout_ms;
1926 		if (!intf->maintenance_mode
1927 		    && !intf->maintenance_mode_enable) {
1928 			intf->maintenance_mode_enable = true;
1929 			maintenance_mode_update(intf);
1930 		}
1931 		spin_unlock_irqrestore(&intf->maintenance_mode_lock,
1932 				       flags);
1933 	}
1934 
1935 	if (msg->data_len + 2 > IPMI_MAX_MSG_LENGTH) {
1936 		ipmi_inc_stat(intf, sent_invalid_commands);
1937 		return -EMSGSIZE;
1938 	}
1939 
1940 	smi_msg->data[0] = (msg->netfn << 2) | (smi_addr->lun & 0x3);
1941 	smi_msg->data[1] = msg->cmd;
1942 	smi_msg->msgid = msgid;
1943 	smi_msg->user_data = recv_msg;
1944 	if (msg->data_len > 0)
1945 		memcpy(&smi_msg->data[2], msg->data, msg->data_len);
1946 	smi_msg->data_size = msg->data_len + 2;
1947 	ipmi_inc_stat(intf, sent_local_commands);
1948 
1949 	return 0;
1950 }
1951 
1952 static int i_ipmi_req_ipmb(struct ipmi_smi        *intf,
1953 			   struct ipmi_addr       *addr,
1954 			   long                   msgid,
1955 			   struct kernel_ipmi_msg *msg,
1956 			   struct ipmi_smi_msg    *smi_msg,
1957 			   struct ipmi_recv_msg   *recv_msg,
1958 			   unsigned char          source_address,
1959 			   unsigned char          source_lun,
1960 			   int                    retries,
1961 			   unsigned int           retry_time_ms)
1962 {
1963 	struct ipmi_ipmb_addr *ipmb_addr;
1964 	unsigned char ipmb_seq;
1965 	long seqid;
1966 	int broadcast = 0;
1967 	struct ipmi_channel *chans;
1968 	int rv = 0;
1969 
1970 	if (addr->channel >= IPMI_MAX_CHANNELS) {
1971 		ipmi_inc_stat(intf, sent_invalid_commands);
1972 		return -EINVAL;
1973 	}
1974 
1975 	chans = READ_ONCE(intf->channel_list)->c;
1976 
1977 	if (chans[addr->channel].medium != IPMI_CHANNEL_MEDIUM_IPMB) {
1978 		ipmi_inc_stat(intf, sent_invalid_commands);
1979 		return -EINVAL;
1980 	}
1981 
1982 	if (addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE) {
1983 		/*
1984 		 * Broadcasts add a zero at the beginning of the
1985 		 * message, but otherwise is the same as an IPMB
1986 		 * address.
1987 		 */
1988 		addr->addr_type = IPMI_IPMB_ADDR_TYPE;
1989 		broadcast = 1;
1990 		retries = 0; /* Don't retry broadcasts. */
1991 	}
1992 
1993 	/*
1994 	 * 9 for the header and 1 for the checksum, plus
1995 	 * possibly one for the broadcast.
1996 	 */
1997 	if ((msg->data_len + 10 + broadcast) > IPMI_MAX_MSG_LENGTH) {
1998 		ipmi_inc_stat(intf, sent_invalid_commands);
1999 		return -EMSGSIZE;
2000 	}
2001 
2002 	ipmb_addr = (struct ipmi_ipmb_addr *) addr;
2003 	if (ipmb_addr->lun > 3) {
2004 		ipmi_inc_stat(intf, sent_invalid_commands);
2005 		return -EINVAL;
2006 	}
2007 
2008 	memcpy(&recv_msg->addr, ipmb_addr, sizeof(*ipmb_addr));
2009 
2010 	if (recv_msg->msg.netfn & 0x1) {
2011 		/*
2012 		 * It's a response, so use the user's sequence
2013 		 * from msgid.
2014 		 */
2015 		ipmi_inc_stat(intf, sent_ipmb_responses);
2016 		format_ipmb_msg(smi_msg, msg, ipmb_addr, msgid,
2017 				msgid, broadcast,
2018 				source_address, source_lun);
2019 
2020 		/*
2021 		 * Save the receive message so we can use it
2022 		 * to deliver the response.
2023 		 */
2024 		smi_msg->user_data = recv_msg;
2025 	} else {
2026 		/* It's a command, so get a sequence for it. */
2027 		unsigned long flags;
2028 
2029 		spin_lock_irqsave(&intf->seq_lock, flags);
2030 
2031 		if (is_maintenance_mode_cmd(msg))
2032 			intf->ipmb_maintenance_mode_timeout =
2033 				maintenance_mode_timeout_ms;
2034 
2035 		if (intf->ipmb_maintenance_mode_timeout && retry_time_ms == 0)
2036 			/* Different default in maintenance mode */
2037 			retry_time_ms = default_maintenance_retry_ms;
2038 
2039 		/*
2040 		 * Create a sequence number with a 1 second
2041 		 * timeout and 4 retries.
2042 		 */
2043 		rv = intf_next_seq(intf,
2044 				   recv_msg,
2045 				   retry_time_ms,
2046 				   retries,
2047 				   broadcast,
2048 				   &ipmb_seq,
2049 				   &seqid);
2050 		if (rv)
2051 			/*
2052 			 * We have used up all the sequence numbers,
2053 			 * probably, so abort.
2054 			 */
2055 			goto out_err;
2056 
2057 		ipmi_inc_stat(intf, sent_ipmb_commands);
2058 
2059 		/*
2060 		 * Store the sequence number in the message,
2061 		 * so that when the send message response
2062 		 * comes back we can start the timer.
2063 		 */
2064 		format_ipmb_msg(smi_msg, msg, ipmb_addr,
2065 				STORE_SEQ_IN_MSGID(ipmb_seq, seqid),
2066 				ipmb_seq, broadcast,
2067 				source_address, source_lun);
2068 
2069 		/*
2070 		 * Copy the message into the recv message data, so we
2071 		 * can retransmit it later if necessary.
2072 		 */
2073 		memcpy(recv_msg->msg_data, smi_msg->data,
2074 		       smi_msg->data_size);
2075 		recv_msg->msg.data = recv_msg->msg_data;
2076 		recv_msg->msg.data_len = smi_msg->data_size;
2077 
2078 		/*
2079 		 * We don't unlock until here, because we need
2080 		 * to copy the completed message into the
2081 		 * recv_msg before we release the lock.
2082 		 * Otherwise, race conditions may bite us.  I
2083 		 * know that's pretty paranoid, but I prefer
2084 		 * to be correct.
2085 		 */
2086 out_err:
2087 		spin_unlock_irqrestore(&intf->seq_lock, flags);
2088 	}
2089 
2090 	return rv;
2091 }
2092 
2093 static int i_ipmi_req_ipmb_direct(struct ipmi_smi        *intf,
2094 				  struct ipmi_addr       *addr,
2095 				  long			 msgid,
2096 				  struct kernel_ipmi_msg *msg,
2097 				  struct ipmi_smi_msg    *smi_msg,
2098 				  struct ipmi_recv_msg   *recv_msg,
2099 				  unsigned char          source_lun)
2100 {
2101 	struct ipmi_ipmb_direct_addr *daddr;
2102 	bool is_cmd = !(recv_msg->msg.netfn & 0x1);
2103 
2104 	if (!(intf->handlers->flags & IPMI_SMI_CAN_HANDLE_IPMB_DIRECT))
2105 		return -EAFNOSUPPORT;
2106 
2107 	/* Responses must have a completion code. */
2108 	if (!is_cmd && msg->data_len < 1) {
2109 		ipmi_inc_stat(intf, sent_invalid_commands);
2110 		return -EINVAL;
2111 	}
2112 
2113 	if ((msg->data_len + 4) > IPMI_MAX_MSG_LENGTH) {
2114 		ipmi_inc_stat(intf, sent_invalid_commands);
2115 		return -EMSGSIZE;
2116 	}
2117 
2118 	daddr = (struct ipmi_ipmb_direct_addr *) addr;
2119 	if (daddr->rq_lun > 3 || daddr->rs_lun > 3) {
2120 		ipmi_inc_stat(intf, sent_invalid_commands);
2121 		return -EINVAL;
2122 	}
2123 
2124 	smi_msg->type = IPMI_SMI_MSG_TYPE_IPMB_DIRECT;
2125 	smi_msg->msgid = msgid;
2126 
2127 	if (is_cmd) {
2128 		smi_msg->data[0] = msg->netfn << 2 | daddr->rs_lun;
2129 		smi_msg->data[2] = recv_msg->msgid << 2 | daddr->rq_lun;
2130 	} else {
2131 		smi_msg->data[0] = msg->netfn << 2 | daddr->rq_lun;
2132 		smi_msg->data[2] = recv_msg->msgid << 2 | daddr->rs_lun;
2133 	}
2134 	smi_msg->data[1] = daddr->slave_addr;
2135 	smi_msg->data[3] = msg->cmd;
2136 
2137 	memcpy(smi_msg->data + 4, msg->data, msg->data_len);
2138 	smi_msg->data_size = msg->data_len + 4;
2139 
2140 	smi_msg->user_data = recv_msg;
2141 
2142 	return 0;
2143 }
2144 
2145 static int i_ipmi_req_lan(struct ipmi_smi        *intf,
2146 			  struct ipmi_addr       *addr,
2147 			  long                   msgid,
2148 			  struct kernel_ipmi_msg *msg,
2149 			  struct ipmi_smi_msg    *smi_msg,
2150 			  struct ipmi_recv_msg   *recv_msg,
2151 			  unsigned char          source_lun,
2152 			  int                    retries,
2153 			  unsigned int           retry_time_ms)
2154 {
2155 	struct ipmi_lan_addr  *lan_addr;
2156 	unsigned char ipmb_seq;
2157 	long seqid;
2158 	struct ipmi_channel *chans;
2159 	int rv = 0;
2160 
2161 	if (addr->channel >= IPMI_MAX_CHANNELS) {
2162 		ipmi_inc_stat(intf, sent_invalid_commands);
2163 		return -EINVAL;
2164 	}
2165 
2166 	chans = READ_ONCE(intf->channel_list)->c;
2167 
2168 	if ((chans[addr->channel].medium
2169 				!= IPMI_CHANNEL_MEDIUM_8023LAN)
2170 			&& (chans[addr->channel].medium
2171 			    != IPMI_CHANNEL_MEDIUM_ASYNC)) {
2172 		ipmi_inc_stat(intf, sent_invalid_commands);
2173 		return -EINVAL;
2174 	}
2175 
2176 	/* 11 for the header and 1 for the checksum. */
2177 	if ((msg->data_len + 12) > IPMI_MAX_MSG_LENGTH) {
2178 		ipmi_inc_stat(intf, sent_invalid_commands);
2179 		return -EMSGSIZE;
2180 	}
2181 
2182 	lan_addr = (struct ipmi_lan_addr *) addr;
2183 	if (lan_addr->lun > 3) {
2184 		ipmi_inc_stat(intf, sent_invalid_commands);
2185 		return -EINVAL;
2186 	}
2187 
2188 	memcpy(&recv_msg->addr, lan_addr, sizeof(*lan_addr));
2189 
2190 	if (recv_msg->msg.netfn & 0x1) {
2191 		/*
2192 		 * It's a response, so use the user's sequence
2193 		 * from msgid.
2194 		 */
2195 		ipmi_inc_stat(intf, sent_lan_responses);
2196 		format_lan_msg(smi_msg, msg, lan_addr, msgid,
2197 			       msgid, source_lun);
2198 
2199 		/*
2200 		 * Save the receive message so we can use it
2201 		 * to deliver the response.
2202 		 */
2203 		smi_msg->user_data = recv_msg;
2204 	} else {
2205 		/* It's a command, so get a sequence for it. */
2206 		unsigned long flags;
2207 
2208 		spin_lock_irqsave(&intf->seq_lock, flags);
2209 
2210 		/*
2211 		 * Create a sequence number with a 1 second
2212 		 * timeout and 4 retries.
2213 		 */
2214 		rv = intf_next_seq(intf,
2215 				   recv_msg,
2216 				   retry_time_ms,
2217 				   retries,
2218 				   0,
2219 				   &ipmb_seq,
2220 				   &seqid);
2221 		if (rv)
2222 			/*
2223 			 * We have used up all the sequence numbers,
2224 			 * probably, so abort.
2225 			 */
2226 			goto out_err;
2227 
2228 		ipmi_inc_stat(intf, sent_lan_commands);
2229 
2230 		/*
2231 		 * Store the sequence number in the message,
2232 		 * so that when the send message response
2233 		 * comes back we can start the timer.
2234 		 */
2235 		format_lan_msg(smi_msg, msg, lan_addr,
2236 			       STORE_SEQ_IN_MSGID(ipmb_seq, seqid),
2237 			       ipmb_seq, source_lun);
2238 
2239 		/*
2240 		 * Copy the message into the recv message data, so we
2241 		 * can retransmit it later if necessary.
2242 		 */
2243 		memcpy(recv_msg->msg_data, smi_msg->data,
2244 		       smi_msg->data_size);
2245 		recv_msg->msg.data = recv_msg->msg_data;
2246 		recv_msg->msg.data_len = smi_msg->data_size;
2247 
2248 		/*
2249 		 * We don't unlock until here, because we need
2250 		 * to copy the completed message into the
2251 		 * recv_msg before we release the lock.
2252 		 * Otherwise, race conditions may bite us.  I
2253 		 * know that's pretty paranoid, but I prefer
2254 		 * to be correct.
2255 		 */
2256 out_err:
2257 		spin_unlock_irqrestore(&intf->seq_lock, flags);
2258 	}
2259 
2260 	return rv;
2261 }
2262 
2263 /*
2264  * Separate from ipmi_request so that the user does not have to be
2265  * supplied in certain circumstances (mainly at panic time).  If
2266  * messages are supplied, they will be freed, even if an error
2267  * occurs.
2268  */
2269 static int i_ipmi_request(struct ipmi_user     *user,
2270 			  struct ipmi_smi      *intf,
2271 			  struct ipmi_addr     *addr,
2272 			  long                 msgid,
2273 			  struct kernel_ipmi_msg *msg,
2274 			  void                 *user_msg_data,
2275 			  void                 *supplied_smi,
2276 			  struct ipmi_recv_msg *supplied_recv,
2277 			  int                  priority,
2278 			  unsigned char        source_address,
2279 			  unsigned char        source_lun,
2280 			  int                  retries,
2281 			  unsigned int         retry_time_ms)
2282 {
2283 	struct ipmi_smi_msg *smi_msg;
2284 	struct ipmi_recv_msg *recv_msg;
2285 	int rv = 0;
2286 
2287 	if (user) {
2288 		if (atomic_add_return(1, &user->nr_msgs) > max_msgs_per_user) {
2289 			/* Decrement will happen at the end of the routine. */
2290 			rv = -EBUSY;
2291 			goto out;
2292 		}
2293 	}
2294 
2295 	if (supplied_recv)
2296 		recv_msg = supplied_recv;
2297 	else {
2298 		recv_msg = ipmi_alloc_recv_msg();
2299 		if (recv_msg == NULL) {
2300 			rv = -ENOMEM;
2301 			goto out;
2302 		}
2303 	}
2304 	recv_msg->user_msg_data = user_msg_data;
2305 
2306 	if (supplied_smi)
2307 		smi_msg = supplied_smi;
2308 	else {
2309 		smi_msg = ipmi_alloc_smi_msg();
2310 		if (smi_msg == NULL) {
2311 			if (!supplied_recv)
2312 				ipmi_free_recv_msg(recv_msg);
2313 			rv = -ENOMEM;
2314 			goto out;
2315 		}
2316 	}
2317 
2318 	mutex_lock(&ipmi_interfaces_mutex);
2319 	if (intf->in_shutdown) {
2320 		rv = -ENODEV;
2321 		goto out_err;
2322 	}
2323 
2324 	recv_msg->user = user;
2325 	if (user)
2326 		/* The put happens when the message is freed. */
2327 		kref_get(&user->refcount);
2328 	recv_msg->msgid = msgid;
2329 	/*
2330 	 * Store the message to send in the receive message so timeout
2331 	 * responses can get the proper response data.
2332 	 */
2333 	recv_msg->msg = *msg;
2334 
2335 	if (addr->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
2336 		rv = i_ipmi_req_sysintf(intf, addr, msgid, msg, smi_msg,
2337 					recv_msg, retries, retry_time_ms);
2338 	} else if (is_ipmb_addr(addr) || is_ipmb_bcast_addr(addr)) {
2339 		rv = i_ipmi_req_ipmb(intf, addr, msgid, msg, smi_msg, recv_msg,
2340 				     source_address, source_lun,
2341 				     retries, retry_time_ms);
2342 	} else if (is_ipmb_direct_addr(addr)) {
2343 		rv = i_ipmi_req_ipmb_direct(intf, addr, msgid, msg, smi_msg,
2344 					    recv_msg, source_lun);
2345 	} else if (is_lan_addr(addr)) {
2346 		rv = i_ipmi_req_lan(intf, addr, msgid, msg, smi_msg, recv_msg,
2347 				    source_lun, retries, retry_time_ms);
2348 	} else {
2349 	    /* Unknown address type. */
2350 		ipmi_inc_stat(intf, sent_invalid_commands);
2351 		rv = -EINVAL;
2352 	}
2353 
2354 	if (rv) {
2355 out_err:
2356 		ipmi_free_smi_msg(smi_msg);
2357 		ipmi_free_recv_msg(recv_msg);
2358 	} else {
2359 		dev_dbg(intf->si_dev, "Send: %*ph\n",
2360 			smi_msg->data_size, smi_msg->data);
2361 
2362 		smi_send(intf, intf->handlers, smi_msg, priority);
2363 	}
2364 	mutex_unlock(&ipmi_interfaces_mutex);
2365 
2366 out:
2367 	if (rv && user)
2368 		atomic_dec(&user->nr_msgs);
2369 	return rv;
2370 }
2371 
2372 static int check_addr(struct ipmi_smi  *intf,
2373 		      struct ipmi_addr *addr,
2374 		      unsigned char    *saddr,
2375 		      unsigned char    *lun)
2376 {
2377 	if (addr->channel >= IPMI_MAX_CHANNELS)
2378 		return -EINVAL;
2379 	addr->channel = array_index_nospec(addr->channel, IPMI_MAX_CHANNELS);
2380 	*lun = intf->addrinfo[addr->channel].lun;
2381 	*saddr = intf->addrinfo[addr->channel].address;
2382 	return 0;
2383 }
2384 
2385 int ipmi_request_settime(struct ipmi_user *user,
2386 			 struct ipmi_addr *addr,
2387 			 long             msgid,
2388 			 struct kernel_ipmi_msg  *msg,
2389 			 void             *user_msg_data,
2390 			 int              priority,
2391 			 int              retries,
2392 			 unsigned int     retry_time_ms)
2393 {
2394 	unsigned char saddr = 0, lun = 0;
2395 	int rv;
2396 
2397 	if (!user)
2398 		return -EINVAL;
2399 
2400 	user = acquire_ipmi_user(user);
2401 	if (!user)
2402 		return -ENODEV;
2403 
2404 	rv = check_addr(user->intf, addr, &saddr, &lun);
2405 	if (!rv)
2406 		rv = i_ipmi_request(user,
2407 				    user->intf,
2408 				    addr,
2409 				    msgid,
2410 				    msg,
2411 				    user_msg_data,
2412 				    NULL, NULL,
2413 				    priority,
2414 				    saddr,
2415 				    lun,
2416 				    retries,
2417 				    retry_time_ms);
2418 
2419 	release_ipmi_user(user);
2420 	return rv;
2421 }
2422 EXPORT_SYMBOL(ipmi_request_settime);
2423 
2424 int ipmi_request_supply_msgs(struct ipmi_user     *user,
2425 			     struct ipmi_addr     *addr,
2426 			     long                 msgid,
2427 			     struct kernel_ipmi_msg *msg,
2428 			     void                 *user_msg_data,
2429 			     void                 *supplied_smi,
2430 			     struct ipmi_recv_msg *supplied_recv,
2431 			     int                  priority)
2432 {
2433 	unsigned char saddr = 0, lun = 0;
2434 	int rv;
2435 
2436 	if (!user)
2437 		return -EINVAL;
2438 
2439 	user = acquire_ipmi_user(user);
2440 	if (!user)
2441 		return -ENODEV;
2442 
2443 	rv = check_addr(user->intf, addr, &saddr, &lun);
2444 	if (!rv)
2445 		rv = i_ipmi_request(user,
2446 				    user->intf,
2447 				    addr,
2448 				    msgid,
2449 				    msg,
2450 				    user_msg_data,
2451 				    supplied_smi,
2452 				    supplied_recv,
2453 				    priority,
2454 				    saddr,
2455 				    lun,
2456 				    -1, 0);
2457 
2458 	release_ipmi_user(user);
2459 	return rv;
2460 }
2461 EXPORT_SYMBOL(ipmi_request_supply_msgs);
2462 
2463 static void bmc_device_id_handler(struct ipmi_smi *intf,
2464 				  struct ipmi_recv_msg *msg)
2465 {
2466 	int rv;
2467 
2468 	if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
2469 			|| (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE)
2470 			|| (msg->msg.cmd != IPMI_GET_DEVICE_ID_CMD)) {
2471 		dev_warn(intf->si_dev,
2472 			 "invalid device_id msg: addr_type=%d netfn=%x cmd=%x\n",
2473 			 msg->addr.addr_type, msg->msg.netfn, msg->msg.cmd);
2474 		return;
2475 	}
2476 
2477 	if (msg->msg.data[0]) {
2478 		dev_warn(intf->si_dev, "device id fetch failed: 0x%2.2x\n",
2479 			 msg->msg.data[0]);
2480 		intf->bmc->dyn_id_set = 0;
2481 		goto out;
2482 	}
2483 
2484 	rv = ipmi_demangle_device_id(msg->msg.netfn, msg->msg.cmd,
2485 			msg->msg.data, msg->msg.data_len, &intf->bmc->fetch_id);
2486 	if (rv) {
2487 		dev_warn(intf->si_dev, "device id demangle failed: %d\n", rv);
2488 		/* record completion code when error */
2489 		intf->bmc->cc = msg->msg.data[0];
2490 		intf->bmc->dyn_id_set = 0;
2491 	} else {
2492 		/*
2493 		 * Make sure the id data is available before setting
2494 		 * dyn_id_set.
2495 		 */
2496 		smp_wmb();
2497 		intf->bmc->dyn_id_set = 1;
2498 	}
2499 out:
2500 	wake_up(&intf->waitq);
2501 }
2502 
2503 static int
2504 send_get_device_id_cmd(struct ipmi_smi *intf)
2505 {
2506 	struct ipmi_system_interface_addr si;
2507 	struct kernel_ipmi_msg msg;
2508 
2509 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
2510 	si.channel = IPMI_BMC_CHANNEL;
2511 	si.lun = 0;
2512 
2513 	msg.netfn = IPMI_NETFN_APP_REQUEST;
2514 	msg.cmd = IPMI_GET_DEVICE_ID_CMD;
2515 	msg.data = NULL;
2516 	msg.data_len = 0;
2517 
2518 	return i_ipmi_request(NULL,
2519 			      intf,
2520 			      (struct ipmi_addr *) &si,
2521 			      0,
2522 			      &msg,
2523 			      intf,
2524 			      NULL,
2525 			      NULL,
2526 			      0,
2527 			      intf->addrinfo[0].address,
2528 			      intf->addrinfo[0].lun,
2529 			      -1, 0);
2530 }
2531 
2532 static int __get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc)
2533 {
2534 	int rv;
2535 	unsigned int retry_count = 0;
2536 
2537 	intf->null_user_handler = bmc_device_id_handler;
2538 
2539 retry:
2540 	bmc->cc = 0;
2541 	bmc->dyn_id_set = 2;
2542 
2543 	rv = send_get_device_id_cmd(intf);
2544 	if (rv)
2545 		goto out_reset_handler;
2546 
2547 	wait_event(intf->waitq, bmc->dyn_id_set != 2);
2548 
2549 	if (!bmc->dyn_id_set) {
2550 		if (bmc->cc != IPMI_CC_NO_ERROR &&
2551 		    ++retry_count <= GET_DEVICE_ID_MAX_RETRY) {
2552 			msleep(500);
2553 			dev_warn(intf->si_dev,
2554 			    "BMC returned 0x%2.2x, retry get bmc device id\n",
2555 			    bmc->cc);
2556 			goto retry;
2557 		}
2558 
2559 		rv = -EIO; /* Something went wrong in the fetch. */
2560 	}
2561 
2562 	/* dyn_id_set makes the id data available. */
2563 	smp_rmb();
2564 
2565 out_reset_handler:
2566 	intf->null_user_handler = NULL;
2567 
2568 	return rv;
2569 }
2570 
2571 /*
2572  * Fetch the device id for the bmc/interface.  You must pass in either
2573  * bmc or intf, this code will get the other one.  If the data has
2574  * been recently fetched, this will just use the cached data.  Otherwise
2575  * it will run a new fetch.
2576  *
2577  * Except for the first time this is called (in ipmi_add_smi()),
2578  * this will always return good data;
2579  */
2580 static int __bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
2581 			       struct ipmi_device_id *id,
2582 			       bool *guid_set, guid_t *guid, int intf_num)
2583 {
2584 	int rv = 0;
2585 	int prev_dyn_id_set, prev_guid_set;
2586 	bool intf_set = intf != NULL;
2587 
2588 	if (!intf) {
2589 		mutex_lock(&bmc->dyn_mutex);
2590 retry_bmc_lock:
2591 		if (list_empty(&bmc->intfs)) {
2592 			mutex_unlock(&bmc->dyn_mutex);
2593 			return -ENOENT;
2594 		}
2595 		intf = list_first_entry(&bmc->intfs, struct ipmi_smi,
2596 					bmc_link);
2597 		kref_get(&intf->refcount);
2598 		mutex_unlock(&bmc->dyn_mutex);
2599 		mutex_lock(&intf->bmc_reg_mutex);
2600 		mutex_lock(&bmc->dyn_mutex);
2601 		if (intf != list_first_entry(&bmc->intfs, struct ipmi_smi,
2602 					     bmc_link)) {
2603 			mutex_unlock(&intf->bmc_reg_mutex);
2604 			kref_put(&intf->refcount, intf_free);
2605 			goto retry_bmc_lock;
2606 		}
2607 	} else {
2608 		mutex_lock(&intf->bmc_reg_mutex);
2609 		bmc = intf->bmc;
2610 		mutex_lock(&bmc->dyn_mutex);
2611 		kref_get(&intf->refcount);
2612 	}
2613 
2614 	/* If we have a valid and current ID, just return that. */
2615 	if (intf->in_bmc_register ||
2616 	    (bmc->dyn_id_set && time_is_after_jiffies(bmc->dyn_id_expiry)))
2617 		goto out_noprocessing;
2618 
2619 	prev_guid_set = bmc->dyn_guid_set;
2620 	__get_guid(intf);
2621 
2622 	prev_dyn_id_set = bmc->dyn_id_set;
2623 	rv = __get_device_id(intf, bmc);
2624 	if (rv)
2625 		goto out;
2626 
2627 	/*
2628 	 * The guid, device id, manufacturer id, and product id should
2629 	 * not change on a BMC.  If it does we have to do some dancing.
2630 	 */
2631 	if (!intf->bmc_registered
2632 	    || (!prev_guid_set && bmc->dyn_guid_set)
2633 	    || (!prev_dyn_id_set && bmc->dyn_id_set)
2634 	    || (prev_guid_set && bmc->dyn_guid_set
2635 		&& !guid_equal(&bmc->guid, &bmc->fetch_guid))
2636 	    || bmc->id.device_id != bmc->fetch_id.device_id
2637 	    || bmc->id.manufacturer_id != bmc->fetch_id.manufacturer_id
2638 	    || bmc->id.product_id != bmc->fetch_id.product_id) {
2639 		struct ipmi_device_id id = bmc->fetch_id;
2640 		int guid_set = bmc->dyn_guid_set;
2641 		guid_t guid;
2642 
2643 		guid = bmc->fetch_guid;
2644 		mutex_unlock(&bmc->dyn_mutex);
2645 
2646 		__ipmi_bmc_unregister(intf);
2647 		/* Fill in the temporary BMC for good measure. */
2648 		intf->bmc->id = id;
2649 		intf->bmc->dyn_guid_set = guid_set;
2650 		intf->bmc->guid = guid;
2651 		if (__ipmi_bmc_register(intf, &id, guid_set, &guid, intf_num))
2652 			need_waiter(intf); /* Retry later on an error. */
2653 		else
2654 			__scan_channels(intf, &id);
2655 
2656 
2657 		if (!intf_set) {
2658 			/*
2659 			 * We weren't given the interface on the
2660 			 * command line, so restart the operation on
2661 			 * the next interface for the BMC.
2662 			 */
2663 			mutex_unlock(&intf->bmc_reg_mutex);
2664 			mutex_lock(&bmc->dyn_mutex);
2665 			goto retry_bmc_lock;
2666 		}
2667 
2668 		/* We have a new BMC, set it up. */
2669 		bmc = intf->bmc;
2670 		mutex_lock(&bmc->dyn_mutex);
2671 		goto out_noprocessing;
2672 	} else if (memcmp(&bmc->fetch_id, &bmc->id, sizeof(bmc->id)))
2673 		/* Version info changes, scan the channels again. */
2674 		__scan_channels(intf, &bmc->fetch_id);
2675 
2676 	bmc->dyn_id_expiry = jiffies + IPMI_DYN_DEV_ID_EXPIRY;
2677 
2678 out:
2679 	if (rv && prev_dyn_id_set) {
2680 		rv = 0; /* Ignore failures if we have previous data. */
2681 		bmc->dyn_id_set = prev_dyn_id_set;
2682 	}
2683 	if (!rv) {
2684 		bmc->id = bmc->fetch_id;
2685 		if (bmc->dyn_guid_set)
2686 			bmc->guid = bmc->fetch_guid;
2687 		else if (prev_guid_set)
2688 			/*
2689 			 * The guid used to be valid and it failed to fetch,
2690 			 * just use the cached value.
2691 			 */
2692 			bmc->dyn_guid_set = prev_guid_set;
2693 	}
2694 out_noprocessing:
2695 	if (!rv) {
2696 		if (id)
2697 			*id = bmc->id;
2698 
2699 		if (guid_set)
2700 			*guid_set = bmc->dyn_guid_set;
2701 
2702 		if (guid && bmc->dyn_guid_set)
2703 			*guid =  bmc->guid;
2704 	}
2705 
2706 	mutex_unlock(&bmc->dyn_mutex);
2707 	mutex_unlock(&intf->bmc_reg_mutex);
2708 
2709 	kref_put(&intf->refcount, intf_free);
2710 	return rv;
2711 }
2712 
2713 static int bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
2714 			     struct ipmi_device_id *id,
2715 			     bool *guid_set, guid_t *guid)
2716 {
2717 	return __bmc_get_device_id(intf, bmc, id, guid_set, guid, -1);
2718 }
2719 
2720 static ssize_t device_id_show(struct device *dev,
2721 			      struct device_attribute *attr,
2722 			      char *buf)
2723 {
2724 	struct bmc_device *bmc = to_bmc_device(dev);
2725 	struct ipmi_device_id id;
2726 	int rv;
2727 
2728 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2729 	if (rv)
2730 		return rv;
2731 
2732 	return sysfs_emit(buf, "%u\n", id.device_id);
2733 }
2734 static DEVICE_ATTR_RO(device_id);
2735 
2736 static ssize_t provides_device_sdrs_show(struct device *dev,
2737 					 struct device_attribute *attr,
2738 					 char *buf)
2739 {
2740 	struct bmc_device *bmc = to_bmc_device(dev);
2741 	struct ipmi_device_id id;
2742 	int rv;
2743 
2744 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2745 	if (rv)
2746 		return rv;
2747 
2748 	return sysfs_emit(buf, "%u\n", (id.device_revision & 0x80) >> 7);
2749 }
2750 static DEVICE_ATTR_RO(provides_device_sdrs);
2751 
2752 static ssize_t revision_show(struct device *dev, struct device_attribute *attr,
2753 			     char *buf)
2754 {
2755 	struct bmc_device *bmc = to_bmc_device(dev);
2756 	struct ipmi_device_id id;
2757 	int rv;
2758 
2759 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2760 	if (rv)
2761 		return rv;
2762 
2763 	return sysfs_emit(buf, "%u\n", id.device_revision & 0x0F);
2764 }
2765 static DEVICE_ATTR_RO(revision);
2766 
2767 static ssize_t firmware_revision_show(struct device *dev,
2768 				      struct device_attribute *attr,
2769 				      char *buf)
2770 {
2771 	struct bmc_device *bmc = to_bmc_device(dev);
2772 	struct ipmi_device_id id;
2773 	int rv;
2774 
2775 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2776 	if (rv)
2777 		return rv;
2778 
2779 	return sysfs_emit(buf, "%u.%x\n", id.firmware_revision_1,
2780 			id.firmware_revision_2);
2781 }
2782 static DEVICE_ATTR_RO(firmware_revision);
2783 
2784 static ssize_t ipmi_version_show(struct device *dev,
2785 				 struct device_attribute *attr,
2786 				 char *buf)
2787 {
2788 	struct bmc_device *bmc = to_bmc_device(dev);
2789 	struct ipmi_device_id id;
2790 	int rv;
2791 
2792 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2793 	if (rv)
2794 		return rv;
2795 
2796 	return sysfs_emit(buf, "%u.%u\n",
2797 			ipmi_version_major(&id),
2798 			ipmi_version_minor(&id));
2799 }
2800 static DEVICE_ATTR_RO(ipmi_version);
2801 
2802 static ssize_t add_dev_support_show(struct device *dev,
2803 				    struct device_attribute *attr,
2804 				    char *buf)
2805 {
2806 	struct bmc_device *bmc = to_bmc_device(dev);
2807 	struct ipmi_device_id id;
2808 	int rv;
2809 
2810 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2811 	if (rv)
2812 		return rv;
2813 
2814 	return sysfs_emit(buf, "0x%02x\n", id.additional_device_support);
2815 }
2816 static DEVICE_ATTR(additional_device_support, S_IRUGO, add_dev_support_show,
2817 		   NULL);
2818 
2819 static ssize_t manufacturer_id_show(struct device *dev,
2820 				    struct device_attribute *attr,
2821 				    char *buf)
2822 {
2823 	struct bmc_device *bmc = to_bmc_device(dev);
2824 	struct ipmi_device_id id;
2825 	int rv;
2826 
2827 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2828 	if (rv)
2829 		return rv;
2830 
2831 	return sysfs_emit(buf, "0x%6.6x\n", id.manufacturer_id);
2832 }
2833 static DEVICE_ATTR_RO(manufacturer_id);
2834 
2835 static ssize_t product_id_show(struct device *dev,
2836 			       struct device_attribute *attr,
2837 			       char *buf)
2838 {
2839 	struct bmc_device *bmc = to_bmc_device(dev);
2840 	struct ipmi_device_id id;
2841 	int rv;
2842 
2843 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2844 	if (rv)
2845 		return rv;
2846 
2847 	return sysfs_emit(buf, "0x%4.4x\n", id.product_id);
2848 }
2849 static DEVICE_ATTR_RO(product_id);
2850 
2851 static ssize_t aux_firmware_rev_show(struct device *dev,
2852 				     struct device_attribute *attr,
2853 				     char *buf)
2854 {
2855 	struct bmc_device *bmc = to_bmc_device(dev);
2856 	struct ipmi_device_id id;
2857 	int rv;
2858 
2859 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2860 	if (rv)
2861 		return rv;
2862 
2863 	return sysfs_emit(buf, "0x%02x 0x%02x 0x%02x 0x%02x\n",
2864 			id.aux_firmware_revision[3],
2865 			id.aux_firmware_revision[2],
2866 			id.aux_firmware_revision[1],
2867 			id.aux_firmware_revision[0]);
2868 }
2869 static DEVICE_ATTR(aux_firmware_revision, S_IRUGO, aux_firmware_rev_show, NULL);
2870 
2871 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
2872 			 char *buf)
2873 {
2874 	struct bmc_device *bmc = to_bmc_device(dev);
2875 	bool guid_set;
2876 	guid_t guid;
2877 	int rv;
2878 
2879 	rv = bmc_get_device_id(NULL, bmc, NULL, &guid_set, &guid);
2880 	if (rv)
2881 		return rv;
2882 	if (!guid_set)
2883 		return -ENOENT;
2884 
2885 	return sysfs_emit(buf, "%pUl\n", &guid);
2886 }
2887 static DEVICE_ATTR_RO(guid);
2888 
2889 static struct attribute *bmc_dev_attrs[] = {
2890 	&dev_attr_device_id.attr,
2891 	&dev_attr_provides_device_sdrs.attr,
2892 	&dev_attr_revision.attr,
2893 	&dev_attr_firmware_revision.attr,
2894 	&dev_attr_ipmi_version.attr,
2895 	&dev_attr_additional_device_support.attr,
2896 	&dev_attr_manufacturer_id.attr,
2897 	&dev_attr_product_id.attr,
2898 	&dev_attr_aux_firmware_revision.attr,
2899 	&dev_attr_guid.attr,
2900 	NULL
2901 };
2902 
2903 static umode_t bmc_dev_attr_is_visible(struct kobject *kobj,
2904 				       struct attribute *attr, int idx)
2905 {
2906 	struct device *dev = kobj_to_dev(kobj);
2907 	struct bmc_device *bmc = to_bmc_device(dev);
2908 	umode_t mode = attr->mode;
2909 	int rv;
2910 
2911 	if (attr == &dev_attr_aux_firmware_revision.attr) {
2912 		struct ipmi_device_id id;
2913 
2914 		rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2915 		return (!rv && id.aux_firmware_revision_set) ? mode : 0;
2916 	}
2917 	if (attr == &dev_attr_guid.attr) {
2918 		bool guid_set;
2919 
2920 		rv = bmc_get_device_id(NULL, bmc, NULL, &guid_set, NULL);
2921 		return (!rv && guid_set) ? mode : 0;
2922 	}
2923 	return mode;
2924 }
2925 
2926 static const struct attribute_group bmc_dev_attr_group = {
2927 	.attrs		= bmc_dev_attrs,
2928 	.is_visible	= bmc_dev_attr_is_visible,
2929 };
2930 
2931 static const struct attribute_group *bmc_dev_attr_groups[] = {
2932 	&bmc_dev_attr_group,
2933 	NULL
2934 };
2935 
2936 static const struct device_type bmc_device_type = {
2937 	.groups		= bmc_dev_attr_groups,
2938 };
2939 
2940 static int __find_bmc_guid(struct device *dev, const void *data)
2941 {
2942 	const guid_t *guid = data;
2943 	struct bmc_device *bmc;
2944 	int rv;
2945 
2946 	if (dev->type != &bmc_device_type)
2947 		return 0;
2948 
2949 	bmc = to_bmc_device(dev);
2950 	rv = bmc->dyn_guid_set && guid_equal(&bmc->guid, guid);
2951 	if (rv)
2952 		rv = kref_get_unless_zero(&bmc->usecount);
2953 	return rv;
2954 }
2955 
2956 /*
2957  * Returns with the bmc's usecount incremented, if it is non-NULL.
2958  */
2959 static struct bmc_device *ipmi_find_bmc_guid(struct device_driver *drv,
2960 					     guid_t *guid)
2961 {
2962 	struct device *dev;
2963 	struct bmc_device *bmc = NULL;
2964 
2965 	dev = driver_find_device(drv, NULL, guid, __find_bmc_guid);
2966 	if (dev) {
2967 		bmc = to_bmc_device(dev);
2968 		put_device(dev);
2969 	}
2970 	return bmc;
2971 }
2972 
2973 struct prod_dev_id {
2974 	unsigned int  product_id;
2975 	unsigned char device_id;
2976 };
2977 
2978 static int __find_bmc_prod_dev_id(struct device *dev, const void *data)
2979 {
2980 	const struct prod_dev_id *cid = data;
2981 	struct bmc_device *bmc;
2982 	int rv;
2983 
2984 	if (dev->type != &bmc_device_type)
2985 		return 0;
2986 
2987 	bmc = to_bmc_device(dev);
2988 	rv = (bmc->id.product_id == cid->product_id
2989 	      && bmc->id.device_id == cid->device_id);
2990 	if (rv)
2991 		rv = kref_get_unless_zero(&bmc->usecount);
2992 	return rv;
2993 }
2994 
2995 /*
2996  * Returns with the bmc's usecount incremented, if it is non-NULL.
2997  */
2998 static struct bmc_device *ipmi_find_bmc_prod_dev_id(
2999 	struct device_driver *drv,
3000 	unsigned int product_id, unsigned char device_id)
3001 {
3002 	struct prod_dev_id id = {
3003 		.product_id = product_id,
3004 		.device_id = device_id,
3005 	};
3006 	struct device *dev;
3007 	struct bmc_device *bmc = NULL;
3008 
3009 	dev = driver_find_device(drv, NULL, &id, __find_bmc_prod_dev_id);
3010 	if (dev) {
3011 		bmc = to_bmc_device(dev);
3012 		put_device(dev);
3013 	}
3014 	return bmc;
3015 }
3016 
3017 static DEFINE_IDA(ipmi_bmc_ida);
3018 
3019 static void
3020 release_bmc_device(struct device *dev)
3021 {
3022 	kfree(to_bmc_device(dev));
3023 }
3024 
3025 static void cleanup_bmc_work(struct work_struct *work)
3026 {
3027 	struct bmc_device *bmc = container_of(work, struct bmc_device,
3028 					      remove_work);
3029 	int id = bmc->pdev.id; /* Unregister overwrites id */
3030 
3031 	platform_device_unregister(&bmc->pdev);
3032 	ida_free(&ipmi_bmc_ida, id);
3033 }
3034 
3035 static void
3036 cleanup_bmc_device(struct kref *ref)
3037 {
3038 	struct bmc_device *bmc = container_of(ref, struct bmc_device, usecount);
3039 
3040 	/*
3041 	 * Remove the platform device in a work queue to avoid issues
3042 	 * with removing the device attributes while reading a device
3043 	 * attribute.
3044 	 */
3045 	queue_work(bmc_remove_work_wq, &bmc->remove_work);
3046 }
3047 
3048 /*
3049  * Must be called with intf->bmc_reg_mutex held.
3050  */
3051 static void __ipmi_bmc_unregister(struct ipmi_smi *intf)
3052 {
3053 	struct bmc_device *bmc = intf->bmc;
3054 
3055 	if (!intf->bmc_registered)
3056 		return;
3057 
3058 	sysfs_remove_link(&intf->si_dev->kobj, "bmc");
3059 	sysfs_remove_link(&bmc->pdev.dev.kobj, intf->my_dev_name);
3060 	kfree(intf->my_dev_name);
3061 	intf->my_dev_name = NULL;
3062 
3063 	mutex_lock(&bmc->dyn_mutex);
3064 	list_del(&intf->bmc_link);
3065 	mutex_unlock(&bmc->dyn_mutex);
3066 	intf->bmc = &intf->tmp_bmc;
3067 	kref_put(&bmc->usecount, cleanup_bmc_device);
3068 	intf->bmc_registered = false;
3069 }
3070 
3071 static void ipmi_bmc_unregister(struct ipmi_smi *intf)
3072 {
3073 	mutex_lock(&intf->bmc_reg_mutex);
3074 	__ipmi_bmc_unregister(intf);
3075 	mutex_unlock(&intf->bmc_reg_mutex);
3076 }
3077 
3078 /*
3079  * Must be called with intf->bmc_reg_mutex held.
3080  */
3081 static int __ipmi_bmc_register(struct ipmi_smi *intf,
3082 			       struct ipmi_device_id *id,
3083 			       bool guid_set, guid_t *guid, int intf_num)
3084 {
3085 	int               rv;
3086 	struct bmc_device *bmc;
3087 	struct bmc_device *old_bmc;
3088 
3089 	/*
3090 	 * platform_device_register() can cause bmc_reg_mutex to
3091 	 * be claimed because of the is_visible functions of
3092 	 * the attributes.  Eliminate possible recursion and
3093 	 * release the lock.
3094 	 */
3095 	intf->in_bmc_register = true;
3096 	mutex_unlock(&intf->bmc_reg_mutex);
3097 
3098 	/*
3099 	 * Try to find if there is an bmc_device struct
3100 	 * representing the interfaced BMC already
3101 	 */
3102 	mutex_lock(&ipmidriver_mutex);
3103 	if (guid_set)
3104 		old_bmc = ipmi_find_bmc_guid(&ipmidriver.driver, guid);
3105 	else
3106 		old_bmc = ipmi_find_bmc_prod_dev_id(&ipmidriver.driver,
3107 						    id->product_id,
3108 						    id->device_id);
3109 
3110 	/*
3111 	 * If there is already an bmc_device, free the new one,
3112 	 * otherwise register the new BMC device
3113 	 */
3114 	if (old_bmc) {
3115 		bmc = old_bmc;
3116 		/*
3117 		 * Note: old_bmc already has usecount incremented by
3118 		 * the BMC find functions.
3119 		 */
3120 		intf->bmc = old_bmc;
3121 		mutex_lock(&bmc->dyn_mutex);
3122 		list_add_tail(&intf->bmc_link, &bmc->intfs);
3123 		mutex_unlock(&bmc->dyn_mutex);
3124 
3125 		dev_info(intf->si_dev,
3126 			 "interfacing existing BMC (man_id: 0x%6.6x, prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n",
3127 			 bmc->id.manufacturer_id,
3128 			 bmc->id.product_id,
3129 			 bmc->id.device_id);
3130 	} else {
3131 		bmc = kzalloc(sizeof(*bmc), GFP_KERNEL);
3132 		if (!bmc) {
3133 			rv = -ENOMEM;
3134 			goto out;
3135 		}
3136 		INIT_LIST_HEAD(&bmc->intfs);
3137 		mutex_init(&bmc->dyn_mutex);
3138 		INIT_WORK(&bmc->remove_work, cleanup_bmc_work);
3139 
3140 		bmc->id = *id;
3141 		bmc->dyn_id_set = 1;
3142 		bmc->dyn_guid_set = guid_set;
3143 		bmc->guid = *guid;
3144 		bmc->dyn_id_expiry = jiffies + IPMI_DYN_DEV_ID_EXPIRY;
3145 
3146 		bmc->pdev.name = "ipmi_bmc";
3147 
3148 		rv = ida_alloc(&ipmi_bmc_ida, GFP_KERNEL);
3149 		if (rv < 0) {
3150 			kfree(bmc);
3151 			goto out;
3152 		}
3153 
3154 		bmc->pdev.dev.driver = &ipmidriver.driver;
3155 		bmc->pdev.id = rv;
3156 		bmc->pdev.dev.release = release_bmc_device;
3157 		bmc->pdev.dev.type = &bmc_device_type;
3158 		kref_init(&bmc->usecount);
3159 
3160 		intf->bmc = bmc;
3161 		mutex_lock(&bmc->dyn_mutex);
3162 		list_add_tail(&intf->bmc_link, &bmc->intfs);
3163 		mutex_unlock(&bmc->dyn_mutex);
3164 
3165 		rv = platform_device_register(&bmc->pdev);
3166 		if (rv) {
3167 			dev_err(intf->si_dev,
3168 				"Unable to register bmc device: %d\n",
3169 				rv);
3170 			goto out_list_del;
3171 		}
3172 
3173 		dev_info(intf->si_dev,
3174 			 "Found new BMC (man_id: 0x%6.6x, prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n",
3175 			 bmc->id.manufacturer_id,
3176 			 bmc->id.product_id,
3177 			 bmc->id.device_id);
3178 	}
3179 
3180 	/*
3181 	 * create symlink from system interface device to bmc device
3182 	 * and back.
3183 	 */
3184 	rv = sysfs_create_link(&intf->si_dev->kobj, &bmc->pdev.dev.kobj, "bmc");
3185 	if (rv) {
3186 		dev_err(intf->si_dev, "Unable to create bmc symlink: %d\n", rv);
3187 		goto out_put_bmc;
3188 	}
3189 
3190 	if (intf_num == -1)
3191 		intf_num = intf->intf_num;
3192 	intf->my_dev_name = kasprintf(GFP_KERNEL, "ipmi%d", intf_num);
3193 	if (!intf->my_dev_name) {
3194 		rv = -ENOMEM;
3195 		dev_err(intf->si_dev, "Unable to allocate link from BMC: %d\n",
3196 			rv);
3197 		goto out_unlink1;
3198 	}
3199 
3200 	rv = sysfs_create_link(&bmc->pdev.dev.kobj, &intf->si_dev->kobj,
3201 			       intf->my_dev_name);
3202 	if (rv) {
3203 		dev_err(intf->si_dev, "Unable to create symlink to bmc: %d\n",
3204 			rv);
3205 		goto out_free_my_dev_name;
3206 	}
3207 
3208 	intf->bmc_registered = true;
3209 
3210 out:
3211 	mutex_unlock(&ipmidriver_mutex);
3212 	mutex_lock(&intf->bmc_reg_mutex);
3213 	intf->in_bmc_register = false;
3214 	return rv;
3215 
3216 
3217 out_free_my_dev_name:
3218 	kfree(intf->my_dev_name);
3219 	intf->my_dev_name = NULL;
3220 
3221 out_unlink1:
3222 	sysfs_remove_link(&intf->si_dev->kobj, "bmc");
3223 
3224 out_put_bmc:
3225 	mutex_lock(&bmc->dyn_mutex);
3226 	list_del(&intf->bmc_link);
3227 	mutex_unlock(&bmc->dyn_mutex);
3228 	intf->bmc = &intf->tmp_bmc;
3229 	kref_put(&bmc->usecount, cleanup_bmc_device);
3230 	goto out;
3231 
3232 out_list_del:
3233 	mutex_lock(&bmc->dyn_mutex);
3234 	list_del(&intf->bmc_link);
3235 	mutex_unlock(&bmc->dyn_mutex);
3236 	intf->bmc = &intf->tmp_bmc;
3237 	put_device(&bmc->pdev.dev);
3238 	goto out;
3239 }
3240 
3241 static int
3242 send_guid_cmd(struct ipmi_smi *intf, int chan)
3243 {
3244 	struct kernel_ipmi_msg            msg;
3245 	struct ipmi_system_interface_addr si;
3246 
3247 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
3248 	si.channel = IPMI_BMC_CHANNEL;
3249 	si.lun = 0;
3250 
3251 	msg.netfn = IPMI_NETFN_APP_REQUEST;
3252 	msg.cmd = IPMI_GET_DEVICE_GUID_CMD;
3253 	msg.data = NULL;
3254 	msg.data_len = 0;
3255 	return i_ipmi_request(NULL,
3256 			      intf,
3257 			      (struct ipmi_addr *) &si,
3258 			      0,
3259 			      &msg,
3260 			      intf,
3261 			      NULL,
3262 			      NULL,
3263 			      0,
3264 			      intf->addrinfo[0].address,
3265 			      intf->addrinfo[0].lun,
3266 			      -1, 0);
3267 }
3268 
3269 static void guid_handler(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
3270 {
3271 	struct bmc_device *bmc = intf->bmc;
3272 
3273 	if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
3274 	    || (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE)
3275 	    || (msg->msg.cmd != IPMI_GET_DEVICE_GUID_CMD))
3276 		/* Not for me */
3277 		return;
3278 
3279 	if (msg->msg.data[0] != 0) {
3280 		/* Error from getting the GUID, the BMC doesn't have one. */
3281 		bmc->dyn_guid_set = 0;
3282 		goto out;
3283 	}
3284 
3285 	if (msg->msg.data_len < UUID_SIZE + 1) {
3286 		bmc->dyn_guid_set = 0;
3287 		dev_warn(intf->si_dev,
3288 			 "The GUID response from the BMC was too short, it was %d but should have been %d.  Assuming GUID is not available.\n",
3289 			 msg->msg.data_len, UUID_SIZE + 1);
3290 		goto out;
3291 	}
3292 
3293 	import_guid(&bmc->fetch_guid, msg->msg.data + 1);
3294 	/*
3295 	 * Make sure the guid data is available before setting
3296 	 * dyn_guid_set.
3297 	 */
3298 	smp_wmb();
3299 	bmc->dyn_guid_set = 1;
3300  out:
3301 	wake_up(&intf->waitq);
3302 }
3303 
3304 static void __get_guid(struct ipmi_smi *intf)
3305 {
3306 	int rv;
3307 	struct bmc_device *bmc = intf->bmc;
3308 
3309 	bmc->dyn_guid_set = 2;
3310 	intf->null_user_handler = guid_handler;
3311 	rv = send_guid_cmd(intf, 0);
3312 	if (rv)
3313 		/* Send failed, no GUID available. */
3314 		bmc->dyn_guid_set = 0;
3315 	else
3316 		wait_event(intf->waitq, bmc->dyn_guid_set != 2);
3317 
3318 	/* dyn_guid_set makes the guid data available. */
3319 	smp_rmb();
3320 
3321 	intf->null_user_handler = NULL;
3322 }
3323 
3324 static int
3325 send_channel_info_cmd(struct ipmi_smi *intf, int chan)
3326 {
3327 	struct kernel_ipmi_msg            msg;
3328 	unsigned char                     data[1];
3329 	struct ipmi_system_interface_addr si;
3330 
3331 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
3332 	si.channel = IPMI_BMC_CHANNEL;
3333 	si.lun = 0;
3334 
3335 	msg.netfn = IPMI_NETFN_APP_REQUEST;
3336 	msg.cmd = IPMI_GET_CHANNEL_INFO_CMD;
3337 	msg.data = data;
3338 	msg.data_len = 1;
3339 	data[0] = chan;
3340 	return i_ipmi_request(NULL,
3341 			      intf,
3342 			      (struct ipmi_addr *) &si,
3343 			      0,
3344 			      &msg,
3345 			      intf,
3346 			      NULL,
3347 			      NULL,
3348 			      0,
3349 			      intf->addrinfo[0].address,
3350 			      intf->addrinfo[0].lun,
3351 			      -1, 0);
3352 }
3353 
3354 static void
3355 channel_handler(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
3356 {
3357 	int rv = 0;
3358 	int ch;
3359 	unsigned int set = intf->curr_working_cset;
3360 	struct ipmi_channel *chans;
3361 
3362 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
3363 	    && (msg->msg.netfn == IPMI_NETFN_APP_RESPONSE)
3364 	    && (msg->msg.cmd == IPMI_GET_CHANNEL_INFO_CMD)) {
3365 		/* It's the one we want */
3366 		if (msg->msg.data[0] != 0) {
3367 			/* Got an error from the channel, just go on. */
3368 			if (msg->msg.data[0] == IPMI_INVALID_COMMAND_ERR) {
3369 				/*
3370 				 * If the MC does not support this
3371 				 * command, that is legal.  We just
3372 				 * assume it has one IPMB at channel
3373 				 * zero.
3374 				 */
3375 				intf->wchannels[set].c[0].medium
3376 					= IPMI_CHANNEL_MEDIUM_IPMB;
3377 				intf->wchannels[set].c[0].protocol
3378 					= IPMI_CHANNEL_PROTOCOL_IPMB;
3379 
3380 				intf->channel_list = intf->wchannels + set;
3381 				intf->channels_ready = true;
3382 				wake_up(&intf->waitq);
3383 				goto out;
3384 			}
3385 			goto next_channel;
3386 		}
3387 		if (msg->msg.data_len < 4) {
3388 			/* Message not big enough, just go on. */
3389 			goto next_channel;
3390 		}
3391 		ch = intf->curr_channel;
3392 		chans = intf->wchannels[set].c;
3393 		chans[ch].medium = msg->msg.data[2] & 0x7f;
3394 		chans[ch].protocol = msg->msg.data[3] & 0x1f;
3395 
3396  next_channel:
3397 		intf->curr_channel++;
3398 		if (intf->curr_channel >= IPMI_MAX_CHANNELS) {
3399 			intf->channel_list = intf->wchannels + set;
3400 			intf->channels_ready = true;
3401 			wake_up(&intf->waitq);
3402 		} else {
3403 			intf->channel_list = intf->wchannels + set;
3404 			intf->channels_ready = true;
3405 			rv = send_channel_info_cmd(intf, intf->curr_channel);
3406 		}
3407 
3408 		if (rv) {
3409 			/* Got an error somehow, just give up. */
3410 			dev_warn(intf->si_dev,
3411 				 "Error sending channel information for channel %d: %d\n",
3412 				 intf->curr_channel, rv);
3413 
3414 			intf->channel_list = intf->wchannels + set;
3415 			intf->channels_ready = true;
3416 			wake_up(&intf->waitq);
3417 		}
3418 	}
3419  out:
3420 	return;
3421 }
3422 
3423 /*
3424  * Must be holding intf->bmc_reg_mutex to call this.
3425  */
3426 static int __scan_channels(struct ipmi_smi *intf, struct ipmi_device_id *id)
3427 {
3428 	int rv;
3429 
3430 	if (ipmi_version_major(id) > 1
3431 			|| (ipmi_version_major(id) == 1
3432 			    && ipmi_version_minor(id) >= 5)) {
3433 		unsigned int set;
3434 
3435 		/*
3436 		 * Start scanning the channels to see what is
3437 		 * available.
3438 		 */
3439 		set = !intf->curr_working_cset;
3440 		intf->curr_working_cset = set;
3441 		memset(&intf->wchannels[set], 0,
3442 		       sizeof(struct ipmi_channel_set));
3443 
3444 		intf->null_user_handler = channel_handler;
3445 		intf->curr_channel = 0;
3446 		rv = send_channel_info_cmd(intf, 0);
3447 		if (rv) {
3448 			dev_warn(intf->si_dev,
3449 				 "Error sending channel information for channel 0, %d\n",
3450 				 rv);
3451 			intf->null_user_handler = NULL;
3452 			return -EIO;
3453 		}
3454 
3455 		/* Wait for the channel info to be read. */
3456 		wait_event(intf->waitq, intf->channels_ready);
3457 		intf->null_user_handler = NULL;
3458 	} else {
3459 		unsigned int set = intf->curr_working_cset;
3460 
3461 		/* Assume a single IPMB channel at zero. */
3462 		intf->wchannels[set].c[0].medium = IPMI_CHANNEL_MEDIUM_IPMB;
3463 		intf->wchannels[set].c[0].protocol = IPMI_CHANNEL_PROTOCOL_IPMB;
3464 		intf->channel_list = intf->wchannels + set;
3465 		intf->channels_ready = true;
3466 	}
3467 
3468 	return 0;
3469 }
3470 
3471 static void ipmi_poll(struct ipmi_smi *intf)
3472 {
3473 	if (intf->handlers->poll)
3474 		intf->handlers->poll(intf->send_info);
3475 	/* In case something came in */
3476 	handle_new_recv_msgs(intf);
3477 }
3478 
3479 void ipmi_poll_interface(struct ipmi_user *user)
3480 {
3481 	ipmi_poll(user->intf);
3482 }
3483 EXPORT_SYMBOL(ipmi_poll_interface);
3484 
3485 static ssize_t nr_users_show(struct device *dev,
3486 			     struct device_attribute *attr,
3487 			     char *buf)
3488 {
3489 	struct ipmi_smi *intf = container_of(attr,
3490 			 struct ipmi_smi, nr_users_devattr);
3491 
3492 	return sysfs_emit(buf, "%d\n", atomic_read(&intf->nr_users));
3493 }
3494 static DEVICE_ATTR_RO(nr_users);
3495 
3496 static ssize_t nr_msgs_show(struct device *dev,
3497 			    struct device_attribute *attr,
3498 			    char *buf)
3499 {
3500 	struct ipmi_smi *intf = container_of(attr,
3501 					     struct ipmi_smi, nr_msgs_devattr);
3502 	struct ipmi_user *user;
3503 	unsigned int count = 0;
3504 
3505 	mutex_lock(&intf->users_mutex);
3506 	list_for_each_entry(user, &intf->users, link)
3507 		count += atomic_read(&user->nr_msgs);
3508 	mutex_unlock(&intf->users_mutex);
3509 
3510 	return sysfs_emit(buf, "%u\n", count);
3511 }
3512 static DEVICE_ATTR_RO(nr_msgs);
3513 
3514 static void redo_bmc_reg(struct work_struct *work)
3515 {
3516 	struct ipmi_smi *intf = container_of(work, struct ipmi_smi,
3517 					     bmc_reg_work);
3518 
3519 	if (!intf->in_shutdown)
3520 		bmc_get_device_id(intf, NULL, NULL, NULL, NULL);
3521 
3522 	kref_put(&intf->refcount, intf_free);
3523 }
3524 
3525 int ipmi_add_smi(struct module         *owner,
3526 		 const struct ipmi_smi_handlers *handlers,
3527 		 void		       *send_info,
3528 		 struct device         *si_dev,
3529 		 unsigned char         slave_addr)
3530 {
3531 	int              i, j;
3532 	int              rv;
3533 	struct ipmi_smi *intf, *tintf;
3534 	struct list_head *link;
3535 	struct ipmi_device_id id;
3536 
3537 	/*
3538 	 * Make sure the driver is actually initialized, this handles
3539 	 * problems with initialization order.
3540 	 */
3541 	rv = ipmi_init_msghandler();
3542 	if (rv)
3543 		return rv;
3544 
3545 	intf = kzalloc(sizeof(*intf), GFP_KERNEL);
3546 	if (!intf)
3547 		return -ENOMEM;
3548 
3549 	intf->owner = owner;
3550 	intf->bmc = &intf->tmp_bmc;
3551 	INIT_LIST_HEAD(&intf->bmc->intfs);
3552 	mutex_init(&intf->bmc->dyn_mutex);
3553 	INIT_LIST_HEAD(&intf->bmc_link);
3554 	mutex_init(&intf->bmc_reg_mutex);
3555 	intf->intf_num = -1; /* Mark it invalid for now. */
3556 	kref_init(&intf->refcount);
3557 	INIT_WORK(&intf->bmc_reg_work, redo_bmc_reg);
3558 	intf->si_dev = si_dev;
3559 	for (j = 0; j < IPMI_MAX_CHANNELS; j++) {
3560 		intf->addrinfo[j].address = IPMI_BMC_SLAVE_ADDR;
3561 		intf->addrinfo[j].lun = 2;
3562 	}
3563 	if (slave_addr != 0)
3564 		intf->addrinfo[0].address = slave_addr;
3565 	INIT_LIST_HEAD(&intf->user_msgs);
3566 	mutex_init(&intf->user_msgs_mutex);
3567 	INIT_LIST_HEAD(&intf->users);
3568 	mutex_init(&intf->users_mutex);
3569 	atomic_set(&intf->nr_users, 0);
3570 	intf->handlers = handlers;
3571 	intf->send_info = send_info;
3572 	spin_lock_init(&intf->seq_lock);
3573 	for (j = 0; j < IPMI_IPMB_NUM_SEQ; j++) {
3574 		intf->seq_table[j].inuse = 0;
3575 		intf->seq_table[j].seqid = 0;
3576 	}
3577 	intf->curr_seq = 0;
3578 	spin_lock_init(&intf->waiting_rcv_msgs_lock);
3579 	INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
3580 	INIT_WORK(&intf->smi_work, smi_work);
3581 	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 0);
3582 	spin_lock_init(&intf->xmit_msgs_lock);
3583 	INIT_LIST_HEAD(&intf->xmit_msgs);
3584 	INIT_LIST_HEAD(&intf->hp_xmit_msgs);
3585 	mutex_init(&intf->events_mutex);
3586 	spin_lock_init(&intf->watch_lock);
3587 	atomic_set(&intf->event_waiters, 0);
3588 	intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
3589 	INIT_LIST_HEAD(&intf->waiting_events);
3590 	intf->waiting_events_count = 0;
3591 	mutex_init(&intf->cmd_rcvrs_mutex);
3592 	spin_lock_init(&intf->maintenance_mode_lock);
3593 	INIT_LIST_HEAD(&intf->cmd_rcvrs);
3594 	init_waitqueue_head(&intf->waitq);
3595 	for (i = 0; i < IPMI_NUM_STATS; i++)
3596 		atomic_set(&intf->stats[i], 0);
3597 
3598 	/*
3599 	 * Grab the watchers mutex so we can deliver the new interface
3600 	 * without races.
3601 	 */
3602 	mutex_lock(&smi_watchers_mutex);
3603 	mutex_lock(&ipmi_interfaces_mutex);
3604 	/* Look for a hole in the numbers. */
3605 	i = 0;
3606 	link = &ipmi_interfaces;
3607 	list_for_each_entry(tintf, &ipmi_interfaces, link) {
3608 		if (tintf->intf_num != i) {
3609 			link = &tintf->link;
3610 			break;
3611 		}
3612 		i++;
3613 	}
3614 	/* Add the new interface in numeric order. */
3615 	if (i == 0)
3616 		list_add(&intf->link, &ipmi_interfaces);
3617 	else
3618 		list_add_tail(&intf->link, link);
3619 
3620 	rv = handlers->start_processing(send_info, intf);
3621 	if (rv)
3622 		goto out_err;
3623 
3624 	rv = __bmc_get_device_id(intf, NULL, &id, NULL, NULL, i);
3625 	if (rv) {
3626 		dev_err(si_dev, "Unable to get the device id: %d\n", rv);
3627 		goto out_err_started;
3628 	}
3629 
3630 	mutex_lock(&intf->bmc_reg_mutex);
3631 	rv = __scan_channels(intf, &id);
3632 	mutex_unlock(&intf->bmc_reg_mutex);
3633 	if (rv)
3634 		goto out_err_bmc_reg;
3635 
3636 	intf->nr_users_devattr = dev_attr_nr_users;
3637 	sysfs_attr_init(&intf->nr_users_devattr.attr);
3638 	rv = device_create_file(intf->si_dev, &intf->nr_users_devattr);
3639 	if (rv)
3640 		goto out_err_bmc_reg;
3641 
3642 	intf->nr_msgs_devattr = dev_attr_nr_msgs;
3643 	sysfs_attr_init(&intf->nr_msgs_devattr.attr);
3644 	rv = device_create_file(intf->si_dev, &intf->nr_msgs_devattr);
3645 	if (rv) {
3646 		device_remove_file(intf->si_dev, &intf->nr_users_devattr);
3647 		goto out_err_bmc_reg;
3648 	}
3649 
3650 	intf->intf_num = i;
3651 	mutex_unlock(&ipmi_interfaces_mutex);
3652 
3653 	/* After this point the interface is legal to use. */
3654 	call_smi_watchers(i, intf->si_dev);
3655 
3656 	mutex_unlock(&smi_watchers_mutex);
3657 
3658 	return 0;
3659 
3660  out_err_bmc_reg:
3661 	ipmi_bmc_unregister(intf);
3662  out_err_started:
3663 	if (intf->handlers->shutdown)
3664 		intf->handlers->shutdown(intf->send_info);
3665  out_err:
3666 	list_del(&intf->link);
3667 	mutex_unlock(&ipmi_interfaces_mutex);
3668 	mutex_unlock(&smi_watchers_mutex);
3669 	kref_put(&intf->refcount, intf_free);
3670 
3671 	return rv;
3672 }
3673 EXPORT_SYMBOL(ipmi_add_smi);
3674 
3675 static void deliver_smi_err_response(struct ipmi_smi *intf,
3676 				     struct ipmi_smi_msg *msg,
3677 				     unsigned char err)
3678 {
3679 	int rv;
3680 	msg->rsp[0] = msg->data[0] | 4;
3681 	msg->rsp[1] = msg->data[1];
3682 	msg->rsp[2] = err;
3683 	msg->rsp_size = 3;
3684 
3685 	/* This will never requeue, but it may ask us to free the message. */
3686 	rv = handle_one_recv_msg(intf, msg);
3687 	if (rv == 0)
3688 		ipmi_free_smi_msg(msg);
3689 }
3690 
3691 static void cleanup_smi_msgs(struct ipmi_smi *intf)
3692 {
3693 	int              i;
3694 	struct seq_table *ent;
3695 	struct ipmi_smi_msg *msg;
3696 	struct list_head *entry;
3697 	struct list_head tmplist;
3698 
3699 	/* Clear out our transmit queues and hold the messages. */
3700 	INIT_LIST_HEAD(&tmplist);
3701 	list_splice_tail(&intf->hp_xmit_msgs, &tmplist);
3702 	list_splice_tail(&intf->xmit_msgs, &tmplist);
3703 
3704 	/* Current message first, to preserve order */
3705 	while (intf->curr_msg && !list_empty(&intf->waiting_rcv_msgs)) {
3706 		/* Wait for the message to clear out. */
3707 		schedule_timeout(1);
3708 	}
3709 
3710 	/* No need for locks, the interface is down. */
3711 
3712 	/*
3713 	 * Return errors for all pending messages in queue and in the
3714 	 * tables waiting for remote responses.
3715 	 */
3716 	while (!list_empty(&tmplist)) {
3717 		entry = tmplist.next;
3718 		list_del(entry);
3719 		msg = list_entry(entry, struct ipmi_smi_msg, link);
3720 		deliver_smi_err_response(intf, msg, IPMI_ERR_UNSPECIFIED);
3721 	}
3722 
3723 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
3724 		ent = &intf->seq_table[i];
3725 		if (!ent->inuse)
3726 			continue;
3727 		deliver_err_response(intf, ent->recv_msg, IPMI_ERR_UNSPECIFIED);
3728 	}
3729 }
3730 
3731 void ipmi_unregister_smi(struct ipmi_smi *intf)
3732 {
3733 	struct ipmi_smi_watcher *w;
3734 	int intf_num;
3735 
3736 	if (!intf)
3737 		return;
3738 
3739 	intf_num = intf->intf_num;
3740 	mutex_lock(&ipmi_interfaces_mutex);
3741 	cancel_work_sync(&intf->smi_work);
3742 	/* smi_work() can no longer be in progress after this. */
3743 
3744 	intf->intf_num = -1;
3745 	intf->in_shutdown = true;
3746 	list_del(&intf->link);
3747 	mutex_unlock(&ipmi_interfaces_mutex);
3748 
3749 	/* At this point no users can be added to the interface. */
3750 
3751 	device_remove_file(intf->si_dev, &intf->nr_msgs_devattr);
3752 	device_remove_file(intf->si_dev, &intf->nr_users_devattr);
3753 
3754 	/*
3755 	 * Call all the watcher interfaces to tell them that
3756 	 * an interface is going away.
3757 	 */
3758 	mutex_lock(&smi_watchers_mutex);
3759 	list_for_each_entry(w, &smi_watchers, link)
3760 		w->smi_gone(intf_num);
3761 	mutex_unlock(&smi_watchers_mutex);
3762 
3763 	mutex_lock(&intf->users_mutex);
3764 	while (!list_empty(&intf->users)) {
3765 		struct ipmi_user *user = list_first_entry(&intf->users,
3766 						    struct ipmi_user, link);
3767 
3768 		_ipmi_destroy_user(user);
3769 	}
3770 	mutex_unlock(&intf->users_mutex);
3771 
3772 	if (intf->handlers->shutdown)
3773 		intf->handlers->shutdown(intf->send_info);
3774 
3775 	cleanup_smi_msgs(intf);
3776 
3777 	ipmi_bmc_unregister(intf);
3778 
3779 	kref_put(&intf->refcount, intf_free);
3780 }
3781 EXPORT_SYMBOL(ipmi_unregister_smi);
3782 
3783 static int handle_ipmb_get_msg_rsp(struct ipmi_smi *intf,
3784 				   struct ipmi_smi_msg *msg)
3785 {
3786 	struct ipmi_ipmb_addr ipmb_addr;
3787 	struct ipmi_recv_msg  *recv_msg;
3788 
3789 	/*
3790 	 * This is 11, not 10, because the response must contain a
3791 	 * completion code.
3792 	 */
3793 	if (msg->rsp_size < 11) {
3794 		/* Message not big enough, just ignore it. */
3795 		ipmi_inc_stat(intf, invalid_ipmb_responses);
3796 		return 0;
3797 	}
3798 
3799 	if (msg->rsp[2] != 0) {
3800 		/* An error getting the response, just ignore it. */
3801 		return 0;
3802 	}
3803 
3804 	ipmb_addr.addr_type = IPMI_IPMB_ADDR_TYPE;
3805 	ipmb_addr.slave_addr = msg->rsp[6];
3806 	ipmb_addr.channel = msg->rsp[3] & 0x0f;
3807 	ipmb_addr.lun = msg->rsp[7] & 3;
3808 
3809 	/*
3810 	 * It's a response from a remote entity.  Look up the sequence
3811 	 * number and handle the response.
3812 	 */
3813 	if (intf_find_seq(intf,
3814 			  msg->rsp[7] >> 2,
3815 			  msg->rsp[3] & 0x0f,
3816 			  msg->rsp[8],
3817 			  (msg->rsp[4] >> 2) & (~1),
3818 			  (struct ipmi_addr *) &ipmb_addr,
3819 			  &recv_msg)) {
3820 		/*
3821 		 * We were unable to find the sequence number,
3822 		 * so just nuke the message.
3823 		 */
3824 		ipmi_inc_stat(intf, unhandled_ipmb_responses);
3825 		return 0;
3826 	}
3827 
3828 	memcpy(recv_msg->msg_data, &msg->rsp[9], msg->rsp_size - 9);
3829 	/*
3830 	 * The other fields matched, so no need to set them, except
3831 	 * for netfn, which needs to be the response that was
3832 	 * returned, not the request value.
3833 	 */
3834 	recv_msg->msg.netfn = msg->rsp[4] >> 2;
3835 	recv_msg->msg.data = recv_msg->msg_data;
3836 	recv_msg->msg.data_len = msg->rsp_size - 10;
3837 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
3838 	if (deliver_response(intf, recv_msg))
3839 		ipmi_inc_stat(intf, unhandled_ipmb_responses);
3840 	else
3841 		ipmi_inc_stat(intf, handled_ipmb_responses);
3842 
3843 	return 0;
3844 }
3845 
3846 static int handle_ipmb_get_msg_cmd(struct ipmi_smi *intf,
3847 				   struct ipmi_smi_msg *msg)
3848 {
3849 	struct cmd_rcvr          *rcvr;
3850 	int                      rv = 0;
3851 	unsigned char            netfn;
3852 	unsigned char            cmd;
3853 	unsigned char            chan;
3854 	struct ipmi_user         *user = NULL;
3855 	struct ipmi_ipmb_addr    *ipmb_addr;
3856 	struct ipmi_recv_msg     *recv_msg;
3857 
3858 	if (msg->rsp_size < 10) {
3859 		/* Message not big enough, just ignore it. */
3860 		ipmi_inc_stat(intf, invalid_commands);
3861 		return 0;
3862 	}
3863 
3864 	if (msg->rsp[2] != 0) {
3865 		/* An error getting the response, just ignore it. */
3866 		return 0;
3867 	}
3868 
3869 	netfn = msg->rsp[4] >> 2;
3870 	cmd = msg->rsp[8];
3871 	chan = msg->rsp[3] & 0xf;
3872 
3873 	rcu_read_lock();
3874 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
3875 	if (rcvr) {
3876 		user = rcvr->user;
3877 		kref_get(&user->refcount);
3878 	} else
3879 		user = NULL;
3880 	rcu_read_unlock();
3881 
3882 	if (user == NULL) {
3883 		/* We didn't find a user, deliver an error response. */
3884 		ipmi_inc_stat(intf, unhandled_commands);
3885 
3886 		msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
3887 		msg->data[1] = IPMI_SEND_MSG_CMD;
3888 		msg->data[2] = msg->rsp[3];
3889 		msg->data[3] = msg->rsp[6];
3890 		msg->data[4] = ((netfn + 1) << 2) | (msg->rsp[7] & 0x3);
3891 		msg->data[5] = ipmb_checksum(&msg->data[3], 2);
3892 		msg->data[6] = intf->addrinfo[msg->rsp[3] & 0xf].address;
3893 		/* rqseq/lun */
3894 		msg->data[7] = (msg->rsp[7] & 0xfc) | (msg->rsp[4] & 0x3);
3895 		msg->data[8] = msg->rsp[8]; /* cmd */
3896 		msg->data[9] = IPMI_INVALID_CMD_COMPLETION_CODE;
3897 		msg->data[10] = ipmb_checksum(&msg->data[6], 4);
3898 		msg->data_size = 11;
3899 
3900 		dev_dbg(intf->si_dev, "Invalid command: %*ph\n",
3901 			msg->data_size, msg->data);
3902 
3903 		mutex_lock(&ipmi_interfaces_mutex);
3904 		if (!intf->in_shutdown) {
3905 			smi_send(intf, intf->handlers, msg, 0);
3906 			/*
3907 			 * We used the message, so return the value
3908 			 * that causes it to not be freed or
3909 			 * queued.
3910 			 */
3911 			rv = -1;
3912 		}
3913 		mutex_unlock(&ipmi_interfaces_mutex);
3914 	} else {
3915 		recv_msg = ipmi_alloc_recv_msg();
3916 		if (!recv_msg) {
3917 			/*
3918 			 * We couldn't allocate memory for the
3919 			 * message, so requeue it for handling
3920 			 * later.
3921 			 */
3922 			rv = 1;
3923 			kref_put(&user->refcount, free_ipmi_user);
3924 		} else {
3925 			/* Extract the source address from the data. */
3926 			ipmb_addr = (struct ipmi_ipmb_addr *) &recv_msg->addr;
3927 			ipmb_addr->addr_type = IPMI_IPMB_ADDR_TYPE;
3928 			ipmb_addr->slave_addr = msg->rsp[6];
3929 			ipmb_addr->lun = msg->rsp[7] & 3;
3930 			ipmb_addr->channel = msg->rsp[3] & 0xf;
3931 
3932 			/*
3933 			 * Extract the rest of the message information
3934 			 * from the IPMB header.
3935 			 */
3936 			recv_msg->user = user;
3937 			recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
3938 			recv_msg->msgid = msg->rsp[7] >> 2;
3939 			recv_msg->msg.netfn = msg->rsp[4] >> 2;
3940 			recv_msg->msg.cmd = msg->rsp[8];
3941 			recv_msg->msg.data = recv_msg->msg_data;
3942 
3943 			/*
3944 			 * We chop off 10, not 9 bytes because the checksum
3945 			 * at the end also needs to be removed.
3946 			 */
3947 			recv_msg->msg.data_len = msg->rsp_size - 10;
3948 			memcpy(recv_msg->msg_data, &msg->rsp[9],
3949 			       msg->rsp_size - 10);
3950 			if (deliver_response(intf, recv_msg))
3951 				ipmi_inc_stat(intf, unhandled_commands);
3952 			else
3953 				ipmi_inc_stat(intf, handled_commands);
3954 		}
3955 	}
3956 
3957 	return rv;
3958 }
3959 
3960 static int handle_ipmb_direct_rcv_cmd(struct ipmi_smi *intf,
3961 				      struct ipmi_smi_msg *msg)
3962 {
3963 	struct cmd_rcvr          *rcvr;
3964 	int                      rv = 0;
3965 	struct ipmi_user         *user = NULL;
3966 	struct ipmi_ipmb_direct_addr *daddr;
3967 	struct ipmi_recv_msg     *recv_msg;
3968 	unsigned char netfn = msg->rsp[0] >> 2;
3969 	unsigned char cmd = msg->rsp[3];
3970 
3971 	rcu_read_lock();
3972 	/* We always use channel 0 for direct messages. */
3973 	rcvr = find_cmd_rcvr(intf, netfn, cmd, 0);
3974 	if (rcvr) {
3975 		user = rcvr->user;
3976 		kref_get(&user->refcount);
3977 	} else
3978 		user = NULL;
3979 	rcu_read_unlock();
3980 
3981 	if (user == NULL) {
3982 		/* We didn't find a user, deliver an error response. */
3983 		ipmi_inc_stat(intf, unhandled_commands);
3984 
3985 		msg->data[0] = (netfn + 1) << 2;
3986 		msg->data[0] |= msg->rsp[2] & 0x3; /* rqLUN */
3987 		msg->data[1] = msg->rsp[1]; /* Addr */
3988 		msg->data[2] = msg->rsp[2] & ~0x3; /* rqSeq */
3989 		msg->data[2] |= msg->rsp[0] & 0x3; /* rsLUN */
3990 		msg->data[3] = cmd;
3991 		msg->data[4] = IPMI_INVALID_CMD_COMPLETION_CODE;
3992 		msg->data_size = 5;
3993 
3994 		mutex_lock(&ipmi_interfaces_mutex);
3995 		if (!intf->in_shutdown) {
3996 			smi_send(intf, intf->handlers, msg, 0);
3997 			/*
3998 			 * We used the message, so return the value
3999 			 * that causes it to not be freed or
4000 			 * queued.
4001 			 */
4002 			rv = -1;
4003 		}
4004 		mutex_unlock(&ipmi_interfaces_mutex);
4005 	} else {
4006 		recv_msg = ipmi_alloc_recv_msg();
4007 		if (!recv_msg) {
4008 			/*
4009 			 * We couldn't allocate memory for the
4010 			 * message, so requeue it for handling
4011 			 * later.
4012 			 */
4013 			rv = 1;
4014 			kref_put(&user->refcount, free_ipmi_user);
4015 		} else {
4016 			/* Extract the source address from the data. */
4017 			daddr = (struct ipmi_ipmb_direct_addr *)&recv_msg->addr;
4018 			daddr->addr_type = IPMI_IPMB_DIRECT_ADDR_TYPE;
4019 			daddr->channel = 0;
4020 			daddr->slave_addr = msg->rsp[1];
4021 			daddr->rs_lun = msg->rsp[0] & 3;
4022 			daddr->rq_lun = msg->rsp[2] & 3;
4023 
4024 			/*
4025 			 * Extract the rest of the message information
4026 			 * from the IPMB header.
4027 			 */
4028 			recv_msg->user = user;
4029 			recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
4030 			recv_msg->msgid = (msg->rsp[2] >> 2);
4031 			recv_msg->msg.netfn = msg->rsp[0] >> 2;
4032 			recv_msg->msg.cmd = msg->rsp[3];
4033 			recv_msg->msg.data = recv_msg->msg_data;
4034 
4035 			recv_msg->msg.data_len = msg->rsp_size - 4;
4036 			memcpy(recv_msg->msg_data, msg->rsp + 4,
4037 			       msg->rsp_size - 4);
4038 			if (deliver_response(intf, recv_msg))
4039 				ipmi_inc_stat(intf, unhandled_commands);
4040 			else
4041 				ipmi_inc_stat(intf, handled_commands);
4042 		}
4043 	}
4044 
4045 	return rv;
4046 }
4047 
4048 static int handle_ipmb_direct_rcv_rsp(struct ipmi_smi *intf,
4049 				      struct ipmi_smi_msg *msg)
4050 {
4051 	struct ipmi_recv_msg *recv_msg;
4052 	struct ipmi_ipmb_direct_addr *daddr;
4053 
4054 	recv_msg = msg->user_data;
4055 	if (recv_msg == NULL) {
4056 		dev_warn(intf->si_dev,
4057 			 "IPMI direct message received with no owner. This could be because of a malformed message, or because of a hardware error.  Contact your hardware vendor for assistance.\n");
4058 		return 0;
4059 	}
4060 
4061 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
4062 	recv_msg->msgid = msg->msgid;
4063 	daddr = (struct ipmi_ipmb_direct_addr *) &recv_msg->addr;
4064 	daddr->addr_type = IPMI_IPMB_DIRECT_ADDR_TYPE;
4065 	daddr->channel = 0;
4066 	daddr->slave_addr = msg->rsp[1];
4067 	daddr->rq_lun = msg->rsp[0] & 3;
4068 	daddr->rs_lun = msg->rsp[2] & 3;
4069 	recv_msg->msg.netfn = msg->rsp[0] >> 2;
4070 	recv_msg->msg.cmd = msg->rsp[3];
4071 	memcpy(recv_msg->msg_data, &msg->rsp[4], msg->rsp_size - 4);
4072 	recv_msg->msg.data = recv_msg->msg_data;
4073 	recv_msg->msg.data_len = msg->rsp_size - 4;
4074 	deliver_local_response(intf, recv_msg);
4075 
4076 	return 0;
4077 }
4078 
4079 static int handle_lan_get_msg_rsp(struct ipmi_smi *intf,
4080 				  struct ipmi_smi_msg *msg)
4081 {
4082 	struct ipmi_lan_addr  lan_addr;
4083 	struct ipmi_recv_msg  *recv_msg;
4084 
4085 
4086 	/*
4087 	 * This is 13, not 12, because the response must contain a
4088 	 * completion code.
4089 	 */
4090 	if (msg->rsp_size < 13) {
4091 		/* Message not big enough, just ignore it. */
4092 		ipmi_inc_stat(intf, invalid_lan_responses);
4093 		return 0;
4094 	}
4095 
4096 	if (msg->rsp[2] != 0) {
4097 		/* An error getting the response, just ignore it. */
4098 		return 0;
4099 	}
4100 
4101 	lan_addr.addr_type = IPMI_LAN_ADDR_TYPE;
4102 	lan_addr.session_handle = msg->rsp[4];
4103 	lan_addr.remote_SWID = msg->rsp[8];
4104 	lan_addr.local_SWID = msg->rsp[5];
4105 	lan_addr.channel = msg->rsp[3] & 0x0f;
4106 	lan_addr.privilege = msg->rsp[3] >> 4;
4107 	lan_addr.lun = msg->rsp[9] & 3;
4108 
4109 	/*
4110 	 * It's a response from a remote entity.  Look up the sequence
4111 	 * number and handle the response.
4112 	 */
4113 	if (intf_find_seq(intf,
4114 			  msg->rsp[9] >> 2,
4115 			  msg->rsp[3] & 0x0f,
4116 			  msg->rsp[10],
4117 			  (msg->rsp[6] >> 2) & (~1),
4118 			  (struct ipmi_addr *) &lan_addr,
4119 			  &recv_msg)) {
4120 		/*
4121 		 * We were unable to find the sequence number,
4122 		 * so just nuke the message.
4123 		 */
4124 		ipmi_inc_stat(intf, unhandled_lan_responses);
4125 		return 0;
4126 	}
4127 
4128 	memcpy(recv_msg->msg_data, &msg->rsp[11], msg->rsp_size - 11);
4129 	/*
4130 	 * The other fields matched, so no need to set them, except
4131 	 * for netfn, which needs to be the response that was
4132 	 * returned, not the request value.
4133 	 */
4134 	recv_msg->msg.netfn = msg->rsp[6] >> 2;
4135 	recv_msg->msg.data = recv_msg->msg_data;
4136 	recv_msg->msg.data_len = msg->rsp_size - 12;
4137 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
4138 	if (deliver_response(intf, recv_msg))
4139 		ipmi_inc_stat(intf, unhandled_lan_responses);
4140 	else
4141 		ipmi_inc_stat(intf, handled_lan_responses);
4142 
4143 	return 0;
4144 }
4145 
4146 static int handle_lan_get_msg_cmd(struct ipmi_smi *intf,
4147 				  struct ipmi_smi_msg *msg)
4148 {
4149 	struct cmd_rcvr          *rcvr;
4150 	int                      rv = 0;
4151 	unsigned char            netfn;
4152 	unsigned char            cmd;
4153 	unsigned char            chan;
4154 	struct ipmi_user         *user = NULL;
4155 	struct ipmi_lan_addr     *lan_addr;
4156 	struct ipmi_recv_msg     *recv_msg;
4157 
4158 	if (msg->rsp_size < 12) {
4159 		/* Message not big enough, just ignore it. */
4160 		ipmi_inc_stat(intf, invalid_commands);
4161 		return 0;
4162 	}
4163 
4164 	if (msg->rsp[2] != 0) {
4165 		/* An error getting the response, just ignore it. */
4166 		return 0;
4167 	}
4168 
4169 	netfn = msg->rsp[6] >> 2;
4170 	cmd = msg->rsp[10];
4171 	chan = msg->rsp[3] & 0xf;
4172 
4173 	rcu_read_lock();
4174 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
4175 	if (rcvr) {
4176 		user = rcvr->user;
4177 		kref_get(&user->refcount);
4178 	} else
4179 		user = NULL;
4180 	rcu_read_unlock();
4181 
4182 	if (user == NULL) {
4183 		/* We didn't find a user, just give up. */
4184 		ipmi_inc_stat(intf, unhandled_commands);
4185 
4186 		/*
4187 		 * Don't do anything with these messages, just allow
4188 		 * them to be freed.
4189 		 */
4190 		rv = 0;
4191 	} else {
4192 		recv_msg = ipmi_alloc_recv_msg();
4193 		if (!recv_msg) {
4194 			/*
4195 			 * We couldn't allocate memory for the
4196 			 * message, so requeue it for handling later.
4197 			 */
4198 			rv = 1;
4199 			kref_put(&user->refcount, free_ipmi_user);
4200 		} else {
4201 			/* Extract the source address from the data. */
4202 			lan_addr = (struct ipmi_lan_addr *) &recv_msg->addr;
4203 			lan_addr->addr_type = IPMI_LAN_ADDR_TYPE;
4204 			lan_addr->session_handle = msg->rsp[4];
4205 			lan_addr->remote_SWID = msg->rsp[8];
4206 			lan_addr->local_SWID = msg->rsp[5];
4207 			lan_addr->lun = msg->rsp[9] & 3;
4208 			lan_addr->channel = msg->rsp[3] & 0xf;
4209 			lan_addr->privilege = msg->rsp[3] >> 4;
4210 
4211 			/*
4212 			 * Extract the rest of the message information
4213 			 * from the IPMB header.
4214 			 */
4215 			recv_msg->user = user;
4216 			recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
4217 			recv_msg->msgid = msg->rsp[9] >> 2;
4218 			recv_msg->msg.netfn = msg->rsp[6] >> 2;
4219 			recv_msg->msg.cmd = msg->rsp[10];
4220 			recv_msg->msg.data = recv_msg->msg_data;
4221 
4222 			/*
4223 			 * We chop off 12, not 11 bytes because the checksum
4224 			 * at the end also needs to be removed.
4225 			 */
4226 			recv_msg->msg.data_len = msg->rsp_size - 12;
4227 			memcpy(recv_msg->msg_data, &msg->rsp[11],
4228 			       msg->rsp_size - 12);
4229 			if (deliver_response(intf, recv_msg))
4230 				ipmi_inc_stat(intf, unhandled_commands);
4231 			else
4232 				ipmi_inc_stat(intf, handled_commands);
4233 		}
4234 	}
4235 
4236 	return rv;
4237 }
4238 
4239 /*
4240  * This routine will handle "Get Message" command responses with
4241  * channels that use an OEM Medium. The message format belongs to
4242  * the OEM.  See IPMI 2.0 specification, Chapter 6 and
4243  * Chapter 22, sections 22.6 and 22.24 for more details.
4244  */
4245 static int handle_oem_get_msg_cmd(struct ipmi_smi *intf,
4246 				  struct ipmi_smi_msg *msg)
4247 {
4248 	struct cmd_rcvr       *rcvr;
4249 	int                   rv = 0;
4250 	unsigned char         netfn;
4251 	unsigned char         cmd;
4252 	unsigned char         chan;
4253 	struct ipmi_user *user = NULL;
4254 	struct ipmi_system_interface_addr *smi_addr;
4255 	struct ipmi_recv_msg  *recv_msg;
4256 
4257 	/*
4258 	 * We expect the OEM SW to perform error checking
4259 	 * so we just do some basic sanity checks
4260 	 */
4261 	if (msg->rsp_size < 4) {
4262 		/* Message not big enough, just ignore it. */
4263 		ipmi_inc_stat(intf, invalid_commands);
4264 		return 0;
4265 	}
4266 
4267 	if (msg->rsp[2] != 0) {
4268 		/* An error getting the response, just ignore it. */
4269 		return 0;
4270 	}
4271 
4272 	/*
4273 	 * This is an OEM Message so the OEM needs to know how
4274 	 * handle the message. We do no interpretation.
4275 	 */
4276 	netfn = msg->rsp[0] >> 2;
4277 	cmd = msg->rsp[1];
4278 	chan = msg->rsp[3] & 0xf;
4279 
4280 	rcu_read_lock();
4281 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
4282 	if (rcvr) {
4283 		user = rcvr->user;
4284 		kref_get(&user->refcount);
4285 	} else
4286 		user = NULL;
4287 	rcu_read_unlock();
4288 
4289 	if (user == NULL) {
4290 		/* We didn't find a user, just give up. */
4291 		ipmi_inc_stat(intf, unhandled_commands);
4292 
4293 		/*
4294 		 * Don't do anything with these messages, just allow
4295 		 * them to be freed.
4296 		 */
4297 
4298 		rv = 0;
4299 	} else {
4300 		recv_msg = ipmi_alloc_recv_msg();
4301 		if (!recv_msg) {
4302 			/*
4303 			 * We couldn't allocate memory for the
4304 			 * message, so requeue it for handling
4305 			 * later.
4306 			 */
4307 			rv = 1;
4308 			kref_put(&user->refcount, free_ipmi_user);
4309 		} else {
4310 			/*
4311 			 * OEM Messages are expected to be delivered via
4312 			 * the system interface to SMS software.  We might
4313 			 * need to visit this again depending on OEM
4314 			 * requirements
4315 			 */
4316 			smi_addr = ((struct ipmi_system_interface_addr *)
4317 				    &recv_msg->addr);
4318 			smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4319 			smi_addr->channel = IPMI_BMC_CHANNEL;
4320 			smi_addr->lun = msg->rsp[0] & 3;
4321 
4322 			recv_msg->user = user;
4323 			recv_msg->user_msg_data = NULL;
4324 			recv_msg->recv_type = IPMI_OEM_RECV_TYPE;
4325 			recv_msg->msg.netfn = msg->rsp[0] >> 2;
4326 			recv_msg->msg.cmd = msg->rsp[1];
4327 			recv_msg->msg.data = recv_msg->msg_data;
4328 
4329 			/*
4330 			 * The message starts at byte 4 which follows the
4331 			 * Channel Byte in the "GET MESSAGE" command
4332 			 */
4333 			recv_msg->msg.data_len = msg->rsp_size - 4;
4334 			memcpy(recv_msg->msg_data, &msg->rsp[4],
4335 			       msg->rsp_size - 4);
4336 			if (deliver_response(intf, recv_msg))
4337 				ipmi_inc_stat(intf, unhandled_commands);
4338 			else
4339 				ipmi_inc_stat(intf, handled_commands);
4340 		}
4341 	}
4342 
4343 	return rv;
4344 }
4345 
4346 static void copy_event_into_recv_msg(struct ipmi_recv_msg *recv_msg,
4347 				     struct ipmi_smi_msg  *msg)
4348 {
4349 	struct ipmi_system_interface_addr *smi_addr;
4350 
4351 	recv_msg->msgid = 0;
4352 	smi_addr = (struct ipmi_system_interface_addr *) &recv_msg->addr;
4353 	smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4354 	smi_addr->channel = IPMI_BMC_CHANNEL;
4355 	smi_addr->lun = msg->rsp[0] & 3;
4356 	recv_msg->recv_type = IPMI_ASYNC_EVENT_RECV_TYPE;
4357 	recv_msg->msg.netfn = msg->rsp[0] >> 2;
4358 	recv_msg->msg.cmd = msg->rsp[1];
4359 	memcpy(recv_msg->msg_data, &msg->rsp[3], msg->rsp_size - 3);
4360 	recv_msg->msg.data = recv_msg->msg_data;
4361 	recv_msg->msg.data_len = msg->rsp_size - 3;
4362 }
4363 
4364 static int handle_read_event_rsp(struct ipmi_smi *intf,
4365 				 struct ipmi_smi_msg *msg)
4366 {
4367 	struct ipmi_recv_msg *recv_msg, *recv_msg2;
4368 	struct list_head     msgs;
4369 	struct ipmi_user     *user;
4370 	int rv = 0, deliver_count = 0;
4371 
4372 	if (msg->rsp_size < 19) {
4373 		/* Message is too small to be an IPMB event. */
4374 		ipmi_inc_stat(intf, invalid_events);
4375 		return 0;
4376 	}
4377 
4378 	if (msg->rsp[2] != 0) {
4379 		/* An error getting the event, just ignore it. */
4380 		return 0;
4381 	}
4382 
4383 	INIT_LIST_HEAD(&msgs);
4384 
4385 	mutex_lock(&intf->events_mutex);
4386 
4387 	ipmi_inc_stat(intf, events);
4388 
4389 	/*
4390 	 * Allocate and fill in one message for every user that is
4391 	 * getting events.
4392 	 */
4393 	mutex_lock(&intf->users_mutex);
4394 	list_for_each_entry(user, &intf->users, link) {
4395 		if (!user->gets_events)
4396 			continue;
4397 
4398 		recv_msg = ipmi_alloc_recv_msg();
4399 		if (!recv_msg) {
4400 			mutex_unlock(&intf->users_mutex);
4401 			list_for_each_entry_safe(recv_msg, recv_msg2, &msgs,
4402 						 link) {
4403 				user = recv_msg->user;
4404 				list_del(&recv_msg->link);
4405 				ipmi_free_recv_msg(recv_msg);
4406 				kref_put(&user->refcount, free_ipmi_user);
4407 			}
4408 			/*
4409 			 * We couldn't allocate memory for the
4410 			 * message, so requeue it for handling
4411 			 * later.
4412 			 */
4413 			rv = 1;
4414 			goto out;
4415 		}
4416 
4417 		deliver_count++;
4418 
4419 		copy_event_into_recv_msg(recv_msg, msg);
4420 		recv_msg->user = user;
4421 		kref_get(&user->refcount);
4422 		list_add_tail(&recv_msg->link, &msgs);
4423 	}
4424 	mutex_unlock(&intf->users_mutex);
4425 
4426 	if (deliver_count) {
4427 		/* Now deliver all the messages. */
4428 		list_for_each_entry_safe(recv_msg, recv_msg2, &msgs, link) {
4429 			list_del(&recv_msg->link);
4430 			deliver_local_response(intf, recv_msg);
4431 		}
4432 	} else if (intf->waiting_events_count < MAX_EVENTS_IN_QUEUE) {
4433 		/*
4434 		 * No one to receive the message, put it in queue if there's
4435 		 * not already too many things in the queue.
4436 		 */
4437 		recv_msg = ipmi_alloc_recv_msg();
4438 		if (!recv_msg) {
4439 			/*
4440 			 * We couldn't allocate memory for the
4441 			 * message, so requeue it for handling
4442 			 * later.
4443 			 */
4444 			rv = 1;
4445 			goto out;
4446 		}
4447 
4448 		copy_event_into_recv_msg(recv_msg, msg);
4449 		list_add_tail(&recv_msg->link, &intf->waiting_events);
4450 		intf->waiting_events_count++;
4451 	} else if (!intf->event_msg_printed) {
4452 		/*
4453 		 * There's too many things in the queue, discard this
4454 		 * message.
4455 		 */
4456 		dev_warn(intf->si_dev,
4457 			 "Event queue full, discarding incoming events\n");
4458 		intf->event_msg_printed = 1;
4459 	}
4460 
4461  out:
4462 	mutex_unlock(&intf->events_mutex);
4463 
4464 	return rv;
4465 }
4466 
4467 static int handle_bmc_rsp(struct ipmi_smi *intf,
4468 			  struct ipmi_smi_msg *msg)
4469 {
4470 	struct ipmi_recv_msg *recv_msg;
4471 	struct ipmi_system_interface_addr *smi_addr;
4472 
4473 	recv_msg = msg->user_data;
4474 	if (recv_msg == NULL) {
4475 		dev_warn(intf->si_dev,
4476 			 "IPMI SMI message received with no owner. This could be because of a malformed message, or because of a hardware error.  Contact your hardware vendor for assistance.\n");
4477 		return 0;
4478 	}
4479 
4480 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
4481 	recv_msg->msgid = msg->msgid;
4482 	smi_addr = ((struct ipmi_system_interface_addr *)
4483 		    &recv_msg->addr);
4484 	smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4485 	smi_addr->channel = IPMI_BMC_CHANNEL;
4486 	smi_addr->lun = msg->rsp[0] & 3;
4487 	recv_msg->msg.netfn = msg->rsp[0] >> 2;
4488 	recv_msg->msg.cmd = msg->rsp[1];
4489 	memcpy(recv_msg->msg_data, &msg->rsp[2], msg->rsp_size - 2);
4490 	recv_msg->msg.data = recv_msg->msg_data;
4491 	recv_msg->msg.data_len = msg->rsp_size - 2;
4492 	deliver_local_response(intf, recv_msg);
4493 
4494 	return 0;
4495 }
4496 
4497 /*
4498  * Handle a received message.  Return 1 if the message should be requeued,
4499  * 0 if the message should be freed, or -1 if the message should not
4500  * be freed or requeued.
4501  */
4502 static int handle_one_recv_msg(struct ipmi_smi *intf,
4503 			       struct ipmi_smi_msg *msg)
4504 {
4505 	int requeue = 0;
4506 	int chan;
4507 	unsigned char cc;
4508 	bool is_cmd = !((msg->rsp[0] >> 2) & 1);
4509 
4510 	dev_dbg(intf->si_dev, "Recv: %*ph\n", msg->rsp_size, msg->rsp);
4511 
4512 	if (msg->rsp_size < 2) {
4513 		/* Message is too small to be correct. */
4514 		dev_warn(intf->si_dev,
4515 			 "BMC returned too small a message for netfn %x cmd %x, got %d bytes\n",
4516 			 (msg->data[0] >> 2) | 1, msg->data[1], msg->rsp_size);
4517 
4518 return_unspecified:
4519 		/* Generate an error response for the message. */
4520 		msg->rsp[0] = msg->data[0] | (1 << 2);
4521 		msg->rsp[1] = msg->data[1];
4522 		msg->rsp[2] = IPMI_ERR_UNSPECIFIED;
4523 		msg->rsp_size = 3;
4524 	} else if (msg->type == IPMI_SMI_MSG_TYPE_IPMB_DIRECT) {
4525 		/* commands must have at least 4 bytes, responses 5. */
4526 		if (is_cmd && (msg->rsp_size < 4)) {
4527 			ipmi_inc_stat(intf, invalid_commands);
4528 			goto out;
4529 		}
4530 		if (!is_cmd && (msg->rsp_size < 5)) {
4531 			ipmi_inc_stat(intf, invalid_ipmb_responses);
4532 			/* Construct a valid error response. */
4533 			msg->rsp[0] = msg->data[0] & 0xfc; /* NetFN */
4534 			msg->rsp[0] |= (1 << 2); /* Make it a response */
4535 			msg->rsp[0] |= msg->data[2] & 3; /* rqLUN */
4536 			msg->rsp[1] = msg->data[1]; /* Addr */
4537 			msg->rsp[2] = msg->data[2] & 0xfc; /* rqSeq */
4538 			msg->rsp[2] |= msg->data[0] & 0x3; /* rsLUN */
4539 			msg->rsp[3] = msg->data[3]; /* Cmd */
4540 			msg->rsp[4] = IPMI_ERR_UNSPECIFIED;
4541 			msg->rsp_size = 5;
4542 		}
4543 	} else if ((msg->data_size >= 2)
4544 	    && (msg->data[0] == (IPMI_NETFN_APP_REQUEST << 2))
4545 	    && (msg->data[1] == IPMI_SEND_MSG_CMD)
4546 	    && (msg->user_data == NULL)) {
4547 
4548 		if (intf->in_shutdown)
4549 			goto out;
4550 
4551 		/*
4552 		 * This is the local response to a command send, start
4553 		 * the timer for these.  The user_data will not be
4554 		 * NULL if this is a response send, and we will let
4555 		 * response sends just go through.
4556 		 */
4557 
4558 		/*
4559 		 * Check for errors, if we get certain errors (ones
4560 		 * that mean basically we can try again later), we
4561 		 * ignore them and start the timer.  Otherwise we
4562 		 * report the error immediately.
4563 		 */
4564 		if ((msg->rsp_size >= 3) && (msg->rsp[2] != 0)
4565 		    && (msg->rsp[2] != IPMI_NODE_BUSY_ERR)
4566 		    && (msg->rsp[2] != IPMI_LOST_ARBITRATION_ERR)
4567 		    && (msg->rsp[2] != IPMI_BUS_ERR)
4568 		    && (msg->rsp[2] != IPMI_NAK_ON_WRITE_ERR)) {
4569 			int ch = msg->rsp[3] & 0xf;
4570 			struct ipmi_channel *chans;
4571 
4572 			/* Got an error sending the message, handle it. */
4573 
4574 			chans = READ_ONCE(intf->channel_list)->c;
4575 			if ((chans[ch].medium == IPMI_CHANNEL_MEDIUM_8023LAN)
4576 			    || (chans[ch].medium == IPMI_CHANNEL_MEDIUM_ASYNC))
4577 				ipmi_inc_stat(intf, sent_lan_command_errs);
4578 			else
4579 				ipmi_inc_stat(intf, sent_ipmb_command_errs);
4580 			intf_err_seq(intf, msg->msgid, msg->rsp[2]);
4581 		} else
4582 			/* The message was sent, start the timer. */
4583 			intf_start_seq_timer(intf, msg->msgid);
4584 		requeue = 0;
4585 		goto out;
4586 	} else if (((msg->rsp[0] >> 2) != ((msg->data[0] >> 2) | 1))
4587 		   || (msg->rsp[1] != msg->data[1])) {
4588 		/*
4589 		 * The NetFN and Command in the response is not even
4590 		 * marginally correct.
4591 		 */
4592 		dev_warn(intf->si_dev,
4593 			 "BMC returned incorrect response, expected netfn %x cmd %x, got netfn %x cmd %x\n",
4594 			 (msg->data[0] >> 2) | 1, msg->data[1],
4595 			 msg->rsp[0] >> 2, msg->rsp[1]);
4596 
4597 		goto return_unspecified;
4598 	}
4599 
4600 	if (msg->type == IPMI_SMI_MSG_TYPE_IPMB_DIRECT) {
4601 		if ((msg->data[0] >> 2) & 1) {
4602 			/* It's a response to a sent response. */
4603 			chan = 0;
4604 			cc = msg->rsp[4];
4605 			goto process_response_response;
4606 		}
4607 		if (is_cmd)
4608 			requeue = handle_ipmb_direct_rcv_cmd(intf, msg);
4609 		else
4610 			requeue = handle_ipmb_direct_rcv_rsp(intf, msg);
4611 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4612 		   && (msg->rsp[1] == IPMI_SEND_MSG_CMD)
4613 		   && (msg->user_data != NULL)) {
4614 		/*
4615 		 * It's a response to a response we sent.  For this we
4616 		 * deliver a send message response to the user.
4617 		 */
4618 		struct ipmi_recv_msg *recv_msg;
4619 
4620 		chan = msg->data[2] & 0x0f;
4621 		if (chan >= IPMI_MAX_CHANNELS)
4622 			/* Invalid channel number */
4623 			goto out;
4624 		cc = msg->rsp[2];
4625 
4626 process_response_response:
4627 		recv_msg = msg->user_data;
4628 
4629 		requeue = 0;
4630 		if (!recv_msg)
4631 			goto out;
4632 
4633 		recv_msg->recv_type = IPMI_RESPONSE_RESPONSE_TYPE;
4634 		recv_msg->msg.data = recv_msg->msg_data;
4635 		recv_msg->msg_data[0] = cc;
4636 		recv_msg->msg.data_len = 1;
4637 		deliver_local_response(intf, recv_msg);
4638 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4639 		   && (msg->rsp[1] == IPMI_GET_MSG_CMD)) {
4640 		struct ipmi_channel   *chans;
4641 
4642 		/* It's from the receive queue. */
4643 		chan = msg->rsp[3] & 0xf;
4644 		if (chan >= IPMI_MAX_CHANNELS) {
4645 			/* Invalid channel number */
4646 			requeue = 0;
4647 			goto out;
4648 		}
4649 
4650 		/*
4651 		 * We need to make sure the channels have been initialized.
4652 		 * The channel_handler routine will set the "curr_channel"
4653 		 * equal to or greater than IPMI_MAX_CHANNELS when all the
4654 		 * channels for this interface have been initialized.
4655 		 */
4656 		if (!intf->channels_ready) {
4657 			requeue = 0; /* Throw the message away */
4658 			goto out;
4659 		}
4660 
4661 		chans = READ_ONCE(intf->channel_list)->c;
4662 
4663 		switch (chans[chan].medium) {
4664 		case IPMI_CHANNEL_MEDIUM_IPMB:
4665 			if (msg->rsp[4] & 0x04) {
4666 				/*
4667 				 * It's a response, so find the
4668 				 * requesting message and send it up.
4669 				 */
4670 				requeue = handle_ipmb_get_msg_rsp(intf, msg);
4671 			} else {
4672 				/*
4673 				 * It's a command to the SMS from some other
4674 				 * entity.  Handle that.
4675 				 */
4676 				requeue = handle_ipmb_get_msg_cmd(intf, msg);
4677 			}
4678 			break;
4679 
4680 		case IPMI_CHANNEL_MEDIUM_8023LAN:
4681 		case IPMI_CHANNEL_MEDIUM_ASYNC:
4682 			if (msg->rsp[6] & 0x04) {
4683 				/*
4684 				 * It's a response, so find the
4685 				 * requesting message and send it up.
4686 				 */
4687 				requeue = handle_lan_get_msg_rsp(intf, msg);
4688 			} else {
4689 				/*
4690 				 * It's a command to the SMS from some other
4691 				 * entity.  Handle that.
4692 				 */
4693 				requeue = handle_lan_get_msg_cmd(intf, msg);
4694 			}
4695 			break;
4696 
4697 		default:
4698 			/* Check for OEM Channels.  Clients had better
4699 			   register for these commands. */
4700 			if ((chans[chan].medium >= IPMI_CHANNEL_MEDIUM_OEM_MIN)
4701 			    && (chans[chan].medium
4702 				<= IPMI_CHANNEL_MEDIUM_OEM_MAX)) {
4703 				requeue = handle_oem_get_msg_cmd(intf, msg);
4704 			} else {
4705 				/*
4706 				 * We don't handle the channel type, so just
4707 				 * free the message.
4708 				 */
4709 				requeue = 0;
4710 			}
4711 		}
4712 
4713 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4714 		   && (msg->rsp[1] == IPMI_READ_EVENT_MSG_BUFFER_CMD)) {
4715 		/* It's an asynchronous event. */
4716 		requeue = handle_read_event_rsp(intf, msg);
4717 	} else {
4718 		/* It's a response from the local BMC. */
4719 		requeue = handle_bmc_rsp(intf, msg);
4720 	}
4721 
4722  out:
4723 	return requeue;
4724 }
4725 
4726 /*
4727  * If there are messages in the queue or pretimeouts, handle them.
4728  */
4729 static void handle_new_recv_msgs(struct ipmi_smi *intf)
4730 {
4731 	struct ipmi_smi_msg *smi_msg;
4732 	unsigned long flags = 0;
4733 	int rv;
4734 	int run_to_completion = READ_ONCE(intf->run_to_completion);
4735 
4736 	/* See if any waiting messages need to be processed. */
4737 	if (!run_to_completion)
4738 		spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4739 	while (!list_empty(&intf->waiting_rcv_msgs)) {
4740 		smi_msg = list_entry(intf->waiting_rcv_msgs.next,
4741 				     struct ipmi_smi_msg, link);
4742 		list_del(&smi_msg->link);
4743 		if (!run_to_completion)
4744 			spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
4745 					       flags);
4746 		rv = handle_one_recv_msg(intf, smi_msg);
4747 		if (!run_to_completion)
4748 			spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4749 		if (rv > 0) {
4750 			/*
4751 			 * To preserve message order, quit if we
4752 			 * can't handle a message.  Add the message
4753 			 * back at the head, this is safe because this
4754 			 * workqueue is the only thing that pulls the
4755 			 * messages.
4756 			 */
4757 			list_add(&smi_msg->link, &intf->waiting_rcv_msgs);
4758 			break;
4759 		} else {
4760 			if (rv == 0)
4761 				/* Message handled */
4762 				ipmi_free_smi_msg(smi_msg);
4763 			/* If rv < 0, fatal error, del but don't free. */
4764 		}
4765 	}
4766 	if (!run_to_completion)
4767 		spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock, flags);
4768 }
4769 
4770 static void smi_work(struct work_struct *t)
4771 {
4772 	unsigned long flags = 0; /* keep us warning-free. */
4773 	struct ipmi_smi *intf = from_work(intf, t, smi_work);
4774 	int run_to_completion = READ_ONCE(intf->run_to_completion);
4775 	struct ipmi_smi_msg *newmsg = NULL;
4776 	struct ipmi_recv_msg *msg, *msg2;
4777 
4778 	/*
4779 	 * Start the next message if available.
4780 	 *
4781 	 * Do this here, not in the actual receiver, because we may deadlock
4782 	 * because the lower layer is allowed to hold locks while calling
4783 	 * message delivery.
4784 	 */
4785 
4786 	if (!run_to_completion)
4787 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
4788 	if (intf->curr_msg == NULL && !intf->in_shutdown) {
4789 		struct list_head *entry = NULL;
4790 
4791 		/* Pick the high priority queue first. */
4792 		if (!list_empty(&intf->hp_xmit_msgs))
4793 			entry = intf->hp_xmit_msgs.next;
4794 		else if (!list_empty(&intf->xmit_msgs))
4795 			entry = intf->xmit_msgs.next;
4796 
4797 		if (entry) {
4798 			list_del(entry);
4799 			newmsg = list_entry(entry, struct ipmi_smi_msg, link);
4800 			intf->curr_msg = newmsg;
4801 		}
4802 	}
4803 	if (!run_to_completion)
4804 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
4805 
4806 	if (newmsg)
4807 		intf->handlers->sender(intf->send_info, newmsg);
4808 
4809 	handle_new_recv_msgs(intf);
4810 
4811 	/*
4812 	 * If the pretimout count is non-zero, decrement one from it and
4813 	 * deliver pretimeouts to all the users.
4814 	 */
4815 	if (atomic_add_unless(&intf->watchdog_pretimeouts_to_deliver, -1, 0)) {
4816 		struct ipmi_user *user;
4817 
4818 		mutex_lock(&intf->users_mutex);
4819 		list_for_each_entry(user, &intf->users, link) {
4820 			if (user->handler->ipmi_watchdog_pretimeout)
4821 				user->handler->ipmi_watchdog_pretimeout(
4822 					user->handler_data);
4823 		}
4824 		mutex_unlock(&intf->users_mutex);
4825 	}
4826 
4827 	mutex_lock(&intf->user_msgs_mutex);
4828 	list_for_each_entry_safe(msg, msg2, &intf->user_msgs, link) {
4829 		struct ipmi_user *user = msg->user;
4830 
4831 		list_del(&msg->link);
4832 		atomic_dec(&user->nr_msgs);
4833 		user->handler->ipmi_recv_hndl(msg, user->handler_data);
4834 		release_ipmi_user(user);
4835 	}
4836 	mutex_unlock(&intf->user_msgs_mutex);
4837 }
4838 
4839 /* Handle a new message from the lower layer. */
4840 void ipmi_smi_msg_received(struct ipmi_smi *intf,
4841 			   struct ipmi_smi_msg *msg)
4842 {
4843 	unsigned long flags = 0; /* keep us warning-free. */
4844 	int run_to_completion = READ_ONCE(intf->run_to_completion);
4845 
4846 	/*
4847 	 * To preserve message order, we keep a queue and deliver from
4848 	 * a workqueue.
4849 	 */
4850 	if (!run_to_completion)
4851 		spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4852 	list_add_tail(&msg->link, &intf->waiting_rcv_msgs);
4853 	if (!run_to_completion)
4854 		spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
4855 				       flags);
4856 
4857 	if (!run_to_completion)
4858 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
4859 	/*
4860 	 * We can get an asynchronous event or receive message in addition
4861 	 * to commands we send.
4862 	 */
4863 	if (msg == intf->curr_msg)
4864 		intf->curr_msg = NULL;
4865 	if (!run_to_completion)
4866 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
4867 
4868 	if (run_to_completion)
4869 		smi_work(&intf->smi_work);
4870 	else
4871 		queue_work(system_wq, &intf->smi_work);
4872 }
4873 EXPORT_SYMBOL(ipmi_smi_msg_received);
4874 
4875 void ipmi_smi_watchdog_pretimeout(struct ipmi_smi *intf)
4876 {
4877 	if (intf->in_shutdown)
4878 		return;
4879 
4880 	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 1);
4881 	queue_work(system_wq, &intf->smi_work);
4882 }
4883 EXPORT_SYMBOL(ipmi_smi_watchdog_pretimeout);
4884 
4885 static struct ipmi_smi_msg *
4886 smi_from_recv_msg(struct ipmi_smi *intf, struct ipmi_recv_msg *recv_msg,
4887 		  unsigned char seq, long seqid)
4888 {
4889 	struct ipmi_smi_msg *smi_msg = ipmi_alloc_smi_msg();
4890 	if (!smi_msg)
4891 		/*
4892 		 * If we can't allocate the message, then just return, we
4893 		 * get 4 retries, so this should be ok.
4894 		 */
4895 		return NULL;
4896 
4897 	memcpy(smi_msg->data, recv_msg->msg.data, recv_msg->msg.data_len);
4898 	smi_msg->data_size = recv_msg->msg.data_len;
4899 	smi_msg->msgid = STORE_SEQ_IN_MSGID(seq, seqid);
4900 
4901 	dev_dbg(intf->si_dev, "Resend: %*ph\n",
4902 		smi_msg->data_size, smi_msg->data);
4903 
4904 	return smi_msg;
4905 }
4906 
4907 static void check_msg_timeout(struct ipmi_smi *intf, struct seq_table *ent,
4908 			      struct list_head *timeouts,
4909 			      unsigned long timeout_period,
4910 			      int slot, unsigned long *flags,
4911 			      bool *need_timer)
4912 {
4913 	struct ipmi_recv_msg *msg;
4914 
4915 	if (intf->in_shutdown)
4916 		return;
4917 
4918 	if (!ent->inuse)
4919 		return;
4920 
4921 	if (timeout_period < ent->timeout) {
4922 		ent->timeout -= timeout_period;
4923 		*need_timer = true;
4924 		return;
4925 	}
4926 
4927 	if (ent->retries_left == 0) {
4928 		/* The message has used all its retries. */
4929 		ent->inuse = 0;
4930 		smi_remove_watch(intf, IPMI_WATCH_MASK_CHECK_MESSAGES);
4931 		msg = ent->recv_msg;
4932 		list_add_tail(&msg->link, timeouts);
4933 		if (ent->broadcast)
4934 			ipmi_inc_stat(intf, timed_out_ipmb_broadcasts);
4935 		else if (is_lan_addr(&ent->recv_msg->addr))
4936 			ipmi_inc_stat(intf, timed_out_lan_commands);
4937 		else
4938 			ipmi_inc_stat(intf, timed_out_ipmb_commands);
4939 	} else {
4940 		struct ipmi_smi_msg *smi_msg;
4941 		/* More retries, send again. */
4942 
4943 		*need_timer = true;
4944 
4945 		/*
4946 		 * Start with the max timer, set to normal timer after
4947 		 * the message is sent.
4948 		 */
4949 		ent->timeout = MAX_MSG_TIMEOUT;
4950 		ent->retries_left--;
4951 		smi_msg = smi_from_recv_msg(intf, ent->recv_msg, slot,
4952 					    ent->seqid);
4953 		if (!smi_msg) {
4954 			if (is_lan_addr(&ent->recv_msg->addr))
4955 				ipmi_inc_stat(intf,
4956 					      dropped_rexmit_lan_commands);
4957 			else
4958 				ipmi_inc_stat(intf,
4959 					      dropped_rexmit_ipmb_commands);
4960 			return;
4961 		}
4962 
4963 		spin_unlock_irqrestore(&intf->seq_lock, *flags);
4964 
4965 		/*
4966 		 * Send the new message.  We send with a zero
4967 		 * priority.  It timed out, I doubt time is that
4968 		 * critical now, and high priority messages are really
4969 		 * only for messages to the local MC, which don't get
4970 		 * resent.
4971 		 */
4972 		if (intf->handlers) {
4973 			if (is_lan_addr(&ent->recv_msg->addr))
4974 				ipmi_inc_stat(intf,
4975 					      retransmitted_lan_commands);
4976 			else
4977 				ipmi_inc_stat(intf,
4978 					      retransmitted_ipmb_commands);
4979 
4980 			smi_send(intf, intf->handlers, smi_msg, 0);
4981 		} else
4982 			ipmi_free_smi_msg(smi_msg);
4983 
4984 		spin_lock_irqsave(&intf->seq_lock, *flags);
4985 	}
4986 }
4987 
4988 static bool ipmi_timeout_handler(struct ipmi_smi *intf,
4989 				 unsigned long timeout_period)
4990 {
4991 	struct list_head     timeouts;
4992 	struct ipmi_recv_msg *msg, *msg2;
4993 	unsigned long        flags;
4994 	int                  i;
4995 	bool                 need_timer = false;
4996 
4997 	if (!intf->bmc_registered) {
4998 		kref_get(&intf->refcount);
4999 		if (!schedule_work(&intf->bmc_reg_work)) {
5000 			kref_put(&intf->refcount, intf_free);
5001 			need_timer = true;
5002 		}
5003 	}
5004 
5005 	/*
5006 	 * Go through the seq table and find any messages that
5007 	 * have timed out, putting them in the timeouts
5008 	 * list.
5009 	 */
5010 	INIT_LIST_HEAD(&timeouts);
5011 	spin_lock_irqsave(&intf->seq_lock, flags);
5012 	if (intf->ipmb_maintenance_mode_timeout) {
5013 		if (intf->ipmb_maintenance_mode_timeout <= timeout_period)
5014 			intf->ipmb_maintenance_mode_timeout = 0;
5015 		else
5016 			intf->ipmb_maintenance_mode_timeout -= timeout_period;
5017 	}
5018 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++)
5019 		check_msg_timeout(intf, &intf->seq_table[i],
5020 				  &timeouts, timeout_period, i,
5021 				  &flags, &need_timer);
5022 	spin_unlock_irqrestore(&intf->seq_lock, flags);
5023 
5024 	list_for_each_entry_safe(msg, msg2, &timeouts, link)
5025 		deliver_err_response(intf, msg, IPMI_TIMEOUT_COMPLETION_CODE);
5026 
5027 	/*
5028 	 * Maintenance mode handling.  Check the timeout
5029 	 * optimistically before we claim the lock.  It may
5030 	 * mean a timeout gets missed occasionally, but that
5031 	 * only means the timeout gets extended by one period
5032 	 * in that case.  No big deal, and it avoids the lock
5033 	 * most of the time.
5034 	 */
5035 	if (intf->auto_maintenance_timeout > 0) {
5036 		spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
5037 		if (intf->auto_maintenance_timeout > 0) {
5038 			intf->auto_maintenance_timeout
5039 				-= timeout_period;
5040 			if (!intf->maintenance_mode
5041 			    && (intf->auto_maintenance_timeout <= 0)) {
5042 				intf->maintenance_mode_enable = false;
5043 				maintenance_mode_update(intf);
5044 			}
5045 		}
5046 		spin_unlock_irqrestore(&intf->maintenance_mode_lock,
5047 				       flags);
5048 	}
5049 
5050 	queue_work(system_wq, &intf->smi_work);
5051 
5052 	return need_timer;
5053 }
5054 
5055 static void ipmi_request_event(struct ipmi_smi *intf)
5056 {
5057 	/* No event requests when in maintenance mode. */
5058 	if (intf->maintenance_mode_enable)
5059 		return;
5060 
5061 	if (!intf->in_shutdown)
5062 		intf->handlers->request_events(intf->send_info);
5063 }
5064 
5065 static struct timer_list ipmi_timer;
5066 
5067 static atomic_t stop_operation;
5068 
5069 static void ipmi_timeout_work(struct work_struct *work)
5070 {
5071 	if (atomic_read(&stop_operation))
5072 		return;
5073 
5074 	struct ipmi_smi *intf;
5075 	bool need_timer = false;
5076 
5077 	if (atomic_read(&stop_operation))
5078 		return;
5079 
5080 	mutex_lock(&ipmi_interfaces_mutex);
5081 	list_for_each_entry(intf, &ipmi_interfaces, link) {
5082 		if (atomic_read(&intf->event_waiters)) {
5083 			intf->ticks_to_req_ev--;
5084 			if (intf->ticks_to_req_ev == 0) {
5085 				ipmi_request_event(intf);
5086 				intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
5087 			}
5088 			need_timer = true;
5089 		}
5090 
5091 		need_timer |= ipmi_timeout_handler(intf, IPMI_TIMEOUT_TIME);
5092 	}
5093 	mutex_unlock(&ipmi_interfaces_mutex);
5094 
5095 	if (need_timer)
5096 		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
5097 }
5098 
5099 static DECLARE_WORK(ipmi_timer_work, ipmi_timeout_work);
5100 
5101 static void ipmi_timeout(struct timer_list *unused)
5102 {
5103 	if (atomic_read(&stop_operation))
5104 		return;
5105 
5106 	queue_work(system_wq, &ipmi_timer_work);
5107 }
5108 
5109 static void need_waiter(struct ipmi_smi *intf)
5110 {
5111 	/* Racy, but worst case we start the timer twice. */
5112 	if (!timer_pending(&ipmi_timer))
5113 		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
5114 }
5115 
5116 static atomic_t smi_msg_inuse_count = ATOMIC_INIT(0);
5117 static atomic_t recv_msg_inuse_count = ATOMIC_INIT(0);
5118 
5119 static void free_smi_msg(struct ipmi_smi_msg *msg)
5120 {
5121 	atomic_dec(&smi_msg_inuse_count);
5122 	/* Try to keep as much stuff out of the panic path as possible. */
5123 	if (!oops_in_progress)
5124 		kfree(msg);
5125 }
5126 
5127 struct ipmi_smi_msg *ipmi_alloc_smi_msg(void)
5128 {
5129 	struct ipmi_smi_msg *rv;
5130 	rv = kmalloc(sizeof(struct ipmi_smi_msg), GFP_ATOMIC);
5131 	if (rv) {
5132 		rv->done = free_smi_msg;
5133 		rv->user_data = NULL;
5134 		rv->type = IPMI_SMI_MSG_TYPE_NORMAL;
5135 		atomic_inc(&smi_msg_inuse_count);
5136 	}
5137 	return rv;
5138 }
5139 EXPORT_SYMBOL(ipmi_alloc_smi_msg);
5140 
5141 static void free_recv_msg(struct ipmi_recv_msg *msg)
5142 {
5143 	atomic_dec(&recv_msg_inuse_count);
5144 	/* Try to keep as much stuff out of the panic path as possible. */
5145 	if (!oops_in_progress)
5146 		kfree(msg);
5147 }
5148 
5149 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void)
5150 {
5151 	struct ipmi_recv_msg *rv;
5152 
5153 	rv = kmalloc(sizeof(struct ipmi_recv_msg), GFP_ATOMIC);
5154 	if (rv) {
5155 		rv->user = NULL;
5156 		rv->done = free_recv_msg;
5157 		atomic_inc(&recv_msg_inuse_count);
5158 	}
5159 	return rv;
5160 }
5161 
5162 void ipmi_free_recv_msg(struct ipmi_recv_msg *msg)
5163 {
5164 	if (msg->user && !oops_in_progress)
5165 		kref_put(&msg->user->refcount, free_ipmi_user);
5166 	msg->done(msg);
5167 }
5168 EXPORT_SYMBOL(ipmi_free_recv_msg);
5169 
5170 static atomic_t panic_done_count = ATOMIC_INIT(0);
5171 
5172 static void dummy_smi_done_handler(struct ipmi_smi_msg *msg)
5173 {
5174 	atomic_dec(&panic_done_count);
5175 }
5176 
5177 static void dummy_recv_done_handler(struct ipmi_recv_msg *msg)
5178 {
5179 	atomic_dec(&panic_done_count);
5180 }
5181 
5182 /*
5183  * Inside a panic, send a message and wait for a response.
5184  */
5185 static void ipmi_panic_request_and_wait(struct ipmi_smi *intf,
5186 					struct ipmi_addr *addr,
5187 					struct kernel_ipmi_msg *msg)
5188 {
5189 	struct ipmi_smi_msg  smi_msg;
5190 	struct ipmi_recv_msg recv_msg;
5191 	int rv;
5192 
5193 	smi_msg.done = dummy_smi_done_handler;
5194 	recv_msg.done = dummy_recv_done_handler;
5195 	atomic_add(2, &panic_done_count);
5196 	rv = i_ipmi_request(NULL,
5197 			    intf,
5198 			    addr,
5199 			    0,
5200 			    msg,
5201 			    intf,
5202 			    &smi_msg,
5203 			    &recv_msg,
5204 			    0,
5205 			    intf->addrinfo[0].address,
5206 			    intf->addrinfo[0].lun,
5207 			    0, 1); /* Don't retry, and don't wait. */
5208 	if (rv)
5209 		atomic_sub(2, &panic_done_count);
5210 	else if (intf->handlers->flush_messages)
5211 		intf->handlers->flush_messages(intf->send_info);
5212 
5213 	while (atomic_read(&panic_done_count) != 0)
5214 		ipmi_poll(intf);
5215 }
5216 
5217 static void event_receiver_fetcher(struct ipmi_smi *intf,
5218 				   struct ipmi_recv_msg *msg)
5219 {
5220 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
5221 	    && (msg->msg.netfn == IPMI_NETFN_SENSOR_EVENT_RESPONSE)
5222 	    && (msg->msg.cmd == IPMI_GET_EVENT_RECEIVER_CMD)
5223 	    && (msg->msg.data[0] == IPMI_CC_NO_ERROR)) {
5224 		/* A get event receiver command, save it. */
5225 		intf->event_receiver = msg->msg.data[1];
5226 		intf->event_receiver_lun = msg->msg.data[2] & 0x3;
5227 	}
5228 }
5229 
5230 static void device_id_fetcher(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
5231 {
5232 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
5233 	    && (msg->msg.netfn == IPMI_NETFN_APP_RESPONSE)
5234 	    && (msg->msg.cmd == IPMI_GET_DEVICE_ID_CMD)
5235 	    && (msg->msg.data[0] == IPMI_CC_NO_ERROR)) {
5236 		/*
5237 		 * A get device id command, save if we are an event
5238 		 * receiver or generator.
5239 		 */
5240 		intf->local_sel_device = (msg->msg.data[6] >> 2) & 1;
5241 		intf->local_event_generator = (msg->msg.data[6] >> 5) & 1;
5242 	}
5243 }
5244 
5245 static void send_panic_events(struct ipmi_smi *intf, char *str)
5246 {
5247 	struct kernel_ipmi_msg msg;
5248 	unsigned char data[16];
5249 	struct ipmi_system_interface_addr *si;
5250 	struct ipmi_addr addr;
5251 	char *p = str;
5252 	struct ipmi_ipmb_addr *ipmb;
5253 	int j;
5254 
5255 	if (ipmi_send_panic_event == IPMI_SEND_PANIC_EVENT_NONE)
5256 		return;
5257 
5258 	si = (struct ipmi_system_interface_addr *) &addr;
5259 	si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
5260 	si->channel = IPMI_BMC_CHANNEL;
5261 	si->lun = 0;
5262 
5263 	/* Fill in an event telling that we have failed. */
5264 	msg.netfn = 0x04; /* Sensor or Event. */
5265 	msg.cmd = 2; /* Platform event command. */
5266 	msg.data = data;
5267 	msg.data_len = 8;
5268 	data[0] = 0x41; /* Kernel generator ID, IPMI table 5-4 */
5269 	data[1] = 0x03; /* This is for IPMI 1.0. */
5270 	data[2] = 0x20; /* OS Critical Stop, IPMI table 36-3 */
5271 	data[4] = 0x6f; /* Sensor specific, IPMI table 36-1 */
5272 	data[5] = 0xa1; /* Runtime stop OEM bytes 2 & 3. */
5273 
5274 	/*
5275 	 * Put a few breadcrumbs in.  Hopefully later we can add more things
5276 	 * to make the panic events more useful.
5277 	 */
5278 	if (str) {
5279 		data[3] = str[0];
5280 		data[6] = str[1];
5281 		data[7] = str[2];
5282 	}
5283 
5284 	/* Send the event announcing the panic. */
5285 	ipmi_panic_request_and_wait(intf, &addr, &msg);
5286 
5287 	/*
5288 	 * On every interface, dump a bunch of OEM event holding the
5289 	 * string.
5290 	 */
5291 	if (ipmi_send_panic_event != IPMI_SEND_PANIC_EVENT_STRING || !str)
5292 		return;
5293 
5294 	/*
5295 	 * intf_num is used as an marker to tell if the
5296 	 * interface is valid.  Thus we need a read barrier to
5297 	 * make sure data fetched before checking intf_num
5298 	 * won't be used.
5299 	 */
5300 	smp_rmb();
5301 
5302 	/*
5303 	 * First job here is to figure out where to send the
5304 	 * OEM events.  There's no way in IPMI to send OEM
5305 	 * events using an event send command, so we have to
5306 	 * find the SEL to put them in and stick them in
5307 	 * there.
5308 	 */
5309 
5310 	/* Get capabilities from the get device id. */
5311 	intf->local_sel_device = 0;
5312 	intf->local_event_generator = 0;
5313 	intf->event_receiver = 0;
5314 
5315 	/* Request the device info from the local MC. */
5316 	msg.netfn = IPMI_NETFN_APP_REQUEST;
5317 	msg.cmd = IPMI_GET_DEVICE_ID_CMD;
5318 	msg.data = NULL;
5319 	msg.data_len = 0;
5320 	intf->null_user_handler = device_id_fetcher;
5321 	ipmi_panic_request_and_wait(intf, &addr, &msg);
5322 
5323 	if (intf->local_event_generator) {
5324 		/* Request the event receiver from the local MC. */
5325 		msg.netfn = IPMI_NETFN_SENSOR_EVENT_REQUEST;
5326 		msg.cmd = IPMI_GET_EVENT_RECEIVER_CMD;
5327 		msg.data = NULL;
5328 		msg.data_len = 0;
5329 		intf->null_user_handler = event_receiver_fetcher;
5330 		ipmi_panic_request_and_wait(intf, &addr, &msg);
5331 	}
5332 	intf->null_user_handler = NULL;
5333 
5334 	/*
5335 	 * Validate the event receiver.  The low bit must not
5336 	 * be 1 (it must be a valid IPMB address), it cannot
5337 	 * be zero, and it must not be my address.
5338 	 */
5339 	if (((intf->event_receiver & 1) == 0)
5340 	    && (intf->event_receiver != 0)
5341 	    && (intf->event_receiver != intf->addrinfo[0].address)) {
5342 		/*
5343 		 * The event receiver is valid, send an IPMB
5344 		 * message.
5345 		 */
5346 		ipmb = (struct ipmi_ipmb_addr *) &addr;
5347 		ipmb->addr_type = IPMI_IPMB_ADDR_TYPE;
5348 		ipmb->channel = 0; /* FIXME - is this right? */
5349 		ipmb->lun = intf->event_receiver_lun;
5350 		ipmb->slave_addr = intf->event_receiver;
5351 	} else if (intf->local_sel_device) {
5352 		/*
5353 		 * The event receiver was not valid (or was
5354 		 * me), but I am an SEL device, just dump it
5355 		 * in my SEL.
5356 		 */
5357 		si = (struct ipmi_system_interface_addr *) &addr;
5358 		si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
5359 		si->channel = IPMI_BMC_CHANNEL;
5360 		si->lun = 0;
5361 	} else
5362 		return; /* No where to send the event. */
5363 
5364 	msg.netfn = IPMI_NETFN_STORAGE_REQUEST; /* Storage. */
5365 	msg.cmd = IPMI_ADD_SEL_ENTRY_CMD;
5366 	msg.data = data;
5367 	msg.data_len = 16;
5368 
5369 	j = 0;
5370 	while (*p) {
5371 		int size = strnlen(p, 11);
5372 
5373 		data[0] = 0;
5374 		data[1] = 0;
5375 		data[2] = 0xf0; /* OEM event without timestamp. */
5376 		data[3] = intf->addrinfo[0].address;
5377 		data[4] = j++; /* sequence # */
5378 
5379 		memcpy_and_pad(data+5, 11, p, size, '\0');
5380 		p += size;
5381 
5382 		ipmi_panic_request_and_wait(intf, &addr, &msg);
5383 	}
5384 }
5385 
5386 static int has_panicked;
5387 
5388 static int panic_event(struct notifier_block *this,
5389 		       unsigned long         event,
5390 		       void                  *ptr)
5391 {
5392 	struct ipmi_smi *intf;
5393 	struct ipmi_user *user;
5394 
5395 	if (has_panicked)
5396 		return NOTIFY_DONE;
5397 	has_panicked = 1;
5398 
5399 	/* For every registered interface, set it to run to completion. */
5400 	list_for_each_entry(intf, &ipmi_interfaces, link) {
5401 		if (!intf->handlers || intf->intf_num == -1)
5402 			/* Interface is not ready. */
5403 			continue;
5404 
5405 		if (!intf->handlers->poll)
5406 			continue;
5407 
5408 		/*
5409 		 * If we were interrupted while locking xmit_msgs_lock or
5410 		 * waiting_rcv_msgs_lock, the corresponding list may be
5411 		 * corrupted.  In this case, drop items on the list for
5412 		 * the safety.
5413 		 */
5414 		if (!spin_trylock(&intf->xmit_msgs_lock)) {
5415 			INIT_LIST_HEAD(&intf->xmit_msgs);
5416 			INIT_LIST_HEAD(&intf->hp_xmit_msgs);
5417 		} else
5418 			spin_unlock(&intf->xmit_msgs_lock);
5419 
5420 		if (!spin_trylock(&intf->waiting_rcv_msgs_lock))
5421 			INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
5422 		else
5423 			spin_unlock(&intf->waiting_rcv_msgs_lock);
5424 
5425 		intf->run_to_completion = 1;
5426 		if (intf->handlers->set_run_to_completion)
5427 			intf->handlers->set_run_to_completion(intf->send_info,
5428 							      1);
5429 
5430 		list_for_each_entry(user, &intf->users, link) {
5431 			if (user->handler->ipmi_panic_handler)
5432 				user->handler->ipmi_panic_handler(
5433 					user->handler_data);
5434 		}
5435 
5436 		send_panic_events(intf, ptr);
5437 	}
5438 
5439 	return NOTIFY_DONE;
5440 }
5441 
5442 /* Must be called with ipmi_interfaces_mutex held. */
5443 static int ipmi_register_driver(void)
5444 {
5445 	int rv;
5446 
5447 	if (drvregistered)
5448 		return 0;
5449 
5450 	rv = driver_register(&ipmidriver.driver);
5451 	if (rv)
5452 		pr_err("Could not register IPMI driver\n");
5453 	else
5454 		drvregistered = true;
5455 	return rv;
5456 }
5457 
5458 static struct notifier_block panic_block = {
5459 	.notifier_call	= panic_event,
5460 	.next		= NULL,
5461 	.priority	= 200	/* priority: INT_MAX >= x >= 0 */
5462 };
5463 
5464 static int ipmi_init_msghandler(void)
5465 {
5466 	int rv;
5467 
5468 	mutex_lock(&ipmi_interfaces_mutex);
5469 	rv = ipmi_register_driver();
5470 	if (rv)
5471 		goto out;
5472 	if (initialized)
5473 		goto out;
5474 
5475 	bmc_remove_work_wq = create_singlethread_workqueue("ipmi-msghandler-remove-wq");
5476 	if (!bmc_remove_work_wq) {
5477 		pr_err("unable to create ipmi-msghandler-remove-wq workqueue");
5478 		rv = -ENOMEM;
5479 		goto out;
5480 	}
5481 
5482 	timer_setup(&ipmi_timer, ipmi_timeout, 0);
5483 	mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
5484 
5485 	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
5486 
5487 	initialized = true;
5488 
5489 out:
5490 	mutex_unlock(&ipmi_interfaces_mutex);
5491 	return rv;
5492 }
5493 
5494 static int __init ipmi_init_msghandler_mod(void)
5495 {
5496 	int rv;
5497 
5498 	pr_info("version " IPMI_DRIVER_VERSION "\n");
5499 
5500 	mutex_lock(&ipmi_interfaces_mutex);
5501 	rv = ipmi_register_driver();
5502 	mutex_unlock(&ipmi_interfaces_mutex);
5503 
5504 	return rv;
5505 }
5506 
5507 static void __exit cleanup_ipmi(void)
5508 {
5509 	int count;
5510 
5511 	if (initialized) {
5512 		destroy_workqueue(bmc_remove_work_wq);
5513 
5514 		atomic_notifier_chain_unregister(&panic_notifier_list,
5515 						 &panic_block);
5516 
5517 		/*
5518 		 * This can't be called if any interfaces exist, so no worry
5519 		 * about shutting down the interfaces.
5520 		 */
5521 
5522 		/*
5523 		 * Tell the timer to stop, then wait for it to stop.  This
5524 		 * avoids problems with race conditions removing the timer
5525 		 * here.
5526 		 */
5527 		atomic_set(&stop_operation, 1);
5528 		timer_delete_sync(&ipmi_timer);
5529 		cancel_work_sync(&ipmi_timer_work);
5530 
5531 		initialized = false;
5532 
5533 		/* Check for buffer leaks. */
5534 		count = atomic_read(&smi_msg_inuse_count);
5535 		if (count != 0)
5536 			pr_warn("SMI message count %d at exit\n", count);
5537 		count = atomic_read(&recv_msg_inuse_count);
5538 		if (count != 0)
5539 			pr_warn("recv message count %d at exit\n", count);
5540 	}
5541 	if (drvregistered)
5542 		driver_unregister(&ipmidriver.driver);
5543 }
5544 module_exit(cleanup_ipmi);
5545 
5546 module_init(ipmi_init_msghandler_mod);
5547 MODULE_LICENSE("GPL");
5548 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
5549 MODULE_DESCRIPTION("Incoming and outgoing message routing for an IPMI interface.");
5550 MODULE_VERSION(IPMI_DRIVER_VERSION);
5551 MODULE_SOFTDEP("post: ipmi_devintf");
5552