1 /*
2  * ipmi_msghandler.c
3  *
4  * Incoming and outgoing message routing for an IPMI interface.
5  *
6  * Author: MontaVista Software, Inc.
7  *         Corey Minyard <minyard@mvista.com>
8  *         source@mvista.com
9  *
10  * Copyright 2002 MontaVista Software Inc.
11  *
12  *  This program is free software; you can redistribute it and/or modify it
13  *  under the terms of the GNU General Public License as published by the
14  *  Free Software Foundation; either version 2 of the License, or (at your
15  *  option) any later version.
16  *
17  *
18  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
19  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
20  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
23  *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
24  *  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
25  *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
26  *  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
27  *  USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  *  You should have received a copy of the GNU General Public License along
30  *  with this program; if not, write to the Free Software Foundation, Inc.,
31  *  675 Mass Ave, Cambridge, MA 02139, USA.
32  */
33 
34 #include <linux/module.h>
35 #include <linux/errno.h>
36 #include <linux/poll.h>
37 #include <linux/sched.h>
38 #include <linux/seq_file.h>
39 #include <linux/spinlock.h>
40 #include <linux/mutex.h>
41 #include <linux/slab.h>
42 #include <linux/ipmi.h>
43 #include <linux/ipmi_smi.h>
44 #include <linux/notifier.h>
45 #include <linux/init.h>
46 #include <linux/proc_fs.h>
47 #include <linux/rcupdate.h>
48 #include <linux/interrupt.h>
49 #include <linux/moduleparam.h>
50 #include <linux/workqueue.h>
51 #include <linux/uuid.h>
52 
53 #define PFX "IPMI message handler: "
54 
55 #define IPMI_DRIVER_VERSION "39.2"
56 
57 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void);
58 static int ipmi_init_msghandler(void);
59 static void smi_recv_tasklet(unsigned long);
60 static void handle_new_recv_msgs(ipmi_smi_t intf);
61 static void need_waiter(ipmi_smi_t intf);
62 static int handle_one_recv_msg(ipmi_smi_t          intf,
63 			       struct ipmi_smi_msg *msg);
64 
65 static int initialized;
66 
67 enum ipmi_panic_event_op {
68 	IPMI_SEND_PANIC_EVENT_NONE,
69 	IPMI_SEND_PANIC_EVENT,
70 	IPMI_SEND_PANIC_EVENT_STRING
71 };
72 #ifdef CONFIG_IPMI_PANIC_STRING
73 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT_STRING
74 #elif defined(CONFIG_IPMI_PANIC_EVENT)
75 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT
76 #else
77 #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT_NONE
78 #endif
79 static enum ipmi_panic_event_op ipmi_send_panic_event = IPMI_PANIC_DEFAULT;
80 
81 static int panic_op_write_handler(const char *val,
82 				  const struct kernel_param *kp)
83 {
84 	char valcp[16];
85 	char *s;
86 
87 	strncpy(valcp, val, 15);
88 	valcp[15] = '\0';
89 
90 	s = strstrip(valcp);
91 
92 	if (strcmp(s, "none") == 0)
93 		ipmi_send_panic_event = IPMI_SEND_PANIC_EVENT_NONE;
94 	else if (strcmp(s, "event") == 0)
95 		ipmi_send_panic_event = IPMI_SEND_PANIC_EVENT;
96 	else if (strcmp(s, "string") == 0)
97 		ipmi_send_panic_event = IPMI_SEND_PANIC_EVENT_STRING;
98 	else
99 		return -EINVAL;
100 
101 	return 0;
102 }
103 
104 static int panic_op_read_handler(char *buffer, const struct kernel_param *kp)
105 {
106 	switch (ipmi_send_panic_event) {
107 	case IPMI_SEND_PANIC_EVENT_NONE:
108 		strcpy(buffer, "none");
109 		break;
110 
111 	case IPMI_SEND_PANIC_EVENT:
112 		strcpy(buffer, "event");
113 		break;
114 
115 	case IPMI_SEND_PANIC_EVENT_STRING:
116 		strcpy(buffer, "string");
117 		break;
118 
119 	default:
120 		strcpy(buffer, "???");
121 		break;
122 	}
123 
124 	return strlen(buffer);
125 }
126 
127 static const struct kernel_param_ops panic_op_ops = {
128 	.set = panic_op_write_handler,
129 	.get = panic_op_read_handler
130 };
131 module_param_cb(panic_op, &panic_op_ops, NULL, 0600);
132 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.");
133 
134 
135 #ifdef CONFIG_IPMI_PROC_INTERFACE
136 static struct proc_dir_entry *proc_ipmi_root;
137 #endif /* CONFIG_IPMI_PROC_INTERFACE */
138 
139 /* Remain in auto-maintenance mode for this amount of time (in ms). */
140 #define IPMI_MAINTENANCE_MODE_TIMEOUT 30000
141 
142 #define MAX_EVENTS_IN_QUEUE	25
143 
144 /*
145  * Don't let a message sit in a queue forever, always time it with at lest
146  * the max message timer.  This is in milliseconds.
147  */
148 #define MAX_MSG_TIMEOUT		60000
149 
150 /* Call every ~1000 ms. */
151 #define IPMI_TIMEOUT_TIME	1000
152 
153 /* How many jiffies does it take to get to the timeout time. */
154 #define IPMI_TIMEOUT_JIFFIES	((IPMI_TIMEOUT_TIME * HZ) / 1000)
155 
156 /*
157  * Request events from the queue every second (this is the number of
158  * IPMI_TIMEOUT_TIMES between event requests).  Hopefully, in the
159  * future, IPMI will add a way to know immediately if an event is in
160  * the queue and this silliness can go away.
161  */
162 #define IPMI_REQUEST_EV_TIME	(1000 / (IPMI_TIMEOUT_TIME))
163 
164 /* How long should we cache dynamic device IDs? */
165 #define IPMI_DYN_DEV_ID_EXPIRY	(10 * HZ)
166 
167 /*
168  * The main "user" data structure.
169  */
170 struct ipmi_user {
171 	struct list_head link;
172 
173 	/* Set to false when the user is destroyed. */
174 	bool valid;
175 
176 	struct kref refcount;
177 
178 	/* The upper layer that handles receive messages. */
179 	const struct ipmi_user_hndl *handler;
180 	void             *handler_data;
181 
182 	/* The interface this user is bound to. */
183 	ipmi_smi_t intf;
184 
185 	/* Does this interface receive IPMI events? */
186 	bool gets_events;
187 };
188 
189 struct cmd_rcvr {
190 	struct list_head link;
191 
192 	ipmi_user_t   user;
193 	unsigned char netfn;
194 	unsigned char cmd;
195 	unsigned int  chans;
196 
197 	/*
198 	 * This is used to form a linked lised during mass deletion.
199 	 * Since this is in an RCU list, we cannot use the link above
200 	 * or change any data until the RCU period completes.  So we
201 	 * use this next variable during mass deletion so we can have
202 	 * a list and don't have to wait and restart the search on
203 	 * every individual deletion of a command.
204 	 */
205 	struct cmd_rcvr *next;
206 };
207 
208 struct seq_table {
209 	unsigned int         inuse : 1;
210 	unsigned int         broadcast : 1;
211 
212 	unsigned long        timeout;
213 	unsigned long        orig_timeout;
214 	unsigned int         retries_left;
215 
216 	/*
217 	 * To verify on an incoming send message response that this is
218 	 * the message that the response is for, we keep a sequence id
219 	 * and increment it every time we send a message.
220 	 */
221 	long                 seqid;
222 
223 	/*
224 	 * This is held so we can properly respond to the message on a
225 	 * timeout, and it is used to hold the temporary data for
226 	 * retransmission, too.
227 	 */
228 	struct ipmi_recv_msg *recv_msg;
229 };
230 
231 /*
232  * Store the information in a msgid (long) to allow us to find a
233  * sequence table entry from the msgid.
234  */
235 #define STORE_SEQ_IN_MSGID(seq, seqid) \
236 	((((seq) & 0x3f) << 26) | ((seqid) & 0x3ffffff))
237 
238 #define GET_SEQ_FROM_MSGID(msgid, seq, seqid) \
239 	do {								\
240 		seq = (((msgid) >> 26) & 0x3f);				\
241 		seqid = ((msgid) & 0x3ffffff);				\
242 	} while (0)
243 
244 #define NEXT_SEQID(seqid) (((seqid) + 1) & 0x3ffffff)
245 
246 #define IPMI_MAX_CHANNELS       16
247 struct ipmi_channel {
248 	unsigned char medium;
249 	unsigned char protocol;
250 };
251 
252 struct ipmi_channel_set {
253 	struct ipmi_channel c[IPMI_MAX_CHANNELS];
254 };
255 
256 struct ipmi_my_addrinfo {
257 	/*
258 	 * My slave address.  This is initialized to IPMI_BMC_SLAVE_ADDR,
259 	 * but may be changed by the user.
260 	 */
261 	unsigned char address;
262 
263 	/*
264 	 * My LUN.  This should generally stay the SMS LUN, but just in
265 	 * case...
266 	 */
267 	unsigned char lun;
268 };
269 
270 #ifdef CONFIG_IPMI_PROC_INTERFACE
271 struct ipmi_proc_entry {
272 	char                   *name;
273 	struct ipmi_proc_entry *next;
274 };
275 #endif
276 
277 /*
278  * Note that the product id, manufacturer id, guid, and device id are
279  * immutable in this structure, so dyn_mutex is not required for
280  * accessing those.  If those change on a BMC, a new BMC is allocated.
281  */
282 struct bmc_device {
283 	struct platform_device pdev;
284 	struct list_head       intfs; /* Interfaces on this BMC. */
285 	struct ipmi_device_id  id;
286 	struct ipmi_device_id  fetch_id;
287 	int                    dyn_id_set;
288 	unsigned long          dyn_id_expiry;
289 	struct mutex           dyn_mutex; /* Protects id, intfs, & dyn* */
290 	guid_t                 guid;
291 	guid_t                 fetch_guid;
292 	int                    dyn_guid_set;
293 	struct kref	       usecount;
294 	struct work_struct     remove_work;
295 };
296 #define to_bmc_device(x) container_of((x), struct bmc_device, pdev.dev)
297 
298 static int bmc_get_device_id(ipmi_smi_t intf, struct bmc_device *bmc,
299 			     struct ipmi_device_id *id,
300 			     bool *guid_set, guid_t *guid);
301 
302 /*
303  * Various statistics for IPMI, these index stats[] in the ipmi_smi
304  * structure.
305  */
306 enum ipmi_stat_indexes {
307 	/* Commands we got from the user that were invalid. */
308 	IPMI_STAT_sent_invalid_commands = 0,
309 
310 	/* Commands we sent to the MC. */
311 	IPMI_STAT_sent_local_commands,
312 
313 	/* Responses from the MC that were delivered to a user. */
314 	IPMI_STAT_handled_local_responses,
315 
316 	/* Responses from the MC that were not delivered to a user. */
317 	IPMI_STAT_unhandled_local_responses,
318 
319 	/* Commands we sent out to the IPMB bus. */
320 	IPMI_STAT_sent_ipmb_commands,
321 
322 	/* Commands sent on the IPMB that had errors on the SEND CMD */
323 	IPMI_STAT_sent_ipmb_command_errs,
324 
325 	/* Each retransmit increments this count. */
326 	IPMI_STAT_retransmitted_ipmb_commands,
327 
328 	/*
329 	 * When a message times out (runs out of retransmits) this is
330 	 * incremented.
331 	 */
332 	IPMI_STAT_timed_out_ipmb_commands,
333 
334 	/*
335 	 * This is like above, but for broadcasts.  Broadcasts are
336 	 * *not* included in the above count (they are expected to
337 	 * time out).
338 	 */
339 	IPMI_STAT_timed_out_ipmb_broadcasts,
340 
341 	/* Responses I have sent to the IPMB bus. */
342 	IPMI_STAT_sent_ipmb_responses,
343 
344 	/* The response was delivered to the user. */
345 	IPMI_STAT_handled_ipmb_responses,
346 
347 	/* The response had invalid data in it. */
348 	IPMI_STAT_invalid_ipmb_responses,
349 
350 	/* The response didn't have anyone waiting for it. */
351 	IPMI_STAT_unhandled_ipmb_responses,
352 
353 	/* Commands we sent out to the IPMB bus. */
354 	IPMI_STAT_sent_lan_commands,
355 
356 	/* Commands sent on the IPMB that had errors on the SEND CMD */
357 	IPMI_STAT_sent_lan_command_errs,
358 
359 	/* Each retransmit increments this count. */
360 	IPMI_STAT_retransmitted_lan_commands,
361 
362 	/*
363 	 * When a message times out (runs out of retransmits) this is
364 	 * incremented.
365 	 */
366 	IPMI_STAT_timed_out_lan_commands,
367 
368 	/* Responses I have sent to the IPMB bus. */
369 	IPMI_STAT_sent_lan_responses,
370 
371 	/* The response was delivered to the user. */
372 	IPMI_STAT_handled_lan_responses,
373 
374 	/* The response had invalid data in it. */
375 	IPMI_STAT_invalid_lan_responses,
376 
377 	/* The response didn't have anyone waiting for it. */
378 	IPMI_STAT_unhandled_lan_responses,
379 
380 	/* The command was delivered to the user. */
381 	IPMI_STAT_handled_commands,
382 
383 	/* The command had invalid data in it. */
384 	IPMI_STAT_invalid_commands,
385 
386 	/* The command didn't have anyone waiting for it. */
387 	IPMI_STAT_unhandled_commands,
388 
389 	/* Invalid data in an event. */
390 	IPMI_STAT_invalid_events,
391 
392 	/* Events that were received with the proper format. */
393 	IPMI_STAT_events,
394 
395 	/* Retransmissions on IPMB that failed. */
396 	IPMI_STAT_dropped_rexmit_ipmb_commands,
397 
398 	/* Retransmissions on LAN that failed. */
399 	IPMI_STAT_dropped_rexmit_lan_commands,
400 
401 	/* This *must* remain last, add new values above this. */
402 	IPMI_NUM_STATS
403 };
404 
405 
406 #define IPMI_IPMB_NUM_SEQ	64
407 struct ipmi_smi {
408 	/* What interface number are we? */
409 	int intf_num;
410 
411 	struct kref refcount;
412 
413 	/* Set when the interface is being unregistered. */
414 	bool in_shutdown;
415 
416 	/* Used for a list of interfaces. */
417 	struct list_head link;
418 
419 	/*
420 	 * The list of upper layers that are using me.  seq_lock
421 	 * protects this.
422 	 */
423 	struct list_head users;
424 
425 	/* Used for wake ups at startup. */
426 	wait_queue_head_t waitq;
427 
428 	/*
429 	 * Prevents the interface from being unregistered when the
430 	 * interface is used by being looked up through the BMC
431 	 * structure.
432 	 */
433 	struct mutex bmc_reg_mutex;
434 
435 	struct bmc_device tmp_bmc;
436 	struct bmc_device *bmc;
437 	bool bmc_registered;
438 	struct list_head bmc_link;
439 	char *my_dev_name;
440 	bool in_bmc_register;  /* Handle recursive situations.  Yuck. */
441 	struct work_struct bmc_reg_work;
442 
443 	/*
444 	 * This is the lower-layer's sender routine.  Note that you
445 	 * must either be holding the ipmi_interfaces_mutex or be in
446 	 * an umpreemptible region to use this.  You must fetch the
447 	 * value into a local variable and make sure it is not NULL.
448 	 */
449 	const struct ipmi_smi_handlers *handlers;
450 	void                     *send_info;
451 
452 #ifdef CONFIG_IPMI_PROC_INTERFACE
453 	/* A list of proc entries for this interface. */
454 	struct mutex           proc_entry_lock;
455 	struct ipmi_proc_entry *proc_entries;
456 
457 	struct proc_dir_entry *proc_dir;
458 	char                  proc_dir_name[10];
459 #endif
460 
461 	/* Driver-model device for the system interface. */
462 	struct device          *si_dev;
463 
464 	/*
465 	 * A table of sequence numbers for this interface.  We use the
466 	 * sequence numbers for IPMB messages that go out of the
467 	 * interface to match them up with their responses.  A routine
468 	 * is called periodically to time the items in this list.
469 	 */
470 	spinlock_t       seq_lock;
471 	struct seq_table seq_table[IPMI_IPMB_NUM_SEQ];
472 	int curr_seq;
473 
474 	/*
475 	 * Messages queued for delivery.  If delivery fails (out of memory
476 	 * for instance), They will stay in here to be processed later in a
477 	 * periodic timer interrupt.  The tasklet is for handling received
478 	 * messages directly from the handler.
479 	 */
480 	spinlock_t       waiting_rcv_msgs_lock;
481 	struct list_head waiting_rcv_msgs;
482 	atomic_t	 watchdog_pretimeouts_to_deliver;
483 	struct tasklet_struct recv_tasklet;
484 
485 	spinlock_t             xmit_msgs_lock;
486 	struct list_head       xmit_msgs;
487 	struct ipmi_smi_msg    *curr_msg;
488 	struct list_head       hp_xmit_msgs;
489 
490 	/*
491 	 * The list of command receivers that are registered for commands
492 	 * on this interface.
493 	 */
494 	struct mutex     cmd_rcvrs_mutex;
495 	struct list_head cmd_rcvrs;
496 
497 	/*
498 	 * Events that were queues because no one was there to receive
499 	 * them.
500 	 */
501 	spinlock_t       events_lock; /* For dealing with event stuff. */
502 	struct list_head waiting_events;
503 	unsigned int     waiting_events_count; /* How many events in queue? */
504 	char             delivering_events;
505 	char             event_msg_printed;
506 	atomic_t         event_waiters;
507 	unsigned int     ticks_to_req_ev;
508 	int              last_needs_timer;
509 
510 	/*
511 	 * The event receiver for my BMC, only really used at panic
512 	 * shutdown as a place to store this.
513 	 */
514 	unsigned char event_receiver;
515 	unsigned char event_receiver_lun;
516 	unsigned char local_sel_device;
517 	unsigned char local_event_generator;
518 
519 	/* For handling of maintenance mode. */
520 	int maintenance_mode;
521 	bool maintenance_mode_enable;
522 	int auto_maintenance_timeout;
523 	spinlock_t maintenance_mode_lock; /* Used in a timer... */
524 
525 	/*
526 	 * A cheap hack, if this is non-null and a message to an
527 	 * interface comes in with a NULL user, call this routine with
528 	 * it.  Note that the message will still be freed by the
529 	 * caller.  This only works on the system interface.
530 	 *
531 	 * Protected by bmc_reg_mutex.
532 	 */
533 	void (*null_user_handler)(ipmi_smi_t intf, struct ipmi_recv_msg *msg);
534 
535 	/*
536 	 * When we are scanning the channels for an SMI, this will
537 	 * tell which channel we are scanning.
538 	 */
539 	int curr_channel;
540 
541 	/* Channel information */
542 	struct ipmi_channel_set *channel_list;
543 	unsigned int curr_working_cset; /* First index into the following. */
544 	struct ipmi_channel_set wchannels[2];
545 	struct ipmi_my_addrinfo addrinfo[IPMI_MAX_CHANNELS];
546 	bool channels_ready;
547 
548 	atomic_t stats[IPMI_NUM_STATS];
549 
550 	/*
551 	 * run_to_completion duplicate of smb_info, smi_info
552 	 * and ipmi_serial_info structures. Used to decrease numbers of
553 	 * parameters passed by "low" level IPMI code.
554 	 */
555 	int run_to_completion;
556 };
557 #define to_si_intf_from_dev(device) container_of(device, struct ipmi_smi, dev)
558 
559 static void __get_guid(ipmi_smi_t intf);
560 static void __ipmi_bmc_unregister(ipmi_smi_t intf);
561 static int __ipmi_bmc_register(ipmi_smi_t intf,
562 			       struct ipmi_device_id *id,
563 			       bool guid_set, guid_t *guid, int intf_num);
564 static int __scan_channels(ipmi_smi_t intf, struct ipmi_device_id *id);
565 
566 
567 /**
568  * The driver model view of the IPMI messaging driver.
569  */
570 static struct platform_driver ipmidriver = {
571 	.driver = {
572 		.name = "ipmi",
573 		.bus = &platform_bus_type
574 	}
575 };
576 /*
577  * This mutex keeps us from adding the same BMC twice.
578  */
579 static DEFINE_MUTEX(ipmidriver_mutex);
580 
581 static LIST_HEAD(ipmi_interfaces);
582 static DEFINE_MUTEX(ipmi_interfaces_mutex);
583 
584 /*
585  * List of watchers that want to know when smi's are added and deleted.
586  */
587 static LIST_HEAD(smi_watchers);
588 static DEFINE_MUTEX(smi_watchers_mutex);
589 
590 #define ipmi_inc_stat(intf, stat) \
591 	atomic_inc(&(intf)->stats[IPMI_STAT_ ## stat])
592 #define ipmi_get_stat(intf, stat) \
593 	((unsigned int) atomic_read(&(intf)->stats[IPMI_STAT_ ## stat]))
594 
595 static const char * const addr_src_to_str[] = {
596 	"invalid", "hotmod", "hardcoded", "SPMI", "ACPI", "SMBIOS", "PCI",
597 	"device-tree", "platform"
598 };
599 
600 const char *ipmi_addr_src_to_str(enum ipmi_addr_src src)
601 {
602 	if (src >= SI_LAST)
603 		src = 0; /* Invalid */
604 	return addr_src_to_str[src];
605 }
606 EXPORT_SYMBOL(ipmi_addr_src_to_str);
607 
608 static int is_lan_addr(struct ipmi_addr *addr)
609 {
610 	return addr->addr_type == IPMI_LAN_ADDR_TYPE;
611 }
612 
613 static int is_ipmb_addr(struct ipmi_addr *addr)
614 {
615 	return addr->addr_type == IPMI_IPMB_ADDR_TYPE;
616 }
617 
618 static int is_ipmb_bcast_addr(struct ipmi_addr *addr)
619 {
620 	return addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE;
621 }
622 
623 static void free_recv_msg_list(struct list_head *q)
624 {
625 	struct ipmi_recv_msg *msg, *msg2;
626 
627 	list_for_each_entry_safe(msg, msg2, q, link) {
628 		list_del(&msg->link);
629 		ipmi_free_recv_msg(msg);
630 	}
631 }
632 
633 static void free_smi_msg_list(struct list_head *q)
634 {
635 	struct ipmi_smi_msg *msg, *msg2;
636 
637 	list_for_each_entry_safe(msg, msg2, q, link) {
638 		list_del(&msg->link);
639 		ipmi_free_smi_msg(msg);
640 	}
641 }
642 
643 static void clean_up_interface_data(ipmi_smi_t intf)
644 {
645 	int              i;
646 	struct cmd_rcvr  *rcvr, *rcvr2;
647 	struct list_head list;
648 
649 	tasklet_kill(&intf->recv_tasklet);
650 
651 	free_smi_msg_list(&intf->waiting_rcv_msgs);
652 	free_recv_msg_list(&intf->waiting_events);
653 
654 	/*
655 	 * Wholesale remove all the entries from the list in the
656 	 * interface and wait for RCU to know that none are in use.
657 	 */
658 	mutex_lock(&intf->cmd_rcvrs_mutex);
659 	INIT_LIST_HEAD(&list);
660 	list_splice_init_rcu(&intf->cmd_rcvrs, &list, synchronize_rcu);
661 	mutex_unlock(&intf->cmd_rcvrs_mutex);
662 
663 	list_for_each_entry_safe(rcvr, rcvr2, &list, link)
664 		kfree(rcvr);
665 
666 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
667 		if ((intf->seq_table[i].inuse)
668 					&& (intf->seq_table[i].recv_msg))
669 			ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
670 	}
671 }
672 
673 static void intf_free(struct kref *ref)
674 {
675 	ipmi_smi_t intf = container_of(ref, struct ipmi_smi, refcount);
676 
677 	clean_up_interface_data(intf);
678 	kfree(intf);
679 }
680 
681 struct watcher_entry {
682 	int              intf_num;
683 	ipmi_smi_t       intf;
684 	struct list_head link;
685 };
686 
687 int ipmi_smi_watcher_register(struct ipmi_smi_watcher *watcher)
688 {
689 	ipmi_smi_t intf;
690 	LIST_HEAD(to_deliver);
691 	struct watcher_entry *e, *e2;
692 
693 	mutex_lock(&smi_watchers_mutex);
694 
695 	mutex_lock(&ipmi_interfaces_mutex);
696 
697 	/* Build a list of things to deliver. */
698 	list_for_each_entry(intf, &ipmi_interfaces, link) {
699 		if (intf->intf_num == -1)
700 			continue;
701 		e = kmalloc(sizeof(*e), GFP_KERNEL);
702 		if (!e)
703 			goto out_err;
704 		kref_get(&intf->refcount);
705 		e->intf = intf;
706 		e->intf_num = intf->intf_num;
707 		list_add_tail(&e->link, &to_deliver);
708 	}
709 
710 	/* We will succeed, so add it to the list. */
711 	list_add(&watcher->link, &smi_watchers);
712 
713 	mutex_unlock(&ipmi_interfaces_mutex);
714 
715 	list_for_each_entry_safe(e, e2, &to_deliver, link) {
716 		list_del(&e->link);
717 		watcher->new_smi(e->intf_num, e->intf->si_dev);
718 		kref_put(&e->intf->refcount, intf_free);
719 		kfree(e);
720 	}
721 
722 	mutex_unlock(&smi_watchers_mutex);
723 
724 	return 0;
725 
726  out_err:
727 	mutex_unlock(&ipmi_interfaces_mutex);
728 	mutex_unlock(&smi_watchers_mutex);
729 	list_for_each_entry_safe(e, e2, &to_deliver, link) {
730 		list_del(&e->link);
731 		kref_put(&e->intf->refcount, intf_free);
732 		kfree(e);
733 	}
734 	return -ENOMEM;
735 }
736 EXPORT_SYMBOL(ipmi_smi_watcher_register);
737 
738 int ipmi_smi_watcher_unregister(struct ipmi_smi_watcher *watcher)
739 {
740 	mutex_lock(&smi_watchers_mutex);
741 	list_del(&(watcher->link));
742 	mutex_unlock(&smi_watchers_mutex);
743 	return 0;
744 }
745 EXPORT_SYMBOL(ipmi_smi_watcher_unregister);
746 
747 /*
748  * Must be called with smi_watchers_mutex held.
749  */
750 static void
751 call_smi_watchers(int i, struct device *dev)
752 {
753 	struct ipmi_smi_watcher *w;
754 
755 	list_for_each_entry(w, &smi_watchers, link) {
756 		if (try_module_get(w->owner)) {
757 			w->new_smi(i, dev);
758 			module_put(w->owner);
759 		}
760 	}
761 }
762 
763 static int
764 ipmi_addr_equal(struct ipmi_addr *addr1, struct ipmi_addr *addr2)
765 {
766 	if (addr1->addr_type != addr2->addr_type)
767 		return 0;
768 
769 	if (addr1->channel != addr2->channel)
770 		return 0;
771 
772 	if (addr1->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
773 		struct ipmi_system_interface_addr *smi_addr1
774 		    = (struct ipmi_system_interface_addr *) addr1;
775 		struct ipmi_system_interface_addr *smi_addr2
776 		    = (struct ipmi_system_interface_addr *) addr2;
777 		return (smi_addr1->lun == smi_addr2->lun);
778 	}
779 
780 	if (is_ipmb_addr(addr1) || is_ipmb_bcast_addr(addr1)) {
781 		struct ipmi_ipmb_addr *ipmb_addr1
782 		    = (struct ipmi_ipmb_addr *) addr1;
783 		struct ipmi_ipmb_addr *ipmb_addr2
784 		    = (struct ipmi_ipmb_addr *) addr2;
785 
786 		return ((ipmb_addr1->slave_addr == ipmb_addr2->slave_addr)
787 			&& (ipmb_addr1->lun == ipmb_addr2->lun));
788 	}
789 
790 	if (is_lan_addr(addr1)) {
791 		struct ipmi_lan_addr *lan_addr1
792 			= (struct ipmi_lan_addr *) addr1;
793 		struct ipmi_lan_addr *lan_addr2
794 		    = (struct ipmi_lan_addr *) addr2;
795 
796 		return ((lan_addr1->remote_SWID == lan_addr2->remote_SWID)
797 			&& (lan_addr1->local_SWID == lan_addr2->local_SWID)
798 			&& (lan_addr1->session_handle
799 			    == lan_addr2->session_handle)
800 			&& (lan_addr1->lun == lan_addr2->lun));
801 	}
802 
803 	return 1;
804 }
805 
806 int ipmi_validate_addr(struct ipmi_addr *addr, int len)
807 {
808 	if (len < sizeof(struct ipmi_system_interface_addr))
809 		return -EINVAL;
810 
811 	if (addr->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
812 		if (addr->channel != IPMI_BMC_CHANNEL)
813 			return -EINVAL;
814 		return 0;
815 	}
816 
817 	if ((addr->channel == IPMI_BMC_CHANNEL)
818 	    || (addr->channel >= IPMI_MAX_CHANNELS)
819 	    || (addr->channel < 0))
820 		return -EINVAL;
821 
822 	if (is_ipmb_addr(addr) || is_ipmb_bcast_addr(addr)) {
823 		if (len < sizeof(struct ipmi_ipmb_addr))
824 			return -EINVAL;
825 		return 0;
826 	}
827 
828 	if (is_lan_addr(addr)) {
829 		if (len < sizeof(struct ipmi_lan_addr))
830 			return -EINVAL;
831 		return 0;
832 	}
833 
834 	return -EINVAL;
835 }
836 EXPORT_SYMBOL(ipmi_validate_addr);
837 
838 unsigned int ipmi_addr_length(int addr_type)
839 {
840 	if (addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
841 		return sizeof(struct ipmi_system_interface_addr);
842 
843 	if ((addr_type == IPMI_IPMB_ADDR_TYPE)
844 			|| (addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE))
845 		return sizeof(struct ipmi_ipmb_addr);
846 
847 	if (addr_type == IPMI_LAN_ADDR_TYPE)
848 		return sizeof(struct ipmi_lan_addr);
849 
850 	return 0;
851 }
852 EXPORT_SYMBOL(ipmi_addr_length);
853 
854 static void deliver_response(struct ipmi_recv_msg *msg)
855 {
856 	if (!msg->user) {
857 		ipmi_smi_t    intf = msg->user_msg_data;
858 
859 		/* Special handling for NULL users. */
860 		if (intf->null_user_handler) {
861 			intf->null_user_handler(intf, msg);
862 			ipmi_inc_stat(intf, handled_local_responses);
863 		} else {
864 			/* No handler, so give up. */
865 			ipmi_inc_stat(intf, unhandled_local_responses);
866 		}
867 		ipmi_free_recv_msg(msg);
868 	} else if (!oops_in_progress) {
869 		/*
870 		 * If we are running in the panic context, calling the
871 		 * receive handler doesn't much meaning and has a deadlock
872 		 * risk.  At this moment, simply skip it in that case.
873 		 */
874 
875 		ipmi_user_t user = msg->user;
876 		user->handler->ipmi_recv_hndl(msg, user->handler_data);
877 	}
878 }
879 
880 static void
881 deliver_err_response(struct ipmi_recv_msg *msg, int err)
882 {
883 	msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
884 	msg->msg_data[0] = err;
885 	msg->msg.netfn |= 1; /* Convert to a response. */
886 	msg->msg.data_len = 1;
887 	msg->msg.data = msg->msg_data;
888 	deliver_response(msg);
889 }
890 
891 /*
892  * Find the next sequence number not being used and add the given
893  * message with the given timeout to the sequence table.  This must be
894  * called with the interface's seq_lock held.
895  */
896 static int intf_next_seq(ipmi_smi_t           intf,
897 			 struct ipmi_recv_msg *recv_msg,
898 			 unsigned long        timeout,
899 			 int                  retries,
900 			 int                  broadcast,
901 			 unsigned char        *seq,
902 			 long                 *seqid)
903 {
904 	int          rv = 0;
905 	unsigned int i;
906 
907 	for (i = intf->curr_seq; (i+1)%IPMI_IPMB_NUM_SEQ != intf->curr_seq;
908 					i = (i+1)%IPMI_IPMB_NUM_SEQ) {
909 		if (!intf->seq_table[i].inuse)
910 			break;
911 	}
912 
913 	if (!intf->seq_table[i].inuse) {
914 		intf->seq_table[i].recv_msg = recv_msg;
915 
916 		/*
917 		 * Start with the maximum timeout, when the send response
918 		 * comes in we will start the real timer.
919 		 */
920 		intf->seq_table[i].timeout = MAX_MSG_TIMEOUT;
921 		intf->seq_table[i].orig_timeout = timeout;
922 		intf->seq_table[i].retries_left = retries;
923 		intf->seq_table[i].broadcast = broadcast;
924 		intf->seq_table[i].inuse = 1;
925 		intf->seq_table[i].seqid = NEXT_SEQID(intf->seq_table[i].seqid);
926 		*seq = i;
927 		*seqid = intf->seq_table[i].seqid;
928 		intf->curr_seq = (i+1)%IPMI_IPMB_NUM_SEQ;
929 		need_waiter(intf);
930 	} else {
931 		rv = -EAGAIN;
932 	}
933 
934 	return rv;
935 }
936 
937 /*
938  * Return the receive message for the given sequence number and
939  * release the sequence number so it can be reused.  Some other data
940  * is passed in to be sure the message matches up correctly (to help
941  * guard against message coming in after their timeout and the
942  * sequence number being reused).
943  */
944 static int intf_find_seq(ipmi_smi_t           intf,
945 			 unsigned char        seq,
946 			 short                channel,
947 			 unsigned char        cmd,
948 			 unsigned char        netfn,
949 			 struct ipmi_addr     *addr,
950 			 struct ipmi_recv_msg **recv_msg)
951 {
952 	int           rv = -ENODEV;
953 	unsigned long flags;
954 
955 	if (seq >= IPMI_IPMB_NUM_SEQ)
956 		return -EINVAL;
957 
958 	spin_lock_irqsave(&(intf->seq_lock), flags);
959 	if (intf->seq_table[seq].inuse) {
960 		struct ipmi_recv_msg *msg = intf->seq_table[seq].recv_msg;
961 
962 		if ((msg->addr.channel == channel) && (msg->msg.cmd == cmd)
963 				&& (msg->msg.netfn == netfn)
964 				&& (ipmi_addr_equal(addr, &(msg->addr)))) {
965 			*recv_msg = msg;
966 			intf->seq_table[seq].inuse = 0;
967 			rv = 0;
968 		}
969 	}
970 	spin_unlock_irqrestore(&(intf->seq_lock), flags);
971 
972 	return rv;
973 }
974 
975 
976 /* Start the timer for a specific sequence table entry. */
977 static int intf_start_seq_timer(ipmi_smi_t intf,
978 				long       msgid)
979 {
980 	int           rv = -ENODEV;
981 	unsigned long flags;
982 	unsigned char seq;
983 	unsigned long seqid;
984 
985 
986 	GET_SEQ_FROM_MSGID(msgid, seq, seqid);
987 
988 	spin_lock_irqsave(&(intf->seq_lock), flags);
989 	/*
990 	 * We do this verification because the user can be deleted
991 	 * while a message is outstanding.
992 	 */
993 	if ((intf->seq_table[seq].inuse)
994 				&& (intf->seq_table[seq].seqid == seqid)) {
995 		struct seq_table *ent = &(intf->seq_table[seq]);
996 		ent->timeout = ent->orig_timeout;
997 		rv = 0;
998 	}
999 	spin_unlock_irqrestore(&(intf->seq_lock), flags);
1000 
1001 	return rv;
1002 }
1003 
1004 /* Got an error for the send message for a specific sequence number. */
1005 static int intf_err_seq(ipmi_smi_t   intf,
1006 			long         msgid,
1007 			unsigned int err)
1008 {
1009 	int                  rv = -ENODEV;
1010 	unsigned long        flags;
1011 	unsigned char        seq;
1012 	unsigned long        seqid;
1013 	struct ipmi_recv_msg *msg = NULL;
1014 
1015 
1016 	GET_SEQ_FROM_MSGID(msgid, seq, seqid);
1017 
1018 	spin_lock_irqsave(&(intf->seq_lock), flags);
1019 	/*
1020 	 * We do this verification because the user can be deleted
1021 	 * while a message is outstanding.
1022 	 */
1023 	if ((intf->seq_table[seq].inuse)
1024 				&& (intf->seq_table[seq].seqid == seqid)) {
1025 		struct seq_table *ent = &(intf->seq_table[seq]);
1026 
1027 		ent->inuse = 0;
1028 		msg = ent->recv_msg;
1029 		rv = 0;
1030 	}
1031 	spin_unlock_irqrestore(&(intf->seq_lock), flags);
1032 
1033 	if (msg)
1034 		deliver_err_response(msg, err);
1035 
1036 	return rv;
1037 }
1038 
1039 
1040 int ipmi_create_user(unsigned int          if_num,
1041 		     const struct ipmi_user_hndl *handler,
1042 		     void                  *handler_data,
1043 		     ipmi_user_t           *user)
1044 {
1045 	unsigned long flags;
1046 	ipmi_user_t   new_user;
1047 	int           rv = 0;
1048 	ipmi_smi_t    intf;
1049 
1050 	/*
1051 	 * There is no module usecount here, because it's not
1052 	 * required.  Since this can only be used by and called from
1053 	 * other modules, they will implicitly use this module, and
1054 	 * thus this can't be removed unless the other modules are
1055 	 * removed.
1056 	 */
1057 
1058 	if (handler == NULL)
1059 		return -EINVAL;
1060 
1061 	/*
1062 	 * Make sure the driver is actually initialized, this handles
1063 	 * problems with initialization order.
1064 	 */
1065 	if (!initialized) {
1066 		rv = ipmi_init_msghandler();
1067 		if (rv)
1068 			return rv;
1069 
1070 		/*
1071 		 * The init code doesn't return an error if it was turned
1072 		 * off, but it won't initialize.  Check that.
1073 		 */
1074 		if (!initialized)
1075 			return -ENODEV;
1076 	}
1077 
1078 	new_user = kmalloc(sizeof(*new_user), GFP_KERNEL);
1079 	if (!new_user)
1080 		return -ENOMEM;
1081 
1082 	mutex_lock(&ipmi_interfaces_mutex);
1083 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
1084 		if (intf->intf_num == if_num)
1085 			goto found;
1086 	}
1087 	/* Not found, return an error */
1088 	rv = -EINVAL;
1089 	goto out_kfree;
1090 
1091  found:
1092 	/* Note that each existing user holds a refcount to the interface. */
1093 	kref_get(&intf->refcount);
1094 
1095 	kref_init(&new_user->refcount);
1096 	new_user->handler = handler;
1097 	new_user->handler_data = handler_data;
1098 	new_user->intf = intf;
1099 	new_user->gets_events = false;
1100 
1101 	if (!try_module_get(intf->handlers->owner)) {
1102 		rv = -ENODEV;
1103 		goto out_kref;
1104 	}
1105 
1106 	if (intf->handlers->inc_usecount) {
1107 		rv = intf->handlers->inc_usecount(intf->send_info);
1108 		if (rv) {
1109 			module_put(intf->handlers->owner);
1110 			goto out_kref;
1111 		}
1112 	}
1113 
1114 	/*
1115 	 * Hold the lock so intf->handlers is guaranteed to be good
1116 	 * until now
1117 	 */
1118 	mutex_unlock(&ipmi_interfaces_mutex);
1119 
1120 	new_user->valid = true;
1121 	spin_lock_irqsave(&intf->seq_lock, flags);
1122 	list_add_rcu(&new_user->link, &intf->users);
1123 	spin_unlock_irqrestore(&intf->seq_lock, flags);
1124 	if (handler->ipmi_watchdog_pretimeout) {
1125 		/* User wants pretimeouts, so make sure to watch for them. */
1126 		if (atomic_inc_return(&intf->event_waiters) == 1)
1127 			need_waiter(intf);
1128 	}
1129 	*user = new_user;
1130 	return 0;
1131 
1132 out_kref:
1133 	kref_put(&intf->refcount, intf_free);
1134 out_kfree:
1135 	mutex_unlock(&ipmi_interfaces_mutex);
1136 	kfree(new_user);
1137 	return rv;
1138 }
1139 EXPORT_SYMBOL(ipmi_create_user);
1140 
1141 int ipmi_get_smi_info(int if_num, struct ipmi_smi_info *data)
1142 {
1143 	int           rv = 0;
1144 	ipmi_smi_t    intf;
1145 	const struct ipmi_smi_handlers *handlers;
1146 
1147 	mutex_lock(&ipmi_interfaces_mutex);
1148 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
1149 		if (intf->intf_num == if_num)
1150 			goto found;
1151 	}
1152 	/* Not found, return an error */
1153 	rv = -EINVAL;
1154 	mutex_unlock(&ipmi_interfaces_mutex);
1155 	return rv;
1156 
1157 found:
1158 	handlers = intf->handlers;
1159 	rv = -ENOSYS;
1160 	if (handlers->get_smi_info)
1161 		rv = handlers->get_smi_info(intf->send_info, data);
1162 	mutex_unlock(&ipmi_interfaces_mutex);
1163 
1164 	return rv;
1165 }
1166 EXPORT_SYMBOL(ipmi_get_smi_info);
1167 
1168 static void free_user(struct kref *ref)
1169 {
1170 	ipmi_user_t user = container_of(ref, struct ipmi_user, refcount);
1171 	kfree(user);
1172 }
1173 
1174 int ipmi_destroy_user(ipmi_user_t user)
1175 {
1176 	ipmi_smi_t       intf = user->intf;
1177 	int              i;
1178 	unsigned long    flags;
1179 	struct cmd_rcvr  *rcvr;
1180 	struct cmd_rcvr  *rcvrs = NULL;
1181 
1182 	user->valid = false;
1183 
1184 	if (user->handler->ipmi_watchdog_pretimeout)
1185 		atomic_dec(&intf->event_waiters);
1186 
1187 	if (user->gets_events)
1188 		atomic_dec(&intf->event_waiters);
1189 
1190 	/* Remove the user from the interface's sequence table. */
1191 	spin_lock_irqsave(&intf->seq_lock, flags);
1192 	list_del_rcu(&user->link);
1193 
1194 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
1195 		if (intf->seq_table[i].inuse
1196 		    && (intf->seq_table[i].recv_msg->user == user)) {
1197 			intf->seq_table[i].inuse = 0;
1198 			ipmi_free_recv_msg(intf->seq_table[i].recv_msg);
1199 		}
1200 	}
1201 	spin_unlock_irqrestore(&intf->seq_lock, flags);
1202 
1203 	/*
1204 	 * Remove the user from the command receiver's table.  First
1205 	 * we build a list of everything (not using the standard link,
1206 	 * since other things may be using it till we do
1207 	 * synchronize_rcu()) then free everything in that list.
1208 	 */
1209 	mutex_lock(&intf->cmd_rcvrs_mutex);
1210 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) {
1211 		if (rcvr->user == user) {
1212 			list_del_rcu(&rcvr->link);
1213 			rcvr->next = rcvrs;
1214 			rcvrs = rcvr;
1215 		}
1216 	}
1217 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1218 	synchronize_rcu();
1219 	while (rcvrs) {
1220 		rcvr = rcvrs;
1221 		rcvrs = rcvr->next;
1222 		kfree(rcvr);
1223 	}
1224 
1225 	mutex_lock(&ipmi_interfaces_mutex);
1226 	if (intf->handlers) {
1227 		module_put(intf->handlers->owner);
1228 		if (intf->handlers->dec_usecount)
1229 			intf->handlers->dec_usecount(intf->send_info);
1230 	}
1231 	mutex_unlock(&ipmi_interfaces_mutex);
1232 
1233 	kref_put(&intf->refcount, intf_free);
1234 
1235 	kref_put(&user->refcount, free_user);
1236 
1237 	return 0;
1238 }
1239 EXPORT_SYMBOL(ipmi_destroy_user);
1240 
1241 int ipmi_get_version(ipmi_user_t   user,
1242 		     unsigned char *major,
1243 		     unsigned char *minor)
1244 {
1245 	struct ipmi_device_id id;
1246 	int rv;
1247 
1248 	rv = bmc_get_device_id(user->intf, NULL, &id, NULL, NULL);
1249 	if (rv)
1250 		return rv;
1251 
1252 	*major = ipmi_version_major(&id);
1253 	*minor = ipmi_version_minor(&id);
1254 
1255 	return 0;
1256 }
1257 EXPORT_SYMBOL(ipmi_get_version);
1258 
1259 int ipmi_set_my_address(ipmi_user_t   user,
1260 			unsigned int  channel,
1261 			unsigned char address)
1262 {
1263 	if (channel >= IPMI_MAX_CHANNELS)
1264 		return -EINVAL;
1265 	user->intf->addrinfo[channel].address = address;
1266 	return 0;
1267 }
1268 EXPORT_SYMBOL(ipmi_set_my_address);
1269 
1270 int ipmi_get_my_address(ipmi_user_t   user,
1271 			unsigned int  channel,
1272 			unsigned char *address)
1273 {
1274 	if (channel >= IPMI_MAX_CHANNELS)
1275 		return -EINVAL;
1276 	*address = user->intf->addrinfo[channel].address;
1277 	return 0;
1278 }
1279 EXPORT_SYMBOL(ipmi_get_my_address);
1280 
1281 int ipmi_set_my_LUN(ipmi_user_t   user,
1282 		    unsigned int  channel,
1283 		    unsigned char LUN)
1284 {
1285 	if (channel >= IPMI_MAX_CHANNELS)
1286 		return -EINVAL;
1287 	user->intf->addrinfo[channel].lun = LUN & 0x3;
1288 	return 0;
1289 }
1290 EXPORT_SYMBOL(ipmi_set_my_LUN);
1291 
1292 int ipmi_get_my_LUN(ipmi_user_t   user,
1293 		    unsigned int  channel,
1294 		    unsigned char *address)
1295 {
1296 	if (channel >= IPMI_MAX_CHANNELS)
1297 		return -EINVAL;
1298 	*address = user->intf->addrinfo[channel].lun;
1299 	return 0;
1300 }
1301 EXPORT_SYMBOL(ipmi_get_my_LUN);
1302 
1303 int ipmi_get_maintenance_mode(ipmi_user_t user)
1304 {
1305 	int           mode;
1306 	unsigned long flags;
1307 
1308 	spin_lock_irqsave(&user->intf->maintenance_mode_lock, flags);
1309 	mode = user->intf->maintenance_mode;
1310 	spin_unlock_irqrestore(&user->intf->maintenance_mode_lock, flags);
1311 
1312 	return mode;
1313 }
1314 EXPORT_SYMBOL(ipmi_get_maintenance_mode);
1315 
1316 static void maintenance_mode_update(ipmi_smi_t intf)
1317 {
1318 	if (intf->handlers->set_maintenance_mode)
1319 		intf->handlers->set_maintenance_mode(
1320 			intf->send_info, intf->maintenance_mode_enable);
1321 }
1322 
1323 int ipmi_set_maintenance_mode(ipmi_user_t user, int mode)
1324 {
1325 	int           rv = 0;
1326 	unsigned long flags;
1327 	ipmi_smi_t    intf = user->intf;
1328 
1329 	spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
1330 	if (intf->maintenance_mode != mode) {
1331 		switch (mode) {
1332 		case IPMI_MAINTENANCE_MODE_AUTO:
1333 			intf->maintenance_mode_enable
1334 				= (intf->auto_maintenance_timeout > 0);
1335 			break;
1336 
1337 		case IPMI_MAINTENANCE_MODE_OFF:
1338 			intf->maintenance_mode_enable = false;
1339 			break;
1340 
1341 		case IPMI_MAINTENANCE_MODE_ON:
1342 			intf->maintenance_mode_enable = true;
1343 			break;
1344 
1345 		default:
1346 			rv = -EINVAL;
1347 			goto out_unlock;
1348 		}
1349 		intf->maintenance_mode = mode;
1350 
1351 		maintenance_mode_update(intf);
1352 	}
1353  out_unlock:
1354 	spin_unlock_irqrestore(&intf->maintenance_mode_lock, flags);
1355 
1356 	return rv;
1357 }
1358 EXPORT_SYMBOL(ipmi_set_maintenance_mode);
1359 
1360 int ipmi_set_gets_events(ipmi_user_t user, bool val)
1361 {
1362 	unsigned long        flags;
1363 	ipmi_smi_t           intf = user->intf;
1364 	struct ipmi_recv_msg *msg, *msg2;
1365 	struct list_head     msgs;
1366 
1367 	INIT_LIST_HEAD(&msgs);
1368 
1369 	spin_lock_irqsave(&intf->events_lock, flags);
1370 	if (user->gets_events == val)
1371 		goto out;
1372 
1373 	user->gets_events = val;
1374 
1375 	if (val) {
1376 		if (atomic_inc_return(&intf->event_waiters) == 1)
1377 			need_waiter(intf);
1378 	} else {
1379 		atomic_dec(&intf->event_waiters);
1380 	}
1381 
1382 	if (intf->delivering_events)
1383 		/*
1384 		 * Another thread is delivering events for this, so
1385 		 * let it handle any new events.
1386 		 */
1387 		goto out;
1388 
1389 	/* Deliver any queued events. */
1390 	while (user->gets_events && !list_empty(&intf->waiting_events)) {
1391 		list_for_each_entry_safe(msg, msg2, &intf->waiting_events, link)
1392 			list_move_tail(&msg->link, &msgs);
1393 		intf->waiting_events_count = 0;
1394 		if (intf->event_msg_printed) {
1395 			dev_warn(intf->si_dev,
1396 				 PFX "Event queue no longer full\n");
1397 			intf->event_msg_printed = 0;
1398 		}
1399 
1400 		intf->delivering_events = 1;
1401 		spin_unlock_irqrestore(&intf->events_lock, flags);
1402 
1403 		list_for_each_entry_safe(msg, msg2, &msgs, link) {
1404 			msg->user = user;
1405 			kref_get(&user->refcount);
1406 			deliver_response(msg);
1407 		}
1408 
1409 		spin_lock_irqsave(&intf->events_lock, flags);
1410 		intf->delivering_events = 0;
1411 	}
1412 
1413  out:
1414 	spin_unlock_irqrestore(&intf->events_lock, flags);
1415 
1416 	return 0;
1417 }
1418 EXPORT_SYMBOL(ipmi_set_gets_events);
1419 
1420 static struct cmd_rcvr *find_cmd_rcvr(ipmi_smi_t    intf,
1421 				      unsigned char netfn,
1422 				      unsigned char cmd,
1423 				      unsigned char chan)
1424 {
1425 	struct cmd_rcvr *rcvr;
1426 
1427 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) {
1428 		if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
1429 					&& (rcvr->chans & (1 << chan)))
1430 			return rcvr;
1431 	}
1432 	return NULL;
1433 }
1434 
1435 static int is_cmd_rcvr_exclusive(ipmi_smi_t    intf,
1436 				 unsigned char netfn,
1437 				 unsigned char cmd,
1438 				 unsigned int  chans)
1439 {
1440 	struct cmd_rcvr *rcvr;
1441 
1442 	list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) {
1443 		if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
1444 					&& (rcvr->chans & chans))
1445 			return 0;
1446 	}
1447 	return 1;
1448 }
1449 
1450 int ipmi_register_for_cmd(ipmi_user_t   user,
1451 			  unsigned char netfn,
1452 			  unsigned char cmd,
1453 			  unsigned int  chans)
1454 {
1455 	ipmi_smi_t      intf = user->intf;
1456 	struct cmd_rcvr *rcvr;
1457 	int             rv = 0;
1458 
1459 
1460 	rcvr = kmalloc(sizeof(*rcvr), GFP_KERNEL);
1461 	if (!rcvr)
1462 		return -ENOMEM;
1463 	rcvr->cmd = cmd;
1464 	rcvr->netfn = netfn;
1465 	rcvr->chans = chans;
1466 	rcvr->user = user;
1467 
1468 	mutex_lock(&intf->cmd_rcvrs_mutex);
1469 	/* Make sure the command/netfn is not already registered. */
1470 	if (!is_cmd_rcvr_exclusive(intf, netfn, cmd, chans)) {
1471 		rv = -EBUSY;
1472 		goto out_unlock;
1473 	}
1474 
1475 	if (atomic_inc_return(&intf->event_waiters) == 1)
1476 		need_waiter(intf);
1477 
1478 	list_add_rcu(&rcvr->link, &intf->cmd_rcvrs);
1479 
1480  out_unlock:
1481 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1482 	if (rv)
1483 		kfree(rcvr);
1484 
1485 	return rv;
1486 }
1487 EXPORT_SYMBOL(ipmi_register_for_cmd);
1488 
1489 int ipmi_unregister_for_cmd(ipmi_user_t   user,
1490 			    unsigned char netfn,
1491 			    unsigned char cmd,
1492 			    unsigned int  chans)
1493 {
1494 	ipmi_smi_t      intf = user->intf;
1495 	struct cmd_rcvr *rcvr;
1496 	struct cmd_rcvr *rcvrs = NULL;
1497 	int i, rv = -ENOENT;
1498 
1499 	mutex_lock(&intf->cmd_rcvrs_mutex);
1500 	for (i = 0; i < IPMI_NUM_CHANNELS; i++) {
1501 		if (((1 << i) & chans) == 0)
1502 			continue;
1503 		rcvr = find_cmd_rcvr(intf, netfn, cmd, i);
1504 		if (rcvr == NULL)
1505 			continue;
1506 		if (rcvr->user == user) {
1507 			rv = 0;
1508 			rcvr->chans &= ~chans;
1509 			if (rcvr->chans == 0) {
1510 				list_del_rcu(&rcvr->link);
1511 				rcvr->next = rcvrs;
1512 				rcvrs = rcvr;
1513 			}
1514 		}
1515 	}
1516 	mutex_unlock(&intf->cmd_rcvrs_mutex);
1517 	synchronize_rcu();
1518 	while (rcvrs) {
1519 		atomic_dec(&intf->event_waiters);
1520 		rcvr = rcvrs;
1521 		rcvrs = rcvr->next;
1522 		kfree(rcvr);
1523 	}
1524 	return rv;
1525 }
1526 EXPORT_SYMBOL(ipmi_unregister_for_cmd);
1527 
1528 static unsigned char
1529 ipmb_checksum(unsigned char *data, int size)
1530 {
1531 	unsigned char csum = 0;
1532 
1533 	for (; size > 0; size--, data++)
1534 		csum += *data;
1535 
1536 	return -csum;
1537 }
1538 
1539 static inline void format_ipmb_msg(struct ipmi_smi_msg   *smi_msg,
1540 				   struct kernel_ipmi_msg *msg,
1541 				   struct ipmi_ipmb_addr *ipmb_addr,
1542 				   long                  msgid,
1543 				   unsigned char         ipmb_seq,
1544 				   int                   broadcast,
1545 				   unsigned char         source_address,
1546 				   unsigned char         source_lun)
1547 {
1548 	int i = broadcast;
1549 
1550 	/* Format the IPMB header data. */
1551 	smi_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
1552 	smi_msg->data[1] = IPMI_SEND_MSG_CMD;
1553 	smi_msg->data[2] = ipmb_addr->channel;
1554 	if (broadcast)
1555 		smi_msg->data[3] = 0;
1556 	smi_msg->data[i+3] = ipmb_addr->slave_addr;
1557 	smi_msg->data[i+4] = (msg->netfn << 2) | (ipmb_addr->lun & 0x3);
1558 	smi_msg->data[i+5] = ipmb_checksum(&(smi_msg->data[i+3]), 2);
1559 	smi_msg->data[i+6] = source_address;
1560 	smi_msg->data[i+7] = (ipmb_seq << 2) | source_lun;
1561 	smi_msg->data[i+8] = msg->cmd;
1562 
1563 	/* Now tack on the data to the message. */
1564 	if (msg->data_len > 0)
1565 		memcpy(&(smi_msg->data[i+9]), msg->data,
1566 		       msg->data_len);
1567 	smi_msg->data_size = msg->data_len + 9;
1568 
1569 	/* Now calculate the checksum and tack it on. */
1570 	smi_msg->data[i+smi_msg->data_size]
1571 		= ipmb_checksum(&(smi_msg->data[i+6]),
1572 				smi_msg->data_size-6);
1573 
1574 	/*
1575 	 * Add on the checksum size and the offset from the
1576 	 * broadcast.
1577 	 */
1578 	smi_msg->data_size += 1 + i;
1579 
1580 	smi_msg->msgid = msgid;
1581 }
1582 
1583 static inline void format_lan_msg(struct ipmi_smi_msg   *smi_msg,
1584 				  struct kernel_ipmi_msg *msg,
1585 				  struct ipmi_lan_addr  *lan_addr,
1586 				  long                  msgid,
1587 				  unsigned char         ipmb_seq,
1588 				  unsigned char         source_lun)
1589 {
1590 	/* Format the IPMB header data. */
1591 	smi_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
1592 	smi_msg->data[1] = IPMI_SEND_MSG_CMD;
1593 	smi_msg->data[2] = lan_addr->channel;
1594 	smi_msg->data[3] = lan_addr->session_handle;
1595 	smi_msg->data[4] = lan_addr->remote_SWID;
1596 	smi_msg->data[5] = (msg->netfn << 2) | (lan_addr->lun & 0x3);
1597 	smi_msg->data[6] = ipmb_checksum(&(smi_msg->data[4]), 2);
1598 	smi_msg->data[7] = lan_addr->local_SWID;
1599 	smi_msg->data[8] = (ipmb_seq << 2) | source_lun;
1600 	smi_msg->data[9] = msg->cmd;
1601 
1602 	/* Now tack on the data to the message. */
1603 	if (msg->data_len > 0)
1604 		memcpy(&(smi_msg->data[10]), msg->data,
1605 		       msg->data_len);
1606 	smi_msg->data_size = msg->data_len + 10;
1607 
1608 	/* Now calculate the checksum and tack it on. */
1609 	smi_msg->data[smi_msg->data_size]
1610 		= ipmb_checksum(&(smi_msg->data[7]),
1611 				smi_msg->data_size-7);
1612 
1613 	/*
1614 	 * Add on the checksum size and the offset from the
1615 	 * broadcast.
1616 	 */
1617 	smi_msg->data_size += 1;
1618 
1619 	smi_msg->msgid = msgid;
1620 }
1621 
1622 static struct ipmi_smi_msg *smi_add_send_msg(ipmi_smi_t intf,
1623 					     struct ipmi_smi_msg *smi_msg,
1624 					     int priority)
1625 {
1626 	if (intf->curr_msg) {
1627 		if (priority > 0)
1628 			list_add_tail(&smi_msg->link, &intf->hp_xmit_msgs);
1629 		else
1630 			list_add_tail(&smi_msg->link, &intf->xmit_msgs);
1631 		smi_msg = NULL;
1632 	} else {
1633 		intf->curr_msg = smi_msg;
1634 	}
1635 
1636 	return smi_msg;
1637 }
1638 
1639 
1640 static void smi_send(ipmi_smi_t intf, const struct ipmi_smi_handlers *handlers,
1641 		     struct ipmi_smi_msg *smi_msg, int priority)
1642 {
1643 	int run_to_completion = intf->run_to_completion;
1644 
1645 	if (run_to_completion) {
1646 		smi_msg = smi_add_send_msg(intf, smi_msg, priority);
1647 	} else {
1648 		unsigned long flags;
1649 
1650 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
1651 		smi_msg = smi_add_send_msg(intf, smi_msg, priority);
1652 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
1653 	}
1654 
1655 	if (smi_msg)
1656 		handlers->sender(intf->send_info, smi_msg);
1657 }
1658 
1659 /*
1660  * Separate from ipmi_request so that the user does not have to be
1661  * supplied in certain circumstances (mainly at panic time).  If
1662  * messages are supplied, they will be freed, even if an error
1663  * occurs.
1664  */
1665 static int i_ipmi_request(ipmi_user_t          user,
1666 			  ipmi_smi_t           intf,
1667 			  struct ipmi_addr     *addr,
1668 			  long                 msgid,
1669 			  struct kernel_ipmi_msg *msg,
1670 			  void                 *user_msg_data,
1671 			  void                 *supplied_smi,
1672 			  struct ipmi_recv_msg *supplied_recv,
1673 			  int                  priority,
1674 			  unsigned char        source_address,
1675 			  unsigned char        source_lun,
1676 			  int                  retries,
1677 			  unsigned int         retry_time_ms)
1678 {
1679 	int                      rv = 0;
1680 	struct ipmi_smi_msg      *smi_msg;
1681 	struct ipmi_recv_msg     *recv_msg;
1682 	unsigned long            flags;
1683 
1684 
1685 	if (supplied_recv)
1686 		recv_msg = supplied_recv;
1687 	else {
1688 		recv_msg = ipmi_alloc_recv_msg();
1689 		if (recv_msg == NULL)
1690 			return -ENOMEM;
1691 	}
1692 	recv_msg->user_msg_data = user_msg_data;
1693 
1694 	if (supplied_smi)
1695 		smi_msg = (struct ipmi_smi_msg *) supplied_smi;
1696 	else {
1697 		smi_msg = ipmi_alloc_smi_msg();
1698 		if (smi_msg == NULL) {
1699 			ipmi_free_recv_msg(recv_msg);
1700 			return -ENOMEM;
1701 		}
1702 	}
1703 
1704 	rcu_read_lock();
1705 	if (intf->in_shutdown) {
1706 		rv = -ENODEV;
1707 		goto out_err;
1708 	}
1709 
1710 	recv_msg->user = user;
1711 	if (user)
1712 		kref_get(&user->refcount);
1713 	recv_msg->msgid = msgid;
1714 	/*
1715 	 * Store the message to send in the receive message so timeout
1716 	 * responses can get the proper response data.
1717 	 */
1718 	recv_msg->msg = *msg;
1719 
1720 	if (addr->addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE) {
1721 		struct ipmi_system_interface_addr *smi_addr;
1722 
1723 		if (msg->netfn & 1) {
1724 			/* Responses are not allowed to the SMI. */
1725 			rv = -EINVAL;
1726 			goto out_err;
1727 		}
1728 
1729 		smi_addr = (struct ipmi_system_interface_addr *) addr;
1730 		if (smi_addr->lun > 3) {
1731 			ipmi_inc_stat(intf, sent_invalid_commands);
1732 			rv = -EINVAL;
1733 			goto out_err;
1734 		}
1735 
1736 		memcpy(&recv_msg->addr, smi_addr, sizeof(*smi_addr));
1737 
1738 		if ((msg->netfn == IPMI_NETFN_APP_REQUEST)
1739 		    && ((msg->cmd == IPMI_SEND_MSG_CMD)
1740 			|| (msg->cmd == IPMI_GET_MSG_CMD)
1741 			|| (msg->cmd == IPMI_READ_EVENT_MSG_BUFFER_CMD))) {
1742 			/*
1743 			 * We don't let the user do these, since we manage
1744 			 * the sequence numbers.
1745 			 */
1746 			ipmi_inc_stat(intf, sent_invalid_commands);
1747 			rv = -EINVAL;
1748 			goto out_err;
1749 		}
1750 
1751 		if (((msg->netfn == IPMI_NETFN_APP_REQUEST)
1752 		      && ((msg->cmd == IPMI_COLD_RESET_CMD)
1753 			  || (msg->cmd == IPMI_WARM_RESET_CMD)))
1754 		     || (msg->netfn == IPMI_NETFN_FIRMWARE_REQUEST)) {
1755 			spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
1756 			intf->auto_maintenance_timeout
1757 				= IPMI_MAINTENANCE_MODE_TIMEOUT;
1758 			if (!intf->maintenance_mode
1759 			    && !intf->maintenance_mode_enable) {
1760 				intf->maintenance_mode_enable = true;
1761 				maintenance_mode_update(intf);
1762 			}
1763 			spin_unlock_irqrestore(&intf->maintenance_mode_lock,
1764 					       flags);
1765 		}
1766 
1767 		if ((msg->data_len + 2) > IPMI_MAX_MSG_LENGTH) {
1768 			ipmi_inc_stat(intf, sent_invalid_commands);
1769 			rv = -EMSGSIZE;
1770 			goto out_err;
1771 		}
1772 
1773 		smi_msg->data[0] = (msg->netfn << 2) | (smi_addr->lun & 0x3);
1774 		smi_msg->data[1] = msg->cmd;
1775 		smi_msg->msgid = msgid;
1776 		smi_msg->user_data = recv_msg;
1777 		if (msg->data_len > 0)
1778 			memcpy(&(smi_msg->data[2]), msg->data, msg->data_len);
1779 		smi_msg->data_size = msg->data_len + 2;
1780 		ipmi_inc_stat(intf, sent_local_commands);
1781 	} else if (is_ipmb_addr(addr) || is_ipmb_bcast_addr(addr)) {
1782 		struct ipmi_ipmb_addr *ipmb_addr;
1783 		unsigned char         ipmb_seq;
1784 		long                  seqid;
1785 		int                   broadcast = 0;
1786 		struct ipmi_channel   *chans;
1787 
1788 		if (addr->channel >= IPMI_MAX_CHANNELS) {
1789 			ipmi_inc_stat(intf, sent_invalid_commands);
1790 			rv = -EINVAL;
1791 			goto out_err;
1792 		}
1793 
1794 		chans = READ_ONCE(intf->channel_list)->c;
1795 
1796 		if (chans[addr->channel].medium != IPMI_CHANNEL_MEDIUM_IPMB) {
1797 			ipmi_inc_stat(intf, sent_invalid_commands);
1798 			rv = -EINVAL;
1799 			goto out_err;
1800 		}
1801 
1802 		if (retries < 0) {
1803 		    if (addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE)
1804 			retries = 0; /* Don't retry broadcasts. */
1805 		    else
1806 			retries = 4;
1807 		}
1808 		if (addr->addr_type == IPMI_IPMB_BROADCAST_ADDR_TYPE) {
1809 		    /*
1810 		     * Broadcasts add a zero at the beginning of the
1811 		     * message, but otherwise is the same as an IPMB
1812 		     * address.
1813 		     */
1814 		    addr->addr_type = IPMI_IPMB_ADDR_TYPE;
1815 		    broadcast = 1;
1816 		}
1817 
1818 
1819 		/* Default to 1 second retries. */
1820 		if (retry_time_ms == 0)
1821 		    retry_time_ms = 1000;
1822 
1823 		/*
1824 		 * 9 for the header and 1 for the checksum, plus
1825 		 * possibly one for the broadcast.
1826 		 */
1827 		if ((msg->data_len + 10 + broadcast) > IPMI_MAX_MSG_LENGTH) {
1828 			ipmi_inc_stat(intf, sent_invalid_commands);
1829 			rv = -EMSGSIZE;
1830 			goto out_err;
1831 		}
1832 
1833 		ipmb_addr = (struct ipmi_ipmb_addr *) addr;
1834 		if (ipmb_addr->lun > 3) {
1835 			ipmi_inc_stat(intf, sent_invalid_commands);
1836 			rv = -EINVAL;
1837 			goto out_err;
1838 		}
1839 
1840 		memcpy(&recv_msg->addr, ipmb_addr, sizeof(*ipmb_addr));
1841 
1842 		if (recv_msg->msg.netfn & 0x1) {
1843 			/*
1844 			 * It's a response, so use the user's sequence
1845 			 * from msgid.
1846 			 */
1847 			ipmi_inc_stat(intf, sent_ipmb_responses);
1848 			format_ipmb_msg(smi_msg, msg, ipmb_addr, msgid,
1849 					msgid, broadcast,
1850 					source_address, source_lun);
1851 
1852 			/*
1853 			 * Save the receive message so we can use it
1854 			 * to deliver the response.
1855 			 */
1856 			smi_msg->user_data = recv_msg;
1857 		} else {
1858 			/* It's a command, so get a sequence for it. */
1859 
1860 			spin_lock_irqsave(&(intf->seq_lock), flags);
1861 
1862 			/*
1863 			 * Create a sequence number with a 1 second
1864 			 * timeout and 4 retries.
1865 			 */
1866 			rv = intf_next_seq(intf,
1867 					   recv_msg,
1868 					   retry_time_ms,
1869 					   retries,
1870 					   broadcast,
1871 					   &ipmb_seq,
1872 					   &seqid);
1873 			if (rv) {
1874 				/*
1875 				 * We have used up all the sequence numbers,
1876 				 * probably, so abort.
1877 				 */
1878 				spin_unlock_irqrestore(&(intf->seq_lock),
1879 						       flags);
1880 				goto out_err;
1881 			}
1882 
1883 			ipmi_inc_stat(intf, sent_ipmb_commands);
1884 
1885 			/*
1886 			 * Store the sequence number in the message,
1887 			 * so that when the send message response
1888 			 * comes back we can start the timer.
1889 			 */
1890 			format_ipmb_msg(smi_msg, msg, ipmb_addr,
1891 					STORE_SEQ_IN_MSGID(ipmb_seq, seqid),
1892 					ipmb_seq, broadcast,
1893 					source_address, source_lun);
1894 
1895 			/*
1896 			 * Copy the message into the recv message data, so we
1897 			 * can retransmit it later if necessary.
1898 			 */
1899 			memcpy(recv_msg->msg_data, smi_msg->data,
1900 			       smi_msg->data_size);
1901 			recv_msg->msg.data = recv_msg->msg_data;
1902 			recv_msg->msg.data_len = smi_msg->data_size;
1903 
1904 			/*
1905 			 * We don't unlock until here, because we need
1906 			 * to copy the completed message into the
1907 			 * recv_msg before we release the lock.
1908 			 * Otherwise, race conditions may bite us.  I
1909 			 * know that's pretty paranoid, but I prefer
1910 			 * to be correct.
1911 			 */
1912 			spin_unlock_irqrestore(&(intf->seq_lock), flags);
1913 		}
1914 	} else if (is_lan_addr(addr)) {
1915 		struct ipmi_lan_addr  *lan_addr;
1916 		unsigned char         ipmb_seq;
1917 		long                  seqid;
1918 		struct ipmi_channel   *chans;
1919 
1920 		if (addr->channel >= IPMI_MAX_CHANNELS) {
1921 			ipmi_inc_stat(intf, sent_invalid_commands);
1922 			rv = -EINVAL;
1923 			goto out_err;
1924 		}
1925 
1926 		chans = READ_ONCE(intf->channel_list)->c;
1927 
1928 		if ((chans[addr->channel].medium
1929 				!= IPMI_CHANNEL_MEDIUM_8023LAN)
1930 		    && (chans[addr->channel].medium
1931 				!= IPMI_CHANNEL_MEDIUM_ASYNC)) {
1932 			ipmi_inc_stat(intf, sent_invalid_commands);
1933 			rv = -EINVAL;
1934 			goto out_err;
1935 		}
1936 
1937 		retries = 4;
1938 
1939 		/* Default to 1 second retries. */
1940 		if (retry_time_ms == 0)
1941 		    retry_time_ms = 1000;
1942 
1943 		/* 11 for the header and 1 for the checksum. */
1944 		if ((msg->data_len + 12) > IPMI_MAX_MSG_LENGTH) {
1945 			ipmi_inc_stat(intf, sent_invalid_commands);
1946 			rv = -EMSGSIZE;
1947 			goto out_err;
1948 		}
1949 
1950 		lan_addr = (struct ipmi_lan_addr *) addr;
1951 		if (lan_addr->lun > 3) {
1952 			ipmi_inc_stat(intf, sent_invalid_commands);
1953 			rv = -EINVAL;
1954 			goto out_err;
1955 		}
1956 
1957 		memcpy(&recv_msg->addr, lan_addr, sizeof(*lan_addr));
1958 
1959 		if (recv_msg->msg.netfn & 0x1) {
1960 			/*
1961 			 * It's a response, so use the user's sequence
1962 			 * from msgid.
1963 			 */
1964 			ipmi_inc_stat(intf, sent_lan_responses);
1965 			format_lan_msg(smi_msg, msg, lan_addr, msgid,
1966 				       msgid, source_lun);
1967 
1968 			/*
1969 			 * Save the receive message so we can use it
1970 			 * to deliver the response.
1971 			 */
1972 			smi_msg->user_data = recv_msg;
1973 		} else {
1974 			/* It's a command, so get a sequence for it. */
1975 
1976 			spin_lock_irqsave(&(intf->seq_lock), flags);
1977 
1978 			/*
1979 			 * Create a sequence number with a 1 second
1980 			 * timeout and 4 retries.
1981 			 */
1982 			rv = intf_next_seq(intf,
1983 					   recv_msg,
1984 					   retry_time_ms,
1985 					   retries,
1986 					   0,
1987 					   &ipmb_seq,
1988 					   &seqid);
1989 			if (rv) {
1990 				/*
1991 				 * We have used up all the sequence numbers,
1992 				 * probably, so abort.
1993 				 */
1994 				spin_unlock_irqrestore(&(intf->seq_lock),
1995 						       flags);
1996 				goto out_err;
1997 			}
1998 
1999 			ipmi_inc_stat(intf, sent_lan_commands);
2000 
2001 			/*
2002 			 * Store the sequence number in the message,
2003 			 * so that when the send message response
2004 			 * comes back we can start the timer.
2005 			 */
2006 			format_lan_msg(smi_msg, msg, lan_addr,
2007 				       STORE_SEQ_IN_MSGID(ipmb_seq, seqid),
2008 				       ipmb_seq, source_lun);
2009 
2010 			/*
2011 			 * Copy the message into the recv message data, so we
2012 			 * can retransmit it later if necessary.
2013 			 */
2014 			memcpy(recv_msg->msg_data, smi_msg->data,
2015 			       smi_msg->data_size);
2016 			recv_msg->msg.data = recv_msg->msg_data;
2017 			recv_msg->msg.data_len = smi_msg->data_size;
2018 
2019 			/*
2020 			 * We don't unlock until here, because we need
2021 			 * to copy the completed message into the
2022 			 * recv_msg before we release the lock.
2023 			 * Otherwise, race conditions may bite us.  I
2024 			 * know that's pretty paranoid, but I prefer
2025 			 * to be correct.
2026 			 */
2027 			spin_unlock_irqrestore(&(intf->seq_lock), flags);
2028 		}
2029 	} else {
2030 	    /* Unknown address type. */
2031 		ipmi_inc_stat(intf, sent_invalid_commands);
2032 		rv = -EINVAL;
2033 		goto out_err;
2034 	}
2035 
2036 #ifdef DEBUG_MSGING
2037 	{
2038 		int m;
2039 		for (m = 0; m < smi_msg->data_size; m++)
2040 			printk(" %2.2x", smi_msg->data[m]);
2041 		printk("\n");
2042 	}
2043 #endif
2044 
2045 	smi_send(intf, intf->handlers, smi_msg, priority);
2046 	rcu_read_unlock();
2047 
2048 	return 0;
2049 
2050  out_err:
2051 	rcu_read_unlock();
2052 	ipmi_free_smi_msg(smi_msg);
2053 	ipmi_free_recv_msg(recv_msg);
2054 	return rv;
2055 }
2056 
2057 static int check_addr(ipmi_smi_t       intf,
2058 		      struct ipmi_addr *addr,
2059 		      unsigned char    *saddr,
2060 		      unsigned char    *lun)
2061 {
2062 	if (addr->channel >= IPMI_MAX_CHANNELS)
2063 		return -EINVAL;
2064 	*lun = intf->addrinfo[addr->channel].lun;
2065 	*saddr = intf->addrinfo[addr->channel].address;
2066 	return 0;
2067 }
2068 
2069 int ipmi_request_settime(ipmi_user_t      user,
2070 			 struct ipmi_addr *addr,
2071 			 long             msgid,
2072 			 struct kernel_ipmi_msg  *msg,
2073 			 void             *user_msg_data,
2074 			 int              priority,
2075 			 int              retries,
2076 			 unsigned int     retry_time_ms)
2077 {
2078 	unsigned char saddr = 0, lun = 0;
2079 	int           rv;
2080 
2081 	if (!user)
2082 		return -EINVAL;
2083 	rv = check_addr(user->intf, addr, &saddr, &lun);
2084 	if (rv)
2085 		return rv;
2086 	return i_ipmi_request(user,
2087 			      user->intf,
2088 			      addr,
2089 			      msgid,
2090 			      msg,
2091 			      user_msg_data,
2092 			      NULL, NULL,
2093 			      priority,
2094 			      saddr,
2095 			      lun,
2096 			      retries,
2097 			      retry_time_ms);
2098 }
2099 EXPORT_SYMBOL(ipmi_request_settime);
2100 
2101 int ipmi_request_supply_msgs(ipmi_user_t          user,
2102 			     struct ipmi_addr     *addr,
2103 			     long                 msgid,
2104 			     struct kernel_ipmi_msg *msg,
2105 			     void                 *user_msg_data,
2106 			     void                 *supplied_smi,
2107 			     struct ipmi_recv_msg *supplied_recv,
2108 			     int                  priority)
2109 {
2110 	unsigned char saddr = 0, lun = 0;
2111 	int           rv;
2112 
2113 	if (!user)
2114 		return -EINVAL;
2115 	rv = check_addr(user->intf, addr, &saddr, &lun);
2116 	if (rv)
2117 		return rv;
2118 	return i_ipmi_request(user,
2119 			      user->intf,
2120 			      addr,
2121 			      msgid,
2122 			      msg,
2123 			      user_msg_data,
2124 			      supplied_smi,
2125 			      supplied_recv,
2126 			      priority,
2127 			      saddr,
2128 			      lun,
2129 			      -1, 0);
2130 }
2131 EXPORT_SYMBOL(ipmi_request_supply_msgs);
2132 
2133 static void bmc_device_id_handler(ipmi_smi_t intf, struct ipmi_recv_msg *msg)
2134 {
2135 	int rv;
2136 
2137 	if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
2138 			|| (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE)
2139 			|| (msg->msg.cmd != IPMI_GET_DEVICE_ID_CMD)) {
2140 		dev_warn(intf->si_dev,
2141 			 PFX "invalid device_id msg: addr_type=%d netfn=%x cmd=%x\n",
2142 			msg->addr.addr_type, msg->msg.netfn, msg->msg.cmd);
2143 		return;
2144 	}
2145 
2146 	rv = ipmi_demangle_device_id(msg->msg.netfn, msg->msg.cmd,
2147 			msg->msg.data, msg->msg.data_len, &intf->bmc->fetch_id);
2148 	if (rv) {
2149 		dev_warn(intf->si_dev,
2150 			 PFX "device id demangle failed: %d\n", rv);
2151 		intf->bmc->dyn_id_set = 0;
2152 	} else {
2153 		/*
2154 		 * Make sure the id data is available before setting
2155 		 * dyn_id_set.
2156 		 */
2157 		smp_wmb();
2158 		intf->bmc->dyn_id_set = 1;
2159 	}
2160 
2161 	wake_up(&intf->waitq);
2162 }
2163 
2164 static int
2165 send_get_device_id_cmd(ipmi_smi_t intf)
2166 {
2167 	struct ipmi_system_interface_addr si;
2168 	struct kernel_ipmi_msg msg;
2169 
2170 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
2171 	si.channel = IPMI_BMC_CHANNEL;
2172 	si.lun = 0;
2173 
2174 	msg.netfn = IPMI_NETFN_APP_REQUEST;
2175 	msg.cmd = IPMI_GET_DEVICE_ID_CMD;
2176 	msg.data = NULL;
2177 	msg.data_len = 0;
2178 
2179 	return i_ipmi_request(NULL,
2180 			      intf,
2181 			      (struct ipmi_addr *) &si,
2182 			      0,
2183 			      &msg,
2184 			      intf,
2185 			      NULL,
2186 			      NULL,
2187 			      0,
2188 			      intf->addrinfo[0].address,
2189 			      intf->addrinfo[0].lun,
2190 			      -1, 0);
2191 }
2192 
2193 static int __get_device_id(ipmi_smi_t intf, struct bmc_device *bmc)
2194 {
2195 	int rv;
2196 
2197 	bmc->dyn_id_set = 2;
2198 
2199 	intf->null_user_handler = bmc_device_id_handler;
2200 
2201 	rv = send_get_device_id_cmd(intf);
2202 	if (rv)
2203 		return rv;
2204 
2205 	wait_event(intf->waitq, bmc->dyn_id_set != 2);
2206 
2207 	if (!bmc->dyn_id_set)
2208 		rv = -EIO; /* Something went wrong in the fetch. */
2209 
2210 	/* dyn_id_set makes the id data available. */
2211 	smp_rmb();
2212 
2213 	intf->null_user_handler = NULL;
2214 
2215 	return rv;
2216 }
2217 
2218 /*
2219  * Fetch the device id for the bmc/interface.  You must pass in either
2220  * bmc or intf, this code will get the other one.  If the data has
2221  * been recently fetched, this will just use the cached data.  Otherwise
2222  * it will run a new fetch.
2223  *
2224  * Except for the first time this is called (in ipmi_register_smi()),
2225  * this will always return good data;
2226  */
2227 static int __bmc_get_device_id(ipmi_smi_t intf, struct bmc_device *bmc,
2228 			       struct ipmi_device_id *id,
2229 			       bool *guid_set, guid_t *guid, int intf_num)
2230 {
2231 	int rv = 0;
2232 	int prev_dyn_id_set, prev_guid_set;
2233 	bool intf_set = intf != NULL;
2234 
2235 	if (!intf) {
2236 		mutex_lock(&bmc->dyn_mutex);
2237 retry_bmc_lock:
2238 		if (list_empty(&bmc->intfs)) {
2239 			mutex_unlock(&bmc->dyn_mutex);
2240 			return -ENOENT;
2241 		}
2242 		intf = list_first_entry(&bmc->intfs, struct ipmi_smi,
2243 					bmc_link);
2244 		kref_get(&intf->refcount);
2245 		mutex_unlock(&bmc->dyn_mutex);
2246 		mutex_lock(&intf->bmc_reg_mutex);
2247 		mutex_lock(&bmc->dyn_mutex);
2248 		if (intf != list_first_entry(&bmc->intfs, struct ipmi_smi,
2249 					     bmc_link)) {
2250 			mutex_unlock(&intf->bmc_reg_mutex);
2251 			kref_put(&intf->refcount, intf_free);
2252 			goto retry_bmc_lock;
2253 		}
2254 	} else {
2255 		mutex_lock(&intf->bmc_reg_mutex);
2256 		bmc = intf->bmc;
2257 		mutex_lock(&bmc->dyn_mutex);
2258 		kref_get(&intf->refcount);
2259 	}
2260 
2261 	/* If we have a valid and current ID, just return that. */
2262 	if (intf->in_bmc_register ||
2263 	    (bmc->dyn_id_set && time_is_after_jiffies(bmc->dyn_id_expiry)))
2264 		goto out_noprocessing;
2265 
2266 	prev_guid_set = bmc->dyn_guid_set;
2267 	__get_guid(intf);
2268 
2269 	prev_dyn_id_set = bmc->dyn_id_set;
2270 	rv = __get_device_id(intf, bmc);
2271 	if (rv)
2272 		goto out;
2273 
2274 	/*
2275 	 * The guid, device id, manufacturer id, and product id should
2276 	 * not change on a BMC.  If it does we have to do some dancing.
2277 	 */
2278 	if (!intf->bmc_registered
2279 	    || (!prev_guid_set && bmc->dyn_guid_set)
2280 	    || (!prev_dyn_id_set && bmc->dyn_id_set)
2281 	    || (prev_guid_set && bmc->dyn_guid_set
2282 		&& !guid_equal(&bmc->guid, &bmc->fetch_guid))
2283 	    || bmc->id.device_id != bmc->fetch_id.device_id
2284 	    || bmc->id.manufacturer_id != bmc->fetch_id.manufacturer_id
2285 	    || bmc->id.product_id != bmc->fetch_id.product_id) {
2286 		struct ipmi_device_id id = bmc->fetch_id;
2287 		int guid_set = bmc->dyn_guid_set;
2288 		guid_t guid;
2289 
2290 		guid = bmc->fetch_guid;
2291 		mutex_unlock(&bmc->dyn_mutex);
2292 
2293 		__ipmi_bmc_unregister(intf);
2294 		/* Fill in the temporary BMC for good measure. */
2295 		intf->bmc->id = id;
2296 		intf->bmc->dyn_guid_set = guid_set;
2297 		intf->bmc->guid = guid;
2298 		if (__ipmi_bmc_register(intf, &id, guid_set, &guid, intf_num))
2299 			need_waiter(intf); /* Retry later on an error. */
2300 		else
2301 			__scan_channels(intf, &id);
2302 
2303 
2304 		if (!intf_set) {
2305 			/*
2306 			 * We weren't given the interface on the
2307 			 * command line, so restart the operation on
2308 			 * the next interface for the BMC.
2309 			 */
2310 			mutex_unlock(&intf->bmc_reg_mutex);
2311 			mutex_lock(&bmc->dyn_mutex);
2312 			goto retry_bmc_lock;
2313 		}
2314 
2315 		/* We have a new BMC, set it up. */
2316 		bmc = intf->bmc;
2317 		mutex_lock(&bmc->dyn_mutex);
2318 		goto out_noprocessing;
2319 	} else if (memcmp(&bmc->fetch_id, &bmc->id, sizeof(bmc->id)))
2320 		/* Version info changes, scan the channels again. */
2321 		__scan_channels(intf, &bmc->fetch_id);
2322 
2323 	bmc->dyn_id_expiry = jiffies + IPMI_DYN_DEV_ID_EXPIRY;
2324 
2325 out:
2326 	if (rv && prev_dyn_id_set) {
2327 		rv = 0; /* Ignore failures if we have previous data. */
2328 		bmc->dyn_id_set = prev_dyn_id_set;
2329 	}
2330 	if (!rv) {
2331 		bmc->id = bmc->fetch_id;
2332 		if (bmc->dyn_guid_set)
2333 			bmc->guid = bmc->fetch_guid;
2334 		else if (prev_guid_set)
2335 			/*
2336 			 * The guid used to be valid and it failed to fetch,
2337 			 * just use the cached value.
2338 			 */
2339 			bmc->dyn_guid_set = prev_guid_set;
2340 	}
2341 out_noprocessing:
2342 	if (!rv) {
2343 		if (id)
2344 			*id = bmc->id;
2345 
2346 		if (guid_set)
2347 			*guid_set = bmc->dyn_guid_set;
2348 
2349 		if (guid && bmc->dyn_guid_set)
2350 			*guid =  bmc->guid;
2351 	}
2352 
2353 	mutex_unlock(&bmc->dyn_mutex);
2354 	mutex_unlock(&intf->bmc_reg_mutex);
2355 
2356 	kref_put(&intf->refcount, intf_free);
2357 	return rv;
2358 }
2359 
2360 static int bmc_get_device_id(ipmi_smi_t intf, struct bmc_device *bmc,
2361 			     struct ipmi_device_id *id,
2362 			     bool *guid_set, guid_t *guid)
2363 {
2364 	return __bmc_get_device_id(intf, bmc, id, guid_set, guid, -1);
2365 }
2366 
2367 #ifdef CONFIG_IPMI_PROC_INTERFACE
2368 static int smi_ipmb_proc_show(struct seq_file *m, void *v)
2369 {
2370 	ipmi_smi_t intf = m->private;
2371 	int        i;
2372 
2373 	seq_printf(m, "%x", intf->addrinfo[0].address);
2374 	for (i = 1; i < IPMI_MAX_CHANNELS; i++)
2375 		seq_printf(m, " %x", intf->addrinfo[i].address);
2376 	seq_putc(m, '\n');
2377 
2378 	return 0;
2379 }
2380 
2381 static int smi_ipmb_proc_open(struct inode *inode, struct file *file)
2382 {
2383 	return single_open(file, smi_ipmb_proc_show, PDE_DATA(inode));
2384 }
2385 
2386 static const struct file_operations smi_ipmb_proc_ops = {
2387 	.open		= smi_ipmb_proc_open,
2388 	.read		= seq_read,
2389 	.llseek		= seq_lseek,
2390 	.release	= single_release,
2391 };
2392 
2393 static int smi_version_proc_show(struct seq_file *m, void *v)
2394 {
2395 	ipmi_smi_t intf = m->private;
2396 	struct ipmi_device_id id;
2397 	int rv;
2398 
2399 	rv = bmc_get_device_id(intf, NULL, &id, NULL, NULL);
2400 	if (rv)
2401 		return rv;
2402 
2403 	seq_printf(m, "%u.%u\n",
2404 		   ipmi_version_major(&id),
2405 		   ipmi_version_minor(&id));
2406 
2407 	return 0;
2408 }
2409 
2410 static int smi_version_proc_open(struct inode *inode, struct file *file)
2411 {
2412 	return single_open(file, smi_version_proc_show, PDE_DATA(inode));
2413 }
2414 
2415 static const struct file_operations smi_version_proc_ops = {
2416 	.open		= smi_version_proc_open,
2417 	.read		= seq_read,
2418 	.llseek		= seq_lseek,
2419 	.release	= single_release,
2420 };
2421 
2422 static int smi_stats_proc_show(struct seq_file *m, void *v)
2423 {
2424 	ipmi_smi_t intf = m->private;
2425 
2426 	seq_printf(m, "sent_invalid_commands:       %u\n",
2427 		       ipmi_get_stat(intf, sent_invalid_commands));
2428 	seq_printf(m, "sent_local_commands:         %u\n",
2429 		       ipmi_get_stat(intf, sent_local_commands));
2430 	seq_printf(m, "handled_local_responses:     %u\n",
2431 		       ipmi_get_stat(intf, handled_local_responses));
2432 	seq_printf(m, "unhandled_local_responses:   %u\n",
2433 		       ipmi_get_stat(intf, unhandled_local_responses));
2434 	seq_printf(m, "sent_ipmb_commands:          %u\n",
2435 		       ipmi_get_stat(intf, sent_ipmb_commands));
2436 	seq_printf(m, "sent_ipmb_command_errs:      %u\n",
2437 		       ipmi_get_stat(intf, sent_ipmb_command_errs));
2438 	seq_printf(m, "retransmitted_ipmb_commands: %u\n",
2439 		       ipmi_get_stat(intf, retransmitted_ipmb_commands));
2440 	seq_printf(m, "timed_out_ipmb_commands:     %u\n",
2441 		       ipmi_get_stat(intf, timed_out_ipmb_commands));
2442 	seq_printf(m, "timed_out_ipmb_broadcasts:   %u\n",
2443 		       ipmi_get_stat(intf, timed_out_ipmb_broadcasts));
2444 	seq_printf(m, "sent_ipmb_responses:         %u\n",
2445 		       ipmi_get_stat(intf, sent_ipmb_responses));
2446 	seq_printf(m, "handled_ipmb_responses:      %u\n",
2447 		       ipmi_get_stat(intf, handled_ipmb_responses));
2448 	seq_printf(m, "invalid_ipmb_responses:      %u\n",
2449 		       ipmi_get_stat(intf, invalid_ipmb_responses));
2450 	seq_printf(m, "unhandled_ipmb_responses:    %u\n",
2451 		       ipmi_get_stat(intf, unhandled_ipmb_responses));
2452 	seq_printf(m, "sent_lan_commands:           %u\n",
2453 		       ipmi_get_stat(intf, sent_lan_commands));
2454 	seq_printf(m, "sent_lan_command_errs:       %u\n",
2455 		       ipmi_get_stat(intf, sent_lan_command_errs));
2456 	seq_printf(m, "retransmitted_lan_commands:  %u\n",
2457 		       ipmi_get_stat(intf, retransmitted_lan_commands));
2458 	seq_printf(m, "timed_out_lan_commands:      %u\n",
2459 		       ipmi_get_stat(intf, timed_out_lan_commands));
2460 	seq_printf(m, "sent_lan_responses:          %u\n",
2461 		       ipmi_get_stat(intf, sent_lan_responses));
2462 	seq_printf(m, "handled_lan_responses:       %u\n",
2463 		       ipmi_get_stat(intf, handled_lan_responses));
2464 	seq_printf(m, "invalid_lan_responses:       %u\n",
2465 		       ipmi_get_stat(intf, invalid_lan_responses));
2466 	seq_printf(m, "unhandled_lan_responses:     %u\n",
2467 		       ipmi_get_stat(intf, unhandled_lan_responses));
2468 	seq_printf(m, "handled_commands:            %u\n",
2469 		       ipmi_get_stat(intf, handled_commands));
2470 	seq_printf(m, "invalid_commands:            %u\n",
2471 		       ipmi_get_stat(intf, invalid_commands));
2472 	seq_printf(m, "unhandled_commands:          %u\n",
2473 		       ipmi_get_stat(intf, unhandled_commands));
2474 	seq_printf(m, "invalid_events:              %u\n",
2475 		       ipmi_get_stat(intf, invalid_events));
2476 	seq_printf(m, "events:                      %u\n",
2477 		       ipmi_get_stat(intf, events));
2478 	seq_printf(m, "failed rexmit LAN msgs:      %u\n",
2479 		       ipmi_get_stat(intf, dropped_rexmit_lan_commands));
2480 	seq_printf(m, "failed rexmit IPMB msgs:     %u\n",
2481 		       ipmi_get_stat(intf, dropped_rexmit_ipmb_commands));
2482 	return 0;
2483 }
2484 
2485 static int smi_stats_proc_open(struct inode *inode, struct file *file)
2486 {
2487 	return single_open(file, smi_stats_proc_show, PDE_DATA(inode));
2488 }
2489 
2490 static const struct file_operations smi_stats_proc_ops = {
2491 	.open		= smi_stats_proc_open,
2492 	.read		= seq_read,
2493 	.llseek		= seq_lseek,
2494 	.release	= single_release,
2495 };
2496 
2497 int ipmi_smi_add_proc_entry(ipmi_smi_t smi, char *name,
2498 			    const struct file_operations *proc_ops,
2499 			    void *data)
2500 {
2501 	int                    rv = 0;
2502 	struct proc_dir_entry  *file;
2503 	struct ipmi_proc_entry *entry;
2504 
2505 	/* Create a list element. */
2506 	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
2507 	if (!entry)
2508 		return -ENOMEM;
2509 	entry->name = kstrdup(name, GFP_KERNEL);
2510 	if (!entry->name) {
2511 		kfree(entry);
2512 		return -ENOMEM;
2513 	}
2514 
2515 	file = proc_create_data(name, 0, smi->proc_dir, proc_ops, data);
2516 	if (!file) {
2517 		kfree(entry->name);
2518 		kfree(entry);
2519 		rv = -ENOMEM;
2520 	} else {
2521 		mutex_lock(&smi->proc_entry_lock);
2522 		/* Stick it on the list. */
2523 		entry->next = smi->proc_entries;
2524 		smi->proc_entries = entry;
2525 		mutex_unlock(&smi->proc_entry_lock);
2526 	}
2527 
2528 	return rv;
2529 }
2530 EXPORT_SYMBOL(ipmi_smi_add_proc_entry);
2531 
2532 static int add_proc_entries(ipmi_smi_t smi, int num)
2533 {
2534 	int rv = 0;
2535 
2536 	sprintf(smi->proc_dir_name, "%d", num);
2537 	smi->proc_dir = proc_mkdir(smi->proc_dir_name, proc_ipmi_root);
2538 	if (!smi->proc_dir)
2539 		rv = -ENOMEM;
2540 
2541 	if (rv == 0)
2542 		rv = ipmi_smi_add_proc_entry(smi, "stats",
2543 					     &smi_stats_proc_ops,
2544 					     smi);
2545 
2546 	if (rv == 0)
2547 		rv = ipmi_smi_add_proc_entry(smi, "ipmb",
2548 					     &smi_ipmb_proc_ops,
2549 					     smi);
2550 
2551 	if (rv == 0)
2552 		rv = ipmi_smi_add_proc_entry(smi, "version",
2553 					     &smi_version_proc_ops,
2554 					     smi);
2555 
2556 	return rv;
2557 }
2558 
2559 static void remove_proc_entries(ipmi_smi_t smi)
2560 {
2561 	struct ipmi_proc_entry *entry;
2562 
2563 	mutex_lock(&smi->proc_entry_lock);
2564 	while (smi->proc_entries) {
2565 		entry = smi->proc_entries;
2566 		smi->proc_entries = entry->next;
2567 
2568 		remove_proc_entry(entry->name, smi->proc_dir);
2569 		kfree(entry->name);
2570 		kfree(entry);
2571 	}
2572 	mutex_unlock(&smi->proc_entry_lock);
2573 	remove_proc_entry(smi->proc_dir_name, proc_ipmi_root);
2574 }
2575 #endif /* CONFIG_IPMI_PROC_INTERFACE */
2576 
2577 static ssize_t device_id_show(struct device *dev,
2578 			      struct device_attribute *attr,
2579 			      char *buf)
2580 {
2581 	struct bmc_device *bmc = to_bmc_device(dev);
2582 	struct ipmi_device_id id;
2583 	int rv;
2584 
2585 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2586 	if (rv)
2587 		return rv;
2588 
2589 	return snprintf(buf, 10, "%u\n", id.device_id);
2590 }
2591 static DEVICE_ATTR_RO(device_id);
2592 
2593 static ssize_t provides_device_sdrs_show(struct device *dev,
2594 					 struct device_attribute *attr,
2595 					 char *buf)
2596 {
2597 	struct bmc_device *bmc = to_bmc_device(dev);
2598 	struct ipmi_device_id id;
2599 	int rv;
2600 
2601 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2602 	if (rv)
2603 		return rv;
2604 
2605 	return snprintf(buf, 10, "%u\n", (id.device_revision & 0x80) >> 7);
2606 }
2607 static DEVICE_ATTR_RO(provides_device_sdrs);
2608 
2609 static ssize_t revision_show(struct device *dev, struct device_attribute *attr,
2610 			     char *buf)
2611 {
2612 	struct bmc_device *bmc = to_bmc_device(dev);
2613 	struct ipmi_device_id id;
2614 	int rv;
2615 
2616 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2617 	if (rv)
2618 		return rv;
2619 
2620 	return snprintf(buf, 20, "%u\n", id.device_revision & 0x0F);
2621 }
2622 static DEVICE_ATTR_RO(revision);
2623 
2624 static ssize_t firmware_revision_show(struct device *dev,
2625 				      struct device_attribute *attr,
2626 				      char *buf)
2627 {
2628 	struct bmc_device *bmc = to_bmc_device(dev);
2629 	struct ipmi_device_id id;
2630 	int rv;
2631 
2632 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2633 	if (rv)
2634 		return rv;
2635 
2636 	return snprintf(buf, 20, "%u.%x\n", id.firmware_revision_1,
2637 			id.firmware_revision_2);
2638 }
2639 static DEVICE_ATTR_RO(firmware_revision);
2640 
2641 static ssize_t ipmi_version_show(struct device *dev,
2642 				 struct device_attribute *attr,
2643 				 char *buf)
2644 {
2645 	struct bmc_device *bmc = to_bmc_device(dev);
2646 	struct ipmi_device_id id;
2647 	int rv;
2648 
2649 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2650 	if (rv)
2651 		return rv;
2652 
2653 	return snprintf(buf, 20, "%u.%u\n",
2654 			ipmi_version_major(&id),
2655 			ipmi_version_minor(&id));
2656 }
2657 static DEVICE_ATTR_RO(ipmi_version);
2658 
2659 static ssize_t add_dev_support_show(struct device *dev,
2660 				    struct device_attribute *attr,
2661 				    char *buf)
2662 {
2663 	struct bmc_device *bmc = to_bmc_device(dev);
2664 	struct ipmi_device_id id;
2665 	int rv;
2666 
2667 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2668 	if (rv)
2669 		return rv;
2670 
2671 	return snprintf(buf, 10, "0x%02x\n", id.additional_device_support);
2672 }
2673 static DEVICE_ATTR(additional_device_support, S_IRUGO, add_dev_support_show,
2674 		   NULL);
2675 
2676 static ssize_t manufacturer_id_show(struct device *dev,
2677 				    struct device_attribute *attr,
2678 				    char *buf)
2679 {
2680 	struct bmc_device *bmc = to_bmc_device(dev);
2681 	struct ipmi_device_id id;
2682 	int rv;
2683 
2684 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2685 	if (rv)
2686 		return rv;
2687 
2688 	return snprintf(buf, 20, "0x%6.6x\n", id.manufacturer_id);
2689 }
2690 static DEVICE_ATTR_RO(manufacturer_id);
2691 
2692 static ssize_t product_id_show(struct device *dev,
2693 			       struct device_attribute *attr,
2694 			       char *buf)
2695 {
2696 	struct bmc_device *bmc = to_bmc_device(dev);
2697 	struct ipmi_device_id id;
2698 	int rv;
2699 
2700 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2701 	if (rv)
2702 		return rv;
2703 
2704 	return snprintf(buf, 10, "0x%4.4x\n", id.product_id);
2705 }
2706 static DEVICE_ATTR_RO(product_id);
2707 
2708 static ssize_t aux_firmware_rev_show(struct device *dev,
2709 				     struct device_attribute *attr,
2710 				     char *buf)
2711 {
2712 	struct bmc_device *bmc = to_bmc_device(dev);
2713 	struct ipmi_device_id id;
2714 	int rv;
2715 
2716 	rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2717 	if (rv)
2718 		return rv;
2719 
2720 	return snprintf(buf, 21, "0x%02x 0x%02x 0x%02x 0x%02x\n",
2721 			id.aux_firmware_revision[3],
2722 			id.aux_firmware_revision[2],
2723 			id.aux_firmware_revision[1],
2724 			id.aux_firmware_revision[0]);
2725 }
2726 static DEVICE_ATTR(aux_firmware_revision, S_IRUGO, aux_firmware_rev_show, NULL);
2727 
2728 static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
2729 			 char *buf)
2730 {
2731 	struct bmc_device *bmc = to_bmc_device(dev);
2732 	bool guid_set;
2733 	guid_t guid;
2734 	int rv;
2735 
2736 	rv = bmc_get_device_id(NULL, bmc, NULL, &guid_set, &guid);
2737 	if (rv)
2738 		return rv;
2739 	if (!guid_set)
2740 		return -ENOENT;
2741 
2742 	return snprintf(buf, 38, "%pUl\n", guid.b);
2743 }
2744 static DEVICE_ATTR_RO(guid);
2745 
2746 static struct attribute *bmc_dev_attrs[] = {
2747 	&dev_attr_device_id.attr,
2748 	&dev_attr_provides_device_sdrs.attr,
2749 	&dev_attr_revision.attr,
2750 	&dev_attr_firmware_revision.attr,
2751 	&dev_attr_ipmi_version.attr,
2752 	&dev_attr_additional_device_support.attr,
2753 	&dev_attr_manufacturer_id.attr,
2754 	&dev_attr_product_id.attr,
2755 	&dev_attr_aux_firmware_revision.attr,
2756 	&dev_attr_guid.attr,
2757 	NULL
2758 };
2759 
2760 static umode_t bmc_dev_attr_is_visible(struct kobject *kobj,
2761 				       struct attribute *attr, int idx)
2762 {
2763 	struct device *dev = kobj_to_dev(kobj);
2764 	struct bmc_device *bmc = to_bmc_device(dev);
2765 	umode_t mode = attr->mode;
2766 	int rv;
2767 
2768 	if (attr == &dev_attr_aux_firmware_revision.attr) {
2769 		struct ipmi_device_id id;
2770 
2771 		rv = bmc_get_device_id(NULL, bmc, &id, NULL, NULL);
2772 		return (!rv && id.aux_firmware_revision_set) ? mode : 0;
2773 	}
2774 	if (attr == &dev_attr_guid.attr) {
2775 		bool guid_set;
2776 
2777 		rv = bmc_get_device_id(NULL, bmc, NULL, &guid_set, NULL);
2778 		return (!rv && guid_set) ? mode : 0;
2779 	}
2780 	return mode;
2781 }
2782 
2783 static const struct attribute_group bmc_dev_attr_group = {
2784 	.attrs		= bmc_dev_attrs,
2785 	.is_visible	= bmc_dev_attr_is_visible,
2786 };
2787 
2788 static const struct attribute_group *bmc_dev_attr_groups[] = {
2789 	&bmc_dev_attr_group,
2790 	NULL
2791 };
2792 
2793 static const struct device_type bmc_device_type = {
2794 	.groups		= bmc_dev_attr_groups,
2795 };
2796 
2797 static int __find_bmc_guid(struct device *dev, void *data)
2798 {
2799 	guid_t *guid = data;
2800 	struct bmc_device *bmc;
2801 	int rv;
2802 
2803 	if (dev->type != &bmc_device_type)
2804 		return 0;
2805 
2806 	bmc = to_bmc_device(dev);
2807 	rv = bmc->dyn_guid_set && guid_equal(&bmc->guid, guid);
2808 	if (rv)
2809 		rv = kref_get_unless_zero(&bmc->usecount);
2810 	return rv;
2811 }
2812 
2813 /*
2814  * Returns with the bmc's usecount incremented, if it is non-NULL.
2815  */
2816 static struct bmc_device *ipmi_find_bmc_guid(struct device_driver *drv,
2817 					     guid_t *guid)
2818 {
2819 	struct device *dev;
2820 	struct bmc_device *bmc = NULL;
2821 
2822 	dev = driver_find_device(drv, NULL, guid, __find_bmc_guid);
2823 	if (dev) {
2824 		bmc = to_bmc_device(dev);
2825 		put_device(dev);
2826 	}
2827 	return bmc;
2828 }
2829 
2830 struct prod_dev_id {
2831 	unsigned int  product_id;
2832 	unsigned char device_id;
2833 };
2834 
2835 static int __find_bmc_prod_dev_id(struct device *dev, void *data)
2836 {
2837 	struct prod_dev_id *cid = data;
2838 	struct bmc_device *bmc;
2839 	int rv;
2840 
2841 	if (dev->type != &bmc_device_type)
2842 		return 0;
2843 
2844 	bmc = to_bmc_device(dev);
2845 	rv = (bmc->id.product_id == cid->product_id
2846 	      && bmc->id.device_id == cid->device_id);
2847 	if (rv)
2848 		rv = kref_get_unless_zero(&bmc->usecount);
2849 	return rv;
2850 }
2851 
2852 /*
2853  * Returns with the bmc's usecount incremented, if it is non-NULL.
2854  */
2855 static struct bmc_device *ipmi_find_bmc_prod_dev_id(
2856 	struct device_driver *drv,
2857 	unsigned int product_id, unsigned char device_id)
2858 {
2859 	struct prod_dev_id id = {
2860 		.product_id = product_id,
2861 		.device_id = device_id,
2862 	};
2863 	struct device *dev;
2864 	struct bmc_device *bmc = NULL;
2865 
2866 	dev = driver_find_device(drv, NULL, &id, __find_bmc_prod_dev_id);
2867 	if (dev) {
2868 		bmc = to_bmc_device(dev);
2869 		put_device(dev);
2870 	}
2871 	return bmc;
2872 }
2873 
2874 static DEFINE_IDA(ipmi_bmc_ida);
2875 
2876 static void
2877 release_bmc_device(struct device *dev)
2878 {
2879 	kfree(to_bmc_device(dev));
2880 }
2881 
2882 static void cleanup_bmc_work(struct work_struct *work)
2883 {
2884 	struct bmc_device *bmc = container_of(work, struct bmc_device,
2885 					      remove_work);
2886 	int id = bmc->pdev.id; /* Unregister overwrites id */
2887 
2888 	platform_device_unregister(&bmc->pdev);
2889 	ida_simple_remove(&ipmi_bmc_ida, id);
2890 }
2891 
2892 static void
2893 cleanup_bmc_device(struct kref *ref)
2894 {
2895 	struct bmc_device *bmc = container_of(ref, struct bmc_device, usecount);
2896 
2897 	/*
2898 	 * Remove the platform device in a work queue to avoid issues
2899 	 * with removing the device attributes while reading a device
2900 	 * attribute.
2901 	 */
2902 	schedule_work(&bmc->remove_work);
2903 }
2904 
2905 /*
2906  * Must be called with intf->bmc_reg_mutex held.
2907  */
2908 static void __ipmi_bmc_unregister(ipmi_smi_t intf)
2909 {
2910 	struct bmc_device *bmc = intf->bmc;
2911 
2912 	if (!intf->bmc_registered)
2913 		return;
2914 
2915 	sysfs_remove_link(&intf->si_dev->kobj, "bmc");
2916 	sysfs_remove_link(&bmc->pdev.dev.kobj, intf->my_dev_name);
2917 	kfree(intf->my_dev_name);
2918 	intf->my_dev_name = NULL;
2919 
2920 	mutex_lock(&bmc->dyn_mutex);
2921 	list_del(&intf->bmc_link);
2922 	mutex_unlock(&bmc->dyn_mutex);
2923 	intf->bmc = &intf->tmp_bmc;
2924 	kref_put(&bmc->usecount, cleanup_bmc_device);
2925 	intf->bmc_registered = false;
2926 }
2927 
2928 static void ipmi_bmc_unregister(ipmi_smi_t intf)
2929 {
2930 	mutex_lock(&intf->bmc_reg_mutex);
2931 	__ipmi_bmc_unregister(intf);
2932 	mutex_unlock(&intf->bmc_reg_mutex);
2933 }
2934 
2935 /*
2936  * Must be called with intf->bmc_reg_mutex held.
2937  */
2938 static int __ipmi_bmc_register(ipmi_smi_t intf,
2939 			       struct ipmi_device_id *id,
2940 			       bool guid_set, guid_t *guid, int intf_num)
2941 {
2942 	int               rv;
2943 	struct bmc_device *bmc;
2944 	struct bmc_device *old_bmc;
2945 
2946 	/*
2947 	 * platform_device_register() can cause bmc_reg_mutex to
2948 	 * be claimed because of the is_visible functions of
2949 	 * the attributes.  Eliminate possible recursion and
2950 	 * release the lock.
2951 	 */
2952 	intf->in_bmc_register = true;
2953 	mutex_unlock(&intf->bmc_reg_mutex);
2954 
2955 	/*
2956 	 * Try to find if there is an bmc_device struct
2957 	 * representing the interfaced BMC already
2958 	 */
2959 	mutex_lock(&ipmidriver_mutex);
2960 	if (guid_set)
2961 		old_bmc = ipmi_find_bmc_guid(&ipmidriver.driver, guid);
2962 	else
2963 		old_bmc = ipmi_find_bmc_prod_dev_id(&ipmidriver.driver,
2964 						    id->product_id,
2965 						    id->device_id);
2966 
2967 	/*
2968 	 * If there is already an bmc_device, free the new one,
2969 	 * otherwise register the new BMC device
2970 	 */
2971 	if (old_bmc) {
2972 		bmc = old_bmc;
2973 		/*
2974 		 * Note: old_bmc already has usecount incremented by
2975 		 * the BMC find functions.
2976 		 */
2977 		intf->bmc = old_bmc;
2978 		mutex_lock(&bmc->dyn_mutex);
2979 		list_add_tail(&intf->bmc_link, &bmc->intfs);
2980 		mutex_unlock(&bmc->dyn_mutex);
2981 
2982 		dev_info(intf->si_dev,
2983 			 "ipmi: interfacing existing BMC (man_id: 0x%6.6x,"
2984 			 " prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n",
2985 			 bmc->id.manufacturer_id,
2986 			 bmc->id.product_id,
2987 			 bmc->id.device_id);
2988 	} else {
2989 		bmc = kzalloc(sizeof(*bmc), GFP_KERNEL);
2990 		if (!bmc) {
2991 			rv = -ENOMEM;
2992 			goto out;
2993 		}
2994 		INIT_LIST_HEAD(&bmc->intfs);
2995 		mutex_init(&bmc->dyn_mutex);
2996 		INIT_WORK(&bmc->remove_work, cleanup_bmc_work);
2997 
2998 		bmc->id = *id;
2999 		bmc->dyn_id_set = 1;
3000 		bmc->dyn_guid_set = guid_set;
3001 		bmc->guid = *guid;
3002 		bmc->dyn_id_expiry = jiffies + IPMI_DYN_DEV_ID_EXPIRY;
3003 
3004 		bmc->pdev.name = "ipmi_bmc";
3005 
3006 		rv = ida_simple_get(&ipmi_bmc_ida, 0, 0, GFP_KERNEL);
3007 		if (rv < 0)
3008 			goto out;
3009 		bmc->pdev.dev.driver = &ipmidriver.driver;
3010 		bmc->pdev.id = rv;
3011 		bmc->pdev.dev.release = release_bmc_device;
3012 		bmc->pdev.dev.type = &bmc_device_type;
3013 		kref_init(&bmc->usecount);
3014 
3015 		intf->bmc = bmc;
3016 		mutex_lock(&bmc->dyn_mutex);
3017 		list_add_tail(&intf->bmc_link, &bmc->intfs);
3018 		mutex_unlock(&bmc->dyn_mutex);
3019 
3020 		rv = platform_device_register(&bmc->pdev);
3021 		if (rv) {
3022 			dev_err(intf->si_dev,
3023 				PFX " Unable to register bmc device: %d\n",
3024 				rv);
3025 			goto out_list_del;
3026 		}
3027 
3028 		dev_info(intf->si_dev,
3029 			 "Found new BMC (man_id: 0x%6.6x, prod_id: 0x%4.4x, dev_id: 0x%2.2x)\n",
3030 			 bmc->id.manufacturer_id,
3031 			 bmc->id.product_id,
3032 			 bmc->id.device_id);
3033 	}
3034 
3035 	/*
3036 	 * create symlink from system interface device to bmc device
3037 	 * and back.
3038 	 */
3039 	rv = sysfs_create_link(&intf->si_dev->kobj, &bmc->pdev.dev.kobj, "bmc");
3040 	if (rv) {
3041 		dev_err(intf->si_dev,
3042 			PFX "Unable to create bmc symlink: %d\n", rv);
3043 		goto out_put_bmc;
3044 	}
3045 
3046 	if (intf_num == -1)
3047 		intf_num = intf->intf_num;
3048 	intf->my_dev_name = kasprintf(GFP_KERNEL, "ipmi%d", intf_num);
3049 	if (!intf->my_dev_name) {
3050 		rv = -ENOMEM;
3051 		dev_err(intf->si_dev,
3052 			PFX "Unable to allocate link from BMC: %d\n", rv);
3053 		goto out_unlink1;
3054 	}
3055 
3056 	rv = sysfs_create_link(&bmc->pdev.dev.kobj, &intf->si_dev->kobj,
3057 			       intf->my_dev_name);
3058 	if (rv) {
3059 		kfree(intf->my_dev_name);
3060 		intf->my_dev_name = NULL;
3061 		dev_err(intf->si_dev,
3062 			PFX "Unable to create symlink to bmc: %d\n", rv);
3063 		goto out_free_my_dev_name;
3064 	}
3065 
3066 	intf->bmc_registered = true;
3067 
3068 out:
3069 	mutex_unlock(&ipmidriver_mutex);
3070 	mutex_lock(&intf->bmc_reg_mutex);
3071 	intf->in_bmc_register = false;
3072 	return rv;
3073 
3074 
3075 out_free_my_dev_name:
3076 	kfree(intf->my_dev_name);
3077 	intf->my_dev_name = NULL;
3078 
3079 out_unlink1:
3080 	sysfs_remove_link(&intf->si_dev->kobj, "bmc");
3081 
3082 out_put_bmc:
3083 	mutex_lock(&bmc->dyn_mutex);
3084 	list_del(&intf->bmc_link);
3085 	mutex_unlock(&bmc->dyn_mutex);
3086 	intf->bmc = &intf->tmp_bmc;
3087 	kref_put(&bmc->usecount, cleanup_bmc_device);
3088 	goto out;
3089 
3090 out_list_del:
3091 	mutex_lock(&bmc->dyn_mutex);
3092 	list_del(&intf->bmc_link);
3093 	mutex_unlock(&bmc->dyn_mutex);
3094 	intf->bmc = &intf->tmp_bmc;
3095 	put_device(&bmc->pdev.dev);
3096 	goto out;
3097 }
3098 
3099 static int
3100 send_guid_cmd(ipmi_smi_t intf, int chan)
3101 {
3102 	struct kernel_ipmi_msg            msg;
3103 	struct ipmi_system_interface_addr si;
3104 
3105 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
3106 	si.channel = IPMI_BMC_CHANNEL;
3107 	si.lun = 0;
3108 
3109 	msg.netfn = IPMI_NETFN_APP_REQUEST;
3110 	msg.cmd = IPMI_GET_DEVICE_GUID_CMD;
3111 	msg.data = NULL;
3112 	msg.data_len = 0;
3113 	return i_ipmi_request(NULL,
3114 			      intf,
3115 			      (struct ipmi_addr *) &si,
3116 			      0,
3117 			      &msg,
3118 			      intf,
3119 			      NULL,
3120 			      NULL,
3121 			      0,
3122 			      intf->addrinfo[0].address,
3123 			      intf->addrinfo[0].lun,
3124 			      -1, 0);
3125 }
3126 
3127 static void guid_handler(ipmi_smi_t intf, struct ipmi_recv_msg *msg)
3128 {
3129 	struct bmc_device *bmc = intf->bmc;
3130 
3131 	if ((msg->addr.addr_type != IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
3132 	    || (msg->msg.netfn != IPMI_NETFN_APP_RESPONSE)
3133 	    || (msg->msg.cmd != IPMI_GET_DEVICE_GUID_CMD))
3134 		/* Not for me */
3135 		return;
3136 
3137 	if (msg->msg.data[0] != 0) {
3138 		/* Error from getting the GUID, the BMC doesn't have one. */
3139 		bmc->dyn_guid_set = 0;
3140 		goto out;
3141 	}
3142 
3143 	if (msg->msg.data_len < 17) {
3144 		bmc->dyn_guid_set = 0;
3145 		dev_warn(intf->si_dev,
3146 			 PFX "The GUID response from the BMC was too short, it was %d but should have been 17.  Assuming GUID is not available.\n",
3147 			 msg->msg.data_len);
3148 		goto out;
3149 	}
3150 
3151 	memcpy(bmc->fetch_guid.b, msg->msg.data + 1, 16);
3152 	/*
3153 	 * Make sure the guid data is available before setting
3154 	 * dyn_guid_set.
3155 	 */
3156 	smp_wmb();
3157 	bmc->dyn_guid_set = 1;
3158  out:
3159 	wake_up(&intf->waitq);
3160 }
3161 
3162 static void __get_guid(ipmi_smi_t intf)
3163 {
3164 	int rv;
3165 	struct bmc_device *bmc = intf->bmc;
3166 
3167 	bmc->dyn_guid_set = 2;
3168 	intf->null_user_handler = guid_handler;
3169 	rv = send_guid_cmd(intf, 0);
3170 	if (rv)
3171 		/* Send failed, no GUID available. */
3172 		bmc->dyn_guid_set = 0;
3173 
3174 	wait_event(intf->waitq, bmc->dyn_guid_set != 2);
3175 
3176 	/* dyn_guid_set makes the guid data available. */
3177 	smp_rmb();
3178 
3179 	intf->null_user_handler = NULL;
3180 }
3181 
3182 static int
3183 send_channel_info_cmd(ipmi_smi_t intf, int chan)
3184 {
3185 	struct kernel_ipmi_msg            msg;
3186 	unsigned char                     data[1];
3187 	struct ipmi_system_interface_addr si;
3188 
3189 	si.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
3190 	si.channel = IPMI_BMC_CHANNEL;
3191 	si.lun = 0;
3192 
3193 	msg.netfn = IPMI_NETFN_APP_REQUEST;
3194 	msg.cmd = IPMI_GET_CHANNEL_INFO_CMD;
3195 	msg.data = data;
3196 	msg.data_len = 1;
3197 	data[0] = chan;
3198 	return i_ipmi_request(NULL,
3199 			      intf,
3200 			      (struct ipmi_addr *) &si,
3201 			      0,
3202 			      &msg,
3203 			      intf,
3204 			      NULL,
3205 			      NULL,
3206 			      0,
3207 			      intf->addrinfo[0].address,
3208 			      intf->addrinfo[0].lun,
3209 			      -1, 0);
3210 }
3211 
3212 static void
3213 channel_handler(ipmi_smi_t intf, struct ipmi_recv_msg *msg)
3214 {
3215 	int rv = 0;
3216 	int ch;
3217 	unsigned int set = intf->curr_working_cset;
3218 	struct ipmi_channel *chans;
3219 
3220 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
3221 	    && (msg->msg.netfn == IPMI_NETFN_APP_RESPONSE)
3222 	    && (msg->msg.cmd == IPMI_GET_CHANNEL_INFO_CMD)) {
3223 		/* It's the one we want */
3224 		if (msg->msg.data[0] != 0) {
3225 			/* Got an error from the channel, just go on. */
3226 
3227 			if (msg->msg.data[0] == IPMI_INVALID_COMMAND_ERR) {
3228 				/*
3229 				 * If the MC does not support this
3230 				 * command, that is legal.  We just
3231 				 * assume it has one IPMB at channel
3232 				 * zero.
3233 				 */
3234 				intf->wchannels[set].c[0].medium
3235 					= IPMI_CHANNEL_MEDIUM_IPMB;
3236 				intf->wchannels[set].c[0].protocol
3237 					= IPMI_CHANNEL_PROTOCOL_IPMB;
3238 
3239 				intf->channel_list = intf->wchannels + set;
3240 				intf->channels_ready = true;
3241 				wake_up(&intf->waitq);
3242 				goto out;
3243 			}
3244 			goto next_channel;
3245 		}
3246 		if (msg->msg.data_len < 4) {
3247 			/* Message not big enough, just go on. */
3248 			goto next_channel;
3249 		}
3250 		ch = intf->curr_channel;
3251 		chans = intf->wchannels[set].c;
3252 		chans[ch].medium = msg->msg.data[2] & 0x7f;
3253 		chans[ch].protocol = msg->msg.data[3] & 0x1f;
3254 
3255  next_channel:
3256 		intf->curr_channel++;
3257 		if (intf->curr_channel >= IPMI_MAX_CHANNELS) {
3258 			intf->channel_list = intf->wchannels + set;
3259 			intf->channels_ready = true;
3260 			wake_up(&intf->waitq);
3261 		} else {
3262 			intf->channel_list = intf->wchannels + set;
3263 			intf->channels_ready = true;
3264 			rv = send_channel_info_cmd(intf, intf->curr_channel);
3265 		}
3266 
3267 		if (rv) {
3268 			/* Got an error somehow, just give up. */
3269 			dev_warn(intf->si_dev,
3270 				 PFX "Error sending channel information for channel %d: %d\n",
3271 				 intf->curr_channel, rv);
3272 
3273 			intf->channel_list = intf->wchannels + set;
3274 			intf->channels_ready = true;
3275 			wake_up(&intf->waitq);
3276 		}
3277 	}
3278  out:
3279 	return;
3280 }
3281 
3282 /*
3283  * Must be holding intf->bmc_reg_mutex to call this.
3284  */
3285 static int __scan_channels(ipmi_smi_t intf, struct ipmi_device_id *id)
3286 {
3287 	int rv;
3288 
3289 	if (ipmi_version_major(id) > 1
3290 			|| (ipmi_version_major(id) == 1
3291 			    && ipmi_version_minor(id) >= 5)) {
3292 		unsigned int set;
3293 
3294 		/*
3295 		 * Start scanning the channels to see what is
3296 		 * available.
3297 		 */
3298 		set = !intf->curr_working_cset;
3299 		intf->curr_working_cset = set;
3300 		memset(&intf->wchannels[set], 0,
3301 		       sizeof(struct ipmi_channel_set));
3302 
3303 		intf->null_user_handler = channel_handler;
3304 		intf->curr_channel = 0;
3305 		rv = send_channel_info_cmd(intf, 0);
3306 		if (rv) {
3307 			dev_warn(intf->si_dev,
3308 				 "Error sending channel information for channel 0, %d\n",
3309 				 rv);
3310 			return -EIO;
3311 		}
3312 
3313 		/* Wait for the channel info to be read. */
3314 		wait_event(intf->waitq, intf->channels_ready);
3315 		intf->null_user_handler = NULL;
3316 	} else {
3317 		unsigned int set = intf->curr_working_cset;
3318 
3319 		/* Assume a single IPMB channel at zero. */
3320 		intf->wchannels[set].c[0].medium = IPMI_CHANNEL_MEDIUM_IPMB;
3321 		intf->wchannels[set].c[0].protocol = IPMI_CHANNEL_PROTOCOL_IPMB;
3322 		intf->channel_list = intf->wchannels + set;
3323 		intf->channels_ready = true;
3324 	}
3325 
3326 	return 0;
3327 }
3328 
3329 static void ipmi_poll(ipmi_smi_t intf)
3330 {
3331 	if (intf->handlers->poll)
3332 		intf->handlers->poll(intf->send_info);
3333 	/* In case something came in */
3334 	handle_new_recv_msgs(intf);
3335 }
3336 
3337 void ipmi_poll_interface(ipmi_user_t user)
3338 {
3339 	ipmi_poll(user->intf);
3340 }
3341 EXPORT_SYMBOL(ipmi_poll_interface);
3342 
3343 static void redo_bmc_reg(struct work_struct *work)
3344 {
3345 	ipmi_smi_t intf = container_of(work, struct ipmi_smi, bmc_reg_work);
3346 
3347 	if (!intf->in_shutdown)
3348 		bmc_get_device_id(intf, NULL, NULL, NULL, NULL);
3349 
3350 	kref_put(&intf->refcount, intf_free);
3351 }
3352 
3353 int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
3354 		      void		       *send_info,
3355 		      struct device            *si_dev,
3356 		      unsigned char            slave_addr)
3357 {
3358 	int              i, j;
3359 	int              rv;
3360 	ipmi_smi_t       intf;
3361 	ipmi_smi_t       tintf;
3362 	struct list_head *link;
3363 	struct ipmi_device_id id;
3364 
3365 	/*
3366 	 * Make sure the driver is actually initialized, this handles
3367 	 * problems with initialization order.
3368 	 */
3369 	if (!initialized) {
3370 		rv = ipmi_init_msghandler();
3371 		if (rv)
3372 			return rv;
3373 		/*
3374 		 * The init code doesn't return an error if it was turned
3375 		 * off, but it won't initialize.  Check that.
3376 		 */
3377 		if (!initialized)
3378 			return -ENODEV;
3379 	}
3380 
3381 	intf = kzalloc(sizeof(*intf), GFP_KERNEL);
3382 	if (!intf)
3383 		return -ENOMEM;
3384 
3385 	intf->bmc = &intf->tmp_bmc;
3386 	INIT_LIST_HEAD(&intf->bmc->intfs);
3387 	mutex_init(&intf->bmc->dyn_mutex);
3388 	INIT_LIST_HEAD(&intf->bmc_link);
3389 	mutex_init(&intf->bmc_reg_mutex);
3390 	intf->intf_num = -1; /* Mark it invalid for now. */
3391 	kref_init(&intf->refcount);
3392 	INIT_WORK(&intf->bmc_reg_work, redo_bmc_reg);
3393 	intf->si_dev = si_dev;
3394 	for (j = 0; j < IPMI_MAX_CHANNELS; j++) {
3395 		intf->addrinfo[j].address = IPMI_BMC_SLAVE_ADDR;
3396 		intf->addrinfo[j].lun = 2;
3397 	}
3398 	if (slave_addr != 0)
3399 		intf->addrinfo[0].address = slave_addr;
3400 	INIT_LIST_HEAD(&intf->users);
3401 	intf->handlers = handlers;
3402 	intf->send_info = send_info;
3403 	spin_lock_init(&intf->seq_lock);
3404 	for (j = 0; j < IPMI_IPMB_NUM_SEQ; j++) {
3405 		intf->seq_table[j].inuse = 0;
3406 		intf->seq_table[j].seqid = 0;
3407 	}
3408 	intf->curr_seq = 0;
3409 #ifdef CONFIG_IPMI_PROC_INTERFACE
3410 	mutex_init(&intf->proc_entry_lock);
3411 #endif
3412 	spin_lock_init(&intf->waiting_rcv_msgs_lock);
3413 	INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
3414 	tasklet_init(&intf->recv_tasklet,
3415 		     smi_recv_tasklet,
3416 		     (unsigned long) intf);
3417 	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 0);
3418 	spin_lock_init(&intf->xmit_msgs_lock);
3419 	INIT_LIST_HEAD(&intf->xmit_msgs);
3420 	INIT_LIST_HEAD(&intf->hp_xmit_msgs);
3421 	spin_lock_init(&intf->events_lock);
3422 	atomic_set(&intf->event_waiters, 0);
3423 	intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
3424 	INIT_LIST_HEAD(&intf->waiting_events);
3425 	intf->waiting_events_count = 0;
3426 	mutex_init(&intf->cmd_rcvrs_mutex);
3427 	spin_lock_init(&intf->maintenance_mode_lock);
3428 	INIT_LIST_HEAD(&intf->cmd_rcvrs);
3429 	init_waitqueue_head(&intf->waitq);
3430 	for (i = 0; i < IPMI_NUM_STATS; i++)
3431 		atomic_set(&intf->stats[i], 0);
3432 
3433 #ifdef CONFIG_IPMI_PROC_INTERFACE
3434 	intf->proc_dir = NULL;
3435 #endif
3436 
3437 	mutex_lock(&smi_watchers_mutex);
3438 	mutex_lock(&ipmi_interfaces_mutex);
3439 	/* Look for a hole in the numbers. */
3440 	i = 0;
3441 	link = &ipmi_interfaces;
3442 	list_for_each_entry_rcu(tintf, &ipmi_interfaces, link) {
3443 		if (tintf->intf_num != i) {
3444 			link = &tintf->link;
3445 			break;
3446 		}
3447 		i++;
3448 	}
3449 	/* Add the new interface in numeric order. */
3450 	if (i == 0)
3451 		list_add_rcu(&intf->link, &ipmi_interfaces);
3452 	else
3453 		list_add_tail_rcu(&intf->link, link);
3454 
3455 	rv = handlers->start_processing(send_info, intf);
3456 	if (rv)
3457 		goto out;
3458 
3459 	rv = __bmc_get_device_id(intf, NULL, &id, NULL, NULL, i);
3460 	if (rv) {
3461 		dev_err(si_dev, "Unable to get the device id: %d\n", rv);
3462 		goto out;
3463 	}
3464 
3465 	mutex_lock(&intf->bmc_reg_mutex);
3466 	rv = __scan_channels(intf, &id);
3467 	mutex_unlock(&intf->bmc_reg_mutex);
3468 	if (rv)
3469 		goto out;
3470 
3471 #ifdef CONFIG_IPMI_PROC_INTERFACE
3472 	rv = add_proc_entries(intf, i);
3473 #endif
3474 
3475  out:
3476 	if (rv) {
3477 		ipmi_bmc_unregister(intf);
3478 #ifdef CONFIG_IPMI_PROC_INTERFACE
3479 		if (intf->proc_dir)
3480 			remove_proc_entries(intf);
3481 #endif
3482 		intf->handlers = NULL;
3483 		list_del_rcu(&intf->link);
3484 		mutex_unlock(&ipmi_interfaces_mutex);
3485 		mutex_unlock(&smi_watchers_mutex);
3486 		synchronize_rcu();
3487 		kref_put(&intf->refcount, intf_free);
3488 	} else {
3489 		/*
3490 		 * Keep memory order straight for RCU readers.  Make
3491 		 * sure everything else is committed to memory before
3492 		 * setting intf_num to mark the interface valid.
3493 		 */
3494 		smp_wmb();
3495 		intf->intf_num = i;
3496 		mutex_unlock(&ipmi_interfaces_mutex);
3497 		/* After this point the interface is legal to use. */
3498 		call_smi_watchers(i, intf->si_dev);
3499 		mutex_unlock(&smi_watchers_mutex);
3500 	}
3501 
3502 	return rv;
3503 }
3504 EXPORT_SYMBOL(ipmi_register_smi);
3505 
3506 static void deliver_smi_err_response(ipmi_smi_t intf,
3507 				     struct ipmi_smi_msg *msg,
3508 				     unsigned char err)
3509 {
3510 	msg->rsp[0] = msg->data[0] | 4;
3511 	msg->rsp[1] = msg->data[1];
3512 	msg->rsp[2] = err;
3513 	msg->rsp_size = 3;
3514 	/* It's an error, so it will never requeue, no need to check return. */
3515 	handle_one_recv_msg(intf, msg);
3516 }
3517 
3518 static void cleanup_smi_msgs(ipmi_smi_t intf)
3519 {
3520 	int              i;
3521 	struct seq_table *ent;
3522 	struct ipmi_smi_msg *msg;
3523 	struct list_head *entry;
3524 	struct list_head tmplist;
3525 
3526 	/* Clear out our transmit queues and hold the messages. */
3527 	INIT_LIST_HEAD(&tmplist);
3528 	list_splice_tail(&intf->hp_xmit_msgs, &tmplist);
3529 	list_splice_tail(&intf->xmit_msgs, &tmplist);
3530 
3531 	/* Current message first, to preserve order */
3532 	while (intf->curr_msg && !list_empty(&intf->waiting_rcv_msgs)) {
3533 		/* Wait for the message to clear out. */
3534 		schedule_timeout(1);
3535 	}
3536 
3537 	/* No need for locks, the interface is down. */
3538 
3539 	/*
3540 	 * Return errors for all pending messages in queue and in the
3541 	 * tables waiting for remote responses.
3542 	 */
3543 	while (!list_empty(&tmplist)) {
3544 		entry = tmplist.next;
3545 		list_del(entry);
3546 		msg = list_entry(entry, struct ipmi_smi_msg, link);
3547 		deliver_smi_err_response(intf, msg, IPMI_ERR_UNSPECIFIED);
3548 	}
3549 
3550 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++) {
3551 		ent = &(intf->seq_table[i]);
3552 		if (!ent->inuse)
3553 			continue;
3554 		deliver_err_response(ent->recv_msg, IPMI_ERR_UNSPECIFIED);
3555 	}
3556 }
3557 
3558 int ipmi_unregister_smi(ipmi_smi_t intf)
3559 {
3560 	struct ipmi_smi_watcher *w;
3561 	int intf_num = intf->intf_num;
3562 	ipmi_user_t user;
3563 
3564 	mutex_lock(&smi_watchers_mutex);
3565 	mutex_lock(&ipmi_interfaces_mutex);
3566 	intf->intf_num = -1;
3567 	intf->in_shutdown = true;
3568 	list_del_rcu(&intf->link);
3569 	mutex_unlock(&ipmi_interfaces_mutex);
3570 	synchronize_rcu();
3571 
3572 	cleanup_smi_msgs(intf);
3573 
3574 	/* Clean up the effects of users on the lower-level software. */
3575 	mutex_lock(&ipmi_interfaces_mutex);
3576 	rcu_read_lock();
3577 	list_for_each_entry_rcu(user, &intf->users, link) {
3578 		module_put(intf->handlers->owner);
3579 		if (intf->handlers->dec_usecount)
3580 			intf->handlers->dec_usecount(intf->send_info);
3581 	}
3582 	rcu_read_unlock();
3583 	intf->handlers = NULL;
3584 	mutex_unlock(&ipmi_interfaces_mutex);
3585 
3586 #ifdef CONFIG_IPMI_PROC_INTERFACE
3587 	remove_proc_entries(intf);
3588 #endif
3589 	ipmi_bmc_unregister(intf);
3590 
3591 	/*
3592 	 * Call all the watcher interfaces to tell them that
3593 	 * an interface is gone.
3594 	 */
3595 	list_for_each_entry(w, &smi_watchers, link)
3596 		w->smi_gone(intf_num);
3597 	mutex_unlock(&smi_watchers_mutex);
3598 
3599 	kref_put(&intf->refcount, intf_free);
3600 	return 0;
3601 }
3602 EXPORT_SYMBOL(ipmi_unregister_smi);
3603 
3604 static int handle_ipmb_get_msg_rsp(ipmi_smi_t          intf,
3605 				   struct ipmi_smi_msg *msg)
3606 {
3607 	struct ipmi_ipmb_addr ipmb_addr;
3608 	struct ipmi_recv_msg  *recv_msg;
3609 
3610 	/*
3611 	 * This is 11, not 10, because the response must contain a
3612 	 * completion code.
3613 	 */
3614 	if (msg->rsp_size < 11) {
3615 		/* Message not big enough, just ignore it. */
3616 		ipmi_inc_stat(intf, invalid_ipmb_responses);
3617 		return 0;
3618 	}
3619 
3620 	if (msg->rsp[2] != 0) {
3621 		/* An error getting the response, just ignore it. */
3622 		return 0;
3623 	}
3624 
3625 	ipmb_addr.addr_type = IPMI_IPMB_ADDR_TYPE;
3626 	ipmb_addr.slave_addr = msg->rsp[6];
3627 	ipmb_addr.channel = msg->rsp[3] & 0x0f;
3628 	ipmb_addr.lun = msg->rsp[7] & 3;
3629 
3630 	/*
3631 	 * It's a response from a remote entity.  Look up the sequence
3632 	 * number and handle the response.
3633 	 */
3634 	if (intf_find_seq(intf,
3635 			  msg->rsp[7] >> 2,
3636 			  msg->rsp[3] & 0x0f,
3637 			  msg->rsp[8],
3638 			  (msg->rsp[4] >> 2) & (~1),
3639 			  (struct ipmi_addr *) &(ipmb_addr),
3640 			  &recv_msg)) {
3641 		/*
3642 		 * We were unable to find the sequence number,
3643 		 * so just nuke the message.
3644 		 */
3645 		ipmi_inc_stat(intf, unhandled_ipmb_responses);
3646 		return 0;
3647 	}
3648 
3649 	memcpy(recv_msg->msg_data,
3650 	       &(msg->rsp[9]),
3651 	       msg->rsp_size - 9);
3652 	/*
3653 	 * The other fields matched, so no need to set them, except
3654 	 * for netfn, which needs to be the response that was
3655 	 * returned, not the request value.
3656 	 */
3657 	recv_msg->msg.netfn = msg->rsp[4] >> 2;
3658 	recv_msg->msg.data = recv_msg->msg_data;
3659 	recv_msg->msg.data_len = msg->rsp_size - 10;
3660 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
3661 	ipmi_inc_stat(intf, handled_ipmb_responses);
3662 	deliver_response(recv_msg);
3663 
3664 	return 0;
3665 }
3666 
3667 static int handle_ipmb_get_msg_cmd(ipmi_smi_t          intf,
3668 				   struct ipmi_smi_msg *msg)
3669 {
3670 	struct cmd_rcvr          *rcvr;
3671 	int                      rv = 0;
3672 	unsigned char            netfn;
3673 	unsigned char            cmd;
3674 	unsigned char            chan;
3675 	ipmi_user_t              user = NULL;
3676 	struct ipmi_ipmb_addr    *ipmb_addr;
3677 	struct ipmi_recv_msg     *recv_msg;
3678 
3679 	if (msg->rsp_size < 10) {
3680 		/* Message not big enough, just ignore it. */
3681 		ipmi_inc_stat(intf, invalid_commands);
3682 		return 0;
3683 	}
3684 
3685 	if (msg->rsp[2] != 0) {
3686 		/* An error getting the response, just ignore it. */
3687 		return 0;
3688 	}
3689 
3690 	netfn = msg->rsp[4] >> 2;
3691 	cmd = msg->rsp[8];
3692 	chan = msg->rsp[3] & 0xf;
3693 
3694 	rcu_read_lock();
3695 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
3696 	if (rcvr) {
3697 		user = rcvr->user;
3698 		kref_get(&user->refcount);
3699 	} else
3700 		user = NULL;
3701 	rcu_read_unlock();
3702 
3703 	if (user == NULL) {
3704 		/* We didn't find a user, deliver an error response. */
3705 		ipmi_inc_stat(intf, unhandled_commands);
3706 
3707 		msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
3708 		msg->data[1] = IPMI_SEND_MSG_CMD;
3709 		msg->data[2] = msg->rsp[3];
3710 		msg->data[3] = msg->rsp[6];
3711 		msg->data[4] = ((netfn + 1) << 2) | (msg->rsp[7] & 0x3);
3712 		msg->data[5] = ipmb_checksum(&(msg->data[3]), 2);
3713 		msg->data[6] = intf->addrinfo[msg->rsp[3] & 0xf].address;
3714 		/* rqseq/lun */
3715 		msg->data[7] = (msg->rsp[7] & 0xfc) | (msg->rsp[4] & 0x3);
3716 		msg->data[8] = msg->rsp[8]; /* cmd */
3717 		msg->data[9] = IPMI_INVALID_CMD_COMPLETION_CODE;
3718 		msg->data[10] = ipmb_checksum(&(msg->data[6]), 4);
3719 		msg->data_size = 11;
3720 
3721 #ifdef DEBUG_MSGING
3722 	{
3723 		int m;
3724 		printk("Invalid command:");
3725 		for (m = 0; m < msg->data_size; m++)
3726 			printk(" %2.2x", msg->data[m]);
3727 		printk("\n");
3728 	}
3729 #endif
3730 		rcu_read_lock();
3731 		if (!intf->in_shutdown) {
3732 			smi_send(intf, intf->handlers, msg, 0);
3733 			/*
3734 			 * We used the message, so return the value
3735 			 * that causes it to not be freed or
3736 			 * queued.
3737 			 */
3738 			rv = -1;
3739 		}
3740 		rcu_read_unlock();
3741 	} else {
3742 		/* Deliver the message to the user. */
3743 		ipmi_inc_stat(intf, handled_commands);
3744 
3745 		recv_msg = ipmi_alloc_recv_msg();
3746 		if (!recv_msg) {
3747 			/*
3748 			 * We couldn't allocate memory for the
3749 			 * message, so requeue it for handling
3750 			 * later.
3751 			 */
3752 			rv = 1;
3753 			kref_put(&user->refcount, free_user);
3754 		} else {
3755 			/* Extract the source address from the data. */
3756 			ipmb_addr = (struct ipmi_ipmb_addr *) &recv_msg->addr;
3757 			ipmb_addr->addr_type = IPMI_IPMB_ADDR_TYPE;
3758 			ipmb_addr->slave_addr = msg->rsp[6];
3759 			ipmb_addr->lun = msg->rsp[7] & 3;
3760 			ipmb_addr->channel = msg->rsp[3] & 0xf;
3761 
3762 			/*
3763 			 * Extract the rest of the message information
3764 			 * from the IPMB header.
3765 			 */
3766 			recv_msg->user = user;
3767 			recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
3768 			recv_msg->msgid = msg->rsp[7] >> 2;
3769 			recv_msg->msg.netfn = msg->rsp[4] >> 2;
3770 			recv_msg->msg.cmd = msg->rsp[8];
3771 			recv_msg->msg.data = recv_msg->msg_data;
3772 
3773 			/*
3774 			 * We chop off 10, not 9 bytes because the checksum
3775 			 * at the end also needs to be removed.
3776 			 */
3777 			recv_msg->msg.data_len = msg->rsp_size - 10;
3778 			memcpy(recv_msg->msg_data,
3779 			       &(msg->rsp[9]),
3780 			       msg->rsp_size - 10);
3781 			deliver_response(recv_msg);
3782 		}
3783 	}
3784 
3785 	return rv;
3786 }
3787 
3788 static int handle_lan_get_msg_rsp(ipmi_smi_t          intf,
3789 				  struct ipmi_smi_msg *msg)
3790 {
3791 	struct ipmi_lan_addr  lan_addr;
3792 	struct ipmi_recv_msg  *recv_msg;
3793 
3794 
3795 	/*
3796 	 * This is 13, not 12, because the response must contain a
3797 	 * completion code.
3798 	 */
3799 	if (msg->rsp_size < 13) {
3800 		/* Message not big enough, just ignore it. */
3801 		ipmi_inc_stat(intf, invalid_lan_responses);
3802 		return 0;
3803 	}
3804 
3805 	if (msg->rsp[2] != 0) {
3806 		/* An error getting the response, just ignore it. */
3807 		return 0;
3808 	}
3809 
3810 	lan_addr.addr_type = IPMI_LAN_ADDR_TYPE;
3811 	lan_addr.session_handle = msg->rsp[4];
3812 	lan_addr.remote_SWID = msg->rsp[8];
3813 	lan_addr.local_SWID = msg->rsp[5];
3814 	lan_addr.channel = msg->rsp[3] & 0x0f;
3815 	lan_addr.privilege = msg->rsp[3] >> 4;
3816 	lan_addr.lun = msg->rsp[9] & 3;
3817 
3818 	/*
3819 	 * It's a response from a remote entity.  Look up the sequence
3820 	 * number and handle the response.
3821 	 */
3822 	if (intf_find_seq(intf,
3823 			  msg->rsp[9] >> 2,
3824 			  msg->rsp[3] & 0x0f,
3825 			  msg->rsp[10],
3826 			  (msg->rsp[6] >> 2) & (~1),
3827 			  (struct ipmi_addr *) &(lan_addr),
3828 			  &recv_msg)) {
3829 		/*
3830 		 * We were unable to find the sequence number,
3831 		 * so just nuke the message.
3832 		 */
3833 		ipmi_inc_stat(intf, unhandled_lan_responses);
3834 		return 0;
3835 	}
3836 
3837 	memcpy(recv_msg->msg_data,
3838 	       &(msg->rsp[11]),
3839 	       msg->rsp_size - 11);
3840 	/*
3841 	 * The other fields matched, so no need to set them, except
3842 	 * for netfn, which needs to be the response that was
3843 	 * returned, not the request value.
3844 	 */
3845 	recv_msg->msg.netfn = msg->rsp[6] >> 2;
3846 	recv_msg->msg.data = recv_msg->msg_data;
3847 	recv_msg->msg.data_len = msg->rsp_size - 12;
3848 	recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
3849 	ipmi_inc_stat(intf, handled_lan_responses);
3850 	deliver_response(recv_msg);
3851 
3852 	return 0;
3853 }
3854 
3855 static int handle_lan_get_msg_cmd(ipmi_smi_t          intf,
3856 				  struct ipmi_smi_msg *msg)
3857 {
3858 	struct cmd_rcvr          *rcvr;
3859 	int                      rv = 0;
3860 	unsigned char            netfn;
3861 	unsigned char            cmd;
3862 	unsigned char            chan;
3863 	ipmi_user_t              user = NULL;
3864 	struct ipmi_lan_addr     *lan_addr;
3865 	struct ipmi_recv_msg     *recv_msg;
3866 
3867 	if (msg->rsp_size < 12) {
3868 		/* Message not big enough, just ignore it. */
3869 		ipmi_inc_stat(intf, invalid_commands);
3870 		return 0;
3871 	}
3872 
3873 	if (msg->rsp[2] != 0) {
3874 		/* An error getting the response, just ignore it. */
3875 		return 0;
3876 	}
3877 
3878 	netfn = msg->rsp[6] >> 2;
3879 	cmd = msg->rsp[10];
3880 	chan = msg->rsp[3] & 0xf;
3881 
3882 	rcu_read_lock();
3883 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
3884 	if (rcvr) {
3885 		user = rcvr->user;
3886 		kref_get(&user->refcount);
3887 	} else
3888 		user = NULL;
3889 	rcu_read_unlock();
3890 
3891 	if (user == NULL) {
3892 		/* We didn't find a user, just give up. */
3893 		ipmi_inc_stat(intf, unhandled_commands);
3894 
3895 		/*
3896 		 * Don't do anything with these messages, just allow
3897 		 * them to be freed.
3898 		 */
3899 		rv = 0;
3900 	} else {
3901 		/* Deliver the message to the user. */
3902 		ipmi_inc_stat(intf, handled_commands);
3903 
3904 		recv_msg = ipmi_alloc_recv_msg();
3905 		if (!recv_msg) {
3906 			/*
3907 			 * We couldn't allocate memory for the
3908 			 * message, so requeue it for handling later.
3909 			 */
3910 			rv = 1;
3911 			kref_put(&user->refcount, free_user);
3912 		} else {
3913 			/* Extract the source address from the data. */
3914 			lan_addr = (struct ipmi_lan_addr *) &recv_msg->addr;
3915 			lan_addr->addr_type = IPMI_LAN_ADDR_TYPE;
3916 			lan_addr->session_handle = msg->rsp[4];
3917 			lan_addr->remote_SWID = msg->rsp[8];
3918 			lan_addr->local_SWID = msg->rsp[5];
3919 			lan_addr->lun = msg->rsp[9] & 3;
3920 			lan_addr->channel = msg->rsp[3] & 0xf;
3921 			lan_addr->privilege = msg->rsp[3] >> 4;
3922 
3923 			/*
3924 			 * Extract the rest of the message information
3925 			 * from the IPMB header.
3926 			 */
3927 			recv_msg->user = user;
3928 			recv_msg->recv_type = IPMI_CMD_RECV_TYPE;
3929 			recv_msg->msgid = msg->rsp[9] >> 2;
3930 			recv_msg->msg.netfn = msg->rsp[6] >> 2;
3931 			recv_msg->msg.cmd = msg->rsp[10];
3932 			recv_msg->msg.data = recv_msg->msg_data;
3933 
3934 			/*
3935 			 * We chop off 12, not 11 bytes because the checksum
3936 			 * at the end also needs to be removed.
3937 			 */
3938 			recv_msg->msg.data_len = msg->rsp_size - 12;
3939 			memcpy(recv_msg->msg_data,
3940 			       &(msg->rsp[11]),
3941 			       msg->rsp_size - 12);
3942 			deliver_response(recv_msg);
3943 		}
3944 	}
3945 
3946 	return rv;
3947 }
3948 
3949 /*
3950  * This routine will handle "Get Message" command responses with
3951  * channels that use an OEM Medium. The message format belongs to
3952  * the OEM.  See IPMI 2.0 specification, Chapter 6 and
3953  * Chapter 22, sections 22.6 and 22.24 for more details.
3954  */
3955 static int handle_oem_get_msg_cmd(ipmi_smi_t          intf,
3956 				  struct ipmi_smi_msg *msg)
3957 {
3958 	struct cmd_rcvr       *rcvr;
3959 	int                   rv = 0;
3960 	unsigned char         netfn;
3961 	unsigned char         cmd;
3962 	unsigned char         chan;
3963 	ipmi_user_t           user = NULL;
3964 	struct ipmi_system_interface_addr *smi_addr;
3965 	struct ipmi_recv_msg  *recv_msg;
3966 
3967 	/*
3968 	 * We expect the OEM SW to perform error checking
3969 	 * so we just do some basic sanity checks
3970 	 */
3971 	if (msg->rsp_size < 4) {
3972 		/* Message not big enough, just ignore it. */
3973 		ipmi_inc_stat(intf, invalid_commands);
3974 		return 0;
3975 	}
3976 
3977 	if (msg->rsp[2] != 0) {
3978 		/* An error getting the response, just ignore it. */
3979 		return 0;
3980 	}
3981 
3982 	/*
3983 	 * This is an OEM Message so the OEM needs to know how
3984 	 * handle the message. We do no interpretation.
3985 	 */
3986 	netfn = msg->rsp[0] >> 2;
3987 	cmd = msg->rsp[1];
3988 	chan = msg->rsp[3] & 0xf;
3989 
3990 	rcu_read_lock();
3991 	rcvr = find_cmd_rcvr(intf, netfn, cmd, chan);
3992 	if (rcvr) {
3993 		user = rcvr->user;
3994 		kref_get(&user->refcount);
3995 	} else
3996 		user = NULL;
3997 	rcu_read_unlock();
3998 
3999 	if (user == NULL) {
4000 		/* We didn't find a user, just give up. */
4001 		ipmi_inc_stat(intf, unhandled_commands);
4002 
4003 		/*
4004 		 * Don't do anything with these messages, just allow
4005 		 * them to be freed.
4006 		 */
4007 
4008 		rv = 0;
4009 	} else {
4010 		/* Deliver the message to the user. */
4011 		ipmi_inc_stat(intf, handled_commands);
4012 
4013 		recv_msg = ipmi_alloc_recv_msg();
4014 		if (!recv_msg) {
4015 			/*
4016 			 * We couldn't allocate memory for the
4017 			 * message, so requeue it for handling
4018 			 * later.
4019 			 */
4020 			rv = 1;
4021 			kref_put(&user->refcount, free_user);
4022 		} else {
4023 			/*
4024 			 * OEM Messages are expected to be delivered via
4025 			 * the system interface to SMS software.  We might
4026 			 * need to visit this again depending on OEM
4027 			 * requirements
4028 			 */
4029 			smi_addr = ((struct ipmi_system_interface_addr *)
4030 				    &(recv_msg->addr));
4031 			smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4032 			smi_addr->channel = IPMI_BMC_CHANNEL;
4033 			smi_addr->lun = msg->rsp[0] & 3;
4034 
4035 			recv_msg->user = user;
4036 			recv_msg->user_msg_data = NULL;
4037 			recv_msg->recv_type = IPMI_OEM_RECV_TYPE;
4038 			recv_msg->msg.netfn = msg->rsp[0] >> 2;
4039 			recv_msg->msg.cmd = msg->rsp[1];
4040 			recv_msg->msg.data = recv_msg->msg_data;
4041 
4042 			/*
4043 			 * The message starts at byte 4 which follows the
4044 			 * the Channel Byte in the "GET MESSAGE" command
4045 			 */
4046 			recv_msg->msg.data_len = msg->rsp_size - 4;
4047 			memcpy(recv_msg->msg_data,
4048 			       &(msg->rsp[4]),
4049 			       msg->rsp_size - 4);
4050 			deliver_response(recv_msg);
4051 		}
4052 	}
4053 
4054 	return rv;
4055 }
4056 
4057 static void copy_event_into_recv_msg(struct ipmi_recv_msg *recv_msg,
4058 				     struct ipmi_smi_msg  *msg)
4059 {
4060 	struct ipmi_system_interface_addr *smi_addr;
4061 
4062 	recv_msg->msgid = 0;
4063 	smi_addr = (struct ipmi_system_interface_addr *) &(recv_msg->addr);
4064 	smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4065 	smi_addr->channel = IPMI_BMC_CHANNEL;
4066 	smi_addr->lun = msg->rsp[0] & 3;
4067 	recv_msg->recv_type = IPMI_ASYNC_EVENT_RECV_TYPE;
4068 	recv_msg->msg.netfn = msg->rsp[0] >> 2;
4069 	recv_msg->msg.cmd = msg->rsp[1];
4070 	memcpy(recv_msg->msg_data, &(msg->rsp[3]), msg->rsp_size - 3);
4071 	recv_msg->msg.data = recv_msg->msg_data;
4072 	recv_msg->msg.data_len = msg->rsp_size - 3;
4073 }
4074 
4075 static int handle_read_event_rsp(ipmi_smi_t          intf,
4076 				 struct ipmi_smi_msg *msg)
4077 {
4078 	struct ipmi_recv_msg *recv_msg, *recv_msg2;
4079 	struct list_head     msgs;
4080 	ipmi_user_t          user;
4081 	int                  rv = 0;
4082 	int                  deliver_count = 0;
4083 	unsigned long        flags;
4084 
4085 	if (msg->rsp_size < 19) {
4086 		/* Message is too small to be an IPMB event. */
4087 		ipmi_inc_stat(intf, invalid_events);
4088 		return 0;
4089 	}
4090 
4091 	if (msg->rsp[2] != 0) {
4092 		/* An error getting the event, just ignore it. */
4093 		return 0;
4094 	}
4095 
4096 	INIT_LIST_HEAD(&msgs);
4097 
4098 	spin_lock_irqsave(&intf->events_lock, flags);
4099 
4100 	ipmi_inc_stat(intf, events);
4101 
4102 	/*
4103 	 * Allocate and fill in one message for every user that is
4104 	 * getting events.
4105 	 */
4106 	rcu_read_lock();
4107 	list_for_each_entry_rcu(user, &intf->users, link) {
4108 		if (!user->gets_events)
4109 			continue;
4110 
4111 		recv_msg = ipmi_alloc_recv_msg();
4112 		if (!recv_msg) {
4113 			rcu_read_unlock();
4114 			list_for_each_entry_safe(recv_msg, recv_msg2, &msgs,
4115 						 link) {
4116 				list_del(&recv_msg->link);
4117 				ipmi_free_recv_msg(recv_msg);
4118 			}
4119 			/*
4120 			 * We couldn't allocate memory for the
4121 			 * message, so requeue it for handling
4122 			 * later.
4123 			 */
4124 			rv = 1;
4125 			goto out;
4126 		}
4127 
4128 		deliver_count++;
4129 
4130 		copy_event_into_recv_msg(recv_msg, msg);
4131 		recv_msg->user = user;
4132 		kref_get(&user->refcount);
4133 		list_add_tail(&(recv_msg->link), &msgs);
4134 	}
4135 	rcu_read_unlock();
4136 
4137 	if (deliver_count) {
4138 		/* Now deliver all the messages. */
4139 		list_for_each_entry_safe(recv_msg, recv_msg2, &msgs, link) {
4140 			list_del(&recv_msg->link);
4141 			deliver_response(recv_msg);
4142 		}
4143 	} else if (intf->waiting_events_count < MAX_EVENTS_IN_QUEUE) {
4144 		/*
4145 		 * No one to receive the message, put it in queue if there's
4146 		 * not already too many things in the queue.
4147 		 */
4148 		recv_msg = ipmi_alloc_recv_msg();
4149 		if (!recv_msg) {
4150 			/*
4151 			 * We couldn't allocate memory for the
4152 			 * message, so requeue it for handling
4153 			 * later.
4154 			 */
4155 			rv = 1;
4156 			goto out;
4157 		}
4158 
4159 		copy_event_into_recv_msg(recv_msg, msg);
4160 		list_add_tail(&(recv_msg->link), &(intf->waiting_events));
4161 		intf->waiting_events_count++;
4162 	} else if (!intf->event_msg_printed) {
4163 		/*
4164 		 * There's too many things in the queue, discard this
4165 		 * message.
4166 		 */
4167 		dev_warn(intf->si_dev,
4168 			 PFX "Event queue full, discarding incoming events\n");
4169 		intf->event_msg_printed = 1;
4170 	}
4171 
4172  out:
4173 	spin_unlock_irqrestore(&(intf->events_lock), flags);
4174 
4175 	return rv;
4176 }
4177 
4178 static int handle_bmc_rsp(ipmi_smi_t          intf,
4179 			  struct ipmi_smi_msg *msg)
4180 {
4181 	struct ipmi_recv_msg *recv_msg;
4182 	struct ipmi_user     *user;
4183 
4184 	recv_msg = (struct ipmi_recv_msg *) msg->user_data;
4185 	if (recv_msg == NULL) {
4186 		dev_warn(intf->si_dev,
4187 			 "IPMI message received with no owner. This could be because of a malformed message, or because of a hardware error.  Contact your hardware vender for assistance\n");
4188 		return 0;
4189 	}
4190 
4191 	user = recv_msg->user;
4192 	/* Make sure the user still exists. */
4193 	if (user && !user->valid) {
4194 		/* The user for the message went away, so give up. */
4195 		ipmi_inc_stat(intf, unhandled_local_responses);
4196 		ipmi_free_recv_msg(recv_msg);
4197 	} else {
4198 		struct ipmi_system_interface_addr *smi_addr;
4199 
4200 		ipmi_inc_stat(intf, handled_local_responses);
4201 		recv_msg->recv_type = IPMI_RESPONSE_RECV_TYPE;
4202 		recv_msg->msgid = msg->msgid;
4203 		smi_addr = ((struct ipmi_system_interface_addr *)
4204 			    &(recv_msg->addr));
4205 		smi_addr->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4206 		smi_addr->channel = IPMI_BMC_CHANNEL;
4207 		smi_addr->lun = msg->rsp[0] & 3;
4208 		recv_msg->msg.netfn = msg->rsp[0] >> 2;
4209 		recv_msg->msg.cmd = msg->rsp[1];
4210 		memcpy(recv_msg->msg_data,
4211 		       &(msg->rsp[2]),
4212 		       msg->rsp_size - 2);
4213 		recv_msg->msg.data = recv_msg->msg_data;
4214 		recv_msg->msg.data_len = msg->rsp_size - 2;
4215 		deliver_response(recv_msg);
4216 	}
4217 
4218 	return 0;
4219 }
4220 
4221 /*
4222  * Handle a received message.  Return 1 if the message should be requeued,
4223  * 0 if the message should be freed, or -1 if the message should not
4224  * be freed or requeued.
4225  */
4226 static int handle_one_recv_msg(ipmi_smi_t          intf,
4227 			       struct ipmi_smi_msg *msg)
4228 {
4229 	int requeue;
4230 	int chan;
4231 
4232 #ifdef DEBUG_MSGING
4233 	int m;
4234 	printk("Recv:");
4235 	for (m = 0; m < msg->rsp_size; m++)
4236 		printk(" %2.2x", msg->rsp[m]);
4237 	printk("\n");
4238 #endif
4239 	if (msg->rsp_size < 2) {
4240 		/* Message is too small to be correct. */
4241 		dev_warn(intf->si_dev,
4242 			 PFX "BMC returned to small a message for netfn %x cmd %x, got %d bytes\n",
4243 			 (msg->data[0] >> 2) | 1, msg->data[1], msg->rsp_size);
4244 
4245 		/* Generate an error response for the message. */
4246 		msg->rsp[0] = msg->data[0] | (1 << 2);
4247 		msg->rsp[1] = msg->data[1];
4248 		msg->rsp[2] = IPMI_ERR_UNSPECIFIED;
4249 		msg->rsp_size = 3;
4250 	} else if (((msg->rsp[0] >> 2) != ((msg->data[0] >> 2) | 1))
4251 		   || (msg->rsp[1] != msg->data[1])) {
4252 		/*
4253 		 * The NetFN and Command in the response is not even
4254 		 * marginally correct.
4255 		 */
4256 		dev_warn(intf->si_dev,
4257 			 PFX "BMC returned incorrect response, expected netfn %x cmd %x, got netfn %x cmd %x\n",
4258 			 (msg->data[0] >> 2) | 1, msg->data[1],
4259 			 msg->rsp[0] >> 2, msg->rsp[1]);
4260 
4261 		/* Generate an error response for the message. */
4262 		msg->rsp[0] = msg->data[0] | (1 << 2);
4263 		msg->rsp[1] = msg->data[1];
4264 		msg->rsp[2] = IPMI_ERR_UNSPECIFIED;
4265 		msg->rsp_size = 3;
4266 	}
4267 
4268 	if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4269 	    && (msg->rsp[1] == IPMI_SEND_MSG_CMD)
4270 	    && (msg->user_data != NULL)) {
4271 		/*
4272 		 * It's a response to a response we sent.  For this we
4273 		 * deliver a send message response to the user.
4274 		 */
4275 		struct ipmi_recv_msg     *recv_msg = msg->user_data;
4276 
4277 		requeue = 0;
4278 		if (msg->rsp_size < 2)
4279 			/* Message is too small to be correct. */
4280 			goto out;
4281 
4282 		chan = msg->data[2] & 0x0f;
4283 		if (chan >= IPMI_MAX_CHANNELS)
4284 			/* Invalid channel number */
4285 			goto out;
4286 
4287 		if (!recv_msg)
4288 			goto out;
4289 
4290 		/* Make sure the user still exists. */
4291 		if (!recv_msg->user || !recv_msg->user->valid)
4292 			goto out;
4293 
4294 		recv_msg->recv_type = IPMI_RESPONSE_RESPONSE_TYPE;
4295 		recv_msg->msg.data = recv_msg->msg_data;
4296 		recv_msg->msg.data_len = 1;
4297 		recv_msg->msg_data[0] = msg->rsp[2];
4298 		deliver_response(recv_msg);
4299 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4300 		   && (msg->rsp[1] == IPMI_GET_MSG_CMD)) {
4301 		struct ipmi_channel   *chans;
4302 
4303 		/* It's from the receive queue. */
4304 		chan = msg->rsp[3] & 0xf;
4305 		if (chan >= IPMI_MAX_CHANNELS) {
4306 			/* Invalid channel number */
4307 			requeue = 0;
4308 			goto out;
4309 		}
4310 
4311 		/*
4312 		 * We need to make sure the channels have been initialized.
4313 		 * The channel_handler routine will set the "curr_channel"
4314 		 * equal to or greater than IPMI_MAX_CHANNELS when all the
4315 		 * channels for this interface have been initialized.
4316 		 */
4317 		if (!intf->channels_ready) {
4318 			requeue = 0; /* Throw the message away */
4319 			goto out;
4320 		}
4321 
4322 		chans = READ_ONCE(intf->channel_list)->c;
4323 
4324 		switch (chans[chan].medium) {
4325 		case IPMI_CHANNEL_MEDIUM_IPMB:
4326 			if (msg->rsp[4] & 0x04) {
4327 				/*
4328 				 * It's a response, so find the
4329 				 * requesting message and send it up.
4330 				 */
4331 				requeue = handle_ipmb_get_msg_rsp(intf, msg);
4332 			} else {
4333 				/*
4334 				 * It's a command to the SMS from some other
4335 				 * entity.  Handle that.
4336 				 */
4337 				requeue = handle_ipmb_get_msg_cmd(intf, msg);
4338 			}
4339 			break;
4340 
4341 		case IPMI_CHANNEL_MEDIUM_8023LAN:
4342 		case IPMI_CHANNEL_MEDIUM_ASYNC:
4343 			if (msg->rsp[6] & 0x04) {
4344 				/*
4345 				 * It's a response, so find the
4346 				 * requesting message and send it up.
4347 				 */
4348 				requeue = handle_lan_get_msg_rsp(intf, msg);
4349 			} else {
4350 				/*
4351 				 * It's a command to the SMS from some other
4352 				 * entity.  Handle that.
4353 				 */
4354 				requeue = handle_lan_get_msg_cmd(intf, msg);
4355 			}
4356 			break;
4357 
4358 		default:
4359 			/* Check for OEM Channels.  Clients had better
4360 			   register for these commands. */
4361 			if ((chans[chan].medium >= IPMI_CHANNEL_MEDIUM_OEM_MIN)
4362 			    && (chans[chan].medium
4363 				<= IPMI_CHANNEL_MEDIUM_OEM_MAX)) {
4364 				requeue = handle_oem_get_msg_cmd(intf, msg);
4365 			} else {
4366 				/*
4367 				 * We don't handle the channel type, so just
4368 				 * free the message.
4369 				 */
4370 				requeue = 0;
4371 			}
4372 		}
4373 
4374 	} else if ((msg->rsp[0] == ((IPMI_NETFN_APP_REQUEST|1) << 2))
4375 		   && (msg->rsp[1] == IPMI_READ_EVENT_MSG_BUFFER_CMD)) {
4376 		/* It's an asynchronous event. */
4377 		requeue = handle_read_event_rsp(intf, msg);
4378 	} else {
4379 		/* It's a response from the local BMC. */
4380 		requeue = handle_bmc_rsp(intf, msg);
4381 	}
4382 
4383  out:
4384 	return requeue;
4385 }
4386 
4387 /*
4388  * If there are messages in the queue or pretimeouts, handle them.
4389  */
4390 static void handle_new_recv_msgs(ipmi_smi_t intf)
4391 {
4392 	struct ipmi_smi_msg  *smi_msg;
4393 	unsigned long        flags = 0;
4394 	int                  rv;
4395 	int                  run_to_completion = intf->run_to_completion;
4396 
4397 	/* See if any waiting messages need to be processed. */
4398 	if (!run_to_completion)
4399 		spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4400 	while (!list_empty(&intf->waiting_rcv_msgs)) {
4401 		smi_msg = list_entry(intf->waiting_rcv_msgs.next,
4402 				     struct ipmi_smi_msg, link);
4403 		list_del(&smi_msg->link);
4404 		if (!run_to_completion)
4405 			spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
4406 					       flags);
4407 		rv = handle_one_recv_msg(intf, smi_msg);
4408 		if (!run_to_completion)
4409 			spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4410 		if (rv > 0) {
4411 			/*
4412 			 * To preserve message order, quit if we
4413 			 * can't handle a message.  Add the message
4414 			 * back at the head, this is safe because this
4415 			 * tasklet is the only thing that pulls the
4416 			 * messages.
4417 			 */
4418 			list_add(&smi_msg->link, &intf->waiting_rcv_msgs);
4419 			break;
4420 		} else {
4421 			if (rv == 0)
4422 				/* Message handled */
4423 				ipmi_free_smi_msg(smi_msg);
4424 			/* If rv < 0, fatal error, del but don't free. */
4425 		}
4426 	}
4427 	if (!run_to_completion)
4428 		spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock, flags);
4429 
4430 	/*
4431 	 * If the pretimout count is non-zero, decrement one from it and
4432 	 * deliver pretimeouts to all the users.
4433 	 */
4434 	if (atomic_add_unless(&intf->watchdog_pretimeouts_to_deliver, -1, 0)) {
4435 		ipmi_user_t user;
4436 
4437 		rcu_read_lock();
4438 		list_for_each_entry_rcu(user, &intf->users, link) {
4439 			if (user->handler->ipmi_watchdog_pretimeout)
4440 				user->handler->ipmi_watchdog_pretimeout(
4441 					user->handler_data);
4442 		}
4443 		rcu_read_unlock();
4444 	}
4445 }
4446 
4447 static void smi_recv_tasklet(unsigned long val)
4448 {
4449 	unsigned long flags = 0; /* keep us warning-free. */
4450 	ipmi_smi_t intf = (ipmi_smi_t) val;
4451 	int run_to_completion = intf->run_to_completion;
4452 	struct ipmi_smi_msg *newmsg = NULL;
4453 
4454 	/*
4455 	 * Start the next message if available.
4456 	 *
4457 	 * Do this here, not in the actual receiver, because we may deadlock
4458 	 * because the lower layer is allowed to hold locks while calling
4459 	 * message delivery.
4460 	 */
4461 
4462 	rcu_read_lock();
4463 
4464 	if (!run_to_completion)
4465 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
4466 	if (intf->curr_msg == NULL && !intf->in_shutdown) {
4467 		struct list_head *entry = NULL;
4468 
4469 		/* Pick the high priority queue first. */
4470 		if (!list_empty(&intf->hp_xmit_msgs))
4471 			entry = intf->hp_xmit_msgs.next;
4472 		else if (!list_empty(&intf->xmit_msgs))
4473 			entry = intf->xmit_msgs.next;
4474 
4475 		if (entry) {
4476 			list_del(entry);
4477 			newmsg = list_entry(entry, struct ipmi_smi_msg, link);
4478 			intf->curr_msg = newmsg;
4479 		}
4480 	}
4481 	if (!run_to_completion)
4482 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
4483 	if (newmsg)
4484 		intf->handlers->sender(intf->send_info, newmsg);
4485 
4486 	rcu_read_unlock();
4487 
4488 	handle_new_recv_msgs(intf);
4489 }
4490 
4491 /* Handle a new message from the lower layer. */
4492 void ipmi_smi_msg_received(ipmi_smi_t          intf,
4493 			   struct ipmi_smi_msg *msg)
4494 {
4495 	unsigned long flags = 0; /* keep us warning-free. */
4496 	int run_to_completion = intf->run_to_completion;
4497 
4498 	if ((msg->data_size >= 2)
4499 	    && (msg->data[0] == (IPMI_NETFN_APP_REQUEST << 2))
4500 	    && (msg->data[1] == IPMI_SEND_MSG_CMD)
4501 	    && (msg->user_data == NULL)) {
4502 
4503 		if (intf->in_shutdown)
4504 			goto free_msg;
4505 
4506 		/*
4507 		 * This is the local response to a command send, start
4508 		 * the timer for these.  The user_data will not be
4509 		 * NULL if this is a response send, and we will let
4510 		 * response sends just go through.
4511 		 */
4512 
4513 		/*
4514 		 * Check for errors, if we get certain errors (ones
4515 		 * that mean basically we can try again later), we
4516 		 * ignore them and start the timer.  Otherwise we
4517 		 * report the error immediately.
4518 		 */
4519 		if ((msg->rsp_size >= 3) && (msg->rsp[2] != 0)
4520 		    && (msg->rsp[2] != IPMI_NODE_BUSY_ERR)
4521 		    && (msg->rsp[2] != IPMI_LOST_ARBITRATION_ERR)
4522 		    && (msg->rsp[2] != IPMI_BUS_ERR)
4523 		    && (msg->rsp[2] != IPMI_NAK_ON_WRITE_ERR)) {
4524 			int ch = msg->rsp[3] & 0xf;
4525 			struct ipmi_channel *chans;
4526 
4527 			/* Got an error sending the message, handle it. */
4528 
4529 			chans = READ_ONCE(intf->channel_list)->c;
4530 			if ((chans[ch].medium == IPMI_CHANNEL_MEDIUM_8023LAN)
4531 			    || (chans[ch].medium == IPMI_CHANNEL_MEDIUM_ASYNC))
4532 				ipmi_inc_stat(intf, sent_lan_command_errs);
4533 			else
4534 				ipmi_inc_stat(intf, sent_ipmb_command_errs);
4535 			intf_err_seq(intf, msg->msgid, msg->rsp[2]);
4536 		} else
4537 			/* The message was sent, start the timer. */
4538 			intf_start_seq_timer(intf, msg->msgid);
4539 
4540 free_msg:
4541 		ipmi_free_smi_msg(msg);
4542 	} else {
4543 		/*
4544 		 * To preserve message order, we keep a queue and deliver from
4545 		 * a tasklet.
4546 		 */
4547 		if (!run_to_completion)
4548 			spin_lock_irqsave(&intf->waiting_rcv_msgs_lock, flags);
4549 		list_add_tail(&msg->link, &intf->waiting_rcv_msgs);
4550 		if (!run_to_completion)
4551 			spin_unlock_irqrestore(&intf->waiting_rcv_msgs_lock,
4552 					       flags);
4553 	}
4554 
4555 	if (!run_to_completion)
4556 		spin_lock_irqsave(&intf->xmit_msgs_lock, flags);
4557 	/*
4558 	 * We can get an asynchronous event or receive message in addition
4559 	 * to commands we send.
4560 	 */
4561 	if (msg == intf->curr_msg)
4562 		intf->curr_msg = NULL;
4563 	if (!run_to_completion)
4564 		spin_unlock_irqrestore(&intf->xmit_msgs_lock, flags);
4565 
4566 	if (run_to_completion)
4567 		smi_recv_tasklet((unsigned long) intf);
4568 	else
4569 		tasklet_schedule(&intf->recv_tasklet);
4570 }
4571 EXPORT_SYMBOL(ipmi_smi_msg_received);
4572 
4573 void ipmi_smi_watchdog_pretimeout(ipmi_smi_t intf)
4574 {
4575 	if (intf->in_shutdown)
4576 		return;
4577 
4578 	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 1);
4579 	tasklet_schedule(&intf->recv_tasklet);
4580 }
4581 EXPORT_SYMBOL(ipmi_smi_watchdog_pretimeout);
4582 
4583 static struct ipmi_smi_msg *
4584 smi_from_recv_msg(ipmi_smi_t intf, struct ipmi_recv_msg *recv_msg,
4585 		  unsigned char seq, long seqid)
4586 {
4587 	struct ipmi_smi_msg *smi_msg = ipmi_alloc_smi_msg();
4588 	if (!smi_msg)
4589 		/*
4590 		 * If we can't allocate the message, then just return, we
4591 		 * get 4 retries, so this should be ok.
4592 		 */
4593 		return NULL;
4594 
4595 	memcpy(smi_msg->data, recv_msg->msg.data, recv_msg->msg.data_len);
4596 	smi_msg->data_size = recv_msg->msg.data_len;
4597 	smi_msg->msgid = STORE_SEQ_IN_MSGID(seq, seqid);
4598 
4599 #ifdef DEBUG_MSGING
4600 	{
4601 		int m;
4602 		printk("Resend: ");
4603 		for (m = 0; m < smi_msg->data_size; m++)
4604 			printk(" %2.2x", smi_msg->data[m]);
4605 		printk("\n");
4606 	}
4607 #endif
4608 	return smi_msg;
4609 }
4610 
4611 static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent,
4612 			      struct list_head *timeouts,
4613 			      unsigned long timeout_period,
4614 			      int slot, unsigned long *flags,
4615 			      unsigned int *waiting_msgs)
4616 {
4617 	struct ipmi_recv_msg     *msg;
4618 	const struct ipmi_smi_handlers *handlers;
4619 
4620 	if (intf->in_shutdown)
4621 		return;
4622 
4623 	if (!ent->inuse)
4624 		return;
4625 
4626 	if (timeout_period < ent->timeout) {
4627 		ent->timeout -= timeout_period;
4628 		(*waiting_msgs)++;
4629 		return;
4630 	}
4631 
4632 	if (ent->retries_left == 0) {
4633 		/* The message has used all its retries. */
4634 		ent->inuse = 0;
4635 		msg = ent->recv_msg;
4636 		list_add_tail(&msg->link, timeouts);
4637 		if (ent->broadcast)
4638 			ipmi_inc_stat(intf, timed_out_ipmb_broadcasts);
4639 		else if (is_lan_addr(&ent->recv_msg->addr))
4640 			ipmi_inc_stat(intf, timed_out_lan_commands);
4641 		else
4642 			ipmi_inc_stat(intf, timed_out_ipmb_commands);
4643 	} else {
4644 		struct ipmi_smi_msg *smi_msg;
4645 		/* More retries, send again. */
4646 
4647 		(*waiting_msgs)++;
4648 
4649 		/*
4650 		 * Start with the max timer, set to normal timer after
4651 		 * the message is sent.
4652 		 */
4653 		ent->timeout = MAX_MSG_TIMEOUT;
4654 		ent->retries_left--;
4655 		smi_msg = smi_from_recv_msg(intf, ent->recv_msg, slot,
4656 					    ent->seqid);
4657 		if (!smi_msg) {
4658 			if (is_lan_addr(&ent->recv_msg->addr))
4659 				ipmi_inc_stat(intf,
4660 					      dropped_rexmit_lan_commands);
4661 			else
4662 				ipmi_inc_stat(intf,
4663 					      dropped_rexmit_ipmb_commands);
4664 			return;
4665 		}
4666 
4667 		spin_unlock_irqrestore(&intf->seq_lock, *flags);
4668 
4669 		/*
4670 		 * Send the new message.  We send with a zero
4671 		 * priority.  It timed out, I doubt time is that
4672 		 * critical now, and high priority messages are really
4673 		 * only for messages to the local MC, which don't get
4674 		 * resent.
4675 		 */
4676 		handlers = intf->handlers;
4677 		if (handlers) {
4678 			if (is_lan_addr(&ent->recv_msg->addr))
4679 				ipmi_inc_stat(intf,
4680 					      retransmitted_lan_commands);
4681 			else
4682 				ipmi_inc_stat(intf,
4683 					      retransmitted_ipmb_commands);
4684 
4685 			smi_send(intf, handlers, smi_msg, 0);
4686 		} else
4687 			ipmi_free_smi_msg(smi_msg);
4688 
4689 		spin_lock_irqsave(&intf->seq_lock, *flags);
4690 	}
4691 }
4692 
4693 static unsigned int ipmi_timeout_handler(ipmi_smi_t intf,
4694 					 unsigned long timeout_period)
4695 {
4696 	struct list_head     timeouts;
4697 	struct ipmi_recv_msg *msg, *msg2;
4698 	unsigned long        flags;
4699 	int                  i;
4700 	unsigned int         waiting_msgs = 0;
4701 
4702 	if (!intf->bmc_registered) {
4703 		kref_get(&intf->refcount);
4704 		if (!schedule_work(&intf->bmc_reg_work)) {
4705 			kref_put(&intf->refcount, intf_free);
4706 			waiting_msgs++;
4707 		}
4708 	}
4709 
4710 	/*
4711 	 * Go through the seq table and find any messages that
4712 	 * have timed out, putting them in the timeouts
4713 	 * list.
4714 	 */
4715 	INIT_LIST_HEAD(&timeouts);
4716 	spin_lock_irqsave(&intf->seq_lock, flags);
4717 	for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++)
4718 		check_msg_timeout(intf, &(intf->seq_table[i]),
4719 				  &timeouts, timeout_period, i,
4720 				  &flags, &waiting_msgs);
4721 	spin_unlock_irqrestore(&intf->seq_lock, flags);
4722 
4723 	list_for_each_entry_safe(msg, msg2, &timeouts, link)
4724 		deliver_err_response(msg, IPMI_TIMEOUT_COMPLETION_CODE);
4725 
4726 	/*
4727 	 * Maintenance mode handling.  Check the timeout
4728 	 * optimistically before we claim the lock.  It may
4729 	 * mean a timeout gets missed occasionally, but that
4730 	 * only means the timeout gets extended by one period
4731 	 * in that case.  No big deal, and it avoids the lock
4732 	 * most of the time.
4733 	 */
4734 	if (intf->auto_maintenance_timeout > 0) {
4735 		spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
4736 		if (intf->auto_maintenance_timeout > 0) {
4737 			intf->auto_maintenance_timeout
4738 				-= timeout_period;
4739 			if (!intf->maintenance_mode
4740 			    && (intf->auto_maintenance_timeout <= 0)) {
4741 				intf->maintenance_mode_enable = false;
4742 				maintenance_mode_update(intf);
4743 			}
4744 		}
4745 		spin_unlock_irqrestore(&intf->maintenance_mode_lock,
4746 				       flags);
4747 	}
4748 
4749 	tasklet_schedule(&intf->recv_tasklet);
4750 
4751 	return waiting_msgs;
4752 }
4753 
4754 static void ipmi_request_event(ipmi_smi_t intf)
4755 {
4756 	/* No event requests when in maintenance mode. */
4757 	if (intf->maintenance_mode_enable)
4758 		return;
4759 
4760 	if (!intf->in_shutdown)
4761 		intf->handlers->request_events(intf->send_info);
4762 }
4763 
4764 static struct timer_list ipmi_timer;
4765 
4766 static atomic_t stop_operation;
4767 
4768 static void ipmi_timeout(struct timer_list *unused)
4769 {
4770 	ipmi_smi_t intf;
4771 	int nt = 0;
4772 
4773 	if (atomic_read(&stop_operation))
4774 		return;
4775 
4776 	rcu_read_lock();
4777 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
4778 		int lnt = 0;
4779 
4780 		if (atomic_read(&intf->event_waiters)) {
4781 			intf->ticks_to_req_ev--;
4782 			if (intf->ticks_to_req_ev == 0) {
4783 				ipmi_request_event(intf);
4784 				intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
4785 			}
4786 			lnt++;
4787 		}
4788 
4789 		lnt += ipmi_timeout_handler(intf, IPMI_TIMEOUT_TIME);
4790 
4791 		lnt = !!lnt;
4792 		if (lnt != intf->last_needs_timer &&
4793 					intf->handlers->set_need_watch)
4794 			intf->handlers->set_need_watch(intf->send_info, lnt);
4795 		intf->last_needs_timer = lnt;
4796 
4797 		nt += lnt;
4798 	}
4799 	rcu_read_unlock();
4800 
4801 	if (nt)
4802 		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
4803 }
4804 
4805 static void need_waiter(ipmi_smi_t intf)
4806 {
4807 	/* Racy, but worst case we start the timer twice. */
4808 	if (!timer_pending(&ipmi_timer))
4809 		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
4810 }
4811 
4812 static atomic_t smi_msg_inuse_count = ATOMIC_INIT(0);
4813 static atomic_t recv_msg_inuse_count = ATOMIC_INIT(0);
4814 
4815 static void free_smi_msg(struct ipmi_smi_msg *msg)
4816 {
4817 	atomic_dec(&smi_msg_inuse_count);
4818 	kfree(msg);
4819 }
4820 
4821 struct ipmi_smi_msg *ipmi_alloc_smi_msg(void)
4822 {
4823 	struct ipmi_smi_msg *rv;
4824 	rv = kmalloc(sizeof(struct ipmi_smi_msg), GFP_ATOMIC);
4825 	if (rv) {
4826 		rv->done = free_smi_msg;
4827 		rv->user_data = NULL;
4828 		atomic_inc(&smi_msg_inuse_count);
4829 	}
4830 	return rv;
4831 }
4832 EXPORT_SYMBOL(ipmi_alloc_smi_msg);
4833 
4834 static void free_recv_msg(struct ipmi_recv_msg *msg)
4835 {
4836 	atomic_dec(&recv_msg_inuse_count);
4837 	kfree(msg);
4838 }
4839 
4840 static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void)
4841 {
4842 	struct ipmi_recv_msg *rv;
4843 
4844 	rv = kmalloc(sizeof(struct ipmi_recv_msg), GFP_ATOMIC);
4845 	if (rv) {
4846 		rv->user = NULL;
4847 		rv->done = free_recv_msg;
4848 		atomic_inc(&recv_msg_inuse_count);
4849 	}
4850 	return rv;
4851 }
4852 
4853 void ipmi_free_recv_msg(struct ipmi_recv_msg *msg)
4854 {
4855 	if (msg->user)
4856 		kref_put(&msg->user->refcount, free_user);
4857 	msg->done(msg);
4858 }
4859 EXPORT_SYMBOL(ipmi_free_recv_msg);
4860 
4861 static atomic_t panic_done_count = ATOMIC_INIT(0);
4862 
4863 static void dummy_smi_done_handler(struct ipmi_smi_msg *msg)
4864 {
4865 	atomic_dec(&panic_done_count);
4866 }
4867 
4868 static void dummy_recv_done_handler(struct ipmi_recv_msg *msg)
4869 {
4870 	atomic_dec(&panic_done_count);
4871 }
4872 
4873 /*
4874  * Inside a panic, send a message and wait for a response.
4875  */
4876 static void ipmi_panic_request_and_wait(ipmi_smi_t           intf,
4877 					struct ipmi_addr     *addr,
4878 					struct kernel_ipmi_msg *msg)
4879 {
4880 	struct ipmi_smi_msg  smi_msg;
4881 	struct ipmi_recv_msg recv_msg;
4882 	int rv;
4883 
4884 	smi_msg.done = dummy_smi_done_handler;
4885 	recv_msg.done = dummy_recv_done_handler;
4886 	atomic_add(2, &panic_done_count);
4887 	rv = i_ipmi_request(NULL,
4888 			    intf,
4889 			    addr,
4890 			    0,
4891 			    msg,
4892 			    intf,
4893 			    &smi_msg,
4894 			    &recv_msg,
4895 			    0,
4896 			    intf->addrinfo[0].address,
4897 			    intf->addrinfo[0].lun,
4898 			    0, 1); /* Don't retry, and don't wait. */
4899 	if (rv)
4900 		atomic_sub(2, &panic_done_count);
4901 	else if (intf->handlers->flush_messages)
4902 		intf->handlers->flush_messages(intf->send_info);
4903 
4904 	while (atomic_read(&panic_done_count) != 0)
4905 		ipmi_poll(intf);
4906 }
4907 
4908 static void event_receiver_fetcher(ipmi_smi_t intf, struct ipmi_recv_msg *msg)
4909 {
4910 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
4911 	    && (msg->msg.netfn == IPMI_NETFN_SENSOR_EVENT_RESPONSE)
4912 	    && (msg->msg.cmd == IPMI_GET_EVENT_RECEIVER_CMD)
4913 	    && (msg->msg.data[0] == IPMI_CC_NO_ERROR)) {
4914 		/* A get event receiver command, save it. */
4915 		intf->event_receiver = msg->msg.data[1];
4916 		intf->event_receiver_lun = msg->msg.data[2] & 0x3;
4917 	}
4918 }
4919 
4920 static void device_id_fetcher(ipmi_smi_t intf, struct ipmi_recv_msg *msg)
4921 {
4922 	if ((msg->addr.addr_type == IPMI_SYSTEM_INTERFACE_ADDR_TYPE)
4923 	    && (msg->msg.netfn == IPMI_NETFN_APP_RESPONSE)
4924 	    && (msg->msg.cmd == IPMI_GET_DEVICE_ID_CMD)
4925 	    && (msg->msg.data[0] == IPMI_CC_NO_ERROR)) {
4926 		/*
4927 		 * A get device id command, save if we are an event
4928 		 * receiver or generator.
4929 		 */
4930 		intf->local_sel_device = (msg->msg.data[6] >> 2) & 1;
4931 		intf->local_event_generator = (msg->msg.data[6] >> 5) & 1;
4932 	}
4933 }
4934 
4935 static void send_panic_events(char *str)
4936 {
4937 	struct kernel_ipmi_msg            msg;
4938 	ipmi_smi_t                        intf;
4939 	unsigned char                     data[16];
4940 	struct ipmi_system_interface_addr *si;
4941 	struct ipmi_addr                  addr;
4942 
4943 	if (ipmi_send_panic_event == IPMI_SEND_PANIC_EVENT_NONE)
4944 		return;
4945 
4946 	si = (struct ipmi_system_interface_addr *) &addr;
4947 	si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
4948 	si->channel = IPMI_BMC_CHANNEL;
4949 	si->lun = 0;
4950 
4951 	/* Fill in an event telling that we have failed. */
4952 	msg.netfn = 0x04; /* Sensor or Event. */
4953 	msg.cmd = 2; /* Platform event command. */
4954 	msg.data = data;
4955 	msg.data_len = 8;
4956 	data[0] = 0x41; /* Kernel generator ID, IPMI table 5-4 */
4957 	data[1] = 0x03; /* This is for IPMI 1.0. */
4958 	data[2] = 0x20; /* OS Critical Stop, IPMI table 36-3 */
4959 	data[4] = 0x6f; /* Sensor specific, IPMI table 36-1 */
4960 	data[5] = 0xa1; /* Runtime stop OEM bytes 2 & 3. */
4961 
4962 	/*
4963 	 * Put a few breadcrumbs in.  Hopefully later we can add more things
4964 	 * to make the panic events more useful.
4965 	 */
4966 	if (str) {
4967 		data[3] = str[0];
4968 		data[6] = str[1];
4969 		data[7] = str[2];
4970 	}
4971 
4972 	/* For every registered interface, send the event. */
4973 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
4974 		if (!intf->handlers || !intf->handlers->poll)
4975 			/* Interface is not ready or can't run at panic time. */
4976 			continue;
4977 
4978 		/* Send the event announcing the panic. */
4979 		ipmi_panic_request_and_wait(intf, &addr, &msg);
4980 	}
4981 
4982 	/*
4983 	 * On every interface, dump a bunch of OEM event holding the
4984 	 * string.
4985 	 */
4986 	if (ipmi_send_panic_event != IPMI_SEND_PANIC_EVENT_STRING || !str)
4987 		return;
4988 
4989 	/* For every registered interface, send the event. */
4990 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
4991 		char                  *p = str;
4992 		struct ipmi_ipmb_addr *ipmb;
4993 		int                   j;
4994 
4995 		if (intf->intf_num == -1)
4996 			/* Interface was not ready yet. */
4997 			continue;
4998 
4999 		/*
5000 		 * intf_num is used as an marker to tell if the
5001 		 * interface is valid.  Thus we need a read barrier to
5002 		 * make sure data fetched before checking intf_num
5003 		 * won't be used.
5004 		 */
5005 		smp_rmb();
5006 
5007 		/*
5008 		 * First job here is to figure out where to send the
5009 		 * OEM events.  There's no way in IPMI to send OEM
5010 		 * events using an event send command, so we have to
5011 		 * find the SEL to put them in and stick them in
5012 		 * there.
5013 		 */
5014 
5015 		/* Get capabilities from the get device id. */
5016 		intf->local_sel_device = 0;
5017 		intf->local_event_generator = 0;
5018 		intf->event_receiver = 0;
5019 
5020 		/* Request the device info from the local MC. */
5021 		msg.netfn = IPMI_NETFN_APP_REQUEST;
5022 		msg.cmd = IPMI_GET_DEVICE_ID_CMD;
5023 		msg.data = NULL;
5024 		msg.data_len = 0;
5025 		intf->null_user_handler = device_id_fetcher;
5026 		ipmi_panic_request_and_wait(intf, &addr, &msg);
5027 
5028 		if (intf->local_event_generator) {
5029 			/* Request the event receiver from the local MC. */
5030 			msg.netfn = IPMI_NETFN_SENSOR_EVENT_REQUEST;
5031 			msg.cmd = IPMI_GET_EVENT_RECEIVER_CMD;
5032 			msg.data = NULL;
5033 			msg.data_len = 0;
5034 			intf->null_user_handler = event_receiver_fetcher;
5035 			ipmi_panic_request_and_wait(intf, &addr, &msg);
5036 		}
5037 		intf->null_user_handler = NULL;
5038 
5039 		/*
5040 		 * Validate the event receiver.  The low bit must not
5041 		 * be 1 (it must be a valid IPMB address), it cannot
5042 		 * be zero, and it must not be my address.
5043 		 */
5044 		if (((intf->event_receiver & 1) == 0)
5045 		    && (intf->event_receiver != 0)
5046 		    && (intf->event_receiver != intf->addrinfo[0].address)) {
5047 			/*
5048 			 * The event receiver is valid, send an IPMB
5049 			 * message.
5050 			 */
5051 			ipmb = (struct ipmi_ipmb_addr *) &addr;
5052 			ipmb->addr_type = IPMI_IPMB_ADDR_TYPE;
5053 			ipmb->channel = 0; /* FIXME - is this right? */
5054 			ipmb->lun = intf->event_receiver_lun;
5055 			ipmb->slave_addr = intf->event_receiver;
5056 		} else if (intf->local_sel_device) {
5057 			/*
5058 			 * The event receiver was not valid (or was
5059 			 * me), but I am an SEL device, just dump it
5060 			 * in my SEL.
5061 			 */
5062 			si = (struct ipmi_system_interface_addr *) &addr;
5063 			si->addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
5064 			si->channel = IPMI_BMC_CHANNEL;
5065 			si->lun = 0;
5066 		} else
5067 			continue; /* No where to send the event. */
5068 
5069 		msg.netfn = IPMI_NETFN_STORAGE_REQUEST; /* Storage. */
5070 		msg.cmd = IPMI_ADD_SEL_ENTRY_CMD;
5071 		msg.data = data;
5072 		msg.data_len = 16;
5073 
5074 		j = 0;
5075 		while (*p) {
5076 			int size = strlen(p);
5077 
5078 			if (size > 11)
5079 				size = 11;
5080 			data[0] = 0;
5081 			data[1] = 0;
5082 			data[2] = 0xf0; /* OEM event without timestamp. */
5083 			data[3] = intf->addrinfo[0].address;
5084 			data[4] = j++; /* sequence # */
5085 			/*
5086 			 * Always give 11 bytes, so strncpy will fill
5087 			 * it with zeroes for me.
5088 			 */
5089 			strncpy(data+5, p, 11);
5090 			p += size;
5091 
5092 			ipmi_panic_request_and_wait(intf, &addr, &msg);
5093 		}
5094 	}
5095 }
5096 
5097 static int has_panicked;
5098 
5099 static int panic_event(struct notifier_block *this,
5100 		       unsigned long         event,
5101 		       void                  *ptr)
5102 {
5103 	ipmi_smi_t intf;
5104 
5105 	if (has_panicked)
5106 		return NOTIFY_DONE;
5107 	has_panicked = 1;
5108 
5109 	/* For every registered interface, set it to run to completion. */
5110 	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
5111 		if (!intf->handlers)
5112 			/* Interface is not ready. */
5113 			continue;
5114 
5115 		/*
5116 		 * If we were interrupted while locking xmit_msgs_lock or
5117 		 * waiting_rcv_msgs_lock, the corresponding list may be
5118 		 * corrupted.  In this case, drop items on the list for
5119 		 * the safety.
5120 		 */
5121 		if (!spin_trylock(&intf->xmit_msgs_lock)) {
5122 			INIT_LIST_HEAD(&intf->xmit_msgs);
5123 			INIT_LIST_HEAD(&intf->hp_xmit_msgs);
5124 		} else
5125 			spin_unlock(&intf->xmit_msgs_lock);
5126 
5127 		if (!spin_trylock(&intf->waiting_rcv_msgs_lock))
5128 			INIT_LIST_HEAD(&intf->waiting_rcv_msgs);
5129 		else
5130 			spin_unlock(&intf->waiting_rcv_msgs_lock);
5131 
5132 		intf->run_to_completion = 1;
5133 		if (intf->handlers->set_run_to_completion)
5134 			intf->handlers->set_run_to_completion(intf->send_info,
5135 							      1);
5136 	}
5137 
5138 	send_panic_events(ptr);
5139 
5140 	return NOTIFY_DONE;
5141 }
5142 
5143 static struct notifier_block panic_block = {
5144 	.notifier_call	= panic_event,
5145 	.next		= NULL,
5146 	.priority	= 200	/* priority: INT_MAX >= x >= 0 */
5147 };
5148 
5149 static int ipmi_init_msghandler(void)
5150 {
5151 	int rv;
5152 
5153 	if (initialized)
5154 		return 0;
5155 
5156 	rv = driver_register(&ipmidriver.driver);
5157 	if (rv) {
5158 		pr_err(PFX "Could not register IPMI driver\n");
5159 		return rv;
5160 	}
5161 
5162 	pr_info("ipmi message handler version " IPMI_DRIVER_VERSION "\n");
5163 
5164 #ifdef CONFIG_IPMI_PROC_INTERFACE
5165 	proc_ipmi_root = proc_mkdir("ipmi", NULL);
5166 	if (!proc_ipmi_root) {
5167 	    pr_err(PFX "Unable to create IPMI proc dir");
5168 	    driver_unregister(&ipmidriver.driver);
5169 	    return -ENOMEM;
5170 	}
5171 
5172 #endif /* CONFIG_IPMI_PROC_INTERFACE */
5173 
5174 	timer_setup(&ipmi_timer, ipmi_timeout, 0);
5175 	mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
5176 
5177 	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
5178 
5179 	initialized = 1;
5180 
5181 	return 0;
5182 }
5183 
5184 static int __init ipmi_init_msghandler_mod(void)
5185 {
5186 	ipmi_init_msghandler();
5187 	return 0;
5188 }
5189 
5190 static void __exit cleanup_ipmi(void)
5191 {
5192 	int count;
5193 
5194 	if (!initialized)
5195 		return;
5196 
5197 	atomic_notifier_chain_unregister(&panic_notifier_list, &panic_block);
5198 
5199 	/*
5200 	 * This can't be called if any interfaces exist, so no worry
5201 	 * about shutting down the interfaces.
5202 	 */
5203 
5204 	/*
5205 	 * Tell the timer to stop, then wait for it to stop.  This
5206 	 * avoids problems with race conditions removing the timer
5207 	 * here.
5208 	 */
5209 	atomic_inc(&stop_operation);
5210 	del_timer_sync(&ipmi_timer);
5211 
5212 #ifdef CONFIG_IPMI_PROC_INTERFACE
5213 	proc_remove(proc_ipmi_root);
5214 #endif /* CONFIG_IPMI_PROC_INTERFACE */
5215 
5216 	driver_unregister(&ipmidriver.driver);
5217 
5218 	initialized = 0;
5219 
5220 	/* Check for buffer leaks. */
5221 	count = atomic_read(&smi_msg_inuse_count);
5222 	if (count != 0)
5223 		pr_warn(PFX "SMI message count %d at exit\n", count);
5224 	count = atomic_read(&recv_msg_inuse_count);
5225 	if (count != 0)
5226 		pr_warn(PFX "recv message count %d at exit\n", count);
5227 }
5228 module_exit(cleanup_ipmi);
5229 
5230 module_init(ipmi_init_msghandler_mod);
5231 MODULE_LICENSE("GPL");
5232 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
5233 MODULE_DESCRIPTION("Incoming and outgoing message routing for an IPMI"
5234 		   " interface.");
5235 MODULE_VERSION(IPMI_DRIVER_VERSION);
5236 MODULE_SOFTDEP("post: ipmi_devintf");
5237