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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright(c) 2007 Intel Corporation. All rights reserved.
4 * Copyright(c) 2008 Red Hat, Inc. All rights reserved.
5 * Copyright(c) 2008 Mike Christie
6 *
7 * Maintained at www.Open-FCoE.org
8 */
9
10/*
11 * Fibre Channel exchange and sequence handling.
12 */
13
14#include <linux/timer.h>
15#include <linux/slab.h>
16#include <linux/err.h>
17#include <linux/export.h>
18#include <linux/log2.h>
19
20#include <scsi/fc/fc_fc2.h>
21
22#include <scsi/libfc.h>
23
24#include "fc_libfc.h"
25
26u16 fc_cpu_mask; /* cpu mask for possible cpus */
27EXPORT_SYMBOL(fc_cpu_mask);
28static u16 fc_cpu_order; /* 2's power to represent total possible cpus */
29static struct kmem_cache *fc_em_cachep; /* cache for exchanges */
30static struct workqueue_struct *fc_exch_workqueue;
31
32/*
33 * Structure and function definitions for managing Fibre Channel Exchanges
34 * and Sequences.
35 *
36 * The three primary structures used here are fc_exch_mgr, fc_exch, and fc_seq.
37 *
38 * fc_exch_mgr holds the exchange state for an N port
39 *
40 * fc_exch holds state for one exchange and links to its active sequence.
41 *
42 * fc_seq holds the state for an individual sequence.
43 */
44
45/**
46 * struct fc_exch_pool - Per cpu exchange pool
47 * @next_index: Next possible free exchange index
48 * @total_exches: Total allocated exchanges
49 * @lock: Exch pool lock
50 * @ex_list: List of exchanges
51 * @left: Cache of free slot in exch array
52 * @right: Cache of free slot in exch array
53 *
54 * This structure manages per cpu exchanges in array of exchange pointers.
55 * This array is allocated followed by struct fc_exch_pool memory for
56 * assigned range of exchanges to per cpu pool.
57 */
58struct fc_exch_pool {
59 spinlock_t lock;
60 struct list_head ex_list;
61 u16 next_index;
62 u16 total_exches;
63
64 u16 left;
65 u16 right;
66} ____cacheline_aligned_in_smp;
67
68/**
69 * struct fc_exch_mgr - The Exchange Manager (EM).
70 * @class: Default class for new sequences
71 * @kref: Reference counter
72 * @min_xid: Minimum exchange ID
73 * @max_xid: Maximum exchange ID
74 * @ep_pool: Reserved exchange pointers
75 * @pool_max_index: Max exch array index in exch pool
76 * @pool: Per cpu exch pool
77 * @lport: Local exchange port
78 * @stats: Statistics structure
79 *
80 * This structure is the center for creating exchanges and sequences.
81 * It manages the allocation of exchange IDs.
82 */
83struct fc_exch_mgr {
84 struct fc_exch_pool __percpu *pool;
85 mempool_t *ep_pool;
86 struct fc_lport *lport;
87 enum fc_class class;
88 struct kref kref;
89 u16 min_xid;
90 u16 max_xid;
91 u16 pool_max_index;
92
93 struct {
94 atomic_t no_free_exch;
95 atomic_t no_free_exch_xid;
96 atomic_t xid_not_found;
97 atomic_t xid_busy;
98 atomic_t seq_not_found;
99 atomic_t non_bls_resp;
100 } stats;
101};
102
103/**
104 * struct fc_exch_mgr_anchor - primary structure for list of EMs
105 * @ema_list: Exchange Manager Anchor list
106 * @mp: Exchange Manager associated with this anchor
107 * @match: Routine to determine if this anchor's EM should be used
108 *
109 * When walking the list of anchors the match routine will be called
110 * for each anchor to determine if that EM should be used. The last
111 * anchor in the list will always match to handle any exchanges not
112 * handled by other EMs. The non-default EMs would be added to the
113 * anchor list by HW that provides offloads.
114 */
115struct fc_exch_mgr_anchor {
116 struct list_head ema_list;
117 struct fc_exch_mgr *mp;
118 bool (*match)(struct fc_frame *);
119};
120
121static void fc_exch_rrq(struct fc_exch *);
122static void fc_seq_ls_acc(struct fc_frame *);
123static void fc_seq_ls_rjt(struct fc_frame *, enum fc_els_rjt_reason,
124 enum fc_els_rjt_explan);
125static void fc_exch_els_rec(struct fc_frame *);
126static void fc_exch_els_rrq(struct fc_frame *);
127
128/*
129 * Internal implementation notes.
130 *
131 * The exchange manager is one by default in libfc but LLD may choose
132 * to have one per CPU. The sequence manager is one per exchange manager
133 * and currently never separated.
134 *
135 * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field
136 * assigned by the Sequence Initiator that shall be unique for a specific
137 * D_ID and S_ID pair while the Sequence is open." Note that it isn't
138 * qualified by exchange ID, which one might think it would be.
139 * In practice this limits the number of open sequences and exchanges to 256
140 * per session. For most targets we could treat this limit as per exchange.
141 *
142 * The exchange and its sequence are freed when the last sequence is received.
143 * It's possible for the remote port to leave an exchange open without
144 * sending any sequences.
145 *
146 * Notes on reference counts:
147 *
148 * Exchanges are reference counted and exchange gets freed when the reference
149 * count becomes zero.
150 *
151 * Timeouts:
152 * Sequences are timed out for E_D_TOV and R_A_TOV.
153 *
154 * Sequence event handling:
155 *
156 * The following events may occur on initiator sequences:
157 *
158 * Send.
159 * For now, the whole thing is sent.
160 * Receive ACK
161 * This applies only to class F.
162 * The sequence is marked complete.
163 * ULP completion.
164 * The upper layer calls fc_exch_done() when done
165 * with exchange and sequence tuple.
166 * RX-inferred completion.
167 * When we receive the next sequence on the same exchange, we can
168 * retire the previous sequence ID. (XXX not implemented).
169 * Timeout.
170 * R_A_TOV frees the sequence ID. If we're waiting for ACK,
171 * E_D_TOV causes abort and calls upper layer response handler
172 * with FC_EX_TIMEOUT error.
173 * Receive RJT
174 * XXX defer.
175 * Send ABTS
176 * On timeout.
177 *
178 * The following events may occur on recipient sequences:
179 *
180 * Receive
181 * Allocate sequence for first frame received.
182 * Hold during receive handler.
183 * Release when final frame received.
184 * Keep status of last N of these for the ELS RES command. XXX TBD.
185 * Receive ABTS
186 * Deallocate sequence
187 * Send RJT
188 * Deallocate
189 *
190 * For now, we neglect conditions where only part of a sequence was
191 * received or transmitted, or where out-of-order receipt is detected.
192 */
193
194/*
195 * Locking notes:
196 *
197 * The EM code run in a per-CPU worker thread.
198 *
199 * To protect against concurrency between a worker thread code and timers,
200 * sequence allocation and deallocation must be locked.
201 * - exchange refcnt can be done atomicly without locks.
202 * - sequence allocation must be locked by exch lock.
203 * - If the EM pool lock and ex_lock must be taken at the same time, then the
204 * EM pool lock must be taken before the ex_lock.
205 */
206
207/*
208 * opcode names for debugging.
209 */
210static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;
211
212/**
213 * fc_exch_name_lookup() - Lookup name by opcode
214 * @op: Opcode to be looked up
215 * @table: Opcode/name table
216 * @max_index: Index not to be exceeded
217 *
218 * This routine is used to determine a human-readable string identifying
219 * a R_CTL opcode.
220 */
221static inline const char *fc_exch_name_lookup(unsigned int op, char **table,
222 unsigned int max_index)
223{
224 const char *name = NULL;
225
226 if (op < max_index)
227 name = table[op];
228 if (!name)
229 name = "unknown";
230 return name;
231}
232
233/**
234 * fc_exch_rctl_name() - Wrapper routine for fc_exch_name_lookup()
235 * @op: The opcode to be looked up
236 */
237static const char *fc_exch_rctl_name(unsigned int op)
238{
239 return fc_exch_name_lookup(op, fc_exch_rctl_names,
240 ARRAY_SIZE(fc_exch_rctl_names));
241}
242
243/**
244 * fc_exch_hold() - Increment an exchange's reference count
245 * @ep: Echange to be held
246 */
247static inline void fc_exch_hold(struct fc_exch *ep)
248{
249 atomic_inc(&ep->ex_refcnt);
250}
251
252/**
253 * fc_exch_setup_hdr() - Initialize a FC header by initializing some fields
254 * and determine SOF and EOF.
255 * @ep: The exchange to that will use the header
256 * @fp: The frame whose header is to be modified
257 * @f_ctl: F_CTL bits that will be used for the frame header
258 *
259 * The fields initialized by this routine are: fh_ox_id, fh_rx_id,
260 * fh_seq_id, fh_seq_cnt and the SOF and EOF.
261 */
262static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,
263 u32 f_ctl)
264{
265 struct fc_frame_header *fh = fc_frame_header_get(fp);
266 u16 fill;
267
268 fr_sof(fp) = ep->class;
269 if (ep->seq.cnt)
270 fr_sof(fp) = fc_sof_normal(ep->class);
271
272 if (f_ctl & FC_FC_END_SEQ) {
273 fr_eof(fp) = FC_EOF_T;
274 if (fc_sof_needs_ack((enum fc_sof)ep->class))
275 fr_eof(fp) = FC_EOF_N;
276 /*
277 * From F_CTL.
278 * The number of fill bytes to make the length a 4-byte
279 * multiple is the low order 2-bits of the f_ctl.
280 * The fill itself will have been cleared by the frame
281 * allocation.
282 * After this, the length will be even, as expected by
283 * the transport.
284 */
285 fill = fr_len(fp) & 3;
286 if (fill) {
287 fill = 4 - fill;
288 /* TODO, this may be a problem with fragmented skb */
289 skb_put(fp_skb(fp), fill);
290 hton24(fh->fh_f_ctl, f_ctl | fill);
291 }
292 } else {
293 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
294 fr_eof(fp) = FC_EOF_N;
295 }
296
297 /* Initialize remaining fh fields from fc_fill_fc_hdr */
298 fh->fh_ox_id = htons(ep->oxid);
299 fh->fh_rx_id = htons(ep->rxid);
300 fh->fh_seq_id = ep->seq.id;
301 fh->fh_seq_cnt = htons(ep->seq.cnt);
302}
303
304/**
305 * fc_exch_release() - Decrement an exchange's reference count
306 * @ep: Exchange to be released
307 *
308 * If the reference count reaches zero and the exchange is complete,
309 * it is freed.
310 */
311static void fc_exch_release(struct fc_exch *ep)
312{
313 struct fc_exch_mgr *mp;
314
315 if (atomic_dec_and_test(&ep->ex_refcnt)) {
316 mp = ep->em;
317 if (ep->destructor)
318 ep->destructor(&ep->seq, ep->arg);
319 WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));
320 mempool_free(ep, mp->ep_pool);
321 }
322}
323
324/**
325 * fc_exch_timer_cancel() - cancel exch timer
326 * @ep: The exchange whose timer to be canceled
327 */
328static inline void fc_exch_timer_cancel(struct fc_exch *ep)
329{
330 if (cancel_delayed_work(&ep->timeout_work)) {
331 FC_EXCH_DBG(ep, "Exchange timer canceled\n");
332 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
333 }
334}
335
336/**
337 * fc_exch_timer_set_locked() - Start a timer for an exchange w/ the
338 * the exchange lock held
339 * @ep: The exchange whose timer will start
340 * @timer_msec: The timeout period
341 *
342 * Used for upper level protocols to time out the exchange.
343 * The timer is cancelled when it fires or when the exchange completes.
344 */
345static inline void fc_exch_timer_set_locked(struct fc_exch *ep,
346 unsigned int timer_msec)
347{
348 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
349 return;
350
351 FC_EXCH_DBG(ep, "Exchange timer armed : %d msecs\n", timer_msec);
352
353 fc_exch_hold(ep); /* hold for timer */
354 if (!queue_delayed_work(fc_exch_workqueue, &ep->timeout_work,
355 msecs_to_jiffies(timer_msec))) {
356 FC_EXCH_DBG(ep, "Exchange already queued\n");
357 fc_exch_release(ep);
358 }
359}
360
361/**
362 * fc_exch_timer_set() - Lock the exchange and set the timer
363 * @ep: The exchange whose timer will start
364 * @timer_msec: The timeout period
365 */
366static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec)
367{
368 spin_lock_bh(&ep->ex_lock);
369 fc_exch_timer_set_locked(ep, timer_msec);
370 spin_unlock_bh(&ep->ex_lock);
371}
372
373/**
374 * fc_exch_done_locked() - Complete an exchange with the exchange lock held
375 * @ep: The exchange that is complete
376 *
377 * Note: May sleep if invoked from outside a response handler.
378 */
379static int fc_exch_done_locked(struct fc_exch *ep)
380{
381 int rc = 1;
382
383 /*
384 * We must check for completion in case there are two threads
385 * tyring to complete this. But the rrq code will reuse the
386 * ep, and in that case we only clear the resp and set it as
387 * complete, so it can be reused by the timer to send the rrq.
388 */
389 if (ep->state & FC_EX_DONE)
390 return rc;
391 ep->esb_stat |= ESB_ST_COMPLETE;
392
393 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
394 ep->state |= FC_EX_DONE;
395 fc_exch_timer_cancel(ep);
396 rc = 0;
397 }
398 return rc;
399}
400
401static struct fc_exch fc_quarantine_exch;
402
403/**
404 * fc_exch_ptr_get() - Return an exchange from an exchange pool
405 * @pool: Exchange Pool to get an exchange from
406 * @index: Index of the exchange within the pool
407 *
408 * Use the index to get an exchange from within an exchange pool. exches
409 * will point to an array of exchange pointers. The index will select
410 * the exchange within the array.
411 */
412static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,
413 u16 index)
414{
415 struct fc_exch **exches = (struct fc_exch **)(pool + 1);
416 return exches[index];
417}
418
419/**
420 * fc_exch_ptr_set() - Assign an exchange to a slot in an exchange pool
421 * @pool: The pool to assign the exchange to
422 * @index: The index in the pool where the exchange will be assigned
423 * @ep: The exchange to assign to the pool
424 */
425static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
426 struct fc_exch *ep)
427{
428 ((struct fc_exch **)(pool + 1))[index] = ep;
429}
430
431/**
432 * fc_exch_delete() - Delete an exchange
433 * @ep: The exchange to be deleted
434 */
435static void fc_exch_delete(struct fc_exch *ep)
436{
437 struct fc_exch_pool *pool;
438 u16 index;
439
440 pool = ep->pool;
441 spin_lock_bh(&pool->lock);
442 WARN_ON(pool->total_exches <= 0);
443 pool->total_exches--;
444
445 /* update cache of free slot */
446 index = (ep->xid - ep->em->min_xid) >> fc_cpu_order;
447 if (!(ep->state & FC_EX_QUARANTINE)) {
448 if (pool->left == FC_XID_UNKNOWN)
449 pool->left = index;
450 else if (pool->right == FC_XID_UNKNOWN)
451 pool->right = index;
452 else
453 pool->next_index = index;
454 fc_exch_ptr_set(pool, index, NULL);
455 } else {
456 fc_exch_ptr_set(pool, index, &fc_quarantine_exch);
457 }
458 list_del(&ep->ex_list);
459 spin_unlock_bh(&pool->lock);
460 fc_exch_release(ep); /* drop hold for exch in mp */
461}
462
463static int fc_seq_send_locked(struct fc_lport *lport, struct fc_seq *sp,
464 struct fc_frame *fp)
465{
466 struct fc_exch *ep;
467 struct fc_frame_header *fh = fc_frame_header_get(fp);
468 int error = -ENXIO;
469 u32 f_ctl;
470 u8 fh_type = fh->fh_type;
471
472 ep = fc_seq_exch(sp);
473
474 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL)) {
475 fc_frame_free(fp);
476 goto out;
477 }
478
479 WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT));
480
481 f_ctl = ntoh24(fh->fh_f_ctl);
482 fc_exch_setup_hdr(ep, fp, f_ctl);
483 fr_encaps(fp) = ep->encaps;
484
485 /*
486 * update sequence count if this frame is carrying
487 * multiple FC frames when sequence offload is enabled
488 * by LLD.
489 */
490 if (fr_max_payload(fp))
491 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),
492 fr_max_payload(fp));
493 else
494 sp->cnt++;
495
496 /*
497 * Send the frame.
498 */
499 error = lport->tt.frame_send(lport, fp);
500
501 if (fh_type == FC_TYPE_BLS)
502 goto out;
503
504 /*
505 * Update the exchange and sequence flags,
506 * assuming all frames for the sequence have been sent.
507 * We can only be called to send once for each sequence.
508 */
509 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
510 if (f_ctl & FC_FC_SEQ_INIT)
511 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
512out:
513 return error;
514}
515
516/**
517 * fc_seq_send() - Send a frame using existing sequence/exchange pair
518 * @lport: The local port that the exchange will be sent on
519 * @sp: The sequence to be sent
520 * @fp: The frame to be sent on the exchange
521 *
522 * Note: The frame will be freed either by a direct call to fc_frame_free(fp)
523 * or indirectly by calling libfc_function_template.frame_send().
524 */
525int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp, struct fc_frame *fp)
526{
527 struct fc_exch *ep;
528 int error;
529 ep = fc_seq_exch(sp);
530 spin_lock_bh(&ep->ex_lock);
531 error = fc_seq_send_locked(lport, sp, fp);
532 spin_unlock_bh(&ep->ex_lock);
533 return error;
534}
535EXPORT_SYMBOL(fc_seq_send);
536
537/**
538 * fc_seq_alloc() - Allocate a sequence for a given exchange
539 * @ep: The exchange to allocate a new sequence for
540 * @seq_id: The sequence ID to be used
541 *
542 * We don't support multiple originated sequences on the same exchange.
543 * By implication, any previously originated sequence on this exchange
544 * is complete, and we reallocate the same sequence.
545 */
546static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
547{
548 struct fc_seq *sp;
549
550 sp = &ep->seq;
551 sp->ssb_stat = 0;
552 sp->cnt = 0;
553 sp->id = seq_id;
554 return sp;
555}
556
557/**
558 * fc_seq_start_next_locked() - Allocate a new sequence on the same
559 * exchange as the supplied sequence
560 * @sp: The sequence/exchange to get a new sequence for
561 */
562static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
563{
564 struct fc_exch *ep = fc_seq_exch(sp);
565
566 sp = fc_seq_alloc(ep, ep->seq_id++);
567 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
568 ep->f_ctl, sp->id);
569 return sp;
570}
571
572/**
573 * fc_seq_start_next() - Lock the exchange and get a new sequence
574 * for a given sequence/exchange pair
575 * @sp: The sequence/exchange to get a new exchange for
576 */
577struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
578{
579 struct fc_exch *ep = fc_seq_exch(sp);
580
581 spin_lock_bh(&ep->ex_lock);
582 sp = fc_seq_start_next_locked(sp);
583 spin_unlock_bh(&ep->ex_lock);
584
585 return sp;
586}
587EXPORT_SYMBOL(fc_seq_start_next);
588
589/*
590 * Set the response handler for the exchange associated with a sequence.
591 *
592 * Note: May sleep if invoked from outside a response handler.
593 */
594void fc_seq_set_resp(struct fc_seq *sp,
595 void (*resp)(struct fc_seq *, struct fc_frame *, void *),
596 void *arg)
597{
598 struct fc_exch *ep = fc_seq_exch(sp);
599 DEFINE_WAIT(wait);
600
601 spin_lock_bh(&ep->ex_lock);
602 while (ep->resp_active && ep->resp_task != current) {
603 prepare_to_wait(&ep->resp_wq, &wait, TASK_UNINTERRUPTIBLE);
604 spin_unlock_bh(&ep->ex_lock);
605
606 schedule();
607
608 spin_lock_bh(&ep->ex_lock);
609 }
610 finish_wait(&ep->resp_wq, &wait);
611 ep->resp = resp;
612 ep->arg = arg;
613 spin_unlock_bh(&ep->ex_lock);
614}
615EXPORT_SYMBOL(fc_seq_set_resp);
616
617/**
618 * fc_exch_abort_locked() - Abort an exchange
619 * @ep: The exchange to be aborted
620 * @timer_msec: The period of time to wait before aborting
621 *
622 * Abort an exchange and sequence. Generally called because of a
623 * exchange timeout or an abort from the upper layer.
624 *
625 * A timer_msec can be specified for abort timeout, if non-zero
626 * timer_msec value is specified then exchange resp handler
627 * will be called with timeout error if no response to abort.
628 *
629 * Locking notes: Called with exch lock held
630 *
631 * Return value: 0 on success else error code
632 */
633static int fc_exch_abort_locked(struct fc_exch *ep,
634 unsigned int timer_msec)
635{
636 struct fc_seq *sp;
637 struct fc_frame *fp;
638 int error;
639
640 FC_EXCH_DBG(ep, "exch: abort, time %d msecs\n", timer_msec);
641 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
642 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
643 FC_EXCH_DBG(ep, "exch: already completed esb %x state %x\n",
644 ep->esb_stat, ep->state);
645 return -ENXIO;
646 }
647
648 /*
649 * Send the abort on a new sequence if possible.
650 */
651 sp = fc_seq_start_next_locked(&ep->seq);
652 if (!sp)
653 return -ENOMEM;
654
655 if (timer_msec)
656 fc_exch_timer_set_locked(ep, timer_msec);
657
658 if (ep->sid) {
659 /*
660 * Send an abort for the sequence that timed out.
661 */
662 fp = fc_frame_alloc(ep->lp, 0);
663 if (fp) {
664 ep->esb_stat |= ESB_ST_SEQ_INIT;
665 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
666 FC_TYPE_BLS, FC_FC_END_SEQ |
667 FC_FC_SEQ_INIT, 0);
668 error = fc_seq_send_locked(ep->lp, sp, fp);
669 } else {
670 error = -ENOBUFS;
671 }
672 } else {
673 /*
674 * If not logged into the fabric, don't send ABTS but leave
675 * sequence active until next timeout.
676 */
677 error = 0;
678 }
679 ep->esb_stat |= ESB_ST_ABNORMAL;
680 return error;
681}
682
683/**
684 * fc_seq_exch_abort() - Abort an exchange and sequence
685 * @req_sp: The sequence to be aborted
686 * @timer_msec: The period of time to wait before aborting
687 *
688 * Generally called because of a timeout or an abort from the upper layer.
689 *
690 * Return value: 0 on success else error code
691 */
692int fc_seq_exch_abort(const struct fc_seq *req_sp, unsigned int timer_msec)
693{
694 struct fc_exch *ep;
695 int error;
696
697 ep = fc_seq_exch(req_sp);
698 spin_lock_bh(&ep->ex_lock);
699 error = fc_exch_abort_locked(ep, timer_msec);
700 spin_unlock_bh(&ep->ex_lock);
701 return error;
702}
703
704/**
705 * fc_invoke_resp() - invoke ep->resp()
706 * @ep: The exchange to be operated on
707 * @fp: The frame pointer to pass through to ->resp()
708 * @sp: The sequence pointer to pass through to ->resp()
709 *
710 * Notes:
711 * It is assumed that after initialization finished (this means the
712 * first unlock of ex_lock after fc_exch_alloc()) ep->resp and ep->arg are
713 * modified only via fc_seq_set_resp(). This guarantees that none of these
714 * two variables changes if ep->resp_active > 0.
715 *
716 * If an fc_seq_set_resp() call is busy modifying ep->resp and ep->arg when
717 * this function is invoked, the first spin_lock_bh() call in this function
718 * will wait until fc_seq_set_resp() has finished modifying these variables.
719 *
720 * Since fc_exch_done() invokes fc_seq_set_resp() it is guaranteed that that
721 * ep->resp() won't be invoked after fc_exch_done() has returned.
722 *
723 * The response handler itself may invoke fc_exch_done(), which will clear the
724 * ep->resp pointer.
725 *
726 * Return value:
727 * Returns true if and only if ep->resp has been invoked.
728 */
729static bool fc_invoke_resp(struct fc_exch *ep, struct fc_seq *sp,
730 struct fc_frame *fp)
731{
732 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
733 void *arg;
734 bool res = false;
735
736 spin_lock_bh(&ep->ex_lock);
737 ep->resp_active++;
738 if (ep->resp_task != current)
739 ep->resp_task = !ep->resp_task ? current : NULL;
740 resp = ep->resp;
741 arg = ep->arg;
742 spin_unlock_bh(&ep->ex_lock);
743
744 if (resp) {
745 resp(sp, fp, arg);
746 res = true;
747 }
748
749 spin_lock_bh(&ep->ex_lock);
750 if (--ep->resp_active == 0)
751 ep->resp_task = NULL;
752 spin_unlock_bh(&ep->ex_lock);
753
754 if (ep->resp_active == 0)
755 wake_up(&ep->resp_wq);
756
757 return res;
758}
759
760/**
761 * fc_exch_timeout() - Handle exchange timer expiration
762 * @work: The work_struct identifying the exchange that timed out
763 */
764static void fc_exch_timeout(struct work_struct *work)
765{
766 struct fc_exch *ep = container_of(work, struct fc_exch,
767 timeout_work.work);
768 struct fc_seq *sp = &ep->seq;
769 u32 e_stat;
770 int rc = 1;
771
772 FC_EXCH_DBG(ep, "Exchange timed out state %x\n", ep->state);
773
774 spin_lock_bh(&ep->ex_lock);
775 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
776 goto unlock;
777
778 e_stat = ep->esb_stat;
779 if (e_stat & ESB_ST_COMPLETE) {
780 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
781 spin_unlock_bh(&ep->ex_lock);
782 if (e_stat & ESB_ST_REC_QUAL)
783 fc_exch_rrq(ep);
784 goto done;
785 } else {
786 if (e_stat & ESB_ST_ABNORMAL)
787 rc = fc_exch_done_locked(ep);
788 spin_unlock_bh(&ep->ex_lock);
789 if (!rc)
790 fc_exch_delete(ep);
791 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_TIMEOUT));
792 fc_seq_set_resp(sp, NULL, ep->arg);
793 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
794 goto done;
795 }
796unlock:
797 spin_unlock_bh(&ep->ex_lock);
798done:
799 /*
800 * This release matches the hold taken when the timer was set.
801 */
802 fc_exch_release(ep);
803}
804
805/**
806 * fc_exch_em_alloc() - Allocate an exchange from a specified EM.
807 * @lport: The local port that the exchange is for
808 * @mp: The exchange manager that will allocate the exchange
809 *
810 * Returns pointer to allocated fc_exch with exch lock held.
811 */
812static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
813 struct fc_exch_mgr *mp)
814{
815 struct fc_exch *ep;
816 unsigned int cpu;
817 u16 index;
818 struct fc_exch_pool *pool;
819
820 /* allocate memory for exchange */
821 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);
822 if (!ep) {
823 atomic_inc(&mp->stats.no_free_exch);
824 goto out;
825 }
826 memset(ep, 0, sizeof(*ep));
827
828 cpu = raw_smp_processor_id();
829 pool = per_cpu_ptr(mp->pool, cpu);
830 spin_lock_bh(&pool->lock);
831
832 /* peek cache of free slot */
833 if (pool->left != FC_XID_UNKNOWN) {
834 if (!WARN_ON(fc_exch_ptr_get(pool, pool->left))) {
835 index = pool->left;
836 pool->left = FC_XID_UNKNOWN;
837 goto hit;
838 }
839 }
840 if (pool->right != FC_XID_UNKNOWN) {
841 if (!WARN_ON(fc_exch_ptr_get(pool, pool->right))) {
842 index = pool->right;
843 pool->right = FC_XID_UNKNOWN;
844 goto hit;
845 }
846 }
847
848 index = pool->next_index;
849 /* allocate new exch from pool */
850 while (fc_exch_ptr_get(pool, index)) {
851 index = index == mp->pool_max_index ? 0 : index + 1;
852 if (index == pool->next_index)
853 goto err;
854 }
855 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
856hit:
857 fc_exch_hold(ep); /* hold for exch in mp */
858 spin_lock_init(&ep->ex_lock);
859 /*
860 * Hold exch lock for caller to prevent fc_exch_reset()
861 * from releasing exch while fc_exch_alloc() caller is
862 * still working on exch.
863 */
864 spin_lock_bh(&ep->ex_lock);
865
866 fc_exch_ptr_set(pool, index, ep);
867 list_add_tail(&ep->ex_list, &pool->ex_list);
868 fc_seq_alloc(ep, ep->seq_id++);
869 pool->total_exches++;
870 spin_unlock_bh(&pool->lock);
871
872 /*
873 * update exchange
874 */
875 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
876 ep->em = mp;
877 ep->pool = pool;
878 ep->lp = lport;
879 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
880 ep->rxid = FC_XID_UNKNOWN;
881 ep->class = mp->class;
882 ep->resp_active = 0;
883 init_waitqueue_head(&ep->resp_wq);
884 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
885out:
886 return ep;
887err:
888 spin_unlock_bh(&pool->lock);
889 atomic_inc(&mp->stats.no_free_exch_xid);
890 mempool_free(ep, mp->ep_pool);
891 return NULL;
892}
893
894/**
895 * fc_exch_alloc() - Allocate an exchange from an EM on a
896 * local port's list of EMs.
897 * @lport: The local port that will own the exchange
898 * @fp: The FC frame that the exchange will be for
899 *
900 * This function walks the list of exchange manager(EM)
901 * anchors to select an EM for a new exchange allocation. The
902 * EM is selected when a NULL match function pointer is encountered
903 * or when a call to a match function returns true.
904 */
905static struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
906 struct fc_frame *fp)
907{
908 struct fc_exch_mgr_anchor *ema;
909 struct fc_exch *ep;
910
911 list_for_each_entry(ema, &lport->ema_list, ema_list) {
912 if (!ema->match || ema->match(fp)) {
913 ep = fc_exch_em_alloc(lport, ema->mp);
914 if (ep)
915 return ep;
916 }
917 }
918 return NULL;
919}
920
921/**
922 * fc_exch_find() - Lookup and hold an exchange
923 * @mp: The exchange manager to lookup the exchange from
924 * @xid: The XID of the exchange to look up
925 */
926static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
927{
928 struct fc_lport *lport = mp->lport;
929 struct fc_exch_pool *pool;
930 struct fc_exch *ep = NULL;
931 u16 cpu = xid & fc_cpu_mask;
932
933 if (xid == FC_XID_UNKNOWN)
934 return NULL;
935
936 if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
937 pr_err("host%u: lport %6.6x: xid %d invalid CPU %d\n:",
938 lport->host->host_no, lport->port_id, xid, cpu);
939 return NULL;
940 }
941
942 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
943 pool = per_cpu_ptr(mp->pool, cpu);
944 spin_lock_bh(&pool->lock);
945 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
946 if (ep == &fc_quarantine_exch) {
947 FC_LPORT_DBG(lport, "xid %x quarantined\n", xid);
948 ep = NULL;
949 }
950 if (ep) {
951 WARN_ON(ep->xid != xid);
952 fc_exch_hold(ep);
953 }
954 spin_unlock_bh(&pool->lock);
955 }
956 return ep;
957}
958
959
960/**
961 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and
962 * the memory allocated for the related objects may be freed.
963 * @sp: The sequence that has completed
964 *
965 * Note: May sleep if invoked from outside a response handler.
966 */
967void fc_exch_done(struct fc_seq *sp)
968{
969 struct fc_exch *ep = fc_seq_exch(sp);
970 int rc;
971
972 spin_lock_bh(&ep->ex_lock);
973 rc = fc_exch_done_locked(ep);
974 spin_unlock_bh(&ep->ex_lock);
975
976 fc_seq_set_resp(sp, NULL, ep->arg);
977 if (!rc)
978 fc_exch_delete(ep);
979}
980EXPORT_SYMBOL(fc_exch_done);
981
982/**
983 * fc_exch_resp() - Allocate a new exchange for a response frame
984 * @lport: The local port that the exchange was for
985 * @mp: The exchange manager to allocate the exchange from
986 * @fp: The response frame
987 *
988 * Sets the responder ID in the frame header.
989 */
990static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
991 struct fc_exch_mgr *mp,
992 struct fc_frame *fp)
993{
994 struct fc_exch *ep;
995 struct fc_frame_header *fh;
996
997 ep = fc_exch_alloc(lport, fp);
998 if (ep) {
999 ep->class = fc_frame_class(fp);
1000
1001 /*
1002 * Set EX_CTX indicating we're responding on this exchange.
1003 */
1004 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
1005 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
1006 fh = fc_frame_header_get(fp);
1007 ep->sid = ntoh24(fh->fh_d_id);
1008 ep->did = ntoh24(fh->fh_s_id);
1009 ep->oid = ep->did;
1010
1011 /*
1012 * Allocated exchange has placed the XID in the
1013 * originator field. Move it to the responder field,
1014 * and set the originator XID from the frame.
1015 */
1016 ep->rxid = ep->xid;
1017 ep->oxid = ntohs(fh->fh_ox_id);
1018 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
1019 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
1020 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
1021
1022 fc_exch_hold(ep); /* hold for caller */
1023 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
1024 }
1025 return ep;
1026}
1027
1028/**
1029 * fc_seq_lookup_recip() - Find a sequence where the other end
1030 * originated the sequence
1031 * @lport: The local port that the frame was sent to
1032 * @mp: The Exchange Manager to lookup the exchange from
1033 * @fp: The frame associated with the sequence we're looking for
1034 *
1035 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
1036 * on the ep that should be released by the caller.
1037 */
1038static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
1039 struct fc_exch_mgr *mp,
1040 struct fc_frame *fp)
1041{
1042 struct fc_frame_header *fh = fc_frame_header_get(fp);
1043 struct fc_exch *ep = NULL;
1044 struct fc_seq *sp = NULL;
1045 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
1046 u32 f_ctl;
1047 u16 xid;
1048
1049 f_ctl = ntoh24(fh->fh_f_ctl);
1050 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
1051
1052 /*
1053 * Lookup or create the exchange if we will be creating the sequence.
1054 */
1055 if (f_ctl & FC_FC_EX_CTX) {
1056 xid = ntohs(fh->fh_ox_id); /* we originated exch */
1057 ep = fc_exch_find(mp, xid);
1058 if (!ep) {
1059 atomic_inc(&mp->stats.xid_not_found);
1060 reject = FC_RJT_OX_ID;
1061 goto out;
1062 }
1063 if (ep->rxid == FC_XID_UNKNOWN)
1064 ep->rxid = ntohs(fh->fh_rx_id);
1065 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
1066 reject = FC_RJT_OX_ID;
1067 goto rel;
1068 }
1069 } else {
1070 xid = ntohs(fh->fh_rx_id); /* we are the responder */
1071
1072 /*
1073 * Special case for MDS issuing an ELS TEST with a
1074 * bad rxid of 0.
1075 * XXX take this out once we do the proper reject.
1076 */
1077 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
1078 fc_frame_payload_op(fp) == ELS_TEST) {
1079 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
1080 xid = FC_XID_UNKNOWN;
1081 }
1082
1083 /*
1084 * new sequence - find the exchange
1085 */
1086 ep = fc_exch_find(mp, xid);
1087 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
1088 if (ep) {
1089 atomic_inc(&mp->stats.xid_busy);
1090 reject = FC_RJT_RX_ID;
1091 goto rel;
1092 }
1093 ep = fc_exch_resp(lport, mp, fp);
1094 if (!ep) {
1095 reject = FC_RJT_EXCH_EST; /* XXX */
1096 goto out;
1097 }
1098 xid = ep->xid; /* get our XID */
1099 } else if (!ep) {
1100 atomic_inc(&mp->stats.xid_not_found);
1101 reject = FC_RJT_RX_ID; /* XID not found */
1102 goto out;
1103 }
1104 }
1105
1106 spin_lock_bh(&ep->ex_lock);
1107 /*
1108 * At this point, we have the exchange held.
1109 * Find or create the sequence.
1110 */
1111 if (fc_sof_is_init(fr_sof(fp))) {
1112 sp = &ep->seq;
1113 sp->ssb_stat |= SSB_ST_RESP;
1114 sp->id = fh->fh_seq_id;
1115 } else {
1116 sp = &ep->seq;
1117 if (sp->id != fh->fh_seq_id) {
1118 atomic_inc(&mp->stats.seq_not_found);
1119 if (f_ctl & FC_FC_END_SEQ) {
1120 /*
1121 * Update sequence_id based on incoming last
1122 * frame of sequence exchange. This is needed
1123 * for FC target where DDP has been used
1124 * on target where, stack is indicated only
1125 * about last frame's (payload _header) header.
1126 * Whereas "seq_id" which is part of
1127 * frame_header is allocated by initiator
1128 * which is totally different from "seq_id"
1129 * allocated when XFER_RDY was sent by target.
1130 * To avoid false -ve which results into not
1131 * sending RSP, hence write request on other
1132 * end never finishes.
1133 */
1134 sp->ssb_stat |= SSB_ST_RESP;
1135 sp->id = fh->fh_seq_id;
1136 } else {
1137 spin_unlock_bh(&ep->ex_lock);
1138
1139 /* sequence/exch should exist */
1140 reject = FC_RJT_SEQ_ID;
1141 goto rel;
1142 }
1143 }
1144 }
1145 WARN_ON(ep != fc_seq_exch(sp));
1146
1147 if (f_ctl & FC_FC_SEQ_INIT)
1148 ep->esb_stat |= ESB_ST_SEQ_INIT;
1149 spin_unlock_bh(&ep->ex_lock);
1150
1151 fr_seq(fp) = sp;
1152out:
1153 return reject;
1154rel:
1155 fc_exch_done(&ep->seq);
1156 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
1157 return reject;
1158}
1159
1160/**
1161 * fc_seq_lookup_orig() - Find a sequence where this end
1162 * originated the sequence
1163 * @mp: The Exchange Manager to lookup the exchange from
1164 * @fp: The frame associated with the sequence we're looking for
1165 *
1166 * Does not hold the sequence for the caller.
1167 */
1168static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
1169 struct fc_frame *fp)
1170{
1171 struct fc_frame_header *fh = fc_frame_header_get(fp);
1172 struct fc_exch *ep;
1173 struct fc_seq *sp = NULL;
1174 u32 f_ctl;
1175 u16 xid;
1176
1177 f_ctl = ntoh24(fh->fh_f_ctl);
1178 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
1179 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
1180 ep = fc_exch_find(mp, xid);
1181 if (!ep)
1182 return NULL;
1183 if (ep->seq.id == fh->fh_seq_id) {
1184 /*
1185 * Save the RX_ID if we didn't previously know it.
1186 */
1187 sp = &ep->seq;
1188 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
1189 ep->rxid == FC_XID_UNKNOWN) {
1190 ep->rxid = ntohs(fh->fh_rx_id);
1191 }
1192 }
1193 fc_exch_release(ep);
1194 return sp;
1195}
1196
1197/**
1198 * fc_exch_set_addr() - Set the source and destination IDs for an exchange
1199 * @ep: The exchange to set the addresses for
1200 * @orig_id: The originator's ID
1201 * @resp_id: The responder's ID
1202 *
1203 * Note this must be done before the first sequence of the exchange is sent.
1204 */
1205static void fc_exch_set_addr(struct fc_exch *ep,
1206 u32 orig_id, u32 resp_id)
1207{
1208 ep->oid = orig_id;
1209 if (ep->esb_stat & ESB_ST_RESP) {
1210 ep->sid = resp_id;
1211 ep->did = orig_id;
1212 } else {
1213 ep->sid = orig_id;
1214 ep->did = resp_id;
1215 }
1216}
1217
1218/**
1219 * fc_seq_els_rsp_send() - Send an ELS response using information from
1220 * the existing sequence/exchange.
1221 * @fp: The received frame
1222 * @els_cmd: The ELS command to be sent
1223 * @els_data: The ELS data to be sent
1224 *
1225 * The received frame is not freed.
1226 */
1227void fc_seq_els_rsp_send(struct fc_frame *fp, enum fc_els_cmd els_cmd,
1228 struct fc_seq_els_data *els_data)
1229{
1230 switch (els_cmd) {
1231 case ELS_LS_RJT:
1232 fc_seq_ls_rjt(fp, els_data->reason, els_data->explan);
1233 break;
1234 case ELS_LS_ACC:
1235 fc_seq_ls_acc(fp);
1236 break;
1237 case ELS_RRQ:
1238 fc_exch_els_rrq(fp);
1239 break;
1240 case ELS_REC:
1241 fc_exch_els_rec(fp);
1242 break;
1243 default:
1244 FC_LPORT_DBG(fr_dev(fp), "Invalid ELS CMD:%x\n", els_cmd);
1245 }
1246}
1247EXPORT_SYMBOL_GPL(fc_seq_els_rsp_send);
1248
1249/**
1250 * fc_seq_send_last() - Send a sequence that is the last in the exchange
1251 * @sp: The sequence that is to be sent
1252 * @fp: The frame that will be sent on the sequence
1253 * @rctl: The R_CTL information to be sent
1254 * @fh_type: The frame header type
1255 */
1256static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
1257 enum fc_rctl rctl, enum fc_fh_type fh_type)
1258{
1259 u32 f_ctl;
1260 struct fc_exch *ep = fc_seq_exch(sp);
1261
1262 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
1263 f_ctl |= ep->f_ctl;
1264 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
1265 fc_seq_send_locked(ep->lp, sp, fp);
1266}
1267
1268/**
1269 * fc_seq_send_ack() - Send an acknowledgement that we've received a frame
1270 * @sp: The sequence to send the ACK on
1271 * @rx_fp: The received frame that is being acknoledged
1272 *
1273 * Send ACK_1 (or equiv.) indicating we received something.
1274 */
1275static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
1276{
1277 struct fc_frame *fp;
1278 struct fc_frame_header *rx_fh;
1279 struct fc_frame_header *fh;
1280 struct fc_exch *ep = fc_seq_exch(sp);
1281 struct fc_lport *lport = ep->lp;
1282 unsigned int f_ctl;
1283
1284 /*
1285 * Don't send ACKs for class 3.
1286 */
1287 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
1288 fp = fc_frame_alloc(lport, 0);
1289 if (!fp) {
1290 FC_EXCH_DBG(ep, "Drop ACK request, out of memory\n");
1291 return;
1292 }
1293
1294 fh = fc_frame_header_get(fp);
1295 fh->fh_r_ctl = FC_RCTL_ACK_1;
1296 fh->fh_type = FC_TYPE_BLS;
1297
1298 /*
1299 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1300 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1301 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1302 * Last ACK uses bits 7-6 (continue sequence),
1303 * bits 5-4 are meaningful (what kind of ACK to use).
1304 */
1305 rx_fh = fc_frame_header_get(rx_fp);
1306 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1307 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1308 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
1309 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
1310 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1311 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1312 hton24(fh->fh_f_ctl, f_ctl);
1313
1314 fc_exch_setup_hdr(ep, fp, f_ctl);
1315 fh->fh_seq_id = rx_fh->fh_seq_id;
1316 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1317 fh->fh_parm_offset = htonl(1); /* ack single frame */
1318
1319 fr_sof(fp) = fr_sof(rx_fp);
1320 if (f_ctl & FC_FC_END_SEQ)
1321 fr_eof(fp) = FC_EOF_T;
1322 else
1323 fr_eof(fp) = FC_EOF_N;
1324
1325 lport->tt.frame_send(lport, fp);
1326 }
1327}
1328
1329/**
1330 * fc_exch_send_ba_rjt() - Send BLS Reject
1331 * @rx_fp: The frame being rejected
1332 * @reason: The reason the frame is being rejected
1333 * @explan: The explanation for the rejection
1334 *
1335 * This is for rejecting BA_ABTS only.
1336 */
1337static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
1338 enum fc_ba_rjt_reason reason,
1339 enum fc_ba_rjt_explan explan)
1340{
1341 struct fc_frame *fp;
1342 struct fc_frame_header *rx_fh;
1343 struct fc_frame_header *fh;
1344 struct fc_ba_rjt *rp;
1345 struct fc_seq *sp;
1346 struct fc_lport *lport;
1347 unsigned int f_ctl;
1348
1349 lport = fr_dev(rx_fp);
1350 sp = fr_seq(rx_fp);
1351 fp = fc_frame_alloc(lport, sizeof(*rp));
1352 if (!fp) {
1353 FC_EXCH_DBG(fc_seq_exch(sp),
1354 "Drop BA_RJT request, out of memory\n");
1355 return;
1356 }
1357 fh = fc_frame_header_get(fp);
1358 rx_fh = fc_frame_header_get(rx_fp);
1359
1360 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1361
1362 rp = fc_frame_payload_get(fp, sizeof(*rp));
1363 rp->br_reason = reason;
1364 rp->br_explan = explan;
1365
1366 /*
1367 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1368 */
1369 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1370 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1371 fh->fh_ox_id = rx_fh->fh_ox_id;
1372 fh->fh_rx_id = rx_fh->fh_rx_id;
1373 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1374 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1375 fh->fh_type = FC_TYPE_BLS;
1376
1377 /*
1378 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1379 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1380 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1381 * Last ACK uses bits 7-6 (continue sequence),
1382 * bits 5-4 are meaningful (what kind of ACK to use).
1383 * Always set LAST_SEQ, END_SEQ.
1384 */
1385 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1386 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1387 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1388 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1389 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1390 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1391 f_ctl &= ~FC_FC_FIRST_SEQ;
1392 hton24(fh->fh_f_ctl, f_ctl);
1393
1394 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1395 fr_eof(fp) = FC_EOF_T;
1396 if (fc_sof_needs_ack(fr_sof(fp)))
1397 fr_eof(fp) = FC_EOF_N;
1398
1399 lport->tt.frame_send(lport, fp);
1400}
1401
1402/**
1403 * fc_exch_recv_abts() - Handle an incoming ABTS
1404 * @ep: The exchange the abort was on
1405 * @rx_fp: The ABTS frame
1406 *
1407 * This would be for target mode usually, but could be due to lost
1408 * FCP transfer ready, confirm or RRQ. We always handle this as an
1409 * exchange abort, ignoring the parameter.
1410 */
1411static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1412{
1413 struct fc_frame *fp;
1414 struct fc_ba_acc *ap;
1415 struct fc_frame_header *fh;
1416 struct fc_seq *sp;
1417
1418 if (!ep)
1419 goto reject;
1420
1421 FC_EXCH_DBG(ep, "exch: ABTS received\n");
1422 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1423 if (!fp) {
1424 FC_EXCH_DBG(ep, "Drop ABTS request, out of memory\n");
1425 goto free;
1426 }
1427
1428 spin_lock_bh(&ep->ex_lock);
1429 if (ep->esb_stat & ESB_ST_COMPLETE) {
1430 spin_unlock_bh(&ep->ex_lock);
1431 FC_EXCH_DBG(ep, "exch: ABTS rejected, exchange complete\n");
1432 fc_frame_free(fp);
1433 goto reject;
1434 }
1435 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
1436 ep->esb_stat |= ESB_ST_REC_QUAL;
1437 fc_exch_hold(ep); /* hold for REC_QUAL */
1438 }
1439 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1440 fh = fc_frame_header_get(fp);
1441 ap = fc_frame_payload_get(fp, sizeof(*ap));
1442 memset(ap, 0, sizeof(*ap));
1443 sp = &ep->seq;
1444 ap->ba_high_seq_cnt = htons(0xffff);
1445 if (sp->ssb_stat & SSB_ST_RESP) {
1446 ap->ba_seq_id = sp->id;
1447 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1448 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1449 ap->ba_low_seq_cnt = htons(sp->cnt);
1450 }
1451 sp = fc_seq_start_next_locked(sp);
1452 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1453 ep->esb_stat |= ESB_ST_ABNORMAL;
1454 spin_unlock_bh(&ep->ex_lock);
1455
1456free:
1457 fc_frame_free(rx_fp);
1458 return;
1459
1460reject:
1461 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1462 goto free;
1463}
1464
1465/**
1466 * fc_seq_assign() - Assign exchange and sequence for incoming request
1467 * @lport: The local port that received the request
1468 * @fp: The request frame
1469 *
1470 * On success, the sequence pointer will be returned and also in fr_seq(@fp).
1471 * A reference will be held on the exchange/sequence for the caller, which
1472 * must call fc_seq_release().
1473 */
1474struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)
1475{
1476 struct fc_exch_mgr_anchor *ema;
1477
1478 WARN_ON(lport != fr_dev(fp));
1479 WARN_ON(fr_seq(fp));
1480 fr_seq(fp) = NULL;
1481
1482 list_for_each_entry(ema, &lport->ema_list, ema_list)
1483 if ((!ema->match || ema->match(fp)) &&
1484 fc_seq_lookup_recip(lport, ema->mp, fp) == FC_RJT_NONE)
1485 break;
1486 return fr_seq(fp);
1487}
1488EXPORT_SYMBOL(fc_seq_assign);
1489
1490/**
1491 * fc_seq_release() - Release the hold
1492 * @sp: The sequence.
1493 */
1494void fc_seq_release(struct fc_seq *sp)
1495{
1496 fc_exch_release(fc_seq_exch(sp));
1497}
1498EXPORT_SYMBOL(fc_seq_release);
1499
1500/**
1501 * fc_exch_recv_req() - Handler for an incoming request
1502 * @lport: The local port that received the request
1503 * @mp: The EM that the exchange is on
1504 * @fp: The request frame
1505 *
1506 * This is used when the other end is originating the exchange
1507 * and the sequence.
1508 */
1509static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp,
1510 struct fc_frame *fp)
1511{
1512 struct fc_frame_header *fh = fc_frame_header_get(fp);
1513 struct fc_seq *sp = NULL;
1514 struct fc_exch *ep = NULL;
1515 enum fc_pf_rjt_reason reject;
1516
1517 /* We can have the wrong fc_lport at this point with NPIV, which is a
1518 * problem now that we know a new exchange needs to be allocated
1519 */
1520 lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id));
1521 if (!lport) {
1522 fc_frame_free(fp);
1523 return;
1524 }
1525 fr_dev(fp) = lport;
1526
1527 BUG_ON(fr_seq(fp)); /* XXX remove later */
1528
1529 /*
1530 * If the RX_ID is 0xffff, don't allocate an exchange.
1531 * The upper-level protocol may request one later, if needed.
1532 */
1533 if (fh->fh_rx_id == htons(FC_XID_UNKNOWN))
1534 return fc_lport_recv(lport, fp);
1535
1536 reject = fc_seq_lookup_recip(lport, mp, fp);
1537 if (reject == FC_RJT_NONE) {
1538 sp = fr_seq(fp); /* sequence will be held */
1539 ep = fc_seq_exch(sp);
1540 fc_seq_send_ack(sp, fp);
1541 ep->encaps = fr_encaps(fp);
1542
1543 /*
1544 * Call the receive function.
1545 *
1546 * The receive function may allocate a new sequence
1547 * over the old one, so we shouldn't change the
1548 * sequence after this.
1549 *
1550 * The frame will be freed by the receive function.
1551 * If new exch resp handler is valid then call that
1552 * first.
1553 */
1554 if (!fc_invoke_resp(ep, sp, fp))
1555 fc_lport_recv(lport, fp);
1556 fc_exch_release(ep); /* release from lookup */
1557 } else {
1558 FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n",
1559 reject);
1560 fc_frame_free(fp);
1561 }
1562}
1563
1564/**
1565 * fc_exch_recv_seq_resp() - Handler for an incoming response where the other
1566 * end is the originator of the sequence that is a
1567 * response to our initial exchange
1568 * @mp: The EM that the exchange is on
1569 * @fp: The response frame
1570 */
1571static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1572{
1573 struct fc_frame_header *fh = fc_frame_header_get(fp);
1574 struct fc_seq *sp;
1575 struct fc_exch *ep;
1576 enum fc_sof sof;
1577 u32 f_ctl;
1578 int rc;
1579
1580 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1581 if (!ep) {
1582 atomic_inc(&mp->stats.xid_not_found);
1583 goto out;
1584 }
1585 if (ep->esb_stat & ESB_ST_COMPLETE) {
1586 atomic_inc(&mp->stats.xid_not_found);
1587 goto rel;
1588 }
1589 if (ep->rxid == FC_XID_UNKNOWN)
1590 ep->rxid = ntohs(fh->fh_rx_id);
1591 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1592 atomic_inc(&mp->stats.xid_not_found);
1593 goto rel;
1594 }
1595 if (ep->did != ntoh24(fh->fh_s_id) &&
1596 ep->did != FC_FID_FLOGI) {
1597 atomic_inc(&mp->stats.xid_not_found);
1598 goto rel;
1599 }
1600 sof = fr_sof(fp);
1601 sp = &ep->seq;
1602 if (fc_sof_is_init(sof)) {
1603 sp->ssb_stat |= SSB_ST_RESP;
1604 sp->id = fh->fh_seq_id;
1605 }
1606
1607 f_ctl = ntoh24(fh->fh_f_ctl);
1608 fr_seq(fp) = sp;
1609
1610 spin_lock_bh(&ep->ex_lock);
1611 if (f_ctl & FC_FC_SEQ_INIT)
1612 ep->esb_stat |= ESB_ST_SEQ_INIT;
1613 spin_unlock_bh(&ep->ex_lock);
1614
1615 if (fc_sof_needs_ack(sof))
1616 fc_seq_send_ack(sp, fp);
1617
1618 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1619 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1620 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1621 spin_lock_bh(&ep->ex_lock);
1622 rc = fc_exch_done_locked(ep);
1623 WARN_ON(fc_seq_exch(sp) != ep);
1624 spin_unlock_bh(&ep->ex_lock);
1625 if (!rc) {
1626 fc_exch_delete(ep);
1627 } else {
1628 FC_EXCH_DBG(ep, "ep is completed already,"
1629 "hence skip calling the resp\n");
1630 goto skip_resp;
1631 }
1632 }
1633
1634 /*
1635 * Call the receive function.
1636 * The sequence is held (has a refcnt) for us,
1637 * but not for the receive function.
1638 *
1639 * The receive function may allocate a new sequence
1640 * over the old one, so we shouldn't change the
1641 * sequence after this.
1642 *
1643 * The frame will be freed by the receive function.
1644 * If new exch resp handler is valid then call that
1645 * first.
1646 */
1647 if (!fc_invoke_resp(ep, sp, fp))
1648 fc_frame_free(fp);
1649
1650skip_resp:
1651 fc_exch_release(ep);
1652 return;
1653rel:
1654 fc_exch_release(ep);
1655out:
1656 fc_frame_free(fp);
1657}
1658
1659/**
1660 * fc_exch_recv_resp() - Handler for a sequence where other end is
1661 * responding to our sequence
1662 * @mp: The EM that the exchange is on
1663 * @fp: The response frame
1664 */
1665static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1666{
1667 struct fc_seq *sp;
1668
1669 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1670
1671 if (!sp)
1672 atomic_inc(&mp->stats.xid_not_found);
1673 else
1674 atomic_inc(&mp->stats.non_bls_resp);
1675
1676 fc_frame_free(fp);
1677}
1678
1679/**
1680 * fc_exch_abts_resp() - Handler for a response to an ABT
1681 * @ep: The exchange that the frame is on
1682 * @fp: The response frame
1683 *
1684 * This response would be to an ABTS cancelling an exchange or sequence.
1685 * The response can be either BA_ACC or BA_RJT
1686 */
1687static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1688{
1689 struct fc_frame_header *fh;
1690 struct fc_ba_acc *ap;
1691 struct fc_seq *sp;
1692 u16 low;
1693 u16 high;
1694 int rc = 1, has_rec = 0;
1695
1696 fh = fc_frame_header_get(fp);
1697 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1698 fc_exch_rctl_name(fh->fh_r_ctl));
1699
1700 if (cancel_delayed_work_sync(&ep->timeout_work)) {
1701 FC_EXCH_DBG(ep, "Exchange timer canceled due to ABTS response\n");
1702 fc_exch_release(ep); /* release from pending timer hold */
1703 return;
1704 }
1705
1706 spin_lock_bh(&ep->ex_lock);
1707 switch (fh->fh_r_ctl) {
1708 case FC_RCTL_BA_ACC:
1709 ap = fc_frame_payload_get(fp, sizeof(*ap));
1710 if (!ap)
1711 break;
1712
1713 /*
1714 * Decide whether to establish a Recovery Qualifier.
1715 * We do this if there is a non-empty SEQ_CNT range and
1716 * SEQ_ID is the same as the one we aborted.
1717 */
1718 low = ntohs(ap->ba_low_seq_cnt);
1719 high = ntohs(ap->ba_high_seq_cnt);
1720 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1721 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1722 ap->ba_seq_id == ep->seq_id) && low != high) {
1723 ep->esb_stat |= ESB_ST_REC_QUAL;
1724 fc_exch_hold(ep); /* hold for recovery qualifier */
1725 has_rec = 1;
1726 }
1727 break;
1728 case FC_RCTL_BA_RJT:
1729 break;
1730 default:
1731 break;
1732 }
1733
1734 /* do we need to do some other checks here. Can we reuse more of
1735 * fc_exch_recv_seq_resp
1736 */
1737 sp = &ep->seq;
1738 /*
1739 * do we want to check END_SEQ as well as LAST_SEQ here?
1740 */
1741 if (ep->fh_type != FC_TYPE_FCP &&
1742 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1743 rc = fc_exch_done_locked(ep);
1744 spin_unlock_bh(&ep->ex_lock);
1745
1746 fc_exch_hold(ep);
1747 if (!rc)
1748 fc_exch_delete(ep);
1749 if (!fc_invoke_resp(ep, sp, fp))
1750 fc_frame_free(fp);
1751 if (has_rec)
1752 fc_exch_timer_set(ep, ep->r_a_tov);
1753 fc_exch_release(ep);
1754}
1755
1756/**
1757 * fc_exch_recv_bls() - Handler for a BLS sequence
1758 * @mp: The EM that the exchange is on
1759 * @fp: The request frame
1760 *
1761 * The BLS frame is always a sequence initiated by the remote side.
1762 * We may be either the originator or recipient of the exchange.
1763 */
1764static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1765{
1766 struct fc_frame_header *fh;
1767 struct fc_exch *ep;
1768 u32 f_ctl;
1769
1770 fh = fc_frame_header_get(fp);
1771 f_ctl = ntoh24(fh->fh_f_ctl);
1772 fr_seq(fp) = NULL;
1773
1774 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1775 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1776 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1777 spin_lock_bh(&ep->ex_lock);
1778 ep->esb_stat |= ESB_ST_SEQ_INIT;
1779 spin_unlock_bh(&ep->ex_lock);
1780 }
1781 if (f_ctl & FC_FC_SEQ_CTX) {
1782 /*
1783 * A response to a sequence we initiated.
1784 * This should only be ACKs for class 2 or F.
1785 */
1786 switch (fh->fh_r_ctl) {
1787 case FC_RCTL_ACK_1:
1788 case FC_RCTL_ACK_0:
1789 break;
1790 default:
1791 if (ep)
1792 FC_EXCH_DBG(ep, "BLS rctl %x - %s received\n",
1793 fh->fh_r_ctl,
1794 fc_exch_rctl_name(fh->fh_r_ctl));
1795 break;
1796 }
1797 fc_frame_free(fp);
1798 } else {
1799 switch (fh->fh_r_ctl) {
1800 case FC_RCTL_BA_RJT:
1801 case FC_RCTL_BA_ACC:
1802 if (ep)
1803 fc_exch_abts_resp(ep, fp);
1804 else
1805 fc_frame_free(fp);
1806 break;
1807 case FC_RCTL_BA_ABTS:
1808 if (ep)
1809 fc_exch_recv_abts(ep, fp);
1810 else
1811 fc_frame_free(fp);
1812 break;
1813 default: /* ignore junk */
1814 fc_frame_free(fp);
1815 break;
1816 }
1817 }
1818 if (ep)
1819 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1820}
1821
1822/**
1823 * fc_seq_ls_acc() - Accept sequence with LS_ACC
1824 * @rx_fp: The received frame, not freed here.
1825 *
1826 * If this fails due to allocation or transmit congestion, assume the
1827 * originator will repeat the sequence.
1828 */
1829static void fc_seq_ls_acc(struct fc_frame *rx_fp)
1830{
1831 struct fc_lport *lport;
1832 struct fc_els_ls_acc *acc;
1833 struct fc_frame *fp;
1834 struct fc_seq *sp;
1835
1836 lport = fr_dev(rx_fp);
1837 sp = fr_seq(rx_fp);
1838 fp = fc_frame_alloc(lport, sizeof(*acc));
1839 if (!fp) {
1840 FC_EXCH_DBG(fc_seq_exch(sp),
1841 "exch: drop LS_ACC, out of memory\n");
1842 return;
1843 }
1844 acc = fc_frame_payload_get(fp, sizeof(*acc));
1845 memset(acc, 0, sizeof(*acc));
1846 acc->la_cmd = ELS_LS_ACC;
1847 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1848 lport->tt.frame_send(lport, fp);
1849}
1850
1851/**
1852 * fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT
1853 * @rx_fp: The received frame, not freed here.
1854 * @reason: The reason the sequence is being rejected
1855 * @explan: The explanation for the rejection
1856 *
1857 * If this fails due to allocation or transmit congestion, assume the
1858 * originator will repeat the sequence.
1859 */
1860static void fc_seq_ls_rjt(struct fc_frame *rx_fp, enum fc_els_rjt_reason reason,
1861 enum fc_els_rjt_explan explan)
1862{
1863 struct fc_lport *lport;
1864 struct fc_els_ls_rjt *rjt;
1865 struct fc_frame *fp;
1866 struct fc_seq *sp;
1867
1868 lport = fr_dev(rx_fp);
1869 sp = fr_seq(rx_fp);
1870 fp = fc_frame_alloc(lport, sizeof(*rjt));
1871 if (!fp) {
1872 FC_EXCH_DBG(fc_seq_exch(sp),
1873 "exch: drop LS_ACC, out of memory\n");
1874 return;
1875 }
1876 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1877 memset(rjt, 0, sizeof(*rjt));
1878 rjt->er_cmd = ELS_LS_RJT;
1879 rjt->er_reason = reason;
1880 rjt->er_explan = explan;
1881 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1882 lport->tt.frame_send(lport, fp);
1883}
1884
1885/**
1886 * fc_exch_reset() - Reset an exchange
1887 * @ep: The exchange to be reset
1888 *
1889 * Note: May sleep if invoked from outside a response handler.
1890 */
1891static void fc_exch_reset(struct fc_exch *ep)
1892{
1893 struct fc_seq *sp;
1894 int rc = 1;
1895
1896 spin_lock_bh(&ep->ex_lock);
1897 ep->state |= FC_EX_RST_CLEANUP;
1898 fc_exch_timer_cancel(ep);
1899 if (ep->esb_stat & ESB_ST_REC_QUAL)
1900 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1901 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1902 sp = &ep->seq;
1903 rc = fc_exch_done_locked(ep);
1904 spin_unlock_bh(&ep->ex_lock);
1905
1906 fc_exch_hold(ep);
1907
1908 if (!rc) {
1909 fc_exch_delete(ep);
1910 } else {
1911 FC_EXCH_DBG(ep, "ep is completed already,"
1912 "hence skip calling the resp\n");
1913 goto skip_resp;
1914 }
1915
1916 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_CLOSED));
1917skip_resp:
1918 fc_seq_set_resp(sp, NULL, ep->arg);
1919 fc_exch_release(ep);
1920}
1921
1922/**
1923 * fc_exch_pool_reset() - Reset a per cpu exchange pool
1924 * @lport: The local port that the exchange pool is on
1925 * @pool: The exchange pool to be reset
1926 * @sid: The source ID
1927 * @did: The destination ID
1928 *
1929 * Resets a per cpu exches pool, releasing all of its sequences
1930 * and exchanges. If sid is non-zero then reset only exchanges
1931 * we sourced from the local port's FID. If did is non-zero then
1932 * only reset exchanges destined for the local port's FID.
1933 */
1934static void fc_exch_pool_reset(struct fc_lport *lport,
1935 struct fc_exch_pool *pool,
1936 u32 sid, u32 did)
1937{
1938 struct fc_exch *ep;
1939 struct fc_exch *next;
1940
1941 spin_lock_bh(&pool->lock);
1942restart:
1943 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1944 if ((lport == ep->lp) &&
1945 (sid == 0 || sid == ep->sid) &&
1946 (did == 0 || did == ep->did)) {
1947 fc_exch_hold(ep);
1948 spin_unlock_bh(&pool->lock);
1949
1950 fc_exch_reset(ep);
1951
1952 fc_exch_release(ep);
1953 spin_lock_bh(&pool->lock);
1954
1955 /*
1956 * must restart loop incase while lock
1957 * was down multiple eps were released.
1958 */
1959 goto restart;
1960 }
1961 }
1962 pool->next_index = 0;
1963 pool->left = FC_XID_UNKNOWN;
1964 pool->right = FC_XID_UNKNOWN;
1965 spin_unlock_bh(&pool->lock);
1966}
1967
1968/**
1969 * fc_exch_mgr_reset() - Reset all EMs of a local port
1970 * @lport: The local port whose EMs are to be reset
1971 * @sid: The source ID
1972 * @did: The destination ID
1973 *
1974 * Reset all EMs associated with a given local port. Release all
1975 * sequences and exchanges. If sid is non-zero then reset only the
1976 * exchanges sent from the local port's FID. If did is non-zero then
1977 * reset only exchanges destined for the local port's FID.
1978 */
1979void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1980{
1981 struct fc_exch_mgr_anchor *ema;
1982 unsigned int cpu;
1983
1984 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1985 for_each_possible_cpu(cpu)
1986 fc_exch_pool_reset(lport,
1987 per_cpu_ptr(ema->mp->pool, cpu),
1988 sid, did);
1989 }
1990}
1991EXPORT_SYMBOL(fc_exch_mgr_reset);
1992
1993/**
1994 * fc_exch_lookup() - find an exchange
1995 * @lport: The local port
1996 * @xid: The exchange ID
1997 *
1998 * Returns exchange pointer with hold for caller, or NULL if not found.
1999 */
2000static struct fc_exch *fc_exch_lookup(struct fc_lport *lport, u32 xid)
2001{
2002 struct fc_exch_mgr_anchor *ema;
2003
2004 list_for_each_entry(ema, &lport->ema_list, ema_list)
2005 if (ema->mp->min_xid <= xid && xid <= ema->mp->max_xid)
2006 return fc_exch_find(ema->mp, xid);
2007 return NULL;
2008}
2009
2010/**
2011 * fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests
2012 * @rfp: The REC frame, not freed here.
2013 *
2014 * Note that the requesting port may be different than the S_ID in the request.
2015 */
2016static void fc_exch_els_rec(struct fc_frame *rfp)
2017{
2018 struct fc_lport *lport;
2019 struct fc_frame *fp;
2020 struct fc_exch *ep;
2021 struct fc_els_rec *rp;
2022 struct fc_els_rec_acc *acc;
2023 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
2024 enum fc_els_rjt_explan explan;
2025 u32 sid;
2026 u16 xid, rxid, oxid;
2027
2028 lport = fr_dev(rfp);
2029 rp = fc_frame_payload_get(rfp, sizeof(*rp));
2030 explan = ELS_EXPL_INV_LEN;
2031 if (!rp)
2032 goto reject;
2033 sid = ntoh24(rp->rec_s_id);
2034 rxid = ntohs(rp->rec_rx_id);
2035 oxid = ntohs(rp->rec_ox_id);
2036
2037 explan = ELS_EXPL_OXID_RXID;
2038 if (sid == fc_host_port_id(lport->host))
2039 xid = oxid;
2040 else
2041 xid = rxid;
2042 if (xid == FC_XID_UNKNOWN) {
2043 FC_LPORT_DBG(lport,
2044 "REC request from %x: invalid rxid %x oxid %x\n",
2045 sid, rxid, oxid);
2046 goto reject;
2047 }
2048 ep = fc_exch_lookup(lport, xid);
2049 if (!ep) {
2050 FC_LPORT_DBG(lport,
2051 "REC request from %x: rxid %x oxid %x not found\n",
2052 sid, rxid, oxid);
2053 goto reject;
2054 }
2055 FC_EXCH_DBG(ep, "REC request from %x: rxid %x oxid %x\n",
2056 sid, rxid, oxid);
2057 if (ep->oid != sid || oxid != ep->oxid)
2058 goto rel;
2059 if (rxid != FC_XID_UNKNOWN && rxid != ep->rxid)
2060 goto rel;
2061 fp = fc_frame_alloc(lport, sizeof(*acc));
2062 if (!fp) {
2063 FC_EXCH_DBG(ep, "Drop REC request, out of memory\n");
2064 goto out;
2065 }
2066
2067 acc = fc_frame_payload_get(fp, sizeof(*acc));
2068 memset(acc, 0, sizeof(*acc));
2069 acc->reca_cmd = ELS_LS_ACC;
2070 acc->reca_ox_id = rp->rec_ox_id;
2071 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
2072 acc->reca_rx_id = htons(ep->rxid);
2073 if (ep->sid == ep->oid)
2074 hton24(acc->reca_rfid, ep->did);
2075 else
2076 hton24(acc->reca_rfid, ep->sid);
2077 acc->reca_fc4value = htonl(ep->seq.rec_data);
2078 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
2079 ESB_ST_SEQ_INIT |
2080 ESB_ST_COMPLETE));
2081 fc_fill_reply_hdr(fp, rfp, FC_RCTL_ELS_REP, 0);
2082 lport->tt.frame_send(lport, fp);
2083out:
2084 fc_exch_release(ep);
2085 return;
2086
2087rel:
2088 fc_exch_release(ep);
2089reject:
2090 fc_seq_ls_rjt(rfp, reason, explan);
2091}
2092
2093/**
2094 * fc_exch_rrq_resp() - Handler for RRQ responses
2095 * @sp: The sequence that the RRQ is on
2096 * @fp: The RRQ frame
2097 * @arg: The exchange that the RRQ is on
2098 *
2099 * TODO: fix error handler.
2100 */
2101static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
2102{
2103 struct fc_exch *aborted_ep = arg;
2104 unsigned int op;
2105
2106 if (IS_ERR(fp)) {
2107 int err = PTR_ERR(fp);
2108
2109 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
2110 goto cleanup;
2111 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
2112 "frame error %d\n", err);
2113 return;
2114 }
2115
2116 op = fc_frame_payload_op(fp);
2117 fc_frame_free(fp);
2118
2119 switch (op) {
2120 case ELS_LS_RJT:
2121 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ\n");
2122 fallthrough;
2123 case ELS_LS_ACC:
2124 goto cleanup;
2125 default:
2126 FC_EXCH_DBG(aborted_ep, "unexpected response op %x for RRQ\n",
2127 op);
2128 return;
2129 }
2130
2131cleanup:
2132 fc_exch_done(&aborted_ep->seq);
2133 /* drop hold for rec qual */
2134 fc_exch_release(aborted_ep);
2135}
2136
2137
2138/**
2139 * fc_exch_seq_send() - Send a frame using a new exchange and sequence
2140 * @lport: The local port to send the frame on
2141 * @fp: The frame to be sent
2142 * @resp: The response handler for this request
2143 * @destructor: The destructor for the exchange
2144 * @arg: The argument to be passed to the response handler
2145 * @timer_msec: The timeout period for the exchange
2146 *
2147 * The exchange response handler is set in this routine to resp()
2148 * function pointer. It can be called in two scenarios: if a timeout
2149 * occurs or if a response frame is received for the exchange. The
2150 * fc_frame pointer in response handler will also indicate timeout
2151 * as error using IS_ERR related macros.
2152 *
2153 * The exchange destructor handler is also set in this routine.
2154 * The destructor handler is invoked by EM layer when exchange
2155 * is about to free, this can be used by caller to free its
2156 * resources along with exchange free.
2157 *
2158 * The arg is passed back to resp and destructor handler.
2159 *
2160 * The timeout value (in msec) for an exchange is set if non zero
2161 * timer_msec argument is specified. The timer is canceled when
2162 * it fires or when the exchange is done. The exchange timeout handler
2163 * is registered by EM layer.
2164 *
2165 * The frame pointer with some of the header's fields must be
2166 * filled before calling this routine, those fields are:
2167 *
2168 * - routing control
2169 * - FC port did
2170 * - FC port sid
2171 * - FC header type
2172 * - frame control
2173 * - parameter or relative offset
2174 */
2175struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
2176 struct fc_frame *fp,
2177 void (*resp)(struct fc_seq *,
2178 struct fc_frame *fp,
2179 void *arg),
2180 void (*destructor)(struct fc_seq *, void *),
2181 void *arg, u32 timer_msec)
2182{
2183 struct fc_exch *ep;
2184 struct fc_seq *sp = NULL;
2185 struct fc_frame_header *fh;
2186 struct fc_fcp_pkt *fsp = NULL;
2187 int rc = 1;
2188
2189 ep = fc_exch_alloc(lport, fp);
2190 if (!ep) {
2191 fc_frame_free(fp);
2192 return NULL;
2193 }
2194 ep->esb_stat |= ESB_ST_SEQ_INIT;
2195 fh = fc_frame_header_get(fp);
2196 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
2197 ep->resp = resp;
2198 ep->destructor = destructor;
2199 ep->arg = arg;
2200 ep->r_a_tov = lport->r_a_tov;
2201 ep->lp = lport;
2202 sp = &ep->seq;
2203
2204 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
2205 ep->f_ctl = ntoh24(fh->fh_f_ctl);
2206 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
2207 sp->cnt++;
2208
2209 if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD) {
2210 fsp = fr_fsp(fp);
2211 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
2212 }
2213
2214 if (unlikely(lport->tt.frame_send(lport, fp)))
2215 goto err;
2216
2217 if (timer_msec)
2218 fc_exch_timer_set_locked(ep, timer_msec);
2219 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
2220
2221 if (ep->f_ctl & FC_FC_SEQ_INIT)
2222 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
2223 spin_unlock_bh(&ep->ex_lock);
2224 return sp;
2225err:
2226 if (fsp)
2227 fc_fcp_ddp_done(fsp);
2228 rc = fc_exch_done_locked(ep);
2229 spin_unlock_bh(&ep->ex_lock);
2230 if (!rc)
2231 fc_exch_delete(ep);
2232 return NULL;
2233}
2234EXPORT_SYMBOL(fc_exch_seq_send);
2235
2236/**
2237 * fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command
2238 * @ep: The exchange to send the RRQ on
2239 *
2240 * This tells the remote port to stop blocking the use of
2241 * the exchange and the seq_cnt range.
2242 */
2243static void fc_exch_rrq(struct fc_exch *ep)
2244{
2245 struct fc_lport *lport;
2246 struct fc_els_rrq *rrq;
2247 struct fc_frame *fp;
2248 u32 did;
2249
2250 lport = ep->lp;
2251
2252 fp = fc_frame_alloc(lport, sizeof(*rrq));
2253 if (!fp)
2254 goto retry;
2255
2256 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
2257 memset(rrq, 0, sizeof(*rrq));
2258 rrq->rrq_cmd = ELS_RRQ;
2259 hton24(rrq->rrq_s_id, ep->sid);
2260 rrq->rrq_ox_id = htons(ep->oxid);
2261 rrq->rrq_rx_id = htons(ep->rxid);
2262
2263 did = ep->did;
2264 if (ep->esb_stat & ESB_ST_RESP)
2265 did = ep->sid;
2266
2267 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
2268 lport->port_id, FC_TYPE_ELS,
2269 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
2270
2271 if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep,
2272 lport->e_d_tov))
2273 return;
2274
2275retry:
2276 FC_EXCH_DBG(ep, "exch: RRQ send failed\n");
2277 spin_lock_bh(&ep->ex_lock);
2278 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
2279 spin_unlock_bh(&ep->ex_lock);
2280 /* drop hold for rec qual */
2281 fc_exch_release(ep);
2282 return;
2283 }
2284 ep->esb_stat |= ESB_ST_REC_QUAL;
2285 fc_exch_timer_set_locked(ep, ep->r_a_tov);
2286 spin_unlock_bh(&ep->ex_lock);
2287}
2288
2289/**
2290 * fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests
2291 * @fp: The RRQ frame, not freed here.
2292 */
2293static void fc_exch_els_rrq(struct fc_frame *fp)
2294{
2295 struct fc_lport *lport;
2296 struct fc_exch *ep = NULL; /* request or subject exchange */
2297 struct fc_els_rrq *rp;
2298 u32 sid;
2299 u16 xid;
2300 enum fc_els_rjt_explan explan;
2301
2302 lport = fr_dev(fp);
2303 rp = fc_frame_payload_get(fp, sizeof(*rp));
2304 explan = ELS_EXPL_INV_LEN;
2305 if (!rp)
2306 goto reject;
2307
2308 /*
2309 * lookup subject exchange.
2310 */
2311 sid = ntoh24(rp->rrq_s_id); /* subject source */
2312 xid = fc_host_port_id(lport->host) == sid ?
2313 ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
2314 ep = fc_exch_lookup(lport, xid);
2315 explan = ELS_EXPL_OXID_RXID;
2316 if (!ep)
2317 goto reject;
2318 spin_lock_bh(&ep->ex_lock);
2319 FC_EXCH_DBG(ep, "RRQ request from %x: xid %x rxid %x oxid %x\n",
2320 sid, xid, ntohs(rp->rrq_rx_id), ntohs(rp->rrq_ox_id));
2321 if (ep->oxid != ntohs(rp->rrq_ox_id))
2322 goto unlock_reject;
2323 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
2324 ep->rxid != FC_XID_UNKNOWN)
2325 goto unlock_reject;
2326 explan = ELS_EXPL_SID;
2327 if (ep->sid != sid)
2328 goto unlock_reject;
2329
2330 /*
2331 * Clear Recovery Qualifier state, and cancel timer if complete.
2332 */
2333 if (ep->esb_stat & ESB_ST_REC_QUAL) {
2334 ep->esb_stat &= ~ESB_ST_REC_QUAL;
2335 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
2336 }
2337 if (ep->esb_stat & ESB_ST_COMPLETE)
2338 fc_exch_timer_cancel(ep);
2339
2340 spin_unlock_bh(&ep->ex_lock);
2341
2342 /*
2343 * Send LS_ACC.
2344 */
2345 fc_seq_ls_acc(fp);
2346 goto out;
2347
2348unlock_reject:
2349 spin_unlock_bh(&ep->ex_lock);
2350reject:
2351 fc_seq_ls_rjt(fp, ELS_RJT_LOGIC, explan);
2352out:
2353 if (ep)
2354 fc_exch_release(ep); /* drop hold from fc_exch_find */
2355}
2356
2357/**
2358 * fc_exch_update_stats() - update exches stats to lport
2359 * @lport: The local port to update exchange manager stats
2360 */
2361void fc_exch_update_stats(struct fc_lport *lport)
2362{
2363 struct fc_host_statistics *st;
2364 struct fc_exch_mgr_anchor *ema;
2365 struct fc_exch_mgr *mp;
2366
2367 st = &lport->host_stats;
2368
2369 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2370 mp = ema->mp;
2371 st->fc_no_free_exch += atomic_read(&mp->stats.no_free_exch);
2372 st->fc_no_free_exch_xid +=
2373 atomic_read(&mp->stats.no_free_exch_xid);
2374 st->fc_xid_not_found += atomic_read(&mp->stats.xid_not_found);
2375 st->fc_xid_busy += atomic_read(&mp->stats.xid_busy);
2376 st->fc_seq_not_found += atomic_read(&mp->stats.seq_not_found);
2377 st->fc_non_bls_resp += atomic_read(&mp->stats.non_bls_resp);
2378 }
2379}
2380EXPORT_SYMBOL(fc_exch_update_stats);
2381
2382/**
2383 * fc_exch_mgr_add() - Add an exchange manager to a local port's list of EMs
2384 * @lport: The local port to add the exchange manager to
2385 * @mp: The exchange manager to be added to the local port
2386 * @match: The match routine that indicates when this EM should be used
2387 */
2388struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
2389 struct fc_exch_mgr *mp,
2390 bool (*match)(struct fc_frame *))
2391{
2392 struct fc_exch_mgr_anchor *ema;
2393
2394 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
2395 if (!ema)
2396 return ema;
2397
2398 ema->mp = mp;
2399 ema->match = match;
2400 /* add EM anchor to EM anchors list */
2401 list_add_tail(&ema->ema_list, &lport->ema_list);
2402 kref_get(&mp->kref);
2403 return ema;
2404}
2405EXPORT_SYMBOL(fc_exch_mgr_add);
2406
2407/**
2408 * fc_exch_mgr_destroy() - Destroy an exchange manager
2409 * @kref: The reference to the EM to be destroyed
2410 */
2411static void fc_exch_mgr_destroy(struct kref *kref)
2412{
2413 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
2414
2415 mempool_destroy(mp->ep_pool);
2416 free_percpu(mp->pool);
2417 kfree(mp);
2418}
2419
2420/**
2421 * fc_exch_mgr_del() - Delete an EM from a local port's list
2422 * @ema: The exchange manager anchor identifying the EM to be deleted
2423 */
2424void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
2425{
2426 /* remove EM anchor from EM anchors list */
2427 list_del(&ema->ema_list);
2428 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
2429 kfree(ema);
2430}
2431EXPORT_SYMBOL(fc_exch_mgr_del);
2432
2433/**
2434 * fc_exch_mgr_list_clone() - Share all exchange manager objects
2435 * @src: Source lport to clone exchange managers from
2436 * @dst: New lport that takes references to all the exchange managers
2437 */
2438int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)
2439{
2440 struct fc_exch_mgr_anchor *ema, *tmp;
2441
2442 list_for_each_entry(ema, &src->ema_list, ema_list) {
2443 if (!fc_exch_mgr_add(dst, ema->mp, ema->match))
2444 goto err;
2445 }
2446 return 0;
2447err:
2448 list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)
2449 fc_exch_mgr_del(ema);
2450 return -ENOMEM;
2451}
2452EXPORT_SYMBOL(fc_exch_mgr_list_clone);
2453
2454/**
2455 * fc_exch_mgr_alloc() - Allocate an exchange manager
2456 * @lport: The local port that the new EM will be associated with
2457 * @class: The default FC class for new exchanges
2458 * @min_xid: The minimum XID for exchanges from the new EM
2459 * @max_xid: The maximum XID for exchanges from the new EM
2460 * @match: The match routine for the new EM
2461 */
2462struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport,
2463 enum fc_class class,
2464 u16 min_xid, u16 max_xid,
2465 bool (*match)(struct fc_frame *))
2466{
2467 struct fc_exch_mgr *mp;
2468 u16 pool_exch_range;
2469 size_t pool_size;
2470 unsigned int cpu;
2471 struct fc_exch_pool *pool;
2472
2473 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
2474 (min_xid & fc_cpu_mask) != 0) {
2475 FC_LPORT_DBG(lport, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
2476 min_xid, max_xid);
2477 return NULL;
2478 }
2479
2480 /*
2481 * allocate memory for EM
2482 */
2483 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
2484 if (!mp)
2485 return NULL;
2486
2487 mp->class = class;
2488 mp->lport = lport;
2489 /* adjust em exch xid range for offload */
2490 mp->min_xid = min_xid;
2491
2492 /* reduce range so per cpu pool fits into PCPU_MIN_UNIT_SIZE pool */
2493 pool_exch_range = (PCPU_MIN_UNIT_SIZE - sizeof(*pool)) /
2494 sizeof(struct fc_exch *);
2495 if ((max_xid - min_xid + 1) / (fc_cpu_mask + 1) > pool_exch_range) {
2496 mp->max_xid = pool_exch_range * (fc_cpu_mask + 1) +
2497 min_xid - 1;
2498 } else {
2499 mp->max_xid = max_xid;
2500 pool_exch_range = (mp->max_xid - mp->min_xid + 1) /
2501 (fc_cpu_mask + 1);
2502 }
2503
2504 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
2505 if (!mp->ep_pool)
2506 goto free_mp;
2507
2508 /*
2509 * Setup per cpu exch pool with entire exchange id range equally
2510 * divided across all cpus. The exch pointers array memory is
2511 * allocated for exch range per pool.
2512 */
2513 mp->pool_max_index = pool_exch_range - 1;
2514
2515 /*
2516 * Allocate and initialize per cpu exch pool
2517 */
2518 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
2519 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
2520 if (!mp->pool)
2521 goto free_mempool;
2522 for_each_possible_cpu(cpu) {
2523 pool = per_cpu_ptr(mp->pool, cpu);
2524 pool->next_index = 0;
2525 pool->left = FC_XID_UNKNOWN;
2526 pool->right = FC_XID_UNKNOWN;
2527 spin_lock_init(&pool->lock);
2528 INIT_LIST_HEAD(&pool->ex_list);
2529 }
2530
2531 kref_init(&mp->kref);
2532 if (!fc_exch_mgr_add(lport, mp, match)) {
2533 free_percpu(mp->pool);
2534 goto free_mempool;
2535 }
2536
2537 /*
2538 * Above kref_init() sets mp->kref to 1 and then
2539 * call to fc_exch_mgr_add incremented mp->kref again,
2540 * so adjust that extra increment.
2541 */
2542 kref_put(&mp->kref, fc_exch_mgr_destroy);
2543 return mp;
2544
2545free_mempool:
2546 mempool_destroy(mp->ep_pool);
2547free_mp:
2548 kfree(mp);
2549 return NULL;
2550}
2551EXPORT_SYMBOL(fc_exch_mgr_alloc);
2552
2553/**
2554 * fc_exch_mgr_free() - Free all exchange managers on a local port
2555 * @lport: The local port whose EMs are to be freed
2556 */
2557void fc_exch_mgr_free(struct fc_lport *lport)
2558{
2559 struct fc_exch_mgr_anchor *ema, *next;
2560
2561 flush_workqueue(fc_exch_workqueue);
2562 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
2563 fc_exch_mgr_del(ema);
2564}
2565EXPORT_SYMBOL(fc_exch_mgr_free);
2566
2567/**
2568 * fc_find_ema() - Lookup and return appropriate Exchange Manager Anchor depending
2569 * upon 'xid'.
2570 * @f_ctl: f_ctl
2571 * @lport: The local port the frame was received on
2572 * @fh: The received frame header
2573 */
2574static struct fc_exch_mgr_anchor *fc_find_ema(u32 f_ctl,
2575 struct fc_lport *lport,
2576 struct fc_frame_header *fh)
2577{
2578 struct fc_exch_mgr_anchor *ema;
2579 u16 xid;
2580
2581 if (f_ctl & FC_FC_EX_CTX)
2582 xid = ntohs(fh->fh_ox_id);
2583 else {
2584 xid = ntohs(fh->fh_rx_id);
2585 if (xid == FC_XID_UNKNOWN)
2586 return list_entry(lport->ema_list.prev,
2587 typeof(*ema), ema_list);
2588 }
2589
2590 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2591 if ((xid >= ema->mp->min_xid) &&
2592 (xid <= ema->mp->max_xid))
2593 return ema;
2594 }
2595 return NULL;
2596}
2597/**
2598 * fc_exch_recv() - Handler for received frames
2599 * @lport: The local port the frame was received on
2600 * @fp: The received frame
2601 */
2602void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)
2603{
2604 struct fc_frame_header *fh = fc_frame_header_get(fp);
2605 struct fc_exch_mgr_anchor *ema;
2606 u32 f_ctl;
2607
2608 /* lport lock ? */
2609 if (!lport || lport->state == LPORT_ST_DISABLED) {
2610 FC_LIBFC_DBG("Receiving frames for an lport that "
2611 "has not been initialized correctly\n");
2612 fc_frame_free(fp);
2613 return;
2614 }
2615
2616 f_ctl = ntoh24(fh->fh_f_ctl);
2617 ema = fc_find_ema(f_ctl, lport, fh);
2618 if (!ema) {
2619 FC_LPORT_DBG(lport, "Unable to find Exchange Manager Anchor,"
2620 "fc_ctl <0x%x>, xid <0x%x>\n",
2621 f_ctl,
2622 (f_ctl & FC_FC_EX_CTX) ?
2623 ntohs(fh->fh_ox_id) :
2624 ntohs(fh->fh_rx_id));
2625 fc_frame_free(fp);
2626 return;
2627 }
2628
2629 /*
2630 * If frame is marked invalid, just drop it.
2631 */
2632 switch (fr_eof(fp)) {
2633 case FC_EOF_T:
2634 if (f_ctl & FC_FC_END_SEQ)
2635 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2636 fallthrough;
2637 case FC_EOF_N:
2638 if (fh->fh_type == FC_TYPE_BLS)
2639 fc_exch_recv_bls(ema->mp, fp);
2640 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2641 FC_FC_EX_CTX)
2642 fc_exch_recv_seq_resp(ema->mp, fp);
2643 else if (f_ctl & FC_FC_SEQ_CTX)
2644 fc_exch_recv_resp(ema->mp, fp);
2645 else /* no EX_CTX and no SEQ_CTX */
2646 fc_exch_recv_req(lport, ema->mp, fp);
2647 break;
2648 default:
2649 FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)",
2650 fr_eof(fp));
2651 fc_frame_free(fp);
2652 }
2653}
2654EXPORT_SYMBOL(fc_exch_recv);
2655
2656/**
2657 * fc_exch_init() - Initialize the exchange layer for a local port
2658 * @lport: The local port to initialize the exchange layer for
2659 */
2660int fc_exch_init(struct fc_lport *lport)
2661{
2662 if (!lport->tt.exch_mgr_reset)
2663 lport->tt.exch_mgr_reset = fc_exch_mgr_reset;
2664
2665 return 0;
2666}
2667EXPORT_SYMBOL(fc_exch_init);
2668
2669/**
2670 * fc_setup_exch_mgr() - Setup an exchange manager
2671 */
2672int fc_setup_exch_mgr(void)
2673{
2674 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2675 0, SLAB_HWCACHE_ALIGN, NULL);
2676 if (!fc_em_cachep)
2677 return -ENOMEM;
2678
2679 /*
2680 * Initialize fc_cpu_mask and fc_cpu_order. The
2681 * fc_cpu_mask is set for nr_cpu_ids rounded up
2682 * to order of 2's * power and order is stored
2683 * in fc_cpu_order as this is later required in
2684 * mapping between an exch id and exch array index
2685 * in per cpu exch pool.
2686 *
2687 * This round up is required to align fc_cpu_mask
2688 * to exchange id's lower bits such that all incoming
2689 * frames of an exchange gets delivered to the same
2690 * cpu on which exchange originated by simple bitwise
2691 * AND operation between fc_cpu_mask and exchange id.
2692 */
2693 fc_cpu_order = ilog2(roundup_pow_of_two(nr_cpu_ids));
2694 fc_cpu_mask = (1 << fc_cpu_order) - 1;
2695
2696 fc_exch_workqueue = create_singlethread_workqueue("fc_exch_workqueue");
2697 if (!fc_exch_workqueue)
2698 goto err;
2699 return 0;
2700err:
2701 kmem_cache_destroy(fc_em_cachep);
2702 return -ENOMEM;
2703}
2704
2705/**
2706 * fc_destroy_exch_mgr() - Destroy an exchange manager
2707 */
2708void fc_destroy_exch_mgr(void)
2709{
2710 destroy_workqueue(fc_exch_workqueue);
2711 kmem_cache_destroy(fc_em_cachep);
2712}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright(c) 2007 Intel Corporation. All rights reserved.
4 * Copyright(c) 2008 Red Hat, Inc. All rights reserved.
5 * Copyright(c) 2008 Mike Christie
6 *
7 * Maintained at www.Open-FCoE.org
8 */
9
10/*
11 * Fibre Channel exchange and sequence handling.
12 */
13
14#include <linux/timer.h>
15#include <linux/slab.h>
16#include <linux/err.h>
17#include <linux/export.h>
18#include <linux/log2.h>
19
20#include <scsi/fc/fc_fc2.h>
21
22#include <scsi/libfc.h>
23
24#include "fc_libfc.h"
25
26u16 fc_cpu_mask; /* cpu mask for possible cpus */
27EXPORT_SYMBOL(fc_cpu_mask);
28static u16 fc_cpu_order; /* 2's power to represent total possible cpus */
29static struct kmem_cache *fc_em_cachep; /* cache for exchanges */
30static struct workqueue_struct *fc_exch_workqueue;
31
32/*
33 * Structure and function definitions for managing Fibre Channel Exchanges
34 * and Sequences.
35 *
36 * The three primary structures used here are fc_exch_mgr, fc_exch, and fc_seq.
37 *
38 * fc_exch_mgr holds the exchange state for an N port
39 *
40 * fc_exch holds state for one exchange and links to its active sequence.
41 *
42 * fc_seq holds the state for an individual sequence.
43 */
44
45/**
46 * struct fc_exch_pool - Per cpu exchange pool
47 * @next_index: Next possible free exchange index
48 * @total_exches: Total allocated exchanges
49 * @lock: Exch pool lock
50 * @ex_list: List of exchanges
51 * @left: Cache of free slot in exch array
52 * @right: Cache of free slot in exch array
53 *
54 * This structure manages per cpu exchanges in array of exchange pointers.
55 * This array is allocated followed by struct fc_exch_pool memory for
56 * assigned range of exchanges to per cpu pool.
57 */
58struct fc_exch_pool {
59 spinlock_t lock;
60 struct list_head ex_list;
61 u16 next_index;
62 u16 total_exches;
63
64 u16 left;
65 u16 right;
66} ____cacheline_aligned_in_smp;
67
68/**
69 * struct fc_exch_mgr - The Exchange Manager (EM).
70 * @class: Default class for new sequences
71 * @kref: Reference counter
72 * @min_xid: Minimum exchange ID
73 * @max_xid: Maximum exchange ID
74 * @ep_pool: Reserved exchange pointers
75 * @pool_max_index: Max exch array index in exch pool
76 * @pool: Per cpu exch pool
77 * @lport: Local exchange port
78 * @stats: Statistics structure
79 *
80 * This structure is the center for creating exchanges and sequences.
81 * It manages the allocation of exchange IDs.
82 */
83struct fc_exch_mgr {
84 struct fc_exch_pool __percpu *pool;
85 mempool_t *ep_pool;
86 struct fc_lport *lport;
87 enum fc_class class;
88 struct kref kref;
89 u16 min_xid;
90 u16 max_xid;
91 u16 pool_max_index;
92
93 struct {
94 atomic_t no_free_exch;
95 atomic_t no_free_exch_xid;
96 atomic_t xid_not_found;
97 atomic_t xid_busy;
98 atomic_t seq_not_found;
99 atomic_t non_bls_resp;
100 } stats;
101};
102
103/**
104 * struct fc_exch_mgr_anchor - primary structure for list of EMs
105 * @ema_list: Exchange Manager Anchor list
106 * @mp: Exchange Manager associated with this anchor
107 * @match: Routine to determine if this anchor's EM should be used
108 *
109 * When walking the list of anchors the match routine will be called
110 * for each anchor to determine if that EM should be used. The last
111 * anchor in the list will always match to handle any exchanges not
112 * handled by other EMs. The non-default EMs would be added to the
113 * anchor list by HW that provides offloads.
114 */
115struct fc_exch_mgr_anchor {
116 struct list_head ema_list;
117 struct fc_exch_mgr *mp;
118 bool (*match)(struct fc_frame *);
119};
120
121static void fc_exch_rrq(struct fc_exch *);
122static void fc_seq_ls_acc(struct fc_frame *);
123static void fc_seq_ls_rjt(struct fc_frame *, enum fc_els_rjt_reason,
124 enum fc_els_rjt_explan);
125static void fc_exch_els_rec(struct fc_frame *);
126static void fc_exch_els_rrq(struct fc_frame *);
127
128/*
129 * Internal implementation notes.
130 *
131 * The exchange manager is one by default in libfc but LLD may choose
132 * to have one per CPU. The sequence manager is one per exchange manager
133 * and currently never separated.
134 *
135 * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field
136 * assigned by the Sequence Initiator that shall be unique for a specific
137 * D_ID and S_ID pair while the Sequence is open." Note that it isn't
138 * qualified by exchange ID, which one might think it would be.
139 * In practice this limits the number of open sequences and exchanges to 256
140 * per session. For most targets we could treat this limit as per exchange.
141 *
142 * The exchange and its sequence are freed when the last sequence is received.
143 * It's possible for the remote port to leave an exchange open without
144 * sending any sequences.
145 *
146 * Notes on reference counts:
147 *
148 * Exchanges are reference counted and exchange gets freed when the reference
149 * count becomes zero.
150 *
151 * Timeouts:
152 * Sequences are timed out for E_D_TOV and R_A_TOV.
153 *
154 * Sequence event handling:
155 *
156 * The following events may occur on initiator sequences:
157 *
158 * Send.
159 * For now, the whole thing is sent.
160 * Receive ACK
161 * This applies only to class F.
162 * The sequence is marked complete.
163 * ULP completion.
164 * The upper layer calls fc_exch_done() when done
165 * with exchange and sequence tuple.
166 * RX-inferred completion.
167 * When we receive the next sequence on the same exchange, we can
168 * retire the previous sequence ID. (XXX not implemented).
169 * Timeout.
170 * R_A_TOV frees the sequence ID. If we're waiting for ACK,
171 * E_D_TOV causes abort and calls upper layer response handler
172 * with FC_EX_TIMEOUT error.
173 * Receive RJT
174 * XXX defer.
175 * Send ABTS
176 * On timeout.
177 *
178 * The following events may occur on recipient sequences:
179 *
180 * Receive
181 * Allocate sequence for first frame received.
182 * Hold during receive handler.
183 * Release when final frame received.
184 * Keep status of last N of these for the ELS RES command. XXX TBD.
185 * Receive ABTS
186 * Deallocate sequence
187 * Send RJT
188 * Deallocate
189 *
190 * For now, we neglect conditions where only part of a sequence was
191 * received or transmitted, or where out-of-order receipt is detected.
192 */
193
194/*
195 * Locking notes:
196 *
197 * The EM code run in a per-CPU worker thread.
198 *
199 * To protect against concurrency between a worker thread code and timers,
200 * sequence allocation and deallocation must be locked.
201 * - exchange refcnt can be done atomicly without locks.
202 * - sequence allocation must be locked by exch lock.
203 * - If the EM pool lock and ex_lock must be taken at the same time, then the
204 * EM pool lock must be taken before the ex_lock.
205 */
206
207/*
208 * opcode names for debugging.
209 */
210static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;
211
212/**
213 * fc_exch_name_lookup() - Lookup name by opcode
214 * @op: Opcode to be looked up
215 * @table: Opcode/name table
216 * @max_index: Index not to be exceeded
217 *
218 * This routine is used to determine a human-readable string identifying
219 * a R_CTL opcode.
220 */
221static inline const char *fc_exch_name_lookup(unsigned int op, char **table,
222 unsigned int max_index)
223{
224 const char *name = NULL;
225
226 if (op < max_index)
227 name = table[op];
228 if (!name)
229 name = "unknown";
230 return name;
231}
232
233/**
234 * fc_exch_rctl_name() - Wrapper routine for fc_exch_name_lookup()
235 * @op: The opcode to be looked up
236 */
237static const char *fc_exch_rctl_name(unsigned int op)
238{
239 return fc_exch_name_lookup(op, fc_exch_rctl_names,
240 ARRAY_SIZE(fc_exch_rctl_names));
241}
242
243/**
244 * fc_exch_hold() - Increment an exchange's reference count
245 * @ep: Echange to be held
246 */
247static inline void fc_exch_hold(struct fc_exch *ep)
248{
249 atomic_inc(&ep->ex_refcnt);
250}
251
252/**
253 * fc_exch_setup_hdr() - Initialize a FC header by initializing some fields
254 * and determine SOF and EOF.
255 * @ep: The exchange to that will use the header
256 * @fp: The frame whose header is to be modified
257 * @f_ctl: F_CTL bits that will be used for the frame header
258 *
259 * The fields initialized by this routine are: fh_ox_id, fh_rx_id,
260 * fh_seq_id, fh_seq_cnt and the SOF and EOF.
261 */
262static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,
263 u32 f_ctl)
264{
265 struct fc_frame_header *fh = fc_frame_header_get(fp);
266 u16 fill;
267
268 fr_sof(fp) = ep->class;
269 if (ep->seq.cnt)
270 fr_sof(fp) = fc_sof_normal(ep->class);
271
272 if (f_ctl & FC_FC_END_SEQ) {
273 fr_eof(fp) = FC_EOF_T;
274 if (fc_sof_needs_ack((enum fc_sof)ep->class))
275 fr_eof(fp) = FC_EOF_N;
276 /*
277 * From F_CTL.
278 * The number of fill bytes to make the length a 4-byte
279 * multiple is the low order 2-bits of the f_ctl.
280 * The fill itself will have been cleared by the frame
281 * allocation.
282 * After this, the length will be even, as expected by
283 * the transport.
284 */
285 fill = fr_len(fp) & 3;
286 if (fill) {
287 fill = 4 - fill;
288 /* TODO, this may be a problem with fragmented skb */
289 skb_put(fp_skb(fp), fill);
290 hton24(fh->fh_f_ctl, f_ctl | fill);
291 }
292 } else {
293 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
294 fr_eof(fp) = FC_EOF_N;
295 }
296
297 /* Initialize remaining fh fields from fc_fill_fc_hdr */
298 fh->fh_ox_id = htons(ep->oxid);
299 fh->fh_rx_id = htons(ep->rxid);
300 fh->fh_seq_id = ep->seq.id;
301 fh->fh_seq_cnt = htons(ep->seq.cnt);
302}
303
304/**
305 * fc_exch_release() - Decrement an exchange's reference count
306 * @ep: Exchange to be released
307 *
308 * If the reference count reaches zero and the exchange is complete,
309 * it is freed.
310 */
311static void fc_exch_release(struct fc_exch *ep)
312{
313 struct fc_exch_mgr *mp;
314
315 if (atomic_dec_and_test(&ep->ex_refcnt)) {
316 mp = ep->em;
317 if (ep->destructor)
318 ep->destructor(&ep->seq, ep->arg);
319 WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));
320 mempool_free(ep, mp->ep_pool);
321 }
322}
323
324/**
325 * fc_exch_timer_cancel() - cancel exch timer
326 * @ep: The exchange whose timer to be canceled
327 */
328static inline void fc_exch_timer_cancel(struct fc_exch *ep)
329{
330 if (cancel_delayed_work(&ep->timeout_work)) {
331 FC_EXCH_DBG(ep, "Exchange timer canceled\n");
332 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
333 }
334}
335
336/**
337 * fc_exch_timer_set_locked() - Start a timer for an exchange w/ the
338 * the exchange lock held
339 * @ep: The exchange whose timer will start
340 * @timer_msec: The timeout period
341 *
342 * Used for upper level protocols to time out the exchange.
343 * The timer is cancelled when it fires or when the exchange completes.
344 */
345static inline void fc_exch_timer_set_locked(struct fc_exch *ep,
346 unsigned int timer_msec)
347{
348 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
349 return;
350
351 FC_EXCH_DBG(ep, "Exchange timer armed : %d msecs\n", timer_msec);
352
353 fc_exch_hold(ep); /* hold for timer */
354 if (!queue_delayed_work(fc_exch_workqueue, &ep->timeout_work,
355 msecs_to_jiffies(timer_msec))) {
356 FC_EXCH_DBG(ep, "Exchange already queued\n");
357 fc_exch_release(ep);
358 }
359}
360
361/**
362 * fc_exch_timer_set() - Lock the exchange and set the timer
363 * @ep: The exchange whose timer will start
364 * @timer_msec: The timeout period
365 */
366static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec)
367{
368 spin_lock_bh(&ep->ex_lock);
369 fc_exch_timer_set_locked(ep, timer_msec);
370 spin_unlock_bh(&ep->ex_lock);
371}
372
373/**
374 * fc_exch_done_locked() - Complete an exchange with the exchange lock held
375 * @ep: The exchange that is complete
376 *
377 * Note: May sleep if invoked from outside a response handler.
378 */
379static int fc_exch_done_locked(struct fc_exch *ep)
380{
381 int rc = 1;
382
383 /*
384 * We must check for completion in case there are two threads
385 * tyring to complete this. But the rrq code will reuse the
386 * ep, and in that case we only clear the resp and set it as
387 * complete, so it can be reused by the timer to send the rrq.
388 */
389 if (ep->state & FC_EX_DONE)
390 return rc;
391 ep->esb_stat |= ESB_ST_COMPLETE;
392
393 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
394 ep->state |= FC_EX_DONE;
395 fc_exch_timer_cancel(ep);
396 rc = 0;
397 }
398 return rc;
399}
400
401static struct fc_exch fc_quarantine_exch;
402
403/**
404 * fc_exch_ptr_get() - Return an exchange from an exchange pool
405 * @pool: Exchange Pool to get an exchange from
406 * @index: Index of the exchange within the pool
407 *
408 * Use the index to get an exchange from within an exchange pool. exches
409 * will point to an array of exchange pointers. The index will select
410 * the exchange within the array.
411 */
412static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,
413 u16 index)
414{
415 struct fc_exch **exches = (struct fc_exch **)(pool + 1);
416 return exches[index];
417}
418
419/**
420 * fc_exch_ptr_set() - Assign an exchange to a slot in an exchange pool
421 * @pool: The pool to assign the exchange to
422 * @index: The index in the pool where the exchange will be assigned
423 * @ep: The exchange to assign to the pool
424 */
425static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
426 struct fc_exch *ep)
427{
428 ((struct fc_exch **)(pool + 1))[index] = ep;
429}
430
431/**
432 * fc_exch_delete() - Delete an exchange
433 * @ep: The exchange to be deleted
434 */
435static void fc_exch_delete(struct fc_exch *ep)
436{
437 struct fc_exch_pool *pool;
438 u16 index;
439
440 pool = ep->pool;
441 spin_lock_bh(&pool->lock);
442 WARN_ON(pool->total_exches <= 0);
443 pool->total_exches--;
444
445 /* update cache of free slot */
446 index = (ep->xid - ep->em->min_xid) >> fc_cpu_order;
447 if (!(ep->state & FC_EX_QUARANTINE)) {
448 if (pool->left == FC_XID_UNKNOWN)
449 pool->left = index;
450 else if (pool->right == FC_XID_UNKNOWN)
451 pool->right = index;
452 else
453 pool->next_index = index;
454 fc_exch_ptr_set(pool, index, NULL);
455 } else {
456 fc_exch_ptr_set(pool, index, &fc_quarantine_exch);
457 }
458 list_del(&ep->ex_list);
459 spin_unlock_bh(&pool->lock);
460 fc_exch_release(ep); /* drop hold for exch in mp */
461}
462
463static int fc_seq_send_locked(struct fc_lport *lport, struct fc_seq *sp,
464 struct fc_frame *fp)
465{
466 struct fc_exch *ep;
467 struct fc_frame_header *fh = fc_frame_header_get(fp);
468 int error = -ENXIO;
469 u32 f_ctl;
470 u8 fh_type = fh->fh_type;
471
472 ep = fc_seq_exch(sp);
473
474 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL)) {
475 fc_frame_free(fp);
476 goto out;
477 }
478
479 WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT));
480
481 f_ctl = ntoh24(fh->fh_f_ctl);
482 fc_exch_setup_hdr(ep, fp, f_ctl);
483 fr_encaps(fp) = ep->encaps;
484
485 /*
486 * update sequence count if this frame is carrying
487 * multiple FC frames when sequence offload is enabled
488 * by LLD.
489 */
490 if (fr_max_payload(fp))
491 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),
492 fr_max_payload(fp));
493 else
494 sp->cnt++;
495
496 /*
497 * Send the frame.
498 */
499 error = lport->tt.frame_send(lport, fp);
500
501 if (fh_type == FC_TYPE_BLS)
502 goto out;
503
504 /*
505 * Update the exchange and sequence flags,
506 * assuming all frames for the sequence have been sent.
507 * We can only be called to send once for each sequence.
508 */
509 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
510 if (f_ctl & FC_FC_SEQ_INIT)
511 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
512out:
513 return error;
514}
515
516/**
517 * fc_seq_send() - Send a frame using existing sequence/exchange pair
518 * @lport: The local port that the exchange will be sent on
519 * @sp: The sequence to be sent
520 * @fp: The frame to be sent on the exchange
521 *
522 * Note: The frame will be freed either by a direct call to fc_frame_free(fp)
523 * or indirectly by calling libfc_function_template.frame_send().
524 */
525int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp, struct fc_frame *fp)
526{
527 struct fc_exch *ep;
528 int error;
529 ep = fc_seq_exch(sp);
530 spin_lock_bh(&ep->ex_lock);
531 error = fc_seq_send_locked(lport, sp, fp);
532 spin_unlock_bh(&ep->ex_lock);
533 return error;
534}
535EXPORT_SYMBOL(fc_seq_send);
536
537/**
538 * fc_seq_alloc() - Allocate a sequence for a given exchange
539 * @ep: The exchange to allocate a new sequence for
540 * @seq_id: The sequence ID to be used
541 *
542 * We don't support multiple originated sequences on the same exchange.
543 * By implication, any previously originated sequence on this exchange
544 * is complete, and we reallocate the same sequence.
545 */
546static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
547{
548 struct fc_seq *sp;
549
550 sp = &ep->seq;
551 sp->ssb_stat = 0;
552 sp->cnt = 0;
553 sp->id = seq_id;
554 return sp;
555}
556
557/**
558 * fc_seq_start_next_locked() - Allocate a new sequence on the same
559 * exchange as the supplied sequence
560 * @sp: The sequence/exchange to get a new sequence for
561 */
562static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
563{
564 struct fc_exch *ep = fc_seq_exch(sp);
565
566 sp = fc_seq_alloc(ep, ep->seq_id++);
567 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
568 ep->f_ctl, sp->id);
569 return sp;
570}
571
572/**
573 * fc_seq_start_next() - Lock the exchange and get a new sequence
574 * for a given sequence/exchange pair
575 * @sp: The sequence/exchange to get a new exchange for
576 */
577struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
578{
579 struct fc_exch *ep = fc_seq_exch(sp);
580
581 spin_lock_bh(&ep->ex_lock);
582 sp = fc_seq_start_next_locked(sp);
583 spin_unlock_bh(&ep->ex_lock);
584
585 return sp;
586}
587EXPORT_SYMBOL(fc_seq_start_next);
588
589/*
590 * Set the response handler for the exchange associated with a sequence.
591 *
592 * Note: May sleep if invoked from outside a response handler.
593 */
594void fc_seq_set_resp(struct fc_seq *sp,
595 void (*resp)(struct fc_seq *, struct fc_frame *, void *),
596 void *arg)
597{
598 struct fc_exch *ep = fc_seq_exch(sp);
599 DEFINE_WAIT(wait);
600
601 spin_lock_bh(&ep->ex_lock);
602 while (ep->resp_active && ep->resp_task != current) {
603 prepare_to_wait(&ep->resp_wq, &wait, TASK_UNINTERRUPTIBLE);
604 spin_unlock_bh(&ep->ex_lock);
605
606 schedule();
607
608 spin_lock_bh(&ep->ex_lock);
609 }
610 finish_wait(&ep->resp_wq, &wait);
611 ep->resp = resp;
612 ep->arg = arg;
613 spin_unlock_bh(&ep->ex_lock);
614}
615EXPORT_SYMBOL(fc_seq_set_resp);
616
617/**
618 * fc_exch_abort_locked() - Abort an exchange
619 * @ep: The exchange to be aborted
620 * @timer_msec: The period of time to wait before aborting
621 *
622 * Abort an exchange and sequence. Generally called because of a
623 * exchange timeout or an abort from the upper layer.
624 *
625 * A timer_msec can be specified for abort timeout, if non-zero
626 * timer_msec value is specified then exchange resp handler
627 * will be called with timeout error if no response to abort.
628 *
629 * Locking notes: Called with exch lock held
630 *
631 * Return value: 0 on success else error code
632 */
633static int fc_exch_abort_locked(struct fc_exch *ep,
634 unsigned int timer_msec)
635{
636 struct fc_seq *sp;
637 struct fc_frame *fp;
638 int error;
639
640 FC_EXCH_DBG(ep, "exch: abort, time %d msecs\n", timer_msec);
641 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
642 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
643 FC_EXCH_DBG(ep, "exch: already completed esb %x state %x\n",
644 ep->esb_stat, ep->state);
645 return -ENXIO;
646 }
647
648 /*
649 * Send the abort on a new sequence if possible.
650 */
651 sp = fc_seq_start_next_locked(&ep->seq);
652 if (!sp)
653 return -ENOMEM;
654
655 if (timer_msec)
656 fc_exch_timer_set_locked(ep, timer_msec);
657
658 if (ep->sid) {
659 /*
660 * Send an abort for the sequence that timed out.
661 */
662 fp = fc_frame_alloc(ep->lp, 0);
663 if (fp) {
664 ep->esb_stat |= ESB_ST_SEQ_INIT;
665 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
666 FC_TYPE_BLS, FC_FC_END_SEQ |
667 FC_FC_SEQ_INIT, 0);
668 error = fc_seq_send_locked(ep->lp, sp, fp);
669 } else {
670 error = -ENOBUFS;
671 }
672 } else {
673 /*
674 * If not logged into the fabric, don't send ABTS but leave
675 * sequence active until next timeout.
676 */
677 error = 0;
678 }
679 ep->esb_stat |= ESB_ST_ABNORMAL;
680 return error;
681}
682
683/**
684 * fc_seq_exch_abort() - Abort an exchange and sequence
685 * @req_sp: The sequence to be aborted
686 * @timer_msec: The period of time to wait before aborting
687 *
688 * Generally called because of a timeout or an abort from the upper layer.
689 *
690 * Return value: 0 on success else error code
691 */
692int fc_seq_exch_abort(const struct fc_seq *req_sp, unsigned int timer_msec)
693{
694 struct fc_exch *ep;
695 int error;
696
697 ep = fc_seq_exch(req_sp);
698 spin_lock_bh(&ep->ex_lock);
699 error = fc_exch_abort_locked(ep, timer_msec);
700 spin_unlock_bh(&ep->ex_lock);
701 return error;
702}
703
704/**
705 * fc_invoke_resp() - invoke ep->resp()
706 * @ep: The exchange to be operated on
707 * @fp: The frame pointer to pass through to ->resp()
708 * @sp: The sequence pointer to pass through to ->resp()
709 *
710 * Notes:
711 * It is assumed that after initialization finished (this means the
712 * first unlock of ex_lock after fc_exch_alloc()) ep->resp and ep->arg are
713 * modified only via fc_seq_set_resp(). This guarantees that none of these
714 * two variables changes if ep->resp_active > 0.
715 *
716 * If an fc_seq_set_resp() call is busy modifying ep->resp and ep->arg when
717 * this function is invoked, the first spin_lock_bh() call in this function
718 * will wait until fc_seq_set_resp() has finished modifying these variables.
719 *
720 * Since fc_exch_done() invokes fc_seq_set_resp() it is guaranteed that that
721 * ep->resp() won't be invoked after fc_exch_done() has returned.
722 *
723 * The response handler itself may invoke fc_exch_done(), which will clear the
724 * ep->resp pointer.
725 *
726 * Return value:
727 * Returns true if and only if ep->resp has been invoked.
728 */
729static bool fc_invoke_resp(struct fc_exch *ep, struct fc_seq *sp,
730 struct fc_frame *fp)
731{
732 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
733 void *arg;
734 bool res = false;
735
736 spin_lock_bh(&ep->ex_lock);
737 ep->resp_active++;
738 if (ep->resp_task != current)
739 ep->resp_task = !ep->resp_task ? current : NULL;
740 resp = ep->resp;
741 arg = ep->arg;
742 spin_unlock_bh(&ep->ex_lock);
743
744 if (resp) {
745 resp(sp, fp, arg);
746 res = true;
747 }
748
749 spin_lock_bh(&ep->ex_lock);
750 if (--ep->resp_active == 0)
751 ep->resp_task = NULL;
752 spin_unlock_bh(&ep->ex_lock);
753
754 if (ep->resp_active == 0)
755 wake_up(&ep->resp_wq);
756
757 return res;
758}
759
760/**
761 * fc_exch_timeout() - Handle exchange timer expiration
762 * @work: The work_struct identifying the exchange that timed out
763 */
764static void fc_exch_timeout(struct work_struct *work)
765{
766 struct fc_exch *ep = container_of(work, struct fc_exch,
767 timeout_work.work);
768 struct fc_seq *sp = &ep->seq;
769 u32 e_stat;
770 int rc = 1;
771
772 FC_EXCH_DBG(ep, "Exchange timed out state %x\n", ep->state);
773
774 spin_lock_bh(&ep->ex_lock);
775 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
776 goto unlock;
777
778 e_stat = ep->esb_stat;
779 if (e_stat & ESB_ST_COMPLETE) {
780 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
781 spin_unlock_bh(&ep->ex_lock);
782 if (e_stat & ESB_ST_REC_QUAL)
783 fc_exch_rrq(ep);
784 goto done;
785 } else {
786 if (e_stat & ESB_ST_ABNORMAL)
787 rc = fc_exch_done_locked(ep);
788 spin_unlock_bh(&ep->ex_lock);
789 if (!rc)
790 fc_exch_delete(ep);
791 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_TIMEOUT));
792 fc_seq_set_resp(sp, NULL, ep->arg);
793 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
794 goto done;
795 }
796unlock:
797 spin_unlock_bh(&ep->ex_lock);
798done:
799 /*
800 * This release matches the hold taken when the timer was set.
801 */
802 fc_exch_release(ep);
803}
804
805/**
806 * fc_exch_em_alloc() - Allocate an exchange from a specified EM.
807 * @lport: The local port that the exchange is for
808 * @mp: The exchange manager that will allocate the exchange
809 *
810 * Returns pointer to allocated fc_exch with exch lock held.
811 */
812static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
813 struct fc_exch_mgr *mp)
814{
815 struct fc_exch *ep;
816 unsigned int cpu;
817 u16 index;
818 struct fc_exch_pool *pool;
819
820 /* allocate memory for exchange */
821 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);
822 if (!ep) {
823 atomic_inc(&mp->stats.no_free_exch);
824 goto out;
825 }
826 memset(ep, 0, sizeof(*ep));
827
828 cpu = raw_smp_processor_id();
829 pool = per_cpu_ptr(mp->pool, cpu);
830 spin_lock_bh(&pool->lock);
831
832 /* peek cache of free slot */
833 if (pool->left != FC_XID_UNKNOWN) {
834 if (!WARN_ON(fc_exch_ptr_get(pool, pool->left))) {
835 index = pool->left;
836 pool->left = FC_XID_UNKNOWN;
837 goto hit;
838 }
839 }
840 if (pool->right != FC_XID_UNKNOWN) {
841 if (!WARN_ON(fc_exch_ptr_get(pool, pool->right))) {
842 index = pool->right;
843 pool->right = FC_XID_UNKNOWN;
844 goto hit;
845 }
846 }
847
848 index = pool->next_index;
849 /* allocate new exch from pool */
850 while (fc_exch_ptr_get(pool, index)) {
851 index = index == mp->pool_max_index ? 0 : index + 1;
852 if (index == pool->next_index)
853 goto err;
854 }
855 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
856hit:
857 fc_exch_hold(ep); /* hold for exch in mp */
858 spin_lock_init(&ep->ex_lock);
859 /*
860 * Hold exch lock for caller to prevent fc_exch_reset()
861 * from releasing exch while fc_exch_alloc() caller is
862 * still working on exch.
863 */
864 spin_lock_bh(&ep->ex_lock);
865
866 fc_exch_ptr_set(pool, index, ep);
867 list_add_tail(&ep->ex_list, &pool->ex_list);
868 fc_seq_alloc(ep, ep->seq_id++);
869 pool->total_exches++;
870 spin_unlock_bh(&pool->lock);
871
872 /*
873 * update exchange
874 */
875 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
876 ep->em = mp;
877 ep->pool = pool;
878 ep->lp = lport;
879 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
880 ep->rxid = FC_XID_UNKNOWN;
881 ep->class = mp->class;
882 ep->resp_active = 0;
883 init_waitqueue_head(&ep->resp_wq);
884 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
885out:
886 return ep;
887err:
888 spin_unlock_bh(&pool->lock);
889 atomic_inc(&mp->stats.no_free_exch_xid);
890 mempool_free(ep, mp->ep_pool);
891 return NULL;
892}
893
894/**
895 * fc_exch_alloc() - Allocate an exchange from an EM on a
896 * local port's list of EMs.
897 * @lport: The local port that will own the exchange
898 * @fp: The FC frame that the exchange will be for
899 *
900 * This function walks the list of exchange manager(EM)
901 * anchors to select an EM for a new exchange allocation. The
902 * EM is selected when a NULL match function pointer is encountered
903 * or when a call to a match function returns true.
904 */
905static struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
906 struct fc_frame *fp)
907{
908 struct fc_exch_mgr_anchor *ema;
909 struct fc_exch *ep;
910
911 list_for_each_entry(ema, &lport->ema_list, ema_list) {
912 if (!ema->match || ema->match(fp)) {
913 ep = fc_exch_em_alloc(lport, ema->mp);
914 if (ep)
915 return ep;
916 }
917 }
918 return NULL;
919}
920
921/**
922 * fc_exch_find() - Lookup and hold an exchange
923 * @mp: The exchange manager to lookup the exchange from
924 * @xid: The XID of the exchange to look up
925 */
926static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
927{
928 struct fc_lport *lport = mp->lport;
929 struct fc_exch_pool *pool;
930 struct fc_exch *ep = NULL;
931 u16 cpu = xid & fc_cpu_mask;
932
933 if (xid == FC_XID_UNKNOWN)
934 return NULL;
935
936 if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
937 pr_err("host%u: lport %6.6x: xid %d invalid CPU %d\n:",
938 lport->host->host_no, lport->port_id, xid, cpu);
939 return NULL;
940 }
941
942 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
943 pool = per_cpu_ptr(mp->pool, cpu);
944 spin_lock_bh(&pool->lock);
945 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
946 if (ep == &fc_quarantine_exch) {
947 FC_LPORT_DBG(lport, "xid %x quarantined\n", xid);
948 ep = NULL;
949 }
950 if (ep) {
951 WARN_ON(ep->xid != xid);
952 fc_exch_hold(ep);
953 }
954 spin_unlock_bh(&pool->lock);
955 }
956 return ep;
957}
958
959
960/**
961 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and
962 * the memory allocated for the related objects may be freed.
963 * @sp: The sequence that has completed
964 *
965 * Note: May sleep if invoked from outside a response handler.
966 */
967void fc_exch_done(struct fc_seq *sp)
968{
969 struct fc_exch *ep = fc_seq_exch(sp);
970 int rc;
971
972 spin_lock_bh(&ep->ex_lock);
973 rc = fc_exch_done_locked(ep);
974 spin_unlock_bh(&ep->ex_lock);
975
976 fc_seq_set_resp(sp, NULL, ep->arg);
977 if (!rc)
978 fc_exch_delete(ep);
979}
980EXPORT_SYMBOL(fc_exch_done);
981
982/**
983 * fc_exch_resp() - Allocate a new exchange for a response frame
984 * @lport: The local port that the exchange was for
985 * @mp: The exchange manager to allocate the exchange from
986 * @fp: The response frame
987 *
988 * Sets the responder ID in the frame header.
989 */
990static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
991 struct fc_exch_mgr *mp,
992 struct fc_frame *fp)
993{
994 struct fc_exch *ep;
995 struct fc_frame_header *fh;
996
997 ep = fc_exch_alloc(lport, fp);
998 if (ep) {
999 ep->class = fc_frame_class(fp);
1000
1001 /*
1002 * Set EX_CTX indicating we're responding on this exchange.
1003 */
1004 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
1005 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
1006 fh = fc_frame_header_get(fp);
1007 ep->sid = ntoh24(fh->fh_d_id);
1008 ep->did = ntoh24(fh->fh_s_id);
1009 ep->oid = ep->did;
1010
1011 /*
1012 * Allocated exchange has placed the XID in the
1013 * originator field. Move it to the responder field,
1014 * and set the originator XID from the frame.
1015 */
1016 ep->rxid = ep->xid;
1017 ep->oxid = ntohs(fh->fh_ox_id);
1018 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
1019 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
1020 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
1021
1022 fc_exch_hold(ep); /* hold for caller */
1023 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
1024 }
1025 return ep;
1026}
1027
1028/**
1029 * fc_seq_lookup_recip() - Find a sequence where the other end
1030 * originated the sequence
1031 * @lport: The local port that the frame was sent to
1032 * @mp: The Exchange Manager to lookup the exchange from
1033 * @fp: The frame associated with the sequence we're looking for
1034 *
1035 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
1036 * on the ep that should be released by the caller.
1037 */
1038static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
1039 struct fc_exch_mgr *mp,
1040 struct fc_frame *fp)
1041{
1042 struct fc_frame_header *fh = fc_frame_header_get(fp);
1043 struct fc_exch *ep = NULL;
1044 struct fc_seq *sp = NULL;
1045 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
1046 u32 f_ctl;
1047 u16 xid;
1048
1049 f_ctl = ntoh24(fh->fh_f_ctl);
1050 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
1051
1052 /*
1053 * Lookup or create the exchange if we will be creating the sequence.
1054 */
1055 if (f_ctl & FC_FC_EX_CTX) {
1056 xid = ntohs(fh->fh_ox_id); /* we originated exch */
1057 ep = fc_exch_find(mp, xid);
1058 if (!ep) {
1059 atomic_inc(&mp->stats.xid_not_found);
1060 reject = FC_RJT_OX_ID;
1061 goto out;
1062 }
1063 if (ep->rxid == FC_XID_UNKNOWN)
1064 ep->rxid = ntohs(fh->fh_rx_id);
1065 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
1066 reject = FC_RJT_OX_ID;
1067 goto rel;
1068 }
1069 } else {
1070 xid = ntohs(fh->fh_rx_id); /* we are the responder */
1071
1072 /*
1073 * Special case for MDS issuing an ELS TEST with a
1074 * bad rxid of 0.
1075 * XXX take this out once we do the proper reject.
1076 */
1077 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
1078 fc_frame_payload_op(fp) == ELS_TEST) {
1079 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
1080 xid = FC_XID_UNKNOWN;
1081 }
1082
1083 /*
1084 * new sequence - find the exchange
1085 */
1086 ep = fc_exch_find(mp, xid);
1087 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
1088 if (ep) {
1089 atomic_inc(&mp->stats.xid_busy);
1090 reject = FC_RJT_RX_ID;
1091 goto rel;
1092 }
1093 ep = fc_exch_resp(lport, mp, fp);
1094 if (!ep) {
1095 reject = FC_RJT_EXCH_EST; /* XXX */
1096 goto out;
1097 }
1098 xid = ep->xid; /* get our XID */
1099 } else if (!ep) {
1100 atomic_inc(&mp->stats.xid_not_found);
1101 reject = FC_RJT_RX_ID; /* XID not found */
1102 goto out;
1103 }
1104 }
1105
1106 spin_lock_bh(&ep->ex_lock);
1107 /*
1108 * At this point, we have the exchange held.
1109 * Find or create the sequence.
1110 */
1111 if (fc_sof_is_init(fr_sof(fp))) {
1112 sp = &ep->seq;
1113 sp->ssb_stat |= SSB_ST_RESP;
1114 sp->id = fh->fh_seq_id;
1115 } else {
1116 sp = &ep->seq;
1117 if (sp->id != fh->fh_seq_id) {
1118 atomic_inc(&mp->stats.seq_not_found);
1119 if (f_ctl & FC_FC_END_SEQ) {
1120 /*
1121 * Update sequence_id based on incoming last
1122 * frame of sequence exchange. This is needed
1123 * for FC target where DDP has been used
1124 * on target where, stack is indicated only
1125 * about last frame's (payload _header) header.
1126 * Whereas "seq_id" which is part of
1127 * frame_header is allocated by initiator
1128 * which is totally different from "seq_id"
1129 * allocated when XFER_RDY was sent by target.
1130 * To avoid false -ve which results into not
1131 * sending RSP, hence write request on other
1132 * end never finishes.
1133 */
1134 sp->ssb_stat |= SSB_ST_RESP;
1135 sp->id = fh->fh_seq_id;
1136 } else {
1137 spin_unlock_bh(&ep->ex_lock);
1138
1139 /* sequence/exch should exist */
1140 reject = FC_RJT_SEQ_ID;
1141 goto rel;
1142 }
1143 }
1144 }
1145 WARN_ON(ep != fc_seq_exch(sp));
1146
1147 if (f_ctl & FC_FC_SEQ_INIT)
1148 ep->esb_stat |= ESB_ST_SEQ_INIT;
1149 spin_unlock_bh(&ep->ex_lock);
1150
1151 fr_seq(fp) = sp;
1152out:
1153 return reject;
1154rel:
1155 fc_exch_done(&ep->seq);
1156 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
1157 return reject;
1158}
1159
1160/**
1161 * fc_seq_lookup_orig() - Find a sequence where this end
1162 * originated the sequence
1163 * @mp: The Exchange Manager to lookup the exchange from
1164 * @fp: The frame associated with the sequence we're looking for
1165 *
1166 * Does not hold the sequence for the caller.
1167 */
1168static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
1169 struct fc_frame *fp)
1170{
1171 struct fc_frame_header *fh = fc_frame_header_get(fp);
1172 struct fc_exch *ep;
1173 struct fc_seq *sp = NULL;
1174 u32 f_ctl;
1175 u16 xid;
1176
1177 f_ctl = ntoh24(fh->fh_f_ctl);
1178 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
1179 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
1180 ep = fc_exch_find(mp, xid);
1181 if (!ep)
1182 return NULL;
1183 if (ep->seq.id == fh->fh_seq_id) {
1184 /*
1185 * Save the RX_ID if we didn't previously know it.
1186 */
1187 sp = &ep->seq;
1188 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
1189 ep->rxid == FC_XID_UNKNOWN) {
1190 ep->rxid = ntohs(fh->fh_rx_id);
1191 }
1192 }
1193 fc_exch_release(ep);
1194 return sp;
1195}
1196
1197/**
1198 * fc_exch_set_addr() - Set the source and destination IDs for an exchange
1199 * @ep: The exchange to set the addresses for
1200 * @orig_id: The originator's ID
1201 * @resp_id: The responder's ID
1202 *
1203 * Note this must be done before the first sequence of the exchange is sent.
1204 */
1205static void fc_exch_set_addr(struct fc_exch *ep,
1206 u32 orig_id, u32 resp_id)
1207{
1208 ep->oid = orig_id;
1209 if (ep->esb_stat & ESB_ST_RESP) {
1210 ep->sid = resp_id;
1211 ep->did = orig_id;
1212 } else {
1213 ep->sid = orig_id;
1214 ep->did = resp_id;
1215 }
1216}
1217
1218/**
1219 * fc_seq_els_rsp_send() - Send an ELS response using information from
1220 * the existing sequence/exchange.
1221 * @fp: The received frame
1222 * @els_cmd: The ELS command to be sent
1223 * @els_data: The ELS data to be sent
1224 *
1225 * The received frame is not freed.
1226 */
1227void fc_seq_els_rsp_send(struct fc_frame *fp, enum fc_els_cmd els_cmd,
1228 struct fc_seq_els_data *els_data)
1229{
1230 switch (els_cmd) {
1231 case ELS_LS_RJT:
1232 fc_seq_ls_rjt(fp, els_data->reason, els_data->explan);
1233 break;
1234 case ELS_LS_ACC:
1235 fc_seq_ls_acc(fp);
1236 break;
1237 case ELS_RRQ:
1238 fc_exch_els_rrq(fp);
1239 break;
1240 case ELS_REC:
1241 fc_exch_els_rec(fp);
1242 break;
1243 default:
1244 FC_LPORT_DBG(fr_dev(fp), "Invalid ELS CMD:%x\n", els_cmd);
1245 }
1246}
1247EXPORT_SYMBOL_GPL(fc_seq_els_rsp_send);
1248
1249/**
1250 * fc_seq_send_last() - Send a sequence that is the last in the exchange
1251 * @sp: The sequence that is to be sent
1252 * @fp: The frame that will be sent on the sequence
1253 * @rctl: The R_CTL information to be sent
1254 * @fh_type: The frame header type
1255 */
1256static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
1257 enum fc_rctl rctl, enum fc_fh_type fh_type)
1258{
1259 u32 f_ctl;
1260 struct fc_exch *ep = fc_seq_exch(sp);
1261
1262 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
1263 f_ctl |= ep->f_ctl;
1264 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
1265 fc_seq_send_locked(ep->lp, sp, fp);
1266}
1267
1268/**
1269 * fc_seq_send_ack() - Send an acknowledgement that we've received a frame
1270 * @sp: The sequence to send the ACK on
1271 * @rx_fp: The received frame that is being acknoledged
1272 *
1273 * Send ACK_1 (or equiv.) indicating we received something.
1274 */
1275static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
1276{
1277 struct fc_frame *fp;
1278 struct fc_frame_header *rx_fh;
1279 struct fc_frame_header *fh;
1280 struct fc_exch *ep = fc_seq_exch(sp);
1281 struct fc_lport *lport = ep->lp;
1282 unsigned int f_ctl;
1283
1284 /*
1285 * Don't send ACKs for class 3.
1286 */
1287 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
1288 fp = fc_frame_alloc(lport, 0);
1289 if (!fp) {
1290 FC_EXCH_DBG(ep, "Drop ACK request, out of memory\n");
1291 return;
1292 }
1293
1294 fh = fc_frame_header_get(fp);
1295 fh->fh_r_ctl = FC_RCTL_ACK_1;
1296 fh->fh_type = FC_TYPE_BLS;
1297
1298 /*
1299 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1300 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1301 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1302 * Last ACK uses bits 7-6 (continue sequence),
1303 * bits 5-4 are meaningful (what kind of ACK to use).
1304 */
1305 rx_fh = fc_frame_header_get(rx_fp);
1306 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1307 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1308 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
1309 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
1310 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1311 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1312 hton24(fh->fh_f_ctl, f_ctl);
1313
1314 fc_exch_setup_hdr(ep, fp, f_ctl);
1315 fh->fh_seq_id = rx_fh->fh_seq_id;
1316 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1317 fh->fh_parm_offset = htonl(1); /* ack single frame */
1318
1319 fr_sof(fp) = fr_sof(rx_fp);
1320 if (f_ctl & FC_FC_END_SEQ)
1321 fr_eof(fp) = FC_EOF_T;
1322 else
1323 fr_eof(fp) = FC_EOF_N;
1324
1325 lport->tt.frame_send(lport, fp);
1326 }
1327}
1328
1329/**
1330 * fc_exch_send_ba_rjt() - Send BLS Reject
1331 * @rx_fp: The frame being rejected
1332 * @reason: The reason the frame is being rejected
1333 * @explan: The explanation for the rejection
1334 *
1335 * This is for rejecting BA_ABTS only.
1336 */
1337static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
1338 enum fc_ba_rjt_reason reason,
1339 enum fc_ba_rjt_explan explan)
1340{
1341 struct fc_frame *fp;
1342 struct fc_frame_header *rx_fh;
1343 struct fc_frame_header *fh;
1344 struct fc_ba_rjt *rp;
1345 struct fc_seq *sp;
1346 struct fc_lport *lport;
1347 unsigned int f_ctl;
1348
1349 lport = fr_dev(rx_fp);
1350 sp = fr_seq(rx_fp);
1351 fp = fc_frame_alloc(lport, sizeof(*rp));
1352 if (!fp) {
1353 FC_EXCH_DBG(fc_seq_exch(sp),
1354 "Drop BA_RJT request, out of memory\n");
1355 return;
1356 }
1357 fh = fc_frame_header_get(fp);
1358 rx_fh = fc_frame_header_get(rx_fp);
1359
1360 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1361
1362 rp = fc_frame_payload_get(fp, sizeof(*rp));
1363 rp->br_reason = reason;
1364 rp->br_explan = explan;
1365
1366 /*
1367 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1368 */
1369 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1370 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1371 fh->fh_ox_id = rx_fh->fh_ox_id;
1372 fh->fh_rx_id = rx_fh->fh_rx_id;
1373 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1374 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1375 fh->fh_type = FC_TYPE_BLS;
1376
1377 /*
1378 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1379 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1380 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1381 * Last ACK uses bits 7-6 (continue sequence),
1382 * bits 5-4 are meaningful (what kind of ACK to use).
1383 * Always set LAST_SEQ, END_SEQ.
1384 */
1385 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1386 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1387 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1388 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1389 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1390 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1391 f_ctl &= ~FC_FC_FIRST_SEQ;
1392 hton24(fh->fh_f_ctl, f_ctl);
1393
1394 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1395 fr_eof(fp) = FC_EOF_T;
1396 if (fc_sof_needs_ack(fr_sof(fp)))
1397 fr_eof(fp) = FC_EOF_N;
1398
1399 lport->tt.frame_send(lport, fp);
1400}
1401
1402/**
1403 * fc_exch_recv_abts() - Handle an incoming ABTS
1404 * @ep: The exchange the abort was on
1405 * @rx_fp: The ABTS frame
1406 *
1407 * This would be for target mode usually, but could be due to lost
1408 * FCP transfer ready, confirm or RRQ. We always handle this as an
1409 * exchange abort, ignoring the parameter.
1410 */
1411static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1412{
1413 struct fc_frame *fp;
1414 struct fc_ba_acc *ap;
1415 struct fc_frame_header *fh;
1416 struct fc_seq *sp;
1417
1418 if (!ep)
1419 goto reject;
1420
1421 FC_EXCH_DBG(ep, "exch: ABTS received\n");
1422 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1423 if (!fp) {
1424 FC_EXCH_DBG(ep, "Drop ABTS request, out of memory\n");
1425 goto free;
1426 }
1427
1428 spin_lock_bh(&ep->ex_lock);
1429 if (ep->esb_stat & ESB_ST_COMPLETE) {
1430 spin_unlock_bh(&ep->ex_lock);
1431 FC_EXCH_DBG(ep, "exch: ABTS rejected, exchange complete\n");
1432 fc_frame_free(fp);
1433 goto reject;
1434 }
1435 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
1436 ep->esb_stat |= ESB_ST_REC_QUAL;
1437 fc_exch_hold(ep); /* hold for REC_QUAL */
1438 }
1439 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1440 fh = fc_frame_header_get(fp);
1441 ap = fc_frame_payload_get(fp, sizeof(*ap));
1442 memset(ap, 0, sizeof(*ap));
1443 sp = &ep->seq;
1444 ap->ba_high_seq_cnt = htons(0xffff);
1445 if (sp->ssb_stat & SSB_ST_RESP) {
1446 ap->ba_seq_id = sp->id;
1447 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1448 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1449 ap->ba_low_seq_cnt = htons(sp->cnt);
1450 }
1451 sp = fc_seq_start_next_locked(sp);
1452 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1453 ep->esb_stat |= ESB_ST_ABNORMAL;
1454 spin_unlock_bh(&ep->ex_lock);
1455
1456free:
1457 fc_frame_free(rx_fp);
1458 return;
1459
1460reject:
1461 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1462 goto free;
1463}
1464
1465/**
1466 * fc_seq_assign() - Assign exchange and sequence for incoming request
1467 * @lport: The local port that received the request
1468 * @fp: The request frame
1469 *
1470 * On success, the sequence pointer will be returned and also in fr_seq(@fp).
1471 * A reference will be held on the exchange/sequence for the caller, which
1472 * must call fc_seq_release().
1473 */
1474struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)
1475{
1476 struct fc_exch_mgr_anchor *ema;
1477
1478 WARN_ON(lport != fr_dev(fp));
1479 WARN_ON(fr_seq(fp));
1480 fr_seq(fp) = NULL;
1481
1482 list_for_each_entry(ema, &lport->ema_list, ema_list)
1483 if ((!ema->match || ema->match(fp)) &&
1484 fc_seq_lookup_recip(lport, ema->mp, fp) == FC_RJT_NONE)
1485 break;
1486 return fr_seq(fp);
1487}
1488EXPORT_SYMBOL(fc_seq_assign);
1489
1490/**
1491 * fc_seq_release() - Release the hold
1492 * @sp: The sequence.
1493 */
1494void fc_seq_release(struct fc_seq *sp)
1495{
1496 fc_exch_release(fc_seq_exch(sp));
1497}
1498EXPORT_SYMBOL(fc_seq_release);
1499
1500/**
1501 * fc_exch_recv_req() - Handler for an incoming request
1502 * @lport: The local port that received the request
1503 * @mp: The EM that the exchange is on
1504 * @fp: The request frame
1505 *
1506 * This is used when the other end is originating the exchange
1507 * and the sequence.
1508 */
1509static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp,
1510 struct fc_frame *fp)
1511{
1512 struct fc_frame_header *fh = fc_frame_header_get(fp);
1513 struct fc_seq *sp = NULL;
1514 struct fc_exch *ep = NULL;
1515 enum fc_pf_rjt_reason reject;
1516
1517 /* We can have the wrong fc_lport at this point with NPIV, which is a
1518 * problem now that we know a new exchange needs to be allocated
1519 */
1520 lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id));
1521 if (!lport) {
1522 fc_frame_free(fp);
1523 return;
1524 }
1525 fr_dev(fp) = lport;
1526
1527 BUG_ON(fr_seq(fp)); /* XXX remove later */
1528
1529 /*
1530 * If the RX_ID is 0xffff, don't allocate an exchange.
1531 * The upper-level protocol may request one later, if needed.
1532 */
1533 if (fh->fh_rx_id == htons(FC_XID_UNKNOWN))
1534 return fc_lport_recv(lport, fp);
1535
1536 reject = fc_seq_lookup_recip(lport, mp, fp);
1537 if (reject == FC_RJT_NONE) {
1538 sp = fr_seq(fp); /* sequence will be held */
1539 ep = fc_seq_exch(sp);
1540 fc_seq_send_ack(sp, fp);
1541 ep->encaps = fr_encaps(fp);
1542
1543 /*
1544 * Call the receive function.
1545 *
1546 * The receive function may allocate a new sequence
1547 * over the old one, so we shouldn't change the
1548 * sequence after this.
1549 *
1550 * The frame will be freed by the receive function.
1551 * If new exch resp handler is valid then call that
1552 * first.
1553 */
1554 if (!fc_invoke_resp(ep, sp, fp))
1555 fc_lport_recv(lport, fp);
1556 fc_exch_release(ep); /* release from lookup */
1557 } else {
1558 FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n",
1559 reject);
1560 fc_frame_free(fp);
1561 }
1562}
1563
1564/**
1565 * fc_exch_recv_seq_resp() - Handler for an incoming response where the other
1566 * end is the originator of the sequence that is a
1567 * response to our initial exchange
1568 * @mp: The EM that the exchange is on
1569 * @fp: The response frame
1570 */
1571static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1572{
1573 struct fc_frame_header *fh = fc_frame_header_get(fp);
1574 struct fc_seq *sp;
1575 struct fc_exch *ep;
1576 enum fc_sof sof;
1577 u32 f_ctl;
1578 int rc;
1579
1580 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1581 if (!ep) {
1582 atomic_inc(&mp->stats.xid_not_found);
1583 goto out;
1584 }
1585 if (ep->esb_stat & ESB_ST_COMPLETE) {
1586 atomic_inc(&mp->stats.xid_not_found);
1587 goto rel;
1588 }
1589 if (ep->rxid == FC_XID_UNKNOWN)
1590 ep->rxid = ntohs(fh->fh_rx_id);
1591 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1592 atomic_inc(&mp->stats.xid_not_found);
1593 goto rel;
1594 }
1595 if (ep->did != ntoh24(fh->fh_s_id) &&
1596 ep->did != FC_FID_FLOGI) {
1597 atomic_inc(&mp->stats.xid_not_found);
1598 goto rel;
1599 }
1600 sof = fr_sof(fp);
1601 sp = &ep->seq;
1602 if (fc_sof_is_init(sof)) {
1603 sp->ssb_stat |= SSB_ST_RESP;
1604 sp->id = fh->fh_seq_id;
1605 }
1606
1607 f_ctl = ntoh24(fh->fh_f_ctl);
1608 fr_seq(fp) = sp;
1609
1610 spin_lock_bh(&ep->ex_lock);
1611 if (f_ctl & FC_FC_SEQ_INIT)
1612 ep->esb_stat |= ESB_ST_SEQ_INIT;
1613 spin_unlock_bh(&ep->ex_lock);
1614
1615 if (fc_sof_needs_ack(sof))
1616 fc_seq_send_ack(sp, fp);
1617
1618 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1619 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1620 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1621 spin_lock_bh(&ep->ex_lock);
1622 rc = fc_exch_done_locked(ep);
1623 WARN_ON(fc_seq_exch(sp) != ep);
1624 spin_unlock_bh(&ep->ex_lock);
1625 if (!rc) {
1626 fc_exch_delete(ep);
1627 } else {
1628 FC_EXCH_DBG(ep, "ep is completed already,"
1629 "hence skip calling the resp\n");
1630 goto skip_resp;
1631 }
1632 }
1633
1634 /*
1635 * Call the receive function.
1636 * The sequence is held (has a refcnt) for us,
1637 * but not for the receive function.
1638 *
1639 * The receive function may allocate a new sequence
1640 * over the old one, so we shouldn't change the
1641 * sequence after this.
1642 *
1643 * The frame will be freed by the receive function.
1644 * If new exch resp handler is valid then call that
1645 * first.
1646 */
1647 if (!fc_invoke_resp(ep, sp, fp))
1648 fc_frame_free(fp);
1649
1650skip_resp:
1651 fc_exch_release(ep);
1652 return;
1653rel:
1654 fc_exch_release(ep);
1655out:
1656 fc_frame_free(fp);
1657}
1658
1659/**
1660 * fc_exch_recv_resp() - Handler for a sequence where other end is
1661 * responding to our sequence
1662 * @mp: The EM that the exchange is on
1663 * @fp: The response frame
1664 */
1665static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1666{
1667 struct fc_seq *sp;
1668
1669 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1670
1671 if (!sp)
1672 atomic_inc(&mp->stats.xid_not_found);
1673 else
1674 atomic_inc(&mp->stats.non_bls_resp);
1675
1676 fc_frame_free(fp);
1677}
1678
1679/**
1680 * fc_exch_abts_resp() - Handler for a response to an ABT
1681 * @ep: The exchange that the frame is on
1682 * @fp: The response frame
1683 *
1684 * This response would be to an ABTS cancelling an exchange or sequence.
1685 * The response can be either BA_ACC or BA_RJT
1686 */
1687static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1688{
1689 struct fc_frame_header *fh;
1690 struct fc_ba_acc *ap;
1691 struct fc_seq *sp;
1692 u16 low;
1693 u16 high;
1694 int rc = 1, has_rec = 0;
1695
1696 fh = fc_frame_header_get(fp);
1697 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1698 fc_exch_rctl_name(fh->fh_r_ctl));
1699
1700 if (cancel_delayed_work_sync(&ep->timeout_work)) {
1701 FC_EXCH_DBG(ep, "Exchange timer canceled due to ABTS response\n");
1702 fc_exch_release(ep); /* release from pending timer hold */
1703 return;
1704 }
1705
1706 spin_lock_bh(&ep->ex_lock);
1707 switch (fh->fh_r_ctl) {
1708 case FC_RCTL_BA_ACC:
1709 ap = fc_frame_payload_get(fp, sizeof(*ap));
1710 if (!ap)
1711 break;
1712
1713 /*
1714 * Decide whether to establish a Recovery Qualifier.
1715 * We do this if there is a non-empty SEQ_CNT range and
1716 * SEQ_ID is the same as the one we aborted.
1717 */
1718 low = ntohs(ap->ba_low_seq_cnt);
1719 high = ntohs(ap->ba_high_seq_cnt);
1720 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1721 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1722 ap->ba_seq_id == ep->seq_id) && low != high) {
1723 ep->esb_stat |= ESB_ST_REC_QUAL;
1724 fc_exch_hold(ep); /* hold for recovery qualifier */
1725 has_rec = 1;
1726 }
1727 break;
1728 case FC_RCTL_BA_RJT:
1729 break;
1730 default:
1731 break;
1732 }
1733
1734 /* do we need to do some other checks here. Can we reuse more of
1735 * fc_exch_recv_seq_resp
1736 */
1737 sp = &ep->seq;
1738 /*
1739 * do we want to check END_SEQ as well as LAST_SEQ here?
1740 */
1741 if (ep->fh_type != FC_TYPE_FCP &&
1742 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1743 rc = fc_exch_done_locked(ep);
1744 spin_unlock_bh(&ep->ex_lock);
1745
1746 fc_exch_hold(ep);
1747 if (!rc)
1748 fc_exch_delete(ep);
1749 if (!fc_invoke_resp(ep, sp, fp))
1750 fc_frame_free(fp);
1751 if (has_rec)
1752 fc_exch_timer_set(ep, ep->r_a_tov);
1753 fc_exch_release(ep);
1754}
1755
1756/**
1757 * fc_exch_recv_bls() - Handler for a BLS sequence
1758 * @mp: The EM that the exchange is on
1759 * @fp: The request frame
1760 *
1761 * The BLS frame is always a sequence initiated by the remote side.
1762 * We may be either the originator or recipient of the exchange.
1763 */
1764static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1765{
1766 struct fc_frame_header *fh;
1767 struct fc_exch *ep;
1768 u32 f_ctl;
1769
1770 fh = fc_frame_header_get(fp);
1771 f_ctl = ntoh24(fh->fh_f_ctl);
1772 fr_seq(fp) = NULL;
1773
1774 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1775 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1776 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1777 spin_lock_bh(&ep->ex_lock);
1778 ep->esb_stat |= ESB_ST_SEQ_INIT;
1779 spin_unlock_bh(&ep->ex_lock);
1780 }
1781 if (f_ctl & FC_FC_SEQ_CTX) {
1782 /*
1783 * A response to a sequence we initiated.
1784 * This should only be ACKs for class 2 or F.
1785 */
1786 switch (fh->fh_r_ctl) {
1787 case FC_RCTL_ACK_1:
1788 case FC_RCTL_ACK_0:
1789 break;
1790 default:
1791 if (ep)
1792 FC_EXCH_DBG(ep, "BLS rctl %x - %s received\n",
1793 fh->fh_r_ctl,
1794 fc_exch_rctl_name(fh->fh_r_ctl));
1795 break;
1796 }
1797 fc_frame_free(fp);
1798 } else {
1799 switch (fh->fh_r_ctl) {
1800 case FC_RCTL_BA_RJT:
1801 case FC_RCTL_BA_ACC:
1802 if (ep)
1803 fc_exch_abts_resp(ep, fp);
1804 else
1805 fc_frame_free(fp);
1806 break;
1807 case FC_RCTL_BA_ABTS:
1808 if (ep)
1809 fc_exch_recv_abts(ep, fp);
1810 else
1811 fc_frame_free(fp);
1812 break;
1813 default: /* ignore junk */
1814 fc_frame_free(fp);
1815 break;
1816 }
1817 }
1818 if (ep)
1819 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1820}
1821
1822/**
1823 * fc_seq_ls_acc() - Accept sequence with LS_ACC
1824 * @rx_fp: The received frame, not freed here.
1825 *
1826 * If this fails due to allocation or transmit congestion, assume the
1827 * originator will repeat the sequence.
1828 */
1829static void fc_seq_ls_acc(struct fc_frame *rx_fp)
1830{
1831 struct fc_lport *lport;
1832 struct fc_els_ls_acc *acc;
1833 struct fc_frame *fp;
1834 struct fc_seq *sp;
1835
1836 lport = fr_dev(rx_fp);
1837 sp = fr_seq(rx_fp);
1838 fp = fc_frame_alloc(lport, sizeof(*acc));
1839 if (!fp) {
1840 FC_EXCH_DBG(fc_seq_exch(sp),
1841 "exch: drop LS_ACC, out of memory\n");
1842 return;
1843 }
1844 acc = fc_frame_payload_get(fp, sizeof(*acc));
1845 memset(acc, 0, sizeof(*acc));
1846 acc->la_cmd = ELS_LS_ACC;
1847 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1848 lport->tt.frame_send(lport, fp);
1849}
1850
1851/**
1852 * fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT
1853 * @rx_fp: The received frame, not freed here.
1854 * @reason: The reason the sequence is being rejected
1855 * @explan: The explanation for the rejection
1856 *
1857 * If this fails due to allocation or transmit congestion, assume the
1858 * originator will repeat the sequence.
1859 */
1860static void fc_seq_ls_rjt(struct fc_frame *rx_fp, enum fc_els_rjt_reason reason,
1861 enum fc_els_rjt_explan explan)
1862{
1863 struct fc_lport *lport;
1864 struct fc_els_ls_rjt *rjt;
1865 struct fc_frame *fp;
1866 struct fc_seq *sp;
1867
1868 lport = fr_dev(rx_fp);
1869 sp = fr_seq(rx_fp);
1870 fp = fc_frame_alloc(lport, sizeof(*rjt));
1871 if (!fp) {
1872 FC_EXCH_DBG(fc_seq_exch(sp),
1873 "exch: drop LS_ACC, out of memory\n");
1874 return;
1875 }
1876 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1877 memset(rjt, 0, sizeof(*rjt));
1878 rjt->er_cmd = ELS_LS_RJT;
1879 rjt->er_reason = reason;
1880 rjt->er_explan = explan;
1881 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1882 lport->tt.frame_send(lport, fp);
1883}
1884
1885/**
1886 * fc_exch_reset() - Reset an exchange
1887 * @ep: The exchange to be reset
1888 *
1889 * Note: May sleep if invoked from outside a response handler.
1890 */
1891static void fc_exch_reset(struct fc_exch *ep)
1892{
1893 struct fc_seq *sp;
1894 int rc = 1;
1895
1896 spin_lock_bh(&ep->ex_lock);
1897 ep->state |= FC_EX_RST_CLEANUP;
1898 fc_exch_timer_cancel(ep);
1899 if (ep->esb_stat & ESB_ST_REC_QUAL)
1900 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1901 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1902 sp = &ep->seq;
1903 rc = fc_exch_done_locked(ep);
1904 spin_unlock_bh(&ep->ex_lock);
1905
1906 fc_exch_hold(ep);
1907
1908 if (!rc) {
1909 fc_exch_delete(ep);
1910 } else {
1911 FC_EXCH_DBG(ep, "ep is completed already,"
1912 "hence skip calling the resp\n");
1913 goto skip_resp;
1914 }
1915
1916 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_CLOSED));
1917skip_resp:
1918 fc_seq_set_resp(sp, NULL, ep->arg);
1919 fc_exch_release(ep);
1920}
1921
1922/**
1923 * fc_exch_pool_reset() - Reset a per cpu exchange pool
1924 * @lport: The local port that the exchange pool is on
1925 * @pool: The exchange pool to be reset
1926 * @sid: The source ID
1927 * @did: The destination ID
1928 *
1929 * Resets a per cpu exches pool, releasing all of its sequences
1930 * and exchanges. If sid is non-zero then reset only exchanges
1931 * we sourced from the local port's FID. If did is non-zero then
1932 * only reset exchanges destined for the local port's FID.
1933 */
1934static void fc_exch_pool_reset(struct fc_lport *lport,
1935 struct fc_exch_pool *pool,
1936 u32 sid, u32 did)
1937{
1938 struct fc_exch *ep;
1939 struct fc_exch *next;
1940
1941 spin_lock_bh(&pool->lock);
1942restart:
1943 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1944 if ((lport == ep->lp) &&
1945 (sid == 0 || sid == ep->sid) &&
1946 (did == 0 || did == ep->did)) {
1947 fc_exch_hold(ep);
1948 spin_unlock_bh(&pool->lock);
1949
1950 fc_exch_reset(ep);
1951
1952 fc_exch_release(ep);
1953 spin_lock_bh(&pool->lock);
1954
1955 /*
1956 * must restart loop incase while lock
1957 * was down multiple eps were released.
1958 */
1959 goto restart;
1960 }
1961 }
1962 pool->next_index = 0;
1963 pool->left = FC_XID_UNKNOWN;
1964 pool->right = FC_XID_UNKNOWN;
1965 spin_unlock_bh(&pool->lock);
1966}
1967
1968/**
1969 * fc_exch_mgr_reset() - Reset all EMs of a local port
1970 * @lport: The local port whose EMs are to be reset
1971 * @sid: The source ID
1972 * @did: The destination ID
1973 *
1974 * Reset all EMs associated with a given local port. Release all
1975 * sequences and exchanges. If sid is non-zero then reset only the
1976 * exchanges sent from the local port's FID. If did is non-zero then
1977 * reset only exchanges destined for the local port's FID.
1978 */
1979void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1980{
1981 struct fc_exch_mgr_anchor *ema;
1982 unsigned int cpu;
1983
1984 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1985 for_each_possible_cpu(cpu)
1986 fc_exch_pool_reset(lport,
1987 per_cpu_ptr(ema->mp->pool, cpu),
1988 sid, did);
1989 }
1990}
1991EXPORT_SYMBOL(fc_exch_mgr_reset);
1992
1993/**
1994 * fc_exch_lookup() - find an exchange
1995 * @lport: The local port
1996 * @xid: The exchange ID
1997 *
1998 * Returns exchange pointer with hold for caller, or NULL if not found.
1999 */
2000static struct fc_exch *fc_exch_lookup(struct fc_lport *lport, u32 xid)
2001{
2002 struct fc_exch_mgr_anchor *ema;
2003
2004 list_for_each_entry(ema, &lport->ema_list, ema_list)
2005 if (ema->mp->min_xid <= xid && xid <= ema->mp->max_xid)
2006 return fc_exch_find(ema->mp, xid);
2007 return NULL;
2008}
2009
2010/**
2011 * fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests
2012 * @rfp: The REC frame, not freed here.
2013 *
2014 * Note that the requesting port may be different than the S_ID in the request.
2015 */
2016static void fc_exch_els_rec(struct fc_frame *rfp)
2017{
2018 struct fc_lport *lport;
2019 struct fc_frame *fp;
2020 struct fc_exch *ep;
2021 struct fc_els_rec *rp;
2022 struct fc_els_rec_acc *acc;
2023 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
2024 enum fc_els_rjt_explan explan;
2025 u32 sid;
2026 u16 xid, rxid, oxid;
2027
2028 lport = fr_dev(rfp);
2029 rp = fc_frame_payload_get(rfp, sizeof(*rp));
2030 explan = ELS_EXPL_INV_LEN;
2031 if (!rp)
2032 goto reject;
2033 sid = ntoh24(rp->rec_s_id);
2034 rxid = ntohs(rp->rec_rx_id);
2035 oxid = ntohs(rp->rec_ox_id);
2036
2037 explan = ELS_EXPL_OXID_RXID;
2038 if (sid == fc_host_port_id(lport->host))
2039 xid = oxid;
2040 else
2041 xid = rxid;
2042 if (xid == FC_XID_UNKNOWN) {
2043 FC_LPORT_DBG(lport,
2044 "REC request from %x: invalid rxid %x oxid %x\n",
2045 sid, rxid, oxid);
2046 goto reject;
2047 }
2048 ep = fc_exch_lookup(lport, xid);
2049 if (!ep) {
2050 FC_LPORT_DBG(lport,
2051 "REC request from %x: rxid %x oxid %x not found\n",
2052 sid, rxid, oxid);
2053 goto reject;
2054 }
2055 FC_EXCH_DBG(ep, "REC request from %x: rxid %x oxid %x\n",
2056 sid, rxid, oxid);
2057 if (ep->oid != sid || oxid != ep->oxid)
2058 goto rel;
2059 if (rxid != FC_XID_UNKNOWN && rxid != ep->rxid)
2060 goto rel;
2061 fp = fc_frame_alloc(lport, sizeof(*acc));
2062 if (!fp) {
2063 FC_EXCH_DBG(ep, "Drop REC request, out of memory\n");
2064 goto out;
2065 }
2066
2067 acc = fc_frame_payload_get(fp, sizeof(*acc));
2068 memset(acc, 0, sizeof(*acc));
2069 acc->reca_cmd = ELS_LS_ACC;
2070 acc->reca_ox_id = rp->rec_ox_id;
2071 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
2072 acc->reca_rx_id = htons(ep->rxid);
2073 if (ep->sid == ep->oid)
2074 hton24(acc->reca_rfid, ep->did);
2075 else
2076 hton24(acc->reca_rfid, ep->sid);
2077 acc->reca_fc4value = htonl(ep->seq.rec_data);
2078 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
2079 ESB_ST_SEQ_INIT |
2080 ESB_ST_COMPLETE));
2081 fc_fill_reply_hdr(fp, rfp, FC_RCTL_ELS_REP, 0);
2082 lport->tt.frame_send(lport, fp);
2083out:
2084 fc_exch_release(ep);
2085 return;
2086
2087rel:
2088 fc_exch_release(ep);
2089reject:
2090 fc_seq_ls_rjt(rfp, reason, explan);
2091}
2092
2093/**
2094 * fc_exch_rrq_resp() - Handler for RRQ responses
2095 * @sp: The sequence that the RRQ is on
2096 * @fp: The RRQ frame
2097 * @arg: The exchange that the RRQ is on
2098 *
2099 * TODO: fix error handler.
2100 */
2101static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
2102{
2103 struct fc_exch *aborted_ep = arg;
2104 unsigned int op;
2105
2106 if (IS_ERR(fp)) {
2107 int err = PTR_ERR(fp);
2108
2109 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
2110 goto cleanup;
2111 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
2112 "frame error %d\n", err);
2113 return;
2114 }
2115
2116 op = fc_frame_payload_op(fp);
2117 fc_frame_free(fp);
2118
2119 switch (op) {
2120 case ELS_LS_RJT:
2121 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ\n");
2122 fallthrough;
2123 case ELS_LS_ACC:
2124 goto cleanup;
2125 default:
2126 FC_EXCH_DBG(aborted_ep, "unexpected response op %x for RRQ\n",
2127 op);
2128 return;
2129 }
2130
2131cleanup:
2132 fc_exch_done(&aborted_ep->seq);
2133 /* drop hold for rec qual */
2134 fc_exch_release(aborted_ep);
2135}
2136
2137
2138/**
2139 * fc_exch_seq_send() - Send a frame using a new exchange and sequence
2140 * @lport: The local port to send the frame on
2141 * @fp: The frame to be sent
2142 * @resp: The response handler for this request
2143 * @destructor: The destructor for the exchange
2144 * @arg: The argument to be passed to the response handler
2145 * @timer_msec: The timeout period for the exchange
2146 *
2147 * The exchange response handler is set in this routine to resp()
2148 * function pointer. It can be called in two scenarios: if a timeout
2149 * occurs or if a response frame is received for the exchange. The
2150 * fc_frame pointer in response handler will also indicate timeout
2151 * as error using IS_ERR related macros.
2152 *
2153 * The exchange destructor handler is also set in this routine.
2154 * The destructor handler is invoked by EM layer when exchange
2155 * is about to free, this can be used by caller to free its
2156 * resources along with exchange free.
2157 *
2158 * The arg is passed back to resp and destructor handler.
2159 *
2160 * The timeout value (in msec) for an exchange is set if non zero
2161 * timer_msec argument is specified. The timer is canceled when
2162 * it fires or when the exchange is done. The exchange timeout handler
2163 * is registered by EM layer.
2164 *
2165 * The frame pointer with some of the header's fields must be
2166 * filled before calling this routine, those fields are:
2167 *
2168 * - routing control
2169 * - FC port did
2170 * - FC port sid
2171 * - FC header type
2172 * - frame control
2173 * - parameter or relative offset
2174 */
2175struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
2176 struct fc_frame *fp,
2177 void (*resp)(struct fc_seq *,
2178 struct fc_frame *fp,
2179 void *arg),
2180 void (*destructor)(struct fc_seq *, void *),
2181 void *arg, u32 timer_msec)
2182{
2183 struct fc_exch *ep;
2184 struct fc_seq *sp = NULL;
2185 struct fc_frame_header *fh;
2186 struct fc_fcp_pkt *fsp = NULL;
2187 int rc = 1;
2188
2189 ep = fc_exch_alloc(lport, fp);
2190 if (!ep) {
2191 fc_frame_free(fp);
2192 return NULL;
2193 }
2194 ep->esb_stat |= ESB_ST_SEQ_INIT;
2195 fh = fc_frame_header_get(fp);
2196 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
2197 ep->resp = resp;
2198 ep->destructor = destructor;
2199 ep->arg = arg;
2200 ep->r_a_tov = lport->r_a_tov;
2201 ep->lp = lport;
2202 sp = &ep->seq;
2203
2204 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
2205 ep->f_ctl = ntoh24(fh->fh_f_ctl);
2206 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
2207 sp->cnt++;
2208
2209 if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD) {
2210 fsp = fr_fsp(fp);
2211 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
2212 }
2213
2214 if (unlikely(lport->tt.frame_send(lport, fp)))
2215 goto err;
2216
2217 if (timer_msec)
2218 fc_exch_timer_set_locked(ep, timer_msec);
2219 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
2220
2221 if (ep->f_ctl & FC_FC_SEQ_INIT)
2222 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
2223 spin_unlock_bh(&ep->ex_lock);
2224 return sp;
2225err:
2226 if (fsp)
2227 fc_fcp_ddp_done(fsp);
2228 rc = fc_exch_done_locked(ep);
2229 spin_unlock_bh(&ep->ex_lock);
2230 if (!rc)
2231 fc_exch_delete(ep);
2232 return NULL;
2233}
2234EXPORT_SYMBOL(fc_exch_seq_send);
2235
2236/**
2237 * fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command
2238 * @ep: The exchange to send the RRQ on
2239 *
2240 * This tells the remote port to stop blocking the use of
2241 * the exchange and the seq_cnt range.
2242 */
2243static void fc_exch_rrq(struct fc_exch *ep)
2244{
2245 struct fc_lport *lport;
2246 struct fc_els_rrq *rrq;
2247 struct fc_frame *fp;
2248 u32 did;
2249
2250 lport = ep->lp;
2251
2252 fp = fc_frame_alloc(lport, sizeof(*rrq));
2253 if (!fp)
2254 goto retry;
2255
2256 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
2257 memset(rrq, 0, sizeof(*rrq));
2258 rrq->rrq_cmd = ELS_RRQ;
2259 hton24(rrq->rrq_s_id, ep->sid);
2260 rrq->rrq_ox_id = htons(ep->oxid);
2261 rrq->rrq_rx_id = htons(ep->rxid);
2262
2263 did = ep->did;
2264 if (ep->esb_stat & ESB_ST_RESP)
2265 did = ep->sid;
2266
2267 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
2268 lport->port_id, FC_TYPE_ELS,
2269 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
2270
2271 if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep,
2272 lport->e_d_tov))
2273 return;
2274
2275retry:
2276 FC_EXCH_DBG(ep, "exch: RRQ send failed\n");
2277 spin_lock_bh(&ep->ex_lock);
2278 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
2279 spin_unlock_bh(&ep->ex_lock);
2280 /* drop hold for rec qual */
2281 fc_exch_release(ep);
2282 return;
2283 }
2284 ep->esb_stat |= ESB_ST_REC_QUAL;
2285 fc_exch_timer_set_locked(ep, ep->r_a_tov);
2286 spin_unlock_bh(&ep->ex_lock);
2287}
2288
2289/**
2290 * fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests
2291 * @fp: The RRQ frame, not freed here.
2292 */
2293static void fc_exch_els_rrq(struct fc_frame *fp)
2294{
2295 struct fc_lport *lport;
2296 struct fc_exch *ep = NULL; /* request or subject exchange */
2297 struct fc_els_rrq *rp;
2298 u32 sid;
2299 u16 xid;
2300 enum fc_els_rjt_explan explan;
2301
2302 lport = fr_dev(fp);
2303 rp = fc_frame_payload_get(fp, sizeof(*rp));
2304 explan = ELS_EXPL_INV_LEN;
2305 if (!rp)
2306 goto reject;
2307
2308 /*
2309 * lookup subject exchange.
2310 */
2311 sid = ntoh24(rp->rrq_s_id); /* subject source */
2312 xid = fc_host_port_id(lport->host) == sid ?
2313 ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
2314 ep = fc_exch_lookup(lport, xid);
2315 explan = ELS_EXPL_OXID_RXID;
2316 if (!ep)
2317 goto reject;
2318 spin_lock_bh(&ep->ex_lock);
2319 FC_EXCH_DBG(ep, "RRQ request from %x: xid %x rxid %x oxid %x\n",
2320 sid, xid, ntohs(rp->rrq_rx_id), ntohs(rp->rrq_ox_id));
2321 if (ep->oxid != ntohs(rp->rrq_ox_id))
2322 goto unlock_reject;
2323 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
2324 ep->rxid != FC_XID_UNKNOWN)
2325 goto unlock_reject;
2326 explan = ELS_EXPL_SID;
2327 if (ep->sid != sid)
2328 goto unlock_reject;
2329
2330 /*
2331 * Clear Recovery Qualifier state, and cancel timer if complete.
2332 */
2333 if (ep->esb_stat & ESB_ST_REC_QUAL) {
2334 ep->esb_stat &= ~ESB_ST_REC_QUAL;
2335 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
2336 }
2337 if (ep->esb_stat & ESB_ST_COMPLETE)
2338 fc_exch_timer_cancel(ep);
2339
2340 spin_unlock_bh(&ep->ex_lock);
2341
2342 /*
2343 * Send LS_ACC.
2344 */
2345 fc_seq_ls_acc(fp);
2346 goto out;
2347
2348unlock_reject:
2349 spin_unlock_bh(&ep->ex_lock);
2350reject:
2351 fc_seq_ls_rjt(fp, ELS_RJT_LOGIC, explan);
2352out:
2353 if (ep)
2354 fc_exch_release(ep); /* drop hold from fc_exch_find */
2355}
2356
2357/**
2358 * fc_exch_update_stats() - update exches stats to lport
2359 * @lport: The local port to update exchange manager stats
2360 */
2361void fc_exch_update_stats(struct fc_lport *lport)
2362{
2363 struct fc_host_statistics *st;
2364 struct fc_exch_mgr_anchor *ema;
2365 struct fc_exch_mgr *mp;
2366
2367 st = &lport->host_stats;
2368
2369 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2370 mp = ema->mp;
2371 st->fc_no_free_exch += atomic_read(&mp->stats.no_free_exch);
2372 st->fc_no_free_exch_xid +=
2373 atomic_read(&mp->stats.no_free_exch_xid);
2374 st->fc_xid_not_found += atomic_read(&mp->stats.xid_not_found);
2375 st->fc_xid_busy += atomic_read(&mp->stats.xid_busy);
2376 st->fc_seq_not_found += atomic_read(&mp->stats.seq_not_found);
2377 st->fc_non_bls_resp += atomic_read(&mp->stats.non_bls_resp);
2378 }
2379}
2380EXPORT_SYMBOL(fc_exch_update_stats);
2381
2382/**
2383 * fc_exch_mgr_add() - Add an exchange manager to a local port's list of EMs
2384 * @lport: The local port to add the exchange manager to
2385 * @mp: The exchange manager to be added to the local port
2386 * @match: The match routine that indicates when this EM should be used
2387 */
2388struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
2389 struct fc_exch_mgr *mp,
2390 bool (*match)(struct fc_frame *))
2391{
2392 struct fc_exch_mgr_anchor *ema;
2393
2394 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
2395 if (!ema)
2396 return ema;
2397
2398 ema->mp = mp;
2399 ema->match = match;
2400 /* add EM anchor to EM anchors list */
2401 list_add_tail(&ema->ema_list, &lport->ema_list);
2402 kref_get(&mp->kref);
2403 return ema;
2404}
2405EXPORT_SYMBOL(fc_exch_mgr_add);
2406
2407/**
2408 * fc_exch_mgr_destroy() - Destroy an exchange manager
2409 * @kref: The reference to the EM to be destroyed
2410 */
2411static void fc_exch_mgr_destroy(struct kref *kref)
2412{
2413 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
2414
2415 mempool_destroy(mp->ep_pool);
2416 free_percpu(mp->pool);
2417 kfree(mp);
2418}
2419
2420/**
2421 * fc_exch_mgr_del() - Delete an EM from a local port's list
2422 * @ema: The exchange manager anchor identifying the EM to be deleted
2423 */
2424void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
2425{
2426 /* remove EM anchor from EM anchors list */
2427 list_del(&ema->ema_list);
2428 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
2429 kfree(ema);
2430}
2431EXPORT_SYMBOL(fc_exch_mgr_del);
2432
2433/**
2434 * fc_exch_mgr_list_clone() - Share all exchange manager objects
2435 * @src: Source lport to clone exchange managers from
2436 * @dst: New lport that takes references to all the exchange managers
2437 */
2438int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)
2439{
2440 struct fc_exch_mgr_anchor *ema, *tmp;
2441
2442 list_for_each_entry(ema, &src->ema_list, ema_list) {
2443 if (!fc_exch_mgr_add(dst, ema->mp, ema->match))
2444 goto err;
2445 }
2446 return 0;
2447err:
2448 list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)
2449 fc_exch_mgr_del(ema);
2450 return -ENOMEM;
2451}
2452EXPORT_SYMBOL(fc_exch_mgr_list_clone);
2453
2454/**
2455 * fc_exch_mgr_alloc() - Allocate an exchange manager
2456 * @lport: The local port that the new EM will be associated with
2457 * @class: The default FC class for new exchanges
2458 * @min_xid: The minimum XID for exchanges from the new EM
2459 * @max_xid: The maximum XID for exchanges from the new EM
2460 * @match: The match routine for the new EM
2461 */
2462struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport,
2463 enum fc_class class,
2464 u16 min_xid, u16 max_xid,
2465 bool (*match)(struct fc_frame *))
2466{
2467 struct fc_exch_mgr *mp;
2468 u16 pool_exch_range;
2469 size_t pool_size;
2470 unsigned int cpu;
2471 struct fc_exch_pool *pool;
2472
2473 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
2474 (min_xid & fc_cpu_mask) != 0) {
2475 FC_LPORT_DBG(lport, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
2476 min_xid, max_xid);
2477 return NULL;
2478 }
2479
2480 /*
2481 * allocate memory for EM
2482 */
2483 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
2484 if (!mp)
2485 return NULL;
2486
2487 mp->class = class;
2488 mp->lport = lport;
2489 /* adjust em exch xid range for offload */
2490 mp->min_xid = min_xid;
2491
2492 /* reduce range so per cpu pool fits into PCPU_MIN_UNIT_SIZE pool */
2493 pool_exch_range = (PCPU_MIN_UNIT_SIZE - sizeof(*pool)) /
2494 sizeof(struct fc_exch *);
2495 if ((max_xid - min_xid + 1) / (fc_cpu_mask + 1) > pool_exch_range) {
2496 mp->max_xid = pool_exch_range * (fc_cpu_mask + 1) +
2497 min_xid - 1;
2498 } else {
2499 mp->max_xid = max_xid;
2500 pool_exch_range = (mp->max_xid - mp->min_xid + 1) /
2501 (fc_cpu_mask + 1);
2502 }
2503
2504 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
2505 if (!mp->ep_pool)
2506 goto free_mp;
2507
2508 /*
2509 * Setup per cpu exch pool with entire exchange id range equally
2510 * divided across all cpus. The exch pointers array memory is
2511 * allocated for exch range per pool.
2512 */
2513 mp->pool_max_index = pool_exch_range - 1;
2514
2515 /*
2516 * Allocate and initialize per cpu exch pool
2517 */
2518 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
2519 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
2520 if (!mp->pool)
2521 goto free_mempool;
2522 for_each_possible_cpu(cpu) {
2523 pool = per_cpu_ptr(mp->pool, cpu);
2524 pool->next_index = 0;
2525 pool->left = FC_XID_UNKNOWN;
2526 pool->right = FC_XID_UNKNOWN;
2527 spin_lock_init(&pool->lock);
2528 INIT_LIST_HEAD(&pool->ex_list);
2529 }
2530
2531 kref_init(&mp->kref);
2532 if (!fc_exch_mgr_add(lport, mp, match)) {
2533 free_percpu(mp->pool);
2534 goto free_mempool;
2535 }
2536
2537 /*
2538 * Above kref_init() sets mp->kref to 1 and then
2539 * call to fc_exch_mgr_add incremented mp->kref again,
2540 * so adjust that extra increment.
2541 */
2542 kref_put(&mp->kref, fc_exch_mgr_destroy);
2543 return mp;
2544
2545free_mempool:
2546 mempool_destroy(mp->ep_pool);
2547free_mp:
2548 kfree(mp);
2549 return NULL;
2550}
2551EXPORT_SYMBOL(fc_exch_mgr_alloc);
2552
2553/**
2554 * fc_exch_mgr_free() - Free all exchange managers on a local port
2555 * @lport: The local port whose EMs are to be freed
2556 */
2557void fc_exch_mgr_free(struct fc_lport *lport)
2558{
2559 struct fc_exch_mgr_anchor *ema, *next;
2560
2561 flush_workqueue(fc_exch_workqueue);
2562 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
2563 fc_exch_mgr_del(ema);
2564}
2565EXPORT_SYMBOL(fc_exch_mgr_free);
2566
2567/**
2568 * fc_find_ema() - Lookup and return appropriate Exchange Manager Anchor depending
2569 * upon 'xid'.
2570 * @f_ctl: f_ctl
2571 * @lport: The local port the frame was received on
2572 * @fh: The received frame header
2573 */
2574static struct fc_exch_mgr_anchor *fc_find_ema(u32 f_ctl,
2575 struct fc_lport *lport,
2576 struct fc_frame_header *fh)
2577{
2578 struct fc_exch_mgr_anchor *ema;
2579 u16 xid;
2580
2581 if (f_ctl & FC_FC_EX_CTX)
2582 xid = ntohs(fh->fh_ox_id);
2583 else {
2584 xid = ntohs(fh->fh_rx_id);
2585 if (xid == FC_XID_UNKNOWN)
2586 return list_entry(lport->ema_list.prev,
2587 typeof(*ema), ema_list);
2588 }
2589
2590 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2591 if ((xid >= ema->mp->min_xid) &&
2592 (xid <= ema->mp->max_xid))
2593 return ema;
2594 }
2595 return NULL;
2596}
2597/**
2598 * fc_exch_recv() - Handler for received frames
2599 * @lport: The local port the frame was received on
2600 * @fp: The received frame
2601 */
2602void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)
2603{
2604 struct fc_frame_header *fh = fc_frame_header_get(fp);
2605 struct fc_exch_mgr_anchor *ema;
2606 u32 f_ctl;
2607
2608 /* lport lock ? */
2609 if (!lport || lport->state == LPORT_ST_DISABLED) {
2610 FC_LIBFC_DBG("Receiving frames for an lport that "
2611 "has not been initialized correctly\n");
2612 fc_frame_free(fp);
2613 return;
2614 }
2615
2616 f_ctl = ntoh24(fh->fh_f_ctl);
2617 ema = fc_find_ema(f_ctl, lport, fh);
2618 if (!ema) {
2619 FC_LPORT_DBG(lport, "Unable to find Exchange Manager Anchor,"
2620 "fc_ctl <0x%x>, xid <0x%x>\n",
2621 f_ctl,
2622 (f_ctl & FC_FC_EX_CTX) ?
2623 ntohs(fh->fh_ox_id) :
2624 ntohs(fh->fh_rx_id));
2625 fc_frame_free(fp);
2626 return;
2627 }
2628
2629 /*
2630 * If frame is marked invalid, just drop it.
2631 */
2632 switch (fr_eof(fp)) {
2633 case FC_EOF_T:
2634 if (f_ctl & FC_FC_END_SEQ)
2635 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2636 fallthrough;
2637 case FC_EOF_N:
2638 if (fh->fh_type == FC_TYPE_BLS)
2639 fc_exch_recv_bls(ema->mp, fp);
2640 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2641 FC_FC_EX_CTX)
2642 fc_exch_recv_seq_resp(ema->mp, fp);
2643 else if (f_ctl & FC_FC_SEQ_CTX)
2644 fc_exch_recv_resp(ema->mp, fp);
2645 else /* no EX_CTX and no SEQ_CTX */
2646 fc_exch_recv_req(lport, ema->mp, fp);
2647 break;
2648 default:
2649 FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)",
2650 fr_eof(fp));
2651 fc_frame_free(fp);
2652 }
2653}
2654EXPORT_SYMBOL(fc_exch_recv);
2655
2656/**
2657 * fc_exch_init() - Initialize the exchange layer for a local port
2658 * @lport: The local port to initialize the exchange layer for
2659 */
2660int fc_exch_init(struct fc_lport *lport)
2661{
2662 if (!lport->tt.exch_mgr_reset)
2663 lport->tt.exch_mgr_reset = fc_exch_mgr_reset;
2664
2665 return 0;
2666}
2667EXPORT_SYMBOL(fc_exch_init);
2668
2669/**
2670 * fc_setup_exch_mgr() - Setup an exchange manager
2671 */
2672int fc_setup_exch_mgr(void)
2673{
2674 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2675 0, SLAB_HWCACHE_ALIGN, NULL);
2676 if (!fc_em_cachep)
2677 return -ENOMEM;
2678
2679 /*
2680 * Initialize fc_cpu_mask and fc_cpu_order. The
2681 * fc_cpu_mask is set for nr_cpu_ids rounded up
2682 * to order of 2's * power and order is stored
2683 * in fc_cpu_order as this is later required in
2684 * mapping between an exch id and exch array index
2685 * in per cpu exch pool.
2686 *
2687 * This round up is required to align fc_cpu_mask
2688 * to exchange id's lower bits such that all incoming
2689 * frames of an exchange gets delivered to the same
2690 * cpu on which exchange originated by simple bitwise
2691 * AND operation between fc_cpu_mask and exchange id.
2692 */
2693 fc_cpu_order = ilog2(roundup_pow_of_two(nr_cpu_ids));
2694 fc_cpu_mask = (1 << fc_cpu_order) - 1;
2695
2696 fc_exch_workqueue = create_singlethread_workqueue("fc_exch_workqueue");
2697 if (!fc_exch_workqueue)
2698 goto err;
2699 return 0;
2700err:
2701 kmem_cache_destroy(fc_em_cachep);
2702 return -ENOMEM;
2703}
2704
2705/**
2706 * fc_destroy_exch_mgr() - Destroy an exchange manager
2707 */
2708void fc_destroy_exch_mgr(void)
2709{
2710 destroy_workqueue(fc_exch_workqueue);
2711 kmem_cache_destroy(fc_em_cachep);
2712}