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1/*
2 * Copyright(c) 2007 Intel Corporation. All rights reserved.
3 * Copyright(c) 2008 Red Hat, Inc. All rights reserved.
4 * Copyright(c) 2008 Mike Christie
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Maintained at www.Open-FCoE.org
20 */
21
22/*
23 * Fibre Channel exchange and sequence handling.
24 */
25
26#include <linux/timer.h>
27#include <linux/slab.h>
28#include <linux/err.h>
29#include <linux/export.h>
30#include <linux/log2.h>
31
32#include <scsi/fc/fc_fc2.h>
33
34#include <scsi/libfc.h>
35#include <scsi/fc_encode.h>
36
37#include "fc_libfc.h"
38
39u16 fc_cpu_mask; /* cpu mask for possible cpus */
40EXPORT_SYMBOL(fc_cpu_mask);
41static u16 fc_cpu_order; /* 2's power to represent total possible cpus */
42static struct kmem_cache *fc_em_cachep; /* cache for exchanges */
43static struct workqueue_struct *fc_exch_workqueue;
44
45/*
46 * Structure and function definitions for managing Fibre Channel Exchanges
47 * and Sequences.
48 *
49 * The three primary structures used here are fc_exch_mgr, fc_exch, and fc_seq.
50 *
51 * fc_exch_mgr holds the exchange state for an N port
52 *
53 * fc_exch holds state for one exchange and links to its active sequence.
54 *
55 * fc_seq holds the state for an individual sequence.
56 */
57
58/**
59 * struct fc_exch_pool - Per cpu exchange pool
60 * @next_index: Next possible free exchange index
61 * @total_exches: Total allocated exchanges
62 * @lock: Exch pool lock
63 * @ex_list: List of exchanges
64 *
65 * This structure manages per cpu exchanges in array of exchange pointers.
66 * This array is allocated followed by struct fc_exch_pool memory for
67 * assigned range of exchanges to per cpu pool.
68 */
69struct fc_exch_pool {
70 spinlock_t lock;
71 struct list_head ex_list;
72 u16 next_index;
73 u16 total_exches;
74
75 /* two cache of free slot in exch array */
76 u16 left;
77 u16 right;
78} ____cacheline_aligned_in_smp;
79
80/**
81 * struct fc_exch_mgr - The Exchange Manager (EM).
82 * @class: Default class for new sequences
83 * @kref: Reference counter
84 * @min_xid: Minimum exchange ID
85 * @max_xid: Maximum exchange ID
86 * @ep_pool: Reserved exchange pointers
87 * @pool_max_index: Max exch array index in exch pool
88 * @pool: Per cpu exch pool
89 * @stats: Statistics structure
90 *
91 * This structure is the center for creating exchanges and sequences.
92 * It manages the allocation of exchange IDs.
93 */
94struct fc_exch_mgr {
95 struct fc_exch_pool __percpu *pool;
96 mempool_t *ep_pool;
97 struct fc_lport *lport;
98 enum fc_class class;
99 struct kref kref;
100 u16 min_xid;
101 u16 max_xid;
102 u16 pool_max_index;
103
104 struct {
105 atomic_t no_free_exch;
106 atomic_t no_free_exch_xid;
107 atomic_t xid_not_found;
108 atomic_t xid_busy;
109 atomic_t seq_not_found;
110 atomic_t non_bls_resp;
111 } stats;
112};
113
114/**
115 * struct fc_exch_mgr_anchor - primary structure for list of EMs
116 * @ema_list: Exchange Manager Anchor list
117 * @mp: Exchange Manager associated with this anchor
118 * @match: Routine to determine if this anchor's EM should be used
119 *
120 * When walking the list of anchors the match routine will be called
121 * for each anchor to determine if that EM should be used. The last
122 * anchor in the list will always match to handle any exchanges not
123 * handled by other EMs. The non-default EMs would be added to the
124 * anchor list by HW that provides offloads.
125 */
126struct fc_exch_mgr_anchor {
127 struct list_head ema_list;
128 struct fc_exch_mgr *mp;
129 bool (*match)(struct fc_frame *);
130};
131
132static void fc_exch_rrq(struct fc_exch *);
133static void fc_seq_ls_acc(struct fc_frame *);
134static void fc_seq_ls_rjt(struct fc_frame *, enum fc_els_rjt_reason,
135 enum fc_els_rjt_explan);
136static void fc_exch_els_rec(struct fc_frame *);
137static void fc_exch_els_rrq(struct fc_frame *);
138
139/*
140 * Internal implementation notes.
141 *
142 * The exchange manager is one by default in libfc but LLD may choose
143 * to have one per CPU. The sequence manager is one per exchange manager
144 * and currently never separated.
145 *
146 * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field
147 * assigned by the Sequence Initiator that shall be unique for a specific
148 * D_ID and S_ID pair while the Sequence is open." Note that it isn't
149 * qualified by exchange ID, which one might think it would be.
150 * In practice this limits the number of open sequences and exchanges to 256
151 * per session. For most targets we could treat this limit as per exchange.
152 *
153 * The exchange and its sequence are freed when the last sequence is received.
154 * It's possible for the remote port to leave an exchange open without
155 * sending any sequences.
156 *
157 * Notes on reference counts:
158 *
159 * Exchanges are reference counted and exchange gets freed when the reference
160 * count becomes zero.
161 *
162 * Timeouts:
163 * Sequences are timed out for E_D_TOV and R_A_TOV.
164 *
165 * Sequence event handling:
166 *
167 * The following events may occur on initiator sequences:
168 *
169 * Send.
170 * For now, the whole thing is sent.
171 * Receive ACK
172 * This applies only to class F.
173 * The sequence is marked complete.
174 * ULP completion.
175 * The upper layer calls fc_exch_done() when done
176 * with exchange and sequence tuple.
177 * RX-inferred completion.
178 * When we receive the next sequence on the same exchange, we can
179 * retire the previous sequence ID. (XXX not implemented).
180 * Timeout.
181 * R_A_TOV frees the sequence ID. If we're waiting for ACK,
182 * E_D_TOV causes abort and calls upper layer response handler
183 * with FC_EX_TIMEOUT error.
184 * Receive RJT
185 * XXX defer.
186 * Send ABTS
187 * On timeout.
188 *
189 * The following events may occur on recipient sequences:
190 *
191 * Receive
192 * Allocate sequence for first frame received.
193 * Hold during receive handler.
194 * Release when final frame received.
195 * Keep status of last N of these for the ELS RES command. XXX TBD.
196 * Receive ABTS
197 * Deallocate sequence
198 * Send RJT
199 * Deallocate
200 *
201 * For now, we neglect conditions where only part of a sequence was
202 * received or transmitted, or where out-of-order receipt is detected.
203 */
204
205/*
206 * Locking notes:
207 *
208 * The EM code run in a per-CPU worker thread.
209 *
210 * To protect against concurrency between a worker thread code and timers,
211 * sequence allocation and deallocation must be locked.
212 * - exchange refcnt can be done atomicly without locks.
213 * - sequence allocation must be locked by exch lock.
214 * - If the EM pool lock and ex_lock must be taken at the same time, then the
215 * EM pool lock must be taken before the ex_lock.
216 */
217
218/*
219 * opcode names for debugging.
220 */
221static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;
222
223/**
224 * fc_exch_name_lookup() - Lookup name by opcode
225 * @op: Opcode to be looked up
226 * @table: Opcode/name table
227 * @max_index: Index not to be exceeded
228 *
229 * This routine is used to determine a human-readable string identifying
230 * a R_CTL opcode.
231 */
232static inline const char *fc_exch_name_lookup(unsigned int op, char **table,
233 unsigned int max_index)
234{
235 const char *name = NULL;
236
237 if (op < max_index)
238 name = table[op];
239 if (!name)
240 name = "unknown";
241 return name;
242}
243
244/**
245 * fc_exch_rctl_name() - Wrapper routine for fc_exch_name_lookup()
246 * @op: The opcode to be looked up
247 */
248static const char *fc_exch_rctl_name(unsigned int op)
249{
250 return fc_exch_name_lookup(op, fc_exch_rctl_names,
251 ARRAY_SIZE(fc_exch_rctl_names));
252}
253
254/**
255 * fc_exch_hold() - Increment an exchange's reference count
256 * @ep: Echange to be held
257 */
258static inline void fc_exch_hold(struct fc_exch *ep)
259{
260 atomic_inc(&ep->ex_refcnt);
261}
262
263/**
264 * fc_exch_setup_hdr() - Initialize a FC header by initializing some fields
265 * and determine SOF and EOF.
266 * @ep: The exchange to that will use the header
267 * @fp: The frame whose header is to be modified
268 * @f_ctl: F_CTL bits that will be used for the frame header
269 *
270 * The fields initialized by this routine are: fh_ox_id, fh_rx_id,
271 * fh_seq_id, fh_seq_cnt and the SOF and EOF.
272 */
273static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,
274 u32 f_ctl)
275{
276 struct fc_frame_header *fh = fc_frame_header_get(fp);
277 u16 fill;
278
279 fr_sof(fp) = ep->class;
280 if (ep->seq.cnt)
281 fr_sof(fp) = fc_sof_normal(ep->class);
282
283 if (f_ctl & FC_FC_END_SEQ) {
284 fr_eof(fp) = FC_EOF_T;
285 if (fc_sof_needs_ack(ep->class))
286 fr_eof(fp) = FC_EOF_N;
287 /*
288 * From F_CTL.
289 * The number of fill bytes to make the length a 4-byte
290 * multiple is the low order 2-bits of the f_ctl.
291 * The fill itself will have been cleared by the frame
292 * allocation.
293 * After this, the length will be even, as expected by
294 * the transport.
295 */
296 fill = fr_len(fp) & 3;
297 if (fill) {
298 fill = 4 - fill;
299 /* TODO, this may be a problem with fragmented skb */
300 skb_put(fp_skb(fp), fill);
301 hton24(fh->fh_f_ctl, f_ctl | fill);
302 }
303 } else {
304 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
305 fr_eof(fp) = FC_EOF_N;
306 }
307
308 /* Initialize remaining fh fields from fc_fill_fc_hdr */
309 fh->fh_ox_id = htons(ep->oxid);
310 fh->fh_rx_id = htons(ep->rxid);
311 fh->fh_seq_id = ep->seq.id;
312 fh->fh_seq_cnt = htons(ep->seq.cnt);
313}
314
315/**
316 * fc_exch_release() - Decrement an exchange's reference count
317 * @ep: Exchange to be released
318 *
319 * If the reference count reaches zero and the exchange is complete,
320 * it is freed.
321 */
322static void fc_exch_release(struct fc_exch *ep)
323{
324 struct fc_exch_mgr *mp;
325
326 if (atomic_dec_and_test(&ep->ex_refcnt)) {
327 mp = ep->em;
328 if (ep->destructor)
329 ep->destructor(&ep->seq, ep->arg);
330 WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));
331 mempool_free(ep, mp->ep_pool);
332 }
333}
334
335/**
336 * fc_exch_timer_cancel() - cancel exch timer
337 * @ep: The exchange whose timer to be canceled
338 */
339static inline void fc_exch_timer_cancel(struct fc_exch *ep)
340{
341 if (cancel_delayed_work(&ep->timeout_work)) {
342 FC_EXCH_DBG(ep, "Exchange timer canceled\n");
343 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
344 }
345}
346
347/**
348 * fc_exch_timer_set_locked() - Start a timer for an exchange w/ the
349 * the exchange lock held
350 * @ep: The exchange whose timer will start
351 * @timer_msec: The timeout period
352 *
353 * Used for upper level protocols to time out the exchange.
354 * The timer is cancelled when it fires or when the exchange completes.
355 */
356static inline void fc_exch_timer_set_locked(struct fc_exch *ep,
357 unsigned int timer_msec)
358{
359 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
360 return;
361
362 FC_EXCH_DBG(ep, "Exchange timer armed : %d msecs\n", timer_msec);
363
364 fc_exch_hold(ep); /* hold for timer */
365 if (!queue_delayed_work(fc_exch_workqueue, &ep->timeout_work,
366 msecs_to_jiffies(timer_msec))) {
367 FC_EXCH_DBG(ep, "Exchange already queued\n");
368 fc_exch_release(ep);
369 }
370}
371
372/**
373 * fc_exch_timer_set() - Lock the exchange and set the timer
374 * @ep: The exchange whose timer will start
375 * @timer_msec: The timeout period
376 */
377static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec)
378{
379 spin_lock_bh(&ep->ex_lock);
380 fc_exch_timer_set_locked(ep, timer_msec);
381 spin_unlock_bh(&ep->ex_lock);
382}
383
384/**
385 * fc_exch_done_locked() - Complete an exchange with the exchange lock held
386 * @ep: The exchange that is complete
387 *
388 * Note: May sleep if invoked from outside a response handler.
389 */
390static int fc_exch_done_locked(struct fc_exch *ep)
391{
392 int rc = 1;
393
394 /*
395 * We must check for completion in case there are two threads
396 * tyring to complete this. But the rrq code will reuse the
397 * ep, and in that case we only clear the resp and set it as
398 * complete, so it can be reused by the timer to send the rrq.
399 */
400 if (ep->state & FC_EX_DONE)
401 return rc;
402 ep->esb_stat |= ESB_ST_COMPLETE;
403
404 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
405 ep->state |= FC_EX_DONE;
406 fc_exch_timer_cancel(ep);
407 rc = 0;
408 }
409 return rc;
410}
411
412static struct fc_exch fc_quarantine_exch;
413
414/**
415 * fc_exch_ptr_get() - Return an exchange from an exchange pool
416 * @pool: Exchange Pool to get an exchange from
417 * @index: Index of the exchange within the pool
418 *
419 * Use the index to get an exchange from within an exchange pool. exches
420 * will point to an array of exchange pointers. The index will select
421 * the exchange within the array.
422 */
423static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,
424 u16 index)
425{
426 struct fc_exch **exches = (struct fc_exch **)(pool + 1);
427 return exches[index];
428}
429
430/**
431 * fc_exch_ptr_set() - Assign an exchange to a slot in an exchange pool
432 * @pool: The pool to assign the exchange to
433 * @index: The index in the pool where the exchange will be assigned
434 * @ep: The exchange to assign to the pool
435 */
436static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
437 struct fc_exch *ep)
438{
439 ((struct fc_exch **)(pool + 1))[index] = ep;
440}
441
442/**
443 * fc_exch_delete() - Delete an exchange
444 * @ep: The exchange to be deleted
445 */
446static void fc_exch_delete(struct fc_exch *ep)
447{
448 struct fc_exch_pool *pool;
449 u16 index;
450
451 pool = ep->pool;
452 spin_lock_bh(&pool->lock);
453 WARN_ON(pool->total_exches <= 0);
454 pool->total_exches--;
455
456 /* update cache of free slot */
457 index = (ep->xid - ep->em->min_xid) >> fc_cpu_order;
458 if (!(ep->state & FC_EX_QUARANTINE)) {
459 if (pool->left == FC_XID_UNKNOWN)
460 pool->left = index;
461 else if (pool->right == FC_XID_UNKNOWN)
462 pool->right = index;
463 else
464 pool->next_index = index;
465 fc_exch_ptr_set(pool, index, NULL);
466 } else {
467 fc_exch_ptr_set(pool, index, &fc_quarantine_exch);
468 }
469 list_del(&ep->ex_list);
470 spin_unlock_bh(&pool->lock);
471 fc_exch_release(ep); /* drop hold for exch in mp */
472}
473
474static int fc_seq_send_locked(struct fc_lport *lport, struct fc_seq *sp,
475 struct fc_frame *fp)
476{
477 struct fc_exch *ep;
478 struct fc_frame_header *fh = fc_frame_header_get(fp);
479 int error = -ENXIO;
480 u32 f_ctl;
481 u8 fh_type = fh->fh_type;
482
483 ep = fc_seq_exch(sp);
484
485 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL)) {
486 fc_frame_free(fp);
487 goto out;
488 }
489
490 WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT));
491
492 f_ctl = ntoh24(fh->fh_f_ctl);
493 fc_exch_setup_hdr(ep, fp, f_ctl);
494 fr_encaps(fp) = ep->encaps;
495
496 /*
497 * update sequence count if this frame is carrying
498 * multiple FC frames when sequence offload is enabled
499 * by LLD.
500 */
501 if (fr_max_payload(fp))
502 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),
503 fr_max_payload(fp));
504 else
505 sp->cnt++;
506
507 /*
508 * Send the frame.
509 */
510 error = lport->tt.frame_send(lport, fp);
511
512 if (fh_type == FC_TYPE_BLS)
513 goto out;
514
515 /*
516 * Update the exchange and sequence flags,
517 * assuming all frames for the sequence have been sent.
518 * We can only be called to send once for each sequence.
519 */
520 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
521 if (f_ctl & FC_FC_SEQ_INIT)
522 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
523out:
524 return error;
525}
526
527/**
528 * fc_seq_send() - Send a frame using existing sequence/exchange pair
529 * @lport: The local port that the exchange will be sent on
530 * @sp: The sequence to be sent
531 * @fp: The frame to be sent on the exchange
532 *
533 * Note: The frame will be freed either by a direct call to fc_frame_free(fp)
534 * or indirectly by calling libfc_function_template.frame_send().
535 */
536int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp, struct fc_frame *fp)
537{
538 struct fc_exch *ep;
539 int error;
540 ep = fc_seq_exch(sp);
541 spin_lock_bh(&ep->ex_lock);
542 error = fc_seq_send_locked(lport, sp, fp);
543 spin_unlock_bh(&ep->ex_lock);
544 return error;
545}
546EXPORT_SYMBOL(fc_seq_send);
547
548/**
549 * fc_seq_alloc() - Allocate a sequence for a given exchange
550 * @ep: The exchange to allocate a new sequence for
551 * @seq_id: The sequence ID to be used
552 *
553 * We don't support multiple originated sequences on the same exchange.
554 * By implication, any previously originated sequence on this exchange
555 * is complete, and we reallocate the same sequence.
556 */
557static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
558{
559 struct fc_seq *sp;
560
561 sp = &ep->seq;
562 sp->ssb_stat = 0;
563 sp->cnt = 0;
564 sp->id = seq_id;
565 return sp;
566}
567
568/**
569 * fc_seq_start_next_locked() - Allocate a new sequence on the same
570 * exchange as the supplied sequence
571 * @sp: The sequence/exchange to get a new sequence for
572 */
573static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
574{
575 struct fc_exch *ep = fc_seq_exch(sp);
576
577 sp = fc_seq_alloc(ep, ep->seq_id++);
578 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
579 ep->f_ctl, sp->id);
580 return sp;
581}
582
583/**
584 * fc_seq_start_next() - Lock the exchange and get a new sequence
585 * for a given sequence/exchange pair
586 * @sp: The sequence/exchange to get a new exchange for
587 */
588struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
589{
590 struct fc_exch *ep = fc_seq_exch(sp);
591
592 spin_lock_bh(&ep->ex_lock);
593 sp = fc_seq_start_next_locked(sp);
594 spin_unlock_bh(&ep->ex_lock);
595
596 return sp;
597}
598EXPORT_SYMBOL(fc_seq_start_next);
599
600/*
601 * Set the response handler for the exchange associated with a sequence.
602 *
603 * Note: May sleep if invoked from outside a response handler.
604 */
605void fc_seq_set_resp(struct fc_seq *sp,
606 void (*resp)(struct fc_seq *, struct fc_frame *, void *),
607 void *arg)
608{
609 struct fc_exch *ep = fc_seq_exch(sp);
610 DEFINE_WAIT(wait);
611
612 spin_lock_bh(&ep->ex_lock);
613 while (ep->resp_active && ep->resp_task != current) {
614 prepare_to_wait(&ep->resp_wq, &wait, TASK_UNINTERRUPTIBLE);
615 spin_unlock_bh(&ep->ex_lock);
616
617 schedule();
618
619 spin_lock_bh(&ep->ex_lock);
620 }
621 finish_wait(&ep->resp_wq, &wait);
622 ep->resp = resp;
623 ep->arg = arg;
624 spin_unlock_bh(&ep->ex_lock);
625}
626EXPORT_SYMBOL(fc_seq_set_resp);
627
628/**
629 * fc_exch_abort_locked() - Abort an exchange
630 * @ep: The exchange to be aborted
631 * @timer_msec: The period of time to wait before aborting
632 *
633 * Abort an exchange and sequence. Generally called because of a
634 * exchange timeout or an abort from the upper layer.
635 *
636 * A timer_msec can be specified for abort timeout, if non-zero
637 * timer_msec value is specified then exchange resp handler
638 * will be called with timeout error if no response to abort.
639 *
640 * Locking notes: Called with exch lock held
641 *
642 * Return value: 0 on success else error code
643 */
644static int fc_exch_abort_locked(struct fc_exch *ep,
645 unsigned int timer_msec)
646{
647 struct fc_seq *sp;
648 struct fc_frame *fp;
649 int error;
650
651 FC_EXCH_DBG(ep, "exch: abort, time %d msecs\n", timer_msec);
652 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
653 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
654 FC_EXCH_DBG(ep, "exch: already completed esb %x state %x\n",
655 ep->esb_stat, ep->state);
656 return -ENXIO;
657 }
658
659 /*
660 * Send the abort on a new sequence if possible.
661 */
662 sp = fc_seq_start_next_locked(&ep->seq);
663 if (!sp)
664 return -ENOMEM;
665
666 if (timer_msec)
667 fc_exch_timer_set_locked(ep, timer_msec);
668
669 if (ep->sid) {
670 /*
671 * Send an abort for the sequence that timed out.
672 */
673 fp = fc_frame_alloc(ep->lp, 0);
674 if (fp) {
675 ep->esb_stat |= ESB_ST_SEQ_INIT;
676 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
677 FC_TYPE_BLS, FC_FC_END_SEQ |
678 FC_FC_SEQ_INIT, 0);
679 error = fc_seq_send_locked(ep->lp, sp, fp);
680 } else {
681 error = -ENOBUFS;
682 }
683 } else {
684 /*
685 * If not logged into the fabric, don't send ABTS but leave
686 * sequence active until next timeout.
687 */
688 error = 0;
689 }
690 ep->esb_stat |= ESB_ST_ABNORMAL;
691 return error;
692}
693
694/**
695 * fc_seq_exch_abort() - Abort an exchange and sequence
696 * @req_sp: The sequence to be aborted
697 * @timer_msec: The period of time to wait before aborting
698 *
699 * Generally called because of a timeout or an abort from the upper layer.
700 *
701 * Return value: 0 on success else error code
702 */
703int fc_seq_exch_abort(const struct fc_seq *req_sp, unsigned int timer_msec)
704{
705 struct fc_exch *ep;
706 int error;
707
708 ep = fc_seq_exch(req_sp);
709 spin_lock_bh(&ep->ex_lock);
710 error = fc_exch_abort_locked(ep, timer_msec);
711 spin_unlock_bh(&ep->ex_lock);
712 return error;
713}
714
715/**
716 * fc_invoke_resp() - invoke ep->resp()
717 *
718 * Notes:
719 * It is assumed that after initialization finished (this means the
720 * first unlock of ex_lock after fc_exch_alloc()) ep->resp and ep->arg are
721 * modified only via fc_seq_set_resp(). This guarantees that none of these
722 * two variables changes if ep->resp_active > 0.
723 *
724 * If an fc_seq_set_resp() call is busy modifying ep->resp and ep->arg when
725 * this function is invoked, the first spin_lock_bh() call in this function
726 * will wait until fc_seq_set_resp() has finished modifying these variables.
727 *
728 * Since fc_exch_done() invokes fc_seq_set_resp() it is guaranteed that that
729 * ep->resp() won't be invoked after fc_exch_done() has returned.
730 *
731 * The response handler itself may invoke fc_exch_done(), which will clear the
732 * ep->resp pointer.
733 *
734 * Return value:
735 * Returns true if and only if ep->resp has been invoked.
736 */
737static bool fc_invoke_resp(struct fc_exch *ep, struct fc_seq *sp,
738 struct fc_frame *fp)
739{
740 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
741 void *arg;
742 bool res = false;
743
744 spin_lock_bh(&ep->ex_lock);
745 ep->resp_active++;
746 if (ep->resp_task != current)
747 ep->resp_task = !ep->resp_task ? current : NULL;
748 resp = ep->resp;
749 arg = ep->arg;
750 spin_unlock_bh(&ep->ex_lock);
751
752 if (resp) {
753 resp(sp, fp, arg);
754 res = true;
755 }
756
757 spin_lock_bh(&ep->ex_lock);
758 if (--ep->resp_active == 0)
759 ep->resp_task = NULL;
760 spin_unlock_bh(&ep->ex_lock);
761
762 if (ep->resp_active == 0)
763 wake_up(&ep->resp_wq);
764
765 return res;
766}
767
768/**
769 * fc_exch_timeout() - Handle exchange timer expiration
770 * @work: The work_struct identifying the exchange that timed out
771 */
772static void fc_exch_timeout(struct work_struct *work)
773{
774 struct fc_exch *ep = container_of(work, struct fc_exch,
775 timeout_work.work);
776 struct fc_seq *sp = &ep->seq;
777 u32 e_stat;
778 int rc = 1;
779
780 FC_EXCH_DBG(ep, "Exchange timed out state %x\n", ep->state);
781
782 spin_lock_bh(&ep->ex_lock);
783 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
784 goto unlock;
785
786 e_stat = ep->esb_stat;
787 if (e_stat & ESB_ST_COMPLETE) {
788 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
789 spin_unlock_bh(&ep->ex_lock);
790 if (e_stat & ESB_ST_REC_QUAL)
791 fc_exch_rrq(ep);
792 goto done;
793 } else {
794 if (e_stat & ESB_ST_ABNORMAL)
795 rc = fc_exch_done_locked(ep);
796 spin_unlock_bh(&ep->ex_lock);
797 if (!rc)
798 fc_exch_delete(ep);
799 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_TIMEOUT));
800 fc_seq_set_resp(sp, NULL, ep->arg);
801 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
802 goto done;
803 }
804unlock:
805 spin_unlock_bh(&ep->ex_lock);
806done:
807 /*
808 * This release matches the hold taken when the timer was set.
809 */
810 fc_exch_release(ep);
811}
812
813/**
814 * fc_exch_em_alloc() - Allocate an exchange from a specified EM.
815 * @lport: The local port that the exchange is for
816 * @mp: The exchange manager that will allocate the exchange
817 *
818 * Returns pointer to allocated fc_exch with exch lock held.
819 */
820static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
821 struct fc_exch_mgr *mp)
822{
823 struct fc_exch *ep;
824 unsigned int cpu;
825 u16 index;
826 struct fc_exch_pool *pool;
827
828 /* allocate memory for exchange */
829 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);
830 if (!ep) {
831 atomic_inc(&mp->stats.no_free_exch);
832 goto out;
833 }
834 memset(ep, 0, sizeof(*ep));
835
836 cpu = get_cpu();
837 pool = per_cpu_ptr(mp->pool, cpu);
838 spin_lock_bh(&pool->lock);
839 put_cpu();
840
841 /* peek cache of free slot */
842 if (pool->left != FC_XID_UNKNOWN) {
843 if (!WARN_ON(fc_exch_ptr_get(pool, pool->left))) {
844 index = pool->left;
845 pool->left = FC_XID_UNKNOWN;
846 goto hit;
847 }
848 }
849 if (pool->right != FC_XID_UNKNOWN) {
850 if (!WARN_ON(fc_exch_ptr_get(pool, pool->right))) {
851 index = pool->right;
852 pool->right = FC_XID_UNKNOWN;
853 goto hit;
854 }
855 }
856
857 index = pool->next_index;
858 /* allocate new exch from pool */
859 while (fc_exch_ptr_get(pool, index)) {
860 index = index == mp->pool_max_index ? 0 : index + 1;
861 if (index == pool->next_index)
862 goto err;
863 }
864 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
865hit:
866 fc_exch_hold(ep); /* hold for exch in mp */
867 spin_lock_init(&ep->ex_lock);
868 /*
869 * Hold exch lock for caller to prevent fc_exch_reset()
870 * from releasing exch while fc_exch_alloc() caller is
871 * still working on exch.
872 */
873 spin_lock_bh(&ep->ex_lock);
874
875 fc_exch_ptr_set(pool, index, ep);
876 list_add_tail(&ep->ex_list, &pool->ex_list);
877 fc_seq_alloc(ep, ep->seq_id++);
878 pool->total_exches++;
879 spin_unlock_bh(&pool->lock);
880
881 /*
882 * update exchange
883 */
884 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
885 ep->em = mp;
886 ep->pool = pool;
887 ep->lp = lport;
888 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
889 ep->rxid = FC_XID_UNKNOWN;
890 ep->class = mp->class;
891 ep->resp_active = 0;
892 init_waitqueue_head(&ep->resp_wq);
893 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
894out:
895 return ep;
896err:
897 spin_unlock_bh(&pool->lock);
898 atomic_inc(&mp->stats.no_free_exch_xid);
899 mempool_free(ep, mp->ep_pool);
900 return NULL;
901}
902
903/**
904 * fc_exch_alloc() - Allocate an exchange from an EM on a
905 * local port's list of EMs.
906 * @lport: The local port that will own the exchange
907 * @fp: The FC frame that the exchange will be for
908 *
909 * This function walks the list of exchange manager(EM)
910 * anchors to select an EM for a new exchange allocation. The
911 * EM is selected when a NULL match function pointer is encountered
912 * or when a call to a match function returns true.
913 */
914static struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
915 struct fc_frame *fp)
916{
917 struct fc_exch_mgr_anchor *ema;
918 struct fc_exch *ep;
919
920 list_for_each_entry(ema, &lport->ema_list, ema_list) {
921 if (!ema->match || ema->match(fp)) {
922 ep = fc_exch_em_alloc(lport, ema->mp);
923 if (ep)
924 return ep;
925 }
926 }
927 return NULL;
928}
929
930/**
931 * fc_exch_find() - Lookup and hold an exchange
932 * @mp: The exchange manager to lookup the exchange from
933 * @xid: The XID of the exchange to look up
934 */
935static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
936{
937 struct fc_lport *lport = mp->lport;
938 struct fc_exch_pool *pool;
939 struct fc_exch *ep = NULL;
940 u16 cpu = xid & fc_cpu_mask;
941
942 if (xid == FC_XID_UNKNOWN)
943 return NULL;
944
945 if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
946 pr_err("host%u: lport %6.6x: xid %d invalid CPU %d\n:",
947 lport->host->host_no, lport->port_id, xid, cpu);
948 return NULL;
949 }
950
951 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
952 pool = per_cpu_ptr(mp->pool, cpu);
953 spin_lock_bh(&pool->lock);
954 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
955 if (ep == &fc_quarantine_exch) {
956 FC_LPORT_DBG(lport, "xid %x quarantined\n", xid);
957 ep = NULL;
958 }
959 if (ep) {
960 WARN_ON(ep->xid != xid);
961 fc_exch_hold(ep);
962 }
963 spin_unlock_bh(&pool->lock);
964 }
965 return ep;
966}
967
968
969/**
970 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and
971 * the memory allocated for the related objects may be freed.
972 * @sp: The sequence that has completed
973 *
974 * Note: May sleep if invoked from outside a response handler.
975 */
976void fc_exch_done(struct fc_seq *sp)
977{
978 struct fc_exch *ep = fc_seq_exch(sp);
979 int rc;
980
981 spin_lock_bh(&ep->ex_lock);
982 rc = fc_exch_done_locked(ep);
983 spin_unlock_bh(&ep->ex_lock);
984
985 fc_seq_set_resp(sp, NULL, ep->arg);
986 if (!rc)
987 fc_exch_delete(ep);
988}
989EXPORT_SYMBOL(fc_exch_done);
990
991/**
992 * fc_exch_resp() - Allocate a new exchange for a response frame
993 * @lport: The local port that the exchange was for
994 * @mp: The exchange manager to allocate the exchange from
995 * @fp: The response frame
996 *
997 * Sets the responder ID in the frame header.
998 */
999static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
1000 struct fc_exch_mgr *mp,
1001 struct fc_frame *fp)
1002{
1003 struct fc_exch *ep;
1004 struct fc_frame_header *fh;
1005
1006 ep = fc_exch_alloc(lport, fp);
1007 if (ep) {
1008 ep->class = fc_frame_class(fp);
1009
1010 /*
1011 * Set EX_CTX indicating we're responding on this exchange.
1012 */
1013 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
1014 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
1015 fh = fc_frame_header_get(fp);
1016 ep->sid = ntoh24(fh->fh_d_id);
1017 ep->did = ntoh24(fh->fh_s_id);
1018 ep->oid = ep->did;
1019
1020 /*
1021 * Allocated exchange has placed the XID in the
1022 * originator field. Move it to the responder field,
1023 * and set the originator XID from the frame.
1024 */
1025 ep->rxid = ep->xid;
1026 ep->oxid = ntohs(fh->fh_ox_id);
1027 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
1028 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
1029 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
1030
1031 fc_exch_hold(ep); /* hold for caller */
1032 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
1033 }
1034 return ep;
1035}
1036
1037/**
1038 * fc_seq_lookup_recip() - Find a sequence where the other end
1039 * originated the sequence
1040 * @lport: The local port that the frame was sent to
1041 * @mp: The Exchange Manager to lookup the exchange from
1042 * @fp: The frame associated with the sequence we're looking for
1043 *
1044 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
1045 * on the ep that should be released by the caller.
1046 */
1047static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
1048 struct fc_exch_mgr *mp,
1049 struct fc_frame *fp)
1050{
1051 struct fc_frame_header *fh = fc_frame_header_get(fp);
1052 struct fc_exch *ep = NULL;
1053 struct fc_seq *sp = NULL;
1054 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
1055 u32 f_ctl;
1056 u16 xid;
1057
1058 f_ctl = ntoh24(fh->fh_f_ctl);
1059 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
1060
1061 /*
1062 * Lookup or create the exchange if we will be creating the sequence.
1063 */
1064 if (f_ctl & FC_FC_EX_CTX) {
1065 xid = ntohs(fh->fh_ox_id); /* we originated exch */
1066 ep = fc_exch_find(mp, xid);
1067 if (!ep) {
1068 atomic_inc(&mp->stats.xid_not_found);
1069 reject = FC_RJT_OX_ID;
1070 goto out;
1071 }
1072 if (ep->rxid == FC_XID_UNKNOWN)
1073 ep->rxid = ntohs(fh->fh_rx_id);
1074 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
1075 reject = FC_RJT_OX_ID;
1076 goto rel;
1077 }
1078 } else {
1079 xid = ntohs(fh->fh_rx_id); /* we are the responder */
1080
1081 /*
1082 * Special case for MDS issuing an ELS TEST with a
1083 * bad rxid of 0.
1084 * XXX take this out once we do the proper reject.
1085 */
1086 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
1087 fc_frame_payload_op(fp) == ELS_TEST) {
1088 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
1089 xid = FC_XID_UNKNOWN;
1090 }
1091
1092 /*
1093 * new sequence - find the exchange
1094 */
1095 ep = fc_exch_find(mp, xid);
1096 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
1097 if (ep) {
1098 atomic_inc(&mp->stats.xid_busy);
1099 reject = FC_RJT_RX_ID;
1100 goto rel;
1101 }
1102 ep = fc_exch_resp(lport, mp, fp);
1103 if (!ep) {
1104 reject = FC_RJT_EXCH_EST; /* XXX */
1105 goto out;
1106 }
1107 xid = ep->xid; /* get our XID */
1108 } else if (!ep) {
1109 atomic_inc(&mp->stats.xid_not_found);
1110 reject = FC_RJT_RX_ID; /* XID not found */
1111 goto out;
1112 }
1113 }
1114
1115 spin_lock_bh(&ep->ex_lock);
1116 /*
1117 * At this point, we have the exchange held.
1118 * Find or create the sequence.
1119 */
1120 if (fc_sof_is_init(fr_sof(fp))) {
1121 sp = &ep->seq;
1122 sp->ssb_stat |= SSB_ST_RESP;
1123 sp->id = fh->fh_seq_id;
1124 } else {
1125 sp = &ep->seq;
1126 if (sp->id != fh->fh_seq_id) {
1127 atomic_inc(&mp->stats.seq_not_found);
1128 if (f_ctl & FC_FC_END_SEQ) {
1129 /*
1130 * Update sequence_id based on incoming last
1131 * frame of sequence exchange. This is needed
1132 * for FC target where DDP has been used
1133 * on target where, stack is indicated only
1134 * about last frame's (payload _header) header.
1135 * Whereas "seq_id" which is part of
1136 * frame_header is allocated by initiator
1137 * which is totally different from "seq_id"
1138 * allocated when XFER_RDY was sent by target.
1139 * To avoid false -ve which results into not
1140 * sending RSP, hence write request on other
1141 * end never finishes.
1142 */
1143 sp->ssb_stat |= SSB_ST_RESP;
1144 sp->id = fh->fh_seq_id;
1145 } else {
1146 spin_unlock_bh(&ep->ex_lock);
1147
1148 /* sequence/exch should exist */
1149 reject = FC_RJT_SEQ_ID;
1150 goto rel;
1151 }
1152 }
1153 }
1154 WARN_ON(ep != fc_seq_exch(sp));
1155
1156 if (f_ctl & FC_FC_SEQ_INIT)
1157 ep->esb_stat |= ESB_ST_SEQ_INIT;
1158 spin_unlock_bh(&ep->ex_lock);
1159
1160 fr_seq(fp) = sp;
1161out:
1162 return reject;
1163rel:
1164 fc_exch_done(&ep->seq);
1165 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
1166 return reject;
1167}
1168
1169/**
1170 * fc_seq_lookup_orig() - Find a sequence where this end
1171 * originated the sequence
1172 * @mp: The Exchange Manager to lookup the exchange from
1173 * @fp: The frame associated with the sequence we're looking for
1174 *
1175 * Does not hold the sequence for the caller.
1176 */
1177static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
1178 struct fc_frame *fp)
1179{
1180 struct fc_frame_header *fh = fc_frame_header_get(fp);
1181 struct fc_exch *ep;
1182 struct fc_seq *sp = NULL;
1183 u32 f_ctl;
1184 u16 xid;
1185
1186 f_ctl = ntoh24(fh->fh_f_ctl);
1187 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
1188 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
1189 ep = fc_exch_find(mp, xid);
1190 if (!ep)
1191 return NULL;
1192 if (ep->seq.id == fh->fh_seq_id) {
1193 /*
1194 * Save the RX_ID if we didn't previously know it.
1195 */
1196 sp = &ep->seq;
1197 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
1198 ep->rxid == FC_XID_UNKNOWN) {
1199 ep->rxid = ntohs(fh->fh_rx_id);
1200 }
1201 }
1202 fc_exch_release(ep);
1203 return sp;
1204}
1205
1206/**
1207 * fc_exch_set_addr() - Set the source and destination IDs for an exchange
1208 * @ep: The exchange to set the addresses for
1209 * @orig_id: The originator's ID
1210 * @resp_id: The responder's ID
1211 *
1212 * Note this must be done before the first sequence of the exchange is sent.
1213 */
1214static void fc_exch_set_addr(struct fc_exch *ep,
1215 u32 orig_id, u32 resp_id)
1216{
1217 ep->oid = orig_id;
1218 if (ep->esb_stat & ESB_ST_RESP) {
1219 ep->sid = resp_id;
1220 ep->did = orig_id;
1221 } else {
1222 ep->sid = orig_id;
1223 ep->did = resp_id;
1224 }
1225}
1226
1227/**
1228 * fc_seq_els_rsp_send() - Send an ELS response using information from
1229 * the existing sequence/exchange.
1230 * @fp: The received frame
1231 * @els_cmd: The ELS command to be sent
1232 * @els_data: The ELS data to be sent
1233 *
1234 * The received frame is not freed.
1235 */
1236void fc_seq_els_rsp_send(struct fc_frame *fp, enum fc_els_cmd els_cmd,
1237 struct fc_seq_els_data *els_data)
1238{
1239 switch (els_cmd) {
1240 case ELS_LS_RJT:
1241 fc_seq_ls_rjt(fp, els_data->reason, els_data->explan);
1242 break;
1243 case ELS_LS_ACC:
1244 fc_seq_ls_acc(fp);
1245 break;
1246 case ELS_RRQ:
1247 fc_exch_els_rrq(fp);
1248 break;
1249 case ELS_REC:
1250 fc_exch_els_rec(fp);
1251 break;
1252 default:
1253 FC_LPORT_DBG(fr_dev(fp), "Invalid ELS CMD:%x\n", els_cmd);
1254 }
1255}
1256EXPORT_SYMBOL_GPL(fc_seq_els_rsp_send);
1257
1258/**
1259 * fc_seq_send_last() - Send a sequence that is the last in the exchange
1260 * @sp: The sequence that is to be sent
1261 * @fp: The frame that will be sent on the sequence
1262 * @rctl: The R_CTL information to be sent
1263 * @fh_type: The frame header type
1264 */
1265static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
1266 enum fc_rctl rctl, enum fc_fh_type fh_type)
1267{
1268 u32 f_ctl;
1269 struct fc_exch *ep = fc_seq_exch(sp);
1270
1271 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
1272 f_ctl |= ep->f_ctl;
1273 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
1274 fc_seq_send_locked(ep->lp, sp, fp);
1275}
1276
1277/**
1278 * fc_seq_send_ack() - Send an acknowledgement that we've received a frame
1279 * @sp: The sequence to send the ACK on
1280 * @rx_fp: The received frame that is being acknoledged
1281 *
1282 * Send ACK_1 (or equiv.) indicating we received something.
1283 */
1284static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
1285{
1286 struct fc_frame *fp;
1287 struct fc_frame_header *rx_fh;
1288 struct fc_frame_header *fh;
1289 struct fc_exch *ep = fc_seq_exch(sp);
1290 struct fc_lport *lport = ep->lp;
1291 unsigned int f_ctl;
1292
1293 /*
1294 * Don't send ACKs for class 3.
1295 */
1296 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
1297 fp = fc_frame_alloc(lport, 0);
1298 if (!fp) {
1299 FC_EXCH_DBG(ep, "Drop ACK request, out of memory\n");
1300 return;
1301 }
1302
1303 fh = fc_frame_header_get(fp);
1304 fh->fh_r_ctl = FC_RCTL_ACK_1;
1305 fh->fh_type = FC_TYPE_BLS;
1306
1307 /*
1308 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1309 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1310 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1311 * Last ACK uses bits 7-6 (continue sequence),
1312 * bits 5-4 are meaningful (what kind of ACK to use).
1313 */
1314 rx_fh = fc_frame_header_get(rx_fp);
1315 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1316 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1317 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
1318 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
1319 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1320 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1321 hton24(fh->fh_f_ctl, f_ctl);
1322
1323 fc_exch_setup_hdr(ep, fp, f_ctl);
1324 fh->fh_seq_id = rx_fh->fh_seq_id;
1325 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1326 fh->fh_parm_offset = htonl(1); /* ack single frame */
1327
1328 fr_sof(fp) = fr_sof(rx_fp);
1329 if (f_ctl & FC_FC_END_SEQ)
1330 fr_eof(fp) = FC_EOF_T;
1331 else
1332 fr_eof(fp) = FC_EOF_N;
1333
1334 lport->tt.frame_send(lport, fp);
1335 }
1336}
1337
1338/**
1339 * fc_exch_send_ba_rjt() - Send BLS Reject
1340 * @rx_fp: The frame being rejected
1341 * @reason: The reason the frame is being rejected
1342 * @explan: The explanation for the rejection
1343 *
1344 * This is for rejecting BA_ABTS only.
1345 */
1346static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
1347 enum fc_ba_rjt_reason reason,
1348 enum fc_ba_rjt_explan explan)
1349{
1350 struct fc_frame *fp;
1351 struct fc_frame_header *rx_fh;
1352 struct fc_frame_header *fh;
1353 struct fc_ba_rjt *rp;
1354 struct fc_seq *sp;
1355 struct fc_lport *lport;
1356 unsigned int f_ctl;
1357
1358 lport = fr_dev(rx_fp);
1359 sp = fr_seq(rx_fp);
1360 fp = fc_frame_alloc(lport, sizeof(*rp));
1361 if (!fp) {
1362 FC_EXCH_DBG(fc_seq_exch(sp),
1363 "Drop BA_RJT request, out of memory\n");
1364 return;
1365 }
1366 fh = fc_frame_header_get(fp);
1367 rx_fh = fc_frame_header_get(rx_fp);
1368
1369 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1370
1371 rp = fc_frame_payload_get(fp, sizeof(*rp));
1372 rp->br_reason = reason;
1373 rp->br_explan = explan;
1374
1375 /*
1376 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1377 */
1378 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1379 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1380 fh->fh_ox_id = rx_fh->fh_ox_id;
1381 fh->fh_rx_id = rx_fh->fh_rx_id;
1382 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1383 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1384 fh->fh_type = FC_TYPE_BLS;
1385
1386 /*
1387 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1388 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1389 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1390 * Last ACK uses bits 7-6 (continue sequence),
1391 * bits 5-4 are meaningful (what kind of ACK to use).
1392 * Always set LAST_SEQ, END_SEQ.
1393 */
1394 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1395 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1396 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1397 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1398 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1399 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1400 f_ctl &= ~FC_FC_FIRST_SEQ;
1401 hton24(fh->fh_f_ctl, f_ctl);
1402
1403 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1404 fr_eof(fp) = FC_EOF_T;
1405 if (fc_sof_needs_ack(fr_sof(fp)))
1406 fr_eof(fp) = FC_EOF_N;
1407
1408 lport->tt.frame_send(lport, fp);
1409}
1410
1411/**
1412 * fc_exch_recv_abts() - Handle an incoming ABTS
1413 * @ep: The exchange the abort was on
1414 * @rx_fp: The ABTS frame
1415 *
1416 * This would be for target mode usually, but could be due to lost
1417 * FCP transfer ready, confirm or RRQ. We always handle this as an
1418 * exchange abort, ignoring the parameter.
1419 */
1420static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1421{
1422 struct fc_frame *fp;
1423 struct fc_ba_acc *ap;
1424 struct fc_frame_header *fh;
1425 struct fc_seq *sp;
1426
1427 if (!ep)
1428 goto reject;
1429
1430 FC_EXCH_DBG(ep, "exch: ABTS received\n");
1431 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1432 if (!fp) {
1433 FC_EXCH_DBG(ep, "Drop ABTS request, out of memory\n");
1434 goto free;
1435 }
1436
1437 spin_lock_bh(&ep->ex_lock);
1438 if (ep->esb_stat & ESB_ST_COMPLETE) {
1439 spin_unlock_bh(&ep->ex_lock);
1440 FC_EXCH_DBG(ep, "exch: ABTS rejected, exchange complete\n");
1441 fc_frame_free(fp);
1442 goto reject;
1443 }
1444 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
1445 ep->esb_stat |= ESB_ST_REC_QUAL;
1446 fc_exch_hold(ep); /* hold for REC_QUAL */
1447 }
1448 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1449 fh = fc_frame_header_get(fp);
1450 ap = fc_frame_payload_get(fp, sizeof(*ap));
1451 memset(ap, 0, sizeof(*ap));
1452 sp = &ep->seq;
1453 ap->ba_high_seq_cnt = htons(0xffff);
1454 if (sp->ssb_stat & SSB_ST_RESP) {
1455 ap->ba_seq_id = sp->id;
1456 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1457 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1458 ap->ba_low_seq_cnt = htons(sp->cnt);
1459 }
1460 sp = fc_seq_start_next_locked(sp);
1461 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1462 ep->esb_stat |= ESB_ST_ABNORMAL;
1463 spin_unlock_bh(&ep->ex_lock);
1464
1465free:
1466 fc_frame_free(rx_fp);
1467 return;
1468
1469reject:
1470 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1471 goto free;
1472}
1473
1474/**
1475 * fc_seq_assign() - Assign exchange and sequence for incoming request
1476 * @lport: The local port that received the request
1477 * @fp: The request frame
1478 *
1479 * On success, the sequence pointer will be returned and also in fr_seq(@fp).
1480 * A reference will be held on the exchange/sequence for the caller, which
1481 * must call fc_seq_release().
1482 */
1483struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)
1484{
1485 struct fc_exch_mgr_anchor *ema;
1486
1487 WARN_ON(lport != fr_dev(fp));
1488 WARN_ON(fr_seq(fp));
1489 fr_seq(fp) = NULL;
1490
1491 list_for_each_entry(ema, &lport->ema_list, ema_list)
1492 if ((!ema->match || ema->match(fp)) &&
1493 fc_seq_lookup_recip(lport, ema->mp, fp) == FC_RJT_NONE)
1494 break;
1495 return fr_seq(fp);
1496}
1497EXPORT_SYMBOL(fc_seq_assign);
1498
1499/**
1500 * fc_seq_release() - Release the hold
1501 * @sp: The sequence.
1502 */
1503void fc_seq_release(struct fc_seq *sp)
1504{
1505 fc_exch_release(fc_seq_exch(sp));
1506}
1507EXPORT_SYMBOL(fc_seq_release);
1508
1509/**
1510 * fc_exch_recv_req() - Handler for an incoming request
1511 * @lport: The local port that received the request
1512 * @mp: The EM that the exchange is on
1513 * @fp: The request frame
1514 *
1515 * This is used when the other end is originating the exchange
1516 * and the sequence.
1517 */
1518static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp,
1519 struct fc_frame *fp)
1520{
1521 struct fc_frame_header *fh = fc_frame_header_get(fp);
1522 struct fc_seq *sp = NULL;
1523 struct fc_exch *ep = NULL;
1524 enum fc_pf_rjt_reason reject;
1525
1526 /* We can have the wrong fc_lport at this point with NPIV, which is a
1527 * problem now that we know a new exchange needs to be allocated
1528 */
1529 lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id));
1530 if (!lport) {
1531 fc_frame_free(fp);
1532 return;
1533 }
1534 fr_dev(fp) = lport;
1535
1536 BUG_ON(fr_seq(fp)); /* XXX remove later */
1537
1538 /*
1539 * If the RX_ID is 0xffff, don't allocate an exchange.
1540 * The upper-level protocol may request one later, if needed.
1541 */
1542 if (fh->fh_rx_id == htons(FC_XID_UNKNOWN))
1543 return fc_lport_recv(lport, fp);
1544
1545 reject = fc_seq_lookup_recip(lport, mp, fp);
1546 if (reject == FC_RJT_NONE) {
1547 sp = fr_seq(fp); /* sequence will be held */
1548 ep = fc_seq_exch(sp);
1549 fc_seq_send_ack(sp, fp);
1550 ep->encaps = fr_encaps(fp);
1551
1552 /*
1553 * Call the receive function.
1554 *
1555 * The receive function may allocate a new sequence
1556 * over the old one, so we shouldn't change the
1557 * sequence after this.
1558 *
1559 * The frame will be freed by the receive function.
1560 * If new exch resp handler is valid then call that
1561 * first.
1562 */
1563 if (!fc_invoke_resp(ep, sp, fp))
1564 fc_lport_recv(lport, fp);
1565 fc_exch_release(ep); /* release from lookup */
1566 } else {
1567 FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n",
1568 reject);
1569 fc_frame_free(fp);
1570 }
1571}
1572
1573/**
1574 * fc_exch_recv_seq_resp() - Handler for an incoming response where the other
1575 * end is the originator of the sequence that is a
1576 * response to our initial exchange
1577 * @mp: The EM that the exchange is on
1578 * @fp: The response frame
1579 */
1580static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1581{
1582 struct fc_frame_header *fh = fc_frame_header_get(fp);
1583 struct fc_seq *sp;
1584 struct fc_exch *ep;
1585 enum fc_sof sof;
1586 u32 f_ctl;
1587 int rc;
1588
1589 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1590 if (!ep) {
1591 atomic_inc(&mp->stats.xid_not_found);
1592 goto out;
1593 }
1594 if (ep->esb_stat & ESB_ST_COMPLETE) {
1595 atomic_inc(&mp->stats.xid_not_found);
1596 goto rel;
1597 }
1598 if (ep->rxid == FC_XID_UNKNOWN)
1599 ep->rxid = ntohs(fh->fh_rx_id);
1600 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1601 atomic_inc(&mp->stats.xid_not_found);
1602 goto rel;
1603 }
1604 if (ep->did != ntoh24(fh->fh_s_id) &&
1605 ep->did != FC_FID_FLOGI) {
1606 atomic_inc(&mp->stats.xid_not_found);
1607 goto rel;
1608 }
1609 sof = fr_sof(fp);
1610 sp = &ep->seq;
1611 if (fc_sof_is_init(sof)) {
1612 sp->ssb_stat |= SSB_ST_RESP;
1613 sp->id = fh->fh_seq_id;
1614 }
1615
1616 f_ctl = ntoh24(fh->fh_f_ctl);
1617 fr_seq(fp) = sp;
1618
1619 spin_lock_bh(&ep->ex_lock);
1620 if (f_ctl & FC_FC_SEQ_INIT)
1621 ep->esb_stat |= ESB_ST_SEQ_INIT;
1622 spin_unlock_bh(&ep->ex_lock);
1623
1624 if (fc_sof_needs_ack(sof))
1625 fc_seq_send_ack(sp, fp);
1626
1627 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1628 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1629 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1630 spin_lock_bh(&ep->ex_lock);
1631 rc = fc_exch_done_locked(ep);
1632 WARN_ON(fc_seq_exch(sp) != ep);
1633 spin_unlock_bh(&ep->ex_lock);
1634 if (!rc)
1635 fc_exch_delete(ep);
1636 }
1637
1638 /*
1639 * Call the receive function.
1640 * The sequence is held (has a refcnt) for us,
1641 * but not for the receive function.
1642 *
1643 * The receive function may allocate a new sequence
1644 * over the old one, so we shouldn't change the
1645 * sequence after this.
1646 *
1647 * The frame will be freed by the receive function.
1648 * If new exch resp handler is valid then call that
1649 * first.
1650 */
1651 if (!fc_invoke_resp(ep, sp, fp))
1652 fc_frame_free(fp);
1653
1654 fc_exch_release(ep);
1655 return;
1656rel:
1657 fc_exch_release(ep);
1658out:
1659 fc_frame_free(fp);
1660}
1661
1662/**
1663 * fc_exch_recv_resp() - Handler for a sequence where other end is
1664 * responding to our sequence
1665 * @mp: The EM that the exchange is on
1666 * @fp: The response frame
1667 */
1668static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1669{
1670 struct fc_seq *sp;
1671
1672 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1673
1674 if (!sp)
1675 atomic_inc(&mp->stats.xid_not_found);
1676 else
1677 atomic_inc(&mp->stats.non_bls_resp);
1678
1679 fc_frame_free(fp);
1680}
1681
1682/**
1683 * fc_exch_abts_resp() - Handler for a response to an ABT
1684 * @ep: The exchange that the frame is on
1685 * @fp: The response frame
1686 *
1687 * This response would be to an ABTS cancelling an exchange or sequence.
1688 * The response can be either BA_ACC or BA_RJT
1689 */
1690static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1691{
1692 struct fc_frame_header *fh;
1693 struct fc_ba_acc *ap;
1694 struct fc_seq *sp;
1695 u16 low;
1696 u16 high;
1697 int rc = 1, has_rec = 0;
1698
1699 fh = fc_frame_header_get(fp);
1700 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1701 fc_exch_rctl_name(fh->fh_r_ctl));
1702
1703 if (cancel_delayed_work_sync(&ep->timeout_work)) {
1704 FC_EXCH_DBG(ep, "Exchange timer canceled due to ABTS response\n");
1705 fc_exch_release(ep); /* release from pending timer hold */
1706 }
1707
1708 spin_lock_bh(&ep->ex_lock);
1709 switch (fh->fh_r_ctl) {
1710 case FC_RCTL_BA_ACC:
1711 ap = fc_frame_payload_get(fp, sizeof(*ap));
1712 if (!ap)
1713 break;
1714
1715 /*
1716 * Decide whether to establish a Recovery Qualifier.
1717 * We do this if there is a non-empty SEQ_CNT range and
1718 * SEQ_ID is the same as the one we aborted.
1719 */
1720 low = ntohs(ap->ba_low_seq_cnt);
1721 high = ntohs(ap->ba_high_seq_cnt);
1722 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1723 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1724 ap->ba_seq_id == ep->seq_id) && low != high) {
1725 ep->esb_stat |= ESB_ST_REC_QUAL;
1726 fc_exch_hold(ep); /* hold for recovery qualifier */
1727 has_rec = 1;
1728 }
1729 break;
1730 case FC_RCTL_BA_RJT:
1731 break;
1732 default:
1733 break;
1734 }
1735
1736 /* do we need to do some other checks here. Can we reuse more of
1737 * fc_exch_recv_seq_resp
1738 */
1739 sp = &ep->seq;
1740 /*
1741 * do we want to check END_SEQ as well as LAST_SEQ here?
1742 */
1743 if (ep->fh_type != FC_TYPE_FCP &&
1744 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1745 rc = fc_exch_done_locked(ep);
1746 spin_unlock_bh(&ep->ex_lock);
1747
1748 fc_exch_hold(ep);
1749 if (!rc)
1750 fc_exch_delete(ep);
1751 if (!fc_invoke_resp(ep, sp, fp))
1752 fc_frame_free(fp);
1753 if (has_rec)
1754 fc_exch_timer_set(ep, ep->r_a_tov);
1755 fc_exch_release(ep);
1756}
1757
1758/**
1759 * fc_exch_recv_bls() - Handler for a BLS sequence
1760 * @mp: The EM that the exchange is on
1761 * @fp: The request frame
1762 *
1763 * The BLS frame is always a sequence initiated by the remote side.
1764 * We may be either the originator or recipient of the exchange.
1765 */
1766static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1767{
1768 struct fc_frame_header *fh;
1769 struct fc_exch *ep;
1770 u32 f_ctl;
1771
1772 fh = fc_frame_header_get(fp);
1773 f_ctl = ntoh24(fh->fh_f_ctl);
1774 fr_seq(fp) = NULL;
1775
1776 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1777 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1778 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1779 spin_lock_bh(&ep->ex_lock);
1780 ep->esb_stat |= ESB_ST_SEQ_INIT;
1781 spin_unlock_bh(&ep->ex_lock);
1782 }
1783 if (f_ctl & FC_FC_SEQ_CTX) {
1784 /*
1785 * A response to a sequence we initiated.
1786 * This should only be ACKs for class 2 or F.
1787 */
1788 switch (fh->fh_r_ctl) {
1789 case FC_RCTL_ACK_1:
1790 case FC_RCTL_ACK_0:
1791 break;
1792 default:
1793 if (ep)
1794 FC_EXCH_DBG(ep, "BLS rctl %x - %s received\n",
1795 fh->fh_r_ctl,
1796 fc_exch_rctl_name(fh->fh_r_ctl));
1797 break;
1798 }
1799 fc_frame_free(fp);
1800 } else {
1801 switch (fh->fh_r_ctl) {
1802 case FC_RCTL_BA_RJT:
1803 case FC_RCTL_BA_ACC:
1804 if (ep)
1805 fc_exch_abts_resp(ep, fp);
1806 else
1807 fc_frame_free(fp);
1808 break;
1809 case FC_RCTL_BA_ABTS:
1810 if (ep)
1811 fc_exch_recv_abts(ep, fp);
1812 else
1813 fc_frame_free(fp);
1814 break;
1815 default: /* ignore junk */
1816 fc_frame_free(fp);
1817 break;
1818 }
1819 }
1820 if (ep)
1821 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1822}
1823
1824/**
1825 * fc_seq_ls_acc() - Accept sequence with LS_ACC
1826 * @rx_fp: The received frame, not freed here.
1827 *
1828 * If this fails due to allocation or transmit congestion, assume the
1829 * originator will repeat the sequence.
1830 */
1831static void fc_seq_ls_acc(struct fc_frame *rx_fp)
1832{
1833 struct fc_lport *lport;
1834 struct fc_els_ls_acc *acc;
1835 struct fc_frame *fp;
1836 struct fc_seq *sp;
1837
1838 lport = fr_dev(rx_fp);
1839 sp = fr_seq(rx_fp);
1840 fp = fc_frame_alloc(lport, sizeof(*acc));
1841 if (!fp) {
1842 FC_EXCH_DBG(fc_seq_exch(sp),
1843 "exch: drop LS_ACC, out of memory\n");
1844 return;
1845 }
1846 acc = fc_frame_payload_get(fp, sizeof(*acc));
1847 memset(acc, 0, sizeof(*acc));
1848 acc->la_cmd = ELS_LS_ACC;
1849 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1850 lport->tt.frame_send(lport, fp);
1851}
1852
1853/**
1854 * fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT
1855 * @rx_fp: The received frame, not freed here.
1856 * @reason: The reason the sequence is being rejected
1857 * @explan: The explanation for the rejection
1858 *
1859 * If this fails due to allocation or transmit congestion, assume the
1860 * originator will repeat the sequence.
1861 */
1862static void fc_seq_ls_rjt(struct fc_frame *rx_fp, enum fc_els_rjt_reason reason,
1863 enum fc_els_rjt_explan explan)
1864{
1865 struct fc_lport *lport;
1866 struct fc_els_ls_rjt *rjt;
1867 struct fc_frame *fp;
1868 struct fc_seq *sp;
1869
1870 lport = fr_dev(rx_fp);
1871 sp = fr_seq(rx_fp);
1872 fp = fc_frame_alloc(lport, sizeof(*rjt));
1873 if (!fp) {
1874 FC_EXCH_DBG(fc_seq_exch(sp),
1875 "exch: drop LS_ACC, out of memory\n");
1876 return;
1877 }
1878 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1879 memset(rjt, 0, sizeof(*rjt));
1880 rjt->er_cmd = ELS_LS_RJT;
1881 rjt->er_reason = reason;
1882 rjt->er_explan = explan;
1883 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1884 lport->tt.frame_send(lport, fp);
1885}
1886
1887/**
1888 * fc_exch_reset() - Reset an exchange
1889 * @ep: The exchange to be reset
1890 *
1891 * Note: May sleep if invoked from outside a response handler.
1892 */
1893static void fc_exch_reset(struct fc_exch *ep)
1894{
1895 struct fc_seq *sp;
1896 int rc = 1;
1897
1898 spin_lock_bh(&ep->ex_lock);
1899 ep->state |= FC_EX_RST_CLEANUP;
1900 fc_exch_timer_cancel(ep);
1901 if (ep->esb_stat & ESB_ST_REC_QUAL)
1902 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1903 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1904 sp = &ep->seq;
1905 rc = fc_exch_done_locked(ep);
1906 spin_unlock_bh(&ep->ex_lock);
1907
1908 fc_exch_hold(ep);
1909
1910 if (!rc)
1911 fc_exch_delete(ep);
1912
1913 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_CLOSED));
1914 fc_seq_set_resp(sp, NULL, ep->arg);
1915 fc_exch_release(ep);
1916}
1917
1918/**
1919 * fc_exch_pool_reset() - Reset a per cpu exchange pool
1920 * @lport: The local port that the exchange pool is on
1921 * @pool: The exchange pool to be reset
1922 * @sid: The source ID
1923 * @did: The destination ID
1924 *
1925 * Resets a per cpu exches pool, releasing all of its sequences
1926 * and exchanges. If sid is non-zero then reset only exchanges
1927 * we sourced from the local port's FID. If did is non-zero then
1928 * only reset exchanges destined for the local port's FID.
1929 */
1930static void fc_exch_pool_reset(struct fc_lport *lport,
1931 struct fc_exch_pool *pool,
1932 u32 sid, u32 did)
1933{
1934 struct fc_exch *ep;
1935 struct fc_exch *next;
1936
1937 spin_lock_bh(&pool->lock);
1938restart:
1939 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1940 if ((lport == ep->lp) &&
1941 (sid == 0 || sid == ep->sid) &&
1942 (did == 0 || did == ep->did)) {
1943 fc_exch_hold(ep);
1944 spin_unlock_bh(&pool->lock);
1945
1946 fc_exch_reset(ep);
1947
1948 fc_exch_release(ep);
1949 spin_lock_bh(&pool->lock);
1950
1951 /*
1952 * must restart loop incase while lock
1953 * was down multiple eps were released.
1954 */
1955 goto restart;
1956 }
1957 }
1958 pool->next_index = 0;
1959 pool->left = FC_XID_UNKNOWN;
1960 pool->right = FC_XID_UNKNOWN;
1961 spin_unlock_bh(&pool->lock);
1962}
1963
1964/**
1965 * fc_exch_mgr_reset() - Reset all EMs of a local port
1966 * @lport: The local port whose EMs are to be reset
1967 * @sid: The source ID
1968 * @did: The destination ID
1969 *
1970 * Reset all EMs associated with a given local port. Release all
1971 * sequences and exchanges. If sid is non-zero then reset only the
1972 * exchanges sent from the local port's FID. If did is non-zero then
1973 * reset only exchanges destined for the local port's FID.
1974 */
1975void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1976{
1977 struct fc_exch_mgr_anchor *ema;
1978 unsigned int cpu;
1979
1980 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1981 for_each_possible_cpu(cpu)
1982 fc_exch_pool_reset(lport,
1983 per_cpu_ptr(ema->mp->pool, cpu),
1984 sid, did);
1985 }
1986}
1987EXPORT_SYMBOL(fc_exch_mgr_reset);
1988
1989/**
1990 * fc_exch_lookup() - find an exchange
1991 * @lport: The local port
1992 * @xid: The exchange ID
1993 *
1994 * Returns exchange pointer with hold for caller, or NULL if not found.
1995 */
1996static struct fc_exch *fc_exch_lookup(struct fc_lport *lport, u32 xid)
1997{
1998 struct fc_exch_mgr_anchor *ema;
1999
2000 list_for_each_entry(ema, &lport->ema_list, ema_list)
2001 if (ema->mp->min_xid <= xid && xid <= ema->mp->max_xid)
2002 return fc_exch_find(ema->mp, xid);
2003 return NULL;
2004}
2005
2006/**
2007 * fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests
2008 * @rfp: The REC frame, not freed here.
2009 *
2010 * Note that the requesting port may be different than the S_ID in the request.
2011 */
2012static void fc_exch_els_rec(struct fc_frame *rfp)
2013{
2014 struct fc_lport *lport;
2015 struct fc_frame *fp;
2016 struct fc_exch *ep;
2017 struct fc_els_rec *rp;
2018 struct fc_els_rec_acc *acc;
2019 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
2020 enum fc_els_rjt_explan explan;
2021 u32 sid;
2022 u16 xid, rxid, oxid;
2023
2024 lport = fr_dev(rfp);
2025 rp = fc_frame_payload_get(rfp, sizeof(*rp));
2026 explan = ELS_EXPL_INV_LEN;
2027 if (!rp)
2028 goto reject;
2029 sid = ntoh24(rp->rec_s_id);
2030 rxid = ntohs(rp->rec_rx_id);
2031 oxid = ntohs(rp->rec_ox_id);
2032
2033 explan = ELS_EXPL_OXID_RXID;
2034 if (sid == fc_host_port_id(lport->host))
2035 xid = oxid;
2036 else
2037 xid = rxid;
2038 if (xid == FC_XID_UNKNOWN) {
2039 FC_LPORT_DBG(lport,
2040 "REC request from %x: invalid rxid %x oxid %x\n",
2041 sid, rxid, oxid);
2042 goto reject;
2043 }
2044 ep = fc_exch_lookup(lport, xid);
2045 if (!ep) {
2046 FC_LPORT_DBG(lport,
2047 "REC request from %x: rxid %x oxid %x not found\n",
2048 sid, rxid, oxid);
2049 goto reject;
2050 }
2051 FC_EXCH_DBG(ep, "REC request from %x: rxid %x oxid %x\n",
2052 sid, rxid, oxid);
2053 if (ep->oid != sid || oxid != ep->oxid)
2054 goto rel;
2055 if (rxid != FC_XID_UNKNOWN && rxid != ep->rxid)
2056 goto rel;
2057 fp = fc_frame_alloc(lport, sizeof(*acc));
2058 if (!fp) {
2059 FC_EXCH_DBG(ep, "Drop REC request, out of memory\n");
2060 goto out;
2061 }
2062
2063 acc = fc_frame_payload_get(fp, sizeof(*acc));
2064 memset(acc, 0, sizeof(*acc));
2065 acc->reca_cmd = ELS_LS_ACC;
2066 acc->reca_ox_id = rp->rec_ox_id;
2067 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
2068 acc->reca_rx_id = htons(ep->rxid);
2069 if (ep->sid == ep->oid)
2070 hton24(acc->reca_rfid, ep->did);
2071 else
2072 hton24(acc->reca_rfid, ep->sid);
2073 acc->reca_fc4value = htonl(ep->seq.rec_data);
2074 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
2075 ESB_ST_SEQ_INIT |
2076 ESB_ST_COMPLETE));
2077 fc_fill_reply_hdr(fp, rfp, FC_RCTL_ELS_REP, 0);
2078 lport->tt.frame_send(lport, fp);
2079out:
2080 fc_exch_release(ep);
2081 return;
2082
2083rel:
2084 fc_exch_release(ep);
2085reject:
2086 fc_seq_ls_rjt(rfp, reason, explan);
2087}
2088
2089/**
2090 * fc_exch_rrq_resp() - Handler for RRQ responses
2091 * @sp: The sequence that the RRQ is on
2092 * @fp: The RRQ frame
2093 * @arg: The exchange that the RRQ is on
2094 *
2095 * TODO: fix error handler.
2096 */
2097static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
2098{
2099 struct fc_exch *aborted_ep = arg;
2100 unsigned int op;
2101
2102 if (IS_ERR(fp)) {
2103 int err = PTR_ERR(fp);
2104
2105 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
2106 goto cleanup;
2107 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
2108 "frame error %d\n", err);
2109 return;
2110 }
2111
2112 op = fc_frame_payload_op(fp);
2113 fc_frame_free(fp);
2114
2115 switch (op) {
2116 case ELS_LS_RJT:
2117 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ\n");
2118 /* fall through */
2119 case ELS_LS_ACC:
2120 goto cleanup;
2121 default:
2122 FC_EXCH_DBG(aborted_ep, "unexpected response op %x for RRQ\n",
2123 op);
2124 return;
2125 }
2126
2127cleanup:
2128 fc_exch_done(&aborted_ep->seq);
2129 /* drop hold for rec qual */
2130 fc_exch_release(aborted_ep);
2131}
2132
2133
2134/**
2135 * fc_exch_seq_send() - Send a frame using a new exchange and sequence
2136 * @lport: The local port to send the frame on
2137 * @fp: The frame to be sent
2138 * @resp: The response handler for this request
2139 * @destructor: The destructor for the exchange
2140 * @arg: The argument to be passed to the response handler
2141 * @timer_msec: The timeout period for the exchange
2142 *
2143 * The exchange response handler is set in this routine to resp()
2144 * function pointer. It can be called in two scenarios: if a timeout
2145 * occurs or if a response frame is received for the exchange. The
2146 * fc_frame pointer in response handler will also indicate timeout
2147 * as error using IS_ERR related macros.
2148 *
2149 * The exchange destructor handler is also set in this routine.
2150 * The destructor handler is invoked by EM layer when exchange
2151 * is about to free, this can be used by caller to free its
2152 * resources along with exchange free.
2153 *
2154 * The arg is passed back to resp and destructor handler.
2155 *
2156 * The timeout value (in msec) for an exchange is set if non zero
2157 * timer_msec argument is specified. The timer is canceled when
2158 * it fires or when the exchange is done. The exchange timeout handler
2159 * is registered by EM layer.
2160 *
2161 * The frame pointer with some of the header's fields must be
2162 * filled before calling this routine, those fields are:
2163 *
2164 * - routing control
2165 * - FC port did
2166 * - FC port sid
2167 * - FC header type
2168 * - frame control
2169 * - parameter or relative offset
2170 */
2171struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
2172 struct fc_frame *fp,
2173 void (*resp)(struct fc_seq *,
2174 struct fc_frame *fp,
2175 void *arg),
2176 void (*destructor)(struct fc_seq *, void *),
2177 void *arg, u32 timer_msec)
2178{
2179 struct fc_exch *ep;
2180 struct fc_seq *sp = NULL;
2181 struct fc_frame_header *fh;
2182 struct fc_fcp_pkt *fsp = NULL;
2183 int rc = 1;
2184
2185 ep = fc_exch_alloc(lport, fp);
2186 if (!ep) {
2187 fc_frame_free(fp);
2188 return NULL;
2189 }
2190 ep->esb_stat |= ESB_ST_SEQ_INIT;
2191 fh = fc_frame_header_get(fp);
2192 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
2193 ep->resp = resp;
2194 ep->destructor = destructor;
2195 ep->arg = arg;
2196 ep->r_a_tov = lport->r_a_tov;
2197 ep->lp = lport;
2198 sp = &ep->seq;
2199
2200 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
2201 ep->f_ctl = ntoh24(fh->fh_f_ctl);
2202 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
2203 sp->cnt++;
2204
2205 if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD) {
2206 fsp = fr_fsp(fp);
2207 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
2208 }
2209
2210 if (unlikely(lport->tt.frame_send(lport, fp)))
2211 goto err;
2212
2213 if (timer_msec)
2214 fc_exch_timer_set_locked(ep, timer_msec);
2215 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
2216
2217 if (ep->f_ctl & FC_FC_SEQ_INIT)
2218 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
2219 spin_unlock_bh(&ep->ex_lock);
2220 return sp;
2221err:
2222 if (fsp)
2223 fc_fcp_ddp_done(fsp);
2224 rc = fc_exch_done_locked(ep);
2225 spin_unlock_bh(&ep->ex_lock);
2226 if (!rc)
2227 fc_exch_delete(ep);
2228 return NULL;
2229}
2230EXPORT_SYMBOL(fc_exch_seq_send);
2231
2232/**
2233 * fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command
2234 * @ep: The exchange to send the RRQ on
2235 *
2236 * This tells the remote port to stop blocking the use of
2237 * the exchange and the seq_cnt range.
2238 */
2239static void fc_exch_rrq(struct fc_exch *ep)
2240{
2241 struct fc_lport *lport;
2242 struct fc_els_rrq *rrq;
2243 struct fc_frame *fp;
2244 u32 did;
2245
2246 lport = ep->lp;
2247
2248 fp = fc_frame_alloc(lport, sizeof(*rrq));
2249 if (!fp)
2250 goto retry;
2251
2252 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
2253 memset(rrq, 0, sizeof(*rrq));
2254 rrq->rrq_cmd = ELS_RRQ;
2255 hton24(rrq->rrq_s_id, ep->sid);
2256 rrq->rrq_ox_id = htons(ep->oxid);
2257 rrq->rrq_rx_id = htons(ep->rxid);
2258
2259 did = ep->did;
2260 if (ep->esb_stat & ESB_ST_RESP)
2261 did = ep->sid;
2262
2263 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
2264 lport->port_id, FC_TYPE_ELS,
2265 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
2266
2267 if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep,
2268 lport->e_d_tov))
2269 return;
2270
2271retry:
2272 FC_EXCH_DBG(ep, "exch: RRQ send failed\n");
2273 spin_lock_bh(&ep->ex_lock);
2274 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
2275 spin_unlock_bh(&ep->ex_lock);
2276 /* drop hold for rec qual */
2277 fc_exch_release(ep);
2278 return;
2279 }
2280 ep->esb_stat |= ESB_ST_REC_QUAL;
2281 fc_exch_timer_set_locked(ep, ep->r_a_tov);
2282 spin_unlock_bh(&ep->ex_lock);
2283}
2284
2285/**
2286 * fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests
2287 * @fp: The RRQ frame, not freed here.
2288 */
2289static void fc_exch_els_rrq(struct fc_frame *fp)
2290{
2291 struct fc_lport *lport;
2292 struct fc_exch *ep = NULL; /* request or subject exchange */
2293 struct fc_els_rrq *rp;
2294 u32 sid;
2295 u16 xid;
2296 enum fc_els_rjt_explan explan;
2297
2298 lport = fr_dev(fp);
2299 rp = fc_frame_payload_get(fp, sizeof(*rp));
2300 explan = ELS_EXPL_INV_LEN;
2301 if (!rp)
2302 goto reject;
2303
2304 /*
2305 * lookup subject exchange.
2306 */
2307 sid = ntoh24(rp->rrq_s_id); /* subject source */
2308 xid = fc_host_port_id(lport->host) == sid ?
2309 ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
2310 ep = fc_exch_lookup(lport, xid);
2311 explan = ELS_EXPL_OXID_RXID;
2312 if (!ep)
2313 goto reject;
2314 spin_lock_bh(&ep->ex_lock);
2315 FC_EXCH_DBG(ep, "RRQ request from %x: xid %x rxid %x oxid %x\n",
2316 sid, xid, ntohs(rp->rrq_rx_id), ntohs(rp->rrq_ox_id));
2317 if (ep->oxid != ntohs(rp->rrq_ox_id))
2318 goto unlock_reject;
2319 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
2320 ep->rxid != FC_XID_UNKNOWN)
2321 goto unlock_reject;
2322 explan = ELS_EXPL_SID;
2323 if (ep->sid != sid)
2324 goto unlock_reject;
2325
2326 /*
2327 * Clear Recovery Qualifier state, and cancel timer if complete.
2328 */
2329 if (ep->esb_stat & ESB_ST_REC_QUAL) {
2330 ep->esb_stat &= ~ESB_ST_REC_QUAL;
2331 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
2332 }
2333 if (ep->esb_stat & ESB_ST_COMPLETE)
2334 fc_exch_timer_cancel(ep);
2335
2336 spin_unlock_bh(&ep->ex_lock);
2337
2338 /*
2339 * Send LS_ACC.
2340 */
2341 fc_seq_ls_acc(fp);
2342 goto out;
2343
2344unlock_reject:
2345 spin_unlock_bh(&ep->ex_lock);
2346reject:
2347 fc_seq_ls_rjt(fp, ELS_RJT_LOGIC, explan);
2348out:
2349 if (ep)
2350 fc_exch_release(ep); /* drop hold from fc_exch_find */
2351}
2352
2353/**
2354 * fc_exch_update_stats() - update exches stats to lport
2355 * @lport: The local port to update exchange manager stats
2356 */
2357void fc_exch_update_stats(struct fc_lport *lport)
2358{
2359 struct fc_host_statistics *st;
2360 struct fc_exch_mgr_anchor *ema;
2361 struct fc_exch_mgr *mp;
2362
2363 st = &lport->host_stats;
2364
2365 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2366 mp = ema->mp;
2367 st->fc_no_free_exch += atomic_read(&mp->stats.no_free_exch);
2368 st->fc_no_free_exch_xid +=
2369 atomic_read(&mp->stats.no_free_exch_xid);
2370 st->fc_xid_not_found += atomic_read(&mp->stats.xid_not_found);
2371 st->fc_xid_busy += atomic_read(&mp->stats.xid_busy);
2372 st->fc_seq_not_found += atomic_read(&mp->stats.seq_not_found);
2373 st->fc_non_bls_resp += atomic_read(&mp->stats.non_bls_resp);
2374 }
2375}
2376EXPORT_SYMBOL(fc_exch_update_stats);
2377
2378/**
2379 * fc_exch_mgr_add() - Add an exchange manager to a local port's list of EMs
2380 * @lport: The local port to add the exchange manager to
2381 * @mp: The exchange manager to be added to the local port
2382 * @match: The match routine that indicates when this EM should be used
2383 */
2384struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
2385 struct fc_exch_mgr *mp,
2386 bool (*match)(struct fc_frame *))
2387{
2388 struct fc_exch_mgr_anchor *ema;
2389
2390 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
2391 if (!ema)
2392 return ema;
2393
2394 ema->mp = mp;
2395 ema->match = match;
2396 /* add EM anchor to EM anchors list */
2397 list_add_tail(&ema->ema_list, &lport->ema_list);
2398 kref_get(&mp->kref);
2399 return ema;
2400}
2401EXPORT_SYMBOL(fc_exch_mgr_add);
2402
2403/**
2404 * fc_exch_mgr_destroy() - Destroy an exchange manager
2405 * @kref: The reference to the EM to be destroyed
2406 */
2407static void fc_exch_mgr_destroy(struct kref *kref)
2408{
2409 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
2410
2411 mempool_destroy(mp->ep_pool);
2412 free_percpu(mp->pool);
2413 kfree(mp);
2414}
2415
2416/**
2417 * fc_exch_mgr_del() - Delete an EM from a local port's list
2418 * @ema: The exchange manager anchor identifying the EM to be deleted
2419 */
2420void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
2421{
2422 /* remove EM anchor from EM anchors list */
2423 list_del(&ema->ema_list);
2424 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
2425 kfree(ema);
2426}
2427EXPORT_SYMBOL(fc_exch_mgr_del);
2428
2429/**
2430 * fc_exch_mgr_list_clone() - Share all exchange manager objects
2431 * @src: Source lport to clone exchange managers from
2432 * @dst: New lport that takes references to all the exchange managers
2433 */
2434int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)
2435{
2436 struct fc_exch_mgr_anchor *ema, *tmp;
2437
2438 list_for_each_entry(ema, &src->ema_list, ema_list) {
2439 if (!fc_exch_mgr_add(dst, ema->mp, ema->match))
2440 goto err;
2441 }
2442 return 0;
2443err:
2444 list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)
2445 fc_exch_mgr_del(ema);
2446 return -ENOMEM;
2447}
2448EXPORT_SYMBOL(fc_exch_mgr_list_clone);
2449
2450/**
2451 * fc_exch_mgr_alloc() - Allocate an exchange manager
2452 * @lport: The local port that the new EM will be associated with
2453 * @class: The default FC class for new exchanges
2454 * @min_xid: The minimum XID for exchanges from the new EM
2455 * @max_xid: The maximum XID for exchanges from the new EM
2456 * @match: The match routine for the new EM
2457 */
2458struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport,
2459 enum fc_class class,
2460 u16 min_xid, u16 max_xid,
2461 bool (*match)(struct fc_frame *))
2462{
2463 struct fc_exch_mgr *mp;
2464 u16 pool_exch_range;
2465 size_t pool_size;
2466 unsigned int cpu;
2467 struct fc_exch_pool *pool;
2468
2469 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
2470 (min_xid & fc_cpu_mask) != 0) {
2471 FC_LPORT_DBG(lport, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
2472 min_xid, max_xid);
2473 return NULL;
2474 }
2475
2476 /*
2477 * allocate memory for EM
2478 */
2479 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
2480 if (!mp)
2481 return NULL;
2482
2483 mp->class = class;
2484 mp->lport = lport;
2485 /* adjust em exch xid range for offload */
2486 mp->min_xid = min_xid;
2487
2488 /* reduce range so per cpu pool fits into PCPU_MIN_UNIT_SIZE pool */
2489 pool_exch_range = (PCPU_MIN_UNIT_SIZE - sizeof(*pool)) /
2490 sizeof(struct fc_exch *);
2491 if ((max_xid - min_xid + 1) / (fc_cpu_mask + 1) > pool_exch_range) {
2492 mp->max_xid = pool_exch_range * (fc_cpu_mask + 1) +
2493 min_xid - 1;
2494 } else {
2495 mp->max_xid = max_xid;
2496 pool_exch_range = (mp->max_xid - mp->min_xid + 1) /
2497 (fc_cpu_mask + 1);
2498 }
2499
2500 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
2501 if (!mp->ep_pool)
2502 goto free_mp;
2503
2504 /*
2505 * Setup per cpu exch pool with entire exchange id range equally
2506 * divided across all cpus. The exch pointers array memory is
2507 * allocated for exch range per pool.
2508 */
2509 mp->pool_max_index = pool_exch_range - 1;
2510
2511 /*
2512 * Allocate and initialize per cpu exch pool
2513 */
2514 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
2515 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
2516 if (!mp->pool)
2517 goto free_mempool;
2518 for_each_possible_cpu(cpu) {
2519 pool = per_cpu_ptr(mp->pool, cpu);
2520 pool->next_index = 0;
2521 pool->left = FC_XID_UNKNOWN;
2522 pool->right = FC_XID_UNKNOWN;
2523 spin_lock_init(&pool->lock);
2524 INIT_LIST_HEAD(&pool->ex_list);
2525 }
2526
2527 kref_init(&mp->kref);
2528 if (!fc_exch_mgr_add(lport, mp, match)) {
2529 free_percpu(mp->pool);
2530 goto free_mempool;
2531 }
2532
2533 /*
2534 * Above kref_init() sets mp->kref to 1 and then
2535 * call to fc_exch_mgr_add incremented mp->kref again,
2536 * so adjust that extra increment.
2537 */
2538 kref_put(&mp->kref, fc_exch_mgr_destroy);
2539 return mp;
2540
2541free_mempool:
2542 mempool_destroy(mp->ep_pool);
2543free_mp:
2544 kfree(mp);
2545 return NULL;
2546}
2547EXPORT_SYMBOL(fc_exch_mgr_alloc);
2548
2549/**
2550 * fc_exch_mgr_free() - Free all exchange managers on a local port
2551 * @lport: The local port whose EMs are to be freed
2552 */
2553void fc_exch_mgr_free(struct fc_lport *lport)
2554{
2555 struct fc_exch_mgr_anchor *ema, *next;
2556
2557 flush_workqueue(fc_exch_workqueue);
2558 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
2559 fc_exch_mgr_del(ema);
2560}
2561EXPORT_SYMBOL(fc_exch_mgr_free);
2562
2563/**
2564 * fc_find_ema() - Lookup and return appropriate Exchange Manager Anchor depending
2565 * upon 'xid'.
2566 * @f_ctl: f_ctl
2567 * @lport: The local port the frame was received on
2568 * @fh: The received frame header
2569 */
2570static struct fc_exch_mgr_anchor *fc_find_ema(u32 f_ctl,
2571 struct fc_lport *lport,
2572 struct fc_frame_header *fh)
2573{
2574 struct fc_exch_mgr_anchor *ema;
2575 u16 xid;
2576
2577 if (f_ctl & FC_FC_EX_CTX)
2578 xid = ntohs(fh->fh_ox_id);
2579 else {
2580 xid = ntohs(fh->fh_rx_id);
2581 if (xid == FC_XID_UNKNOWN)
2582 return list_entry(lport->ema_list.prev,
2583 typeof(*ema), ema_list);
2584 }
2585
2586 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2587 if ((xid >= ema->mp->min_xid) &&
2588 (xid <= ema->mp->max_xid))
2589 return ema;
2590 }
2591 return NULL;
2592}
2593/**
2594 * fc_exch_recv() - Handler for received frames
2595 * @lport: The local port the frame was received on
2596 * @fp: The received frame
2597 */
2598void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)
2599{
2600 struct fc_frame_header *fh = fc_frame_header_get(fp);
2601 struct fc_exch_mgr_anchor *ema;
2602 u32 f_ctl;
2603
2604 /* lport lock ? */
2605 if (!lport || lport->state == LPORT_ST_DISABLED) {
2606 FC_LPORT_DBG(lport, "Receiving frames for an lport that "
2607 "has not been initialized correctly\n");
2608 fc_frame_free(fp);
2609 return;
2610 }
2611
2612 f_ctl = ntoh24(fh->fh_f_ctl);
2613 ema = fc_find_ema(f_ctl, lport, fh);
2614 if (!ema) {
2615 FC_LPORT_DBG(lport, "Unable to find Exchange Manager Anchor,"
2616 "fc_ctl <0x%x>, xid <0x%x>\n",
2617 f_ctl,
2618 (f_ctl & FC_FC_EX_CTX) ?
2619 ntohs(fh->fh_ox_id) :
2620 ntohs(fh->fh_rx_id));
2621 fc_frame_free(fp);
2622 return;
2623 }
2624
2625 /*
2626 * If frame is marked invalid, just drop it.
2627 */
2628 switch (fr_eof(fp)) {
2629 case FC_EOF_T:
2630 if (f_ctl & FC_FC_END_SEQ)
2631 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2632 /* fall through */
2633 case FC_EOF_N:
2634 if (fh->fh_type == FC_TYPE_BLS)
2635 fc_exch_recv_bls(ema->mp, fp);
2636 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2637 FC_FC_EX_CTX)
2638 fc_exch_recv_seq_resp(ema->mp, fp);
2639 else if (f_ctl & FC_FC_SEQ_CTX)
2640 fc_exch_recv_resp(ema->mp, fp);
2641 else /* no EX_CTX and no SEQ_CTX */
2642 fc_exch_recv_req(lport, ema->mp, fp);
2643 break;
2644 default:
2645 FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)",
2646 fr_eof(fp));
2647 fc_frame_free(fp);
2648 }
2649}
2650EXPORT_SYMBOL(fc_exch_recv);
2651
2652/**
2653 * fc_exch_init() - Initialize the exchange layer for a local port
2654 * @lport: The local port to initialize the exchange layer for
2655 */
2656int fc_exch_init(struct fc_lport *lport)
2657{
2658 if (!lport->tt.exch_mgr_reset)
2659 lport->tt.exch_mgr_reset = fc_exch_mgr_reset;
2660
2661 return 0;
2662}
2663EXPORT_SYMBOL(fc_exch_init);
2664
2665/**
2666 * fc_setup_exch_mgr() - Setup an exchange manager
2667 */
2668int fc_setup_exch_mgr(void)
2669{
2670 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2671 0, SLAB_HWCACHE_ALIGN, NULL);
2672 if (!fc_em_cachep)
2673 return -ENOMEM;
2674
2675 /*
2676 * Initialize fc_cpu_mask and fc_cpu_order. The
2677 * fc_cpu_mask is set for nr_cpu_ids rounded up
2678 * to order of 2's * power and order is stored
2679 * in fc_cpu_order as this is later required in
2680 * mapping between an exch id and exch array index
2681 * in per cpu exch pool.
2682 *
2683 * This round up is required to align fc_cpu_mask
2684 * to exchange id's lower bits such that all incoming
2685 * frames of an exchange gets delivered to the same
2686 * cpu on which exchange originated by simple bitwise
2687 * AND operation between fc_cpu_mask and exchange id.
2688 */
2689 fc_cpu_order = ilog2(roundup_pow_of_two(nr_cpu_ids));
2690 fc_cpu_mask = (1 << fc_cpu_order) - 1;
2691
2692 fc_exch_workqueue = create_singlethread_workqueue("fc_exch_workqueue");
2693 if (!fc_exch_workqueue)
2694 goto err;
2695 return 0;
2696err:
2697 kmem_cache_destroy(fc_em_cachep);
2698 return -ENOMEM;
2699}
2700
2701/**
2702 * fc_destroy_exch_mgr() - Destroy an exchange manager
2703 */
2704void fc_destroy_exch_mgr(void)
2705{
2706 destroy_workqueue(fc_exch_workqueue);
2707 kmem_cache_destroy(fc_em_cachep);
2708}
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#include <scsi/fc_encode.h>
24
25#include "fc_libfc.h"
26
27u16 fc_cpu_mask; /* cpu mask for possible cpus */
28EXPORT_SYMBOL(fc_cpu_mask);
29static u16 fc_cpu_order; /* 2's power to represent total possible cpus */
30static struct kmem_cache *fc_em_cachep; /* cache for exchanges */
31static struct workqueue_struct *fc_exch_workqueue;
32
33/*
34 * Structure and function definitions for managing Fibre Channel Exchanges
35 * and Sequences.
36 *
37 * The three primary structures used here are fc_exch_mgr, fc_exch, and fc_seq.
38 *
39 * fc_exch_mgr holds the exchange state for an N port
40 *
41 * fc_exch holds state for one exchange and links to its active sequence.
42 *
43 * fc_seq holds the state for an individual sequence.
44 */
45
46/**
47 * struct fc_exch_pool - Per cpu exchange pool
48 * @next_index: Next possible free exchange index
49 * @total_exches: Total allocated exchanges
50 * @lock: Exch pool lock
51 * @ex_list: List of exchanges
52 *
53 * This structure manages per cpu exchanges in array of exchange pointers.
54 * This array is allocated followed by struct fc_exch_pool memory for
55 * assigned range of exchanges to per cpu pool.
56 */
57struct fc_exch_pool {
58 spinlock_t lock;
59 struct list_head ex_list;
60 u16 next_index;
61 u16 total_exches;
62
63 /* two cache of free slot in exch array */
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 * @stats: Statistics structure
78 *
79 * This structure is the center for creating exchanges and sequences.
80 * It manages the allocation of exchange IDs.
81 */
82struct fc_exch_mgr {
83 struct fc_exch_pool __percpu *pool;
84 mempool_t *ep_pool;
85 struct fc_lport *lport;
86 enum fc_class class;
87 struct kref kref;
88 u16 min_xid;
89 u16 max_xid;
90 u16 pool_max_index;
91
92 struct {
93 atomic_t no_free_exch;
94 atomic_t no_free_exch_xid;
95 atomic_t xid_not_found;
96 atomic_t xid_busy;
97 atomic_t seq_not_found;
98 atomic_t non_bls_resp;
99 } stats;
100};
101
102/**
103 * struct fc_exch_mgr_anchor - primary structure for list of EMs
104 * @ema_list: Exchange Manager Anchor list
105 * @mp: Exchange Manager associated with this anchor
106 * @match: Routine to determine if this anchor's EM should be used
107 *
108 * When walking the list of anchors the match routine will be called
109 * for each anchor to determine if that EM should be used. The last
110 * anchor in the list will always match to handle any exchanges not
111 * handled by other EMs. The non-default EMs would be added to the
112 * anchor list by HW that provides offloads.
113 */
114struct fc_exch_mgr_anchor {
115 struct list_head ema_list;
116 struct fc_exch_mgr *mp;
117 bool (*match)(struct fc_frame *);
118};
119
120static void fc_exch_rrq(struct fc_exch *);
121static void fc_seq_ls_acc(struct fc_frame *);
122static void fc_seq_ls_rjt(struct fc_frame *, enum fc_els_rjt_reason,
123 enum fc_els_rjt_explan);
124static void fc_exch_els_rec(struct fc_frame *);
125static void fc_exch_els_rrq(struct fc_frame *);
126
127/*
128 * Internal implementation notes.
129 *
130 * The exchange manager is one by default in libfc but LLD may choose
131 * to have one per CPU. The sequence manager is one per exchange manager
132 * and currently never separated.
133 *
134 * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field
135 * assigned by the Sequence Initiator that shall be unique for a specific
136 * D_ID and S_ID pair while the Sequence is open." Note that it isn't
137 * qualified by exchange ID, which one might think it would be.
138 * In practice this limits the number of open sequences and exchanges to 256
139 * per session. For most targets we could treat this limit as per exchange.
140 *
141 * The exchange and its sequence are freed when the last sequence is received.
142 * It's possible for the remote port to leave an exchange open without
143 * sending any sequences.
144 *
145 * Notes on reference counts:
146 *
147 * Exchanges are reference counted and exchange gets freed when the reference
148 * count becomes zero.
149 *
150 * Timeouts:
151 * Sequences are timed out for E_D_TOV and R_A_TOV.
152 *
153 * Sequence event handling:
154 *
155 * The following events may occur on initiator sequences:
156 *
157 * Send.
158 * For now, the whole thing is sent.
159 * Receive ACK
160 * This applies only to class F.
161 * The sequence is marked complete.
162 * ULP completion.
163 * The upper layer calls fc_exch_done() when done
164 * with exchange and sequence tuple.
165 * RX-inferred completion.
166 * When we receive the next sequence on the same exchange, we can
167 * retire the previous sequence ID. (XXX not implemented).
168 * Timeout.
169 * R_A_TOV frees the sequence ID. If we're waiting for ACK,
170 * E_D_TOV causes abort and calls upper layer response handler
171 * with FC_EX_TIMEOUT error.
172 * Receive RJT
173 * XXX defer.
174 * Send ABTS
175 * On timeout.
176 *
177 * The following events may occur on recipient sequences:
178 *
179 * Receive
180 * Allocate sequence for first frame received.
181 * Hold during receive handler.
182 * Release when final frame received.
183 * Keep status of last N of these for the ELS RES command. XXX TBD.
184 * Receive ABTS
185 * Deallocate sequence
186 * Send RJT
187 * Deallocate
188 *
189 * For now, we neglect conditions where only part of a sequence was
190 * received or transmitted, or where out-of-order receipt is detected.
191 */
192
193/*
194 * Locking notes:
195 *
196 * The EM code run in a per-CPU worker thread.
197 *
198 * To protect against concurrency between a worker thread code and timers,
199 * sequence allocation and deallocation must be locked.
200 * - exchange refcnt can be done atomicly without locks.
201 * - sequence allocation must be locked by exch lock.
202 * - If the EM pool lock and ex_lock must be taken at the same time, then the
203 * EM pool lock must be taken before the ex_lock.
204 */
205
206/*
207 * opcode names for debugging.
208 */
209static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;
210
211/**
212 * fc_exch_name_lookup() - Lookup name by opcode
213 * @op: Opcode to be looked up
214 * @table: Opcode/name table
215 * @max_index: Index not to be exceeded
216 *
217 * This routine is used to determine a human-readable string identifying
218 * a R_CTL opcode.
219 */
220static inline const char *fc_exch_name_lookup(unsigned int op, char **table,
221 unsigned int max_index)
222{
223 const char *name = NULL;
224
225 if (op < max_index)
226 name = table[op];
227 if (!name)
228 name = "unknown";
229 return name;
230}
231
232/**
233 * fc_exch_rctl_name() - Wrapper routine for fc_exch_name_lookup()
234 * @op: The opcode to be looked up
235 */
236static const char *fc_exch_rctl_name(unsigned int op)
237{
238 return fc_exch_name_lookup(op, fc_exch_rctl_names,
239 ARRAY_SIZE(fc_exch_rctl_names));
240}
241
242/**
243 * fc_exch_hold() - Increment an exchange's reference count
244 * @ep: Echange to be held
245 */
246static inline void fc_exch_hold(struct fc_exch *ep)
247{
248 atomic_inc(&ep->ex_refcnt);
249}
250
251/**
252 * fc_exch_setup_hdr() - Initialize a FC header by initializing some fields
253 * and determine SOF and EOF.
254 * @ep: The exchange to that will use the header
255 * @fp: The frame whose header is to be modified
256 * @f_ctl: F_CTL bits that will be used for the frame header
257 *
258 * The fields initialized by this routine are: fh_ox_id, fh_rx_id,
259 * fh_seq_id, fh_seq_cnt and the SOF and EOF.
260 */
261static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,
262 u32 f_ctl)
263{
264 struct fc_frame_header *fh = fc_frame_header_get(fp);
265 u16 fill;
266
267 fr_sof(fp) = ep->class;
268 if (ep->seq.cnt)
269 fr_sof(fp) = fc_sof_normal(ep->class);
270
271 if (f_ctl & FC_FC_END_SEQ) {
272 fr_eof(fp) = FC_EOF_T;
273 if (fc_sof_needs_ack(ep->class))
274 fr_eof(fp) = FC_EOF_N;
275 /*
276 * From F_CTL.
277 * The number of fill bytes to make the length a 4-byte
278 * multiple is the low order 2-bits of the f_ctl.
279 * The fill itself will have been cleared by the frame
280 * allocation.
281 * After this, the length will be even, as expected by
282 * the transport.
283 */
284 fill = fr_len(fp) & 3;
285 if (fill) {
286 fill = 4 - fill;
287 /* TODO, this may be a problem with fragmented skb */
288 skb_put(fp_skb(fp), fill);
289 hton24(fh->fh_f_ctl, f_ctl | fill);
290 }
291 } else {
292 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
293 fr_eof(fp) = FC_EOF_N;
294 }
295
296 /* Initialize remaining fh fields from fc_fill_fc_hdr */
297 fh->fh_ox_id = htons(ep->oxid);
298 fh->fh_rx_id = htons(ep->rxid);
299 fh->fh_seq_id = ep->seq.id;
300 fh->fh_seq_cnt = htons(ep->seq.cnt);
301}
302
303/**
304 * fc_exch_release() - Decrement an exchange's reference count
305 * @ep: Exchange to be released
306 *
307 * If the reference count reaches zero and the exchange is complete,
308 * it is freed.
309 */
310static void fc_exch_release(struct fc_exch *ep)
311{
312 struct fc_exch_mgr *mp;
313
314 if (atomic_dec_and_test(&ep->ex_refcnt)) {
315 mp = ep->em;
316 if (ep->destructor)
317 ep->destructor(&ep->seq, ep->arg);
318 WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));
319 mempool_free(ep, mp->ep_pool);
320 }
321}
322
323/**
324 * fc_exch_timer_cancel() - cancel exch timer
325 * @ep: The exchange whose timer to be canceled
326 */
327static inline void fc_exch_timer_cancel(struct fc_exch *ep)
328{
329 if (cancel_delayed_work(&ep->timeout_work)) {
330 FC_EXCH_DBG(ep, "Exchange timer canceled\n");
331 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
332 }
333}
334
335/**
336 * fc_exch_timer_set_locked() - Start a timer for an exchange w/ the
337 * the exchange lock held
338 * @ep: The exchange whose timer will start
339 * @timer_msec: The timeout period
340 *
341 * Used for upper level protocols to time out the exchange.
342 * The timer is cancelled when it fires or when the exchange completes.
343 */
344static inline void fc_exch_timer_set_locked(struct fc_exch *ep,
345 unsigned int timer_msec)
346{
347 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
348 return;
349
350 FC_EXCH_DBG(ep, "Exchange timer armed : %d msecs\n", timer_msec);
351
352 fc_exch_hold(ep); /* hold for timer */
353 if (!queue_delayed_work(fc_exch_workqueue, &ep->timeout_work,
354 msecs_to_jiffies(timer_msec))) {
355 FC_EXCH_DBG(ep, "Exchange already queued\n");
356 fc_exch_release(ep);
357 }
358}
359
360/**
361 * fc_exch_timer_set() - Lock the exchange and set the timer
362 * @ep: The exchange whose timer will start
363 * @timer_msec: The timeout period
364 */
365static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec)
366{
367 spin_lock_bh(&ep->ex_lock);
368 fc_exch_timer_set_locked(ep, timer_msec);
369 spin_unlock_bh(&ep->ex_lock);
370}
371
372/**
373 * fc_exch_done_locked() - Complete an exchange with the exchange lock held
374 * @ep: The exchange that is complete
375 *
376 * Note: May sleep if invoked from outside a response handler.
377 */
378static int fc_exch_done_locked(struct fc_exch *ep)
379{
380 int rc = 1;
381
382 /*
383 * We must check for completion in case there are two threads
384 * tyring to complete this. But the rrq code will reuse the
385 * ep, and in that case we only clear the resp and set it as
386 * complete, so it can be reused by the timer to send the rrq.
387 */
388 if (ep->state & FC_EX_DONE)
389 return rc;
390 ep->esb_stat |= ESB_ST_COMPLETE;
391
392 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
393 ep->state |= FC_EX_DONE;
394 fc_exch_timer_cancel(ep);
395 rc = 0;
396 }
397 return rc;
398}
399
400static struct fc_exch fc_quarantine_exch;
401
402/**
403 * fc_exch_ptr_get() - Return an exchange from an exchange pool
404 * @pool: Exchange Pool to get an exchange from
405 * @index: Index of the exchange within the pool
406 *
407 * Use the index to get an exchange from within an exchange pool. exches
408 * will point to an array of exchange pointers. The index will select
409 * the exchange within the array.
410 */
411static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,
412 u16 index)
413{
414 struct fc_exch **exches = (struct fc_exch **)(pool + 1);
415 return exches[index];
416}
417
418/**
419 * fc_exch_ptr_set() - Assign an exchange to a slot in an exchange pool
420 * @pool: The pool to assign the exchange to
421 * @index: The index in the pool where the exchange will be assigned
422 * @ep: The exchange to assign to the pool
423 */
424static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
425 struct fc_exch *ep)
426{
427 ((struct fc_exch **)(pool + 1))[index] = ep;
428}
429
430/**
431 * fc_exch_delete() - Delete an exchange
432 * @ep: The exchange to be deleted
433 */
434static void fc_exch_delete(struct fc_exch *ep)
435{
436 struct fc_exch_pool *pool;
437 u16 index;
438
439 pool = ep->pool;
440 spin_lock_bh(&pool->lock);
441 WARN_ON(pool->total_exches <= 0);
442 pool->total_exches--;
443
444 /* update cache of free slot */
445 index = (ep->xid - ep->em->min_xid) >> fc_cpu_order;
446 if (!(ep->state & FC_EX_QUARANTINE)) {
447 if (pool->left == FC_XID_UNKNOWN)
448 pool->left = index;
449 else if (pool->right == FC_XID_UNKNOWN)
450 pool->right = index;
451 else
452 pool->next_index = index;
453 fc_exch_ptr_set(pool, index, NULL);
454 } else {
455 fc_exch_ptr_set(pool, index, &fc_quarantine_exch);
456 }
457 list_del(&ep->ex_list);
458 spin_unlock_bh(&pool->lock);
459 fc_exch_release(ep); /* drop hold for exch in mp */
460}
461
462static int fc_seq_send_locked(struct fc_lport *lport, struct fc_seq *sp,
463 struct fc_frame *fp)
464{
465 struct fc_exch *ep;
466 struct fc_frame_header *fh = fc_frame_header_get(fp);
467 int error = -ENXIO;
468 u32 f_ctl;
469 u8 fh_type = fh->fh_type;
470
471 ep = fc_seq_exch(sp);
472
473 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL)) {
474 fc_frame_free(fp);
475 goto out;
476 }
477
478 WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT));
479
480 f_ctl = ntoh24(fh->fh_f_ctl);
481 fc_exch_setup_hdr(ep, fp, f_ctl);
482 fr_encaps(fp) = ep->encaps;
483
484 /*
485 * update sequence count if this frame is carrying
486 * multiple FC frames when sequence offload is enabled
487 * by LLD.
488 */
489 if (fr_max_payload(fp))
490 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),
491 fr_max_payload(fp));
492 else
493 sp->cnt++;
494
495 /*
496 * Send the frame.
497 */
498 error = lport->tt.frame_send(lport, fp);
499
500 if (fh_type == FC_TYPE_BLS)
501 goto out;
502
503 /*
504 * Update the exchange and sequence flags,
505 * assuming all frames for the sequence have been sent.
506 * We can only be called to send once for each sequence.
507 */
508 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
509 if (f_ctl & FC_FC_SEQ_INIT)
510 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
511out:
512 return error;
513}
514
515/**
516 * fc_seq_send() - Send a frame using existing sequence/exchange pair
517 * @lport: The local port that the exchange will be sent on
518 * @sp: The sequence to be sent
519 * @fp: The frame to be sent on the exchange
520 *
521 * Note: The frame will be freed either by a direct call to fc_frame_free(fp)
522 * or indirectly by calling libfc_function_template.frame_send().
523 */
524int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp, struct fc_frame *fp)
525{
526 struct fc_exch *ep;
527 int error;
528 ep = fc_seq_exch(sp);
529 spin_lock_bh(&ep->ex_lock);
530 error = fc_seq_send_locked(lport, sp, fp);
531 spin_unlock_bh(&ep->ex_lock);
532 return error;
533}
534EXPORT_SYMBOL(fc_seq_send);
535
536/**
537 * fc_seq_alloc() - Allocate a sequence for a given exchange
538 * @ep: The exchange to allocate a new sequence for
539 * @seq_id: The sequence ID to be used
540 *
541 * We don't support multiple originated sequences on the same exchange.
542 * By implication, any previously originated sequence on this exchange
543 * is complete, and we reallocate the same sequence.
544 */
545static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
546{
547 struct fc_seq *sp;
548
549 sp = &ep->seq;
550 sp->ssb_stat = 0;
551 sp->cnt = 0;
552 sp->id = seq_id;
553 return sp;
554}
555
556/**
557 * fc_seq_start_next_locked() - Allocate a new sequence on the same
558 * exchange as the supplied sequence
559 * @sp: The sequence/exchange to get a new sequence for
560 */
561static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
562{
563 struct fc_exch *ep = fc_seq_exch(sp);
564
565 sp = fc_seq_alloc(ep, ep->seq_id++);
566 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
567 ep->f_ctl, sp->id);
568 return sp;
569}
570
571/**
572 * fc_seq_start_next() - Lock the exchange and get a new sequence
573 * for a given sequence/exchange pair
574 * @sp: The sequence/exchange to get a new exchange for
575 */
576struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
577{
578 struct fc_exch *ep = fc_seq_exch(sp);
579
580 spin_lock_bh(&ep->ex_lock);
581 sp = fc_seq_start_next_locked(sp);
582 spin_unlock_bh(&ep->ex_lock);
583
584 return sp;
585}
586EXPORT_SYMBOL(fc_seq_start_next);
587
588/*
589 * Set the response handler for the exchange associated with a sequence.
590 *
591 * Note: May sleep if invoked from outside a response handler.
592 */
593void fc_seq_set_resp(struct fc_seq *sp,
594 void (*resp)(struct fc_seq *, struct fc_frame *, void *),
595 void *arg)
596{
597 struct fc_exch *ep = fc_seq_exch(sp);
598 DEFINE_WAIT(wait);
599
600 spin_lock_bh(&ep->ex_lock);
601 while (ep->resp_active && ep->resp_task != current) {
602 prepare_to_wait(&ep->resp_wq, &wait, TASK_UNINTERRUPTIBLE);
603 spin_unlock_bh(&ep->ex_lock);
604
605 schedule();
606
607 spin_lock_bh(&ep->ex_lock);
608 }
609 finish_wait(&ep->resp_wq, &wait);
610 ep->resp = resp;
611 ep->arg = arg;
612 spin_unlock_bh(&ep->ex_lock);
613}
614EXPORT_SYMBOL(fc_seq_set_resp);
615
616/**
617 * fc_exch_abort_locked() - Abort an exchange
618 * @ep: The exchange to be aborted
619 * @timer_msec: The period of time to wait before aborting
620 *
621 * Abort an exchange and sequence. Generally called because of a
622 * exchange timeout or an abort from the upper layer.
623 *
624 * A timer_msec can be specified for abort timeout, if non-zero
625 * timer_msec value is specified then exchange resp handler
626 * will be called with timeout error if no response to abort.
627 *
628 * Locking notes: Called with exch lock held
629 *
630 * Return value: 0 on success else error code
631 */
632static int fc_exch_abort_locked(struct fc_exch *ep,
633 unsigned int timer_msec)
634{
635 struct fc_seq *sp;
636 struct fc_frame *fp;
637 int error;
638
639 FC_EXCH_DBG(ep, "exch: abort, time %d msecs\n", timer_msec);
640 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
641 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
642 FC_EXCH_DBG(ep, "exch: already completed esb %x state %x\n",
643 ep->esb_stat, ep->state);
644 return -ENXIO;
645 }
646
647 /*
648 * Send the abort on a new sequence if possible.
649 */
650 sp = fc_seq_start_next_locked(&ep->seq);
651 if (!sp)
652 return -ENOMEM;
653
654 if (timer_msec)
655 fc_exch_timer_set_locked(ep, timer_msec);
656
657 if (ep->sid) {
658 /*
659 * Send an abort for the sequence that timed out.
660 */
661 fp = fc_frame_alloc(ep->lp, 0);
662 if (fp) {
663 ep->esb_stat |= ESB_ST_SEQ_INIT;
664 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
665 FC_TYPE_BLS, FC_FC_END_SEQ |
666 FC_FC_SEQ_INIT, 0);
667 error = fc_seq_send_locked(ep->lp, sp, fp);
668 } else {
669 error = -ENOBUFS;
670 }
671 } else {
672 /*
673 * If not logged into the fabric, don't send ABTS but leave
674 * sequence active until next timeout.
675 */
676 error = 0;
677 }
678 ep->esb_stat |= ESB_ST_ABNORMAL;
679 return error;
680}
681
682/**
683 * fc_seq_exch_abort() - Abort an exchange and sequence
684 * @req_sp: The sequence to be aborted
685 * @timer_msec: The period of time to wait before aborting
686 *
687 * Generally called because of a timeout or an abort from the upper layer.
688 *
689 * Return value: 0 on success else error code
690 */
691int fc_seq_exch_abort(const struct fc_seq *req_sp, unsigned int timer_msec)
692{
693 struct fc_exch *ep;
694 int error;
695
696 ep = fc_seq_exch(req_sp);
697 spin_lock_bh(&ep->ex_lock);
698 error = fc_exch_abort_locked(ep, timer_msec);
699 spin_unlock_bh(&ep->ex_lock);
700 return error;
701}
702
703/**
704 * fc_invoke_resp() - invoke ep->resp()
705 *
706 * Notes:
707 * It is assumed that after initialization finished (this means the
708 * first unlock of ex_lock after fc_exch_alloc()) ep->resp and ep->arg are
709 * modified only via fc_seq_set_resp(). This guarantees that none of these
710 * two variables changes if ep->resp_active > 0.
711 *
712 * If an fc_seq_set_resp() call is busy modifying ep->resp and ep->arg when
713 * this function is invoked, the first spin_lock_bh() call in this function
714 * will wait until fc_seq_set_resp() has finished modifying these variables.
715 *
716 * Since fc_exch_done() invokes fc_seq_set_resp() it is guaranteed that that
717 * ep->resp() won't be invoked after fc_exch_done() has returned.
718 *
719 * The response handler itself may invoke fc_exch_done(), which will clear the
720 * ep->resp pointer.
721 *
722 * Return value:
723 * Returns true if and only if ep->resp has been invoked.
724 */
725static bool fc_invoke_resp(struct fc_exch *ep, struct fc_seq *sp,
726 struct fc_frame *fp)
727{
728 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
729 void *arg;
730 bool res = false;
731
732 spin_lock_bh(&ep->ex_lock);
733 ep->resp_active++;
734 if (ep->resp_task != current)
735 ep->resp_task = !ep->resp_task ? current : NULL;
736 resp = ep->resp;
737 arg = ep->arg;
738 spin_unlock_bh(&ep->ex_lock);
739
740 if (resp) {
741 resp(sp, fp, arg);
742 res = true;
743 }
744
745 spin_lock_bh(&ep->ex_lock);
746 if (--ep->resp_active == 0)
747 ep->resp_task = NULL;
748 spin_unlock_bh(&ep->ex_lock);
749
750 if (ep->resp_active == 0)
751 wake_up(&ep->resp_wq);
752
753 return res;
754}
755
756/**
757 * fc_exch_timeout() - Handle exchange timer expiration
758 * @work: The work_struct identifying the exchange that timed out
759 */
760static void fc_exch_timeout(struct work_struct *work)
761{
762 struct fc_exch *ep = container_of(work, struct fc_exch,
763 timeout_work.work);
764 struct fc_seq *sp = &ep->seq;
765 u32 e_stat;
766 int rc = 1;
767
768 FC_EXCH_DBG(ep, "Exchange timed out state %x\n", ep->state);
769
770 spin_lock_bh(&ep->ex_lock);
771 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
772 goto unlock;
773
774 e_stat = ep->esb_stat;
775 if (e_stat & ESB_ST_COMPLETE) {
776 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
777 spin_unlock_bh(&ep->ex_lock);
778 if (e_stat & ESB_ST_REC_QUAL)
779 fc_exch_rrq(ep);
780 goto done;
781 } else {
782 if (e_stat & ESB_ST_ABNORMAL)
783 rc = fc_exch_done_locked(ep);
784 spin_unlock_bh(&ep->ex_lock);
785 if (!rc)
786 fc_exch_delete(ep);
787 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_TIMEOUT));
788 fc_seq_set_resp(sp, NULL, ep->arg);
789 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
790 goto done;
791 }
792unlock:
793 spin_unlock_bh(&ep->ex_lock);
794done:
795 /*
796 * This release matches the hold taken when the timer was set.
797 */
798 fc_exch_release(ep);
799}
800
801/**
802 * fc_exch_em_alloc() - Allocate an exchange from a specified EM.
803 * @lport: The local port that the exchange is for
804 * @mp: The exchange manager that will allocate the exchange
805 *
806 * Returns pointer to allocated fc_exch with exch lock held.
807 */
808static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
809 struct fc_exch_mgr *mp)
810{
811 struct fc_exch *ep;
812 unsigned int cpu;
813 u16 index;
814 struct fc_exch_pool *pool;
815
816 /* allocate memory for exchange */
817 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);
818 if (!ep) {
819 atomic_inc(&mp->stats.no_free_exch);
820 goto out;
821 }
822 memset(ep, 0, sizeof(*ep));
823
824 cpu = get_cpu();
825 pool = per_cpu_ptr(mp->pool, cpu);
826 spin_lock_bh(&pool->lock);
827 put_cpu();
828
829 /* peek cache of free slot */
830 if (pool->left != FC_XID_UNKNOWN) {
831 if (!WARN_ON(fc_exch_ptr_get(pool, pool->left))) {
832 index = pool->left;
833 pool->left = FC_XID_UNKNOWN;
834 goto hit;
835 }
836 }
837 if (pool->right != FC_XID_UNKNOWN) {
838 if (!WARN_ON(fc_exch_ptr_get(pool, pool->right))) {
839 index = pool->right;
840 pool->right = FC_XID_UNKNOWN;
841 goto hit;
842 }
843 }
844
845 index = pool->next_index;
846 /* allocate new exch from pool */
847 while (fc_exch_ptr_get(pool, index)) {
848 index = index == mp->pool_max_index ? 0 : index + 1;
849 if (index == pool->next_index)
850 goto err;
851 }
852 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
853hit:
854 fc_exch_hold(ep); /* hold for exch in mp */
855 spin_lock_init(&ep->ex_lock);
856 /*
857 * Hold exch lock for caller to prevent fc_exch_reset()
858 * from releasing exch while fc_exch_alloc() caller is
859 * still working on exch.
860 */
861 spin_lock_bh(&ep->ex_lock);
862
863 fc_exch_ptr_set(pool, index, ep);
864 list_add_tail(&ep->ex_list, &pool->ex_list);
865 fc_seq_alloc(ep, ep->seq_id++);
866 pool->total_exches++;
867 spin_unlock_bh(&pool->lock);
868
869 /*
870 * update exchange
871 */
872 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
873 ep->em = mp;
874 ep->pool = pool;
875 ep->lp = lport;
876 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
877 ep->rxid = FC_XID_UNKNOWN;
878 ep->class = mp->class;
879 ep->resp_active = 0;
880 init_waitqueue_head(&ep->resp_wq);
881 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
882out:
883 return ep;
884err:
885 spin_unlock_bh(&pool->lock);
886 atomic_inc(&mp->stats.no_free_exch_xid);
887 mempool_free(ep, mp->ep_pool);
888 return NULL;
889}
890
891/**
892 * fc_exch_alloc() - Allocate an exchange from an EM on a
893 * local port's list of EMs.
894 * @lport: The local port that will own the exchange
895 * @fp: The FC frame that the exchange will be for
896 *
897 * This function walks the list of exchange manager(EM)
898 * anchors to select an EM for a new exchange allocation. The
899 * EM is selected when a NULL match function pointer is encountered
900 * or when a call to a match function returns true.
901 */
902static struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
903 struct fc_frame *fp)
904{
905 struct fc_exch_mgr_anchor *ema;
906 struct fc_exch *ep;
907
908 list_for_each_entry(ema, &lport->ema_list, ema_list) {
909 if (!ema->match || ema->match(fp)) {
910 ep = fc_exch_em_alloc(lport, ema->mp);
911 if (ep)
912 return ep;
913 }
914 }
915 return NULL;
916}
917
918/**
919 * fc_exch_find() - Lookup and hold an exchange
920 * @mp: The exchange manager to lookup the exchange from
921 * @xid: The XID of the exchange to look up
922 */
923static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
924{
925 struct fc_lport *lport = mp->lport;
926 struct fc_exch_pool *pool;
927 struct fc_exch *ep = NULL;
928 u16 cpu = xid & fc_cpu_mask;
929
930 if (xid == FC_XID_UNKNOWN)
931 return NULL;
932
933 if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
934 pr_err("host%u: lport %6.6x: xid %d invalid CPU %d\n:",
935 lport->host->host_no, lport->port_id, xid, cpu);
936 return NULL;
937 }
938
939 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
940 pool = per_cpu_ptr(mp->pool, cpu);
941 spin_lock_bh(&pool->lock);
942 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
943 if (ep == &fc_quarantine_exch) {
944 FC_LPORT_DBG(lport, "xid %x quarantined\n", xid);
945 ep = NULL;
946 }
947 if (ep) {
948 WARN_ON(ep->xid != xid);
949 fc_exch_hold(ep);
950 }
951 spin_unlock_bh(&pool->lock);
952 }
953 return ep;
954}
955
956
957/**
958 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and
959 * the memory allocated for the related objects may be freed.
960 * @sp: The sequence that has completed
961 *
962 * Note: May sleep if invoked from outside a response handler.
963 */
964void fc_exch_done(struct fc_seq *sp)
965{
966 struct fc_exch *ep = fc_seq_exch(sp);
967 int rc;
968
969 spin_lock_bh(&ep->ex_lock);
970 rc = fc_exch_done_locked(ep);
971 spin_unlock_bh(&ep->ex_lock);
972
973 fc_seq_set_resp(sp, NULL, ep->arg);
974 if (!rc)
975 fc_exch_delete(ep);
976}
977EXPORT_SYMBOL(fc_exch_done);
978
979/**
980 * fc_exch_resp() - Allocate a new exchange for a response frame
981 * @lport: The local port that the exchange was for
982 * @mp: The exchange manager to allocate the exchange from
983 * @fp: The response frame
984 *
985 * Sets the responder ID in the frame header.
986 */
987static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
988 struct fc_exch_mgr *mp,
989 struct fc_frame *fp)
990{
991 struct fc_exch *ep;
992 struct fc_frame_header *fh;
993
994 ep = fc_exch_alloc(lport, fp);
995 if (ep) {
996 ep->class = fc_frame_class(fp);
997
998 /*
999 * Set EX_CTX indicating we're responding on this exchange.
1000 */
1001 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
1002 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
1003 fh = fc_frame_header_get(fp);
1004 ep->sid = ntoh24(fh->fh_d_id);
1005 ep->did = ntoh24(fh->fh_s_id);
1006 ep->oid = ep->did;
1007
1008 /*
1009 * Allocated exchange has placed the XID in the
1010 * originator field. Move it to the responder field,
1011 * and set the originator XID from the frame.
1012 */
1013 ep->rxid = ep->xid;
1014 ep->oxid = ntohs(fh->fh_ox_id);
1015 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
1016 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
1017 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
1018
1019 fc_exch_hold(ep); /* hold for caller */
1020 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
1021 }
1022 return ep;
1023}
1024
1025/**
1026 * fc_seq_lookup_recip() - Find a sequence where the other end
1027 * originated the sequence
1028 * @lport: The local port that the frame was sent to
1029 * @mp: The Exchange Manager to lookup the exchange from
1030 * @fp: The frame associated with the sequence we're looking for
1031 *
1032 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
1033 * on the ep that should be released by the caller.
1034 */
1035static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
1036 struct fc_exch_mgr *mp,
1037 struct fc_frame *fp)
1038{
1039 struct fc_frame_header *fh = fc_frame_header_get(fp);
1040 struct fc_exch *ep = NULL;
1041 struct fc_seq *sp = NULL;
1042 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
1043 u32 f_ctl;
1044 u16 xid;
1045
1046 f_ctl = ntoh24(fh->fh_f_ctl);
1047 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
1048
1049 /*
1050 * Lookup or create the exchange if we will be creating the sequence.
1051 */
1052 if (f_ctl & FC_FC_EX_CTX) {
1053 xid = ntohs(fh->fh_ox_id); /* we originated exch */
1054 ep = fc_exch_find(mp, xid);
1055 if (!ep) {
1056 atomic_inc(&mp->stats.xid_not_found);
1057 reject = FC_RJT_OX_ID;
1058 goto out;
1059 }
1060 if (ep->rxid == FC_XID_UNKNOWN)
1061 ep->rxid = ntohs(fh->fh_rx_id);
1062 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
1063 reject = FC_RJT_OX_ID;
1064 goto rel;
1065 }
1066 } else {
1067 xid = ntohs(fh->fh_rx_id); /* we are the responder */
1068
1069 /*
1070 * Special case for MDS issuing an ELS TEST with a
1071 * bad rxid of 0.
1072 * XXX take this out once we do the proper reject.
1073 */
1074 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
1075 fc_frame_payload_op(fp) == ELS_TEST) {
1076 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
1077 xid = FC_XID_UNKNOWN;
1078 }
1079
1080 /*
1081 * new sequence - find the exchange
1082 */
1083 ep = fc_exch_find(mp, xid);
1084 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
1085 if (ep) {
1086 atomic_inc(&mp->stats.xid_busy);
1087 reject = FC_RJT_RX_ID;
1088 goto rel;
1089 }
1090 ep = fc_exch_resp(lport, mp, fp);
1091 if (!ep) {
1092 reject = FC_RJT_EXCH_EST; /* XXX */
1093 goto out;
1094 }
1095 xid = ep->xid; /* get our XID */
1096 } else if (!ep) {
1097 atomic_inc(&mp->stats.xid_not_found);
1098 reject = FC_RJT_RX_ID; /* XID not found */
1099 goto out;
1100 }
1101 }
1102
1103 spin_lock_bh(&ep->ex_lock);
1104 /*
1105 * At this point, we have the exchange held.
1106 * Find or create the sequence.
1107 */
1108 if (fc_sof_is_init(fr_sof(fp))) {
1109 sp = &ep->seq;
1110 sp->ssb_stat |= SSB_ST_RESP;
1111 sp->id = fh->fh_seq_id;
1112 } else {
1113 sp = &ep->seq;
1114 if (sp->id != fh->fh_seq_id) {
1115 atomic_inc(&mp->stats.seq_not_found);
1116 if (f_ctl & FC_FC_END_SEQ) {
1117 /*
1118 * Update sequence_id based on incoming last
1119 * frame of sequence exchange. This is needed
1120 * for FC target where DDP has been used
1121 * on target where, stack is indicated only
1122 * about last frame's (payload _header) header.
1123 * Whereas "seq_id" which is part of
1124 * frame_header is allocated by initiator
1125 * which is totally different from "seq_id"
1126 * allocated when XFER_RDY was sent by target.
1127 * To avoid false -ve which results into not
1128 * sending RSP, hence write request on other
1129 * end never finishes.
1130 */
1131 sp->ssb_stat |= SSB_ST_RESP;
1132 sp->id = fh->fh_seq_id;
1133 } else {
1134 spin_unlock_bh(&ep->ex_lock);
1135
1136 /* sequence/exch should exist */
1137 reject = FC_RJT_SEQ_ID;
1138 goto rel;
1139 }
1140 }
1141 }
1142 WARN_ON(ep != fc_seq_exch(sp));
1143
1144 if (f_ctl & FC_FC_SEQ_INIT)
1145 ep->esb_stat |= ESB_ST_SEQ_INIT;
1146 spin_unlock_bh(&ep->ex_lock);
1147
1148 fr_seq(fp) = sp;
1149out:
1150 return reject;
1151rel:
1152 fc_exch_done(&ep->seq);
1153 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
1154 return reject;
1155}
1156
1157/**
1158 * fc_seq_lookup_orig() - Find a sequence where this end
1159 * originated the sequence
1160 * @mp: The Exchange Manager to lookup the exchange from
1161 * @fp: The frame associated with the sequence we're looking for
1162 *
1163 * Does not hold the sequence for the caller.
1164 */
1165static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
1166 struct fc_frame *fp)
1167{
1168 struct fc_frame_header *fh = fc_frame_header_get(fp);
1169 struct fc_exch *ep;
1170 struct fc_seq *sp = NULL;
1171 u32 f_ctl;
1172 u16 xid;
1173
1174 f_ctl = ntoh24(fh->fh_f_ctl);
1175 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
1176 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
1177 ep = fc_exch_find(mp, xid);
1178 if (!ep)
1179 return NULL;
1180 if (ep->seq.id == fh->fh_seq_id) {
1181 /*
1182 * Save the RX_ID if we didn't previously know it.
1183 */
1184 sp = &ep->seq;
1185 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
1186 ep->rxid == FC_XID_UNKNOWN) {
1187 ep->rxid = ntohs(fh->fh_rx_id);
1188 }
1189 }
1190 fc_exch_release(ep);
1191 return sp;
1192}
1193
1194/**
1195 * fc_exch_set_addr() - Set the source and destination IDs for an exchange
1196 * @ep: The exchange to set the addresses for
1197 * @orig_id: The originator's ID
1198 * @resp_id: The responder's ID
1199 *
1200 * Note this must be done before the first sequence of the exchange is sent.
1201 */
1202static void fc_exch_set_addr(struct fc_exch *ep,
1203 u32 orig_id, u32 resp_id)
1204{
1205 ep->oid = orig_id;
1206 if (ep->esb_stat & ESB_ST_RESP) {
1207 ep->sid = resp_id;
1208 ep->did = orig_id;
1209 } else {
1210 ep->sid = orig_id;
1211 ep->did = resp_id;
1212 }
1213}
1214
1215/**
1216 * fc_seq_els_rsp_send() - Send an ELS response using information from
1217 * the existing sequence/exchange.
1218 * @fp: The received frame
1219 * @els_cmd: The ELS command to be sent
1220 * @els_data: The ELS data to be sent
1221 *
1222 * The received frame is not freed.
1223 */
1224void fc_seq_els_rsp_send(struct fc_frame *fp, enum fc_els_cmd els_cmd,
1225 struct fc_seq_els_data *els_data)
1226{
1227 switch (els_cmd) {
1228 case ELS_LS_RJT:
1229 fc_seq_ls_rjt(fp, els_data->reason, els_data->explan);
1230 break;
1231 case ELS_LS_ACC:
1232 fc_seq_ls_acc(fp);
1233 break;
1234 case ELS_RRQ:
1235 fc_exch_els_rrq(fp);
1236 break;
1237 case ELS_REC:
1238 fc_exch_els_rec(fp);
1239 break;
1240 default:
1241 FC_LPORT_DBG(fr_dev(fp), "Invalid ELS CMD:%x\n", els_cmd);
1242 }
1243}
1244EXPORT_SYMBOL_GPL(fc_seq_els_rsp_send);
1245
1246/**
1247 * fc_seq_send_last() - Send a sequence that is the last in the exchange
1248 * @sp: The sequence that is to be sent
1249 * @fp: The frame that will be sent on the sequence
1250 * @rctl: The R_CTL information to be sent
1251 * @fh_type: The frame header type
1252 */
1253static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
1254 enum fc_rctl rctl, enum fc_fh_type fh_type)
1255{
1256 u32 f_ctl;
1257 struct fc_exch *ep = fc_seq_exch(sp);
1258
1259 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
1260 f_ctl |= ep->f_ctl;
1261 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
1262 fc_seq_send_locked(ep->lp, sp, fp);
1263}
1264
1265/**
1266 * fc_seq_send_ack() - Send an acknowledgement that we've received a frame
1267 * @sp: The sequence to send the ACK on
1268 * @rx_fp: The received frame that is being acknoledged
1269 *
1270 * Send ACK_1 (or equiv.) indicating we received something.
1271 */
1272static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
1273{
1274 struct fc_frame *fp;
1275 struct fc_frame_header *rx_fh;
1276 struct fc_frame_header *fh;
1277 struct fc_exch *ep = fc_seq_exch(sp);
1278 struct fc_lport *lport = ep->lp;
1279 unsigned int f_ctl;
1280
1281 /*
1282 * Don't send ACKs for class 3.
1283 */
1284 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
1285 fp = fc_frame_alloc(lport, 0);
1286 if (!fp) {
1287 FC_EXCH_DBG(ep, "Drop ACK request, out of memory\n");
1288 return;
1289 }
1290
1291 fh = fc_frame_header_get(fp);
1292 fh->fh_r_ctl = FC_RCTL_ACK_1;
1293 fh->fh_type = FC_TYPE_BLS;
1294
1295 /*
1296 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1297 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1298 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1299 * Last ACK uses bits 7-6 (continue sequence),
1300 * bits 5-4 are meaningful (what kind of ACK to use).
1301 */
1302 rx_fh = fc_frame_header_get(rx_fp);
1303 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1304 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1305 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
1306 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
1307 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1308 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1309 hton24(fh->fh_f_ctl, f_ctl);
1310
1311 fc_exch_setup_hdr(ep, fp, f_ctl);
1312 fh->fh_seq_id = rx_fh->fh_seq_id;
1313 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1314 fh->fh_parm_offset = htonl(1); /* ack single frame */
1315
1316 fr_sof(fp) = fr_sof(rx_fp);
1317 if (f_ctl & FC_FC_END_SEQ)
1318 fr_eof(fp) = FC_EOF_T;
1319 else
1320 fr_eof(fp) = FC_EOF_N;
1321
1322 lport->tt.frame_send(lport, fp);
1323 }
1324}
1325
1326/**
1327 * fc_exch_send_ba_rjt() - Send BLS Reject
1328 * @rx_fp: The frame being rejected
1329 * @reason: The reason the frame is being rejected
1330 * @explan: The explanation for the rejection
1331 *
1332 * This is for rejecting BA_ABTS only.
1333 */
1334static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
1335 enum fc_ba_rjt_reason reason,
1336 enum fc_ba_rjt_explan explan)
1337{
1338 struct fc_frame *fp;
1339 struct fc_frame_header *rx_fh;
1340 struct fc_frame_header *fh;
1341 struct fc_ba_rjt *rp;
1342 struct fc_seq *sp;
1343 struct fc_lport *lport;
1344 unsigned int f_ctl;
1345
1346 lport = fr_dev(rx_fp);
1347 sp = fr_seq(rx_fp);
1348 fp = fc_frame_alloc(lport, sizeof(*rp));
1349 if (!fp) {
1350 FC_EXCH_DBG(fc_seq_exch(sp),
1351 "Drop BA_RJT request, out of memory\n");
1352 return;
1353 }
1354 fh = fc_frame_header_get(fp);
1355 rx_fh = fc_frame_header_get(rx_fp);
1356
1357 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1358
1359 rp = fc_frame_payload_get(fp, sizeof(*rp));
1360 rp->br_reason = reason;
1361 rp->br_explan = explan;
1362
1363 /*
1364 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1365 */
1366 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1367 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1368 fh->fh_ox_id = rx_fh->fh_ox_id;
1369 fh->fh_rx_id = rx_fh->fh_rx_id;
1370 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1371 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1372 fh->fh_type = FC_TYPE_BLS;
1373
1374 /*
1375 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1376 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1377 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1378 * Last ACK uses bits 7-6 (continue sequence),
1379 * bits 5-4 are meaningful (what kind of ACK to use).
1380 * Always set LAST_SEQ, END_SEQ.
1381 */
1382 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1383 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1384 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1385 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1386 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1387 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1388 f_ctl &= ~FC_FC_FIRST_SEQ;
1389 hton24(fh->fh_f_ctl, f_ctl);
1390
1391 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1392 fr_eof(fp) = FC_EOF_T;
1393 if (fc_sof_needs_ack(fr_sof(fp)))
1394 fr_eof(fp) = FC_EOF_N;
1395
1396 lport->tt.frame_send(lport, fp);
1397}
1398
1399/**
1400 * fc_exch_recv_abts() - Handle an incoming ABTS
1401 * @ep: The exchange the abort was on
1402 * @rx_fp: The ABTS frame
1403 *
1404 * This would be for target mode usually, but could be due to lost
1405 * FCP transfer ready, confirm or RRQ. We always handle this as an
1406 * exchange abort, ignoring the parameter.
1407 */
1408static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1409{
1410 struct fc_frame *fp;
1411 struct fc_ba_acc *ap;
1412 struct fc_frame_header *fh;
1413 struct fc_seq *sp;
1414
1415 if (!ep)
1416 goto reject;
1417
1418 FC_EXCH_DBG(ep, "exch: ABTS received\n");
1419 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1420 if (!fp) {
1421 FC_EXCH_DBG(ep, "Drop ABTS request, out of memory\n");
1422 goto free;
1423 }
1424
1425 spin_lock_bh(&ep->ex_lock);
1426 if (ep->esb_stat & ESB_ST_COMPLETE) {
1427 spin_unlock_bh(&ep->ex_lock);
1428 FC_EXCH_DBG(ep, "exch: ABTS rejected, exchange complete\n");
1429 fc_frame_free(fp);
1430 goto reject;
1431 }
1432 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
1433 ep->esb_stat |= ESB_ST_REC_QUAL;
1434 fc_exch_hold(ep); /* hold for REC_QUAL */
1435 }
1436 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1437 fh = fc_frame_header_get(fp);
1438 ap = fc_frame_payload_get(fp, sizeof(*ap));
1439 memset(ap, 0, sizeof(*ap));
1440 sp = &ep->seq;
1441 ap->ba_high_seq_cnt = htons(0xffff);
1442 if (sp->ssb_stat & SSB_ST_RESP) {
1443 ap->ba_seq_id = sp->id;
1444 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1445 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1446 ap->ba_low_seq_cnt = htons(sp->cnt);
1447 }
1448 sp = fc_seq_start_next_locked(sp);
1449 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1450 ep->esb_stat |= ESB_ST_ABNORMAL;
1451 spin_unlock_bh(&ep->ex_lock);
1452
1453free:
1454 fc_frame_free(rx_fp);
1455 return;
1456
1457reject:
1458 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1459 goto free;
1460}
1461
1462/**
1463 * fc_seq_assign() - Assign exchange and sequence for incoming request
1464 * @lport: The local port that received the request
1465 * @fp: The request frame
1466 *
1467 * On success, the sequence pointer will be returned and also in fr_seq(@fp).
1468 * A reference will be held on the exchange/sequence for the caller, which
1469 * must call fc_seq_release().
1470 */
1471struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)
1472{
1473 struct fc_exch_mgr_anchor *ema;
1474
1475 WARN_ON(lport != fr_dev(fp));
1476 WARN_ON(fr_seq(fp));
1477 fr_seq(fp) = NULL;
1478
1479 list_for_each_entry(ema, &lport->ema_list, ema_list)
1480 if ((!ema->match || ema->match(fp)) &&
1481 fc_seq_lookup_recip(lport, ema->mp, fp) == FC_RJT_NONE)
1482 break;
1483 return fr_seq(fp);
1484}
1485EXPORT_SYMBOL(fc_seq_assign);
1486
1487/**
1488 * fc_seq_release() - Release the hold
1489 * @sp: The sequence.
1490 */
1491void fc_seq_release(struct fc_seq *sp)
1492{
1493 fc_exch_release(fc_seq_exch(sp));
1494}
1495EXPORT_SYMBOL(fc_seq_release);
1496
1497/**
1498 * fc_exch_recv_req() - Handler for an incoming request
1499 * @lport: The local port that received the request
1500 * @mp: The EM that the exchange is on
1501 * @fp: The request frame
1502 *
1503 * This is used when the other end is originating the exchange
1504 * and the sequence.
1505 */
1506static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp,
1507 struct fc_frame *fp)
1508{
1509 struct fc_frame_header *fh = fc_frame_header_get(fp);
1510 struct fc_seq *sp = NULL;
1511 struct fc_exch *ep = NULL;
1512 enum fc_pf_rjt_reason reject;
1513
1514 /* We can have the wrong fc_lport at this point with NPIV, which is a
1515 * problem now that we know a new exchange needs to be allocated
1516 */
1517 lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id));
1518 if (!lport) {
1519 fc_frame_free(fp);
1520 return;
1521 }
1522 fr_dev(fp) = lport;
1523
1524 BUG_ON(fr_seq(fp)); /* XXX remove later */
1525
1526 /*
1527 * If the RX_ID is 0xffff, don't allocate an exchange.
1528 * The upper-level protocol may request one later, if needed.
1529 */
1530 if (fh->fh_rx_id == htons(FC_XID_UNKNOWN))
1531 return fc_lport_recv(lport, fp);
1532
1533 reject = fc_seq_lookup_recip(lport, mp, fp);
1534 if (reject == FC_RJT_NONE) {
1535 sp = fr_seq(fp); /* sequence will be held */
1536 ep = fc_seq_exch(sp);
1537 fc_seq_send_ack(sp, fp);
1538 ep->encaps = fr_encaps(fp);
1539
1540 /*
1541 * Call the receive function.
1542 *
1543 * The receive function may allocate a new sequence
1544 * over the old one, so we shouldn't change the
1545 * sequence after this.
1546 *
1547 * The frame will be freed by the receive function.
1548 * If new exch resp handler is valid then call that
1549 * first.
1550 */
1551 if (!fc_invoke_resp(ep, sp, fp))
1552 fc_lport_recv(lport, fp);
1553 fc_exch_release(ep); /* release from lookup */
1554 } else {
1555 FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n",
1556 reject);
1557 fc_frame_free(fp);
1558 }
1559}
1560
1561/**
1562 * fc_exch_recv_seq_resp() - Handler for an incoming response where the other
1563 * end is the originator of the sequence that is a
1564 * response to our initial exchange
1565 * @mp: The EM that the exchange is on
1566 * @fp: The response frame
1567 */
1568static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1569{
1570 struct fc_frame_header *fh = fc_frame_header_get(fp);
1571 struct fc_seq *sp;
1572 struct fc_exch *ep;
1573 enum fc_sof sof;
1574 u32 f_ctl;
1575 int rc;
1576
1577 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1578 if (!ep) {
1579 atomic_inc(&mp->stats.xid_not_found);
1580 goto out;
1581 }
1582 if (ep->esb_stat & ESB_ST_COMPLETE) {
1583 atomic_inc(&mp->stats.xid_not_found);
1584 goto rel;
1585 }
1586 if (ep->rxid == FC_XID_UNKNOWN)
1587 ep->rxid = ntohs(fh->fh_rx_id);
1588 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1589 atomic_inc(&mp->stats.xid_not_found);
1590 goto rel;
1591 }
1592 if (ep->did != ntoh24(fh->fh_s_id) &&
1593 ep->did != FC_FID_FLOGI) {
1594 atomic_inc(&mp->stats.xid_not_found);
1595 goto rel;
1596 }
1597 sof = fr_sof(fp);
1598 sp = &ep->seq;
1599 if (fc_sof_is_init(sof)) {
1600 sp->ssb_stat |= SSB_ST_RESP;
1601 sp->id = fh->fh_seq_id;
1602 }
1603
1604 f_ctl = ntoh24(fh->fh_f_ctl);
1605 fr_seq(fp) = sp;
1606
1607 spin_lock_bh(&ep->ex_lock);
1608 if (f_ctl & FC_FC_SEQ_INIT)
1609 ep->esb_stat |= ESB_ST_SEQ_INIT;
1610 spin_unlock_bh(&ep->ex_lock);
1611
1612 if (fc_sof_needs_ack(sof))
1613 fc_seq_send_ack(sp, fp);
1614
1615 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1616 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1617 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1618 spin_lock_bh(&ep->ex_lock);
1619 rc = fc_exch_done_locked(ep);
1620 WARN_ON(fc_seq_exch(sp) != ep);
1621 spin_unlock_bh(&ep->ex_lock);
1622 if (!rc)
1623 fc_exch_delete(ep);
1624 }
1625
1626 /*
1627 * Call the receive function.
1628 * The sequence is held (has a refcnt) for us,
1629 * but not for the receive function.
1630 *
1631 * The receive function may allocate a new sequence
1632 * over the old one, so we shouldn't change the
1633 * sequence after this.
1634 *
1635 * The frame will be freed by the receive function.
1636 * If new exch resp handler is valid then call that
1637 * first.
1638 */
1639 if (!fc_invoke_resp(ep, sp, fp))
1640 fc_frame_free(fp);
1641
1642 fc_exch_release(ep);
1643 return;
1644rel:
1645 fc_exch_release(ep);
1646out:
1647 fc_frame_free(fp);
1648}
1649
1650/**
1651 * fc_exch_recv_resp() - Handler for a sequence where other end is
1652 * responding to our sequence
1653 * @mp: The EM that the exchange is on
1654 * @fp: The response frame
1655 */
1656static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1657{
1658 struct fc_seq *sp;
1659
1660 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1661
1662 if (!sp)
1663 atomic_inc(&mp->stats.xid_not_found);
1664 else
1665 atomic_inc(&mp->stats.non_bls_resp);
1666
1667 fc_frame_free(fp);
1668}
1669
1670/**
1671 * fc_exch_abts_resp() - Handler for a response to an ABT
1672 * @ep: The exchange that the frame is on
1673 * @fp: The response frame
1674 *
1675 * This response would be to an ABTS cancelling an exchange or sequence.
1676 * The response can be either BA_ACC or BA_RJT
1677 */
1678static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1679{
1680 struct fc_frame_header *fh;
1681 struct fc_ba_acc *ap;
1682 struct fc_seq *sp;
1683 u16 low;
1684 u16 high;
1685 int rc = 1, has_rec = 0;
1686
1687 fh = fc_frame_header_get(fp);
1688 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1689 fc_exch_rctl_name(fh->fh_r_ctl));
1690
1691 if (cancel_delayed_work_sync(&ep->timeout_work)) {
1692 FC_EXCH_DBG(ep, "Exchange timer canceled due to ABTS response\n");
1693 fc_exch_release(ep); /* release from pending timer hold */
1694 }
1695
1696 spin_lock_bh(&ep->ex_lock);
1697 switch (fh->fh_r_ctl) {
1698 case FC_RCTL_BA_ACC:
1699 ap = fc_frame_payload_get(fp, sizeof(*ap));
1700 if (!ap)
1701 break;
1702
1703 /*
1704 * Decide whether to establish a Recovery Qualifier.
1705 * We do this if there is a non-empty SEQ_CNT range and
1706 * SEQ_ID is the same as the one we aborted.
1707 */
1708 low = ntohs(ap->ba_low_seq_cnt);
1709 high = ntohs(ap->ba_high_seq_cnt);
1710 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1711 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1712 ap->ba_seq_id == ep->seq_id) && low != high) {
1713 ep->esb_stat |= ESB_ST_REC_QUAL;
1714 fc_exch_hold(ep); /* hold for recovery qualifier */
1715 has_rec = 1;
1716 }
1717 break;
1718 case FC_RCTL_BA_RJT:
1719 break;
1720 default:
1721 break;
1722 }
1723
1724 /* do we need to do some other checks here. Can we reuse more of
1725 * fc_exch_recv_seq_resp
1726 */
1727 sp = &ep->seq;
1728 /*
1729 * do we want to check END_SEQ as well as LAST_SEQ here?
1730 */
1731 if (ep->fh_type != FC_TYPE_FCP &&
1732 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1733 rc = fc_exch_done_locked(ep);
1734 spin_unlock_bh(&ep->ex_lock);
1735
1736 fc_exch_hold(ep);
1737 if (!rc)
1738 fc_exch_delete(ep);
1739 if (!fc_invoke_resp(ep, sp, fp))
1740 fc_frame_free(fp);
1741 if (has_rec)
1742 fc_exch_timer_set(ep, ep->r_a_tov);
1743 fc_exch_release(ep);
1744}
1745
1746/**
1747 * fc_exch_recv_bls() - Handler for a BLS sequence
1748 * @mp: The EM that the exchange is on
1749 * @fp: The request frame
1750 *
1751 * The BLS frame is always a sequence initiated by the remote side.
1752 * We may be either the originator or recipient of the exchange.
1753 */
1754static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1755{
1756 struct fc_frame_header *fh;
1757 struct fc_exch *ep;
1758 u32 f_ctl;
1759
1760 fh = fc_frame_header_get(fp);
1761 f_ctl = ntoh24(fh->fh_f_ctl);
1762 fr_seq(fp) = NULL;
1763
1764 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1765 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1766 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1767 spin_lock_bh(&ep->ex_lock);
1768 ep->esb_stat |= ESB_ST_SEQ_INIT;
1769 spin_unlock_bh(&ep->ex_lock);
1770 }
1771 if (f_ctl & FC_FC_SEQ_CTX) {
1772 /*
1773 * A response to a sequence we initiated.
1774 * This should only be ACKs for class 2 or F.
1775 */
1776 switch (fh->fh_r_ctl) {
1777 case FC_RCTL_ACK_1:
1778 case FC_RCTL_ACK_0:
1779 break;
1780 default:
1781 if (ep)
1782 FC_EXCH_DBG(ep, "BLS rctl %x - %s received\n",
1783 fh->fh_r_ctl,
1784 fc_exch_rctl_name(fh->fh_r_ctl));
1785 break;
1786 }
1787 fc_frame_free(fp);
1788 } else {
1789 switch (fh->fh_r_ctl) {
1790 case FC_RCTL_BA_RJT:
1791 case FC_RCTL_BA_ACC:
1792 if (ep)
1793 fc_exch_abts_resp(ep, fp);
1794 else
1795 fc_frame_free(fp);
1796 break;
1797 case FC_RCTL_BA_ABTS:
1798 if (ep)
1799 fc_exch_recv_abts(ep, fp);
1800 else
1801 fc_frame_free(fp);
1802 break;
1803 default: /* ignore junk */
1804 fc_frame_free(fp);
1805 break;
1806 }
1807 }
1808 if (ep)
1809 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1810}
1811
1812/**
1813 * fc_seq_ls_acc() - Accept sequence with LS_ACC
1814 * @rx_fp: The received frame, not freed here.
1815 *
1816 * If this fails due to allocation or transmit congestion, assume the
1817 * originator will repeat the sequence.
1818 */
1819static void fc_seq_ls_acc(struct fc_frame *rx_fp)
1820{
1821 struct fc_lport *lport;
1822 struct fc_els_ls_acc *acc;
1823 struct fc_frame *fp;
1824 struct fc_seq *sp;
1825
1826 lport = fr_dev(rx_fp);
1827 sp = fr_seq(rx_fp);
1828 fp = fc_frame_alloc(lport, sizeof(*acc));
1829 if (!fp) {
1830 FC_EXCH_DBG(fc_seq_exch(sp),
1831 "exch: drop LS_ACC, out of memory\n");
1832 return;
1833 }
1834 acc = fc_frame_payload_get(fp, sizeof(*acc));
1835 memset(acc, 0, sizeof(*acc));
1836 acc->la_cmd = ELS_LS_ACC;
1837 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1838 lport->tt.frame_send(lport, fp);
1839}
1840
1841/**
1842 * fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT
1843 * @rx_fp: The received frame, not freed here.
1844 * @reason: The reason the sequence is being rejected
1845 * @explan: The explanation for the rejection
1846 *
1847 * If this fails due to allocation or transmit congestion, assume the
1848 * originator will repeat the sequence.
1849 */
1850static void fc_seq_ls_rjt(struct fc_frame *rx_fp, enum fc_els_rjt_reason reason,
1851 enum fc_els_rjt_explan explan)
1852{
1853 struct fc_lport *lport;
1854 struct fc_els_ls_rjt *rjt;
1855 struct fc_frame *fp;
1856 struct fc_seq *sp;
1857
1858 lport = fr_dev(rx_fp);
1859 sp = fr_seq(rx_fp);
1860 fp = fc_frame_alloc(lport, sizeof(*rjt));
1861 if (!fp) {
1862 FC_EXCH_DBG(fc_seq_exch(sp),
1863 "exch: drop LS_ACC, out of memory\n");
1864 return;
1865 }
1866 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1867 memset(rjt, 0, sizeof(*rjt));
1868 rjt->er_cmd = ELS_LS_RJT;
1869 rjt->er_reason = reason;
1870 rjt->er_explan = explan;
1871 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1872 lport->tt.frame_send(lport, fp);
1873}
1874
1875/**
1876 * fc_exch_reset() - Reset an exchange
1877 * @ep: The exchange to be reset
1878 *
1879 * Note: May sleep if invoked from outside a response handler.
1880 */
1881static void fc_exch_reset(struct fc_exch *ep)
1882{
1883 struct fc_seq *sp;
1884 int rc = 1;
1885
1886 spin_lock_bh(&ep->ex_lock);
1887 ep->state |= FC_EX_RST_CLEANUP;
1888 fc_exch_timer_cancel(ep);
1889 if (ep->esb_stat & ESB_ST_REC_QUAL)
1890 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1891 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1892 sp = &ep->seq;
1893 rc = fc_exch_done_locked(ep);
1894 spin_unlock_bh(&ep->ex_lock);
1895
1896 fc_exch_hold(ep);
1897
1898 if (!rc)
1899 fc_exch_delete(ep);
1900
1901 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_CLOSED));
1902 fc_seq_set_resp(sp, NULL, ep->arg);
1903 fc_exch_release(ep);
1904}
1905
1906/**
1907 * fc_exch_pool_reset() - Reset a per cpu exchange pool
1908 * @lport: The local port that the exchange pool is on
1909 * @pool: The exchange pool to be reset
1910 * @sid: The source ID
1911 * @did: The destination ID
1912 *
1913 * Resets a per cpu exches pool, releasing all of its sequences
1914 * and exchanges. If sid is non-zero then reset only exchanges
1915 * we sourced from the local port's FID. If did is non-zero then
1916 * only reset exchanges destined for the local port's FID.
1917 */
1918static void fc_exch_pool_reset(struct fc_lport *lport,
1919 struct fc_exch_pool *pool,
1920 u32 sid, u32 did)
1921{
1922 struct fc_exch *ep;
1923 struct fc_exch *next;
1924
1925 spin_lock_bh(&pool->lock);
1926restart:
1927 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1928 if ((lport == ep->lp) &&
1929 (sid == 0 || sid == ep->sid) &&
1930 (did == 0 || did == ep->did)) {
1931 fc_exch_hold(ep);
1932 spin_unlock_bh(&pool->lock);
1933
1934 fc_exch_reset(ep);
1935
1936 fc_exch_release(ep);
1937 spin_lock_bh(&pool->lock);
1938
1939 /*
1940 * must restart loop incase while lock
1941 * was down multiple eps were released.
1942 */
1943 goto restart;
1944 }
1945 }
1946 pool->next_index = 0;
1947 pool->left = FC_XID_UNKNOWN;
1948 pool->right = FC_XID_UNKNOWN;
1949 spin_unlock_bh(&pool->lock);
1950}
1951
1952/**
1953 * fc_exch_mgr_reset() - Reset all EMs of a local port
1954 * @lport: The local port whose EMs are to be reset
1955 * @sid: The source ID
1956 * @did: The destination ID
1957 *
1958 * Reset all EMs associated with a given local port. Release all
1959 * sequences and exchanges. If sid is non-zero then reset only the
1960 * exchanges sent from the local port's FID. If did is non-zero then
1961 * reset only exchanges destined for the local port's FID.
1962 */
1963void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1964{
1965 struct fc_exch_mgr_anchor *ema;
1966 unsigned int cpu;
1967
1968 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1969 for_each_possible_cpu(cpu)
1970 fc_exch_pool_reset(lport,
1971 per_cpu_ptr(ema->mp->pool, cpu),
1972 sid, did);
1973 }
1974}
1975EXPORT_SYMBOL(fc_exch_mgr_reset);
1976
1977/**
1978 * fc_exch_lookup() - find an exchange
1979 * @lport: The local port
1980 * @xid: The exchange ID
1981 *
1982 * Returns exchange pointer with hold for caller, or NULL if not found.
1983 */
1984static struct fc_exch *fc_exch_lookup(struct fc_lport *lport, u32 xid)
1985{
1986 struct fc_exch_mgr_anchor *ema;
1987
1988 list_for_each_entry(ema, &lport->ema_list, ema_list)
1989 if (ema->mp->min_xid <= xid && xid <= ema->mp->max_xid)
1990 return fc_exch_find(ema->mp, xid);
1991 return NULL;
1992}
1993
1994/**
1995 * fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests
1996 * @rfp: The REC frame, not freed here.
1997 *
1998 * Note that the requesting port may be different than the S_ID in the request.
1999 */
2000static void fc_exch_els_rec(struct fc_frame *rfp)
2001{
2002 struct fc_lport *lport;
2003 struct fc_frame *fp;
2004 struct fc_exch *ep;
2005 struct fc_els_rec *rp;
2006 struct fc_els_rec_acc *acc;
2007 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
2008 enum fc_els_rjt_explan explan;
2009 u32 sid;
2010 u16 xid, rxid, oxid;
2011
2012 lport = fr_dev(rfp);
2013 rp = fc_frame_payload_get(rfp, sizeof(*rp));
2014 explan = ELS_EXPL_INV_LEN;
2015 if (!rp)
2016 goto reject;
2017 sid = ntoh24(rp->rec_s_id);
2018 rxid = ntohs(rp->rec_rx_id);
2019 oxid = ntohs(rp->rec_ox_id);
2020
2021 explan = ELS_EXPL_OXID_RXID;
2022 if (sid == fc_host_port_id(lport->host))
2023 xid = oxid;
2024 else
2025 xid = rxid;
2026 if (xid == FC_XID_UNKNOWN) {
2027 FC_LPORT_DBG(lport,
2028 "REC request from %x: invalid rxid %x oxid %x\n",
2029 sid, rxid, oxid);
2030 goto reject;
2031 }
2032 ep = fc_exch_lookup(lport, xid);
2033 if (!ep) {
2034 FC_LPORT_DBG(lport,
2035 "REC request from %x: rxid %x oxid %x not found\n",
2036 sid, rxid, oxid);
2037 goto reject;
2038 }
2039 FC_EXCH_DBG(ep, "REC request from %x: rxid %x oxid %x\n",
2040 sid, rxid, oxid);
2041 if (ep->oid != sid || oxid != ep->oxid)
2042 goto rel;
2043 if (rxid != FC_XID_UNKNOWN && rxid != ep->rxid)
2044 goto rel;
2045 fp = fc_frame_alloc(lport, sizeof(*acc));
2046 if (!fp) {
2047 FC_EXCH_DBG(ep, "Drop REC request, out of memory\n");
2048 goto out;
2049 }
2050
2051 acc = fc_frame_payload_get(fp, sizeof(*acc));
2052 memset(acc, 0, sizeof(*acc));
2053 acc->reca_cmd = ELS_LS_ACC;
2054 acc->reca_ox_id = rp->rec_ox_id;
2055 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
2056 acc->reca_rx_id = htons(ep->rxid);
2057 if (ep->sid == ep->oid)
2058 hton24(acc->reca_rfid, ep->did);
2059 else
2060 hton24(acc->reca_rfid, ep->sid);
2061 acc->reca_fc4value = htonl(ep->seq.rec_data);
2062 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
2063 ESB_ST_SEQ_INIT |
2064 ESB_ST_COMPLETE));
2065 fc_fill_reply_hdr(fp, rfp, FC_RCTL_ELS_REP, 0);
2066 lport->tt.frame_send(lport, fp);
2067out:
2068 fc_exch_release(ep);
2069 return;
2070
2071rel:
2072 fc_exch_release(ep);
2073reject:
2074 fc_seq_ls_rjt(rfp, reason, explan);
2075}
2076
2077/**
2078 * fc_exch_rrq_resp() - Handler for RRQ responses
2079 * @sp: The sequence that the RRQ is on
2080 * @fp: The RRQ frame
2081 * @arg: The exchange that the RRQ is on
2082 *
2083 * TODO: fix error handler.
2084 */
2085static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
2086{
2087 struct fc_exch *aborted_ep = arg;
2088 unsigned int op;
2089
2090 if (IS_ERR(fp)) {
2091 int err = PTR_ERR(fp);
2092
2093 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
2094 goto cleanup;
2095 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
2096 "frame error %d\n", err);
2097 return;
2098 }
2099
2100 op = fc_frame_payload_op(fp);
2101 fc_frame_free(fp);
2102
2103 switch (op) {
2104 case ELS_LS_RJT:
2105 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ\n");
2106 /* fall through */
2107 case ELS_LS_ACC:
2108 goto cleanup;
2109 default:
2110 FC_EXCH_DBG(aborted_ep, "unexpected response op %x for RRQ\n",
2111 op);
2112 return;
2113 }
2114
2115cleanup:
2116 fc_exch_done(&aborted_ep->seq);
2117 /* drop hold for rec qual */
2118 fc_exch_release(aborted_ep);
2119}
2120
2121
2122/**
2123 * fc_exch_seq_send() - Send a frame using a new exchange and sequence
2124 * @lport: The local port to send the frame on
2125 * @fp: The frame to be sent
2126 * @resp: The response handler for this request
2127 * @destructor: The destructor for the exchange
2128 * @arg: The argument to be passed to the response handler
2129 * @timer_msec: The timeout period for the exchange
2130 *
2131 * The exchange response handler is set in this routine to resp()
2132 * function pointer. It can be called in two scenarios: if a timeout
2133 * occurs or if a response frame is received for the exchange. The
2134 * fc_frame pointer in response handler will also indicate timeout
2135 * as error using IS_ERR related macros.
2136 *
2137 * The exchange destructor handler is also set in this routine.
2138 * The destructor handler is invoked by EM layer when exchange
2139 * is about to free, this can be used by caller to free its
2140 * resources along with exchange free.
2141 *
2142 * The arg is passed back to resp and destructor handler.
2143 *
2144 * The timeout value (in msec) for an exchange is set if non zero
2145 * timer_msec argument is specified. The timer is canceled when
2146 * it fires or when the exchange is done. The exchange timeout handler
2147 * is registered by EM layer.
2148 *
2149 * The frame pointer with some of the header's fields must be
2150 * filled before calling this routine, those fields are:
2151 *
2152 * - routing control
2153 * - FC port did
2154 * - FC port sid
2155 * - FC header type
2156 * - frame control
2157 * - parameter or relative offset
2158 */
2159struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
2160 struct fc_frame *fp,
2161 void (*resp)(struct fc_seq *,
2162 struct fc_frame *fp,
2163 void *arg),
2164 void (*destructor)(struct fc_seq *, void *),
2165 void *arg, u32 timer_msec)
2166{
2167 struct fc_exch *ep;
2168 struct fc_seq *sp = NULL;
2169 struct fc_frame_header *fh;
2170 struct fc_fcp_pkt *fsp = NULL;
2171 int rc = 1;
2172
2173 ep = fc_exch_alloc(lport, fp);
2174 if (!ep) {
2175 fc_frame_free(fp);
2176 return NULL;
2177 }
2178 ep->esb_stat |= ESB_ST_SEQ_INIT;
2179 fh = fc_frame_header_get(fp);
2180 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
2181 ep->resp = resp;
2182 ep->destructor = destructor;
2183 ep->arg = arg;
2184 ep->r_a_tov = lport->r_a_tov;
2185 ep->lp = lport;
2186 sp = &ep->seq;
2187
2188 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
2189 ep->f_ctl = ntoh24(fh->fh_f_ctl);
2190 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
2191 sp->cnt++;
2192
2193 if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD) {
2194 fsp = fr_fsp(fp);
2195 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
2196 }
2197
2198 if (unlikely(lport->tt.frame_send(lport, fp)))
2199 goto err;
2200
2201 if (timer_msec)
2202 fc_exch_timer_set_locked(ep, timer_msec);
2203 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
2204
2205 if (ep->f_ctl & FC_FC_SEQ_INIT)
2206 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
2207 spin_unlock_bh(&ep->ex_lock);
2208 return sp;
2209err:
2210 if (fsp)
2211 fc_fcp_ddp_done(fsp);
2212 rc = fc_exch_done_locked(ep);
2213 spin_unlock_bh(&ep->ex_lock);
2214 if (!rc)
2215 fc_exch_delete(ep);
2216 return NULL;
2217}
2218EXPORT_SYMBOL(fc_exch_seq_send);
2219
2220/**
2221 * fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command
2222 * @ep: The exchange to send the RRQ on
2223 *
2224 * This tells the remote port to stop blocking the use of
2225 * the exchange and the seq_cnt range.
2226 */
2227static void fc_exch_rrq(struct fc_exch *ep)
2228{
2229 struct fc_lport *lport;
2230 struct fc_els_rrq *rrq;
2231 struct fc_frame *fp;
2232 u32 did;
2233
2234 lport = ep->lp;
2235
2236 fp = fc_frame_alloc(lport, sizeof(*rrq));
2237 if (!fp)
2238 goto retry;
2239
2240 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
2241 memset(rrq, 0, sizeof(*rrq));
2242 rrq->rrq_cmd = ELS_RRQ;
2243 hton24(rrq->rrq_s_id, ep->sid);
2244 rrq->rrq_ox_id = htons(ep->oxid);
2245 rrq->rrq_rx_id = htons(ep->rxid);
2246
2247 did = ep->did;
2248 if (ep->esb_stat & ESB_ST_RESP)
2249 did = ep->sid;
2250
2251 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
2252 lport->port_id, FC_TYPE_ELS,
2253 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
2254
2255 if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep,
2256 lport->e_d_tov))
2257 return;
2258
2259retry:
2260 FC_EXCH_DBG(ep, "exch: RRQ send failed\n");
2261 spin_lock_bh(&ep->ex_lock);
2262 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
2263 spin_unlock_bh(&ep->ex_lock);
2264 /* drop hold for rec qual */
2265 fc_exch_release(ep);
2266 return;
2267 }
2268 ep->esb_stat |= ESB_ST_REC_QUAL;
2269 fc_exch_timer_set_locked(ep, ep->r_a_tov);
2270 spin_unlock_bh(&ep->ex_lock);
2271}
2272
2273/**
2274 * fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests
2275 * @fp: The RRQ frame, not freed here.
2276 */
2277static void fc_exch_els_rrq(struct fc_frame *fp)
2278{
2279 struct fc_lport *lport;
2280 struct fc_exch *ep = NULL; /* request or subject exchange */
2281 struct fc_els_rrq *rp;
2282 u32 sid;
2283 u16 xid;
2284 enum fc_els_rjt_explan explan;
2285
2286 lport = fr_dev(fp);
2287 rp = fc_frame_payload_get(fp, sizeof(*rp));
2288 explan = ELS_EXPL_INV_LEN;
2289 if (!rp)
2290 goto reject;
2291
2292 /*
2293 * lookup subject exchange.
2294 */
2295 sid = ntoh24(rp->rrq_s_id); /* subject source */
2296 xid = fc_host_port_id(lport->host) == sid ?
2297 ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
2298 ep = fc_exch_lookup(lport, xid);
2299 explan = ELS_EXPL_OXID_RXID;
2300 if (!ep)
2301 goto reject;
2302 spin_lock_bh(&ep->ex_lock);
2303 FC_EXCH_DBG(ep, "RRQ request from %x: xid %x rxid %x oxid %x\n",
2304 sid, xid, ntohs(rp->rrq_rx_id), ntohs(rp->rrq_ox_id));
2305 if (ep->oxid != ntohs(rp->rrq_ox_id))
2306 goto unlock_reject;
2307 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
2308 ep->rxid != FC_XID_UNKNOWN)
2309 goto unlock_reject;
2310 explan = ELS_EXPL_SID;
2311 if (ep->sid != sid)
2312 goto unlock_reject;
2313
2314 /*
2315 * Clear Recovery Qualifier state, and cancel timer if complete.
2316 */
2317 if (ep->esb_stat & ESB_ST_REC_QUAL) {
2318 ep->esb_stat &= ~ESB_ST_REC_QUAL;
2319 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
2320 }
2321 if (ep->esb_stat & ESB_ST_COMPLETE)
2322 fc_exch_timer_cancel(ep);
2323
2324 spin_unlock_bh(&ep->ex_lock);
2325
2326 /*
2327 * Send LS_ACC.
2328 */
2329 fc_seq_ls_acc(fp);
2330 goto out;
2331
2332unlock_reject:
2333 spin_unlock_bh(&ep->ex_lock);
2334reject:
2335 fc_seq_ls_rjt(fp, ELS_RJT_LOGIC, explan);
2336out:
2337 if (ep)
2338 fc_exch_release(ep); /* drop hold from fc_exch_find */
2339}
2340
2341/**
2342 * fc_exch_update_stats() - update exches stats to lport
2343 * @lport: The local port to update exchange manager stats
2344 */
2345void fc_exch_update_stats(struct fc_lport *lport)
2346{
2347 struct fc_host_statistics *st;
2348 struct fc_exch_mgr_anchor *ema;
2349 struct fc_exch_mgr *mp;
2350
2351 st = &lport->host_stats;
2352
2353 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2354 mp = ema->mp;
2355 st->fc_no_free_exch += atomic_read(&mp->stats.no_free_exch);
2356 st->fc_no_free_exch_xid +=
2357 atomic_read(&mp->stats.no_free_exch_xid);
2358 st->fc_xid_not_found += atomic_read(&mp->stats.xid_not_found);
2359 st->fc_xid_busy += atomic_read(&mp->stats.xid_busy);
2360 st->fc_seq_not_found += atomic_read(&mp->stats.seq_not_found);
2361 st->fc_non_bls_resp += atomic_read(&mp->stats.non_bls_resp);
2362 }
2363}
2364EXPORT_SYMBOL(fc_exch_update_stats);
2365
2366/**
2367 * fc_exch_mgr_add() - Add an exchange manager to a local port's list of EMs
2368 * @lport: The local port to add the exchange manager to
2369 * @mp: The exchange manager to be added to the local port
2370 * @match: The match routine that indicates when this EM should be used
2371 */
2372struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
2373 struct fc_exch_mgr *mp,
2374 bool (*match)(struct fc_frame *))
2375{
2376 struct fc_exch_mgr_anchor *ema;
2377
2378 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
2379 if (!ema)
2380 return ema;
2381
2382 ema->mp = mp;
2383 ema->match = match;
2384 /* add EM anchor to EM anchors list */
2385 list_add_tail(&ema->ema_list, &lport->ema_list);
2386 kref_get(&mp->kref);
2387 return ema;
2388}
2389EXPORT_SYMBOL(fc_exch_mgr_add);
2390
2391/**
2392 * fc_exch_mgr_destroy() - Destroy an exchange manager
2393 * @kref: The reference to the EM to be destroyed
2394 */
2395static void fc_exch_mgr_destroy(struct kref *kref)
2396{
2397 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
2398
2399 mempool_destroy(mp->ep_pool);
2400 free_percpu(mp->pool);
2401 kfree(mp);
2402}
2403
2404/**
2405 * fc_exch_mgr_del() - Delete an EM from a local port's list
2406 * @ema: The exchange manager anchor identifying the EM to be deleted
2407 */
2408void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
2409{
2410 /* remove EM anchor from EM anchors list */
2411 list_del(&ema->ema_list);
2412 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
2413 kfree(ema);
2414}
2415EXPORT_SYMBOL(fc_exch_mgr_del);
2416
2417/**
2418 * fc_exch_mgr_list_clone() - Share all exchange manager objects
2419 * @src: Source lport to clone exchange managers from
2420 * @dst: New lport that takes references to all the exchange managers
2421 */
2422int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)
2423{
2424 struct fc_exch_mgr_anchor *ema, *tmp;
2425
2426 list_for_each_entry(ema, &src->ema_list, ema_list) {
2427 if (!fc_exch_mgr_add(dst, ema->mp, ema->match))
2428 goto err;
2429 }
2430 return 0;
2431err:
2432 list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)
2433 fc_exch_mgr_del(ema);
2434 return -ENOMEM;
2435}
2436EXPORT_SYMBOL(fc_exch_mgr_list_clone);
2437
2438/**
2439 * fc_exch_mgr_alloc() - Allocate an exchange manager
2440 * @lport: The local port that the new EM will be associated with
2441 * @class: The default FC class for new exchanges
2442 * @min_xid: The minimum XID for exchanges from the new EM
2443 * @max_xid: The maximum XID for exchanges from the new EM
2444 * @match: The match routine for the new EM
2445 */
2446struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport,
2447 enum fc_class class,
2448 u16 min_xid, u16 max_xid,
2449 bool (*match)(struct fc_frame *))
2450{
2451 struct fc_exch_mgr *mp;
2452 u16 pool_exch_range;
2453 size_t pool_size;
2454 unsigned int cpu;
2455 struct fc_exch_pool *pool;
2456
2457 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
2458 (min_xid & fc_cpu_mask) != 0) {
2459 FC_LPORT_DBG(lport, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
2460 min_xid, max_xid);
2461 return NULL;
2462 }
2463
2464 /*
2465 * allocate memory for EM
2466 */
2467 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
2468 if (!mp)
2469 return NULL;
2470
2471 mp->class = class;
2472 mp->lport = lport;
2473 /* adjust em exch xid range for offload */
2474 mp->min_xid = min_xid;
2475
2476 /* reduce range so per cpu pool fits into PCPU_MIN_UNIT_SIZE pool */
2477 pool_exch_range = (PCPU_MIN_UNIT_SIZE - sizeof(*pool)) /
2478 sizeof(struct fc_exch *);
2479 if ((max_xid - min_xid + 1) / (fc_cpu_mask + 1) > pool_exch_range) {
2480 mp->max_xid = pool_exch_range * (fc_cpu_mask + 1) +
2481 min_xid - 1;
2482 } else {
2483 mp->max_xid = max_xid;
2484 pool_exch_range = (mp->max_xid - mp->min_xid + 1) /
2485 (fc_cpu_mask + 1);
2486 }
2487
2488 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
2489 if (!mp->ep_pool)
2490 goto free_mp;
2491
2492 /*
2493 * Setup per cpu exch pool with entire exchange id range equally
2494 * divided across all cpus. The exch pointers array memory is
2495 * allocated for exch range per pool.
2496 */
2497 mp->pool_max_index = pool_exch_range - 1;
2498
2499 /*
2500 * Allocate and initialize per cpu exch pool
2501 */
2502 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
2503 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
2504 if (!mp->pool)
2505 goto free_mempool;
2506 for_each_possible_cpu(cpu) {
2507 pool = per_cpu_ptr(mp->pool, cpu);
2508 pool->next_index = 0;
2509 pool->left = FC_XID_UNKNOWN;
2510 pool->right = FC_XID_UNKNOWN;
2511 spin_lock_init(&pool->lock);
2512 INIT_LIST_HEAD(&pool->ex_list);
2513 }
2514
2515 kref_init(&mp->kref);
2516 if (!fc_exch_mgr_add(lport, mp, match)) {
2517 free_percpu(mp->pool);
2518 goto free_mempool;
2519 }
2520
2521 /*
2522 * Above kref_init() sets mp->kref to 1 and then
2523 * call to fc_exch_mgr_add incremented mp->kref again,
2524 * so adjust that extra increment.
2525 */
2526 kref_put(&mp->kref, fc_exch_mgr_destroy);
2527 return mp;
2528
2529free_mempool:
2530 mempool_destroy(mp->ep_pool);
2531free_mp:
2532 kfree(mp);
2533 return NULL;
2534}
2535EXPORT_SYMBOL(fc_exch_mgr_alloc);
2536
2537/**
2538 * fc_exch_mgr_free() - Free all exchange managers on a local port
2539 * @lport: The local port whose EMs are to be freed
2540 */
2541void fc_exch_mgr_free(struct fc_lport *lport)
2542{
2543 struct fc_exch_mgr_anchor *ema, *next;
2544
2545 flush_workqueue(fc_exch_workqueue);
2546 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
2547 fc_exch_mgr_del(ema);
2548}
2549EXPORT_SYMBOL(fc_exch_mgr_free);
2550
2551/**
2552 * fc_find_ema() - Lookup and return appropriate Exchange Manager Anchor depending
2553 * upon 'xid'.
2554 * @f_ctl: f_ctl
2555 * @lport: The local port the frame was received on
2556 * @fh: The received frame header
2557 */
2558static struct fc_exch_mgr_anchor *fc_find_ema(u32 f_ctl,
2559 struct fc_lport *lport,
2560 struct fc_frame_header *fh)
2561{
2562 struct fc_exch_mgr_anchor *ema;
2563 u16 xid;
2564
2565 if (f_ctl & FC_FC_EX_CTX)
2566 xid = ntohs(fh->fh_ox_id);
2567 else {
2568 xid = ntohs(fh->fh_rx_id);
2569 if (xid == FC_XID_UNKNOWN)
2570 return list_entry(lport->ema_list.prev,
2571 typeof(*ema), ema_list);
2572 }
2573
2574 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2575 if ((xid >= ema->mp->min_xid) &&
2576 (xid <= ema->mp->max_xid))
2577 return ema;
2578 }
2579 return NULL;
2580}
2581/**
2582 * fc_exch_recv() - Handler for received frames
2583 * @lport: The local port the frame was received on
2584 * @fp: The received frame
2585 */
2586void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)
2587{
2588 struct fc_frame_header *fh = fc_frame_header_get(fp);
2589 struct fc_exch_mgr_anchor *ema;
2590 u32 f_ctl;
2591
2592 /* lport lock ? */
2593 if (!lport || lport->state == LPORT_ST_DISABLED) {
2594 FC_LIBFC_DBG("Receiving frames for an lport that "
2595 "has not been initialized correctly\n");
2596 fc_frame_free(fp);
2597 return;
2598 }
2599
2600 f_ctl = ntoh24(fh->fh_f_ctl);
2601 ema = fc_find_ema(f_ctl, lport, fh);
2602 if (!ema) {
2603 FC_LPORT_DBG(lport, "Unable to find Exchange Manager Anchor,"
2604 "fc_ctl <0x%x>, xid <0x%x>\n",
2605 f_ctl,
2606 (f_ctl & FC_FC_EX_CTX) ?
2607 ntohs(fh->fh_ox_id) :
2608 ntohs(fh->fh_rx_id));
2609 fc_frame_free(fp);
2610 return;
2611 }
2612
2613 /*
2614 * If frame is marked invalid, just drop it.
2615 */
2616 switch (fr_eof(fp)) {
2617 case FC_EOF_T:
2618 if (f_ctl & FC_FC_END_SEQ)
2619 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2620 /* fall through */
2621 case FC_EOF_N:
2622 if (fh->fh_type == FC_TYPE_BLS)
2623 fc_exch_recv_bls(ema->mp, fp);
2624 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2625 FC_FC_EX_CTX)
2626 fc_exch_recv_seq_resp(ema->mp, fp);
2627 else if (f_ctl & FC_FC_SEQ_CTX)
2628 fc_exch_recv_resp(ema->mp, fp);
2629 else /* no EX_CTX and no SEQ_CTX */
2630 fc_exch_recv_req(lport, ema->mp, fp);
2631 break;
2632 default:
2633 FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)",
2634 fr_eof(fp));
2635 fc_frame_free(fp);
2636 }
2637}
2638EXPORT_SYMBOL(fc_exch_recv);
2639
2640/**
2641 * fc_exch_init() - Initialize the exchange layer for a local port
2642 * @lport: The local port to initialize the exchange layer for
2643 */
2644int fc_exch_init(struct fc_lport *lport)
2645{
2646 if (!lport->tt.exch_mgr_reset)
2647 lport->tt.exch_mgr_reset = fc_exch_mgr_reset;
2648
2649 return 0;
2650}
2651EXPORT_SYMBOL(fc_exch_init);
2652
2653/**
2654 * fc_setup_exch_mgr() - Setup an exchange manager
2655 */
2656int fc_setup_exch_mgr(void)
2657{
2658 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2659 0, SLAB_HWCACHE_ALIGN, NULL);
2660 if (!fc_em_cachep)
2661 return -ENOMEM;
2662
2663 /*
2664 * Initialize fc_cpu_mask and fc_cpu_order. The
2665 * fc_cpu_mask is set for nr_cpu_ids rounded up
2666 * to order of 2's * power and order is stored
2667 * in fc_cpu_order as this is later required in
2668 * mapping between an exch id and exch array index
2669 * in per cpu exch pool.
2670 *
2671 * This round up is required to align fc_cpu_mask
2672 * to exchange id's lower bits such that all incoming
2673 * frames of an exchange gets delivered to the same
2674 * cpu on which exchange originated by simple bitwise
2675 * AND operation between fc_cpu_mask and exchange id.
2676 */
2677 fc_cpu_order = ilog2(roundup_pow_of_two(nr_cpu_ids));
2678 fc_cpu_mask = (1 << fc_cpu_order) - 1;
2679
2680 fc_exch_workqueue = create_singlethread_workqueue("fc_exch_workqueue");
2681 if (!fc_exch_workqueue)
2682 goto err;
2683 return 0;
2684err:
2685 kmem_cache_destroy(fc_em_cachep);
2686 return -ENOMEM;
2687}
2688
2689/**
2690 * fc_destroy_exch_mgr() - Destroy an exchange manager
2691 */
2692void fc_destroy_exch_mgr(void)
2693{
2694 destroy_workqueue(fc_exch_workqueue);
2695 kmem_cache_destroy(fc_em_cachep);
2696}