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
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.
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
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.
19 * Maintained at www.Open-FCoE.org
23 * Fibre Channel exchange and sequence handling.
26 #include <linux/timer.h>
27 #include <linux/gfp.h>
28 #include <linux/err.h>
30 #include <scsi/fc/fc_fc2.h>
32 #include <scsi/libfc.h>
33 #include <scsi/fc_encode.h>
35 u16 fc_cpu_mask; /* cpu mask for possible cpus */
36 EXPORT_SYMBOL(fc_cpu_mask);
37 static u16 fc_cpu_order; /* 2's power to represent total possible cpus */
38 static struct kmem_cache *fc_em_cachep; /* cache for exchanges */
41 * Structure and function definitions for managing Fibre Channel Exchanges
44 * The three primary structures used here are fc_exch_mgr, fc_exch, and fc_seq.
46 * fc_exch_mgr holds the exchange state for an N port
48 * fc_exch holds state for one exchange and links to its active sequence.
50 * fc_seq holds the state for an individual sequence.
54 * Per cpu exchange pool
56 * This structure manages per cpu exchanges in array of exchange pointers.
57 * This array is allocated followed by struct fc_exch_pool memory for
58 * assigned range of exchanges to per cpu pool.
61 u16 next_index; /* next possible free exchange index */
62 u16 total_exches; /* total allocated exchanges */
63 spinlock_t lock; /* exch pool lock */
64 struct list_head ex_list; /* allocated exchanges list */
70 * This structure is the center for creating exchanges and sequences.
71 * It manages the allocation of exchange IDs.
74 enum fc_class class; /* default class for sequences */
75 struct kref kref; /* exchange mgr reference count */
76 u16 min_xid; /* min exchange ID */
77 u16 max_xid; /* max exchange ID */
78 mempool_t *ep_pool; /* reserve ep's */
79 u16 pool_max_index; /* max exch array index in exch pool */
80 struct fc_exch_pool *pool; /* per cpu exch pool */
83 * currently exchange mgr stats are updated but not used.
84 * either stats can be expose via sysfs or remove them
85 * all together if not used XXX
88 atomic_t no_free_exch;
89 atomic_t no_free_exch_xid;
90 atomic_t xid_not_found;
92 atomic_t seq_not_found;
93 atomic_t non_bls_resp;
96 #define fc_seq_exch(sp) container_of(sp, struct fc_exch, seq)
98 struct fc_exch_mgr_anchor {
99 struct list_head ema_list;
100 struct fc_exch_mgr *mp;
101 bool (*match)(struct fc_frame *);
104 static void fc_exch_rrq(struct fc_exch *);
105 static void fc_seq_ls_acc(struct fc_seq *);
106 static void fc_seq_ls_rjt(struct fc_seq *, enum fc_els_rjt_reason,
107 enum fc_els_rjt_explan);
108 static void fc_exch_els_rec(struct fc_seq *, struct fc_frame *);
109 static void fc_exch_els_rrq(struct fc_seq *, struct fc_frame *);
112 * Internal implementation notes.
114 * The exchange manager is one by default in libfc but LLD may choose
115 * to have one per CPU. The sequence manager is one per exchange manager
116 * and currently never separated.
118 * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field
119 * assigned by the Sequence Initiator that shall be unique for a specific
120 * D_ID and S_ID pair while the Sequence is open." Note that it isn't
121 * qualified by exchange ID, which one might think it would be.
122 * In practice this limits the number of open sequences and exchanges to 256
123 * per session. For most targets we could treat this limit as per exchange.
125 * The exchange and its sequence are freed when the last sequence is received.
126 * It's possible for the remote port to leave an exchange open without
127 * sending any sequences.
129 * Notes on reference counts:
131 * Exchanges are reference counted and exchange gets freed when the reference
132 * count becomes zero.
135 * Sequences are timed out for E_D_TOV and R_A_TOV.
137 * Sequence event handling:
139 * The following events may occur on initiator sequences:
142 * For now, the whole thing is sent.
144 * This applies only to class F.
145 * The sequence is marked complete.
147 * The upper layer calls fc_exch_done() when done
148 * with exchange and sequence tuple.
149 * RX-inferred completion.
150 * When we receive the next sequence on the same exchange, we can
151 * retire the previous sequence ID. (XXX not implemented).
153 * R_A_TOV frees the sequence ID. If we're waiting for ACK,
154 * E_D_TOV causes abort and calls upper layer response handler
155 * with FC_EX_TIMEOUT error.
161 * The following events may occur on recipient sequences:
164 * Allocate sequence for first frame received.
165 * Hold during receive handler.
166 * Release when final frame received.
167 * Keep status of last N of these for the ELS RES command. XXX TBD.
169 * Deallocate sequence
173 * For now, we neglect conditions where only part of a sequence was
174 * received or transmitted, or where out-of-order receipt is detected.
180 * The EM code run in a per-CPU worker thread.
182 * To protect against concurrency between a worker thread code and timers,
183 * sequence allocation and deallocation must be locked.
184 * - exchange refcnt can be done atomicly without locks.
185 * - sequence allocation must be locked by exch lock.
186 * - If the EM pool lock and ex_lock must be taken at the same time, then the
187 * EM pool lock must be taken before the ex_lock.
191 * opcode names for debugging.
193 static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;
195 #define FC_TABLE_SIZE(x) (sizeof(x) / sizeof(x[0]))
197 static inline const char *fc_exch_name_lookup(unsigned int op, char **table,
198 unsigned int max_index)
200 const char *name = NULL;
209 static const char *fc_exch_rctl_name(unsigned int op)
211 return fc_exch_name_lookup(op, fc_exch_rctl_names,
212 FC_TABLE_SIZE(fc_exch_rctl_names));
216 * Hold an exchange - keep it from being freed.
218 static void fc_exch_hold(struct fc_exch *ep)
220 atomic_inc(&ep->ex_refcnt);
224 * setup fc hdr by initializing few more FC header fields and sof/eof.
225 * Initialized fields by this func:
226 * - fh_ox_id, fh_rx_id, fh_seq_id, fh_seq_cnt
229 static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,
232 struct fc_frame_header *fh = fc_frame_header_get(fp);
235 fr_sof(fp) = ep->class;
237 fr_sof(fp) = fc_sof_normal(ep->class);
239 if (f_ctl & FC_FC_END_SEQ) {
240 fr_eof(fp) = FC_EOF_T;
241 if (fc_sof_needs_ack(ep->class))
242 fr_eof(fp) = FC_EOF_N;
245 * The number of fill bytes to make the length a 4-byte
246 * multiple is the low order 2-bits of the f_ctl.
247 * The fill itself will have been cleared by the frame
249 * After this, the length will be even, as expected by
252 fill = fr_len(fp) & 3;
255 /* TODO, this may be a problem with fragmented skb */
256 skb_put(fp_skb(fp), fill);
257 hton24(fh->fh_f_ctl, f_ctl | fill);
260 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
261 fr_eof(fp) = FC_EOF_N;
265 * Initialize remainig fh fields
266 * from fc_fill_fc_hdr
268 fh->fh_ox_id = htons(ep->oxid);
269 fh->fh_rx_id = htons(ep->rxid);
270 fh->fh_seq_id = ep->seq.id;
271 fh->fh_seq_cnt = htons(ep->seq.cnt);
275 * Release a reference to an exchange.
276 * If the refcnt goes to zero and the exchange is complete, it is freed.
278 static void fc_exch_release(struct fc_exch *ep)
280 struct fc_exch_mgr *mp;
282 if (atomic_dec_and_test(&ep->ex_refcnt)) {
285 ep->destructor(&ep->seq, ep->arg);
286 WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));
287 mempool_free(ep, mp->ep_pool);
291 static int fc_exch_done_locked(struct fc_exch *ep)
296 * We must check for completion in case there are two threads
297 * tyring to complete this. But the rrq code will reuse the
298 * ep, and in that case we only clear the resp and set it as
299 * complete, so it can be reused by the timer to send the rrq.
302 if (ep->state & FC_EX_DONE)
304 ep->esb_stat |= ESB_ST_COMPLETE;
306 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
307 ep->state |= FC_EX_DONE;
308 if (cancel_delayed_work(&ep->timeout_work))
309 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
315 static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,
318 struct fc_exch **exches = (struct fc_exch **)(pool + 1);
319 return exches[index];
322 static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
325 ((struct fc_exch **)(pool + 1))[index] = ep;
328 static void fc_exch_delete(struct fc_exch *ep)
330 struct fc_exch_pool *pool;
333 spin_lock_bh(&pool->lock);
334 WARN_ON(pool->total_exches <= 0);
335 pool->total_exches--;
336 fc_exch_ptr_set(pool, (ep->xid - ep->em->min_xid) >> fc_cpu_order,
338 list_del(&ep->ex_list);
339 spin_unlock_bh(&pool->lock);
340 fc_exch_release(ep); /* drop hold for exch in mp */
344 * Internal version of fc_exch_timer_set - used with lock held.
346 static inline void fc_exch_timer_set_locked(struct fc_exch *ep,
347 unsigned int timer_msec)
349 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
352 FC_EXCH_DBG(ep, "Exchange timer armed\n");
354 if (schedule_delayed_work(&ep->timeout_work,
355 msecs_to_jiffies(timer_msec)))
356 fc_exch_hold(ep); /* hold for timer */
360 * Set timer for an exchange.
361 * The time is a minimum delay in milliseconds until the timer fires.
362 * Used for upper level protocols to time out the exchange.
363 * The timer is cancelled when it fires or when the exchange completes.
364 * Returns non-zero if a timer couldn't be allocated.
366 static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec)
368 spin_lock_bh(&ep->ex_lock);
369 fc_exch_timer_set_locked(ep, timer_msec);
370 spin_unlock_bh(&ep->ex_lock);
374 * send a frame using existing sequence and exchange.
376 static int fc_seq_send(struct fc_lport *lp, struct fc_seq *sp,
380 struct fc_frame_header *fh = fc_frame_header_get(fp);
384 ep = fc_seq_exch(sp);
385 WARN_ON((ep->esb_stat & ESB_ST_SEQ_INIT) != ESB_ST_SEQ_INIT);
387 f_ctl = ntoh24(fh->fh_f_ctl);
388 fc_exch_setup_hdr(ep, fp, f_ctl);
391 * update sequence count if this frame is carrying
392 * multiple FC frames when sequence offload is enabled
395 if (fr_max_payload(fp))
396 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),
404 error = lp->tt.frame_send(lp, fp);
407 * Update the exchange and sequence flags,
408 * assuming all frames for the sequence have been sent.
409 * We can only be called to send once for each sequence.
411 spin_lock_bh(&ep->ex_lock);
412 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
413 if (f_ctl & (FC_FC_END_SEQ | FC_FC_SEQ_INIT))
414 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
415 spin_unlock_bh(&ep->ex_lock);
420 * fc_seq_alloc() - Allocate a sequence.
421 * @ep: Exchange pointer
422 * @seq_id: Sequence ID to allocate a sequence for
424 * We don't support multiple originated sequences on the same exchange.
425 * By implication, any previously originated sequence on this exchange
426 * is complete, and we reallocate the same sequence.
428 static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
439 static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
441 struct fc_exch *ep = fc_seq_exch(sp);
443 sp = fc_seq_alloc(ep, ep->seq_id++);
444 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
450 * Allocate a new sequence on the same exchange as the supplied sequence.
451 * This will never return NULL.
453 static struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
455 struct fc_exch *ep = fc_seq_exch(sp);
457 spin_lock_bh(&ep->ex_lock);
458 sp = fc_seq_start_next_locked(sp);
459 spin_unlock_bh(&ep->ex_lock);
465 * This function is for seq_exch_abort function pointer in
466 * struct libfc_function_template, see comment block on
467 * seq_exch_abort for description of this function.
469 static int fc_seq_exch_abort(const struct fc_seq *req_sp,
470 unsigned int timer_msec)
477 ep = fc_seq_exch(req_sp);
479 spin_lock_bh(&ep->ex_lock);
480 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
481 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
482 spin_unlock_bh(&ep->ex_lock);
487 * Send the abort on a new sequence if possible.
489 sp = fc_seq_start_next_locked(&ep->seq);
491 spin_unlock_bh(&ep->ex_lock);
495 ep->esb_stat |= ESB_ST_SEQ_INIT | ESB_ST_ABNORMAL;
497 fc_exch_timer_set_locked(ep, timer_msec);
498 spin_unlock_bh(&ep->ex_lock);
501 * If not logged into the fabric, don't send ABTS but leave
502 * sequence active until next timeout.
508 * Send an abort for the sequence that timed out.
510 fp = fc_frame_alloc(ep->lp, 0);
512 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
513 FC_TYPE_BLS, FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
514 error = fc_seq_send(ep->lp, sp, fp);
521 * Exchange timeout - handle exchange timer expiration.
522 * The timer will have been cancelled before this is called.
524 static void fc_exch_timeout(struct work_struct *work)
526 struct fc_exch *ep = container_of(work, struct fc_exch,
528 struct fc_seq *sp = &ep->seq;
529 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
534 FC_EXCH_DBG(ep, "Exchange timed out\n");
536 spin_lock_bh(&ep->ex_lock);
537 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
540 e_stat = ep->esb_stat;
541 if (e_stat & ESB_ST_COMPLETE) {
542 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
543 spin_unlock_bh(&ep->ex_lock);
544 if (e_stat & ESB_ST_REC_QUAL)
551 if (e_stat & ESB_ST_ABNORMAL)
552 rc = fc_exch_done_locked(ep);
553 spin_unlock_bh(&ep->ex_lock);
557 resp(sp, ERR_PTR(-FC_EX_TIMEOUT), arg);
558 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
562 spin_unlock_bh(&ep->ex_lock);
565 * This release matches the hold taken when the timer was set.
571 * fc_exch_em_alloc() - allocate an exchange from a specified EM.
572 * @lport: ptr to the local port
573 * @mp: ptr to the exchange manager
575 * Returns pointer to allocated fc_exch with exch lock held.
577 static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
578 struct fc_exch_mgr *mp)
583 struct fc_exch_pool *pool;
585 /* allocate memory for exchange */
586 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);
588 atomic_inc(&mp->stats.no_free_exch);
591 memset(ep, 0, sizeof(*ep));
593 cpu = smp_processor_id();
594 pool = per_cpu_ptr(mp->pool, cpu);
595 spin_lock_bh(&pool->lock);
596 index = pool->next_index;
597 /* allocate new exch from pool */
598 while (fc_exch_ptr_get(pool, index)) {
599 index = index == mp->pool_max_index ? 0 : index + 1;
600 if (index == pool->next_index)
603 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
605 fc_exch_hold(ep); /* hold for exch in mp */
606 spin_lock_init(&ep->ex_lock);
608 * Hold exch lock for caller to prevent fc_exch_reset()
609 * from releasing exch while fc_exch_alloc() caller is
610 * still working on exch.
612 spin_lock_bh(&ep->ex_lock);
614 fc_exch_ptr_set(pool, index, ep);
615 list_add_tail(&ep->ex_list, &pool->ex_list);
616 fc_seq_alloc(ep, ep->seq_id++);
617 pool->total_exches++;
618 spin_unlock_bh(&pool->lock);
623 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
627 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
628 ep->rxid = FC_XID_UNKNOWN;
629 ep->class = mp->class;
630 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
634 spin_unlock_bh(&pool->lock);
635 atomic_inc(&mp->stats.no_free_exch_xid);
636 mempool_free(ep, mp->ep_pool);
641 * fc_exch_alloc() - allocate an exchange.
642 * @lport: ptr to the local port
643 * @fp: ptr to the FC frame
645 * This function walks the list of the exchange manager(EM)
646 * anchors to select a EM for new exchange allocation. The
647 * EM is selected having either a NULL match function pointer
648 * or call to match function returning true.
650 static struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
653 struct fc_exch_mgr_anchor *ema;
656 list_for_each_entry(ema, &lport->ema_list, ema_list) {
657 if (!ema->match || ema->match(fp)) {
658 ep = fc_exch_em_alloc(lport, ema->mp);
667 * Lookup and hold an exchange.
669 static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
671 struct fc_exch_pool *pool;
672 struct fc_exch *ep = NULL;
674 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
675 pool = per_cpu_ptr(mp->pool, xid & fc_cpu_mask);
676 spin_lock_bh(&pool->lock);
677 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
680 WARN_ON(ep->xid != xid);
682 spin_unlock_bh(&pool->lock);
689 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and
690 * the memory allocated for the related objects may be freed.
691 * @sp: Sequence pointer
693 static void fc_exch_done(struct fc_seq *sp)
695 struct fc_exch *ep = fc_seq_exch(sp);
698 spin_lock_bh(&ep->ex_lock);
699 rc = fc_exch_done_locked(ep);
700 spin_unlock_bh(&ep->ex_lock);
706 * Allocate a new exchange as responder.
707 * Sets the responder ID in the frame header.
709 static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
710 struct fc_exch_mgr *mp,
714 struct fc_frame_header *fh;
716 ep = fc_exch_alloc(lport, fp);
718 ep->class = fc_frame_class(fp);
721 * Set EX_CTX indicating we're responding on this exchange.
723 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
724 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
725 fh = fc_frame_header_get(fp);
726 ep->sid = ntoh24(fh->fh_d_id);
727 ep->did = ntoh24(fh->fh_s_id);
731 * Allocated exchange has placed the XID in the
732 * originator field. Move it to the responder field,
733 * and set the originator XID from the frame.
736 ep->oxid = ntohs(fh->fh_ox_id);
737 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
738 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
739 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
741 fc_exch_hold(ep); /* hold for caller */
742 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
748 * Find a sequence for receive where the other end is originating the sequence.
749 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
750 * on the ep that should be released by the caller.
752 static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
753 struct fc_exch_mgr *mp,
756 struct fc_frame_header *fh = fc_frame_header_get(fp);
757 struct fc_exch *ep = NULL;
758 struct fc_seq *sp = NULL;
759 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
763 f_ctl = ntoh24(fh->fh_f_ctl);
764 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
767 * Lookup or create the exchange if we will be creating the sequence.
769 if (f_ctl & FC_FC_EX_CTX) {
770 xid = ntohs(fh->fh_ox_id); /* we originated exch */
771 ep = fc_exch_find(mp, xid);
773 atomic_inc(&mp->stats.xid_not_found);
774 reject = FC_RJT_OX_ID;
777 if (ep->rxid == FC_XID_UNKNOWN)
778 ep->rxid = ntohs(fh->fh_rx_id);
779 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
780 reject = FC_RJT_OX_ID;
784 xid = ntohs(fh->fh_rx_id); /* we are the responder */
787 * Special case for MDS issuing an ELS TEST with a
789 * XXX take this out once we do the proper reject.
791 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
792 fc_frame_payload_op(fp) == ELS_TEST) {
793 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
794 xid = FC_XID_UNKNOWN;
798 * new sequence - find the exchange
800 ep = fc_exch_find(mp, xid);
801 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
803 atomic_inc(&mp->stats.xid_busy);
804 reject = FC_RJT_RX_ID;
807 ep = fc_exch_resp(lport, mp, fp);
809 reject = FC_RJT_EXCH_EST; /* XXX */
812 xid = ep->xid; /* get our XID */
814 atomic_inc(&mp->stats.xid_not_found);
815 reject = FC_RJT_RX_ID; /* XID not found */
821 * At this point, we have the exchange held.
822 * Find or create the sequence.
824 if (fc_sof_is_init(fr_sof(fp))) {
825 sp = fc_seq_start_next(&ep->seq);
827 reject = FC_RJT_SEQ_XS; /* exchange shortage */
830 sp->id = fh->fh_seq_id;
831 sp->ssb_stat |= SSB_ST_RESP;
834 if (sp->id != fh->fh_seq_id) {
835 atomic_inc(&mp->stats.seq_not_found);
836 reject = FC_RJT_SEQ_ID; /* sequence/exch should exist */
840 WARN_ON(ep != fc_seq_exch(sp));
842 if (f_ctl & FC_FC_SEQ_INIT)
843 ep->esb_stat |= ESB_ST_SEQ_INIT;
849 fc_exch_done(&ep->seq);
850 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
855 * Find the sequence for a frame being received.
856 * We originated the sequence, so it should be found.
857 * We may or may not have originated the exchange.
858 * Does not hold the sequence for the caller.
860 static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
863 struct fc_frame_header *fh = fc_frame_header_get(fp);
865 struct fc_seq *sp = NULL;
869 f_ctl = ntoh24(fh->fh_f_ctl);
870 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
871 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
872 ep = fc_exch_find(mp, xid);
875 if (ep->seq.id == fh->fh_seq_id) {
877 * Save the RX_ID if we didn't previously know it.
880 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
881 ep->rxid == FC_XID_UNKNOWN) {
882 ep->rxid = ntohs(fh->fh_rx_id);
890 * Set addresses for an exchange.
891 * Note this must be done before the first sequence of the exchange is sent.
893 static void fc_exch_set_addr(struct fc_exch *ep,
894 u32 orig_id, u32 resp_id)
897 if (ep->esb_stat & ESB_ST_RESP) {
907 * fc_seq_els_rsp_send() - Send ELS response using mainly infomation
908 * in exchange and sequence in EM layer.
909 * @sp: Sequence pointer
910 * @els_cmd: ELS command
911 * @els_data: ELS data
913 static void fc_seq_els_rsp_send(struct fc_seq *sp, enum fc_els_cmd els_cmd,
914 struct fc_seq_els_data *els_data)
918 fc_seq_ls_rjt(sp, els_data->reason, els_data->explan);
924 fc_exch_els_rrq(sp, els_data->fp);
927 fc_exch_els_rec(sp, els_data->fp);
930 FC_EXCH_DBG(fc_seq_exch(sp), "Invalid ELS CMD:%x\n", els_cmd);
935 * Send a sequence, which is also the last sequence in the exchange.
937 static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
938 enum fc_rctl rctl, enum fc_fh_type fh_type)
941 struct fc_exch *ep = fc_seq_exch(sp);
943 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
945 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
946 fc_seq_send(ep->lp, sp, fp);
950 * Send ACK_1 (or equiv.) indicating we received something.
951 * The frame we're acking is supplied.
953 static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
956 struct fc_frame_header *rx_fh;
957 struct fc_frame_header *fh;
958 struct fc_exch *ep = fc_seq_exch(sp);
959 struct fc_lport *lp = ep->lp;
963 * Don't send ACKs for class 3.
965 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
966 fp = fc_frame_alloc(lp, 0);
970 fh = fc_frame_header_get(fp);
971 fh->fh_r_ctl = FC_RCTL_ACK_1;
972 fh->fh_type = FC_TYPE_BLS;
975 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
976 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
977 * Bits 9-8 are meaningful (retransmitted or unidirectional).
978 * Last ACK uses bits 7-6 (continue sequence),
979 * bits 5-4 are meaningful (what kind of ACK to use).
981 rx_fh = fc_frame_header_get(rx_fp);
982 f_ctl = ntoh24(rx_fh->fh_f_ctl);
983 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
984 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
985 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
986 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
987 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
988 hton24(fh->fh_f_ctl, f_ctl);
990 fc_exch_setup_hdr(ep, fp, f_ctl);
991 fh->fh_seq_id = rx_fh->fh_seq_id;
992 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
993 fh->fh_parm_offset = htonl(1); /* ack single frame */
995 fr_sof(fp) = fr_sof(rx_fp);
996 if (f_ctl & FC_FC_END_SEQ)
997 fr_eof(fp) = FC_EOF_T;
999 fr_eof(fp) = FC_EOF_N;
1001 (void) lp->tt.frame_send(lp, fp);
1007 * This is for rejecting BA_ABTS only.
1009 static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
1010 enum fc_ba_rjt_reason reason,
1011 enum fc_ba_rjt_explan explan)
1013 struct fc_frame *fp;
1014 struct fc_frame_header *rx_fh;
1015 struct fc_frame_header *fh;
1016 struct fc_ba_rjt *rp;
1017 struct fc_lport *lp;
1021 fp = fc_frame_alloc(lp, sizeof(*rp));
1024 fh = fc_frame_header_get(fp);
1025 rx_fh = fc_frame_header_get(rx_fp);
1027 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1029 rp = fc_frame_payload_get(fp, sizeof(*rp));
1030 rp->br_reason = reason;
1031 rp->br_explan = explan;
1034 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1036 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1037 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1038 fh->fh_ox_id = rx_fh->fh_ox_id;
1039 fh->fh_rx_id = rx_fh->fh_rx_id;
1040 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1041 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1042 fh->fh_type = FC_TYPE_BLS;
1045 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1046 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1047 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1048 * Last ACK uses bits 7-6 (continue sequence),
1049 * bits 5-4 are meaningful (what kind of ACK to use).
1050 * Always set LAST_SEQ, END_SEQ.
1052 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1053 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1054 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1055 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1056 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1057 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1058 f_ctl &= ~FC_FC_FIRST_SEQ;
1059 hton24(fh->fh_f_ctl, f_ctl);
1061 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1062 fr_eof(fp) = FC_EOF_T;
1063 if (fc_sof_needs_ack(fr_sof(fp)))
1064 fr_eof(fp) = FC_EOF_N;
1066 (void) lp->tt.frame_send(lp, fp);
1070 * Handle an incoming ABTS. This would be for target mode usually,
1071 * but could be due to lost FCP transfer ready, confirm or RRQ.
1072 * We always handle this as an exchange abort, ignoring the parameter.
1074 static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1076 struct fc_frame *fp;
1077 struct fc_ba_acc *ap;
1078 struct fc_frame_header *fh;
1083 spin_lock_bh(&ep->ex_lock);
1084 if (ep->esb_stat & ESB_ST_COMPLETE) {
1085 spin_unlock_bh(&ep->ex_lock);
1088 if (!(ep->esb_stat & ESB_ST_REC_QUAL))
1089 fc_exch_hold(ep); /* hold for REC_QUAL */
1090 ep->esb_stat |= ESB_ST_ABNORMAL | ESB_ST_REC_QUAL;
1091 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1093 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1095 spin_unlock_bh(&ep->ex_lock);
1098 fh = fc_frame_header_get(fp);
1099 ap = fc_frame_payload_get(fp, sizeof(*ap));
1100 memset(ap, 0, sizeof(*ap));
1102 ap->ba_high_seq_cnt = htons(0xffff);
1103 if (sp->ssb_stat & SSB_ST_RESP) {
1104 ap->ba_seq_id = sp->id;
1105 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1106 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1107 ap->ba_low_seq_cnt = htons(sp->cnt);
1109 sp = fc_seq_start_next_locked(sp);
1110 spin_unlock_bh(&ep->ex_lock);
1111 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1112 fc_frame_free(rx_fp);
1116 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1118 fc_frame_free(rx_fp);
1122 * Handle receive where the other end is originating the sequence.
1124 static void fc_exch_recv_req(struct fc_lport *lp, struct fc_exch_mgr *mp,
1125 struct fc_frame *fp)
1127 struct fc_frame_header *fh = fc_frame_header_get(fp);
1128 struct fc_seq *sp = NULL;
1129 struct fc_exch *ep = NULL;
1133 enum fc_pf_rjt_reason reject;
1136 reject = fc_seq_lookup_recip(lp, mp, fp);
1137 if (reject == FC_RJT_NONE) {
1138 sp = fr_seq(fp); /* sequence will be held */
1139 ep = fc_seq_exch(sp);
1142 f_ctl = ntoh24(fh->fh_f_ctl);
1143 fc_seq_send_ack(sp, fp);
1146 * Call the receive function.
1148 * The receive function may allocate a new sequence
1149 * over the old one, so we shouldn't change the
1150 * sequence after this.
1152 * The frame will be freed by the receive function.
1153 * If new exch resp handler is valid then call that
1157 ep->resp(sp, fp, ep->arg);
1159 lp->tt.lport_recv(lp, sp, fp);
1160 fc_exch_release(ep); /* release from lookup */
1162 FC_LPORT_DBG(lp, "exch/seq lookup failed: reject %x\n", reject);
1168 * Handle receive where the other end is originating the sequence in
1169 * response to our exchange.
1171 static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1173 struct fc_frame_header *fh = fc_frame_header_get(fp);
1178 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
1182 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1184 atomic_inc(&mp->stats.xid_not_found);
1187 if (ep->esb_stat & ESB_ST_COMPLETE) {
1188 atomic_inc(&mp->stats.xid_not_found);
1191 if (ep->rxid == FC_XID_UNKNOWN)
1192 ep->rxid = ntohs(fh->fh_rx_id);
1193 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1194 atomic_inc(&mp->stats.xid_not_found);
1197 if (ep->did != ntoh24(fh->fh_s_id) &&
1198 ep->did != FC_FID_FLOGI) {
1199 atomic_inc(&mp->stats.xid_not_found);
1203 if (fc_sof_is_init(sof)) {
1204 sp = fc_seq_start_next(&ep->seq);
1205 sp->id = fh->fh_seq_id;
1206 sp->ssb_stat |= SSB_ST_RESP;
1209 if (sp->id != fh->fh_seq_id) {
1210 atomic_inc(&mp->stats.seq_not_found);
1214 f_ctl = ntoh24(fh->fh_f_ctl);
1216 if (f_ctl & FC_FC_SEQ_INIT)
1217 ep->esb_stat |= ESB_ST_SEQ_INIT;
1219 if (fc_sof_needs_ack(sof))
1220 fc_seq_send_ack(sp, fp);
1222 ex_resp_arg = ep->arg;
1224 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1225 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1226 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1227 spin_lock_bh(&ep->ex_lock);
1228 rc = fc_exch_done_locked(ep);
1229 WARN_ON(fc_seq_exch(sp) != ep);
1230 spin_unlock_bh(&ep->ex_lock);
1236 * Call the receive function.
1237 * The sequence is held (has a refcnt) for us,
1238 * but not for the receive function.
1240 * The receive function may allocate a new sequence
1241 * over the old one, so we shouldn't change the
1242 * sequence after this.
1244 * The frame will be freed by the receive function.
1245 * If new exch resp handler is valid then call that
1249 resp(sp, fp, ex_resp_arg);
1252 fc_exch_release(ep);
1255 fc_exch_release(ep);
1261 * Handle receive for a sequence where other end is responding to our sequence.
1263 static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1267 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1270 atomic_inc(&mp->stats.xid_not_found);
1272 atomic_inc(&mp->stats.non_bls_resp);
1278 * Handle the response to an ABTS for exchange or sequence.
1279 * This can be BA_ACC or BA_RJT.
1281 static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1283 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
1285 struct fc_frame_header *fh;
1286 struct fc_ba_acc *ap;
1290 int rc = 1, has_rec = 0;
1292 fh = fc_frame_header_get(fp);
1293 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1294 fc_exch_rctl_name(fh->fh_r_ctl));
1296 if (cancel_delayed_work_sync(&ep->timeout_work))
1297 fc_exch_release(ep); /* release from pending timer hold */
1299 spin_lock_bh(&ep->ex_lock);
1300 switch (fh->fh_r_ctl) {
1301 case FC_RCTL_BA_ACC:
1302 ap = fc_frame_payload_get(fp, sizeof(*ap));
1307 * Decide whether to establish a Recovery Qualifier.
1308 * We do this if there is a non-empty SEQ_CNT range and
1309 * SEQ_ID is the same as the one we aborted.
1311 low = ntohs(ap->ba_low_seq_cnt);
1312 high = ntohs(ap->ba_high_seq_cnt);
1313 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1314 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1315 ap->ba_seq_id == ep->seq_id) && low != high) {
1316 ep->esb_stat |= ESB_ST_REC_QUAL;
1317 fc_exch_hold(ep); /* hold for recovery qualifier */
1321 case FC_RCTL_BA_RJT:
1328 ex_resp_arg = ep->arg;
1330 /* do we need to do some other checks here. Can we reuse more of
1331 * fc_exch_recv_seq_resp
1335 * do we want to check END_SEQ as well as LAST_SEQ here?
1337 if (ep->fh_type != FC_TYPE_FCP &&
1338 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1339 rc = fc_exch_done_locked(ep);
1340 spin_unlock_bh(&ep->ex_lock);
1345 resp(sp, fp, ex_resp_arg);
1350 fc_exch_timer_set(ep, ep->r_a_tov);
1355 * Receive BLS sequence.
1356 * This is always a sequence initiated by the remote side.
1357 * We may be either the originator or recipient of the exchange.
1359 static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1361 struct fc_frame_header *fh;
1365 fh = fc_frame_header_get(fp);
1366 f_ctl = ntoh24(fh->fh_f_ctl);
1369 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1370 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1371 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1372 spin_lock_bh(&ep->ex_lock);
1373 ep->esb_stat |= ESB_ST_SEQ_INIT;
1374 spin_unlock_bh(&ep->ex_lock);
1376 if (f_ctl & FC_FC_SEQ_CTX) {
1378 * A response to a sequence we initiated.
1379 * This should only be ACKs for class 2 or F.
1381 switch (fh->fh_r_ctl) {
1386 FC_EXCH_DBG(ep, "BLS rctl %x - %s received",
1388 fc_exch_rctl_name(fh->fh_r_ctl));
1393 switch (fh->fh_r_ctl) {
1394 case FC_RCTL_BA_RJT:
1395 case FC_RCTL_BA_ACC:
1397 fc_exch_abts_resp(ep, fp);
1401 case FC_RCTL_BA_ABTS:
1402 fc_exch_recv_abts(ep, fp);
1404 default: /* ignore junk */
1410 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1414 * Accept sequence with LS_ACC.
1415 * If this fails due to allocation or transmit congestion, assume the
1416 * originator will repeat the sequence.
1418 static void fc_seq_ls_acc(struct fc_seq *req_sp)
1421 struct fc_els_ls_acc *acc;
1422 struct fc_frame *fp;
1424 sp = fc_seq_start_next(req_sp);
1425 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*acc));
1427 acc = fc_frame_payload_get(fp, sizeof(*acc));
1428 memset(acc, 0, sizeof(*acc));
1429 acc->la_cmd = ELS_LS_ACC;
1430 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1435 * Reject sequence with ELS LS_RJT.
1436 * If this fails due to allocation or transmit congestion, assume the
1437 * originator will repeat the sequence.
1439 static void fc_seq_ls_rjt(struct fc_seq *req_sp, enum fc_els_rjt_reason reason,
1440 enum fc_els_rjt_explan explan)
1443 struct fc_els_ls_rjt *rjt;
1444 struct fc_frame *fp;
1446 sp = fc_seq_start_next(req_sp);
1447 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*rjt));
1449 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1450 memset(rjt, 0, sizeof(*rjt));
1451 rjt->er_cmd = ELS_LS_RJT;
1452 rjt->er_reason = reason;
1453 rjt->er_explan = explan;
1454 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1458 static void fc_exch_reset(struct fc_exch *ep)
1461 void (*resp)(struct fc_seq *, struct fc_frame *, void *);
1465 spin_lock_bh(&ep->ex_lock);
1466 ep->state |= FC_EX_RST_CLEANUP;
1468 * we really want to call del_timer_sync, but cannot due
1469 * to the lport calling with the lport lock held (some resp
1470 * functions can also grab the lport lock which could cause
1473 if (cancel_delayed_work(&ep->timeout_work))
1474 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
1477 if (ep->esb_stat & ESB_ST_REC_QUAL)
1478 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1479 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1482 rc = fc_exch_done_locked(ep);
1483 spin_unlock_bh(&ep->ex_lock);
1488 resp(sp, ERR_PTR(-FC_EX_CLOSED), arg);
1492 * fc_exch_pool_reset() - Resets an per cpu exches pool.
1493 * @lport: ptr to the local port
1494 * @pool: ptr to the per cpu exches pool
1495 * @sid: source FC ID
1496 * @did: destination FC ID
1498 * Resets an per cpu exches pool, releasing its all sequences
1499 * and exchanges. If sid is non-zero, then reset only exchanges
1500 * we sourced from that FID. If did is non-zero, reset only
1501 * exchanges destined to that FID.
1503 static void fc_exch_pool_reset(struct fc_lport *lport,
1504 struct fc_exch_pool *pool,
1508 struct fc_exch *next;
1510 spin_lock_bh(&pool->lock);
1512 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1513 if ((lport == ep->lp) &&
1514 (sid == 0 || sid == ep->sid) &&
1515 (did == 0 || did == ep->did)) {
1517 spin_unlock_bh(&pool->lock);
1521 fc_exch_release(ep);
1522 spin_lock_bh(&pool->lock);
1525 * must restart loop incase while lock
1526 * was down multiple eps were released.
1531 spin_unlock_bh(&pool->lock);
1535 * fc_exch_mgr_reset() - Resets all EMs of a lport
1536 * @lport: ptr to the local port
1537 * @sid: source FC ID
1538 * @did: destination FC ID
1540 * Reset all EMs of a lport, releasing its all sequences and
1541 * exchanges. If sid is non-zero, then reset only exchanges
1542 * we sourced from that FID. If did is non-zero, reset only
1543 * exchanges destined to that FID.
1545 void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1547 struct fc_exch_mgr_anchor *ema;
1550 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1551 for_each_possible_cpu(cpu)
1552 fc_exch_pool_reset(lport,
1553 per_cpu_ptr(ema->mp->pool, cpu),
1557 EXPORT_SYMBOL(fc_exch_mgr_reset);
1560 * Handle incoming ELS REC - Read Exchange Concise.
1561 * Note that the requesting port may be different than the S_ID in the request.
1563 static void fc_exch_els_rec(struct fc_seq *sp, struct fc_frame *rfp)
1565 struct fc_frame *fp;
1567 struct fc_exch_mgr *em;
1568 struct fc_els_rec *rp;
1569 struct fc_els_rec_acc *acc;
1570 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
1571 enum fc_els_rjt_explan explan;
1576 rp = fc_frame_payload_get(rfp, sizeof(*rp));
1577 explan = ELS_EXPL_INV_LEN;
1580 sid = ntoh24(rp->rec_s_id);
1581 rxid = ntohs(rp->rec_rx_id);
1582 oxid = ntohs(rp->rec_ox_id);
1585 * Currently it's hard to find the local S_ID from the exchange
1586 * manager. This will eventually be fixed, but for now it's easier
1587 * to lookup the subject exchange twice, once as if we were
1588 * the initiator, and then again if we weren't.
1590 em = fc_seq_exch(sp)->em;
1591 ep = fc_exch_find(em, oxid);
1592 explan = ELS_EXPL_OXID_RXID;
1593 if (ep && ep->oid == sid) {
1594 if (ep->rxid != FC_XID_UNKNOWN &&
1595 rxid != FC_XID_UNKNOWN &&
1600 fc_exch_release(ep);
1602 if (rxid != FC_XID_UNKNOWN)
1603 ep = fc_exch_find(em, rxid);
1608 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*acc));
1613 sp = fc_seq_start_next(sp);
1614 acc = fc_frame_payload_get(fp, sizeof(*acc));
1615 memset(acc, 0, sizeof(*acc));
1616 acc->reca_cmd = ELS_LS_ACC;
1617 acc->reca_ox_id = rp->rec_ox_id;
1618 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
1619 acc->reca_rx_id = htons(ep->rxid);
1620 if (ep->sid == ep->oid)
1621 hton24(acc->reca_rfid, ep->did);
1623 hton24(acc->reca_rfid, ep->sid);
1624 acc->reca_fc4value = htonl(ep->seq.rec_data);
1625 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
1628 sp = fc_seq_start_next(sp);
1629 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1631 fc_exch_release(ep);
1636 fc_exch_release(ep);
1638 fc_seq_ls_rjt(sp, reason, explan);
1643 * Handle response from RRQ.
1644 * Not much to do here, really.
1645 * Should report errors.
1647 * TODO: fix error handler.
1649 static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
1651 struct fc_exch *aborted_ep = arg;
1655 int err = PTR_ERR(fp);
1657 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
1659 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
1660 "frame error %d\n", err);
1664 op = fc_frame_payload_op(fp);
1669 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ");
1674 FC_EXCH_DBG(aborted_ep, "unexpected response op %x "
1680 fc_exch_done(&aborted_ep->seq);
1681 /* drop hold for rec qual */
1682 fc_exch_release(aborted_ep);
1687 * This function is for exch_seq_send function pointer in
1688 * struct libfc_function_template, see comment block on
1689 * exch_seq_send for description of this function.
1691 static struct fc_seq *fc_exch_seq_send(struct fc_lport *lp,
1692 struct fc_frame *fp,
1693 void (*resp)(struct fc_seq *,
1694 struct fc_frame *fp,
1696 void (*destructor)(struct fc_seq *,
1698 void *arg, u32 timer_msec)
1701 struct fc_seq *sp = NULL;
1702 struct fc_frame_header *fh;
1705 ep = fc_exch_alloc(lp, fp);
1710 ep->esb_stat |= ESB_ST_SEQ_INIT;
1711 fh = fc_frame_header_get(fp);
1712 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
1714 ep->destructor = destructor;
1716 ep->r_a_tov = FC_DEF_R_A_TOV;
1720 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
1721 ep->f_ctl = ntoh24(fh->fh_f_ctl);
1722 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
1725 if (ep->xid <= lp->lro_xid)
1726 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
1728 if (unlikely(lp->tt.frame_send(lp, fp)))
1732 fc_exch_timer_set_locked(ep, timer_msec);
1733 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
1735 if (ep->f_ctl & FC_FC_SEQ_INIT)
1736 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
1737 spin_unlock_bh(&ep->ex_lock);
1740 rc = fc_exch_done_locked(ep);
1741 spin_unlock_bh(&ep->ex_lock);
1748 * Send ELS RRQ - Reinstate Recovery Qualifier.
1749 * This tells the remote port to stop blocking the use of
1750 * the exchange and the seq_cnt range.
1752 static void fc_exch_rrq(struct fc_exch *ep)
1754 struct fc_lport *lp;
1755 struct fc_els_rrq *rrq;
1756 struct fc_frame *fp;
1761 fp = fc_frame_alloc(lp, sizeof(*rrq));
1765 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
1766 memset(rrq, 0, sizeof(*rrq));
1767 rrq->rrq_cmd = ELS_RRQ;
1768 hton24(rrq->rrq_s_id, ep->sid);
1769 rrq->rrq_ox_id = htons(ep->oxid);
1770 rrq->rrq_rx_id = htons(ep->rxid);
1773 if (ep->esb_stat & ESB_ST_RESP)
1776 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
1777 fc_host_port_id(lp->host), FC_TYPE_ELS,
1778 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1780 if (fc_exch_seq_send(lp, fp, fc_exch_rrq_resp, NULL, ep, lp->e_d_tov))
1784 spin_lock_bh(&ep->ex_lock);
1785 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
1786 spin_unlock_bh(&ep->ex_lock);
1787 /* drop hold for rec qual */
1788 fc_exch_release(ep);
1791 ep->esb_stat |= ESB_ST_REC_QUAL;
1792 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1793 spin_unlock_bh(&ep->ex_lock);
1798 * Handle incoming ELS RRQ - Reset Recovery Qualifier.
1800 static void fc_exch_els_rrq(struct fc_seq *sp, struct fc_frame *fp)
1802 struct fc_exch *ep = NULL; /* request or subject exchange */
1803 struct fc_els_rrq *rp;
1806 enum fc_els_rjt_explan explan;
1808 rp = fc_frame_payload_get(fp, sizeof(*rp));
1809 explan = ELS_EXPL_INV_LEN;
1814 * lookup subject exchange.
1816 ep = fc_seq_exch(sp);
1817 sid = ntoh24(rp->rrq_s_id); /* subject source */
1818 xid = ep->did == sid ? ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
1819 ep = fc_exch_find(ep->em, xid);
1821 explan = ELS_EXPL_OXID_RXID;
1824 spin_lock_bh(&ep->ex_lock);
1825 if (ep->oxid != ntohs(rp->rrq_ox_id))
1827 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
1828 ep->rxid != FC_XID_UNKNOWN)
1830 explan = ELS_EXPL_SID;
1835 * Clear Recovery Qualifier state, and cancel timer if complete.
1837 if (ep->esb_stat & ESB_ST_REC_QUAL) {
1838 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1839 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
1841 if (ep->esb_stat & ESB_ST_COMPLETE) {
1842 if (cancel_delayed_work(&ep->timeout_work))
1843 atomic_dec(&ep->ex_refcnt); /* drop timer hold */
1846 spin_unlock_bh(&ep->ex_lock);
1855 spin_unlock_bh(&ep->ex_lock);
1857 fc_seq_ls_rjt(sp, ELS_RJT_LOGIC, explan);
1861 fc_exch_release(ep); /* drop hold from fc_exch_find */
1864 struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
1865 struct fc_exch_mgr *mp,
1866 bool (*match)(struct fc_frame *))
1868 struct fc_exch_mgr_anchor *ema;
1870 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
1876 /* add EM anchor to EM anchors list */
1877 list_add_tail(&ema->ema_list, &lport->ema_list);
1878 kref_get(&mp->kref);
1881 EXPORT_SYMBOL(fc_exch_mgr_add);
1883 static void fc_exch_mgr_destroy(struct kref *kref)
1885 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
1887 mempool_destroy(mp->ep_pool);
1888 free_percpu(mp->pool);
1892 void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
1894 /* remove EM anchor from EM anchors list */
1895 list_del(&ema->ema_list);
1896 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
1899 EXPORT_SYMBOL(fc_exch_mgr_del);
1901 struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lp,
1902 enum fc_class class,
1903 u16 min_xid, u16 max_xid,
1904 bool (*match)(struct fc_frame *))
1906 struct fc_exch_mgr *mp;
1907 u16 pool_exch_range;
1910 struct fc_exch_pool *pool;
1912 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
1913 (min_xid & fc_cpu_mask) != 0) {
1914 FC_LPORT_DBG(lp, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
1920 * allocate memory for EM
1922 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
1927 /* adjust em exch xid range for offload */
1928 mp->min_xid = min_xid;
1929 mp->max_xid = max_xid;
1931 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
1936 * Setup per cpu exch pool with entire exchange id range equally
1937 * divided across all cpus. The exch pointers array memory is
1938 * allocated for exch range per pool.
1940 pool_exch_range = (mp->max_xid - mp->min_xid + 1) / (fc_cpu_mask + 1);
1941 mp->pool_max_index = pool_exch_range - 1;
1944 * Allocate and initialize per cpu exch pool
1946 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
1947 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
1950 for_each_possible_cpu(cpu) {
1951 pool = per_cpu_ptr(mp->pool, cpu);
1952 spin_lock_init(&pool->lock);
1953 INIT_LIST_HEAD(&pool->ex_list);
1956 kref_init(&mp->kref);
1957 if (!fc_exch_mgr_add(lp, mp, match)) {
1958 free_percpu(mp->pool);
1963 * Above kref_init() sets mp->kref to 1 and then
1964 * call to fc_exch_mgr_add incremented mp->kref again,
1965 * so adjust that extra increment.
1967 kref_put(&mp->kref, fc_exch_mgr_destroy);
1971 mempool_destroy(mp->ep_pool);
1976 EXPORT_SYMBOL(fc_exch_mgr_alloc);
1978 void fc_exch_mgr_free(struct fc_lport *lport)
1980 struct fc_exch_mgr_anchor *ema, *next;
1982 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
1983 fc_exch_mgr_del(ema);
1985 EXPORT_SYMBOL(fc_exch_mgr_free);
1990 void fc_exch_recv(struct fc_lport *lp, struct fc_frame *fp)
1992 struct fc_frame_header *fh = fc_frame_header_get(fp);
1993 struct fc_exch_mgr_anchor *ema;
1994 u32 f_ctl, found = 0;
1998 if (!lp || lp->state == LPORT_ST_DISABLED) {
1999 FC_LPORT_DBG(lp, "Receiving frames for an lport that "
2000 "has not been initialized correctly\n");
2005 f_ctl = ntoh24(fh->fh_f_ctl);
2006 oxid = ntohs(fh->fh_ox_id);
2007 if (f_ctl & FC_FC_EX_CTX) {
2008 list_for_each_entry(ema, &lp->ema_list, ema_list) {
2009 if ((oxid >= ema->mp->min_xid) &&
2010 (oxid <= ema->mp->max_xid)) {
2017 FC_LPORT_DBG(lp, "Received response for out "
2018 "of range oxid:%hx\n", oxid);
2023 ema = list_entry(lp->ema_list.prev, typeof(*ema), ema_list);
2026 * If frame is marked invalid, just drop it.
2028 switch (fr_eof(fp)) {
2030 if (f_ctl & FC_FC_END_SEQ)
2031 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2034 if (fh->fh_type == FC_TYPE_BLS)
2035 fc_exch_recv_bls(ema->mp, fp);
2036 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2038 fc_exch_recv_seq_resp(ema->mp, fp);
2039 else if (f_ctl & FC_FC_SEQ_CTX)
2040 fc_exch_recv_resp(ema->mp, fp);
2042 fc_exch_recv_req(lp, ema->mp, fp);
2045 FC_LPORT_DBG(lp, "dropping invalid frame (eof %x)", fr_eof(fp));
2049 EXPORT_SYMBOL(fc_exch_recv);
2051 int fc_exch_init(struct fc_lport *lp)
2053 if (!lp->tt.seq_start_next)
2054 lp->tt.seq_start_next = fc_seq_start_next;
2056 if (!lp->tt.exch_seq_send)
2057 lp->tt.exch_seq_send = fc_exch_seq_send;
2059 if (!lp->tt.seq_send)
2060 lp->tt.seq_send = fc_seq_send;
2062 if (!lp->tt.seq_els_rsp_send)
2063 lp->tt.seq_els_rsp_send = fc_seq_els_rsp_send;
2065 if (!lp->tt.exch_done)
2066 lp->tt.exch_done = fc_exch_done;
2068 if (!lp->tt.exch_mgr_reset)
2069 lp->tt.exch_mgr_reset = fc_exch_mgr_reset;
2071 if (!lp->tt.seq_exch_abort)
2072 lp->tt.seq_exch_abort = fc_seq_exch_abort;
2076 EXPORT_SYMBOL(fc_exch_init);
2079 * fc_setup_exch_mgr() - Setup an exchange manager
2081 int fc_setup_exch_mgr()
2083 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2084 0, SLAB_HWCACHE_ALIGN, NULL);
2089 * Initialize fc_cpu_mask and fc_cpu_order. The
2090 * fc_cpu_mask is set for nr_cpu_ids rounded up
2091 * to order of 2's * power and order is stored
2092 * in fc_cpu_order as this is later required in
2093 * mapping between an exch id and exch array index
2094 * in per cpu exch pool.
2096 * This round up is required to align fc_cpu_mask
2097 * to exchange id's lower bits such that all incoming
2098 * frames of an exchange gets delivered to the same
2099 * cpu on which exchange originated by simple bitwise
2100 * AND operation between fc_cpu_mask and exchange id.
2104 while (fc_cpu_mask < nr_cpu_ids) {
2113 void fc_destroy_exch_mgr(void)
2115 kmem_cache_destroy(fc_em_cachep);