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>
37 u16 fc_cpu_mask; /* cpu mask for possible cpus */
38 EXPORT_SYMBOL(fc_cpu_mask);
39 static u16 fc_cpu_order; /* 2's power to represent total possible cpus */
40 static struct kmem_cache *fc_em_cachep; /* cache for exchanges */
43 * Structure and function definitions for managing Fibre Channel Exchanges
46 * The three primary structures used here are fc_exch_mgr, fc_exch, and fc_seq.
48 * fc_exch_mgr holds the exchange state for an N port
50 * fc_exch holds state for one exchange and links to its active sequence.
52 * fc_seq holds the state for an individual sequence.
56 * Per cpu exchange pool
58 * This structure manages per cpu exchanges in array of exchange pointers.
59 * This array is allocated followed by struct fc_exch_pool memory for
60 * assigned range of exchanges to per cpu pool.
63 u16 next_index; /* next possible free exchange index */
64 u16 total_exches; /* total allocated exchanges */
65 spinlock_t lock; /* exch pool lock */
66 struct list_head ex_list; /* allocated exchanges list */
72 * This structure is the center for creating exchanges and sequences.
73 * It manages the allocation of exchange IDs.
76 enum fc_class class; /* default class for sequences */
77 struct kref kref; /* exchange mgr reference count */
78 u16 min_xid; /* min exchange ID */
79 u16 max_xid; /* max exchange ID */
80 mempool_t *ep_pool; /* reserve ep's */
81 u16 pool_max_index; /* max exch array index in exch pool */
82 struct fc_exch_pool *pool; /* per cpu exch pool */
85 * currently exchange mgr stats are updated but not used.
86 * either stats can be expose via sysfs or remove them
87 * all together if not used XXX
90 atomic_t no_free_exch;
91 atomic_t no_free_exch_xid;
92 atomic_t xid_not_found;
94 atomic_t seq_not_found;
95 atomic_t non_bls_resp;
98 #define fc_seq_exch(sp) container_of(sp, struct fc_exch, seq)
100 struct fc_exch_mgr_anchor {
101 struct list_head ema_list;
102 struct fc_exch_mgr *mp;
103 bool (*match)(struct fc_frame *);
106 static void fc_exch_rrq(struct fc_exch *);
107 static void fc_seq_ls_acc(struct fc_seq *);
108 static void fc_seq_ls_rjt(struct fc_seq *, enum fc_els_rjt_reason,
109 enum fc_els_rjt_explan);
110 static void fc_exch_els_rec(struct fc_seq *, struct fc_frame *);
111 static void fc_exch_els_rrq(struct fc_seq *, struct fc_frame *);
114 * Internal implementation notes.
116 * The exchange manager is one by default in libfc but LLD may choose
117 * to have one per CPU. The sequence manager is one per exchange manager
118 * and currently never separated.
120 * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field
121 * assigned by the Sequence Initiator that shall be unique for a specific
122 * D_ID and S_ID pair while the Sequence is open." Note that it isn't
123 * qualified by exchange ID, which one might think it would be.
124 * In practice this limits the number of open sequences and exchanges to 256
125 * per session. For most targets we could treat this limit as per exchange.
127 * The exchange and its sequence are freed when the last sequence is received.
128 * It's possible for the remote port to leave an exchange open without
129 * sending any sequences.
131 * Notes on reference counts:
133 * Exchanges are reference counted and exchange gets freed when the reference
134 * count becomes zero.
137 * Sequences are timed out for E_D_TOV and R_A_TOV.
139 * Sequence event handling:
141 * The following events may occur on initiator sequences:
144 * For now, the whole thing is sent.
146 * This applies only to class F.
147 * The sequence is marked complete.
149 * The upper layer calls fc_exch_done() when done
150 * with exchange and sequence tuple.
151 * RX-inferred completion.
152 * When we receive the next sequence on the same exchange, we can
153 * retire the previous sequence ID. (XXX not implemented).
155 * R_A_TOV frees the sequence ID. If we're waiting for ACK,
156 * E_D_TOV causes abort and calls upper layer response handler
157 * with FC_EX_TIMEOUT error.
163 * The following events may occur on recipient sequences:
166 * Allocate sequence for first frame received.
167 * Hold during receive handler.
168 * Release when final frame received.
169 * Keep status of last N of these for the ELS RES command. XXX TBD.
171 * Deallocate sequence
175 * For now, we neglect conditions where only part of a sequence was
176 * received or transmitted, or where out-of-order receipt is detected.
182 * The EM code run in a per-CPU worker thread.
184 * To protect against concurrency between a worker thread code and timers,
185 * sequence allocation and deallocation must be locked.
186 * - exchange refcnt can be done atomicly without locks.
187 * - sequence allocation must be locked by exch lock.
188 * - If the EM pool lock and ex_lock must be taken at the same time, then the
189 * EM pool lock must be taken before the ex_lock.
193 * opcode names for debugging.
195 static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;
197 #define FC_TABLE_SIZE(x) (sizeof(x) / sizeof(x[0]))
199 static inline const char *fc_exch_name_lookup(unsigned int op, char **table,
200 unsigned int max_index)
202 const char *name = NULL;
211 static const char *fc_exch_rctl_name(unsigned int op)
213 return fc_exch_name_lookup(op, fc_exch_rctl_names,
214 FC_TABLE_SIZE(fc_exch_rctl_names));
218 * Hold an exchange - keep it from being freed.
220 static void fc_exch_hold(struct fc_exch *ep)
222 atomic_inc(&ep->ex_refcnt);
226 * setup fc hdr by initializing few more FC header fields and sof/eof.
227 * Initialized fields by this func:
228 * - fh_ox_id, fh_rx_id, fh_seq_id, fh_seq_cnt
231 static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,
234 struct fc_frame_header *fh = fc_frame_header_get(fp);
237 fr_sof(fp) = ep->class;
239 fr_sof(fp) = fc_sof_normal(ep->class);
241 if (f_ctl & FC_FC_END_SEQ) {
242 fr_eof(fp) = FC_EOF_T;
243 if (fc_sof_needs_ack(ep->class))
244 fr_eof(fp) = FC_EOF_N;
247 * The number of fill bytes to make the length a 4-byte
248 * multiple is the low order 2-bits of the f_ctl.
249 * The fill itself will have been cleared by the frame
251 * After this, the length will be even, as expected by
254 fill = fr_len(fp) & 3;
257 /* TODO, this may be a problem with fragmented skb */
258 skb_put(fp_skb(fp), fill);
259 hton24(fh->fh_f_ctl, f_ctl | fill);
262 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
263 fr_eof(fp) = FC_EOF_N;
267 * Initialize remainig fh fields
268 * from fc_fill_fc_hdr
270 fh->fh_ox_id = htons(ep->oxid);
271 fh->fh_rx_id = htons(ep->rxid);
272 fh->fh_seq_id = ep->seq.id;
273 fh->fh_seq_cnt = htons(ep->seq.cnt);
277 * Release a reference to an exchange.
278 * If the refcnt goes to zero and the exchange is complete, it is freed.
280 static void fc_exch_release(struct fc_exch *ep)
282 struct fc_exch_mgr *mp;
284 if (atomic_dec_and_test(&ep->ex_refcnt)) {
287 ep->destructor(&ep->seq, ep->arg);
288 WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));
289 mempool_free(ep, mp->ep_pool);
293 static int fc_exch_done_locked(struct fc_exch *ep)
298 * We must check for completion in case there are two threads
299 * tyring to complete this. But the rrq code will reuse the
300 * ep, and in that case we only clear the resp and set it as
301 * complete, so it can be reused by the timer to send the rrq.
304 if (ep->state & FC_EX_DONE)
306 ep->esb_stat |= ESB_ST_COMPLETE;
308 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
309 ep->state |= FC_EX_DONE;
310 if (cancel_delayed_work(&ep->timeout_work))
311 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
317 static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,
320 struct fc_exch **exches = (struct fc_exch **)(pool + 1);
321 return exches[index];
324 static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
327 ((struct fc_exch **)(pool + 1))[index] = ep;
330 static void fc_exch_delete(struct fc_exch *ep)
332 struct fc_exch_pool *pool;
335 spin_lock_bh(&pool->lock);
336 WARN_ON(pool->total_exches <= 0);
337 pool->total_exches--;
338 fc_exch_ptr_set(pool, (ep->xid - ep->em->min_xid) >> fc_cpu_order,
340 list_del(&ep->ex_list);
341 spin_unlock_bh(&pool->lock);
342 fc_exch_release(ep); /* drop hold for exch in mp */
346 * Internal version of fc_exch_timer_set - used with lock held.
348 static inline void fc_exch_timer_set_locked(struct fc_exch *ep,
349 unsigned int timer_msec)
351 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
354 FC_EXCH_DBG(ep, "Exchange timer armed\n");
356 if (schedule_delayed_work(&ep->timeout_work,
357 msecs_to_jiffies(timer_msec)))
358 fc_exch_hold(ep); /* hold for timer */
362 * Set timer for an exchange.
363 * The time is a minimum delay in milliseconds until the timer fires.
364 * Used for upper level protocols to time out the exchange.
365 * The timer is cancelled when it fires or when the exchange completes.
366 * Returns non-zero if a timer couldn't be allocated.
368 static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec)
370 spin_lock_bh(&ep->ex_lock);
371 fc_exch_timer_set_locked(ep, timer_msec);
372 spin_unlock_bh(&ep->ex_lock);
376 * send a frame using existing sequence and exchange.
378 static int fc_seq_send(struct fc_lport *lp, struct fc_seq *sp,
382 struct fc_frame_header *fh = fc_frame_header_get(fp);
386 ep = fc_seq_exch(sp);
387 WARN_ON((ep->esb_stat & ESB_ST_SEQ_INIT) != ESB_ST_SEQ_INIT);
389 f_ctl = ntoh24(fh->fh_f_ctl);
390 fc_exch_setup_hdr(ep, fp, f_ctl);
393 * update sequence count if this frame is carrying
394 * multiple FC frames when sequence offload is enabled
397 if (fr_max_payload(fp))
398 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),
406 error = lp->tt.frame_send(lp, fp);
409 * Update the exchange and sequence flags,
410 * assuming all frames for the sequence have been sent.
411 * We can only be called to send once for each sequence.
413 spin_lock_bh(&ep->ex_lock);
414 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
415 if (f_ctl & (FC_FC_END_SEQ | FC_FC_SEQ_INIT))
416 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
417 spin_unlock_bh(&ep->ex_lock);
422 * fc_seq_alloc() - Allocate a sequence.
423 * @ep: Exchange pointer
424 * @seq_id: Sequence ID to allocate a sequence for
426 * We don't support multiple originated sequences on the same exchange.
427 * By implication, any previously originated sequence on this exchange
428 * is complete, and we reallocate the same sequence.
430 static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
441 static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
443 struct fc_exch *ep = fc_seq_exch(sp);
445 sp = fc_seq_alloc(ep, ep->seq_id++);
446 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
452 * Allocate a new sequence on the same exchange as the supplied sequence.
453 * This will never return NULL.
455 static struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
457 struct fc_exch *ep = fc_seq_exch(sp);
459 spin_lock_bh(&ep->ex_lock);
460 sp = fc_seq_start_next_locked(sp);
461 spin_unlock_bh(&ep->ex_lock);
467 * This function is for seq_exch_abort function pointer in
468 * struct libfc_function_template, see comment block on
469 * seq_exch_abort for description of this function.
471 static int fc_seq_exch_abort(const struct fc_seq *req_sp,
472 unsigned int timer_msec)
479 ep = fc_seq_exch(req_sp);
481 spin_lock_bh(&ep->ex_lock);
482 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
483 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
484 spin_unlock_bh(&ep->ex_lock);
489 * Send the abort on a new sequence if possible.
491 sp = fc_seq_start_next_locked(&ep->seq);
493 spin_unlock_bh(&ep->ex_lock);
497 ep->esb_stat |= ESB_ST_SEQ_INIT | ESB_ST_ABNORMAL;
499 fc_exch_timer_set_locked(ep, timer_msec);
500 spin_unlock_bh(&ep->ex_lock);
503 * If not logged into the fabric, don't send ABTS but leave
504 * sequence active until next timeout.
510 * Send an abort for the sequence that timed out.
512 fp = fc_frame_alloc(ep->lp, 0);
514 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
515 FC_TYPE_BLS, FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
516 error = fc_seq_send(ep->lp, sp, fp);
523 * Exchange timeout - handle exchange timer expiration.
524 * The timer will have been cancelled before this is called.
526 static void fc_exch_timeout(struct work_struct *work)
528 struct fc_exch *ep = container_of(work, struct fc_exch,
530 struct fc_seq *sp = &ep->seq;
531 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
536 FC_EXCH_DBG(ep, "Exchange timed out\n");
538 spin_lock_bh(&ep->ex_lock);
539 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
542 e_stat = ep->esb_stat;
543 if (e_stat & ESB_ST_COMPLETE) {
544 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
545 spin_unlock_bh(&ep->ex_lock);
546 if (e_stat & ESB_ST_REC_QUAL)
553 if (e_stat & ESB_ST_ABNORMAL)
554 rc = fc_exch_done_locked(ep);
555 spin_unlock_bh(&ep->ex_lock);
559 resp(sp, ERR_PTR(-FC_EX_TIMEOUT), arg);
560 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
564 spin_unlock_bh(&ep->ex_lock);
567 * This release matches the hold taken when the timer was set.
573 * fc_exch_em_alloc() - allocate an exchange from a specified EM.
574 * @lport: ptr to the local port
575 * @mp: ptr to the exchange manager
577 * Returns pointer to allocated fc_exch with exch lock held.
579 static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
580 struct fc_exch_mgr *mp)
585 struct fc_exch_pool *pool;
587 /* allocate memory for exchange */
588 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);
590 atomic_inc(&mp->stats.no_free_exch);
593 memset(ep, 0, sizeof(*ep));
595 cpu = smp_processor_id();
596 pool = per_cpu_ptr(mp->pool, cpu);
597 spin_lock_bh(&pool->lock);
598 index = pool->next_index;
599 /* allocate new exch from pool */
600 while (fc_exch_ptr_get(pool, index)) {
601 index = index == mp->pool_max_index ? 0 : index + 1;
602 if (index == pool->next_index)
605 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
607 fc_exch_hold(ep); /* hold for exch in mp */
608 spin_lock_init(&ep->ex_lock);
610 * Hold exch lock for caller to prevent fc_exch_reset()
611 * from releasing exch while fc_exch_alloc() caller is
612 * still working on exch.
614 spin_lock_bh(&ep->ex_lock);
616 fc_exch_ptr_set(pool, index, ep);
617 list_add_tail(&ep->ex_list, &pool->ex_list);
618 fc_seq_alloc(ep, ep->seq_id++);
619 pool->total_exches++;
620 spin_unlock_bh(&pool->lock);
625 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
629 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
630 ep->rxid = FC_XID_UNKNOWN;
631 ep->class = mp->class;
632 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
636 spin_unlock_bh(&pool->lock);
637 atomic_inc(&mp->stats.no_free_exch_xid);
638 mempool_free(ep, mp->ep_pool);
643 * fc_exch_alloc() - allocate an exchange.
644 * @lport: ptr to the local port
645 * @fp: ptr to the FC frame
647 * This function walks the list of the exchange manager(EM)
648 * anchors to select a EM for new exchange allocation. The
649 * EM is selected having either a NULL match function pointer
650 * or call to match function returning true.
652 static struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
655 struct fc_exch_mgr_anchor *ema;
658 list_for_each_entry(ema, &lport->ema_list, ema_list) {
659 if (!ema->match || ema->match(fp)) {
660 ep = fc_exch_em_alloc(lport, ema->mp);
669 * Lookup and hold an exchange.
671 static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
673 struct fc_exch_pool *pool;
674 struct fc_exch *ep = NULL;
676 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
677 pool = per_cpu_ptr(mp->pool, xid & fc_cpu_mask);
678 spin_lock_bh(&pool->lock);
679 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
682 WARN_ON(ep->xid != xid);
684 spin_unlock_bh(&pool->lock);
691 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and
692 * the memory allocated for the related objects may be freed.
693 * @sp: Sequence pointer
695 static void fc_exch_done(struct fc_seq *sp)
697 struct fc_exch *ep = fc_seq_exch(sp);
700 spin_lock_bh(&ep->ex_lock);
701 rc = fc_exch_done_locked(ep);
702 spin_unlock_bh(&ep->ex_lock);
708 * Allocate a new exchange as responder.
709 * Sets the responder ID in the frame header.
711 static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
712 struct fc_exch_mgr *mp,
716 struct fc_frame_header *fh;
718 ep = fc_exch_alloc(lport, fp);
720 ep->class = fc_frame_class(fp);
723 * Set EX_CTX indicating we're responding on this exchange.
725 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
726 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
727 fh = fc_frame_header_get(fp);
728 ep->sid = ntoh24(fh->fh_d_id);
729 ep->did = ntoh24(fh->fh_s_id);
733 * Allocated exchange has placed the XID in the
734 * originator field. Move it to the responder field,
735 * and set the originator XID from the frame.
738 ep->oxid = ntohs(fh->fh_ox_id);
739 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
740 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
741 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
743 fc_exch_hold(ep); /* hold for caller */
744 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
750 * Find a sequence for receive where the other end is originating the sequence.
751 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
752 * on the ep that should be released by the caller.
754 static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
755 struct fc_exch_mgr *mp,
758 struct fc_frame_header *fh = fc_frame_header_get(fp);
759 struct fc_exch *ep = NULL;
760 struct fc_seq *sp = NULL;
761 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
765 f_ctl = ntoh24(fh->fh_f_ctl);
766 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
769 * Lookup or create the exchange if we will be creating the sequence.
771 if (f_ctl & FC_FC_EX_CTX) {
772 xid = ntohs(fh->fh_ox_id); /* we originated exch */
773 ep = fc_exch_find(mp, xid);
775 atomic_inc(&mp->stats.xid_not_found);
776 reject = FC_RJT_OX_ID;
779 if (ep->rxid == FC_XID_UNKNOWN)
780 ep->rxid = ntohs(fh->fh_rx_id);
781 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
782 reject = FC_RJT_OX_ID;
786 xid = ntohs(fh->fh_rx_id); /* we are the responder */
789 * Special case for MDS issuing an ELS TEST with a
791 * XXX take this out once we do the proper reject.
793 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
794 fc_frame_payload_op(fp) == ELS_TEST) {
795 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
796 xid = FC_XID_UNKNOWN;
800 * new sequence - find the exchange
802 ep = fc_exch_find(mp, xid);
803 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
805 atomic_inc(&mp->stats.xid_busy);
806 reject = FC_RJT_RX_ID;
809 ep = fc_exch_resp(lport, mp, fp);
811 reject = FC_RJT_EXCH_EST; /* XXX */
814 xid = ep->xid; /* get our XID */
816 atomic_inc(&mp->stats.xid_not_found);
817 reject = FC_RJT_RX_ID; /* XID not found */
823 * At this point, we have the exchange held.
824 * Find or create the sequence.
826 if (fc_sof_is_init(fr_sof(fp))) {
827 sp = fc_seq_start_next(&ep->seq);
829 reject = FC_RJT_SEQ_XS; /* exchange shortage */
832 sp->id = fh->fh_seq_id;
833 sp->ssb_stat |= SSB_ST_RESP;
836 if (sp->id != fh->fh_seq_id) {
837 atomic_inc(&mp->stats.seq_not_found);
838 reject = FC_RJT_SEQ_ID; /* sequence/exch should exist */
842 WARN_ON(ep != fc_seq_exch(sp));
844 if (f_ctl & FC_FC_SEQ_INIT)
845 ep->esb_stat |= ESB_ST_SEQ_INIT;
851 fc_exch_done(&ep->seq);
852 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
857 * Find the sequence for a frame being received.
858 * We originated the sequence, so it should be found.
859 * We may or may not have originated the exchange.
860 * Does not hold the sequence for the caller.
862 static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
865 struct fc_frame_header *fh = fc_frame_header_get(fp);
867 struct fc_seq *sp = NULL;
871 f_ctl = ntoh24(fh->fh_f_ctl);
872 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
873 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
874 ep = fc_exch_find(mp, xid);
877 if (ep->seq.id == fh->fh_seq_id) {
879 * Save the RX_ID if we didn't previously know it.
882 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
883 ep->rxid == FC_XID_UNKNOWN) {
884 ep->rxid = ntohs(fh->fh_rx_id);
892 * Set addresses for an exchange.
893 * Note this must be done before the first sequence of the exchange is sent.
895 static void fc_exch_set_addr(struct fc_exch *ep,
896 u32 orig_id, u32 resp_id)
899 if (ep->esb_stat & ESB_ST_RESP) {
909 * fc_seq_els_rsp_send() - Send ELS response using mainly infomation
910 * in exchange and sequence in EM layer.
911 * @sp: Sequence pointer
912 * @els_cmd: ELS command
913 * @els_data: ELS data
915 static void fc_seq_els_rsp_send(struct fc_seq *sp, enum fc_els_cmd els_cmd,
916 struct fc_seq_els_data *els_data)
920 fc_seq_ls_rjt(sp, els_data->reason, els_data->explan);
926 fc_exch_els_rrq(sp, els_data->fp);
929 fc_exch_els_rec(sp, els_data->fp);
932 FC_EXCH_DBG(fc_seq_exch(sp), "Invalid ELS CMD:%x\n", els_cmd);
937 * Send a sequence, which is also the last sequence in the exchange.
939 static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
940 enum fc_rctl rctl, enum fc_fh_type fh_type)
943 struct fc_exch *ep = fc_seq_exch(sp);
945 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
947 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
948 fc_seq_send(ep->lp, sp, fp);
952 * Send ACK_1 (or equiv.) indicating we received something.
953 * The frame we're acking is supplied.
955 static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
958 struct fc_frame_header *rx_fh;
959 struct fc_frame_header *fh;
960 struct fc_exch *ep = fc_seq_exch(sp);
961 struct fc_lport *lp = ep->lp;
965 * Don't send ACKs for class 3.
967 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
968 fp = fc_frame_alloc(lp, 0);
972 fh = fc_frame_header_get(fp);
973 fh->fh_r_ctl = FC_RCTL_ACK_1;
974 fh->fh_type = FC_TYPE_BLS;
977 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
978 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
979 * Bits 9-8 are meaningful (retransmitted or unidirectional).
980 * Last ACK uses bits 7-6 (continue sequence),
981 * bits 5-4 are meaningful (what kind of ACK to use).
983 rx_fh = fc_frame_header_get(rx_fp);
984 f_ctl = ntoh24(rx_fh->fh_f_ctl);
985 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
986 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
987 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
988 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
989 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
990 hton24(fh->fh_f_ctl, f_ctl);
992 fc_exch_setup_hdr(ep, fp, f_ctl);
993 fh->fh_seq_id = rx_fh->fh_seq_id;
994 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
995 fh->fh_parm_offset = htonl(1); /* ack single frame */
997 fr_sof(fp) = fr_sof(rx_fp);
998 if (f_ctl & FC_FC_END_SEQ)
999 fr_eof(fp) = FC_EOF_T;
1001 fr_eof(fp) = FC_EOF_N;
1003 (void) lp->tt.frame_send(lp, fp);
1009 * This is for rejecting BA_ABTS only.
1011 static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
1012 enum fc_ba_rjt_reason reason,
1013 enum fc_ba_rjt_explan explan)
1015 struct fc_frame *fp;
1016 struct fc_frame_header *rx_fh;
1017 struct fc_frame_header *fh;
1018 struct fc_ba_rjt *rp;
1019 struct fc_lport *lp;
1023 fp = fc_frame_alloc(lp, sizeof(*rp));
1026 fh = fc_frame_header_get(fp);
1027 rx_fh = fc_frame_header_get(rx_fp);
1029 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1031 rp = fc_frame_payload_get(fp, sizeof(*rp));
1032 rp->br_reason = reason;
1033 rp->br_explan = explan;
1036 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1038 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1039 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1040 fh->fh_ox_id = rx_fh->fh_ox_id;
1041 fh->fh_rx_id = rx_fh->fh_rx_id;
1042 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1043 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1044 fh->fh_type = FC_TYPE_BLS;
1047 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1048 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1049 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1050 * Last ACK uses bits 7-6 (continue sequence),
1051 * bits 5-4 are meaningful (what kind of ACK to use).
1052 * Always set LAST_SEQ, END_SEQ.
1054 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1055 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1056 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1057 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1058 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1059 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1060 f_ctl &= ~FC_FC_FIRST_SEQ;
1061 hton24(fh->fh_f_ctl, f_ctl);
1063 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1064 fr_eof(fp) = FC_EOF_T;
1065 if (fc_sof_needs_ack(fr_sof(fp)))
1066 fr_eof(fp) = FC_EOF_N;
1068 (void) lp->tt.frame_send(lp, fp);
1072 * Handle an incoming ABTS. This would be for target mode usually,
1073 * but could be due to lost FCP transfer ready, confirm or RRQ.
1074 * We always handle this as an exchange abort, ignoring the parameter.
1076 static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1078 struct fc_frame *fp;
1079 struct fc_ba_acc *ap;
1080 struct fc_frame_header *fh;
1085 spin_lock_bh(&ep->ex_lock);
1086 if (ep->esb_stat & ESB_ST_COMPLETE) {
1087 spin_unlock_bh(&ep->ex_lock);
1090 if (!(ep->esb_stat & ESB_ST_REC_QUAL))
1091 fc_exch_hold(ep); /* hold for REC_QUAL */
1092 ep->esb_stat |= ESB_ST_ABNORMAL | ESB_ST_REC_QUAL;
1093 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1095 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1097 spin_unlock_bh(&ep->ex_lock);
1100 fh = fc_frame_header_get(fp);
1101 ap = fc_frame_payload_get(fp, sizeof(*ap));
1102 memset(ap, 0, sizeof(*ap));
1104 ap->ba_high_seq_cnt = htons(0xffff);
1105 if (sp->ssb_stat & SSB_ST_RESP) {
1106 ap->ba_seq_id = sp->id;
1107 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1108 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1109 ap->ba_low_seq_cnt = htons(sp->cnt);
1111 sp = fc_seq_start_next_locked(sp);
1112 spin_unlock_bh(&ep->ex_lock);
1113 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1114 fc_frame_free(rx_fp);
1118 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1120 fc_frame_free(rx_fp);
1124 * Handle receive where the other end is originating the sequence.
1126 static void fc_exch_recv_req(struct fc_lport *lp, struct fc_exch_mgr *mp,
1127 struct fc_frame *fp)
1129 struct fc_frame_header *fh = fc_frame_header_get(fp);
1130 struct fc_seq *sp = NULL;
1131 struct fc_exch *ep = NULL;
1135 enum fc_pf_rjt_reason reject;
1137 /* We can have the wrong fc_lport at this point with NPIV, which is a
1138 * problem now that we know a new exchange needs to be allocated
1140 lp = fc_vport_id_lookup(lp, ntoh24(fh->fh_d_id));
1147 reject = fc_seq_lookup_recip(lp, mp, fp);
1148 if (reject == FC_RJT_NONE) {
1149 sp = fr_seq(fp); /* sequence will be held */
1150 ep = fc_seq_exch(sp);
1153 f_ctl = ntoh24(fh->fh_f_ctl);
1154 fc_seq_send_ack(sp, fp);
1157 * Call the receive function.
1159 * The receive function may allocate a new sequence
1160 * over the old one, so we shouldn't change the
1161 * sequence after this.
1163 * The frame will be freed by the receive function.
1164 * If new exch resp handler is valid then call that
1168 ep->resp(sp, fp, ep->arg);
1170 lp->tt.lport_recv(lp, sp, fp);
1171 fc_exch_release(ep); /* release from lookup */
1173 FC_LPORT_DBG(lp, "exch/seq lookup failed: reject %x\n", reject);
1179 * Handle receive where the other end is originating the sequence in
1180 * response to our exchange.
1182 static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1184 struct fc_frame_header *fh = fc_frame_header_get(fp);
1189 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
1193 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1195 atomic_inc(&mp->stats.xid_not_found);
1198 if (ep->esb_stat & ESB_ST_COMPLETE) {
1199 atomic_inc(&mp->stats.xid_not_found);
1202 if (ep->rxid == FC_XID_UNKNOWN)
1203 ep->rxid = ntohs(fh->fh_rx_id);
1204 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1205 atomic_inc(&mp->stats.xid_not_found);
1208 if (ep->did != ntoh24(fh->fh_s_id) &&
1209 ep->did != FC_FID_FLOGI) {
1210 atomic_inc(&mp->stats.xid_not_found);
1214 if (fc_sof_is_init(sof)) {
1215 sp = fc_seq_start_next(&ep->seq);
1216 sp->id = fh->fh_seq_id;
1217 sp->ssb_stat |= SSB_ST_RESP;
1220 if (sp->id != fh->fh_seq_id) {
1221 atomic_inc(&mp->stats.seq_not_found);
1225 f_ctl = ntoh24(fh->fh_f_ctl);
1227 if (f_ctl & FC_FC_SEQ_INIT)
1228 ep->esb_stat |= ESB_ST_SEQ_INIT;
1230 if (fc_sof_needs_ack(sof))
1231 fc_seq_send_ack(sp, fp);
1233 ex_resp_arg = ep->arg;
1235 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1236 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1237 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1238 spin_lock_bh(&ep->ex_lock);
1239 rc = fc_exch_done_locked(ep);
1240 WARN_ON(fc_seq_exch(sp) != ep);
1241 spin_unlock_bh(&ep->ex_lock);
1247 * Call the receive function.
1248 * The sequence is held (has a refcnt) for us,
1249 * but not for the receive function.
1251 * The receive function may allocate a new sequence
1252 * over the old one, so we shouldn't change the
1253 * sequence after this.
1255 * The frame will be freed by the receive function.
1256 * If new exch resp handler is valid then call that
1260 resp(sp, fp, ex_resp_arg);
1263 fc_exch_release(ep);
1266 fc_exch_release(ep);
1272 * Handle receive for a sequence where other end is responding to our sequence.
1274 static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1278 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1281 atomic_inc(&mp->stats.xid_not_found);
1283 atomic_inc(&mp->stats.non_bls_resp);
1289 * Handle the response to an ABTS for exchange or sequence.
1290 * This can be BA_ACC or BA_RJT.
1292 static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1294 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
1296 struct fc_frame_header *fh;
1297 struct fc_ba_acc *ap;
1301 int rc = 1, has_rec = 0;
1303 fh = fc_frame_header_get(fp);
1304 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1305 fc_exch_rctl_name(fh->fh_r_ctl));
1307 if (cancel_delayed_work_sync(&ep->timeout_work))
1308 fc_exch_release(ep); /* release from pending timer hold */
1310 spin_lock_bh(&ep->ex_lock);
1311 switch (fh->fh_r_ctl) {
1312 case FC_RCTL_BA_ACC:
1313 ap = fc_frame_payload_get(fp, sizeof(*ap));
1318 * Decide whether to establish a Recovery Qualifier.
1319 * We do this if there is a non-empty SEQ_CNT range and
1320 * SEQ_ID is the same as the one we aborted.
1322 low = ntohs(ap->ba_low_seq_cnt);
1323 high = ntohs(ap->ba_high_seq_cnt);
1324 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1325 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1326 ap->ba_seq_id == ep->seq_id) && low != high) {
1327 ep->esb_stat |= ESB_ST_REC_QUAL;
1328 fc_exch_hold(ep); /* hold for recovery qualifier */
1332 case FC_RCTL_BA_RJT:
1339 ex_resp_arg = ep->arg;
1341 /* do we need to do some other checks here. Can we reuse more of
1342 * fc_exch_recv_seq_resp
1346 * do we want to check END_SEQ as well as LAST_SEQ here?
1348 if (ep->fh_type != FC_TYPE_FCP &&
1349 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1350 rc = fc_exch_done_locked(ep);
1351 spin_unlock_bh(&ep->ex_lock);
1356 resp(sp, fp, ex_resp_arg);
1361 fc_exch_timer_set(ep, ep->r_a_tov);
1366 * Receive BLS sequence.
1367 * This is always a sequence initiated by the remote side.
1368 * We may be either the originator or recipient of the exchange.
1370 static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1372 struct fc_frame_header *fh;
1376 fh = fc_frame_header_get(fp);
1377 f_ctl = ntoh24(fh->fh_f_ctl);
1380 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1381 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1382 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1383 spin_lock_bh(&ep->ex_lock);
1384 ep->esb_stat |= ESB_ST_SEQ_INIT;
1385 spin_unlock_bh(&ep->ex_lock);
1387 if (f_ctl & FC_FC_SEQ_CTX) {
1389 * A response to a sequence we initiated.
1390 * This should only be ACKs for class 2 or F.
1392 switch (fh->fh_r_ctl) {
1397 FC_EXCH_DBG(ep, "BLS rctl %x - %s received",
1399 fc_exch_rctl_name(fh->fh_r_ctl));
1404 switch (fh->fh_r_ctl) {
1405 case FC_RCTL_BA_RJT:
1406 case FC_RCTL_BA_ACC:
1408 fc_exch_abts_resp(ep, fp);
1412 case FC_RCTL_BA_ABTS:
1413 fc_exch_recv_abts(ep, fp);
1415 default: /* ignore junk */
1421 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1425 * Accept sequence with LS_ACC.
1426 * If this fails due to allocation or transmit congestion, assume the
1427 * originator will repeat the sequence.
1429 static void fc_seq_ls_acc(struct fc_seq *req_sp)
1432 struct fc_els_ls_acc *acc;
1433 struct fc_frame *fp;
1435 sp = fc_seq_start_next(req_sp);
1436 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*acc));
1438 acc = fc_frame_payload_get(fp, sizeof(*acc));
1439 memset(acc, 0, sizeof(*acc));
1440 acc->la_cmd = ELS_LS_ACC;
1441 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1446 * Reject sequence with ELS LS_RJT.
1447 * If this fails due to allocation or transmit congestion, assume the
1448 * originator will repeat the sequence.
1450 static void fc_seq_ls_rjt(struct fc_seq *req_sp, enum fc_els_rjt_reason reason,
1451 enum fc_els_rjt_explan explan)
1454 struct fc_els_ls_rjt *rjt;
1455 struct fc_frame *fp;
1457 sp = fc_seq_start_next(req_sp);
1458 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*rjt));
1460 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1461 memset(rjt, 0, sizeof(*rjt));
1462 rjt->er_cmd = ELS_LS_RJT;
1463 rjt->er_reason = reason;
1464 rjt->er_explan = explan;
1465 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1469 static void fc_exch_reset(struct fc_exch *ep)
1472 void (*resp)(struct fc_seq *, struct fc_frame *, void *);
1476 spin_lock_bh(&ep->ex_lock);
1477 ep->state |= FC_EX_RST_CLEANUP;
1479 * we really want to call del_timer_sync, but cannot due
1480 * to the lport calling with the lport lock held (some resp
1481 * functions can also grab the lport lock which could cause
1484 if (cancel_delayed_work(&ep->timeout_work))
1485 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
1488 if (ep->esb_stat & ESB_ST_REC_QUAL)
1489 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1490 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1493 rc = fc_exch_done_locked(ep);
1494 spin_unlock_bh(&ep->ex_lock);
1499 resp(sp, ERR_PTR(-FC_EX_CLOSED), arg);
1503 * fc_exch_pool_reset() - Resets an per cpu exches pool.
1504 * @lport: ptr to the local port
1505 * @pool: ptr to the per cpu exches pool
1506 * @sid: source FC ID
1507 * @did: destination FC ID
1509 * Resets an per cpu exches pool, releasing its all sequences
1510 * and exchanges. If sid is non-zero, then reset only exchanges
1511 * we sourced from that FID. If did is non-zero, reset only
1512 * exchanges destined to that FID.
1514 static void fc_exch_pool_reset(struct fc_lport *lport,
1515 struct fc_exch_pool *pool,
1519 struct fc_exch *next;
1521 spin_lock_bh(&pool->lock);
1523 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1524 if ((lport == ep->lp) &&
1525 (sid == 0 || sid == ep->sid) &&
1526 (did == 0 || did == ep->did)) {
1528 spin_unlock_bh(&pool->lock);
1532 fc_exch_release(ep);
1533 spin_lock_bh(&pool->lock);
1536 * must restart loop incase while lock
1537 * was down multiple eps were released.
1542 spin_unlock_bh(&pool->lock);
1546 * fc_exch_mgr_reset() - Resets all EMs of a lport
1547 * @lport: ptr to the local port
1548 * @sid: source FC ID
1549 * @did: destination FC ID
1551 * Reset all EMs of a lport, releasing its all sequences and
1552 * exchanges. If sid is non-zero, then reset only exchanges
1553 * we sourced from that FID. If did is non-zero, reset only
1554 * exchanges destined to that FID.
1556 void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1558 struct fc_exch_mgr_anchor *ema;
1561 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1562 for_each_possible_cpu(cpu)
1563 fc_exch_pool_reset(lport,
1564 per_cpu_ptr(ema->mp->pool, cpu),
1568 EXPORT_SYMBOL(fc_exch_mgr_reset);
1571 * Handle incoming ELS REC - Read Exchange Concise.
1572 * Note that the requesting port may be different than the S_ID in the request.
1574 static void fc_exch_els_rec(struct fc_seq *sp, struct fc_frame *rfp)
1576 struct fc_frame *fp;
1578 struct fc_exch_mgr *em;
1579 struct fc_els_rec *rp;
1580 struct fc_els_rec_acc *acc;
1581 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
1582 enum fc_els_rjt_explan explan;
1587 rp = fc_frame_payload_get(rfp, sizeof(*rp));
1588 explan = ELS_EXPL_INV_LEN;
1591 sid = ntoh24(rp->rec_s_id);
1592 rxid = ntohs(rp->rec_rx_id);
1593 oxid = ntohs(rp->rec_ox_id);
1596 * Currently it's hard to find the local S_ID from the exchange
1597 * manager. This will eventually be fixed, but for now it's easier
1598 * to lookup the subject exchange twice, once as if we were
1599 * the initiator, and then again if we weren't.
1601 em = fc_seq_exch(sp)->em;
1602 ep = fc_exch_find(em, oxid);
1603 explan = ELS_EXPL_OXID_RXID;
1604 if (ep && ep->oid == sid) {
1605 if (ep->rxid != FC_XID_UNKNOWN &&
1606 rxid != FC_XID_UNKNOWN &&
1611 fc_exch_release(ep);
1613 if (rxid != FC_XID_UNKNOWN)
1614 ep = fc_exch_find(em, rxid);
1619 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*acc));
1624 sp = fc_seq_start_next(sp);
1625 acc = fc_frame_payload_get(fp, sizeof(*acc));
1626 memset(acc, 0, sizeof(*acc));
1627 acc->reca_cmd = ELS_LS_ACC;
1628 acc->reca_ox_id = rp->rec_ox_id;
1629 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
1630 acc->reca_rx_id = htons(ep->rxid);
1631 if (ep->sid == ep->oid)
1632 hton24(acc->reca_rfid, ep->did);
1634 hton24(acc->reca_rfid, ep->sid);
1635 acc->reca_fc4value = htonl(ep->seq.rec_data);
1636 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
1639 sp = fc_seq_start_next(sp);
1640 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1642 fc_exch_release(ep);
1647 fc_exch_release(ep);
1649 fc_seq_ls_rjt(sp, reason, explan);
1654 * Handle response from RRQ.
1655 * Not much to do here, really.
1656 * Should report errors.
1658 * TODO: fix error handler.
1660 static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
1662 struct fc_exch *aborted_ep = arg;
1666 int err = PTR_ERR(fp);
1668 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
1670 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
1671 "frame error %d\n", err);
1675 op = fc_frame_payload_op(fp);
1680 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ");
1685 FC_EXCH_DBG(aborted_ep, "unexpected response op %x "
1691 fc_exch_done(&aborted_ep->seq);
1692 /* drop hold for rec qual */
1693 fc_exch_release(aborted_ep);
1698 * This function is for exch_seq_send function pointer in
1699 * struct libfc_function_template, see comment block on
1700 * exch_seq_send for description of this function.
1702 static struct fc_seq *fc_exch_seq_send(struct fc_lport *lp,
1703 struct fc_frame *fp,
1704 void (*resp)(struct fc_seq *,
1705 struct fc_frame *fp,
1707 void (*destructor)(struct fc_seq *,
1709 void *arg, u32 timer_msec)
1712 struct fc_seq *sp = NULL;
1713 struct fc_frame_header *fh;
1716 ep = fc_exch_alloc(lp, fp);
1721 ep->esb_stat |= ESB_ST_SEQ_INIT;
1722 fh = fc_frame_header_get(fp);
1723 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
1725 ep->destructor = destructor;
1727 ep->r_a_tov = FC_DEF_R_A_TOV;
1731 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
1732 ep->f_ctl = ntoh24(fh->fh_f_ctl);
1733 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
1736 if (ep->xid <= lp->lro_xid)
1737 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
1739 if (unlikely(lp->tt.frame_send(lp, fp)))
1743 fc_exch_timer_set_locked(ep, timer_msec);
1744 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
1746 if (ep->f_ctl & FC_FC_SEQ_INIT)
1747 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
1748 spin_unlock_bh(&ep->ex_lock);
1751 rc = fc_exch_done_locked(ep);
1752 spin_unlock_bh(&ep->ex_lock);
1759 * Send ELS RRQ - Reinstate Recovery Qualifier.
1760 * This tells the remote port to stop blocking the use of
1761 * the exchange and the seq_cnt range.
1763 static void fc_exch_rrq(struct fc_exch *ep)
1765 struct fc_lport *lp;
1766 struct fc_els_rrq *rrq;
1767 struct fc_frame *fp;
1772 fp = fc_frame_alloc(lp, sizeof(*rrq));
1776 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
1777 memset(rrq, 0, sizeof(*rrq));
1778 rrq->rrq_cmd = ELS_RRQ;
1779 hton24(rrq->rrq_s_id, ep->sid);
1780 rrq->rrq_ox_id = htons(ep->oxid);
1781 rrq->rrq_rx_id = htons(ep->rxid);
1784 if (ep->esb_stat & ESB_ST_RESP)
1787 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
1788 fc_host_port_id(lp->host), FC_TYPE_ELS,
1789 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1791 if (fc_exch_seq_send(lp, fp, fc_exch_rrq_resp, NULL, ep, lp->e_d_tov))
1795 spin_lock_bh(&ep->ex_lock);
1796 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
1797 spin_unlock_bh(&ep->ex_lock);
1798 /* drop hold for rec qual */
1799 fc_exch_release(ep);
1802 ep->esb_stat |= ESB_ST_REC_QUAL;
1803 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1804 spin_unlock_bh(&ep->ex_lock);
1809 * Handle incoming ELS RRQ - Reset Recovery Qualifier.
1811 static void fc_exch_els_rrq(struct fc_seq *sp, struct fc_frame *fp)
1813 struct fc_exch *ep = NULL; /* request or subject exchange */
1814 struct fc_els_rrq *rp;
1817 enum fc_els_rjt_explan explan;
1819 rp = fc_frame_payload_get(fp, sizeof(*rp));
1820 explan = ELS_EXPL_INV_LEN;
1825 * lookup subject exchange.
1827 ep = fc_seq_exch(sp);
1828 sid = ntoh24(rp->rrq_s_id); /* subject source */
1829 xid = ep->did == sid ? ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
1830 ep = fc_exch_find(ep->em, xid);
1832 explan = ELS_EXPL_OXID_RXID;
1835 spin_lock_bh(&ep->ex_lock);
1836 if (ep->oxid != ntohs(rp->rrq_ox_id))
1838 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
1839 ep->rxid != FC_XID_UNKNOWN)
1841 explan = ELS_EXPL_SID;
1846 * Clear Recovery Qualifier state, and cancel timer if complete.
1848 if (ep->esb_stat & ESB_ST_REC_QUAL) {
1849 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1850 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
1852 if (ep->esb_stat & ESB_ST_COMPLETE) {
1853 if (cancel_delayed_work(&ep->timeout_work))
1854 atomic_dec(&ep->ex_refcnt); /* drop timer hold */
1857 spin_unlock_bh(&ep->ex_lock);
1866 spin_unlock_bh(&ep->ex_lock);
1868 fc_seq_ls_rjt(sp, ELS_RJT_LOGIC, explan);
1872 fc_exch_release(ep); /* drop hold from fc_exch_find */
1875 struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
1876 struct fc_exch_mgr *mp,
1877 bool (*match)(struct fc_frame *))
1879 struct fc_exch_mgr_anchor *ema;
1881 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
1887 /* add EM anchor to EM anchors list */
1888 list_add_tail(&ema->ema_list, &lport->ema_list);
1889 kref_get(&mp->kref);
1892 EXPORT_SYMBOL(fc_exch_mgr_add);
1894 static void fc_exch_mgr_destroy(struct kref *kref)
1896 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
1898 mempool_destroy(mp->ep_pool);
1899 free_percpu(mp->pool);
1903 void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
1905 /* remove EM anchor from EM anchors list */
1906 list_del(&ema->ema_list);
1907 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
1910 EXPORT_SYMBOL(fc_exch_mgr_del);
1913 * fc_exch_mgr_list_clone() - share all exchange manager objects
1914 * @src: source lport to clone exchange managers from
1915 * @dst: new lport that takes references to all the exchange managers
1917 int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)
1919 struct fc_exch_mgr_anchor *ema, *tmp;
1921 list_for_each_entry(ema, &src->ema_list, ema_list) {
1922 if (!fc_exch_mgr_add(dst, ema->mp, ema->match))
1927 list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)
1928 fc_exch_mgr_del(ema);
1932 struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lp,
1933 enum fc_class class,
1934 u16 min_xid, u16 max_xid,
1935 bool (*match)(struct fc_frame *))
1937 struct fc_exch_mgr *mp;
1938 u16 pool_exch_range;
1941 struct fc_exch_pool *pool;
1943 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
1944 (min_xid & fc_cpu_mask) != 0) {
1945 FC_LPORT_DBG(lp, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
1951 * allocate memory for EM
1953 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
1958 /* adjust em exch xid range for offload */
1959 mp->min_xid = min_xid;
1960 mp->max_xid = max_xid;
1962 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
1967 * Setup per cpu exch pool with entire exchange id range equally
1968 * divided across all cpus. The exch pointers array memory is
1969 * allocated for exch range per pool.
1971 pool_exch_range = (mp->max_xid - mp->min_xid + 1) / (fc_cpu_mask + 1);
1972 mp->pool_max_index = pool_exch_range - 1;
1975 * Allocate and initialize per cpu exch pool
1977 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
1978 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
1981 for_each_possible_cpu(cpu) {
1982 pool = per_cpu_ptr(mp->pool, cpu);
1983 spin_lock_init(&pool->lock);
1984 INIT_LIST_HEAD(&pool->ex_list);
1987 kref_init(&mp->kref);
1988 if (!fc_exch_mgr_add(lp, mp, match)) {
1989 free_percpu(mp->pool);
1994 * Above kref_init() sets mp->kref to 1 and then
1995 * call to fc_exch_mgr_add incremented mp->kref again,
1996 * so adjust that extra increment.
1998 kref_put(&mp->kref, fc_exch_mgr_destroy);
2002 mempool_destroy(mp->ep_pool);
2007 EXPORT_SYMBOL(fc_exch_mgr_alloc);
2009 void fc_exch_mgr_free(struct fc_lport *lport)
2011 struct fc_exch_mgr_anchor *ema, *next;
2013 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
2014 fc_exch_mgr_del(ema);
2016 EXPORT_SYMBOL(fc_exch_mgr_free);
2021 void fc_exch_recv(struct fc_lport *lp, struct fc_frame *fp)
2023 struct fc_frame_header *fh = fc_frame_header_get(fp);
2024 struct fc_exch_mgr_anchor *ema;
2025 u32 f_ctl, found = 0;
2029 if (!lp || lp->state == LPORT_ST_DISABLED) {
2030 FC_LPORT_DBG(lp, "Receiving frames for an lport that "
2031 "has not been initialized correctly\n");
2036 f_ctl = ntoh24(fh->fh_f_ctl);
2037 oxid = ntohs(fh->fh_ox_id);
2038 if (f_ctl & FC_FC_EX_CTX) {
2039 list_for_each_entry(ema, &lp->ema_list, ema_list) {
2040 if ((oxid >= ema->mp->min_xid) &&
2041 (oxid <= ema->mp->max_xid)) {
2048 FC_LPORT_DBG(lp, "Received response for out "
2049 "of range oxid:%hx\n", oxid);
2054 ema = list_entry(lp->ema_list.prev, typeof(*ema), ema_list);
2057 * If frame is marked invalid, just drop it.
2059 switch (fr_eof(fp)) {
2061 if (f_ctl & FC_FC_END_SEQ)
2062 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2065 if (fh->fh_type == FC_TYPE_BLS)
2066 fc_exch_recv_bls(ema->mp, fp);
2067 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2069 fc_exch_recv_seq_resp(ema->mp, fp);
2070 else if (f_ctl & FC_FC_SEQ_CTX)
2071 fc_exch_recv_resp(ema->mp, fp);
2073 fc_exch_recv_req(lp, ema->mp, fp);
2076 FC_LPORT_DBG(lp, "dropping invalid frame (eof %x)", fr_eof(fp));
2080 EXPORT_SYMBOL(fc_exch_recv);
2082 int fc_exch_init(struct fc_lport *lp)
2084 if (!lp->tt.seq_start_next)
2085 lp->tt.seq_start_next = fc_seq_start_next;
2087 if (!lp->tt.exch_seq_send)
2088 lp->tt.exch_seq_send = fc_exch_seq_send;
2090 if (!lp->tt.seq_send)
2091 lp->tt.seq_send = fc_seq_send;
2093 if (!lp->tt.seq_els_rsp_send)
2094 lp->tt.seq_els_rsp_send = fc_seq_els_rsp_send;
2096 if (!lp->tt.exch_done)
2097 lp->tt.exch_done = fc_exch_done;
2099 if (!lp->tt.exch_mgr_reset)
2100 lp->tt.exch_mgr_reset = fc_exch_mgr_reset;
2102 if (!lp->tt.seq_exch_abort)
2103 lp->tt.seq_exch_abort = fc_seq_exch_abort;
2107 EXPORT_SYMBOL(fc_exch_init);
2110 * fc_setup_exch_mgr() - Setup an exchange manager
2112 int fc_setup_exch_mgr()
2114 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2115 0, SLAB_HWCACHE_ALIGN, NULL);
2120 * Initialize fc_cpu_mask and fc_cpu_order. The
2121 * fc_cpu_mask is set for nr_cpu_ids rounded up
2122 * to order of 2's * power and order is stored
2123 * in fc_cpu_order as this is later required in
2124 * mapping between an exch id and exch array index
2125 * in per cpu exch pool.
2127 * This round up is required to align fc_cpu_mask
2128 * to exchange id's lower bits such that all incoming
2129 * frames of an exchange gets delivered to the same
2130 * cpu on which exchange originated by simple bitwise
2131 * AND operation between fc_cpu_mask and exchange id.
2135 while (fc_cpu_mask < nr_cpu_ids) {
2144 void fc_destroy_exch_mgr(void)
2146 kmem_cache_destroy(fc_em_cachep);