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 *);
110 static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp);
113 * Internal implementation notes.
115 * The exchange manager is one by default in libfc but LLD may choose
116 * to have one per CPU. The sequence manager is one per exchange manager
117 * and currently never separated.
119 * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field
120 * assigned by the Sequence Initiator that shall be unique for a specific
121 * D_ID and S_ID pair while the Sequence is open." Note that it isn't
122 * qualified by exchange ID, which one might think it would be.
123 * In practice this limits the number of open sequences and exchanges to 256
124 * per session. For most targets we could treat this limit as per exchange.
126 * The exchange and its sequence are freed when the last sequence is received.
127 * It's possible for the remote port to leave an exchange open without
128 * sending any sequences.
130 * Notes on reference counts:
132 * Exchanges are reference counted and exchange gets freed when the reference
133 * count becomes zero.
136 * Sequences are timed out for E_D_TOV and R_A_TOV.
138 * Sequence event handling:
140 * The following events may occur on initiator sequences:
143 * For now, the whole thing is sent.
145 * This applies only to class F.
146 * The sequence is marked complete.
148 * The upper layer calls fc_exch_done() when done
149 * with exchange and sequence tuple.
150 * RX-inferred completion.
151 * When we receive the next sequence on the same exchange, we can
152 * retire the previous sequence ID. (XXX not implemented).
154 * R_A_TOV frees the sequence ID. If we're waiting for ACK,
155 * E_D_TOV causes abort and calls upper layer response handler
156 * with FC_EX_TIMEOUT error.
162 * The following events may occur on recipient sequences:
165 * Allocate sequence for first frame received.
166 * Hold during receive handler.
167 * Release when final frame received.
168 * Keep status of last N of these for the ELS RES command. XXX TBD.
170 * Deallocate sequence
174 * For now, we neglect conditions where only part of a sequence was
175 * received or transmitted, or where out-of-order receipt is detected.
181 * The EM code run in a per-CPU worker thread.
183 * To protect against concurrency between a worker thread code and timers,
184 * sequence allocation and deallocation must be locked.
185 * - exchange refcnt can be done atomicly without locks.
186 * - sequence allocation must be locked by exch lock.
187 * - If the EM pool lock and ex_lock must be taken at the same time, then the
188 * EM pool lock must be taken before the ex_lock.
192 * opcode names for debugging.
194 static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;
196 #define FC_TABLE_SIZE(x) (sizeof(x) / sizeof(x[0]))
198 static inline const char *fc_exch_name_lookup(unsigned int op, char **table,
199 unsigned int max_index)
201 const char *name = NULL;
210 static const char *fc_exch_rctl_name(unsigned int op)
212 return fc_exch_name_lookup(op, fc_exch_rctl_names,
213 FC_TABLE_SIZE(fc_exch_rctl_names));
217 * Hold an exchange - keep it from being freed.
219 static void fc_exch_hold(struct fc_exch *ep)
221 atomic_inc(&ep->ex_refcnt);
225 * setup fc hdr by initializing few more FC header fields and sof/eof.
226 * Initialized fields by this func:
227 * - fh_ox_id, fh_rx_id, fh_seq_id, fh_seq_cnt
230 static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,
233 struct fc_frame_header *fh = fc_frame_header_get(fp);
236 fr_sof(fp) = ep->class;
238 fr_sof(fp) = fc_sof_normal(ep->class);
240 if (f_ctl & FC_FC_END_SEQ) {
241 fr_eof(fp) = FC_EOF_T;
242 if (fc_sof_needs_ack(ep->class))
243 fr_eof(fp) = FC_EOF_N;
246 * The number of fill bytes to make the length a 4-byte
247 * multiple is the low order 2-bits of the f_ctl.
248 * The fill itself will have been cleared by the frame
250 * After this, the length will be even, as expected by
253 fill = fr_len(fp) & 3;
256 /* TODO, this may be a problem with fragmented skb */
257 skb_put(fp_skb(fp), fill);
258 hton24(fh->fh_f_ctl, f_ctl | fill);
261 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
262 fr_eof(fp) = FC_EOF_N;
266 * Initialize remainig fh fields
267 * from fc_fill_fc_hdr
269 fh->fh_ox_id = htons(ep->oxid);
270 fh->fh_rx_id = htons(ep->rxid);
271 fh->fh_seq_id = ep->seq.id;
272 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);
375 int fc_seq_exch_abort(const struct fc_seq *req_sp, unsigned int timer_msec)
382 ep = fc_seq_exch(req_sp);
384 spin_lock_bh(&ep->ex_lock);
385 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
386 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
387 spin_unlock_bh(&ep->ex_lock);
392 * Send the abort on a new sequence if possible.
394 sp = fc_seq_start_next_locked(&ep->seq);
396 spin_unlock_bh(&ep->ex_lock);
400 ep->esb_stat |= ESB_ST_SEQ_INIT | ESB_ST_ABNORMAL;
402 fc_exch_timer_set_locked(ep, timer_msec);
403 spin_unlock_bh(&ep->ex_lock);
406 * If not logged into the fabric, don't send ABTS but leave
407 * sequence active until next timeout.
413 * Send an abort for the sequence that timed out.
415 fp = fc_frame_alloc(ep->lp, 0);
417 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
418 FC_TYPE_BLS, FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
419 error = fc_seq_send(ep->lp, sp, fp);
426 * Exchange timeout - handle exchange timer expiration.
427 * The timer will have been cancelled before this is called.
429 static void fc_exch_timeout(struct work_struct *work)
431 struct fc_exch *ep = container_of(work, struct fc_exch,
433 struct fc_seq *sp = &ep->seq;
434 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
439 FC_EXCH_DBG(ep, "Exchange timed out\n");
441 spin_lock_bh(&ep->ex_lock);
442 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
445 e_stat = ep->esb_stat;
446 if (e_stat & ESB_ST_COMPLETE) {
447 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
448 spin_unlock_bh(&ep->ex_lock);
449 if (e_stat & ESB_ST_REC_QUAL)
456 if (e_stat & ESB_ST_ABNORMAL)
457 rc = fc_exch_done_locked(ep);
458 spin_unlock_bh(&ep->ex_lock);
462 resp(sp, ERR_PTR(-FC_EX_TIMEOUT), arg);
463 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
467 spin_unlock_bh(&ep->ex_lock);
470 * This release matches the hold taken when the timer was set.
476 * Allocate a sequence.
478 * We don't support multiple originated sequences on the same exchange.
479 * By implication, any previously originated sequence on this exchange
480 * is complete, and we reallocate the same sequence.
482 static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
494 * fc_exch_em_alloc() - allocate an exchange from a specified EM.
495 * @lport: ptr to the local port
496 * @mp: ptr to the exchange manager
498 * Returns pointer to allocated fc_exch with exch lock held.
500 static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
501 struct fc_exch_mgr *mp)
506 struct fc_exch_pool *pool;
508 /* allocate memory for exchange */
509 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);
511 atomic_inc(&mp->stats.no_free_exch);
514 memset(ep, 0, sizeof(*ep));
516 cpu = smp_processor_id();
517 pool = per_cpu_ptr(mp->pool, cpu);
518 spin_lock_bh(&pool->lock);
519 index = pool->next_index;
520 /* allocate new exch from pool */
521 while (fc_exch_ptr_get(pool, index)) {
522 index = index == mp->pool_max_index ? 0 : index + 1;
523 if (index == pool->next_index)
526 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
528 fc_exch_hold(ep); /* hold for exch in mp */
529 spin_lock_init(&ep->ex_lock);
531 * Hold exch lock for caller to prevent fc_exch_reset()
532 * from releasing exch while fc_exch_alloc() caller is
533 * still working on exch.
535 spin_lock_bh(&ep->ex_lock);
537 fc_exch_ptr_set(pool, index, ep);
538 list_add_tail(&ep->ex_list, &pool->ex_list);
539 fc_seq_alloc(ep, ep->seq_id++);
540 pool->total_exches++;
541 spin_unlock_bh(&pool->lock);
546 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
550 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
551 ep->rxid = FC_XID_UNKNOWN;
552 ep->class = mp->class;
553 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
557 spin_unlock_bh(&pool->lock);
558 atomic_inc(&mp->stats.no_free_exch_xid);
559 mempool_free(ep, mp->ep_pool);
564 * fc_exch_alloc() - allocate an exchange.
565 * @lport: ptr to the local port
566 * @fp: ptr to the FC frame
568 * This function walks the list of the exchange manager(EM)
569 * anchors to select a EM for new exchange allocation. The
570 * EM is selected having either a NULL match function pointer
571 * or call to match function returning true.
573 struct fc_exch *fc_exch_alloc(struct fc_lport *lport, struct fc_frame *fp)
575 struct fc_exch_mgr_anchor *ema;
578 list_for_each_entry(ema, &lport->ema_list, ema_list) {
579 if (!ema->match || ema->match(fp)) {
580 ep = fc_exch_em_alloc(lport, ema->mp);
587 EXPORT_SYMBOL(fc_exch_alloc);
590 * Lookup and hold an exchange.
592 static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
594 struct fc_exch_pool *pool;
595 struct fc_exch *ep = NULL;
597 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
598 pool = per_cpu_ptr(mp->pool, xid & fc_cpu_mask);
599 spin_lock_bh(&pool->lock);
600 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
603 WARN_ON(ep->xid != xid);
605 spin_unlock_bh(&pool->lock);
610 void fc_exch_done(struct fc_seq *sp)
612 struct fc_exch *ep = fc_seq_exch(sp);
615 spin_lock_bh(&ep->ex_lock);
616 rc = fc_exch_done_locked(ep);
617 spin_unlock_bh(&ep->ex_lock);
621 EXPORT_SYMBOL(fc_exch_done);
624 * Allocate a new exchange as responder.
625 * Sets the responder ID in the frame header.
627 static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
628 struct fc_exch_mgr *mp,
632 struct fc_frame_header *fh;
634 ep = fc_exch_alloc(lport, fp);
636 ep->class = fc_frame_class(fp);
639 * Set EX_CTX indicating we're responding on this exchange.
641 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
642 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
643 fh = fc_frame_header_get(fp);
644 ep->sid = ntoh24(fh->fh_d_id);
645 ep->did = ntoh24(fh->fh_s_id);
649 * Allocated exchange has placed the XID in the
650 * originator field. Move it to the responder field,
651 * and set the originator XID from the frame.
654 ep->oxid = ntohs(fh->fh_ox_id);
655 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
656 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
657 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
659 fc_exch_hold(ep); /* hold for caller */
660 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
666 * Find a sequence for receive where the other end is originating the sequence.
667 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
668 * on the ep that should be released by the caller.
670 static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
671 struct fc_exch_mgr *mp,
674 struct fc_frame_header *fh = fc_frame_header_get(fp);
675 struct fc_exch *ep = NULL;
676 struct fc_seq *sp = NULL;
677 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
681 f_ctl = ntoh24(fh->fh_f_ctl);
682 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
685 * Lookup or create the exchange if we will be creating the sequence.
687 if (f_ctl & FC_FC_EX_CTX) {
688 xid = ntohs(fh->fh_ox_id); /* we originated exch */
689 ep = fc_exch_find(mp, xid);
691 atomic_inc(&mp->stats.xid_not_found);
692 reject = FC_RJT_OX_ID;
695 if (ep->rxid == FC_XID_UNKNOWN)
696 ep->rxid = ntohs(fh->fh_rx_id);
697 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
698 reject = FC_RJT_OX_ID;
702 xid = ntohs(fh->fh_rx_id); /* we are the responder */
705 * Special case for MDS issuing an ELS TEST with a
707 * XXX take this out once we do the proper reject.
709 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
710 fc_frame_payload_op(fp) == ELS_TEST) {
711 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
712 xid = FC_XID_UNKNOWN;
716 * new sequence - find the exchange
718 ep = fc_exch_find(mp, xid);
719 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
721 atomic_inc(&mp->stats.xid_busy);
722 reject = FC_RJT_RX_ID;
725 ep = fc_exch_resp(lport, mp, fp);
727 reject = FC_RJT_EXCH_EST; /* XXX */
730 xid = ep->xid; /* get our XID */
732 atomic_inc(&mp->stats.xid_not_found);
733 reject = FC_RJT_RX_ID; /* XID not found */
739 * At this point, we have the exchange held.
740 * Find or create the sequence.
742 if (fc_sof_is_init(fr_sof(fp))) {
743 sp = fc_seq_start_next(&ep->seq);
745 reject = FC_RJT_SEQ_XS; /* exchange shortage */
748 sp->id = fh->fh_seq_id;
749 sp->ssb_stat |= SSB_ST_RESP;
752 if (sp->id != fh->fh_seq_id) {
753 atomic_inc(&mp->stats.seq_not_found);
754 reject = FC_RJT_SEQ_ID; /* sequence/exch should exist */
758 WARN_ON(ep != fc_seq_exch(sp));
760 if (f_ctl & FC_FC_SEQ_INIT)
761 ep->esb_stat |= ESB_ST_SEQ_INIT;
767 fc_exch_done(&ep->seq);
768 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
773 * Find the sequence for a frame being received.
774 * We originated the sequence, so it should be found.
775 * We may or may not have originated the exchange.
776 * Does not hold the sequence for the caller.
778 static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
781 struct fc_frame_header *fh = fc_frame_header_get(fp);
783 struct fc_seq *sp = NULL;
787 f_ctl = ntoh24(fh->fh_f_ctl);
788 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
789 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
790 ep = fc_exch_find(mp, xid);
793 if (ep->seq.id == fh->fh_seq_id) {
795 * Save the RX_ID if we didn't previously know it.
798 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
799 ep->rxid == FC_XID_UNKNOWN) {
800 ep->rxid = ntohs(fh->fh_rx_id);
808 * Set addresses for an exchange.
809 * Note this must be done before the first sequence of the exchange is sent.
811 static void fc_exch_set_addr(struct fc_exch *ep,
812 u32 orig_id, u32 resp_id)
815 if (ep->esb_stat & ESB_ST_RESP) {
824 static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
826 struct fc_exch *ep = fc_seq_exch(sp);
828 sp = fc_seq_alloc(ep, ep->seq_id++);
829 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
834 * Allocate a new sequence on the same exchange as the supplied sequence.
835 * This will never return NULL.
837 struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
839 struct fc_exch *ep = fc_seq_exch(sp);
841 spin_lock_bh(&ep->ex_lock);
842 sp = fc_seq_start_next_locked(sp);
843 spin_unlock_bh(&ep->ex_lock);
847 EXPORT_SYMBOL(fc_seq_start_next);
849 int fc_seq_send(struct fc_lport *lp, struct fc_seq *sp, struct fc_frame *fp)
852 struct fc_frame_header *fh = fc_frame_header_get(fp);
856 ep = fc_seq_exch(sp);
857 WARN_ON((ep->esb_stat & ESB_ST_SEQ_INIT) != ESB_ST_SEQ_INIT);
859 f_ctl = ntoh24(fh->fh_f_ctl);
860 fc_exch_setup_hdr(ep, fp, f_ctl);
863 * update sequence count if this frame is carrying
864 * multiple FC frames when sequence offload is enabled
867 if (fr_max_payload(fp))
868 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),
876 error = lp->tt.frame_send(lp, fp);
879 * Update the exchange and sequence flags,
880 * assuming all frames for the sequence have been sent.
881 * We can only be called to send once for each sequence.
883 spin_lock_bh(&ep->ex_lock);
884 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
885 if (f_ctl & (FC_FC_END_SEQ | FC_FC_SEQ_INIT))
886 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
887 spin_unlock_bh(&ep->ex_lock);
890 EXPORT_SYMBOL(fc_seq_send);
892 void fc_seq_els_rsp_send(struct fc_seq *sp, enum fc_els_cmd els_cmd,
893 struct fc_seq_els_data *els_data)
897 fc_seq_ls_rjt(sp, els_data->reason, els_data->explan);
903 fc_exch_els_rrq(sp, els_data->fp);
906 fc_exch_els_rec(sp, els_data->fp);
909 FC_EXCH_DBG(fc_seq_exch(sp), "Invalid ELS CMD:%x\n", els_cmd);
912 EXPORT_SYMBOL(fc_seq_els_rsp_send);
915 * Send a sequence, which is also the last sequence in the exchange.
917 static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
918 enum fc_rctl rctl, enum fc_fh_type fh_type)
921 struct fc_exch *ep = fc_seq_exch(sp);
923 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
925 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
926 fc_seq_send(ep->lp, sp, fp);
930 * Send ACK_1 (or equiv.) indicating we received something.
931 * The frame we're acking is supplied.
933 static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
936 struct fc_frame_header *rx_fh;
937 struct fc_frame_header *fh;
938 struct fc_exch *ep = fc_seq_exch(sp);
939 struct fc_lport *lp = ep->lp;
943 * Don't send ACKs for class 3.
945 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
946 fp = fc_frame_alloc(lp, 0);
950 fh = fc_frame_header_get(fp);
951 fh->fh_r_ctl = FC_RCTL_ACK_1;
952 fh->fh_type = FC_TYPE_BLS;
955 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
956 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
957 * Bits 9-8 are meaningful (retransmitted or unidirectional).
958 * Last ACK uses bits 7-6 (continue sequence),
959 * bits 5-4 are meaningful (what kind of ACK to use).
961 rx_fh = fc_frame_header_get(rx_fp);
962 f_ctl = ntoh24(rx_fh->fh_f_ctl);
963 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
964 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
965 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
966 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
967 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
968 hton24(fh->fh_f_ctl, f_ctl);
970 fc_exch_setup_hdr(ep, fp, f_ctl);
971 fh->fh_seq_id = rx_fh->fh_seq_id;
972 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
973 fh->fh_parm_offset = htonl(1); /* ack single frame */
975 fr_sof(fp) = fr_sof(rx_fp);
976 if (f_ctl & FC_FC_END_SEQ)
977 fr_eof(fp) = FC_EOF_T;
979 fr_eof(fp) = FC_EOF_N;
981 (void) lp->tt.frame_send(lp, fp);
987 * This is for rejecting BA_ABTS only.
989 static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
990 enum fc_ba_rjt_reason reason,
991 enum fc_ba_rjt_explan explan)
994 struct fc_frame_header *rx_fh;
995 struct fc_frame_header *fh;
996 struct fc_ba_rjt *rp;
1001 fp = fc_frame_alloc(lp, sizeof(*rp));
1004 fh = fc_frame_header_get(fp);
1005 rx_fh = fc_frame_header_get(rx_fp);
1007 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1009 rp = fc_frame_payload_get(fp, sizeof(*rp));
1010 rp->br_reason = reason;
1011 rp->br_explan = explan;
1014 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1016 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1017 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1018 fh->fh_ox_id = rx_fh->fh_ox_id;
1019 fh->fh_rx_id = rx_fh->fh_rx_id;
1020 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1021 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1022 fh->fh_type = FC_TYPE_BLS;
1025 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1026 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1027 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1028 * Last ACK uses bits 7-6 (continue sequence),
1029 * bits 5-4 are meaningful (what kind of ACK to use).
1030 * Always set LAST_SEQ, END_SEQ.
1032 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1033 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1034 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1035 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1036 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1037 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1038 f_ctl &= ~FC_FC_FIRST_SEQ;
1039 hton24(fh->fh_f_ctl, f_ctl);
1041 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1042 fr_eof(fp) = FC_EOF_T;
1043 if (fc_sof_needs_ack(fr_sof(fp)))
1044 fr_eof(fp) = FC_EOF_N;
1046 (void) lp->tt.frame_send(lp, fp);
1050 * Handle an incoming ABTS. This would be for target mode usually,
1051 * but could be due to lost FCP transfer ready, confirm or RRQ.
1052 * We always handle this as an exchange abort, ignoring the parameter.
1054 static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1056 struct fc_frame *fp;
1057 struct fc_ba_acc *ap;
1058 struct fc_frame_header *fh;
1063 spin_lock_bh(&ep->ex_lock);
1064 if (ep->esb_stat & ESB_ST_COMPLETE) {
1065 spin_unlock_bh(&ep->ex_lock);
1068 if (!(ep->esb_stat & ESB_ST_REC_QUAL))
1069 fc_exch_hold(ep); /* hold for REC_QUAL */
1070 ep->esb_stat |= ESB_ST_ABNORMAL | ESB_ST_REC_QUAL;
1071 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1073 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1075 spin_unlock_bh(&ep->ex_lock);
1078 fh = fc_frame_header_get(fp);
1079 ap = fc_frame_payload_get(fp, sizeof(*ap));
1080 memset(ap, 0, sizeof(*ap));
1082 ap->ba_high_seq_cnt = htons(0xffff);
1083 if (sp->ssb_stat & SSB_ST_RESP) {
1084 ap->ba_seq_id = sp->id;
1085 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1086 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1087 ap->ba_low_seq_cnt = htons(sp->cnt);
1089 sp = fc_seq_start_next_locked(sp);
1090 spin_unlock_bh(&ep->ex_lock);
1091 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1092 fc_frame_free(rx_fp);
1096 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1098 fc_frame_free(rx_fp);
1102 * Handle receive where the other end is originating the sequence.
1104 static void fc_exch_recv_req(struct fc_lport *lp, struct fc_exch_mgr *mp,
1105 struct fc_frame *fp)
1107 struct fc_frame_header *fh = fc_frame_header_get(fp);
1108 struct fc_seq *sp = NULL;
1109 struct fc_exch *ep = NULL;
1113 enum fc_pf_rjt_reason reject;
1116 reject = fc_seq_lookup_recip(lp, mp, fp);
1117 if (reject == FC_RJT_NONE) {
1118 sp = fr_seq(fp); /* sequence will be held */
1119 ep = fc_seq_exch(sp);
1122 f_ctl = ntoh24(fh->fh_f_ctl);
1123 fc_seq_send_ack(sp, fp);
1126 * Call the receive function.
1128 * The receive function may allocate a new sequence
1129 * over the old one, so we shouldn't change the
1130 * sequence after this.
1132 * The frame will be freed by the receive function.
1133 * If new exch resp handler is valid then call that
1137 ep->resp(sp, fp, ep->arg);
1139 lp->tt.lport_recv(lp, sp, fp);
1140 fc_exch_release(ep); /* release from lookup */
1142 FC_LPORT_DBG(lp, "exch/seq lookup failed: reject %x\n", reject);
1148 * Handle receive where the other end is originating the sequence in
1149 * response to our exchange.
1151 static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1153 struct fc_frame_header *fh = fc_frame_header_get(fp);
1158 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
1162 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1164 atomic_inc(&mp->stats.xid_not_found);
1167 if (ep->esb_stat & ESB_ST_COMPLETE) {
1168 atomic_inc(&mp->stats.xid_not_found);
1171 if (ep->rxid == FC_XID_UNKNOWN)
1172 ep->rxid = ntohs(fh->fh_rx_id);
1173 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1174 atomic_inc(&mp->stats.xid_not_found);
1177 if (ep->did != ntoh24(fh->fh_s_id) &&
1178 ep->did != FC_FID_FLOGI) {
1179 atomic_inc(&mp->stats.xid_not_found);
1183 if (fc_sof_is_init(sof)) {
1184 sp = fc_seq_start_next(&ep->seq);
1185 sp->id = fh->fh_seq_id;
1186 sp->ssb_stat |= SSB_ST_RESP;
1189 if (sp->id != fh->fh_seq_id) {
1190 atomic_inc(&mp->stats.seq_not_found);
1194 f_ctl = ntoh24(fh->fh_f_ctl);
1196 if (f_ctl & FC_FC_SEQ_INIT)
1197 ep->esb_stat |= ESB_ST_SEQ_INIT;
1199 if (fc_sof_needs_ack(sof))
1200 fc_seq_send_ack(sp, fp);
1202 ex_resp_arg = ep->arg;
1204 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1205 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1206 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1207 spin_lock_bh(&ep->ex_lock);
1208 rc = fc_exch_done_locked(ep);
1209 WARN_ON(fc_seq_exch(sp) != ep);
1210 spin_unlock_bh(&ep->ex_lock);
1216 * Call the receive function.
1217 * The sequence is held (has a refcnt) for us,
1218 * but not for the receive function.
1220 * The receive function may allocate a new sequence
1221 * over the old one, so we shouldn't change the
1222 * sequence after this.
1224 * The frame will be freed by the receive function.
1225 * If new exch resp handler is valid then call that
1229 resp(sp, fp, ex_resp_arg);
1232 fc_exch_release(ep);
1235 fc_exch_release(ep);
1241 * Handle receive for a sequence where other end is responding to our sequence.
1243 static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1247 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1250 atomic_inc(&mp->stats.xid_not_found);
1252 atomic_inc(&mp->stats.non_bls_resp);
1258 * Handle the response to an ABTS for exchange or sequence.
1259 * This can be BA_ACC or BA_RJT.
1261 static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1263 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
1265 struct fc_frame_header *fh;
1266 struct fc_ba_acc *ap;
1270 int rc = 1, has_rec = 0;
1272 fh = fc_frame_header_get(fp);
1273 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1274 fc_exch_rctl_name(fh->fh_r_ctl));
1276 if (cancel_delayed_work_sync(&ep->timeout_work))
1277 fc_exch_release(ep); /* release from pending timer hold */
1279 spin_lock_bh(&ep->ex_lock);
1280 switch (fh->fh_r_ctl) {
1281 case FC_RCTL_BA_ACC:
1282 ap = fc_frame_payload_get(fp, sizeof(*ap));
1287 * Decide whether to establish a Recovery Qualifier.
1288 * We do this if there is a non-empty SEQ_CNT range and
1289 * SEQ_ID is the same as the one we aborted.
1291 low = ntohs(ap->ba_low_seq_cnt);
1292 high = ntohs(ap->ba_high_seq_cnt);
1293 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1294 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1295 ap->ba_seq_id == ep->seq_id) && low != high) {
1296 ep->esb_stat |= ESB_ST_REC_QUAL;
1297 fc_exch_hold(ep); /* hold for recovery qualifier */
1301 case FC_RCTL_BA_RJT:
1308 ex_resp_arg = ep->arg;
1310 /* do we need to do some other checks here. Can we reuse more of
1311 * fc_exch_recv_seq_resp
1315 * do we want to check END_SEQ as well as LAST_SEQ here?
1317 if (ep->fh_type != FC_TYPE_FCP &&
1318 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1319 rc = fc_exch_done_locked(ep);
1320 spin_unlock_bh(&ep->ex_lock);
1325 resp(sp, fp, ex_resp_arg);
1330 fc_exch_timer_set(ep, ep->r_a_tov);
1335 * Receive BLS sequence.
1336 * This is always a sequence initiated by the remote side.
1337 * We may be either the originator or recipient of the exchange.
1339 static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1341 struct fc_frame_header *fh;
1345 fh = fc_frame_header_get(fp);
1346 f_ctl = ntoh24(fh->fh_f_ctl);
1349 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1350 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1351 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1352 spin_lock_bh(&ep->ex_lock);
1353 ep->esb_stat |= ESB_ST_SEQ_INIT;
1354 spin_unlock_bh(&ep->ex_lock);
1356 if (f_ctl & FC_FC_SEQ_CTX) {
1358 * A response to a sequence we initiated.
1359 * This should only be ACKs for class 2 or F.
1361 switch (fh->fh_r_ctl) {
1366 FC_EXCH_DBG(ep, "BLS rctl %x - %s received",
1368 fc_exch_rctl_name(fh->fh_r_ctl));
1373 switch (fh->fh_r_ctl) {
1374 case FC_RCTL_BA_RJT:
1375 case FC_RCTL_BA_ACC:
1377 fc_exch_abts_resp(ep, fp);
1381 case FC_RCTL_BA_ABTS:
1382 fc_exch_recv_abts(ep, fp);
1384 default: /* ignore junk */
1390 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1394 * Accept sequence with LS_ACC.
1395 * If this fails due to allocation or transmit congestion, assume the
1396 * originator will repeat the sequence.
1398 static void fc_seq_ls_acc(struct fc_seq *req_sp)
1401 struct fc_els_ls_acc *acc;
1402 struct fc_frame *fp;
1404 sp = fc_seq_start_next(req_sp);
1405 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*acc));
1407 acc = fc_frame_payload_get(fp, sizeof(*acc));
1408 memset(acc, 0, sizeof(*acc));
1409 acc->la_cmd = ELS_LS_ACC;
1410 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1415 * Reject sequence with ELS LS_RJT.
1416 * If this fails due to allocation or transmit congestion, assume the
1417 * originator will repeat the sequence.
1419 static void fc_seq_ls_rjt(struct fc_seq *req_sp, enum fc_els_rjt_reason reason,
1420 enum fc_els_rjt_explan explan)
1423 struct fc_els_ls_rjt *rjt;
1424 struct fc_frame *fp;
1426 sp = fc_seq_start_next(req_sp);
1427 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*rjt));
1429 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1430 memset(rjt, 0, sizeof(*rjt));
1431 rjt->er_cmd = ELS_LS_RJT;
1432 rjt->er_reason = reason;
1433 rjt->er_explan = explan;
1434 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1438 static void fc_exch_reset(struct fc_exch *ep)
1441 void (*resp)(struct fc_seq *, struct fc_frame *, void *);
1445 spin_lock_bh(&ep->ex_lock);
1446 ep->state |= FC_EX_RST_CLEANUP;
1448 * we really want to call del_timer_sync, but cannot due
1449 * to the lport calling with the lport lock held (some resp
1450 * functions can also grab the lport lock which could cause
1453 if (cancel_delayed_work(&ep->timeout_work))
1454 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
1457 if (ep->esb_stat & ESB_ST_REC_QUAL)
1458 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1459 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1462 rc = fc_exch_done_locked(ep);
1463 spin_unlock_bh(&ep->ex_lock);
1468 resp(sp, ERR_PTR(-FC_EX_CLOSED), arg);
1472 * fc_exch_pool_reset() - Resets an per cpu exches pool.
1473 * @lport: ptr to the local port
1474 * @pool: ptr to the per cpu exches pool
1475 * @sid: source FC ID
1476 * @did: destination FC ID
1478 * Resets an per cpu exches pool, releasing its all sequences
1479 * and exchanges. If sid is non-zero, then reset only exchanges
1480 * we sourced from that FID. If did is non-zero, reset only
1481 * exchanges destined to that FID.
1483 static void fc_exch_pool_reset(struct fc_lport *lport,
1484 struct fc_exch_pool *pool,
1488 struct fc_exch *next;
1490 spin_lock_bh(&pool->lock);
1492 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1493 if ((lport == ep->lp) &&
1494 (sid == 0 || sid == ep->sid) &&
1495 (did == 0 || did == ep->did)) {
1497 spin_unlock_bh(&pool->lock);
1501 fc_exch_release(ep);
1502 spin_lock_bh(&pool->lock);
1505 * must restart loop incase while lock
1506 * was down multiple eps were released.
1511 spin_unlock_bh(&pool->lock);
1515 * fc_exch_mgr_reset() - Resets all EMs of a lport
1516 * @lport: ptr to the local port
1517 * @sid: source FC ID
1518 * @did: destination FC ID
1520 * Reset all EMs of a lport, releasing its all sequences and
1521 * exchanges. If sid is non-zero, then reset only exchanges
1522 * we sourced from that FID. If did is non-zero, reset only
1523 * exchanges destined to that FID.
1525 void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1527 struct fc_exch_mgr_anchor *ema;
1530 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1531 for_each_possible_cpu(cpu)
1532 fc_exch_pool_reset(lport,
1533 per_cpu_ptr(ema->mp->pool, cpu),
1537 EXPORT_SYMBOL(fc_exch_mgr_reset);
1540 * Handle incoming ELS REC - Read Exchange Concise.
1541 * Note that the requesting port may be different than the S_ID in the request.
1543 static void fc_exch_els_rec(struct fc_seq *sp, struct fc_frame *rfp)
1545 struct fc_frame *fp;
1547 struct fc_exch_mgr *em;
1548 struct fc_els_rec *rp;
1549 struct fc_els_rec_acc *acc;
1550 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
1551 enum fc_els_rjt_explan explan;
1556 rp = fc_frame_payload_get(rfp, sizeof(*rp));
1557 explan = ELS_EXPL_INV_LEN;
1560 sid = ntoh24(rp->rec_s_id);
1561 rxid = ntohs(rp->rec_rx_id);
1562 oxid = ntohs(rp->rec_ox_id);
1565 * Currently it's hard to find the local S_ID from the exchange
1566 * manager. This will eventually be fixed, but for now it's easier
1567 * to lookup the subject exchange twice, once as if we were
1568 * the initiator, and then again if we weren't.
1570 em = fc_seq_exch(sp)->em;
1571 ep = fc_exch_find(em, oxid);
1572 explan = ELS_EXPL_OXID_RXID;
1573 if (ep && ep->oid == sid) {
1574 if (ep->rxid != FC_XID_UNKNOWN &&
1575 rxid != FC_XID_UNKNOWN &&
1580 fc_exch_release(ep);
1582 if (rxid != FC_XID_UNKNOWN)
1583 ep = fc_exch_find(em, rxid);
1588 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*acc));
1593 sp = fc_seq_start_next(sp);
1594 acc = fc_frame_payload_get(fp, sizeof(*acc));
1595 memset(acc, 0, sizeof(*acc));
1596 acc->reca_cmd = ELS_LS_ACC;
1597 acc->reca_ox_id = rp->rec_ox_id;
1598 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
1599 acc->reca_rx_id = htons(ep->rxid);
1600 if (ep->sid == ep->oid)
1601 hton24(acc->reca_rfid, ep->did);
1603 hton24(acc->reca_rfid, ep->sid);
1604 acc->reca_fc4value = htonl(ep->seq.rec_data);
1605 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
1608 sp = fc_seq_start_next(sp);
1609 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1611 fc_exch_release(ep);
1616 fc_exch_release(ep);
1618 fc_seq_ls_rjt(sp, reason, explan);
1623 * Handle response from RRQ.
1624 * Not much to do here, really.
1625 * Should report errors.
1627 * TODO: fix error handler.
1629 static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
1631 struct fc_exch *aborted_ep = arg;
1635 int err = PTR_ERR(fp);
1637 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
1639 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
1640 "frame error %d\n", err);
1644 op = fc_frame_payload_op(fp);
1649 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ");
1654 FC_EXCH_DBG(aborted_ep, "unexpected response op %x "
1660 fc_exch_done(&aborted_ep->seq);
1661 /* drop hold for rec qual */
1662 fc_exch_release(aborted_ep);
1666 * Send ELS RRQ - Reinstate Recovery Qualifier.
1667 * This tells the remote port to stop blocking the use of
1668 * the exchange and the seq_cnt range.
1670 static void fc_exch_rrq(struct fc_exch *ep)
1672 struct fc_lport *lp;
1673 struct fc_els_rrq *rrq;
1674 struct fc_frame *fp;
1679 fp = fc_frame_alloc(lp, sizeof(*rrq));
1683 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
1684 memset(rrq, 0, sizeof(*rrq));
1685 rrq->rrq_cmd = ELS_RRQ;
1686 hton24(rrq->rrq_s_id, ep->sid);
1687 rrq->rrq_ox_id = htons(ep->oxid);
1688 rrq->rrq_rx_id = htons(ep->rxid);
1691 if (ep->esb_stat & ESB_ST_RESP)
1694 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
1695 fc_host_port_id(lp->host), FC_TYPE_ELS,
1696 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1698 if (fc_exch_seq_send(lp, fp, fc_exch_rrq_resp, NULL, ep, lp->e_d_tov))
1702 spin_lock_bh(&ep->ex_lock);
1703 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
1704 spin_unlock_bh(&ep->ex_lock);
1705 /* drop hold for rec qual */
1706 fc_exch_release(ep);
1709 ep->esb_stat |= ESB_ST_REC_QUAL;
1710 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1711 spin_unlock_bh(&ep->ex_lock);
1716 * Handle incoming ELS RRQ - Reset Recovery Qualifier.
1718 static void fc_exch_els_rrq(struct fc_seq *sp, struct fc_frame *fp)
1720 struct fc_exch *ep = NULL; /* request or subject exchange */
1721 struct fc_els_rrq *rp;
1724 enum fc_els_rjt_explan explan;
1726 rp = fc_frame_payload_get(fp, sizeof(*rp));
1727 explan = ELS_EXPL_INV_LEN;
1732 * lookup subject exchange.
1734 ep = fc_seq_exch(sp);
1735 sid = ntoh24(rp->rrq_s_id); /* subject source */
1736 xid = ep->did == sid ? ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
1737 ep = fc_exch_find(ep->em, xid);
1739 explan = ELS_EXPL_OXID_RXID;
1742 spin_lock_bh(&ep->ex_lock);
1743 if (ep->oxid != ntohs(rp->rrq_ox_id))
1745 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
1746 ep->rxid != FC_XID_UNKNOWN)
1748 explan = ELS_EXPL_SID;
1753 * Clear Recovery Qualifier state, and cancel timer if complete.
1755 if (ep->esb_stat & ESB_ST_REC_QUAL) {
1756 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1757 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
1759 if (ep->esb_stat & ESB_ST_COMPLETE) {
1760 if (cancel_delayed_work(&ep->timeout_work))
1761 atomic_dec(&ep->ex_refcnt); /* drop timer hold */
1764 spin_unlock_bh(&ep->ex_lock);
1773 spin_unlock_bh(&ep->ex_lock);
1775 fc_seq_ls_rjt(sp, ELS_RJT_LOGIC, explan);
1779 fc_exch_release(ep); /* drop hold from fc_exch_find */
1782 struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
1783 struct fc_exch_mgr *mp,
1784 bool (*match)(struct fc_frame *))
1786 struct fc_exch_mgr_anchor *ema;
1788 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
1794 /* add EM anchor to EM anchors list */
1795 list_add_tail(&ema->ema_list, &lport->ema_list);
1796 kref_get(&mp->kref);
1799 EXPORT_SYMBOL(fc_exch_mgr_add);
1801 static void fc_exch_mgr_destroy(struct kref *kref)
1803 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
1805 mempool_destroy(mp->ep_pool);
1806 free_percpu(mp->pool);
1810 void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
1812 /* remove EM anchor from EM anchors list */
1813 list_del(&ema->ema_list);
1814 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
1817 EXPORT_SYMBOL(fc_exch_mgr_del);
1819 struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lp,
1820 enum fc_class class,
1821 u16 min_xid, u16 max_xid,
1822 bool (*match)(struct fc_frame *))
1824 struct fc_exch_mgr *mp;
1825 u16 pool_exch_range;
1828 struct fc_exch_pool *pool;
1830 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
1831 (min_xid & fc_cpu_mask) != 0) {
1832 FC_LPORT_DBG(lp, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
1838 * allocate memory for EM
1840 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
1845 /* adjust em exch xid range for offload */
1846 mp->min_xid = min_xid;
1847 mp->max_xid = max_xid;
1849 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
1854 * Setup per cpu exch pool with entire exchange id range equally
1855 * divided across all cpus. The exch pointers array memory is
1856 * allocated for exch range per pool.
1858 pool_exch_range = (mp->max_xid - mp->min_xid + 1) / (fc_cpu_mask + 1);
1859 mp->pool_max_index = pool_exch_range - 1;
1862 * Allocate and initialize per cpu exch pool
1864 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
1865 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
1868 for_each_possible_cpu(cpu) {
1869 pool = per_cpu_ptr(mp->pool, cpu);
1870 spin_lock_init(&pool->lock);
1871 INIT_LIST_HEAD(&pool->ex_list);
1874 kref_init(&mp->kref);
1875 if (!fc_exch_mgr_add(lp, mp, match)) {
1876 free_percpu(mp->pool);
1881 * Above kref_init() sets mp->kref to 1 and then
1882 * call to fc_exch_mgr_add incremented mp->kref again,
1883 * so adjust that extra increment.
1885 kref_put(&mp->kref, fc_exch_mgr_destroy);
1889 mempool_destroy(mp->ep_pool);
1894 EXPORT_SYMBOL(fc_exch_mgr_alloc);
1896 void fc_exch_mgr_free(struct fc_lport *lport)
1898 struct fc_exch_mgr_anchor *ema, *next;
1900 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
1901 fc_exch_mgr_del(ema);
1903 EXPORT_SYMBOL(fc_exch_mgr_free);
1906 struct fc_seq *fc_exch_seq_send(struct fc_lport *lp,
1907 struct fc_frame *fp,
1908 void (*resp)(struct fc_seq *,
1909 struct fc_frame *fp,
1911 void (*destructor)(struct fc_seq *, void *),
1912 void *arg, u32 timer_msec)
1915 struct fc_seq *sp = NULL;
1916 struct fc_frame_header *fh;
1919 ep = fc_exch_alloc(lp, fp);
1924 ep->esb_stat |= ESB_ST_SEQ_INIT;
1925 fh = fc_frame_header_get(fp);
1926 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
1928 ep->destructor = destructor;
1930 ep->r_a_tov = FC_DEF_R_A_TOV;
1934 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
1935 ep->f_ctl = ntoh24(fh->fh_f_ctl);
1936 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
1939 if (ep->xid <= lp->lro_xid)
1940 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
1942 if (unlikely(lp->tt.frame_send(lp, fp)))
1946 fc_exch_timer_set_locked(ep, timer_msec);
1947 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
1949 if (ep->f_ctl & FC_FC_SEQ_INIT)
1950 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
1951 spin_unlock_bh(&ep->ex_lock);
1954 rc = fc_exch_done_locked(ep);
1955 spin_unlock_bh(&ep->ex_lock);
1960 EXPORT_SYMBOL(fc_exch_seq_send);
1965 void fc_exch_recv(struct fc_lport *lp, struct fc_frame *fp)
1967 struct fc_frame_header *fh = fc_frame_header_get(fp);
1968 struct fc_exch_mgr_anchor *ema;
1969 u32 f_ctl, found = 0;
1973 if (!lp || lp->state == LPORT_ST_DISABLED) {
1974 FC_LPORT_DBG(lp, "Receiving frames for an lport that "
1975 "has not been initialized correctly\n");
1980 f_ctl = ntoh24(fh->fh_f_ctl);
1981 oxid = ntohs(fh->fh_ox_id);
1982 if (f_ctl & FC_FC_EX_CTX) {
1983 list_for_each_entry(ema, &lp->ema_list, ema_list) {
1984 if ((oxid >= ema->mp->min_xid) &&
1985 (oxid <= ema->mp->max_xid)) {
1992 FC_LPORT_DBG(lp, "Received response for out "
1993 "of range oxid:%hx\n", oxid);
1998 ema = list_entry(lp->ema_list.prev, typeof(*ema), ema_list);
2001 * If frame is marked invalid, just drop it.
2003 switch (fr_eof(fp)) {
2005 if (f_ctl & FC_FC_END_SEQ)
2006 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2009 if (fh->fh_type == FC_TYPE_BLS)
2010 fc_exch_recv_bls(ema->mp, fp);
2011 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2013 fc_exch_recv_seq_resp(ema->mp, fp);
2014 else if (f_ctl & FC_FC_SEQ_CTX)
2015 fc_exch_recv_resp(ema->mp, fp);
2017 fc_exch_recv_req(lp, ema->mp, fp);
2020 FC_LPORT_DBG(lp, "dropping invalid frame (eof %x)", fr_eof(fp));
2024 EXPORT_SYMBOL(fc_exch_recv);
2026 int fc_exch_init(struct fc_lport *lp)
2028 if (!lp->tt.seq_start_next)
2029 lp->tt.seq_start_next = fc_seq_start_next;
2031 if (!lp->tt.exch_seq_send)
2032 lp->tt.exch_seq_send = fc_exch_seq_send;
2034 if (!lp->tt.seq_send)
2035 lp->tt.seq_send = fc_seq_send;
2037 if (!lp->tt.seq_els_rsp_send)
2038 lp->tt.seq_els_rsp_send = fc_seq_els_rsp_send;
2040 if (!lp->tt.exch_done)
2041 lp->tt.exch_done = fc_exch_done;
2043 if (!lp->tt.exch_mgr_reset)
2044 lp->tt.exch_mgr_reset = fc_exch_mgr_reset;
2046 if (!lp->tt.seq_exch_abort)
2047 lp->tt.seq_exch_abort = fc_seq_exch_abort;
2051 EXPORT_SYMBOL(fc_exch_init);
2054 * fc_setup_exch_mgr() - Setup an exchange manager
2056 int fc_setup_exch_mgr()
2058 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2059 0, SLAB_HWCACHE_ALIGN, NULL);
2064 * Initialize fc_cpu_mask and fc_cpu_order. The
2065 * fc_cpu_mask is set for nr_cpu_ids rounded up
2066 * to order of 2's * power and order is stored
2067 * in fc_cpu_order as this is later required in
2068 * mapping between an exch id and exch array index
2069 * in per cpu exch pool.
2071 * This round up is required to align fc_cpu_mask
2072 * to exchange id's lower bits such that all incoming
2073 * frames of an exchange gets delivered to the same
2074 * cpu on which exchange originated by simple bitwise
2075 * AND operation between fc_cpu_mask and exchange id.
2079 while (fc_cpu_mask < nr_cpu_ids) {
2088 void fc_destroy_exch_mgr(void)
2090 kmem_cache_destroy(fc_em_cachep);