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/slab.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 */
41 struct workqueue_struct *fc_exch_workqueue;
44 * Structure and function definitions for managing Fibre Channel Exchanges
47 * The three primary structures used here are fc_exch_mgr, fc_exch, and fc_seq.
49 * fc_exch_mgr holds the exchange state for an N port
51 * fc_exch holds state for one exchange and links to its active sequence.
53 * fc_seq holds the state for an individual sequence.
57 * struct fc_exch_pool - Per cpu exchange pool
58 * @next_index: Next possible free exchange index
59 * @total_exches: Total allocated exchanges
60 * @lock: Exch pool lock
61 * @ex_list: List of exchanges
63 * This structure manages per cpu exchanges in array of exchange pointers.
64 * This array is allocated followed by struct fc_exch_pool memory for
65 * assigned range of exchanges to per cpu pool.
71 struct list_head ex_list;
75 * struct fc_exch_mgr - The Exchange Manager (EM).
76 * @class: Default class for new sequences
77 * @kref: Reference counter
78 * @min_xid: Minimum exchange ID
79 * @max_xid: Maximum exchange ID
80 * @ep_pool: Reserved exchange pointers
81 * @pool_max_index: Max exch array index in exch pool
82 * @pool: Per cpu exch pool
83 * @stats: Statistics structure
85 * This structure is the center for creating exchanges and sequences.
86 * It manages the allocation of exchange IDs.
95 struct fc_exch_pool *pool;
98 * currently exchange mgr stats are updated but not used.
99 * either stats can be expose via sysfs or remove them
100 * all together if not used XXX
103 atomic_t no_free_exch;
104 atomic_t no_free_exch_xid;
105 atomic_t xid_not_found;
107 atomic_t seq_not_found;
108 atomic_t non_bls_resp;
111 #define fc_seq_exch(sp) container_of(sp, struct fc_exch, seq)
114 * struct fc_exch_mgr_anchor - primary structure for list of EMs
115 * @ema_list: Exchange Manager Anchor list
116 * @mp: Exchange Manager associated with this anchor
117 * @match: Routine to determine if this anchor's EM should be used
119 * When walking the list of anchors the match routine will be called
120 * for each anchor to determine if that EM should be used. The last
121 * anchor in the list will always match to handle any exchanges not
122 * handled by other EMs. The non-default EMs would be added to the
123 * anchor list by HW that provides FCoE offloads.
125 struct fc_exch_mgr_anchor {
126 struct list_head ema_list;
127 struct fc_exch_mgr *mp;
128 bool (*match)(struct fc_frame *);
131 static void fc_exch_rrq(struct fc_exch *);
132 static void fc_seq_ls_acc(struct fc_seq *);
133 static void fc_seq_ls_rjt(struct fc_seq *, enum fc_els_rjt_reason,
134 enum fc_els_rjt_explan);
135 static void fc_exch_els_rec(struct fc_seq *, struct fc_frame *);
136 static void fc_exch_els_rrq(struct fc_seq *, struct fc_frame *);
139 * Internal implementation notes.
141 * The exchange manager is one by default in libfc but LLD may choose
142 * to have one per CPU. The sequence manager is one per exchange manager
143 * and currently never separated.
145 * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field
146 * assigned by the Sequence Initiator that shall be unique for a specific
147 * D_ID and S_ID pair while the Sequence is open." Note that it isn't
148 * qualified by exchange ID, which one might think it would be.
149 * In practice this limits the number of open sequences and exchanges to 256
150 * per session. For most targets we could treat this limit as per exchange.
152 * The exchange and its sequence are freed when the last sequence is received.
153 * It's possible for the remote port to leave an exchange open without
154 * sending any sequences.
156 * Notes on reference counts:
158 * Exchanges are reference counted and exchange gets freed when the reference
159 * count becomes zero.
162 * Sequences are timed out for E_D_TOV and R_A_TOV.
164 * Sequence event handling:
166 * The following events may occur on initiator sequences:
169 * For now, the whole thing is sent.
171 * This applies only to class F.
172 * The sequence is marked complete.
174 * The upper layer calls fc_exch_done() when done
175 * with exchange and sequence tuple.
176 * RX-inferred completion.
177 * When we receive the next sequence on the same exchange, we can
178 * retire the previous sequence ID. (XXX not implemented).
180 * R_A_TOV frees the sequence ID. If we're waiting for ACK,
181 * E_D_TOV causes abort and calls upper layer response handler
182 * with FC_EX_TIMEOUT error.
188 * The following events may occur on recipient sequences:
191 * Allocate sequence for first frame received.
192 * Hold during receive handler.
193 * Release when final frame received.
194 * Keep status of last N of these for the ELS RES command. XXX TBD.
196 * Deallocate sequence
200 * For now, we neglect conditions where only part of a sequence was
201 * received or transmitted, or where out-of-order receipt is detected.
207 * The EM code run in a per-CPU worker thread.
209 * To protect against concurrency between a worker thread code and timers,
210 * sequence allocation and deallocation must be locked.
211 * - exchange refcnt can be done atomicly without locks.
212 * - sequence allocation must be locked by exch lock.
213 * - If the EM pool lock and ex_lock must be taken at the same time, then the
214 * EM pool lock must be taken before the ex_lock.
218 * opcode names for debugging.
220 static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;
222 #define FC_TABLE_SIZE(x) (sizeof(x) / sizeof(x[0]))
225 * fc_exch_name_lookup() - Lookup name by opcode
226 * @op: Opcode to be looked up
227 * @table: Opcode/name table
228 * @max_index: Index not to be exceeded
230 * This routine is used to determine a human-readable string identifying
233 static inline const char *fc_exch_name_lookup(unsigned int op, char **table,
234 unsigned int max_index)
236 const char *name = NULL;
246 * fc_exch_rctl_name() - Wrapper routine for fc_exch_name_lookup()
247 * @op: The opcode to be looked up
249 static const char *fc_exch_rctl_name(unsigned int op)
251 return fc_exch_name_lookup(op, fc_exch_rctl_names,
252 FC_TABLE_SIZE(fc_exch_rctl_names));
256 * fc_exch_hold() - Increment an exchange's reference count
257 * @ep: Echange to be held
259 static inline void fc_exch_hold(struct fc_exch *ep)
261 atomic_inc(&ep->ex_refcnt);
265 * fc_exch_setup_hdr() - Initialize a FC header by initializing some fields
266 * and determine SOF and EOF.
267 * @ep: The exchange to that will use the header
268 * @fp: The frame whose header is to be modified
269 * @f_ctl: F_CTL bits that will be used for the frame header
271 * The fields initialized by this routine are: fh_ox_id, fh_rx_id,
272 * fh_seq_id, fh_seq_cnt and the SOF and EOF.
274 static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,
277 struct fc_frame_header *fh = fc_frame_header_get(fp);
280 fr_sof(fp) = ep->class;
282 fr_sof(fp) = fc_sof_normal(ep->class);
284 if (f_ctl & FC_FC_END_SEQ) {
285 fr_eof(fp) = FC_EOF_T;
286 if (fc_sof_needs_ack(ep->class))
287 fr_eof(fp) = FC_EOF_N;
290 * The number of fill bytes to make the length a 4-byte
291 * multiple is the low order 2-bits of the f_ctl.
292 * The fill itself will have been cleared by the frame
294 * After this, the length will be even, as expected by
297 fill = fr_len(fp) & 3;
300 /* TODO, this may be a problem with fragmented skb */
301 skb_put(fp_skb(fp), fill);
302 hton24(fh->fh_f_ctl, f_ctl | fill);
305 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
306 fr_eof(fp) = FC_EOF_N;
310 * Initialize remainig fh fields
311 * from fc_fill_fc_hdr
313 fh->fh_ox_id = htons(ep->oxid);
314 fh->fh_rx_id = htons(ep->rxid);
315 fh->fh_seq_id = ep->seq.id;
316 fh->fh_seq_cnt = htons(ep->seq.cnt);
320 * fc_exch_release() - Decrement an exchange's reference count
321 * @ep: Exchange to be released
323 * If the reference count reaches zero and the exchange is complete,
326 static void fc_exch_release(struct fc_exch *ep)
328 struct fc_exch_mgr *mp;
330 if (atomic_dec_and_test(&ep->ex_refcnt)) {
333 ep->destructor(&ep->seq, ep->arg);
334 WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));
335 mempool_free(ep, mp->ep_pool);
340 * fc_exch_done_locked() - Complete an exchange with the exchange lock held
341 * @ep: The exchange that is complete
343 static int fc_exch_done_locked(struct fc_exch *ep)
348 * We must check for completion in case there are two threads
349 * tyring to complete this. But the rrq code will reuse the
350 * ep, and in that case we only clear the resp and set it as
351 * complete, so it can be reused by the timer to send the rrq.
354 if (ep->state & FC_EX_DONE)
356 ep->esb_stat |= ESB_ST_COMPLETE;
358 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
359 ep->state |= FC_EX_DONE;
360 if (cancel_delayed_work(&ep->timeout_work))
361 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
368 * fc_exch_ptr_get() - Return an exchange from an exchange pool
369 * @pool: Exchange Pool to get an exchange from
370 * @index: Index of the exchange within the pool
372 * Use the index to get an exchange from within an exchange pool. exches
373 * will point to an array of exchange pointers. The index will select
374 * the exchange within the array.
376 static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,
379 struct fc_exch **exches = (struct fc_exch **)(pool + 1);
380 return exches[index];
384 * fc_exch_ptr_set() - Assign an exchange to a slot in an exchange pool
385 * @pool: The pool to assign the exchange to
386 * @index: The index in the pool where the exchange will be assigned
387 * @ep: The exchange to assign to the pool
389 static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
392 ((struct fc_exch **)(pool + 1))[index] = ep;
396 * fc_exch_delete() - Delete an exchange
397 * @ep: The exchange to be deleted
399 static void fc_exch_delete(struct fc_exch *ep)
401 struct fc_exch_pool *pool;
404 spin_lock_bh(&pool->lock);
405 WARN_ON(pool->total_exches <= 0);
406 pool->total_exches--;
407 fc_exch_ptr_set(pool, (ep->xid - ep->em->min_xid) >> fc_cpu_order,
409 list_del(&ep->ex_list);
410 spin_unlock_bh(&pool->lock);
411 fc_exch_release(ep); /* drop hold for exch in mp */
415 * fc_exch_timer_set_locked() - Start a timer for an exchange w/ the
416 * the exchange lock held
417 * @ep: The exchange whose timer will start
418 * @timer_msec: The timeout period
420 * Used for upper level protocols to time out the exchange.
421 * The timer is cancelled when it fires or when the exchange completes.
423 static inline void fc_exch_timer_set_locked(struct fc_exch *ep,
424 unsigned int timer_msec)
426 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
429 FC_EXCH_DBG(ep, "Exchange timer armed\n");
431 if (queue_delayed_work(fc_exch_workqueue, &ep->timeout_work,
432 msecs_to_jiffies(timer_msec)))
433 fc_exch_hold(ep); /* hold for timer */
437 * fc_exch_timer_set() - Lock the exchange and set the timer
438 * @ep: The exchange whose timer will start
439 * @timer_msec: The timeout period
441 static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec)
443 spin_lock_bh(&ep->ex_lock);
444 fc_exch_timer_set_locked(ep, timer_msec);
445 spin_unlock_bh(&ep->ex_lock);
449 * fc_seq_send() - Send a frame using existing sequence/exchange pair
450 * @lport: The local port that the exchange will be sent on
451 * @sp: The sequence to be sent
452 * @fp: The frame to be sent on the exchange
454 static int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp,
458 struct fc_frame_header *fh = fc_frame_header_get(fp);
462 ep = fc_seq_exch(sp);
463 WARN_ON((ep->esb_stat & ESB_ST_SEQ_INIT) != ESB_ST_SEQ_INIT);
465 f_ctl = ntoh24(fh->fh_f_ctl);
466 fc_exch_setup_hdr(ep, fp, f_ctl);
469 * update sequence count if this frame is carrying
470 * multiple FC frames when sequence offload is enabled
473 if (fr_max_payload(fp))
474 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),
482 error = lport->tt.frame_send(lport, fp);
485 * Update the exchange and sequence flags,
486 * assuming all frames for the sequence have been sent.
487 * We can only be called to send once for each sequence.
489 spin_lock_bh(&ep->ex_lock);
490 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
491 if (f_ctl & FC_FC_SEQ_INIT)
492 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
493 spin_unlock_bh(&ep->ex_lock);
498 * fc_seq_alloc() - Allocate a sequence for a given exchange
499 * @ep: The exchange to allocate a new sequence for
500 * @seq_id: The sequence ID to be used
502 * We don't support multiple originated sequences on the same exchange.
503 * By implication, any previously originated sequence on this exchange
504 * is complete, and we reallocate the same sequence.
506 static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
518 * fc_seq_start_next_locked() - Allocate a new sequence on the same
519 * exchange as the supplied sequence
520 * @sp: The sequence/exchange to get a new sequence for
522 static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
524 struct fc_exch *ep = fc_seq_exch(sp);
526 sp = fc_seq_alloc(ep, ep->seq_id++);
527 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
533 * fc_seq_start_next() - Lock the exchange and get a new sequence
534 * for a given sequence/exchange pair
535 * @sp: The sequence/exchange to get a new exchange for
537 static struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
539 struct fc_exch *ep = fc_seq_exch(sp);
541 spin_lock_bh(&ep->ex_lock);
542 sp = fc_seq_start_next_locked(sp);
543 spin_unlock_bh(&ep->ex_lock);
549 * fc_seq_exch_abort() - Abort an exchange and sequence
550 * @req_sp: The sequence to be aborted
551 * @timer_msec: The period of time to wait before aborting
553 * Generally called because of a timeout or an abort from the upper layer.
555 static int fc_seq_exch_abort(const struct fc_seq *req_sp,
556 unsigned int timer_msec)
563 ep = fc_seq_exch(req_sp);
565 spin_lock_bh(&ep->ex_lock);
566 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
567 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
568 spin_unlock_bh(&ep->ex_lock);
573 * Send the abort on a new sequence if possible.
575 sp = fc_seq_start_next_locked(&ep->seq);
577 spin_unlock_bh(&ep->ex_lock);
581 ep->esb_stat |= ESB_ST_SEQ_INIT | ESB_ST_ABNORMAL;
583 fc_exch_timer_set_locked(ep, timer_msec);
584 spin_unlock_bh(&ep->ex_lock);
587 * If not logged into the fabric, don't send ABTS but leave
588 * sequence active until next timeout.
594 * Send an abort for the sequence that timed out.
596 fp = fc_frame_alloc(ep->lp, 0);
598 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
599 FC_TYPE_BLS, FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
600 error = fc_seq_send(ep->lp, sp, fp);
607 * fc_exch_timeout() - Handle exchange timer expiration
608 * @work: The work_struct identifying the exchange that timed out
610 static void fc_exch_timeout(struct work_struct *work)
612 struct fc_exch *ep = container_of(work, struct fc_exch,
614 struct fc_seq *sp = &ep->seq;
615 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
620 FC_EXCH_DBG(ep, "Exchange timed out\n");
622 spin_lock_bh(&ep->ex_lock);
623 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
626 e_stat = ep->esb_stat;
627 if (e_stat & ESB_ST_COMPLETE) {
628 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
629 spin_unlock_bh(&ep->ex_lock);
630 if (e_stat & ESB_ST_REC_QUAL)
637 if (e_stat & ESB_ST_ABNORMAL)
638 rc = fc_exch_done_locked(ep);
639 spin_unlock_bh(&ep->ex_lock);
643 resp(sp, ERR_PTR(-FC_EX_TIMEOUT), arg);
644 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
648 spin_unlock_bh(&ep->ex_lock);
651 * This release matches the hold taken when the timer was set.
657 * fc_exch_em_alloc() - Allocate an exchange from a specified EM.
658 * @lport: The local port that the exchange is for
659 * @mp: The exchange manager that will allocate the exchange
661 * Returns pointer to allocated fc_exch with exch lock held.
663 static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
664 struct fc_exch_mgr *mp)
669 struct fc_exch_pool *pool;
671 /* allocate memory for exchange */
672 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);
674 atomic_inc(&mp->stats.no_free_exch);
677 memset(ep, 0, sizeof(*ep));
680 pool = per_cpu_ptr(mp->pool, cpu);
681 spin_lock_bh(&pool->lock);
683 index = pool->next_index;
684 /* allocate new exch from pool */
685 while (fc_exch_ptr_get(pool, index)) {
686 index = index == mp->pool_max_index ? 0 : index + 1;
687 if (index == pool->next_index)
690 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
692 fc_exch_hold(ep); /* hold for exch in mp */
693 spin_lock_init(&ep->ex_lock);
695 * Hold exch lock for caller to prevent fc_exch_reset()
696 * from releasing exch while fc_exch_alloc() caller is
697 * still working on exch.
699 spin_lock_bh(&ep->ex_lock);
701 fc_exch_ptr_set(pool, index, ep);
702 list_add_tail(&ep->ex_list, &pool->ex_list);
703 fc_seq_alloc(ep, ep->seq_id++);
704 pool->total_exches++;
705 spin_unlock_bh(&pool->lock);
710 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
714 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
715 ep->rxid = FC_XID_UNKNOWN;
716 ep->class = mp->class;
717 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
721 spin_unlock_bh(&pool->lock);
722 atomic_inc(&mp->stats.no_free_exch_xid);
723 mempool_free(ep, mp->ep_pool);
728 * fc_exch_alloc() - Allocate an exchange from an EM on a
729 * local port's list of EMs.
730 * @lport: The local port that will own the exchange
731 * @fp: The FC frame that the exchange will be for
733 * This function walks the list of exchange manager(EM)
734 * anchors to select an EM for a new exchange allocation. The
735 * EM is selected when a NULL match function pointer is encountered
736 * or when a call to a match function returns true.
738 static inline struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
741 struct fc_exch_mgr_anchor *ema;
743 list_for_each_entry(ema, &lport->ema_list, ema_list)
744 if (!ema->match || ema->match(fp))
745 return fc_exch_em_alloc(lport, ema->mp);
750 * fc_exch_find() - Lookup and hold an exchange
751 * @mp: The exchange manager to lookup the exchange from
752 * @xid: The XID of the exchange to look up
754 static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
756 struct fc_exch_pool *pool;
757 struct fc_exch *ep = NULL;
759 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
760 pool = per_cpu_ptr(mp->pool, xid & fc_cpu_mask);
761 spin_lock_bh(&pool->lock);
762 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
765 WARN_ON(ep->xid != xid);
767 spin_unlock_bh(&pool->lock);
774 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and
775 * the memory allocated for the related objects may be freed.
776 * @sp: The sequence that has completed
778 static void fc_exch_done(struct fc_seq *sp)
780 struct fc_exch *ep = fc_seq_exch(sp);
783 spin_lock_bh(&ep->ex_lock);
784 rc = fc_exch_done_locked(ep);
785 spin_unlock_bh(&ep->ex_lock);
791 * fc_exch_resp() - Allocate a new exchange for a response frame
792 * @lport: The local port that the exchange was for
793 * @mp: The exchange manager to allocate the exchange from
794 * @fp: The response frame
796 * Sets the responder ID in the frame header.
798 static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
799 struct fc_exch_mgr *mp,
803 struct fc_frame_header *fh;
805 ep = fc_exch_alloc(lport, fp);
807 ep->class = fc_frame_class(fp);
810 * Set EX_CTX indicating we're responding on this exchange.
812 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
813 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
814 fh = fc_frame_header_get(fp);
815 ep->sid = ntoh24(fh->fh_d_id);
816 ep->did = ntoh24(fh->fh_s_id);
820 * Allocated exchange has placed the XID in the
821 * originator field. Move it to the responder field,
822 * and set the originator XID from the frame.
825 ep->oxid = ntohs(fh->fh_ox_id);
826 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
827 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
828 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
830 fc_exch_hold(ep); /* hold for caller */
831 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
837 * fc_seq_lookup_recip() - Find a sequence where the other end
838 * originated the sequence
839 * @lport: The local port that the frame was sent to
840 * @mp: The Exchange Manager to lookup the exchange from
841 * @fp: The frame associated with the sequence we're looking for
843 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
844 * on the ep that should be released by the caller.
846 static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
847 struct fc_exch_mgr *mp,
850 struct fc_frame_header *fh = fc_frame_header_get(fp);
851 struct fc_exch *ep = NULL;
852 struct fc_seq *sp = NULL;
853 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
857 f_ctl = ntoh24(fh->fh_f_ctl);
858 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
861 * Lookup or create the exchange if we will be creating the sequence.
863 if (f_ctl & FC_FC_EX_CTX) {
864 xid = ntohs(fh->fh_ox_id); /* we originated exch */
865 ep = fc_exch_find(mp, xid);
867 atomic_inc(&mp->stats.xid_not_found);
868 reject = FC_RJT_OX_ID;
871 if (ep->rxid == FC_XID_UNKNOWN)
872 ep->rxid = ntohs(fh->fh_rx_id);
873 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
874 reject = FC_RJT_OX_ID;
878 xid = ntohs(fh->fh_rx_id); /* we are the responder */
881 * Special case for MDS issuing an ELS TEST with a
883 * XXX take this out once we do the proper reject.
885 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
886 fc_frame_payload_op(fp) == ELS_TEST) {
887 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
888 xid = FC_XID_UNKNOWN;
892 * new sequence - find the exchange
894 ep = fc_exch_find(mp, xid);
895 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
897 atomic_inc(&mp->stats.xid_busy);
898 reject = FC_RJT_RX_ID;
901 ep = fc_exch_resp(lport, mp, fp);
903 reject = FC_RJT_EXCH_EST; /* XXX */
906 xid = ep->xid; /* get our XID */
908 atomic_inc(&mp->stats.xid_not_found);
909 reject = FC_RJT_RX_ID; /* XID not found */
915 * At this point, we have the exchange held.
916 * Find or create the sequence.
918 if (fc_sof_is_init(fr_sof(fp))) {
920 sp->ssb_stat |= SSB_ST_RESP;
921 sp->id = fh->fh_seq_id;
924 if (sp->id != fh->fh_seq_id) {
925 atomic_inc(&mp->stats.seq_not_found);
926 reject = FC_RJT_SEQ_ID; /* sequence/exch should exist */
930 WARN_ON(ep != fc_seq_exch(sp));
932 if (f_ctl & FC_FC_SEQ_INIT)
933 ep->esb_stat |= ESB_ST_SEQ_INIT;
939 fc_exch_done(&ep->seq);
940 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
945 * fc_seq_lookup_orig() - Find a sequence where this end
946 * originated the sequence
947 * @mp: The Exchange Manager to lookup the exchange from
948 * @fp: The frame associated with the sequence we're looking for
950 * Does not hold the sequence for the caller.
952 static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
955 struct fc_frame_header *fh = fc_frame_header_get(fp);
957 struct fc_seq *sp = NULL;
961 f_ctl = ntoh24(fh->fh_f_ctl);
962 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
963 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
964 ep = fc_exch_find(mp, xid);
967 if (ep->seq.id == fh->fh_seq_id) {
969 * Save the RX_ID if we didn't previously know it.
972 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
973 ep->rxid == FC_XID_UNKNOWN) {
974 ep->rxid = ntohs(fh->fh_rx_id);
982 * fc_exch_set_addr() - Set the source and destination IDs for an exchange
983 * @ep: The exchange to set the addresses for
984 * @orig_id: The originator's ID
985 * @resp_id: The responder's ID
987 * Note this must be done before the first sequence of the exchange is sent.
989 static void fc_exch_set_addr(struct fc_exch *ep,
990 u32 orig_id, u32 resp_id)
993 if (ep->esb_stat & ESB_ST_RESP) {
1003 * fc_seq_els_rsp_send() - Send an ELS response using infomation from
1004 * the existing sequence/exchange.
1005 * @sp: The sequence/exchange to get information from
1006 * @els_cmd: The ELS command to be sent
1007 * @els_data: The ELS data to be sent
1009 static void fc_seq_els_rsp_send(struct fc_seq *sp, enum fc_els_cmd els_cmd,
1010 struct fc_seq_els_data *els_data)
1014 fc_seq_ls_rjt(sp, els_data->reason, els_data->explan);
1020 fc_exch_els_rrq(sp, els_data->fp);
1023 fc_exch_els_rec(sp, els_data->fp);
1026 FC_EXCH_DBG(fc_seq_exch(sp), "Invalid ELS CMD:%x\n", els_cmd);
1031 * fc_seq_send_last() - Send a sequence that is the last in the exchange
1032 * @sp: The sequence that is to be sent
1033 * @fp: The frame that will be sent on the sequence
1034 * @rctl: The R_CTL information to be sent
1035 * @fh_type: The frame header type
1037 static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
1038 enum fc_rctl rctl, enum fc_fh_type fh_type)
1041 struct fc_exch *ep = fc_seq_exch(sp);
1043 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
1045 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
1046 fc_seq_send(ep->lp, sp, fp);
1050 * fc_seq_send_ack() - Send an acknowledgement that we've received a frame
1051 * @sp: The sequence to send the ACK on
1052 * @rx_fp: The received frame that is being acknoledged
1054 * Send ACK_1 (or equiv.) indicating we received something.
1056 static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
1058 struct fc_frame *fp;
1059 struct fc_frame_header *rx_fh;
1060 struct fc_frame_header *fh;
1061 struct fc_exch *ep = fc_seq_exch(sp);
1062 struct fc_lport *lport = ep->lp;
1066 * Don't send ACKs for class 3.
1068 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
1069 fp = fc_frame_alloc(lport, 0);
1073 fh = fc_frame_header_get(fp);
1074 fh->fh_r_ctl = FC_RCTL_ACK_1;
1075 fh->fh_type = FC_TYPE_BLS;
1078 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1079 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1080 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1081 * Last ACK uses bits 7-6 (continue sequence),
1082 * bits 5-4 are meaningful (what kind of ACK to use).
1084 rx_fh = fc_frame_header_get(rx_fp);
1085 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1086 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1087 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
1088 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
1089 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1090 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1091 hton24(fh->fh_f_ctl, f_ctl);
1093 fc_exch_setup_hdr(ep, fp, f_ctl);
1094 fh->fh_seq_id = rx_fh->fh_seq_id;
1095 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1096 fh->fh_parm_offset = htonl(1); /* ack single frame */
1098 fr_sof(fp) = fr_sof(rx_fp);
1099 if (f_ctl & FC_FC_END_SEQ)
1100 fr_eof(fp) = FC_EOF_T;
1102 fr_eof(fp) = FC_EOF_N;
1104 lport->tt.frame_send(lport, fp);
1109 * fc_exch_send_ba_rjt() - Send BLS Reject
1110 * @rx_fp: The frame being rejected
1111 * @reason: The reason the frame is being rejected
1112 * @explan: The explaination for the rejection
1114 * This is for rejecting BA_ABTS only.
1116 static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
1117 enum fc_ba_rjt_reason reason,
1118 enum fc_ba_rjt_explan explan)
1120 struct fc_frame *fp;
1121 struct fc_frame_header *rx_fh;
1122 struct fc_frame_header *fh;
1123 struct fc_ba_rjt *rp;
1124 struct fc_lport *lport;
1127 lport = fr_dev(rx_fp);
1128 fp = fc_frame_alloc(lport, sizeof(*rp));
1131 fh = fc_frame_header_get(fp);
1132 rx_fh = fc_frame_header_get(rx_fp);
1134 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1136 rp = fc_frame_payload_get(fp, sizeof(*rp));
1137 rp->br_reason = reason;
1138 rp->br_explan = explan;
1141 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1143 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1144 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1145 fh->fh_ox_id = rx_fh->fh_ox_id;
1146 fh->fh_rx_id = rx_fh->fh_rx_id;
1147 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1148 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1149 fh->fh_type = FC_TYPE_BLS;
1152 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1153 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1154 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1155 * Last ACK uses bits 7-6 (continue sequence),
1156 * bits 5-4 are meaningful (what kind of ACK to use).
1157 * Always set LAST_SEQ, END_SEQ.
1159 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1160 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1161 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1162 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1163 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1164 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1165 f_ctl &= ~FC_FC_FIRST_SEQ;
1166 hton24(fh->fh_f_ctl, f_ctl);
1168 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1169 fr_eof(fp) = FC_EOF_T;
1170 if (fc_sof_needs_ack(fr_sof(fp)))
1171 fr_eof(fp) = FC_EOF_N;
1173 lport->tt.frame_send(lport, fp);
1177 * fc_exch_recv_abts() - Handle an incoming ABTS
1178 * @ep: The exchange the abort was on
1179 * @rx_fp: The ABTS frame
1181 * This would be for target mode usually, but could be due to lost
1182 * FCP transfer ready, confirm or RRQ. We always handle this as an
1183 * exchange abort, ignoring the parameter.
1185 static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1187 struct fc_frame *fp;
1188 struct fc_ba_acc *ap;
1189 struct fc_frame_header *fh;
1194 spin_lock_bh(&ep->ex_lock);
1195 if (ep->esb_stat & ESB_ST_COMPLETE) {
1196 spin_unlock_bh(&ep->ex_lock);
1199 if (!(ep->esb_stat & ESB_ST_REC_QUAL))
1200 fc_exch_hold(ep); /* hold for REC_QUAL */
1201 ep->esb_stat |= ESB_ST_ABNORMAL | ESB_ST_REC_QUAL;
1202 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1204 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1206 spin_unlock_bh(&ep->ex_lock);
1209 fh = fc_frame_header_get(fp);
1210 ap = fc_frame_payload_get(fp, sizeof(*ap));
1211 memset(ap, 0, sizeof(*ap));
1213 ap->ba_high_seq_cnt = htons(0xffff);
1214 if (sp->ssb_stat & SSB_ST_RESP) {
1215 ap->ba_seq_id = sp->id;
1216 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1217 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1218 ap->ba_low_seq_cnt = htons(sp->cnt);
1220 sp = fc_seq_start_next_locked(sp);
1221 spin_unlock_bh(&ep->ex_lock);
1222 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1223 fc_frame_free(rx_fp);
1227 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1229 fc_frame_free(rx_fp);
1233 * fc_exch_recv_req() - Handler for an incoming request where is other
1234 * end is originating the sequence
1235 * @lport: The local port that received the request
1236 * @mp: The EM that the exchange is on
1237 * @fp: The request frame
1239 static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp,
1240 struct fc_frame *fp)
1242 struct fc_frame_header *fh = fc_frame_header_get(fp);
1243 struct fc_seq *sp = NULL;
1244 struct fc_exch *ep = NULL;
1245 enum fc_pf_rjt_reason reject;
1247 /* We can have the wrong fc_lport at this point with NPIV, which is a
1248 * problem now that we know a new exchange needs to be allocated
1250 lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id));
1257 reject = fc_seq_lookup_recip(lport, mp, fp);
1258 if (reject == FC_RJT_NONE) {
1259 sp = fr_seq(fp); /* sequence will be held */
1260 ep = fc_seq_exch(sp);
1261 fc_seq_send_ack(sp, fp);
1264 * Call the receive function.
1266 * The receive function may allocate a new sequence
1267 * over the old one, so we shouldn't change the
1268 * sequence after this.
1270 * The frame will be freed by the receive function.
1271 * If new exch resp handler is valid then call that
1275 ep->resp(sp, fp, ep->arg);
1277 lport->tt.lport_recv(lport, sp, fp);
1278 fc_exch_release(ep); /* release from lookup */
1280 FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n",
1287 * fc_exch_recv_seq_resp() - Handler for an incoming response where the other
1288 * end is the originator of the sequence that is a
1289 * response to our initial exchange
1290 * @mp: The EM that the exchange is on
1291 * @fp: The response frame
1293 static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1295 struct fc_frame_header *fh = fc_frame_header_get(fp);
1300 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
1304 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1306 atomic_inc(&mp->stats.xid_not_found);
1309 if (ep->esb_stat & ESB_ST_COMPLETE) {
1310 atomic_inc(&mp->stats.xid_not_found);
1313 if (ep->rxid == FC_XID_UNKNOWN)
1314 ep->rxid = ntohs(fh->fh_rx_id);
1315 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1316 atomic_inc(&mp->stats.xid_not_found);
1319 if (ep->did != ntoh24(fh->fh_s_id) &&
1320 ep->did != FC_FID_FLOGI) {
1321 atomic_inc(&mp->stats.xid_not_found);
1326 if (fc_sof_is_init(sof)) {
1327 sp->ssb_stat |= SSB_ST_RESP;
1328 sp->id = fh->fh_seq_id;
1329 } else if (sp->id != fh->fh_seq_id) {
1330 atomic_inc(&mp->stats.seq_not_found);
1334 f_ctl = ntoh24(fh->fh_f_ctl);
1336 if (f_ctl & FC_FC_SEQ_INIT)
1337 ep->esb_stat |= ESB_ST_SEQ_INIT;
1339 if (fc_sof_needs_ack(sof))
1340 fc_seq_send_ack(sp, fp);
1342 ex_resp_arg = ep->arg;
1344 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1345 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1346 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1347 spin_lock_bh(&ep->ex_lock);
1348 rc = fc_exch_done_locked(ep);
1349 WARN_ON(fc_seq_exch(sp) != ep);
1350 spin_unlock_bh(&ep->ex_lock);
1356 * Call the receive function.
1357 * The sequence is held (has a refcnt) for us,
1358 * but not for the receive function.
1360 * The receive function may allocate a new sequence
1361 * over the old one, so we shouldn't change the
1362 * sequence after this.
1364 * The frame will be freed by the receive function.
1365 * If new exch resp handler is valid then call that
1369 resp(sp, fp, ex_resp_arg);
1372 fc_exch_release(ep);
1375 fc_exch_release(ep);
1381 * fc_exch_recv_resp() - Handler for a sequence where other end is
1382 * responding to our sequence
1383 * @mp: The EM that the exchange is on
1384 * @fp: The response frame
1386 static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1390 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1393 atomic_inc(&mp->stats.xid_not_found);
1395 atomic_inc(&mp->stats.non_bls_resp);
1401 * fc_exch_abts_resp() - Handler for a response to an ABT
1402 * @ep: The exchange that the frame is on
1403 * @fp: The response frame
1405 * This response would be to an ABTS cancelling an exchange or sequence.
1406 * The response can be either BA_ACC or BA_RJT
1408 static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1410 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
1412 struct fc_frame_header *fh;
1413 struct fc_ba_acc *ap;
1417 int rc = 1, has_rec = 0;
1419 fh = fc_frame_header_get(fp);
1420 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1421 fc_exch_rctl_name(fh->fh_r_ctl));
1423 if (cancel_delayed_work_sync(&ep->timeout_work))
1424 fc_exch_release(ep); /* release from pending timer hold */
1426 spin_lock_bh(&ep->ex_lock);
1427 switch (fh->fh_r_ctl) {
1428 case FC_RCTL_BA_ACC:
1429 ap = fc_frame_payload_get(fp, sizeof(*ap));
1434 * Decide whether to establish a Recovery Qualifier.
1435 * We do this if there is a non-empty SEQ_CNT range and
1436 * SEQ_ID is the same as the one we aborted.
1438 low = ntohs(ap->ba_low_seq_cnt);
1439 high = ntohs(ap->ba_high_seq_cnt);
1440 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1441 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1442 ap->ba_seq_id == ep->seq_id) && low != high) {
1443 ep->esb_stat |= ESB_ST_REC_QUAL;
1444 fc_exch_hold(ep); /* hold for recovery qualifier */
1448 case FC_RCTL_BA_RJT:
1455 ex_resp_arg = ep->arg;
1457 /* do we need to do some other checks here. Can we reuse more of
1458 * fc_exch_recv_seq_resp
1462 * do we want to check END_SEQ as well as LAST_SEQ here?
1464 if (ep->fh_type != FC_TYPE_FCP &&
1465 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1466 rc = fc_exch_done_locked(ep);
1467 spin_unlock_bh(&ep->ex_lock);
1472 resp(sp, fp, ex_resp_arg);
1477 fc_exch_timer_set(ep, ep->r_a_tov);
1482 * fc_exch_recv_bls() - Handler for a BLS sequence
1483 * @mp: The EM that the exchange is on
1484 * @fp: The request frame
1486 * The BLS frame is always a sequence initiated by the remote side.
1487 * We may be either the originator or recipient of the exchange.
1489 static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1491 struct fc_frame_header *fh;
1495 fh = fc_frame_header_get(fp);
1496 f_ctl = ntoh24(fh->fh_f_ctl);
1499 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1500 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1501 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1502 spin_lock_bh(&ep->ex_lock);
1503 ep->esb_stat |= ESB_ST_SEQ_INIT;
1504 spin_unlock_bh(&ep->ex_lock);
1506 if (f_ctl & FC_FC_SEQ_CTX) {
1508 * A response to a sequence we initiated.
1509 * This should only be ACKs for class 2 or F.
1511 switch (fh->fh_r_ctl) {
1516 FC_EXCH_DBG(ep, "BLS rctl %x - %s received",
1518 fc_exch_rctl_name(fh->fh_r_ctl));
1523 switch (fh->fh_r_ctl) {
1524 case FC_RCTL_BA_RJT:
1525 case FC_RCTL_BA_ACC:
1527 fc_exch_abts_resp(ep, fp);
1531 case FC_RCTL_BA_ABTS:
1532 fc_exch_recv_abts(ep, fp);
1534 default: /* ignore junk */
1540 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1544 * fc_seq_ls_acc() - Accept sequence with LS_ACC
1545 * @req_sp: The request sequence
1547 * If this fails due to allocation or transmit congestion, assume the
1548 * originator will repeat the sequence.
1550 static void fc_seq_ls_acc(struct fc_seq *req_sp)
1553 struct fc_els_ls_acc *acc;
1554 struct fc_frame *fp;
1556 sp = fc_seq_start_next(req_sp);
1557 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*acc));
1559 acc = fc_frame_payload_get(fp, sizeof(*acc));
1560 memset(acc, 0, sizeof(*acc));
1561 acc->la_cmd = ELS_LS_ACC;
1562 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1567 * fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT
1568 * @req_sp: The request sequence
1569 * @reason: The reason the sequence is being rejected
1570 * @explan: The explaination for the rejection
1572 * If this fails due to allocation or transmit congestion, assume the
1573 * originator will repeat the sequence.
1575 static void fc_seq_ls_rjt(struct fc_seq *req_sp, enum fc_els_rjt_reason reason,
1576 enum fc_els_rjt_explan explan)
1579 struct fc_els_ls_rjt *rjt;
1580 struct fc_frame *fp;
1582 sp = fc_seq_start_next(req_sp);
1583 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*rjt));
1585 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1586 memset(rjt, 0, sizeof(*rjt));
1587 rjt->er_cmd = ELS_LS_RJT;
1588 rjt->er_reason = reason;
1589 rjt->er_explan = explan;
1590 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1595 * fc_exch_reset() - Reset an exchange
1596 * @ep: The exchange to be reset
1598 static void fc_exch_reset(struct fc_exch *ep)
1601 void (*resp)(struct fc_seq *, struct fc_frame *, void *);
1605 spin_lock_bh(&ep->ex_lock);
1606 ep->state |= FC_EX_RST_CLEANUP;
1607 if (cancel_delayed_work(&ep->timeout_work))
1608 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
1611 if (ep->esb_stat & ESB_ST_REC_QUAL)
1612 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1613 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1616 rc = fc_exch_done_locked(ep);
1617 spin_unlock_bh(&ep->ex_lock);
1622 resp(sp, ERR_PTR(-FC_EX_CLOSED), arg);
1626 * fc_exch_pool_reset() - Reset a per cpu exchange pool
1627 * @lport: The local port that the exchange pool is on
1628 * @pool: The exchange pool to be reset
1629 * @sid: The source ID
1630 * @did: The destination ID
1632 * Resets a per cpu exches pool, releasing all of its sequences
1633 * and exchanges. If sid is non-zero then reset only exchanges
1634 * we sourced from the local port's FID. If did is non-zero then
1635 * only reset exchanges destined for the local port's FID.
1637 static void fc_exch_pool_reset(struct fc_lport *lport,
1638 struct fc_exch_pool *pool,
1642 struct fc_exch *next;
1644 spin_lock_bh(&pool->lock);
1646 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1647 if ((lport == ep->lp) &&
1648 (sid == 0 || sid == ep->sid) &&
1649 (did == 0 || did == ep->did)) {
1651 spin_unlock_bh(&pool->lock);
1655 fc_exch_release(ep);
1656 spin_lock_bh(&pool->lock);
1659 * must restart loop incase while lock
1660 * was down multiple eps were released.
1665 spin_unlock_bh(&pool->lock);
1669 * fc_exch_mgr_reset() - Reset all EMs of a local port
1670 * @lport: The local port whose EMs are to be reset
1671 * @sid: The source ID
1672 * @did: The destination ID
1674 * Reset all EMs associated with a given local port. Release all
1675 * sequences and exchanges. If sid is non-zero then reset only the
1676 * exchanges sent from the local port's FID. If did is non-zero then
1677 * reset only exchanges destined for the local port's FID.
1679 void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1681 struct fc_exch_mgr_anchor *ema;
1684 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1685 for_each_possible_cpu(cpu)
1686 fc_exch_pool_reset(lport,
1687 per_cpu_ptr(ema->mp->pool, cpu),
1691 EXPORT_SYMBOL(fc_exch_mgr_reset);
1694 * fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests
1695 * @sp: The sequence the REC is on
1696 * @rfp: The REC frame
1698 * Note that the requesting port may be different than the S_ID in the request.
1700 static void fc_exch_els_rec(struct fc_seq *sp, struct fc_frame *rfp)
1702 struct fc_frame *fp;
1704 struct fc_exch_mgr *em;
1705 struct fc_els_rec *rp;
1706 struct fc_els_rec_acc *acc;
1707 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
1708 enum fc_els_rjt_explan explan;
1713 rp = fc_frame_payload_get(rfp, sizeof(*rp));
1714 explan = ELS_EXPL_INV_LEN;
1717 sid = ntoh24(rp->rec_s_id);
1718 rxid = ntohs(rp->rec_rx_id);
1719 oxid = ntohs(rp->rec_ox_id);
1722 * Currently it's hard to find the local S_ID from the exchange
1723 * manager. This will eventually be fixed, but for now it's easier
1724 * to lookup the subject exchange twice, once as if we were
1725 * the initiator, and then again if we weren't.
1727 em = fc_seq_exch(sp)->em;
1728 ep = fc_exch_find(em, oxid);
1729 explan = ELS_EXPL_OXID_RXID;
1730 if (ep && ep->oid == sid) {
1731 if (ep->rxid != FC_XID_UNKNOWN &&
1732 rxid != FC_XID_UNKNOWN &&
1737 fc_exch_release(ep);
1739 if (rxid != FC_XID_UNKNOWN)
1740 ep = fc_exch_find(em, rxid);
1745 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*acc));
1750 acc = fc_frame_payload_get(fp, sizeof(*acc));
1751 memset(acc, 0, sizeof(*acc));
1752 acc->reca_cmd = ELS_LS_ACC;
1753 acc->reca_ox_id = rp->rec_ox_id;
1754 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
1755 acc->reca_rx_id = htons(ep->rxid);
1756 if (ep->sid == ep->oid)
1757 hton24(acc->reca_rfid, ep->did);
1759 hton24(acc->reca_rfid, ep->sid);
1760 acc->reca_fc4value = htonl(ep->seq.rec_data);
1761 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
1764 sp = fc_seq_start_next(sp);
1765 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1767 fc_exch_release(ep);
1772 fc_exch_release(ep);
1774 fc_seq_ls_rjt(sp, reason, explan);
1779 * fc_exch_rrq_resp() - Handler for RRQ responses
1780 * @sp: The sequence that the RRQ is on
1781 * @fp: The RRQ frame
1782 * @arg: The exchange that the RRQ is on
1784 * TODO: fix error handler.
1786 static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
1788 struct fc_exch *aborted_ep = arg;
1792 int err = PTR_ERR(fp);
1794 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
1796 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
1797 "frame error %d\n", err);
1801 op = fc_frame_payload_op(fp);
1806 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ");
1811 FC_EXCH_DBG(aborted_ep, "unexpected response op %x "
1817 fc_exch_done(&aborted_ep->seq);
1818 /* drop hold for rec qual */
1819 fc_exch_release(aborted_ep);
1824 * fc_exch_seq_send() - Send a frame using a new exchange and sequence
1825 * @lport: The local port to send the frame on
1826 * @fp: The frame to be sent
1827 * @resp: The response handler for this request
1828 * @destructor: The destructor for the exchange
1829 * @arg: The argument to be passed to the response handler
1830 * @timer_msec: The timeout period for the exchange
1832 * The frame pointer with some of the header's fields must be
1833 * filled before calling this routine, those fields are:
1840 * - parameter or relative offset
1842 static struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
1843 struct fc_frame *fp,
1844 void (*resp)(struct fc_seq *,
1845 struct fc_frame *fp,
1847 void (*destructor)(struct fc_seq *,
1849 void *arg, u32 timer_msec)
1852 struct fc_seq *sp = NULL;
1853 struct fc_frame_header *fh;
1856 ep = fc_exch_alloc(lport, fp);
1861 ep->esb_stat |= ESB_ST_SEQ_INIT;
1862 fh = fc_frame_header_get(fp);
1863 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
1865 ep->destructor = destructor;
1867 ep->r_a_tov = FC_DEF_R_A_TOV;
1871 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
1872 ep->f_ctl = ntoh24(fh->fh_f_ctl);
1873 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
1876 if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD)
1877 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
1879 if (unlikely(lport->tt.frame_send(lport, fp)))
1883 fc_exch_timer_set_locked(ep, timer_msec);
1884 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
1886 if (ep->f_ctl & FC_FC_SEQ_INIT)
1887 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
1888 spin_unlock_bh(&ep->ex_lock);
1891 rc = fc_exch_done_locked(ep);
1892 spin_unlock_bh(&ep->ex_lock);
1899 * fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command
1900 * @ep: The exchange to send the RRQ on
1902 * This tells the remote port to stop blocking the use of
1903 * the exchange and the seq_cnt range.
1905 static void fc_exch_rrq(struct fc_exch *ep)
1907 struct fc_lport *lport;
1908 struct fc_els_rrq *rrq;
1909 struct fc_frame *fp;
1914 fp = fc_frame_alloc(lport, sizeof(*rrq));
1918 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
1919 memset(rrq, 0, sizeof(*rrq));
1920 rrq->rrq_cmd = ELS_RRQ;
1921 hton24(rrq->rrq_s_id, ep->sid);
1922 rrq->rrq_ox_id = htons(ep->oxid);
1923 rrq->rrq_rx_id = htons(ep->rxid);
1926 if (ep->esb_stat & ESB_ST_RESP)
1929 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
1930 lport->port_id, FC_TYPE_ELS,
1931 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1933 if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep,
1938 spin_lock_bh(&ep->ex_lock);
1939 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
1940 spin_unlock_bh(&ep->ex_lock);
1941 /* drop hold for rec qual */
1942 fc_exch_release(ep);
1945 ep->esb_stat |= ESB_ST_REC_QUAL;
1946 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1947 spin_unlock_bh(&ep->ex_lock);
1952 * fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests
1953 * @sp: The sequence that the RRQ is on
1954 * @fp: The RRQ frame
1956 static void fc_exch_els_rrq(struct fc_seq *sp, struct fc_frame *fp)
1958 struct fc_exch *ep = NULL; /* request or subject exchange */
1959 struct fc_els_rrq *rp;
1962 enum fc_els_rjt_explan explan;
1964 rp = fc_frame_payload_get(fp, sizeof(*rp));
1965 explan = ELS_EXPL_INV_LEN;
1970 * lookup subject exchange.
1972 ep = fc_seq_exch(sp);
1973 sid = ntoh24(rp->rrq_s_id); /* subject source */
1974 xid = ep->did == sid ? ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
1975 ep = fc_exch_find(ep->em, xid);
1977 explan = ELS_EXPL_OXID_RXID;
1980 spin_lock_bh(&ep->ex_lock);
1981 if (ep->oxid != ntohs(rp->rrq_ox_id))
1983 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
1984 ep->rxid != FC_XID_UNKNOWN)
1986 explan = ELS_EXPL_SID;
1991 * Clear Recovery Qualifier state, and cancel timer if complete.
1993 if (ep->esb_stat & ESB_ST_REC_QUAL) {
1994 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1995 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
1997 if (ep->esb_stat & ESB_ST_COMPLETE) {
1998 if (cancel_delayed_work(&ep->timeout_work))
1999 atomic_dec(&ep->ex_refcnt); /* drop timer hold */
2002 spin_unlock_bh(&ep->ex_lock);
2011 spin_unlock_bh(&ep->ex_lock);
2013 fc_seq_ls_rjt(sp, ELS_RJT_LOGIC, explan);
2017 fc_exch_release(ep); /* drop hold from fc_exch_find */
2021 * fc_exch_mgr_add() - Add an exchange manager to a local port's list of EMs
2022 * @lport: The local port to add the exchange manager to
2023 * @mp: The exchange manager to be added to the local port
2024 * @match: The match routine that indicates when this EM should be used
2026 struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
2027 struct fc_exch_mgr *mp,
2028 bool (*match)(struct fc_frame *))
2030 struct fc_exch_mgr_anchor *ema;
2032 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
2038 /* add EM anchor to EM anchors list */
2039 list_add_tail(&ema->ema_list, &lport->ema_list);
2040 kref_get(&mp->kref);
2043 EXPORT_SYMBOL(fc_exch_mgr_add);
2046 * fc_exch_mgr_destroy() - Destroy an exchange manager
2047 * @kref: The reference to the EM to be destroyed
2049 static void fc_exch_mgr_destroy(struct kref *kref)
2051 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
2053 mempool_destroy(mp->ep_pool);
2054 free_percpu(mp->pool);
2059 * fc_exch_mgr_del() - Delete an EM from a local port's list
2060 * @ema: The exchange manager anchor identifying the EM to be deleted
2062 void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
2064 /* remove EM anchor from EM anchors list */
2065 list_del(&ema->ema_list);
2066 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
2069 EXPORT_SYMBOL(fc_exch_mgr_del);
2072 * fc_exch_mgr_list_clone() - Share all exchange manager objects
2073 * @src: Source lport to clone exchange managers from
2074 * @dst: New lport that takes references to all the exchange managers
2076 int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)
2078 struct fc_exch_mgr_anchor *ema, *tmp;
2080 list_for_each_entry(ema, &src->ema_list, ema_list) {
2081 if (!fc_exch_mgr_add(dst, ema->mp, ema->match))
2086 list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)
2087 fc_exch_mgr_del(ema);
2092 * fc_exch_mgr_alloc() - Allocate an exchange manager
2093 * @lport: The local port that the new EM will be associated with
2094 * @class: The default FC class for new exchanges
2095 * @min_xid: The minimum XID for exchanges from the new EM
2096 * @max_xid: The maximum XID for exchanges from the new EM
2097 * @match: The match routine for the new EM
2099 struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport,
2100 enum fc_class class,
2101 u16 min_xid, u16 max_xid,
2102 bool (*match)(struct fc_frame *))
2104 struct fc_exch_mgr *mp;
2105 u16 pool_exch_range;
2108 struct fc_exch_pool *pool;
2110 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
2111 (min_xid & fc_cpu_mask) != 0) {
2112 FC_LPORT_DBG(lport, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
2118 * allocate memory for EM
2120 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
2125 /* adjust em exch xid range for offload */
2126 mp->min_xid = min_xid;
2127 mp->max_xid = max_xid;
2129 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
2134 * Setup per cpu exch pool with entire exchange id range equally
2135 * divided across all cpus. The exch pointers array memory is
2136 * allocated for exch range per pool.
2138 pool_exch_range = (mp->max_xid - mp->min_xid + 1) / (fc_cpu_mask + 1);
2139 mp->pool_max_index = pool_exch_range - 1;
2142 * Allocate and initialize per cpu exch pool
2144 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
2145 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
2148 for_each_possible_cpu(cpu) {
2149 pool = per_cpu_ptr(mp->pool, cpu);
2150 spin_lock_init(&pool->lock);
2151 INIT_LIST_HEAD(&pool->ex_list);
2154 kref_init(&mp->kref);
2155 if (!fc_exch_mgr_add(lport, mp, match)) {
2156 free_percpu(mp->pool);
2161 * Above kref_init() sets mp->kref to 1 and then
2162 * call to fc_exch_mgr_add incremented mp->kref again,
2163 * so adjust that extra increment.
2165 kref_put(&mp->kref, fc_exch_mgr_destroy);
2169 mempool_destroy(mp->ep_pool);
2174 EXPORT_SYMBOL(fc_exch_mgr_alloc);
2177 * fc_exch_mgr_free() - Free all exchange managers on a local port
2178 * @lport: The local port whose EMs are to be freed
2180 void fc_exch_mgr_free(struct fc_lport *lport)
2182 struct fc_exch_mgr_anchor *ema, *next;
2184 flush_workqueue(fc_exch_workqueue);
2185 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
2186 fc_exch_mgr_del(ema);
2188 EXPORT_SYMBOL(fc_exch_mgr_free);
2191 * fc_exch_recv() - Handler for received frames
2192 * @lport: The local port the frame was received on
2193 * @fp: The received frame
2195 void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)
2197 struct fc_frame_header *fh = fc_frame_header_get(fp);
2198 struct fc_exch_mgr_anchor *ema;
2199 u32 f_ctl, found = 0;
2203 if (!lport || lport->state == LPORT_ST_DISABLED) {
2204 FC_LPORT_DBG(lport, "Receiving frames for an lport that "
2205 "has not been initialized correctly\n");
2210 f_ctl = ntoh24(fh->fh_f_ctl);
2211 oxid = ntohs(fh->fh_ox_id);
2212 if (f_ctl & FC_FC_EX_CTX) {
2213 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2214 if ((oxid >= ema->mp->min_xid) &&
2215 (oxid <= ema->mp->max_xid)) {
2222 FC_LPORT_DBG(lport, "Received response for out "
2223 "of range oxid:%hx\n", oxid);
2228 ema = list_entry(lport->ema_list.prev, typeof(*ema), ema_list);
2231 * If frame is marked invalid, just drop it.
2233 switch (fr_eof(fp)) {
2235 if (f_ctl & FC_FC_END_SEQ)
2236 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2239 if (fh->fh_type == FC_TYPE_BLS)
2240 fc_exch_recv_bls(ema->mp, fp);
2241 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2243 fc_exch_recv_seq_resp(ema->mp, fp);
2244 else if (f_ctl & FC_FC_SEQ_CTX)
2245 fc_exch_recv_resp(ema->mp, fp);
2247 fc_exch_recv_req(lport, ema->mp, fp);
2250 FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)",
2255 EXPORT_SYMBOL(fc_exch_recv);
2258 * fc_exch_init() - Initialize the exchange layer for a local port
2259 * @lport: The local port to initialize the exchange layer for
2261 int fc_exch_init(struct fc_lport *lport)
2263 if (!lport->tt.seq_start_next)
2264 lport->tt.seq_start_next = fc_seq_start_next;
2266 if (!lport->tt.exch_seq_send)
2267 lport->tt.exch_seq_send = fc_exch_seq_send;
2269 if (!lport->tt.seq_send)
2270 lport->tt.seq_send = fc_seq_send;
2272 if (!lport->tt.seq_els_rsp_send)
2273 lport->tt.seq_els_rsp_send = fc_seq_els_rsp_send;
2275 if (!lport->tt.exch_done)
2276 lport->tt.exch_done = fc_exch_done;
2278 if (!lport->tt.exch_mgr_reset)
2279 lport->tt.exch_mgr_reset = fc_exch_mgr_reset;
2281 if (!lport->tt.seq_exch_abort)
2282 lport->tt.seq_exch_abort = fc_seq_exch_abort;
2286 EXPORT_SYMBOL(fc_exch_init);
2289 * fc_setup_exch_mgr() - Setup an exchange manager
2291 int fc_setup_exch_mgr()
2293 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2294 0, SLAB_HWCACHE_ALIGN, NULL);
2299 * Initialize fc_cpu_mask and fc_cpu_order. The
2300 * fc_cpu_mask is set for nr_cpu_ids rounded up
2301 * to order of 2's * power and order is stored
2302 * in fc_cpu_order as this is later required in
2303 * mapping between an exch id and exch array index
2304 * in per cpu exch pool.
2306 * This round up is required to align fc_cpu_mask
2307 * to exchange id's lower bits such that all incoming
2308 * frames of an exchange gets delivered to the same
2309 * cpu on which exchange originated by simple bitwise
2310 * AND operation between fc_cpu_mask and exchange id.
2314 while (fc_cpu_mask < nr_cpu_ids) {
2320 fc_exch_workqueue = create_singlethread_workqueue("fc_exch_workqueue");
2321 if (!fc_exch_workqueue)
2327 * fc_destroy_exch_mgr() - Destroy an exchange manager
2329 void fc_destroy_exch_mgr()
2331 destroy_workqueue(fc_exch_workqueue);
2332 kmem_cache_destroy(fc_em_cachep);