2 * Copyright(c) 2007 Intel Corporation. All rights reserved.
3 * Copyright(c) 2008 Red Hat, Inc. All rights reserved.
4 * Copyright(c) 2008 Mike Christie
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19 * Maintained at www.Open-FCoE.org
23 * Fibre Channel exchange and sequence handling.
26 #include <linux/timer.h>
27 #include <linux/gfp.h>
28 #include <linux/err.h>
30 #include <scsi/fc/fc_fc2.h>
32 #include <scsi/libfc.h>
33 #include <scsi/fc_encode.h>
37 u16 fc_cpu_mask; /* cpu mask for possible cpus */
38 EXPORT_SYMBOL(fc_cpu_mask);
39 static u16 fc_cpu_order; /* 2's power to represent total possible cpus */
40 static struct kmem_cache *fc_em_cachep; /* cache for exchanges */
43 * Structure and function definitions for managing Fibre Channel Exchanges
46 * The three primary structures used here are fc_exch_mgr, fc_exch, and fc_seq.
48 * fc_exch_mgr holds the exchange state for an N port
50 * fc_exch holds state for one exchange and links to its active sequence.
52 * fc_seq holds the state for an individual sequence.
56 * struct fc_exch_pool - Per cpu exchange pool
57 * @next_index: Next possible free exchange index
58 * @total_exches: Total allocated exchanges
59 * @lock: Exch pool lock
60 * @ex_list: List of exchanges
62 * This structure manages per cpu exchanges in array of exchange pointers.
63 * This array is allocated followed by struct fc_exch_pool memory for
64 * assigned range of exchanges to per cpu pool.
70 struct list_head ex_list;
74 * struct fc_exch_mgr - The Exchange Manager (EM).
75 * @class: Default class for new sequences
76 * @kref: Reference counter
77 * @min_xid: Minimum exchange ID
78 * @max_xid: Maximum exchange ID
79 * @ep_pool: Reserved exchange pointers
80 * @pool_max_index: Max exch array index in exch pool
81 * @pool: Per cpu exch pool
82 * @stats: Statistics structure
84 * This structure is the center for creating exchanges and sequences.
85 * It manages the allocation of exchange IDs.
94 struct fc_exch_pool *pool;
97 * currently exchange mgr stats are updated but not used.
98 * either stats can be expose via sysfs or remove them
99 * all together if not used XXX
102 atomic_t no_free_exch;
103 atomic_t no_free_exch_xid;
104 atomic_t xid_not_found;
106 atomic_t seq_not_found;
107 atomic_t non_bls_resp;
110 #define fc_seq_exch(sp) container_of(sp, struct fc_exch, seq)
113 * struct fc_exch_mgr_anchor - primary structure for list of EMs
114 * @ema_list: Exchange Manager Anchor list
115 * @mp: Exchange Manager associated with this anchor
116 * @match: Routine to determine if this anchor's EM should be used
118 * When walking the list of anchors the match routine will be called
119 * for each anchor to determine if that EM should be used. The last
120 * anchor in the list will always match to handle any exchanges not
121 * handled by other EMs. The non-default EMs would be added to the
122 * anchor list by HW that provides FCoE offloads.
124 struct fc_exch_mgr_anchor {
125 struct list_head ema_list;
126 struct fc_exch_mgr *mp;
127 bool (*match)(struct fc_frame *);
130 static void fc_exch_rrq(struct fc_exch *);
131 static void fc_seq_ls_acc(struct fc_seq *);
132 static void fc_seq_ls_rjt(struct fc_seq *, enum fc_els_rjt_reason,
133 enum fc_els_rjt_explan);
134 static void fc_exch_els_rec(struct fc_seq *, struct fc_frame *);
135 static void fc_exch_els_rrq(struct fc_seq *, struct fc_frame *);
138 * Internal implementation notes.
140 * The exchange manager is one by default in libfc but LLD may choose
141 * to have one per CPU. The sequence manager is one per exchange manager
142 * and currently never separated.
144 * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field
145 * assigned by the Sequence Initiator that shall be unique for a specific
146 * D_ID and S_ID pair while the Sequence is open." Note that it isn't
147 * qualified by exchange ID, which one might think it would be.
148 * In practice this limits the number of open sequences and exchanges to 256
149 * per session. For most targets we could treat this limit as per exchange.
151 * The exchange and its sequence are freed when the last sequence is received.
152 * It's possible for the remote port to leave an exchange open without
153 * sending any sequences.
155 * Notes on reference counts:
157 * Exchanges are reference counted and exchange gets freed when the reference
158 * count becomes zero.
161 * Sequences are timed out for E_D_TOV and R_A_TOV.
163 * Sequence event handling:
165 * The following events may occur on initiator sequences:
168 * For now, the whole thing is sent.
170 * This applies only to class F.
171 * The sequence is marked complete.
173 * The upper layer calls fc_exch_done() when done
174 * with exchange and sequence tuple.
175 * RX-inferred completion.
176 * When we receive the next sequence on the same exchange, we can
177 * retire the previous sequence ID. (XXX not implemented).
179 * R_A_TOV frees the sequence ID. If we're waiting for ACK,
180 * E_D_TOV causes abort and calls upper layer response handler
181 * with FC_EX_TIMEOUT error.
187 * The following events may occur on recipient sequences:
190 * Allocate sequence for first frame received.
191 * Hold during receive handler.
192 * Release when final frame received.
193 * Keep status of last N of these for the ELS RES command. XXX TBD.
195 * Deallocate sequence
199 * For now, we neglect conditions where only part of a sequence was
200 * received or transmitted, or where out-of-order receipt is detected.
206 * The EM code run in a per-CPU worker thread.
208 * To protect against concurrency between a worker thread code and timers,
209 * sequence allocation and deallocation must be locked.
210 * - exchange refcnt can be done atomicly without locks.
211 * - sequence allocation must be locked by exch lock.
212 * - If the EM pool lock and ex_lock must be taken at the same time, then the
213 * EM pool lock must be taken before the ex_lock.
217 * opcode names for debugging.
219 static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;
221 #define FC_TABLE_SIZE(x) (sizeof(x) / sizeof(x[0]))
224 * fc_exch_name_lookup() - Lookup name by opcode
225 * @op: Opcode to be looked up
226 * @table: Opcode/name table
227 * @max_index: Index not to be exceeded
229 * This routine is used to determine a human-readable string identifying
232 static inline const char *fc_exch_name_lookup(unsigned int op, char **table,
233 unsigned int max_index)
235 const char *name = NULL;
245 * fc_exch_rctl_name() - Wrapper routine for fc_exch_name_lookup()
246 * @op: The opcode to be looked up
248 static const char *fc_exch_rctl_name(unsigned int op)
250 return fc_exch_name_lookup(op, fc_exch_rctl_names,
251 FC_TABLE_SIZE(fc_exch_rctl_names));
255 * fc_exch_hold() - Increment an exchange's reference count
256 * @ep: Echange to be held
258 static inline void fc_exch_hold(struct fc_exch *ep)
260 atomic_inc(&ep->ex_refcnt);
264 * fc_exch_setup_hdr() - Initialize a FC header by initializing some fields
265 * and determine SOF and EOF.
266 * @ep: The exchange to that will use the header
267 * @fp: The frame whose header is to be modified
268 * @f_ctl: F_CTL bits that will be used for the frame header
270 * The fields initialized by this routine are: fh_ox_id, fh_rx_id,
271 * fh_seq_id, fh_seq_cnt and the SOF and EOF.
273 static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,
276 struct fc_frame_header *fh = fc_frame_header_get(fp);
279 fr_sof(fp) = ep->class;
281 fr_sof(fp) = fc_sof_normal(ep->class);
283 if (f_ctl & FC_FC_END_SEQ) {
284 fr_eof(fp) = FC_EOF_T;
285 if (fc_sof_needs_ack(ep->class))
286 fr_eof(fp) = FC_EOF_N;
289 * The number of fill bytes to make the length a 4-byte
290 * multiple is the low order 2-bits of the f_ctl.
291 * The fill itself will have been cleared by the frame
293 * After this, the length will be even, as expected by
296 fill = fr_len(fp) & 3;
299 /* TODO, this may be a problem with fragmented skb */
300 skb_put(fp_skb(fp), fill);
301 hton24(fh->fh_f_ctl, f_ctl | fill);
304 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
305 fr_eof(fp) = FC_EOF_N;
309 * Initialize remainig fh fields
310 * from fc_fill_fc_hdr
312 fh->fh_ox_id = htons(ep->oxid);
313 fh->fh_rx_id = htons(ep->rxid);
314 fh->fh_seq_id = ep->seq.id;
315 fh->fh_seq_cnt = htons(ep->seq.cnt);
319 * fc_exch_release() - Decrement an exchange's reference count
320 * @ep: Exchange to be released
322 * If the reference count reaches zero and the exchange is complete,
325 static void fc_exch_release(struct fc_exch *ep)
327 struct fc_exch_mgr *mp;
329 if (atomic_dec_and_test(&ep->ex_refcnt)) {
332 ep->destructor(&ep->seq, ep->arg);
333 WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));
334 mempool_free(ep, mp->ep_pool);
339 * fc_exch_done_locked() - Complete an exchange with the exchange lock held
340 * @ep: The exchange that is complete
342 static int fc_exch_done_locked(struct fc_exch *ep)
347 * We must check for completion in case there are two threads
348 * tyring to complete this. But the rrq code will reuse the
349 * ep, and in that case we only clear the resp and set it as
350 * complete, so it can be reused by the timer to send the rrq.
353 if (ep->state & FC_EX_DONE)
355 ep->esb_stat |= ESB_ST_COMPLETE;
357 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
358 ep->state |= FC_EX_DONE;
359 if (cancel_delayed_work(&ep->timeout_work))
360 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
367 * fc_exch_ptr_get() - Return an exchange from an exchange pool
368 * @pool: Exchange Pool to get an exchange from
369 * @index: Index of the exchange within the pool
371 * Use the index to get an exchange from within an exchange pool. exches
372 * will point to an array of exchange pointers. The index will select
373 * the exchange within the array.
375 static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,
378 struct fc_exch **exches = (struct fc_exch **)(pool + 1);
379 return exches[index];
383 * fc_exch_ptr_set() - Assign an exchange to a slot in an exchange pool
384 * @pool: The pool to assign the exchange to
385 * @index: The index in the pool where the exchange will be assigned
386 * @ep: The exchange to assign to the pool
388 static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
391 ((struct fc_exch **)(pool + 1))[index] = ep;
395 * fc_exch_delete() - Delete an exchange
396 * @ep: The exchange to be deleted
398 static void fc_exch_delete(struct fc_exch *ep)
400 struct fc_exch_pool *pool;
403 spin_lock_bh(&pool->lock);
404 WARN_ON(pool->total_exches <= 0);
405 pool->total_exches--;
406 fc_exch_ptr_set(pool, (ep->xid - ep->em->min_xid) >> fc_cpu_order,
408 list_del(&ep->ex_list);
409 spin_unlock_bh(&pool->lock);
410 fc_exch_release(ep); /* drop hold for exch in mp */
414 * fc_exch_timer_set_locked() - Start a timer for an exchange w/ the
415 * the exchange lock held
416 * @ep: The exchange whose timer will start
417 * @timer_msec: The timeout period
419 * Used for upper level protocols to time out the exchange.
420 * The timer is cancelled when it fires or when the exchange completes.
422 static inline void fc_exch_timer_set_locked(struct fc_exch *ep,
423 unsigned int timer_msec)
425 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
428 FC_EXCH_DBG(ep, "Exchange timer armed\n");
430 if (schedule_delayed_work(&ep->timeout_work,
431 msecs_to_jiffies(timer_msec)))
432 fc_exch_hold(ep); /* hold for timer */
436 * fc_exch_timer_set() - Lock the exchange and set the timer
437 * @ep: The exchange whose timer will start
438 * @timer_msec: The timeout period
440 static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec)
442 spin_lock_bh(&ep->ex_lock);
443 fc_exch_timer_set_locked(ep, timer_msec);
444 spin_unlock_bh(&ep->ex_lock);
448 * fc_seq_send() - Send a frame using existing sequence/exchange pair
449 * @lport: The local port that the exchange will be sent on
450 * @sp: The sequence to be sent
451 * @fp: The frame to be sent on the exchange
453 static int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp,
457 struct fc_frame_header *fh = fc_frame_header_get(fp);
461 ep = fc_seq_exch(sp);
462 WARN_ON((ep->esb_stat & ESB_ST_SEQ_INIT) != ESB_ST_SEQ_INIT);
464 f_ctl = ntoh24(fh->fh_f_ctl);
465 fc_exch_setup_hdr(ep, fp, f_ctl);
468 * update sequence count if this frame is carrying
469 * multiple FC frames when sequence offload is enabled
472 if (fr_max_payload(fp))
473 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),
481 error = lport->tt.frame_send(lport, fp);
484 * Update the exchange and sequence flags,
485 * assuming all frames for the sequence have been sent.
486 * We can only be called to send once for each sequence.
488 spin_lock_bh(&ep->ex_lock);
489 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
490 if (f_ctl & (FC_FC_END_SEQ | FC_FC_SEQ_INIT))
491 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
492 spin_unlock_bh(&ep->ex_lock);
497 * fc_seq_alloc() - Allocate a sequence for a given exchange
498 * @ep: The exchange to allocate a new sequence for
499 * @seq_id: The sequence ID to be used
501 * We don't support multiple originated sequences on the same exchange.
502 * By implication, any previously originated sequence on this exchange
503 * is complete, and we reallocate the same sequence.
505 static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
517 * fc_seq_start_next_locked() - Allocate a new sequence on the same
518 * exchange as the supplied sequence
519 * @sp: The sequence/exchange to get a new sequence for
521 static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
523 struct fc_exch *ep = fc_seq_exch(sp);
525 sp = fc_seq_alloc(ep, ep->seq_id++);
526 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
532 * fc_seq_start_next() - Lock the exchange and get a new sequence
533 * for a given sequence/exchange pair
534 * @sp: The sequence/exchange to get a new exchange for
536 static struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
538 struct fc_exch *ep = fc_seq_exch(sp);
540 spin_lock_bh(&ep->ex_lock);
541 sp = fc_seq_start_next_locked(sp);
542 spin_unlock_bh(&ep->ex_lock);
548 * fc_seq_exch_abort() - Abort an exchange and sequence
549 * @req_sp: The sequence to be aborted
550 * @timer_msec: The period of time to wait before aborting
552 * Generally called because of a timeout or an abort from the upper layer.
554 static int fc_seq_exch_abort(const struct fc_seq *req_sp,
555 unsigned int timer_msec)
562 ep = fc_seq_exch(req_sp);
564 spin_lock_bh(&ep->ex_lock);
565 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
566 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
567 spin_unlock_bh(&ep->ex_lock);
572 * Send the abort on a new sequence if possible.
574 sp = fc_seq_start_next_locked(&ep->seq);
576 spin_unlock_bh(&ep->ex_lock);
580 ep->esb_stat |= ESB_ST_SEQ_INIT | ESB_ST_ABNORMAL;
582 fc_exch_timer_set_locked(ep, timer_msec);
583 spin_unlock_bh(&ep->ex_lock);
586 * If not logged into the fabric, don't send ABTS but leave
587 * sequence active until next timeout.
593 * Send an abort for the sequence that timed out.
595 fp = fc_frame_alloc(ep->lp, 0);
597 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
598 FC_TYPE_BLS, FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
599 error = fc_seq_send(ep->lp, sp, fp);
606 * fc_exch_timeout() - Handle exchange timer expiration
607 * @work: The work_struct identifying the exchange that timed out
609 static void fc_exch_timeout(struct work_struct *work)
611 struct fc_exch *ep = container_of(work, struct fc_exch,
613 struct fc_seq *sp = &ep->seq;
614 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
619 FC_EXCH_DBG(ep, "Exchange timed out\n");
621 spin_lock_bh(&ep->ex_lock);
622 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
625 e_stat = ep->esb_stat;
626 if (e_stat & ESB_ST_COMPLETE) {
627 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
628 spin_unlock_bh(&ep->ex_lock);
629 if (e_stat & ESB_ST_REC_QUAL)
636 if (e_stat & ESB_ST_ABNORMAL)
637 rc = fc_exch_done_locked(ep);
638 spin_unlock_bh(&ep->ex_lock);
642 resp(sp, ERR_PTR(-FC_EX_TIMEOUT), arg);
643 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
647 spin_unlock_bh(&ep->ex_lock);
650 * This release matches the hold taken when the timer was set.
656 * fc_exch_em_alloc() - Allocate an exchange from a specified EM.
657 * @lport: The local port that the exchange is for
658 * @mp: The exchange manager that will allocate the exchange
660 * Returns pointer to allocated fc_exch with exch lock held.
662 static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
663 struct fc_exch_mgr *mp)
668 struct fc_exch_pool *pool;
670 /* allocate memory for exchange */
671 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);
673 atomic_inc(&mp->stats.no_free_exch);
676 memset(ep, 0, sizeof(*ep));
678 cpu = smp_processor_id();
679 pool = per_cpu_ptr(mp->pool, cpu);
680 spin_lock_bh(&pool->lock);
681 index = pool->next_index;
682 /* allocate new exch from pool */
683 while (fc_exch_ptr_get(pool, index)) {
684 index = index == mp->pool_max_index ? 0 : index + 1;
685 if (index == pool->next_index)
688 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
690 fc_exch_hold(ep); /* hold for exch in mp */
691 spin_lock_init(&ep->ex_lock);
693 * Hold exch lock for caller to prevent fc_exch_reset()
694 * from releasing exch while fc_exch_alloc() caller is
695 * still working on exch.
697 spin_lock_bh(&ep->ex_lock);
699 fc_exch_ptr_set(pool, index, ep);
700 list_add_tail(&ep->ex_list, &pool->ex_list);
701 fc_seq_alloc(ep, ep->seq_id++);
702 pool->total_exches++;
703 spin_unlock_bh(&pool->lock);
708 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
712 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
713 ep->rxid = FC_XID_UNKNOWN;
714 ep->class = mp->class;
715 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
719 spin_unlock_bh(&pool->lock);
720 atomic_inc(&mp->stats.no_free_exch_xid);
721 mempool_free(ep, mp->ep_pool);
726 * fc_exch_alloc() - Allocate an exchange from an EM on a
727 * local port's list of EMs.
728 * @lport: The local port that will own the exchange
729 * @fp: The FC frame that the exchange will be for
731 * This function walks the list of exchange manager(EM)
732 * anchors to select an EM for a new exchange allocation. The
733 * EM is selected when a NULL match function pointer is encountered
734 * or when a call to a match function returns true.
736 static struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
739 struct fc_exch_mgr_anchor *ema;
742 list_for_each_entry(ema, &lport->ema_list, ema_list) {
743 if (!ema->match || ema->match(fp)) {
744 ep = fc_exch_em_alloc(lport, ema->mp);
753 * fc_exch_find() - Lookup and hold an exchange
754 * @mp: The exchange manager to lookup the exchange from
755 * @xid: The XID of the exchange to look up
757 static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
759 struct fc_exch_pool *pool;
760 struct fc_exch *ep = NULL;
762 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
763 pool = per_cpu_ptr(mp->pool, xid & fc_cpu_mask);
764 spin_lock_bh(&pool->lock);
765 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
768 WARN_ON(ep->xid != xid);
770 spin_unlock_bh(&pool->lock);
777 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and
778 * the memory allocated for the related objects may be freed.
779 * @sp: The sequence that has completed
781 static void fc_exch_done(struct fc_seq *sp)
783 struct fc_exch *ep = fc_seq_exch(sp);
786 spin_lock_bh(&ep->ex_lock);
787 rc = fc_exch_done_locked(ep);
788 spin_unlock_bh(&ep->ex_lock);
794 * fc_exch_resp() - Allocate a new exchange for a response frame
795 * @lport: The local port that the exchange was for
796 * @mp: The exchange manager to allocate the exchange from
797 * @fp: The response frame
799 * Sets the responder ID in the frame header.
801 static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
802 struct fc_exch_mgr *mp,
806 struct fc_frame_header *fh;
808 ep = fc_exch_alloc(lport, fp);
810 ep->class = fc_frame_class(fp);
813 * Set EX_CTX indicating we're responding on this exchange.
815 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
816 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
817 fh = fc_frame_header_get(fp);
818 ep->sid = ntoh24(fh->fh_d_id);
819 ep->did = ntoh24(fh->fh_s_id);
823 * Allocated exchange has placed the XID in the
824 * originator field. Move it to the responder field,
825 * and set the originator XID from the frame.
828 ep->oxid = ntohs(fh->fh_ox_id);
829 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
830 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
831 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
833 fc_exch_hold(ep); /* hold for caller */
834 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
840 * fc_seq_lookup_recip() - Find a sequence where the other end
841 * originated the sequence
842 * @lport: The local port that the frame was sent to
843 * @mp: The Exchange Manager to lookup the exchange from
844 * @fp: The frame associated with the sequence we're looking for
846 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
847 * on the ep that should be released by the caller.
849 static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
850 struct fc_exch_mgr *mp,
853 struct fc_frame_header *fh = fc_frame_header_get(fp);
854 struct fc_exch *ep = NULL;
855 struct fc_seq *sp = NULL;
856 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
860 f_ctl = ntoh24(fh->fh_f_ctl);
861 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
864 * Lookup or create the exchange if we will be creating the sequence.
866 if (f_ctl & FC_FC_EX_CTX) {
867 xid = ntohs(fh->fh_ox_id); /* we originated exch */
868 ep = fc_exch_find(mp, xid);
870 atomic_inc(&mp->stats.xid_not_found);
871 reject = FC_RJT_OX_ID;
874 if (ep->rxid == FC_XID_UNKNOWN)
875 ep->rxid = ntohs(fh->fh_rx_id);
876 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
877 reject = FC_RJT_OX_ID;
881 xid = ntohs(fh->fh_rx_id); /* we are the responder */
884 * Special case for MDS issuing an ELS TEST with a
886 * XXX take this out once we do the proper reject.
888 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
889 fc_frame_payload_op(fp) == ELS_TEST) {
890 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
891 xid = FC_XID_UNKNOWN;
895 * new sequence - find the exchange
897 ep = fc_exch_find(mp, xid);
898 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
900 atomic_inc(&mp->stats.xid_busy);
901 reject = FC_RJT_RX_ID;
904 ep = fc_exch_resp(lport, mp, fp);
906 reject = FC_RJT_EXCH_EST; /* XXX */
909 xid = ep->xid; /* get our XID */
911 atomic_inc(&mp->stats.xid_not_found);
912 reject = FC_RJT_RX_ID; /* XID not found */
918 * At this point, we have the exchange held.
919 * Find or create the sequence.
921 if (fc_sof_is_init(fr_sof(fp))) {
922 sp = fc_seq_start_next(&ep->seq);
924 reject = FC_RJT_SEQ_XS; /* exchange shortage */
927 sp->id = fh->fh_seq_id;
928 sp->ssb_stat |= SSB_ST_RESP;
931 if (sp->id != fh->fh_seq_id) {
932 atomic_inc(&mp->stats.seq_not_found);
933 reject = FC_RJT_SEQ_ID; /* sequence/exch should exist */
937 WARN_ON(ep != fc_seq_exch(sp));
939 if (f_ctl & FC_FC_SEQ_INIT)
940 ep->esb_stat |= ESB_ST_SEQ_INIT;
946 fc_exch_done(&ep->seq);
947 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
952 * fc_seq_lookup_orig() - Find a sequence where this end
953 * originated the sequence
954 * @mp: The Exchange Manager to lookup the exchange from
955 * @fp: The frame associated with the sequence we're looking for
957 * Does not hold the sequence for the caller.
959 static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
962 struct fc_frame_header *fh = fc_frame_header_get(fp);
964 struct fc_seq *sp = NULL;
968 f_ctl = ntoh24(fh->fh_f_ctl);
969 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
970 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
971 ep = fc_exch_find(mp, xid);
974 if (ep->seq.id == fh->fh_seq_id) {
976 * Save the RX_ID if we didn't previously know it.
979 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
980 ep->rxid == FC_XID_UNKNOWN) {
981 ep->rxid = ntohs(fh->fh_rx_id);
989 * fc_exch_set_addr() - Set the source and destination IDs for an exchange
990 * @ep: The exchange to set the addresses for
991 * @orig_id: The originator's ID
992 * @resp_id: The responder's ID
994 * Note this must be done before the first sequence of the exchange is sent.
996 static void fc_exch_set_addr(struct fc_exch *ep,
997 u32 orig_id, u32 resp_id)
1000 if (ep->esb_stat & ESB_ST_RESP) {
1010 * fc_seq_els_rsp_send() - Send an ELS response using infomation from
1011 * the existing sequence/exchange.
1012 * @sp: The sequence/exchange to get information from
1013 * @els_cmd: The ELS command to be sent
1014 * @els_data: The ELS data to be sent
1016 static void fc_seq_els_rsp_send(struct fc_seq *sp, enum fc_els_cmd els_cmd,
1017 struct fc_seq_els_data *els_data)
1021 fc_seq_ls_rjt(sp, els_data->reason, els_data->explan);
1027 fc_exch_els_rrq(sp, els_data->fp);
1030 fc_exch_els_rec(sp, els_data->fp);
1033 FC_EXCH_DBG(fc_seq_exch(sp), "Invalid ELS CMD:%x\n", els_cmd);
1038 * fc_seq_send_last() - Send a sequence that is the last in the exchange
1039 * @sp: The sequence that is to be sent
1040 * @fp: The frame that will be sent on the sequence
1041 * @rctl: The R_CTL information to be sent
1042 * @fh_type: The frame header type
1044 static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
1045 enum fc_rctl rctl, enum fc_fh_type fh_type)
1048 struct fc_exch *ep = fc_seq_exch(sp);
1050 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
1052 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
1053 fc_seq_send(ep->lp, sp, fp);
1057 * fc_seq_send_ack() - Send an acknowledgement that we've received a frame
1058 * @sp: The sequence to send the ACK on
1059 * @rx_fp: The received frame that is being acknoledged
1061 * Send ACK_1 (or equiv.) indicating we received something.
1063 static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
1065 struct fc_frame *fp;
1066 struct fc_frame_header *rx_fh;
1067 struct fc_frame_header *fh;
1068 struct fc_exch *ep = fc_seq_exch(sp);
1069 struct fc_lport *lport = ep->lp;
1073 * Don't send ACKs for class 3.
1075 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
1076 fp = fc_frame_alloc(lport, 0);
1080 fh = fc_frame_header_get(fp);
1081 fh->fh_r_ctl = FC_RCTL_ACK_1;
1082 fh->fh_type = FC_TYPE_BLS;
1085 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1086 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1087 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1088 * Last ACK uses bits 7-6 (continue sequence),
1089 * bits 5-4 are meaningful (what kind of ACK to use).
1091 rx_fh = fc_frame_header_get(rx_fp);
1092 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1093 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1094 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
1095 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
1096 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1097 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1098 hton24(fh->fh_f_ctl, f_ctl);
1100 fc_exch_setup_hdr(ep, fp, f_ctl);
1101 fh->fh_seq_id = rx_fh->fh_seq_id;
1102 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1103 fh->fh_parm_offset = htonl(1); /* ack single frame */
1105 fr_sof(fp) = fr_sof(rx_fp);
1106 if (f_ctl & FC_FC_END_SEQ)
1107 fr_eof(fp) = FC_EOF_T;
1109 fr_eof(fp) = FC_EOF_N;
1111 lport->tt.frame_send(lport, fp);
1116 * fc_exch_send_ba_rjt() - Send BLS Reject
1117 * @rx_fp: The frame being rejected
1118 * @reason: The reason the frame is being rejected
1119 * @explan: The explaination for the rejection
1121 * This is for rejecting BA_ABTS only.
1123 static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
1124 enum fc_ba_rjt_reason reason,
1125 enum fc_ba_rjt_explan explan)
1127 struct fc_frame *fp;
1128 struct fc_frame_header *rx_fh;
1129 struct fc_frame_header *fh;
1130 struct fc_ba_rjt *rp;
1131 struct fc_lport *lport;
1134 lport = fr_dev(rx_fp);
1135 fp = fc_frame_alloc(lport, sizeof(*rp));
1138 fh = fc_frame_header_get(fp);
1139 rx_fh = fc_frame_header_get(rx_fp);
1141 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1143 rp = fc_frame_payload_get(fp, sizeof(*rp));
1144 rp->br_reason = reason;
1145 rp->br_explan = explan;
1148 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1150 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1151 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1152 fh->fh_ox_id = rx_fh->fh_ox_id;
1153 fh->fh_rx_id = rx_fh->fh_rx_id;
1154 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1155 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1156 fh->fh_type = FC_TYPE_BLS;
1159 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1160 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1161 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1162 * Last ACK uses bits 7-6 (continue sequence),
1163 * bits 5-4 are meaningful (what kind of ACK to use).
1164 * Always set LAST_SEQ, END_SEQ.
1166 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1167 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1168 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1169 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1170 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1171 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1172 f_ctl &= ~FC_FC_FIRST_SEQ;
1173 hton24(fh->fh_f_ctl, f_ctl);
1175 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1176 fr_eof(fp) = FC_EOF_T;
1177 if (fc_sof_needs_ack(fr_sof(fp)))
1178 fr_eof(fp) = FC_EOF_N;
1180 lport->tt.frame_send(lport, fp);
1184 * fc_exch_recv_abts() - Handle an incoming ABTS
1185 * @ep: The exchange the abort was on
1186 * @rx_fp: The ABTS frame
1188 * This would be for target mode usually, but could be due to lost
1189 * FCP transfer ready, confirm or RRQ. We always handle this as an
1190 * exchange abort, ignoring the parameter.
1192 static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1194 struct fc_frame *fp;
1195 struct fc_ba_acc *ap;
1196 struct fc_frame_header *fh;
1201 spin_lock_bh(&ep->ex_lock);
1202 if (ep->esb_stat & ESB_ST_COMPLETE) {
1203 spin_unlock_bh(&ep->ex_lock);
1206 if (!(ep->esb_stat & ESB_ST_REC_QUAL))
1207 fc_exch_hold(ep); /* hold for REC_QUAL */
1208 ep->esb_stat |= ESB_ST_ABNORMAL | ESB_ST_REC_QUAL;
1209 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1211 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1213 spin_unlock_bh(&ep->ex_lock);
1216 fh = fc_frame_header_get(fp);
1217 ap = fc_frame_payload_get(fp, sizeof(*ap));
1218 memset(ap, 0, sizeof(*ap));
1220 ap->ba_high_seq_cnt = htons(0xffff);
1221 if (sp->ssb_stat & SSB_ST_RESP) {
1222 ap->ba_seq_id = sp->id;
1223 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1224 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1225 ap->ba_low_seq_cnt = htons(sp->cnt);
1227 sp = fc_seq_start_next_locked(sp);
1228 spin_unlock_bh(&ep->ex_lock);
1229 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1230 fc_frame_free(rx_fp);
1234 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1236 fc_frame_free(rx_fp);
1240 * fc_exch_recv_req() - Handler for an incoming request where is other
1241 * end is originating the sequence
1242 * @lport: The local port that received the request
1243 * @mp: The EM that the exchange is on
1244 * @fp: The request frame
1246 static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp,
1247 struct fc_frame *fp)
1249 struct fc_frame_header *fh = fc_frame_header_get(fp);
1250 struct fc_seq *sp = NULL;
1251 struct fc_exch *ep = NULL;
1255 enum fc_pf_rjt_reason reject;
1257 /* We can have the wrong fc_lport at this point with NPIV, which is a
1258 * problem now that we know a new exchange needs to be allocated
1260 lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id));
1267 reject = fc_seq_lookup_recip(lport, mp, fp);
1268 if (reject == FC_RJT_NONE) {
1269 sp = fr_seq(fp); /* sequence will be held */
1270 ep = fc_seq_exch(sp);
1273 f_ctl = ntoh24(fh->fh_f_ctl);
1274 fc_seq_send_ack(sp, fp);
1277 * Call the receive function.
1279 * The receive function may allocate a new sequence
1280 * over the old one, so we shouldn't change the
1281 * sequence after this.
1283 * The frame will be freed by the receive function.
1284 * If new exch resp handler is valid then call that
1288 ep->resp(sp, fp, ep->arg);
1290 lport->tt.lport_recv(lport, sp, fp);
1291 fc_exch_release(ep); /* release from lookup */
1293 FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n",
1300 * fc_exch_recv_seq_resp() - Handler for an incoming response where the other
1301 * end is the originator of the sequence that is a
1302 * response to our initial exchange
1303 * @mp: The EM that the exchange is on
1304 * @fp: The response frame
1306 static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1308 struct fc_frame_header *fh = fc_frame_header_get(fp);
1313 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
1317 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1319 atomic_inc(&mp->stats.xid_not_found);
1322 if (ep->esb_stat & ESB_ST_COMPLETE) {
1323 atomic_inc(&mp->stats.xid_not_found);
1326 if (ep->rxid == FC_XID_UNKNOWN)
1327 ep->rxid = ntohs(fh->fh_rx_id);
1328 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1329 atomic_inc(&mp->stats.xid_not_found);
1332 if (ep->did != ntoh24(fh->fh_s_id) &&
1333 ep->did != FC_FID_FLOGI) {
1334 atomic_inc(&mp->stats.xid_not_found);
1338 if (fc_sof_is_init(sof)) {
1339 sp = fc_seq_start_next(&ep->seq);
1340 sp->id = fh->fh_seq_id;
1341 sp->ssb_stat |= SSB_ST_RESP;
1344 if (sp->id != fh->fh_seq_id) {
1345 atomic_inc(&mp->stats.seq_not_found);
1349 f_ctl = ntoh24(fh->fh_f_ctl);
1351 if (f_ctl & FC_FC_SEQ_INIT)
1352 ep->esb_stat |= ESB_ST_SEQ_INIT;
1354 if (fc_sof_needs_ack(sof))
1355 fc_seq_send_ack(sp, fp);
1357 ex_resp_arg = ep->arg;
1359 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1360 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1361 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1362 spin_lock_bh(&ep->ex_lock);
1363 rc = fc_exch_done_locked(ep);
1364 WARN_ON(fc_seq_exch(sp) != ep);
1365 spin_unlock_bh(&ep->ex_lock);
1371 * Call the receive function.
1372 * The sequence is held (has a refcnt) for us,
1373 * but not for the receive function.
1375 * The receive function may allocate a new sequence
1376 * over the old one, so we shouldn't change the
1377 * sequence after this.
1379 * The frame will be freed by the receive function.
1380 * If new exch resp handler is valid then call that
1384 resp(sp, fp, ex_resp_arg);
1387 fc_exch_release(ep);
1390 fc_exch_release(ep);
1396 * fc_exch_recv_resp() - Handler for a sequence where other end is
1397 * responding to our sequence
1398 * @mp: The EM that the exchange is on
1399 * @fp: The response frame
1401 static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1405 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1408 atomic_inc(&mp->stats.xid_not_found);
1410 atomic_inc(&mp->stats.non_bls_resp);
1416 * fc_exch_abts_resp() - Handler for a response to an ABT
1417 * @ep: The exchange that the frame is on
1418 * @fp: The response frame
1420 * This response would be to an ABTS cancelling an exchange or sequence.
1421 * The response can be either BA_ACC or BA_RJT
1423 static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1425 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
1427 struct fc_frame_header *fh;
1428 struct fc_ba_acc *ap;
1432 int rc = 1, has_rec = 0;
1434 fh = fc_frame_header_get(fp);
1435 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1436 fc_exch_rctl_name(fh->fh_r_ctl));
1438 if (cancel_delayed_work_sync(&ep->timeout_work))
1439 fc_exch_release(ep); /* release from pending timer hold */
1441 spin_lock_bh(&ep->ex_lock);
1442 switch (fh->fh_r_ctl) {
1443 case FC_RCTL_BA_ACC:
1444 ap = fc_frame_payload_get(fp, sizeof(*ap));
1449 * Decide whether to establish a Recovery Qualifier.
1450 * We do this if there is a non-empty SEQ_CNT range and
1451 * SEQ_ID is the same as the one we aborted.
1453 low = ntohs(ap->ba_low_seq_cnt);
1454 high = ntohs(ap->ba_high_seq_cnt);
1455 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1456 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1457 ap->ba_seq_id == ep->seq_id) && low != high) {
1458 ep->esb_stat |= ESB_ST_REC_QUAL;
1459 fc_exch_hold(ep); /* hold for recovery qualifier */
1463 case FC_RCTL_BA_RJT:
1470 ex_resp_arg = ep->arg;
1472 /* do we need to do some other checks here. Can we reuse more of
1473 * fc_exch_recv_seq_resp
1477 * do we want to check END_SEQ as well as LAST_SEQ here?
1479 if (ep->fh_type != FC_TYPE_FCP &&
1480 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1481 rc = fc_exch_done_locked(ep);
1482 spin_unlock_bh(&ep->ex_lock);
1487 resp(sp, fp, ex_resp_arg);
1492 fc_exch_timer_set(ep, ep->r_a_tov);
1497 * fc_exch_recv_bls() - Handler for a BLS sequence
1498 * @mp: The EM that the exchange is on
1499 * @fp: The request frame
1501 * The BLS frame is always a sequence initiated by the remote side.
1502 * We may be either the originator or recipient of the exchange.
1504 static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1506 struct fc_frame_header *fh;
1510 fh = fc_frame_header_get(fp);
1511 f_ctl = ntoh24(fh->fh_f_ctl);
1514 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1515 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1516 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1517 spin_lock_bh(&ep->ex_lock);
1518 ep->esb_stat |= ESB_ST_SEQ_INIT;
1519 spin_unlock_bh(&ep->ex_lock);
1521 if (f_ctl & FC_FC_SEQ_CTX) {
1523 * A response to a sequence we initiated.
1524 * This should only be ACKs for class 2 or F.
1526 switch (fh->fh_r_ctl) {
1531 FC_EXCH_DBG(ep, "BLS rctl %x - %s received",
1533 fc_exch_rctl_name(fh->fh_r_ctl));
1538 switch (fh->fh_r_ctl) {
1539 case FC_RCTL_BA_RJT:
1540 case FC_RCTL_BA_ACC:
1542 fc_exch_abts_resp(ep, fp);
1546 case FC_RCTL_BA_ABTS:
1547 fc_exch_recv_abts(ep, fp);
1549 default: /* ignore junk */
1555 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1559 * fc_seq_ls_acc() - Accept sequence with LS_ACC
1560 * @req_sp: The request sequence
1562 * If this fails due to allocation or transmit congestion, assume the
1563 * originator will repeat the sequence.
1565 static void fc_seq_ls_acc(struct fc_seq *req_sp)
1568 struct fc_els_ls_acc *acc;
1569 struct fc_frame *fp;
1571 sp = fc_seq_start_next(req_sp);
1572 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*acc));
1574 acc = fc_frame_payload_get(fp, sizeof(*acc));
1575 memset(acc, 0, sizeof(*acc));
1576 acc->la_cmd = ELS_LS_ACC;
1577 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1582 * fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT
1583 * @req_sp: The request sequence
1584 * @reason: The reason the sequence is being rejected
1585 * @explan: The explaination for the rejection
1587 * If this fails due to allocation or transmit congestion, assume the
1588 * originator will repeat the sequence.
1590 static void fc_seq_ls_rjt(struct fc_seq *req_sp, enum fc_els_rjt_reason reason,
1591 enum fc_els_rjt_explan explan)
1594 struct fc_els_ls_rjt *rjt;
1595 struct fc_frame *fp;
1597 sp = fc_seq_start_next(req_sp);
1598 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*rjt));
1600 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1601 memset(rjt, 0, sizeof(*rjt));
1602 rjt->er_cmd = ELS_LS_RJT;
1603 rjt->er_reason = reason;
1604 rjt->er_explan = explan;
1605 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1610 * fc_exch_reset() - Reset an exchange
1611 * @ep: The exchange to be reset
1613 static void fc_exch_reset(struct fc_exch *ep)
1616 void (*resp)(struct fc_seq *, struct fc_frame *, void *);
1620 spin_lock_bh(&ep->ex_lock);
1621 ep->state |= FC_EX_RST_CLEANUP;
1623 * we really want to call del_timer_sync, but cannot due
1624 * to the lport calling with the lport lock held (some resp
1625 * functions can also grab the lport lock which could cause
1628 if (cancel_delayed_work(&ep->timeout_work))
1629 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
1632 if (ep->esb_stat & ESB_ST_REC_QUAL)
1633 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1634 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1637 rc = fc_exch_done_locked(ep);
1638 spin_unlock_bh(&ep->ex_lock);
1643 resp(sp, ERR_PTR(-FC_EX_CLOSED), arg);
1647 * fc_exch_pool_reset() - Reset a per cpu exchange pool
1648 * @lport: The local port that the exchange pool is on
1649 * @pool: The exchange pool to be reset
1650 * @sid: The source ID
1651 * @did: The destination ID
1653 * Resets a per cpu exches pool, releasing all of its sequences
1654 * and exchanges. If sid is non-zero then reset only exchanges
1655 * we sourced from the local port's FID. If did is non-zero then
1656 * only reset exchanges destined for the local port's FID.
1658 static void fc_exch_pool_reset(struct fc_lport *lport,
1659 struct fc_exch_pool *pool,
1663 struct fc_exch *next;
1665 spin_lock_bh(&pool->lock);
1667 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1668 if ((lport == ep->lp) &&
1669 (sid == 0 || sid == ep->sid) &&
1670 (did == 0 || did == ep->did)) {
1672 spin_unlock_bh(&pool->lock);
1676 fc_exch_release(ep);
1677 spin_lock_bh(&pool->lock);
1680 * must restart loop incase while lock
1681 * was down multiple eps were released.
1686 spin_unlock_bh(&pool->lock);
1690 * fc_exch_mgr_reset() - Reset all EMs of a local port
1691 * @lport: The local port whose EMs are to be reset
1692 * @sid: The source ID
1693 * @did: The destination ID
1695 * Reset all EMs associated with a given local port. Release all
1696 * sequences and exchanges. If sid is non-zero then reset only the
1697 * exchanges sent from the local port's FID. If did is non-zero then
1698 * reset only exchanges destined for the local port's FID.
1700 void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1702 struct fc_exch_mgr_anchor *ema;
1705 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1706 for_each_possible_cpu(cpu)
1707 fc_exch_pool_reset(lport,
1708 per_cpu_ptr(ema->mp->pool, cpu),
1712 EXPORT_SYMBOL(fc_exch_mgr_reset);
1715 * fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests
1716 * @sp: The sequence the REC is on
1717 * @rfp: The REC frame
1719 * Note that the requesting port may be different than the S_ID in the request.
1721 static void fc_exch_els_rec(struct fc_seq *sp, struct fc_frame *rfp)
1723 struct fc_frame *fp;
1725 struct fc_exch_mgr *em;
1726 struct fc_els_rec *rp;
1727 struct fc_els_rec_acc *acc;
1728 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
1729 enum fc_els_rjt_explan explan;
1734 rp = fc_frame_payload_get(rfp, sizeof(*rp));
1735 explan = ELS_EXPL_INV_LEN;
1738 sid = ntoh24(rp->rec_s_id);
1739 rxid = ntohs(rp->rec_rx_id);
1740 oxid = ntohs(rp->rec_ox_id);
1743 * Currently it's hard to find the local S_ID from the exchange
1744 * manager. This will eventually be fixed, but for now it's easier
1745 * to lookup the subject exchange twice, once as if we were
1746 * the initiator, and then again if we weren't.
1748 em = fc_seq_exch(sp)->em;
1749 ep = fc_exch_find(em, oxid);
1750 explan = ELS_EXPL_OXID_RXID;
1751 if (ep && ep->oid == sid) {
1752 if (ep->rxid != FC_XID_UNKNOWN &&
1753 rxid != FC_XID_UNKNOWN &&
1758 fc_exch_release(ep);
1760 if (rxid != FC_XID_UNKNOWN)
1761 ep = fc_exch_find(em, rxid);
1766 fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*acc));
1771 sp = fc_seq_start_next(sp);
1772 acc = fc_frame_payload_get(fp, sizeof(*acc));
1773 memset(acc, 0, sizeof(*acc));
1774 acc->reca_cmd = ELS_LS_ACC;
1775 acc->reca_ox_id = rp->rec_ox_id;
1776 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
1777 acc->reca_rx_id = htons(ep->rxid);
1778 if (ep->sid == ep->oid)
1779 hton24(acc->reca_rfid, ep->did);
1781 hton24(acc->reca_rfid, ep->sid);
1782 acc->reca_fc4value = htonl(ep->seq.rec_data);
1783 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
1786 sp = fc_seq_start_next(sp);
1787 fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
1789 fc_exch_release(ep);
1794 fc_exch_release(ep);
1796 fc_seq_ls_rjt(sp, reason, explan);
1801 * fc_exch_rrq_resp() - Handler for RRQ responses
1802 * @sp: The sequence that the RRQ is on
1803 * @fp: The RRQ frame
1804 * @arg: The exchange that the RRQ is on
1806 * TODO: fix error handler.
1808 static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
1810 struct fc_exch *aborted_ep = arg;
1814 int err = PTR_ERR(fp);
1816 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
1818 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
1819 "frame error %d\n", err);
1823 op = fc_frame_payload_op(fp);
1828 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ");
1833 FC_EXCH_DBG(aborted_ep, "unexpected response op %x "
1839 fc_exch_done(&aborted_ep->seq);
1840 /* drop hold for rec qual */
1841 fc_exch_release(aborted_ep);
1846 * fc_exch_seq_send() - Send a frame using a new exchange and sequence
1847 * @lport: The local port to send the frame on
1848 * @fp: The frame to be sent
1849 * @resp: The response handler for this request
1850 * @destructor: The destructor for the exchange
1851 * @arg: The argument to be passed to the response handler
1852 * @timer_msec: The timeout period for the exchange
1854 * The frame pointer with some of the header's fields must be
1855 * filled before calling this routine, those fields are:
1862 * - parameter or relative offset
1864 static struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
1865 struct fc_frame *fp,
1866 void (*resp)(struct fc_seq *,
1867 struct fc_frame *fp,
1869 void (*destructor)(struct fc_seq *,
1871 void *arg, u32 timer_msec)
1874 struct fc_seq *sp = NULL;
1875 struct fc_frame_header *fh;
1878 ep = fc_exch_alloc(lport, fp);
1883 ep->esb_stat |= ESB_ST_SEQ_INIT;
1884 fh = fc_frame_header_get(fp);
1885 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
1887 ep->destructor = destructor;
1889 ep->r_a_tov = FC_DEF_R_A_TOV;
1893 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
1894 ep->f_ctl = ntoh24(fh->fh_f_ctl);
1895 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
1898 if (ep->xid <= lport->lro_xid)
1899 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
1901 if (unlikely(lport->tt.frame_send(lport, fp)))
1905 fc_exch_timer_set_locked(ep, timer_msec);
1906 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
1908 if (ep->f_ctl & FC_FC_SEQ_INIT)
1909 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
1910 spin_unlock_bh(&ep->ex_lock);
1913 rc = fc_exch_done_locked(ep);
1914 spin_unlock_bh(&ep->ex_lock);
1921 * fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command
1922 * @ep: The exchange to send the RRQ on
1924 * This tells the remote port to stop blocking the use of
1925 * the exchange and the seq_cnt range.
1927 static void fc_exch_rrq(struct fc_exch *ep)
1929 struct fc_lport *lport;
1930 struct fc_els_rrq *rrq;
1931 struct fc_frame *fp;
1936 fp = fc_frame_alloc(lport, sizeof(*rrq));
1940 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
1941 memset(rrq, 0, sizeof(*rrq));
1942 rrq->rrq_cmd = ELS_RRQ;
1943 hton24(rrq->rrq_s_id, ep->sid);
1944 rrq->rrq_ox_id = htons(ep->oxid);
1945 rrq->rrq_rx_id = htons(ep->rxid);
1948 if (ep->esb_stat & ESB_ST_RESP)
1951 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
1952 fc_host_port_id(lport->host), FC_TYPE_ELS,
1953 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1955 if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep,
1960 spin_lock_bh(&ep->ex_lock);
1961 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
1962 spin_unlock_bh(&ep->ex_lock);
1963 /* drop hold for rec qual */
1964 fc_exch_release(ep);
1967 ep->esb_stat |= ESB_ST_REC_QUAL;
1968 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1969 spin_unlock_bh(&ep->ex_lock);
1974 * fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests
1975 * @sp: The sequence that the RRQ is on
1976 * @fp: The RRQ frame
1978 static void fc_exch_els_rrq(struct fc_seq *sp, struct fc_frame *fp)
1980 struct fc_exch *ep = NULL; /* request or subject exchange */
1981 struct fc_els_rrq *rp;
1984 enum fc_els_rjt_explan explan;
1986 rp = fc_frame_payload_get(fp, sizeof(*rp));
1987 explan = ELS_EXPL_INV_LEN;
1992 * lookup subject exchange.
1994 ep = fc_seq_exch(sp);
1995 sid = ntoh24(rp->rrq_s_id); /* subject source */
1996 xid = ep->did == sid ? ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
1997 ep = fc_exch_find(ep->em, xid);
1999 explan = ELS_EXPL_OXID_RXID;
2002 spin_lock_bh(&ep->ex_lock);
2003 if (ep->oxid != ntohs(rp->rrq_ox_id))
2005 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
2006 ep->rxid != FC_XID_UNKNOWN)
2008 explan = ELS_EXPL_SID;
2013 * Clear Recovery Qualifier state, and cancel timer if complete.
2015 if (ep->esb_stat & ESB_ST_REC_QUAL) {
2016 ep->esb_stat &= ~ESB_ST_REC_QUAL;
2017 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
2019 if (ep->esb_stat & ESB_ST_COMPLETE) {
2020 if (cancel_delayed_work(&ep->timeout_work))
2021 atomic_dec(&ep->ex_refcnt); /* drop timer hold */
2024 spin_unlock_bh(&ep->ex_lock);
2033 spin_unlock_bh(&ep->ex_lock);
2035 fc_seq_ls_rjt(sp, ELS_RJT_LOGIC, explan);
2039 fc_exch_release(ep); /* drop hold from fc_exch_find */
2043 * fc_exch_mgr_add() - Add an exchange manager to a local port's list of EMs
2044 * @lport: The local port to add the exchange manager to
2045 * @mp: The exchange manager to be added to the local port
2046 * @match: The match routine that indicates when this EM should be used
2048 struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
2049 struct fc_exch_mgr *mp,
2050 bool (*match)(struct fc_frame *))
2052 struct fc_exch_mgr_anchor *ema;
2054 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
2060 /* add EM anchor to EM anchors list */
2061 list_add_tail(&ema->ema_list, &lport->ema_list);
2062 kref_get(&mp->kref);
2065 EXPORT_SYMBOL(fc_exch_mgr_add);
2068 * fc_exch_mgr_destroy() - Destroy an exchange manager
2069 * @kref: The reference to the EM to be destroyed
2071 static void fc_exch_mgr_destroy(struct kref *kref)
2073 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
2075 mempool_destroy(mp->ep_pool);
2076 free_percpu(mp->pool);
2081 * fc_exch_mgr_del() - Delete an EM from a local port's list
2082 * @ema: The exchange manager anchor identifying the EM to be deleted
2084 void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
2086 /* remove EM anchor from EM anchors list */
2087 list_del(&ema->ema_list);
2088 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
2091 EXPORT_SYMBOL(fc_exch_mgr_del);
2094 * fc_exch_mgr_list_clone() - Share all exchange manager objects
2095 * @src: Source lport to clone exchange managers from
2096 * @dst: New lport that takes references to all the exchange managers
2098 int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)
2100 struct fc_exch_mgr_anchor *ema, *tmp;
2102 list_for_each_entry(ema, &src->ema_list, ema_list) {
2103 if (!fc_exch_mgr_add(dst, ema->mp, ema->match))
2108 list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)
2109 fc_exch_mgr_del(ema);
2114 * fc_exch_mgr_alloc() - Allocate an exchange manager
2115 * @lport: The local port that the new EM will be associated with
2116 * @class: The default FC class for new exchanges
2117 * @min_xid: The minimum XID for exchanges from the new EM
2118 * @max_xid: The maximum XID for exchanges from the new EM
2119 * @match: The match routine for the new EM
2121 struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport,
2122 enum fc_class class,
2123 u16 min_xid, u16 max_xid,
2124 bool (*match)(struct fc_frame *))
2126 struct fc_exch_mgr *mp;
2127 u16 pool_exch_range;
2130 struct fc_exch_pool *pool;
2132 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
2133 (min_xid & fc_cpu_mask) != 0) {
2134 FC_LPORT_DBG(lport, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
2140 * allocate memory for EM
2142 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
2147 /* adjust em exch xid range for offload */
2148 mp->min_xid = min_xid;
2149 mp->max_xid = max_xid;
2151 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
2156 * Setup per cpu exch pool with entire exchange id range equally
2157 * divided across all cpus. The exch pointers array memory is
2158 * allocated for exch range per pool.
2160 pool_exch_range = (mp->max_xid - mp->min_xid + 1) / (fc_cpu_mask + 1);
2161 mp->pool_max_index = pool_exch_range - 1;
2164 * Allocate and initialize per cpu exch pool
2166 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
2167 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
2170 for_each_possible_cpu(cpu) {
2171 pool = per_cpu_ptr(mp->pool, cpu);
2172 spin_lock_init(&pool->lock);
2173 INIT_LIST_HEAD(&pool->ex_list);
2176 kref_init(&mp->kref);
2177 if (!fc_exch_mgr_add(lport, mp, match)) {
2178 free_percpu(mp->pool);
2183 * Above kref_init() sets mp->kref to 1 and then
2184 * call to fc_exch_mgr_add incremented mp->kref again,
2185 * so adjust that extra increment.
2187 kref_put(&mp->kref, fc_exch_mgr_destroy);
2191 mempool_destroy(mp->ep_pool);
2196 EXPORT_SYMBOL(fc_exch_mgr_alloc);
2199 * fc_exch_mgr_free() - Free all exchange managers on a local port
2200 * @lport: The local port whose EMs are to be freed
2202 void fc_exch_mgr_free(struct fc_lport *lport)
2204 struct fc_exch_mgr_anchor *ema, *next;
2206 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
2207 fc_exch_mgr_del(ema);
2209 EXPORT_SYMBOL(fc_exch_mgr_free);
2212 * fc_exch_recv() - Handler for received frames
2213 * @lport: The local port the frame was received on
2214 * @fp: The received frame
2216 void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)
2218 struct fc_frame_header *fh = fc_frame_header_get(fp);
2219 struct fc_exch_mgr_anchor *ema;
2220 u32 f_ctl, found = 0;
2224 if (!lport || lport->state == LPORT_ST_DISABLED) {
2225 FC_LPORT_DBG(lport, "Receiving frames for an lport that "
2226 "has not been initialized correctly\n");
2231 f_ctl = ntoh24(fh->fh_f_ctl);
2232 oxid = ntohs(fh->fh_ox_id);
2233 if (f_ctl & FC_FC_EX_CTX) {
2234 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2235 if ((oxid >= ema->mp->min_xid) &&
2236 (oxid <= ema->mp->max_xid)) {
2243 FC_LPORT_DBG(lport, "Received response for out "
2244 "of range oxid:%hx\n", oxid);
2249 ema = list_entry(lport->ema_list.prev, typeof(*ema), ema_list);
2252 * If frame is marked invalid, just drop it.
2254 switch (fr_eof(fp)) {
2256 if (f_ctl & FC_FC_END_SEQ)
2257 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2260 if (fh->fh_type == FC_TYPE_BLS)
2261 fc_exch_recv_bls(ema->mp, fp);
2262 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2264 fc_exch_recv_seq_resp(ema->mp, fp);
2265 else if (f_ctl & FC_FC_SEQ_CTX)
2266 fc_exch_recv_resp(ema->mp, fp);
2268 fc_exch_recv_req(lport, ema->mp, fp);
2271 FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)",
2276 EXPORT_SYMBOL(fc_exch_recv);
2279 * fc_exch_init() - Initialize the exchange layer for a local port
2280 * @lport: The local port to initialize the exchange layer for
2282 int fc_exch_init(struct fc_lport *lport)
2284 if (!lport->tt.seq_start_next)
2285 lport->tt.seq_start_next = fc_seq_start_next;
2287 if (!lport->tt.exch_seq_send)
2288 lport->tt.exch_seq_send = fc_exch_seq_send;
2290 if (!lport->tt.seq_send)
2291 lport->tt.seq_send = fc_seq_send;
2293 if (!lport->tt.seq_els_rsp_send)
2294 lport->tt.seq_els_rsp_send = fc_seq_els_rsp_send;
2296 if (!lport->tt.exch_done)
2297 lport->tt.exch_done = fc_exch_done;
2299 if (!lport->tt.exch_mgr_reset)
2300 lport->tt.exch_mgr_reset = fc_exch_mgr_reset;
2302 if (!lport->tt.seq_exch_abort)
2303 lport->tt.seq_exch_abort = fc_seq_exch_abort;
2307 EXPORT_SYMBOL(fc_exch_init);
2310 * fc_setup_exch_mgr() - Setup an exchange manager
2312 int fc_setup_exch_mgr()
2314 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2315 0, SLAB_HWCACHE_ALIGN, NULL);
2320 * Initialize fc_cpu_mask and fc_cpu_order. The
2321 * fc_cpu_mask is set for nr_cpu_ids rounded up
2322 * to order of 2's * power and order is stored
2323 * in fc_cpu_order as this is later required in
2324 * mapping between an exch id and exch array index
2325 * in per cpu exch pool.
2327 * This round up is required to align fc_cpu_mask
2328 * to exchange id's lower bits such that all incoming
2329 * frames of an exchange gets delivered to the same
2330 * cpu on which exchange originated by simple bitwise
2331 * AND operation between fc_cpu_mask and exchange id.
2335 while (fc_cpu_mask < nr_cpu_ids) {
2345 * fc_destroy_exch_mgr() - Destroy an exchange manager
2347 void fc_destroy_exch_mgr()
2349 kmem_cache_destroy(fc_em_cachep);