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>
29 #include <linux/export.h>
30 #include <linux/log2.h>
32 #include <scsi/fc/fc_fc2.h>
34 #include <scsi/libfc.h>
35 #include <scsi/fc_encode.h>
39 u16 fc_cpu_mask; /* cpu mask for possible cpus */
40 EXPORT_SYMBOL(fc_cpu_mask);
41 static u16 fc_cpu_order; /* 2's power to represent total possible cpus */
42 static struct kmem_cache *fc_em_cachep; /* cache for exchanges */
43 static struct workqueue_struct *fc_exch_workqueue;
46 * Structure and function definitions for managing Fibre Channel Exchanges
49 * The three primary structures used here are fc_exch_mgr, fc_exch, and fc_seq.
51 * fc_exch_mgr holds the exchange state for an N port
53 * fc_exch holds state for one exchange and links to its active sequence.
55 * fc_seq holds the state for an individual sequence.
59 * struct fc_exch_pool - Per cpu exchange pool
60 * @next_index: Next possible free exchange index
61 * @total_exches: Total allocated exchanges
62 * @lock: Exch pool lock
63 * @ex_list: List of exchanges
65 * This structure manages per cpu exchanges in array of exchange pointers.
66 * This array is allocated followed by struct fc_exch_pool memory for
67 * assigned range of exchanges to per cpu pool.
71 struct list_head ex_list;
75 /* two cache of free slot in exch array */
78 } ____cacheline_aligned_in_smp;
81 * struct fc_exch_mgr - The Exchange Manager (EM).
82 * @class: Default class for new sequences
83 * @kref: Reference counter
84 * @min_xid: Minimum exchange ID
85 * @max_xid: Maximum exchange ID
86 * @ep_pool: Reserved exchange pointers
87 * @pool_max_index: Max exch array index in exch pool
88 * @pool: Per cpu exch pool
89 * @stats: Statistics structure
91 * This structure is the center for creating exchanges and sequences.
92 * It manages the allocation of exchange IDs.
95 struct fc_exch_pool __percpu *pool;
104 atomic_t no_free_exch;
105 atomic_t no_free_exch_xid;
106 atomic_t xid_not_found;
108 atomic_t seq_not_found;
109 atomic_t non_bls_resp;
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 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_frame *);
133 static void fc_seq_ls_rjt(struct fc_frame *, enum fc_els_rjt_reason,
134 enum fc_els_rjt_explan);
135 static void fc_exch_els_rec(struct fc_frame *);
136 static void fc_exch_els_rrq(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;
223 * fc_exch_name_lookup() - Lookup name by opcode
224 * @op: Opcode to be looked up
225 * @table: Opcode/name table
226 * @max_index: Index not to be exceeded
228 * This routine is used to determine a human-readable string identifying
231 static inline const char *fc_exch_name_lookup(unsigned int op, char **table,
232 unsigned int max_index)
234 const char *name = NULL;
244 * fc_exch_rctl_name() - Wrapper routine for fc_exch_name_lookup()
245 * @op: The opcode to be looked up
247 static const char *fc_exch_rctl_name(unsigned int op)
249 return fc_exch_name_lookup(op, fc_exch_rctl_names,
250 ARRAY_SIZE(fc_exch_rctl_names));
254 * fc_exch_hold() - Increment an exchange's reference count
255 * @ep: Echange to be held
257 static inline void fc_exch_hold(struct fc_exch *ep)
259 atomic_inc(&ep->ex_refcnt);
263 * fc_exch_setup_hdr() - Initialize a FC header by initializing some fields
264 * and determine SOF and EOF.
265 * @ep: The exchange to that will use the header
266 * @fp: The frame whose header is to be modified
267 * @f_ctl: F_CTL bits that will be used for the frame header
269 * The fields initialized by this routine are: fh_ox_id, fh_rx_id,
270 * fh_seq_id, fh_seq_cnt and the SOF and EOF.
272 static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,
275 struct fc_frame_header *fh = fc_frame_header_get(fp);
278 fr_sof(fp) = ep->class;
280 fr_sof(fp) = fc_sof_normal(ep->class);
282 if (f_ctl & FC_FC_END_SEQ) {
283 fr_eof(fp) = FC_EOF_T;
284 if (fc_sof_needs_ack(ep->class))
285 fr_eof(fp) = FC_EOF_N;
288 * The number of fill bytes to make the length a 4-byte
289 * multiple is the low order 2-bits of the f_ctl.
290 * The fill itself will have been cleared by the frame
292 * After this, the length will be even, as expected by
295 fill = fr_len(fp) & 3;
298 /* TODO, this may be a problem with fragmented skb */
299 skb_put(fp_skb(fp), fill);
300 hton24(fh->fh_f_ctl, f_ctl | fill);
303 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
304 fr_eof(fp) = FC_EOF_N;
307 /* Initialize remaining fh fields from fc_fill_fc_hdr */
308 fh->fh_ox_id = htons(ep->oxid);
309 fh->fh_rx_id = htons(ep->rxid);
310 fh->fh_seq_id = ep->seq.id;
311 fh->fh_seq_cnt = htons(ep->seq.cnt);
315 * fc_exch_release() - Decrement an exchange's reference count
316 * @ep: Exchange to be released
318 * If the reference count reaches zero and the exchange is complete,
321 static void fc_exch_release(struct fc_exch *ep)
323 struct fc_exch_mgr *mp;
325 if (atomic_dec_and_test(&ep->ex_refcnt)) {
328 ep->destructor(&ep->seq, ep->arg);
329 WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));
330 mempool_free(ep, mp->ep_pool);
335 * fc_exch_timer_cancel() - cancel exch timer
336 * @ep: The exchange whose timer to be canceled
338 static inline void fc_exch_timer_cancel(struct fc_exch *ep)
340 if (cancel_delayed_work(&ep->timeout_work)) {
341 FC_EXCH_DBG(ep, "Exchange timer canceled\n");
342 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
347 * fc_exch_timer_set_locked() - Start a timer for an exchange w/ the
348 * the exchange lock held
349 * @ep: The exchange whose timer will start
350 * @timer_msec: The timeout period
352 * Used for upper level protocols to time out the exchange.
353 * The timer is cancelled when it fires or when the exchange completes.
355 static inline void fc_exch_timer_set_locked(struct fc_exch *ep,
356 unsigned int timer_msec)
358 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
361 FC_EXCH_DBG(ep, "Exchange timer armed : %d msecs\n", timer_msec);
363 fc_exch_hold(ep); /* hold for timer */
364 if (!queue_delayed_work(fc_exch_workqueue, &ep->timeout_work,
365 msecs_to_jiffies(timer_msec)))
370 * fc_exch_timer_set() - Lock the exchange and set the timer
371 * @ep: The exchange whose timer will start
372 * @timer_msec: The timeout period
374 static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec)
376 spin_lock_bh(&ep->ex_lock);
377 fc_exch_timer_set_locked(ep, timer_msec);
378 spin_unlock_bh(&ep->ex_lock);
382 * fc_exch_done_locked() - Complete an exchange with the exchange lock held
383 * @ep: The exchange that is complete
385 * Note: May sleep if invoked from outside a response handler.
387 static int fc_exch_done_locked(struct fc_exch *ep)
392 * We must check for completion in case there are two threads
393 * tyring to complete this. But the rrq code will reuse the
394 * ep, and in that case we only clear the resp and set it as
395 * complete, so it can be reused by the timer to send the rrq.
397 if (ep->state & FC_EX_DONE)
399 ep->esb_stat |= ESB_ST_COMPLETE;
401 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
402 ep->state |= FC_EX_DONE;
403 fc_exch_timer_cancel(ep);
410 * fc_exch_ptr_get() - Return an exchange from an exchange pool
411 * @pool: Exchange Pool to get an exchange from
412 * @index: Index of the exchange within the pool
414 * Use the index to get an exchange from within an exchange pool. exches
415 * will point to an array of exchange pointers. The index will select
416 * the exchange within the array.
418 static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,
421 struct fc_exch **exches = (struct fc_exch **)(pool + 1);
422 return exches[index];
426 * fc_exch_ptr_set() - Assign an exchange to a slot in an exchange pool
427 * @pool: The pool to assign the exchange to
428 * @index: The index in the pool where the exchange will be assigned
429 * @ep: The exchange to assign to the pool
431 static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
434 ((struct fc_exch **)(pool + 1))[index] = ep;
438 * fc_exch_delete() - Delete an exchange
439 * @ep: The exchange to be deleted
441 static void fc_exch_delete(struct fc_exch *ep)
443 struct fc_exch_pool *pool;
447 spin_lock_bh(&pool->lock);
448 WARN_ON(pool->total_exches <= 0);
449 pool->total_exches--;
451 /* update cache of free slot */
452 index = (ep->xid - ep->em->min_xid) >> fc_cpu_order;
453 if (pool->left == FC_XID_UNKNOWN)
455 else if (pool->right == FC_XID_UNKNOWN)
458 pool->next_index = index;
460 fc_exch_ptr_set(pool, index, NULL);
461 list_del(&ep->ex_list);
462 spin_unlock_bh(&pool->lock);
463 fc_exch_release(ep); /* drop hold for exch in mp */
466 static int fc_seq_send_locked(struct fc_lport *lport, struct fc_seq *sp,
470 struct fc_frame_header *fh = fc_frame_header_get(fp);
473 u8 fh_type = fh->fh_type;
475 ep = fc_seq_exch(sp);
477 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL)) {
482 WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT));
484 f_ctl = ntoh24(fh->fh_f_ctl);
485 fc_exch_setup_hdr(ep, fp, f_ctl);
486 fr_encaps(fp) = ep->encaps;
489 * update sequence count if this frame is carrying
490 * multiple FC frames when sequence offload is enabled
493 if (fr_max_payload(fp))
494 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),
502 error = lport->tt.frame_send(lport, fp);
504 if (fh_type == FC_TYPE_BLS)
508 * Update the exchange and sequence flags,
509 * assuming all frames for the sequence have been sent.
510 * We can only be called to send once for each sequence.
512 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
513 if (f_ctl & FC_FC_SEQ_INIT)
514 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
520 * fc_seq_send() - Send a frame using existing sequence/exchange pair
521 * @lport: The local port that the exchange will be sent on
522 * @sp: The sequence to be sent
523 * @fp: The frame to be sent on the exchange
525 * Note: The frame will be freed either by a direct call to fc_frame_free(fp)
526 * or indirectly by calling libfc_function_template.frame_send().
528 static int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp,
533 ep = fc_seq_exch(sp);
534 spin_lock_bh(&ep->ex_lock);
535 error = fc_seq_send_locked(lport, sp, fp);
536 spin_unlock_bh(&ep->ex_lock);
541 * fc_seq_alloc() - Allocate a sequence for a given exchange
542 * @ep: The exchange to allocate a new sequence for
543 * @seq_id: The sequence ID to be used
545 * We don't support multiple originated sequences on the same exchange.
546 * By implication, any previously originated sequence on this exchange
547 * is complete, and we reallocate the same sequence.
549 static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
561 * fc_seq_start_next_locked() - Allocate a new sequence on the same
562 * exchange as the supplied sequence
563 * @sp: The sequence/exchange to get a new sequence for
565 static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
567 struct fc_exch *ep = fc_seq_exch(sp);
569 sp = fc_seq_alloc(ep, ep->seq_id++);
570 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
576 * fc_seq_start_next() - Lock the exchange and get a new sequence
577 * for a given sequence/exchange pair
578 * @sp: The sequence/exchange to get a new exchange for
580 static struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
582 struct fc_exch *ep = fc_seq_exch(sp);
584 spin_lock_bh(&ep->ex_lock);
585 sp = fc_seq_start_next_locked(sp);
586 spin_unlock_bh(&ep->ex_lock);
592 * Set the response handler for the exchange associated with a sequence.
594 * Note: May sleep if invoked from outside a response handler.
596 static void fc_seq_set_resp(struct fc_seq *sp,
597 void (*resp)(struct fc_seq *, struct fc_frame *,
601 struct fc_exch *ep = fc_seq_exch(sp);
604 spin_lock_bh(&ep->ex_lock);
605 while (ep->resp_active && ep->resp_task != current) {
606 prepare_to_wait(&ep->resp_wq, &wait, TASK_UNINTERRUPTIBLE);
607 spin_unlock_bh(&ep->ex_lock);
611 spin_lock_bh(&ep->ex_lock);
613 finish_wait(&ep->resp_wq, &wait);
616 spin_unlock_bh(&ep->ex_lock);
620 * fc_exch_abort_locked() - Abort an exchange
621 * @ep: The exchange to be aborted
622 * @timer_msec: The period of time to wait before aborting
624 * Locking notes: Called with exch lock held
626 * Return value: 0 on success else error code
628 static int fc_exch_abort_locked(struct fc_exch *ep,
629 unsigned int timer_msec)
635 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
636 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP))
640 * Send the abort on a new sequence if possible.
642 sp = fc_seq_start_next_locked(&ep->seq);
647 fc_exch_timer_set_locked(ep, timer_msec);
651 * Send an abort for the sequence that timed out.
653 fp = fc_frame_alloc(ep->lp, 0);
655 ep->esb_stat |= ESB_ST_SEQ_INIT;
656 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
657 FC_TYPE_BLS, FC_FC_END_SEQ |
659 error = fc_seq_send_locked(ep->lp, sp, fp);
665 * If not logged into the fabric, don't send ABTS but leave
666 * sequence active until next timeout.
670 ep->esb_stat |= ESB_ST_ABNORMAL;
675 * fc_seq_exch_abort() - Abort an exchange and sequence
676 * @req_sp: The sequence to be aborted
677 * @timer_msec: The period of time to wait before aborting
679 * Generally called because of a timeout or an abort from the upper layer.
681 * Return value: 0 on success else error code
683 static int fc_seq_exch_abort(const struct fc_seq *req_sp,
684 unsigned int timer_msec)
689 ep = fc_seq_exch(req_sp);
690 spin_lock_bh(&ep->ex_lock);
691 error = fc_exch_abort_locked(ep, timer_msec);
692 spin_unlock_bh(&ep->ex_lock);
697 * fc_invoke_resp() - invoke ep->resp()
700 * It is assumed that after initialization finished (this means the
701 * first unlock of ex_lock after fc_exch_alloc()) ep->resp and ep->arg are
702 * modified only via fc_seq_set_resp(). This guarantees that none of these
703 * two variables changes if ep->resp_active > 0.
705 * If an fc_seq_set_resp() call is busy modifying ep->resp and ep->arg when
706 * this function is invoked, the first spin_lock_bh() call in this function
707 * will wait until fc_seq_set_resp() has finished modifying these variables.
709 * Since fc_exch_done() invokes fc_seq_set_resp() it is guaranteed that that
710 * ep->resp() won't be invoked after fc_exch_done() has returned.
712 * The response handler itself may invoke fc_exch_done(), which will clear the
716 * Returns true if and only if ep->resp has been invoked.
718 static bool fc_invoke_resp(struct fc_exch *ep, struct fc_seq *sp,
721 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
725 spin_lock_bh(&ep->ex_lock);
727 if (ep->resp_task != current)
728 ep->resp_task = !ep->resp_task ? current : NULL;
731 spin_unlock_bh(&ep->ex_lock);
738 spin_lock_bh(&ep->ex_lock);
739 if (--ep->resp_active == 0)
740 ep->resp_task = NULL;
741 spin_unlock_bh(&ep->ex_lock);
743 if (ep->resp_active == 0)
744 wake_up(&ep->resp_wq);
750 * fc_exch_timeout() - Handle exchange timer expiration
751 * @work: The work_struct identifying the exchange that timed out
753 static void fc_exch_timeout(struct work_struct *work)
755 struct fc_exch *ep = container_of(work, struct fc_exch,
757 struct fc_seq *sp = &ep->seq;
761 FC_EXCH_DBG(ep, "Exchange timed out\n");
763 spin_lock_bh(&ep->ex_lock);
764 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
767 e_stat = ep->esb_stat;
768 if (e_stat & ESB_ST_COMPLETE) {
769 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
770 spin_unlock_bh(&ep->ex_lock);
771 if (e_stat & ESB_ST_REC_QUAL)
775 if (e_stat & ESB_ST_ABNORMAL)
776 rc = fc_exch_done_locked(ep);
777 spin_unlock_bh(&ep->ex_lock);
780 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_TIMEOUT));
781 fc_seq_set_resp(sp, NULL, ep->arg);
782 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
786 spin_unlock_bh(&ep->ex_lock);
789 * This release matches the hold taken when the timer was set.
795 * fc_exch_em_alloc() - Allocate an exchange from a specified EM.
796 * @lport: The local port that the exchange is for
797 * @mp: The exchange manager that will allocate the exchange
799 * Returns pointer to allocated fc_exch with exch lock held.
801 static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
802 struct fc_exch_mgr *mp)
807 struct fc_exch_pool *pool;
809 /* allocate memory for exchange */
810 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);
812 atomic_inc(&mp->stats.no_free_exch);
815 memset(ep, 0, sizeof(*ep));
818 pool = per_cpu_ptr(mp->pool, cpu);
819 spin_lock_bh(&pool->lock);
822 /* peek cache of free slot */
823 if (pool->left != FC_XID_UNKNOWN) {
825 pool->left = FC_XID_UNKNOWN;
828 if (pool->right != FC_XID_UNKNOWN) {
830 pool->right = FC_XID_UNKNOWN;
834 index = pool->next_index;
835 /* allocate new exch from pool */
836 while (fc_exch_ptr_get(pool, index)) {
837 index = index == mp->pool_max_index ? 0 : index + 1;
838 if (index == pool->next_index)
841 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
843 fc_exch_hold(ep); /* hold for exch in mp */
844 spin_lock_init(&ep->ex_lock);
846 * Hold exch lock for caller to prevent fc_exch_reset()
847 * from releasing exch while fc_exch_alloc() caller is
848 * still working on exch.
850 spin_lock_bh(&ep->ex_lock);
852 fc_exch_ptr_set(pool, index, ep);
853 list_add_tail(&ep->ex_list, &pool->ex_list);
854 fc_seq_alloc(ep, ep->seq_id++);
855 pool->total_exches++;
856 spin_unlock_bh(&pool->lock);
861 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
865 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
866 ep->rxid = FC_XID_UNKNOWN;
867 ep->class = mp->class;
869 init_waitqueue_head(&ep->resp_wq);
870 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
874 spin_unlock_bh(&pool->lock);
875 atomic_inc(&mp->stats.no_free_exch_xid);
876 mempool_free(ep, mp->ep_pool);
881 * fc_exch_alloc() - Allocate an exchange from an EM on a
882 * local port's list of EMs.
883 * @lport: The local port that will own the exchange
884 * @fp: The FC frame that the exchange will be for
886 * This function walks the list of exchange manager(EM)
887 * anchors to select an EM for a new exchange allocation. The
888 * EM is selected when a NULL match function pointer is encountered
889 * or when a call to a match function returns true.
891 static inline struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
894 struct fc_exch_mgr_anchor *ema;
896 list_for_each_entry(ema, &lport->ema_list, ema_list)
897 if (!ema->match || ema->match(fp))
898 return fc_exch_em_alloc(lport, ema->mp);
903 * fc_exch_find() - Lookup and hold an exchange
904 * @mp: The exchange manager to lookup the exchange from
905 * @xid: The XID of the exchange to look up
907 static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
909 struct fc_exch_pool *pool;
910 struct fc_exch *ep = NULL;
911 u16 cpu = xid & fc_cpu_mask;
913 if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
914 printk_ratelimited(KERN_ERR
915 "libfc: lookup request for XID = %d, "
916 "indicates invalid CPU %d\n", xid, cpu);
920 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
921 pool = per_cpu_ptr(mp->pool, cpu);
922 spin_lock_bh(&pool->lock);
923 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
925 WARN_ON(ep->xid != xid);
928 spin_unlock_bh(&pool->lock);
935 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and
936 * the memory allocated for the related objects may be freed.
937 * @sp: The sequence that has completed
939 * Note: May sleep if invoked from outside a response handler.
941 static void fc_exch_done(struct fc_seq *sp)
943 struct fc_exch *ep = fc_seq_exch(sp);
946 spin_lock_bh(&ep->ex_lock);
947 rc = fc_exch_done_locked(ep);
948 spin_unlock_bh(&ep->ex_lock);
950 fc_seq_set_resp(sp, NULL, ep->arg);
956 * fc_exch_resp() - Allocate a new exchange for a response frame
957 * @lport: The local port that the exchange was for
958 * @mp: The exchange manager to allocate the exchange from
959 * @fp: The response frame
961 * Sets the responder ID in the frame header.
963 static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
964 struct fc_exch_mgr *mp,
968 struct fc_frame_header *fh;
970 ep = fc_exch_alloc(lport, fp);
972 ep->class = fc_frame_class(fp);
975 * Set EX_CTX indicating we're responding on this exchange.
977 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
978 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
979 fh = fc_frame_header_get(fp);
980 ep->sid = ntoh24(fh->fh_d_id);
981 ep->did = ntoh24(fh->fh_s_id);
985 * Allocated exchange has placed the XID in the
986 * originator field. Move it to the responder field,
987 * and set the originator XID from the frame.
990 ep->oxid = ntohs(fh->fh_ox_id);
991 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
992 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
993 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
995 fc_exch_hold(ep); /* hold for caller */
996 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
1002 * fc_seq_lookup_recip() - Find a sequence where the other end
1003 * originated the sequence
1004 * @lport: The local port that the frame was sent to
1005 * @mp: The Exchange Manager to lookup the exchange from
1006 * @fp: The frame associated with the sequence we're looking for
1008 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
1009 * on the ep that should be released by the caller.
1011 static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
1012 struct fc_exch_mgr *mp,
1013 struct fc_frame *fp)
1015 struct fc_frame_header *fh = fc_frame_header_get(fp);
1016 struct fc_exch *ep = NULL;
1017 struct fc_seq *sp = NULL;
1018 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
1022 f_ctl = ntoh24(fh->fh_f_ctl);
1023 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
1026 * Lookup or create the exchange if we will be creating the sequence.
1028 if (f_ctl & FC_FC_EX_CTX) {
1029 xid = ntohs(fh->fh_ox_id); /* we originated exch */
1030 ep = fc_exch_find(mp, xid);
1032 atomic_inc(&mp->stats.xid_not_found);
1033 reject = FC_RJT_OX_ID;
1036 if (ep->rxid == FC_XID_UNKNOWN)
1037 ep->rxid = ntohs(fh->fh_rx_id);
1038 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
1039 reject = FC_RJT_OX_ID;
1043 xid = ntohs(fh->fh_rx_id); /* we are the responder */
1046 * Special case for MDS issuing an ELS TEST with a
1048 * XXX take this out once we do the proper reject.
1050 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
1051 fc_frame_payload_op(fp) == ELS_TEST) {
1052 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
1053 xid = FC_XID_UNKNOWN;
1057 * new sequence - find the exchange
1059 ep = fc_exch_find(mp, xid);
1060 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
1062 atomic_inc(&mp->stats.xid_busy);
1063 reject = FC_RJT_RX_ID;
1066 ep = fc_exch_resp(lport, mp, fp);
1068 reject = FC_RJT_EXCH_EST; /* XXX */
1071 xid = ep->xid; /* get our XID */
1073 atomic_inc(&mp->stats.xid_not_found);
1074 reject = FC_RJT_RX_ID; /* XID not found */
1079 spin_lock_bh(&ep->ex_lock);
1081 * At this point, we have the exchange held.
1082 * Find or create the sequence.
1084 if (fc_sof_is_init(fr_sof(fp))) {
1086 sp->ssb_stat |= SSB_ST_RESP;
1087 sp->id = fh->fh_seq_id;
1090 if (sp->id != fh->fh_seq_id) {
1091 atomic_inc(&mp->stats.seq_not_found);
1092 if (f_ctl & FC_FC_END_SEQ) {
1094 * Update sequence_id based on incoming last
1095 * frame of sequence exchange. This is needed
1096 * for FC target where DDP has been used
1097 * on target where, stack is indicated only
1098 * about last frame's (payload _header) header.
1099 * Whereas "seq_id" which is part of
1100 * frame_header is allocated by initiator
1101 * which is totally different from "seq_id"
1102 * allocated when XFER_RDY was sent by target.
1103 * To avoid false -ve which results into not
1104 * sending RSP, hence write request on other
1105 * end never finishes.
1107 sp->ssb_stat |= SSB_ST_RESP;
1108 sp->id = fh->fh_seq_id;
1110 spin_unlock_bh(&ep->ex_lock);
1112 /* sequence/exch should exist */
1113 reject = FC_RJT_SEQ_ID;
1118 WARN_ON(ep != fc_seq_exch(sp));
1120 if (f_ctl & FC_FC_SEQ_INIT)
1121 ep->esb_stat |= ESB_ST_SEQ_INIT;
1122 spin_unlock_bh(&ep->ex_lock);
1128 fc_exch_done(&ep->seq);
1129 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
1134 * fc_seq_lookup_orig() - Find a sequence where this end
1135 * originated the sequence
1136 * @mp: The Exchange Manager to lookup the exchange from
1137 * @fp: The frame associated with the sequence we're looking for
1139 * Does not hold the sequence for the caller.
1141 static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
1142 struct fc_frame *fp)
1144 struct fc_frame_header *fh = fc_frame_header_get(fp);
1146 struct fc_seq *sp = NULL;
1150 f_ctl = ntoh24(fh->fh_f_ctl);
1151 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
1152 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
1153 ep = fc_exch_find(mp, xid);
1156 if (ep->seq.id == fh->fh_seq_id) {
1158 * Save the RX_ID if we didn't previously know it.
1161 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
1162 ep->rxid == FC_XID_UNKNOWN) {
1163 ep->rxid = ntohs(fh->fh_rx_id);
1166 fc_exch_release(ep);
1171 * fc_exch_set_addr() - Set the source and destination IDs for an exchange
1172 * @ep: The exchange to set the addresses for
1173 * @orig_id: The originator's ID
1174 * @resp_id: The responder's ID
1176 * Note this must be done before the first sequence of the exchange is sent.
1178 static void fc_exch_set_addr(struct fc_exch *ep,
1179 u32 orig_id, u32 resp_id)
1182 if (ep->esb_stat & ESB_ST_RESP) {
1192 * fc_seq_els_rsp_send() - Send an ELS response using information from
1193 * the existing sequence/exchange.
1194 * @fp: The received frame
1195 * @els_cmd: The ELS command to be sent
1196 * @els_data: The ELS data to be sent
1198 * The received frame is not freed.
1200 static void fc_seq_els_rsp_send(struct fc_frame *fp, enum fc_els_cmd els_cmd,
1201 struct fc_seq_els_data *els_data)
1205 fc_seq_ls_rjt(fp, els_data->reason, els_data->explan);
1211 fc_exch_els_rrq(fp);
1214 fc_exch_els_rec(fp);
1217 FC_LPORT_DBG(fr_dev(fp), "Invalid ELS CMD:%x\n", els_cmd);
1222 * fc_seq_send_last() - Send a sequence that is the last in the exchange
1223 * @sp: The sequence that is to be sent
1224 * @fp: The frame that will be sent on the sequence
1225 * @rctl: The R_CTL information to be sent
1226 * @fh_type: The frame header type
1228 static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
1229 enum fc_rctl rctl, enum fc_fh_type fh_type)
1232 struct fc_exch *ep = fc_seq_exch(sp);
1234 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
1236 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
1237 fc_seq_send_locked(ep->lp, sp, fp);
1241 * fc_seq_send_ack() - Send an acknowledgement that we've received a frame
1242 * @sp: The sequence to send the ACK on
1243 * @rx_fp: The received frame that is being acknoledged
1245 * Send ACK_1 (or equiv.) indicating we received something.
1247 static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
1249 struct fc_frame *fp;
1250 struct fc_frame_header *rx_fh;
1251 struct fc_frame_header *fh;
1252 struct fc_exch *ep = fc_seq_exch(sp);
1253 struct fc_lport *lport = ep->lp;
1257 * Don't send ACKs for class 3.
1259 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
1260 fp = fc_frame_alloc(lport, 0);
1264 fh = fc_frame_header_get(fp);
1265 fh->fh_r_ctl = FC_RCTL_ACK_1;
1266 fh->fh_type = FC_TYPE_BLS;
1269 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1270 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1271 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1272 * Last ACK uses bits 7-6 (continue sequence),
1273 * bits 5-4 are meaningful (what kind of ACK to use).
1275 rx_fh = fc_frame_header_get(rx_fp);
1276 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1277 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1278 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
1279 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
1280 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1281 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1282 hton24(fh->fh_f_ctl, f_ctl);
1284 fc_exch_setup_hdr(ep, fp, f_ctl);
1285 fh->fh_seq_id = rx_fh->fh_seq_id;
1286 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1287 fh->fh_parm_offset = htonl(1); /* ack single frame */
1289 fr_sof(fp) = fr_sof(rx_fp);
1290 if (f_ctl & FC_FC_END_SEQ)
1291 fr_eof(fp) = FC_EOF_T;
1293 fr_eof(fp) = FC_EOF_N;
1295 lport->tt.frame_send(lport, fp);
1300 * fc_exch_send_ba_rjt() - Send BLS Reject
1301 * @rx_fp: The frame being rejected
1302 * @reason: The reason the frame is being rejected
1303 * @explan: The explanation for the rejection
1305 * This is for rejecting BA_ABTS only.
1307 static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
1308 enum fc_ba_rjt_reason reason,
1309 enum fc_ba_rjt_explan explan)
1311 struct fc_frame *fp;
1312 struct fc_frame_header *rx_fh;
1313 struct fc_frame_header *fh;
1314 struct fc_ba_rjt *rp;
1315 struct fc_lport *lport;
1318 lport = fr_dev(rx_fp);
1319 fp = fc_frame_alloc(lport, sizeof(*rp));
1322 fh = fc_frame_header_get(fp);
1323 rx_fh = fc_frame_header_get(rx_fp);
1325 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1327 rp = fc_frame_payload_get(fp, sizeof(*rp));
1328 rp->br_reason = reason;
1329 rp->br_explan = explan;
1332 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1334 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1335 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1336 fh->fh_ox_id = rx_fh->fh_ox_id;
1337 fh->fh_rx_id = rx_fh->fh_rx_id;
1338 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1339 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1340 fh->fh_type = FC_TYPE_BLS;
1343 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1344 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1345 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1346 * Last ACK uses bits 7-6 (continue sequence),
1347 * bits 5-4 are meaningful (what kind of ACK to use).
1348 * Always set LAST_SEQ, END_SEQ.
1350 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1351 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1352 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1353 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1354 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1355 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1356 f_ctl &= ~FC_FC_FIRST_SEQ;
1357 hton24(fh->fh_f_ctl, f_ctl);
1359 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1360 fr_eof(fp) = FC_EOF_T;
1361 if (fc_sof_needs_ack(fr_sof(fp)))
1362 fr_eof(fp) = FC_EOF_N;
1364 lport->tt.frame_send(lport, fp);
1368 * fc_exch_recv_abts() - Handle an incoming ABTS
1369 * @ep: The exchange the abort was on
1370 * @rx_fp: The ABTS frame
1372 * This would be for target mode usually, but could be due to lost
1373 * FCP transfer ready, confirm or RRQ. We always handle this as an
1374 * exchange abort, ignoring the parameter.
1376 static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1378 struct fc_frame *fp;
1379 struct fc_ba_acc *ap;
1380 struct fc_frame_header *fh;
1386 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1390 spin_lock_bh(&ep->ex_lock);
1391 if (ep->esb_stat & ESB_ST_COMPLETE) {
1392 spin_unlock_bh(&ep->ex_lock);
1397 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
1398 ep->esb_stat |= ESB_ST_REC_QUAL;
1399 fc_exch_hold(ep); /* hold for REC_QUAL */
1401 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1402 fh = fc_frame_header_get(fp);
1403 ap = fc_frame_payload_get(fp, sizeof(*ap));
1404 memset(ap, 0, sizeof(*ap));
1406 ap->ba_high_seq_cnt = htons(0xffff);
1407 if (sp->ssb_stat & SSB_ST_RESP) {
1408 ap->ba_seq_id = sp->id;
1409 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1410 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1411 ap->ba_low_seq_cnt = htons(sp->cnt);
1413 sp = fc_seq_start_next_locked(sp);
1414 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1415 ep->esb_stat |= ESB_ST_ABNORMAL;
1416 spin_unlock_bh(&ep->ex_lock);
1419 fc_frame_free(rx_fp);
1423 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1428 * fc_seq_assign() - Assign exchange and sequence for incoming request
1429 * @lport: The local port that received the request
1430 * @fp: The request frame
1432 * On success, the sequence pointer will be returned and also in fr_seq(@fp).
1433 * A reference will be held on the exchange/sequence for the caller, which
1434 * must call fc_seq_release().
1436 static struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)
1438 struct fc_exch_mgr_anchor *ema;
1440 WARN_ON(lport != fr_dev(fp));
1441 WARN_ON(fr_seq(fp));
1444 list_for_each_entry(ema, &lport->ema_list, ema_list)
1445 if ((!ema->match || ema->match(fp)) &&
1446 fc_seq_lookup_recip(lport, ema->mp, fp) == FC_RJT_NONE)
1452 * fc_seq_release() - Release the hold
1453 * @sp: The sequence.
1455 static void fc_seq_release(struct fc_seq *sp)
1457 fc_exch_release(fc_seq_exch(sp));
1461 * fc_exch_recv_req() - Handler for an incoming request
1462 * @lport: The local port that received the request
1463 * @mp: The EM that the exchange is on
1464 * @fp: The request frame
1466 * This is used when the other end is originating the exchange
1469 static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp,
1470 struct fc_frame *fp)
1472 struct fc_frame_header *fh = fc_frame_header_get(fp);
1473 struct fc_seq *sp = NULL;
1474 struct fc_exch *ep = NULL;
1475 enum fc_pf_rjt_reason reject;
1477 /* We can have the wrong fc_lport at this point with NPIV, which is a
1478 * problem now that we know a new exchange needs to be allocated
1480 lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id));
1487 BUG_ON(fr_seq(fp)); /* XXX remove later */
1490 * If the RX_ID is 0xffff, don't allocate an exchange.
1491 * The upper-level protocol may request one later, if needed.
1493 if (fh->fh_rx_id == htons(FC_XID_UNKNOWN))
1494 return lport->tt.lport_recv(lport, fp);
1496 reject = fc_seq_lookup_recip(lport, mp, fp);
1497 if (reject == FC_RJT_NONE) {
1498 sp = fr_seq(fp); /* sequence will be held */
1499 ep = fc_seq_exch(sp);
1500 fc_seq_send_ack(sp, fp);
1501 ep->encaps = fr_encaps(fp);
1504 * Call the receive function.
1506 * The receive function may allocate a new sequence
1507 * over the old one, so we shouldn't change the
1508 * sequence after this.
1510 * The frame will be freed by the receive function.
1511 * If new exch resp handler is valid then call that
1514 if (!fc_invoke_resp(ep, sp, fp))
1515 lport->tt.lport_recv(lport, fp);
1516 fc_exch_release(ep); /* release from lookup */
1518 FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n",
1525 * fc_exch_recv_seq_resp() - Handler for an incoming response where the other
1526 * end is the originator of the sequence that is a
1527 * response to our initial exchange
1528 * @mp: The EM that the exchange is on
1529 * @fp: The response frame
1531 static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1533 struct fc_frame_header *fh = fc_frame_header_get(fp);
1540 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1542 atomic_inc(&mp->stats.xid_not_found);
1545 if (ep->esb_stat & ESB_ST_COMPLETE) {
1546 atomic_inc(&mp->stats.xid_not_found);
1549 if (ep->rxid == FC_XID_UNKNOWN)
1550 ep->rxid = ntohs(fh->fh_rx_id);
1551 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1552 atomic_inc(&mp->stats.xid_not_found);
1555 if (ep->did != ntoh24(fh->fh_s_id) &&
1556 ep->did != FC_FID_FLOGI) {
1557 atomic_inc(&mp->stats.xid_not_found);
1562 if (fc_sof_is_init(sof)) {
1563 sp->ssb_stat |= SSB_ST_RESP;
1564 sp->id = fh->fh_seq_id;
1565 } else if (sp->id != fh->fh_seq_id) {
1566 atomic_inc(&mp->stats.seq_not_found);
1570 f_ctl = ntoh24(fh->fh_f_ctl);
1573 spin_lock_bh(&ep->ex_lock);
1574 if (f_ctl & FC_FC_SEQ_INIT)
1575 ep->esb_stat |= ESB_ST_SEQ_INIT;
1576 spin_unlock_bh(&ep->ex_lock);
1578 if (fc_sof_needs_ack(sof))
1579 fc_seq_send_ack(sp, fp);
1581 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1582 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1583 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1584 spin_lock_bh(&ep->ex_lock);
1585 rc = fc_exch_done_locked(ep);
1586 WARN_ON(fc_seq_exch(sp) != ep);
1587 spin_unlock_bh(&ep->ex_lock);
1591 FC_EXCH_DBG(ep, "ep is completed already,"
1592 "hence skip calling the resp\n");
1598 * Call the receive function.
1599 * The sequence is held (has a refcnt) for us,
1600 * but not for the receive function.
1602 * The receive function may allocate a new sequence
1603 * over the old one, so we shouldn't change the
1604 * sequence after this.
1606 * The frame will be freed by the receive function.
1607 * If new exch resp handler is valid then call that
1610 if (!fc_invoke_resp(ep, sp, fp))
1614 fc_exch_release(ep);
1617 fc_exch_release(ep);
1623 * fc_exch_recv_resp() - Handler for a sequence where other end is
1624 * responding to our sequence
1625 * @mp: The EM that the exchange is on
1626 * @fp: The response frame
1628 static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1632 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1635 atomic_inc(&mp->stats.xid_not_found);
1637 atomic_inc(&mp->stats.non_bls_resp);
1643 * fc_exch_abts_resp() - Handler for a response to an ABT
1644 * @ep: The exchange that the frame is on
1645 * @fp: The response frame
1647 * This response would be to an ABTS cancelling an exchange or sequence.
1648 * The response can be either BA_ACC or BA_RJT
1650 static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1652 struct fc_frame_header *fh;
1653 struct fc_ba_acc *ap;
1657 int rc = 1, has_rec = 0;
1659 fh = fc_frame_header_get(fp);
1660 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1661 fc_exch_rctl_name(fh->fh_r_ctl));
1663 if (cancel_delayed_work_sync(&ep->timeout_work)) {
1664 FC_EXCH_DBG(ep, "Exchange timer canceled due to ABTS response\n");
1665 fc_exch_release(ep); /* release from pending timer hold */
1669 spin_lock_bh(&ep->ex_lock);
1670 switch (fh->fh_r_ctl) {
1671 case FC_RCTL_BA_ACC:
1672 ap = fc_frame_payload_get(fp, sizeof(*ap));
1677 * Decide whether to establish a Recovery Qualifier.
1678 * We do this if there is a non-empty SEQ_CNT range and
1679 * SEQ_ID is the same as the one we aborted.
1681 low = ntohs(ap->ba_low_seq_cnt);
1682 high = ntohs(ap->ba_high_seq_cnt);
1683 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1684 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1685 ap->ba_seq_id == ep->seq_id) && low != high) {
1686 ep->esb_stat |= ESB_ST_REC_QUAL;
1687 fc_exch_hold(ep); /* hold for recovery qualifier */
1691 case FC_RCTL_BA_RJT:
1697 /* do we need to do some other checks here. Can we reuse more of
1698 * fc_exch_recv_seq_resp
1702 * do we want to check END_SEQ as well as LAST_SEQ here?
1704 if (ep->fh_type != FC_TYPE_FCP &&
1705 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1706 rc = fc_exch_done_locked(ep);
1707 spin_unlock_bh(&ep->ex_lock);
1712 if (!fc_invoke_resp(ep, sp, fp))
1715 fc_exch_timer_set(ep, ep->r_a_tov);
1716 fc_exch_release(ep);
1720 * fc_exch_recv_bls() - Handler for a BLS sequence
1721 * @mp: The EM that the exchange is on
1722 * @fp: The request frame
1724 * The BLS frame is always a sequence initiated by the remote side.
1725 * We may be either the originator or recipient of the exchange.
1727 static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1729 struct fc_frame_header *fh;
1733 fh = fc_frame_header_get(fp);
1734 f_ctl = ntoh24(fh->fh_f_ctl);
1737 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1738 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1739 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1740 spin_lock_bh(&ep->ex_lock);
1741 ep->esb_stat |= ESB_ST_SEQ_INIT;
1742 spin_unlock_bh(&ep->ex_lock);
1744 if (f_ctl & FC_FC_SEQ_CTX) {
1746 * A response to a sequence we initiated.
1747 * This should only be ACKs for class 2 or F.
1749 switch (fh->fh_r_ctl) {
1755 FC_EXCH_DBG(ep, "BLS rctl %x - %s received\n",
1757 fc_exch_rctl_name(fh->fh_r_ctl));
1762 switch (fh->fh_r_ctl) {
1763 case FC_RCTL_BA_RJT:
1764 case FC_RCTL_BA_ACC:
1766 fc_exch_abts_resp(ep, fp);
1770 case FC_RCTL_BA_ABTS:
1771 fc_exch_recv_abts(ep, fp);
1773 default: /* ignore junk */
1779 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1783 * fc_seq_ls_acc() - Accept sequence with LS_ACC
1784 * @rx_fp: The received frame, not freed here.
1786 * If this fails due to allocation or transmit congestion, assume the
1787 * originator will repeat the sequence.
1789 static void fc_seq_ls_acc(struct fc_frame *rx_fp)
1791 struct fc_lport *lport;
1792 struct fc_els_ls_acc *acc;
1793 struct fc_frame *fp;
1795 lport = fr_dev(rx_fp);
1796 fp = fc_frame_alloc(lport, sizeof(*acc));
1799 acc = fc_frame_payload_get(fp, sizeof(*acc));
1800 memset(acc, 0, sizeof(*acc));
1801 acc->la_cmd = ELS_LS_ACC;
1802 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1803 lport->tt.frame_send(lport, fp);
1807 * fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT
1808 * @rx_fp: The received frame, not freed here.
1809 * @reason: The reason the sequence is being rejected
1810 * @explan: The explanation for the rejection
1812 * If this fails due to allocation or transmit congestion, assume the
1813 * originator will repeat the sequence.
1815 static void fc_seq_ls_rjt(struct fc_frame *rx_fp, enum fc_els_rjt_reason reason,
1816 enum fc_els_rjt_explan explan)
1818 struct fc_lport *lport;
1819 struct fc_els_ls_rjt *rjt;
1820 struct fc_frame *fp;
1822 lport = fr_dev(rx_fp);
1823 fp = fc_frame_alloc(lport, sizeof(*rjt));
1826 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1827 memset(rjt, 0, sizeof(*rjt));
1828 rjt->er_cmd = ELS_LS_RJT;
1829 rjt->er_reason = reason;
1830 rjt->er_explan = explan;
1831 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1832 lport->tt.frame_send(lport, fp);
1836 * fc_exch_reset() - Reset an exchange
1837 * @ep: The exchange to be reset
1839 * Note: May sleep if invoked from outside a response handler.
1841 static void fc_exch_reset(struct fc_exch *ep)
1846 spin_lock_bh(&ep->ex_lock);
1847 ep->state |= FC_EX_RST_CLEANUP;
1848 fc_exch_timer_cancel(ep);
1849 if (ep->esb_stat & ESB_ST_REC_QUAL)
1850 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1851 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1853 rc = fc_exch_done_locked(ep);
1854 spin_unlock_bh(&ep->ex_lock);
1861 FC_EXCH_DBG(ep, "ep is completed already,"
1862 "hence skip calling the resp\n");
1866 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_CLOSED));
1868 fc_seq_set_resp(sp, NULL, ep->arg);
1869 fc_exch_release(ep);
1873 * fc_exch_pool_reset() - Reset a per cpu exchange pool
1874 * @lport: The local port that the exchange pool is on
1875 * @pool: The exchange pool to be reset
1876 * @sid: The source ID
1877 * @did: The destination ID
1879 * Resets a per cpu exches pool, releasing all of its sequences
1880 * and exchanges. If sid is non-zero then reset only exchanges
1881 * we sourced from the local port's FID. If did is non-zero then
1882 * only reset exchanges destined for the local port's FID.
1884 static void fc_exch_pool_reset(struct fc_lport *lport,
1885 struct fc_exch_pool *pool,
1889 struct fc_exch *next;
1891 spin_lock_bh(&pool->lock);
1893 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1894 if ((lport == ep->lp) &&
1895 (sid == 0 || sid == ep->sid) &&
1896 (did == 0 || did == ep->did)) {
1898 spin_unlock_bh(&pool->lock);
1902 fc_exch_release(ep);
1903 spin_lock_bh(&pool->lock);
1906 * must restart loop incase while lock
1907 * was down multiple eps were released.
1912 pool->next_index = 0;
1913 pool->left = FC_XID_UNKNOWN;
1914 pool->right = FC_XID_UNKNOWN;
1915 spin_unlock_bh(&pool->lock);
1919 * fc_exch_mgr_reset() - Reset all EMs of a local port
1920 * @lport: The local port whose EMs are to be reset
1921 * @sid: The source ID
1922 * @did: The destination ID
1924 * Reset all EMs associated with a given local port. Release all
1925 * sequences and exchanges. If sid is non-zero then reset only the
1926 * exchanges sent from the local port's FID. If did is non-zero then
1927 * reset only exchanges destined for the local port's FID.
1929 void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1931 struct fc_exch_mgr_anchor *ema;
1934 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1935 for_each_possible_cpu(cpu)
1936 fc_exch_pool_reset(lport,
1937 per_cpu_ptr(ema->mp->pool, cpu),
1941 EXPORT_SYMBOL(fc_exch_mgr_reset);
1944 * fc_exch_lookup() - find an exchange
1945 * @lport: The local port
1946 * @xid: The exchange ID
1948 * Returns exchange pointer with hold for caller, or NULL if not found.
1950 static struct fc_exch *fc_exch_lookup(struct fc_lport *lport, u32 xid)
1952 struct fc_exch_mgr_anchor *ema;
1954 list_for_each_entry(ema, &lport->ema_list, ema_list)
1955 if (ema->mp->min_xid <= xid && xid <= ema->mp->max_xid)
1956 return fc_exch_find(ema->mp, xid);
1961 * fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests
1962 * @rfp: The REC frame, not freed here.
1964 * Note that the requesting port may be different than the S_ID in the request.
1966 static void fc_exch_els_rec(struct fc_frame *rfp)
1968 struct fc_lport *lport;
1969 struct fc_frame *fp;
1971 struct fc_els_rec *rp;
1972 struct fc_els_rec_acc *acc;
1973 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
1974 enum fc_els_rjt_explan explan;
1979 lport = fr_dev(rfp);
1980 rp = fc_frame_payload_get(rfp, sizeof(*rp));
1981 explan = ELS_EXPL_INV_LEN;
1984 sid = ntoh24(rp->rec_s_id);
1985 rxid = ntohs(rp->rec_rx_id);
1986 oxid = ntohs(rp->rec_ox_id);
1988 ep = fc_exch_lookup(lport,
1989 sid == fc_host_port_id(lport->host) ? oxid : rxid);
1990 explan = ELS_EXPL_OXID_RXID;
1993 if (ep->oid != sid || oxid != ep->oxid)
1995 if (rxid != FC_XID_UNKNOWN && rxid != ep->rxid)
1997 fp = fc_frame_alloc(lport, sizeof(*acc));
2001 acc = fc_frame_payload_get(fp, sizeof(*acc));
2002 memset(acc, 0, sizeof(*acc));
2003 acc->reca_cmd = ELS_LS_ACC;
2004 acc->reca_ox_id = rp->rec_ox_id;
2005 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
2006 acc->reca_rx_id = htons(ep->rxid);
2007 if (ep->sid == ep->oid)
2008 hton24(acc->reca_rfid, ep->did);
2010 hton24(acc->reca_rfid, ep->sid);
2011 acc->reca_fc4value = htonl(ep->seq.rec_data);
2012 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
2015 fc_fill_reply_hdr(fp, rfp, FC_RCTL_ELS_REP, 0);
2016 lport->tt.frame_send(lport, fp);
2018 fc_exch_release(ep);
2022 fc_exch_release(ep);
2024 fc_seq_ls_rjt(rfp, reason, explan);
2028 * fc_exch_rrq_resp() - Handler for RRQ responses
2029 * @sp: The sequence that the RRQ is on
2030 * @fp: The RRQ frame
2031 * @arg: The exchange that the RRQ is on
2033 * TODO: fix error handler.
2035 static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
2037 struct fc_exch *aborted_ep = arg;
2041 int err = PTR_ERR(fp);
2043 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
2045 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
2046 "frame error %d\n", err);
2050 op = fc_frame_payload_op(fp);
2055 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ\n");
2060 FC_EXCH_DBG(aborted_ep, "unexpected response op %x for RRQ\n",
2066 fc_exch_done(&aborted_ep->seq);
2067 /* drop hold for rec qual */
2068 fc_exch_release(aborted_ep);
2073 * fc_exch_seq_send() - Send a frame using a new exchange and sequence
2074 * @lport: The local port to send the frame on
2075 * @fp: The frame to be sent
2076 * @resp: The response handler for this request
2077 * @destructor: The destructor for the exchange
2078 * @arg: The argument to be passed to the response handler
2079 * @timer_msec: The timeout period for the exchange
2081 * The frame pointer with some of the header's fields must be
2082 * filled before calling this routine, those fields are:
2089 * - parameter or relative offset
2091 static struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
2092 struct fc_frame *fp,
2093 void (*resp)(struct fc_seq *,
2094 struct fc_frame *fp,
2096 void (*destructor)(struct fc_seq *,
2098 void *arg, u32 timer_msec)
2101 struct fc_seq *sp = NULL;
2102 struct fc_frame_header *fh;
2103 struct fc_fcp_pkt *fsp = NULL;
2106 ep = fc_exch_alloc(lport, fp);
2111 ep->esb_stat |= ESB_ST_SEQ_INIT;
2112 fh = fc_frame_header_get(fp);
2113 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
2115 ep->destructor = destructor;
2117 ep->r_a_tov = FC_DEF_R_A_TOV;
2121 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
2122 ep->f_ctl = ntoh24(fh->fh_f_ctl);
2123 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
2126 if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD) {
2128 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
2131 if (unlikely(lport->tt.frame_send(lport, fp)))
2135 fc_exch_timer_set_locked(ep, timer_msec);
2136 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
2138 if (ep->f_ctl & FC_FC_SEQ_INIT)
2139 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
2140 spin_unlock_bh(&ep->ex_lock);
2144 fc_fcp_ddp_done(fsp);
2145 rc = fc_exch_done_locked(ep);
2146 spin_unlock_bh(&ep->ex_lock);
2153 * fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command
2154 * @ep: The exchange to send the RRQ on
2156 * This tells the remote port to stop blocking the use of
2157 * the exchange and the seq_cnt range.
2159 static void fc_exch_rrq(struct fc_exch *ep)
2161 struct fc_lport *lport;
2162 struct fc_els_rrq *rrq;
2163 struct fc_frame *fp;
2168 fp = fc_frame_alloc(lport, sizeof(*rrq));
2172 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
2173 memset(rrq, 0, sizeof(*rrq));
2174 rrq->rrq_cmd = ELS_RRQ;
2175 hton24(rrq->rrq_s_id, ep->sid);
2176 rrq->rrq_ox_id = htons(ep->oxid);
2177 rrq->rrq_rx_id = htons(ep->rxid);
2180 if (ep->esb_stat & ESB_ST_RESP)
2183 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
2184 lport->port_id, FC_TYPE_ELS,
2185 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
2187 if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep,
2192 spin_lock_bh(&ep->ex_lock);
2193 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
2194 spin_unlock_bh(&ep->ex_lock);
2195 /* drop hold for rec qual */
2196 fc_exch_release(ep);
2199 ep->esb_stat |= ESB_ST_REC_QUAL;
2200 fc_exch_timer_set_locked(ep, ep->r_a_tov);
2201 spin_unlock_bh(&ep->ex_lock);
2205 * fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests
2206 * @fp: The RRQ frame, not freed here.
2208 static void fc_exch_els_rrq(struct fc_frame *fp)
2210 struct fc_lport *lport;
2211 struct fc_exch *ep = NULL; /* request or subject exchange */
2212 struct fc_els_rrq *rp;
2215 enum fc_els_rjt_explan explan;
2218 rp = fc_frame_payload_get(fp, sizeof(*rp));
2219 explan = ELS_EXPL_INV_LEN;
2224 * lookup subject exchange.
2226 sid = ntoh24(rp->rrq_s_id); /* subject source */
2227 xid = fc_host_port_id(lport->host) == sid ?
2228 ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
2229 ep = fc_exch_lookup(lport, xid);
2230 explan = ELS_EXPL_OXID_RXID;
2233 spin_lock_bh(&ep->ex_lock);
2234 if (ep->oxid != ntohs(rp->rrq_ox_id))
2236 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
2237 ep->rxid != FC_XID_UNKNOWN)
2239 explan = ELS_EXPL_SID;
2244 * Clear Recovery Qualifier state, and cancel timer if complete.
2246 if (ep->esb_stat & ESB_ST_REC_QUAL) {
2247 ep->esb_stat &= ~ESB_ST_REC_QUAL;
2248 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
2250 if (ep->esb_stat & ESB_ST_COMPLETE)
2251 fc_exch_timer_cancel(ep);
2253 spin_unlock_bh(&ep->ex_lock);
2262 spin_unlock_bh(&ep->ex_lock);
2264 fc_seq_ls_rjt(fp, ELS_RJT_LOGIC, explan);
2267 fc_exch_release(ep); /* drop hold from fc_exch_find */
2271 * fc_exch_update_stats() - update exches stats to lport
2272 * @lport: The local port to update exchange manager stats
2274 void fc_exch_update_stats(struct fc_lport *lport)
2276 struct fc_host_statistics *st;
2277 struct fc_exch_mgr_anchor *ema;
2278 struct fc_exch_mgr *mp;
2280 st = &lport->host_stats;
2282 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2284 st->fc_no_free_exch += atomic_read(&mp->stats.no_free_exch);
2285 st->fc_no_free_exch_xid +=
2286 atomic_read(&mp->stats.no_free_exch_xid);
2287 st->fc_xid_not_found += atomic_read(&mp->stats.xid_not_found);
2288 st->fc_xid_busy += atomic_read(&mp->stats.xid_busy);
2289 st->fc_seq_not_found += atomic_read(&mp->stats.seq_not_found);
2290 st->fc_non_bls_resp += atomic_read(&mp->stats.non_bls_resp);
2293 EXPORT_SYMBOL(fc_exch_update_stats);
2296 * fc_exch_mgr_add() - Add an exchange manager to a local port's list of EMs
2297 * @lport: The local port to add the exchange manager to
2298 * @mp: The exchange manager to be added to the local port
2299 * @match: The match routine that indicates when this EM should be used
2301 struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
2302 struct fc_exch_mgr *mp,
2303 bool (*match)(struct fc_frame *))
2305 struct fc_exch_mgr_anchor *ema;
2307 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
2313 /* add EM anchor to EM anchors list */
2314 list_add_tail(&ema->ema_list, &lport->ema_list);
2315 kref_get(&mp->kref);
2318 EXPORT_SYMBOL(fc_exch_mgr_add);
2321 * fc_exch_mgr_destroy() - Destroy an exchange manager
2322 * @kref: The reference to the EM to be destroyed
2324 static void fc_exch_mgr_destroy(struct kref *kref)
2326 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
2328 mempool_destroy(mp->ep_pool);
2329 free_percpu(mp->pool);
2334 * fc_exch_mgr_del() - Delete an EM from a local port's list
2335 * @ema: The exchange manager anchor identifying the EM to be deleted
2337 void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
2339 /* remove EM anchor from EM anchors list */
2340 list_del(&ema->ema_list);
2341 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
2344 EXPORT_SYMBOL(fc_exch_mgr_del);
2347 * fc_exch_mgr_list_clone() - Share all exchange manager objects
2348 * @src: Source lport to clone exchange managers from
2349 * @dst: New lport that takes references to all the exchange managers
2351 int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)
2353 struct fc_exch_mgr_anchor *ema, *tmp;
2355 list_for_each_entry(ema, &src->ema_list, ema_list) {
2356 if (!fc_exch_mgr_add(dst, ema->mp, ema->match))
2361 list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)
2362 fc_exch_mgr_del(ema);
2365 EXPORT_SYMBOL(fc_exch_mgr_list_clone);
2368 * fc_exch_mgr_alloc() - Allocate an exchange manager
2369 * @lport: The local port that the new EM will be associated with
2370 * @class: The default FC class for new exchanges
2371 * @min_xid: The minimum XID for exchanges from the new EM
2372 * @max_xid: The maximum XID for exchanges from the new EM
2373 * @match: The match routine for the new EM
2375 struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport,
2376 enum fc_class class,
2377 u16 min_xid, u16 max_xid,
2378 bool (*match)(struct fc_frame *))
2380 struct fc_exch_mgr *mp;
2381 u16 pool_exch_range;
2384 struct fc_exch_pool *pool;
2386 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
2387 (min_xid & fc_cpu_mask) != 0) {
2388 FC_LPORT_DBG(lport, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
2394 * allocate memory for EM
2396 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
2401 /* adjust em exch xid range for offload */
2402 mp->min_xid = min_xid;
2404 /* reduce range so per cpu pool fits into PCPU_MIN_UNIT_SIZE pool */
2405 pool_exch_range = (PCPU_MIN_UNIT_SIZE - sizeof(*pool)) /
2406 sizeof(struct fc_exch *);
2407 if ((max_xid - min_xid + 1) / (fc_cpu_mask + 1) > pool_exch_range) {
2408 mp->max_xid = pool_exch_range * (fc_cpu_mask + 1) +
2411 mp->max_xid = max_xid;
2412 pool_exch_range = (mp->max_xid - mp->min_xid + 1) /
2416 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
2421 * Setup per cpu exch pool with entire exchange id range equally
2422 * divided across all cpus. The exch pointers array memory is
2423 * allocated for exch range per pool.
2425 mp->pool_max_index = pool_exch_range - 1;
2428 * Allocate and initialize per cpu exch pool
2430 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
2431 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
2434 for_each_possible_cpu(cpu) {
2435 pool = per_cpu_ptr(mp->pool, cpu);
2436 pool->next_index = 0;
2437 pool->left = FC_XID_UNKNOWN;
2438 pool->right = FC_XID_UNKNOWN;
2439 spin_lock_init(&pool->lock);
2440 INIT_LIST_HEAD(&pool->ex_list);
2443 kref_init(&mp->kref);
2444 if (!fc_exch_mgr_add(lport, mp, match)) {
2445 free_percpu(mp->pool);
2450 * Above kref_init() sets mp->kref to 1 and then
2451 * call to fc_exch_mgr_add incremented mp->kref again,
2452 * so adjust that extra increment.
2454 kref_put(&mp->kref, fc_exch_mgr_destroy);
2458 mempool_destroy(mp->ep_pool);
2463 EXPORT_SYMBOL(fc_exch_mgr_alloc);
2466 * fc_exch_mgr_free() - Free all exchange managers on a local port
2467 * @lport: The local port whose EMs are to be freed
2469 void fc_exch_mgr_free(struct fc_lport *lport)
2471 struct fc_exch_mgr_anchor *ema, *next;
2473 flush_workqueue(fc_exch_workqueue);
2474 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
2475 fc_exch_mgr_del(ema);
2477 EXPORT_SYMBOL(fc_exch_mgr_free);
2480 * fc_find_ema() - Lookup and return appropriate Exchange Manager Anchor depending
2483 * @lport: The local port the frame was received on
2484 * @fh: The received frame header
2486 static struct fc_exch_mgr_anchor *fc_find_ema(u32 f_ctl,
2487 struct fc_lport *lport,
2488 struct fc_frame_header *fh)
2490 struct fc_exch_mgr_anchor *ema;
2493 if (f_ctl & FC_FC_EX_CTX)
2494 xid = ntohs(fh->fh_ox_id);
2496 xid = ntohs(fh->fh_rx_id);
2497 if (xid == FC_XID_UNKNOWN)
2498 return list_entry(lport->ema_list.prev,
2499 typeof(*ema), ema_list);
2502 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2503 if ((xid >= ema->mp->min_xid) &&
2504 (xid <= ema->mp->max_xid))
2510 * fc_exch_recv() - Handler for received frames
2511 * @lport: The local port the frame was received on
2512 * @fp: The received frame
2514 void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)
2516 struct fc_frame_header *fh = fc_frame_header_get(fp);
2517 struct fc_exch_mgr_anchor *ema;
2521 if (!lport || lport->state == LPORT_ST_DISABLED) {
2522 FC_LIBFC_DBG("Receiving frames for an lport that "
2523 "has not been initialized correctly\n");
2528 f_ctl = ntoh24(fh->fh_f_ctl);
2529 ema = fc_find_ema(f_ctl, lport, fh);
2531 FC_LPORT_DBG(lport, "Unable to find Exchange Manager Anchor,"
2532 "fc_ctl <0x%x>, xid <0x%x>\n",
2534 (f_ctl & FC_FC_EX_CTX) ?
2535 ntohs(fh->fh_ox_id) :
2536 ntohs(fh->fh_rx_id));
2542 * If frame is marked invalid, just drop it.
2544 switch (fr_eof(fp)) {
2546 if (f_ctl & FC_FC_END_SEQ)
2547 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2550 if (fh->fh_type == FC_TYPE_BLS)
2551 fc_exch_recv_bls(ema->mp, fp);
2552 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2554 fc_exch_recv_seq_resp(ema->mp, fp);
2555 else if (f_ctl & FC_FC_SEQ_CTX)
2556 fc_exch_recv_resp(ema->mp, fp);
2557 else /* no EX_CTX and no SEQ_CTX */
2558 fc_exch_recv_req(lport, ema->mp, fp);
2561 FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)",
2566 EXPORT_SYMBOL(fc_exch_recv);
2569 * fc_exch_init() - Initialize the exchange layer for a local port
2570 * @lport: The local port to initialize the exchange layer for
2572 int fc_exch_init(struct fc_lport *lport)
2574 if (!lport->tt.seq_start_next)
2575 lport->tt.seq_start_next = fc_seq_start_next;
2577 if (!lport->tt.seq_set_resp)
2578 lport->tt.seq_set_resp = fc_seq_set_resp;
2580 if (!lport->tt.exch_seq_send)
2581 lport->tt.exch_seq_send = fc_exch_seq_send;
2583 if (!lport->tt.seq_send)
2584 lport->tt.seq_send = fc_seq_send;
2586 if (!lport->tt.seq_els_rsp_send)
2587 lport->tt.seq_els_rsp_send = fc_seq_els_rsp_send;
2589 if (!lport->tt.exch_done)
2590 lport->tt.exch_done = fc_exch_done;
2592 if (!lport->tt.exch_mgr_reset)
2593 lport->tt.exch_mgr_reset = fc_exch_mgr_reset;
2595 if (!lport->tt.seq_exch_abort)
2596 lport->tt.seq_exch_abort = fc_seq_exch_abort;
2598 if (!lport->tt.seq_assign)
2599 lport->tt.seq_assign = fc_seq_assign;
2601 if (!lport->tt.seq_release)
2602 lport->tt.seq_release = fc_seq_release;
2606 EXPORT_SYMBOL(fc_exch_init);
2609 * fc_setup_exch_mgr() - Setup an exchange manager
2611 int fc_setup_exch_mgr(void)
2613 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2614 0, SLAB_HWCACHE_ALIGN, NULL);
2619 * Initialize fc_cpu_mask and fc_cpu_order. The
2620 * fc_cpu_mask is set for nr_cpu_ids rounded up
2621 * to order of 2's * power and order is stored
2622 * in fc_cpu_order as this is later required in
2623 * mapping between an exch id and exch array index
2624 * in per cpu exch pool.
2626 * This round up is required to align fc_cpu_mask
2627 * to exchange id's lower bits such that all incoming
2628 * frames of an exchange gets delivered to the same
2629 * cpu on which exchange originated by simple bitwise
2630 * AND operation between fc_cpu_mask and exchange id.
2632 fc_cpu_order = ilog2(roundup_pow_of_two(nr_cpu_ids));
2633 fc_cpu_mask = (1 << fc_cpu_order) - 1;
2635 fc_exch_workqueue = create_singlethread_workqueue("fc_exch_workqueue");
2636 if (!fc_exch_workqueue)
2640 kmem_cache_destroy(fc_em_cachep);
2645 * fc_destroy_exch_mgr() - Destroy an exchange manager
2647 void fc_destroy_exch_mgr(void)
2649 destroy_workqueue(fc_exch_workqueue);
2650 kmem_cache_destroy(fc_em_cachep);