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;
912 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
913 pool = per_cpu_ptr(mp->pool, xid & fc_cpu_mask);
914 spin_lock_bh(&pool->lock);
915 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
917 WARN_ON(ep->xid != xid);
920 spin_unlock_bh(&pool->lock);
927 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and
928 * the memory allocated for the related objects may be freed.
929 * @sp: The sequence that has completed
931 * Note: May sleep if invoked from outside a response handler.
933 static void fc_exch_done(struct fc_seq *sp)
935 struct fc_exch *ep = fc_seq_exch(sp);
938 spin_lock_bh(&ep->ex_lock);
939 rc = fc_exch_done_locked(ep);
940 spin_unlock_bh(&ep->ex_lock);
942 fc_seq_set_resp(sp, NULL, ep->arg);
948 * fc_exch_resp() - Allocate a new exchange for a response frame
949 * @lport: The local port that the exchange was for
950 * @mp: The exchange manager to allocate the exchange from
951 * @fp: The response frame
953 * Sets the responder ID in the frame header.
955 static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
956 struct fc_exch_mgr *mp,
960 struct fc_frame_header *fh;
962 ep = fc_exch_alloc(lport, fp);
964 ep->class = fc_frame_class(fp);
967 * Set EX_CTX indicating we're responding on this exchange.
969 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
970 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
971 fh = fc_frame_header_get(fp);
972 ep->sid = ntoh24(fh->fh_d_id);
973 ep->did = ntoh24(fh->fh_s_id);
977 * Allocated exchange has placed the XID in the
978 * originator field. Move it to the responder field,
979 * and set the originator XID from the frame.
982 ep->oxid = ntohs(fh->fh_ox_id);
983 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
984 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
985 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
987 fc_exch_hold(ep); /* hold for caller */
988 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
994 * fc_seq_lookup_recip() - Find a sequence where the other end
995 * originated the sequence
996 * @lport: The local port that the frame was sent to
997 * @mp: The Exchange Manager to lookup the exchange from
998 * @fp: The frame associated with the sequence we're looking for
1000 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
1001 * on the ep that should be released by the caller.
1003 static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
1004 struct fc_exch_mgr *mp,
1005 struct fc_frame *fp)
1007 struct fc_frame_header *fh = fc_frame_header_get(fp);
1008 struct fc_exch *ep = NULL;
1009 struct fc_seq *sp = NULL;
1010 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
1014 f_ctl = ntoh24(fh->fh_f_ctl);
1015 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
1018 * Lookup or create the exchange if we will be creating the sequence.
1020 if (f_ctl & FC_FC_EX_CTX) {
1021 xid = ntohs(fh->fh_ox_id); /* we originated exch */
1022 ep = fc_exch_find(mp, xid);
1024 atomic_inc(&mp->stats.xid_not_found);
1025 reject = FC_RJT_OX_ID;
1028 if (ep->rxid == FC_XID_UNKNOWN)
1029 ep->rxid = ntohs(fh->fh_rx_id);
1030 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
1031 reject = FC_RJT_OX_ID;
1035 xid = ntohs(fh->fh_rx_id); /* we are the responder */
1038 * Special case for MDS issuing an ELS TEST with a
1040 * XXX take this out once we do the proper reject.
1042 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
1043 fc_frame_payload_op(fp) == ELS_TEST) {
1044 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
1045 xid = FC_XID_UNKNOWN;
1049 * new sequence - find the exchange
1051 ep = fc_exch_find(mp, xid);
1052 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
1054 atomic_inc(&mp->stats.xid_busy);
1055 reject = FC_RJT_RX_ID;
1058 ep = fc_exch_resp(lport, mp, fp);
1060 reject = FC_RJT_EXCH_EST; /* XXX */
1063 xid = ep->xid; /* get our XID */
1065 atomic_inc(&mp->stats.xid_not_found);
1066 reject = FC_RJT_RX_ID; /* XID not found */
1071 spin_lock_bh(&ep->ex_lock);
1073 * At this point, we have the exchange held.
1074 * Find or create the sequence.
1076 if (fc_sof_is_init(fr_sof(fp))) {
1078 sp->ssb_stat |= SSB_ST_RESP;
1079 sp->id = fh->fh_seq_id;
1082 if (sp->id != fh->fh_seq_id) {
1083 atomic_inc(&mp->stats.seq_not_found);
1084 if (f_ctl & FC_FC_END_SEQ) {
1086 * Update sequence_id based on incoming last
1087 * frame of sequence exchange. This is needed
1088 * for FC target where DDP has been used
1089 * on target where, stack is indicated only
1090 * about last frame's (payload _header) header.
1091 * Whereas "seq_id" which is part of
1092 * frame_header is allocated by initiator
1093 * which is totally different from "seq_id"
1094 * allocated when XFER_RDY was sent by target.
1095 * To avoid false -ve which results into not
1096 * sending RSP, hence write request on other
1097 * end never finishes.
1099 sp->ssb_stat |= SSB_ST_RESP;
1100 sp->id = fh->fh_seq_id;
1102 spin_unlock_bh(&ep->ex_lock);
1104 /* sequence/exch should exist */
1105 reject = FC_RJT_SEQ_ID;
1110 WARN_ON(ep != fc_seq_exch(sp));
1112 if (f_ctl & FC_FC_SEQ_INIT)
1113 ep->esb_stat |= ESB_ST_SEQ_INIT;
1114 spin_unlock_bh(&ep->ex_lock);
1120 fc_exch_done(&ep->seq);
1121 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
1126 * fc_seq_lookup_orig() - Find a sequence where this end
1127 * originated the sequence
1128 * @mp: The Exchange Manager to lookup the exchange from
1129 * @fp: The frame associated with the sequence we're looking for
1131 * Does not hold the sequence for the caller.
1133 static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
1134 struct fc_frame *fp)
1136 struct fc_frame_header *fh = fc_frame_header_get(fp);
1138 struct fc_seq *sp = NULL;
1142 f_ctl = ntoh24(fh->fh_f_ctl);
1143 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
1144 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
1145 ep = fc_exch_find(mp, xid);
1148 if (ep->seq.id == fh->fh_seq_id) {
1150 * Save the RX_ID if we didn't previously know it.
1153 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
1154 ep->rxid == FC_XID_UNKNOWN) {
1155 ep->rxid = ntohs(fh->fh_rx_id);
1158 fc_exch_release(ep);
1163 * fc_exch_set_addr() - Set the source and destination IDs for an exchange
1164 * @ep: The exchange to set the addresses for
1165 * @orig_id: The originator's ID
1166 * @resp_id: The responder's ID
1168 * Note this must be done before the first sequence of the exchange is sent.
1170 static void fc_exch_set_addr(struct fc_exch *ep,
1171 u32 orig_id, u32 resp_id)
1174 if (ep->esb_stat & ESB_ST_RESP) {
1184 * fc_seq_els_rsp_send() - Send an ELS response using information from
1185 * the existing sequence/exchange.
1186 * @fp: The received frame
1187 * @els_cmd: The ELS command to be sent
1188 * @els_data: The ELS data to be sent
1190 * The received frame is not freed.
1192 static void fc_seq_els_rsp_send(struct fc_frame *fp, enum fc_els_cmd els_cmd,
1193 struct fc_seq_els_data *els_data)
1197 fc_seq_ls_rjt(fp, els_data->reason, els_data->explan);
1203 fc_exch_els_rrq(fp);
1206 fc_exch_els_rec(fp);
1209 FC_LPORT_DBG(fr_dev(fp), "Invalid ELS CMD:%x\n", els_cmd);
1214 * fc_seq_send_last() - Send a sequence that is the last in the exchange
1215 * @sp: The sequence that is to be sent
1216 * @fp: The frame that will be sent on the sequence
1217 * @rctl: The R_CTL information to be sent
1218 * @fh_type: The frame header type
1220 static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
1221 enum fc_rctl rctl, enum fc_fh_type fh_type)
1224 struct fc_exch *ep = fc_seq_exch(sp);
1226 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
1228 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
1229 fc_seq_send_locked(ep->lp, sp, fp);
1233 * fc_seq_send_ack() - Send an acknowledgement that we've received a frame
1234 * @sp: The sequence to send the ACK on
1235 * @rx_fp: The received frame that is being acknoledged
1237 * Send ACK_1 (or equiv.) indicating we received something.
1239 static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
1241 struct fc_frame *fp;
1242 struct fc_frame_header *rx_fh;
1243 struct fc_frame_header *fh;
1244 struct fc_exch *ep = fc_seq_exch(sp);
1245 struct fc_lport *lport = ep->lp;
1249 * Don't send ACKs for class 3.
1251 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
1252 fp = fc_frame_alloc(lport, 0);
1256 fh = fc_frame_header_get(fp);
1257 fh->fh_r_ctl = FC_RCTL_ACK_1;
1258 fh->fh_type = FC_TYPE_BLS;
1261 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1262 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1263 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1264 * Last ACK uses bits 7-6 (continue sequence),
1265 * bits 5-4 are meaningful (what kind of ACK to use).
1267 rx_fh = fc_frame_header_get(rx_fp);
1268 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1269 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1270 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
1271 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
1272 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1273 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1274 hton24(fh->fh_f_ctl, f_ctl);
1276 fc_exch_setup_hdr(ep, fp, f_ctl);
1277 fh->fh_seq_id = rx_fh->fh_seq_id;
1278 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1279 fh->fh_parm_offset = htonl(1); /* ack single frame */
1281 fr_sof(fp) = fr_sof(rx_fp);
1282 if (f_ctl & FC_FC_END_SEQ)
1283 fr_eof(fp) = FC_EOF_T;
1285 fr_eof(fp) = FC_EOF_N;
1287 lport->tt.frame_send(lport, fp);
1292 * fc_exch_send_ba_rjt() - Send BLS Reject
1293 * @rx_fp: The frame being rejected
1294 * @reason: The reason the frame is being rejected
1295 * @explan: The explanation for the rejection
1297 * This is for rejecting BA_ABTS only.
1299 static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
1300 enum fc_ba_rjt_reason reason,
1301 enum fc_ba_rjt_explan explan)
1303 struct fc_frame *fp;
1304 struct fc_frame_header *rx_fh;
1305 struct fc_frame_header *fh;
1306 struct fc_ba_rjt *rp;
1307 struct fc_lport *lport;
1310 lport = fr_dev(rx_fp);
1311 fp = fc_frame_alloc(lport, sizeof(*rp));
1314 fh = fc_frame_header_get(fp);
1315 rx_fh = fc_frame_header_get(rx_fp);
1317 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1319 rp = fc_frame_payload_get(fp, sizeof(*rp));
1320 rp->br_reason = reason;
1321 rp->br_explan = explan;
1324 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1326 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1327 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1328 fh->fh_ox_id = rx_fh->fh_ox_id;
1329 fh->fh_rx_id = rx_fh->fh_rx_id;
1330 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1331 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1332 fh->fh_type = FC_TYPE_BLS;
1335 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1336 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1337 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1338 * Last ACK uses bits 7-6 (continue sequence),
1339 * bits 5-4 are meaningful (what kind of ACK to use).
1340 * Always set LAST_SEQ, END_SEQ.
1342 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1343 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1344 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1345 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1346 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1347 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1348 f_ctl &= ~FC_FC_FIRST_SEQ;
1349 hton24(fh->fh_f_ctl, f_ctl);
1351 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1352 fr_eof(fp) = FC_EOF_T;
1353 if (fc_sof_needs_ack(fr_sof(fp)))
1354 fr_eof(fp) = FC_EOF_N;
1356 lport->tt.frame_send(lport, fp);
1360 * fc_exch_recv_abts() - Handle an incoming ABTS
1361 * @ep: The exchange the abort was on
1362 * @rx_fp: The ABTS frame
1364 * This would be for target mode usually, but could be due to lost
1365 * FCP transfer ready, confirm or RRQ. We always handle this as an
1366 * exchange abort, ignoring the parameter.
1368 static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1370 struct fc_frame *fp;
1371 struct fc_ba_acc *ap;
1372 struct fc_frame_header *fh;
1378 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1382 spin_lock_bh(&ep->ex_lock);
1383 if (ep->esb_stat & ESB_ST_COMPLETE) {
1384 spin_unlock_bh(&ep->ex_lock);
1389 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
1390 ep->esb_stat |= ESB_ST_REC_QUAL;
1391 fc_exch_hold(ep); /* hold for REC_QUAL */
1393 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1394 fh = fc_frame_header_get(fp);
1395 ap = fc_frame_payload_get(fp, sizeof(*ap));
1396 memset(ap, 0, sizeof(*ap));
1398 ap->ba_high_seq_cnt = htons(0xffff);
1399 if (sp->ssb_stat & SSB_ST_RESP) {
1400 ap->ba_seq_id = sp->id;
1401 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1402 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1403 ap->ba_low_seq_cnt = htons(sp->cnt);
1405 sp = fc_seq_start_next_locked(sp);
1406 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1407 ep->esb_stat |= ESB_ST_ABNORMAL;
1408 spin_unlock_bh(&ep->ex_lock);
1411 fc_frame_free(rx_fp);
1415 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1420 * fc_seq_assign() - Assign exchange and sequence for incoming request
1421 * @lport: The local port that received the request
1422 * @fp: The request frame
1424 * On success, the sequence pointer will be returned and also in fr_seq(@fp).
1425 * A reference will be held on the exchange/sequence for the caller, which
1426 * must call fc_seq_release().
1428 static struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)
1430 struct fc_exch_mgr_anchor *ema;
1432 WARN_ON(lport != fr_dev(fp));
1433 WARN_ON(fr_seq(fp));
1436 list_for_each_entry(ema, &lport->ema_list, ema_list)
1437 if ((!ema->match || ema->match(fp)) &&
1438 fc_seq_lookup_recip(lport, ema->mp, fp) == FC_RJT_NONE)
1444 * fc_seq_release() - Release the hold
1445 * @sp: The sequence.
1447 static void fc_seq_release(struct fc_seq *sp)
1449 fc_exch_release(fc_seq_exch(sp));
1453 * fc_exch_recv_req() - Handler for an incoming request
1454 * @lport: The local port that received the request
1455 * @mp: The EM that the exchange is on
1456 * @fp: The request frame
1458 * This is used when the other end is originating the exchange
1461 static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp,
1462 struct fc_frame *fp)
1464 struct fc_frame_header *fh = fc_frame_header_get(fp);
1465 struct fc_seq *sp = NULL;
1466 struct fc_exch *ep = NULL;
1467 enum fc_pf_rjt_reason reject;
1469 /* We can have the wrong fc_lport at this point with NPIV, which is a
1470 * problem now that we know a new exchange needs to be allocated
1472 lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id));
1479 BUG_ON(fr_seq(fp)); /* XXX remove later */
1482 * If the RX_ID is 0xffff, don't allocate an exchange.
1483 * The upper-level protocol may request one later, if needed.
1485 if (fh->fh_rx_id == htons(FC_XID_UNKNOWN))
1486 return lport->tt.lport_recv(lport, fp);
1488 reject = fc_seq_lookup_recip(lport, mp, fp);
1489 if (reject == FC_RJT_NONE) {
1490 sp = fr_seq(fp); /* sequence will be held */
1491 ep = fc_seq_exch(sp);
1492 fc_seq_send_ack(sp, fp);
1493 ep->encaps = fr_encaps(fp);
1496 * Call the receive function.
1498 * The receive function may allocate a new sequence
1499 * over the old one, so we shouldn't change the
1500 * sequence after this.
1502 * The frame will be freed by the receive function.
1503 * If new exch resp handler is valid then call that
1506 if (!fc_invoke_resp(ep, sp, fp))
1507 lport->tt.lport_recv(lport, fp);
1508 fc_exch_release(ep); /* release from lookup */
1510 FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n",
1517 * fc_exch_recv_seq_resp() - Handler for an incoming response where the other
1518 * end is the originator of the sequence that is a
1519 * response to our initial exchange
1520 * @mp: The EM that the exchange is on
1521 * @fp: The response frame
1523 static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1525 struct fc_frame_header *fh = fc_frame_header_get(fp);
1532 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1534 atomic_inc(&mp->stats.xid_not_found);
1537 if (ep->esb_stat & ESB_ST_COMPLETE) {
1538 atomic_inc(&mp->stats.xid_not_found);
1541 if (ep->rxid == FC_XID_UNKNOWN)
1542 ep->rxid = ntohs(fh->fh_rx_id);
1543 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1544 atomic_inc(&mp->stats.xid_not_found);
1547 if (ep->did != ntoh24(fh->fh_s_id) &&
1548 ep->did != FC_FID_FLOGI) {
1549 atomic_inc(&mp->stats.xid_not_found);
1554 if (fc_sof_is_init(sof)) {
1555 sp->ssb_stat |= SSB_ST_RESP;
1556 sp->id = fh->fh_seq_id;
1557 } else if (sp->id != fh->fh_seq_id) {
1558 atomic_inc(&mp->stats.seq_not_found);
1562 f_ctl = ntoh24(fh->fh_f_ctl);
1565 spin_lock_bh(&ep->ex_lock);
1566 if (f_ctl & FC_FC_SEQ_INIT)
1567 ep->esb_stat |= ESB_ST_SEQ_INIT;
1568 spin_unlock_bh(&ep->ex_lock);
1570 if (fc_sof_needs_ack(sof))
1571 fc_seq_send_ack(sp, fp);
1573 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1574 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1575 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1576 spin_lock_bh(&ep->ex_lock);
1577 rc = fc_exch_done_locked(ep);
1578 WARN_ON(fc_seq_exch(sp) != ep);
1579 spin_unlock_bh(&ep->ex_lock);
1583 FC_EXCH_DBG(ep, "ep is completed already,"
1584 "hence skip calling the resp\n");
1590 * Call the receive function.
1591 * The sequence is held (has a refcnt) for us,
1592 * but not for the receive function.
1594 * The receive function may allocate a new sequence
1595 * over the old one, so we shouldn't change the
1596 * sequence after this.
1598 * The frame will be freed by the receive function.
1599 * If new exch resp handler is valid then call that
1602 if (!fc_invoke_resp(ep, sp, fp))
1606 fc_exch_release(ep);
1609 fc_exch_release(ep);
1615 * fc_exch_recv_resp() - Handler for a sequence where other end is
1616 * responding to our sequence
1617 * @mp: The EM that the exchange is on
1618 * @fp: The response frame
1620 static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1624 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1627 atomic_inc(&mp->stats.xid_not_found);
1629 atomic_inc(&mp->stats.non_bls_resp);
1635 * fc_exch_abts_resp() - Handler for a response to an ABT
1636 * @ep: The exchange that the frame is on
1637 * @fp: The response frame
1639 * This response would be to an ABTS cancelling an exchange or sequence.
1640 * The response can be either BA_ACC or BA_RJT
1642 static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1644 struct fc_frame_header *fh;
1645 struct fc_ba_acc *ap;
1649 int rc = 1, has_rec = 0;
1651 fh = fc_frame_header_get(fp);
1652 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1653 fc_exch_rctl_name(fh->fh_r_ctl));
1655 if (cancel_delayed_work_sync(&ep->timeout_work)) {
1656 FC_EXCH_DBG(ep, "Exchange timer canceled due to ABTS response\n");
1657 fc_exch_release(ep); /* release from pending timer hold */
1660 spin_lock_bh(&ep->ex_lock);
1661 switch (fh->fh_r_ctl) {
1662 case FC_RCTL_BA_ACC:
1663 ap = fc_frame_payload_get(fp, sizeof(*ap));
1668 * Decide whether to establish a Recovery Qualifier.
1669 * We do this if there is a non-empty SEQ_CNT range and
1670 * SEQ_ID is the same as the one we aborted.
1672 low = ntohs(ap->ba_low_seq_cnt);
1673 high = ntohs(ap->ba_high_seq_cnt);
1674 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1675 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1676 ap->ba_seq_id == ep->seq_id) && low != high) {
1677 ep->esb_stat |= ESB_ST_REC_QUAL;
1678 fc_exch_hold(ep); /* hold for recovery qualifier */
1682 case FC_RCTL_BA_RJT:
1688 /* do we need to do some other checks here. Can we reuse more of
1689 * fc_exch_recv_seq_resp
1693 * do we want to check END_SEQ as well as LAST_SEQ here?
1695 if (ep->fh_type != FC_TYPE_FCP &&
1696 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1697 rc = fc_exch_done_locked(ep);
1698 spin_unlock_bh(&ep->ex_lock);
1703 if (!fc_invoke_resp(ep, sp, fp))
1706 fc_exch_timer_set(ep, ep->r_a_tov);
1707 fc_exch_release(ep);
1711 * fc_exch_recv_bls() - Handler for a BLS sequence
1712 * @mp: The EM that the exchange is on
1713 * @fp: The request frame
1715 * The BLS frame is always a sequence initiated by the remote side.
1716 * We may be either the originator or recipient of the exchange.
1718 static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1720 struct fc_frame_header *fh;
1724 fh = fc_frame_header_get(fp);
1725 f_ctl = ntoh24(fh->fh_f_ctl);
1728 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1729 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1730 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1731 spin_lock_bh(&ep->ex_lock);
1732 ep->esb_stat |= ESB_ST_SEQ_INIT;
1733 spin_unlock_bh(&ep->ex_lock);
1735 if (f_ctl & FC_FC_SEQ_CTX) {
1737 * A response to a sequence we initiated.
1738 * This should only be ACKs for class 2 or F.
1740 switch (fh->fh_r_ctl) {
1746 FC_EXCH_DBG(ep, "BLS rctl %x - %s received\n",
1748 fc_exch_rctl_name(fh->fh_r_ctl));
1753 switch (fh->fh_r_ctl) {
1754 case FC_RCTL_BA_RJT:
1755 case FC_RCTL_BA_ACC:
1757 fc_exch_abts_resp(ep, fp);
1761 case FC_RCTL_BA_ABTS:
1762 fc_exch_recv_abts(ep, fp);
1764 default: /* ignore junk */
1770 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1774 * fc_seq_ls_acc() - Accept sequence with LS_ACC
1775 * @rx_fp: The received frame, not freed here.
1777 * If this fails due to allocation or transmit congestion, assume the
1778 * originator will repeat the sequence.
1780 static void fc_seq_ls_acc(struct fc_frame *rx_fp)
1782 struct fc_lport *lport;
1783 struct fc_els_ls_acc *acc;
1784 struct fc_frame *fp;
1786 lport = fr_dev(rx_fp);
1787 fp = fc_frame_alloc(lport, sizeof(*acc));
1790 acc = fc_frame_payload_get(fp, sizeof(*acc));
1791 memset(acc, 0, sizeof(*acc));
1792 acc->la_cmd = ELS_LS_ACC;
1793 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1794 lport->tt.frame_send(lport, fp);
1798 * fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT
1799 * @rx_fp: The received frame, not freed here.
1800 * @reason: The reason the sequence is being rejected
1801 * @explan: The explanation for the rejection
1803 * If this fails due to allocation or transmit congestion, assume the
1804 * originator will repeat the sequence.
1806 static void fc_seq_ls_rjt(struct fc_frame *rx_fp, enum fc_els_rjt_reason reason,
1807 enum fc_els_rjt_explan explan)
1809 struct fc_lport *lport;
1810 struct fc_els_ls_rjt *rjt;
1811 struct fc_frame *fp;
1813 lport = fr_dev(rx_fp);
1814 fp = fc_frame_alloc(lport, sizeof(*rjt));
1817 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1818 memset(rjt, 0, sizeof(*rjt));
1819 rjt->er_cmd = ELS_LS_RJT;
1820 rjt->er_reason = reason;
1821 rjt->er_explan = explan;
1822 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1823 lport->tt.frame_send(lport, fp);
1827 * fc_exch_reset() - Reset an exchange
1828 * @ep: The exchange to be reset
1830 * Note: May sleep if invoked from outside a response handler.
1832 static void fc_exch_reset(struct fc_exch *ep)
1837 spin_lock_bh(&ep->ex_lock);
1838 fc_exch_abort_locked(ep, 0);
1839 ep->state |= FC_EX_RST_CLEANUP;
1840 fc_exch_timer_cancel(ep);
1841 if (ep->esb_stat & ESB_ST_REC_QUAL)
1842 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1843 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1845 rc = fc_exch_done_locked(ep);
1846 spin_unlock_bh(&ep->ex_lock);
1853 FC_EXCH_DBG(ep, "ep is completed already,"
1854 "hence skip calling the resp\n");
1858 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_CLOSED));
1860 fc_seq_set_resp(sp, NULL, ep->arg);
1861 fc_exch_release(ep);
1865 * fc_exch_pool_reset() - Reset a per cpu exchange pool
1866 * @lport: The local port that the exchange pool is on
1867 * @pool: The exchange pool to be reset
1868 * @sid: The source ID
1869 * @did: The destination ID
1871 * Resets a per cpu exches pool, releasing all of its sequences
1872 * and exchanges. If sid is non-zero then reset only exchanges
1873 * we sourced from the local port's FID. If did is non-zero then
1874 * only reset exchanges destined for the local port's FID.
1876 static void fc_exch_pool_reset(struct fc_lport *lport,
1877 struct fc_exch_pool *pool,
1881 struct fc_exch *next;
1883 spin_lock_bh(&pool->lock);
1885 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1886 if ((lport == ep->lp) &&
1887 (sid == 0 || sid == ep->sid) &&
1888 (did == 0 || did == ep->did)) {
1890 spin_unlock_bh(&pool->lock);
1894 fc_exch_release(ep);
1895 spin_lock_bh(&pool->lock);
1898 * must restart loop incase while lock
1899 * was down multiple eps were released.
1904 pool->next_index = 0;
1905 pool->left = FC_XID_UNKNOWN;
1906 pool->right = FC_XID_UNKNOWN;
1907 spin_unlock_bh(&pool->lock);
1911 * fc_exch_mgr_reset() - Reset all EMs of a local port
1912 * @lport: The local port whose EMs are to be reset
1913 * @sid: The source ID
1914 * @did: The destination ID
1916 * Reset all EMs associated with a given local port. Release all
1917 * sequences and exchanges. If sid is non-zero then reset only the
1918 * exchanges sent from the local port's FID. If did is non-zero then
1919 * reset only exchanges destined for the local port's FID.
1921 void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1923 struct fc_exch_mgr_anchor *ema;
1926 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1927 for_each_possible_cpu(cpu)
1928 fc_exch_pool_reset(lport,
1929 per_cpu_ptr(ema->mp->pool, cpu),
1933 EXPORT_SYMBOL(fc_exch_mgr_reset);
1936 * fc_exch_lookup() - find an exchange
1937 * @lport: The local port
1938 * @xid: The exchange ID
1940 * Returns exchange pointer with hold for caller, or NULL if not found.
1942 static struct fc_exch *fc_exch_lookup(struct fc_lport *lport, u32 xid)
1944 struct fc_exch_mgr_anchor *ema;
1946 list_for_each_entry(ema, &lport->ema_list, ema_list)
1947 if (ema->mp->min_xid <= xid && xid <= ema->mp->max_xid)
1948 return fc_exch_find(ema->mp, xid);
1953 * fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests
1954 * @rfp: The REC frame, not freed here.
1956 * Note that the requesting port may be different than the S_ID in the request.
1958 static void fc_exch_els_rec(struct fc_frame *rfp)
1960 struct fc_lport *lport;
1961 struct fc_frame *fp;
1963 struct fc_els_rec *rp;
1964 struct fc_els_rec_acc *acc;
1965 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
1966 enum fc_els_rjt_explan explan;
1971 lport = fr_dev(rfp);
1972 rp = fc_frame_payload_get(rfp, sizeof(*rp));
1973 explan = ELS_EXPL_INV_LEN;
1976 sid = ntoh24(rp->rec_s_id);
1977 rxid = ntohs(rp->rec_rx_id);
1978 oxid = ntohs(rp->rec_ox_id);
1980 ep = fc_exch_lookup(lport,
1981 sid == fc_host_port_id(lport->host) ? oxid : rxid);
1982 explan = ELS_EXPL_OXID_RXID;
1985 if (ep->oid != sid || oxid != ep->oxid)
1987 if (rxid != FC_XID_UNKNOWN && rxid != ep->rxid)
1989 fp = fc_frame_alloc(lport, sizeof(*acc));
1993 acc = fc_frame_payload_get(fp, sizeof(*acc));
1994 memset(acc, 0, sizeof(*acc));
1995 acc->reca_cmd = ELS_LS_ACC;
1996 acc->reca_ox_id = rp->rec_ox_id;
1997 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
1998 acc->reca_rx_id = htons(ep->rxid);
1999 if (ep->sid == ep->oid)
2000 hton24(acc->reca_rfid, ep->did);
2002 hton24(acc->reca_rfid, ep->sid);
2003 acc->reca_fc4value = htonl(ep->seq.rec_data);
2004 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
2007 fc_fill_reply_hdr(fp, rfp, FC_RCTL_ELS_REP, 0);
2008 lport->tt.frame_send(lport, fp);
2010 fc_exch_release(ep);
2014 fc_exch_release(ep);
2016 fc_seq_ls_rjt(rfp, reason, explan);
2020 * fc_exch_rrq_resp() - Handler for RRQ responses
2021 * @sp: The sequence that the RRQ is on
2022 * @fp: The RRQ frame
2023 * @arg: The exchange that the RRQ is on
2025 * TODO: fix error handler.
2027 static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
2029 struct fc_exch *aborted_ep = arg;
2033 int err = PTR_ERR(fp);
2035 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
2037 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
2038 "frame error %d\n", err);
2042 op = fc_frame_payload_op(fp);
2047 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ\n");
2052 FC_EXCH_DBG(aborted_ep, "unexpected response op %x for RRQ\n",
2058 fc_exch_done(&aborted_ep->seq);
2059 /* drop hold for rec qual */
2060 fc_exch_release(aborted_ep);
2065 * fc_exch_seq_send() - Send a frame using a new exchange and sequence
2066 * @lport: The local port to send the frame on
2067 * @fp: The frame to be sent
2068 * @resp: The response handler for this request
2069 * @destructor: The destructor for the exchange
2070 * @arg: The argument to be passed to the response handler
2071 * @timer_msec: The timeout period for the exchange
2073 * The frame pointer with some of the header's fields must be
2074 * filled before calling this routine, those fields are:
2081 * - parameter or relative offset
2083 static struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
2084 struct fc_frame *fp,
2085 void (*resp)(struct fc_seq *,
2086 struct fc_frame *fp,
2088 void (*destructor)(struct fc_seq *,
2090 void *arg, u32 timer_msec)
2093 struct fc_seq *sp = NULL;
2094 struct fc_frame_header *fh;
2095 struct fc_fcp_pkt *fsp = NULL;
2098 ep = fc_exch_alloc(lport, fp);
2103 ep->esb_stat |= ESB_ST_SEQ_INIT;
2104 fh = fc_frame_header_get(fp);
2105 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
2107 ep->destructor = destructor;
2109 ep->r_a_tov = FC_DEF_R_A_TOV;
2113 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
2114 ep->f_ctl = ntoh24(fh->fh_f_ctl);
2115 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
2118 if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD) {
2120 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
2123 if (unlikely(lport->tt.frame_send(lport, fp)))
2127 fc_exch_timer_set_locked(ep, timer_msec);
2128 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
2130 if (ep->f_ctl & FC_FC_SEQ_INIT)
2131 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
2132 spin_unlock_bh(&ep->ex_lock);
2136 fc_fcp_ddp_done(fsp);
2137 rc = fc_exch_done_locked(ep);
2138 spin_unlock_bh(&ep->ex_lock);
2145 * fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command
2146 * @ep: The exchange to send the RRQ on
2148 * This tells the remote port to stop blocking the use of
2149 * the exchange and the seq_cnt range.
2151 static void fc_exch_rrq(struct fc_exch *ep)
2153 struct fc_lport *lport;
2154 struct fc_els_rrq *rrq;
2155 struct fc_frame *fp;
2160 fp = fc_frame_alloc(lport, sizeof(*rrq));
2164 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
2165 memset(rrq, 0, sizeof(*rrq));
2166 rrq->rrq_cmd = ELS_RRQ;
2167 hton24(rrq->rrq_s_id, ep->sid);
2168 rrq->rrq_ox_id = htons(ep->oxid);
2169 rrq->rrq_rx_id = htons(ep->rxid);
2172 if (ep->esb_stat & ESB_ST_RESP)
2175 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
2176 lport->port_id, FC_TYPE_ELS,
2177 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
2179 if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep,
2184 spin_lock_bh(&ep->ex_lock);
2185 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
2186 spin_unlock_bh(&ep->ex_lock);
2187 /* drop hold for rec qual */
2188 fc_exch_release(ep);
2191 ep->esb_stat |= ESB_ST_REC_QUAL;
2192 fc_exch_timer_set_locked(ep, ep->r_a_tov);
2193 spin_unlock_bh(&ep->ex_lock);
2197 * fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests
2198 * @fp: The RRQ frame, not freed here.
2200 static void fc_exch_els_rrq(struct fc_frame *fp)
2202 struct fc_lport *lport;
2203 struct fc_exch *ep = NULL; /* request or subject exchange */
2204 struct fc_els_rrq *rp;
2207 enum fc_els_rjt_explan explan;
2210 rp = fc_frame_payload_get(fp, sizeof(*rp));
2211 explan = ELS_EXPL_INV_LEN;
2216 * lookup subject exchange.
2218 sid = ntoh24(rp->rrq_s_id); /* subject source */
2219 xid = fc_host_port_id(lport->host) == sid ?
2220 ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
2221 ep = fc_exch_lookup(lport, xid);
2222 explan = ELS_EXPL_OXID_RXID;
2225 spin_lock_bh(&ep->ex_lock);
2226 if (ep->oxid != ntohs(rp->rrq_ox_id))
2228 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
2229 ep->rxid != FC_XID_UNKNOWN)
2231 explan = ELS_EXPL_SID;
2236 * Clear Recovery Qualifier state, and cancel timer if complete.
2238 if (ep->esb_stat & ESB_ST_REC_QUAL) {
2239 ep->esb_stat &= ~ESB_ST_REC_QUAL;
2240 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
2242 if (ep->esb_stat & ESB_ST_COMPLETE)
2243 fc_exch_timer_cancel(ep);
2245 spin_unlock_bh(&ep->ex_lock);
2254 spin_unlock_bh(&ep->ex_lock);
2256 fc_seq_ls_rjt(fp, ELS_RJT_LOGIC, explan);
2259 fc_exch_release(ep); /* drop hold from fc_exch_find */
2263 * fc_exch_update_stats() - update exches stats to lport
2264 * @lport: The local port to update exchange manager stats
2266 void fc_exch_update_stats(struct fc_lport *lport)
2268 struct fc_host_statistics *st;
2269 struct fc_exch_mgr_anchor *ema;
2270 struct fc_exch_mgr *mp;
2272 st = &lport->host_stats;
2274 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2276 st->fc_no_free_exch += atomic_read(&mp->stats.no_free_exch);
2277 st->fc_no_free_exch_xid +=
2278 atomic_read(&mp->stats.no_free_exch_xid);
2279 st->fc_xid_not_found += atomic_read(&mp->stats.xid_not_found);
2280 st->fc_xid_busy += atomic_read(&mp->stats.xid_busy);
2281 st->fc_seq_not_found += atomic_read(&mp->stats.seq_not_found);
2282 st->fc_non_bls_resp += atomic_read(&mp->stats.non_bls_resp);
2285 EXPORT_SYMBOL(fc_exch_update_stats);
2288 * fc_exch_mgr_add() - Add an exchange manager to a local port's list of EMs
2289 * @lport: The local port to add the exchange manager to
2290 * @mp: The exchange manager to be added to the local port
2291 * @match: The match routine that indicates when this EM should be used
2293 struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
2294 struct fc_exch_mgr *mp,
2295 bool (*match)(struct fc_frame *))
2297 struct fc_exch_mgr_anchor *ema;
2299 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
2305 /* add EM anchor to EM anchors list */
2306 list_add_tail(&ema->ema_list, &lport->ema_list);
2307 kref_get(&mp->kref);
2310 EXPORT_SYMBOL(fc_exch_mgr_add);
2313 * fc_exch_mgr_destroy() - Destroy an exchange manager
2314 * @kref: The reference to the EM to be destroyed
2316 static void fc_exch_mgr_destroy(struct kref *kref)
2318 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
2320 mempool_destroy(mp->ep_pool);
2321 free_percpu(mp->pool);
2326 * fc_exch_mgr_del() - Delete an EM from a local port's list
2327 * @ema: The exchange manager anchor identifying the EM to be deleted
2329 void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
2331 /* remove EM anchor from EM anchors list */
2332 list_del(&ema->ema_list);
2333 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
2336 EXPORT_SYMBOL(fc_exch_mgr_del);
2339 * fc_exch_mgr_list_clone() - Share all exchange manager objects
2340 * @src: Source lport to clone exchange managers from
2341 * @dst: New lport that takes references to all the exchange managers
2343 int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)
2345 struct fc_exch_mgr_anchor *ema, *tmp;
2347 list_for_each_entry(ema, &src->ema_list, ema_list) {
2348 if (!fc_exch_mgr_add(dst, ema->mp, ema->match))
2353 list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)
2354 fc_exch_mgr_del(ema);
2357 EXPORT_SYMBOL(fc_exch_mgr_list_clone);
2360 * fc_exch_mgr_alloc() - Allocate an exchange manager
2361 * @lport: The local port that the new EM will be associated with
2362 * @class: The default FC class for new exchanges
2363 * @min_xid: The minimum XID for exchanges from the new EM
2364 * @max_xid: The maximum XID for exchanges from the new EM
2365 * @match: The match routine for the new EM
2367 struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport,
2368 enum fc_class class,
2369 u16 min_xid, u16 max_xid,
2370 bool (*match)(struct fc_frame *))
2372 struct fc_exch_mgr *mp;
2373 u16 pool_exch_range;
2376 struct fc_exch_pool *pool;
2378 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
2379 (min_xid & fc_cpu_mask) != 0) {
2380 FC_LPORT_DBG(lport, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
2386 * allocate memory for EM
2388 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
2393 /* adjust em exch xid range for offload */
2394 mp->min_xid = min_xid;
2396 /* reduce range so per cpu pool fits into PCPU_MIN_UNIT_SIZE pool */
2397 pool_exch_range = (PCPU_MIN_UNIT_SIZE - sizeof(*pool)) /
2398 sizeof(struct fc_exch *);
2399 if ((max_xid - min_xid + 1) / (fc_cpu_mask + 1) > pool_exch_range) {
2400 mp->max_xid = pool_exch_range * (fc_cpu_mask + 1) +
2403 mp->max_xid = max_xid;
2404 pool_exch_range = (mp->max_xid - mp->min_xid + 1) /
2408 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
2413 * Setup per cpu exch pool with entire exchange id range equally
2414 * divided across all cpus. The exch pointers array memory is
2415 * allocated for exch range per pool.
2417 mp->pool_max_index = pool_exch_range - 1;
2420 * Allocate and initialize per cpu exch pool
2422 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
2423 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
2426 for_each_possible_cpu(cpu) {
2427 pool = per_cpu_ptr(mp->pool, cpu);
2428 pool->next_index = 0;
2429 pool->left = FC_XID_UNKNOWN;
2430 pool->right = FC_XID_UNKNOWN;
2431 spin_lock_init(&pool->lock);
2432 INIT_LIST_HEAD(&pool->ex_list);
2435 kref_init(&mp->kref);
2436 if (!fc_exch_mgr_add(lport, mp, match)) {
2437 free_percpu(mp->pool);
2442 * Above kref_init() sets mp->kref to 1 and then
2443 * call to fc_exch_mgr_add incremented mp->kref again,
2444 * so adjust that extra increment.
2446 kref_put(&mp->kref, fc_exch_mgr_destroy);
2450 mempool_destroy(mp->ep_pool);
2455 EXPORT_SYMBOL(fc_exch_mgr_alloc);
2458 * fc_exch_mgr_free() - Free all exchange managers on a local port
2459 * @lport: The local port whose EMs are to be freed
2461 void fc_exch_mgr_free(struct fc_lport *lport)
2463 struct fc_exch_mgr_anchor *ema, *next;
2465 flush_workqueue(fc_exch_workqueue);
2466 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
2467 fc_exch_mgr_del(ema);
2469 EXPORT_SYMBOL(fc_exch_mgr_free);
2472 * fc_find_ema() - Lookup and return appropriate Exchange Manager Anchor depending
2475 * @lport: The local port the frame was received on
2476 * @fh: The received frame header
2478 static struct fc_exch_mgr_anchor *fc_find_ema(u32 f_ctl,
2479 struct fc_lport *lport,
2480 struct fc_frame_header *fh)
2482 struct fc_exch_mgr_anchor *ema;
2485 if (f_ctl & FC_FC_EX_CTX)
2486 xid = ntohs(fh->fh_ox_id);
2488 xid = ntohs(fh->fh_rx_id);
2489 if (xid == FC_XID_UNKNOWN)
2490 return list_entry(lport->ema_list.prev,
2491 typeof(*ema), ema_list);
2494 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2495 if ((xid >= ema->mp->min_xid) &&
2496 (xid <= ema->mp->max_xid))
2502 * fc_exch_recv() - Handler for received frames
2503 * @lport: The local port the frame was received on
2504 * @fp: The received frame
2506 void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)
2508 struct fc_frame_header *fh = fc_frame_header_get(fp);
2509 struct fc_exch_mgr_anchor *ema;
2513 if (!lport || lport->state == LPORT_ST_DISABLED) {
2514 FC_LIBFC_DBG("Receiving frames for an lport that "
2515 "has not been initialized correctly\n");
2520 f_ctl = ntoh24(fh->fh_f_ctl);
2521 ema = fc_find_ema(f_ctl, lport, fh);
2523 FC_LPORT_DBG(lport, "Unable to find Exchange Manager Anchor,"
2524 "fc_ctl <0x%x>, xid <0x%x>\n",
2526 (f_ctl & FC_FC_EX_CTX) ?
2527 ntohs(fh->fh_ox_id) :
2528 ntohs(fh->fh_rx_id));
2534 * If frame is marked invalid, just drop it.
2536 switch (fr_eof(fp)) {
2538 if (f_ctl & FC_FC_END_SEQ)
2539 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2542 if (fh->fh_type == FC_TYPE_BLS)
2543 fc_exch_recv_bls(ema->mp, fp);
2544 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2546 fc_exch_recv_seq_resp(ema->mp, fp);
2547 else if (f_ctl & FC_FC_SEQ_CTX)
2548 fc_exch_recv_resp(ema->mp, fp);
2549 else /* no EX_CTX and no SEQ_CTX */
2550 fc_exch_recv_req(lport, ema->mp, fp);
2553 FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)",
2558 EXPORT_SYMBOL(fc_exch_recv);
2561 * fc_exch_init() - Initialize the exchange layer for a local port
2562 * @lport: The local port to initialize the exchange layer for
2564 int fc_exch_init(struct fc_lport *lport)
2566 if (!lport->tt.seq_start_next)
2567 lport->tt.seq_start_next = fc_seq_start_next;
2569 if (!lport->tt.seq_set_resp)
2570 lport->tt.seq_set_resp = fc_seq_set_resp;
2572 if (!lport->tt.exch_seq_send)
2573 lport->tt.exch_seq_send = fc_exch_seq_send;
2575 if (!lport->tt.seq_send)
2576 lport->tt.seq_send = fc_seq_send;
2578 if (!lport->tt.seq_els_rsp_send)
2579 lport->tt.seq_els_rsp_send = fc_seq_els_rsp_send;
2581 if (!lport->tt.exch_done)
2582 lport->tt.exch_done = fc_exch_done;
2584 if (!lport->tt.exch_mgr_reset)
2585 lport->tt.exch_mgr_reset = fc_exch_mgr_reset;
2587 if (!lport->tt.seq_exch_abort)
2588 lport->tt.seq_exch_abort = fc_seq_exch_abort;
2590 if (!lport->tt.seq_assign)
2591 lport->tt.seq_assign = fc_seq_assign;
2593 if (!lport->tt.seq_release)
2594 lport->tt.seq_release = fc_seq_release;
2598 EXPORT_SYMBOL(fc_exch_init);
2601 * fc_setup_exch_mgr() - Setup an exchange manager
2603 int fc_setup_exch_mgr(void)
2605 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2606 0, SLAB_HWCACHE_ALIGN, NULL);
2611 * Initialize fc_cpu_mask and fc_cpu_order. The
2612 * fc_cpu_mask is set for nr_cpu_ids rounded up
2613 * to order of 2's * power and order is stored
2614 * in fc_cpu_order as this is later required in
2615 * mapping between an exch id and exch array index
2616 * in per cpu exch pool.
2618 * This round up is required to align fc_cpu_mask
2619 * to exchange id's lower bits such that all incoming
2620 * frames of an exchange gets delivered to the same
2621 * cpu on which exchange originated by simple bitwise
2622 * AND operation between fc_cpu_mask and exchange id.
2624 fc_cpu_order = ilog2(roundup_pow_of_two(nr_cpu_ids));
2625 fc_cpu_mask = (1 << fc_cpu_order) - 1;
2627 fc_exch_workqueue = create_singlethread_workqueue("fc_exch_workqueue");
2628 if (!fc_exch_workqueue)
2632 kmem_cache_destroy(fc_em_cachep);
2637 * fc_destroy_exch_mgr() - Destroy an exchange manager
2639 void fc_destroy_exch_mgr(void)
2641 destroy_workqueue(fc_exch_workqueue);
2642 kmem_cache_destroy(fc_em_cachep);