1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright(c) 2007 Intel Corporation. All rights reserved.
4 * Copyright(c) 2008 Red Hat, Inc. All rights reserved.
5 * Copyright(c) 2008 Mike Christie
7 * Maintained at www.Open-FCoE.org
11 * Fibre Channel exchange and sequence handling.
14 #include <linux/timer.h>
15 #include <linux/slab.h>
16 #include <linux/err.h>
17 #include <linux/export.h>
18 #include <linux/log2.h>
20 #include <scsi/fc/fc_fc2.h>
22 #include <scsi/libfc.h>
23 #include <scsi/fc_encode.h>
27 u16 fc_cpu_mask; /* cpu mask for possible cpus */
28 EXPORT_SYMBOL(fc_cpu_mask);
29 static u16 fc_cpu_order; /* 2's power to represent total possible cpus */
30 static struct kmem_cache *fc_em_cachep; /* cache for exchanges */
31 static struct workqueue_struct *fc_exch_workqueue;
34 * Structure and function definitions for managing Fibre Channel Exchanges
37 * The three primary structures used here are fc_exch_mgr, fc_exch, and fc_seq.
39 * fc_exch_mgr holds the exchange state for an N port
41 * fc_exch holds state for one exchange and links to its active sequence.
43 * fc_seq holds the state for an individual sequence.
47 * struct fc_exch_pool - Per cpu exchange pool
48 * @next_index: Next possible free exchange index
49 * @total_exches: Total allocated exchanges
50 * @lock: Exch pool lock
51 * @ex_list: List of exchanges
52 * @left: Cache of free slot in exch array
53 * @right: Cache of free slot in exch array
55 * This structure manages per cpu exchanges in array of exchange pointers.
56 * This array is allocated followed by struct fc_exch_pool memory for
57 * assigned range of exchanges to per cpu pool.
61 struct list_head ex_list;
67 } ____cacheline_aligned_in_smp;
70 * struct fc_exch_mgr - The Exchange Manager (EM).
71 * @class: Default class for new sequences
72 * @kref: Reference counter
73 * @min_xid: Minimum exchange ID
74 * @max_xid: Maximum exchange ID
75 * @ep_pool: Reserved exchange pointers
76 * @pool_max_index: Max exch array index in exch pool
77 * @pool: Per cpu exch pool
78 * @lport: Local exchange port
79 * @stats: Statistics structure
81 * This structure is the center for creating exchanges and sequences.
82 * It manages the allocation of exchange IDs.
85 struct fc_exch_pool __percpu *pool;
87 struct fc_lport *lport;
95 atomic_t no_free_exch;
96 atomic_t no_free_exch_xid;
97 atomic_t xid_not_found;
99 atomic_t seq_not_found;
100 atomic_t non_bls_resp;
105 * struct fc_exch_mgr_anchor - primary structure for list of EMs
106 * @ema_list: Exchange Manager Anchor list
107 * @mp: Exchange Manager associated with this anchor
108 * @match: Routine to determine if this anchor's EM should be used
110 * When walking the list of anchors the match routine will be called
111 * for each anchor to determine if that EM should be used. The last
112 * anchor in the list will always match to handle any exchanges not
113 * handled by other EMs. The non-default EMs would be added to the
114 * anchor list by HW that provides offloads.
116 struct fc_exch_mgr_anchor {
117 struct list_head ema_list;
118 struct fc_exch_mgr *mp;
119 bool (*match)(struct fc_frame *);
122 static void fc_exch_rrq(struct fc_exch *);
123 static void fc_seq_ls_acc(struct fc_frame *);
124 static void fc_seq_ls_rjt(struct fc_frame *, enum fc_els_rjt_reason,
125 enum fc_els_rjt_explan);
126 static void fc_exch_els_rec(struct fc_frame *);
127 static void fc_exch_els_rrq(struct fc_frame *);
130 * Internal implementation notes.
132 * The exchange manager is one by default in libfc but LLD may choose
133 * to have one per CPU. The sequence manager is one per exchange manager
134 * and currently never separated.
136 * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field
137 * assigned by the Sequence Initiator that shall be unique for a specific
138 * D_ID and S_ID pair while the Sequence is open." Note that it isn't
139 * qualified by exchange ID, which one might think it would be.
140 * In practice this limits the number of open sequences and exchanges to 256
141 * per session. For most targets we could treat this limit as per exchange.
143 * The exchange and its sequence are freed when the last sequence is received.
144 * It's possible for the remote port to leave an exchange open without
145 * sending any sequences.
147 * Notes on reference counts:
149 * Exchanges are reference counted and exchange gets freed when the reference
150 * count becomes zero.
153 * Sequences are timed out for E_D_TOV and R_A_TOV.
155 * Sequence event handling:
157 * The following events may occur on initiator sequences:
160 * For now, the whole thing is sent.
162 * This applies only to class F.
163 * The sequence is marked complete.
165 * The upper layer calls fc_exch_done() when done
166 * with exchange and sequence tuple.
167 * RX-inferred completion.
168 * When we receive the next sequence on the same exchange, we can
169 * retire the previous sequence ID. (XXX not implemented).
171 * R_A_TOV frees the sequence ID. If we're waiting for ACK,
172 * E_D_TOV causes abort and calls upper layer response handler
173 * with FC_EX_TIMEOUT error.
179 * The following events may occur on recipient sequences:
182 * Allocate sequence for first frame received.
183 * Hold during receive handler.
184 * Release when final frame received.
185 * Keep status of last N of these for the ELS RES command. XXX TBD.
187 * Deallocate sequence
191 * For now, we neglect conditions where only part of a sequence was
192 * received or transmitted, or where out-of-order receipt is detected.
198 * The EM code run in a per-CPU worker thread.
200 * To protect against concurrency between a worker thread code and timers,
201 * sequence allocation and deallocation must be locked.
202 * - exchange refcnt can be done atomicly without locks.
203 * - sequence allocation must be locked by exch lock.
204 * - If the EM pool lock and ex_lock must be taken at the same time, then the
205 * EM pool lock must be taken before the ex_lock.
209 * opcode names for debugging.
211 static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;
214 * fc_exch_name_lookup() - Lookup name by opcode
215 * @op: Opcode to be looked up
216 * @table: Opcode/name table
217 * @max_index: Index not to be exceeded
219 * This routine is used to determine a human-readable string identifying
222 static inline const char *fc_exch_name_lookup(unsigned int op, char **table,
223 unsigned int max_index)
225 const char *name = NULL;
235 * fc_exch_rctl_name() - Wrapper routine for fc_exch_name_lookup()
236 * @op: The opcode to be looked up
238 static const char *fc_exch_rctl_name(unsigned int op)
240 return fc_exch_name_lookup(op, fc_exch_rctl_names,
241 ARRAY_SIZE(fc_exch_rctl_names));
245 * fc_exch_hold() - Increment an exchange's reference count
246 * @ep: Echange to be held
248 static inline void fc_exch_hold(struct fc_exch *ep)
250 atomic_inc(&ep->ex_refcnt);
254 * fc_exch_setup_hdr() - Initialize a FC header by initializing some fields
255 * and determine SOF and EOF.
256 * @ep: The exchange to that will use the header
257 * @fp: The frame whose header is to be modified
258 * @f_ctl: F_CTL bits that will be used for the frame header
260 * The fields initialized by this routine are: fh_ox_id, fh_rx_id,
261 * fh_seq_id, fh_seq_cnt and the SOF and EOF.
263 static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,
266 struct fc_frame_header *fh = fc_frame_header_get(fp);
269 fr_sof(fp) = ep->class;
271 fr_sof(fp) = fc_sof_normal(ep->class);
273 if (f_ctl & FC_FC_END_SEQ) {
274 fr_eof(fp) = FC_EOF_T;
275 if (fc_sof_needs_ack(ep->class))
276 fr_eof(fp) = FC_EOF_N;
279 * The number of fill bytes to make the length a 4-byte
280 * multiple is the low order 2-bits of the f_ctl.
281 * The fill itself will have been cleared by the frame
283 * After this, the length will be even, as expected by
286 fill = fr_len(fp) & 3;
289 /* TODO, this may be a problem with fragmented skb */
290 skb_put(fp_skb(fp), fill);
291 hton24(fh->fh_f_ctl, f_ctl | fill);
294 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
295 fr_eof(fp) = FC_EOF_N;
298 /* Initialize remaining fh fields from fc_fill_fc_hdr */
299 fh->fh_ox_id = htons(ep->oxid);
300 fh->fh_rx_id = htons(ep->rxid);
301 fh->fh_seq_id = ep->seq.id;
302 fh->fh_seq_cnt = htons(ep->seq.cnt);
306 * fc_exch_release() - Decrement an exchange's reference count
307 * @ep: Exchange to be released
309 * If the reference count reaches zero and the exchange is complete,
312 static void fc_exch_release(struct fc_exch *ep)
314 struct fc_exch_mgr *mp;
316 if (atomic_dec_and_test(&ep->ex_refcnt)) {
319 ep->destructor(&ep->seq, ep->arg);
320 WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));
321 mempool_free(ep, mp->ep_pool);
326 * fc_exch_timer_cancel() - cancel exch timer
327 * @ep: The exchange whose timer to be canceled
329 static inline void fc_exch_timer_cancel(struct fc_exch *ep)
331 if (cancel_delayed_work(&ep->timeout_work)) {
332 FC_EXCH_DBG(ep, "Exchange timer canceled\n");
333 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
338 * fc_exch_timer_set_locked() - Start a timer for an exchange w/ the
339 * the exchange lock held
340 * @ep: The exchange whose timer will start
341 * @timer_msec: The timeout period
343 * Used for upper level protocols to time out the exchange.
344 * The timer is cancelled when it fires or when the exchange completes.
346 static inline void fc_exch_timer_set_locked(struct fc_exch *ep,
347 unsigned int timer_msec)
349 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
352 FC_EXCH_DBG(ep, "Exchange timer armed : %d msecs\n", timer_msec);
354 fc_exch_hold(ep); /* hold for timer */
355 if (!queue_delayed_work(fc_exch_workqueue, &ep->timeout_work,
356 msecs_to_jiffies(timer_msec))) {
357 FC_EXCH_DBG(ep, "Exchange already queued\n");
363 * fc_exch_timer_set() - Lock the exchange and set the timer
364 * @ep: The exchange whose timer will start
365 * @timer_msec: The timeout period
367 static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec)
369 spin_lock_bh(&ep->ex_lock);
370 fc_exch_timer_set_locked(ep, timer_msec);
371 spin_unlock_bh(&ep->ex_lock);
375 * fc_exch_done_locked() - Complete an exchange with the exchange lock held
376 * @ep: The exchange that is complete
378 * Note: May sleep if invoked from outside a response handler.
380 static int fc_exch_done_locked(struct fc_exch *ep)
385 * We must check for completion in case there are two threads
386 * tyring to complete this. But the rrq code will reuse the
387 * ep, and in that case we only clear the resp and set it as
388 * complete, so it can be reused by the timer to send the rrq.
390 if (ep->state & FC_EX_DONE)
392 ep->esb_stat |= ESB_ST_COMPLETE;
394 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
395 ep->state |= FC_EX_DONE;
396 fc_exch_timer_cancel(ep);
402 static struct fc_exch fc_quarantine_exch;
405 * fc_exch_ptr_get() - Return an exchange from an exchange pool
406 * @pool: Exchange Pool to get an exchange from
407 * @index: Index of the exchange within the pool
409 * Use the index to get an exchange from within an exchange pool. exches
410 * will point to an array of exchange pointers. The index will select
411 * the exchange within the array.
413 static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,
416 struct fc_exch **exches = (struct fc_exch **)(pool + 1);
417 return exches[index];
421 * fc_exch_ptr_set() - Assign an exchange to a slot in an exchange pool
422 * @pool: The pool to assign the exchange to
423 * @index: The index in the pool where the exchange will be assigned
424 * @ep: The exchange to assign to the pool
426 static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
429 ((struct fc_exch **)(pool + 1))[index] = ep;
433 * fc_exch_delete() - Delete an exchange
434 * @ep: The exchange to be deleted
436 static void fc_exch_delete(struct fc_exch *ep)
438 struct fc_exch_pool *pool;
442 spin_lock_bh(&pool->lock);
443 WARN_ON(pool->total_exches <= 0);
444 pool->total_exches--;
446 /* update cache of free slot */
447 index = (ep->xid - ep->em->min_xid) >> fc_cpu_order;
448 if (!(ep->state & FC_EX_QUARANTINE)) {
449 if (pool->left == FC_XID_UNKNOWN)
451 else if (pool->right == FC_XID_UNKNOWN)
454 pool->next_index = index;
455 fc_exch_ptr_set(pool, index, NULL);
457 fc_exch_ptr_set(pool, index, &fc_quarantine_exch);
459 list_del(&ep->ex_list);
460 spin_unlock_bh(&pool->lock);
461 fc_exch_release(ep); /* drop hold for exch in mp */
464 static int fc_seq_send_locked(struct fc_lport *lport, struct fc_seq *sp,
468 struct fc_frame_header *fh = fc_frame_header_get(fp);
471 u8 fh_type = fh->fh_type;
473 ep = fc_seq_exch(sp);
475 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL)) {
480 WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT));
482 f_ctl = ntoh24(fh->fh_f_ctl);
483 fc_exch_setup_hdr(ep, fp, f_ctl);
484 fr_encaps(fp) = ep->encaps;
487 * update sequence count if this frame is carrying
488 * multiple FC frames when sequence offload is enabled
491 if (fr_max_payload(fp))
492 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),
500 error = lport->tt.frame_send(lport, fp);
502 if (fh_type == FC_TYPE_BLS)
506 * Update the exchange and sequence flags,
507 * assuming all frames for the sequence have been sent.
508 * We can only be called to send once for each sequence.
510 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
511 if (f_ctl & FC_FC_SEQ_INIT)
512 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
518 * fc_seq_send() - Send a frame using existing sequence/exchange pair
519 * @lport: The local port that the exchange will be sent on
520 * @sp: The sequence to be sent
521 * @fp: The frame to be sent on the exchange
523 * Note: The frame will be freed either by a direct call to fc_frame_free(fp)
524 * or indirectly by calling libfc_function_template.frame_send().
526 int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp, struct fc_frame *fp)
530 ep = fc_seq_exch(sp);
531 spin_lock_bh(&ep->ex_lock);
532 error = fc_seq_send_locked(lport, sp, fp);
533 spin_unlock_bh(&ep->ex_lock);
536 EXPORT_SYMBOL(fc_seq_send);
539 * fc_seq_alloc() - Allocate a sequence for a given exchange
540 * @ep: The exchange to allocate a new sequence for
541 * @seq_id: The sequence ID to be used
543 * We don't support multiple originated sequences on the same exchange.
544 * By implication, any previously originated sequence on this exchange
545 * is complete, and we reallocate the same sequence.
547 static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
559 * fc_seq_start_next_locked() - Allocate a new sequence on the same
560 * exchange as the supplied sequence
561 * @sp: The sequence/exchange to get a new sequence for
563 static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
565 struct fc_exch *ep = fc_seq_exch(sp);
567 sp = fc_seq_alloc(ep, ep->seq_id++);
568 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
574 * fc_seq_start_next() - Lock the exchange and get a new sequence
575 * for a given sequence/exchange pair
576 * @sp: The sequence/exchange to get a new exchange for
578 struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
580 struct fc_exch *ep = fc_seq_exch(sp);
582 spin_lock_bh(&ep->ex_lock);
583 sp = fc_seq_start_next_locked(sp);
584 spin_unlock_bh(&ep->ex_lock);
588 EXPORT_SYMBOL(fc_seq_start_next);
591 * Set the response handler for the exchange associated with a sequence.
593 * Note: May sleep if invoked from outside a response handler.
595 void fc_seq_set_resp(struct fc_seq *sp,
596 void (*resp)(struct fc_seq *, struct fc_frame *, void *),
599 struct fc_exch *ep = fc_seq_exch(sp);
602 spin_lock_bh(&ep->ex_lock);
603 while (ep->resp_active && ep->resp_task != current) {
604 prepare_to_wait(&ep->resp_wq, &wait, TASK_UNINTERRUPTIBLE);
605 spin_unlock_bh(&ep->ex_lock);
609 spin_lock_bh(&ep->ex_lock);
611 finish_wait(&ep->resp_wq, &wait);
614 spin_unlock_bh(&ep->ex_lock);
616 EXPORT_SYMBOL(fc_seq_set_resp);
619 * fc_exch_abort_locked() - Abort an exchange
620 * @ep: The exchange to be aborted
621 * @timer_msec: The period of time to wait before aborting
623 * Abort an exchange and sequence. Generally called because of a
624 * exchange timeout or an abort from the upper layer.
626 * A timer_msec can be specified for abort timeout, if non-zero
627 * timer_msec value is specified then exchange resp handler
628 * will be called with timeout error if no response to abort.
630 * Locking notes: Called with exch lock held
632 * Return value: 0 on success else error code
634 static int fc_exch_abort_locked(struct fc_exch *ep,
635 unsigned int timer_msec)
641 FC_EXCH_DBG(ep, "exch: abort, time %d msecs\n", timer_msec);
642 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
643 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
644 FC_EXCH_DBG(ep, "exch: already completed esb %x state %x\n",
645 ep->esb_stat, ep->state);
650 * Send the abort on a new sequence if possible.
652 sp = fc_seq_start_next_locked(&ep->seq);
657 fc_exch_timer_set_locked(ep, timer_msec);
661 * Send an abort for the sequence that timed out.
663 fp = fc_frame_alloc(ep->lp, 0);
665 ep->esb_stat |= ESB_ST_SEQ_INIT;
666 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
667 FC_TYPE_BLS, FC_FC_END_SEQ |
669 error = fc_seq_send_locked(ep->lp, sp, fp);
675 * If not logged into the fabric, don't send ABTS but leave
676 * sequence active until next timeout.
680 ep->esb_stat |= ESB_ST_ABNORMAL;
685 * fc_seq_exch_abort() - Abort an exchange and sequence
686 * @req_sp: The sequence to be aborted
687 * @timer_msec: The period of time to wait before aborting
689 * Generally called because of a timeout or an abort from the upper layer.
691 * Return value: 0 on success else error code
693 int fc_seq_exch_abort(const struct fc_seq *req_sp, unsigned int timer_msec)
698 ep = fc_seq_exch(req_sp);
699 spin_lock_bh(&ep->ex_lock);
700 error = fc_exch_abort_locked(ep, timer_msec);
701 spin_unlock_bh(&ep->ex_lock);
706 * fc_invoke_resp() - invoke ep->resp()
707 * @ep: The exchange to be operated on
708 * @fp: The frame pointer to pass through to ->resp()
709 * @sp: The sequence pointer to pass through to ->resp()
712 * It is assumed that after initialization finished (this means the
713 * first unlock of ex_lock after fc_exch_alloc()) ep->resp and ep->arg are
714 * modified only via fc_seq_set_resp(). This guarantees that none of these
715 * two variables changes if ep->resp_active > 0.
717 * If an fc_seq_set_resp() call is busy modifying ep->resp and ep->arg when
718 * this function is invoked, the first spin_lock_bh() call in this function
719 * will wait until fc_seq_set_resp() has finished modifying these variables.
721 * Since fc_exch_done() invokes fc_seq_set_resp() it is guaranteed that that
722 * ep->resp() won't be invoked after fc_exch_done() has returned.
724 * The response handler itself may invoke fc_exch_done(), which will clear the
728 * Returns true if and only if ep->resp has been invoked.
730 static bool fc_invoke_resp(struct fc_exch *ep, struct fc_seq *sp,
733 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
737 spin_lock_bh(&ep->ex_lock);
739 if (ep->resp_task != current)
740 ep->resp_task = !ep->resp_task ? current : NULL;
743 spin_unlock_bh(&ep->ex_lock);
750 spin_lock_bh(&ep->ex_lock);
751 if (--ep->resp_active == 0)
752 ep->resp_task = NULL;
753 spin_unlock_bh(&ep->ex_lock);
755 if (ep->resp_active == 0)
756 wake_up(&ep->resp_wq);
762 * fc_exch_timeout() - Handle exchange timer expiration
763 * @work: The work_struct identifying the exchange that timed out
765 static void fc_exch_timeout(struct work_struct *work)
767 struct fc_exch *ep = container_of(work, struct fc_exch,
769 struct fc_seq *sp = &ep->seq;
773 FC_EXCH_DBG(ep, "Exchange timed out state %x\n", ep->state);
775 spin_lock_bh(&ep->ex_lock);
776 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
779 e_stat = ep->esb_stat;
780 if (e_stat & ESB_ST_COMPLETE) {
781 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
782 spin_unlock_bh(&ep->ex_lock);
783 if (e_stat & ESB_ST_REC_QUAL)
787 if (e_stat & ESB_ST_ABNORMAL)
788 rc = fc_exch_done_locked(ep);
789 spin_unlock_bh(&ep->ex_lock);
792 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_TIMEOUT));
793 fc_seq_set_resp(sp, NULL, ep->arg);
794 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
798 spin_unlock_bh(&ep->ex_lock);
801 * This release matches the hold taken when the timer was set.
807 * fc_exch_em_alloc() - Allocate an exchange from a specified EM.
808 * @lport: The local port that the exchange is for
809 * @mp: The exchange manager that will allocate the exchange
811 * Returns pointer to allocated fc_exch with exch lock held.
813 static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
814 struct fc_exch_mgr *mp)
819 struct fc_exch_pool *pool;
821 /* allocate memory for exchange */
822 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);
824 atomic_inc(&mp->stats.no_free_exch);
827 memset(ep, 0, sizeof(*ep));
830 pool = per_cpu_ptr(mp->pool, cpu);
831 spin_lock_bh(&pool->lock);
834 /* peek cache of free slot */
835 if (pool->left != FC_XID_UNKNOWN) {
836 if (!WARN_ON(fc_exch_ptr_get(pool, pool->left))) {
838 pool->left = FC_XID_UNKNOWN;
842 if (pool->right != FC_XID_UNKNOWN) {
843 if (!WARN_ON(fc_exch_ptr_get(pool, pool->right))) {
845 pool->right = FC_XID_UNKNOWN;
850 index = pool->next_index;
851 /* allocate new exch from pool */
852 while (fc_exch_ptr_get(pool, index)) {
853 index = index == mp->pool_max_index ? 0 : index + 1;
854 if (index == pool->next_index)
857 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
859 fc_exch_hold(ep); /* hold for exch in mp */
860 spin_lock_init(&ep->ex_lock);
862 * Hold exch lock for caller to prevent fc_exch_reset()
863 * from releasing exch while fc_exch_alloc() caller is
864 * still working on exch.
866 spin_lock_bh(&ep->ex_lock);
868 fc_exch_ptr_set(pool, index, ep);
869 list_add_tail(&ep->ex_list, &pool->ex_list);
870 fc_seq_alloc(ep, ep->seq_id++);
871 pool->total_exches++;
872 spin_unlock_bh(&pool->lock);
877 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
881 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
882 ep->rxid = FC_XID_UNKNOWN;
883 ep->class = mp->class;
885 init_waitqueue_head(&ep->resp_wq);
886 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
890 spin_unlock_bh(&pool->lock);
891 atomic_inc(&mp->stats.no_free_exch_xid);
892 mempool_free(ep, mp->ep_pool);
897 * fc_exch_alloc() - Allocate an exchange from an EM on a
898 * local port's list of EMs.
899 * @lport: The local port that will own the exchange
900 * @fp: The FC frame that the exchange will be for
902 * This function walks the list of exchange manager(EM)
903 * anchors to select an EM for a new exchange allocation. The
904 * EM is selected when a NULL match function pointer is encountered
905 * or when a call to a match function returns true.
907 static struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
910 struct fc_exch_mgr_anchor *ema;
913 list_for_each_entry(ema, &lport->ema_list, ema_list) {
914 if (!ema->match || ema->match(fp)) {
915 ep = fc_exch_em_alloc(lport, ema->mp);
924 * fc_exch_find() - Lookup and hold an exchange
925 * @mp: The exchange manager to lookup the exchange from
926 * @xid: The XID of the exchange to look up
928 static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
930 struct fc_lport *lport = mp->lport;
931 struct fc_exch_pool *pool;
932 struct fc_exch *ep = NULL;
933 u16 cpu = xid & fc_cpu_mask;
935 if (xid == FC_XID_UNKNOWN)
938 if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
939 pr_err("host%u: lport %6.6x: xid %d invalid CPU %d\n:",
940 lport->host->host_no, lport->port_id, xid, cpu);
944 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
945 pool = per_cpu_ptr(mp->pool, cpu);
946 spin_lock_bh(&pool->lock);
947 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
948 if (ep == &fc_quarantine_exch) {
949 FC_LPORT_DBG(lport, "xid %x quarantined\n", xid);
953 WARN_ON(ep->xid != xid);
956 spin_unlock_bh(&pool->lock);
963 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and
964 * the memory allocated for the related objects may be freed.
965 * @sp: The sequence that has completed
967 * Note: May sleep if invoked from outside a response handler.
969 void fc_exch_done(struct fc_seq *sp)
971 struct fc_exch *ep = fc_seq_exch(sp);
974 spin_lock_bh(&ep->ex_lock);
975 rc = fc_exch_done_locked(ep);
976 spin_unlock_bh(&ep->ex_lock);
978 fc_seq_set_resp(sp, NULL, ep->arg);
982 EXPORT_SYMBOL(fc_exch_done);
985 * fc_exch_resp() - Allocate a new exchange for a response frame
986 * @lport: The local port that the exchange was for
987 * @mp: The exchange manager to allocate the exchange from
988 * @fp: The response frame
990 * Sets the responder ID in the frame header.
992 static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
993 struct fc_exch_mgr *mp,
997 struct fc_frame_header *fh;
999 ep = fc_exch_alloc(lport, fp);
1001 ep->class = fc_frame_class(fp);
1004 * Set EX_CTX indicating we're responding on this exchange.
1006 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
1007 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
1008 fh = fc_frame_header_get(fp);
1009 ep->sid = ntoh24(fh->fh_d_id);
1010 ep->did = ntoh24(fh->fh_s_id);
1014 * Allocated exchange has placed the XID in the
1015 * originator field. Move it to the responder field,
1016 * and set the originator XID from the frame.
1019 ep->oxid = ntohs(fh->fh_ox_id);
1020 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
1021 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
1022 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
1024 fc_exch_hold(ep); /* hold for caller */
1025 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
1031 * fc_seq_lookup_recip() - Find a sequence where the other end
1032 * originated the sequence
1033 * @lport: The local port that the frame was sent to
1034 * @mp: The Exchange Manager to lookup the exchange from
1035 * @fp: The frame associated with the sequence we're looking for
1037 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
1038 * on the ep that should be released by the caller.
1040 static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
1041 struct fc_exch_mgr *mp,
1042 struct fc_frame *fp)
1044 struct fc_frame_header *fh = fc_frame_header_get(fp);
1045 struct fc_exch *ep = NULL;
1046 struct fc_seq *sp = NULL;
1047 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
1051 f_ctl = ntoh24(fh->fh_f_ctl);
1052 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
1055 * Lookup or create the exchange if we will be creating the sequence.
1057 if (f_ctl & FC_FC_EX_CTX) {
1058 xid = ntohs(fh->fh_ox_id); /* we originated exch */
1059 ep = fc_exch_find(mp, xid);
1061 atomic_inc(&mp->stats.xid_not_found);
1062 reject = FC_RJT_OX_ID;
1065 if (ep->rxid == FC_XID_UNKNOWN)
1066 ep->rxid = ntohs(fh->fh_rx_id);
1067 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
1068 reject = FC_RJT_OX_ID;
1072 xid = ntohs(fh->fh_rx_id); /* we are the responder */
1075 * Special case for MDS issuing an ELS TEST with a
1077 * XXX take this out once we do the proper reject.
1079 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
1080 fc_frame_payload_op(fp) == ELS_TEST) {
1081 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
1082 xid = FC_XID_UNKNOWN;
1086 * new sequence - find the exchange
1088 ep = fc_exch_find(mp, xid);
1089 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
1091 atomic_inc(&mp->stats.xid_busy);
1092 reject = FC_RJT_RX_ID;
1095 ep = fc_exch_resp(lport, mp, fp);
1097 reject = FC_RJT_EXCH_EST; /* XXX */
1100 xid = ep->xid; /* get our XID */
1102 atomic_inc(&mp->stats.xid_not_found);
1103 reject = FC_RJT_RX_ID; /* XID not found */
1108 spin_lock_bh(&ep->ex_lock);
1110 * At this point, we have the exchange held.
1111 * Find or create the sequence.
1113 if (fc_sof_is_init(fr_sof(fp))) {
1115 sp->ssb_stat |= SSB_ST_RESP;
1116 sp->id = fh->fh_seq_id;
1119 if (sp->id != fh->fh_seq_id) {
1120 atomic_inc(&mp->stats.seq_not_found);
1121 if (f_ctl & FC_FC_END_SEQ) {
1123 * Update sequence_id based on incoming last
1124 * frame of sequence exchange. This is needed
1125 * for FC target where DDP has been used
1126 * on target where, stack is indicated only
1127 * about last frame's (payload _header) header.
1128 * Whereas "seq_id" which is part of
1129 * frame_header is allocated by initiator
1130 * which is totally different from "seq_id"
1131 * allocated when XFER_RDY was sent by target.
1132 * To avoid false -ve which results into not
1133 * sending RSP, hence write request on other
1134 * end never finishes.
1136 sp->ssb_stat |= SSB_ST_RESP;
1137 sp->id = fh->fh_seq_id;
1139 spin_unlock_bh(&ep->ex_lock);
1141 /* sequence/exch should exist */
1142 reject = FC_RJT_SEQ_ID;
1147 WARN_ON(ep != fc_seq_exch(sp));
1149 if (f_ctl & FC_FC_SEQ_INIT)
1150 ep->esb_stat |= ESB_ST_SEQ_INIT;
1151 spin_unlock_bh(&ep->ex_lock);
1157 fc_exch_done(&ep->seq);
1158 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
1163 * fc_seq_lookup_orig() - Find a sequence where this end
1164 * originated the sequence
1165 * @mp: The Exchange Manager to lookup the exchange from
1166 * @fp: The frame associated with the sequence we're looking for
1168 * Does not hold the sequence for the caller.
1170 static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
1171 struct fc_frame *fp)
1173 struct fc_frame_header *fh = fc_frame_header_get(fp);
1175 struct fc_seq *sp = NULL;
1179 f_ctl = ntoh24(fh->fh_f_ctl);
1180 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
1181 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
1182 ep = fc_exch_find(mp, xid);
1185 if (ep->seq.id == fh->fh_seq_id) {
1187 * Save the RX_ID if we didn't previously know it.
1190 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
1191 ep->rxid == FC_XID_UNKNOWN) {
1192 ep->rxid = ntohs(fh->fh_rx_id);
1195 fc_exch_release(ep);
1200 * fc_exch_set_addr() - Set the source and destination IDs for an exchange
1201 * @ep: The exchange to set the addresses for
1202 * @orig_id: The originator's ID
1203 * @resp_id: The responder's ID
1205 * Note this must be done before the first sequence of the exchange is sent.
1207 static void fc_exch_set_addr(struct fc_exch *ep,
1208 u32 orig_id, u32 resp_id)
1211 if (ep->esb_stat & ESB_ST_RESP) {
1221 * fc_seq_els_rsp_send() - Send an ELS response using information from
1222 * the existing sequence/exchange.
1223 * @fp: The received frame
1224 * @els_cmd: The ELS command to be sent
1225 * @els_data: The ELS data to be sent
1227 * The received frame is not freed.
1229 void fc_seq_els_rsp_send(struct fc_frame *fp, enum fc_els_cmd els_cmd,
1230 struct fc_seq_els_data *els_data)
1234 fc_seq_ls_rjt(fp, els_data->reason, els_data->explan);
1240 fc_exch_els_rrq(fp);
1243 fc_exch_els_rec(fp);
1246 FC_LPORT_DBG(fr_dev(fp), "Invalid ELS CMD:%x\n", els_cmd);
1249 EXPORT_SYMBOL_GPL(fc_seq_els_rsp_send);
1252 * fc_seq_send_last() - Send a sequence that is the last in the exchange
1253 * @sp: The sequence that is to be sent
1254 * @fp: The frame that will be sent on the sequence
1255 * @rctl: The R_CTL information to be sent
1256 * @fh_type: The frame header type
1258 static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
1259 enum fc_rctl rctl, enum fc_fh_type fh_type)
1262 struct fc_exch *ep = fc_seq_exch(sp);
1264 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
1266 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
1267 fc_seq_send_locked(ep->lp, sp, fp);
1271 * fc_seq_send_ack() - Send an acknowledgement that we've received a frame
1272 * @sp: The sequence to send the ACK on
1273 * @rx_fp: The received frame that is being acknoledged
1275 * Send ACK_1 (or equiv.) indicating we received something.
1277 static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
1279 struct fc_frame *fp;
1280 struct fc_frame_header *rx_fh;
1281 struct fc_frame_header *fh;
1282 struct fc_exch *ep = fc_seq_exch(sp);
1283 struct fc_lport *lport = ep->lp;
1287 * Don't send ACKs for class 3.
1289 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
1290 fp = fc_frame_alloc(lport, 0);
1292 FC_EXCH_DBG(ep, "Drop ACK request, out of memory\n");
1296 fh = fc_frame_header_get(fp);
1297 fh->fh_r_ctl = FC_RCTL_ACK_1;
1298 fh->fh_type = FC_TYPE_BLS;
1301 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1302 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1303 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1304 * Last ACK uses bits 7-6 (continue sequence),
1305 * bits 5-4 are meaningful (what kind of ACK to use).
1307 rx_fh = fc_frame_header_get(rx_fp);
1308 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1309 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1310 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
1311 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
1312 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1313 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1314 hton24(fh->fh_f_ctl, f_ctl);
1316 fc_exch_setup_hdr(ep, fp, f_ctl);
1317 fh->fh_seq_id = rx_fh->fh_seq_id;
1318 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1319 fh->fh_parm_offset = htonl(1); /* ack single frame */
1321 fr_sof(fp) = fr_sof(rx_fp);
1322 if (f_ctl & FC_FC_END_SEQ)
1323 fr_eof(fp) = FC_EOF_T;
1325 fr_eof(fp) = FC_EOF_N;
1327 lport->tt.frame_send(lport, fp);
1332 * fc_exch_send_ba_rjt() - Send BLS Reject
1333 * @rx_fp: The frame being rejected
1334 * @reason: The reason the frame is being rejected
1335 * @explan: The explanation for the rejection
1337 * This is for rejecting BA_ABTS only.
1339 static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
1340 enum fc_ba_rjt_reason reason,
1341 enum fc_ba_rjt_explan explan)
1343 struct fc_frame *fp;
1344 struct fc_frame_header *rx_fh;
1345 struct fc_frame_header *fh;
1346 struct fc_ba_rjt *rp;
1348 struct fc_lport *lport;
1351 lport = fr_dev(rx_fp);
1353 fp = fc_frame_alloc(lport, sizeof(*rp));
1355 FC_EXCH_DBG(fc_seq_exch(sp),
1356 "Drop BA_RJT request, out of memory\n");
1359 fh = fc_frame_header_get(fp);
1360 rx_fh = fc_frame_header_get(rx_fp);
1362 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1364 rp = fc_frame_payload_get(fp, sizeof(*rp));
1365 rp->br_reason = reason;
1366 rp->br_explan = explan;
1369 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1371 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1372 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1373 fh->fh_ox_id = rx_fh->fh_ox_id;
1374 fh->fh_rx_id = rx_fh->fh_rx_id;
1375 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1376 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1377 fh->fh_type = FC_TYPE_BLS;
1380 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1381 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1382 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1383 * Last ACK uses bits 7-6 (continue sequence),
1384 * bits 5-4 are meaningful (what kind of ACK to use).
1385 * Always set LAST_SEQ, END_SEQ.
1387 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1388 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1389 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1390 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1391 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1392 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1393 f_ctl &= ~FC_FC_FIRST_SEQ;
1394 hton24(fh->fh_f_ctl, f_ctl);
1396 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1397 fr_eof(fp) = FC_EOF_T;
1398 if (fc_sof_needs_ack(fr_sof(fp)))
1399 fr_eof(fp) = FC_EOF_N;
1401 lport->tt.frame_send(lport, fp);
1405 * fc_exch_recv_abts() - Handle an incoming ABTS
1406 * @ep: The exchange the abort was on
1407 * @rx_fp: The ABTS frame
1409 * This would be for target mode usually, but could be due to lost
1410 * FCP transfer ready, confirm or RRQ. We always handle this as an
1411 * exchange abort, ignoring the parameter.
1413 static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1415 struct fc_frame *fp;
1416 struct fc_ba_acc *ap;
1417 struct fc_frame_header *fh;
1423 FC_EXCH_DBG(ep, "exch: ABTS received\n");
1424 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1426 FC_EXCH_DBG(ep, "Drop ABTS request, out of memory\n");
1430 spin_lock_bh(&ep->ex_lock);
1431 if (ep->esb_stat & ESB_ST_COMPLETE) {
1432 spin_unlock_bh(&ep->ex_lock);
1433 FC_EXCH_DBG(ep, "exch: ABTS rejected, exchange complete\n");
1437 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
1438 ep->esb_stat |= ESB_ST_REC_QUAL;
1439 fc_exch_hold(ep); /* hold for REC_QUAL */
1441 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1442 fh = fc_frame_header_get(fp);
1443 ap = fc_frame_payload_get(fp, sizeof(*ap));
1444 memset(ap, 0, sizeof(*ap));
1446 ap->ba_high_seq_cnt = htons(0xffff);
1447 if (sp->ssb_stat & SSB_ST_RESP) {
1448 ap->ba_seq_id = sp->id;
1449 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1450 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1451 ap->ba_low_seq_cnt = htons(sp->cnt);
1453 sp = fc_seq_start_next_locked(sp);
1454 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1455 ep->esb_stat |= ESB_ST_ABNORMAL;
1456 spin_unlock_bh(&ep->ex_lock);
1459 fc_frame_free(rx_fp);
1463 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1468 * fc_seq_assign() - Assign exchange and sequence for incoming request
1469 * @lport: The local port that received the request
1470 * @fp: The request frame
1472 * On success, the sequence pointer will be returned and also in fr_seq(@fp).
1473 * A reference will be held on the exchange/sequence for the caller, which
1474 * must call fc_seq_release().
1476 struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)
1478 struct fc_exch_mgr_anchor *ema;
1480 WARN_ON(lport != fr_dev(fp));
1481 WARN_ON(fr_seq(fp));
1484 list_for_each_entry(ema, &lport->ema_list, ema_list)
1485 if ((!ema->match || ema->match(fp)) &&
1486 fc_seq_lookup_recip(lport, ema->mp, fp) == FC_RJT_NONE)
1490 EXPORT_SYMBOL(fc_seq_assign);
1493 * fc_seq_release() - Release the hold
1494 * @sp: The sequence.
1496 void fc_seq_release(struct fc_seq *sp)
1498 fc_exch_release(fc_seq_exch(sp));
1500 EXPORT_SYMBOL(fc_seq_release);
1503 * fc_exch_recv_req() - Handler for an incoming request
1504 * @lport: The local port that received the request
1505 * @mp: The EM that the exchange is on
1506 * @fp: The request frame
1508 * This is used when the other end is originating the exchange
1511 static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp,
1512 struct fc_frame *fp)
1514 struct fc_frame_header *fh = fc_frame_header_get(fp);
1515 struct fc_seq *sp = NULL;
1516 struct fc_exch *ep = NULL;
1517 enum fc_pf_rjt_reason reject;
1519 /* We can have the wrong fc_lport at this point with NPIV, which is a
1520 * problem now that we know a new exchange needs to be allocated
1522 lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id));
1529 BUG_ON(fr_seq(fp)); /* XXX remove later */
1532 * If the RX_ID is 0xffff, don't allocate an exchange.
1533 * The upper-level protocol may request one later, if needed.
1535 if (fh->fh_rx_id == htons(FC_XID_UNKNOWN))
1536 return fc_lport_recv(lport, fp);
1538 reject = fc_seq_lookup_recip(lport, mp, fp);
1539 if (reject == FC_RJT_NONE) {
1540 sp = fr_seq(fp); /* sequence will be held */
1541 ep = fc_seq_exch(sp);
1542 fc_seq_send_ack(sp, fp);
1543 ep->encaps = fr_encaps(fp);
1546 * Call the receive function.
1548 * The receive function may allocate a new sequence
1549 * over the old one, so we shouldn't change the
1550 * sequence after this.
1552 * The frame will be freed by the receive function.
1553 * If new exch resp handler is valid then call that
1556 if (!fc_invoke_resp(ep, sp, fp))
1557 fc_lport_recv(lport, fp);
1558 fc_exch_release(ep); /* release from lookup */
1560 FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n",
1567 * fc_exch_recv_seq_resp() - Handler for an incoming response where the other
1568 * end is the originator of the sequence that is a
1569 * response to our initial exchange
1570 * @mp: The EM that the exchange is on
1571 * @fp: The response frame
1573 static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1575 struct fc_frame_header *fh = fc_frame_header_get(fp);
1582 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1584 atomic_inc(&mp->stats.xid_not_found);
1587 if (ep->esb_stat & ESB_ST_COMPLETE) {
1588 atomic_inc(&mp->stats.xid_not_found);
1591 if (ep->rxid == FC_XID_UNKNOWN)
1592 ep->rxid = ntohs(fh->fh_rx_id);
1593 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1594 atomic_inc(&mp->stats.xid_not_found);
1597 if (ep->did != ntoh24(fh->fh_s_id) &&
1598 ep->did != FC_FID_FLOGI) {
1599 atomic_inc(&mp->stats.xid_not_found);
1604 if (fc_sof_is_init(sof)) {
1605 sp->ssb_stat |= SSB_ST_RESP;
1606 sp->id = fh->fh_seq_id;
1609 f_ctl = ntoh24(fh->fh_f_ctl);
1612 spin_lock_bh(&ep->ex_lock);
1613 if (f_ctl & FC_FC_SEQ_INIT)
1614 ep->esb_stat |= ESB_ST_SEQ_INIT;
1615 spin_unlock_bh(&ep->ex_lock);
1617 if (fc_sof_needs_ack(sof))
1618 fc_seq_send_ack(sp, fp);
1620 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1621 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1622 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1623 spin_lock_bh(&ep->ex_lock);
1624 rc = fc_exch_done_locked(ep);
1625 WARN_ON(fc_seq_exch(sp) != ep);
1626 spin_unlock_bh(&ep->ex_lock);
1630 FC_EXCH_DBG(ep, "ep is completed already,"
1631 "hence skip calling the resp\n");
1637 * Call the receive function.
1638 * The sequence is held (has a refcnt) for us,
1639 * but not for the receive function.
1641 * The receive function may allocate a new sequence
1642 * over the old one, so we shouldn't change the
1643 * sequence after this.
1645 * The frame will be freed by the receive function.
1646 * If new exch resp handler is valid then call that
1649 if (!fc_invoke_resp(ep, sp, fp))
1653 fc_exch_release(ep);
1656 fc_exch_release(ep);
1662 * fc_exch_recv_resp() - Handler for a sequence where other end is
1663 * responding to our sequence
1664 * @mp: The EM that the exchange is on
1665 * @fp: The response frame
1667 static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1671 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1674 atomic_inc(&mp->stats.xid_not_found);
1676 atomic_inc(&mp->stats.non_bls_resp);
1682 * fc_exch_abts_resp() - Handler for a response to an ABT
1683 * @ep: The exchange that the frame is on
1684 * @fp: The response frame
1686 * This response would be to an ABTS cancelling an exchange or sequence.
1687 * The response can be either BA_ACC or BA_RJT
1689 static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1691 struct fc_frame_header *fh;
1692 struct fc_ba_acc *ap;
1696 int rc = 1, has_rec = 0;
1698 fh = fc_frame_header_get(fp);
1699 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1700 fc_exch_rctl_name(fh->fh_r_ctl));
1702 if (cancel_delayed_work_sync(&ep->timeout_work)) {
1703 FC_EXCH_DBG(ep, "Exchange timer canceled due to ABTS response\n");
1704 fc_exch_release(ep); /* release from pending timer hold */
1708 spin_lock_bh(&ep->ex_lock);
1709 switch (fh->fh_r_ctl) {
1710 case FC_RCTL_BA_ACC:
1711 ap = fc_frame_payload_get(fp, sizeof(*ap));
1716 * Decide whether to establish a Recovery Qualifier.
1717 * We do this if there is a non-empty SEQ_CNT range and
1718 * SEQ_ID is the same as the one we aborted.
1720 low = ntohs(ap->ba_low_seq_cnt);
1721 high = ntohs(ap->ba_high_seq_cnt);
1722 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1723 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1724 ap->ba_seq_id == ep->seq_id) && low != high) {
1725 ep->esb_stat |= ESB_ST_REC_QUAL;
1726 fc_exch_hold(ep); /* hold for recovery qualifier */
1730 case FC_RCTL_BA_RJT:
1736 /* do we need to do some other checks here. Can we reuse more of
1737 * fc_exch_recv_seq_resp
1741 * do we want to check END_SEQ as well as LAST_SEQ here?
1743 if (ep->fh_type != FC_TYPE_FCP &&
1744 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1745 rc = fc_exch_done_locked(ep);
1746 spin_unlock_bh(&ep->ex_lock);
1751 if (!fc_invoke_resp(ep, sp, fp))
1754 fc_exch_timer_set(ep, ep->r_a_tov);
1755 fc_exch_release(ep);
1759 * fc_exch_recv_bls() - Handler for a BLS sequence
1760 * @mp: The EM that the exchange is on
1761 * @fp: The request frame
1763 * The BLS frame is always a sequence initiated by the remote side.
1764 * We may be either the originator or recipient of the exchange.
1766 static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1768 struct fc_frame_header *fh;
1772 fh = fc_frame_header_get(fp);
1773 f_ctl = ntoh24(fh->fh_f_ctl);
1776 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1777 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1778 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1779 spin_lock_bh(&ep->ex_lock);
1780 ep->esb_stat |= ESB_ST_SEQ_INIT;
1781 spin_unlock_bh(&ep->ex_lock);
1783 if (f_ctl & FC_FC_SEQ_CTX) {
1785 * A response to a sequence we initiated.
1786 * This should only be ACKs for class 2 or F.
1788 switch (fh->fh_r_ctl) {
1794 FC_EXCH_DBG(ep, "BLS rctl %x - %s received\n",
1796 fc_exch_rctl_name(fh->fh_r_ctl));
1801 switch (fh->fh_r_ctl) {
1802 case FC_RCTL_BA_RJT:
1803 case FC_RCTL_BA_ACC:
1805 fc_exch_abts_resp(ep, fp);
1809 case FC_RCTL_BA_ABTS:
1811 fc_exch_recv_abts(ep, fp);
1815 default: /* ignore junk */
1821 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1825 * fc_seq_ls_acc() - Accept sequence with LS_ACC
1826 * @rx_fp: The received frame, not freed here.
1828 * If this fails due to allocation or transmit congestion, assume the
1829 * originator will repeat the sequence.
1831 static void fc_seq_ls_acc(struct fc_frame *rx_fp)
1833 struct fc_lport *lport;
1834 struct fc_els_ls_acc *acc;
1835 struct fc_frame *fp;
1838 lport = fr_dev(rx_fp);
1840 fp = fc_frame_alloc(lport, sizeof(*acc));
1842 FC_EXCH_DBG(fc_seq_exch(sp),
1843 "exch: drop LS_ACC, out of memory\n");
1846 acc = fc_frame_payload_get(fp, sizeof(*acc));
1847 memset(acc, 0, sizeof(*acc));
1848 acc->la_cmd = ELS_LS_ACC;
1849 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1850 lport->tt.frame_send(lport, fp);
1854 * fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT
1855 * @rx_fp: The received frame, not freed here.
1856 * @reason: The reason the sequence is being rejected
1857 * @explan: The explanation for the rejection
1859 * If this fails due to allocation or transmit congestion, assume the
1860 * originator will repeat the sequence.
1862 static void fc_seq_ls_rjt(struct fc_frame *rx_fp, enum fc_els_rjt_reason reason,
1863 enum fc_els_rjt_explan explan)
1865 struct fc_lport *lport;
1866 struct fc_els_ls_rjt *rjt;
1867 struct fc_frame *fp;
1870 lport = fr_dev(rx_fp);
1872 fp = fc_frame_alloc(lport, sizeof(*rjt));
1874 FC_EXCH_DBG(fc_seq_exch(sp),
1875 "exch: drop LS_ACC, out of memory\n");
1878 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1879 memset(rjt, 0, sizeof(*rjt));
1880 rjt->er_cmd = ELS_LS_RJT;
1881 rjt->er_reason = reason;
1882 rjt->er_explan = explan;
1883 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1884 lport->tt.frame_send(lport, fp);
1888 * fc_exch_reset() - Reset an exchange
1889 * @ep: The exchange to be reset
1891 * Note: May sleep if invoked from outside a response handler.
1893 static void fc_exch_reset(struct fc_exch *ep)
1898 spin_lock_bh(&ep->ex_lock);
1899 ep->state |= FC_EX_RST_CLEANUP;
1900 fc_exch_timer_cancel(ep);
1901 if (ep->esb_stat & ESB_ST_REC_QUAL)
1902 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1903 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1905 rc = fc_exch_done_locked(ep);
1906 spin_unlock_bh(&ep->ex_lock);
1913 FC_EXCH_DBG(ep, "ep is completed already,"
1914 "hence skip calling the resp\n");
1918 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_CLOSED));
1920 fc_seq_set_resp(sp, NULL, ep->arg);
1921 fc_exch_release(ep);
1925 * fc_exch_pool_reset() - Reset a per cpu exchange pool
1926 * @lport: The local port that the exchange pool is on
1927 * @pool: The exchange pool to be reset
1928 * @sid: The source ID
1929 * @did: The destination ID
1931 * Resets a per cpu exches pool, releasing all of its sequences
1932 * and exchanges. If sid is non-zero then reset only exchanges
1933 * we sourced from the local port's FID. If did is non-zero then
1934 * only reset exchanges destined for the local port's FID.
1936 static void fc_exch_pool_reset(struct fc_lport *lport,
1937 struct fc_exch_pool *pool,
1941 struct fc_exch *next;
1943 spin_lock_bh(&pool->lock);
1945 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1946 if ((lport == ep->lp) &&
1947 (sid == 0 || sid == ep->sid) &&
1948 (did == 0 || did == ep->did)) {
1950 spin_unlock_bh(&pool->lock);
1954 fc_exch_release(ep);
1955 spin_lock_bh(&pool->lock);
1958 * must restart loop incase while lock
1959 * was down multiple eps were released.
1964 pool->next_index = 0;
1965 pool->left = FC_XID_UNKNOWN;
1966 pool->right = FC_XID_UNKNOWN;
1967 spin_unlock_bh(&pool->lock);
1971 * fc_exch_mgr_reset() - Reset all EMs of a local port
1972 * @lport: The local port whose EMs are to be reset
1973 * @sid: The source ID
1974 * @did: The destination ID
1976 * Reset all EMs associated with a given local port. Release all
1977 * sequences and exchanges. If sid is non-zero then reset only the
1978 * exchanges sent from the local port's FID. If did is non-zero then
1979 * reset only exchanges destined for the local port's FID.
1981 void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1983 struct fc_exch_mgr_anchor *ema;
1986 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1987 for_each_possible_cpu(cpu)
1988 fc_exch_pool_reset(lport,
1989 per_cpu_ptr(ema->mp->pool, cpu),
1993 EXPORT_SYMBOL(fc_exch_mgr_reset);
1996 * fc_exch_lookup() - find an exchange
1997 * @lport: The local port
1998 * @xid: The exchange ID
2000 * Returns exchange pointer with hold for caller, or NULL if not found.
2002 static struct fc_exch *fc_exch_lookup(struct fc_lport *lport, u32 xid)
2004 struct fc_exch_mgr_anchor *ema;
2006 list_for_each_entry(ema, &lport->ema_list, ema_list)
2007 if (ema->mp->min_xid <= xid && xid <= ema->mp->max_xid)
2008 return fc_exch_find(ema->mp, xid);
2013 * fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests
2014 * @rfp: The REC frame, not freed here.
2016 * Note that the requesting port may be different than the S_ID in the request.
2018 static void fc_exch_els_rec(struct fc_frame *rfp)
2020 struct fc_lport *lport;
2021 struct fc_frame *fp;
2023 struct fc_els_rec *rp;
2024 struct fc_els_rec_acc *acc;
2025 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
2026 enum fc_els_rjt_explan explan;
2028 u16 xid, rxid, oxid;
2030 lport = fr_dev(rfp);
2031 rp = fc_frame_payload_get(rfp, sizeof(*rp));
2032 explan = ELS_EXPL_INV_LEN;
2035 sid = ntoh24(rp->rec_s_id);
2036 rxid = ntohs(rp->rec_rx_id);
2037 oxid = ntohs(rp->rec_ox_id);
2039 explan = ELS_EXPL_OXID_RXID;
2040 if (sid == fc_host_port_id(lport->host))
2044 if (xid == FC_XID_UNKNOWN) {
2046 "REC request from %x: invalid rxid %x oxid %x\n",
2050 ep = fc_exch_lookup(lport, xid);
2053 "REC request from %x: rxid %x oxid %x not found\n",
2057 FC_EXCH_DBG(ep, "REC request from %x: rxid %x oxid %x\n",
2059 if (ep->oid != sid || oxid != ep->oxid)
2061 if (rxid != FC_XID_UNKNOWN && rxid != ep->rxid)
2063 fp = fc_frame_alloc(lport, sizeof(*acc));
2065 FC_EXCH_DBG(ep, "Drop REC request, out of memory\n");
2069 acc = fc_frame_payload_get(fp, sizeof(*acc));
2070 memset(acc, 0, sizeof(*acc));
2071 acc->reca_cmd = ELS_LS_ACC;
2072 acc->reca_ox_id = rp->rec_ox_id;
2073 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
2074 acc->reca_rx_id = htons(ep->rxid);
2075 if (ep->sid == ep->oid)
2076 hton24(acc->reca_rfid, ep->did);
2078 hton24(acc->reca_rfid, ep->sid);
2079 acc->reca_fc4value = htonl(ep->seq.rec_data);
2080 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
2083 fc_fill_reply_hdr(fp, rfp, FC_RCTL_ELS_REP, 0);
2084 lport->tt.frame_send(lport, fp);
2086 fc_exch_release(ep);
2090 fc_exch_release(ep);
2092 fc_seq_ls_rjt(rfp, reason, explan);
2096 * fc_exch_rrq_resp() - Handler for RRQ responses
2097 * @sp: The sequence that the RRQ is on
2098 * @fp: The RRQ frame
2099 * @arg: The exchange that the RRQ is on
2101 * TODO: fix error handler.
2103 static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
2105 struct fc_exch *aborted_ep = arg;
2109 int err = PTR_ERR(fp);
2111 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
2113 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
2114 "frame error %d\n", err);
2118 op = fc_frame_payload_op(fp);
2123 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ\n");
2128 FC_EXCH_DBG(aborted_ep, "unexpected response op %x for RRQ\n",
2134 fc_exch_done(&aborted_ep->seq);
2135 /* drop hold for rec qual */
2136 fc_exch_release(aborted_ep);
2141 * fc_exch_seq_send() - Send a frame using a new exchange and sequence
2142 * @lport: The local port to send the frame on
2143 * @fp: The frame to be sent
2144 * @resp: The response handler for this request
2145 * @destructor: The destructor for the exchange
2146 * @arg: The argument to be passed to the response handler
2147 * @timer_msec: The timeout period for the exchange
2149 * The exchange response handler is set in this routine to resp()
2150 * function pointer. It can be called in two scenarios: if a timeout
2151 * occurs or if a response frame is received for the exchange. The
2152 * fc_frame pointer in response handler will also indicate timeout
2153 * as error using IS_ERR related macros.
2155 * The exchange destructor handler is also set in this routine.
2156 * The destructor handler is invoked by EM layer when exchange
2157 * is about to free, this can be used by caller to free its
2158 * resources along with exchange free.
2160 * The arg is passed back to resp and destructor handler.
2162 * The timeout value (in msec) for an exchange is set if non zero
2163 * timer_msec argument is specified. The timer is canceled when
2164 * it fires or when the exchange is done. The exchange timeout handler
2165 * is registered by EM layer.
2167 * The frame pointer with some of the header's fields must be
2168 * filled before calling this routine, those fields are:
2175 * - parameter or relative offset
2177 struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
2178 struct fc_frame *fp,
2179 void (*resp)(struct fc_seq *,
2180 struct fc_frame *fp,
2182 void (*destructor)(struct fc_seq *, void *),
2183 void *arg, u32 timer_msec)
2186 struct fc_seq *sp = NULL;
2187 struct fc_frame_header *fh;
2188 struct fc_fcp_pkt *fsp = NULL;
2191 ep = fc_exch_alloc(lport, fp);
2196 ep->esb_stat |= ESB_ST_SEQ_INIT;
2197 fh = fc_frame_header_get(fp);
2198 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
2200 ep->destructor = destructor;
2202 ep->r_a_tov = lport->r_a_tov;
2206 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
2207 ep->f_ctl = ntoh24(fh->fh_f_ctl);
2208 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
2211 if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD) {
2213 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
2216 if (unlikely(lport->tt.frame_send(lport, fp)))
2220 fc_exch_timer_set_locked(ep, timer_msec);
2221 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
2223 if (ep->f_ctl & FC_FC_SEQ_INIT)
2224 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
2225 spin_unlock_bh(&ep->ex_lock);
2229 fc_fcp_ddp_done(fsp);
2230 rc = fc_exch_done_locked(ep);
2231 spin_unlock_bh(&ep->ex_lock);
2236 EXPORT_SYMBOL(fc_exch_seq_send);
2239 * fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command
2240 * @ep: The exchange to send the RRQ on
2242 * This tells the remote port to stop blocking the use of
2243 * the exchange and the seq_cnt range.
2245 static void fc_exch_rrq(struct fc_exch *ep)
2247 struct fc_lport *lport;
2248 struct fc_els_rrq *rrq;
2249 struct fc_frame *fp;
2254 fp = fc_frame_alloc(lport, sizeof(*rrq));
2258 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
2259 memset(rrq, 0, sizeof(*rrq));
2260 rrq->rrq_cmd = ELS_RRQ;
2261 hton24(rrq->rrq_s_id, ep->sid);
2262 rrq->rrq_ox_id = htons(ep->oxid);
2263 rrq->rrq_rx_id = htons(ep->rxid);
2266 if (ep->esb_stat & ESB_ST_RESP)
2269 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
2270 lport->port_id, FC_TYPE_ELS,
2271 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
2273 if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep,
2278 FC_EXCH_DBG(ep, "exch: RRQ send failed\n");
2279 spin_lock_bh(&ep->ex_lock);
2280 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
2281 spin_unlock_bh(&ep->ex_lock);
2282 /* drop hold for rec qual */
2283 fc_exch_release(ep);
2286 ep->esb_stat |= ESB_ST_REC_QUAL;
2287 fc_exch_timer_set_locked(ep, ep->r_a_tov);
2288 spin_unlock_bh(&ep->ex_lock);
2292 * fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests
2293 * @fp: The RRQ frame, not freed here.
2295 static void fc_exch_els_rrq(struct fc_frame *fp)
2297 struct fc_lport *lport;
2298 struct fc_exch *ep = NULL; /* request or subject exchange */
2299 struct fc_els_rrq *rp;
2302 enum fc_els_rjt_explan explan;
2305 rp = fc_frame_payload_get(fp, sizeof(*rp));
2306 explan = ELS_EXPL_INV_LEN;
2311 * lookup subject exchange.
2313 sid = ntoh24(rp->rrq_s_id); /* subject source */
2314 xid = fc_host_port_id(lport->host) == sid ?
2315 ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
2316 ep = fc_exch_lookup(lport, xid);
2317 explan = ELS_EXPL_OXID_RXID;
2320 spin_lock_bh(&ep->ex_lock);
2321 FC_EXCH_DBG(ep, "RRQ request from %x: xid %x rxid %x oxid %x\n",
2322 sid, xid, ntohs(rp->rrq_rx_id), ntohs(rp->rrq_ox_id));
2323 if (ep->oxid != ntohs(rp->rrq_ox_id))
2325 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
2326 ep->rxid != FC_XID_UNKNOWN)
2328 explan = ELS_EXPL_SID;
2333 * Clear Recovery Qualifier state, and cancel timer if complete.
2335 if (ep->esb_stat & ESB_ST_REC_QUAL) {
2336 ep->esb_stat &= ~ESB_ST_REC_QUAL;
2337 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
2339 if (ep->esb_stat & ESB_ST_COMPLETE)
2340 fc_exch_timer_cancel(ep);
2342 spin_unlock_bh(&ep->ex_lock);
2351 spin_unlock_bh(&ep->ex_lock);
2353 fc_seq_ls_rjt(fp, ELS_RJT_LOGIC, explan);
2356 fc_exch_release(ep); /* drop hold from fc_exch_find */
2360 * fc_exch_update_stats() - update exches stats to lport
2361 * @lport: The local port to update exchange manager stats
2363 void fc_exch_update_stats(struct fc_lport *lport)
2365 struct fc_host_statistics *st;
2366 struct fc_exch_mgr_anchor *ema;
2367 struct fc_exch_mgr *mp;
2369 st = &lport->host_stats;
2371 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2373 st->fc_no_free_exch += atomic_read(&mp->stats.no_free_exch);
2374 st->fc_no_free_exch_xid +=
2375 atomic_read(&mp->stats.no_free_exch_xid);
2376 st->fc_xid_not_found += atomic_read(&mp->stats.xid_not_found);
2377 st->fc_xid_busy += atomic_read(&mp->stats.xid_busy);
2378 st->fc_seq_not_found += atomic_read(&mp->stats.seq_not_found);
2379 st->fc_non_bls_resp += atomic_read(&mp->stats.non_bls_resp);
2382 EXPORT_SYMBOL(fc_exch_update_stats);
2385 * fc_exch_mgr_add() - Add an exchange manager to a local port's list of EMs
2386 * @lport: The local port to add the exchange manager to
2387 * @mp: The exchange manager to be added to the local port
2388 * @match: The match routine that indicates when this EM should be used
2390 struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
2391 struct fc_exch_mgr *mp,
2392 bool (*match)(struct fc_frame *))
2394 struct fc_exch_mgr_anchor *ema;
2396 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
2402 /* add EM anchor to EM anchors list */
2403 list_add_tail(&ema->ema_list, &lport->ema_list);
2404 kref_get(&mp->kref);
2407 EXPORT_SYMBOL(fc_exch_mgr_add);
2410 * fc_exch_mgr_destroy() - Destroy an exchange manager
2411 * @kref: The reference to the EM to be destroyed
2413 static void fc_exch_mgr_destroy(struct kref *kref)
2415 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
2417 mempool_destroy(mp->ep_pool);
2418 free_percpu(mp->pool);
2423 * fc_exch_mgr_del() - Delete an EM from a local port's list
2424 * @ema: The exchange manager anchor identifying the EM to be deleted
2426 void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
2428 /* remove EM anchor from EM anchors list */
2429 list_del(&ema->ema_list);
2430 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
2433 EXPORT_SYMBOL(fc_exch_mgr_del);
2436 * fc_exch_mgr_list_clone() - Share all exchange manager objects
2437 * @src: Source lport to clone exchange managers from
2438 * @dst: New lport that takes references to all the exchange managers
2440 int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)
2442 struct fc_exch_mgr_anchor *ema, *tmp;
2444 list_for_each_entry(ema, &src->ema_list, ema_list) {
2445 if (!fc_exch_mgr_add(dst, ema->mp, ema->match))
2450 list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)
2451 fc_exch_mgr_del(ema);
2454 EXPORT_SYMBOL(fc_exch_mgr_list_clone);
2457 * fc_exch_mgr_alloc() - Allocate an exchange manager
2458 * @lport: The local port that the new EM will be associated with
2459 * @class: The default FC class for new exchanges
2460 * @min_xid: The minimum XID for exchanges from the new EM
2461 * @max_xid: The maximum XID for exchanges from the new EM
2462 * @match: The match routine for the new EM
2464 struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport,
2465 enum fc_class class,
2466 u16 min_xid, u16 max_xid,
2467 bool (*match)(struct fc_frame *))
2469 struct fc_exch_mgr *mp;
2470 u16 pool_exch_range;
2473 struct fc_exch_pool *pool;
2475 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
2476 (min_xid & fc_cpu_mask) != 0) {
2477 FC_LPORT_DBG(lport, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
2483 * allocate memory for EM
2485 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
2491 /* adjust em exch xid range for offload */
2492 mp->min_xid = min_xid;
2494 /* reduce range so per cpu pool fits into PCPU_MIN_UNIT_SIZE pool */
2495 pool_exch_range = (PCPU_MIN_UNIT_SIZE - sizeof(*pool)) /
2496 sizeof(struct fc_exch *);
2497 if ((max_xid - min_xid + 1) / (fc_cpu_mask + 1) > pool_exch_range) {
2498 mp->max_xid = pool_exch_range * (fc_cpu_mask + 1) +
2501 mp->max_xid = max_xid;
2502 pool_exch_range = (mp->max_xid - mp->min_xid + 1) /
2506 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
2511 * Setup per cpu exch pool with entire exchange id range equally
2512 * divided across all cpus. The exch pointers array memory is
2513 * allocated for exch range per pool.
2515 mp->pool_max_index = pool_exch_range - 1;
2518 * Allocate and initialize per cpu exch pool
2520 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
2521 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
2524 for_each_possible_cpu(cpu) {
2525 pool = per_cpu_ptr(mp->pool, cpu);
2526 pool->next_index = 0;
2527 pool->left = FC_XID_UNKNOWN;
2528 pool->right = FC_XID_UNKNOWN;
2529 spin_lock_init(&pool->lock);
2530 INIT_LIST_HEAD(&pool->ex_list);
2533 kref_init(&mp->kref);
2534 if (!fc_exch_mgr_add(lport, mp, match)) {
2535 free_percpu(mp->pool);
2540 * Above kref_init() sets mp->kref to 1 and then
2541 * call to fc_exch_mgr_add incremented mp->kref again,
2542 * so adjust that extra increment.
2544 kref_put(&mp->kref, fc_exch_mgr_destroy);
2548 mempool_destroy(mp->ep_pool);
2553 EXPORT_SYMBOL(fc_exch_mgr_alloc);
2556 * fc_exch_mgr_free() - Free all exchange managers on a local port
2557 * @lport: The local port whose EMs are to be freed
2559 void fc_exch_mgr_free(struct fc_lport *lport)
2561 struct fc_exch_mgr_anchor *ema, *next;
2563 flush_workqueue(fc_exch_workqueue);
2564 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
2565 fc_exch_mgr_del(ema);
2567 EXPORT_SYMBOL(fc_exch_mgr_free);
2570 * fc_find_ema() - Lookup and return appropriate Exchange Manager Anchor depending
2573 * @lport: The local port the frame was received on
2574 * @fh: The received frame header
2576 static struct fc_exch_mgr_anchor *fc_find_ema(u32 f_ctl,
2577 struct fc_lport *lport,
2578 struct fc_frame_header *fh)
2580 struct fc_exch_mgr_anchor *ema;
2583 if (f_ctl & FC_FC_EX_CTX)
2584 xid = ntohs(fh->fh_ox_id);
2586 xid = ntohs(fh->fh_rx_id);
2587 if (xid == FC_XID_UNKNOWN)
2588 return list_entry(lport->ema_list.prev,
2589 typeof(*ema), ema_list);
2592 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2593 if ((xid >= ema->mp->min_xid) &&
2594 (xid <= ema->mp->max_xid))
2600 * fc_exch_recv() - Handler for received frames
2601 * @lport: The local port the frame was received on
2602 * @fp: The received frame
2604 void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)
2606 struct fc_frame_header *fh = fc_frame_header_get(fp);
2607 struct fc_exch_mgr_anchor *ema;
2611 if (!lport || lport->state == LPORT_ST_DISABLED) {
2612 FC_LIBFC_DBG("Receiving frames for an lport that "
2613 "has not been initialized correctly\n");
2618 f_ctl = ntoh24(fh->fh_f_ctl);
2619 ema = fc_find_ema(f_ctl, lport, fh);
2621 FC_LPORT_DBG(lport, "Unable to find Exchange Manager Anchor,"
2622 "fc_ctl <0x%x>, xid <0x%x>\n",
2624 (f_ctl & FC_FC_EX_CTX) ?
2625 ntohs(fh->fh_ox_id) :
2626 ntohs(fh->fh_rx_id));
2632 * If frame is marked invalid, just drop it.
2634 switch (fr_eof(fp)) {
2636 if (f_ctl & FC_FC_END_SEQ)
2637 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2640 if (fh->fh_type == FC_TYPE_BLS)
2641 fc_exch_recv_bls(ema->mp, fp);
2642 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2644 fc_exch_recv_seq_resp(ema->mp, fp);
2645 else if (f_ctl & FC_FC_SEQ_CTX)
2646 fc_exch_recv_resp(ema->mp, fp);
2647 else /* no EX_CTX and no SEQ_CTX */
2648 fc_exch_recv_req(lport, ema->mp, fp);
2651 FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)",
2656 EXPORT_SYMBOL(fc_exch_recv);
2659 * fc_exch_init() - Initialize the exchange layer for a local port
2660 * @lport: The local port to initialize the exchange layer for
2662 int fc_exch_init(struct fc_lport *lport)
2664 if (!lport->tt.exch_mgr_reset)
2665 lport->tt.exch_mgr_reset = fc_exch_mgr_reset;
2669 EXPORT_SYMBOL(fc_exch_init);
2672 * fc_setup_exch_mgr() - Setup an exchange manager
2674 int fc_setup_exch_mgr(void)
2676 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2677 0, SLAB_HWCACHE_ALIGN, NULL);
2682 * Initialize fc_cpu_mask and fc_cpu_order. The
2683 * fc_cpu_mask is set for nr_cpu_ids rounded up
2684 * to order of 2's * power and order is stored
2685 * in fc_cpu_order as this is later required in
2686 * mapping between an exch id and exch array index
2687 * in per cpu exch pool.
2689 * This round up is required to align fc_cpu_mask
2690 * to exchange id's lower bits such that all incoming
2691 * frames of an exchange gets delivered to the same
2692 * cpu on which exchange originated by simple bitwise
2693 * AND operation between fc_cpu_mask and exchange id.
2695 fc_cpu_order = ilog2(roundup_pow_of_two(nr_cpu_ids));
2696 fc_cpu_mask = (1 << fc_cpu_order) - 1;
2698 fc_exch_workqueue = create_singlethread_workqueue("fc_exch_workqueue");
2699 if (!fc_exch_workqueue)
2703 kmem_cache_destroy(fc_em_cachep);
2708 * fc_destroy_exch_mgr() - Destroy an exchange manager
2710 void fc_destroy_exch_mgr(void)
2712 destroy_workqueue(fc_exch_workqueue);
2713 kmem_cache_destroy(fc_em_cachep);