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;
97 struct fc_lport *lport;
105 atomic_t no_free_exch;
106 atomic_t no_free_exch_xid;
107 atomic_t xid_not_found;
109 atomic_t seq_not_found;
110 atomic_t non_bls_resp;
115 * struct fc_exch_mgr_anchor - primary structure for list of EMs
116 * @ema_list: Exchange Manager Anchor list
117 * @mp: Exchange Manager associated with this anchor
118 * @match: Routine to determine if this anchor's EM should be used
120 * When walking the list of anchors the match routine will be called
121 * for each anchor to determine if that EM should be used. The last
122 * anchor in the list will always match to handle any exchanges not
123 * handled by other EMs. The non-default EMs would be added to the
124 * anchor list by HW that provides offloads.
126 struct fc_exch_mgr_anchor {
127 struct list_head ema_list;
128 struct fc_exch_mgr *mp;
129 bool (*match)(struct fc_frame *);
132 static void fc_exch_rrq(struct fc_exch *);
133 static void fc_seq_ls_acc(struct fc_frame *);
134 static void fc_seq_ls_rjt(struct fc_frame *, enum fc_els_rjt_reason,
135 enum fc_els_rjt_explan);
136 static void fc_exch_els_rec(struct fc_frame *);
137 static void fc_exch_els_rrq(struct fc_frame *);
140 * Internal implementation notes.
142 * The exchange manager is one by default in libfc but LLD may choose
143 * to have one per CPU. The sequence manager is one per exchange manager
144 * and currently never separated.
146 * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field
147 * assigned by the Sequence Initiator that shall be unique for a specific
148 * D_ID and S_ID pair while the Sequence is open." Note that it isn't
149 * qualified by exchange ID, which one might think it would be.
150 * In practice this limits the number of open sequences and exchanges to 256
151 * per session. For most targets we could treat this limit as per exchange.
153 * The exchange and its sequence are freed when the last sequence is received.
154 * It's possible for the remote port to leave an exchange open without
155 * sending any sequences.
157 * Notes on reference counts:
159 * Exchanges are reference counted and exchange gets freed when the reference
160 * count becomes zero.
163 * Sequences are timed out for E_D_TOV and R_A_TOV.
165 * Sequence event handling:
167 * The following events may occur on initiator sequences:
170 * For now, the whole thing is sent.
172 * This applies only to class F.
173 * The sequence is marked complete.
175 * The upper layer calls fc_exch_done() when done
176 * with exchange and sequence tuple.
177 * RX-inferred completion.
178 * When we receive the next sequence on the same exchange, we can
179 * retire the previous sequence ID. (XXX not implemented).
181 * R_A_TOV frees the sequence ID. If we're waiting for ACK,
182 * E_D_TOV causes abort and calls upper layer response handler
183 * with FC_EX_TIMEOUT error.
189 * The following events may occur on recipient sequences:
192 * Allocate sequence for first frame received.
193 * Hold during receive handler.
194 * Release when final frame received.
195 * Keep status of last N of these for the ELS RES command. XXX TBD.
197 * Deallocate sequence
201 * For now, we neglect conditions where only part of a sequence was
202 * received or transmitted, or where out-of-order receipt is detected.
208 * The EM code run in a per-CPU worker thread.
210 * To protect against concurrency between a worker thread code and timers,
211 * sequence allocation and deallocation must be locked.
212 * - exchange refcnt can be done atomicly without locks.
213 * - sequence allocation must be locked by exch lock.
214 * - If the EM pool lock and ex_lock must be taken at the same time, then the
215 * EM pool lock must be taken before the ex_lock.
219 * opcode names for debugging.
221 static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;
224 * fc_exch_name_lookup() - Lookup name by opcode
225 * @op: Opcode to be looked up
226 * @table: Opcode/name table
227 * @max_index: Index not to be exceeded
229 * This routine is used to determine a human-readable string identifying
232 static inline const char *fc_exch_name_lookup(unsigned int op, char **table,
233 unsigned int max_index)
235 const char *name = NULL;
245 * fc_exch_rctl_name() - Wrapper routine for fc_exch_name_lookup()
246 * @op: The opcode to be looked up
248 static const char *fc_exch_rctl_name(unsigned int op)
250 return fc_exch_name_lookup(op, fc_exch_rctl_names,
251 ARRAY_SIZE(fc_exch_rctl_names));
255 * fc_exch_hold() - Increment an exchange's reference count
256 * @ep: Echange to be held
258 static inline void fc_exch_hold(struct fc_exch *ep)
260 atomic_inc(&ep->ex_refcnt);
264 * fc_exch_setup_hdr() - Initialize a FC header by initializing some fields
265 * and determine SOF and EOF.
266 * @ep: The exchange to that will use the header
267 * @fp: The frame whose header is to be modified
268 * @f_ctl: F_CTL bits that will be used for the frame header
270 * The fields initialized by this routine are: fh_ox_id, fh_rx_id,
271 * fh_seq_id, fh_seq_cnt and the SOF and EOF.
273 static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,
276 struct fc_frame_header *fh = fc_frame_header_get(fp);
279 fr_sof(fp) = ep->class;
281 fr_sof(fp) = fc_sof_normal(ep->class);
283 if (f_ctl & FC_FC_END_SEQ) {
284 fr_eof(fp) = FC_EOF_T;
285 if (fc_sof_needs_ack(ep->class))
286 fr_eof(fp) = FC_EOF_N;
289 * The number of fill bytes to make the length a 4-byte
290 * multiple is the low order 2-bits of the f_ctl.
291 * The fill itself will have been cleared by the frame
293 * After this, the length will be even, as expected by
296 fill = fr_len(fp) & 3;
299 /* TODO, this may be a problem with fragmented skb */
300 skb_put(fp_skb(fp), fill);
301 hton24(fh->fh_f_ctl, f_ctl | fill);
304 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
305 fr_eof(fp) = FC_EOF_N;
308 /* Initialize remaining fh fields from fc_fill_fc_hdr */
309 fh->fh_ox_id = htons(ep->oxid);
310 fh->fh_rx_id = htons(ep->rxid);
311 fh->fh_seq_id = ep->seq.id;
312 fh->fh_seq_cnt = htons(ep->seq.cnt);
316 * fc_exch_release() - Decrement an exchange's reference count
317 * @ep: Exchange to be released
319 * If the reference count reaches zero and the exchange is complete,
322 static void fc_exch_release(struct fc_exch *ep)
324 struct fc_exch_mgr *mp;
326 if (atomic_dec_and_test(&ep->ex_refcnt)) {
329 ep->destructor(&ep->seq, ep->arg);
330 WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));
331 mempool_free(ep, mp->ep_pool);
336 * fc_exch_timer_cancel() - cancel exch timer
337 * @ep: The exchange whose timer to be canceled
339 static inline void fc_exch_timer_cancel(struct fc_exch *ep)
341 if (cancel_delayed_work(&ep->timeout_work)) {
342 FC_EXCH_DBG(ep, "Exchange timer canceled\n");
343 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
348 * fc_exch_timer_set_locked() - Start a timer for an exchange w/ the
349 * the exchange lock held
350 * @ep: The exchange whose timer will start
351 * @timer_msec: The timeout period
353 * Used for upper level protocols to time out the exchange.
354 * The timer is cancelled when it fires or when the exchange completes.
356 static inline void fc_exch_timer_set_locked(struct fc_exch *ep,
357 unsigned int timer_msec)
359 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
362 FC_EXCH_DBG(ep, "Exchange timer armed : %d msecs\n", timer_msec);
364 fc_exch_hold(ep); /* hold for timer */
365 if (!queue_delayed_work(fc_exch_workqueue, &ep->timeout_work,
366 msecs_to_jiffies(timer_msec))) {
367 FC_EXCH_DBG(ep, "Exchange already queued\n");
373 * fc_exch_timer_set() - Lock the exchange and set the timer
374 * @ep: The exchange whose timer will start
375 * @timer_msec: The timeout period
377 static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec)
379 spin_lock_bh(&ep->ex_lock);
380 fc_exch_timer_set_locked(ep, timer_msec);
381 spin_unlock_bh(&ep->ex_lock);
385 * fc_exch_done_locked() - Complete an exchange with the exchange lock held
386 * @ep: The exchange that is complete
388 * Note: May sleep if invoked from outside a response handler.
390 static int fc_exch_done_locked(struct fc_exch *ep)
395 * We must check for completion in case there are two threads
396 * tyring to complete this. But the rrq code will reuse the
397 * ep, and in that case we only clear the resp and set it as
398 * complete, so it can be reused by the timer to send the rrq.
400 if (ep->state & FC_EX_DONE)
402 ep->esb_stat |= ESB_ST_COMPLETE;
404 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
405 ep->state |= FC_EX_DONE;
406 fc_exch_timer_cancel(ep);
412 static struct fc_exch fc_quarantine_exch;
415 * fc_exch_ptr_get() - Return an exchange from an exchange pool
416 * @pool: Exchange Pool to get an exchange from
417 * @index: Index of the exchange within the pool
419 * Use the index to get an exchange from within an exchange pool. exches
420 * will point to an array of exchange pointers. The index will select
421 * the exchange within the array.
423 static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,
426 struct fc_exch **exches = (struct fc_exch **)(pool + 1);
427 return exches[index];
431 * fc_exch_ptr_set() - Assign an exchange to a slot in an exchange pool
432 * @pool: The pool to assign the exchange to
433 * @index: The index in the pool where the exchange will be assigned
434 * @ep: The exchange to assign to the pool
436 static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
439 ((struct fc_exch **)(pool + 1))[index] = ep;
443 * fc_exch_delete() - Delete an exchange
444 * @ep: The exchange to be deleted
446 static void fc_exch_delete(struct fc_exch *ep)
448 struct fc_exch_pool *pool;
452 spin_lock_bh(&pool->lock);
453 WARN_ON(pool->total_exches <= 0);
454 pool->total_exches--;
456 /* update cache of free slot */
457 index = (ep->xid - ep->em->min_xid) >> fc_cpu_order;
458 if (!(ep->state & FC_EX_QUARANTINE)) {
459 if (pool->left == FC_XID_UNKNOWN)
461 else if (pool->right == FC_XID_UNKNOWN)
464 pool->next_index = index;
465 fc_exch_ptr_set(pool, index, NULL);
467 fc_exch_ptr_set(pool, index, &fc_quarantine_exch);
469 list_del(&ep->ex_list);
470 spin_unlock_bh(&pool->lock);
471 fc_exch_release(ep); /* drop hold for exch in mp */
474 static int fc_seq_send_locked(struct fc_lport *lport, struct fc_seq *sp,
478 struct fc_frame_header *fh = fc_frame_header_get(fp);
481 u8 fh_type = fh->fh_type;
483 ep = fc_seq_exch(sp);
485 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL)) {
490 WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT));
492 f_ctl = ntoh24(fh->fh_f_ctl);
493 fc_exch_setup_hdr(ep, fp, f_ctl);
494 fr_encaps(fp) = ep->encaps;
497 * update sequence count if this frame is carrying
498 * multiple FC frames when sequence offload is enabled
501 if (fr_max_payload(fp))
502 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),
510 error = lport->tt.frame_send(lport, fp);
512 if (fh_type == FC_TYPE_BLS)
516 * Update the exchange and sequence flags,
517 * assuming all frames for the sequence have been sent.
518 * We can only be called to send once for each sequence.
520 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
521 if (f_ctl & FC_FC_SEQ_INIT)
522 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
528 * fc_seq_send() - Send a frame using existing sequence/exchange pair
529 * @lport: The local port that the exchange will be sent on
530 * @sp: The sequence to be sent
531 * @fp: The frame to be sent on the exchange
533 * Note: The frame will be freed either by a direct call to fc_frame_free(fp)
534 * or indirectly by calling libfc_function_template.frame_send().
536 int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp, struct fc_frame *fp)
540 ep = fc_seq_exch(sp);
541 spin_lock_bh(&ep->ex_lock);
542 error = fc_seq_send_locked(lport, sp, fp);
543 spin_unlock_bh(&ep->ex_lock);
546 EXPORT_SYMBOL(fc_seq_send);
549 * fc_seq_alloc() - Allocate a sequence for a given exchange
550 * @ep: The exchange to allocate a new sequence for
551 * @seq_id: The sequence ID to be used
553 * We don't support multiple originated sequences on the same exchange.
554 * By implication, any previously originated sequence on this exchange
555 * is complete, and we reallocate the same sequence.
557 static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
569 * fc_seq_start_next_locked() - Allocate a new sequence on the same
570 * exchange as the supplied sequence
571 * @sp: The sequence/exchange to get a new sequence for
573 static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
575 struct fc_exch *ep = fc_seq_exch(sp);
577 sp = fc_seq_alloc(ep, ep->seq_id++);
578 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
584 * fc_seq_start_next() - Lock the exchange and get a new sequence
585 * for a given sequence/exchange pair
586 * @sp: The sequence/exchange to get a new exchange for
588 struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
590 struct fc_exch *ep = fc_seq_exch(sp);
592 spin_lock_bh(&ep->ex_lock);
593 sp = fc_seq_start_next_locked(sp);
594 spin_unlock_bh(&ep->ex_lock);
598 EXPORT_SYMBOL(fc_seq_start_next);
601 * Set the response handler for the exchange associated with a sequence.
603 * Note: May sleep if invoked from outside a response handler.
605 void fc_seq_set_resp(struct fc_seq *sp,
606 void (*resp)(struct fc_seq *, struct fc_frame *, void *),
609 struct fc_exch *ep = fc_seq_exch(sp);
612 spin_lock_bh(&ep->ex_lock);
613 while (ep->resp_active && ep->resp_task != current) {
614 prepare_to_wait(&ep->resp_wq, &wait, TASK_UNINTERRUPTIBLE);
615 spin_unlock_bh(&ep->ex_lock);
619 spin_lock_bh(&ep->ex_lock);
621 finish_wait(&ep->resp_wq, &wait);
624 spin_unlock_bh(&ep->ex_lock);
626 EXPORT_SYMBOL(fc_seq_set_resp);
629 * fc_exch_abort_locked() - Abort an exchange
630 * @ep: The exchange to be aborted
631 * @timer_msec: The period of time to wait before aborting
633 * Abort an exchange and sequence. Generally called because of a
634 * exchange timeout or an abort from the upper layer.
636 * A timer_msec can be specified for abort timeout, if non-zero
637 * timer_msec value is specified then exchange resp handler
638 * will be called with timeout error if no response to abort.
640 * Locking notes: Called with exch lock held
642 * Return value: 0 on success else error code
644 static int fc_exch_abort_locked(struct fc_exch *ep,
645 unsigned int timer_msec)
651 FC_EXCH_DBG(ep, "exch: abort, time %d msecs\n", timer_msec);
652 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
653 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
654 FC_EXCH_DBG(ep, "exch: already completed esb %x state %x\n",
655 ep->esb_stat, ep->state);
660 * Send the abort on a new sequence if possible.
662 sp = fc_seq_start_next_locked(&ep->seq);
667 fc_exch_timer_set_locked(ep, timer_msec);
671 * Send an abort for the sequence that timed out.
673 fp = fc_frame_alloc(ep->lp, 0);
675 ep->esb_stat |= ESB_ST_SEQ_INIT;
676 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
677 FC_TYPE_BLS, FC_FC_END_SEQ |
679 error = fc_seq_send_locked(ep->lp, sp, fp);
685 * If not logged into the fabric, don't send ABTS but leave
686 * sequence active until next timeout.
690 ep->esb_stat |= ESB_ST_ABNORMAL;
695 * fc_seq_exch_abort() - Abort an exchange and sequence
696 * @req_sp: The sequence to be aborted
697 * @timer_msec: The period of time to wait before aborting
699 * Generally called because of a timeout or an abort from the upper layer.
701 * Return value: 0 on success else error code
703 int fc_seq_exch_abort(const struct fc_seq *req_sp, unsigned int timer_msec)
708 ep = fc_seq_exch(req_sp);
709 spin_lock_bh(&ep->ex_lock);
710 error = fc_exch_abort_locked(ep, timer_msec);
711 spin_unlock_bh(&ep->ex_lock);
716 * fc_invoke_resp() - invoke ep->resp()
719 * It is assumed that after initialization finished (this means the
720 * first unlock of ex_lock after fc_exch_alloc()) ep->resp and ep->arg are
721 * modified only via fc_seq_set_resp(). This guarantees that none of these
722 * two variables changes if ep->resp_active > 0.
724 * If an fc_seq_set_resp() call is busy modifying ep->resp and ep->arg when
725 * this function is invoked, the first spin_lock_bh() call in this function
726 * will wait until fc_seq_set_resp() has finished modifying these variables.
728 * Since fc_exch_done() invokes fc_seq_set_resp() it is guaranteed that that
729 * ep->resp() won't be invoked after fc_exch_done() has returned.
731 * The response handler itself may invoke fc_exch_done(), which will clear the
735 * Returns true if and only if ep->resp has been invoked.
737 static bool fc_invoke_resp(struct fc_exch *ep, struct fc_seq *sp,
740 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
744 spin_lock_bh(&ep->ex_lock);
746 if (ep->resp_task != current)
747 ep->resp_task = !ep->resp_task ? current : NULL;
750 spin_unlock_bh(&ep->ex_lock);
757 spin_lock_bh(&ep->ex_lock);
758 if (--ep->resp_active == 0)
759 ep->resp_task = NULL;
760 spin_unlock_bh(&ep->ex_lock);
762 if (ep->resp_active == 0)
763 wake_up(&ep->resp_wq);
769 * fc_exch_timeout() - Handle exchange timer expiration
770 * @work: The work_struct identifying the exchange that timed out
772 static void fc_exch_timeout(struct work_struct *work)
774 struct fc_exch *ep = container_of(work, struct fc_exch,
776 struct fc_seq *sp = &ep->seq;
780 FC_EXCH_DBG(ep, "Exchange timed out state %x\n", ep->state);
782 spin_lock_bh(&ep->ex_lock);
783 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
786 e_stat = ep->esb_stat;
787 if (e_stat & ESB_ST_COMPLETE) {
788 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
789 spin_unlock_bh(&ep->ex_lock);
790 if (e_stat & ESB_ST_REC_QUAL)
794 if (e_stat & ESB_ST_ABNORMAL)
795 rc = fc_exch_done_locked(ep);
796 spin_unlock_bh(&ep->ex_lock);
799 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_TIMEOUT));
800 fc_seq_set_resp(sp, NULL, ep->arg);
801 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
805 spin_unlock_bh(&ep->ex_lock);
808 * This release matches the hold taken when the timer was set.
814 * fc_exch_em_alloc() - Allocate an exchange from a specified EM.
815 * @lport: The local port that the exchange is for
816 * @mp: The exchange manager that will allocate the exchange
818 * Returns pointer to allocated fc_exch with exch lock held.
820 static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
821 struct fc_exch_mgr *mp)
826 struct fc_exch_pool *pool;
828 /* allocate memory for exchange */
829 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);
831 atomic_inc(&mp->stats.no_free_exch);
834 memset(ep, 0, sizeof(*ep));
837 pool = per_cpu_ptr(mp->pool, cpu);
838 spin_lock_bh(&pool->lock);
841 /* peek cache of free slot */
842 if (pool->left != FC_XID_UNKNOWN) {
843 if (!WARN_ON(fc_exch_ptr_get(pool, pool->left))) {
845 pool->left = FC_XID_UNKNOWN;
849 if (pool->right != FC_XID_UNKNOWN) {
850 if (!WARN_ON(fc_exch_ptr_get(pool, pool->right))) {
852 pool->right = FC_XID_UNKNOWN;
857 index = pool->next_index;
858 /* allocate new exch from pool */
859 while (fc_exch_ptr_get(pool, index)) {
860 index = index == mp->pool_max_index ? 0 : index + 1;
861 if (index == pool->next_index)
864 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
866 fc_exch_hold(ep); /* hold for exch in mp */
867 spin_lock_init(&ep->ex_lock);
869 * Hold exch lock for caller to prevent fc_exch_reset()
870 * from releasing exch while fc_exch_alloc() caller is
871 * still working on exch.
873 spin_lock_bh(&ep->ex_lock);
875 fc_exch_ptr_set(pool, index, ep);
876 list_add_tail(&ep->ex_list, &pool->ex_list);
877 fc_seq_alloc(ep, ep->seq_id++);
878 pool->total_exches++;
879 spin_unlock_bh(&pool->lock);
884 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
888 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
889 ep->rxid = FC_XID_UNKNOWN;
890 ep->class = mp->class;
892 init_waitqueue_head(&ep->resp_wq);
893 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
897 spin_unlock_bh(&pool->lock);
898 atomic_inc(&mp->stats.no_free_exch_xid);
899 mempool_free(ep, mp->ep_pool);
904 * fc_exch_alloc() - Allocate an exchange from an EM on a
905 * local port's list of EMs.
906 * @lport: The local port that will own the exchange
907 * @fp: The FC frame that the exchange will be for
909 * This function walks the list of exchange manager(EM)
910 * anchors to select an EM for a new exchange allocation. The
911 * EM is selected when a NULL match function pointer is encountered
912 * or when a call to a match function returns true.
914 static struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
917 struct fc_exch_mgr_anchor *ema;
920 list_for_each_entry(ema, &lport->ema_list, ema_list) {
921 if (!ema->match || ema->match(fp)) {
922 ep = fc_exch_em_alloc(lport, ema->mp);
931 * fc_exch_find() - Lookup and hold an exchange
932 * @mp: The exchange manager to lookup the exchange from
933 * @xid: The XID of the exchange to look up
935 static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
937 struct fc_lport *lport = mp->lport;
938 struct fc_exch_pool *pool;
939 struct fc_exch *ep = NULL;
940 u16 cpu = xid & fc_cpu_mask;
942 if (xid == FC_XID_UNKNOWN)
945 if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
946 pr_err("host%u: lport %6.6x: xid %d invalid CPU %d\n:",
947 lport->host->host_no, lport->port_id, xid, cpu);
951 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
952 pool = per_cpu_ptr(mp->pool, cpu);
953 spin_lock_bh(&pool->lock);
954 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
955 if (ep == &fc_quarantine_exch) {
956 FC_LPORT_DBG(lport, "xid %x quarantined\n", xid);
960 WARN_ON(ep->xid != xid);
963 spin_unlock_bh(&pool->lock);
970 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and
971 * the memory allocated for the related objects may be freed.
972 * @sp: The sequence that has completed
974 * Note: May sleep if invoked from outside a response handler.
976 void fc_exch_done(struct fc_seq *sp)
978 struct fc_exch *ep = fc_seq_exch(sp);
981 spin_lock_bh(&ep->ex_lock);
982 rc = fc_exch_done_locked(ep);
983 spin_unlock_bh(&ep->ex_lock);
985 fc_seq_set_resp(sp, NULL, ep->arg);
989 EXPORT_SYMBOL(fc_exch_done);
992 * fc_exch_resp() - Allocate a new exchange for a response frame
993 * @lport: The local port that the exchange was for
994 * @mp: The exchange manager to allocate the exchange from
995 * @fp: The response frame
997 * Sets the responder ID in the frame header.
999 static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
1000 struct fc_exch_mgr *mp,
1001 struct fc_frame *fp)
1004 struct fc_frame_header *fh;
1006 ep = fc_exch_alloc(lport, fp);
1008 ep->class = fc_frame_class(fp);
1011 * Set EX_CTX indicating we're responding on this exchange.
1013 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
1014 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
1015 fh = fc_frame_header_get(fp);
1016 ep->sid = ntoh24(fh->fh_d_id);
1017 ep->did = ntoh24(fh->fh_s_id);
1021 * Allocated exchange has placed the XID in the
1022 * originator field. Move it to the responder field,
1023 * and set the originator XID from the frame.
1026 ep->oxid = ntohs(fh->fh_ox_id);
1027 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
1028 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
1029 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
1031 fc_exch_hold(ep); /* hold for caller */
1032 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
1038 * fc_seq_lookup_recip() - Find a sequence where the other end
1039 * originated the sequence
1040 * @lport: The local port that the frame was sent to
1041 * @mp: The Exchange Manager to lookup the exchange from
1042 * @fp: The frame associated with the sequence we're looking for
1044 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
1045 * on the ep that should be released by the caller.
1047 static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
1048 struct fc_exch_mgr *mp,
1049 struct fc_frame *fp)
1051 struct fc_frame_header *fh = fc_frame_header_get(fp);
1052 struct fc_exch *ep = NULL;
1053 struct fc_seq *sp = NULL;
1054 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
1058 f_ctl = ntoh24(fh->fh_f_ctl);
1059 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
1062 * Lookup or create the exchange if we will be creating the sequence.
1064 if (f_ctl & FC_FC_EX_CTX) {
1065 xid = ntohs(fh->fh_ox_id); /* we originated exch */
1066 ep = fc_exch_find(mp, xid);
1068 atomic_inc(&mp->stats.xid_not_found);
1069 reject = FC_RJT_OX_ID;
1072 if (ep->rxid == FC_XID_UNKNOWN)
1073 ep->rxid = ntohs(fh->fh_rx_id);
1074 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
1075 reject = FC_RJT_OX_ID;
1079 xid = ntohs(fh->fh_rx_id); /* we are the responder */
1082 * Special case for MDS issuing an ELS TEST with a
1084 * XXX take this out once we do the proper reject.
1086 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
1087 fc_frame_payload_op(fp) == ELS_TEST) {
1088 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
1089 xid = FC_XID_UNKNOWN;
1093 * new sequence - find the exchange
1095 ep = fc_exch_find(mp, xid);
1096 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
1098 atomic_inc(&mp->stats.xid_busy);
1099 reject = FC_RJT_RX_ID;
1102 ep = fc_exch_resp(lport, mp, fp);
1104 reject = FC_RJT_EXCH_EST; /* XXX */
1107 xid = ep->xid; /* get our XID */
1109 atomic_inc(&mp->stats.xid_not_found);
1110 reject = FC_RJT_RX_ID; /* XID not found */
1115 spin_lock_bh(&ep->ex_lock);
1117 * At this point, we have the exchange held.
1118 * Find or create the sequence.
1120 if (fc_sof_is_init(fr_sof(fp))) {
1122 sp->ssb_stat |= SSB_ST_RESP;
1123 sp->id = fh->fh_seq_id;
1126 if (sp->id != fh->fh_seq_id) {
1127 atomic_inc(&mp->stats.seq_not_found);
1128 if (f_ctl & FC_FC_END_SEQ) {
1130 * Update sequence_id based on incoming last
1131 * frame of sequence exchange. This is needed
1132 * for FC target where DDP has been used
1133 * on target where, stack is indicated only
1134 * about last frame's (payload _header) header.
1135 * Whereas "seq_id" which is part of
1136 * frame_header is allocated by initiator
1137 * which is totally different from "seq_id"
1138 * allocated when XFER_RDY was sent by target.
1139 * To avoid false -ve which results into not
1140 * sending RSP, hence write request on other
1141 * end never finishes.
1143 sp->ssb_stat |= SSB_ST_RESP;
1144 sp->id = fh->fh_seq_id;
1146 spin_unlock_bh(&ep->ex_lock);
1148 /* sequence/exch should exist */
1149 reject = FC_RJT_SEQ_ID;
1154 WARN_ON(ep != fc_seq_exch(sp));
1156 if (f_ctl & FC_FC_SEQ_INIT)
1157 ep->esb_stat |= ESB_ST_SEQ_INIT;
1158 spin_unlock_bh(&ep->ex_lock);
1164 fc_exch_done(&ep->seq);
1165 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
1170 * fc_seq_lookup_orig() - Find a sequence where this end
1171 * originated the sequence
1172 * @mp: The Exchange Manager to lookup the exchange from
1173 * @fp: The frame associated with the sequence we're looking for
1175 * Does not hold the sequence for the caller.
1177 static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
1178 struct fc_frame *fp)
1180 struct fc_frame_header *fh = fc_frame_header_get(fp);
1182 struct fc_seq *sp = NULL;
1186 f_ctl = ntoh24(fh->fh_f_ctl);
1187 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
1188 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
1189 ep = fc_exch_find(mp, xid);
1192 if (ep->seq.id == fh->fh_seq_id) {
1194 * Save the RX_ID if we didn't previously know it.
1197 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
1198 ep->rxid == FC_XID_UNKNOWN) {
1199 ep->rxid = ntohs(fh->fh_rx_id);
1202 fc_exch_release(ep);
1207 * fc_exch_set_addr() - Set the source and destination IDs for an exchange
1208 * @ep: The exchange to set the addresses for
1209 * @orig_id: The originator's ID
1210 * @resp_id: The responder's ID
1212 * Note this must be done before the first sequence of the exchange is sent.
1214 static void fc_exch_set_addr(struct fc_exch *ep,
1215 u32 orig_id, u32 resp_id)
1218 if (ep->esb_stat & ESB_ST_RESP) {
1228 * fc_seq_els_rsp_send() - Send an ELS response using information from
1229 * the existing sequence/exchange.
1230 * @fp: The received frame
1231 * @els_cmd: The ELS command to be sent
1232 * @els_data: The ELS data to be sent
1234 * The received frame is not freed.
1236 void fc_seq_els_rsp_send(struct fc_frame *fp, enum fc_els_cmd els_cmd,
1237 struct fc_seq_els_data *els_data)
1241 fc_seq_ls_rjt(fp, els_data->reason, els_data->explan);
1247 fc_exch_els_rrq(fp);
1250 fc_exch_els_rec(fp);
1253 FC_LPORT_DBG(fr_dev(fp), "Invalid ELS CMD:%x\n", els_cmd);
1256 EXPORT_SYMBOL_GPL(fc_seq_els_rsp_send);
1259 * fc_seq_send_last() - Send a sequence that is the last in the exchange
1260 * @sp: The sequence that is to be sent
1261 * @fp: The frame that will be sent on the sequence
1262 * @rctl: The R_CTL information to be sent
1263 * @fh_type: The frame header type
1265 static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
1266 enum fc_rctl rctl, enum fc_fh_type fh_type)
1269 struct fc_exch *ep = fc_seq_exch(sp);
1271 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
1273 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
1274 fc_seq_send_locked(ep->lp, sp, fp);
1278 * fc_seq_send_ack() - Send an acknowledgement that we've received a frame
1279 * @sp: The sequence to send the ACK on
1280 * @rx_fp: The received frame that is being acknoledged
1282 * Send ACK_1 (or equiv.) indicating we received something.
1284 static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
1286 struct fc_frame *fp;
1287 struct fc_frame_header *rx_fh;
1288 struct fc_frame_header *fh;
1289 struct fc_exch *ep = fc_seq_exch(sp);
1290 struct fc_lport *lport = ep->lp;
1294 * Don't send ACKs for class 3.
1296 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
1297 fp = fc_frame_alloc(lport, 0);
1299 FC_EXCH_DBG(ep, "Drop ACK request, out of memory\n");
1303 fh = fc_frame_header_get(fp);
1304 fh->fh_r_ctl = FC_RCTL_ACK_1;
1305 fh->fh_type = FC_TYPE_BLS;
1308 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1309 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1310 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1311 * Last ACK uses bits 7-6 (continue sequence),
1312 * bits 5-4 are meaningful (what kind of ACK to use).
1314 rx_fh = fc_frame_header_get(rx_fp);
1315 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1316 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1317 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
1318 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
1319 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1320 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1321 hton24(fh->fh_f_ctl, f_ctl);
1323 fc_exch_setup_hdr(ep, fp, f_ctl);
1324 fh->fh_seq_id = rx_fh->fh_seq_id;
1325 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1326 fh->fh_parm_offset = htonl(1); /* ack single frame */
1328 fr_sof(fp) = fr_sof(rx_fp);
1329 if (f_ctl & FC_FC_END_SEQ)
1330 fr_eof(fp) = FC_EOF_T;
1332 fr_eof(fp) = FC_EOF_N;
1334 lport->tt.frame_send(lport, fp);
1339 * fc_exch_send_ba_rjt() - Send BLS Reject
1340 * @rx_fp: The frame being rejected
1341 * @reason: The reason the frame is being rejected
1342 * @explan: The explanation for the rejection
1344 * This is for rejecting BA_ABTS only.
1346 static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
1347 enum fc_ba_rjt_reason reason,
1348 enum fc_ba_rjt_explan explan)
1350 struct fc_frame *fp;
1351 struct fc_frame_header *rx_fh;
1352 struct fc_frame_header *fh;
1353 struct fc_ba_rjt *rp;
1355 struct fc_lport *lport;
1358 lport = fr_dev(rx_fp);
1360 fp = fc_frame_alloc(lport, sizeof(*rp));
1362 FC_EXCH_DBG(fc_seq_exch(sp),
1363 "Drop BA_RJT request, out of memory\n");
1366 fh = fc_frame_header_get(fp);
1367 rx_fh = fc_frame_header_get(rx_fp);
1369 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1371 rp = fc_frame_payload_get(fp, sizeof(*rp));
1372 rp->br_reason = reason;
1373 rp->br_explan = explan;
1376 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1378 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1379 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1380 fh->fh_ox_id = rx_fh->fh_ox_id;
1381 fh->fh_rx_id = rx_fh->fh_rx_id;
1382 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1383 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1384 fh->fh_type = FC_TYPE_BLS;
1387 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1388 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1389 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1390 * Last ACK uses bits 7-6 (continue sequence),
1391 * bits 5-4 are meaningful (what kind of ACK to use).
1392 * Always set LAST_SEQ, END_SEQ.
1394 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1395 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1396 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1397 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1398 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1399 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1400 f_ctl &= ~FC_FC_FIRST_SEQ;
1401 hton24(fh->fh_f_ctl, f_ctl);
1403 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1404 fr_eof(fp) = FC_EOF_T;
1405 if (fc_sof_needs_ack(fr_sof(fp)))
1406 fr_eof(fp) = FC_EOF_N;
1408 lport->tt.frame_send(lport, fp);
1412 * fc_exch_recv_abts() - Handle an incoming ABTS
1413 * @ep: The exchange the abort was on
1414 * @rx_fp: The ABTS frame
1416 * This would be for target mode usually, but could be due to lost
1417 * FCP transfer ready, confirm or RRQ. We always handle this as an
1418 * exchange abort, ignoring the parameter.
1420 static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1422 struct fc_frame *fp;
1423 struct fc_ba_acc *ap;
1424 struct fc_frame_header *fh;
1430 FC_EXCH_DBG(ep, "exch: ABTS received\n");
1431 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1433 FC_EXCH_DBG(ep, "Drop ABTS request, out of memory\n");
1437 spin_lock_bh(&ep->ex_lock);
1438 if (ep->esb_stat & ESB_ST_COMPLETE) {
1439 spin_unlock_bh(&ep->ex_lock);
1440 FC_EXCH_DBG(ep, "exch: ABTS rejected, exchange complete\n");
1444 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
1445 ep->esb_stat |= ESB_ST_REC_QUAL;
1446 fc_exch_hold(ep); /* hold for REC_QUAL */
1448 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1449 fh = fc_frame_header_get(fp);
1450 ap = fc_frame_payload_get(fp, sizeof(*ap));
1451 memset(ap, 0, sizeof(*ap));
1453 ap->ba_high_seq_cnt = htons(0xffff);
1454 if (sp->ssb_stat & SSB_ST_RESP) {
1455 ap->ba_seq_id = sp->id;
1456 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1457 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1458 ap->ba_low_seq_cnt = htons(sp->cnt);
1460 sp = fc_seq_start_next_locked(sp);
1461 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1462 ep->esb_stat |= ESB_ST_ABNORMAL;
1463 spin_unlock_bh(&ep->ex_lock);
1466 fc_frame_free(rx_fp);
1470 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1475 * fc_seq_assign() - Assign exchange and sequence for incoming request
1476 * @lport: The local port that received the request
1477 * @fp: The request frame
1479 * On success, the sequence pointer will be returned and also in fr_seq(@fp).
1480 * A reference will be held on the exchange/sequence for the caller, which
1481 * must call fc_seq_release().
1483 struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)
1485 struct fc_exch_mgr_anchor *ema;
1487 WARN_ON(lport != fr_dev(fp));
1488 WARN_ON(fr_seq(fp));
1491 list_for_each_entry(ema, &lport->ema_list, ema_list)
1492 if ((!ema->match || ema->match(fp)) &&
1493 fc_seq_lookup_recip(lport, ema->mp, fp) == FC_RJT_NONE)
1497 EXPORT_SYMBOL(fc_seq_assign);
1500 * fc_seq_release() - Release the hold
1501 * @sp: The sequence.
1503 void fc_seq_release(struct fc_seq *sp)
1505 fc_exch_release(fc_seq_exch(sp));
1507 EXPORT_SYMBOL(fc_seq_release);
1510 * fc_exch_recv_req() - Handler for an incoming request
1511 * @lport: The local port that received the request
1512 * @mp: The EM that the exchange is on
1513 * @fp: The request frame
1515 * This is used when the other end is originating the exchange
1518 static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp,
1519 struct fc_frame *fp)
1521 struct fc_frame_header *fh = fc_frame_header_get(fp);
1522 struct fc_seq *sp = NULL;
1523 struct fc_exch *ep = NULL;
1524 enum fc_pf_rjt_reason reject;
1526 /* We can have the wrong fc_lport at this point with NPIV, which is a
1527 * problem now that we know a new exchange needs to be allocated
1529 lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id));
1536 BUG_ON(fr_seq(fp)); /* XXX remove later */
1539 * If the RX_ID is 0xffff, don't allocate an exchange.
1540 * The upper-level protocol may request one later, if needed.
1542 if (fh->fh_rx_id == htons(FC_XID_UNKNOWN))
1543 return fc_lport_recv(lport, fp);
1545 reject = fc_seq_lookup_recip(lport, mp, fp);
1546 if (reject == FC_RJT_NONE) {
1547 sp = fr_seq(fp); /* sequence will be held */
1548 ep = fc_seq_exch(sp);
1549 fc_seq_send_ack(sp, fp);
1550 ep->encaps = fr_encaps(fp);
1553 * Call the receive function.
1555 * The receive function may allocate a new sequence
1556 * over the old one, so we shouldn't change the
1557 * sequence after this.
1559 * The frame will be freed by the receive function.
1560 * If new exch resp handler is valid then call that
1563 if (!fc_invoke_resp(ep, sp, fp))
1564 fc_lport_recv(lport, fp);
1565 fc_exch_release(ep); /* release from lookup */
1567 FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n",
1574 * fc_exch_recv_seq_resp() - Handler for an incoming response where the other
1575 * end is the originator of the sequence that is a
1576 * response to our initial exchange
1577 * @mp: The EM that the exchange is on
1578 * @fp: The response frame
1580 static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1582 struct fc_frame_header *fh = fc_frame_header_get(fp);
1589 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1591 atomic_inc(&mp->stats.xid_not_found);
1594 if (ep->esb_stat & ESB_ST_COMPLETE) {
1595 atomic_inc(&mp->stats.xid_not_found);
1598 if (ep->rxid == FC_XID_UNKNOWN)
1599 ep->rxid = ntohs(fh->fh_rx_id);
1600 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1601 atomic_inc(&mp->stats.xid_not_found);
1604 if (ep->did != ntoh24(fh->fh_s_id) &&
1605 ep->did != FC_FID_FLOGI) {
1606 atomic_inc(&mp->stats.xid_not_found);
1611 if (fc_sof_is_init(sof)) {
1612 sp->ssb_stat |= SSB_ST_RESP;
1613 sp->id = fh->fh_seq_id;
1616 f_ctl = ntoh24(fh->fh_f_ctl);
1619 spin_lock_bh(&ep->ex_lock);
1620 if (f_ctl & FC_FC_SEQ_INIT)
1621 ep->esb_stat |= ESB_ST_SEQ_INIT;
1622 spin_unlock_bh(&ep->ex_lock);
1624 if (fc_sof_needs_ack(sof))
1625 fc_seq_send_ack(sp, fp);
1627 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1628 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1629 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1630 spin_lock_bh(&ep->ex_lock);
1631 rc = fc_exch_done_locked(ep);
1632 WARN_ON(fc_seq_exch(sp) != ep);
1633 spin_unlock_bh(&ep->ex_lock);
1637 FC_EXCH_DBG(ep, "ep is completed already,"
1638 "hence skip calling the resp\n");
1644 * Call the receive function.
1645 * The sequence is held (has a refcnt) for us,
1646 * but not for the receive function.
1648 * The receive function may allocate a new sequence
1649 * over the old one, so we shouldn't change the
1650 * sequence after this.
1652 * The frame will be freed by the receive function.
1653 * If new exch resp handler is valid then call that
1656 if (!fc_invoke_resp(ep, sp, fp))
1660 fc_exch_release(ep);
1663 fc_exch_release(ep);
1669 * fc_exch_recv_resp() - Handler for a sequence where other end is
1670 * responding to our sequence
1671 * @mp: The EM that the exchange is on
1672 * @fp: The response frame
1674 static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1678 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1681 atomic_inc(&mp->stats.xid_not_found);
1683 atomic_inc(&mp->stats.non_bls_resp);
1689 * fc_exch_abts_resp() - Handler for a response to an ABT
1690 * @ep: The exchange that the frame is on
1691 * @fp: The response frame
1693 * This response would be to an ABTS cancelling an exchange or sequence.
1694 * The response can be either BA_ACC or BA_RJT
1696 static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1698 struct fc_frame_header *fh;
1699 struct fc_ba_acc *ap;
1703 int rc = 1, has_rec = 0;
1705 fh = fc_frame_header_get(fp);
1706 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1707 fc_exch_rctl_name(fh->fh_r_ctl));
1709 if (cancel_delayed_work_sync(&ep->timeout_work)) {
1710 FC_EXCH_DBG(ep, "Exchange timer canceled due to ABTS response\n");
1711 fc_exch_release(ep); /* release from pending timer hold */
1715 spin_lock_bh(&ep->ex_lock);
1716 switch (fh->fh_r_ctl) {
1717 case FC_RCTL_BA_ACC:
1718 ap = fc_frame_payload_get(fp, sizeof(*ap));
1723 * Decide whether to establish a Recovery Qualifier.
1724 * We do this if there is a non-empty SEQ_CNT range and
1725 * SEQ_ID is the same as the one we aborted.
1727 low = ntohs(ap->ba_low_seq_cnt);
1728 high = ntohs(ap->ba_high_seq_cnt);
1729 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1730 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1731 ap->ba_seq_id == ep->seq_id) && low != high) {
1732 ep->esb_stat |= ESB_ST_REC_QUAL;
1733 fc_exch_hold(ep); /* hold for recovery qualifier */
1737 case FC_RCTL_BA_RJT:
1743 /* do we need to do some other checks here. Can we reuse more of
1744 * fc_exch_recv_seq_resp
1748 * do we want to check END_SEQ as well as LAST_SEQ here?
1750 if (ep->fh_type != FC_TYPE_FCP &&
1751 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1752 rc = fc_exch_done_locked(ep);
1753 spin_unlock_bh(&ep->ex_lock);
1758 if (!fc_invoke_resp(ep, sp, fp))
1761 fc_exch_timer_set(ep, ep->r_a_tov);
1762 fc_exch_release(ep);
1766 * fc_exch_recv_bls() - Handler for a BLS sequence
1767 * @mp: The EM that the exchange is on
1768 * @fp: The request frame
1770 * The BLS frame is always a sequence initiated by the remote side.
1771 * We may be either the originator or recipient of the exchange.
1773 static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1775 struct fc_frame_header *fh;
1779 fh = fc_frame_header_get(fp);
1780 f_ctl = ntoh24(fh->fh_f_ctl);
1783 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1784 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1785 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1786 spin_lock_bh(&ep->ex_lock);
1787 ep->esb_stat |= ESB_ST_SEQ_INIT;
1788 spin_unlock_bh(&ep->ex_lock);
1790 if (f_ctl & FC_FC_SEQ_CTX) {
1792 * A response to a sequence we initiated.
1793 * This should only be ACKs for class 2 or F.
1795 switch (fh->fh_r_ctl) {
1801 FC_EXCH_DBG(ep, "BLS rctl %x - %s received\n",
1803 fc_exch_rctl_name(fh->fh_r_ctl));
1808 switch (fh->fh_r_ctl) {
1809 case FC_RCTL_BA_RJT:
1810 case FC_RCTL_BA_ACC:
1812 fc_exch_abts_resp(ep, fp);
1816 case FC_RCTL_BA_ABTS:
1818 fc_exch_recv_abts(ep, fp);
1822 default: /* ignore junk */
1828 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1832 * fc_seq_ls_acc() - Accept sequence with LS_ACC
1833 * @rx_fp: The received frame, not freed here.
1835 * If this fails due to allocation or transmit congestion, assume the
1836 * originator will repeat the sequence.
1838 static void fc_seq_ls_acc(struct fc_frame *rx_fp)
1840 struct fc_lport *lport;
1841 struct fc_els_ls_acc *acc;
1842 struct fc_frame *fp;
1845 lport = fr_dev(rx_fp);
1847 fp = fc_frame_alloc(lport, sizeof(*acc));
1849 FC_EXCH_DBG(fc_seq_exch(sp),
1850 "exch: drop LS_ACC, out of memory\n");
1853 acc = fc_frame_payload_get(fp, sizeof(*acc));
1854 memset(acc, 0, sizeof(*acc));
1855 acc->la_cmd = ELS_LS_ACC;
1856 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1857 lport->tt.frame_send(lport, fp);
1861 * fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT
1862 * @rx_fp: The received frame, not freed here.
1863 * @reason: The reason the sequence is being rejected
1864 * @explan: The explanation for the rejection
1866 * If this fails due to allocation or transmit congestion, assume the
1867 * originator will repeat the sequence.
1869 static void fc_seq_ls_rjt(struct fc_frame *rx_fp, enum fc_els_rjt_reason reason,
1870 enum fc_els_rjt_explan explan)
1872 struct fc_lport *lport;
1873 struct fc_els_ls_rjt *rjt;
1874 struct fc_frame *fp;
1877 lport = fr_dev(rx_fp);
1879 fp = fc_frame_alloc(lport, sizeof(*rjt));
1881 FC_EXCH_DBG(fc_seq_exch(sp),
1882 "exch: drop LS_ACC, out of memory\n");
1885 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1886 memset(rjt, 0, sizeof(*rjt));
1887 rjt->er_cmd = ELS_LS_RJT;
1888 rjt->er_reason = reason;
1889 rjt->er_explan = explan;
1890 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1891 lport->tt.frame_send(lport, fp);
1895 * fc_exch_reset() - Reset an exchange
1896 * @ep: The exchange to be reset
1898 * Note: May sleep if invoked from outside a response handler.
1900 static void fc_exch_reset(struct fc_exch *ep)
1905 spin_lock_bh(&ep->ex_lock);
1906 ep->state |= FC_EX_RST_CLEANUP;
1907 fc_exch_timer_cancel(ep);
1908 if (ep->esb_stat & ESB_ST_REC_QUAL)
1909 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1910 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1912 rc = fc_exch_done_locked(ep);
1913 spin_unlock_bh(&ep->ex_lock);
1920 FC_EXCH_DBG(ep, "ep is completed already,"
1921 "hence skip calling the resp\n");
1925 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_CLOSED));
1927 fc_seq_set_resp(sp, NULL, ep->arg);
1928 fc_exch_release(ep);
1932 * fc_exch_pool_reset() - Reset a per cpu exchange pool
1933 * @lport: The local port that the exchange pool is on
1934 * @pool: The exchange pool to be reset
1935 * @sid: The source ID
1936 * @did: The destination ID
1938 * Resets a per cpu exches pool, releasing all of its sequences
1939 * and exchanges. If sid is non-zero then reset only exchanges
1940 * we sourced from the local port's FID. If did is non-zero then
1941 * only reset exchanges destined for the local port's FID.
1943 static void fc_exch_pool_reset(struct fc_lport *lport,
1944 struct fc_exch_pool *pool,
1948 struct fc_exch *next;
1950 spin_lock_bh(&pool->lock);
1952 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1953 if ((lport == ep->lp) &&
1954 (sid == 0 || sid == ep->sid) &&
1955 (did == 0 || did == ep->did)) {
1957 spin_unlock_bh(&pool->lock);
1961 fc_exch_release(ep);
1962 spin_lock_bh(&pool->lock);
1965 * must restart loop incase while lock
1966 * was down multiple eps were released.
1971 pool->next_index = 0;
1972 pool->left = FC_XID_UNKNOWN;
1973 pool->right = FC_XID_UNKNOWN;
1974 spin_unlock_bh(&pool->lock);
1978 * fc_exch_mgr_reset() - Reset all EMs of a local port
1979 * @lport: The local port whose EMs are to be reset
1980 * @sid: The source ID
1981 * @did: The destination ID
1983 * Reset all EMs associated with a given local port. Release all
1984 * sequences and exchanges. If sid is non-zero then reset only the
1985 * exchanges sent from the local port's FID. If did is non-zero then
1986 * reset only exchanges destined for the local port's FID.
1988 void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1990 struct fc_exch_mgr_anchor *ema;
1993 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1994 for_each_possible_cpu(cpu)
1995 fc_exch_pool_reset(lport,
1996 per_cpu_ptr(ema->mp->pool, cpu),
2000 EXPORT_SYMBOL(fc_exch_mgr_reset);
2003 * fc_exch_lookup() - find an exchange
2004 * @lport: The local port
2005 * @xid: The exchange ID
2007 * Returns exchange pointer with hold for caller, or NULL if not found.
2009 static struct fc_exch *fc_exch_lookup(struct fc_lport *lport, u32 xid)
2011 struct fc_exch_mgr_anchor *ema;
2013 list_for_each_entry(ema, &lport->ema_list, ema_list)
2014 if (ema->mp->min_xid <= xid && xid <= ema->mp->max_xid)
2015 return fc_exch_find(ema->mp, xid);
2020 * fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests
2021 * @rfp: The REC frame, not freed here.
2023 * Note that the requesting port may be different than the S_ID in the request.
2025 static void fc_exch_els_rec(struct fc_frame *rfp)
2027 struct fc_lport *lport;
2028 struct fc_frame *fp;
2030 struct fc_els_rec *rp;
2031 struct fc_els_rec_acc *acc;
2032 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
2033 enum fc_els_rjt_explan explan;
2035 u16 xid, rxid, oxid;
2037 lport = fr_dev(rfp);
2038 rp = fc_frame_payload_get(rfp, sizeof(*rp));
2039 explan = ELS_EXPL_INV_LEN;
2042 sid = ntoh24(rp->rec_s_id);
2043 rxid = ntohs(rp->rec_rx_id);
2044 oxid = ntohs(rp->rec_ox_id);
2046 explan = ELS_EXPL_OXID_RXID;
2047 if (sid == fc_host_port_id(lport->host))
2051 if (xid == FC_XID_UNKNOWN) {
2053 "REC request from %x: invalid rxid %x oxid %x\n",
2057 ep = fc_exch_lookup(lport, xid);
2060 "REC request from %x: rxid %x oxid %x not found\n",
2064 FC_EXCH_DBG(ep, "REC request from %x: rxid %x oxid %x\n",
2066 if (ep->oid != sid || oxid != ep->oxid)
2068 if (rxid != FC_XID_UNKNOWN && rxid != ep->rxid)
2070 fp = fc_frame_alloc(lport, sizeof(*acc));
2072 FC_EXCH_DBG(ep, "Drop REC request, out of memory\n");
2076 acc = fc_frame_payload_get(fp, sizeof(*acc));
2077 memset(acc, 0, sizeof(*acc));
2078 acc->reca_cmd = ELS_LS_ACC;
2079 acc->reca_ox_id = rp->rec_ox_id;
2080 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
2081 acc->reca_rx_id = htons(ep->rxid);
2082 if (ep->sid == ep->oid)
2083 hton24(acc->reca_rfid, ep->did);
2085 hton24(acc->reca_rfid, ep->sid);
2086 acc->reca_fc4value = htonl(ep->seq.rec_data);
2087 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
2090 fc_fill_reply_hdr(fp, rfp, FC_RCTL_ELS_REP, 0);
2091 lport->tt.frame_send(lport, fp);
2093 fc_exch_release(ep);
2097 fc_exch_release(ep);
2099 fc_seq_ls_rjt(rfp, reason, explan);
2103 * fc_exch_rrq_resp() - Handler for RRQ responses
2104 * @sp: The sequence that the RRQ is on
2105 * @fp: The RRQ frame
2106 * @arg: The exchange that the RRQ is on
2108 * TODO: fix error handler.
2110 static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
2112 struct fc_exch *aborted_ep = arg;
2116 int err = PTR_ERR(fp);
2118 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
2120 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
2121 "frame error %d\n", err);
2125 op = fc_frame_payload_op(fp);
2130 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ\n");
2135 FC_EXCH_DBG(aborted_ep, "unexpected response op %x for RRQ\n",
2141 fc_exch_done(&aborted_ep->seq);
2142 /* drop hold for rec qual */
2143 fc_exch_release(aborted_ep);
2148 * fc_exch_seq_send() - Send a frame using a new exchange and sequence
2149 * @lport: The local port to send the frame on
2150 * @fp: The frame to be sent
2151 * @resp: The response handler for this request
2152 * @destructor: The destructor for the exchange
2153 * @arg: The argument to be passed to the response handler
2154 * @timer_msec: The timeout period for the exchange
2156 * The exchange response handler is set in this routine to resp()
2157 * function pointer. It can be called in two scenarios: if a timeout
2158 * occurs or if a response frame is received for the exchange. The
2159 * fc_frame pointer in response handler will also indicate timeout
2160 * as error using IS_ERR related macros.
2162 * The exchange destructor handler is also set in this routine.
2163 * The destructor handler is invoked by EM layer when exchange
2164 * is about to free, this can be used by caller to free its
2165 * resources along with exchange free.
2167 * The arg is passed back to resp and destructor handler.
2169 * The timeout value (in msec) for an exchange is set if non zero
2170 * timer_msec argument is specified. The timer is canceled when
2171 * it fires or when the exchange is done. The exchange timeout handler
2172 * is registered by EM layer.
2174 * The frame pointer with some of the header's fields must be
2175 * filled before calling this routine, those fields are:
2182 * - parameter or relative offset
2184 struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
2185 struct fc_frame *fp,
2186 void (*resp)(struct fc_seq *,
2187 struct fc_frame *fp,
2189 void (*destructor)(struct fc_seq *, void *),
2190 void *arg, u32 timer_msec)
2193 struct fc_seq *sp = NULL;
2194 struct fc_frame_header *fh;
2195 struct fc_fcp_pkt *fsp = NULL;
2198 ep = fc_exch_alloc(lport, fp);
2203 ep->esb_stat |= ESB_ST_SEQ_INIT;
2204 fh = fc_frame_header_get(fp);
2205 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
2207 ep->destructor = destructor;
2209 ep->r_a_tov = lport->r_a_tov;
2213 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
2214 ep->f_ctl = ntoh24(fh->fh_f_ctl);
2215 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
2218 if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD) {
2220 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
2223 if (unlikely(lport->tt.frame_send(lport, fp)))
2227 fc_exch_timer_set_locked(ep, timer_msec);
2228 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
2230 if (ep->f_ctl & FC_FC_SEQ_INIT)
2231 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
2232 spin_unlock_bh(&ep->ex_lock);
2236 fc_fcp_ddp_done(fsp);
2237 rc = fc_exch_done_locked(ep);
2238 spin_unlock_bh(&ep->ex_lock);
2243 EXPORT_SYMBOL(fc_exch_seq_send);
2246 * fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command
2247 * @ep: The exchange to send the RRQ on
2249 * This tells the remote port to stop blocking the use of
2250 * the exchange and the seq_cnt range.
2252 static void fc_exch_rrq(struct fc_exch *ep)
2254 struct fc_lport *lport;
2255 struct fc_els_rrq *rrq;
2256 struct fc_frame *fp;
2261 fp = fc_frame_alloc(lport, sizeof(*rrq));
2265 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
2266 memset(rrq, 0, sizeof(*rrq));
2267 rrq->rrq_cmd = ELS_RRQ;
2268 hton24(rrq->rrq_s_id, ep->sid);
2269 rrq->rrq_ox_id = htons(ep->oxid);
2270 rrq->rrq_rx_id = htons(ep->rxid);
2273 if (ep->esb_stat & ESB_ST_RESP)
2276 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
2277 lport->port_id, FC_TYPE_ELS,
2278 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
2280 if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep,
2285 FC_EXCH_DBG(ep, "exch: RRQ send failed\n");
2286 spin_lock_bh(&ep->ex_lock);
2287 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
2288 spin_unlock_bh(&ep->ex_lock);
2289 /* drop hold for rec qual */
2290 fc_exch_release(ep);
2293 ep->esb_stat |= ESB_ST_REC_QUAL;
2294 fc_exch_timer_set_locked(ep, ep->r_a_tov);
2295 spin_unlock_bh(&ep->ex_lock);
2299 * fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests
2300 * @fp: The RRQ frame, not freed here.
2302 static void fc_exch_els_rrq(struct fc_frame *fp)
2304 struct fc_lport *lport;
2305 struct fc_exch *ep = NULL; /* request or subject exchange */
2306 struct fc_els_rrq *rp;
2309 enum fc_els_rjt_explan explan;
2312 rp = fc_frame_payload_get(fp, sizeof(*rp));
2313 explan = ELS_EXPL_INV_LEN;
2318 * lookup subject exchange.
2320 sid = ntoh24(rp->rrq_s_id); /* subject source */
2321 xid = fc_host_port_id(lport->host) == sid ?
2322 ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
2323 ep = fc_exch_lookup(lport, xid);
2324 explan = ELS_EXPL_OXID_RXID;
2327 spin_lock_bh(&ep->ex_lock);
2328 FC_EXCH_DBG(ep, "RRQ request from %x: xid %x rxid %x oxid %x\n",
2329 sid, xid, ntohs(rp->rrq_rx_id), ntohs(rp->rrq_ox_id));
2330 if (ep->oxid != ntohs(rp->rrq_ox_id))
2332 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
2333 ep->rxid != FC_XID_UNKNOWN)
2335 explan = ELS_EXPL_SID;
2340 * Clear Recovery Qualifier state, and cancel timer if complete.
2342 if (ep->esb_stat & ESB_ST_REC_QUAL) {
2343 ep->esb_stat &= ~ESB_ST_REC_QUAL;
2344 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
2346 if (ep->esb_stat & ESB_ST_COMPLETE)
2347 fc_exch_timer_cancel(ep);
2349 spin_unlock_bh(&ep->ex_lock);
2358 spin_unlock_bh(&ep->ex_lock);
2360 fc_seq_ls_rjt(fp, ELS_RJT_LOGIC, explan);
2363 fc_exch_release(ep); /* drop hold from fc_exch_find */
2367 * fc_exch_update_stats() - update exches stats to lport
2368 * @lport: The local port to update exchange manager stats
2370 void fc_exch_update_stats(struct fc_lport *lport)
2372 struct fc_host_statistics *st;
2373 struct fc_exch_mgr_anchor *ema;
2374 struct fc_exch_mgr *mp;
2376 st = &lport->host_stats;
2378 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2380 st->fc_no_free_exch += atomic_read(&mp->stats.no_free_exch);
2381 st->fc_no_free_exch_xid +=
2382 atomic_read(&mp->stats.no_free_exch_xid);
2383 st->fc_xid_not_found += atomic_read(&mp->stats.xid_not_found);
2384 st->fc_xid_busy += atomic_read(&mp->stats.xid_busy);
2385 st->fc_seq_not_found += atomic_read(&mp->stats.seq_not_found);
2386 st->fc_non_bls_resp += atomic_read(&mp->stats.non_bls_resp);
2389 EXPORT_SYMBOL(fc_exch_update_stats);
2392 * fc_exch_mgr_add() - Add an exchange manager to a local port's list of EMs
2393 * @lport: The local port to add the exchange manager to
2394 * @mp: The exchange manager to be added to the local port
2395 * @match: The match routine that indicates when this EM should be used
2397 struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
2398 struct fc_exch_mgr *mp,
2399 bool (*match)(struct fc_frame *))
2401 struct fc_exch_mgr_anchor *ema;
2403 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
2409 /* add EM anchor to EM anchors list */
2410 list_add_tail(&ema->ema_list, &lport->ema_list);
2411 kref_get(&mp->kref);
2414 EXPORT_SYMBOL(fc_exch_mgr_add);
2417 * fc_exch_mgr_destroy() - Destroy an exchange manager
2418 * @kref: The reference to the EM to be destroyed
2420 static void fc_exch_mgr_destroy(struct kref *kref)
2422 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
2424 mempool_destroy(mp->ep_pool);
2425 free_percpu(mp->pool);
2430 * fc_exch_mgr_del() - Delete an EM from a local port's list
2431 * @ema: The exchange manager anchor identifying the EM to be deleted
2433 void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
2435 /* remove EM anchor from EM anchors list */
2436 list_del(&ema->ema_list);
2437 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
2440 EXPORT_SYMBOL(fc_exch_mgr_del);
2443 * fc_exch_mgr_list_clone() - Share all exchange manager objects
2444 * @src: Source lport to clone exchange managers from
2445 * @dst: New lport that takes references to all the exchange managers
2447 int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)
2449 struct fc_exch_mgr_anchor *ema, *tmp;
2451 list_for_each_entry(ema, &src->ema_list, ema_list) {
2452 if (!fc_exch_mgr_add(dst, ema->mp, ema->match))
2457 list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)
2458 fc_exch_mgr_del(ema);
2461 EXPORT_SYMBOL(fc_exch_mgr_list_clone);
2464 * fc_exch_mgr_alloc() - Allocate an exchange manager
2465 * @lport: The local port that the new EM will be associated with
2466 * @class: The default FC class for new exchanges
2467 * @min_xid: The minimum XID for exchanges from the new EM
2468 * @max_xid: The maximum XID for exchanges from the new EM
2469 * @match: The match routine for the new EM
2471 struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport,
2472 enum fc_class class,
2473 u16 min_xid, u16 max_xid,
2474 bool (*match)(struct fc_frame *))
2476 struct fc_exch_mgr *mp;
2477 u16 pool_exch_range;
2480 struct fc_exch_pool *pool;
2482 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
2483 (min_xid & fc_cpu_mask) != 0) {
2484 FC_LPORT_DBG(lport, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
2490 * allocate memory for EM
2492 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
2498 /* adjust em exch xid range for offload */
2499 mp->min_xid = min_xid;
2501 /* reduce range so per cpu pool fits into PCPU_MIN_UNIT_SIZE pool */
2502 pool_exch_range = (PCPU_MIN_UNIT_SIZE - sizeof(*pool)) /
2503 sizeof(struct fc_exch *);
2504 if ((max_xid - min_xid + 1) / (fc_cpu_mask + 1) > pool_exch_range) {
2505 mp->max_xid = pool_exch_range * (fc_cpu_mask + 1) +
2508 mp->max_xid = max_xid;
2509 pool_exch_range = (mp->max_xid - mp->min_xid + 1) /
2513 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
2518 * Setup per cpu exch pool with entire exchange id range equally
2519 * divided across all cpus. The exch pointers array memory is
2520 * allocated for exch range per pool.
2522 mp->pool_max_index = pool_exch_range - 1;
2525 * Allocate and initialize per cpu exch pool
2527 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
2528 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
2531 for_each_possible_cpu(cpu) {
2532 pool = per_cpu_ptr(mp->pool, cpu);
2533 pool->next_index = 0;
2534 pool->left = FC_XID_UNKNOWN;
2535 pool->right = FC_XID_UNKNOWN;
2536 spin_lock_init(&pool->lock);
2537 INIT_LIST_HEAD(&pool->ex_list);
2540 kref_init(&mp->kref);
2541 if (!fc_exch_mgr_add(lport, mp, match)) {
2542 free_percpu(mp->pool);
2547 * Above kref_init() sets mp->kref to 1 and then
2548 * call to fc_exch_mgr_add incremented mp->kref again,
2549 * so adjust that extra increment.
2551 kref_put(&mp->kref, fc_exch_mgr_destroy);
2555 mempool_destroy(mp->ep_pool);
2560 EXPORT_SYMBOL(fc_exch_mgr_alloc);
2563 * fc_exch_mgr_free() - Free all exchange managers on a local port
2564 * @lport: The local port whose EMs are to be freed
2566 void fc_exch_mgr_free(struct fc_lport *lport)
2568 struct fc_exch_mgr_anchor *ema, *next;
2570 flush_workqueue(fc_exch_workqueue);
2571 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
2572 fc_exch_mgr_del(ema);
2574 EXPORT_SYMBOL(fc_exch_mgr_free);
2577 * fc_find_ema() - Lookup and return appropriate Exchange Manager Anchor depending
2580 * @lport: The local port the frame was received on
2581 * @fh: The received frame header
2583 static struct fc_exch_mgr_anchor *fc_find_ema(u32 f_ctl,
2584 struct fc_lport *lport,
2585 struct fc_frame_header *fh)
2587 struct fc_exch_mgr_anchor *ema;
2590 if (f_ctl & FC_FC_EX_CTX)
2591 xid = ntohs(fh->fh_ox_id);
2593 xid = ntohs(fh->fh_rx_id);
2594 if (xid == FC_XID_UNKNOWN)
2595 return list_entry(lport->ema_list.prev,
2596 typeof(*ema), ema_list);
2599 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2600 if ((xid >= ema->mp->min_xid) &&
2601 (xid <= ema->mp->max_xid))
2607 * fc_exch_recv() - Handler for received frames
2608 * @lport: The local port the frame was received on
2609 * @fp: The received frame
2611 void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)
2613 struct fc_frame_header *fh = fc_frame_header_get(fp);
2614 struct fc_exch_mgr_anchor *ema;
2618 if (!lport || lport->state == LPORT_ST_DISABLED) {
2619 FC_LIBFC_DBG("Receiving frames for an lport that "
2620 "has not been initialized correctly\n");
2625 f_ctl = ntoh24(fh->fh_f_ctl);
2626 ema = fc_find_ema(f_ctl, lport, fh);
2628 FC_LPORT_DBG(lport, "Unable to find Exchange Manager Anchor,"
2629 "fc_ctl <0x%x>, xid <0x%x>\n",
2631 (f_ctl & FC_FC_EX_CTX) ?
2632 ntohs(fh->fh_ox_id) :
2633 ntohs(fh->fh_rx_id));
2639 * If frame is marked invalid, just drop it.
2641 switch (fr_eof(fp)) {
2643 if (f_ctl & FC_FC_END_SEQ)
2644 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2647 if (fh->fh_type == FC_TYPE_BLS)
2648 fc_exch_recv_bls(ema->mp, fp);
2649 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2651 fc_exch_recv_seq_resp(ema->mp, fp);
2652 else if (f_ctl & FC_FC_SEQ_CTX)
2653 fc_exch_recv_resp(ema->mp, fp);
2654 else /* no EX_CTX and no SEQ_CTX */
2655 fc_exch_recv_req(lport, ema->mp, fp);
2658 FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)",
2663 EXPORT_SYMBOL(fc_exch_recv);
2666 * fc_exch_init() - Initialize the exchange layer for a local port
2667 * @lport: The local port to initialize the exchange layer for
2669 int fc_exch_init(struct fc_lport *lport)
2671 if (!lport->tt.exch_mgr_reset)
2672 lport->tt.exch_mgr_reset = fc_exch_mgr_reset;
2676 EXPORT_SYMBOL(fc_exch_init);
2679 * fc_setup_exch_mgr() - Setup an exchange manager
2681 int fc_setup_exch_mgr(void)
2683 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2684 0, SLAB_HWCACHE_ALIGN, NULL);
2689 * Initialize fc_cpu_mask and fc_cpu_order. The
2690 * fc_cpu_mask is set for nr_cpu_ids rounded up
2691 * to order of 2's * power and order is stored
2692 * in fc_cpu_order as this is later required in
2693 * mapping between an exch id and exch array index
2694 * in per cpu exch pool.
2696 * This round up is required to align fc_cpu_mask
2697 * to exchange id's lower bits such that all incoming
2698 * frames of an exchange gets delivered to the same
2699 * cpu on which exchange originated by simple bitwise
2700 * AND operation between fc_cpu_mask and exchange id.
2702 fc_cpu_order = ilog2(roundup_pow_of_two(nr_cpu_ids));
2703 fc_cpu_mask = (1 << fc_cpu_order) - 1;
2705 fc_exch_workqueue = create_singlethread_workqueue("fc_exch_workqueue");
2706 if (!fc_exch_workqueue)
2710 kmem_cache_destroy(fc_em_cachep);
2715 * fc_destroy_exch_mgr() - Destroy an exchange manager
2717 void fc_destroy_exch_mgr(void)
2719 destroy_workqueue(fc_exch_workqueue);
2720 kmem_cache_destroy(fc_em_cachep);