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
53 * This structure manages per cpu exchanges in array of exchange pointers.
54 * This array is allocated followed by struct fc_exch_pool memory for
55 * assigned range of exchanges to per cpu pool.
59 struct list_head ex_list;
63 /* two cache of free slot in exch array */
66 } ____cacheline_aligned_in_smp;
69 * struct fc_exch_mgr - The Exchange Manager (EM).
70 * @class: Default class for new sequences
71 * @kref: Reference counter
72 * @min_xid: Minimum exchange ID
73 * @max_xid: Maximum exchange ID
74 * @ep_pool: Reserved exchange pointers
75 * @pool_max_index: Max exch array index in exch pool
76 * @pool: Per cpu exch pool
77 * @stats: Statistics structure
79 * This structure is the center for creating exchanges and sequences.
80 * It manages the allocation of exchange IDs.
83 struct fc_exch_pool __percpu *pool;
85 struct fc_lport *lport;
93 atomic_t no_free_exch;
94 atomic_t no_free_exch_xid;
95 atomic_t xid_not_found;
97 atomic_t seq_not_found;
98 atomic_t non_bls_resp;
103 * struct fc_exch_mgr_anchor - primary structure for list of EMs
104 * @ema_list: Exchange Manager Anchor list
105 * @mp: Exchange Manager associated with this anchor
106 * @match: Routine to determine if this anchor's EM should be used
108 * When walking the list of anchors the match routine will be called
109 * for each anchor to determine if that EM should be used. The last
110 * anchor in the list will always match to handle any exchanges not
111 * handled by other EMs. The non-default EMs would be added to the
112 * anchor list by HW that provides offloads.
114 struct fc_exch_mgr_anchor {
115 struct list_head ema_list;
116 struct fc_exch_mgr *mp;
117 bool (*match)(struct fc_frame *);
120 static void fc_exch_rrq(struct fc_exch *);
121 static void fc_seq_ls_acc(struct fc_frame *);
122 static void fc_seq_ls_rjt(struct fc_frame *, enum fc_els_rjt_reason,
123 enum fc_els_rjt_explan);
124 static void fc_exch_els_rec(struct fc_frame *);
125 static void fc_exch_els_rrq(struct fc_frame *);
128 * Internal implementation notes.
130 * The exchange manager is one by default in libfc but LLD may choose
131 * to have one per CPU. The sequence manager is one per exchange manager
132 * and currently never separated.
134 * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field
135 * assigned by the Sequence Initiator that shall be unique for a specific
136 * D_ID and S_ID pair while the Sequence is open." Note that it isn't
137 * qualified by exchange ID, which one might think it would be.
138 * In practice this limits the number of open sequences and exchanges to 256
139 * per session. For most targets we could treat this limit as per exchange.
141 * The exchange and its sequence are freed when the last sequence is received.
142 * It's possible for the remote port to leave an exchange open without
143 * sending any sequences.
145 * Notes on reference counts:
147 * Exchanges are reference counted and exchange gets freed when the reference
148 * count becomes zero.
151 * Sequences are timed out for E_D_TOV and R_A_TOV.
153 * Sequence event handling:
155 * The following events may occur on initiator sequences:
158 * For now, the whole thing is sent.
160 * This applies only to class F.
161 * The sequence is marked complete.
163 * The upper layer calls fc_exch_done() when done
164 * with exchange and sequence tuple.
165 * RX-inferred completion.
166 * When we receive the next sequence on the same exchange, we can
167 * retire the previous sequence ID. (XXX not implemented).
169 * R_A_TOV frees the sequence ID. If we're waiting for ACK,
170 * E_D_TOV causes abort and calls upper layer response handler
171 * with FC_EX_TIMEOUT error.
177 * The following events may occur on recipient sequences:
180 * Allocate sequence for first frame received.
181 * Hold during receive handler.
182 * Release when final frame received.
183 * Keep status of last N of these for the ELS RES command. XXX TBD.
185 * Deallocate sequence
189 * For now, we neglect conditions where only part of a sequence was
190 * received or transmitted, or where out-of-order receipt is detected.
196 * The EM code run in a per-CPU worker thread.
198 * To protect against concurrency between a worker thread code and timers,
199 * sequence allocation and deallocation must be locked.
200 * - exchange refcnt can be done atomicly without locks.
201 * - sequence allocation must be locked by exch lock.
202 * - If the EM pool lock and ex_lock must be taken at the same time, then the
203 * EM pool lock must be taken before the ex_lock.
207 * opcode names for debugging.
209 static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;
212 * fc_exch_name_lookup() - Lookup name by opcode
213 * @op: Opcode to be looked up
214 * @table: Opcode/name table
215 * @max_index: Index not to be exceeded
217 * This routine is used to determine a human-readable string identifying
220 static inline const char *fc_exch_name_lookup(unsigned int op, char **table,
221 unsigned int max_index)
223 const char *name = NULL;
233 * fc_exch_rctl_name() - Wrapper routine for fc_exch_name_lookup()
234 * @op: The opcode to be looked up
236 static const char *fc_exch_rctl_name(unsigned int op)
238 return fc_exch_name_lookup(op, fc_exch_rctl_names,
239 ARRAY_SIZE(fc_exch_rctl_names));
243 * fc_exch_hold() - Increment an exchange's reference count
244 * @ep: Echange to be held
246 static inline void fc_exch_hold(struct fc_exch *ep)
248 atomic_inc(&ep->ex_refcnt);
252 * fc_exch_setup_hdr() - Initialize a FC header by initializing some fields
253 * and determine SOF and EOF.
254 * @ep: The exchange to that will use the header
255 * @fp: The frame whose header is to be modified
256 * @f_ctl: F_CTL bits that will be used for the frame header
258 * The fields initialized by this routine are: fh_ox_id, fh_rx_id,
259 * fh_seq_id, fh_seq_cnt and the SOF and EOF.
261 static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,
264 struct fc_frame_header *fh = fc_frame_header_get(fp);
267 fr_sof(fp) = ep->class;
269 fr_sof(fp) = fc_sof_normal(ep->class);
271 if (f_ctl & FC_FC_END_SEQ) {
272 fr_eof(fp) = FC_EOF_T;
273 if (fc_sof_needs_ack(ep->class))
274 fr_eof(fp) = FC_EOF_N;
277 * The number of fill bytes to make the length a 4-byte
278 * multiple is the low order 2-bits of the f_ctl.
279 * The fill itself will have been cleared by the frame
281 * After this, the length will be even, as expected by
284 fill = fr_len(fp) & 3;
287 /* TODO, this may be a problem with fragmented skb */
288 skb_put(fp_skb(fp), fill);
289 hton24(fh->fh_f_ctl, f_ctl | fill);
292 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
293 fr_eof(fp) = FC_EOF_N;
296 /* Initialize remaining fh fields from fc_fill_fc_hdr */
297 fh->fh_ox_id = htons(ep->oxid);
298 fh->fh_rx_id = htons(ep->rxid);
299 fh->fh_seq_id = ep->seq.id;
300 fh->fh_seq_cnt = htons(ep->seq.cnt);
304 * fc_exch_release() - Decrement an exchange's reference count
305 * @ep: Exchange to be released
307 * If the reference count reaches zero and the exchange is complete,
310 static void fc_exch_release(struct fc_exch *ep)
312 struct fc_exch_mgr *mp;
314 if (atomic_dec_and_test(&ep->ex_refcnt)) {
317 ep->destructor(&ep->seq, ep->arg);
318 WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));
319 mempool_free(ep, mp->ep_pool);
324 * fc_exch_timer_cancel() - cancel exch timer
325 * @ep: The exchange whose timer to be canceled
327 static inline void fc_exch_timer_cancel(struct fc_exch *ep)
329 if (cancel_delayed_work(&ep->timeout_work)) {
330 FC_EXCH_DBG(ep, "Exchange timer canceled\n");
331 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
336 * fc_exch_timer_set_locked() - Start a timer for an exchange w/ the
337 * the exchange lock held
338 * @ep: The exchange whose timer will start
339 * @timer_msec: The timeout period
341 * Used for upper level protocols to time out the exchange.
342 * The timer is cancelled when it fires or when the exchange completes.
344 static inline void fc_exch_timer_set_locked(struct fc_exch *ep,
345 unsigned int timer_msec)
347 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
350 FC_EXCH_DBG(ep, "Exchange timer armed : %d msecs\n", timer_msec);
352 fc_exch_hold(ep); /* hold for timer */
353 if (!queue_delayed_work(fc_exch_workqueue, &ep->timeout_work,
354 msecs_to_jiffies(timer_msec))) {
355 FC_EXCH_DBG(ep, "Exchange already queued\n");
361 * fc_exch_timer_set() - Lock the exchange and set the timer
362 * @ep: The exchange whose timer will start
363 * @timer_msec: The timeout period
365 static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec)
367 spin_lock_bh(&ep->ex_lock);
368 fc_exch_timer_set_locked(ep, timer_msec);
369 spin_unlock_bh(&ep->ex_lock);
373 * fc_exch_done_locked() - Complete an exchange with the exchange lock held
374 * @ep: The exchange that is complete
376 * Note: May sleep if invoked from outside a response handler.
378 static int fc_exch_done_locked(struct fc_exch *ep)
383 * We must check for completion in case there are two threads
384 * tyring to complete this. But the rrq code will reuse the
385 * ep, and in that case we only clear the resp and set it as
386 * complete, so it can be reused by the timer to send the rrq.
388 if (ep->state & FC_EX_DONE)
390 ep->esb_stat |= ESB_ST_COMPLETE;
392 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
393 ep->state |= FC_EX_DONE;
394 fc_exch_timer_cancel(ep);
400 static struct fc_exch fc_quarantine_exch;
403 * fc_exch_ptr_get() - Return an exchange from an exchange pool
404 * @pool: Exchange Pool to get an exchange from
405 * @index: Index of the exchange within the pool
407 * Use the index to get an exchange from within an exchange pool. exches
408 * will point to an array of exchange pointers. The index will select
409 * the exchange within the array.
411 static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,
414 struct fc_exch **exches = (struct fc_exch **)(pool + 1);
415 return exches[index];
419 * fc_exch_ptr_set() - Assign an exchange to a slot in an exchange pool
420 * @pool: The pool to assign the exchange to
421 * @index: The index in the pool where the exchange will be assigned
422 * @ep: The exchange to assign to the pool
424 static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
427 ((struct fc_exch **)(pool + 1))[index] = ep;
431 * fc_exch_delete() - Delete an exchange
432 * @ep: The exchange to be deleted
434 static void fc_exch_delete(struct fc_exch *ep)
436 struct fc_exch_pool *pool;
440 spin_lock_bh(&pool->lock);
441 WARN_ON(pool->total_exches <= 0);
442 pool->total_exches--;
444 /* update cache of free slot */
445 index = (ep->xid - ep->em->min_xid) >> fc_cpu_order;
446 if (!(ep->state & FC_EX_QUARANTINE)) {
447 if (pool->left == FC_XID_UNKNOWN)
449 else if (pool->right == FC_XID_UNKNOWN)
452 pool->next_index = index;
453 fc_exch_ptr_set(pool, index, NULL);
455 fc_exch_ptr_set(pool, index, &fc_quarantine_exch);
457 list_del(&ep->ex_list);
458 spin_unlock_bh(&pool->lock);
459 fc_exch_release(ep); /* drop hold for exch in mp */
462 static int fc_seq_send_locked(struct fc_lport *lport, struct fc_seq *sp,
466 struct fc_frame_header *fh = fc_frame_header_get(fp);
469 u8 fh_type = fh->fh_type;
471 ep = fc_seq_exch(sp);
473 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL)) {
478 WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT));
480 f_ctl = ntoh24(fh->fh_f_ctl);
481 fc_exch_setup_hdr(ep, fp, f_ctl);
482 fr_encaps(fp) = ep->encaps;
485 * update sequence count if this frame is carrying
486 * multiple FC frames when sequence offload is enabled
489 if (fr_max_payload(fp))
490 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),
498 error = lport->tt.frame_send(lport, fp);
500 if (fh_type == FC_TYPE_BLS)
504 * Update the exchange and sequence flags,
505 * assuming all frames for the sequence have been sent.
506 * We can only be called to send once for each sequence.
508 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
509 if (f_ctl & FC_FC_SEQ_INIT)
510 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
516 * fc_seq_send() - Send a frame using existing sequence/exchange pair
517 * @lport: The local port that the exchange will be sent on
518 * @sp: The sequence to be sent
519 * @fp: The frame to be sent on the exchange
521 * Note: The frame will be freed either by a direct call to fc_frame_free(fp)
522 * or indirectly by calling libfc_function_template.frame_send().
524 int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp, struct fc_frame *fp)
528 ep = fc_seq_exch(sp);
529 spin_lock_bh(&ep->ex_lock);
530 error = fc_seq_send_locked(lport, sp, fp);
531 spin_unlock_bh(&ep->ex_lock);
534 EXPORT_SYMBOL(fc_seq_send);
537 * fc_seq_alloc() - Allocate a sequence for a given exchange
538 * @ep: The exchange to allocate a new sequence for
539 * @seq_id: The sequence ID to be used
541 * We don't support multiple originated sequences on the same exchange.
542 * By implication, any previously originated sequence on this exchange
543 * is complete, and we reallocate the same sequence.
545 static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
557 * fc_seq_start_next_locked() - Allocate a new sequence on the same
558 * exchange as the supplied sequence
559 * @sp: The sequence/exchange to get a new sequence for
561 static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
563 struct fc_exch *ep = fc_seq_exch(sp);
565 sp = fc_seq_alloc(ep, ep->seq_id++);
566 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
572 * fc_seq_start_next() - Lock the exchange and get a new sequence
573 * for a given sequence/exchange pair
574 * @sp: The sequence/exchange to get a new exchange for
576 struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
578 struct fc_exch *ep = fc_seq_exch(sp);
580 spin_lock_bh(&ep->ex_lock);
581 sp = fc_seq_start_next_locked(sp);
582 spin_unlock_bh(&ep->ex_lock);
586 EXPORT_SYMBOL(fc_seq_start_next);
589 * Set the response handler for the exchange associated with a sequence.
591 * Note: May sleep if invoked from outside a response handler.
593 void fc_seq_set_resp(struct fc_seq *sp,
594 void (*resp)(struct fc_seq *, struct fc_frame *, void *),
597 struct fc_exch *ep = fc_seq_exch(sp);
600 spin_lock_bh(&ep->ex_lock);
601 while (ep->resp_active && ep->resp_task != current) {
602 prepare_to_wait(&ep->resp_wq, &wait, TASK_UNINTERRUPTIBLE);
603 spin_unlock_bh(&ep->ex_lock);
607 spin_lock_bh(&ep->ex_lock);
609 finish_wait(&ep->resp_wq, &wait);
612 spin_unlock_bh(&ep->ex_lock);
614 EXPORT_SYMBOL(fc_seq_set_resp);
617 * fc_exch_abort_locked() - Abort an exchange
618 * @ep: The exchange to be aborted
619 * @timer_msec: The period of time to wait before aborting
621 * Abort an exchange and sequence. Generally called because of a
622 * exchange timeout or an abort from the upper layer.
624 * A timer_msec can be specified for abort timeout, if non-zero
625 * timer_msec value is specified then exchange resp handler
626 * will be called with timeout error if no response to abort.
628 * Locking notes: Called with exch lock held
630 * Return value: 0 on success else error code
632 static int fc_exch_abort_locked(struct fc_exch *ep,
633 unsigned int timer_msec)
639 FC_EXCH_DBG(ep, "exch: abort, time %d msecs\n", timer_msec);
640 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
641 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
642 FC_EXCH_DBG(ep, "exch: already completed esb %x state %x\n",
643 ep->esb_stat, ep->state);
648 * Send the abort on a new sequence if possible.
650 sp = fc_seq_start_next_locked(&ep->seq);
655 fc_exch_timer_set_locked(ep, timer_msec);
659 * Send an abort for the sequence that timed out.
661 fp = fc_frame_alloc(ep->lp, 0);
663 ep->esb_stat |= ESB_ST_SEQ_INIT;
664 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
665 FC_TYPE_BLS, FC_FC_END_SEQ |
667 error = fc_seq_send_locked(ep->lp, sp, fp);
673 * If not logged into the fabric, don't send ABTS but leave
674 * sequence active until next timeout.
678 ep->esb_stat |= ESB_ST_ABNORMAL;
683 * fc_seq_exch_abort() - Abort an exchange and sequence
684 * @req_sp: The sequence to be aborted
685 * @timer_msec: The period of time to wait before aborting
687 * Generally called because of a timeout or an abort from the upper layer.
689 * Return value: 0 on success else error code
691 int fc_seq_exch_abort(const struct fc_seq *req_sp, unsigned int timer_msec)
696 ep = fc_seq_exch(req_sp);
697 spin_lock_bh(&ep->ex_lock);
698 error = fc_exch_abort_locked(ep, timer_msec);
699 spin_unlock_bh(&ep->ex_lock);
704 * fc_invoke_resp() - invoke ep->resp()
707 * It is assumed that after initialization finished (this means the
708 * first unlock of ex_lock after fc_exch_alloc()) ep->resp and ep->arg are
709 * modified only via fc_seq_set_resp(). This guarantees that none of these
710 * two variables changes if ep->resp_active > 0.
712 * If an fc_seq_set_resp() call is busy modifying ep->resp and ep->arg when
713 * this function is invoked, the first spin_lock_bh() call in this function
714 * will wait until fc_seq_set_resp() has finished modifying these variables.
716 * Since fc_exch_done() invokes fc_seq_set_resp() it is guaranteed that that
717 * ep->resp() won't be invoked after fc_exch_done() has returned.
719 * The response handler itself may invoke fc_exch_done(), which will clear the
723 * Returns true if and only if ep->resp has been invoked.
725 static bool fc_invoke_resp(struct fc_exch *ep, struct fc_seq *sp,
728 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
732 spin_lock_bh(&ep->ex_lock);
734 if (ep->resp_task != current)
735 ep->resp_task = !ep->resp_task ? current : NULL;
738 spin_unlock_bh(&ep->ex_lock);
745 spin_lock_bh(&ep->ex_lock);
746 if (--ep->resp_active == 0)
747 ep->resp_task = NULL;
748 spin_unlock_bh(&ep->ex_lock);
750 if (ep->resp_active == 0)
751 wake_up(&ep->resp_wq);
757 * fc_exch_timeout() - Handle exchange timer expiration
758 * @work: The work_struct identifying the exchange that timed out
760 static void fc_exch_timeout(struct work_struct *work)
762 struct fc_exch *ep = container_of(work, struct fc_exch,
764 struct fc_seq *sp = &ep->seq;
768 FC_EXCH_DBG(ep, "Exchange timed out state %x\n", ep->state);
770 spin_lock_bh(&ep->ex_lock);
771 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
774 e_stat = ep->esb_stat;
775 if (e_stat & ESB_ST_COMPLETE) {
776 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
777 spin_unlock_bh(&ep->ex_lock);
778 if (e_stat & ESB_ST_REC_QUAL)
782 if (e_stat & ESB_ST_ABNORMAL)
783 rc = fc_exch_done_locked(ep);
784 spin_unlock_bh(&ep->ex_lock);
787 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_TIMEOUT));
788 fc_seq_set_resp(sp, NULL, ep->arg);
789 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
793 spin_unlock_bh(&ep->ex_lock);
796 * This release matches the hold taken when the timer was set.
802 * fc_exch_em_alloc() - Allocate an exchange from a specified EM.
803 * @lport: The local port that the exchange is for
804 * @mp: The exchange manager that will allocate the exchange
806 * Returns pointer to allocated fc_exch with exch lock held.
808 static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
809 struct fc_exch_mgr *mp)
814 struct fc_exch_pool *pool;
816 /* allocate memory for exchange */
817 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);
819 atomic_inc(&mp->stats.no_free_exch);
822 memset(ep, 0, sizeof(*ep));
825 pool = per_cpu_ptr(mp->pool, cpu);
826 spin_lock_bh(&pool->lock);
829 /* peek cache of free slot */
830 if (pool->left != FC_XID_UNKNOWN) {
831 if (!WARN_ON(fc_exch_ptr_get(pool, pool->left))) {
833 pool->left = FC_XID_UNKNOWN;
837 if (pool->right != FC_XID_UNKNOWN) {
838 if (!WARN_ON(fc_exch_ptr_get(pool, pool->right))) {
840 pool->right = FC_XID_UNKNOWN;
845 index = pool->next_index;
846 /* allocate new exch from pool */
847 while (fc_exch_ptr_get(pool, index)) {
848 index = index == mp->pool_max_index ? 0 : index + 1;
849 if (index == pool->next_index)
852 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
854 fc_exch_hold(ep); /* hold for exch in mp */
855 spin_lock_init(&ep->ex_lock);
857 * Hold exch lock for caller to prevent fc_exch_reset()
858 * from releasing exch while fc_exch_alloc() caller is
859 * still working on exch.
861 spin_lock_bh(&ep->ex_lock);
863 fc_exch_ptr_set(pool, index, ep);
864 list_add_tail(&ep->ex_list, &pool->ex_list);
865 fc_seq_alloc(ep, ep->seq_id++);
866 pool->total_exches++;
867 spin_unlock_bh(&pool->lock);
872 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
876 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
877 ep->rxid = FC_XID_UNKNOWN;
878 ep->class = mp->class;
880 init_waitqueue_head(&ep->resp_wq);
881 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
885 spin_unlock_bh(&pool->lock);
886 atomic_inc(&mp->stats.no_free_exch_xid);
887 mempool_free(ep, mp->ep_pool);
892 * fc_exch_alloc() - Allocate an exchange from an EM on a
893 * local port's list of EMs.
894 * @lport: The local port that will own the exchange
895 * @fp: The FC frame that the exchange will be for
897 * This function walks the list of exchange manager(EM)
898 * anchors to select an EM for a new exchange allocation. The
899 * EM is selected when a NULL match function pointer is encountered
900 * or when a call to a match function returns true.
902 static struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
905 struct fc_exch_mgr_anchor *ema;
908 list_for_each_entry(ema, &lport->ema_list, ema_list) {
909 if (!ema->match || ema->match(fp)) {
910 ep = fc_exch_em_alloc(lport, ema->mp);
919 * fc_exch_find() - Lookup and hold an exchange
920 * @mp: The exchange manager to lookup the exchange from
921 * @xid: The XID of the exchange to look up
923 static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
925 struct fc_lport *lport = mp->lport;
926 struct fc_exch_pool *pool;
927 struct fc_exch *ep = NULL;
928 u16 cpu = xid & fc_cpu_mask;
930 if (xid == FC_XID_UNKNOWN)
933 if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
934 pr_err("host%u: lport %6.6x: xid %d invalid CPU %d\n:",
935 lport->host->host_no, lport->port_id, xid, cpu);
939 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
940 pool = per_cpu_ptr(mp->pool, cpu);
941 spin_lock_bh(&pool->lock);
942 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
943 if (ep == &fc_quarantine_exch) {
944 FC_LPORT_DBG(lport, "xid %x quarantined\n", xid);
948 WARN_ON(ep->xid != xid);
951 spin_unlock_bh(&pool->lock);
958 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and
959 * the memory allocated for the related objects may be freed.
960 * @sp: The sequence that has completed
962 * Note: May sleep if invoked from outside a response handler.
964 void fc_exch_done(struct fc_seq *sp)
966 struct fc_exch *ep = fc_seq_exch(sp);
969 spin_lock_bh(&ep->ex_lock);
970 rc = fc_exch_done_locked(ep);
971 spin_unlock_bh(&ep->ex_lock);
973 fc_seq_set_resp(sp, NULL, ep->arg);
977 EXPORT_SYMBOL(fc_exch_done);
980 * fc_exch_resp() - Allocate a new exchange for a response frame
981 * @lport: The local port that the exchange was for
982 * @mp: The exchange manager to allocate the exchange from
983 * @fp: The response frame
985 * Sets the responder ID in the frame header.
987 static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
988 struct fc_exch_mgr *mp,
992 struct fc_frame_header *fh;
994 ep = fc_exch_alloc(lport, fp);
996 ep->class = fc_frame_class(fp);
999 * Set EX_CTX indicating we're responding on this exchange.
1001 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
1002 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
1003 fh = fc_frame_header_get(fp);
1004 ep->sid = ntoh24(fh->fh_d_id);
1005 ep->did = ntoh24(fh->fh_s_id);
1009 * Allocated exchange has placed the XID in the
1010 * originator field. Move it to the responder field,
1011 * and set the originator XID from the frame.
1014 ep->oxid = ntohs(fh->fh_ox_id);
1015 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
1016 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
1017 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
1019 fc_exch_hold(ep); /* hold for caller */
1020 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
1026 * fc_seq_lookup_recip() - Find a sequence where the other end
1027 * originated the sequence
1028 * @lport: The local port that the frame was sent to
1029 * @mp: The Exchange Manager to lookup the exchange from
1030 * @fp: The frame associated with the sequence we're looking for
1032 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
1033 * on the ep that should be released by the caller.
1035 static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
1036 struct fc_exch_mgr *mp,
1037 struct fc_frame *fp)
1039 struct fc_frame_header *fh = fc_frame_header_get(fp);
1040 struct fc_exch *ep = NULL;
1041 struct fc_seq *sp = NULL;
1042 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
1046 f_ctl = ntoh24(fh->fh_f_ctl);
1047 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
1050 * Lookup or create the exchange if we will be creating the sequence.
1052 if (f_ctl & FC_FC_EX_CTX) {
1053 xid = ntohs(fh->fh_ox_id); /* we originated exch */
1054 ep = fc_exch_find(mp, xid);
1056 atomic_inc(&mp->stats.xid_not_found);
1057 reject = FC_RJT_OX_ID;
1060 if (ep->rxid == FC_XID_UNKNOWN)
1061 ep->rxid = ntohs(fh->fh_rx_id);
1062 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
1063 reject = FC_RJT_OX_ID;
1067 xid = ntohs(fh->fh_rx_id); /* we are the responder */
1070 * Special case for MDS issuing an ELS TEST with a
1072 * XXX take this out once we do the proper reject.
1074 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
1075 fc_frame_payload_op(fp) == ELS_TEST) {
1076 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
1077 xid = FC_XID_UNKNOWN;
1081 * new sequence - find the exchange
1083 ep = fc_exch_find(mp, xid);
1084 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
1086 atomic_inc(&mp->stats.xid_busy);
1087 reject = FC_RJT_RX_ID;
1090 ep = fc_exch_resp(lport, mp, fp);
1092 reject = FC_RJT_EXCH_EST; /* XXX */
1095 xid = ep->xid; /* get our XID */
1097 atomic_inc(&mp->stats.xid_not_found);
1098 reject = FC_RJT_RX_ID; /* XID not found */
1103 spin_lock_bh(&ep->ex_lock);
1105 * At this point, we have the exchange held.
1106 * Find or create the sequence.
1108 if (fc_sof_is_init(fr_sof(fp))) {
1110 sp->ssb_stat |= SSB_ST_RESP;
1111 sp->id = fh->fh_seq_id;
1114 if (sp->id != fh->fh_seq_id) {
1115 atomic_inc(&mp->stats.seq_not_found);
1116 if (f_ctl & FC_FC_END_SEQ) {
1118 * Update sequence_id based on incoming last
1119 * frame of sequence exchange. This is needed
1120 * for FC target where DDP has been used
1121 * on target where, stack is indicated only
1122 * about last frame's (payload _header) header.
1123 * Whereas "seq_id" which is part of
1124 * frame_header is allocated by initiator
1125 * which is totally different from "seq_id"
1126 * allocated when XFER_RDY was sent by target.
1127 * To avoid false -ve which results into not
1128 * sending RSP, hence write request on other
1129 * end never finishes.
1131 sp->ssb_stat |= SSB_ST_RESP;
1132 sp->id = fh->fh_seq_id;
1134 spin_unlock_bh(&ep->ex_lock);
1136 /* sequence/exch should exist */
1137 reject = FC_RJT_SEQ_ID;
1142 WARN_ON(ep != fc_seq_exch(sp));
1144 if (f_ctl & FC_FC_SEQ_INIT)
1145 ep->esb_stat |= ESB_ST_SEQ_INIT;
1146 spin_unlock_bh(&ep->ex_lock);
1152 fc_exch_done(&ep->seq);
1153 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
1158 * fc_seq_lookup_orig() - Find a sequence where this end
1159 * originated the sequence
1160 * @mp: The Exchange Manager to lookup the exchange from
1161 * @fp: The frame associated with the sequence we're looking for
1163 * Does not hold the sequence for the caller.
1165 static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
1166 struct fc_frame *fp)
1168 struct fc_frame_header *fh = fc_frame_header_get(fp);
1170 struct fc_seq *sp = NULL;
1174 f_ctl = ntoh24(fh->fh_f_ctl);
1175 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
1176 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
1177 ep = fc_exch_find(mp, xid);
1180 if (ep->seq.id == fh->fh_seq_id) {
1182 * Save the RX_ID if we didn't previously know it.
1185 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
1186 ep->rxid == FC_XID_UNKNOWN) {
1187 ep->rxid = ntohs(fh->fh_rx_id);
1190 fc_exch_release(ep);
1195 * fc_exch_set_addr() - Set the source and destination IDs for an exchange
1196 * @ep: The exchange to set the addresses for
1197 * @orig_id: The originator's ID
1198 * @resp_id: The responder's ID
1200 * Note this must be done before the first sequence of the exchange is sent.
1202 static void fc_exch_set_addr(struct fc_exch *ep,
1203 u32 orig_id, u32 resp_id)
1206 if (ep->esb_stat & ESB_ST_RESP) {
1216 * fc_seq_els_rsp_send() - Send an ELS response using information from
1217 * the existing sequence/exchange.
1218 * @fp: The received frame
1219 * @els_cmd: The ELS command to be sent
1220 * @els_data: The ELS data to be sent
1222 * The received frame is not freed.
1224 void fc_seq_els_rsp_send(struct fc_frame *fp, enum fc_els_cmd els_cmd,
1225 struct fc_seq_els_data *els_data)
1229 fc_seq_ls_rjt(fp, els_data->reason, els_data->explan);
1235 fc_exch_els_rrq(fp);
1238 fc_exch_els_rec(fp);
1241 FC_LPORT_DBG(fr_dev(fp), "Invalid ELS CMD:%x\n", els_cmd);
1244 EXPORT_SYMBOL_GPL(fc_seq_els_rsp_send);
1247 * fc_seq_send_last() - Send a sequence that is the last in the exchange
1248 * @sp: The sequence that is to be sent
1249 * @fp: The frame that will be sent on the sequence
1250 * @rctl: The R_CTL information to be sent
1251 * @fh_type: The frame header type
1253 static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
1254 enum fc_rctl rctl, enum fc_fh_type fh_type)
1257 struct fc_exch *ep = fc_seq_exch(sp);
1259 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
1261 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
1262 fc_seq_send_locked(ep->lp, sp, fp);
1266 * fc_seq_send_ack() - Send an acknowledgement that we've received a frame
1267 * @sp: The sequence to send the ACK on
1268 * @rx_fp: The received frame that is being acknoledged
1270 * Send ACK_1 (or equiv.) indicating we received something.
1272 static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
1274 struct fc_frame *fp;
1275 struct fc_frame_header *rx_fh;
1276 struct fc_frame_header *fh;
1277 struct fc_exch *ep = fc_seq_exch(sp);
1278 struct fc_lport *lport = ep->lp;
1282 * Don't send ACKs for class 3.
1284 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
1285 fp = fc_frame_alloc(lport, 0);
1287 FC_EXCH_DBG(ep, "Drop ACK request, out of memory\n");
1291 fh = fc_frame_header_get(fp);
1292 fh->fh_r_ctl = FC_RCTL_ACK_1;
1293 fh->fh_type = FC_TYPE_BLS;
1296 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1297 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1298 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1299 * Last ACK uses bits 7-6 (continue sequence),
1300 * bits 5-4 are meaningful (what kind of ACK to use).
1302 rx_fh = fc_frame_header_get(rx_fp);
1303 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1304 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1305 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
1306 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
1307 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1308 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1309 hton24(fh->fh_f_ctl, f_ctl);
1311 fc_exch_setup_hdr(ep, fp, f_ctl);
1312 fh->fh_seq_id = rx_fh->fh_seq_id;
1313 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1314 fh->fh_parm_offset = htonl(1); /* ack single frame */
1316 fr_sof(fp) = fr_sof(rx_fp);
1317 if (f_ctl & FC_FC_END_SEQ)
1318 fr_eof(fp) = FC_EOF_T;
1320 fr_eof(fp) = FC_EOF_N;
1322 lport->tt.frame_send(lport, fp);
1327 * fc_exch_send_ba_rjt() - Send BLS Reject
1328 * @rx_fp: The frame being rejected
1329 * @reason: The reason the frame is being rejected
1330 * @explan: The explanation for the rejection
1332 * This is for rejecting BA_ABTS only.
1334 static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
1335 enum fc_ba_rjt_reason reason,
1336 enum fc_ba_rjt_explan explan)
1338 struct fc_frame *fp;
1339 struct fc_frame_header *rx_fh;
1340 struct fc_frame_header *fh;
1341 struct fc_ba_rjt *rp;
1343 struct fc_lport *lport;
1346 lport = fr_dev(rx_fp);
1348 fp = fc_frame_alloc(lport, sizeof(*rp));
1350 FC_EXCH_DBG(fc_seq_exch(sp),
1351 "Drop BA_RJT request, out of memory\n");
1354 fh = fc_frame_header_get(fp);
1355 rx_fh = fc_frame_header_get(rx_fp);
1357 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1359 rp = fc_frame_payload_get(fp, sizeof(*rp));
1360 rp->br_reason = reason;
1361 rp->br_explan = explan;
1364 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1366 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1367 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1368 fh->fh_ox_id = rx_fh->fh_ox_id;
1369 fh->fh_rx_id = rx_fh->fh_rx_id;
1370 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1371 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1372 fh->fh_type = FC_TYPE_BLS;
1375 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1376 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1377 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1378 * Last ACK uses bits 7-6 (continue sequence),
1379 * bits 5-4 are meaningful (what kind of ACK to use).
1380 * Always set LAST_SEQ, END_SEQ.
1382 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1383 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1384 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1385 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1386 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1387 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1388 f_ctl &= ~FC_FC_FIRST_SEQ;
1389 hton24(fh->fh_f_ctl, f_ctl);
1391 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1392 fr_eof(fp) = FC_EOF_T;
1393 if (fc_sof_needs_ack(fr_sof(fp)))
1394 fr_eof(fp) = FC_EOF_N;
1396 lport->tt.frame_send(lport, fp);
1400 * fc_exch_recv_abts() - Handle an incoming ABTS
1401 * @ep: The exchange the abort was on
1402 * @rx_fp: The ABTS frame
1404 * This would be for target mode usually, but could be due to lost
1405 * FCP transfer ready, confirm or RRQ. We always handle this as an
1406 * exchange abort, ignoring the parameter.
1408 static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1410 struct fc_frame *fp;
1411 struct fc_ba_acc *ap;
1412 struct fc_frame_header *fh;
1418 FC_EXCH_DBG(ep, "exch: ABTS received\n");
1419 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1421 FC_EXCH_DBG(ep, "Drop ABTS request, out of memory\n");
1425 spin_lock_bh(&ep->ex_lock);
1426 if (ep->esb_stat & ESB_ST_COMPLETE) {
1427 spin_unlock_bh(&ep->ex_lock);
1428 FC_EXCH_DBG(ep, "exch: ABTS rejected, exchange complete\n");
1432 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
1433 ep->esb_stat |= ESB_ST_REC_QUAL;
1434 fc_exch_hold(ep); /* hold for REC_QUAL */
1436 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1437 fh = fc_frame_header_get(fp);
1438 ap = fc_frame_payload_get(fp, sizeof(*ap));
1439 memset(ap, 0, sizeof(*ap));
1441 ap->ba_high_seq_cnt = htons(0xffff);
1442 if (sp->ssb_stat & SSB_ST_RESP) {
1443 ap->ba_seq_id = sp->id;
1444 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1445 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1446 ap->ba_low_seq_cnt = htons(sp->cnt);
1448 sp = fc_seq_start_next_locked(sp);
1449 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1450 ep->esb_stat |= ESB_ST_ABNORMAL;
1451 spin_unlock_bh(&ep->ex_lock);
1454 fc_frame_free(rx_fp);
1458 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1463 * fc_seq_assign() - Assign exchange and sequence for incoming request
1464 * @lport: The local port that received the request
1465 * @fp: The request frame
1467 * On success, the sequence pointer will be returned and also in fr_seq(@fp).
1468 * A reference will be held on the exchange/sequence for the caller, which
1469 * must call fc_seq_release().
1471 struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)
1473 struct fc_exch_mgr_anchor *ema;
1475 WARN_ON(lport != fr_dev(fp));
1476 WARN_ON(fr_seq(fp));
1479 list_for_each_entry(ema, &lport->ema_list, ema_list)
1480 if ((!ema->match || ema->match(fp)) &&
1481 fc_seq_lookup_recip(lport, ema->mp, fp) == FC_RJT_NONE)
1485 EXPORT_SYMBOL(fc_seq_assign);
1488 * fc_seq_release() - Release the hold
1489 * @sp: The sequence.
1491 void fc_seq_release(struct fc_seq *sp)
1493 fc_exch_release(fc_seq_exch(sp));
1495 EXPORT_SYMBOL(fc_seq_release);
1498 * fc_exch_recv_req() - Handler for an incoming request
1499 * @lport: The local port that received the request
1500 * @mp: The EM that the exchange is on
1501 * @fp: The request frame
1503 * This is used when the other end is originating the exchange
1506 static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp,
1507 struct fc_frame *fp)
1509 struct fc_frame_header *fh = fc_frame_header_get(fp);
1510 struct fc_seq *sp = NULL;
1511 struct fc_exch *ep = NULL;
1512 enum fc_pf_rjt_reason reject;
1514 /* We can have the wrong fc_lport at this point with NPIV, which is a
1515 * problem now that we know a new exchange needs to be allocated
1517 lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id));
1524 BUG_ON(fr_seq(fp)); /* XXX remove later */
1527 * If the RX_ID is 0xffff, don't allocate an exchange.
1528 * The upper-level protocol may request one later, if needed.
1530 if (fh->fh_rx_id == htons(FC_XID_UNKNOWN))
1531 return fc_lport_recv(lport, fp);
1533 reject = fc_seq_lookup_recip(lport, mp, fp);
1534 if (reject == FC_RJT_NONE) {
1535 sp = fr_seq(fp); /* sequence will be held */
1536 ep = fc_seq_exch(sp);
1537 fc_seq_send_ack(sp, fp);
1538 ep->encaps = fr_encaps(fp);
1541 * Call the receive function.
1543 * The receive function may allocate a new sequence
1544 * over the old one, so we shouldn't change the
1545 * sequence after this.
1547 * The frame will be freed by the receive function.
1548 * If new exch resp handler is valid then call that
1551 if (!fc_invoke_resp(ep, sp, fp))
1552 fc_lport_recv(lport, fp);
1553 fc_exch_release(ep); /* release from lookup */
1555 FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n",
1562 * fc_exch_recv_seq_resp() - Handler for an incoming response where the other
1563 * end is the originator of the sequence that is a
1564 * response to our initial exchange
1565 * @mp: The EM that the exchange is on
1566 * @fp: The response frame
1568 static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1570 struct fc_frame_header *fh = fc_frame_header_get(fp);
1577 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1579 atomic_inc(&mp->stats.xid_not_found);
1582 if (ep->esb_stat & ESB_ST_COMPLETE) {
1583 atomic_inc(&mp->stats.xid_not_found);
1586 if (ep->rxid == FC_XID_UNKNOWN)
1587 ep->rxid = ntohs(fh->fh_rx_id);
1588 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1589 atomic_inc(&mp->stats.xid_not_found);
1592 if (ep->did != ntoh24(fh->fh_s_id) &&
1593 ep->did != FC_FID_FLOGI) {
1594 atomic_inc(&mp->stats.xid_not_found);
1599 if (fc_sof_is_init(sof)) {
1600 sp->ssb_stat |= SSB_ST_RESP;
1601 sp->id = fh->fh_seq_id;
1604 f_ctl = ntoh24(fh->fh_f_ctl);
1607 spin_lock_bh(&ep->ex_lock);
1608 if (f_ctl & FC_FC_SEQ_INIT)
1609 ep->esb_stat |= ESB_ST_SEQ_INIT;
1610 spin_unlock_bh(&ep->ex_lock);
1612 if (fc_sof_needs_ack(sof))
1613 fc_seq_send_ack(sp, fp);
1615 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1616 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1617 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1618 spin_lock_bh(&ep->ex_lock);
1619 rc = fc_exch_done_locked(ep);
1620 WARN_ON(fc_seq_exch(sp) != ep);
1621 spin_unlock_bh(&ep->ex_lock);
1625 FC_EXCH_DBG(ep, "ep is completed already,"
1626 "hence skip calling the resp\n");
1632 * Call the receive function.
1633 * The sequence is held (has a refcnt) for us,
1634 * but not for the receive function.
1636 * The receive function may allocate a new sequence
1637 * over the old one, so we shouldn't change the
1638 * sequence after this.
1640 * The frame will be freed by the receive function.
1641 * If new exch resp handler is valid then call that
1644 if (!fc_invoke_resp(ep, sp, fp))
1648 fc_exch_release(ep);
1651 fc_exch_release(ep);
1657 * fc_exch_recv_resp() - Handler for a sequence where other end is
1658 * responding to our sequence
1659 * @mp: The EM that the exchange is on
1660 * @fp: The response frame
1662 static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1666 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1669 atomic_inc(&mp->stats.xid_not_found);
1671 atomic_inc(&mp->stats.non_bls_resp);
1677 * fc_exch_abts_resp() - Handler for a response to an ABT
1678 * @ep: The exchange that the frame is on
1679 * @fp: The response frame
1681 * This response would be to an ABTS cancelling an exchange or sequence.
1682 * The response can be either BA_ACC or BA_RJT
1684 static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1686 struct fc_frame_header *fh;
1687 struct fc_ba_acc *ap;
1691 int rc = 1, has_rec = 0;
1693 fh = fc_frame_header_get(fp);
1694 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1695 fc_exch_rctl_name(fh->fh_r_ctl));
1697 if (cancel_delayed_work_sync(&ep->timeout_work)) {
1698 FC_EXCH_DBG(ep, "Exchange timer canceled due to ABTS response\n");
1699 fc_exch_release(ep); /* release from pending timer hold */
1703 spin_lock_bh(&ep->ex_lock);
1704 switch (fh->fh_r_ctl) {
1705 case FC_RCTL_BA_ACC:
1706 ap = fc_frame_payload_get(fp, sizeof(*ap));
1711 * Decide whether to establish a Recovery Qualifier.
1712 * We do this if there is a non-empty SEQ_CNT range and
1713 * SEQ_ID is the same as the one we aborted.
1715 low = ntohs(ap->ba_low_seq_cnt);
1716 high = ntohs(ap->ba_high_seq_cnt);
1717 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1718 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1719 ap->ba_seq_id == ep->seq_id) && low != high) {
1720 ep->esb_stat |= ESB_ST_REC_QUAL;
1721 fc_exch_hold(ep); /* hold for recovery qualifier */
1725 case FC_RCTL_BA_RJT:
1731 /* do we need to do some other checks here. Can we reuse more of
1732 * fc_exch_recv_seq_resp
1736 * do we want to check END_SEQ as well as LAST_SEQ here?
1738 if (ep->fh_type != FC_TYPE_FCP &&
1739 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1740 rc = fc_exch_done_locked(ep);
1741 spin_unlock_bh(&ep->ex_lock);
1746 if (!fc_invoke_resp(ep, sp, fp))
1749 fc_exch_timer_set(ep, ep->r_a_tov);
1750 fc_exch_release(ep);
1754 * fc_exch_recv_bls() - Handler for a BLS sequence
1755 * @mp: The EM that the exchange is on
1756 * @fp: The request frame
1758 * The BLS frame is always a sequence initiated by the remote side.
1759 * We may be either the originator or recipient of the exchange.
1761 static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1763 struct fc_frame_header *fh;
1767 fh = fc_frame_header_get(fp);
1768 f_ctl = ntoh24(fh->fh_f_ctl);
1771 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1772 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1773 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1774 spin_lock_bh(&ep->ex_lock);
1775 ep->esb_stat |= ESB_ST_SEQ_INIT;
1776 spin_unlock_bh(&ep->ex_lock);
1778 if (f_ctl & FC_FC_SEQ_CTX) {
1780 * A response to a sequence we initiated.
1781 * This should only be ACKs for class 2 or F.
1783 switch (fh->fh_r_ctl) {
1789 FC_EXCH_DBG(ep, "BLS rctl %x - %s received\n",
1791 fc_exch_rctl_name(fh->fh_r_ctl));
1796 switch (fh->fh_r_ctl) {
1797 case FC_RCTL_BA_RJT:
1798 case FC_RCTL_BA_ACC:
1800 fc_exch_abts_resp(ep, fp);
1804 case FC_RCTL_BA_ABTS:
1806 fc_exch_recv_abts(ep, fp);
1810 default: /* ignore junk */
1816 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1820 * fc_seq_ls_acc() - Accept sequence with LS_ACC
1821 * @rx_fp: The received frame, not freed here.
1823 * If this fails due to allocation or transmit congestion, assume the
1824 * originator will repeat the sequence.
1826 static void fc_seq_ls_acc(struct fc_frame *rx_fp)
1828 struct fc_lport *lport;
1829 struct fc_els_ls_acc *acc;
1830 struct fc_frame *fp;
1833 lport = fr_dev(rx_fp);
1835 fp = fc_frame_alloc(lport, sizeof(*acc));
1837 FC_EXCH_DBG(fc_seq_exch(sp),
1838 "exch: drop LS_ACC, out of memory\n");
1841 acc = fc_frame_payload_get(fp, sizeof(*acc));
1842 memset(acc, 0, sizeof(*acc));
1843 acc->la_cmd = ELS_LS_ACC;
1844 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1845 lport->tt.frame_send(lport, fp);
1849 * fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT
1850 * @rx_fp: The received frame, not freed here.
1851 * @reason: The reason the sequence is being rejected
1852 * @explan: The explanation for the rejection
1854 * If this fails due to allocation or transmit congestion, assume the
1855 * originator will repeat the sequence.
1857 static void fc_seq_ls_rjt(struct fc_frame *rx_fp, enum fc_els_rjt_reason reason,
1858 enum fc_els_rjt_explan explan)
1860 struct fc_lport *lport;
1861 struct fc_els_ls_rjt *rjt;
1862 struct fc_frame *fp;
1865 lport = fr_dev(rx_fp);
1867 fp = fc_frame_alloc(lport, sizeof(*rjt));
1869 FC_EXCH_DBG(fc_seq_exch(sp),
1870 "exch: drop LS_ACC, out of memory\n");
1873 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1874 memset(rjt, 0, sizeof(*rjt));
1875 rjt->er_cmd = ELS_LS_RJT;
1876 rjt->er_reason = reason;
1877 rjt->er_explan = explan;
1878 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1879 lport->tt.frame_send(lport, fp);
1883 * fc_exch_reset() - Reset an exchange
1884 * @ep: The exchange to be reset
1886 * Note: May sleep if invoked from outside a response handler.
1888 static void fc_exch_reset(struct fc_exch *ep)
1893 spin_lock_bh(&ep->ex_lock);
1894 ep->state |= FC_EX_RST_CLEANUP;
1895 fc_exch_timer_cancel(ep);
1896 if (ep->esb_stat & ESB_ST_REC_QUAL)
1897 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1898 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1900 rc = fc_exch_done_locked(ep);
1901 spin_unlock_bh(&ep->ex_lock);
1908 FC_EXCH_DBG(ep, "ep is completed already,"
1909 "hence skip calling the resp\n");
1913 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_CLOSED));
1915 fc_seq_set_resp(sp, NULL, ep->arg);
1916 fc_exch_release(ep);
1920 * fc_exch_pool_reset() - Reset a per cpu exchange pool
1921 * @lport: The local port that the exchange pool is on
1922 * @pool: The exchange pool to be reset
1923 * @sid: The source ID
1924 * @did: The destination ID
1926 * Resets a per cpu exches pool, releasing all of its sequences
1927 * and exchanges. If sid is non-zero then reset only exchanges
1928 * we sourced from the local port's FID. If did is non-zero then
1929 * only reset exchanges destined for the local port's FID.
1931 static void fc_exch_pool_reset(struct fc_lport *lport,
1932 struct fc_exch_pool *pool,
1936 struct fc_exch *next;
1938 spin_lock_bh(&pool->lock);
1940 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1941 if ((lport == ep->lp) &&
1942 (sid == 0 || sid == ep->sid) &&
1943 (did == 0 || did == ep->did)) {
1945 spin_unlock_bh(&pool->lock);
1949 fc_exch_release(ep);
1950 spin_lock_bh(&pool->lock);
1953 * must restart loop incase while lock
1954 * was down multiple eps were released.
1959 pool->next_index = 0;
1960 pool->left = FC_XID_UNKNOWN;
1961 pool->right = FC_XID_UNKNOWN;
1962 spin_unlock_bh(&pool->lock);
1966 * fc_exch_mgr_reset() - Reset all EMs of a local port
1967 * @lport: The local port whose EMs are to be reset
1968 * @sid: The source ID
1969 * @did: The destination ID
1971 * Reset all EMs associated with a given local port. Release all
1972 * sequences and exchanges. If sid is non-zero then reset only the
1973 * exchanges sent from the local port's FID. If did is non-zero then
1974 * reset only exchanges destined for the local port's FID.
1976 void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1978 struct fc_exch_mgr_anchor *ema;
1981 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1982 for_each_possible_cpu(cpu)
1983 fc_exch_pool_reset(lport,
1984 per_cpu_ptr(ema->mp->pool, cpu),
1988 EXPORT_SYMBOL(fc_exch_mgr_reset);
1991 * fc_exch_lookup() - find an exchange
1992 * @lport: The local port
1993 * @xid: The exchange ID
1995 * Returns exchange pointer with hold for caller, or NULL if not found.
1997 static struct fc_exch *fc_exch_lookup(struct fc_lport *lport, u32 xid)
1999 struct fc_exch_mgr_anchor *ema;
2001 list_for_each_entry(ema, &lport->ema_list, ema_list)
2002 if (ema->mp->min_xid <= xid && xid <= ema->mp->max_xid)
2003 return fc_exch_find(ema->mp, xid);
2008 * fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests
2009 * @rfp: The REC frame, not freed here.
2011 * Note that the requesting port may be different than the S_ID in the request.
2013 static void fc_exch_els_rec(struct fc_frame *rfp)
2015 struct fc_lport *lport;
2016 struct fc_frame *fp;
2018 struct fc_els_rec *rp;
2019 struct fc_els_rec_acc *acc;
2020 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
2021 enum fc_els_rjt_explan explan;
2023 u16 xid, rxid, oxid;
2025 lport = fr_dev(rfp);
2026 rp = fc_frame_payload_get(rfp, sizeof(*rp));
2027 explan = ELS_EXPL_INV_LEN;
2030 sid = ntoh24(rp->rec_s_id);
2031 rxid = ntohs(rp->rec_rx_id);
2032 oxid = ntohs(rp->rec_ox_id);
2034 explan = ELS_EXPL_OXID_RXID;
2035 if (sid == fc_host_port_id(lport->host))
2039 if (xid == FC_XID_UNKNOWN) {
2041 "REC request from %x: invalid rxid %x oxid %x\n",
2045 ep = fc_exch_lookup(lport, xid);
2048 "REC request from %x: rxid %x oxid %x not found\n",
2052 FC_EXCH_DBG(ep, "REC request from %x: rxid %x oxid %x\n",
2054 if (ep->oid != sid || oxid != ep->oxid)
2056 if (rxid != FC_XID_UNKNOWN && rxid != ep->rxid)
2058 fp = fc_frame_alloc(lport, sizeof(*acc));
2060 FC_EXCH_DBG(ep, "Drop REC request, out of memory\n");
2064 acc = fc_frame_payload_get(fp, sizeof(*acc));
2065 memset(acc, 0, sizeof(*acc));
2066 acc->reca_cmd = ELS_LS_ACC;
2067 acc->reca_ox_id = rp->rec_ox_id;
2068 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
2069 acc->reca_rx_id = htons(ep->rxid);
2070 if (ep->sid == ep->oid)
2071 hton24(acc->reca_rfid, ep->did);
2073 hton24(acc->reca_rfid, ep->sid);
2074 acc->reca_fc4value = htonl(ep->seq.rec_data);
2075 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
2078 fc_fill_reply_hdr(fp, rfp, FC_RCTL_ELS_REP, 0);
2079 lport->tt.frame_send(lport, fp);
2081 fc_exch_release(ep);
2085 fc_exch_release(ep);
2087 fc_seq_ls_rjt(rfp, reason, explan);
2091 * fc_exch_rrq_resp() - Handler for RRQ responses
2092 * @sp: The sequence that the RRQ is on
2093 * @fp: The RRQ frame
2094 * @arg: The exchange that the RRQ is on
2096 * TODO: fix error handler.
2098 static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
2100 struct fc_exch *aborted_ep = arg;
2104 int err = PTR_ERR(fp);
2106 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
2108 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
2109 "frame error %d\n", err);
2113 op = fc_frame_payload_op(fp);
2118 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ\n");
2123 FC_EXCH_DBG(aborted_ep, "unexpected response op %x for RRQ\n",
2129 fc_exch_done(&aborted_ep->seq);
2130 /* drop hold for rec qual */
2131 fc_exch_release(aborted_ep);
2136 * fc_exch_seq_send() - Send a frame using a new exchange and sequence
2137 * @lport: The local port to send the frame on
2138 * @fp: The frame to be sent
2139 * @resp: The response handler for this request
2140 * @destructor: The destructor for the exchange
2141 * @arg: The argument to be passed to the response handler
2142 * @timer_msec: The timeout period for the exchange
2144 * The exchange response handler is set in this routine to resp()
2145 * function pointer. It can be called in two scenarios: if a timeout
2146 * occurs or if a response frame is received for the exchange. The
2147 * fc_frame pointer in response handler will also indicate timeout
2148 * as error using IS_ERR related macros.
2150 * The exchange destructor handler is also set in this routine.
2151 * The destructor handler is invoked by EM layer when exchange
2152 * is about to free, this can be used by caller to free its
2153 * resources along with exchange free.
2155 * The arg is passed back to resp and destructor handler.
2157 * The timeout value (in msec) for an exchange is set if non zero
2158 * timer_msec argument is specified. The timer is canceled when
2159 * it fires or when the exchange is done. The exchange timeout handler
2160 * is registered by EM layer.
2162 * The frame pointer with some of the header's fields must be
2163 * filled before calling this routine, those fields are:
2170 * - parameter or relative offset
2172 struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
2173 struct fc_frame *fp,
2174 void (*resp)(struct fc_seq *,
2175 struct fc_frame *fp,
2177 void (*destructor)(struct fc_seq *, void *),
2178 void *arg, u32 timer_msec)
2181 struct fc_seq *sp = NULL;
2182 struct fc_frame_header *fh;
2183 struct fc_fcp_pkt *fsp = NULL;
2186 ep = fc_exch_alloc(lport, fp);
2191 ep->esb_stat |= ESB_ST_SEQ_INIT;
2192 fh = fc_frame_header_get(fp);
2193 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
2195 ep->destructor = destructor;
2197 ep->r_a_tov = lport->r_a_tov;
2201 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
2202 ep->f_ctl = ntoh24(fh->fh_f_ctl);
2203 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
2206 if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD) {
2208 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
2211 if (unlikely(lport->tt.frame_send(lport, fp)))
2215 fc_exch_timer_set_locked(ep, timer_msec);
2216 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
2218 if (ep->f_ctl & FC_FC_SEQ_INIT)
2219 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
2220 spin_unlock_bh(&ep->ex_lock);
2224 fc_fcp_ddp_done(fsp);
2225 rc = fc_exch_done_locked(ep);
2226 spin_unlock_bh(&ep->ex_lock);
2231 EXPORT_SYMBOL(fc_exch_seq_send);
2234 * fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command
2235 * @ep: The exchange to send the RRQ on
2237 * This tells the remote port to stop blocking the use of
2238 * the exchange and the seq_cnt range.
2240 static void fc_exch_rrq(struct fc_exch *ep)
2242 struct fc_lport *lport;
2243 struct fc_els_rrq *rrq;
2244 struct fc_frame *fp;
2249 fp = fc_frame_alloc(lport, sizeof(*rrq));
2253 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
2254 memset(rrq, 0, sizeof(*rrq));
2255 rrq->rrq_cmd = ELS_RRQ;
2256 hton24(rrq->rrq_s_id, ep->sid);
2257 rrq->rrq_ox_id = htons(ep->oxid);
2258 rrq->rrq_rx_id = htons(ep->rxid);
2261 if (ep->esb_stat & ESB_ST_RESP)
2264 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
2265 lport->port_id, FC_TYPE_ELS,
2266 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
2268 if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep,
2273 FC_EXCH_DBG(ep, "exch: RRQ send failed\n");
2274 spin_lock_bh(&ep->ex_lock);
2275 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
2276 spin_unlock_bh(&ep->ex_lock);
2277 /* drop hold for rec qual */
2278 fc_exch_release(ep);
2281 ep->esb_stat |= ESB_ST_REC_QUAL;
2282 fc_exch_timer_set_locked(ep, ep->r_a_tov);
2283 spin_unlock_bh(&ep->ex_lock);
2287 * fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests
2288 * @fp: The RRQ frame, not freed here.
2290 static void fc_exch_els_rrq(struct fc_frame *fp)
2292 struct fc_lport *lport;
2293 struct fc_exch *ep = NULL; /* request or subject exchange */
2294 struct fc_els_rrq *rp;
2297 enum fc_els_rjt_explan explan;
2300 rp = fc_frame_payload_get(fp, sizeof(*rp));
2301 explan = ELS_EXPL_INV_LEN;
2306 * lookup subject exchange.
2308 sid = ntoh24(rp->rrq_s_id); /* subject source */
2309 xid = fc_host_port_id(lport->host) == sid ?
2310 ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
2311 ep = fc_exch_lookup(lport, xid);
2312 explan = ELS_EXPL_OXID_RXID;
2315 spin_lock_bh(&ep->ex_lock);
2316 FC_EXCH_DBG(ep, "RRQ request from %x: xid %x rxid %x oxid %x\n",
2317 sid, xid, ntohs(rp->rrq_rx_id), ntohs(rp->rrq_ox_id));
2318 if (ep->oxid != ntohs(rp->rrq_ox_id))
2320 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
2321 ep->rxid != FC_XID_UNKNOWN)
2323 explan = ELS_EXPL_SID;
2328 * Clear Recovery Qualifier state, and cancel timer if complete.
2330 if (ep->esb_stat & ESB_ST_REC_QUAL) {
2331 ep->esb_stat &= ~ESB_ST_REC_QUAL;
2332 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
2334 if (ep->esb_stat & ESB_ST_COMPLETE)
2335 fc_exch_timer_cancel(ep);
2337 spin_unlock_bh(&ep->ex_lock);
2346 spin_unlock_bh(&ep->ex_lock);
2348 fc_seq_ls_rjt(fp, ELS_RJT_LOGIC, explan);
2351 fc_exch_release(ep); /* drop hold from fc_exch_find */
2355 * fc_exch_update_stats() - update exches stats to lport
2356 * @lport: The local port to update exchange manager stats
2358 void fc_exch_update_stats(struct fc_lport *lport)
2360 struct fc_host_statistics *st;
2361 struct fc_exch_mgr_anchor *ema;
2362 struct fc_exch_mgr *mp;
2364 st = &lport->host_stats;
2366 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2368 st->fc_no_free_exch += atomic_read(&mp->stats.no_free_exch);
2369 st->fc_no_free_exch_xid +=
2370 atomic_read(&mp->stats.no_free_exch_xid);
2371 st->fc_xid_not_found += atomic_read(&mp->stats.xid_not_found);
2372 st->fc_xid_busy += atomic_read(&mp->stats.xid_busy);
2373 st->fc_seq_not_found += atomic_read(&mp->stats.seq_not_found);
2374 st->fc_non_bls_resp += atomic_read(&mp->stats.non_bls_resp);
2377 EXPORT_SYMBOL(fc_exch_update_stats);
2380 * fc_exch_mgr_add() - Add an exchange manager to a local port's list of EMs
2381 * @lport: The local port to add the exchange manager to
2382 * @mp: The exchange manager to be added to the local port
2383 * @match: The match routine that indicates when this EM should be used
2385 struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
2386 struct fc_exch_mgr *mp,
2387 bool (*match)(struct fc_frame *))
2389 struct fc_exch_mgr_anchor *ema;
2391 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
2397 /* add EM anchor to EM anchors list */
2398 list_add_tail(&ema->ema_list, &lport->ema_list);
2399 kref_get(&mp->kref);
2402 EXPORT_SYMBOL(fc_exch_mgr_add);
2405 * fc_exch_mgr_destroy() - Destroy an exchange manager
2406 * @kref: The reference to the EM to be destroyed
2408 static void fc_exch_mgr_destroy(struct kref *kref)
2410 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
2412 mempool_destroy(mp->ep_pool);
2413 free_percpu(mp->pool);
2418 * fc_exch_mgr_del() - Delete an EM from a local port's list
2419 * @ema: The exchange manager anchor identifying the EM to be deleted
2421 void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
2423 /* remove EM anchor from EM anchors list */
2424 list_del(&ema->ema_list);
2425 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
2428 EXPORT_SYMBOL(fc_exch_mgr_del);
2431 * fc_exch_mgr_list_clone() - Share all exchange manager objects
2432 * @src: Source lport to clone exchange managers from
2433 * @dst: New lport that takes references to all the exchange managers
2435 int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)
2437 struct fc_exch_mgr_anchor *ema, *tmp;
2439 list_for_each_entry(ema, &src->ema_list, ema_list) {
2440 if (!fc_exch_mgr_add(dst, ema->mp, ema->match))
2445 list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)
2446 fc_exch_mgr_del(ema);
2449 EXPORT_SYMBOL(fc_exch_mgr_list_clone);
2452 * fc_exch_mgr_alloc() - Allocate an exchange manager
2453 * @lport: The local port that the new EM will be associated with
2454 * @class: The default FC class for new exchanges
2455 * @min_xid: The minimum XID for exchanges from the new EM
2456 * @max_xid: The maximum XID for exchanges from the new EM
2457 * @match: The match routine for the new EM
2459 struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport,
2460 enum fc_class class,
2461 u16 min_xid, u16 max_xid,
2462 bool (*match)(struct fc_frame *))
2464 struct fc_exch_mgr *mp;
2465 u16 pool_exch_range;
2468 struct fc_exch_pool *pool;
2470 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
2471 (min_xid & fc_cpu_mask) != 0) {
2472 FC_LPORT_DBG(lport, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
2478 * allocate memory for EM
2480 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
2486 /* adjust em exch xid range for offload */
2487 mp->min_xid = min_xid;
2489 /* reduce range so per cpu pool fits into PCPU_MIN_UNIT_SIZE pool */
2490 pool_exch_range = (PCPU_MIN_UNIT_SIZE - sizeof(*pool)) /
2491 sizeof(struct fc_exch *);
2492 if ((max_xid - min_xid + 1) / (fc_cpu_mask + 1) > pool_exch_range) {
2493 mp->max_xid = pool_exch_range * (fc_cpu_mask + 1) +
2496 mp->max_xid = max_xid;
2497 pool_exch_range = (mp->max_xid - mp->min_xid + 1) /
2501 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
2506 * Setup per cpu exch pool with entire exchange id range equally
2507 * divided across all cpus. The exch pointers array memory is
2508 * allocated for exch range per pool.
2510 mp->pool_max_index = pool_exch_range - 1;
2513 * Allocate and initialize per cpu exch pool
2515 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
2516 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
2519 for_each_possible_cpu(cpu) {
2520 pool = per_cpu_ptr(mp->pool, cpu);
2521 pool->next_index = 0;
2522 pool->left = FC_XID_UNKNOWN;
2523 pool->right = FC_XID_UNKNOWN;
2524 spin_lock_init(&pool->lock);
2525 INIT_LIST_HEAD(&pool->ex_list);
2528 kref_init(&mp->kref);
2529 if (!fc_exch_mgr_add(lport, mp, match)) {
2530 free_percpu(mp->pool);
2535 * Above kref_init() sets mp->kref to 1 and then
2536 * call to fc_exch_mgr_add incremented mp->kref again,
2537 * so adjust that extra increment.
2539 kref_put(&mp->kref, fc_exch_mgr_destroy);
2543 mempool_destroy(mp->ep_pool);
2548 EXPORT_SYMBOL(fc_exch_mgr_alloc);
2551 * fc_exch_mgr_free() - Free all exchange managers on a local port
2552 * @lport: The local port whose EMs are to be freed
2554 void fc_exch_mgr_free(struct fc_lport *lport)
2556 struct fc_exch_mgr_anchor *ema, *next;
2558 flush_workqueue(fc_exch_workqueue);
2559 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
2560 fc_exch_mgr_del(ema);
2562 EXPORT_SYMBOL(fc_exch_mgr_free);
2565 * fc_find_ema() - Lookup and return appropriate Exchange Manager Anchor depending
2568 * @lport: The local port the frame was received on
2569 * @fh: The received frame header
2571 static struct fc_exch_mgr_anchor *fc_find_ema(u32 f_ctl,
2572 struct fc_lport *lport,
2573 struct fc_frame_header *fh)
2575 struct fc_exch_mgr_anchor *ema;
2578 if (f_ctl & FC_FC_EX_CTX)
2579 xid = ntohs(fh->fh_ox_id);
2581 xid = ntohs(fh->fh_rx_id);
2582 if (xid == FC_XID_UNKNOWN)
2583 return list_entry(lport->ema_list.prev,
2584 typeof(*ema), ema_list);
2587 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2588 if ((xid >= ema->mp->min_xid) &&
2589 (xid <= ema->mp->max_xid))
2595 * fc_exch_recv() - Handler for received frames
2596 * @lport: The local port the frame was received on
2597 * @fp: The received frame
2599 void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)
2601 struct fc_frame_header *fh = fc_frame_header_get(fp);
2602 struct fc_exch_mgr_anchor *ema;
2606 if (!lport || lport->state == LPORT_ST_DISABLED) {
2607 FC_LIBFC_DBG("Receiving frames for an lport that "
2608 "has not been initialized correctly\n");
2613 f_ctl = ntoh24(fh->fh_f_ctl);
2614 ema = fc_find_ema(f_ctl, lport, fh);
2616 FC_LPORT_DBG(lport, "Unable to find Exchange Manager Anchor,"
2617 "fc_ctl <0x%x>, xid <0x%x>\n",
2619 (f_ctl & FC_FC_EX_CTX) ?
2620 ntohs(fh->fh_ox_id) :
2621 ntohs(fh->fh_rx_id));
2627 * If frame is marked invalid, just drop it.
2629 switch (fr_eof(fp)) {
2631 if (f_ctl & FC_FC_END_SEQ)
2632 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2635 if (fh->fh_type == FC_TYPE_BLS)
2636 fc_exch_recv_bls(ema->mp, fp);
2637 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2639 fc_exch_recv_seq_resp(ema->mp, fp);
2640 else if (f_ctl & FC_FC_SEQ_CTX)
2641 fc_exch_recv_resp(ema->mp, fp);
2642 else /* no EX_CTX and no SEQ_CTX */
2643 fc_exch_recv_req(lport, ema->mp, fp);
2646 FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)",
2651 EXPORT_SYMBOL(fc_exch_recv);
2654 * fc_exch_init() - Initialize the exchange layer for a local port
2655 * @lport: The local port to initialize the exchange layer for
2657 int fc_exch_init(struct fc_lport *lport)
2659 if (!lport->tt.exch_mgr_reset)
2660 lport->tt.exch_mgr_reset = fc_exch_mgr_reset;
2664 EXPORT_SYMBOL(fc_exch_init);
2667 * fc_setup_exch_mgr() - Setup an exchange manager
2669 int fc_setup_exch_mgr(void)
2671 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2672 0, SLAB_HWCACHE_ALIGN, NULL);
2677 * Initialize fc_cpu_mask and fc_cpu_order. The
2678 * fc_cpu_mask is set for nr_cpu_ids rounded up
2679 * to order of 2's * power and order is stored
2680 * in fc_cpu_order as this is later required in
2681 * mapping between an exch id and exch array index
2682 * in per cpu exch pool.
2684 * This round up is required to align fc_cpu_mask
2685 * to exchange id's lower bits such that all incoming
2686 * frames of an exchange gets delivered to the same
2687 * cpu on which exchange originated by simple bitwise
2688 * AND operation between fc_cpu_mask and exchange id.
2690 fc_cpu_order = ilog2(roundup_pow_of_two(nr_cpu_ids));
2691 fc_cpu_mask = (1 << fc_cpu_order) - 1;
2693 fc_exch_workqueue = create_singlethread_workqueue("fc_exch_workqueue");
2694 if (!fc_exch_workqueue)
2698 kmem_cache_destroy(fc_em_cachep);
2703 * fc_destroy_exch_mgr() - Destroy an exchange manager
2705 void fc_destroy_exch_mgr(void)
2707 destroy_workqueue(fc_exch_workqueue);
2708 kmem_cache_destroy(fc_em_cachep);