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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright(c) 2007 Intel Corporation. All rights reserved.4 * Copyright(c) 2008 Red Hat, Inc. All rights reserved.5 * Copyright(c) 2008 Mike Christie6 *7 * Maintained at www.Open-FCoE.org8 */9 10/*11 * Fibre Channel exchange and sequence handling.12 */13 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>19 20#include <scsi/fc/fc_fc2.h>21 22#include <scsi/libfc.h>23 24#include "fc_libfc.h"25 26u16 fc_cpu_mask; /* cpu mask for possible cpus */27EXPORT_SYMBOL(fc_cpu_mask);28static u16 fc_cpu_order; /* 2's power to represent total possible cpus */29static struct kmem_cache *fc_em_cachep; /* cache for exchanges */30static struct workqueue_struct *fc_exch_workqueue;31 32/*33 * Structure and function definitions for managing Fibre Channel Exchanges34 * and Sequences.35 *36 * The three primary structures used here are fc_exch_mgr, fc_exch, and fc_seq.37 *38 * fc_exch_mgr holds the exchange state for an N port39 *40 * fc_exch holds state for one exchange and links to its active sequence.41 *42 * fc_seq holds the state for an individual sequence.43 */44 45/**46 * struct fc_exch_pool - Per cpu exchange pool47 * @next_index: Next possible free exchange index48 * @total_exches: Total allocated exchanges49 * @lock: Exch pool lock50 * @ex_list: List of exchanges51 * @left: Cache of free slot in exch array52 * @right: Cache of free slot in exch array53 *54 * This structure manages per cpu exchanges in array of exchange pointers.55 * This array is allocated followed by struct fc_exch_pool memory for56 * assigned range of exchanges to per cpu pool.57 */58struct fc_exch_pool {59 spinlock_t lock;60 struct list_head ex_list;61 u16 next_index;62 u16 total_exches;63 64 u16 left;65 u16 right;66} ____cacheline_aligned_in_smp;67 68/**69 * struct fc_exch_mgr - The Exchange Manager (EM).70 * @class: Default class for new sequences71 * @kref: Reference counter72 * @min_xid: Minimum exchange ID73 * @max_xid: Maximum exchange ID74 * @ep_pool: Reserved exchange pointers75 * @pool_max_index: Max exch array index in exch pool76 * @pool: Per cpu exch pool77 * @lport: Local exchange port78 * @stats: Statistics structure79 *80 * This structure is the center for creating exchanges and sequences.81 * It manages the allocation of exchange IDs.82 */83struct fc_exch_mgr {84 struct fc_exch_pool __percpu *pool;85 mempool_t *ep_pool;86 struct fc_lport *lport;87 enum fc_class class;88 struct kref kref;89 u16 min_xid;90 u16 max_xid;91 u16 pool_max_index;92 93 struct {94 atomic_t no_free_exch;95 atomic_t no_free_exch_xid;96 atomic_t xid_not_found;97 atomic_t xid_busy;98 atomic_t seq_not_found;99 atomic_t non_bls_resp;100 } stats;101};102 103/**104 * struct fc_exch_mgr_anchor - primary structure for list of EMs105 * @ema_list: Exchange Manager Anchor list106 * @mp: Exchange Manager associated with this anchor107 * @match: Routine to determine if this anchor's EM should be used108 *109 * When walking the list of anchors the match routine will be called110 * for each anchor to determine if that EM should be used. The last111 * anchor in the list will always match to handle any exchanges not112 * handled by other EMs. The non-default EMs would be added to the113 * anchor list by HW that provides offloads.114 */115struct fc_exch_mgr_anchor {116 struct list_head ema_list;117 struct fc_exch_mgr *mp;118 bool (*match)(struct fc_frame *);119};120 121static void fc_exch_rrq(struct fc_exch *);122static void fc_seq_ls_acc(struct fc_frame *);123static void fc_seq_ls_rjt(struct fc_frame *, enum fc_els_rjt_reason,124 enum fc_els_rjt_explan);125static void fc_exch_els_rec(struct fc_frame *);126static void fc_exch_els_rrq(struct fc_frame *);127 128/*129 * Internal implementation notes.130 *131 * The exchange manager is one by default in libfc but LLD may choose132 * to have one per CPU. The sequence manager is one per exchange manager133 * and currently never separated.134 *135 * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field136 * assigned by the Sequence Initiator that shall be unique for a specific137 * D_ID and S_ID pair while the Sequence is open." Note that it isn't138 * qualified by exchange ID, which one might think it would be.139 * In practice this limits the number of open sequences and exchanges to 256140 * per session. For most targets we could treat this limit as per exchange.141 *142 * The exchange and its sequence are freed when the last sequence is received.143 * It's possible for the remote port to leave an exchange open without144 * sending any sequences.145 *146 * Notes on reference counts:147 *148 * Exchanges are reference counted and exchange gets freed when the reference149 * count becomes zero.150 *151 * Timeouts:152 * Sequences are timed out for E_D_TOV and R_A_TOV.153 *154 * Sequence event handling:155 *156 * The following events may occur on initiator sequences:157 *158 * Send.159 * For now, the whole thing is sent.160 * Receive ACK161 * This applies only to class F.162 * The sequence is marked complete.163 * ULP completion.164 * The upper layer calls fc_exch_done() when done165 * with exchange and sequence tuple.166 * RX-inferred completion.167 * When we receive the next sequence on the same exchange, we can168 * retire the previous sequence ID. (XXX not implemented).169 * Timeout.170 * R_A_TOV frees the sequence ID. If we're waiting for ACK,171 * E_D_TOV causes abort and calls upper layer response handler172 * with FC_EX_TIMEOUT error.173 * Receive RJT174 * XXX defer.175 * Send ABTS176 * On timeout.177 *178 * The following events may occur on recipient sequences:179 *180 * Receive181 * Allocate sequence for first frame received.182 * Hold during receive handler.183 * Release when final frame received.184 * Keep status of last N of these for the ELS RES command. XXX TBD.185 * Receive ABTS186 * Deallocate sequence187 * Send RJT188 * Deallocate189 *190 * For now, we neglect conditions where only part of a sequence was191 * received or transmitted, or where out-of-order receipt is detected.192 */193 194/*195 * Locking notes:196 *197 * The EM code run in a per-CPU worker thread.198 *199 * To protect against concurrency between a worker thread code and timers,200 * sequence allocation and deallocation must be locked.201 * - exchange refcnt can be done atomicly without locks.202 * - sequence allocation must be locked by exch lock.203 * - If the EM pool lock and ex_lock must be taken at the same time, then the204 * EM pool lock must be taken before the ex_lock.205 */206 207/*208 * opcode names for debugging.209 */210static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;211 212/**213 * fc_exch_name_lookup() - Lookup name by opcode214 * @op: Opcode to be looked up215 * @table: Opcode/name table216 * @max_index: Index not to be exceeded217 *218 * This routine is used to determine a human-readable string identifying219 * a R_CTL opcode.220 */221static inline const char *fc_exch_name_lookup(unsigned int op, char **table,222 unsigned int max_index)223{224 const char *name = NULL;225 226 if (op < max_index)227 name = table[op];228 if (!name)229 name = "unknown";230 return name;231}232 233/**234 * fc_exch_rctl_name() - Wrapper routine for fc_exch_name_lookup()235 * @op: The opcode to be looked up236 */237static const char *fc_exch_rctl_name(unsigned int op)238{239 return fc_exch_name_lookup(op, fc_exch_rctl_names,240 ARRAY_SIZE(fc_exch_rctl_names));241}242 243/**244 * fc_exch_hold() - Increment an exchange's reference count245 * @ep: Echange to be held246 */247static inline void fc_exch_hold(struct fc_exch *ep)248{249 atomic_inc(&ep->ex_refcnt);250}251 252/**253 * fc_exch_setup_hdr() - Initialize a FC header by initializing some fields254 * and determine SOF and EOF.255 * @ep: The exchange to that will use the header256 * @fp: The frame whose header is to be modified257 * @f_ctl: F_CTL bits that will be used for the frame header258 *259 * The fields initialized by this routine are: fh_ox_id, fh_rx_id,260 * fh_seq_id, fh_seq_cnt and the SOF and EOF.261 */262static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,263 u32 f_ctl)264{265 struct fc_frame_header *fh = fc_frame_header_get(fp);266 u16 fill;267 268 fr_sof(fp) = ep->class;269 if (ep->seq.cnt)270 fr_sof(fp) = fc_sof_normal(ep->class);271 272 if (f_ctl & FC_FC_END_SEQ) {273 fr_eof(fp) = FC_EOF_T;274 if (fc_sof_needs_ack((enum fc_sof)ep->class))275 fr_eof(fp) = FC_EOF_N;276 /*277 * From F_CTL.278 * The number of fill bytes to make the length a 4-byte279 * multiple is the low order 2-bits of the f_ctl.280 * The fill itself will have been cleared by the frame281 * allocation.282 * After this, the length will be even, as expected by283 * the transport.284 */285 fill = fr_len(fp) & 3;286 if (fill) {287 fill = 4 - fill;288 /* TODO, this may be a problem with fragmented skb */289 skb_put(fp_skb(fp), fill);290 hton24(fh->fh_f_ctl, f_ctl | fill);291 }292 } else {293 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */294 fr_eof(fp) = FC_EOF_N;295 }296 297 /* Initialize remaining fh fields from fc_fill_fc_hdr */298 fh->fh_ox_id = htons(ep->oxid);299 fh->fh_rx_id = htons(ep->rxid);300 fh->fh_seq_id = ep->seq.id;301 fh->fh_seq_cnt = htons(ep->seq.cnt);302}303 304/**305 * fc_exch_release() - Decrement an exchange's reference count306 * @ep: Exchange to be released307 *308 * If the reference count reaches zero and the exchange is complete,309 * it is freed.310 */311static void fc_exch_release(struct fc_exch *ep)312{313 struct fc_exch_mgr *mp;314 315 if (atomic_dec_and_test(&ep->ex_refcnt)) {316 mp = ep->em;317 if (ep->destructor)318 ep->destructor(&ep->seq, ep->arg);319 WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));320 mempool_free(ep, mp->ep_pool);321 }322}323 324/**325 * fc_exch_timer_cancel() - cancel exch timer326 * @ep: The exchange whose timer to be canceled327 */328static inline void fc_exch_timer_cancel(struct fc_exch *ep)329{330 if (cancel_delayed_work(&ep->timeout_work)) {331 FC_EXCH_DBG(ep, "Exchange timer canceled\n");332 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */333 }334}335 336/**337 * fc_exch_timer_set_locked() - Start a timer for an exchange w/ the338 * the exchange lock held339 * @ep: The exchange whose timer will start340 * @timer_msec: The timeout period341 *342 * Used for upper level protocols to time out the exchange.343 * The timer is cancelled when it fires or when the exchange completes.344 */345static inline void fc_exch_timer_set_locked(struct fc_exch *ep,346 unsigned int timer_msec)347{348 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))349 return;350 351 FC_EXCH_DBG(ep, "Exchange timer armed : %d msecs\n", timer_msec);352 353 fc_exch_hold(ep); /* hold for timer */354 if (!queue_delayed_work(fc_exch_workqueue, &ep->timeout_work,355 msecs_to_jiffies(timer_msec))) {356 FC_EXCH_DBG(ep, "Exchange already queued\n");357 fc_exch_release(ep);358 }359}360 361/**362 * fc_exch_timer_set() - Lock the exchange and set the timer363 * @ep: The exchange whose timer will start364 * @timer_msec: The timeout period365 */366static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec)367{368 spin_lock_bh(&ep->ex_lock);369 fc_exch_timer_set_locked(ep, timer_msec);370 spin_unlock_bh(&ep->ex_lock);371}372 373/**374 * fc_exch_done_locked() - Complete an exchange with the exchange lock held375 * @ep: The exchange that is complete376 *377 * Note: May sleep if invoked from outside a response handler.378 */379static int fc_exch_done_locked(struct fc_exch *ep)380{381 int rc = 1;382 383 /*384 * We must check for completion in case there are two threads385 * tyring to complete this. But the rrq code will reuse the386 * ep, and in that case we only clear the resp and set it as387 * complete, so it can be reused by the timer to send the rrq.388 */389 if (ep->state & FC_EX_DONE)390 return rc;391 ep->esb_stat |= ESB_ST_COMPLETE;392 393 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {394 ep->state |= FC_EX_DONE;395 fc_exch_timer_cancel(ep);396 rc = 0;397 }398 return rc;399}400 401static struct fc_exch fc_quarantine_exch;402 403/**404 * fc_exch_ptr_get() - Return an exchange from an exchange pool405 * @pool: Exchange Pool to get an exchange from406 * @index: Index of the exchange within the pool407 *408 * Use the index to get an exchange from within an exchange pool. exches409 * will point to an array of exchange pointers. The index will select410 * the exchange within the array.411 */412static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,413 u16 index)414{415 struct fc_exch **exches = (struct fc_exch **)(pool + 1);416 return exches[index];417}418 419/**420 * fc_exch_ptr_set() - Assign an exchange to a slot in an exchange pool421 * @pool: The pool to assign the exchange to422 * @index: The index in the pool where the exchange will be assigned423 * @ep: The exchange to assign to the pool424 */425static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,426 struct fc_exch *ep)427{428 ((struct fc_exch **)(pool + 1))[index] = ep;429}430 431/**432 * fc_exch_delete() - Delete an exchange433 * @ep: The exchange to be deleted434 */435static void fc_exch_delete(struct fc_exch *ep)436{437 struct fc_exch_pool *pool;438 u16 index;439 440 pool = ep->pool;441 spin_lock_bh(&pool->lock);442 WARN_ON(pool->total_exches <= 0);443 pool->total_exches--;444 445 /* update cache of free slot */446 index = (ep->xid - ep->em->min_xid) >> fc_cpu_order;447 if (!(ep->state & FC_EX_QUARANTINE)) {448 if (pool->left == FC_XID_UNKNOWN)449 pool->left = index;450 else if (pool->right == FC_XID_UNKNOWN)451 pool->right = index;452 else453 pool->next_index = index;454 fc_exch_ptr_set(pool, index, NULL);455 } else {456 fc_exch_ptr_set(pool, index, &fc_quarantine_exch);457 }458 list_del(&ep->ex_list);459 spin_unlock_bh(&pool->lock);460 fc_exch_release(ep); /* drop hold for exch in mp */461}462 463static int fc_seq_send_locked(struct fc_lport *lport, struct fc_seq *sp,464 struct fc_frame *fp)465{466 struct fc_exch *ep;467 struct fc_frame_header *fh = fc_frame_header_get(fp);468 int error = -ENXIO;469 u32 f_ctl;470 u8 fh_type = fh->fh_type;471 472 ep = fc_seq_exch(sp);473 474 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL)) {475 fc_frame_free(fp);476 goto out;477 }478 479 WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT));480 481 f_ctl = ntoh24(fh->fh_f_ctl);482 fc_exch_setup_hdr(ep, fp, f_ctl);483 fr_encaps(fp) = ep->encaps;484 485 /*486 * update sequence count if this frame is carrying487 * multiple FC frames when sequence offload is enabled488 * by LLD.489 */490 if (fr_max_payload(fp))491 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),492 fr_max_payload(fp));493 else494 sp->cnt++;495 496 /*497 * Send the frame.498 */499 error = lport->tt.frame_send(lport, fp);500 501 if (fh_type == FC_TYPE_BLS)502 goto out;503 504 /*505 * Update the exchange and sequence flags,506 * assuming all frames for the sequence have been sent.507 * We can only be called to send once for each sequence.508 */509 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */510 if (f_ctl & FC_FC_SEQ_INIT)511 ep->esb_stat &= ~ESB_ST_SEQ_INIT;512out:513 return error;514}515 516/**517 * fc_seq_send() - Send a frame using existing sequence/exchange pair518 * @lport: The local port that the exchange will be sent on519 * @sp: The sequence to be sent520 * @fp: The frame to be sent on the exchange521 *522 * Note: The frame will be freed either by a direct call to fc_frame_free(fp)523 * or indirectly by calling libfc_function_template.frame_send().524 */525int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp, struct fc_frame *fp)526{527 struct fc_exch *ep;528 int error;529 ep = fc_seq_exch(sp);530 spin_lock_bh(&ep->ex_lock);531 error = fc_seq_send_locked(lport, sp, fp);532 spin_unlock_bh(&ep->ex_lock);533 return error;534}535EXPORT_SYMBOL(fc_seq_send);536 537/**538 * fc_seq_alloc() - Allocate a sequence for a given exchange539 * @ep: The exchange to allocate a new sequence for540 * @seq_id: The sequence ID to be used541 *542 * We don't support multiple originated sequences on the same exchange.543 * By implication, any previously originated sequence on this exchange544 * is complete, and we reallocate the same sequence.545 */546static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)547{548 struct fc_seq *sp;549 550 sp = &ep->seq;551 sp->ssb_stat = 0;552 sp->cnt = 0;553 sp->id = seq_id;554 return sp;555}556 557/**558 * fc_seq_start_next_locked() - Allocate a new sequence on the same559 * exchange as the supplied sequence560 * @sp: The sequence/exchange to get a new sequence for561 */562static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)563{564 struct fc_exch *ep = fc_seq_exch(sp);565 566 sp = fc_seq_alloc(ep, ep->seq_id++);567 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",568 ep->f_ctl, sp->id);569 return sp;570}571 572/**573 * fc_seq_start_next() - Lock the exchange and get a new sequence574 * for a given sequence/exchange pair575 * @sp: The sequence/exchange to get a new exchange for576 */577struct fc_seq *fc_seq_start_next(struct fc_seq *sp)578{579 struct fc_exch *ep = fc_seq_exch(sp);580 581 spin_lock_bh(&ep->ex_lock);582 sp = fc_seq_start_next_locked(sp);583 spin_unlock_bh(&ep->ex_lock);584 585 return sp;586}587EXPORT_SYMBOL(fc_seq_start_next);588 589/*590 * Set the response handler for the exchange associated with a sequence.591 *592 * Note: May sleep if invoked from outside a response handler.593 */594void fc_seq_set_resp(struct fc_seq *sp,595 void (*resp)(struct fc_seq *, struct fc_frame *, void *),596 void *arg)597{598 struct fc_exch *ep = fc_seq_exch(sp);599 DEFINE_WAIT(wait);600 601 spin_lock_bh(&ep->ex_lock);602 while (ep->resp_active && ep->resp_task != current) {603 prepare_to_wait(&ep->resp_wq, &wait, TASK_UNINTERRUPTIBLE);604 spin_unlock_bh(&ep->ex_lock);605 606 schedule();607 608 spin_lock_bh(&ep->ex_lock);609 }610 finish_wait(&ep->resp_wq, &wait);611 ep->resp = resp;612 ep->arg = arg;613 spin_unlock_bh(&ep->ex_lock);614}615EXPORT_SYMBOL(fc_seq_set_resp);616 617/**618 * fc_exch_abort_locked() - Abort an exchange619 * @ep: The exchange to be aborted620 * @timer_msec: The period of time to wait before aborting621 *622 * Abort an exchange and sequence. Generally called because of a623 * exchange timeout or an abort from the upper layer.624 *625 * A timer_msec can be specified for abort timeout, if non-zero626 * timer_msec value is specified then exchange resp handler627 * will be called with timeout error if no response to abort.628 *629 * Locking notes: Called with exch lock held630 *631 * Return value: 0 on success else error code632 */633static int fc_exch_abort_locked(struct fc_exch *ep,634 unsigned int timer_msec)635{636 struct fc_seq *sp;637 struct fc_frame *fp;638 int error;639 640 FC_EXCH_DBG(ep, "exch: abort, time %d msecs\n", timer_msec);641 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||642 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {643 FC_EXCH_DBG(ep, "exch: already completed esb %x state %x\n",644 ep->esb_stat, ep->state);645 return -ENXIO;646 }647 648 /*649 * Send the abort on a new sequence if possible.650 */651 sp = fc_seq_start_next_locked(&ep->seq);652 if (!sp)653 return -ENOMEM;654 655 if (timer_msec)656 fc_exch_timer_set_locked(ep, timer_msec);657 658 if (ep->sid) {659 /*660 * Send an abort for the sequence that timed out.661 */662 fp = fc_frame_alloc(ep->lp, 0);663 if (fp) {664 ep->esb_stat |= ESB_ST_SEQ_INIT;665 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,666 FC_TYPE_BLS, FC_FC_END_SEQ |667 FC_FC_SEQ_INIT, 0);668 error = fc_seq_send_locked(ep->lp, sp, fp);669 } else {670 error = -ENOBUFS;671 }672 } else {673 /*674 * If not logged into the fabric, don't send ABTS but leave675 * sequence active until next timeout.676 */677 error = 0;678 }679 ep->esb_stat |= ESB_ST_ABNORMAL;680 return error;681}682 683/**684 * fc_seq_exch_abort() - Abort an exchange and sequence685 * @req_sp: The sequence to be aborted686 * @timer_msec: The period of time to wait before aborting687 *688 * Generally called because of a timeout or an abort from the upper layer.689 *690 * Return value: 0 on success else error code691 */692int fc_seq_exch_abort(const struct fc_seq *req_sp, unsigned int timer_msec)693{694 struct fc_exch *ep;695 int error;696 697 ep = fc_seq_exch(req_sp);698 spin_lock_bh(&ep->ex_lock);699 error = fc_exch_abort_locked(ep, timer_msec);700 spin_unlock_bh(&ep->ex_lock);701 return error;702}703 704/**705 * fc_invoke_resp() - invoke ep->resp()706 * @ep: The exchange to be operated on707 * @fp: The frame pointer to pass through to ->resp()708 * @sp: The sequence pointer to pass through to ->resp()709 *710 * Notes:711 * It is assumed that after initialization finished (this means the712 * first unlock of ex_lock after fc_exch_alloc()) ep->resp and ep->arg are713 * modified only via fc_seq_set_resp(). This guarantees that none of these714 * two variables changes if ep->resp_active > 0.715 *716 * If an fc_seq_set_resp() call is busy modifying ep->resp and ep->arg when717 * this function is invoked, the first spin_lock_bh() call in this function718 * will wait until fc_seq_set_resp() has finished modifying these variables.719 *720 * Since fc_exch_done() invokes fc_seq_set_resp() it is guaranteed that that721 * ep->resp() won't be invoked after fc_exch_done() has returned.722 *723 * The response handler itself may invoke fc_exch_done(), which will clear the724 * ep->resp pointer.725 *726 * Return value:727 * Returns true if and only if ep->resp has been invoked.728 */729static bool fc_invoke_resp(struct fc_exch *ep, struct fc_seq *sp,730 struct fc_frame *fp)731{732 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);733 void *arg;734 bool res = false;735 736 spin_lock_bh(&ep->ex_lock);737 ep->resp_active++;738 if (ep->resp_task != current)739 ep->resp_task = !ep->resp_task ? current : NULL;740 resp = ep->resp;741 arg = ep->arg;742 spin_unlock_bh(&ep->ex_lock);743 744 if (resp) {745 resp(sp, fp, arg);746 res = true;747 }748 749 spin_lock_bh(&ep->ex_lock);750 if (--ep->resp_active == 0)751 ep->resp_task = NULL;752 spin_unlock_bh(&ep->ex_lock);753 754 if (ep->resp_active == 0)755 wake_up(&ep->resp_wq);756 757 return res;758}759 760/**761 * fc_exch_timeout() - Handle exchange timer expiration762 * @work: The work_struct identifying the exchange that timed out763 */764static void fc_exch_timeout(struct work_struct *work)765{766 struct fc_exch *ep = container_of(work, struct fc_exch,767 timeout_work.work);768 struct fc_seq *sp = &ep->seq;769 u32 e_stat;770 int rc = 1;771 772 FC_EXCH_DBG(ep, "Exchange timed out state %x\n", ep->state);773 774 spin_lock_bh(&ep->ex_lock);775 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))776 goto unlock;777 778 e_stat = ep->esb_stat;779 if (e_stat & ESB_ST_COMPLETE) {780 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;781 spin_unlock_bh(&ep->ex_lock);782 if (e_stat & ESB_ST_REC_QUAL)783 fc_exch_rrq(ep);784 goto done;785 } else {786 if (e_stat & ESB_ST_ABNORMAL)787 rc = fc_exch_done_locked(ep);788 spin_unlock_bh(&ep->ex_lock);789 if (!rc)790 fc_exch_delete(ep);791 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_TIMEOUT));792 fc_seq_set_resp(sp, NULL, ep->arg);793 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);794 goto done;795 }796unlock:797 spin_unlock_bh(&ep->ex_lock);798done:799 /*800 * This release matches the hold taken when the timer was set.801 */802 fc_exch_release(ep);803}804 805/**806 * fc_exch_em_alloc() - Allocate an exchange from a specified EM.807 * @lport: The local port that the exchange is for808 * @mp: The exchange manager that will allocate the exchange809 *810 * Returns pointer to allocated fc_exch with exch lock held.811 */812static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,813 struct fc_exch_mgr *mp)814{815 struct fc_exch *ep;816 unsigned int cpu;817 u16 index;818 struct fc_exch_pool *pool;819 820 /* allocate memory for exchange */821 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);822 if (!ep) {823 atomic_inc(&mp->stats.no_free_exch);824 goto out;825 }826 memset(ep, 0, sizeof(*ep));827 828 cpu = raw_smp_processor_id();829 pool = per_cpu_ptr(mp->pool, cpu);830 spin_lock_bh(&pool->lock);831 832 /* peek cache of free slot */833 if (pool->left != FC_XID_UNKNOWN) {834 if (!WARN_ON(fc_exch_ptr_get(pool, pool->left))) {835 index = pool->left;836 pool->left = FC_XID_UNKNOWN;837 goto hit;838 }839 }840 if (pool->right != FC_XID_UNKNOWN) {841 if (!WARN_ON(fc_exch_ptr_get(pool, pool->right))) {842 index = pool->right;843 pool->right = FC_XID_UNKNOWN;844 goto hit;845 }846 }847 848 index = pool->next_index;849 /* allocate new exch from pool */850 while (fc_exch_ptr_get(pool, index)) {851 index = index == mp->pool_max_index ? 0 : index + 1;852 if (index == pool->next_index)853 goto err;854 }855 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;856hit:857 fc_exch_hold(ep); /* hold for exch in mp */858 spin_lock_init(&ep->ex_lock);859 /*860 * Hold exch lock for caller to prevent fc_exch_reset()861 * from releasing exch while fc_exch_alloc() caller is862 * still working on exch.863 */864 spin_lock_bh(&ep->ex_lock);865 866 fc_exch_ptr_set(pool, index, ep);867 list_add_tail(&ep->ex_list, &pool->ex_list);868 fc_seq_alloc(ep, ep->seq_id++);869 pool->total_exches++;870 spin_unlock_bh(&pool->lock);871 872 /*873 * update exchange874 */875 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;876 ep->em = mp;877 ep->pool = pool;878 ep->lp = lport;879 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */880 ep->rxid = FC_XID_UNKNOWN;881 ep->class = mp->class;882 ep->resp_active = 0;883 init_waitqueue_head(&ep->resp_wq);884 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);885out:886 return ep;887err:888 spin_unlock_bh(&pool->lock);889 atomic_inc(&mp->stats.no_free_exch_xid);890 mempool_free(ep, mp->ep_pool);891 return NULL;892}893 894/**895 * fc_exch_alloc() - Allocate an exchange from an EM on a896 * local port's list of EMs.897 * @lport: The local port that will own the exchange898 * @fp: The FC frame that the exchange will be for899 *900 * This function walks the list of exchange manager(EM)901 * anchors to select an EM for a new exchange allocation. The902 * EM is selected when a NULL match function pointer is encountered903 * or when a call to a match function returns true.904 */905static struct fc_exch *fc_exch_alloc(struct fc_lport *lport,906 struct fc_frame *fp)907{908 struct fc_exch_mgr_anchor *ema;909 struct fc_exch *ep;910 911 list_for_each_entry(ema, &lport->ema_list, ema_list) {912 if (!ema->match || ema->match(fp)) {913 ep = fc_exch_em_alloc(lport, ema->mp);914 if (ep)915 return ep;916 }917 }918 return NULL;919}920 921/**922 * fc_exch_find() - Lookup and hold an exchange923 * @mp: The exchange manager to lookup the exchange from924 * @xid: The XID of the exchange to look up925 */926static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)927{928 struct fc_lport *lport = mp->lport;929 struct fc_exch_pool *pool;930 struct fc_exch *ep = NULL;931 u16 cpu = xid & fc_cpu_mask;932 933 if (xid == FC_XID_UNKNOWN)934 return NULL;935 936 if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {937 pr_err("host%u: lport %6.6x: xid %d invalid CPU %d\n:",938 lport->host->host_no, lport->port_id, xid, cpu);939 return NULL;940 }941 942 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {943 pool = per_cpu_ptr(mp->pool, cpu);944 spin_lock_bh(&pool->lock);945 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);946 if (ep == &fc_quarantine_exch) {947 FC_LPORT_DBG(lport, "xid %x quarantined\n", xid);948 ep = NULL;949 }950 if (ep) {951 WARN_ON(ep->xid != xid);952 fc_exch_hold(ep);953 }954 spin_unlock_bh(&pool->lock);955 }956 return ep;957}958 959 960/**961 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and962 * the memory allocated for the related objects may be freed.963 * @sp: The sequence that has completed964 *965 * Note: May sleep if invoked from outside a response handler.966 */967void fc_exch_done(struct fc_seq *sp)968{969 struct fc_exch *ep = fc_seq_exch(sp);970 int rc;971 972 spin_lock_bh(&ep->ex_lock);973 rc = fc_exch_done_locked(ep);974 spin_unlock_bh(&ep->ex_lock);975 976 fc_seq_set_resp(sp, NULL, ep->arg);977 if (!rc)978 fc_exch_delete(ep);979}980EXPORT_SYMBOL(fc_exch_done);981 982/**983 * fc_exch_resp() - Allocate a new exchange for a response frame984 * @lport: The local port that the exchange was for985 * @mp: The exchange manager to allocate the exchange from986 * @fp: The response frame987 *988 * Sets the responder ID in the frame header.989 */990static struct fc_exch *fc_exch_resp(struct fc_lport *lport,991 struct fc_exch_mgr *mp,992 struct fc_frame *fp)993{994 struct fc_exch *ep;995 struct fc_frame_header *fh;996 997 ep = fc_exch_alloc(lport, fp);998 if (ep) {999 ep->class = fc_frame_class(fp);1000 1001 /*1002 * Set EX_CTX indicating we're responding on this exchange.1003 */1004 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */1005 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */1006 fh = fc_frame_header_get(fp);1007 ep->sid = ntoh24(fh->fh_d_id);1008 ep->did = ntoh24(fh->fh_s_id);1009 ep->oid = ep->did;1010 1011 /*1012 * Allocated exchange has placed the XID in the1013 * originator field. Move it to the responder field,1014 * and set the originator XID from the frame.1015 */1016 ep->rxid = ep->xid;1017 ep->oxid = ntohs(fh->fh_ox_id);1018 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;1019 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)1020 ep->esb_stat &= ~ESB_ST_SEQ_INIT;1021 1022 fc_exch_hold(ep); /* hold for caller */1023 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */1024 }1025 return ep;1026}1027 1028/**1029 * fc_seq_lookup_recip() - Find a sequence where the other end1030 * originated the sequence1031 * @lport: The local port that the frame was sent to1032 * @mp: The Exchange Manager to lookup the exchange from1033 * @fp: The frame associated with the sequence we're looking for1034 *1035 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold1036 * on the ep that should be released by the caller.1037 */1038static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,1039 struct fc_exch_mgr *mp,1040 struct fc_frame *fp)1041{1042 struct fc_frame_header *fh = fc_frame_header_get(fp);1043 struct fc_exch *ep = NULL;1044 struct fc_seq *sp = NULL;1045 enum fc_pf_rjt_reason reject = FC_RJT_NONE;1046 u32 f_ctl;1047 u16 xid;1048 1049 f_ctl = ntoh24(fh->fh_f_ctl);1050 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);1051 1052 /*1053 * Lookup or create the exchange if we will be creating the sequence.1054 */1055 if (f_ctl & FC_FC_EX_CTX) {1056 xid = ntohs(fh->fh_ox_id); /* we originated exch */1057 ep = fc_exch_find(mp, xid);1058 if (!ep) {1059 atomic_inc(&mp->stats.xid_not_found);1060 reject = FC_RJT_OX_ID;1061 goto out;1062 }1063 if (ep->rxid == FC_XID_UNKNOWN)1064 ep->rxid = ntohs(fh->fh_rx_id);1065 else if (ep->rxid != ntohs(fh->fh_rx_id)) {1066 reject = FC_RJT_OX_ID;1067 goto rel;1068 }1069 } else {1070 xid = ntohs(fh->fh_rx_id); /* we are the responder */1071 1072 /*1073 * Special case for MDS issuing an ELS TEST with a1074 * bad rxid of 0.1075 * XXX take this out once we do the proper reject.1076 */1077 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&1078 fc_frame_payload_op(fp) == ELS_TEST) {1079 fh->fh_rx_id = htons(FC_XID_UNKNOWN);1080 xid = FC_XID_UNKNOWN;1081 }1082 1083 /*1084 * new sequence - find the exchange1085 */1086 ep = fc_exch_find(mp, xid);1087 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {1088 if (ep) {1089 atomic_inc(&mp->stats.xid_busy);1090 reject = FC_RJT_RX_ID;1091 goto rel;1092 }1093 ep = fc_exch_resp(lport, mp, fp);1094 if (!ep) {1095 reject = FC_RJT_EXCH_EST; /* XXX */1096 goto out;1097 }1098 xid = ep->xid; /* get our XID */1099 } else if (!ep) {1100 atomic_inc(&mp->stats.xid_not_found);1101 reject = FC_RJT_RX_ID; /* XID not found */1102 goto out;1103 }1104 }1105 1106 spin_lock_bh(&ep->ex_lock);1107 /*1108 * At this point, we have the exchange held.1109 * Find or create the sequence.1110 */1111 if (fc_sof_is_init(fr_sof(fp))) {1112 sp = &ep->seq;1113 sp->ssb_stat |= SSB_ST_RESP;1114 sp->id = fh->fh_seq_id;1115 } else {1116 sp = &ep->seq;1117 if (sp->id != fh->fh_seq_id) {1118 atomic_inc(&mp->stats.seq_not_found);1119 if (f_ctl & FC_FC_END_SEQ) {1120 /*1121 * Update sequence_id based on incoming last1122 * frame of sequence exchange. This is needed1123 * for FC target where DDP has been used1124 * on target where, stack is indicated only1125 * about last frame's (payload _header) header.1126 * Whereas "seq_id" which is part of1127 * frame_header is allocated by initiator1128 * which is totally different from "seq_id"1129 * allocated when XFER_RDY was sent by target.1130 * To avoid false -ve which results into not1131 * sending RSP, hence write request on other1132 * end never finishes.1133 */1134 sp->ssb_stat |= SSB_ST_RESP;1135 sp->id = fh->fh_seq_id;1136 } else {1137 spin_unlock_bh(&ep->ex_lock);1138 1139 /* sequence/exch should exist */1140 reject = FC_RJT_SEQ_ID;1141 goto rel;1142 }1143 }1144 }1145 WARN_ON(ep != fc_seq_exch(sp));1146 1147 if (f_ctl & FC_FC_SEQ_INIT)1148 ep->esb_stat |= ESB_ST_SEQ_INIT;1149 spin_unlock_bh(&ep->ex_lock);1150 1151 fr_seq(fp) = sp;1152out:1153 return reject;1154rel:1155 fc_exch_done(&ep->seq);1156 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */1157 return reject;1158}1159 1160/**1161 * fc_seq_lookup_orig() - Find a sequence where this end1162 * originated the sequence1163 * @mp: The Exchange Manager to lookup the exchange from1164 * @fp: The frame associated with the sequence we're looking for1165 *1166 * Does not hold the sequence for the caller.1167 */1168static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,1169 struct fc_frame *fp)1170{1171 struct fc_frame_header *fh = fc_frame_header_get(fp);1172 struct fc_exch *ep;1173 struct fc_seq *sp = NULL;1174 u32 f_ctl;1175 u16 xid;1176 1177 f_ctl = ntoh24(fh->fh_f_ctl);1178 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);1179 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);1180 ep = fc_exch_find(mp, xid);1181 if (!ep)1182 return NULL;1183 if (ep->seq.id == fh->fh_seq_id) {1184 /*1185 * Save the RX_ID if we didn't previously know it.1186 */1187 sp = &ep->seq;1188 if ((f_ctl & FC_FC_EX_CTX) != 0 &&1189 ep->rxid == FC_XID_UNKNOWN) {1190 ep->rxid = ntohs(fh->fh_rx_id);1191 }1192 }1193 fc_exch_release(ep);1194 return sp;1195}1196 1197/**1198 * fc_exch_set_addr() - Set the source and destination IDs for an exchange1199 * @ep: The exchange to set the addresses for1200 * @orig_id: The originator's ID1201 * @resp_id: The responder's ID1202 *1203 * Note this must be done before the first sequence of the exchange is sent.1204 */1205static void fc_exch_set_addr(struct fc_exch *ep,1206 u32 orig_id, u32 resp_id)1207{1208 ep->oid = orig_id;1209 if (ep->esb_stat & ESB_ST_RESP) {1210 ep->sid = resp_id;1211 ep->did = orig_id;1212 } else {1213 ep->sid = orig_id;1214 ep->did = resp_id;1215 }1216}1217 1218/**1219 * fc_seq_els_rsp_send() - Send an ELS response using information from1220 * the existing sequence/exchange.1221 * @fp: The received frame1222 * @els_cmd: The ELS command to be sent1223 * @els_data: The ELS data to be sent1224 *1225 * The received frame is not freed.1226 */1227void fc_seq_els_rsp_send(struct fc_frame *fp, enum fc_els_cmd els_cmd,1228 struct fc_seq_els_data *els_data)1229{1230 switch (els_cmd) {1231 case ELS_LS_RJT:1232 fc_seq_ls_rjt(fp, els_data->reason, els_data->explan);1233 break;1234 case ELS_LS_ACC:1235 fc_seq_ls_acc(fp);1236 break;1237 case ELS_RRQ:1238 fc_exch_els_rrq(fp);1239 break;1240 case ELS_REC:1241 fc_exch_els_rec(fp);1242 break;1243 default:1244 FC_LPORT_DBG(fr_dev(fp), "Invalid ELS CMD:%x\n", els_cmd);1245 }1246}1247EXPORT_SYMBOL_GPL(fc_seq_els_rsp_send);1248 1249/**1250 * fc_seq_send_last() - Send a sequence that is the last in the exchange1251 * @sp: The sequence that is to be sent1252 * @fp: The frame that will be sent on the sequence1253 * @rctl: The R_CTL information to be sent1254 * @fh_type: The frame header type1255 */1256static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,1257 enum fc_rctl rctl, enum fc_fh_type fh_type)1258{1259 u32 f_ctl;1260 struct fc_exch *ep = fc_seq_exch(sp);1261 1262 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;1263 f_ctl |= ep->f_ctl;1264 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);1265 fc_seq_send_locked(ep->lp, sp, fp);1266}1267 1268/**1269 * fc_seq_send_ack() - Send an acknowledgement that we've received a frame1270 * @sp: The sequence to send the ACK on1271 * @rx_fp: The received frame that is being acknoledged1272 *1273 * Send ACK_1 (or equiv.) indicating we received something.1274 */1275static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)1276{1277 struct fc_frame *fp;1278 struct fc_frame_header *rx_fh;1279 struct fc_frame_header *fh;1280 struct fc_exch *ep = fc_seq_exch(sp);1281 struct fc_lport *lport = ep->lp;1282 unsigned int f_ctl;1283 1284 /*1285 * Don't send ACKs for class 3.1286 */1287 if (fc_sof_needs_ack(fr_sof(rx_fp))) {1288 fp = fc_frame_alloc(lport, 0);1289 if (!fp) {1290 FC_EXCH_DBG(ep, "Drop ACK request, out of memory\n");1291 return;1292 }1293 1294 fh = fc_frame_header_get(fp);1295 fh->fh_r_ctl = FC_RCTL_ACK_1;1296 fh->fh_type = FC_TYPE_BLS;1297 1298 /*1299 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).1300 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.1301 * Bits 9-8 are meaningful (retransmitted or unidirectional).1302 * Last ACK uses bits 7-6 (continue sequence),1303 * bits 5-4 are meaningful (what kind of ACK to use).1304 */1305 rx_fh = fc_frame_header_get(rx_fp);1306 f_ctl = ntoh24(rx_fh->fh_f_ctl);1307 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |1308 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |1309 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |1310 FC_FC_RETX_SEQ | FC_FC_UNI_TX;1311 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;1312 hton24(fh->fh_f_ctl, f_ctl);1313 1314 fc_exch_setup_hdr(ep, fp, f_ctl);1315 fh->fh_seq_id = rx_fh->fh_seq_id;1316 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;1317 fh->fh_parm_offset = htonl(1); /* ack single frame */1318 1319 fr_sof(fp) = fr_sof(rx_fp);1320 if (f_ctl & FC_FC_END_SEQ)1321 fr_eof(fp) = FC_EOF_T;1322 else1323 fr_eof(fp) = FC_EOF_N;1324 1325 lport->tt.frame_send(lport, fp);1326 }1327}1328 1329/**1330 * fc_exch_send_ba_rjt() - Send BLS Reject1331 * @rx_fp: The frame being rejected1332 * @reason: The reason the frame is being rejected1333 * @explan: The explanation for the rejection1334 *1335 * This is for rejecting BA_ABTS only.1336 */1337static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,1338 enum fc_ba_rjt_reason reason,1339 enum fc_ba_rjt_explan explan)1340{1341 struct fc_frame *fp;1342 struct fc_frame_header *rx_fh;1343 struct fc_frame_header *fh;1344 struct fc_ba_rjt *rp;1345 struct fc_seq *sp;1346 struct fc_lport *lport;1347 unsigned int f_ctl;1348 1349 lport = fr_dev(rx_fp);1350 sp = fr_seq(rx_fp);1351 fp = fc_frame_alloc(lport, sizeof(*rp));1352 if (!fp) {1353 FC_EXCH_DBG(fc_seq_exch(sp),1354 "Drop BA_RJT request, out of memory\n");1355 return;1356 }1357 fh = fc_frame_header_get(fp);1358 rx_fh = fc_frame_header_get(rx_fp);1359 1360 memset(fh, 0, sizeof(*fh) + sizeof(*rp));1361 1362 rp = fc_frame_payload_get(fp, sizeof(*rp));1363 rp->br_reason = reason;1364 rp->br_explan = explan;1365 1366 /*1367 * seq_id, cs_ctl, df_ctl and param/offset are zero.1368 */1369 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);1370 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);1371 fh->fh_ox_id = rx_fh->fh_ox_id;1372 fh->fh_rx_id = rx_fh->fh_rx_id;1373 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;1374 fh->fh_r_ctl = FC_RCTL_BA_RJT;1375 fh->fh_type = FC_TYPE_BLS;1376 1377 /*1378 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).1379 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.1380 * Bits 9-8 are meaningful (retransmitted or unidirectional).1381 * Last ACK uses bits 7-6 (continue sequence),1382 * bits 5-4 are meaningful (what kind of ACK to use).1383 * Always set LAST_SEQ, END_SEQ.1384 */1385 f_ctl = ntoh24(rx_fh->fh_f_ctl);1386 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |1387 FC_FC_END_CONN | FC_FC_SEQ_INIT |1388 FC_FC_RETX_SEQ | FC_FC_UNI_TX;1389 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;1390 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;1391 f_ctl &= ~FC_FC_FIRST_SEQ;1392 hton24(fh->fh_f_ctl, f_ctl);1393 1394 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));1395 fr_eof(fp) = FC_EOF_T;1396 if (fc_sof_needs_ack(fr_sof(fp)))1397 fr_eof(fp) = FC_EOF_N;1398 1399 lport->tt.frame_send(lport, fp);1400}1401 1402/**1403 * fc_exch_recv_abts() - Handle an incoming ABTS1404 * @ep: The exchange the abort was on1405 * @rx_fp: The ABTS frame1406 *1407 * This would be for target mode usually, but could be due to lost1408 * FCP transfer ready, confirm or RRQ. We always handle this as an1409 * exchange abort, ignoring the parameter.1410 */1411static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)1412{1413 struct fc_frame *fp;1414 struct fc_ba_acc *ap;1415 struct fc_frame_header *fh;1416 struct fc_seq *sp;1417 1418 if (!ep)1419 goto reject;1420 1421 FC_EXCH_DBG(ep, "exch: ABTS received\n");1422 fp = fc_frame_alloc(ep->lp, sizeof(*ap));1423 if (!fp) {1424 FC_EXCH_DBG(ep, "Drop ABTS request, out of memory\n");1425 goto free;1426 }1427 1428 spin_lock_bh(&ep->ex_lock);1429 if (ep->esb_stat & ESB_ST_COMPLETE) {1430 spin_unlock_bh(&ep->ex_lock);1431 FC_EXCH_DBG(ep, "exch: ABTS rejected, exchange complete\n");1432 fc_frame_free(fp);1433 goto reject;1434 }1435 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {1436 ep->esb_stat |= ESB_ST_REC_QUAL;1437 fc_exch_hold(ep); /* hold for REC_QUAL */1438 }1439 fc_exch_timer_set_locked(ep, ep->r_a_tov);1440 fh = fc_frame_header_get(fp);1441 ap = fc_frame_payload_get(fp, sizeof(*ap));1442 memset(ap, 0, sizeof(*ap));1443 sp = &ep->seq;1444 ap->ba_high_seq_cnt = htons(0xffff);1445 if (sp->ssb_stat & SSB_ST_RESP) {1446 ap->ba_seq_id = sp->id;1447 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;1448 ap->ba_high_seq_cnt = fh->fh_seq_cnt;1449 ap->ba_low_seq_cnt = htons(sp->cnt);1450 }1451 sp = fc_seq_start_next_locked(sp);1452 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);1453 ep->esb_stat |= ESB_ST_ABNORMAL;1454 spin_unlock_bh(&ep->ex_lock);1455 1456free:1457 fc_frame_free(rx_fp);1458 return;1459 1460reject:1461 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);1462 goto free;1463}1464 1465/**1466 * fc_seq_assign() - Assign exchange and sequence for incoming request1467 * @lport: The local port that received the request1468 * @fp: The request frame1469 *1470 * On success, the sequence pointer will be returned and also in fr_seq(@fp).1471 * A reference will be held on the exchange/sequence for the caller, which1472 * must call fc_seq_release().1473 */1474struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)1475{1476 struct fc_exch_mgr_anchor *ema;1477 1478 WARN_ON(lport != fr_dev(fp));1479 WARN_ON(fr_seq(fp));1480 fr_seq(fp) = NULL;1481 1482 list_for_each_entry(ema, &lport->ema_list, ema_list)1483 if ((!ema->match || ema->match(fp)) &&1484 fc_seq_lookup_recip(lport, ema->mp, fp) == FC_RJT_NONE)1485 break;1486 return fr_seq(fp);1487}1488EXPORT_SYMBOL(fc_seq_assign);1489 1490/**1491 * fc_seq_release() - Release the hold1492 * @sp: The sequence.1493 */1494void fc_seq_release(struct fc_seq *sp)1495{1496 fc_exch_release(fc_seq_exch(sp));1497}1498EXPORT_SYMBOL(fc_seq_release);1499 1500/**1501 * fc_exch_recv_req() - Handler for an incoming request1502 * @lport: The local port that received the request1503 * @mp: The EM that the exchange is on1504 * @fp: The request frame1505 *1506 * This is used when the other end is originating the exchange1507 * and the sequence.1508 */1509static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp,1510 struct fc_frame *fp)1511{1512 struct fc_frame_header *fh = fc_frame_header_get(fp);1513 struct fc_seq *sp = NULL;1514 struct fc_exch *ep = NULL;1515 enum fc_pf_rjt_reason reject;1516 1517 /* We can have the wrong fc_lport at this point with NPIV, which is a1518 * problem now that we know a new exchange needs to be allocated1519 */1520 lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id));1521 if (!lport) {1522 fc_frame_free(fp);1523 return;1524 }1525 fr_dev(fp) = lport;1526 1527 BUG_ON(fr_seq(fp)); /* XXX remove later */1528 1529 /*1530 * If the RX_ID is 0xffff, don't allocate an exchange.1531 * The upper-level protocol may request one later, if needed.1532 */1533 if (fh->fh_rx_id == htons(FC_XID_UNKNOWN))1534 return fc_lport_recv(lport, fp);1535 1536 reject = fc_seq_lookup_recip(lport, mp, fp);1537 if (reject == FC_RJT_NONE) {1538 sp = fr_seq(fp); /* sequence will be held */1539 ep = fc_seq_exch(sp);1540 fc_seq_send_ack(sp, fp);1541 ep->encaps = fr_encaps(fp);1542 1543 /*1544 * Call the receive function.1545 *1546 * The receive function may allocate a new sequence1547 * over the old one, so we shouldn't change the1548 * sequence after this.1549 *1550 * The frame will be freed by the receive function.1551 * If new exch resp handler is valid then call that1552 * first.1553 */1554 if (!fc_invoke_resp(ep, sp, fp))1555 fc_lport_recv(lport, fp);1556 fc_exch_release(ep); /* release from lookup */1557 } else {1558 FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n",1559 reject);1560 fc_frame_free(fp);1561 }1562}1563 1564/**1565 * fc_exch_recv_seq_resp() - Handler for an incoming response where the other1566 * end is the originator of the sequence that is a1567 * response to our initial exchange1568 * @mp: The EM that the exchange is on1569 * @fp: The response frame1570 */1571static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)1572{1573 struct fc_frame_header *fh = fc_frame_header_get(fp);1574 struct fc_seq *sp;1575 struct fc_exch *ep;1576 enum fc_sof sof;1577 u32 f_ctl;1578 int rc;1579 1580 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));1581 if (!ep) {1582 atomic_inc(&mp->stats.xid_not_found);1583 goto out;1584 }1585 if (ep->esb_stat & ESB_ST_COMPLETE) {1586 atomic_inc(&mp->stats.xid_not_found);1587 goto rel;1588 }1589 if (ep->rxid == FC_XID_UNKNOWN)1590 ep->rxid = ntohs(fh->fh_rx_id);1591 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {1592 atomic_inc(&mp->stats.xid_not_found);1593 goto rel;1594 }1595 if (ep->did != ntoh24(fh->fh_s_id) &&1596 ep->did != FC_FID_FLOGI) {1597 atomic_inc(&mp->stats.xid_not_found);1598 goto rel;1599 }1600 sof = fr_sof(fp);1601 sp = &ep->seq;1602 if (fc_sof_is_init(sof)) {1603 sp->ssb_stat |= SSB_ST_RESP;1604 sp->id = fh->fh_seq_id;1605 }1606 1607 f_ctl = ntoh24(fh->fh_f_ctl);1608 fr_seq(fp) = sp;1609 1610 spin_lock_bh(&ep->ex_lock);1611 if (f_ctl & FC_FC_SEQ_INIT)1612 ep->esb_stat |= ESB_ST_SEQ_INIT;1613 spin_unlock_bh(&ep->ex_lock);1614 1615 if (fc_sof_needs_ack(sof))1616 fc_seq_send_ack(sp, fp);1617 1618 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&1619 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==1620 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {1621 spin_lock_bh(&ep->ex_lock);1622 rc = fc_exch_done_locked(ep);1623 WARN_ON(fc_seq_exch(sp) != ep);1624 spin_unlock_bh(&ep->ex_lock);1625 if (!rc) {1626 fc_exch_delete(ep);1627 } else {1628 FC_EXCH_DBG(ep, "ep is completed already,"1629 "hence skip calling the resp\n");1630 goto skip_resp;1631 }1632 }1633 1634 /*1635 * Call the receive function.1636 * The sequence is held (has a refcnt) for us,1637 * but not for the receive function.1638 *1639 * The receive function may allocate a new sequence1640 * over the old one, so we shouldn't change the1641 * sequence after this.1642 *1643 * The frame will be freed by the receive function.1644 * If new exch resp handler is valid then call that1645 * first.1646 */1647 if (!fc_invoke_resp(ep, sp, fp))1648 fc_frame_free(fp);1649 1650skip_resp:1651 fc_exch_release(ep);1652 return;1653rel:1654 fc_exch_release(ep);1655out:1656 fc_frame_free(fp);1657}1658 1659/**1660 * fc_exch_recv_resp() - Handler for a sequence where other end is1661 * responding to our sequence1662 * @mp: The EM that the exchange is on1663 * @fp: The response frame1664 */1665static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)1666{1667 struct fc_seq *sp;1668 1669 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */1670 1671 if (!sp)1672 atomic_inc(&mp->stats.xid_not_found);1673 else1674 atomic_inc(&mp->stats.non_bls_resp);1675 1676 fc_frame_free(fp);1677}1678 1679/**1680 * fc_exch_abts_resp() - Handler for a response to an ABT1681 * @ep: The exchange that the frame is on1682 * @fp: The response frame1683 *1684 * This response would be to an ABTS cancelling an exchange or sequence.1685 * The response can be either BA_ACC or BA_RJT1686 */1687static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)1688{1689 struct fc_frame_header *fh;1690 struct fc_ba_acc *ap;1691 struct fc_seq *sp;1692 u16 low;1693 u16 high;1694 int rc = 1, has_rec = 0;1695 1696 fh = fc_frame_header_get(fp);1697 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,1698 fc_exch_rctl_name(fh->fh_r_ctl));1699 1700 if (cancel_delayed_work_sync(&ep->timeout_work)) {1701 FC_EXCH_DBG(ep, "Exchange timer canceled due to ABTS response\n");1702 fc_exch_release(ep); /* release from pending timer hold */1703 return;1704 }1705 1706 spin_lock_bh(&ep->ex_lock);1707 switch (fh->fh_r_ctl) {1708 case FC_RCTL_BA_ACC:1709 ap = fc_frame_payload_get(fp, sizeof(*ap));1710 if (!ap)1711 break;1712 1713 /*1714 * Decide whether to establish a Recovery Qualifier.1715 * We do this if there is a non-empty SEQ_CNT range and1716 * SEQ_ID is the same as the one we aborted.1717 */1718 low = ntohs(ap->ba_low_seq_cnt);1719 high = ntohs(ap->ba_high_seq_cnt);1720 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&1721 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||1722 ap->ba_seq_id == ep->seq_id) && low != high) {1723 ep->esb_stat |= ESB_ST_REC_QUAL;1724 fc_exch_hold(ep); /* hold for recovery qualifier */1725 has_rec = 1;1726 }1727 break;1728 case FC_RCTL_BA_RJT:1729 break;1730 default:1731 break;1732 }1733 1734 /* do we need to do some other checks here. Can we reuse more of1735 * fc_exch_recv_seq_resp1736 */1737 sp = &ep->seq;1738 /*1739 * do we want to check END_SEQ as well as LAST_SEQ here?1740 */1741 if (ep->fh_type != FC_TYPE_FCP &&1742 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)1743 rc = fc_exch_done_locked(ep);1744 spin_unlock_bh(&ep->ex_lock);1745 1746 fc_exch_hold(ep);1747 if (!rc)1748 fc_exch_delete(ep);1749 if (!fc_invoke_resp(ep, sp, fp))1750 fc_frame_free(fp);1751 if (has_rec)1752 fc_exch_timer_set(ep, ep->r_a_tov);1753 fc_exch_release(ep);1754}1755 1756/**1757 * fc_exch_recv_bls() - Handler for a BLS sequence1758 * @mp: The EM that the exchange is on1759 * @fp: The request frame1760 *1761 * The BLS frame is always a sequence initiated by the remote side.1762 * We may be either the originator or recipient of the exchange.1763 */1764static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)1765{1766 struct fc_frame_header *fh;1767 struct fc_exch *ep;1768 u32 f_ctl;1769 1770 fh = fc_frame_header_get(fp);1771 f_ctl = ntoh24(fh->fh_f_ctl);1772 fr_seq(fp) = NULL;1773 1774 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?1775 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));1776 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {1777 spin_lock_bh(&ep->ex_lock);1778 ep->esb_stat |= ESB_ST_SEQ_INIT;1779 spin_unlock_bh(&ep->ex_lock);1780 }1781 if (f_ctl & FC_FC_SEQ_CTX) {1782 /*1783 * A response to a sequence we initiated.1784 * This should only be ACKs for class 2 or F.1785 */1786 switch (fh->fh_r_ctl) {1787 case FC_RCTL_ACK_1:1788 case FC_RCTL_ACK_0:1789 break;1790 default:1791 if (ep)1792 FC_EXCH_DBG(ep, "BLS rctl %x - %s received\n",1793 fh->fh_r_ctl,1794 fc_exch_rctl_name(fh->fh_r_ctl));1795 break;1796 }1797 fc_frame_free(fp);1798 } else {1799 switch (fh->fh_r_ctl) {1800 case FC_RCTL_BA_RJT:1801 case FC_RCTL_BA_ACC:1802 if (ep)1803 fc_exch_abts_resp(ep, fp);1804 else1805 fc_frame_free(fp);1806 break;1807 case FC_RCTL_BA_ABTS:1808 if (ep)1809 fc_exch_recv_abts(ep, fp);1810 else1811 fc_frame_free(fp);1812 break;1813 default: /* ignore junk */1814 fc_frame_free(fp);1815 break;1816 }1817 }1818 if (ep)1819 fc_exch_release(ep); /* release hold taken by fc_exch_find */1820}1821 1822/**1823 * fc_seq_ls_acc() - Accept sequence with LS_ACC1824 * @rx_fp: The received frame, not freed here.1825 *1826 * If this fails due to allocation or transmit congestion, assume the1827 * originator will repeat the sequence.1828 */1829static void fc_seq_ls_acc(struct fc_frame *rx_fp)1830{1831 struct fc_lport *lport;1832 struct fc_els_ls_acc *acc;1833 struct fc_frame *fp;1834 struct fc_seq *sp;1835 1836 lport = fr_dev(rx_fp);1837 sp = fr_seq(rx_fp);1838 fp = fc_frame_alloc(lport, sizeof(*acc));1839 if (!fp) {1840 FC_EXCH_DBG(fc_seq_exch(sp),1841 "exch: drop LS_ACC, out of memory\n");1842 return;1843 }1844 acc = fc_frame_payload_get(fp, sizeof(*acc));1845 memset(acc, 0, sizeof(*acc));1846 acc->la_cmd = ELS_LS_ACC;1847 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);1848 lport->tt.frame_send(lport, fp);1849}1850 1851/**1852 * fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT1853 * @rx_fp: The received frame, not freed here.1854 * @reason: The reason the sequence is being rejected1855 * @explan: The explanation for the rejection1856 *1857 * If this fails due to allocation or transmit congestion, assume the1858 * originator will repeat the sequence.1859 */1860static void fc_seq_ls_rjt(struct fc_frame *rx_fp, enum fc_els_rjt_reason reason,1861 enum fc_els_rjt_explan explan)1862{1863 struct fc_lport *lport;1864 struct fc_els_ls_rjt *rjt;1865 struct fc_frame *fp;1866 struct fc_seq *sp;1867 1868 lport = fr_dev(rx_fp);1869 sp = fr_seq(rx_fp);1870 fp = fc_frame_alloc(lport, sizeof(*rjt));1871 if (!fp) {1872 FC_EXCH_DBG(fc_seq_exch(sp),1873 "exch: drop LS_ACC, out of memory\n");1874 return;1875 }1876 rjt = fc_frame_payload_get(fp, sizeof(*rjt));1877 memset(rjt, 0, sizeof(*rjt));1878 rjt->er_cmd = ELS_LS_RJT;1879 rjt->er_reason = reason;1880 rjt->er_explan = explan;1881 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);1882 lport->tt.frame_send(lport, fp);1883}1884 1885/**1886 * fc_exch_reset() - Reset an exchange1887 * @ep: The exchange to be reset1888 *1889 * Note: May sleep if invoked from outside a response handler.1890 */1891static void fc_exch_reset(struct fc_exch *ep)1892{1893 struct fc_seq *sp;1894 int rc = 1;1895 1896 spin_lock_bh(&ep->ex_lock);1897 ep->state |= FC_EX_RST_CLEANUP;1898 fc_exch_timer_cancel(ep);1899 if (ep->esb_stat & ESB_ST_REC_QUAL)1900 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */1901 ep->esb_stat &= ~ESB_ST_REC_QUAL;1902 sp = &ep->seq;1903 rc = fc_exch_done_locked(ep);1904 spin_unlock_bh(&ep->ex_lock);1905 1906 fc_exch_hold(ep);1907 1908 if (!rc) {1909 fc_exch_delete(ep);1910 } else {1911 FC_EXCH_DBG(ep, "ep is completed already,"1912 "hence skip calling the resp\n");1913 goto skip_resp;1914 }1915 1916 fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_CLOSED));1917skip_resp:1918 fc_seq_set_resp(sp, NULL, ep->arg);1919 fc_exch_release(ep);1920}1921 1922/**1923 * fc_exch_pool_reset() - Reset a per cpu exchange pool1924 * @lport: The local port that the exchange pool is on1925 * @pool: The exchange pool to be reset1926 * @sid: The source ID1927 * @did: The destination ID1928 *1929 * Resets a per cpu exches pool, releasing all of its sequences1930 * and exchanges. If sid is non-zero then reset only exchanges1931 * we sourced from the local port's FID. If did is non-zero then1932 * only reset exchanges destined for the local port's FID.1933 */1934static void fc_exch_pool_reset(struct fc_lport *lport,1935 struct fc_exch_pool *pool,1936 u32 sid, u32 did)1937{1938 struct fc_exch *ep;1939 struct fc_exch *next;1940 1941 spin_lock_bh(&pool->lock);1942restart:1943 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {1944 if ((lport == ep->lp) &&1945 (sid == 0 || sid == ep->sid) &&1946 (did == 0 || did == ep->did)) {1947 fc_exch_hold(ep);1948 spin_unlock_bh(&pool->lock);1949 1950 fc_exch_reset(ep);1951 1952 fc_exch_release(ep);1953 spin_lock_bh(&pool->lock);1954 1955 /*1956 * must restart loop incase while lock1957 * was down multiple eps were released.1958 */1959 goto restart;1960 }1961 }1962 pool->next_index = 0;1963 pool->left = FC_XID_UNKNOWN;1964 pool->right = FC_XID_UNKNOWN;1965 spin_unlock_bh(&pool->lock);1966}1967 1968/**1969 * fc_exch_mgr_reset() - Reset all EMs of a local port1970 * @lport: The local port whose EMs are to be reset1971 * @sid: The source ID1972 * @did: The destination ID1973 *1974 * Reset all EMs associated with a given local port. Release all1975 * sequences and exchanges. If sid is non-zero then reset only the1976 * exchanges sent from the local port's FID. If did is non-zero then1977 * reset only exchanges destined for the local port's FID.1978 */1979void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)1980{1981 struct fc_exch_mgr_anchor *ema;1982 unsigned int cpu;1983 1984 list_for_each_entry(ema, &lport->ema_list, ema_list) {1985 for_each_possible_cpu(cpu)1986 fc_exch_pool_reset(lport,1987 per_cpu_ptr(ema->mp->pool, cpu),1988 sid, did);1989 }1990}1991EXPORT_SYMBOL(fc_exch_mgr_reset);1992 1993/**1994 * fc_exch_lookup() - find an exchange1995 * @lport: The local port1996 * @xid: The exchange ID1997 *1998 * Returns exchange pointer with hold for caller, or NULL if not found.1999 */2000static struct fc_exch *fc_exch_lookup(struct fc_lport *lport, u32 xid)2001{2002 struct fc_exch_mgr_anchor *ema;2003 2004 list_for_each_entry(ema, &lport->ema_list, ema_list)2005 if (ema->mp->min_xid <= xid && xid <= ema->mp->max_xid)2006 return fc_exch_find(ema->mp, xid);2007 return NULL;2008}2009 2010/**2011 * fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests2012 * @rfp: The REC frame, not freed here.2013 *2014 * Note that the requesting port may be different than the S_ID in the request.2015 */2016static void fc_exch_els_rec(struct fc_frame *rfp)2017{2018 struct fc_lport *lport;2019 struct fc_frame *fp;2020 struct fc_exch *ep;2021 struct fc_els_rec *rp;2022 struct fc_els_rec_acc *acc;2023 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;2024 enum fc_els_rjt_explan explan;2025 u32 sid;2026 u16 xid, rxid, oxid;2027 2028 lport = fr_dev(rfp);2029 rp = fc_frame_payload_get(rfp, sizeof(*rp));2030 explan = ELS_EXPL_INV_LEN;2031 if (!rp)2032 goto reject;2033 sid = ntoh24(rp->rec_s_id);2034 rxid = ntohs(rp->rec_rx_id);2035 oxid = ntohs(rp->rec_ox_id);2036 2037 explan = ELS_EXPL_OXID_RXID;2038 if (sid == fc_host_port_id(lport->host))2039 xid = oxid;2040 else2041 xid = rxid;2042 if (xid == FC_XID_UNKNOWN) {2043 FC_LPORT_DBG(lport,2044 "REC request from %x: invalid rxid %x oxid %x\n",2045 sid, rxid, oxid);2046 goto reject;2047 }2048 ep = fc_exch_lookup(lport, xid);2049 if (!ep) {2050 FC_LPORT_DBG(lport,2051 "REC request from %x: rxid %x oxid %x not found\n",2052 sid, rxid, oxid);2053 goto reject;2054 }2055 FC_EXCH_DBG(ep, "REC request from %x: rxid %x oxid %x\n",2056 sid, rxid, oxid);2057 if (ep->oid != sid || oxid != ep->oxid)2058 goto rel;2059 if (rxid != FC_XID_UNKNOWN && rxid != ep->rxid)2060 goto rel;2061 fp = fc_frame_alloc(lport, sizeof(*acc));2062 if (!fp) {2063 FC_EXCH_DBG(ep, "Drop REC request, out of memory\n");2064 goto out;2065 }2066 2067 acc = fc_frame_payload_get(fp, sizeof(*acc));2068 memset(acc, 0, sizeof(*acc));2069 acc->reca_cmd = ELS_LS_ACC;2070 acc->reca_ox_id = rp->rec_ox_id;2071 memcpy(acc->reca_ofid, rp->rec_s_id, 3);2072 acc->reca_rx_id = htons(ep->rxid);2073 if (ep->sid == ep->oid)2074 hton24(acc->reca_rfid, ep->did);2075 else2076 hton24(acc->reca_rfid, ep->sid);2077 acc->reca_fc4value = htonl(ep->seq.rec_data);2078 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |2079 ESB_ST_SEQ_INIT |2080 ESB_ST_COMPLETE));2081 fc_fill_reply_hdr(fp, rfp, FC_RCTL_ELS_REP, 0);2082 lport->tt.frame_send(lport, fp);2083out:2084 fc_exch_release(ep);2085 return;2086 2087rel:2088 fc_exch_release(ep);2089reject:2090 fc_seq_ls_rjt(rfp, reason, explan);2091}2092 2093/**2094 * fc_exch_rrq_resp() - Handler for RRQ responses2095 * @sp: The sequence that the RRQ is on2096 * @fp: The RRQ frame2097 * @arg: The exchange that the RRQ is on2098 *2099 * TODO: fix error handler.2100 */2101static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)2102{2103 struct fc_exch *aborted_ep = arg;2104 unsigned int op;2105 2106 if (IS_ERR(fp)) {2107 int err = PTR_ERR(fp);2108 2109 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)2110 goto cleanup;2111 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "2112 "frame error %d\n", err);2113 return;2114 }2115 2116 op = fc_frame_payload_op(fp);2117 fc_frame_free(fp);2118 2119 switch (op) {2120 case ELS_LS_RJT:2121 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ\n");2122 fallthrough;2123 case ELS_LS_ACC:2124 goto cleanup;2125 default:2126 FC_EXCH_DBG(aborted_ep, "unexpected response op %x for RRQ\n",2127 op);2128 return;2129 }2130 2131cleanup:2132 fc_exch_done(&aborted_ep->seq);2133 /* drop hold for rec qual */2134 fc_exch_release(aborted_ep);2135}2136 2137 2138/**2139 * fc_exch_seq_send() - Send a frame using a new exchange and sequence2140 * @lport: The local port to send the frame on2141 * @fp: The frame to be sent2142 * @resp: The response handler for this request2143 * @destructor: The destructor for the exchange2144 * @arg: The argument to be passed to the response handler2145 * @timer_msec: The timeout period for the exchange2146 *2147 * The exchange response handler is set in this routine to resp()2148 * function pointer. It can be called in two scenarios: if a timeout2149 * occurs or if a response frame is received for the exchange. The2150 * fc_frame pointer in response handler will also indicate timeout2151 * as error using IS_ERR related macros.2152 *2153 * The exchange destructor handler is also set in this routine.2154 * The destructor handler is invoked by EM layer when exchange2155 * is about to free, this can be used by caller to free its2156 * resources along with exchange free.2157 *2158 * The arg is passed back to resp and destructor handler.2159 *2160 * The timeout value (in msec) for an exchange is set if non zero2161 * timer_msec argument is specified. The timer is canceled when2162 * it fires or when the exchange is done. The exchange timeout handler2163 * is registered by EM layer.2164 *2165 * The frame pointer with some of the header's fields must be2166 * filled before calling this routine, those fields are:2167 *2168 * - routing control2169 * - FC port did2170 * - FC port sid2171 * - FC header type2172 * - frame control2173 * - parameter or relative offset2174 */2175struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,2176 struct fc_frame *fp,2177 void (*resp)(struct fc_seq *,2178 struct fc_frame *fp,2179 void *arg),2180 void (*destructor)(struct fc_seq *, void *),2181 void *arg, u32 timer_msec)2182{2183 struct fc_exch *ep;2184 struct fc_seq *sp = NULL;2185 struct fc_frame_header *fh;2186 struct fc_fcp_pkt *fsp = NULL;2187 int rc = 1;2188 2189 ep = fc_exch_alloc(lport, fp);2190 if (!ep) {2191 fc_frame_free(fp);2192 return NULL;2193 }2194 ep->esb_stat |= ESB_ST_SEQ_INIT;2195 fh = fc_frame_header_get(fp);2196 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));2197 ep->resp = resp;2198 ep->destructor = destructor;2199 ep->arg = arg;2200 ep->r_a_tov = lport->r_a_tov;2201 ep->lp = lport;2202 sp = &ep->seq;2203 2204 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */2205 ep->f_ctl = ntoh24(fh->fh_f_ctl);2206 fc_exch_setup_hdr(ep, fp, ep->f_ctl);2207 sp->cnt++;2208 2209 if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD) {2210 fsp = fr_fsp(fp);2211 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);2212 }2213 2214 if (unlikely(lport->tt.frame_send(lport, fp)))2215 goto err;2216 2217 if (timer_msec)2218 fc_exch_timer_set_locked(ep, timer_msec);2219 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */2220 2221 if (ep->f_ctl & FC_FC_SEQ_INIT)2222 ep->esb_stat &= ~ESB_ST_SEQ_INIT;2223 spin_unlock_bh(&ep->ex_lock);2224 return sp;2225err:2226 if (fsp)2227 fc_fcp_ddp_done(fsp);2228 rc = fc_exch_done_locked(ep);2229 spin_unlock_bh(&ep->ex_lock);2230 if (!rc)2231 fc_exch_delete(ep);2232 return NULL;2233}2234EXPORT_SYMBOL(fc_exch_seq_send);2235 2236/**2237 * fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command2238 * @ep: The exchange to send the RRQ on2239 *2240 * This tells the remote port to stop blocking the use of2241 * the exchange and the seq_cnt range.2242 */2243static void fc_exch_rrq(struct fc_exch *ep)2244{2245 struct fc_lport *lport;2246 struct fc_els_rrq *rrq;2247 struct fc_frame *fp;2248 u32 did;2249 2250 lport = ep->lp;2251 2252 fp = fc_frame_alloc(lport, sizeof(*rrq));2253 if (!fp)2254 goto retry;2255 2256 rrq = fc_frame_payload_get(fp, sizeof(*rrq));2257 memset(rrq, 0, sizeof(*rrq));2258 rrq->rrq_cmd = ELS_RRQ;2259 hton24(rrq->rrq_s_id, ep->sid);2260 rrq->rrq_ox_id = htons(ep->oxid);2261 rrq->rrq_rx_id = htons(ep->rxid);2262 2263 did = ep->did;2264 if (ep->esb_stat & ESB_ST_RESP)2265 did = ep->sid;2266 2267 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,2268 lport->port_id, FC_TYPE_ELS,2269 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);2270 2271 if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep,2272 lport->e_d_tov))2273 return;2274 2275retry:2276 FC_EXCH_DBG(ep, "exch: RRQ send failed\n");2277 spin_lock_bh(&ep->ex_lock);2278 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {2279 spin_unlock_bh(&ep->ex_lock);2280 /* drop hold for rec qual */2281 fc_exch_release(ep);2282 return;2283 }2284 ep->esb_stat |= ESB_ST_REC_QUAL;2285 fc_exch_timer_set_locked(ep, ep->r_a_tov);2286 spin_unlock_bh(&ep->ex_lock);2287}2288 2289/**2290 * fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests2291 * @fp: The RRQ frame, not freed here.2292 */2293static void fc_exch_els_rrq(struct fc_frame *fp)2294{2295 struct fc_lport *lport;2296 struct fc_exch *ep = NULL; /* request or subject exchange */2297 struct fc_els_rrq *rp;2298 u32 sid;2299 u16 xid;2300 enum fc_els_rjt_explan explan;2301 2302 lport = fr_dev(fp);2303 rp = fc_frame_payload_get(fp, sizeof(*rp));2304 explan = ELS_EXPL_INV_LEN;2305 if (!rp)2306 goto reject;2307 2308 /*2309 * lookup subject exchange.2310 */2311 sid = ntoh24(rp->rrq_s_id); /* subject source */2312 xid = fc_host_port_id(lport->host) == sid ?2313 ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);2314 ep = fc_exch_lookup(lport, xid);2315 explan = ELS_EXPL_OXID_RXID;2316 if (!ep)2317 goto reject;2318 spin_lock_bh(&ep->ex_lock);2319 FC_EXCH_DBG(ep, "RRQ request from %x: xid %x rxid %x oxid %x\n",2320 sid, xid, ntohs(rp->rrq_rx_id), ntohs(rp->rrq_ox_id));2321 if (ep->oxid != ntohs(rp->rrq_ox_id))2322 goto unlock_reject;2323 if (ep->rxid != ntohs(rp->rrq_rx_id) &&2324 ep->rxid != FC_XID_UNKNOWN)2325 goto unlock_reject;2326 explan = ELS_EXPL_SID;2327 if (ep->sid != sid)2328 goto unlock_reject;2329 2330 /*2331 * Clear Recovery Qualifier state, and cancel timer if complete.2332 */2333 if (ep->esb_stat & ESB_ST_REC_QUAL) {2334 ep->esb_stat &= ~ESB_ST_REC_QUAL;2335 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */2336 }2337 if (ep->esb_stat & ESB_ST_COMPLETE)2338 fc_exch_timer_cancel(ep);2339 2340 spin_unlock_bh(&ep->ex_lock);2341 2342 /*2343 * Send LS_ACC.2344 */2345 fc_seq_ls_acc(fp);2346 goto out;2347 2348unlock_reject:2349 spin_unlock_bh(&ep->ex_lock);2350reject:2351 fc_seq_ls_rjt(fp, ELS_RJT_LOGIC, explan);2352out:2353 if (ep)2354 fc_exch_release(ep); /* drop hold from fc_exch_find */2355}2356 2357/**2358 * fc_exch_update_stats() - update exches stats to lport2359 * @lport: The local port to update exchange manager stats2360 */2361void fc_exch_update_stats(struct fc_lport *lport)2362{2363 struct fc_host_statistics *st;2364 struct fc_exch_mgr_anchor *ema;2365 struct fc_exch_mgr *mp;2366 2367 st = &lport->host_stats;2368 2369 list_for_each_entry(ema, &lport->ema_list, ema_list) {2370 mp = ema->mp;2371 st->fc_no_free_exch += atomic_read(&mp->stats.no_free_exch);2372 st->fc_no_free_exch_xid +=2373 atomic_read(&mp->stats.no_free_exch_xid);2374 st->fc_xid_not_found += atomic_read(&mp->stats.xid_not_found);2375 st->fc_xid_busy += atomic_read(&mp->stats.xid_busy);2376 st->fc_seq_not_found += atomic_read(&mp->stats.seq_not_found);2377 st->fc_non_bls_resp += atomic_read(&mp->stats.non_bls_resp);2378 }2379}2380EXPORT_SYMBOL(fc_exch_update_stats);2381 2382/**2383 * fc_exch_mgr_add() - Add an exchange manager to a local port's list of EMs2384 * @lport: The local port to add the exchange manager to2385 * @mp: The exchange manager to be added to the local port2386 * @match: The match routine that indicates when this EM should be used2387 */2388struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,2389 struct fc_exch_mgr *mp,2390 bool (*match)(struct fc_frame *))2391{2392 struct fc_exch_mgr_anchor *ema;2393 2394 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);2395 if (!ema)2396 return ema;2397 2398 ema->mp = mp;2399 ema->match = match;2400 /* add EM anchor to EM anchors list */2401 list_add_tail(&ema->ema_list, &lport->ema_list);2402 kref_get(&mp->kref);2403 return ema;2404}2405EXPORT_SYMBOL(fc_exch_mgr_add);2406 2407/**2408 * fc_exch_mgr_destroy() - Destroy an exchange manager2409 * @kref: The reference to the EM to be destroyed2410 */2411static void fc_exch_mgr_destroy(struct kref *kref)2412{2413 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);2414 2415 mempool_destroy(mp->ep_pool);2416 free_percpu(mp->pool);2417 kfree(mp);2418}2419 2420/**2421 * fc_exch_mgr_del() - Delete an EM from a local port's list2422 * @ema: The exchange manager anchor identifying the EM to be deleted2423 */2424void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)2425{2426 /* remove EM anchor from EM anchors list */2427 list_del(&ema->ema_list);2428 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);2429 kfree(ema);2430}2431EXPORT_SYMBOL(fc_exch_mgr_del);2432 2433/**2434 * fc_exch_mgr_list_clone() - Share all exchange manager objects2435 * @src: Source lport to clone exchange managers from2436 * @dst: New lport that takes references to all the exchange managers2437 */2438int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)2439{2440 struct fc_exch_mgr_anchor *ema, *tmp;2441 2442 list_for_each_entry(ema, &src->ema_list, ema_list) {2443 if (!fc_exch_mgr_add(dst, ema->mp, ema->match))2444 goto err;2445 }2446 return 0;2447err:2448 list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)2449 fc_exch_mgr_del(ema);2450 return -ENOMEM;2451}2452EXPORT_SYMBOL(fc_exch_mgr_list_clone);2453 2454/**2455 * fc_exch_mgr_alloc() - Allocate an exchange manager2456 * @lport: The local port that the new EM will be associated with2457 * @class: The default FC class for new exchanges2458 * @min_xid: The minimum XID for exchanges from the new EM2459 * @max_xid: The maximum XID for exchanges from the new EM2460 * @match: The match routine for the new EM2461 */2462struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport,2463 enum fc_class class,2464 u16 min_xid, u16 max_xid,2465 bool (*match)(struct fc_frame *))2466{2467 struct fc_exch_mgr *mp;2468 u16 pool_exch_range;2469 size_t pool_size;2470 unsigned int cpu;2471 struct fc_exch_pool *pool;2472 2473 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||2474 (min_xid & fc_cpu_mask) != 0) {2475 FC_LPORT_DBG(lport, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",2476 min_xid, max_xid);2477 return NULL;2478 }2479 2480 /*2481 * allocate memory for EM2482 */2483 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);2484 if (!mp)2485 return NULL;2486 2487 mp->class = class;2488 mp->lport = lport;2489 /* adjust em exch xid range for offload */2490 mp->min_xid = min_xid;2491 2492 /* reduce range so per cpu pool fits into PCPU_MIN_UNIT_SIZE pool */2493 pool_exch_range = (PCPU_MIN_UNIT_SIZE - sizeof(*pool)) /2494 sizeof(struct fc_exch *);2495 if ((max_xid - min_xid + 1) / (fc_cpu_mask + 1) > pool_exch_range) {2496 mp->max_xid = pool_exch_range * (fc_cpu_mask + 1) +2497 min_xid - 1;2498 } else {2499 mp->max_xid = max_xid;2500 pool_exch_range = (mp->max_xid - mp->min_xid + 1) /2501 (fc_cpu_mask + 1);2502 }2503 2504 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);2505 if (!mp->ep_pool)2506 goto free_mp;2507 2508 /*2509 * Setup per cpu exch pool with entire exchange id range equally2510 * divided across all cpus. The exch pointers array memory is2511 * allocated for exch range per pool.2512 */2513 mp->pool_max_index = pool_exch_range - 1;2514 2515 /*2516 * Allocate and initialize per cpu exch pool2517 */2518 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);2519 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));2520 if (!mp->pool)2521 goto free_mempool;2522 for_each_possible_cpu(cpu) {2523 pool = per_cpu_ptr(mp->pool, cpu);2524 pool->next_index = 0;2525 pool->left = FC_XID_UNKNOWN;2526 pool->right = FC_XID_UNKNOWN;2527 spin_lock_init(&pool->lock);2528 INIT_LIST_HEAD(&pool->ex_list);2529 }2530 2531 kref_init(&mp->kref);2532 if (!fc_exch_mgr_add(lport, mp, match)) {2533 free_percpu(mp->pool);2534 goto free_mempool;2535 }2536 2537 /*2538 * Above kref_init() sets mp->kref to 1 and then2539 * call to fc_exch_mgr_add incremented mp->kref again,2540 * so adjust that extra increment.2541 */2542 kref_put(&mp->kref, fc_exch_mgr_destroy);2543 return mp;2544 2545free_mempool:2546 mempool_destroy(mp->ep_pool);2547free_mp:2548 kfree(mp);2549 return NULL;2550}2551EXPORT_SYMBOL(fc_exch_mgr_alloc);2552 2553/**2554 * fc_exch_mgr_free() - Free all exchange managers on a local port2555 * @lport: The local port whose EMs are to be freed2556 */2557void fc_exch_mgr_free(struct fc_lport *lport)2558{2559 struct fc_exch_mgr_anchor *ema, *next;2560 2561 flush_workqueue(fc_exch_workqueue);2562 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)2563 fc_exch_mgr_del(ema);2564}2565EXPORT_SYMBOL(fc_exch_mgr_free);2566 2567/**2568 * fc_find_ema() - Lookup and return appropriate Exchange Manager Anchor depending2569 * upon 'xid'.2570 * @f_ctl: f_ctl2571 * @lport: The local port the frame was received on2572 * @fh: The received frame header2573 */2574static struct fc_exch_mgr_anchor *fc_find_ema(u32 f_ctl,2575 struct fc_lport *lport,2576 struct fc_frame_header *fh)2577{2578 struct fc_exch_mgr_anchor *ema;2579 u16 xid;2580 2581 if (f_ctl & FC_FC_EX_CTX)2582 xid = ntohs(fh->fh_ox_id);2583 else {2584 xid = ntohs(fh->fh_rx_id);2585 if (xid == FC_XID_UNKNOWN)2586 return list_entry(lport->ema_list.prev,2587 typeof(*ema), ema_list);2588 }2589 2590 list_for_each_entry(ema, &lport->ema_list, ema_list) {2591 if ((xid >= ema->mp->min_xid) &&2592 (xid <= ema->mp->max_xid))2593 return ema;2594 }2595 return NULL;2596}2597/**2598 * fc_exch_recv() - Handler for received frames2599 * @lport: The local port the frame was received on2600 * @fp: The received frame2601 */2602void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)2603{2604 struct fc_frame_header *fh = fc_frame_header_get(fp);2605 struct fc_exch_mgr_anchor *ema;2606 u32 f_ctl;2607 2608 /* lport lock ? */2609 if (!lport || lport->state == LPORT_ST_DISABLED) {2610 FC_LIBFC_DBG("Receiving frames for an lport that "2611 "has not been initialized correctly\n");2612 fc_frame_free(fp);2613 return;2614 }2615 2616 f_ctl = ntoh24(fh->fh_f_ctl);2617 ema = fc_find_ema(f_ctl, lport, fh);2618 if (!ema) {2619 FC_LPORT_DBG(lport, "Unable to find Exchange Manager Anchor,"2620 "fc_ctl <0x%x>, xid <0x%x>\n",2621 f_ctl,2622 (f_ctl & FC_FC_EX_CTX) ?2623 ntohs(fh->fh_ox_id) :2624 ntohs(fh->fh_rx_id));2625 fc_frame_free(fp);2626 return;2627 }2628 2629 /*2630 * If frame is marked invalid, just drop it.2631 */2632 switch (fr_eof(fp)) {2633 case FC_EOF_T:2634 if (f_ctl & FC_FC_END_SEQ)2635 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));2636 fallthrough;2637 case FC_EOF_N:2638 if (fh->fh_type == FC_TYPE_BLS)2639 fc_exch_recv_bls(ema->mp, fp);2640 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==2641 FC_FC_EX_CTX)2642 fc_exch_recv_seq_resp(ema->mp, fp);2643 else if (f_ctl & FC_FC_SEQ_CTX)2644 fc_exch_recv_resp(ema->mp, fp);2645 else /* no EX_CTX and no SEQ_CTX */2646 fc_exch_recv_req(lport, ema->mp, fp);2647 break;2648 default:2649 FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)",2650 fr_eof(fp));2651 fc_frame_free(fp);2652 }2653}2654EXPORT_SYMBOL(fc_exch_recv);2655 2656/**2657 * fc_exch_init() - Initialize the exchange layer for a local port2658 * @lport: The local port to initialize the exchange layer for2659 */2660int fc_exch_init(struct fc_lport *lport)2661{2662 if (!lport->tt.exch_mgr_reset)2663 lport->tt.exch_mgr_reset = fc_exch_mgr_reset;2664 2665 return 0;2666}2667EXPORT_SYMBOL(fc_exch_init);2668 2669/**2670 * fc_setup_exch_mgr() - Setup an exchange manager2671 */2672int fc_setup_exch_mgr(void)2673{2674 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),2675 0, SLAB_HWCACHE_ALIGN, NULL);2676 if (!fc_em_cachep)2677 return -ENOMEM;2678 2679 /*2680 * Initialize fc_cpu_mask and fc_cpu_order. The2681 * fc_cpu_mask is set for nr_cpu_ids rounded up2682 * to order of 2's * power and order is stored2683 * in fc_cpu_order as this is later required in2684 * mapping between an exch id and exch array index2685 * in per cpu exch pool.2686 *2687 * This round up is required to align fc_cpu_mask2688 * to exchange id's lower bits such that all incoming2689 * frames of an exchange gets delivered to the same2690 * cpu on which exchange originated by simple bitwise2691 * AND operation between fc_cpu_mask and exchange id.2692 */2693 fc_cpu_order = ilog2(roundup_pow_of_two(nr_cpu_ids));2694 fc_cpu_mask = (1 << fc_cpu_order) - 1;2695 2696 fc_exch_workqueue = alloc_ordered_workqueue("%s", WQ_MEM_RECLAIM,2697 "fc_exch_workqueue");2698 if (!fc_exch_workqueue)2699 goto err;2700 return 0;2701err:2702 kmem_cache_destroy(fc_em_cachep);2703 return -ENOMEM;2704}2705 2706/**2707 * fc_destroy_exch_mgr() - Destroy an exchange manager2708 */2709void fc_destroy_exch_mgr(void)2710{2711 destroy_workqueue(fc_exch_workqueue);2712 kmem_cache_destroy(fc_em_cachep);2713}2714