/* * Copyright(c) 2007 Intel Corporation. All rights reserved. * Copyright(c) 2008 Red Hat, Inc. All rights reserved. * Copyright(c) 2008 Mike Christie * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. * * Maintained at www.Open-FCoE.org */ /* * Fibre Channel exchange and sequence handling. */ #include <linux/timer.h> #include <linux/slab.h> #include <linux/err.h> #include <scsi/fc/fc_fc2.h> #include <scsi/libfc.h> #include <scsi/fc_encode.h> #include "fc_libfc.h" u16 fc_cpu_mask; /* cpu mask for possible cpus */ EXPORT_SYMBOL(fc_cpu_mask); static u16 fc_cpu_order; /* 2's power to represent total possible cpus */ static struct kmem_cache *fc_em_cachep; /* cache for exchanges */ static struct workqueue_struct *fc_exch_workqueue; /* * Structure and function definitions for managing Fibre Channel Exchanges * and Sequences. * * The three primary structures used here are fc_exch_mgr, fc_exch, and fc_seq. * * fc_exch_mgr holds the exchange state for an N port * * fc_exch holds state for one exchange and links to its active sequence. * * fc_seq holds the state for an individual sequence. */ /** * struct fc_exch_pool - Per cpu exchange pool * @next_index: Next possible free exchange index * @total_exches: Total allocated exchanges * @lock: Exch pool lock * @ex_list: List of exchanges * * This structure manages per cpu exchanges in array of exchange pointers. * This array is allocated followed by struct fc_exch_pool memory for * assigned range of exchanges to per cpu pool. */ struct fc_exch_pool { u16 next_index; u16 total_exches; /* two cache of free slot in exch array */ u16 left; u16 right; spinlock_t lock; struct list_head ex_list; }; /** * struct fc_exch_mgr - The Exchange Manager (EM). * @class: Default class for new sequences * @kref: Reference counter * @min_xid: Minimum exchange ID * @max_xid: Maximum exchange ID * @ep_pool: Reserved exchange pointers * @pool_max_index: Max exch array index in exch pool * @pool: Per cpu exch pool * @stats: Statistics structure * * This structure is the center for creating exchanges and sequences. * It manages the allocation of exchange IDs. */ struct fc_exch_mgr { enum fc_class class; struct kref kref; u16 min_xid; u16 max_xid; mempool_t *ep_pool; u16 pool_max_index; struct fc_exch_pool *pool; /* * currently exchange mgr stats are updated but not used. * either stats can be expose via sysfs or remove them * all together if not used XXX */ struct { atomic_t no_free_exch; atomic_t no_free_exch_xid; atomic_t xid_not_found; atomic_t xid_busy; atomic_t seq_not_found; atomic_t non_bls_resp; } stats; }; /** * struct fc_exch_mgr_anchor - primary structure for list of EMs * @ema_list: Exchange Manager Anchor list * @mp: Exchange Manager associated with this anchor * @match: Routine to determine if this anchor's EM should be used * * When walking the list of anchors the match routine will be called * for each anchor to determine if that EM should be used. The last * anchor in the list will always match to handle any exchanges not * handled by other EMs. The non-default EMs would be added to the * anchor list by HW that provides FCoE offloads. */ struct fc_exch_mgr_anchor { struct list_head ema_list; struct fc_exch_mgr *mp; bool (*match)(struct fc_frame *); }; static void fc_exch_rrq(struct fc_exch *); static void fc_seq_ls_acc(struct fc_frame *); static void fc_seq_ls_rjt(struct fc_frame *, enum fc_els_rjt_reason, enum fc_els_rjt_explan); static void fc_exch_els_rec(struct fc_frame *); static void fc_exch_els_rrq(struct fc_frame *); /* * Internal implementation notes. * * The exchange manager is one by default in libfc but LLD may choose * to have one per CPU. The sequence manager is one per exchange manager * and currently never separated. * * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field * assigned by the Sequence Initiator that shall be unique for a specific * D_ID and S_ID pair while the Sequence is open." Note that it isn't * qualified by exchange ID, which one might think it would be. * In practice this limits the number of open sequences and exchanges to 256 * per session. For most targets we could treat this limit as per exchange. * * The exchange and its sequence are freed when the last sequence is received. * It's possible for the remote port to leave an exchange open without * sending any sequences. * * Notes on reference counts: * * Exchanges are reference counted and exchange gets freed when the reference * count becomes zero. * * Timeouts: * Sequences are timed out for E_D_TOV and R_A_TOV. * * Sequence event handling: * * The following events may occur on initiator sequences: * * Send. * For now, the whole thing is sent. * Receive ACK * This applies only to class F. * The sequence is marked complete. * ULP completion. * The upper layer calls fc_exch_done() when done * with exchange and sequence tuple. * RX-inferred completion. * When we receive the next sequence on the same exchange, we can * retire the previous sequence ID. (XXX not implemented). * Timeout. * R_A_TOV frees the sequence ID. If we're waiting for ACK, * E_D_TOV causes abort and calls upper layer response handler * with FC_EX_TIMEOUT error. * Receive RJT * XXX defer. * Send ABTS * On timeout. * * The following events may occur on recipient sequences: * * Receive * Allocate sequence for first frame received. * Hold during receive handler. * Release when final frame received. * Keep status of last N of these for the ELS RES command. XXX TBD. * Receive ABTS * Deallocate sequence * Send RJT * Deallocate * * For now, we neglect conditions where only part of a sequence was * received or transmitted, or where out-of-order receipt is detected. */ /* * Locking notes: * * The EM code run in a per-CPU worker thread. * * To protect against concurrency between a worker thread code and timers, * sequence allocation and deallocation must be locked. * - exchange refcnt can be done atomicly without locks. * - sequence allocation must be locked by exch lock. * - If the EM pool lock and ex_lock must be taken at the same time, then the * EM pool lock must be taken before the ex_lock. */ /* * opcode names for debugging. */ static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT; /** * fc_exch_name_lookup() - Lookup name by opcode * @op: Opcode to be looked up * @table: Opcode/name table * @max_index: Index not to be exceeded * * This routine is used to determine a human-readable string identifying * a R_CTL opcode. */ static inline const char *fc_exch_name_lookup(unsigned int op, char **table, unsigned int max_index) { const char *name = NULL; if (op < max_index) name = table[op]; if (!name) name = "unknown"; return name; } /** * fc_exch_rctl_name() - Wrapper routine for fc_exch_name_lookup() * @op: The opcode to be looked up */ static const char *fc_exch_rctl_name(unsigned int op) { return fc_exch_name_lookup(op, fc_exch_rctl_names, ARRAY_SIZE(fc_exch_rctl_names)); } /** * fc_exch_hold() - Increment an exchange's reference count * @ep: Echange to be held */ static inline void fc_exch_hold(struct fc_exch *ep) { atomic_inc(&ep->ex_refcnt); } /** * fc_exch_setup_hdr() - Initialize a FC header by initializing some fields * and determine SOF and EOF. * @ep: The exchange to that will use the header * @fp: The frame whose header is to be modified * @f_ctl: F_CTL bits that will be used for the frame header * * The fields initialized by this routine are: fh_ox_id, fh_rx_id, * fh_seq_id, fh_seq_cnt and the SOF and EOF. */ static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp, u32 f_ctl) { struct fc_frame_header *fh = fc_frame_header_get(fp); u16 fill; fr_sof(fp) = ep->class; if (ep->seq.cnt) fr_sof(fp) = fc_sof_normal(ep->class); if (f_ctl & FC_FC_END_SEQ) { fr_eof(fp) = FC_EOF_T; if (fc_sof_needs_ack(ep->class)) fr_eof(fp) = FC_EOF_N; /* * From F_CTL. * The number of fill bytes to make the length a 4-byte * multiple is the low order 2-bits of the f_ctl. * The fill itself will have been cleared by the frame * allocation. * After this, the length will be even, as expected by * the transport. */ fill = fr_len(fp) & 3; if (fill) { fill = 4 - fill; /* TODO, this may be a problem with fragmented skb */ skb_put(fp_skb(fp), fill); hton24(fh->fh_f_ctl, f_ctl | fill); } } else { WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */ fr_eof(fp) = FC_EOF_N; } /* * Initialize remainig fh fields * from fc_fill_fc_hdr */ fh->fh_ox_id = htons(ep->oxid); fh->fh_rx_id = htons(ep->rxid); fh->fh_seq_id = ep->seq.id; fh->fh_seq_cnt = htons(ep->seq.cnt); } /** * fc_exch_release() - Decrement an exchange's reference count * @ep: Exchange to be released * * If the reference count reaches zero and the exchange is complete, * it is freed. */ static void fc_exch_release(struct fc_exch *ep) { struct fc_exch_mgr *mp; if (atomic_dec_and_test(&ep->ex_refcnt)) { mp = ep->em; if (ep->destructor) ep->destructor(&ep->seq, ep->arg); WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE)); mempool_free(ep, mp->ep_pool); } } /** * fc_exch_done_locked() - Complete an exchange with the exchange lock held * @ep: The exchange that is complete */ static int fc_exch_done_locked(struct fc_exch *ep) { int rc = 1; /* * We must check for completion in case there are two threads * tyring to complete this. But the rrq code will reuse the * ep, and in that case we only clear the resp and set it as * complete, so it can be reused by the timer to send the rrq. */ ep->resp = NULL; if (ep->state & FC_EX_DONE) return rc; ep->esb_stat |= ESB_ST_COMPLETE; if (!(ep->esb_stat & ESB_ST_REC_QUAL)) { ep->state |= FC_EX_DONE; if (cancel_delayed_work(&ep->timeout_work)) atomic_dec(&ep->ex_refcnt); /* drop hold for timer */ rc = 0; } return rc; } /** * fc_exch_ptr_get() - Return an exchange from an exchange pool * @pool: Exchange Pool to get an exchange from * @index: Index of the exchange within the pool * * Use the index to get an exchange from within an exchange pool. exches * will point to an array of exchange pointers. The index will select * the exchange within the array. */ static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool, u16 index) { struct fc_exch **exches = (struct fc_exch **)(pool + 1); return exches[index]; } /** * fc_exch_ptr_set() - Assign an exchange to a slot in an exchange pool * @pool: The pool to assign the exchange to * @index: The index in the pool where the exchange will be assigned * @ep: The exchange to assign to the pool */ static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index, struct fc_exch *ep) { ((struct fc_exch **)(pool + 1))[index] = ep; } /** * fc_exch_delete() - Delete an exchange * @ep: The exchange to be deleted */ static void fc_exch_delete(struct fc_exch *ep) { struct fc_exch_pool *pool; u16 index; pool = ep->pool; spin_lock_bh(&pool->lock); WARN_ON(pool->total_exches <= 0); pool->total_exches--; /* update cache of free slot */ index = (ep->xid - ep->em->min_xid) >> fc_cpu_order; if (pool->left == FC_XID_UNKNOWN) pool->left = index; else if (pool->right == FC_XID_UNKNOWN) pool->right = index; else pool->next_index = index; fc_exch_ptr_set(pool, index, NULL); list_del(&ep->ex_list); spin_unlock_bh(&pool->lock); fc_exch_release(ep); /* drop hold for exch in mp */ } /** * fc_exch_timer_set_locked() - Start a timer for an exchange w/ the * the exchange lock held * @ep: The exchange whose timer will start * @timer_msec: The timeout period * * Used for upper level protocols to time out the exchange. * The timer is cancelled when it fires or when the exchange completes. */ static inline void fc_exch_timer_set_locked(struct fc_exch *ep, unsigned int timer_msec) { if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) return; FC_EXCH_DBG(ep, "Exchange timer armed\n"); if (queue_delayed_work(fc_exch_workqueue, &ep->timeout_work, msecs_to_jiffies(timer_msec))) fc_exch_hold(ep); /* hold for timer */ } /** * fc_exch_timer_set() - Lock the exchange and set the timer * @ep: The exchange whose timer will start * @timer_msec: The timeout period */ static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec) { spin_lock_bh(&ep->ex_lock); fc_exch_timer_set_locked(ep, timer_msec); spin_unlock_bh(&ep->ex_lock); } /** * fc_seq_send() - Send a frame using existing sequence/exchange pair * @lport: The local port that the exchange will be sent on * @sp: The sequence to be sent * @fp: The frame to be sent on the exchange */ static int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp, struct fc_frame *fp) { struct fc_exch *ep; struct fc_frame_header *fh = fc_frame_header_get(fp); int error; u32 f_ctl; ep = fc_seq_exch(sp); WARN_ON((ep->esb_stat & ESB_ST_SEQ_INIT) != ESB_ST_SEQ_INIT); f_ctl = ntoh24(fh->fh_f_ctl); fc_exch_setup_hdr(ep, fp, f_ctl); fr_encaps(fp) = ep->encaps; /* * update sequence count if this frame is carrying * multiple FC frames when sequence offload is enabled * by LLD. */ if (fr_max_payload(fp)) sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)), fr_max_payload(fp)); else sp->cnt++; /* * Send the frame. */ error = lport->tt.frame_send(lport, fp); /* * Update the exchange and sequence flags, * assuming all frames for the sequence have been sent. * We can only be called to send once for each sequence. */ spin_lock_bh(&ep->ex_lock); ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */ if (f_ctl & FC_FC_SEQ_INIT) ep->esb_stat &= ~ESB_ST_SEQ_INIT; spin_unlock_bh(&ep->ex_lock); return error; } /** * fc_seq_alloc() - Allocate a sequence for a given exchange * @ep: The exchange to allocate a new sequence for * @seq_id: The sequence ID to be used * * We don't support multiple originated sequences on the same exchange. * By implication, any previously originated sequence on this exchange * is complete, and we reallocate the same sequence. */ static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id) { struct fc_seq *sp; sp = &ep->seq; sp->ssb_stat = 0; sp->cnt = 0; sp->id = seq_id; return sp; } /** * fc_seq_start_next_locked() - Allocate a new sequence on the same * exchange as the supplied sequence * @sp: The sequence/exchange to get a new sequence for */ static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp) { struct fc_exch *ep = fc_seq_exch(sp); sp = fc_seq_alloc(ep, ep->seq_id++); FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n", ep->f_ctl, sp->id); return sp; } /** * fc_seq_start_next() - Lock the exchange and get a new sequence * for a given sequence/exchange pair * @sp: The sequence/exchange to get a new exchange for */ static struct fc_seq *fc_seq_start_next(struct fc_seq *sp) { struct fc_exch *ep = fc_seq_exch(sp); spin_lock_bh(&ep->ex_lock); sp = fc_seq_start_next_locked(sp); spin_unlock_bh(&ep->ex_lock); return sp; } /* * Set the response handler for the exchange associated with a sequence. */ static void fc_seq_set_resp(struct fc_seq *sp, void (*resp)(struct fc_seq *, struct fc_frame *, void *), void *arg) { struct fc_exch *ep = fc_seq_exch(sp); spin_lock_bh(&ep->ex_lock); ep->resp = resp; ep->arg = arg; spin_unlock_bh(&ep->ex_lock); } /** * fc_seq_exch_abort() - Abort an exchange and sequence * @req_sp: The sequence to be aborted * @timer_msec: The period of time to wait before aborting * * Generally called because of a timeout or an abort from the upper layer. */ static int fc_seq_exch_abort(const struct fc_seq *req_sp, unsigned int timer_msec) { struct fc_seq *sp; struct fc_exch *ep; struct fc_frame *fp; int error; ep = fc_seq_exch(req_sp); spin_lock_bh(&ep->ex_lock); if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) || ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) { spin_unlock_bh(&ep->ex_lock); return -ENXIO; } /* * Send the abort on a new sequence if possible. */ sp = fc_seq_start_next_locked(&ep->seq); if (!sp) { spin_unlock_bh(&ep->ex_lock); return -ENOMEM; } ep->esb_stat |= ESB_ST_SEQ_INIT | ESB_ST_ABNORMAL; if (timer_msec) fc_exch_timer_set_locked(ep, timer_msec); spin_unlock_bh(&ep->ex_lock); /* * If not logged into the fabric, don't send ABTS but leave * sequence active until next timeout. */ if (!ep->sid) return 0; /* * Send an abort for the sequence that timed out. */ fp = fc_frame_alloc(ep->lp, 0); if (fp) { fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid, FC_TYPE_BLS, FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0); error = fc_seq_send(ep->lp, sp, fp); } else error = -ENOBUFS; return error; } /** * fc_exch_timeout() - Handle exchange timer expiration * @work: The work_struct identifying the exchange that timed out */ static void fc_exch_timeout(struct work_struct *work) { struct fc_exch *ep = container_of(work, struct fc_exch, timeout_work.work); struct fc_seq *sp = &ep->seq; void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg); void *arg; u32 e_stat; int rc = 1; FC_EXCH_DBG(ep, "Exchange timed out\n"); spin_lock_bh(&ep->ex_lock); if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) goto unlock; e_stat = ep->esb_stat; if (e_stat & ESB_ST_COMPLETE) { ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL; spin_unlock_bh(&ep->ex_lock); if (e_stat & ESB_ST_REC_QUAL) fc_exch_rrq(ep); goto done; } else { resp = ep->resp; arg = ep->arg; ep->resp = NULL; if (e_stat & ESB_ST_ABNORMAL) rc = fc_exch_done_locked(ep); spin_unlock_bh(&ep->ex_lock); if (resp) resp(sp, ERR_PTR(-FC_EX_TIMEOUT), arg); if (!rc) { /* delete the exchange if it's already being aborted */ fc_exch_delete(ep); return; } fc_seq_exch_abort(sp, 2 * ep->r_a_tov); goto done; } unlock: spin_unlock_bh(&ep->ex_lock); done: /* * This release matches the hold taken when the timer was set. */ fc_exch_release(ep); } /** * fc_exch_em_alloc() - Allocate an exchange from a specified EM. * @lport: The local port that the exchange is for * @mp: The exchange manager that will allocate the exchange * * Returns pointer to allocated fc_exch with exch lock held. */ static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport, struct fc_exch_mgr *mp) { struct fc_exch *ep; unsigned int cpu; u16 index; struct fc_exch_pool *pool; /* allocate memory for exchange */ ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC); if (!ep) { atomic_inc(&mp->stats.no_free_exch); goto out; } memset(ep, 0, sizeof(*ep)); cpu = get_cpu(); pool = per_cpu_ptr(mp->pool, cpu); spin_lock_bh(&pool->lock); put_cpu(); /* peek cache of free slot */ if (pool->left != FC_XID_UNKNOWN) { index = pool->left; pool->left = FC_XID_UNKNOWN; goto hit; } if (pool->right != FC_XID_UNKNOWN) { index = pool->right; pool->right = FC_XID_UNKNOWN; goto hit; } index = pool->next_index; /* allocate new exch from pool */ while (fc_exch_ptr_get(pool, index)) { index = index == mp->pool_max_index ? 0 : index + 1; if (index == pool->next_index) goto err; } pool->next_index = index == mp->pool_max_index ? 0 : index + 1; hit: fc_exch_hold(ep); /* hold for exch in mp */ spin_lock_init(&ep->ex_lock); /* * Hold exch lock for caller to prevent fc_exch_reset() * from releasing exch while fc_exch_alloc() caller is * still working on exch. */ spin_lock_bh(&ep->ex_lock); fc_exch_ptr_set(pool, index, ep); list_add_tail(&ep->ex_list, &pool->ex_list); fc_seq_alloc(ep, ep->seq_id++); pool->total_exches++; spin_unlock_bh(&pool->lock); /* * update exchange */ ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid; ep->em = mp; ep->pool = pool; ep->lp = lport; ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */ ep->rxid = FC_XID_UNKNOWN; ep->class = mp->class; INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout); out: return ep; err: spin_unlock_bh(&pool->lock); atomic_inc(&mp->stats.no_free_exch_xid); mempool_free(ep, mp->ep_pool); return NULL; } /** * fc_exch_alloc() - Allocate an exchange from an EM on a * local port's list of EMs. * @lport: The local port that will own the exchange * @fp: The FC frame that the exchange will be for * * This function walks the list of exchange manager(EM) * anchors to select an EM for a new exchange allocation. The * EM is selected when a NULL match function pointer is encountered * or when a call to a match function returns true. */ static inline struct fc_exch *fc_exch_alloc(struct fc_lport *lport, struct fc_frame *fp) { struct fc_exch_mgr_anchor *ema; list_for_each_entry(ema, &lport->ema_list, ema_list) if (!ema->match || ema->match(fp)) return fc_exch_em_alloc(lport, ema->mp); return NULL; } /** * fc_exch_find() - Lookup and hold an exchange * @mp: The exchange manager to lookup the exchange from * @xid: The XID of the exchange to look up */ static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid) { struct fc_exch_pool *pool; struct fc_exch *ep = NULL; if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) { pool = per_cpu_ptr(mp->pool, xid & fc_cpu_mask); spin_lock_bh(&pool->lock); ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order); if (ep) { fc_exch_hold(ep); WARN_ON(ep->xid != xid); } spin_unlock_bh(&pool->lock); } return ep; } /** * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and * the memory allocated for the related objects may be freed. * @sp: The sequence that has completed */ static void fc_exch_done(struct fc_seq *sp) { struct fc_exch *ep = fc_seq_exch(sp); int rc; spin_lock_bh(&ep->ex_lock); rc = fc_exch_done_locked(ep); spin_unlock_bh(&ep->ex_lock); if (!rc) fc_exch_delete(ep); } /** * fc_exch_resp() - Allocate a new exchange for a response frame * @lport: The local port that the exchange was for * @mp: The exchange manager to allocate the exchange from * @fp: The response frame * * Sets the responder ID in the frame header. */ static struct fc_exch *fc_exch_resp(struct fc_lport *lport, struct fc_exch_mgr *mp, struct fc_frame *fp) { struct fc_exch *ep; struct fc_frame_header *fh; ep = fc_exch_alloc(lport, fp); if (ep) { ep->class = fc_frame_class(fp); /* * Set EX_CTX indicating we're responding on this exchange. */ ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */ ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */ fh = fc_frame_header_get(fp); ep->sid = ntoh24(fh->fh_d_id); ep->did = ntoh24(fh->fh_s_id); ep->oid = ep->did; /* * Allocated exchange has placed the XID in the * originator field. Move it to the responder field, * and set the originator XID from the frame. */ ep->rxid = ep->xid; ep->oxid = ntohs(fh->fh_ox_id); ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT; if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0) ep->esb_stat &= ~ESB_ST_SEQ_INIT; fc_exch_hold(ep); /* hold for caller */ spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */ } return ep; } /** * fc_seq_lookup_recip() - Find a sequence where the other end * originated the sequence * @lport: The local port that the frame was sent to * @mp: The Exchange Manager to lookup the exchange from * @fp: The frame associated with the sequence we're looking for * * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold * on the ep that should be released by the caller. */ static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport, struct fc_exch_mgr *mp, struct fc_frame *fp) { struct fc_frame_header *fh = fc_frame_header_get(fp); struct fc_exch *ep = NULL; struct fc_seq *sp = NULL; enum fc_pf_rjt_reason reject = FC_RJT_NONE; u32 f_ctl; u16 xid; f_ctl = ntoh24(fh->fh_f_ctl); WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0); /* * Lookup or create the exchange if we will be creating the sequence. */ if (f_ctl & FC_FC_EX_CTX) { xid = ntohs(fh->fh_ox_id); /* we originated exch */ ep = fc_exch_find(mp, xid); if (!ep) { atomic_inc(&mp->stats.xid_not_found); reject = FC_RJT_OX_ID; goto out; } if (ep->rxid == FC_XID_UNKNOWN) ep->rxid = ntohs(fh->fh_rx_id); else if (ep->rxid != ntohs(fh->fh_rx_id)) { reject = FC_RJT_OX_ID; goto rel; } } else { xid = ntohs(fh->fh_rx_id); /* we are the responder */ /* * Special case for MDS issuing an ELS TEST with a * bad rxid of 0. * XXX take this out once we do the proper reject. */ if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ && fc_frame_payload_op(fp) == ELS_TEST) { fh->fh_rx_id = htons(FC_XID_UNKNOWN); xid = FC_XID_UNKNOWN; } /* * new sequence - find the exchange */ ep = fc_exch_find(mp, xid); if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) { if (ep) { atomic_inc(&mp->stats.xid_busy); reject = FC_RJT_RX_ID; goto rel; } ep = fc_exch_resp(lport, mp, fp); if (!ep) { reject = FC_RJT_EXCH_EST; /* XXX */ goto out; } xid = ep->xid; /* get our XID */ } else if (!ep) { atomic_inc(&mp->stats.xid_not_found); reject = FC_RJT_RX_ID; /* XID not found */ goto out; } } /* * At this point, we have the exchange held. * Find or create the sequence. */ if (fc_sof_is_init(fr_sof(fp))) { sp = &ep->seq; sp->ssb_stat |= SSB_ST_RESP; sp->id = fh->fh_seq_id; } else { sp = &ep->seq; if (sp->id != fh->fh_seq_id) { atomic_inc(&mp->stats.seq_not_found); reject = FC_RJT_SEQ_ID; /* sequence/exch should exist */ goto rel; } } WARN_ON(ep != fc_seq_exch(sp)); if (f_ctl & FC_FC_SEQ_INIT) ep->esb_stat |= ESB_ST_SEQ_INIT; fr_seq(fp) = sp; out: return reject; rel: fc_exch_done(&ep->seq); fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */ return reject; } /** * fc_seq_lookup_orig() - Find a sequence where this end * originated the sequence * @mp: The Exchange Manager to lookup the exchange from * @fp: The frame associated with the sequence we're looking for * * Does not hold the sequence for the caller. */ static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp, struct fc_frame *fp) { struct fc_frame_header *fh = fc_frame_header_get(fp); struct fc_exch *ep; struct fc_seq *sp = NULL; u32 f_ctl; u16 xid; f_ctl = ntoh24(fh->fh_f_ctl); WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX); xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id); ep = fc_exch_find(mp, xid); if (!ep) return NULL; if (ep->seq.id == fh->fh_seq_id) { /* * Save the RX_ID if we didn't previously know it. */ sp = &ep->seq; if ((f_ctl & FC_FC_EX_CTX) != 0 && ep->rxid == FC_XID_UNKNOWN) { ep->rxid = ntohs(fh->fh_rx_id); } } fc_exch_release(ep); return sp; } /** * fc_exch_set_addr() - Set the source and destination IDs for an exchange * @ep: The exchange to set the addresses for * @orig_id: The originator's ID * @resp_id: The responder's ID * * Note this must be done before the first sequence of the exchange is sent. */ static void fc_exch_set_addr(struct fc_exch *ep, u32 orig_id, u32 resp_id) { ep->oid = orig_id; if (ep->esb_stat & ESB_ST_RESP) { ep->sid = resp_id; ep->did = orig_id; } else { ep->sid = orig_id; ep->did = resp_id; } } /** * fc_seq_els_rsp_send() - Send an ELS response using infomation from * the existing sequence/exchange. * @fp: The received frame * @els_cmd: The ELS command to be sent * @els_data: The ELS data to be sent * * The received frame is not freed. */ static void fc_seq_els_rsp_send(struct fc_frame *fp, enum fc_els_cmd els_cmd, struct fc_seq_els_data *els_data) { switch (els_cmd) { case ELS_LS_RJT: fc_seq_ls_rjt(fp, els_data->reason, els_data->explan); break; case ELS_LS_ACC: fc_seq_ls_acc(fp); break; case ELS_RRQ: fc_exch_els_rrq(fp); break; case ELS_REC: fc_exch_els_rec(fp); break; default: FC_LPORT_DBG(fr_dev(fp), "Invalid ELS CMD:%x\n", els_cmd); } } /** * fc_seq_send_last() - Send a sequence that is the last in the exchange * @sp: The sequence that is to be sent * @fp: The frame that will be sent on the sequence * @rctl: The R_CTL information to be sent * @fh_type: The frame header type */ static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp, enum fc_rctl rctl, enum fc_fh_type fh_type) { u32 f_ctl; struct fc_exch *ep = fc_seq_exch(sp); f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT; f_ctl |= ep->f_ctl; fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0); fc_seq_send(ep->lp, sp, fp); } /** * fc_seq_send_ack() - Send an acknowledgement that we've received a frame * @sp: The sequence to send the ACK on * @rx_fp: The received frame that is being acknoledged * * Send ACK_1 (or equiv.) indicating we received something. */ static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp) { struct fc_frame *fp; struct fc_frame_header *rx_fh; struct fc_frame_header *fh; struct fc_exch *ep = fc_seq_exch(sp); struct fc_lport *lport = ep->lp; unsigned int f_ctl; /* * Don't send ACKs for class 3. */ if (fc_sof_needs_ack(fr_sof(rx_fp))) { fp = fc_frame_alloc(lport, 0); if (!fp) return; fh = fc_frame_header_get(fp); fh->fh_r_ctl = FC_RCTL_ACK_1; fh->fh_type = FC_TYPE_BLS; /* * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22). * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT. * Bits 9-8 are meaningful (retransmitted or unidirectional). * Last ACK uses bits 7-6 (continue sequence), * bits 5-4 are meaningful (what kind of ACK to use). */ rx_fh = fc_frame_header_get(rx_fp); f_ctl = ntoh24(rx_fh->fh_f_ctl); f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX | FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT | FC_FC_RETX_SEQ | FC_FC_UNI_TX; f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX; hton24(fh->fh_f_ctl, f_ctl); fc_exch_setup_hdr(ep, fp, f_ctl); fh->fh_seq_id = rx_fh->fh_seq_id; fh->fh_seq_cnt = rx_fh->fh_seq_cnt; fh->fh_parm_offset = htonl(1); /* ack single frame */ fr_sof(fp) = fr_sof(rx_fp); if (f_ctl & FC_FC_END_SEQ) fr_eof(fp) = FC_EOF_T; else fr_eof(fp) = FC_EOF_N; lport->tt.frame_send(lport, fp); } } /** * fc_exch_send_ba_rjt() - Send BLS Reject * @rx_fp: The frame being rejected * @reason: The reason the frame is being rejected * @explan: The explaination for the rejection * * This is for rejecting BA_ABTS only. */ static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp, enum fc_ba_rjt_reason reason, enum fc_ba_rjt_explan explan) { struct fc_frame *fp; struct fc_frame_header *rx_fh; struct fc_frame_header *fh; struct fc_ba_rjt *rp; struct fc_lport *lport; unsigned int f_ctl; lport = fr_dev(rx_fp); fp = fc_frame_alloc(lport, sizeof(*rp)); if (!fp) return; fh = fc_frame_header_get(fp); rx_fh = fc_frame_header_get(rx_fp); memset(fh, 0, sizeof(*fh) + sizeof(*rp)); rp = fc_frame_payload_get(fp, sizeof(*rp)); rp->br_reason = reason; rp->br_explan = explan; /* * seq_id, cs_ctl, df_ctl and param/offset are zero. */ memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3); memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3); fh->fh_ox_id = rx_fh->fh_ox_id; fh->fh_rx_id = rx_fh->fh_rx_id; fh->fh_seq_cnt = rx_fh->fh_seq_cnt; fh->fh_r_ctl = FC_RCTL_BA_RJT; fh->fh_type = FC_TYPE_BLS; /* * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22). * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT. * Bits 9-8 are meaningful (retransmitted or unidirectional). * Last ACK uses bits 7-6 (continue sequence), * bits 5-4 are meaningful (what kind of ACK to use). * Always set LAST_SEQ, END_SEQ. */ f_ctl = ntoh24(rx_fh->fh_f_ctl); f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX | FC_FC_END_CONN | FC_FC_SEQ_INIT | FC_FC_RETX_SEQ | FC_FC_UNI_TX; f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX; f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ; f_ctl &= ~FC_FC_FIRST_SEQ; hton24(fh->fh_f_ctl, f_ctl); fr_sof(fp) = fc_sof_class(fr_sof(rx_fp)); fr_eof(fp) = FC_EOF_T; if (fc_sof_needs_ack(fr_sof(fp))) fr_eof(fp) = FC_EOF_N; lport->tt.frame_send(lport, fp); } /** * fc_exch_recv_abts() - Handle an incoming ABTS * @ep: The exchange the abort was on * @rx_fp: The ABTS frame * * This would be for target mode usually, but could be due to lost * FCP transfer ready, confirm or RRQ. We always handle this as an * exchange abort, ignoring the parameter. */ static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp) { struct fc_frame *fp; struct fc_ba_acc *ap; struct fc_frame_header *fh; struct fc_seq *sp; if (!ep) goto reject; spin_lock_bh(&ep->ex_lock); if (ep->esb_stat & ESB_ST_COMPLETE) { spin_unlock_bh(&ep->ex_lock); goto reject; } if (!(ep->esb_stat & ESB_ST_REC_QUAL)) fc_exch_hold(ep); /* hold for REC_QUAL */ ep->esb_stat |= ESB_ST_ABNORMAL | ESB_ST_REC_QUAL; fc_exch_timer_set_locked(ep, ep->r_a_tov); fp = fc_frame_alloc(ep->lp, sizeof(*ap)); if (!fp) { spin_unlock_bh(&ep->ex_lock); goto free; } fh = fc_frame_header_get(fp); ap = fc_frame_payload_get(fp, sizeof(*ap)); memset(ap, 0, sizeof(*ap)); sp = &ep->seq; ap->ba_high_seq_cnt = htons(0xffff); if (sp->ssb_stat & SSB_ST_RESP) { ap->ba_seq_id = sp->id; ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL; ap->ba_high_seq_cnt = fh->fh_seq_cnt; ap->ba_low_seq_cnt = htons(sp->cnt); } sp = fc_seq_start_next_locked(sp); spin_unlock_bh(&ep->ex_lock); fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS); fc_frame_free(rx_fp); return; reject: fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID); free: fc_frame_free(rx_fp); } /** * fc_seq_assign() - Assign exchange and sequence for incoming request * @lport: The local port that received the request * @fp: The request frame * * On success, the sequence pointer will be returned and also in fr_seq(@fp). * A reference will be held on the exchange/sequence for the caller, which * must call fc_seq_release(). */ static struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp) { struct fc_exch_mgr_anchor *ema; WARN_ON(lport != fr_dev(fp)); WARN_ON(fr_seq(fp)); fr_seq(fp) = NULL; list_for_each_entry(ema, &lport->ema_list, ema_list) if ((!ema->match || ema->match(fp)) && fc_seq_lookup_recip(lport, ema->mp, fp) == FC_RJT_NONE) break; return fr_seq(fp); } /** * fc_seq_release() - Release the hold * @sp: The sequence. */ static void fc_seq_release(struct fc_seq *sp) { fc_exch_release(fc_seq_exch(sp)); } /** * fc_exch_recv_req() - Handler for an incoming request * @lport: The local port that received the request * @mp: The EM that the exchange is on * @fp: The request frame * * This is used when the other end is originating the exchange * and the sequence. */ static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp, struct fc_frame *fp) { struct fc_frame_header *fh = fc_frame_header_get(fp); struct fc_seq *sp = NULL; struct fc_exch *ep = NULL; enum fc_pf_rjt_reason reject; /* We can have the wrong fc_lport at this point with NPIV, which is a * problem now that we know a new exchange needs to be allocated */ lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id)); if (!lport) { fc_frame_free(fp); return; } fr_dev(fp) = lport; BUG_ON(fr_seq(fp)); /* XXX remove later */ /* * If the RX_ID is 0xffff, don't allocate an exchange. * The upper-level protocol may request one later, if needed. */ if (fh->fh_rx_id == htons(FC_XID_UNKNOWN)) return lport->tt.lport_recv(lport, fp); reject = fc_seq_lookup_recip(lport, mp, fp); if (reject == FC_RJT_NONE) { sp = fr_seq(fp); /* sequence will be held */ ep = fc_seq_exch(sp); fc_seq_send_ack(sp, fp); ep->encaps = fr_encaps(fp); /* * Call the receive function. * * The receive function may allocate a new sequence * over the old one, so we shouldn't change the * sequence after this. * * The frame will be freed by the receive function. * If new exch resp handler is valid then call that * first. */ if (ep->resp) ep->resp(sp, fp, ep->arg); else lport->tt.lport_recv(lport, fp); fc_exch_release(ep); /* release from lookup */ } else { FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n", reject); fc_frame_free(fp); } } /** * fc_exch_recv_seq_resp() - Handler for an incoming response where the other * end is the originator of the sequence that is a * response to our initial exchange * @mp: The EM that the exchange is on * @fp: The response frame */ static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp) { struct fc_frame_header *fh = fc_frame_header_get(fp); struct fc_seq *sp; struct fc_exch *ep; enum fc_sof sof; u32 f_ctl; void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg); void *ex_resp_arg; int rc; ep = fc_exch_find(mp, ntohs(fh->fh_ox_id)); if (!ep) { atomic_inc(&mp->stats.xid_not_found); goto out; } if (ep->esb_stat & ESB_ST_COMPLETE) { atomic_inc(&mp->stats.xid_not_found); goto rel; } if (ep->rxid == FC_XID_UNKNOWN) ep->rxid = ntohs(fh->fh_rx_id); if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) { atomic_inc(&mp->stats.xid_not_found); goto rel; } if (ep->did != ntoh24(fh->fh_s_id) && ep->did != FC_FID_FLOGI) { atomic_inc(&mp->stats.xid_not_found); goto rel; } sof = fr_sof(fp); sp = &ep->seq; if (fc_sof_is_init(sof)) { sp->ssb_stat |= SSB_ST_RESP; sp->id = fh->fh_seq_id; } else if (sp->id != fh->fh_seq_id) { atomic_inc(&mp->stats.seq_not_found); goto rel; } f_ctl = ntoh24(fh->fh_f_ctl); fr_seq(fp) = sp; if (f_ctl & FC_FC_SEQ_INIT) ep->esb_stat |= ESB_ST_SEQ_INIT; if (fc_sof_needs_ack(sof)) fc_seq_send_ack(sp, fp); resp = ep->resp; ex_resp_arg = ep->arg; if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T && (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) == (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) { spin_lock_bh(&ep->ex_lock); rc = fc_exch_done_locked(ep); WARN_ON(fc_seq_exch(sp) != ep); spin_unlock_bh(&ep->ex_lock); if (!rc) fc_exch_delete(ep); } /* * Call the receive function. * The sequence is held (has a refcnt) for us, * but not for the receive function. * * The receive function may allocate a new sequence * over the old one, so we shouldn't change the * sequence after this. * * The frame will be freed by the receive function. * If new exch resp handler is valid then call that * first. */ if (resp) resp(sp, fp, ex_resp_arg); else fc_frame_free(fp); fc_exch_release(ep); return; rel: fc_exch_release(ep); out: fc_frame_free(fp); } /** * fc_exch_recv_resp() - Handler for a sequence where other end is * responding to our sequence * @mp: The EM that the exchange is on * @fp: The response frame */ static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp) { struct fc_seq *sp; sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */ if (!sp) atomic_inc(&mp->stats.xid_not_found); else atomic_inc(&mp->stats.non_bls_resp); fc_frame_free(fp); } /** * fc_exch_abts_resp() - Handler for a response to an ABT * @ep: The exchange that the frame is on * @fp: The response frame * * This response would be to an ABTS cancelling an exchange or sequence. * The response can be either BA_ACC or BA_RJT */ static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp) { void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg); void *ex_resp_arg; struct fc_frame_header *fh; struct fc_ba_acc *ap; struct fc_seq *sp; u16 low; u16 high; int rc = 1, has_rec = 0; fh = fc_frame_header_get(fp); FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl, fc_exch_rctl_name(fh->fh_r_ctl)); if (cancel_delayed_work_sync(&ep->timeout_work)) fc_exch_release(ep); /* release from pending timer hold */ spin_lock_bh(&ep->ex_lock); switch (fh->fh_r_ctl) { case FC_RCTL_BA_ACC: ap = fc_frame_payload_get(fp, sizeof(*ap)); if (!ap) break; /* * Decide whether to establish a Recovery Qualifier. * We do this if there is a non-empty SEQ_CNT range and * SEQ_ID is the same as the one we aborted. */ low = ntohs(ap->ba_low_seq_cnt); high = ntohs(ap->ba_high_seq_cnt); if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 && (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL || ap->ba_seq_id == ep->seq_id) && low != high) { ep->esb_stat |= ESB_ST_REC_QUAL; fc_exch_hold(ep); /* hold for recovery qualifier */ has_rec = 1; } break; case FC_RCTL_BA_RJT: break; default: break; } resp = ep->resp; ex_resp_arg = ep->arg; /* do we need to do some other checks here. Can we reuse more of * fc_exch_recv_seq_resp */ sp = &ep->seq; /* * do we want to check END_SEQ as well as LAST_SEQ here? */ if (ep->fh_type != FC_TYPE_FCP && ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ) rc = fc_exch_done_locked(ep); spin_unlock_bh(&ep->ex_lock); if (!rc) fc_exch_delete(ep); if (resp) resp(sp, fp, ex_resp_arg); else fc_frame_free(fp); if (has_rec) fc_exch_timer_set(ep, ep->r_a_tov); } /** * fc_exch_recv_bls() - Handler for a BLS sequence * @mp: The EM that the exchange is on * @fp: The request frame * * The BLS frame is always a sequence initiated by the remote side. * We may be either the originator or recipient of the exchange. */ static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp) { struct fc_frame_header *fh; struct fc_exch *ep; u32 f_ctl; fh = fc_frame_header_get(fp); f_ctl = ntoh24(fh->fh_f_ctl); fr_seq(fp) = NULL; ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ? ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id)); if (ep && (f_ctl & FC_FC_SEQ_INIT)) { spin_lock_bh(&ep->ex_lock); ep->esb_stat |= ESB_ST_SEQ_INIT; spin_unlock_bh(&ep->ex_lock); } if (f_ctl & FC_FC_SEQ_CTX) { /* * A response to a sequence we initiated. * This should only be ACKs for class 2 or F. */ switch (fh->fh_r_ctl) { case FC_RCTL_ACK_1: case FC_RCTL_ACK_0: break; default: FC_EXCH_DBG(ep, "BLS rctl %x - %s received", fh->fh_r_ctl, fc_exch_rctl_name(fh->fh_r_ctl)); break; } fc_frame_free(fp); } else { switch (fh->fh_r_ctl) { case FC_RCTL_BA_RJT: case FC_RCTL_BA_ACC: if (ep) fc_exch_abts_resp(ep, fp); else fc_frame_free(fp); break; case FC_RCTL_BA_ABTS: fc_exch_recv_abts(ep, fp); break; default: /* ignore junk */ fc_frame_free(fp); break; } } if (ep) fc_exch_release(ep); /* release hold taken by fc_exch_find */ } /** * fc_seq_ls_acc() - Accept sequence with LS_ACC * @rx_fp: The received frame, not freed here. * * If this fails due to allocation or transmit congestion, assume the * originator will repeat the sequence. */ static void fc_seq_ls_acc(struct fc_frame *rx_fp) { struct fc_lport *lport; struct fc_els_ls_acc *acc; struct fc_frame *fp; lport = fr_dev(rx_fp); fp = fc_frame_alloc(lport, sizeof(*acc)); if (!fp) return; acc = fc_frame_payload_get(fp, sizeof(*acc)); memset(acc, 0, sizeof(*acc)); acc->la_cmd = ELS_LS_ACC; fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0); lport->tt.frame_send(lport, fp); } /** * fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT * @rx_fp: The received frame, not freed here. * @reason: The reason the sequence is being rejected * @explan: The explanation for the rejection * * If this fails due to allocation or transmit congestion, assume the * originator will repeat the sequence. */ static void fc_seq_ls_rjt(struct fc_frame *rx_fp, enum fc_els_rjt_reason reason, enum fc_els_rjt_explan explan) { struct fc_lport *lport; struct fc_els_ls_rjt *rjt; struct fc_frame *fp; lport = fr_dev(rx_fp); fp = fc_frame_alloc(lport, sizeof(*rjt)); if (!fp) return; rjt = fc_frame_payload_get(fp, sizeof(*rjt)); memset(rjt, 0, sizeof(*rjt)); rjt->er_cmd = ELS_LS_RJT; rjt->er_reason = reason; rjt->er_explan = explan; fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0); lport->tt.frame_send(lport, fp); } /** * fc_exch_reset() - Reset an exchange * @ep: The exchange to be reset */ static void fc_exch_reset(struct fc_exch *ep) { struct fc_seq *sp; void (*resp)(struct fc_seq *, struct fc_frame *, void *); void *arg; int rc = 1; spin_lock_bh(&ep->ex_lock); ep->state |= FC_EX_RST_CLEANUP; if (cancel_delayed_work(&ep->timeout_work)) atomic_dec(&ep->ex_refcnt); /* drop hold for timer */ resp = ep->resp; ep->resp = NULL; if (ep->esb_stat & ESB_ST_REC_QUAL) atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */ ep->esb_stat &= ~ESB_ST_REC_QUAL; arg = ep->arg; sp = &ep->seq; rc = fc_exch_done_locked(ep); spin_unlock_bh(&ep->ex_lock); if (!rc) fc_exch_delete(ep); if (resp) resp(sp, ERR_PTR(-FC_EX_CLOSED), arg); } /** * fc_exch_pool_reset() - Reset a per cpu exchange pool * @lport: The local port that the exchange pool is on * @pool: The exchange pool to be reset * @sid: The source ID * @did: The destination ID * * Resets a per cpu exches pool, releasing all of its sequences * and exchanges. If sid is non-zero then reset only exchanges * we sourced from the local port's FID. If did is non-zero then * only reset exchanges destined for the local port's FID. */ static void fc_exch_pool_reset(struct fc_lport *lport, struct fc_exch_pool *pool, u32 sid, u32 did) { struct fc_exch *ep; struct fc_exch *next; spin_lock_bh(&pool->lock); restart: list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) { if ((lport == ep->lp) && (sid == 0 || sid == ep->sid) && (did == 0 || did == ep->did)) { fc_exch_hold(ep); spin_unlock_bh(&pool->lock); fc_exch_reset(ep); fc_exch_release(ep); spin_lock_bh(&pool->lock); /* * must restart loop incase while lock * was down multiple eps were released. */ goto restart; } } spin_unlock_bh(&pool->lock); } /** * fc_exch_mgr_reset() - Reset all EMs of a local port * @lport: The local port whose EMs are to be reset * @sid: The source ID * @did: The destination ID * * Reset all EMs associated with a given local port. Release all * sequences and exchanges. If sid is non-zero then reset only the * exchanges sent from the local port's FID. If did is non-zero then * reset only exchanges destined for the local port's FID. */ void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did) { struct fc_exch_mgr_anchor *ema; unsigned int cpu; list_for_each_entry(ema, &lport->ema_list, ema_list) { for_each_possible_cpu(cpu) fc_exch_pool_reset(lport, per_cpu_ptr(ema->mp->pool, cpu), sid, did); } } EXPORT_SYMBOL(fc_exch_mgr_reset); /** * fc_exch_lookup() - find an exchange * @lport: The local port * @xid: The exchange ID * * Returns exchange pointer with hold for caller, or NULL if not found. */ static struct fc_exch *fc_exch_lookup(struct fc_lport *lport, u32 xid) { struct fc_exch_mgr_anchor *ema; list_for_each_entry(ema, &lport->ema_list, ema_list) if (ema->mp->min_xid <= xid && xid <= ema->mp->max_xid) return fc_exch_find(ema->mp, xid); return NULL; } /** * fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests * @rfp: The REC frame, not freed here. * * Note that the requesting port may be different than the S_ID in the request. */ static void fc_exch_els_rec(struct fc_frame *rfp) { struct fc_lport *lport; struct fc_frame *fp; struct fc_exch *ep; struct fc_els_rec *rp; struct fc_els_rec_acc *acc; enum fc_els_rjt_reason reason = ELS_RJT_LOGIC; enum fc_els_rjt_explan explan; u32 sid; u16 rxid; u16 oxid; lport = fr_dev(rfp); rp = fc_frame_payload_get(rfp, sizeof(*rp)); explan = ELS_EXPL_INV_LEN; if (!rp) goto reject; sid = ntoh24(rp->rec_s_id); rxid = ntohs(rp->rec_rx_id); oxid = ntohs(rp->rec_ox_id); ep = fc_exch_lookup(lport, sid == fc_host_port_id(lport->host) ? oxid : rxid); explan = ELS_EXPL_OXID_RXID; if (!ep) goto reject; if (ep->oid != sid || oxid != ep->oxid) goto rel; if (rxid != FC_XID_UNKNOWN && rxid != ep->rxid) goto rel; fp = fc_frame_alloc(lport, sizeof(*acc)); if (!fp) goto out; acc = fc_frame_payload_get(fp, sizeof(*acc)); memset(acc, 0, sizeof(*acc)); acc->reca_cmd = ELS_LS_ACC; acc->reca_ox_id = rp->rec_ox_id; memcpy(acc->reca_ofid, rp->rec_s_id, 3); acc->reca_rx_id = htons(ep->rxid); if (ep->sid == ep->oid) hton24(acc->reca_rfid, ep->did); else hton24(acc->reca_rfid, ep->sid); acc->reca_fc4value = htonl(ep->seq.rec_data); acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP | ESB_ST_SEQ_INIT | ESB_ST_COMPLETE)); fc_fill_reply_hdr(fp, rfp, FC_RCTL_ELS_REP, 0); lport->tt.frame_send(lport, fp); out: fc_exch_release(ep); return; rel: fc_exch_release(ep); reject: fc_seq_ls_rjt(rfp, reason, explan); } /** * fc_exch_rrq_resp() - Handler for RRQ responses * @sp: The sequence that the RRQ is on * @fp: The RRQ frame * @arg: The exchange that the RRQ is on * * TODO: fix error handler. */ static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg) { struct fc_exch *aborted_ep = arg; unsigned int op; if (IS_ERR(fp)) { int err = PTR_ERR(fp); if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT) goto cleanup; FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, " "frame error %d\n", err); return; } op = fc_frame_payload_op(fp); fc_frame_free(fp); switch (op) { case ELS_LS_RJT: FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ"); /* fall through */ case ELS_LS_ACC: goto cleanup; default: FC_EXCH_DBG(aborted_ep, "unexpected response op %x " "for RRQ", op); return; } cleanup: fc_exch_done(&aborted_ep->seq); /* drop hold for rec qual */ fc_exch_release(aborted_ep); } /** * fc_exch_seq_send() - Send a frame using a new exchange and sequence * @lport: The local port to send the frame on * @fp: The frame to be sent * @resp: The response handler for this request * @destructor: The destructor for the exchange * @arg: The argument to be passed to the response handler * @timer_msec: The timeout period for the exchange * * The frame pointer with some of the header's fields must be * filled before calling this routine, those fields are: * * - routing control * - FC port did * - FC port sid * - FC header type * - frame control * - parameter or relative offset */ static struct fc_seq *fc_exch_seq_send(struct fc_lport *lport, struct fc_frame *fp, void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg), void (*destructor)(struct fc_seq *, void *), void *arg, u32 timer_msec) { struct fc_exch *ep; struct fc_seq *sp = NULL; struct fc_frame_header *fh; int rc = 1; ep = fc_exch_alloc(lport, fp); if (!ep) { fc_frame_free(fp); return NULL; } ep->esb_stat |= ESB_ST_SEQ_INIT; fh = fc_frame_header_get(fp); fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id)); ep->resp = resp; ep->destructor = destructor; ep->arg = arg; ep->r_a_tov = FC_DEF_R_A_TOV; ep->lp = lport; sp = &ep->seq; ep->fh_type = fh->fh_type; /* save for possbile timeout handling */ ep->f_ctl = ntoh24(fh->fh_f_ctl); fc_exch_setup_hdr(ep, fp, ep->f_ctl); sp->cnt++; if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD) fc_fcp_ddp_setup(fr_fsp(fp), ep->xid); if (unlikely(lport->tt.frame_send(lport, fp))) goto err; if (timer_msec) fc_exch_timer_set_locked(ep, timer_msec); ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */ if (ep->f_ctl & FC_FC_SEQ_INIT) ep->esb_stat &= ~ESB_ST_SEQ_INIT; spin_unlock_bh(&ep->ex_lock); return sp; err: rc = fc_exch_done_locked(ep); spin_unlock_bh(&ep->ex_lock); if (!rc) fc_exch_delete(ep); return NULL; } /** * fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command * @ep: The exchange to send the RRQ on * * This tells the remote port to stop blocking the use of * the exchange and the seq_cnt range. */ static void fc_exch_rrq(struct fc_exch *ep) { struct fc_lport *lport; struct fc_els_rrq *rrq; struct fc_frame *fp; u32 did; lport = ep->lp; fp = fc_frame_alloc(lport, sizeof(*rrq)); if (!fp) goto retry; rrq = fc_frame_payload_get(fp, sizeof(*rrq)); memset(rrq, 0, sizeof(*rrq)); rrq->rrq_cmd = ELS_RRQ; hton24(rrq->rrq_s_id, ep->sid); rrq->rrq_ox_id = htons(ep->oxid); rrq->rrq_rx_id = htons(ep->rxid); did = ep->did; if (ep->esb_stat & ESB_ST_RESP) did = ep->sid; fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did, lport->port_id, FC_TYPE_ELS, FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0); if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep, lport->e_d_tov)) return; retry: spin_lock_bh(&ep->ex_lock); if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) { spin_unlock_bh(&ep->ex_lock); /* drop hold for rec qual */ fc_exch_release(ep); return; } ep->esb_stat |= ESB_ST_REC_QUAL; fc_exch_timer_set_locked(ep, ep->r_a_tov); spin_unlock_bh(&ep->ex_lock); } /** * fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests * @fp: The RRQ frame, not freed here. */ static void fc_exch_els_rrq(struct fc_frame *fp) { struct fc_lport *lport; struct fc_exch *ep = NULL; /* request or subject exchange */ struct fc_els_rrq *rp; u32 sid; u16 xid; enum fc_els_rjt_explan explan; lport = fr_dev(fp); rp = fc_frame_payload_get(fp, sizeof(*rp)); explan = ELS_EXPL_INV_LEN; if (!rp) goto reject; /* * lookup subject exchange. */ sid = ntoh24(rp->rrq_s_id); /* subject source */ xid = fc_host_port_id(lport->host) == sid ? ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id); ep = fc_exch_lookup(lport, xid); explan = ELS_EXPL_OXID_RXID; if (!ep) goto reject; spin_lock_bh(&ep->ex_lock); if (ep->oxid != ntohs(rp->rrq_ox_id)) goto unlock_reject; if (ep->rxid != ntohs(rp->rrq_rx_id) && ep->rxid != FC_XID_UNKNOWN) goto unlock_reject; explan = ELS_EXPL_SID; if (ep->sid != sid) goto unlock_reject; /* * Clear Recovery Qualifier state, and cancel timer if complete. */ if (ep->esb_stat & ESB_ST_REC_QUAL) { ep->esb_stat &= ~ESB_ST_REC_QUAL; atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */ } if (ep->esb_stat & ESB_ST_COMPLETE) { if (cancel_delayed_work(&ep->timeout_work)) atomic_dec(&ep->ex_refcnt); /* drop timer hold */ } spin_unlock_bh(&ep->ex_lock); /* * Send LS_ACC. */ fc_seq_ls_acc(fp); goto out; unlock_reject: spin_unlock_bh(&ep->ex_lock); reject: fc_seq_ls_rjt(fp, ELS_RJT_LOGIC, explan); out: if (ep) fc_exch_release(ep); /* drop hold from fc_exch_find */ } /** * fc_exch_mgr_add() - Add an exchange manager to a local port's list of EMs * @lport: The local port to add the exchange manager to * @mp: The exchange manager to be added to the local port * @match: The match routine that indicates when this EM should be used */ struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport, struct fc_exch_mgr *mp, bool (*match)(struct fc_frame *)) { struct fc_exch_mgr_anchor *ema; ema = kmalloc(sizeof(*ema), GFP_ATOMIC); if (!ema) return ema; ema->mp = mp; ema->match = match; /* add EM anchor to EM anchors list */ list_add_tail(&ema->ema_list, &lport->ema_list); kref_get(&mp->kref); return ema; } EXPORT_SYMBOL(fc_exch_mgr_add); /** * fc_exch_mgr_destroy() - Destroy an exchange manager * @kref: The reference to the EM to be destroyed */ static void fc_exch_mgr_destroy(struct kref *kref) { struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref); mempool_destroy(mp->ep_pool); free_percpu(mp->pool); kfree(mp); } /** * fc_exch_mgr_del() - Delete an EM from a local port's list * @ema: The exchange manager anchor identifying the EM to be deleted */ void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema) { /* remove EM anchor from EM anchors list */ list_del(&ema->ema_list); kref_put(&ema->mp->kref, fc_exch_mgr_destroy); kfree(ema); } EXPORT_SYMBOL(fc_exch_mgr_del); /** * fc_exch_mgr_list_clone() - Share all exchange manager objects * @src: Source lport to clone exchange managers from * @dst: New lport that takes references to all the exchange managers */ int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst) { struct fc_exch_mgr_anchor *ema, *tmp; list_for_each_entry(ema, &src->ema_list, ema_list) { if (!fc_exch_mgr_add(dst, ema->mp, ema->match)) goto err; } return 0; err: list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list) fc_exch_mgr_del(ema); return -ENOMEM; } /** * fc_exch_mgr_alloc() - Allocate an exchange manager * @lport: The local port that the new EM will be associated with * @class: The default FC class for new exchanges * @min_xid: The minimum XID for exchanges from the new EM * @max_xid: The maximum XID for exchanges from the new EM * @match: The match routine for the new EM */ struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport, enum fc_class class, u16 min_xid, u16 max_xid, bool (*match)(struct fc_frame *)) { struct fc_exch_mgr *mp; u16 pool_exch_range; size_t pool_size; unsigned int cpu; struct fc_exch_pool *pool; if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN || (min_xid & fc_cpu_mask) != 0) { FC_LPORT_DBG(lport, "Invalid min_xid 0x:%x and max_xid 0x:%x\n", min_xid, max_xid); return NULL; } /* * allocate memory for EM */ mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC); if (!mp) return NULL; mp->class = class; /* adjust em exch xid range for offload */ mp->min_xid = min_xid; mp->max_xid = max_xid; mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep); if (!mp->ep_pool) goto free_mp; /* * Setup per cpu exch pool with entire exchange id range equally * divided across all cpus. The exch pointers array memory is * allocated for exch range per pool. */ pool_exch_range = (mp->max_xid - mp->min_xid + 1) / (fc_cpu_mask + 1); mp->pool_max_index = pool_exch_range - 1; /* * Allocate and initialize per cpu exch pool */ pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *); mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool)); if (!mp->pool) goto free_mempool; for_each_possible_cpu(cpu) { pool = per_cpu_ptr(mp->pool, cpu); pool->left = FC_XID_UNKNOWN; pool->right = FC_XID_UNKNOWN; spin_lock_init(&pool->lock); INIT_LIST_HEAD(&pool->ex_list); } kref_init(&mp->kref); if (!fc_exch_mgr_add(lport, mp, match)) { free_percpu(mp->pool); goto free_mempool; } /* * Above kref_init() sets mp->kref to 1 and then * call to fc_exch_mgr_add incremented mp->kref again, * so adjust that extra increment. */ kref_put(&mp->kref, fc_exch_mgr_destroy); return mp; free_mempool: mempool_destroy(mp->ep_pool); free_mp: kfree(mp); return NULL; } EXPORT_SYMBOL(fc_exch_mgr_alloc); /** * fc_exch_mgr_free() - Free all exchange managers on a local port * @lport: The local port whose EMs are to be freed */ void fc_exch_mgr_free(struct fc_lport *lport) { struct fc_exch_mgr_anchor *ema, *next; flush_workqueue(fc_exch_workqueue); list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list) fc_exch_mgr_del(ema); } EXPORT_SYMBOL(fc_exch_mgr_free); /** * fc_exch_recv() - Handler for received frames * @lport: The local port the frame was received on * @fp: The received frame */ void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp) { struct fc_frame_header *fh = fc_frame_header_get(fp); struct fc_exch_mgr_anchor *ema; u32 f_ctl, found = 0; u16 oxid; /* lport lock ? */ if (!lport || lport->state == LPORT_ST_DISABLED) { FC_LPORT_DBG(lport, "Receiving frames for an lport that " "has not been initialized correctly\n"); fc_frame_free(fp); return; } f_ctl = ntoh24(fh->fh_f_ctl); oxid = ntohs(fh->fh_ox_id); if (f_ctl & FC_FC_EX_CTX) { list_for_each_entry(ema, &lport->ema_list, ema_list) { if ((oxid >= ema->mp->min_xid) && (oxid <= ema->mp->max_xid)) { found = 1; break; } } if (!found) { FC_LPORT_DBG(lport, "Received response for out " "of range oxid:%hx\n", oxid); fc_frame_free(fp); return; } } else ema = list_entry(lport->ema_list.prev, typeof(*ema), ema_list); /* * If frame is marked invalid, just drop it. */ switch (fr_eof(fp)) { case FC_EOF_T: if (f_ctl & FC_FC_END_SEQ) skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl)); /* fall through */ case FC_EOF_N: if (fh->fh_type == FC_TYPE_BLS) fc_exch_recv_bls(ema->mp, fp); else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) == FC_FC_EX_CTX) fc_exch_recv_seq_resp(ema->mp, fp); else if (f_ctl & FC_FC_SEQ_CTX) fc_exch_recv_resp(ema->mp, fp); else /* no EX_CTX and no SEQ_CTX */ fc_exch_recv_req(lport, ema->mp, fp); break; default: FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)", fr_eof(fp)); fc_frame_free(fp); } } EXPORT_SYMBOL(fc_exch_recv); /** * fc_exch_init() - Initialize the exchange layer for a local port * @lport: The local port to initialize the exchange layer for */ int fc_exch_init(struct fc_lport *lport) { if (!lport->tt.seq_start_next) lport->tt.seq_start_next = fc_seq_start_next; if (!lport->tt.seq_set_resp) lport->tt.seq_set_resp = fc_seq_set_resp; if (!lport->tt.exch_seq_send) lport->tt.exch_seq_send = fc_exch_seq_send; if (!lport->tt.seq_send) lport->tt.seq_send = fc_seq_send; if (!lport->tt.seq_els_rsp_send) lport->tt.seq_els_rsp_send = fc_seq_els_rsp_send; if (!lport->tt.exch_done) lport->tt.exch_done = fc_exch_done; if (!lport->tt.exch_mgr_reset) lport->tt.exch_mgr_reset = fc_exch_mgr_reset; if (!lport->tt.seq_exch_abort) lport->tt.seq_exch_abort = fc_seq_exch_abort; if (!lport->tt.seq_assign) lport->tt.seq_assign = fc_seq_assign; if (!lport->tt.seq_release) lport->tt.seq_release = fc_seq_release; return 0; } EXPORT_SYMBOL(fc_exch_init); /** * fc_setup_exch_mgr() - Setup an exchange manager */ int fc_setup_exch_mgr(void) { fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch), 0, SLAB_HWCACHE_ALIGN, NULL); if (!fc_em_cachep) return -ENOMEM; /* * Initialize fc_cpu_mask and fc_cpu_order. The * fc_cpu_mask is set for nr_cpu_ids rounded up * to order of 2's * power and order is stored * in fc_cpu_order as this is later required in * mapping between an exch id and exch array index * in per cpu exch pool. * * This round up is required to align fc_cpu_mask * to exchange id's lower bits such that all incoming * frames of an exchange gets delivered to the same * cpu on which exchange originated by simple bitwise * AND operation between fc_cpu_mask and exchange id. */ fc_cpu_mask = 1; fc_cpu_order = 0; while (fc_cpu_mask < nr_cpu_ids) { fc_cpu_mask <<= 1; fc_cpu_order++; } fc_cpu_mask--; fc_exch_workqueue = create_singlethread_workqueue("fc_exch_workqueue"); if (!fc_exch_workqueue) return -ENOMEM; return 0; } /** * fc_destroy_exch_mgr() - Destroy an exchange manager */ void fc_destroy_exch_mgr(void) { destroy_workqueue(fc_exch_workqueue); kmem_cache_destroy(fc_em_cachep); }