v4.19.13 snapshot.
diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
new file mode 100644
index 0000000..42bcf7f
--- /dev/null
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -0,0 +1,2708 @@
+/*
+ * 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 <linux/export.h>
+#include <linux/log2.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 {
+ spinlock_t lock;
+ struct list_head ex_list;
+ u16 next_index;
+ u16 total_exches;
+
+ /* two cache of free slot in exch array */
+ u16 left;
+ u16 right;
+} ____cacheline_aligned_in_smp;
+
+/**
+ * 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 {
+ struct fc_exch_pool __percpu *pool;
+ mempool_t *ep_pool;
+ struct fc_lport *lport;
+ enum fc_class class;
+ struct kref kref;
+ u16 min_xid;
+ u16 max_xid;
+ u16 pool_max_index;
+
+ 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 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 remaining 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_timer_cancel() - cancel exch timer
+ * @ep: The exchange whose timer to be canceled
+ */
+static inline void fc_exch_timer_cancel(struct fc_exch *ep)
+{
+ if (cancel_delayed_work(&ep->timeout_work)) {
+ FC_EXCH_DBG(ep, "Exchange timer canceled\n");
+ atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
+ }
+}
+
+/**
+ * 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 : %d msecs\n", timer_msec);
+
+ fc_exch_hold(ep); /* hold for timer */
+ if (!queue_delayed_work(fc_exch_workqueue, &ep->timeout_work,
+ msecs_to_jiffies(timer_msec))) {
+ FC_EXCH_DBG(ep, "Exchange already queued\n");
+ fc_exch_release(ep);
+ }
+}
+
+/**
+ * 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_exch_done_locked() - Complete an exchange with the exchange lock held
+ * @ep: The exchange that is complete
+ *
+ * Note: May sleep if invoked from outside a response handler.
+ */
+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.
+ */
+ 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;
+ fc_exch_timer_cancel(ep);
+ rc = 0;
+ }
+ return rc;
+}
+
+static struct fc_exch fc_quarantine_exch;
+
+/**
+ * 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 (!(ep->state & FC_EX_QUARANTINE)) {
+ 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);
+ } else {
+ fc_exch_ptr_set(pool, index, &fc_quarantine_exch);
+ }
+ list_del(&ep->ex_list);
+ spin_unlock_bh(&pool->lock);
+ fc_exch_release(ep); /* drop hold for exch in mp */
+}
+
+static int fc_seq_send_locked(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 = -ENXIO;
+ u32 f_ctl;
+ u8 fh_type = fh->fh_type;
+
+ ep = fc_seq_exch(sp);
+
+ if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL)) {
+ fc_frame_free(fp);
+ goto out;
+ }
+
+ WARN_ON(!(ep->esb_stat & 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);
+
+ if (fh_type == FC_TYPE_BLS)
+ goto out;
+
+ /*
+ * 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.
+ */
+ 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;
+out:
+ return error;
+}
+
+/**
+ * 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
+ *
+ * Note: The frame will be freed either by a direct call to fc_frame_free(fp)
+ * or indirectly by calling libfc_function_template.frame_send().
+ */
+int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp, struct fc_frame *fp)
+{
+ struct fc_exch *ep;
+ int error;
+ ep = fc_seq_exch(sp);
+ spin_lock_bh(&ep->ex_lock);
+ error = fc_seq_send_locked(lport, sp, fp);
+ spin_unlock_bh(&ep->ex_lock);
+ return error;
+}
+EXPORT_SYMBOL(fc_seq_send);
+
+/**
+ * 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
+ */
+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;
+}
+EXPORT_SYMBOL(fc_seq_start_next);
+
+/*
+ * Set the response handler for the exchange associated with a sequence.
+ *
+ * Note: May sleep if invoked from outside a response handler.
+ */
+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);
+ DEFINE_WAIT(wait);
+
+ spin_lock_bh(&ep->ex_lock);
+ while (ep->resp_active && ep->resp_task != current) {
+ prepare_to_wait(&ep->resp_wq, &wait, TASK_UNINTERRUPTIBLE);
+ spin_unlock_bh(&ep->ex_lock);
+
+ schedule();
+
+ spin_lock_bh(&ep->ex_lock);
+ }
+ finish_wait(&ep->resp_wq, &wait);
+ ep->resp = resp;
+ ep->arg = arg;
+ spin_unlock_bh(&ep->ex_lock);
+}
+EXPORT_SYMBOL(fc_seq_set_resp);
+
+/**
+ * fc_exch_abort_locked() - Abort an exchange
+ * @ep: The exchange to be aborted
+ * @timer_msec: The period of time to wait before aborting
+ *
+ * Abort an exchange and sequence. Generally called because of a
+ * exchange timeout or an abort from the upper layer.
+ *
+ * A timer_msec can be specified for abort timeout, if non-zero
+ * timer_msec value is specified then exchange resp handler
+ * will be called with timeout error if no response to abort.
+ *
+ * Locking notes: Called with exch lock held
+ *
+ * Return value: 0 on success else error code
+ */
+static int fc_exch_abort_locked(struct fc_exch *ep,
+ unsigned int timer_msec)
+{
+ struct fc_seq *sp;
+ struct fc_frame *fp;
+ int error;
+
+ FC_EXCH_DBG(ep, "exch: abort, time %d msecs\n", timer_msec);
+ if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
+ ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
+ FC_EXCH_DBG(ep, "exch: already completed esb %x state %x\n",
+ ep->esb_stat, ep->state);
+ return -ENXIO;
+ }
+
+ /*
+ * Send the abort on a new sequence if possible.
+ */
+ sp = fc_seq_start_next_locked(&ep->seq);
+ if (!sp)
+ return -ENOMEM;
+
+ if (timer_msec)
+ fc_exch_timer_set_locked(ep, timer_msec);
+
+ if (ep->sid) {
+ /*
+ * Send an abort for the sequence that timed out.
+ */
+ fp = fc_frame_alloc(ep->lp, 0);
+ if (fp) {
+ ep->esb_stat |= ESB_ST_SEQ_INIT;
+ 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_locked(ep->lp, sp, fp);
+ } else {
+ error = -ENOBUFS;
+ }
+ } else {
+ /*
+ * If not logged into the fabric, don't send ABTS but leave
+ * sequence active until next timeout.
+ */
+ error = 0;
+ }
+ ep->esb_stat |= ESB_ST_ABNORMAL;
+ return error;
+}
+
+/**
+ * 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.
+ *
+ * Return value: 0 on success else error code
+ */
+int fc_seq_exch_abort(const struct fc_seq *req_sp, unsigned int timer_msec)
+{
+ struct fc_exch *ep;
+ int error;
+
+ ep = fc_seq_exch(req_sp);
+ spin_lock_bh(&ep->ex_lock);
+ error = fc_exch_abort_locked(ep, timer_msec);
+ spin_unlock_bh(&ep->ex_lock);
+ return error;
+}
+
+/**
+ * fc_invoke_resp() - invoke ep->resp()
+ *
+ * Notes:
+ * It is assumed that after initialization finished (this means the
+ * first unlock of ex_lock after fc_exch_alloc()) ep->resp and ep->arg are
+ * modified only via fc_seq_set_resp(). This guarantees that none of these
+ * two variables changes if ep->resp_active > 0.
+ *
+ * If an fc_seq_set_resp() call is busy modifying ep->resp and ep->arg when
+ * this function is invoked, the first spin_lock_bh() call in this function
+ * will wait until fc_seq_set_resp() has finished modifying these variables.
+ *
+ * Since fc_exch_done() invokes fc_seq_set_resp() it is guaranteed that that
+ * ep->resp() won't be invoked after fc_exch_done() has returned.
+ *
+ * The response handler itself may invoke fc_exch_done(), which will clear the
+ * ep->resp pointer.
+ *
+ * Return value:
+ * Returns true if and only if ep->resp has been invoked.
+ */
+static bool fc_invoke_resp(struct fc_exch *ep, struct fc_seq *sp,
+ struct fc_frame *fp)
+{
+ void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
+ void *arg;
+ bool res = false;
+
+ spin_lock_bh(&ep->ex_lock);
+ ep->resp_active++;
+ if (ep->resp_task != current)
+ ep->resp_task = !ep->resp_task ? current : NULL;
+ resp = ep->resp;
+ arg = ep->arg;
+ spin_unlock_bh(&ep->ex_lock);
+
+ if (resp) {
+ resp(sp, fp, arg);
+ res = true;
+ }
+
+ spin_lock_bh(&ep->ex_lock);
+ if (--ep->resp_active == 0)
+ ep->resp_task = NULL;
+ spin_unlock_bh(&ep->ex_lock);
+
+ if (ep->resp_active == 0)
+ wake_up(&ep->resp_wq);
+
+ return res;
+}
+
+/**
+ * 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;
+ u32 e_stat;
+ int rc = 1;
+
+ FC_EXCH_DBG(ep, "Exchange timed out state %x\n", ep->state);
+
+ 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 {
+ if (e_stat & ESB_ST_ABNORMAL)
+ rc = fc_exch_done_locked(ep);
+ spin_unlock_bh(&ep->ex_lock);
+ if (!rc)
+ fc_exch_delete(ep);
+ fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_TIMEOUT));
+ fc_seq_set_resp(sp, NULL, ep->arg);
+ 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) {
+ if (!WARN_ON(fc_exch_ptr_get(pool, pool->left))) {
+ index = pool->left;
+ pool->left = FC_XID_UNKNOWN;
+ goto hit;
+ }
+ }
+ if (pool->right != FC_XID_UNKNOWN) {
+ if (!WARN_ON(fc_exch_ptr_get(pool, pool->right))) {
+ 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;
+ ep->resp_active = 0;
+ init_waitqueue_head(&ep->resp_wq);
+ 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 struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
+ struct fc_frame *fp)
+{
+ struct fc_exch_mgr_anchor *ema;
+ struct fc_exch *ep;
+
+ list_for_each_entry(ema, &lport->ema_list, ema_list) {
+ if (!ema->match || ema->match(fp)) {
+ ep = fc_exch_em_alloc(lport, ema->mp);
+ if (ep)
+ return ep;
+ }
+ }
+ 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_lport *lport = mp->lport;
+ struct fc_exch_pool *pool;
+ struct fc_exch *ep = NULL;
+ u16 cpu = xid & fc_cpu_mask;
+
+ if (xid == FC_XID_UNKNOWN)
+ return NULL;
+
+ if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
+ pr_err("host%u: lport %6.6x: xid %d invalid CPU %d\n:",
+ lport->host->host_no, lport->port_id, xid, cpu);
+ return NULL;
+ }
+
+ if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
+ pool = per_cpu_ptr(mp->pool, cpu);
+ spin_lock_bh(&pool->lock);
+ ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
+ if (ep == &fc_quarantine_exch) {
+ FC_LPORT_DBG(lport, "xid %x quarantined\n", xid);
+ ep = NULL;
+ }
+ if (ep) {
+ WARN_ON(ep->xid != xid);
+ fc_exch_hold(ep);
+ }
+ 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
+ *
+ * Note: May sleep if invoked from outside a response handler.
+ */
+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);
+
+ fc_seq_set_resp(sp, NULL, ep->arg);
+ if (!rc)
+ fc_exch_delete(ep);
+}
+EXPORT_SYMBOL(fc_exch_done);
+
+/**
+ * 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;
+ }
+ }
+
+ spin_lock_bh(&ep->ex_lock);
+ /*
+ * 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);
+ if (f_ctl & FC_FC_END_SEQ) {
+ /*
+ * Update sequence_id based on incoming last
+ * frame of sequence exchange. This is needed
+ * for FC target where DDP has been used
+ * on target where, stack is indicated only
+ * about last frame's (payload _header) header.
+ * Whereas "seq_id" which is part of
+ * frame_header is allocated by initiator
+ * which is totally different from "seq_id"
+ * allocated when XFER_RDY was sent by target.
+ * To avoid false -ve which results into not
+ * sending RSP, hence write request on other
+ * end never finishes.
+ */
+ sp->ssb_stat |= SSB_ST_RESP;
+ sp->id = fh->fh_seq_id;
+ } else {
+ spin_unlock_bh(&ep->ex_lock);
+
+ /* sequence/exch should exist */
+ reject = FC_RJT_SEQ_ID;
+ goto rel;
+ }
+ }
+ }
+ WARN_ON(ep != fc_seq_exch(sp));
+
+ if (f_ctl & FC_FC_SEQ_INIT)
+ ep->esb_stat |= ESB_ST_SEQ_INIT;
+ spin_unlock_bh(&ep->ex_lock);
+
+ 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 information 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.
+ */
+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);
+ }
+}
+EXPORT_SYMBOL_GPL(fc_seq_els_rsp_send);
+
+/**
+ * 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_locked(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) {
+ FC_EXCH_DBG(ep, "Drop ACK request, out of memory\n");
+ 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 explanation 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_seq *sp;
+ struct fc_lport *lport;
+ unsigned int f_ctl;
+
+ lport = fr_dev(rx_fp);
+ sp = fr_seq(rx_fp);
+ fp = fc_frame_alloc(lport, sizeof(*rp));
+ if (!fp) {
+ FC_EXCH_DBG(fc_seq_exch(sp),
+ "Drop BA_RJT request, out of memory\n");
+ 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;
+
+ FC_EXCH_DBG(ep, "exch: ABTS received\n");
+ fp = fc_frame_alloc(ep->lp, sizeof(*ap));
+ if (!fp) {
+ FC_EXCH_DBG(ep, "Drop ABTS request, out of memory\n");
+ goto free;
+ }
+
+ spin_lock_bh(&ep->ex_lock);
+ if (ep->esb_stat & ESB_ST_COMPLETE) {
+ spin_unlock_bh(&ep->ex_lock);
+ FC_EXCH_DBG(ep, "exch: ABTS rejected, exchange complete\n");
+ fc_frame_free(fp);
+ goto reject;
+ }
+ if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
+ ep->esb_stat |= ESB_ST_REC_QUAL;
+ fc_exch_hold(ep); /* hold for REC_QUAL */
+ }
+ fc_exch_timer_set_locked(ep, ep->r_a_tov);
+ 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);
+ fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
+ ep->esb_stat |= ESB_ST_ABNORMAL;
+ spin_unlock_bh(&ep->ex_lock);
+
+free:
+ fc_frame_free(rx_fp);
+ return;
+
+reject:
+ fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
+ goto free;
+}
+
+/**
+ * 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().
+ */
+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);
+}
+EXPORT_SYMBOL(fc_seq_assign);
+
+/**
+ * fc_seq_release() - Release the hold
+ * @sp: The sequence.
+ */
+void fc_seq_release(struct fc_seq *sp)
+{
+ fc_exch_release(fc_seq_exch(sp));
+}
+EXPORT_SYMBOL(fc_seq_release);
+
+/**
+ * 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 fc_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 (!fc_invoke_resp(ep, sp, fp))
+ fc_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;
+ 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;
+ }
+
+ f_ctl = ntoh24(fh->fh_f_ctl);
+ fr_seq(fp) = sp;
+
+ spin_lock_bh(&ep->ex_lock);
+ if (f_ctl & FC_FC_SEQ_INIT)
+ ep->esb_stat |= ESB_ST_SEQ_INIT;
+ spin_unlock_bh(&ep->ex_lock);
+
+ if (fc_sof_needs_ack(sof))
+ fc_seq_send_ack(sp, fp);
+
+ 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 (!fc_invoke_resp(ep, sp, fp))
+ 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)
+{
+ 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_DBG(ep, "Exchange timer canceled due to ABTS response\n");
+ 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;
+ }
+
+ /* 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);
+
+ fc_exch_hold(ep);
+ if (!rc)
+ fc_exch_delete(ep);
+ if (!fc_invoke_resp(ep, sp, fp))
+ fc_frame_free(fp);
+ if (has_rec)
+ fc_exch_timer_set(ep, ep->r_a_tov);
+ fc_exch_release(ep);
+}
+
+/**
+ * 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:
+ if (ep)
+ FC_EXCH_DBG(ep, "BLS rctl %x - %s received\n",
+ 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:
+ if (ep)
+ fc_exch_recv_abts(ep, fp);
+ else
+ fc_frame_free(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;
+ struct fc_seq *sp;
+
+ lport = fr_dev(rx_fp);
+ sp = fr_seq(rx_fp);
+ fp = fc_frame_alloc(lport, sizeof(*acc));
+ if (!fp) {
+ FC_EXCH_DBG(fc_seq_exch(sp),
+ "exch: drop LS_ACC, out of memory\n");
+ 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;
+ struct fc_seq *sp;
+
+ lport = fr_dev(rx_fp);
+ sp = fr_seq(rx_fp);
+ fp = fc_frame_alloc(lport, sizeof(*rjt));
+ if (!fp) {
+ FC_EXCH_DBG(fc_seq_exch(sp),
+ "exch: drop LS_ACC, out of memory\n");
+ 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
+ *
+ * Note: May sleep if invoked from outside a response handler.
+ */
+static void fc_exch_reset(struct fc_exch *ep)
+{
+ struct fc_seq *sp;
+ int rc = 1;
+
+ spin_lock_bh(&ep->ex_lock);
+ ep->state |= FC_EX_RST_CLEANUP;
+ fc_exch_timer_cancel(ep);
+ 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;
+ sp = &ep->seq;
+ rc = fc_exch_done_locked(ep);
+ spin_unlock_bh(&ep->ex_lock);
+
+ fc_exch_hold(ep);
+
+ if (!rc)
+ fc_exch_delete(ep);
+
+ fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_CLOSED));
+ fc_seq_set_resp(sp, NULL, ep->arg);
+ fc_exch_release(ep);
+}
+
+/**
+ * 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;
+ }
+ }
+ pool->next_index = 0;
+ pool->left = FC_XID_UNKNOWN;
+ pool->right = FC_XID_UNKNOWN;
+ 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 xid, rxid, 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);
+
+ explan = ELS_EXPL_OXID_RXID;
+ if (sid == fc_host_port_id(lport->host))
+ xid = oxid;
+ else
+ xid = rxid;
+ if (xid == FC_XID_UNKNOWN) {
+ FC_LPORT_DBG(lport,
+ "REC request from %x: invalid rxid %x oxid %x\n",
+ sid, rxid, oxid);
+ goto reject;
+ }
+ ep = fc_exch_lookup(lport, xid);
+ if (!ep) {
+ FC_LPORT_DBG(lport,
+ "REC request from %x: rxid %x oxid %x not found\n",
+ sid, rxid, oxid);
+ goto reject;
+ }
+ FC_EXCH_DBG(ep, "REC request from %x: rxid %x oxid %x\n",
+ sid, rxid, oxid);
+ 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) {
+ FC_EXCH_DBG(ep, "Drop REC request, out of memory\n");
+ 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\n");
+ /* fall through */
+ case ELS_LS_ACC:
+ goto cleanup;
+ default:
+ FC_EXCH_DBG(aborted_ep, "unexpected response op %x for RRQ\n",
+ 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 exchange response handler is set in this routine to resp()
+ * function pointer. It can be called in two scenarios: if a timeout
+ * occurs or if a response frame is received for the exchange. The
+ * fc_frame pointer in response handler will also indicate timeout
+ * as error using IS_ERR related macros.
+ *
+ * The exchange destructor handler is also set in this routine.
+ * The destructor handler is invoked by EM layer when exchange
+ * is about to free, this can be used by caller to free its
+ * resources along with exchange free.
+ *
+ * The arg is passed back to resp and destructor handler.
+ *
+ * The timeout value (in msec) for an exchange is set if non zero
+ * timer_msec argument is specified. The timer is canceled when
+ * it fires or when the exchange is done. The exchange timeout handler
+ * is registered by EM layer.
+ *
+ * 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
+ */
+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;
+ struct fc_fcp_pkt *fsp = NULL;
+ 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 = lport->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) {
+ fsp = fr_fsp(fp);
+ 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:
+ if (fsp)
+ fc_fcp_ddp_done(fsp);
+ rc = fc_exch_done_locked(ep);
+ spin_unlock_bh(&ep->ex_lock);
+ if (!rc)
+ fc_exch_delete(ep);
+ return NULL;
+}
+EXPORT_SYMBOL(fc_exch_seq_send);
+
+/**
+ * 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:
+ FC_EXCH_DBG(ep, "exch: RRQ send failed\n");
+ 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);
+ FC_EXCH_DBG(ep, "RRQ request from %x: xid %x rxid %x oxid %x\n",
+ sid, xid, ntohs(rp->rrq_rx_id), ntohs(rp->rrq_ox_id));
+ 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)
+ fc_exch_timer_cancel(ep);
+
+ 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_update_stats() - update exches stats to lport
+ * @lport: The local port to update exchange manager stats
+ */
+void fc_exch_update_stats(struct fc_lport *lport)
+{
+ struct fc_host_statistics *st;
+ struct fc_exch_mgr_anchor *ema;
+ struct fc_exch_mgr *mp;
+
+ st = &lport->host_stats;
+
+ list_for_each_entry(ema, &lport->ema_list, ema_list) {
+ mp = ema->mp;
+ st->fc_no_free_exch += atomic_read(&mp->stats.no_free_exch);
+ st->fc_no_free_exch_xid +=
+ atomic_read(&mp->stats.no_free_exch_xid);
+ st->fc_xid_not_found += atomic_read(&mp->stats.xid_not_found);
+ st->fc_xid_busy += atomic_read(&mp->stats.xid_busy);
+ st->fc_seq_not_found += atomic_read(&mp->stats.seq_not_found);
+ st->fc_non_bls_resp += atomic_read(&mp->stats.non_bls_resp);
+ }
+}
+EXPORT_SYMBOL(fc_exch_update_stats);
+
+/**
+ * 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;
+}
+EXPORT_SYMBOL(fc_exch_mgr_list_clone);
+
+/**
+ * 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;
+ mp->lport = lport;
+ /* adjust em exch xid range for offload */
+ mp->min_xid = min_xid;
+
+ /* reduce range so per cpu pool fits into PCPU_MIN_UNIT_SIZE pool */
+ pool_exch_range = (PCPU_MIN_UNIT_SIZE - sizeof(*pool)) /
+ sizeof(struct fc_exch *);
+ if ((max_xid - min_xid + 1) / (fc_cpu_mask + 1) > pool_exch_range) {
+ mp->max_xid = pool_exch_range * (fc_cpu_mask + 1) +
+ min_xid - 1;
+ } else {
+ mp->max_xid = max_xid;
+ pool_exch_range = (mp->max_xid - mp->min_xid + 1) /
+ (fc_cpu_mask + 1);
+ }
+
+ 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.
+ */
+ 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->next_index = 0;
+ 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_find_ema() - Lookup and return appropriate Exchange Manager Anchor depending
+ * upon 'xid'.
+ * @f_ctl: f_ctl
+ * @lport: The local port the frame was received on
+ * @fh: The received frame header
+ */
+static struct fc_exch_mgr_anchor *fc_find_ema(u32 f_ctl,
+ struct fc_lport *lport,
+ struct fc_frame_header *fh)
+{
+ struct fc_exch_mgr_anchor *ema;
+ u16 xid;
+
+ if (f_ctl & FC_FC_EX_CTX)
+ xid = ntohs(fh->fh_ox_id);
+ else {
+ xid = ntohs(fh->fh_rx_id);
+ if (xid == FC_XID_UNKNOWN)
+ return list_entry(lport->ema_list.prev,
+ typeof(*ema), ema_list);
+ }
+
+ list_for_each_entry(ema, &lport->ema_list, ema_list) {
+ if ((xid >= ema->mp->min_xid) &&
+ (xid <= ema->mp->max_xid))
+ return ema;
+ }
+ return NULL;
+}
+/**
+ * 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;
+
+ /* 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);
+ ema = fc_find_ema(f_ctl, lport, fh);
+ if (!ema) {
+ FC_LPORT_DBG(lport, "Unable to find Exchange Manager Anchor,"
+ "fc_ctl <0x%x>, xid <0x%x>\n",
+ f_ctl,
+ (f_ctl & FC_FC_EX_CTX) ?
+ ntohs(fh->fh_ox_id) :
+ ntohs(fh->fh_rx_id));
+ fc_frame_free(fp);
+ return;
+ }
+
+ /*
+ * 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.exch_mgr_reset)
+ lport->tt.exch_mgr_reset = fc_exch_mgr_reset;
+
+ 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_order = ilog2(roundup_pow_of_two(nr_cpu_ids));
+ fc_cpu_mask = (1 << fc_cpu_order) - 1;
+
+ fc_exch_workqueue = create_singlethread_workqueue("fc_exch_workqueue");
+ if (!fc_exch_workqueue)
+ goto err;
+ return 0;
+err:
+ kmem_cache_destroy(fc_em_cachep);
+ return -ENOMEM;
+}
+
+/**
+ * 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);
+}