diff options
Diffstat (limited to 'drivers/scsi/libfc/fc_exch.c')
| -rw-r--r-- | drivers/scsi/libfc/fc_exch.c | 2714 |
1 files changed, 2714 insertions, 0 deletions
diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c new file mode 100644 index 000000000..4261380af --- /dev/null +++ b/drivers/scsi/libfc/fc_exch.c @@ -0,0 +1,2714 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright(c) 2007 Intel Corporation. All rights reserved. + * Copyright(c) 2008 Red Hat, Inc. All rights reserved. + * Copyright(c) 2008 Mike Christie + * + * 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 + * @left: Cache of free slot in exch array + * @right: Cache of free slot in exch array + * + * 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; + + 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 + * @lport: Local exchange port + * @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() + * @ep: The exchange to be operated on + * @fp: The frame pointer to pass through to ->resp() + * @sp: The sequence pointer to pass through to ->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); + } else { + FC_EXCH_DBG(ep, "ep is completed already," + "hence skip calling the resp\n"); + goto skip_resp; + } + } + + /* + * 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); + +skip_resp: + 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 */ + return; + } + + 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); + } else { + FC_EXCH_DBG(ep, "ep is completed already," + "hence skip calling the resp\n"); + goto skip_resp; + } + + fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_CLOSED)); +skip_resp: + 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"); + fallthrough; + 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_LIBFC_DBG("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)); + fallthrough; + 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); +} |