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linux-sg2042/drivers/scsi/libfc/fc_exch.c

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/*
* 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/gfp.h>
#include <linux/err.h>
#include <scsi/fc/fc_fc2.h>
#include <scsi/libfc.h>
#include <scsi/fc_encode.h>
/*
* fc_exch_debug can be set in debugger or at compile time to get more logs.
*/
static int fc_exch_debug;
#define FC_DEBUG_EXCH(fmt...) \
do { \
if (fc_exch_debug) \
FC_DBG(fmt); \
} while (0)
static struct kmem_cache *fc_em_cachep; /* cache for exchanges */
/*
* 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.
*/
/*
* Exchange manager.
*
* This structure is the center for creating exchanges and sequences.
* It manages the allocation of exchange IDs.
*/
struct fc_exch_mgr {
enum fc_class class; /* default class for sequences */
spinlock_t em_lock; /* exchange manager lock,
must be taken before ex_lock */
u16 last_xid; /* last allocated exchange ID */
u16 min_xid; /* min exchange ID */
u16 max_xid; /* max exchange ID */
u16 max_read; /* max exchange ID for read */
u16 last_read; /* last xid allocated for read */
u32 total_exches; /* total allocated exchanges */
struct list_head ex_list; /* allocated exchanges list */
struct fc_lport *lp; /* fc device instance */
mempool_t *ep_pool; /* reserve ep's */
/*
* currently exchange mgr stats are updated but not used.
* either stats can be expose via sysfs or remove them
* all together if not used XXX
*/
struct {
atomic_t no_free_exch;
atomic_t no_free_exch_xid;
atomic_t xid_not_found;
atomic_t xid_busy;
atomic_t seq_not_found;
atomic_t non_bls_resp;
} stats;
struct fc_exch **exches; /* for exch pointers indexed by xid */
};
#define fc_seq_exch(sp) container_of(sp, struct fc_exch, seq)
static void fc_exch_rrq(struct fc_exch *);
static void fc_seq_ls_acc(struct fc_seq *);
static void fc_seq_ls_rjt(struct fc_seq *, enum fc_els_rjt_reason,
enum fc_els_rjt_explan);
static void fc_exch_els_rec(struct fc_seq *, struct fc_frame *);
static void fc_exch_els_rrq(struct fc_seq *, struct fc_frame *);
static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp);
/*
* 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_lock and ex_lock must be taken at the same time, then the
* em_lock must be taken before the ex_lock.
*/
/*
* opcode names for debugging.
*/
static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;
#define FC_TABLE_SIZE(x) (sizeof(x) / sizeof(x[0]))
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;
}
static const char *fc_exch_rctl_name(unsigned int op)
{
return fc_exch_name_lookup(op, fc_exch_rctl_names,
FC_TABLE_SIZE(fc_exch_rctl_names));
}
/*
* Hold an exchange - keep it from being freed.
*/
static void fc_exch_hold(struct fc_exch *ep)
{
atomic_inc(&ep->ex_refcnt);
}
/*
* setup fc hdr by initializing few more FC header fields and sof/eof.
* Initialized fields by this func:
* - fh_ox_id, fh_rx_id, fh_seq_id, fh_seq_cnt
* - 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;
/*
* Form f_ctl.
* The number of fill bytes to make the length a 4-byte
* multiple is the low order 2-bits of the f_ctl.
* The fill itself will have been cleared by the frame
* allocation.
* After this, the length will be even, as expected by
* the transport.
*/
fill = fr_len(fp) & 3;
if (fill) {
fill = 4 - fill;
/* TODO, this may be a problem with fragmented skb */
skb_put(fp_skb(fp), fill);
hton24(fh->fh_f_ctl, f_ctl | fill);
}
} else {
WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
fr_eof(fp) = FC_EOF_N;
}
/*
* Initialize remainig fh fields
* from fc_fill_fc_hdr
*/
fh->fh_ox_id = htons(ep->oxid);
fh->fh_rx_id = htons(ep->rxid);
fh->fh_seq_id = ep->seq.id;
fh->fh_seq_cnt = htons(ep->seq.cnt);
}
/*
* Release a reference to an exchange.
* If the refcnt goes to 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);
if (ep->lp->tt.exch_put)
ep->lp->tt.exch_put(ep->lp, mp, ep->xid);
WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));
mempool_free(ep, mp->ep_pool);
}
}
static int fc_exch_done_locked(struct fc_exch *ep)
{
int rc = 1;
/*
* We must check for completion in case there are two threads
* tyring to complete this. But the rrq code will reuse the
* ep, and in that case we only clear the resp and set it as
* complete, so it can be reused by the timer to send the rrq.
*/
ep->resp = NULL;
if (ep->state & FC_EX_DONE)
return rc;
ep->esb_stat |= ESB_ST_COMPLETE;
if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
ep->state |= FC_EX_DONE;
if (cancel_delayed_work(&ep->timeout_work))
atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
rc = 0;
}
return rc;
}
static void fc_exch_mgr_delete_ep(struct fc_exch *ep)
{
struct fc_exch_mgr *mp;
mp = ep->em;
spin_lock_bh(&mp->em_lock);
WARN_ON(mp->total_exches <= 0);
mp->total_exches--;
mp->exches[ep->xid - mp->min_xid] = NULL;
list_del(&ep->ex_list);
spin_unlock_bh(&mp->em_lock);
fc_exch_release(ep); /* drop hold for exch in mp */
}
/*
* Internal version of fc_exch_timer_set - used with lock held.
*/
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_DEBUG_EXCH("Exchange (%4x) timed out, notifying the upper layer\n",
ep->xid);
if (schedule_delayed_work(&ep->timeout_work,
msecs_to_jiffies(timer_msec)))
fc_exch_hold(ep); /* hold for timer */
}
/*
* Set timer for an exchange.
* The time is a minimum delay in milliseconds until the timer fires.
* Used for upper level protocols to time out the exchange.
* The timer is cancelled when it fires or when the exchange completes.
* Returns non-zero if a timer couldn't be allocated.
*/
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);
}
int fc_seq_exch_abort(const struct fc_seq *req_sp, unsigned int timer_msec)
{
struct fc_seq *sp;
struct fc_exch *ep;
struct fc_frame *fp;
int error;
ep = fc_seq_exch(req_sp);
spin_lock_bh(&ep->ex_lock);
if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
spin_unlock_bh(&ep->ex_lock);
return -ENXIO;
}
/*
* Send the abort on a new sequence if possible.
*/
sp = fc_seq_start_next_locked(&ep->seq);
if (!sp) {
spin_unlock_bh(&ep->ex_lock);
return -ENOMEM;
}
ep->esb_stat |= ESB_ST_SEQ_INIT | ESB_ST_ABNORMAL;
if (timer_msec)
fc_exch_timer_set_locked(ep, timer_msec);
spin_unlock_bh(&ep->ex_lock);
/*
* If not logged into the fabric, don't send ABTS but leave
* sequence active until next timeout.
*/
if (!ep->sid)
return 0;
/*
* Send an abort for the sequence that timed out.
*/
fp = fc_frame_alloc(ep->lp, 0);
if (fp) {
fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
FC_TYPE_BLS, FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
error = fc_seq_send(ep->lp, sp, fp);
} else
error = -ENOBUFS;
return error;
}
EXPORT_SYMBOL(fc_seq_exch_abort);
/*
* Exchange timeout - handle exchange timer expiration.
* The timer will have been cancelled before this is called.
*/
static void fc_exch_timeout(struct work_struct *work)
{
struct fc_exch *ep = container_of(work, struct fc_exch,
timeout_work.work);
struct fc_seq *sp = &ep->seq;
void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
void *arg;
u32 e_stat;
int rc = 1;
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;
if (e_stat & ESB_ST_REC_QUAL)
fc_exch_rrq(ep);
spin_unlock_bh(&ep->ex_lock);
goto done;
} else {
resp = ep->resp;
arg = ep->arg;
ep->resp = NULL;
if (e_stat & ESB_ST_ABNORMAL)
rc = fc_exch_done_locked(ep);
spin_unlock_bh(&ep->ex_lock);
if (!rc)
fc_exch_mgr_delete_ep(ep);
if (resp)
resp(sp, ERR_PTR(-FC_EX_TIMEOUT), 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);
}
/*
* Allocate a sequence.
*
* 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_em_alloc_xid - returns an xid based on request type
* @lp : ptr to associated lport
* @fp : ptr to the assocated frame
*
* check the associated fc_fsp_pkt to get scsi command type and
* command direction to decide from which range this exch id
* will be allocated from.
*
* Returns : 0 or an valid xid
*/
static u16 fc_em_alloc_xid(struct fc_exch_mgr *mp, const struct fc_frame *fp)
{
u16 xid, min, max;
u16 *plast;
struct fc_exch *ep = NULL;
if (mp->max_read) {
if (fc_fcp_is_read(fr_fsp(fp))) {
min = mp->min_xid;
max = mp->max_read;
plast = &mp->last_read;
} else {
min = mp->max_read + 1;
max = mp->max_xid;
plast = &mp->last_xid;
}
} else {
min = mp->min_xid;
max = mp->max_xid;
plast = &mp->last_xid;
}
xid = *plast;
do {
xid = (xid == max) ? min : xid + 1;
ep = mp->exches[xid - mp->min_xid];
} while ((ep != NULL) && (xid != *plast));
if (unlikely(ep))
xid = 0;
else
*plast = xid;
return xid;
}
/*
* fc_exch_alloc - allocate an exchange.
* @mp : ptr to the exchange manager
* @xid: input xid
*
* if xid is supplied zero then assign next free exchange ID
* from exchange manager, otherwise use supplied xid.
* Returns with exch lock held.
*/
struct fc_exch *fc_exch_alloc(struct fc_exch_mgr *mp,
struct fc_frame *fp, u16 xid)
{
struct fc_exch *ep;
/* 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));
spin_lock_bh(&mp->em_lock);
/* alloc xid if input xid 0 */
if (!xid) {
/* alloc a new xid */
xid = fc_em_alloc_xid(mp, fp);
if (!xid) {
printk(KERN_ERR "fc_em_alloc_xid() failed\n");
goto err;
}
}
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);
mp->exches[xid - mp->min_xid] = ep;
list_add_tail(&ep->ex_list, &mp->ex_list);
fc_seq_alloc(ep, ep->seq_id++);
mp->total_exches++;
spin_unlock_bh(&mp->em_lock);
/*
* update exchange
*/
ep->oxid = ep->xid = xid;
ep->em = mp;
ep->lp = mp->lp;
ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
ep->rxid = FC_XID_UNKNOWN;
ep->class = mp->class;
INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
out:
return ep;
err:
spin_unlock_bh(&mp->em_lock);
atomic_inc(&mp->stats.no_free_exch_xid);
mempool_free(ep, mp->ep_pool);
return NULL;
}
EXPORT_SYMBOL(fc_exch_alloc);
/*
* Lookup and hold an exchange.
*/
static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
{
struct fc_exch *ep = NULL;
if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
spin_lock_bh(&mp->em_lock);
ep = mp->exches[xid - mp->min_xid];
if (ep) {
fc_exch_hold(ep);
WARN_ON(ep->xid != xid);
}
spin_unlock_bh(&mp->em_lock);
}
return ep;
}
void fc_exch_done(struct fc_seq *sp)
{
struct fc_exch *ep = fc_seq_exch(sp);
int rc;
spin_lock_bh(&ep->ex_lock);
rc = fc_exch_done_locked(ep);
spin_unlock_bh(&ep->ex_lock);
if (!rc)
fc_exch_mgr_delete_ep(ep);
}
EXPORT_SYMBOL(fc_exch_done);
/*
* Allocate a new exchange as responder.
* Sets the responder ID in the frame header.
*/
static struct fc_exch *fc_exch_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
{
struct fc_exch *ep;
struct fc_frame_header *fh;
ep = mp->lp->tt.exch_get(mp->lp, 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 exch_get */
}
return ep;
}
/*
* Find a sequence for receive where the other end is originating the sequence.
* 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_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(mp, fp);
if (!ep) {
reject = FC_RJT_EXCH_EST; /* XXX */
goto out;
}
xid = ep->xid; /* get our XID */
} else if (!ep) {
atomic_inc(&mp->stats.xid_not_found);
reject = FC_RJT_RX_ID; /* XID not found */
goto out;
}
}
/*
* At this point, we have the exchange held.
* Find or create the sequence.
*/
if (fc_sof_is_init(fr_sof(fp))) {
sp = fc_seq_start_next(&ep->seq);
if (!sp) {
reject = FC_RJT_SEQ_XS; /* exchange shortage */
goto rel;
}
sp->id = fh->fh_seq_id;
sp->ssb_stat |= SSB_ST_RESP;
} else {
sp = &ep->seq;
if (sp->id != fh->fh_seq_id) {
atomic_inc(&mp->stats.seq_not_found);
reject = FC_RJT_SEQ_ID; /* sequence/exch should exist */
goto rel;
}
}
WARN_ON(ep != fc_seq_exch(sp));
if (f_ctl & FC_FC_SEQ_INIT)
ep->esb_stat |= ESB_ST_SEQ_INIT;
fr_seq(fp) = sp;
out:
return reject;
rel:
fc_exch_done(&ep->seq);
fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
return reject;
}
/*
* Find the sequence for a frame being received.
* We originated the sequence, so it should be found.
* We may or may not have originated the exchange.
* 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;
}
/*
* Set addresses for an exchange.
* 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;
}
}
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_DEBUG_EXCH("exch %4x f_ctl %6x seq %2x\n",
ep->xid, ep->f_ctl, sp->id);
return sp;
}
/*
* Allocate a new sequence on the same exchange as the supplied sequence.
* This will never return NULL.
*/
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);
WARN_ON((ep->esb_stat & ESB_ST_COMPLETE) != 0);
sp = fc_seq_start_next_locked(sp);
spin_unlock_bh(&ep->ex_lock);
return sp;
}
EXPORT_SYMBOL(fc_seq_start_next);
int fc_seq_send(struct fc_lport *lp, struct fc_seq *sp, struct fc_frame *fp)
{
struct fc_exch *ep;
struct fc_frame_header *fh = fc_frame_header_get(fp);
int error;
u32 f_ctl;
ep = fc_seq_exch(sp);
WARN_ON((ep->esb_stat & ESB_ST_SEQ_INIT) != ESB_ST_SEQ_INIT);
f_ctl = ntoh24(fh->fh_f_ctl);
fc_exch_setup_hdr(ep, fp, f_ctl);
/*
* 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 = lp->tt.frame_send(lp, fp);
/*
* Update the exchange and sequence flags,
* assuming all frames for the sequence have been sent.
* We can only be called to send once for each sequence.
*/
spin_lock_bh(&ep->ex_lock);
ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
if (f_ctl & (FC_FC_END_SEQ | FC_FC_SEQ_INIT))
ep->esb_stat &= ~ESB_ST_SEQ_INIT;
spin_unlock_bh(&ep->ex_lock);
return error;
}
EXPORT_SYMBOL(fc_seq_send);
void fc_seq_els_rsp_send(struct fc_seq *sp, enum fc_els_cmd els_cmd,
struct fc_seq_els_data *els_data)
{
switch (els_cmd) {
case ELS_LS_RJT:
fc_seq_ls_rjt(sp, els_data->reason, els_data->explan);
break;
case ELS_LS_ACC:
fc_seq_ls_acc(sp);
break;
case ELS_RRQ:
fc_exch_els_rrq(sp, els_data->fp);
break;
case ELS_REC:
fc_exch_els_rec(sp, els_data->fp);
break;
default:
FC_DBG("Invalid ELS CMD:%x\n", els_cmd);
}
}
EXPORT_SYMBOL(fc_seq_els_rsp_send);
/*
* Send a sequence, which is also the last sequence in the exchange.
*/
static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
enum fc_rctl rctl, enum fc_fh_type fh_type)
{
u32 f_ctl;
struct fc_exch *ep = fc_seq_exch(sp);
f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
f_ctl |= ep->f_ctl;
fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
fc_seq_send(ep->lp, sp, fp);
}
/*
* Send ACK_1 (or equiv.) indicating we received something.
* The frame we're acking is supplied.
*/
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 *lp = 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(lp, 0);
if (!fp)
return;
fh = fc_frame_header_get(fp);
fh->fh_r_ctl = FC_RCTL_ACK_1;
fh->fh_type = FC_TYPE_BLS;
/*
* Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
* Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
* Bits 9-8 are meaningful (retransmitted or unidirectional).
* Last ACK uses bits 7-6 (continue sequence),
* bits 5-4 are meaningful (what kind of ACK to use).
*/
rx_fh = fc_frame_header_get(rx_fp);
f_ctl = ntoh24(rx_fh->fh_f_ctl);
f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
FC_FC_RETX_SEQ | FC_FC_UNI_TX;
f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
hton24(fh->fh_f_ctl, f_ctl);
fc_exch_setup_hdr(ep, fp, f_ctl);
fh->fh_seq_id = rx_fh->fh_seq_id;
fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
fh->fh_parm_offset = htonl(1); /* ack single frame */
fr_sof(fp) = fr_sof(rx_fp);
if (f_ctl & FC_FC_END_SEQ)
fr_eof(fp) = FC_EOF_T;
else
fr_eof(fp) = FC_EOF_N;
(void) lp->tt.frame_send(lp, fp);
}
}
/*
* Send BLS Reject.
* This is for rejecting BA_ABTS only.
*/
static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
enum fc_ba_rjt_reason reason,
enum fc_ba_rjt_explan explan)
{
struct fc_frame *fp;
struct fc_frame_header *rx_fh;
struct fc_frame_header *fh;
struct fc_ba_rjt *rp;
struct fc_lport *lp;
unsigned int f_ctl;
lp = fr_dev(rx_fp);
fp = fc_frame_alloc(lp, sizeof(*rp));
if (!fp)
return;
fh = fc_frame_header_get(fp);
rx_fh = fc_frame_header_get(rx_fp);
memset(fh, 0, sizeof(*fh) + sizeof(*rp));
rp = fc_frame_payload_get(fp, sizeof(*rp));
rp->br_reason = reason;
rp->br_explan = explan;
/*
* seq_id, cs_ctl, df_ctl and param/offset are zero.
*/
memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
fh->fh_ox_id = rx_fh->fh_rx_id;
fh->fh_rx_id = rx_fh->fh_ox_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;
(void) lp->tt.frame_send(lp, fp);
}
/*
* Handle an incoming ABTS. This would be for target mode usually,
* but could be due to lost FCP transfer ready, confirm or RRQ.
* We always handle this as an exchange abort, ignoring the parameter.
*/
static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
{
struct fc_frame *fp;
struct fc_ba_acc *ap;
struct fc_frame_header *fh;
struct fc_seq *sp;
if (!ep)
goto reject;
spin_lock_bh(&ep->ex_lock);
if (ep->esb_stat & ESB_ST_COMPLETE) {
spin_unlock_bh(&ep->ex_lock);
goto reject;
}
if (!(ep->esb_stat & ESB_ST_REC_QUAL))
fc_exch_hold(ep); /* hold for REC_QUAL */
ep->esb_stat |= ESB_ST_ABNORMAL | ESB_ST_REC_QUAL;
fc_exch_timer_set_locked(ep, ep->r_a_tov);
fp = fc_frame_alloc(ep->lp, sizeof(*ap));
if (!fp) {
spin_unlock_bh(&ep->ex_lock);
goto free;
}
fh = fc_frame_header_get(fp);
ap = fc_frame_payload_get(fp, sizeof(*ap));
memset(ap, 0, sizeof(*ap));
sp = &ep->seq;
ap->ba_high_seq_cnt = htons(0xffff);
if (sp->ssb_stat & SSB_ST_RESP) {
ap->ba_seq_id = sp->id;
ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
ap->ba_high_seq_cnt = fh->fh_seq_cnt;
ap->ba_low_seq_cnt = htons(sp->cnt);
}
sp = fc_seq_start_next_locked(sp);
spin_unlock_bh(&ep->ex_lock);
fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
fc_frame_free(rx_fp);
return;
reject:
fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
free:
fc_frame_free(rx_fp);
}
/*
* Handle receive where the other end is originating the sequence.
*/
static void fc_exch_recv_req(struct fc_lport *lp, 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_sof sof;
enum fc_eof eof;
u32 f_ctl;
enum fc_pf_rjt_reason reject;
fr_seq(fp) = NULL;
reject = fc_seq_lookup_recip(mp, fp);
if (reject == FC_RJT_NONE) {
sp = fr_seq(fp); /* sequence will be held */
ep = fc_seq_exch(sp);
sof = fr_sof(fp);
eof = fr_eof(fp);
f_ctl = ntoh24(fh->fh_f_ctl);
fc_seq_send_ack(sp, fp);
/*
* Call the receive function.
*
* The receive function may allocate a new sequence
* over the old one, so we shouldn't change the
* sequence after this.
*
* The frame will be freed by the receive function.
* If new exch resp handler is valid then call that
* first.
*/
if (ep->resp)
ep->resp(sp, fp, ep->arg);
else
lp->tt.lport_recv(lp, sp, fp);
fc_exch_release(ep); /* release from lookup */
} else {
FC_DEBUG_EXCH("exch/seq lookup failed: reject %x\n", reject);
fc_frame_free(fp);
}
}
/*
* Handle receive where the other end is originating the sequence in
* response to our exchange.
*/
static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
{
struct fc_frame_header *fh = fc_frame_header_get(fp);
struct fc_seq *sp;
struct fc_exch *ep;
enum fc_sof sof;
u32 f_ctl;
void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
void *ex_resp_arg;
int rc;
ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
if (!ep) {
atomic_inc(&mp->stats.xid_not_found);
goto out;
}
if (ep->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);
if (fc_sof_is_init(sof)) {
sp = fc_seq_start_next(&ep->seq);
sp->id = fh->fh_seq_id;
sp->ssb_stat |= SSB_ST_RESP;
} else {
sp = &ep->seq;
if (sp->id != fh->fh_seq_id) {
atomic_inc(&mp->stats.seq_not_found);
goto rel;
}
}
f_ctl = ntoh24(fh->fh_f_ctl);
fr_seq(fp) = sp;
if (f_ctl & FC_FC_SEQ_INIT)
ep->esb_stat |= ESB_ST_SEQ_INIT;
if (fc_sof_needs_ack(sof))
fc_seq_send_ack(sp, fp);
resp = ep->resp;
ex_resp_arg = ep->arg;
if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
(f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
(FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
spin_lock_bh(&ep->ex_lock);
rc = fc_exch_done_locked(ep);
WARN_ON(fc_seq_exch(sp) != ep);
spin_unlock_bh(&ep->ex_lock);
if (!rc)
fc_exch_mgr_delete_ep(ep);
}
/*
* Call the receive function.
* The sequence is held (has a refcnt) for us,
* but not for the receive function.
*
* The receive function may allocate a new sequence
* over the old one, so we shouldn't change the
* sequence after this.
*
* The frame will be freed by the receive function.
* If new exch resp handler is valid then call that
* first.
*/
if (resp)
resp(sp, fp, ex_resp_arg);
else
fc_frame_free(fp);
fc_exch_release(ep);
return;
rel:
fc_exch_release(ep);
out:
fc_frame_free(fp);
}
/*
* Handle receive for a sequence where other end is responding to our sequence.
*/
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);
FC_DEBUG_EXCH("seq lookup failed\n");
} else {
atomic_inc(&mp->stats.non_bls_resp);
FC_DEBUG_EXCH("non-BLS response to sequence");
}
fc_frame_free(fp);
}
/*
* Handle the response to an ABTS for exchange or sequence.
* This can be BA_ACC or BA_RJT.
*/
static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
{
void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
void *ex_resp_arg;
struct fc_frame_header *fh;
struct fc_ba_acc *ap;
struct fc_seq *sp;
u16 low;
u16 high;
int rc = 1, has_rec = 0;
fh = fc_frame_header_get(fp);
FC_DEBUG_EXCH("exch: BLS rctl %x - %s\n",
fh->fh_r_ctl, fc_exch_rctl_name(fh->fh_r_ctl));
if (cancel_delayed_work_sync(&ep->timeout_work))
fc_exch_release(ep); /* release from pending timer hold */
spin_lock_bh(&ep->ex_lock);
switch (fh->fh_r_ctl) {
case FC_RCTL_BA_ACC:
ap = fc_frame_payload_get(fp, sizeof(*ap));
if (!ap)
break;
/*
* Decide whether to establish a Recovery Qualifier.
* We do this if there is a non-empty SEQ_CNT range and
* SEQ_ID is the same as the one we aborted.
*/
low = ntohs(ap->ba_low_seq_cnt);
high = ntohs(ap->ba_high_seq_cnt);
if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
(ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
ap->ba_seq_id == ep->seq_id) && low != high) {
ep->esb_stat |= ESB_ST_REC_QUAL;
fc_exch_hold(ep); /* hold for recovery qualifier */
has_rec = 1;
}
break;
case FC_RCTL_BA_RJT:
break;
default:
break;
}
resp = ep->resp;
ex_resp_arg = ep->arg;
/* do we need to do some other checks here. Can we reuse more of
* fc_exch_recv_seq_resp
*/
sp = &ep->seq;
/*
* do we want to check END_SEQ as well as LAST_SEQ here?
*/
if (ep->fh_type != FC_TYPE_FCP &&
ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
rc = fc_exch_done_locked(ep);
spin_unlock_bh(&ep->ex_lock);
if (!rc)
fc_exch_mgr_delete_ep(ep);
if (resp)
resp(sp, fp, ex_resp_arg);
else
fc_frame_free(fp);
if (has_rec)
fc_exch_timer_set(ep, ep->r_a_tov);
}
/*
* Receive BLS sequence.
* This is always a sequence initiated by the remote side.
* We may be either the originator or recipient of the exchange.
*/
static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
{
struct fc_frame_header *fh;
struct fc_exch *ep;
u32 f_ctl;
fh = fc_frame_header_get(fp);
f_ctl = ntoh24(fh->fh_f_ctl);
fr_seq(fp) = NULL;
ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
spin_lock_bh(&ep->ex_lock);
ep->esb_stat |= ESB_ST_SEQ_INIT;
spin_unlock_bh(&ep->ex_lock);
}
if (f_ctl & FC_FC_SEQ_CTX) {
/*
* A response to a sequence we initiated.
* This should only be ACKs for class 2 or F.
*/
switch (fh->fh_r_ctl) {
case FC_RCTL_ACK_1:
case FC_RCTL_ACK_0:
break;
default:
FC_DEBUG_EXCH("BLS rctl %x - %s received",
fh->fh_r_ctl,
fc_exch_rctl_name(fh->fh_r_ctl));
break;
}
fc_frame_free(fp);
} else {
switch (fh->fh_r_ctl) {
case FC_RCTL_BA_RJT:
case FC_RCTL_BA_ACC:
if (ep)
fc_exch_abts_resp(ep, fp);
else
fc_frame_free(fp);
break;
case FC_RCTL_BA_ABTS:
fc_exch_recv_abts(ep, fp);
break;
default: /* ignore junk */
fc_frame_free(fp);
break;
}
}
if (ep)
fc_exch_release(ep); /* release hold taken by fc_exch_find */
}
/*
* Accept sequence with LS_ACC.
* If this fails due to allocation or transmit congestion, assume the
* originator will repeat the sequence.
*/
static void fc_seq_ls_acc(struct fc_seq *req_sp)
{
struct fc_seq *sp;
struct fc_els_ls_acc *acc;
struct fc_frame *fp;
sp = fc_seq_start_next(req_sp);
fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*acc));
if (fp) {
acc = fc_frame_payload_get(fp, sizeof(*acc));
memset(acc, 0, sizeof(*acc));
acc->la_cmd = ELS_LS_ACC;
fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
}
}
/*
* Reject sequence with ELS LS_RJT.
* If this fails due to allocation or transmit congestion, assume the
* originator will repeat the sequence.
*/
static void fc_seq_ls_rjt(struct fc_seq *req_sp, enum fc_els_rjt_reason reason,
enum fc_els_rjt_explan explan)
{
struct fc_seq *sp;
struct fc_els_ls_rjt *rjt;
struct fc_frame *fp;
sp = fc_seq_start_next(req_sp);
fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*rjt));
if (fp) {
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_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
}
}
static void fc_exch_reset(struct fc_exch *ep)
{
struct fc_seq *sp;
void (*resp)(struct fc_seq *, struct fc_frame *, void *);
void *arg;
int rc = 1;
spin_lock_bh(&ep->ex_lock);
ep->state |= FC_EX_RST_CLEANUP;
/*
* we really want to call del_timer_sync, but cannot due
* to the lport calling with the lport lock held (some resp
* functions can also grab the lport lock which could cause
* a deadlock).
*/
if (cancel_delayed_work(&ep->timeout_work))
atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
resp = ep->resp;
ep->resp = NULL;
if (ep->esb_stat & ESB_ST_REC_QUAL)
atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
ep->esb_stat &= ~ESB_ST_REC_QUAL;
arg = ep->arg;
sp = &ep->seq;
rc = fc_exch_done_locked(ep);
spin_unlock_bh(&ep->ex_lock);
if (!rc)
fc_exch_mgr_delete_ep(ep);
if (resp)
resp(sp, ERR_PTR(-FC_EX_CLOSED), arg);
}
/*
* Reset an exchange manager, releasing all sequences and exchanges.
* If sid is non-zero, reset only exchanges we source from that FID.
* If did is non-zero, reset only exchanges destined to that FID.
*/
void fc_exch_mgr_reset(struct fc_lport *lp, u32 sid, u32 did)
{
struct fc_exch *ep;
struct fc_exch *next;
struct fc_exch_mgr *mp = lp->emp;
spin_lock_bh(&mp->em_lock);
restart:
list_for_each_entry_safe(ep, next, &mp->ex_list, ex_list) {
if ((sid == 0 || sid == ep->sid) &&
(did == 0 || did == ep->did)) {
fc_exch_hold(ep);
spin_unlock_bh(&mp->em_lock);
fc_exch_reset(ep);
fc_exch_release(ep);
spin_lock_bh(&mp->em_lock);
/*
* must restart loop incase while lock was down
* multiple eps were released.
*/
goto restart;
}
}
spin_unlock_bh(&mp->em_lock);
}
EXPORT_SYMBOL(fc_exch_mgr_reset);
/*
* Handle incoming ELS REC - Read Exchange Concise.
* Note that the requesting port may be different than the S_ID in the request.
*/
static void fc_exch_els_rec(struct fc_seq *sp, struct fc_frame *rfp)
{
struct fc_frame *fp;
struct fc_exch *ep;
struct fc_exch_mgr *em;
struct fc_els_rec *rp;
struct fc_els_rec_acc *acc;
enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
enum fc_els_rjt_explan explan;
u32 sid;
u16 rxid;
u16 oxid;
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);
/*
* Currently it's hard to find the local S_ID from the exchange
* manager. This will eventually be fixed, but for now it's easier
* to lookup the subject exchange twice, once as if we were
* the initiator, and then again if we weren't.
*/
em = fc_seq_exch(sp)->em;
ep = fc_exch_find(em, oxid);
explan = ELS_EXPL_OXID_RXID;
if (ep && ep->oid == sid) {
if (ep->rxid != FC_XID_UNKNOWN &&
rxid != FC_XID_UNKNOWN &&
ep->rxid != rxid)
goto rel;
} else {
if (ep)
fc_exch_release(ep);
ep = NULL;
if (rxid != FC_XID_UNKNOWN)
ep = fc_exch_find(em, rxid);
if (!ep)
goto reject;
}
fp = fc_frame_alloc(fc_seq_exch(sp)->lp, sizeof(*acc));
if (!fp) {
fc_exch_done(sp);
goto out;
}
sp = fc_seq_start_next(sp);
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));
sp = fc_seq_start_next(sp);
fc_seq_send_last(sp, fp, FC_RCTL_ELS_REP, FC_TYPE_ELS);
out:
fc_exch_release(ep);
fc_frame_free(rfp);
return;
rel:
fc_exch_release(ep);
reject:
fc_seq_ls_rjt(sp, reason, explan);
fc_frame_free(rfp);
}
/*
* Handle response from RRQ.
* Not much to do here, really.
* Should report errors.
*
* 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_DBG("Cannot process RRQ, because of frame error %d\n", err);
return;
}
op = fc_frame_payload_op(fp);
fc_frame_free(fp);
switch (op) {
case ELS_LS_RJT:
FC_DBG("LS_RJT for RRQ");
/* fall through */
case ELS_LS_ACC:
goto cleanup;
default:
FC_DBG("unexpected response op %x for RRQ", op);
return;
}
cleanup:
fc_exch_done(&aborted_ep->seq);
/* drop hold for rec qual */
fc_exch_release(aborted_ep);
}
/*
* Send ELS RRQ - Reinstate Recovery Qualifier.
* 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 *lp;
struct fc_els_rrq *rrq;
struct fc_frame *fp;
struct fc_seq *rrq_sp;
u32 did;
lp = ep->lp;
fp = fc_frame_alloc(lp, sizeof(*rrq));
if (!fp)
return;
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,
fc_host_port_id(lp->host), FC_TYPE_ELS,
FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
rrq_sp = fc_exch_seq_send(lp, fp, fc_exch_rrq_resp, NULL, ep,
lp->e_d_tov);
if (!rrq_sp) {
ep->esb_stat |= ESB_ST_REC_QUAL;
fc_exch_timer_set_locked(ep, ep->r_a_tov);
return;
}
}
/*
* Handle incoming ELS RRQ - Reset Recovery Qualifier.
*/
static void fc_exch_els_rrq(struct fc_seq *sp, struct fc_frame *fp)
{
struct fc_exch *ep; /* request or subject exchange */
struct fc_els_rrq *rp;
u32 sid;
u16 xid;
enum fc_els_rjt_explan explan;
rp = fc_frame_payload_get(fp, sizeof(*rp));
explan = ELS_EXPL_INV_LEN;
if (!rp)
goto reject;
/*
* lookup subject exchange.
*/
ep = fc_seq_exch(sp);
sid = ntoh24(rp->rrq_s_id); /* subject source */
xid = ep->did == sid ? ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
ep = fc_exch_find(ep->em, xid);
explan = ELS_EXPL_OXID_RXID;
if (!ep)
goto reject;
spin_lock_bh(&ep->ex_lock);
if (ep->oxid != ntohs(rp->rrq_ox_id))
goto unlock_reject;
if (ep->rxid != ntohs(rp->rrq_rx_id) &&
ep->rxid != FC_XID_UNKNOWN)
goto unlock_reject;
explan = ELS_EXPL_SID;
if (ep->sid != sid)
goto unlock_reject;
/*
* Clear Recovery Qualifier state, and cancel timer if complete.
*/
if (ep->esb_stat & ESB_ST_REC_QUAL) {
ep->esb_stat &= ~ESB_ST_REC_QUAL;
atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
}
if (ep->esb_stat & ESB_ST_COMPLETE) {
if (cancel_delayed_work(&ep->timeout_work))
atomic_dec(&ep->ex_refcnt); /* drop timer hold */
}
spin_unlock_bh(&ep->ex_lock);
/*
* Send LS_ACC.
*/
fc_seq_ls_acc(sp);
fc_frame_free(fp);
return;
unlock_reject:
spin_unlock_bh(&ep->ex_lock);
fc_exch_release(ep); /* drop hold from fc_exch_find */
reject:
fc_seq_ls_rjt(sp, ELS_RJT_LOGIC, explan);
fc_frame_free(fp);
}
struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lp,
enum fc_class class,
u16 min_xid, u16 max_xid)
{
struct fc_exch_mgr *mp;
size_t len;
if (max_xid <= min_xid || min_xid == 0 || max_xid == FC_XID_UNKNOWN) {
FC_DBG("Invalid min_xid 0x:%x and max_xid 0x:%x\n",
min_xid, max_xid);
return NULL;
}
/*
* Memory need for EM
*/
#define xid_ok(i, m1, m2) (((i) >= (m1)) && ((i) <= (m2)))
len = (max_xid - min_xid + 1) * (sizeof(struct fc_exch *));
len += sizeof(struct fc_exch_mgr);
mp = kzalloc(len, GFP_ATOMIC);
if (!mp)
return NULL;
mp->class = class;
mp->total_exches = 0;
mp->exches = (struct fc_exch **)(mp + 1);
mp->lp = lp;
/* adjust em exch xid range for offload */
mp->min_xid = min_xid;
mp->max_xid = max_xid;
mp->last_xid = min_xid - 1;
mp->max_read = 0;
mp->last_read = 0;
if (lp->lro_enabled && xid_ok(lp->lro_xid, min_xid, max_xid)) {
mp->max_read = lp->lro_xid;
mp->last_read = min_xid - 1;
mp->last_xid = mp->max_read;
} else {
/* disable lro if no xid control over read */
lp->lro_enabled = 0;
}
INIT_LIST_HEAD(&mp->ex_list);
spin_lock_init(&mp->em_lock);
mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
if (!mp->ep_pool)
goto free_mp;
return mp;
free_mp:
kfree(mp);
return NULL;
}
EXPORT_SYMBOL(fc_exch_mgr_alloc);
void fc_exch_mgr_free(struct fc_exch_mgr *mp)
{
WARN_ON(!mp);
/*
* The total exch count must be zero
* before freeing exchange manager.
*/
WARN_ON(mp->total_exches != 0);
mempool_destroy(mp->ep_pool);
kfree(mp);
}
EXPORT_SYMBOL(fc_exch_mgr_free);
struct fc_exch *fc_exch_get(struct fc_lport *lp, struct fc_frame *fp)
{
if (!lp || !lp->emp)
return NULL;
return fc_exch_alloc(lp->emp, fp, 0);
}
EXPORT_SYMBOL(fc_exch_get);
struct fc_seq *fc_exch_seq_send(struct fc_lport *lp,
struct fc_frame *fp,
void (*resp)(struct fc_seq *,
struct fc_frame *fp,
void *arg),
void (*destructor)(struct fc_seq *, void *),
void *arg, u32 timer_msec)
{
struct fc_exch *ep;
struct fc_seq *sp = NULL;
struct fc_frame_header *fh;
int rc = 1;
ep = lp->tt.exch_get(lp, fp);
if (!ep) {
fc_frame_free(fp);
return NULL;
}
ep->esb_stat |= ESB_ST_SEQ_INIT;
fh = fc_frame_header_get(fp);
fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
ep->resp = resp;
ep->destructor = destructor;
ep->arg = arg;
ep->r_a_tov = FC_DEF_R_A_TOV;
ep->lp = lp;
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++;
fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
if (unlikely(lp->tt.frame_send(lp, fp)))
goto err;
if (timer_msec)
fc_exch_timer_set_locked(ep, timer_msec);
ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
if (ep->f_ctl & FC_FC_SEQ_INIT)
ep->esb_stat &= ~ESB_ST_SEQ_INIT;
spin_unlock_bh(&ep->ex_lock);
return sp;
err:
rc = fc_exch_done_locked(ep);
spin_unlock_bh(&ep->ex_lock);
if (!rc)
fc_exch_mgr_delete_ep(ep);
return NULL;
}
EXPORT_SYMBOL(fc_exch_seq_send);
/*
* Receive a frame
*/
void fc_exch_recv(struct fc_lport *lp, struct fc_exch_mgr *mp,
struct fc_frame *fp)
{
struct fc_frame_header *fh = fc_frame_header_get(fp);
u32 f_ctl;
/* lport lock ? */
if (!lp || !mp || (lp->state == LPORT_ST_NONE)) {
FC_DBG("fc_lport or EM is not allocated and configured");
fc_frame_free(fp);
return;
}
/*
* If frame is marked invalid, just drop it.
*/
f_ctl = ntoh24(fh->fh_f_ctl);
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(mp, fp);
else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
FC_FC_EX_CTX)
fc_exch_recv_seq_resp(mp, fp);
else if (f_ctl & FC_FC_SEQ_CTX)
fc_exch_recv_resp(mp, fp);
else
fc_exch_recv_req(lp, mp, fp);
break;
default:
FC_DBG("dropping invalid frame (eof %x)", fr_eof(fp));
fc_frame_free(fp);
break;
}
}
EXPORT_SYMBOL(fc_exch_recv);
int fc_exch_init(struct fc_lport *lp)
{
if (!lp->tt.exch_get) {
/*
* exch_put() should be NULL if
* exch_get() is NULL
*/
WARN_ON(lp->tt.exch_put);
lp->tt.exch_get = fc_exch_get;
}
if (!lp->tt.seq_start_next)
lp->tt.seq_start_next = fc_seq_start_next;
if (!lp->tt.exch_seq_send)
lp->tt.exch_seq_send = fc_exch_seq_send;
if (!lp->tt.seq_send)
lp->tt.seq_send = fc_seq_send;
if (!lp->tt.seq_els_rsp_send)
lp->tt.seq_els_rsp_send = fc_seq_els_rsp_send;
if (!lp->tt.exch_done)
lp->tt.exch_done = fc_exch_done;
if (!lp->tt.exch_mgr_reset)
lp->tt.exch_mgr_reset = fc_exch_mgr_reset;
if (!lp->tt.seq_exch_abort)
lp->tt.seq_exch_abort = fc_seq_exch_abort;
return 0;
}
EXPORT_SYMBOL(fc_exch_init);
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;
return 0;
}
void fc_destroy_exch_mgr(void)
{
kmem_cache_destroy(fc_em_cachep);
}
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