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linux/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/slab.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/log2.h>
#include <scsi/fc/fc_fc2.h>
#include <scsi/libfc.h>
#include <scsi/fc_encode.h>
#include "fc_libfc.h"
u16 fc_cpu_mask; /* cpu mask for possible cpus */
EXPORT_SYMBOL(fc_cpu_mask);
static u16 fc_cpu_order; /* 2's power to represent total possible cpus */
static struct kmem_cache *fc_em_cachep; /* cache for exchanges */
static struct workqueue_struct *fc_exch_workqueue;
/*
* Structure and function definitions for managing Fibre Channel Exchanges
* and Sequences.
*
* The three primary structures used here are fc_exch_mgr, fc_exch, and fc_seq.
*
* fc_exch_mgr holds the exchange state for an N port
*
* fc_exch holds state for one exchange and links to its active sequence.
*
* fc_seq holds the state for an individual sequence.
*/
/**
* struct fc_exch_pool - Per cpu exchange pool
* @next_index: Next possible free exchange index
* @total_exches: Total allocated exchanges
* @lock: Exch pool lock
* @ex_list: List of exchanges
*
* This structure manages per cpu exchanges in array of exchange pointers.
* This array is allocated followed by struct fc_exch_pool memory for
* assigned range of exchanges to per cpu pool.
*/
struct fc_exch_pool {
spinlock_t lock;
struct list_head ex_list;
u16 next_index;
u16 total_exches;
/* two cache of free slot in exch array */
u16 left;
u16 right;
} ____cacheline_aligned_in_smp;
/**
* struct fc_exch_mgr - The Exchange Manager (EM).
* @class: Default class for new sequences
* @kref: Reference counter
* @min_xid: Minimum exchange ID
* @max_xid: Maximum exchange ID
* @ep_pool: Reserved exchange pointers
* @pool_max_index: Max exch array index in exch pool
* @pool: Per cpu exch pool
* @stats: Statistics structure
*
* This structure is the center for creating exchanges and sequences.
* It manages the allocation of exchange IDs.
*/
struct fc_exch_mgr {
struct fc_exch_pool __percpu *pool;
mempool_t *ep_pool;
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_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;
}
/**
* fc_exch_ptr_get() - Return an exchange from an exchange pool
* @pool: Exchange Pool to get an exchange from
* @index: Index of the exchange within the pool
*
* Use the index to get an exchange from within an exchange pool. exches
* will point to an array of exchange pointers. The index will select
* the exchange within the array.
*/
static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,
u16 index)
{
struct fc_exch **exches = (struct fc_exch **)(pool + 1);
return exches[index];
}
/**
* fc_exch_ptr_set() - Assign an exchange to a slot in an exchange pool
* @pool: The pool to assign the exchange to
* @index: The index in the pool where the exchange will be assigned
* @ep: The exchange to assign to the pool
*/
static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
struct fc_exch *ep)
{
((struct fc_exch **)(pool + 1))[index] = ep;
}
/**
* fc_exch_delete() - Delete an exchange
* @ep: The exchange to be deleted
*/
static void fc_exch_delete(struct fc_exch *ep)
{
struct fc_exch_pool *pool;
u16 index;
pool = ep->pool;
spin_lock_bh(&pool->lock);
WARN_ON(pool->total_exches <= 0);
pool->total_exches--;
/* update cache of free slot */
index = (ep->xid - ep->em->min_xid) >> fc_cpu_order;
if (pool->left == FC_XID_UNKNOWN)
pool->left = index;
else if (pool->right == FC_XID_UNKNOWN)
pool->right = index;
else
pool->next_index = index;
fc_exch_ptr_set(pool, index, NULL);
list_del(&ep->ex_list);
spin_unlock_bh(&pool->lock);
fc_exch_release(ep); /* drop hold for exch in mp */
}
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().
*/
static 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;
}
/**
* fc_seq_alloc() - Allocate a sequence for a given exchange
* @ep: The exchange to allocate a new sequence for
* @seq_id: The sequence ID to be used
*
* We don't support multiple originated sequences on the same exchange.
* By implication, any previously originated sequence on this exchange
* is complete, and we reallocate the same sequence.
*/
static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
{
struct fc_seq *sp;
sp = &ep->seq;
sp->ssb_stat = 0;
sp->cnt = 0;
sp->id = seq_id;
return sp;
}
/**
* fc_seq_start_next_locked() - Allocate a new sequence on the same
* exchange as the supplied sequence
* @sp: The sequence/exchange to get a new sequence for
*/
static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
{
struct fc_exch *ep = fc_seq_exch(sp);
sp = fc_seq_alloc(ep, ep->seq_id++);
FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
ep->f_ctl, sp->id);
return sp;
}
/**
* fc_seq_start_next() - Lock the exchange and get a new sequence
* for a given sequence/exchange pair
* @sp: The sequence/exchange to get a new exchange for
*/
static struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
{
struct fc_exch *ep = fc_seq_exch(sp);
spin_lock_bh(&ep->ex_lock);
sp = fc_seq_start_next_locked(sp);
spin_unlock_bh(&ep->ex_lock);
return sp;
}
/*
* Set the response handler for the exchange associated with a sequence.
*
* Note: May sleep if invoked from outside a response handler.
*/
static void fc_seq_set_resp(struct fc_seq *sp,
void (*resp)(struct fc_seq *, struct fc_frame *,
void *),
void *arg)
{
struct fc_exch *ep = fc_seq_exch(sp);
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);
}
/**
* fc_exch_abort_locked() - Abort an exchange
* @ep: The exchange to be aborted
* @timer_msec: The period of time to wait before aborting
*
* 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;
if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP))
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
*/
static int fc_seq_exch_abort(const struct fc_seq *req_sp,
unsigned int timer_msec)
{
struct fc_exch *ep;
int error;
ep = fc_seq_exch(req_sp);
spin_lock_bh(&ep->ex_lock);
error = fc_exch_abort_locked(ep, timer_msec);
spin_unlock_bh(&ep->ex_lock);
return error;
}
/**
* fc_invoke_resp() - invoke ep->resp()
*
* Notes:
* It is assumed that after initialization finished (this means the
* first unlock of ex_lock after fc_exch_alloc()) ep->resp and ep->arg are
* modified only via fc_seq_set_resp(). This guarantees that none of these
* two variables changes if ep->resp_active > 0.
*
* If an fc_seq_set_resp() call is busy modifying ep->resp and ep->arg when
* this function is invoked, the first spin_lock_bh() call in this function
* will wait until fc_seq_set_resp() has finished modifying these variables.
*
* Since fc_exch_done() invokes fc_seq_set_resp() it is guaranteed that that
* ep->resp() won't be invoked after fc_exch_done() has returned.
*
* The response handler itself may invoke fc_exch_done(), which will clear the
* ep->resp pointer.
*
* Return value:
* Returns true if and only if ep->resp has been invoked.
*/
static bool fc_invoke_resp(struct fc_exch *ep, struct fc_seq *sp,
struct fc_frame *fp)
{
void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
void *arg;
bool res = false;
spin_lock_bh(&ep->ex_lock);
ep->resp_active++;
if (ep->resp_task != current)
ep->resp_task = !ep->resp_task ? current : NULL;
resp = ep->resp;
arg = ep->arg;
spin_unlock_bh(&ep->ex_lock);
if (resp) {
resp(sp, fp, arg);
res = true;
} else if (!IS_ERR(fp)) {
fc_frame_free(fp);
}
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\n");
spin_lock_bh(&ep->ex_lock);
if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
goto unlock;
e_stat = ep->esb_stat;
if (e_stat & ESB_ST_COMPLETE) {
ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
spin_unlock_bh(&ep->ex_lock);
if (e_stat & ESB_ST_REC_QUAL)
fc_exch_rrq(ep);
goto done;
} else {
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) {
index = pool->left;
pool->left = FC_XID_UNKNOWN;
goto hit;
}
if (pool->right != FC_XID_UNKNOWN) {
index = pool->right;
pool->right = FC_XID_UNKNOWN;
goto hit;
}
index = pool->next_index;
/* allocate new exch from pool */
while (fc_exch_ptr_get(pool, index)) {
index = index == mp->pool_max_index ? 0 : index + 1;
if (index == pool->next_index)
goto err;
}
pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
hit:
fc_exch_hold(ep); /* hold for exch in mp */
spin_lock_init(&ep->ex_lock);
/*
* Hold exch lock for caller to prevent fc_exch_reset()
* from releasing exch while fc_exch_alloc() caller is
* still working on exch.
*/
spin_lock_bh(&ep->ex_lock);
fc_exch_ptr_set(pool, index, ep);
list_add_tail(&ep->ex_list, &pool->ex_list);
fc_seq_alloc(ep, ep->seq_id++);
pool->total_exches++;
spin_unlock_bh(&pool->lock);
/*
* update exchange
*/
ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
ep->em = mp;
ep->pool = pool;
ep->lp = lport;
ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
ep->rxid = FC_XID_UNKNOWN;
ep->class = mp->class;
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 inline struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
struct fc_frame *fp)
{
struct fc_exch_mgr_anchor *ema;
list_for_each_entry(ema, &lport->ema_list, ema_list)
if (!ema->match || ema->match(fp))
return fc_exch_em_alloc(lport, ema->mp);
return NULL;
}
/**
* fc_exch_find() - Lookup and hold an exchange
* @mp: The exchange manager to lookup the exchange from
* @xid: The XID of the exchange to look up
*/
static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
{
struct fc_exch_pool *pool;
struct fc_exch *ep = NULL;
if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
pool = per_cpu_ptr(mp->pool, xid & fc_cpu_mask);
spin_lock_bh(&pool->lock);
ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
if (ep) {
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.
*/
static void fc_exch_done(struct fc_seq *sp)
{
struct fc_exch *ep = fc_seq_exch(sp);
int rc;
spin_lock_bh(&ep->ex_lock);
rc = fc_exch_done_locked(ep);
spin_unlock_bh(&ep->ex_lock);
fc_seq_set_resp(sp, NULL, ep->arg);
if (!rc)
fc_exch_delete(ep);
}
/**
* fc_exch_resp() - Allocate a new exchange for a response frame
* @lport: The local port that the exchange was for
* @mp: The exchange manager to allocate the exchange from
* @fp: The response frame
*
* Sets the responder ID in the frame header.
*/
static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
struct fc_exch_mgr *mp,
struct fc_frame *fp)
{
struct fc_exch *ep;
struct fc_frame_header *fh;
ep = fc_exch_alloc(lport, fp);
if (ep) {
ep->class = fc_frame_class(fp);
/*
* Set EX_CTX indicating we're responding on this exchange.
*/
ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
fh = fc_frame_header_get(fp);
ep->sid = ntoh24(fh->fh_d_id);
ep->did = ntoh24(fh->fh_s_id);
ep->oid = ep->did;
/*
* Allocated exchange has placed the XID in the
* originator field. Move it to the responder field,
* and set the originator XID from the frame.
*/
ep->rxid = ep->xid;
ep->oxid = ntohs(fh->fh_ox_id);
ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
ep->esb_stat &= ~ESB_ST_SEQ_INIT;
fc_exch_hold(ep); /* hold for caller */
spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
}
return ep;
}
/**
* fc_seq_lookup_recip() - Find a sequence where the other end
* originated the sequence
* @lport: The local port that the frame was sent to
* @mp: The Exchange Manager to lookup the exchange from
* @fp: The frame associated with the sequence we're looking for
*
* If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
* on the ep that should be released by the caller.
*/
static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
struct fc_exch_mgr *mp,
struct fc_frame *fp)
{
struct fc_frame_header *fh = fc_frame_header_get(fp);
struct fc_exch *ep = NULL;
struct fc_seq *sp = NULL;
enum fc_pf_rjt_reason reject = FC_RJT_NONE;
u32 f_ctl;
u16 xid;
f_ctl = ntoh24(fh->fh_f_ctl);
WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
/*
* Lookup or create the exchange if we will be creating the sequence.
*/
if (f_ctl & FC_FC_EX_CTX) {
xid = ntohs(fh->fh_ox_id); /* we originated exch */
ep = fc_exch_find(mp, xid);
if (!ep) {
atomic_inc(&mp->stats.xid_not_found);
reject = FC_RJT_OX_ID;
goto out;
}
if (ep->rxid == FC_XID_UNKNOWN)
ep->rxid = ntohs(fh->fh_rx_id);
else if (ep->rxid != ntohs(fh->fh_rx_id)) {
reject = FC_RJT_OX_ID;
goto rel;
}
} else {
xid = ntohs(fh->fh_rx_id); /* we are the responder */
/*
* Special case for MDS issuing an ELS TEST with a
* bad rxid of 0.
* XXX take this out once we do the proper reject.
*/
if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
fc_frame_payload_op(fp) == ELS_TEST) {
fh->fh_rx_id = htons(FC_XID_UNKNOWN);
xid = FC_XID_UNKNOWN;
}
/*
* new sequence - find the exchange
*/
ep = fc_exch_find(mp, xid);
if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
if (ep) {
atomic_inc(&mp->stats.xid_busy);
reject = FC_RJT_RX_ID;
goto rel;
}
ep = fc_exch_resp(lport, mp, fp);
if (!ep) {
reject = FC_RJT_EXCH_EST; /* XXX */
goto out;
}
xid = ep->xid; /* get our XID */
} else if (!ep) {
atomic_inc(&mp->stats.xid_not_found);
reject = FC_RJT_RX_ID; /* XID not found */
goto out;
}
}
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.
*/
static void fc_seq_els_rsp_send(struct fc_frame *fp, enum fc_els_cmd els_cmd,
struct fc_seq_els_data *els_data)
{
switch (els_cmd) {
case ELS_LS_RJT:
fc_seq_ls_rjt(fp, els_data->reason, els_data->explan);
break;
case ELS_LS_ACC:
fc_seq_ls_acc(fp);
break;
case ELS_RRQ:
fc_exch_els_rrq(fp);
break;
case ELS_REC:
fc_exch_els_rec(fp);
break;
default:
FC_LPORT_DBG(fr_dev(fp), "Invalid ELS CMD:%x\n", els_cmd);
}
}
/**
* fc_seq_send_last() - Send a sequence that is the last in the exchange
* @sp: The sequence that is to be sent
* @fp: The frame that will be sent on the sequence
* @rctl: The R_CTL information to be sent
* @fh_type: The frame header type
*/
static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
enum fc_rctl rctl, enum fc_fh_type fh_type)
{
u32 f_ctl;
struct fc_exch *ep = fc_seq_exch(sp);
f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
f_ctl |= ep->f_ctl;
fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
fc_seq_send_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)
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_lport *lport;
unsigned int f_ctl;
lport = fr_dev(rx_fp);
fp = fc_frame_alloc(lport, sizeof(*rp));
if (!fp)
return;
fh = fc_frame_header_get(fp);
rx_fh = fc_frame_header_get(rx_fp);
memset(fh, 0, sizeof(*fh) + sizeof(*rp));
rp = fc_frame_payload_get(fp, sizeof(*rp));
rp->br_reason = reason;
rp->br_explan = explan;
/*
* seq_id, cs_ctl, df_ctl and param/offset are zero.
*/
memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
fh->fh_ox_id = rx_fh->fh_ox_id;
fh->fh_rx_id = rx_fh->fh_rx_id;
fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
fh->fh_r_ctl = FC_RCTL_BA_RJT;
fh->fh_type = FC_TYPE_BLS;
/*
* Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
* Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
* Bits 9-8 are meaningful (retransmitted or unidirectional).
* Last ACK uses bits 7-6 (continue sequence),
* bits 5-4 are meaningful (what kind of ACK to use).
* Always set LAST_SEQ, END_SEQ.
*/
f_ctl = ntoh24(rx_fh->fh_f_ctl);
f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
FC_FC_END_CONN | FC_FC_SEQ_INIT |
FC_FC_RETX_SEQ | FC_FC_UNI_TX;
f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
f_ctl &= ~FC_FC_FIRST_SEQ;
hton24(fh->fh_f_ctl, f_ctl);
fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
fr_eof(fp) = FC_EOF_T;
if (fc_sof_needs_ack(fr_sof(fp)))
fr_eof(fp) = FC_EOF_N;
lport->tt.frame_send(lport, fp);
}
/**
* fc_exch_recv_abts() - Handle an incoming ABTS
* @ep: The exchange the abort was on
* @rx_fp: The ABTS frame
*
* This would be for target mode usually, but could be due to lost
* FCP transfer ready, confirm or RRQ. We always handle this as an
* exchange abort, ignoring the parameter.
*/
static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
{
struct fc_frame *fp;
struct fc_ba_acc *ap;
struct fc_frame_header *fh;
struct fc_seq *sp;
if (!ep)
goto reject;
fp = fc_frame_alloc(ep->lp, sizeof(*ap));
if (!fp)
goto free;
spin_lock_bh(&ep->ex_lock);
if (ep->esb_stat & ESB_ST_COMPLETE) {
spin_unlock_bh(&ep->ex_lock);
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().
*/
static struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)
{
struct fc_exch_mgr_anchor *ema;
WARN_ON(lport != fr_dev(fp));
WARN_ON(fr_seq(fp));
fr_seq(fp) = NULL;
list_for_each_entry(ema, &lport->ema_list, ema_list)
if ((!ema->match || ema->match(fp)) &&
fc_seq_lookup_recip(lport, ema->mp, fp) == FC_RJT_NONE)
break;
return fr_seq(fp);
}
/**
* fc_seq_release() - Release the hold
* @sp: The sequence.
*/
static void fc_seq_release(struct fc_seq *sp)
{
fc_exch_release(fc_seq_exch(sp));
}
/**
* fc_exch_recv_req() - Handler for an incoming request
* @lport: The local port that received the request
* @mp: The EM that the exchange is on
* @fp: The request frame
*
* This is used when the other end is originating the exchange
* and the sequence.
*/
static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp,
struct fc_frame *fp)
{
struct fc_frame_header *fh = fc_frame_header_get(fp);
struct fc_seq *sp = NULL;
struct fc_exch *ep = NULL;
enum fc_pf_rjt_reason reject;
/* We can have the wrong fc_lport at this point with NPIV, which is a
* problem now that we know a new exchange needs to be allocated
*/
lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id));
if (!lport) {
fc_frame_free(fp);
return;
}
fr_dev(fp) = lport;
BUG_ON(fr_seq(fp)); /* XXX remove later */
/*
* If the RX_ID is 0xffff, don't allocate an exchange.
* The upper-level protocol may request one later, if needed.
*/
if (fh->fh_rx_id == htons(FC_XID_UNKNOWN))
return lport->tt.lport_recv(lport, fp);
reject = fc_seq_lookup_recip(lport, mp, fp);
if (reject == FC_RJT_NONE) {
sp = fr_seq(fp); /* sequence will be held */
ep = fc_seq_exch(sp);
fc_seq_send_ack(sp, fp);
ep->encaps = fr_encaps(fp);
/*
* Call the receive function.
*
* The receive function may allocate a new sequence
* over the old one, so we shouldn't change the
* sequence after this.
*
* The frame will be freed by the receive function.
* If new exch resp handler is valid then call that
* first.
*/
if (!fc_invoke_resp(ep, sp, fp))
lport->tt.lport_recv(lport, fp);
fc_exch_release(ep); /* release from lookup */
} else {
FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n",
reject);
fc_frame_free(fp);
}
}
/**
* fc_exch_recv_seq_resp() - Handler for an incoming response where the other
* end is the originator of the sequence that is a
* response to our initial exchange
* @mp: The EM that the exchange is on
* @fp: The response frame
*/
static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
{
struct fc_frame_header *fh = fc_frame_header_get(fp);
struct fc_seq *sp;
struct fc_exch *ep;
enum fc_sof sof;
u32 f_ctl;
int rc;
ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
if (!ep) {
atomic_inc(&mp->stats.xid_not_found);
goto out;
}
if (ep->esb_stat & ESB_ST_COMPLETE) {
atomic_inc(&mp->stats.xid_not_found);
goto rel;
}
if (ep->rxid == FC_XID_UNKNOWN)
ep->rxid = ntohs(fh->fh_rx_id);
if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
atomic_inc(&mp->stats.xid_not_found);
goto rel;
}
if (ep->did != ntoh24(fh->fh_s_id) &&
ep->did != FC_FID_FLOGI) {
atomic_inc(&mp->stats.xid_not_found);
goto rel;
}
sof = fr_sof(fp);
sp = &ep->seq;
if (fc_sof_is_init(sof)) {
sp->ssb_stat |= SSB_ST_RESP;
sp->id = fh->fh_seq_id;
} else if (sp->id != fh->fh_seq_id) {
atomic_inc(&mp->stats.seq_not_found);
goto rel;
}
f_ctl = ntoh24(fh->fh_f_ctl);
fr_seq(fp) = sp;
spin_lock_bh(&ep->ex_lock);
if (f_ctl & FC_FC_SEQ_INIT)
ep->esb_stat |= ESB_ST_SEQ_INIT;
spin_unlock_bh(&ep->ex_lock);
if (fc_sof_needs_ack(sof))
fc_seq_send_ack(sp, fp);
if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
(f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
(FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
spin_lock_bh(&ep->ex_lock);
rc = fc_exch_done_locked(ep);
WARN_ON(fc_seq_exch(sp) != ep);
spin_unlock_bh(&ep->ex_lock);
if (!rc)
fc_exch_delete(ep);
}
/*
* Call the receive function.
* The sequence is held (has a refcnt) for us,
* but not for the receive function.
*
* The receive function may allocate a new sequence
* over the old one, so we shouldn't change the
* sequence after this.
*
* The frame will be freed by the receive function.
* If new exch resp handler is valid then call that
* first.
*/
fc_invoke_resp(ep, sp, fp);
fc_exch_release(ep);
return;
rel:
fc_exch_release(ep);
out:
fc_frame_free(fp);
}
/**
* fc_exch_recv_resp() - Handler for a sequence where other end is
* responding to our sequence
* @mp: The EM that the exchange is on
* @fp: The response frame
*/
static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
{
struct fc_seq *sp;
sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
if (!sp)
atomic_inc(&mp->stats.xid_not_found);
else
atomic_inc(&mp->stats.non_bls_resp);
fc_frame_free(fp);
}
/**
* fc_exch_abts_resp() - Handler for a response to an ABT
* @ep: The exchange that the frame is on
* @fp: The response frame
*
* This response would be to an ABTS cancelling an exchange or sequence.
* The response can be either BA_ACC or BA_RJT
*/
static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
{
struct fc_frame_header *fh;
struct fc_ba_acc *ap;
struct fc_seq *sp;
u16 low;
u16 high;
int rc = 1, has_rec = 0;
fh = fc_frame_header_get(fp);
FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
fc_exch_rctl_name(fh->fh_r_ctl));
if (cancel_delayed_work_sync(&ep->timeout_work)) {
FC_EXCH_DBG(ep, "Exchange timer canceled due to ABTS response\n");
fc_exch_release(ep); /* release from pending timer hold */
}
spin_lock_bh(&ep->ex_lock);
switch (fh->fh_r_ctl) {
case FC_RCTL_BA_ACC:
ap = fc_frame_payload_get(fp, sizeof(*ap));
if (!ap)
break;
/*
* Decide whether to establish a Recovery Qualifier.
* We do this if there is a non-empty SEQ_CNT range and
* SEQ_ID is the same as the one we aborted.
*/
low = ntohs(ap->ba_low_seq_cnt);
high = ntohs(ap->ba_high_seq_cnt);
if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
(ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
ap->ba_seq_id == ep->seq_id) && low != high) {
ep->esb_stat |= ESB_ST_REC_QUAL;
fc_exch_hold(ep); /* hold for recovery qualifier */
has_rec = 1;
}
break;
case FC_RCTL_BA_RJT:
break;
default:
break;
}
/* do we need to do some other checks here. Can we reuse more of
* fc_exch_recv_seq_resp
*/
sp = &ep->seq;
/*
* do we want to check END_SEQ as well as LAST_SEQ here?
*/
if (ep->fh_type != FC_TYPE_FCP &&
ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
rc = fc_exch_done_locked(ep);
spin_unlock_bh(&ep->ex_lock);
fc_exch_hold(ep);
if (!rc)
fc_exch_delete(ep);
fc_invoke_resp(ep, sp, 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:
fc_exch_recv_abts(ep, fp);
break;
default: /* ignore junk */
fc_frame_free(fp);
break;
}
}
if (ep)
fc_exch_release(ep); /* release hold taken by fc_exch_find */
}
/**
* fc_seq_ls_acc() - Accept sequence with LS_ACC
* @rx_fp: The received frame, not freed here.
*
* If this fails due to allocation or transmit congestion, assume the
* originator will repeat the sequence.
*/
static void fc_seq_ls_acc(struct fc_frame *rx_fp)
{
struct fc_lport *lport;
struct fc_els_ls_acc *acc;
struct fc_frame *fp;
lport = fr_dev(rx_fp);
fp = fc_frame_alloc(lport, sizeof(*acc));
if (!fp)
return;
acc = fc_frame_payload_get(fp, sizeof(*acc));
memset(acc, 0, sizeof(*acc));
acc->la_cmd = ELS_LS_ACC;
fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
lport->tt.frame_send(lport, fp);
}
/**
* fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT
* @rx_fp: The received frame, not freed here.
* @reason: The reason the sequence is being rejected
* @explan: The explanation for the rejection
*
* If this fails due to allocation or transmit congestion, assume the
* originator will repeat the sequence.
*/
static void fc_seq_ls_rjt(struct fc_frame *rx_fp, enum fc_els_rjt_reason reason,
enum fc_els_rjt_explan explan)
{
struct fc_lport *lport;
struct fc_els_ls_rjt *rjt;
struct fc_frame *fp;
lport = fr_dev(rx_fp);
fp = fc_frame_alloc(lport, sizeof(*rjt));
if (!fp)
return;
rjt = fc_frame_payload_get(fp, sizeof(*rjt));
memset(rjt, 0, sizeof(*rjt));
rjt->er_cmd = ELS_LS_RJT;
rjt->er_reason = reason;
rjt->er_explan = explan;
fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
lport->tt.frame_send(lport, fp);
}
/**
* fc_exch_reset() - Reset an exchange
* @ep: The exchange to be reset
*
* 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);
fc_exch_abort_locked(ep, 0);
ep->state |= FC_EX_RST_CLEANUP;
fc_exch_timer_cancel(ep);
if (ep->esb_stat & ESB_ST_REC_QUAL)
atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
ep->esb_stat &= ~ESB_ST_REC_QUAL;
sp = &ep->seq;
rc = fc_exch_done_locked(ep);
spin_unlock_bh(&ep->ex_lock);
fc_exch_hold(ep);
if (!rc)
fc_exch_delete(ep);
fc_invoke_resp(ep, sp, ERR_PTR(-FC_EX_CLOSED));
fc_seq_set_resp(sp, NULL, ep->arg);
fc_exch_release(ep);
}
/**
* fc_exch_pool_reset() - Reset a per cpu exchange pool
* @lport: The local port that the exchange pool is on
* @pool: The exchange pool to be reset
* @sid: The source ID
* @did: The destination ID
*
* Resets a per cpu exches pool, releasing all of its sequences
* and exchanges. If sid is non-zero then reset only exchanges
* we sourced from the local port's FID. If did is non-zero then
* only reset exchanges destined for the local port's FID.
*/
static void fc_exch_pool_reset(struct fc_lport *lport,
struct fc_exch_pool *pool,
u32 sid, u32 did)
{
struct fc_exch *ep;
struct fc_exch *next;
spin_lock_bh(&pool->lock);
restart:
list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
if ((lport == ep->lp) &&
(sid == 0 || sid == ep->sid) &&
(did == 0 || did == ep->did)) {
fc_exch_hold(ep);
spin_unlock_bh(&pool->lock);
fc_exch_reset(ep);
fc_exch_release(ep);
spin_lock_bh(&pool->lock);
/*
* must restart loop incase while lock
* was down multiple eps were released.
*/
goto restart;
}
}
pool->next_index = 0;
pool->left = FC_XID_UNKNOWN;
pool->right = FC_XID_UNKNOWN;
spin_unlock_bh(&pool->lock);
}
/**
* fc_exch_mgr_reset() - Reset all EMs of a local port
* @lport: The local port whose EMs are to be reset
* @sid: The source ID
* @did: The destination ID
*
* Reset all EMs associated with a given local port. Release all
* sequences and exchanges. If sid is non-zero then reset only the
* exchanges sent from the local port's FID. If did is non-zero then
* reset only exchanges destined for the local port's FID.
*/
void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
{
struct fc_exch_mgr_anchor *ema;
unsigned int cpu;
list_for_each_entry(ema, &lport->ema_list, ema_list) {
for_each_possible_cpu(cpu)
fc_exch_pool_reset(lport,
per_cpu_ptr(ema->mp->pool, cpu),
sid, did);
}
}
EXPORT_SYMBOL(fc_exch_mgr_reset);
/**
* fc_exch_lookup() - find an exchange
* @lport: The local port
* @xid: The exchange ID
*
* Returns exchange pointer with hold for caller, or NULL if not found.
*/
static struct fc_exch *fc_exch_lookup(struct fc_lport *lport, u32 xid)
{
struct fc_exch_mgr_anchor *ema;
list_for_each_entry(ema, &lport->ema_list, ema_list)
if (ema->mp->min_xid <= xid && xid <= ema->mp->max_xid)
return fc_exch_find(ema->mp, xid);
return NULL;
}
/**
* fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests
* @rfp: The REC frame, not freed here.
*
* Note that the requesting port may be different than the S_ID in the request.
*/
static void fc_exch_els_rec(struct fc_frame *rfp)
{
struct fc_lport *lport;
struct fc_frame *fp;
struct fc_exch *ep;
struct fc_els_rec *rp;
struct fc_els_rec_acc *acc;
enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
enum fc_els_rjt_explan explan;
u32 sid;
u16 rxid;
u16 oxid;
lport = fr_dev(rfp);
rp = fc_frame_payload_get(rfp, sizeof(*rp));
explan = ELS_EXPL_INV_LEN;
if (!rp)
goto reject;
sid = ntoh24(rp->rec_s_id);
rxid = ntohs(rp->rec_rx_id);
oxid = ntohs(rp->rec_ox_id);
ep = fc_exch_lookup(lport,
sid == fc_host_port_id(lport->host) ? oxid : rxid);
explan = ELS_EXPL_OXID_RXID;
if (!ep)
goto reject;
if (ep->oid != sid || oxid != ep->oxid)
goto rel;
if (rxid != FC_XID_UNKNOWN && rxid != ep->rxid)
goto rel;
fp = fc_frame_alloc(lport, sizeof(*acc));
if (!fp)
goto out;
acc = fc_frame_payload_get(fp, sizeof(*acc));
memset(acc, 0, sizeof(*acc));
acc->reca_cmd = ELS_LS_ACC;
acc->reca_ox_id = rp->rec_ox_id;
memcpy(acc->reca_ofid, rp->rec_s_id, 3);
acc->reca_rx_id = htons(ep->rxid);
if (ep->sid == ep->oid)
hton24(acc->reca_rfid, ep->did);
else
hton24(acc->reca_rfid, ep->sid);
acc->reca_fc4value = htonl(ep->seq.rec_data);
acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
ESB_ST_SEQ_INIT |
ESB_ST_COMPLETE));
fc_fill_reply_hdr(fp, rfp, FC_RCTL_ELS_REP, 0);
lport->tt.frame_send(lport, fp);
out:
fc_exch_release(ep);
return;
rel:
fc_exch_release(ep);
reject:
fc_seq_ls_rjt(rfp, reason, explan);
}
/**
* fc_exch_rrq_resp() - Handler for RRQ responses
* @sp: The sequence that the RRQ is on
* @fp: The RRQ frame
* @arg: The exchange that the RRQ is on
*
* TODO: fix error handler.
*/
static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
{
struct fc_exch *aborted_ep = arg;
unsigned int op;
if (IS_ERR(fp)) {
int err = PTR_ERR(fp);
if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
goto cleanup;
FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
"frame error %d\n", err);
return;
}
op = fc_frame_payload_op(fp);
fc_frame_free(fp);
switch (op) {
case ELS_LS_RJT:
FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ\n");
/* fall through */
case ELS_LS_ACC:
goto cleanup;
default:
FC_EXCH_DBG(aborted_ep, "unexpected response op %x for RRQ\n",
op);
return;
}
cleanup:
fc_exch_done(&aborted_ep->seq);
/* drop hold for rec qual */
fc_exch_release(aborted_ep);
}
/**
* fc_exch_seq_send() - Send a frame using a new exchange and sequence
* @lport: The local port to send the frame on
* @fp: The frame to be sent
* @resp: The response handler for this request
* @destructor: The destructor for the exchange
* @arg: The argument to be passed to the response handler
* @timer_msec: The timeout period for the exchange
*
* The frame pointer with some of the header's fields must be
* filled before calling this routine, those fields are:
*
* - routing control
* - FC port did
* - FC port sid
* - FC header type
* - frame control
* - parameter or relative offset
*/
static struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
struct fc_frame *fp,
void (*resp)(struct fc_seq *,
struct fc_frame *fp,
void *arg),
void (*destructor)(struct fc_seq *,
void *),
void *arg, u32 timer_msec)
{
struct fc_exch *ep;
struct fc_seq *sp = NULL;
struct fc_frame_header *fh;
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 = FC_DEF_R_A_TOV;
ep->lp = lport;
sp = &ep->seq;
ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
ep->f_ctl = ntoh24(fh->fh_f_ctl);
fc_exch_setup_hdr(ep, fp, ep->f_ctl);
sp->cnt++;
if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD) {
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;
}
/**
* fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command
* @ep: The exchange to send the RRQ on
*
* This tells the remote port to stop blocking the use of
* the exchange and the seq_cnt range.
*/
static void fc_exch_rrq(struct fc_exch *ep)
{
struct fc_lport *lport;
struct fc_els_rrq *rrq;
struct fc_frame *fp;
u32 did;
lport = ep->lp;
fp = fc_frame_alloc(lport, sizeof(*rrq));
if (!fp)
goto retry;
rrq = fc_frame_payload_get(fp, sizeof(*rrq));
memset(rrq, 0, sizeof(*rrq));
rrq->rrq_cmd = ELS_RRQ;
hton24(rrq->rrq_s_id, ep->sid);
rrq->rrq_ox_id = htons(ep->oxid);
rrq->rrq_rx_id = htons(ep->rxid);
did = ep->did;
if (ep->esb_stat & ESB_ST_RESP)
did = ep->sid;
fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
lport->port_id, FC_TYPE_ELS,
FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep,
lport->e_d_tov))
return;
retry:
spin_lock_bh(&ep->ex_lock);
if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
spin_unlock_bh(&ep->ex_lock);
/* drop hold for rec qual */
fc_exch_release(ep);
return;
}
ep->esb_stat |= ESB_ST_REC_QUAL;
fc_exch_timer_set_locked(ep, ep->r_a_tov);
spin_unlock_bh(&ep->ex_lock);
}
/**
* fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests
* @fp: The RRQ frame, not freed here.
*/
static void fc_exch_els_rrq(struct fc_frame *fp)
{
struct fc_lport *lport;
struct fc_exch *ep = NULL; /* request or subject exchange */
struct fc_els_rrq *rp;
u32 sid;
u16 xid;
enum fc_els_rjt_explan explan;
lport = fr_dev(fp);
rp = fc_frame_payload_get(fp, sizeof(*rp));
explan = ELS_EXPL_INV_LEN;
if (!rp)
goto reject;
/*
* lookup subject exchange.
*/
sid = ntoh24(rp->rrq_s_id); /* subject source */
xid = fc_host_port_id(lport->host) == sid ?
ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
ep = fc_exch_lookup(lport, xid);
explan = ELS_EXPL_OXID_RXID;
if (!ep)
goto reject;
spin_lock_bh(&ep->ex_lock);
if (ep->oxid != ntohs(rp->rrq_ox_id))
goto unlock_reject;
if (ep->rxid != ntohs(rp->rrq_rx_id) &&
ep->rxid != FC_XID_UNKNOWN)
goto unlock_reject;
explan = ELS_EXPL_SID;
if (ep->sid != sid)
goto unlock_reject;
/*
* Clear Recovery Qualifier state, and cancel timer if complete.
*/
if (ep->esb_stat & ESB_ST_REC_QUAL) {
ep->esb_stat &= ~ESB_ST_REC_QUAL;
atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
}
if (ep->esb_stat & ESB_ST_COMPLETE)
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;
/* adjust em exch xid range for offload */
mp->min_xid = min_xid;
/* reduce range so per cpu pool fits into PCPU_MIN_UNIT_SIZE pool */
pool_exch_range = (PCPU_MIN_UNIT_SIZE - sizeof(*pool)) /
sizeof(struct fc_exch *);
if ((max_xid - min_xid + 1) / (fc_cpu_mask + 1) > pool_exch_range) {
mp->max_xid = pool_exch_range * (fc_cpu_mask + 1) +
min_xid - 1;
} else {
mp->max_xid = max_xid;
pool_exch_range = (mp->max_xid - mp->min_xid + 1) /
(fc_cpu_mask + 1);
}
mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
if (!mp->ep_pool)
goto free_mp;
/*
* Setup per cpu exch pool with entire exchange id range equally
* divided across all cpus. The exch pointers array memory is
* allocated for exch range per pool.
*/
mp->pool_max_index = pool_exch_range - 1;
/*
* Allocate and initialize per cpu exch pool
*/
pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
if (!mp->pool)
goto free_mempool;
for_each_possible_cpu(cpu) {
pool = per_cpu_ptr(mp->pool, cpu);
pool->next_index = 0;
pool->left = FC_XID_UNKNOWN;
pool->right = FC_XID_UNKNOWN;
spin_lock_init(&pool->lock);
INIT_LIST_HEAD(&pool->ex_list);
}
kref_init(&mp->kref);
if (!fc_exch_mgr_add(lport, mp, match)) {
free_percpu(mp->pool);
goto free_mempool;
}
/*
* Above kref_init() sets mp->kref to 1 and then
* call to fc_exch_mgr_add incremented mp->kref again,
* so adjust that extra increment.
*/
kref_put(&mp->kref, fc_exch_mgr_destroy);
return mp;
free_mempool:
mempool_destroy(mp->ep_pool);
free_mp:
kfree(mp);
return NULL;
}
EXPORT_SYMBOL(fc_exch_mgr_alloc);
/**
* fc_exch_mgr_free() - Free all exchange managers on a local port
* @lport: The local port whose EMs are to be freed
*/
void fc_exch_mgr_free(struct fc_lport *lport)
{
struct fc_exch_mgr_anchor *ema, *next;
flush_workqueue(fc_exch_workqueue);
list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
fc_exch_mgr_del(ema);
}
EXPORT_SYMBOL(fc_exch_mgr_free);
/**
* fc_find_ema() - Lookup and return appropriate Exchange Manager Anchor depending
* upon 'xid'.
* @f_ctl: f_ctl
* @lport: The local port the frame was received on
* @fh: The received frame header
*/
static struct fc_exch_mgr_anchor *fc_find_ema(u32 f_ctl,
struct fc_lport *lport,
struct fc_frame_header *fh)
{
struct fc_exch_mgr_anchor *ema;
u16 xid;
if (f_ctl & FC_FC_EX_CTX)
xid = ntohs(fh->fh_ox_id);
else {
xid = ntohs(fh->fh_rx_id);
if (xid == FC_XID_UNKNOWN)
return list_entry(lport->ema_list.prev,
typeof(*ema), ema_list);
}
list_for_each_entry(ema, &lport->ema_list, ema_list) {
if ((xid >= ema->mp->min_xid) &&
(xid <= ema->mp->max_xid))
return ema;
}
return NULL;
}
/**
* fc_exch_recv() - Handler for received frames
* @lport: The local port the frame was received on
* @fp: The received frame
*/
void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)
{
struct fc_frame_header *fh = fc_frame_header_get(fp);
struct fc_exch_mgr_anchor *ema;
u32 f_ctl;
/* lport lock ? */
if (!lport || lport->state == LPORT_ST_DISABLED) {
FC_LPORT_DBG(lport, "Receiving frames for an lport that "
"has not been initialized correctly\n");
fc_frame_free(fp);
return;
}
f_ctl = ntoh24(fh->fh_f_ctl);
ema = fc_find_ema(f_ctl, lport, fh);
if (!ema) {
FC_LPORT_DBG(lport, "Unable to find Exchange Manager Anchor,"
"fc_ctl <0x%x>, xid <0x%x>\n",
f_ctl,
(f_ctl & FC_FC_EX_CTX) ?
ntohs(fh->fh_ox_id) :
ntohs(fh->fh_rx_id));
fc_frame_free(fp);
return;
}
/*
* If frame is marked invalid, just drop it.
*/
switch (fr_eof(fp)) {
case FC_EOF_T:
if (f_ctl & FC_FC_END_SEQ)
skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
/* fall through */
case FC_EOF_N:
if (fh->fh_type == FC_TYPE_BLS)
fc_exch_recv_bls(ema->mp, fp);
else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
FC_FC_EX_CTX)
fc_exch_recv_seq_resp(ema->mp, fp);
else if (f_ctl & FC_FC_SEQ_CTX)
fc_exch_recv_resp(ema->mp, fp);
else /* no EX_CTX and no SEQ_CTX */
fc_exch_recv_req(lport, ema->mp, fp);
break;
default:
FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)",
fr_eof(fp));
fc_frame_free(fp);
}
}
EXPORT_SYMBOL(fc_exch_recv);
/**
* fc_exch_init() - Initialize the exchange layer for a local port
* @lport: The local port to initialize the exchange layer for
*/
int fc_exch_init(struct fc_lport *lport)
{
if (!lport->tt.seq_start_next)
lport->tt.seq_start_next = fc_seq_start_next;
if (!lport->tt.seq_set_resp)
lport->tt.seq_set_resp = fc_seq_set_resp;
if (!lport->tt.exch_seq_send)
lport->tt.exch_seq_send = fc_exch_seq_send;
if (!lport->tt.seq_send)
lport->tt.seq_send = fc_seq_send;
if (!lport->tt.seq_els_rsp_send)
lport->tt.seq_els_rsp_send = fc_seq_els_rsp_send;
if (!lport->tt.exch_done)
lport->tt.exch_done = fc_exch_done;
if (!lport->tt.exch_mgr_reset)
lport->tt.exch_mgr_reset = fc_exch_mgr_reset;
if (!lport->tt.seq_exch_abort)
lport->tt.seq_exch_abort = fc_seq_exch_abort;
if (!lport->tt.seq_assign)
lport->tt.seq_assign = fc_seq_assign;
if (!lport->tt.seq_release)
lport->tt.seq_release = fc_seq_release;
return 0;
}
EXPORT_SYMBOL(fc_exch_init);
/**
* fc_setup_exch_mgr() - Setup an exchange manager
*/
int fc_setup_exch_mgr(void)
{
fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
0, SLAB_HWCACHE_ALIGN, NULL);
if (!fc_em_cachep)
return -ENOMEM;
/*
* Initialize fc_cpu_mask and fc_cpu_order. The
* fc_cpu_mask is set for nr_cpu_ids rounded up
* to order of 2's * power and order is stored
* in fc_cpu_order as this is later required in
* mapping between an exch id and exch array index
* in per cpu exch pool.
*
* This round up is required to align fc_cpu_mask
* to exchange id's lower bits such that all incoming
* frames of an exchange gets delivered to the same
* cpu on which exchange originated by simple bitwise
* AND operation between fc_cpu_mask and exchange id.
*/
fc_cpu_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);
}
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