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1/*
2 * Copyright(c) 2007 Intel Corporation. All rights reserved.
3 * Copyright(c) 2008 Red Hat, Inc.  All rights reserved.
4 * Copyright(c) 2008 Mike Christie
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Maintained at www.Open-FCoE.org
20 */
21
22#include <linux/module.h>
23#include <linux/delay.h>
24#include <linux/kernel.h>
25#include <linux/types.h>
26#include <linux/spinlock.h>
27#include <linux/scatterlist.h>
28#include <linux/err.h>
29#include <linux/crc32.h>
30#include <linux/slab.h>
31
32#include <scsi/scsi_tcq.h>
33#include <scsi/scsi.h>
34#include <scsi/scsi_host.h>
35#include <scsi/scsi_device.h>
36#include <scsi/scsi_cmnd.h>
37
38#include <scsi/fc/fc_fc2.h>
39
40#include <scsi/libfc.h>
41#include <scsi/fc_encode.h>
42
43#include "fc_libfc.h"
44
45struct kmem_cache *scsi_pkt_cachep;
46
47/* SRB state definitions */
48#define FC_SRB_FREE		0		/* cmd is free */
49#define FC_SRB_CMD_SENT		(1 << 0)	/* cmd has been sent */
50#define FC_SRB_RCV_STATUS	(1 << 1)	/* response has arrived */
51#define FC_SRB_ABORT_PENDING	(1 << 2)	/* cmd abort sent to device */
52#define FC_SRB_ABORTED		(1 << 3)	/* abort acknowledged */
53#define FC_SRB_DISCONTIG	(1 << 4)	/* non-sequential data recvd */
54#define FC_SRB_COMPL		(1 << 5)	/* fc_io_compl has been run */
55#define FC_SRB_FCP_PROCESSING_TMO (1 << 6)	/* timer function processing */
56
57#define FC_SRB_READ		(1 << 1)
58#define FC_SRB_WRITE		(1 << 0)
59
60/*
61 * The SCp.ptr should be tested and set under the host lock. NULL indicates
62 * that the command has been retruned to the scsi layer.
63 */
64#define CMD_SP(Cmnd)		    ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)
65#define CMD_ENTRY_STATUS(Cmnd)	    ((Cmnd)->SCp.have_data_in)
66#define CMD_COMPL_STATUS(Cmnd)	    ((Cmnd)->SCp.this_residual)
67#define CMD_SCSI_STATUS(Cmnd)	    ((Cmnd)->SCp.Status)
68#define CMD_RESID_LEN(Cmnd)	    ((Cmnd)->SCp.buffers_residual)
69
70/**
71 * struct fc_fcp_internal - FCP layer internal data
72 * @scsi_pkt_pool: Memory pool to draw FCP packets from
73 * @scsi_queue_lock: Protects the scsi_pkt_queue
74 * @scsi_pkt_queue: Current FCP packets
75 * @last_can_queue_ramp_down_time: ramp down time
76 * @last_can_queue_ramp_up_time: ramp up time
77 * @max_can_queue: max can_queue size
78 */
79struct fc_fcp_internal {
80	mempool_t		*scsi_pkt_pool;
81	spinlock_t		scsi_queue_lock;
82	struct list_head	scsi_pkt_queue;
83	unsigned long		last_can_queue_ramp_down_time;
84	unsigned long		last_can_queue_ramp_up_time;
85	int			max_can_queue;
86};
87
88#define fc_get_scsi_internal(x)	((struct fc_fcp_internal *)(x)->scsi_priv)
89
90/*
91 * function prototypes
92 * FC scsi I/O related functions
93 */
94static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
95static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
96static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
97static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
98static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
99static void fc_fcp_error(struct fc_fcp_pkt *, struct fc_frame *);
100static void fc_fcp_recovery(struct fc_fcp_pkt *);
101static void fc_fcp_timeout(unsigned long);
102static void fc_fcp_rec(struct fc_fcp_pkt *);
103static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
104static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
105static void fc_io_compl(struct fc_fcp_pkt *);
106
107static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
108static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
109static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
110
111/*
112 * command status codes
113 */
114#define FC_COMPLETE		0
115#define FC_CMD_ABORTED		1
116#define FC_CMD_RESET		2
117#define FC_CMD_PLOGO		3
118#define FC_SNS_RCV		4
119#define FC_TRANS_ERR		5
120#define FC_DATA_OVRRUN		6
121#define FC_DATA_UNDRUN		7
122#define FC_ERROR		8
123#define FC_HRD_ERROR		9
124#define FC_CMD_RECOVERY		10
125
126/*
127 * Error recovery timeout values.
128 */
129#define FC_SCSI_ER_TIMEOUT	(10 * HZ)
130#define FC_SCSI_TM_TOV		(10 * HZ)
131#define FC_SCSI_REC_TOV		(2 * HZ)
132#define FC_HOST_RESET_TIMEOUT	(30 * HZ)
133#define FC_CAN_QUEUE_PERIOD	(60 * HZ)
134
135#define FC_MAX_ERROR_CNT	5
136#define FC_MAX_RECOV_RETRY	3
137
138#define FC_FCP_DFLT_QUEUE_DEPTH 32
139
140/**
141 * fc_fcp_pkt_alloc() - Allocate a fcp_pkt
142 * @lport: The local port that the FCP packet is for
143 * @gfp:   GFP flags for allocation
144 *
145 * Return value: fcp_pkt structure or null on allocation failure.
146 * Context:	 Can be called from process context, no lock is required.
147 */
148static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lport, gfp_t gfp)
149{
150	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
151	struct fc_fcp_pkt *fsp;
152
153	fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
154	if (fsp) {
155		memset(fsp, 0, sizeof(*fsp));
156		fsp->lp = lport;
157		atomic_set(&fsp->ref_cnt, 1);
158		init_timer(&fsp->timer);
159		INIT_LIST_HEAD(&fsp->list);
160		spin_lock_init(&fsp->scsi_pkt_lock);
161	}
162	return fsp;
163}
164
165/**
166 * fc_fcp_pkt_release() - Release hold on a fcp_pkt
167 * @fsp: The FCP packet to be released
168 *
169 * Context: Can be called from process or interrupt context,
170 *	    no lock is required.
171 */
172static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
173{
174	if (atomic_dec_and_test(&fsp->ref_cnt)) {
175		struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
176
177		mempool_free(fsp, si->scsi_pkt_pool);
178	}
179}
180
181/**
182 * fc_fcp_pkt_hold() - Hold a fcp_pkt
183 * @fsp: The FCP packet to be held
184 */
185static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
186{
187	atomic_inc(&fsp->ref_cnt);
188}
189
190/**
191 * fc_fcp_pkt_destory() - Release hold on a fcp_pkt
192 * @seq: The sequence that the FCP packet is on (required by destructor API)
193 * @fsp: The FCP packet to be released
194 *
195 * This routine is called by a destructor callback in the exch_seq_send()
196 * routine of the libfc Transport Template. The 'struct fc_seq' is a required
197 * argument even though it is not used by this routine.
198 *
199 * Context: No locking required.
200 */
201static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
202{
203	fc_fcp_pkt_release(fsp);
204}
205
206/**
207 * fc_fcp_lock_pkt() - Lock a fcp_pkt and increase its reference count
208 * @fsp: The FCP packet to be locked and incremented
209 *
210 * We should only return error if we return a command to SCSI-ml before
211 * getting a response. This can happen in cases where we send a abort, but
212 * do not wait for the response and the abort and command can be passing
213 * each other on the wire/network-layer.
214 *
215 * Note: this function locks the packet and gets a reference to allow
216 * callers to call the completion function while the lock is held and
217 * not have to worry about the packets refcount.
218 *
219 * TODO: Maybe we should just have callers grab/release the lock and
220 * have a function that they call to verify the fsp and grab a ref if
221 * needed.
222 */
223static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
224{
225	spin_lock_bh(&fsp->scsi_pkt_lock);
226	if (fsp->state & FC_SRB_COMPL) {
227		spin_unlock_bh(&fsp->scsi_pkt_lock);
228		return -EPERM;
229	}
230
231	fc_fcp_pkt_hold(fsp);
232	return 0;
233}
234
235/**
236 * fc_fcp_unlock_pkt() - Release a fcp_pkt's lock and decrement its
237 *			 reference count
238 * @fsp: The FCP packet to be unlocked and decremented
239 */
240static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
241{
242	spin_unlock_bh(&fsp->scsi_pkt_lock);
243	fc_fcp_pkt_release(fsp);
244}
245
246/**
247 * fc_fcp_timer_set() - Start a timer for a fcp_pkt
248 * @fsp:   The FCP packet to start a timer for
249 * @delay: The timeout period for the timer
250 */
251static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
252{
253	if (!(fsp->state & FC_SRB_COMPL))
254		mod_timer(&fsp->timer, jiffies + delay);
255}
256
257/**
258 * fc_fcp_send_abort() - Send an abort for exchanges associated with a
259 *			 fcp_pkt
260 * @fsp: The FCP packet to abort exchanges on
261 */
262static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
263{
264	if (!fsp->seq_ptr)
265		return -EINVAL;
266
267	fsp->state |= FC_SRB_ABORT_PENDING;
268	return fsp->lp->tt.seq_exch_abort(fsp->seq_ptr, 0);
269}
270
271/**
272 * fc_fcp_retry_cmd() - Retry a fcp_pkt
273 * @fsp: The FCP packet to be retried
274 *
275 * Sets the status code to be FC_ERROR and then calls
276 * fc_fcp_complete_locked() which in turn calls fc_io_compl().
277 * fc_io_compl() will notify the SCSI-ml that the I/O is done.
278 * The SCSI-ml will retry the command.
279 */
280static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp)
281{
282	if (fsp->seq_ptr) {
283		fsp->lp->tt.exch_done(fsp->seq_ptr);
284		fsp->seq_ptr = NULL;
285	}
286
287	fsp->state &= ~FC_SRB_ABORT_PENDING;
288	fsp->io_status = 0;
289	fsp->status_code = FC_ERROR;
290	fc_fcp_complete_locked(fsp);
291}
292
293/**
294 * fc_fcp_ddp_setup() - Calls a LLD's ddp_setup routine to set up DDP context
295 * @fsp: The FCP packet that will manage the DDP frames
296 * @xid: The XID that will be used for the DDP exchange
297 */
298void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
299{
300	struct fc_lport *lport;
301
302	lport = fsp->lp;
303	if ((fsp->req_flags & FC_SRB_READ) &&
304	    (lport->lro_enabled) && (lport->tt.ddp_setup)) {
305		if (lport->tt.ddp_setup(lport, xid, scsi_sglist(fsp->cmd),
306					scsi_sg_count(fsp->cmd)))
307			fsp->xfer_ddp = xid;
308	}
309}
310
311/**
312 * fc_fcp_ddp_done() - Calls a LLD's ddp_done routine to release any
313 *		       DDP related resources for a fcp_pkt
314 * @fsp: The FCP packet that DDP had been used on
315 */
316static void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
317{
318	struct fc_lport *lport;
319
320	if (!fsp)
321		return;
322
323	if (fsp->xfer_ddp == FC_XID_UNKNOWN)
324		return;
325
326	lport = fsp->lp;
327	if (lport->tt.ddp_done) {
328		fsp->xfer_len = lport->tt.ddp_done(lport, fsp->xfer_ddp);
329		fsp->xfer_ddp = FC_XID_UNKNOWN;
330	}
331}
332
333/**
334 * fc_fcp_can_queue_ramp_up() - increases can_queue
335 * @lport: lport to ramp up can_queue
336 *
337 * Locking notes: Called with Scsi_Host lock held
338 */
339static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
340{
341	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
342	int can_queue;
343
344	if (si->last_can_queue_ramp_up_time &&
345	    (time_before(jiffies, si->last_can_queue_ramp_up_time +
346			 FC_CAN_QUEUE_PERIOD)))
347		return;
348
349	if (time_before(jiffies, si->last_can_queue_ramp_down_time +
350			FC_CAN_QUEUE_PERIOD))
351		return;
352
353	si->last_can_queue_ramp_up_time = jiffies;
354
355	can_queue = lport->host->can_queue << 1;
356	if (can_queue >= si->max_can_queue) {
357		can_queue = si->max_can_queue;
358		si->last_can_queue_ramp_down_time = 0;
359	}
360	lport->host->can_queue = can_queue;
361	shost_printk(KERN_ERR, lport->host, "libfc: increased "
362		     "can_queue to %d.\n", can_queue);
363}
364
365/**
366 * fc_fcp_can_queue_ramp_down() - reduces can_queue
367 * @lport: lport to reduce can_queue
368 *
369 * If we are getting memory allocation failures, then we may
370 * be trying to execute too many commands. We let the running
371 * commands complete or timeout, then try again with a reduced
372 * can_queue. Eventually we will hit the point where we run
373 * on all reserved structs.
374 *
375 * Locking notes: Called with Scsi_Host lock held
376 */
377static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport)
378{
379	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
380	int can_queue;
381
382	if (si->last_can_queue_ramp_down_time &&
383	    (time_before(jiffies, si->last_can_queue_ramp_down_time +
384			 FC_CAN_QUEUE_PERIOD)))
385		return;
386
387	si->last_can_queue_ramp_down_time = jiffies;
388
389	can_queue = lport->host->can_queue;
390	can_queue >>= 1;
391	if (!can_queue)
392		can_queue = 1;
393	lport->host->can_queue = can_queue;
394	shost_printk(KERN_ERR, lport->host, "libfc: Could not allocate frame.\n"
395		     "Reducing can_queue to %d.\n", can_queue);
396}
397
398/*
399 * fc_fcp_frame_alloc() -  Allocates fc_frame structure and buffer.
400 * @lport:	fc lport struct
401 * @len:	payload length
402 *
403 * Allocates fc_frame structure and buffer but if fails to allocate
404 * then reduce can_queue.
405 */
406static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport,
407						  size_t len)
408{
409	struct fc_frame *fp;
410	unsigned long flags;
411
412	fp = fc_frame_alloc(lport, len);
413	if (likely(fp))
414		return fp;
415
416	/* error case */
417	spin_lock_irqsave(lport->host->host_lock, flags);
418	fc_fcp_can_queue_ramp_down(lport);
419	spin_unlock_irqrestore(lport->host->host_lock, flags);
420	return NULL;
421}
422
423/**
424 * fc_fcp_recv_data() - Handler for receiving SCSI-FCP data from a target
425 * @fsp: The FCP packet the data is on
426 * @fp:	 The data frame
427 */
428static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
429{
430	struct scsi_cmnd *sc = fsp->cmd;
431	struct fc_lport *lport = fsp->lp;
432	struct fcoe_dev_stats *stats;
433	struct fc_frame_header *fh;
434	size_t start_offset;
435	size_t offset;
436	u32 crc;
437	u32 copy_len = 0;
438	size_t len;
439	void *buf;
440	struct scatterlist *sg;
441	u32 nents;
442
443	fh = fc_frame_header_get(fp);
444	offset = ntohl(fh->fh_parm_offset);
445	start_offset = offset;
446	len = fr_len(fp) - sizeof(*fh);
447	buf = fc_frame_payload_get(fp, 0);
448
449	/*
450	 * if this I/O is ddped then clear it
451	 * and initiate recovery since data
452	 * frames are expected to be placed
453	 * directly in that case.
454	 */
455	if (fsp->xfer_ddp != FC_XID_UNKNOWN) {
456		fc_fcp_ddp_done(fsp);
457		goto err;
458	}
459	if (offset + len > fsp->data_len) {
460		/* this should never happen */
461		if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
462		    fc_frame_crc_check(fp))
463			goto crc_err;
464		FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
465			   "data_len %x\n", len, offset, fsp->data_len);
466		goto err;
467	}
468	if (offset != fsp->xfer_len)
469		fsp->state |= FC_SRB_DISCONTIG;
470
471	sg = scsi_sglist(sc);
472	nents = scsi_sg_count(sc);
473
474	if (!(fr_flags(fp) & FCPHF_CRC_UNCHECKED)) {
475		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
476						    &offset, KM_SOFTIRQ0, NULL);
477	} else {
478		crc = crc32(~0, (u8 *) fh, sizeof(*fh));
479		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
480						    &offset, KM_SOFTIRQ0, &crc);
481		buf = fc_frame_payload_get(fp, 0);
482		if (len % 4)
483			crc = crc32(crc, buf + len, 4 - (len % 4));
484
485		if (~crc != le32_to_cpu(fr_crc(fp))) {
486crc_err:
487			stats = per_cpu_ptr(lport->dev_stats, get_cpu());
488			stats->ErrorFrames++;
489			/* per cpu count, not total count, but OK for limit */
490			if (stats->InvalidCRCCount++ < 5)
491				printk(KERN_WARNING "libfc: CRC error on data "
492				       "frame for port (%6.6x)\n",
493				       lport->port_id);
494			put_cpu();
495			/*
496			 * Assume the frame is total garbage.
497			 * We may have copied it over the good part
498			 * of the buffer.
499			 * If so, we need to retry the entire operation.
500			 * Otherwise, ignore it.
501			 */
502			if (fsp->state & FC_SRB_DISCONTIG)
503				goto err;
504			return;
505		}
506	}
507
508	if (fsp->xfer_contig_end == start_offset)
509		fsp->xfer_contig_end += copy_len;
510	fsp->xfer_len += copy_len;
511
512	/*
513	 * In the very rare event that this data arrived after the response
514	 * and completes the transfer, call the completion handler.
515	 */
516	if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
517	    fsp->xfer_len == fsp->data_len - fsp->scsi_resid)
518		fc_fcp_complete_locked(fsp);
519	return;
520err:
521	fc_fcp_recovery(fsp);
522}
523
524/**
525 * fc_fcp_send_data() - Send SCSI data to a target
526 * @fsp:      The FCP packet the data is on
527 * @sp:	      The sequence the data is to be sent on
528 * @offset:   The starting offset for this data request
529 * @seq_blen: The burst length for this data request
530 *
531 * Called after receiving a Transfer Ready data descriptor.
532 * If the LLD is capable of sequence offload then send down the
533 * seq_blen amount of data in single frame, otherwise send
534 * multiple frames of the maximum frame payload supported by
535 * the target port.
536 */
537static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
538			    size_t offset, size_t seq_blen)
539{
540	struct fc_exch *ep;
541	struct scsi_cmnd *sc;
542	struct scatterlist *sg;
543	struct fc_frame *fp = NULL;
544	struct fc_lport *lport = fsp->lp;
545	struct page *page;
546	size_t remaining;
547	size_t t_blen;
548	size_t tlen;
549	size_t sg_bytes;
550	size_t frame_offset, fh_parm_offset;
551	size_t off;
552	int error;
553	void *data = NULL;
554	void *page_addr;
555	int using_sg = lport->sg_supp;
556	u32 f_ctl;
557
558	WARN_ON(seq_blen <= 0);
559	if (unlikely(offset + seq_blen > fsp->data_len)) {
560		/* this should never happen */
561		FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
562			   "offset %zx\n", seq_blen, offset);
563		fc_fcp_send_abort(fsp);
564		return 0;
565	} else if (offset != fsp->xfer_len) {
566		/* Out of Order Data Request - no problem, but unexpected. */
567		FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
568			   "seq_blen %zx offset %zx\n", seq_blen, offset);
569	}
570
571	/*
572	 * if LLD is capable of seq_offload then set transport
573	 * burst length (t_blen) to seq_blen, otherwise set t_blen
574	 * to max FC frame payload previously set in fsp->max_payload.
575	 */
576	t_blen = fsp->max_payload;
577	if (lport->seq_offload) {
578		t_blen = min(seq_blen, (size_t)lport->lso_max);
579		FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
580			   fsp, seq_blen, lport->lso_max, t_blen);
581	}
582
583	if (t_blen > 512)
584		t_blen &= ~(512 - 1);	/* round down to block size */
585	sc = fsp->cmd;
586
587	remaining = seq_blen;
588	fh_parm_offset = frame_offset = offset;
589	tlen = 0;
590	seq = lport->tt.seq_start_next(seq);
591	f_ctl = FC_FC_REL_OFF;
592	WARN_ON(!seq);
593
594	sg = scsi_sglist(sc);
595
596	while (remaining > 0 && sg) {
597		if (offset >= sg->length) {
598			offset -= sg->length;
599			sg = sg_next(sg);
600			continue;
601		}
602		if (!fp) {
603			tlen = min(t_blen, remaining);
604
605			if (tlen % 4)
606				using_sg = 0;
607			fp = fc_frame_alloc(lport, using_sg ? 0 : tlen);
608			if (!fp)
609				return -ENOMEM;
610
611			data = fc_frame_header_get(fp) + 1;
612			fh_parm_offset = frame_offset;
613			fr_max_payload(fp) = fsp->max_payload;
614		}
615
616		off = offset + sg->offset;
617		sg_bytes = min(tlen, sg->length - offset);
618		sg_bytes = min(sg_bytes,
619			       (size_t) (PAGE_SIZE - (off & ~PAGE_MASK)));
620		page = sg_page(sg) + (off >> PAGE_SHIFT);
621		if (using_sg) {
622			get_page(page);
623			skb_fill_page_desc(fp_skb(fp),
624					   skb_shinfo(fp_skb(fp))->nr_frags,
625					   page, off & ~PAGE_MASK, sg_bytes);
626			fp_skb(fp)->data_len += sg_bytes;
627			fr_len(fp) += sg_bytes;
628			fp_skb(fp)->truesize += PAGE_SIZE;
629		} else {
630			/*
631			 * The scatterlist item may be bigger than PAGE_SIZE,
632			 * but we must not cross pages inside the kmap.
633			 */
634			page_addr = kmap_atomic(page, KM_SOFTIRQ0);
635			memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
636			       sg_bytes);
637			kunmap_atomic(page_addr, KM_SOFTIRQ0);
638			data += sg_bytes;
639		}
640		offset += sg_bytes;
641		frame_offset += sg_bytes;
642		tlen -= sg_bytes;
643		remaining -= sg_bytes;
644
645		if ((skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN) &&
646		    (tlen))
647			continue;
648
649		/*
650		 * Send sequence with transfer sequence initiative in case
651		 * this is last FCP frame of the sequence.
652		 */
653		if (remaining == 0)
654			f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
655
656		ep = fc_seq_exch(seq);
657		fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
658			       FC_TYPE_FCP, f_ctl, fh_parm_offset);
659
660		/*
661		 * send fragment using for a sequence.
662		 */
663		error = lport->tt.seq_send(lport, seq, fp);
664		if (error) {
665			WARN_ON(1);		/* send error should be rare */
666			fc_fcp_retry_cmd(fsp);
667			return 0;
668		}
669		fp = NULL;
670	}
671	fsp->xfer_len += seq_blen;	/* premature count? */
672	return 0;
673}
674
675/**
676 * fc_fcp_abts_resp() - Send an ABTS response
677 * @fsp: The FCP packet that is being aborted
678 * @fp:	 The response frame
679 */
680static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
681{
682	int ba_done = 1;
683	struct fc_ba_rjt *brp;
684	struct fc_frame_header *fh;
685
686	fh = fc_frame_header_get(fp);
687	switch (fh->fh_r_ctl) {
688	case FC_RCTL_BA_ACC:
689		break;
690	case FC_RCTL_BA_RJT:
691		brp = fc_frame_payload_get(fp, sizeof(*brp));
692		if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
693			break;
694		/* fall thru */
695	default:
696		/*
697		 * we will let the command timeout
698		 * and scsi-ml recover in this case,
699		 * therefore cleared the ba_done flag.
700		 */
701		ba_done = 0;
702	}
703
704	if (ba_done) {
705		fsp->state |= FC_SRB_ABORTED;
706		fsp->state &= ~FC_SRB_ABORT_PENDING;
707
708		if (fsp->wait_for_comp)
709			complete(&fsp->tm_done);
710		else
711			fc_fcp_complete_locked(fsp);
712	}
713}
714
715/**
716 * fc_fcp_recv() - Reveive an FCP frame
717 * @seq: The sequence the frame is on
718 * @fp:	 The received frame
719 * @arg: The related FCP packet
720 *
721 * Context: Called from Soft IRQ context. Can not be called
722 *	    holding the FCP packet list lock.
723 */
724static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
725{
726	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
727	struct fc_lport *lport = fsp->lp;
728	struct fc_frame_header *fh;
729	struct fcp_txrdy *dd;
730	u8 r_ctl;
731	int rc = 0;
732
733	if (IS_ERR(fp)) {
734		fc_fcp_error(fsp, fp);
735		return;
736	}
737
738	fh = fc_frame_header_get(fp);
739	r_ctl = fh->fh_r_ctl;
740
741	if (lport->state != LPORT_ST_READY)
742		goto out;
743	if (fc_fcp_lock_pkt(fsp))
744		goto out;
745	fsp->last_pkt_time = jiffies;
746
747	if (fh->fh_type == FC_TYPE_BLS) {
748		fc_fcp_abts_resp(fsp, fp);
749		goto unlock;
750	}
751
752	if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING))
753		goto unlock;
754
755	if (r_ctl == FC_RCTL_DD_DATA_DESC) {
756		/*
757		 * received XFER RDY from the target
758		 * need to send data to the target
759		 */
760		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
761		dd = fc_frame_payload_get(fp, sizeof(*dd));
762		WARN_ON(!dd);
763
764		rc = fc_fcp_send_data(fsp, seq,
765				      (size_t) ntohl(dd->ft_data_ro),
766				      (size_t) ntohl(dd->ft_burst_len));
767		if (!rc)
768			seq->rec_data = fsp->xfer_len;
769	} else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
770		/*
771		 * received a DATA frame
772		 * next we will copy the data to the system buffer
773		 */
774		WARN_ON(fr_len(fp) < sizeof(*fh));	/* len may be 0 */
775		fc_fcp_recv_data(fsp, fp);
776		seq->rec_data = fsp->xfer_contig_end;
777	} else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
778		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
779
780		fc_fcp_resp(fsp, fp);
781	} else {
782		FC_FCP_DBG(fsp, "unexpected frame.  r_ctl %x\n", r_ctl);
783	}
784unlock:
785	fc_fcp_unlock_pkt(fsp);
786out:
787	fc_frame_free(fp);
788}
789
790/**
791 * fc_fcp_resp() - Handler for FCP responses
792 * @fsp: The FCP packet the response is for
793 * @fp:	 The response frame
794 */
795static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
796{
797	struct fc_frame_header *fh;
798	struct fcp_resp *fc_rp;
799	struct fcp_resp_ext *rp_ex;
800	struct fcp_resp_rsp_info *fc_rp_info;
801	u32 plen;
802	u32 expected_len;
803	u32 respl = 0;
804	u32 snsl = 0;
805	u8 flags = 0;
806
807	plen = fr_len(fp);
808	fh = (struct fc_frame_header *)fr_hdr(fp);
809	if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
810		goto len_err;
811	plen -= sizeof(*fh);
812	fc_rp = (struct fcp_resp *)(fh + 1);
813	fsp->cdb_status = fc_rp->fr_status;
814	flags = fc_rp->fr_flags;
815	fsp->scsi_comp_flags = flags;
816	expected_len = fsp->data_len;
817
818	/* if ddp, update xfer len */
819	fc_fcp_ddp_done(fsp);
820
821	if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
822		rp_ex = (void *)(fc_rp + 1);
823		if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
824			if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
825				goto len_err;
826			fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
827			if (flags & FCP_RSP_LEN_VAL) {
828				respl = ntohl(rp_ex->fr_rsp_len);
829				if (respl != sizeof(*fc_rp_info))
830					goto len_err;
831				if (fsp->wait_for_comp) {
832					/* Abuse cdb_status for rsp code */
833					fsp->cdb_status = fc_rp_info->rsp_code;
834					complete(&fsp->tm_done);
835					/*
836					 * tmfs will not have any scsi cmd so
837					 * exit here
838					 */
839					return;
840				}
841			}
842			if (flags & FCP_SNS_LEN_VAL) {
843				snsl = ntohl(rp_ex->fr_sns_len);
844				if (snsl > SCSI_SENSE_BUFFERSIZE)
845					snsl = SCSI_SENSE_BUFFERSIZE;
846				memcpy(fsp->cmd->sense_buffer,
847				       (char *)fc_rp_info + respl, snsl);
848			}
849		}
850		if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
851			if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
852				goto len_err;
853			if (flags & FCP_RESID_UNDER) {
854				fsp->scsi_resid = ntohl(rp_ex->fr_resid);
855				/*
856				 * The cmnd->underflow is the minimum number of
857				 * bytes that must be transfered for this
858				 * command.  Provided a sense condition is not
859				 * present, make sure the actual amount
860				 * transferred is at least the underflow value
861				 * or fail.
862				 */
863				if (!(flags & FCP_SNS_LEN_VAL) &&
864				    (fc_rp->fr_status == 0) &&
865				    (scsi_bufflen(fsp->cmd) -
866				     fsp->scsi_resid) < fsp->cmd->underflow)
867					goto err;
868				expected_len -= fsp->scsi_resid;
869			} else {
870				fsp->status_code = FC_ERROR;
871			}
872		}
873	}
874	fsp->state |= FC_SRB_RCV_STATUS;
875
876	/*
877	 * Check for missing or extra data frames.
878	 */
879	if (unlikely(fsp->xfer_len != expected_len)) {
880		if (fsp->xfer_len < expected_len) {
881			/*
882			 * Some data may be queued locally,
883			 * Wait a at least one jiffy to see if it is delivered.
884			 * If this expires without data, we may do SRR.
885			 */
886			fc_fcp_timer_set(fsp, 2);
887			return;
888		}
889		fsp->status_code = FC_DATA_OVRRUN;
890		FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx greater than expected, "
891			   "len %x, data len %x\n",
892			   fsp->rport->port_id,
893			   fsp->xfer_len, expected_len, fsp->data_len);
894	}
895	fc_fcp_complete_locked(fsp);
896	return;
897
898len_err:
899	FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
900		   "snsl %u\n", flags, fr_len(fp), respl, snsl);
901err:
902	fsp->status_code = FC_ERROR;
903	fc_fcp_complete_locked(fsp);
904}
905
906/**
907 * fc_fcp_complete_locked() - Complete processing of a fcp_pkt with the
908 *			      fcp_pkt lock held
909 * @fsp: The FCP packet to be completed
910 *
911 * This function may sleep if a timer is pending. The packet lock must be
912 * held, and the host lock must not be held.
913 */
914static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
915{
916	struct fc_lport *lport = fsp->lp;
917	struct fc_seq *seq;
918	struct fc_exch *ep;
919	u32 f_ctl;
920
921	if (fsp->state & FC_SRB_ABORT_PENDING)
922		return;
923
924	if (fsp->state & FC_SRB_ABORTED) {
925		if (!fsp->status_code)
926			fsp->status_code = FC_CMD_ABORTED;
927	} else {
928		/*
929		 * Test for transport underrun, independent of response
930		 * underrun status.
931		 */
932		if (fsp->xfer_len < fsp->data_len && !fsp->io_status &&
933		    (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
934		     fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
935			fsp->status_code = FC_DATA_UNDRUN;
936			fsp->io_status = 0;
937		}
938	}
939
940	seq = fsp->seq_ptr;
941	if (seq) {
942		fsp->seq_ptr = NULL;
943		if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
944			struct fc_frame *conf_frame;
945			struct fc_seq *csp;
946
947			csp = lport->tt.seq_start_next(seq);
948			conf_frame = fc_fcp_frame_alloc(fsp->lp, 0);
949			if (conf_frame) {
950				f_ctl = FC_FC_SEQ_INIT;
951				f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
952				ep = fc_seq_exch(seq);
953				fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
954					       ep->did, ep->sid,
955					       FC_TYPE_FCP, f_ctl, 0);
956				lport->tt.seq_send(lport, csp, conf_frame);
957			}
958		}
959		lport->tt.exch_done(seq);
960	}
961	fc_io_compl(fsp);
962}
963
964/**
965 * fc_fcp_cleanup_cmd() - Cancel the active exchange on a fcp_pkt
966 * @fsp:   The FCP packet whose exchanges should be canceled
967 * @error: The reason for the cancellation
968 */
969static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
970{
971	struct fc_lport *lport = fsp->lp;
972
973	if (fsp->seq_ptr) {
974		lport->tt.exch_done(fsp->seq_ptr);
975		fsp->seq_ptr = NULL;
976	}
977	fsp->status_code = error;
978}
979
980/**
981 * fc_fcp_cleanup_each_cmd() - Cancel all exchanges on a local port
982 * @lport: The local port whose exchanges should be canceled
983 * @id:	   The target's ID
984 * @lun:   The LUN
985 * @error: The reason for cancellation
986 *
987 * If lun or id is -1, they are ignored.
988 */
989static void fc_fcp_cleanup_each_cmd(struct fc_lport *lport, unsigned int id,
990				    unsigned int lun, int error)
991{
992	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
993	struct fc_fcp_pkt *fsp;
994	struct scsi_cmnd *sc_cmd;
995	unsigned long flags;
996
997	spin_lock_irqsave(&si->scsi_queue_lock, flags);
998restart:
999	list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
1000		sc_cmd = fsp->cmd;
1001		if (id != -1 && scmd_id(sc_cmd) != id)
1002			continue;
1003
1004		if (lun != -1 && sc_cmd->device->lun != lun)
1005			continue;
1006
1007		fc_fcp_pkt_hold(fsp);
1008		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1009
1010		if (!fc_fcp_lock_pkt(fsp)) {
1011			fc_fcp_cleanup_cmd(fsp, error);
1012			fc_io_compl(fsp);
1013			fc_fcp_unlock_pkt(fsp);
1014		}
1015
1016		fc_fcp_pkt_release(fsp);
1017		spin_lock_irqsave(&si->scsi_queue_lock, flags);
1018		/*
1019		 * while we dropped the lock multiple pkts could
1020		 * have been released, so we have to start over.
1021		 */
1022		goto restart;
1023	}
1024	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1025}
1026
1027/**
1028 * fc_fcp_abort_io() - Abort all FCP-SCSI exchanges on a local port
1029 * @lport: The local port whose exchanges are to be aborted
1030 */
1031static void fc_fcp_abort_io(struct fc_lport *lport)
1032{
1033	fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_HRD_ERROR);
1034}
1035
1036/**
1037 * fc_fcp_pkt_send() - Send a fcp_pkt
1038 * @lport: The local port to send the FCP packet on
1039 * @fsp:   The FCP packet to send
1040 *
1041 * Return:  Zero for success and -1 for failure
1042 * Locks:   Called without locks held
1043 */
1044static int fc_fcp_pkt_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp)
1045{
1046	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1047	unsigned long flags;
1048	int rc;
1049
1050	fsp->cmd->SCp.ptr = (char *)fsp;
1051	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1052	fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
1053
1054	int_to_scsilun(fsp->cmd->device->lun,
1055		       (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
1056	memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
1057
1058	spin_lock_irqsave(&si->scsi_queue_lock, flags);
1059	list_add_tail(&fsp->list, &si->scsi_pkt_queue);
1060	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1061	rc = lport->tt.fcp_cmd_send(lport, fsp, fc_fcp_recv);
1062	if (unlikely(rc)) {
1063		spin_lock_irqsave(&si->scsi_queue_lock, flags);
1064		list_del(&fsp->list);
1065		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1066	}
1067
1068	return rc;
1069}
1070
1071/**
1072 * fc_fcp_cmd_send() - Send a FCP command
1073 * @lport: The local port to send the command on
1074 * @fsp:   The FCP packet the command is on
1075 * @resp:  The handler for the response
1076 */
1077static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1078			   void (*resp)(struct fc_seq *,
1079					struct fc_frame *fp,
1080					void *arg))
1081{
1082	struct fc_frame *fp;
1083	struct fc_seq *seq;
1084	struct fc_rport *rport;
1085	struct fc_rport_libfc_priv *rpriv;
1086	const size_t len = sizeof(fsp->cdb_cmd);
1087	int rc = 0;
1088
1089	if (fc_fcp_lock_pkt(fsp))
1090		return 0;
1091
1092	fp = fc_fcp_frame_alloc(lport, sizeof(fsp->cdb_cmd));
1093	if (!fp) {
1094		rc = -1;
1095		goto unlock;
1096	}
1097
1098	memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
1099	fr_fsp(fp) = fsp;
1100	rport = fsp->rport;
1101	fsp->max_payload = rport->maxframe_size;
1102	rpriv = rport->dd_data;
1103
1104	fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
1105		       rpriv->local_port->port_id, FC_TYPE_FCP,
1106		       FC_FCTL_REQ, 0);
1107
1108	seq = lport->tt.exch_seq_send(lport, fp, resp, fc_fcp_pkt_destroy,
1109				      fsp, 0);
1110	if (!seq) {
1111		rc = -1;
1112		goto unlock;
1113	}
1114	fsp->last_pkt_time = jiffies;
1115	fsp->seq_ptr = seq;
1116	fc_fcp_pkt_hold(fsp);	/* hold for fc_fcp_pkt_destroy */
1117
1118	setup_timer(&fsp->timer, fc_fcp_timeout, (unsigned long)fsp);
1119	fc_fcp_timer_set(fsp,
1120			 (fsp->tgt_flags & FC_RP_FLAGS_REC_SUPPORTED) ?
1121			 FC_SCSI_REC_TOV : FC_SCSI_ER_TIMEOUT);
1122unlock:
1123	fc_fcp_unlock_pkt(fsp);
1124	return rc;
1125}
1126
1127/**
1128 * fc_fcp_error() - Handler for FCP layer errors
1129 * @fsp: The FCP packet the error is on
1130 * @fp:	 The frame that has errored
1131 */
1132static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1133{
1134	int error = PTR_ERR(fp);
1135
1136	if (fc_fcp_lock_pkt(fsp))
1137		return;
1138
1139	if (error == -FC_EX_CLOSED) {
1140		fc_fcp_retry_cmd(fsp);
1141		goto unlock;
1142	}
1143
1144	/*
1145	 * clear abort pending, because the lower layer
1146	 * decided to force completion.
1147	 */
1148	fsp->state &= ~FC_SRB_ABORT_PENDING;
1149	fsp->status_code = FC_CMD_PLOGO;
1150	fc_fcp_complete_locked(fsp);
1151unlock:
1152	fc_fcp_unlock_pkt(fsp);
1153}
1154
1155/**
1156 * fc_fcp_pkt_abort() - Abort a fcp_pkt
1157 * @fsp:   The FCP packet to abort on
1158 *
1159 * Called to send an abort and then wait for abort completion
1160 */
1161static int fc_fcp_pkt_abort(struct fc_fcp_pkt *fsp)
1162{
1163	int rc = FAILED;
1164
1165	if (fc_fcp_send_abort(fsp))
1166		return FAILED;
1167
1168	init_completion(&fsp->tm_done);
1169	fsp->wait_for_comp = 1;
1170
1171	spin_unlock_bh(&fsp->scsi_pkt_lock);
1172	rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1173	spin_lock_bh(&fsp->scsi_pkt_lock);
1174	fsp->wait_for_comp = 0;
1175
1176	if (!rc) {
1177		FC_FCP_DBG(fsp, "target abort cmd  failed\n");
1178		rc = FAILED;
1179	} else if (fsp->state & FC_SRB_ABORTED) {
1180		FC_FCP_DBG(fsp, "target abort cmd  passed\n");
1181		rc = SUCCESS;
1182		fc_fcp_complete_locked(fsp);
1183	}
1184
1185	return rc;
1186}
1187
1188/**
1189 * fc_lun_reset_send() - Send LUN reset command
1190 * @data: The FCP packet that identifies the LUN to be reset
1191 */
1192static void fc_lun_reset_send(unsigned long data)
1193{
1194	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1195	struct fc_lport *lport = fsp->lp;
1196	if (lport->tt.fcp_cmd_send(lport, fsp, fc_tm_done)) {
1197		if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
1198			return;
1199		if (fc_fcp_lock_pkt(fsp))
1200			return;
1201		setup_timer(&fsp->timer, fc_lun_reset_send, (unsigned long)fsp);
1202		fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1203		fc_fcp_unlock_pkt(fsp);
1204	}
1205}
1206
1207/**
1208 * fc_lun_reset() - Send a LUN RESET command to a device
1209 *		    and wait for the reply
1210 * @lport: The local port to sent the comand on
1211 * @fsp:   The FCP packet that identifies the LUN to be reset
1212 * @id:	   The SCSI command ID
1213 * @lun:   The LUN ID to be reset
1214 */
1215static int fc_lun_reset(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1216			unsigned int id, unsigned int lun)
1217{
1218	int rc;
1219
1220	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1221	fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
1222	int_to_scsilun(lun, (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
1223
1224	fsp->wait_for_comp = 1;
1225	init_completion(&fsp->tm_done);
1226
1227	fc_lun_reset_send((unsigned long)fsp);
1228
1229	/*
1230	 * wait for completion of reset
1231	 * after that make sure all commands are terminated
1232	 */
1233	rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1234
1235	spin_lock_bh(&fsp->scsi_pkt_lock);
1236	fsp->state |= FC_SRB_COMPL;
1237	spin_unlock_bh(&fsp->scsi_pkt_lock);
1238
1239	del_timer_sync(&fsp->timer);
1240
1241	spin_lock_bh(&fsp->scsi_pkt_lock);
1242	if (fsp->seq_ptr) {
1243		lport->tt.exch_done(fsp->seq_ptr);
1244		fsp->seq_ptr = NULL;
1245	}
1246	fsp->wait_for_comp = 0;
1247	spin_unlock_bh(&fsp->scsi_pkt_lock);
1248
1249	if (!rc) {
1250		FC_SCSI_DBG(lport, "lun reset failed\n");
1251		return FAILED;
1252	}
1253
1254	/* cdb_status holds the tmf's rsp code */
1255	if (fsp->cdb_status != FCP_TMF_CMPL)
1256		return FAILED;
1257
1258	FC_SCSI_DBG(lport, "lun reset to lun %u completed\n", lun);
1259	fc_fcp_cleanup_each_cmd(lport, id, lun, FC_CMD_ABORTED);
1260	return SUCCESS;
1261}
1262
1263/**
1264 * fc_tm_done() - Task Managment response handler
1265 * @seq: The sequence that the response is on
1266 * @fp:	 The response frame
1267 * @arg: The FCP packet the response is for
1268 */
1269static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1270{
1271	struct fc_fcp_pkt *fsp = arg;
1272	struct fc_frame_header *fh;
1273
1274	if (IS_ERR(fp)) {
1275		/*
1276		 * If there is an error just let it timeout or wait
1277		 * for TMF to be aborted if it timedout.
1278		 *
1279		 * scsi-eh will escalate for when either happens.
1280		 */
1281		return;
1282	}
1283
1284	if (fc_fcp_lock_pkt(fsp))
1285		return;
1286
1287	/*
1288	 * raced with eh timeout handler.
1289	 */
1290	if (!fsp->seq_ptr || !fsp->wait_for_comp) {
1291		spin_unlock_bh(&fsp->scsi_pkt_lock);
1292		return;
1293	}
1294
1295	fh = fc_frame_header_get(fp);
1296	if (fh->fh_type != FC_TYPE_BLS)
1297		fc_fcp_resp(fsp, fp);
1298	fsp->seq_ptr = NULL;
1299	fsp->lp->tt.exch_done(seq);
1300	fc_frame_free(fp);
1301	fc_fcp_unlock_pkt(fsp);
1302}
1303
1304/**
1305 * fc_fcp_cleanup() - Cleanup all FCP exchanges on a local port
1306 * @lport: The local port to be cleaned up
1307 */
1308static void fc_fcp_cleanup(struct fc_lport *lport)
1309{
1310	fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_ERROR);
1311}
1312
1313/**
1314 * fc_fcp_timeout() - Handler for fcp_pkt timeouts
1315 * @data: The FCP packet that has timed out
1316 *
1317 * If REC is supported then just issue it and return. The REC exchange will
1318 * complete or time out and recovery can continue at that point. Otherwise,
1319 * if the response has been received without all the data it has been
1320 * ER_TIMEOUT since the response was received. If the response has not been
1321 * received we see if data was received recently. If it has been then we
1322 * continue waiting, otherwise, we abort the command.
1323 */
1324static void fc_fcp_timeout(unsigned long data)
1325{
1326	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1327	struct fc_rport *rport = fsp->rport;
1328	struct fc_rport_libfc_priv *rpriv = rport->dd_data;
1329
1330	if (fc_fcp_lock_pkt(fsp))
1331		return;
1332
1333	if (fsp->cdb_cmd.fc_tm_flags)
1334		goto unlock;
1335
1336	fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
1337
1338	if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1339		fc_fcp_rec(fsp);
1340	else if (time_after_eq(fsp->last_pkt_time + (FC_SCSI_ER_TIMEOUT / 2),
1341			       jiffies))
1342		fc_fcp_timer_set(fsp, FC_SCSI_ER_TIMEOUT);
1343	else if (fsp->state & FC_SRB_RCV_STATUS)
1344		fc_fcp_complete_locked(fsp);
1345	else
1346		fc_fcp_recovery(fsp);
1347	fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
1348unlock:
1349	fc_fcp_unlock_pkt(fsp);
1350}
1351
1352/**
1353 * fc_fcp_rec() - Send a REC ELS request
1354 * @fsp: The FCP packet to send the REC request on
1355 */
1356static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
1357{
1358	struct fc_lport *lport;
1359	struct fc_frame *fp;
1360	struct fc_rport *rport;
1361	struct fc_rport_libfc_priv *rpriv;
1362
1363	lport = fsp->lp;
1364	rport = fsp->rport;
1365	rpriv = rport->dd_data;
1366	if (!fsp->seq_ptr || rpriv->rp_state != RPORT_ST_READY) {
1367		fsp->status_code = FC_HRD_ERROR;
1368		fsp->io_status = 0;
1369		fc_fcp_complete_locked(fsp);
1370		return;
1371	}
1372	fp = fc_fcp_frame_alloc(lport, sizeof(struct fc_els_rec));
1373	if (!fp)
1374		goto retry;
1375
1376	fr_seq(fp) = fsp->seq_ptr;
1377	fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
1378		       rpriv->local_port->port_id, FC_TYPE_ELS,
1379		       FC_FCTL_REQ, 0);
1380	if (lport->tt.elsct_send(lport, rport->port_id, fp, ELS_REC,
1381				 fc_fcp_rec_resp, fsp,
1382				 jiffies_to_msecs(FC_SCSI_REC_TOV))) {
1383		fc_fcp_pkt_hold(fsp);		/* hold while REC outstanding */
1384		return;
1385	}
1386retry:
1387	if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1388		fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1389	else
1390		fc_fcp_recovery(fsp);
1391}
1392
1393/**
1394 * fc_fcp_rec_resp() - Handler for REC ELS responses
1395 * @seq: The sequence the response is on
1396 * @fp:	 The response frame
1397 * @arg: The FCP packet the response is on
1398 *
1399 * If the response is a reject then the scsi layer will handle
1400 * the timeout. If the response is a LS_ACC then if the I/O was not completed
1401 * set the timeout and return. If the I/O was completed then complete the
1402 * exchange and tell the SCSI layer.
1403 */
1404static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1405{
1406	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
1407	struct fc_els_rec_acc *recp;
1408	struct fc_els_ls_rjt *rjt;
1409	u32 e_stat;
1410	u8 opcode;
1411	u32 offset;
1412	enum dma_data_direction data_dir;
1413	enum fc_rctl r_ctl;
1414	struct fc_rport_libfc_priv *rpriv;
1415
1416	if (IS_ERR(fp)) {
1417		fc_fcp_rec_error(fsp, fp);
1418		return;
1419	}
1420
1421	if (fc_fcp_lock_pkt(fsp))
1422		goto out;
1423
1424	fsp->recov_retry = 0;
1425	opcode = fc_frame_payload_op(fp);
1426	if (opcode == ELS_LS_RJT) {
1427		rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1428		switch (rjt->er_reason) {
1429		default:
1430			FC_FCP_DBG(fsp, "device %x unexpected REC reject "
1431				   "reason %d expl %d\n",
1432				   fsp->rport->port_id, rjt->er_reason,
1433				   rjt->er_explan);
1434			/* fall through */
1435		case ELS_RJT_UNSUP:
1436			FC_FCP_DBG(fsp, "device does not support REC\n");
1437			rpriv = fsp->rport->dd_data;
1438			/*
1439			 * if we do not spport RECs or got some bogus
1440			 * reason then resetup timer so we check for
1441			 * making progress.
1442			 */
1443			rpriv->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
1444			fc_fcp_timer_set(fsp, FC_SCSI_ER_TIMEOUT);
1445			break;
1446		case ELS_RJT_LOGIC:
1447		case ELS_RJT_UNAB:
1448			/*
1449			 * If no data transfer, the command frame got dropped
1450			 * so we just retry.  If data was transferred, we
1451			 * lost the response but the target has no record,
1452			 * so we abort and retry.
1453			 */
1454			if (rjt->er_explan == ELS_EXPL_OXID_RXID &&
1455			    fsp->xfer_len == 0) {
1456				fc_fcp_retry_cmd(fsp);
1457				break;
1458			}
1459			fc_fcp_recovery(fsp);
1460			break;
1461		}
1462	} else if (opcode == ELS_LS_ACC) {
1463		if (fsp->state & FC_SRB_ABORTED)
1464			goto unlock_out;
1465
1466		data_dir = fsp->cmd->sc_data_direction;
1467		recp = fc_frame_payload_get(fp, sizeof(*recp));
1468		offset = ntohl(recp->reca_fc4value);
1469		e_stat = ntohl(recp->reca_e_stat);
1470
1471		if (e_stat & ESB_ST_COMPLETE) {
1472
1473			/*
1474			 * The exchange is complete.
1475			 *
1476			 * For output, we must've lost the response.
1477			 * For input, all data must've been sent.
1478			 * We lost may have lost the response
1479			 * (and a confirmation was requested) and maybe
1480			 * some data.
1481			 *
1482			 * If all data received, send SRR
1483			 * asking for response.	 If partial data received,
1484			 * or gaps, SRR requests data at start of gap.
1485			 * Recovery via SRR relies on in-order-delivery.
1486			 */
1487			if (data_dir == DMA_TO_DEVICE) {
1488				r_ctl = FC_RCTL_DD_CMD_STATUS;
1489			} else if (fsp->xfer_contig_end == offset) {
1490				r_ctl = FC_RCTL_DD_CMD_STATUS;
1491			} else {
1492				offset = fsp->xfer_contig_end;
1493				r_ctl = FC_RCTL_DD_SOL_DATA;
1494			}
1495			fc_fcp_srr(fsp, r_ctl, offset);
1496		} else if (e_stat & ESB_ST_SEQ_INIT) {
1497
1498			/*
1499			 * The remote port has the initiative, so just
1500			 * keep waiting for it to complete.
1501			 */
1502			fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1503		} else {
1504
1505			/*
1506			 * The exchange is incomplete, we have seq. initiative.
1507			 * Lost response with requested confirmation,
1508			 * lost confirmation, lost transfer ready or
1509			 * lost write data.
1510			 *
1511			 * For output, if not all data was received, ask
1512			 * for transfer ready to be repeated.
1513			 *
1514			 * If we received or sent all the data, send SRR to
1515			 * request response.
1516			 *
1517			 * If we lost a response, we may have lost some read
1518			 * data as well.
1519			 */
1520			r_ctl = FC_RCTL_DD_SOL_DATA;
1521			if (data_dir == DMA_TO_DEVICE) {
1522				r_ctl = FC_RCTL_DD_CMD_STATUS;
1523				if (offset < fsp->data_len)
1524					r_ctl = FC_RCTL_DD_DATA_DESC;
1525			} else if (offset == fsp->xfer_contig_end) {
1526				r_ctl = FC_RCTL_DD_CMD_STATUS;
1527			} else if (fsp->xfer_contig_end < offset) {
1528				offset = fsp->xfer_contig_end;
1529			}
1530			fc_fcp_srr(fsp, r_ctl, offset);
1531		}
1532	}
1533unlock_out:
1534	fc_fcp_unlock_pkt(fsp);
1535out:
1536	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
1537	fc_frame_free(fp);
1538}
1539
1540/**
1541 * fc_fcp_rec_error() - Handler for REC errors
1542 * @fsp: The FCP packet the error is on
1543 * @fp:	 The REC frame
1544 */
1545static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1546{
1547	int error = PTR_ERR(fp);
1548
1549	if (fc_fcp_lock_pkt(fsp))
1550		goto out;
1551
1552	switch (error) {
1553	case -FC_EX_CLOSED:
1554		fc_fcp_retry_cmd(fsp);
1555		break;
1556
1557	default:
1558		FC_FCP_DBG(fsp, "REC %p fid %6.6x error unexpected error %d\n",
1559			   fsp, fsp->rport->port_id, error);
1560		fsp->status_code = FC_CMD_PLOGO;
1561		/* fall through */
1562
1563	case -FC_EX_TIMEOUT:
1564		/*
1565		 * Assume REC or LS_ACC was lost.
1566		 * The exchange manager will have aborted REC, so retry.
1567		 */
1568		FC_FCP_DBG(fsp, "REC fid %6.6x error error %d retry %d/%d\n",
1569			   fsp->rport->port_id, error, fsp->recov_retry,
1570			   FC_MAX_RECOV_RETRY);
1571		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1572			fc_fcp_rec(fsp);
1573		else
1574			fc_fcp_recovery(fsp);
1575		break;
1576	}
1577	fc_fcp_unlock_pkt(fsp);
1578out:
1579	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
1580}
1581
1582/**
1583 * fc_fcp_recovery() - Handler for fcp_pkt recovery
1584 * @fsp: The FCP pkt that needs to be aborted
1585 */
1586static void fc_fcp_recovery(struct fc_fcp_pkt *fsp)
1587{
1588	fsp->status_code = FC_CMD_RECOVERY;
1589	fsp->cdb_status = 0;
1590	fsp->io_status = 0;
1591	/*
1592	 * if this fails then we let the scsi command timer fire and
1593	 * scsi-ml escalate.
1594	 */
1595	fc_fcp_send_abort(fsp);
1596}
1597
1598/**
1599 * fc_fcp_srr() - Send a SRR request (Sequence Retransmission Request)
1600 * @fsp:   The FCP packet the SRR is to be sent on
1601 * @r_ctl: The R_CTL field for the SRR request
1602 * This is called after receiving status but insufficient data, or
1603 * when expecting status but the request has timed out.
1604 */
1605static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
1606{
1607	struct fc_lport *lport = fsp->lp;
1608	struct fc_rport *rport;
1609	struct fc_rport_libfc_priv *rpriv;
1610	struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1611	struct fc_seq *seq;
1612	struct fcp_srr *srr;
1613	struct fc_frame *fp;
1614	u8 cdb_op;
1615
1616	rport = fsp->rport;
1617	rpriv = rport->dd_data;
1618	cdb_op = fsp->cdb_cmd.fc_cdb[0];
1619
1620	if (!(rpriv->flags & FC_RP_FLAGS_RETRY) ||
1621	    rpriv->rp_state != RPORT_ST_READY)
1622		goto retry;			/* shouldn't happen */
1623	fp = fc_fcp_frame_alloc(lport, sizeof(*srr));
1624	if (!fp)
1625		goto retry;
1626
1627	srr = fc_frame_payload_get(fp, sizeof(*srr));
1628	memset(srr, 0, sizeof(*srr));
1629	srr->srr_op = ELS_SRR;
1630	srr->srr_ox_id = htons(ep->oxid);
1631	srr->srr_rx_id = htons(ep->rxid);
1632	srr->srr_r_ctl = r_ctl;
1633	srr->srr_rel_off = htonl(offset);
1634
1635	fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
1636		       rpriv->local_port->port_id, FC_TYPE_FCP,
1637		       FC_FCTL_REQ, 0);
1638
1639	seq = lport->tt.exch_seq_send(lport, fp, fc_fcp_srr_resp, NULL,
1640				      fsp, jiffies_to_msecs(FC_SCSI_REC_TOV));
1641	if (!seq)
1642		goto retry;
1643
1644	fsp->recov_seq = seq;
1645	fsp->xfer_len = offset;
1646	fsp->xfer_contig_end = offset;
1647	fsp->state &= ~FC_SRB_RCV_STATUS;
1648	fc_fcp_pkt_hold(fsp);		/* hold for outstanding SRR */
1649	return;
1650retry:
1651	fc_fcp_retry_cmd(fsp);
1652}
1653
1654/**
1655 * fc_fcp_srr_resp() - Handler for SRR response
1656 * @seq: The sequence the SRR is on
1657 * @fp:	 The SRR frame
1658 * @arg: The FCP packet the SRR is on
1659 */
1660static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1661{
1662	struct fc_fcp_pkt *fsp = arg;
1663	struct fc_frame_header *fh;
1664
1665	if (IS_ERR(fp)) {
1666		fc_fcp_srr_error(fsp, fp);
1667		return;
1668	}
1669
1670	if (fc_fcp_lock_pkt(fsp))
1671		goto out;
1672
1673	fh = fc_frame_header_get(fp);
1674	/*
1675	 * BUG? fc_fcp_srr_error calls exch_done which would release
1676	 * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
1677	 * then fc_exch_timeout would be sending an abort. The exch_done
1678	 * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
1679	 * an abort response though.
1680	 */
1681	if (fh->fh_type == FC_TYPE_BLS) {
1682		fc_fcp_unlock_pkt(fsp);
1683		return;
1684	}
1685
1686	fsp->recov_seq = NULL;
1687	switch (fc_frame_payload_op(fp)) {
1688	case ELS_LS_ACC:
1689		fsp->recov_retry = 0;
1690		fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1691		break;
1692	case ELS_LS_RJT:
1693	default:
1694		fc_fcp_recovery(fsp);
1695		break;
1696	}
1697	fc_fcp_unlock_pkt(fsp);
1698	fsp->lp->tt.exch_done(seq);
1699out:
1700	fc_frame_free(fp);
1701	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding SRR */
1702}
1703
1704/**
1705 * fc_fcp_srr_error() - Handler for SRR errors
1706 * @fsp: The FCP packet that the SRR error is on
1707 * @fp:	 The SRR frame
1708 */
1709static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1710{
1711	if (fc_fcp_lock_pkt(fsp))
1712		goto out;
1713	fsp->lp->tt.exch_done(fsp->recov_seq);
1714	fsp->recov_seq = NULL;
1715	switch (PTR_ERR(fp)) {
1716	case -FC_EX_TIMEOUT:
1717		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1718			fc_fcp_rec(fsp);
1719		else
1720			fc_fcp_recovery(fsp);
1721		break;
1722	case -FC_EX_CLOSED:			/* e.g., link failure */
1723		/* fall through */
1724	default:
1725		fc_fcp_retry_cmd(fsp);
1726		break;
1727	}
1728	fc_fcp_unlock_pkt(fsp);
1729out:
1730	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding SRR */
1731}
1732
1733/**
1734 * fc_fcp_lport_queue_ready() - Determine if the lport and it's queue is ready
1735 * @lport: The local port to be checked
1736 */
1737static inline int fc_fcp_lport_queue_ready(struct fc_lport *lport)
1738{
1739	/* lock ? */
1740	return (lport->state == LPORT_ST_READY) &&
1741		lport->link_up && !lport->qfull;
1742}
1743
1744/**
1745 * fc_queuecommand() - The queuecommand function of the SCSI template
1746 * @cmd:   The scsi_cmnd to be executed
1747 * @done:  The callback function to be called when the scsi_cmnd is complete
1748 *
1749 * This is the i/o strategy routine, called by the SCSI layer. This routine
1750 * is called with the host_lock held.
1751 */
1752int fc_queuecommand(struct scsi_cmnd *sc_cmd, void (*done)(struct scsi_cmnd *))
1753{
1754	struct fc_lport *lport;
1755	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1756	struct fc_fcp_pkt *fsp;
1757	struct fc_rport_libfc_priv *rpriv;
1758	int rval;
1759	int rc = 0;
1760	struct fcoe_dev_stats *stats;
1761
1762	lport = shost_priv(sc_cmd->device->host);
1763
1764	rval = fc_remote_port_chkready(rport);
1765	if (rval) {
1766		sc_cmd->result = rval;
1767		done(sc_cmd);
1768		return 0;
1769	}
1770	spin_unlock_irq(lport->host->host_lock);
1771
1772	if (!*(struct fc_remote_port **)rport->dd_data) {
1773		/*
1774		 * rport is transitioning from blocked/deleted to
1775		 * online
1776		 */
1777		sc_cmd->result = DID_IMM_RETRY << 16;
1778		done(sc_cmd);
1779		goto out;
1780	}
1781
1782	rpriv = rport->dd_data;
1783
1784	if (!fc_fcp_lport_queue_ready(lport)) {
1785		if (lport->qfull)
1786			fc_fcp_can_queue_ramp_down(lport);
1787		rc = SCSI_MLQUEUE_HOST_BUSY;
1788		goto out;
1789	}
1790
1791	fsp = fc_fcp_pkt_alloc(lport, GFP_ATOMIC);
1792	if (fsp == NULL) {
1793		rc = SCSI_MLQUEUE_HOST_BUSY;
1794		goto out;
1795	}
1796
1797	/*
1798	 * build the libfc request pkt
1799	 */
1800	fsp->cmd = sc_cmd;	/* save the cmd */
1801	fsp->lp = lport;	/* save the softc ptr */
1802	fsp->rport = rport;	/* set the remote port ptr */
1803	fsp->xfer_ddp = FC_XID_UNKNOWN;
1804	sc_cmd->scsi_done = done;
1805
1806	/*
1807	 * set up the transfer length
1808	 */
1809	fsp->data_len = scsi_bufflen(sc_cmd);
1810	fsp->xfer_len = 0;
1811
1812	/*
1813	 * setup the data direction
1814	 */
1815	stats = per_cpu_ptr(lport->dev_stats, get_cpu());
1816	if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
1817		fsp->req_flags = FC_SRB_READ;
1818		stats->InputRequests++;
1819		stats->InputMegabytes = fsp->data_len;
1820	} else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
1821		fsp->req_flags = FC_SRB_WRITE;
1822		stats->OutputRequests++;
1823		stats->OutputMegabytes = fsp->data_len;
1824	} else {
1825		fsp->req_flags = 0;
1826		stats->ControlRequests++;
1827	}
1828	put_cpu();
1829
1830	fsp->tgt_flags = rpriv->flags;
1831
1832	init_timer(&fsp->timer);
1833	fsp->timer.data = (unsigned long)fsp;
1834
1835	/*
1836	 * send it to the lower layer
1837	 * if we get -1 return then put the request in the pending
1838	 * queue.
1839	 */
1840	rval = fc_fcp_pkt_send(lport, fsp);
1841	if (rval != 0) {
1842		fsp->state = FC_SRB_FREE;
1843		fc_fcp_pkt_release(fsp);
1844		rc = SCSI_MLQUEUE_HOST_BUSY;
1845	}
1846out:
1847	spin_lock_irq(lport->host->host_lock);
1848	return rc;
1849}
1850EXPORT_SYMBOL(fc_queuecommand);
1851
1852/**
1853 * fc_io_compl() - Handle responses for completed commands
1854 * @fsp: The FCP packet that is complete
1855 *
1856 * Translates fcp_pkt errors to a Linux SCSI errors.
1857 * The fcp packet lock must be held when calling.
1858 */
1859static void fc_io_compl(struct fc_fcp_pkt *fsp)
1860{
1861	struct fc_fcp_internal *si;
1862	struct scsi_cmnd *sc_cmd;
1863	struct fc_lport *lport;
1864	unsigned long flags;
1865
1866	/* release outstanding ddp context */
1867	fc_fcp_ddp_done(fsp);
1868
1869	fsp->state |= FC_SRB_COMPL;
1870	if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
1871		spin_unlock_bh(&fsp->scsi_pkt_lock);
1872		del_timer_sync(&fsp->timer);
1873		spin_lock_bh(&fsp->scsi_pkt_lock);
1874	}
1875
1876	lport = fsp->lp;
1877	si = fc_get_scsi_internal(lport);
1878	if (!fsp->cmd)
1879		return;
1880
1881	/*
1882	 * if can_queue ramp down is done then try can_queue ramp up
1883	 * since commands are completing now.
1884	 */
1885	if (si->last_can_queue_ramp_down_time)
1886		fc_fcp_can_queue_ramp_up(lport);
1887
1888	sc_cmd = fsp->cmd;
1889	fsp->cmd = NULL;
1890
1891	if (!sc_cmd->SCp.ptr)
1892		return;
1893
1894	CMD_SCSI_STATUS(sc_cmd) = fsp->cdb_status;
1895	switch (fsp->status_code) {
1896	case FC_COMPLETE:
1897		if (fsp->cdb_status == 0) {
1898			/*
1899			 * good I/O status
1900			 */
1901			sc_cmd->result = DID_OK << 16;
1902			if (fsp->scsi_resid)
1903				CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1904		} else {
1905			/*
1906			 * transport level I/O was ok but scsi
1907			 * has non zero status
1908			 */
1909			sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
1910		}
1911		break;
1912	case FC_ERROR:
1913		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1914			   "due to FC_ERROR\n");
1915		sc_cmd->result = DID_ERROR << 16;
1916		break;
1917	case FC_DATA_UNDRUN:
1918		if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) {
1919			/*
1920			 * scsi status is good but transport level
1921			 * underrun.
1922			 */
1923			if (fsp->state & FC_SRB_RCV_STATUS) {
1924				sc_cmd->result = DID_OK << 16;
1925			} else {
1926				FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml"
1927					   " due to FC_DATA_UNDRUN (trans)\n");
1928				sc_cmd->result = DID_ERROR << 16;
1929			}
1930		} else {
1931			/*
1932			 * scsi got underrun, this is an error
1933			 */
1934			FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1935				   "due to FC_DATA_UNDRUN (scsi)\n");
1936			CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1937			sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1938		}
1939		break;
1940	case FC_DATA_OVRRUN:
1941		/*
1942		 * overrun is an error
1943		 */
1944		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1945			   "due to FC_DATA_OVRRUN\n");
1946		sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1947		break;
1948	case FC_CMD_ABORTED:
1949		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1950			   "due to FC_CMD_ABORTED\n");
1951		sc_cmd->result = (DID_ERROR << 16) | fsp->io_status;
1952		break;
1953	case FC_CMD_RECOVERY:
1954		sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
1955		break;
1956	case FC_CMD_RESET:
1957		sc_cmd->result = (DID_RESET << 16);
1958		break;
1959	case FC_HRD_ERROR:
1960		sc_cmd->result = (DID_NO_CONNECT << 16);
1961		break;
1962	default:
1963		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1964			   "due to unknown error\n");
1965		sc_cmd->result = (DID_ERROR << 16);
1966		break;
1967	}
1968
1969	if (lport->state != LPORT_ST_READY && fsp->status_code != FC_COMPLETE) {
1970		sc_cmd->result = (DID_REQUEUE << 16);
1971		FC_FCP_DBG(fsp, "Returning DID_REQUEUE to scsi-ml\n");
1972	}
1973
1974	spin_lock_irqsave(&si->scsi_queue_lock, flags);
1975	list_del(&fsp->list);
1976	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1977	sc_cmd->SCp.ptr = NULL;
1978	sc_cmd->scsi_done(sc_cmd);
1979
1980	/* release ref from initial allocation in queue command */
1981	fc_fcp_pkt_release(fsp);
1982}
1983
1984/**
1985 * fc_eh_abort() - Abort a command
1986 * @sc_cmd: The SCSI command to abort
1987 *
1988 * From SCSI host template.
1989 * Send an ABTS to the target device and wait for the response.
1990 */
1991int fc_eh_abort(struct scsi_cmnd *sc_cmd)
1992{
1993	struct fc_fcp_pkt *fsp;
1994	struct fc_lport *lport;
1995	int rc = FAILED;
1996	unsigned long flags;
1997
1998	lport = shost_priv(sc_cmd->device->host);
1999	if (lport->state != LPORT_ST_READY)
2000		return rc;
2001	else if (!lport->link_up)
2002		return rc;
2003
2004	spin_lock_irqsave(lport->host->host_lock, flags);
2005	fsp = CMD_SP(sc_cmd);
2006	if (!fsp) {
2007		/* command completed while scsi eh was setting up */
2008		spin_unlock_irqrestore(lport->host->host_lock, flags);
2009		return SUCCESS;
2010	}
2011	/* grab a ref so the fsp and sc_cmd cannot be relased from under us */
2012	fc_fcp_pkt_hold(fsp);
2013	spin_unlock_irqrestore(lport->host->host_lock, flags);
2014
2015	if (fc_fcp_lock_pkt(fsp)) {
2016		/* completed while we were waiting for timer to be deleted */
2017		rc = SUCCESS;
2018		goto release_pkt;
2019	}
2020
2021	rc = fc_fcp_pkt_abort(fsp);
2022	fc_fcp_unlock_pkt(fsp);
2023
2024release_pkt:
2025	fc_fcp_pkt_release(fsp);
2026	return rc;
2027}
2028EXPORT_SYMBOL(fc_eh_abort);
2029
2030/**
2031 * fc_eh_device_reset() - Reset a single LUN
2032 * @sc_cmd: The SCSI command which identifies the device whose
2033 *	    LUN is to be reset
2034 *
2035 * Set from SCSI host template.
2036 */
2037int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
2038{
2039	struct fc_lport *lport;
2040	struct fc_fcp_pkt *fsp;
2041	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
2042	int rc = FAILED;
2043	int rval;
2044
2045	rval = fc_remote_port_chkready(rport);
2046	if (rval)
2047		goto out;
2048
2049	lport = shost_priv(sc_cmd->device->host);
2050
2051	if (lport->state != LPORT_ST_READY)
2052		return rc;
2053
2054	FC_SCSI_DBG(lport, "Resetting rport (%6.6x)\n", rport->port_id);
2055
2056	fsp = fc_fcp_pkt_alloc(lport, GFP_NOIO);
2057	if (fsp == NULL) {
2058		printk(KERN_WARNING "libfc: could not allocate scsi_pkt\n");
2059		goto out;
2060	}
2061
2062	/*
2063	 * Build the libfc request pkt. Do not set the scsi cmnd, because
2064	 * the sc passed in is not setup for execution like when sent
2065	 * through the queuecommand callout.
2066	 */
2067	fsp->lp = lport;	/* save the softc ptr */
2068	fsp->rport = rport;	/* set the remote port ptr */
2069
2070	/*
2071	 * flush outstanding commands
2072	 */
2073	rc = fc_lun_reset(lport, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
2074	fsp->state = FC_SRB_FREE;
2075	fc_fcp_pkt_release(fsp);
2076
2077out:
2078	return rc;
2079}
2080EXPORT_SYMBOL(fc_eh_device_reset);
2081
2082/**
2083 * fc_eh_host_reset() - Reset a Scsi_Host.
2084 * @sc_cmd: The SCSI command that identifies the SCSI host to be reset
2085 */
2086int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
2087{
2088	struct Scsi_Host *shost = sc_cmd->device->host;
2089	struct fc_lport *lport = shost_priv(shost);
2090	unsigned long wait_tmo;
2091
2092	FC_SCSI_DBG(lport, "Resetting host\n");
2093
2094	lport->tt.lport_reset(lport);
2095	wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
2096	while (!fc_fcp_lport_queue_ready(lport) && time_before(jiffies,
2097							       wait_tmo))
2098		msleep(1000);
2099
2100	if (fc_fcp_lport_queue_ready(lport)) {
2101		shost_printk(KERN_INFO, shost, "libfc: Host reset succeeded "
2102			     "on port (%6.6x)\n", lport->port_id);
2103		return SUCCESS;
2104	} else {
2105		shost_printk(KERN_INFO, shost, "libfc: Host reset failed, "
2106			     "port (%6.6x) is not ready.\n",
2107			     lport->port_id);
2108		return FAILED;
2109	}
2110}
2111EXPORT_SYMBOL(fc_eh_host_reset);
2112
2113/**
2114 * fc_slave_alloc() - Configure the queue depth of a Scsi_Host
2115 * @sdev: The SCSI device that identifies the SCSI host
2116 *
2117 * Configures queue depth based on host's cmd_per_len. If not set
2118 * then we use the libfc default.
2119 */
2120int fc_slave_alloc(struct scsi_device *sdev)
2121{
2122	struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
2123
2124	if (!rport || fc_remote_port_chkready(rport))
2125		return -ENXIO;
2126
2127	if (sdev->tagged_supported)
2128		scsi_activate_tcq(sdev, FC_FCP_DFLT_QUEUE_DEPTH);
2129	else
2130		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev),
2131					FC_FCP_DFLT_QUEUE_DEPTH);
2132
2133	return 0;
2134}
2135EXPORT_SYMBOL(fc_slave_alloc);
2136
2137/**
2138 * fc_change_queue_depth() - Change a device's queue depth
2139 * @sdev:   The SCSI device whose queue depth is to change
2140 * @qdepth: The new queue depth
2141 * @reason: The resason for the change
2142 */
2143int fc_change_queue_depth(struct scsi_device *sdev, int qdepth, int reason)
2144{
2145	switch (reason) {
2146	case SCSI_QDEPTH_DEFAULT:
2147		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);
2148		break;
2149	case SCSI_QDEPTH_QFULL:
2150		scsi_track_queue_full(sdev, qdepth);
2151		break;
2152	case SCSI_QDEPTH_RAMP_UP:
2153		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);
2154		break;
2155	default:
2156		return -EOPNOTSUPP;
2157	}
2158	return sdev->queue_depth;
2159}
2160EXPORT_SYMBOL(fc_change_queue_depth);
2161
2162/**
2163 * fc_change_queue_type() - Change a device's queue type
2164 * @sdev:     The SCSI device whose queue depth is to change
2165 * @tag_type: Identifier for queue type
2166 */
2167int fc_change_queue_type(struct scsi_device *sdev, int tag_type)
2168{
2169	if (sdev->tagged_supported) {
2170		scsi_set_tag_type(sdev, tag_type);
2171		if (tag_type)
2172			scsi_activate_tcq(sdev, sdev->queue_depth);
2173		else
2174			scsi_deactivate_tcq(sdev, sdev->queue_depth);
2175	} else
2176		tag_type = 0;
2177
2178	return tag_type;
2179}
2180EXPORT_SYMBOL(fc_change_queue_type);
2181
2182/**
2183 * fc_fcp_destory() - Tear down the FCP layer for a given local port
2184 * @lport: The local port that no longer needs the FCP layer
2185 */
2186void fc_fcp_destroy(struct fc_lport *lport)
2187{
2188	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
2189
2190	if (!list_empty(&si->scsi_pkt_queue))
2191		printk(KERN_ERR "libfc: Leaked SCSI packets when destroying "
2192		       "port (%6.6x)\n", lport->port_id);
2193
2194	mempool_destroy(si->scsi_pkt_pool);
2195	kfree(si);
2196	lport->scsi_priv = NULL;
2197}
2198EXPORT_SYMBOL(fc_fcp_destroy);
2199
2200int fc_setup_fcp()
2201{
2202	int rc = 0;
2203
2204	scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
2205					    sizeof(struct fc_fcp_pkt),
2206					    0, SLAB_HWCACHE_ALIGN, NULL);
2207	if (!scsi_pkt_cachep) {
2208		printk(KERN_ERR "libfc: Unable to allocate SRB cache, "
2209		       "module load failed!");
2210		rc = -ENOMEM;
2211	}
2212
2213	return rc;
2214}
2215
2216void fc_destroy_fcp()
2217{
2218	if (scsi_pkt_cachep)
2219		kmem_cache_destroy(scsi_pkt_cachep);
2220}
2221
2222/**
2223 * fc_fcp_init() - Initialize the FCP layer for a local port
2224 * @lport: The local port to initialize the exchange layer for
2225 */
2226int fc_fcp_init(struct fc_lport *lport)
2227{
2228	int rc;
2229	struct fc_fcp_internal *si;
2230
2231	if (!lport->tt.fcp_cmd_send)
2232		lport->tt.fcp_cmd_send = fc_fcp_cmd_send;
2233
2234	if (!lport->tt.fcp_cleanup)
2235		lport->tt.fcp_cleanup = fc_fcp_cleanup;
2236
2237	if (!lport->tt.fcp_abort_io)
2238		lport->tt.fcp_abort_io = fc_fcp_abort_io;
2239
2240	si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
2241	if (!si)
2242		return -ENOMEM;
2243	lport->scsi_priv = si;
2244	si->max_can_queue = lport->host->can_queue;
2245	INIT_LIST_HEAD(&si->scsi_pkt_queue);
2246	spin_lock_init(&si->scsi_queue_lock);
2247
2248	si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
2249	if (!si->scsi_pkt_pool) {
2250		rc = -ENOMEM;
2251		goto free_internal;
2252	}
2253	return 0;
2254
2255free_internal:
2256	kfree(si);
2257	return rc;
2258}
2259EXPORT_SYMBOL(fc_fcp_init);
2260