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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
45static struct 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 scsi_pkt_queue lock
62 */
63#define CMD_SP(Cmnd)		    ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)
64#define CMD_ENTRY_STATUS(Cmnd)	    ((Cmnd)->SCp.have_data_in)
65#define CMD_COMPL_STATUS(Cmnd)	    ((Cmnd)->SCp.this_residual)
66#define CMD_SCSI_STATUS(Cmnd)	    ((Cmnd)->SCp.Status)
67#define CMD_RESID_LEN(Cmnd)	    ((Cmnd)->SCp.buffers_residual)
68
69/**
70 * struct fc_fcp_internal - FCP layer internal data
71 * @scsi_pkt_pool: Memory pool to draw FCP packets from
72 * @scsi_queue_lock: Protects the scsi_pkt_queue
73 * @scsi_pkt_queue: Current FCP packets
74 * @last_can_queue_ramp_down_time: ramp down time
75 * @last_can_queue_ramp_up_time: ramp up time
76 * @max_can_queue: max can_queue size
77 */
78struct fc_fcp_internal {
79	mempool_t		*scsi_pkt_pool;
80	spinlock_t		scsi_queue_lock;
81	struct list_head	scsi_pkt_queue;
82	unsigned long		last_can_queue_ramp_down_time;
83	unsigned long		last_can_queue_ramp_up_time;
84	int			max_can_queue;
85};
86
87#define fc_get_scsi_internal(x)	((struct fc_fcp_internal *)(x)->scsi_priv)
88
89/*
90 * function prototypes
91 * FC scsi I/O related functions
92 */
93static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
94static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
95static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
96static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
97static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
98static void fc_fcp_error(struct fc_fcp_pkt *, struct fc_frame *);
99static void fc_fcp_recovery(struct fc_fcp_pkt *, u8 code);
100static void fc_fcp_timeout(unsigned long);
101static void fc_fcp_rec(struct fc_fcp_pkt *);
102static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
103static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
104static void fc_io_compl(struct fc_fcp_pkt *);
105
106static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
107static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
108static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
109
110/*
111 * command status codes
112 */
113#define FC_COMPLETE		0
114#define FC_CMD_ABORTED		1
115#define FC_CMD_RESET		2
116#define FC_CMD_PLOGO		3
117#define FC_SNS_RCV		4
118#define FC_TRANS_ERR		5
119#define FC_DATA_OVRRUN		6
120#define FC_DATA_UNDRUN		7
121#define FC_ERROR		8
122#define FC_HRD_ERROR		9
123#define FC_CRC_ERROR		10
124#define FC_TIMED_OUT		11
125
126/*
127 * Error recovery timeout values.
128 */
129#define FC_SCSI_TM_TOV		(10 * HZ)
130#define FC_HOST_RESET_TIMEOUT	(30 * HZ)
131#define FC_CAN_QUEUE_PERIOD	(60 * HZ)
132
133#define FC_MAX_ERROR_CNT	5
134#define FC_MAX_RECOV_RETRY	3
135
136#define FC_FCP_DFLT_QUEUE_DEPTH 32
137
138/**
139 * fc_fcp_pkt_alloc() - Allocate a fcp_pkt
140 * @lport: The local port that the FCP packet is for
141 * @gfp:   GFP flags for allocation
142 *
143 * Return value: fcp_pkt structure or null on allocation failure.
144 * Context:	 Can be called from process context, no lock is required.
145 */
146static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lport, gfp_t gfp)
147{
148	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
149	struct fc_fcp_pkt *fsp;
150
151	fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
152	if (fsp) {
153		memset(fsp, 0, sizeof(*fsp));
154		fsp->lp = lport;
155		fsp->xfer_ddp = FC_XID_UNKNOWN;
156		atomic_set(&fsp->ref_cnt, 1);
157		init_timer(&fsp->timer);
158		fsp->timer.data = (unsigned long)fsp;
159		INIT_LIST_HEAD(&fsp->list);
160		spin_lock_init(&fsp->scsi_pkt_lock);
161	} else {
162		per_cpu_ptr(lport->stats, get_cpu())->FcpPktAllocFails++;
163		put_cpu();
164	}
165	return fsp;
166}
167
168/**
169 * fc_fcp_pkt_release() - Release hold on a fcp_pkt
170 * @fsp: The FCP packet to be released
171 *
172 * Context: Can be called from process or interrupt context,
173 *	    no lock is required.
174 */
175static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
176{
177	if (atomic_dec_and_test(&fsp->ref_cnt)) {
178		struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
179
180		mempool_free(fsp, si->scsi_pkt_pool);
181	}
182}
183
184/**
185 * fc_fcp_pkt_hold() - Hold a fcp_pkt
186 * @fsp: The FCP packet to be held
187 */
188static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
189{
190	atomic_inc(&fsp->ref_cnt);
191}
192
193/**
194 * fc_fcp_pkt_destory() - Release hold on a fcp_pkt
195 * @seq: The sequence that the FCP packet is on (required by destructor API)
196 * @fsp: The FCP packet to be released
197 *
198 * This routine is called by a destructor callback in the exch_seq_send()
199 * routine of the libfc Transport Template. The 'struct fc_seq' is a required
200 * argument even though it is not used by this routine.
201 *
202 * Context: No locking required.
203 */
204static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
205{
206	fc_fcp_pkt_release(fsp);
207}
208
209/**
210 * fc_fcp_lock_pkt() - Lock a fcp_pkt and increase its reference count
211 * @fsp: The FCP packet to be locked and incremented
212 *
213 * We should only return error if we return a command to SCSI-ml before
214 * getting a response. This can happen in cases where we send a abort, but
215 * do not wait for the response and the abort and command can be passing
216 * each other on the wire/network-layer.
217 *
218 * Note: this function locks the packet and gets a reference to allow
219 * callers to call the completion function while the lock is held and
220 * not have to worry about the packets refcount.
221 *
222 * TODO: Maybe we should just have callers grab/release the lock and
223 * have a function that they call to verify the fsp and grab a ref if
224 * needed.
225 */
226static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
227{
228	spin_lock_bh(&fsp->scsi_pkt_lock);
229	if (fsp->state & FC_SRB_COMPL) {
230		spin_unlock_bh(&fsp->scsi_pkt_lock);
231		return -EPERM;
232	}
233
234	fc_fcp_pkt_hold(fsp);
235	return 0;
236}
237
238/**
239 * fc_fcp_unlock_pkt() - Release a fcp_pkt's lock and decrement its
240 *			 reference count
241 * @fsp: The FCP packet to be unlocked and decremented
242 */
243static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
244{
245	spin_unlock_bh(&fsp->scsi_pkt_lock);
246	fc_fcp_pkt_release(fsp);
247}
248
249/**
250 * fc_fcp_timer_set() - Start a timer for a fcp_pkt
251 * @fsp:   The FCP packet to start a timer for
252 * @delay: The timeout period in jiffies
253 */
254static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
255{
256	if (!(fsp->state & FC_SRB_COMPL))
257		mod_timer(&fsp->timer, jiffies + delay);
258}
259
260/**
261 * fc_fcp_send_abort() - Send an abort for exchanges associated with a
262 *			 fcp_pkt
263 * @fsp: The FCP packet to abort exchanges on
264 */
265static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
266{
267	if (!fsp->seq_ptr)
268		return -EINVAL;
269
270	per_cpu_ptr(fsp->lp->stats, get_cpu())->FcpPktAborts++;
271	put_cpu();
272
273	fsp->state |= FC_SRB_ABORT_PENDING;
274	return fsp->lp->tt.seq_exch_abort(fsp->seq_ptr, 0);
275}
276
277/**
278 * fc_fcp_retry_cmd() - Retry a fcp_pkt
279 * @fsp: The FCP packet to be retried
280 *
281 * Sets the status code to be FC_ERROR and then calls
282 * fc_fcp_complete_locked() which in turn calls fc_io_compl().
283 * fc_io_compl() will notify the SCSI-ml that the I/O is done.
284 * The SCSI-ml will retry the command.
285 */
286static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp)
287{
288	if (fsp->seq_ptr) {
289		fsp->lp->tt.exch_done(fsp->seq_ptr);
290		fsp->seq_ptr = NULL;
291	}
292
293	fsp->state &= ~FC_SRB_ABORT_PENDING;
294	fsp->io_status = 0;
295	fsp->status_code = FC_ERROR;
296	fc_fcp_complete_locked(fsp);
297}
298
299/**
300 * fc_fcp_ddp_setup() - Calls a LLD's ddp_setup routine to set up DDP context
301 * @fsp: The FCP packet that will manage the DDP frames
302 * @xid: The XID that will be used for the DDP exchange
303 */
304void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
305{
306	struct fc_lport *lport;
307
308	lport = fsp->lp;
309	if ((fsp->req_flags & FC_SRB_READ) &&
310	    (lport->lro_enabled) && (lport->tt.ddp_setup)) {
311		if (lport->tt.ddp_setup(lport, xid, scsi_sglist(fsp->cmd),
312					scsi_sg_count(fsp->cmd)))
313			fsp->xfer_ddp = xid;
314	}
315}
316
317/**
318 * fc_fcp_ddp_done() - Calls a LLD's ddp_done routine to release any
319 *		       DDP related resources for a fcp_pkt
320 * @fsp: The FCP packet that DDP had been used on
321 */
322void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
323{
324	struct fc_lport *lport;
325
326	if (!fsp)
327		return;
328
329	if (fsp->xfer_ddp == FC_XID_UNKNOWN)
330		return;
331
332	lport = fsp->lp;
333	if (lport->tt.ddp_done) {
334		fsp->xfer_len = lport->tt.ddp_done(lport, fsp->xfer_ddp);
335		fsp->xfer_ddp = FC_XID_UNKNOWN;
336	}
337}
338
339/**
340 * fc_fcp_can_queue_ramp_up() - increases can_queue
341 * @lport: lport to ramp up can_queue
342 */
343static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
344{
345	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
346	unsigned long flags;
347	int can_queue;
348
349	spin_lock_irqsave(lport->host->host_lock, flags);
350
351	if (si->last_can_queue_ramp_up_time &&
352	    (time_before(jiffies, si->last_can_queue_ramp_up_time +
353			 FC_CAN_QUEUE_PERIOD)))
354		goto unlock;
355
356	if (time_before(jiffies, si->last_can_queue_ramp_down_time +
357			FC_CAN_QUEUE_PERIOD))
358		goto unlock;
359
360	si->last_can_queue_ramp_up_time = jiffies;
361
362	can_queue = lport->host->can_queue << 1;
363	if (can_queue >= si->max_can_queue) {
364		can_queue = si->max_can_queue;
365		si->last_can_queue_ramp_down_time = 0;
366	}
367	lport->host->can_queue = can_queue;
368	shost_printk(KERN_ERR, lport->host, "libfc: increased "
369		     "can_queue to %d.\n", can_queue);
370
371unlock:
372	spin_unlock_irqrestore(lport->host->host_lock, flags);
373}
374
375/**
376 * fc_fcp_can_queue_ramp_down() - reduces can_queue
377 * @lport: lport to reduce can_queue
378 *
379 * If we are getting memory allocation failures, then we may
380 * be trying to execute too many commands. We let the running
381 * commands complete or timeout, then try again with a reduced
382 * can_queue. Eventually we will hit the point where we run
383 * on all reserved structs.
384 */
385static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport)
386{
387	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
388	unsigned long flags;
389	int can_queue;
390
391	spin_lock_irqsave(lport->host->host_lock, flags);
392
393	if (si->last_can_queue_ramp_down_time &&
394	    (time_before(jiffies, si->last_can_queue_ramp_down_time +
395			 FC_CAN_QUEUE_PERIOD)))
396		goto unlock;
397
398	si->last_can_queue_ramp_down_time = jiffies;
399
400	can_queue = lport->host->can_queue;
401	can_queue >>= 1;
402	if (!can_queue)
403		can_queue = 1;
404	lport->host->can_queue = can_queue;
405	shost_printk(KERN_ERR, lport->host, "libfc: Could not allocate frame.\n"
406		     "Reducing can_queue to %d.\n", can_queue);
407
408unlock:
409	spin_unlock_irqrestore(lport->host->host_lock, flags);
410}
411
412/*
413 * fc_fcp_frame_alloc() -  Allocates fc_frame structure and buffer.
414 * @lport:	fc lport struct
415 * @len:	payload length
416 *
417 * Allocates fc_frame structure and buffer but if fails to allocate
418 * then reduce can_queue.
419 */
420static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport,
421						  size_t len)
422{
423	struct fc_frame *fp;
424
425	fp = fc_frame_alloc(lport, len);
426	if (likely(fp))
427		return fp;
428
429	per_cpu_ptr(lport->stats, get_cpu())->FcpFrameAllocFails++;
430	put_cpu();
431	/* error case */
432	fc_fcp_can_queue_ramp_down(lport);
433	return NULL;
434}
435
436/**
437 * fc_fcp_recv_data() - Handler for receiving SCSI-FCP data from a target
438 * @fsp: The FCP packet the data is on
439 * @fp:	 The data frame
440 */
441static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
442{
443	struct scsi_cmnd *sc = fsp->cmd;
444	struct fc_lport *lport = fsp->lp;
445	struct fc_stats *stats;
446	struct fc_frame_header *fh;
447	size_t start_offset;
448	size_t offset;
449	u32 crc;
450	u32 copy_len = 0;
451	size_t len;
452	void *buf;
453	struct scatterlist *sg;
454	u32 nents;
455	u8 host_bcode = FC_COMPLETE;
456
457	fh = fc_frame_header_get(fp);
458	offset = ntohl(fh->fh_parm_offset);
459	start_offset = offset;
460	len = fr_len(fp) - sizeof(*fh);
461	buf = fc_frame_payload_get(fp, 0);
462
463	/*
464	 * if this I/O is ddped then clear it and initiate recovery since data
465	 * frames are expected to be placed directly in that case.
466	 *
467	 * Indicate error to scsi-ml because something went wrong with the
468	 * ddp handling to get us here.
469	 */
470	if (fsp->xfer_ddp != FC_XID_UNKNOWN) {
471		fc_fcp_ddp_done(fsp);
472		FC_FCP_DBG(fsp, "DDP I/O in fc_fcp_recv_data set ERROR\n");
473		host_bcode = FC_ERROR;
474		goto err;
475	}
476	if (offset + len > fsp->data_len) {
477		/* this should never happen */
478		if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
479		    fc_frame_crc_check(fp))
480			goto crc_err;
481		FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
482			   "data_len %x\n", len, offset, fsp->data_len);
483
484		/* Data is corrupted indicate scsi-ml should retry */
485		host_bcode = FC_DATA_OVRRUN;
486		goto err;
487	}
488	if (offset != fsp->xfer_len)
489		fsp->state |= FC_SRB_DISCONTIG;
490
491	sg = scsi_sglist(sc);
492	nents = scsi_sg_count(sc);
493
494	if (!(fr_flags(fp) & FCPHF_CRC_UNCHECKED)) {
495		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
496						    &offset, NULL);
497	} else {
498		crc = crc32(~0, (u8 *) fh, sizeof(*fh));
499		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
500						    &offset, &crc);
501		buf = fc_frame_payload_get(fp, 0);
502		if (len % 4)
503			crc = crc32(crc, buf + len, 4 - (len % 4));
504
505		if (~crc != le32_to_cpu(fr_crc(fp))) {
506crc_err:
507			stats = per_cpu_ptr(lport->stats, get_cpu());
508			stats->ErrorFrames++;
509			/* per cpu count, not total count, but OK for limit */
510			if (stats->InvalidCRCCount++ < FC_MAX_ERROR_CNT)
511				printk(KERN_WARNING "libfc: CRC error on data "
512				       "frame for port (%6.6x)\n",
513				       lport->port_id);
514			put_cpu();
515			/*
516			 * Assume the frame is total garbage.
517			 * We may have copied it over the good part
518			 * of the buffer.
519			 * If so, we need to retry the entire operation.
520			 * Otherwise, ignore it.
521			 */
522			if (fsp->state & FC_SRB_DISCONTIG) {
523				host_bcode = FC_CRC_ERROR;
524				goto err;
525			}
526			return;
527		}
528	}
529
530	if (fsp->xfer_contig_end == start_offset)
531		fsp->xfer_contig_end += copy_len;
532	fsp->xfer_len += copy_len;
533
534	/*
535	 * In the very rare event that this data arrived after the response
536	 * and completes the transfer, call the completion handler.
537	 */
538	if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
539	    fsp->xfer_len == fsp->data_len - fsp->scsi_resid)
540		fc_fcp_complete_locked(fsp);
541	return;
542err:
543	fc_fcp_recovery(fsp, host_bcode);
544}
545
546/**
547 * fc_fcp_send_data() - Send SCSI data to a target
548 * @fsp:      The FCP packet the data is on
549 * @sp:	      The sequence the data is to be sent on
550 * @offset:   The starting offset for this data request
551 * @seq_blen: The burst length for this data request
552 *
553 * Called after receiving a Transfer Ready data descriptor.
554 * If the LLD is capable of sequence offload then send down the
555 * seq_blen amount of data in single frame, otherwise send
556 * multiple frames of the maximum frame payload supported by
557 * the target port.
558 */
559static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
560			    size_t offset, size_t seq_blen)
561{
562	struct fc_exch *ep;
563	struct scsi_cmnd *sc;
564	struct scatterlist *sg;
565	struct fc_frame *fp = NULL;
566	struct fc_lport *lport = fsp->lp;
567	struct page *page;
568	size_t remaining;
569	size_t t_blen;
570	size_t tlen;
571	size_t sg_bytes;
572	size_t frame_offset, fh_parm_offset;
573	size_t off;
574	int error;
575	void *data = NULL;
576	void *page_addr;
577	int using_sg = lport->sg_supp;
578	u32 f_ctl;
579
580	WARN_ON(seq_blen <= 0);
581	if (unlikely(offset + seq_blen > fsp->data_len)) {
582		/* this should never happen */
583		FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
584			   "offset %zx\n", seq_blen, offset);
585		fc_fcp_send_abort(fsp);
586		return 0;
587	} else if (offset != fsp->xfer_len) {
588		/* Out of Order Data Request - no problem, but unexpected. */
589		FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
590			   "seq_blen %zx offset %zx\n", seq_blen, offset);
591	}
592
593	/*
594	 * if LLD is capable of seq_offload then set transport
595	 * burst length (t_blen) to seq_blen, otherwise set t_blen
596	 * to max FC frame payload previously set in fsp->max_payload.
597	 */
598	t_blen = fsp->max_payload;
599	if (lport->seq_offload) {
600		t_blen = min(seq_blen, (size_t)lport->lso_max);
601		FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
602			   fsp, seq_blen, lport->lso_max, t_blen);
603	}
604
605	if (t_blen > 512)
606		t_blen &= ~(512 - 1);	/* round down to block size */
607	sc = fsp->cmd;
608
609	remaining = seq_blen;
610	fh_parm_offset = frame_offset = offset;
611	tlen = 0;
612	seq = lport->tt.seq_start_next(seq);
613	f_ctl = FC_FC_REL_OFF;
614	WARN_ON(!seq);
615
616	sg = scsi_sglist(sc);
617
618	while (remaining > 0 && sg) {
619		if (offset >= sg->length) {
620			offset -= sg->length;
621			sg = sg_next(sg);
622			continue;
623		}
624		if (!fp) {
625			tlen = min(t_blen, remaining);
626
627			/*
628			 * TODO.  Temporary workaround.	 fc_seq_send() can't
629			 * handle odd lengths in non-linear skbs.
630			 * This will be the final fragment only.
631			 */
632			if (tlen % 4)
633				using_sg = 0;
634			fp = fc_frame_alloc(lport, using_sg ? 0 : tlen);
635			if (!fp)
636				return -ENOMEM;
637
638			data = fc_frame_header_get(fp) + 1;
639			fh_parm_offset = frame_offset;
640			fr_max_payload(fp) = fsp->max_payload;
641		}
642
643		off = offset + sg->offset;
644		sg_bytes = min(tlen, sg->length - offset);
645		sg_bytes = min(sg_bytes,
646			       (size_t) (PAGE_SIZE - (off & ~PAGE_MASK)));
647		page = sg_page(sg) + (off >> PAGE_SHIFT);
648		if (using_sg) {
649			get_page(page);
650			skb_fill_page_desc(fp_skb(fp),
651					   skb_shinfo(fp_skb(fp))->nr_frags,
652					   page, off & ~PAGE_MASK, sg_bytes);
653			fp_skb(fp)->data_len += sg_bytes;
654			fr_len(fp) += sg_bytes;
655			fp_skb(fp)->truesize += PAGE_SIZE;
656		} else {
657			/*
658			 * The scatterlist item may be bigger than PAGE_SIZE,
659			 * but we must not cross pages inside the kmap.
660			 */
661			page_addr = kmap_atomic(page);
662			memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
663			       sg_bytes);
664			kunmap_atomic(page_addr);
665			data += sg_bytes;
666		}
667		offset += sg_bytes;
668		frame_offset += sg_bytes;
669		tlen -= sg_bytes;
670		remaining -= sg_bytes;
671
672		if ((skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN) &&
673		    (tlen))
674			continue;
675
676		/*
677		 * Send sequence with transfer sequence initiative in case
678		 * this is last FCP frame of the sequence.
679		 */
680		if (remaining == 0)
681			f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
682
683		ep = fc_seq_exch(seq);
684		fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
685			       FC_TYPE_FCP, f_ctl, fh_parm_offset);
686
687		/*
688		 * send fragment using for a sequence.
689		 */
690		error = lport->tt.seq_send(lport, seq, fp);
691		if (error) {
692			WARN_ON(1);		/* send error should be rare */
693			return error;
694		}
695		fp = NULL;
696	}
697	fsp->xfer_len += seq_blen;	/* premature count? */
698	return 0;
699}
700
701/**
702 * fc_fcp_abts_resp() - Receive an ABTS response
703 * @fsp: The FCP packet that is being aborted
704 * @fp:	 The response frame
705 */
706static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
707{
708	int ba_done = 1;
709	struct fc_ba_rjt *brp;
710	struct fc_frame_header *fh;
711
712	fh = fc_frame_header_get(fp);
713	switch (fh->fh_r_ctl) {
714	case FC_RCTL_BA_ACC:
715		break;
716	case FC_RCTL_BA_RJT:
717		brp = fc_frame_payload_get(fp, sizeof(*brp));
718		if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
719			break;
720		/* fall thru */
721	default:
722		/*
723		 * we will let the command timeout
724		 * and scsi-ml recover in this case,
725		 * therefore cleared the ba_done flag.
726		 */
727		ba_done = 0;
728	}
729
730	if (ba_done) {
731		fsp->state |= FC_SRB_ABORTED;
732		fsp->state &= ~FC_SRB_ABORT_PENDING;
733
734		if (fsp->wait_for_comp)
735			complete(&fsp->tm_done);
736		else
737			fc_fcp_complete_locked(fsp);
738	}
739}
740
741/**
742 * fc_fcp_recv() - Receive an FCP frame
743 * @seq: The sequence the frame is on
744 * @fp:	 The received frame
745 * @arg: The related FCP packet
746 *
747 * Context: Called from Soft IRQ context. Can not be called
748 *	    holding the FCP packet list lock.
749 */
750static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
751{
752	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
753	struct fc_lport *lport = fsp->lp;
754	struct fc_frame_header *fh;
755	struct fcp_txrdy *dd;
756	u8 r_ctl;
757	int rc = 0;
758
759	if (IS_ERR(fp)) {
760		fc_fcp_error(fsp, fp);
761		return;
762	}
763
764	fh = fc_frame_header_get(fp);
765	r_ctl = fh->fh_r_ctl;
766
767	if (lport->state != LPORT_ST_READY)
768		goto out;
769	if (fc_fcp_lock_pkt(fsp))
770		goto out;
771
772	if (fh->fh_type == FC_TYPE_BLS) {
773		fc_fcp_abts_resp(fsp, fp);
774		goto unlock;
775	}
776
777	if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING))
778		goto unlock;
779
780	if (r_ctl == FC_RCTL_DD_DATA_DESC) {
781		/*
782		 * received XFER RDY from the target
783		 * need to send data to the target
784		 */
785		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
786		dd = fc_frame_payload_get(fp, sizeof(*dd));
787		WARN_ON(!dd);
788
789		rc = fc_fcp_send_data(fsp, seq,
790				      (size_t) ntohl(dd->ft_data_ro),
791				      (size_t) ntohl(dd->ft_burst_len));
792		if (!rc)
793			seq->rec_data = fsp->xfer_len;
794	} else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
795		/*
796		 * received a DATA frame
797		 * next we will copy the data to the system buffer
798		 */
799		WARN_ON(fr_len(fp) < sizeof(*fh));	/* len may be 0 */
800		fc_fcp_recv_data(fsp, fp);
801		seq->rec_data = fsp->xfer_contig_end;
802	} else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
803		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
804
805		fc_fcp_resp(fsp, fp);
806	} else {
807		FC_FCP_DBG(fsp, "unexpected frame.  r_ctl %x\n", r_ctl);
808	}
809unlock:
810	fc_fcp_unlock_pkt(fsp);
811out:
812	fc_frame_free(fp);
813}
814
815/**
816 * fc_fcp_resp() - Handler for FCP responses
817 * @fsp: The FCP packet the response is for
818 * @fp:	 The response frame
819 */
820static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
821{
822	struct fc_frame_header *fh;
823	struct fcp_resp *fc_rp;
824	struct fcp_resp_ext *rp_ex;
825	struct fcp_resp_rsp_info *fc_rp_info;
826	u32 plen;
827	u32 expected_len;
828	u32 respl = 0;
829	u32 snsl = 0;
830	u8 flags = 0;
831
832	plen = fr_len(fp);
833	fh = (struct fc_frame_header *)fr_hdr(fp);
834	if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
835		goto len_err;
836	plen -= sizeof(*fh);
837	fc_rp = (struct fcp_resp *)(fh + 1);
838	fsp->cdb_status = fc_rp->fr_status;
839	flags = fc_rp->fr_flags;
840	fsp->scsi_comp_flags = flags;
841	expected_len = fsp->data_len;
842
843	/* if ddp, update xfer len */
844	fc_fcp_ddp_done(fsp);
845
846	if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
847		rp_ex = (void *)(fc_rp + 1);
848		if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
849			if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
850				goto len_err;
851			fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
852			if (flags & FCP_RSP_LEN_VAL) {
853				respl = ntohl(rp_ex->fr_rsp_len);
854				if ((respl != FCP_RESP_RSP_INFO_LEN4) &&
855				    (respl != FCP_RESP_RSP_INFO_LEN8))
856					goto len_err;
857				if (fsp->wait_for_comp) {
858					/* Abuse cdb_status for rsp code */
859					fsp->cdb_status = fc_rp_info->rsp_code;
860					complete(&fsp->tm_done);
861					/*
862					 * tmfs will not have any scsi cmd so
863					 * exit here
864					 */
865					return;
866				}
867			}
868			if (flags & FCP_SNS_LEN_VAL) {
869				snsl = ntohl(rp_ex->fr_sns_len);
870				if (snsl > SCSI_SENSE_BUFFERSIZE)
871					snsl = SCSI_SENSE_BUFFERSIZE;
872				memcpy(fsp->cmd->sense_buffer,
873				       (char *)fc_rp_info + respl, snsl);
874			}
875		}
876		if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
877			if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
878				goto len_err;
879			if (flags & FCP_RESID_UNDER) {
880				fsp->scsi_resid = ntohl(rp_ex->fr_resid);
881				/*
882				 * The cmnd->underflow is the minimum number of
883				 * bytes that must be transferred for this
884				 * command.  Provided a sense condition is not
885				 * present, make sure the actual amount
886				 * transferred is at least the underflow value
887				 * or fail.
888				 */
889				if (!(flags & FCP_SNS_LEN_VAL) &&
890				    (fc_rp->fr_status == 0) &&
891				    (scsi_bufflen(fsp->cmd) -
892				     fsp->scsi_resid) < fsp->cmd->underflow)
893					goto err;
894				expected_len -= fsp->scsi_resid;
895			} else {
896				fsp->status_code = FC_ERROR;
897			}
898		}
899	}
900	fsp->state |= FC_SRB_RCV_STATUS;
901
902	/*
903	 * Check for missing or extra data frames.
904	 */
905	if (unlikely(fsp->cdb_status == SAM_STAT_GOOD &&
906		     fsp->xfer_len != expected_len)) {
907		if (fsp->xfer_len < expected_len) {
908			/*
909			 * Some data may be queued locally,
910			 * Wait a at least one jiffy to see if it is delivered.
911			 * If this expires without data, we may do SRR.
912			 */
913			fc_fcp_timer_set(fsp, 2);
914			return;
915		}
916		fsp->status_code = FC_DATA_OVRRUN;
917		FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx greater than expected, "
918			   "len %x, data len %x\n",
919			   fsp->rport->port_id,
920			   fsp->xfer_len, expected_len, fsp->data_len);
921	}
922	fc_fcp_complete_locked(fsp);
923	return;
924
925len_err:
926	FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
927		   "snsl %u\n", flags, fr_len(fp), respl, snsl);
928err:
929	fsp->status_code = FC_ERROR;
930	fc_fcp_complete_locked(fsp);
931}
932
933/**
934 * fc_fcp_complete_locked() - Complete processing of a fcp_pkt with the
935 *			      fcp_pkt lock held
936 * @fsp: The FCP packet to be completed
937 *
938 * This function may sleep if a timer is pending. The packet lock must be
939 * held, and the host lock must not be held.
940 */
941static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
942{
943	struct fc_lport *lport = fsp->lp;
944	struct fc_seq *seq;
945	struct fc_exch *ep;
946	u32 f_ctl;
947
948	if (fsp->state & FC_SRB_ABORT_PENDING)
949		return;
950
951	if (fsp->state & FC_SRB_ABORTED) {
952		if (!fsp->status_code)
953			fsp->status_code = FC_CMD_ABORTED;
954	} else {
955		/*
956		 * Test for transport underrun, independent of response
957		 * underrun status.
958		 */
959		if (fsp->cdb_status == SAM_STAT_GOOD &&
960		    fsp->xfer_len < fsp->data_len && !fsp->io_status &&
961		    (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
962		     fsp->xfer_len < fsp->data_len - fsp->scsi_resid))
963			fsp->status_code = FC_DATA_UNDRUN;
964	}
965
966	seq = fsp->seq_ptr;
967	if (seq) {
968		fsp->seq_ptr = NULL;
969		if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
970			struct fc_frame *conf_frame;
971			struct fc_seq *csp;
972
973			csp = lport->tt.seq_start_next(seq);
974			conf_frame = fc_fcp_frame_alloc(fsp->lp, 0);
975			if (conf_frame) {
976				f_ctl = FC_FC_SEQ_INIT;
977				f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
978				ep = fc_seq_exch(seq);
979				fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
980					       ep->did, ep->sid,
981					       FC_TYPE_FCP, f_ctl, 0);
982				lport->tt.seq_send(lport, csp, conf_frame);
983			}
984		}
985		lport->tt.exch_done(seq);
986	}
987	/*
988	 * Some resets driven by SCSI are not I/Os and do not have
989	 * SCSI commands associated with the requests. We should not
990	 * call I/O completion if we do not have a SCSI command.
991	 */
992	if (fsp->cmd)
993		fc_io_compl(fsp);
994}
995
996/**
997 * fc_fcp_cleanup_cmd() - Cancel the active exchange on a fcp_pkt
998 * @fsp:   The FCP packet whose exchanges should be canceled
999 * @error: The reason for the cancellation
1000 */
1001static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
1002{
1003	struct fc_lport *lport = fsp->lp;
1004
1005	if (fsp->seq_ptr) {
1006		lport->tt.exch_done(fsp->seq_ptr);
1007		fsp->seq_ptr = NULL;
1008	}
1009	fsp->status_code = error;
1010}
1011
1012/**
1013 * fc_fcp_cleanup_each_cmd() - Cancel all exchanges on a local port
1014 * @lport: The local port whose exchanges should be canceled
1015 * @id:	   The target's ID
1016 * @lun:   The LUN
1017 * @error: The reason for cancellation
1018 *
1019 * If lun or id is -1, they are ignored.
1020 */
1021static void fc_fcp_cleanup_each_cmd(struct fc_lport *lport, unsigned int id,
1022				    unsigned int lun, int error)
1023{
1024	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1025	struct fc_fcp_pkt *fsp;
1026	struct scsi_cmnd *sc_cmd;
1027	unsigned long flags;
1028
1029	spin_lock_irqsave(&si->scsi_queue_lock, flags);
1030restart:
1031	list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
1032		sc_cmd = fsp->cmd;
1033		if (id != -1 && scmd_id(sc_cmd) != id)
1034			continue;
1035
1036		if (lun != -1 && sc_cmd->device->lun != lun)
1037			continue;
1038
1039		fc_fcp_pkt_hold(fsp);
1040		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1041
1042		if (!fc_fcp_lock_pkt(fsp)) {
1043			fc_fcp_cleanup_cmd(fsp, error);
1044			fc_io_compl(fsp);
1045			fc_fcp_unlock_pkt(fsp);
1046		}
1047
1048		fc_fcp_pkt_release(fsp);
1049		spin_lock_irqsave(&si->scsi_queue_lock, flags);
1050		/*
1051		 * while we dropped the lock multiple pkts could
1052		 * have been released, so we have to start over.
1053		 */
1054		goto restart;
1055	}
1056	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1057}
1058
1059/**
1060 * fc_fcp_abort_io() - Abort all FCP-SCSI exchanges on a local port
1061 * @lport: The local port whose exchanges are to be aborted
1062 */
1063static void fc_fcp_abort_io(struct fc_lport *lport)
1064{
1065	fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_HRD_ERROR);
1066}
1067
1068/**
1069 * fc_fcp_pkt_send() - Send a fcp_pkt
1070 * @lport: The local port to send the FCP packet on
1071 * @fsp:   The FCP packet to send
1072 *
1073 * Return:  Zero for success and -1 for failure
1074 * Locks:   Called without locks held
1075 */
1076static int fc_fcp_pkt_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp)
1077{
1078	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1079	unsigned long flags;
1080	int rc;
1081
1082	fsp->cmd->SCp.ptr = (char *)fsp;
1083	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1084	fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
1085
1086	int_to_scsilun(fsp->cmd->device->lun, &fsp->cdb_cmd.fc_lun);
1087	memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
1088
1089	spin_lock_irqsave(&si->scsi_queue_lock, flags);
1090	list_add_tail(&fsp->list, &si->scsi_pkt_queue);
1091	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1092	rc = lport->tt.fcp_cmd_send(lport, fsp, fc_fcp_recv);
1093	if (unlikely(rc)) {
1094		spin_lock_irqsave(&si->scsi_queue_lock, flags);
1095		fsp->cmd->SCp.ptr = NULL;
1096		list_del(&fsp->list);
1097		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1098	}
1099
1100	return rc;
1101}
1102
1103/**
1104 * get_fsp_rec_tov() - Helper function to get REC_TOV
1105 * @fsp: the FCP packet
1106 *
1107 * Returns rec tov in jiffies as rpriv->e_d_tov + 1 second
1108 */
1109static inline unsigned int get_fsp_rec_tov(struct fc_fcp_pkt *fsp)
1110{
1111	struct fc_rport_libfc_priv *rpriv = fsp->rport->dd_data;
1112
1113	return msecs_to_jiffies(rpriv->e_d_tov) + HZ;
1114}
1115
1116/**
1117 * fc_fcp_cmd_send() - Send a FCP command
1118 * @lport: The local port to send the command on
1119 * @fsp:   The FCP packet the command is on
1120 * @resp:  The handler for the response
1121 */
1122static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1123			   void (*resp)(struct fc_seq *,
1124					struct fc_frame *fp,
1125					void *arg))
1126{
1127	struct fc_frame *fp;
1128	struct fc_seq *seq;
1129	struct fc_rport *rport;
1130	struct fc_rport_libfc_priv *rpriv;
1131	const size_t len = sizeof(fsp->cdb_cmd);
1132	int rc = 0;
1133
1134	if (fc_fcp_lock_pkt(fsp))
1135		return 0;
1136
1137	fp = fc_fcp_frame_alloc(lport, sizeof(fsp->cdb_cmd));
1138	if (!fp) {
1139		rc = -1;
1140		goto unlock;
1141	}
1142
1143	memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
1144	fr_fsp(fp) = fsp;
1145	rport = fsp->rport;
1146	fsp->max_payload = rport->maxframe_size;
1147	rpriv = rport->dd_data;
1148
1149	fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
1150		       rpriv->local_port->port_id, FC_TYPE_FCP,
1151		       FC_FCTL_REQ, 0);
1152
1153	seq = lport->tt.exch_seq_send(lport, fp, resp, fc_fcp_pkt_destroy,
1154				      fsp, 0);
1155	if (!seq) {
1156		rc = -1;
1157		goto unlock;
1158	}
1159	fsp->seq_ptr = seq;
1160	fc_fcp_pkt_hold(fsp);	/* hold for fc_fcp_pkt_destroy */
1161
1162	setup_timer(&fsp->timer, fc_fcp_timeout, (unsigned long)fsp);
1163	if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1164		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1165
1166unlock:
1167	fc_fcp_unlock_pkt(fsp);
1168	return rc;
1169}
1170
1171/**
1172 * fc_fcp_error() - Handler for FCP layer errors
1173 * @fsp: The FCP packet the error is on
1174 * @fp:	 The frame that has errored
1175 */
1176static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1177{
1178	int error = PTR_ERR(fp);
1179
1180	if (fc_fcp_lock_pkt(fsp))
1181		return;
1182
1183	if (error == -FC_EX_CLOSED) {
1184		fc_fcp_retry_cmd(fsp);
1185		goto unlock;
1186	}
1187
1188	/*
1189	 * clear abort pending, because the lower layer
1190	 * decided to force completion.
1191	 */
1192	fsp->state &= ~FC_SRB_ABORT_PENDING;
1193	fsp->status_code = FC_CMD_PLOGO;
1194	fc_fcp_complete_locked(fsp);
1195unlock:
1196	fc_fcp_unlock_pkt(fsp);
1197}
1198
1199/**
1200 * fc_fcp_pkt_abort() - Abort a fcp_pkt
1201 * @fsp:   The FCP packet to abort on
1202 *
1203 * Called to send an abort and then wait for abort completion
1204 */
1205static int fc_fcp_pkt_abort(struct fc_fcp_pkt *fsp)
1206{
1207	int rc = FAILED;
1208	unsigned long ticks_left;
1209
1210	if (fc_fcp_send_abort(fsp))
1211		return FAILED;
1212
1213	init_completion(&fsp->tm_done);
1214	fsp->wait_for_comp = 1;
1215
1216	spin_unlock_bh(&fsp->scsi_pkt_lock);
1217	ticks_left = wait_for_completion_timeout(&fsp->tm_done,
1218							FC_SCSI_TM_TOV);
1219	spin_lock_bh(&fsp->scsi_pkt_lock);
1220	fsp->wait_for_comp = 0;
1221
1222	if (!ticks_left) {
1223		FC_FCP_DBG(fsp, "target abort cmd  failed\n");
1224	} else if (fsp->state & FC_SRB_ABORTED) {
1225		FC_FCP_DBG(fsp, "target abort cmd  passed\n");
1226		rc = SUCCESS;
1227		fc_fcp_complete_locked(fsp);
1228	}
1229
1230	return rc;
1231}
1232
1233/**
1234 * fc_lun_reset_send() - Send LUN reset command
1235 * @data: The FCP packet that identifies the LUN to be reset
1236 */
1237static void fc_lun_reset_send(unsigned long data)
1238{
1239	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1240	struct fc_lport *lport = fsp->lp;
1241
1242	if (lport->tt.fcp_cmd_send(lport, fsp, fc_tm_done)) {
1243		if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
1244			return;
1245		if (fc_fcp_lock_pkt(fsp))
1246			return;
1247		setup_timer(&fsp->timer, fc_lun_reset_send, (unsigned long)fsp);
1248		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1249		fc_fcp_unlock_pkt(fsp);
1250	}
1251}
1252
1253/**
1254 * fc_lun_reset() - Send a LUN RESET command to a device
1255 *		    and wait for the reply
1256 * @lport: The local port to sent the command on
1257 * @fsp:   The FCP packet that identifies the LUN to be reset
1258 * @id:	   The SCSI command ID
1259 * @lun:   The LUN ID to be reset
1260 */
1261static int fc_lun_reset(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1262			unsigned int id, unsigned int lun)
1263{
1264	int rc;
1265
1266	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1267	fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
1268	int_to_scsilun(lun, &fsp->cdb_cmd.fc_lun);
1269
1270	fsp->wait_for_comp = 1;
1271	init_completion(&fsp->tm_done);
1272
1273	fc_lun_reset_send((unsigned long)fsp);
1274
1275	/*
1276	 * wait for completion of reset
1277	 * after that make sure all commands are terminated
1278	 */
1279	rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1280
1281	spin_lock_bh(&fsp->scsi_pkt_lock);
1282	fsp->state |= FC_SRB_COMPL;
1283	spin_unlock_bh(&fsp->scsi_pkt_lock);
1284
1285	del_timer_sync(&fsp->timer);
1286
1287	spin_lock_bh(&fsp->scsi_pkt_lock);
1288	if (fsp->seq_ptr) {
1289		lport->tt.exch_done(fsp->seq_ptr);
1290		fsp->seq_ptr = NULL;
1291	}
1292	fsp->wait_for_comp = 0;
1293	spin_unlock_bh(&fsp->scsi_pkt_lock);
1294
1295	if (!rc) {
1296		FC_SCSI_DBG(lport, "lun reset failed\n");
1297		return FAILED;
1298	}
1299
1300	/* cdb_status holds the tmf's rsp code */
1301	if (fsp->cdb_status != FCP_TMF_CMPL)
1302		return FAILED;
1303
1304	FC_SCSI_DBG(lport, "lun reset to lun %u completed\n", lun);
1305	fc_fcp_cleanup_each_cmd(lport, id, lun, FC_CMD_ABORTED);
1306	return SUCCESS;
1307}
1308
1309/**
1310 * fc_tm_done() - Task Management response handler
1311 * @seq: The sequence that the response is on
1312 * @fp:	 The response frame
1313 * @arg: The FCP packet the response is for
1314 */
1315static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1316{
1317	struct fc_fcp_pkt *fsp = arg;
1318	struct fc_frame_header *fh;
1319
1320	if (IS_ERR(fp)) {
1321		/*
1322		 * If there is an error just let it timeout or wait
1323		 * for TMF to be aborted if it timedout.
1324		 *
1325		 * scsi-eh will escalate for when either happens.
1326		 */
1327		return;
1328	}
1329
1330	if (fc_fcp_lock_pkt(fsp))
1331		goto out;
1332
1333	/*
1334	 * raced with eh timeout handler.
1335	 */
1336	if (!fsp->seq_ptr || !fsp->wait_for_comp)
1337		goto out_unlock;
1338
1339	fh = fc_frame_header_get(fp);
1340	if (fh->fh_type != FC_TYPE_BLS)
1341		fc_fcp_resp(fsp, fp);
1342	fsp->seq_ptr = NULL;
1343	fsp->lp->tt.exch_done(seq);
1344out_unlock:
1345	fc_fcp_unlock_pkt(fsp);
1346out:
1347	fc_frame_free(fp);
1348}
1349
1350/**
1351 * fc_fcp_cleanup() - Cleanup all FCP exchanges on a local port
1352 * @lport: The local port to be cleaned up
1353 */
1354static void fc_fcp_cleanup(struct fc_lport *lport)
1355{
1356	fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_ERROR);
1357}
1358
1359/**
1360 * fc_fcp_timeout() - Handler for fcp_pkt timeouts
1361 * @data: The FCP packet that has timed out
1362 *
1363 * If REC is supported then just issue it and return. The REC exchange will
1364 * complete or time out and recovery can continue at that point. Otherwise,
1365 * if the response has been received without all the data it has been
1366 * ER_TIMEOUT since the response was received. If the response has not been
1367 * received we see if data was received recently. If it has been then we
1368 * continue waiting, otherwise, we abort the command.
1369 */
1370static void fc_fcp_timeout(unsigned long data)
1371{
1372	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1373	struct fc_rport *rport = fsp->rport;
1374	struct fc_rport_libfc_priv *rpriv = rport->dd_data;
1375
1376	if (fc_fcp_lock_pkt(fsp))
1377		return;
1378
1379	if (fsp->cdb_cmd.fc_tm_flags)
1380		goto unlock;
1381
1382	fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
1383
1384	if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1385		fc_fcp_rec(fsp);
1386	else if (fsp->state & FC_SRB_RCV_STATUS)
1387		fc_fcp_complete_locked(fsp);
1388	else
1389		fc_fcp_recovery(fsp, FC_TIMED_OUT);
1390	fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
1391unlock:
1392	fc_fcp_unlock_pkt(fsp);
1393}
1394
1395/**
1396 * fc_fcp_rec() - Send a REC ELS request
1397 * @fsp: The FCP packet to send the REC request on
1398 */
1399static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
1400{
1401	struct fc_lport *lport;
1402	struct fc_frame *fp;
1403	struct fc_rport *rport;
1404	struct fc_rport_libfc_priv *rpriv;
1405
1406	lport = fsp->lp;
1407	rport = fsp->rport;
1408	rpriv = rport->dd_data;
1409	if (!fsp->seq_ptr || rpriv->rp_state != RPORT_ST_READY) {
1410		fsp->status_code = FC_HRD_ERROR;
1411		fsp->io_status = 0;
1412		fc_fcp_complete_locked(fsp);
1413		return;
1414	}
1415
1416	fp = fc_fcp_frame_alloc(lport, sizeof(struct fc_els_rec));
1417	if (!fp)
1418		goto retry;
1419
1420	fr_seq(fp) = fsp->seq_ptr;
1421	fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
1422		       rpriv->local_port->port_id, FC_TYPE_ELS,
1423		       FC_FCTL_REQ, 0);
1424	if (lport->tt.elsct_send(lport, rport->port_id, fp, ELS_REC,
1425				 fc_fcp_rec_resp, fsp,
1426				 2 * lport->r_a_tov)) {
1427		fc_fcp_pkt_hold(fsp);		/* hold while REC outstanding */
1428		return;
1429	}
1430retry:
1431	if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1432		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1433	else
1434		fc_fcp_recovery(fsp, FC_TIMED_OUT);
1435}
1436
1437/**
1438 * fc_fcp_rec_resp() - Handler for REC ELS responses
1439 * @seq: The sequence the response is on
1440 * @fp:	 The response frame
1441 * @arg: The FCP packet the response is on
1442 *
1443 * If the response is a reject then the scsi layer will handle
1444 * the timeout. If the response is a LS_ACC then if the I/O was not completed
1445 * set the timeout and return. If the I/O was completed then complete the
1446 * exchange and tell the SCSI layer.
1447 */
1448static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1449{
1450	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
1451	struct fc_els_rec_acc *recp;
1452	struct fc_els_ls_rjt *rjt;
1453	u32 e_stat;
1454	u8 opcode;
1455	u32 offset;
1456	enum dma_data_direction data_dir;
1457	enum fc_rctl r_ctl;
1458	struct fc_rport_libfc_priv *rpriv;
1459
1460	if (IS_ERR(fp)) {
1461		fc_fcp_rec_error(fsp, fp);
1462		return;
1463	}
1464
1465	if (fc_fcp_lock_pkt(fsp))
1466		goto out;
1467
1468	fsp->recov_retry = 0;
1469	opcode = fc_frame_payload_op(fp);
1470	if (opcode == ELS_LS_RJT) {
1471		rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1472		switch (rjt->er_reason) {
1473		default:
1474			FC_FCP_DBG(fsp, "device %x unexpected REC reject "
1475				   "reason %d expl %d\n",
1476				   fsp->rport->port_id, rjt->er_reason,
1477				   rjt->er_explan);
1478			/* fall through */
1479		case ELS_RJT_UNSUP:
1480			FC_FCP_DBG(fsp, "device does not support REC\n");
1481			rpriv = fsp->rport->dd_data;
1482			/*
1483			 * if we do not spport RECs or got some bogus
1484			 * reason then resetup timer so we check for
1485			 * making progress.
1486			 */
1487			rpriv->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
1488			break;
1489		case ELS_RJT_LOGIC:
1490		case ELS_RJT_UNAB:
1491			/*
1492			 * If no data transfer, the command frame got dropped
1493			 * so we just retry.  If data was transferred, we
1494			 * lost the response but the target has no record,
1495			 * so we abort and retry.
1496			 */
1497			if (rjt->er_explan == ELS_EXPL_OXID_RXID &&
1498			    fsp->xfer_len == 0) {
1499				fc_fcp_retry_cmd(fsp);
1500				break;
1501			}
1502			fc_fcp_recovery(fsp, FC_ERROR);
1503			break;
1504		}
1505	} else if (opcode == ELS_LS_ACC) {
1506		if (fsp->state & FC_SRB_ABORTED)
1507			goto unlock_out;
1508
1509		data_dir = fsp->cmd->sc_data_direction;
1510		recp = fc_frame_payload_get(fp, sizeof(*recp));
1511		offset = ntohl(recp->reca_fc4value);
1512		e_stat = ntohl(recp->reca_e_stat);
1513
1514		if (e_stat & ESB_ST_COMPLETE) {
1515
1516			/*
1517			 * The exchange is complete.
1518			 *
1519			 * For output, we must've lost the response.
1520			 * For input, all data must've been sent.
1521			 * We lost may have lost the response
1522			 * (and a confirmation was requested) and maybe
1523			 * some data.
1524			 *
1525			 * If all data received, send SRR
1526			 * asking for response.	 If partial data received,
1527			 * or gaps, SRR requests data at start of gap.
1528			 * Recovery via SRR relies on in-order-delivery.
1529			 */
1530			if (data_dir == DMA_TO_DEVICE) {
1531				r_ctl = FC_RCTL_DD_CMD_STATUS;
1532			} else if (fsp->xfer_contig_end == offset) {
1533				r_ctl = FC_RCTL_DD_CMD_STATUS;
1534			} else {
1535				offset = fsp->xfer_contig_end;
1536				r_ctl = FC_RCTL_DD_SOL_DATA;
1537			}
1538			fc_fcp_srr(fsp, r_ctl, offset);
1539		} else if (e_stat & ESB_ST_SEQ_INIT) {
1540			/*
1541			 * The remote port has the initiative, so just
1542			 * keep waiting for it to complete.
1543			 */
1544			fc_fcp_timer_set(fsp,  get_fsp_rec_tov(fsp));
1545		} else {
1546
1547			/*
1548			 * The exchange is incomplete, we have seq. initiative.
1549			 * Lost response with requested confirmation,
1550			 * lost confirmation, lost transfer ready or
1551			 * lost write data.
1552			 *
1553			 * For output, if not all data was received, ask
1554			 * for transfer ready to be repeated.
1555			 *
1556			 * If we received or sent all the data, send SRR to
1557			 * request response.
1558			 *
1559			 * If we lost a response, we may have lost some read
1560			 * data as well.
1561			 */
1562			r_ctl = FC_RCTL_DD_SOL_DATA;
1563			if (data_dir == DMA_TO_DEVICE) {
1564				r_ctl = FC_RCTL_DD_CMD_STATUS;
1565				if (offset < fsp->data_len)
1566					r_ctl = FC_RCTL_DD_DATA_DESC;
1567			} else if (offset == fsp->xfer_contig_end) {
1568				r_ctl = FC_RCTL_DD_CMD_STATUS;
1569			} else if (fsp->xfer_contig_end < offset) {
1570				offset = fsp->xfer_contig_end;
1571			}
1572			fc_fcp_srr(fsp, r_ctl, offset);
1573		}
1574	}
1575unlock_out:
1576	fc_fcp_unlock_pkt(fsp);
1577out:
1578	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
1579	fc_frame_free(fp);
1580}
1581
1582/**
1583 * fc_fcp_rec_error() - Handler for REC errors
1584 * @fsp: The FCP packet the error is on
1585 * @fp:	 The REC frame
1586 */
1587static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1588{
1589	int error = PTR_ERR(fp);
1590
1591	if (fc_fcp_lock_pkt(fsp))
1592		goto out;
1593
1594	switch (error) {
1595	case -FC_EX_CLOSED:
1596		fc_fcp_retry_cmd(fsp);
1597		break;
1598
1599	default:
1600		FC_FCP_DBG(fsp, "REC %p fid %6.6x error unexpected error %d\n",
1601			   fsp, fsp->rport->port_id, error);
1602		fsp->status_code = FC_CMD_PLOGO;
1603		/* fall through */
1604
1605	case -FC_EX_TIMEOUT:
1606		/*
1607		 * Assume REC or LS_ACC was lost.
1608		 * The exchange manager will have aborted REC, so retry.
1609		 */
1610		FC_FCP_DBG(fsp, "REC fid %6.6x error error %d retry %d/%d\n",
1611			   fsp->rport->port_id, error, fsp->recov_retry,
1612			   FC_MAX_RECOV_RETRY);
1613		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1614			fc_fcp_rec(fsp);
1615		else
1616			fc_fcp_recovery(fsp, FC_ERROR);
1617		break;
1618	}
1619	fc_fcp_unlock_pkt(fsp);
1620out:
1621	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
1622}
1623
1624/**
1625 * fc_fcp_recovery() - Handler for fcp_pkt recovery
1626 * @fsp: The FCP pkt that needs to be aborted
1627 */
1628static void fc_fcp_recovery(struct fc_fcp_pkt *fsp, u8 code)
1629{
1630	fsp->status_code = code;
1631	fsp->cdb_status = 0;
1632	fsp->io_status = 0;
1633	/*
1634	 * if this fails then we let the scsi command timer fire and
1635	 * scsi-ml escalate.
1636	 */
1637	fc_fcp_send_abort(fsp);
1638}
1639
1640/**
1641 * fc_fcp_srr() - Send a SRR request (Sequence Retransmission Request)
1642 * @fsp:   The FCP packet the SRR is to be sent on
1643 * @r_ctl: The R_CTL field for the SRR request
1644 * This is called after receiving status but insufficient data, or
1645 * when expecting status but the request has timed out.
1646 */
1647static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
1648{
1649	struct fc_lport *lport = fsp->lp;
1650	struct fc_rport *rport;
1651	struct fc_rport_libfc_priv *rpriv;
1652	struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1653	struct fc_seq *seq;
1654	struct fcp_srr *srr;
1655	struct fc_frame *fp;
1656	unsigned int rec_tov;
1657
1658	rport = fsp->rport;
1659	rpriv = rport->dd_data;
1660
1661	if (!(rpriv->flags & FC_RP_FLAGS_RETRY) ||
1662	    rpriv->rp_state != RPORT_ST_READY)
1663		goto retry;			/* shouldn't happen */
1664	fp = fc_fcp_frame_alloc(lport, sizeof(*srr));
1665	if (!fp)
1666		goto retry;
1667
1668	srr = fc_frame_payload_get(fp, sizeof(*srr));
1669	memset(srr, 0, sizeof(*srr));
1670	srr->srr_op = ELS_SRR;
1671	srr->srr_ox_id = htons(ep->oxid);
1672	srr->srr_rx_id = htons(ep->rxid);
1673	srr->srr_r_ctl = r_ctl;
1674	srr->srr_rel_off = htonl(offset);
1675
1676	fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
1677		       rpriv->local_port->port_id, FC_TYPE_FCP,
1678		       FC_FCTL_REQ, 0);
1679
1680	rec_tov = get_fsp_rec_tov(fsp);
1681	seq = lport->tt.exch_seq_send(lport, fp, fc_fcp_srr_resp,
1682				      fc_fcp_pkt_destroy,
1683				      fsp, jiffies_to_msecs(rec_tov));
1684	if (!seq)
1685		goto retry;
1686
1687	fsp->recov_seq = seq;
1688	fsp->xfer_len = offset;
1689	fsp->xfer_contig_end = offset;
1690	fsp->state &= ~FC_SRB_RCV_STATUS;
1691	fc_fcp_pkt_hold(fsp);		/* hold for outstanding SRR */
1692	return;
1693retry:
1694	fc_fcp_retry_cmd(fsp);
1695}
1696
1697/**
1698 * fc_fcp_srr_resp() - Handler for SRR response
1699 * @seq: The sequence the SRR is on
1700 * @fp:	 The SRR frame
1701 * @arg: The FCP packet the SRR is on
1702 */
1703static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1704{
1705	struct fc_fcp_pkt *fsp = arg;
1706	struct fc_frame_header *fh;
1707
1708	if (IS_ERR(fp)) {
1709		fc_fcp_srr_error(fsp, fp);
1710		return;
1711	}
1712
1713	if (fc_fcp_lock_pkt(fsp))
1714		goto out;
1715
1716	fh = fc_frame_header_get(fp);
1717	/*
1718	 * BUG? fc_fcp_srr_error calls exch_done which would release
1719	 * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
1720	 * then fc_exch_timeout would be sending an abort. The exch_done
1721	 * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
1722	 * an abort response though.
1723	 */
1724	if (fh->fh_type == FC_TYPE_BLS) {
1725		fc_fcp_unlock_pkt(fsp);
1726		return;
1727	}
1728
1729	switch (fc_frame_payload_op(fp)) {
1730	case ELS_LS_ACC:
1731		fsp->recov_retry = 0;
1732		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1733		break;
1734	case ELS_LS_RJT:
1735	default:
1736		fc_fcp_recovery(fsp, FC_ERROR);
1737		break;
1738	}
1739	fc_fcp_unlock_pkt(fsp);
1740out:
1741	fsp->lp->tt.exch_done(seq);
1742	fc_frame_free(fp);
1743}
1744
1745/**
1746 * fc_fcp_srr_error() - Handler for SRR errors
1747 * @fsp: The FCP packet that the SRR error is on
1748 * @fp:	 The SRR frame
1749 */
1750static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1751{
1752	if (fc_fcp_lock_pkt(fsp))
1753		goto out;
1754	switch (PTR_ERR(fp)) {
1755	case -FC_EX_TIMEOUT:
1756		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1757			fc_fcp_rec(fsp);
1758		else
1759			fc_fcp_recovery(fsp, FC_TIMED_OUT);
1760		break;
1761	case -FC_EX_CLOSED:			/* e.g., link failure */
1762		/* fall through */
1763	default:
1764		fc_fcp_retry_cmd(fsp);
1765		break;
1766	}
1767	fc_fcp_unlock_pkt(fsp);
1768out:
1769	fsp->lp->tt.exch_done(fsp->recov_seq);
1770}
1771
1772/**
1773 * fc_fcp_lport_queue_ready() - Determine if the lport and it's queue is ready
1774 * @lport: The local port to be checked
1775 */
1776static inline int fc_fcp_lport_queue_ready(struct fc_lport *lport)
1777{
1778	/* lock ? */
1779	return (lport->state == LPORT_ST_READY) &&
1780		lport->link_up && !lport->qfull;
1781}
1782
1783/**
1784 * fc_queuecommand() - The queuecommand function of the SCSI template
1785 * @shost: The Scsi_Host that the command was issued to
1786 * @cmd:   The scsi_cmnd to be executed
1787 *
1788 * This is the i/o strategy routine, called by the SCSI layer.
1789 */
1790int fc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *sc_cmd)
1791{
1792	struct fc_lport *lport = shost_priv(shost);
1793	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1794	struct fc_fcp_pkt *fsp;
1795	struct fc_rport_libfc_priv *rpriv;
1796	int rval;
1797	int rc = 0;
1798	struct fc_stats *stats;
1799
1800	rval = fc_remote_port_chkready(rport);
1801	if (rval) {
1802		sc_cmd->result = rval;
1803		sc_cmd->scsi_done(sc_cmd);
1804		return 0;
1805	}
1806
1807	if (!*(struct fc_remote_port **)rport->dd_data) {
1808		/*
1809		 * rport is transitioning from blocked/deleted to
1810		 * online
1811		 */
1812		sc_cmd->result = DID_IMM_RETRY << 16;
1813		sc_cmd->scsi_done(sc_cmd);
1814		goto out;
1815	}
1816
1817	rpriv = rport->dd_data;
1818
1819	if (!fc_fcp_lport_queue_ready(lport)) {
1820		if (lport->qfull)
1821			fc_fcp_can_queue_ramp_down(lport);
1822		rc = SCSI_MLQUEUE_HOST_BUSY;
1823		goto out;
1824	}
1825
1826	fsp = fc_fcp_pkt_alloc(lport, GFP_ATOMIC);
1827	if (fsp == NULL) {
1828		rc = SCSI_MLQUEUE_HOST_BUSY;
1829		goto out;
1830	}
1831
1832	/*
1833	 * build the libfc request pkt
1834	 */
1835	fsp->cmd = sc_cmd;	/* save the cmd */
1836	fsp->rport = rport;	/* set the remote port ptr */
1837
1838	/*
1839	 * set up the transfer length
1840	 */
1841	fsp->data_len = scsi_bufflen(sc_cmd);
1842	fsp->xfer_len = 0;
1843
1844	/*
1845	 * setup the data direction
1846	 */
1847	stats = per_cpu_ptr(lport->stats, get_cpu());
1848	if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
1849		fsp->req_flags = FC_SRB_READ;
1850		stats->InputRequests++;
1851		stats->InputBytes += fsp->data_len;
1852	} else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
1853		fsp->req_flags = FC_SRB_WRITE;
1854		stats->OutputRequests++;
1855		stats->OutputBytes += fsp->data_len;
1856	} else {
1857		fsp->req_flags = 0;
1858		stats->ControlRequests++;
1859	}
1860	put_cpu();
1861
1862	/*
1863	 * send it to the lower layer
1864	 * if we get -1 return then put the request in the pending
1865	 * queue.
1866	 */
1867	rval = fc_fcp_pkt_send(lport, fsp);
1868	if (rval != 0) {
1869		fsp->state = FC_SRB_FREE;
1870		fc_fcp_pkt_release(fsp);
1871		rc = SCSI_MLQUEUE_HOST_BUSY;
1872	}
1873out:
1874	return rc;
1875}
1876EXPORT_SYMBOL(fc_queuecommand);
1877
1878/**
1879 * fc_io_compl() - Handle responses for completed commands
1880 * @fsp: The FCP packet that is complete
1881 *
1882 * Translates fcp_pkt errors to a Linux SCSI errors.
1883 * The fcp packet lock must be held when calling.
1884 */
1885static void fc_io_compl(struct fc_fcp_pkt *fsp)
1886{
1887	struct fc_fcp_internal *si;
1888	struct scsi_cmnd *sc_cmd;
1889	struct fc_lport *lport;
1890	unsigned long flags;
1891
1892	/* release outstanding ddp context */
1893	fc_fcp_ddp_done(fsp);
1894
1895	fsp->state |= FC_SRB_COMPL;
1896	if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
1897		spin_unlock_bh(&fsp->scsi_pkt_lock);
1898		del_timer_sync(&fsp->timer);
1899		spin_lock_bh(&fsp->scsi_pkt_lock);
1900	}
1901
1902	lport = fsp->lp;
1903	si = fc_get_scsi_internal(lport);
1904
1905	/*
1906	 * if can_queue ramp down is done then try can_queue ramp up
1907	 * since commands are completing now.
1908	 */
1909	if (si->last_can_queue_ramp_down_time)
1910		fc_fcp_can_queue_ramp_up(lport);
1911
1912	sc_cmd = fsp->cmd;
1913	CMD_SCSI_STATUS(sc_cmd) = fsp->cdb_status;
1914	switch (fsp->status_code) {
1915	case FC_COMPLETE:
1916		if (fsp->cdb_status == 0) {
1917			/*
1918			 * good I/O status
1919			 */
1920			sc_cmd->result = DID_OK << 16;
1921			if (fsp->scsi_resid)
1922				CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1923		} else {
1924			/*
1925			 * transport level I/O was ok but scsi
1926			 * has non zero status
1927			 */
1928			sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
1929		}
1930		break;
1931	case FC_ERROR:
1932		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1933			   "due to FC_ERROR\n");
1934		sc_cmd->result = DID_ERROR << 16;
1935		break;
1936	case FC_DATA_UNDRUN:
1937		if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) {
1938			/*
1939			 * scsi status is good but transport level
1940			 * underrun.
1941			 */
1942			if (fsp->state & FC_SRB_RCV_STATUS) {
1943				sc_cmd->result = DID_OK << 16;
1944			} else {
1945				FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml"
1946					   " due to FC_DATA_UNDRUN (trans)\n");
1947				sc_cmd->result = DID_ERROR << 16;
1948			}
1949		} else {
1950			/*
1951			 * scsi got underrun, this is an error
1952			 */
1953			FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1954				   "due to FC_DATA_UNDRUN (scsi)\n");
1955			CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1956			sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1957		}
1958		break;
1959	case FC_DATA_OVRRUN:
1960		/*
1961		 * overrun is an error
1962		 */
1963		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1964			   "due to FC_DATA_OVRRUN\n");
1965		sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1966		break;
1967	case FC_CMD_ABORTED:
1968		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1969			  "due to FC_CMD_ABORTED\n");
1970		sc_cmd->result = (DID_ERROR << 16) | fsp->io_status;
1971		break;
1972	case FC_CMD_RESET:
1973		FC_FCP_DBG(fsp, "Returning DID_RESET to scsi-ml "
1974			   "due to FC_CMD_RESET\n");
1975		sc_cmd->result = (DID_RESET << 16);
1976		break;
1977	case FC_HRD_ERROR:
1978		FC_FCP_DBG(fsp, "Returning DID_NO_CONNECT to scsi-ml "
1979			   "due to FC_HRD_ERROR\n");
1980		sc_cmd->result = (DID_NO_CONNECT << 16);
1981		break;
1982	case FC_CRC_ERROR:
1983		FC_FCP_DBG(fsp, "Returning DID_PARITY to scsi-ml "
1984			   "due to FC_CRC_ERROR\n");
1985		sc_cmd->result = (DID_PARITY << 16);
1986		break;
1987	case FC_TIMED_OUT:
1988		FC_FCP_DBG(fsp, "Returning DID_BUS_BUSY to scsi-ml "
1989			   "due to FC_TIMED_OUT\n");
1990		sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
1991		break;
1992	default:
1993		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1994			   "due to unknown error\n");
1995		sc_cmd->result = (DID_ERROR << 16);
1996		break;
1997	}
1998
1999	if (lport->state != LPORT_ST_READY && fsp->status_code != FC_COMPLETE)
2000		sc_cmd->result = (DID_TRANSPORT_DISRUPTED << 16);
2001
2002	spin_lock_irqsave(&si->scsi_queue_lock, flags);
2003	list_del(&fsp->list);
2004	sc_cmd->SCp.ptr = NULL;
2005	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2006	sc_cmd->scsi_done(sc_cmd);
2007
2008	/* release ref from initial allocation in queue command */
2009	fc_fcp_pkt_release(fsp);
2010}
2011
2012/**
2013 * fc_eh_abort() - Abort a command
2014 * @sc_cmd: The SCSI command to abort
2015 *
2016 * From SCSI host template.
2017 * Send an ABTS to the target device and wait for the response.
2018 */
2019int fc_eh_abort(struct scsi_cmnd *sc_cmd)
2020{
2021	struct fc_fcp_pkt *fsp;
2022	struct fc_lport *lport;
2023	struct fc_fcp_internal *si;
2024	int rc = FAILED;
2025	unsigned long flags;
2026	int rval;
2027
2028	rval = fc_block_scsi_eh(sc_cmd);
2029	if (rval)
2030		return rval;
2031
2032	lport = shost_priv(sc_cmd->device->host);
2033	if (lport->state != LPORT_ST_READY)
2034		return rc;
2035	else if (!lport->link_up)
2036		return rc;
2037
2038	si = fc_get_scsi_internal(lport);
2039	spin_lock_irqsave(&si->scsi_queue_lock, flags);
2040	fsp = CMD_SP(sc_cmd);
2041	if (!fsp) {
2042		/* command completed while scsi eh was setting up */
2043		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2044		return SUCCESS;
2045	}
2046	/* grab a ref so the fsp and sc_cmd cannot be released from under us */
2047	fc_fcp_pkt_hold(fsp);
2048	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2049
2050	if (fc_fcp_lock_pkt(fsp)) {
2051		/* completed while we were waiting for timer to be deleted */
2052		rc = SUCCESS;
2053		goto release_pkt;
2054	}
2055
2056	rc = fc_fcp_pkt_abort(fsp);
2057	fc_fcp_unlock_pkt(fsp);
2058
2059release_pkt:
2060	fc_fcp_pkt_release(fsp);
2061	return rc;
2062}
2063EXPORT_SYMBOL(fc_eh_abort);
2064
2065/**
2066 * fc_eh_device_reset() - Reset a single LUN
2067 * @sc_cmd: The SCSI command which identifies the device whose
2068 *	    LUN is to be reset
2069 *
2070 * Set from SCSI host template.
2071 */
2072int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
2073{
2074	struct fc_lport *lport;
2075	struct fc_fcp_pkt *fsp;
2076	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
2077	int rc = FAILED;
2078	int rval;
2079
2080	rval = fc_block_scsi_eh(sc_cmd);
2081	if (rval)
2082		return rval;
2083
2084	lport = shost_priv(sc_cmd->device->host);
2085
2086	if (lport->state != LPORT_ST_READY)
2087		return rc;
2088
2089	FC_SCSI_DBG(lport, "Resetting rport (%6.6x)\n", rport->port_id);
2090
2091	fsp = fc_fcp_pkt_alloc(lport, GFP_NOIO);
2092	if (fsp == NULL) {
2093		printk(KERN_WARNING "libfc: could not allocate scsi_pkt\n");
2094		goto out;
2095	}
2096
2097	/*
2098	 * Build the libfc request pkt. Do not set the scsi cmnd, because
2099	 * the sc passed in is not setup for execution like when sent
2100	 * through the queuecommand callout.
2101	 */
2102	fsp->rport = rport;	/* set the remote port ptr */
2103
2104	/*
2105	 * flush outstanding commands
2106	 */
2107	rc = fc_lun_reset(lport, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
2108	fsp->state = FC_SRB_FREE;
2109	fc_fcp_pkt_release(fsp);
2110
2111out:
2112	return rc;
2113}
2114EXPORT_SYMBOL(fc_eh_device_reset);
2115
2116/**
2117 * fc_eh_host_reset() - Reset a Scsi_Host.
2118 * @sc_cmd: The SCSI command that identifies the SCSI host to be reset
2119 */
2120int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
2121{
2122	struct Scsi_Host *shost = sc_cmd->device->host;
2123	struct fc_lport *lport = shost_priv(shost);
2124	unsigned long wait_tmo;
2125
2126	FC_SCSI_DBG(lport, "Resetting host\n");
2127
2128	fc_block_scsi_eh(sc_cmd);
2129
2130	lport->tt.lport_reset(lport);
2131	wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
2132	while (!fc_fcp_lport_queue_ready(lport) && time_before(jiffies,
2133							       wait_tmo))
2134		msleep(1000);
2135
2136	if (fc_fcp_lport_queue_ready(lport)) {
2137		shost_printk(KERN_INFO, shost, "libfc: Host reset succeeded "
2138			     "on port (%6.6x)\n", lport->port_id);
2139		return SUCCESS;
2140	} else {
2141		shost_printk(KERN_INFO, shost, "libfc: Host reset failed, "
2142			     "port (%6.6x) is not ready.\n",
2143			     lport->port_id);
2144		return FAILED;
2145	}
2146}
2147EXPORT_SYMBOL(fc_eh_host_reset);
2148
2149/**
2150 * fc_slave_alloc() - Configure the queue depth of a Scsi_Host
2151 * @sdev: The SCSI device that identifies the SCSI host
2152 *
2153 * Configures queue depth based on host's cmd_per_len. If not set
2154 * then we use the libfc default.
2155 */
2156int fc_slave_alloc(struct scsi_device *sdev)
2157{
2158	struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
2159
2160	if (!rport || fc_remote_port_chkready(rport))
2161		return -ENXIO;
2162
2163	if (sdev->tagged_supported)
2164		scsi_activate_tcq(sdev, FC_FCP_DFLT_QUEUE_DEPTH);
2165	else
2166		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev),
2167					FC_FCP_DFLT_QUEUE_DEPTH);
2168
2169	return 0;
2170}
2171EXPORT_SYMBOL(fc_slave_alloc);
2172
2173/**
2174 * fc_change_queue_depth() - Change a device's queue depth
2175 * @sdev:   The SCSI device whose queue depth is to change
2176 * @qdepth: The new queue depth
2177 * @reason: The resason for the change
2178 */
2179int fc_change_queue_depth(struct scsi_device *sdev, int qdepth, int reason)
2180{
2181	switch (reason) {
2182	case SCSI_QDEPTH_DEFAULT:
2183		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);
2184		break;
2185	case SCSI_QDEPTH_QFULL:
2186		scsi_track_queue_full(sdev, qdepth);
2187		break;
2188	case SCSI_QDEPTH_RAMP_UP:
2189		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);
2190		break;
2191	default:
2192		return -EOPNOTSUPP;
2193	}
2194	return sdev->queue_depth;
2195}
2196EXPORT_SYMBOL(fc_change_queue_depth);
2197
2198/**
2199 * fc_change_queue_type() - Change a device's queue type
2200 * @sdev:     The SCSI device whose queue depth is to change
2201 * @tag_type: Identifier for queue type
2202 */
2203int fc_change_queue_type(struct scsi_device *sdev, int tag_type)
2204{
2205	if (sdev->tagged_supported) {
2206		scsi_set_tag_type(sdev, tag_type);
2207		if (tag_type)
2208			scsi_activate_tcq(sdev, sdev->queue_depth);
2209		else
2210			scsi_deactivate_tcq(sdev, sdev->queue_depth);
2211	} else
2212		tag_type = 0;
2213
2214	return tag_type;
2215}
2216EXPORT_SYMBOL(fc_change_queue_type);
2217
2218/**
2219 * fc_fcp_destory() - Tear down the FCP layer for a given local port
2220 * @lport: The local port that no longer needs the FCP layer
2221 */
2222void fc_fcp_destroy(struct fc_lport *lport)
2223{
2224	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
2225
2226	if (!list_empty(&si->scsi_pkt_queue))
2227		printk(KERN_ERR "libfc: Leaked SCSI packets when destroying "
2228		       "port (%6.6x)\n", lport->port_id);
2229
2230	mempool_destroy(si->scsi_pkt_pool);
2231	kfree(si);
2232	lport->scsi_priv = NULL;
2233}
2234EXPORT_SYMBOL(fc_fcp_destroy);
2235
2236int fc_setup_fcp(void)
2237{
2238	int rc = 0;
2239
2240	scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
2241					    sizeof(struct fc_fcp_pkt),
2242					    0, SLAB_HWCACHE_ALIGN, NULL);
2243	if (!scsi_pkt_cachep) {
2244		printk(KERN_ERR "libfc: Unable to allocate SRB cache, "
2245		       "module load failed!");
2246		rc = -ENOMEM;
2247	}
2248
2249	return rc;
2250}
2251
2252void fc_destroy_fcp(void)
2253{
2254	if (scsi_pkt_cachep)
2255		kmem_cache_destroy(scsi_pkt_cachep);
2256}
2257
2258/**
2259 * fc_fcp_init() - Initialize the FCP layer for a local port
2260 * @lport: The local port to initialize the exchange layer for
2261 */
2262int fc_fcp_init(struct fc_lport *lport)
2263{
2264	int rc;
2265	struct fc_fcp_internal *si;
2266
2267	if (!lport->tt.fcp_cmd_send)
2268		lport->tt.fcp_cmd_send = fc_fcp_cmd_send;
2269
2270	if (!lport->tt.fcp_cleanup)
2271		lport->tt.fcp_cleanup = fc_fcp_cleanup;
2272
2273	if (!lport->tt.fcp_abort_io)
2274		lport->tt.fcp_abort_io = fc_fcp_abort_io;
2275
2276	si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
2277	if (!si)
2278		return -ENOMEM;
2279	lport->scsi_priv = si;
2280	si->max_can_queue = lport->host->can_queue;
2281	INIT_LIST_HEAD(&si->scsi_pkt_queue);
2282	spin_lock_init(&si->scsi_queue_lock);
2283
2284	si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
2285	if (!si->scsi_pkt_pool) {
2286		rc = -ENOMEM;
2287		goto free_internal;
2288	}
2289	return 0;
2290
2291free_internal:
2292	kfree(si);
2293	return rc;
2294}
2295EXPORT_SYMBOL(fc_fcp_init);
2296