fc_fcp.c revision 7414705ea4aef9ce438e547f3138a680d2d1096c
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
31#include <scsi/scsi_tcq.h>
32#include <scsi/scsi.h>
33#include <scsi/scsi_host.h>
34#include <scsi/scsi_device.h>
35#include <scsi/scsi_cmnd.h>
36
37#include <scsi/fc/fc_fc2.h>
38
39#include <scsi/libfc.h>
40#include <scsi/fc_encode.h>
41
42MODULE_AUTHOR("Open-FCoE.org");
43MODULE_DESCRIPTION("libfc");
44MODULE_LICENSE("GPL v2");
45
46unsigned int fc_debug_logging;
47module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO|S_IWUSR);
48MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");
49
50static struct kmem_cache *scsi_pkt_cachep;
51
52/* SRB state definitions */
53#define FC_SRB_FREE		0		/* cmd is free */
54#define FC_SRB_CMD_SENT		(1 << 0)	/* cmd has been sent */
55#define FC_SRB_RCV_STATUS	(1 << 1)	/* response has arrived */
56#define FC_SRB_ABORT_PENDING	(1 << 2)	/* cmd abort sent to device */
57#define FC_SRB_ABORTED		(1 << 3)	/* abort acknowleged */
58#define FC_SRB_DISCONTIG	(1 << 4)	/* non-sequential data recvd */
59#define FC_SRB_COMPL		(1 << 5)	/* fc_io_compl has been run */
60#define FC_SRB_FCP_PROCESSING_TMO (1 << 6)	/* timer function processing */
61#define FC_SRB_NOMEM		(1 << 7)	/* dropped to out of mem */
62
63#define FC_SRB_READ		(1 << 1)
64#define FC_SRB_WRITE		(1 << 0)
65
66/*
67 * The SCp.ptr should be tested and set under the host lock. NULL indicates
68 * that the command has been retruned to the scsi layer.
69 */
70#define CMD_SP(Cmnd)		    ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)
71#define CMD_ENTRY_STATUS(Cmnd)	    ((Cmnd)->SCp.have_data_in)
72#define CMD_COMPL_STATUS(Cmnd)	    ((Cmnd)->SCp.this_residual)
73#define CMD_SCSI_STATUS(Cmnd)	    ((Cmnd)->SCp.Status)
74#define CMD_RESID_LEN(Cmnd)	    ((Cmnd)->SCp.buffers_residual)
75
76struct fc_fcp_internal {
77	mempool_t	*scsi_pkt_pool;
78	struct list_head scsi_pkt_queue;
79	u8		throttled;
80};
81
82#define fc_get_scsi_internal(x)	((struct fc_fcp_internal *)(x)->scsi_priv)
83
84/*
85 * function prototypes
86 * FC scsi I/O related functions
87 */
88static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
89static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
90static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
91static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
92static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
93static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp);
94static void fc_timeout_error(struct fc_fcp_pkt *);
95static void fc_fcp_timeout(unsigned long data);
96static void fc_fcp_rec(struct fc_fcp_pkt *);
97static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
98static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
99static void fc_io_compl(struct fc_fcp_pkt *);
100
101static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
102static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
103static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
104
105/*
106 * command status codes
107 */
108#define FC_COMPLETE		0
109#define FC_CMD_ABORTED		1
110#define FC_CMD_RESET		2
111#define FC_CMD_PLOGO		3
112#define FC_SNS_RCV		4
113#define FC_TRANS_ERR		5
114#define FC_DATA_OVRRUN		6
115#define FC_DATA_UNDRUN		7
116#define FC_ERROR		8
117#define FC_HRD_ERROR		9
118#define FC_CMD_TIME_OUT		10
119
120/*
121 * Error recovery timeout values.
122 */
123#define FC_SCSI_ER_TIMEOUT	(10 * HZ)
124#define FC_SCSI_TM_TOV		(10 * HZ)
125#define FC_SCSI_REC_TOV		(2 * HZ)
126#define FC_HOST_RESET_TIMEOUT	(30 * HZ)
127
128#define FC_MAX_ERROR_CNT	5
129#define FC_MAX_RECOV_RETRY	3
130
131#define FC_FCP_DFLT_QUEUE_DEPTH 32
132
133/**
134 * fc_fcp_pkt_alloc - allocation routine for scsi_pkt packet
135 * @lp:		fc lport struct
136 * @gfp:	gfp flags for allocation
137 *
138 * This is used by upper layer scsi driver.
139 * Return Value : scsi_pkt structure or null on allocation failure.
140 * Context	: call from process context. no locking required.
141 */
142static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lp, gfp_t gfp)
143{
144	struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
145	struct fc_fcp_pkt *fsp;
146
147	fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
148	if (fsp) {
149		memset(fsp, 0, sizeof(*fsp));
150		fsp->lp = lp;
151		atomic_set(&fsp->ref_cnt, 1);
152		init_timer(&fsp->timer);
153		INIT_LIST_HEAD(&fsp->list);
154		spin_lock_init(&fsp->scsi_pkt_lock);
155	}
156	return fsp;
157}
158
159/**
160 * fc_fcp_pkt_release() - release hold on scsi_pkt packet
161 * @fsp:	fcp packet struct
162 *
163 * This is used by upper layer scsi driver.
164 * Context	: call from process  and interrupt context.
165 *		  no locking required
166 */
167static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
168{
169	if (atomic_dec_and_test(&fsp->ref_cnt)) {
170		struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
171
172		mempool_free(fsp, si->scsi_pkt_pool);
173	}
174}
175
176static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
177{
178	atomic_inc(&fsp->ref_cnt);
179}
180
181/**
182 * fc_fcp_pkt_destory() - release hold on scsi_pkt packet
183 * @seq:		exchange sequence
184 * @fsp:	fcp packet struct
185 *
186 * Release hold on scsi_pkt packet set to keep scsi_pkt
187 * till EM layer exch resource is not freed.
188 * Context	: called from from EM layer.
189 *		  no locking required
190 */
191static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
192{
193	fc_fcp_pkt_release(fsp);
194}
195
196/**
197 * fc_fcp_lock_pkt() - lock a packet and get a ref to it.
198 * @fsp:	fcp packet
199 *
200 * We should only return error if we return a command to scsi-ml before
201 * getting a response. This can happen in cases where we send a abort, but
202 * do not wait for the response and the abort and command can be passing
203 * each other on the wire/network-layer.
204 *
205 * Note: this function locks the packet and gets a reference to allow
206 * callers to call the completion function while the lock is held and
207 * not have to worry about the packets refcount.
208 *
209 * TODO: Maybe we should just have callers grab/release the lock and
210 * have a function that they call to verify the fsp and grab a ref if
211 * needed.
212 */
213static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
214{
215	spin_lock_bh(&fsp->scsi_pkt_lock);
216	if (fsp->state & FC_SRB_COMPL) {
217		spin_unlock_bh(&fsp->scsi_pkt_lock);
218		return -EPERM;
219	}
220
221	fc_fcp_pkt_hold(fsp);
222	return 0;
223}
224
225static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
226{
227	spin_unlock_bh(&fsp->scsi_pkt_lock);
228	fc_fcp_pkt_release(fsp);
229}
230
231static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
232{
233	if (!(fsp->state & FC_SRB_COMPL))
234		mod_timer(&fsp->timer, jiffies + delay);
235}
236
237static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
238{
239	if (!fsp->seq_ptr)
240		return -EINVAL;
241
242	fsp->state |= FC_SRB_ABORT_PENDING;
243	return fsp->lp->tt.seq_exch_abort(fsp->seq_ptr, 0);
244}
245
246/*
247 * Retry command.
248 * An abort isn't needed.
249 */
250static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp)
251{
252	if (fsp->seq_ptr) {
253		fsp->lp->tt.exch_done(fsp->seq_ptr);
254		fsp->seq_ptr = NULL;
255	}
256
257	fsp->state &= ~FC_SRB_ABORT_PENDING;
258	fsp->io_status = 0;
259	fsp->status_code = FC_ERROR;
260	fc_fcp_complete_locked(fsp);
261}
262
263/*
264 * fc_fcp_ddp_setup - calls to LLD's ddp_setup to set up DDP
265 * transfer for a read I/O indicated by the fc_fcp_pkt.
266 * @fsp: ptr to the fc_fcp_pkt
267 *
268 * This is called in exch_seq_send() when we have a newly allocated
269 * exchange with a valid exchange id to setup ddp.
270 *
271 * returns: none
272 */
273void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
274{
275	struct fc_lport *lp;
276
277	if (!fsp)
278		return;
279
280	lp = fsp->lp;
281	if ((fsp->req_flags & FC_SRB_READ) &&
282	    (lp->lro_enabled) && (lp->tt.ddp_setup)) {
283		if (lp->tt.ddp_setup(lp, xid, scsi_sglist(fsp->cmd),
284				     scsi_sg_count(fsp->cmd)))
285			fsp->xfer_ddp = xid;
286	}
287}
288EXPORT_SYMBOL(fc_fcp_ddp_setup);
289
290/*
291 * fc_fcp_ddp_done - calls to LLD's ddp_done to release any
292 * DDP related resources for this I/O if it is initialized
293 * as a ddp transfer
294 * @fsp: ptr to the fc_fcp_pkt
295 *
296 * returns: none
297 */
298static void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
299{
300	struct fc_lport *lp;
301
302	if (!fsp)
303		return;
304
305	lp = fsp->lp;
306	if (fsp->xfer_ddp && lp->tt.ddp_done) {
307		fsp->xfer_len = lp->tt.ddp_done(lp, fsp->xfer_ddp);
308		fsp->xfer_ddp = 0;
309	}
310}
311
312
313/*
314 * Receive SCSI data from target.
315 * Called after receiving solicited data.
316 */
317static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
318{
319	struct scsi_cmnd *sc = fsp->cmd;
320	struct fc_lport *lp = fsp->lp;
321	struct fcoe_dev_stats *stats;
322	struct fc_frame_header *fh;
323	size_t start_offset;
324	size_t offset;
325	u32 crc;
326	u32 copy_len = 0;
327	size_t len;
328	void *buf;
329	struct scatterlist *sg;
330	size_t remaining;
331
332	fh = fc_frame_header_get(fp);
333	offset = ntohl(fh->fh_parm_offset);
334	start_offset = offset;
335	len = fr_len(fp) - sizeof(*fh);
336	buf = fc_frame_payload_get(fp, 0);
337
338	/* if this I/O is ddped, update xfer len */
339	fc_fcp_ddp_done(fsp);
340
341	if (offset + len > fsp->data_len) {
342		/* this should never happen */
343		if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
344		    fc_frame_crc_check(fp))
345			goto crc_err;
346		FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
347			   "data_len %x\n", len, offset, fsp->data_len);
348		fc_fcp_retry_cmd(fsp);
349		return;
350	}
351	if (offset != fsp->xfer_len)
352		fsp->state |= FC_SRB_DISCONTIG;
353
354	crc = 0;
355	if (fr_flags(fp) & FCPHF_CRC_UNCHECKED)
356		crc = crc32(~0, (u8 *) fh, sizeof(*fh));
357
358	sg = scsi_sglist(sc);
359	remaining = len;
360
361	while (remaining > 0 && sg) {
362		size_t off;
363		void *page_addr;
364		size_t sg_bytes;
365
366		if (offset >= sg->length) {
367			offset -= sg->length;
368			sg = sg_next(sg);
369			continue;
370		}
371		sg_bytes = min(remaining, sg->length - offset);
372
373		/*
374		 * The scatterlist item may be bigger than PAGE_SIZE,
375		 * but we are limited to mapping PAGE_SIZE at a time.
376		 */
377		off = offset + sg->offset;
378		sg_bytes = min(sg_bytes, (size_t)
379			       (PAGE_SIZE - (off & ~PAGE_MASK)));
380		page_addr = kmap_atomic(sg_page(sg) + (off >> PAGE_SHIFT),
381					KM_SOFTIRQ0);
382		if (!page_addr)
383			break;		/* XXX panic? */
384
385		if (fr_flags(fp) & FCPHF_CRC_UNCHECKED)
386			crc = crc32(crc, buf, sg_bytes);
387		memcpy((char *)page_addr + (off & ~PAGE_MASK), buf,
388		       sg_bytes);
389
390		kunmap_atomic(page_addr, KM_SOFTIRQ0);
391		buf += sg_bytes;
392		offset += sg_bytes;
393		remaining -= sg_bytes;
394		copy_len += sg_bytes;
395	}
396
397	if (fr_flags(fp) & FCPHF_CRC_UNCHECKED) {
398		buf = fc_frame_payload_get(fp, 0);
399		if (len % 4) {
400			crc = crc32(crc, buf + len, 4 - (len % 4));
401			len += 4 - (len % 4);
402		}
403
404		if (~crc != le32_to_cpu(fr_crc(fp))) {
405crc_err:
406			stats = fc_lport_get_stats(lp);
407			stats->ErrorFrames++;
408			/* FIXME - per cpu count, not total count! */
409			if (stats->InvalidCRCCount++ < 5)
410				printk(KERN_WARNING "libfc: CRC error on data "
411				       "frame for port (%6x)\n",
412				       fc_host_port_id(lp->host));
413			/*
414			 * Assume the frame is total garbage.
415			 * We may have copied it over the good part
416			 * of the buffer.
417			 * If so, we need to retry the entire operation.
418			 * Otherwise, ignore it.
419			 */
420			if (fsp->state & FC_SRB_DISCONTIG)
421				fc_fcp_retry_cmd(fsp);
422			return;
423		}
424	}
425
426	if (fsp->xfer_contig_end == start_offset)
427		fsp->xfer_contig_end += copy_len;
428	fsp->xfer_len += copy_len;
429
430	/*
431	 * In the very rare event that this data arrived after the response
432	 * and completes the transfer, call the completion handler.
433	 */
434	if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
435	    fsp->xfer_len == fsp->data_len - fsp->scsi_resid)
436		fc_fcp_complete_locked(fsp);
437}
438
439/**
440 * fc_fcp_send_data() -  Send SCSI data to target.
441 * @fsp: ptr to fc_fcp_pkt
442 * @sp: ptr to this sequence
443 * @offset: starting offset for this data request
444 * @seq_blen: the burst length for this data request
445 *
446 * Called after receiving a Transfer Ready data descriptor.
447 * if LLD is capable of seq offload then send down seq_blen
448 * size of data in single frame, otherwise send multiple FC
449 * frames of max FC frame payload supported by target port.
450 *
451 * Returns : 0 for success.
452 */
453static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
454			    size_t offset, size_t seq_blen)
455{
456	struct fc_exch *ep;
457	struct scsi_cmnd *sc;
458	struct scatterlist *sg;
459	struct fc_frame *fp = NULL;
460	struct fc_lport *lp = fsp->lp;
461	size_t remaining;
462	size_t t_blen;
463	size_t tlen;
464	size_t sg_bytes;
465	size_t frame_offset, fh_parm_offset;
466	int error;
467	void *data = NULL;
468	void *page_addr;
469	int using_sg = lp->sg_supp;
470	u32 f_ctl;
471
472	WARN_ON(seq_blen <= 0);
473	if (unlikely(offset + seq_blen > fsp->data_len)) {
474		/* this should never happen */
475		FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
476			   "offset %zx\n", seq_blen, offset);
477		fc_fcp_send_abort(fsp);
478		return 0;
479	} else if (offset != fsp->xfer_len) {
480		/* Out of Order Data Request - no problem, but unexpected. */
481		FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
482			   "seq_blen %zx offset %zx\n", seq_blen, offset);
483	}
484
485	/*
486	 * if LLD is capable of seq_offload then set transport
487	 * burst length (t_blen) to seq_blen, otherwise set t_blen
488	 * to max FC frame payload previously set in fsp->max_payload.
489	 */
490	t_blen = fsp->max_payload;
491	if (lp->seq_offload) {
492		t_blen = min(seq_blen, (size_t)lp->lso_max);
493		FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
494			   fsp, seq_blen, lp->lso_max, t_blen);
495	}
496
497	WARN_ON(t_blen < FC_MIN_MAX_PAYLOAD);
498	if (t_blen > 512)
499		t_blen &= ~(512 - 1);	/* round down to block size */
500	WARN_ON(t_blen < FC_MIN_MAX_PAYLOAD);	/* won't go below 256 */
501	sc = fsp->cmd;
502
503	remaining = seq_blen;
504	fh_parm_offset = frame_offset = offset;
505	tlen = 0;
506	seq = lp->tt.seq_start_next(seq);
507	f_ctl = FC_FC_REL_OFF;
508	WARN_ON(!seq);
509
510	/*
511	 * If a get_page()/put_page() will fail, don't use sg lists
512	 * in the fc_frame structure.
513	 *
514	 * The put_page() may be long after the I/O has completed
515	 * in the case of FCoE, since the network driver does it
516	 * via free_skb().  See the test in free_pages_check().
517	 *
518	 * Test this case with 'dd </dev/zero >/dev/st0 bs=64k'.
519	 */
520	if (using_sg) {
521		for (sg = scsi_sglist(sc); sg; sg = sg_next(sg)) {
522			if (page_count(sg_page(sg)) == 0 ||
523			    (sg_page(sg)->flags & (1 << PG_lru |
524						   1 << PG_private |
525						   1 << PG_locked |
526						   1 << PG_active |
527						   1 << PG_slab |
528						   1 << PG_swapcache |
529						   1 << PG_writeback |
530						   1 << PG_reserved |
531						   1 << PG_buddy))) {
532				using_sg = 0;
533				break;
534			}
535		}
536	}
537	sg = scsi_sglist(sc);
538
539	while (remaining > 0 && sg) {
540		if (offset >= sg->length) {
541			offset -= sg->length;
542			sg = sg_next(sg);
543			continue;
544		}
545		if (!fp) {
546			tlen = min(t_blen, remaining);
547
548			/*
549			 * TODO.  Temporary workaround.	 fc_seq_send() can't
550			 * handle odd lengths in non-linear skbs.
551			 * This will be the final fragment only.
552			 */
553			if (tlen % 4)
554				using_sg = 0;
555			if (using_sg) {
556				fp = _fc_frame_alloc(lp, 0);
557				if (!fp)
558					return -ENOMEM;
559			} else {
560				fp = fc_frame_alloc(lp, tlen);
561				if (!fp)
562					return -ENOMEM;
563
564				data = (void *)(fr_hdr(fp)) +
565					sizeof(struct fc_frame_header);
566			}
567			fh_parm_offset = frame_offset;
568			fr_max_payload(fp) = fsp->max_payload;
569		}
570		sg_bytes = min(tlen, sg->length - offset);
571		if (using_sg) {
572			WARN_ON(skb_shinfo(fp_skb(fp))->nr_frags >
573				FC_FRAME_SG_LEN);
574			get_page(sg_page(sg));
575			skb_fill_page_desc(fp_skb(fp),
576					   skb_shinfo(fp_skb(fp))->nr_frags,
577					   sg_page(sg), sg->offset + offset,
578					   sg_bytes);
579			fp_skb(fp)->data_len += sg_bytes;
580			fr_len(fp) += sg_bytes;
581			fp_skb(fp)->truesize += PAGE_SIZE;
582		} else {
583			size_t off = offset + sg->offset;
584
585			/*
586			 * The scatterlist item may be bigger than PAGE_SIZE,
587			 * but we must not cross pages inside the kmap.
588			 */
589			sg_bytes = min(sg_bytes, (size_t) (PAGE_SIZE -
590							   (off & ~PAGE_MASK)));
591			page_addr = kmap_atomic(sg_page(sg) +
592						(off >> PAGE_SHIFT),
593						KM_SOFTIRQ0);
594			memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
595			       sg_bytes);
596			kunmap_atomic(page_addr, KM_SOFTIRQ0);
597			data += sg_bytes;
598		}
599		offset += sg_bytes;
600		frame_offset += sg_bytes;
601		tlen -= sg_bytes;
602		remaining -= sg_bytes;
603
604		if (tlen)
605			continue;
606
607		/*
608		 * Send sequence with transfer sequence initiative in case
609		 * this is last FCP frame of the sequence.
610		 */
611		if (remaining == 0)
612			f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
613
614		ep = fc_seq_exch(seq);
615		fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
616			       FC_TYPE_FCP, f_ctl, fh_parm_offset);
617
618		/*
619		 * send fragment using for a sequence.
620		 */
621		error = lp->tt.seq_send(lp, seq, fp);
622		if (error) {
623			WARN_ON(1);		/* send error should be rare */
624			fc_fcp_retry_cmd(fsp);
625			return 0;
626		}
627		fp = NULL;
628	}
629	fsp->xfer_len += seq_blen;	/* premature count? */
630	return 0;
631}
632
633static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
634{
635	int ba_done = 1;
636	struct fc_ba_rjt *brp;
637	struct fc_frame_header *fh;
638
639	fh = fc_frame_header_get(fp);
640	switch (fh->fh_r_ctl) {
641	case FC_RCTL_BA_ACC:
642		break;
643	case FC_RCTL_BA_RJT:
644		brp = fc_frame_payload_get(fp, sizeof(*brp));
645		if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
646			break;
647		/* fall thru */
648	default:
649		/*
650		 * we will let the command timeout
651		 * and scsi-ml recover in this case,
652		 * therefore cleared the ba_done flag.
653		 */
654		ba_done = 0;
655	}
656
657	if (ba_done) {
658		fsp->state |= FC_SRB_ABORTED;
659		fsp->state &= ~FC_SRB_ABORT_PENDING;
660
661		if (fsp->wait_for_comp)
662			complete(&fsp->tm_done);
663		else
664			fc_fcp_complete_locked(fsp);
665	}
666}
667
668/**
669 * fc_fcp_reduce_can_queue() - drop can_queue
670 * @lp: lport to drop queueing for
671 *
672 * If we are getting memory allocation failures, then we may
673 * be trying to execute too many commands. We let the running
674 * commands complete or timeout, then try again with a reduced
675 * can_queue. Eventually we will hit the point where we run
676 * on all reserved structs.
677 */
678static void fc_fcp_reduce_can_queue(struct fc_lport *lp)
679{
680	struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
681	unsigned long flags;
682	int can_queue;
683
684	spin_lock_irqsave(lp->host->host_lock, flags);
685	if (si->throttled)
686		goto done;
687	si->throttled = 1;
688
689	can_queue = lp->host->can_queue;
690	can_queue >>= 1;
691	if (!can_queue)
692		can_queue = 1;
693	lp->host->can_queue = can_queue;
694	shost_printk(KERN_ERR, lp->host, "libfc: Could not allocate frame.\n"
695		     "Reducing can_queue to %d.\n", can_queue);
696done:
697	spin_unlock_irqrestore(lp->host->host_lock, flags);
698}
699
700/**
701 * fc_fcp_recv() - Reveive FCP frames
702 * @seq: The sequence the frame is on
703 * @fp: The FC frame
704 * @arg: The related FCP packet
705 *
706 * Return   : None
707 * Context  : called from Soft IRQ context
708 *	      can not called holding list lock
709 */
710static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
711{
712	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
713	struct fc_lport *lport = fsp->lp;
714	struct fc_frame_header *fh;
715	struct fcp_txrdy *dd;
716	u8 r_ctl;
717	int rc = 0;
718
719	if (IS_ERR(fp))
720		goto errout;
721
722	fh = fc_frame_header_get(fp);
723	r_ctl = fh->fh_r_ctl;
724
725	if (!(lport->state & LPORT_ST_READY))
726		goto out;
727	if (fc_fcp_lock_pkt(fsp))
728		goto out;
729	fsp->last_pkt_time = jiffies;
730
731	if (fh->fh_type == FC_TYPE_BLS) {
732		fc_fcp_abts_resp(fsp, fp);
733		goto unlock;
734	}
735
736	if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING))
737		goto unlock;
738
739	if (r_ctl == FC_RCTL_DD_DATA_DESC) {
740		/*
741		 * received XFER RDY from the target
742		 * need to send data to the target
743		 */
744		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
745		dd = fc_frame_payload_get(fp, sizeof(*dd));
746		WARN_ON(!dd);
747
748		rc = fc_fcp_send_data(fsp, seq,
749				      (size_t) ntohl(dd->ft_data_ro),
750				      (size_t) ntohl(dd->ft_burst_len));
751		if (!rc)
752			seq->rec_data = fsp->xfer_len;
753		else if (rc == -ENOMEM)
754			fsp->state |= FC_SRB_NOMEM;
755	} else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
756		/*
757		 * received a DATA frame
758		 * next we will copy the data to the system buffer
759		 */
760		WARN_ON(fr_len(fp) < sizeof(*fh));	/* len may be 0 */
761		fc_fcp_recv_data(fsp, fp);
762		seq->rec_data = fsp->xfer_contig_end;
763	} else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
764		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
765
766		fc_fcp_resp(fsp, fp);
767	} else {
768		FC_FCP_DBG(fsp, "unexpected frame.  r_ctl %x\n", r_ctl);
769	}
770unlock:
771	fc_fcp_unlock_pkt(fsp);
772out:
773	fc_frame_free(fp);
774errout:
775	if (IS_ERR(fp))
776		fc_fcp_error(fsp, fp);
777	else if (rc == -ENOMEM)
778		fc_fcp_reduce_can_queue(lport);
779}
780
781static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
782{
783	struct fc_frame_header *fh;
784	struct fcp_resp *fc_rp;
785	struct fcp_resp_ext *rp_ex;
786	struct fcp_resp_rsp_info *fc_rp_info;
787	u32 plen;
788	u32 expected_len;
789	u32 respl = 0;
790	u32 snsl = 0;
791	u8 flags = 0;
792
793	plen = fr_len(fp);
794	fh = (struct fc_frame_header *)fr_hdr(fp);
795	if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
796		goto len_err;
797	plen -= sizeof(*fh);
798	fc_rp = (struct fcp_resp *)(fh + 1);
799	fsp->cdb_status = fc_rp->fr_status;
800	flags = fc_rp->fr_flags;
801	fsp->scsi_comp_flags = flags;
802	expected_len = fsp->data_len;
803
804	/* if ddp, update xfer len */
805	fc_fcp_ddp_done(fsp);
806
807	if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
808		rp_ex = (void *)(fc_rp + 1);
809		if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
810			if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
811				goto len_err;
812			fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
813			if (flags & FCP_RSP_LEN_VAL) {
814				respl = ntohl(rp_ex->fr_rsp_len);
815				if (respl != sizeof(*fc_rp_info))
816					goto len_err;
817				if (fsp->wait_for_comp) {
818					/* Abuse cdb_status for rsp code */
819					fsp->cdb_status = fc_rp_info->rsp_code;
820					complete(&fsp->tm_done);
821					/*
822					 * tmfs will not have any scsi cmd so
823					 * exit here
824					 */
825					return;
826				} else
827					goto err;
828			}
829			if (flags & FCP_SNS_LEN_VAL) {
830				snsl = ntohl(rp_ex->fr_sns_len);
831				if (snsl > SCSI_SENSE_BUFFERSIZE)
832					snsl = SCSI_SENSE_BUFFERSIZE;
833				memcpy(fsp->cmd->sense_buffer,
834				       (char *)fc_rp_info + respl, snsl);
835			}
836		}
837		if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
838			if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
839				goto len_err;
840			if (flags & FCP_RESID_UNDER) {
841				fsp->scsi_resid = ntohl(rp_ex->fr_resid);
842				/*
843				 * The cmnd->underflow is the minimum number of
844				 * bytes that must be transfered for this
845				 * command.  Provided a sense condition is not
846				 * present, make sure the actual amount
847				 * transferred is at least the underflow value
848				 * or fail.
849				 */
850				if (!(flags & FCP_SNS_LEN_VAL) &&
851				    (fc_rp->fr_status == 0) &&
852				    (scsi_bufflen(fsp->cmd) -
853				     fsp->scsi_resid) < fsp->cmd->underflow)
854					goto err;
855				expected_len -= fsp->scsi_resid;
856			} else {
857				fsp->status_code = FC_ERROR;
858			}
859		}
860	}
861	fsp->state |= FC_SRB_RCV_STATUS;
862
863	/*
864	 * Check for missing or extra data frames.
865	 */
866	if (unlikely(fsp->xfer_len != expected_len)) {
867		if (fsp->xfer_len < expected_len) {
868			/*
869			 * Some data may be queued locally,
870			 * Wait a at least one jiffy to see if it is delivered.
871			 * If this expires without data, we may do SRR.
872			 */
873			fc_fcp_timer_set(fsp, 2);
874			return;
875		}
876		fsp->status_code = FC_DATA_OVRRUN;
877		FC_FCP_DBG(fsp, "tgt %6x xfer len %zx greater than expected, "
878			   "len %x, data len %x\n",
879			   fsp->rport->port_id,
880			   fsp->xfer_len, expected_len, fsp->data_len);
881	}
882	fc_fcp_complete_locked(fsp);
883	return;
884
885len_err:
886	FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
887		   "snsl %u\n", flags, fr_len(fp), respl, snsl);
888err:
889	fsp->status_code = FC_ERROR;
890	fc_fcp_complete_locked(fsp);
891}
892
893/**
894 * fc_fcp_complete_locked() - complete processing of a fcp packet
895 * @fsp:	fcp packet
896 *
897 * This function may sleep if a timer is pending. The packet lock must be
898 * held, and the host lock must not be held.
899 */
900static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
901{
902	struct fc_lport *lp = fsp->lp;
903	struct fc_seq *seq;
904	struct fc_exch *ep;
905	u32 f_ctl;
906
907	if (fsp->state & FC_SRB_ABORT_PENDING)
908		return;
909
910	if (fsp->state & FC_SRB_ABORTED) {
911		if (!fsp->status_code)
912			fsp->status_code = FC_CMD_ABORTED;
913	} else {
914		/*
915		 * Test for transport underrun, independent of response
916		 * underrun status.
917		 */
918		if (fsp->xfer_len < fsp->data_len && !fsp->io_status &&
919		    (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
920		     fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
921			fsp->status_code = FC_DATA_UNDRUN;
922			fsp->io_status = 0;
923		}
924	}
925
926	seq = fsp->seq_ptr;
927	if (seq) {
928		fsp->seq_ptr = NULL;
929		if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
930			struct fc_frame *conf_frame;
931			struct fc_seq *csp;
932
933			csp = lp->tt.seq_start_next(seq);
934			conf_frame = fc_frame_alloc(fsp->lp, 0);
935			if (conf_frame) {
936				f_ctl = FC_FC_SEQ_INIT;
937				f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
938				ep = fc_seq_exch(seq);
939				fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
940					       ep->did, ep->sid,
941					       FC_TYPE_FCP, f_ctl, 0);
942				lp->tt.seq_send(lp, csp, conf_frame);
943			}
944		}
945		lp->tt.exch_done(seq);
946	}
947	fc_io_compl(fsp);
948}
949
950static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
951{
952	struct fc_lport *lp = fsp->lp;
953
954	if (fsp->seq_ptr) {
955		lp->tt.exch_done(fsp->seq_ptr);
956		fsp->seq_ptr = NULL;
957	}
958	fsp->status_code = error;
959}
960
961/**
962 * fc_fcp_cleanup_each_cmd() - Cleanup active commads
963 * @lp:		logical port
964 * @id:		target id
965 * @lun:	lun
966 * @error:	fsp status code
967 *
968 * If lun or id is -1, they are ignored.
969 */
970static void fc_fcp_cleanup_each_cmd(struct fc_lport *lp, unsigned int id,
971				    unsigned int lun, int error)
972{
973	struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
974	struct fc_fcp_pkt *fsp;
975	struct scsi_cmnd *sc_cmd;
976	unsigned long flags;
977
978	spin_lock_irqsave(lp->host->host_lock, flags);
979restart:
980	list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
981		sc_cmd = fsp->cmd;
982		if (id != -1 && scmd_id(sc_cmd) != id)
983			continue;
984
985		if (lun != -1 && sc_cmd->device->lun != lun)
986			continue;
987
988		fc_fcp_pkt_hold(fsp);
989		spin_unlock_irqrestore(lp->host->host_lock, flags);
990
991		if (!fc_fcp_lock_pkt(fsp)) {
992			fc_fcp_cleanup_cmd(fsp, error);
993			fc_io_compl(fsp);
994			fc_fcp_unlock_pkt(fsp);
995		}
996
997		fc_fcp_pkt_release(fsp);
998		spin_lock_irqsave(lp->host->host_lock, flags);
999		/*
1000		 * while we dropped the lock multiple pkts could
1001		 * have been released, so we have to start over.
1002		 */
1003		goto restart;
1004	}
1005	spin_unlock_irqrestore(lp->host->host_lock, flags);
1006}
1007
1008static void fc_fcp_abort_io(struct fc_lport *lp)
1009{
1010	fc_fcp_cleanup_each_cmd(lp, -1, -1, FC_HRD_ERROR);
1011}
1012
1013/**
1014 * fc_fcp_pkt_send() - send a fcp packet to the lower level.
1015 * @lp:		fc lport
1016 * @fsp:	fc packet.
1017 *
1018 * This is called by upper layer protocol.
1019 * Return   : zero for success and -1 for failure
1020 * Context  : called from queuecommand which can be called from process
1021 *	      or scsi soft irq.
1022 * Locks    : called with the host lock and irqs disabled.
1023 */
1024static int fc_fcp_pkt_send(struct fc_lport *lp, struct fc_fcp_pkt *fsp)
1025{
1026	struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
1027	int rc;
1028
1029	fsp->cmd->SCp.ptr = (char *)fsp;
1030	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1031	fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
1032
1033	int_to_scsilun(fsp->cmd->device->lun,
1034		       (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
1035	memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
1036	list_add_tail(&fsp->list, &si->scsi_pkt_queue);
1037
1038	spin_unlock_irq(lp->host->host_lock);
1039	rc = lp->tt.fcp_cmd_send(lp, fsp, fc_fcp_recv);
1040	spin_lock_irq(lp->host->host_lock);
1041	if (rc)
1042		list_del(&fsp->list);
1043
1044	return rc;
1045}
1046
1047static int fc_fcp_cmd_send(struct fc_lport *lp, struct fc_fcp_pkt *fsp,
1048			   void (*resp)(struct fc_seq *,
1049					struct fc_frame *fp,
1050					void *arg))
1051{
1052	struct fc_frame *fp;
1053	struct fc_seq *seq;
1054	struct fc_rport *rport;
1055	struct fc_rport_libfc_priv *rp;
1056	const size_t len = sizeof(fsp->cdb_cmd);
1057	int rc = 0;
1058
1059	if (fc_fcp_lock_pkt(fsp))
1060		return 0;
1061
1062	fp = fc_frame_alloc(lp, sizeof(fsp->cdb_cmd));
1063	if (!fp) {
1064		rc = -1;
1065		goto unlock;
1066	}
1067
1068	memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
1069	fr_fsp(fp) = fsp;
1070	rport = fsp->rport;
1071	fsp->max_payload = rport->maxframe_size;
1072	rp = rport->dd_data;
1073
1074	fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
1075		       fc_host_port_id(rp->local_port->host), FC_TYPE_FCP,
1076		       FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1077
1078	seq = lp->tt.exch_seq_send(lp, fp, resp, fc_fcp_pkt_destroy, fsp, 0);
1079	if (!seq) {
1080		fc_frame_free(fp);
1081		rc = -1;
1082		goto unlock;
1083	}
1084	fsp->last_pkt_time = jiffies;
1085	fsp->seq_ptr = seq;
1086	fc_fcp_pkt_hold(fsp);	/* hold for fc_fcp_pkt_destroy */
1087
1088	setup_timer(&fsp->timer, fc_fcp_timeout, (unsigned long)fsp);
1089	fc_fcp_timer_set(fsp,
1090			 (fsp->tgt_flags & FC_RP_FLAGS_REC_SUPPORTED) ?
1091			 FC_SCSI_REC_TOV : FC_SCSI_ER_TIMEOUT);
1092unlock:
1093	fc_fcp_unlock_pkt(fsp);
1094	return rc;
1095}
1096
1097/*
1098 * transport error handler
1099 */
1100static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1101{
1102	int error = PTR_ERR(fp);
1103
1104	if (fc_fcp_lock_pkt(fsp))
1105		return;
1106
1107	if (error == -FC_EX_CLOSED) {
1108		fc_fcp_retry_cmd(fsp);
1109		goto unlock;
1110	}
1111
1112	/*
1113	 * clear abort pending, because the lower layer
1114	 * decided to force completion.
1115	 */
1116	fsp->state &= ~FC_SRB_ABORT_PENDING;
1117	fsp->status_code = FC_CMD_PLOGO;
1118	fc_fcp_complete_locked(fsp);
1119unlock:
1120	fc_fcp_unlock_pkt(fsp);
1121}
1122
1123/*
1124 * Scsi abort handler- calls to send an abort
1125 * and then wait for abort completion
1126 */
1127static int fc_fcp_pkt_abort(struct fc_lport *lp, struct fc_fcp_pkt *fsp)
1128{
1129	int rc = FAILED;
1130
1131	if (fc_fcp_send_abort(fsp))
1132		return FAILED;
1133
1134	init_completion(&fsp->tm_done);
1135	fsp->wait_for_comp = 1;
1136
1137	spin_unlock_bh(&fsp->scsi_pkt_lock);
1138	rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1139	spin_lock_bh(&fsp->scsi_pkt_lock);
1140	fsp->wait_for_comp = 0;
1141
1142	if (!rc) {
1143		FC_FCP_DBG(fsp, "target abort cmd  failed\n");
1144		rc = FAILED;
1145	} else if (fsp->state & FC_SRB_ABORTED) {
1146		FC_FCP_DBG(fsp, "target abort cmd  passed\n");
1147		rc = SUCCESS;
1148		fc_fcp_complete_locked(fsp);
1149	}
1150
1151	return rc;
1152}
1153
1154/*
1155 * Retry LUN reset after resource allocation failed.
1156 */
1157static void fc_lun_reset_send(unsigned long data)
1158{
1159	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1160	struct fc_lport *lp = fsp->lp;
1161	if (lp->tt.fcp_cmd_send(lp, fsp, fc_tm_done)) {
1162		if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
1163			return;
1164		if (fc_fcp_lock_pkt(fsp))
1165			return;
1166		setup_timer(&fsp->timer, fc_lun_reset_send, (unsigned long)fsp);
1167		fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1168		fc_fcp_unlock_pkt(fsp);
1169	}
1170}
1171
1172/*
1173 * Scsi device reset handler- send a LUN RESET to the device
1174 * and wait for reset reply
1175 */
1176static int fc_lun_reset(struct fc_lport *lp, struct fc_fcp_pkt *fsp,
1177			unsigned int id, unsigned int lun)
1178{
1179	int rc;
1180
1181	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1182	fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
1183	int_to_scsilun(lun, (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
1184
1185	fsp->wait_for_comp = 1;
1186	init_completion(&fsp->tm_done);
1187
1188	fc_lun_reset_send((unsigned long)fsp);
1189
1190	/*
1191	 * wait for completion of reset
1192	 * after that make sure all commands are terminated
1193	 */
1194	rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1195
1196	spin_lock_bh(&fsp->scsi_pkt_lock);
1197	fsp->state |= FC_SRB_COMPL;
1198	spin_unlock_bh(&fsp->scsi_pkt_lock);
1199
1200	del_timer_sync(&fsp->timer);
1201
1202	spin_lock_bh(&fsp->scsi_pkt_lock);
1203	if (fsp->seq_ptr) {
1204		lp->tt.exch_done(fsp->seq_ptr);
1205		fsp->seq_ptr = NULL;
1206	}
1207	fsp->wait_for_comp = 0;
1208	spin_unlock_bh(&fsp->scsi_pkt_lock);
1209
1210	if (!rc) {
1211		FC_SCSI_DBG(lp, "lun reset failed\n");
1212		return FAILED;
1213	}
1214
1215	/* cdb_status holds the tmf's rsp code */
1216	if (fsp->cdb_status != FCP_TMF_CMPL)
1217		return FAILED;
1218
1219	FC_SCSI_DBG(lp, "lun reset to lun %u completed\n", lun);
1220	fc_fcp_cleanup_each_cmd(lp, id, lun, FC_CMD_ABORTED);
1221	return SUCCESS;
1222}
1223
1224/*
1225 * Task Managment response handler
1226 */
1227static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1228{
1229	struct fc_fcp_pkt *fsp = arg;
1230	struct fc_frame_header *fh;
1231
1232	if (IS_ERR(fp)) {
1233		/*
1234		 * If there is an error just let it timeout or wait
1235		 * for TMF to be aborted if it timedout.
1236		 *
1237		 * scsi-eh will escalate for when either happens.
1238		 */
1239		return;
1240	}
1241
1242	if (fc_fcp_lock_pkt(fsp))
1243		return;
1244
1245	/*
1246	 * raced with eh timeout handler.
1247	 */
1248	if (!fsp->seq_ptr || !fsp->wait_for_comp) {
1249		spin_unlock_bh(&fsp->scsi_pkt_lock);
1250		return;
1251	}
1252
1253	fh = fc_frame_header_get(fp);
1254	if (fh->fh_type != FC_TYPE_BLS)
1255		fc_fcp_resp(fsp, fp);
1256	fsp->seq_ptr = NULL;
1257	fsp->lp->tt.exch_done(seq);
1258	fc_frame_free(fp);
1259	fc_fcp_unlock_pkt(fsp);
1260}
1261
1262static void fc_fcp_cleanup(struct fc_lport *lp)
1263{
1264	fc_fcp_cleanup_each_cmd(lp, -1, -1, FC_ERROR);
1265}
1266
1267/*
1268 * fc_fcp_timeout: called by OS timer function.
1269 *
1270 * The timer has been inactivated and must be reactivated if desired
1271 * using fc_fcp_timer_set().
1272 *
1273 * Algorithm:
1274 *
1275 * If REC is supported, just issue it, and return.  The REC exchange will
1276 * complete or time out, and recovery can continue at that point.
1277 *
1278 * Otherwise, if the response has been received without all the data,
1279 * it has been ER_TIMEOUT since the response was received.
1280 *
1281 * If the response has not been received,
1282 * we see if data was received recently.  If it has been, we continue waiting,
1283 * otherwise, we abort the command.
1284 */
1285static void fc_fcp_timeout(unsigned long data)
1286{
1287	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1288	struct fc_rport *rport = fsp->rport;
1289	struct fc_rport_libfc_priv *rp = rport->dd_data;
1290
1291	if (fc_fcp_lock_pkt(fsp))
1292		return;
1293
1294	if (fsp->cdb_cmd.fc_tm_flags)
1295		goto unlock;
1296
1297	fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
1298
1299	if (rp->flags & FC_RP_FLAGS_REC_SUPPORTED)
1300		fc_fcp_rec(fsp);
1301	else if (time_after_eq(fsp->last_pkt_time + (FC_SCSI_ER_TIMEOUT / 2),
1302			       jiffies))
1303		fc_fcp_timer_set(fsp, FC_SCSI_ER_TIMEOUT);
1304	else if (fsp->state & FC_SRB_RCV_STATUS)
1305		fc_fcp_complete_locked(fsp);
1306	else
1307		fc_timeout_error(fsp);
1308	fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
1309unlock:
1310	fc_fcp_unlock_pkt(fsp);
1311}
1312
1313/*
1314 * Send a REC ELS request
1315 */
1316static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
1317{
1318	struct fc_lport *lp;
1319	struct fc_frame *fp;
1320	struct fc_rport *rport;
1321	struct fc_rport_libfc_priv *rp;
1322
1323	lp = fsp->lp;
1324	rport = fsp->rport;
1325	rp = rport->dd_data;
1326	if (!fsp->seq_ptr || rp->rp_state != RPORT_ST_READY) {
1327		fsp->status_code = FC_HRD_ERROR;
1328		fsp->io_status = 0;
1329		fc_fcp_complete_locked(fsp);
1330		return;
1331	}
1332	fp = fc_frame_alloc(lp, sizeof(struct fc_els_rec));
1333	if (!fp)
1334		goto retry;
1335
1336	fr_seq(fp) = fsp->seq_ptr;
1337	fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
1338		       fc_host_port_id(rp->local_port->host), FC_TYPE_ELS,
1339		       FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1340	if (lp->tt.elsct_send(lp, rport, fp, ELS_REC, fc_fcp_rec_resp,
1341			      fsp, jiffies_to_msecs(FC_SCSI_REC_TOV))) {
1342		fc_fcp_pkt_hold(fsp);		/* hold while REC outstanding */
1343		return;
1344	}
1345	fc_frame_free(fp);
1346retry:
1347	if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1348		fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1349	else
1350		fc_timeout_error(fsp);
1351}
1352
1353/*
1354 * Receive handler for REC ELS frame
1355 * if it is a reject then let the scsi layer to handle
1356 * the timeout. if it is a LS_ACC then if the io was not completed
1357 * then set the timeout and return otherwise complete the exchange
1358 * and tell the scsi layer to restart the I/O.
1359 */
1360static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1361{
1362	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
1363	struct fc_els_rec_acc *recp;
1364	struct fc_els_ls_rjt *rjt;
1365	u32 e_stat;
1366	u8 opcode;
1367	u32 offset;
1368	enum dma_data_direction data_dir;
1369	enum fc_rctl r_ctl;
1370	struct fc_rport_libfc_priv *rp;
1371
1372	if (IS_ERR(fp)) {
1373		fc_fcp_rec_error(fsp, fp);
1374		return;
1375	}
1376
1377	if (fc_fcp_lock_pkt(fsp))
1378		goto out;
1379
1380	fsp->recov_retry = 0;
1381	opcode = fc_frame_payload_op(fp);
1382	if (opcode == ELS_LS_RJT) {
1383		rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1384		switch (rjt->er_reason) {
1385		default:
1386			FC_FCP_DBG(fsp, "device %x unexpected REC reject "
1387				   "reason %d expl %d\n",
1388				   fsp->rport->port_id, rjt->er_reason,
1389				   rjt->er_explan);
1390			/* fall through */
1391		case ELS_RJT_UNSUP:
1392			FC_FCP_DBG(fsp, "device does not support REC\n");
1393			rp = fsp->rport->dd_data;
1394			/*
1395			 * if we do not spport RECs or got some bogus
1396			 * reason then resetup timer so we check for
1397			 * making progress.
1398			 */
1399			rp->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
1400			fc_fcp_timer_set(fsp, FC_SCSI_ER_TIMEOUT);
1401			break;
1402		case ELS_RJT_LOGIC:
1403		case ELS_RJT_UNAB:
1404			/*
1405			 * If no data transfer, the command frame got dropped
1406			 * so we just retry.  If data was transferred, we
1407			 * lost the response but the target has no record,
1408			 * so we abort and retry.
1409			 */
1410			if (rjt->er_explan == ELS_EXPL_OXID_RXID &&
1411			    fsp->xfer_len == 0) {
1412				fc_fcp_retry_cmd(fsp);
1413				break;
1414			}
1415			fc_timeout_error(fsp);
1416			break;
1417		}
1418	} else if (opcode == ELS_LS_ACC) {
1419		if (fsp->state & FC_SRB_ABORTED)
1420			goto unlock_out;
1421
1422		data_dir = fsp->cmd->sc_data_direction;
1423		recp = fc_frame_payload_get(fp, sizeof(*recp));
1424		offset = ntohl(recp->reca_fc4value);
1425		e_stat = ntohl(recp->reca_e_stat);
1426
1427		if (e_stat & ESB_ST_COMPLETE) {
1428
1429			/*
1430			 * The exchange is complete.
1431			 *
1432			 * For output, we must've lost the response.
1433			 * For input, all data must've been sent.
1434			 * We lost may have lost the response
1435			 * (and a confirmation was requested) and maybe
1436			 * some data.
1437			 *
1438			 * If all data received, send SRR
1439			 * asking for response.	 If partial data received,
1440			 * or gaps, SRR requests data at start of gap.
1441			 * Recovery via SRR relies on in-order-delivery.
1442			 */
1443			if (data_dir == DMA_TO_DEVICE) {
1444				r_ctl = FC_RCTL_DD_CMD_STATUS;
1445			} else if (fsp->xfer_contig_end == offset) {
1446				r_ctl = FC_RCTL_DD_CMD_STATUS;
1447			} else {
1448				offset = fsp->xfer_contig_end;
1449				r_ctl = FC_RCTL_DD_SOL_DATA;
1450			}
1451			fc_fcp_srr(fsp, r_ctl, offset);
1452		} else if (e_stat & ESB_ST_SEQ_INIT) {
1453
1454			/*
1455			 * The remote port has the initiative, so just
1456			 * keep waiting for it to complete.
1457			 */
1458			fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1459		} else {
1460
1461			/*
1462			 * The exchange is incomplete, we have seq. initiative.
1463			 * Lost response with requested confirmation,
1464			 * lost confirmation, lost transfer ready or
1465			 * lost write data.
1466			 *
1467			 * For output, if not all data was received, ask
1468			 * for transfer ready to be repeated.
1469			 *
1470			 * If we received or sent all the data, send SRR to
1471			 * request response.
1472			 *
1473			 * If we lost a response, we may have lost some read
1474			 * data as well.
1475			 */
1476			r_ctl = FC_RCTL_DD_SOL_DATA;
1477			if (data_dir == DMA_TO_DEVICE) {
1478				r_ctl = FC_RCTL_DD_CMD_STATUS;
1479				if (offset < fsp->data_len)
1480					r_ctl = FC_RCTL_DD_DATA_DESC;
1481			} else if (offset == fsp->xfer_contig_end) {
1482				r_ctl = FC_RCTL_DD_CMD_STATUS;
1483			} else if (fsp->xfer_contig_end < offset) {
1484				offset = fsp->xfer_contig_end;
1485			}
1486			fc_fcp_srr(fsp, r_ctl, offset);
1487		}
1488	}
1489unlock_out:
1490	fc_fcp_unlock_pkt(fsp);
1491out:
1492	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
1493	fc_frame_free(fp);
1494}
1495
1496/*
1497 * Handle error response or timeout for REC exchange.
1498 */
1499static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1500{
1501	int error = PTR_ERR(fp);
1502
1503	if (fc_fcp_lock_pkt(fsp))
1504		goto out;
1505
1506	switch (error) {
1507	case -FC_EX_CLOSED:
1508		fc_fcp_retry_cmd(fsp);
1509		break;
1510
1511	default:
1512		FC_FCP_DBG(fsp, "REC %p fid %x error unexpected error %d\n",
1513			   fsp, fsp->rport->port_id, error);
1514		fsp->status_code = FC_CMD_PLOGO;
1515		/* fall through */
1516
1517	case -FC_EX_TIMEOUT:
1518		/*
1519		 * Assume REC or LS_ACC was lost.
1520		 * The exchange manager will have aborted REC, so retry.
1521		 */
1522		FC_FCP_DBG(fsp, "REC fid %x error error %d retry %d/%d\n",
1523			   fsp->rport->port_id, error, fsp->recov_retry,
1524			   FC_MAX_RECOV_RETRY);
1525		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1526			fc_fcp_rec(fsp);
1527		else
1528			fc_timeout_error(fsp);
1529		break;
1530	}
1531	fc_fcp_unlock_pkt(fsp);
1532out:
1533	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
1534}
1535
1536/*
1537 * Time out error routine:
1538 * abort's the I/O close the exchange and
1539 * send completion notification to scsi layer
1540 */
1541static void fc_timeout_error(struct fc_fcp_pkt *fsp)
1542{
1543	fsp->status_code = FC_CMD_TIME_OUT;
1544	fsp->cdb_status = 0;
1545	fsp->io_status = 0;
1546	/*
1547	 * if this fails then we let the scsi command timer fire and
1548	 * scsi-ml escalate.
1549	 */
1550	fc_fcp_send_abort(fsp);
1551}
1552
1553/*
1554 * Sequence retransmission request.
1555 * This is called after receiving status but insufficient data, or
1556 * when expecting status but the request has timed out.
1557 */
1558static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
1559{
1560	struct fc_lport *lp = fsp->lp;
1561	struct fc_rport *rport;
1562	struct fc_rport_libfc_priv *rp;
1563	struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1564	struct fc_seq *seq;
1565	struct fcp_srr *srr;
1566	struct fc_frame *fp;
1567	u8 cdb_op;
1568
1569	rport = fsp->rport;
1570	rp = rport->dd_data;
1571	cdb_op = fsp->cdb_cmd.fc_cdb[0];
1572
1573	if (!(rp->flags & FC_RP_FLAGS_RETRY) || rp->rp_state != RPORT_ST_READY)
1574		goto retry;			/* shouldn't happen */
1575	fp = fc_frame_alloc(lp, sizeof(*srr));
1576	if (!fp)
1577		goto retry;
1578
1579	srr = fc_frame_payload_get(fp, sizeof(*srr));
1580	memset(srr, 0, sizeof(*srr));
1581	srr->srr_op = ELS_SRR;
1582	srr->srr_ox_id = htons(ep->oxid);
1583	srr->srr_rx_id = htons(ep->rxid);
1584	srr->srr_r_ctl = r_ctl;
1585	srr->srr_rel_off = htonl(offset);
1586
1587	fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
1588		       fc_host_port_id(rp->local_port->host), FC_TYPE_FCP,
1589		       FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
1590
1591	seq = lp->tt.exch_seq_send(lp, fp, fc_fcp_srr_resp, NULL,
1592				   fsp, jiffies_to_msecs(FC_SCSI_REC_TOV));
1593	if (!seq) {
1594		fc_frame_free(fp);
1595		goto retry;
1596	}
1597	fsp->recov_seq = seq;
1598	fsp->xfer_len = offset;
1599	fsp->xfer_contig_end = offset;
1600	fsp->state &= ~FC_SRB_RCV_STATUS;
1601	fc_fcp_pkt_hold(fsp);		/* hold for outstanding SRR */
1602	return;
1603retry:
1604	fc_fcp_retry_cmd(fsp);
1605}
1606
1607/*
1608 * Handle response from SRR.
1609 */
1610static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1611{
1612	struct fc_fcp_pkt *fsp = arg;
1613	struct fc_frame_header *fh;
1614
1615	if (IS_ERR(fp)) {
1616		fc_fcp_srr_error(fsp, fp);
1617		return;
1618	}
1619
1620	if (fc_fcp_lock_pkt(fsp))
1621		goto out;
1622
1623	fh = fc_frame_header_get(fp);
1624	/*
1625	 * BUG? fc_fcp_srr_error calls exch_done which would release
1626	 * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
1627	 * then fc_exch_timeout would be sending an abort. The exch_done
1628	 * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
1629	 * an abort response though.
1630	 */
1631	if (fh->fh_type == FC_TYPE_BLS) {
1632		fc_fcp_unlock_pkt(fsp);
1633		return;
1634	}
1635
1636	fsp->recov_seq = NULL;
1637	switch (fc_frame_payload_op(fp)) {
1638	case ELS_LS_ACC:
1639		fsp->recov_retry = 0;
1640		fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
1641		break;
1642	case ELS_LS_RJT:
1643	default:
1644		fc_timeout_error(fsp);
1645		break;
1646	}
1647	fc_fcp_unlock_pkt(fsp);
1648	fsp->lp->tt.exch_done(seq);
1649out:
1650	fc_frame_free(fp);
1651	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding SRR */
1652}
1653
1654static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1655{
1656	if (fc_fcp_lock_pkt(fsp))
1657		goto out;
1658	fsp->lp->tt.exch_done(fsp->recov_seq);
1659	fsp->recov_seq = NULL;
1660	switch (PTR_ERR(fp)) {
1661	case -FC_EX_TIMEOUT:
1662		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1663			fc_fcp_rec(fsp);
1664		else
1665			fc_timeout_error(fsp);
1666		break;
1667	case -FC_EX_CLOSED:			/* e.g., link failure */
1668		/* fall through */
1669	default:
1670		fc_fcp_retry_cmd(fsp);
1671		break;
1672	}
1673	fc_fcp_unlock_pkt(fsp);
1674out:
1675	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding SRR */
1676}
1677
1678static inline int fc_fcp_lport_queue_ready(struct fc_lport *lp)
1679{
1680	/* lock ? */
1681	return (lp->state == LPORT_ST_READY) && lp->link_up && !lp->qfull;
1682}
1683
1684/**
1685 * fc_queuecommand - The queuecommand function of the scsi template
1686 * @cmd:	struct scsi_cmnd to be executed
1687 * @done:	Callback function to be called when cmd is completed
1688 *
1689 * this is the i/o strategy routine, called by the scsi layer
1690 * this routine is called with holding the host_lock.
1691 */
1692int fc_queuecommand(struct scsi_cmnd *sc_cmd, void (*done)(struct scsi_cmnd *))
1693{
1694	struct fc_lport *lp;
1695	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1696	struct fc_fcp_pkt *fsp;
1697	struct fc_rport_libfc_priv *rp;
1698	int rval;
1699	int rc = 0;
1700	struct fcoe_dev_stats *stats;
1701
1702	lp = shost_priv(sc_cmd->device->host);
1703
1704	rval = fc_remote_port_chkready(rport);
1705	if (rval) {
1706		sc_cmd->result = rval;
1707		done(sc_cmd);
1708		goto out;
1709	}
1710
1711	if (!*(struct fc_remote_port **)rport->dd_data) {
1712		/*
1713		 * rport is transitioning from blocked/deleted to
1714		 * online
1715		 */
1716		sc_cmd->result = DID_IMM_RETRY << 16;
1717		done(sc_cmd);
1718		goto out;
1719	}
1720
1721	rp = rport->dd_data;
1722
1723	if (!fc_fcp_lport_queue_ready(lp)) {
1724		rc = SCSI_MLQUEUE_HOST_BUSY;
1725		goto out;
1726	}
1727
1728	fsp = fc_fcp_pkt_alloc(lp, GFP_ATOMIC);
1729	if (fsp == NULL) {
1730		rc = SCSI_MLQUEUE_HOST_BUSY;
1731		goto out;
1732	}
1733
1734	/*
1735	 * build the libfc request pkt
1736	 */
1737	fsp->cmd = sc_cmd;	/* save the cmd */
1738	fsp->lp = lp;		/* save the softc ptr */
1739	fsp->rport = rport;	/* set the remote port ptr */
1740	sc_cmd->scsi_done = done;
1741
1742	/*
1743	 * set up the transfer length
1744	 */
1745	fsp->data_len = scsi_bufflen(sc_cmd);
1746	fsp->xfer_len = 0;
1747
1748	/*
1749	 * setup the data direction
1750	 */
1751	stats = fc_lport_get_stats(lp);
1752	if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
1753		fsp->req_flags = FC_SRB_READ;
1754		stats->InputRequests++;
1755		stats->InputMegabytes = fsp->data_len;
1756	} else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
1757		fsp->req_flags = FC_SRB_WRITE;
1758		stats->OutputRequests++;
1759		stats->OutputMegabytes = fsp->data_len;
1760	} else {
1761		fsp->req_flags = 0;
1762		stats->ControlRequests++;
1763	}
1764
1765	fsp->tgt_flags = rp->flags;
1766
1767	init_timer(&fsp->timer);
1768	fsp->timer.data = (unsigned long)fsp;
1769
1770	/*
1771	 * send it to the lower layer
1772	 * if we get -1 return then put the request in the pending
1773	 * queue.
1774	 */
1775	rval = fc_fcp_pkt_send(lp, fsp);
1776	if (rval != 0) {
1777		fsp->state = FC_SRB_FREE;
1778		fc_fcp_pkt_release(fsp);
1779		rc = SCSI_MLQUEUE_HOST_BUSY;
1780	}
1781out:
1782	return rc;
1783}
1784EXPORT_SYMBOL(fc_queuecommand);
1785
1786/**
1787 * fc_io_compl() -  Handle responses for completed commands
1788 * @fsp:	scsi packet
1789 *
1790 * Translates a error to a Linux SCSI error.
1791 *
1792 * The fcp packet lock must be held when calling.
1793 */
1794static void fc_io_compl(struct fc_fcp_pkt *fsp)
1795{
1796	struct fc_fcp_internal *si;
1797	struct scsi_cmnd *sc_cmd;
1798	struct fc_lport *lp;
1799	unsigned long flags;
1800
1801	/* release outstanding ddp context */
1802	fc_fcp_ddp_done(fsp);
1803
1804	fsp->state |= FC_SRB_COMPL;
1805	if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
1806		spin_unlock_bh(&fsp->scsi_pkt_lock);
1807		del_timer_sync(&fsp->timer);
1808		spin_lock_bh(&fsp->scsi_pkt_lock);
1809	}
1810
1811	lp = fsp->lp;
1812	si = fc_get_scsi_internal(lp);
1813	spin_lock_irqsave(lp->host->host_lock, flags);
1814	if (!fsp->cmd) {
1815		spin_unlock_irqrestore(lp->host->host_lock, flags);
1816		return;
1817	}
1818
1819	/*
1820	 * if a command timed out while we had to try and throttle IO
1821	 * and it is now getting cleaned up, then we are about to
1822	 * try again so clear the throttled flag incase we get more
1823	 * time outs.
1824	 */
1825	if (si->throttled && fsp->state & FC_SRB_NOMEM)
1826		si->throttled = 0;
1827
1828	sc_cmd = fsp->cmd;
1829	fsp->cmd = NULL;
1830
1831	if (!sc_cmd->SCp.ptr) {
1832		spin_unlock_irqrestore(lp->host->host_lock, flags);
1833		return;
1834	}
1835
1836	CMD_SCSI_STATUS(sc_cmd) = fsp->cdb_status;
1837	switch (fsp->status_code) {
1838	case FC_COMPLETE:
1839		if (fsp->cdb_status == 0) {
1840			/*
1841			 * good I/O status
1842			 */
1843			sc_cmd->result = DID_OK << 16;
1844			if (fsp->scsi_resid)
1845				CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1846		} else if (fsp->cdb_status == QUEUE_FULL) {
1847			struct scsi_device *tmp_sdev;
1848			struct scsi_device *sdev = sc_cmd->device;
1849
1850			shost_for_each_device(tmp_sdev, sdev->host) {
1851				if (tmp_sdev->id != sdev->id)
1852					continue;
1853
1854				if (tmp_sdev->queue_depth > 1) {
1855					scsi_track_queue_full(tmp_sdev,
1856							      tmp_sdev->
1857							      queue_depth - 1);
1858				}
1859			}
1860			sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
1861		} else {
1862			/*
1863			 * transport level I/O was ok but scsi
1864			 * has non zero status
1865			 */
1866			sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
1867		}
1868		break;
1869	case FC_ERROR:
1870		sc_cmd->result = DID_ERROR << 16;
1871		break;
1872	case FC_DATA_UNDRUN:
1873		if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) {
1874			/*
1875			 * scsi status is good but transport level
1876			 * underrun.
1877			 */
1878			sc_cmd->result = DID_OK << 16;
1879		} else {
1880			/*
1881			 * scsi got underrun, this is an error
1882			 */
1883			CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1884			sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1885		}
1886		break;
1887	case FC_DATA_OVRRUN:
1888		/*
1889		 * overrun is an error
1890		 */
1891		sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1892		break;
1893	case FC_CMD_ABORTED:
1894		sc_cmd->result = (DID_ERROR << 16) | fsp->io_status;
1895		break;
1896	case FC_CMD_TIME_OUT:
1897		sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
1898		break;
1899	case FC_CMD_RESET:
1900		sc_cmd->result = (DID_RESET << 16);
1901		break;
1902	case FC_HRD_ERROR:
1903		sc_cmd->result = (DID_NO_CONNECT << 16);
1904		break;
1905	default:
1906		sc_cmd->result = (DID_ERROR << 16);
1907		break;
1908	}
1909
1910	list_del(&fsp->list);
1911	sc_cmd->SCp.ptr = NULL;
1912	sc_cmd->scsi_done(sc_cmd);
1913	spin_unlock_irqrestore(lp->host->host_lock, flags);
1914
1915	/* release ref from initial allocation in queue command */
1916	fc_fcp_pkt_release(fsp);
1917}
1918
1919/**
1920 * fc_fcp_complete() - complete processing of a fcp packet
1921 * @fsp:	fcp packet
1922 *
1923 * This function may sleep if a fsp timer is pending.
1924 * The host lock must not be held by caller.
1925 */
1926void fc_fcp_complete(struct fc_fcp_pkt *fsp)
1927{
1928	if (fc_fcp_lock_pkt(fsp))
1929		return;
1930
1931	fc_fcp_complete_locked(fsp);
1932	fc_fcp_unlock_pkt(fsp);
1933}
1934EXPORT_SYMBOL(fc_fcp_complete);
1935
1936/**
1937 * fc_eh_abort() - Abort a command
1938 * @sc_cmd:	scsi command to abort
1939 *
1940 * From scsi host template.
1941 * send ABTS to the target device  and wait for the response
1942 * sc_cmd is the pointer to the command to be aborted.
1943 */
1944int fc_eh_abort(struct scsi_cmnd *sc_cmd)
1945{
1946	struct fc_fcp_pkt *fsp;
1947	struct fc_lport *lp;
1948	int rc = FAILED;
1949	unsigned long flags;
1950
1951	lp = shost_priv(sc_cmd->device->host);
1952	if (lp->state != LPORT_ST_READY)
1953		return rc;
1954	else if (!lp->link_up)
1955		return rc;
1956
1957	spin_lock_irqsave(lp->host->host_lock, flags);
1958	fsp = CMD_SP(sc_cmd);
1959	if (!fsp) {
1960		/* command completed while scsi eh was setting up */
1961		spin_unlock_irqrestore(lp->host->host_lock, flags);
1962		return SUCCESS;
1963	}
1964	/* grab a ref so the fsp and sc_cmd cannot be relased from under us */
1965	fc_fcp_pkt_hold(fsp);
1966	spin_unlock_irqrestore(lp->host->host_lock, flags);
1967
1968	if (fc_fcp_lock_pkt(fsp)) {
1969		/* completed while we were waiting for timer to be deleted */
1970		rc = SUCCESS;
1971		goto release_pkt;
1972	}
1973
1974	rc = fc_fcp_pkt_abort(lp, fsp);
1975	fc_fcp_unlock_pkt(fsp);
1976
1977release_pkt:
1978	fc_fcp_pkt_release(fsp);
1979	return rc;
1980}
1981EXPORT_SYMBOL(fc_eh_abort);
1982
1983/**
1984 * fc_eh_device_reset() Reset a single LUN
1985 * @sc_cmd:	scsi command
1986 *
1987 * Set from scsi host template to send tm cmd to the target and wait for the
1988 * response.
1989 */
1990int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
1991{
1992	struct fc_lport *lp;
1993	struct fc_fcp_pkt *fsp;
1994	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1995	int rc = FAILED;
1996	struct fc_rport_libfc_priv *rp;
1997	int rval;
1998
1999	rval = fc_remote_port_chkready(rport);
2000	if (rval)
2001		goto out;
2002
2003	rp = rport->dd_data;
2004	lp = shost_priv(sc_cmd->device->host);
2005
2006	if (lp->state != LPORT_ST_READY)
2007		return rc;
2008
2009	FC_SCSI_DBG(lp, "Resetting rport (%6x)\n", rport->port_id);
2010
2011	fsp = fc_fcp_pkt_alloc(lp, GFP_NOIO);
2012	if (fsp == NULL) {
2013		printk(KERN_WARNING "libfc: could not allocate scsi_pkt\n");
2014		sc_cmd->result = DID_NO_CONNECT << 16;
2015		goto out;
2016	}
2017
2018	/*
2019	 * Build the libfc request pkt. Do not set the scsi cmnd, because
2020	 * the sc passed in is not setup for execution like when sent
2021	 * through the queuecommand callout.
2022	 */
2023	fsp->lp = lp;		/* save the softc ptr */
2024	fsp->rport = rport;	/* set the remote port ptr */
2025
2026	/*
2027	 * flush outstanding commands
2028	 */
2029	rc = fc_lun_reset(lp, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
2030	fsp->state = FC_SRB_FREE;
2031	fc_fcp_pkt_release(fsp);
2032
2033out:
2034	return rc;
2035}
2036EXPORT_SYMBOL(fc_eh_device_reset);
2037
2038/**
2039 * fc_eh_host_reset() - The reset function will reset the ports on the host.
2040 * @sc_cmd:	scsi command
2041 */
2042int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
2043{
2044	struct Scsi_Host *shost = sc_cmd->device->host;
2045	struct fc_lport *lp = shost_priv(shost);
2046	unsigned long wait_tmo;
2047
2048	FC_SCSI_DBG(lp, "Resetting host\n");
2049
2050	lp->tt.lport_reset(lp);
2051	wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
2052	while (!fc_fcp_lport_queue_ready(lp) && time_before(jiffies, wait_tmo))
2053		msleep(1000);
2054
2055	if (fc_fcp_lport_queue_ready(lp)) {
2056		shost_printk(KERN_INFO, shost, "libfc: Host reset succeeded "
2057			     "on port (%6x)\n", fc_host_port_id(lp->host));
2058		return SUCCESS;
2059	} else {
2060		shost_printk(KERN_INFO, shost, "libfc: Host reset failed, "
2061			     "port (%6x) is not ready.\n",
2062			     fc_host_port_id(lp->host));
2063		return FAILED;
2064	}
2065}
2066EXPORT_SYMBOL(fc_eh_host_reset);
2067
2068/**
2069 * fc_slave_alloc() - configure queue depth
2070 * @sdev:	scsi device
2071 *
2072 * Configures queue depth based on host's cmd_per_len. If not set
2073 * then we use the libfc default.
2074 */
2075int fc_slave_alloc(struct scsi_device *sdev)
2076{
2077	struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
2078	int queue_depth;
2079
2080	if (!rport || fc_remote_port_chkready(rport))
2081		return -ENXIO;
2082
2083	if (sdev->tagged_supported) {
2084		if (sdev->host->hostt->cmd_per_lun)
2085			queue_depth = sdev->host->hostt->cmd_per_lun;
2086		else
2087			queue_depth = FC_FCP_DFLT_QUEUE_DEPTH;
2088		scsi_activate_tcq(sdev, queue_depth);
2089	}
2090	return 0;
2091}
2092EXPORT_SYMBOL(fc_slave_alloc);
2093
2094int fc_change_queue_depth(struct scsi_device *sdev, int qdepth)
2095{
2096	scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);
2097	return sdev->queue_depth;
2098}
2099EXPORT_SYMBOL(fc_change_queue_depth);
2100
2101int fc_change_queue_type(struct scsi_device *sdev, int tag_type)
2102{
2103	if (sdev->tagged_supported) {
2104		scsi_set_tag_type(sdev, tag_type);
2105		if (tag_type)
2106			scsi_activate_tcq(sdev, sdev->queue_depth);
2107		else
2108			scsi_deactivate_tcq(sdev, sdev->queue_depth);
2109	} else
2110		tag_type = 0;
2111
2112	return tag_type;
2113}
2114EXPORT_SYMBOL(fc_change_queue_type);
2115
2116void fc_fcp_destroy(struct fc_lport *lp)
2117{
2118	struct fc_fcp_internal *si = fc_get_scsi_internal(lp);
2119
2120	if (!list_empty(&si->scsi_pkt_queue))
2121		printk(KERN_ERR "libfc: Leaked SCSI packets when destroying "
2122		       "port (%6x)\n", fc_host_port_id(lp->host));
2123
2124	mempool_destroy(si->scsi_pkt_pool);
2125	kfree(si);
2126	lp->scsi_priv = NULL;
2127}
2128EXPORT_SYMBOL(fc_fcp_destroy);
2129
2130int fc_fcp_init(struct fc_lport *lp)
2131{
2132	int rc;
2133	struct fc_fcp_internal *si;
2134
2135	if (!lp->tt.fcp_cmd_send)
2136		lp->tt.fcp_cmd_send = fc_fcp_cmd_send;
2137
2138	if (!lp->tt.fcp_cleanup)
2139		lp->tt.fcp_cleanup = fc_fcp_cleanup;
2140
2141	if (!lp->tt.fcp_abort_io)
2142		lp->tt.fcp_abort_io = fc_fcp_abort_io;
2143
2144	si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
2145	if (!si)
2146		return -ENOMEM;
2147	lp->scsi_priv = si;
2148	INIT_LIST_HEAD(&si->scsi_pkt_queue);
2149
2150	si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
2151	if (!si->scsi_pkt_pool) {
2152		rc = -ENOMEM;
2153		goto free_internal;
2154	}
2155	return 0;
2156
2157free_internal:
2158	kfree(si);
2159	return rc;
2160}
2161EXPORT_SYMBOL(fc_fcp_init);
2162
2163static int __init libfc_init(void)
2164{
2165	int rc;
2166
2167	scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
2168					    sizeof(struct fc_fcp_pkt),
2169					    0, SLAB_HWCACHE_ALIGN, NULL);
2170	if (scsi_pkt_cachep == NULL) {
2171		printk(KERN_ERR "libfc: Unable to allocate SRB cache, "
2172		       "module load failed!");
2173		return -ENOMEM;
2174	}
2175
2176	rc = fc_setup_exch_mgr();
2177	if (rc)
2178		goto destroy_pkt_cache;
2179
2180	rc = fc_setup_rport();
2181	if (rc)
2182		goto destroy_em;
2183
2184	return rc;
2185destroy_em:
2186	fc_destroy_exch_mgr();
2187destroy_pkt_cache:
2188	kmem_cache_destroy(scsi_pkt_cachep);
2189	return rc;
2190}
2191
2192static void __exit libfc_exit(void)
2193{
2194	kmem_cache_destroy(scsi_pkt_cachep);
2195	fc_destroy_exch_mgr();
2196	fc_destroy_rport();
2197}
2198
2199module_init(libfc_init);
2200module_exit(libfc_exit);
2201