fc_fcp.c revision 05fee645e96e732a79ad083cab8ddd4efd108e2c
1/*
2 * Copyright(c) 2007 Intel Corporation. All rights reserved.
3 * Copyright(c) 2008 Red Hat, Inc.  All rights reserved.
4 * Copyright(c) 2008 Mike Christie
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Maintained at www.Open-FCoE.org
20 */
21
22#include <linux/module.h>
23#include <linux/delay.h>
24#include <linux/kernel.h>
25#include <linux/types.h>
26#include <linux/spinlock.h>
27#include <linux/scatterlist.h>
28#include <linux/err.h>
29#include <linux/crc32.h>
30#include <linux/slab.h>
31
32#include <scsi/scsi_tcq.h>
33#include <scsi/scsi.h>
34#include <scsi/scsi_host.h>
35#include <scsi/scsi_device.h>
36#include <scsi/scsi_cmnd.h>
37
38#include <scsi/fc/fc_fc2.h>
39
40#include <scsi/libfc.h>
41#include <scsi/fc_encode.h>
42
43#include "fc_libfc.h"
44
45struct kmem_cache *scsi_pkt_cachep;
46
47/* SRB state definitions */
48#define FC_SRB_FREE		0		/* cmd is free */
49#define FC_SRB_CMD_SENT		(1 << 0)	/* cmd has been sent */
50#define FC_SRB_RCV_STATUS	(1 << 1)	/* response has arrived */
51#define FC_SRB_ABORT_PENDING	(1 << 2)	/* cmd abort sent to device */
52#define FC_SRB_ABORTED		(1 << 3)	/* abort acknowledged */
53#define FC_SRB_DISCONTIG	(1 << 4)	/* non-sequential data recvd */
54#define FC_SRB_COMPL		(1 << 5)	/* fc_io_compl has been run */
55#define FC_SRB_FCP_PROCESSING_TMO (1 << 6)	/* timer function processing */
56
57#define FC_SRB_READ		(1 << 1)
58#define FC_SRB_WRITE		(1 << 0)
59
60/* constant added to e_d_tov timeout to get rec_tov value */
61#define REC_TOV_CONST		1
62
63/*
64 * The SCp.ptr should be tested and set under the scsi_pkt_queue lock
65 */
66#define CMD_SP(Cmnd)		    ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)
67#define CMD_ENTRY_STATUS(Cmnd)	    ((Cmnd)->SCp.have_data_in)
68#define CMD_COMPL_STATUS(Cmnd)	    ((Cmnd)->SCp.this_residual)
69#define CMD_SCSI_STATUS(Cmnd)	    ((Cmnd)->SCp.Status)
70#define CMD_RESID_LEN(Cmnd)	    ((Cmnd)->SCp.buffers_residual)
71
72/**
73 * struct fc_fcp_internal - FCP layer internal data
74 * @scsi_pkt_pool: Memory pool to draw FCP packets from
75 * @scsi_queue_lock: Protects the scsi_pkt_queue
76 * @scsi_pkt_queue: Current FCP packets
77 * @last_can_queue_ramp_down_time: ramp down time
78 * @last_can_queue_ramp_up_time: ramp up time
79 * @max_can_queue: max can_queue size
80 */
81struct fc_fcp_internal {
82	mempool_t		*scsi_pkt_pool;
83	spinlock_t		scsi_queue_lock;
84	struct list_head	scsi_pkt_queue;
85	unsigned long		last_can_queue_ramp_down_time;
86	unsigned long		last_can_queue_ramp_up_time;
87	int			max_can_queue;
88};
89
90#define fc_get_scsi_internal(x)	((struct fc_fcp_internal *)(x)->scsi_priv)
91
92/*
93 * function prototypes
94 * FC scsi I/O related functions
95 */
96static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
97static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
98static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
99static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
100static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
101static void fc_fcp_error(struct fc_fcp_pkt *, struct fc_frame *);
102static void fc_fcp_recovery(struct fc_fcp_pkt *, u8 code);
103static void fc_fcp_timeout(unsigned long);
104static void fc_fcp_rec(struct fc_fcp_pkt *);
105static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
106static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
107static void fc_io_compl(struct fc_fcp_pkt *);
108
109static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
110static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
111static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
112
113/*
114 * command status codes
115 */
116#define FC_COMPLETE		0
117#define FC_CMD_ABORTED		1
118#define FC_CMD_RESET		2
119#define FC_CMD_PLOGO		3
120#define FC_SNS_RCV		4
121#define FC_TRANS_ERR		5
122#define FC_DATA_OVRRUN		6
123#define FC_DATA_UNDRUN		7
124#define FC_ERROR		8
125#define FC_HRD_ERROR		9
126#define FC_CRC_ERROR		10
127#define FC_TIMED_OUT		11
128
129/*
130 * Error recovery timeout values.
131 */
132#define FC_SCSI_TM_TOV		(10 * HZ)
133#define FC_HOST_RESET_TIMEOUT	(30 * HZ)
134#define FC_CAN_QUEUE_PERIOD	(60 * HZ)
135
136#define FC_MAX_ERROR_CNT	5
137#define FC_MAX_RECOV_RETRY	3
138
139#define FC_FCP_DFLT_QUEUE_DEPTH 32
140
141/**
142 * fc_fcp_pkt_alloc() - Allocate a fcp_pkt
143 * @lport: The local port that the FCP packet is for
144 * @gfp:   GFP flags for allocation
145 *
146 * Return value: fcp_pkt structure or null on allocation failure.
147 * Context:	 Can be called from process context, no lock is required.
148 */
149static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lport, gfp_t gfp)
150{
151	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
152	struct fc_fcp_pkt *fsp;
153
154	fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
155	if (fsp) {
156		memset(fsp, 0, sizeof(*fsp));
157		fsp->lp = lport;
158		atomic_set(&fsp->ref_cnt, 1);
159		init_timer(&fsp->timer);
160		INIT_LIST_HEAD(&fsp->list);
161		spin_lock_init(&fsp->scsi_pkt_lock);
162	}
163	return fsp;
164}
165
166/**
167 * fc_fcp_pkt_release() - Release hold on a fcp_pkt
168 * @fsp: The FCP packet to be released
169 *
170 * Context: Can be called from process or interrupt context,
171 *	    no lock is required.
172 */
173static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
174{
175	if (atomic_dec_and_test(&fsp->ref_cnt)) {
176		struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
177
178		mempool_free(fsp, si->scsi_pkt_pool);
179	}
180}
181
182/**
183 * fc_fcp_pkt_hold() - Hold a fcp_pkt
184 * @fsp: The FCP packet to be held
185 */
186static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
187{
188	atomic_inc(&fsp->ref_cnt);
189}
190
191/**
192 * fc_fcp_pkt_destory() - Release hold on a fcp_pkt
193 * @seq: The sequence that the FCP packet is on (required by destructor API)
194 * @fsp: The FCP packet to be released
195 *
196 * This routine is called by a destructor callback in the exch_seq_send()
197 * routine of the libfc Transport Template. The 'struct fc_seq' is a required
198 * argument even though it is not used by this routine.
199 *
200 * Context: No locking required.
201 */
202static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
203{
204	fc_fcp_pkt_release(fsp);
205}
206
207/**
208 * fc_fcp_lock_pkt() - Lock a fcp_pkt and increase its reference count
209 * @fsp: The FCP packet to be locked and incremented
210 *
211 * We should only return error if we return a command to SCSI-ml before
212 * getting a response. This can happen in cases where we send a abort, but
213 * do not wait for the response and the abort and command can be passing
214 * each other on the wire/network-layer.
215 *
216 * Note: this function locks the packet and gets a reference to allow
217 * callers to call the completion function while the lock is held and
218 * not have to worry about the packets refcount.
219 *
220 * TODO: Maybe we should just have callers grab/release the lock and
221 * have a function that they call to verify the fsp and grab a ref if
222 * needed.
223 */
224static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
225{
226	spin_lock_bh(&fsp->scsi_pkt_lock);
227	if (fsp->state & FC_SRB_COMPL) {
228		spin_unlock_bh(&fsp->scsi_pkt_lock);
229		return -EPERM;
230	}
231
232	fc_fcp_pkt_hold(fsp);
233	return 0;
234}
235
236/**
237 * fc_fcp_unlock_pkt() - Release a fcp_pkt's lock and decrement its
238 *			 reference count
239 * @fsp: The FCP packet to be unlocked and decremented
240 */
241static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
242{
243	spin_unlock_bh(&fsp->scsi_pkt_lock);
244	fc_fcp_pkt_release(fsp);
245}
246
247/**
248 * fc_fcp_timer_set() - Start a timer for a fcp_pkt
249 * @fsp:   The FCP packet to start a timer for
250 * @delay: The timeout period for the timer
251 */
252static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
253{
254	if (!(fsp->state & FC_SRB_COMPL))
255		mod_timer(&fsp->timer, jiffies + delay);
256}
257
258/**
259 * fc_fcp_send_abort() - Send an abort for exchanges associated with a
260 *			 fcp_pkt
261 * @fsp: The FCP packet to abort exchanges on
262 */
263static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
264{
265	if (!fsp->seq_ptr)
266		return -EINVAL;
267
268	fsp->state |= FC_SRB_ABORT_PENDING;
269	return fsp->lp->tt.seq_exch_abort(fsp->seq_ptr, 0);
270}
271
272/**
273 * fc_fcp_retry_cmd() - Retry a fcp_pkt
274 * @fsp: The FCP packet to be retried
275 *
276 * Sets the status code to be FC_ERROR and then calls
277 * fc_fcp_complete_locked() which in turn calls fc_io_compl().
278 * fc_io_compl() will notify the SCSI-ml that the I/O is done.
279 * The SCSI-ml will retry the command.
280 */
281static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp)
282{
283	if (fsp->seq_ptr) {
284		fsp->lp->tt.exch_done(fsp->seq_ptr);
285		fsp->seq_ptr = NULL;
286	}
287
288	fsp->state &= ~FC_SRB_ABORT_PENDING;
289	fsp->io_status = 0;
290	fsp->status_code = FC_ERROR;
291	fc_fcp_complete_locked(fsp);
292}
293
294/**
295 * fc_fcp_ddp_setup() - Calls a LLD's ddp_setup routine to set up DDP context
296 * @fsp: The FCP packet that will manage the DDP frames
297 * @xid: The XID that will be used for the DDP exchange
298 */
299void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
300{
301	struct fc_lport *lport;
302
303	lport = fsp->lp;
304	if ((fsp->req_flags & FC_SRB_READ) &&
305	    (lport->lro_enabled) && (lport->tt.ddp_setup)) {
306		if (lport->tt.ddp_setup(lport, xid, scsi_sglist(fsp->cmd),
307					scsi_sg_count(fsp->cmd)))
308			fsp->xfer_ddp = xid;
309	}
310}
311
312/**
313 * fc_fcp_ddp_done() - Calls a LLD's ddp_done routine to release any
314 *		       DDP related resources for a fcp_pkt
315 * @fsp: The FCP packet that DDP had been used on
316 */
317static void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
318{
319	struct fc_lport *lport;
320
321	if (!fsp)
322		return;
323
324	if (fsp->xfer_ddp == FC_XID_UNKNOWN)
325		return;
326
327	lport = fsp->lp;
328	if (lport->tt.ddp_done) {
329		fsp->xfer_len = lport->tt.ddp_done(lport, fsp->xfer_ddp);
330		fsp->xfer_ddp = FC_XID_UNKNOWN;
331	}
332}
333
334/**
335 * fc_fcp_can_queue_ramp_up() - increases can_queue
336 * @lport: lport to ramp up can_queue
337 *
338 * Locking notes: Called with Scsi_Host lock held
339 */
340static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
341{
342	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
343	int can_queue;
344
345	if (si->last_can_queue_ramp_up_time &&
346	    (time_before(jiffies, si->last_can_queue_ramp_up_time +
347			 FC_CAN_QUEUE_PERIOD)))
348		return;
349
350	if (time_before(jiffies, si->last_can_queue_ramp_down_time +
351			FC_CAN_QUEUE_PERIOD))
352		return;
353
354	si->last_can_queue_ramp_up_time = jiffies;
355
356	can_queue = lport->host->can_queue << 1;
357	if (can_queue >= si->max_can_queue) {
358		can_queue = si->max_can_queue;
359		si->last_can_queue_ramp_down_time = 0;
360	}
361	lport->host->can_queue = can_queue;
362	shost_printk(KERN_ERR, lport->host, "libfc: increased "
363		     "can_queue to %d.\n", can_queue);
364}
365
366/**
367 * fc_fcp_can_queue_ramp_down() - reduces can_queue
368 * @lport: lport to reduce can_queue
369 *
370 * If we are getting memory allocation failures, then we may
371 * be trying to execute too many commands. We let the running
372 * commands complete or timeout, then try again with a reduced
373 * can_queue. Eventually we will hit the point where we run
374 * on all reserved structs.
375 *
376 * Locking notes: Called with Scsi_Host lock held
377 */
378static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport)
379{
380	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
381	int can_queue;
382
383	if (si->last_can_queue_ramp_down_time &&
384	    (time_before(jiffies, si->last_can_queue_ramp_down_time +
385			 FC_CAN_QUEUE_PERIOD)))
386		return;
387
388	si->last_can_queue_ramp_down_time = jiffies;
389
390	can_queue = lport->host->can_queue;
391	can_queue >>= 1;
392	if (!can_queue)
393		can_queue = 1;
394	lport->host->can_queue = can_queue;
395	shost_printk(KERN_ERR, lport->host, "libfc: Could not allocate frame.\n"
396		     "Reducing can_queue to %d.\n", can_queue);
397}
398
399/*
400 * fc_fcp_frame_alloc() -  Allocates fc_frame structure and buffer.
401 * @lport:	fc lport struct
402 * @len:	payload length
403 *
404 * Allocates fc_frame structure and buffer but if fails to allocate
405 * then reduce can_queue.
406 */
407static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport,
408						  size_t len)
409{
410	struct fc_frame *fp;
411	unsigned long flags;
412
413	fp = fc_frame_alloc(lport, len);
414	if (likely(fp))
415		return fp;
416
417	/* error case */
418	spin_lock_irqsave(lport->host->host_lock, flags);
419	fc_fcp_can_queue_ramp_down(lport);
420	spin_unlock_irqrestore(lport->host->host_lock, flags);
421	return NULL;
422}
423
424/**
425 * fc_fcp_recv_data() - Handler for receiving SCSI-FCP data from a target
426 * @fsp: The FCP packet the data is on
427 * @fp:	 The data frame
428 */
429static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
430{
431	struct scsi_cmnd *sc = fsp->cmd;
432	struct fc_lport *lport = fsp->lp;
433	struct fcoe_dev_stats *stats;
434	struct fc_frame_header *fh;
435	size_t start_offset;
436	size_t offset;
437	u32 crc;
438	u32 copy_len = 0;
439	size_t len;
440	void *buf;
441	struct scatterlist *sg;
442	u32 nents;
443	u8 host_bcode = FC_COMPLETE;
444
445	fh = fc_frame_header_get(fp);
446	offset = ntohl(fh->fh_parm_offset);
447	start_offset = offset;
448	len = fr_len(fp) - sizeof(*fh);
449	buf = fc_frame_payload_get(fp, 0);
450
451	/*
452	 * if this I/O is ddped then clear it and initiate recovery since data
453	 * frames are expected to be placed directly in that case.
454	 *
455	 * Indicate error to scsi-ml because something went wrong with the
456	 * ddp handling to get us here.
457	 */
458	if (fsp->xfer_ddp != FC_XID_UNKNOWN) {
459		fc_fcp_ddp_done(fsp);
460		FC_FCP_DBG(fsp, "DDP I/O in fc_fcp_recv_data set ERROR\n");
461		host_bcode = FC_ERROR;
462		goto err;
463	}
464	if (offset + len > fsp->data_len) {
465		/* this should never happen */
466		if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
467		    fc_frame_crc_check(fp))
468			goto crc_err;
469		FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
470			   "data_len %x\n", len, offset, fsp->data_len);
471
472		/* Data is corrupted indicate scsi-ml should retry */
473		host_bcode = FC_DATA_OVRRUN;
474		goto err;
475	}
476	if (offset != fsp->xfer_len)
477		fsp->state |= FC_SRB_DISCONTIG;
478
479	sg = scsi_sglist(sc);
480	nents = scsi_sg_count(sc);
481
482	if (!(fr_flags(fp) & FCPHF_CRC_UNCHECKED)) {
483		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
484						    &offset, KM_SOFTIRQ0, NULL);
485	} else {
486		crc = crc32(~0, (u8 *) fh, sizeof(*fh));
487		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
488						    &offset, KM_SOFTIRQ0, &crc);
489		buf = fc_frame_payload_get(fp, 0);
490		if (len % 4)
491			crc = crc32(crc, buf + len, 4 - (len % 4));
492
493		if (~crc != le32_to_cpu(fr_crc(fp))) {
494crc_err:
495			stats = per_cpu_ptr(lport->dev_stats, get_cpu());
496			stats->ErrorFrames++;
497			/* per cpu count, not total count, but OK for limit */
498			if (stats->InvalidCRCCount++ < 5)
499				printk(KERN_WARNING "libfc: CRC error on data "
500				       "frame for port (%6.6x)\n",
501				       lport->port_id);
502			put_cpu();
503			/*
504			 * Assume the frame is total garbage.
505			 * We may have copied it over the good part
506			 * of the buffer.
507			 * If so, we need to retry the entire operation.
508			 * Otherwise, ignore it.
509			 */
510			if (fsp->state & FC_SRB_DISCONTIG) {
511				host_bcode = FC_CRC_ERROR;
512				goto err;
513			}
514			return;
515		}
516	}
517
518	if (fsp->xfer_contig_end == start_offset)
519		fsp->xfer_contig_end += copy_len;
520	fsp->xfer_len += copy_len;
521
522	/*
523	 * In the very rare event that this data arrived after the response
524	 * and completes the transfer, call the completion handler.
525	 */
526	if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
527	    fsp->xfer_len == fsp->data_len - fsp->scsi_resid)
528		fc_fcp_complete_locked(fsp);
529	return;
530err:
531	fc_fcp_recovery(fsp, host_bcode);
532}
533
534/**
535 * fc_fcp_send_data() - Send SCSI data to a target
536 * @fsp:      The FCP packet the data is on
537 * @sp:	      The sequence the data is to be sent on
538 * @offset:   The starting offset for this data request
539 * @seq_blen: The burst length for this data request
540 *
541 * Called after receiving a Transfer Ready data descriptor.
542 * If the LLD is capable of sequence offload then send down the
543 * seq_blen amount of data in single frame, otherwise send
544 * multiple frames of the maximum frame payload supported by
545 * the target port.
546 */
547static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
548			    size_t offset, size_t seq_blen)
549{
550	struct fc_exch *ep;
551	struct scsi_cmnd *sc;
552	struct scatterlist *sg;
553	struct fc_frame *fp = NULL;
554	struct fc_lport *lport = fsp->lp;
555	struct page *page;
556	size_t remaining;
557	size_t t_blen;
558	size_t tlen;
559	size_t sg_bytes;
560	size_t frame_offset, fh_parm_offset;
561	size_t off;
562	int error;
563	void *data = NULL;
564	void *page_addr;
565	int using_sg = lport->sg_supp;
566	u32 f_ctl;
567
568	WARN_ON(seq_blen <= 0);
569	if (unlikely(offset + seq_blen > fsp->data_len)) {
570		/* this should never happen */
571		FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
572			   "offset %zx\n", seq_blen, offset);
573		fc_fcp_send_abort(fsp);
574		return 0;
575	} else if (offset != fsp->xfer_len) {
576		/* Out of Order Data Request - no problem, but unexpected. */
577		FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
578			   "seq_blen %zx offset %zx\n", seq_blen, offset);
579	}
580
581	/*
582	 * if LLD is capable of seq_offload then set transport
583	 * burst length (t_blen) to seq_blen, otherwise set t_blen
584	 * to max FC frame payload previously set in fsp->max_payload.
585	 */
586	t_blen = fsp->max_payload;
587	if (lport->seq_offload) {
588		t_blen = min(seq_blen, (size_t)lport->lso_max);
589		FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
590			   fsp, seq_blen, lport->lso_max, t_blen);
591	}
592
593	if (t_blen > 512)
594		t_blen &= ~(512 - 1);	/* round down to block size */
595	sc = fsp->cmd;
596
597	remaining = seq_blen;
598	fh_parm_offset = frame_offset = offset;
599	tlen = 0;
600	seq = lport->tt.seq_start_next(seq);
601	f_ctl = FC_FC_REL_OFF;
602	WARN_ON(!seq);
603
604	sg = scsi_sglist(sc);
605
606	while (remaining > 0 && sg) {
607		if (offset >= sg->length) {
608			offset -= sg->length;
609			sg = sg_next(sg);
610			continue;
611		}
612		if (!fp) {
613			tlen = min(t_blen, remaining);
614
615			/*
616			 * TODO.  Temporary workaround.	 fc_seq_send() can't
617			 * handle odd lengths in non-linear skbs.
618			 * This will be the final fragment only.
619			 */
620			if (tlen % 4)
621				using_sg = 0;
622			fp = fc_frame_alloc(lport, using_sg ? 0 : tlen);
623			if (!fp)
624				return -ENOMEM;
625
626			data = fc_frame_header_get(fp) + 1;
627			fh_parm_offset = frame_offset;
628			fr_max_payload(fp) = fsp->max_payload;
629		}
630
631		off = offset + sg->offset;
632		sg_bytes = min(tlen, sg->length - offset);
633		sg_bytes = min(sg_bytes,
634			       (size_t) (PAGE_SIZE - (off & ~PAGE_MASK)));
635		page = sg_page(sg) + (off >> PAGE_SHIFT);
636		if (using_sg) {
637			get_page(page);
638			skb_fill_page_desc(fp_skb(fp),
639					   skb_shinfo(fp_skb(fp))->nr_frags,
640					   page, off & ~PAGE_MASK, sg_bytes);
641			fp_skb(fp)->data_len += sg_bytes;
642			fr_len(fp) += sg_bytes;
643			fp_skb(fp)->truesize += PAGE_SIZE;
644		} else {
645			/*
646			 * The scatterlist item may be bigger than PAGE_SIZE,
647			 * but we must not cross pages inside the kmap.
648			 */
649			page_addr = kmap_atomic(page, KM_SOFTIRQ0);
650			memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
651			       sg_bytes);
652			kunmap_atomic(page_addr, KM_SOFTIRQ0);
653			data += sg_bytes;
654		}
655		offset += sg_bytes;
656		frame_offset += sg_bytes;
657		tlen -= sg_bytes;
658		remaining -= sg_bytes;
659
660		if ((skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN) &&
661		    (tlen))
662			continue;
663
664		/*
665		 * Send sequence with transfer sequence initiative in case
666		 * this is last FCP frame of the sequence.
667		 */
668		if (remaining == 0)
669			f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
670
671		ep = fc_seq_exch(seq);
672		fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
673			       FC_TYPE_FCP, f_ctl, fh_parm_offset);
674
675		/*
676		 * send fragment using for a sequence.
677		 */
678		error = lport->tt.seq_send(lport, seq, fp);
679		if (error) {
680			WARN_ON(1);		/* send error should be rare */
681			fc_fcp_retry_cmd(fsp);
682			return 0;
683		}
684		fp = NULL;
685	}
686	fsp->xfer_len += seq_blen;	/* premature count? */
687	return 0;
688}
689
690/**
691 * fc_fcp_abts_resp() - Send an ABTS response
692 * @fsp: The FCP packet that is being aborted
693 * @fp:	 The response frame
694 */
695static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
696{
697	int ba_done = 1;
698	struct fc_ba_rjt *brp;
699	struct fc_frame_header *fh;
700
701	fh = fc_frame_header_get(fp);
702	switch (fh->fh_r_ctl) {
703	case FC_RCTL_BA_ACC:
704		break;
705	case FC_RCTL_BA_RJT:
706		brp = fc_frame_payload_get(fp, sizeof(*brp));
707		if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
708			break;
709		/* fall thru */
710	default:
711		/*
712		 * we will let the command timeout
713		 * and scsi-ml recover in this case,
714		 * therefore cleared the ba_done flag.
715		 */
716		ba_done = 0;
717	}
718
719	if (ba_done) {
720		fsp->state |= FC_SRB_ABORTED;
721		fsp->state &= ~FC_SRB_ABORT_PENDING;
722
723		if (fsp->wait_for_comp)
724			complete(&fsp->tm_done);
725		else
726			fc_fcp_complete_locked(fsp);
727	}
728}
729
730/**
731 * fc_fcp_recv() - Reveive an FCP frame
732 * @seq: The sequence the frame is on
733 * @fp:	 The received frame
734 * @arg: The related FCP packet
735 *
736 * Context: Called from Soft IRQ context. Can not be called
737 *	    holding the FCP packet list lock.
738 */
739static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
740{
741	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
742	struct fc_lport *lport = fsp->lp;
743	struct fc_frame_header *fh;
744	struct fcp_txrdy *dd;
745	u8 r_ctl;
746	int rc = 0;
747
748	if (IS_ERR(fp)) {
749		fc_fcp_error(fsp, fp);
750		return;
751	}
752
753	fh = fc_frame_header_get(fp);
754	r_ctl = fh->fh_r_ctl;
755
756	if (lport->state != LPORT_ST_READY)
757		goto out;
758	if (fc_fcp_lock_pkt(fsp))
759		goto out;
760	fsp->last_pkt_time = jiffies;
761
762	if (fh->fh_type == FC_TYPE_BLS) {
763		fc_fcp_abts_resp(fsp, fp);
764		goto unlock;
765	}
766
767	if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING))
768		goto unlock;
769
770	if (r_ctl == FC_RCTL_DD_DATA_DESC) {
771		/*
772		 * received XFER RDY from the target
773		 * need to send data to the target
774		 */
775		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
776		dd = fc_frame_payload_get(fp, sizeof(*dd));
777		WARN_ON(!dd);
778
779		rc = fc_fcp_send_data(fsp, seq,
780				      (size_t) ntohl(dd->ft_data_ro),
781				      (size_t) ntohl(dd->ft_burst_len));
782		if (!rc)
783			seq->rec_data = fsp->xfer_len;
784	} else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
785		/*
786		 * received a DATA frame
787		 * next we will copy the data to the system buffer
788		 */
789		WARN_ON(fr_len(fp) < sizeof(*fh));	/* len may be 0 */
790		fc_fcp_recv_data(fsp, fp);
791		seq->rec_data = fsp->xfer_contig_end;
792	} else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
793		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
794
795		fc_fcp_resp(fsp, fp);
796	} else {
797		FC_FCP_DBG(fsp, "unexpected frame.  r_ctl %x\n", r_ctl);
798	}
799unlock:
800	fc_fcp_unlock_pkt(fsp);
801out:
802	fc_frame_free(fp);
803}
804
805/**
806 * fc_fcp_resp() - Handler for FCP responses
807 * @fsp: The FCP packet the response is for
808 * @fp:	 The response frame
809 */
810static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
811{
812	struct fc_frame_header *fh;
813	struct fcp_resp *fc_rp;
814	struct fcp_resp_ext *rp_ex;
815	struct fcp_resp_rsp_info *fc_rp_info;
816	u32 plen;
817	u32 expected_len;
818	u32 respl = 0;
819	u32 snsl = 0;
820	u8 flags = 0;
821
822	plen = fr_len(fp);
823	fh = (struct fc_frame_header *)fr_hdr(fp);
824	if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
825		goto len_err;
826	plen -= sizeof(*fh);
827	fc_rp = (struct fcp_resp *)(fh + 1);
828	fsp->cdb_status = fc_rp->fr_status;
829	flags = fc_rp->fr_flags;
830	fsp->scsi_comp_flags = flags;
831	expected_len = fsp->data_len;
832
833	/* if ddp, update xfer len */
834	fc_fcp_ddp_done(fsp);
835
836	if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
837		rp_ex = (void *)(fc_rp + 1);
838		if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
839			if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
840				goto len_err;
841			fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
842			if (flags & FCP_RSP_LEN_VAL) {
843				respl = ntohl(rp_ex->fr_rsp_len);
844				if (respl != sizeof(*fc_rp_info))
845					goto len_err;
846				if (fsp->wait_for_comp) {
847					/* Abuse cdb_status for rsp code */
848					fsp->cdb_status = fc_rp_info->rsp_code;
849					complete(&fsp->tm_done);
850					/*
851					 * tmfs will not have any scsi cmd so
852					 * exit here
853					 */
854					return;
855				}
856			}
857			if (flags & FCP_SNS_LEN_VAL) {
858				snsl = ntohl(rp_ex->fr_sns_len);
859				if (snsl > SCSI_SENSE_BUFFERSIZE)
860					snsl = SCSI_SENSE_BUFFERSIZE;
861				memcpy(fsp->cmd->sense_buffer,
862				       (char *)fc_rp_info + respl, snsl);
863			}
864		}
865		if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
866			if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
867				goto len_err;
868			if (flags & FCP_RESID_UNDER) {
869				fsp->scsi_resid = ntohl(rp_ex->fr_resid);
870				/*
871				 * The cmnd->underflow is the minimum number of
872				 * bytes that must be transfered for this
873				 * command.  Provided a sense condition is not
874				 * present, make sure the actual amount
875				 * transferred is at least the underflow value
876				 * or fail.
877				 */
878				if (!(flags & FCP_SNS_LEN_VAL) &&
879				    (fc_rp->fr_status == 0) &&
880				    (scsi_bufflen(fsp->cmd) -
881				     fsp->scsi_resid) < fsp->cmd->underflow)
882					goto err;
883				expected_len -= fsp->scsi_resid;
884			} else {
885				fsp->status_code = FC_ERROR;
886			}
887		}
888	}
889	fsp->state |= FC_SRB_RCV_STATUS;
890
891	/*
892	 * Check for missing or extra data frames.
893	 */
894	if (unlikely(fsp->xfer_len != expected_len)) {
895		if (fsp->xfer_len < expected_len) {
896			/*
897			 * Some data may be queued locally,
898			 * Wait a at least one jiffy to see if it is delivered.
899			 * If this expires without data, we may do SRR.
900			 */
901			fc_fcp_timer_set(fsp, 2);
902			return;
903		}
904		fsp->status_code = FC_DATA_OVRRUN;
905		FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx greater than expected, "
906			   "len %x, data len %x\n",
907			   fsp->rport->port_id,
908			   fsp->xfer_len, expected_len, fsp->data_len);
909	}
910	fc_fcp_complete_locked(fsp);
911	return;
912
913len_err:
914	FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
915		   "snsl %u\n", flags, fr_len(fp), respl, snsl);
916err:
917	fsp->status_code = FC_ERROR;
918	fc_fcp_complete_locked(fsp);
919}
920
921/**
922 * fc_fcp_complete_locked() - Complete processing of a fcp_pkt with the
923 *			      fcp_pkt lock held
924 * @fsp: The FCP packet to be completed
925 *
926 * This function may sleep if a timer is pending. The packet lock must be
927 * held, and the host lock must not be held.
928 */
929static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
930{
931	struct fc_lport *lport = fsp->lp;
932	struct fc_seq *seq;
933	struct fc_exch *ep;
934	u32 f_ctl;
935
936	if (fsp->state & FC_SRB_ABORT_PENDING)
937		return;
938
939	if (fsp->state & FC_SRB_ABORTED) {
940		if (!fsp->status_code)
941			fsp->status_code = FC_CMD_ABORTED;
942	} else {
943		/*
944		 * Test for transport underrun, independent of response
945		 * underrun status.
946		 */
947		if (fsp->xfer_len < fsp->data_len && !fsp->io_status &&
948		    (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
949		     fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
950			fsp->status_code = FC_DATA_UNDRUN;
951			fsp->io_status = 0;
952		}
953	}
954
955	seq = fsp->seq_ptr;
956	if (seq) {
957		fsp->seq_ptr = NULL;
958		if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
959			struct fc_frame *conf_frame;
960			struct fc_seq *csp;
961
962			csp = lport->tt.seq_start_next(seq);
963			conf_frame = fc_fcp_frame_alloc(fsp->lp, 0);
964			if (conf_frame) {
965				f_ctl = FC_FC_SEQ_INIT;
966				f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
967				ep = fc_seq_exch(seq);
968				fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
969					       ep->did, ep->sid,
970					       FC_TYPE_FCP, f_ctl, 0);
971				lport->tt.seq_send(lport, csp, conf_frame);
972			}
973		}
974		lport->tt.exch_done(seq);
975	}
976	fc_io_compl(fsp);
977}
978
979/**
980 * fc_fcp_cleanup_cmd() - Cancel the active exchange on a fcp_pkt
981 * @fsp:   The FCP packet whose exchanges should be canceled
982 * @error: The reason for the cancellation
983 */
984static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
985{
986	struct fc_lport *lport = fsp->lp;
987
988	if (fsp->seq_ptr) {
989		lport->tt.exch_done(fsp->seq_ptr);
990		fsp->seq_ptr = NULL;
991	}
992	fsp->status_code = error;
993}
994
995/**
996 * fc_fcp_cleanup_each_cmd() - Cancel all exchanges on a local port
997 * @lport: The local port whose exchanges should be canceled
998 * @id:	   The target's ID
999 * @lun:   The LUN
1000 * @error: The reason for cancellation
1001 *
1002 * If lun or id is -1, they are ignored.
1003 */
1004static void fc_fcp_cleanup_each_cmd(struct fc_lport *lport, unsigned int id,
1005				    unsigned int lun, int error)
1006{
1007	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1008	struct fc_fcp_pkt *fsp;
1009	struct scsi_cmnd *sc_cmd;
1010	unsigned long flags;
1011
1012	spin_lock_irqsave(&si->scsi_queue_lock, flags);
1013restart:
1014	list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
1015		sc_cmd = fsp->cmd;
1016		if (id != -1 && scmd_id(sc_cmd) != id)
1017			continue;
1018
1019		if (lun != -1 && sc_cmd->device->lun != lun)
1020			continue;
1021
1022		fc_fcp_pkt_hold(fsp);
1023		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1024
1025		if (!fc_fcp_lock_pkt(fsp)) {
1026			fc_fcp_cleanup_cmd(fsp, error);
1027			fc_io_compl(fsp);
1028			fc_fcp_unlock_pkt(fsp);
1029		}
1030
1031		fc_fcp_pkt_release(fsp);
1032		spin_lock_irqsave(&si->scsi_queue_lock, flags);
1033		/*
1034		 * while we dropped the lock multiple pkts could
1035		 * have been released, so we have to start over.
1036		 */
1037		goto restart;
1038	}
1039	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1040}
1041
1042/**
1043 * fc_fcp_abort_io() - Abort all FCP-SCSI exchanges on a local port
1044 * @lport: The local port whose exchanges are to be aborted
1045 */
1046static void fc_fcp_abort_io(struct fc_lport *lport)
1047{
1048	fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_HRD_ERROR);
1049}
1050
1051/**
1052 * fc_fcp_pkt_send() - Send a fcp_pkt
1053 * @lport: The local port to send the FCP packet on
1054 * @fsp:   The FCP packet to send
1055 *
1056 * Return:  Zero for success and -1 for failure
1057 * Locks:   Called without locks held
1058 */
1059static int fc_fcp_pkt_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp)
1060{
1061	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1062	unsigned long flags;
1063	int rc;
1064
1065	fsp->cmd->SCp.ptr = (char *)fsp;
1066	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1067	fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
1068
1069	int_to_scsilun(fsp->cmd->device->lun,
1070		       (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
1071	memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
1072
1073	spin_lock_irqsave(&si->scsi_queue_lock, flags);
1074	list_add_tail(&fsp->list, &si->scsi_pkt_queue);
1075	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1076	rc = lport->tt.fcp_cmd_send(lport, fsp, fc_fcp_recv);
1077	if (unlikely(rc)) {
1078		spin_lock_irqsave(&si->scsi_queue_lock, flags);
1079		list_del(&fsp->list);
1080		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1081	}
1082
1083	return rc;
1084}
1085
1086/**
1087 * get_fsp_rec_tov() - Helper function to get REC_TOV
1088 * @fsp: the FCP packet
1089 */
1090static inline unsigned int get_fsp_rec_tov(struct fc_fcp_pkt *fsp)
1091{
1092	struct fc_rport *rport;
1093	struct fc_rport_libfc_priv *rpriv;
1094
1095	rport = fsp->rport;
1096	rpriv = rport->dd_data;
1097
1098	return rpriv->e_d_tov + REC_TOV_CONST;
1099}
1100
1101/**
1102 * fc_fcp_cmd_send() - Send a FCP command
1103 * @lport: The local port to send the command on
1104 * @fsp:   The FCP packet the command is on
1105 * @resp:  The handler for the response
1106 */
1107static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1108			   void (*resp)(struct fc_seq *,
1109					struct fc_frame *fp,
1110					void *arg))
1111{
1112	struct fc_frame *fp;
1113	struct fc_seq *seq;
1114	struct fc_rport *rport;
1115	struct fc_rport_libfc_priv *rpriv;
1116	const size_t len = sizeof(fsp->cdb_cmd);
1117	int rc = 0;
1118	unsigned int rec_tov;
1119
1120	if (fc_fcp_lock_pkt(fsp))
1121		return 0;
1122
1123	fp = fc_fcp_frame_alloc(lport, sizeof(fsp->cdb_cmd));
1124	if (!fp) {
1125		rc = -1;
1126		goto unlock;
1127	}
1128
1129	memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
1130	fr_fsp(fp) = fsp;
1131	rport = fsp->rport;
1132	fsp->max_payload = rport->maxframe_size;
1133	rpriv = rport->dd_data;
1134
1135	fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
1136		       rpriv->local_port->port_id, FC_TYPE_FCP,
1137		       FC_FCTL_REQ, 0);
1138
1139	seq = lport->tt.exch_seq_send(lport, fp, resp, fc_fcp_pkt_destroy,
1140				      fsp, 0);
1141	if (!seq) {
1142		rc = -1;
1143		goto unlock;
1144	}
1145	fsp->last_pkt_time = jiffies;
1146	fsp->seq_ptr = seq;
1147	fc_fcp_pkt_hold(fsp);	/* hold for fc_fcp_pkt_destroy */
1148
1149	rec_tov = get_fsp_rec_tov(fsp);
1150
1151	setup_timer(&fsp->timer, fc_fcp_timeout, (unsigned long)fsp);
1152
1153	if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1154		fc_fcp_timer_set(fsp, rec_tov);
1155
1156unlock:
1157	fc_fcp_unlock_pkt(fsp);
1158	return rc;
1159}
1160
1161/**
1162 * fc_fcp_error() - Handler for FCP layer errors
1163 * @fsp: The FCP packet the error is on
1164 * @fp:	 The frame that has errored
1165 */
1166static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1167{
1168	int error = PTR_ERR(fp);
1169
1170	if (fc_fcp_lock_pkt(fsp))
1171		return;
1172
1173	if (error == -FC_EX_CLOSED) {
1174		fc_fcp_retry_cmd(fsp);
1175		goto unlock;
1176	}
1177
1178	/*
1179	 * clear abort pending, because the lower layer
1180	 * decided to force completion.
1181	 */
1182	fsp->state &= ~FC_SRB_ABORT_PENDING;
1183	fsp->status_code = FC_CMD_PLOGO;
1184	fc_fcp_complete_locked(fsp);
1185unlock:
1186	fc_fcp_unlock_pkt(fsp);
1187}
1188
1189/**
1190 * fc_fcp_pkt_abort() - Abort a fcp_pkt
1191 * @fsp:   The FCP packet to abort on
1192 *
1193 * Called to send an abort and then wait for abort completion
1194 */
1195static int fc_fcp_pkt_abort(struct fc_fcp_pkt *fsp)
1196{
1197	int rc = FAILED;
1198
1199	if (fc_fcp_send_abort(fsp))
1200		return FAILED;
1201
1202	init_completion(&fsp->tm_done);
1203	fsp->wait_for_comp = 1;
1204
1205	spin_unlock_bh(&fsp->scsi_pkt_lock);
1206	rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1207	spin_lock_bh(&fsp->scsi_pkt_lock);
1208	fsp->wait_for_comp = 0;
1209
1210	if (!rc) {
1211		FC_FCP_DBG(fsp, "target abort cmd  failed\n");
1212		rc = FAILED;
1213	} else if (fsp->state & FC_SRB_ABORTED) {
1214		FC_FCP_DBG(fsp, "target abort cmd  passed\n");
1215		rc = SUCCESS;
1216		fc_fcp_complete_locked(fsp);
1217	}
1218
1219	return rc;
1220}
1221
1222/**
1223 * fc_lun_reset_send() - Send LUN reset command
1224 * @data: The FCP packet that identifies the LUN to be reset
1225 */
1226static void fc_lun_reset_send(unsigned long data)
1227{
1228	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1229	struct fc_lport *lport = fsp->lp;
1230	unsigned int rec_tov;
1231
1232	if (lport->tt.fcp_cmd_send(lport, fsp, fc_tm_done)) {
1233		if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
1234			return;
1235		if (fc_fcp_lock_pkt(fsp))
1236			return;
1237		rec_tov = get_fsp_rec_tov(fsp);
1238		setup_timer(&fsp->timer, fc_lun_reset_send, (unsigned long)fsp);
1239		fc_fcp_timer_set(fsp, rec_tov);
1240		fc_fcp_unlock_pkt(fsp);
1241	}
1242}
1243
1244/**
1245 * fc_lun_reset() - Send a LUN RESET command to a device
1246 *		    and wait for the reply
1247 * @lport: The local port to sent the comand on
1248 * @fsp:   The FCP packet that identifies the LUN to be reset
1249 * @id:	   The SCSI command ID
1250 * @lun:   The LUN ID to be reset
1251 */
1252static int fc_lun_reset(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1253			unsigned int id, unsigned int lun)
1254{
1255	int rc;
1256
1257	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1258	fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
1259	int_to_scsilun(lun, (struct scsi_lun *)fsp->cdb_cmd.fc_lun);
1260
1261	fsp->wait_for_comp = 1;
1262	init_completion(&fsp->tm_done);
1263
1264	fc_lun_reset_send((unsigned long)fsp);
1265
1266	/*
1267	 * wait for completion of reset
1268	 * after that make sure all commands are terminated
1269	 */
1270	rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1271
1272	spin_lock_bh(&fsp->scsi_pkt_lock);
1273	fsp->state |= FC_SRB_COMPL;
1274	spin_unlock_bh(&fsp->scsi_pkt_lock);
1275
1276	del_timer_sync(&fsp->timer);
1277
1278	spin_lock_bh(&fsp->scsi_pkt_lock);
1279	if (fsp->seq_ptr) {
1280		lport->tt.exch_done(fsp->seq_ptr);
1281		fsp->seq_ptr = NULL;
1282	}
1283	fsp->wait_for_comp = 0;
1284	spin_unlock_bh(&fsp->scsi_pkt_lock);
1285
1286	if (!rc) {
1287		FC_SCSI_DBG(lport, "lun reset failed\n");
1288		return FAILED;
1289	}
1290
1291	/* cdb_status holds the tmf's rsp code */
1292	if (fsp->cdb_status != FCP_TMF_CMPL)
1293		return FAILED;
1294
1295	FC_SCSI_DBG(lport, "lun reset to lun %u completed\n", lun);
1296	fc_fcp_cleanup_each_cmd(lport, id, lun, FC_CMD_ABORTED);
1297	return SUCCESS;
1298}
1299
1300/**
1301 * fc_tm_done() - Task Managment response handler
1302 * @seq: The sequence that the response is on
1303 * @fp:	 The response frame
1304 * @arg: The FCP packet the response is for
1305 */
1306static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1307{
1308	struct fc_fcp_pkt *fsp = arg;
1309	struct fc_frame_header *fh;
1310
1311	if (IS_ERR(fp)) {
1312		/*
1313		 * If there is an error just let it timeout or wait
1314		 * for TMF to be aborted if it timedout.
1315		 *
1316		 * scsi-eh will escalate for when either happens.
1317		 */
1318		return;
1319	}
1320
1321	if (fc_fcp_lock_pkt(fsp))
1322		return;
1323
1324	/*
1325	 * raced with eh timeout handler.
1326	 */
1327	if (!fsp->seq_ptr || !fsp->wait_for_comp) {
1328		spin_unlock_bh(&fsp->scsi_pkt_lock);
1329		return;
1330	}
1331
1332	fh = fc_frame_header_get(fp);
1333	if (fh->fh_type != FC_TYPE_BLS)
1334		fc_fcp_resp(fsp, fp);
1335	fsp->seq_ptr = NULL;
1336	fsp->lp->tt.exch_done(seq);
1337	fc_frame_free(fp);
1338	fc_fcp_unlock_pkt(fsp);
1339}
1340
1341/**
1342 * fc_fcp_cleanup() - Cleanup all FCP exchanges on a local port
1343 * @lport: The local port to be cleaned up
1344 */
1345static void fc_fcp_cleanup(struct fc_lport *lport)
1346{
1347	fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_ERROR);
1348}
1349
1350/**
1351 * fc_fcp_timeout() - Handler for fcp_pkt timeouts
1352 * @data: The FCP packet that has timed out
1353 *
1354 * If REC is supported then just issue it and return. The REC exchange will
1355 * complete or time out and recovery can continue at that point. Otherwise,
1356 * if the response has been received without all the data it has been
1357 * ER_TIMEOUT since the response was received. If the response has not been
1358 * received we see if data was received recently. If it has been then we
1359 * continue waiting, otherwise, we abort the command.
1360 */
1361static void fc_fcp_timeout(unsigned long data)
1362{
1363	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1364	struct fc_rport *rport = fsp->rport;
1365	struct fc_rport_libfc_priv *rpriv = rport->dd_data;
1366
1367	if (fc_fcp_lock_pkt(fsp))
1368		return;
1369
1370	if (fsp->cdb_cmd.fc_tm_flags)
1371		goto unlock;
1372
1373	fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
1374
1375	if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1376		fc_fcp_rec(fsp);
1377	else if (fsp->state & FC_SRB_RCV_STATUS)
1378		fc_fcp_complete_locked(fsp);
1379	else
1380		fc_fcp_recovery(fsp, FC_TIMED_OUT);
1381	fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
1382unlock:
1383	fc_fcp_unlock_pkt(fsp);
1384}
1385
1386/**
1387 * fc_fcp_rec() - Send a REC ELS request
1388 * @fsp: The FCP packet to send the REC request on
1389 */
1390static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
1391{
1392	struct fc_lport *lport;
1393	struct fc_frame *fp;
1394	struct fc_rport *rport;
1395	struct fc_rport_libfc_priv *rpriv;
1396	unsigned int rec_tov;
1397
1398	lport = fsp->lp;
1399	rport = fsp->rport;
1400	rpriv = rport->dd_data;
1401	if (!fsp->seq_ptr || rpriv->rp_state != RPORT_ST_READY) {
1402		fsp->status_code = FC_HRD_ERROR;
1403		fsp->io_status = 0;
1404		fc_fcp_complete_locked(fsp);
1405		return;
1406	}
1407
1408	rec_tov = get_fsp_rec_tov(fsp);
1409
1410	fp = fc_fcp_frame_alloc(lport, sizeof(struct fc_els_rec));
1411	if (!fp)
1412		goto retry;
1413
1414	fr_seq(fp) = fsp->seq_ptr;
1415	fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
1416		       rpriv->local_port->port_id, FC_TYPE_ELS,
1417		       FC_FCTL_REQ, 0);
1418	if (lport->tt.elsct_send(lport, rport->port_id, fp, ELS_REC,
1419				 fc_fcp_rec_resp, fsp,
1420				 jiffies_to_msecs(rec_tov))) {
1421		fc_fcp_pkt_hold(fsp);		/* hold while REC outstanding */
1422		return;
1423	}
1424retry:
1425	if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1426		fc_fcp_timer_set(fsp, rec_tov);
1427	else
1428		fc_fcp_recovery(fsp, FC_TIMED_OUT);
1429}
1430
1431/**
1432 * fc_fcp_rec_resp() - Handler for REC ELS responses
1433 * @seq: The sequence the response is on
1434 * @fp:	 The response frame
1435 * @arg: The FCP packet the response is on
1436 *
1437 * If the response is a reject then the scsi layer will handle
1438 * the timeout. If the response is a LS_ACC then if the I/O was not completed
1439 * set the timeout and return. If the I/O was completed then complete the
1440 * exchange and tell the SCSI layer.
1441 */
1442static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1443{
1444	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
1445	struct fc_els_rec_acc *recp;
1446	struct fc_els_ls_rjt *rjt;
1447	u32 e_stat;
1448	u8 opcode;
1449	u32 offset;
1450	enum dma_data_direction data_dir;
1451	enum fc_rctl r_ctl;
1452	struct fc_rport_libfc_priv *rpriv;
1453
1454	if (IS_ERR(fp)) {
1455		fc_fcp_rec_error(fsp, fp);
1456		return;
1457	}
1458
1459	if (fc_fcp_lock_pkt(fsp))
1460		goto out;
1461
1462	fsp->recov_retry = 0;
1463	opcode = fc_frame_payload_op(fp);
1464	if (opcode == ELS_LS_RJT) {
1465		rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1466		switch (rjt->er_reason) {
1467		default:
1468			FC_FCP_DBG(fsp, "device %x unexpected REC reject "
1469				   "reason %d expl %d\n",
1470				   fsp->rport->port_id, rjt->er_reason,
1471				   rjt->er_explan);
1472			/* fall through */
1473		case ELS_RJT_UNSUP:
1474			FC_FCP_DBG(fsp, "device does not support REC\n");
1475			rpriv = fsp->rport->dd_data;
1476			/*
1477			 * if we do not spport RECs or got some bogus
1478			 * reason then resetup timer so we check for
1479			 * making progress.
1480			 */
1481			rpriv->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
1482			break;
1483		case ELS_RJT_LOGIC:
1484		case ELS_RJT_UNAB:
1485			/*
1486			 * If no data transfer, the command frame got dropped
1487			 * so we just retry.  If data was transferred, we
1488			 * lost the response but the target has no record,
1489			 * so we abort and retry.
1490			 */
1491			if (rjt->er_explan == ELS_EXPL_OXID_RXID &&
1492			    fsp->xfer_len == 0) {
1493				fc_fcp_retry_cmd(fsp);
1494				break;
1495			}
1496			fc_fcp_recovery(fsp, FC_ERROR);
1497			break;
1498		}
1499	} else if (opcode == ELS_LS_ACC) {
1500		if (fsp->state & FC_SRB_ABORTED)
1501			goto unlock_out;
1502
1503		data_dir = fsp->cmd->sc_data_direction;
1504		recp = fc_frame_payload_get(fp, sizeof(*recp));
1505		offset = ntohl(recp->reca_fc4value);
1506		e_stat = ntohl(recp->reca_e_stat);
1507
1508		if (e_stat & ESB_ST_COMPLETE) {
1509
1510			/*
1511			 * The exchange is complete.
1512			 *
1513			 * For output, we must've lost the response.
1514			 * For input, all data must've been sent.
1515			 * We lost may have lost the response
1516			 * (and a confirmation was requested) and maybe
1517			 * some data.
1518			 *
1519			 * If all data received, send SRR
1520			 * asking for response.	 If partial data received,
1521			 * or gaps, SRR requests data at start of gap.
1522			 * Recovery via SRR relies on in-order-delivery.
1523			 */
1524			if (data_dir == DMA_TO_DEVICE) {
1525				r_ctl = FC_RCTL_DD_CMD_STATUS;
1526			} else if (fsp->xfer_contig_end == offset) {
1527				r_ctl = FC_RCTL_DD_CMD_STATUS;
1528			} else {
1529				offset = fsp->xfer_contig_end;
1530				r_ctl = FC_RCTL_DD_SOL_DATA;
1531			}
1532			fc_fcp_srr(fsp, r_ctl, offset);
1533		} else if (e_stat & ESB_ST_SEQ_INIT) {
1534			unsigned int rec_tov = get_fsp_rec_tov(fsp);
1535			/*
1536			 * The remote port has the initiative, so just
1537			 * keep waiting for it to complete.
1538			 */
1539			fc_fcp_timer_set(fsp, rec_tov);
1540		} else {
1541
1542			/*
1543			 * The exchange is incomplete, we have seq. initiative.
1544			 * Lost response with requested confirmation,
1545			 * lost confirmation, lost transfer ready or
1546			 * lost write data.
1547			 *
1548			 * For output, if not all data was received, ask
1549			 * for transfer ready to be repeated.
1550			 *
1551			 * If we received or sent all the data, send SRR to
1552			 * request response.
1553			 *
1554			 * If we lost a response, we may have lost some read
1555			 * data as well.
1556			 */
1557			r_ctl = FC_RCTL_DD_SOL_DATA;
1558			if (data_dir == DMA_TO_DEVICE) {
1559				r_ctl = FC_RCTL_DD_CMD_STATUS;
1560				if (offset < fsp->data_len)
1561					r_ctl = FC_RCTL_DD_DATA_DESC;
1562			} else if (offset == fsp->xfer_contig_end) {
1563				r_ctl = FC_RCTL_DD_CMD_STATUS;
1564			} else if (fsp->xfer_contig_end < offset) {
1565				offset = fsp->xfer_contig_end;
1566			}
1567			fc_fcp_srr(fsp, r_ctl, offset);
1568		}
1569	}
1570unlock_out:
1571	fc_fcp_unlock_pkt(fsp);
1572out:
1573	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
1574	fc_frame_free(fp);
1575}
1576
1577/**
1578 * fc_fcp_rec_error() - Handler for REC errors
1579 * @fsp: The FCP packet the error is on
1580 * @fp:	 The REC frame
1581 */
1582static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1583{
1584	int error = PTR_ERR(fp);
1585
1586	if (fc_fcp_lock_pkt(fsp))
1587		goto out;
1588
1589	switch (error) {
1590	case -FC_EX_CLOSED:
1591		fc_fcp_retry_cmd(fsp);
1592		break;
1593
1594	default:
1595		FC_FCP_DBG(fsp, "REC %p fid %6.6x error unexpected error %d\n",
1596			   fsp, fsp->rport->port_id, error);
1597		fsp->status_code = FC_CMD_PLOGO;
1598		/* fall through */
1599
1600	case -FC_EX_TIMEOUT:
1601		/*
1602		 * Assume REC or LS_ACC was lost.
1603		 * The exchange manager will have aborted REC, so retry.
1604		 */
1605		FC_FCP_DBG(fsp, "REC fid %6.6x error error %d retry %d/%d\n",
1606			   fsp->rport->port_id, error, fsp->recov_retry,
1607			   FC_MAX_RECOV_RETRY);
1608		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1609			fc_fcp_rec(fsp);
1610		else
1611			fc_fcp_recovery(fsp, FC_ERROR);
1612		break;
1613	}
1614	fc_fcp_unlock_pkt(fsp);
1615out:
1616	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
1617}
1618
1619/**
1620 * fc_fcp_recovery() - Handler for fcp_pkt recovery
1621 * @fsp: The FCP pkt that needs to be aborted
1622 */
1623static void fc_fcp_recovery(struct fc_fcp_pkt *fsp, u8 code)
1624{
1625	fsp->status_code = code;
1626	fsp->cdb_status = 0;
1627	fsp->io_status = 0;
1628	/*
1629	 * if this fails then we let the scsi command timer fire and
1630	 * scsi-ml escalate.
1631	 */
1632	fc_fcp_send_abort(fsp);
1633}
1634
1635/**
1636 * fc_fcp_srr() - Send a SRR request (Sequence Retransmission Request)
1637 * @fsp:   The FCP packet the SRR is to be sent on
1638 * @r_ctl: The R_CTL field for the SRR request
1639 * This is called after receiving status but insufficient data, or
1640 * when expecting status but the request has timed out.
1641 */
1642static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
1643{
1644	struct fc_lport *lport = fsp->lp;
1645	struct fc_rport *rport;
1646	struct fc_rport_libfc_priv *rpriv;
1647	struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1648	struct fc_seq *seq;
1649	struct fcp_srr *srr;
1650	struct fc_frame *fp;
1651	u8 cdb_op;
1652	unsigned int rec_tov;
1653
1654	rport = fsp->rport;
1655	rpriv = rport->dd_data;
1656	cdb_op = fsp->cdb_cmd.fc_cdb[0];
1657
1658	if (!(rpriv->flags & FC_RP_FLAGS_RETRY) ||
1659	    rpriv->rp_state != RPORT_ST_READY)
1660		goto retry;			/* shouldn't happen */
1661	fp = fc_fcp_frame_alloc(lport, sizeof(*srr));
1662	if (!fp)
1663		goto retry;
1664
1665	srr = fc_frame_payload_get(fp, sizeof(*srr));
1666	memset(srr, 0, sizeof(*srr));
1667	srr->srr_op = ELS_SRR;
1668	srr->srr_ox_id = htons(ep->oxid);
1669	srr->srr_rx_id = htons(ep->rxid);
1670	srr->srr_r_ctl = r_ctl;
1671	srr->srr_rel_off = htonl(offset);
1672
1673	fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
1674		       rpriv->local_port->port_id, FC_TYPE_FCP,
1675		       FC_FCTL_REQ, 0);
1676
1677	rec_tov = get_fsp_rec_tov(fsp);
1678	seq = lport->tt.exch_seq_send(lport, fp, fc_fcp_srr_resp, NULL,
1679				      fsp, jiffies_to_msecs(rec_tov));
1680	if (!seq)
1681		goto retry;
1682
1683	fsp->recov_seq = seq;
1684	fsp->xfer_len = offset;
1685	fsp->xfer_contig_end = offset;
1686	fsp->state &= ~FC_SRB_RCV_STATUS;
1687	fc_fcp_pkt_hold(fsp);		/* hold for outstanding SRR */
1688	return;
1689retry:
1690	fc_fcp_retry_cmd(fsp);
1691}
1692
1693/**
1694 * fc_fcp_srr_resp() - Handler for SRR response
1695 * @seq: The sequence the SRR is on
1696 * @fp:	 The SRR frame
1697 * @arg: The FCP packet the SRR is on
1698 */
1699static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1700{
1701	struct fc_fcp_pkt *fsp = arg;
1702	struct fc_frame_header *fh;
1703	unsigned int rec_tov;
1704
1705	if (IS_ERR(fp)) {
1706		fc_fcp_srr_error(fsp, fp);
1707		return;
1708	}
1709
1710	if (fc_fcp_lock_pkt(fsp))
1711		goto out;
1712
1713	fh = fc_frame_header_get(fp);
1714	/*
1715	 * BUG? fc_fcp_srr_error calls exch_done which would release
1716	 * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
1717	 * then fc_exch_timeout would be sending an abort. The exch_done
1718	 * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
1719	 * an abort response though.
1720	 */
1721	if (fh->fh_type == FC_TYPE_BLS) {
1722		fc_fcp_unlock_pkt(fsp);
1723		return;
1724	}
1725
1726	fsp->recov_seq = NULL;
1727	switch (fc_frame_payload_op(fp)) {
1728	case ELS_LS_ACC:
1729		fsp->recov_retry = 0;
1730		rec_tov = get_fsp_rec_tov(fsp);
1731		fc_fcp_timer_set(fsp, rec_tov);
1732		break;
1733	case ELS_LS_RJT:
1734	default:
1735		fc_fcp_recovery(fsp, FC_ERROR);
1736		break;
1737	}
1738	fc_fcp_unlock_pkt(fsp);
1739	fsp->lp->tt.exch_done(seq);
1740out:
1741	fc_frame_free(fp);
1742	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding SRR */
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	fsp->lp->tt.exch_done(fsp->recov_seq);
1755	fsp->recov_seq = NULL;
1756	switch (PTR_ERR(fp)) {
1757	case -FC_EX_TIMEOUT:
1758		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1759			fc_fcp_rec(fsp);
1760		else
1761			fc_fcp_recovery(fsp, FC_TIMED_OUT);
1762		break;
1763	case -FC_EX_CLOSED:			/* e.g., link failure */
1764		/* fall through */
1765	default:
1766		fc_fcp_retry_cmd(fsp);
1767		break;
1768	}
1769	fc_fcp_unlock_pkt(fsp);
1770out:
1771	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding SRR */
1772}
1773
1774/**
1775 * fc_fcp_lport_queue_ready() - Determine if the lport and it's queue is ready
1776 * @lport: The local port to be checked
1777 */
1778static inline int fc_fcp_lport_queue_ready(struct fc_lport *lport)
1779{
1780	/* lock ? */
1781	return (lport->state == LPORT_ST_READY) &&
1782		lport->link_up && !lport->qfull;
1783}
1784
1785/**
1786 * fc_queuecommand() - The queuecommand function of the SCSI template
1787 * @cmd:   The scsi_cmnd to be executed
1788 * @done:  The callback function to be called when the scsi_cmnd is complete
1789 *
1790 * This is the i/o strategy routine, called by the SCSI layer. This routine
1791 * is called with the host_lock held.
1792 */
1793static int fc_queuecommand_lck(struct scsi_cmnd *sc_cmd, void (*done)(struct scsi_cmnd *))
1794{
1795	struct fc_lport *lport;
1796	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1797	struct fc_fcp_pkt *fsp;
1798	struct fc_rport_libfc_priv *rpriv;
1799	int rval;
1800	int rc = 0;
1801	struct fcoe_dev_stats *stats;
1802
1803	lport = shost_priv(sc_cmd->device->host);
1804
1805	rval = fc_remote_port_chkready(rport);
1806	if (rval) {
1807		sc_cmd->result = rval;
1808		done(sc_cmd);
1809		return 0;
1810	}
1811	spin_unlock_irq(lport->host->host_lock);
1812
1813	if (!*(struct fc_remote_port **)rport->dd_data) {
1814		/*
1815		 * rport is transitioning from blocked/deleted to
1816		 * online
1817		 */
1818		sc_cmd->result = DID_IMM_RETRY << 16;
1819		done(sc_cmd);
1820		goto out;
1821	}
1822
1823	rpriv = rport->dd_data;
1824
1825	if (!fc_fcp_lport_queue_ready(lport)) {
1826		if (lport->qfull)
1827			fc_fcp_can_queue_ramp_down(lport);
1828		rc = SCSI_MLQUEUE_HOST_BUSY;
1829		goto out;
1830	}
1831
1832	fsp = fc_fcp_pkt_alloc(lport, GFP_ATOMIC);
1833	if (fsp == NULL) {
1834		rc = SCSI_MLQUEUE_HOST_BUSY;
1835		goto out;
1836	}
1837
1838	/*
1839	 * build the libfc request pkt
1840	 */
1841	fsp->cmd = sc_cmd;	/* save the cmd */
1842	fsp->lp = lport;	/* save the softc ptr */
1843	fsp->rport = rport;	/* set the remote port ptr */
1844	fsp->xfer_ddp = FC_XID_UNKNOWN;
1845	sc_cmd->scsi_done = done;
1846
1847	/*
1848	 * set up the transfer length
1849	 */
1850	fsp->data_len = scsi_bufflen(sc_cmd);
1851	fsp->xfer_len = 0;
1852
1853	/*
1854	 * setup the data direction
1855	 */
1856	stats = per_cpu_ptr(lport->dev_stats, get_cpu());
1857	if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
1858		fsp->req_flags = FC_SRB_READ;
1859		stats->InputRequests++;
1860		stats->InputMegabytes += fsp->data_len;
1861	} else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
1862		fsp->req_flags = FC_SRB_WRITE;
1863		stats->OutputRequests++;
1864		stats->OutputMegabytes += fsp->data_len;
1865	} else {
1866		fsp->req_flags = 0;
1867		stats->ControlRequests++;
1868	}
1869	put_cpu();
1870
1871	init_timer(&fsp->timer);
1872	fsp->timer.data = (unsigned long)fsp;
1873
1874	/*
1875	 * send it to the lower layer
1876	 * if we get -1 return then put the request in the pending
1877	 * queue.
1878	 */
1879	rval = fc_fcp_pkt_send(lport, fsp);
1880	if (rval != 0) {
1881		fsp->state = FC_SRB_FREE;
1882		fc_fcp_pkt_release(fsp);
1883		rc = SCSI_MLQUEUE_HOST_BUSY;
1884	}
1885out:
1886	spin_lock_irq(lport->host->host_lock);
1887	return rc;
1888}
1889
1890DEF_SCSI_QCMD(fc_queuecommand)
1891EXPORT_SYMBOL(fc_queuecommand);
1892
1893/**
1894 * fc_io_compl() - Handle responses for completed commands
1895 * @fsp: The FCP packet that is complete
1896 *
1897 * Translates fcp_pkt errors to a Linux SCSI errors.
1898 * The fcp packet lock must be held when calling.
1899 */
1900static void fc_io_compl(struct fc_fcp_pkt *fsp)
1901{
1902	struct fc_fcp_internal *si;
1903	struct scsi_cmnd *sc_cmd;
1904	struct fc_lport *lport;
1905	unsigned long flags;
1906
1907	/* release outstanding ddp context */
1908	fc_fcp_ddp_done(fsp);
1909
1910	fsp->state |= FC_SRB_COMPL;
1911	if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
1912		spin_unlock_bh(&fsp->scsi_pkt_lock);
1913		del_timer_sync(&fsp->timer);
1914		spin_lock_bh(&fsp->scsi_pkt_lock);
1915	}
1916
1917	lport = fsp->lp;
1918	si = fc_get_scsi_internal(lport);
1919
1920	/*
1921	 * if can_queue ramp down is done then try can_queue ramp up
1922	 * since commands are completing now.
1923	 */
1924	if (si->last_can_queue_ramp_down_time)
1925		fc_fcp_can_queue_ramp_up(lport);
1926
1927	sc_cmd = fsp->cmd;
1928	CMD_SCSI_STATUS(sc_cmd) = fsp->cdb_status;
1929	switch (fsp->status_code) {
1930	case FC_COMPLETE:
1931		if (fsp->cdb_status == 0) {
1932			/*
1933			 * good I/O status
1934			 */
1935			sc_cmd->result = DID_OK << 16;
1936			if (fsp->scsi_resid)
1937				CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1938		} else {
1939			/*
1940			 * transport level I/O was ok but scsi
1941			 * has non zero status
1942			 */
1943			sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
1944		}
1945		break;
1946	case FC_ERROR:
1947		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1948			   "due to FC_ERROR\n");
1949		sc_cmd->result = DID_ERROR << 16;
1950		break;
1951	case FC_DATA_UNDRUN:
1952		if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) {
1953			/*
1954			 * scsi status is good but transport level
1955			 * underrun.
1956			 */
1957			if (fsp->state & FC_SRB_RCV_STATUS) {
1958				sc_cmd->result = DID_OK << 16;
1959			} else {
1960				FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml"
1961					   " due to FC_DATA_UNDRUN (trans)\n");
1962				sc_cmd->result = DID_ERROR << 16;
1963			}
1964		} else {
1965			/*
1966			 * scsi got underrun, this is an error
1967			 */
1968			FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1969				   "due to FC_DATA_UNDRUN (scsi)\n");
1970			CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
1971			sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1972		}
1973		break;
1974	case FC_DATA_OVRRUN:
1975		/*
1976		 * overrun is an error
1977		 */
1978		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1979			   "due to FC_DATA_OVRRUN\n");
1980		sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
1981		break;
1982	case FC_CMD_ABORTED:
1983		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
1984			  "due to FC_CMD_ABORTED\n");
1985		sc_cmd->result = (DID_ERROR << 16) | fsp->io_status;
1986		break;
1987	case FC_CMD_RESET:
1988		FC_FCP_DBG(fsp, "Returning DID_RESET to scsi-ml "
1989			   "due to FC_CMD_RESET\n");
1990		sc_cmd->result = (DID_RESET << 16);
1991		break;
1992	case FC_HRD_ERROR:
1993		FC_FCP_DBG(fsp, "Returning DID_NO_CONNECT to scsi-ml "
1994			   "due to FC_HRD_ERROR\n");
1995		sc_cmd->result = (DID_NO_CONNECT << 16);
1996		break;
1997	case FC_CRC_ERROR:
1998		FC_FCP_DBG(fsp, "Returning DID_PARITY to scsi-ml "
1999			   "due to FC_CRC_ERROR\n");
2000		sc_cmd->result = (DID_PARITY << 16);
2001		break;
2002	case FC_TIMED_OUT:
2003		FC_FCP_DBG(fsp, "Returning DID_BUS_BUSY to scsi-ml "
2004			   "due to FC_TIMED_OUT\n");
2005		sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
2006		break;
2007	default:
2008		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2009			   "due to unknown error\n");
2010		sc_cmd->result = (DID_ERROR << 16);
2011		break;
2012	}
2013
2014	if (lport->state != LPORT_ST_READY && fsp->status_code != FC_COMPLETE)
2015		sc_cmd->result = (DID_TRANSPORT_DISRUPTED << 16);
2016
2017	spin_lock_irqsave(&si->scsi_queue_lock, flags);
2018	list_del(&fsp->list);
2019	sc_cmd->SCp.ptr = NULL;
2020	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2021	sc_cmd->scsi_done(sc_cmd);
2022
2023	/* release ref from initial allocation in queue command */
2024	fc_fcp_pkt_release(fsp);
2025}
2026
2027/**
2028 * fc_eh_abort() - Abort a command
2029 * @sc_cmd: The SCSI command to abort
2030 *
2031 * From SCSI host template.
2032 * Send an ABTS to the target device and wait for the response.
2033 */
2034int fc_eh_abort(struct scsi_cmnd *sc_cmd)
2035{
2036	struct fc_fcp_pkt *fsp;
2037	struct fc_lport *lport;
2038	struct fc_fcp_internal *si;
2039	int rc = FAILED;
2040	unsigned long flags;
2041
2042	lport = shost_priv(sc_cmd->device->host);
2043	if (lport->state != LPORT_ST_READY)
2044		return rc;
2045	else if (!lport->link_up)
2046		return rc;
2047
2048	si = fc_get_scsi_internal(lport);
2049	spin_lock_irqsave(&si->scsi_queue_lock, flags);
2050	fsp = CMD_SP(sc_cmd);
2051	if (!fsp) {
2052		/* command completed while scsi eh was setting up */
2053		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2054		return SUCCESS;
2055	}
2056	/* grab a ref so the fsp and sc_cmd cannot be relased from under us */
2057	fc_fcp_pkt_hold(fsp);
2058	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2059
2060	if (fc_fcp_lock_pkt(fsp)) {
2061		/* completed while we were waiting for timer to be deleted */
2062		rc = SUCCESS;
2063		goto release_pkt;
2064	}
2065
2066	rc = fc_fcp_pkt_abort(fsp);
2067	fc_fcp_unlock_pkt(fsp);
2068
2069release_pkt:
2070	fc_fcp_pkt_release(fsp);
2071	return rc;
2072}
2073EXPORT_SYMBOL(fc_eh_abort);
2074
2075/**
2076 * fc_eh_device_reset() - Reset a single LUN
2077 * @sc_cmd: The SCSI command which identifies the device whose
2078 *	    LUN is to be reset
2079 *
2080 * Set from SCSI host template.
2081 */
2082int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
2083{
2084	struct fc_lport *lport;
2085	struct fc_fcp_pkt *fsp;
2086	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
2087	int rc = FAILED;
2088	int rval;
2089
2090	rval = fc_remote_port_chkready(rport);
2091	if (rval)
2092		goto out;
2093
2094	lport = shost_priv(sc_cmd->device->host);
2095
2096	if (lport->state != LPORT_ST_READY)
2097		return rc;
2098
2099	FC_SCSI_DBG(lport, "Resetting rport (%6.6x)\n", rport->port_id);
2100
2101	fsp = fc_fcp_pkt_alloc(lport, GFP_NOIO);
2102	if (fsp == NULL) {
2103		printk(KERN_WARNING "libfc: could not allocate scsi_pkt\n");
2104		goto out;
2105	}
2106
2107	/*
2108	 * Build the libfc request pkt. Do not set the scsi cmnd, because
2109	 * the sc passed in is not setup for execution like when sent
2110	 * through the queuecommand callout.
2111	 */
2112	fsp->lp = lport;	/* save the softc ptr */
2113	fsp->rport = rport;	/* set the remote port ptr */
2114
2115	/*
2116	 * flush outstanding commands
2117	 */
2118	rc = fc_lun_reset(lport, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
2119	fsp->state = FC_SRB_FREE;
2120	fc_fcp_pkt_release(fsp);
2121
2122out:
2123	return rc;
2124}
2125EXPORT_SYMBOL(fc_eh_device_reset);
2126
2127/**
2128 * fc_eh_host_reset() - Reset a Scsi_Host.
2129 * @sc_cmd: The SCSI command that identifies the SCSI host to be reset
2130 */
2131int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
2132{
2133	struct Scsi_Host *shost = sc_cmd->device->host;
2134	struct fc_lport *lport = shost_priv(shost);
2135	unsigned long wait_tmo;
2136
2137	FC_SCSI_DBG(lport, "Resetting host\n");
2138
2139	lport->tt.lport_reset(lport);
2140	wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
2141	while (!fc_fcp_lport_queue_ready(lport) && time_before(jiffies,
2142							       wait_tmo))
2143		msleep(1000);
2144
2145	if (fc_fcp_lport_queue_ready(lport)) {
2146		shost_printk(KERN_INFO, shost, "libfc: Host reset succeeded "
2147			     "on port (%6.6x)\n", lport->port_id);
2148		return SUCCESS;
2149	} else {
2150		shost_printk(KERN_INFO, shost, "libfc: Host reset failed, "
2151			     "port (%6.6x) is not ready.\n",
2152			     lport->port_id);
2153		return FAILED;
2154	}
2155}
2156EXPORT_SYMBOL(fc_eh_host_reset);
2157
2158/**
2159 * fc_slave_alloc() - Configure the queue depth of a Scsi_Host
2160 * @sdev: The SCSI device that identifies the SCSI host
2161 *
2162 * Configures queue depth based on host's cmd_per_len. If not set
2163 * then we use the libfc default.
2164 */
2165int fc_slave_alloc(struct scsi_device *sdev)
2166{
2167	struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
2168
2169	if (!rport || fc_remote_port_chkready(rport))
2170		return -ENXIO;
2171
2172	if (sdev->tagged_supported)
2173		scsi_activate_tcq(sdev, FC_FCP_DFLT_QUEUE_DEPTH);
2174	else
2175		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev),
2176					FC_FCP_DFLT_QUEUE_DEPTH);
2177
2178	return 0;
2179}
2180EXPORT_SYMBOL(fc_slave_alloc);
2181
2182/**
2183 * fc_change_queue_depth() - Change a device's queue depth
2184 * @sdev:   The SCSI device whose queue depth is to change
2185 * @qdepth: The new queue depth
2186 * @reason: The resason for the change
2187 */
2188int fc_change_queue_depth(struct scsi_device *sdev, int qdepth, int reason)
2189{
2190	switch (reason) {
2191	case SCSI_QDEPTH_DEFAULT:
2192		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);
2193		break;
2194	case SCSI_QDEPTH_QFULL:
2195		scsi_track_queue_full(sdev, qdepth);
2196		break;
2197	case SCSI_QDEPTH_RAMP_UP:
2198		scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);
2199		break;
2200	default:
2201		return -EOPNOTSUPP;
2202	}
2203	return sdev->queue_depth;
2204}
2205EXPORT_SYMBOL(fc_change_queue_depth);
2206
2207/**
2208 * fc_change_queue_type() - Change a device's queue type
2209 * @sdev:     The SCSI device whose queue depth is to change
2210 * @tag_type: Identifier for queue type
2211 */
2212int fc_change_queue_type(struct scsi_device *sdev, int tag_type)
2213{
2214	if (sdev->tagged_supported) {
2215		scsi_set_tag_type(sdev, tag_type);
2216		if (tag_type)
2217			scsi_activate_tcq(sdev, sdev->queue_depth);
2218		else
2219			scsi_deactivate_tcq(sdev, sdev->queue_depth);
2220	} else
2221		tag_type = 0;
2222
2223	return tag_type;
2224}
2225EXPORT_SYMBOL(fc_change_queue_type);
2226
2227/**
2228 * fc_fcp_destory() - Tear down the FCP layer for a given local port
2229 * @lport: The local port that no longer needs the FCP layer
2230 */
2231void fc_fcp_destroy(struct fc_lport *lport)
2232{
2233	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
2234
2235	if (!list_empty(&si->scsi_pkt_queue))
2236		printk(KERN_ERR "libfc: Leaked SCSI packets when destroying "
2237		       "port (%6.6x)\n", lport->port_id);
2238
2239	mempool_destroy(si->scsi_pkt_pool);
2240	kfree(si);
2241	lport->scsi_priv = NULL;
2242}
2243EXPORT_SYMBOL(fc_fcp_destroy);
2244
2245int fc_setup_fcp()
2246{
2247	int rc = 0;
2248
2249	scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
2250					    sizeof(struct fc_fcp_pkt),
2251					    0, SLAB_HWCACHE_ALIGN, NULL);
2252	if (!scsi_pkt_cachep) {
2253		printk(KERN_ERR "libfc: Unable to allocate SRB cache, "
2254		       "module load failed!");
2255		rc = -ENOMEM;
2256	}
2257
2258	return rc;
2259}
2260
2261void fc_destroy_fcp()
2262{
2263	if (scsi_pkt_cachep)
2264		kmem_cache_destroy(scsi_pkt_cachep);
2265}
2266
2267/**
2268 * fc_fcp_init() - Initialize the FCP layer for a local port
2269 * @lport: The local port to initialize the exchange layer for
2270 */
2271int fc_fcp_init(struct fc_lport *lport)
2272{
2273	int rc;
2274	struct fc_fcp_internal *si;
2275
2276	if (!lport->tt.fcp_cmd_send)
2277		lport->tt.fcp_cmd_send = fc_fcp_cmd_send;
2278
2279	if (!lport->tt.fcp_cleanup)
2280		lport->tt.fcp_cleanup = fc_fcp_cleanup;
2281
2282	if (!lport->tt.fcp_abort_io)
2283		lport->tt.fcp_abort_io = fc_fcp_abort_io;
2284
2285	si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
2286	if (!si)
2287		return -ENOMEM;
2288	lport->scsi_priv = si;
2289	si->max_can_queue = lport->host->can_queue;
2290	INIT_LIST_HEAD(&si->scsi_pkt_queue);
2291	spin_lock_init(&si->scsi_queue_lock);
2292
2293	si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
2294	if (!si->scsi_pkt_pool) {
2295		rc = -ENOMEM;
2296		goto free_internal;
2297	}
2298	return 0;
2299
2300free_internal:
2301	kfree(si);
2302	return rc;
2303}
2304EXPORT_SYMBOL(fc_fcp_init);
2305