1/*
2 * Copyright(c) 2007 Intel Corporation. All rights reserved.
3 * Copyright(c) 2008 Red Hat, Inc.  All rights reserved.
4 * Copyright(c) 2008 Mike Christie
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Maintained at www.Open-FCoE.org
20 */
21
22#include <linux/module.h>
23#include <linux/delay.h>
24#include <linux/kernel.h>
25#include <linux/types.h>
26#include <linux/spinlock.h>
27#include <linux/scatterlist.h>
28#include <linux/err.h>
29#include <linux/crc32.h>
30#include <linux/slab.h>
31
32#include <scsi/scsi_tcq.h>
33#include <scsi/scsi.h>
34#include <scsi/scsi_host.h>
35#include <scsi/scsi_device.h>
36#include <scsi/scsi_cmnd.h>
37
38#include <scsi/fc/fc_fc2.h>
39
40#include <scsi/libfc.h>
41#include <scsi/fc_encode.h>
42
43#include "fc_libfc.h"
44
45static struct kmem_cache *scsi_pkt_cachep;
46
47/* SRB state definitions */
48#define FC_SRB_FREE		0		/* cmd is free */
49#define FC_SRB_CMD_SENT		(1 << 0)	/* cmd has been sent */
50#define FC_SRB_RCV_STATUS	(1 << 1)	/* response has arrived */
51#define FC_SRB_ABORT_PENDING	(1 << 2)	/* cmd abort sent to device */
52#define FC_SRB_ABORTED		(1 << 3)	/* abort acknowledged */
53#define FC_SRB_DISCONTIG	(1 << 4)	/* non-sequential data recvd */
54#define FC_SRB_COMPL		(1 << 5)	/* fc_io_compl has been run */
55#define FC_SRB_FCP_PROCESSING_TMO (1 << 6)	/* timer function processing */
56
57#define FC_SRB_READ		(1 << 1)
58#define FC_SRB_WRITE		(1 << 0)
59
60/*
61 * The SCp.ptr should be tested and set under the scsi_pkt_queue lock
62 */
63#define CMD_SP(Cmnd)		    ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)
64#define CMD_ENTRY_STATUS(Cmnd)	    ((Cmnd)->SCp.have_data_in)
65#define CMD_COMPL_STATUS(Cmnd)	    ((Cmnd)->SCp.this_residual)
66#define CMD_SCSI_STATUS(Cmnd)	    ((Cmnd)->SCp.Status)
67#define CMD_RESID_LEN(Cmnd)	    ((Cmnd)->SCp.buffers_residual)
68
69/**
70 * struct fc_fcp_internal - FCP layer internal data
71 * @scsi_pkt_pool: Memory pool to draw FCP packets from
72 * @scsi_queue_lock: Protects the scsi_pkt_queue
73 * @scsi_pkt_queue: Current FCP packets
74 * @last_can_queue_ramp_down_time: ramp down time
75 * @last_can_queue_ramp_up_time: ramp up time
76 * @max_can_queue: max can_queue size
77 */
78struct fc_fcp_internal {
79	mempool_t		*scsi_pkt_pool;
80	spinlock_t		scsi_queue_lock;
81	struct list_head	scsi_pkt_queue;
82	unsigned long		last_can_queue_ramp_down_time;
83	unsigned long		last_can_queue_ramp_up_time;
84	int			max_can_queue;
85};
86
87#define fc_get_scsi_internal(x)	((struct fc_fcp_internal *)(x)->scsi_priv)
88
89/*
90 * function prototypes
91 * FC scsi I/O related functions
92 */
93static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
94static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
95static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
96static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
97static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
98static void fc_fcp_error(struct fc_fcp_pkt *, struct fc_frame *);
99static void fc_fcp_recovery(struct fc_fcp_pkt *, u8 code);
100static void fc_fcp_timeout(unsigned long);
101static void fc_fcp_rec(struct fc_fcp_pkt *);
102static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
103static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
104static void fc_io_compl(struct fc_fcp_pkt *);
105
106static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
107static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
108static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
109
110/*
111 * command status codes
112 */
113#define FC_COMPLETE		0
114#define FC_CMD_ABORTED		1
115#define FC_CMD_RESET		2
116#define FC_CMD_PLOGO		3
117#define FC_SNS_RCV		4
118#define FC_TRANS_ERR		5
119#define FC_DATA_OVRRUN		6
120#define FC_DATA_UNDRUN		7
121#define FC_ERROR		8
122#define FC_HRD_ERROR		9
123#define FC_CRC_ERROR		10
124#define FC_TIMED_OUT		11
125
126/*
127 * Error recovery timeout values.
128 */
129#define FC_SCSI_TM_TOV		(10 * HZ)
130#define FC_HOST_RESET_TIMEOUT	(30 * HZ)
131#define FC_CAN_QUEUE_PERIOD	(60 * HZ)
132
133#define FC_MAX_ERROR_CNT	5
134#define FC_MAX_RECOV_RETRY	3
135
136#define FC_FCP_DFLT_QUEUE_DEPTH 32
137
138/**
139 * fc_fcp_pkt_alloc() - Allocate a fcp_pkt
140 * @lport: The local port that the FCP packet is for
141 * @gfp:   GFP flags for allocation
142 *
143 * Return value: fcp_pkt structure or null on allocation failure.
144 * Context:	 Can be called from process context, no lock is required.
145 */
146static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lport, gfp_t gfp)
147{
148	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
149	struct fc_fcp_pkt *fsp;
150
151	fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
152	if (fsp) {
153		memset(fsp, 0, sizeof(*fsp));
154		fsp->lp = lport;
155		fsp->xfer_ddp = FC_XID_UNKNOWN;
156		atomic_set(&fsp->ref_cnt, 1);
157		init_timer(&fsp->timer);
158		fsp->timer.data = (unsigned long)fsp;
159		INIT_LIST_HEAD(&fsp->list);
160		spin_lock_init(&fsp->scsi_pkt_lock);
161	} else {
162		per_cpu_ptr(lport->stats, get_cpu())->FcpPktAllocFails++;
163		put_cpu();
164	}
165	return fsp;
166}
167
168/**
169 * fc_fcp_pkt_release() - Release hold on a fcp_pkt
170 * @fsp: The FCP packet to be released
171 *
172 * Context: Can be called from process or interrupt context,
173 *	    no lock is required.
174 */
175static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
176{
177	if (atomic_dec_and_test(&fsp->ref_cnt)) {
178		struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
179
180		mempool_free(fsp, si->scsi_pkt_pool);
181	}
182}
183
184/**
185 * fc_fcp_pkt_hold() - Hold a fcp_pkt
186 * @fsp: The FCP packet to be held
187 */
188static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
189{
190	atomic_inc(&fsp->ref_cnt);
191}
192
193/**
194 * fc_fcp_pkt_destroy() - Release hold on a fcp_pkt
195 * @seq: The sequence that the FCP packet is on (required by destructor API)
196 * @fsp: The FCP packet to be released
197 *
198 * This routine is called by a destructor callback in the exch_seq_send()
199 * routine of the libfc Transport Template. The 'struct fc_seq' is a required
200 * argument even though it is not used by this routine.
201 *
202 * Context: No locking required.
203 */
204static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
205{
206	fc_fcp_pkt_release(fsp);
207}
208
209/**
210 * fc_fcp_lock_pkt() - Lock a fcp_pkt and increase its reference count
211 * @fsp: The FCP packet to be locked and incremented
212 *
213 * We should only return error if we return a command to SCSI-ml before
214 * getting a response. This can happen in cases where we send a abort, but
215 * do not wait for the response and the abort and command can be passing
216 * each other on the wire/network-layer.
217 *
218 * Note: this function locks the packet and gets a reference to allow
219 * callers to call the completion function while the lock is held and
220 * not have to worry about the packets refcount.
221 *
222 * TODO: Maybe we should just have callers grab/release the lock and
223 * have a function that they call to verify the fsp and grab a ref if
224 * needed.
225 */
226static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
227{
228	spin_lock_bh(&fsp->scsi_pkt_lock);
229	if (fsp->state & FC_SRB_COMPL) {
230		spin_unlock_bh(&fsp->scsi_pkt_lock);
231		return -EPERM;
232	}
233
234	fc_fcp_pkt_hold(fsp);
235	return 0;
236}
237
238/**
239 * fc_fcp_unlock_pkt() - Release a fcp_pkt's lock and decrement its
240 *			 reference count
241 * @fsp: The FCP packet to be unlocked and decremented
242 */
243static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
244{
245	spin_unlock_bh(&fsp->scsi_pkt_lock);
246	fc_fcp_pkt_release(fsp);
247}
248
249/**
250 * fc_fcp_timer_set() - Start a timer for a fcp_pkt
251 * @fsp:   The FCP packet to start a timer for
252 * @delay: The timeout period in jiffies
253 */
254static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
255{
256	if (!(fsp->state & FC_SRB_COMPL))
257		mod_timer(&fsp->timer, jiffies + delay);
258}
259
260/**
261 * fc_fcp_send_abort() - Send an abort for exchanges associated with a
262 *			 fcp_pkt
263 * @fsp: The FCP packet to abort exchanges on
264 */
265static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
266{
267	if (!fsp->seq_ptr)
268		return -EINVAL;
269
270	per_cpu_ptr(fsp->lp->stats, get_cpu())->FcpPktAborts++;
271	put_cpu();
272
273	fsp->state |= FC_SRB_ABORT_PENDING;
274	return fsp->lp->tt.seq_exch_abort(fsp->seq_ptr, 0);
275}
276
277/**
278 * fc_fcp_retry_cmd() - Retry a fcp_pkt
279 * @fsp: The FCP packet to be retried
280 *
281 * Sets the status code to be FC_ERROR and then calls
282 * fc_fcp_complete_locked() which in turn calls fc_io_compl().
283 * fc_io_compl() will notify the SCSI-ml that the I/O is done.
284 * The SCSI-ml will retry the command.
285 */
286static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp)
287{
288	if (fsp->seq_ptr) {
289		fsp->lp->tt.exch_done(fsp->seq_ptr);
290		fsp->seq_ptr = NULL;
291	}
292
293	fsp->state &= ~FC_SRB_ABORT_PENDING;
294	fsp->io_status = 0;
295	fsp->status_code = FC_ERROR;
296	fc_fcp_complete_locked(fsp);
297}
298
299/**
300 * fc_fcp_ddp_setup() - Calls a LLD's ddp_setup routine to set up DDP context
301 * @fsp: The FCP packet that will manage the DDP frames
302 * @xid: The XID that will be used for the DDP exchange
303 */
304void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
305{
306	struct fc_lport *lport;
307
308	lport = fsp->lp;
309	if ((fsp->req_flags & FC_SRB_READ) &&
310	    (lport->lro_enabled) && (lport->tt.ddp_setup)) {
311		if (lport->tt.ddp_setup(lport, xid, scsi_sglist(fsp->cmd),
312					scsi_sg_count(fsp->cmd)))
313			fsp->xfer_ddp = xid;
314	}
315}
316
317/**
318 * fc_fcp_ddp_done() - Calls a LLD's ddp_done routine to release any
319 *		       DDP related resources for a fcp_pkt
320 * @fsp: The FCP packet that DDP had been used on
321 */
322void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
323{
324	struct fc_lport *lport;
325
326	if (!fsp)
327		return;
328
329	if (fsp->xfer_ddp == FC_XID_UNKNOWN)
330		return;
331
332	lport = fsp->lp;
333	if (lport->tt.ddp_done) {
334		fsp->xfer_len = lport->tt.ddp_done(lport, fsp->xfer_ddp);
335		fsp->xfer_ddp = FC_XID_UNKNOWN;
336	}
337}
338
339/**
340 * fc_fcp_can_queue_ramp_up() - increases can_queue
341 * @lport: lport to ramp up can_queue
342 */
343static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
344{
345	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
346	unsigned long flags;
347	int can_queue;
348
349	spin_lock_irqsave(lport->host->host_lock, flags);
350
351	if (si->last_can_queue_ramp_up_time &&
352	    (time_before(jiffies, si->last_can_queue_ramp_up_time +
353			 FC_CAN_QUEUE_PERIOD)))
354		goto unlock;
355
356	if (time_before(jiffies, si->last_can_queue_ramp_down_time +
357			FC_CAN_QUEUE_PERIOD))
358		goto unlock;
359
360	si->last_can_queue_ramp_up_time = jiffies;
361
362	can_queue = lport->host->can_queue << 1;
363	if (can_queue >= si->max_can_queue) {
364		can_queue = si->max_can_queue;
365		si->last_can_queue_ramp_down_time = 0;
366	}
367	lport->host->can_queue = can_queue;
368	shost_printk(KERN_ERR, lport->host, "libfc: increased "
369		     "can_queue to %d.\n", can_queue);
370
371unlock:
372	spin_unlock_irqrestore(lport->host->host_lock, flags);
373}
374
375/**
376 * fc_fcp_can_queue_ramp_down() - reduces can_queue
377 * @lport: lport to reduce can_queue
378 *
379 * If we are getting memory allocation failures, then we may
380 * be trying to execute too many commands. We let the running
381 * commands complete or timeout, then try again with a reduced
382 * can_queue. Eventually we will hit the point where we run
383 * on all reserved structs.
384 */
385static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport)
386{
387	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
388	unsigned long flags;
389	int can_queue;
390
391	spin_lock_irqsave(lport->host->host_lock, flags);
392
393	if (si->last_can_queue_ramp_down_time &&
394	    (time_before(jiffies, si->last_can_queue_ramp_down_time +
395			 FC_CAN_QUEUE_PERIOD)))
396		goto unlock;
397
398	si->last_can_queue_ramp_down_time = jiffies;
399
400	can_queue = lport->host->can_queue;
401	can_queue >>= 1;
402	if (!can_queue)
403		can_queue = 1;
404	lport->host->can_queue = can_queue;
405	shost_printk(KERN_ERR, lport->host, "libfc: Could not allocate frame.\n"
406		     "Reducing can_queue to %d.\n", can_queue);
407
408unlock:
409	spin_unlock_irqrestore(lport->host->host_lock, flags);
410}
411
412/*
413 * fc_fcp_frame_alloc() -  Allocates fc_frame structure and buffer.
414 * @lport:	fc lport struct
415 * @len:	payload length
416 *
417 * Allocates fc_frame structure and buffer but if fails to allocate
418 * then reduce can_queue.
419 */
420static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport,
421						  size_t len)
422{
423	struct fc_frame *fp;
424
425	fp = fc_frame_alloc(lport, len);
426	if (likely(fp))
427		return fp;
428
429	per_cpu_ptr(lport->stats, get_cpu())->FcpFrameAllocFails++;
430	put_cpu();
431	/* error case */
432	fc_fcp_can_queue_ramp_down(lport);
433	return NULL;
434}
435
436/**
437 * fc_fcp_recv_data() - Handler for receiving SCSI-FCP data from a target
438 * @fsp: The FCP packet the data is on
439 * @fp:	 The data frame
440 */
441static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
442{
443	struct scsi_cmnd *sc = fsp->cmd;
444	struct fc_lport *lport = fsp->lp;
445	struct fc_stats *stats;
446	struct fc_frame_header *fh;
447	size_t start_offset;
448	size_t offset;
449	u32 crc;
450	u32 copy_len = 0;
451	size_t len;
452	void *buf;
453	struct scatterlist *sg;
454	u32 nents;
455	u8 host_bcode = FC_COMPLETE;
456
457	fh = fc_frame_header_get(fp);
458	offset = ntohl(fh->fh_parm_offset);
459	start_offset = offset;
460	len = fr_len(fp) - sizeof(*fh);
461	buf = fc_frame_payload_get(fp, 0);
462
463	/*
464	 * if this I/O is ddped then clear it and initiate recovery since data
465	 * frames are expected to be placed directly in that case.
466	 *
467	 * Indicate error to scsi-ml because something went wrong with the
468	 * ddp handling to get us here.
469	 */
470	if (fsp->xfer_ddp != FC_XID_UNKNOWN) {
471		fc_fcp_ddp_done(fsp);
472		FC_FCP_DBG(fsp, "DDP I/O in fc_fcp_recv_data set ERROR\n");
473		host_bcode = FC_ERROR;
474		goto err;
475	}
476	if (offset + len > fsp->data_len) {
477		/* this should never happen */
478		if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
479		    fc_frame_crc_check(fp))
480			goto crc_err;
481		FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
482			   "data_len %x\n", len, offset, fsp->data_len);
483
484		/* Data is corrupted indicate scsi-ml should retry */
485		host_bcode = FC_DATA_OVRRUN;
486		goto err;
487	}
488	if (offset != fsp->xfer_len)
489		fsp->state |= FC_SRB_DISCONTIG;
490
491	sg = scsi_sglist(sc);
492	nents = scsi_sg_count(sc);
493
494	if (!(fr_flags(fp) & FCPHF_CRC_UNCHECKED)) {
495		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
496						    &offset, NULL);
497	} else {
498		crc = crc32(~0, (u8 *) fh, sizeof(*fh));
499		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
500						    &offset, &crc);
501		buf = fc_frame_payload_get(fp, 0);
502		if (len % 4)
503			crc = crc32(crc, buf + len, 4 - (len % 4));
504
505		if (~crc != le32_to_cpu(fr_crc(fp))) {
506crc_err:
507			stats = per_cpu_ptr(lport->stats, get_cpu());
508			stats->ErrorFrames++;
509			/* per cpu count, not total count, but OK for limit */
510			if (stats->InvalidCRCCount++ < FC_MAX_ERROR_CNT)
511				printk(KERN_WARNING "libfc: CRC error on data "
512				       "frame for port (%6.6x)\n",
513				       lport->port_id);
514			put_cpu();
515			/*
516			 * Assume the frame is total garbage.
517			 * We may have copied it over the good part
518			 * of the buffer.
519			 * If so, we need to retry the entire operation.
520			 * Otherwise, ignore it.
521			 */
522			if (fsp->state & FC_SRB_DISCONTIG) {
523				host_bcode = FC_CRC_ERROR;
524				goto err;
525			}
526			return;
527		}
528	}
529
530	if (fsp->xfer_contig_end == start_offset)
531		fsp->xfer_contig_end += copy_len;
532	fsp->xfer_len += copy_len;
533
534	/*
535	 * In the very rare event that this data arrived after the response
536	 * and completes the transfer, call the completion handler.
537	 */
538	if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
539	    fsp->xfer_len == fsp->data_len - fsp->scsi_resid)
540		fc_fcp_complete_locked(fsp);
541	return;
542err:
543	fc_fcp_recovery(fsp, host_bcode);
544}
545
546/**
547 * fc_fcp_send_data() - Send SCSI data to a target
548 * @fsp:      The FCP packet the data is on
549 * @sp:	      The sequence the data is to be sent on
550 * @offset:   The starting offset for this data request
551 * @seq_blen: The burst length for this data request
552 *
553 * Called after receiving a Transfer Ready data descriptor.
554 * If the LLD is capable of sequence offload then send down the
555 * seq_blen amount of data in single frame, otherwise send
556 * multiple frames of the maximum frame payload supported by
557 * the target port.
558 */
559static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
560			    size_t offset, size_t seq_blen)
561{
562	struct fc_exch *ep;
563	struct scsi_cmnd *sc;
564	struct scatterlist *sg;
565	struct fc_frame *fp = NULL;
566	struct fc_lport *lport = fsp->lp;
567	struct page *page;
568	size_t remaining;
569	size_t t_blen;
570	size_t tlen;
571	size_t sg_bytes;
572	size_t frame_offset, fh_parm_offset;
573	size_t off;
574	int error;
575	void *data = NULL;
576	void *page_addr;
577	int using_sg = lport->sg_supp;
578	u32 f_ctl;
579
580	WARN_ON(seq_blen <= 0);
581	if (unlikely(offset + seq_blen > fsp->data_len)) {
582		/* this should never happen */
583		FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
584			   "offset %zx\n", seq_blen, offset);
585		fc_fcp_send_abort(fsp);
586		return 0;
587	} else if (offset != fsp->xfer_len) {
588		/* Out of Order Data Request - no problem, but unexpected. */
589		FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
590			   "seq_blen %zx offset %zx\n", seq_blen, offset);
591	}
592
593	/*
594	 * if LLD is capable of seq_offload then set transport
595	 * burst length (t_blen) to seq_blen, otherwise set t_blen
596	 * to max FC frame payload previously set in fsp->max_payload.
597	 */
598	t_blen = fsp->max_payload;
599	if (lport->seq_offload) {
600		t_blen = min(seq_blen, (size_t)lport->lso_max);
601		FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
602			   fsp, seq_blen, lport->lso_max, t_blen);
603	}
604
605	if (t_blen > 512)
606		t_blen &= ~(512 - 1);	/* round down to block size */
607	sc = fsp->cmd;
608
609	remaining = seq_blen;
610	fh_parm_offset = frame_offset = offset;
611	tlen = 0;
612	seq = lport->tt.seq_start_next(seq);
613	f_ctl = FC_FC_REL_OFF;
614	WARN_ON(!seq);
615
616	sg = scsi_sglist(sc);
617
618	while (remaining > 0 && sg) {
619		if (offset >= sg->length) {
620			offset -= sg->length;
621			sg = sg_next(sg);
622			continue;
623		}
624		if (!fp) {
625			tlen = min(t_blen, remaining);
626
627			/*
628			 * TODO.  Temporary workaround.	 fc_seq_send() can't
629			 * handle odd lengths in non-linear skbs.
630			 * This will be the final fragment only.
631			 */
632			if (tlen % 4)
633				using_sg = 0;
634			fp = fc_frame_alloc(lport, using_sg ? 0 : tlen);
635			if (!fp)
636				return -ENOMEM;
637
638			data = fc_frame_header_get(fp) + 1;
639			fh_parm_offset = frame_offset;
640			fr_max_payload(fp) = fsp->max_payload;
641		}
642
643		off = offset + sg->offset;
644		sg_bytes = min(tlen, sg->length - offset);
645		sg_bytes = min(sg_bytes,
646			       (size_t) (PAGE_SIZE - (off & ~PAGE_MASK)));
647		page = sg_page(sg) + (off >> PAGE_SHIFT);
648		if (using_sg) {
649			get_page(page);
650			skb_fill_page_desc(fp_skb(fp),
651					   skb_shinfo(fp_skb(fp))->nr_frags,
652					   page, off & ~PAGE_MASK, sg_bytes);
653			fp_skb(fp)->data_len += sg_bytes;
654			fr_len(fp) += sg_bytes;
655			fp_skb(fp)->truesize += PAGE_SIZE;
656		} else {
657			/*
658			 * The scatterlist item may be bigger than PAGE_SIZE,
659			 * but we must not cross pages inside the kmap.
660			 */
661			page_addr = kmap_atomic(page);
662			memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
663			       sg_bytes);
664			kunmap_atomic(page_addr);
665			data += sg_bytes;
666		}
667		offset += sg_bytes;
668		frame_offset += sg_bytes;
669		tlen -= sg_bytes;
670		remaining -= sg_bytes;
671
672		if ((skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN) &&
673		    (tlen))
674			continue;
675
676		/*
677		 * Send sequence with transfer sequence initiative in case
678		 * this is last FCP frame of the sequence.
679		 */
680		if (remaining == 0)
681			f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
682
683		ep = fc_seq_exch(seq);
684		fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
685			       FC_TYPE_FCP, f_ctl, fh_parm_offset);
686
687		/*
688		 * send fragment using for a sequence.
689		 */
690		error = lport->tt.seq_send(lport, seq, fp);
691		if (error) {
692			WARN_ON(1);		/* send error should be rare */
693			return error;
694		}
695		fp = NULL;
696	}
697	fsp->xfer_len += seq_blen;	/* premature count? */
698	return 0;
699}
700
701/**
702 * fc_fcp_abts_resp() - Receive an ABTS response
703 * @fsp: The FCP packet that is being aborted
704 * @fp:	 The response frame
705 */
706static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
707{
708	int ba_done = 1;
709	struct fc_ba_rjt *brp;
710	struct fc_frame_header *fh;
711
712	fh = fc_frame_header_get(fp);
713	switch (fh->fh_r_ctl) {
714	case FC_RCTL_BA_ACC:
715		break;
716	case FC_RCTL_BA_RJT:
717		brp = fc_frame_payload_get(fp, sizeof(*brp));
718		if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
719			break;
720		/* fall thru */
721	default:
722		/*
723		 * we will let the command timeout
724		 * and scsi-ml recover in this case,
725		 * therefore cleared the ba_done flag.
726		 */
727		ba_done = 0;
728	}
729
730	if (ba_done) {
731		fsp->state |= FC_SRB_ABORTED;
732		fsp->state &= ~FC_SRB_ABORT_PENDING;
733
734		if (fsp->wait_for_comp)
735			complete(&fsp->tm_done);
736		else
737			fc_fcp_complete_locked(fsp);
738	}
739}
740
741/**
742 * fc_fcp_recv() - Receive an FCP frame
743 * @seq: The sequence the frame is on
744 * @fp:	 The received frame
745 * @arg: The related FCP packet
746 *
747 * Context: Called from Soft IRQ context. Can not be called
748 *	    holding the FCP packet list lock.
749 */
750static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
751{
752	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
753	struct fc_lport *lport = fsp->lp;
754	struct fc_frame_header *fh;
755	struct fcp_txrdy *dd;
756	u8 r_ctl;
757	int rc = 0;
758
759	if (IS_ERR(fp)) {
760		fc_fcp_error(fsp, fp);
761		return;
762	}
763
764	fh = fc_frame_header_get(fp);
765	r_ctl = fh->fh_r_ctl;
766
767	if (lport->state != LPORT_ST_READY)
768		goto out;
769	if (fc_fcp_lock_pkt(fsp))
770		goto out;
771
772	if (fh->fh_type == FC_TYPE_BLS) {
773		fc_fcp_abts_resp(fsp, fp);
774		goto unlock;
775	}
776
777	if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING))
778		goto unlock;
779
780	if (r_ctl == FC_RCTL_DD_DATA_DESC) {
781		/*
782		 * received XFER RDY from the target
783		 * need to send data to the target
784		 */
785		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
786		dd = fc_frame_payload_get(fp, sizeof(*dd));
787		WARN_ON(!dd);
788
789		rc = fc_fcp_send_data(fsp, seq,
790				      (size_t) ntohl(dd->ft_data_ro),
791				      (size_t) ntohl(dd->ft_burst_len));
792		if (!rc)
793			seq->rec_data = fsp->xfer_len;
794	} else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
795		/*
796		 * received a DATA frame
797		 * next we will copy the data to the system buffer
798		 */
799		WARN_ON(fr_len(fp) < sizeof(*fh));	/* len may be 0 */
800		fc_fcp_recv_data(fsp, fp);
801		seq->rec_data = fsp->xfer_contig_end;
802	} else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
803		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
804
805		fc_fcp_resp(fsp, fp);
806	} else {
807		FC_FCP_DBG(fsp, "unexpected frame.  r_ctl %x\n", r_ctl);
808	}
809unlock:
810	fc_fcp_unlock_pkt(fsp);
811out:
812	fc_frame_free(fp);
813}
814
815/**
816 * fc_fcp_resp() - Handler for FCP responses
817 * @fsp: The FCP packet the response is for
818 * @fp:	 The response frame
819 */
820static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
821{
822	struct fc_frame_header *fh;
823	struct fcp_resp *fc_rp;
824	struct fcp_resp_ext *rp_ex;
825	struct fcp_resp_rsp_info *fc_rp_info;
826	u32 plen;
827	u32 expected_len;
828	u32 respl = 0;
829	u32 snsl = 0;
830	u8 flags = 0;
831
832	plen = fr_len(fp);
833	fh = (struct fc_frame_header *)fr_hdr(fp);
834	if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
835		goto len_err;
836	plen -= sizeof(*fh);
837	fc_rp = (struct fcp_resp *)(fh + 1);
838	fsp->cdb_status = fc_rp->fr_status;
839	flags = fc_rp->fr_flags;
840	fsp->scsi_comp_flags = flags;
841	expected_len = fsp->data_len;
842
843	/* if ddp, update xfer len */
844	fc_fcp_ddp_done(fsp);
845
846	if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
847		rp_ex = (void *)(fc_rp + 1);
848		if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
849			if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
850				goto len_err;
851			fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
852			if (flags & FCP_RSP_LEN_VAL) {
853				respl = ntohl(rp_ex->fr_rsp_len);
854				if ((respl != FCP_RESP_RSP_INFO_LEN4) &&
855				    (respl != FCP_RESP_RSP_INFO_LEN8))
856					goto len_err;
857				if (fsp->wait_for_comp) {
858					/* Abuse cdb_status for rsp code */
859					fsp->cdb_status = fc_rp_info->rsp_code;
860					complete(&fsp->tm_done);
861					/*
862					 * tmfs will not have any scsi cmd so
863					 * exit here
864					 */
865					return;
866				}
867			}
868			if (flags & FCP_SNS_LEN_VAL) {
869				snsl = ntohl(rp_ex->fr_sns_len);
870				if (snsl > SCSI_SENSE_BUFFERSIZE)
871					snsl = SCSI_SENSE_BUFFERSIZE;
872				memcpy(fsp->cmd->sense_buffer,
873				       (char *)fc_rp_info + respl, snsl);
874			}
875		}
876		if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
877			if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
878				goto len_err;
879			if (flags & FCP_RESID_UNDER) {
880				fsp->scsi_resid = ntohl(rp_ex->fr_resid);
881				/*
882				 * The cmnd->underflow is the minimum number of
883				 * bytes that must be transferred for this
884				 * command.  Provided a sense condition is not
885				 * present, make sure the actual amount
886				 * transferred is at least the underflow value
887				 * or fail.
888				 */
889				if (!(flags & FCP_SNS_LEN_VAL) &&
890				    (fc_rp->fr_status == 0) &&
891				    (scsi_bufflen(fsp->cmd) -
892				     fsp->scsi_resid) < fsp->cmd->underflow)
893					goto err;
894				expected_len -= fsp->scsi_resid;
895			} else {
896				fsp->status_code = FC_ERROR;
897			}
898		}
899	}
900	fsp->state |= FC_SRB_RCV_STATUS;
901
902	/*
903	 * Check for missing or extra data frames.
904	 */
905	if (unlikely(fsp->cdb_status == SAM_STAT_GOOD &&
906		     fsp->xfer_len != expected_len)) {
907		if (fsp->xfer_len < expected_len) {
908			/*
909			 * Some data may be queued locally,
910			 * Wait a at least one jiffy to see if it is delivered.
911			 * If this expires without data, we may do SRR.
912			 */
913			fc_fcp_timer_set(fsp, 2);
914			return;
915		}
916		fsp->status_code = FC_DATA_OVRRUN;
917		FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx greater than expected, "
918			   "len %x, data len %x\n",
919			   fsp->rport->port_id,
920			   fsp->xfer_len, expected_len, fsp->data_len);
921	}
922	fc_fcp_complete_locked(fsp);
923	return;
924
925len_err:
926	FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
927		   "snsl %u\n", flags, fr_len(fp), respl, snsl);
928err:
929	fsp->status_code = FC_ERROR;
930	fc_fcp_complete_locked(fsp);
931}
932
933/**
934 * fc_fcp_complete_locked() - Complete processing of a fcp_pkt with the
935 *			      fcp_pkt lock held
936 * @fsp: The FCP packet to be completed
937 *
938 * This function may sleep if a timer is pending. The packet lock must be
939 * held, and the host lock must not be held.
940 */
941static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
942{
943	struct fc_lport *lport = fsp->lp;
944	struct fc_seq *seq;
945	struct fc_exch *ep;
946	u32 f_ctl;
947
948	if (fsp->state & FC_SRB_ABORT_PENDING)
949		return;
950
951	if (fsp->state & FC_SRB_ABORTED) {
952		if (!fsp->status_code)
953			fsp->status_code = FC_CMD_ABORTED;
954	} else {
955		/*
956		 * Test for transport underrun, independent of response
957		 * underrun status.
958		 */
959		if (fsp->cdb_status == SAM_STAT_GOOD &&
960		    fsp->xfer_len < fsp->data_len && !fsp->io_status &&
961		    (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
962		     fsp->xfer_len < fsp->data_len - fsp->scsi_resid))
963			fsp->status_code = FC_DATA_UNDRUN;
964	}
965
966	seq = fsp->seq_ptr;
967	if (seq) {
968		fsp->seq_ptr = NULL;
969		if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
970			struct fc_frame *conf_frame;
971			struct fc_seq *csp;
972
973			csp = lport->tt.seq_start_next(seq);
974			conf_frame = fc_fcp_frame_alloc(fsp->lp, 0);
975			if (conf_frame) {
976				f_ctl = FC_FC_SEQ_INIT;
977				f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
978				ep = fc_seq_exch(seq);
979				fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
980					       ep->did, ep->sid,
981					       FC_TYPE_FCP, f_ctl, 0);
982				lport->tt.seq_send(lport, csp, conf_frame);
983			}
984		}
985		lport->tt.exch_done(seq);
986	}
987	/*
988	 * Some resets driven by SCSI are not I/Os and do not have
989	 * SCSI commands associated with the requests. We should not
990	 * call I/O completion if we do not have a SCSI command.
991	 */
992	if (fsp->cmd)
993		fc_io_compl(fsp);
994}
995
996/**
997 * fc_fcp_cleanup_cmd() - Cancel the active exchange on a fcp_pkt
998 * @fsp:   The FCP packet whose exchanges should be canceled
999 * @error: The reason for the cancellation
1000 */
1001static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
1002{
1003	struct fc_lport *lport = fsp->lp;
1004
1005	if (fsp->seq_ptr) {
1006		lport->tt.exch_done(fsp->seq_ptr);
1007		fsp->seq_ptr = NULL;
1008	}
1009	fsp->status_code = error;
1010}
1011
1012/**
1013 * fc_fcp_cleanup_each_cmd() - Cancel all exchanges on a local port
1014 * @lport: The local port whose exchanges should be canceled
1015 * @id:	   The target's ID
1016 * @lun:   The LUN
1017 * @error: The reason for cancellation
1018 *
1019 * If lun or id is -1, they are ignored.
1020 */
1021static void fc_fcp_cleanup_each_cmd(struct fc_lport *lport, unsigned int id,
1022				    unsigned int lun, int error)
1023{
1024	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1025	struct fc_fcp_pkt *fsp;
1026	struct scsi_cmnd *sc_cmd;
1027	unsigned long flags;
1028
1029	spin_lock_irqsave(&si->scsi_queue_lock, flags);
1030restart:
1031	list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
1032		sc_cmd = fsp->cmd;
1033		if (id != -1 && scmd_id(sc_cmd) != id)
1034			continue;
1035
1036		if (lun != -1 && sc_cmd->device->lun != lun)
1037			continue;
1038
1039		fc_fcp_pkt_hold(fsp);
1040		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1041
1042		spin_lock_bh(&fsp->scsi_pkt_lock);
1043		if (!(fsp->state & FC_SRB_COMPL)) {
1044			fsp->state |= FC_SRB_COMPL;
1045			/*
1046			 * TODO: dropping scsi_pkt_lock and then reacquiring
1047			 * again around fc_fcp_cleanup_cmd() is required,
1048			 * since fc_fcp_cleanup_cmd() calls into
1049			 * fc_seq_set_resp() and that func preempts cpu using
1050			 * schedule. May be schedule and related code should be
1051			 * removed instead of unlocking here to avoid scheduling
1052			 * while atomic bug.
1053			 */
1054			spin_unlock_bh(&fsp->scsi_pkt_lock);
1055
1056			fc_fcp_cleanup_cmd(fsp, error);
1057
1058			spin_lock_bh(&fsp->scsi_pkt_lock);
1059			fc_io_compl(fsp);
1060		}
1061		spin_unlock_bh(&fsp->scsi_pkt_lock);
1062
1063		fc_fcp_pkt_release(fsp);
1064		spin_lock_irqsave(&si->scsi_queue_lock, flags);
1065		/*
1066		 * while we dropped the lock multiple pkts could
1067		 * have been released, so we have to start over.
1068		 */
1069		goto restart;
1070	}
1071	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1072}
1073
1074/**
1075 * fc_fcp_abort_io() - Abort all FCP-SCSI exchanges on a local port
1076 * @lport: The local port whose exchanges are to be aborted
1077 */
1078static void fc_fcp_abort_io(struct fc_lport *lport)
1079{
1080	fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_HRD_ERROR);
1081}
1082
1083/**
1084 * fc_fcp_pkt_send() - Send a fcp_pkt
1085 * @lport: The local port to send the FCP packet on
1086 * @fsp:   The FCP packet to send
1087 *
1088 * Return:  Zero for success and -1 for failure
1089 * Locks:   Called without locks held
1090 */
1091static int fc_fcp_pkt_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp)
1092{
1093	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1094	unsigned long flags;
1095	int rc;
1096
1097	fsp->cmd->SCp.ptr = (char *)fsp;
1098	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1099	fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
1100
1101	int_to_scsilun(fsp->cmd->device->lun, &fsp->cdb_cmd.fc_lun);
1102	memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
1103
1104	spin_lock_irqsave(&si->scsi_queue_lock, flags);
1105	list_add_tail(&fsp->list, &si->scsi_pkt_queue);
1106	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1107	rc = lport->tt.fcp_cmd_send(lport, fsp, fc_fcp_recv);
1108	if (unlikely(rc)) {
1109		spin_lock_irqsave(&si->scsi_queue_lock, flags);
1110		fsp->cmd->SCp.ptr = NULL;
1111		list_del(&fsp->list);
1112		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1113	}
1114
1115	return rc;
1116}
1117
1118/**
1119 * get_fsp_rec_tov() - Helper function to get REC_TOV
1120 * @fsp: the FCP packet
1121 *
1122 * Returns rec tov in jiffies as rpriv->e_d_tov + 1 second
1123 */
1124static inline unsigned int get_fsp_rec_tov(struct fc_fcp_pkt *fsp)
1125{
1126	struct fc_rport_libfc_priv *rpriv = fsp->rport->dd_data;
1127
1128	return msecs_to_jiffies(rpriv->e_d_tov) + HZ;
1129}
1130
1131/**
1132 * fc_fcp_cmd_send() - Send a FCP command
1133 * @lport: The local port to send the command on
1134 * @fsp:   The FCP packet the command is on
1135 * @resp:  The handler for the response
1136 */
1137static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1138			   void (*resp)(struct fc_seq *,
1139					struct fc_frame *fp,
1140					void *arg))
1141{
1142	struct fc_frame *fp;
1143	struct fc_seq *seq;
1144	struct fc_rport *rport;
1145	struct fc_rport_libfc_priv *rpriv;
1146	const size_t len = sizeof(fsp->cdb_cmd);
1147	int rc = 0;
1148
1149	if (fc_fcp_lock_pkt(fsp))
1150		return 0;
1151
1152	fp = fc_fcp_frame_alloc(lport, sizeof(fsp->cdb_cmd));
1153	if (!fp) {
1154		rc = -1;
1155		goto unlock;
1156	}
1157
1158	memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
1159	fr_fsp(fp) = fsp;
1160	rport = fsp->rport;
1161	fsp->max_payload = rport->maxframe_size;
1162	rpriv = rport->dd_data;
1163
1164	fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
1165		       rpriv->local_port->port_id, FC_TYPE_FCP,
1166		       FC_FCTL_REQ, 0);
1167
1168	seq = lport->tt.exch_seq_send(lport, fp, resp, fc_fcp_pkt_destroy,
1169				      fsp, 0);
1170	if (!seq) {
1171		rc = -1;
1172		goto unlock;
1173	}
1174	fsp->seq_ptr = seq;
1175	fc_fcp_pkt_hold(fsp);	/* hold for fc_fcp_pkt_destroy */
1176
1177	setup_timer(&fsp->timer, fc_fcp_timeout, (unsigned long)fsp);
1178	if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1179		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1180
1181unlock:
1182	fc_fcp_unlock_pkt(fsp);
1183	return rc;
1184}
1185
1186/**
1187 * fc_fcp_error() - Handler for FCP layer errors
1188 * @fsp: The FCP packet the error is on
1189 * @fp:	 The frame that has errored
1190 */
1191static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1192{
1193	int error = PTR_ERR(fp);
1194
1195	if (fc_fcp_lock_pkt(fsp))
1196		return;
1197
1198	if (error == -FC_EX_CLOSED) {
1199		fc_fcp_retry_cmd(fsp);
1200		goto unlock;
1201	}
1202
1203	/*
1204	 * clear abort pending, because the lower layer
1205	 * decided to force completion.
1206	 */
1207	fsp->state &= ~FC_SRB_ABORT_PENDING;
1208	fsp->status_code = FC_CMD_PLOGO;
1209	fc_fcp_complete_locked(fsp);
1210unlock:
1211	fc_fcp_unlock_pkt(fsp);
1212}
1213
1214/**
1215 * fc_fcp_pkt_abort() - Abort a fcp_pkt
1216 * @fsp:   The FCP packet to abort on
1217 *
1218 * Called to send an abort and then wait for abort completion
1219 */
1220static int fc_fcp_pkt_abort(struct fc_fcp_pkt *fsp)
1221{
1222	int rc = FAILED;
1223	unsigned long ticks_left;
1224
1225	if (fc_fcp_send_abort(fsp))
1226		return FAILED;
1227
1228	init_completion(&fsp->tm_done);
1229	fsp->wait_for_comp = 1;
1230
1231	spin_unlock_bh(&fsp->scsi_pkt_lock);
1232	ticks_left = wait_for_completion_timeout(&fsp->tm_done,
1233							FC_SCSI_TM_TOV);
1234	spin_lock_bh(&fsp->scsi_pkt_lock);
1235	fsp->wait_for_comp = 0;
1236
1237	if (!ticks_left) {
1238		FC_FCP_DBG(fsp, "target abort cmd  failed\n");
1239	} else if (fsp->state & FC_SRB_ABORTED) {
1240		FC_FCP_DBG(fsp, "target abort cmd  passed\n");
1241		rc = SUCCESS;
1242		fc_fcp_complete_locked(fsp);
1243	}
1244
1245	return rc;
1246}
1247
1248/**
1249 * fc_lun_reset_send() - Send LUN reset command
1250 * @data: The FCP packet that identifies the LUN to be reset
1251 */
1252static void fc_lun_reset_send(unsigned long data)
1253{
1254	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1255	struct fc_lport *lport = fsp->lp;
1256
1257	if (lport->tt.fcp_cmd_send(lport, fsp, fc_tm_done)) {
1258		if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
1259			return;
1260		if (fc_fcp_lock_pkt(fsp))
1261			return;
1262		setup_timer(&fsp->timer, fc_lun_reset_send, (unsigned long)fsp);
1263		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1264		fc_fcp_unlock_pkt(fsp);
1265	}
1266}
1267
1268/**
1269 * fc_lun_reset() - Send a LUN RESET command to a device
1270 *		    and wait for the reply
1271 * @lport: The local port to sent the command on
1272 * @fsp:   The FCP packet that identifies the LUN to be reset
1273 * @id:	   The SCSI command ID
1274 * @lun:   The LUN ID to be reset
1275 */
1276static int fc_lun_reset(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1277			unsigned int id, unsigned int lun)
1278{
1279	int rc;
1280
1281	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1282	fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
1283	int_to_scsilun(lun, &fsp->cdb_cmd.fc_lun);
1284
1285	fsp->wait_for_comp = 1;
1286	init_completion(&fsp->tm_done);
1287
1288	fc_lun_reset_send((unsigned long)fsp);
1289
1290	/*
1291	 * wait for completion of reset
1292	 * after that make sure all commands are terminated
1293	 */
1294	rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1295
1296	spin_lock_bh(&fsp->scsi_pkt_lock);
1297	fsp->state |= FC_SRB_COMPL;
1298	spin_unlock_bh(&fsp->scsi_pkt_lock);
1299
1300	del_timer_sync(&fsp->timer);
1301
1302	spin_lock_bh(&fsp->scsi_pkt_lock);
1303	if (fsp->seq_ptr) {
1304		lport->tt.exch_done(fsp->seq_ptr);
1305		fsp->seq_ptr = NULL;
1306	}
1307	fsp->wait_for_comp = 0;
1308	spin_unlock_bh(&fsp->scsi_pkt_lock);
1309
1310	if (!rc) {
1311		FC_SCSI_DBG(lport, "lun reset failed\n");
1312		return FAILED;
1313	}
1314
1315	/* cdb_status holds the tmf's rsp code */
1316	if (fsp->cdb_status != FCP_TMF_CMPL)
1317		return FAILED;
1318
1319	FC_SCSI_DBG(lport, "lun reset to lun %u completed\n", lun);
1320	fc_fcp_cleanup_each_cmd(lport, id, lun, FC_CMD_ABORTED);
1321	return SUCCESS;
1322}
1323
1324/**
1325 * fc_tm_done() - Task Management response handler
1326 * @seq: The sequence that the response is on
1327 * @fp:	 The response frame
1328 * @arg: The FCP packet the response is for
1329 */
1330static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1331{
1332	struct fc_fcp_pkt *fsp = arg;
1333	struct fc_frame_header *fh;
1334
1335	if (IS_ERR(fp)) {
1336		/*
1337		 * If there is an error just let it timeout or wait
1338		 * for TMF to be aborted if it timedout.
1339		 *
1340		 * scsi-eh will escalate for when either happens.
1341		 */
1342		return;
1343	}
1344
1345	if (fc_fcp_lock_pkt(fsp))
1346		goto out;
1347
1348	/*
1349	 * raced with eh timeout handler.
1350	 */
1351	if (!fsp->seq_ptr || !fsp->wait_for_comp)
1352		goto out_unlock;
1353
1354	fh = fc_frame_header_get(fp);
1355	if (fh->fh_type != FC_TYPE_BLS)
1356		fc_fcp_resp(fsp, fp);
1357	fsp->seq_ptr = NULL;
1358	fsp->lp->tt.exch_done(seq);
1359out_unlock:
1360	fc_fcp_unlock_pkt(fsp);
1361out:
1362	fc_frame_free(fp);
1363}
1364
1365/**
1366 * fc_fcp_cleanup() - Cleanup all FCP exchanges on a local port
1367 * @lport: The local port to be cleaned up
1368 */
1369static void fc_fcp_cleanup(struct fc_lport *lport)
1370{
1371	fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_ERROR);
1372}
1373
1374/**
1375 * fc_fcp_timeout() - Handler for fcp_pkt timeouts
1376 * @data: The FCP packet that has timed out
1377 *
1378 * If REC is supported then just issue it and return. The REC exchange will
1379 * complete or time out and recovery can continue at that point. Otherwise,
1380 * if the response has been received without all the data it has been
1381 * ER_TIMEOUT since the response was received. If the response has not been
1382 * received we see if data was received recently. If it has been then we
1383 * continue waiting, otherwise, we abort the command.
1384 */
1385static void fc_fcp_timeout(unsigned long data)
1386{
1387	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1388	struct fc_rport *rport = fsp->rport;
1389	struct fc_rport_libfc_priv *rpriv = rport->dd_data;
1390
1391	if (fc_fcp_lock_pkt(fsp))
1392		return;
1393
1394	if (fsp->cdb_cmd.fc_tm_flags)
1395		goto unlock;
1396
1397	fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
1398
1399	if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1400		fc_fcp_rec(fsp);
1401	else if (fsp->state & FC_SRB_RCV_STATUS)
1402		fc_fcp_complete_locked(fsp);
1403	else
1404		fc_fcp_recovery(fsp, FC_TIMED_OUT);
1405	fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
1406unlock:
1407	fc_fcp_unlock_pkt(fsp);
1408}
1409
1410/**
1411 * fc_fcp_rec() - Send a REC ELS request
1412 * @fsp: The FCP packet to send the REC request on
1413 */
1414static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
1415{
1416	struct fc_lport *lport;
1417	struct fc_frame *fp;
1418	struct fc_rport *rport;
1419	struct fc_rport_libfc_priv *rpriv;
1420
1421	lport = fsp->lp;
1422	rport = fsp->rport;
1423	rpriv = rport->dd_data;
1424	if (!fsp->seq_ptr || rpriv->rp_state != RPORT_ST_READY) {
1425		fsp->status_code = FC_HRD_ERROR;
1426		fsp->io_status = 0;
1427		fc_fcp_complete_locked(fsp);
1428		return;
1429	}
1430
1431	fp = fc_fcp_frame_alloc(lport, sizeof(struct fc_els_rec));
1432	if (!fp)
1433		goto retry;
1434
1435	fr_seq(fp) = fsp->seq_ptr;
1436	fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
1437		       rpriv->local_port->port_id, FC_TYPE_ELS,
1438		       FC_FCTL_REQ, 0);
1439	if (lport->tt.elsct_send(lport, rport->port_id, fp, ELS_REC,
1440				 fc_fcp_rec_resp, fsp,
1441				 2 * lport->r_a_tov)) {
1442		fc_fcp_pkt_hold(fsp);		/* hold while REC outstanding */
1443		return;
1444	}
1445retry:
1446	if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1447		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1448	else
1449		fc_fcp_recovery(fsp, FC_TIMED_OUT);
1450}
1451
1452/**
1453 * fc_fcp_rec_resp() - Handler for REC ELS responses
1454 * @seq: The sequence the response is on
1455 * @fp:	 The response frame
1456 * @arg: The FCP packet the response is on
1457 *
1458 * If the response is a reject then the scsi layer will handle
1459 * the timeout. If the response is a LS_ACC then if the I/O was not completed
1460 * set the timeout and return. If the I/O was completed then complete the
1461 * exchange and tell the SCSI layer.
1462 */
1463static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1464{
1465	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
1466	struct fc_els_rec_acc *recp;
1467	struct fc_els_ls_rjt *rjt;
1468	u32 e_stat;
1469	u8 opcode;
1470	u32 offset;
1471	enum dma_data_direction data_dir;
1472	enum fc_rctl r_ctl;
1473	struct fc_rport_libfc_priv *rpriv;
1474
1475	if (IS_ERR(fp)) {
1476		fc_fcp_rec_error(fsp, fp);
1477		return;
1478	}
1479
1480	if (fc_fcp_lock_pkt(fsp))
1481		goto out;
1482
1483	fsp->recov_retry = 0;
1484	opcode = fc_frame_payload_op(fp);
1485	if (opcode == ELS_LS_RJT) {
1486		rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1487		switch (rjt->er_reason) {
1488		default:
1489			FC_FCP_DBG(fsp, "device %x unexpected REC reject "
1490				   "reason %d expl %d\n",
1491				   fsp->rport->port_id, rjt->er_reason,
1492				   rjt->er_explan);
1493			/* fall through */
1494		case ELS_RJT_UNSUP:
1495			FC_FCP_DBG(fsp, "device does not support REC\n");
1496			rpriv = fsp->rport->dd_data;
1497			/*
1498			 * if we do not spport RECs or got some bogus
1499			 * reason then resetup timer so we check for
1500			 * making progress.
1501			 */
1502			rpriv->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
1503			break;
1504		case ELS_RJT_LOGIC:
1505		case ELS_RJT_UNAB:
1506			/*
1507			 * If no data transfer, the command frame got dropped
1508			 * so we just retry.  If data was transferred, we
1509			 * lost the response but the target has no record,
1510			 * so we abort and retry.
1511			 */
1512			if (rjt->er_explan == ELS_EXPL_OXID_RXID &&
1513			    fsp->xfer_len == 0) {
1514				fc_fcp_retry_cmd(fsp);
1515				break;
1516			}
1517			fc_fcp_recovery(fsp, FC_ERROR);
1518			break;
1519		}
1520	} else if (opcode == ELS_LS_ACC) {
1521		if (fsp->state & FC_SRB_ABORTED)
1522			goto unlock_out;
1523
1524		data_dir = fsp->cmd->sc_data_direction;
1525		recp = fc_frame_payload_get(fp, sizeof(*recp));
1526		offset = ntohl(recp->reca_fc4value);
1527		e_stat = ntohl(recp->reca_e_stat);
1528
1529		if (e_stat & ESB_ST_COMPLETE) {
1530
1531			/*
1532			 * The exchange is complete.
1533			 *
1534			 * For output, we must've lost the response.
1535			 * For input, all data must've been sent.
1536			 * We lost may have lost the response
1537			 * (and a confirmation was requested) and maybe
1538			 * some data.
1539			 *
1540			 * If all data received, send SRR
1541			 * asking for response.	 If partial data received,
1542			 * or gaps, SRR requests data at start of gap.
1543			 * Recovery via SRR relies on in-order-delivery.
1544			 */
1545			if (data_dir == DMA_TO_DEVICE) {
1546				r_ctl = FC_RCTL_DD_CMD_STATUS;
1547			} else if (fsp->xfer_contig_end == offset) {
1548				r_ctl = FC_RCTL_DD_CMD_STATUS;
1549			} else {
1550				offset = fsp->xfer_contig_end;
1551				r_ctl = FC_RCTL_DD_SOL_DATA;
1552			}
1553			fc_fcp_srr(fsp, r_ctl, offset);
1554		} else if (e_stat & ESB_ST_SEQ_INIT) {
1555			/*
1556			 * The remote port has the initiative, so just
1557			 * keep waiting for it to complete.
1558			 */
1559			fc_fcp_timer_set(fsp,  get_fsp_rec_tov(fsp));
1560		} else {
1561
1562			/*
1563			 * The exchange is incomplete, we have seq. initiative.
1564			 * Lost response with requested confirmation,
1565			 * lost confirmation, lost transfer ready or
1566			 * lost write data.
1567			 *
1568			 * For output, if not all data was received, ask
1569			 * for transfer ready to be repeated.
1570			 *
1571			 * If we received or sent all the data, send SRR to
1572			 * request response.
1573			 *
1574			 * If we lost a response, we may have lost some read
1575			 * data as well.
1576			 */
1577			r_ctl = FC_RCTL_DD_SOL_DATA;
1578			if (data_dir == DMA_TO_DEVICE) {
1579				r_ctl = FC_RCTL_DD_CMD_STATUS;
1580				if (offset < fsp->data_len)
1581					r_ctl = FC_RCTL_DD_DATA_DESC;
1582			} else if (offset == fsp->xfer_contig_end) {
1583				r_ctl = FC_RCTL_DD_CMD_STATUS;
1584			} else if (fsp->xfer_contig_end < offset) {
1585				offset = fsp->xfer_contig_end;
1586			}
1587			fc_fcp_srr(fsp, r_ctl, offset);
1588		}
1589	}
1590unlock_out:
1591	fc_fcp_unlock_pkt(fsp);
1592out:
1593	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
1594	fc_frame_free(fp);
1595}
1596
1597/**
1598 * fc_fcp_rec_error() - Handler for REC errors
1599 * @fsp: The FCP packet the error is on
1600 * @fp:	 The REC frame
1601 */
1602static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1603{
1604	int error = PTR_ERR(fp);
1605
1606	if (fc_fcp_lock_pkt(fsp))
1607		goto out;
1608
1609	switch (error) {
1610	case -FC_EX_CLOSED:
1611		fc_fcp_retry_cmd(fsp);
1612		break;
1613
1614	default:
1615		FC_FCP_DBG(fsp, "REC %p fid %6.6x error unexpected error %d\n",
1616			   fsp, fsp->rport->port_id, error);
1617		fsp->status_code = FC_CMD_PLOGO;
1618		/* fall through */
1619
1620	case -FC_EX_TIMEOUT:
1621		/*
1622		 * Assume REC or LS_ACC was lost.
1623		 * The exchange manager will have aborted REC, so retry.
1624		 */
1625		FC_FCP_DBG(fsp, "REC fid %6.6x error error %d retry %d/%d\n",
1626			   fsp->rport->port_id, error, fsp->recov_retry,
1627			   FC_MAX_RECOV_RETRY);
1628		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1629			fc_fcp_rec(fsp);
1630		else
1631			fc_fcp_recovery(fsp, FC_ERROR);
1632		break;
1633	}
1634	fc_fcp_unlock_pkt(fsp);
1635out:
1636	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
1637}
1638
1639/**
1640 * fc_fcp_recovery() - Handler for fcp_pkt recovery
1641 * @fsp: The FCP pkt that needs to be aborted
1642 */
1643static void fc_fcp_recovery(struct fc_fcp_pkt *fsp, u8 code)
1644{
1645	fsp->status_code = code;
1646	fsp->cdb_status = 0;
1647	fsp->io_status = 0;
1648	/*
1649	 * if this fails then we let the scsi command timer fire and
1650	 * scsi-ml escalate.
1651	 */
1652	fc_fcp_send_abort(fsp);
1653}
1654
1655/**
1656 * fc_fcp_srr() - Send a SRR request (Sequence Retransmission Request)
1657 * @fsp:   The FCP packet the SRR is to be sent on
1658 * @r_ctl: The R_CTL field for the SRR request
1659 * This is called after receiving status but insufficient data, or
1660 * when expecting status but the request has timed out.
1661 */
1662static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
1663{
1664	struct fc_lport *lport = fsp->lp;
1665	struct fc_rport *rport;
1666	struct fc_rport_libfc_priv *rpriv;
1667	struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1668	struct fc_seq *seq;
1669	struct fcp_srr *srr;
1670	struct fc_frame *fp;
1671	unsigned int rec_tov;
1672
1673	rport = fsp->rport;
1674	rpriv = rport->dd_data;
1675
1676	if (!(rpriv->flags & FC_RP_FLAGS_RETRY) ||
1677	    rpriv->rp_state != RPORT_ST_READY)
1678		goto retry;			/* shouldn't happen */
1679	fp = fc_fcp_frame_alloc(lport, sizeof(*srr));
1680	if (!fp)
1681		goto retry;
1682
1683	srr = fc_frame_payload_get(fp, sizeof(*srr));
1684	memset(srr, 0, sizeof(*srr));
1685	srr->srr_op = ELS_SRR;
1686	srr->srr_ox_id = htons(ep->oxid);
1687	srr->srr_rx_id = htons(ep->rxid);
1688	srr->srr_r_ctl = r_ctl;
1689	srr->srr_rel_off = htonl(offset);
1690
1691	fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
1692		       rpriv->local_port->port_id, FC_TYPE_FCP,
1693		       FC_FCTL_REQ, 0);
1694
1695	rec_tov = get_fsp_rec_tov(fsp);
1696	seq = lport->tt.exch_seq_send(lport, fp, fc_fcp_srr_resp,
1697				      fc_fcp_pkt_destroy,
1698				      fsp, jiffies_to_msecs(rec_tov));
1699	if (!seq)
1700		goto retry;
1701
1702	fsp->recov_seq = seq;
1703	fsp->xfer_len = offset;
1704	fsp->xfer_contig_end = offset;
1705	fsp->state &= ~FC_SRB_RCV_STATUS;
1706	fc_fcp_pkt_hold(fsp);		/* hold for outstanding SRR */
1707	return;
1708retry:
1709	fc_fcp_retry_cmd(fsp);
1710}
1711
1712/**
1713 * fc_fcp_srr_resp() - Handler for SRR response
1714 * @seq: The sequence the SRR is on
1715 * @fp:	 The SRR frame
1716 * @arg: The FCP packet the SRR is on
1717 */
1718static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1719{
1720	struct fc_fcp_pkt *fsp = arg;
1721	struct fc_frame_header *fh;
1722
1723	if (IS_ERR(fp)) {
1724		fc_fcp_srr_error(fsp, fp);
1725		return;
1726	}
1727
1728	if (fc_fcp_lock_pkt(fsp))
1729		goto out;
1730
1731	fh = fc_frame_header_get(fp);
1732	/*
1733	 * BUG? fc_fcp_srr_error calls exch_done which would release
1734	 * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
1735	 * then fc_exch_timeout would be sending an abort. The exch_done
1736	 * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
1737	 * an abort response though.
1738	 */
1739	if (fh->fh_type == FC_TYPE_BLS) {
1740		fc_fcp_unlock_pkt(fsp);
1741		return;
1742	}
1743
1744	switch (fc_frame_payload_op(fp)) {
1745	case ELS_LS_ACC:
1746		fsp->recov_retry = 0;
1747		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1748		break;
1749	case ELS_LS_RJT:
1750	default:
1751		fc_fcp_recovery(fsp, FC_ERROR);
1752		break;
1753	}
1754	fc_fcp_unlock_pkt(fsp);
1755out:
1756	fsp->lp->tt.exch_done(seq);
1757	fc_frame_free(fp);
1758}
1759
1760/**
1761 * fc_fcp_srr_error() - Handler for SRR errors
1762 * @fsp: The FCP packet that the SRR error is on
1763 * @fp:	 The SRR frame
1764 */
1765static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1766{
1767	if (fc_fcp_lock_pkt(fsp))
1768		goto out;
1769	switch (PTR_ERR(fp)) {
1770	case -FC_EX_TIMEOUT:
1771		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1772			fc_fcp_rec(fsp);
1773		else
1774			fc_fcp_recovery(fsp, FC_TIMED_OUT);
1775		break;
1776	case -FC_EX_CLOSED:			/* e.g., link failure */
1777		/* fall through */
1778	default:
1779		fc_fcp_retry_cmd(fsp);
1780		break;
1781	}
1782	fc_fcp_unlock_pkt(fsp);
1783out:
1784	fsp->lp->tt.exch_done(fsp->recov_seq);
1785}
1786
1787/**
1788 * fc_fcp_lport_queue_ready() - Determine if the lport and it's queue is ready
1789 * @lport: The local port to be checked
1790 */
1791static inline int fc_fcp_lport_queue_ready(struct fc_lport *lport)
1792{
1793	/* lock ? */
1794	return (lport->state == LPORT_ST_READY) &&
1795		lport->link_up && !lport->qfull;
1796}
1797
1798/**
1799 * fc_queuecommand() - The queuecommand function of the SCSI template
1800 * @shost: The Scsi_Host that the command was issued to
1801 * @cmd:   The scsi_cmnd to be executed
1802 *
1803 * This is the i/o strategy routine, called by the SCSI layer.
1804 */
1805int fc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *sc_cmd)
1806{
1807	struct fc_lport *lport = shost_priv(shost);
1808	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1809	struct fc_fcp_pkt *fsp;
1810	struct fc_rport_libfc_priv *rpriv;
1811	int rval;
1812	int rc = 0;
1813	struct fc_stats *stats;
1814
1815	rval = fc_remote_port_chkready(rport);
1816	if (rval) {
1817		sc_cmd->result = rval;
1818		sc_cmd->scsi_done(sc_cmd);
1819		return 0;
1820	}
1821
1822	if (!*(struct fc_remote_port **)rport->dd_data) {
1823		/*
1824		 * rport is transitioning from blocked/deleted to
1825		 * online
1826		 */
1827		sc_cmd->result = DID_IMM_RETRY << 16;
1828		sc_cmd->scsi_done(sc_cmd);
1829		goto out;
1830	}
1831
1832	rpriv = rport->dd_data;
1833
1834	if (!fc_fcp_lport_queue_ready(lport)) {
1835		if (lport->qfull)
1836			fc_fcp_can_queue_ramp_down(lport);
1837		rc = SCSI_MLQUEUE_HOST_BUSY;
1838		goto out;
1839	}
1840
1841	fsp = fc_fcp_pkt_alloc(lport, GFP_ATOMIC);
1842	if (fsp == NULL) {
1843		rc = SCSI_MLQUEUE_HOST_BUSY;
1844		goto out;
1845	}
1846
1847	/*
1848	 * build the libfc request pkt
1849	 */
1850	fsp->cmd = sc_cmd;	/* save the cmd */
1851	fsp->rport = rport;	/* set the remote port ptr */
1852
1853	/*
1854	 * set up the transfer length
1855	 */
1856	fsp->data_len = scsi_bufflen(sc_cmd);
1857	fsp->xfer_len = 0;
1858
1859	/*
1860	 * setup the data direction
1861	 */
1862	stats = per_cpu_ptr(lport->stats, get_cpu());
1863	if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
1864		fsp->req_flags = FC_SRB_READ;
1865		stats->InputRequests++;
1866		stats->InputBytes += fsp->data_len;
1867	} else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
1868		fsp->req_flags = FC_SRB_WRITE;
1869		stats->OutputRequests++;
1870		stats->OutputBytes += fsp->data_len;
1871	} else {
1872		fsp->req_flags = 0;
1873		stats->ControlRequests++;
1874	}
1875	put_cpu();
1876
1877	/*
1878	 * send it to the lower layer
1879	 * if we get -1 return then put the request in the pending
1880	 * queue.
1881	 */
1882	rval = fc_fcp_pkt_send(lport, fsp);
1883	if (rval != 0) {
1884		fsp->state = FC_SRB_FREE;
1885		fc_fcp_pkt_release(fsp);
1886		rc = SCSI_MLQUEUE_HOST_BUSY;
1887	}
1888out:
1889	return rc;
1890}
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	int rval;
2042
2043	rval = fc_block_scsi_eh(sc_cmd);
2044	if (rval)
2045		return rval;
2046
2047	lport = shost_priv(sc_cmd->device->host);
2048	if (lport->state != LPORT_ST_READY)
2049		return rc;
2050	else if (!lport->link_up)
2051		return rc;
2052
2053	si = fc_get_scsi_internal(lport);
2054	spin_lock_irqsave(&si->scsi_queue_lock, flags);
2055	fsp = CMD_SP(sc_cmd);
2056	if (!fsp) {
2057		/* command completed while scsi eh was setting up */
2058		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2059		return SUCCESS;
2060	}
2061	/* grab a ref so the fsp and sc_cmd cannot be released from under us */
2062	fc_fcp_pkt_hold(fsp);
2063	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2064
2065	if (fc_fcp_lock_pkt(fsp)) {
2066		/* completed while we were waiting for timer to be deleted */
2067		rc = SUCCESS;
2068		goto release_pkt;
2069	}
2070
2071	rc = fc_fcp_pkt_abort(fsp);
2072	fc_fcp_unlock_pkt(fsp);
2073
2074release_pkt:
2075	fc_fcp_pkt_release(fsp);
2076	return rc;
2077}
2078EXPORT_SYMBOL(fc_eh_abort);
2079
2080/**
2081 * fc_eh_device_reset() - Reset a single LUN
2082 * @sc_cmd: The SCSI command which identifies the device whose
2083 *	    LUN is to be reset
2084 *
2085 * Set from SCSI host template.
2086 */
2087int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
2088{
2089	struct fc_lport *lport;
2090	struct fc_fcp_pkt *fsp;
2091	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
2092	int rc = FAILED;
2093	int rval;
2094
2095	rval = fc_block_scsi_eh(sc_cmd);
2096	if (rval)
2097		return rval;
2098
2099	lport = shost_priv(sc_cmd->device->host);
2100
2101	if (lport->state != LPORT_ST_READY)
2102		return rc;
2103
2104	FC_SCSI_DBG(lport, "Resetting rport (%6.6x)\n", rport->port_id);
2105
2106	fsp = fc_fcp_pkt_alloc(lport, GFP_NOIO);
2107	if (fsp == NULL) {
2108		printk(KERN_WARNING "libfc: could not allocate scsi_pkt\n");
2109		goto out;
2110	}
2111
2112	/*
2113	 * Build the libfc request pkt. Do not set the scsi cmnd, because
2114	 * the sc passed in is not setup for execution like when sent
2115	 * through the queuecommand callout.
2116	 */
2117	fsp->rport = rport;	/* set the remote port ptr */
2118
2119	/*
2120	 * flush outstanding commands
2121	 */
2122	rc = fc_lun_reset(lport, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
2123	fsp->state = FC_SRB_FREE;
2124	fc_fcp_pkt_release(fsp);
2125
2126out:
2127	return rc;
2128}
2129EXPORT_SYMBOL(fc_eh_device_reset);
2130
2131/**
2132 * fc_eh_host_reset() - Reset a Scsi_Host.
2133 * @sc_cmd: The SCSI command that identifies the SCSI host to be reset
2134 */
2135int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
2136{
2137	struct Scsi_Host *shost = sc_cmd->device->host;
2138	struct fc_lport *lport = shost_priv(shost);
2139	unsigned long wait_tmo;
2140
2141	FC_SCSI_DBG(lport, "Resetting host\n");
2142
2143	fc_block_scsi_eh(sc_cmd);
2144
2145	lport->tt.lport_reset(lport);
2146	wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
2147	while (!fc_fcp_lport_queue_ready(lport) && time_before(jiffies,
2148							       wait_tmo))
2149		msleep(1000);
2150
2151	if (fc_fcp_lport_queue_ready(lport)) {
2152		shost_printk(KERN_INFO, shost, "libfc: Host reset succeeded "
2153			     "on port (%6.6x)\n", lport->port_id);
2154		return SUCCESS;
2155	} else {
2156		shost_printk(KERN_INFO, shost, "libfc: Host reset failed, "
2157			     "port (%6.6x) is not ready.\n",
2158			     lport->port_id);
2159		return FAILED;
2160	}
2161}
2162EXPORT_SYMBOL(fc_eh_host_reset);
2163
2164/**
2165 * fc_slave_alloc() - Configure the queue depth of a Scsi_Host
2166 * @sdev: The SCSI device that identifies the SCSI host
2167 *
2168 * Configures queue depth based on host's cmd_per_len. If not set
2169 * then we use the libfc default.
2170 */
2171int fc_slave_alloc(struct scsi_device *sdev)
2172{
2173	struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
2174
2175	if (!rport || fc_remote_port_chkready(rport))
2176		return -ENXIO;
2177
2178	scsi_change_queue_depth(sdev, FC_FCP_DFLT_QUEUE_DEPTH);
2179	return 0;
2180}
2181EXPORT_SYMBOL(fc_slave_alloc);
2182
2183/**
2184 * fc_fcp_destory() - Tear down the FCP layer for a given local port
2185 * @lport: The local port that no longer needs the FCP layer
2186 */
2187void fc_fcp_destroy(struct fc_lport *lport)
2188{
2189	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
2190
2191	if (!list_empty(&si->scsi_pkt_queue))
2192		printk(KERN_ERR "libfc: Leaked SCSI packets when destroying "
2193		       "port (%6.6x)\n", lport->port_id);
2194
2195	mempool_destroy(si->scsi_pkt_pool);
2196	kfree(si);
2197	lport->scsi_priv = NULL;
2198}
2199EXPORT_SYMBOL(fc_fcp_destroy);
2200
2201int fc_setup_fcp(void)
2202{
2203	int rc = 0;
2204
2205	scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
2206					    sizeof(struct fc_fcp_pkt),
2207					    0, SLAB_HWCACHE_ALIGN, NULL);
2208	if (!scsi_pkt_cachep) {
2209		printk(KERN_ERR "libfc: Unable to allocate SRB cache, "
2210		       "module load failed!");
2211		rc = -ENOMEM;
2212	}
2213
2214	return rc;
2215}
2216
2217void fc_destroy_fcp(void)
2218{
2219	if (scsi_pkt_cachep)
2220		kmem_cache_destroy(scsi_pkt_cachep);
2221}
2222
2223/**
2224 * fc_fcp_init() - Initialize the FCP layer for a local port
2225 * @lport: The local port to initialize the exchange layer for
2226 */
2227int fc_fcp_init(struct fc_lport *lport)
2228{
2229	int rc;
2230	struct fc_fcp_internal *si;
2231
2232	if (!lport->tt.fcp_cmd_send)
2233		lport->tt.fcp_cmd_send = fc_fcp_cmd_send;
2234
2235	if (!lport->tt.fcp_cleanup)
2236		lport->tt.fcp_cleanup = fc_fcp_cleanup;
2237
2238	if (!lport->tt.fcp_abort_io)
2239		lport->tt.fcp_abort_io = fc_fcp_abort_io;
2240
2241	si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
2242	if (!si)
2243		return -ENOMEM;
2244	lport->scsi_priv = si;
2245	si->max_can_queue = lport->host->can_queue;
2246	INIT_LIST_HEAD(&si->scsi_pkt_queue);
2247	spin_lock_init(&si->scsi_queue_lock);
2248
2249	si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
2250	if (!si->scsi_pkt_pool) {
2251		rc = -ENOMEM;
2252		goto free_internal;
2253	}
2254	return 0;
2255
2256free_internal:
2257	kfree(si);
2258	return rc;
2259}
2260EXPORT_SYMBOL(fc_fcp_init);
2261