1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright(c) 2007 Intel Corporation. All rights reserved.
4 * Copyright(c) 2008 Red Hat, Inc.  All rights reserved.
5 * Copyright(c) 2008 Mike Christie
6 *
7 * Maintained at www.Open-FCoE.org
8 */
9
10#include <linux/module.h>
11#include <linux/delay.h>
12#include <linux/kernel.h>
13#include <linux/types.h>
14#include <linux/spinlock.h>
15#include <linux/scatterlist.h>
16#include <linux/err.h>
17#include <linux/crc32.h>
18#include <linux/slab.h>
19
20#include <scsi/scsi_tcq.h>
21#include <scsi/scsi.h>
22#include <scsi/scsi_host.h>
23#include <scsi/scsi_device.h>
24#include <scsi/scsi_cmnd.h>
25
26#include <scsi/fc/fc_fc2.h>
27
28#include <scsi/libfc.h>
29#include <scsi/fc_encode.h>
30
31#include "fc_libfc.h"
32
33static struct kmem_cache *scsi_pkt_cachep;
34
35/* SRB state definitions */
36#define FC_SRB_FREE		0		/* cmd is free */
37#define FC_SRB_CMD_SENT		(1 << 0)	/* cmd has been sent */
38#define FC_SRB_RCV_STATUS	(1 << 1)	/* response has arrived */
39#define FC_SRB_ABORT_PENDING	(1 << 2)	/* cmd abort sent to device */
40#define FC_SRB_ABORTED		(1 << 3)	/* abort acknowledged */
41#define FC_SRB_DISCONTIG	(1 << 4)	/* non-sequential data recvd */
42#define FC_SRB_COMPL		(1 << 5)	/* fc_io_compl has been run */
43#define FC_SRB_FCP_PROCESSING_TMO (1 << 6)	/* timer function processing */
44
45#define FC_SRB_READ		(1 << 1)
46#define FC_SRB_WRITE		(1 << 0)
47
48/*
49 * The SCp.ptr should be tested and set under the scsi_pkt_queue lock
50 */
51#define CMD_SP(Cmnd)		    ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)
52#define CMD_ENTRY_STATUS(Cmnd)	    ((Cmnd)->SCp.have_data_in)
53#define CMD_COMPL_STATUS(Cmnd)	    ((Cmnd)->SCp.this_residual)
54#define CMD_SCSI_STATUS(Cmnd)	    ((Cmnd)->SCp.Status)
55#define CMD_RESID_LEN(Cmnd)	    ((Cmnd)->SCp.buffers_residual)
56
57/**
58 * struct fc_fcp_internal - FCP layer internal data
59 * @scsi_pkt_pool: Memory pool to draw FCP packets from
60 * @scsi_queue_lock: Protects the scsi_pkt_queue
61 * @scsi_pkt_queue: Current FCP packets
62 * @last_can_queue_ramp_down_time: ramp down time
63 * @last_can_queue_ramp_up_time: ramp up time
64 * @max_can_queue: max can_queue size
65 */
66struct fc_fcp_internal {
67	mempool_t		*scsi_pkt_pool;
68	spinlock_t		scsi_queue_lock;
69	struct list_head	scsi_pkt_queue;
70	unsigned long		last_can_queue_ramp_down_time;
71	unsigned long		last_can_queue_ramp_up_time;
72	int			max_can_queue;
73};
74
75#define fc_get_scsi_internal(x)	((struct fc_fcp_internal *)(x)->scsi_priv)
76
77/*
78 * function prototypes
79 * FC scsi I/O related functions
80 */
81static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
82static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
83static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
84static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
85static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
86static void fc_fcp_error(struct fc_fcp_pkt *, struct fc_frame *);
87static void fc_fcp_recovery(struct fc_fcp_pkt *, u8 code);
88static void fc_fcp_timeout(struct timer_list *);
89static void fc_fcp_rec(struct fc_fcp_pkt *);
90static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
91static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
92static void fc_io_compl(struct fc_fcp_pkt *);
93
94static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
95static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
96static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
97
98/*
99 * command status codes
100 */
101#define FC_COMPLETE		0
102#define FC_CMD_ABORTED		1
103#define FC_CMD_RESET		2
104#define FC_CMD_PLOGO		3
105#define FC_SNS_RCV		4
106#define FC_TRANS_ERR		5
107#define FC_DATA_OVRRUN		6
108#define FC_DATA_UNDRUN		7
109#define FC_ERROR		8
110#define FC_HRD_ERROR		9
111#define FC_CRC_ERROR		10
112#define FC_TIMED_OUT		11
113#define FC_TRANS_RESET		12
114
115/*
116 * Error recovery timeout values.
117 */
118#define FC_SCSI_TM_TOV		(10 * HZ)
119#define FC_HOST_RESET_TIMEOUT	(30 * HZ)
120#define FC_CAN_QUEUE_PERIOD	(60 * HZ)
121
122#define FC_MAX_ERROR_CNT	5
123#define FC_MAX_RECOV_RETRY	3
124
125#define FC_FCP_DFLT_QUEUE_DEPTH 32
126
127/**
128 * fc_fcp_pkt_alloc() - Allocate a fcp_pkt
129 * @lport: The local port that the FCP packet is for
130 * @gfp:   GFP flags for allocation
131 *
132 * Return value: fcp_pkt structure or null on allocation failure.
133 * Context:	 Can be called from process context, no lock is required.
134 */
135static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lport, gfp_t gfp)
136{
137	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
138	struct fc_fcp_pkt *fsp;
139
140	fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
141	if (fsp) {
142		memset(fsp, 0, sizeof(*fsp));
143		fsp->lp = lport;
144		fsp->xfer_ddp = FC_XID_UNKNOWN;
145		refcount_set(&fsp->ref_cnt, 1);
146		timer_setup(&fsp->timer, NULL, 0);
147		INIT_LIST_HEAD(&fsp->list);
148		spin_lock_init(&fsp->scsi_pkt_lock);
149	} else {
150		per_cpu_ptr(lport->stats, get_cpu())->FcpPktAllocFails++;
151		put_cpu();
152	}
153	return fsp;
154}
155
156/**
157 * fc_fcp_pkt_release() - Release hold on a fcp_pkt
158 * @fsp: The FCP packet to be released
159 *
160 * Context: Can be called from process or interrupt context,
161 *	    no lock is required.
162 */
163static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
164{
165	if (refcount_dec_and_test(&fsp->ref_cnt)) {
166		struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
167
168		mempool_free(fsp, si->scsi_pkt_pool);
169	}
170}
171
172/**
173 * fc_fcp_pkt_hold() - Hold a fcp_pkt
174 * @fsp: The FCP packet to be held
175 */
176static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
177{
178	refcount_inc(&fsp->ref_cnt);
179}
180
181/**
182 * fc_fcp_pkt_destroy() - Release hold on a fcp_pkt
183 * @seq: The sequence that the FCP packet is on (required by destructor API)
184 * @fsp: The FCP packet to be released
185 *
186 * This routine is called by a destructor callback in the fc_exch_seq_send()
187 * routine of the libfc Transport Template. The 'struct fc_seq' is a required
188 * argument even though it is not used by this routine.
189 *
190 * Context: No locking required.
191 */
192static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
193{
194	fc_fcp_pkt_release(fsp);
195}
196
197/**
198 * fc_fcp_lock_pkt() - Lock a fcp_pkt and increase its reference count
199 * @fsp: The FCP packet to be locked and incremented
200 *
201 * We should only return error if we return a command to SCSI-ml before
202 * getting a response. This can happen in cases where we send a abort, but
203 * do not wait for the response and the abort and command can be passing
204 * each other on the wire/network-layer.
205 *
206 * Note: this function locks the packet and gets a reference to allow
207 * callers to call the completion function while the lock is held and
208 * not have to worry about the packets refcount.
209 *
210 * TODO: Maybe we should just have callers grab/release the lock and
211 * have a function that they call to verify the fsp and grab a ref if
212 * needed.
213 */
214static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
215{
216	spin_lock_bh(&fsp->scsi_pkt_lock);
217	if (fsp->state & FC_SRB_COMPL) {
218		spin_unlock_bh(&fsp->scsi_pkt_lock);
219		return -EPERM;
220	}
221
222	fc_fcp_pkt_hold(fsp);
223	return 0;
224}
225
226/**
227 * fc_fcp_unlock_pkt() - Release a fcp_pkt's lock and decrement its
228 *			 reference count
229 * @fsp: The FCP packet to be unlocked and decremented
230 */
231static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
232{
233	spin_unlock_bh(&fsp->scsi_pkt_lock);
234	fc_fcp_pkt_release(fsp);
235}
236
237/**
238 * fc_fcp_timer_set() - Start a timer for a fcp_pkt
239 * @fsp:   The FCP packet to start a timer for
240 * @delay: The timeout period in jiffies
241 */
242static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
243{
244	if (!(fsp->state & FC_SRB_COMPL)) {
245		mod_timer(&fsp->timer, jiffies + delay);
246		fsp->timer_delay = delay;
247	}
248}
249
250static void fc_fcp_abort_done(struct fc_fcp_pkt *fsp)
251{
252	fsp->state |= FC_SRB_ABORTED;
253	fsp->state &= ~FC_SRB_ABORT_PENDING;
254
255	if (fsp->wait_for_comp)
256		complete(&fsp->tm_done);
257	else
258		fc_fcp_complete_locked(fsp);
259}
260
261/**
262 * fc_fcp_send_abort() - Send an abort for exchanges associated with a
263 *			 fcp_pkt
264 * @fsp: The FCP packet to abort exchanges on
265 */
266static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
267{
268	int rc;
269
270	if (!fsp->seq_ptr)
271		return -EINVAL;
272
273	if (fsp->state & FC_SRB_ABORT_PENDING) {
274		FC_FCP_DBG(fsp, "abort already pending\n");
275		return -EBUSY;
276	}
277
278	per_cpu_ptr(fsp->lp->stats, get_cpu())->FcpPktAborts++;
279	put_cpu();
280
281	fsp->state |= FC_SRB_ABORT_PENDING;
282	rc = fc_seq_exch_abort(fsp->seq_ptr, 0);
283	/*
284	 * fc_seq_exch_abort() might return -ENXIO if
285	 * the sequence is already completed
286	 */
287	if (rc == -ENXIO) {
288		fc_fcp_abort_done(fsp);
289		rc = 0;
290	}
291	return rc;
292}
293
294/**
295 * fc_fcp_retry_cmd() - Retry a fcp_pkt
296 * @fsp: The FCP packet to be retried
297 * @status_code: The FCP status code to set
298 *
299 * Sets the status code to be FC_ERROR and then calls
300 * fc_fcp_complete_locked() which in turn calls fc_io_compl().
301 * fc_io_compl() will notify the SCSI-ml that the I/O is done.
302 * The SCSI-ml will retry the command.
303 */
304static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp, int status_code)
305{
306	if (fsp->seq_ptr) {
307		fc_exch_done(fsp->seq_ptr);
308		fsp->seq_ptr = NULL;
309	}
310
311	fsp->state &= ~FC_SRB_ABORT_PENDING;
312	fsp->io_status = 0;
313	fsp->status_code = status_code;
314	fc_fcp_complete_locked(fsp);
315}
316
317/**
318 * fc_fcp_ddp_setup() - Calls a LLD's ddp_setup routine to set up DDP context
319 * @fsp: The FCP packet that will manage the DDP frames
320 * @xid: The XID that will be used for the DDP exchange
321 */
322void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
323{
324	struct fc_lport *lport;
325
326	lport = fsp->lp;
327	if ((fsp->req_flags & FC_SRB_READ) &&
328	    (lport->lro_enabled) && (lport->tt.ddp_setup)) {
329		if (lport->tt.ddp_setup(lport, xid, scsi_sglist(fsp->cmd),
330					scsi_sg_count(fsp->cmd)))
331			fsp->xfer_ddp = xid;
332	}
333}
334
335/**
336 * fc_fcp_ddp_done() - Calls a LLD's ddp_done routine to release any
337 *		       DDP related resources for a fcp_pkt
338 * @fsp: The FCP packet that DDP had been used on
339 */
340void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
341{
342	struct fc_lport *lport;
343
344	if (!fsp)
345		return;
346
347	if (fsp->xfer_ddp == FC_XID_UNKNOWN)
348		return;
349
350	lport = fsp->lp;
351	if (lport->tt.ddp_done) {
352		fsp->xfer_len = lport->tt.ddp_done(lport, fsp->xfer_ddp);
353		fsp->xfer_ddp = FC_XID_UNKNOWN;
354	}
355}
356
357/**
358 * fc_fcp_can_queue_ramp_up() - increases can_queue
359 * @lport: lport to ramp up can_queue
360 */
361static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
362{
363	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
364	unsigned long flags;
365	int can_queue;
366
367	spin_lock_irqsave(lport->host->host_lock, flags);
368
369	if (si->last_can_queue_ramp_up_time &&
370	    (time_before(jiffies, si->last_can_queue_ramp_up_time +
371			 FC_CAN_QUEUE_PERIOD)))
372		goto unlock;
373
374	if (time_before(jiffies, si->last_can_queue_ramp_down_time +
375			FC_CAN_QUEUE_PERIOD))
376		goto unlock;
377
378	si->last_can_queue_ramp_up_time = jiffies;
379
380	can_queue = lport->host->can_queue << 1;
381	if (can_queue >= si->max_can_queue) {
382		can_queue = si->max_can_queue;
383		si->last_can_queue_ramp_down_time = 0;
384	}
385	lport->host->can_queue = can_queue;
386	shost_printk(KERN_ERR, lport->host, "libfc: increased "
387		     "can_queue to %d.\n", can_queue);
388
389unlock:
390	spin_unlock_irqrestore(lport->host->host_lock, flags);
391}
392
393/**
394 * fc_fcp_can_queue_ramp_down() - reduces can_queue
395 * @lport: lport to reduce can_queue
396 *
397 * If we are getting memory allocation failures, then we may
398 * be trying to execute too many commands. We let the running
399 * commands complete or timeout, then try again with a reduced
400 * can_queue. Eventually we will hit the point where we run
401 * on all reserved structs.
402 */
403static bool fc_fcp_can_queue_ramp_down(struct fc_lport *lport)
404{
405	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
406	unsigned long flags;
407	int can_queue;
408	bool changed = false;
409
410	spin_lock_irqsave(lport->host->host_lock, flags);
411
412	if (si->last_can_queue_ramp_down_time &&
413	    (time_before(jiffies, si->last_can_queue_ramp_down_time +
414			 FC_CAN_QUEUE_PERIOD)))
415		goto unlock;
416
417	si->last_can_queue_ramp_down_time = jiffies;
418
419	can_queue = lport->host->can_queue;
420	can_queue >>= 1;
421	if (!can_queue)
422		can_queue = 1;
423	lport->host->can_queue = can_queue;
424	changed = true;
425
426unlock:
427	spin_unlock_irqrestore(lport->host->host_lock, flags);
428	return changed;
429}
430
431/*
432 * fc_fcp_frame_alloc() -  Allocates fc_frame structure and buffer.
433 * @lport:	fc lport struct
434 * @len:	payload length
435 *
436 * Allocates fc_frame structure and buffer but if fails to allocate
437 * then reduce can_queue.
438 */
439static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport,
440						  size_t len)
441{
442	struct fc_frame *fp;
443
444	fp = fc_frame_alloc(lport, len);
445	if (likely(fp))
446		return fp;
447
448	per_cpu_ptr(lport->stats, get_cpu())->FcpFrameAllocFails++;
449	put_cpu();
450	/* error case */
451	fc_fcp_can_queue_ramp_down(lport);
452	shost_printk(KERN_ERR, lport->host,
453		     "libfc: Could not allocate frame, "
454		     "reducing can_queue to %d.\n", lport->host->can_queue);
455	return NULL;
456}
457
458/**
459 * get_fsp_rec_tov() - Helper function to get REC_TOV
460 * @fsp: the FCP packet
461 *
462 * Returns rec tov in jiffies as rpriv->e_d_tov + 1 second
463 */
464static inline unsigned int get_fsp_rec_tov(struct fc_fcp_pkt *fsp)
465{
466	struct fc_rport_libfc_priv *rpriv = fsp->rport->dd_data;
467	unsigned int e_d_tov = FC_DEF_E_D_TOV;
468
469	if (rpriv && rpriv->e_d_tov > e_d_tov)
470		e_d_tov = rpriv->e_d_tov;
471	return msecs_to_jiffies(e_d_tov) + HZ;
472}
473
474/**
475 * fc_fcp_recv_data() - Handler for receiving SCSI-FCP data from a target
476 * @fsp: The FCP packet the data is on
477 * @fp:	 The data frame
478 */
479static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
480{
481	struct scsi_cmnd *sc = fsp->cmd;
482	struct fc_lport *lport = fsp->lp;
483	struct fc_stats *stats;
484	struct fc_frame_header *fh;
485	size_t start_offset;
486	size_t offset;
487	u32 crc;
488	u32 copy_len = 0;
489	size_t len;
490	void *buf;
491	struct scatterlist *sg;
492	u32 nents;
493	u8 host_bcode = FC_COMPLETE;
494
495	fh = fc_frame_header_get(fp);
496	offset = ntohl(fh->fh_parm_offset);
497	start_offset = offset;
498	len = fr_len(fp) - sizeof(*fh);
499	buf = fc_frame_payload_get(fp, 0);
500
501	/*
502	 * if this I/O is ddped then clear it and initiate recovery since data
503	 * frames are expected to be placed directly in that case.
504	 *
505	 * Indicate error to scsi-ml because something went wrong with the
506	 * ddp handling to get us here.
507	 */
508	if (fsp->xfer_ddp != FC_XID_UNKNOWN) {
509		fc_fcp_ddp_done(fsp);
510		FC_FCP_DBG(fsp, "DDP I/O in fc_fcp_recv_data set ERROR\n");
511		host_bcode = FC_ERROR;
512		goto err;
513	}
514	if (offset + len > fsp->data_len) {
515		/* this should never happen */
516		if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
517		    fc_frame_crc_check(fp))
518			goto crc_err;
519		FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
520			   "data_len %x\n", len, offset, fsp->data_len);
521
522		/* Data is corrupted indicate scsi-ml should retry */
523		host_bcode = FC_DATA_OVRRUN;
524		goto err;
525	}
526	if (offset != fsp->xfer_len)
527		fsp->state |= FC_SRB_DISCONTIG;
528
529	sg = scsi_sglist(sc);
530	nents = scsi_sg_count(sc);
531
532	if (!(fr_flags(fp) & FCPHF_CRC_UNCHECKED)) {
533		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
534						    &offset, NULL);
535	} else {
536		crc = crc32(~0, (u8 *) fh, sizeof(*fh));
537		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
538						    &offset, &crc);
539		buf = fc_frame_payload_get(fp, 0);
540		if (len % 4)
541			crc = crc32(crc, buf + len, 4 - (len % 4));
542
543		if (~crc != le32_to_cpu(fr_crc(fp))) {
544crc_err:
545			stats = per_cpu_ptr(lport->stats, get_cpu());
546			stats->ErrorFrames++;
547			/* per cpu count, not total count, but OK for limit */
548			if (stats->InvalidCRCCount++ < FC_MAX_ERROR_CNT)
549				printk(KERN_WARNING "libfc: CRC error on data "
550				       "frame for port (%6.6x)\n",
551				       lport->port_id);
552			put_cpu();
553			/*
554			 * Assume the frame is total garbage.
555			 * We may have copied it over the good part
556			 * of the buffer.
557			 * If so, we need to retry the entire operation.
558			 * Otherwise, ignore it.
559			 */
560			if (fsp->state & FC_SRB_DISCONTIG) {
561				host_bcode = FC_CRC_ERROR;
562				goto err;
563			}
564			return;
565		}
566	}
567
568	if (fsp->xfer_contig_end == start_offset)
569		fsp->xfer_contig_end += copy_len;
570	fsp->xfer_len += copy_len;
571
572	/*
573	 * In the very rare event that this data arrived after the response
574	 * and completes the transfer, call the completion handler.
575	 */
576	if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
577	    fsp->xfer_len == fsp->data_len - fsp->scsi_resid) {
578		FC_FCP_DBG( fsp, "complete out-of-order sequence\n" );
579		fc_fcp_complete_locked(fsp);
580	}
581	return;
582err:
583	fc_fcp_recovery(fsp, host_bcode);
584}
585
586/**
587 * fc_fcp_send_data() - Send SCSI data to a target
588 * @fsp:      The FCP packet the data is on
589 * @seq:      The sequence the data is to be sent on
590 * @offset:   The starting offset for this data request
591 * @seq_blen: The burst length for this data request
592 *
593 * Called after receiving a Transfer Ready data descriptor.
594 * If the LLD is capable of sequence offload then send down the
595 * seq_blen amount of data in single frame, otherwise send
596 * multiple frames of the maximum frame payload supported by
597 * the target port.
598 */
599static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
600			    size_t offset, size_t seq_blen)
601{
602	struct fc_exch *ep;
603	struct scsi_cmnd *sc;
604	struct scatterlist *sg;
605	struct fc_frame *fp = NULL;
606	struct fc_lport *lport = fsp->lp;
607	struct page *page;
608	size_t remaining;
609	size_t t_blen;
610	size_t tlen;
611	size_t sg_bytes;
612	size_t frame_offset, fh_parm_offset;
613	size_t off;
614	int error;
615	void *data = NULL;
616	void *page_addr;
617	int using_sg = lport->sg_supp;
618	u32 f_ctl;
619
620	WARN_ON(seq_blen <= 0);
621	if (unlikely(offset + seq_blen > fsp->data_len)) {
622		/* this should never happen */
623		FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
624			   "offset %zx\n", seq_blen, offset);
625		fc_fcp_send_abort(fsp);
626		return 0;
627	} else if (offset != fsp->xfer_len) {
628		/* Out of Order Data Request - no problem, but unexpected. */
629		FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
630			   "seq_blen %zx offset %zx\n", seq_blen, offset);
631	}
632
633	/*
634	 * if LLD is capable of seq_offload then set transport
635	 * burst length (t_blen) to seq_blen, otherwise set t_blen
636	 * to max FC frame payload previously set in fsp->max_payload.
637	 */
638	t_blen = fsp->max_payload;
639	if (lport->seq_offload) {
640		t_blen = min(seq_blen, (size_t)lport->lso_max);
641		FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
642			   fsp, seq_blen, lport->lso_max, t_blen);
643	}
644
645	if (t_blen > 512)
646		t_blen &= ~(512 - 1);	/* round down to block size */
647	sc = fsp->cmd;
648
649	remaining = seq_blen;
650	fh_parm_offset = frame_offset = offset;
651	tlen = 0;
652	seq = fc_seq_start_next(seq);
653	f_ctl = FC_FC_REL_OFF;
654	WARN_ON(!seq);
655
656	sg = scsi_sglist(sc);
657
658	while (remaining > 0 && sg) {
659		if (offset >= sg->length) {
660			offset -= sg->length;
661			sg = sg_next(sg);
662			continue;
663		}
664		if (!fp) {
665			tlen = min(t_blen, remaining);
666
667			/*
668			 * TODO.  Temporary workaround.	 fc_seq_send() can't
669			 * handle odd lengths in non-linear skbs.
670			 * This will be the final fragment only.
671			 */
672			if (tlen % 4)
673				using_sg = 0;
674			fp = fc_frame_alloc(lport, using_sg ? 0 : tlen);
675			if (!fp)
676				return -ENOMEM;
677
678			data = fc_frame_header_get(fp) + 1;
679			fh_parm_offset = frame_offset;
680			fr_max_payload(fp) = fsp->max_payload;
681		}
682
683		off = offset + sg->offset;
684		sg_bytes = min(tlen, sg->length - offset);
685		sg_bytes = min(sg_bytes,
686			       (size_t) (PAGE_SIZE - (off & ~PAGE_MASK)));
687		page = sg_page(sg) + (off >> PAGE_SHIFT);
688		if (using_sg) {
689			get_page(page);
690			skb_fill_page_desc(fp_skb(fp),
691					   skb_shinfo(fp_skb(fp))->nr_frags,
692					   page, off & ~PAGE_MASK, sg_bytes);
693			fp_skb(fp)->data_len += sg_bytes;
694			fr_len(fp) += sg_bytes;
695			fp_skb(fp)->truesize += PAGE_SIZE;
696		} else {
697			/*
698			 * The scatterlist item may be bigger than PAGE_SIZE,
699			 * but we must not cross pages inside the kmap.
700			 */
701			page_addr = kmap_atomic(page);
702			memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
703			       sg_bytes);
704			kunmap_atomic(page_addr);
705			data += sg_bytes;
706		}
707		offset += sg_bytes;
708		frame_offset += sg_bytes;
709		tlen -= sg_bytes;
710		remaining -= sg_bytes;
711
712		if ((skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN) &&
713		    (tlen))
714			continue;
715
716		/*
717		 * Send sequence with transfer sequence initiative in case
718		 * this is last FCP frame of the sequence.
719		 */
720		if (remaining == 0)
721			f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
722
723		ep = fc_seq_exch(seq);
724		fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
725			       FC_TYPE_FCP, f_ctl, fh_parm_offset);
726
727		/*
728		 * send fragment using for a sequence.
729		 */
730		error = fc_seq_send(lport, seq, fp);
731		if (error) {
732			WARN_ON(1);		/* send error should be rare */
733			return error;
734		}
735		fp = NULL;
736	}
737	fsp->xfer_len += seq_blen;	/* premature count? */
738	return 0;
739}
740
741/**
742 * fc_fcp_abts_resp() - Receive an ABTS response
743 * @fsp: The FCP packet that is being aborted
744 * @fp:	 The response frame
745 */
746static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
747{
748	int ba_done = 1;
749	struct fc_ba_rjt *brp;
750	struct fc_frame_header *fh;
751
752	fh = fc_frame_header_get(fp);
753	switch (fh->fh_r_ctl) {
754	case FC_RCTL_BA_ACC:
755		break;
756	case FC_RCTL_BA_RJT:
757		brp = fc_frame_payload_get(fp, sizeof(*brp));
758		if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
759			break;
760		fallthrough;
761	default:
762		/*
763		 * we will let the command timeout
764		 * and scsi-ml recover in this case,
765		 * therefore cleared the ba_done flag.
766		 */
767		ba_done = 0;
768	}
769
770	if (ba_done)
771		fc_fcp_abort_done(fsp);
772}
773
774/**
775 * fc_fcp_recv() - Receive an FCP frame
776 * @seq: The sequence the frame is on
777 * @fp:	 The received frame
778 * @arg: The related FCP packet
779 *
780 * Context: Called from Soft IRQ context. Can not be called
781 *	    holding the FCP packet list lock.
782 */
783static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
784{
785	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
786	struct fc_lport *lport = fsp->lp;
787	struct fc_frame_header *fh;
788	struct fcp_txrdy *dd;
789	u8 r_ctl;
790	int rc = 0;
791
792	if (IS_ERR(fp)) {
793		fc_fcp_error(fsp, fp);
794		return;
795	}
796
797	fh = fc_frame_header_get(fp);
798	r_ctl = fh->fh_r_ctl;
799
800	if (lport->state != LPORT_ST_READY) {
801		FC_FCP_DBG(fsp, "lport state %d, ignoring r_ctl %x\n",
802			   lport->state, r_ctl);
803		goto out;
804	}
805	if (fc_fcp_lock_pkt(fsp))
806		goto out;
807
808	if (fh->fh_type == FC_TYPE_BLS) {
809		fc_fcp_abts_resp(fsp, fp);
810		goto unlock;
811	}
812
813	if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING)) {
814		FC_FCP_DBG(fsp, "command aborted, ignoring r_ctl %x\n", r_ctl);
815		goto unlock;
816	}
817
818	if (r_ctl == FC_RCTL_DD_DATA_DESC) {
819		/*
820		 * received XFER RDY from the target
821		 * need to send data to the target
822		 */
823		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
824		dd = fc_frame_payload_get(fp, sizeof(*dd));
825		WARN_ON(!dd);
826
827		rc = fc_fcp_send_data(fsp, seq,
828				      (size_t) ntohl(dd->ft_data_ro),
829				      (size_t) ntohl(dd->ft_burst_len));
830		if (!rc)
831			seq->rec_data = fsp->xfer_len;
832	} else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
833		/*
834		 * received a DATA frame
835		 * next we will copy the data to the system buffer
836		 */
837		WARN_ON(fr_len(fp) < sizeof(*fh));	/* len may be 0 */
838		fc_fcp_recv_data(fsp, fp);
839		seq->rec_data = fsp->xfer_contig_end;
840	} else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
841		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
842
843		fc_fcp_resp(fsp, fp);
844	} else {
845		FC_FCP_DBG(fsp, "unexpected frame.  r_ctl %x\n", r_ctl);
846	}
847unlock:
848	fc_fcp_unlock_pkt(fsp);
849out:
850	fc_frame_free(fp);
851}
852
853/**
854 * fc_fcp_resp() - Handler for FCP responses
855 * @fsp: The FCP packet the response is for
856 * @fp:	 The response frame
857 */
858static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
859{
860	struct fc_frame_header *fh;
861	struct fcp_resp *fc_rp;
862	struct fcp_resp_ext *rp_ex;
863	struct fcp_resp_rsp_info *fc_rp_info;
864	u32 plen;
865	u32 expected_len;
866	u32 respl = 0;
867	u32 snsl = 0;
868	u8 flags = 0;
869
870	plen = fr_len(fp);
871	fh = (struct fc_frame_header *)fr_hdr(fp);
872	if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
873		goto len_err;
874	plen -= sizeof(*fh);
875	fc_rp = (struct fcp_resp *)(fh + 1);
876	fsp->cdb_status = fc_rp->fr_status;
877	flags = fc_rp->fr_flags;
878	fsp->scsi_comp_flags = flags;
879	expected_len = fsp->data_len;
880
881	/* if ddp, update xfer len */
882	fc_fcp_ddp_done(fsp);
883
884	if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
885		rp_ex = (void *)(fc_rp + 1);
886		if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
887			if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
888				goto len_err;
889			fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
890			if (flags & FCP_RSP_LEN_VAL) {
891				respl = ntohl(rp_ex->fr_rsp_len);
892				if ((respl != FCP_RESP_RSP_INFO_LEN4) &&
893				    (respl != FCP_RESP_RSP_INFO_LEN8))
894					goto len_err;
895				if (fsp->wait_for_comp) {
896					/* Abuse cdb_status for rsp code */
897					fsp->cdb_status = fc_rp_info->rsp_code;
898					complete(&fsp->tm_done);
899					/*
900					 * tmfs will not have any scsi cmd so
901					 * exit here
902					 */
903					return;
904				}
905			}
906			if (flags & FCP_SNS_LEN_VAL) {
907				snsl = ntohl(rp_ex->fr_sns_len);
908				if (snsl > SCSI_SENSE_BUFFERSIZE)
909					snsl = SCSI_SENSE_BUFFERSIZE;
910				memcpy(fsp->cmd->sense_buffer,
911				       (char *)fc_rp_info + respl, snsl);
912			}
913		}
914		if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
915			if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
916				goto len_err;
917			if (flags & FCP_RESID_UNDER) {
918				fsp->scsi_resid = ntohl(rp_ex->fr_resid);
919				/*
920				 * The cmnd->underflow is the minimum number of
921				 * bytes that must be transferred for this
922				 * command.  Provided a sense condition is not
923				 * present, make sure the actual amount
924				 * transferred is at least the underflow value
925				 * or fail.
926				 */
927				if (!(flags & FCP_SNS_LEN_VAL) &&
928				    (fc_rp->fr_status == 0) &&
929				    (scsi_bufflen(fsp->cmd) -
930				     fsp->scsi_resid) < fsp->cmd->underflow)
931					goto err;
932				expected_len -= fsp->scsi_resid;
933			} else {
934				fsp->status_code = FC_ERROR;
935			}
936		}
937	}
938	fsp->state |= FC_SRB_RCV_STATUS;
939
940	/*
941	 * Check for missing or extra data frames.
942	 */
943	if (unlikely(fsp->cdb_status == SAM_STAT_GOOD &&
944		     fsp->xfer_len != expected_len)) {
945		if (fsp->xfer_len < expected_len) {
946			/*
947			 * Some data may be queued locally,
948			 * Wait a at least one jiffy to see if it is delivered.
949			 * If this expires without data, we may do SRR.
950			 */
951			if (fsp->lp->qfull) {
952				FC_FCP_DBG(fsp, "tgt %6.6x queue busy retry\n",
953					   fsp->rport->port_id);
954				return;
955			}
956			FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx data underrun "
957				   "len %x, data len %x\n",
958				   fsp->rport->port_id,
959				   fsp->xfer_len, expected_len, fsp->data_len);
960			fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
961			return;
962		}
963		fsp->status_code = FC_DATA_OVRRUN;
964		FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx greater than expected, "
965			   "len %x, data len %x\n",
966			   fsp->rport->port_id,
967			   fsp->xfer_len, expected_len, fsp->data_len);
968	}
969	fc_fcp_complete_locked(fsp);
970	return;
971
972len_err:
973	FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
974		   "snsl %u\n", flags, fr_len(fp), respl, snsl);
975err:
976	fsp->status_code = FC_ERROR;
977	fc_fcp_complete_locked(fsp);
978}
979
980/**
981 * fc_fcp_complete_locked() - Complete processing of a fcp_pkt with the
982 *			      fcp_pkt lock held
983 * @fsp: The FCP packet to be completed
984 *
985 * This function may sleep if a timer is pending. The packet lock must be
986 * held, and the host lock must not be held.
987 */
988static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
989{
990	struct fc_lport *lport = fsp->lp;
991	struct fc_seq *seq;
992	struct fc_exch *ep;
993	u32 f_ctl;
994
995	if (fsp->state & FC_SRB_ABORT_PENDING)
996		return;
997
998	if (fsp->state & FC_SRB_ABORTED) {
999		if (!fsp->status_code)
1000			fsp->status_code = FC_CMD_ABORTED;
1001	} else {
1002		/*
1003		 * Test for transport underrun, independent of response
1004		 * underrun status.
1005		 */
1006		if (fsp->cdb_status == SAM_STAT_GOOD &&
1007		    fsp->xfer_len < fsp->data_len && !fsp->io_status &&
1008		    (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
1009		     fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
1010			FC_FCP_DBG(fsp, "data underrun, xfer %zx data %x\n",
1011				    fsp->xfer_len, fsp->data_len);
1012			fsp->status_code = FC_DATA_UNDRUN;
1013		}
1014	}
1015
1016	seq = fsp->seq_ptr;
1017	if (seq) {
1018		fsp->seq_ptr = NULL;
1019		if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
1020			struct fc_frame *conf_frame;
1021			struct fc_seq *csp;
1022
1023			csp = fc_seq_start_next(seq);
1024			conf_frame = fc_fcp_frame_alloc(fsp->lp, 0);
1025			if (conf_frame) {
1026				f_ctl = FC_FC_SEQ_INIT;
1027				f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1028				ep = fc_seq_exch(seq);
1029				fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
1030					       ep->did, ep->sid,
1031					       FC_TYPE_FCP, f_ctl, 0);
1032				fc_seq_send(lport, csp, conf_frame);
1033			}
1034		}
1035		fc_exch_done(seq);
1036	}
1037	/*
1038	 * Some resets driven by SCSI are not I/Os and do not have
1039	 * SCSI commands associated with the requests. We should not
1040	 * call I/O completion if we do not have a SCSI command.
1041	 */
1042	if (fsp->cmd)
1043		fc_io_compl(fsp);
1044}
1045
1046/**
1047 * fc_fcp_cleanup_cmd() - Cancel the active exchange on a fcp_pkt
1048 * @fsp:   The FCP packet whose exchanges should be canceled
1049 * @error: The reason for the cancellation
1050 */
1051static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
1052{
1053	if (fsp->seq_ptr) {
1054		fc_exch_done(fsp->seq_ptr);
1055		fsp->seq_ptr = NULL;
1056	}
1057	fsp->status_code = error;
1058}
1059
1060/**
1061 * fc_fcp_cleanup_each_cmd() - Cancel all exchanges on a local port
1062 * @lport: The local port whose exchanges should be canceled
1063 * @id:	   The target's ID
1064 * @lun:   The LUN
1065 * @error: The reason for cancellation
1066 *
1067 * If lun or id is -1, they are ignored.
1068 */
1069static void fc_fcp_cleanup_each_cmd(struct fc_lport *lport, unsigned int id,
1070				    unsigned int lun, int error)
1071{
1072	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1073	struct fc_fcp_pkt *fsp;
1074	struct scsi_cmnd *sc_cmd;
1075	unsigned long flags;
1076
1077	spin_lock_irqsave(&si->scsi_queue_lock, flags);
1078restart:
1079	list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
1080		sc_cmd = fsp->cmd;
1081		if (id != -1 && scmd_id(sc_cmd) != id)
1082			continue;
1083
1084		if (lun != -1 && sc_cmd->device->lun != lun)
1085			continue;
1086
1087		fc_fcp_pkt_hold(fsp);
1088		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1089
1090		spin_lock_bh(&fsp->scsi_pkt_lock);
1091		if (!(fsp->state & FC_SRB_COMPL)) {
1092			fsp->state |= FC_SRB_COMPL;
1093			/*
1094			 * TODO: dropping scsi_pkt_lock and then reacquiring
1095			 * again around fc_fcp_cleanup_cmd() is required,
1096			 * since fc_fcp_cleanup_cmd() calls into
1097			 * fc_seq_set_resp() and that func preempts cpu using
1098			 * schedule. May be schedule and related code should be
1099			 * removed instead of unlocking here to avoid scheduling
1100			 * while atomic bug.
1101			 */
1102			spin_unlock_bh(&fsp->scsi_pkt_lock);
1103
1104			fc_fcp_cleanup_cmd(fsp, error);
1105
1106			spin_lock_bh(&fsp->scsi_pkt_lock);
1107			fc_io_compl(fsp);
1108		}
1109		spin_unlock_bh(&fsp->scsi_pkt_lock);
1110
1111		fc_fcp_pkt_release(fsp);
1112		spin_lock_irqsave(&si->scsi_queue_lock, flags);
1113		/*
1114		 * while we dropped the lock multiple pkts could
1115		 * have been released, so we have to start over.
1116		 */
1117		goto restart;
1118	}
1119	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1120}
1121
1122/**
1123 * fc_fcp_abort_io() - Abort all FCP-SCSI exchanges on a local port
1124 * @lport: The local port whose exchanges are to be aborted
1125 */
1126static void fc_fcp_abort_io(struct fc_lport *lport)
1127{
1128	fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_HRD_ERROR);
1129}
1130
1131/**
1132 * fc_fcp_pkt_send() - Send a fcp_pkt
1133 * @lport: The local port to send the FCP packet on
1134 * @fsp:   The FCP packet to send
1135 *
1136 * Return:  Zero for success and -1 for failure
1137 * Locks:   Called without locks held
1138 */
1139static int fc_fcp_pkt_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp)
1140{
1141	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1142	unsigned long flags;
1143	int rc;
1144
1145	fsp->cmd->SCp.ptr = (char *)fsp;
1146	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1147	fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
1148
1149	int_to_scsilun(fsp->cmd->device->lun, &fsp->cdb_cmd.fc_lun);
1150	memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
1151
1152	spin_lock_irqsave(&si->scsi_queue_lock, flags);
1153	list_add_tail(&fsp->list, &si->scsi_pkt_queue);
1154	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1155	rc = lport->tt.fcp_cmd_send(lport, fsp, fc_fcp_recv);
1156	if (unlikely(rc)) {
1157		spin_lock_irqsave(&si->scsi_queue_lock, flags);
1158		fsp->cmd->SCp.ptr = NULL;
1159		list_del(&fsp->list);
1160		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1161	}
1162
1163	return rc;
1164}
1165
1166/**
1167 * fc_fcp_cmd_send() - Send a FCP command
1168 * @lport: The local port to send the command on
1169 * @fsp:   The FCP packet the command is on
1170 * @resp:  The handler for the response
1171 */
1172static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1173			   void (*resp)(struct fc_seq *,
1174					struct fc_frame *fp,
1175					void *arg))
1176{
1177	struct fc_frame *fp;
1178	struct fc_seq *seq;
1179	struct fc_rport *rport;
1180	struct fc_rport_libfc_priv *rpriv;
1181	const size_t len = sizeof(fsp->cdb_cmd);
1182	int rc = 0;
1183
1184	if (fc_fcp_lock_pkt(fsp))
1185		return 0;
1186
1187	fp = fc_fcp_frame_alloc(lport, sizeof(fsp->cdb_cmd));
1188	if (!fp) {
1189		rc = -1;
1190		goto unlock;
1191	}
1192
1193	memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
1194	fr_fsp(fp) = fsp;
1195	rport = fsp->rport;
1196	fsp->max_payload = rport->maxframe_size;
1197	rpriv = rport->dd_data;
1198
1199	fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
1200		       rpriv->local_port->port_id, FC_TYPE_FCP,
1201		       FC_FCTL_REQ, 0);
1202
1203	seq = fc_exch_seq_send(lport, fp, resp, fc_fcp_pkt_destroy, fsp, 0);
1204	if (!seq) {
1205		rc = -1;
1206		goto unlock;
1207	}
1208	fsp->seq_ptr = seq;
1209	fc_fcp_pkt_hold(fsp);	/* hold for fc_fcp_pkt_destroy */
1210
1211	fsp->timer.function = fc_fcp_timeout;
1212	if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1213		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1214
1215unlock:
1216	fc_fcp_unlock_pkt(fsp);
1217	return rc;
1218}
1219
1220/**
1221 * fc_fcp_error() - Handler for FCP layer errors
1222 * @fsp: The FCP packet the error is on
1223 * @fp:	 The frame that has errored
1224 */
1225static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1226{
1227	int error = PTR_ERR(fp);
1228
1229	if (fc_fcp_lock_pkt(fsp))
1230		return;
1231
1232	if (error == -FC_EX_CLOSED) {
1233		fc_fcp_retry_cmd(fsp, FC_ERROR);
1234		goto unlock;
1235	}
1236
1237	/*
1238	 * clear abort pending, because the lower layer
1239	 * decided to force completion.
1240	 */
1241	fsp->state &= ~FC_SRB_ABORT_PENDING;
1242	fsp->status_code = FC_CMD_PLOGO;
1243	fc_fcp_complete_locked(fsp);
1244unlock:
1245	fc_fcp_unlock_pkt(fsp);
1246}
1247
1248/**
1249 * fc_fcp_pkt_abort() - Abort a fcp_pkt
1250 * @fsp:   The FCP packet to abort on
1251 *
1252 * Called to send an abort and then wait for abort completion
1253 */
1254static int fc_fcp_pkt_abort(struct fc_fcp_pkt *fsp)
1255{
1256	int rc = FAILED;
1257	unsigned long ticks_left;
1258
1259	FC_FCP_DBG(fsp, "pkt abort state %x\n", fsp->state);
1260	if (fc_fcp_send_abort(fsp)) {
1261		FC_FCP_DBG(fsp, "failed to send abort\n");
1262		return FAILED;
1263	}
1264
1265	if (fsp->state & FC_SRB_ABORTED) {
1266		FC_FCP_DBG(fsp, "target abort cmd  completed\n");
1267		return SUCCESS;
1268	}
1269
1270	init_completion(&fsp->tm_done);
1271	fsp->wait_for_comp = 1;
1272
1273	spin_unlock_bh(&fsp->scsi_pkt_lock);
1274	ticks_left = wait_for_completion_timeout(&fsp->tm_done,
1275							FC_SCSI_TM_TOV);
1276	spin_lock_bh(&fsp->scsi_pkt_lock);
1277	fsp->wait_for_comp = 0;
1278
1279	if (!ticks_left) {
1280		FC_FCP_DBG(fsp, "target abort cmd  failed\n");
1281	} else if (fsp->state & FC_SRB_ABORTED) {
1282		FC_FCP_DBG(fsp, "target abort cmd  passed\n");
1283		rc = SUCCESS;
1284		fc_fcp_complete_locked(fsp);
1285	}
1286
1287	return rc;
1288}
1289
1290/**
1291 * fc_lun_reset_send() - Send LUN reset command
1292 * @t: Timer context used to fetch the FSP packet
1293 */
1294static void fc_lun_reset_send(struct timer_list *t)
1295{
1296	struct fc_fcp_pkt *fsp = from_timer(fsp, t, timer);
1297	struct fc_lport *lport = fsp->lp;
1298
1299	if (lport->tt.fcp_cmd_send(lport, fsp, fc_tm_done)) {
1300		if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
1301			return;
1302		if (fc_fcp_lock_pkt(fsp))
1303			return;
1304		fsp->timer.function = fc_lun_reset_send;
1305		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1306		fc_fcp_unlock_pkt(fsp);
1307	}
1308}
1309
1310/**
1311 * fc_lun_reset() - Send a LUN RESET command to a device
1312 *		    and wait for the reply
1313 * @lport: The local port to sent the command on
1314 * @fsp:   The FCP packet that identifies the LUN to be reset
1315 * @id:	   The SCSI command ID
1316 * @lun:   The LUN ID to be reset
1317 */
1318static int fc_lun_reset(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1319			unsigned int id, unsigned int lun)
1320{
1321	int rc;
1322
1323	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1324	fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
1325	int_to_scsilun(lun, &fsp->cdb_cmd.fc_lun);
1326
1327	fsp->wait_for_comp = 1;
1328	init_completion(&fsp->tm_done);
1329
1330	fc_lun_reset_send(&fsp->timer);
1331
1332	/*
1333	 * wait for completion of reset
1334	 * after that make sure all commands are terminated
1335	 */
1336	rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1337
1338	spin_lock_bh(&fsp->scsi_pkt_lock);
1339	fsp->state |= FC_SRB_COMPL;
1340	spin_unlock_bh(&fsp->scsi_pkt_lock);
1341
1342	del_timer_sync(&fsp->timer);
1343
1344	spin_lock_bh(&fsp->scsi_pkt_lock);
1345	if (fsp->seq_ptr) {
1346		fc_exch_done(fsp->seq_ptr);
1347		fsp->seq_ptr = NULL;
1348	}
1349	fsp->wait_for_comp = 0;
1350	spin_unlock_bh(&fsp->scsi_pkt_lock);
1351
1352	if (!rc) {
1353		FC_SCSI_DBG(lport, "lun reset failed\n");
1354		return FAILED;
1355	}
1356
1357	/* cdb_status holds the tmf's rsp code */
1358	if (fsp->cdb_status != FCP_TMF_CMPL)
1359		return FAILED;
1360
1361	FC_SCSI_DBG(lport, "lun reset to lun %u completed\n", lun);
1362	fc_fcp_cleanup_each_cmd(lport, id, lun, FC_CMD_ABORTED);
1363	return SUCCESS;
1364}
1365
1366/**
1367 * fc_tm_done() - Task Management response handler
1368 * @seq: The sequence that the response is on
1369 * @fp:	 The response frame
1370 * @arg: The FCP packet the response is for
1371 */
1372static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1373{
1374	struct fc_fcp_pkt *fsp = arg;
1375	struct fc_frame_header *fh;
1376
1377	if (IS_ERR(fp)) {
1378		/*
1379		 * If there is an error just let it timeout or wait
1380		 * for TMF to be aborted if it timedout.
1381		 *
1382		 * scsi-eh will escalate for when either happens.
1383		 */
1384		return;
1385	}
1386
1387	if (fc_fcp_lock_pkt(fsp))
1388		goto out;
1389
1390	/*
1391	 * raced with eh timeout handler.
1392	 */
1393	if (!fsp->seq_ptr || !fsp->wait_for_comp)
1394		goto out_unlock;
1395
1396	fh = fc_frame_header_get(fp);
1397	if (fh->fh_type != FC_TYPE_BLS)
1398		fc_fcp_resp(fsp, fp);
1399	fsp->seq_ptr = NULL;
1400	fc_exch_done(seq);
1401out_unlock:
1402	fc_fcp_unlock_pkt(fsp);
1403out:
1404	fc_frame_free(fp);
1405}
1406
1407/**
1408 * fc_fcp_cleanup() - Cleanup all FCP exchanges on a local port
1409 * @lport: The local port to be cleaned up
1410 */
1411static void fc_fcp_cleanup(struct fc_lport *lport)
1412{
1413	fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_ERROR);
1414}
1415
1416/**
1417 * fc_fcp_timeout() - Handler for fcp_pkt timeouts
1418 * @t: Timer context used to fetch the FSP packet
1419 *
1420 * If REC is supported then just issue it and return. The REC exchange will
1421 * complete or time out and recovery can continue at that point. Otherwise,
1422 * if the response has been received without all the data it has been
1423 * ER_TIMEOUT since the response was received. If the response has not been
1424 * received we see if data was received recently. If it has been then we
1425 * continue waiting, otherwise, we abort the command.
1426 */
1427static void fc_fcp_timeout(struct timer_list *t)
1428{
1429	struct fc_fcp_pkt *fsp = from_timer(fsp, t, timer);
1430	struct fc_rport *rport = fsp->rport;
1431	struct fc_rport_libfc_priv *rpriv = rport->dd_data;
1432
1433	if (fc_fcp_lock_pkt(fsp))
1434		return;
1435
1436	if (fsp->cdb_cmd.fc_tm_flags)
1437		goto unlock;
1438
1439	if (fsp->lp->qfull) {
1440		FC_FCP_DBG(fsp, "fcp timeout, resetting timer delay %d\n",
1441			   fsp->timer_delay);
1442		fsp->timer.function = fc_fcp_timeout;
1443		fc_fcp_timer_set(fsp, fsp->timer_delay);
1444		goto unlock;
1445	}
1446	FC_FCP_DBG(fsp, "fcp timeout, delay %d flags %x state %x\n",
1447		   fsp->timer_delay, rpriv->flags, fsp->state);
1448	fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
1449
1450	if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1451		fc_fcp_rec(fsp);
1452	else if (fsp->state & FC_SRB_RCV_STATUS)
1453		fc_fcp_complete_locked(fsp);
1454	else
1455		fc_fcp_recovery(fsp, FC_TIMED_OUT);
1456	fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
1457unlock:
1458	fc_fcp_unlock_pkt(fsp);
1459}
1460
1461/**
1462 * fc_fcp_rec() - Send a REC ELS request
1463 * @fsp: The FCP packet to send the REC request on
1464 */
1465static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
1466{
1467	struct fc_lport *lport;
1468	struct fc_frame *fp;
1469	struct fc_rport *rport;
1470	struct fc_rport_libfc_priv *rpriv;
1471
1472	lport = fsp->lp;
1473	rport = fsp->rport;
1474	rpriv = rport->dd_data;
1475	if (!fsp->seq_ptr || rpriv->rp_state != RPORT_ST_READY) {
1476		fsp->status_code = FC_HRD_ERROR;
1477		fsp->io_status = 0;
1478		fc_fcp_complete_locked(fsp);
1479		return;
1480	}
1481
1482	fp = fc_fcp_frame_alloc(lport, sizeof(struct fc_els_rec));
1483	if (!fp)
1484		goto retry;
1485
1486	fr_seq(fp) = fsp->seq_ptr;
1487	fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
1488		       rpriv->local_port->port_id, FC_TYPE_ELS,
1489		       FC_FCTL_REQ, 0);
1490	if (lport->tt.elsct_send(lport, rport->port_id, fp, ELS_REC,
1491				 fc_fcp_rec_resp, fsp,
1492				 2 * lport->r_a_tov)) {
1493		fc_fcp_pkt_hold(fsp);		/* hold while REC outstanding */
1494		return;
1495	}
1496retry:
1497	if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1498		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1499	else
1500		fc_fcp_recovery(fsp, FC_TIMED_OUT);
1501}
1502
1503/**
1504 * fc_fcp_rec_resp() - Handler for REC ELS responses
1505 * @seq: The sequence the response is on
1506 * @fp:	 The response frame
1507 * @arg: The FCP packet the response is on
1508 *
1509 * If the response is a reject then the scsi layer will handle
1510 * the timeout. If the response is a LS_ACC then if the I/O was not completed
1511 * set the timeout and return. If the I/O was completed then complete the
1512 * exchange and tell the SCSI layer.
1513 */
1514static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1515{
1516	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
1517	struct fc_els_rec_acc *recp;
1518	struct fc_els_ls_rjt *rjt;
1519	u32 e_stat;
1520	u8 opcode;
1521	u32 offset;
1522	enum dma_data_direction data_dir;
1523	enum fc_rctl r_ctl;
1524	struct fc_rport_libfc_priv *rpriv;
1525
1526	if (IS_ERR(fp)) {
1527		fc_fcp_rec_error(fsp, fp);
1528		return;
1529	}
1530
1531	if (fc_fcp_lock_pkt(fsp))
1532		goto out;
1533
1534	fsp->recov_retry = 0;
1535	opcode = fc_frame_payload_op(fp);
1536	if (opcode == ELS_LS_RJT) {
1537		rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1538		switch (rjt->er_reason) {
1539		default:
1540			FC_FCP_DBG(fsp,
1541				   "device %x invalid REC reject %d/%d\n",
1542				   fsp->rport->port_id, rjt->er_reason,
1543				   rjt->er_explan);
1544			fallthrough;
1545		case ELS_RJT_UNSUP:
1546			FC_FCP_DBG(fsp, "device does not support REC\n");
1547			rpriv = fsp->rport->dd_data;
1548			/*
1549			 * if we do not spport RECs or got some bogus
1550			 * reason then resetup timer so we check for
1551			 * making progress.
1552			 */
1553			rpriv->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
1554			break;
1555		case ELS_RJT_LOGIC:
1556		case ELS_RJT_UNAB:
1557			FC_FCP_DBG(fsp, "device %x REC reject %d/%d\n",
1558				   fsp->rport->port_id, rjt->er_reason,
1559				   rjt->er_explan);
1560			/*
1561			 * If response got lost or is stuck in the
1562			 * queue somewhere we have no idea if and when
1563			 * the response will be received. So quarantine
1564			 * the xid and retry the command.
1565			 */
1566			if (rjt->er_explan == ELS_EXPL_OXID_RXID) {
1567				struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1568				ep->state |= FC_EX_QUARANTINE;
1569				fsp->state |= FC_SRB_ABORTED;
1570				fc_fcp_retry_cmd(fsp, FC_TRANS_RESET);
1571				break;
1572			}
1573			fc_fcp_recovery(fsp, FC_TRANS_RESET);
1574			break;
1575		}
1576	} else if (opcode == ELS_LS_ACC) {
1577		if (fsp->state & FC_SRB_ABORTED)
1578			goto unlock_out;
1579
1580		data_dir = fsp->cmd->sc_data_direction;
1581		recp = fc_frame_payload_get(fp, sizeof(*recp));
1582		offset = ntohl(recp->reca_fc4value);
1583		e_stat = ntohl(recp->reca_e_stat);
1584
1585		if (e_stat & ESB_ST_COMPLETE) {
1586
1587			/*
1588			 * The exchange is complete.
1589			 *
1590			 * For output, we must've lost the response.
1591			 * For input, all data must've been sent.
1592			 * We lost may have lost the response
1593			 * (and a confirmation was requested) and maybe
1594			 * some data.
1595			 *
1596			 * If all data received, send SRR
1597			 * asking for response.	 If partial data received,
1598			 * or gaps, SRR requests data at start of gap.
1599			 * Recovery via SRR relies on in-order-delivery.
1600			 */
1601			if (data_dir == DMA_TO_DEVICE) {
1602				r_ctl = FC_RCTL_DD_CMD_STATUS;
1603			} else if (fsp->xfer_contig_end == offset) {
1604				r_ctl = FC_RCTL_DD_CMD_STATUS;
1605			} else {
1606				offset = fsp->xfer_contig_end;
1607				r_ctl = FC_RCTL_DD_SOL_DATA;
1608			}
1609			fc_fcp_srr(fsp, r_ctl, offset);
1610		} else if (e_stat & ESB_ST_SEQ_INIT) {
1611			/*
1612			 * The remote port has the initiative, so just
1613			 * keep waiting for it to complete.
1614			 */
1615			fc_fcp_timer_set(fsp,  get_fsp_rec_tov(fsp));
1616		} else {
1617
1618			/*
1619			 * The exchange is incomplete, we have seq. initiative.
1620			 * Lost response with requested confirmation,
1621			 * lost confirmation, lost transfer ready or
1622			 * lost write data.
1623			 *
1624			 * For output, if not all data was received, ask
1625			 * for transfer ready to be repeated.
1626			 *
1627			 * If we received or sent all the data, send SRR to
1628			 * request response.
1629			 *
1630			 * If we lost a response, we may have lost some read
1631			 * data as well.
1632			 */
1633			r_ctl = FC_RCTL_DD_SOL_DATA;
1634			if (data_dir == DMA_TO_DEVICE) {
1635				r_ctl = FC_RCTL_DD_CMD_STATUS;
1636				if (offset < fsp->data_len)
1637					r_ctl = FC_RCTL_DD_DATA_DESC;
1638			} else if (offset == fsp->xfer_contig_end) {
1639				r_ctl = FC_RCTL_DD_CMD_STATUS;
1640			} else if (fsp->xfer_contig_end < offset) {
1641				offset = fsp->xfer_contig_end;
1642			}
1643			fc_fcp_srr(fsp, r_ctl, offset);
1644		}
1645	}
1646unlock_out:
1647	fc_fcp_unlock_pkt(fsp);
1648out:
1649	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
1650	fc_frame_free(fp);
1651}
1652
1653/**
1654 * fc_fcp_rec_error() - Handler for REC errors
1655 * @fsp: The FCP packet the error is on
1656 * @fp:	 The REC frame
1657 */
1658static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1659{
1660	int error = PTR_ERR(fp);
1661
1662	if (fc_fcp_lock_pkt(fsp))
1663		goto out;
1664
1665	switch (error) {
1666	case -FC_EX_CLOSED:
1667		FC_FCP_DBG(fsp, "REC %p fid %6.6x exchange closed\n",
1668			   fsp, fsp->rport->port_id);
1669		fc_fcp_retry_cmd(fsp, FC_ERROR);
1670		break;
1671
1672	default:
1673		FC_FCP_DBG(fsp, "REC %p fid %6.6x error unexpected error %d\n",
1674			   fsp, fsp->rport->port_id, error);
1675		fsp->status_code = FC_CMD_PLOGO;
1676		fallthrough;
1677
1678	case -FC_EX_TIMEOUT:
1679		/*
1680		 * Assume REC or LS_ACC was lost.
1681		 * The exchange manager will have aborted REC, so retry.
1682		 */
1683		FC_FCP_DBG(fsp, "REC %p fid %6.6x exchange timeout retry %d/%d\n",
1684			   fsp, fsp->rport->port_id, fsp->recov_retry,
1685			   FC_MAX_RECOV_RETRY);
1686		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1687			fc_fcp_rec(fsp);
1688		else
1689			fc_fcp_recovery(fsp, FC_TIMED_OUT);
1690		break;
1691	}
1692	fc_fcp_unlock_pkt(fsp);
1693out:
1694	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
1695}
1696
1697/**
1698 * fc_fcp_recovery() - Handler for fcp_pkt recovery
1699 * @fsp: The FCP pkt that needs to be aborted
1700 * @code: The FCP status code to set
1701 */
1702static void fc_fcp_recovery(struct fc_fcp_pkt *fsp, u8 code)
1703{
1704	FC_FCP_DBG(fsp, "start recovery code %x\n", code);
1705	fsp->status_code = code;
1706	fsp->cdb_status = 0;
1707	fsp->io_status = 0;
1708	if (!fsp->cmd)
1709		/*
1710		 * Only abort non-scsi commands; otherwise let the
1711		 * scsi command timer fire and scsi-ml escalate.
1712		 */
1713		fc_fcp_send_abort(fsp);
1714}
1715
1716/**
1717 * fc_fcp_srr() - Send a SRR request (Sequence Retransmission Request)
1718 * @fsp:   The FCP packet the SRR is to be sent on
1719 * @r_ctl: The R_CTL field for the SRR request
1720 * @offset: The SRR relative offset
1721 * This is called after receiving status but insufficient data, or
1722 * when expecting status but the request has timed out.
1723 */
1724static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
1725{
1726	struct fc_lport *lport = fsp->lp;
1727	struct fc_rport *rport;
1728	struct fc_rport_libfc_priv *rpriv;
1729	struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1730	struct fc_seq *seq;
1731	struct fcp_srr *srr;
1732	struct fc_frame *fp;
1733
1734	rport = fsp->rport;
1735	rpriv = rport->dd_data;
1736
1737	if (!(rpriv->flags & FC_RP_FLAGS_RETRY) ||
1738	    rpriv->rp_state != RPORT_ST_READY)
1739		goto retry;			/* shouldn't happen */
1740	fp = fc_fcp_frame_alloc(lport, sizeof(*srr));
1741	if (!fp)
1742		goto retry;
1743
1744	srr = fc_frame_payload_get(fp, sizeof(*srr));
1745	memset(srr, 0, sizeof(*srr));
1746	srr->srr_op = ELS_SRR;
1747	srr->srr_ox_id = htons(ep->oxid);
1748	srr->srr_rx_id = htons(ep->rxid);
1749	srr->srr_r_ctl = r_ctl;
1750	srr->srr_rel_off = htonl(offset);
1751
1752	fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
1753		       rpriv->local_port->port_id, FC_TYPE_FCP,
1754		       FC_FCTL_REQ, 0);
1755
1756	seq = fc_exch_seq_send(lport, fp, fc_fcp_srr_resp,
1757			       fc_fcp_pkt_destroy,
1758			       fsp, get_fsp_rec_tov(fsp));
1759	if (!seq)
1760		goto retry;
1761
1762	fsp->recov_seq = seq;
1763	fsp->xfer_len = offset;
1764	fsp->xfer_contig_end = offset;
1765	fsp->state &= ~FC_SRB_RCV_STATUS;
1766	fc_fcp_pkt_hold(fsp);		/* hold for outstanding SRR */
1767	return;
1768retry:
1769	fc_fcp_retry_cmd(fsp, FC_TRANS_RESET);
1770}
1771
1772/**
1773 * fc_fcp_srr_resp() - Handler for SRR response
1774 * @seq: The sequence the SRR is on
1775 * @fp:	 The SRR frame
1776 * @arg: The FCP packet the SRR is on
1777 */
1778static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1779{
1780	struct fc_fcp_pkt *fsp = arg;
1781	struct fc_frame_header *fh;
1782
1783	if (IS_ERR(fp)) {
1784		fc_fcp_srr_error(fsp, fp);
1785		return;
1786	}
1787
1788	if (fc_fcp_lock_pkt(fsp))
1789		goto out;
1790
1791	fh = fc_frame_header_get(fp);
1792	/*
1793	 * BUG? fc_fcp_srr_error calls fc_exch_done which would release
1794	 * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
1795	 * then fc_exch_timeout would be sending an abort. The fc_exch_done
1796	 * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
1797	 * an abort response though.
1798	 */
1799	if (fh->fh_type == FC_TYPE_BLS) {
1800		fc_fcp_unlock_pkt(fsp);
1801		return;
1802	}
1803
1804	switch (fc_frame_payload_op(fp)) {
1805	case ELS_LS_ACC:
1806		fsp->recov_retry = 0;
1807		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1808		break;
1809	case ELS_LS_RJT:
1810	default:
1811		fc_fcp_recovery(fsp, FC_ERROR);
1812		break;
1813	}
1814	fc_fcp_unlock_pkt(fsp);
1815out:
1816	fc_exch_done(seq);
1817	fc_frame_free(fp);
1818}
1819
1820/**
1821 * fc_fcp_srr_error() - Handler for SRR errors
1822 * @fsp: The FCP packet that the SRR error is on
1823 * @fp:	 The SRR frame
1824 */
1825static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1826{
1827	if (fc_fcp_lock_pkt(fsp))
1828		goto out;
1829	switch (PTR_ERR(fp)) {
1830	case -FC_EX_TIMEOUT:
1831		FC_FCP_DBG(fsp, "SRR timeout, retries %d\n", fsp->recov_retry);
1832		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1833			fc_fcp_rec(fsp);
1834		else
1835			fc_fcp_recovery(fsp, FC_TIMED_OUT);
1836		break;
1837	case -FC_EX_CLOSED:			/* e.g., link failure */
1838		FC_FCP_DBG(fsp, "SRR error, exchange closed\n");
1839		fallthrough;
1840	default:
1841		fc_fcp_retry_cmd(fsp, FC_ERROR);
1842		break;
1843	}
1844	fc_fcp_unlock_pkt(fsp);
1845out:
1846	fc_exch_done(fsp->recov_seq);
1847}
1848
1849/**
1850 * fc_fcp_lport_queue_ready() - Determine if the lport and it's queue is ready
1851 * @lport: The local port to be checked
1852 */
1853static inline int fc_fcp_lport_queue_ready(struct fc_lport *lport)
1854{
1855	/* lock ? */
1856	return (lport->state == LPORT_ST_READY) &&
1857		lport->link_up && !lport->qfull;
1858}
1859
1860/**
1861 * fc_queuecommand() - The queuecommand function of the SCSI template
1862 * @shost: The Scsi_Host that the command was issued to
1863 * @sc_cmd:   The scsi_cmnd to be executed
1864 *
1865 * This is the i/o strategy routine, called by the SCSI layer.
1866 */
1867int fc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *sc_cmd)
1868{
1869	struct fc_lport *lport = shost_priv(shost);
1870	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1871	struct fc_fcp_pkt *fsp;
1872	int rval;
1873	int rc = 0;
1874	struct fc_stats *stats;
1875
1876	rval = fc_remote_port_chkready(rport);
1877	if (rval) {
1878		sc_cmd->result = rval;
1879		sc_cmd->scsi_done(sc_cmd);
1880		return 0;
1881	}
1882
1883	if (!*(struct fc_remote_port **)rport->dd_data) {
1884		/*
1885		 * rport is transitioning from blocked/deleted to
1886		 * online
1887		 */
1888		sc_cmd->result = DID_IMM_RETRY << 16;
1889		sc_cmd->scsi_done(sc_cmd);
1890		goto out;
1891	}
1892
1893	if (!fc_fcp_lport_queue_ready(lport)) {
1894		if (lport->qfull) {
1895			if (fc_fcp_can_queue_ramp_down(lport))
1896				shost_printk(KERN_ERR, lport->host,
1897					     "libfc: queue full, "
1898					     "reducing can_queue to %d.\n",
1899					     lport->host->can_queue);
1900		}
1901		rc = SCSI_MLQUEUE_HOST_BUSY;
1902		goto out;
1903	}
1904
1905	fsp = fc_fcp_pkt_alloc(lport, GFP_ATOMIC);
1906	if (fsp == NULL) {
1907		rc = SCSI_MLQUEUE_HOST_BUSY;
1908		goto out;
1909	}
1910
1911	/*
1912	 * build the libfc request pkt
1913	 */
1914	fsp->cmd = sc_cmd;	/* save the cmd */
1915	fsp->rport = rport;	/* set the remote port ptr */
1916
1917	/*
1918	 * set up the transfer length
1919	 */
1920	fsp->data_len = scsi_bufflen(sc_cmd);
1921	fsp->xfer_len = 0;
1922
1923	/*
1924	 * setup the data direction
1925	 */
1926	stats = per_cpu_ptr(lport->stats, get_cpu());
1927	if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
1928		fsp->req_flags = FC_SRB_READ;
1929		stats->InputRequests++;
1930		stats->InputBytes += fsp->data_len;
1931	} else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
1932		fsp->req_flags = FC_SRB_WRITE;
1933		stats->OutputRequests++;
1934		stats->OutputBytes += fsp->data_len;
1935	} else {
1936		fsp->req_flags = 0;
1937		stats->ControlRequests++;
1938	}
1939	put_cpu();
1940
1941	/*
1942	 * send it to the lower layer
1943	 * if we get -1 return then put the request in the pending
1944	 * queue.
1945	 */
1946	rval = fc_fcp_pkt_send(lport, fsp);
1947	if (rval != 0) {
1948		fsp->state = FC_SRB_FREE;
1949		fc_fcp_pkt_release(fsp);
1950		rc = SCSI_MLQUEUE_HOST_BUSY;
1951	}
1952out:
1953	return rc;
1954}
1955EXPORT_SYMBOL(fc_queuecommand);
1956
1957/**
1958 * fc_io_compl() - Handle responses for completed commands
1959 * @fsp: The FCP packet that is complete
1960 *
1961 * Translates fcp_pkt errors to a Linux SCSI errors.
1962 * The fcp packet lock must be held when calling.
1963 */
1964static void fc_io_compl(struct fc_fcp_pkt *fsp)
1965{
1966	struct fc_fcp_internal *si;
1967	struct scsi_cmnd *sc_cmd;
1968	struct fc_lport *lport;
1969	unsigned long flags;
1970
1971	/* release outstanding ddp context */
1972	fc_fcp_ddp_done(fsp);
1973
1974	fsp->state |= FC_SRB_COMPL;
1975	if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
1976		spin_unlock_bh(&fsp->scsi_pkt_lock);
1977		del_timer_sync(&fsp->timer);
1978		spin_lock_bh(&fsp->scsi_pkt_lock);
1979	}
1980
1981	lport = fsp->lp;
1982	si = fc_get_scsi_internal(lport);
1983
1984	/*
1985	 * if can_queue ramp down is done then try can_queue ramp up
1986	 * since commands are completing now.
1987	 */
1988	if (si->last_can_queue_ramp_down_time)
1989		fc_fcp_can_queue_ramp_up(lport);
1990
1991	sc_cmd = fsp->cmd;
1992	CMD_SCSI_STATUS(sc_cmd) = fsp->cdb_status;
1993	switch (fsp->status_code) {
1994	case FC_COMPLETE:
1995		if (fsp->cdb_status == 0) {
1996			/*
1997			 * good I/O status
1998			 */
1999			sc_cmd->result = DID_OK << 16;
2000			if (fsp->scsi_resid)
2001				CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
2002		} else {
2003			/*
2004			 * transport level I/O was ok but scsi
2005			 * has non zero status
2006			 */
2007			sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
2008		}
2009		break;
2010	case FC_ERROR:
2011		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2012			   "due to FC_ERROR\n");
2013		sc_cmd->result = DID_ERROR << 16;
2014		break;
2015	case FC_DATA_UNDRUN:
2016		if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) {
2017			/*
2018			 * scsi status is good but transport level
2019			 * underrun.
2020			 */
2021			if (fsp->state & FC_SRB_RCV_STATUS) {
2022				sc_cmd->result = DID_OK << 16;
2023			} else {
2024				FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml"
2025					   " due to FC_DATA_UNDRUN (trans)\n");
2026				sc_cmd->result = DID_ERROR << 16;
2027			}
2028		} else {
2029			/*
2030			 * scsi got underrun, this is an error
2031			 */
2032			FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2033				   "due to FC_DATA_UNDRUN (scsi)\n");
2034			CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
2035			sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
2036		}
2037		break;
2038	case FC_DATA_OVRRUN:
2039		/*
2040		 * overrun is an error
2041		 */
2042		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2043			   "due to FC_DATA_OVRRUN\n");
2044		sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
2045		break;
2046	case FC_CMD_ABORTED:
2047		if (host_byte(sc_cmd->result) == DID_TIME_OUT)
2048			FC_FCP_DBG(fsp, "Returning DID_TIME_OUT to scsi-ml "
2049				   "due to FC_CMD_ABORTED\n");
2050		else {
2051			FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2052				   "due to FC_CMD_ABORTED\n");
2053			set_host_byte(sc_cmd, DID_ERROR);
2054		}
2055		sc_cmd->result |= fsp->io_status;
2056		break;
2057	case FC_CMD_RESET:
2058		FC_FCP_DBG(fsp, "Returning DID_RESET to scsi-ml "
2059			   "due to FC_CMD_RESET\n");
2060		sc_cmd->result = (DID_RESET << 16);
2061		break;
2062	case FC_TRANS_RESET:
2063		FC_FCP_DBG(fsp, "Returning DID_SOFT_ERROR to scsi-ml "
2064			   "due to FC_TRANS_RESET\n");
2065		sc_cmd->result = (DID_SOFT_ERROR << 16);
2066		break;
2067	case FC_HRD_ERROR:
2068		FC_FCP_DBG(fsp, "Returning DID_NO_CONNECT to scsi-ml "
2069			   "due to FC_HRD_ERROR\n");
2070		sc_cmd->result = (DID_NO_CONNECT << 16);
2071		break;
2072	case FC_CRC_ERROR:
2073		FC_FCP_DBG(fsp, "Returning DID_PARITY to scsi-ml "
2074			   "due to FC_CRC_ERROR\n");
2075		sc_cmd->result = (DID_PARITY << 16);
2076		break;
2077	case FC_TIMED_OUT:
2078		FC_FCP_DBG(fsp, "Returning DID_BUS_BUSY to scsi-ml "
2079			   "due to FC_TIMED_OUT\n");
2080		sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
2081		break;
2082	default:
2083		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2084			   "due to unknown error\n");
2085		sc_cmd->result = (DID_ERROR << 16);
2086		break;
2087	}
2088
2089	if (lport->state != LPORT_ST_READY && fsp->status_code != FC_COMPLETE)
2090		sc_cmd->result = (DID_TRANSPORT_DISRUPTED << 16);
2091
2092	spin_lock_irqsave(&si->scsi_queue_lock, flags);
2093	list_del(&fsp->list);
2094	sc_cmd->SCp.ptr = NULL;
2095	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2096	sc_cmd->scsi_done(sc_cmd);
2097
2098	/* release ref from initial allocation in queue command */
2099	fc_fcp_pkt_release(fsp);
2100}
2101
2102/**
2103 * fc_eh_abort() - Abort a command
2104 * @sc_cmd: The SCSI command to abort
2105 *
2106 * From SCSI host template.
2107 * Send an ABTS to the target device and wait for the response.
2108 */
2109int fc_eh_abort(struct scsi_cmnd *sc_cmd)
2110{
2111	struct fc_fcp_pkt *fsp;
2112	struct fc_lport *lport;
2113	struct fc_fcp_internal *si;
2114	int rc = FAILED;
2115	unsigned long flags;
2116	int rval;
2117
2118	rval = fc_block_scsi_eh(sc_cmd);
2119	if (rval)
2120		return rval;
2121
2122	lport = shost_priv(sc_cmd->device->host);
2123	if (lport->state != LPORT_ST_READY)
2124		return rc;
2125	else if (!lport->link_up)
2126		return rc;
2127
2128	si = fc_get_scsi_internal(lport);
2129	spin_lock_irqsave(&si->scsi_queue_lock, flags);
2130	fsp = CMD_SP(sc_cmd);
2131	if (!fsp) {
2132		/* command completed while scsi eh was setting up */
2133		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2134		return SUCCESS;
2135	}
2136	/* grab a ref so the fsp and sc_cmd cannot be released from under us */
2137	fc_fcp_pkt_hold(fsp);
2138	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2139
2140	if (fc_fcp_lock_pkt(fsp)) {
2141		/* completed while we were waiting for timer to be deleted */
2142		rc = SUCCESS;
2143		goto release_pkt;
2144	}
2145
2146	rc = fc_fcp_pkt_abort(fsp);
2147	fc_fcp_unlock_pkt(fsp);
2148
2149release_pkt:
2150	fc_fcp_pkt_release(fsp);
2151	return rc;
2152}
2153EXPORT_SYMBOL(fc_eh_abort);
2154
2155/**
2156 * fc_eh_device_reset() - Reset a single LUN
2157 * @sc_cmd: The SCSI command which identifies the device whose
2158 *	    LUN is to be reset
2159 *
2160 * Set from SCSI host template.
2161 */
2162int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
2163{
2164	struct fc_lport *lport;
2165	struct fc_fcp_pkt *fsp;
2166	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
2167	int rc = FAILED;
2168	int rval;
2169
2170	rval = fc_block_scsi_eh(sc_cmd);
2171	if (rval)
2172		return rval;
2173
2174	lport = shost_priv(sc_cmd->device->host);
2175
2176	if (lport->state != LPORT_ST_READY)
2177		return rc;
2178
2179	FC_SCSI_DBG(lport, "Resetting rport (%6.6x)\n", rport->port_id);
2180
2181	fsp = fc_fcp_pkt_alloc(lport, GFP_NOIO);
2182	if (fsp == NULL) {
2183		printk(KERN_WARNING "libfc: could not allocate scsi_pkt\n");
2184		goto out;
2185	}
2186
2187	/*
2188	 * Build the libfc request pkt. Do not set the scsi cmnd, because
2189	 * the sc passed in is not setup for execution like when sent
2190	 * through the queuecommand callout.
2191	 */
2192	fsp->rport = rport;	/* set the remote port ptr */
2193
2194	/*
2195	 * flush outstanding commands
2196	 */
2197	rc = fc_lun_reset(lport, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
2198	fsp->state = FC_SRB_FREE;
2199	fc_fcp_pkt_release(fsp);
2200
2201out:
2202	return rc;
2203}
2204EXPORT_SYMBOL(fc_eh_device_reset);
2205
2206/**
2207 * fc_eh_host_reset() - Reset a Scsi_Host.
2208 * @sc_cmd: The SCSI command that identifies the SCSI host to be reset
2209 */
2210int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
2211{
2212	struct Scsi_Host *shost = sc_cmd->device->host;
2213	struct fc_lport *lport = shost_priv(shost);
2214	unsigned long wait_tmo;
2215
2216	FC_SCSI_DBG(lport, "Resetting host\n");
2217
2218	fc_lport_reset(lport);
2219	wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
2220	while (!fc_fcp_lport_queue_ready(lport) && time_before(jiffies,
2221							       wait_tmo))
2222		msleep(1000);
2223
2224	if (fc_fcp_lport_queue_ready(lport)) {
2225		shost_printk(KERN_INFO, shost, "libfc: Host reset succeeded "
2226			     "on port (%6.6x)\n", lport->port_id);
2227		return SUCCESS;
2228	} else {
2229		shost_printk(KERN_INFO, shost, "libfc: Host reset failed, "
2230			     "port (%6.6x) is not ready.\n",
2231			     lport->port_id);
2232		return FAILED;
2233	}
2234}
2235EXPORT_SYMBOL(fc_eh_host_reset);
2236
2237/**
2238 * fc_slave_alloc() - Configure the queue depth of a Scsi_Host
2239 * @sdev: The SCSI device that identifies the SCSI host
2240 *
2241 * Configures queue depth based on host's cmd_per_len. If not set
2242 * then we use the libfc default.
2243 */
2244int fc_slave_alloc(struct scsi_device *sdev)
2245{
2246	struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
2247
2248	if (!rport || fc_remote_port_chkready(rport))
2249		return -ENXIO;
2250
2251	scsi_change_queue_depth(sdev, FC_FCP_DFLT_QUEUE_DEPTH);
2252	return 0;
2253}
2254EXPORT_SYMBOL(fc_slave_alloc);
2255
2256/**
2257 * fc_fcp_destory() - Tear down the FCP layer for a given local port
2258 * @lport: The local port that no longer needs the FCP layer
2259 */
2260void fc_fcp_destroy(struct fc_lport *lport)
2261{
2262	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
2263
2264	if (!list_empty(&si->scsi_pkt_queue))
2265		printk(KERN_ERR "libfc: Leaked SCSI packets when destroying "
2266		       "port (%6.6x)\n", lport->port_id);
2267
2268	mempool_destroy(si->scsi_pkt_pool);
2269	kfree(si);
2270	lport->scsi_priv = NULL;
2271}
2272EXPORT_SYMBOL(fc_fcp_destroy);
2273
2274int fc_setup_fcp(void)
2275{
2276	int rc = 0;
2277
2278	scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
2279					    sizeof(struct fc_fcp_pkt),
2280					    0, SLAB_HWCACHE_ALIGN, NULL);
2281	if (!scsi_pkt_cachep) {
2282		printk(KERN_ERR "libfc: Unable to allocate SRB cache, "
2283		       "module load failed!");
2284		rc = -ENOMEM;
2285	}
2286
2287	return rc;
2288}
2289
2290void fc_destroy_fcp(void)
2291{
2292	kmem_cache_destroy(scsi_pkt_cachep);
2293}
2294
2295/**
2296 * fc_fcp_init() - Initialize the FCP layer for a local port
2297 * @lport: The local port to initialize the exchange layer for
2298 */
2299int fc_fcp_init(struct fc_lport *lport)
2300{
2301	int rc;
2302	struct fc_fcp_internal *si;
2303
2304	if (!lport->tt.fcp_cmd_send)
2305		lport->tt.fcp_cmd_send = fc_fcp_cmd_send;
2306
2307	if (!lport->tt.fcp_cleanup)
2308		lport->tt.fcp_cleanup = fc_fcp_cleanup;
2309
2310	if (!lport->tt.fcp_abort_io)
2311		lport->tt.fcp_abort_io = fc_fcp_abort_io;
2312
2313	si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
2314	if (!si)
2315		return -ENOMEM;
2316	lport->scsi_priv = si;
2317	si->max_can_queue = lport->host->can_queue;
2318	INIT_LIST_HEAD(&si->scsi_pkt_queue);
2319	spin_lock_init(&si->scsi_queue_lock);
2320
2321	si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
2322	if (!si->scsi_pkt_pool) {
2323		rc = -ENOMEM;
2324		goto free_internal;
2325	}
2326	return 0;
2327
2328free_internal:
2329	kfree(si);
2330	return rc;
2331}
2332EXPORT_SYMBOL(fc_fcp_init);
2333