Merge branch 'libnvdimm-for-next' of git://git.kernel.org/pub/scm/linux/kernel/git...
[sfrench/cifs-2.6.git] / drivers / scsi / libfc / fc_fcp.c
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
45 static 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  */
78 struct 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  */
93 static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
94 static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
95 static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
96 static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
97 static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
98 static void fc_fcp_error(struct fc_fcp_pkt *, struct fc_frame *);
99 static void fc_fcp_recovery(struct fc_fcp_pkt *, u8 code);
100 static void fc_fcp_timeout(unsigned long);
101 static void fc_fcp_rec(struct fc_fcp_pkt *);
102 static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
103 static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
104 static void fc_io_compl(struct fc_fcp_pkt *);
105
106 static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
107 static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
108 static 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 #define FC_TRANS_RESET          12
126
127 /*
128  * Error recovery timeout values.
129  */
130 #define FC_SCSI_TM_TOV          (10 * HZ)
131 #define FC_HOST_RESET_TIMEOUT   (30 * HZ)
132 #define FC_CAN_QUEUE_PERIOD     (60 * HZ)
133
134 #define FC_MAX_ERROR_CNT        5
135 #define FC_MAX_RECOV_RETRY      3
136
137 #define FC_FCP_DFLT_QUEUE_DEPTH 32
138
139 /**
140  * fc_fcp_pkt_alloc() - Allocate a fcp_pkt
141  * @lport: The local port that the FCP packet is for
142  * @gfp:   GFP flags for allocation
143  *
144  * Return value: fcp_pkt structure or null on allocation failure.
145  * Context:      Can be called from process context, no lock is required.
146  */
147 static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lport, gfp_t gfp)
148 {
149         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
150         struct fc_fcp_pkt *fsp;
151
152         fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
153         if (fsp) {
154                 memset(fsp, 0, sizeof(*fsp));
155                 fsp->lp = lport;
156                 fsp->xfer_ddp = FC_XID_UNKNOWN;
157                 refcount_set(&fsp->ref_cnt, 1);
158                 init_timer(&fsp->timer);
159                 fsp->timer.data = (unsigned long)fsp;
160                 INIT_LIST_HEAD(&fsp->list);
161                 spin_lock_init(&fsp->scsi_pkt_lock);
162         } else {
163                 per_cpu_ptr(lport->stats, get_cpu())->FcpPktAllocFails++;
164                 put_cpu();
165         }
166         return fsp;
167 }
168
169 /**
170  * fc_fcp_pkt_release() - Release hold on a fcp_pkt
171  * @fsp: The FCP packet to be released
172  *
173  * Context: Can be called from process or interrupt context,
174  *          no lock is required.
175  */
176 static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
177 {
178         if (refcount_dec_and_test(&fsp->ref_cnt)) {
179                 struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
180
181                 mempool_free(fsp, si->scsi_pkt_pool);
182         }
183 }
184
185 /**
186  * fc_fcp_pkt_hold() - Hold a fcp_pkt
187  * @fsp: The FCP packet to be held
188  */
189 static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
190 {
191         refcount_inc(&fsp->ref_cnt);
192 }
193
194 /**
195  * fc_fcp_pkt_destroy() - Release hold on a fcp_pkt
196  * @seq: The sequence that the FCP packet is on (required by destructor API)
197  * @fsp: The FCP packet to be released
198  *
199  * This routine is called by a destructor callback in the fc_exch_seq_send()
200  * routine of the libfc Transport Template. The 'struct fc_seq' is a required
201  * argument even though it is not used by this routine.
202  *
203  * Context: No locking required.
204  */
205 static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
206 {
207         fc_fcp_pkt_release(fsp);
208 }
209
210 /**
211  * fc_fcp_lock_pkt() - Lock a fcp_pkt and increase its reference count
212  * @fsp: The FCP packet to be locked and incremented
213  *
214  * We should only return error if we return a command to SCSI-ml before
215  * getting a response. This can happen in cases where we send a abort, but
216  * do not wait for the response and the abort and command can be passing
217  * each other on the wire/network-layer.
218  *
219  * Note: this function locks the packet and gets a reference to allow
220  * callers to call the completion function while the lock is held and
221  * not have to worry about the packets refcount.
222  *
223  * TODO: Maybe we should just have callers grab/release the lock and
224  * have a function that they call to verify the fsp and grab a ref if
225  * needed.
226  */
227 static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
228 {
229         spin_lock_bh(&fsp->scsi_pkt_lock);
230         if (fsp->state & FC_SRB_COMPL) {
231                 spin_unlock_bh(&fsp->scsi_pkt_lock);
232                 return -EPERM;
233         }
234
235         fc_fcp_pkt_hold(fsp);
236         return 0;
237 }
238
239 /**
240  * fc_fcp_unlock_pkt() - Release a fcp_pkt's lock and decrement its
241  *                       reference count
242  * @fsp: The FCP packet to be unlocked and decremented
243  */
244 static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
245 {
246         spin_unlock_bh(&fsp->scsi_pkt_lock);
247         fc_fcp_pkt_release(fsp);
248 }
249
250 /**
251  * fc_fcp_timer_set() - Start a timer for a fcp_pkt
252  * @fsp:   The FCP packet to start a timer for
253  * @delay: The timeout period in jiffies
254  */
255 static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
256 {
257         if (!(fsp->state & FC_SRB_COMPL)) {
258                 mod_timer(&fsp->timer, jiffies + delay);
259                 fsp->timer_delay = delay;
260         }
261 }
262
263 static void fc_fcp_abort_done(struct fc_fcp_pkt *fsp)
264 {
265         fsp->state |= FC_SRB_ABORTED;
266         fsp->state &= ~FC_SRB_ABORT_PENDING;
267
268         if (fsp->wait_for_comp)
269                 complete(&fsp->tm_done);
270         else
271                 fc_fcp_complete_locked(fsp);
272 }
273
274 /**
275  * fc_fcp_send_abort() - Send an abort for exchanges associated with a
276  *                       fcp_pkt
277  * @fsp: The FCP packet to abort exchanges on
278  */
279 static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
280 {
281         int rc;
282
283         if (!fsp->seq_ptr)
284                 return -EINVAL;
285
286         per_cpu_ptr(fsp->lp->stats, get_cpu())->FcpPktAborts++;
287         put_cpu();
288
289         fsp->state |= FC_SRB_ABORT_PENDING;
290         rc = fc_seq_exch_abort(fsp->seq_ptr, 0);
291         /*
292          * fc_seq_exch_abort() might return -ENXIO if
293          * the sequence is already completed
294          */
295         if (rc == -ENXIO) {
296                 fc_fcp_abort_done(fsp);
297                 rc = 0;
298         }
299         return rc;
300 }
301
302 /**
303  * fc_fcp_retry_cmd() - Retry a fcp_pkt
304  * @fsp: The FCP packet to be retried
305  *
306  * Sets the status code to be FC_ERROR and then calls
307  * fc_fcp_complete_locked() which in turn calls fc_io_compl().
308  * fc_io_compl() will notify the SCSI-ml that the I/O is done.
309  * The SCSI-ml will retry the command.
310  */
311 static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp, int status_code)
312 {
313         if (fsp->seq_ptr) {
314                 fc_exch_done(fsp->seq_ptr);
315                 fsp->seq_ptr = NULL;
316         }
317
318         fsp->state &= ~FC_SRB_ABORT_PENDING;
319         fsp->io_status = 0;
320         fsp->status_code = status_code;
321         fc_fcp_complete_locked(fsp);
322 }
323
324 /**
325  * fc_fcp_ddp_setup() - Calls a LLD's ddp_setup routine to set up DDP context
326  * @fsp: The FCP packet that will manage the DDP frames
327  * @xid: The XID that will be used for the DDP exchange
328  */
329 void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
330 {
331         struct fc_lport *lport;
332
333         lport = fsp->lp;
334         if ((fsp->req_flags & FC_SRB_READ) &&
335             (lport->lro_enabled) && (lport->tt.ddp_setup)) {
336                 if (lport->tt.ddp_setup(lport, xid, scsi_sglist(fsp->cmd),
337                                         scsi_sg_count(fsp->cmd)))
338                         fsp->xfer_ddp = xid;
339         }
340 }
341
342 /**
343  * fc_fcp_ddp_done() - Calls a LLD's ddp_done routine to release any
344  *                     DDP related resources for a fcp_pkt
345  * @fsp: The FCP packet that DDP had been used on
346  */
347 void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
348 {
349         struct fc_lport *lport;
350
351         if (!fsp)
352                 return;
353
354         if (fsp->xfer_ddp == FC_XID_UNKNOWN)
355                 return;
356
357         lport = fsp->lp;
358         if (lport->tt.ddp_done) {
359                 fsp->xfer_len = lport->tt.ddp_done(lport, fsp->xfer_ddp);
360                 fsp->xfer_ddp = FC_XID_UNKNOWN;
361         }
362 }
363
364 /**
365  * fc_fcp_can_queue_ramp_up() - increases can_queue
366  * @lport: lport to ramp up can_queue
367  */
368 static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
369 {
370         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
371         unsigned long flags;
372         int can_queue;
373
374         spin_lock_irqsave(lport->host->host_lock, flags);
375
376         if (si->last_can_queue_ramp_up_time &&
377             (time_before(jiffies, si->last_can_queue_ramp_up_time +
378                          FC_CAN_QUEUE_PERIOD)))
379                 goto unlock;
380
381         if (time_before(jiffies, si->last_can_queue_ramp_down_time +
382                         FC_CAN_QUEUE_PERIOD))
383                 goto unlock;
384
385         si->last_can_queue_ramp_up_time = jiffies;
386
387         can_queue = lport->host->can_queue << 1;
388         if (can_queue >= si->max_can_queue) {
389                 can_queue = si->max_can_queue;
390                 si->last_can_queue_ramp_down_time = 0;
391         }
392         lport->host->can_queue = can_queue;
393         shost_printk(KERN_ERR, lport->host, "libfc: increased "
394                      "can_queue to %d.\n", can_queue);
395
396 unlock:
397         spin_unlock_irqrestore(lport->host->host_lock, flags);
398 }
399
400 /**
401  * fc_fcp_can_queue_ramp_down() - reduces can_queue
402  * @lport: lport to reduce can_queue
403  *
404  * If we are getting memory allocation failures, then we may
405  * be trying to execute too many commands. We let the running
406  * commands complete or timeout, then try again with a reduced
407  * can_queue. Eventually we will hit the point where we run
408  * on all reserved structs.
409  */
410 static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport)
411 {
412         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
413         unsigned long flags;
414         int can_queue;
415
416         spin_lock_irqsave(lport->host->host_lock, flags);
417
418         if (si->last_can_queue_ramp_down_time &&
419             (time_before(jiffies, si->last_can_queue_ramp_down_time +
420                          FC_CAN_QUEUE_PERIOD)))
421                 goto unlock;
422
423         si->last_can_queue_ramp_down_time = jiffies;
424
425         can_queue = lport->host->can_queue;
426         can_queue >>= 1;
427         if (!can_queue)
428                 can_queue = 1;
429         lport->host->can_queue = can_queue;
430
431 unlock:
432         spin_unlock_irqrestore(lport->host->host_lock, flags);
433 }
434
435 /*
436  * fc_fcp_frame_alloc() -  Allocates fc_frame structure and buffer.
437  * @lport:      fc lport struct
438  * @len:        payload length
439  *
440  * Allocates fc_frame structure and buffer but if fails to allocate
441  * then reduce can_queue.
442  */
443 static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport,
444                                                   size_t len)
445 {
446         struct fc_frame *fp;
447
448         fp = fc_frame_alloc(lport, len);
449         if (likely(fp))
450                 return fp;
451
452         per_cpu_ptr(lport->stats, get_cpu())->FcpFrameAllocFails++;
453         put_cpu();
454         /* error case */
455         fc_fcp_can_queue_ramp_down(lport);
456         shost_printk(KERN_ERR, lport->host,
457                      "libfc: Could not allocate frame, "
458                      "reducing can_queue to %d.\n", lport->host->can_queue);
459         return NULL;
460 }
461
462 /**
463  * get_fsp_rec_tov() - Helper function to get REC_TOV
464  * @fsp: the FCP packet
465  *
466  * Returns rec tov in jiffies as rpriv->e_d_tov + 1 second
467  */
468 static inline unsigned int get_fsp_rec_tov(struct fc_fcp_pkt *fsp)
469 {
470         struct fc_rport_libfc_priv *rpriv = fsp->rport->dd_data;
471         unsigned int e_d_tov = FC_DEF_E_D_TOV;
472
473         if (rpriv && rpriv->e_d_tov > e_d_tov)
474                 e_d_tov = rpriv->e_d_tov;
475         return msecs_to_jiffies(e_d_tov) + HZ;
476 }
477
478 /**
479  * fc_fcp_recv_data() - Handler for receiving SCSI-FCP data from a target
480  * @fsp: The FCP packet the data is on
481  * @fp:  The data frame
482  */
483 static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
484 {
485         struct scsi_cmnd *sc = fsp->cmd;
486         struct fc_lport *lport = fsp->lp;
487         struct fc_stats *stats;
488         struct fc_frame_header *fh;
489         size_t start_offset;
490         size_t offset;
491         u32 crc;
492         u32 copy_len = 0;
493         size_t len;
494         void *buf;
495         struct scatterlist *sg;
496         u32 nents;
497         u8 host_bcode = FC_COMPLETE;
498
499         fh = fc_frame_header_get(fp);
500         offset = ntohl(fh->fh_parm_offset);
501         start_offset = offset;
502         len = fr_len(fp) - sizeof(*fh);
503         buf = fc_frame_payload_get(fp, 0);
504
505         /*
506          * if this I/O is ddped then clear it and initiate recovery since data
507          * frames are expected to be placed directly in that case.
508          *
509          * Indicate error to scsi-ml because something went wrong with the
510          * ddp handling to get us here.
511          */
512         if (fsp->xfer_ddp != FC_XID_UNKNOWN) {
513                 fc_fcp_ddp_done(fsp);
514                 FC_FCP_DBG(fsp, "DDP I/O in fc_fcp_recv_data set ERROR\n");
515                 host_bcode = FC_ERROR;
516                 goto err;
517         }
518         if (offset + len > fsp->data_len) {
519                 /* this should never happen */
520                 if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
521                     fc_frame_crc_check(fp))
522                         goto crc_err;
523                 FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
524                            "data_len %x\n", len, offset, fsp->data_len);
525
526                 /* Data is corrupted indicate scsi-ml should retry */
527                 host_bcode = FC_DATA_OVRRUN;
528                 goto err;
529         }
530         if (offset != fsp->xfer_len)
531                 fsp->state |= FC_SRB_DISCONTIG;
532
533         sg = scsi_sglist(sc);
534         nents = scsi_sg_count(sc);
535
536         if (!(fr_flags(fp) & FCPHF_CRC_UNCHECKED)) {
537                 copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
538                                                     &offset, NULL);
539         } else {
540                 crc = crc32(~0, (u8 *) fh, sizeof(*fh));
541                 copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
542                                                     &offset, &crc);
543                 buf = fc_frame_payload_get(fp, 0);
544                 if (len % 4)
545                         crc = crc32(crc, buf + len, 4 - (len % 4));
546
547                 if (~crc != le32_to_cpu(fr_crc(fp))) {
548 crc_err:
549                         stats = per_cpu_ptr(lport->stats, get_cpu());
550                         stats->ErrorFrames++;
551                         /* per cpu count, not total count, but OK for limit */
552                         if (stats->InvalidCRCCount++ < FC_MAX_ERROR_CNT)
553                                 printk(KERN_WARNING "libfc: CRC error on data "
554                                        "frame for port (%6.6x)\n",
555                                        lport->port_id);
556                         put_cpu();
557                         /*
558                          * Assume the frame is total garbage.
559                          * We may have copied it over the good part
560                          * of the buffer.
561                          * If so, we need to retry the entire operation.
562                          * Otherwise, ignore it.
563                          */
564                         if (fsp->state & FC_SRB_DISCONTIG) {
565                                 host_bcode = FC_CRC_ERROR;
566                                 goto err;
567                         }
568                         return;
569                 }
570         }
571
572         if (fsp->xfer_contig_end == start_offset)
573                 fsp->xfer_contig_end += copy_len;
574         fsp->xfer_len += copy_len;
575
576         /*
577          * In the very rare event that this data arrived after the response
578          * and completes the transfer, call the completion handler.
579          */
580         if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
581             fsp->xfer_len == fsp->data_len - fsp->scsi_resid) {
582                 FC_FCP_DBG( fsp, "complete out-of-order sequence\n" );
583                 fc_fcp_complete_locked(fsp);
584         }
585         return;
586 err:
587         fc_fcp_recovery(fsp, host_bcode);
588 }
589
590 /**
591  * fc_fcp_send_data() - Send SCSI data to a target
592  * @fsp:      The FCP packet the data is on
593  * @sp:       The sequence the data is to be sent on
594  * @offset:   The starting offset for this data request
595  * @seq_blen: The burst length for this data request
596  *
597  * Called after receiving a Transfer Ready data descriptor.
598  * If the LLD is capable of sequence offload then send down the
599  * seq_blen amount of data in single frame, otherwise send
600  * multiple frames of the maximum frame payload supported by
601  * the target port.
602  */
603 static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
604                             size_t offset, size_t seq_blen)
605 {
606         struct fc_exch *ep;
607         struct scsi_cmnd *sc;
608         struct scatterlist *sg;
609         struct fc_frame *fp = NULL;
610         struct fc_lport *lport = fsp->lp;
611         struct page *page;
612         size_t remaining;
613         size_t t_blen;
614         size_t tlen;
615         size_t sg_bytes;
616         size_t frame_offset, fh_parm_offset;
617         size_t off;
618         int error;
619         void *data = NULL;
620         void *page_addr;
621         int using_sg = lport->sg_supp;
622         u32 f_ctl;
623
624         WARN_ON(seq_blen <= 0);
625         if (unlikely(offset + seq_blen > fsp->data_len)) {
626                 /* this should never happen */
627                 FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
628                            "offset %zx\n", seq_blen, offset);
629                 fc_fcp_send_abort(fsp);
630                 return 0;
631         } else if (offset != fsp->xfer_len) {
632                 /* Out of Order Data Request - no problem, but unexpected. */
633                 FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
634                            "seq_blen %zx offset %zx\n", seq_blen, offset);
635         }
636
637         /*
638          * if LLD is capable of seq_offload then set transport
639          * burst length (t_blen) to seq_blen, otherwise set t_blen
640          * to max FC frame payload previously set in fsp->max_payload.
641          */
642         t_blen = fsp->max_payload;
643         if (lport->seq_offload) {
644                 t_blen = min(seq_blen, (size_t)lport->lso_max);
645                 FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
646                            fsp, seq_blen, lport->lso_max, t_blen);
647         }
648
649         if (t_blen > 512)
650                 t_blen &= ~(512 - 1);   /* round down to block size */
651         sc = fsp->cmd;
652
653         remaining = seq_blen;
654         fh_parm_offset = frame_offset = offset;
655         tlen = 0;
656         seq = fc_seq_start_next(seq);
657         f_ctl = FC_FC_REL_OFF;
658         WARN_ON(!seq);
659
660         sg = scsi_sglist(sc);
661
662         while (remaining > 0 && sg) {
663                 if (offset >= sg->length) {
664                         offset -= sg->length;
665                         sg = sg_next(sg);
666                         continue;
667                 }
668                 if (!fp) {
669                         tlen = min(t_blen, remaining);
670
671                         /*
672                          * TODO.  Temporary workaround.  fc_seq_send() can't
673                          * handle odd lengths in non-linear skbs.
674                          * This will be the final fragment only.
675                          */
676                         if (tlen % 4)
677                                 using_sg = 0;
678                         fp = fc_frame_alloc(lport, using_sg ? 0 : tlen);
679                         if (!fp)
680                                 return -ENOMEM;
681
682                         data = fc_frame_header_get(fp) + 1;
683                         fh_parm_offset = frame_offset;
684                         fr_max_payload(fp) = fsp->max_payload;
685                 }
686
687                 off = offset + sg->offset;
688                 sg_bytes = min(tlen, sg->length - offset);
689                 sg_bytes = min(sg_bytes,
690                                (size_t) (PAGE_SIZE - (off & ~PAGE_MASK)));
691                 page = sg_page(sg) + (off >> PAGE_SHIFT);
692                 if (using_sg) {
693                         get_page(page);
694                         skb_fill_page_desc(fp_skb(fp),
695                                            skb_shinfo(fp_skb(fp))->nr_frags,
696                                            page, off & ~PAGE_MASK, sg_bytes);
697                         fp_skb(fp)->data_len += sg_bytes;
698                         fr_len(fp) += sg_bytes;
699                         fp_skb(fp)->truesize += PAGE_SIZE;
700                 } else {
701                         /*
702                          * The scatterlist item may be bigger than PAGE_SIZE,
703                          * but we must not cross pages inside the kmap.
704                          */
705                         page_addr = kmap_atomic(page);
706                         memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
707                                sg_bytes);
708                         kunmap_atomic(page_addr);
709                         data += sg_bytes;
710                 }
711                 offset += sg_bytes;
712                 frame_offset += sg_bytes;
713                 tlen -= sg_bytes;
714                 remaining -= sg_bytes;
715
716                 if ((skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN) &&
717                     (tlen))
718                         continue;
719
720                 /*
721                  * Send sequence with transfer sequence initiative in case
722                  * this is last FCP frame of the sequence.
723                  */
724                 if (remaining == 0)
725                         f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
726
727                 ep = fc_seq_exch(seq);
728                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
729                                FC_TYPE_FCP, f_ctl, fh_parm_offset);
730
731                 /*
732                  * send fragment using for a sequence.
733                  */
734                 error = fc_seq_send(lport, seq, fp);
735                 if (error) {
736                         WARN_ON(1);             /* send error should be rare */
737                         return error;
738                 }
739                 fp = NULL;
740         }
741         fsp->xfer_len += seq_blen;      /* premature count? */
742         return 0;
743 }
744
745 /**
746  * fc_fcp_abts_resp() - Receive an ABTS response
747  * @fsp: The FCP packet that is being aborted
748  * @fp:  The response frame
749  */
750 static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
751 {
752         int ba_done = 1;
753         struct fc_ba_rjt *brp;
754         struct fc_frame_header *fh;
755
756         fh = fc_frame_header_get(fp);
757         switch (fh->fh_r_ctl) {
758         case FC_RCTL_BA_ACC:
759                 break;
760         case FC_RCTL_BA_RJT:
761                 brp = fc_frame_payload_get(fp, sizeof(*brp));
762                 if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
763                         break;
764                 /* fall thru */
765         default:
766                 /*
767                  * we will let the command timeout
768                  * and scsi-ml recover in this case,
769                  * therefore cleared the ba_done flag.
770                  */
771                 ba_done = 0;
772         }
773
774         if (ba_done)
775                 fc_fcp_abort_done(fsp);
776 }
777
778 /**
779  * fc_fcp_recv() - Receive an FCP frame
780  * @seq: The sequence the frame is on
781  * @fp:  The received frame
782  * @arg: The related FCP packet
783  *
784  * Context: Called from Soft IRQ context. Can not be called
785  *          holding the FCP packet list lock.
786  */
787 static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
788 {
789         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
790         struct fc_lport *lport = fsp->lp;
791         struct fc_frame_header *fh;
792         struct fcp_txrdy *dd;
793         u8 r_ctl;
794         int rc = 0;
795
796         if (IS_ERR(fp)) {
797                 fc_fcp_error(fsp, fp);
798                 return;
799         }
800
801         fh = fc_frame_header_get(fp);
802         r_ctl = fh->fh_r_ctl;
803
804         if (lport->state != LPORT_ST_READY) {
805                 FC_FCP_DBG(fsp, "lport state %d, ignoring r_ctl %x\n",
806                            lport->state, r_ctl);
807                 goto out;
808         }
809         if (fc_fcp_lock_pkt(fsp))
810                 goto out;
811
812         if (fh->fh_type == FC_TYPE_BLS) {
813                 fc_fcp_abts_resp(fsp, fp);
814                 goto unlock;
815         }
816
817         if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING)) {
818                 FC_FCP_DBG(fsp, "command aborted, ignoring r_ctl %x\n", r_ctl);
819                 goto unlock;
820         }
821
822         if (r_ctl == FC_RCTL_DD_DATA_DESC) {
823                 /*
824                  * received XFER RDY from the target
825                  * need to send data to the target
826                  */
827                 WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
828                 dd = fc_frame_payload_get(fp, sizeof(*dd));
829                 WARN_ON(!dd);
830
831                 rc = fc_fcp_send_data(fsp, seq,
832                                       (size_t) ntohl(dd->ft_data_ro),
833                                       (size_t) ntohl(dd->ft_burst_len));
834                 if (!rc)
835                         seq->rec_data = fsp->xfer_len;
836         } else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
837                 /*
838                  * received a DATA frame
839                  * next we will copy the data to the system buffer
840                  */
841                 WARN_ON(fr_len(fp) < sizeof(*fh));      /* len may be 0 */
842                 fc_fcp_recv_data(fsp, fp);
843                 seq->rec_data = fsp->xfer_contig_end;
844         } else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
845                 WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
846
847                 fc_fcp_resp(fsp, fp);
848         } else {
849                 FC_FCP_DBG(fsp, "unexpected frame.  r_ctl %x\n", r_ctl);
850         }
851 unlock:
852         fc_fcp_unlock_pkt(fsp);
853 out:
854         fc_frame_free(fp);
855 }
856
857 /**
858  * fc_fcp_resp() - Handler for FCP responses
859  * @fsp: The FCP packet the response is for
860  * @fp:  The response frame
861  */
862 static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
863 {
864         struct fc_frame_header *fh;
865         struct fcp_resp *fc_rp;
866         struct fcp_resp_ext *rp_ex;
867         struct fcp_resp_rsp_info *fc_rp_info;
868         u32 plen;
869         u32 expected_len;
870         u32 respl = 0;
871         u32 snsl = 0;
872         u8 flags = 0;
873
874         plen = fr_len(fp);
875         fh = (struct fc_frame_header *)fr_hdr(fp);
876         if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
877                 goto len_err;
878         plen -= sizeof(*fh);
879         fc_rp = (struct fcp_resp *)(fh + 1);
880         fsp->cdb_status = fc_rp->fr_status;
881         flags = fc_rp->fr_flags;
882         fsp->scsi_comp_flags = flags;
883         expected_len = fsp->data_len;
884
885         /* if ddp, update xfer len */
886         fc_fcp_ddp_done(fsp);
887
888         if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
889                 rp_ex = (void *)(fc_rp + 1);
890                 if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
891                         if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
892                                 goto len_err;
893                         fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
894                         if (flags & FCP_RSP_LEN_VAL) {
895                                 respl = ntohl(rp_ex->fr_rsp_len);
896                                 if ((respl != FCP_RESP_RSP_INFO_LEN4) &&
897                                     (respl != FCP_RESP_RSP_INFO_LEN8))
898                                         goto len_err;
899                                 if (fsp->wait_for_comp) {
900                                         /* Abuse cdb_status for rsp code */
901                                         fsp->cdb_status = fc_rp_info->rsp_code;
902                                         complete(&fsp->tm_done);
903                                         /*
904                                          * tmfs will not have any scsi cmd so
905                                          * exit here
906                                          */
907                                         return;
908                                 }
909                         }
910                         if (flags & FCP_SNS_LEN_VAL) {
911                                 snsl = ntohl(rp_ex->fr_sns_len);
912                                 if (snsl > SCSI_SENSE_BUFFERSIZE)
913                                         snsl = SCSI_SENSE_BUFFERSIZE;
914                                 memcpy(fsp->cmd->sense_buffer,
915                                        (char *)fc_rp_info + respl, snsl);
916                         }
917                 }
918                 if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
919                         if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
920                                 goto len_err;
921                         if (flags & FCP_RESID_UNDER) {
922                                 fsp->scsi_resid = ntohl(rp_ex->fr_resid);
923                                 /*
924                                  * The cmnd->underflow is the minimum number of
925                                  * bytes that must be transferred for this
926                                  * command.  Provided a sense condition is not
927                                  * present, make sure the actual amount
928                                  * transferred is at least the underflow value
929                                  * or fail.
930                                  */
931                                 if (!(flags & FCP_SNS_LEN_VAL) &&
932                                     (fc_rp->fr_status == 0) &&
933                                     (scsi_bufflen(fsp->cmd) -
934                                      fsp->scsi_resid) < fsp->cmd->underflow)
935                                         goto err;
936                                 expected_len -= fsp->scsi_resid;
937                         } else {
938                                 fsp->status_code = FC_ERROR;
939                         }
940                 }
941         }
942         fsp->state |= FC_SRB_RCV_STATUS;
943
944         /*
945          * Check for missing or extra data frames.
946          */
947         if (unlikely(fsp->cdb_status == SAM_STAT_GOOD &&
948                      fsp->xfer_len != expected_len)) {
949                 if (fsp->xfer_len < expected_len) {
950                         /*
951                          * Some data may be queued locally,
952                          * Wait a at least one jiffy to see if it is delivered.
953                          * If this expires without data, we may do SRR.
954                          */
955                         if (fsp->lp->qfull) {
956                                 FC_FCP_DBG(fsp, "tgt %6.6x queue busy retry\n",
957                                            fsp->rport->port_id);
958                                 return;
959                         }
960                         FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx data underrun "
961                                    "len %x, data len %x\n",
962                                    fsp->rport->port_id,
963                                    fsp->xfer_len, expected_len, fsp->data_len);
964                         fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
965                         return;
966                 }
967                 fsp->status_code = FC_DATA_OVRRUN;
968                 FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx greater than expected, "
969                            "len %x, data len %x\n",
970                            fsp->rport->port_id,
971                            fsp->xfer_len, expected_len, fsp->data_len);
972         }
973         fc_fcp_complete_locked(fsp);
974         return;
975
976 len_err:
977         FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
978                    "snsl %u\n", flags, fr_len(fp), respl, snsl);
979 err:
980         fsp->status_code = FC_ERROR;
981         fc_fcp_complete_locked(fsp);
982 }
983
984 /**
985  * fc_fcp_complete_locked() - Complete processing of a fcp_pkt with the
986  *                            fcp_pkt lock held
987  * @fsp: The FCP packet to be completed
988  *
989  * This function may sleep if a timer is pending. The packet lock must be
990  * held, and the host lock must not be held.
991  */
992 static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
993 {
994         struct fc_lport *lport = fsp->lp;
995         struct fc_seq *seq;
996         struct fc_exch *ep;
997         u32 f_ctl;
998
999         if (fsp->state & FC_SRB_ABORT_PENDING)
1000                 return;
1001
1002         if (fsp->state & FC_SRB_ABORTED) {
1003                 if (!fsp->status_code)
1004                         fsp->status_code = FC_CMD_ABORTED;
1005         } else {
1006                 /*
1007                  * Test for transport underrun, independent of response
1008                  * underrun status.
1009                  */
1010                 if (fsp->cdb_status == SAM_STAT_GOOD &&
1011                     fsp->xfer_len < fsp->data_len && !fsp->io_status &&
1012                     (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
1013                      fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
1014                         FC_FCP_DBG(fsp, "data underrun, xfer %zx data %x\n",
1015                                     fsp->xfer_len, fsp->data_len);
1016                         fsp->status_code = FC_DATA_UNDRUN;
1017                 }
1018         }
1019
1020         seq = fsp->seq_ptr;
1021         if (seq) {
1022                 fsp->seq_ptr = NULL;
1023                 if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
1024                         struct fc_frame *conf_frame;
1025                         struct fc_seq *csp;
1026
1027                         csp = fc_seq_start_next(seq);
1028                         conf_frame = fc_fcp_frame_alloc(fsp->lp, 0);
1029                         if (conf_frame) {
1030                                 f_ctl = FC_FC_SEQ_INIT;
1031                                 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1032                                 ep = fc_seq_exch(seq);
1033                                 fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
1034                                                ep->did, ep->sid,
1035                                                FC_TYPE_FCP, f_ctl, 0);
1036                                 fc_seq_send(lport, csp, conf_frame);
1037                         }
1038                 }
1039                 fc_exch_done(seq);
1040         }
1041         /*
1042          * Some resets driven by SCSI are not I/Os and do not have
1043          * SCSI commands associated with the requests. We should not
1044          * call I/O completion if we do not have a SCSI command.
1045          */
1046         if (fsp->cmd)
1047                 fc_io_compl(fsp);
1048 }
1049
1050 /**
1051  * fc_fcp_cleanup_cmd() - Cancel the active exchange on a fcp_pkt
1052  * @fsp:   The FCP packet whose exchanges should be canceled
1053  * @error: The reason for the cancellation
1054  */
1055 static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
1056 {
1057         if (fsp->seq_ptr) {
1058                 fc_exch_done(fsp->seq_ptr);
1059                 fsp->seq_ptr = NULL;
1060         }
1061         fsp->status_code = error;
1062 }
1063
1064 /**
1065  * fc_fcp_cleanup_each_cmd() - Cancel all exchanges on a local port
1066  * @lport: The local port whose exchanges should be canceled
1067  * @id:    The target's ID
1068  * @lun:   The LUN
1069  * @error: The reason for cancellation
1070  *
1071  * If lun or id is -1, they are ignored.
1072  */
1073 static void fc_fcp_cleanup_each_cmd(struct fc_lport *lport, unsigned int id,
1074                                     unsigned int lun, int error)
1075 {
1076         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1077         struct fc_fcp_pkt *fsp;
1078         struct scsi_cmnd *sc_cmd;
1079         unsigned long flags;
1080
1081         spin_lock_irqsave(&si->scsi_queue_lock, flags);
1082 restart:
1083         list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
1084                 sc_cmd = fsp->cmd;
1085                 if (id != -1 && scmd_id(sc_cmd) != id)
1086                         continue;
1087
1088                 if (lun != -1 && sc_cmd->device->lun != lun)
1089                         continue;
1090
1091                 fc_fcp_pkt_hold(fsp);
1092                 spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1093
1094                 spin_lock_bh(&fsp->scsi_pkt_lock);
1095                 if (!(fsp->state & FC_SRB_COMPL)) {
1096                         fsp->state |= FC_SRB_COMPL;
1097                         /*
1098                          * TODO: dropping scsi_pkt_lock and then reacquiring
1099                          * again around fc_fcp_cleanup_cmd() is required,
1100                          * since fc_fcp_cleanup_cmd() calls into
1101                          * fc_seq_set_resp() and that func preempts cpu using
1102                          * schedule. May be schedule and related code should be
1103                          * removed instead of unlocking here to avoid scheduling
1104                          * while atomic bug.
1105                          */
1106                         spin_unlock_bh(&fsp->scsi_pkt_lock);
1107
1108                         fc_fcp_cleanup_cmd(fsp, error);
1109
1110                         spin_lock_bh(&fsp->scsi_pkt_lock);
1111                         fc_io_compl(fsp);
1112                 }
1113                 spin_unlock_bh(&fsp->scsi_pkt_lock);
1114
1115                 fc_fcp_pkt_release(fsp);
1116                 spin_lock_irqsave(&si->scsi_queue_lock, flags);
1117                 /*
1118                  * while we dropped the lock multiple pkts could
1119                  * have been released, so we have to start over.
1120                  */
1121                 goto restart;
1122         }
1123         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1124 }
1125
1126 /**
1127  * fc_fcp_abort_io() - Abort all FCP-SCSI exchanges on a local port
1128  * @lport: The local port whose exchanges are to be aborted
1129  */
1130 static void fc_fcp_abort_io(struct fc_lport *lport)
1131 {
1132         fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_HRD_ERROR);
1133 }
1134
1135 /**
1136  * fc_fcp_pkt_send() - Send a fcp_pkt
1137  * @lport: The local port to send the FCP packet on
1138  * @fsp:   The FCP packet to send
1139  *
1140  * Return:  Zero for success and -1 for failure
1141  * Locks:   Called without locks held
1142  */
1143 static int fc_fcp_pkt_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp)
1144 {
1145         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
1146         unsigned long flags;
1147         int rc;
1148
1149         fsp->cmd->SCp.ptr = (char *)fsp;
1150         fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1151         fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
1152
1153         int_to_scsilun(fsp->cmd->device->lun, &fsp->cdb_cmd.fc_lun);
1154         memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
1155
1156         spin_lock_irqsave(&si->scsi_queue_lock, flags);
1157         list_add_tail(&fsp->list, &si->scsi_pkt_queue);
1158         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1159         rc = lport->tt.fcp_cmd_send(lport, fsp, fc_fcp_recv);
1160         if (unlikely(rc)) {
1161                 spin_lock_irqsave(&si->scsi_queue_lock, flags);
1162                 fsp->cmd->SCp.ptr = NULL;
1163                 list_del(&fsp->list);
1164                 spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
1165         }
1166
1167         return rc;
1168 }
1169
1170 /**
1171  * fc_fcp_cmd_send() - Send a FCP command
1172  * @lport: The local port to send the command on
1173  * @fsp:   The FCP packet the command is on
1174  * @resp:  The handler for the response
1175  */
1176 static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1177                            void (*resp)(struct fc_seq *,
1178                                         struct fc_frame *fp,
1179                                         void *arg))
1180 {
1181         struct fc_frame *fp;
1182         struct fc_seq *seq;
1183         struct fc_rport *rport;
1184         struct fc_rport_libfc_priv *rpriv;
1185         const size_t len = sizeof(fsp->cdb_cmd);
1186         int rc = 0;
1187
1188         if (fc_fcp_lock_pkt(fsp))
1189                 return 0;
1190
1191         fp = fc_fcp_frame_alloc(lport, sizeof(fsp->cdb_cmd));
1192         if (!fp) {
1193                 rc = -1;
1194                 goto unlock;
1195         }
1196
1197         memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
1198         fr_fsp(fp) = fsp;
1199         rport = fsp->rport;
1200         fsp->max_payload = rport->maxframe_size;
1201         rpriv = rport->dd_data;
1202
1203         fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
1204                        rpriv->local_port->port_id, FC_TYPE_FCP,
1205                        FC_FCTL_REQ, 0);
1206
1207         seq = fc_exch_seq_send(lport, fp, resp, fc_fcp_pkt_destroy, fsp, 0);
1208         if (!seq) {
1209                 rc = -1;
1210                 goto unlock;
1211         }
1212         fsp->seq_ptr = seq;
1213         fc_fcp_pkt_hold(fsp);   /* hold for fc_fcp_pkt_destroy */
1214
1215         setup_timer(&fsp->timer, fc_fcp_timeout, (unsigned long)fsp);
1216         if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1217                 fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1218
1219 unlock:
1220         fc_fcp_unlock_pkt(fsp);
1221         return rc;
1222 }
1223
1224 /**
1225  * fc_fcp_error() - Handler for FCP layer errors
1226  * @fsp: The FCP packet the error is on
1227  * @fp:  The frame that has errored
1228  */
1229 static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1230 {
1231         int error = PTR_ERR(fp);
1232
1233         if (fc_fcp_lock_pkt(fsp))
1234                 return;
1235
1236         if (error == -FC_EX_CLOSED) {
1237                 fc_fcp_retry_cmd(fsp, FC_ERROR);
1238                 goto unlock;
1239         }
1240
1241         /*
1242          * clear abort pending, because the lower layer
1243          * decided to force completion.
1244          */
1245         fsp->state &= ~FC_SRB_ABORT_PENDING;
1246         fsp->status_code = FC_CMD_PLOGO;
1247         fc_fcp_complete_locked(fsp);
1248 unlock:
1249         fc_fcp_unlock_pkt(fsp);
1250 }
1251
1252 /**
1253  * fc_fcp_pkt_abort() - Abort a fcp_pkt
1254  * @fsp:   The FCP packet to abort on
1255  *
1256  * Called to send an abort and then wait for abort completion
1257  */
1258 static int fc_fcp_pkt_abort(struct fc_fcp_pkt *fsp)
1259 {
1260         int rc = FAILED;
1261         unsigned long ticks_left;
1262
1263         FC_FCP_DBG(fsp, "pkt abort state %x\n", fsp->state);
1264         if (fc_fcp_send_abort(fsp)) {
1265                 FC_FCP_DBG(fsp, "failed to send abort\n");
1266                 return FAILED;
1267         }
1268
1269         if (fsp->state & FC_SRB_ABORTED) {
1270                 FC_FCP_DBG(fsp, "target abort cmd  completed\n");
1271                 return SUCCESS;
1272         }
1273
1274         init_completion(&fsp->tm_done);
1275         fsp->wait_for_comp = 1;
1276
1277         spin_unlock_bh(&fsp->scsi_pkt_lock);
1278         ticks_left = wait_for_completion_timeout(&fsp->tm_done,
1279                                                         FC_SCSI_TM_TOV);
1280         spin_lock_bh(&fsp->scsi_pkt_lock);
1281         fsp->wait_for_comp = 0;
1282
1283         if (!ticks_left) {
1284                 FC_FCP_DBG(fsp, "target abort cmd  failed\n");
1285         } else if (fsp->state & FC_SRB_ABORTED) {
1286                 FC_FCP_DBG(fsp, "target abort cmd  passed\n");
1287                 rc = SUCCESS;
1288                 fc_fcp_complete_locked(fsp);
1289         }
1290
1291         return rc;
1292 }
1293
1294 /**
1295  * fc_lun_reset_send() - Send LUN reset command
1296  * @data: The FCP packet that identifies the LUN to be reset
1297  */
1298 static void fc_lun_reset_send(unsigned long data)
1299 {
1300         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1301         struct fc_lport *lport = fsp->lp;
1302
1303         if (lport->tt.fcp_cmd_send(lport, fsp, fc_tm_done)) {
1304                 if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
1305                         return;
1306                 if (fc_fcp_lock_pkt(fsp))
1307                         return;
1308                 setup_timer(&fsp->timer, fc_lun_reset_send, (unsigned long)fsp);
1309                 fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1310                 fc_fcp_unlock_pkt(fsp);
1311         }
1312 }
1313
1314 /**
1315  * fc_lun_reset() - Send a LUN RESET command to a device
1316  *                  and wait for the reply
1317  * @lport: The local port to sent the command on
1318  * @fsp:   The FCP packet that identifies the LUN to be reset
1319  * @id:    The SCSI command ID
1320  * @lun:   The LUN ID to be reset
1321  */
1322 static int fc_lun_reset(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
1323                         unsigned int id, unsigned int lun)
1324 {
1325         int rc;
1326
1327         fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
1328         fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
1329         int_to_scsilun(lun, &fsp->cdb_cmd.fc_lun);
1330
1331         fsp->wait_for_comp = 1;
1332         init_completion(&fsp->tm_done);
1333
1334         fc_lun_reset_send((unsigned long)fsp);
1335
1336         /*
1337          * wait for completion of reset
1338          * after that make sure all commands are terminated
1339          */
1340         rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
1341
1342         spin_lock_bh(&fsp->scsi_pkt_lock);
1343         fsp->state |= FC_SRB_COMPL;
1344         spin_unlock_bh(&fsp->scsi_pkt_lock);
1345
1346         del_timer_sync(&fsp->timer);
1347
1348         spin_lock_bh(&fsp->scsi_pkt_lock);
1349         if (fsp->seq_ptr) {
1350                 fc_exch_done(fsp->seq_ptr);
1351                 fsp->seq_ptr = NULL;
1352         }
1353         fsp->wait_for_comp = 0;
1354         spin_unlock_bh(&fsp->scsi_pkt_lock);
1355
1356         if (!rc) {
1357                 FC_SCSI_DBG(lport, "lun reset failed\n");
1358                 return FAILED;
1359         }
1360
1361         /* cdb_status holds the tmf's rsp code */
1362         if (fsp->cdb_status != FCP_TMF_CMPL)
1363                 return FAILED;
1364
1365         FC_SCSI_DBG(lport, "lun reset to lun %u completed\n", lun);
1366         fc_fcp_cleanup_each_cmd(lport, id, lun, FC_CMD_ABORTED);
1367         return SUCCESS;
1368 }
1369
1370 /**
1371  * fc_tm_done() - Task Management response handler
1372  * @seq: The sequence that the response is on
1373  * @fp:  The response frame
1374  * @arg: The FCP packet the response is for
1375  */
1376 static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1377 {
1378         struct fc_fcp_pkt *fsp = arg;
1379         struct fc_frame_header *fh;
1380
1381         if (IS_ERR(fp)) {
1382                 /*
1383                  * If there is an error just let it timeout or wait
1384                  * for TMF to be aborted if it timedout.
1385                  *
1386                  * scsi-eh will escalate for when either happens.
1387                  */
1388                 return;
1389         }
1390
1391         if (fc_fcp_lock_pkt(fsp))
1392                 goto out;
1393
1394         /*
1395          * raced with eh timeout handler.
1396          */
1397         if (!fsp->seq_ptr || !fsp->wait_for_comp)
1398                 goto out_unlock;
1399
1400         fh = fc_frame_header_get(fp);
1401         if (fh->fh_type != FC_TYPE_BLS)
1402                 fc_fcp_resp(fsp, fp);
1403         fsp->seq_ptr = NULL;
1404         fc_exch_done(seq);
1405 out_unlock:
1406         fc_fcp_unlock_pkt(fsp);
1407 out:
1408         fc_frame_free(fp);
1409 }
1410
1411 /**
1412  * fc_fcp_cleanup() - Cleanup all FCP exchanges on a local port
1413  * @lport: The local port to be cleaned up
1414  */
1415 static void fc_fcp_cleanup(struct fc_lport *lport)
1416 {
1417         fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_ERROR);
1418 }
1419
1420 /**
1421  * fc_fcp_timeout() - Handler for fcp_pkt timeouts
1422  * @data: The FCP packet that has timed out
1423  *
1424  * If REC is supported then just issue it and return. The REC exchange will
1425  * complete or time out and recovery can continue at that point. Otherwise,
1426  * if the response has been received without all the data it has been
1427  * ER_TIMEOUT since the response was received. If the response has not been
1428  * received we see if data was received recently. If it has been then we
1429  * continue waiting, otherwise, we abort the command.
1430  */
1431 static void fc_fcp_timeout(unsigned long data)
1432 {
1433         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
1434         struct fc_rport *rport = fsp->rport;
1435         struct fc_rport_libfc_priv *rpriv = rport->dd_data;
1436
1437         if (fc_fcp_lock_pkt(fsp))
1438                 return;
1439
1440         if (fsp->cdb_cmd.fc_tm_flags)
1441                 goto unlock;
1442
1443         if (fsp->lp->qfull) {
1444                 FC_FCP_DBG(fsp, "fcp timeout, resetting timer delay %d\n",
1445                            fsp->timer_delay);
1446                 setup_timer(&fsp->timer, fc_fcp_timeout, (unsigned long)fsp);
1447                 fc_fcp_timer_set(fsp, fsp->timer_delay);
1448                 goto unlock;
1449         }
1450         FC_FCP_DBG(fsp, "fcp timeout, delay %d flags %x state %x\n",
1451                    fsp->timer_delay, rpriv->flags, fsp->state);
1452         fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
1453
1454         if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
1455                 fc_fcp_rec(fsp);
1456         else if (fsp->state & FC_SRB_RCV_STATUS)
1457                 fc_fcp_complete_locked(fsp);
1458         else
1459                 fc_fcp_recovery(fsp, FC_TIMED_OUT);
1460         fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
1461 unlock:
1462         fc_fcp_unlock_pkt(fsp);
1463 }
1464
1465 /**
1466  * fc_fcp_rec() - Send a REC ELS request
1467  * @fsp: The FCP packet to send the REC request on
1468  */
1469 static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
1470 {
1471         struct fc_lport *lport;
1472         struct fc_frame *fp;
1473         struct fc_rport *rport;
1474         struct fc_rport_libfc_priv *rpriv;
1475
1476         lport = fsp->lp;
1477         rport = fsp->rport;
1478         rpriv = rport->dd_data;
1479         if (!fsp->seq_ptr || rpriv->rp_state != RPORT_ST_READY) {
1480                 fsp->status_code = FC_HRD_ERROR;
1481                 fsp->io_status = 0;
1482                 fc_fcp_complete_locked(fsp);
1483                 return;
1484         }
1485
1486         fp = fc_fcp_frame_alloc(lport, sizeof(struct fc_els_rec));
1487         if (!fp)
1488                 goto retry;
1489
1490         fr_seq(fp) = fsp->seq_ptr;
1491         fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
1492                        rpriv->local_port->port_id, FC_TYPE_ELS,
1493                        FC_FCTL_REQ, 0);
1494         if (lport->tt.elsct_send(lport, rport->port_id, fp, ELS_REC,
1495                                  fc_fcp_rec_resp, fsp,
1496                                  2 * lport->r_a_tov)) {
1497                 fc_fcp_pkt_hold(fsp);           /* hold while REC outstanding */
1498                 return;
1499         }
1500 retry:
1501         if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1502                 fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1503         else
1504                 fc_fcp_recovery(fsp, FC_TIMED_OUT);
1505 }
1506
1507 /**
1508  * fc_fcp_rec_resp() - Handler for REC ELS responses
1509  * @seq: The sequence the response is on
1510  * @fp:  The response frame
1511  * @arg: The FCP packet the response is on
1512  *
1513  * If the response is a reject then the scsi layer will handle
1514  * the timeout. If the response is a LS_ACC then if the I/O was not completed
1515  * set the timeout and return. If the I/O was completed then complete the
1516  * exchange and tell the SCSI layer.
1517  */
1518 static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1519 {
1520         struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
1521         struct fc_els_rec_acc *recp;
1522         struct fc_els_ls_rjt *rjt;
1523         u32 e_stat;
1524         u8 opcode;
1525         u32 offset;
1526         enum dma_data_direction data_dir;
1527         enum fc_rctl r_ctl;
1528         struct fc_rport_libfc_priv *rpriv;
1529
1530         if (IS_ERR(fp)) {
1531                 fc_fcp_rec_error(fsp, fp);
1532                 return;
1533         }
1534
1535         if (fc_fcp_lock_pkt(fsp))
1536                 goto out;
1537
1538         fsp->recov_retry = 0;
1539         opcode = fc_frame_payload_op(fp);
1540         if (opcode == ELS_LS_RJT) {
1541                 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1542                 switch (rjt->er_reason) {
1543                 default:
1544                         FC_FCP_DBG(fsp,
1545                                    "device %x invalid REC reject %d/%d\n",
1546                                    fsp->rport->port_id, rjt->er_reason,
1547                                    rjt->er_explan);
1548                         /* fall through */
1549                 case ELS_RJT_UNSUP:
1550                         FC_FCP_DBG(fsp, "device does not support REC\n");
1551                         rpriv = fsp->rport->dd_data;
1552                         /*
1553                          * if we do not spport RECs or got some bogus
1554                          * reason then resetup timer so we check for
1555                          * making progress.
1556                          */
1557                         rpriv->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
1558                         break;
1559                 case ELS_RJT_LOGIC:
1560                 case ELS_RJT_UNAB:
1561                         FC_FCP_DBG(fsp, "device %x REC reject %d/%d\n",
1562                                    fsp->rport->port_id, rjt->er_reason,
1563                                    rjt->er_explan);
1564                         /*
1565                          * If response got lost or is stuck in the
1566                          * queue somewhere we have no idea if and when
1567                          * the response will be received. So quarantine
1568                          * the xid and retry the command.
1569                          */
1570                         if (rjt->er_explan == ELS_EXPL_OXID_RXID) {
1571                                 struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1572                                 ep->state |= FC_EX_QUARANTINE;
1573                                 fsp->state |= FC_SRB_ABORTED;
1574                                 fc_fcp_retry_cmd(fsp, FC_TRANS_RESET);
1575                                 break;
1576                         }
1577                         fc_fcp_recovery(fsp, FC_TRANS_RESET);
1578                         break;
1579                 }
1580         } else if (opcode == ELS_LS_ACC) {
1581                 if (fsp->state & FC_SRB_ABORTED)
1582                         goto unlock_out;
1583
1584                 data_dir = fsp->cmd->sc_data_direction;
1585                 recp = fc_frame_payload_get(fp, sizeof(*recp));
1586                 offset = ntohl(recp->reca_fc4value);
1587                 e_stat = ntohl(recp->reca_e_stat);
1588
1589                 if (e_stat & ESB_ST_COMPLETE) {
1590
1591                         /*
1592                          * The exchange is complete.
1593                          *
1594                          * For output, we must've lost the response.
1595                          * For input, all data must've been sent.
1596                          * We lost may have lost the response
1597                          * (and a confirmation was requested) and maybe
1598                          * some data.
1599                          *
1600                          * If all data received, send SRR
1601                          * asking for response.  If partial data received,
1602                          * or gaps, SRR requests data at start of gap.
1603                          * Recovery via SRR relies on in-order-delivery.
1604                          */
1605                         if (data_dir == DMA_TO_DEVICE) {
1606                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1607                         } else if (fsp->xfer_contig_end == offset) {
1608                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1609                         } else {
1610                                 offset = fsp->xfer_contig_end;
1611                                 r_ctl = FC_RCTL_DD_SOL_DATA;
1612                         }
1613                         fc_fcp_srr(fsp, r_ctl, offset);
1614                 } else if (e_stat & ESB_ST_SEQ_INIT) {
1615                         /*
1616                          * The remote port has the initiative, so just
1617                          * keep waiting for it to complete.
1618                          */
1619                         fc_fcp_timer_set(fsp,  get_fsp_rec_tov(fsp));
1620                 } else {
1621
1622                         /*
1623                          * The exchange is incomplete, we have seq. initiative.
1624                          * Lost response with requested confirmation,
1625                          * lost confirmation, lost transfer ready or
1626                          * lost write data.
1627                          *
1628                          * For output, if not all data was received, ask
1629                          * for transfer ready to be repeated.
1630                          *
1631                          * If we received or sent all the data, send SRR to
1632                          * request response.
1633                          *
1634                          * If we lost a response, we may have lost some read
1635                          * data as well.
1636                          */
1637                         r_ctl = FC_RCTL_DD_SOL_DATA;
1638                         if (data_dir == DMA_TO_DEVICE) {
1639                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1640                                 if (offset < fsp->data_len)
1641                                         r_ctl = FC_RCTL_DD_DATA_DESC;
1642                         } else if (offset == fsp->xfer_contig_end) {
1643                                 r_ctl = FC_RCTL_DD_CMD_STATUS;
1644                         } else if (fsp->xfer_contig_end < offset) {
1645                                 offset = fsp->xfer_contig_end;
1646                         }
1647                         fc_fcp_srr(fsp, r_ctl, offset);
1648                 }
1649         }
1650 unlock_out:
1651         fc_fcp_unlock_pkt(fsp);
1652 out:
1653         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding REC */
1654         fc_frame_free(fp);
1655 }
1656
1657 /**
1658  * fc_fcp_rec_error() - Handler for REC errors
1659  * @fsp: The FCP packet the error is on
1660  * @fp:  The REC frame
1661  */
1662 static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1663 {
1664         int error = PTR_ERR(fp);
1665
1666         if (fc_fcp_lock_pkt(fsp))
1667                 goto out;
1668
1669         switch (error) {
1670         case -FC_EX_CLOSED:
1671                 FC_FCP_DBG(fsp, "REC %p fid %6.6x exchange closed\n",
1672                            fsp, fsp->rport->port_id);
1673                 fc_fcp_retry_cmd(fsp, FC_ERROR);
1674                 break;
1675
1676         default:
1677                 FC_FCP_DBG(fsp, "REC %p fid %6.6x error unexpected error %d\n",
1678                            fsp, fsp->rport->port_id, error);
1679                 fsp->status_code = FC_CMD_PLOGO;
1680                 /* fall through */
1681
1682         case -FC_EX_TIMEOUT:
1683                 /*
1684                  * Assume REC or LS_ACC was lost.
1685                  * The exchange manager will have aborted REC, so retry.
1686                  */
1687                 FC_FCP_DBG(fsp, "REC %p fid %6.6x exchange timeout retry %d/%d\n",
1688                            fsp, fsp->rport->port_id, fsp->recov_retry,
1689                            FC_MAX_RECOV_RETRY);
1690                 if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1691                         fc_fcp_rec(fsp);
1692                 else
1693                         fc_fcp_recovery(fsp, FC_ERROR);
1694                 break;
1695         }
1696         fc_fcp_unlock_pkt(fsp);
1697 out:
1698         fc_fcp_pkt_release(fsp);        /* drop hold for outstanding REC */
1699 }
1700
1701 /**
1702  * fc_fcp_recovery() - Handler for fcp_pkt recovery
1703  * @fsp: The FCP pkt that needs to be aborted
1704  */
1705 static void fc_fcp_recovery(struct fc_fcp_pkt *fsp, u8 code)
1706 {
1707         FC_FCP_DBG(fsp, "start recovery code %x\n", code);
1708         fsp->status_code = code;
1709         fsp->cdb_status = 0;
1710         fsp->io_status = 0;
1711         /*
1712          * if this fails then we let the scsi command timer fire and
1713          * scsi-ml escalate.
1714          */
1715         fc_fcp_send_abort(fsp);
1716 }
1717
1718 /**
1719  * fc_fcp_srr() - Send a SRR request (Sequence Retransmission Request)
1720  * @fsp:   The FCP packet the SRR is to be sent on
1721  * @r_ctl: The R_CTL field for the SRR request
1722  * This is called after receiving status but insufficient data, or
1723  * when expecting status but the request has timed out.
1724  */
1725 static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
1726 {
1727         struct fc_lport *lport = fsp->lp;
1728         struct fc_rport *rport;
1729         struct fc_rport_libfc_priv *rpriv;
1730         struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
1731         struct fc_seq *seq;
1732         struct fcp_srr *srr;
1733         struct fc_frame *fp;
1734
1735         rport = fsp->rport;
1736         rpriv = rport->dd_data;
1737
1738         if (!(rpriv->flags & FC_RP_FLAGS_RETRY) ||
1739             rpriv->rp_state != RPORT_ST_READY)
1740                 goto retry;                     /* shouldn't happen */
1741         fp = fc_fcp_frame_alloc(lport, sizeof(*srr));
1742         if (!fp)
1743                 goto retry;
1744
1745         srr = fc_frame_payload_get(fp, sizeof(*srr));
1746         memset(srr, 0, sizeof(*srr));
1747         srr->srr_op = ELS_SRR;
1748         srr->srr_ox_id = htons(ep->oxid);
1749         srr->srr_rx_id = htons(ep->rxid);
1750         srr->srr_r_ctl = r_ctl;
1751         srr->srr_rel_off = htonl(offset);
1752
1753         fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
1754                        rpriv->local_port->port_id, FC_TYPE_FCP,
1755                        FC_FCTL_REQ, 0);
1756
1757         seq = fc_exch_seq_send(lport, fp, fc_fcp_srr_resp,
1758                                fc_fcp_pkt_destroy,
1759                                fsp, get_fsp_rec_tov(fsp));
1760         if (!seq)
1761                 goto retry;
1762
1763         fsp->recov_seq = seq;
1764         fsp->xfer_len = offset;
1765         fsp->xfer_contig_end = offset;
1766         fsp->state &= ~FC_SRB_RCV_STATUS;
1767         fc_fcp_pkt_hold(fsp);           /* hold for outstanding SRR */
1768         return;
1769 retry:
1770         fc_fcp_retry_cmd(fsp, FC_TRANS_RESET);
1771 }
1772
1773 /**
1774  * fc_fcp_srr_resp() - Handler for SRR response
1775  * @seq: The sequence the SRR is on
1776  * @fp:  The SRR frame
1777  * @arg: The FCP packet the SRR is on
1778  */
1779 static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
1780 {
1781         struct fc_fcp_pkt *fsp = arg;
1782         struct fc_frame_header *fh;
1783
1784         if (IS_ERR(fp)) {
1785                 fc_fcp_srr_error(fsp, fp);
1786                 return;
1787         }
1788
1789         if (fc_fcp_lock_pkt(fsp))
1790                 goto out;
1791
1792         fh = fc_frame_header_get(fp);
1793         /*
1794          * BUG? fc_fcp_srr_error calls fc_exch_done which would release
1795          * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
1796          * then fc_exch_timeout would be sending an abort. The fc_exch_done
1797          * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
1798          * an abort response though.
1799          */
1800         if (fh->fh_type == FC_TYPE_BLS) {
1801                 fc_fcp_unlock_pkt(fsp);
1802                 return;
1803         }
1804
1805         switch (fc_frame_payload_op(fp)) {
1806         case ELS_LS_ACC:
1807                 fsp->recov_retry = 0;
1808                 fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
1809                 break;
1810         case ELS_LS_RJT:
1811         default:
1812                 fc_fcp_recovery(fsp, FC_ERROR);
1813                 break;
1814         }
1815         fc_fcp_unlock_pkt(fsp);
1816 out:
1817         fc_exch_done(seq);
1818         fc_frame_free(fp);
1819 }
1820
1821 /**
1822  * fc_fcp_srr_error() - Handler for SRR errors
1823  * @fsp: The FCP packet that the SRR error is on
1824  * @fp:  The SRR frame
1825  */
1826 static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
1827 {
1828         if (fc_fcp_lock_pkt(fsp))
1829                 goto out;
1830         switch (PTR_ERR(fp)) {
1831         case -FC_EX_TIMEOUT:
1832                 FC_FCP_DBG(fsp, "SRR timeout, retries %d\n", fsp->recov_retry);
1833                 if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
1834                         fc_fcp_rec(fsp);
1835                 else
1836                         fc_fcp_recovery(fsp, FC_TIMED_OUT);
1837                 break;
1838         case -FC_EX_CLOSED:                     /* e.g., link failure */
1839                 FC_FCP_DBG(fsp, "SRR error, exchange closed\n");
1840                 /* fall through */
1841         default:
1842                 fc_fcp_retry_cmd(fsp, FC_ERROR);
1843                 break;
1844         }
1845         fc_fcp_unlock_pkt(fsp);
1846 out:
1847         fc_exch_done(fsp->recov_seq);
1848 }
1849
1850 /**
1851  * fc_fcp_lport_queue_ready() - Determine if the lport and it's queue is ready
1852  * @lport: The local port to be checked
1853  */
1854 static inline int fc_fcp_lport_queue_ready(struct fc_lport *lport)
1855 {
1856         /* lock ? */
1857         return (lport->state == LPORT_ST_READY) &&
1858                 lport->link_up && !lport->qfull;
1859 }
1860
1861 /**
1862  * fc_queuecommand() - The queuecommand function of the SCSI template
1863  * @shost: The Scsi_Host that the command was issued to
1864  * @cmd:   The scsi_cmnd to be executed
1865  *
1866  * This is the i/o strategy routine, called by the SCSI layer.
1867  */
1868 int fc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *sc_cmd)
1869 {
1870         struct fc_lport *lport = shost_priv(shost);
1871         struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
1872         struct fc_fcp_pkt *fsp;
1873         struct fc_rport_libfc_priv *rpriv;
1874         int rval;
1875         int rc = 0;
1876         struct fc_stats *stats;
1877
1878         rval = fc_remote_port_chkready(rport);
1879         if (rval) {
1880                 sc_cmd->result = rval;
1881                 sc_cmd->scsi_done(sc_cmd);
1882                 return 0;
1883         }
1884
1885         if (!*(struct fc_remote_port **)rport->dd_data) {
1886                 /*
1887                  * rport is transitioning from blocked/deleted to
1888                  * online
1889                  */
1890                 sc_cmd->result = DID_IMM_RETRY << 16;
1891                 sc_cmd->scsi_done(sc_cmd);
1892                 goto out;
1893         }
1894
1895         rpriv = rport->dd_data;
1896
1897         if (!fc_fcp_lport_queue_ready(lport)) {
1898                 if (lport->qfull) {
1899                         fc_fcp_can_queue_ramp_down(lport);
1900                         shost_printk(KERN_ERR, lport->host,
1901                                      "libfc: queue full, "
1902                                      "reducing can_queue to %d.\n",
1903                                      lport->host->can_queue);
1904                 }
1905                 rc = SCSI_MLQUEUE_HOST_BUSY;
1906                 goto out;
1907         }
1908
1909         fsp = fc_fcp_pkt_alloc(lport, GFP_ATOMIC);
1910         if (fsp == NULL) {
1911                 rc = SCSI_MLQUEUE_HOST_BUSY;
1912                 goto out;
1913         }
1914
1915         /*
1916          * build the libfc request pkt
1917          */
1918         fsp->cmd = sc_cmd;      /* save the cmd */
1919         fsp->rport = rport;     /* set the remote port ptr */
1920
1921         /*
1922          * set up the transfer length
1923          */
1924         fsp->data_len = scsi_bufflen(sc_cmd);
1925         fsp->xfer_len = 0;
1926
1927         /*
1928          * setup the data direction
1929          */
1930         stats = per_cpu_ptr(lport->stats, get_cpu());
1931         if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
1932                 fsp->req_flags = FC_SRB_READ;
1933                 stats->InputRequests++;
1934                 stats->InputBytes += fsp->data_len;
1935         } else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
1936                 fsp->req_flags = FC_SRB_WRITE;
1937                 stats->OutputRequests++;
1938                 stats->OutputBytes += fsp->data_len;
1939         } else {
1940                 fsp->req_flags = 0;
1941                 stats->ControlRequests++;
1942         }
1943         put_cpu();
1944
1945         /*
1946          * send it to the lower layer
1947          * if we get -1 return then put the request in the pending
1948          * queue.
1949          */
1950         rval = fc_fcp_pkt_send(lport, fsp);
1951         if (rval != 0) {
1952                 fsp->state = FC_SRB_FREE;
1953                 fc_fcp_pkt_release(fsp);
1954                 rc = SCSI_MLQUEUE_HOST_BUSY;
1955         }
1956 out:
1957         return rc;
1958 }
1959 EXPORT_SYMBOL(fc_queuecommand);
1960
1961 /**
1962  * fc_io_compl() - Handle responses for completed commands
1963  * @fsp: The FCP packet that is complete
1964  *
1965  * Translates fcp_pkt errors to a Linux SCSI errors.
1966  * The fcp packet lock must be held when calling.
1967  */
1968 static void fc_io_compl(struct fc_fcp_pkt *fsp)
1969 {
1970         struct fc_fcp_internal *si;
1971         struct scsi_cmnd *sc_cmd;
1972         struct fc_lport *lport;
1973         unsigned long flags;
1974
1975         /* release outstanding ddp context */
1976         fc_fcp_ddp_done(fsp);
1977
1978         fsp->state |= FC_SRB_COMPL;
1979         if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
1980                 spin_unlock_bh(&fsp->scsi_pkt_lock);
1981                 del_timer_sync(&fsp->timer);
1982                 spin_lock_bh(&fsp->scsi_pkt_lock);
1983         }
1984
1985         lport = fsp->lp;
1986         si = fc_get_scsi_internal(lport);
1987
1988         /*
1989          * if can_queue ramp down is done then try can_queue ramp up
1990          * since commands are completing now.
1991          */
1992         if (si->last_can_queue_ramp_down_time)
1993                 fc_fcp_can_queue_ramp_up(lport);
1994
1995         sc_cmd = fsp->cmd;
1996         CMD_SCSI_STATUS(sc_cmd) = fsp->cdb_status;
1997         switch (fsp->status_code) {
1998         case FC_COMPLETE:
1999                 if (fsp->cdb_status == 0) {
2000                         /*
2001                          * good I/O status
2002                          */
2003                         sc_cmd->result = DID_OK << 16;
2004                         if (fsp->scsi_resid)
2005                                 CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
2006                 } else {
2007                         /*
2008                          * transport level I/O was ok but scsi
2009                          * has non zero status
2010                          */
2011                         sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
2012                 }
2013                 break;
2014         case FC_ERROR:
2015                 FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2016                            "due to FC_ERROR\n");
2017                 sc_cmd->result = DID_ERROR << 16;
2018                 break;
2019         case FC_DATA_UNDRUN:
2020                 if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) {
2021                         /*
2022                          * scsi status is good but transport level
2023                          * underrun.
2024                          */
2025                         if (fsp->state & FC_SRB_RCV_STATUS) {
2026                                 sc_cmd->result = DID_OK << 16;
2027                         } else {
2028                                 FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml"
2029                                            " due to FC_DATA_UNDRUN (trans)\n");
2030                                 sc_cmd->result = DID_ERROR << 16;
2031                         }
2032                 } else {
2033                         /*
2034                          * scsi got underrun, this is an error
2035                          */
2036                         FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2037                                    "due to FC_DATA_UNDRUN (scsi)\n");
2038                         CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
2039                         sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
2040                 }
2041                 break;
2042         case FC_DATA_OVRRUN:
2043                 /*
2044                  * overrun is an error
2045                  */
2046                 FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2047                            "due to FC_DATA_OVRRUN\n");
2048                 sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
2049                 break;
2050         case FC_CMD_ABORTED:
2051                 if (host_byte(sc_cmd->result) == DID_TIME_OUT)
2052                         FC_FCP_DBG(fsp, "Returning DID_TIME_OUT to scsi-ml "
2053                                    "due to FC_CMD_ABORTED\n");
2054                 else {
2055                         FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2056                                    "due to FC_CMD_ABORTED\n");
2057                         set_host_byte(sc_cmd, DID_ERROR);
2058                 }
2059                 sc_cmd->result |= fsp->io_status;
2060                 break;
2061         case FC_CMD_RESET:
2062                 FC_FCP_DBG(fsp, "Returning DID_RESET to scsi-ml "
2063                            "due to FC_CMD_RESET\n");
2064                 sc_cmd->result = (DID_RESET << 16);
2065                 break;
2066         case FC_TRANS_RESET:
2067                 FC_FCP_DBG(fsp, "Returning DID_SOFT_ERROR to scsi-ml "
2068                            "due to FC_TRANS_RESET\n");
2069                 sc_cmd->result = (DID_SOFT_ERROR << 16);
2070                 break;
2071         case FC_HRD_ERROR:
2072                 FC_FCP_DBG(fsp, "Returning DID_NO_CONNECT to scsi-ml "
2073                            "due to FC_HRD_ERROR\n");
2074                 sc_cmd->result = (DID_NO_CONNECT << 16);
2075                 break;
2076         case FC_CRC_ERROR:
2077                 FC_FCP_DBG(fsp, "Returning DID_PARITY to scsi-ml "
2078                            "due to FC_CRC_ERROR\n");
2079                 sc_cmd->result = (DID_PARITY << 16);
2080                 break;
2081         case FC_TIMED_OUT:
2082                 FC_FCP_DBG(fsp, "Returning DID_BUS_BUSY to scsi-ml "
2083                            "due to FC_TIMED_OUT\n");
2084                 sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
2085                 break;
2086         default:
2087                 FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
2088                            "due to unknown error\n");
2089                 sc_cmd->result = (DID_ERROR << 16);
2090                 break;
2091         }
2092
2093         if (lport->state != LPORT_ST_READY && fsp->status_code != FC_COMPLETE)
2094                 sc_cmd->result = (DID_TRANSPORT_DISRUPTED << 16);
2095
2096         spin_lock_irqsave(&si->scsi_queue_lock, flags);
2097         list_del(&fsp->list);
2098         sc_cmd->SCp.ptr = NULL;
2099         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2100         sc_cmd->scsi_done(sc_cmd);
2101
2102         /* release ref from initial allocation in queue command */
2103         fc_fcp_pkt_release(fsp);
2104 }
2105
2106 /**
2107  * fc_eh_abort() - Abort a command
2108  * @sc_cmd: The SCSI command to abort
2109  *
2110  * From SCSI host template.
2111  * Send an ABTS to the target device and wait for the response.
2112  */
2113 int fc_eh_abort(struct scsi_cmnd *sc_cmd)
2114 {
2115         struct fc_fcp_pkt *fsp;
2116         struct fc_lport *lport;
2117         struct fc_fcp_internal *si;
2118         int rc = FAILED;
2119         unsigned long flags;
2120         int rval;
2121
2122         rval = fc_block_scsi_eh(sc_cmd);
2123         if (rval)
2124                 return rval;
2125
2126         lport = shost_priv(sc_cmd->device->host);
2127         if (lport->state != LPORT_ST_READY)
2128                 return rc;
2129         else if (!lport->link_up)
2130                 return rc;
2131
2132         si = fc_get_scsi_internal(lport);
2133         spin_lock_irqsave(&si->scsi_queue_lock, flags);
2134         fsp = CMD_SP(sc_cmd);
2135         if (!fsp) {
2136                 /* command completed while scsi eh was setting up */
2137                 spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2138                 return SUCCESS;
2139         }
2140         /* grab a ref so the fsp and sc_cmd cannot be released from under us */
2141         fc_fcp_pkt_hold(fsp);
2142         spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
2143
2144         if (fc_fcp_lock_pkt(fsp)) {
2145                 /* completed while we were waiting for timer to be deleted */
2146                 rc = SUCCESS;
2147                 goto release_pkt;
2148         }
2149
2150         rc = fc_fcp_pkt_abort(fsp);
2151         fc_fcp_unlock_pkt(fsp);
2152
2153 release_pkt:
2154         fc_fcp_pkt_release(fsp);
2155         return rc;
2156 }
2157 EXPORT_SYMBOL(fc_eh_abort);
2158
2159 /**
2160  * fc_eh_device_reset() - Reset a single LUN
2161  * @sc_cmd: The SCSI command which identifies the device whose
2162  *          LUN is to be reset
2163  *
2164  * Set from SCSI host template.
2165  */
2166 int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
2167 {
2168         struct fc_lport *lport;
2169         struct fc_fcp_pkt *fsp;
2170         struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
2171         int rc = FAILED;
2172         int rval;
2173
2174         rval = fc_block_scsi_eh(sc_cmd);
2175         if (rval)
2176                 return rval;
2177
2178         lport = shost_priv(sc_cmd->device->host);
2179
2180         if (lport->state != LPORT_ST_READY)
2181                 return rc;
2182
2183         FC_SCSI_DBG(lport, "Resetting rport (%6.6x)\n", rport->port_id);
2184
2185         fsp = fc_fcp_pkt_alloc(lport, GFP_NOIO);
2186         if (fsp == NULL) {
2187                 printk(KERN_WARNING "libfc: could not allocate scsi_pkt\n");
2188                 goto out;
2189         }
2190
2191         /*
2192          * Build the libfc request pkt. Do not set the scsi cmnd, because
2193          * the sc passed in is not setup for execution like when sent
2194          * through the queuecommand callout.
2195          */
2196         fsp->rport = rport;     /* set the remote port ptr */
2197
2198         /*
2199          * flush outstanding commands
2200          */
2201         rc = fc_lun_reset(lport, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
2202         fsp->state = FC_SRB_FREE;
2203         fc_fcp_pkt_release(fsp);
2204
2205 out:
2206         return rc;
2207 }
2208 EXPORT_SYMBOL(fc_eh_device_reset);
2209
2210 /**
2211  * fc_eh_host_reset() - Reset a Scsi_Host.
2212  * @sc_cmd: The SCSI command that identifies the SCSI host to be reset
2213  */
2214 int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
2215 {
2216         struct Scsi_Host *shost = sc_cmd->device->host;
2217         struct fc_lport *lport = shost_priv(shost);
2218         unsigned long wait_tmo;
2219
2220         FC_SCSI_DBG(lport, "Resetting host\n");
2221
2222         fc_block_scsi_eh(sc_cmd);
2223
2224         fc_lport_reset(lport);
2225         wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
2226         while (!fc_fcp_lport_queue_ready(lport) && time_before(jiffies,
2227                                                                wait_tmo))
2228                 msleep(1000);
2229
2230         if (fc_fcp_lport_queue_ready(lport)) {
2231                 shost_printk(KERN_INFO, shost, "libfc: Host reset succeeded "
2232                              "on port (%6.6x)\n", lport->port_id);
2233                 return SUCCESS;
2234         } else {
2235                 shost_printk(KERN_INFO, shost, "libfc: Host reset failed, "
2236                              "port (%6.6x) is not ready.\n",
2237                              lport->port_id);
2238                 return FAILED;
2239         }
2240 }
2241 EXPORT_SYMBOL(fc_eh_host_reset);
2242
2243 /**
2244  * fc_slave_alloc() - Configure the queue depth of a Scsi_Host
2245  * @sdev: The SCSI device that identifies the SCSI host
2246  *
2247  * Configures queue depth based on host's cmd_per_len. If not set
2248  * then we use the libfc default.
2249  */
2250 int fc_slave_alloc(struct scsi_device *sdev)
2251 {
2252         struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
2253
2254         if (!rport || fc_remote_port_chkready(rport))
2255                 return -ENXIO;
2256
2257         scsi_change_queue_depth(sdev, FC_FCP_DFLT_QUEUE_DEPTH);
2258         return 0;
2259 }
2260 EXPORT_SYMBOL(fc_slave_alloc);
2261
2262 /**
2263  * fc_fcp_destory() - Tear down the FCP layer for a given local port
2264  * @lport: The local port that no longer needs the FCP layer
2265  */
2266 void fc_fcp_destroy(struct fc_lport *lport)
2267 {
2268         struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
2269
2270         if (!list_empty(&si->scsi_pkt_queue))
2271                 printk(KERN_ERR "libfc: Leaked SCSI packets when destroying "
2272                        "port (%6.6x)\n", lport->port_id);
2273
2274         mempool_destroy(si->scsi_pkt_pool);
2275         kfree(si);
2276         lport->scsi_priv = NULL;
2277 }
2278 EXPORT_SYMBOL(fc_fcp_destroy);
2279
2280 int fc_setup_fcp(void)
2281 {
2282         int rc = 0;
2283
2284         scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
2285                                             sizeof(struct fc_fcp_pkt),
2286                                             0, SLAB_HWCACHE_ALIGN, NULL);
2287         if (!scsi_pkt_cachep) {
2288                 printk(KERN_ERR "libfc: Unable to allocate SRB cache, "
2289                        "module load failed!");
2290                 rc = -ENOMEM;
2291         }
2292
2293         return rc;
2294 }
2295
2296 void fc_destroy_fcp(void)
2297 {
2298         if (scsi_pkt_cachep)
2299                 kmem_cache_destroy(scsi_pkt_cachep);
2300 }
2301
2302 /**
2303  * fc_fcp_init() - Initialize the FCP layer for a local port
2304  * @lport: The local port to initialize the exchange layer for
2305  */
2306 int fc_fcp_init(struct fc_lport *lport)
2307 {
2308         int rc;
2309         struct fc_fcp_internal *si;
2310
2311         if (!lport->tt.fcp_cmd_send)
2312                 lport->tt.fcp_cmd_send = fc_fcp_cmd_send;
2313
2314         if (!lport->tt.fcp_cleanup)
2315                 lport->tt.fcp_cleanup = fc_fcp_cleanup;
2316
2317         if (!lport->tt.fcp_abort_io)
2318                 lport->tt.fcp_abort_io = fc_fcp_abort_io;
2319
2320         si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
2321         if (!si)
2322                 return -ENOMEM;
2323         lport->scsi_priv = si;
2324         si->max_can_queue = lport->host->can_queue;
2325         INIT_LIST_HEAD(&si->scsi_pkt_queue);
2326         spin_lock_init(&si->scsi_queue_lock);
2327
2328         si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
2329         if (!si->scsi_pkt_pool) {
2330                 rc = -ENOMEM;
2331                 goto free_internal;
2332         }
2333         return 0;
2334
2335 free_internal:
2336         kfree(si);
2337         return rc;
2338 }
2339 EXPORT_SYMBOL(fc_fcp_init);