forked from microsoft/WSL2-Linux-Kernel
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathfc_fcp.c
2285 lines (2035 loc) · 59 KB
/
fc_fcp.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* Copyright(c) 2007 Intel Corporation. All rights reserved.
* Copyright(c) 2008 Red Hat, Inc. All rights reserved.
* Copyright(c) 2008 Mike Christie
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*
* Maintained at www.Open-FCoE.org
*/
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/scatterlist.h>
#include <linux/err.h>
#include <linux/crc32.h>
#include <linux/slab.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/fc/fc_fc2.h>
#include <scsi/libfc.h>
#include <scsi/fc_encode.h>
#include "fc_libfc.h"
static struct kmem_cache *scsi_pkt_cachep;
/* SRB state definitions */
#define FC_SRB_FREE 0 /* cmd is free */
#define FC_SRB_CMD_SENT (1 << 0) /* cmd has been sent */
#define FC_SRB_RCV_STATUS (1 << 1) /* response has arrived */
#define FC_SRB_ABORT_PENDING (1 << 2) /* cmd abort sent to device */
#define FC_SRB_ABORTED (1 << 3) /* abort acknowledged */
#define FC_SRB_DISCONTIG (1 << 4) /* non-sequential data recvd */
#define FC_SRB_COMPL (1 << 5) /* fc_io_compl has been run */
#define FC_SRB_FCP_PROCESSING_TMO (1 << 6) /* timer function processing */
#define FC_SRB_READ (1 << 1)
#define FC_SRB_WRITE (1 << 0)
/*
* The SCp.ptr should be tested and set under the scsi_pkt_queue lock
*/
#define CMD_SP(Cmnd) ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)
#define CMD_ENTRY_STATUS(Cmnd) ((Cmnd)->SCp.have_data_in)
#define CMD_COMPL_STATUS(Cmnd) ((Cmnd)->SCp.this_residual)
#define CMD_SCSI_STATUS(Cmnd) ((Cmnd)->SCp.Status)
#define CMD_RESID_LEN(Cmnd) ((Cmnd)->SCp.buffers_residual)
/**
* struct fc_fcp_internal - FCP layer internal data
* @scsi_pkt_pool: Memory pool to draw FCP packets from
* @scsi_queue_lock: Protects the scsi_pkt_queue
* @scsi_pkt_queue: Current FCP packets
* @last_can_queue_ramp_down_time: ramp down time
* @last_can_queue_ramp_up_time: ramp up time
* @max_can_queue: max can_queue size
*/
struct fc_fcp_internal {
mempool_t *scsi_pkt_pool;
spinlock_t scsi_queue_lock;
struct list_head scsi_pkt_queue;
unsigned long last_can_queue_ramp_down_time;
unsigned long last_can_queue_ramp_up_time;
int max_can_queue;
};
#define fc_get_scsi_internal(x) ((struct fc_fcp_internal *)(x)->scsi_priv)
/*
* function prototypes
* FC scsi I/O related functions
*/
static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
static void fc_fcp_error(struct fc_fcp_pkt *, struct fc_frame *);
static void fc_fcp_recovery(struct fc_fcp_pkt *, u8 code);
static void fc_fcp_timeout(unsigned long);
static void fc_fcp_rec(struct fc_fcp_pkt *);
static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
static void fc_io_compl(struct fc_fcp_pkt *);
static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
/*
* command status codes
*/
#define FC_COMPLETE 0
#define FC_CMD_ABORTED 1
#define FC_CMD_RESET 2
#define FC_CMD_PLOGO 3
#define FC_SNS_RCV 4
#define FC_TRANS_ERR 5
#define FC_DATA_OVRRUN 6
#define FC_DATA_UNDRUN 7
#define FC_ERROR 8
#define FC_HRD_ERROR 9
#define FC_CRC_ERROR 10
#define FC_TIMED_OUT 11
/*
* Error recovery timeout values.
*/
#define FC_SCSI_TM_TOV (10 * HZ)
#define FC_HOST_RESET_TIMEOUT (30 * HZ)
#define FC_CAN_QUEUE_PERIOD (60 * HZ)
#define FC_MAX_ERROR_CNT 5
#define FC_MAX_RECOV_RETRY 3
#define FC_FCP_DFLT_QUEUE_DEPTH 32
/**
* fc_fcp_pkt_alloc() - Allocate a fcp_pkt
* @lport: The local port that the FCP packet is for
* @gfp: GFP flags for allocation
*
* Return value: fcp_pkt structure or null on allocation failure.
* Context: Can be called from process context, no lock is required.
*/
static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lport, gfp_t gfp)
{
struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
struct fc_fcp_pkt *fsp;
fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
if (fsp) {
memset(fsp, 0, sizeof(*fsp));
fsp->lp = lport;
fsp->xfer_ddp = FC_XID_UNKNOWN;
atomic_set(&fsp->ref_cnt, 1);
init_timer(&fsp->timer);
INIT_LIST_HEAD(&fsp->list);
spin_lock_init(&fsp->scsi_pkt_lock);
}
return fsp;
}
/**
* fc_fcp_pkt_release() - Release hold on a fcp_pkt
* @fsp: The FCP packet to be released
*
* Context: Can be called from process or interrupt context,
* no lock is required.
*/
static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
{
if (atomic_dec_and_test(&fsp->ref_cnt)) {
struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
mempool_free(fsp, si->scsi_pkt_pool);
}
}
/**
* fc_fcp_pkt_hold() - Hold a fcp_pkt
* @fsp: The FCP packet to be held
*/
static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
{
atomic_inc(&fsp->ref_cnt);
}
/**
* fc_fcp_pkt_destory() - Release hold on a fcp_pkt
* @seq: The sequence that the FCP packet is on (required by destructor API)
* @fsp: The FCP packet to be released
*
* This routine is called by a destructor callback in the exch_seq_send()
* routine of the libfc Transport Template. The 'struct fc_seq' is a required
* argument even though it is not used by this routine.
*
* Context: No locking required.
*/
static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
{
fc_fcp_pkt_release(fsp);
}
/**
* fc_fcp_lock_pkt() - Lock a fcp_pkt and increase its reference count
* @fsp: The FCP packet to be locked and incremented
*
* We should only return error if we return a command to SCSI-ml before
* getting a response. This can happen in cases where we send a abort, but
* do not wait for the response and the abort and command can be passing
* each other on the wire/network-layer.
*
* Note: this function locks the packet and gets a reference to allow
* callers to call the completion function while the lock is held and
* not have to worry about the packets refcount.
*
* TODO: Maybe we should just have callers grab/release the lock and
* have a function that they call to verify the fsp and grab a ref if
* needed.
*/
static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
{
spin_lock_bh(&fsp->scsi_pkt_lock);
if (fsp->state & FC_SRB_COMPL) {
spin_unlock_bh(&fsp->scsi_pkt_lock);
return -EPERM;
}
fc_fcp_pkt_hold(fsp);
return 0;
}
/**
* fc_fcp_unlock_pkt() - Release a fcp_pkt's lock and decrement its
* reference count
* @fsp: The FCP packet to be unlocked and decremented
*/
static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
{
spin_unlock_bh(&fsp->scsi_pkt_lock);
fc_fcp_pkt_release(fsp);
}
/**
* fc_fcp_timer_set() - Start a timer for a fcp_pkt
* @fsp: The FCP packet to start a timer for
* @delay: The timeout period in jiffies
*/
static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
{
if (!(fsp->state & FC_SRB_COMPL))
mod_timer(&fsp->timer, jiffies + delay);
}
/**
* fc_fcp_send_abort() - Send an abort for exchanges associated with a
* fcp_pkt
* @fsp: The FCP packet to abort exchanges on
*/
static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
{
if (!fsp->seq_ptr)
return -EINVAL;
fsp->state |= FC_SRB_ABORT_PENDING;
return fsp->lp->tt.seq_exch_abort(fsp->seq_ptr, 0);
}
/**
* fc_fcp_retry_cmd() - Retry a fcp_pkt
* @fsp: The FCP packet to be retried
*
* Sets the status code to be FC_ERROR and then calls
* fc_fcp_complete_locked() which in turn calls fc_io_compl().
* fc_io_compl() will notify the SCSI-ml that the I/O is done.
* The SCSI-ml will retry the command.
*/
static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp)
{
if (fsp->seq_ptr) {
fsp->lp->tt.exch_done(fsp->seq_ptr);
fsp->seq_ptr = NULL;
}
fsp->state &= ~FC_SRB_ABORT_PENDING;
fsp->io_status = 0;
fsp->status_code = FC_ERROR;
fc_fcp_complete_locked(fsp);
}
/**
* fc_fcp_ddp_setup() - Calls a LLD's ddp_setup routine to set up DDP context
* @fsp: The FCP packet that will manage the DDP frames
* @xid: The XID that will be used for the DDP exchange
*/
void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
{
struct fc_lport *lport;
lport = fsp->lp;
if ((fsp->req_flags & FC_SRB_READ) &&
(lport->lro_enabled) && (lport->tt.ddp_setup)) {
if (lport->tt.ddp_setup(lport, xid, scsi_sglist(fsp->cmd),
scsi_sg_count(fsp->cmd)))
fsp->xfer_ddp = xid;
}
}
/**
* fc_fcp_ddp_done() - Calls a LLD's ddp_done routine to release any
* DDP related resources for a fcp_pkt
* @fsp: The FCP packet that DDP had been used on
*/
void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
{
struct fc_lport *lport;
if (!fsp)
return;
if (fsp->xfer_ddp == FC_XID_UNKNOWN)
return;
lport = fsp->lp;
if (lport->tt.ddp_done) {
fsp->xfer_len = lport->tt.ddp_done(lport, fsp->xfer_ddp);
fsp->xfer_ddp = FC_XID_UNKNOWN;
}
}
/**
* fc_fcp_can_queue_ramp_up() - increases can_queue
* @lport: lport to ramp up can_queue
*/
static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
{
struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
unsigned long flags;
int can_queue;
spin_lock_irqsave(lport->host->host_lock, flags);
if (si->last_can_queue_ramp_up_time &&
(time_before(jiffies, si->last_can_queue_ramp_up_time +
FC_CAN_QUEUE_PERIOD)))
goto unlock;
if (time_before(jiffies, si->last_can_queue_ramp_down_time +
FC_CAN_QUEUE_PERIOD))
goto unlock;
si->last_can_queue_ramp_up_time = jiffies;
can_queue = lport->host->can_queue << 1;
if (can_queue >= si->max_can_queue) {
can_queue = si->max_can_queue;
si->last_can_queue_ramp_down_time = 0;
}
lport->host->can_queue = can_queue;
shost_printk(KERN_ERR, lport->host, "libfc: increased "
"can_queue to %d.\n", can_queue);
unlock:
spin_unlock_irqrestore(lport->host->host_lock, flags);
}
/**
* fc_fcp_can_queue_ramp_down() - reduces can_queue
* @lport: lport to reduce can_queue
*
* If we are getting memory allocation failures, then we may
* be trying to execute too many commands. We let the running
* commands complete or timeout, then try again with a reduced
* can_queue. Eventually we will hit the point where we run
* on all reserved structs.
*/
static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport)
{
struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
unsigned long flags;
int can_queue;
spin_lock_irqsave(lport->host->host_lock, flags);
if (si->last_can_queue_ramp_down_time &&
(time_before(jiffies, si->last_can_queue_ramp_down_time +
FC_CAN_QUEUE_PERIOD)))
goto unlock;
si->last_can_queue_ramp_down_time = jiffies;
can_queue = lport->host->can_queue;
can_queue >>= 1;
if (!can_queue)
can_queue = 1;
lport->host->can_queue = can_queue;
shost_printk(KERN_ERR, lport->host, "libfc: Could not allocate frame.\n"
"Reducing can_queue to %d.\n", can_queue);
unlock:
spin_unlock_irqrestore(lport->host->host_lock, flags);
}
/*
* fc_fcp_frame_alloc() - Allocates fc_frame structure and buffer.
* @lport: fc lport struct
* @len: payload length
*
* Allocates fc_frame structure and buffer but if fails to allocate
* then reduce can_queue.
*/
static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport,
size_t len)
{
struct fc_frame *fp;
fp = fc_frame_alloc(lport, len);
if (likely(fp))
return fp;
/* error case */
fc_fcp_can_queue_ramp_down(lport);
return NULL;
}
/**
* fc_fcp_recv_data() - Handler for receiving SCSI-FCP data from a target
* @fsp: The FCP packet the data is on
* @fp: The data frame
*/
static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
{
struct scsi_cmnd *sc = fsp->cmd;
struct fc_lport *lport = fsp->lp;
struct fcoe_dev_stats *stats;
struct fc_frame_header *fh;
size_t start_offset;
size_t offset;
u32 crc;
u32 copy_len = 0;
size_t len;
void *buf;
struct scatterlist *sg;
u32 nents;
u8 host_bcode = FC_COMPLETE;
fh = fc_frame_header_get(fp);
offset = ntohl(fh->fh_parm_offset);
start_offset = offset;
len = fr_len(fp) - sizeof(*fh);
buf = fc_frame_payload_get(fp, 0);
/*
* if this I/O is ddped then clear it and initiate recovery since data
* frames are expected to be placed directly in that case.
*
* Indicate error to scsi-ml because something went wrong with the
* ddp handling to get us here.
*/
if (fsp->xfer_ddp != FC_XID_UNKNOWN) {
fc_fcp_ddp_done(fsp);
FC_FCP_DBG(fsp, "DDP I/O in fc_fcp_recv_data set ERROR\n");
host_bcode = FC_ERROR;
goto err;
}
if (offset + len > fsp->data_len) {
/* this should never happen */
if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
fc_frame_crc_check(fp))
goto crc_err;
FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
"data_len %x\n", len, offset, fsp->data_len);
/* Data is corrupted indicate scsi-ml should retry */
host_bcode = FC_DATA_OVRRUN;
goto err;
}
if (offset != fsp->xfer_len)
fsp->state |= FC_SRB_DISCONTIG;
sg = scsi_sglist(sc);
nents = scsi_sg_count(sc);
if (!(fr_flags(fp) & FCPHF_CRC_UNCHECKED)) {
copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
&offset, KM_SOFTIRQ0, NULL);
} else {
crc = crc32(~0, (u8 *) fh, sizeof(*fh));
copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
&offset, KM_SOFTIRQ0, &crc);
buf = fc_frame_payload_get(fp, 0);
if (len % 4)
crc = crc32(crc, buf + len, 4 - (len % 4));
if (~crc != le32_to_cpu(fr_crc(fp))) {
crc_err:
stats = per_cpu_ptr(lport->dev_stats, get_cpu());
stats->ErrorFrames++;
/* per cpu count, not total count, but OK for limit */
if (stats->InvalidCRCCount++ < 5)
printk(KERN_WARNING "libfc: CRC error on data "
"frame for port (%6.6x)\n",
lport->port_id);
put_cpu();
/*
* Assume the frame is total garbage.
* We may have copied it over the good part
* of the buffer.
* If so, we need to retry the entire operation.
* Otherwise, ignore it.
*/
if (fsp->state & FC_SRB_DISCONTIG) {
host_bcode = FC_CRC_ERROR;
goto err;
}
return;
}
}
if (fsp->xfer_contig_end == start_offset)
fsp->xfer_contig_end += copy_len;
fsp->xfer_len += copy_len;
/*
* In the very rare event that this data arrived after the response
* and completes the transfer, call the completion handler.
*/
if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
fsp->xfer_len == fsp->data_len - fsp->scsi_resid)
fc_fcp_complete_locked(fsp);
return;
err:
fc_fcp_recovery(fsp, host_bcode);
}
/**
* fc_fcp_send_data() - Send SCSI data to a target
* @fsp: The FCP packet the data is on
* @sp: The sequence the data is to be sent on
* @offset: The starting offset for this data request
* @seq_blen: The burst length for this data request
*
* Called after receiving a Transfer Ready data descriptor.
* If the LLD is capable of sequence offload then send down the
* seq_blen amount of data in single frame, otherwise send
* multiple frames of the maximum frame payload supported by
* the target port.
*/
static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
size_t offset, size_t seq_blen)
{
struct fc_exch *ep;
struct scsi_cmnd *sc;
struct scatterlist *sg;
struct fc_frame *fp = NULL;
struct fc_lport *lport = fsp->lp;
struct page *page;
size_t remaining;
size_t t_blen;
size_t tlen;
size_t sg_bytes;
size_t frame_offset, fh_parm_offset;
size_t off;
int error;
void *data = NULL;
void *page_addr;
int using_sg = lport->sg_supp;
u32 f_ctl;
WARN_ON(seq_blen <= 0);
if (unlikely(offset + seq_blen > fsp->data_len)) {
/* this should never happen */
FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
"offset %zx\n", seq_blen, offset);
fc_fcp_send_abort(fsp);
return 0;
} else if (offset != fsp->xfer_len) {
/* Out of Order Data Request - no problem, but unexpected. */
FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
"seq_blen %zx offset %zx\n", seq_blen, offset);
}
/*
* if LLD is capable of seq_offload then set transport
* burst length (t_blen) to seq_blen, otherwise set t_blen
* to max FC frame payload previously set in fsp->max_payload.
*/
t_blen = fsp->max_payload;
if (lport->seq_offload) {
t_blen = min(seq_blen, (size_t)lport->lso_max);
FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
fsp, seq_blen, lport->lso_max, t_blen);
}
if (t_blen > 512)
t_blen &= ~(512 - 1); /* round down to block size */
sc = fsp->cmd;
remaining = seq_blen;
fh_parm_offset = frame_offset = offset;
tlen = 0;
seq = lport->tt.seq_start_next(seq);
f_ctl = FC_FC_REL_OFF;
WARN_ON(!seq);
sg = scsi_sglist(sc);
while (remaining > 0 && sg) {
if (offset >= sg->length) {
offset -= sg->length;
sg = sg_next(sg);
continue;
}
if (!fp) {
tlen = min(t_blen, remaining);
/*
* TODO. Temporary workaround. fc_seq_send() can't
* handle odd lengths in non-linear skbs.
* This will be the final fragment only.
*/
if (tlen % 4)
using_sg = 0;
fp = fc_frame_alloc(lport, using_sg ? 0 : tlen);
if (!fp)
return -ENOMEM;
data = fc_frame_header_get(fp) + 1;
fh_parm_offset = frame_offset;
fr_max_payload(fp) = fsp->max_payload;
}
off = offset + sg->offset;
sg_bytes = min(tlen, sg->length - offset);
sg_bytes = min(sg_bytes,
(size_t) (PAGE_SIZE - (off & ~PAGE_MASK)));
page = sg_page(sg) + (off >> PAGE_SHIFT);
if (using_sg) {
get_page(page);
skb_fill_page_desc(fp_skb(fp),
skb_shinfo(fp_skb(fp))->nr_frags,
page, off & ~PAGE_MASK, sg_bytes);
fp_skb(fp)->data_len += sg_bytes;
fr_len(fp) += sg_bytes;
fp_skb(fp)->truesize += PAGE_SIZE;
} else {
/*
* The scatterlist item may be bigger than PAGE_SIZE,
* but we must not cross pages inside the kmap.
*/
page_addr = kmap_atomic(page, KM_SOFTIRQ0);
memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
sg_bytes);
kunmap_atomic(page_addr, KM_SOFTIRQ0);
data += sg_bytes;
}
offset += sg_bytes;
frame_offset += sg_bytes;
tlen -= sg_bytes;
remaining -= sg_bytes;
if ((skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN) &&
(tlen))
continue;
/*
* Send sequence with transfer sequence initiative in case
* this is last FCP frame of the sequence.
*/
if (remaining == 0)
f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
ep = fc_seq_exch(seq);
fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
FC_TYPE_FCP, f_ctl, fh_parm_offset);
/*
* send fragment using for a sequence.
*/
error = lport->tt.seq_send(lport, seq, fp);
if (error) {
WARN_ON(1); /* send error should be rare */
return error;
}
fp = NULL;
}
fsp->xfer_len += seq_blen; /* premature count? */
return 0;
}
/**
* fc_fcp_abts_resp() - Send an ABTS response
* @fsp: The FCP packet that is being aborted
* @fp: The response frame
*/
static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
{
int ba_done = 1;
struct fc_ba_rjt *brp;
struct fc_frame_header *fh;
fh = fc_frame_header_get(fp);
switch (fh->fh_r_ctl) {
case FC_RCTL_BA_ACC:
break;
case FC_RCTL_BA_RJT:
brp = fc_frame_payload_get(fp, sizeof(*brp));
if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
break;
/* fall thru */
default:
/*
* we will let the command timeout
* and scsi-ml recover in this case,
* therefore cleared the ba_done flag.
*/
ba_done = 0;
}
if (ba_done) {
fsp->state |= FC_SRB_ABORTED;
fsp->state &= ~FC_SRB_ABORT_PENDING;
if (fsp->wait_for_comp)
complete(&fsp->tm_done);
else
fc_fcp_complete_locked(fsp);
}
}
/**
* fc_fcp_recv() - Reveive an FCP frame
* @seq: The sequence the frame is on
* @fp: The received frame
* @arg: The related FCP packet
*
* Context: Called from Soft IRQ context. Can not be called
* holding the FCP packet list lock.
*/
static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
{
struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
struct fc_lport *lport = fsp->lp;
struct fc_frame_header *fh;
struct fcp_txrdy *dd;
u8 r_ctl;
int rc = 0;
if (IS_ERR(fp)) {
fc_fcp_error(fsp, fp);
return;
}
fh = fc_frame_header_get(fp);
r_ctl = fh->fh_r_ctl;
if (lport->state != LPORT_ST_READY)
goto out;
if (fc_fcp_lock_pkt(fsp))
goto out;
fsp->last_pkt_time = jiffies;
if (fh->fh_type == FC_TYPE_BLS) {
fc_fcp_abts_resp(fsp, fp);
goto unlock;
}
if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING))
goto unlock;
if (r_ctl == FC_RCTL_DD_DATA_DESC) {
/*
* received XFER RDY from the target
* need to send data to the target
*/
WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
dd = fc_frame_payload_get(fp, sizeof(*dd));
WARN_ON(!dd);
rc = fc_fcp_send_data(fsp, seq,
(size_t) ntohl(dd->ft_data_ro),
(size_t) ntohl(dd->ft_burst_len));
if (!rc)
seq->rec_data = fsp->xfer_len;
} else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
/*
* received a DATA frame
* next we will copy the data to the system buffer
*/
WARN_ON(fr_len(fp) < sizeof(*fh)); /* len may be 0 */
fc_fcp_recv_data(fsp, fp);
seq->rec_data = fsp->xfer_contig_end;
} else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
fc_fcp_resp(fsp, fp);
} else {
FC_FCP_DBG(fsp, "unexpected frame. r_ctl %x\n", r_ctl);
}
unlock:
fc_fcp_unlock_pkt(fsp);
out:
fc_frame_free(fp);
}
/**
* fc_fcp_resp() - Handler for FCP responses
* @fsp: The FCP packet the response is for
* @fp: The response frame
*/
static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
{
struct fc_frame_header *fh;
struct fcp_resp *fc_rp;
struct fcp_resp_ext *rp_ex;
struct fcp_resp_rsp_info *fc_rp_info;
u32 plen;
u32 expected_len;
u32 respl = 0;
u32 snsl = 0;
u8 flags = 0;
plen = fr_len(fp);
fh = (struct fc_frame_header *)fr_hdr(fp);
if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
goto len_err;
plen -= sizeof(*fh);
fc_rp = (struct fcp_resp *)(fh + 1);
fsp->cdb_status = fc_rp->fr_status;
flags = fc_rp->fr_flags;
fsp->scsi_comp_flags = flags;
expected_len = fsp->data_len;
/* if ddp, update xfer len */
fc_fcp_ddp_done(fsp);
if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
rp_ex = (void *)(fc_rp + 1);
if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
goto len_err;
fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
if (flags & FCP_RSP_LEN_VAL) {
respl = ntohl(rp_ex->fr_rsp_len);
if (respl != sizeof(*fc_rp_info))
goto len_err;
if (fsp->wait_for_comp) {
/* Abuse cdb_status for rsp code */
fsp->cdb_status = fc_rp_info->rsp_code;
complete(&fsp->tm_done);
/*
* tmfs will not have any scsi cmd so
* exit here
*/
return;
}
}
if (flags & FCP_SNS_LEN_VAL) {
snsl = ntohl(rp_ex->fr_sns_len);
if (snsl > SCSI_SENSE_BUFFERSIZE)
snsl = SCSI_SENSE_BUFFERSIZE;
memcpy(fsp->cmd->sense_buffer,
(char *)fc_rp_info + respl, snsl);
}
}
if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
goto len_err;
if (flags & FCP_RESID_UNDER) {
fsp->scsi_resid = ntohl(rp_ex->fr_resid);
/*
* The cmnd->underflow is the minimum number of
* bytes that must be transferred for this
* command. Provided a sense condition is not
* present, make sure the actual amount
* transferred is at least the underflow value
* or fail.
*/
if (!(flags & FCP_SNS_LEN_VAL) &&
(fc_rp->fr_status == 0) &&
(scsi_bufflen(fsp->cmd) -
fsp->scsi_resid) < fsp->cmd->underflow)
goto err;
expected_len -= fsp->scsi_resid;
} else {
fsp->status_code = FC_ERROR;
}
}
}
fsp->state |= FC_SRB_RCV_STATUS;
/*
* Check for missing or extra data frames.
*/
if (unlikely(fsp->xfer_len != expected_len)) {
if (fsp->xfer_len < expected_len) {
/*
* Some data may be queued locally,
* Wait a at least one jiffy to see if it is delivered.
* If this expires without data, we may do SRR.
*/
fc_fcp_timer_set(fsp, 2);
return;
}
fsp->status_code = FC_DATA_OVRRUN;
FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx greater than expected, "
"len %x, data len %x\n",
fsp->rport->port_id,
fsp->xfer_len, expected_len, fsp->data_len);
}
fc_fcp_complete_locked(fsp);
return;
len_err:
FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
"snsl %u\n", flags, fr_len(fp), respl, snsl);
err:
fsp->status_code = FC_ERROR;
fc_fcp_complete_locked(fsp);
}
/**
* fc_fcp_complete_locked() - Complete processing of a fcp_pkt with the
* fcp_pkt lock held
* @fsp: The FCP packet to be completed
*
* This function may sleep if a timer is pending. The packet lock must be
* held, and the host lock must not be held.
*/
static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
{
struct fc_lport *lport = fsp->lp;
struct fc_seq *seq;
struct fc_exch *ep;
u32 f_ctl;
if (fsp->state & FC_SRB_ABORT_PENDING)
return;
if (fsp->state & FC_SRB_ABORTED) {
if (!fsp->status_code)
fsp->status_code = FC_CMD_ABORTED;
} else {
/*
* Test for transport underrun, independent of response
* underrun status.
*/
if (fsp->xfer_len < fsp->data_len && !fsp->io_status &&
(!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
fsp->xfer_len < fsp->data_len - fsp->scsi_resid)) {
fsp->status_code = FC_DATA_UNDRUN;
fsp->io_status = 0;
}
}
seq = fsp->seq_ptr;
if (seq) {
fsp->seq_ptr = NULL;
if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
struct fc_frame *conf_frame;
struct fc_seq *csp;
csp = lport->tt.seq_start_next(seq);
conf_frame = fc_fcp_frame_alloc(fsp->lp, 0);
if (conf_frame) {
f_ctl = FC_FC_SEQ_INIT;
f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
ep = fc_seq_exch(seq);
fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
ep->did, ep->sid,
FC_TYPE_FCP, f_ctl, 0);
lport->tt.seq_send(lport, csp, conf_frame);
}
}
lport->tt.exch_done(seq);
}
/*
* Some resets driven by SCSI are not I/Os and do not have
* SCSI commands associated with the requests. We should not
* call I/O completion if we do not have a SCSI command.
*/
if (fsp->cmd)
fc_io_compl(fsp);
}
/**
* fc_fcp_cleanup_cmd() - Cancel the active exchange on a fcp_pkt
* @fsp: The FCP packet whose exchanges should be canceled
* @error: The reason for the cancellation
*/
static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
{
struct fc_lport *lport = fsp->lp;
if (fsp->seq_ptr) {
lport->tt.exch_done(fsp->seq_ptr);
fsp->seq_ptr = NULL;
}
fsp->status_code = error;