summaryrefslogtreecommitdiff
path: root/include/linux/nvme-fc-driver.h
blob: 2bb349035431d0cebb6466e857525b15f6790fc4 (plain)
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
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2016, Avago Technologies
 */

#ifndef _NVME_FC_DRIVER_H
#define _NVME_FC_DRIVER_H 1


/*
 * **********************  LLDD FC-NVME Host API ********************
 *
 *  For FC LLDD's that are the NVME Host role.
 *
 * ******************************************************************
 */



/* FC Port role bitmask - can merge with FC Port Roles in fc transport */
#define FC_PORT_ROLE_NVME_INITIATOR	0x10
#define FC_PORT_ROLE_NVME_TARGET	0x20
#define FC_PORT_ROLE_NVME_DISCOVERY	0x40


/**
 * struct nvme_fc_port_info - port-specific ids and FC connection-specific
 *                            data element used during NVME Host role
 *                            registrations
 *
 * Static fields describing the port being registered:
 * @node_name: FC WWNN for the port
 * @port_name: FC WWPN for the port
 * @port_role: What NVME roles are supported (see FC_PORT_ROLE_xxx)
 * @dev_loss_tmo: maximum delay for reconnects to an association on
 *             this device. Used only on a remoteport.
 *
 * Initialization values for dynamic port fields:
 * @port_id:      FC N_Port_ID currently assigned the port. Upper 8 bits must
 *                be set to 0.
 */
struct nvme_fc_port_info {
	u64			node_name;
	u64			port_name;
	u32			port_role;
	u32			port_id;
	u32			dev_loss_tmo;
};


/**
 * struct nvmefc_ls_req - Request structure passed from NVME-FC transport
 *                        to LLDD in order to perform a NVME FC-4 LS
 *                        request and obtain a response.
 *
 * Values set by the NVME-FC layer prior to calling the LLDD ls_req
 * entrypoint.
 * @rqstaddr: pointer to request buffer
 * @rqstdma:  PCI DMA address of request buffer
 * @rqstlen:  Length, in bytes, of request buffer
 * @rspaddr:  pointer to response buffer
 * @rspdma:   PCI DMA address of response buffer
 * @rsplen:   Length, in bytes, of response buffer
 * @timeout:  Maximum amount of time, in seconds, to wait for the LS response.
 *            If timeout exceeded, LLDD to abort LS exchange and complete
 *            LS request with error status.
 * @private:  pointer to memory allocated alongside the ls request structure
 *            that is specifically for the LLDD to use while processing the
 *            request. The length of the buffer corresponds to the
 *            lsrqst_priv_sz value specified in the nvme_fc_port_template
 *            supplied by the LLDD.
 * @done:     The callback routine the LLDD is to invoke upon completion of
 *            the LS request. req argument is the pointer to the original LS
 *            request structure. Status argument must be 0 upon success, a
 *            negative errno on failure (example: -ENXIO).
 */
struct nvmefc_ls_req {
	void			*rqstaddr;
	dma_addr_t		rqstdma;
	u32			rqstlen;
	void			*rspaddr;
	dma_addr_t		rspdma;
	u32			rsplen;
	u32			timeout;

	void			*private;

	void (*done)(struct nvmefc_ls_req *req, int status);

} __aligned(sizeof(u64));	/* alignment for other things alloc'd with */


enum nvmefc_fcp_datadir {
	NVMEFC_FCP_NODATA,	/* payload_length and sg_cnt will be zero */
	NVMEFC_FCP_WRITE,
	NVMEFC_FCP_READ,
};


/**
 * struct nvmefc_fcp_req - Request structure passed from NVME-FC transport
 *                         to LLDD in order to perform a NVME FCP IO operation.
 *
 * Values set by the NVME-FC layer prior to calling the LLDD fcp_io
 * entrypoint.
 * @cmdaddr:   pointer to the FCP CMD IU buffer
 * @rspaddr:   pointer to the FCP RSP IU buffer
 * @cmddma:    PCI DMA address of the FCP CMD IU buffer
 * @rspdma:    PCI DMA address of the FCP RSP IU buffer
 * @cmdlen:    Length, in bytes, of the FCP CMD IU buffer
 * @rsplen:    Length, in bytes, of the FCP RSP IU buffer
 * @payload_length: Length of DATA_IN or DATA_OUT payload data to transfer
 * @sg_table:  scatter/gather structure for payload data
 * @first_sgl: memory for 1st scatter/gather list segment for payload data
 * @sg_cnt:    number of elements in the scatter/gather list
 * @io_dir:    direction of the FCP request (see NVMEFC_FCP_xxx)
 * @sqid:      The nvme SQID the command is being issued on
 * @done:      The callback routine the LLDD is to invoke upon completion of
 *             the FCP operation. req argument is the pointer to the original
 *             FCP IO operation.
 * @private:   pointer to memory allocated alongside the FCP operation
 *             request structure that is specifically for the LLDD to use
 *             while processing the operation. The length of the buffer
 *             corresponds to the fcprqst_priv_sz value specified in the
 *             nvme_fc_port_template supplied by the LLDD.
 *
 * Values set by the LLDD indicating completion status of the FCP operation.
 * Must be set prior to calling the done() callback.
 * @transferred_length: amount of payload data, in bytes, that were
 *             transferred. Should equal payload_length on success.
 * @rcv_rsplen: length, in bytes, of the FCP RSP IU received.
 * @status:    Completion status of the FCP operation. must be 0 upon success,
 *             negative errno value upon failure (ex: -EIO). Note: this is
 *             NOT a reflection of the NVME CQE completion status. Only the
 *             status of the FCP operation at the NVME-FC level.
 */
struct nvmefc_fcp_req {
	void			*cmdaddr;
	void			*rspaddr;
	dma_addr_t		cmddma;
	dma_addr_t		rspdma;
	u16			cmdlen;
	u16			rsplen;

	u32			payload_length;
	struct sg_table		sg_table;
	struct scatterlist	*first_sgl;
	int			sg_cnt;
	enum nvmefc_fcp_datadir	io_dir;

	__le16			sqid;

	void (*done)(struct nvmefc_fcp_req *req);

	void			*private;

	u32			transferred_length;
	u16			rcv_rsplen;
	u32			status;
} __aligned(sizeof(u64));	/* alignment for other things alloc'd with */


/*
 * Direct copy of fc_port_state enum. For later merging
 */
enum nvme_fc_obj_state {
	FC_OBJSTATE_UNKNOWN,
	FC_OBJSTATE_NOTPRESENT,
	FC_OBJSTATE_ONLINE,
	FC_OBJSTATE_OFFLINE,		/* User has taken Port Offline */
	FC_OBJSTATE_BLOCKED,
	FC_OBJSTATE_BYPASSED,
	FC_OBJSTATE_DIAGNOSTICS,
	FC_OBJSTATE_LINKDOWN,
	FC_OBJSTATE_ERROR,
	FC_OBJSTATE_LOOPBACK,
	FC_OBJSTATE_DELETED,
};


/**
 * struct nvme_fc_local_port - structure used between NVME-FC transport and
 *                 a LLDD to reference a local NVME host port.
 *                 Allocated/created by the nvme_fc_register_localport()
 *                 transport interface.
 *
 * Fields with static values for the port. Initialized by the
 * port_info struct supplied to the registration call.
 * @port_num:  NVME-FC transport host port number
 * @port_role: NVME roles are supported on the port (see FC_PORT_ROLE_xxx)
 * @node_name: FC WWNN for the port
 * @port_name: FC WWPN for the port
 * @private:   pointer to memory allocated alongside the local port
 *             structure that is specifically for the LLDD to use.
 *             The length of the buffer corresponds to the local_priv_sz
 *             value specified in the nvme_fc_port_template supplied by
 *             the LLDD.
 * @dev_loss_tmo: maximum delay for reconnects to an association on
 *             this device. To modify, lldd must call
 *             nvme_fc_set_remoteport_devloss().
 *
 * Fields with dynamic values. Values may change base on link state. LLDD
 * may reference fields directly to change them. Initialized by the
 * port_info struct supplied to the registration call.
 * @port_id:      FC N_Port_ID currently assigned the port. Upper 8 bits must
 *                be set to 0.
 * @port_state:   Operational state of the port.
 */
struct nvme_fc_local_port {
	/* static/read-only fields */
	u32 port_num;
	u32 port_role;
	u64 node_name;
	u64 port_name;

	void *private;

	/* dynamic fields */
	u32 port_id;
	enum nvme_fc_obj_state port_state;
} __aligned(sizeof(u64));	/* alignment for other things alloc'd with */


/**
 * struct nvme_fc_remote_port - structure used between NVME-FC transport and
 *                 a LLDD to reference a remote NVME subsystem port.
 *                 Allocated/created by the nvme_fc_register_remoteport()
 *                 transport interface.
 *
 * Fields with static values for the port. Initialized by the
 * port_info struct supplied to the registration call.
 * @port_num:  NVME-FC transport remote subsystem port number
 * @port_role: NVME roles are supported on the port (see FC_PORT_ROLE_xxx)
 * @node_name: FC WWNN for the port
 * @port_name: FC WWPN for the port
 * @localport: pointer to the NVME-FC local host port the subsystem is
 *             connected to.
 * @private:   pointer to memory allocated alongside the remote port
 *             structure that is specifically for the LLDD to use.
 *             The length of the buffer corresponds to the remote_priv_sz
 *             value specified in the nvme_fc_port_template supplied by
 *             the LLDD.
 *
 * Fields with dynamic values. Values may change base on link or login
 * state. LLDD may reference fields directly to change them. Initialized by
 * the port_info struct supplied to the registration call.
 * @port_id:      FC N_Port_ID currently assigned the port. Upper 8 bits must
 *                be set to 0.
 * @port_state:   Operational state of the remote port. Valid values are
 *                ONLINE or UNKNOWN.
 */
struct nvme_fc_remote_port {
	/* static fields */
	u32 port_num;
	u32 port_role;
	u64 node_name;
	u64 port_name;
	struct nvme_fc_local_port *localport;
	void *private;
	u32 dev_loss_tmo;

	/* dynamic fields */
	u32 port_id;
	enum nvme_fc_obj_state port_state;
} __aligned(sizeof(u64));	/* alignment for other things alloc'd with */


/**
 * struct nvme_fc_port_template - structure containing static entrypoints and
 *                 operational parameters for an LLDD that supports NVME host
 *                 behavior. Passed by reference in port registrations.
 *                 NVME-FC transport remembers template reference and may
 *                 access it during runtime operation.
 *
 * Host/Initiator Transport Entrypoints/Parameters:
 *
 * @localport_delete:  The LLDD initiates deletion of a localport via
 *       nvme_fc_deregister_localport(). However, the teardown is
 *       asynchronous. This routine is called upon the completion of the
 *       teardown to inform the LLDD that the localport has been deleted.
 *       Entrypoint is Mandatory.
 *
 * @remoteport_delete:  The LLDD initiates deletion of a remoteport via
 *       nvme_fc_deregister_remoteport(). However, the teardown is
 *       asynchronous. This routine is called upon the completion of the
 *       teardown to inform the LLDD that the remoteport has been deleted.
 *       Entrypoint is Mandatory.
 *
 * @create_queue:  Upon creating a host<->controller association, queues are
 *       created such that they can be affinitized to cpus/cores. This
 *       callback into the LLDD to notify that a controller queue is being
 *       created.  The LLDD may choose to allocate an associated hw queue
 *       or map it onto a shared hw queue. Upon return from the call, the
 *       LLDD specifies a handle that will be given back to it for any
 *       command that is posted to the controller queue.  The handle can
 *       be used by the LLDD to map quickly to the proper hw queue for
 *       command execution.  The mask of cpu's that will map to this queue
 *       at the block-level is also passed in. The LLDD should use the
 *       queue id and/or cpu masks to ensure proper affinitization of the
 *       controller queue to the hw queue.
 *       Entrypoint is Optional.
 *
 * @delete_queue:  This is the inverse of the crete_queue. During
 *       host<->controller association teardown, this routine is called
 *       when a controller queue is being terminated. Any association with
 *       a hw queue should be termined. If there is a unique hw queue, the
 *       hw queue should be torn down.
 *       Entrypoint is Optional.
 *
 * @poll_queue:  Called to poll for the completion of an io on a blk queue.
 *       Entrypoint is Optional.
 *
 * @ls_req:  Called to issue a FC-NVME FC-4 LS service request.
 *       The nvme_fc_ls_req structure will fully describe the buffers for
 *       the request payload and where to place the response payload. The
 *       LLDD is to allocate an exchange, issue the LS request, obtain the
 *       LS response, and call the "done" routine specified in the request
 *       structure (argument to done is the ls request structure itself).
 *       Entrypoint is Mandatory.
 *
 * @fcp_io:  called to issue a FC-NVME I/O request.  The I/O may be for
 *       an admin queue or an i/o queue.  The nvmefc_fcp_req structure will
 *       fully describe the io: the buffer containing the FC-NVME CMD IU
 *       (which contains the SQE), the sg list for the payload if applicable,
 *       and the buffer to place the FC-NVME RSP IU into.  The LLDD will
 *       complete the i/o, indicating the amount of data transferred or
 *       any transport error, and call the "done" routine specified in the
 *       request structure (argument to done is the fcp request structure
 *       itself).
 *       Entrypoint is Mandatory.
 *
 * @ls_abort: called to request the LLDD to abort the indicated ls request.
 *       The call may return before the abort has completed. After aborting
 *       the request, the LLDD must still call the ls request done routine
 *       indicating an FC transport Aborted status.
 *       Entrypoint is Mandatory.
 *
 * @fcp_abort: called to request the LLDD to abort the indicated fcp request.
 *       The call may return before the abort has completed. After aborting
 *       the request, the LLDD must still call the fcp request done routine
 *       indicating an FC transport Aborted status.
 *       Entrypoint is Mandatory.
 *
 * @max_hw_queues:  indicates the maximum number of hw queues the LLDD
 *       supports for cpu affinitization.
 *       Value is Mandatory. Must be at least 1.
 *
 * @max_sgl_segments:  indicates the maximum number of sgl segments supported
 *       by the LLDD
 *       Value is Mandatory. Must be at least 1. Recommend at least 256.
 *
 * @max_dif_sgl_segments:  indicates the maximum number of sgl segments
 *       supported by the LLDD for DIF operations.
 *       Value is Mandatory. Must be at least 1. Recommend at least 256.
 *
 * @dma_boundary:  indicates the dma address boundary where dma mappings
 *       will be split across.
 *       Value is Mandatory. Typical value is 0xFFFFFFFF to split across
 *       4Gig address boundarys
 *
 * @local_priv_sz: The LLDD sets this field to the amount of additional
 *       memory that it would like fc nvme layer to allocate on the LLDD's
 *       behalf whenever a localport is allocated.  The additional memory
 *       area solely for the of the LLDD and its location is specified by
 *       the localport->private pointer.
 *       Value is Mandatory. Allowed to be zero.
 *
 * @remote_priv_sz: The LLDD sets this field to the amount of additional
 *       memory that it would like fc nvme layer to allocate on the LLDD's
 *       behalf whenever a remoteport is allocated.  The additional memory
 *       area solely for the of the LLDD and its location is specified by
 *       the remoteport->private pointer.
 *       Value is Mandatory. Allowed to be zero.
 *
 * @lsrqst_priv_sz: The LLDD sets this field to the amount of additional
 *       memory that it would like fc nvme layer to allocate on the LLDD's
 *       behalf whenever a ls request structure is allocated. The additional
 *       memory area solely for the of the LLDD and its location is
 *       specified by the ls_request->private pointer.
 *       Value is Mandatory. Allowed to be zero.
 *
 * @fcprqst_priv_sz: The LLDD sets this field to the amount of additional
 *       memory that it would like fc nvme layer to allocate on the LLDD's
 *       behalf whenever a fcp request structure is allocated. The additional
 *       memory area solely for the of the LLDD and its location is
 *       specified by the fcp_request->private pointer.
 *       Value is Mandatory. Allowed to be zero.
 */
struct nvme_fc_port_template {
	/* initiator-based functions */
	void	(*localport_delete)(struct nvme_fc_local_port *);
	void	(*remoteport_delete)(struct nvme_fc_remote_port *);
	int	(*create_queue)(struct nvme_fc_local_port *,
				unsigned int qidx, u16 qsize,
				void **handle);
	void	(*delete_queue)(struct nvme_fc_local_port *,
				unsigned int qidx, void *handle);
	int	(*ls_req)(struct nvme_fc_local_port *,
				struct nvme_fc_remote_port *,
				struct nvmefc_ls_req *);
	int	(*fcp_io)(struct nvme_fc_local_port *,
				struct nvme_fc_remote_port *,
				void *hw_queue_handle,
				struct nvmefc_fcp_req *);
	void	(*ls_abort)(struct nvme_fc_local_port *,
				struct nvme_fc_remote_port *,
				struct nvmefc_ls_req *);
	void	(*fcp_abort)(struct nvme_fc_local_port *,
				struct nvme_fc_remote_port *,
				void *hw_queue_handle,
				struct nvmefc_fcp_req *);

	u32	max_hw_queues;
	u16	max_sgl_segments;
	u16	max_dif_sgl_segments;
	u64	dma_boundary;

	/* sizes of additional private data for data structures */
	u32	local_priv_sz;
	u32	remote_priv_sz;
	u32	lsrqst_priv_sz;
	u32	fcprqst_priv_sz;
};


/*
 * Initiator/Host functions
 */

int nvme_fc_register_localport(struct nvme_fc_port_info *pinfo,
			struct nvme_fc_port_template *template,
			struct device *dev,
			struct nvme_fc_local_port **lport_p);

int nvme_fc_unregister_localport(struct nvme_fc_local_port *localport);

int nvme_fc_register_remoteport(struct nvme_fc_local_port *localport,
			struct nvme_fc_port_info *pinfo,
			struct nvme_fc_remote_port **rport_p);

int nvme_fc_unregister_remoteport(struct nvme_fc_remote_port *remoteport);

void nvme_fc_rescan_remoteport(struct nvme_fc_remote_port *remoteport);

int nvme_fc_set_remoteport_devloss(struct nvme_fc_remote_port *remoteport,
			u32 dev_loss_tmo);


/*
 * ***************  LLDD FC-NVME Target/Subsystem API ***************
 *
 *  For FC LLDD's that are the NVME Subsystem role
 *
 * ******************************************************************
 */

/**
 * struct nvmet_fc_port_info - port-specific ids and FC connection-specific
 *                             data element used during NVME Subsystem role
 *                             registrations
 *
 * Static fields describing the port being registered:
 * @node_name: FC WWNN for the port
 * @port_name: FC WWPN for the port
 *
 * Initialization values for dynamic port fields:
 * @port_id:      FC N_Port_ID currently assigned the port. Upper 8 bits must
 *                be set to 0.
 */
struct nvmet_fc_port_info {
	u64			node_name;
	u64			port_name;
	u32			port_id;
};


/**
 * struct nvmefc_tgt_ls_req - Structure used between LLDD and NVMET-FC
 *                            layer to represent the exchange context for
 *                            a FC-NVME Link Service (LS).
 *
 * The structure is allocated by the LLDD whenever a LS Request is received
 * from the FC link. The address of the structure is passed to the nvmet-fc
 * layer via the nvmet_fc_rcv_ls_req() call. The address of the structure
 * will be passed back to the LLDD when the response is to be transmit.
 * The LLDD is to use the address to map back to the LLDD exchange structure
 * which maintains information such as the targetport the LS was received
 * on, the remote FC NVME initiator that sent the LS, and any FC exchange
 * context.  Upon completion of the LS response transmit, the address of the
 * structure will be passed back to the LS rsp done() routine, allowing the
 * nvmet-fc layer to release dma resources. Upon completion of the done()
 * routine, no further access will be made by the nvmet-fc layer and the
 * LLDD can de-allocate the structure.
 *
 * Field initialization:
 *   At the time of the nvmet_fc_rcv_ls_req() call, there is no content that
 *     is valid in the structure.
 *
 *   When the structure is used for the LLDD->xmt_ls_rsp() call, the nvmet-fc
 *     layer will fully set the fields in order to specify the response
 *     payload buffer and its length as well as the done routine to be called
 *     upon compeletion of the transmit.  The nvmet-fc layer will also set a
 *     private pointer for its own use in the done routine.
 *
 * Values set by the NVMET-FC layer prior to calling the LLDD xmt_ls_rsp
 * entrypoint.
 * @rspbuf:   pointer to the LS response buffer
 * @rspdma:   PCI DMA address of the LS response buffer
 * @rsplen:   Length, in bytes, of the LS response buffer
 * @done:     The callback routine the LLDD is to invoke upon completion of
 *            transmitting the LS response. req argument is the pointer to
 *            the original ls request.
 * @nvmet_fc_private:  pointer to an internal NVMET-FC layer structure used
 *            as part of the NVMET-FC processing. The LLDD is not to access
 *            this pointer.
 */
struct nvmefc_tgt_ls_req {
	void		*rspbuf;
	dma_addr_t	rspdma;
	u16		rsplen;

	void (*done)(struct nvmefc_tgt_ls_req *req);
	void *nvmet_fc_private;		/* LLDD is not to access !! */
};

/* Operations that NVME-FC layer may request the LLDD to perform for FCP */
enum {
	NVMET_FCOP_READDATA	= 1,	/* xmt data to initiator */
	NVMET_FCOP_WRITEDATA	= 2,	/* xmt data from initiator */
	NVMET_FCOP_READDATA_RSP	= 3,	/* xmt data to initiator and send
					 * rsp as well
					 */
	NVMET_FCOP_RSP		= 4,	/* send rsp frame */
};

/**
 * struct nvmefc_tgt_fcp_req - Structure used between LLDD and NVMET-FC
 *                            layer to represent the exchange context and
 *                            the specific FC-NVME IU operation(s) to perform
 *                            for a FC-NVME FCP IO.
 *
 * Structure used between LLDD and nvmet-fc layer to represent the exchange
 * context for a FC-NVME FCP I/O operation (e.g. a nvme sqe, the sqe-related
 * memory transfers, and its assocated cqe transfer).
 *
 * The structure is allocated by the LLDD whenever a FCP CMD IU is received
 * from the FC link. The address of the structure is passed to the nvmet-fc
 * layer via the nvmet_fc_rcv_fcp_req() call. The address of the structure
 * will be passed back to the LLDD for the data operations and transmit of
 * the response. The LLDD is to use the address to map back to the LLDD
 * exchange structure which maintains information such as the targetport
 * the FCP I/O was received on, the remote FC NVME initiator that sent the
 * FCP I/O, and any FC exchange context.  Upon completion of the FCP target
 * operation, the address of the structure will be passed back to the FCP
 * op done() routine, allowing the nvmet-fc layer to release dma resources.
 * Upon completion of the done() routine for either RSP or ABORT ops, no
 * further access will be made by the nvmet-fc layer and the LLDD can
 * de-allocate the structure.
 *
 * Field initialization:
 *   At the time of the nvmet_fc_rcv_fcp_req() call, there is no content that
 *     is valid in the structure.
 *
 *   When the structure is used for an FCP target operation, the nvmet-fc
 *     layer will fully set the fields in order to specify the scattergather
 *     list, the transfer length, as well as the done routine to be called
 *     upon compeletion of the operation.  The nvmet-fc layer will also set a
 *     private pointer for its own use in the done routine.
 *
 * Values set by the NVMET-FC layer prior to calling the LLDD fcp_op
 * entrypoint.
 * @op:       Indicates the FCP IU operation to perform (see NVMET_FCOP_xxx)
 * @hwqid:    Specifies the hw queue index (0..N-1, where N is the
 *            max_hw_queues value from the LLD's nvmet_fc_target_template)
 *            that the operation is to use.
 * @offset:   Indicates the DATA_OUT/DATA_IN payload offset to be tranferred.
 *            Field is only valid on WRITEDATA, READDATA, or READDATA_RSP ops.
 * @timeout:  amount of time, in seconds, to wait for a response from the NVME
 *            host. A value of 0 is an infinite wait.
 *            Valid only for the following ops:
 *              WRITEDATA: caps the wait for data reception
 *              READDATA_RSP & RSP: caps wait for FCP_CONF reception (if used)
 * @transfer_length: the length, in bytes, of the DATA_OUT or DATA_IN payload
 *            that is to be transferred.
 *            Valid only for the WRITEDATA, READDATA, or READDATA_RSP ops.
 * @ba_rjt:   Contains the BA_RJT payload that is to be transferred.
 *            Valid only for the NVMET_FCOP_BA_RJT op.
 * @sg:       Scatter/gather list for the DATA_OUT/DATA_IN payload data.
 *            Valid only for the WRITEDATA, READDATA, or READDATA_RSP ops.
 * @sg_cnt:   Number of valid entries in the scatter/gather list.
 *            Valid only for the WRITEDATA, READDATA, or READDATA_RSP ops.
 * @rspaddr:  pointer to the FCP RSP IU buffer to be transmit
 *            Used by RSP and READDATA_RSP ops
 * @rspdma:   PCI DMA address of the FCP RSP IU buffer
 *            Used by RSP and READDATA_RSP ops
 * @rsplen:   Length, in bytes, of the FCP RSP IU buffer
 *            Used by RSP and READDATA_RSP ops
 * @done:     The callback routine the LLDD is to invoke upon completion of
 *            the operation. req argument is the pointer to the original
 *            FCP subsystem op request.
 * @nvmet_fc_private:  pointer to an internal NVMET-FC layer structure used
 *            as part of the NVMET-FC processing. The LLDD is not to
 *            reference this field.
 *
 * Values set by the LLDD indicating completion status of the FCP operation.
 * Must be set prior to calling the done() callback.
 * @transferred_length: amount of DATA_OUT payload data received by a
 *            a WRITEDATA operation. If not a WRITEDATA operation, value must
 *            be set to 0. Should equal transfer_length on success.
 * @fcp_error: status of the FCP operation. Must be 0 on success; on failure
 *            must be a NVME_SC_FC_xxxx value.
 */
struct nvmefc_tgt_fcp_req {
	u8			op;
	u16			hwqid;
	u32			offset;
	u32			timeout;
	u32			transfer_length;
	struct fc_ba_rjt	ba_rjt;
	struct scatterlist	*sg;
	int			sg_cnt;
	void			*rspaddr;
	dma_addr_t		rspdma;
	u16			rsplen;

	void (*done)(struct nvmefc_tgt_fcp_req *);

	void *nvmet_fc_private;		/* LLDD is not to access !! */

	u32			transferred_length;
	int			fcp_error;
};


/* Target Features (Bit fields) LLDD supports */
enum {
	NVMET_FCTGTFEAT_READDATA_RSP = (1 << 0),
		/* Bit 0: supports the NVMET_FCPOP_READDATA_RSP op, which
		 * sends (the last) Read Data sequence followed by the RSP
		 * sequence in one LLDD operation. Errors during Data
		 * sequence transmit must not allow RSP sequence to be sent.
		 */
};


/**
 * struct nvmet_fc_target_port - structure used between NVME-FC transport and
 *                 a LLDD to reference a local NVME subsystem port.
 *                 Allocated/created by the nvme_fc_register_targetport()
 *                 transport interface.
 *
 * Fields with static values for the port. Initialized by the
 * port_info struct supplied to the registration call.
 * @port_num:  NVME-FC transport subsytem port number
 * @node_name: FC WWNN for the port
 * @port_name: FC WWPN for the port
 * @private:   pointer to memory allocated alongside the local port
 *             structure that is specifically for the LLDD to use.
 *             The length of the buffer corresponds to the target_priv_sz
 *             value specified in the nvme_fc_target_template supplied by
 *             the LLDD.
 *
 * Fields with dynamic values. Values may change base on link state. LLDD
 * may reference fields directly to change them. Initialized by the
 * port_info struct supplied to the registration call.
 * @port_id:      FC N_Port_ID currently assigned the port. Upper 8 bits must
 *                be set to 0.
 * @port_state:   Operational state of the port.
 */
struct nvmet_fc_target_port {
	/* static/read-only fields */
	u32 port_num;
	u64 node_name;
	u64 port_name;

	void *private;

	/* dynamic fields */
	u32 port_id;
	enum nvme_fc_obj_state port_state;
} __aligned(sizeof(u64));	/* alignment for other things alloc'd with */


/**
 * struct nvmet_fc_target_template - structure containing static entrypoints
 *                 and operational parameters for an LLDD that supports NVME
 *                 subsystem behavior. Passed by reference in port
 *                 registrations. NVME-FC transport remembers template
 *                 reference and may access it during runtime operation.
 *
 * Subsystem/Target Transport Entrypoints/Parameters:
 *
 * @targetport_delete:  The LLDD initiates deletion of a targetport via
 *       nvmet_fc_unregister_targetport(). However, the teardown is
 *       asynchronous. This routine is called upon the completion of the
 *       teardown to inform the LLDD that the targetport has been deleted.
 *       Entrypoint is Mandatory.
 *
 * @xmt_ls_rsp:  Called to transmit the response to a FC-NVME FC-4 LS service.
 *       The nvmefc_tgt_ls_req structure is the same LLDD-supplied exchange
 *       structure specified in the nvmet_fc_rcv_ls_req() call made when
 *       the LS request was received.  The structure will fully describe
 *       the buffers for the response payload and the dma address of the
 *       payload. The LLDD is to transmit the response (or return a non-zero
 *       errno status), and upon completion of the transmit, call the
 *       "done" routine specified in the nvmefc_tgt_ls_req structure
 *       (argument to done is the ls reqwuest structure itself).
 *       After calling the done routine, the LLDD shall consider the
 *       LS handling complete and the nvmefc_tgt_ls_req structure may
 *       be freed/released.
 *       Entrypoint is Mandatory.
 *
 * @fcp_op:  Called to perform a data transfer or transmit a response.
 *       The nvmefc_tgt_fcp_req structure is the same LLDD-supplied
 *       exchange structure specified in the nvmet_fc_rcv_fcp_req() call
 *       made when the FCP CMD IU was received. The op field in the
 *       structure shall indicate the operation for the LLDD to perform
 *       relative to the io.
 *         NVMET_FCOP_READDATA operation: the LLDD is to send the
 *           payload data (described by sglist) to the host in 1 or
 *           more FC sequences (preferrably 1).  Note: the fc-nvme layer
 *           may call the READDATA operation multiple times for longer
 *           payloads.
 *         NVMET_FCOP_WRITEDATA operation: the LLDD is to receive the
 *           payload data (described by sglist) from the host via 1 or
 *           more FC sequences (preferrably 1). The LLDD is to generate
 *           the XFER_RDY IU(s) corresponding to the data being requested.
 *           Note: the FC-NVME layer may call the WRITEDATA operation
 *           multiple times for longer payloads.
 *         NVMET_FCOP_READDATA_RSP operation: the LLDD is to send the
 *           payload data (described by sglist) to the host in 1 or
 *           more FC sequences (preferrably 1). If an error occurs during
 *           payload data transmission, the LLDD is to set the
 *           nvmefc_tgt_fcp_req fcp_error and transferred_length field, then
 *           consider the operation complete. On error, the LLDD is to not
 *           transmit the FCP_RSP iu. If all payload data is transferred
 *           successfully, the LLDD is to update the nvmefc_tgt_fcp_req
 *           transferred_length field and may subsequently transmit the
 *           FCP_RSP iu payload (described by rspbuf, rspdma, rsplen).
 *           If FCP_CONF is supported, the LLDD is to await FCP_CONF
 *           reception to confirm the RSP reception by the host. The LLDD
 *           may retramsit the FCP_RSP iu if necessary per FC-NVME. Upon
 *           transmission of the FCP_RSP iu if FCP_CONF is not supported,
 *           or upon success/failure of FCP_CONF if it is supported, the
 *           LLDD is to set the nvmefc_tgt_fcp_req fcp_error field and
 *           consider the operation complete.
 *         NVMET_FCOP_RSP: the LLDD is to transmit the FCP_RSP iu payload
 *           (described by rspbuf, rspdma, rsplen). If FCP_CONF is
 *           supported, the LLDD is to await FCP_CONF reception to confirm
 *           the RSP reception by the host. The LLDD may retramsit the
 *           FCP_RSP iu if FCP_CONF is not received per FC-NVME. Upon
 *           transmission of the FCP_RSP iu if FCP_CONF is not supported,
 *           or upon success/failure of FCP_CONF if it is supported, the
 *           LLDD is to set the nvmefc_tgt_fcp_req fcp_error field and
 *           consider the operation complete.
 *       Upon completing the indicated operation, the LLDD is to set the
 *       status fields for the operation (tranferred_length and fcp_error
 *       status) in the request, then call the "done" routine
 *       indicated in the fcp request. After the operation completes,
 *       regardless of whether the FCP_RSP iu was successfully transmit,
 *       the LLDD-supplied exchange structure must remain valid until the
 *       transport calls the fcp_req_release() callback to return ownership
 *       of the exchange structure back to the LLDD so that it may be used
 *       for another fcp command.
 *       Note: when calling the done routine for READDATA or WRITEDATA
 *       operations, the fc-nvme layer may immediate convert, in the same
 *       thread and before returning to the LLDD, the fcp operation to
 *       the next operation for the fcp io and call the LLDDs fcp_op
 *       call again. If fields in the fcp request are to be accessed post
 *       the done call, the LLDD should save their values prior to calling
 *       the done routine, and inspect the save values after the done
 *       routine.
 *       Returns 0 on success, -<errno> on failure (Ex: -EIO)
 *       Entrypoint is Mandatory.
 *
 * @fcp_abort:  Called by the transport to abort an active command.
 *       The command may be in-between operations (nothing active in LLDD)
 *       or may have an active WRITEDATA operation pending. The LLDD is to
 *       initiate the ABTS process for the command and return from the
 *       callback. The ABTS does not need to be complete on the command.
 *       The fcp_abort callback inherently cannot fail. After the
 *       fcp_abort() callback completes, the transport will wait for any
 *       outstanding operation (if there was one) to complete, then will
 *       call the fcp_req_release() callback to return the command's
 *       exchange context back to the LLDD.
 *       Entrypoint is Mandatory.
 *
 * @fcp_req_release:  Called by the transport to return a nvmefc_tgt_fcp_req
 *       to the LLDD after all operations on the fcp operation are complete.
 *       This may be due to the command completing or upon completion of
 *       abort cleanup.
 *       Entrypoint is Mandatory.
 *
 * @defer_rcv:  Called by the transport to signal the LLLD that it has
 *       begun processing of a previously received NVME CMD IU. The LLDD
 *       is now free to re-use the rcv buffer associated with the
 *       nvmefc_tgt_fcp_req.
 *       Entrypoint is Optional.
 *
 * @max_hw_queues:  indicates the maximum number of hw queues the LLDD
 *       supports for cpu affinitization.
 *       Value is Mandatory. Must be at least 1.
 *
 * @max_sgl_segments:  indicates the maximum number of sgl segments supported
 *       by the LLDD
 *       Value is Mandatory. Must be at least 1. Recommend at least 256.
 *
 * @max_dif_sgl_segments:  indicates the maximum number of sgl segments
 *       supported by the LLDD for DIF operations.
 *       Value is Mandatory. Must be at least 1. Recommend at least 256.
 *
 * @dma_boundary:  indicates the dma address boundary where dma mappings
 *       will be split across.
 *       Value is Mandatory. Typical value is 0xFFFFFFFF to split across
 *       4Gig address boundarys
 *
 * @target_features: The LLDD sets bits in this field to correspond to
 *       optional features that are supported by the LLDD.
 *       Refer to the NVMET_FCTGTFEAT_xxx values.
 *       Value is Mandatory. Allowed to be zero.
 *
 * @target_priv_sz: The LLDD sets this field to the amount of additional
 *       memory that it would like fc nvme layer to allocate on the LLDD's
 *       behalf whenever a targetport is allocated.  The additional memory
 *       area solely for the of the LLDD and its location is specified by
 *       the targetport->private pointer.
 *       Value is Mandatory. Allowed to be zero.
 */
struct nvmet_fc_target_template {
	void (*targetport_delete)(struct nvmet_fc_target_port *tgtport);
	int (*xmt_ls_rsp)(struct nvmet_fc_target_port *tgtport,
				struct nvmefc_tgt_ls_req *tls_req);
	int (*fcp_op)(struct nvmet_fc_target_port *tgtport,
				struct nvmefc_tgt_fcp_req *fcpreq);
	void (*fcp_abort)(struct nvmet_fc_target_port *tgtport,
				struct nvmefc_tgt_fcp_req *fcpreq);
	void (*fcp_req_release)(struct nvmet_fc_target_port *tgtport,
				struct nvmefc_tgt_fcp_req *fcpreq);
	void (*defer_rcv)(struct nvmet_fc_target_port *tgtport,
				struct nvmefc_tgt_fcp_req *fcpreq);

	u32	max_hw_queues;
	u16	max_sgl_segments;
	u16	max_dif_sgl_segments;
	u64	dma_boundary;

	u32	target_features;

	u32	target_priv_sz;
};


int nvmet_fc_register_targetport(struct nvmet_fc_port_info *portinfo,
			struct nvmet_fc_target_template *template,
			struct device *dev,
			struct nvmet_fc_target_port **tgtport_p);

int nvmet_fc_unregister_targetport(struct nvmet_fc_target_port *tgtport);

int nvmet_fc_rcv_ls_req(struct nvmet_fc_target_port *tgtport,
			struct nvmefc_tgt_ls_req *lsreq,
			void *lsreqbuf, u32 lsreqbuf_len);

int nvmet_fc_rcv_fcp_req(struct nvmet_fc_target_port *tgtport,
			struct nvmefc_tgt_fcp_req *fcpreq,
			void *cmdiubuf, u32 cmdiubuf_len);

void nvmet_fc_rcv_fcp_abort(struct nvmet_fc_target_port *tgtport,
			struct nvmefc_tgt_fcp_req *fcpreq);

#endif /* _NVME_FC_DRIVER_H */