aboutsummaryrefslogtreecommitdiff
path: root/drivers/scsi/ibmvscsi/ibmvstgt.c
blob: bf9eca84516658b5a6ad00527e665e4b2457672d (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
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
1001
/*
 * IBM eServer i/pSeries Virtual SCSI Target Driver
 * Copyright (C) 2003-2005 Dave Boutcher (boutcher@us.ibm.com) IBM Corp.
 *			   Santiago Leon (santil@us.ibm.com) IBM Corp.
 *			   Linda Xie (lxie@us.ibm.com) IBM Corp.
 *
 * Copyright (C) 2005-2006 FUJITA Tomonori <tomof@acm.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_transport_srp.h>
#include <scsi/scsi_tgt.h>
#include <scsi/libsrp.h>
#include <asm/hvcall.h>
#include <asm/iommu.h>
#include <asm/prom.h>
#include <asm/vio.h>

#include "ibmvscsi.h"

#define	INITIAL_SRP_LIMIT	16
#define	DEFAULT_MAX_SECTORS	256

#define	TGT_NAME	"ibmvstgt"

/*
 * Hypervisor calls.
 */
#define h_copy_rdma(l, sa, sb, da, db) \
			plpar_hcall_norets(H_COPY_RDMA, l, sa, sb, da, db)
#define h_send_crq(ua, l, h) \
			plpar_hcall_norets(H_SEND_CRQ, ua, l, h)
#define h_reg_crq(ua, tok, sz)\
			plpar_hcall_norets(H_REG_CRQ, ua, tok, sz);
#define h_free_crq(ua) \
			plpar_hcall_norets(H_FREE_CRQ, ua);

/* tmp - will replace with SCSI logging stuff */
#define eprintk(fmt, args...)					\
do {								\
	printk("%s(%d) " fmt, __func__, __LINE__, ##args);	\
} while (0)
/* #define dprintk eprintk */
#define dprintk(fmt, args...)

struct vio_port {
	struct vio_dev *dma_dev;

	struct crq_queue crq_queue;
	struct work_struct crq_work;

	unsigned long liobn;
	unsigned long riobn;
	struct srp_target *target;

	struct srp_rport *rport;
};

static struct workqueue_struct *vtgtd;
static struct scsi_transport_template *ibmvstgt_transport_template;

/*
 * These are fixed for the system and come from the Open Firmware device tree.
 * We just store them here to save getting them every time.
 */
static char system_id[64] = "";
static char partition_name[97] = "UNKNOWN";
static unsigned int partition_number = -1;

static struct vio_port *target_to_port(struct srp_target *target)
{
	return (struct vio_port *) target->ldata;
}

static inline union viosrp_iu *vio_iu(struct iu_entry *iue)
{
	return (union viosrp_iu *) (iue->sbuf->buf);
}

static int send_iu(struct iu_entry *iue, uint64_t length, uint8_t format)
{
	struct srp_target *target = iue->target;
	struct vio_port *vport = target_to_port(target);
	long rc, rc1;
	union {
		struct viosrp_crq cooked;
		uint64_t raw[2];
	} crq;

	/* First copy the SRP */
	rc = h_copy_rdma(length, vport->liobn, iue->sbuf->dma,
			 vport->riobn, iue->remote_token);

	if (rc)
		eprintk("Error %ld transferring data\n", rc);

	crq.cooked.valid = 0x80;
	crq.cooked.format = format;
	crq.cooked.reserved = 0x00;
	crq.cooked.timeout = 0x00;
	crq.cooked.IU_length = length;
	crq.cooked.IU_data_ptr = vio_iu(iue)->srp.rsp.tag;

	if (rc == 0)
		crq.cooked.status = 0x99;	/* Just needs to be non-zero */
	else
		crq.cooked.status = 0x00;

	rc1 = h_send_crq(vport->dma_dev->unit_address, crq.raw[0], crq.raw[1]);

	if (rc1) {
		eprintk("%ld sending response\n", rc1);
		return rc1;
	}

	return rc;
}

#define SRP_RSP_SENSE_DATA_LEN	18

static int send_rsp(struct iu_entry *iue, struct scsi_cmnd *sc,
		    unsigned char status, unsigned char asc)
{
	union viosrp_iu *iu = vio_iu(iue);
	uint64_t tag = iu->srp.rsp.tag;

	/* If the linked bit is on and status is good */
	if (test_bit(V_LINKED, &iue->flags) && (status == NO_SENSE))
		status = 0x10;

	memset(iu, 0, sizeof(struct srp_rsp));
	iu->srp.rsp.opcode = SRP_RSP;
	iu->srp.rsp.req_lim_delta = 1;
	iu->srp.rsp.tag = tag;

	if (test_bit(V_DIOVER, &iue->flags))
		iu->srp.rsp.flags |= SRP_RSP_FLAG_DIOVER;

	iu->srp.rsp.data_in_res_cnt = 0;
	iu->srp.rsp.data_out_res_cnt = 0;

	iu->srp.rsp.flags &= ~SRP_RSP_FLAG_RSPVALID;

	iu->srp.rsp.resp_data_len = 0;
	iu->srp.rsp.status = status;
	if (status) {
		uint8_t *sense = iu->srp.rsp.data;

		if (sc) {
			iu->srp.rsp.flags |= SRP_RSP_FLAG_SNSVALID;
			iu->srp.rsp.sense_data_len = SCSI_SENSE_BUFFERSIZE;
			memcpy(sense, sc->sense_buffer, SCSI_SENSE_BUFFERSIZE);
		} else {
			iu->srp.rsp.status = SAM_STAT_CHECK_CONDITION;
			iu->srp.rsp.flags |= SRP_RSP_FLAG_SNSVALID;
			iu->srp.rsp.sense_data_len = SRP_RSP_SENSE_DATA_LEN;

			/* Valid bit and 'current errors' */
			sense[0] = (0x1 << 7 | 0x70);
			/* Sense key */
			sense[2] = status;
			/* Additional sense length */
			sense[7] = 0xa;	/* 10 bytes */
			/* Additional sense code */
			sense[12] = asc;
		}
	}

	send_iu(iue, sizeof(iu->srp.rsp) + SRP_RSP_SENSE_DATA_LEN,
		VIOSRP_SRP_FORMAT);

	return 0;
}

static void handle_cmd_queue(struct srp_target *target)
{
	struct Scsi_Host *shost = target->shost;
	struct srp_rport *rport = target_to_port(target)->rport;
	struct iu_entry *iue;
	struct srp_cmd *cmd;
	unsigned long flags;
	int err;

retry:
	spin_lock_irqsave(&target->lock, flags);

	list_for_each_entry(iue, &target->cmd_queue, ilist) {
		if (!test_and_set_bit(V_FLYING, &iue->flags)) {
			spin_unlock_irqrestore(&target->lock, flags);
			cmd = iue->sbuf->buf;
			err = srp_cmd_queue(shost, cmd, iue,
					    (unsigned long)rport, 0);
			if (err) {
				eprintk("cannot queue cmd %p %d\n", cmd, err);
				srp_iu_put(iue);
			}
			goto retry;
		}
	}

	spin_unlock_irqrestore(&target->lock, flags);
}

static int ibmvstgt_rdma(struct scsi_cmnd *sc, struct scatterlist *sg, int nsg,
			 struct srp_direct_buf *md, int nmd,
			 enum dma_data_direction dir, unsigned int rest)
{
	struct iu_entry *iue = (struct iu_entry *) sc->SCp.ptr;
	struct srp_target *target = iue->target;
	struct vio_port *vport = target_to_port(target);
	dma_addr_t token;
	long err;
	unsigned int done = 0;
	int i, sidx, soff;

	sidx = soff = 0;
	token = sg_dma_address(sg + sidx);

	for (i = 0; i < nmd && rest; i++) {
		unsigned int mdone, mlen;

		mlen = min(rest, md[i].len);
		for (mdone = 0; mlen;) {
			int slen = min(sg_dma_len(sg + sidx) - soff, mlen);

			if (dir == DMA_TO_DEVICE)
				err = h_copy_rdma(slen,
						  vport->riobn,
						  md[i].va + mdone,
						  vport->liobn,
						  token + soff);
			else
				err = h_copy_rdma(slen,
						  vport->liobn,
						  token + soff,
						  vport->riobn,
						  md[i].va + mdone);

			if (err != H_SUCCESS) {
				eprintk("rdma error %d %d %ld\n", dir, slen, err);
				return -EIO;
			}

			mlen -= slen;
			mdone += slen;
			soff += slen;
			done += slen;

			if (soff == sg_dma_len(sg + sidx)) {
				sidx++;
				soff = 0;
				token = sg_dma_address(sg + sidx);

				if (sidx > nsg) {
					eprintk("out of sg %p %d %d\n",
						iue, sidx, nsg);
					return -EIO;
				}
			}
		};

		rest -= mlen;
	}
	return 0;
}

static int ibmvstgt_cmd_done(struct scsi_cmnd *sc,
			     void (*done)(struct scsi_cmnd *))
{
	unsigned long flags;
	struct iu_entry *iue = (struct iu_entry *) sc->SCp.ptr;
	struct srp_target *target = iue->target;
	int err = 0;

	dprintk("%p %p %x %u\n", iue, target, vio_iu(iue)->srp.cmd.cdb[0],
		scsi_sg_count(sc));

	if (scsi_sg_count(sc))
		err = srp_transfer_data(sc, &vio_iu(iue)->srp.cmd, ibmvstgt_rdma, 1, 1);

	spin_lock_irqsave(&target->lock, flags);
	list_del(&iue->ilist);
	spin_unlock_irqrestore(&target->lock, flags);

	if (err|| sc->result != SAM_STAT_GOOD) {
		eprintk("operation failed %p %d %x\n",
			iue, sc->result, vio_iu(iue)->srp.cmd.cdb[0]);
		send_rsp(iue, sc, HARDWARE_ERROR, 0x00);
	} else
		send_rsp(iue, sc, NO_SENSE, 0x00);

	done(sc);
	srp_iu_put(iue);
	return 0;
}

int send_adapter_info(struct iu_entry *iue,
		      dma_addr_t remote_buffer, uint16_t length)
{
	struct srp_target *target = iue->target;
	struct vio_port *vport = target_to_port(target);
	struct Scsi_Host *shost = target->shost;
	dma_addr_t data_token;
	struct mad_adapter_info_data *info;
	int err;

	info = dma_alloc_coherent(target->dev, sizeof(*info), &data_token,
				  GFP_KERNEL);
	if (!info) {
		eprintk("bad dma_alloc_coherent %p\n", target);
		return 1;
	}

	/* Get remote info */
	err = h_copy_rdma(sizeof(*info), vport->riobn, remote_buffer,
			  vport->liobn, data_token);
	if (err == H_SUCCESS) {
		dprintk("Client connect: %s (%d)\n",
			info->partition_name, info->partition_number);
	}

	memset(info, 0, sizeof(*info));

	strcpy(info->srp_version, "16.a");
	strncpy(info->partition_name, partition_name,
		sizeof(info->partition_name));
	info->partition_number = partition_number;
	info->mad_version = 1;
	info->os_type = 2;
	info->port_max_txu[0] = shost->hostt->max_sectors << 9;

	/* Send our info to remote */
	err = h_copy_rdma(sizeof(*info), vport->liobn, data_token,
			  vport->riobn, remote_buffer);

	dma_free_coherent(target->dev, sizeof(*info), info, data_token);

	if (err != H_SUCCESS) {
		eprintk("Error sending adapter info %d\n", err);
		return 1;
	}

	return 0;
}

static void process_login(struct iu_entry *iue)
{
	union viosrp_iu *iu = vio_iu(iue);
	struct srp_login_rsp *rsp = &iu->srp.login_rsp;
	uint64_t tag = iu->srp.rsp.tag;
	struct Scsi_Host *shost = iue->target->shost;
	struct srp_target *target = host_to_srp_target(shost);
	struct vio_port *vport = target_to_port(target);
	struct srp_rport_identifiers ids;

	memset(&ids, 0, sizeof(ids));
	sprintf(ids.port_id, "%x", vport->dma_dev->unit_address);
	ids.roles = SRP_RPORT_ROLE_INITIATOR;
	if (!vport->rport)
		vport->rport = srp_rport_add(shost, &ids);

	/* TODO handle case that requested size is wrong and
	 * buffer format is wrong
	 */
	memset(iu, 0, sizeof(struct srp_login_rsp));
	rsp->opcode = SRP_LOGIN_RSP;
	rsp->req_lim_delta = INITIAL_SRP_LIMIT;
	rsp->tag = tag;
	rsp->max_it_iu_len = sizeof(union srp_iu);
	rsp->max_ti_iu_len = sizeof(union srp_iu);
	/* direct and indirect */
	rsp->buf_fmt = SRP_BUF_FORMAT_DIRECT | SRP_BUF_FORMAT_INDIRECT;

	send_iu(iue, sizeof(*rsp), VIOSRP_SRP_FORMAT);
}

static inline void queue_cmd(struct iu_entry *iue)
{
	struct srp_target *target = iue->target;
	unsigned long flags;

	spin_lock_irqsave(&target->lock, flags);
	list_add_tail(&iue->ilist, &target->cmd_queue);
	spin_unlock_irqrestore(&target->lock, flags);
}

static int process_tsk_mgmt(struct iu_entry *iue)
{
	union viosrp_iu *iu = vio_iu(iue);
	int fn;

	dprintk("%p %u\n", iue, iu->srp.tsk_mgmt.tsk_mgmt_func);

	switch (iu->srp.tsk_mgmt.tsk_mgmt_func) {
	case SRP_TSK_ABORT_TASK:
		fn = ABORT_TASK;
		break;
	case SRP_TSK_ABORT_TASK_SET:
		fn = ABORT_TASK_SET;
		break;
	case SRP_TSK_CLEAR_TASK_SET:
		fn = CLEAR_TASK_SET;
		break;
	case SRP_TSK_LUN_RESET:
		fn = LOGICAL_UNIT_RESET;
		break;
	case SRP_TSK_CLEAR_ACA:
		fn = CLEAR_ACA;
		break;
	default:
		fn = 0;
	}
	if (fn)
		scsi_tgt_tsk_mgmt_request(iue->target->shost,
					  (unsigned long)iue->target->shost,
					  fn,
					  iu->srp.tsk_mgmt.task_tag,
					  (struct scsi_lun *) &iu->srp.tsk_mgmt.lun,
					  iue);
	else
		send_rsp(iue, NULL, ILLEGAL_REQUEST, 0x20);

	return !fn;
}

static int process_mad_iu(struct iu_entry *iue)
{
	union viosrp_iu *iu = vio_iu(iue);
	struct viosrp_adapter_info *info;
	struct viosrp_host_config *conf;

	switch (iu->mad.empty_iu.common.type) {
	case VIOSRP_EMPTY_IU_TYPE:
		eprintk("%s\n", "Unsupported EMPTY MAD IU");
		break;
	case VIOSRP_ERROR_LOG_TYPE:
		eprintk("%s\n", "Unsupported ERROR LOG MAD IU");
		iu->mad.error_log.common.status = 1;
		send_iu(iue, sizeof(iu->mad.error_log),	VIOSRP_MAD_FORMAT);
		break;
	case VIOSRP_ADAPTER_INFO_TYPE:
		info = &iu->mad.adapter_info;
		info->common.status = send_adapter_info(iue, info->buffer,
							info->common.length);
		send_iu(iue, sizeof(*info), VIOSRP_MAD_FORMAT);
		break;
	case VIOSRP_HOST_CONFIG_TYPE:
		conf = &iu->mad.host_config;
		conf->common.status = 1;
		send_iu(iue, sizeof(*conf), VIOSRP_MAD_FORMAT);
		break;
	default:
		eprintk("Unknown type %u\n", iu->srp.rsp.opcode);
	}

	return 1;
}

static int process_srp_iu(struct iu_entry *iue)
{
	union viosrp_iu *iu = vio_iu(iue);
	int done = 1;
	u8 opcode = iu->srp.rsp.opcode;

	switch (opcode) {
	case SRP_LOGIN_REQ:
		process_login(iue);
		break;
	case SRP_TSK_MGMT:
		done = process_tsk_mgmt(iue);
		break;
	case SRP_CMD:
		queue_cmd(iue);
		done = 0;
		break;
	case SRP_LOGIN_RSP:
	case SRP_I_LOGOUT:
	case SRP_T_LOGOUT:
	case SRP_RSP:
	case SRP_CRED_REQ:
	case SRP_CRED_RSP:
	case SRP_AER_REQ:
	case SRP_AER_RSP:
		eprintk("Unsupported type %u\n", opcode);
		break;
	default:
		eprintk("Unknown type %u\n", opcode);
	}

	return done;
}

static void process_iu(struct viosrp_crq *crq, struct srp_target *target)
{
	struct vio_port *vport = target_to_port(target);
	struct iu_entry *iue;
	long err;
	int done = 1;

	iue = srp_iu_get(target);
	if (!iue) {
		eprintk("Error getting IU from pool, %p\n", target);
		return;
	}

	iue->remote_token = crq->IU_data_ptr;

	err = h_copy_rdma(crq->IU_length, vport->riobn,
			  iue->remote_token, vport->liobn, iue->sbuf->dma);

	if (err != H_SUCCESS) {
		eprintk("%ld transferring data error %p\n", err, iue);
		goto out;
	}

	if (crq->format == VIOSRP_MAD_FORMAT)
		done = process_mad_iu(iue);
	else
		done = process_srp_iu(iue);
out:
	if (done)
		srp_iu_put(iue);
}

static irqreturn_t ibmvstgt_interrupt(int dummy, void *data)
{
	struct srp_target *target = data;
	struct vio_port *vport = target_to_port(target);

	vio_disable_interrupts(vport->dma_dev);
	queue_work(vtgtd, &vport->crq_work);

	return IRQ_HANDLED;
}

static int crq_queue_create(struct crq_queue *queue, struct srp_target *target)
{
	int err;
	struct vio_port *vport = target_to_port(target);

	queue->msgs = (struct viosrp_crq *) get_zeroed_page(GFP_KERNEL);
	if (!queue->msgs)
		goto malloc_failed;
	queue->size = PAGE_SIZE / sizeof(*queue->msgs);

	queue->msg_token = dma_map_single(target->dev, queue->msgs,
					  queue->size * sizeof(*queue->msgs),
					  DMA_BIDIRECTIONAL);

	if (dma_mapping_error(target->dev, queue->msg_token))
		goto map_failed;

	err = h_reg_crq(vport->dma_dev->unit_address, queue->msg_token,
			PAGE_SIZE);

	/* If the adapter was left active for some reason (like kexec)
	 * try freeing and re-registering
	 */
	if (err == H_RESOURCE) {
	    do {
		err = h_free_crq(vport->dma_dev->unit_address);
	    } while (err == H_BUSY || H_IS_LONG_BUSY(err));

	    err = h_reg_crq(vport->dma_dev->unit_address, queue->msg_token,
			    PAGE_SIZE);
	}

	if (err != H_SUCCESS && err != 2) {
		eprintk("Error 0x%x opening virtual adapter\n", err);
		goto reg_crq_failed;
	}

	err = request_irq(vport->dma_dev->irq, &ibmvstgt_interrupt,
			  IRQF_DISABLED, "ibmvstgt", target);
	if (err)
		goto req_irq_failed;

	vio_enable_interrupts(vport->dma_dev);

	h_send_crq(vport->dma_dev->unit_address, 0xC001000000000000, 0);

	queue->cur = 0;
	spin_lock_init(&queue->lock);

	return 0;

req_irq_failed:
	do {
		err = h_free_crq(vport->dma_dev->unit_address);
	} while (err == H_BUSY || H_IS_LONG_BUSY(err));

reg_crq_failed:
	dma_unmap_single(target->dev, queue->msg_token,
			 queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
map_failed:
	free_page((unsigned long) queue->msgs);

malloc_failed:
	return -ENOMEM;
}

static void crq_queue_destroy(struct srp_target *target)
{
	struct vio_port *vport = target_to_port(target);
	struct crq_queue *queue = &vport->crq_queue;
	int err;

	free_irq(vport->dma_dev->irq, target);
	do {
		err = h_free_crq(vport->dma_dev->unit_address);
	} while (err == H_BUSY || H_IS_LONG_BUSY(err));

	dma_unmap_single(target->dev, queue->msg_token,
			 queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);

	free_page((unsigned long) queue->msgs);
}

static void process_crq(struct viosrp_crq *crq,	struct srp_target *target)
{
	struct vio_port *vport = target_to_port(target);
	dprintk("%x %x\n", crq->valid, crq->format);

	switch (crq->valid) {
	case 0xC0:
		/* initialization */
		switch (crq->format) {
		case 0x01:
			h_send_crq(vport->dma_dev->unit_address,
				   0xC002000000000000, 0);
			break;
		case 0x02:
			break;
		default:
			eprintk("Unknown format %u\n", crq->format);
		}
		break;
	case 0xFF:
		/* transport event */
		break;
	case 0x80:
		/* real payload */
		switch (crq->format) {
		case VIOSRP_SRP_FORMAT:
		case VIOSRP_MAD_FORMAT:
			process_iu(crq, target);
			break;
		case VIOSRP_OS400_FORMAT:
		case VIOSRP_AIX_FORMAT:
		case VIOSRP_LINUX_FORMAT:
		case VIOSRP_INLINE_FORMAT:
			eprintk("Unsupported format %u\n", crq->format);
			break;
		default:
			eprintk("Unknown format %u\n", crq->format);
		}
		break;
	default:
		eprintk("unknown message type 0x%02x!?\n", crq->valid);
	}
}

static inline struct viosrp_crq *next_crq(struct crq_queue *queue)
{
	struct viosrp_crq *crq;
	unsigned long flags;

	spin_lock_irqsave(&queue->lock, flags);
	crq = &queue->msgs[queue->cur];
	if (crq->valid & 0x80) {
		if (++queue->cur == queue->size)
			queue->cur = 0;
	} else
		crq = NULL;
	spin_unlock_irqrestore(&queue->lock, flags);

	return crq;
}

static void handle_crq(struct work_struct *work)
{
	struct vio_port *vport = container_of(work, struct vio_port, crq_work);
	struct srp_target *target = vport->target;
	struct viosrp_crq *crq;
	int done = 0;

	while (!done) {
		while ((crq = next_crq(&vport->crq_queue)) != NULL) {
			process_crq(crq, target);
			crq->valid = 0x00;
		}

		vio_enable_interrupts(vport->dma_dev);

		crq = next_crq(&vport->crq_queue);
		if (crq) {
			vio_disable_interrupts(vport->dma_dev);
			process_crq(crq, target);
			crq->valid = 0x00;
		} else
			done = 1;
	}

	handle_cmd_queue(target);
}


static int ibmvstgt_eh_abort_handler(struct scsi_cmnd *sc)
{
	unsigned long flags;
	struct iu_entry *iue = (struct iu_entry *) sc->SCp.ptr;
	struct srp_target *target = iue->target;

	dprintk("%p %p %x\n", iue, target, vio_iu(iue)->srp.cmd.cdb[0]);

	spin_lock_irqsave(&target->lock, flags);
	list_del(&iue->ilist);
	spin_unlock_irqrestore(&target->lock, flags);

	srp_iu_put(iue);

	return 0;
}

static int ibmvstgt_tsk_mgmt_response(struct Scsi_Host *shost,
				      u64 itn_id, u64 mid, int result)
{
	struct iu_entry *iue = (struct iu_entry *) ((void *) mid);
	union viosrp_iu *iu = vio_iu(iue);
	unsigned char status, asc;

	eprintk("%p %d\n", iue, result);
	status = NO_SENSE;
	asc = 0;

	switch (iu->srp.tsk_mgmt.tsk_mgmt_func) {
	case SRP_TSK_ABORT_TASK:
		asc = 0x14;
		if (result)
			status = ABORTED_COMMAND;
		break;
	default:
		break;
	}

	send_rsp(iue, NULL, status, asc);
	srp_iu_put(iue);

	return 0;
}

static int ibmvstgt_it_nexus_response(struct Scsi_Host *shost, u64 itn_id,
				      int result)
{
	struct srp_target *target = host_to_srp_target(shost);
	struct vio_port *vport = target_to_port(target);

	if (result) {
		eprintk("%p %d\n", shost, result);
		srp_rport_del(vport->rport);
		vport->rport = NULL;
	}
	return 0;
}

static ssize_t system_id_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%s\n", system_id);
}

static ssize_t partition_number_show(struct device *dev,
				     struct device_attribute *attr, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%x\n", partition_number);
}

static ssize_t unit_address_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
{
	struct Scsi_Host *shost = class_to_shost(dev);
	struct srp_target *target = host_to_srp_target(shost);
	struct vio_port *vport = target_to_port(target);
	return snprintf(buf, PAGE_SIZE, "%x\n", vport->dma_dev->unit_address);
}

static DEVICE_ATTR(system_id, S_IRUGO, system_id_show, NULL);
static DEVICE_ATTR(partition_number, S_IRUGO, partition_number_show, NULL);
static DEVICE_ATTR(unit_address, S_IRUGO, unit_address_show, NULL);

static struct device_attribute *ibmvstgt_attrs[] = {
	&dev_attr_system_id,
	&dev_attr_partition_number,
	&dev_attr_unit_address,
	NULL,
};

static struct scsi_host_template ibmvstgt_sht = {
	.name			= TGT_NAME,
	.module			= THIS_MODULE,
	.can_queue		= INITIAL_SRP_LIMIT,
	.sg_tablesize		= SG_ALL,
	.use_clustering		= DISABLE_CLUSTERING,
	.max_sectors		= DEFAULT_MAX_SECTORS,
	.transfer_response	= ibmvstgt_cmd_done,
	.eh_abort_handler	= ibmvstgt_eh_abort_handler,
	.shost_attrs		= ibmvstgt_attrs,
	.proc_name		= TGT_NAME,
	.supported_mode		= MODE_TARGET,
};

static int ibmvstgt_probe(struct vio_dev *dev, const struct vio_device_id *id)
{
	struct Scsi_Host *shost;
	struct srp_target *target;
	struct vio_port *vport;
	unsigned int *dma, dma_size;
	int err = -ENOMEM;

	vport = kzalloc(sizeof(struct vio_port), GFP_KERNEL);
	if (!vport)
		return err;
	shost = scsi_host_alloc(&ibmvstgt_sht, sizeof(struct srp_target));
	if (!shost)
		goto free_vport;
	shost->transportt = ibmvstgt_transport_template;

	target = host_to_srp_target(shost);
	target->shost = shost;
	vport->dma_dev = dev;
	target->ldata = vport;
	vport->target = target;
	err = srp_target_alloc(target, &dev->dev, INITIAL_SRP_LIMIT,
			       SRP_MAX_IU_LEN);
	if (err)
		goto put_host;

	dma = (unsigned int *) vio_get_attribute(dev, "ibm,my-dma-window",
						 &dma_size);
	if (!dma || dma_size != 40) {
		eprintk("Couldn't get window property %d\n", dma_size);
		err = -EIO;
		goto free_srp_target;
	}
	vport->liobn = dma[0];
	vport->riobn = dma[5];

	INIT_WORK(&vport->crq_work, handle_crq);

	err = scsi_add_host(shost, target->dev);
	if (err)
		goto free_srp_target;

	err = scsi_tgt_alloc_queue(shost);
	if (err)
		goto remove_host;

	err = crq_queue_create(&vport->crq_queue, target);
	if (err)
		goto free_queue;

	return 0;
free_queue:
	scsi_tgt_free_queue(shost);
remove_host:
	scsi_remove_host(shost);
free_srp_target:
	srp_target_free(target);
put_host:
	scsi_host_put(shost);
free_vport:
	kfree(vport);
	return err;
}

static int ibmvstgt_remove(struct vio_dev *dev)
{
	struct srp_target *target = dev_get_drvdata(&dev->dev);
	struct Scsi_Host *shost = target->shost;
	struct vio_port *vport = target->ldata;

	crq_queue_destroy(target);
	srp_remove_host(shost);
	scsi_remove_host(shost);
	scsi_tgt_free_queue(shost);
	srp_target_free(target);
	kfree(vport);
	scsi_host_put(shost);
	return 0;
}

static struct vio_device_id ibmvstgt_device_table[] = {
	{"v-scsi-host", "IBM,v-scsi-host"},
	{"",""}
};

MODULE_DEVICE_TABLE(vio, ibmvstgt_device_table);

static struct vio_driver ibmvstgt_driver = {
	.id_table = ibmvstgt_device_table,
	.probe = ibmvstgt_probe,
	.remove = ibmvstgt_remove,
	.name = "ibmvscsis",
};

static int get_system_info(void)
{
	struct device_node *rootdn;
	const char *id, *model, *name;
	const unsigned int *num;

	rootdn = of_find_node_by_path("/");
	if (!rootdn)
		return -ENOENT;

	model = of_get_property(rootdn, "model", NULL);
	id = of_get_property(rootdn, "system-id", NULL);
	if (model && id)
		snprintf(system_id, sizeof(system_id), "%s-%s", model, id);

	name = of_get_property(rootdn, "ibm,partition-name", NULL);
	if (name)
		strncpy(partition_name, name, sizeof(partition_name));

	num = of_get_property(rootdn, "ibm,partition-no", NULL);
	if (num)
		partition_number = *num;

	of_node_put(rootdn);
	return 0;
}

static struct srp_function_template ibmvstgt_transport_functions = {
	.tsk_mgmt_response = ibmvstgt_tsk_mgmt_response,
	.it_nexus_response = ibmvstgt_it_nexus_response,
};

static int __init ibmvstgt_init(void)
{
	int err = -ENOMEM;

	printk("IBM eServer i/pSeries Virtual SCSI Target Driver\n");

	ibmvstgt_transport_template =
		srp_attach_transport(&ibmvstgt_transport_functions);
	if (!ibmvstgt_transport_template)
		return err;

	vtgtd = create_workqueue("ibmvtgtd");
	if (!vtgtd)
		goto release_transport;

	err = get_system_info();
	if (err)
		goto destroy_wq;

	err = vio_register_driver(&ibmvstgt_driver);
	if (err)
		goto destroy_wq;

	return 0;
destroy_wq:
	destroy_workqueue(vtgtd);
release_transport:
	srp_release_transport(ibmvstgt_transport_template);
	return err;
}

static void __exit ibmvstgt_exit(void)
{
	printk("Unregister IBM virtual SCSI driver\n");

	destroy_workqueue(vtgtd);
	vio_unregister_driver(&ibmvstgt_driver);
	srp_release_transport(ibmvstgt_transport_template);
}

MODULE_DESCRIPTION("IBM Virtual SCSI Target");
MODULE_AUTHOR("Santiago Leon");
MODULE_LICENSE("GPL");

module_init(ibmvstgt_init);
module_exit(ibmvstgt_exit);