aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/scsi/qla2xxx/qla_iocb.c
blob: 6d2bd97c3b1133617ef22d494c16b537ab4bf44b (plain) (blame)
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
/*
 * QLogic Fibre Channel HBA Driver
 * Copyright (c)  2003-2008 QLogic Corporation
 *
 * See LICENSE.qla2xxx for copyright and licensing details.
 */
#include "qla_def.h"

#include <linux/blkdev.h>
#include <linux/delay.h>

#include <scsi/scsi_tcq.h>

static request_t *qla2x00_req_pkt(struct scsi_qla_host *, struct req_que *,
							struct rsp_que *rsp);
static void qla2x00_isp_cmd(struct scsi_qla_host *, struct req_que *);

/**
 * qla2x00_get_cmd_direction() - Determine control_flag data direction.
 * @cmd: SCSI command
 *
 * Returns the proper CF_* direction based on CDB.
 */
static inline uint16_t
qla2x00_get_cmd_direction(srb_t *sp)
{
	uint16_t cflags;

	cflags = 0;

	/* Set transfer direction */
	if (sp->cmd->sc_data_direction == DMA_TO_DEVICE) {
		cflags = CF_WRITE;
		sp->fcport->vha->hw->qla_stats.output_bytes +=
		    scsi_bufflen(sp->cmd);
	} else if (sp->cmd->sc_data_direction == DMA_FROM_DEVICE) {
		cflags = CF_READ;
		sp->fcport->vha->hw->qla_stats.input_bytes +=
		    scsi_bufflen(sp->cmd);
	}
	return (cflags);
}

/**
 * qla2x00_calc_iocbs_32() - Determine number of Command Type 2 and
 * Continuation Type 0 IOCBs to allocate.
 *
 * @dsds: number of data segment decriptors needed
 *
 * Returns the number of IOCB entries needed to store @dsds.
 */
uint16_t
qla2x00_calc_iocbs_32(uint16_t dsds)
{
	uint16_t iocbs;

	iocbs = 1;
	if (dsds > 3) {
		iocbs += (dsds - 3) / 7;
		if ((dsds - 3) % 7)
			iocbs++;
	}
	return (iocbs);
}

/**
 * qla2x00_calc_iocbs_64() - Determine number of Command Type 3 and
 * Continuation Type 1 IOCBs to allocate.
 *
 * @dsds: number of data segment decriptors needed
 *
 * Returns the number of IOCB entries needed to store @dsds.
 */
uint16_t
qla2x00_calc_iocbs_64(uint16_t dsds)
{
	uint16_t iocbs;

	iocbs = 1;
	if (dsds > 2) {
		iocbs += (dsds - 2) / 5;
		if ((dsds - 2) % 5)
			iocbs++;
	}
	return (iocbs);
}

/**
 * qla2x00_prep_cont_type0_iocb() - Initialize a Continuation Type 0 IOCB.
 * @ha: HA context
 *
 * Returns a pointer to the Continuation Type 0 IOCB packet.
 */
static inline cont_entry_t *
qla2x00_prep_cont_type0_iocb(struct req_que *req, struct scsi_qla_host *vha)
{
	cont_entry_t *cont_pkt;
	/* Adjust ring index. */
	req->ring_index++;
	if (req->ring_index == req->length) {
		req->ring_index = 0;
		req->ring_ptr = req->ring;
	} else {
		req->ring_ptr++;
	}

	cont_pkt = (cont_entry_t *)req->ring_ptr;

	/* Load packet defaults. */
	*((uint32_t *)(&cont_pkt->entry_type)) =
	    __constant_cpu_to_le32(CONTINUE_TYPE);

	return (cont_pkt);
}

/**
 * qla2x00_prep_cont_type1_iocb() - Initialize a Continuation Type 1 IOCB.
 * @ha: HA context
 *
 * Returns a pointer to the continuation type 1 IOCB packet.
 */
static inline cont_a64_entry_t *
qla2x00_prep_cont_type1_iocb(struct req_que *req, scsi_qla_host_t *vha)
{
	cont_a64_entry_t *cont_pkt;

	/* Adjust ring index. */
	req->ring_index++;
	if (req->ring_index == req->length) {
		req->ring_index = 0;
		req->ring_ptr = req->ring;
	} else {
		req->ring_ptr++;
	}

	cont_pkt = (cont_a64_entry_t *)req->ring_ptr;

	/* Load packet defaults. */
	*((uint32_t *)(&cont_pkt->entry_type)) =
	    __constant_cpu_to_le32(CONTINUE_A64_TYPE);

	return (cont_pkt);
}

/**
 * qla2x00_build_scsi_iocbs_32() - Build IOCB command utilizing 32bit
 * capable IOCB types.
 *
 * @sp: SRB command to process
 * @cmd_pkt: Command type 2 IOCB
 * @tot_dsds: Total number of segments to transfer
 */
void qla2x00_build_scsi_iocbs_32(srb_t *sp, cmd_entry_t *cmd_pkt,
    uint16_t tot_dsds)
{
	uint16_t	avail_dsds;
	uint32_t	*cur_dsd;
	scsi_qla_host_t	*vha;
	struct scsi_cmnd *cmd;
	struct scatterlist *sg;
	int i;
	struct req_que *req;
	uint16_t que_id;

	cmd = sp->cmd;

	/* Update entry type to indicate Command Type 2 IOCB */
	*((uint32_t *)(&cmd_pkt->entry_type)) =
	    __constant_cpu_to_le32(COMMAND_TYPE);

	/* No data transfer */
	if (!scsi_bufflen(cmd) || cmd->sc_data_direction == DMA_NONE) {
		cmd_pkt->byte_count = __constant_cpu_to_le32(0);
		return;
	}

	vha = sp->vha;
	que_id = vha->req_ques[0];
	req = vha->hw->req_q_map[que_id];

	cmd_pkt->control_flags |= cpu_to_le16(qla2x00_get_cmd_direction(sp));

	/* Three DSDs are available in the Command Type 2 IOCB */
	avail_dsds = 3;
	cur_dsd = (uint32_t *)&cmd_pkt->dseg_0_address;

	/* Load data segments */
	scsi_for_each_sg(cmd, sg, tot_dsds, i) {
		cont_entry_t *cont_pkt;

		/* Allocate additional continuation packets? */
		if (avail_dsds == 0) {
			/*
			 * Seven DSDs are available in the Continuation
			 * Type 0 IOCB.
			 */
			cont_pkt = qla2x00_prep_cont_type0_iocb(req, vha);
			cur_dsd = (uint32_t *)&cont_pkt->dseg_0_address;
			avail_dsds = 7;
		}

		*cur_dsd++ = cpu_to_le32(sg_dma_address(sg));
		*cur_dsd++ = cpu_to_le32(sg_dma_len(sg));
		avail_dsds--;
	}
}

/**
 * qla2x00_build_scsi_iocbs_64() - Build IOCB command utilizing 64bit
 * capable IOCB types.
 *
 * @sp: SRB command to process
 * @cmd_pkt: Command type 3 IOCB
 * @tot_dsds: Total number of segments to transfer
 */
void qla2x00_build_scsi_iocbs_64(srb_t *sp, cmd_entry_t *cmd_pkt,
    uint16_t tot_dsds)
{
	uint16_t	avail_dsds;
	uint32_t	*cur_dsd;
	scsi_qla_host_t	*vha;
	struct scsi_cmnd *cmd;
	struct scatterlist *sg;
	int i;
	struct req_que *req;
	uint16_t que_id;

	cmd = sp->cmd;

	/* Update entry type to indicate Command Type 3 IOCB */
	*((uint32_t *)(&cmd_pkt->entry_type)) =
	    __constant_cpu_to_le32(COMMAND_A64_TYPE);

	/* No data transfer */
	if (!scsi_bufflen(cmd) || cmd->sc_data_direction == DMA_NONE) {
		cmd_pkt->byte_count = __constant_cpu_to_le32(0);
		return;
	}

	vha = sp->vha;
	que_id = vha->req_ques[0];
	req = vha->hw->req_q_map[que_id];

	cmd_pkt->control_flags |= cpu_to_le16(qla2x00_get_cmd_direction(sp));

	/* Two DSDs are available in the Command Type 3 IOCB */
	avail_dsds = 2;
	cur_dsd = (uint32_t *)&cmd_pkt->dseg_0_address;

	/* Load data segments */
	scsi_for_each_sg(cmd, sg, tot_dsds, i) {
		dma_addr_t	sle_dma;
		cont_a64_entry_t *cont_pkt;

		/* Allocate additional continuation packets? */
		if (avail_dsds == 0) {
			/*
			 * Five DSDs are available in the Continuation
			 * Type 1 IOCB.
			 */
			cont_pkt = qla2x00_prep_cont_type1_iocb(req, vha);
			cur_dsd = (uint32_t *)cont_pkt->dseg_0_address;
			avail_dsds = 5;
		}

		sle_dma = sg_dma_address(sg);
		*cur_dsd++ = cpu_to_le32(LSD(sle_dma));
		*cur_dsd++ = cpu_to_le32(MSD(sle_dma));
		*cur_dsd++ = cpu_to_le32(sg_dma_len(sg));
		avail_dsds--;
	}
}

/**
 * qla2x00_start_scsi() - Send a SCSI command to the ISP
 * @sp: command to send to the ISP
 *
 * Returns non-zero if a failure occurred, else zero.
 */
int
qla2x00_start_scsi(srb_t *sp)
{
	int		ret, nseg;
	unsigned long   flags;
	scsi_qla_host_t	*vha;
	struct scsi_cmnd *cmd;
	uint32_t	*clr_ptr;
	uint32_t        index;
	uint32_t	handle;
	cmd_entry_t	*cmd_pkt;
	uint16_t	cnt;
	uint16_t	req_cnt;
	uint16_t	tot_dsds;
	struct device_reg_2xxx __iomem *reg;
	struct qla_hw_data *ha;
	struct req_que *req;
	struct rsp_que *rsp;

	/* Setup device pointers. */
	ret = 0;
	vha = sp->vha;
	ha = vha->hw;
	reg = &ha->iobase->isp;
	cmd = sp->cmd;
	req = ha->req_q_map[0];
	rsp = ha->rsp_q_map[0];
	/* So we know we haven't pci_map'ed anything yet */
	tot_dsds = 0;

	/* Send marker if required */
	if (vha->marker_needed != 0) {
		if (qla2x00_marker(vha, req, rsp, 0, 0, MK_SYNC_ALL)
							!= QLA_SUCCESS)
			return (QLA_FUNCTION_FAILED);
		vha->marker_needed = 0;
	}

	/* Acquire ring specific lock */
	spin_lock_irqsave(&ha->hardware_lock, flags);

	/* Check for room in outstanding command list. */
	handle = req->current_outstanding_cmd;
	for (index = 1; index < MAX_OUTSTANDING_COMMANDS; index++) {
		handle++;
		if (handle == MAX_OUTSTANDING_COMMANDS)
			handle = 1;
		if (!req->outstanding_cmds[handle])
			break;
	}
	if (index == MAX_OUTSTANDING_COMMANDS)
		goto queuing_error;

	/* Map the sg table so we have an accurate count of sg entries needed */
	if (scsi_sg_count(cmd)) {
		nseg = dma_map_sg(&ha->pdev->dev, scsi_sglist(cmd),
		    scsi_sg_count(cmd), cmd->sc_data_direction);
		if (unlikely(!nseg))
			goto queuing_error;
	} else
		nseg = 0;

	tot_dsds = nseg;

	/* Calculate the number of request entries needed. */
	req_cnt = ha->isp_ops->calc_req_entries(tot_dsds);
	if (req->cnt < (req_cnt + 2)) {
		cnt = RD_REG_WORD_RELAXED(ISP_REQ_Q_OUT(ha, reg));
		if (req->ring_index < cnt)
			req->cnt = cnt - req->ring_index;
		else
			req->cnt = req->length -
			    (req->ring_index - cnt);
	}
	if (req->cnt < (req_cnt + 2))
		goto queuing_error;

	/* Build command packet */
	req->current_outstanding_cmd = handle;
	req->outstanding_cmds[handle] = sp;
	sp->vha = vha;
	sp->cmd->host_scribble = (unsigned char *)(unsigned long)handle;
	req->cnt -= req_cnt;

	cmd_pkt = (cmd_entry_t *)req->ring_ptr;
	cmd_pkt->handle = handle;
	/* Zero out remaining portion of packet. */
	clr_ptr = (uint32_t *)cmd_pkt + 2;
	memset(clr_ptr, 0, REQUEST_ENTRY_SIZE - 8);
	cmd_pkt->dseg_count = cpu_to_le16(tot_dsds);

	/* Set target ID and LUN number*/
	SET_TARGET_ID(ha, cmd_pkt->target, sp->fcport->loop_id);
	cmd_pkt->lun = cpu_to_le16(sp->cmd->device->lun);

	/* Update tagged queuing modifier */
	cmd_pkt->control_flags = __constant_cpu_to_le16(CF_SIMPLE_TAG);

	/* Load SCSI command packet. */
	memcpy(cmd_pkt->scsi_cdb, cmd->cmnd, cmd->cmd_len);
	cmd_pkt->byte_count = cpu_to_le32((uint32_t)scsi_bufflen(cmd));

	/* Build IOCB segments */
	ha->isp_ops->build_iocbs(sp, cmd_pkt, tot_dsds);

	/* Set total data segment count. */
	cmd_pkt->entry_count = (uint8_t)req_cnt;
	wmb();

	/* Adjust ring index. */
	req->ring_index++;
	if (req->ring_index == req->length) {
		req->ring_index = 0;
		req->ring_ptr = req->ring;
	} else
		req->ring_ptr++;

	sp->flags |= SRB_DMA_VALID;

	/* Set chip new ring index. */
	WRT_REG_WORD(ISP_REQ_Q_IN(ha, reg), req->ring_index);
	RD_REG_WORD_RELAXED(ISP_REQ_Q_IN(ha, reg));	/* PCI Posting. */

	/* Manage unprocessed RIO/ZIO commands in response queue. */
	if (vha->flags.process_response_queue &&
	    rsp->ring_ptr->signature != RESPONSE_PROCESSED)
		qla2x00_process_response_queue(rsp);

	spin_unlock_irqrestore(&ha->hardware_lock, flags);
	return (QLA_SUCCESS);

queuing_error:
	if (tot_dsds)
		scsi_dma_unmap(cmd);

	spin_unlock_irqrestore(&ha->hardware_lock, flags);

	return (QLA_FUNCTION_FAILED);
}

/**
 * qla2x00_marker() - Send a marker IOCB to the firmware.
 * @ha: HA context
 * @loop_id: loop ID
 * @lun: LUN
 * @type: marker modifier
 *
 * Can be called from both normal and interrupt context.
 *
 * Returns non-zero if a failure occurred, else zero.
 */
int
__qla2x00_marker(struct scsi_qla_host *vha, struct req_que *req,
			struct rsp_que *rsp, uint16_t loop_id,
			uint16_t lun, uint8_t type)
{
	mrk_entry_t *mrk;
	struct mrk_entry_24xx *mrk24;
	struct qla_hw_data *ha = vha->hw;
	scsi_qla_host_t *base_vha = pci_get_drvdata(ha->pdev);

	mrk24 = NULL;
	mrk = (mrk_entry_t *)qla2x00_req_pkt(vha, req, rsp);
	if (mrk == NULL) {
		DEBUG2_3(printk("%s(%ld): failed to allocate Marker IOCB.\n",
		    __func__, base_vha->host_no));

		return (QLA_FUNCTION_FAILED);
	}

	mrk->entry_type = MARKER_TYPE;
	mrk->modifier = type;
	if (type != MK_SYNC_ALL) {
		if (IS_FWI2_CAPABLE(ha)) {
			mrk24 = (struct mrk_entry_24xx *) mrk;
			mrk24->nport_handle = cpu_to_le16(loop_id);
			mrk24->lun[1] = LSB(lun);
			mrk24->lun[2] = MSB(lun);
			host_to_fcp_swap(mrk24->lun, sizeof(mrk24->lun));
			mrk24->vp_index = vha->vp_idx;
		} else {
			SET_TARGET_ID(ha, mrk->target, loop_id);
			mrk->lun = cpu_to_le16(lun);
		}
	}
	wmb();

	qla2x00_isp_cmd(vha, req);

	return (QLA_SUCCESS);
}

int
qla2x00_marker(struct scsi_qla_host *vha, struct req_que *req,
		struct rsp_que *rsp, uint16_t loop_id, uint16_t lun,
		uint8_t type)
{
	int ret;
	unsigned long flags = 0;

	spin_lock_irqsave(&vha->hw->hardware_lock, flags);
	ret = __qla2x00_marker(vha, req, rsp, loop_id, lun, type);
	spin_unlock_irqrestore(&vha->hw->hardware_lock, flags);

	return (ret);
}

/**
 * qla2x00_req_pkt() - Retrieve a request packet from the request ring.
 * @ha: HA context
 *
 * Note: The caller must hold the hardware lock before calling this routine.
 *
 * Returns NULL if function failed, else, a pointer to the request packet.
 */
static request_t *
qla2x00_req_pkt(struct scsi_qla_host *vha, struct req_que *req,
		struct rsp_que *rsp)
{
	struct qla_hw_data *ha = vha->hw;
	device_reg_t __iomem *reg = ISP_QUE_REG(ha, req->id);
	request_t	*pkt = NULL;
	uint16_t	cnt;
	uint32_t	*dword_ptr;
	uint32_t	timer;
	uint16_t	req_cnt = 1;

	/* Wait 1 second for slot. */
	for (timer = HZ; timer; timer--) {
		if ((req_cnt + 2) >= req->cnt) {
			/* Calculate number of free request entries. */
			if (ha->mqenable)
				cnt = (uint16_t)
					RD_REG_DWORD(&reg->isp25mq.req_q_out);
			else {
				if (IS_FWI2_CAPABLE(ha))
					cnt = (uint16_t)RD_REG_DWORD(
						&reg->isp24.req_q_out);
				else
					cnt = qla2x00_debounce_register(
						ISP_REQ_Q_OUT(ha, &reg->isp));
			}
			if  (req->ring_index < cnt)
				req->cnt = cnt - req->ring_index;
			else
				req->cnt = req->length -
				    (req->ring_index - cnt);
		}
		/* If room for request in request ring. */
		if ((req_cnt + 2) < req->cnt) {
			req->cnt--;
			pkt = req->ring_ptr;

			/* Zero out packet. */
			dword_ptr = (uint32_t *)pkt;
			for (cnt = 0; cnt < REQUEST_ENTRY_SIZE / 4; cnt++)
				*dword_ptr++ = 0;

			/* Set system defined field. */
			pkt->sys_define = (uint8_t)req->ring_index;

			/* Set entry count. */
			pkt->entry_count = 1;

			break;
		}

		/* Release ring specific lock */
		spin_unlock_irq(&ha->hardware_lock);

		udelay(2);   /* 2 us */

		/* Check for pending interrupts. */
		/* During init we issue marker directly */
		if (!vha->marker_needed && !vha->flags.init_done)
			qla2x00_poll(rsp);
		spin_lock_irq(&ha->hardware_lock);
	}
	if (!pkt) {
		DEBUG2_3(printk("%s(): **** FAILED ****\n", __func__));
	}

	return (pkt);
}

/**
 * qla2x00_isp_cmd() - Modify the request ring pointer.
 * @ha: HA context
 *
 * Note: The caller must hold the hardware lock before calling this routine.
 */
static void
qla2x00_isp_cmd(struct scsi_qla_host *vha, struct req_que *req)
{
	struct qla_hw_data *ha = vha->hw;
	device_reg_t __iomem *reg = ISP_QUE_REG(ha, req->id);

	DEBUG5(printk("%s(): IOCB data:\n", __func__));
	DEBUG5(qla2x00_dump_buffer(
	    (uint8_t *)req->ring_ptr, REQUEST_ENTRY_SIZE));

	/* Adjust ring index. */
	req->ring_index++;
	if (req->ring_index == req->length) {
		req->ring_index = 0;
		req->ring_ptr = req->ring;
	} else
		req->ring_ptr++;

	/* Set chip new ring index. */
	if (ha->mqenable)
		RD_REG_DWORD(&reg->isp25mq.req_q_out);
	else {
		if (IS_FWI2_CAPABLE(ha)) {
			WRT_REG_DWORD(&reg->isp24.req_q_in, req->ring_index);
			RD_REG_DWORD_RELAXED(&reg->isp24.req_q_in);
		} else {
			WRT_REG_WORD(ISP_REQ_Q_IN(ha, &reg->isp),
				req->ring_index);
			RD_REG_WORD_RELAXED(ISP_REQ_Q_IN(ha, &reg->isp));
		}
	}

}

/**
 * qla24xx_calc_iocbs() - Determine number of Command Type 3 and
 * Continuation Type 1 IOCBs to allocate.
 *
 * @dsds: number of data segment decriptors needed
 *
 * Returns the number of IOCB entries needed to store @dsds.
 */
static inline uint16_t
qla24xx_calc_iocbs(uint16_t dsds)
{
	uint16_t iocbs;

	iocbs = 1;
	if (dsds > 1) {
		iocbs += (dsds - 1) / 5;
		if ((dsds - 1) % 5)
			iocbs++;
	}
	return iocbs;
}

/**
 * qla24xx_build_scsi_iocbs() - Build IOCB command utilizing Command Type 7
 * IOCB types.
 *
 * @sp: SRB command to process
 * @cmd_pkt: Command type 3 IOCB
 * @tot_dsds: Total number of segments to transfer
 */
static inline void
qla24xx_build_scsi_iocbs(srb_t *sp, struct cmd_type_7 *cmd_pkt,
    uint16_t tot_dsds)
{
	uint16_t	avail_dsds;
	uint32_t	*cur_dsd;
	scsi_qla_host_t	*vha;
	struct scsi_cmnd *cmd;
	struct scatterlist *sg;
	int i;
	uint16_t que_id;
	struct req_que *req;

	cmd = sp->cmd;

	/* Update entry type to indicate Command Type 3 IOCB */
	*((uint32_t *)(&cmd_pkt->entry_type)) =
	    __constant_cpu_to_le32(COMMAND_TYPE_7);

	/* No data transfer */
	if (!scsi_bufflen(cmd) || cmd->sc_data_direction == DMA_NONE) {
		cmd_pkt->byte_count = __constant_cpu_to_le32(0);
		return;
	}

	vha = sp->vha;
	que_id = vha->req_ques[0];
	req = vha->hw->req_q_map[que_id];

	/* Set transfer direction */
	if (cmd->sc_data_direction == DMA_TO_DEVICE) {
		cmd_pkt->task_mgmt_flags =
		    __constant_cpu_to_le16(TMF_WRITE_DATA);
		sp->fcport->vha->hw->qla_stats.output_bytes +=
		    scsi_bufflen(sp->cmd);
	} else if (cmd->sc_data_direction == DMA_FROM_DEVICE) {
		cmd_pkt->task_mgmt_flags =
		    __constant_cpu_to_le16(TMF_READ_DATA);
		sp->fcport->vha->hw->qla_stats.input_bytes +=
		    scsi_bufflen(sp->cmd);
	}

	/* One DSD is available in the Command Type 3 IOCB */
	avail_dsds = 1;
	cur_dsd = (uint32_t *)&cmd_pkt->dseg_0_address;

	/* Load data segments */

	scsi_for_each_sg(cmd, sg, tot_dsds, i) {
		dma_addr_t	sle_dma;
		cont_a64_entry_t *cont_pkt;

		/* Allocate additional continuation packets? */
		if (avail_dsds == 0) {
			/*
			 * Five DSDs are available in the Continuation
			 * Type 1 IOCB.
			 */
			cont_pkt = qla2x00_prep_cont_type1_iocb(req, vha);
			cur_dsd = (uint32_t *)cont_pkt->dseg_0_address;
			avail_dsds = 5;
		}

		sle_dma = sg_dma_address(sg);
		*cur_dsd++ = cpu_to_le32(LSD(sle_dma));
		*cur_dsd++ = cpu_to_le32(MSD(sle_dma));
		*cur_dsd++ = cpu_to_le32(sg_dma_len(sg));
		avail_dsds--;
	}
}


/**
 * qla24xx_start_scsi() - Send a SCSI command to the ISP
 * @sp: command to send to the ISP
 *
 * Returns non-zero if a failure occurred, else zero.
 */
int
qla24xx_start_scsi(srb_t *sp)
{
	int		ret, nseg;
	unsigned long   flags;
	uint32_t	*clr_ptr;
	uint32_t        index;
	uint32_t	handle;
	struct cmd_type_7 *cmd_pkt;
	uint16_t	cnt;
	uint16_t	req_cnt;
	uint16_t	tot_dsds;
	struct req_que *req = NULL;
	struct rsp_que *rsp = NULL;
	struct scsi_cmnd *cmd = sp->cmd;
	struct scsi_qla_host *vha = sp->vha;
	struct qla_hw_data *ha = vha->hw;
	device_reg_t __iomem *reg;
	uint16_t que_id;

	/* Setup device pointers. */
	ret = 0;
	que_id = vha->req_ques[0];

	req = ha->req_q_map[que_id];
	reg = ISP_QUE_REG(ha, req->id);

	if (req->rsp)
		rsp = req->rsp;
	else
		rsp = ha->rsp_q_map[que_id];
	/* So we know we haven't pci_map'ed anything yet */
	tot_dsds = 0;

	/* Send marker if required */
	if (vha->marker_needed != 0) {
		if (qla2x00_marker(vha, req, rsp, 0, 0, MK_SYNC_ALL)
							!= QLA_SUCCESS)
			return QLA_FUNCTION_FAILED;
		vha->marker_needed = 0;
	}

	/* Acquire ring specific lock */
	spin_lock_irqsave(&ha->hardware_lock, flags);

	/* Check for room in outstanding command list. */
	handle = req->current_outstanding_cmd;
	for (index = 1; index < MAX_OUTSTANDING_COMMANDS; index++) {
		handle++;
		if (handle == MAX_OUTSTANDING_COMMANDS)
			handle = 1;
		if (!req->outstanding_cmds[handle])
			break;
	}
	if (index == MAX_OUTSTANDING_COMMANDS)
		goto queuing_error;

	/* Map the sg table so we have an accurate count of sg entries needed */
	if (scsi_sg_count(cmd)) {
		nseg = dma_map_sg(&ha->pdev->dev, scsi_sglist(cmd),
		    scsi_sg_count(cmd), cmd->sc_data_direction);
		if (unlikely(!nseg))
			goto queuing_error;
	} else
		nseg = 0;

	tot_dsds = nseg;

	req_cnt = qla24xx_calc_iocbs(tot_dsds);
	if (req->cnt < (req_cnt + 2)) {
		if (ha->mqenable)
			cnt = (uint16_t)
				RD_REG_DWORD_RELAXED(&reg->isp25mq.req_q_out);
		else
			cnt = (uint16_t)
				RD_REG_DWORD_RELAXED(&reg->isp24.req_q_out);

		if (req->ring_index < cnt)
			req->cnt = cnt - req->ring_index;
		else
			req->cnt = req->length -
				(req->ring_index - cnt);
	}
	if (req->cnt < (req_cnt + 2))
		goto queuing_error;

	/* Build command packet. */
	req->current_outstanding_cmd = handle;
	req->outstanding_cmds[handle] = sp;
	sp->vha = vha;
	sp->cmd->host_scribble = (unsigned char *)(unsigned long)handle;
	req->cnt -= req_cnt;

	cmd_pkt = (struct cmd_type_7 *)req->ring_ptr;
	cmd_pkt->handle = handle;

	/* Zero out remaining portion of packet. */
	/*    tagged queuing modifier -- default is TSK_SIMPLE (0). */
	clr_ptr = (uint32_t *)cmd_pkt + 2;
	memset(clr_ptr, 0, REQUEST_ENTRY_SIZE - 8);
	cmd_pkt->dseg_count = cpu_to_le16(tot_dsds);

	/* Set NPORT-ID and LUN number*/
	cmd_pkt->nport_handle = cpu_to_le16(sp->fcport->loop_id);
	cmd_pkt->port_id[0] = sp->fcport->d_id.b.al_pa;
	cmd_pkt->port_id[1] = sp->fcport->d_id.b.area;
	cmd_pkt->port_id[2] = sp->fcport->d_id.b.domain;
	cmd_pkt->vp_index = sp->fcport->vp_idx;

	int_to_scsilun(sp->cmd->device->lun, &cmd_pkt->lun);
	host_to_fcp_swap((uint8_t *)&cmd_pkt->lun, sizeof(cmd_pkt->lun));

	/* Load SCSI command packet. */
	memcpy(cmd_pkt->fcp_cdb, cmd->cmnd, cmd->cmd_len);
	host_to_fcp_swap(cmd_pkt->fcp_cdb, sizeof(cmd_pkt->fcp_cdb));

	cmd_pkt->byte_count = cpu_to_le32((uint32_t)scsi_bufflen(cmd));

	/* Build IOCB segments */
	qla24xx_build_scsi_iocbs(sp, cmd_pkt, tot_dsds);

	/* Set total data segment count. */
	cmd_pkt->entry_count = (uint8_t)req_cnt;
	wmb();

	/* Adjust ring index. */
	req->ring_index++;
	if (req->ring_index == req->length) {
		req->ring_index = 0;
		req->ring_ptr = req->ring;
	} else
		req->ring_ptr++;

	sp->flags |= SRB_DMA_VALID;

	/* Set chip new ring index. */
	if (ha->mqenable)
		WRT_REG_DWORD(&reg->isp25mq.req_q_in, req->ring_index);
	else {
		WRT_REG_DWORD(&reg->isp24.req_q_in, req->ring_index);
		RD_REG_DWORD_RELAXED(&reg->isp24.req_q_in);
	}

	/* Manage unprocessed RIO/ZIO commands in response queue. */
	if (vha->flags.process_response_queue &&
		rsp->ring_ptr->signature != RESPONSE_PROCESSED)
		qla24xx_process_response_queue(rsp);

	spin_unlock_irqrestore(&ha->hardware_lock, flags);
	return QLA_SUCCESS;

queuing_error:
	if (tot_dsds)
		scsi_dma_unmap(cmd);

	spin_unlock_irqrestore(&ha->hardware_lock, flags);

	return QLA_FUNCTION_FAILED;
}