summaryrefslogtreecommitdiff
path: root/drivers/infiniband/hw/hfi1/pcie.c
blob: 0829fce06172fdbe99d0bdb0291531036367848a (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
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
/*
 * Copyright(c) 2015, 2016 Intel Corporation.
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * 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.
 *
 * BSD LICENSE
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  - Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  - Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  - Neither the name of Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <linux/pci.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/vmalloc.h>
#include <linux/aer.h>
#include <linux/module.h>

#include "hfi.h"
#include "chip_registers.h"
#include "aspm.h"

/* link speed vector for Gen3 speed - not in Linux headers */
#define GEN1_SPEED_VECTOR 0x1
#define GEN2_SPEED_VECTOR 0x2
#define GEN3_SPEED_VECTOR 0x3

/*
 * This file contains PCIe utility routines.
 */

/*
 * Code to adjust PCIe capabilities.
 */
static void tune_pcie_caps(struct hfi1_devdata *);

/*
 * Do all the common PCIe setup and initialization.
 * devdata is not yet allocated, and is not allocated until after this
 * routine returns success.  Therefore dd_dev_err() can't be used for error
 * printing.
 */
int hfi1_pcie_init(struct pci_dev *pdev, const struct pci_device_id *ent)
{
	int ret;

	ret = pci_enable_device(pdev);
	if (ret) {
		/*
		 * This can happen (in theory) iff:
		 * We did a chip reset, and then failed to reprogram the
		 * BAR, or the chip reset due to an internal error.  We then
		 * unloaded the driver and reloaded it.
		 *
		 * Both reset cases set the BAR back to initial state.  For
		 * the latter case, the AER sticky error bit at offset 0x718
		 * should be set, but the Linux kernel doesn't yet know
		 * about that, it appears.  If the original BAR was retained
		 * in the kernel data structures, this may be OK.
		 */
		hfi1_early_err(&pdev->dev, "pci enable failed: error %d\n",
			       -ret);
		goto done;
	}

	ret = pci_request_regions(pdev, DRIVER_NAME);
	if (ret) {
		hfi1_early_err(&pdev->dev,
			       "pci_request_regions fails: err %d\n", -ret);
		goto bail;
	}

	ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
	if (ret) {
		/*
		 * If the 64 bit setup fails, try 32 bit.  Some systems
		 * do not setup 64 bit maps on systems with 2GB or less
		 * memory installed.
		 */
		ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
		if (ret) {
			hfi1_early_err(&pdev->dev,
				       "Unable to set DMA mask: %d\n", ret);
			goto bail;
		}
		ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
	} else {
		ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
	}
	if (ret) {
		hfi1_early_err(&pdev->dev,
			       "Unable to set DMA consistent mask: %d\n", ret);
		goto bail;
	}

	pci_set_master(pdev);
	(void)pci_enable_pcie_error_reporting(pdev);
	goto done;

bail:
	hfi1_pcie_cleanup(pdev);
done:
	return ret;
}

/*
 * Clean what was done in hfi1_pcie_init()
 */
void hfi1_pcie_cleanup(struct pci_dev *pdev)
{
	pci_disable_device(pdev);
	/*
	 * Release regions should be called after the disable. OK to
	 * call if request regions has not been called or failed.
	 */
	pci_release_regions(pdev);
}

/*
 * Do remaining PCIe setup, once dd is allocated, and save away
 * fields required to re-initialize after a chip reset, or for
 * various other purposes
 */
int hfi1_pcie_ddinit(struct hfi1_devdata *dd, struct pci_dev *pdev)
{
	unsigned long len;
	resource_size_t addr;

	dd->pcidev = pdev;
	pci_set_drvdata(pdev, dd);

	addr = pci_resource_start(pdev, 0);
	len = pci_resource_len(pdev, 0);

	/*
	 * The TXE PIO buffers are at the tail end of the chip space.
	 * Cut them off and map them separately.
	 */

	/* sanity check vs expectations */
	if (len != TXE_PIO_SEND + TXE_PIO_SIZE) {
		dd_dev_err(dd, "chip PIO range does not match\n");
		return -EINVAL;
	}

	dd->kregbase = ioremap_nocache(addr, TXE_PIO_SEND);
	if (!dd->kregbase)
		return -ENOMEM;

	dd->piobase = ioremap_wc(addr + TXE_PIO_SEND, TXE_PIO_SIZE);
	if (!dd->piobase) {
		iounmap(dd->kregbase);
		return -ENOMEM;
	}

	dd->flags |= HFI1_PRESENT;	/* now register routines work */

	dd->kregend = dd->kregbase + TXE_PIO_SEND;
	dd->physaddr = addr;        /* used for io_remap, etc. */

	/*
	 * Re-map the chip's RcvArray as write-combining to allow us
	 * to write an entire cacheline worth of entries in one shot.
	 * If this re-map fails, just continue - the RcvArray programming
	 * function will handle both cases.
	 */
	dd->chip_rcv_array_count = read_csr(dd, RCV_ARRAY_CNT);
	dd->rcvarray_wc = ioremap_wc(addr + RCV_ARRAY,
				     dd->chip_rcv_array_count * 8);
	dd_dev_info(dd, "WC Remapped RcvArray: %p\n", dd->rcvarray_wc);
	/*
	 * Save BARs and command to rewrite after device reset.
	 */
	dd->pcibar0 = addr;
	dd->pcibar1 = addr >> 32;
	pci_read_config_dword(dd->pcidev, PCI_ROM_ADDRESS, &dd->pci_rom);
	pci_read_config_word(dd->pcidev, PCI_COMMAND, &dd->pci_command);
	pcie_capability_read_word(dd->pcidev, PCI_EXP_DEVCTL, &dd->pcie_devctl);
	pcie_capability_read_word(dd->pcidev, PCI_EXP_LNKCTL, &dd->pcie_lnkctl);
	pcie_capability_read_word(dd->pcidev, PCI_EXP_DEVCTL2,
				  &dd->pcie_devctl2);
	pci_read_config_dword(dd->pcidev, PCI_CFG_MSIX0, &dd->pci_msix0);
	pci_read_config_dword(dd->pcidev, PCIE_CFG_SPCIE1, &dd->pci_lnkctl3);
	pci_read_config_dword(dd->pcidev, PCIE_CFG_TPH2, &dd->pci_tph2);

	return 0;
}

/*
 * Do PCIe cleanup related to dd, after chip-specific cleanup, etc.  Just prior
 * to releasing the dd memory.
 * Void because all of the core pcie cleanup functions are void.
 */
void hfi1_pcie_ddcleanup(struct hfi1_devdata *dd)
{
	u64 __iomem *base = (void __iomem *)dd->kregbase;

	dd->flags &= ~HFI1_PRESENT;
	dd->kregbase = NULL;
	iounmap(base);
	if (dd->rcvarray_wc)
		iounmap(dd->rcvarray_wc);
	if (dd->piobase)
		iounmap(dd->piobase);
}

/*
 * Do a Function Level Reset (FLR) on the device.
 * Based on static function drivers/pci/pci.c:pcie_flr().
 */
void hfi1_pcie_flr(struct hfi1_devdata *dd)
{
	int i;
	u16 status;

	/* no need to check for the capability - we know the device has it */

	/* wait for Transaction Pending bit to clear, at most a few ms */
	for (i = 0; i < 4; i++) {
		if (i)
			msleep((1 << (i - 1)) * 100);

		pcie_capability_read_word(dd->pcidev, PCI_EXP_DEVSTA, &status);
		if (!(status & PCI_EXP_DEVSTA_TRPND))
			goto clear;
	}

	dd_dev_err(dd, "Transaction Pending bit is not clearing, proceeding with reset anyway\n");

clear:
	pcie_capability_set_word(dd->pcidev, PCI_EXP_DEVCTL,
				 PCI_EXP_DEVCTL_BCR_FLR);
	/* PCIe spec requires the function to be back within 100ms */
	msleep(100);
}

static void msix_setup(struct hfi1_devdata *dd, int pos, u32 *msixcnt,
		       struct hfi1_msix_entry *hfi1_msix_entry)
{
	int ret;
	int nvec = *msixcnt;
	struct msix_entry *msix_entry;
	int i;

	/*
	 * We can't pass hfi1_msix_entry array to msix_setup
	 * so use a dummy msix_entry array and copy the allocated
	 * irq back to the hfi1_msix_entry array.
	 */
	msix_entry = kmalloc_array(nvec, sizeof(*msix_entry), GFP_KERNEL);
	if (!msix_entry) {
		ret = -ENOMEM;
		goto do_intx;
	}

	for (i = 0; i < nvec; i++)
		msix_entry[i] = hfi1_msix_entry[i].msix;

	ret = pci_enable_msix_range(dd->pcidev, msix_entry, 1, nvec);
	if (ret < 0)
		goto free_msix_entry;
	nvec = ret;

	for (i = 0; i < nvec; i++)
		hfi1_msix_entry[i].msix = msix_entry[i];

	kfree(msix_entry);
	*msixcnt = nvec;
	return;

free_msix_entry:
	kfree(msix_entry);

do_intx:
	dd_dev_err(dd, "pci_enable_msix_range %d vectors failed: %d, falling back to INTx\n",
		   nvec, ret);
	*msixcnt = 0;
	hfi1_enable_intx(dd->pcidev);
}

/* return the PCIe link speed from the given link status */
static u32 extract_speed(u16 linkstat)
{
	u32 speed;

	switch (linkstat & PCI_EXP_LNKSTA_CLS) {
	default: /* not defined, assume Gen1 */
	case PCI_EXP_LNKSTA_CLS_2_5GB:
		speed = 2500; /* Gen 1, 2.5GHz */
		break;
	case PCI_EXP_LNKSTA_CLS_5_0GB:
		speed = 5000; /* Gen 2, 5GHz */
		break;
	case GEN3_SPEED_VECTOR:
		speed = 8000; /* Gen 3, 8GHz */
		break;
	}
	return speed;
}

/* return the PCIe link speed from the given link status */
static u32 extract_width(u16 linkstat)
{
	return (linkstat & PCI_EXP_LNKSTA_NLW) >> PCI_EXP_LNKSTA_NLW_SHIFT;
}

/* read the link status and set dd->{lbus_width,lbus_speed,lbus_info} */
static void update_lbus_info(struct hfi1_devdata *dd)
{
	u16 linkstat;

	pcie_capability_read_word(dd->pcidev, PCI_EXP_LNKSTA, &linkstat);
	dd->lbus_width = extract_width(linkstat);
	dd->lbus_speed = extract_speed(linkstat);
	snprintf(dd->lbus_info, sizeof(dd->lbus_info),
		 "PCIe,%uMHz,x%u", dd->lbus_speed, dd->lbus_width);
}

/*
 * Read in the current PCIe link width and speed.  Find if the link is
 * Gen3 capable.
 */
int pcie_speeds(struct hfi1_devdata *dd)
{
	u32 linkcap;
	struct pci_dev *parent = dd->pcidev->bus->self;

	if (!pci_is_pcie(dd->pcidev)) {
		dd_dev_err(dd, "Can't find PCI Express capability!\n");
		return -EINVAL;
	}

	/* find if our max speed is Gen3 and parent supports Gen3 speeds */
	dd->link_gen3_capable = 1;

	pcie_capability_read_dword(dd->pcidev, PCI_EXP_LNKCAP, &linkcap);
	if ((linkcap & PCI_EXP_LNKCAP_SLS) != GEN3_SPEED_VECTOR) {
		dd_dev_info(dd,
			    "This HFI is not Gen3 capable, max speed 0x%x, need 0x3\n",
			    linkcap & PCI_EXP_LNKCAP_SLS);
		dd->link_gen3_capable = 0;
	}

	/*
	 * bus->max_bus_speed is set from the bridge's linkcap Max Link Speed
	 */
	if (parent && dd->pcidev->bus->max_bus_speed != PCIE_SPEED_8_0GT) {
		dd_dev_info(dd, "Parent PCIe bridge does not support Gen3\n");
		dd->link_gen3_capable = 0;
	}

	/* obtain the link width and current speed */
	update_lbus_info(dd);

	dd_dev_info(dd, "%s\n", dd->lbus_info);

	return 0;
}

/*
 * Returns in *nent:
 *	- actual number of interrupts allocated
 *	- 0 if fell back to INTx.
 */
void request_msix(struct hfi1_devdata *dd, u32 *nent,
		  struct hfi1_msix_entry *entry)
{
	int pos;

	pos = dd->pcidev->msix_cap;
	if (*nent && pos) {
		msix_setup(dd, pos, nent, entry);
		/* did it, either MSI-X or INTx */
	} else {
		*nent = 0;
		hfi1_enable_intx(dd->pcidev);
	}

	tune_pcie_caps(dd);
}

void hfi1_enable_intx(struct pci_dev *pdev)
{
	/* first, turn on INTx */
	pci_intx(pdev, 1);
	/* then turn off MSI-X */
	pci_disable_msix(pdev);
}

/* restore command and BARs after a reset has wiped them out */
void restore_pci_variables(struct hfi1_devdata *dd)
{
	pci_write_config_word(dd->pcidev, PCI_COMMAND, dd->pci_command);
	pci_write_config_dword(dd->pcidev, PCI_BASE_ADDRESS_0, dd->pcibar0);
	pci_write_config_dword(dd->pcidev, PCI_BASE_ADDRESS_1, dd->pcibar1);
	pci_write_config_dword(dd->pcidev, PCI_ROM_ADDRESS, dd->pci_rom);
	pcie_capability_write_word(dd->pcidev, PCI_EXP_DEVCTL, dd->pcie_devctl);
	pcie_capability_write_word(dd->pcidev, PCI_EXP_LNKCTL, dd->pcie_lnkctl);
	pcie_capability_write_word(dd->pcidev, PCI_EXP_DEVCTL2,
				   dd->pcie_devctl2);
	pci_write_config_dword(dd->pcidev, PCI_CFG_MSIX0, dd->pci_msix0);
	pci_write_config_dword(dd->pcidev, PCIE_CFG_SPCIE1, dd->pci_lnkctl3);
	pci_write_config_dword(dd->pcidev, PCIE_CFG_TPH2, dd->pci_tph2);
}

/*
 * BIOS may not set PCIe bus-utilization parameters for best performance.
 * Check and optionally adjust them to maximize our throughput.
 */
static int hfi1_pcie_caps;
module_param_named(pcie_caps, hfi1_pcie_caps, int, S_IRUGO);
MODULE_PARM_DESC(pcie_caps, "Max PCIe tuning: Payload (0..3), ReadReq (4..7)");

uint aspm_mode = ASPM_MODE_DISABLED;
module_param_named(aspm, aspm_mode, uint, S_IRUGO);
MODULE_PARM_DESC(aspm, "PCIe ASPM: 0: disable, 1: enable, 2: dynamic");

static void tune_pcie_caps(struct hfi1_devdata *dd)
{
	struct pci_dev *parent;
	u16 rc_mpss, rc_mps, ep_mpss, ep_mps;
	u16 rc_mrrs, ep_mrrs, max_mrrs, ectl;

	/*
	 * Turn on extended tags in DevCtl in case the BIOS has turned it off
	 * to improve WFR SDMA bandwidth
	 */
	pcie_capability_read_word(dd->pcidev, PCI_EXP_DEVCTL, &ectl);
	if (!(ectl & PCI_EXP_DEVCTL_EXT_TAG)) {
		dd_dev_info(dd, "Enabling PCIe extended tags\n");
		ectl |= PCI_EXP_DEVCTL_EXT_TAG;
		pcie_capability_write_word(dd->pcidev, PCI_EXP_DEVCTL, ectl);
	}
	/* Find out supported and configured values for parent (root) */
	parent = dd->pcidev->bus->self;
	/*
	 * The driver cannot perform the tuning if it does not have
	 * access to the upstream component.
	 */
	if (!parent)
		return;
	if (!pci_is_root_bus(parent->bus)) {
		dd_dev_info(dd, "Parent not root\n");
		return;
	}

	if (!pci_is_pcie(parent) || !pci_is_pcie(dd->pcidev))
		return;
	rc_mpss = parent->pcie_mpss;
	rc_mps = ffs(pcie_get_mps(parent)) - 8;
	/* Find out supported and configured values for endpoint (us) */
	ep_mpss = dd->pcidev->pcie_mpss;
	ep_mps = ffs(pcie_get_mps(dd->pcidev)) - 8;

	/* Find max payload supported by root, endpoint */
	if (rc_mpss > ep_mpss)
		rc_mpss = ep_mpss;

	/* If Supported greater than limit in module param, limit it */
	if (rc_mpss > (hfi1_pcie_caps & 7))
		rc_mpss = hfi1_pcie_caps & 7;
	/* If less than (allowed, supported), bump root payload */
	if (rc_mpss > rc_mps) {
		rc_mps = rc_mpss;
		pcie_set_mps(parent, 128 << rc_mps);
	}
	/* If less than (allowed, supported), bump endpoint payload */
	if (rc_mpss > ep_mps) {
		ep_mps = rc_mpss;
		pcie_set_mps(dd->pcidev, 128 << ep_mps);
	}

	/*
	 * Now the Read Request size.
	 * No field for max supported, but PCIe spec limits it to 4096,
	 * which is code '5' (log2(4096) - 7)
	 */
	max_mrrs = 5;
	if (max_mrrs > ((hfi1_pcie_caps >> 4) & 7))
		max_mrrs = (hfi1_pcie_caps >> 4) & 7;

	max_mrrs = 128 << max_mrrs;
	rc_mrrs = pcie_get_readrq(parent);
	ep_mrrs = pcie_get_readrq(dd->pcidev);

	if (max_mrrs > rc_mrrs) {
		rc_mrrs = max_mrrs;
		pcie_set_readrq(parent, rc_mrrs);
	}
	if (max_mrrs > ep_mrrs) {
		ep_mrrs = max_mrrs;
		pcie_set_readrq(dd->pcidev, ep_mrrs);
	}
}

/* End of PCIe capability tuning */

/*
 * From here through hfi1_pci_err_handler definition is invoked via
 * PCI error infrastructure, registered via pci
 */
static pci_ers_result_t
pci_error_detected(struct pci_dev *pdev, pci_channel_state_t state)
{
	struct hfi1_devdata *dd = pci_get_drvdata(pdev);
	pci_ers_result_t ret = PCI_ERS_RESULT_RECOVERED;

	switch (state) {
	case pci_channel_io_normal:
		dd_dev_info(dd, "State Normal, ignoring\n");
		break;

	case pci_channel_io_frozen:
		dd_dev_info(dd, "State Frozen, requesting reset\n");
		pci_disable_device(pdev);
		ret = PCI_ERS_RESULT_NEED_RESET;
		break;

	case pci_channel_io_perm_failure:
		if (dd) {
			dd_dev_info(dd, "State Permanent Failure, disabling\n");
			/* no more register accesses! */
			dd->flags &= ~HFI1_PRESENT;
			hfi1_disable_after_error(dd);
		}
		 /* else early, or other problem */
		ret =  PCI_ERS_RESULT_DISCONNECT;
		break;

	default: /* shouldn't happen */
		dd_dev_info(dd, "HFI1 PCI errors detected (state %d)\n",
			    state);
		break;
	}
	return ret;
}

static pci_ers_result_t
pci_mmio_enabled(struct pci_dev *pdev)
{
	u64 words = 0U;
	struct hfi1_devdata *dd = pci_get_drvdata(pdev);
	pci_ers_result_t ret = PCI_ERS_RESULT_RECOVERED;

	if (dd && dd->pport) {
		words = read_port_cntr(dd->pport, C_RX_WORDS, CNTR_INVALID_VL);
		if (words == ~0ULL)
			ret = PCI_ERS_RESULT_NEED_RESET;
		dd_dev_info(dd,
			    "HFI1 mmio_enabled function called, read wordscntr %Lx, returning %d\n",
			    words, ret);
	}
	return  ret;
}

static pci_ers_result_t
pci_slot_reset(struct pci_dev *pdev)
{
	struct hfi1_devdata *dd = pci_get_drvdata(pdev);

	dd_dev_info(dd, "HFI1 slot_reset function called, ignored\n");
	return PCI_ERS_RESULT_CAN_RECOVER;
}

static void
pci_resume(struct pci_dev *pdev)
{
	struct hfi1_devdata *dd = pci_get_drvdata(pdev);

	dd_dev_info(dd, "HFI1 resume function called\n");
	pci_cleanup_aer_uncorrect_error_status(pdev);
	/*
	 * Running jobs will fail, since it's asynchronous
	 * unlike sysfs-requested reset.   Better than
	 * doing nothing.
	 */
	hfi1_init(dd, 1); /* same as re-init after reset */
}

const struct pci_error_handlers hfi1_pci_err_handler = {
	.error_detected = pci_error_detected,
	.mmio_enabled = pci_mmio_enabled,
	.slot_reset = pci_slot_reset,
	.resume = pci_resume,
};

/*============================================================================*/
/* PCIe Gen3 support */

/*
 * This code is separated out because it is expected to be removed in the
 * final shipping product.  If not, then it will be revisited and items
 * will be moved to more standard locations.
 */

/* ASIC_PCI_SD_HOST_STATUS.FW_DNLD_STS field values */
#define DL_STATUS_HFI0 0x1	/* hfi0 firmware download complete */
#define DL_STATUS_HFI1 0x2	/* hfi1 firmware download complete */
#define DL_STATUS_BOTH 0x3	/* hfi0 and hfi1 firmware download complete */

/* ASIC_PCI_SD_HOST_STATUS.FW_DNLD_ERR field values */
#define DL_ERR_NONE		0x0	/* no error */
#define DL_ERR_SWAP_PARITY	0x1	/* parity error in SerDes interrupt */
					/*   or response data */
#define DL_ERR_DISABLED	0x2	/* hfi disabled */
#define DL_ERR_SECURITY	0x3	/* security check failed */
#define DL_ERR_SBUS		0x4	/* SBus status error */
#define DL_ERR_XFR_PARITY	0x5	/* parity error during ROM transfer*/

/* gasket block secondary bus reset delay */
#define SBR_DELAY_US 200000	/* 200ms */

/* mask for PCIe capability register lnkctl2 target link speed */
#define LNKCTL2_TARGET_LINK_SPEED_MASK 0xf

static uint pcie_target = 3;
module_param(pcie_target, uint, S_IRUGO);
MODULE_PARM_DESC(pcie_target, "PCIe target speed (0 skip, 1-3 Gen1-3)");

static uint pcie_force;
module_param(pcie_force, uint, S_IRUGO);
MODULE_PARM_DESC(pcie_force, "Force driver to do a PCIe firmware download even if already at target speed");

static uint pcie_retry = 5;
module_param(pcie_retry, uint, S_IRUGO);
MODULE_PARM_DESC(pcie_retry, "Driver will try this many times to reach requested speed");

#define UNSET_PSET 255
#define DEFAULT_DISCRETE_PSET 2	/* discrete HFI */
#define DEFAULT_MCP_PSET 6	/* MCP HFI */
static uint pcie_pset = UNSET_PSET;
module_param(pcie_pset, uint, S_IRUGO);
MODULE_PARM_DESC(pcie_pset, "PCIe Eq Pset value to use, range is 0-10");

static uint pcie_ctle = 3; /* discrete on, integrated on */
module_param(pcie_ctle, uint, S_IRUGO);
MODULE_PARM_DESC(pcie_ctle, "PCIe static CTLE mode, bit 0 - discrete on/off, bit 1 - integrated on/off");

/* equalization columns */
#define PREC 0
#define ATTN 1
#define POST 2

/* discrete silicon preliminary equalization values */
static const u8 discrete_preliminary_eq[11][3] = {
	/* prec   attn   post */
	{  0x00,  0x00,  0x12 },	/* p0 */
	{  0x00,  0x00,  0x0c },	/* p1 */
	{  0x00,  0x00,  0x0f },	/* p2 */
	{  0x00,  0x00,  0x09 },	/* p3 */
	{  0x00,  0x00,  0x00 },	/* p4 */
	{  0x06,  0x00,  0x00 },	/* p5 */
	{  0x09,  0x00,  0x00 },	/* p6 */
	{  0x06,  0x00,  0x0f },	/* p7 */
	{  0x09,  0x00,  0x09 },	/* p8 */
	{  0x0c,  0x00,  0x00 },	/* p9 */
	{  0x00,  0x00,  0x18 },	/* p10 */
};

/* integrated silicon preliminary equalization values */
static const u8 integrated_preliminary_eq[11][3] = {
	/* prec   attn   post */
	{  0x00,  0x1e,  0x07 },	/* p0 */
	{  0x00,  0x1e,  0x05 },	/* p1 */
	{  0x00,  0x1e,  0x06 },	/* p2 */
	{  0x00,  0x1e,  0x04 },	/* p3 */
	{  0x00,  0x1e,  0x00 },	/* p4 */
	{  0x03,  0x1e,  0x00 },	/* p5 */
	{  0x04,  0x1e,  0x00 },	/* p6 */
	{  0x03,  0x1e,  0x06 },	/* p7 */
	{  0x03,  0x1e,  0x04 },	/* p8 */
	{  0x05,  0x1e,  0x00 },	/* p9 */
	{  0x00,  0x1e,  0x0a },	/* p10 */
};

static const u8 discrete_ctle_tunings[11][4] = {
	/* DC     LF     HF     BW */
	{  0x48,  0x0b,  0x04,  0x04 },	/* p0 */
	{  0x60,  0x05,  0x0f,  0x0a },	/* p1 */
	{  0x50,  0x09,  0x06,  0x06 },	/* p2 */
	{  0x68,  0x05,  0x0f,  0x0a },	/* p3 */
	{  0x80,  0x05,  0x0f,  0x0a },	/* p4 */
	{  0x70,  0x05,  0x0f,  0x0a },	/* p5 */
	{  0x68,  0x05,  0x0f,  0x0a },	/* p6 */
	{  0x38,  0x0f,  0x00,  0x00 },	/* p7 */
	{  0x48,  0x09,  0x06,  0x06 },	/* p8 */
	{  0x60,  0x05,  0x0f,  0x0a },	/* p9 */
	{  0x38,  0x0f,  0x00,  0x00 },	/* p10 */
};

static const u8 integrated_ctle_tunings[11][4] = {
	/* DC     LF     HF     BW */
	{  0x38,  0x0f,  0x00,  0x00 },	/* p0 */
	{  0x38,  0x0f,  0x00,  0x00 },	/* p1 */
	{  0x38,  0x0f,  0x00,  0x00 },	/* p2 */
	{  0x38,  0x0f,  0x00,  0x00 },	/* p3 */
	{  0x58,  0x0a,  0x05,  0x05 },	/* p4 */
	{  0x48,  0x0a,  0x05,  0x05 },	/* p5 */
	{  0x40,  0x0a,  0x05,  0x05 },	/* p6 */
	{  0x38,  0x0f,  0x00,  0x00 },	/* p7 */
	{  0x38,  0x0f,  0x00,  0x00 },	/* p8 */
	{  0x38,  0x09,  0x06,  0x06 },	/* p9 */
	{  0x38,  0x0e,  0x01,  0x01 },	/* p10 */
};

/* helper to format the value to write to hardware */
#define eq_value(pre, curr, post) \
	((((u32)(pre)) << \
			PCIE_CFG_REG_PL102_GEN3_EQ_PRE_CURSOR_PSET_SHIFT) \
	| (((u32)(curr)) << PCIE_CFG_REG_PL102_GEN3_EQ_CURSOR_PSET_SHIFT) \
	| (((u32)(post)) << \
		PCIE_CFG_REG_PL102_GEN3_EQ_POST_CURSOR_PSET_SHIFT))

/*
 * Load the given EQ preset table into the PCIe hardware.
 */
static int load_eq_table(struct hfi1_devdata *dd, const u8 eq[11][3], u8 fs,
			 u8 div)
{
	struct pci_dev *pdev = dd->pcidev;
	u32 hit_error = 0;
	u32 violation;
	u32 i;
	u8 c_minus1, c0, c_plus1;

	for (i = 0; i < 11; i++) {
		/* set index */
		pci_write_config_dword(pdev, PCIE_CFG_REG_PL103, i);
		/* write the value */
		c_minus1 = eq[i][PREC] / div;
		c0 = fs - (eq[i][PREC] / div) - (eq[i][POST] / div);
		c_plus1 = eq[i][POST] / div;
		pci_write_config_dword(pdev, PCIE_CFG_REG_PL102,
				       eq_value(c_minus1, c0, c_plus1));
		/* check if these coefficients violate EQ rules */
		pci_read_config_dword(dd->pcidev, PCIE_CFG_REG_PL105,
				      &violation);
		if (violation
		    & PCIE_CFG_REG_PL105_GEN3_EQ_VIOLATE_COEF_RULES_SMASK){
			if (hit_error == 0) {
				dd_dev_err(dd,
					   "Gen3 EQ Table Coefficient rule violations\n");
				dd_dev_err(dd, "         prec   attn   post\n");
			}
			dd_dev_err(dd, "   p%02d:   %02x     %02x     %02x\n",
				   i, (u32)eq[i][0], (u32)eq[i][1],
				   (u32)eq[i][2]);
			dd_dev_err(dd, "            %02x     %02x     %02x\n",
				   (u32)c_minus1, (u32)c0, (u32)c_plus1);
			hit_error = 1;
		}
	}
	if (hit_error)
		return -EINVAL;
	return 0;
}

/*
 * Steps to be done after the PCIe firmware is downloaded and
 * before the SBR for the Pcie Gen3.
 * The SBus resource is already being held.
 */
static void pcie_post_steps(struct hfi1_devdata *dd)
{
	int i;

	set_sbus_fast_mode(dd);
	/*
	 * Write to the PCIe PCSes to set the G3_LOCKED_NEXT bits to 1.
	 * This avoids a spurious framing error that can otherwise be
	 * generated by the MAC layer.
	 *
	 * Use individual addresses since no broadcast is set up.
	 */
	for (i = 0; i < NUM_PCIE_SERDES; i++) {
		sbus_request(dd, pcie_pcs_addrs[dd->hfi1_id][i],
			     0x03, WRITE_SBUS_RECEIVER, 0x00022132);
	}

	clear_sbus_fast_mode(dd);
}

/*
 * Trigger a secondary bus reset (SBR) on ourselves using our parent.
 *
 * Based on pci_parent_bus_reset() which is not exported by the
 * kernel core.
 */
static int trigger_sbr(struct hfi1_devdata *dd)
{
	struct pci_dev *dev = dd->pcidev;
	struct pci_dev *pdev;

	/* need a parent */
	if (!dev->bus->self) {
		dd_dev_err(dd, "%s: no parent device\n", __func__);
		return -ENOTTY;
	}

	/* should not be anyone else on the bus */
	list_for_each_entry(pdev, &dev->bus->devices, bus_list)
		if (pdev != dev) {
			dd_dev_err(dd,
				   "%s: another device is on the same bus\n",
				   __func__);
			return -ENOTTY;
		}

	/*
	 * A secondary bus reset (SBR) issues a hot reset to our device.
	 * The following routine does a 1s wait after the reset is dropped
	 * per PCI Trhfa (recovery time).  PCIe 3.0 section 6.6.1 -
	 * Conventional Reset, paragraph 3, line 35 also says that a 1s
	 * delay after a reset is required.  Per spec requirements,
	 * the link is either working or not after that point.
	 */
	pci_reset_bridge_secondary_bus(dev->bus->self);

	return 0;
}

/*
 * Write the given gasket interrupt register.
 */
static void write_gasket_interrupt(struct hfi1_devdata *dd, int index,
				   u16 code, u16 data)
{
	write_csr(dd, ASIC_PCIE_SD_INTRPT_LIST + (index * 8),
		  (((u64)code << ASIC_PCIE_SD_INTRPT_LIST_INTRPT_CODE_SHIFT) |
		   ((u64)data << ASIC_PCIE_SD_INTRPT_LIST_INTRPT_DATA_SHIFT)));
}

/*
 * Tell the gasket logic how to react to the reset.
 */
static void arm_gasket_logic(struct hfi1_devdata *dd)
{
	u64 reg;

	reg = (((u64)1 << dd->hfi1_id) <<
	       ASIC_PCIE_SD_HOST_CMD_INTRPT_CMD_SHIFT) |
	      ((u64)pcie_serdes_broadcast[dd->hfi1_id] <<
	       ASIC_PCIE_SD_HOST_CMD_SBUS_RCVR_ADDR_SHIFT |
	       ASIC_PCIE_SD_HOST_CMD_SBR_MODE_SMASK |
	       ((u64)SBR_DELAY_US & ASIC_PCIE_SD_HOST_CMD_TIMER_MASK) <<
	       ASIC_PCIE_SD_HOST_CMD_TIMER_SHIFT);
	write_csr(dd, ASIC_PCIE_SD_HOST_CMD, reg);
	/* read back to push the write */
	read_csr(dd, ASIC_PCIE_SD_HOST_CMD);
}

/*
 * CCE_PCIE_CTRL long name helpers
 * We redefine these shorter macros to use in the code while leaving
 * chip_registers.h to be autogenerated from the hardware spec.
 */
#define LANE_BUNDLE_MASK              CCE_PCIE_CTRL_PCIE_LANE_BUNDLE_MASK
#define LANE_BUNDLE_SHIFT             CCE_PCIE_CTRL_PCIE_LANE_BUNDLE_SHIFT
#define LANE_DELAY_MASK               CCE_PCIE_CTRL_PCIE_LANE_DELAY_MASK
#define LANE_DELAY_SHIFT              CCE_PCIE_CTRL_PCIE_LANE_DELAY_SHIFT
#define MARGIN_OVERWRITE_ENABLE_SHIFT CCE_PCIE_CTRL_XMT_MARGIN_OVERWRITE_ENABLE_SHIFT
#define MARGIN_SHIFT                  CCE_PCIE_CTRL_XMT_MARGIN_SHIFT
#define MARGIN_G1_G2_OVERWRITE_MASK   CCE_PCIE_CTRL_XMT_MARGIN_GEN1_GEN2_OVERWRITE_ENABLE_MASK
#define MARGIN_G1_G2_OVERWRITE_SHIFT  CCE_PCIE_CTRL_XMT_MARGIN_GEN1_GEN2_OVERWRITE_ENABLE_SHIFT
#define MARGIN_GEN1_GEN2_MASK         CCE_PCIE_CTRL_XMT_MARGIN_GEN1_GEN2_MASK
#define MARGIN_GEN1_GEN2_SHIFT        CCE_PCIE_CTRL_XMT_MARGIN_GEN1_GEN2_SHIFT

 /*
  * Write xmt_margin for full-swing (WFR-B) or half-swing (WFR-C).
  */
static void write_xmt_margin(struct hfi1_devdata *dd, const char *fname)
{
	u64 pcie_ctrl;
	u64 xmt_margin;
	u64 xmt_margin_oe;
	u64 lane_delay;
	u64 lane_bundle;

	pcie_ctrl = read_csr(dd, CCE_PCIE_CTRL);

	/*
	 * For Discrete, use full-swing.
	 *  - PCIe TX defaults to full-swing.
	 *    Leave this register as default.
	 * For Integrated, use half-swing
	 *  - Copy xmt_margin and xmt_margin_oe
	 *    from Gen1/Gen2 to Gen3.
	 */
	if (dd->pcidev->device == PCI_DEVICE_ID_INTEL1) { /* integrated */
		/* extract initial fields */
		xmt_margin = (pcie_ctrl >> MARGIN_GEN1_GEN2_SHIFT)
			      & MARGIN_GEN1_GEN2_MASK;
		xmt_margin_oe = (pcie_ctrl >> MARGIN_G1_G2_OVERWRITE_SHIFT)
				 & MARGIN_G1_G2_OVERWRITE_MASK;
		lane_delay = (pcie_ctrl >> LANE_DELAY_SHIFT) & LANE_DELAY_MASK;
		lane_bundle = (pcie_ctrl >> LANE_BUNDLE_SHIFT)
			       & LANE_BUNDLE_MASK;

		/*
		 * For A0, EFUSE values are not set.  Override with the
		 * correct values.
		 */
		if (is_ax(dd)) {
			/*
			 * xmt_margin and OverwiteEnabel should be the
			 * same for Gen1/Gen2 and Gen3
			 */
			xmt_margin = 0x5;
			xmt_margin_oe = 0x1;
			lane_delay = 0xF; /* Delay 240ns. */
			lane_bundle = 0x0; /* Set to 1 lane. */
		}

		/* overwrite existing values */
		pcie_ctrl = (xmt_margin << MARGIN_GEN1_GEN2_SHIFT)
			| (xmt_margin_oe << MARGIN_G1_G2_OVERWRITE_SHIFT)
			| (xmt_margin << MARGIN_SHIFT)
			| (xmt_margin_oe << MARGIN_OVERWRITE_ENABLE_SHIFT)
			| (lane_delay << LANE_DELAY_SHIFT)
			| (lane_bundle << LANE_BUNDLE_SHIFT);

		write_csr(dd, CCE_PCIE_CTRL, pcie_ctrl);
	}

	dd_dev_dbg(dd, "%s: program XMT margin, CcePcieCtrl 0x%llx\n",
		   fname, pcie_ctrl);
}

/*
 * Do all the steps needed to transition the PCIe link to Gen3 speed.
 */
int do_pcie_gen3_transition(struct hfi1_devdata *dd)
{
	struct pci_dev *parent = dd->pcidev->bus->self;
	u64 fw_ctrl;
	u64 reg, therm;
	u32 reg32, fs, lf;
	u32 status, err;
	int ret;
	int do_retry, retry_count = 0;
	int intnum = 0;
	uint default_pset;
	u16 target_vector, target_speed;
	u16 lnkctl2, vendor;
	u8 div;
	const u8 (*eq)[3];
	const u8 (*ctle_tunings)[4];
	uint static_ctle_mode;
	int return_error = 0;

	/* PCIe Gen3 is for the ASIC only */
	if (dd->icode != ICODE_RTL_SILICON)
		return 0;

	if (pcie_target == 1) {			/* target Gen1 */
		target_vector = GEN1_SPEED_VECTOR;
		target_speed = 2500;
	} else if (pcie_target == 2) {		/* target Gen2 */
		target_vector = GEN2_SPEED_VECTOR;
		target_speed = 5000;
	} else if (pcie_target == 3) {		/* target Gen3 */
		target_vector = GEN3_SPEED_VECTOR;
		target_speed = 8000;
	} else {
		/* off or invalid target - skip */
		dd_dev_info(dd, "%s: Skipping PCIe transition\n", __func__);
		return 0;
	}

	/* if already at target speed, done (unless forced) */
	if (dd->lbus_speed == target_speed) {
		dd_dev_info(dd, "%s: PCIe already at gen%d, %s\n", __func__,
			    pcie_target,
			    pcie_force ? "re-doing anyway" : "skipping");
		if (!pcie_force)
			return 0;
	}

	/*
	 * The driver cannot do the transition if it has no access to the
	 * upstream component
	 */
	if (!parent) {
		dd_dev_info(dd, "%s: No upstream, Can't do gen3 transition\n",
			    __func__);
		return 0;
	}

	/*
	 * Do the Gen3 transition.  Steps are those of the PCIe Gen3
	 * recipe.
	 */

	/* step 1: pcie link working in gen1/gen2 */

	/* step 2: if either side is not capable of Gen3, done */
	if (pcie_target == 3 && !dd->link_gen3_capable) {
		dd_dev_err(dd, "The PCIe link is not Gen3 capable\n");
		ret = -ENOSYS;
		goto done_no_mutex;
	}

	/* hold the SBus resource across the firmware download and SBR */
	ret = acquire_chip_resource(dd, CR_SBUS, SBUS_TIMEOUT);
	if (ret) {
		dd_dev_err(dd, "%s: unable to acquire SBus resource\n",
			   __func__);
		return ret;
	}

	/* make sure thermal polling is not causing interrupts */
	therm = read_csr(dd, ASIC_CFG_THERM_POLL_EN);
	if (therm) {
		write_csr(dd, ASIC_CFG_THERM_POLL_EN, 0x0);
		msleep(100);
		dd_dev_info(dd, "%s: Disabled therm polling\n",
			    __func__);
	}

retry:
	/* the SBus download will reset the spico for thermal */

	/* step 3: download SBus Master firmware */
	/* step 4: download PCIe Gen3 SerDes firmware */
	dd_dev_info(dd, "%s: downloading firmware\n", __func__);
	ret = load_pcie_firmware(dd);
	if (ret) {
		/* do not proceed if the firmware cannot be downloaded */
		return_error = 1;
		goto done;
	}

	/* step 5: set up device parameter settings */
	dd_dev_info(dd, "%s: setting PCIe registers\n", __func__);

	/*
	 * PcieCfgSpcie1 - Link Control 3
	 * Leave at reset value.  No need to set PerfEq - link equalization
	 * will be performed automatically after the SBR when the target
	 * speed is 8GT/s.
	 */

	/* clear all 16 per-lane error bits (PCIe: Lane Error Status) */
	pci_write_config_dword(dd->pcidev, PCIE_CFG_SPCIE2, 0xffff);

	/* step 5a: Set Synopsys Port Logic registers */

	/*
	 * PcieCfgRegPl2 - Port Force Link
	 *
	 * Set the low power field to 0x10 to avoid unnecessary power
	 * management messages.  All other fields are zero.
	 */
	reg32 = 0x10ul << PCIE_CFG_REG_PL2_LOW_PWR_ENT_CNT_SHIFT;
	pci_write_config_dword(dd->pcidev, PCIE_CFG_REG_PL2, reg32);

	/*
	 * PcieCfgRegPl100 - Gen3 Control
	 *
	 * turn off PcieCfgRegPl100.Gen3ZRxDcNonCompl
	 * turn on PcieCfgRegPl100.EqEieosCnt
	 * Everything else zero.
	 */
	reg32 = PCIE_CFG_REG_PL100_EQ_EIEOS_CNT_SMASK;
	pci_write_config_dword(dd->pcidev, PCIE_CFG_REG_PL100, reg32);

	/*
	 * PcieCfgRegPl101 - Gen3 EQ FS and LF
	 * PcieCfgRegPl102 - Gen3 EQ Presets to Coefficients Mapping
	 * PcieCfgRegPl103 - Gen3 EQ Preset Index
	 * PcieCfgRegPl105 - Gen3 EQ Status
	 *
	 * Give initial EQ settings.
	 */
	if (dd->pcidev->device == PCI_DEVICE_ID_INTEL0) { /* discrete */
		/* 1000mV, FS=24, LF = 8 */
		fs = 24;
		lf = 8;
		div = 3;
		eq = discrete_preliminary_eq;
		default_pset = DEFAULT_DISCRETE_PSET;
		ctle_tunings = discrete_ctle_tunings;
		/* bit 0 - discrete on/off */
		static_ctle_mode = pcie_ctle & 0x1;
	} else {
		/* 400mV, FS=29, LF = 9 */
		fs = 29;
		lf = 9;
		div = 1;
		eq = integrated_preliminary_eq;
		default_pset = DEFAULT_MCP_PSET;
		ctle_tunings = integrated_ctle_tunings;
		/* bit 1 - integrated on/off */
		static_ctle_mode = (pcie_ctle >> 1) & 0x1;
	}
	pci_write_config_dword(dd->pcidev, PCIE_CFG_REG_PL101,
			       (fs <<
				PCIE_CFG_REG_PL101_GEN3_EQ_LOCAL_FS_SHIFT) |
			       (lf <<
				PCIE_CFG_REG_PL101_GEN3_EQ_LOCAL_LF_SHIFT));
	ret = load_eq_table(dd, eq, fs, div);
	if (ret)
		goto done;

	/*
	 * PcieCfgRegPl106 - Gen3 EQ Control
	 *
	 * Set Gen3EqPsetReqVec, leave other fields 0.
	 */
	if (pcie_pset == UNSET_PSET)
		pcie_pset = default_pset;
	if (pcie_pset > 10) {	/* valid range is 0-10, inclusive */
		dd_dev_err(dd, "%s: Invalid Eq Pset %u, setting to %d\n",
			   __func__, pcie_pset, default_pset);
		pcie_pset = default_pset;
	}
	dd_dev_info(dd, "%s: using EQ Pset %u\n", __func__, pcie_pset);
	pci_write_config_dword(dd->pcidev, PCIE_CFG_REG_PL106,
			       ((1 << pcie_pset) <<
			PCIE_CFG_REG_PL106_GEN3_EQ_PSET_REQ_VEC_SHIFT) |
			PCIE_CFG_REG_PL106_GEN3_EQ_EVAL2MS_DISABLE_SMASK |
			PCIE_CFG_REG_PL106_GEN3_EQ_PHASE23_EXIT_MODE_SMASK);

	/*
	 * step 5b: Do post firmware download steps via SBus
	 */
	dd_dev_info(dd, "%s: doing pcie post steps\n", __func__);
	pcie_post_steps(dd);

	/*
	 * step 5c: Program gasket interrupts
	 */
	/* set the Rx Bit Rate to REFCLK ratio */
	write_gasket_interrupt(dd, intnum++, 0x0006, 0x0050);
	/* disable pCal for PCIe Gen3 RX equalization */
	/* select adaptive or static CTLE */
	write_gasket_interrupt(dd, intnum++, 0x0026,
			       0x5b01 | (static_ctle_mode << 3));
	/*
	 * Enable iCal for PCIe Gen3 RX equalization, and set which
	 * evaluation of RX_EQ_EVAL will launch the iCal procedure.
	 */
	write_gasket_interrupt(dd, intnum++, 0x0026, 0x5202);

	if (static_ctle_mode) {
		/* apply static CTLE tunings */
		u8 pcie_dc, pcie_lf, pcie_hf, pcie_bw;

		pcie_dc = ctle_tunings[pcie_pset][0];
		pcie_lf = ctle_tunings[pcie_pset][1];
		pcie_hf = ctle_tunings[pcie_pset][2];
		pcie_bw = ctle_tunings[pcie_pset][3];
		write_gasket_interrupt(dd, intnum++, 0x0026, 0x0200 | pcie_dc);
		write_gasket_interrupt(dd, intnum++, 0x0026, 0x0100 | pcie_lf);
		write_gasket_interrupt(dd, intnum++, 0x0026, 0x0000 | pcie_hf);
		write_gasket_interrupt(dd, intnum++, 0x0026, 0x5500 | pcie_bw);
	}

	/* terminate list */
	write_gasket_interrupt(dd, intnum++, 0x0000, 0x0000);

	/*
	 * step 5d: program XMT margin
	 */
	write_xmt_margin(dd, __func__);

	/*
	 * step 5e: disable active state power management (ASPM). It
	 * will be enabled if required later
	 */
	dd_dev_info(dd, "%s: clearing ASPM\n", __func__);
	aspm_hw_disable_l1(dd);

	/*
	 * step 5f: clear DirectSpeedChange
	 * PcieCfgRegPl67.DirectSpeedChange must be zero to prevent the
	 * change in the speed target from starting before we are ready.
	 * This field defaults to 0 and we are not changing it, so nothing
	 * needs to be done.
	 */

	/* step 5g: Set target link speed */
	/*
	 * Set target link speed to be target on both device and parent.
	 * On setting the parent: Some system BIOSs "helpfully" set the
	 * parent target speed to Gen2 to match the ASIC's initial speed.
	 * We can set the target Gen3 because we have already checked
	 * that it is Gen3 capable earlier.
	 */
	dd_dev_info(dd, "%s: setting parent target link speed\n", __func__);
	pcie_capability_read_word(parent, PCI_EXP_LNKCTL2, &lnkctl2);
	dd_dev_info(dd, "%s: ..old link control2: 0x%x\n", __func__,
		    (u32)lnkctl2);
	/* only write to parent if target is not as high as ours */
	if ((lnkctl2 & LNKCTL2_TARGET_LINK_SPEED_MASK) < target_vector) {
		lnkctl2 &= ~LNKCTL2_TARGET_LINK_SPEED_MASK;
		lnkctl2 |= target_vector;
		dd_dev_info(dd, "%s: ..new link control2: 0x%x\n", __func__,
			    (u32)lnkctl2);
		pcie_capability_write_word(parent, PCI_EXP_LNKCTL2, lnkctl2);
	} else {
		dd_dev_info(dd, "%s: ..target speed is OK\n", __func__);
	}

	dd_dev_info(dd, "%s: setting target link speed\n", __func__);
	pcie_capability_read_word(dd->pcidev, PCI_EXP_LNKCTL2, &lnkctl2);
	dd_dev_info(dd, "%s: ..old link control2: 0x%x\n", __func__,
		    (u32)lnkctl2);
	lnkctl2 &= ~LNKCTL2_TARGET_LINK_SPEED_MASK;
	lnkctl2 |= target_vector;
	dd_dev_info(dd, "%s: ..new link control2: 0x%x\n", __func__,
		    (u32)lnkctl2);
	pcie_capability_write_word(dd->pcidev, PCI_EXP_LNKCTL2, lnkctl2);

	/* step 5h: arm gasket logic */
	/* hold DC in reset across the SBR */
	write_csr(dd, CCE_DC_CTRL, CCE_DC_CTRL_DC_RESET_SMASK);
	(void)read_csr(dd, CCE_DC_CTRL); /* DC reset hold */
	/* save firmware control across the SBR */
	fw_ctrl = read_csr(dd, MISC_CFG_FW_CTRL);

	dd_dev_info(dd, "%s: arming gasket logic\n", __func__);
	arm_gasket_logic(dd);

	/*
	 * step 6: quiesce PCIe link
	 * The chip has already been reset, so there will be no traffic
	 * from the chip.  Linux has no easy way to enforce that it will
	 * not try to access the device, so we just need to hope it doesn't
	 * do it while we are doing the reset.
	 */

	/*
	 * step 7: initiate the secondary bus reset (SBR)
	 * step 8: hardware brings the links back up
	 * step 9: wait for link speed transition to be complete
	 */
	dd_dev_info(dd, "%s: calling trigger_sbr\n", __func__);
	ret = trigger_sbr(dd);
	if (ret)
		goto done;

	/* step 10: decide what to do next */

	/* check if we can read PCI space */
	ret = pci_read_config_word(dd->pcidev, PCI_VENDOR_ID, &vendor);
	if (ret) {
		dd_dev_info(dd,
			    "%s: read of VendorID failed after SBR, err %d\n",
			    __func__, ret);
		return_error = 1;
		goto done;
	}
	if (vendor == 0xffff) {
		dd_dev_info(dd, "%s: VendorID is all 1s after SBR\n", __func__);
		return_error = 1;
		ret = -EIO;
		goto done;
	}

	/* restore PCI space registers we know were reset */
	dd_dev_info(dd, "%s: calling restore_pci_variables\n", __func__);
	restore_pci_variables(dd);
	/* restore firmware control */
	write_csr(dd, MISC_CFG_FW_CTRL, fw_ctrl);

	/*
	 * Check the gasket block status.
	 *
	 * This is the first CSR read after the SBR.  If the read returns
	 * all 1s (fails), the link did not make it back.
	 *
	 * Once we're sure we can read and write, clear the DC reset after
	 * the SBR.  Then check for any per-lane errors. Then look over
	 * the status.
	 */
	reg = read_csr(dd, ASIC_PCIE_SD_HOST_STATUS);
	dd_dev_info(dd, "%s: gasket block status: 0x%llx\n", __func__, reg);
	if (reg == ~0ull) {	/* PCIe read failed/timeout */
		dd_dev_err(dd, "SBR failed - unable to read from device\n");
		return_error = 1;
		ret = -ENOSYS;
		goto done;
	}

	/* clear the DC reset */
	write_csr(dd, CCE_DC_CTRL, 0);

	/* Set the LED off */
	setextled(dd, 0);

	/* check for any per-lane errors */
	pci_read_config_dword(dd->pcidev, PCIE_CFG_SPCIE2, &reg32);
	dd_dev_info(dd, "%s: per-lane errors: 0x%x\n", __func__, reg32);

	/* extract status, look for our HFI */
	status = (reg >> ASIC_PCIE_SD_HOST_STATUS_FW_DNLD_STS_SHIFT)
			& ASIC_PCIE_SD_HOST_STATUS_FW_DNLD_STS_MASK;
	if ((status & (1 << dd->hfi1_id)) == 0) {
		dd_dev_err(dd,
			   "%s: gasket status 0x%x, expecting 0x%x\n",
			   __func__, status, 1 << dd->hfi1_id);
		ret = -EIO;
		goto done;
	}

	/* extract error */
	err = (reg >> ASIC_PCIE_SD_HOST_STATUS_FW_DNLD_ERR_SHIFT)
		& ASIC_PCIE_SD_HOST_STATUS_FW_DNLD_ERR_MASK;
	if (err) {
		dd_dev_err(dd, "%s: gasket error %d\n", __func__, err);
		ret = -EIO;
		goto done;
	}

	/* update our link information cache */
	update_lbus_info(dd);
	dd_dev_info(dd, "%s: new speed and width: %s\n", __func__,
		    dd->lbus_info);

	if (dd->lbus_speed != target_speed) { /* not target */
		/* maybe retry */
		do_retry = retry_count < pcie_retry;
		dd_dev_err(dd, "PCIe link speed did not switch to Gen%d%s\n",
			   pcie_target, do_retry ? ", retrying" : "");
		retry_count++;
		if (do_retry) {
			msleep(100); /* allow time to settle */
			goto retry;
		}
		ret = -EIO;
	}

done:
	if (therm) {
		write_csr(dd, ASIC_CFG_THERM_POLL_EN, 0x1);
		msleep(100);
		dd_dev_info(dd, "%s: Re-enable therm polling\n",
			    __func__);
	}
	release_chip_resource(dd, CR_SBUS);
done_no_mutex:
	/* return no error if it is OK to be at current speed */
	if (ret && !return_error) {
		dd_dev_err(dd, "Proceeding at current speed PCIe speed\n");
		ret = 0;
	}

	dd_dev_info(dd, "%s: done\n", __func__);
	return ret;
}