summaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/traps.c
blob: 261ccbc0774016aa6d055eb19dd82067f7ad65e8 (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
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1994 - 1999, 2000, 01, 06 Ralf Baechle
 * Copyright (C) 1995, 1996 Paul M. Antoine
 * Copyright (C) 1998 Ulf Carlsson
 * Copyright (C) 1999 Silicon Graphics, Inc.
 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
 * Copyright (C) 2000, 01 MIPS Technologies, Inc.
 * Copyright (C) 2002, 2003, 2004, 2005, 2007  Maciej W. Rozycki
 */
#include <linux/bug.h>
#include <linux/compiler.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/bootmem.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/kgdb.h>
#include <linux/kdebug.h>
#include <linux/kprobes.h>
#include <linux/notifier.h>
#include <linux/kdb.h>
#include <linux/irq.h>
#include <linux/perf_event.h>

#include <asm/bootinfo.h>
#include <asm/branch.h>
#include <asm/break.h>
#include <asm/cop2.h>
#include <asm/cpu.h>
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/fpu_emulator.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/module.h>
#include <asm/pgtable.h>
#include <asm/ptrace.h>
#include <asm/sections.h>
#include <asm/system.h>
#include <asm/tlbdebug.h>
#include <asm/traps.h>
#include <asm/uaccess.h>
#include <asm/watch.h>
#include <asm/mmu_context.h>
#include <asm/types.h>
#include <asm/stacktrace.h>
#include <asm/uasm.h>

extern void check_wait(void);
extern asmlinkage void r4k_wait(void);
extern asmlinkage void rollback_handle_int(void);
extern asmlinkage void handle_int(void);
extern asmlinkage void handle_tlbm(void);
extern asmlinkage void handle_tlbl(void);
extern asmlinkage void handle_tlbs(void);
extern asmlinkage void handle_adel(void);
extern asmlinkage void handle_ades(void);
extern asmlinkage void handle_ibe(void);
extern asmlinkage void handle_dbe(void);
extern asmlinkage void handle_sys(void);
extern asmlinkage void handle_bp(void);
extern asmlinkage void handle_ri(void);
extern asmlinkage void handle_ri_rdhwr_vivt(void);
extern asmlinkage void handle_ri_rdhwr(void);
extern asmlinkage void handle_cpu(void);
extern asmlinkage void handle_ov(void);
extern asmlinkage void handle_tr(void);
extern asmlinkage void handle_fpe(void);
extern asmlinkage void handle_mdmx(void);
extern asmlinkage void handle_watch(void);
extern asmlinkage void handle_mt(void);
extern asmlinkage void handle_dsp(void);
extern asmlinkage void handle_mcheck(void);
extern asmlinkage void handle_reserved(void);

extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
				    struct mips_fpu_struct *ctx, int has_fpu,
				    void *__user *fault_addr);

void (*board_be_init)(void);
int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
void (*board_nmi_handler_setup)(void);
void (*board_ejtag_handler_setup)(void);
void (*board_bind_eic_interrupt)(int irq, int regset);


static void show_raw_backtrace(unsigned long reg29)
{
	unsigned long *sp = (unsigned long *)(reg29 & ~3);
	unsigned long addr;

	printk("Call Trace:");
#ifdef CONFIG_KALLSYMS
	printk("\n");
#endif
	while (!kstack_end(sp)) {
		unsigned long __user *p =
			(unsigned long __user *)(unsigned long)sp++;
		if (__get_user(addr, p)) {
			printk(" (Bad stack address)");
			break;
		}
		if (__kernel_text_address(addr))
			print_ip_sym(addr);
	}
	printk("\n");
}

#ifdef CONFIG_KALLSYMS
int raw_show_trace;
static int __init set_raw_show_trace(char *str)
{
	raw_show_trace = 1;
	return 1;
}
__setup("raw_show_trace", set_raw_show_trace);
#endif

static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
{
	unsigned long sp = regs->regs[29];
	unsigned long ra = regs->regs[31];
	unsigned long pc = regs->cp0_epc;

	if (raw_show_trace || !__kernel_text_address(pc)) {
		show_raw_backtrace(sp);
		return;
	}
	printk("Call Trace:\n");
	do {
		print_ip_sym(pc);
		pc = unwind_stack(task, &sp, pc, &ra);
	} while (pc);
	printk("\n");
}

/*
 * This routine abuses get_user()/put_user() to reference pointers
 * with at least a bit of error checking ...
 */
static void show_stacktrace(struct task_struct *task,
	const struct pt_regs *regs)
{
	const int field = 2 * sizeof(unsigned long);
	long stackdata;
	int i;
	unsigned long __user *sp = (unsigned long __user *)regs->regs[29];

	printk("Stack :");
	i = 0;
	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
		if (i && ((i % (64 / field)) == 0))
			printk("\n       ");
		if (i > 39) {
			printk(" ...");
			break;
		}

		if (__get_user(stackdata, sp++)) {
			printk(" (Bad stack address)");
			break;
		}

		printk(" %0*lx", field, stackdata);
		i++;
	}
	printk("\n");
	show_backtrace(task, regs);
}

void show_stack(struct task_struct *task, unsigned long *sp)
{
	struct pt_regs regs;
	if (sp) {
		regs.regs[29] = (unsigned long)sp;
		regs.regs[31] = 0;
		regs.cp0_epc = 0;
	} else {
		if (task && task != current) {
			regs.regs[29] = task->thread.reg29;
			regs.regs[31] = 0;
			regs.cp0_epc = task->thread.reg31;
#ifdef CONFIG_KGDB_KDB
		} else if (atomic_read(&kgdb_active) != -1 &&
			   kdb_current_regs) {
			memcpy(&regs, kdb_current_regs, sizeof(regs));
#endif /* CONFIG_KGDB_KDB */
		} else {
			prepare_frametrace(&regs);
		}
	}
	show_stacktrace(task, &regs);
}

/*
 * The architecture-independent dump_stack generator
 */
void dump_stack(void)
{
	struct pt_regs regs;

	prepare_frametrace(&regs);
	show_backtrace(current, &regs);
}

EXPORT_SYMBOL(dump_stack);

static void show_code(unsigned int __user *pc)
{
	long i;
	unsigned short __user *pc16 = NULL;

	printk("\nCode:");

	if ((unsigned long)pc & 1)
		pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
	for(i = -3 ; i < 6 ; i++) {
		unsigned int insn;
		if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
			printk(" (Bad address in epc)\n");
			break;
		}
		printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
	}
}

static void __show_regs(const struct pt_regs *regs)
{
	const int field = 2 * sizeof(unsigned long);
	unsigned int cause = regs->cp0_cause;
	int i;

	printk("Cpu %d\n", smp_processor_id());

	/*
	 * Saved main processor registers
	 */
	for (i = 0; i < 32; ) {
		if ((i % 4) == 0)
			printk("$%2d   :", i);
		if (i == 0)
			printk(" %0*lx", field, 0UL);
		else if (i == 26 || i == 27)
			printk(" %*s", field, "");
		else
			printk(" %0*lx", field, regs->regs[i]);

		i++;
		if ((i % 4) == 0)
			printk("\n");
	}

#ifdef CONFIG_CPU_HAS_SMARTMIPS
	printk("Acx    : %0*lx\n", field, regs->acx);
#endif
	printk("Hi    : %0*lx\n", field, regs->hi);
	printk("Lo    : %0*lx\n", field, regs->lo);

	/*
	 * Saved cp0 registers
	 */
	printk("epc   : %0*lx %pS\n", field, regs->cp0_epc,
	       (void *) regs->cp0_epc);
	printk("    %s\n", print_tainted());
	printk("ra    : %0*lx %pS\n", field, regs->regs[31],
	       (void *) regs->regs[31]);

	printk("Status: %08x    ", (uint32_t) regs->cp0_status);

	if (current_cpu_data.isa_level == MIPS_CPU_ISA_I) {
		if (regs->cp0_status & ST0_KUO)
			printk("KUo ");
		if (regs->cp0_status & ST0_IEO)
			printk("IEo ");
		if (regs->cp0_status & ST0_KUP)
			printk("KUp ");
		if (regs->cp0_status & ST0_IEP)
			printk("IEp ");
		if (regs->cp0_status & ST0_KUC)
			printk("KUc ");
		if (regs->cp0_status & ST0_IEC)
			printk("IEc ");
	} else {
		if (regs->cp0_status & ST0_KX)
			printk("KX ");
		if (regs->cp0_status & ST0_SX)
			printk("SX ");
		if (regs->cp0_status & ST0_UX)
			printk("UX ");
		switch (regs->cp0_status & ST0_KSU) {
		case KSU_USER:
			printk("USER ");
			break;
		case KSU_SUPERVISOR:
			printk("SUPERVISOR ");
			break;
		case KSU_KERNEL:
			printk("KERNEL ");
			break;
		default:
			printk("BAD_MODE ");
			break;
		}
		if (regs->cp0_status & ST0_ERL)
			printk("ERL ");
		if (regs->cp0_status & ST0_EXL)
			printk("EXL ");
		if (regs->cp0_status & ST0_IE)
			printk("IE ");
	}
	printk("\n");

	printk("Cause : %08x\n", cause);

	cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
	if (1 <= cause && cause <= 5)
		printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);

	printk("PrId  : %08x (%s)\n", read_c0_prid(),
	       cpu_name_string());
}

/*
 * FIXME: really the generic show_regs should take a const pointer argument.
 */
void show_regs(struct pt_regs *regs)
{
	__show_regs((struct pt_regs *)regs);
}

void show_registers(struct pt_regs *regs)
{
	const int field = 2 * sizeof(unsigned long);

	__show_regs(regs);
	print_modules();
	printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
	       current->comm, current->pid, current_thread_info(), current,
	      field, current_thread_info()->tp_value);
	if (cpu_has_userlocal) {
		unsigned long tls;

		tls = read_c0_userlocal();
		if (tls != current_thread_info()->tp_value)
			printk("*HwTLS: %0*lx\n", field, tls);
	}

	show_stacktrace(current, regs);
	show_code((unsigned int __user *) regs->cp0_epc);
	printk("\n");
}

static int regs_to_trapnr(struct pt_regs *regs)
{
	return (regs->cp0_cause >> 2) & 0x1f;
}

static DEFINE_RAW_SPINLOCK(die_lock);

void __noreturn die(const char *str, struct pt_regs *regs)
{
	static int die_counter;
	int sig = SIGSEGV;
#ifdef CONFIG_MIPS_MT_SMTC
	unsigned long dvpret;
#endif /* CONFIG_MIPS_MT_SMTC */

	oops_enter();

	if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs), SIGSEGV) == NOTIFY_STOP)
		sig = 0;

	console_verbose();
	raw_spin_lock_irq(&die_lock);
#ifdef CONFIG_MIPS_MT_SMTC
	dvpret = dvpe();
#endif /* CONFIG_MIPS_MT_SMTC */
	bust_spinlocks(1);
#ifdef CONFIG_MIPS_MT_SMTC
	mips_mt_regdump(dvpret);
#endif /* CONFIG_MIPS_MT_SMTC */

	printk("%s[#%d]:\n", str, ++die_counter);
	show_registers(regs);
	add_taint(TAINT_DIE);
	raw_spin_unlock_irq(&die_lock);

	oops_exit();

	if (in_interrupt())
		panic("Fatal exception in interrupt");

	if (panic_on_oops) {
		printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
		ssleep(5);
		panic("Fatal exception");
	}

	do_exit(sig);
}

extern struct exception_table_entry __start___dbe_table[];
extern struct exception_table_entry __stop___dbe_table[];

__asm__(
"	.section	__dbe_table, \"a\"\n"
"	.previous			\n");

/* Given an address, look for it in the exception tables. */
static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
{
	const struct exception_table_entry *e;

	e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
	if (!e)
		e = search_module_dbetables(addr);
	return e;
}

asmlinkage void do_be(struct pt_regs *regs)
{
	const int field = 2 * sizeof(unsigned long);
	const struct exception_table_entry *fixup = NULL;
	int data = regs->cp0_cause & 4;
	int action = MIPS_BE_FATAL;

	/* XXX For now.  Fixme, this searches the wrong table ...  */
	if (data && !user_mode(regs))
		fixup = search_dbe_tables(exception_epc(regs));

	if (fixup)
		action = MIPS_BE_FIXUP;

	if (board_be_handler)
		action = board_be_handler(regs, fixup != NULL);

	switch (action) {
	case MIPS_BE_DISCARD:
		return;
	case MIPS_BE_FIXUP:
		if (fixup) {
			regs->cp0_epc = fixup->nextinsn;
			return;
		}
		break;
	default:
		break;
	}

	/*
	 * Assume it would be too dangerous to continue ...
	 */
	printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
	       data ? "Data" : "Instruction",
	       field, regs->cp0_epc, field, regs->regs[31]);
	if (notify_die(DIE_OOPS, "bus error", regs, 0, regs_to_trapnr(regs), SIGBUS)
	    == NOTIFY_STOP)
		return;

	die_if_kernel("Oops", regs);
	force_sig(SIGBUS, current);
}

/*
 * ll/sc, rdhwr, sync emulation
 */

#define OPCODE 0xfc000000
#define BASE   0x03e00000
#define RT     0x001f0000
#define OFFSET 0x0000ffff
#define LL     0xc0000000
#define SC     0xe0000000
#define SPEC0  0x00000000
#define SPEC3  0x7c000000
#define RD     0x0000f800
#define FUNC   0x0000003f
#define SYNC   0x0000000f
#define RDHWR  0x0000003b

/*
 * The ll_bit is cleared by r*_switch.S
 */

unsigned int ll_bit;
struct task_struct *ll_task;

static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
{
	unsigned long value, __user *vaddr;
	long offset;

	/*
	 * analyse the ll instruction that just caused a ri exception
	 * and put the referenced address to addr.
	 */

	/* sign extend offset */
	offset = opcode & OFFSET;
	offset <<= 16;
	offset >>= 16;

	vaddr = (unsigned long __user *)
	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);

	if ((unsigned long)vaddr & 3)
		return SIGBUS;
	if (get_user(value, vaddr))
		return SIGSEGV;

	preempt_disable();

	if (ll_task == NULL || ll_task == current) {
		ll_bit = 1;
	} else {
		ll_bit = 0;
	}
	ll_task = current;

	preempt_enable();

	regs->regs[(opcode & RT) >> 16] = value;

	return 0;
}

static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
{
	unsigned long __user *vaddr;
	unsigned long reg;
	long offset;

	/*
	 * analyse the sc instruction that just caused a ri exception
	 * and put the referenced address to addr.
	 */

	/* sign extend offset */
	offset = opcode & OFFSET;
	offset <<= 16;
	offset >>= 16;

	vaddr = (unsigned long __user *)
	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
	reg = (opcode & RT) >> 16;

	if ((unsigned long)vaddr & 3)
		return SIGBUS;

	preempt_disable();

	if (ll_bit == 0 || ll_task != current) {
		regs->regs[reg] = 0;
		preempt_enable();
		return 0;
	}

	preempt_enable();

	if (put_user(regs->regs[reg], vaddr))
		return SIGSEGV;

	regs->regs[reg] = 1;

	return 0;
}

/*
 * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
 * opcodes are supposed to result in coprocessor unusable exceptions if
 * executed on ll/sc-less processors.  That's the theory.  In practice a
 * few processors such as NEC's VR4100 throw reserved instruction exceptions
 * instead, so we're doing the emulation thing in both exception handlers.
 */
static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
{
	if ((opcode & OPCODE) == LL) {
		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
				1, regs, 0);
		return simulate_ll(regs, opcode);
	}
	if ((opcode & OPCODE) == SC) {
		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
				1, regs, 0);
		return simulate_sc(regs, opcode);
	}

	return -1;			/* Must be something else ... */
}

/*
 * Simulate trapping 'rdhwr' instructions to provide user accessible
 * registers not implemented in hardware.
 */
static int simulate_rdhwr(struct pt_regs *regs, unsigned int opcode)
{
	struct thread_info *ti = task_thread_info(current);

	if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
		int rd = (opcode & RD) >> 11;
		int rt = (opcode & RT) >> 16;
		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
				1, regs, 0);
		switch (rd) {
		case 0:		/* CPU number */
			regs->regs[rt] = smp_processor_id();
			return 0;
		case 1:		/* SYNCI length */
			regs->regs[rt] = min(current_cpu_data.dcache.linesz,
					     current_cpu_data.icache.linesz);
			return 0;
		case 2:		/* Read count register */
			regs->regs[rt] = read_c0_count();
			return 0;
		case 3:		/* Count register resolution */
			switch (current_cpu_data.cputype) {
			case CPU_20KC:
			case CPU_25KF:
				regs->regs[rt] = 1;
				break;
			default:
				regs->regs[rt] = 2;
			}
			return 0;
		case 29:
			regs->regs[rt] = ti->tp_value;
			return 0;
		default:
			return -1;
		}
	}

	/* Not ours.  */
	return -1;
}

static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
{
	if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
				1, regs, 0);
		return 0;
	}

	return -1;			/* Must be something else ... */
}

asmlinkage void do_ov(struct pt_regs *regs)
{
	siginfo_t info;

	die_if_kernel("Integer overflow", regs);

	info.si_code = FPE_INTOVF;
	info.si_signo = SIGFPE;
	info.si_errno = 0;
	info.si_addr = (void __user *) regs->cp0_epc;
	force_sig_info(SIGFPE, &info, current);
}

static int process_fpemu_return(int sig, void __user *fault_addr)
{
	if (sig == SIGSEGV || sig == SIGBUS) {
		struct siginfo si = {0};
		si.si_addr = fault_addr;
		si.si_signo = sig;
		if (sig == SIGSEGV) {
			if (find_vma(current->mm, (unsigned long)fault_addr))
				si.si_code = SEGV_ACCERR;
			else
				si.si_code = SEGV_MAPERR;
		} else {
			si.si_code = BUS_ADRERR;
		}
		force_sig_info(sig, &si, current);
		return 1;
	} else if (sig) {
		force_sig(sig, current);
		return 1;
	} else {
		return 0;
	}
}

/*
 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
 */
asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
{
	siginfo_t info = {0};

	if (notify_die(DIE_FP, "FP exception", regs, 0, regs_to_trapnr(regs), SIGFPE)
	    == NOTIFY_STOP)
		return;
	die_if_kernel("FP exception in kernel code", regs);

	if (fcr31 & FPU_CSR_UNI_X) {
		int sig;
		void __user *fault_addr = NULL;

		/*
		 * Unimplemented operation exception.  If we've got the full
		 * software emulator on-board, let's use it...
		 *
		 * Force FPU to dump state into task/thread context.  We're
		 * moving a lot of data here for what is probably a single
		 * instruction, but the alternative is to pre-decode the FP
		 * register operands before invoking the emulator, which seems
		 * a bit extreme for what should be an infrequent event.
		 */
		/* Ensure 'resume' not overwrite saved fp context again. */
		lose_fpu(1);

		/* Run the emulator */
		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
					       &fault_addr);

		/*
		 * We can't allow the emulated instruction to leave any of
		 * the cause bit set in $fcr31.
		 */
		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;

		/* Restore the hardware register state */
		own_fpu(1);	/* Using the FPU again.  */

		/* If something went wrong, signal */
		process_fpemu_return(sig, fault_addr);

		return;
	} else if (fcr31 & FPU_CSR_INV_X)
		info.si_code = FPE_FLTINV;
	else if (fcr31 & FPU_CSR_DIV_X)
		info.si_code = FPE_FLTDIV;
	else if (fcr31 & FPU_CSR_OVF_X)
		info.si_code = FPE_FLTOVF;
	else if (fcr31 & FPU_CSR_UDF_X)
		info.si_code = FPE_FLTUND;
	else if (fcr31 & FPU_CSR_INE_X)
		info.si_code = FPE_FLTRES;
	else
		info.si_code = __SI_FAULT;
	info.si_signo = SIGFPE;
	info.si_errno = 0;
	info.si_addr = (void __user *) regs->cp0_epc;
	force_sig_info(SIGFPE, &info, current);
}

static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
	const char *str)
{
	siginfo_t info;
	char b[40];

#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
	if (kgdb_ll_trap(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
		return;
#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */

	if (notify_die(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
		return;

	/*
	 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
	 * insns, even for trap and break codes that indicate arithmetic
	 * failures.  Weird ...
	 * But should we continue the brokenness???  --macro
	 */
	switch (code) {
	case BRK_OVERFLOW:
	case BRK_DIVZERO:
		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
		die_if_kernel(b, regs);
		if (code == BRK_DIVZERO)
			info.si_code = FPE_INTDIV;
		else
			info.si_code = FPE_INTOVF;
		info.si_signo = SIGFPE;
		info.si_errno = 0;
		info.si_addr = (void __user *) regs->cp0_epc;
		force_sig_info(SIGFPE, &info, current);
		break;
	case BRK_BUG:
		die_if_kernel("Kernel bug detected", regs);
		force_sig(SIGTRAP, current);
		break;
	case BRK_MEMU:
		/*
		 * Address errors may be deliberately induced by the FPU
		 * emulator to retake control of the CPU after executing the
		 * instruction in the delay slot of an emulated branch.
		 *
		 * Terminate if exception was recognized as a delay slot return
		 * otherwise handle as normal.
		 */
		if (do_dsemulret(regs))
			return;

		die_if_kernel("Math emu break/trap", regs);
		force_sig(SIGTRAP, current);
		break;
	default:
		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
		die_if_kernel(b, regs);
		force_sig(SIGTRAP, current);
	}
}

asmlinkage void do_bp(struct pt_regs *regs)
{
	unsigned int opcode, bcode;

	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
		goto out_sigsegv;

	/*
	 * There is the ancient bug in the MIPS assemblers that the break
	 * code starts left to bit 16 instead to bit 6 in the opcode.
	 * Gas is bug-compatible, but not always, grrr...
	 * We handle both cases with a simple heuristics.  --macro
	 */
	bcode = ((opcode >> 6) & ((1 << 20) - 1));
	if (bcode >= (1 << 10))
		bcode >>= 10;

	/*
	 * notify the kprobe handlers, if instruction is likely to
	 * pertain to them.
	 */
	switch (bcode) {
	case BRK_KPROBE_BP:
		if (notify_die(DIE_BREAK, "debug", regs, bcode, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
			return;
		else
			break;
	case BRK_KPROBE_SSTEPBP:
		if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
			return;
		else
			break;
	default:
		break;
	}

	do_trap_or_bp(regs, bcode, "Break");
	return;

out_sigsegv:
	force_sig(SIGSEGV, current);
}

asmlinkage void do_tr(struct pt_regs *regs)
{
	unsigned int opcode, tcode = 0;

	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
		goto out_sigsegv;

	/* Immediate versions don't provide a code.  */
	if (!(opcode & OPCODE))
		tcode = ((opcode >> 6) & ((1 << 10) - 1));

	do_trap_or_bp(regs, tcode, "Trap");
	return;

out_sigsegv:
	force_sig(SIGSEGV, current);
}

asmlinkage void do_ri(struct pt_regs *regs)
{
	unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
	unsigned long old_epc = regs->cp0_epc;
	unsigned int opcode = 0;
	int status = -1;

	if (notify_die(DIE_RI, "RI Fault", regs, 0, regs_to_trapnr(regs), SIGILL)
	    == NOTIFY_STOP)
		return;

	die_if_kernel("Reserved instruction in kernel code", regs);

	if (unlikely(compute_return_epc(regs) < 0))
		return;

	if (unlikely(get_user(opcode, epc) < 0))
		status = SIGSEGV;

	if (!cpu_has_llsc && status < 0)
		status = simulate_llsc(regs, opcode);

	if (status < 0)
		status = simulate_rdhwr(regs, opcode);

	if (status < 0)
		status = simulate_sync(regs, opcode);

	if (status < 0)
		status = SIGILL;

	if (unlikely(status > 0)) {
		regs->cp0_epc = old_epc;		/* Undo skip-over.  */
		force_sig(status, current);
	}
}

/*
 * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
 * emulated more than some threshold number of instructions, force migration to
 * a "CPU" that has FP support.
 */
static void mt_ase_fp_affinity(void)
{
#ifdef CONFIG_MIPS_MT_FPAFF
	if (mt_fpemul_threshold > 0 &&
	     ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
		/*
		 * If there's no FPU present, or if the application has already
		 * restricted the allowed set to exclude any CPUs with FPUs,
		 * we'll skip the procedure.
		 */
		if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
			cpumask_t tmask;

			current->thread.user_cpus_allowed
				= current->cpus_allowed;
			cpus_and(tmask, current->cpus_allowed,
				mt_fpu_cpumask);
			set_cpus_allowed_ptr(current, &tmask);
			set_thread_flag(TIF_FPUBOUND);
		}
	}
#endif /* CONFIG_MIPS_MT_FPAFF */
}

/*
 * No lock; only written during early bootup by CPU 0.
 */
static RAW_NOTIFIER_HEAD(cu2_chain);

int __ref register_cu2_notifier(struct notifier_block *nb)
{
	return raw_notifier_chain_register(&cu2_chain, nb);
}

int cu2_notifier_call_chain(unsigned long val, void *v)
{
	return raw_notifier_call_chain(&cu2_chain, val, v);
}

static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
        void *data)
{
	struct pt_regs *regs = data;

	switch (action) {
	default:
		die_if_kernel("Unhandled kernel unaligned access or invalid "
			      "instruction", regs);
		/* Fall through  */

	case CU2_EXCEPTION:
		force_sig(SIGILL, current);
	}

	return NOTIFY_OK;
}

asmlinkage void do_cpu(struct pt_regs *regs)
{
	unsigned int __user *epc;
	unsigned long old_epc;
	unsigned int opcode;
	unsigned int cpid;
	int status;
	unsigned long __maybe_unused flags;

	die_if_kernel("do_cpu invoked from kernel context!", regs);

	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;

	switch (cpid) {
	case 0:
		epc = (unsigned int __user *)exception_epc(regs);
		old_epc = regs->cp0_epc;
		opcode = 0;
		status = -1;

		if (unlikely(compute_return_epc(regs) < 0))
			return;

		if (unlikely(get_user(opcode, epc) < 0))
			status = SIGSEGV;

		if (!cpu_has_llsc && status < 0)
			status = simulate_llsc(regs, opcode);

		if (status < 0)
			status = simulate_rdhwr(regs, opcode);

		if (status < 0)
			status = SIGILL;

		if (unlikely(status > 0)) {
			regs->cp0_epc = old_epc;	/* Undo skip-over.  */
			force_sig(status, current);
		}

		return;

	case 1:
		if (used_math())	/* Using the FPU again.  */
			own_fpu(1);
		else {			/* First time FPU user.  */
			init_fpu();
			set_used_math();
		}

		if (!raw_cpu_has_fpu) {
			int sig;
			void __user *fault_addr = NULL;
			sig = fpu_emulator_cop1Handler(regs,
						       &current->thread.fpu,
						       0, &fault_addr);
			if (!process_fpemu_return(sig, fault_addr))
				mt_ase_fp_affinity();
		}

		return;

	case 2:
		raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
		return;

	case 3:
		break;
	}

	force_sig(SIGILL, current);
}

asmlinkage void do_mdmx(struct pt_regs *regs)
{
	force_sig(SIGILL, current);
}

/*
 * Called with interrupts disabled.
 */
asmlinkage void do_watch(struct pt_regs *regs)
{
	u32 cause;

	/*
	 * Clear WP (bit 22) bit of cause register so we don't loop
	 * forever.
	 */
	cause = read_c0_cause();
	cause &= ~(1 << 22);
	write_c0_cause(cause);

	/*
	 * If the current thread has the watch registers loaded, save
	 * their values and send SIGTRAP.  Otherwise another thread
	 * left the registers set, clear them and continue.
	 */
	if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
		mips_read_watch_registers();
		local_irq_enable();
		force_sig(SIGTRAP, current);
	} else {
		mips_clear_watch_registers();
		local_irq_enable();
	}
}

asmlinkage void do_mcheck(struct pt_regs *regs)
{
	const int field = 2 * sizeof(unsigned long);
	int multi_match = regs->cp0_status & ST0_TS;

	show_regs(regs);

	if (multi_match) {
		printk("Index   : %0x\n", read_c0_index());
		printk("Pagemask: %0x\n", read_c0_pagemask());
		printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
		printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
		printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
		printk("\n");
		dump_tlb_all();
	}

	show_code((unsigned int __user *) regs->cp0_epc);

	/*
	 * Some chips may have other causes of machine check (e.g. SB1
	 * graduation timer)
	 */
	panic("Caught Machine Check exception - %scaused by multiple "
	      "matching entries in the TLB.",
	      (multi_match) ? "" : "not ");
}

asmlinkage void do_mt(struct pt_regs *regs)
{
	int subcode;

	subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
			>> VPECONTROL_EXCPT_SHIFT;
	switch (subcode) {
	case 0:
		printk(KERN_DEBUG "Thread Underflow\n");
		break;
	case 1:
		printk(KERN_DEBUG "Thread Overflow\n");
		break;
	case 2:
		printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
		break;
	case 3:
		printk(KERN_DEBUG "Gating Storage Exception\n");
		break;
	case 4:
		printk(KERN_DEBUG "YIELD Scheduler Exception\n");
		break;
	case 5:
		printk(KERN_DEBUG "Gating Storage Schedulier Exception\n");
		break;
	default:
		printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
			subcode);
		break;
	}
	die_if_kernel("MIPS MT Thread exception in kernel", regs);

	force_sig(SIGILL, current);
}


asmlinkage void do_dsp(struct pt_regs *regs)
{
	if (cpu_has_dsp)
		panic("Unexpected DSP exception\n");

	force_sig(SIGILL, current);
}

asmlinkage void do_reserved(struct pt_regs *regs)
{
	/*
	 * Game over - no way to handle this if it ever occurs.  Most probably
	 * caused by a new unknown cpu type or after another deadly
	 * hard/software error.
	 */
	show_regs(regs);
	panic("Caught reserved exception %ld - should not happen.",
	      (regs->cp0_cause & 0x7f) >> 2);
}

static int __initdata l1parity = 1;
static int __init nol1parity(char *s)
{
	l1parity = 0;
	return 1;
}
__setup("nol1par", nol1parity);
static int __initdata l2parity = 1;
static int __init nol2parity(char *s)
{
	l2parity = 0;
	return 1;
}
__setup("nol2par", nol2parity);

/*
 * Some MIPS CPUs can enable/disable for cache parity detection, but do
 * it different ways.
 */
static inline void parity_protection_init(void)
{
	switch (current_cpu_type()) {
	case CPU_24K:
	case CPU_34K:
	case CPU_74K:
	case CPU_1004K:
		{
#define ERRCTL_PE	0x80000000
#define ERRCTL_L2P	0x00800000
			unsigned long errctl;
			unsigned int l1parity_present, l2parity_present;

			errctl = read_c0_ecc();
			errctl &= ~(ERRCTL_PE|ERRCTL_L2P);

			/* probe L1 parity support */
			write_c0_ecc(errctl | ERRCTL_PE);
			back_to_back_c0_hazard();
			l1parity_present = (read_c0_ecc() & ERRCTL_PE);

			/* probe L2 parity support */
			write_c0_ecc(errctl|ERRCTL_L2P);
			back_to_back_c0_hazard();
			l2parity_present = (read_c0_ecc() & ERRCTL_L2P);

			if (l1parity_present && l2parity_present) {
				if (l1parity)
					errctl |= ERRCTL_PE;
				if (l1parity ^ l2parity)
					errctl |= ERRCTL_L2P;
			} else if (l1parity_present) {
				if (l1parity)
					errctl |= ERRCTL_PE;
			} else if (l2parity_present) {
				if (l2parity)
					errctl |= ERRCTL_L2P;
			} else {
				/* No parity available */
			}

			printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);

			write_c0_ecc(errctl);
			back_to_back_c0_hazard();
			errctl = read_c0_ecc();
			printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);

			if (l1parity_present)
				printk(KERN_INFO "Cache parity protection %sabled\n",
				       (errctl & ERRCTL_PE) ? "en" : "dis");

			if (l2parity_present) {
				if (l1parity_present && l1parity)
					errctl ^= ERRCTL_L2P;
				printk(KERN_INFO "L2 cache parity protection %sabled\n",
				       (errctl & ERRCTL_L2P) ? "en" : "dis");
			}
		}
		break;

	case CPU_5KC:
		write_c0_ecc(0x80000000);
		back_to_back_c0_hazard();
		/* Set the PE bit (bit 31) in the c0_errctl register. */
		printk(KERN_INFO "Cache parity protection %sabled\n",
		       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
		break;
	case CPU_20KC:
	case CPU_25KF:
		/* Clear the DE bit (bit 16) in the c0_status register. */
		printk(KERN_INFO "Enable cache parity protection for "
		       "MIPS 20KC/25KF CPUs.\n");
		clear_c0_status(ST0_DE);
		break;
	default:
		break;
	}
}

asmlinkage void cache_parity_error(void)
{
	const int field = 2 * sizeof(unsigned long);
	unsigned int reg_val;

	/* For the moment, report the problem and hang. */
	printk("Cache error exception:\n");
	printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
	reg_val = read_c0_cacheerr();
	printk("c0_cacheerr == %08x\n", reg_val);

	printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
	       reg_val & (1<<30) ? "secondary" : "primary",
	       reg_val & (1<<31) ? "data" : "insn");
	printk("Error bits: %s%s%s%s%s%s%s\n",
	       reg_val & (1<<29) ? "ED " : "",
	       reg_val & (1<<28) ? "ET " : "",
	       reg_val & (1<<26) ? "EE " : "",
	       reg_val & (1<<25) ? "EB " : "",
	       reg_val & (1<<24) ? "EI " : "",
	       reg_val & (1<<23) ? "E1 " : "",
	       reg_val & (1<<22) ? "E0 " : "");
	printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));

#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
	if (reg_val & (1<<22))
		printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());

	if (reg_val & (1<<23))
		printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
#endif

	panic("Can't handle the cache error!");
}

/*
 * SDBBP EJTAG debug exception handler.
 * We skip the instruction and return to the next instruction.
 */
void ejtag_exception_handler(struct pt_regs *regs)
{
	const int field = 2 * sizeof(unsigned long);
	unsigned long depc, old_epc;
	unsigned int debug;

	printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
	depc = read_c0_depc();
	debug = read_c0_debug();
	printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
	if (debug & 0x80000000) {
		/*
		 * In branch delay slot.
		 * We cheat a little bit here and use EPC to calculate the
		 * debug return address (DEPC). EPC is restored after the
		 * calculation.
		 */
		old_epc = regs->cp0_epc;
		regs->cp0_epc = depc;
		__compute_return_epc(regs);
		depc = regs->cp0_epc;
		regs->cp0_epc = old_epc;
	} else
		depc += 4;
	write_c0_depc(depc);

#if 0
	printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
	write_c0_debug(debug | 0x100);
#endif
}

/*
 * NMI exception handler.
 */
NORET_TYPE void ATTRIB_NORET nmi_exception_handler(struct pt_regs *regs)
{
	bust_spinlocks(1);
	printk("NMI taken!!!!\n");
	die("NMI", regs);
}

#define VECTORSPACING 0x100	/* for EI/VI mode */

unsigned long ebase;
unsigned long exception_handlers[32];
unsigned long vi_handlers[64];

void __init *set_except_vector(int n, void *addr)
{
	unsigned long handler = (unsigned long) addr;
	unsigned long old_handler = exception_handlers[n];

	exception_handlers[n] = handler;
	if (n == 0 && cpu_has_divec) {
		unsigned long jump_mask = ~((1 << 28) - 1);
		u32 *buf = (u32 *)(ebase + 0x200);
		unsigned int k0 = 26;
		if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
			uasm_i_j(&buf, handler & ~jump_mask);
			uasm_i_nop(&buf);
		} else {
			UASM_i_LA(&buf, k0, handler);
			uasm_i_jr(&buf, k0);
			uasm_i_nop(&buf);
		}
		local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
	}
	return (void *)old_handler;
}

static asmlinkage void do_default_vi(void)
{
	show_regs(get_irq_regs());
	panic("Caught unexpected vectored interrupt.");
}

static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
{
	unsigned long handler;
	unsigned long old_handler = vi_handlers[n];
	int srssets = current_cpu_data.srsets;
	u32 *w;
	unsigned char *b;

	BUG_ON(!cpu_has_veic && !cpu_has_vint);

	if (addr == NULL) {
		handler = (unsigned long) do_default_vi;
		srs = 0;
	} else
		handler = (unsigned long) addr;
	vi_handlers[n] = (unsigned long) addr;

	b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);

	if (srs >= srssets)
		panic("Shadow register set %d not supported", srs);

	if (cpu_has_veic) {
		if (board_bind_eic_interrupt)
			board_bind_eic_interrupt(n, srs);
	} else if (cpu_has_vint) {
		/* SRSMap is only defined if shadow sets are implemented */
		if (srssets > 1)
			change_c0_srsmap(0xf << n*4, srs << n*4);
	}

	if (srs == 0) {
		/*
		 * If no shadow set is selected then use the default handler
		 * that does normal register saving and a standard interrupt exit
		 */

		extern char except_vec_vi, except_vec_vi_lui;
		extern char except_vec_vi_ori, except_vec_vi_end;
		extern char rollback_except_vec_vi;
		char *vec_start = (cpu_wait == r4k_wait) ?
			&rollback_except_vec_vi : &except_vec_vi;
#ifdef CONFIG_MIPS_MT_SMTC
		/*
		 * We need to provide the SMTC vectored interrupt handler
		 * not only with the address of the handler, but with the
		 * Status.IM bit to be masked before going there.
		 */
		extern char except_vec_vi_mori;
		const int mori_offset = &except_vec_vi_mori - vec_start;
#endif /* CONFIG_MIPS_MT_SMTC */
		const int handler_len = &except_vec_vi_end - vec_start;
		const int lui_offset = &except_vec_vi_lui - vec_start;
		const int ori_offset = &except_vec_vi_ori - vec_start;

		if (handler_len > VECTORSPACING) {
			/*
			 * Sigh... panicing won't help as the console
			 * is probably not configured :(
			 */
			panic("VECTORSPACING too small");
		}

		memcpy(b, vec_start, handler_len);
#ifdef CONFIG_MIPS_MT_SMTC
		BUG_ON(n > 7);	/* Vector index %d exceeds SMTC maximum. */

		w = (u32 *)(b + mori_offset);
		*w = (*w & 0xffff0000) | (0x100 << n);
#endif /* CONFIG_MIPS_MT_SMTC */
		w = (u32 *)(b + lui_offset);
		*w = (*w & 0xffff0000) | (((u32)handler >> 16) & 0xffff);
		w = (u32 *)(b + ori_offset);
		*w = (*w & 0xffff0000) | ((u32)handler & 0xffff);
		local_flush_icache_range((unsigned long)b,
					 (unsigned long)(b+handler_len));
	}
	else {
		/*
		 * In other cases jump directly to the interrupt handler
		 *
		 * It is the handlers responsibility to save registers if required
		 * (eg hi/lo) and return from the exception using "eret"
		 */
		w = (u32 *)b;
		*w++ = 0x08000000 | (((u32)handler >> 2) & 0x03fffff); /* j handler */
		*w = 0;
		local_flush_icache_range((unsigned long)b,
					 (unsigned long)(b+8));
	}

	return (void *)old_handler;
}

void *set_vi_handler(int n, vi_handler_t addr)
{
	return set_vi_srs_handler(n, addr, 0);
}

extern void cpu_cache_init(void);
extern void tlb_init(void);
extern void flush_tlb_handlers(void);

/*
 * Timer interrupt
 */
int cp0_compare_irq;
int cp0_compare_irq_shift;

/*
 * Performance counter IRQ or -1 if shared with timer
 */
int cp0_perfcount_irq;
EXPORT_SYMBOL_GPL(cp0_perfcount_irq);

static int __cpuinitdata noulri;

static int __init ulri_disable(char *s)
{
	pr_info("Disabling ulri\n");
	noulri = 1;

	return 1;
}
__setup("noulri", ulri_disable);

void __cpuinit per_cpu_trap_init(void)
{
	unsigned int cpu = smp_processor_id();
	unsigned int status_set = ST0_CU0;
	unsigned int hwrena = cpu_hwrena_impl_bits;
#ifdef CONFIG_MIPS_MT_SMTC
	int secondaryTC = 0;
	int bootTC = (cpu == 0);

	/*
	 * Only do per_cpu_trap_init() for first TC of Each VPE.
	 * Note that this hack assumes that the SMTC init code
	 * assigns TCs consecutively and in ascending order.
	 */

	if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
	    ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
		secondaryTC = 1;
#endif /* CONFIG_MIPS_MT_SMTC */

	/*
	 * Disable coprocessors and select 32-bit or 64-bit addressing
	 * and the 16/32 or 32/32 FPR register model.  Reset the BEV
	 * flag that some firmware may have left set and the TS bit (for
	 * IP27).  Set XX for ISA IV code to work.
	 */
#ifdef CONFIG_64BIT
	status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
#endif
	if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
		status_set |= ST0_XX;
	if (cpu_has_dsp)
		status_set |= ST0_MX;

	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
			 status_set);

	if (cpu_has_mips_r2)
		hwrena |= 0x0000000f;

	if (!noulri && cpu_has_userlocal)
		hwrena |= (1 << 29);

	if (hwrena)
		write_c0_hwrena(hwrena);

#ifdef CONFIG_MIPS_MT_SMTC
	if (!secondaryTC) {
#endif /* CONFIG_MIPS_MT_SMTC */

	if (cpu_has_veic || cpu_has_vint) {
		unsigned long sr = set_c0_status(ST0_BEV);
		write_c0_ebase(ebase);
		write_c0_status(sr);
		/* Setting vector spacing enables EI/VI mode  */
		change_c0_intctl(0x3e0, VECTORSPACING);
	}
	if (cpu_has_divec) {
		if (cpu_has_mipsmt) {
			unsigned int vpflags = dvpe();
			set_c0_cause(CAUSEF_IV);
			evpe(vpflags);
		} else
			set_c0_cause(CAUSEF_IV);
	}

	/*
	 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
	 *
	 *  o read IntCtl.IPTI to determine the timer interrupt
	 *  o read IntCtl.IPPCI to determine the performance counter interrupt
	 */
	if (cpu_has_mips_r2) {
		cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
		cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
		cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
		if (cp0_perfcount_irq == cp0_compare_irq)
			cp0_perfcount_irq = -1;
	} else {
		cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
		cp0_compare_irq_shift = cp0_compare_irq;
		cp0_perfcount_irq = -1;
	}

#ifdef CONFIG_MIPS_MT_SMTC
	}
#endif /* CONFIG_MIPS_MT_SMTC */

	cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;

	atomic_inc(&init_mm.mm_count);
	current->active_mm = &init_mm;
	BUG_ON(current->mm);
	enter_lazy_tlb(&init_mm, current);

#ifdef CONFIG_MIPS_MT_SMTC
	if (bootTC) {
#endif /* CONFIG_MIPS_MT_SMTC */
		cpu_cache_init();
		tlb_init();
#ifdef CONFIG_MIPS_MT_SMTC
	} else if (!secondaryTC) {
		/*
		 * First TC in non-boot VPE must do subset of tlb_init()
		 * for MMU countrol registers.
		 */
		write_c0_pagemask(PM_DEFAULT_MASK);
		write_c0_wired(0);
	}
#endif /* CONFIG_MIPS_MT_SMTC */
	TLBMISS_HANDLER_SETUP();
}

/* Install CPU exception handler */
void __init set_handler(unsigned long offset, void *addr, unsigned long size)
{
	memcpy((void *)(ebase + offset), addr, size);
	local_flush_icache_range(ebase + offset, ebase + offset + size);
}

static char panic_null_cerr[] __cpuinitdata =
	"Trying to set NULL cache error exception handler";

/*
 * Install uncached CPU exception handler.
 * This is suitable only for the cache error exception which is the only
 * exception handler that is being run uncached.
 */
void __cpuinit set_uncached_handler(unsigned long offset, void *addr,
	unsigned long size)
{
	unsigned long uncached_ebase = CKSEG1ADDR(ebase);

	if (!addr)
		panic(panic_null_cerr);

	memcpy((void *)(uncached_ebase + offset), addr, size);
}

static int __initdata rdhwr_noopt;
static int __init set_rdhwr_noopt(char *str)
{
	rdhwr_noopt = 1;
	return 1;
}

__setup("rdhwr_noopt", set_rdhwr_noopt);

void __init trap_init(void)
{
	extern char except_vec3_generic, except_vec3_r4000;
	extern char except_vec4;
	unsigned long i;
	int rollback;

	check_wait();
	rollback = (cpu_wait == r4k_wait);

#if defined(CONFIG_KGDB)
	if (kgdb_early_setup)
		return;	/* Already done */
#endif

	if (cpu_has_veic || cpu_has_vint) {
		unsigned long size = 0x200 + VECTORSPACING*64;
		ebase = (unsigned long)
			__alloc_bootmem(size, 1 << fls(size), 0);
	} else {
		ebase = CKSEG0;
		if (cpu_has_mips_r2)
			ebase += (read_c0_ebase() & 0x3ffff000);
	}

	per_cpu_trap_init();

	/*
	 * Copy the generic exception handlers to their final destination.
	 * This will be overriden later as suitable for a particular
	 * configuration.
	 */
	set_handler(0x180, &except_vec3_generic, 0x80);

	/*
	 * Setup default vectors
	 */
	for (i = 0; i <= 31; i++)
		set_except_vector(i, handle_reserved);

	/*
	 * Copy the EJTAG debug exception vector handler code to it's final
	 * destination.
	 */
	if (cpu_has_ejtag && board_ejtag_handler_setup)
		board_ejtag_handler_setup();

	/*
	 * Only some CPUs have the watch exceptions.
	 */
	if (cpu_has_watch)
		set_except_vector(23, handle_watch);

	/*
	 * Initialise interrupt handlers
	 */
	if (cpu_has_veic || cpu_has_vint) {
		int nvec = cpu_has_veic ? 64 : 8;
		for (i = 0; i < nvec; i++)
			set_vi_handler(i, NULL);
	}
	else if (cpu_has_divec)
		set_handler(0x200, &except_vec4, 0x8);

	/*
	 * Some CPUs can enable/disable for cache parity detection, but does
	 * it different ways.
	 */
	parity_protection_init();

	/*
	 * The Data Bus Errors / Instruction Bus Errors are signaled
	 * by external hardware.  Therefore these two exceptions
	 * may have board specific handlers.
	 */
	if (board_be_init)
		board_be_init();

	set_except_vector(0, rollback ? rollback_handle_int : handle_int);
	set_except_vector(1, handle_tlbm);
	set_except_vector(2, handle_tlbl);
	set_except_vector(3, handle_tlbs);

	set_except_vector(4, handle_adel);
	set_except_vector(5, handle_ades);

	set_except_vector(6, handle_ibe);
	set_except_vector(7, handle_dbe);

	set_except_vector(8, handle_sys);
	set_except_vector(9, handle_bp);
	set_except_vector(10, rdhwr_noopt ? handle_ri :
			  (cpu_has_vtag_icache ?
			   handle_ri_rdhwr_vivt : handle_ri_rdhwr));
	set_except_vector(11, handle_cpu);
	set_except_vector(12, handle_ov);
	set_except_vector(13, handle_tr);

	if (current_cpu_type() == CPU_R6000 ||
	    current_cpu_type() == CPU_R6000A) {
		/*
		 * The R6000 is the only R-series CPU that features a machine
		 * check exception (similar to the R4000 cache error) and
		 * unaligned ldc1/sdc1 exception.  The handlers have not been
		 * written yet.  Well, anyway there is no R6000 machine on the
		 * current list of targets for Linux/MIPS.
		 * (Duh, crap, there is someone with a triple R6k machine)
		 */
		//set_except_vector(14, handle_mc);
		//set_except_vector(15, handle_ndc);
	}


	if (board_nmi_handler_setup)
		board_nmi_handler_setup();

	if (cpu_has_fpu && !cpu_has_nofpuex)
		set_except_vector(15, handle_fpe);

	set_except_vector(22, handle_mdmx);

	if (cpu_has_mcheck)
		set_except_vector(24, handle_mcheck);

	if (cpu_has_mipsmt)
		set_except_vector(25, handle_mt);

	set_except_vector(26, handle_dsp);

	if (cpu_has_vce)
		/* Special exception: R4[04]00 uses also the divec space. */
		memcpy((void *)(ebase + 0x180), &except_vec3_r4000, 0x100);
	else if (cpu_has_4kex)
		memcpy((void *)(ebase + 0x180), &except_vec3_generic, 0x80);
	else
		memcpy((void *)(ebase + 0x080), &except_vec3_generic, 0x80);

	local_flush_icache_range(ebase, ebase + 0x400);
	flush_tlb_handlers();

	sort_extable(__start___dbe_table, __stop___dbe_table);

	cu2_notifier(default_cu2_call, 0x80000000);	/* Run last  */
}
OpenPOWER on IntegriCloud