summaryrefslogtreecommitdiff
path: root/arch/parisc/kernel/entry.S
blob: d9d3387f7c478bc6f53f12c0fa34384fefabe0c9 (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
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
 *
 * kernel entry points (interruptions, system call wrappers)
 *  Copyright (C) 1999,2000 Philipp Rumpf 
 *  Copyright (C) 1999 SuSE GmbH Nuernberg 
 *  Copyright (C) 2000 Hewlett-Packard (John Marvin)
 *  Copyright (C) 1999 Hewlett-Packard (Frank Rowand)
 */

#include <asm/asm-offsets.h>

/* we have the following possibilities to act on an interruption:
 *  - handle in assembly and use shadowed registers only
 *  - save registers to kernel stack and handle in assembly or C */


#include <asm/psw.h>
#include <asm/cache.h>		/* for L1_CACHE_SHIFT */
#include <asm/assembly.h>	/* for LDREG/STREG defines */
#include <asm/pgtable.h>
#include <asm/signal.h>
#include <asm/unistd.h>
#include <asm/ldcw.h>
#include <asm/traps.h>
#include <asm/thread_info.h>
#include <asm/alternative.h>

#include <linux/linkage.h>

#ifdef CONFIG_64BIT
	.level 2.0w
#else
	.level 2.0
#endif

	.import		pa_tlb_lock,data
	.macro  load_pa_tlb_lock reg
	mfctl		%cr25,\reg
	addil		L%(PAGE_SIZE << (PGD_ALLOC_ORDER - 1)),\reg
	.endm

	/* space_to_prot macro creates a prot id from a space id */

#if (SPACEID_SHIFT) == 0
	.macro  space_to_prot spc prot
	depd,z  \spc,62,31,\prot
	.endm
#else
	.macro  space_to_prot spc prot
	extrd,u \spc,(64 - (SPACEID_SHIFT)),32,\prot
	.endm
#endif

	/* Switch to virtual mapping, trashing only %r1 */
	.macro  virt_map
	/* pcxt_ssm_bug */
	rsm	PSW_SM_I, %r0	/* barrier for "Relied upon Translation */
	mtsp	%r0, %sr4
	mtsp	%r0, %sr5
	mtsp	%r0, %sr6
	tovirt_r1 %r29
	load32	KERNEL_PSW, %r1

	rsm     PSW_SM_QUIET,%r0	/* second "heavy weight" ctl op */
	mtctl	%r0, %cr17	/* Clear IIASQ tail */
	mtctl	%r0, %cr17	/* Clear IIASQ head */
	mtctl	%r1, %ipsw
	load32	4f, %r1
	mtctl	%r1, %cr18	/* Set IIAOQ tail */
	ldo	4(%r1), %r1
	mtctl	%r1, %cr18	/* Set IIAOQ head */
	rfir
	nop
4:
	.endm

	/*
	 * The "get_stack" macros are responsible for determining the
	 * kernel stack value.
	 *
	 *      If sr7 == 0
	 *          Already using a kernel stack, so call the
	 *          get_stack_use_r30 macro to push a pt_regs structure
	 *          on the stack, and store registers there.
	 *      else
	 *          Need to set up a kernel stack, so call the
	 *          get_stack_use_cr30 macro to set up a pointer
	 *          to the pt_regs structure contained within the
	 *          task pointer pointed to by cr30. Set the stack
	 *          pointer to point to the end of the task structure.
	 *
	 * Note that we use shadowed registers for temps until
	 * we can save %r26 and %r29. %r26 is used to preserve
	 * %r8 (a shadowed register) which temporarily contained
	 * either the fault type ("code") or the eirr. We need
	 * to use a non-shadowed register to carry the value over
	 * the rfir in virt_map. We use %r26 since this value winds
	 * up being passed as the argument to either do_cpu_irq_mask
	 * or handle_interruption. %r29 is used to hold a pointer
	 * the register save area, and once again, it needs to
	 * be a non-shadowed register so that it survives the rfir.
	 *
	 * N.B. TASK_SZ_ALGN and PT_SZ_ALGN include space for a stack frame.
	 */

	.macro  get_stack_use_cr30

	/* we save the registers in the task struct */

	copy	%r30, %r17
	mfctl   %cr30, %r1
	ldo	THREAD_SZ_ALGN(%r1), %r30
	mtsp	%r0,%sr7
	mtsp	%r16,%sr3
	tophys  %r1,%r9
	LDREG	TI_TASK(%r9), %r1	/* thread_info -> task_struct */
	tophys  %r1,%r9
	ldo     TASK_REGS(%r9),%r9
	STREG   %r17,PT_GR30(%r9)
	STREG   %r29,PT_GR29(%r9)
	STREG   %r26,PT_GR26(%r9)
	STREG	%r16,PT_SR7(%r9)
	copy    %r9,%r29
	.endm

	.macro  get_stack_use_r30

	/* we put a struct pt_regs on the stack and save the registers there */

	tophys  %r30,%r9
	copy	%r30,%r1
	ldo	PT_SZ_ALGN(%r30),%r30
	STREG   %r1,PT_GR30(%r9)
	STREG   %r29,PT_GR29(%r9)
	STREG   %r26,PT_GR26(%r9)
	STREG	%r16,PT_SR7(%r9)
	copy    %r9,%r29
	.endm

	.macro  rest_stack
	LDREG   PT_GR1(%r29), %r1
	LDREG   PT_GR30(%r29),%r30
	LDREG   PT_GR29(%r29),%r29
	.endm

	/* default interruption handler
	 * (calls traps.c:handle_interruption) */
	.macro	def code
	b	intr_save
	ldi     \code, %r8
	.align	32
	.endm

	/* Interrupt interruption handler
	 * (calls irq.c:do_cpu_irq_mask) */
	.macro	extint code
	b	intr_extint
	mfsp    %sr7,%r16
	.align	32
	.endm	

	.import	os_hpmc, code

	/* HPMC handler */
	.macro	hpmc code
	nop			/* must be a NOP, will be patched later */
	load32	PA(os_hpmc), %r3
	bv,n	0(%r3)
	nop
	.word	0		/* checksum (will be patched) */
	.word	0		/* address of handler */
	.word	0		/* length of handler */
	.endm

	/*
	 * Performance Note: Instructions will be moved up into
	 * this part of the code later on, once we are sure
	 * that the tlb miss handlers are close to final form.
	 */

	/* Register definitions for tlb miss handler macros */

	va  = r8	/* virtual address for which the trap occurred */
	spc = r24	/* space for which the trap occurred */

#ifndef CONFIG_64BIT

	/*
	 * itlb miss interruption handler (parisc 1.1 - 32 bit)
	 */

	.macro	itlb_11 code

	mfctl	%pcsq, spc
	b	itlb_miss_11
	mfctl	%pcoq, va

	.align		32
	.endm
#endif
	
	/*
	 * itlb miss interruption handler (parisc 2.0)
	 */

	.macro	itlb_20 code
	mfctl	%pcsq, spc
#ifdef CONFIG_64BIT
	b       itlb_miss_20w
#else
	b	itlb_miss_20
#endif
	mfctl	%pcoq, va

	.align		32
	.endm
	
#ifndef CONFIG_64BIT
	/*
	 * naitlb miss interruption handler (parisc 1.1 - 32 bit)
	 */

	.macro	naitlb_11 code

	mfctl	%isr,spc
	b	naitlb_miss_11
	mfctl 	%ior,va

	.align		32
	.endm
#endif
	
	/*
	 * naitlb miss interruption handler (parisc 2.0)
	 */

	.macro	naitlb_20 code

	mfctl	%isr,spc
#ifdef CONFIG_64BIT
	b       naitlb_miss_20w
#else
	b	naitlb_miss_20
#endif
	mfctl 	%ior,va

	.align		32
	.endm
	
#ifndef CONFIG_64BIT
	/*
	 * dtlb miss interruption handler (parisc 1.1 - 32 bit)
	 */

	.macro	dtlb_11 code

	mfctl	%isr, spc
	b	dtlb_miss_11
	mfctl	%ior, va

	.align		32
	.endm
#endif

	/*
	 * dtlb miss interruption handler (parisc 2.0)
	 */

	.macro	dtlb_20 code

	mfctl	%isr, spc
#ifdef CONFIG_64BIT
	b       dtlb_miss_20w
#else
	b	dtlb_miss_20
#endif
	mfctl	%ior, va

	.align		32
	.endm
	
#ifndef CONFIG_64BIT
	/* nadtlb miss interruption handler (parisc 1.1 - 32 bit) */

	.macro	nadtlb_11 code

	mfctl	%isr,spc
	b       nadtlb_miss_11
	mfctl	%ior,va

	.align		32
	.endm
#endif
	
	/* nadtlb miss interruption handler (parisc 2.0) */

	.macro	nadtlb_20 code

	mfctl	%isr,spc
#ifdef CONFIG_64BIT
	b       nadtlb_miss_20w
#else
	b       nadtlb_miss_20
#endif
	mfctl	%ior,va

	.align		32
	.endm
	
#ifndef CONFIG_64BIT
	/*
	 * dirty bit trap interruption handler (parisc 1.1 - 32 bit)
	 */

	.macro	dbit_11 code

	mfctl	%isr,spc
	b	dbit_trap_11
	mfctl	%ior,va

	.align		32
	.endm
#endif

	/*
	 * dirty bit trap interruption handler (parisc 2.0)
	 */

	.macro	dbit_20 code

	mfctl	%isr,spc
#ifdef CONFIG_64BIT
	b       dbit_trap_20w
#else
	b	dbit_trap_20
#endif
	mfctl	%ior,va

	.align		32
	.endm

	/* In LP64, the space contains part of the upper 32 bits of the
	 * fault.  We have to extract this and place it in the va,
	 * zeroing the corresponding bits in the space register */
	.macro		space_adjust	spc,va,tmp
#ifdef CONFIG_64BIT
	extrd,u		\spc,63,SPACEID_SHIFT,\tmp
	depd		%r0,63,SPACEID_SHIFT,\spc
	depd		\tmp,31,SPACEID_SHIFT,\va
#endif
	.endm

	.import		swapper_pg_dir,code

	/* Get the pgd.  For faults on space zero (kernel space), this
	 * is simply swapper_pg_dir.  For user space faults, the
	 * pgd is stored in %cr25 */
	.macro		get_pgd		spc,reg
	ldil		L%PA(swapper_pg_dir),\reg
	ldo		R%PA(swapper_pg_dir)(\reg),\reg
	or,COND(=)	%r0,\spc,%r0
	mfctl		%cr25,\reg
	.endm

	/* 
		space_check(spc,tmp,fault)

		spc - The space we saw the fault with.
		tmp - The place to store the current space.
		fault - Function to call on failure.

		Only allow faults on different spaces from the
		currently active one if we're the kernel 

	*/
	.macro		space_check	spc,tmp,fault
	mfsp		%sr7,\tmp
	/* check against %r0 which is same value as LINUX_GATEWAY_SPACE */
	or,COND(<>)	%r0,\spc,%r0	/* user may execute gateway page
					 * as kernel, so defeat the space
					 * check if it is */
	copy		\spc,\tmp
	or,COND(=)	%r0,\tmp,%r0	/* nullify if executing as kernel */
	cmpb,COND(<>),n	\tmp,\spc,\fault
	.endm

	/* Look up a PTE in a 2-Level scheme (faulting at each
	 * level if the entry isn't present 
	 *
	 * NOTE: we use ldw even for LP64, since the short pointers
	 * can address up to 1TB
	 */
	.macro		L2_ptep	pmd,pte,index,va,fault
#if CONFIG_PGTABLE_LEVELS == 3
	extru		\va,31-ASM_PMD_SHIFT,ASM_BITS_PER_PMD,\index
#else
# if defined(CONFIG_64BIT)
	extrd,u		\va,63-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
  #else
  # if PAGE_SIZE > 4096
	extru		\va,31-ASM_PGDIR_SHIFT,32-ASM_PGDIR_SHIFT,\index
  # else
	extru		\va,31-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
  # endif
# endif
#endif
	dep             %r0,31,PAGE_SHIFT,\pmd  /* clear offset */
	copy		%r0,\pte
	ldw,s		\index(\pmd),\pmd
	bb,>=,n		\pmd,_PxD_PRESENT_BIT,\fault
	dep		%r0,31,PxD_FLAG_SHIFT,\pmd /* clear flags */
	SHLREG		\pmd,PxD_VALUE_SHIFT,\pmd
	extru		\va,31-PAGE_SHIFT,ASM_BITS_PER_PTE,\index
	dep		%r0,31,PAGE_SHIFT,\pmd  /* clear offset */
	shladd		\index,BITS_PER_PTE_ENTRY,\pmd,\pmd /* pmd is now pte */
	.endm

	/* Look up PTE in a 3-Level scheme.
	 *
	 * Here we implement a Hybrid L2/L3 scheme: we allocate the
	 * first pmd adjacent to the pgd.  This means that we can
	 * subtract a constant offset to get to it.  The pmd and pgd
	 * sizes are arranged so that a single pmd covers 4GB (giving
	 * a full LP64 process access to 8TB) so our lookups are
	 * effectively L2 for the first 4GB of the kernel (i.e. for
	 * all ILP32 processes and all the kernel for machines with
	 * under 4GB of memory) */
	.macro		L3_ptep pgd,pte,index,va,fault
#if CONFIG_PGTABLE_LEVELS == 3 /* we might have a 2-Level scheme, e.g. with 16kb page size */
	extrd,u		\va,63-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
	ldw,s		\index(\pgd),\pgd
	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
	bb,>=,n		\pgd,_PxD_PRESENT_BIT,\fault
	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
	shld		\pgd,PxD_VALUE_SHIFT,\index
	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
	copy		\index,\pgd
	extrd,u,*<>	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
	ldo		ASM_PGD_PMD_OFFSET(\pgd),\pgd
#endif
	L2_ptep		\pgd,\pte,\index,\va,\fault
	.endm

	/* Acquire pa_tlb_lock lock and check page is present. */
	.macro		tlb_lock	spc,ptp,pte,tmp,tmp1,fault
#ifdef CONFIG_SMP
98:	cmpib,COND(=),n	0,\spc,2f
	load_pa_tlb_lock \tmp
1:	LDCW		0(\tmp),\tmp1
	cmpib,COND(=)	0,\tmp1,1b
	nop
	LDREG		0(\ptp),\pte
	bb,<,n		\pte,_PAGE_PRESENT_BIT,3f
	LDCW		0(\tmp),\tmp1
	b		\fault
	stw		\spc,0(\tmp)
99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
#endif
2:	LDREG		0(\ptp),\pte
	bb,>=,n		\pte,_PAGE_PRESENT_BIT,\fault
3:
	.endm

	/* Release pa_tlb_lock lock without reloading lock address. */
	.macro		tlb_unlock0	spc,tmp,tmp1
#ifdef CONFIG_SMP
98:	or,COND(=)	%r0,\spc,%r0
	LDCW		0(\tmp),\tmp1
	or,COND(=)	%r0,\spc,%r0
	stw		\spc,0(\tmp)
99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
#endif
	.endm

	/* Release pa_tlb_lock lock. */
	.macro		tlb_unlock1	spc,tmp,tmp1
#ifdef CONFIG_SMP
98:	load_pa_tlb_lock \tmp
99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
	tlb_unlock0	\spc,\tmp,\tmp1
#endif
	.endm

	/* Set the _PAGE_ACCESSED bit of the PTE.  Be clever and
	 * don't needlessly dirty the cache line if it was already set */
	.macro		update_accessed	ptp,pte,tmp,tmp1
	ldi		_PAGE_ACCESSED,\tmp1
	or		\tmp1,\pte,\tmp
	and,COND(<>)	\tmp1,\pte,%r0
	STREG		\tmp,0(\ptp)
	.endm

	/* Set the dirty bit (and accessed bit).  No need to be
	 * clever, this is only used from the dirty fault */
	.macro		update_dirty	ptp,pte,tmp
	ldi		_PAGE_ACCESSED|_PAGE_DIRTY,\tmp
	or		\tmp,\pte,\pte
	STREG		\pte,0(\ptp)
	.endm

	/* We have (depending on the page size):
	 * - 38 to 52-bit Physical Page Number
	 * - 12 to 26-bit page offset
	 */
	/* bitshift difference between a PFN (based on kernel's PAGE_SIZE)
	 * to a CPU TLB 4k PFN (4k => 12 bits to shift) */
	#define PAGE_ADD_SHIFT		(PAGE_SHIFT-12)
	#define PAGE_ADD_HUGE_SHIFT	(REAL_HPAGE_SHIFT-12)

	/* Drop prot bits and convert to page addr for iitlbt and idtlbt */
	.macro		convert_for_tlb_insert20 pte,tmp
#ifdef CONFIG_HUGETLB_PAGE
	copy		\pte,\tmp
	extrd,u		\tmp,(63-ASM_PFN_PTE_SHIFT)+(63-58)+PAGE_ADD_SHIFT,\
				64-PAGE_SHIFT-PAGE_ADD_SHIFT,\pte

	depdi		_PAGE_SIZE_ENCODING_DEFAULT,63,\
				(63-58)+PAGE_ADD_SHIFT,\pte
	extrd,u,*=	\tmp,_PAGE_HPAGE_BIT+32,1,%r0
	depdi		_HUGE_PAGE_SIZE_ENCODING_DEFAULT,63,\
				(63-58)+PAGE_ADD_HUGE_SHIFT,\pte
#else /* Huge pages disabled */
	extrd,u		\pte,(63-ASM_PFN_PTE_SHIFT)+(63-58)+PAGE_ADD_SHIFT,\
				64-PAGE_SHIFT-PAGE_ADD_SHIFT,\pte
	depdi		_PAGE_SIZE_ENCODING_DEFAULT,63,\
				(63-58)+PAGE_ADD_SHIFT,\pte
#endif
	.endm

	/* Convert the pte and prot to tlb insertion values.  How
	 * this happens is quite subtle, read below */
	.macro		make_insert_tlb	spc,pte,prot,tmp
	space_to_prot   \spc \prot        /* create prot id from space */
	/* The following is the real subtlety.  This is depositing
	 * T <-> _PAGE_REFTRAP
	 * D <-> _PAGE_DIRTY
	 * B <-> _PAGE_DMB (memory break)
	 *
	 * Then incredible subtlety: The access rights are
	 * _PAGE_GATEWAY, _PAGE_EXEC and _PAGE_WRITE
	 * See 3-14 of the parisc 2.0 manual
	 *
	 * Finally, _PAGE_READ goes in the top bit of PL1 (so we
	 * trigger an access rights trap in user space if the user
	 * tries to read an unreadable page */
	depd            \pte,8,7,\prot

	/* PAGE_USER indicates the page can be read with user privileges,
	 * so deposit X1|11 to PL1|PL2 (remember the upper bit of PL1
	 * contains _PAGE_READ) */
	extrd,u,*=      \pte,_PAGE_USER_BIT+32,1,%r0
	depdi		7,11,3,\prot
	/* If we're a gateway page, drop PL2 back to zero for promotion
	 * to kernel privilege (so we can execute the page as kernel).
	 * Any privilege promotion page always denys read and write */
	extrd,u,*= 	\pte,_PAGE_GATEWAY_BIT+32,1,%r0
	depd		%r0,11,2,\prot	/* If Gateway, Set PL2 to 0 */

	/* Enforce uncacheable pages.
	 * This should ONLY be use for MMIO on PA 2.0 machines.
	 * Memory/DMA is cache coherent on all PA2.0 machines we support
	 * (that means T-class is NOT supported) and the memory controllers
	 * on most of those machines only handles cache transactions.
	 */
	extrd,u,*=	\pte,_PAGE_NO_CACHE_BIT+32,1,%r0
	depdi		1,12,1,\prot

	/* Drop prot bits and convert to page addr for iitlbt and idtlbt */
	convert_for_tlb_insert20 \pte \tmp
	.endm

	/* Identical macro to make_insert_tlb above, except it
	 * makes the tlb entry for the differently formatted pa11
	 * insertion instructions */
	.macro		make_insert_tlb_11	spc,pte,prot
	zdep		\spc,30,15,\prot
	dep		\pte,8,7,\prot
	extru,=		\pte,_PAGE_NO_CACHE_BIT,1,%r0
	depi		1,12,1,\prot
	extru,=         \pte,_PAGE_USER_BIT,1,%r0
	depi		7,11,3,\prot   /* Set for user space (1 rsvd for read) */
	extru,= 	\pte,_PAGE_GATEWAY_BIT,1,%r0
	depi		0,11,2,\prot	/* If Gateway, Set PL2 to 0 */

	/* Get rid of prot bits and convert to page addr for iitlba */

	depi		0,31,ASM_PFN_PTE_SHIFT,\pte
	SHRREG		\pte,(ASM_PFN_PTE_SHIFT-(31-26)),\pte
	.endm

	/* This is for ILP32 PA2.0 only.  The TLB insertion needs
	 * to extend into I/O space if the address is 0xfXXXXXXX
	 * so we extend the f's into the top word of the pte in
	 * this case */
	.macro		f_extend	pte,tmp
	extrd,s		\pte,42,4,\tmp
	addi,<>		1,\tmp,%r0
	extrd,s		\pte,63,25,\pte
	.endm

	/* The alias region is an 8MB aligned 16MB to do clear and
	 * copy user pages at addresses congruent with the user
	 * virtual address.
	 *
	 * To use the alias page, you set %r26 up with the to TLB
	 * entry (identifying the physical page) and %r23 up with
	 * the from tlb entry (or nothing if only a to entry---for
	 * clear_user_page_asm) */
	.macro		do_alias	spc,tmp,tmp1,va,pte,prot,fault,patype
	cmpib,COND(<>),n 0,\spc,\fault
	ldil		L%(TMPALIAS_MAP_START),\tmp
#if defined(CONFIG_64BIT) && (TMPALIAS_MAP_START >= 0x80000000)
	/* on LP64, ldi will sign extend into the upper 32 bits,
	 * which is behaviour we don't want */
	depdi		0,31,32,\tmp
#endif
	copy		\va,\tmp1
	depi		0,31,23,\tmp1
	cmpb,COND(<>),n	\tmp,\tmp1,\fault
	mfctl		%cr19,\tmp	/* iir */
	/* get the opcode (first six bits) into \tmp */
	extrw,u		\tmp,5,6,\tmp
	/*
	 * Only setting the T bit prevents data cache movein
	 * Setting access rights to zero prevents instruction cache movein
	 *
	 * Note subtlety here: _PAGE_GATEWAY, _PAGE_EXEC and _PAGE_WRITE go
	 * to type field and _PAGE_READ goes to top bit of PL1
	 */
	ldi		(_PAGE_REFTRAP|_PAGE_READ|_PAGE_WRITE),\prot
	/*
	 * so if the opcode is one (i.e. this is a memory management
	 * instruction) nullify the next load so \prot is only T.
	 * Otherwise this is a normal data operation
	 */
	cmpiclr,=	0x01,\tmp,%r0
	ldi		(_PAGE_DIRTY|_PAGE_READ|_PAGE_WRITE),\prot
.ifc \patype,20
	depd,z		\prot,8,7,\prot
.else
.ifc \patype,11
	depw,z		\prot,8,7,\prot
.else
	.error "undefined PA type to do_alias"
.endif
.endif
	/*
	 * OK, it is in the temp alias region, check whether "from" or "to".
	 * Check "subtle" note in pacache.S re: r23/r26.
	 */
#ifdef CONFIG_64BIT
	extrd,u,*=	\va,41,1,%r0
#else
	extrw,u,=	\va,9,1,%r0
#endif
	or,COND(tr)	%r23,%r0,\pte
	or		%r26,%r0,\pte
	.endm 


	/*
	 * Fault_vectors are architecturally required to be aligned on a 2K
	 * boundary
	 */

	.section .text.hot
	.align 2048

ENTRY(fault_vector_20)
	/* First vector is invalid (0) */
	.ascii	"cows can fly"
	.byte 0
	.align 32

	hpmc		 1
	def		 2
	def		 3
	extint		 4
	def		 5
	itlb_20		 PARISC_ITLB_TRAP
	def		 7
	def		 8
	def              9
	def		10
	def		11
	def		12
	def		13
	def		14
	dtlb_20		15
	naitlb_20	16
	nadtlb_20	17
	def		18
	def		19
	dbit_20		20
	def		21
	def		22
	def		23
	def		24
	def		25
	def		26
	def		27
	def		28
	def		29
	def		30
	def		31
END(fault_vector_20)

#ifndef CONFIG_64BIT

	.align 2048

ENTRY(fault_vector_11)
	/* First vector is invalid (0) */
	.ascii	"cows can fly"
	.byte 0
	.align 32

	hpmc		 1
	def		 2
	def		 3
	extint		 4
	def		 5
	itlb_11		 PARISC_ITLB_TRAP
	def		 7
	def		 8
	def              9
	def		10
	def		11
	def		12
	def		13
	def		14
	dtlb_11		15
	naitlb_11	16
	nadtlb_11	17
	def		18
	def		19
	dbit_11		20
	def		21
	def		22
	def		23
	def		24
	def		25
	def		26
	def		27
	def		28
	def		29
	def		30
	def		31
END(fault_vector_11)

#endif
	/* Fault vector is separately protected and *must* be on its own page */
	.align		PAGE_SIZE

	.import		handle_interruption,code
	.import		do_cpu_irq_mask,code

	/*
	 * Child Returns here
	 *
	 * copy_thread moved args into task save area.
	 */

ENTRY(ret_from_kernel_thread)
	/* Call schedule_tail first though */
	BL	schedule_tail, %r2
	nop

	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1
	LDREG	TASK_PT_GR25(%r1), %r26
#ifdef CONFIG_64BIT
	LDREG	TASK_PT_GR27(%r1), %r27
#endif
	LDREG	TASK_PT_GR26(%r1), %r1
	ble	0(%sr7, %r1)
	copy	%r31, %r2
	b	finish_child_return
	nop
END(ret_from_kernel_thread)


	/*
	 * struct task_struct *_switch_to(struct task_struct *prev,
	 *	struct task_struct *next)
	 *
	 * switch kernel stacks and return prev */
ENTRY_CFI(_switch_to)
	STREG	 %r2, -RP_OFFSET(%r30)

	callee_save_float
	callee_save

	load32	_switch_to_ret, %r2

	STREG	%r2, TASK_PT_KPC(%r26)
	LDREG	TASK_PT_KPC(%r25), %r2

	STREG	%r30, TASK_PT_KSP(%r26)
	LDREG	TASK_PT_KSP(%r25), %r30
	LDREG	TASK_THREAD_INFO(%r25), %r25
	bv	%r0(%r2)
	mtctl   %r25,%cr30

ENTRY(_switch_to_ret)
	mtctl	%r0, %cr0		/* Needed for single stepping */
	callee_rest
	callee_rest_float

	LDREG	-RP_OFFSET(%r30), %r2
	bv	%r0(%r2)
	copy	%r26, %r28
ENDPROC_CFI(_switch_to)

	/*
	 * Common rfi return path for interruptions, kernel execve, and
	 * sys_rt_sigreturn (sometimes).  The sys_rt_sigreturn syscall will
	 * return via this path if the signal was received when the process
	 * was running; if the process was blocked on a syscall then the
	 * normal syscall_exit path is used.  All syscalls for traced
	 * proceses exit via intr_restore.
	 *
	 * XXX If any syscalls that change a processes space id ever exit
	 * this way, then we will need to copy %sr3 in to PT_SR[3..7], and
	 * adjust IASQ[0..1].
	 *
	 */

	.align	PAGE_SIZE

ENTRY_CFI(syscall_exit_rfi)
	mfctl   %cr30,%r16
	LDREG	TI_TASK(%r16), %r16	/* thread_info -> task_struct */
	ldo	TASK_REGS(%r16),%r16
	/* Force iaoq to userspace, as the user has had access to our current
	 * context via sigcontext. Also Filter the PSW for the same reason.
	 */
	LDREG	PT_IAOQ0(%r16),%r19
	depi	3,31,2,%r19
	STREG	%r19,PT_IAOQ0(%r16)
	LDREG	PT_IAOQ1(%r16),%r19
	depi	3,31,2,%r19
	STREG	%r19,PT_IAOQ1(%r16)
	LDREG   PT_PSW(%r16),%r19
	load32	USER_PSW_MASK,%r1
#ifdef CONFIG_64BIT
	load32	USER_PSW_HI_MASK,%r20
	depd    %r20,31,32,%r1
#endif
	and     %r19,%r1,%r19 /* Mask out bits that user shouldn't play with */
	load32	USER_PSW,%r1
	or      %r19,%r1,%r19 /* Make sure default USER_PSW bits are set */
	STREG   %r19,PT_PSW(%r16)

	/*
	 * If we aren't being traced, we never saved space registers
	 * (we don't store them in the sigcontext), so set them
	 * to "proper" values now (otherwise we'll wind up restoring
	 * whatever was last stored in the task structure, which might
	 * be inconsistent if an interrupt occurred while on the gateway
	 * page). Note that we may be "trashing" values the user put in
	 * them, but we don't support the user changing them.
	 */

	STREG   %r0,PT_SR2(%r16)
	mfsp    %sr3,%r19
	STREG   %r19,PT_SR0(%r16)
	STREG   %r19,PT_SR1(%r16)
	STREG   %r19,PT_SR3(%r16)
	STREG   %r19,PT_SR4(%r16)
	STREG   %r19,PT_SR5(%r16)
	STREG   %r19,PT_SR6(%r16)
	STREG   %r19,PT_SR7(%r16)

ENTRY(intr_return)
	/* check for reschedule */
	mfctl   %cr30,%r1
	LDREG   TI_FLAGS(%r1),%r19	/* sched.h: TIF_NEED_RESCHED */
	bb,<,n	%r19,31-TIF_NEED_RESCHED,intr_do_resched /* forward */

	.import do_notify_resume,code
intr_check_sig:
	/* As above */
	mfctl   %cr30,%r1
	LDREG	TI_FLAGS(%r1),%r19
	ldi	(_TIF_SIGPENDING|_TIF_NOTIFY_RESUME), %r20
	and,COND(<>)	%r19, %r20, %r0
	b,n	intr_restore	/* skip past if we've nothing to do */

	/* This check is critical to having LWS
	 * working. The IASQ is zero on the gateway
	 * page and we cannot deliver any signals until
	 * we get off the gateway page.
	 *
	 * Only do signals if we are returning to user space
	 */
	LDREG	PT_IASQ0(%r16), %r20
	cmpib,COND(=),n LINUX_GATEWAY_SPACE, %r20, intr_restore /* backward */
	LDREG	PT_IASQ1(%r16), %r20
	cmpib,COND(=),n LINUX_GATEWAY_SPACE, %r20, intr_restore /* backward */

	/* NOTE: We need to enable interrupts if we have to deliver
	 * signals. We used to do this earlier but it caused kernel
	 * stack overflows. */
	ssm     PSW_SM_I, %r0

	copy	%r0, %r25			/* long in_syscall = 0 */
#ifdef CONFIG_64BIT
	ldo	-16(%r30),%r29			/* Reference param save area */
#endif

	BL	do_notify_resume,%r2
	copy	%r16, %r26			/* struct pt_regs *regs */

	b,n	intr_check_sig

intr_restore:
	copy            %r16,%r29
	ldo             PT_FR31(%r29),%r1
	rest_fp         %r1
	rest_general    %r29

	/* inverse of virt_map */
	pcxt_ssm_bug
	rsm             PSW_SM_QUIET,%r0	/* prepare for rfi */
	tophys_r1       %r29

	/* Restore space id's and special cr's from PT_REGS
	 * structure pointed to by r29
	 */
	rest_specials	%r29

	/* IMPORTANT: rest_stack restores r29 last (we are using it)!
	 * It also restores r1 and r30.
	 */
	rest_stack

	rfi
	nop

#ifndef CONFIG_PREEMPT
# define intr_do_preempt	intr_restore
#endif /* !CONFIG_PREEMPT */

	.import schedule,code
intr_do_resched:
	/* Only call schedule on return to userspace. If we're returning
	 * to kernel space, we may schedule if CONFIG_PREEMPT, otherwise
	 * we jump back to intr_restore.
	 */
	LDREG	PT_IASQ0(%r16), %r20
	cmpib,COND(=)	0, %r20, intr_do_preempt
	nop
	LDREG	PT_IASQ1(%r16), %r20
	cmpib,COND(=)	0, %r20, intr_do_preempt
	nop

	/* NOTE: We need to enable interrupts if we schedule.  We used
	 * to do this earlier but it caused kernel stack overflows. */
	ssm     PSW_SM_I, %r0

#ifdef CONFIG_64BIT
	ldo	-16(%r30),%r29		/* Reference param save area */
#endif

	ldil	L%intr_check_sig, %r2
#ifndef CONFIG_64BIT
	b	schedule
#else
	load32	schedule, %r20
	bv	%r0(%r20)
#endif
	ldo	R%intr_check_sig(%r2), %r2

	/* preempt the current task on returning to kernel
	 * mode from an interrupt, iff need_resched is set,
	 * and preempt_count is 0. otherwise, we continue on
	 * our merry way back to the current running task.
	 */
#ifdef CONFIG_PREEMPT
	.import preempt_schedule_irq,code
intr_do_preempt:
	rsm	PSW_SM_I, %r0		/* disable interrupts */

	/* current_thread_info()->preempt_count */
	mfctl	%cr30, %r1
	LDREG	TI_PRE_COUNT(%r1), %r19
	cmpib,COND(<>)	0, %r19, intr_restore	/* if preempt_count > 0 */
	nop				/* prev insn branched backwards */

	/* check if we interrupted a critical path */
	LDREG	PT_PSW(%r16), %r20
	bb,<,n	%r20, 31 - PSW_SM_I, intr_restore
	nop

	BL	preempt_schedule_irq, %r2
	nop

	b,n	intr_restore		/* ssm PSW_SM_I done by intr_restore */
#endif /* CONFIG_PREEMPT */

	/*
	 * External interrupts.
	 */

intr_extint:
	cmpib,COND(=),n 0,%r16,1f

	get_stack_use_cr30
	b,n 2f

1:
	get_stack_use_r30
2:
	save_specials	%r29
	virt_map
	save_general	%r29

	ldo	PT_FR0(%r29), %r24
	save_fp	%r24
	
	loadgp

	copy	%r29, %r26	/* arg0 is pt_regs */
	copy	%r29, %r16	/* save pt_regs */

	ldil	L%intr_return, %r2

#ifdef CONFIG_64BIT
	ldo	-16(%r30),%r29	/* Reference param save area */
#endif

	b	do_cpu_irq_mask
	ldo	R%intr_return(%r2), %r2	/* return to intr_return, not here */
ENDPROC_CFI(syscall_exit_rfi)


	/* Generic interruptions (illegal insn, unaligned, page fault, etc) */

ENTRY_CFI(intr_save)		/* for os_hpmc */
	mfsp    %sr7,%r16
	cmpib,COND(=),n 0,%r16,1f
	get_stack_use_cr30
	b	2f
	copy    %r8,%r26

1:
	get_stack_use_r30
	copy    %r8,%r26

2:
	save_specials	%r29

	/* If this trap is a itlb miss, skip saving/adjusting isr/ior */
	cmpib,COND(=),n        PARISC_ITLB_TRAP,%r26,skip_save_ior


	mfctl           %isr, %r16
	nop		/* serialize mfctl on PA 2.0 to avoid 4 cycle penalty */
	mfctl           %ior, %r17


#ifdef CONFIG_64BIT
	/*
	 * If the interrupted code was running with W bit off (32 bit),
	 * clear the b bits (bits 0 & 1) in the ior.
	 * save_specials left ipsw value in r8 for us to test.
	 */
	extrd,u,*<>     %r8,PSW_W_BIT,1,%r0
	depdi           0,1,2,%r17

	/* adjust isr/ior: get high bits from isr and deposit in ior */
	space_adjust	%r16,%r17,%r1
#endif
	STREG           %r16, PT_ISR(%r29)
	STREG           %r17, PT_IOR(%r29)

#if 0 && defined(CONFIG_64BIT)
	/* Revisit when we have 64-bit code above 4Gb */
	b,n		intr_save2

skip_save_ior:
	/* We have a itlb miss, and when executing code above 4 Gb on ILP64, we
	 * need to adjust iasq/iaoq here in the same way we adjusted isr/ior
	 * above.
	 */
	extrd,u,*	%r8,PSW_W_BIT,1,%r1
	cmpib,COND(=),n	1,%r1,intr_save2
	LDREG		PT_IASQ0(%r29), %r16
	LDREG		PT_IAOQ0(%r29), %r17
	/* adjust iasq/iaoq */
	space_adjust	%r16,%r17,%r1
	STREG           %r16, PT_IASQ0(%r29)
	STREG           %r17, PT_IAOQ0(%r29)
#else
skip_save_ior:
#endif

intr_save2:
	virt_map
	save_general	%r29

	ldo		PT_FR0(%r29), %r25
	save_fp		%r25
	
	loadgp

	copy		%r29, %r25	/* arg1 is pt_regs */
#ifdef CONFIG_64BIT
	ldo		-16(%r30),%r29	/* Reference param save area */
#endif

	ldil		L%intr_check_sig, %r2
	copy		%r25, %r16	/* save pt_regs */

	b		handle_interruption
	ldo		R%intr_check_sig(%r2), %r2
ENDPROC_CFI(intr_save)


	/*
	 * Note for all tlb miss handlers:
	 *
	 * cr24 contains a pointer to the kernel address space
	 * page directory.
	 *
	 * cr25 contains a pointer to the current user address
	 * space page directory.
	 *
	 * sr3 will contain the space id of the user address space
	 * of the current running thread while that thread is
	 * running in the kernel.
	 */

	/*
	 * register number allocations.  Note that these are all
	 * in the shadowed registers
	 */

	t0 = r1		/* temporary register 0 */
	va = r8		/* virtual address for which the trap occurred */
	t1 = r9		/* temporary register 1 */
	pte  = r16	/* pte/phys page # */
	prot = r17	/* prot bits */
	spc  = r24	/* space for which the trap occurred */
	ptp = r25	/* page directory/page table pointer */

#ifdef CONFIG_64BIT

dtlb_miss_20w:
	space_adjust	spc,va,t0
	get_pgd		spc,ptp
	space_check	spc,t0,dtlb_fault

	L3_ptep		ptp,pte,t0,va,dtlb_check_alias_20w

	tlb_lock	spc,ptp,pte,t0,t1,dtlb_check_alias_20w
	update_accessed	ptp,pte,t0,t1

	make_insert_tlb	spc,pte,prot,t1
	
	idtlbt          pte,prot

	tlb_unlock1	spc,t0,t1
	rfir
	nop

dtlb_check_alias_20w:
	do_alias	spc,t0,t1,va,pte,prot,dtlb_fault,20

	idtlbt          pte,prot

	rfir
	nop

nadtlb_miss_20w:
	space_adjust	spc,va,t0
	get_pgd		spc,ptp
	space_check	spc,t0,nadtlb_fault

	L3_ptep		ptp,pte,t0,va,nadtlb_check_alias_20w

	tlb_lock	spc,ptp,pte,t0,t1,nadtlb_check_alias_20w
	update_accessed	ptp,pte,t0,t1

	make_insert_tlb	spc,pte,prot,t1

	idtlbt          pte,prot

	tlb_unlock1	spc,t0,t1
	rfir
	nop

nadtlb_check_alias_20w:
	do_alias	spc,t0,t1,va,pte,prot,nadtlb_emulate,20

	idtlbt          pte,prot

	rfir
	nop

#else

dtlb_miss_11:
	get_pgd		spc,ptp

	space_check	spc,t0,dtlb_fault

	L2_ptep		ptp,pte,t0,va,dtlb_check_alias_11

	tlb_lock	spc,ptp,pte,t0,t1,dtlb_check_alias_11
	update_accessed	ptp,pte,t0,t1

	make_insert_tlb_11	spc,pte,prot

	mfsp		%sr1,t1  /* Save sr1 so we can use it in tlb inserts */
	mtsp		spc,%sr1

	idtlba		pte,(%sr1,va)
	idtlbp		prot,(%sr1,va)

	mtsp		t1, %sr1	/* Restore sr1 */

	tlb_unlock1	spc,t0,t1
	rfir
	nop

dtlb_check_alias_11:
	do_alias	spc,t0,t1,va,pte,prot,dtlb_fault,11

	idtlba          pte,(va)
	idtlbp          prot,(va)

	rfir
	nop

nadtlb_miss_11:
	get_pgd		spc,ptp

	space_check	spc,t0,nadtlb_fault

	L2_ptep		ptp,pte,t0,va,nadtlb_check_alias_11

	tlb_lock	spc,ptp,pte,t0,t1,nadtlb_check_alias_11
	update_accessed	ptp,pte,t0,t1

	make_insert_tlb_11	spc,pte,prot

	mfsp		%sr1,t1  /* Save sr1 so we can use it in tlb inserts */
	mtsp		spc,%sr1

	idtlba		pte,(%sr1,va)
	idtlbp		prot,(%sr1,va)

	mtsp		t1, %sr1	/* Restore sr1 */

	tlb_unlock1	spc,t0,t1
	rfir
	nop

nadtlb_check_alias_11:
	do_alias	spc,t0,t1,va,pte,prot,nadtlb_emulate,11

	idtlba          pte,(va)
	idtlbp          prot,(va)

	rfir
	nop

dtlb_miss_20:
	space_adjust	spc,va,t0
	get_pgd		spc,ptp
	space_check	spc,t0,dtlb_fault

	L2_ptep		ptp,pte,t0,va,dtlb_check_alias_20

	tlb_lock	spc,ptp,pte,t0,t1,dtlb_check_alias_20
	update_accessed	ptp,pte,t0,t1

	make_insert_tlb	spc,pte,prot,t1

	f_extend	pte,t1

	idtlbt          pte,prot

	tlb_unlock1	spc,t0,t1
	rfir
	nop

dtlb_check_alias_20:
	do_alias	spc,t0,t1,va,pte,prot,dtlb_fault,20
	
	idtlbt          pte,prot

	rfir
	nop

nadtlb_miss_20:
	get_pgd		spc,ptp

	space_check	spc,t0,nadtlb_fault

	L2_ptep		ptp,pte,t0,va,nadtlb_check_alias_20

	tlb_lock	spc,ptp,pte,t0,t1,nadtlb_check_alias_20
	update_accessed	ptp,pte,t0,t1

	make_insert_tlb	spc,pte,prot,t1

	f_extend	pte,t1
	
	idtlbt		pte,prot

	tlb_unlock1	spc,t0,t1
	rfir
	nop

nadtlb_check_alias_20:
	do_alias	spc,t0,t1,va,pte,prot,nadtlb_emulate,20

	idtlbt          pte,prot

	rfir
	nop

#endif

nadtlb_emulate:

	/*
	 * Non access misses can be caused by fdc,fic,pdc,lpa,probe and
	 * probei instructions. We don't want to fault for these
	 * instructions (not only does it not make sense, it can cause
	 * deadlocks, since some flushes are done with the mmap
	 * semaphore held). If the translation doesn't exist, we can't
	 * insert a translation, so have to emulate the side effects
	 * of the instruction. Since we don't insert a translation
	 * we can get a lot of faults during a flush loop, so it makes
	 * sense to try to do it here with minimum overhead. We only
	 * emulate fdc,fic,pdc,probew,prober instructions whose base 
	 * and index registers are not shadowed. We defer everything 
	 * else to the "slow" path.
	 */

	mfctl           %cr19,%r9 /* Get iir */

	/* PA 2.0 Arch Ref. Book pg 382 has a good description of the insn bits.
	   Checks for fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw */

	/* Checks for fdc,fdce,pdc,"fic,4f" only */
	ldi             0x280,%r16
	and             %r9,%r16,%r17
	cmpb,<>,n       %r16,%r17,nadtlb_probe_check
	bb,>=,n         %r9,26,nadtlb_nullify  /* m bit not set, just nullify */
	BL		get_register,%r25
	extrw,u         %r9,15,5,%r8           /* Get index register # */
	cmpib,COND(=),n        -1,%r1,nadtlb_fault    /* have to use slow path */
	copy            %r1,%r24
	BL		get_register,%r25
	extrw,u         %r9,10,5,%r8           /* Get base register # */
	cmpib,COND(=),n        -1,%r1,nadtlb_fault    /* have to use slow path */
	BL		set_register,%r25
	add,l           %r1,%r24,%r1           /* doesn't affect c/b bits */

nadtlb_nullify:
	mfctl           %ipsw,%r8
	ldil            L%PSW_N,%r9
	or              %r8,%r9,%r8            /* Set PSW_N */
	mtctl           %r8,%ipsw

	rfir
	nop

	/* 
		When there is no translation for the probe address then we
		must nullify the insn and return zero in the target register.
		This will indicate to the calling code that it does not have 
		write/read privileges to this address.

		This should technically work for prober and probew in PA 1.1,
		and also probe,r and probe,w in PA 2.0

		WARNING: USE ONLY NON-SHADOW REGISTERS WITH PROBE INSN!
		THE SLOW-PATH EMULATION HAS NOT BEEN WRITTEN YET.

	*/
nadtlb_probe_check:
	ldi             0x80,%r16
	and             %r9,%r16,%r17
	cmpb,<>,n       %r16,%r17,nadtlb_fault /* Must be probe,[rw]*/
	BL              get_register,%r25      /* Find the target register */
	extrw,u         %r9,31,5,%r8           /* Get target register */
	cmpib,COND(=),n        -1,%r1,nadtlb_fault    /* have to use slow path */
	BL		set_register,%r25
	copy            %r0,%r1                /* Write zero to target register */
	b nadtlb_nullify                       /* Nullify return insn */
	nop


#ifdef CONFIG_64BIT
itlb_miss_20w:

	/*
	 * I miss is a little different, since we allow users to fault
	 * on the gateway page which is in the kernel address space.
	 */

	space_adjust	spc,va,t0
	get_pgd		spc,ptp
	space_check	spc,t0,itlb_fault

	L3_ptep		ptp,pte,t0,va,itlb_fault

	tlb_lock	spc,ptp,pte,t0,t1,itlb_fault
	update_accessed	ptp,pte,t0,t1

	make_insert_tlb	spc,pte,prot,t1
	
	iitlbt          pte,prot

	tlb_unlock1	spc,t0,t1
	rfir
	nop

naitlb_miss_20w:

	/*
	 * I miss is a little different, since we allow users to fault
	 * on the gateway page which is in the kernel address space.
	 */

	space_adjust	spc,va,t0
	get_pgd		spc,ptp
	space_check	spc,t0,naitlb_fault

	L3_ptep		ptp,pte,t0,va,naitlb_check_alias_20w

	tlb_lock	spc,ptp,pte,t0,t1,naitlb_check_alias_20w
	update_accessed	ptp,pte,t0,t1

	make_insert_tlb	spc,pte,prot,t1

	iitlbt          pte,prot

	tlb_unlock1	spc,t0,t1
	rfir
	nop

naitlb_check_alias_20w:
	do_alias	spc,t0,t1,va,pte,prot,naitlb_fault,20

	iitlbt		pte,prot

	rfir
	nop

#else

itlb_miss_11:
	get_pgd		spc,ptp

	space_check	spc,t0,itlb_fault

	L2_ptep		ptp,pte,t0,va,itlb_fault

	tlb_lock	spc,ptp,pte,t0,t1,itlb_fault
	update_accessed	ptp,pte,t0,t1

	make_insert_tlb_11	spc,pte,prot

	mfsp		%sr1,t1  /* Save sr1 so we can use it in tlb inserts */
	mtsp		spc,%sr1

	iitlba		pte,(%sr1,va)
	iitlbp		prot,(%sr1,va)

	mtsp		t1, %sr1	/* Restore sr1 */

	tlb_unlock1	spc,t0,t1
	rfir
	nop

naitlb_miss_11:
	get_pgd		spc,ptp

	space_check	spc,t0,naitlb_fault

	L2_ptep		ptp,pte,t0,va,naitlb_check_alias_11

	tlb_lock	spc,ptp,pte,t0,t1,naitlb_check_alias_11
	update_accessed	ptp,pte,t0,t1

	make_insert_tlb_11	spc,pte,prot

	mfsp		%sr1,t1  /* Save sr1 so we can use it in tlb inserts */
	mtsp		spc,%sr1

	iitlba		pte,(%sr1,va)
	iitlbp		prot,(%sr1,va)

	mtsp		t1, %sr1	/* Restore sr1 */

	tlb_unlock1	spc,t0,t1
	rfir
	nop

naitlb_check_alias_11:
	do_alias	spc,t0,t1,va,pte,prot,itlb_fault,11

	iitlba          pte,(%sr0, va)
	iitlbp          prot,(%sr0, va)

	rfir
	nop


itlb_miss_20:
	get_pgd		spc,ptp

	space_check	spc,t0,itlb_fault

	L2_ptep		ptp,pte,t0,va,itlb_fault

	tlb_lock	spc,ptp,pte,t0,t1,itlb_fault
	update_accessed	ptp,pte,t0,t1

	make_insert_tlb	spc,pte,prot,t1

	f_extend	pte,t1

	iitlbt          pte,prot

	tlb_unlock1	spc,t0,t1
	rfir
	nop

naitlb_miss_20:
	get_pgd		spc,ptp

	space_check	spc,t0,naitlb_fault

	L2_ptep		ptp,pte,t0,va,naitlb_check_alias_20

	tlb_lock	spc,ptp,pte,t0,t1,naitlb_check_alias_20
	update_accessed	ptp,pte,t0,t1

	make_insert_tlb	spc,pte,prot,t1

	f_extend	pte,t1

	iitlbt          pte,prot

	tlb_unlock1	spc,t0,t1
	rfir
	nop

naitlb_check_alias_20:
	do_alias	spc,t0,t1,va,pte,prot,naitlb_fault,20

	iitlbt          pte,prot

	rfir
	nop

#endif

#ifdef CONFIG_64BIT

dbit_trap_20w:
	space_adjust	spc,va,t0
	get_pgd		spc,ptp
	space_check	spc,t0,dbit_fault

	L3_ptep		ptp,pte,t0,va,dbit_fault

	tlb_lock	spc,ptp,pte,t0,t1,dbit_fault
	update_dirty	ptp,pte,t1

	make_insert_tlb	spc,pte,prot,t1
		
	idtlbt          pte,prot

	tlb_unlock0	spc,t0,t1
	rfir
	nop
#else

dbit_trap_11:

	get_pgd		spc,ptp

	space_check	spc,t0,dbit_fault

	L2_ptep		ptp,pte,t0,va,dbit_fault

	tlb_lock	spc,ptp,pte,t0,t1,dbit_fault
	update_dirty	ptp,pte,t1

	make_insert_tlb_11	spc,pte,prot

	mfsp            %sr1,t1  /* Save sr1 so we can use it in tlb inserts */
	mtsp		spc,%sr1

	idtlba		pte,(%sr1,va)
	idtlbp		prot,(%sr1,va)

	mtsp            t1, %sr1     /* Restore sr1 */

	tlb_unlock0	spc,t0,t1
	rfir
	nop

dbit_trap_20:
	get_pgd		spc,ptp

	space_check	spc,t0,dbit_fault

	L2_ptep		ptp,pte,t0,va,dbit_fault

	tlb_lock	spc,ptp,pte,t0,t1,dbit_fault
	update_dirty	ptp,pte,t1

	make_insert_tlb	spc,pte,prot,t1

	f_extend	pte,t1
	
	idtlbt		pte,prot

	tlb_unlock0	spc,t0,t1
	rfir
	nop
#endif

	.import handle_interruption,code

kernel_bad_space:
	b               intr_save
	ldi             31,%r8  /* Use an unused code */

dbit_fault:
	b               intr_save
	ldi             20,%r8

itlb_fault:
	b               intr_save
	ldi             PARISC_ITLB_TRAP,%r8

nadtlb_fault:
	b               intr_save
	ldi             17,%r8

naitlb_fault:
	b               intr_save
	ldi             16,%r8

dtlb_fault:
	b               intr_save
	ldi             15,%r8

	/* Register saving semantics for system calls:

	   %r1		   clobbered by system call macro in userspace
	   %r2		   saved in PT_REGS by gateway page
	   %r3  - %r18	   preserved by C code (saved by signal code)
	   %r19 - %r20	   saved in PT_REGS by gateway page
	   %r21 - %r22	   non-standard syscall args
			   stored in kernel stack by gateway page
	   %r23 - %r26	   arg3-arg0, saved in PT_REGS by gateway page
	   %r27 - %r30	   saved in PT_REGS by gateway page
	   %r31		   syscall return pointer
	 */

	/* Floating point registers (FIXME: what do we do with these?)

	   %fr0  - %fr3	   status/exception, not preserved
	   %fr4  - %fr7	   arguments
	   %fr8	 - %fr11   not preserved by C code
	   %fr12 - %fr21   preserved by C code
	   %fr22 - %fr31   not preserved by C code
	 */

	.macro	reg_save regs
	STREG	%r3, PT_GR3(\regs)
	STREG	%r4, PT_GR4(\regs)
	STREG	%r5, PT_GR5(\regs)
	STREG	%r6, PT_GR6(\regs)
	STREG	%r7, PT_GR7(\regs)
	STREG	%r8, PT_GR8(\regs)
	STREG	%r9, PT_GR9(\regs)
	STREG   %r10,PT_GR10(\regs)
	STREG   %r11,PT_GR11(\regs)
	STREG   %r12,PT_GR12(\regs)
	STREG   %r13,PT_GR13(\regs)
	STREG   %r14,PT_GR14(\regs)
	STREG   %r15,PT_GR15(\regs)
	STREG   %r16,PT_GR16(\regs)
	STREG   %r17,PT_GR17(\regs)
	STREG   %r18,PT_GR18(\regs)
	.endm

	.macro	reg_restore regs
	LDREG	PT_GR3(\regs), %r3
	LDREG	PT_GR4(\regs), %r4
	LDREG	PT_GR5(\regs), %r5
	LDREG	PT_GR6(\regs), %r6
	LDREG	PT_GR7(\regs), %r7
	LDREG	PT_GR8(\regs), %r8
	LDREG	PT_GR9(\regs), %r9
	LDREG   PT_GR10(\regs),%r10
	LDREG   PT_GR11(\regs),%r11
	LDREG   PT_GR12(\regs),%r12
	LDREG   PT_GR13(\regs),%r13
	LDREG   PT_GR14(\regs),%r14
	LDREG   PT_GR15(\regs),%r15
	LDREG   PT_GR16(\regs),%r16
	LDREG   PT_GR17(\regs),%r17
	LDREG   PT_GR18(\regs),%r18
	.endm

	.macro	fork_like name
ENTRY_CFI(sys_\name\()_wrapper)
	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1
	ldo	TASK_REGS(%r1),%r1
	reg_save %r1
	mfctl	%cr27, %r28
	ldil	L%sys_\name, %r31
	be	R%sys_\name(%sr4,%r31)
	STREG	%r28, PT_CR27(%r1)
ENDPROC_CFI(sys_\name\()_wrapper)
	.endm

fork_like clone
fork_like clone3
fork_like fork
fork_like vfork

	/* Set the return value for the child */
ENTRY(child_return)
	BL	schedule_tail, %r2
	nop
finish_child_return:
	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1
	ldo	TASK_REGS(%r1),%r1	 /* get pt regs */

	LDREG	PT_CR27(%r1), %r3
	mtctl	%r3, %cr27
	reg_restore %r1
	b	syscall_exit
	copy	%r0,%r28
END(child_return)

ENTRY_CFI(sys_rt_sigreturn_wrapper)
	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r26
	ldo	TASK_REGS(%r26),%r26	/* get pt regs */
	/* Don't save regs, we are going to restore them from sigcontext. */
	STREG	%r2, -RP_OFFSET(%r30)
#ifdef CONFIG_64BIT
	ldo	FRAME_SIZE(%r30), %r30
	BL	sys_rt_sigreturn,%r2
	ldo	-16(%r30),%r29		/* Reference param save area */
#else
	BL	sys_rt_sigreturn,%r2
	ldo	FRAME_SIZE(%r30), %r30
#endif

	ldo	-FRAME_SIZE(%r30), %r30
	LDREG	-RP_OFFSET(%r30), %r2

	/* FIXME: I think we need to restore a few more things here. */
	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
	ldo	TASK_REGS(%r1),%r1	/* get pt regs */
	reg_restore %r1

	/* If the signal was received while the process was blocked on a
	 * syscall, then r2 will take us to syscall_exit; otherwise r2 will
	 * take us to syscall_exit_rfi and on to intr_return.
	 */
	bv	%r0(%r2)
	LDREG	PT_GR28(%r1),%r28  /* reload original r28 for syscall_exit */
ENDPROC_CFI(sys_rt_sigreturn_wrapper)

ENTRY(syscall_exit)
	/* NOTE: Not all syscalls exit this way.  rt_sigreturn will exit
	 * via syscall_exit_rfi if the signal was received while the process
	 * was running.
	 */

	/* save return value now */

	mfctl     %cr30, %r1
	LDREG     TI_TASK(%r1),%r1
	STREG     %r28,TASK_PT_GR28(%r1)

	/* Seems to me that dp could be wrong here, if the syscall involved
	 * calling a module, and nothing got round to restoring dp on return.
	 */
	loadgp

syscall_check_resched:

	/* check for reschedule */

	LDREG	TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19	/* long */
	bb,<,n	%r19, 31-TIF_NEED_RESCHED, syscall_do_resched /* forward */

	.import do_signal,code
syscall_check_sig:
	LDREG	TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19
	ldi	(_TIF_SIGPENDING|_TIF_NOTIFY_RESUME), %r26
	and,COND(<>)	%r19, %r26, %r0
	b,n	syscall_restore	/* skip past if we've nothing to do */

syscall_do_signal:
	/* Save callee-save registers (for sigcontext).
	 * FIXME: After this point the process structure should be
	 * consistent with all the relevant state of the process
	 * before the syscall.  We need to verify this.
	 */
	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
	ldo	TASK_REGS(%r1), %r26		/* struct pt_regs *regs */
	reg_save %r26

#ifdef CONFIG_64BIT
	ldo	-16(%r30),%r29			/* Reference param save area */
#endif

	BL	do_notify_resume,%r2
	ldi	1, %r25				/* long in_syscall = 1 */

	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
	ldo	TASK_REGS(%r1), %r20		/* reload pt_regs */
	reg_restore %r20

	b,n     syscall_check_sig

syscall_restore:
	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1

	/* Are we being ptraced? */
	ldw	TASK_FLAGS(%r1),%r19
	ldi	_TIF_SYSCALL_TRACE_MASK,%r2
	and,COND(=)	%r19,%r2,%r0
	b,n	syscall_restore_rfi

	ldo	TASK_PT_FR31(%r1),%r19		   /* reload fpregs */
	rest_fp	%r19

	LDREG	TASK_PT_SAR(%r1),%r19		   /* restore SAR */
	mtsar	%r19

	LDREG	TASK_PT_GR2(%r1),%r2		   /* restore user rp */
	LDREG	TASK_PT_GR19(%r1),%r19
	LDREG   TASK_PT_GR20(%r1),%r20
	LDREG	TASK_PT_GR21(%r1),%r21
	LDREG	TASK_PT_GR22(%r1),%r22
	LDREG	TASK_PT_GR23(%r1),%r23
	LDREG	TASK_PT_GR24(%r1),%r24
	LDREG	TASK_PT_GR25(%r1),%r25
	LDREG	TASK_PT_GR26(%r1),%r26
	LDREG	TASK_PT_GR27(%r1),%r27	   /* restore user dp */
	LDREG	TASK_PT_GR28(%r1),%r28	   /* syscall return value */
	LDREG	TASK_PT_GR29(%r1),%r29
	LDREG	TASK_PT_GR31(%r1),%r31	   /* restore syscall rp */

	/* NOTE: We use rsm/ssm pair to make this operation atomic */
	LDREG   TASK_PT_GR30(%r1),%r1              /* Get user sp */
	rsm     PSW_SM_I, %r0
	copy    %r1,%r30                           /* Restore user sp */
	mfsp    %sr3,%r1                           /* Get user space id */
	mtsp    %r1,%sr7                           /* Restore sr7 */
	ssm     PSW_SM_I, %r0

	/* Set sr2 to zero for userspace syscalls to work. */
	mtsp	%r0,%sr2 
	mtsp	%r1,%sr4			   /* Restore sr4 */
	mtsp	%r1,%sr5			   /* Restore sr5 */
	mtsp	%r1,%sr6			   /* Restore sr6 */

	depi	3,31,2,%r31			   /* ensure return to user mode. */

#ifdef CONFIG_64BIT
	/* decide whether to reset the wide mode bit
	 *
	 * For a syscall, the W bit is stored in the lowest bit
	 * of sp.  Extract it and reset W if it is zero */
	extrd,u,*<>	%r30,63,1,%r1
	rsm	PSW_SM_W, %r0
	/* now reset the lowest bit of sp if it was set */
	xor	%r30,%r1,%r30
#endif
	be,n    0(%sr3,%r31)                       /* return to user space */

	/* We have to return via an RFI, so that PSW T and R bits can be set
	 * appropriately.
	 * This sets up pt_regs so we can return via intr_restore, which is not
	 * the most efficient way of doing things, but it works.
	 */
syscall_restore_rfi:
	ldo	-1(%r0),%r2			   /* Set recovery cntr to -1 */
	mtctl	%r2,%cr0			   /*   for immediate trap */
	LDREG	TASK_PT_PSW(%r1),%r2		   /* Get old PSW */
	ldi	0x0b,%r20			   /* Create new PSW */
	depi	-1,13,1,%r20			   /* C, Q, D, and I bits */

	/* The values of SINGLESTEP_BIT and BLOCKSTEP_BIT are
	 * set in thread_info.h and converted to PA bitmap
	 * numbers in asm-offsets.c */

	/* if ((%r19.SINGLESTEP_BIT)) { %r20.27=1} */
	extru,=	%r19,TIF_SINGLESTEP_PA_BIT,1,%r0
	depi	-1,27,1,%r20			   /* R bit */

	/* if ((%r19.BLOCKSTEP_BIT)) { %r20.7=1} */
	extru,= %r19,TIF_BLOCKSTEP_PA_BIT,1,%r0
	depi	-1,7,1,%r20			   /* T bit */

	STREG	%r20,TASK_PT_PSW(%r1)

	/* Always store space registers, since sr3 can be changed (e.g. fork) */

	mfsp    %sr3,%r25
	STREG   %r25,TASK_PT_SR3(%r1)
	STREG   %r25,TASK_PT_SR4(%r1)
	STREG   %r25,TASK_PT_SR5(%r1)
	STREG   %r25,TASK_PT_SR6(%r1)
	STREG   %r25,TASK_PT_SR7(%r1)
	STREG   %r25,TASK_PT_IASQ0(%r1)
	STREG   %r25,TASK_PT_IASQ1(%r1)

	/* XXX W bit??? */
	/* Now if old D bit is clear, it means we didn't save all registers
	 * on syscall entry, so do that now.  This only happens on TRACEME
	 * calls, or if someone attached to us while we were on a syscall.
	 * We could make this more efficient by not saving r3-r18, but
	 * then we wouldn't be able to use the common intr_restore path.
	 * It is only for traced processes anyway, so performance is not
	 * an issue.
	 */
	bb,<	%r2,30,pt_regs_ok		   /* Branch if D set */
	ldo	TASK_REGS(%r1),%r25
	reg_save %r25				   /* Save r3 to r18 */

	/* Save the current sr */
	mfsp	%sr0,%r2
	STREG	%r2,TASK_PT_SR0(%r1)

	/* Save the scratch sr */
	mfsp	%sr1,%r2
	STREG	%r2,TASK_PT_SR1(%r1)

	/* sr2 should be set to zero for userspace syscalls */
	STREG	%r0,TASK_PT_SR2(%r1)

	LDREG	TASK_PT_GR31(%r1),%r2
	depi	3,31,2,%r2		   /* ensure return to user mode. */
	STREG   %r2,TASK_PT_IAOQ0(%r1)
	ldo	4(%r2),%r2
	STREG	%r2,TASK_PT_IAOQ1(%r1)
	b	intr_restore
	copy	%r25,%r16

pt_regs_ok:
	LDREG	TASK_PT_IAOQ0(%r1),%r2
	depi	3,31,2,%r2		   /* ensure return to user mode. */
	STREG	%r2,TASK_PT_IAOQ0(%r1)
	LDREG	TASK_PT_IAOQ1(%r1),%r2
	depi	3,31,2,%r2
	STREG	%r2,TASK_PT_IAOQ1(%r1)
	b	intr_restore
	copy	%r25,%r16

syscall_do_resched:
	load32	syscall_check_resched,%r2 /* if resched, we start over again */
	load32	schedule,%r19
	bv	%r0(%r19)		/* jumps to schedule() */
#ifdef CONFIG_64BIT
	ldo	-16(%r30),%r29		/* Reference param save area */
#else
	nop
#endif
END(syscall_exit)


#ifdef CONFIG_FUNCTION_TRACER

	.import ftrace_function_trampoline,code
	.align L1_CACHE_BYTES
ENTRY_CFI(mcount, caller)
_mcount:
	.export _mcount,data
	/*
	 * The 64bit mcount() function pointer needs 4 dwords, of which the
	 * first two are free.  We optimize it here and put 2 instructions for
	 * calling mcount(), and 2 instructions for ftrace_stub().  That way we
	 * have all on one L1 cacheline.
	 */
	b	ftrace_function_trampoline
	copy	%r3, %arg2	/* caller original %sp */
ftrace_stub:
	.globl ftrace_stub
        .type  ftrace_stub, @function
#ifdef CONFIG_64BIT
	bve	(%rp)
#else
	bv	%r0(%rp)
#endif
	nop
#ifdef CONFIG_64BIT
	.dword mcount
	.dword 0 /* code in head.S puts value of global gp here */
#endif
ENDPROC_CFI(mcount)

#ifdef CONFIG_DYNAMIC_FTRACE

#ifdef CONFIG_64BIT
#define FTRACE_FRAME_SIZE (2*FRAME_SIZE)
#else
#define FTRACE_FRAME_SIZE FRAME_SIZE
#endif
ENTRY_CFI(ftrace_caller, caller,frame=FTRACE_FRAME_SIZE,CALLS,SAVE_RP,SAVE_SP)
ftrace_caller:
	.global ftrace_caller

	STREG	%r3, -FTRACE_FRAME_SIZE+1*REG_SZ(%sp)
	ldo	-FTRACE_FRAME_SIZE(%sp), %r3
	STREG	%rp, -RP_OFFSET(%r3)

	/* Offset 0 is already allocated for %r1 */
	STREG	%r23, 2*REG_SZ(%r3)
	STREG	%r24, 3*REG_SZ(%r3)
	STREG	%r25, 4*REG_SZ(%r3)
	STREG	%r26, 5*REG_SZ(%r3)
	STREG	%r28, 6*REG_SZ(%r3)
	STREG	%r29, 7*REG_SZ(%r3)
#ifdef CONFIG_64BIT
	STREG	%r19, 8*REG_SZ(%r3)
	STREG	%r20, 9*REG_SZ(%r3)
	STREG	%r21, 10*REG_SZ(%r3)
	STREG	%r22, 11*REG_SZ(%r3)
	STREG	%r27, 12*REG_SZ(%r3)
	STREG	%r31, 13*REG_SZ(%r3)
	loadgp
	ldo	-16(%sp),%r29
#endif
	LDREG	0(%r3), %r25
	copy	%rp, %r26
	ldo	-8(%r25), %r25
	b,l	ftrace_function_trampoline, %rp
	copy	%r3, %r24

	LDREG	-RP_OFFSET(%r3), %rp
	LDREG	2*REG_SZ(%r3), %r23
	LDREG	3*REG_SZ(%r3), %r24
	LDREG	4*REG_SZ(%r3), %r25
	LDREG	5*REG_SZ(%r3), %r26
	LDREG	6*REG_SZ(%r3), %r28
	LDREG	7*REG_SZ(%r3), %r29
#ifdef CONFIG_64BIT
	LDREG	8*REG_SZ(%r3), %r19
	LDREG	9*REG_SZ(%r3), %r20
	LDREG	10*REG_SZ(%r3), %r21
	LDREG	11*REG_SZ(%r3), %r22
	LDREG	12*REG_SZ(%r3), %r27
	LDREG	13*REG_SZ(%r3), %r31
#endif
	LDREG	1*REG_SZ(%r3), %r3

	LDREGM	-FTRACE_FRAME_SIZE(%sp), %r1
	/* Adjust return point to jump back to beginning of traced function */
	ldo	-4(%r1), %r1
	bv,n	(%r1)

ENDPROC_CFI(ftrace_caller)

#endif

#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	.align 8
ENTRY_CFI(return_to_handler, caller,frame=FRAME_SIZE)
	.export parisc_return_to_handler,data
parisc_return_to_handler:
	copy %r3,%r1
	STREG %r0,-RP_OFFSET(%sp)	/* store 0 as %rp */
	copy %sp,%r3
	STREGM %r1,FRAME_SIZE(%sp)
	STREG %ret0,8(%r3)
	STREG %ret1,16(%r3)

#ifdef CONFIG_64BIT
	loadgp
#endif

	/* call ftrace_return_to_handler(0) */
	.import ftrace_return_to_handler,code
	load32 ftrace_return_to_handler,%ret0
	load32 .Lftrace_ret,%r2
#ifdef CONFIG_64BIT
	ldo -16(%sp),%ret1		/* Reference param save area */
	bve	(%ret0)
#else
	bv	%r0(%ret0)
#endif
	ldi 0,%r26
.Lftrace_ret:
	copy %ret0,%rp

	/* restore original return values */
	LDREG 8(%r3),%ret0
	LDREG 16(%r3),%ret1

	/* return from function */
#ifdef CONFIG_64BIT
	bve	(%rp)
#else
	bv	%r0(%rp)
#endif
	LDREGM -FRAME_SIZE(%sp),%r3
ENDPROC_CFI(return_to_handler)

#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

#endif	/* CONFIG_FUNCTION_TRACER */

#ifdef CONFIG_IRQSTACKS
/* void call_on_stack(unsigned long param1, void *func,
		      unsigned long new_stack) */
ENTRY_CFI(call_on_stack, FRAME=2*FRAME_SIZE,CALLS,SAVE_RP,SAVE_SP)
ENTRY(_call_on_stack)
	copy	%sp, %r1

	/* Regarding the HPPA calling conventions for function pointers,
	   we assume the PIC register is not changed across call.  For
	   CONFIG_64BIT, the argument pointer is left to point at the
	   argument region allocated for the call to call_on_stack. */

	/* Switch to new stack.  We allocate two frames.  */
	ldo	2*FRAME_SIZE(%arg2), %sp
# ifdef CONFIG_64BIT
	/* Save previous stack pointer and return pointer in frame marker */
	STREG	%rp, -FRAME_SIZE-RP_OFFSET(%sp)
	/* Calls always use function descriptor */
	LDREG	16(%arg1), %arg1
	bve,l	(%arg1), %rp
	STREG	%r1, -FRAME_SIZE-REG_SZ(%sp)
	LDREG	-FRAME_SIZE-RP_OFFSET(%sp), %rp
	bve	(%rp)
	LDREG	-FRAME_SIZE-REG_SZ(%sp), %sp
# else
	/* Save previous stack pointer and return pointer in frame marker */
	STREG	%r1, -FRAME_SIZE-REG_SZ(%sp)
	STREG	%rp, -FRAME_SIZE-RP_OFFSET(%sp)
	/* Calls use function descriptor if PLABEL bit is set */
	bb,>=,n	%arg1, 30, 1f
	depwi	0,31,2, %arg1
	LDREG	0(%arg1), %arg1
1:
	be,l	0(%sr4,%arg1), %sr0, %r31
	copy	%r31, %rp
	LDREG	-FRAME_SIZE-RP_OFFSET(%sp), %rp
	bv	(%rp)
	LDREG	-FRAME_SIZE-REG_SZ(%sp), %sp
# endif /* CONFIG_64BIT */
ENDPROC_CFI(call_on_stack)
#endif /* CONFIG_IRQSTACKS */

ENTRY_CFI(get_register)
	/*
	 * get_register is used by the non access tlb miss handlers to
	 * copy the value of the general register specified in r8 into
	 * r1. This routine can't be used for shadowed registers, since
	 * the rfir will restore the original value. So, for the shadowed
	 * registers we put a -1 into r1 to indicate that the register
	 * should not be used (the register being copied could also have
	 * a -1 in it, but that is OK, it just means that we will have
	 * to use the slow path instead).
	 */
	blr     %r8,%r0
	nop
	bv      %r0(%r25)    /* r0 */
	copy    %r0,%r1
	bv      %r0(%r25)    /* r1 - shadowed */
	ldi     -1,%r1
	bv      %r0(%r25)    /* r2 */
	copy    %r2,%r1
	bv      %r0(%r25)    /* r3 */
	copy    %r3,%r1
	bv      %r0(%r25)    /* r4 */
	copy    %r4,%r1
	bv      %r0(%r25)    /* r5 */
	copy    %r5,%r1
	bv      %r0(%r25)    /* r6 */
	copy    %r6,%r1
	bv      %r0(%r25)    /* r7 */
	copy    %r7,%r1
	bv      %r0(%r25)    /* r8 - shadowed */
	ldi     -1,%r1
	bv      %r0(%r25)    /* r9 - shadowed */
	ldi     -1,%r1
	bv      %r0(%r25)    /* r10 */
	copy    %r10,%r1
	bv      %r0(%r25)    /* r11 */
	copy    %r11,%r1
	bv      %r0(%r25)    /* r12 */
	copy    %r12,%r1
	bv      %r0(%r25)    /* r13 */
	copy    %r13,%r1
	bv      %r0(%r25)    /* r14 */
	copy    %r14,%r1
	bv      %r0(%r25)    /* r15 */
	copy    %r15,%r1
	bv      %r0(%r25)    /* r16 - shadowed */
	ldi     -1,%r1
	bv      %r0(%r25)    /* r17 - shadowed */
	ldi     -1,%r1
	bv      %r0(%r25)    /* r18 */
	copy    %r18,%r1
	bv      %r0(%r25)    /* r19 */
	copy    %r19,%r1
	bv      %r0(%r25)    /* r20 */
	copy    %r20,%r1
	bv      %r0(%r25)    /* r21 */
	copy    %r21,%r1
	bv      %r0(%r25)    /* r22 */
	copy    %r22,%r1
	bv      %r0(%r25)    /* r23 */
	copy    %r23,%r1
	bv      %r0(%r25)    /* r24 - shadowed */
	ldi     -1,%r1
	bv      %r0(%r25)    /* r25 - shadowed */
	ldi     -1,%r1
	bv      %r0(%r25)    /* r26 */
	copy    %r26,%r1
	bv      %r0(%r25)    /* r27 */
	copy    %r27,%r1
	bv      %r0(%r25)    /* r28 */
	copy    %r28,%r1
	bv      %r0(%r25)    /* r29 */
	copy    %r29,%r1
	bv      %r0(%r25)    /* r30 */
	copy    %r30,%r1
	bv      %r0(%r25)    /* r31 */
	copy    %r31,%r1
ENDPROC_CFI(get_register)


ENTRY_CFI(set_register)
	/*
	 * set_register is used by the non access tlb miss handlers to
	 * copy the value of r1 into the general register specified in
	 * r8.
	 */
	blr     %r8,%r0
	nop
	bv      %r0(%r25)    /* r0 (silly, but it is a place holder) */
	copy    %r1,%r0
	bv      %r0(%r25)    /* r1 */
	copy    %r1,%r1
	bv      %r0(%r25)    /* r2 */
	copy    %r1,%r2
	bv      %r0(%r25)    /* r3 */
	copy    %r1,%r3
	bv      %r0(%r25)    /* r4 */
	copy    %r1,%r4
	bv      %r0(%r25)    /* r5 */
	copy    %r1,%r5
	bv      %r0(%r25)    /* r6 */
	copy    %r1,%r6
	bv      %r0(%r25)    /* r7 */
	copy    %r1,%r7
	bv      %r0(%r25)    /* r8 */
	copy    %r1,%r8
	bv      %r0(%r25)    /* r9 */
	copy    %r1,%r9
	bv      %r0(%r25)    /* r10 */
	copy    %r1,%r10
	bv      %r0(%r25)    /* r11 */
	copy    %r1,%r11
	bv      %r0(%r25)    /* r12 */
	copy    %r1,%r12
	bv      %r0(%r25)    /* r13 */
	copy    %r1,%r13
	bv      %r0(%r25)    /* r14 */
	copy    %r1,%r14
	bv      %r0(%r25)    /* r15 */
	copy    %r1,%r15
	bv      %r0(%r25)    /* r16 */
	copy    %r1,%r16
	bv      %r0(%r25)    /* r17 */
	copy    %r1,%r17
	bv      %r0(%r25)    /* r18 */
	copy    %r1,%r18
	bv      %r0(%r25)    /* r19 */
	copy    %r1,%r19
	bv      %r0(%r25)    /* r20 */
	copy    %r1,%r20
	bv      %r0(%r25)    /* r21 */
	copy    %r1,%r21
	bv      %r0(%r25)    /* r22 */
	copy    %r1,%r22
	bv      %r0(%r25)    /* r23 */
	copy    %r1,%r23
	bv      %r0(%r25)    /* r24 */
	copy    %r1,%r24
	bv      %r0(%r25)    /* r25 */
	copy    %r1,%r25
	bv      %r0(%r25)    /* r26 */
	copy    %r1,%r26
	bv      %r0(%r25)    /* r27 */
	copy    %r1,%r27
	bv      %r0(%r25)    /* r28 */
	copy    %r1,%r28
	bv      %r0(%r25)    /* r29 */
	copy    %r1,%r29
	bv      %r0(%r25)    /* r30 */
	copy    %r1,%r30
	bv      %r0(%r25)    /* r31 */
	copy    %r1,%r31
ENDPROC_CFI(set_register)