summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/oprofile/op_model_cell.c
blob: ae06c6236d9c396402040be44d25257283141abd (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
/*
 * Cell Broadband Engine OProfile Support
 *
 * (C) Copyright IBM Corporation 2006
 *
 * Author: David Erb (djerb@us.ibm.com)
 * Modifications:
 *	   Carl Love <carll@us.ibm.com>
 *	   Maynard Johnson <maynardj@us.ibm.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/cpufreq.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/kthread.h>
#include <linux/oprofile.h>
#include <linux/percpu.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <asm/cell-pmu.h>
#include <asm/cputable.h>
#include <asm/firmware.h>
#include <asm/io.h>
#include <asm/oprofile_impl.h>
#include <asm/processor.h>
#include <asm/prom.h>
#include <asm/ptrace.h>
#include <asm/reg.h>
#include <asm/rtas.h>
#include <asm/system.h>
#include <asm/cell-regs.h>

#include "../platforms/cell/interrupt.h"
#include "cell/pr_util.h"

#define PPU_PROFILING            0
#define SPU_PROFILING_CYCLES     1
#define SPU_PROFILING_EVENTS     2

#define SPU_EVENT_NUM_START      4100
#define SPU_EVENT_NUM_STOP       4399
#define SPU_PROFILE_EVENT_ADDR          4363  /* spu, address trace, decimal */
#define SPU_PROFILE_EVENT_ADDR_MASK_A   0x146 /* sub unit set to zero */
#define SPU_PROFILE_EVENT_ADDR_MASK_B   0x186 /* sub unit set to zero */

#define NUM_SPUS_PER_NODE    8
#define SPU_CYCLES_EVENT_NUM 2	/*  event number for SPU_CYCLES */

#define PPU_CYCLES_EVENT_NUM 1	/*  event number for CYCLES */
#define PPU_CYCLES_GRP_NUM   1	/* special group number for identifying
				 * PPU_CYCLES event
				 */
#define CBE_COUNT_ALL_CYCLES 0x42800000 /* PPU cycle event specifier */

#define NUM_THREADS 2         /* number of physical threads in
			       * physical processor
			       */
#define NUM_DEBUG_BUS_WORDS 4
#define NUM_INPUT_BUS_WORDS 2

#define MAX_SPU_COUNT 0xFFFFFF	/* maximum 24 bit LFSR value */

/* Minumum HW interval timer setting to send value to trace buffer is 10 cycle.
 * To configure counter to send value every N cycles set counter to
 * 2^32 - 1 - N.
 */
#define NUM_INTERVAL_CYC  0xFFFFFFFF - 10

/*
 * spu_cycle_reset is the number of cycles between samples.
 * This variable is used for SPU profiling and should ONLY be set
 * at the beginning of cell_reg_setup; otherwise, it's read-only.
 */
static unsigned int spu_cycle_reset;
static unsigned int profiling_mode;
static int spu_evnt_phys_spu_indx;

struct pmc_cntrl_data {
	unsigned long vcntr;
	unsigned long evnts;
	unsigned long masks;
	unsigned long enabled;
};

/*
 * ibm,cbe-perftools rtas parameters
 */
struct pm_signal {
	u16 cpu;		/* Processor to modify */
	u16 sub_unit;		/* hw subunit this applies to (if applicable)*/
	short int signal_group; /* Signal Group to Enable/Disable */
	u8 bus_word;		/* Enable/Disable on this Trace/Trigger/Event
				 * Bus Word(s) (bitmask)
				 */
	u8 bit;			/* Trigger/Event bit (if applicable) */
};

/*
 * rtas call arguments
 */
enum {
	SUBFUNC_RESET = 1,
	SUBFUNC_ACTIVATE = 2,
	SUBFUNC_DEACTIVATE = 3,

	PASSTHRU_IGNORE = 0,
	PASSTHRU_ENABLE = 1,
	PASSTHRU_DISABLE = 2,
};

struct pm_cntrl {
	u16 enable;
	u16 stop_at_max;
	u16 trace_mode;
	u16 freeze;
	u16 count_mode;
	u16 spu_addr_trace;
	u8  trace_buf_ovflw;
};

static struct {
	u32 group_control;
	u32 debug_bus_control;
	struct pm_cntrl pm_cntrl;
	u32 pm07_cntrl[NR_PHYS_CTRS];
} pm_regs;

#define GET_SUB_UNIT(x) ((x & 0x0000f000) >> 12)
#define GET_BUS_WORD(x) ((x & 0x000000f0) >> 4)
#define GET_BUS_TYPE(x) ((x & 0x00000300) >> 8)
#define GET_POLARITY(x) ((x & 0x00000002) >> 1)
#define GET_COUNT_CYCLES(x) (x & 0x00000001)
#define GET_INPUT_CONTROL(x) ((x & 0x00000004) >> 2)

static DEFINE_PER_CPU(unsigned long[NR_PHYS_CTRS], pmc_values);
static unsigned long spu_pm_cnt[MAX_NUMNODES * NUM_SPUS_PER_NODE];
static struct pmc_cntrl_data pmc_cntrl[NUM_THREADS][NR_PHYS_CTRS];

/*
 * The CELL profiling code makes rtas calls to setup the debug bus to
 * route the performance signals.  Additionally, SPU profiling requires
 * a second rtas call to setup the hardware to capture the SPU PCs.
 * The EIO error value is returned if the token lookups or the rtas
 * call fail.  The EIO error number is the best choice of the existing
 * error numbers.  The probability of rtas related error is very low.  But
 * by returning EIO and printing additional information to dmsg the user
 * will know that OProfile did not start and dmesg will tell them why.
 * OProfile does not support returning errors on Stop.	Not a huge issue
 * since failure to reset the debug bus or stop the SPU PC collection is
 * not a fatel issue.  Chances are if the Stop failed, Start doesn't work
 * either.
 */

/*
 * Interpetation of hdw_thread:
 * 0 - even virtual cpus 0, 2, 4,...
 * 1 - odd virtual cpus 1, 3, 5, ...
 *
 * FIXME: this is strictly wrong, we need to clean this up in a number
 * of places. It works for now. -arnd
 */
static u32 hdw_thread;

static u32 virt_cntr_inter_mask;
static struct timer_list timer_virt_cntr;
static struct timer_list timer_spu_event_swap;

/*
 * pm_signal needs to be global since it is initialized in
 * cell_reg_setup at the time when the necessary information
 * is available.
 */
static struct pm_signal pm_signal[NR_PHYS_CTRS];
static int pm_rtas_token;    /* token for debug bus setup call */
static int spu_rtas_token;   /* token for SPU cycle profiling */

static u32 reset_value[NR_PHYS_CTRS];
static int num_counters;
static int oprofile_running;
static DEFINE_SPINLOCK(cntr_lock);

static u32 ctr_enabled;

static unsigned char input_bus[NUM_INPUT_BUS_WORDS];

/*
 * Firmware interface functions
 */
static int
rtas_ibm_cbe_perftools(int subfunc, int passthru,
		       void *address, unsigned long length)
{
	u64 paddr = __pa(address);

	return rtas_call(pm_rtas_token, 5, 1, NULL, subfunc,
			 passthru, paddr >> 32, paddr & 0xffffffff, length);
}

static void pm_rtas_reset_signals(u32 node)
{
	int ret;
	struct pm_signal pm_signal_local;

	/*
	 * The debug bus is being set to the passthru disable state.
	 * However, the FW still expects atleast one legal signal routing
	 * entry or it will return an error on the arguments.	If we don't
	 * supply a valid entry, we must ignore all return values.  Ignoring
	 * all return values means we might miss an error we should be
	 * concerned about.
	 */

	/*  fw expects physical cpu #. */
	pm_signal_local.cpu = node;
	pm_signal_local.signal_group = 21;
	pm_signal_local.bus_word = 1;
	pm_signal_local.sub_unit = 0;
	pm_signal_local.bit = 0;

	ret = rtas_ibm_cbe_perftools(SUBFUNC_RESET, PASSTHRU_DISABLE,
				     &pm_signal_local,
				     sizeof(struct pm_signal));

	if (unlikely(ret))
		/*
		 * Not a fatal error. For Oprofile stop, the oprofile
		 * functions do not support returning an error for
		 * failure to stop OProfile.
		 */
		printk(KERN_WARNING "%s: rtas returned: %d\n",
		       __func__, ret);
}

static int pm_rtas_activate_signals(u32 node, u32 count)
{
	int ret;
	int i, j;
	struct pm_signal pm_signal_local[NR_PHYS_CTRS];

	/*
	 * There is no debug setup required for the cycles event.
	 * Note that only events in the same group can be used.
	 * Otherwise, there will be conflicts in correctly routing
	 * the signals on the debug bus.  It is the responsiblity
	 * of the OProfile user tool to check the events are in
	 * the same group.
	 */
	i = 0;
	for (j = 0; j < count; j++) {
		if (pm_signal[j].signal_group != PPU_CYCLES_GRP_NUM) {

			/* fw expects physical cpu # */
			pm_signal_local[i].cpu = node;
			pm_signal_local[i].signal_group
				= pm_signal[j].signal_group;
			pm_signal_local[i].bus_word = pm_signal[j].bus_word;
			pm_signal_local[i].sub_unit = pm_signal[j].sub_unit;
			pm_signal_local[i].bit = pm_signal[j].bit;
			i++;
		}
	}

	if (i != 0) {
		ret = rtas_ibm_cbe_perftools(SUBFUNC_ACTIVATE, PASSTHRU_ENABLE,
					     pm_signal_local,
					     i * sizeof(struct pm_signal));

		if (unlikely(ret)) {
			printk(KERN_WARNING "%s: rtas returned: %d\n",
			       __func__, ret);
			return -EIO;
		}
	}

	return 0;
}

/*
 * PM Signal functions
 */
static void set_pm_event(u32 ctr, int event, u32 unit_mask)
{
	struct pm_signal *p;
	u32 signal_bit;
	u32 bus_word, bus_type, count_cycles, polarity, input_control;
	int j, i;

	if (event == PPU_CYCLES_EVENT_NUM) {
		/* Special Event: Count all cpu cycles */
		pm_regs.pm07_cntrl[ctr] = CBE_COUNT_ALL_CYCLES;
		p = &(pm_signal[ctr]);
		p->signal_group = PPU_CYCLES_GRP_NUM;
		p->bus_word = 1;
		p->sub_unit = 0;
		p->bit = 0;
		goto out;
	} else {
		pm_regs.pm07_cntrl[ctr] = 0;
	}

	bus_word = GET_BUS_WORD(unit_mask);
	bus_type = GET_BUS_TYPE(unit_mask);
	count_cycles = GET_COUNT_CYCLES(unit_mask);
	polarity = GET_POLARITY(unit_mask);
	input_control = GET_INPUT_CONTROL(unit_mask);
	signal_bit = (event % 100);

	p = &(pm_signal[ctr]);

	p->signal_group = event / 100;
	p->bus_word = bus_word;
	p->sub_unit = GET_SUB_UNIT(unit_mask);

	pm_regs.pm07_cntrl[ctr] = 0;
	pm_regs.pm07_cntrl[ctr] |= PM07_CTR_COUNT_CYCLES(count_cycles);
	pm_regs.pm07_cntrl[ctr] |= PM07_CTR_POLARITY(polarity);
	pm_regs.pm07_cntrl[ctr] |= PM07_CTR_INPUT_CONTROL(input_control);

	/*
	 * Some of the islands signal selection is based on 64 bit words.
	 * The debug bus words are 32 bits, the input words to the performance
	 * counters are defined as 32 bits.  Need to convert the 64 bit island
	 * specification to the appropriate 32 input bit and bus word for the
	 * performance counter event selection.	 See the CELL Performance
	 * monitoring signals manual and the Perf cntr hardware descriptions
	 * for the details.
	 */
	if (input_control == 0) {
		if (signal_bit > 31) {
			signal_bit -= 32;
			if (bus_word == 0x3)
				bus_word = 0x2;
			else if (bus_word == 0xc)
				bus_word = 0x8;
		}

		if ((bus_type == 0) && p->signal_group >= 60)
			bus_type = 2;
		if ((bus_type == 1) && p->signal_group >= 50)
			bus_type = 0;

		pm_regs.pm07_cntrl[ctr] |= PM07_CTR_INPUT_MUX(signal_bit);
	} else {
		pm_regs.pm07_cntrl[ctr] = 0;
		p->bit = signal_bit;
	}

	for (i = 0; i < NUM_DEBUG_BUS_WORDS; i++) {
		if (bus_word & (1 << i)) {
			pm_regs.debug_bus_control |=
				(bus_type << (30 - (2 * i)));

			for (j = 0; j < NUM_INPUT_BUS_WORDS; j++) {
				if (input_bus[j] == 0xff) {
					input_bus[j] = i;
					pm_regs.group_control |=
						(i << (30 - (2 * j)));

					break;
				}
			}
		}
	}
out:
	;
}

static void write_pm_cntrl(int cpu)
{
	/*
	 * Oprofile will use 32 bit counters, set bits 7:10 to 0
	 * pmregs.pm_cntrl is a global
	 */

	u32 val = 0;
	if (pm_regs.pm_cntrl.enable == 1)
		val |= CBE_PM_ENABLE_PERF_MON;

	if (pm_regs.pm_cntrl.stop_at_max == 1)
		val |= CBE_PM_STOP_AT_MAX;

	if (pm_regs.pm_cntrl.trace_mode != 0)
		val |= CBE_PM_TRACE_MODE_SET(pm_regs.pm_cntrl.trace_mode);

	if (pm_regs.pm_cntrl.trace_buf_ovflw == 1)
		val |= CBE_PM_TRACE_BUF_OVFLW(pm_regs.pm_cntrl.trace_buf_ovflw);
	if (pm_regs.pm_cntrl.freeze == 1)
		val |= CBE_PM_FREEZE_ALL_CTRS;

	val |= CBE_PM_SPU_ADDR_TRACE_SET(pm_regs.pm_cntrl.spu_addr_trace);

	/*
	 * Routine set_count_mode must be called previously to set
	 * the count mode based on the user selection of user and kernel.
	 */
	val |= CBE_PM_COUNT_MODE_SET(pm_regs.pm_cntrl.count_mode);
	cbe_write_pm(cpu, pm_control, val);
}

static inline void
set_count_mode(u32 kernel, u32 user)
{
	/*
	 * The user must specify user and kernel if they want them. If
	 *  neither is specified, OProfile will count in hypervisor mode.
	 *  pm_regs.pm_cntrl is a global
	 */
	if (kernel) {
		if (user)
			pm_regs.pm_cntrl.count_mode = CBE_COUNT_ALL_MODES;
		else
			pm_regs.pm_cntrl.count_mode =
				CBE_COUNT_SUPERVISOR_MODE;
	} else {
		if (user)
			pm_regs.pm_cntrl.count_mode = CBE_COUNT_PROBLEM_MODE;
		else
			pm_regs.pm_cntrl.count_mode =
				CBE_COUNT_HYPERVISOR_MODE;
	}
}

static inline void enable_ctr(u32 cpu, u32 ctr, u32 *pm07_cntrl)
{

	pm07_cntrl[ctr] |= CBE_PM_CTR_ENABLE;
	cbe_write_pm07_control(cpu, ctr, pm07_cntrl[ctr]);
}

/*
 * Oprofile is expected to collect data on all CPUs simultaneously.
 * However, there is one set of performance counters per node.	There are
 * two hardware threads or virtual CPUs on each node.  Hence, OProfile must
 * multiplex in time the performance counter collection on the two virtual
 * CPUs.  The multiplexing of the performance counters is done by this
 * virtual counter routine.
 *
 * The pmc_values used below is defined as 'per-cpu' but its use is
 * more akin to 'per-node'.  We need to store two sets of counter
 * values per node -- one for the previous run and one for the next.
 * The per-cpu[NR_PHYS_CTRS] gives us the storage we need.  Each odd/even
 * pair of per-cpu arrays is used for storing the previous and next
 * pmc values for a given node.
 * NOTE: We use the per-cpu variable to improve cache performance.
 *
 * This routine will alternate loading the virtual counters for
 * virtual CPUs
 */
static void cell_virtual_cntr(unsigned long data)
{
	int i, prev_hdw_thread, next_hdw_thread;
	u32 cpu;
	unsigned long flags;

	/*
	 * Make sure that the interrupt_hander and the virt counter are
	 * not both playing with the counters on the same node.
	 */

	spin_lock_irqsave(&cntr_lock, flags);

	prev_hdw_thread = hdw_thread;

	/* switch the cpu handling the interrupts */
	hdw_thread = 1 ^ hdw_thread;
	next_hdw_thread = hdw_thread;

	pm_regs.group_control = 0;
	pm_regs.debug_bus_control = 0;

	for (i = 0; i < NUM_INPUT_BUS_WORDS; i++)
		input_bus[i] = 0xff;

	/*
	 * There are some per thread events.  Must do the
	 * set event, for the thread that is being started
	 */
	for (i = 0; i < num_counters; i++)
		set_pm_event(i,
			pmc_cntrl[next_hdw_thread][i].evnts,
			pmc_cntrl[next_hdw_thread][i].masks);

	/*
	 * The following is done only once per each node, but
	 * we need cpu #, not node #, to pass to the cbe_xxx functions.
	 */
	for_each_online_cpu(cpu) {
		if (cbe_get_hw_thread_id(cpu))
			continue;

		/*
		 * stop counters, save counter values, restore counts
		 * for previous thread
		 */
		cbe_disable_pm(cpu);
		cbe_disable_pm_interrupts(cpu);
		for (i = 0; i < num_counters; i++) {
			per_cpu(pmc_values, cpu + prev_hdw_thread)[i]
				= cbe_read_ctr(cpu, i);

			if (per_cpu(pmc_values, cpu + next_hdw_thread)[i]
			    == 0xFFFFFFFF)
				/* If the cntr value is 0xffffffff, we must
				 * reset that to 0xfffffff0 when the current
				 * thread is restarted.	 This will generate a
				 * new interrupt and make sure that we never
				 * restore the counters to the max value.  If
				 * the counters were restored to the max value,
				 * they do not increment and no interrupts are
				 * generated.  Hence no more samples will be
				 * collected on that cpu.
				 */
				cbe_write_ctr(cpu, i, 0xFFFFFFF0);
			else
				cbe_write_ctr(cpu, i,
					      per_cpu(pmc_values,
						      cpu +
						      next_hdw_thread)[i]);
		}

		/*
		 * Switch to the other thread. Change the interrupt
		 * and control regs to be scheduled on the CPU
		 * corresponding to the thread to execute.
		 */
		for (i = 0; i < num_counters; i++) {
			if (pmc_cntrl[next_hdw_thread][i].enabled) {
				/*
				 * There are some per thread events.
				 * Must do the set event, enable_cntr
				 * for each cpu.
				 */
				enable_ctr(cpu, i,
					   pm_regs.pm07_cntrl);
			} else {
				cbe_write_pm07_control(cpu, i, 0);
			}
		}

		/* Enable interrupts on the CPU thread that is starting */
		cbe_enable_pm_interrupts(cpu, next_hdw_thread,
					 virt_cntr_inter_mask);
		cbe_enable_pm(cpu);
	}

	spin_unlock_irqrestore(&cntr_lock, flags);

	mod_timer(&timer_virt_cntr, jiffies + HZ / 10);
}

static void start_virt_cntrs(void)
{
	init_timer(&timer_virt_cntr);
	timer_virt_cntr.function = cell_virtual_cntr;
	timer_virt_cntr.data = 0UL;
	timer_virt_cntr.expires = jiffies + HZ / 10;
	add_timer(&timer_virt_cntr);
}

static int cell_reg_setup_spu_cycles(struct op_counter_config *ctr,
			struct op_system_config *sys, int num_ctrs)
{
	spu_cycle_reset = ctr[0].count;

	/*
	 * Each node will need to make the rtas call to start
	 * and stop SPU profiling.  Get the token once and store it.
	 */
	spu_rtas_token = rtas_token("ibm,cbe-spu-perftools");

	if (unlikely(spu_rtas_token == RTAS_UNKNOWN_SERVICE)) {
		printk(KERN_ERR
		       "%s: rtas token ibm,cbe-spu-perftools unknown\n",
		       __func__);
		return -EIO;
	}
	return 0;
}

/* Unfortunately, the hardware will only support event profiling
 * on one SPU per node at a time.  Therefore, we must time slice
 * the profiling across all SPUs in the node.  Note, we do this
 * in parallel for each node.  The following routine is called
 * periodically based on kernel timer to switch which SPU is
 * being monitored in a round robbin fashion.
 */
static void spu_evnt_swap(unsigned long data)
{
	int node;
	int cur_phys_spu, nxt_phys_spu, cur_spu_evnt_phys_spu_indx;
	unsigned long flags;
	int cpu;
	int ret;
	u32 interrupt_mask;


	/* enable interrupts on cntr 0 */
	interrupt_mask = CBE_PM_CTR_OVERFLOW_INTR(0);

	hdw_thread = 0;

	/* Make sure spu event interrupt handler and spu event swap
	 * don't access the counters simultaneously.
	 */
	spin_lock_irqsave(&cntr_lock, flags);

	cur_spu_evnt_phys_spu_indx = spu_evnt_phys_spu_indx;

	if (++(spu_evnt_phys_spu_indx) == NUM_SPUS_PER_NODE)
		spu_evnt_phys_spu_indx = 0;

	pm_signal[0].sub_unit = spu_evnt_phys_spu_indx;
	pm_signal[1].sub_unit = spu_evnt_phys_spu_indx;
	pm_signal[2].sub_unit = spu_evnt_phys_spu_indx;

	/* switch the SPU being profiled on each node */
	for_each_online_cpu(cpu) {
		if (cbe_get_hw_thread_id(cpu))
			continue;

		node = cbe_cpu_to_node(cpu);
		cur_phys_spu = (node * NUM_SPUS_PER_NODE)
			+ cur_spu_evnt_phys_spu_indx;
		nxt_phys_spu = (node * NUM_SPUS_PER_NODE)
			+ spu_evnt_phys_spu_indx;

		/*
		 * stop counters, save counter values, restore counts
		 * for previous physical SPU
		 */
		cbe_disable_pm(cpu);
		cbe_disable_pm_interrupts(cpu);

		spu_pm_cnt[cur_phys_spu]
			= cbe_read_ctr(cpu, 0);

		/* restore previous count for the next spu to sample */
		/* NOTE, hardware issue, counter will not start if the
		 * counter value is at max (0xFFFFFFFF).
		 */
		if (spu_pm_cnt[nxt_phys_spu] >= 0xFFFFFFFF)
			cbe_write_ctr(cpu, 0, 0xFFFFFFF0);
		 else
			 cbe_write_ctr(cpu, 0, spu_pm_cnt[nxt_phys_spu]);

		pm_rtas_reset_signals(cbe_cpu_to_node(cpu));

		/* setup the debug bus measure the one event and
		 * the two events to route the next SPU's PC on
		 * the debug bus
		 */
		ret = pm_rtas_activate_signals(cbe_cpu_to_node(cpu), 3);
		if (ret)
			printk(KERN_ERR "%s: pm_rtas_activate_signals failed, "
			       "SPU event swap\n", __func__);

		/* clear the trace buffer, don't want to take PC for
		 * previous SPU*/
		cbe_write_pm(cpu, trace_address, 0);

		enable_ctr(cpu, 0, pm_regs.pm07_cntrl);

		/* Enable interrupts on the CPU thread that is starting */
		cbe_enable_pm_interrupts(cpu, hdw_thread,
					 interrupt_mask);
		cbe_enable_pm(cpu);
	}

	spin_unlock_irqrestore(&cntr_lock, flags);

	/* swap approximately every 0.1 seconds */
	mod_timer(&timer_spu_event_swap, jiffies + HZ / 25);
}

static void start_spu_event_swap(void)
{
	init_timer(&timer_spu_event_swap);
	timer_spu_event_swap.function = spu_evnt_swap;
	timer_spu_event_swap.data = 0UL;
	timer_spu_event_swap.expires = jiffies + HZ / 25;
	add_timer(&timer_spu_event_swap);
}

static int cell_reg_setup_spu_events(struct op_counter_config *ctr,
			struct op_system_config *sys, int num_ctrs)
{
	int i;

	/* routine is called once for all nodes */

	spu_evnt_phys_spu_indx = 0;
	/*
	 * For all events except PPU CYCLEs, each node will need to make
	 * the rtas cbe-perftools call to setup and reset the debug bus.
	 * Make the token lookup call once and store it in the global
	 * variable pm_rtas_token.
	 */
	pm_rtas_token = rtas_token("ibm,cbe-perftools");

	if (unlikely(pm_rtas_token == RTAS_UNKNOWN_SERVICE)) {
		printk(KERN_ERR
		       "%s: rtas token ibm,cbe-perftools unknown\n",
		       __func__);
		return -EIO;
	}

	/* setup the pm_control register settings,
	 * settings will be written per node by the
	 * cell_cpu_setup() function.
	 */
	pm_regs.pm_cntrl.trace_buf_ovflw = 1;

	/* Use the occurrence trace mode to have SPU PC saved
	 * to the trace buffer.  Occurrence data in trace buffer
	 * is not used.  Bit 2 must be set to store SPU addresses.
	 */
	pm_regs.pm_cntrl.trace_mode = 2;

	pm_regs.pm_cntrl.spu_addr_trace = 0x1;  /* using debug bus
						   event 2 & 3 */

	/* setup the debug bus event array with the SPU PC routing events.
	*  Note, pm_signal[0] will be filled in by set_pm_event() call below.
	*/
	pm_signal[1].signal_group = SPU_PROFILE_EVENT_ADDR / 100;
	pm_signal[1].bus_word = GET_BUS_WORD(SPU_PROFILE_EVENT_ADDR_MASK_A);
	pm_signal[1].bit = SPU_PROFILE_EVENT_ADDR % 100;
	pm_signal[1].sub_unit = spu_evnt_phys_spu_indx;

	pm_signal[2].signal_group = SPU_PROFILE_EVENT_ADDR / 100;
	pm_signal[2].bus_word = GET_BUS_WORD(SPU_PROFILE_EVENT_ADDR_MASK_B);
	pm_signal[2].bit = SPU_PROFILE_EVENT_ADDR % 100;
	pm_signal[2].sub_unit = spu_evnt_phys_spu_indx;

	/* Set the user selected spu event to profile on,
	 * note, only one SPU profiling event is supported
	 */
	num_counters = 1;  /* Only support one SPU event at a time */
	set_pm_event(0, ctr[0].event, ctr[0].unit_mask);

	reset_value[0] = 0xFFFFFFFF - ctr[0].count;

	/* global, used by cell_cpu_setup */
	ctr_enabled |= 1;

	/* Initialize the count for each SPU to the reset value */
	for (i=0; i < MAX_NUMNODES * NUM_SPUS_PER_NODE; i++)
		spu_pm_cnt[i] = reset_value[0];

	return 0;
}

static int cell_reg_setup_ppu(struct op_counter_config *ctr,
			struct op_system_config *sys, int num_ctrs)
{
	/* routine is called once for all nodes */
	int i, j, cpu;

	num_counters = num_ctrs;

	if (unlikely(num_ctrs > NR_PHYS_CTRS)) {
		printk(KERN_ERR
		       "%s: Oprofile, number of specified events " \
		       "exceeds number of physical counters\n",
		       __func__);
		return -EIO;
	}

	set_count_mode(sys->enable_kernel, sys->enable_user);

	/* Setup the thread 0 events */
	for (i = 0; i < num_ctrs; ++i) {

		pmc_cntrl[0][i].evnts = ctr[i].event;
		pmc_cntrl[0][i].masks = ctr[i].unit_mask;
		pmc_cntrl[0][i].enabled = ctr[i].enabled;
		pmc_cntrl[0][i].vcntr = i;

		for_each_possible_cpu(j)
			per_cpu(pmc_values, j)[i] = 0;
	}

	/*
	 * Setup the thread 1 events, map the thread 0 event to the
	 * equivalent thread 1 event.
	 */
	for (i = 0; i < num_ctrs; ++i) {
		if ((ctr[i].event >= 2100) && (ctr[i].event <= 2111))
			pmc_cntrl[1][i].evnts = ctr[i].event + 19;
		else if (ctr[i].event == 2203)
			pmc_cntrl[1][i].evnts = ctr[i].event;
		else if ((ctr[i].event >= 2200) && (ctr[i].event <= 2215))
			pmc_cntrl[1][i].evnts = ctr[i].event + 16;
		else
			pmc_cntrl[1][i].evnts = ctr[i].event;

		pmc_cntrl[1][i].masks = ctr[i].unit_mask;
		pmc_cntrl[1][i].enabled = ctr[i].enabled;
		pmc_cntrl[1][i].vcntr = i;
	}

	for (i = 0; i < NUM_INPUT_BUS_WORDS; i++)
		input_bus[i] = 0xff;

	/*
	 * Our counters count up, and "count" refers to
	 * how much before the next interrupt, and we interrupt
	 * on overflow.	 So we calculate the starting value
	 * which will give us "count" until overflow.
	 * Then we set the events on the enabled counters.
	 */
	for (i = 0; i < num_counters; ++i) {
		/* start with virtual counter set 0 */
		if (pmc_cntrl[0][i].enabled) {
			/* Using 32bit counters, reset max - count */
			reset_value[i] = 0xFFFFFFFF - ctr[i].count;
			set_pm_event(i,
				     pmc_cntrl[0][i].evnts,
				     pmc_cntrl[0][i].masks);

			/* global, used by cell_cpu_setup */
			ctr_enabled |= (1 << i);
		}
	}

	/* initialize the previous counts for the virtual cntrs */
	for_each_online_cpu(cpu)
		for (i = 0; i < num_counters; ++i) {
			per_cpu(pmc_values, cpu)[i] = reset_value[i];
		}

	return 0;
}


/* This function is called once for all cpus combined */
static int cell_reg_setup(struct op_counter_config *ctr,
			struct op_system_config *sys, int num_ctrs)
{
	int ret=0;
	spu_cycle_reset = 0;

	/* initialize the spu_arr_trace value, will be reset if
	 * doing spu event profiling.
	 */
	pm_regs.group_control = 0;
	pm_regs.debug_bus_control = 0;
	pm_regs.pm_cntrl.stop_at_max = 1;
	pm_regs.pm_cntrl.trace_mode = 0;
	pm_regs.pm_cntrl.freeze = 1;
	pm_regs.pm_cntrl.trace_buf_ovflw = 0;
	pm_regs.pm_cntrl.spu_addr_trace = 0;

	/*
	 * For all events except PPU CYCLEs, each node will need to make
	 * the rtas cbe-perftools call to setup and reset the debug bus.
	 * Make the token lookup call once and store it in the global
	 * variable pm_rtas_token.
	 */
	pm_rtas_token = rtas_token("ibm,cbe-perftools");

	if (unlikely(pm_rtas_token == RTAS_UNKNOWN_SERVICE)) {
		printk(KERN_ERR
		       "%s: rtas token ibm,cbe-perftools unknown\n",
		       __func__);
		return -EIO;
	}

	if (ctr[0].event == SPU_CYCLES_EVENT_NUM) {
		profiling_mode = SPU_PROFILING_CYCLES;
		ret = cell_reg_setup_spu_cycles(ctr, sys, num_ctrs);
	} else if ((ctr[0].event >= SPU_EVENT_NUM_START) &&
		   (ctr[0].event <= SPU_EVENT_NUM_STOP)) {
		profiling_mode = SPU_PROFILING_EVENTS;
		spu_cycle_reset = ctr[0].count;

		/* for SPU event profiling, need to setup the
		 * pm_signal array with the events to route the
		 * SPU PC before making the FW call.  Note, only
		 * one SPU event for profiling can be specified
		 * at a time.
		 */
		cell_reg_setup_spu_events(ctr, sys, num_ctrs);
	} else {
		profiling_mode = PPU_PROFILING;
		ret = cell_reg_setup_ppu(ctr, sys, num_ctrs);
	}

	return ret;
}



/* This function is called once for each cpu */
static int cell_cpu_setup(struct op_counter_config *cntr)
{
	u32 cpu = smp_processor_id();
	u32 num_enabled = 0;
	int i;
	int ret;

	/* Cycle based SPU profiling does not use the performance
	 * counters.  The trace array is configured to collect
	 * the data.
	 */
	if (profiling_mode == SPU_PROFILING_CYCLES)
		return 0;

	/* There is one performance monitor per processor chip (i.e. node),
	 * so we only need to perform this function once per node.
	 */
	if (cbe_get_hw_thread_id(cpu))
		return 0;

	/* Stop all counters */
	cbe_disable_pm(cpu);
	cbe_disable_pm_interrupts(cpu);

	cbe_write_pm(cpu, pm_start_stop, 0);
	cbe_write_pm(cpu, group_control, pm_regs.group_control);
	cbe_write_pm(cpu, debug_bus_control, pm_regs.debug_bus_control);
	write_pm_cntrl(cpu);

	for (i = 0; i < num_counters; ++i) {
		if (ctr_enabled & (1 << i)) {
			pm_signal[num_enabled].cpu = cbe_cpu_to_node(cpu);
			num_enabled++;
		}
	}

	/*
	 * The pm_rtas_activate_signals will return -EIO if the FW
	 * call failed.
	 */
	if (profiling_mode == SPU_PROFILING_EVENTS) {
		/* For SPU event profiling also need to setup the
		 * pm interval timer
		 */
		ret = pm_rtas_activate_signals(cbe_cpu_to_node(cpu),
					       num_enabled+2);
		/* store PC from debug bus to Trace buffer as often
		 * as possible (every 10 cycles)
		 */
		cbe_write_pm(cpu, pm_interval, NUM_INTERVAL_CYC);
		return ret;
	} else
		return pm_rtas_activate_signals(cbe_cpu_to_node(cpu),
						num_enabled);
}

#define ENTRIES	 303
#define MAXLFSR	 0xFFFFFF

/* precomputed table of 24 bit LFSR values */
static int initial_lfsr[] = {
 8221349, 12579195, 5379618, 10097839, 7512963, 7519310, 3955098, 10753424,
 15507573, 7458917, 285419, 2641121, 9780088, 3915503, 6668768, 1548716,
 4885000, 8774424, 9650099, 2044357, 2304411, 9326253, 10332526, 4421547,
 3440748, 10179459, 13332843, 10375561, 1313462, 8375100, 5198480, 6071392,
 9341783, 1526887, 3985002, 1439429, 13923762, 7010104, 11969769, 4547026,
 2040072, 4025602, 3437678, 7939992, 11444177, 4496094, 9803157, 10745556,
 3671780, 4257846, 5662259, 13196905, 3237343, 12077182, 16222879, 7587769,
 14706824, 2184640, 12591135, 10420257, 7406075, 3648978, 11042541, 15906893,
 11914928, 4732944, 10695697, 12928164, 11980531, 4430912, 11939291, 2917017,
 6119256, 4172004, 9373765, 8410071, 14788383, 5047459, 5474428, 1737756,
 15967514, 13351758, 6691285, 8034329, 2856544, 14394753, 11310160, 12149558,
 7487528, 7542781, 15668898, 12525138, 12790975, 3707933, 9106617, 1965401,
 16219109, 12801644, 2443203, 4909502, 8762329, 3120803, 6360315, 9309720,
 15164599, 10844842, 4456529, 6667610, 14924259, 884312, 6234963, 3326042,
 15973422, 13919464, 5272099, 6414643, 3909029, 2764324, 5237926, 4774955,
 10445906, 4955302, 5203726, 10798229, 11443419, 2303395, 333836, 9646934,
 3464726, 4159182, 568492, 995747, 10318756, 13299332, 4836017, 8237783,
 3878992, 2581665, 11394667, 5672745, 14412947, 3159169, 9094251, 16467278,
 8671392, 15230076, 4843545, 7009238, 15504095, 1494895, 9627886, 14485051,
 8304291, 252817, 12421642, 16085736, 4774072, 2456177, 4160695, 15409741,
 4902868, 5793091, 13162925, 16039714, 782255, 11347835, 14884586, 366972,
 16308990, 11913488, 13390465, 2958444, 10340278, 1177858, 1319431, 10426302,
 2868597, 126119, 5784857, 5245324, 10903900, 16436004, 3389013, 1742384,
 14674502, 10279218, 8536112, 10364279, 6877778, 14051163, 1025130, 6072469,
 1988305, 8354440, 8216060, 16342977, 13112639, 3976679, 5913576, 8816697,
 6879995, 14043764, 3339515, 9364420, 15808858, 12261651, 2141560, 5636398,
 10345425, 10414756, 781725, 6155650, 4746914, 5078683, 7469001, 6799140,
 10156444, 9667150, 10116470, 4133858, 2121972, 1124204, 1003577, 1611214,
 14304602, 16221850, 13878465, 13577744, 3629235, 8772583, 10881308, 2410386,
 7300044, 5378855, 9301235, 12755149, 4977682, 8083074, 10327581, 6395087,
 9155434, 15501696, 7514362, 14520507, 15808945, 3244584, 4741962, 9658130,
 14336147, 8654727, 7969093, 15759799, 14029445, 5038459, 9894848, 8659300,
 13699287, 8834306, 10712885, 14753895, 10410465, 3373251, 309501, 9561475,
 5526688, 14647426, 14209836, 5339224, 207299, 14069911, 8722990, 2290950,
 3258216, 12505185, 6007317, 9218111, 14661019, 10537428, 11731949, 9027003,
 6641507, 9490160, 200241, 9720425, 16277895, 10816638, 1554761, 10431375,
 7467528, 6790302, 3429078, 14633753, 14428997, 11463204, 3576212, 2003426,
 6123687, 820520, 9992513, 15784513, 5778891, 6428165, 8388607
};

/*
 * The hardware uses an LFSR counting sequence to determine when to capture
 * the SPU PCs.	 An LFSR sequence is like a puesdo random number sequence
 * where each number occurs once in the sequence but the sequence is not in
 * numerical order. The SPU PC capture is done when the LFSR sequence reaches
 * the last value in the sequence.  Hence the user specified value N
 * corresponds to the LFSR number that is N from the end of the sequence.
 *
 * To avoid the time to compute the LFSR, a lookup table is used.  The 24 bit
 * LFSR sequence is broken into four ranges.  The spacing of the precomputed
 * values is adjusted in each range so the error between the user specifed
 * number (N) of events between samples and the actual number of events based
 * on the precomputed value will be les then about 6.2%.  Note, if the user
 * specifies N < 2^16, the LFSR value that is 2^16 from the end will be used.
 * This is to prevent the loss of samples because the trace buffer is full.
 *
 *	   User specified N		     Step between	   Index in
 *					 precomputed values	 precomputed
 *								    table
 * 0		    to	2^16-1			----		      0
 * 2^16	    to	2^16+2^19-1		2^12		    1 to 128
 * 2^16+2^19	    to	2^16+2^19+2^22-1	2^15		  129 to 256
 * 2^16+2^19+2^22  to	2^24-1			2^18		  257 to 302
 *
 *
 * For example, the LFSR values in the second range are computed for 2^16,
 * 2^16+2^12, ... , 2^19-2^16, 2^19 and stored in the table at indicies
 * 1, 2,..., 127, 128.
 *
 * The 24 bit LFSR value for the nth number in the sequence can be
 * calculated using the following code:
 *
 * #define size 24
 * int calculate_lfsr(int n)
 * {
 *	int i;
 *	unsigned int newlfsr0;
 *	unsigned int lfsr = 0xFFFFFF;
 *	unsigned int howmany = n;
 *
 *	for (i = 2; i < howmany + 2; i++) {
 *		newlfsr0 = (((lfsr >> (size - 1 - 0)) & 1) ^
 *		((lfsr >> (size - 1 - 1)) & 1) ^
 *		(((lfsr >> (size - 1 - 6)) & 1) ^
 *		((lfsr >> (size - 1 - 23)) & 1)));
 *
 *		lfsr >>= 1;
 *		lfsr = lfsr | (newlfsr0 << (size - 1));
 *	}
 *	return lfsr;
 * }
 */

#define V2_16  (0x1 << 16)
#define V2_19  (0x1 << 19)
#define V2_22  (0x1 << 22)

static int calculate_lfsr(int n)
{
	/*
	 * The ranges and steps are in powers of 2 so the calculations
	 * can be done using shifts rather then divide.
	 */
	int index;

	if ((n >> 16) == 0)
		index = 0;
	else if (((n - V2_16) >> 19) == 0)
		index = ((n - V2_16) >> 12) + 1;
	else if (((n - V2_16 - V2_19) >> 22) == 0)
		index = ((n - V2_16 - V2_19) >> 15 ) + 1 + 128;
	else if (((n - V2_16 - V2_19 - V2_22) >> 24) == 0)
		index = ((n - V2_16 - V2_19 - V2_22) >> 18 ) + 1 + 256;
	else
		index = ENTRIES-1;

	/* make sure index is valid */
	if ((index > ENTRIES) || (index < 0))
		index = ENTRIES-1;

	return initial_lfsr[index];
}

static int pm_rtas_activate_spu_profiling(u32 node)
{
	int ret, i;
	struct pm_signal pm_signal_local[NUM_SPUS_PER_NODE];

	/*
	 * Set up the rtas call to configure the debug bus to
	 * route the SPU PCs.  Setup the pm_signal for each SPU
	 */
	for (i = 0; i < ARRAY_SIZE(pm_signal_local); i++) {
		pm_signal_local[i].cpu = node;
		pm_signal_local[i].signal_group = 41;
		/* spu i on word (i/2) */
		pm_signal_local[i].bus_word = 1 << i / 2;
		/* spu i */
		pm_signal_local[i].sub_unit = i;
		pm_signal_local[i].bit = 63;
	}

	ret = rtas_ibm_cbe_perftools(SUBFUNC_ACTIVATE,
				     PASSTHRU_ENABLE, pm_signal_local,
				     (ARRAY_SIZE(pm_signal_local)
				      * sizeof(struct pm_signal)));

	if (unlikely(ret)) {
		printk(KERN_WARNING "%s: rtas returned: %d\n",
		       __func__, ret);
		return -EIO;
	}

	return 0;
}

#ifdef CONFIG_CPU_FREQ
static int
oprof_cpufreq_notify(struct notifier_block *nb, unsigned long val, void *data)
{
	int ret = 0;
	struct cpufreq_freqs *frq = data;
	if ((val == CPUFREQ_PRECHANGE && frq->old < frq->new) ||
	    (val == CPUFREQ_POSTCHANGE && frq->old > frq->new) ||
	    (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE))
		set_spu_profiling_frequency(frq->new, spu_cycle_reset);
	return ret;
}

static struct notifier_block cpu_freq_notifier_block = {
	.notifier_call	= oprof_cpufreq_notify
};
#endif

/*
 * Note the generic OProfile stop calls do not support returning
 * an error on stop.  Hence, will not return an error if the FW
 * calls fail on stop.	Failure to reset the debug bus is not an issue.
 * Failure to disable the SPU profiling is not an issue.  The FW calls
 * to enable the performance counters and debug bus will work even if
 * the hardware was not cleanly reset.
 */
static void cell_global_stop_spu_cycles(void)
{
	int subfunc, rtn_value;
	unsigned int lfsr_value;
	int cpu;

	oprofile_running = 0;
	smp_wmb();

#ifdef CONFIG_CPU_FREQ
	cpufreq_unregister_notifier(&cpu_freq_notifier_block,
				    CPUFREQ_TRANSITION_NOTIFIER);
#endif

	for_each_online_cpu(cpu) {
		if (cbe_get_hw_thread_id(cpu))
			continue;

		subfunc = 3;	/*
				 * 2 - activate SPU tracing,
				 * 3 - deactivate
				 */
		lfsr_value = 0x8f100000;

		rtn_value = rtas_call(spu_rtas_token, 3, 1, NULL,
				      subfunc, cbe_cpu_to_node(cpu),
				      lfsr_value);

		if (unlikely(rtn_value != 0)) {
			printk(KERN_ERR
			       "%s: rtas call ibm,cbe-spu-perftools " \
			       "failed, return = %d\n",
			       __func__, rtn_value);
		}

		/* Deactivate the signals */
		pm_rtas_reset_signals(cbe_cpu_to_node(cpu));
	}

	stop_spu_profiling_cycles();
}

static void cell_global_stop_spu_events(void)
{
	int cpu;
	oprofile_running = 0;

	stop_spu_profiling_events();
	smp_wmb();

	for_each_online_cpu(cpu) {
		if (cbe_get_hw_thread_id(cpu))
			continue;

		cbe_sync_irq(cbe_cpu_to_node(cpu));
		/* Stop the counters */
		cbe_disable_pm(cpu);
		cbe_write_pm07_control(cpu, 0, 0);

		/* Deactivate the signals */
		pm_rtas_reset_signals(cbe_cpu_to_node(cpu));

		/* Deactivate interrupts */
		cbe_disable_pm_interrupts(cpu);
	}
	del_timer_sync(&timer_spu_event_swap);
}

static void cell_global_stop_ppu(void)
{
	int cpu;

	/*
	 * This routine will be called once for the system.
	 * There is one performance monitor per node, so we
	 * only need to perform this function once per node.
	 */
	del_timer_sync(&timer_virt_cntr);
	oprofile_running = 0;
	smp_wmb();

	for_each_online_cpu(cpu) {
		if (cbe_get_hw_thread_id(cpu))
			continue;

		cbe_sync_irq(cbe_cpu_to_node(cpu));
		/* Stop the counters */
		cbe_disable_pm(cpu);

		/* Deactivate the signals */
		pm_rtas_reset_signals(cbe_cpu_to_node(cpu));

		/* Deactivate interrupts */
		cbe_disable_pm_interrupts(cpu);
	}
}

static void cell_global_stop(void)
{
	if (profiling_mode == PPU_PROFILING)
		cell_global_stop_ppu();
	else if (profiling_mode == SPU_PROFILING_EVENTS)
		cell_global_stop_spu_events();
	else
		cell_global_stop_spu_cycles();
}

static int cell_global_start_spu_cycles(struct op_counter_config *ctr)
{
	int subfunc;
	unsigned int lfsr_value;
	int cpu;
	int ret;
	int rtas_error;
	unsigned int cpu_khzfreq = 0;

	/* The SPU profiling uses time-based profiling based on
	 * cpu frequency, so if configured with the CPU_FREQ
	 * option, we should detect frequency changes and react
	 * accordingly.
	 */
#ifdef CONFIG_CPU_FREQ
	ret = cpufreq_register_notifier(&cpu_freq_notifier_block,
					CPUFREQ_TRANSITION_NOTIFIER);
	if (ret < 0)
		/* this is not a fatal error */
		printk(KERN_ERR "CPU freq change registration failed: %d\n",
		       ret);

	else
		cpu_khzfreq = cpufreq_quick_get(smp_processor_id());
#endif

	set_spu_profiling_frequency(cpu_khzfreq, spu_cycle_reset);

	for_each_online_cpu(cpu) {
		if (cbe_get_hw_thread_id(cpu))
			continue;

		/*
		 * Setup SPU cycle-based profiling.
		 * Set perf_mon_control bit 0 to a zero before
		 * enabling spu collection hardware.
		 */
		cbe_write_pm(cpu, pm_control, 0);

		if (spu_cycle_reset > MAX_SPU_COUNT)
			/* use largest possible value */
			lfsr_value = calculate_lfsr(MAX_SPU_COUNT-1);
		else
			lfsr_value = calculate_lfsr(spu_cycle_reset);

		/* must use a non zero value. Zero disables data collection. */
		if (lfsr_value == 0)
			lfsr_value = calculate_lfsr(1);

		lfsr_value = lfsr_value << 8; /* shift lfsr to correct
						* register location
						*/

		/* debug bus setup */
		ret = pm_rtas_activate_spu_profiling(cbe_cpu_to_node(cpu));

		if (unlikely(ret)) {
			rtas_error = ret;
			goto out;
		}


		subfunc = 2;	/* 2 - activate SPU tracing, 3 - deactivate */

		/* start profiling */
		ret = rtas_call(spu_rtas_token, 3, 1, NULL, subfunc,
				cbe_cpu_to_node(cpu), lfsr_value);

		if (unlikely(ret != 0)) {
			printk(KERN_ERR
			       "%s: rtas call ibm,cbe-spu-perftools failed, " \
			       "return = %d\n", __func__, ret);
			rtas_error = -EIO;
			goto out;
		}
	}

	rtas_error = start_spu_profiling_cycles(spu_cycle_reset);
	if (rtas_error)
		goto out_stop;

	oprofile_running = 1;
	return 0;

out_stop:
	cell_global_stop_spu_cycles();	/* clean up the PMU/debug bus */
out:
	return rtas_error;
}

static int cell_global_start_spu_events(struct op_counter_config *ctr)
{
	int cpu;
	u32 interrupt_mask = 0;
	int rtn = 0;

	hdw_thread = 0;

	/* spu event profiling, uses the performance counters to generate
	 * an interrupt.  The hardware is setup to store the SPU program
	 * counter into the trace array.  The occurrence mode is used to
	 * enable storing data to the trace buffer.  The bits are set
	 * to send/store the SPU address in the trace buffer.  The debug
	 * bus must be setup to route the SPU program counter onto the
	 * debug bus.  The occurrence data in the trace buffer is not used.
	 */

	/* This routine gets called once for the system.
	 * There is one performance monitor per node, so we
	 * only need to perform this function once per node.
	 */

	for_each_online_cpu(cpu) {
		if (cbe_get_hw_thread_id(cpu))
			continue;

		/*
		 * Setup SPU event-based profiling.
		 * Set perf_mon_control bit 0 to a zero before
		 * enabling spu collection hardware.
		 *
		 * Only support one SPU event on one SPU per node.
		 */
		if (ctr_enabled & 1) {
			cbe_write_ctr(cpu, 0, reset_value[0]);
			enable_ctr(cpu, 0, pm_regs.pm07_cntrl);
			interrupt_mask |=
				CBE_PM_CTR_OVERFLOW_INTR(0);
		} else {
			/* Disable counter */
			cbe_write_pm07_control(cpu, 0, 0);
		}

		cbe_get_and_clear_pm_interrupts(cpu);
		cbe_enable_pm_interrupts(cpu, hdw_thread, interrupt_mask);
		cbe_enable_pm(cpu);

		/* clear the trace buffer */
		cbe_write_pm(cpu, trace_address, 0);
	}

	/* Start the timer to time slice collecting the event profile
	 * on each of the SPUs.  Note, can collect profile on one SPU
	 * per node at a time.
	 */
	start_spu_event_swap();
	start_spu_profiling_events();
	oprofile_running = 1;
	smp_wmb();

	return rtn;
}

static int cell_global_start_ppu(struct op_counter_config *ctr)
{
	u32 cpu, i;
	u32 interrupt_mask = 0;

	/* This routine gets called once for the system.
	 * There is one performance monitor per node, so we
	 * only need to perform this function once per node.
	 */
	for_each_online_cpu(cpu) {
		if (cbe_get_hw_thread_id(cpu))
			continue;

		interrupt_mask = 0;

		for (i = 0; i < num_counters; ++i) {
			if (ctr_enabled & (1 << i)) {
				cbe_write_ctr(cpu, i, reset_value[i]);
				enable_ctr(cpu, i, pm_regs.pm07_cntrl);
				interrupt_mask |= CBE_PM_CTR_OVERFLOW_INTR(i);
			} else {
				/* Disable counter */
				cbe_write_pm07_control(cpu, i, 0);
			}
		}

		cbe_get_and_clear_pm_interrupts(cpu);
		cbe_enable_pm_interrupts(cpu, hdw_thread, interrupt_mask);
		cbe_enable_pm(cpu);
	}

	virt_cntr_inter_mask = interrupt_mask;
	oprofile_running = 1;
	smp_wmb();

	/*
	 * NOTE: start_virt_cntrs will result in cell_virtual_cntr() being
	 * executed which manipulates the PMU.	We start the "virtual counter"
	 * here so that we do not need to synchronize access to the PMU in
	 * the above for-loop.
	 */
	start_virt_cntrs();

	return 0;
}

static int cell_global_start(struct op_counter_config *ctr)
{
	if (profiling_mode == SPU_PROFILING_CYCLES)
		return cell_global_start_spu_cycles(ctr);
	else if (profiling_mode == SPU_PROFILING_EVENTS)
		return cell_global_start_spu_events(ctr);
	else
		return cell_global_start_ppu(ctr);
}


/* The SPU interrupt handler
 *
 * SPU event profiling works as follows:
 * The pm_signal[0] holds the one SPU event to be measured.  It is routed on
 * the debug bus using word 0 or 1.  The value of pm_signal[1] and
 * pm_signal[2] contain the necessary events to route the SPU program
 * counter for the selected SPU onto the debug bus using words 2 and 3.
 * The pm_interval register is setup to write the SPU PC value into the
 * trace buffer at the maximum rate possible.  The trace buffer is configured
 * to store the PCs, wrapping when it is full.  The performance counter is
 * intialized to the max hardware count minus the number of events, N, between
 * samples.  Once the N events have occured, a HW counter overflow occurs
 * causing the generation of a HW counter interrupt which also stops the
 * writing of the SPU PC values to the trace buffer.  Hence the last PC
 * written to the trace buffer is the SPU PC that we want.  Unfortunately,
 * we have to read from the beginning of the trace buffer to get to the
 * last value written.  We just hope the PPU has nothing better to do then
 * service this interrupt. The PC for the specific SPU being profiled is
 * extracted from the trace buffer processed and stored.  The trace buffer
 * is cleared, interrupts are cleared, the counter is reset to max - N.
 * A kernel timer is used to periodically call the routine spu_evnt_swap()
 * to switch to the next physical SPU in the node to profile in round robbin
 * order.  This way data is collected for all SPUs on the node. It does mean
 * that we need to use a relatively small value of N to ensure enough samples
 * on each SPU are collected each SPU is being profiled 1/8 of the time.
 * It may also be necessary to use a longer sample collection period.
 */
static void cell_handle_interrupt_spu(struct pt_regs *regs,
				      struct op_counter_config *ctr)
{
	u32 cpu, cpu_tmp;
	u64 trace_entry;
	u32 interrupt_mask;
	u64 trace_buffer[2];
	u64 last_trace_buffer;
	u32 sample;
	u32 trace_addr;
	unsigned long sample_array_lock_flags;
	int spu_num;
	unsigned long flags;

	/* Make sure spu event interrupt handler and spu event swap
	 * don't access the counters simultaneously.
	 */
	cpu = smp_processor_id();
	spin_lock_irqsave(&cntr_lock, flags);

	cpu_tmp = cpu;
	cbe_disable_pm(cpu);

	interrupt_mask = cbe_get_and_clear_pm_interrupts(cpu);

	sample = 0xABCDEF;
	trace_entry = 0xfedcba;
	last_trace_buffer = 0xdeadbeaf;

	if ((oprofile_running == 1) && (interrupt_mask != 0)) {
		/* disable writes to trace buff */
		cbe_write_pm(cpu, pm_interval, 0);

		/* only have one perf cntr being used, cntr 0 */
		if ((interrupt_mask & CBE_PM_CTR_OVERFLOW_INTR(0))
		    && ctr[0].enabled)
			/* The SPU PC values will be read
			 * from the trace buffer, reset counter
			 */

			cbe_write_ctr(cpu, 0, reset_value[0]);

		trace_addr = cbe_read_pm(cpu, trace_address);

		while (!(trace_addr & CBE_PM_TRACE_BUF_EMPTY)) {
			/* There is data in the trace buffer to process
			 * Read the buffer until you get to the last
			 * entry.  This is the value we want.
			 */

			cbe_read_trace_buffer(cpu, trace_buffer);
			trace_addr = cbe_read_pm(cpu, trace_address);
		}

		/* SPU Address 16 bit count format for 128 bit
		 * HW trace buffer is used for the SPU PC storage
		 *    HDR bits          0:15
		 *    SPU Addr 0 bits   16:31
		 *    SPU Addr 1 bits   32:47
		 *    unused bits       48:127
		 *
		 * HDR: bit4 = 1 SPU Address 0 valid
		 * HDR: bit5 = 1 SPU Address 1 valid
		 *  - unfortunately, the valid bits don't seem to work
		 *
		 * Note trace_buffer[0] holds bits 0:63 of the HW
		 * trace buffer, trace_buffer[1] holds bits 64:127
		 */

		trace_entry = trace_buffer[0]
			& 0x00000000FFFF0000;

		/* only top 16 of the 18 bit SPU PC address
		 * is stored in trace buffer, hence shift right
		 * by 16 -2 bits */
		sample = trace_entry >> 14;
		last_trace_buffer = trace_buffer[0];

		spu_num = spu_evnt_phys_spu_indx
			+ (cbe_cpu_to_node(cpu) * NUM_SPUS_PER_NODE);

		/* make sure only one process at a time is calling
		 * spu_sync_buffer()
		 */
		spin_lock_irqsave(&oprof_spu_smpl_arry_lck,
				  sample_array_lock_flags);
		spu_sync_buffer(spu_num, &sample, 1);
		spin_unlock_irqrestore(&oprof_spu_smpl_arry_lck,
				       sample_array_lock_flags);

		smp_wmb();    /* insure spu event buffer updates are written
			       * don't want events intermingled... */

		/* The counters were frozen by the interrupt.
		 * Reenable the interrupt and restart the counters.
		 */
		cbe_write_pm(cpu, pm_interval, NUM_INTERVAL_CYC);
		cbe_enable_pm_interrupts(cpu, hdw_thread,
					 virt_cntr_inter_mask);

		/* clear the trace buffer, re-enable writes to trace buff */
		cbe_write_pm(cpu, trace_address, 0);
		cbe_write_pm(cpu, pm_interval, NUM_INTERVAL_CYC);

		/* The writes to the various performance counters only writes
		 * to a latch.  The new values (interrupt setting bits, reset
		 * counter value etc.) are not copied to the actual registers
		 * until the performance monitor is enabled.  In order to get
		 * this to work as desired, the permormance monitor needs to
		 * be disabled while writing to the latches.  This is a
		 * HW design issue.
		 */
		write_pm_cntrl(cpu);
		cbe_enable_pm(cpu);
	}
	spin_unlock_irqrestore(&cntr_lock, flags);
}

static void cell_handle_interrupt_ppu(struct pt_regs *regs,
				      struct op_counter_config *ctr)
{
	u32 cpu;
	u64 pc;
	int is_kernel;
	unsigned long flags = 0;
	u32 interrupt_mask;
	int i;

	cpu = smp_processor_id();

	/*
	 * Need to make sure the interrupt handler and the virt counter
	 * routine are not running at the same time. See the
	 * cell_virtual_cntr() routine for additional comments.
	 */
	spin_lock_irqsave(&cntr_lock, flags);

	/*
	 * Need to disable and reenable the performance counters
	 * to get the desired behavior from the hardware.  This
	 * is hardware specific.
	 */

	cbe_disable_pm(cpu);

	interrupt_mask = cbe_get_and_clear_pm_interrupts(cpu);

	/*
	 * If the interrupt mask has been cleared, then the virt cntr
	 * has cleared the interrupt.  When the thread that generated
	 * the interrupt is restored, the data count will be restored to
	 * 0xffffff0 to cause the interrupt to be regenerated.
	 */

	if ((oprofile_running == 1) && (interrupt_mask != 0)) {
		pc = regs->nip;
		is_kernel = is_kernel_addr(pc);

		for (i = 0; i < num_counters; ++i) {
			if ((interrupt_mask & CBE_PM_CTR_OVERFLOW_INTR(i))
			    && ctr[i].enabled) {
				oprofile_add_ext_sample(pc, regs, i, is_kernel);
				cbe_write_ctr(cpu, i, reset_value[i]);
			}
		}

		/*
		 * The counters were frozen by the interrupt.
		 * Reenable the interrupt and restart the counters.
		 * If there was a race between the interrupt handler and
		 * the virtual counter routine.	 The virutal counter
		 * routine may have cleared the interrupts.  Hence must
		 * use the virt_cntr_inter_mask to re-enable the interrupts.
		 */
		cbe_enable_pm_interrupts(cpu, hdw_thread,
					 virt_cntr_inter_mask);

		/*
		 * The writes to the various performance counters only writes
		 * to a latch.	The new values (interrupt setting bits, reset
		 * counter value etc.) are not copied to the actual registers
		 * until the performance monitor is enabled.  In order to get
		 * this to work as desired, the permormance monitor needs to
		 * be disabled while writing to the latches.  This is a
		 * HW design issue.
		 */
		cbe_enable_pm(cpu);
	}
	spin_unlock_irqrestore(&cntr_lock, flags);
}

static void cell_handle_interrupt(struct pt_regs *regs,
				  struct op_counter_config *ctr)
{
	if (profiling_mode == PPU_PROFILING)
		cell_handle_interrupt_ppu(regs, ctr);
	else
		cell_handle_interrupt_spu(regs, ctr);
}

/*
 * This function is called from the generic OProfile
 * driver.  When profiling PPUs, we need to do the
 * generic sync start; otherwise, do spu_sync_start.
 */
static int cell_sync_start(void)
{
	if ((profiling_mode == SPU_PROFILING_CYCLES) ||
	    (profiling_mode == SPU_PROFILING_EVENTS))
		return spu_sync_start();
	else
		return DO_GENERIC_SYNC;
}

static int cell_sync_stop(void)
{
	if ((profiling_mode == SPU_PROFILING_CYCLES) ||
	    (profiling_mode == SPU_PROFILING_EVENTS))
		return spu_sync_stop();
	else
		return 1;
}

struct op_powerpc_model op_model_cell = {
	.reg_setup = cell_reg_setup,
	.cpu_setup = cell_cpu_setup,
	.global_start = cell_global_start,
	.global_stop = cell_global_stop,
	.sync_start = cell_sync_start,
	.sync_stop = cell_sync_stop,
	.handle_interrupt = cell_handle_interrupt,
};
OpenPOWER on IntegriCloud