summaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/exceptions-64s.S
blob: 3e423fbad6bcd40b82226002466f1ff911f2c437 (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
/*
 * This file contains the 64-bit "server" PowerPC variant
 * of the low level exception handling including exception
 * vectors, exception return, part of the slb and stab
 * handling and other fixed offset specific things.
 *
 * This file is meant to be #included from head_64.S due to
 * position dependant assembly.
 *
 * Most of this originates from head_64.S and thus has the same
 * copyright history.
 *
 */

#include <asm/exception-64s.h>

/*
 * We layout physical memory as follows:
 * 0x0000 - 0x00ff : Secondary processor spin code
 * 0x0100 - 0x2fff : pSeries Interrupt prologs
 * 0x3000 - 0x5fff : interrupt support, iSeries and common interrupt prologs
 * 0x6000 - 0x6fff : Initial (CPU0) segment table
 * 0x7000 - 0x7fff : FWNMI data area
 * 0x8000 -        : Early init and support code
 */

/*
 * This is the start of the interrupt handlers for pSeries
 * This code runs with relocation off.
 * Code from here to __end_interrupts gets copied down to real
 * address 0x100 when we are running a relocatable kernel.
 * Therefore any relative branches in this section must only
 * branch to labels in this section.
 */
	. = 0x100
	.globl __start_interrupts
__start_interrupts:

	STD_EXCEPTION_PSERIES(0x100, system_reset)

	. = 0x200
_machine_check_pSeries:
	HMT_MEDIUM
	DO_KVM	0x200
	mtspr	SPRN_SPRG_SCRATCH0,r13		/* save r13 */
	EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)

	. = 0x300
	.globl data_access_pSeries
data_access_pSeries:
	HMT_MEDIUM
	DO_KVM	0x300
	mtspr	SPRN_SPRG_SCRATCH0,r13
BEGIN_FTR_SECTION
	mfspr	r13,SPRN_SPRG_PACA
	std	r9,PACA_EXSLB+EX_R9(r13)
	std	r10,PACA_EXSLB+EX_R10(r13)
	mfspr	r10,SPRN_DAR
	mfspr	r9,SPRN_DSISR
	srdi	r10,r10,60
	rlwimi	r10,r9,16,0x20
	mfcr	r9
	cmpwi	r10,0x2c
	beq	do_stab_bolted_pSeries
	ld	r10,PACA_EXSLB+EX_R10(r13)
	std	r11,PACA_EXGEN+EX_R11(r13)
	ld	r11,PACA_EXSLB+EX_R9(r13)
	std	r12,PACA_EXGEN+EX_R12(r13)
	mfspr	r12,SPRN_SPRG_SCRATCH0
	std	r10,PACA_EXGEN+EX_R10(r13)
	std	r11,PACA_EXGEN+EX_R9(r13)
	std	r12,PACA_EXGEN+EX_R13(r13)
	EXCEPTION_PROLOG_PSERIES_1(data_access_common)
FTR_SECTION_ELSE
	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, data_access_common)
ALT_FTR_SECTION_END_IFCLR(CPU_FTR_SLB)

	. = 0x380
	.globl data_access_slb_pSeries
data_access_slb_pSeries:
	HMT_MEDIUM
	DO_KVM	0x380
	mtspr	SPRN_SPRG_SCRATCH0,r13
	mfspr	r13,SPRN_SPRG_PACA		/* get paca address into r13 */
	std	r3,PACA_EXSLB+EX_R3(r13)
	mfspr	r3,SPRN_DAR
	std	r9,PACA_EXSLB+EX_R9(r13)	/* save r9 - r12 */
	mfcr	r9
#ifdef __DISABLED__
	/* Keep that around for when we re-implement dynamic VSIDs */
	cmpdi	r3,0
	bge	slb_miss_user_pseries
#endif /* __DISABLED__ */
	std	r10,PACA_EXSLB+EX_R10(r13)
	std	r11,PACA_EXSLB+EX_R11(r13)
	std	r12,PACA_EXSLB+EX_R12(r13)
	mfspr	r10,SPRN_SPRG_SCRATCH0
	std	r10,PACA_EXSLB+EX_R13(r13)
	mfspr	r12,SPRN_SRR1		/* and SRR1 */
#ifndef CONFIG_RELOCATABLE
	b	.slb_miss_realmode
#else
	/*
	 * We can't just use a direct branch to .slb_miss_realmode
	 * because the distance from here to there depends on where
	 * the kernel ends up being put.
	 */
	mfctr	r11
	ld	r10,PACAKBASE(r13)
	LOAD_HANDLER(r10, .slb_miss_realmode)
	mtctr	r10
	bctr
#endif

	STD_EXCEPTION_PSERIES(0x400, instruction_access)

	. = 0x480
	.globl instruction_access_slb_pSeries
instruction_access_slb_pSeries:
	HMT_MEDIUM
	DO_KVM	0x480
	mtspr	SPRN_SPRG_SCRATCH0,r13
	mfspr	r13,SPRN_SPRG_PACA		/* get paca address into r13 */
	std	r3,PACA_EXSLB+EX_R3(r13)
	mfspr	r3,SPRN_SRR0		/* SRR0 is faulting address */
	std	r9,PACA_EXSLB+EX_R9(r13)	/* save r9 - r12 */
	mfcr	r9
#ifdef __DISABLED__
	/* Keep that around for when we re-implement dynamic VSIDs */
	cmpdi	r3,0
	bge	slb_miss_user_pseries
#endif /* __DISABLED__ */
	std	r10,PACA_EXSLB+EX_R10(r13)
	std	r11,PACA_EXSLB+EX_R11(r13)
	std	r12,PACA_EXSLB+EX_R12(r13)
	mfspr	r10,SPRN_SPRG_SCRATCH0
	std	r10,PACA_EXSLB+EX_R13(r13)
	mfspr	r12,SPRN_SRR1		/* and SRR1 */
#ifndef CONFIG_RELOCATABLE
	b	.slb_miss_realmode
#else
	mfctr	r11
	ld	r10,PACAKBASE(r13)
	LOAD_HANDLER(r10, .slb_miss_realmode)
	mtctr	r10
	bctr
#endif

	MASKABLE_EXCEPTION_PSERIES(0x500, hardware_interrupt)
	STD_EXCEPTION_PSERIES(0x600, alignment)
	STD_EXCEPTION_PSERIES(0x700, program_check)
	STD_EXCEPTION_PSERIES(0x800, fp_unavailable)
	MASKABLE_EXCEPTION_PSERIES(0x900, decrementer)
	STD_EXCEPTION_PSERIES(0xa00, trap_0a)
	STD_EXCEPTION_PSERIES(0xb00, trap_0b)

	. = 0xc00
	.globl	system_call_pSeries
system_call_pSeries:
	HMT_MEDIUM
	DO_KVM	0xc00
BEGIN_FTR_SECTION
	cmpdi	r0,0x1ebe
	beq-	1f
END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE)
	mr	r9,r13
	mfspr	r13,SPRN_SPRG_PACA
	mfspr	r11,SPRN_SRR0
	ld	r12,PACAKBASE(r13)
	ld	r10,PACAKMSR(r13)
	LOAD_HANDLER(r12, system_call_entry)
	mtspr	SPRN_SRR0,r12
	mfspr	r12,SPRN_SRR1
	mtspr	SPRN_SRR1,r10
	rfid
	b	.	/* prevent speculative execution */

/* Fast LE/BE switch system call */
1:	mfspr	r12,SPRN_SRR1
	xori	r12,r12,MSR_LE
	mtspr	SPRN_SRR1,r12
	rfid		/* return to userspace */
	b	.

	STD_EXCEPTION_PSERIES(0xd00, single_step)
	STD_EXCEPTION_PSERIES(0xe00, trap_0e)

	/* We need to deal with the Altivec unavailable exception
	 * here which is at 0xf20, thus in the middle of the
	 * prolog code of the PerformanceMonitor one. A little
	 * trickery is thus necessary
	 */
performance_monitor_pSeries_1:
	. = 0xf00
	DO_KVM	0xf00
	b	performance_monitor_pSeries

altivec_unavailable_pSeries_1:
	. = 0xf20
	DO_KVM	0xf20
	b	altivec_unavailable_pSeries

vsx_unavailable_pSeries_1:
	. = 0xf40
	DO_KVM	0xf40
	b	vsx_unavailable_pSeries

#ifdef CONFIG_CBE_RAS
	HSTD_EXCEPTION_PSERIES(0x1200, cbe_system_error)
#endif /* CONFIG_CBE_RAS */
	STD_EXCEPTION_PSERIES(0x1300, instruction_breakpoint)
#ifdef CONFIG_CBE_RAS
	HSTD_EXCEPTION_PSERIES(0x1600, cbe_maintenance)
#endif /* CONFIG_CBE_RAS */
	STD_EXCEPTION_PSERIES(0x1700, altivec_assist)
#ifdef CONFIG_CBE_RAS
	HSTD_EXCEPTION_PSERIES(0x1800, cbe_thermal)
#endif /* CONFIG_CBE_RAS */

	. = 0x3000

/*** pSeries interrupt support ***/

	/* moved from 0xf00 */
	STD_EXCEPTION_PSERIES(., performance_monitor)
	STD_EXCEPTION_PSERIES(., altivec_unavailable)
	STD_EXCEPTION_PSERIES(., vsx_unavailable)

/*
 * An interrupt came in while soft-disabled; clear EE in SRR1,
 * clear paca->hard_enabled and return.
 */
masked_interrupt:
	stb	r10,PACAHARDIRQEN(r13)
	mtcrf	0x80,r9
	ld	r9,PACA_EXGEN+EX_R9(r13)
	mfspr	r10,SPRN_SRR1
	rldicl	r10,r10,48,1		/* clear MSR_EE */
	rotldi	r10,r10,16
	mtspr	SPRN_SRR1,r10
	ld	r10,PACA_EXGEN+EX_R10(r13)
	mfspr	r13,SPRN_SPRG_SCRATCH0
	rfid
	b	.

	.align	7
do_stab_bolted_pSeries:
	std	r11,PACA_EXSLB+EX_R11(r13)
	std	r12,PACA_EXSLB+EX_R12(r13)
	mfspr	r10,SPRN_SPRG_SCRATCH0
	std	r10,PACA_EXSLB+EX_R13(r13)
	EXCEPTION_PROLOG_PSERIES_1(.do_stab_bolted)

#ifdef CONFIG_PPC_PSERIES
/*
 * Vectors for the FWNMI option.  Share common code.
 */
	.globl system_reset_fwnmi
      .align 7
system_reset_fwnmi:
	HMT_MEDIUM
	mtspr	SPRN_SPRG_SCRATCH0,r13		/* save r13 */
	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common)

	.globl machine_check_fwnmi
      .align 7
machine_check_fwnmi:
	HMT_MEDIUM
	mtspr	SPRN_SPRG_SCRATCH0,r13		/* save r13 */
	EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)

#endif /* CONFIG_PPC_PSERIES */

#ifdef __DISABLED__
/*
 * This is used for when the SLB miss handler has to go virtual,
 * which doesn't happen for now anymore but will once we re-implement
 * dynamic VSIDs for shared page tables
 */
slb_miss_user_pseries:
	std	r10,PACA_EXGEN+EX_R10(r13)
	std	r11,PACA_EXGEN+EX_R11(r13)
	std	r12,PACA_EXGEN+EX_R12(r13)
	mfspr	r10,SPRG_SCRATCH0
	ld	r11,PACA_EXSLB+EX_R9(r13)
	ld	r12,PACA_EXSLB+EX_R3(r13)
	std	r10,PACA_EXGEN+EX_R13(r13)
	std	r11,PACA_EXGEN+EX_R9(r13)
	std	r12,PACA_EXGEN+EX_R3(r13)
	clrrdi	r12,r13,32
	mfmsr	r10
	mfspr	r11,SRR0			/* save SRR0 */
	ori	r12,r12,slb_miss_user_common@l	/* virt addr of handler */
	ori	r10,r10,MSR_IR|MSR_DR|MSR_RI
	mtspr	SRR0,r12
	mfspr	r12,SRR1			/* and SRR1 */
	mtspr	SRR1,r10
	rfid
	b	.				/* prevent spec. execution */
#endif /* __DISABLED__ */

	.align	7
	.globl	__end_interrupts
__end_interrupts:

/*
 * Code from here down to __end_handlers is invoked from the
 * exception prologs above.  Because the prologs assemble the
 * addresses of these handlers using the LOAD_HANDLER macro,
 * which uses an addi instruction, these handlers must be in
 * the first 32k of the kernel image.
 */

/*** Common interrupt handlers ***/

	STD_EXCEPTION_COMMON(0x100, system_reset, .system_reset_exception)

	/*
	 * Machine check is different because we use a different
	 * save area: PACA_EXMC instead of PACA_EXGEN.
	 */
	.align	7
	.globl machine_check_common
machine_check_common:
	EXCEPTION_PROLOG_COMMON(0x200, PACA_EXMC)
	FINISH_NAP
	DISABLE_INTS
	bl	.save_nvgprs
	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.machine_check_exception
	b	.ret_from_except

	STD_EXCEPTION_COMMON_LITE(0x900, decrementer, .timer_interrupt)
	STD_EXCEPTION_COMMON(0xa00, trap_0a, .unknown_exception)
	STD_EXCEPTION_COMMON(0xb00, trap_0b, .unknown_exception)
	STD_EXCEPTION_COMMON(0xd00, single_step, .single_step_exception)
	STD_EXCEPTION_COMMON(0xe00, trap_0e, .unknown_exception)
	STD_EXCEPTION_COMMON_IDLE(0xf00, performance_monitor, .performance_monitor_exception)
	STD_EXCEPTION_COMMON(0x1300, instruction_breakpoint, .instruction_breakpoint_exception)
#ifdef CONFIG_ALTIVEC
	STD_EXCEPTION_COMMON(0x1700, altivec_assist, .altivec_assist_exception)
#else
	STD_EXCEPTION_COMMON(0x1700, altivec_assist, .unknown_exception)
#endif
#ifdef CONFIG_CBE_RAS
	STD_EXCEPTION_COMMON(0x1200, cbe_system_error, .cbe_system_error_exception)
	STD_EXCEPTION_COMMON(0x1600, cbe_maintenance, .cbe_maintenance_exception)
	STD_EXCEPTION_COMMON(0x1800, cbe_thermal, .cbe_thermal_exception)
#endif /* CONFIG_CBE_RAS */

	.align	7
system_call_entry:
	b	system_call_common

/*
 * Here we have detected that the kernel stack pointer is bad.
 * R9 contains the saved CR, r13 points to the paca,
 * r10 contains the (bad) kernel stack pointer,
 * r11 and r12 contain the saved SRR0 and SRR1.
 * We switch to using an emergency stack, save the registers there,
 * and call kernel_bad_stack(), which panics.
 */
bad_stack:
	ld	r1,PACAEMERGSP(r13)
	subi	r1,r1,64+INT_FRAME_SIZE
	std	r9,_CCR(r1)
	std	r10,GPR1(r1)
	std	r11,_NIP(r1)
	std	r12,_MSR(r1)
	mfspr	r11,SPRN_DAR
	mfspr	r12,SPRN_DSISR
	std	r11,_DAR(r1)
	std	r12,_DSISR(r1)
	mflr	r10
	mfctr	r11
	mfxer	r12
	std	r10,_LINK(r1)
	std	r11,_CTR(r1)
	std	r12,_XER(r1)
	SAVE_GPR(0,r1)
	SAVE_GPR(2,r1)
	SAVE_4GPRS(3,r1)
	SAVE_2GPRS(7,r1)
	SAVE_10GPRS(12,r1)
	SAVE_10GPRS(22,r1)
	lhz	r12,PACA_TRAP_SAVE(r13)
	std	r12,_TRAP(r1)
	addi	r11,r1,INT_FRAME_SIZE
	std	r11,0(r1)
	li	r12,0
	std	r12,0(r11)
	ld	r2,PACATOC(r13)
1:	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.kernel_bad_stack
	b	1b

/*
 * Here r13 points to the paca, r9 contains the saved CR,
 * SRR0 and SRR1 are saved in r11 and r12,
 * r9 - r13 are saved in paca->exgen.
 */
	.align	7
	.globl data_access_common
data_access_common:
	mfspr	r10,SPRN_DAR
	std	r10,PACA_EXGEN+EX_DAR(r13)
	mfspr	r10,SPRN_DSISR
	stw	r10,PACA_EXGEN+EX_DSISR(r13)
	EXCEPTION_PROLOG_COMMON(0x300, PACA_EXGEN)
	ld	r3,PACA_EXGEN+EX_DAR(r13)
	lwz	r4,PACA_EXGEN+EX_DSISR(r13)
	li	r5,0x300
	b	.do_hash_page	 	/* Try to handle as hpte fault */

	.align	7
	.globl instruction_access_common
instruction_access_common:
	EXCEPTION_PROLOG_COMMON(0x400, PACA_EXGEN)
	ld	r3,_NIP(r1)
	andis.	r4,r12,0x5820
	li	r5,0x400
	b	.do_hash_page		/* Try to handle as hpte fault */

/*
 * Here is the common SLB miss user that is used when going to virtual
 * mode for SLB misses, that is currently not used
 */
#ifdef __DISABLED__
	.align	7
	.globl	slb_miss_user_common
slb_miss_user_common:
	mflr	r10
	std	r3,PACA_EXGEN+EX_DAR(r13)
	stw	r9,PACA_EXGEN+EX_CCR(r13)
	std	r10,PACA_EXGEN+EX_LR(r13)
	std	r11,PACA_EXGEN+EX_SRR0(r13)
	bl	.slb_allocate_user

	ld	r10,PACA_EXGEN+EX_LR(r13)
	ld	r3,PACA_EXGEN+EX_R3(r13)
	lwz	r9,PACA_EXGEN+EX_CCR(r13)
	ld	r11,PACA_EXGEN+EX_SRR0(r13)
	mtlr	r10
	beq-	slb_miss_fault

	andi.	r10,r12,MSR_RI		/* check for unrecoverable exception */
	beq-	unrecov_user_slb
	mfmsr	r10

.machine push
.machine "power4"
	mtcrf	0x80,r9
.machine pop

	clrrdi	r10,r10,2		/* clear RI before setting SRR0/1 */
	mtmsrd	r10,1

	mtspr	SRR0,r11
	mtspr	SRR1,r12

	ld	r9,PACA_EXGEN+EX_R9(r13)
	ld	r10,PACA_EXGEN+EX_R10(r13)
	ld	r11,PACA_EXGEN+EX_R11(r13)
	ld	r12,PACA_EXGEN+EX_R12(r13)
	ld	r13,PACA_EXGEN+EX_R13(r13)
	rfid
	b	.

slb_miss_fault:
	EXCEPTION_PROLOG_COMMON(0x380, PACA_EXGEN)
	ld	r4,PACA_EXGEN+EX_DAR(r13)
	li	r5,0
	std	r4,_DAR(r1)
	std	r5,_DSISR(r1)
	b	handle_page_fault

unrecov_user_slb:
	EXCEPTION_PROLOG_COMMON(0x4200, PACA_EXGEN)
	DISABLE_INTS
	bl	.save_nvgprs
1:	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.unrecoverable_exception
	b	1b

#endif /* __DISABLED__ */


/*
 * r13 points to the PACA, r9 contains the saved CR,
 * r12 contain the saved SRR1, SRR0 is still ready for return
 * r3 has the faulting address
 * r9 - r13 are saved in paca->exslb.
 * r3 is saved in paca->slb_r3
 * We assume we aren't going to take any exceptions during this procedure.
 */
_GLOBAL(slb_miss_realmode)
	mflr	r10
#ifdef CONFIG_RELOCATABLE
	mtctr	r11
#endif

	stw	r9,PACA_EXSLB+EX_CCR(r13)	/* save CR in exc. frame */
	std	r10,PACA_EXSLB+EX_LR(r13)	/* save LR */

	bl	.slb_allocate_realmode

	/* All done -- return from exception. */

	ld	r10,PACA_EXSLB+EX_LR(r13)
	ld	r3,PACA_EXSLB+EX_R3(r13)
	lwz	r9,PACA_EXSLB+EX_CCR(r13)	/* get saved CR */
#ifdef CONFIG_PPC_ISERIES
BEGIN_FW_FTR_SECTION
	ld	r11,PACALPPACAPTR(r13)
	ld	r11,LPPACASRR0(r11)		/* get SRR0 value */
END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
#endif /* CONFIG_PPC_ISERIES */

	mtlr	r10

	andi.	r10,r12,MSR_RI	/* check for unrecoverable exception */
	beq-	2f

.machine	push
.machine	"power4"
	mtcrf	0x80,r9
	mtcrf	0x01,r9		/* slb_allocate uses cr0 and cr7 */
.machine	pop

#ifdef CONFIG_PPC_ISERIES
BEGIN_FW_FTR_SECTION
	mtspr	SPRN_SRR0,r11
	mtspr	SPRN_SRR1,r12
END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
#endif /* CONFIG_PPC_ISERIES */
	ld	r9,PACA_EXSLB+EX_R9(r13)
	ld	r10,PACA_EXSLB+EX_R10(r13)
	ld	r11,PACA_EXSLB+EX_R11(r13)
	ld	r12,PACA_EXSLB+EX_R12(r13)
	ld	r13,PACA_EXSLB+EX_R13(r13)
	rfid
	b	.	/* prevent speculative execution */

2:
#ifdef CONFIG_PPC_ISERIES
BEGIN_FW_FTR_SECTION
	b	unrecov_slb
END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
#endif /* CONFIG_PPC_ISERIES */
	mfspr	r11,SPRN_SRR0
	ld	r10,PACAKBASE(r13)
	LOAD_HANDLER(r10,unrecov_slb)
	mtspr	SPRN_SRR0,r10
	ld	r10,PACAKMSR(r13)
	mtspr	SPRN_SRR1,r10
	rfid
	b	.

unrecov_slb:
	EXCEPTION_PROLOG_COMMON(0x4100, PACA_EXSLB)
	DISABLE_INTS
	bl	.save_nvgprs
1:	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.unrecoverable_exception
	b	1b

	.align	7
	.globl hardware_interrupt_common
	.globl hardware_interrupt_entry
hardware_interrupt_common:
	EXCEPTION_PROLOG_COMMON(0x500, PACA_EXGEN)
	FINISH_NAP
hardware_interrupt_entry:
	DISABLE_INTS
BEGIN_FTR_SECTION
	bl	.ppc64_runlatch_on
END_FTR_SECTION_IFSET(CPU_FTR_CTRL)
	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.do_IRQ
	b	.ret_from_except_lite

#ifdef CONFIG_PPC_970_NAP
power4_fixup_nap:
	andc	r9,r9,r10
	std	r9,TI_LOCAL_FLAGS(r11)
	ld	r10,_LINK(r1)		/* make idle task do the */
	std	r10,_NIP(r1)		/* equivalent of a blr */
	blr
#endif

	.align	7
	.globl alignment_common
alignment_common:
	mfspr	r10,SPRN_DAR
	std	r10,PACA_EXGEN+EX_DAR(r13)
	mfspr	r10,SPRN_DSISR
	stw	r10,PACA_EXGEN+EX_DSISR(r13)
	EXCEPTION_PROLOG_COMMON(0x600, PACA_EXGEN)
	ld	r3,PACA_EXGEN+EX_DAR(r13)
	lwz	r4,PACA_EXGEN+EX_DSISR(r13)
	std	r3,_DAR(r1)
	std	r4,_DSISR(r1)
	bl	.save_nvgprs
	addi	r3,r1,STACK_FRAME_OVERHEAD
	ENABLE_INTS
	bl	.alignment_exception
	b	.ret_from_except

	.align	7
	.globl program_check_common
program_check_common:
	EXCEPTION_PROLOG_COMMON(0x700, PACA_EXGEN)
	bl	.save_nvgprs
	addi	r3,r1,STACK_FRAME_OVERHEAD
	ENABLE_INTS
	bl	.program_check_exception
	b	.ret_from_except

	.align	7
	.globl fp_unavailable_common
fp_unavailable_common:
	EXCEPTION_PROLOG_COMMON(0x800, PACA_EXGEN)
	bne	1f			/* if from user, just load it up */
	bl	.save_nvgprs
	addi	r3,r1,STACK_FRAME_OVERHEAD
	ENABLE_INTS
	bl	.kernel_fp_unavailable_exception
	BUG_OPCODE
1:	bl	.load_up_fpu
	b	fast_exception_return

	.align	7
	.globl altivec_unavailable_common
altivec_unavailable_common:
	EXCEPTION_PROLOG_COMMON(0xf20, PACA_EXGEN)
#ifdef CONFIG_ALTIVEC
BEGIN_FTR_SECTION
	beq	1f
	bl	.load_up_altivec
	b	fast_exception_return
1:
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif
	bl	.save_nvgprs
	addi	r3,r1,STACK_FRAME_OVERHEAD
	ENABLE_INTS
	bl	.altivec_unavailable_exception
	b	.ret_from_except

	.align	7
	.globl vsx_unavailable_common
vsx_unavailable_common:
	EXCEPTION_PROLOG_COMMON(0xf40, PACA_EXGEN)
#ifdef CONFIG_VSX
BEGIN_FTR_SECTION
	bne	.load_up_vsx
1:
END_FTR_SECTION_IFSET(CPU_FTR_VSX)
#endif
	bl	.save_nvgprs
	addi	r3,r1,STACK_FRAME_OVERHEAD
	ENABLE_INTS
	bl	.vsx_unavailable_exception
	b	.ret_from_except

	.align	7
	.globl	__end_handlers
__end_handlers:

/*
 * Return from an exception with minimal checks.
 * The caller is assumed to have done EXCEPTION_PROLOG_COMMON.
 * If interrupts have been enabled, or anything has been
 * done that might have changed the scheduling status of
 * any task or sent any task a signal, you should use
 * ret_from_except or ret_from_except_lite instead of this.
 */
fast_exc_return_irq:			/* restores irq state too */
	ld	r3,SOFTE(r1)
	TRACE_AND_RESTORE_IRQ(r3);
	ld	r12,_MSR(r1)
	rldicl	r4,r12,49,63		/* get MSR_EE to LSB */
	stb	r4,PACAHARDIRQEN(r13)	/* restore paca->hard_enabled */
	b	1f

	.globl	fast_exception_return
fast_exception_return:
	ld	r12,_MSR(r1)
1:	ld	r11,_NIP(r1)
	andi.	r3,r12,MSR_RI		/* check if RI is set */
	beq-	unrecov_fer

#ifdef CONFIG_VIRT_CPU_ACCOUNTING
	andi.	r3,r12,MSR_PR
	beq	2f
	ACCOUNT_CPU_USER_EXIT(r3, r4)
2:
#endif

	ld	r3,_CCR(r1)
	ld	r4,_LINK(r1)
	ld	r5,_CTR(r1)
	ld	r6,_XER(r1)
	mtcr	r3
	mtlr	r4
	mtctr	r5
	mtxer	r6
	REST_GPR(0, r1)
	REST_8GPRS(2, r1)

	mfmsr	r10
	rldicl	r10,r10,48,1		/* clear EE */
	rldicr	r10,r10,16,61		/* clear RI (LE is 0 already) */
	mtmsrd	r10,1

	mtspr	SPRN_SRR1,r12
	mtspr	SPRN_SRR0,r11
	REST_4GPRS(10, r1)
	ld	r1,GPR1(r1)
	rfid
	b	.	/* prevent speculative execution */

unrecov_fer:
	bl	.save_nvgprs
1:	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.unrecoverable_exception
	b	1b


/*
 * Hash table stuff
 */
	.align	7
_STATIC(do_hash_page)
	std	r3,_DAR(r1)
	std	r4,_DSISR(r1)

	andis.	r0,r4,0xa410		/* weird error? */
	bne-	handle_page_fault	/* if not, try to insert a HPTE */
	andis.  r0,r4,DSISR_DABRMATCH@h
	bne-    handle_dabr_fault

BEGIN_FTR_SECTION
	andis.	r0,r4,0x0020		/* Is it a segment table fault? */
	bne-	do_ste_alloc		/* If so handle it */
END_FTR_SECTION_IFCLR(CPU_FTR_SLB)

	clrrdi	r11,r1,THREAD_SHIFT
	lwz	r0,TI_PREEMPT(r11)	/* If we're in an "NMI" */
	andis.	r0,r0,NMI_MASK@h	/* (i.e. an irq when soft-disabled) */
	bne	77f			/* then don't call hash_page now */

	/*
	 * On iSeries, we soft-disable interrupts here, then
	 * hard-enable interrupts so that the hash_page code can spin on
	 * the hash_table_lock without problems on a shared processor.
	 */
	DISABLE_INTS

	/*
	 * Currently, trace_hardirqs_off() will be called by DISABLE_INTS
	 * and will clobber volatile registers when irq tracing is enabled
	 * so we need to reload them. It may be possible to be smarter here
	 * and move the irq tracing elsewhere but let's keep it simple for
	 * now
	 */
#ifdef CONFIG_TRACE_IRQFLAGS
	ld	r3,_DAR(r1)
	ld	r4,_DSISR(r1)
	ld	r5,_TRAP(r1)
	ld	r12,_MSR(r1)
	clrrdi	r5,r5,4
#endif /* CONFIG_TRACE_IRQFLAGS */
	/*
	 * We need to set the _PAGE_USER bit if MSR_PR is set or if we are
	 * accessing a userspace segment (even from the kernel). We assume
	 * kernel addresses always have the high bit set.
	 */
	rlwinm	r4,r4,32-25+9,31-9,31-9	/* DSISR_STORE -> _PAGE_RW */
	rotldi	r0,r3,15		/* Move high bit into MSR_PR posn */
	orc	r0,r12,r0		/* MSR_PR | ~high_bit */
	rlwimi	r4,r0,32-13,30,30	/* becomes _PAGE_USER access bit */
	ori	r4,r4,1			/* add _PAGE_PRESENT */
	rlwimi	r4,r5,22+2,31-2,31-2	/* Set _PAGE_EXEC if trap is 0x400 */

	/*
	 * r3 contains the faulting address
	 * r4 contains the required access permissions
	 * r5 contains the trap number
	 *
	 * at return r3 = 0 for success
	 */
	bl	.hash_page		/* build HPTE if possible */
	cmpdi	r3,0			/* see if hash_page succeeded */

BEGIN_FW_FTR_SECTION
	/*
	 * If we had interrupts soft-enabled at the point where the
	 * DSI/ISI occurred, and an interrupt came in during hash_page,
	 * handle it now.
	 * We jump to ret_from_except_lite rather than fast_exception_return
	 * because ret_from_except_lite will check for and handle pending
	 * interrupts if necessary.
	 */
	beq	13f
END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)

BEGIN_FW_FTR_SECTION
	/*
	 * Here we have interrupts hard-disabled, so it is sufficient
	 * to restore paca->{soft,hard}_enable and get out.
	 */
	beq	fast_exc_return_irq	/* Return from exception on success */
END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES)

	/* For a hash failure, we don't bother re-enabling interrupts */
	ble-	12f

	/*
	 * hash_page couldn't handle it, set soft interrupt enable back
	 * to what it was before the trap.  Note that .raw_local_irq_restore
	 * handles any interrupts pending at this point.
	 */
	ld	r3,SOFTE(r1)
	TRACE_AND_RESTORE_IRQ_PARTIAL(r3, 11f)
	bl	.raw_local_irq_restore
	b	11f

/* We have a data breakpoint exception - handle it */
handle_dabr_fault:
	ld      r4,_DAR(r1)
	ld      r5,_DSISR(r1)
	addi    r3,r1,STACK_FRAME_OVERHEAD
	bl      .do_dabr
	b       .ret_from_except_lite

/* Here we have a page fault that hash_page can't handle. */
handle_page_fault:
	ENABLE_INTS
11:	ld	r4,_DAR(r1)
	ld	r5,_DSISR(r1)
	addi	r3,r1,STACK_FRAME_OVERHEAD
	bl	.do_page_fault
	cmpdi	r3,0
	beq+	13f
	bl	.save_nvgprs
	mr	r5,r3
	addi	r3,r1,STACK_FRAME_OVERHEAD
	lwz	r4,_DAR(r1)
	bl	.bad_page_fault
	b	.ret_from_except

13:	b	.ret_from_except_lite

/* We have a page fault that hash_page could handle but HV refused
 * the PTE insertion
 */
12:	bl	.save_nvgprs
	mr	r5,r3
	addi	r3,r1,STACK_FRAME_OVERHEAD
	ld	r4,_DAR(r1)
	bl	.low_hash_fault
	b	.ret_from_except

/*
 * We come here as a result of a DSI at a point where we don't want
 * to call hash_page, such as when we are accessing memory (possibly
 * user memory) inside a PMU interrupt that occurred while interrupts
 * were soft-disabled.  We want to invoke the exception handler for
 * the access, or panic if there isn't a handler.
 */
77:	bl	.save_nvgprs
	mr	r4,r3
	addi	r3,r1,STACK_FRAME_OVERHEAD
	li	r5,SIGSEGV
	bl	.bad_page_fault
	b	.ret_from_except

	/* here we have a segment miss */
do_ste_alloc:
	bl	.ste_allocate		/* try to insert stab entry */
	cmpdi	r3,0
	bne-	handle_page_fault
	b	fast_exception_return

/*
 * r13 points to the PACA, r9 contains the saved CR,
 * r11 and r12 contain the saved SRR0 and SRR1.
 * r9 - r13 are saved in paca->exslb.
 * We assume we aren't going to take any exceptions during this procedure.
 * We assume (DAR >> 60) == 0xc.
 */
	.align	7
_GLOBAL(do_stab_bolted)
	stw	r9,PACA_EXSLB+EX_CCR(r13)	/* save CR in exc. frame */
	std	r11,PACA_EXSLB+EX_SRR0(r13)	/* save SRR0 in exc. frame */

	/* Hash to the primary group */
	ld	r10,PACASTABVIRT(r13)
	mfspr	r11,SPRN_DAR
	srdi	r11,r11,28
	rldimi	r10,r11,7,52	/* r10 = first ste of the group */

	/* Calculate VSID */
	/* This is a kernel address, so protovsid = ESID */
	ASM_VSID_SCRAMBLE(r11, r9, 256M)
	rldic	r9,r11,12,16	/* r9 = vsid << 12 */

	/* Search the primary group for a free entry */
1:	ld	r11,0(r10)	/* Test valid bit of the current ste	*/
	andi.	r11,r11,0x80
	beq	2f
	addi	r10,r10,16
	andi.	r11,r10,0x70
	bne	1b

	/* Stick for only searching the primary group for now.		*/
	/* At least for now, we use a very simple random castout scheme */
	/* Use the TB as a random number ;  OR in 1 to avoid entry 0	*/
	mftb	r11
	rldic	r11,r11,4,57	/* r11 = (r11 << 4) & 0x70 */
	ori	r11,r11,0x10

	/* r10 currently points to an ste one past the group of interest */
	/* make it point to the randomly selected entry			*/
	subi	r10,r10,128
	or 	r10,r10,r11	/* r10 is the entry to invalidate	*/

	isync			/* mark the entry invalid		*/
	ld	r11,0(r10)
	rldicl	r11,r11,56,1	/* clear the valid bit */
	rotldi	r11,r11,8
	std	r11,0(r10)
	sync

	clrrdi	r11,r11,28	/* Get the esid part of the ste		*/
	slbie	r11

2:	std	r9,8(r10)	/* Store the vsid part of the ste	*/
	eieio

	mfspr	r11,SPRN_DAR		/* Get the new esid			*/
	clrrdi	r11,r11,28	/* Permits a full 32b of ESID		*/
	ori	r11,r11,0x90	/* Turn on valid and kp			*/
	std	r11,0(r10)	/* Put new entry back into the stab	*/

	sync

	/* All done -- return from exception. */
	lwz	r9,PACA_EXSLB+EX_CCR(r13)	/* get saved CR */
	ld	r11,PACA_EXSLB+EX_SRR0(r13)	/* get saved SRR0 */

	andi.	r10,r12,MSR_RI
	beq-	unrecov_slb

	mtcrf	0x80,r9			/* restore CR */

	mfmsr	r10
	clrrdi	r10,r10,2
	mtmsrd	r10,1

	mtspr	SPRN_SRR0,r11
	mtspr	SPRN_SRR1,r12
	ld	r9,PACA_EXSLB+EX_R9(r13)
	ld	r10,PACA_EXSLB+EX_R10(r13)
	ld	r11,PACA_EXSLB+EX_R11(r13)
	ld	r12,PACA_EXSLB+EX_R12(r13)
	ld	r13,PACA_EXSLB+EX_R13(r13)
	rfid
	b	.	/* prevent speculative execution */

/*
 * Space for CPU0's segment table.
 *
 * On iSeries, the hypervisor must fill in at least one entry before
 * we get control (with relocate on).  The address is given to the hv
 * as a page number (see xLparMap below), so this must be at a
 * fixed address (the linker can't compute (u64)&initial_stab >>
 * PAGE_SHIFT).
 */
	. = STAB0_OFFSET	/* 0x6000 */
	.globl initial_stab
initial_stab:
	.space	4096

#ifdef CONFIG_PPC_PSERIES
/*
 * Data area reserved for FWNMI option.
 * This address (0x7000) is fixed by the RPA.
 */
	.= 0x7000
	.globl fwnmi_data_area
fwnmi_data_area:
#endif /* CONFIG_PPC_PSERIES */

	/* iSeries does not use the FWNMI stuff, so it is safe to put
	 * this here, even if we later allow kernels that will boot on
	 * both pSeries and iSeries */
#ifdef CONFIG_PPC_ISERIES
        . = LPARMAP_PHYS
	.globl xLparMap
xLparMap:
	.quad	HvEsidsToMap		/* xNumberEsids */
	.quad	HvRangesToMap		/* xNumberRanges */
	.quad	STAB0_PAGE		/* xSegmentTableOffs */
	.zero	40			/* xRsvd */
	/* xEsids (HvEsidsToMap entries of 2 quads) */
	.quad	PAGE_OFFSET_ESID	/* xKernelEsid */
	.quad	PAGE_OFFSET_VSID	/* xKernelVsid */
	.quad	VMALLOC_START_ESID	/* xKernelEsid */
	.quad	VMALLOC_START_VSID	/* xKernelVsid */
	/* xRanges (HvRangesToMap entries of 3 quads) */
	.quad	HvPagesToMap		/* xPages */
	.quad	0			/* xOffset */
	.quad	PAGE_OFFSET_VSID << (SID_SHIFT - HW_PAGE_SHIFT)	/* xVPN */

#endif /* CONFIG_PPC_ISERIES */

#ifdef CONFIG_PPC_PSERIES
        . = 0x8000
#endif /* CONFIG_PPC_PSERIES */