aboutsummaryrefslogtreecommitdiff
path: root/arch/avr32/kernel/entry-avr32b.S
blob: 050c006a7f0c6c11878af3cda2965d3c09782972 (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
/*
 * Copyright (C) 2004-2006 Atmel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

/*
 * This file contains the low-level entry-points into the kernel, that is,
 * exception handlers, debug trap handlers, interrupt handlers and the
 * system call handler.
 */
#include <linux/errno.h>

#include <asm/asm.h>
#include <asm/hardirq.h>
#include <asm/irq.h>
#include <asm/ocd.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/ptrace.h>
#include <asm/sysreg.h>
#include <asm/thread_info.h>
#include <asm/unistd.h>

#ifdef CONFIG_PREEMPT
# define preempt_stop		mask_interrupts
#else
# define preempt_stop
# define fault_resume_kernel	fault_restore_all
#endif

#define __MASK(x)	((1 << (x)) - 1)
#define IRQ_MASK	((__MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT) | \
			 (__MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT))

	.section .ex.text,"ax",@progbits
	.align	2
exception_vectors:
	bral	handle_critical
	.align	2
	bral	handle_critical
	.align	2
	bral	do_bus_error_write
	.align	2
	bral	do_bus_error_read
	.align	2
	bral	do_nmi_ll
	.align	2
	bral	handle_address_fault
	.align	2
	bral	handle_protection_fault
	.align	2
	bral	handle_debug
	.align	2
	bral	do_illegal_opcode_ll
	.align	2
	bral	do_illegal_opcode_ll
	.align	2
	bral	do_illegal_opcode_ll
	.align	2
	bral	do_fpe_ll
	.align	2
	bral	do_illegal_opcode_ll
	.align	2
	bral	handle_address_fault
	.align	2
	bral	handle_address_fault
	.align	2
	bral	handle_protection_fault
	.align	2
	bral	handle_protection_fault
	.align	2
	bral	do_dtlb_modified

	/*
	 * r0 :	PGD/PT/PTE
	 * r1 : Offending address
	 * r2 : Scratch register
	 * r3 : Cause (5, 12 or 13)
	 */
#define	tlbmiss_save	pushm	r0-r3
#define tlbmiss_restore	popm	r0-r3

	.org	0x50
	.global	itlb_miss
itlb_miss:
	tlbmiss_save
	rjmp	tlb_miss_common

	.org	0x60
dtlb_miss_read:
	tlbmiss_save
	rjmp	tlb_miss_common

	.org	0x70
dtlb_miss_write:
	tlbmiss_save

	.global	tlb_miss_common
	.align	2
tlb_miss_common:
	mfsr	r0, SYSREG_TLBEAR
	mfsr	r1, SYSREG_PTBR

	/* Is it the vmalloc space? */
	bld	r0, 31
	brcs	handle_vmalloc_miss

	/* First level lookup */
pgtbl_lookup:
	lsr	r2, r0, PGDIR_SHIFT
	ld.w	r3, r1[r2 << 2]
	bfextu	r1, r0, PAGE_SHIFT, PGDIR_SHIFT - PAGE_SHIFT
	bld	r3, _PAGE_BIT_PRESENT
	brcc	page_table_not_present

	/* Translate to virtual address in P1. */
	andl	r3, 0xf000
	sbr	r3, 31

	/* Second level lookup */
	ld.w	r2, r3[r1 << 2]
	mfsr	r0, SYSREG_TLBARLO
	bld	r2, _PAGE_BIT_PRESENT
	brcc	page_not_present

	/* Mark the page as accessed */
	sbr	r2, _PAGE_BIT_ACCESSED
	st.w	r3[r1 << 2], r2

	/* Drop software flags */
	andl	r2, _PAGE_FLAGS_HARDWARE_MASK & 0xffff
	mtsr	SYSREG_TLBELO, r2

	/* Figure out which entry we want to replace */
	mfsr	r1, SYSREG_MMUCR
	clz	r2, r0
	brcc	1f
	mov	r3, -1			/* All entries have been accessed, */
	mov	r2, 0			/* so start at 0 */
	mtsr	SYSREG_TLBARLO, r3	/* and reset TLBAR */

1:	bfins	r1, r2, SYSREG_DRP_OFFSET, SYSREG_DRP_SIZE
	mtsr	SYSREG_MMUCR, r1
	tlbw

	tlbmiss_restore
	rete

handle_vmalloc_miss:
	/* Simply do the lookup in init's page table */
	mov	r1, lo(swapper_pg_dir)
	orh	r1, hi(swapper_pg_dir)
	rjmp	pgtbl_lookup


	/* ---                    System Call                    --- */

	.org	0x100
system_call:
#ifdef CONFIG_PREEMPT
	mask_interrupts
#endif
	pushm	r12		/* r12_orig */
	stmts	--sp, r0-lr

	mfsr	r0, SYSREG_RAR_SUP
	mfsr	r1, SYSREG_RSR_SUP
#ifdef CONFIG_PREEMPT
	unmask_interrupts
#endif
	zero_fp
	stm	--sp, r0-r1

	/* check for syscall tracing */
	get_thread_info r0
	ld.w	r1, r0[TI_flags]
	bld	r1, TIF_SYSCALL_TRACE
	brcs	syscall_trace_enter

syscall_trace_cont:
	cp.w	r8, NR_syscalls
	brhs	syscall_badsys

	lddpc   lr, syscall_table_addr
	ld.w    lr, lr[r8 << 2]
	mov	r8, r5		/* 5th argument (6th is pushed by stub) */
	icall   lr

	.global	syscall_return
syscall_return:
	get_thread_info r0
	mask_interrupts		/* make sure we don't miss an interrupt
				   setting need_resched or sigpending
				   between sampling and the rets */

	/* Store the return value so that the correct value is loaded below */
	stdsp   sp[REG_R12], r12

	ld.w	r1, r0[TI_flags]
	andl	r1, _TIF_ALLWORK_MASK, COH
	brne	syscall_exit_work

syscall_exit_cont:
	popm	r8-r9
	mtsr	SYSREG_RAR_SUP, r8
	mtsr	SYSREG_RSR_SUP, r9
	ldmts	sp++, r0-lr
	sub	sp, -4		/* r12_orig */
	rets

	.align	2
syscall_table_addr:
	.long   sys_call_table

syscall_badsys:
	mov	r12, -ENOSYS
	rjmp	syscall_return

	.global ret_from_fork
ret_from_fork:
	rcall   schedule_tail

	/* check for syscall tracing */
	get_thread_info r0
	ld.w	r1, r0[TI_flags]
	andl	r1, _TIF_ALLWORK_MASK, COH
	brne	syscall_exit_work
	rjmp    syscall_exit_cont

syscall_trace_enter:
	pushm	r8-r12
	rcall	syscall_trace
	popm	r8-r12
	rjmp	syscall_trace_cont

syscall_exit_work:
	bld	r1, TIF_SYSCALL_TRACE
	brcc	1f
	unmask_interrupts
	rcall	syscall_trace
	mask_interrupts
	ld.w	r1, r0[TI_flags]

1:	bld	r1, TIF_NEED_RESCHED
	brcc	2f
	unmask_interrupts
	rcall	schedule
	mask_interrupts
	ld.w	r1, r0[TI_flags]
	rjmp	1b

2:	mov	r2, _TIF_SIGPENDING | _TIF_RESTORE_SIGMASK
	tst	r1, r2
	breq	3f
	unmask_interrupts
	mov	r12, sp
	mov	r11, r0
	rcall	do_notify_resume
	mask_interrupts
	ld.w	r1, r0[TI_flags]
	rjmp	1b

3:	bld	r1, TIF_BREAKPOINT
	brcc	syscall_exit_cont
	rjmp	enter_monitor_mode

	/* The slow path of the TLB miss handler */
page_table_not_present:
page_not_present:
	tlbmiss_restore
	sub	sp, 4
	stmts	--sp, r0-lr
	rcall	save_full_context_ex
	mfsr	r12, SYSREG_ECR
	mov	r11, sp
	rcall	do_page_fault
	rjmp	ret_from_exception

	/* This function expects to find offending PC in SYSREG_RAR_EX */
	.type	save_full_context_ex, @function
	.align	2
save_full_context_ex:
	mfsr	r11, SYSREG_RAR_EX
	sub	r9, pc, . - debug_trampoline
	mfsr	r8, SYSREG_RSR_EX
	cp.w	r9, r11
	breq	3f
	mov	r12, r8
	andh	r8, (MODE_MASK >> 16), COH
	brne	2f

1:	pushm	r11, r12	/* PC and SR */
	unmask_exceptions
	ret	r12

2:	sub	r10, sp, -(FRAME_SIZE_FULL - REG_LR)
	stdsp	sp[4], r10	/* replace saved SP */
	rjmp	1b

	/*
	 * The debug handler set up a trampoline to make us
	 * automatically enter monitor mode upon return, but since
	 * we're saving the full context, we must assume that the
	 * exception handler might want to alter the return address
	 * and/or status register. So we need to restore the original
	 * context and enter monitor mode manually after the exception
	 * has been handled.
	 */
3:	get_thread_info r8
	ld.w	r11, r8[TI_rar_saved]
	ld.w	r12, r8[TI_rsr_saved]
	rjmp	1b
	.size	save_full_context_ex, . - save_full_context_ex

	/* Low-level exception handlers */
handle_critical:
	sub	sp, 4
	stmts	--sp, r0-lr
	rcall	save_full_context_ex
	mfsr	r12, SYSREG_ECR
	mov	r11, sp
	rcall	do_critical_exception

	/* We should never get here... */
bad_return:
	sub	r12, pc, (. - 1f)
	bral	panic
	.align	2
1:	.asciz	"Return from critical exception!"

	.align	1
do_bus_error_write:
	sub	sp, 4
	stmts	--sp, r0-lr
	rcall	save_full_context_ex
	mov	r11, 1
	rjmp	1f

do_bus_error_read:
	sub	sp, 4
	stmts	--sp, r0-lr
	rcall	save_full_context_ex
	mov	r11, 0
1:	mfsr	r12, SYSREG_BEAR
	mov	r10, sp
	rcall	do_bus_error
	rjmp	ret_from_exception

	.align	1
do_nmi_ll:
	sub	sp, 4
	stmts	--sp, r0-lr
	mfsr	r9, SYSREG_RSR_NMI
	mfsr	r8, SYSREG_RAR_NMI
	bfextu	r0, r9, MODE_SHIFT, 3
	brne	2f

1:	pushm	r8, r9	/* PC and SR */
	mfsr	r12, SYSREG_ECR
	mov	r11, sp
	rcall	do_nmi
	popm	r8-r9
	mtsr	SYSREG_RAR_NMI, r8
	tst	r0, r0
	mtsr	SYSREG_RSR_NMI, r9
	brne	3f

	ldmts	sp++, r0-lr
	sub	sp, -4		/* skip r12_orig */
	rete

2:	sub	r10, sp, -(FRAME_SIZE_FULL - REG_LR)
	stdsp	sp[4], r10	/* replace saved SP */
	rjmp	1b

3:	popm	lr
	sub	sp, -4		/* skip sp */
	popm	r0-r12
	sub	sp, -4		/* skip r12_orig */
	rete

handle_address_fault:
	sub	sp, 4
	stmts	--sp, r0-lr
	rcall	save_full_context_ex
	mfsr	r12, SYSREG_ECR
	mov	r11, sp
	rcall	do_address_exception
	rjmp	ret_from_exception

handle_protection_fault:
	sub	sp, 4
	stmts	--sp, r0-lr
	rcall	save_full_context_ex
	mfsr	r12, SYSREG_ECR
	mov	r11, sp
	rcall	do_page_fault
	rjmp	ret_from_exception

	.align	1
do_illegal_opcode_ll:
	sub	sp, 4
	stmts	--sp, r0-lr
	rcall	save_full_context_ex
	mfsr	r12, SYSREG_ECR
	mov	r11, sp
	rcall	do_illegal_opcode
	rjmp	ret_from_exception

do_dtlb_modified:
	pushm	r0-r3
	mfsr	r1, SYSREG_TLBEAR
	mfsr	r0, SYSREG_PTBR
	lsr	r2, r1, PGDIR_SHIFT
	ld.w	r0, r0[r2 << 2]
	lsl	r1, (32 - PGDIR_SHIFT)
	lsr	r1, (32 - PGDIR_SHIFT) + PAGE_SHIFT

	/* Translate to virtual address in P1 */
	andl	r0, 0xf000
	sbr	r0, 31
	add	r2, r0, r1 << 2
	ld.w	r3, r2[0]
	sbr	r3, _PAGE_BIT_DIRTY
	mov	r0, r3
	st.w	r2[0], r3

	/* The page table is up-to-date. Update the TLB entry as well */
	andl	r0, lo(_PAGE_FLAGS_HARDWARE_MASK)
	mtsr	SYSREG_TLBELO, r0

	/* MMUCR[DRP] is updated automatically, so let's go... */
	tlbw

	popm	r0-r3
	rete

do_fpe_ll:
	sub	sp, 4
	stmts	--sp, r0-lr
	rcall	save_full_context_ex
	unmask_interrupts
	mov	r12, 26
	mov	r11, sp
	rcall	do_fpe
	rjmp	ret_from_exception

ret_from_exception:
	mask_interrupts
	lddsp	r4, sp[REG_SR]

	andh	r4, (MODE_MASK >> 16), COH
	brne	fault_resume_kernel

	get_thread_info r0
	ld.w	r1, r0[TI_flags]
	andl	r1, _TIF_WORK_MASK, COH
	brne	fault_exit_work

fault_resume_user:
	popm	r8-r9
	mask_exceptions
	mtsr	SYSREG_RAR_EX, r8
	mtsr	SYSREG_RSR_EX, r9
	ldmts	sp++, r0-lr
	sub	sp, -4
	rete

fault_resume_kernel:
#ifdef CONFIG_PREEMPT
	get_thread_info	r0
	ld.w	r2, r0[TI_preempt_count]
	cp.w	r2, 0
	brne	1f
	ld.w	r1, r0[TI_flags]
	bld	r1, TIF_NEED_RESCHED
	brcc	1f
	lddsp	r4, sp[REG_SR]
	bld	r4, SYSREG_GM_OFFSET
	brcs	1f
	rcall	preempt_schedule_irq
1:
#endif

	popm	r8-r9
	mask_exceptions
	mfsr	r1, SYSREG_SR
	mtsr	SYSREG_RAR_EX, r8
	mtsr	SYSREG_RSR_EX, r9
	popm	lr
	sub	sp, -4		/* ignore SP */
	popm	r0-r12
	sub	sp, -4		/* ignore r12_orig */
	rete

irq_exit_work:
	/* Switch to exception mode so that we can share the same code. */
	mfsr	r8, SYSREG_SR
	cbr	r8, SYSREG_M0_OFFSET
	orh	r8, hi(SYSREG_BIT(M1) | SYSREG_BIT(M2))
	mtsr	SYSREG_SR, r8
	sub	pc, -2
	get_thread_info r0
	ld.w	r1, r0[TI_flags]

fault_exit_work:
	bld	r1, TIF_NEED_RESCHED
	brcc	1f
	unmask_interrupts
	rcall	schedule
	mask_interrupts
	ld.w	r1, r0[TI_flags]
	rjmp	fault_exit_work

1:	mov	r2, _TIF_SIGPENDING | _TIF_RESTORE_SIGMASK
	tst	r1, r2
	breq	2f
	unmask_interrupts
	mov	r12, sp
	mov	r11, r0
	rcall	do_notify_resume
	mask_interrupts
	ld.w	r1, r0[TI_flags]
	rjmp	fault_exit_work

2:	bld	r1, TIF_BREAKPOINT
	brcc	fault_resume_user
	rjmp	enter_monitor_mode

	.section .kprobes.text, "ax", @progbits
	.type	handle_debug, @function
handle_debug:
	sub	sp, 4		/* r12_orig */
	stmts	--sp, r0-lr
	mfsr	r8, SYSREG_RAR_DBG
	mfsr	r9, SYSREG_RSR_DBG
	unmask_exceptions
	pushm	r8-r9
	bfextu	r9, r9, SYSREG_MODE_OFFSET, SYSREG_MODE_SIZE
	brne	debug_fixup_regs

.Ldebug_fixup_cont:
#ifdef CONFIG_TRACE_IRQFLAGS
	rcall	trace_hardirqs_off
#endif
	mov	r12, sp
	rcall	do_debug
	mov	sp, r12

	lddsp	r2, sp[REG_SR]
	bfextu	r3, r2, SYSREG_MODE_OFFSET, SYSREG_MODE_SIZE
	brne	debug_resume_kernel

	get_thread_info r0
	ld.w	r1, r0[TI_flags]
	mov	r2, _TIF_DBGWORK_MASK
	tst	r1, r2
	brne	debug_exit_work

	bld	r1, TIF_SINGLE_STEP
	brcc	1f
	mfdr	r4, OCD_DC
	sbr	r4, OCD_DC_SS_BIT
	mtdr	OCD_DC, r4

1:	popm	r10,r11
	mask_exceptions
	mtsr	SYSREG_RSR_DBG, r11
	mtsr	SYSREG_RAR_DBG, r10
#ifdef CONFIG_TRACE_IRQFLAGS
	rcall	trace_hardirqs_on
1:
#endif
	ldmts	sp++, r0-lr
	sub	sp, -4
	retd
	.size	handle_debug, . - handle_debug

	/* Mode of the trapped context is in r9 */
	.type	debug_fixup_regs, @function
debug_fixup_regs:
	mfsr	r8, SYSREG_SR
	mov	r10, r8
	bfins	r8, r9, SYSREG_MODE_OFFSET, SYSREG_MODE_SIZE
	mtsr	SYSREG_SR, r8
	sub	pc, -2
	stdsp	sp[REG_LR], lr
	mtsr	SYSREG_SR, r10
	sub	pc, -2
	sub	r8, sp, -FRAME_SIZE_FULL
	stdsp	sp[REG_SP], r8
	rjmp	.Ldebug_fixup_cont
	.size	debug_fixup_regs, . - debug_fixup_regs

	.type	debug_resume_kernel, @function
debug_resume_kernel:
	mask_exceptions
	popm	r10, r11
	mtsr	SYSREG_RAR_DBG, r10
	mtsr	SYSREG_RSR_DBG, r11
#ifdef CONFIG_TRACE_IRQFLAGS
	bld	r11, SYSREG_GM_OFFSET
	brcc	1f
	rcall	trace_hardirqs_on
1:
#endif
	mfsr	r2, SYSREG_SR
	mov	r1, r2
	bfins	r2, r3, SYSREG_MODE_OFFSET, SYSREG_MODE_SIZE
	mtsr	SYSREG_SR, r2
	sub	pc, -2
	popm	lr
	mtsr	SYSREG_SR, r1
	sub	pc, -2
	sub	sp, -4		/* skip SP */
	popm	r0-r12
	sub	sp, -4
	retd
	.size	debug_resume_kernel, . - debug_resume_kernel

	.type	debug_exit_work, @function
debug_exit_work:
	/*
	 * We must return from Monitor Mode using a retd, and we must
	 * not schedule since that involves the D bit in SR getting
	 * cleared by something other than the debug hardware. This
	 * may cause undefined behaviour according to the Architecture
	 * manual.
	 *
	 * So we fix up the return address and status and return to a
	 * stub below in Exception mode. From there, we can follow the
	 * normal exception return path.
	 *
	 * The real return address and status registers are stored on
	 * the stack in the way the exception return path understands,
	 * so no need to fix anything up there.
	 */
	sub	r8, pc, . - fault_exit_work
	mtsr	SYSREG_RAR_DBG, r8
	mov	r9, 0
	orh	r9, hi(SR_EM | SR_GM | MODE_EXCEPTION)
	mtsr	SYSREG_RSR_DBG, r9
	sub	pc, -2
	retd
	.size	debug_exit_work, . - debug_exit_work

	.set	rsr_int0,	SYSREG_RSR_INT0
	.set	rsr_int1,	SYSREG_RSR_INT1
	.set	rsr_int2,	SYSREG_RSR_INT2
	.set	rsr_int3,	SYSREG_RSR_INT3
	.set	rar_int0,	SYSREG_RAR_INT0
	.set	rar_int1,	SYSREG_RAR_INT1
	.set	rar_int2,	SYSREG_RAR_INT2
	.set	rar_int3,	SYSREG_RAR_INT3

	.macro	IRQ_LEVEL level
	.type	irq_level\level, @function
irq_level\level:
	sub	sp, 4		/* r12_orig */
	stmts	--sp,r0-lr
	mfsr	r8, rar_int\level
	mfsr	r9, rsr_int\level

#ifdef CONFIG_PREEMPT
	sub	r11, pc, (. - system_call)
	cp.w	r11, r8
	breq	4f
#endif

	pushm	r8-r9

	mov	r11, sp
	mov	r12, \level

	rcall	do_IRQ

	lddsp	r4, sp[REG_SR]
	bfextu	r4, r4, SYSREG_M0_OFFSET, 3
	cp.w	r4, MODE_SUPERVISOR >> SYSREG_M0_OFFSET
	breq	2f
	cp.w	r4, MODE_USER >> SYSREG_M0_OFFSET
#ifdef CONFIG_PREEMPT
	brne	3f
#else
	brne	1f
#endif

	get_thread_info	r0
	ld.w	r1, r0[TI_flags]
	andl	r1, _TIF_WORK_MASK, COH
	brne	irq_exit_work

1:
#ifdef CONFIG_TRACE_IRQFLAGS
	rcall	trace_hardirqs_on
#endif
	popm	r8-r9
	mtsr	rar_int\level, r8
	mtsr	rsr_int\level, r9
	ldmts	sp++,r0-lr
	sub	sp, -4		/* ignore r12_orig */
	rete

#ifdef CONFIG_PREEMPT
4:	mask_interrupts
	mfsr	r8, rsr_int\level
	sbr	r8, 16
	mtsr	rsr_int\level, r8
	ldmts	sp++, r0-lr
	sub	sp, -4		/* ignore r12_orig */
	rete
#endif

2:	get_thread_info	r0
	ld.w	r1, r0[TI_flags]
	bld	r1, TIF_CPU_GOING_TO_SLEEP
#ifdef CONFIG_PREEMPT
	brcc	3f
#else
	brcc	1b
#endif
	sub	r1, pc, . - cpu_idle_skip_sleep
	stdsp	sp[REG_PC], r1
#ifdef CONFIG_PREEMPT
3:	get_thread_info r0
	ld.w	r2, r0[TI_preempt_count]
	cp.w	r2, 0
	brne	1b
	ld.w	r1, r0[TI_flags]
	bld	r1, TIF_NEED_RESCHED
	brcc	1b
	lddsp	r4, sp[REG_SR]
	bld	r4, SYSREG_GM_OFFSET
	brcs	1b
	rcall	preempt_schedule_irq
#endif
	rjmp	1b
	.endm

	.section .irq.text,"ax",@progbits

	.global	irq_level0
	.global	irq_level1
	.global	irq_level2
	.global	irq_level3
	IRQ_LEVEL 0
	IRQ_LEVEL 1
	IRQ_LEVEL 2
	IRQ_LEVEL 3

	.section .kprobes.text, "ax", @progbits
	.type	enter_monitor_mode, @function
enter_monitor_mode:
	/*
	 * We need to enter monitor mode to do a single step. The
	 * monitor code will alter the return address so that we
	 * return directly to the user instead of returning here.
	 */
	breakpoint
	rjmp	breakpoint_failed

	.size	enter_monitor_mode, . - enter_monitor_mode

	.type	debug_trampoline, @function
	.global	debug_trampoline
debug_trampoline:
	/*
	 * Save the registers on the stack so that the monitor code
	 * can find them easily.
	 */
	sub	sp, 4		/* r12_orig */
	stmts	--sp, r0-lr
	get_thread_info	r0
	ld.w	r8, r0[TI_rar_saved]
	ld.w	r9, r0[TI_rsr_saved]
	pushm	r8-r9

	/*
	 * The monitor code will alter the return address so we don't
	 * return here.
	 */
	breakpoint
	rjmp	breakpoint_failed
	.size	debug_trampoline, . - debug_trampoline

	.type breakpoint_failed, @function
breakpoint_failed:
	/*
	 * Something went wrong. Perhaps the debug hardware isn't
	 * enabled?
	 */
	lda.w	r12, msg_breakpoint_failed
	mov	r11, sp
	mov	r10, 9		/* SIGKILL */
	call	die
1:	rjmp	1b

msg_breakpoint_failed:
	.asciz	"Failed to enter Debug Mode"