aboutsummaryrefslogtreecommitdiff
path: root/arch/m32r/kernel/entry.S
blob: 225412bc227e690bcb313743dd16f58fca5c4115 (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
/*
 *  linux/arch/m32r/kernel/entry.S
 *
 *  Copyright (c) 2001, 2002  Hirokazu Takata, Hitoshi Yamamoto, H. Kondo
 *  Copyright (c) 2003  Hitoshi Yamamoto
 *  Copyright (c) 2004  Hirokazu Takata <takata at linux-m32r.org>
 *
 *  Taken from i386 version.
 *    Copyright (C) 1991, 1992  Linus Torvalds
 */

/*
 * entry.S contains the system-call and fault low-level handling routines.
 * This also contains the timer-interrupt handler, as well as all interrupts
 * and faults that can result in a task-switch.
 *
 * NOTE: This code handles signal-recognition, which happens every time
 * after a timer-interrupt and after each system call.
 *
 * Stack layout in 'ret_from_system_call':
 * 	ptrace needs to have all regs on the stack.
 *	if the order here is changed, it needs to be
 *	updated in fork.c:copy_thread, signal.c:do_signal,
 *	ptrace.c and ptrace.h
 *
 * M32R/M32Rx/M32R2
 *       @(sp)      - r4
 *       @(0x04,sp) - r5
 *       @(0x08,sp) - r6
 *       @(0x0c,sp) - *pt_regs
 *       @(0x10,sp) - r0
 *       @(0x14,sp) - r1
 *       @(0x18,sp) - r2
 *       @(0x1c,sp) - r3
 *       @(0x20,sp) - r7
 *       @(0x24,sp) - r8
 *       @(0x28,sp) - r9
 *       @(0x2c,sp) - r10
 *       @(0x30,sp) - r11
 *       @(0x34,sp) - r12
 *       @(0x38,sp) - syscall_nr
 *       @(0x3c,sp) - acc0h
 *       @(0x40,sp) - acc0l
 *       @(0x44,sp) - acc1h		; ISA_DSP_LEVEL2 only
 *       @(0x48,sp) - acc1l		; ISA_DSP_LEVEL2 only
 *       @(0x4c,sp) - psw
 *       @(0x50,sp) - bpc
 *       @(0x54,sp) - bbpsw
 *       @(0x58,sp) - bbpc
 *       @(0x5c,sp) - spu (cr3)
 *       @(0x60,sp) - fp (r13)
 *       @(0x64,sp) - lr (r14)
 *       @(0x68,sp) - spi (cr2)
 *       @(0x6c,sp) - orig_r0
 */

#include <linux/linkage.h>
#include <asm/irq.h>
#include <asm/unistd.h>
#include <asm/assembler.h>
#include <asm/thread_info.h>
#include <asm/errno.h>
#include <asm/segment.h>
#include <asm/smp.h>
#include <asm/page.h>
#include <asm/m32r.h>
#include <asm/mmu_context.h>

#if !defined(CONFIG_MMU)
#define sys_madvise		sys_ni_syscall
#define sys_readahead		sys_ni_syscall
#define sys_mprotect		sys_ni_syscall
#define sys_msync		sys_ni_syscall
#define sys_mlock		sys_ni_syscall
#define sys_munlock		sys_ni_syscall
#define sys_mlockall		sys_ni_syscall
#define sys_munlockall		sys_ni_syscall
#define sys_mremap		sys_ni_syscall
#define sys_mincore		sys_ni_syscall
#define sys_remap_file_pages	sys_ni_syscall
#endif /* CONFIG_MMU */

#define R4(reg)			@reg
#define R5(reg)			@(0x04,reg)
#define R6(reg)			@(0x08,reg)
#define PTREGS(reg)		@(0x0C,reg)
#define R0(reg)			@(0x10,reg)
#define R1(reg)			@(0x14,reg)
#define R2(reg)			@(0x18,reg)
#define R3(reg)			@(0x1C,reg)
#define R7(reg)			@(0x20,reg)
#define R8(reg)			@(0x24,reg)
#define R9(reg)			@(0x28,reg)
#define R10(reg)		@(0x2C,reg)
#define R11(reg)		@(0x30,reg)
#define R12(reg)		@(0x34,reg)
#define SYSCALL_NR(reg)		@(0x38,reg)
#define ACC0H(reg)		@(0x3C,reg)
#define ACC0L(reg)		@(0x40,reg)
#define ACC1H(reg)		@(0x44,reg)
#define ACC1L(reg)		@(0x48,reg)
#define PSW(reg)		@(0x4C,reg)
#define BPC(reg)		@(0x50,reg)
#define BBPSW(reg)		@(0x54,reg)
#define BBPC(reg)		@(0x58,reg)
#define SPU(reg)		@(0x5C,reg)
#define FP(reg)			@(0x60,reg)  /* FP = R13 */
#define LR(reg)			@(0x64,reg)
#define SP(reg)			@(0x68,reg)
#define ORIG_R0(reg)		@(0x6C,reg)

#define nr_syscalls ((syscall_table_size)/4)

#ifdef CONFIG_PREEMPT
#define preempt_stop(x)		DISABLE_INTERRUPTS(x)
#else
#define preempt_stop(x)
#define resume_kernel		restore_all
#endif

/* how to get the thread information struct from ASM */
#define GET_THREAD_INFO(reg)	GET_THREAD_INFO reg
	.macro GET_THREAD_INFO reg
	ldi	\reg, #-THREAD_SIZE
	and	\reg, sp
	.endm

ENTRY(ret_from_fork)
	pop	r0
	bl	schedule_tail
	GET_THREAD_INFO(r8)
	bra	syscall_exit

/*
 * Return to user mode is not as complex as all this looks,
 * but we want the default path for a system call return to
 * go as quickly as possible which is why some of this is
 * less clear than it otherwise should be.
 */

	; userspace resumption stub bypassing syscall exit tracing
	ALIGN
ret_from_exception:
	preempt_stop(r4)
ret_from_intr:
	ld	r4, PSW(sp)
#ifdef CONFIG_ISA_M32R2
	and3	r4, r4, #0x8800		; check BSM and BPM bits
#else
	and3	r4, r4, #0x8000		; check BSM bit
#endif
	beqz	r4, resume_kernel
resume_userspace:
	DISABLE_INTERRUPTS(r4)		; make sure we don't miss an interrupt
					; setting need_resched or sigpending
					; between sampling and the iret
	GET_THREAD_INFO(r8)
	ld	r9, @(TI_FLAGS, r8)
	and3	r4, r9, #_TIF_WORK_MASK	; is there any work to be done on
					; int/exception return?
	bnez	r4, work_pending
	bra	restore_all

#ifdef CONFIG_PREEMPT
ENTRY(resume_kernel)
	GET_THREAD_INFO(r8)
	ld	r9, @(TI_PRE_COUNT, r8)	; non-zero preempt_count ?
	bnez	r9, restore_all
need_resched:
	ld	r9, @(TI_FLAGS, r8)	; need_resched set ?
	and3	r4, r9, #_TIF_NEED_RESCHED
	beqz	r4, restore_all
	ld	r4, PSW(sp)		; interrupts off (exception path) ?
	and3	r4, r4, #0x4000
	beqz	r4, restore_all
	LDIMM	(r4, PREEMPT_ACTIVE)
	st	r4, @(TI_PRE_COUNT, r8)
	ENABLE_INTERRUPTS(r4)
	bl	schedule
	ldi	r4, #0
	st	r4, @(TI_PRE_COUNT, r8)
	DISABLE_INTERRUPTS(r4)
	bra	need_resched
#endif

	; system call handler stub
ENTRY(system_call)
	SWITCH_TO_KERNEL_STACK
	SAVE_ALL
	ENABLE_INTERRUPTS(r4)		; Enable interrupt
	st	sp, PTREGS(sp)		; implicit pt_regs parameter
	cmpui	r7, #NR_syscalls
	bnc	syscall_badsys
	st	r7, SYSCALL_NR(sp)	; syscall_nr
					; system call tracing in operation
	GET_THREAD_INFO(r8)
	ld	r9, @(TI_FLAGS, r8)
	and3	r4, r9, #_TIF_SYSCALL_TRACE
	bnez	r4, syscall_trace_entry
syscall_call:
	slli	r7, #2			; table jump for the system call
	LDIMM	(r4, sys_call_table)
	add	r7, r4
	ld	r7, @r7
	jl	r7			; execute system call
	st	r0, R0(sp)		; save the return value
syscall_exit:
	DISABLE_INTERRUPTS(r4)		; make sure we don't miss an interrupt
					; setting need_resched or sigpending
					; between sampling and the iret
	ld	r9, @(TI_FLAGS, r8)
	and3	r4, r9, #_TIF_ALLWORK_MASK	; current->work
	bnez	r4, syscall_exit_work
restore_all:
	RESTORE_ALL

	# perform work that needs to be done immediately before resumption
	# r9 : flags
	ALIGN
work_pending:
	and3	r4, r9, #_TIF_NEED_RESCHED
	beqz	r4, work_notifysig
work_resched:
	bl	schedule
	DISABLE_INTERRUPTS(r4)		; make sure we don't miss an interrupt
					; setting need_resched or sigpending
					; between sampling and the iret
	ld	r9, @(TI_FLAGS, r8)
	and3	r4, r9, #_TIF_WORK_MASK	; is there any work to be done other
					; than syscall tracing?
	beqz	r4, restore_all
	and3	r4, r4, #_TIF_NEED_RESCHED
	bnez	r4, work_resched

work_notifysig:				; deal with pending signals and
					; notify-resume requests
	mv	r0, sp			; arg1 : struct pt_regs *regs
	mv	r1, r9			; arg2 : __u32 thread_info_flags
	bl	do_notify_resume
	bra	resume_userspace

	; perform syscall exit tracing
	ALIGN
syscall_trace_entry:
	ldi	r4, #-ENOSYS
	st	r4, R0(sp)
	bl	do_syscall_trace
	ld	r0, ORIG_R0(sp)
	ld	r1, R1(sp)
	ld	r2, R2(sp)
	ld	r3, R3(sp)
	ld	r4, R4(sp)
	ld	r5, R5(sp)
	ld	r6, R6(sp)
	ld	r7, SYSCALL_NR(sp)
	cmpui	r7, #NR_syscalls
	bc	syscall_call
	bra	syscall_exit

	; perform syscall exit tracing
	ALIGN
syscall_exit_work:
	ld	r9, @(TI_FLAGS, r8)
	and3	r4, r9, #_TIF_SYSCALL_TRACE
	beqz	r4, work_pending
	ENABLE_INTERRUPTS(r4)		; could let do_syscall_trace() call
					; schedule() instead
	bl	do_syscall_trace
	bra	resume_userspace

	ALIGN
syscall_fault:
	SAVE_ALL
	GET_THREAD_INFO(r8)
	ldi	r4, #-EFAULT
	st	r4, R0(sp)
	bra	resume_userspace

	ALIGN
syscall_badsys:
	ldi	r4, #-ENOSYS
	st	r4, R0(sp)
	bra	resume_userspace

	.global	eit_vector

	.equ ei_vec_table, eit_vector + 0x0200

/*
 * EI handler routine
 */
ENTRY(ei_handler)
#if defined(CONFIG_CHIP_M32700)
	; WORKAROUND: force to clear SM bit and use the kernel stack (SPI).
	SWITCH_TO_KERNEL_STACK
#endif
	SAVE_ALL
	mv	r1, sp			; arg1(regs)
	; get ICU status
	seth	r0, #shigh(M32R_ICU_ISTS_ADDR)
	ld	r0, @(low(M32R_ICU_ISTS_ADDR),r0)
	push	r0
#if defined(CONFIG_SMP)
	/*
	 * If IRQ == 0      --> Nothing to do,  Not write IMASK
	 * If IRQ == IPI    --> Do IPI handler, Not write IMASK
	 * If IRQ != 0, IPI --> Do do_IRQ(),    Write IMASK
	 */
	slli	r0, #4
	srli	r0, #24			; r0(irq_num<<2)
	;; IRQ exist check
#if defined(CONFIG_CHIP_M32700)
	/* WORKAROUND: IMASK bug M32700-TS1, TS2 chip. */
	bnez	r0, 0f
	ld24	r14, #0x00070000
	seth	r0, #shigh(M32R_ICU_IMASK_ADDR)
	st	r14, @(low(M32R_ICU_IMASK_ADDR),r0)
	bra	1f
	.fillinsn
0:
#endif /* CONFIG_CHIP_M32700 */
	beqz	r0, 1f			; if (!irq_num) goto exit
	;; IPI check
	cmpi	r0, #(M32R_IRQ_IPI0<<2)	; ISN < IPI0 check
	bc	2f
	cmpi	r0, #((M32R_IRQ_IPI7+1)<<2)	; ISN > IPI7 check
	bnc	2f
	LDIMM	(r2, ei_vec_table)
	add	r2, r0
	ld	r2, @r2
	beqz	r2, 1f			; if (no IPI handler) goto exit
	mv	r0, r1			; arg0(regs)
	jl	r2
	.fillinsn
1:
	addi	sp, #4
	bra	restore_all
	.fillinsn
2:
	srli	r0, #2
#else /* not CONFIG_SMP */
	srli	r0, #22			; r0(irq)
#endif /* not CONFIG_SMP */

#if defined(CONFIG_PLAT_HAS_INT1ICU)
	add3	r2, r0, #-(M32R_IRQ_INT1)	; INT1# interrupt
	bnez	r2, 3f
	seth	r0, #shigh(M32R_INT1ICU_ISTS)
	lduh	r0, @(low(M32R_INT1ICU_ISTS),r0)	; bit10-6 : ISN
	slli	r0, #21
	srli	r0, #27				; ISN
	addi	r0, #(M32R_INT1ICU_IRQ_BASE)
	bra	check_end
	.fillinsn
3:
#endif /* CONFIG_PLAT_HAS_INT1ICU */
#if defined(CONFIG_PLAT_HAS_INT0ICU)
	add3	r2, r0, #-(M32R_IRQ_INT0)	; INT0# interrupt
	bnez	r2, 4f
	seth	r0, #shigh(M32R_INT0ICU_ISTS)
	lduh	r0, @(low(M32R_INT0ICU_ISTS),r0)	; bit10-6 : ISN
	slli	r0, #21
	srli	r0, #27				; ISN
	add3	r0, r0, #(M32R_INT0ICU_IRQ_BASE)
	bra	check_end
	.fillinsn
4:
#endif /* CONFIG_PLAT_HAS_INT0ICU */
#if defined(CONFIG_PLAT_HAS_INT2ICU)
	add3	r2, r0, #-(M32R_IRQ_INT2)	; INT2# interrupt
	bnez	r2, 5f
	seth	r0, #shigh(M32R_INT2ICU_ISTS)
	lduh	r0, @(low(M32R_INT2ICU_ISTS),r0)	; bit10-6 : ISN
	slli	r0, #21
	srli	r0, #27				; ISN
	add3	r0, r0, #(M32R_INT2ICU_IRQ_BASE)
	; bra	check_end
	.fillinsn
5:
#endif /* CONFIG_PLAT_HAS_INT2ICU */

check_end:
	bl	do_IRQ
	pop	r14
	seth	r0, #shigh(M32R_ICU_IMASK_ADDR)
	st	r14, @(low(M32R_ICU_IMASK_ADDR),r0)
	bra  ret_from_intr

/*
 * Default EIT handler
 */
	ALIGN
int_msg:
	.asciz  "Unknown interrupt\n"
	.byte	0

ENTRY(default_eit_handler)
	push	r0
	mvfc	r0, psw
	push	r1
	push	r2
	push	r3
	push	r0
	LDIMM	(r0, __KERNEL_DS)
	mv	r0, r1
	mv	r0, r2
	LDIMM	(r0, int_msg)
	bl	printk
	pop	r0
	pop	r3
	pop	r2
	pop	r1
	mvtc	r0, psw
	pop	r0
infinit:
	bra	infinit

#ifdef CONFIG_MMU
/*
 * Access Exception handler
 */
ENTRY(ace_handler)
	SWITCH_TO_KERNEL_STACK
	SAVE_ALL

	seth	r2, #shigh(MMU_REG_BASE)	/* Check status register */
	ld	r4, @(low(MESTS_offset),r2)
	st	r4, @(low(MESTS_offset),r2)
	srl3	r1, r4, #4
#ifdef CONFIG_CHIP_M32700
	and3	r1, r1, #0x0000ffff
	; WORKAROUND: ignore TME bit for the M32700(TS1).
#endif /* CONFIG_CHIP_M32700 */
	beqz	r1, inst
oprand:
	ld	r2, @(low(MDEVA_offset),r2)	; set address
	srli	r1, #1
	bra	1f
inst:
	and3	r1, r4, #2
	srli	r1, #1
	or3	r1, r1, #8
	mvfc	r2, bpc				; set address
	.fillinsn
1:
	mvfc	r3, psw
	mv	r0, sp
	and3	r3, r3, 0x800
	srli	r3, #9
	or	r1, r3
	/*
	 * do_page_fault():
	 *    r0 : struct pt_regs *regs
	 *    r1 : unsigned long error-code
	 *    r2 : unsigned long address
	 * error-code:
	 *    +------+------+------+------+
	 *    | bit3 | bit2 | bit1 | bit0 |
	 *    +------+------+------+------+
	 *    bit 3 == 0:means data,          1:means instruction
	 *    bit 2 == 0:means kernel,        1:means user-mode
	 *    bit 1 == 0:means read,          1:means write
	 *    bit 0 == 0:means no page found  1:means protection fault
	 *
	 */
	bl	do_page_fault
	bra	ret_from_intr
#endif  /* CONFIG_MMU */


ENTRY(alignment_check)
	/* void alignment_check(int error_code) */
	SWITCH_TO_KERNEL_STACK
	SAVE_ALL
	ldi	r1, #0x30			; error_code
	mv	r0, sp				; pt_regs
	bl	do_alignment_check
error_code:
	bra	ret_from_exception

ENTRY(rie_handler)
	/* void rie_handler(int error_code) */
	SWITCH_TO_KERNEL_STACK
	SAVE_ALL
	ldi	r1, #0x20			; error_code
	mv	r0, sp				; pt_regs
	bl	do_rie_handler
	bra	error_code

ENTRY(pie_handler)
	/* void pie_handler(int error_code) */
	SWITCH_TO_KERNEL_STACK
	SAVE_ALL
	ldi	r1, #0				; error_code ; FIXME
	mv	r0, sp				; pt_regs
	bl	do_pie_handler
	bra	error_code

ENTRY(debug_trap)
	/* void debug_trap(void) */
	.global	withdraw_debug_trap
	SWITCH_TO_KERNEL_STACK
	SAVE_ALL
	mv	r0, sp				; pt_regs
	bl	withdraw_debug_trap
	ldi	r1, #0				; error_code
	mv	r0, sp				; pt_regs
	bl	do_debug_trap
	bra	error_code

ENTRY(ill_trap)
	/* void ill_trap(void) */
	SWITCH_TO_KERNEL_STACK
	SAVE_ALL
	ldi	r1, #0				; error_code ; FIXME
	mv	r0, sp				; pt_regs
	bl	do_ill_trap
	bra	error_code

ENTRY(cache_flushing_handler)
	/* void _flush_cache_all(void); */
	.global	_flush_cache_all
	SWITCH_TO_KERNEL_STACK
	push	r0
	push	r1
	push	r2
	push	r3
	push	r4
	push	r5
	push	r6
	push	r7
	push	lr
	bl	_flush_cache_all
	pop	lr
	pop	r7
	pop	r6
	pop	r5
	pop	r4
	pop	r3
	pop	r2
	pop	r1
	pop	r0
	rte

	.section .rodata,"a"
#include "syscall_table.S"

syscall_table_size=(.-sys_call_table)