summaryrefslogtreecommitdiffstats
path: root/arch/h8300/kernel/entry.S
blob: 2cdb49a56099bb32940c0c3fb4cdaf20b547de64 (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
/* -*- mode: asm -*-
 *
 *  linux/arch/h8300/platform/h8300h/entry.S
 *
 *  Yoshinori Sato <ysato@users.sourceforge.jp>
 *  David McCullough <davidm@snapgear.com>
 *
 */

/*
 *  entry.S
 *  include exception/interrupt gateway
 *          system call entry
 */

#include <linux/sys.h>
#include <asm/unistd.h>
#include <asm/setup.h>
#include <asm/segment.h>
#include <asm/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
#include <asm/errno.h>

#if defined(CONFIG_CPU_H8300H)
#define USERRET 8
INTERRUPTS = 64
	.h8300h
	.macro	SHLL2 reg
	shll.l	\reg
	shll.l	\reg
	.endm
	.macro	SHLR2 reg
	shlr.l	\reg
	shlr.l	\reg
	.endm
	.macro	SAVEREGS
	mov.l	er0,@-sp
	mov.l	er1,@-sp
	mov.l	er2,@-sp
	mov.l	er3,@-sp
	.endm
	.macro	RESTOREREGS
	mov.l	@sp+,er3
	mov.l	@sp+,er2
	.endm
	.macro	SAVEEXR
	.endm
	.macro	RESTOREEXR
	.endm
#endif
#if defined(CONFIG_CPU_H8S)
#define USERRET 10
#define USEREXR 8
INTERRUPTS = 128
	.h8300s
	.macro	SHLL2 reg
	shll.l	#2,\reg
	.endm
	.macro	SHLR2 reg
	shlr.l	#2,\reg
	.endm
	.macro	SAVEREGS
	stm.l	er0-er3,@-sp
	.endm
	.macro	RESTOREREGS
	ldm.l	@sp+,er2-er3
	.endm
	.macro	SAVEEXR
	mov.w	@(USEREXR:16,er0),r1
	mov.w	r1,@(LEXR-LER3:16,sp)		/* copy EXR */
	.endm
	.macro	RESTOREEXR
	mov.w	@(LEXR-LER1:16,sp),r1		/* restore EXR */
	mov.b	r1l,r1h
	mov.w	r1,@(USEREXR:16,er0)
	.endm
#endif


/* CPU context save/restore macros. */

	.macro	SAVE_ALL
	mov.l	er0,@-sp
	stc	ccr,r0l				/* check kernel mode */
	btst	#4,r0l
	bne	5f

	/* user mode */
	mov.l	sp,@SYMBOL_NAME(sw_usp)
	mov.l	@sp,er0				/* restore saved er0 */
	orc	#0x10,ccr			/* switch kernel stack */
	mov.l	@SYMBOL_NAME(sw_ksp),sp
	sub.l	#(LRET-LORIG),sp		/* allocate LORIG - LRET */
	SAVEREGS
	mov.l   @SYMBOL_NAME(sw_usp),er0
	mov.l   @(USERRET:16,er0),er1           /* copy the RET addr */
	mov.l   er1,@(LRET-LER3:16,sp)
	SAVEEXR

	mov.l	@(LORIG-LER3:16,sp),er0
	mov.l	er0,@(LER0-LER3:16,sp)		/* copy ER0 */
	mov.w	e1,r1				/* e1 highbyte = ccr */
	and	#0xef,r1h			/* mask mode? flag */
	bra	6f
5:
	/* kernel mode */
	mov.l	@sp,er0				/* restore saved er0 */
	subs	#2,sp				/* set dummy ccr */
	SAVEREGS
	mov.w	@(LRET-LER3:16,sp),r1		/* copy old ccr */
6:
	mov.b	r1h,r1l
	mov.b	#0,r1h
	mov.w	r1,@(LCCR-LER3:16,sp)		/* set ccr */
	mov.l	er6,@-sp			/* syscall arg #6 */
	mov.l	er5,@-sp			/* syscall arg #5 */
	mov.l	er4,@-sp			/* syscall arg #4 */
	.endm					/* r1 = ccr */

	.macro	RESTORE_ALL
	mov.l	@sp+,er4
	mov.l	@sp+,er5
	mov.l	@sp+,er6
	RESTOREREGS
	mov.w	@(LCCR-LER1:16,sp),r0		/* check kernel mode */
	btst	#4,r0l
	bne	7f

	orc	#0x80,ccr
	mov.l	@SYMBOL_NAME(sw_usp),er0
	mov.l	@(LER0-LER1:16,sp),er1		/* restore ER0 */
	mov.l	er1,@er0
	RESTOREEXR
	mov.w	@(LCCR-LER1:16,sp),r1		/* restore the RET addr */
	mov.b	r1l,r1h
	mov.b	@(LRET+1-LER1:16,sp),r1l
	mov.w	r1,e1
	mov.w	@(LRET+2-LER1:16,sp),r1
	mov.l	er1,@(USERRET:16,er0)

	mov.l	@sp+,er1
	add.l	#(LRET-LER1),sp			/* remove LORIG - LRET */
	mov.l	sp,@SYMBOL_NAME(sw_ksp)
	andc	#0xef,ccr			/* switch to user mode */
	mov.l	er0,sp
	bra	8f
7:
	mov.l	@sp+,er1
	adds	#4,sp
	adds	#2,sp
8:
	mov.l	@sp+,er0
	adds	#4,sp				/* remove the sw created LVEC */
	rte
	.endm

.globl SYMBOL_NAME(system_call)
.globl SYMBOL_NAME(ret_from_exception)
.globl SYMBOL_NAME(ret_from_fork)
.globl SYMBOL_NAME(ret_from_kernel_thread)
.globl SYMBOL_NAME(ret_from_interrupt)
.globl SYMBOL_NAME(interrupt_redirect_table)
.globl SYMBOL_NAME(sw_ksp),SYMBOL_NAME(sw_usp)
.globl SYMBOL_NAME(resume)
.globl SYMBOL_NAME(interrupt_entry)
.globl SYMBOL_NAME(trace_break)

#if defined(CONFIG_ROMKERNEL)
	.section .int_redirect,"ax"
SYMBOL_NAME_LABEL(interrupt_redirect_table)
#if defined(CONFIG_CPU_H8300H)
	.rept	7
	.long	0
	.endr
#endif
#if defined(CONFIG_CPU_H8S)
	.rept	5
	.long	0
	.endr
	jmp	@SYMBOL_NAME(trace_break)
	.long	0
#endif

	jsr	@SYMBOL_NAME(interrupt_entry)	/* NMI */
	jmp	@SYMBOL_NAME(system_call)	/* TRAPA #0 (System call) */
	.long	0
	.long	0
	jmp	@SYMBOL_NAME(trace_break)	/* TRAPA #3 (breakpoint) */
	.rept	INTERRUPTS-12
	jsr	@SYMBOL_NAME(interrupt_entry)
	.endr
#endif
#if defined(CONFIG_RAMKERNEL)
.globl SYMBOL_NAME(interrupt_redirect_table)
	.section .bss
SYMBOL_NAME_LABEL(interrupt_redirect_table)
	.space	4
#endif

	.section .text
	.align	2
SYMBOL_NAME_LABEL(interrupt_entry)
	SAVE_ALL
	mov.l	sp,er0
	add.l	#LVEC,er0
	btst	#4,r1l
	bne	1f
	/* user LVEC */
	mov.l	@SYMBOL_NAME(sw_usp),er0
	adds	#4,er0
1:
	mov.l	@er0,er0			/* LVEC address */
#if defined(CONFIG_ROMKERNEL)
	sub.l	#SYMBOL_NAME(interrupt_redirect_table),er0
#endif
#if defined(CONFIG_RAMKERNEL)
	mov.l	@SYMBOL_NAME(interrupt_redirect_table),er1
	sub.l	er1,er0
#endif
	SHLR2	er0
	dec.l	#1,er0
	mov.l	sp,er1
	subs	#4,er1				/* adjust ret_pc */
	jsr	@SYMBOL_NAME(do_IRQ)
	jmp	@SYMBOL_NAME(ret_from_interrupt)

SYMBOL_NAME_LABEL(system_call)
	subs	#4,sp				/* dummy LVEC */
	SAVE_ALL
	andc	#0x7f,ccr
	mov.l	er0,er4

	/* save top of frame */
	mov.l	sp,er0
	jsr	@SYMBOL_NAME(set_esp0)
	mov.l	sp,er2
	and.w	#0xe000,r2
	mov.b	@((TI_FLAGS+3-(TIF_SYSCALL_TRACE >> 3)):16,er2),r2l
	btst	#(TIF_SYSCALL_TRACE & 7),r2l
	beq	1f
	jsr	@SYMBOL_NAME(do_syscall_trace)
1:
	cmp.l	#NR_syscalls,er4
	bcc	badsys
	SHLL2	er4
	mov.l	#SYMBOL_NAME(sys_call_table),er0
	add.l	er4,er0
	mov.l	@er0,er4
	beq	SYMBOL_NAME(ret_from_exception):16
	mov.l	@(LER1:16,sp),er0
	mov.l	@(LER2:16,sp),er1
	mov.l	@(LER3:16,sp),er2
	jsr	@er4
	mov.l	er0,@(LER0:16,sp)		/* save the return value */
	mov.l	sp,er2
	and.w	#0xe000,r2
	mov.b	@((TI_FLAGS+3-(TIF_SYSCALL_TRACE >> 3)):16,er2),r2l
	btst	#(TIF_SYSCALL_TRACE & 7),r2l
	beq	2f
	jsr	@SYMBOL_NAME(do_syscall_trace)
2:
#if defined(CONFIG_SYSCALL_PRINT)
	jsr	@SYMBOL_NAME(syscall_print)
#endif
	orc	#0x80,ccr
	bra	resume_userspace

badsys:
	mov.l	#-ENOSYS,er0
	mov.l	er0,@(LER0:16,sp)
	bra	resume_userspace

#if !defined(CONFIG_PREEMPT)
#define resume_kernel restore_all
#endif

SYMBOL_NAME_LABEL(ret_from_exception)
#if defined(CONFIG_PREEMPT)
	orc	#0x80,ccr
#endif
SYMBOL_NAME_LABEL(ret_from_interrupt)
	mov.b	@(LCCR+1:16,sp),r0l
	btst	#4,r0l
	bne	resume_kernel:8		/* return from kernel */
resume_userspace:
	andc	#0x7f,ccr
	mov.l	sp,er4
	and.w	#0xe000,r4		/* er4 <- current thread info */
	mov.l	@(TI_FLAGS:16,er4),er1
	and.l	#_TIF_WORK_MASK,er1
	beq	restore_all:8
work_pending:
	btst	#TIF_NEED_RESCHED,r1l
	bne	work_resched:8
	/* work notifysig */
	mov.l	sp,er0
	subs	#4,er0			/* er0: pt_regs */
	jsr	@SYMBOL_NAME(do_notify_resume)
	bra	restore_all:8
work_resched:
	mov.l	sp,er0
	jsr	@SYMBOL_NAME(set_esp0)
	jsr	@SYMBOL_NAME(schedule)
	bra	resume_userspace:8
restore_all:
	RESTORE_ALL			/* Does RTE */

#if defined(CONFIG_PREEMPT)
resume_kernel:
	mov.l	@(TI_PRE_COUNT:16,er4),er0
	bne	restore_all:8
need_resched:
	mov.l	@(TI_FLAGS:16,er4),er0
	btst	#TIF_NEED_RESCHED,r0l
	beq	restore_all:8
	mov.b	@(LCCR+1:16,sp),r0l	/* Interrupt Enabled? */
	bmi	restore_all:8
	mov.l	#PREEMPT_ACTIVE,er0
	mov.l	er0,@(TI_PRE_COUNT:16,er4)
	andc	#0x7f,ccr
	mov.l	sp,er0
	jsr	@SYMBOL_NAME(set_esp0)
	jsr	@SYMBOL_NAME(schedule)
	orc	#0x80,ccr
	bra	need_resched:8
#endif

SYMBOL_NAME_LABEL(ret_from_fork)
	mov.l	er2,er0
	jsr	@SYMBOL_NAME(schedule_tail)
	jmp	@SYMBOL_NAME(ret_from_exception)

SYMBOL_NAME_LABEL(ret_from_kernel_thread)
	mov.l	er2,er0
	jsr	@SYMBOL_NAME(schedule_tail)
	mov.l	@(LER4:16,sp),er0
	mov.l	@(LER5:16,sp),er1
	jsr	@er1
	sub.l	@er0,@er0
	jsr	@SYMBOL_NAME(sys_exit)

SYMBOL_NAME_LABEL(resume)
	/*
	 * Beware - when entering resume, offset of tss is in d1,
	 * prev (the current task) is in a0, next (the new task)
	 * is in a1 and d2.b is non-zero if the mm structure is
	 * shared between the tasks, so don't change these
	 * registers until their contents are no longer needed.
	 */

	/* save sr */
	sub.w	r3,r3
	stc	ccr,r3l
	mov.w	r3,@(THREAD_CCR+2:16,er0)

	/* disable interrupts */
	orc	#0x80,ccr
	mov.l	@SYMBOL_NAME(sw_usp),er3
	mov.l	er3,@(THREAD_USP:16,er0)
	mov.l	sp,@(THREAD_KSP:16,er0)

	/* Skip address space switching if they are the same. */
	/* FIXME: what did we hack out of here, this does nothing! */

	mov.l	@(THREAD_USP:16,er1),er0
	mov.l	er0,@SYMBOL_NAME(sw_usp)
	mov.l	@(THREAD_KSP:16,er1),sp

	/* restore status register */
	mov.w	@(THREAD_CCR+2:16,er1),r3

	ldc	r3l,ccr
	rts

SYMBOL_NAME_LABEL(trace_break)
	subs	#4,sp
	SAVE_ALL
	sub.l	er1,er1
	dec.l	#1,er1
	mov.l	er1,@(LORIG,sp)
	mov.l	sp,er0
	jsr	@SYMBOL_NAME(set_esp0)
	mov.l	@SYMBOL_NAME(sw_usp),er0
	mov.l	@er0,er1
	mov.w	@(-2:16,er1),r2
	cmp.w	#0x5730,r2
	beq	1f
	subs	#2,er1
	mov.l	er1,@er0
1:
	and.w	#0xff,e1
	mov.l	er1,er0
	jsr	@SYMBOL_NAME(trace_trap)
	jmp	@SYMBOL_NAME(ret_from_exception)

	.section	.bss
SYMBOL_NAME_LABEL(sw_ksp)
	.space	4
SYMBOL_NAME_LABEL(sw_usp)
	.space	4

	.end