summaryrefslogtreecommitdiff
path: root/arch/csky/kernel/entry.S
blob: c68cdcc76d60e4ace1a16b1d932147420619fcbd (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
/* SPDX-License-Identifier: GPL-2.0 */
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.

#include <linux/linkage.h>
#include <abi/entry.h>
#include <abi/pgtable-bits.h>
#include <asm/errno.h>
#include <asm/setup.h>
#include <asm/unistd.h>
#include <asm/asm-offsets.h>
#include <linux/threads.h>
#include <asm/page.h>
#include <asm/thread_info.h>

.macro	zero_fp
#ifdef CONFIG_STACKTRACE
	movi	r8, 0
#endif
.endm

.macro	context_tracking
#ifdef CONFIG_CONTEXT_TRACKING_USER
	mfcr	a0, epsr
	btsti	a0, 31
	bt	1f
	jbsr	user_exit_callable
	ldw	a0, (sp, LSAVE_A0)
	ldw	a1, (sp, LSAVE_A1)
	ldw	a2, (sp, LSAVE_A2)
	ldw	a3, (sp, LSAVE_A3)
#if defined(__CSKYABIV1__)
	ldw	r6, (sp, LSAVE_A4)
	ldw	r7, (sp, LSAVE_A5)
#endif
1:
#endif
.endm

.text
ENTRY(csky_pagefault)
	SAVE_ALL 0
	zero_fp
	context_tracking
	psrset  ee
	mov     a0, sp
	jbsr    do_page_fault
	jmpi    ret_from_exception

ENTRY(csky_systemcall)
	SAVE_ALL TRAP0_SIZE
	zero_fp
	context_tracking
	psrset  ee, ie

	lrw     r9, __NR_syscalls
	cmphs   syscallid, r9		/* Check nr of syscall */
	bt      ret_from_exception

	lrw     r9, sys_call_table
	ixw     r9, syscallid
	ldw     syscallid, (r9)
	cmpnei  syscallid, 0
	bf      ret_from_exception

	mov     r9, sp
	bmaski  r10, THREAD_SHIFT
	andn    r9, r10
	ldw     r10, (r9, TINFO_FLAGS)
	lrw	r9, _TIF_SYSCALL_WORK
	and	r10, r9
	cmpnei	r10, 0
	bt      csky_syscall_trace
#if defined(__CSKYABIV2__)
	subi    sp, 8
	stw  	r5, (sp, 0x4)
	stw  	r4, (sp, 0x0)
	jsr     syscallid                      /* Do system call */
	addi 	sp, 8
#else
	jsr     syscallid
#endif
	stw     a0, (sp, LSAVE_A0)      /* Save return value */
	jmpi    ret_from_exception

csky_syscall_trace:
	mov	a0, sp                  /* sp = pt_regs pointer */
	jbsr	syscall_trace_enter
	cmpnei	a0, 0
	bt	1f
	/* Prepare args before do system call */
	ldw	a0, (sp, LSAVE_A0)
	ldw	a1, (sp, LSAVE_A1)
	ldw	a2, (sp, LSAVE_A2)
	ldw	a3, (sp, LSAVE_A3)
#if defined(__CSKYABIV2__)
	subi	sp, 8
	ldw	r9, (sp, LSAVE_A4)
	stw	r9, (sp, 0x0)
	ldw	r9, (sp, LSAVE_A5)
	stw	r9, (sp, 0x4)
	jsr	syscallid                     /* Do system call */
	addi	sp, 8
#else
	ldw	r6, (sp, LSAVE_A4)
	ldw	r7, (sp, LSAVE_A5)
	jsr	syscallid                     /* Do system call */
#endif
	stw	a0, (sp, LSAVE_A0)	/* Save return value */

1:
	mov     a0, sp                  /* right now, sp --> pt_regs */
	jbsr    syscall_trace_exit
	br	ret_from_exception

ENTRY(ret_from_kernel_thread)
	jbsr	schedule_tail
	mov	a0, r10
	jsr	r9
	jbsr	ret_from_exception

ENTRY(ret_from_fork)
	jbsr	schedule_tail
	mov	r9, sp
	bmaski	r10, THREAD_SHIFT
	andn	r9, r10
	ldw	r10, (r9, TINFO_FLAGS)
	lrw	r9, _TIF_SYSCALL_WORK
	and	r10, r9
	cmpnei	r10, 0
	bf	ret_from_exception
	mov	a0, sp			/* sp = pt_regs pointer */
	jbsr	syscall_trace_exit

ret_from_exception:
	psrclr	ie
	ld	r9, (sp, LSAVE_PSR)
	btsti	r9, 31

	bt	1f
	/*
	 * Load address of current->thread_info, Then get address of task_struct
	 * Get task_needreshed in task_struct
	 */
	mov	r9, sp
	bmaski	r10, THREAD_SHIFT
	andn	r9, r10

	ldw	r10, (r9, TINFO_FLAGS)
	lrw	r9, _TIF_WORK_MASK
	and	r10, r9
	cmpnei	r10, 0
	bt	exit_work
#ifdef CONFIG_CONTEXT_TRACKING_USER
	jbsr	user_enter_callable
#endif
1:
#ifdef CONFIG_PREEMPTION
	mov	r9, sp
	bmaski	r10, THREAD_SHIFT
	andn	r9, r10

	ldw	r10, (r9, TINFO_PREEMPT)
	cmpnei	r10, 0
	bt	2f
	jbsr	preempt_schedule_irq	/* irq en/disable is done inside */
2:
#endif

#ifdef CONFIG_TRACE_IRQFLAGS
	ld	r10, (sp, LSAVE_PSR)
	btsti	r10, 6
	bf	2f
	jbsr	trace_hardirqs_on
2:
#endif
	RESTORE_ALL

exit_work:
	lrw	r9, ret_from_exception
	mov	lr, r9

	btsti	r10, TIF_NEED_RESCHED
	bt	work_resched

	psrset	ie
	mov	a0, sp
	mov	a1, r10
	jmpi	do_notify_resume

work_resched:
	jmpi	schedule

ENTRY(csky_trap)
	SAVE_ALL 0
	zero_fp
	context_tracking
	psrset	ee
	mov	a0, sp                 /* Push Stack pointer arg */
	jbsr	trap_c                 /* Call C-level trap handler */
	jmpi	ret_from_exception

/*
 * Prototype from libc for abiv1:
 * register unsigned int __result asm("a0");
 * asm( "trap 3" :"=r"(__result)::);
 */
ENTRY(csky_get_tls)
	USPTOKSP

	RD_MEH	a0
	WR_MEH	a0

	/* increase epc for continue */
	mfcr	a0, epc
	addi	a0, TRAP0_SIZE
	mtcr	a0, epc

	/* get current task thread_info with kernel 8K stack */
	bmaski	a0, THREAD_SHIFT
	not	a0
	subi	sp, 1
	and	a0, sp
	addi	sp, 1

	/* get tls */
	ldw	a0, (a0, TINFO_TP_VALUE)

	KSPTOUSP
	rte

ENTRY(csky_irq)
	SAVE_ALL 0
	zero_fp
	context_tracking
	psrset	ee

#ifdef CONFIG_TRACE_IRQFLAGS
	jbsr	trace_hardirqs_off
#endif


	mov	a0, sp
	jbsr	generic_handle_arch_irq

	jmpi	ret_from_exception

/*
 * a0 =  prev task_struct *
 * a1 =  next task_struct *
 * a0 =  return next
 */
ENTRY(__switch_to)
	lrw	a3, TASK_THREAD
	addu	a3, a0

	SAVE_SWITCH_STACK

	stw	sp, (a3, THREAD_KSP)

	/* Set up next process to run */
	lrw	a3, TASK_THREAD
	addu	a3, a1

	ldw	sp, (a3, THREAD_KSP)	/* Set next kernel sp */

#if  defined(__CSKYABIV2__)
	addi	a3, a1, TASK_THREAD_INFO
	ldw	tls, (a3, TINFO_TP_VALUE)
#endif

	RESTORE_SWITCH_STACK

	rts
ENDPROC(__switch_to)