aboutsummaryrefslogtreecommitdiff
path: root/arch/mips/kernel/entry.S
blob: a9c6de1b954257e8e30e73518009f7cf3d1444ae (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
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1994 - 2000, 2001, 2003 Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Copyright (C) 2001 MIPS Technologies, Inc.
 */
#include <linux/config.h>

#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>
#include <asm/stackframe.h>
#include <asm/isadep.h>
#include <asm/thread_info.h>
#include <asm/war.h>
#ifdef CONFIG_MIPS_MT_SMTC
#include <asm/mipsmtregs.h>
#endif

#ifdef CONFIG_PREEMPT
	.macro	preempt_stop
	.endm
#else
	.macro	preempt_stop
	local_irq_disable
	.endm
#define resume_kernel	restore_all
#endif

	.text
	.align	5
FEXPORT(ret_from_exception)
	preempt_stop
FEXPORT(ret_from_irq)
	LONG_L	t0, PT_STATUS(sp)		# returning to kernel mode?
	andi	t0, t0, KU_USER
	beqz	t0, resume_kernel

resume_userspace:
	local_irq_disable		# make sure we dont miss an
					# interrupt setting need_resched
					# between sampling and return
	LONG_L	a2, TI_FLAGS($28)	# current->work
	andi	t0, a2, _TIF_WORK_MASK	# (ignoring syscall_trace)
	bnez	t0, work_pending
	j	restore_all

#ifdef CONFIG_PREEMPT
resume_kernel:
	local_irq_disable
	lw	t0, TI_PRE_COUNT($28)
	bnez	t0, restore_all
need_resched:
	LONG_L	t0, TI_FLAGS($28)
	andi	t1, t0, _TIF_NEED_RESCHED
	beqz	t1, restore_all
	LONG_L	t0, PT_STATUS(sp)		# Interrupts off?
	andi	t0, 1
	beqz	t0, restore_all
	jal	preempt_schedule_irq
	b	need_resched
#endif

FEXPORT(ret_from_fork)
	jal	schedule_tail		# a0 = task_t *prev

FEXPORT(syscall_exit)
	local_irq_disable		# make sure need_resched and
					# signals dont change between
					# sampling and return
	LONG_L	a2, TI_FLAGS($28)	# current->work
	li	t0, _TIF_ALLWORK_MASK
	and	t0, a2, t0
	bnez	t0, syscall_exit_work

FEXPORT(restore_all)			# restore full frame
#ifdef CONFIG_MIPS_MT_SMTC
/* Detect and execute deferred IPI "interrupts" */
	move	a0,sp
	jal	deferred_smtc_ipi
/* Re-arm any temporarily masked interrupts not explicitly "acked" */
	mfc0	v0, CP0_TCSTATUS
	ori	v1, v0, TCSTATUS_IXMT
	mtc0	v1, CP0_TCSTATUS
	andi	v0, TCSTATUS_IXMT
	ehb
	mfc0	t0, CP0_TCCONTEXT
	DMT	9				# dmt t1
	jal	mips_ihb
	mfc0	t2, CP0_STATUS
	andi	t3, t0, 0xff00
	or	t2, t2, t3
	mtc0	t2, CP0_STATUS
	ehb
	andi	t1, t1, VPECONTROL_TE
	beqz	t1, 1f
	EMT
1:
	mfc0	v1, CP0_TCSTATUS
	/* We set IXMT above, XOR should clear it here */
	xori	v1, v1, TCSTATUS_IXMT
	or	v1, v0, v1
	mtc0	v1, CP0_TCSTATUS
	ehb
	xor	t0, t0, t3
	mtc0	t0, CP0_TCCONTEXT
#endif /* CONFIG_MIPS_MT_SMTC */
	.set	noat
	RESTORE_TEMP
	RESTORE_AT
	RESTORE_STATIC
FEXPORT(restore_partial)		# restore partial frame
	RESTORE_SOME
	RESTORE_SP_AND_RET
	.set	at

work_pending:
	andi	t0, a2, _TIF_NEED_RESCHED # a2 is preloaded with TI_FLAGS
	beqz	t0, work_notifysig
work_resched:
	jal	schedule

	local_irq_disable		# make sure need_resched and
					# signals dont change between
					# sampling and return
	LONG_L	a2, TI_FLAGS($28)
	andi	t0, a2, _TIF_WORK_MASK	# is there any work to be done
					# other than syscall tracing?
	beqz	t0, restore_all
	andi	t0, a2, _TIF_NEED_RESCHED
	bnez	t0, work_resched

work_notifysig:				# deal with pending signals and
					# notify-resume requests
	move	a0, sp
	li	a1, 0
	jal	do_notify_resume	# a2 already loaded
	j	resume_userspace

FEXPORT(syscall_exit_work_partial)
	SAVE_STATIC
syscall_exit_work:
	li	t0, _TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT
	and	t0, a2			# a2 is preloaded with TI_FLAGS
	beqz	t0, work_pending	# trace bit set?
	local_irq_enable		# could let do_syscall_trace()
					# call schedule() instead
	move	a0, sp
	li	a1, 1
	jal	do_syscall_trace
	b	resume_userspace

#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_MIPS_MT)

/*
 * MIPS32R2 Instruction Hazard Barrier - must be called
 *
 * For C code use the inline version named instruction_hazard().
 */
LEAF(mips_ihb)
	.set	mips32r2
	jr.hb	ra
	nop
	END(mips_ihb)

#endif /* CONFIG_CPU_MIPSR2 or CONFIG_MIPS_MT */