1
2
3
4 #include <linux/linkage.h>
5 #include <asm/unistd.h>
6 #include <asm/assembler.h>
7 #include <asm/nds32.h>
8 #include <asm/asm-offsets.h>
9 #include <asm/thread_info.h>
10 #include <asm/current.h>
11 #include <asm/fpu.h>
12
13
14
15 #ifdef CONFIG_HWZOL
16 .macro pop_zol
17 mtusr $r14, $LB
18 mtusr $r15, $LE
19 mtusr $r16, $LC
20 .endm
21 #endif
22
23 .macro restore_user_regs_first
24 setgie.d
25 isb
26 #if defined(CONFIG_FPU)
27 addi $sp, $sp, OSP_OFFSET
28 lmw.adm $r12, [$sp], $r25, #0x0
29 sethi $p0, hi20(has_fpu)
30 lbsi $p0, [$p0+lo12(has_fpu)]
31 beqz $p0, 2f
32 mtsr $r25, $FUCOP_CTL
33 2:
34 #else
35 addi $sp, $sp, FUCOP_CTL_OFFSET
36 lmw.adm $r12, [$sp], $r24, #0x0
37 #endif
38 mtsr $r12, $SP_USR
39 mtsr $r13, $IPC
40 #ifdef CONFIG_HWZOL
41 pop_zol
42 #endif
43 mtsr $r19, $PSW
44 mtsr $r20, $IPSW
45 mtsr $r21, $P_IPSW
46 mtsr $r22, $P_IPC
47 mtsr $r23, $P_P0
48 mtsr $r24, $P_P1
49 lmw.adm $sp, [$sp], $sp, #0xe
50 .endm
51
52 .macro restore_user_regs_last
53 pop $p0
54 cmovn $sp, $p0, $p0
55
56 iret
57 nop
58
59 .endm
60
61 .macro restore_user_regs
62 restore_user_regs_first
63 lmw.adm $r0, [$sp], $r25, #0x0
64 addi $sp, $sp, OSP_OFFSET
65 restore_user_regs_last
66 .endm
67
68 .macro fast_restore_user_regs
69 restore_user_regs_first
70 lmw.adm $r1, [$sp], $r25, #0x0
71 addi $sp, $sp, OSP_OFFSET-4
72 restore_user_regs_last
73 .endm
74
75 #ifdef CONFIG_PREEMPT
76 .macro preempt_stop
77 .endm
78 #else
79 .macro preempt_stop
80 setgie.d
81 isb
82 .endm
83 #define resume_kernel no_work_pending
84 #endif
85
86 ENTRY(ret_from_exception)
87 preempt_stop
88 ENTRY(ret_from_intr)
89
90
91
92
93
94 lwi $p0, [$sp+(#IPSW_OFFSET)] ! Check if in nested interrupt
95 andi $p0, $p0, #PSW_mskINTL
96 bnez $p0, resume_kernel ! done with iret
97 j resume_userspace
98
99
100
101
102
103
104
105
106 ENTRY(ret_fast_syscall)
107 gie_disable
108 lwi $r1, [tsk+#TSK_TI_FLAGS]
109 andi $p1, $r1, #_TIF_WORK_MASK
110 bnez $p1, fast_work_pending
111 fast_restore_user_regs ! iret
112
113
114
115
116
117 fast_work_pending:
118 swi $r0, [$sp+(#R0_OFFSET)] ! what is different from ret_from_exception
119 work_pending:
120 andi $p1, $r1, #_TIF_NEED_RESCHED
121 bnez $p1, work_resched
122
123 andi $p1, $r1, #_TIF_SIGPENDING|#_TIF_NOTIFY_RESUME
124 beqz $p1, no_work_pending
125
126 move $r0, $sp ! 'regs'
127 gie_enable
128 bal do_notify_resume
129 b ret_slow_syscall
130 work_resched:
131 bal schedule ! path, return to user mode
132
133
134
135
136 ENTRY(resume_userspace)
137 ENTRY(ret_slow_syscall)
138 gie_disable
139 lwi $p0, [$sp+(#IPSW_OFFSET)] ! Check if in nested interrupt
140 andi $p0, $p0, #PSW_mskINTL
141 bnez $p0, no_work_pending ! done with iret
142 lwi $r1, [tsk+#TSK_TI_FLAGS]
143 andi $p1, $r1, #_TIF_WORK_MASK
144 bnez $p1, work_pending ! handle work_resched, sig_pend
145
146 no_work_pending:
147 #ifdef CONFIG_TRACE_IRQFLAGS
148 lwi $p0, [$sp+(#IPSW_OFFSET)]
149 andi $p0, $p0, #0x1
150 la $r10, __trace_hardirqs_off
151 la $r9, __trace_hardirqs_on
152 cmovz $r9, $p0, $r10
153 jral $r9
154 #endif
155 restore_user_regs ! return from iret
156
157
158
159
160
161 #ifdef CONFIG_PREEMPT
162 resume_kernel:
163 gie_disable
164 lwi $t0, [tsk+#TSK_TI_PREEMPT]
165 bnez $t0, no_work_pending
166
167 lwi $t0, [tsk+#TSK_TI_FLAGS]
168 andi $p1, $t0, #_TIF_NEED_RESCHED
169 beqz $p1, no_work_pending
170
171 lwi $t0, [$sp+(#IPSW_OFFSET)] ! Interrupts off?
172 andi $t0, $t0, #1
173 beqz $t0, no_work_pending
174
175 jal preempt_schedule_irq
176 b no_work_pending
177 #endif
178
179
180
181
182 ENTRY(ret_from_fork)
183 bal schedule_tail
184 beqz $r6, 1f ! r6 stores fn for kernel thread
185 move $r0, $r7 ! prepare kernel thread arg
186 jral $r6
187 1:
188 lwi $r1, [tsk+#TSK_TI_FLAGS] ! check for syscall tracing
189 andi $p1, $r1, #_TIF_WORK_SYSCALL_LEAVE ! are we tracing syscalls?
190 beqz $p1, ret_slow_syscall
191 move $r0, $sp
192 bal syscall_trace_leave
193 b ret_slow_syscall