| 1 | /*
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| 2 | * MIPS specific _mcount support
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| 3 | *
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| 4 | * This file is subject to the terms and conditions of the GNU General Public
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| 5 | * License. See the file "COPYING" in the main directory of this archive for
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| 6 | * more details.
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| 7 | *
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| 8 | * Copyright (C) 2009 Lemote Inc. & DSLab, Lanzhou University, China
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| 9 | * Copyright (C) 2010 DSLab, Lanzhou University, China
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| 10 | * Author: Wu Zhangjin <wuzhangjin@gmail.com>
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| 11 | */
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| 12 |
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| 13 | |
| 14 | |
| 15 | |
| 16 | |
| 17 |
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| 18 | .text
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| 19 | .set noreorder
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| 20 | .set noat
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| 21 |
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| 22 | .macro MCOUNT_SAVE_REGS
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| 23 | PTR_SUBU sp, PT_SIZE
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| 24 | PTR_S ra, PT_R31(sp)
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| 25 | PTR_S AT, PT_R1(sp)
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| 26 | PTR_S a0, PT_R4(sp)
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| 27 | PTR_S a1, PT_R5(sp)
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| 28 | PTR_S a2, PT_R6(sp)
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| 29 | PTR_S a3, PT_R7(sp)
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| 30 | |
| 31 | PTR_S a4, PT_R8(sp)
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| 32 | PTR_S a5, PT_R9(sp)
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| 33 | PTR_S a6, PT_R10(sp)
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| 34 | PTR_S a7, PT_R11(sp)
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| 35 | |
| 36 | .endm
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| 37 |
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| 38 | .macro MCOUNT_RESTORE_REGS
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| 39 | PTR_L ra, PT_R31(sp)
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| 40 | PTR_L AT, PT_R1(sp)
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| 41 | PTR_L a0, PT_R4(sp)
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| 42 | PTR_L a1, PT_R5(sp)
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| 43 | PTR_L a2, PT_R6(sp)
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| 44 | PTR_L a3, PT_R7(sp)
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| 45 | |
| 46 | PTR_L a4, PT_R8(sp)
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| 47 | PTR_L a5, PT_R9(sp)
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| 48 | PTR_L a6, PT_R10(sp)
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| 49 | PTR_L a7, PT_R11(sp)
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| 50 | |
| 51 | PTR_ADDIU sp, PT_SIZE
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| 52 | .endm
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| 53 |
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| 54 | .macro RETURN_BACK
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| 55 | jr ra
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| 56 | move ra, AT
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| 57 | .endm
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| 58 |
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| 59 | /*
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| 60 | * The -mmcount-ra-address option of gcc 4.5 uses register $12 to pass
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| 61 | * the location of the parent's return address.
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| 62 | */
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| 63 | #define MCOUNT_RA_ADDRESS_REG $12
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| 64 |
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| 65 | #ifdef CONFIG_DYNAMIC_FTRACE
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| 66 |
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| 67 | NESTED(ftrace_caller, PT_SIZE, ra)
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| 68 | .globl _mcount
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| 69 | _mcount:
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| 70 | EXPORT_SYMBOL(_mcount)
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| 71 | b ftrace_stub
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| 72 | #ifdef CONFIG_32BIT
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| 73 | addiu sp,sp,8
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| 74 | #else
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| 75 | nop
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| 76 | #endif
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| 77 |
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| 78 | /* When tracing is activated, it calls ftrace_caller+8 (aka here) */
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| 79 | MCOUNT_SAVE_REGS
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| 80 | #ifdef KBUILD_MCOUNT_RA_ADDRESS
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| 81 | PTR_S MCOUNT_RA_ADDRESS_REG, PT_R12(sp)
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| 82 | #endif
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| 83 |
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| 84 | PTR_SUBU a0, ra, 8 /* arg1: self address */
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| 85 | PTR_LA t1, _stext
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| 86 | sltu t2, a0, t1 /* t2 = (a0 < _stext) */
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| 87 | PTR_LA t1, _etext
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| 88 | sltu t3, t1, a0 /* t3 = (a0 > _etext) */
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| 89 | or t1, t2, t3
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| 90 | beqz t1, ftrace_call
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| 91 | nop
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| 92 | #if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT)
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| 93 | PTR_SUBU a0, a0, 16 /* arg1: adjust to module's recorded callsite */
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| 94 | |
| 95 | PTR_SUBU a0, a0, 12
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| 96 | |
| 97 |
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| 98 | .globl ftrace_call
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| 99 | ftrace_call:
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| 100 | nop /* a placeholder for the call to a real tracing function */
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| 101 | move a1, AT /* arg2: parent's return address */
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| 102 |
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| 103 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER
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| 104 | .globl ftrace_graph_call
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| 105 | ftrace_graph_call:
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| 106 | nop
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| 107 | nop
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| 108 | #endif
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| 109 |
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| 110 | MCOUNT_RESTORE_REGS
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| 111 | .globl ftrace_stub
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| 112 | ftrace_stub:
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| 113 | RETURN_BACK
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| 114 | END(ftrace_caller)
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| 115 |
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| 116 | #else /* ! CONFIG_DYNAMIC_FTRACE */
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| 117 |
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| 118 | NESTED(_mcount, PT_SIZE, ra)
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| 119 | EXPORT_SYMBOL(_mcount)
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| 120 | PTR_LA t1, ftrace_stub
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| 121 | PTR_L t2, ftrace_trace_function /* Prepare t2 for (1) */
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| 122 | beq t1, t2, fgraph_trace
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| 123 | nop
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| 124 |
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| 125 | MCOUNT_SAVE_REGS
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| 126 |
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| 127 | move a0, ra /* arg1: self return address */
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| 128 | jalr t2 /* (1) call *ftrace_trace_function */
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| 129 | move a1, AT /* arg2: parent's return address */
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| 130 |
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| 131 | MCOUNT_RESTORE_REGS
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| 132 |
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| 133 | fgraph_trace:
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| 134 | |
| 135 | PTR_LA t1, ftrace_stub
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| 136 | PTR_L t3, ftrace_graph_return
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| 137 | bne t1, t3, ftrace_graph_caller
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| 138 | nop
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| 139 | PTR_LA t1, ftrace_graph_entry_stub
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| 140 | PTR_L t3, ftrace_graph_entry
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| 141 | bne t1, t3, ftrace_graph_caller
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| 142 | nop
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| 143 | |
| 144 |
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| 145 | |
| 146 | addiu sp, sp, 8
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| 147 | |
| 148 |
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| 149 | .globl ftrace_stub
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| 150 | ftrace_stub:
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| 151 | RETURN_BACK
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| 152 | END(_mcount)
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| 153 |
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| 154 | |
| 155 |
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| 156 | |
| 157 |
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| 158 | NESTED(ftrace_graph_caller, PT_SIZE, ra)
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| 159 | |
| 160 | MCOUNT_SAVE_REGS
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| 161 | |
| 162 |
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| 163 | /* arg1: Get the location of the parent's return address */
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| 164 | #ifdef KBUILD_MCOUNT_RA_ADDRESS
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| 165 | #ifdef CONFIG_DYNAMIC_FTRACE
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| 166 | PTR_L a0, PT_R12(sp)
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| 167 | #else
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| 168 | move a0, MCOUNT_RA_ADDRESS_REG
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| 169 | #endif
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| 170 | bnez a0, 1f /* non-leaf func: stored in MCOUNT_RA_ADDRESS_REG */
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| 171 | nop
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| 172 | #endif
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| 173 | PTR_LA a0, PT_R1(sp) /* leaf func: the location in current stack */
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| 174 | 1:
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| 175 |
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| 176 | /* arg2: Get self return address */
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| 177 | #ifdef CONFIG_DYNAMIC_FTRACE
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| 178 | PTR_L a1, PT_R31(sp)
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| 179 | #else
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| 180 | move a1, ra
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| 181 | #endif
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| 182 |
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| 183 | /* arg3: Get frame pointer of current stack */
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| 184 | #ifdef CONFIG_64BIT
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| 185 | PTR_LA a2, PT_SIZE(sp)
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| 186 | #else
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| 187 | PTR_LA a2, (PT_SIZE+8)(sp)
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| 188 | #endif
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| 189 |
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| 190 | jal prepare_ftrace_return
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| 191 | nop
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| 192 | MCOUNT_RESTORE_REGS
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| 193 | #ifndef CONFIG_DYNAMIC_FTRACE
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| 194 | #ifdef CONFIG_32BIT
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| 195 | addiu sp, sp, 8
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| 196 | #endif
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| 197 | #endif
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| 198 | RETURN_BACK
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| 199 | END(ftrace_graph_caller)
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| 200 |
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| 201 | .align 2
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| 202 | .globl return_to_handler
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| 203 | return_to_handler:
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| 204 | PTR_SUBU sp, PT_SIZE
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| 205 | PTR_S v0, PT_R2(sp)
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| 206 |
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| 207 | jal ftrace_return_to_handler
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| 208 | PTR_S v1, PT_R3(sp)
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| 209 |
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| 210 | /* restore the real parent address: v0 -> ra */
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| 211 | move ra, v0
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| 212 |
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| 213 | PTR_L v0, PT_R2(sp)
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| 214 | PTR_L v1, PT_R3(sp)
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| 215 | jr ra
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| 216 | PTR_ADDIU sp, PT_SIZE
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| 217 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
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| 218 |
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| 219 | .set at
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| 220 | .set reorder
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