1 /* SPDX-License-Identifier: GPL-2.0 */ <<
2 /* 1 /*
3 * LoongArch specific _mcount support !! 2 * MIPS specific _mcount support
4 * 3 *
5 * Copyright (C) 2022 Loongson Technology Corp !! 4 * This file is subject to the terms and conditions of the GNU General Public
>> 5 * License. See the file "COPYING" in the main directory of this archive for
>> 6 * more details.
>> 7 *
>> 8 * Copyright (C) 2009 Lemote Inc. & DSLab, Lanzhou University, China
>> 9 * Copyright (C) 2010 DSLab, Lanzhou University, China
>> 10 * Author: Wu Zhangjin <wuzhangjin@gmail.com>
6 */ 11 */
7 12
8 #include <linux/export.h> <<
9 #include <asm/ftrace.h> <<
10 #include <asm/regdef.h> 13 #include <asm/regdef.h>
11 #include <asm/stackframe.h> 14 #include <asm/stackframe.h>
>> 15 #include <asm/ftrace.h>
12 16
13 .text 17 .text
14 !! 18 .set noreorder
15 #define MCOUNT_S0_OFFSET (0) !! 19 .set noat
16 #define MCOUNT_RA_OFFSET (SZREG) <<
17 #define MCOUNT_STACK_SIZE (2 * SZREG) <<
18 20
19 .macro MCOUNT_SAVE_REGS 21 .macro MCOUNT_SAVE_REGS
20 PTR_ADDI sp, sp, -MCOUNT_STACK_ !! 22 PTR_SUBU sp, PT_SIZE
21 PTR_S s0, sp, MCOUNT_S0_OFFS !! 23 PTR_S ra, PT_R31(sp)
22 PTR_S ra, sp, MCOUNT_RA_OFFS !! 24 PTR_S AT, PT_R1(sp)
23 move s0, a0 !! 25 PTR_S a0, PT_R4(sp)
>> 26 PTR_S a1, PT_R5(sp)
>> 27 PTR_S a2, PT_R6(sp)
>> 28 PTR_S a3, PT_R7(sp)
>> 29 #ifdef CONFIG_64BIT
>> 30 PTR_S a4, PT_R8(sp)
>> 31 PTR_S a5, PT_R9(sp)
>> 32 PTR_S a6, PT_R10(sp)
>> 33 PTR_S a7, PT_R11(sp)
>> 34 #endif
24 .endm 35 .endm
25 36
26 .macro MCOUNT_RESTORE_REGS 37 .macro MCOUNT_RESTORE_REGS
27 move a0, s0 !! 38 PTR_L ra, PT_R31(sp)
28 PTR_L ra, sp, MCOUNT_RA_OFFS !! 39 PTR_L AT, PT_R1(sp)
29 PTR_L s0, sp, MCOUNT_S0_OFFS !! 40 PTR_L a0, PT_R4(sp)
30 PTR_ADDI sp, sp, MCOUNT_STACK_S !! 41 PTR_L a1, PT_R5(sp)
>> 42 PTR_L a2, PT_R6(sp)
>> 43 PTR_L a3, PT_R7(sp)
>> 44 #ifdef CONFIG_64BIT
>> 45 PTR_L a4, PT_R8(sp)
>> 46 PTR_L a5, PT_R9(sp)
>> 47 PTR_L a6, PT_R10(sp)
>> 48 PTR_L a7, PT_R11(sp)
>> 49 #endif
>> 50 PTR_ADDIU sp, PT_SIZE
31 .endm 51 .endm
32 52
33 SYM_FUNC_START(_mcount) !! 53 .macro RETURN_BACK
34 la.pcrel t1, ftrace_stub !! 54 jr ra
35 la.pcrel t2, ftrace_trace_funct !! 55 move ra, AT
36 PTR_L t2, t2, 0 !! 56 .endm
37 beq t1, t2, fgraph_trace <<
38 57
39 MCOUNT_SAVE_REGS !! 58 /*
>> 59 * The -mmcount-ra-address option of gcc 4.5 uses register $12 to pass
>> 60 * the location of the parent's return address.
>> 61 */
>> 62 #define MCOUNT_RA_ADDRESS_REG $12
40 63
41 move a0, ra !! 64 #ifdef CONFIG_DYNAMIC_FTRACE
42 move a1, s0 <<
43 jirl ra, t2, 0 <<
44 65
45 MCOUNT_RESTORE_REGS !! 66 NESTED(ftrace_caller, PT_SIZE, ra)
>> 67 .globl _mcount
>> 68 _mcount:
>> 69 b ftrace_stub
>> 70 #ifdef CONFIG_32BIT
>> 71 addiu sp,sp,8
>> 72 #else
>> 73 nop
>> 74 #endif
46 75
47 fgraph_trace: !! 76 /* When tracing is activated, it calls ftrace_caller+8 (aka here) */
48 #ifdef CONFIG_FUNCTION_GRAPH_TRACER !! 77 lw t1, function_trace_stop
49 la.pcrel t1, ftrace_stub !! 78 bnez t1, ftrace_stub
50 la.pcrel t3, ftrace_graph_retur !! 79 nop
51 PTR_L t3, t3, 0 !! 80
52 bne t1, t3, ftrace_graph_c !! 81 MCOUNT_SAVE_REGS
53 la.pcrel t1, ftrace_graph_entry !! 82 #ifdef KBUILD_MCOUNT_RA_ADDRESS
54 la.pcrel t3, ftrace_graph_entry !! 83 PTR_S MCOUNT_RA_ADDRESS_REG, PT_R12(sp)
55 PTR_L t3, t3, 0 <<
56 bne t1, t3, ftrace_graph_c <<
57 #endif 84 #endif
58 85
59 SYM_INNER_LABEL(ftrace_stub, SYM_L_GLOBAL) !! 86 move a0, ra /* arg1: self return address */
60 jr ra !! 87 .globl ftrace_call
>> 88 ftrace_call:
>> 89 nop /* a placeholder for the call to a real tracing function */
>> 90 move a1, AT /* arg2: parent's return address */
>> 91
61 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 92 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
62 SYM_INNER_LABEL(ftrace_graph_func, SYM_L_GLOBA !! 93 .globl ftrace_graph_call
63 bl ftrace_stub !! 94 ftrace_graph_call:
>> 95 nop
>> 96 nop
>> 97 #endif
>> 98
>> 99 MCOUNT_RESTORE_REGS
>> 100 .globl ftrace_stub
>> 101 ftrace_stub:
>> 102 RETURN_BACK
>> 103 END(ftrace_caller)
>> 104
>> 105 #else /* ! CONFIG_DYNAMIC_FTRACE */
>> 106
>> 107 NESTED(_mcount, PT_SIZE, ra)
>> 108 lw t1, function_trace_stop
>> 109 bnez t1, ftrace_stub
>> 110 nop
>> 111 PTR_LA t1, ftrace_stub
>> 112 PTR_L t2, ftrace_trace_function /* Prepare t2 for (1) */
>> 113 bne t1, t2, static_trace
>> 114 nop
>> 115
>> 116 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
>> 117 PTR_L t3, ftrace_graph_return
>> 118 bne t1, t3, ftrace_graph_caller
>> 119 nop
>> 120 PTR_LA t1, ftrace_graph_entry_stub
>> 121 PTR_L t3, ftrace_graph_entry
>> 122 bne t1, t3, ftrace_graph_caller
>> 123 nop
>> 124 #endif
>> 125 b ftrace_stub
>> 126 #ifdef CONFIG_32BIT
>> 127 addiu sp, sp, 8
>> 128 #else
>> 129 nop
64 #endif 130 #endif
65 SYM_FUNC_END(_mcount) !! 131
66 EXPORT_SYMBOL(_mcount) !! 132 static_trace:
>> 133 MCOUNT_SAVE_REGS
>> 134
>> 135 move a0, ra /* arg1: self return address */
>> 136 jalr t2 /* (1) call *ftrace_trace_function */
>> 137 move a1, AT /* arg2: parent's return address */
>> 138
>> 139 MCOUNT_RESTORE_REGS
>> 140 #ifdef CONFIG_32BIT
>> 141 addiu sp, sp, 8
>> 142 #endif
>> 143 .globl ftrace_stub
>> 144 ftrace_stub:
>> 145 RETURN_BACK
>> 146 END(_mcount)
>> 147
>> 148 #endif /* ! CONFIG_DYNAMIC_FTRACE */
67 149
68 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 150 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
69 SYM_FUNC_START(ftrace_graph_caller) !! 151
>> 152 NESTED(ftrace_graph_caller, PT_SIZE, ra)
>> 153 #ifndef CONFIG_DYNAMIC_FTRACE
70 MCOUNT_SAVE_REGS 154 MCOUNT_SAVE_REGS
>> 155 #endif
71 156
72 PTR_ADDI a0, ra, -4 !! 157 /* arg1: Get the location of the parent's return address */
73 PTR_ADDI a1, sp, MCOUNT_STACK_S !! 158 #ifdef KBUILD_MCOUNT_RA_ADDRESS
74 move a2, s0 !! 159 #ifdef CONFIG_DYNAMIC_FTRACE
75 bl prepare_ftrace_return !! 160 PTR_L a0, PT_R12(sp)
>> 161 #else
>> 162 move a0, MCOUNT_RA_ADDRESS_REG
>> 163 #endif
>> 164 bnez a0, 1f /* non-leaf func: stored in MCOUNT_RA_ADDRESS_REG */
>> 165 nop
>> 166 #endif
>> 167 PTR_LA a0, PT_R1(sp) /* leaf func: the location in current stack */
>> 168 1:
>> 169
>> 170 /* arg2: Get self return address */
>> 171 #ifdef CONFIG_DYNAMIC_FTRACE
>> 172 PTR_L a1, PT_R31(sp)
>> 173 #else
>> 174 move a1, ra
>> 175 #endif
76 176
>> 177 /* arg3: Get frame pointer of current stack */
>> 178 #ifdef CONFIG_FRAME_POINTER
>> 179 move a2, fp
>> 180 #else /* ! CONFIG_FRAME_POINTER */
>> 181 #ifdef CONFIG_64BIT
>> 182 PTR_LA a2, PT_SIZE(sp)
>> 183 #else
>> 184 PTR_LA a2, (PT_SIZE+8)(sp)
>> 185 #endif
>> 186 #endif
>> 187
>> 188 jal prepare_ftrace_return
>> 189 nop
77 MCOUNT_RESTORE_REGS 190 MCOUNT_RESTORE_REGS
78 jr ra !! 191 #ifndef CONFIG_DYNAMIC_FTRACE
79 SYM_FUNC_END(ftrace_graph_caller) !! 192 #ifdef CONFIG_32BIT
>> 193 addiu sp, sp, 8
>> 194 #endif
>> 195 #endif
>> 196 RETURN_BACK
>> 197 END(ftrace_graph_caller)
80 198
81 SYM_FUNC_START(return_to_handler) !! 199 .align 2
82 PTR_ADDI sp, sp, -FGRET_REGS_SI !! 200 .globl return_to_handler
83 PTR_S a0, sp, FGRET_REGS_A0 !! 201 return_to_handler:
84 PTR_S a1, sp, FGRET_REGS_A1 !! 202 PTR_SUBU sp, PT_SIZE
85 PTR_S zero, sp, FGRET_REGS_F !! 203 PTR_S v0, PT_R2(sp)
86 !! 204
87 move a0, sp !! 205 jal ftrace_return_to_handler
88 bl ftrace_return_to_handl !! 206 PTR_S v1, PT_R3(sp)
89 !! 207
90 /* Restore the real parent address: a0 !! 208 /* restore the real parent address: v0 -> ra */
91 move ra, a0 !! 209 move ra, v0
92 !! 210
93 PTR_L a0, sp, FGRET_REGS_A0 !! 211 PTR_L v0, PT_R2(sp)
94 PTR_L a1, sp, FGRET_REGS_A1 !! 212 PTR_L v1, PT_R3(sp)
95 PTR_ADDI sp, sp, FGRET_REGS_SIZ !! 213 jr ra
96 jr ra !! 214 PTR_ADDIU sp, PT_SIZE
97 SYM_FUNC_END(return_to_handler) <<
98 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 215 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
>> 216
>> 217 .set at
>> 218 .set reorder
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