1 /* SPDX-License-Identifier: GPL-2.0 */ !! 1 /*
2 /* Copyright (C) 2017 Andes Technology Corpora !! 2 * MIPS specific _mcount support
>> 3 *
>> 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>
>> 11 */
3 12
4 #include <linux/init.h> <<
5 #include <linux/linkage.h> <<
6 #include <linux/cfi_types.h> <<
7 #include <linux/export.h> 13 #include <linux/export.h>
8 #include <asm/asm.h> !! 14 #include <asm/regdef.h>
9 #include <asm/csr.h> !! 15 #include <asm/stackframe.h>
10 #include <asm/unistd.h> <<
11 #include <asm/thread_info.h> <<
12 #include <asm/asm-offsets.h> <<
13 #include <asm/ftrace.h> 16 #include <asm/ftrace.h>
14 17
15 .text 18 .text
>> 19 .set noreorder
>> 20 .set noat
16 21
17 .macro SAVE_ABI_STATE !! 22 .macro MCOUNT_SAVE_REGS
18 addi sp, sp, -16 !! 23 PTR_SUBU sp, PT_SIZE
19 REG_S s0, 0*SZREG(sp) !! 24 PTR_S ra, PT_R31(sp)
20 REG_S ra, 1*SZREG(sp) !! 25 PTR_S AT, PT_R1(sp)
21 addi s0, sp, 16 !! 26 PTR_S a0, PT_R4(sp)
>> 27 PTR_S a1, PT_R5(sp)
>> 28 PTR_S a2, PT_R6(sp)
>> 29 PTR_S a3, PT_R7(sp)
>> 30 #ifdef CONFIG_64BIT
>> 31 PTR_S a4, PT_R8(sp)
>> 32 PTR_S a5, PT_R9(sp)
>> 33 PTR_S a6, PT_R10(sp)
>> 34 PTR_S a7, PT_R11(sp)
>> 35 #endif
22 .endm 36 .endm
23 37
24 /* !! 38 .macro MCOUNT_RESTORE_REGS
25 * The call to ftrace_return_to_handle !! 39 PTR_L ra, PT_R31(sp)
26 * register if a0 was not saved. !! 40 PTR_L AT, PT_R1(sp)
27 */ !! 41 PTR_L a0, PT_R4(sp)
28 .macro SAVE_RET_ABI_STATE !! 42 PTR_L a1, PT_R5(sp)
29 addi sp, sp, -4*SZREG !! 43 PTR_L a2, PT_R6(sp)
30 REG_S s0, 2*SZREG(sp) !! 44 PTR_L a3, PT_R7(sp)
31 REG_S ra, 3*SZREG(sp) !! 45 #ifdef CONFIG_64BIT
32 REG_S a0, 1*SZREG(sp) !! 46 PTR_L a4, PT_R8(sp)
33 REG_S a1, 0*SZREG(sp) !! 47 PTR_L a5, PT_R9(sp)
34 addi s0, sp, 4*SZREG !! 48 PTR_L a6, PT_R10(sp)
>> 49 PTR_L a7, PT_R11(sp)
>> 50 #endif
>> 51 PTR_ADDIU sp, PT_SIZE
35 .endm 52 .endm
36 53
37 .macro RESTORE_ABI_STATE !! 54 .macro RETURN_BACK
38 REG_L ra, 1*SZREG(sp) !! 55 jr ra
39 REG_L s0, 0*SZREG(sp) !! 56 move ra, AT
40 addi sp, sp, 16 <<
41 .endm 57 .endm
42 58
43 .macro RESTORE_RET_ABI_STATE !! 59 /*
44 REG_L ra, 3*SZREG(sp) !! 60 * The -mmcount-ra-address option of gcc 4.5 uses register $12 to pass
45 REG_L s0, 2*SZREG(sp) !! 61 * the location of the parent's return address.
46 REG_L a0, 1*SZREG(sp) !! 62 */
47 REG_L a1, 0*SZREG(sp) !! 63 #define MCOUNT_RA_ADDRESS_REG $12
48 addi sp, sp, 4*SZREG <<
49 .endm <<
50 64
51 SYM_TYPED_FUNC_START(ftrace_stub) <<
52 #ifdef CONFIG_DYNAMIC_FTRACE 65 #ifdef CONFIG_DYNAMIC_FTRACE
53 .global _mcount !! 66
54 .set _mcount, ftrace_stub !! 67 NESTED(ftrace_caller, PT_SIZE, ra)
55 #endif !! 68 .globl _mcount
56 ret !! 69 _mcount:
57 SYM_FUNC_END(ftrace_stub) !! 70 EXPORT_SYMBOL(_mcount)
>> 71 b ftrace_stub
>> 72 #ifdef CONFIG_32BIT
>> 73 addiu sp,sp,8
>> 74 #else
>> 75 nop
>> 76 #endif
>> 77
>> 78 /* When tracing is activated, it calls ftrace_caller+8 (aka here) */
>> 79 MCOUNT_SAVE_REGS
>> 80 #ifdef KBUILD_MCOUNT_RA_ADDRESS
>> 81 PTR_S MCOUNT_RA_ADDRESS_REG, PT_R12(sp)
>> 82 #endif
>> 83
>> 84 PTR_SUBU a0, ra, 8 /* arg1: self address */
>> 85 PTR_LA t1, _stext
>> 86 sltu t2, a0, t1 /* t2 = (a0 < _stext) */
>> 87 PTR_LA t1, _etext
>> 88 sltu t3, t1, a0 /* t3 = (a0 > _etext) */
>> 89 or t1, t2, t3
>> 90 beqz t1, ftrace_call
>> 91 nop
>> 92 #if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT)
>> 93 PTR_SUBU a0, a0, 16 /* arg1: adjust to module's recorded callsite */
>> 94 #else
>> 95 PTR_SUBU a0, a0, 12
>> 96 #endif
>> 97
>> 98 .globl ftrace_call
>> 99 ftrace_call:
>> 100 nop /* a placeholder for the call to a real tracing function */
>> 101 move a1, AT /* arg2: parent's return address */
58 102
59 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 103 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
60 SYM_TYPED_FUNC_START(ftrace_stub_graph) !! 104 .globl ftrace_graph_call
61 ret !! 105 ftrace_graph_call:
62 SYM_FUNC_END(ftrace_stub_graph) !! 106 nop
>> 107 nop
>> 108 #endif
63 109
64 SYM_FUNC_START(return_to_handler) !! 110 MCOUNT_RESTORE_REGS
65 /* !! 111 .globl ftrace_stub
66 * On implementing the frame point test, the i !! 112 ftrace_stub:
67 * s0 (frame pointer, if enabled) on entry and !! 113 RETURN_BACK
68 * However, the psABI of variable-length-argum !! 114 END(ftrace_caller)
69 * !! 115
70 * So alternatively we check the *old* frame p !! 116 #else /* ! CONFIG_DYNAMIC_FTRACE */
71 * value stored in -16(s0) on entry, and the s !! 117
72 */ !! 118 NESTED(_mcount, PT_SIZE, ra)
73 SAVE_RET_ABI_STATE !! 119 EXPORT_SYMBOL(_mcount)
74 mv a0, sp !! 120 PTR_LA t1, ftrace_stub
75 call ftrace_return_to_handler !! 121 PTR_L t2, ftrace_trace_function /* Prepare t2 for (1) */
76 mv a2, a0 !! 122 beq t1, t2, fgraph_trace
77 RESTORE_RET_ABI_STATE !! 123 nop
78 jalr a2 !! 124
79 SYM_FUNC_END(return_to_handler) !! 125 MCOUNT_SAVE_REGS
>> 126
>> 127 move a0, ra /* arg1: self return address */
>> 128 jalr t2 /* (1) call *ftrace_trace_function */
>> 129 move a1, AT /* arg2: parent's return address */
>> 130
>> 131 MCOUNT_RESTORE_REGS
>> 132
>> 133 fgraph_trace:
>> 134 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
>> 135 PTR_LA t1, ftrace_stub
>> 136 PTR_L t3, ftrace_graph_return
>> 137 bne t1, t3, ftrace_graph_caller
>> 138 nop
>> 139 PTR_LA t1, ftrace_graph_entry_stub
>> 140 PTR_L t3, ftrace_graph_entry
>> 141 bne t1, t3, ftrace_graph_caller
>> 142 nop
80 #endif 143 #endif
81 144
82 #ifndef CONFIG_DYNAMIC_FTRACE !! 145 #ifdef CONFIG_32BIT
83 SYM_FUNC_START(_mcount) !! 146 addiu sp, sp, 8
84 la t4, ftrace_stub !! 147 #endif
85 #ifdef CONFIG_FUNCTION_GRAPH_TRACER !! 148
86 la t0, ftrace_graph_return !! 149 .globl ftrace_stub
87 REG_L t1, 0(t0) !! 150 ftrace_stub:
88 bne t1, t4, .Ldo_ftrace_graph_call !! 151 RETURN_BACK
89 !! 152 END(_mcount)
90 la t3, ftrace_graph_entry !! 153
91 REG_L t2, 0(t3) !! 154 #endif /* ! CONFIG_DYNAMIC_FTRACE */
92 la t6, ftrace_graph_entry_stub <<
93 bne t2, t6, .Ldo_ftrace_graph_call <<
94 #endif <<
95 la t3, ftrace_trace_function <<
96 REG_L t5, 0(t3) <<
97 bne t5, t4, .Ldo_trace <<
98 ret <<
99 155
100 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 156 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
101 /* !! 157
102 * A pseudo representation for the function gr !! 158 NESTED(ftrace_graph_caller, PT_SIZE, ra)
103 * prepare_to_return(&ra_to_caller_of_caller, !! 159 #ifndef CONFIG_DYNAMIC_FTRACE
104 */ !! 160 MCOUNT_SAVE_REGS
105 .Ldo_ftrace_graph_caller: <<
106 addi a0, s0, -SZREG <<
107 mv a1, ra <<
108 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST <<
109 REG_L a2, -2*SZREG(s0) <<
110 #endif <<
111 SAVE_ABI_STATE <<
112 call prepare_ftrace_return <<
113 RESTORE_ABI_STATE <<
114 ret <<
115 #endif 161 #endif
116 162
117 /* !! 163 /* arg1: Get the location of the parent's return address */
118 * A pseudo representation for the function tr !! 164 #ifdef KBUILD_MCOUNT_RA_ADDRESS
119 * (*ftrace_trace_function)(ra_to_caller, ra_t !! 165 #ifdef CONFIG_DYNAMIC_FTRACE
120 */ !! 166 PTR_L a0, PT_R12(sp)
121 .Ldo_trace: !! 167 #else
122 REG_L a1, -SZREG(s0) !! 168 move a0, MCOUNT_RA_ADDRESS_REG
123 mv a0, ra <<
124 <<
125 SAVE_ABI_STATE <<
126 jalr t5 <<
127 RESTORE_ABI_STATE <<
128 ret <<
129 SYM_FUNC_END(_mcount) <<
130 #endif 169 #endif
131 EXPORT_SYMBOL(_mcount) !! 170 bnez a0, 1f /* non-leaf func: stored in MCOUNT_RA_ADDRESS_REG */
>> 171 nop
>> 172 #endif
>> 173 PTR_LA a0, PT_R1(sp) /* leaf func: the location in current stack */
>> 174 1:
>> 175
>> 176 /* arg2: Get self return address */
>> 177 #ifdef CONFIG_DYNAMIC_FTRACE
>> 178 PTR_L a1, PT_R31(sp)
>> 179 #else
>> 180 move a1, ra
>> 181 #endif
>> 182
>> 183 /* arg3: Get frame pointer of current stack */
>> 184 #ifdef CONFIG_64BIT
>> 185 PTR_LA a2, PT_SIZE(sp)
>> 186 #else
>> 187 PTR_LA a2, (PT_SIZE+8)(sp)
>> 188 #endif
>> 189
>> 190 jal prepare_ftrace_return
>> 191 nop
>> 192 MCOUNT_RESTORE_REGS
>> 193 #ifndef CONFIG_DYNAMIC_FTRACE
>> 194 #ifdef CONFIG_32BIT
>> 195 addiu sp, sp, 8
>> 196 #endif
>> 197 #endif
>> 198 RETURN_BACK
>> 199 END(ftrace_graph_caller)
>> 200
>> 201 .align 2
>> 202 .globl return_to_handler
>> 203 return_to_handler:
>> 204 PTR_SUBU sp, PT_SIZE
>> 205 PTR_S v0, PT_R2(sp)
>> 206
>> 207 jal ftrace_return_to_handler
>> 208 PTR_S v1, PT_R3(sp)
>> 209
>> 210 /* restore the real parent address: v0 -> ra */
>> 211 move ra, v0
>> 212
>> 213 PTR_L v0, PT_R2(sp)
>> 214 PTR_L v1, PT_R3(sp)
>> 215 jr ra
>> 216 PTR_ADDIU sp, PT_SIZE
>> 217 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
>> 218
>> 219 .set at
>> 220 .set reorder
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