| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. |
| 3 | |
| 4 | #include <linux/linkage.h> |
| 5 | #include <asm/ftrace.h> |
| 6 | #include <abi/entry.h> |
| 7 | #include <asm/asm-offsets.h> |
| 8 | |
| 9 | /* |
| 10 | * csky-gcc with -pg will put the following asm after prologue: |
| 11 | * push r15 |
| 12 | * jsri _mcount |
| 13 | * |
| 14 | * stack layout after mcount_enter in _mcount(): |
| 15 | * |
| 16 | * current sp => 0:+-------+ |
| 17 | * | a0-a3 | -> must save all argument regs |
| 18 | * +16:+-------+ |
| 19 | * | lr | -> _mcount lr (instrumente function's pc) |
| 20 | * +20:+-------+ |
| 21 | * | fp=r8 | -> instrumented function fp |
| 22 | * +24:+-------+ |
| 23 | * | plr | -> instrumented function lr (parent's pc) |
| 24 | * +-------+ |
| 25 | */ |
| 26 | |
| 27 | .macro mcount_enter |
| 28 | subi sp, 24 |
| 29 | stw a0, (sp, 0) |
| 30 | stw a1, (sp, 4) |
| 31 | stw a2, (sp, 8) |
| 32 | stw a3, (sp, 12) |
| 33 | stw lr, (sp, 16) |
| 34 | stw r8, (sp, 20) |
| 35 | .endm |
| 36 | |
| 37 | .macro mcount_exit |
| 38 | ldw a0, (sp, 0) |
| 39 | ldw a1, (sp, 4) |
| 40 | ldw a2, (sp, 8) |
| 41 | ldw a3, (sp, 12) |
| 42 | ldw t1, (sp, 16) |
| 43 | ldw r8, (sp, 20) |
| 44 | ldw lr, (sp, 24) |
| 45 | addi sp, 28 |
| 46 | jmp t1 |
| 47 | .endm |
| 48 | |
| 49 | .macro mcount_enter_regs |
| 50 | subi sp, 8 |
| 51 | stw lr, (sp, 0) |
| 52 | stw r8, (sp, 4) |
| 53 | SAVE_REGS_FTRACE |
| 54 | .endm |
| 55 | |
| 56 | .macro mcount_exit_regs |
| 57 | RESTORE_REGS_FTRACE |
| 58 | subi sp, 152 |
| 59 | ldw t1, (sp, 4) |
| 60 | addi sp, 152 |
| 61 | ldw r8, (sp, 4) |
| 62 | ldw lr, (sp, 8) |
| 63 | addi sp, 12 |
| 64 | jmp t1 |
| 65 | .endm |
| 66 | |
| 67 | .macro save_return_regs |
| 68 | subi sp, 16 |
| 69 | stw a0, (sp, 0) |
| 70 | stw a1, (sp, 4) |
| 71 | stw a2, (sp, 8) |
| 72 | stw a3, (sp, 12) |
| 73 | .endm |
| 74 | |
| 75 | .macro restore_return_regs |
| 76 | mov lr, a0 |
| 77 | ldw a0, (sp, 0) |
| 78 | ldw a1, (sp, 4) |
| 79 | ldw a2, (sp, 8) |
| 80 | ldw a3, (sp, 12) |
| 81 | addi sp, 16 |
| 82 | .endm |
| 83 | |
| 84 | .macro nop32_stub |
| 85 | nop32 |
| 86 | nop32 |
| 87 | nop32 |
| 88 | .endm |
| 89 | |
| 90 | ENTRY(ftrace_stub) |
| 91 | jmp lr |
| 92 | END(ftrace_stub) |
| 93 | |
| 94 | #ifndef CONFIG_DYNAMIC_FTRACE |
| 95 | ENTRY(_mcount) |
| 96 | mcount_enter |
| 97 | |
| 98 | /* r26 is link register, only used with jsri translation */ |
| 99 | lrw r26, ftrace_trace_function |
| 100 | ldw r26, (r26, 0) |
| 101 | lrw a1, ftrace_stub |
| 102 | cmpne r26, a1 |
| 103 | bf skip_ftrace |
| 104 | |
| 105 | mov a0, lr |
| 106 | subi a0, 4 |
| 107 | ldw a1, (sp, 24) |
| 108 | lrw a2, function_trace_op |
| 109 | ldw a2, (a2, 0) |
| 110 | |
| 111 | jsr r26 |
| 112 | |
| 113 | #ifndef CONFIG_FUNCTION_GRAPH_TRACER |
| 114 | skip_ftrace: |
| 115 | mcount_exit |
| 116 | #else |
| 117 | skip_ftrace: |
| 118 | lrw a0, ftrace_graph_return |
| 119 | ldw a0, (a0, 0) |
| 120 | lrw a1, ftrace_stub |
| 121 | cmpne a0, a1 |
| 122 | bt ftrace_graph_caller |
| 123 | |
| 124 | lrw a0, ftrace_graph_entry |
| 125 | ldw a0, (a0, 0) |
| 126 | lrw a1, ftrace_graph_entry_stub |
| 127 | cmpne a0, a1 |
| 128 | bt ftrace_graph_caller |
| 129 | |
| 130 | mcount_exit |
| 131 | #endif |
| 132 | END(_mcount) |
| 133 | #else /* CONFIG_DYNAMIC_FTRACE */ |
| 134 | ENTRY(_mcount) |
| 135 | mov t1, lr |
| 136 | ldw lr, (sp, 0) |
| 137 | addi sp, 4 |
| 138 | jmp t1 |
| 139 | ENDPROC(_mcount) |
| 140 | |
| 141 | ENTRY(ftrace_caller) |
| 142 | mcount_enter |
| 143 | |
| 144 | ldw a0, (sp, 16) |
| 145 | subi a0, 4 |
| 146 | ldw a1, (sp, 24) |
| 147 | lrw a2, function_trace_op |
| 148 | ldw a2, (a2, 0) |
| 149 | |
| 150 | nop |
| 151 | GLOBAL(ftrace_call) |
| 152 | nop32_stub |
| 153 | |
| 154 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| 155 | nop |
| 156 | GLOBAL(ftrace_graph_call) |
| 157 | nop32_stub |
| 158 | #endif |
| 159 | |
| 160 | mcount_exit |
| 161 | ENDPROC(ftrace_caller) |
| 162 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
| 163 | |
| 164 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| 165 | ENTRY(ftrace_graph_caller) |
| 166 | mov a0, sp |
| 167 | addi a0, 24 |
| 168 | ldw a1, (sp, 16) |
| 169 | subi a1, 4 |
| 170 | mov a2, r8 |
| 171 | lrw r26, prepare_ftrace_return |
| 172 | jsr r26 |
| 173 | mcount_exit |
| 174 | END(ftrace_graph_caller) |
| 175 | |
| 176 | ENTRY(return_to_handler) |
| 177 | save_return_regs |
| 178 | mov a0, r8 |
| 179 | jsri ftrace_return_to_handler |
| 180 | restore_return_regs |
| 181 | jmp lr |
| 182 | END(return_to_handler) |
| 183 | #endif |
| 184 | |
| 185 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
| 186 | ENTRY(ftrace_regs_caller) |
| 187 | mcount_enter_regs |
| 188 | |
| 189 | lrw t1, PT_FRAME_SIZE |
| 190 | add t1, sp |
| 191 | |
| 192 | ldw a0, (t1, 0) |
| 193 | subi a0, 4 |
| 194 | ldw a1, (t1, 8) |
| 195 | lrw a2, function_trace_op |
| 196 | ldw a2, (a2, 0) |
| 197 | mov a3, sp |
| 198 | |
| 199 | nop |
| 200 | GLOBAL(ftrace_regs_call) |
| 201 | nop32_stub |
| 202 | |
| 203 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| 204 | nop |
| 205 | GLOBAL(ftrace_graph_regs_call) |
| 206 | nop32_stub |
| 207 | #endif |
| 208 | |
| 209 | mcount_exit_regs |
| 210 | ENDPROC(ftrace_regs_caller) |
| 211 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
| 212 | |