| Guo Ren | 230c77a | 2018-12-09 14:29:59 +0800 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. |
| 3 | |
| 4 | #include <linux/linkage.h> |
| Guo Ren | d7950be | 2018-12-15 21:04:27 +0800 | [diff] [blame] | 5 | #include <asm/ftrace.h> |
| Guo Ren | 230c77a | 2018-12-09 14:29:59 +0800 | [diff] [blame] | 6 | |
| Guo Ren | d7950be | 2018-12-15 21:04:27 +0800 | [diff] [blame] | 7 | /* |
| 8 | * csky-gcc with -pg will put the following asm after prologue: |
| 9 | * push r15 |
| 10 | * jsri _mcount |
| 11 | * |
| 12 | * stack layout after mcount_enter in _mcount(): |
| 13 | * |
| 14 | * current sp => 0:+-------+ |
| 15 | * | a0-a3 | -> must save all argument regs |
| 16 | * +16:+-------+ |
| 17 | * | lr | -> _mcount lr (instrumente function's pc) |
| 18 | * +20:+-------+ |
| 19 | * | fp=r8 | -> instrumented function fp |
| 20 | * +24:+-------+ |
| 21 | * | plr | -> instrumented function lr (parent's pc) |
| 22 | * +-------+ |
| 23 | */ |
| 24 | |
| 25 | .macro mcount_enter |
| 26 | subi sp, 24 |
| Guo Ren | 230c77a | 2018-12-09 14:29:59 +0800 | [diff] [blame] | 27 | stw a0, (sp, 0) |
| 28 | stw a1, (sp, 4) |
| 29 | stw a2, (sp, 8) |
| 30 | stw a3, (sp, 12) |
| 31 | stw lr, (sp, 16) |
| Guo Ren | d7950be | 2018-12-15 21:04:27 +0800 | [diff] [blame] | 32 | stw r8, (sp, 20) |
| 33 | .endm |
| 34 | |
| 35 | .macro mcount_exit |
| Guo Ren | 230c77a | 2018-12-09 14:29:59 +0800 | [diff] [blame] | 36 | ldw a0, (sp, 0) |
| 37 | ldw a1, (sp, 4) |
| 38 | ldw a2, (sp, 8) |
| 39 | ldw a3, (sp, 12) |
| 40 | ldw t1, (sp, 16) |
| Guo Ren | d7950be | 2018-12-15 21:04:27 +0800 | [diff] [blame] | 41 | ldw r8, (sp, 20) |
| 42 | ldw lr, (sp, 24) |
| 43 | addi sp, 28 |
| Guo Ren | 230c77a | 2018-12-09 14:29:59 +0800 | [diff] [blame] | 44 | jmp t1 |
| Guo Ren | d7950be | 2018-12-15 21:04:27 +0800 | [diff] [blame] | 45 | .endm |
| 46 | |
| 47 | .macro save_return_regs |
| 48 | subi sp, 16 |
| 49 | stw a0, (sp, 0) |
| 50 | stw a1, (sp, 4) |
| 51 | stw a2, (sp, 8) |
| 52 | stw a3, (sp, 12) |
| 53 | .endm |
| 54 | |
| 55 | .macro restore_return_regs |
| 56 | mov lr, a0 |
| 57 | ldw a0, (sp, 0) |
| 58 | ldw a1, (sp, 4) |
| 59 | ldw a2, (sp, 8) |
| 60 | ldw a3, (sp, 12) |
| 61 | addi sp, 16 |
| 62 | .endm |
| 63 | |
| 64 | ENTRY(ftrace_stub) |
| 65 | jmp lr |
| 66 | END(ftrace_stub) |
| 67 | |
| 68 | ENTRY(_mcount) |
| 69 | mcount_enter |
| 70 | |
| 71 | /* r26 is link register, only used with jsri translation */ |
| 72 | lrw r26, ftrace_trace_function |
| 73 | ldw r26, (r26, 0) |
| 74 | lrw a1, ftrace_stub |
| 75 | cmpne r26, a1 |
| 76 | bf skip_ftrace |
| 77 | |
| 78 | mov a0, lr |
| 79 | subi a0, MCOUNT_INSN_SIZE |
| 80 | ldw a1, (sp, 24) |
| 81 | |
| 82 | jsr r26 |
| 83 | |
| 84 | #ifndef CONFIG_FUNCTION_GRAPH_TRACER |
| 85 | skip_ftrace: |
| 86 | mcount_exit |
| 87 | #else |
| 88 | skip_ftrace: |
| 89 | lrw a0, ftrace_graph_return |
| 90 | ldw a0, (a0, 0) |
| 91 | lrw a1, ftrace_stub |
| 92 | cmpne a0, a1 |
| 93 | bt ftrace_graph_caller |
| 94 | |
| 95 | lrw a0, ftrace_graph_entry |
| 96 | ldw a0, (a0, 0) |
| 97 | lrw a1, ftrace_graph_entry_stub |
| 98 | cmpne a0, a1 |
| 99 | bt ftrace_graph_caller |
| 100 | |
| 101 | mcount_exit |
| 102 | #endif |
| 103 | END(_mcount) |
| 104 | |
| 105 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| 106 | ENTRY(ftrace_graph_caller) |
| 107 | mov a0, sp |
| 108 | addi a0, 24 |
| 109 | ldw a1, (sp, 16) |
| 110 | subi a1, MCOUNT_INSN_SIZE |
| 111 | mov a2, r8 |
| 112 | lrw r26, prepare_ftrace_return |
| 113 | jsr r26 |
| 114 | mcount_exit |
| 115 | END(ftrace_graph_caller) |
| 116 | |
| 117 | ENTRY(return_to_handler) |
| 118 | save_return_regs |
| 119 | mov a0, r8 |
| 120 | jsri ftrace_return_to_handler |
| 121 | restore_return_regs |
| 122 | jmp lr |
| 123 | END(return_to_handler) |
| 124 | #endif |