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 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 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) 32 stw r8, (sp, 20) 33.endm 34 35.macro mcount_exit 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) 41 ldw r8, (sp, 20) 42 ldw lr, (sp, 24) 43 addi sp, 28 44 jmp t1 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.macro nop32_stub 65 nop32 66 nop32 67 nop32 68.endm 69 70ENTRY(ftrace_stub) 71 jmp lr 72END(ftrace_stub) 73 74#ifndef CONFIG_DYNAMIC_FTRACE 75ENTRY(_mcount) 76 mcount_enter 77 78 /* r26 is link register, only used with jsri translation */ 79 lrw r26, ftrace_trace_function 80 ldw r26, (r26, 0) 81 lrw a1, ftrace_stub 82 cmpne r26, a1 83 bf skip_ftrace 84 85 mov a0, lr 86 subi a0, 4 87 ldw a1, (sp, 24) 88 89 jsr r26 90 91#ifndef CONFIG_FUNCTION_GRAPH_TRACER 92skip_ftrace: 93 mcount_exit 94#else 95skip_ftrace: 96 lrw a0, ftrace_graph_return 97 ldw a0, (a0, 0) 98 lrw a1, ftrace_stub 99 cmpne a0, a1 100 bt ftrace_graph_caller 101 102 lrw a0, ftrace_graph_entry 103 ldw a0, (a0, 0) 104 lrw a1, ftrace_graph_entry_stub 105 cmpne a0, a1 106 bt ftrace_graph_caller 107 108 mcount_exit 109#endif 110END(_mcount) 111#else /* CONFIG_DYNAMIC_FTRACE */ 112ENTRY(_mcount) 113 mov t1, lr 114 ldw lr, (sp, 0) 115 addi sp, 4 116 jmp t1 117ENDPROC(_mcount) 118 119ENTRY(ftrace_caller) 120 mcount_enter 121 122 ldw a0, (sp, 16) 123 subi a0, 4 124 ldw a1, (sp, 24) 125 126 nop 127GLOBAL(ftrace_call) 128 nop32_stub 129 130#ifdef CONFIG_FUNCTION_GRAPH_TRACER 131 nop 132GLOBAL(ftrace_graph_call) 133 nop32_stub 134#endif 135 136 mcount_exit 137ENDPROC(ftrace_caller) 138#endif /* CONFIG_DYNAMIC_FTRACE */ 139 140#ifdef CONFIG_FUNCTION_GRAPH_TRACER 141ENTRY(ftrace_graph_caller) 142 mov a0, sp 143 addi a0, 24 144 ldw a1, (sp, 16) 145 subi a1, 4 146 mov a2, r8 147 lrw r26, prepare_ftrace_return 148 jsr r26 149 mcount_exit 150END(ftrace_graph_caller) 151 152ENTRY(return_to_handler) 153 save_return_regs 154 mov a0, r8 155 jsri ftrace_return_to_handler 156 restore_return_regs 157 jmp lr 158END(return_to_handler) 159#endif 160