1/* 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 * Author: Wu Zhangjin <wuzj@lemote.com> 10 */ 11 12#include <asm/regdef.h> 13#include <asm/stackframe.h> 14#include <asm/ftrace.h> 15 16 .text 17 .set noreorder 18 .set noat 19 20 .macro MCOUNT_SAVE_REGS 21 PTR_SUBU sp, PT_SIZE 22 PTR_S ra, PT_R31(sp) 23 PTR_S AT, PT_R1(sp) 24 PTR_S a0, PT_R4(sp) 25 PTR_S a1, PT_R5(sp) 26 PTR_S a2, PT_R6(sp) 27 PTR_S a3, PT_R7(sp) 28#ifdef CONFIG_64BIT 29 PTR_S a4, PT_R8(sp) 30 PTR_S a5, PT_R9(sp) 31 PTR_S a6, PT_R10(sp) 32 PTR_S a7, PT_R11(sp) 33#endif 34 .endm 35 36 .macro MCOUNT_RESTORE_REGS 37 PTR_L ra, PT_R31(sp) 38 PTR_L AT, PT_R1(sp) 39 PTR_L a0, PT_R4(sp) 40 PTR_L a1, PT_R5(sp) 41 PTR_L a2, PT_R6(sp) 42 PTR_L a3, PT_R7(sp) 43#ifdef CONFIG_64BIT 44 PTR_L a4, PT_R8(sp) 45 PTR_L a5, PT_R9(sp) 46 PTR_L a6, PT_R10(sp) 47 PTR_L a7, PT_R11(sp) 48#endif 49#ifdef CONFIG_64BIT 50 PTR_ADDIU sp, PT_SIZE 51#else 52 PTR_ADDIU sp, (PT_SIZE + 8) 53#endif 54.endm 55 56 .macro RETURN_BACK 57 jr ra 58 move ra, AT 59 .endm 60 61#ifdef CONFIG_DYNAMIC_FTRACE 62 63NESTED(ftrace_caller, PT_SIZE, ra) 64 .globl _mcount 65_mcount: 66 b ftrace_stub 67 nop 68 lw t0, function_trace_stop 69 bnez t0, ftrace_stub 70 nop 71 72 MCOUNT_SAVE_REGS 73 74 move a0, ra /* arg1: next ip, selfaddr */ 75 .globl ftrace_call 76ftrace_call: 77 nop /* a placeholder for the call to a real tracing function */ 78 move a1, AT /* arg2: the caller's next ip, parent */ 79 80#ifdef CONFIG_FUNCTION_GRAPH_TRACER 81 .globl ftrace_graph_call 82ftrace_graph_call: 83 nop 84 nop 85#endif 86 87 MCOUNT_RESTORE_REGS 88 .globl ftrace_stub 89ftrace_stub: 90 RETURN_BACK 91 END(ftrace_caller) 92 93#else /* ! CONFIG_DYNAMIC_FTRACE */ 94 95NESTED(_mcount, PT_SIZE, ra) 96 lw t0, function_trace_stop 97 bnez t0, ftrace_stub 98 nop 99 PTR_LA t0, ftrace_stub 100 PTR_L t1, ftrace_trace_function /* Prepare t1 for (1) */ 101 bne t0, t1, static_trace 102 nop 103 104#ifdef CONFIG_FUNCTION_GRAPH_TRACER 105 PTR_L t2, ftrace_graph_return 106 bne t0, t2, ftrace_graph_caller 107 nop 108 PTR_LA t0, ftrace_graph_entry_stub 109 PTR_L t2, ftrace_graph_entry 110 bne t0, t2, ftrace_graph_caller 111 nop 112#endif 113 b ftrace_stub 114 nop 115 116static_trace: 117 MCOUNT_SAVE_REGS 118 119 move a0, ra /* arg1: next ip, selfaddr */ 120 jalr t1 /* (1) call *ftrace_trace_function */ 121 move a1, AT /* arg2: the caller's next ip, parent */ 122 123 MCOUNT_RESTORE_REGS 124 .globl ftrace_stub 125ftrace_stub: 126 RETURN_BACK 127 END(_mcount) 128 129#endif /* ! CONFIG_DYNAMIC_FTRACE */ 130 131#ifdef CONFIG_FUNCTION_GRAPH_TRACER 132 133NESTED(ftrace_graph_caller, PT_SIZE, ra) 134#ifdef CONFIG_DYNAMIC_FTRACE 135 PTR_L a1, PT_R31(sp) /* load the original ra from the stack */ 136#else 137 MCOUNT_SAVE_REGS 138 move a1, ra /* arg2: next ip, selfaddr */ 139#endif 140 PTR_LA a0, PT_R1(sp) /* arg1: &AT -> a0 */ 141 jal prepare_ftrace_return 142#ifdef CONFIG_FRAME_POINTER 143 move a2, fp /* arg3: frame pointer */ 144#else 145#ifdef CONFIG_64BIT 146 PTR_LA a2, PT_SIZE(sp) 147#else 148 PTR_LA a2, (PT_SIZE+8)(sp) 149#endif 150#endif 151 152 MCOUNT_RESTORE_REGS 153 RETURN_BACK 154 END(ftrace_graph_caller) 155 156 .align 2 157 .globl return_to_handler 158return_to_handler: 159 PTR_SUBU sp, PT_SIZE 160 PTR_S v0, PT_R2(sp) 161 162 jal ftrace_return_to_handler 163 PTR_S v1, PT_R3(sp) 164 165 /* restore the real parent address: v0 -> ra */ 166 move ra, v0 167 168 PTR_L v0, PT_R2(sp) 169 PTR_L v1, PT_R3(sp) 170 jr ra 171 PTR_ADDIU sp, PT_SIZE 172#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 173 174 .set at 175 .set reorder 176