1 /*
2 * MIPS specific _mcount support
3 *
4 * This file is subject to the terms and condi
5 * License. See the file "COPYING" in the mai
6 * more details.
7 *
8 * Copyright (C) 2009 Lemote Inc. & DSLab, Lan
9 * Copyright (C) 2010 DSLab, Lanzhou Universit
10 * Author: Wu Zhangjin <wuzhangjin@gmail.com>
11 */
12
13 #include <linux/export.h>
14 #include <asm/regdef.h>
15 #include <asm/stackframe.h>
16 #include <asm/ftrace.h>
17
18 .text
19 .set noreorder
20 .set noat
21
22 .macro MCOUNT_SAVE_REGS
23 PTR_SUBU sp, PT_SIZE
24 PTR_S ra, PT_R31(sp)
25 PTR_S AT, PT_R1(sp)
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
36 .endm
37
38 .macro MCOUNT_RESTORE_REGS
39 PTR_L ra, PT_R31(sp)
40 PTR_L AT, PT_R1(sp)
41 PTR_L a0, PT_R4(sp)
42 PTR_L a1, PT_R5(sp)
43 PTR_L a2, PT_R6(sp)
44 PTR_L a3, PT_R7(sp)
45 #ifdef CONFIG_64BIT
46 PTR_L a4, PT_R8(sp)
47 PTR_L a5, PT_R9(sp)
48 PTR_L a6, PT_R10(sp)
49 PTR_L a7, PT_R11(sp)
50 #endif
51 PTR_ADDIU sp, PT_SIZE
52 .endm
53
54 .macro RETURN_BACK
55 jr ra
56 move ra, AT
57 .endm
58
59 /*
60 * The -mmcount-ra-address option of gcc 4.5 u
61 * the location of the parent's return address
62 */
63 #define MCOUNT_RA_ADDRESS_REG $12
64
65 #ifdef CONFIG_DYNAMIC_FTRACE
66
67 NESTED(ftrace_caller, PT_SIZE, ra)
68 .globl _mcount
69 _mcount:
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
79 MCOUNT_SAVE_REGS
80 #ifdef KBUILD_MCOUNT_RA_ADDRESS
81 PTR_S MCOUNT_RA_ADDRESS_REG, PT_R12(
82 #endif
83
84 PTR_SUBU a0, ra, 8 /* arg1: self
85 PTR_LA t1, _stext
86 sltu t2, a0, t1 /* t2 = (a0 <
87 PTR_LA t1, _etext
88 sltu t3, t1, a0 /* t3 = (a0 >
89 or t1, t2, t3
90 beqz t1, ftrace_call
91 nop
92 #if defined(KBUILD_MCOUNT_RA_ADDRESS) && defin
93 PTR_SUBU a0, a0, 16 /* arg1: adjus
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
101 move a1, AT /* arg2: paren
102
103 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
104 .globl ftrace_graph_call
105 ftrace_graph_call:
106 nop
107 nop
108 #endif
109
110 MCOUNT_RESTORE_REGS
111 .globl ftrace_stub
112 ftrace_stub:
113 RETURN_BACK
114 END(ftrace_caller)
115
116 #else /* ! CONFIG_DYNAMIC_FTRACE */
117
118 NESTED(_mcount, PT_SIZE, ra)
119 EXPORT_SYMBOL(_mcount)
120 PTR_LA t1, ftrace_stub
121 PTR_L t2, ftrace_trace_function /* P
122 beq t1, t2, fgraph_trace
123 nop
124
125 MCOUNT_SAVE_REGS
126
127 move a0, ra /* arg1: self
128 jalr t2 /* (1) call *f
129 move a1, AT /* arg2: paren
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
143 #endif
144
145 #ifdef CONFIG_32BIT
146 addiu sp, sp, 8
147 #endif
148
149 .globl ftrace_stub
150 ftrace_stub:
151 RETURN_BACK
152 END(_mcount)
153
154 #endif /* ! CONFIG_DYNAMIC_FTRACE */
155
156 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
157
158 NESTED(ftrace_graph_caller, PT_SIZE, ra)
159 #ifndef CONFIG_DYNAMIC_FTRACE
160 MCOUNT_SAVE_REGS
161 #endif
162
163 /* arg1: Get the location of the paren
164 #ifdef KBUILD_MCOUNT_RA_ADDRESS
165 #ifdef CONFIG_DYNAMIC_FTRACE
166 PTR_L a0, PT_R12(sp)
167 #else
168 move a0, MCOUNT_RA_ADDRESS_REG
169 #endif
170 bnez a0, 1f /* non-leaf func: stor
171 nop
172 #endif
173 PTR_LA a0, PT_R1(sp) /* leaf func:
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
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
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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