1 /* 1 /*
2 * Low-level ftrace handling !! 2 * MIPS specific _mcount support
3 * 3 *
4 * Copyright (C) 2009 Michal Simek <monstr@mons !! 4 * This file is subject to the terms and conditions of the GNU General Public
5 * Copyright (C) 2009 PetaLogix !! 5 * License. See the file "COPYING" in the main directory of this archive for
>> 6 * more details.
6 * 7 *
7 * This file is subject to the terms and condi !! 8 * Copyright (C) 2009 Lemote Inc. & DSLab, Lanzhou University, China
8 * Public License. See the file COPYING in the !! 9 * Copyright (C) 2010 DSLab, Lanzhou University, China
9 * archive for more details. !! 10 * Author: Wu Zhangjin <wuzhangjin@gmail.com>
10 */ 11 */
11 12
12 #include <linux/linkage.h> !! 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 uses register $12 to pass
>> 61 * the location of the parent's return address.
>> 62 */
>> 63 #define MCOUNT_RA_ADDRESS_REG $12
13 64
14 #define NOALIGN_ENTRY(name) .globl name; n !! 65 #ifdef CONFIG_DYNAMIC_FTRACE
15 66
16 /* FIXME MS: I think that I don't need to save !! 67 NESTED(ftrace_caller, PT_SIZE, ra)
17 #define SAVE_REGS \ !! 68 .globl _mcount
18 addik r1, r1, -120; \ !! 69 _mcount:
19 swi r2, r1, 4; \ !! 70 EXPORT_SYMBOL(_mcount)
20 swi r3, r1, 8; \ !! 71 b ftrace_stub
21 swi r4, r1, 12; \ !! 72 #ifdef CONFIG_32BIT
22 swi r5, r1, 116; \ !! 73 addiu sp,sp,8
23 swi r6, r1, 16; \ !! 74 #else
24 swi r7, r1, 20; \ !! 75 nop
25 swi r8, r1, 24; \ !! 76 #endif
26 swi r9, r1, 28; \ !! 77
27 swi r10, r1, 32; \ !! 78 /* When tracing is activated, it calls ftrace_caller+8 (aka here) */
28 swi r11, r1, 36; \ !! 79 MCOUNT_SAVE_REGS
29 swi r12, r1, 40; \ !! 80 #ifdef KBUILD_MCOUNT_RA_ADDRESS
30 swi r13, r1, 44; \ !! 81 PTR_S MCOUNT_RA_ADDRESS_REG, PT_R12(sp)
31 swi r14, r1, 48; \ !! 82 #endif
32 swi r16, r1, 52; \ !! 83
33 swi r17, r1, 56; \ !! 84 PTR_SUBU a0, ra, 8 /* arg1: self address */
34 swi r18, r1, 60; \ !! 85 PTR_LA t1, _stext
35 swi r19, r1, 64; \ !! 86 sltu t2, a0, t1 /* t2 = (a0 < _stext) */
36 swi r20, r1, 68; \ !! 87 PTR_LA t1, _etext
37 swi r21, r1, 72; \ !! 88 sltu t3, t1, a0 /* t3 = (a0 > _etext) */
38 swi r22, r1, 76; \ !! 89 or t1, t2, t3
39 swi r23, r1, 80; \ !! 90 beqz t1, ftrace_call
40 swi r24, r1, 84; \ !! 91 nop
41 swi r25, r1, 88; \ !! 92 #if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT)
42 swi r26, r1, 92; \ !! 93 PTR_SUBU a0, a0, 16 /* arg1: adjust to module's recorded callsite */
43 swi r27, r1, 96; \ !! 94 #else
44 swi r28, r1, 100; \ !! 95 PTR_SUBU a0, a0, 12
45 swi r29, r1, 104; \ !! 96 #endif
46 swi r30, r1, 108; \ !! 97
47 swi r31, r1, 112; !! 98 .globl ftrace_call
48 !! 99 ftrace_call:
49 #define RESTORE_REGS \ !! 100 nop /* a placeholder for the call to a real tracing function */
50 lwi r2, r1, 4; \ !! 101 move a1, AT /* arg2: parent's return address */
51 lwi r3, r1, 8; \ <<
52 lwi r4, r1, 12; \ <<
53 lwi r5, r1, 116; \ <<
54 lwi r6, r1, 16; \ <<
55 lwi r7, r1, 20; \ <<
56 lwi r8, r1, 24; \ <<
57 lwi r9, r1, 28; \ <<
58 lwi r10, r1, 32; \ <<
59 lwi r11, r1, 36; \ <<
60 lwi r12, r1, 40; \ <<
61 lwi r13, r1, 44; \ <<
62 lwi r14, r1, 48; \ <<
63 lwi r16, r1, 52; \ <<
64 lwi r17, r1, 56; \ <<
65 lwi r18, r1, 60; \ <<
66 lwi r19, r1, 64; \ <<
67 lwi r20, r1, 68; \ <<
68 lwi r21, r1, 72; \ <<
69 lwi r22, r1, 76; \ <<
70 lwi r23, r1, 80; \ <<
71 lwi r24, r1, 84; \ <<
72 lwi r25, r1, 88; \ <<
73 lwi r26, r1, 92; \ <<
74 lwi r27, r1, 96; \ <<
75 lwi r28, r1, 100; \ <<
76 lwi r29, r1, 104; \ <<
77 lwi r30, r1, 108; \ <<
78 lwi r31, r1, 112; \ <<
79 addik r1, r1, 120; <<
80 <<
81 ENTRY(ftrace_stub) <<
82 rtsd r15, 8; <<
83 nop; <<
84 102
85 ENTRY(_mcount) <<
86 #ifdef CONFIG_DYNAMIC_FTRACE <<
87 ENTRY(ftrace_caller) <<
88 /* MS: It is just barrier which is rem <<
89 rtsd r15, 8 <<
90 nop <<
91 #endif /* CONFIG_DYNAMIC_FTRACE */ <<
92 SAVE_REGS <<
93 swi r15, r1, 0; <<
94 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 103 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
95 #ifndef CONFIG_DYNAMIC_FTRACE !! 104 .globl ftrace_graph_call
96 lwi r5, r0, ftrace_graph_return; !! 105 ftrace_graph_call:
97 addik r6, r0, ftrace_stub; /* asm im <<
98 cmpu r5, r5, r6; /* ftrace_graph_re <<
99 beqid r5, end_graph_tracer; <<
100 nop; <<
101 <<
102 lwi r6, r0, ftrace_graph_entry; <<
103 addik r5, r0, ftrace_graph_entry_stu <<
104 cmpu r5, r5, r6; /* ftrace_graph_en <<
105 beqid r5, end_graph_tracer; <<
106 nop; <<
107 #else /* CONFIG_DYNAMIC_FTRACE */ <<
108 NOALIGN_ENTRY(ftrace_call_graph) <<
109 /* MS: jump over graph function - repl <<
110 bri end_graph_tracer <<
111 #endif /* CONFIG_DYNAMIC_FTRACE */ <<
112 addik r5, r1, 120; /* MS: load paren <<
113 addik r6, r15, 0; /* MS: load curren <<
114 bralid r15, prepare_ftrace_return; <<
115 nop; <<
116 /* MS: graph was taken that's why - ca <<
117 brid end; <<
118 nop; <<
119 end_graph_tracer: <<
120 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ <<
121 #ifndef CONFIG_DYNAMIC_FTRACE <<
122 /* MS: test function trace if is taken <<
123 lwi r20, r0, ftrace_trace_function <<
124 addik r6, r0, ftrace_stub; <<
125 cmpu r5, r20, r6; /* ftrace_trace_f <<
126 beqid r5, end; /* MS: not taken -> j <<
127 nop; <<
128 #else /* CONFIG_DYNAMIC_FTRACE */ <<
129 NOALIGN_ENTRY(ftrace_call) <<
130 /* instruction for setup imm FUNC_part1, addik <<
131 nop 106 nop
132 nop !! 107 nop
133 #endif /* CONFIG_DYNAMIC_FTRACE */ !! 108 #endif
134 /* static normal trace */ !! 109
135 lwi r6, r1, 120; /* MS: load paren !! 110 MCOUNT_RESTORE_REGS
136 addik r5, r15, -4; /* MS: load curre !! 111 .globl ftrace_stub
137 /* MS: here is dependency on previous !! 112 ftrace_stub:
138 brald r15, r20; /* MS: jump to ftrac !! 113 RETURN_BACK
139 nop; !! 114 END(ftrace_caller)
140 end: !! 115
141 lwi r15, r1, 0; !! 116 #else /* ! CONFIG_DYNAMIC_FTRACE */
142 RESTORE_REGS !! 117
>> 118 NESTED(_mcount, PT_SIZE, ra)
>> 119 EXPORT_SYMBOL(_mcount)
>> 120 PTR_LA t1, ftrace_stub
>> 121 PTR_L t2, ftrace_trace_function /* Prepare t2 for (1) */
>> 122 beq t1, t2, fgraph_trace
>> 123 nop
>> 124
>> 125 MCOUNT_SAVE_REGS
>> 126
>> 127 move a0, ra /* arg1: self return address */
>> 128 jalr t2 /* (1) call *ftrace_trace_function */
>> 129 move a1, AT /* arg2: parent's return address */
>> 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)
143 153
144 rtsd r15, 8; /* MS: jump back */ !! 154 #endif /* ! CONFIG_DYNAMIC_FTRACE */
145 nop; <<
146 155
147 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 156 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
148 ENTRY(return_to_handler) !! 157
149 nop; /* MS: just barrier for rtsd r15, !! 158 NESTED(ftrace_graph_caller, PT_SIZE, ra)
150 nop; !! 159 #ifndef CONFIG_DYNAMIC_FTRACE
151 SAVE_REGS !! 160 MCOUNT_SAVE_REGS
152 swi r15, r1, 0; !! 161 #endif
153 !! 162
154 /* MS: find out returning address */ !! 163 /* arg1: Get the location of the parent's return address */
155 bralid r15, ftrace_return_to_handler; !! 164 #ifdef KBUILD_MCOUNT_RA_ADDRESS
156 nop; !! 165 #ifdef CONFIG_DYNAMIC_FTRACE
157 !! 166 PTR_L a0, PT_R12(sp)
158 /* MS: return value from ftrace_return !! 167 #else
159 * must be before restore regs because !! 168 move a0, MCOUNT_RA_ADDRESS_REG
160 addik r15, r3, 0; !! 169 #endif
161 RESTORE_REGS !! 170 bnez a0, 1f /* non-leaf func: stored in MCOUNT_RA_ADDRESS_REG */
162 !! 171 nop
163 rtsd r15, 8; /* MS: jump back */ !! 172 #endif
164 nop; !! 173 PTR_LA a0, PT_R1(sp) /* leaf func: the location in current stack */
165 #endif /* CONFIG_FUNCTION_TRACER */ !! 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 stack */
>> 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 -> ra */
>> 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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