aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/mcount.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/kernel/mcount.S')
-rw-r--r--arch/mips/kernel/mcount.S189
1 files changed, 189 insertions, 0 deletions
diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S
new file mode 100644
index 000000000000..0a9cfdb271dd
--- /dev/null
+++ b/arch/mips/kernel/mcount.S
@@ -0,0 +1,189 @@
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 t1, function_trace_stop
69 bnez t1, ftrace_stub
70 nop
71
72 MCOUNT_SAVE_REGS
73#ifdef KBUILD_MCOUNT_RA_ADDRESS
74 PTR_S t0, PT_R12(sp) /* t0 saved the location of the return address(at) by -mmcount-ra-address */
75#endif
76
77 move a0, ra /* arg1: next ip, selfaddr */
78 .globl ftrace_call
79ftrace_call:
80 nop /* a placeholder for the call to a real tracing function */
81 move a1, AT /* arg2: the caller's next ip, parent */
82
83#ifdef CONFIG_FUNCTION_GRAPH_TRACER
84 .globl ftrace_graph_call
85ftrace_graph_call:
86 nop
87 nop
88#endif
89
90 MCOUNT_RESTORE_REGS
91 .globl ftrace_stub
92ftrace_stub:
93 RETURN_BACK
94 END(ftrace_caller)
95
96#else /* ! CONFIG_DYNAMIC_FTRACE */
97
98NESTED(_mcount, PT_SIZE, ra)
99 lw t1, function_trace_stop
100 bnez t1, ftrace_stub
101 nop
102 PTR_LA t1, ftrace_stub
103 PTR_L t2, ftrace_trace_function /* Prepare t2 for (1) */
104 bne t1, t2, static_trace
105 nop
106
107#ifdef CONFIG_FUNCTION_GRAPH_TRACER
108 PTR_L t3, ftrace_graph_return
109 bne t1, t3, ftrace_graph_caller
110 nop
111 PTR_LA t1, ftrace_graph_entry_stub
112 PTR_L t3, ftrace_graph_entry
113 bne t1, t3, ftrace_graph_caller
114 nop
115#endif
116 b ftrace_stub
117 nop
118
119static_trace:
120 MCOUNT_SAVE_REGS
121
122 move a0, ra /* arg1: next ip, selfaddr */
123 jalr t2 /* (1) call *ftrace_trace_function */
124 move a1, AT /* arg2: the caller's next ip, parent */
125
126 MCOUNT_RESTORE_REGS
127 .globl ftrace_stub
128ftrace_stub:
129 RETURN_BACK
130 END(_mcount)
131
132#endif /* ! CONFIG_DYNAMIC_FTRACE */
133
134#ifdef CONFIG_FUNCTION_GRAPH_TRACER
135
136NESTED(ftrace_graph_caller, PT_SIZE, ra)
137#ifdef CONFIG_DYNAMIC_FTRACE
138 PTR_L a1, PT_R31(sp) /* load the original ra from the stack */
139#ifdef KBUILD_MCOUNT_RA_ADDRESS
140 PTR_L t0, PT_R12(sp) /* load the original t0 from the stack */
141#endif
142#else
143 MCOUNT_SAVE_REGS
144 move a1, ra /* arg2: next ip, selfaddr */
145#endif
146
147#ifdef KBUILD_MCOUNT_RA_ADDRESS
148 bnez t0, 1f /* non-leaf func: t0 saved the location of the return address */
149 nop
150 PTR_LA t0, PT_R1(sp) /* leaf func: get the location of at(old ra) from our own stack */
1511: move a0, t0 /* arg1: the location of the return address */
152#else
153 PTR_LA a0, PT_R1(sp) /* arg1: &AT -> a0 */
154#endif
155 jal prepare_ftrace_return
156#ifdef CONFIG_FRAME_POINTER
157 move a2, fp /* arg3: frame pointer */
158#else
159#ifdef CONFIG_64BIT
160 PTR_LA a2, PT_SIZE(sp)
161#else
162 PTR_LA a2, (PT_SIZE+8)(sp)
163#endif
164#endif
165
166 MCOUNT_RESTORE_REGS
167 RETURN_BACK
168 END(ftrace_graph_caller)
169
170 .align 2
171 .globl return_to_handler
172return_to_handler:
173 PTR_SUBU sp, PT_SIZE
174 PTR_S v0, PT_R2(sp)
175
176 jal ftrace_return_to_handler
177 PTR_S v1, PT_R3(sp)
178
179 /* restore the real parent address: v0 -> ra */
180 move ra, v0
181
182 PTR_L v0, PT_R2(sp)
183 PTR_L v1, PT_R3(sp)
184 jr ra
185 PTR_ADDIU sp, PT_SIZE
186#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
187
188 .set at
189 .set reorder