1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com)
4 *
5 * This file implements mcount(), which is used to collect profiling data.
6 * This can also be tweaked for kernel stack overflow detection.
7 */
8
9#include <linux/export.h>
10#include <linux/linkage.h>
11
12/*
13 * This is the main variant and is called by C code. GCC's -pg option
14 * automatically instruments every C function with a call to this.
15 */
16
17 .text
18 .align 32
19 .globl _mcount
20 .type _mcount,#function
21 EXPORT_SYMBOL(_mcount)
22 .globl mcount
23 .type mcount,#function
24_mcount:
25mcount:
26#ifdef CONFIG_FUNCTION_TRACER
27#ifdef CONFIG_DYNAMIC_FTRACE
28 /* Do nothing, the retl/nop below is all we need. */
29#else
30 sethi %hi(ftrace_trace_function), %g1
31 sethi %hi(ftrace_stub), %g2
32 ldx [%g1 + %lo(ftrace_trace_function)], %g1
33 or %g2, %lo(ftrace_stub), %g2
34 cmp %g1, %g2
35 be,pn %icc, 1f
36 mov %i7, %g3
37 save %sp, -176, %sp
38 mov %g3, %o1
39 jmpl %g1, %o7
40 mov %i7, %o0
41 ret
42 restore
43 /* not reached */
441:
45#ifdef CONFIG_FUNCTION_GRAPH_TRACER
46 sethi %hi(ftrace_graph_return), %g1
47 ldx [%g1 + %lo(ftrace_graph_return)], %g3
48 cmp %g2, %g3
49 bne,pn %xcc, 5f
50 sethi %hi(ftrace_graph_entry_stub), %g2
51 sethi %hi(ftrace_graph_entry), %g1
52 or %g2, %lo(ftrace_graph_entry_stub), %g2
53 ldx [%g1 + %lo(ftrace_graph_entry)], %g1
54 cmp %g1, %g2
55 be,pt %xcc, 2f
56 nop
575: mov %i7, %g2
58 mov %fp, %g3
59 save %sp, -176, %sp
60 mov %g2, %l0
61 ba,pt %xcc, ftrace_graph_caller
62 mov %g3, %l1
63#endif
642:
65#endif
66#endif
67 retl
68 nop
69 .size _mcount,.-_mcount
70 .size mcount,.-mcount
71
72#ifdef CONFIG_FUNCTION_TRACER
73 .globl ftrace_stub
74 .type ftrace_stub,#function
75ftrace_stub:
76 retl
77 nop
78 .size ftrace_stub,.-ftrace_stub
79#ifdef CONFIG_DYNAMIC_FTRACE
80 .globl ftrace_caller
81 .type ftrace_caller,#function
82ftrace_caller:
83 mov %i7, %g2
84 mov %fp, %g3
85 save %sp, -176, %sp
86 mov %g2, %o1
87 mov %g2, %l0
88 mov %g3, %l1
89 .globl ftrace_call
90ftrace_call:
91 call ftrace_stub
92 mov %i7, %o0
93#ifdef CONFIG_FUNCTION_GRAPH_TRACER
94 .globl ftrace_graph_call
95ftrace_graph_call:
96 call ftrace_stub
97 nop
98#endif
99 ret
100 restore
101#ifdef CONFIG_FUNCTION_GRAPH_TRACER
102 .size ftrace_graph_call,.-ftrace_graph_call
103#endif
104 .size ftrace_call,.-ftrace_call
105 .size ftrace_caller,.-ftrace_caller
106#endif
107#endif
108
109#ifdef CONFIG_FUNCTION_GRAPH_TRACER
110ENTRY(ftrace_graph_caller)
111 mov %l0, %o0
112 mov %i7, %o1
113 call prepare_ftrace_return
114 mov %l1, %o2
115 ret
116 restore %o0, -8, %i7
117END(ftrace_graph_caller)
118
119ENTRY(return_to_handler)
120 save %sp, -176, %sp
121 call ftrace_return_to_handler
122 mov %fp, %o0
123 jmpl %o0 + 8, %g0
124 restore
125END(return_to_handler)
126#endif
127

source code of linux/arch/sparc/lib/mcount.S