1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _STATIC_CALL_TYPES_H
3#define _STATIC_CALL_TYPES_H
4
5#include <linux/types.h>
6#include <linux/stringify.h>
7#include <linux/compiler.h>
8
9#define STATIC_CALL_KEY_PREFIX __SCK__
10#define STATIC_CALL_KEY_PREFIX_STR __stringify(STATIC_CALL_KEY_PREFIX)
11#define STATIC_CALL_KEY_PREFIX_LEN (sizeof(STATIC_CALL_KEY_PREFIX_STR) - 1)
12#define STATIC_CALL_KEY(name) __PASTE(STATIC_CALL_KEY_PREFIX, name)
13#define STATIC_CALL_KEY_STR(name) __stringify(STATIC_CALL_KEY(name))
14
15#define STATIC_CALL_TRAMP_PREFIX __SCT__
16#define STATIC_CALL_TRAMP_PREFIX_STR __stringify(STATIC_CALL_TRAMP_PREFIX)
17#define STATIC_CALL_TRAMP_PREFIX_LEN (sizeof(STATIC_CALL_TRAMP_PREFIX_STR) - 1)
18#define STATIC_CALL_TRAMP(name) __PASTE(STATIC_CALL_TRAMP_PREFIX, name)
19#define STATIC_CALL_TRAMP_STR(name) __stringify(STATIC_CALL_TRAMP(name))
20
21/*
22 * Flags in the low bits of static_call_site::key.
23 */
24#define STATIC_CALL_SITE_TAIL 1UL /* tail call */
25#define STATIC_CALL_SITE_INIT 2UL /* init section */
26#define STATIC_CALL_SITE_FLAGS 3UL
27
28/*
29 * The static call site table needs to be created by external tooling (objtool
30 * or a compiler plugin).
31 */
32struct static_call_site {
33 s32 addr;
34 s32 key;
35};
36
37#define DECLARE_STATIC_CALL(name, func) \
38 extern struct static_call_key STATIC_CALL_KEY(name); \
39 extern typeof(func) STATIC_CALL_TRAMP(name);
40
41#ifdef CONFIG_HAVE_STATIC_CALL
42
43#define __raw_static_call(name) (&STATIC_CALL_TRAMP(name))
44
45#ifdef CONFIG_HAVE_STATIC_CALL_INLINE
46
47/*
48 * __ADDRESSABLE() is used to ensure the key symbol doesn't get stripped from
49 * the symbol table so that objtool can reference it when it generates the
50 * .static_call_sites section.
51 */
52#define __STATIC_CALL_ADDRESSABLE(name) \
53 __ADDRESSABLE(STATIC_CALL_KEY(name))
54
55#define __static_call(name) \
56({ \
57 __STATIC_CALL_ADDRESSABLE(name); \
58 __raw_static_call(name); \
59})
60
61struct static_call_key {
62 void *func;
63 union {
64 /* bit 0: 0 = mods, 1 = sites */
65 unsigned long type;
66 struct static_call_mod *mods;
67 struct static_call_site *sites;
68 };
69};
70
71#else /* !CONFIG_HAVE_STATIC_CALL_INLINE */
72
73#define __STATIC_CALL_ADDRESSABLE(name)
74#define __static_call(name) __raw_static_call(name)
75
76struct static_call_key {
77 void *func;
78};
79
80#endif /* CONFIG_HAVE_STATIC_CALL_INLINE */
81
82#ifdef MODULE
83#define __STATIC_CALL_MOD_ADDRESSABLE(name)
84#define static_call_mod(name) __raw_static_call(name)
85#else
86#define __STATIC_CALL_MOD_ADDRESSABLE(name) __STATIC_CALL_ADDRESSABLE(name)
87#define static_call_mod(name) __static_call(name)
88#endif
89
90#define static_call(name) __static_call(name)
91
92#else
93
94struct static_call_key {
95 void *func;
96};
97
98#define static_call(name) \
99 ((typeof(STATIC_CALL_TRAMP(name))*)(STATIC_CALL_KEY(name).func))
100
101#endif /* CONFIG_HAVE_STATIC_CALL */
102
103#endif /* _STATIC_CALL_TYPES_H */
104