Linux kernel mirror (for testing)
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_INDIRECT_CALL_WRAPPER_H
3#define _LINUX_INDIRECT_CALL_WRAPPER_H
4
5#ifdef CONFIG_RETPOLINE
6
7/*
8 * INDIRECT_CALL_$NR - wrapper for indirect calls with $NR known builtin
9 * @f: function pointer
10 * @f$NR: builtin functions names, up to $NR of them
11 * @__VA_ARGS__: arguments for @f
12 *
13 * Avoid retpoline overhead for known builtin, checking @f vs each of them and
14 * eventually invoking directly the builtin function. The functions are check
15 * in the given order. Fallback to the indirect call.
16 */
17#define INDIRECT_CALL_1(f, f1, ...) \
18 ({ \
19 likely(f == f1) ? f1(__VA_ARGS__) : f(__VA_ARGS__); \
20 })
21#define INDIRECT_CALL_2(f, f2, f1, ...) \
22 ({ \
23 likely(f == f2) ? f2(__VA_ARGS__) : \
24 INDIRECT_CALL_1(f, f1, __VA_ARGS__); \
25 })
26
27#define INDIRECT_CALLABLE_DECLARE(f) f
28#define INDIRECT_CALLABLE_SCOPE
29
30#else
31#define INDIRECT_CALL_1(f, f1, ...) f(__VA_ARGS__)
32#define INDIRECT_CALL_2(f, f2, f1, ...) f(__VA_ARGS__)
33#define INDIRECT_CALLABLE_DECLARE(f)
34#define INDIRECT_CALLABLE_SCOPE static
35#endif
36
37/*
38 * We can use INDIRECT_CALL_$NR for ipv6 related functions only if ipv6 is
39 * builtin, this macro simplify dealing with indirect calls with only ipv4/ipv6
40 * alternatives
41 */
42#if IS_BUILTIN(CONFIG_IPV6)
43#define INDIRECT_CALL_INET(f, f2, f1, ...) \
44 INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__)
45#elif IS_ENABLED(CONFIG_INET)
46#define INDIRECT_CALL_INET(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__)
47#else
48#define INDIRECT_CALL_INET(f, f2, f1, ...) f(__VA_ARGS__)
49#endif
50
51#endif