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 |
52 | |