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 $NR of them 11 * @__VA_ARGS__: arguments for @f 12 * 13 * Avoid retpoline overhead for known builtin, checking @f vs each of them and 14 * eventually invoking directly the builtin function. The functions are check 15 * in the given order. Fallback to the indirect call. 16 */ 17 #define INDIRECT_CALL_1(f, f1, ...) \ 18 ({ \ 19 likely(f == f1) ? f1(__VA_ARGS__) : f(__VA_ARGS__); \ 20 }) 21 #define INDIRECT_CALL_2(f, f2, f1, ...) \ 22 ({ \ 23 likely(f == f2) ? f2(__VA_ARGS__) : \ 24 INDIRECT_CALL_1(f, f1, __VA_ARGS__); \ 25 }) 26 #define INDIRECT_CALL_3(f, f3, f2, f1, ...) \ 27 ({ \ 28 likely(f == f3) ? f3(__VA_ARGS__) : \ 29 INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__); \ 30 }) 31 #define INDIRECT_CALL_4(f, f4, f3, f2, f1, ...) \ 32 ({ \ 33 likely(f == f4) ? f4(__VA_ARGS__) : \ 34 INDIRECT_CALL_3(f, f3, f2, f1, __VA_ARGS__); \ 35 }) 36 37 #define INDIRECT_CALLABLE_DECLARE(f) f 38 #define INDIRECT_CALLABLE_SCOPE 39 40 #else 41 #define INDIRECT_CALL_1(f, f1, ...) f(__VA_ARGS__) 42 #define INDIRECT_CALL_2(f, f2, f1, ...) f(__VA_ARGS__) 43 #define INDIRECT_CALL_3(f, f3, f2, f1, ...) f(__VA_ARGS__) 44 #define INDIRECT_CALL_4(f, f4, f3, f2, f1, ...) f(__VA_ARGS__) 45 #define INDIRECT_CALLABLE_DECLARE(f) 46 #define INDIRECT_CALLABLE_SCOPE static 47 #endif 48 49 /* 50 * We can use INDIRECT_CALL_$NR for ipv6 related functions only if ipv6 is 51 * builtin, this macro simplify dealing with indirect calls with only ipv4/ipv6 52 * alternatives 53 */ 54 #if IS_BUILTIN(CONFIG_IPV6) 55 #define INDIRECT_CALL_INET(f, f2, f1, ...) \ 56 INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__) 57 #elif IS_ENABLED(CONFIG_INET) 58 #define INDIRECT_CALL_INET(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__) 59 #else 60 #define INDIRECT_CALL_INET(f, f2, f1, ...) f(__VA_ARGS__) 61 #endif 62 63 #endif 64
