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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_INDIRECT_CALL_WRAPPER_H
#define _LINUX_INDIRECT_CALL_WRAPPER_H
#ifdef CONFIG_RETPOLINE
/*
* INDIRECT_CALL_$NR - wrapper for indirect calls with $NR known builtin
* @f: function pointer
* @f$NR: builtin functions names, up to $NR of them
* @__VA_ARGS__: arguments for @f
*
* Avoid retpoline overhead for known builtin, checking @f vs each of them and
* eventually invoking directly the builtin function. The functions are check
* in the given order. Fallback to the indirect call.
*/
#define INDIRECT_CALL_1(f, f1, ...) \
({ \
likely(f == f1) ? f1(__VA_ARGS__) : f(__VA_ARGS__); \
})
#define INDIRECT_CALL_2(f, f2, f1, ...) \
({ \
likely(f == f2) ? f2(__VA_ARGS__) : \
INDIRECT_CALL_1(f, f1, __VA_ARGS__); \
})
#define INDIRECT_CALL_3(f, f3, f2, f1, ...) \
({ \
likely(f == f3) ? f3(__VA_ARGS__) : \
INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__); \
})
#define INDIRECT_CALL_4(f, f4, f3, f2, f1, ...) \
({ \
likely(f == f4) ? f4(__VA_ARGS__) : \
INDIRECT_CALL_3(f, f3, f2, f1, __VA_ARGS__); \
})
#define INDIRECT_CALLABLE_DECLARE(f) f
#define INDIRECT_CALLABLE_SCOPE
#else
#define INDIRECT_CALL_1(f, f1, ...) f(__VA_ARGS__)
#define INDIRECT_CALL_2(f, f2, f1, ...) f(__VA_ARGS__)
#define INDIRECT_CALL_3(f, f3, f2, f1, ...) f(__VA_ARGS__)
#define INDIRECT_CALL_4(f, f4, f3, f2, f1, ...) f(__VA_ARGS__)
#define INDIRECT_CALLABLE_DECLARE(f)
#define INDIRECT_CALLABLE_SCOPE static
#endif
/*
* We can use INDIRECT_CALL_$NR for ipv6 related functions only if ipv6 is
* builtin, this macro simplify dealing with indirect calls with only ipv4/ipv6
* alternatives
*/
#if IS_BUILTIN(CONFIG_IPV6)
#define INDIRECT_CALL_INET(f, f2, f1, ...) \
INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__)
#elif IS_ENABLED(CONFIG_INET)
#define INDIRECT_CALL_INET(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__)
#else
#define INDIRECT_CALL_INET(f, f2, f1, ...) f(__VA_ARGS__)
#endif
#endif
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