[mirror_ubuntu-hirsute-kernel.git] / include / linux / indirect_call_wrapper.h

/* 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_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_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
Commit	Line	Data
283c16a2 PA	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 $NR of them
	11	* @__VA_ARGS__: arguments for @f
	12	*
	13	* Avoid retpoline overhead for known builtin, checking @f vs each of them and
	14	* eventually invoking directly the builtin function. The functions are check
	15	* in the given order. Fallback to the indirect call.
	16	*/
	17	#define INDIRECT_CALL_1(f, f1, ...) \
	18	({ \
	19	likely(f == f1) ? f1(__VA_ARGS__) : f(__VA_ARGS__); \
	20	})
	21	#define INDIRECT_CALL_2(f, f2, f1, ...) \
	22	({ \
	23	likely(f == f2) ? f2(__VA_ARGS__) : \
	24	INDIRECT_CALL_1(f, f1, __VA_ARGS__); \
	25	})
	26
	27	#define INDIRECT_CALLABLE_DECLARE(f) f
	28	#define INDIRECT_CALLABLE_SCOPE
	29
	30	#else
c03b0358 PA	31	#define INDIRECT_CALL_1(f, f1, ...) f(__VA_ARGS__)
c03b0358 PA	32	#define INDIRECT_CALL_2(f, f2, f1, ...) f(__VA_ARGS__)
283c16a2 PA	33	#define INDIRECT_CALLABLE_DECLARE(f)
	34	#define INDIRECT_CALLABLE_SCOPE static
	35	#endif
	36
	37	/*
	38	* We can use INDIRECT_CALL_$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