1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ARCH_POWERPC_EXTABLE_H
3#define _ARCH_POWERPC_EXTABLE_H
4
5/*
6 * The exception table consists of pairs of relative addresses: the first is
7 * the address of an instruction that is allowed to fault, and the second is
8 * the address at which the program should continue.  No registers are
9 * modified, so it is entirely up to the continuation code to figure out what
10 * to do.
11 *
12 * All the routines below use bits of fixup code that are out of line with the
13 * main instruction path.  This means when everything is well, we don't even
14 * have to jump over them.  Further, they do not intrude on our cache or tlb
15 * entries.
16 */
17
18#define ARCH_HAS_RELATIVE_EXTABLE
19
20#ifndef __ASSEMBLY__
21
22struct exception_table_entry {
23	int insn;
24	int fixup;
25};
26
27static inline unsigned long extable_fixup(const struct exception_table_entry *x)
28{
29	return (unsigned long)&x->fixup + x->fixup;
30}
31
32#endif
33
34/*
35 * Helper macro for exception table entries
36 */
37#define EX_TABLE(_fault, _target)		\
38	stringify_in_c(.section __ex_table,"a";)\
39	stringify_in_c(.balign 4;)		\
40	stringify_in_c(.long (_fault) - . ;)	\
41	stringify_in_c(.long (_target) - . ;)	\
42	stringify_in_c(.previous)
43
44#endif
45