xref: /linux/arch/s390/include/asm/extable.h (revision ebf68996de0ab250c5d520eb2291ab65643e9a1e)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __S390_EXTABLE_H
3 #define __S390_EXTABLE_H
4 /*
5  * The exception table consists of pairs of addresses: the first is the
6  * address of an instruction that is allowed to fault, and the second is
7  * the address at which the program should continue.  No registers are
8  * modified, so it is entirely up to the continuation code to figure out
9  * what to do.
10  *
11  * All the routines below use bits of fixup code that are out of line
12  * with the main instruction path.  This means when everything is well,
13  * we don't even have to jump over them.  Further, they do not intrude
14  * on our cache or tlb entries.
15  */
16 
17 struct exception_table_entry
18 {
19 	int insn, fixup;
20 };
21 
22 extern struct exception_table_entry *__start_dma_ex_table;
23 extern struct exception_table_entry *__stop_dma_ex_table;
24 
25 const struct exception_table_entry *s390_search_extables(unsigned long addr);
26 
27 static inline unsigned long extable_fixup(const struct exception_table_entry *x)
28 {
29 	return (unsigned long)&x->fixup + x->fixup;
30 }
31 
32 #define ARCH_HAS_RELATIVE_EXTABLE
33 
34 #endif
35