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 22 struct exception_table_entry { 23 int insn; 24 int fixup; 25 }; 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 #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