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Diffstat (limited to 'arch/powerpc/include/asm/extable.h')
-rw-r--r-- | arch/powerpc/include/asm/extable.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/extable.h b/arch/powerpc/include/asm/extable.h new file mode 100644 index 0000000000..26ce2e5c0f --- /dev/null +++ b/arch/powerpc/include/asm/extable.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ARCH_POWERPC_EXTABLE_H +#define _ARCH_POWERPC_EXTABLE_H + +/* + * The exception table consists of pairs of relative addresses: the first is + * the address of an instruction that is allowed to fault, and the second is + * the address at which the program should continue. No registers are + * modified, so it is entirely up to the continuation code to figure out what + * to do. + * + * All the routines below use bits of fixup code that are out of line with the + * main instruction path. This means when everything is well, we don't even + * have to jump over them. Further, they do not intrude on our cache or tlb + * entries. + */ + +#define ARCH_HAS_RELATIVE_EXTABLE + +#ifndef __ASSEMBLY__ + +struct exception_table_entry { + int insn; + int fixup; +}; + +static inline unsigned long extable_fixup(const struct exception_table_entry *x) +{ + return (unsigned long)&x->fixup + x->fixup; +} + +#endif + +/* + * Helper macro for exception table entries + */ +#define EX_TABLE(_fault, _target) \ + stringify_in_c(.section __ex_table,"a";)\ + stringify_in_c(.balign 4;) \ + stringify_in_c(.long (_fault) - . ;) \ + stringify_in_c(.long (_target) - . ;) \ + stringify_in_c(.previous) + +#endif |