linuxdebug/arch/s390/include/asm/alternative-asm.h

57 lines
1.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_S390_ALTERNATIVE_ASM_H
#define _ASM_S390_ALTERNATIVE_ASM_H
#ifdef __ASSEMBLY__
/*
* Issue one struct alt_instr descriptor entry (need to put it into
* the section .altinstructions, see below). This entry contains
* enough information for the alternatives patching code to patch an
* instruction. See apply_alternatives().
*/
.macro alt_entry orig_start, orig_end, alt_start, alt_end, feature
.long \orig_start - .
.long \alt_start - .
.word \feature
.byte \orig_end - \orig_start
.org . - ( \orig_end - \orig_start ) + ( \alt_end - \alt_start )
.org . - ( \alt_end - \alt_start ) + ( \orig_end - \orig_start )
.endm
/*
* Define an alternative between two instructions. If @feature is
* present, early code in apply_alternatives() replaces @oldinstr with
* @newinstr.
*/
.macro ALTERNATIVE oldinstr, newinstr, feature
.pushsection .altinstr_replacement,"ax"
770: \newinstr
771: .popsection
772: \oldinstr
773: .pushsection .altinstructions,"a"
alt_entry 772b, 773b, 770b, 771b, \feature
.popsection
.endm
/*
* Define an alternative between two instructions. If @feature is
* present, early code in apply_alternatives() replaces @oldinstr with
* @newinstr.
*/
.macro ALTERNATIVE_2 oldinstr, newinstr1, feature1, newinstr2, feature2
.pushsection .altinstr_replacement,"ax"
770: \newinstr1
771: \newinstr2
772: .popsection
773: \oldinstr
774: .pushsection .altinstructions,"a"
alt_entry 773b, 774b, 770b, 771b,\feature1
alt_entry 773b, 774b, 771b, 772b,\feature2
.popsection
.endm
#endif /* __ASSEMBLY__ */
#endif /* _ASM_S390_ALTERNATIVE_ASM_H */