#ifndef _ASM_X86_ALTERNATIVE_ASM_H #define _ASM_X86_ALTERNATIVE_ASM_H #ifdef __ASSEMBLY__ #include <asm/asm.h> #ifdef CONFIG_SMP .macro LOCK_PREFIX 672: lock .pushsection .smp_locks,"a" .balign 4 .long 672b - . .popsection .endm #else .macro LOCK_PREFIX .endm #endif .macro altinstruction_entry orig alt feature orig_len alt_len pad_len .long \orig - . .long \alt - . .word \feature .byte \orig_len .byte \alt_len .byte \pad_len .endm .macro ALTERNATIVE oldinstr, newinstr, feature 140: \oldinstr 141: .skip -(((144f-143f)-(141b-140b)) > 0) * ((144f-143f)-(141b-140b)),0x90 142: .pushsection .altinstructions,"a" altinstruction_entry 140b,143f,\feature,142b-140b,144f-143f,142b-141b .popsection .pushsection .altinstr_replacement,"ax" 143: \newinstr 144: .popsection .endm #define old_len 141b-140b #define new_len1 144f-143f #define new_len2 145f-144f /* * max without conditionals. Idea adapted from: * http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax */ #define alt_max_short(a, b) ((a) ^ (((a) ^ (b)) & -(-((a) < (b))))) .macro ALTERNATIVE_2 oldinstr, newinstr1, feature1, newinstr2, feature2 140: \oldinstr 141: .skip -((alt_max_short(new_len1, new_len2) - (old_len)) > 0) * \ (alt_max_short(new_len1, new_len2) - (old_len)),0x90 142: .pushsection .altinstructions,"a" altinstruction_entry 140b,143f,\feature1,142b-140b,144f-143f,142b-141b altinstruction_entry 140b,144f,\feature2,142b-140b,145f-144f,142b-141b .popsection .pushsection .altinstr_replacement,"ax" 143: \newinstr1 144: \newinstr2 145: .popsection .endm #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_ALTERNATIVE_ASM_H */