/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_S390_JUMP_LABEL_H #define _ASM_S390_JUMP_LABEL_H #ifndef __ASSEMBLY__ #include #include #define JUMP_LABEL_NOP_SIZE 6 #define JUMP_LABEL_NOP_OFFSET 2 /* * We use a brcl 0,2 instruction for jump labels at compile time so it * can be easily distinguished from a hotpatch generated instruction. */ static inline bool arch_static_branch(struct static_key *key, bool branch) { asm_volatile_goto("0: brcl 0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n" ".pushsection __jump_table,\"aw\"\n" ".balign 8\n" ".long 0b-.,%l[label]-.\n" ".quad %0-.\n" ".popsection\n" : : "X" (&((char *)key)[branch]) : : label); return false; label: return true; } static inline bool arch_static_branch_jump(struct static_key *key, bool branch) { asm_volatile_goto("0: brcl 15,%l[label]\n" ".pushsection __jump_table,\"aw\"\n" ".balign 8\n" ".long 0b-.,%l[label]-.\n" ".quad %0-.\n" ".popsection\n" : : "X" (&((char *)key)[branch]) : : label); return false; label: return true; } #endif /* __ASSEMBLY__ */ #endif