#ifndef _ASM_S390_JUMP_LABEL_H #define _ASM_S390_JUMP_LABEL_H #ifndef __ASSEMBLY__ #include <linux/types.h> #include <linux/stringify.h> #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 __always_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" ".quad 0b, %l[label], %0\n" ".popsection\n" : : "X" (&((char *)key)[branch]) : : label); return false; label: return true; } static __always_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" ".quad 0b, %l[label], %0\n" ".popsection\n" : : "X" (&((char *)key)[branch]) : : label); return false; label: return true; } typedef unsigned long jump_label_t; struct jump_entry { jump_label_t code; jump_label_t target; jump_label_t key; }; #endif /* __ASSEMBLY__ */ #endif |