1 #ifndef _ASM_S390_JUMP_LABEL_H 2 #define _ASM_S390_JUMP_LABEL_H 3 4 #ifndef __ASSEMBLY__ 5 6 #include <linux/types.h> 7 8 #define JUMP_LABEL_NOP_SIZE 6 9 #define JUMP_LABEL_NOP_OFFSET 2 10 11 /* 12 * We use a brcl 0,2 instruction for jump labels at compile time so it 13 * can be easily distinguished from a hotpatch generated instruction. 14 */ 15 static __always_inline bool arch_static_branch(struct static_key *key) 16 { 17 asm_volatile_goto("0: brcl 0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n" 18 ".pushsection __jump_table, \"aw\"\n" 19 ".balign 8\n" 20 ".quad 0b, %l[label], %0\n" 21 ".popsection\n" 22 : : "X" (key) : : label); 23 return false; 24 label: 25 return true; 26 } 27 28 typedef unsigned long jump_label_t; 29 30 struct jump_entry { 31 jump_label_t code; 32 jump_label_t target; 33 jump_label_t key; 34 }; 35 36 #endif /* __ASSEMBLY__ */ 37 #endif 38