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, bool branch) 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" (&((char *)key)[branch]) : : label); 23 24 return false; 25 label: 26 return true; 27 } 28 29 static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch) 30 { 31 asm_volatile_goto("0: brcl 15, %l[label]\n" 32 ".pushsection __jump_table, \"aw\"\n" 33 ".balign 8\n" 34 ".quad 0b, %l[label], %0\n" 35 ".popsection\n" 36 : : "X" (&((char *)key)[branch]) : : label); 37 38 return false; 39 label: 40 return true; 41 } 42 43 typedef unsigned long jump_label_t; 44 45 struct jump_entry { 46 jump_label_t code; 47 jump_label_t target; 48 jump_label_t key; 49 }; 50 51 #endif /* __ASSEMBLY__ */ 52 #endif 53