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 #include <linux/stringify.h> 8 9 #define JUMP_LABEL_NOP_SIZE 6 10 #define JUMP_LABEL_NOP_OFFSET 2 11 12 /* 13 * We use a brcl 0,2 instruction for jump labels at compile time so it 14 * can be easily distinguished from a hotpatch generated instruction. 15 */ 16 static __always_inline bool arch_static_branch(struct static_key *key, bool branch) 17 { 18 asm_volatile_goto("0: brcl 0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n" 19 ".pushsection __jump_table, \"aw\"\n" 20 ".balign 8\n" 21 ".quad 0b, %l[label], %0\n" 22 ".popsection\n" 23 : : "X" (&((char *)key)[branch]) : : label); 24 25 return false; 26 label: 27 return true; 28 } 29 30 static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch) 31 { 32 asm_volatile_goto("0: brcl 15, %l[label]\n" 33 ".pushsection __jump_table, \"aw\"\n" 34 ".balign 8\n" 35 ".quad 0b, %l[label], %0\n" 36 ".popsection\n" 37 : : "X" (&((char *)key)[branch]) : : label); 38 39 return false; 40 label: 41 return true; 42 } 43 44 typedef unsigned long jump_label_t; 45 46 struct jump_entry { 47 jump_label_t code; 48 jump_label_t target; 49 jump_label_t key; 50 }; 51 52 #endif /* __ASSEMBLY__ */ 53 #endif 54