1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_S390_JUMP_LABEL_H 3 #define _ASM_S390_JUMP_LABEL_H 4 5 #define HAVE_JUMP_LABEL_BATCH 6 7 #ifndef __ASSEMBLY__ 8 9 #include <linux/types.h> 10 #include <linux/stringify.h> 11 12 #define JUMP_LABEL_NOP_SIZE 6 13 14 #ifdef CONFIG_CC_IS_CLANG 15 #define JUMP_LABEL_STATIC_KEY_CONSTRAINT "i" 16 #elif __GNUC__ < 9 17 #define JUMP_LABEL_STATIC_KEY_CONSTRAINT "X" 18 #else 19 #define JUMP_LABEL_STATIC_KEY_CONSTRAINT "jdd" 20 #endif 21 22 /* 23 * We use a brcl 0,<offset> instruction for jump labels so it 24 * can be easily distinguished from a hotpatch generated instruction. 25 */ 26 static __always_inline bool arch_static_branch(struct static_key *key, bool branch) 27 { 28 asm goto("0: brcl 0,%l[label]\n" 29 ".pushsection __jump_table,\"aw\"\n" 30 ".balign 8\n" 31 ".long 0b-.,%l[label]-.\n" 32 ".quad %0+%1-.\n" 33 ".popsection\n" 34 : : JUMP_LABEL_STATIC_KEY_CONSTRAINT (key), "i" (branch) : : label); 35 return false; 36 label: 37 return true; 38 } 39 40 static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch) 41 { 42 asm goto("0: brcl 15,%l[label]\n" 43 ".pushsection __jump_table,\"aw\"\n" 44 ".balign 8\n" 45 ".long 0b-.,%l[label]-.\n" 46 ".quad %0+%1-.\n" 47 ".popsection\n" 48 : : JUMP_LABEL_STATIC_KEY_CONSTRAINT (key), "i" (branch) : : label); 49 return false; 50 label: 51 return true; 52 } 53 54 #endif /* __ASSEMBLY__ */ 55 #endif 56