1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_X86_JUMP_LABEL_H 3 #define _ASM_X86_JUMP_LABEL_H 4 5 #define HAVE_JUMP_LABEL_BATCH 6 7 #include <asm/asm.h> 8 #include <asm/nops.h> 9 10 #ifndef __ASSEMBLER__ 11 12 #include <linux/stringify.h> 13 #include <linux/types.h> 14 15 #define JUMP_TABLE_ENTRY(key, label) \ 16 ".pushsection __jump_table, \"aw\" \n\t" \ 17 _ASM_ALIGN "\n\t" \ 18 ANNOTATE_DATA_SPECIAL \ 19 ".long 1b - . \n\t" \ 20 ".long " label " - . \n\t" \ 21 _ASM_PTR " " key " - . \n\t" \ 22 ".popsection \n\t" 23 24 /* This macro is also expanded on the Rust side. */ 25 #ifdef CONFIG_HAVE_JUMP_LABEL_HACK 26 #define ARCH_STATIC_BRANCH_ASM(key, label) \ 27 "1: jmp " label " # objtool NOPs this \n\t" \ 28 JUMP_TABLE_ENTRY(key " + 2", label) 29 #else /* !CONFIG_HAVE_JUMP_LABEL_HACK */ 30 #define ARCH_STATIC_BRANCH_ASM(key, label) \ 31 "1: .byte " __stringify(BYTES_NOP5) "\n\t" \ 32 JUMP_TABLE_ENTRY(key, label) 33 #endif /* CONFIG_HAVE_JUMP_LABEL_HACK */ 34 35 static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch) 36 { 37 asm goto(ARCH_STATIC_BRANCH_ASM("%c0 + %c1", "%l[l_yes]") 38 : : "i" (key), "i" (branch) : : l_yes); 39 40 return false; 41 l_yes: 42 return true; 43 } 44 45 static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch) 46 { 47 asm goto("1:" 48 "jmp %l[l_yes]\n\t" 49 JUMP_TABLE_ENTRY("%c0 + %c1", "%l[l_yes]") 50 : : "i" (key), "i" (branch) : : l_yes); 51 52 return false; 53 l_yes: 54 return true; 55 } 56 57 extern int arch_jump_entry_size(struct jump_entry *entry); 58 59 #endif /* __ASSEMBLER__ */ 60 61 #endif 62