diff options
Diffstat (limited to 'arch/x86/include/asm/jump_label.h')
-rw-r--r-- | arch/x86/include/asm/jump_label.h | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h new file mode 100644 index 000000000..071572e23 --- /dev/null +++ b/arch/x86/include/asm/jump_label.h @@ -0,0 +1,69 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_JUMP_LABEL_H +#define _ASM_X86_JUMP_LABEL_H + +#define HAVE_JUMP_LABEL_BATCH + +#include <asm/asm.h> +#include <asm/nops.h> + +#ifndef __ASSEMBLY__ + +#include <linux/stringify.h> +#include <linux/types.h> + +#define JUMP_TABLE_ENTRY \ + ".pushsection __jump_table, \"aw\" \n\t" \ + _ASM_ALIGN "\n\t" \ + ".long 1b - . \n\t" \ + ".long %l[l_yes] - . \n\t" \ + _ASM_PTR "%c0 + %c1 - .\n\t" \ + ".popsection \n\t" + +#ifdef CONFIG_HAVE_JUMP_LABEL_HACK + +static __always_inline bool arch_static_branch(struct static_key *key, bool branch) +{ + asm_volatile_goto("1:" + "jmp %l[l_yes] # objtool NOPs this \n\t" + JUMP_TABLE_ENTRY + : : "i" (key), "i" (2 | branch) : : l_yes); + + return false; +l_yes: + return true; +} + +#else /* !CONFIG_HAVE_JUMP_LABEL_HACK */ + +static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch) +{ + asm_volatile_goto("1:" + ".byte " __stringify(BYTES_NOP5) "\n\t" + JUMP_TABLE_ENTRY + : : "i" (key), "i" (branch) : : l_yes); + + return false; +l_yes: + return true; +} + +#endif /* CONFIG_HAVE_JUMP_LABEL_HACK */ + +static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch) +{ + asm_volatile_goto("1:" + "jmp %l[l_yes]\n\t" + JUMP_TABLE_ENTRY + : : "i" (key), "i" (branch) : : l_yes); + + return false; +l_yes: + return true; +} + +extern int arch_jump_entry_size(struct jump_entry *entry); + +#endif /* __ASSEMBLY__ */ + +#endif |