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v0.8.1
https://github.com/torvalds/linux
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Tip revision: 9e82bf014195d6f0054982c463575cdce24292be authored by Linus Torvalds on 15 September 2014, 00:50:12 UTC
Linux 3.17-rc5
Tip revision: 9e82bf0
jump_label.h
#ifndef _ASM_X86_JUMP_LABEL_H
#define _ASM_X86_JUMP_LABEL_H

#ifdef __KERNEL__

#include <linux/stringify.h>
#include <linux/types.h>
#include <asm/nops.h>
#include <asm/asm.h>

#define JUMP_LABEL_NOP_SIZE 5

#ifdef CONFIG_X86_64
# define STATIC_KEY_INIT_NOP P6_NOP5_ATOMIC
#else
# define STATIC_KEY_INIT_NOP GENERIC_NOP5_ATOMIC
#endif

static __always_inline bool arch_static_branch(struct static_key *key)
{
	asm_volatile_goto("1:"
		".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t"
		".pushsection __jump_table,  \"aw\" \n\t"
		_ASM_ALIGN "\n\t"
		_ASM_PTR "1b, %l[l_yes], %c0 \n\t"
		".popsection \n\t"
		: :  "i" (key) : : l_yes);
	return false;
l_yes:
	return true;
}

#endif /* __KERNEL__ */

#ifdef CONFIG_X86_64
typedef u64 jump_label_t;
#else
typedef u32 jump_label_t;
#endif

struct jump_entry {
	jump_label_t code;
	jump_label_t target;
	jump_label_t key;
};

#endif
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