[deliverable/linux.git] / arch / s390 / include / asm / jump_label.h

#ifndef _ASM_S390_JUMP_LABEL_H
#define _ASM_S390_JUMP_LABEL_H

#ifndef __ASSEMBLY__

#include <linux/types.h>

#define JUMP_LABEL_NOP_SIZE 6
#define JUMP_LABEL_NOP_OFFSET 2

/*
 * We use a brcl 0,2 instruction for jump labels at compile time so it
 * can be easily distinguished from a hotpatch generated instruction.
 */
static __always_inline bool arch_static_branch(struct static_key *key)
{
	asm_volatile_goto("0:	brcl 0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n"
		".pushsection __jump_table, \"aw\"\n"
		".balign 8\n"
		".quad 0b, %l[label], %0\n"
		".popsection\n"
		: : "X" (key) : : label);
	return false;
label:
	return true;
}

typedef unsigned long jump_label_t;

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

#endif  /* __ASSEMBLY__ */
#endif
Commit	Line	Data
5373db88 JG	1	#ifndef _ASM_S390_JUMP_LABEL_H
	2	#define _ASM_S390_JUMP_LABEL_H
	3
55dd0df7 AB	4	#ifndef __ASSEMBLY__
55dd0df7 AB	5
5373db88 JG	6	#include <linux/types.h>
	7
	8	#define JUMP_LABEL_NOP_SIZE 6
d5caa4db	9	#define JUMP_LABEL_NOP_OFFSET 2
5373db88	10
d5caa4db HC	11	/*
	12	* We use a brcl 0,2 instruction for jump labels at compile time so it
	13	* can be easily distinguished from a hotpatch generated instruction.
	14	*/
c5905afb	15	static __always_inline bool arch_static_branch(struct static_key *key)
5373db88	16	{
d5caa4db	17	asm_volatile_goto("0: brcl 0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n"
5373db88	18	".pushsection __jump_table, \"aw\"\n"
5a79859a HC	19	".balign 8\n"
5a79859a HC	20	".quad 0b, %l[label], %0\n"
5373db88 JG	21	".popsection\n"
	22	: : "X" (key) : : label);
	23	return false;
	24	label:
	25	return true;
	26	}
	27
	28	typedef unsigned long jump_label_t;
	29
	30	struct jump_entry {
	31	jump_label_t code;
	32	jump_label_t target;
	33	jump_label_t key;
	34	};
	35
55dd0df7	36	#endif /* __ASSEMBLY__ */
5373db88	37	#endif