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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_S390_JUMP_LABEL_H
#define _ASM_S390_JUMP_LABEL_H
#ifndef __ASSEMBLY__
#include <linux/types.h>
#include <linux/stringify.h>
#define JUMP_LABEL_NOP_SIZE 6
#define JUMP_LABEL_NOP_OFFSET 2
#if __GNUC__ < 9
#define JUMP_LABEL_STATIC_KEY_CONSTRAINT "X"
#else
#define JUMP_LABEL_STATIC_KEY_CONSTRAINT "jdd"
#endif
/*
* 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, bool branch)
{
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+%1\n"
".popsection\n"
: : JUMP_LABEL_STATIC_KEY_CONSTRAINT (key), "i" (branch) : : label);
return false;
label:
return true;
}
static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
{
asm_volatile_goto("0: brcl 15, %l[label]\n"
".pushsection __jump_table, \"aw\"\n"
".balign 8\n"
".quad 0b, %l[label], %0+%1\n"
".popsection\n"
: : JUMP_LABEL_STATIC_KEY_CONSTRAINT (key), "i" (branch) : : 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
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