55 lines
1.4 KiB
C
55 lines
1.4 KiB
C
/* 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
|
|
|
|
#ifdef CONFIG_CC_IS_CLANG
|
|
#define JUMP_LABEL_STATIC_KEY_CONSTRAINT "i"
|
|
#elif __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"
|
|
".long 0b-.,%l[label]-.\n"
|
|
".quad %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"
|
|
".long 0b-.,%l[label]-.\n"
|
|
".quad %0+%1-.\n"
|
|
".popsection\n"
|
|
: : JUMP_LABEL_STATIC_KEY_CONSTRAINT (key), "i" (branch) : : label);
|
|
return false;
|
|
label:
|
|
return true;
|
|
}
|
|
|
|
#endif /* __ASSEMBLY__ */
|
|
#endif
|