cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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jump_label.h (1442B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2#ifndef _ASM_S390_JUMP_LABEL_H
      3#define _ASM_S390_JUMP_LABEL_H
      4
      5#define HAVE_JUMP_LABEL_BATCH
      6
      7#ifndef __ASSEMBLY__
      8
      9#include <linux/types.h>
     10#include <linux/stringify.h>
     11
     12#define JUMP_LABEL_NOP_SIZE 6
     13#define JUMP_LABEL_NOP_OFFSET 2
     14
     15#ifdef CONFIG_CC_IS_CLANG
     16#define JUMP_LABEL_STATIC_KEY_CONSTRAINT "i"
     17#elif __GNUC__ < 9
     18#define JUMP_LABEL_STATIC_KEY_CONSTRAINT "X"
     19#else
     20#define JUMP_LABEL_STATIC_KEY_CONSTRAINT "jdd"
     21#endif
     22
     23/*
     24 * We use a brcl 0,2 instruction for jump labels at compile time so it
     25 * can be easily distinguished from a hotpatch generated instruction.
     26 */
     27static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
     28{
     29	asm_volatile_goto("0:	brcl	0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n"
     30			  ".pushsection __jump_table,\"aw\"\n"
     31			  ".balign	8\n"
     32			  ".long	0b-.,%l[label]-.\n"
     33			  ".quad	%0+%1-.\n"
     34			  ".popsection\n"
     35			  : : JUMP_LABEL_STATIC_KEY_CONSTRAINT (key), "i" (branch) : : label);
     36	return false;
     37label:
     38	return true;
     39}
     40
     41static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
     42{
     43	asm_volatile_goto("0:	brcl 15,%l[label]\n"
     44			  ".pushsection __jump_table,\"aw\"\n"
     45			  ".balign	8\n"
     46			  ".long	0b-.,%l[label]-.\n"
     47			  ".quad	%0+%1-.\n"
     48			  ".popsection\n"
     49			  : : JUMP_LABEL_STATIC_KEY_CONSTRAINT (key), "i" (branch) : : label);
     50	return false;
     51label:
     52	return true;
     53}
     54
     55#endif  /* __ASSEMBLY__ */
     56#endif