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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cmpxchg.h (2772B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2/*
      3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
      4 */
      5#ifndef __ASM_CMPXCHG_H
      6#define __ASM_CMPXCHG_H
      7
      8#include <asm/barrier.h>
      9#include <linux/build_bug.h>
     10
     11#define __xchg_asm(amswap_db, m, val)		\
     12({						\
     13		__typeof(val) __ret;		\
     14						\
     15		__asm__ __volatile__ (		\
     16		" "amswap_db" %1, %z2, %0 \n"	\
     17		: "+ZB" (*m), "=&r" (__ret)	\
     18		: "Jr" (val)			\
     19		: "memory");			\
     20						\
     21		__ret;				\
     22})
     23
     24static inline unsigned long __xchg(volatile void *ptr, unsigned long x,
     25				   int size)
     26{
     27	switch (size) {
     28	case 4:
     29		return __xchg_asm("amswap_db.w", (volatile u32 *)ptr, (u32)x);
     30
     31	case 8:
     32		return __xchg_asm("amswap_db.d", (volatile u64 *)ptr, (u64)x);
     33
     34	default:
     35		BUILD_BUG();
     36	}
     37
     38	return 0;
     39}
     40
     41#define arch_xchg(ptr, x)						\
     42({									\
     43	__typeof__(*(ptr)) __res;					\
     44									\
     45	__res = (__typeof__(*(ptr)))					\
     46		__xchg((ptr), (unsigned long)(x), sizeof(*(ptr)));	\
     47									\
     48	__res;								\
     49})
     50
     51#define __cmpxchg_asm(ld, st, m, old, new)				\
     52({									\
     53	__typeof(old) __ret;						\
     54									\
     55	__asm__ __volatile__(						\
     56	"1:	" ld "	%0, %2		# __cmpxchg_asm \n"		\
     57	"	bne	%0, %z3, 2f			\n"		\
     58	"	or	$t0, %z4, $zero			\n"		\
     59	"	" st "	$t0, %1				\n"		\
     60	"	beq	$zero, $t0, 1b			\n"		\
     61	"2:						\n"		\
     62	__WEAK_LLSC_MB							\
     63	: "=&r" (__ret), "=ZB"(*m)					\
     64	: "ZB"(*m), "Jr" (old), "Jr" (new)				\
     65	: "t0", "memory");						\
     66									\
     67	__ret;								\
     68})
     69
     70static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
     71				      unsigned long new, unsigned int size)
     72{
     73	switch (size) {
     74	case 4:
     75		return __cmpxchg_asm("ll.w", "sc.w", (volatile u32 *)ptr,
     76				     (u32)old, new);
     77
     78	case 8:
     79		return __cmpxchg_asm("ll.d", "sc.d", (volatile u64 *)ptr,
     80				     (u64)old, new);
     81
     82	default:
     83		BUILD_BUG();
     84	}
     85
     86	return 0;
     87}
     88
     89#define arch_cmpxchg_local(ptr, old, new)				\
     90	((__typeof__(*(ptr)))						\
     91		__cmpxchg((ptr),					\
     92			  (unsigned long)(__typeof__(*(ptr)))(old),	\
     93			  (unsigned long)(__typeof__(*(ptr)))(new),	\
     94			  sizeof(*(ptr))))
     95
     96#define arch_cmpxchg(ptr, old, new)					\
     97({									\
     98	__typeof__(*(ptr)) __res;					\
     99									\
    100	__res = arch_cmpxchg_local((ptr), (old), (new));		\
    101									\
    102	__res;								\
    103})
    104
    105#ifdef CONFIG_64BIT
    106#define arch_cmpxchg64_local(ptr, o, n)					\
    107  ({									\
    108	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
    109	arch_cmpxchg_local((ptr), (o), (n));				\
    110  })
    111
    112#define arch_cmpxchg64(ptr, o, n)					\
    113  ({									\
    114	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
    115	arch_cmpxchg((ptr), (o), (n));					\
    116  })
    117#else
    118#include <asm-generic/cmpxchg-local.h>
    119#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
    120#define arch_cmpxchg64(ptr, o, n) arch_cmpxchg64_local((ptr), (o), (n))
    121#endif
    122
    123#endif /* __ASM_CMPXCHG_H */