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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bitops.c (2081B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * bitops.c: atomic operations which got too long to be inlined all over
      4 *      the place.
      5 * 
      6 * Copyright 1999 Philipp Rumpf (prumpf@tux.org)
      7 * Copyright 2000 Grant Grundler (grundler@cup.hp.com)
      8 */
      9
     10#include <linux/kernel.h>
     11#include <linux/spinlock.h>
     12#include <linux/atomic.h>
     13
     14#ifdef CONFIG_SMP
     15arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
     16	[0 ... (ATOMIC_HASH_SIZE-1)]  = __ARCH_SPIN_LOCK_UNLOCKED
     17};
     18#endif
     19
     20#ifdef CONFIG_64BIT
     21unsigned long notrace __xchg64(unsigned long x, volatile unsigned long *ptr)
     22{
     23	unsigned long temp, flags;
     24
     25	_atomic_spin_lock_irqsave(ptr, flags);
     26	temp = *ptr;
     27	*ptr = x;
     28	_atomic_spin_unlock_irqrestore(ptr, flags);
     29	return temp;
     30}
     31#endif
     32
     33unsigned long notrace __xchg32(int x, volatile int *ptr)
     34{
     35	unsigned long flags;
     36	long temp;
     37
     38	_atomic_spin_lock_irqsave(ptr, flags);
     39	temp = (long) *ptr;	/* XXX - sign extension wanted? */
     40	*ptr = x;
     41	_atomic_spin_unlock_irqrestore(ptr, flags);
     42	return (unsigned long)temp;
     43}
     44
     45
     46unsigned long notrace __xchg8(char x, volatile char *ptr)
     47{
     48	unsigned long flags;
     49	long temp;
     50
     51	_atomic_spin_lock_irqsave(ptr, flags);
     52	temp = (long) *ptr;	/* XXX - sign extension wanted? */
     53	*ptr = x;
     54	_atomic_spin_unlock_irqrestore(ptr, flags);
     55	return (unsigned long)temp;
     56}
     57
     58
     59u64 notrace __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new)
     60{
     61	unsigned long flags;
     62	u64 prev;
     63
     64	_atomic_spin_lock_irqsave(ptr, flags);
     65	if ((prev = *ptr) == old)
     66		*ptr = new;
     67	_atomic_spin_unlock_irqrestore(ptr, flags);
     68	return prev;
     69}
     70
     71unsigned long notrace __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new)
     72{
     73	unsigned long flags;
     74	unsigned int prev;
     75
     76	_atomic_spin_lock_irqsave(ptr, flags);
     77	if ((prev = *ptr) == old)
     78		*ptr = new;
     79	_atomic_spin_unlock_irqrestore(ptr, flags);
     80	return (unsigned long)prev;
     81}
     82
     83u8 notrace __cmpxchg_u8(volatile u8 *ptr, u8 old, u8 new)
     84{
     85	unsigned long flags;
     86	u8 prev;
     87
     88	_atomic_spin_lock_irqsave(ptr, flags);
     89	if ((prev = *ptr) == old)
     90		*ptr = new;
     91	_atomic_spin_unlock_irqrestore(ptr, flags);
     92	return prev;
     93}