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_32.h (2483B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2/* 32-bit atomic xchg() and cmpxchg() definitions.
      3 *
      4 * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
      5 * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com.au)
      6 * Copyright (C) 2007 Kyle McMartin (kyle@parisc-linux.org)
      7 *
      8 * Additions by Keith M Wesolowski (wesolows@foobazco.org) based
      9 * on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>.
     10 */
     11
     12#ifndef __ARCH_SPARC_CMPXCHG__
     13#define __ARCH_SPARC_CMPXCHG__
     14
     15unsigned long __xchg_u32(volatile u32 *m, u32 new);
     16void __xchg_called_with_bad_pointer(void);
     17
     18static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr, int size)
     19{
     20	switch (size) {
     21	case 4:
     22		return __xchg_u32(ptr, x);
     23	}
     24	__xchg_called_with_bad_pointer();
     25	return x;
     26}
     27
     28#define arch_xchg(ptr,x) ({(__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)));})
     29
     30/* Emulate cmpxchg() the same way we emulate atomics,
     31 * by hashing the object address and indexing into an array
     32 * of spinlocks to get a bit of performance...
     33 *
     34 * See arch/sparc/lib/atomic32.c for implementation.
     35 *
     36 * Cribbed from <asm-parisc/atomic.h>
     37 */
     38
     39/* bug catcher for when unsupported size is used - won't link */
     40void __cmpxchg_called_with_bad_pointer(void);
     41/* we only need to support cmpxchg of a u32 on sparc */
     42unsigned long __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_);
     43
     44/* don't worry...optimizer will get rid of most of this */
     45static inline unsigned long
     46__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
     47{
     48	switch (size) {
     49	case 4:
     50		return __cmpxchg_u32((u32 *)ptr, (u32)old, (u32)new_);
     51	default:
     52		__cmpxchg_called_with_bad_pointer();
     53		break;
     54	}
     55	return old;
     56}
     57
     58#define arch_cmpxchg(ptr, o, n)						\
     59({									\
     60	__typeof__(*(ptr)) _o_ = (o);					\
     61	__typeof__(*(ptr)) _n_ = (n);					\
     62	(__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,	\
     63			(unsigned long)_n_, sizeof(*(ptr)));		\
     64})
     65
     66u64 __cmpxchg_u64(u64 *ptr, u64 old, u64 new);
     67#define arch_cmpxchg64(ptr, old, new)	__cmpxchg_u64(ptr, old, new)
     68
     69#include <asm-generic/cmpxchg-local.h>
     70
     71/*
     72 * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
     73 * them available.
     74 */
     75#define arch_cmpxchg_local(ptr, o, n)				  	       \
     76	((__typeof__(*(ptr)))__generic_cmpxchg_local((ptr), (unsigned long)(o),\
     77			(unsigned long)(n), sizeof(*(ptr))))
     78#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
     79
     80#endif /* __ARCH_SPARC_CMPXCHG__ */