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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mrlock.h (1630B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
      4 * All Rights Reserved.
      5 */
      6#ifndef __XFS_SUPPORT_MRLOCK_H__
      7#define __XFS_SUPPORT_MRLOCK_H__
      8
      9#include <linux/rwsem.h>
     10
     11typedef struct {
     12	struct rw_semaphore	mr_lock;
     13#if defined(DEBUG) || defined(XFS_WARN)
     14	int			mr_writer;
     15#endif
     16} mrlock_t;
     17
     18#if defined(DEBUG) || defined(XFS_WARN)
     19#define mrinit(mrp, name)	\
     20	do { (mrp)->mr_writer = 0; init_rwsem(&(mrp)->mr_lock); } while (0)
     21#else
     22#define mrinit(mrp, name)	\
     23	do { init_rwsem(&(mrp)->mr_lock); } while (0)
     24#endif
     25
     26#define mrlock_init(mrp, t,n,s)	mrinit(mrp, n)
     27#define mrfree(mrp)		do { } while (0)
     28
     29static inline void mraccess_nested(mrlock_t *mrp, int subclass)
     30{
     31	down_read_nested(&mrp->mr_lock, subclass);
     32}
     33
     34static inline void mrupdate_nested(mrlock_t *mrp, int subclass)
     35{
     36	down_write_nested(&mrp->mr_lock, subclass);
     37#if defined(DEBUG) || defined(XFS_WARN)
     38	mrp->mr_writer = 1;
     39#endif
     40}
     41
     42static inline int mrtryaccess(mrlock_t *mrp)
     43{
     44	return down_read_trylock(&mrp->mr_lock);
     45}
     46
     47static inline int mrtryupdate(mrlock_t *mrp)
     48{
     49	if (!down_write_trylock(&mrp->mr_lock))
     50		return 0;
     51#if defined(DEBUG) || defined(XFS_WARN)
     52	mrp->mr_writer = 1;
     53#endif
     54	return 1;
     55}
     56
     57static inline void mrunlock_excl(mrlock_t *mrp)
     58{
     59#if defined(DEBUG) || defined(XFS_WARN)
     60	mrp->mr_writer = 0;
     61#endif
     62	up_write(&mrp->mr_lock);
     63}
     64
     65static inline void mrunlock_shared(mrlock_t *mrp)
     66{
     67	up_read(&mrp->mr_lock);
     68}
     69
     70static inline void mrdemote(mrlock_t *mrp)
     71{
     72#if defined(DEBUG) || defined(XFS_WARN)
     73	mrp->mr_writer = 0;
     74#endif
     75	downgrade_write(&mrp->mr_lock);
     76}
     77
     78#endif /* __XFS_SUPPORT_MRLOCK_H__ */