mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-17 14:30:00 +00:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
107 lines
2.9 KiB
C
107 lines
2.9 KiB
C
/*
|
|
* Copyright (c) 2000-2004 Silicon Graphics, Inc. All Rights Reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of version 2 of the GNU General Public License as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it would be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
|
|
*
|
|
* Further, this software is distributed without any warranty that it is
|
|
* free of the rightful claim of any third person regarding infringement
|
|
* or the like. Any license provided herein, whether implied or
|
|
* otherwise, applies only to this software file. Patent licenses, if
|
|
* any, provided herein do not apply to combinations of this program with
|
|
* other software, or any other product whatsoever.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write the Free Software Foundation, Inc., 59
|
|
* Temple Place - Suite 330, Boston MA 02111-1307, USA.
|
|
*
|
|
* Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
|
|
* Mountain View, CA 94043, or:
|
|
*
|
|
* http://www.sgi.com
|
|
*
|
|
* For further information regarding this notice, see:
|
|
*
|
|
* http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
|
|
*/
|
|
#ifndef __XFS_SUPPORT_MRLOCK_H__
|
|
#define __XFS_SUPPORT_MRLOCK_H__
|
|
|
|
#include <linux/rwsem.h>
|
|
|
|
enum { MR_NONE, MR_ACCESS, MR_UPDATE };
|
|
|
|
typedef struct {
|
|
struct rw_semaphore mr_lock;
|
|
int mr_writer;
|
|
} mrlock_t;
|
|
|
|
#define mrinit(mrp, name) \
|
|
( (mrp)->mr_writer = 0, init_rwsem(&(mrp)->mr_lock) )
|
|
#define mrlock_init(mrp, t,n,s) mrinit(mrp, n)
|
|
#define mrfree(mrp) do { } while (0)
|
|
#define mraccess(mrp) mraccessf(mrp, 0)
|
|
#define mrupdate(mrp) mrupdatef(mrp, 0)
|
|
|
|
static inline void mraccessf(mrlock_t *mrp, int flags)
|
|
{
|
|
down_read(&mrp->mr_lock);
|
|
}
|
|
|
|
static inline void mrupdatef(mrlock_t *mrp, int flags)
|
|
{
|
|
down_write(&mrp->mr_lock);
|
|
mrp->mr_writer = 1;
|
|
}
|
|
|
|
static inline int mrtryaccess(mrlock_t *mrp)
|
|
{
|
|
return down_read_trylock(&mrp->mr_lock);
|
|
}
|
|
|
|
static inline int mrtryupdate(mrlock_t *mrp)
|
|
{
|
|
if (!down_write_trylock(&mrp->mr_lock))
|
|
return 0;
|
|
mrp->mr_writer = 1;
|
|
return 1;
|
|
}
|
|
|
|
static inline void mrunlock(mrlock_t *mrp)
|
|
{
|
|
if (mrp->mr_writer) {
|
|
mrp->mr_writer = 0;
|
|
up_write(&mrp->mr_lock);
|
|
} else {
|
|
up_read(&mrp->mr_lock);
|
|
}
|
|
}
|
|
|
|
static inline void mrdemote(mrlock_t *mrp)
|
|
{
|
|
mrp->mr_writer = 0;
|
|
downgrade_write(&mrp->mr_lock);
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
/*
|
|
* Debug-only routine, without some platform-specific asm code, we can
|
|
* now only answer requests regarding whether we hold the lock for write
|
|
* (reader state is outside our visibility, we only track writer state).
|
|
* Note: means !ismrlocked would give false positivies, so don't do that.
|
|
*/
|
|
static inline int ismrlocked(mrlock_t *mrp, int type)
|
|
{
|
|
if (mrp && type == MR_UPDATE)
|
|
return mrp->mr_writer;
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
#endif /* __XFS_SUPPORT_MRLOCK_H__ */
|