mirror_zfs/include/os/linux/spl/sys/rwlock.h
Matthew Macy 006e9a4088 OpenZFS restructuring - move platform specific headers
Move platform specific Linux headers under include/os/linux/.
Update the build system accordingly to detect the platform.
This lays some of the initial groundwork to supporting building
for other platforms.

As part of this change it was necessary to create both a user
and kernel space sys/simd.h header which can be included in
either context.  No functional change, the source has been
refactored and the relevant #include's updated.

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Signed-off-by: Matthew Macy <mmacy@FreeBSD.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #9198
2019-09-05 09:34:54 -07:00

202 lines
4.7 KiB
C

/*
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
* UCRL-CODE-235197
*
* This file is part of the SPL, Solaris Porting Layer.
* For details, see <http://zfsonlinux.org/>.
*
* The SPL is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* The SPL is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with the SPL. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _SPL_RWLOCK_H
#define _SPL_RWLOCK_H
#include <sys/types.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
typedef enum {
RW_DRIVER = 2,
RW_DEFAULT = 4,
RW_NOLOCKDEP = 5
} krw_type_t;
typedef enum {
RW_NONE = 0,
RW_WRITER = 1,
RW_READER = 2
} krw_t;
typedef struct {
struct rw_semaphore rw_rwlock;
kthread_t *rw_owner;
#ifdef CONFIG_LOCKDEP
krw_type_t rw_type;
#endif /* CONFIG_LOCKDEP */
} krwlock_t;
#define SEM(rwp) (&(rwp)->rw_rwlock)
static inline void
spl_rw_set_owner(krwlock_t *rwp)
{
rwp->rw_owner = current;
}
static inline void
spl_rw_clear_owner(krwlock_t *rwp)
{
rwp->rw_owner = NULL;
}
static inline kthread_t *
rw_owner(krwlock_t *rwp)
{
return (rwp->rw_owner);
}
#ifdef CONFIG_LOCKDEP
static inline void
spl_rw_set_type(krwlock_t *rwp, krw_type_t type)
{
rwp->rw_type = type;
}
static inline void
spl_rw_lockdep_off_maybe(krwlock_t *rwp) \
{ \
if (rwp && rwp->rw_type == RW_NOLOCKDEP) \
lockdep_off(); \
}
static inline void
spl_rw_lockdep_on_maybe(krwlock_t *rwp) \
{ \
if (rwp && rwp->rw_type == RW_NOLOCKDEP) \
lockdep_on(); \
}
#else /* CONFIG_LOCKDEP */
#define spl_rw_set_type(rwp, type)
#define spl_rw_lockdep_off_maybe(rwp)
#define spl_rw_lockdep_on_maybe(rwp)
#endif /* CONFIG_LOCKDEP */
static inline int
RW_LOCK_HELD(krwlock_t *rwp)
{
return (rwsem_is_locked(SEM(rwp)));
}
static inline int
RW_WRITE_HELD(krwlock_t *rwp)
{
return (rw_owner(rwp) == current);
}
static inline int
RW_READ_HELD(krwlock_t *rwp)
{
return (RW_LOCK_HELD(rwp) && rw_owner(rwp) == NULL);
}
/*
* The following functions must be a #define and not static inline.
* This ensures that the native linux semaphore functions (down/up)
* will be correctly located in the users code which is important
* for the built in kernel lock analysis tools
*/
/* BEGIN CSTYLED */
#define rw_init(rwp, name, type, arg) \
({ \
static struct lock_class_key __key; \
ASSERT(type == RW_DEFAULT || type == RW_NOLOCKDEP); \
\
__init_rwsem(SEM(rwp), #rwp, &__key); \
spl_rw_clear_owner(rwp); \
spl_rw_set_type(rwp, type); \
})
/*
* The Linux rwsem implementation does not require a matching destroy.
*/
#define rw_destroy(rwp) ((void) 0)
/*
* Upgrading a rwsem from a reader to a writer is not supported by the
* Linux kernel. The lock must be dropped and reacquired as a writer.
*/
#define rw_tryupgrade(rwp) RW_WRITE_HELD(rwp)
#define rw_tryenter(rwp, rw) \
({ \
int _rc_ = 0; \
\
spl_rw_lockdep_off_maybe(rwp); \
switch (rw) { \
case RW_READER: \
_rc_ = down_read_trylock(SEM(rwp)); \
break; \
case RW_WRITER: \
if ((_rc_ = down_write_trylock(SEM(rwp)))) \
spl_rw_set_owner(rwp); \
break; \
default: \
VERIFY(0); \
} \
spl_rw_lockdep_on_maybe(rwp); \
_rc_; \
})
#define rw_enter(rwp, rw) \
({ \
spl_rw_lockdep_off_maybe(rwp); \
switch (rw) { \
case RW_READER: \
down_read(SEM(rwp)); \
break; \
case RW_WRITER: \
down_write(SEM(rwp)); \
spl_rw_set_owner(rwp); \
break; \
default: \
VERIFY(0); \
} \
spl_rw_lockdep_on_maybe(rwp); \
})
#define rw_exit(rwp) \
({ \
spl_rw_lockdep_off_maybe(rwp); \
if (RW_WRITE_HELD(rwp)) { \
spl_rw_clear_owner(rwp); \
up_write(SEM(rwp)); \
} else { \
ASSERT(RW_READ_HELD(rwp)); \
up_read(SEM(rwp)); \
} \
spl_rw_lockdep_on_maybe(rwp); \
})
#define rw_downgrade(rwp) \
({ \
spl_rw_lockdep_off_maybe(rwp); \
spl_rw_clear_owner(rwp); \
downgrade_write(SEM(rwp)); \
spl_rw_lockdep_on_maybe(rwp); \
})
/* END CSTYLED */
#endif /* _SPL_RWLOCK_H */