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linux-next/include/linux/local_lock_internal.h
Thomas Gleixner 026659b977 locking/local_lock: Add PREEMPT_RT support
On PREEMPT_RT enabled kernels local_lock maps to a per CPU 'sleeping'
spinlock which protects the critical section while staying preemptible. CPU
locality is established by disabling migration.

Provide the necessary types and macros to substitute the non-RT variant.

Co-developed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211306.023630962@linutronix.de
2021-08-17 19:08:49 +02:00

142 lines
3.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_LOCAL_LOCK_H
# error "Do not include directly, include linux/local_lock.h"
#endif
#include <linux/percpu-defs.h>
#include <linux/lockdep.h>
#ifndef CONFIG_PREEMPT_RT
typedef struct {
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
struct task_struct *owner;
#endif
} local_lock_t;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define LOCAL_LOCK_DEBUG_INIT(lockname) \
.dep_map = { \
.name = #lockname, \
.wait_type_inner = LD_WAIT_CONFIG, \
.lock_type = LD_LOCK_PERCPU, \
}, \
.owner = NULL,
static inline void local_lock_acquire(local_lock_t *l)
{
lock_map_acquire(&l->dep_map);
DEBUG_LOCKS_WARN_ON(l->owner);
l->owner = current;
}
static inline void local_lock_release(local_lock_t *l)
{
DEBUG_LOCKS_WARN_ON(l->owner != current);
l->owner = NULL;
lock_map_release(&l->dep_map);
}
static inline void local_lock_debug_init(local_lock_t *l)
{
l->owner = NULL;
}
#else /* CONFIG_DEBUG_LOCK_ALLOC */
# define LOCAL_LOCK_DEBUG_INIT(lockname)
static inline void local_lock_acquire(local_lock_t *l) { }
static inline void local_lock_release(local_lock_t *l) { }
static inline void local_lock_debug_init(local_lock_t *l) { }
#endif /* !CONFIG_DEBUG_LOCK_ALLOC */
#define INIT_LOCAL_LOCK(lockname) { LOCAL_LOCK_DEBUG_INIT(lockname) }
#define __local_lock_init(lock) \
do { \
static struct lock_class_key __key; \
\
debug_check_no_locks_freed((void *)lock, sizeof(*lock));\
lockdep_init_map_type(&(lock)->dep_map, #lock, &__key, \
0, LD_WAIT_CONFIG, LD_WAIT_INV, \
LD_LOCK_PERCPU); \
local_lock_debug_init(lock); \
} while (0)
#define __local_lock(lock) \
do { \
preempt_disable(); \
local_lock_acquire(this_cpu_ptr(lock)); \
} while (0)
#define __local_lock_irq(lock) \
do { \
local_irq_disable(); \
local_lock_acquire(this_cpu_ptr(lock)); \
} while (0)
#define __local_lock_irqsave(lock, flags) \
do { \
local_irq_save(flags); \
local_lock_acquire(this_cpu_ptr(lock)); \
} while (0)
#define __local_unlock(lock) \
do { \
local_lock_release(this_cpu_ptr(lock)); \
preempt_enable(); \
} while (0)
#define __local_unlock_irq(lock) \
do { \
local_lock_release(this_cpu_ptr(lock)); \
local_irq_enable(); \
} while (0)
#define __local_unlock_irqrestore(lock, flags) \
do { \
local_lock_release(this_cpu_ptr(lock)); \
local_irq_restore(flags); \
} while (0)
#else /* !CONFIG_PREEMPT_RT */
/*
* On PREEMPT_RT local_lock maps to a per CPU spinlock, which protects the
* critical section while staying preemptible.
*/
typedef spinlock_t local_lock_t;
#define INIT_LOCAL_LOCK(lockname) __LOCAL_SPIN_LOCK_UNLOCKED((lockname))
#define __local_lock_init(l) \
do { \
local_spin_lock_init((l)); \
} while (0)
#define __local_lock(__lock) \
do { \
migrate_disable(); \
spin_lock(this_cpu_ptr((__lock))); \
} while (0)
#define __local_lock_irq(lock) __local_lock(lock)
#define __local_lock_irqsave(lock, flags) \
do { \
typecheck(unsigned long, flags); \
flags = 0; \
__local_lock(lock); \
} while (0)
#define __local_unlock(__lock) \
do { \
spin_unlock(this_cpu_ptr((__lock))); \
migrate_enable(); \
} while (0)
#define __local_unlock_irq(lock) __local_unlock(lock)
#define __local_unlock_irqrestore(lock, flags) __local_unlock(lock)
#endif /* CONFIG_PREEMPT_RT */