rte_spinlock.h

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/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2014 Intel Corporation
 */

#ifndef _RTE_SPINLOCK_H_
#define _RTE_SPINLOCK_H_

#include <rte_lcore.h>
#ifdef RTE_FORCE_INTRINSICS
#include <rte_common.h>
#endif
#include <rte_lock_annotations.h>
#include <rte_pause.h>

typedef struct __rte_lockable {
    volatile int locked; 
} rte_spinlock_t;

#define RTE_SPINLOCK_INITIALIZER { 0 }

static inline void
rte_spinlock_init(rte_spinlock_t *sl)
{
    sl->locked = 0;
}

static inline void
rte_spinlock_lock(rte_spinlock_t *sl)
    __rte_exclusive_lock_function(sl);

#ifdef RTE_FORCE_INTRINSICS
static inline void
rte_spinlock_lock(rte_spinlock_t *sl)
    __rte_no_thread_safety_analysis
{
    int exp = 0;

    while (!__atomic_compare_exchange_n(&sl->locked, &exp, 1, 0,
                __ATOMIC_ACQUIRE, __ATOMIC_RELAXED)) {
        rte_wait_until_equal_32((volatile uint32_t *)&sl->locked,
                   0, __ATOMIC_RELAXED);
        exp = 0;
    }
}
#endif

static inline void
rte_spinlock_unlock(rte_spinlock_t *sl)
    __rte_unlock_function(sl);

#ifdef RTE_FORCE_INTRINSICS
static inline void
rte_spinlock_unlock(rte_spinlock_t *sl)
    __rte_no_thread_safety_analysis
{
    __atomic_store_n(&sl->locked, 0, __ATOMIC_RELEASE);
}
#endif

__rte_warn_unused_result
static inline int
rte_spinlock_trylock(rte_spinlock_t *sl)
    __rte_exclusive_trylock_function(1, sl);

#ifdef RTE_FORCE_INTRINSICS
static inline int
rte_spinlock_trylock(rte_spinlock_t *sl)
    __rte_no_thread_safety_analysis
{
    int exp = 0;
    return __atomic_compare_exchange_n(&sl->locked, &exp, 1,
                0, /* disallow spurious failure */
                __ATOMIC_ACQUIRE, __ATOMIC_RELAXED);
}
#endif

static inline int rte_spinlock_is_locked (rte_spinlock_t *sl)
{
    return __atomic_load_n(&sl->locked, __ATOMIC_ACQUIRE);
}

static inline int rte_tm_supported(void);

static inline void
rte_spinlock_lock_tm(rte_spinlock_t *sl)
    __rte_exclusive_lock_function(sl);

static inline void
rte_spinlock_unlock_tm(rte_spinlock_t *sl)
    __rte_unlock_function(sl);

__rte_warn_unused_result
static inline int
rte_spinlock_trylock_tm(rte_spinlock_t *sl)
    __rte_exclusive_trylock_function(1, sl);

typedef struct {
    rte_spinlock_t sl; 
    volatile int user; 
    volatile int count; 
} rte_spinlock_recursive_t;

#define RTE_SPINLOCK_RECURSIVE_INITIALIZER {RTE_SPINLOCK_INITIALIZER, -1, 0}

static inline void rte_spinlock_recursive_init(rte_spinlock_recursive_t *slr)
{
    rte_spinlock_init(&slr->sl);
    slr->user = -1;
    slr->count = 0;
}

static inline void rte_spinlock_recursive_lock(rte_spinlock_recursive_t *slr)
    __rte_no_thread_safety_analysis
{
    int id = rte_gettid();

    if (slr->user != id) {
        rte_spinlock_lock(&slr->sl);
        slr->user = id;
    }
    slr->count++;
}
static inline void rte_spinlock_recursive_unlock(rte_spinlock_recursive_t *slr)
    __rte_no_thread_safety_analysis
{
    if (--(slr->count) == 0) {
        slr->user = -1;
        rte_spinlock_unlock(&slr->sl);
    }

}

__rte_warn_unused_result
static inline int rte_spinlock_recursive_trylock(rte_spinlock_recursive_t *slr)
    __rte_no_thread_safety_analysis
{
    int id = rte_gettid();

    if (slr->user != id) {
        if (rte_spinlock_trylock(&slr->sl) == 0)
            return 0;
        slr->user = id;
    }
    slr->count++;
    return 1;
}


static inline void rte_spinlock_recursive_lock_tm(
    rte_spinlock_recursive_t *slr);

static inline void rte_spinlock_recursive_unlock_tm(
    rte_spinlock_recursive_t *slr);

__rte_warn_unused_result
static inline int rte_spinlock_recursive_trylock_tm(
    rte_spinlock_recursive_t *slr);

#endif /* _RTE_SPINLOCK_H_ */