--- /dev/null
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2014 Intel Corporation
+ */
+
+#ifndef _RTE_SPINLOCK_H_
+#define _RTE_SPINLOCK_H_
+
+/**
+ * @file
+ *
+ * RTE Spinlocks
+ *
+ * This file defines an API for read-write locks, which are implemented
+ * in an architecture-specific way. This kind of lock simply waits in
+ * a loop repeatedly checking until the lock becomes available.
+ *
+ * All locks must be initialised before use, and only initialised once.
+ *
+ */
+
+#include <rte_lcore.h>
+#ifdef RTE_FORCE_INTRINSICS
+#include <rte_common.h>
+#endif
+#include <rte_pause.h>
+
+/**
+ * The rte_spinlock_t type.
+ */
+typedef struct {
+ volatile int locked; /**< lock status 0 = unlocked, 1 = locked */
+} rte_spinlock_t;
+
+/**
+ * A static spinlock initializer.
+ */
+#define RTE_SPINLOCK_INITIALIZER { 0 }
+
+/**
+ * Initialize the spinlock to an unlocked state.
+ *
+ * @param sl
+ * A pointer to the spinlock.
+ */
+static inline void
+rte_spinlock_init(rte_spinlock_t *sl)
+{
+ sl->locked = 0;
+}
+
+/**
+ * Take the spinlock.
+ *
+ * @param sl
+ * A pointer to the spinlock.
+ */
+static inline void
+rte_spinlock_lock(rte_spinlock_t *sl);
+
+#ifdef RTE_FORCE_INTRINSICS
+static inline void
+rte_spinlock_lock(rte_spinlock_t *sl)
+{
+ int exp = 0;
+
+ while (!__atomic_compare_exchange_n(&sl->locked, &exp, 1, 0,
+ __ATOMIC_ACQUIRE, __ATOMIC_RELAXED)) {
+ while (__atomic_load_n(&sl->locked, __ATOMIC_RELAXED))
+ rte_pause();
+ exp = 0;
+ }
+}
+#endif
+
+/**
+ * Release the spinlock.
+ *
+ * @param sl
+ * A pointer to the spinlock.
+ */
+static inline void
+rte_spinlock_unlock (rte_spinlock_t *sl);
+
+#ifdef RTE_FORCE_INTRINSICS
+static inline void
+rte_spinlock_unlock (rte_spinlock_t *sl)
+{
+ __atomic_store_n(&sl->locked, 0, __ATOMIC_RELEASE);
+}
+#endif
+
+/**
+ * Try to take the lock.
+ *
+ * @param sl
+ * A pointer to the spinlock.
+ * @return
+ * 1 if the lock is successfully taken; 0 otherwise.
+ */
+static inline int
+rte_spinlock_trylock (rte_spinlock_t *sl);
+
+#ifdef RTE_FORCE_INTRINSICS
+static inline int
+rte_spinlock_trylock (rte_spinlock_t *sl)
+{
+ int exp = 0;
+ return __atomic_compare_exchange_n(&sl->locked, &exp, 1,
+ 0, /* disallow spurious failure */
+ __ATOMIC_ACQUIRE, __ATOMIC_RELAXED);
+}
+#endif
+
+/**
+ * Test if the lock is taken.
+ *
+ * @param sl
+ * A pointer to the spinlock.
+ * @return
+ * 1 if the lock is currently taken; 0 otherwise.
+ */
+static inline int rte_spinlock_is_locked (rte_spinlock_t *sl)
+{
+ return __atomic_load_n(&sl->locked, __ATOMIC_ACQUIRE);
+}
+
+/**
+ * Test if hardware transactional memory (lock elision) is supported
+ *
+ * @return
+ * 1 if the hardware transactional memory is supported; 0 otherwise.
+ */
+static inline int rte_tm_supported(void);
+
+/**
+ * Try to execute critical section in a hardware memory transaction,
+ * if it fails or not available take the spinlock.
+ *
+ * NOTE: An attempt to perform a HW I/O operation inside a hardware memory
+ * transaction always aborts the transaction since the CPU is not able to
+ * roll-back should the transaction fail. Therefore, hardware transactional
+ * locks are not advised to be used around rte_eth_rx_burst() and
+ * rte_eth_tx_burst() calls.
+ *
+ * @param sl
+ * A pointer to the spinlock.
+ */
+static inline void
+rte_spinlock_lock_tm(rte_spinlock_t *sl);
+
+/**
+ * Commit hardware memory transaction or release the spinlock if
+ * the spinlock is used as a fall-back
+ *
+ * @param sl
+ * A pointer to the spinlock.
+ */
+static inline void
+rte_spinlock_unlock_tm(rte_spinlock_t *sl);
+
+/**
+ * Try to execute critical section in a hardware memory transaction,
+ * if it fails or not available try to take the lock.
+ *
+ * NOTE: An attempt to perform a HW I/O operation inside a hardware memory
+ * transaction always aborts the transaction since the CPU is not able to
+ * roll-back should the transaction fail. Therefore, hardware transactional
+ * locks are not advised to be used around rte_eth_rx_burst() and
+ * rte_eth_tx_burst() calls.
+ *
+ * @param sl
+ * A pointer to the spinlock.
+ * @return
+ * 1 if the hardware memory transaction is successfully started
+ * or lock is successfully taken; 0 otherwise.
+ */
+static inline int
+rte_spinlock_trylock_tm(rte_spinlock_t *sl);
+
+/**
+ * The rte_spinlock_recursive_t type.
+ */
+typedef struct {
+ rte_spinlock_t sl; /**< the actual spinlock */
+ volatile int user; /**< core id using lock, -1 for unused */
+ volatile int count; /**< count of time this lock has been called */
+} rte_spinlock_recursive_t;
+
+/**
+ * A static recursive spinlock initializer.
+ */
+#define RTE_SPINLOCK_RECURSIVE_INITIALIZER {RTE_SPINLOCK_INITIALIZER, -1, 0}
+
+/**
+ * Initialize the recursive spinlock to an unlocked state.
+ *
+ * @param slr
+ * A pointer to the recursive spinlock.
+ */
+static inline void rte_spinlock_recursive_init(rte_spinlock_recursive_t *slr)
+{
+ rte_spinlock_init(&slr->sl);
+ slr->user = -1;
+ slr->count = 0;
+}
+
+/**
+ * Take the recursive spinlock.
+ *
+ * @param slr
+ * A pointer to the recursive spinlock.
+ */
+static inline void rte_spinlock_recursive_lock(rte_spinlock_recursive_t *slr)
+{
+ int id = rte_gettid();
+
+ if (slr->user != id) {
+ rte_spinlock_lock(&slr->sl);
+ slr->user = id;
+ }
+ slr->count++;
+}
+/**
+ * Release the recursive spinlock.
+ *
+ * @param slr
+ * A pointer to the recursive spinlock.
+ */
+static inline void rte_spinlock_recursive_unlock(rte_spinlock_recursive_t *slr)
+{
+ if (--(slr->count) == 0) {
+ slr->user = -1;
+ rte_spinlock_unlock(&slr->sl);
+ }
+
+}
+
+/**
+ * Try to take the recursive lock.
+ *
+ * @param slr
+ * A pointer to the recursive spinlock.
+ * @return
+ * 1 if the lock is successfully taken; 0 otherwise.
+ */
+static inline int rte_spinlock_recursive_trylock(rte_spinlock_recursive_t *slr)
+{
+ int id = rte_gettid();
+
+ if (slr->user != id) {
+ if (rte_spinlock_trylock(&slr->sl) == 0)
+ return 0;
+ slr->user = id;
+ }
+ slr->count++;
+ return 1;
+}
+
+
+/**
+ * Try to execute critical section in a hardware memory transaction,
+ * if it fails or not available take the recursive spinlocks
+ *
+ * NOTE: An attempt to perform a HW I/O operation inside a hardware memory
+ * transaction always aborts the transaction since the CPU is not able to
+ * roll-back should the transaction fail. Therefore, hardware transactional
+ * locks are not advised to be used around rte_eth_rx_burst() and
+ * rte_eth_tx_burst() calls.
+ *
+ * @param slr
+ * A pointer to the recursive spinlock.
+ */
+static inline void rte_spinlock_recursive_lock_tm(
+ rte_spinlock_recursive_t *slr);
+
+/**
+ * Commit hardware memory transaction or release the recursive spinlock
+ * if the recursive spinlock is used as a fall-back
+ *
+ * @param slr
+ * A pointer to the recursive spinlock.
+ */
+static inline void rte_spinlock_recursive_unlock_tm(
+ rte_spinlock_recursive_t *slr);
+
+/**
+ * Try to execute critical section in a hardware memory transaction,
+ * if it fails or not available try to take the recursive lock
+ *
+ * NOTE: An attempt to perform a HW I/O operation inside a hardware memory
+ * transaction always aborts the transaction since the CPU is not able to
+ * roll-back should the transaction fail. Therefore, hardware transactional
+ * locks are not advised to be used around rte_eth_rx_burst() and
+ * rte_eth_tx_burst() calls.
+ *
+ * @param slr
+ * A pointer to the recursive spinlock.
+ * @return
+ * 1 if the hardware memory transaction is successfully started
+ * or lock is successfully taken; 0 otherwise.
+ */
+static inline int rte_spinlock_recursive_trylock_tm(
+ rte_spinlock_recursive_t *slr);
+
+#endif /* _RTE_SPINLOCK_H_ */
projects / ceph.git / blobdiff