--- /dev/null
+/*-
+ * BSD LICENSE
+ *
+ * Copyright(c) 2016-2017 Intel Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * @file
+ * RTE Event Ring
+ *
+ * This provides a ring implementation for passing rte_event structures
+ * from one core to another.
+ */
+
+#ifndef _RTE_EVENT_RING_
+#define _RTE_EVENT_RING_
+
+#include <stdint.h>
+
+#include <rte_common.h>
+#include <rte_memory.h>
+#include <rte_malloc.h>
+#include <rte_ring.h>
+#include "rte_eventdev.h"
+
+#define RTE_TAILQ_EVENT_RING_NAME "RTE_EVENT_RING"
+
+/**
+ * Generic ring structure for passing rte_event objects from core to core.
+ *
+ * Based on the primitives given in the rte_ring library. Designed to be
+ * used inside software eventdev implementations and by applications
+ * directly as needed.
+ */
+struct rte_event_ring {
+ struct rte_ring r;
+};
+
+/**
+ * Returns the number of events in the ring
+ *
+ * @param r
+ * pointer to the event ring
+ * @return
+ * the number of events in the ring
+ */
+static __rte_always_inline unsigned int
+rte_event_ring_count(const struct rte_event_ring *r)
+{
+ return rte_ring_count(&r->r);
+}
+
+/**
+ * Returns the amount of free space in the ring
+ *
+ * @param r
+ * pointer to the event ring
+ * @return
+ * the number of free slots in the ring, i.e. the number of events that
+ * can be successfully enqueued before dequeue must be called
+ */
+static __rte_always_inline unsigned int
+rte_event_ring_free_count(const struct rte_event_ring *r)
+{
+ return rte_ring_free_count(&r->r);
+}
+
+/**
+ * Enqueue a set of events onto a ring
+ *
+ * Note: this API enqueues by copying the events themselves onto the ring,
+ * rather than just placing a pointer to each event onto the ring. This
+ * means that statically-allocated events can safely be enqueued by this
+ * API.
+ *
+ * @param r
+ * pointer to the event ring
+ * @param events
+ * pointer to an array of struct rte_event objects
+ * @param n
+ * number of events in the array to enqueue
+ * @param free_space
+ * if non-null, is updated to indicate the amount of free space in the
+ * ring once the enqueue has completed.
+ * @return
+ * the number of elements, n', enqueued to the ring, 0 <= n' <= n
+ */
+static __rte_always_inline unsigned int
+rte_event_ring_enqueue_burst(struct rte_event_ring *r,
+ const struct rte_event *events,
+ unsigned int n, uint16_t *free_space)
+{
+ uint32_t prod_head, prod_next;
+ uint32_t free_entries;
+
+ n = __rte_ring_move_prod_head(&r->r, r->r.prod.single, n,
+ RTE_RING_QUEUE_VARIABLE,
+ &prod_head, &prod_next, &free_entries);
+ if (n == 0)
+ goto end;
+
+ ENQUEUE_PTRS(&r->r, &r[1], prod_head, events, n, struct rte_event);
+ rte_smp_wmb();
+
+ update_tail(&r->r.prod, prod_head, prod_next, 1);
+end:
+ if (free_space != NULL)
+ *free_space = free_entries - n;
+ return n;
+}
+
+/**
+ * Dequeue a set of events from a ring
+ *
+ * Note: this API does not work with pointers to events, rather it copies
+ * the events themselves to the destination ``events`` buffer.
+ *
+ * @param r
+ * pointer to the event ring
+ * @param events
+ * pointer to an array to hold the struct rte_event objects
+ * @param n
+ * number of events that can be held in the ``events`` array
+ * @param available
+ * if non-null, is updated to indicate the number of events remaining in
+ * the ring once the dequeue has completed
+ * @return
+ * the number of elements, n', dequeued from the ring, 0 <= n' <= n
+ */
+static __rte_always_inline unsigned int
+rte_event_ring_dequeue_burst(struct rte_event_ring *r,
+ struct rte_event *events,
+ unsigned int n, uint16_t *available)
+{
+ uint32_t cons_head, cons_next;
+ uint32_t entries;
+
+ n = __rte_ring_move_cons_head(&r->r, r->r.cons.single, n,
+ RTE_RING_QUEUE_VARIABLE,
+ &cons_head, &cons_next, &entries);
+ if (n == 0)
+ goto end;
+
+ DEQUEUE_PTRS(&r->r, &r[1], cons_head, events, n, struct rte_event);
+ rte_smp_rmb();
+
+ update_tail(&r->r.cons, cons_head, cons_next, 1);
+
+end:
+ if (available != NULL)
+ *available = entries - n;
+ return n;
+}
+
+/*
+ * Initializes an already-allocated ring structure
+ *
+ * @param r
+ * pointer to the ring memory to be initialized
+ * @param name
+ * name to be given to the ring
+ * @param count
+ * the number of elements to be stored in the ring. If the flag
+ * ``RING_F_EXACT_SZ`` is not set, this must be a power of 2, and the actual
+ * usable space in the ring will be ``count - 1`` entries. If the flag
+ * ``RING_F_EXACT_SZ`` is set, the this can be any value up to the ring size
+ * limit - 1, and the usable space will be exactly that requested.
+ * @param flags
+ * An OR of the following:
+ * - RING_F_SP_ENQ: If this flag is set, the default behavior when
+ * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()``
+ * is "single-producer". Otherwise, it is "multi-producers".
+ * - RING_F_SC_DEQ: If this flag is set, the default behavior when
+ * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()``
+ * is "single-consumer". Otherwise, it is "multi-consumers".
+ * - RING_F_EXACT_SZ: If this flag is set, the ``count`` parameter is to
+ * be taken as the exact usable size of the ring, and as such does not
+ * need to be a power of 2. The underlying ring memory should be a
+ * power-of-2 size greater than the count value.
+ * @return
+ * 0 on success, or a negative value on error.
+ */
+int
+rte_event_ring_init(struct rte_event_ring *r, const char *name,
+ unsigned int count, unsigned int flags);
+
+/*
+ * Create an event ring structure
+ *
+ * This function allocates memory and initializes an event ring inside that
+ * memory.
+ *
+ * @param name
+ * name to be given to the ring
+ * @param count
+ * the number of elements to be stored in the ring. If the flag
+ * ``RING_F_EXACT_SZ`` is not set, this must be a power of 2, and the actual
+ * usable space in the ring will be ``count - 1`` entries. If the flag
+ * ``RING_F_EXACT_SZ`` is set, the this can be any value up to the ring size
+ * limit - 1, and the usable space will be exactly that requested.
+ * @param socket_id
+ * The *socket_id* argument is the socket identifier in case of
+ * NUMA. The value can be *SOCKET_ID_ANY* if there is no NUMA
+ * constraint for the reserved zone.
+ * @param flags
+ * An OR of the following:
+ * - RING_F_SP_ENQ: If this flag is set, the default behavior when
+ * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()``
+ * is "single-producer". Otherwise, it is "multi-producers".
+ * - RING_F_SC_DEQ: If this flag is set, the default behavior when
+ * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()``
+ * is "single-consumer". Otherwise, it is "multi-consumers".
+ * - RING_F_EXACT_SZ: If this flag is set, the ``count`` parameter is to
+ * be taken as the exact usable size of the ring, and as such does not
+ * need to be a power of 2. The underlying ring memory should be a
+ * power-of-2 size greater than the count value.
+ * @return
+ * On success, the pointer to the new allocated ring. NULL on error with
+ * rte_errno set appropriately. Possible errno values include:
+ * - E_RTE_NO_CONFIG - function could not get pointer to rte_config structure
+ * - E_RTE_SECONDARY - function was called from a secondary process instance
+ * - EINVAL - count provided is not a power of 2
+ * - ENOSPC - the maximum number of memzones has already been allocated
+ * - EEXIST - a memzone with the same name already exists
+ * - ENOMEM - no appropriate memory area found in which to create memzone
+ */
+struct rte_event_ring *
+rte_event_ring_create(const char *name, unsigned int count, int socket_id,
+ unsigned int flags);
+
+/**
+ * Search for an event ring based on its name
+ *
+ * @param name
+ * The name of the ring.
+ * @return
+ * The pointer to the ring matching the name, or NULL if not found,
+ * with rte_errno set appropriately. Possible rte_errno values include:
+ * - ENOENT - required entry not available to return.
+ */
+struct rte_event_ring *
+rte_event_ring_lookup(const char *name);
+
+/**
+ * De-allocate all memory used by the ring.
+ *
+ * @param r
+ * Ring to free
+ */
+void
+rte_event_ring_free(struct rte_event_ring *r);
+
+/**
+ * Return the size of the event ring.
+ *
+ * @param r
+ * A pointer to the ring structure.
+ * @return
+ * The size of the data store used by the ring.
+ * NOTE: this is not the same as the usable space in the ring. To query that
+ * use ``rte_ring_get_capacity()``.
+ */
+static inline unsigned int
+rte_event_ring_get_size(const struct rte_event_ring *r)
+{
+ return rte_ring_get_size(&r->r);
+}
+
+/**
+ * Return the number of elements which can be stored in the event ring.
+ *
+ * @param r
+ * A pointer to the ring structure.
+ * @return
+ * The usable size of the ring.
+ */
+static inline unsigned int
+rte_event_ring_get_capacity(const struct rte_event_ring *r)
+{
+ return rte_ring_get_capacity(&r->r);
+}
+#endif
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