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Diffstat (limited to 'lib/librte_eventdev/rte_event_ring.h')
| -rw-r--r-- | lib/librte_eventdev/rte_event_ring.h | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/lib/librte_eventdev/rte_event_ring.h b/lib/librte_eventdev/rte_event_ring.h new file mode 100644 index 00000000..ea9b6885 --- /dev/null +++ b/lib/librte_eventdev/rte_event_ring.h @@ -0,0 +1,308 @@ +/*- + * 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 |