rte_ring_peek_zc.h

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/* SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2020 Arm Limited
 * Copyright (c) 2007-2009 Kip Macy kmacy@freebsd.org
 * All rights reserved.
 * Derived from FreeBSD's bufring.h
 * Used as BSD-3 Licensed with permission from Kip Macy.
 */

#ifndef _RTE_RING_PEEK_ZC_H_
#define _RTE_RING_PEEK_ZC_H_

#ifdef __cplusplus
extern "C" {
#endif

#include <rte_ring_peek_elem_pvt.h>

struct rte_ring_zc_data {
    /* Pointer to the first space in the ring */
    void *ptr1;
    /* Pointer to the second space in the ring if there is wrap-around.
     * It contains valid value only if wrap-around happens.
     */
    void *ptr2;
    /* Number of elements in the first pointer. If this is equal to
     * the number of elements requested, then ptr2 is NULL.
     * Otherwise, subtracting n1 from number of elements requested
     * will give the number of elements available at ptr2.
     */
    unsigned int n1;
} __rte_cache_aligned;

static __rte_always_inline void
__rte_ring_get_elem_addr(struct rte_ring *r, uint32_t head,
    uint32_t esize, uint32_t num, void **dst1, uint32_t *n1, void **dst2)
{
    uint32_t idx, scale, nr_idx;
    uint32_t *ring = (uint32_t *)&r[1];

    /* Normalize to uint32_t */
    scale = esize / sizeof(uint32_t);
    idx = head & r->mask;
    nr_idx = idx * scale;

    *dst1 = ring + nr_idx;
    *n1 = num;

    if (idx + num > r->size) {
        *n1 = r->size - idx;
        *dst2 = ring;
    } else {
        *dst2 = NULL;
    }
}

static __rte_always_inline unsigned int
__rte_ring_do_enqueue_zc_elem_start(struct rte_ring *r, unsigned int esize,
        uint32_t n, enum rte_ring_queue_behavior behavior,
        struct rte_ring_zc_data *zcd, unsigned int *free_space)
{
    uint32_t free, head, next;

    switch (r->prod.sync_type) {
    case RTE_RING_SYNC_ST:
        n = __rte_ring_move_prod_head(r, RTE_RING_SYNC_ST, n,
            behavior, &head, &next, &free);
        break;
    case RTE_RING_SYNC_MT_HTS:
        n = __rte_ring_hts_move_prod_head(r, n, behavior, &head, &free);
        break;
    case RTE_RING_SYNC_MT:
    case RTE_RING_SYNC_MT_RTS:
    default:
        /* unsupported mode, shouldn't be here */
        RTE_ASSERT(0);
        n = 0;
        free = 0;
        return n;
    }

    __rte_ring_get_elem_addr(r, head, esize, n, &zcd->ptr1,
        &zcd->n1, &zcd->ptr2);

    if (free_space != NULL)
        *free_space = free - n;
    return n;
}

static __rte_always_inline unsigned int
rte_ring_enqueue_zc_bulk_elem_start(struct rte_ring *r, unsigned int esize,
    unsigned int n, struct rte_ring_zc_data *zcd, unsigned int *free_space)
{
    return __rte_ring_do_enqueue_zc_elem_start(r, esize, n,
            RTE_RING_QUEUE_FIXED, zcd, free_space);
}

static __rte_always_inline unsigned int
rte_ring_enqueue_zc_bulk_start(struct rte_ring *r, unsigned int n,
    struct rte_ring_zc_data *zcd, unsigned int *free_space)
{
    return rte_ring_enqueue_zc_bulk_elem_start(r, sizeof(uintptr_t), n,
                            zcd, free_space);
}

static __rte_always_inline unsigned int
rte_ring_enqueue_zc_burst_elem_start(struct rte_ring *r, unsigned int esize,
    unsigned int n, struct rte_ring_zc_data *zcd, unsigned int *free_space)
{
    return __rte_ring_do_enqueue_zc_elem_start(r, esize, n,
            RTE_RING_QUEUE_VARIABLE, zcd, free_space);
}

static __rte_always_inline unsigned int
rte_ring_enqueue_zc_burst_start(struct rte_ring *r, unsigned int n,
    struct rte_ring_zc_data *zcd, unsigned int *free_space)
{
    return rte_ring_enqueue_zc_burst_elem_start(r, sizeof(uintptr_t), n,
                            zcd, free_space);
}

static __rte_always_inline void
rte_ring_enqueue_zc_elem_finish(struct rte_ring *r, unsigned int n)
{
    uint32_t tail;

    switch (r->prod.sync_type) {
    case RTE_RING_SYNC_ST:
        n = __rte_ring_st_get_tail(&r->prod, &tail, n);
        __rte_ring_st_set_head_tail(&r->prod, tail, n, 1);
        break;
    case RTE_RING_SYNC_MT_HTS:
        n = __rte_ring_hts_get_tail(&r->hts_prod, &tail, n);
        __rte_ring_hts_set_head_tail(&r->hts_prod, tail, n, 1);
        break;
    case RTE_RING_SYNC_MT:
    case RTE_RING_SYNC_MT_RTS:
    default:
        /* unsupported mode, shouldn't be here */
        RTE_ASSERT(0);
    }
}

static __rte_always_inline void
rte_ring_enqueue_zc_finish(struct rte_ring *r, unsigned int n)
{
    rte_ring_enqueue_zc_elem_finish(r, n);
}

static __rte_always_inline unsigned int
__rte_ring_do_dequeue_zc_elem_start(struct rte_ring *r,
    uint32_t esize, uint32_t n, enum rte_ring_queue_behavior behavior,
    struct rte_ring_zc_data *zcd, unsigned int *available)
{
    uint32_t avail, head, next;

    switch (r->cons.sync_type) {
    case RTE_RING_SYNC_ST:
        n = __rte_ring_move_cons_head(r, RTE_RING_SYNC_ST, n,
            behavior, &head, &next, &avail);
        break;
    case RTE_RING_SYNC_MT_HTS:
        n = __rte_ring_hts_move_cons_head(r, n, behavior,
            &head, &avail);
        break;
    case RTE_RING_SYNC_MT:
    case RTE_RING_SYNC_MT_RTS:
    default:
        /* unsupported mode, shouldn't be here */
        RTE_ASSERT(0);
        n = 0;
        avail = 0;
        return n;
    }

    __rte_ring_get_elem_addr(r, head, esize, n, &zcd->ptr1,
        &zcd->n1, &zcd->ptr2);

    if (available != NULL)
        *available = avail - n;
    return n;
}

static __rte_always_inline unsigned int
rte_ring_dequeue_zc_bulk_elem_start(struct rte_ring *r, unsigned int esize,
    unsigned int n, struct rte_ring_zc_data *zcd, unsigned int *available)
{
    return __rte_ring_do_dequeue_zc_elem_start(r, esize, n,
            RTE_RING_QUEUE_FIXED, zcd, available);
}

static __rte_always_inline unsigned int
rte_ring_dequeue_zc_bulk_start(struct rte_ring *r, unsigned int n,
    struct rte_ring_zc_data *zcd, unsigned int *available)
{
    return rte_ring_dequeue_zc_bulk_elem_start(r, sizeof(uintptr_t),
        n, zcd, available);
}

static __rte_always_inline unsigned int
rte_ring_dequeue_zc_burst_elem_start(struct rte_ring *r, unsigned int esize,
    unsigned int n, struct rte_ring_zc_data *zcd, unsigned int *available)
{
    return __rte_ring_do_dequeue_zc_elem_start(r, esize, n,
            RTE_RING_QUEUE_VARIABLE, zcd, available);
}

static __rte_always_inline unsigned int
rte_ring_dequeue_zc_burst_start(struct rte_ring *r, unsigned int n,
        struct rte_ring_zc_data *zcd, unsigned int *available)
{
    return rte_ring_dequeue_zc_burst_elem_start(r, sizeof(uintptr_t), n,
            zcd, available);
}

static __rte_always_inline void
rte_ring_dequeue_zc_elem_finish(struct rte_ring *r, unsigned int n)
{
    uint32_t tail;

    switch (r->cons.sync_type) {
    case RTE_RING_SYNC_ST:
        n = __rte_ring_st_get_tail(&r->cons, &tail, n);
        __rte_ring_st_set_head_tail(&r->cons, tail, n, 0);
        break;
    case RTE_RING_SYNC_MT_HTS:
        n = __rte_ring_hts_get_tail(&r->hts_cons, &tail, n);
        __rte_ring_hts_set_head_tail(&r->hts_cons, tail, n, 0);
        break;
    case RTE_RING_SYNC_MT:
    case RTE_RING_SYNC_MT_RTS:
    default:
        /* unsupported mode, shouldn't be here */
        RTE_ASSERT(0);
    }
}

static __rte_always_inline void
rte_ring_dequeue_zc_finish(struct rte_ring *r, unsigned int n)
{
    rte_ring_dequeue_elem_finish(r, n);
}

#ifdef __cplusplus
}
#endif

#endif /* _RTE_RING_PEEK_ZC_H_ */