rte_ring_elem_pvt.h

/* SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2017,2018 HXT-semitech Corporation.
 * 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_ELEM_PVT_H_
#define _RTE_RING_ELEM_PVT_H_

static __rte_always_inline void
__rte_ring_enqueue_elems_32(struct rte_ring *r, const uint32_t size,
        uint32_t idx, const void *obj_table, uint32_t n)
{
    unsigned int i;
    uint32_t *ring = (uint32_t *)&r[1];
    const uint32_t *obj = (const uint32_t *)obj_table;
    if (likely(idx + n < size)) {
        for (i = 0; i < (n & ~0x7); i += 8, idx += 8) {
            ring[idx] = obj[i];
            ring[idx + 1] = obj[i + 1];
            ring[idx + 2] = obj[i + 2];
            ring[idx + 3] = obj[i + 3];
            ring[idx + 4] = obj[i + 4];
            ring[idx + 5] = obj[i + 5];
            ring[idx + 6] = obj[i + 6];
            ring[idx + 7] = obj[i + 7];
        }
        switch (n & 0x7) {
        case 7:
            ring[idx++] = obj[i++]; /* fallthrough */
        case 6:
            ring[idx++] = obj[i++]; /* fallthrough */
        case 5:
            ring[idx++] = obj[i++]; /* fallthrough */
        case 4:
            ring[idx++] = obj[i++]; /* fallthrough */
        case 3:
            ring[idx++] = obj[i++]; /* fallthrough */
        case 2:
            ring[idx++] = obj[i++]; /* fallthrough */
        case 1:
            ring[idx++] = obj[i++]; /* fallthrough */
        }
    } else {
        for (i = 0; idx < size; i++, idx++)
            ring[idx] = obj[i];
        /* Start at the beginning */
        for (idx = 0; i < n; i++, idx++)
            ring[idx] = obj[i];
    }
}

static __rte_always_inline void
__rte_ring_enqueue_elems_64(struct rte_ring *r, uint32_t prod_head,
        const void *obj_table, uint32_t n)
{
    unsigned int i;
    const uint32_t size = r->size;
    uint32_t idx = prod_head & r->mask;
    uint64_t *ring = (uint64_t *)&r[1];
    const unaligned_uint64_t *obj = (const unaligned_uint64_t *)obj_table;
    if (likely(idx + n < size)) {
        for (i = 0; i < (n & ~0x3); i += 4, idx += 4) {
            ring[idx] = obj[i];
            ring[idx + 1] = obj[i + 1];
            ring[idx + 2] = obj[i + 2];
            ring[idx + 3] = obj[i + 3];
        }
        switch (n & 0x3) {
        case 3:
            ring[idx++] = obj[i++]; /* fallthrough */
        case 2:
            ring[idx++] = obj[i++]; /* fallthrough */
        case 1:
            ring[idx++] = obj[i++];
        }
    } else {
        for (i = 0; idx < size; i++, idx++)
            ring[idx] = obj[i];
        /* Start at the beginning */
        for (idx = 0; i < n; i++, idx++)
            ring[idx] = obj[i];
    }
}

static __rte_always_inline void
__rte_ring_enqueue_elems_128(struct rte_ring *r, uint32_t prod_head,
        const void *obj_table, uint32_t n)
{
    unsigned int i;
    const uint32_t size = r->size;
    uint32_t idx = prod_head & r->mask;
    rte_int128_t *ring = (rte_int128_t *)&r[1];
    const rte_int128_t *obj = (const rte_int128_t *)obj_table;
    if (likely(idx + n < size)) {
        for (i = 0; i < (n & ~0x1); i += 2, idx += 2)
            memcpy((void *)(ring + idx),
                (const void *)(obj + i), 32);
        switch (n & 0x1) {
        case 1:
            memcpy((void *)(ring + idx),
                (const void *)(obj + i), 16);
        }
    } else {
        for (i = 0; idx < size; i++, idx++)
            memcpy((void *)(ring + idx),
                (const void *)(obj + i), 16);
        /* Start at the beginning */
        for (idx = 0; i < n; i++, idx++)
            memcpy((void *)(ring + idx),
                (const void *)(obj + i), 16);
    }
}

/* the actual enqueue of elements on the ring.
 * Placed here since identical code needed in both
 * single and multi producer enqueue functions.
 */
static __rte_always_inline void
__rte_ring_enqueue_elems(struct rte_ring *r, uint32_t prod_head,
        const void *obj_table, uint32_t esize, uint32_t num)
{
    /* 8B and 16B copies implemented individually to retain
     * the current performance.
     */
    if (esize == 8)
        __rte_ring_enqueue_elems_64(r, prod_head, obj_table, num);
    else if (esize == 16)
        __rte_ring_enqueue_elems_128(r, prod_head, obj_table, num);
    else {
        uint32_t idx, scale, nr_idx, nr_num, nr_size;

        /* Normalize to uint32_t */
        scale = esize / sizeof(uint32_t);
        nr_num = num * scale;
        idx = prod_head & r->mask;
        nr_idx = idx * scale;
        nr_size = r->size * scale;
        __rte_ring_enqueue_elems_32(r, nr_size, nr_idx,
                obj_table, nr_num);
    }
}

static __rte_always_inline void
__rte_ring_dequeue_elems_32(struct rte_ring *r, const uint32_t size,
        uint32_t idx, void *obj_table, uint32_t n)
{
    unsigned int i;
    uint32_t *ring = (uint32_t *)&r[1];
    uint32_t *obj = (uint32_t *)obj_table;
    if (likely(idx + n < size)) {
        for (i = 0; i < (n & ~0x7); i += 8, idx += 8) {
            obj[i] = ring[idx];
            obj[i + 1] = ring[idx + 1];
            obj[i + 2] = ring[idx + 2];
            obj[i + 3] = ring[idx + 3];
            obj[i + 4] = ring[idx + 4];
            obj[i + 5] = ring[idx + 5];
            obj[i + 6] = ring[idx + 6];
            obj[i + 7] = ring[idx + 7];
        }
        switch (n & 0x7) {
        case 7:
            obj[i++] = ring[idx++]; /* fallthrough */
        case 6:
            obj[i++] = ring[idx++]; /* fallthrough */
        case 5:
            obj[i++] = ring[idx++]; /* fallthrough */
        case 4:
            obj[i++] = ring[idx++]; /* fallthrough */
        case 3:
            obj[i++] = ring[idx++]; /* fallthrough */
        case 2:
            obj[i++] = ring[idx++]; /* fallthrough */
        case 1:
            obj[i++] = ring[idx++]; /* fallthrough */
        }
    } else {
        for (i = 0; idx < size; i++, idx++)
            obj[i] = ring[idx];
        /* Start at the beginning */
        for (idx = 0; i < n; i++, idx++)
            obj[i] = ring[idx];
    }
}

static __rte_always_inline void
__rte_ring_dequeue_elems_64(struct rte_ring *r, uint32_t prod_head,
        void *obj_table, uint32_t n)
{
    unsigned int i;
    const uint32_t size = r->size;
    uint32_t idx = prod_head & r->mask;
    uint64_t *ring = (uint64_t *)&r[1];
    unaligned_uint64_t *obj = (unaligned_uint64_t *)obj_table;
    if (likely(idx + n < size)) {
        for (i = 0; i < (n & ~0x3); i += 4, idx += 4) {
            obj[i] = ring[idx];
            obj[i + 1] = ring[idx + 1];
            obj[i + 2] = ring[idx + 2];
            obj[i + 3] = ring[idx + 3];
        }
        switch (n & 0x3) {
        case 3:
            obj[i++] = ring[idx++]; /* fallthrough */
        case 2:
            obj[i++] = ring[idx++]; /* fallthrough */
        case 1:
            obj[i++] = ring[idx++]; /* fallthrough */
        }
    } else {
        for (i = 0; idx < size; i++, idx++)
            obj[i] = ring[idx];
        /* Start at the beginning */
        for (idx = 0; i < n; i++, idx++)
            obj[i] = ring[idx];
    }
}

static __rte_always_inline void
__rte_ring_dequeue_elems_128(struct rte_ring *r, uint32_t prod_head,
        void *obj_table, uint32_t n)
{
    unsigned int i;
    const uint32_t size = r->size;
    uint32_t idx = prod_head & r->mask;
    rte_int128_t *ring = (rte_int128_t *)&r[1];
    rte_int128_t *obj = (rte_int128_t *)obj_table;
    if (likely(idx + n < size)) {
        for (i = 0; i < (n & ~0x1); i += 2, idx += 2)
            memcpy((void *)(obj + i), (void *)(ring + idx), 32);
        switch (n & 0x1) {
        case 1:
            memcpy((void *)(obj + i), (void *)(ring + idx), 16);
        }
    } else {
        for (i = 0; idx < size; i++, idx++)
            memcpy((void *)(obj + i), (void *)(ring + idx), 16);
        /* Start at the beginning */
        for (idx = 0; i < n; i++, idx++)
            memcpy((void *)(obj + i), (void *)(ring + idx), 16);
    }
}

/* the actual dequeue of elements from the ring.
 * Placed here since identical code needed in both
 * single and multi producer enqueue functions.
 */
static __rte_always_inline void
__rte_ring_dequeue_elems(struct rte_ring *r, uint32_t cons_head,
        void *obj_table, uint32_t esize, uint32_t num)
{
    /* 8B and 16B copies implemented individually to retain
     * the current performance.
     */
    if (esize == 8)
        __rte_ring_dequeue_elems_64(r, cons_head, obj_table, num);
    else if (esize == 16)
        __rte_ring_dequeue_elems_128(r, cons_head, obj_table, num);
    else {
        uint32_t idx, scale, nr_idx, nr_num, nr_size;

        /* Normalize to uint32_t */
        scale = esize / sizeof(uint32_t);
        nr_num = num * scale;
        idx = cons_head & r->mask;
        nr_idx = idx * scale;
        nr_size = r->size * scale;
        __rte_ring_dequeue_elems_32(r, nr_size, nr_idx,
                obj_table, nr_num);
    }
}

/* Between load and load. there might be cpu reorder in weak model
 * (powerpc/arm).
 * There are 2 choices for the users
 * 1.use rmb() memory barrier
 * 2.use one-direction load_acquire/store_release barrier
 * It depends on performance test results.
 */
#ifdef RTE_USE_C11_MEM_MODEL
#include "rte_ring_c11_pvt.h"
#else
#include "rte_ring_generic_pvt.h"
#endif

static __rte_always_inline unsigned int
__rte_ring_do_enqueue_elem(struct rte_ring *r, const void *obj_table,
        unsigned int esize, unsigned int n,
        enum rte_ring_queue_behavior behavior, unsigned int is_sp,
        unsigned int *free_space)
{
    uint32_t prod_head, prod_next;
    uint32_t free_entries;

    n = __rte_ring_move_prod_head(r, is_sp, n, behavior,
            &prod_head, &prod_next, &free_entries);
    if (n == 0)
        goto end;

    __rte_ring_enqueue_elems(r, prod_head, obj_table, esize, n);

    __rte_ring_update_tail(&r->prod, prod_head, prod_next, is_sp, 1);
end:
    if (free_space != NULL)
        *free_space = free_entries - n;
    return n;
}

static __rte_always_inline unsigned int
__rte_ring_do_dequeue_elem(struct rte_ring *r, void *obj_table,
        unsigned int esize, unsigned int n,
        enum rte_ring_queue_behavior behavior, unsigned int is_sc,
        unsigned int *available)
{
    uint32_t cons_head, cons_next;
    uint32_t entries;

    n = __rte_ring_move_cons_head(r, (int)is_sc, n, behavior,
            &cons_head, &cons_next, &entries);
    if (n == 0)
        goto end;

    __rte_ring_dequeue_elems(r, cons_head, obj_table, esize, n);

    __rte_ring_update_tail(&r->cons, cons_head, cons_next, is_sc, 0);

end:
    if (available != NULL)
        *available = entries - n;
    return n;
}

#endif /* _RTE_RING_ELEM_PVT_H_ */