// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2018-2025, Advanced Micro Devices, Inc. */

#include <linux/dma-mapping.h>

#include "ionic_queue.h"

int ionic_queue_init(struct ionic_queue *q, struct device *dma_dev,
                     int depth, size_t stride)
{
        if (depth < 0 || depth > 0xffff)
                return -EINVAL;

        if (stride == 0 || stride > 0x10000)
                return -EINVAL;

        if (depth == 0)
                depth = 1;

        q->depth_log2 = order_base_2(depth + 1);
        q->stride_log2 = order_base_2(stride);

        if (q->depth_log2 + q->stride_log2 < PAGE_SHIFT)
                q->depth_log2 = PAGE_SHIFT - q->stride_log2;

        if (q->depth_log2 > 16 || q->stride_log2 > 16)
                return -EINVAL;

        q->size = BIT_ULL(q->depth_log2 + q->stride_log2);
        q->mask = BIT(q->depth_log2) - 1;

        q->ptr = dma_alloc_coherent(dma_dev, q->size, &q->dma, GFP_KERNEL);
        if (!q->ptr)
                return -ENOMEM;

        /* it will always be page aligned, but just to be sure... */
        if (!PAGE_ALIGNED(q->ptr)) {
                dma_free_coherent(dma_dev, q->size, q->ptr, q->dma);
                return -ENOMEM;
        }

        q->prod = 0;
        q->cons = 0;
        q->dbell = 0;

        return 0;
}

void ionic_queue_destroy(struct ionic_queue *q, struct device *dma_dev)
{
        dma_free_coherent(dma_dev, q->size, q->ptr, q->dma);
}