// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Intel Corporation

#include <linux/device.h>

#include "ipu3.h"
#include "ipu3-css-pool.h"
#include "ipu3-dmamap.h"

int imgu_css_dma_buffer_resize(struct imgu_device *imgu,
                               struct imgu_css_map *map, size_t size)
{
        if (map->size < size && map->vaddr) {
                dev_warn(&imgu->pci_dev->dev, "dma buf resized from %zu to %zu",
                         map->size, size);

                imgu_dmamap_free(imgu, map);
                if (!imgu_dmamap_alloc(imgu, map, size))
                        return -ENOMEM;
        }

        return 0;
}

void imgu_css_pool_cleanup(struct imgu_device *imgu, struct imgu_css_pool *pool)
{
        unsigned int i;

        for (i = 0; i < IPU3_CSS_POOL_SIZE; i++)
                imgu_dmamap_free(imgu, &pool->entry[i].param);
}

int imgu_css_pool_init(struct imgu_device *imgu, struct imgu_css_pool *pool,
                       size_t size)
{
        unsigned int i;

        for (i = 0; i < IPU3_CSS_POOL_SIZE; i++) {
                pool->entry[i].valid = false;
                if (size == 0) {
                        pool->entry[i].param.vaddr = NULL;
                        continue;
                }

                if (!imgu_dmamap_alloc(imgu, &pool->entry[i].param, size))
                        goto fail;
        }

        pool->last = IPU3_CSS_POOL_SIZE;

        return 0;

fail:
        imgu_css_pool_cleanup(imgu, pool);
        return -ENOMEM;
}

/*
 * Allocate a new parameter via recycling the oldest entry in the pool.
 */
void imgu_css_pool_get(struct imgu_css_pool *pool)
{
        /* Get the oldest entry */
        u32 n = (pool->last + 1) % IPU3_CSS_POOL_SIZE;

        pool->entry[n].valid = true;
        pool->last = n;
}

/*
 * Undo, for all practical purposes, the effect of pool_get().
 */
void imgu_css_pool_put(struct imgu_css_pool *pool)
{
        pool->entry[pool->last].valid = false;
        pool->last = (pool->last + IPU3_CSS_POOL_SIZE - 1) % IPU3_CSS_POOL_SIZE;
}

/**
 * imgu_css_pool_last - Retrieve the nth pool entry from last
 *
 * @pool: a pointer to &struct imgu_css_pool.
 * @n: the distance to the last index.
 *
 * Returns:
 *  The nth entry from last or null map to indicate no frame stored.
 */
const struct imgu_css_map *
imgu_css_pool_last(struct imgu_css_pool *pool, unsigned int n)
{
        static const struct imgu_css_map null_map = { 0 };
        int i = (pool->last + IPU3_CSS_POOL_SIZE - n) % IPU3_CSS_POOL_SIZE;

        WARN_ON(n >= IPU3_CSS_POOL_SIZE);

        if (!pool->entry[i].valid)
                return &null_map;

        return &pool->entry[i].param;
}