// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015, 2017, 2022 Linaro Limited
 */
#include <linux/device.h>
#include <linux/dma-buf.h>
#include <linux/genalloc.h>
#include <linux/slab.h>
#include <linux/tee_core.h>
#include "tee_private.h"

static int pool_op_gen_alloc(struct tee_shm_pool *pool, struct tee_shm *shm,
                             size_t size, size_t align)
{
        unsigned long va;
        struct gen_pool *genpool = pool->private_data;
        size_t a = max_t(size_t, align, BIT(genpool->min_alloc_order));
        struct genpool_data_align data = { .align = a };
        size_t s = roundup(size, a);

        va = gen_pool_alloc_algo(genpool, s, gen_pool_first_fit_align, &data);
        if (!va)
                return -ENOMEM;

        memset((void *)va, 0, s);
        shm->kaddr = (void *)va;
        shm->paddr = gen_pool_virt_to_phys(genpool, va);
        shm->size = s;
        /*
         * This is from a static shared memory pool so no need to register
         * each chunk, and no need to unregister later either.
         */
        shm->flags &= ~TEE_SHM_DYNAMIC;
        return 0;
}

static void pool_op_gen_free(struct tee_shm_pool *pool, struct tee_shm *shm)
{
        gen_pool_free(pool->private_data, (unsigned long)shm->kaddr,
                      shm->size);
        shm->kaddr = NULL;
}

static void pool_op_gen_destroy_pool(struct tee_shm_pool *pool)
{
        gen_pool_destroy(pool->private_data);
        kfree(pool);
}

static const struct tee_shm_pool_ops pool_ops_generic = {
        .alloc = pool_op_gen_alloc,
        .free = pool_op_gen_free,
        .destroy_pool = pool_op_gen_destroy_pool,
};

struct tee_shm_pool *tee_shm_pool_alloc_res_mem(unsigned long vaddr,
                                                phys_addr_t paddr, size_t size,
                                                int min_alloc_order)
{
        const size_t page_mask = PAGE_SIZE - 1;
        struct tee_shm_pool *pool;
        int rc;

        /* Start and end must be page aligned */
        if (vaddr & page_mask || paddr & page_mask || size & page_mask)
                return ERR_PTR(-EINVAL);

        pool = kzalloc_obj(*pool);
        if (!pool)
                return ERR_PTR(-ENOMEM);

        pool->private_data = gen_pool_create(min_alloc_order, -1);
        if (!pool->private_data) {
                rc = -ENOMEM;
                goto err;
        }

        rc = gen_pool_add_virt(pool->private_data, vaddr, paddr, size, -1);
        if (rc) {
                gen_pool_destroy(pool->private_data);
                goto err;
        }

        pool->ops = &pool_ops_generic;

        return pool;
err:
        kfree(pool);

        return ERR_PTR(rc);
}
EXPORT_SYMBOL_GPL(tee_shm_pool_alloc_res_mem);