// SPDX-License-Identifier: MIT
/*
 * Copyright 2019 Advanced Micro Devices, Inc.
 */

#include <linux/slab.h>
#include <linux/tee_core.h>
#include <linux/psp.h>
#include "amdtee_private.h"

static int pool_op_alloc(struct tee_shm_pool *pool, struct tee_shm *shm,
                         size_t size, size_t align)
{
        unsigned int order = get_order(size);
        unsigned long va;
        int rc;

        /*
         * Ignore alignment since this is already going to be page aligned
         * and there's no need for any larger alignment.
         */
        va = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
        if (!va)
                return -ENOMEM;

        shm->kaddr = (void *)va;
        shm->paddr = __psp_pa((void *)va);
        shm->size = PAGE_SIZE << order;

        /* Map the allocated memory in to TEE */
        rc = amdtee_map_shmem(shm);
        if (rc) {
                free_pages(va, order);
                shm->kaddr = NULL;
                return rc;
        }

        return 0;
}

static void pool_op_free(struct tee_shm_pool *pool, struct tee_shm *shm)
{
        /* Unmap the shared memory from TEE */
        amdtee_unmap_shmem(shm);
        free_pages((unsigned long)shm->kaddr, get_order(shm->size));
        shm->kaddr = NULL;
}

static void pool_op_destroy_pool(struct tee_shm_pool *pool)
{
        kfree(pool);
}

static const struct tee_shm_pool_ops pool_ops = {
        .alloc = pool_op_alloc,
        .free = pool_op_free,
        .destroy_pool = pool_op_destroy_pool,
};

struct tee_shm_pool *amdtee_config_shm(void)
{
        struct tee_shm_pool *pool = kzalloc_obj(*pool);

        if (!pool)
                return ERR_PTR(-ENOMEM);

        pool->ops = &pool_ops;

        return pool;
}