zhpe_pasid.c

/*
 * Copyright (C) 2018 Hewlett Packard Enterprise Development LP.
 * All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * BSD license below:
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <linux/kernel.h>
#include <linux/idr.h>
#include "zhpe.h"
#include "zhpe_driver.h"

static struct ida zhpe_pasid_ida;

void zhpe_pasid_init(void)
{
    ida_init(&zhpe_pasid_ida);
}

void zhpe_pasid_exit(void)
{
    ida_destroy(&zhpe_pasid_ida);
}

int zhpe_pasid_alloc(unsigned int *pasid)
{
    int ret;

    /* this function does memory allocation, and might sleep */
    ret = ida_simple_get(&zhpe_pasid_ida, 1, ZHPE_NUM_PASIDS, GFP_KERNEL);
    if (ret < 0)
        return ret;

    *pasid = (unsigned int)ret;
    return 0;
}

void zhpe_pasid_free(unsigned int pasid)
{
    ida_simple_remove(&zhpe_pasid_ida, pasid);
}