linux-imx

/*

 * net/core/netprio_cgroup.c    Priority Control Group

 *

 *      This program is free software; you can redistribute it and/or

 *      modify it under the terms of the GNU General Public License

 *      as published by the Free Software Foundation; either version

 *      2 of the License, or (at your option) any later version.

 *

 * Authors: Neil Horman <nhorman@tuxdriver.com>

 */

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/types.h>

#include <linux/string.h>

#include <linux/errno.h>

#include <linux/skbuff.h>

#include <linux/cgroup.h>

#include <linux/rcupdate.h>

#include <linux/atomic.h>

#include <linux/sched/task.h>

​

#include <net/rtnetlink.h>

#include <net/pkt_cls.h>

#include <net/sock.h>

#include <net/netprio_cgroup.h>

​

#include <linux/fdtable.h>

​

/*

 * netprio allocates per-net_device priomap array which is indexed by

 * css->id.  Limiting css ID to 16bits doesn't lose anything.

 */

#define NETPRIO_ID_MAX      USHRT_MAX

​

#define PRIOMAP_MIN_SZ      128

​

/*

 * Extend @dev->priomap so that it's large enough to accommodate

 * @target_idx.  @dev->priomap.priomap_len > @target_idx after successful

 * return.  Must be called under rtnl lock.

 */

static int extend_netdev_table(struct net_device *dev, u32 target_idx)

{

    struct netprio_map *old, *new;

    size_t new_sz, new_len;

​

    /* is the existing priomap large enough? */

    old = rtnl_dereference(dev->priomap);

    if (old && old->priomap_len > target_idx)

        return 0;

​

    /*

     * Determine the new size.  Let's keep it power-of-two.  We start

     * from PRIOMAP_MIN_SZ and double it until it's large enough to

     * accommodate @target_idx.

     */

    new_sz = PRIOMAP_MIN_SZ;

    while (true) {

        new_len = (new_sz - offsetof(struct netprio_map, priomap)) /

            sizeof(new->priomap[0]);