linux-imx

// SPDX-License-Identifier: GPL-2.0

/* net/atm/atm_misc.c - Various functions for use by ATM drivers */

​

/* Written 1995-2000 by Werner Almesberger, EPFL ICA */

​

#include <linux/module.h>

#include <linux/atm.h>

#include <linux/atmdev.h>

#include <linux/skbuff.h>

#include <linux/sonet.h>

#include <linux/bitops.h>

#include <linux/errno.h>

#include <linux/atomic.h>

​

int atm_charge(struct atm_vcc *vcc, int truesize)

{

    atm_force_charge(vcc, truesize);

    if (atomic_read(&sk_atm(vcc)->sk_rmem_alloc) <= sk_atm(vcc)->sk_rcvbuf)

        return 1;

    atm_return(vcc, truesize);

    atomic_inc(&vcc->stats->rx_drop);

    return 0;

}

EXPORT_SYMBOL(atm_charge);

​

struct sk_buff *atm_alloc_charge(struct atm_vcc *vcc, int pdu_size,

                 gfp_t gfp_flags)

{

    struct sock *sk = sk_atm(vcc);

    int guess = SKB_TRUESIZE(pdu_size);

​

    atm_force_charge(vcc, guess);

    if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) {

        struct sk_buff *skb = alloc_skb(pdu_size, gfp_flags);

​

        if (skb) {

            atomic_add(skb->truesize-guess,

                   &sk->sk_rmem_alloc);

            return skb;

        }

    }

    atm_return(vcc, guess);

    atomic_inc(&vcc->stats->rx_drop);

    return NULL;

}

EXPORT_SYMBOL(atm_alloc_charge);

​

​

/*

 * atm_pcr_goal returns the positive PCR if it should be rounded up, the

 * negative PCR if it should be rounded down, and zero if the maximum available

 * bandwidth should be used.

 *

 * The rules are as follows (* = maximum, - = absent (0), x = value "x",

 * (x+ = x or next value above x, x- = x or next value below):

 *

 *  min max pcr result      min max pcr result

 *  -   -   -   * (UBR only)    x   -   -   x+

 *  -   -   *   *       x   -   *   *

 *  -   -   z   z-      x   -   z   z-

 *  -   *   -   *       x   *   -   x+

 *  -   *   *   *       x   *   *   *

 *  -   *   z   z-      x   *   z   z-