Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/* 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 <asm/atomic.h>

#include <asm/errno.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;

}

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 = atm_guess_pdu2truesize(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;

}

/*

 * 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-

 *      -   y   -       y-              x   y   -       x+

 *      -   y   *       y-              x   y   *       y-

 *      -   y   z       z-              x   y   z       z-

 *

 * All non-error cases can be converted with the following simple set of rules:

 *

 *   if pcr == z then z-

 *   else if min == x && pcr == - then x+

 *     else if max == y then y-

 *       else *

 */

int atm_pcr_goal(const struct atm_trafprm *tp)

{

        if (tp->pcr && tp->pcr != ATM_MAX_PCR)

                return -tp->pcr;

        if (tp->min_pcr && !tp->pcr)

                return tp->min_pcr;

        if (tp->max_pcr != ATM_MAX_PCR)

                return -tp->max_pcr;

        return 0;

}

void sonet_copy_stats(struct k_sonet_stats *from,struct sonet_stats *to)

{

#define __HANDLE_ITEM(i) to->i = atomic_read(&from->i)

        __SONET_ITEMS

#undef __HANDLE_ITEM

}

void sonet_subtract_stats(struct k_sonet_stats *from,struct sonet_stats *to)

{

#define __HANDLE_ITEM(i) atomic_sub(to->i,&from->i)

        __SONET_ITEMS

#undef __HANDLE_ITEM

}

EXPORT_SYMBOL(atm_charge);

EXPORT_SYMBOL(atm_alloc_charge);

EXPORT_SYMBOL(atm_pcr_goal);

EXPORT_SYMBOL(sonet_copy_stats);

EXPORT_SYMBOL(sonet_subtract_stats);