102 lines
2.6 KiB
C
102 lines
2.6 KiB
C
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/* net/atm/atm_misc.c - Various functions for use by ATM drivers */
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/* Written 1995-2000 by Werner Almesberger, EPFL ICA */
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#include <linux/module.h>
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#include <linux/atm.h>
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#include <linux/atmdev.h>
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#include <linux/skbuff.h>
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#include <linux/sonet.h>
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#include <linux/bitops.h>
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#include <linux/errno.h>
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#include <linux/atomic.h>
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int atm_charge(struct atm_vcc *vcc, int truesize)
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{
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atm_force_charge(vcc, truesize);
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if (atomic_read(&sk_atm(vcc)->sk_rmem_alloc) <= sk_atm(vcc)->sk_rcvbuf)
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return 1;
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atm_return(vcc, truesize);
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atomic_inc(&vcc->stats->rx_drop);
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return 0;
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}
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EXPORT_SYMBOL(atm_charge);
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struct sk_buff *atm_alloc_charge(struct atm_vcc *vcc, int pdu_size,
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gfp_t gfp_flags)
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{
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struct sock *sk = sk_atm(vcc);
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int guess = SKB_TRUESIZE(pdu_size);
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atm_force_charge(vcc, guess);
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if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) {
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struct sk_buff *skb = alloc_skb(pdu_size, gfp_flags);
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if (skb) {
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atomic_add(skb->truesize-guess,
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&sk->sk_rmem_alloc);
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return skb;
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}
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}
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atm_return(vcc, guess);
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atomic_inc(&vcc->stats->rx_drop);
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return NULL;
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}
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EXPORT_SYMBOL(atm_alloc_charge);
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/*
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* atm_pcr_goal returns the positive PCR if it should be rounded up, the
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* negative PCR if it should be rounded down, and zero if the maximum available
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* bandwidth should be used.
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*
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* The rules are as follows (* = maximum, - = absent (0), x = value "x",
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* (x+ = x or next value above x, x- = x or next value below):
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*
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* min max pcr result min max pcr result
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* - - - * (UBR only) x - - x+
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* - - * * x - * *
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* - - z z- x - z z-
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* - * - * x * - x+
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* - * * * x * * *
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* - * z z- x * z z-
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* - y - y- x y - x+
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* - y * y- x y * y-
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* - y z z- x y z z-
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*
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* All non-error cases can be converted with the following simple set of rules:
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*
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* if pcr == z then z-
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* else if min == x && pcr == - then x+
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* else if max == y then y-
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* else *
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*/
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int atm_pcr_goal(const struct atm_trafprm *tp)
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{
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if (tp->pcr && tp->pcr != ATM_MAX_PCR)
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return -tp->pcr;
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if (tp->min_pcr && !tp->pcr)
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return tp->min_pcr;
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if (tp->max_pcr != ATM_MAX_PCR)
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return -tp->max_pcr;
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return 0;
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}
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EXPORT_SYMBOL(atm_pcr_goal);
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void sonet_copy_stats(struct k_sonet_stats *from, struct sonet_stats *to)
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{
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#define __HANDLE_ITEM(i) to->i = atomic_read(&from->i)
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__SONET_ITEMS
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#undef __HANDLE_ITEM
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}
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EXPORT_SYMBOL(sonet_copy_stats);
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void sonet_subtract_stats(struct k_sonet_stats *from, struct sonet_stats *to)
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{
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#define __HANDLE_ITEM(i) atomic_sub(to->i, &from->i)
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__SONET_ITEMS
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#undef __HANDLE_ITEM
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}
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EXPORT_SYMBOL(sonet_subtract_stats);
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