/* 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(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);