diff options
Diffstat (limited to 'net/atm/atm_misc.c')
-rw-r--r-- | net/atm/atm_misc.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/net/atm/atm_misc.c b/net/atm/atm_misc.c new file mode 100644 index 0000000000..a30b83c1cb --- /dev/null +++ b/net/atm/atm_misc.c @@ -0,0 +1,102 @@ +// 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- + * - 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; +} +EXPORT_SYMBOL(atm_pcr_goal); + +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 +} +EXPORT_SYMBOL(sonet_copy_stats); + +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(sonet_subtract_stats); |