projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* net/atm/atm_misc.c - Various functions for use by ATM drivers */ |
| 2 | ||
| 3 | /* Written 1995-2000 by Werner Almesberger, EPFL ICA */ | |
| 4 | ||
| 5 | ||
| 6 | #include <linux/module.h> | |
| 7 | #include <linux/atm.h> | |
| 8 | #include <linux/atmdev.h> | |
| 9 | #include <linux/skbuff.h> | |
| 10 | #include <linux/sonet.h> | |
| 11 | #include <linux/bitops.h> | |
| 12 | #include <asm/atomic.h> | |
| 13 | #include <asm/errno.h> | |
| 14 | ||
| 15 | ||
| 16 | int atm_charge(struct atm_vcc *vcc,int truesize) | |
| 17 | { | |
| 18 | atm_force_charge(vcc,truesize); | |
| 19 | if (atomic_read(&sk_atm(vcc)->sk_rmem_alloc) <= sk_atm(vcc)->sk_rcvbuf) | |
| 20 | return 1; | |
| 21 | atm_return(vcc,truesize); | |
| 22 | atomic_inc(&vcc->stats->rx_drop); | |
| 23 | return 0; | |
| 24 | } | |
| 25 | ||
| 26 | ||
| 27 | struct sk_buff *atm_alloc_charge(struct atm_vcc *vcc,int pdu_size, | |
| dd0fc66f | 28 | gfp_t gfp_flags) |
| 1da177e4 LT |
29 | { |
| 30 | struct sock *sk = sk_atm(vcc); | |
| 31 | int guess = atm_guess_pdu2truesize(pdu_size); | |
| 32 | ||
| 33 | atm_force_charge(vcc,guess); | |
| 34 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) { | |
| 35 | struct sk_buff *skb = alloc_skb(pdu_size,gfp_flags); | |
| 36 | ||
| 37 | if (skb) { | |
| 38 | atomic_add(skb->truesize-guess, | |
| 39 | &sk->sk_rmem_alloc); | |
| 40 | return skb; | |
| 41 | } | |
| 42 | } | |
| 43 | atm_return(vcc,guess); | |
| 44 | atomic_inc(&vcc->stats->rx_drop); | |
| 45 | return NULL; | |
| 46 | } | |
| 47 | ||
| 48 | ||
| 49 | /* | |
| 50 | * atm_pcr_goal returns the positive PCR if it should be rounded up, the | |
| 51 | * negative PCR if it should be rounded down, and zero if the maximum available | |
| 52 | * bandwidth should be used. | |
| 53 | * | |
| 54 | * The rules are as follows (* = maximum, - = absent (0), x = value "x", | |
| 55 | * (x+ = x or next value above x, x- = x or next value below): | |
| 56 | * | |
| 57 | * min max pcr result min max pcr result | |
| 58 | * - - - * (UBR only) x - - x+ | |
| 59 | * - - * * x - * * | |
| 60 | * - - z z- x - z z- | |
| 61 | * - * - * x * - x+ | |
| 62 | * - * * * x * * * | |
| 63 | * - * z z- x * z z- | |
| 64 | * - y - y- x y - x+ | |
| 65 | * - y * y- x y * y- | |
| 66 | * - y z z- x y z z- | |
| 67 | * | |
| 68 | * All non-error cases can be converted with the following simple set of rules: | |
| 69 | * | |
| 70 | * if pcr == z then z- | |
| 71 | * else if min == x && pcr == - then x+ | |
| 72 | * else if max == y then y- | |
| 73 | * else * | |
| 74 | */ | |
| 75 | ||
| 76 | ||
| c219750b | 77 | int atm_pcr_goal(const struct atm_trafprm *tp) |
| 1da177e4 | 78 | { |
| c219750b MBJ |
79 | if (tp->pcr && tp->pcr != ATM_MAX_PCR) |
| 80 | return -tp->pcr; | |
| 81 | if (tp->min_pcr && !tp->pcr) | |
| 82 | return tp->min_pcr; | |
| 83 | if (tp->max_pcr != ATM_MAX_PCR) | |
| 84 | return -tp->max_pcr; | |
| 1da177e4 LT |
85 | return 0; |
| 86 | } | |
| 87 | ||
| 88 | ||
| 89 | void sonet_copy_stats(struct k_sonet_stats *from,struct sonet_stats *to) | |
| 90 | { | |
| 91 | #define __HANDLE_ITEM(i) to->i = atomic_read(&from->i) | |
| 92 | __SONET_ITEMS | |
| 93 | #undef __HANDLE_ITEM | |
| 94 | } | |
| 95 | ||
| 96 | ||
| 97 | void sonet_subtract_stats(struct k_sonet_stats *from,struct sonet_stats *to) | |
| 98 | { | |
| 99 | #define __HANDLE_ITEM(i) atomic_sub(to->i,&from->i) | |
| 100 | __SONET_ITEMS | |
| 101 | #undef __HANDLE_ITEM | |
| 102 | } | |
| 103 | ||
| 104 | ||
| 105 | EXPORT_SYMBOL(atm_charge); | |
| 106 | EXPORT_SYMBOL(atm_alloc_charge); | |
| 107 | EXPORT_SYMBOL(atm_pcr_goal); | |
| 108 | EXPORT_SYMBOL(sonet_copy_stats); | |
| 109 | EXPORT_SYMBOL(sonet_subtract_stats); |