1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* net/atm/atm_misc.c - Various functions for use by ATM drivers */ |
3 | |
4 | /* Written 1995-2000 by Werner Almesberger, EPFL ICA */ |
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 <linux/errno.h> |
13 | #include <linux/atomic.h> |
14 | |
15 | int atm_charge(struct atm_vcc *vcc, int truesize) |
16 | { |
17 | atm_force_charge(vcc, truesize); |
18 | if (atomic_read(v: &sk_atm(vcc)->sk_rmem_alloc) <= sk_atm(vcc)->sk_rcvbuf) |
19 | return 1; |
20 | atm_return(vcc, truesize); |
21 | atomic_inc(v: &vcc->stats->rx_drop); |
22 | return 0; |
23 | } |
24 | EXPORT_SYMBOL(atm_charge); |
25 | |
26 | struct sk_buff *atm_alloc_charge(struct atm_vcc *vcc, int pdu_size, |
27 | gfp_t gfp_flags) |
28 | { |
29 | struct sock *sk = sk_atm(vcc); |
30 | int guess = SKB_TRUESIZE(pdu_size); |
31 | |
32 | atm_force_charge(vcc, truesize: guess); |
33 | if (atomic_read(v: &sk->sk_rmem_alloc) <= sk->sk_rcvbuf) { |
34 | struct sk_buff *skb = alloc_skb(size: pdu_size, priority: gfp_flags); |
35 | |
36 | if (skb) { |
37 | atomic_add(i: skb->truesize-guess, |
38 | v: &sk->sk_rmem_alloc); |
39 | return skb; |
40 | } |
41 | } |
42 | atm_return(vcc, truesize: guess); |
43 | atomic_inc(v: &vcc->stats->rx_drop); |
44 | return NULL; |
45 | } |
46 | EXPORT_SYMBOL(atm_alloc_charge); |
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 | int atm_pcr_goal(const struct atm_trafprm *tp) |
77 | { |
78 | if (tp->pcr && tp->pcr != ATM_MAX_PCR) |
79 | return -tp->pcr; |
80 | if (tp->min_pcr && !tp->pcr) |
81 | return tp->min_pcr; |
82 | if (tp->max_pcr != ATM_MAX_PCR) |
83 | return -tp->max_pcr; |
84 | return 0; |
85 | } |
86 | EXPORT_SYMBOL(atm_pcr_goal); |
87 | |
88 | void sonet_copy_stats(struct k_sonet_stats *from, struct sonet_stats *to) |
89 | { |
90 | #define __HANDLE_ITEM(i) to->i = atomic_read(&from->i) |
91 | __SONET_ITEMS |
92 | #undef __HANDLE_ITEM |
93 | } |
94 | EXPORT_SYMBOL(sonet_copy_stats); |
95 | |
96 | void sonet_subtract_stats(struct k_sonet_stats *from, struct sonet_stats *to) |
97 | { |
98 | #define __HANDLE_ITEM(i) atomic_sub(to->i, &from->i) |
99 | __SONET_ITEMS |
100 | #undef __HANDLE_ITEM |
101 | } |
102 | EXPORT_SYMBOL(sonet_subtract_stats); |
103 | |