blob: 876fbe83e2e4db5ded907ea9938c435edc059e0c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* net/atm/atm_misc.c - Various functions for use by ATM drivers */
2
3/* Written 1995-2000 by Werner Almesberger, EPFL ICA */
4
Linus Torvalds1da177e2005-04-16 15:20:36 -07005#include <linux/module.h>
6#include <linux/atm.h>
7#include <linux/atmdev.h>
8#include <linux/skbuff.h>
9#include <linux/sonet.h>
10#include <linux/bitops.h>
Joe Perches3356b4d2010-01-26 11:40:02 +000011#include <linux/errno.h>
Arun Sharma60063492011-07-26 16:09:06 -070012#include <linux/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013
Joe Perches3356b4d2010-01-26 11:40:02 +000014int atm_charge(struct atm_vcc *vcc, int truesize)
Linus Torvalds1da177e2005-04-16 15:20:36 -070015{
Joe Perches3356b4d2010-01-26 11:40:02 +000016 atm_force_charge(vcc, truesize);
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 if (atomic_read(&sk_atm(vcc)->sk_rmem_alloc) <= sk_atm(vcc)->sk_rcvbuf)
18 return 1;
Joe Perches3356b4d2010-01-26 11:40:02 +000019 atm_return(vcc, truesize);
Linus Torvalds1da177e2005-04-16 15:20:36 -070020 atomic_inc(&vcc->stats->rx_drop);
21 return 0;
22}
Joe Perches3356b4d2010-01-26 11:40:02 +000023EXPORT_SYMBOL(atm_charge);
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
Joe Perches3356b4d2010-01-26 11:40:02 +000025struct sk_buff *atm_alloc_charge(struct atm_vcc *vcc, int pdu_size,
26 gfp_t gfp_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -070027{
28 struct sock *sk = sk_atm(vcc);
chas williams - CONTRACTOR49f5ed42011-11-22 12:51:56 +000029 int guess = SKB_TRUESIZE(pdu_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
Joe Perches3356b4d2010-01-26 11:40:02 +000031 atm_force_charge(vcc, guess);
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) {
Joe Perches3356b4d2010-01-26 11:40:02 +000033 struct sk_buff *skb = alloc_skb(pdu_size, gfp_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35 if (skb) {
36 atomic_add(skb->truesize-guess,
37 &sk->sk_rmem_alloc);
38 return skb;
39 }
40 }
Joe Perches3356b4d2010-01-26 11:40:02 +000041 atm_return(vcc, guess);
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 atomic_inc(&vcc->stats->rx_drop);
43 return NULL;
44}
Joe Perches3356b4d2010-01-26 11:40:02 +000045EXPORT_SYMBOL(atm_alloc_charge);
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
47
48/*
49 * atm_pcr_goal returns the positive PCR if it should be rounded up, the
50 * negative PCR if it should be rounded down, and zero if the maximum available
51 * bandwidth should be used.
52 *
53 * The rules are as follows (* = maximum, - = absent (0), x = value "x",
54 * (x+ = x or next value above x, x- = x or next value below):
55 *
56 * min max pcr result min max pcr result
57 * - - - * (UBR only) x - - x+
58 * - - * * x - * *
59 * - - z z- x - z z-
60 * - * - * x * - x+
61 * - * * * x * * *
62 * - * z z- x * z z-
63 * - y - y- x y - x+
64 * - y * y- x y * y-
65 * - y z z- x y z z-
66 *
67 * All non-error cases can be converted with the following simple set of rules:
68 *
69 * if pcr == z then z-
70 * else if min == x && pcr == - then x+
71 * else if max == y then y-
72 * else *
73 */
74
Mitchell Blank Jrc2197502005-11-29 16:13:55 -080075int atm_pcr_goal(const struct atm_trafprm *tp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070076{
Mitchell Blank Jrc2197502005-11-29 16:13:55 -080077 if (tp->pcr && tp->pcr != ATM_MAX_PCR)
78 return -tp->pcr;
79 if (tp->min_pcr && !tp->pcr)
80 return tp->min_pcr;
81 if (tp->max_pcr != ATM_MAX_PCR)
82 return -tp->max_pcr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 return 0;
84}
Joe Perches3356b4d2010-01-26 11:40:02 +000085EXPORT_SYMBOL(atm_pcr_goal);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
Joe Perches3356b4d2010-01-26 11:40:02 +000087void sonet_copy_stats(struct k_sonet_stats *from, struct sonet_stats *to)
Linus Torvalds1da177e2005-04-16 15:20:36 -070088{
89#define __HANDLE_ITEM(i) to->i = atomic_read(&from->i)
90 __SONET_ITEMS
91#undef __HANDLE_ITEM
92}
Joe Perches3356b4d2010-01-26 11:40:02 +000093EXPORT_SYMBOL(sonet_copy_stats);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094
Joe Perches3356b4d2010-01-26 11:40:02 +000095void sonet_subtract_stats(struct k_sonet_stats *from, struct sonet_stats *to)
Linus Torvalds1da177e2005-04-16 15:20:36 -070096{
Joe Perches3356b4d2010-01-26 11:40:02 +000097#define __HANDLE_ITEM(i) atomic_sub(to->i, &from->i)
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 __SONET_ITEMS
99#undef __HANDLE_ITEM
100}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101EXPORT_SYMBOL(sonet_subtract_stats);