1 /* net/atm/atm_misc.c - Various functions for use by ATM drivers */
3 /* Written 1995-2000 by Werner Almesberger, EPFL ICA */
6 #include <linux/module.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>
16 int atm_charge(struct atm_vcc
*vcc
,int truesize
)
18 atm_force_charge(vcc
,truesize
);
19 if (atomic_read(&vcc
->sk
->sk_rmem_alloc
) <= vcc
->sk
->sk_rcvbuf
)
21 atm_return(vcc
,truesize
);
22 atomic_inc(&vcc
->stats
->rx_drop
);
27 struct sk_buff
*atm_alloc_charge(struct atm_vcc
*vcc
,int pdu_size
,
30 int guess
= atm_guess_pdu2truesize(pdu_size
);
32 atm_force_charge(vcc
,guess
);
33 if (atomic_read(&vcc
->sk
->sk_rmem_alloc
) <= vcc
->sk
->sk_rcvbuf
) {
34 struct sk_buff
*skb
= alloc_skb(pdu_size
,gfp_flags
);
37 atomic_add(skb
->truesize
-guess
,
38 &vcc
->sk
->sk_rmem_alloc
);
42 atm_return(vcc
,guess
);
43 atomic_inc(&vcc
->stats
->rx_drop
);
48 static int check_ci(struct atm_vcc
*vcc
,short vpi
,int vci
)
50 struct hlist_node
*node
;
54 sk_for_each(s
, node
, &vcc_sklist
) {
56 if (walk
->dev
!= vcc
->dev
)
58 if (test_bit(ATM_VF_ADDR
,&walk
->flags
) && walk
->vpi
== vpi
&&
59 walk
->vci
== vci
&& ((walk
->qos
.txtp
.traffic_class
!=
60 ATM_NONE
&& vcc
->qos
.txtp
.traffic_class
!= ATM_NONE
) ||
61 (walk
->qos
.rxtp
.traffic_class
!= ATM_NONE
&&
62 vcc
->qos
.rxtp
.traffic_class
!= ATM_NONE
)))
65 /* allow VCCs with same VPI/VCI iff they don't collide on
66 TX/RX (but we may refuse such sharing for other reasons,
67 e.g. if protocol requires to have both channels) */
72 int atm_find_ci(struct atm_vcc
*vcc
,short *vpi
,int *vci
)
74 static short p
= 0; /* poor man's per-device cache */
80 read_lock(&vcc_sklist_lock
);
81 if (*vpi
!= ATM_VPI_ANY
&& *vci
!= ATM_VCI_ANY
) {
82 err
= check_ci(vcc
,*vpi
,*vci
);
83 read_unlock(&vcc_sklist_lock
);
86 /* last scan may have left values out of bounds for current device */
87 if (*vpi
!= ATM_VPI_ANY
) p
= *vpi
;
88 else if (p
>= 1 << vcc
->dev
->ci_range
.vpi_bits
) p
= 0;
89 if (*vci
!= ATM_VCI_ANY
) c
= *vci
;
90 else if (c
< ATM_NOT_RSV_VCI
|| c
>= 1 << vcc
->dev
->ci_range
.vci_bits
)
95 if (!check_ci(vcc
,p
,c
)) {
98 read_unlock(&vcc_sklist_lock
);
101 if (*vci
== ATM_VCI_ANY
) {
103 if (c
>= 1 << vcc
->dev
->ci_range
.vci_bits
)
106 if ((c
== ATM_NOT_RSV_VCI
|| *vci
!= ATM_VCI_ANY
) &&
107 *vpi
== ATM_VPI_ANY
) {
109 if (p
>= 1 << vcc
->dev
->ci_range
.vpi_bits
) p
= 0;
112 while (old_p
!= p
|| old_c
!= c
);
113 read_unlock(&vcc_sklist_lock
);
119 * atm_pcr_goal returns the positive PCR if it should be rounded up, the
120 * negative PCR if it should be rounded down, and zero if the maximum available
121 * bandwidth should be used.
123 * The rules are as follows (* = maximum, - = absent (0), x = value "x",
124 * (x+ = x or next value above x, x- = x or next value below):
126 * min max pcr result min max pcr result
127 * - - - * (UBR only) x - - x+
137 * All non-error cases can be converted with the following simple set of rules:
139 * if pcr == z then z-
140 * else if min == x && pcr == - then x+
141 * else if max == y then y-
146 int atm_pcr_goal(struct atm_trafprm
*tp
)
148 if (tp
->pcr
&& tp
->pcr
!= ATM_MAX_PCR
) return -tp
->pcr
;
149 if (tp
->min_pcr
&& !tp
->pcr
) return tp
->min_pcr
;
150 if (tp
->max_pcr
!= ATM_MAX_PCR
) return -tp
->max_pcr
;
155 void sonet_copy_stats(struct k_sonet_stats
*from
,struct sonet_stats
*to
)
157 #define __HANDLE_ITEM(i) to->i = atomic_read(&from->i)
163 void sonet_subtract_stats(struct k_sonet_stats
*from
,struct sonet_stats
*to
)
165 #define __HANDLE_ITEM(i) atomic_sub(to->i,&from->i)
171 EXPORT_SYMBOL(atm_charge
);
172 EXPORT_SYMBOL(atm_alloc_charge
);
173 EXPORT_SYMBOL(atm_find_ci
);
174 EXPORT_SYMBOL(atm_pcr_goal
);
175 EXPORT_SYMBOL(sonet_copy_stats
);
176 EXPORT_SYMBOL(sonet_subtract_stats
);