net/atm/atm_misc.c

Source file repositories/reference/linux-study-clean/net/atm/atm_misc.c

File Facts

System
Linux kernel
Corpus path
net/atm/atm_misc.c
Extension
.c
Size
2671 bytes
Lines
103
Domain
Networking Core
Bucket
Sockets, Protocols, Packet Path, And Network Policy
Inferred role
Networking Core: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.

Dependency Surface

Detected Declarations

Annotated Snippet

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);

Annotation

Implementation Notes