udp: move scratch area helpers into the include file

So that they can be later used by the IPv6 code, too.
Also lift the comments a bit.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Paolo Abeni 2017-06-26 19:01:50 +02:00 committed by David S. Miller
parent d97af30f61
commit b26bbdae46
2 changed files with 61 additions and 60 deletions

View File

@ -302,6 +302,67 @@ struct sock *__udp6_lib_lookup(struct net *net,
struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
__be16 sport, __be16 dport);
/* UDP uses skb->dev_scratch to cache as much information as possible and avoid
* possibly multiple cache miss on dequeue()
*/
#if BITS_PER_LONG == 64
/* truesize, len and the bit needed to compute skb_csum_unnecessary will be on
* cold cache lines at recvmsg time.
* skb->len can be stored on 16 bits since the udp header has been already
* validated and pulled.
*/
struct udp_dev_scratch {
u32 truesize;
u16 len;
bool is_linear;
bool csum_unnecessary;
};
static inline unsigned int udp_skb_len(struct sk_buff *skb)
{
return ((struct udp_dev_scratch *)&skb->dev_scratch)->len;
}
static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb)
{
return ((struct udp_dev_scratch *)&skb->dev_scratch)->csum_unnecessary;
}
static inline bool udp_skb_is_linear(struct sk_buff *skb)
{
return ((struct udp_dev_scratch *)&skb->dev_scratch)->is_linear;
}
#else
static inline unsigned int udp_skb_len(struct sk_buff *skb)
{
return skb->len;
}
static inline bool udp_skb_csum_unnecessary(struct sk_buff *skb)
{
return skb_csum_unnecessary(skb);
}
static inline bool udp_skb_is_linear(struct sk_buff *skb)
{
return !skb_is_nonlinear(skb);
}
#endif
static inline int copy_linear_skb(struct sk_buff *skb, int len, int off,
struct iov_iter *to)
{
int n, copy = len - off;
n = copy_to_iter(skb->data + off, copy, to);
if (n == copy)
return 0;
return -EFAULT;
}
/*
* SNMP statistics for UDP and UDP-Lite
*/

View File

@ -1163,24 +1163,7 @@ out:
return ret;
}
/* Copy as much information as possible into skb->dev_scratch to avoid
* possibly multiple cache miss on dequeue();
*/
#if BITS_PER_LONG == 64
/* we can store multiple info here: truesize, len and the bit needed to
* compute skb_csum_unnecessary will be on cold cache lines at recvmsg
* time.
* skb->len can be stored on 16 bits since the udp header has been already
* validated and pulled.
*/
struct udp_dev_scratch {
u32 truesize;
u16 len;
bool is_linear;
bool csum_unnecessary;
};
static void udp_set_dev_scratch(struct sk_buff *skb)
{
struct udp_dev_scratch *scratch;
@ -1197,22 +1180,6 @@ static int udp_skb_truesize(struct sk_buff *skb)
{
return ((struct udp_dev_scratch *)&skb->dev_scratch)->truesize;
}
static unsigned int udp_skb_len(struct sk_buff *skb)
{
return ((struct udp_dev_scratch *)&skb->dev_scratch)->len;
}
static bool udp_skb_csum_unnecessary(struct sk_buff *skb)
{
return ((struct udp_dev_scratch *)&skb->dev_scratch)->csum_unnecessary;
}
static bool udp_skb_is_linear(struct sk_buff *skb)
{
return ((struct udp_dev_scratch *)&skb->dev_scratch)->is_linear;
}
#else
static void udp_set_dev_scratch(struct sk_buff *skb)
{
@ -1223,21 +1190,6 @@ static int udp_skb_truesize(struct sk_buff *skb)
{
return skb->dev_scratch;
}
static unsigned int udp_skb_len(struct sk_buff *skb)
{
return skb->len;
}
static bool udp_skb_csum_unnecessary(struct sk_buff *skb)
{
return skb_csum_unnecessary(skb);
}
static bool udp_skb_is_linear(struct sk_buff *skb)
{
return !skb_is_nonlinear(skb);
}
#endif
/* fully reclaim rmem/fwd memory allocated for skb */
@ -1598,18 +1550,6 @@ busy_check:
}
EXPORT_SYMBOL_GPL(__skb_recv_udp);
static int copy_linear_skb(struct sk_buff *skb, int len, int off,
struct iov_iter *to)
{
int n, copy = len - off;
n = copy_to_iter(skb->data + off, copy, to);
if (n == copy)
return 0;
return -EFAULT;
}
/*
* This should be easy, if there is something there we
* return it, otherwise we block.