Add an skb_copier, skb_nocache_copier, which contains function pointers to
nontemporal copy routines.
Using skb_nocache_copier and do_skb_copy_datagram implement
skb_copy_datagram_from_iter_nocache. This function is intended to be used
by callers which would like to copy data into SKBs using nontemporal
instructions to avoid the CPU cache.
Signed-off-by: Joe Damato <[email protected]>
---
include/linux/skbuff.h | 2 ++
net/core/datagram.c | 12 ++++++++++++
2 files changed, 14 insertions(+)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 97de40b..32c0cba 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3918,6 +3918,8 @@ int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset,
struct ahash_request *hash);
int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
struct iov_iter *from, int len);
+int skb_copy_datagram_from_iter_nocache(struct sk_buff *skb, int offset,
+ struct iov_iter *from, int len);
int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
void __skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb, int len);
diff --git a/net/core/datagram.c b/net/core/datagram.c
index a87c41b..da8557b 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -543,6 +543,11 @@ struct skb_copier skb_copier = {
.copy_page_from_iter = copy_page_from_iter
};
+struct skb_copier skb_nocache_copier = {
+ .copy_from_iter = copy_from_iter_nocache,
+ .copy_page_from_iter = copy_page_from_iter_nocache
+};
+
static int do_skb_copy_datagram(struct sk_buff *skb, int offset,
struct iov_iter *from, int len, struct skb_copier copier)
{
@@ -611,6 +616,13 @@ static int do_skb_copy_datagram(struct sk_buff *skb, int offset,
return -EFAULT;
}
+int skb_copy_datagram_from_iter_nocache(struct sk_buff *skb, int offset,
+ struct iov_iter *from, int len)
+{
+ return do_skb_copy_datagram(skb, offset, from, len, skb_nocache_copier);
+}
+EXPORT_SYMBOL(skb_copy_datagram_from_iter_nocache);
+
/**
* skb_copy_datagram_from_iter - Copy a datagram from an iov_iter.
* @skb: buffer to copy
--
2.7.4