openwrt-owl/target/linux/layerscape/patches-4.4/7019-net-readd-skb_recycle....

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Diff

From abc24ef7a69f54c3317beea98078831ba9bfa2cd Mon Sep 17 00:00:00 2001
From: Madalin Bucur <madalin.bucur@freescale.com>
Date: Tue, 5 Jan 2016 12:12:07 +0200
Subject: [PATCH 19/70] net: readd skb_recycle()
Adding back skb_recycle() as it's used by the DPAA Ethernet driver.
This was removed from the upstream kernel because it was lacking users.
Signed-off-by: Madalin Bucur <madalin.bucur@freescale.com>
---
include/linux/skbuff.h | 1 +
net/core/skbuff.c | 26 ++++++++++++++++++++++++++
2 files changed, 27 insertions(+)
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -799,6 +799,7 @@ void kfree_skb(struct sk_buff *skb);
void kfree_skb_list(struct sk_buff *segs);
void skb_tx_error(struct sk_buff *skb);
void consume_skb(struct sk_buff *skb);
+void skb_recycle(struct sk_buff *skb);
void __kfree_skb(struct sk_buff *skb);
extern struct kmem_cache *skbuff_head_cache;
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -766,6 +766,32 @@ void consume_skb(struct sk_buff *skb)
}
EXPORT_SYMBOL(consume_skb);
+/**
+ * skb_recycle - clean up an skb for reuse
+ * @skb: buffer
+ *
+ * Recycles the skb to be reused as a receive buffer. This
+ * function does any necessary reference count dropping, and
+ * cleans up the skbuff as if it just came from __alloc_skb().
+ */
+void skb_recycle(struct sk_buff *skb)
+{
+ struct skb_shared_info *shinfo;
+ u8 head_frag = skb->head_frag;
+
+ skb_release_head_state(skb);
+
+ shinfo = skb_shinfo(skb);
+ memset(shinfo, 0, offsetof(struct skb_shared_info, dataref));
+ atomic_set(&shinfo->dataref, 1);
+
+ memset(skb, 0, offsetof(struct sk_buff, tail));
+ skb->data = skb->head + NET_SKB_PAD;
+ skb->head_frag = head_frag;
+ skb_reset_tail_pointer(skb);
+}
+EXPORT_SYMBOL(skb_recycle);
+
/* Make sure a field is enclosed inside headers_start/headers_end section */
#define CHECK_SKB_FIELD(field) \
BUILD_BUG_ON(offsetof(struct sk_buff, field) < \