kernel: bump 5.4 to 5.4.92
[openwrt/openwrt.git] / target / linux / layerscape / patches-5.4 / 303-core-0001-net-readd-skb_recycle.patch
1 From 446a17652a69f749dd7a50b28e984c4904dc3aaf Mon Sep 17 00:00:00 2001
2 From: Madalin Bucur <madalin.bucur@freescale.com>
3 Date: Tue, 5 Jan 2016 12:12:07 +0200
4 Subject: [PATCH] net: readd skb_recycle()
5
6 Adding back skb_recycle() as it's used by the DPAA Ethernet driver.
7 This was removed from the upstream kernel because it was lacking users.
8
9 Signed-off-by: Madalin Bucur <madalin.bucur@freescale.com>
10 ---
11 include/linux/skbuff.h | 1 +
12 net/core/skbuff.c | 26 ++++++++++++++++++++++++++
13 2 files changed, 27 insertions(+)
14
15 --- a/include/linux/skbuff.h
16 +++ b/include/linux/skbuff.h
17 @@ -1025,6 +1025,7 @@ void skb_dump(const char *level, const s
18 void skb_tx_error(struct sk_buff *skb);
19 void consume_skb(struct sk_buff *skb);
20 void __consume_stateless_skb(struct sk_buff *skb);
21 +void skb_recycle(struct sk_buff *skb);
22 void __kfree_skb(struct sk_buff *skb);
23 extern struct kmem_cache *skbuff_head_cache;
24
25 --- a/net/core/skbuff.c
26 +++ b/net/core/skbuff.c
27 @@ -941,6 +941,32 @@ void napi_consume_skb(struct sk_buff *sk
28 }
29 EXPORT_SYMBOL(napi_consume_skb);
30
31 +/**
32 + * skb_recycle - clean up an skb for reuse
33 + * @skb: buffer
34 + *
35 + * Recycles the skb to be reused as a receive buffer. This
36 + * function does any necessary reference count dropping, and
37 + * cleans up the skbuff as if it just came from __alloc_skb().
38 + */
39 +void skb_recycle(struct sk_buff *skb)
40 +{
41 + struct skb_shared_info *shinfo;
42 + u8 head_frag = skb->head_frag;
43 +
44 + skb_release_head_state(skb);
45 +
46 + shinfo = skb_shinfo(skb);
47 + memset(shinfo, 0, offsetof(struct skb_shared_info, dataref));
48 + atomic_set(&shinfo->dataref, 1);
49 +
50 + memset(skb, 0, offsetof(struct sk_buff, tail));
51 + skb->data = skb->head + NET_SKB_PAD;
52 + skb->head_frag = head_frag;
53 + skb_reset_tail_pointer(skb);
54 +}
55 +EXPORT_SYMBOL(skb_recycle);
56 +
57 /* Make sure a field is enclosed inside headers_start/headers_end section */
58 #define CHECK_SKB_FIELD(field) \
59 BUILD_BUG_ON(offsetof(struct sk_buff, field) < \