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 @@ -936,6 +936,32 @@ 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) <          \