target/linux/layerscape/patches-4.9/601-net-readd-skb_recycle.patch

   1 From 9527ee5eb436ad773acc7320b372a5f4825a920d 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 diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
  16 index 32810f279f8e..a52a6fb0ac2e 100644
  17 --- a/include/linux/skbuff.h
  18 +++ b/include/linux/skbuff.h
  19 @@ -902,6 +902,7 @@ void kfree_skb(struct sk_buff *skb);
  20  void kfree_skb_list(struct sk_buff *segs);
  21  void skb_tx_error(struct sk_buff *skb);
  22  void consume_skb(struct sk_buff *skb);
  23 +void skb_recycle(struct sk_buff *skb);
  24  void  __kfree_skb(struct sk_buff *skb);
  25  extern struct kmem_cache *skbuff_head_cache;
  26
  27 diff --git a/net/core/skbuff.c b/net/core/skbuff.c
  28 index fe008f1bd930..ab1038083df2 100644
  29 --- a/net/core/skbuff.c
  30 +++ b/net/core/skbuff.c
  31 @@ -825,6 +825,32 @@ void napi_consume_skb(struct sk_buff *skb, int budget)
  32  }
  33  EXPORT_SYMBOL(napi_consume_skb);
  34
  35 +/**
  36 + *     skb_recycle - clean up an skb for reuse
  37 + *     @skb: buffer
  38 + *
  39 + *     Recycles the skb to be reused as a receive buffer. This
  40 + *     function does any necessary reference count dropping, and
  41 + *     cleans up the skbuff as if it just came from __alloc_skb().
  42 + */
  43 +void skb_recycle(struct sk_buff *skb)
  44 +{
  45 +       struct skb_shared_info *shinfo;
  46 +       u8 head_frag = skb->head_frag;
  47 +
  48 +       skb_release_head_state(skb);
  49 +
  50 +       shinfo = skb_shinfo(skb);
  51 +       memset(shinfo, 0, offsetof(struct skb_shared_info, dataref));
  52 +       atomic_set(&shinfo->dataref, 1);
  53 +
  54 +       memset(skb, 0, offsetof(struct sk_buff, tail));
  55 +       skb->data = skb->head + NET_SKB_PAD;
  56 +       skb->head_frag = head_frag;
  57 +       skb_reset_tail_pointer(skb);
  58 +}
  59 +EXPORT_SYMBOL(skb_recycle);
  60 +
  61  /* Make sure a field is enclosed inside headers_start/headers_end section */
  62  #define CHECK_SKB_FIELD(field) \
  63         BUILD_BUG_ON(offsetof(struct sk_buff, field) <          \
  64 --
  65 2.11.1
  66