target/linux/layerscape/patches-5.4/701-net-0024-sdk_dpaa-ls1043a-errata-verify-and-resize-headroom-a.patch

   1 From f6413a7e32d1f98a258e0ed9abd4df3159902fd3 Mon Sep 17 00:00:00 2001
   2 From: Camelia Groza <camelia.groza@nxp.com>
   3 Date: Mon, 4 Sep 2017 13:57:21 +0300
   4 Subject: [PATCH] sdk_dpaa: ls1043a errata: verify and resize headroom
   5  alignment
   6
   7 If the skb's headroom isn't aligned to 16 bytes, reallocate the entire
   8 skb and resize its headroom to priv->tx_headroom. Update the pointers
   9 to the network and transport headers accordingly.
  10
  11 Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
  12 ---
  13  .../net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c  | 38 +++++++++++++++-------
  14  1 file changed, 27 insertions(+), 11 deletions(-)
  15
  16 --- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
  17 +++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
  18 @@ -742,14 +742,19 @@ int __hot skb_to_contig_fd(struct dpa_pr
  19  EXPORT_SYMBOL(skb_to_contig_fd);
  20
  21  #ifndef CONFIG_PPC
  22 -/* Verify the conditions that trigger the A010022 errata: 4K memory address
  23 - * crossings.
  24 +/* Verify the conditions that trigger the A010022 errata: data unaligned to
  25 + * 16 bytes and 4K memory address crossings.
  26   */
  27 -bool a010022_check_skb(struct sk_buff *skb)
  28 +static bool a010022_check_skb(struct sk_buff *skb, struct dpa_priv_s *priv)
  29  {
  30         int nr_frags, i = 0;
  31         skb_frag_t *frag;
  32
  33 +       /* Check if the headroom is aligned */
  34 +       if (((u16)skb->data - priv->tx_headroom) %
  35 +           priv->buf_layout[TX].data_align != 0)
  36 +               return true;
  37 +
  38         /* Check if the headroom crosses a boundary */
  39         if (HAS_DMA_ISSUE(skb->head, skb_headroom(skb)))
  40                 return true;
  41 @@ -767,7 +772,7 @@ bool a010022_check_skb(struct sk_buff *s
  42         while (i < nr_frags) {
  43                 frag = &skb_shinfo(skb)->frags[i];
  44
  45 -               /* Check if the paged fragment crosses a boundary from its
  46 +               /* Check if a paged fragment crosses a boundary from its
  47                  * offset to its end.
  48                  */
  49                 if (HAS_DMA_ISSUE(frag->page_offset, frag->size))
  50 @@ -783,13 +788,17 @@ bool a010022_check_skb(struct sk_buff *s
  51   * page. Build a new skb around the new buffer and release the old one.
  52   * A performance drop should be expected.
  53   */
  54 -struct sk_buff *a010022_realign_skb(struct sk_buff *skb)
  55 +static struct sk_buff *a010022_realign_skb(struct sk_buff *skb,
  56 +                                          struct dpa_priv_s *priv)
  57  {
  58 -       int headroom = skb_headroom(skb);
  59 +       int trans_offset = skb_transport_offset(skb);
  60 +       int net_offset = skb_network_offset(skb);
  61         struct sk_buff *nskb = NULL;
  62 +       int nsize, headroom;
  63         struct page *npage;
  64         void *npage_addr;
  65 -       int nsize;
  66 +
  67 +       headroom = priv->tx_headroom;
  68
  69         npage = alloc_page(GFP_ATOMIC);
  70         if (unlikely(!npage)) {
  71 @@ -822,6 +831,13 @@ struct sk_buff *a010022_realign_skb(stru
  72         }
  73         copy_skb_header(nskb, skb);
  74
  75 +       /* We move the headroom when we align it so we have to reset the
  76 +        * network and transport header offsets relative to the new data
  77 +        * pointer. The checksum offload relies on these offsets.
  78 +        */
  79 +       skb_set_network_header(nskb, net_offset);
  80 +       skb_set_transport_header(nskb, trans_offset);
  81 +
  82         dev_kfree_skb(skb);
  83         return nskb;
  84
  85 @@ -1024,8 +1040,8 @@ int __hot dpa_tx_extended(struct sk_buff
  86  #endif /* CONFIG_FSL_DPAA_TS */
  87
  88  #ifndef CONFIG_PPC
  89 -       if (unlikely(dpaa_errata_a010022) && a010022_check_skb(skb)) {
  90 -               skb = a010022_realign_skb(skb);
  91 +       if (unlikely(dpaa_errata_a010022) && a010022_check_skb(skb, priv)) {
  92 +               skb = a010022_realign_skb(skb, priv);
  93                 if (!skb)
  94                         goto skb_to_fd_failed;
  95         }
  96 @@ -1072,8 +1088,8 @@ int __hot dpa_tx_extended(struct sk_buff
  97                         skb = nskb;
  98  #ifndef CONFIG_PPC
  99                         if (unlikely(dpaa_errata_a010022) &&
 100 -                           a010022_check_skb(skb)) {
 101 -                               skb = realign_skb(skb);
 102 +                           a010022_check_skb(skb, priv)) {
 103 +                               skb = a010022_realign_skb(skb, priv);
 104                                 if (!skb)
 105                                         goto skb_to_fd_failed;
 106                         }