target/linux/layerscape/patches-5.4/701-net-0025-sdk_dpaa-ls1043a-errata-do-not-recycle-the-realigned.patch

   1 From e8c0a77a831843a66b3ac0048aa6c76bc39b0332 Mon Sep 17 00:00:00 2001
   2 From: Camelia Groza <camelia.groza@nxp.com>
   3 Date: Mon, 4 Sep 2017 14:03:01 +0300
   4 Subject: [PATCH] sdk_dpaa: ls1043a errata: do not recycle the realigned
   5  buffers
   6
   7 Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
   8 ---
   9  drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth.h    | 10 ++++++----
  10  drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c |  9 +++++++++
  11  2 files changed, 15 insertions(+), 4 deletions(-)
  12
  13 --- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth.h
  14 +++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth.h
  15 @@ -680,15 +680,17 @@ static inline void _dpa_bp_free_pf(void
  16         put_page(virt_to_head_page(addr));
  17  }
  18
  19 -/* TODO: LS1043A SoC has a HW issue regarding FMan DMA transactions; The issue
  20 - * manifests itself at high traffic rates when frames exceed 4K memory
  21 - * boundaries; For the moment, we use a SW workaround to avoid frames larger
  22 - * than 4K or that exceed 4K alignments.
  23 +/* LS1043A SoC has a HW issue regarding FMan DMA transactions; The issue
  24 + * manifests itself at high traffic rates when frames cross 4K memory
  25 + * boundaries or when they are not aligned to 16 bytes; For the moment, we
  26 + * use a SW workaround to avoid frames larger than 4K or that exceed 4K
  27 + * alignments and to realign the frames to 16 bytes.
  28   */
  29
  30  #ifndef CONFIG_PPC
  31  extern bool dpaa_errata_a010022; /* SoC affected by A010022 errata */
  32
  33 +#define NONREC_MARK    0x01
  34  #define HAS_DMA_ISSUE(start, size) \
  35         (((u64)(start) + (size)) > (((u64)(start) + 0x1000) & ~0xFFF))
  36  #define BOUNDARY_4K(start, size) (((u64)(start) + (u64)(size)) & ~0xFFF)
  37 --- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
  38 +++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
  39 @@ -302,6 +302,12 @@ EXPORT_SYMBOL(_dpa_cleanup_tx_fd);
  40  #ifndef CONFIG_FSL_DPAA_TS
  41  bool dpa_skb_is_recyclable(struct sk_buff *skb)
  42  {
  43 +#ifndef CONFIG_PPC
  44 +       /* Do no recycle skbs realigned by the errata workaround */
  45 +       if (unlikely(dpaa_errata_a010022) && skb->mark == NONREC_MARK)
  46 +               return false;
  47 +#endif
  48 +
  49         /* No recycling possible if skb buffer is kmalloc'ed  */
  50         if (skb->head_frag == 0)
  51                 return false;
  52 @@ -838,6 +844,9 @@ static struct sk_buff *a010022_realign_s
  53         skb_set_network_header(nskb, net_offset);
  54         skb_set_transport_header(nskb, trans_offset);
  55
  56 +       /* We don't want the buffer to be recycled so we mark it accordingly */
  57 +       nskb->mark = NONREC_MARK;
  58 +
  59         dev_kfree_skb(skb);
  60         return nskb;
  61