target/linux/layerscape/patches-5.4/701-net-0075-sdk_dpaa-reserve-256-bytes-for-the-SGT-on-TX.patch

   1 From 29757ae2e4a0e8e1e816c9eeef59121908320669 Mon Sep 17 00:00:00 2001
   2 From: Camelia Groza <camelia.groza@nxp.com>
   3 Date: Wed, 20 Jun 2018 18:00:42 +0300
   4 Subject: [PATCH] sdk_dpaa: reserve 256 bytes for the SGT on TX
   5
   6 The FMan reads 256 bytes from the start of the SGT regardless of its
   7 size. We reserve the same amount of memory on TX to access.
   8
   9 Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
  10 ---
  11  drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_common.h |  6 ++++--
  12  drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c     | 10 +++++++---
  13  2 files changed, 11 insertions(+), 5 deletions(-)
  14
  15 --- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_common.h
  16 +++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_common.h
  17 @@ -55,10 +55,12 @@
  18         fm_set_##type##_port_params(port, &param); \
  19  }
  20
  21 +/* The SGT needs to be 256 bytes long. Even if the table has only one entry,
  22 + * the FMan will read 256 bytes from its start.
  23 + */
  24 +#define DPA_SGT_SIZE 256
  25  #define DPA_SGT_MAX_ENTRIES 16 /* maximum number of entries in SG Table */
  26
  27 -#define DPA_SGT_ENTRIES_THRESHOLD      DPA_SGT_MAX_ENTRIES
  28 -
  29  #define DPA_BUFF_RELEASE_MAX 8 /* maximum number of buffers released at once */
  30
  31  #define DPA_RX_PCD_HI_PRIO_FQ_INIT_FAIL(dpa_fq, _errno) \
  32 --- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
  33 +++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
  34 @@ -246,8 +246,8 @@ struct sk_buff *_dpa_cleanup_tx_fd(const
  35
  36         if (unlikely(fd->format == qm_fd_sg)) {
  37                 nr_frags = skb_shinfo(skb)->nr_frags;
  38 -               dma_unmap_single(dpa_bp->dev, addr, dpa_fd_offset(fd) +
  39 -                                sizeof(struct qm_sg_entry) * (1 + nr_frags),
  40 +               dma_unmap_single(dpa_bp->dev, addr,
  41 +                                dpa_fd_offset(fd) + DPA_SGT_SIZE,
  42                                  dma_dir);
  43
  44                 /* The sgt buffer has been allocated with netdev_alloc_frag(),
  45 @@ -896,7 +896,11 @@ int __hot skb_to_sg_fd(struct dpa_priv_s
  46         nr_frags = skb_shinfo(skb)->nr_frags;
  47         fd->format = qm_fd_sg;
  48
  49 -       sgt_size = sizeof(struct qm_sg_entry) * (1 + nr_frags);
  50 +       /* The FMan reads 256 bytes from the start of the SGT regardless of
  51 +        * its size. In accordance, we reserve the same amount of memory as
  52 +        * well.
  53 +        */
  54 +       sgt_size = DPA_SGT_SIZE;
  55
  56         /* Get a page frag to store the SGTable, or a full page if the errata
  57          * is in place and we need to avoid crossing a 4k boundary.