target/linux/generic/backport-5.15/702-v5.19-34-net-ethernet-mtk_eth_soc-fix-misuse-of-mem-alloc-int.patch

   1 From: Chen Lin <chen45464546@163.com>
   2 Date: Wed, 8 Jun 2022 20:46:53 +0800
   3 Subject: [PATCH] net: ethernet: mtk_eth_soc: fix misuse of mem alloc interface
   4  netdev[napi]_alloc_frag
   5
   6 When rx_flag == MTK_RX_FLAGS_HWLRO,
   7 rx_data_len = MTK_MAX_LRO_RX_LENGTH(4096 * 3) > PAGE_SIZE.
   8 netdev_alloc_frag is for alloction of page fragment only.
   9 Reference to other drivers and Documentation/vm/page_frags.rst
  10
  11 Branch to use __get_free_pages when ring->frag_size > PAGE_SIZE.
  12
  13 Signed-off-by: Chen Lin <chen45464546@163.com>
  14 Link: https://lore.kernel.org/r/1654692413-2598-1-git-send-email-chen45464546@163.com
  15 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  16 ---
  17
  18 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
  19 +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
  20 @@ -917,6 +917,17 @@ static bool mtk_rx_get_desc(struct mtk_e
  21         return true;
  22  }
  23
  24 +static void *mtk_max_lro_buf_alloc(gfp_t gfp_mask)
  25 +{
  26 +       unsigned int size = mtk_max_frag_size(MTK_MAX_LRO_RX_LENGTH);
  27 +       unsigned long data;
  28 +
  29 +       data = __get_free_pages(gfp_mask | __GFP_COMP | __GFP_NOWARN,
  30 +                               get_order(size));
  31 +
  32 +       return (void *)data;
  33 +}
  34 +
  35  /* the qdma core needs scratch memory to be setup */
  36  static int mtk_init_fq_dma(struct mtk_eth *eth)
  37  {
  38 @@ -1485,7 +1496,10 @@ static int mtk_poll_rx(struct napi_struc
  39                         goto release_desc;
  40
  41                 /* alloc new buffer */
  42 -               new_data = napi_alloc_frag(ring->frag_size);
  43 +               if (ring->frag_size <= PAGE_SIZE)
  44 +                       new_data = napi_alloc_frag(ring->frag_size);
  45 +               else
  46 +                       new_data = mtk_max_lro_buf_alloc(GFP_ATOMIC);
  47                 if (unlikely(!new_data)) {
  48                         netdev->stats.rx_dropped++;
  49                         goto release_desc;
  50 @@ -1938,7 +1952,10 @@ static int mtk_rx_alloc(struct mtk_eth *
  51                 return -ENOMEM;
  52
  53         for (i = 0; i < rx_dma_size; i++) {
  54 -               ring->data[i] = netdev_alloc_frag(ring->frag_size);
  55 +               if (ring->frag_size <= PAGE_SIZE)
  56 +                       ring->data[i] = netdev_alloc_frag(ring->frag_size);
  57 +               else
  58 +                       ring->data[i] = mtk_max_lro_buf_alloc(GFP_KERNEL);
  59                 if (!ring->data[i])
  60                         return -ENOMEM;
  61         }