target/linux/mvebu/patches-5.4/004-net-mvneta-introduce-page-pool-API-for-sw-buffer-man.patch

   1 From 568a3fa24a95476d40afe3f8616bafb543bc4182 Mon Sep 17 00:00:00 2001
   2 From: Lorenzo Bianconi <lorenzo@kernel.org>
   3 Date: Sat, 19 Oct 2019 10:13:22 +0200
   4 Subject: [PATCH 2/7] net: mvneta: introduce page pool API for sw buffer
   5  manager
   6
   7 Use the page_pool api for allocations and DMA handling instead of
   8 __dev_alloc_page()/dma_map_page() and free_page()/dma_unmap_page().
   9 Pages are unmapped using page_pool_release_page before packets
  10 go into the network stack.
  11
  12 The page_pool API offers buffer recycling capabilities for XDP but
  13 allocates one page per packet, unless the driver splits and manages
  14 the allocated page.
  15 This is a preliminary patch to add XDP support to mvneta driver
  16
  17 Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
  18 Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
  19 Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
  20 Signed-off-by: David S. Miller <davem@davemloft.net>
  21 ---
  22  drivers/net/ethernet/marvell/Kconfig  |  1 +
  23  drivers/net/ethernet/marvell/mvneta.c | 83 +++++++++++++++++++++------
  24  2 files changed, 65 insertions(+), 19 deletions(-)
  25
  26 --- a/drivers/net/ethernet/marvell/Kconfig
  27 +++ b/drivers/net/ethernet/marvell/Kconfig
  28 @@ -61,6 +61,7 @@ config MVNETA
  29         depends on ARCH_MVEBU || COMPILE_TEST
  30         select MVMDIO
  31         select PHYLINK
  32 +       select PAGE_POOL
  33         ---help---
  34           This driver supports the network interface units in the
  35           Marvell ARMADA XP, ARMADA 370, ARMADA 38x and
  36 --- a/drivers/net/ethernet/marvell/mvneta.c
  37 +++ b/drivers/net/ethernet/marvell/mvneta.c
  38 @@ -37,6 +37,7 @@
  39  #include <net/ip.h>
  40  #include <net/ipv6.h>
  41  #include <net/tso.h>
  42 +#include <net/page_pool.h>
  43
  44  /* Registers */
  45  #define MVNETA_RXQ_CONFIG_REG(q)                (0x1400 + ((q) << 2))
  46 @@ -607,6 +608,10 @@ struct mvneta_rx_queue {
  47         u32 pkts_coal;
  48         u32 time_coal;
  49
  50 +       /* page_pool */
  51 +       struct page_pool *page_pool;
  52 +       struct xdp_rxq_info xdp_rxq;
  53 +
  54         /* Virtual address of the RX buffer */
  55         void  **buf_virt_addr;
  56
  57 @@ -1825,23 +1830,21 @@ static int mvneta_rx_refill(struct mvnet
  58                             struct mvneta_rx_queue *rxq,
  59                             gfp_t gfp_mask)
  60  {
  61 +       enum dma_data_direction dma_dir;
  62         dma_addr_t phys_addr;
  63         struct page *page;
  64
  65 -       page = __dev_alloc_page(gfp_mask);
  66 +       page = page_pool_alloc_pages(rxq->page_pool,
  67 +                                    gfp_mask | __GFP_NOWARN);
  68         if (!page)
  69                 return -ENOMEM;
  70
  71 -       /* map page for use */
  72 -       phys_addr = dma_map_page(pp->dev->dev.parent, page, 0, PAGE_SIZE,
  73 -                                DMA_FROM_DEVICE);
  74 -       if (unlikely(dma_mapping_error(pp->dev->dev.parent, phys_addr))) {
  75 -               __free_page(page);
  76 -               return -ENOMEM;
  77 -       }
  78 -
  79 -       phys_addr += pp->rx_offset_correction;
  80 +       phys_addr = page_pool_get_dma_addr(page) + pp->rx_offset_correction;
  81 +       dma_dir = page_pool_get_dma_dir(rxq->page_pool);
  82 +       dma_sync_single_for_device(pp->dev->dev.parent, phys_addr,
  83 +                                  PAGE_SIZE, dma_dir);
  84         mvneta_rx_desc_fill(rx_desc, phys_addr, page, rxq);
  85 +
  86         return 0;
  87  }
  88
  89 @@ -1907,10 +1910,12 @@ static void mvneta_rxq_drop_pkts(struct
  90                 if (!data || !(rx_desc->buf_phys_addr))
  91                         continue;
  92
  93 -               dma_unmap_page(pp->dev->dev.parent, rx_desc->buf_phys_addr,
  94 -                              PAGE_SIZE, DMA_FROM_DEVICE);
  95 -               __free_page(data);
  96 +               page_pool_put_page(rxq->page_pool, data, false);
  97         }
  98 +       if (xdp_rxq_info_is_reg(&rxq->xdp_rxq))
  99 +               xdp_rxq_info_unreg(&rxq->xdp_rxq);
 100 +       page_pool_destroy(rxq->page_pool);
 101 +       rxq->page_pool = NULL;
 102  }
 103
 104  static void
 105 @@ -2047,8 +2052,7 @@ static int mvneta_rx_swbm(struct napi_st
 106                                 skb_add_rx_frag(rxq->skb, frag_num, page,
 107                                                 frag_offset, frag_size,
 108                                                 PAGE_SIZE);
 109 -                               dma_unmap_page(dev->dev.parent, phys_addr,
 110 -                                              PAGE_SIZE, DMA_FROM_DEVICE);
 111 +                               page_pool_release_page(rxq->page_pool, page);
 112                                 rxq->left_size -= frag_size;
 113                         }
 114                 } else {
 115 @@ -2078,9 +2082,7 @@ static int mvneta_rx_swbm(struct napi_st
 116                                                 frag_offset, frag_size,
 117                                                 PAGE_SIZE);
 118
 119 -                               dma_unmap_page(dev->dev.parent, phys_addr,
 120 -                                              PAGE_SIZE, DMA_FROM_DEVICE);
 121 -
 122 +                               page_pool_release_page(rxq->page_pool, page);
 123                                 rxq->left_size -= frag_size;
 124                         }
 125                 } /* Middle or Last descriptor */
 126 @@ -2847,11 +2849,54 @@ static int mvneta_poll(struct napi_struc
 127         return rx_done;
 128  }
 129
 130 +static int mvneta_create_page_pool(struct mvneta_port *pp,
 131 +                                  struct mvneta_rx_queue *rxq, int size)
 132 +{
 133 +       struct page_pool_params pp_params = {
 134 +               .order = 0,
 135 +               .flags = PP_FLAG_DMA_MAP,
 136 +               .pool_size = size,
 137 +               .nid = cpu_to_node(0),
 138 +               .dev = pp->dev->dev.parent,
 139 +               .dma_dir = DMA_FROM_DEVICE,
 140 +       };
 141 +       int err;
 142 +
 143 +       rxq->page_pool = page_pool_create(&pp_params);
 144 +       if (IS_ERR(rxq->page_pool)) {
 145 +               err = PTR_ERR(rxq->page_pool);
 146 +               rxq->page_pool = NULL;
 147 +               return err;
 148 +       }
 149 +
 150 +       err = xdp_rxq_info_reg(&rxq->xdp_rxq, pp->dev, rxq->id);
 151 +       if (err < 0)
 152 +               goto err_free_pp;
 153 +
 154 +       err = xdp_rxq_info_reg_mem_model(&rxq->xdp_rxq, MEM_TYPE_PAGE_POOL,
 155 +                                        rxq->page_pool);
 156 +       if (err)
 157 +               goto err_unregister_rxq;
 158 +
 159 +       return 0;
 160 +
 161 +err_unregister_rxq:
 162 +       xdp_rxq_info_unreg(&rxq->xdp_rxq);
 163 +err_free_pp:
 164 +       page_pool_destroy(rxq->page_pool);
 165 +       rxq->page_pool = NULL;
 166 +       return err;
 167 +}
 168 +
 169  /* Handle rxq fill: allocates rxq skbs; called when initializing a port */
 170  static int mvneta_rxq_fill(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
 171                            int num)
 172  {
 173 -       int i;
 174 +       int i, err;
 175 +
 176 +       err = mvneta_create_page_pool(pp, rxq, num);
 177 +       if (err < 0)
 178 +               return err;
 179
 180         for (i = 0; i < num; i++) {
 181                 memset(rxq->descs + i, 0, sizeof(struct mvneta_rx_desc));