drivers/net/ethernet/intel/ice/ice_txrx_lib.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (c) 2019, Intel Corporation. */
   3
   4 #include "ice_txrx_lib.h"
   5
   6 /**
   7  * ice_release_rx_desc - Store the new tail and head values
   8  * @rx_ring: ring to bump
   9  * @val: new head index
  10  */
  11 void ice_release_rx_desc(struct ice_ring *rx_ring, u16 val)
  12 {
  13         u16 prev_ntu = rx_ring->next_to_use & ~0x7;
  14
  15         rx_ring->next_to_use = val;
  16
  17         /* update next to alloc since we have filled the ring */
  18         rx_ring->next_to_alloc = val;
  19
  20         /* QRX_TAIL will be updated with any tail value, but hardware ignores
  21          * the lower 3 bits. This makes it so we only bump tail on meaningful
  22          * boundaries. Also, this allows us to bump tail on intervals of 8 up to
  23          * the budget depending on the current traffic load.
  24          */
  25         val &= ~0x7;
  26         if (prev_ntu != val) {
  27                 /* Force memory writes to complete before letting h/w
  28                  * know there are new descriptors to fetch. (Only
  29                  * applicable for weak-ordered memory model archs,
  30                  * such as IA-64).
  31                  */
  32                 wmb();
  33                 writel(val, rx_ring->tail);
  34         }
  35 }
  36
  37 /**
  38  * ice_ptype_to_htype - get a hash type
  39  * @ptype: the ptype value from the descriptor
  40  *
  41  * Returns a hash type to be used by skb_set_hash
  42  */
  43 static enum pkt_hash_types ice_ptype_to_htype(u8 __always_unused ptype)
  44 {
  45         return PKT_HASH_TYPE_NONE;
  46 }
  47
  48 /**
  49  * ice_rx_hash - set the hash value in the skb
  50  * @rx_ring: descriptor ring
  51  * @rx_desc: specific descriptor
  52  * @skb: pointer to current skb
  53  * @rx_ptype: the ptype value from the descriptor
  54  */
  55 static void
  56 ice_rx_hash(struct ice_ring *rx_ring, union ice_32b_rx_flex_desc *rx_desc,
  57             struct sk_buff *skb, u8 rx_ptype)
  58 {
  59         struct ice_32b_rx_flex_desc_nic *nic_mdid;
  60         u32 hash;
  61
  62         if (!(rx_ring->netdev->features & NETIF_F_RXHASH))
  63                 return;
  64
  65         if (rx_desc->wb.rxdid != ICE_RXDID_FLEX_NIC)
  66                 return;
  67
  68         nic_mdid = (struct ice_32b_rx_flex_desc_nic *)rx_desc;
  69         hash = le32_to_cpu(nic_mdid->rss_hash);
  70         skb_set_hash(skb, hash, ice_ptype_to_htype(rx_ptype));
  71 }
  72
  73 /**
  74  * ice_rx_csum - Indicate in skb if checksum is good
  75  * @ring: the ring we care about
  76  * @skb: skb currently being received and modified
  77  * @rx_desc: the receive descriptor
  78  * @ptype: the packet type decoded by hardware
  79  *
  80  * skb->protocol must be set before this function is called
  81  */
  82 static void
  83 ice_rx_csum(struct ice_ring *ring, struct sk_buff *skb,
  84             union ice_32b_rx_flex_desc *rx_desc, u8 ptype)
  85 {
  86         struct ice_rx_ptype_decoded decoded;
  87         u16 rx_status0, rx_status1;
  88         bool ipv4, ipv6;
  89
  90         rx_status0 = le16_to_cpu(rx_desc->wb.status_error0);
  91         rx_status1 = le16_to_cpu(rx_desc->wb.status_error1);
  92
  93         decoded = ice_decode_rx_desc_ptype(ptype);
  94
  95         /* Start with CHECKSUM_NONE and by default csum_level = 0 */
  96         skb->ip_summed = CHECKSUM_NONE;
  97         skb_checksum_none_assert(skb);
  98
  99         /* check if Rx checksum is enabled */
 100         if (!(ring->netdev->features & NETIF_F_RXCSUM))
 101                 return;
 102
 103         /* check if HW has decoded the packet and checksum */
 104         if (!(rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_L3L4P_S)))
 105                 return;
 106
 107         if (!(decoded.known && decoded.outer_ip))
 108                 return;
 109
 110         ipv4 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
 111                (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV4);
 112         ipv6 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
 113                (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV6);
 114
 115         if (ipv4 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_IPE_S) |
 116                                    BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EIPE_S))))
 117                 goto checksum_fail;
 118
 119         if (ipv6 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_IPV6EXADD_S))))
 120                 goto checksum_fail;
 121
 122         /* check for L4 errors and handle packets that were not able to be
 123          * checksummed due to arrival speed
 124          */
 125         if (rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_L4E_S))
 126                 goto checksum_fail;
 127
 128         /* check for outer UDP checksum error in tunneled packets */
 129         if ((rx_status1 & BIT(ICE_RX_FLEX_DESC_STATUS1_NAT_S)) &&
 130             (rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EUDPE_S)))
 131                 goto checksum_fail;
 132
 133         /* If there is an outer header present that might contain a checksum
 134          * we need to bump the checksum level by 1 to reflect the fact that
 135          * we are indicating we validated the inner checksum.
 136          */
 137         if (decoded.tunnel_type >= ICE_RX_PTYPE_TUNNEL_IP_GRENAT)
 138                 skb->csum_level = 1;
 139
 140         /* Only report checksum unnecessary for TCP, UDP, or SCTP */
 141         switch (decoded.inner_prot) {
 142         case ICE_RX_PTYPE_INNER_PROT_TCP:
 143         case ICE_RX_PTYPE_INNER_PROT_UDP:
 144         case ICE_RX_PTYPE_INNER_PROT_SCTP:
 145                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 146         default:
 147                 break;
 148         }
 149         return;
 150
 151 checksum_fail:
 152         ring->vsi->back->hw_csum_rx_error++;
 153 }
 154
 155 /**
 156  * ice_process_skb_fields - Populate skb header fields from Rx descriptor
 157  * @rx_ring: Rx descriptor ring packet is being transacted on
 158  * @rx_desc: pointer to the EOP Rx descriptor
 159  * @skb: pointer to current skb being populated
 160  * @ptype: the packet type decoded by hardware
 161  *
 162  * This function checks the ring, descriptor, and packet information in
 163  * order to populate the hash, checksum, VLAN, protocol, and
 164  * other fields within the skb.
 165  */
 166 void
 167 ice_process_skb_fields(struct ice_ring *rx_ring,
 168                        union ice_32b_rx_flex_desc *rx_desc,
 169                        struct sk_buff *skb, u8 ptype)
 170 {
 171         ice_rx_hash(rx_ring, rx_desc, skb, ptype);
 172
 173         /* modifies the skb - consumes the enet header */
 174         skb->protocol = eth_type_trans(skb, rx_ring->netdev);
 175
 176         ice_rx_csum(rx_ring, skb, rx_desc, ptype);
 177 }
 178
 179 /**
 180  * ice_receive_skb - Send a completed packet up the stack
 181  * @rx_ring: Rx ring in play
 182  * @skb: packet to send up
 183  * @vlan_tag: VLAN tag for packet
 184  *
 185  * This function sends the completed packet (via. skb) up the stack using
 186  * gro receive functions (with/without VLAN tag)
 187  */
 188 void
 189 ice_receive_skb(struct ice_ring *rx_ring, struct sk_buff *skb, u16 vlan_tag)
 190 {
 191         if ((rx_ring->netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
 192             (vlan_tag & VLAN_VID_MASK))
 193                 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
 194         if (napi_gro_receive(&rx_ring->q_vector->napi, skb) == GRO_DROP) {
 195                 /* this is tracked separately to help us debug stack drops */
 196                 rx_ring->rx_stats.gro_dropped++;
 197                 netdev_dbg(rx_ring->netdev, "Receive Queue %d: Dropped packet from GRO\n",
 198                            rx_ring->q_index);
 199         }
 200 }
 201
 202 /**
 203  * ice_xmit_xdp_ring - submit single packet to XDP ring for transmission
 204  * @data: packet data pointer
 205  * @size: packet data size
 206  * @xdp_ring: XDP ring for transmission
 207  */
 208 int ice_xmit_xdp_ring(void *data, u16 size, struct ice_ring *xdp_ring)
 209 {
 210         u16 i = xdp_ring->next_to_use;
 211         struct ice_tx_desc *tx_desc;
 212         struct ice_tx_buf *tx_buf;
 213         dma_addr_t dma;
 214
 215         if (!unlikely(ICE_DESC_UNUSED(xdp_ring))) {
 216                 xdp_ring->tx_stats.tx_busy++;
 217                 return ICE_XDP_CONSUMED;
 218         }
 219
 220         dma = dma_map_single(xdp_ring->dev, data, size, DMA_TO_DEVICE);
 221         if (dma_mapping_error(xdp_ring->dev, dma))
 222                 return ICE_XDP_CONSUMED;
 223
 224         tx_buf = &xdp_ring->tx_buf[i];
 225         tx_buf->bytecount = size;
 226         tx_buf->gso_segs = 1;
 227         tx_buf->raw_buf = data;
 228
 229         /* record length, and DMA address */
 230         dma_unmap_len_set(tx_buf, len, size);
 231         dma_unmap_addr_set(tx_buf, dma, dma);
 232
 233         tx_desc = ICE_TX_DESC(xdp_ring, i);
 234         tx_desc->buf_addr = cpu_to_le64(dma);
 235         tx_desc->cmd_type_offset_bsz = ice_build_ctob(ICE_TXD_LAST_DESC_CMD, 0,
 236                                                       size, 0);
 237
 238         /* Make certain all of the status bits have been updated
 239          * before next_to_watch is written.
 240          */
 241         smp_wmb();
 242
 243         i++;
 244         if (i == xdp_ring->count)
 245                 i = 0;
 246
 247         tx_buf->next_to_watch = tx_desc;
 248         xdp_ring->next_to_use = i;
 249
 250         return ICE_XDP_TX;
 251 }
 252
 253 /**
 254  * ice_xmit_xdp_buff - convert an XDP buffer to an XDP frame and send it
 255  * @xdp: XDP buffer
 256  * @xdp_ring: XDP Tx ring
 257  *
 258  * Returns negative on failure, 0 on success.
 259  */
 260 int ice_xmit_xdp_buff(struct xdp_buff *xdp, struct ice_ring *xdp_ring)
 261 {
 262         struct xdp_frame *xdpf = xdp_convert_buff_to_frame(xdp);
 263
 264         if (unlikely(!xdpf))
 265                 return ICE_XDP_CONSUMED;
 266
 267         return ice_xmit_xdp_ring(xdpf->data, xdpf->len, xdp_ring);
 268 }
 269
 270 /**
 271  * ice_finalize_xdp_rx - Bump XDP Tx tail and/or flush redirect map
 272  * @rx_ring: Rx ring
 273  * @xdp_res: Result of the receive batch
 274  *
 275  * This function bumps XDP Tx tail and/or flush redirect map, and
 276  * should be called when a batch of packets has been processed in the
 277  * napi loop.
 278  */
 279 void ice_finalize_xdp_rx(struct ice_ring *rx_ring, unsigned int xdp_res)
 280 {
 281         if (xdp_res & ICE_XDP_REDIR)
 282                 xdp_do_flush_map();
 283
 284         if (xdp_res & ICE_XDP_TX) {
 285                 struct ice_ring *xdp_ring =
 286                         rx_ring->vsi->xdp_rings[rx_ring->q_index];
 287
 288                 ice_xdp_ring_update_tail(xdp_ring);
 289         }
 290 }