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                 break;
 147         default:
 148                 break;
 149         }
 150         return;
 151
 152 checksum_fail:
 153         ring->vsi->back->hw_csum_rx_error++;
 154 }
 155
 156 /**
 157  * ice_process_skb_fields - Populate skb header fields from Rx descriptor
 158  * @rx_ring: Rx descriptor ring packet is being transacted on
 159  * @rx_desc: pointer to the EOP Rx descriptor
 160  * @skb: pointer to current skb being populated
 161  * @ptype: the packet type decoded by hardware
 162  *
 163  * This function checks the ring, descriptor, and packet information in
 164  * order to populate the hash, checksum, VLAN, protocol, and
 165  * other fields within the skb.
 166  */
 167 void
 168 ice_process_skb_fields(struct ice_ring *rx_ring,
 169                        union ice_32b_rx_flex_desc *rx_desc,
 170                        struct sk_buff *skb, u8 ptype)
 171 {
 172         ice_rx_hash(rx_ring, rx_desc, skb, ptype);
 173
 174         /* modifies the skb - consumes the enet header */
 175         skb->protocol = eth_type_trans(skb, rx_ring->netdev);
 176
 177         ice_rx_csum(rx_ring, skb, rx_desc, ptype);
 178 }
 179
 180 /**
 181  * ice_receive_skb - Send a completed packet up the stack
 182  * @rx_ring: Rx ring in play
 183  * @skb: packet to send up
 184  * @vlan_tag: VLAN tag for packet
 185  *
 186  * This function sends the completed packet (via. skb) up the stack using
 187  * gro receive functions (with/without VLAN tag)
 188  */
 189 void
 190 ice_receive_skb(struct ice_ring *rx_ring, struct sk_buff *skb, u16 vlan_tag)
 191 {
 192         if ((rx_ring->netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
 193             (vlan_tag & VLAN_VID_MASK))
 194                 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
 195         napi_gro_receive(&rx_ring->q_vector->napi, skb);
 196 }
 197
 198 /**
 199  * ice_xmit_xdp_ring - submit single packet to XDP ring for transmission
 200  * @data: packet data pointer
 201  * @size: packet data size
 202  * @xdp_ring: XDP ring for transmission
 203  */
 204 int ice_xmit_xdp_ring(void *data, u16 size, struct ice_ring *xdp_ring)
 205 {
 206         u16 i = xdp_ring->next_to_use;
 207         struct ice_tx_desc *tx_desc;
 208         struct ice_tx_buf *tx_buf;
 209         dma_addr_t dma;
 210
 211         if (!unlikely(ICE_DESC_UNUSED(xdp_ring))) {
 212                 xdp_ring->tx_stats.tx_busy++;
 213                 return ICE_XDP_CONSUMED;
 214         }
 215
 216         dma = dma_map_single(xdp_ring->dev, data, size, DMA_TO_DEVICE);
 217         if (dma_mapping_error(xdp_ring->dev, dma))
 218                 return ICE_XDP_CONSUMED;
 219
 220         tx_buf = &xdp_ring->tx_buf[i];
 221         tx_buf->bytecount = size;
 222         tx_buf->gso_segs = 1;
 223         tx_buf->raw_buf = data;
 224
 225         /* record length, and DMA address */
 226         dma_unmap_len_set(tx_buf, len, size);
 227         dma_unmap_addr_set(tx_buf, dma, dma);
 228
 229         tx_desc = ICE_TX_DESC(xdp_ring, i);
 230         tx_desc->buf_addr = cpu_to_le64(dma);
 231         tx_desc->cmd_type_offset_bsz = ice_build_ctob(ICE_TXD_LAST_DESC_CMD, 0,
 232                                                       size, 0);
 233
 234         /* Make certain all of the status bits have been updated
 235          * before next_to_watch is written.
 236          */
 237         smp_wmb();
 238
 239         i++;
 240         if (i == xdp_ring->count)
 241                 i = 0;
 242
 243         tx_buf->next_to_watch = tx_desc;
 244         xdp_ring->next_to_use = i;
 245
 246         return ICE_XDP_TX;
 247 }
 248
 249 /**
 250  * ice_xmit_xdp_buff - convert an XDP buffer to an XDP frame and send it
 251  * @xdp: XDP buffer
 252  * @xdp_ring: XDP Tx ring
 253  *
 254  * Returns negative on failure, 0 on success.
 255  */
 256 int ice_xmit_xdp_buff(struct xdp_buff *xdp, struct ice_ring *xdp_ring)
 257 {
 258         struct xdp_frame *xdpf = xdp_convert_buff_to_frame(xdp);
 259
 260         if (unlikely(!xdpf))
 261                 return ICE_XDP_CONSUMED;
 262
 263         return ice_xmit_xdp_ring(xdpf->data, xdpf->len, xdp_ring);
 264 }
 265
 266 /**
 267  * ice_finalize_xdp_rx - Bump XDP Tx tail and/or flush redirect map
 268  * @rx_ring: Rx ring
 269  * @xdp_res: Result of the receive batch
 270  *
 271  * This function bumps XDP Tx tail and/or flush redirect map, and
 272  * should be called when a batch of packets has been processed in the
 273  * napi loop.
 274  */
 275 void ice_finalize_xdp_rx(struct ice_ring *rx_ring, unsigned int xdp_res)
 276 {
 277         if (xdp_res & ICE_XDP_REDIR)
 278                 xdp_do_flush_map();
 279
 280         if (xdp_res & ICE_XDP_TX) {
 281                 struct ice_ring *xdp_ring =
 282                         rx_ring->vsi->xdp_rings[rx_ring->q_index];
 283
 284                 ice_xdp_ring_update_tail(xdp_ring);
 285         }
 286 }