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 appropriate hash type (such as PKT_HASH_TYPE_L2/L3/L4) to be used by
  42  * skb_set_hash based on PTYPE as parsed by HW Rx pipeline and is part of
  43  * Rx desc.
  44  */
  45 static enum pkt_hash_types ice_ptype_to_htype(u16 ptype)
  46 {
  47         struct ice_rx_ptype_decoded decoded = ice_decode_rx_desc_ptype(ptype);
  48
  49         if (!decoded.known)
  50                 return PKT_HASH_TYPE_NONE;
  51         if (decoded.payload_layer == ICE_RX_PTYPE_PAYLOAD_LAYER_PAY4)
  52                 return PKT_HASH_TYPE_L4;
  53         if (decoded.payload_layer == ICE_RX_PTYPE_PAYLOAD_LAYER_PAY3)
  54                 return PKT_HASH_TYPE_L3;
  55         if (decoded.outer_ip == ICE_RX_PTYPE_OUTER_L2)
  56                 return PKT_HASH_TYPE_L2;
  57
  58         return PKT_HASH_TYPE_NONE;
  59 }
  60
  61 /**
  62  * ice_rx_hash - set the hash value in the skb
  63  * @rx_ring: descriptor ring
  64  * @rx_desc: specific descriptor
  65  * @skb: pointer to current skb
  66  * @rx_ptype: the ptype value from the descriptor
  67  */
  68 static void
  69 ice_rx_hash(struct ice_ring *rx_ring, union ice_32b_rx_flex_desc *rx_desc,
  70             struct sk_buff *skb, u16 rx_ptype)
  71 {
  72         struct ice_32b_rx_flex_desc_nic *nic_mdid;
  73         u32 hash;
  74
  75         if (!(rx_ring->netdev->features & NETIF_F_RXHASH))
  76                 return;
  77
  78         if (rx_desc->wb.rxdid != ICE_RXDID_FLEX_NIC)
  79                 return;
  80
  81         nic_mdid = (struct ice_32b_rx_flex_desc_nic *)rx_desc;
  82         hash = le32_to_cpu(nic_mdid->rss_hash);
  83         skb_set_hash(skb, hash, ice_ptype_to_htype(rx_ptype));
  84 }
  85
  86 /**
  87  * ice_rx_csum - Indicate in skb if checksum is good
  88  * @ring: the ring we care about
  89  * @skb: skb currently being received and modified
  90  * @rx_desc: the receive descriptor
  91  * @ptype: the packet type decoded by hardware
  92  *
  93  * skb->protocol must be set before this function is called
  94  */
  95 static void
  96 ice_rx_csum(struct ice_ring *ring, struct sk_buff *skb,
  97             union ice_32b_rx_flex_desc *rx_desc, u16 ptype)
  98 {
  99         struct ice_rx_ptype_decoded decoded;
 100         u16 rx_status0, rx_status1;
 101         bool ipv4, ipv6;
 102
 103         rx_status0 = le16_to_cpu(rx_desc->wb.status_error0);
 104         rx_status1 = le16_to_cpu(rx_desc->wb.status_error1);
 105
 106         decoded = ice_decode_rx_desc_ptype(ptype);
 107
 108         /* Start with CHECKSUM_NONE and by default csum_level = 0 */
 109         skb->ip_summed = CHECKSUM_NONE;
 110         skb_checksum_none_assert(skb);
 111
 112         /* check if Rx checksum is enabled */
 113         if (!(ring->netdev->features & NETIF_F_RXCSUM))
 114                 return;
 115
 116         /* check if HW has decoded the packet and checksum */
 117         if (!(rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_L3L4P_S)))
 118                 return;
 119
 120         if (!(decoded.known && decoded.outer_ip))
 121                 return;
 122
 123         ipv4 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
 124                (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV4);
 125         ipv6 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
 126                (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV6);
 127
 128         if (ipv4 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_IPE_S) |
 129                                    BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EIPE_S))))
 130                 goto checksum_fail;
 131
 132         if (ipv6 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_IPV6EXADD_S))))
 133                 goto checksum_fail;
 134
 135         /* check for L4 errors and handle packets that were not able to be
 136          * checksummed due to arrival speed
 137          */
 138         if (rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_L4E_S))
 139                 goto checksum_fail;
 140
 141         /* check for outer UDP checksum error in tunneled packets */
 142         if ((rx_status1 & BIT(ICE_RX_FLEX_DESC_STATUS1_NAT_S)) &&
 143             (rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EUDPE_S)))
 144                 goto checksum_fail;
 145
 146         /* If there is an outer header present that might contain a checksum
 147          * we need to bump the checksum level by 1 to reflect the fact that
 148          * we are indicating we validated the inner checksum.
 149          */
 150         if (decoded.tunnel_type >= ICE_RX_PTYPE_TUNNEL_IP_GRENAT)
 151                 skb->csum_level = 1;
 152
 153         /* Only report checksum unnecessary for TCP, UDP, or SCTP */
 154         switch (decoded.inner_prot) {
 155         case ICE_RX_PTYPE_INNER_PROT_TCP:
 156         case ICE_RX_PTYPE_INNER_PROT_UDP:
 157         case ICE_RX_PTYPE_INNER_PROT_SCTP:
 158                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 159                 break;
 160         default:
 161                 break;
 162         }
 163         return;
 164
 165 checksum_fail:
 166         ring->vsi->back->hw_csum_rx_error++;
 167 }
 168
 169 /**
 170  * ice_process_skb_fields - Populate skb header fields from Rx descriptor
 171  * @rx_ring: Rx descriptor ring packet is being transacted on
 172  * @rx_desc: pointer to the EOP Rx descriptor
 173  * @skb: pointer to current skb being populated
 174  * @ptype: the packet type decoded by hardware
 175  *
 176  * This function checks the ring, descriptor, and packet information in
 177  * order to populate the hash, checksum, VLAN, protocol, and
 178  * other fields within the skb.
 179  */
 180 void
 181 ice_process_skb_fields(struct ice_ring *rx_ring,
 182                        union ice_32b_rx_flex_desc *rx_desc,
 183                        struct sk_buff *skb, u16 ptype)
 184 {
 185         ice_rx_hash(rx_ring, rx_desc, skb, ptype);
 186
 187         /* modifies the skb - consumes the enet header */
 188         skb->protocol = eth_type_trans(skb, rx_ring->netdev);
 189
 190         ice_rx_csum(rx_ring, skb, rx_desc, ptype);
 191
 192         if (rx_ring->ptp_rx)
 193                 ice_ptp_rx_hwtstamp(rx_ring, rx_desc, skb);
 194 }
 195
 196 /**
 197  * ice_receive_skb - Send a completed packet up the stack
 198  * @rx_ring: Rx ring in play
 199  * @skb: packet to send up
 200  * @vlan_tag: VLAN tag for packet
 201  *
 202  * This function sends the completed packet (via. skb) up the stack using
 203  * gro receive functions (with/without VLAN tag)
 204  */
 205 void
 206 ice_receive_skb(struct ice_ring *rx_ring, struct sk_buff *skb, u16 vlan_tag)
 207 {
 208         if ((rx_ring->netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
 209             (vlan_tag & VLAN_VID_MASK))
 210                 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
 211         napi_gro_receive(&rx_ring->q_vector->napi, skb);
 212 }
 213
 214 /**
 215  * ice_xmit_xdp_ring - submit single packet to XDP ring for transmission
 216  * @data: packet data pointer
 217  * @size: packet data size
 218  * @xdp_ring: XDP ring for transmission
 219  */
 220 int ice_xmit_xdp_ring(void *data, u16 size, struct ice_ring *xdp_ring)
 221 {
 222         u16 i = xdp_ring->next_to_use;
 223         struct ice_tx_desc *tx_desc;
 224         struct ice_tx_buf *tx_buf;
 225         dma_addr_t dma;
 226
 227         if (!unlikely(ICE_DESC_UNUSED(xdp_ring))) {
 228                 xdp_ring->tx_stats.tx_busy++;
 229                 return ICE_XDP_CONSUMED;
 230         }
 231
 232         dma = dma_map_single(xdp_ring->dev, data, size, DMA_TO_DEVICE);
 233         if (dma_mapping_error(xdp_ring->dev, dma))
 234                 return ICE_XDP_CONSUMED;
 235
 236         tx_buf = &xdp_ring->tx_buf[i];
 237         tx_buf->bytecount = size;
 238         tx_buf->gso_segs = 1;
 239         tx_buf->raw_buf = data;
 240
 241         /* record length, and DMA address */
 242         dma_unmap_len_set(tx_buf, len, size);
 243         dma_unmap_addr_set(tx_buf, dma, dma);
 244
 245         tx_desc = ICE_TX_DESC(xdp_ring, i);
 246         tx_desc->buf_addr = cpu_to_le64(dma);
 247         tx_desc->cmd_type_offset_bsz = ice_build_ctob(ICE_TXD_LAST_DESC_CMD, 0,
 248                                                       size, 0);
 249
 250         /* Make certain all of the status bits have been updated
 251          * before next_to_watch is written.
 252          */
 253         smp_wmb();
 254
 255         i++;
 256         if (i == xdp_ring->count)
 257                 i = 0;
 258
 259         tx_buf->next_to_watch = tx_desc;
 260         xdp_ring->next_to_use = i;
 261
 262         return ICE_XDP_TX;
 263 }
 264
 265 /**
 266  * ice_xmit_xdp_buff - convert an XDP buffer to an XDP frame and send it
 267  * @xdp: XDP buffer
 268  * @xdp_ring: XDP Tx ring
 269  *
 270  * Returns negative on failure, 0 on success.
 271  */
 272 int ice_xmit_xdp_buff(struct xdp_buff *xdp, struct ice_ring *xdp_ring)
 273 {
 274         struct xdp_frame *xdpf = xdp_convert_buff_to_frame(xdp);
 275
 276         if (unlikely(!xdpf))
 277                 return ICE_XDP_CONSUMED;
 278
 279         return ice_xmit_xdp_ring(xdpf->data, xdpf->len, xdp_ring);
 280 }
 281
 282 /**
 283  * ice_finalize_xdp_rx - Bump XDP Tx tail and/or flush redirect map
 284  * @rx_ring: Rx ring
 285  * @xdp_res: Result of the receive batch
 286  *
 287  * This function bumps XDP Tx tail and/or flush redirect map, and
 288  * should be called when a batch of packets has been processed in the
 289  * napi loop.
 290  */
 291 void ice_finalize_xdp_rx(struct ice_ring *rx_ring, unsigned int xdp_res)
 292 {
 293         if (xdp_res & ICE_XDP_REDIR)
 294                 xdp_do_flush_map();
 295
 296         if (xdp_res & ICE_XDP_TX) {
 297                 struct ice_ring *xdp_ring =
 298                         rx_ring->vsi->xdp_rings[rx_ring->q_index];
 299
 300                 ice_xdp_ring_update_tail(xdp_ring);
 301         }
 302 }