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 <linux/filter.h>
   5
   6 #include "ice_txrx_lib.h"
   7 #include "ice_eswitch.h"
   8 #include "ice_lib.h"
   9
  10 /**
  11  * ice_release_rx_desc - Store the new tail and head values
  12  * @rx_ring: ring to bump
  13  * @val: new head index
  14  */
  15 void ice_release_rx_desc(struct ice_rx_ring *rx_ring, u16 val)
  16 {
  17         u16 prev_ntu = rx_ring->next_to_use & ~0x7;
  18
  19         rx_ring->next_to_use = val;
  20
  21         /* update next to alloc since we have filled the ring */
  22         rx_ring->next_to_alloc = val;
  23
  24         /* QRX_TAIL will be updated with any tail value, but hardware ignores
  25          * the lower 3 bits. This makes it so we only bump tail on meaningful
  26          * boundaries. Also, this allows us to bump tail on intervals of 8 up to
  27          * the budget depending on the current traffic load.
  28          */
  29         val &= ~0x7;
  30         if (prev_ntu != val) {
  31                 /* Force memory writes to complete before letting h/w
  32                  * know there are new descriptors to fetch. (Only
  33                  * applicable for weak-ordered memory model archs,
  34                  * such as IA-64).
  35                  */
  36                 wmb();
  37                 writel(val, rx_ring->tail);
  38         }
  39 }
  40
  41 /**
  42  * ice_ptype_to_htype - get a hash type
  43  * @ptype: the ptype value from the descriptor
  44  *
  45  * Returns appropriate hash type (such as PKT_HASH_TYPE_L2/L3/L4) to be used by
  46  * skb_set_hash based on PTYPE as parsed by HW Rx pipeline and is part of
  47  * Rx desc.
  48  */
  49 static enum pkt_hash_types ice_ptype_to_htype(u16 ptype)
  50 {
  51         struct ice_rx_ptype_decoded decoded = ice_decode_rx_desc_ptype(ptype);
  52
  53         if (!decoded.known)
  54                 return PKT_HASH_TYPE_NONE;
  55         if (decoded.payload_layer == ICE_RX_PTYPE_PAYLOAD_LAYER_PAY4)
  56                 return PKT_HASH_TYPE_L4;
  57         if (decoded.payload_layer == ICE_RX_PTYPE_PAYLOAD_LAYER_PAY3)
  58                 return PKT_HASH_TYPE_L3;
  59         if (decoded.outer_ip == ICE_RX_PTYPE_OUTER_L2)
  60                 return PKT_HASH_TYPE_L2;
  61
  62         return PKT_HASH_TYPE_NONE;
  63 }
  64
  65 /**
  66  * ice_rx_hash - set the hash value in the skb
  67  * @rx_ring: descriptor ring
  68  * @rx_desc: specific descriptor
  69  * @skb: pointer to current skb
  70  * @rx_ptype: the ptype value from the descriptor
  71  */
  72 static void
  73 ice_rx_hash(struct ice_rx_ring *rx_ring, union ice_32b_rx_flex_desc *rx_desc,
  74             struct sk_buff *skb, u16 rx_ptype)
  75 {
  76         struct ice_32b_rx_flex_desc_nic *nic_mdid;
  77         u32 hash;
  78
  79         if (!(rx_ring->netdev->features & NETIF_F_RXHASH))
  80                 return;
  81
  82         if (rx_desc->wb.rxdid != ICE_RXDID_FLEX_NIC)
  83                 return;
  84
  85         nic_mdid = (struct ice_32b_rx_flex_desc_nic *)rx_desc;
  86         hash = le32_to_cpu(nic_mdid->rss_hash);
  87         skb_set_hash(skb, hash, ice_ptype_to_htype(rx_ptype));
  88 }
  89
  90 /**
  91  * ice_rx_csum - Indicate in skb if checksum is good
  92  * @ring: the ring we care about
  93  * @skb: skb currently being received and modified
  94  * @rx_desc: the receive descriptor
  95  * @ptype: the packet type decoded by hardware
  96  *
  97  * skb->protocol must be set before this function is called
  98  */
  99 static void
 100 ice_rx_csum(struct ice_rx_ring *ring, struct sk_buff *skb,
 101             union ice_32b_rx_flex_desc *rx_desc, u16 ptype)
 102 {
 103         struct ice_rx_ptype_decoded decoded;
 104         u16 rx_status0, rx_status1;
 105         bool ipv4, ipv6;
 106
 107         rx_status0 = le16_to_cpu(rx_desc->wb.status_error0);
 108         rx_status1 = le16_to_cpu(rx_desc->wb.status_error1);
 109
 110         decoded = ice_decode_rx_desc_ptype(ptype);
 111
 112         /* Start with CHECKSUM_NONE and by default csum_level = 0 */
 113         skb->ip_summed = CHECKSUM_NONE;
 114         skb_checksum_none_assert(skb);
 115
 116         /* check if Rx checksum is enabled */
 117         if (!(ring->netdev->features & NETIF_F_RXCSUM))
 118                 return;
 119
 120         /* check if HW has decoded the packet and checksum */
 121         if (!(rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_L3L4P_S)))
 122                 return;
 123
 124         if (!(decoded.known && decoded.outer_ip))
 125                 return;
 126
 127         ipv4 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
 128                (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV4);
 129         ipv6 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
 130                (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV6);
 131
 132         if (ipv4 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_IPE_S) |
 133                                    BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EIPE_S))))
 134                 goto checksum_fail;
 135
 136         if (ipv6 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_IPV6EXADD_S))))
 137                 goto checksum_fail;
 138
 139         /* check for L4 errors and handle packets that were not able to be
 140          * checksummed due to arrival speed
 141          */
 142         if (rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_L4E_S))
 143                 goto checksum_fail;
 144
 145         /* check for outer UDP checksum error in tunneled packets */
 146         if ((rx_status1 & BIT(ICE_RX_FLEX_DESC_STATUS1_NAT_S)) &&
 147             (rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EUDPE_S)))
 148                 goto checksum_fail;
 149
 150         /* If there is an outer header present that might contain a checksum
 151          * we need to bump the checksum level by 1 to reflect the fact that
 152          * we are indicating we validated the inner checksum.
 153          */
 154         if (decoded.tunnel_type >= ICE_RX_PTYPE_TUNNEL_IP_GRENAT)
 155                 skb->csum_level = 1;
 156
 157         /* Only report checksum unnecessary for TCP, UDP, or SCTP */
 158         switch (decoded.inner_prot) {
 159         case ICE_RX_PTYPE_INNER_PROT_TCP:
 160         case ICE_RX_PTYPE_INNER_PROT_UDP:
 161         case ICE_RX_PTYPE_INNER_PROT_SCTP:
 162                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 163                 break;
 164         default:
 165                 break;
 166         }
 167         return;
 168
 169 checksum_fail:
 170         ring->vsi->back->hw_csum_rx_error++;
 171 }
 172
 173 /**
 174  * ice_process_skb_fields - Populate skb header fields from Rx descriptor
 175  * @rx_ring: Rx descriptor ring packet is being transacted on
 176  * @rx_desc: pointer to the EOP Rx descriptor
 177  * @skb: pointer to current skb being populated
 178  * @ptype: the packet type decoded by hardware
 179  *
 180  * This function checks the ring, descriptor, and packet information in
 181  * order to populate the hash, checksum, VLAN, protocol, and
 182  * other fields within the skb.
 183  */
 184 void
 185 ice_process_skb_fields(struct ice_rx_ring *rx_ring,
 186                        union ice_32b_rx_flex_desc *rx_desc,
 187                        struct sk_buff *skb, u16 ptype)
 188 {
 189         ice_rx_hash(rx_ring, rx_desc, skb, ptype);
 190
 191         /* modifies the skb - consumes the enet header */
 192         skb->protocol = eth_type_trans(skb, rx_ring->netdev);
 193
 194         ice_rx_csum(rx_ring, skb, rx_desc, ptype);
 195
 196         if (rx_ring->ptp_rx)
 197                 ice_ptp_rx_hwtstamp(rx_ring, rx_desc, skb);
 198 }
 199
 200 /**
 201  * ice_receive_skb - Send a completed packet up the stack
 202  * @rx_ring: Rx ring in play
 203  * @skb: packet to send up
 204  * @vlan_tag: VLAN tag for packet
 205  *
 206  * This function sends the completed packet (via. skb) up the stack using
 207  * gro receive functions (with/without VLAN tag)
 208  */
 209 void
 210 ice_receive_skb(struct ice_rx_ring *rx_ring, struct sk_buff *skb, u16 vlan_tag)
 211 {
 212         if ((rx_ring->netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
 213             (vlan_tag & VLAN_VID_MASK))
 214                 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
 215         napi_gro_receive(&rx_ring->q_vector->napi, skb);
 216 }
 217
 218 /**
 219  * ice_clean_xdp_irq - Reclaim resources after transmit completes on XDP ring
 220  * @xdp_ring: XDP ring to clean
 221  */
 222 static void ice_clean_xdp_irq(struct ice_tx_ring *xdp_ring)
 223 {
 224         unsigned int total_bytes = 0, total_pkts = 0;
 225         u16 ntc = xdp_ring->next_to_clean;
 226         struct ice_tx_desc *next_dd_desc;
 227         u16 next_dd = xdp_ring->next_dd;
 228         struct ice_tx_buf *tx_buf;
 229         int i;
 230
 231         next_dd_desc = ICE_TX_DESC(xdp_ring, next_dd);
 232         if (!(next_dd_desc->cmd_type_offset_bsz &
 233             cpu_to_le64(ICE_TX_DESC_DTYPE_DESC_DONE)))
 234                 return;
 235
 236         for (i = 0; i < ICE_TX_THRESH; i++) {
 237                 tx_buf = &xdp_ring->tx_buf[ntc];
 238
 239                 total_bytes += tx_buf->bytecount;
 240                 /* normally tx_buf->gso_segs was taken but at this point
 241                  * it's always 1 for us
 242                  */
 243                 total_pkts++;
 244
 245                 page_frag_free(tx_buf->raw_buf);
 246                 dma_unmap_single(xdp_ring->dev, dma_unmap_addr(tx_buf, dma),
 247                                  dma_unmap_len(tx_buf, len), DMA_TO_DEVICE);
 248                 dma_unmap_len_set(tx_buf, len, 0);
 249                 tx_buf->raw_buf = NULL;
 250
 251                 ntc++;
 252                 if (ntc >= xdp_ring->count)
 253                         ntc = 0;
 254         }
 255
 256         next_dd_desc->cmd_type_offset_bsz = 0;
 257         xdp_ring->next_dd = xdp_ring->next_dd + ICE_TX_THRESH;
 258         if (xdp_ring->next_dd > xdp_ring->count)
 259                 xdp_ring->next_dd = ICE_TX_THRESH - 1;
 260         xdp_ring->next_to_clean = ntc;
 261         ice_update_tx_ring_stats(xdp_ring, total_pkts, total_bytes);
 262 }
 263
 264 /**
 265  * ice_xmit_xdp_ring - submit single packet to XDP ring for transmission
 266  * @data: packet data pointer
 267  * @size: packet data size
 268  * @xdp_ring: XDP ring for transmission
 269  */
 270 int ice_xmit_xdp_ring(void *data, u16 size, struct ice_tx_ring *xdp_ring)
 271 {
 272         u16 i = xdp_ring->next_to_use;
 273         struct ice_tx_desc *tx_desc;
 274         struct ice_tx_buf *tx_buf;
 275         dma_addr_t dma;
 276
 277         if (ICE_DESC_UNUSED(xdp_ring) < ICE_TX_THRESH)
 278                 ice_clean_xdp_irq(xdp_ring);
 279
 280         if (!unlikely(ICE_DESC_UNUSED(xdp_ring))) {
 281                 xdp_ring->tx_stats.tx_busy++;
 282                 return ICE_XDP_CONSUMED;
 283         }
 284
 285         dma = dma_map_single(xdp_ring->dev, data, size, DMA_TO_DEVICE);
 286         if (dma_mapping_error(xdp_ring->dev, dma))
 287                 return ICE_XDP_CONSUMED;
 288
 289         tx_buf = &xdp_ring->tx_buf[i];
 290         tx_buf->bytecount = size;
 291         tx_buf->gso_segs = 1;
 292         tx_buf->raw_buf = data;
 293
 294         /* record length, and DMA address */
 295         dma_unmap_len_set(tx_buf, len, size);
 296         dma_unmap_addr_set(tx_buf, dma, dma);
 297
 298         tx_desc = ICE_TX_DESC(xdp_ring, i);
 299         tx_desc->buf_addr = cpu_to_le64(dma);
 300         tx_desc->cmd_type_offset_bsz = ice_build_ctob(ICE_TX_DESC_CMD_EOP, 0,
 301                                                       size, 0);
 302
 303         i++;
 304         if (i == xdp_ring->count) {
 305                 i = 0;
 306                 tx_desc = ICE_TX_DESC(xdp_ring, xdp_ring->next_rs);
 307                 tx_desc->cmd_type_offset_bsz |=
 308                         cpu_to_le64(ICE_TX_DESC_CMD_RS << ICE_TXD_QW1_CMD_S);
 309                 xdp_ring->next_rs = ICE_TX_THRESH - 1;
 310         }
 311         xdp_ring->next_to_use = i;
 312
 313         if (i > xdp_ring->next_rs) {
 314                 tx_desc = ICE_TX_DESC(xdp_ring, xdp_ring->next_rs);
 315                 tx_desc->cmd_type_offset_bsz |=
 316                         cpu_to_le64(ICE_TX_DESC_CMD_RS << ICE_TXD_QW1_CMD_S);
 317                 xdp_ring->next_rs += ICE_TX_THRESH;
 318         }
 319
 320         return ICE_XDP_TX;
 321 }
 322
 323 /**
 324  * ice_xmit_xdp_buff - convert an XDP buffer to an XDP frame and send it
 325  * @xdp: XDP buffer
 326  * @xdp_ring: XDP Tx ring
 327  *
 328  * Returns negative on failure, 0 on success.
 329  */
 330 int ice_xmit_xdp_buff(struct xdp_buff *xdp, struct ice_tx_ring *xdp_ring)
 331 {
 332         struct xdp_frame *xdpf = xdp_convert_buff_to_frame(xdp);
 333
 334         if (unlikely(!xdpf))
 335                 return ICE_XDP_CONSUMED;
 336
 337         return ice_xmit_xdp_ring(xdpf->data, xdpf->len, xdp_ring);
 338 }
 339
 340 /**
 341  * ice_finalize_xdp_rx - Bump XDP Tx tail and/or flush redirect map
 342  * @xdp_ring: XDP ring
 343  * @xdp_res: Result of the receive batch
 344  *
 345  * This function bumps XDP Tx tail and/or flush redirect map, and
 346  * should be called when a batch of packets has been processed in the
 347  * napi loop.
 348  */
 349 void ice_finalize_xdp_rx(struct ice_tx_ring *xdp_ring, unsigned int xdp_res)
 350 {
 351         if (xdp_res & ICE_XDP_REDIR)
 352                 xdp_do_flush_map();
 353
 354         if (xdp_res & ICE_XDP_TX) {
 355                 if (static_branch_unlikely(&ice_xdp_locking_key))
 356                         spin_lock(&xdp_ring->tx_lock);
 357                 ice_xdp_ring_update_tail(xdp_ring);
 358                 if (static_branch_unlikely(&ice_xdp_locking_key))
 359                         spin_unlock(&xdp_ring->tx_lock);
 360         }
 361 }