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         netdev_features_t features = rx_ring->netdev->features;
 213         bool non_zero_vlan = !!(vlan_tag & VLAN_VID_MASK);
 214
 215         if ((features & NETIF_F_HW_VLAN_CTAG_RX) && non_zero_vlan)
 216                 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
 217         else if ((features & NETIF_F_HW_VLAN_STAG_RX) && non_zero_vlan)
 218                 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021AD), vlan_tag);
 219
 220         napi_gro_receive(&rx_ring->q_vector->napi, skb);
 221 }
 222
 223 /**
 224  * ice_clean_xdp_tx_buf - Free and unmap XDP Tx buffer
 225  * @dev: device for DMA mapping
 226  * @tx_buf: Tx buffer to clean
 227  * @bq: XDP bulk flush struct
 228  */
 229 static void
 230 ice_clean_xdp_tx_buf(struct device *dev, struct ice_tx_buf *tx_buf,
 231                      struct xdp_frame_bulk *bq)
 232 {
 233         dma_unmap_single(dev, dma_unmap_addr(tx_buf, dma),
 234                          dma_unmap_len(tx_buf, len), DMA_TO_DEVICE);
 235         dma_unmap_len_set(tx_buf, len, 0);
 236
 237         switch (tx_buf->type) {
 238         case ICE_TX_BUF_XDP_TX:
 239                 page_frag_free(tx_buf->raw_buf);
 240                 break;
 241         case ICE_TX_BUF_XDP_XMIT:
 242                 xdp_return_frame_bulk(tx_buf->xdpf, bq);
 243                 break;
 244         }
 245
 246         tx_buf->type = ICE_TX_BUF_EMPTY;
 247 }
 248
 249 /**
 250  * ice_clean_xdp_irq - Reclaim resources after transmit completes on XDP ring
 251  * @xdp_ring: XDP ring to clean
 252  */
 253 static u32 ice_clean_xdp_irq(struct ice_tx_ring *xdp_ring)
 254 {
 255         int total_bytes = 0, total_pkts = 0;
 256         struct device *dev = xdp_ring->dev;
 257         u32 ntc = xdp_ring->next_to_clean;
 258         struct ice_tx_desc *tx_desc;
 259         u32 cnt = xdp_ring->count;
 260         struct xdp_frame_bulk bq;
 261         u32 frags, xdp_tx = 0;
 262         u32 ready_frames = 0;
 263         u32 idx;
 264         u32 ret;
 265
 266         idx = xdp_ring->tx_buf[ntc].rs_idx;
 267         tx_desc = ICE_TX_DESC(xdp_ring, idx);
 268         if (tx_desc->cmd_type_offset_bsz &
 269             cpu_to_le64(ICE_TX_DESC_DTYPE_DESC_DONE)) {
 270                 if (idx >= ntc)
 271                         ready_frames = idx - ntc + 1;
 272                 else
 273                         ready_frames = idx + cnt - ntc + 1;
 274         }
 275
 276         if (unlikely(!ready_frames))
 277                 return 0;
 278         ret = ready_frames;
 279
 280         xdp_frame_bulk_init(&bq);
 281         rcu_read_lock(); /* xdp_return_frame_bulk() */
 282
 283         while (ready_frames) {
 284                 struct ice_tx_buf *tx_buf = &xdp_ring->tx_buf[ntc];
 285                 struct ice_tx_buf *head = tx_buf;
 286
 287                 /* bytecount holds size of head + frags */
 288                 total_bytes += tx_buf->bytecount;
 289                 frags = tx_buf->nr_frags;
 290                 total_pkts++;
 291                 /* count head + frags */
 292                 ready_frames -= frags + 1;
 293                 xdp_tx++;
 294
 295                 ntc++;
 296                 if (ntc == cnt)
 297                         ntc = 0;
 298
 299                 for (int i = 0; i < frags; i++) {
 300                         tx_buf = &xdp_ring->tx_buf[ntc];
 301
 302                         ice_clean_xdp_tx_buf(dev, tx_buf, &bq);
 303                         ntc++;
 304                         if (ntc == cnt)
 305                                 ntc = 0;
 306                 }
 307
 308                 ice_clean_xdp_tx_buf(dev, head, &bq);
 309         }
 310
 311         xdp_flush_frame_bulk(&bq);
 312         rcu_read_unlock();
 313
 314         tx_desc->cmd_type_offset_bsz = 0;
 315         xdp_ring->next_to_clean = ntc;
 316         xdp_ring->xdp_tx_active -= xdp_tx;
 317         ice_update_tx_ring_stats(xdp_ring, total_pkts, total_bytes);
 318
 319         return ret;
 320 }
 321
 322 /**
 323  * __ice_xmit_xdp_ring - submit frame to XDP ring for transmission
 324  * @xdp: XDP buffer to be placed onto Tx descriptors
 325  * @xdp_ring: XDP ring for transmission
 326  * @frame: whether this comes from .ndo_xdp_xmit()
 327  */
 328 int __ice_xmit_xdp_ring(struct xdp_buff *xdp, struct ice_tx_ring *xdp_ring,
 329                         bool frame)
 330 {
 331         struct skb_shared_info *sinfo = NULL;
 332         u32 size = xdp->data_end - xdp->data;
 333         struct device *dev = xdp_ring->dev;
 334         u32 ntu = xdp_ring->next_to_use;
 335         struct ice_tx_desc *tx_desc;
 336         struct ice_tx_buf *tx_head;
 337         struct ice_tx_buf *tx_buf;
 338         u32 cnt = xdp_ring->count;
 339         void *data = xdp->data;
 340         u32 nr_frags = 0;
 341         u32 free_space;
 342         u32 frag = 0;
 343
 344         free_space = ICE_DESC_UNUSED(xdp_ring);
 345         if (free_space < ICE_RING_QUARTER(xdp_ring))
 346                 free_space += ice_clean_xdp_irq(xdp_ring);
 347
 348         if (unlikely(!free_space))
 349                 goto busy;
 350
 351         if (unlikely(xdp_buff_has_frags(xdp))) {
 352                 sinfo = xdp_get_shared_info_from_buff(xdp);
 353                 nr_frags = sinfo->nr_frags;
 354                 if (free_space < nr_frags + 1)
 355                         goto busy;
 356         }
 357
 358         tx_desc = ICE_TX_DESC(xdp_ring, ntu);
 359         tx_head = &xdp_ring->tx_buf[ntu];
 360         tx_buf = tx_head;
 361
 362         for (;;) {
 363                 dma_addr_t dma;
 364
 365                 dma = dma_map_single(dev, data, size, DMA_TO_DEVICE);
 366                 if (dma_mapping_error(dev, dma))
 367                         goto dma_unmap;
 368
 369                 /* record length, and DMA address */
 370                 dma_unmap_len_set(tx_buf, len, size);
 371                 dma_unmap_addr_set(tx_buf, dma, dma);
 372
 373                 if (frame) {
 374                         tx_buf->type = ICE_TX_BUF_FRAG;
 375                 } else {
 376                         tx_buf->type = ICE_TX_BUF_XDP_TX;
 377                         tx_buf->raw_buf = data;
 378                 }
 379
 380                 tx_desc->buf_addr = cpu_to_le64(dma);
 381                 tx_desc->cmd_type_offset_bsz = ice_build_ctob(0, 0, size, 0);
 382
 383                 ntu++;
 384                 if (ntu == cnt)
 385                         ntu = 0;
 386
 387                 if (frag == nr_frags)
 388                         break;
 389
 390                 tx_desc = ICE_TX_DESC(xdp_ring, ntu);
 391                 tx_buf = &xdp_ring->tx_buf[ntu];
 392
 393                 data = skb_frag_address(&sinfo->frags[frag]);
 394                 size = skb_frag_size(&sinfo->frags[frag]);
 395                 frag++;
 396         }
 397
 398         /* store info about bytecount and frag count in first desc */
 399         tx_head->bytecount = xdp_get_buff_len(xdp);
 400         tx_head->nr_frags = nr_frags;
 401
 402         if (frame) {
 403                 tx_head->type = ICE_TX_BUF_XDP_XMIT;
 404                 tx_head->xdpf = xdp->data_hard_start;
 405         }
 406
 407         /* update last descriptor from a frame with EOP */
 408         tx_desc->cmd_type_offset_bsz |=
 409                 cpu_to_le64(ICE_TX_DESC_CMD_EOP << ICE_TXD_QW1_CMD_S);
 410
 411         xdp_ring->xdp_tx_active++;
 412         xdp_ring->next_to_use = ntu;
 413
 414         return ICE_XDP_TX;
 415
 416 dma_unmap:
 417         for (;;) {
 418                 tx_buf = &xdp_ring->tx_buf[ntu];
 419                 dma_unmap_page(dev, dma_unmap_addr(tx_buf, dma),
 420                                dma_unmap_len(tx_buf, len), DMA_TO_DEVICE);
 421                 dma_unmap_len_set(tx_buf, len, 0);
 422                 if (tx_buf == tx_head)
 423                         break;
 424
 425                 if (!ntu)
 426                         ntu += cnt;
 427                 ntu--;
 428         }
 429         return ICE_XDP_CONSUMED;
 430
 431 busy:
 432         xdp_ring->ring_stats->tx_stats.tx_busy++;
 433
 434         return ICE_XDP_CONSUMED;
 435 }
 436
 437 /**
 438  * ice_finalize_xdp_rx - Bump XDP Tx tail and/or flush redirect map
 439  * @xdp_ring: XDP ring
 440  * @xdp_res: Result of the receive batch
 441  * @first_idx: index to write from caller
 442  *
 443  * This function bumps XDP Tx tail and/or flush redirect map, and
 444  * should be called when a batch of packets has been processed in the
 445  * napi loop.
 446  */
 447 void ice_finalize_xdp_rx(struct ice_tx_ring *xdp_ring, unsigned int xdp_res,
 448                          u32 first_idx)
 449 {
 450         struct ice_tx_buf *tx_buf = &xdp_ring->tx_buf[first_idx];
 451
 452         if (xdp_res & ICE_XDP_REDIR)
 453                 xdp_do_flush();
 454
 455         if (xdp_res & ICE_XDP_TX) {
 456                 if (static_branch_unlikely(&ice_xdp_locking_key))
 457                         spin_lock(&xdp_ring->tx_lock);
 458                 /* store index of descriptor with RS bit set in the first
 459                  * ice_tx_buf of given NAPI batch
 460                  */
 461                 tx_buf->rs_idx = ice_set_rs_bit(xdp_ring);
 462                 ice_xdp_ring_update_tail(xdp_ring);
 463                 if (static_branch_unlikely(&ice_xdp_locking_key))
 464                         spin_unlock(&xdp_ring->tx_lock);
 465         }
 466 }