kernel/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c

   1 /*
   2  * Copyright (c) 2015, Mellanox Technologies. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  */
  32
  33 #include <linux/ip.h>
  34 #include <linux/ipv6.h>
  35 #include <linux/tcp.h>
  36 #include "en.h"
  37
  38 static inline int mlx5e_alloc_rx_wqe(struct mlx5e_rq *rq,
  39                                      struct mlx5e_rx_wqe *wqe, u16 ix)
  40 {
  41         struct sk_buff *skb;
  42         dma_addr_t dma_addr;
  43
  44         skb = netdev_alloc_skb(rq->netdev, rq->wqe_sz);
  45         if (unlikely(!skb))
  46                 return -ENOMEM;
  47
  48         dma_addr = dma_map_single(rq->pdev,
  49                                   /* hw start padding */
  50                                   skb->data,
  51                                   /* hw end padding */
  52                                   rq->wqe_sz,
  53                                   DMA_FROM_DEVICE);
  54
  55         if (unlikely(dma_mapping_error(rq->pdev, dma_addr)))
  56                 goto err_free_skb;
  57
  58         skb_reserve(skb, MLX5E_NET_IP_ALIGN);
  59
  60         *((dma_addr_t *)skb->cb) = dma_addr;
  61         wqe->data.addr = cpu_to_be64(dma_addr + MLX5E_NET_IP_ALIGN);
  62
  63         rq->skb[ix] = skb;
  64
  65         return 0;
  66
  67 err_free_skb:
  68         dev_kfree_skb(skb);
  69
  70         return -ENOMEM;
  71 }
  72
  73 bool mlx5e_post_rx_wqes(struct mlx5e_rq *rq)
  74 {
  75         struct mlx5_wq_ll *wq = &rq->wq;
  76
  77         if (unlikely(!test_bit(MLX5E_RQ_STATE_POST_WQES_ENABLE, &rq->state)))
  78                 return false;
  79
  80         while (!mlx5_wq_ll_is_full(wq)) {
  81                 struct mlx5e_rx_wqe *wqe = mlx5_wq_ll_get_wqe(wq, wq->head);
  82
  83                 if (unlikely(mlx5e_alloc_rx_wqe(rq, wqe, wq->head)))
  84                         break;
  85
  86                 mlx5_wq_ll_push(wq, be16_to_cpu(wqe->next.next_wqe_index));
  87         }
  88
  89         /* ensure wqes are visible to device before updating doorbell record */
  90         dma_wmb();
  91
  92         mlx5_wq_ll_update_db_record(wq);
  93
  94         return !mlx5_wq_ll_is_full(wq);
  95 }
  96
  97 static void mlx5e_lro_update_hdr(struct sk_buff *skb, struct mlx5_cqe64 *cqe)
  98 {
  99         struct ethhdr   *eth    = (struct ethhdr *)(skb->data);
 100         struct iphdr    *ipv4   = (struct iphdr *)(skb->data + ETH_HLEN);
 101         struct ipv6hdr  *ipv6   = (struct ipv6hdr *)(skb->data + ETH_HLEN);
 102         struct tcphdr   *tcp;
 103
 104         u8 l4_hdr_type = get_cqe_l4_hdr_type(cqe);
 105         int tcp_ack = ((CQE_L4_HDR_TYPE_TCP_ACK_NO_DATA  == l4_hdr_type) ||
 106                        (CQE_L4_HDR_TYPE_TCP_ACK_AND_DATA == l4_hdr_type));
 107
 108         u16 tot_len = be32_to_cpu(cqe->byte_cnt) - ETH_HLEN;
 109
 110         if (eth->h_proto == htons(ETH_P_IP)) {
 111                 tcp = (struct tcphdr *)(skb->data + ETH_HLEN +
 112                                         sizeof(struct iphdr));
 113                 ipv6 = NULL;
 114                 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 115         } else {
 116                 tcp = (struct tcphdr *)(skb->data + ETH_HLEN +
 117                                         sizeof(struct ipv6hdr));
 118                 ipv4 = NULL;
 119                 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 120         }
 121
 122         if (get_cqe_lro_tcppsh(cqe))
 123                 tcp->psh                = 1;
 124
 125         if (tcp_ack) {
 126                 tcp->ack                = 1;
 127                 tcp->ack_seq            = cqe->lro_ack_seq_num;
 128                 tcp->window             = cqe->lro_tcp_win;
 129         }
 130
 131         if (ipv4) {
 132                 ipv4->ttl               = cqe->lro_min_ttl;
 133                 ipv4->tot_len           = cpu_to_be16(tot_len);
 134                 ipv4->check             = 0;
 135                 ipv4->check             = ip_fast_csum((unsigned char *)ipv4,
 136                                                        ipv4->ihl);
 137         } else {
 138                 ipv6->hop_limit         = cqe->lro_min_ttl;
 139                 ipv6->payload_len       = cpu_to_be16(tot_len -
 140                                                       sizeof(struct ipv6hdr));
 141         }
 142 }
 143
 144 static inline void mlx5e_skb_set_hash(struct mlx5_cqe64 *cqe,
 145                                       struct sk_buff *skb)
 146 {
 147         u8 cht = cqe->rss_hash_type;
 148         int ht = (cht & CQE_RSS_HTYPE_L4) ? PKT_HASH_TYPE_L4 :
 149                  (cht & CQE_RSS_HTYPE_IP) ? PKT_HASH_TYPE_L3 :
 150                                             PKT_HASH_TYPE_NONE;
 151         skb_set_hash(skb, be32_to_cpu(cqe->rss_hash_result), ht);
 152 }
 153
 154 static inline bool is_first_ethertype_ip(struct sk_buff *skb)
 155 {
 156         __be16 ethertype = ((struct ethhdr *)skb->data)->h_proto;
 157
 158         return (ethertype == htons(ETH_P_IP) || ethertype == htons(ETH_P_IPV6));
 159 }
 160
 161 static inline void mlx5e_handle_csum(struct net_device *netdev,
 162                                      struct mlx5_cqe64 *cqe,
 163                                      struct mlx5e_rq *rq,
 164                                      struct sk_buff *skb)
 165 {
 166         if (unlikely(!(netdev->features & NETIF_F_RXCSUM)))
 167                 goto csum_none;
 168
 169         if (likely(cqe->hds_ip_ext & CQE_L4_OK)) {
 170                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 171         } else if (is_first_ethertype_ip(skb)) {
 172                 skb->ip_summed = CHECKSUM_COMPLETE;
 173                 skb->csum = csum_unfold((__force __sum16)cqe->check_sum);
 174                 rq->stats.csum_sw++;
 175         } else {
 176                 goto csum_none;
 177         }
 178
 179         return;
 180
 181 csum_none:
 182         skb->ip_summed = CHECKSUM_NONE;
 183         rq->stats.csum_none++;
 184 }
 185
 186 static inline void mlx5e_build_rx_skb(struct mlx5_cqe64 *cqe,
 187                                       struct mlx5e_rq *rq,
 188                                       struct sk_buff *skb)
 189 {
 190         struct net_device *netdev = rq->netdev;
 191         u32 cqe_bcnt = be32_to_cpu(cqe->byte_cnt);
 192         int lro_num_seg;
 193
 194         skb_put(skb, cqe_bcnt);
 195
 196         lro_num_seg = be32_to_cpu(cqe->srqn) >> 24;
 197         if (lro_num_seg > 1) {
 198                 mlx5e_lro_update_hdr(skb, cqe);
 199                 skb_shinfo(skb)->gso_size = DIV_ROUND_UP(cqe_bcnt, lro_num_seg);
 200                 rq->stats.lro_packets++;
 201                 rq->stats.lro_bytes += cqe_bcnt;
 202         }
 203
 204         mlx5e_handle_csum(netdev, cqe, rq, skb);
 205
 206         skb->protocol = eth_type_trans(skb, netdev);
 207
 208         skb_record_rx_queue(skb, rq->ix);
 209
 210         if (likely(netdev->features & NETIF_F_RXHASH))
 211                 mlx5e_skb_set_hash(cqe, skb);
 212
 213         if (cqe_has_vlan(cqe))
 214                 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
 215                                        be16_to_cpu(cqe->vlan_info));
 216 }
 217
 218 bool mlx5e_poll_rx_cq(struct mlx5e_cq *cq, int budget)
 219 {
 220         struct mlx5e_rq *rq = container_of(cq, struct mlx5e_rq, cq);
 221         int i;
 222
 223         /* avoid accessing cq (dma coherent memory) if not needed */
 224         if (!test_and_clear_bit(MLX5E_CQ_HAS_CQES, &cq->flags))
 225                 return false;
 226
 227         for (i = 0; i < budget; i++) {
 228                 struct mlx5e_rx_wqe *wqe;
 229                 struct mlx5_cqe64 *cqe;
 230                 struct sk_buff *skb;
 231                 __be16 wqe_counter_be;
 232                 u16 wqe_counter;
 233
 234                 cqe = mlx5e_get_cqe(cq);
 235                 if (!cqe)
 236                         break;
 237
 238                 mlx5_cqwq_pop(&cq->wq);
 239
 240                 wqe_counter_be = cqe->wqe_counter;
 241                 wqe_counter    = be16_to_cpu(wqe_counter_be);
 242                 wqe            = mlx5_wq_ll_get_wqe(&rq->wq, wqe_counter);
 243                 skb            = rq->skb[wqe_counter];
 244                 prefetch(skb->data);
 245                 rq->skb[wqe_counter] = NULL;
 246
 247                 dma_unmap_single(rq->pdev,
 248                                  *((dma_addr_t *)skb->cb),
 249                                  rq->wqe_sz,
 250                                  DMA_FROM_DEVICE);
 251
 252                 if (unlikely((cqe->op_own >> 4) != MLX5_CQE_RESP_SEND)) {
 253                         rq->stats.wqe_err++;
 254                         dev_kfree_skb(skb);
 255                         goto wq_ll_pop;
 256                 }
 257
 258                 mlx5e_build_rx_skb(cqe, rq, skb);
 259                 rq->stats.packets++;
 260                 napi_gro_receive(cq->napi, skb);
 261
 262 wq_ll_pop:
 263                 mlx5_wq_ll_pop(&rq->wq, wqe_counter_be,
 264                                &wqe->next.next_wqe_index);
 265         }
 266
 267         mlx5_cqwq_update_db_record(&cq->wq);
 268
 269         /* ensure cq space is freed before enabling more cqes */
 270         wmb();
 271
 272         if (i == budget) {
 273                 set_bit(MLX5E_CQ_HAS_CQES, &cq->flags);
 274                 return true;
 275         }
 276
 277         return false;
 278 }