drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c

   1 /* Broadcom NetXtreme-C/E network driver.
   2  *
   3  * Copyright (c) 2016-2017 Broadcom Limited
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation.
   8  */
   9 #include <linux/kernel.h>
  10 #include <linux/errno.h>
  11 #include <linux/pci.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/etherdevice.h>
  14 #include <linux/if_vlan.h>
  15 #include <linux/bpf.h>
  16 #include <linux/bpf_trace.h>
  17 #include <linux/filter.h>
  18 #include "bnxt_hsi.h"
  19 #include "bnxt.h"
  20 #include "bnxt_xdp.h"
  21
  22 void bnxt_xmit_xdp(struct bnxt *bp, struct bnxt_tx_ring_info *txr,
  23                    dma_addr_t mapping, u32 len, u16 rx_prod)
  24 {
  25         struct bnxt_sw_tx_bd *tx_buf;
  26         struct tx_bd *txbd;
  27         u32 flags;
  28         u16 prod;
  29
  30         prod = txr->tx_prod;
  31         tx_buf = &txr->tx_buf_ring[prod];
  32         tx_buf->rx_prod = rx_prod;
  33
  34         txbd = &txr->tx_desc_ring[TX_RING(prod)][TX_IDX(prod)];
  35         flags = (len << TX_BD_LEN_SHIFT) | (1 << TX_BD_FLAGS_BD_CNT_SHIFT) |
  36                 TX_BD_FLAGS_PACKET_END | bnxt_lhint_arr[len >> 9];
  37         txbd->tx_bd_len_flags_type = cpu_to_le32(flags);
  38         txbd->tx_bd_opaque = prod;
  39         txbd->tx_bd_haddr = cpu_to_le64(mapping);
  40
  41         prod = NEXT_TX(prod);
  42         txr->tx_prod = prod;
  43 }
  44
  45 void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts)
  46 {
  47         struct bnxt_tx_ring_info *txr = bnapi->tx_ring;
  48         struct bnxt_rx_ring_info *rxr = bnapi->rx_ring;
  49         struct bnxt_sw_tx_bd *tx_buf;
  50         u16 tx_cons = txr->tx_cons;
  51         u16 last_tx_cons = tx_cons;
  52         u16 rx_prod;
  53         int i;
  54
  55         for (i = 0; i < nr_pkts; i++) {
  56                 last_tx_cons = tx_cons;
  57                 tx_cons = NEXT_TX(tx_cons);
  58         }
  59         txr->tx_cons = tx_cons;
  60         if (bnxt_tx_avail(bp, txr) == bp->tx_ring_size) {
  61                 rx_prod = rxr->rx_prod;
  62         } else {
  63                 tx_buf = &txr->tx_buf_ring[last_tx_cons];
  64                 rx_prod = tx_buf->rx_prod;
  65         }
  66         bnxt_db_write(bp, rxr->rx_doorbell, DB_KEY_RX | rx_prod);
  67 }
  68
  69 /* returns the following:
  70  * true    - packet consumed by XDP and new buffer is allocated.
  71  * false   - packet should be passed to the stack.
  72  */
  73 bool bnxt_rx_xdp(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, u16 cons,
  74                  struct page *page, u8 **data_ptr, unsigned int *len, u8 *event)
  75 {
  76         struct bpf_prog *xdp_prog = READ_ONCE(rxr->xdp_prog);
  77         struct bnxt_tx_ring_info *txr;
  78         struct bnxt_sw_rx_bd *rx_buf;
  79         struct pci_dev *pdev;
  80         struct xdp_buff xdp;
  81         dma_addr_t mapping;
  82         void *orig_data;
  83         u32 tx_avail;
  84         u32 offset;
  85         u32 act;
  86
  87         if (!xdp_prog)
  88                 return false;
  89
  90         pdev = bp->pdev;
  91         txr = rxr->bnapi->tx_ring;
  92         rx_buf = &rxr->rx_buf_ring[cons];
  93         offset = bp->rx_offset;
  94
  95         xdp.data_hard_start = *data_ptr - offset;
  96         xdp.data = *data_ptr;
  97         xdp_set_data_meta_invalid(&xdp);
  98         xdp.data_end = *data_ptr + *len;
  99         xdp.rxq = &rxr->xdp_rxq;
 100         orig_data = xdp.data;
 101         mapping = rx_buf->mapping - bp->rx_dma_offset;
 102
 103         dma_sync_single_for_cpu(&pdev->dev, mapping + offset, *len, bp->rx_dir);
 104
 105         rcu_read_lock();
 106         act = bpf_prog_run_xdp(xdp_prog, &xdp);
 107         rcu_read_unlock();
 108
 109         tx_avail = bnxt_tx_avail(bp, txr);
 110         /* If the tx ring is not full, we must not update the rx producer yet
 111          * because we may still be transmitting on some BDs.
 112          */
 113         if (tx_avail != bp->tx_ring_size)
 114                 *event &= ~BNXT_RX_EVENT;
 115
 116         *len = xdp.data_end - xdp.data;
 117         if (orig_data != xdp.data) {
 118                 offset = xdp.data - xdp.data_hard_start;
 119                 *data_ptr = xdp.data_hard_start + offset;
 120         }
 121         switch (act) {
 122         case XDP_PASS:
 123                 return false;
 124
 125         case XDP_TX:
 126                 if (tx_avail < 1) {
 127                         trace_xdp_exception(bp->dev, xdp_prog, act);
 128                         bnxt_reuse_rx_data(rxr, cons, page);
 129                         return true;
 130                 }
 131
 132                 *event = BNXT_TX_EVENT;
 133                 dma_sync_single_for_device(&pdev->dev, mapping + offset, *len,
 134                                            bp->rx_dir);
 135                 bnxt_xmit_xdp(bp, txr, mapping + offset, *len,
 136                               NEXT_RX(rxr->rx_prod));
 137                 bnxt_reuse_rx_data(rxr, cons, page);
 138                 return true;
 139         default:
 140                 bpf_warn_invalid_xdp_action(act);
 141                 /* Fall thru */
 142         case XDP_ABORTED:
 143                 trace_xdp_exception(bp->dev, xdp_prog, act);
 144                 /* Fall thru */
 145         case XDP_DROP:
 146                 bnxt_reuse_rx_data(rxr, cons, page);
 147                 break;
 148         }
 149         return true;
 150 }
 151
 152 /* Under rtnl_lock */
 153 static int bnxt_xdp_set(struct bnxt *bp, struct bpf_prog *prog)
 154 {
 155         struct net_device *dev = bp->dev;
 156         int tx_xdp = 0, rc, tc;
 157         struct bpf_prog *old;
 158
 159         if (prog && bp->dev->mtu > BNXT_MAX_PAGE_MODE_MTU) {
 160                 netdev_warn(dev, "MTU %d larger than largest XDP supported MTU %d.\n",
 161                             bp->dev->mtu, BNXT_MAX_PAGE_MODE_MTU);
 162                 return -EOPNOTSUPP;
 163         }
 164         if (!(bp->flags & BNXT_FLAG_SHARED_RINGS)) {
 165                 netdev_warn(dev, "ethtool rx/tx channels must be combined to support XDP.\n");
 166                 return -EOPNOTSUPP;
 167         }
 168         if (prog)
 169                 tx_xdp = bp->rx_nr_rings;
 170
 171         tc = netdev_get_num_tc(dev);
 172         if (!tc)
 173                 tc = 1;
 174         rc = bnxt_check_rings(bp, bp->tx_nr_rings_per_tc, bp->rx_nr_rings,
 175                               true, tc, tx_xdp);
 176         if (rc) {
 177                 netdev_warn(dev, "Unable to reserve enough TX rings to support XDP.\n");
 178                 return rc;
 179         }
 180         if (netif_running(dev))
 181                 bnxt_close_nic(bp, true, false);
 182
 183         old = xchg(&bp->xdp_prog, prog);
 184         if (old)
 185                 bpf_prog_put(old);
 186
 187         if (prog) {
 188                 bnxt_set_rx_skb_mode(bp, true);
 189         } else {
 190                 int rx, tx;
 191
 192                 bnxt_set_rx_skb_mode(bp, false);
 193                 bnxt_get_max_rings(bp, &rx, &tx, true);
 194                 if (rx > 1) {
 195                         bp->flags &= ~BNXT_FLAG_NO_AGG_RINGS;
 196                         bp->dev->hw_features |= NETIF_F_LRO;
 197                 }
 198         }
 199         bp->tx_nr_rings_xdp = tx_xdp;
 200         bp->tx_nr_rings = bp->tx_nr_rings_per_tc * tc + tx_xdp;
 201         bp->cp_nr_rings = max_t(int, bp->tx_nr_rings, bp->rx_nr_rings);
 202         bp->num_stat_ctxs = bp->cp_nr_rings;
 203         bnxt_set_tpa_flags(bp);
 204         bnxt_set_ring_params(bp);
 205
 206         if (netif_running(dev))
 207                 return bnxt_open_nic(bp, true, false);
 208
 209         return 0;
 210 }
 211
 212 int bnxt_xdp(struct net_device *dev, struct netdev_bpf *xdp)
 213 {
 214         struct bnxt *bp = netdev_priv(dev);
 215         int rc;
 216
 217         switch (xdp->command) {
 218         case XDP_SETUP_PROG:
 219                 rc = bnxt_xdp_set(bp, xdp->prog);
 220                 break;
 221         case XDP_QUERY_PROG:
 222                 xdp->prog_id = bp->xdp_prog ? bp->xdp_prog->aux->id : 0;
 223                 rc = 0;
 224                 break;
 225         default:
 226                 rc = -EINVAL;
 227                 break;
 228         }
 229         return rc;
 230 }