linux/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
<<
>>
Prefs
   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 <net/page_pool.h>
  19#include "bnxt_hsi.h"
  20#include "bnxt.h"
  21#include "bnxt_xdp.h"
  22
  23struct bnxt_sw_tx_bd *bnxt_xmit_bd(struct bnxt *bp,
  24                                   struct bnxt_tx_ring_info *txr,
  25                                   dma_addr_t mapping, u32 len)
  26{
  27        struct bnxt_sw_tx_bd *tx_buf;
  28        struct tx_bd *txbd;
  29        u32 flags;
  30        u16 prod;
  31
  32        prod = txr->tx_prod;
  33        tx_buf = &txr->tx_buf_ring[prod];
  34
  35        txbd = &txr->tx_desc_ring[TX_RING(prod)][TX_IDX(prod)];
  36        flags = (len << TX_BD_LEN_SHIFT) | (1 << TX_BD_FLAGS_BD_CNT_SHIFT) |
  37                TX_BD_FLAGS_PACKET_END | bnxt_lhint_arr[len >> 9];
  38        txbd->tx_bd_len_flags_type = cpu_to_le32(flags);
  39        txbd->tx_bd_opaque = prod;
  40        txbd->tx_bd_haddr = cpu_to_le64(mapping);
  41
  42        prod = NEXT_TX(prod);
  43        txr->tx_prod = prod;
  44        return tx_buf;
  45}
  46
  47static void __bnxt_xmit_xdp(struct bnxt *bp, struct bnxt_tx_ring_info *txr,
  48                            dma_addr_t mapping, u32 len, u16 rx_prod)
  49{
  50        struct bnxt_sw_tx_bd *tx_buf;
  51
  52        tx_buf = bnxt_xmit_bd(bp, txr, mapping, len);
  53        tx_buf->rx_prod = rx_prod;
  54        tx_buf->action = XDP_TX;
  55}
  56
  57static void __bnxt_xmit_xdp_redirect(struct bnxt *bp,
  58                                     struct bnxt_tx_ring_info *txr,
  59                                     dma_addr_t mapping, u32 len,
  60                                     struct xdp_frame *xdpf)
  61{
  62        struct bnxt_sw_tx_bd *tx_buf;
  63
  64        tx_buf = bnxt_xmit_bd(bp, txr, mapping, len);
  65        tx_buf->action = XDP_REDIRECT;
  66        tx_buf->xdpf = xdpf;
  67        dma_unmap_addr_set(tx_buf, mapping, mapping);
  68        dma_unmap_len_set(tx_buf, len, 0);
  69}
  70
  71void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts)
  72{
  73        struct bnxt_tx_ring_info *txr = bnapi->tx_ring;
  74        struct bnxt_rx_ring_info *rxr = bnapi->rx_ring;
  75        bool rx_doorbell_needed = false;
  76        struct bnxt_sw_tx_bd *tx_buf;
  77        u16 tx_cons = txr->tx_cons;
  78        u16 last_tx_cons = tx_cons;
  79        int i;
  80
  81        for (i = 0; i < nr_pkts; i++) {
  82                tx_buf = &txr->tx_buf_ring[tx_cons];
  83
  84                if (tx_buf->action == XDP_REDIRECT) {
  85                        struct pci_dev *pdev = bp->pdev;
  86
  87                        dma_unmap_single(&pdev->dev,
  88                                         dma_unmap_addr(tx_buf, mapping),
  89                                         dma_unmap_len(tx_buf, len),
  90                                         DMA_TO_DEVICE);
  91                        xdp_return_frame(tx_buf->xdpf);
  92                        tx_buf->action = 0;
  93                        tx_buf->xdpf = NULL;
  94                } else if (tx_buf->action == XDP_TX) {
  95                        rx_doorbell_needed = true;
  96                        last_tx_cons = tx_cons;
  97                }
  98                tx_cons = NEXT_TX(tx_cons);
  99        }
 100        txr->tx_cons = tx_cons;
 101        if (rx_doorbell_needed) {
 102                tx_buf = &txr->tx_buf_ring[last_tx_cons];
 103                bnxt_db_write(bp, &rxr->rx_db, tx_buf->rx_prod);
 104        }
 105}
 106
 107/* returns the following:
 108 * true    - packet consumed by XDP and new buffer is allocated.
 109 * false   - packet should be passed to the stack.
 110 */
 111bool bnxt_rx_xdp(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, u16 cons,
 112                 struct page *page, u8 **data_ptr, unsigned int *len, u8 *event)
 113{
 114        struct bpf_prog *xdp_prog = READ_ONCE(rxr->xdp_prog);
 115        struct bnxt_tx_ring_info *txr;
 116        struct bnxt_sw_rx_bd *rx_buf;
 117        struct pci_dev *pdev;
 118        struct xdp_buff xdp;
 119        dma_addr_t mapping;
 120        void *orig_data;
 121        u32 tx_avail;
 122        u32 offset;
 123        u32 act;
 124
 125        if (!xdp_prog)
 126                return false;
 127
 128        pdev = bp->pdev;
 129        rx_buf = &rxr->rx_buf_ring[cons];
 130        offset = bp->rx_offset;
 131
 132        mapping = rx_buf->mapping - bp->rx_dma_offset;
 133        dma_sync_single_for_cpu(&pdev->dev, mapping + offset, *len, bp->rx_dir);
 134
 135        txr = rxr->bnapi->tx_ring;
 136        /* BNXT_RX_PAGE_MODE(bp) when XDP enabled */
 137        xdp_init_buff(&xdp, PAGE_SIZE, &rxr->xdp_rxq);
 138        xdp_prepare_buff(&xdp, *data_ptr - offset, offset, *len, false);
 139        orig_data = xdp.data;
 140
 141        act = bpf_prog_run_xdp(xdp_prog, &xdp);
 142
 143        tx_avail = bnxt_tx_avail(bp, txr);
 144        /* If the tx ring is not full, we must not update the rx producer yet
 145         * because we may still be transmitting on some BDs.
 146         */
 147        if (tx_avail != bp->tx_ring_size)
 148                *event &= ~BNXT_RX_EVENT;
 149
 150        *len = xdp.data_end - xdp.data;
 151        if (orig_data != xdp.data) {
 152                offset = xdp.data - xdp.data_hard_start;
 153                *data_ptr = xdp.data_hard_start + offset;
 154        }
 155        switch (act) {
 156        case XDP_PASS:
 157                return false;
 158
 159        case XDP_TX:
 160                if (tx_avail < 1) {
 161                        trace_xdp_exception(bp->dev, xdp_prog, act);
 162                        bnxt_reuse_rx_data(rxr, cons, page);
 163                        return true;
 164                }
 165
 166                *event = BNXT_TX_EVENT;
 167                dma_sync_single_for_device(&pdev->dev, mapping + offset, *len,
 168                                           bp->rx_dir);
 169                __bnxt_xmit_xdp(bp, txr, mapping + offset, *len,
 170                                NEXT_RX(rxr->rx_prod));
 171                bnxt_reuse_rx_data(rxr, cons, page);
 172                return true;
 173        case XDP_REDIRECT:
 174                /* if we are calling this here then we know that the
 175                 * redirect is coming from a frame received by the
 176                 * bnxt_en driver.
 177                 */
 178                dma_unmap_page_attrs(&pdev->dev, mapping,
 179                                     PAGE_SIZE, bp->rx_dir,
 180                                     DMA_ATTR_WEAK_ORDERING);
 181
 182                /* if we are unable to allocate a new buffer, abort and reuse */
 183                if (bnxt_alloc_rx_data(bp, rxr, rxr->rx_prod, GFP_ATOMIC)) {
 184                        trace_xdp_exception(bp->dev, xdp_prog, act);
 185                        bnxt_reuse_rx_data(rxr, cons, page);
 186                        return true;
 187                }
 188
 189                if (xdp_do_redirect(bp->dev, &xdp, xdp_prog)) {
 190                        trace_xdp_exception(bp->dev, xdp_prog, act);
 191                        page_pool_recycle_direct(rxr->page_pool, page);
 192                        return true;
 193                }
 194
 195                *event |= BNXT_REDIRECT_EVENT;
 196                break;
 197        default:
 198                bpf_warn_invalid_xdp_action(act);
 199                fallthrough;
 200        case XDP_ABORTED:
 201                trace_xdp_exception(bp->dev, xdp_prog, act);
 202                fallthrough;
 203        case XDP_DROP:
 204                bnxt_reuse_rx_data(rxr, cons, page);
 205                break;
 206        }
 207        return true;
 208}
 209
 210int bnxt_xdp_xmit(struct net_device *dev, int num_frames,
 211                  struct xdp_frame **frames, u32 flags)
 212{
 213        struct bnxt *bp = netdev_priv(dev);
 214        struct bpf_prog *xdp_prog = READ_ONCE(bp->xdp_prog);
 215        struct pci_dev *pdev = bp->pdev;
 216        struct bnxt_tx_ring_info *txr;
 217        dma_addr_t mapping;
 218        int nxmit = 0;
 219        int ring;
 220        int i;
 221
 222        if (!test_bit(BNXT_STATE_OPEN, &bp->state) ||
 223            !bp->tx_nr_rings_xdp ||
 224            !xdp_prog)
 225                return -EINVAL;
 226
 227        ring = smp_processor_id() % bp->tx_nr_rings_xdp;
 228        txr = &bp->tx_ring[ring];
 229
 230        for (i = 0; i < num_frames; i++) {
 231                struct xdp_frame *xdp = frames[i];
 232
 233                if (!txr || !bnxt_tx_avail(bp, txr) ||
 234                    !(bp->bnapi[ring]->flags & BNXT_NAPI_FLAG_XDP))
 235                        break;
 236
 237                mapping = dma_map_single(&pdev->dev, xdp->data, xdp->len,
 238                                         DMA_TO_DEVICE);
 239
 240                if (dma_mapping_error(&pdev->dev, mapping))
 241                        break;
 242
 243                __bnxt_xmit_xdp_redirect(bp, txr, mapping, xdp->len, xdp);
 244                nxmit++;
 245        }
 246
 247        if (flags & XDP_XMIT_FLUSH) {
 248                /* Sync BD data before updating doorbell */
 249                wmb();
 250                bnxt_db_write(bp, &txr->tx_db, txr->tx_prod);
 251        }
 252
 253        return nxmit;
 254}
 255
 256/* Under rtnl_lock */
 257static int bnxt_xdp_set(struct bnxt *bp, struct bpf_prog *prog)
 258{
 259        struct net_device *dev = bp->dev;
 260        int tx_xdp = 0, rc, tc;
 261        struct bpf_prog *old;
 262
 263        if (prog && bp->dev->mtu > BNXT_MAX_PAGE_MODE_MTU) {
 264                netdev_warn(dev, "MTU %d larger than largest XDP supported MTU %d.\n",
 265                            bp->dev->mtu, BNXT_MAX_PAGE_MODE_MTU);
 266                return -EOPNOTSUPP;
 267        }
 268        if (!(bp->flags & BNXT_FLAG_SHARED_RINGS)) {
 269                netdev_warn(dev, "ethtool rx/tx channels must be combined to support XDP.\n");
 270                return -EOPNOTSUPP;
 271        }
 272        if (prog)
 273                tx_xdp = bp->rx_nr_rings;
 274
 275        tc = netdev_get_num_tc(dev);
 276        if (!tc)
 277                tc = 1;
 278        rc = bnxt_check_rings(bp, bp->tx_nr_rings_per_tc, bp->rx_nr_rings,
 279                              true, tc, tx_xdp);
 280        if (rc) {
 281                netdev_warn(dev, "Unable to reserve enough TX rings to support XDP.\n");
 282                return rc;
 283        }
 284        if (netif_running(dev))
 285                bnxt_close_nic(bp, true, false);
 286
 287        old = xchg(&bp->xdp_prog, prog);
 288        if (old)
 289                bpf_prog_put(old);
 290
 291        if (prog) {
 292                bnxt_set_rx_skb_mode(bp, true);
 293        } else {
 294                int rx, tx;
 295
 296                bnxt_set_rx_skb_mode(bp, false);
 297                bnxt_get_max_rings(bp, &rx, &tx, true);
 298                if (rx > 1) {
 299                        bp->flags &= ~BNXT_FLAG_NO_AGG_RINGS;
 300                        bp->dev->hw_features |= NETIF_F_LRO;
 301                }
 302        }
 303        bp->tx_nr_rings_xdp = tx_xdp;
 304        bp->tx_nr_rings = bp->tx_nr_rings_per_tc * tc + tx_xdp;
 305        bp->cp_nr_rings = max_t(int, bp->tx_nr_rings, bp->rx_nr_rings);
 306        bnxt_set_tpa_flags(bp);
 307        bnxt_set_ring_params(bp);
 308
 309        if (netif_running(dev))
 310                return bnxt_open_nic(bp, true, false);
 311
 312        return 0;
 313}
 314
 315int bnxt_xdp(struct net_device *dev, struct netdev_bpf *xdp)
 316{
 317        struct bnxt *bp = netdev_priv(dev);
 318        int rc;
 319
 320        switch (xdp->command) {
 321        case XDP_SETUP_PROG:
 322                rc = bnxt_xdp_set(bp, xdp->prog);
 323                break;
 324        default:
 325                rc = -EINVAL;
 326                break;
 327        }
 328        return rc;
 329}
 330