drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c

   1 /*
   2  * Copyright (c) 2018, 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/bpf_trace.h>
  34 #include "en/xdp.h"
  35
  36 static inline bool
  37 mlx5e_xmit_xdp_buff(struct mlx5e_xdpsq *sq, struct mlx5e_dma_info *di,
  38                     struct xdp_buff *xdp)
  39 {
  40         struct mlx5e_xdp_info xdpi;
  41
  42         xdpi.xdpf = convert_to_xdp_frame(xdp);
  43         if (unlikely(!xdpi.xdpf))
  44                 return false;
  45         xdpi.dma_addr = di->addr + (xdpi.xdpf->data - (void *)xdpi.xdpf);
  46         dma_sync_single_for_device(sq->pdev, xdpi.dma_addr,
  47                                    xdpi.xdpf->len, PCI_DMA_TODEVICE);
  48         xdpi.di = *di;
  49
  50         return mlx5e_xmit_xdp_frame(sq, &xdpi);
  51 }
  52
  53 /* returns true if packet was consumed by xdp */
  54 bool mlx5e_xdp_handle(struct mlx5e_rq *rq, struct mlx5e_dma_info *di,
  55                       void *va, u16 *rx_headroom, u32 *len)
  56 {
  57         struct bpf_prog *prog = READ_ONCE(rq->xdp_prog);
  58         struct xdp_buff xdp;
  59         u32 act;
  60         int err;
  61
  62         if (!prog)
  63                 return false;
  64
  65         xdp.data = va + *rx_headroom;
  66         xdp_set_data_meta_invalid(&xdp);
  67         xdp.data_end = xdp.data + *len;
  68         xdp.data_hard_start = va;
  69         xdp.rxq = &rq->xdp_rxq;
  70
  71         act = bpf_prog_run_xdp(prog, &xdp);
  72         switch (act) {
  73         case XDP_PASS:
  74                 *rx_headroom = xdp.data - xdp.data_hard_start;
  75                 *len = xdp.data_end - xdp.data;
  76                 return false;
  77         case XDP_TX:
  78                 if (unlikely(!mlx5e_xmit_xdp_buff(&rq->xdpsq, di, &xdp)))
  79                         goto xdp_abort;
  80                 __set_bit(MLX5E_RQ_FLAG_XDP_XMIT, rq->flags); /* non-atomic */
  81                 return true;
  82         case XDP_REDIRECT:
  83                 /* When XDP enabled then page-refcnt==1 here */
  84                 err = xdp_do_redirect(rq->netdev, &xdp, prog);
  85                 if (unlikely(err))
  86                         goto xdp_abort;
  87                 __set_bit(MLX5E_RQ_FLAG_XDP_XMIT, rq->flags);
  88                 rq->xdpsq.redirect_flush = true;
  89                 mlx5e_page_dma_unmap(rq, di);
  90                 rq->stats->xdp_redirect++;
  91                 return true;
  92         default:
  93                 bpf_warn_invalid_xdp_action(act);
  94                 /* fall through */
  95         case XDP_ABORTED:
  96 xdp_abort:
  97                 trace_xdp_exception(rq->netdev, prog, act);
  98                 /* fall through */
  99         case XDP_DROP:
 100                 rq->stats->xdp_drop++;
 101                 return true;
 102         }
 103 }
 104
 105 bool mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq, struct mlx5e_xdp_info *xdpi)
 106 {
 107         struct mlx5_wq_cyc       *wq   = &sq->wq;
 108         u16                       pi   = mlx5_wq_cyc_ctr2ix(wq, sq->pc);
 109         struct mlx5e_tx_wqe      *wqe  = mlx5_wq_cyc_get_wqe(wq, pi);
 110
 111         struct mlx5_wqe_ctrl_seg *cseg = &wqe->ctrl;
 112         struct mlx5_wqe_eth_seg  *eseg = &wqe->eth;
 113         struct mlx5_wqe_data_seg *dseg = wqe->data;
 114
 115         struct xdp_frame *xdpf = xdpi->xdpf;
 116         dma_addr_t dma_addr  = xdpi->dma_addr;
 117         unsigned int dma_len = xdpf->len;
 118
 119         struct mlx5e_xdpsq_stats *stats = sq->stats;
 120
 121         prefetchw(wqe);
 122
 123         if (unlikely(dma_len < MLX5E_XDP_MIN_INLINE || sq->hw_mtu < dma_len)) {
 124                 stats->err++;
 125                 return false;
 126         }
 127
 128         if (unlikely(!mlx5e_wqc_has_room_for(wq, sq->cc, sq->pc, 1))) {
 129                 if (sq->doorbell) {
 130                         /* SQ is full, ring doorbell */
 131                         mlx5e_xmit_xdp_doorbell(sq);
 132                         sq->doorbell = false;
 133                 }
 134                 stats->full++;
 135                 return false;
 136         }
 137
 138         cseg->fm_ce_se = 0;
 139
 140         /* copy the inline part if required */
 141         if (sq->min_inline_mode != MLX5_INLINE_MODE_NONE) {
 142                 memcpy(eseg->inline_hdr.start, xdpf->data, MLX5E_XDP_MIN_INLINE);
 143                 eseg->inline_hdr.sz = cpu_to_be16(MLX5E_XDP_MIN_INLINE);
 144                 dma_len  -= MLX5E_XDP_MIN_INLINE;
 145                 dma_addr += MLX5E_XDP_MIN_INLINE;
 146                 dseg++;
 147         }
 148
 149         /* write the dma part */
 150         dseg->addr       = cpu_to_be64(dma_addr);
 151         dseg->byte_count = cpu_to_be32(dma_len);
 152
 153         cseg->opmod_idx_opcode = cpu_to_be32((sq->pc << 8) | MLX5_OPCODE_SEND);
 154
 155         /* move page to reference to sq responsibility,
 156          * and mark so it's not put back in page-cache.
 157          */
 158         sq->db.xdpi[pi] = *xdpi;
 159         sq->pc++;
 160
 161         sq->doorbell = true;
 162
 163         stats->xmit++;
 164         return true;
 165 }
 166
 167 bool mlx5e_poll_xdpsq_cq(struct mlx5e_cq *cq, struct mlx5e_rq *rq)
 168 {
 169         struct mlx5e_xdpsq *sq;
 170         struct mlx5_cqe64 *cqe;
 171         bool is_redirect;
 172         u16 sqcc;
 173         int i;
 174
 175         sq = container_of(cq, struct mlx5e_xdpsq, cq);
 176
 177         if (unlikely(!test_bit(MLX5E_SQ_STATE_ENABLED, &sq->state)))
 178                 return false;
 179
 180         cqe = mlx5_cqwq_get_cqe(&cq->wq);
 181         if (!cqe)
 182                 return false;
 183
 184         is_redirect = !rq;
 185
 186         /* sq->cc must be updated only after mlx5_cqwq_update_db_record(),
 187          * otherwise a cq overrun may occur
 188          */
 189         sqcc = sq->cc;
 190
 191         i = 0;
 192         do {
 193                 u16 wqe_counter;
 194                 bool last_wqe;
 195
 196                 mlx5_cqwq_pop(&cq->wq);
 197
 198                 wqe_counter = be16_to_cpu(cqe->wqe_counter);
 199
 200                 do {
 201                         u16 ci = mlx5_wq_cyc_ctr2ix(&sq->wq, sqcc);
 202                         struct mlx5e_xdp_info *xdpi = &sq->db.xdpi[ci];
 203
 204                         last_wqe = (sqcc == wqe_counter);
 205                         sqcc++;
 206
 207                         if (is_redirect) {
 208                                 xdp_return_frame(xdpi->xdpf);
 209                                 dma_unmap_single(sq->pdev, xdpi->dma_addr,
 210                                                  xdpi->xdpf->len, DMA_TO_DEVICE);
 211                         } else {
 212                                 /* Recycle RX page */
 213                                 mlx5e_page_release(rq, &xdpi->di, true);
 214                         }
 215                 } while (!last_wqe);
 216         } while ((++i < MLX5E_TX_CQ_POLL_BUDGET) && (cqe = mlx5_cqwq_get_cqe(&cq->wq)));
 217
 218         sq->stats->cqes += i;
 219
 220         mlx5_cqwq_update_db_record(&cq->wq);
 221
 222         /* ensure cq space is freed before enabling more cqes */
 223         wmb();
 224
 225         sq->cc = sqcc;
 226         return (i == MLX5E_TX_CQ_POLL_BUDGET);
 227 }
 228
 229 void mlx5e_free_xdpsq_descs(struct mlx5e_xdpsq *sq, struct mlx5e_rq *rq)
 230 {
 231         bool is_redirect = !rq;
 232
 233         while (sq->cc != sq->pc) {
 234                 u16 ci = mlx5_wq_cyc_ctr2ix(&sq->wq, sq->cc);
 235                 struct mlx5e_xdp_info *xdpi = &sq->db.xdpi[ci];
 236
 237                 sq->cc++;
 238
 239                 if (is_redirect) {
 240                         xdp_return_frame(xdpi->xdpf);
 241                         dma_unmap_single(sq->pdev, xdpi->dma_addr,
 242                                          xdpi->xdpf->len, DMA_TO_DEVICE);
 243                 } else {
 244                         /* Recycle RX page */
 245                         mlx5e_page_release(rq, &xdpi->di, false);
 246                 }
 247         }
 248 }
 249
 250 int mlx5e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
 251                    u32 flags)
 252 {
 253         struct mlx5e_priv *priv = netdev_priv(dev);
 254         struct mlx5e_xdpsq *sq;
 255         int drops = 0;
 256         int sq_num;
 257         int i;
 258
 259         if (unlikely(!test_bit(MLX5E_STATE_OPENED, &priv->state)))
 260                 return -ENETDOWN;
 261
 262         if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
 263                 return -EINVAL;
 264
 265         sq_num = smp_processor_id();
 266
 267         if (unlikely(sq_num >= priv->channels.num))
 268                 return -ENXIO;
 269
 270         sq = &priv->channels.c[sq_num]->xdpsq;
 271
 272         if (unlikely(!test_bit(MLX5E_SQ_STATE_ENABLED, &sq->state)))
 273                 return -ENETDOWN;
 274
 275         for (i = 0; i < n; i++) {
 276                 struct xdp_frame *xdpf = frames[i];
 277                 struct mlx5e_xdp_info xdpi;
 278
 279                 xdpi.dma_addr = dma_map_single(sq->pdev, xdpf->data, xdpf->len,
 280                                                DMA_TO_DEVICE);
 281                 if (unlikely(dma_mapping_error(sq->pdev, xdpi.dma_addr))) {
 282                         xdp_return_frame_rx_napi(xdpf);
 283                         drops++;
 284                         continue;
 285                 }
 286
 287                 xdpi.xdpf = xdpf;
 288
 289                 if (unlikely(!mlx5e_xmit_xdp_frame(sq, &xdpi))) {
 290                         dma_unmap_single(sq->pdev, xdpi.dma_addr,
 291                                          xdpf->len, DMA_TO_DEVICE);
 292                         xdp_return_frame_rx_napi(xdpf);
 293                         drops++;
 294                 }
 295         }
 296
 297         if (flags & XDP_XMIT_FLUSH)
 298                 mlx5e_xmit_xdp_doorbell(sq);
 299
 300         return n - drops;
 301 }
 302
 303 void mlx5e_xdp_rx_poll_complete(struct mlx5e_rq *rq)
 304 {
 305         struct mlx5e_xdpsq *xdpsq = &rq->xdpsq;
 306
 307         if (xdpsq->doorbell) {
 308                 mlx5e_xmit_xdp_doorbell(xdpsq);
 309                 xdpsq->doorbell = false;
 310         }
 311
 312         if (xdpsq->redirect_flush) {
 313                 xdp_do_flush_map();
 314                 xdpsq->redirect_flush = false;
 315         }
 316 }