linux/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/* Copyright(c) 2018 Intel Corporation. */
   3
   4#include <linux/bpf_trace.h>
   5#include <net/xdp_sock_drv.h>
   6#include <net/xdp.h>
   7
   8#include "ixgbe.h"
   9#include "ixgbe_txrx_common.h"
  10
  11struct xsk_buff_pool *ixgbe_xsk_pool(struct ixgbe_adapter *adapter,
  12                                     struct ixgbe_ring *ring)
  13{
  14        bool xdp_on = READ_ONCE(adapter->xdp_prog);
  15        int qid = ring->ring_idx;
  16
  17        if (!xdp_on || !test_bit(qid, adapter->af_xdp_zc_qps))
  18                return NULL;
  19
  20        return xsk_get_pool_from_qid(adapter->netdev, qid);
  21}
  22
  23static int ixgbe_xsk_pool_enable(struct ixgbe_adapter *adapter,
  24                                 struct xsk_buff_pool *pool,
  25                                 u16 qid)
  26{
  27        struct net_device *netdev = adapter->netdev;
  28        bool if_running;
  29        int err;
  30
  31        if (qid >= adapter->num_rx_queues)
  32                return -EINVAL;
  33
  34        if (qid >= netdev->real_num_rx_queues ||
  35            qid >= netdev->real_num_tx_queues)
  36                return -EINVAL;
  37
  38        err = xsk_pool_dma_map(pool, &adapter->pdev->dev, IXGBE_RX_DMA_ATTR);
  39        if (err)
  40                return err;
  41
  42        if_running = netif_running(adapter->netdev) &&
  43                     ixgbe_enabled_xdp_adapter(adapter);
  44
  45        if (if_running)
  46                ixgbe_txrx_ring_disable(adapter, qid);
  47
  48        set_bit(qid, adapter->af_xdp_zc_qps);
  49
  50        if (if_running) {
  51                ixgbe_txrx_ring_enable(adapter, qid);
  52
  53                /* Kick start the NAPI context so that receiving will start */
  54                err = ixgbe_xsk_wakeup(adapter->netdev, qid, XDP_WAKEUP_RX);
  55                if (err) {
  56                        clear_bit(qid, adapter->af_xdp_zc_qps);
  57                        xsk_pool_dma_unmap(pool, IXGBE_RX_DMA_ATTR);
  58                        return err;
  59                }
  60        }
  61
  62        return 0;
  63}
  64
  65static int ixgbe_xsk_pool_disable(struct ixgbe_adapter *adapter, u16 qid)
  66{
  67        struct xsk_buff_pool *pool;
  68        bool if_running;
  69
  70        pool = xsk_get_pool_from_qid(adapter->netdev, qid);
  71        if (!pool)
  72                return -EINVAL;
  73
  74        if_running = netif_running(adapter->netdev) &&
  75                     ixgbe_enabled_xdp_adapter(adapter);
  76
  77        if (if_running)
  78                ixgbe_txrx_ring_disable(adapter, qid);
  79
  80        clear_bit(qid, adapter->af_xdp_zc_qps);
  81        xsk_pool_dma_unmap(pool, IXGBE_RX_DMA_ATTR);
  82
  83        if (if_running)
  84                ixgbe_txrx_ring_enable(adapter, qid);
  85
  86        return 0;
  87}
  88
  89int ixgbe_xsk_pool_setup(struct ixgbe_adapter *adapter,
  90                         struct xsk_buff_pool *pool,
  91                         u16 qid)
  92{
  93        return pool ? ixgbe_xsk_pool_enable(adapter, pool, qid) :
  94                ixgbe_xsk_pool_disable(adapter, qid);
  95}
  96
  97static int ixgbe_run_xdp_zc(struct ixgbe_adapter *adapter,
  98                            struct ixgbe_ring *rx_ring,
  99                            struct xdp_buff *xdp)
 100{
 101        int err, result = IXGBE_XDP_PASS;
 102        struct bpf_prog *xdp_prog;
 103        struct ixgbe_ring *ring;
 104        struct xdp_frame *xdpf;
 105        u32 act;
 106
 107        xdp_prog = READ_ONCE(rx_ring->xdp_prog);
 108        act = bpf_prog_run_xdp(xdp_prog, xdp);
 109
 110        if (likely(act == XDP_REDIRECT)) {
 111                err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
 112                if (!err)
 113                        return IXGBE_XDP_REDIR;
 114                if (xsk_uses_need_wakeup(rx_ring->xsk_pool) && err == -ENOBUFS)
 115                        result = IXGBE_XDP_EXIT;
 116                else
 117                        result = IXGBE_XDP_CONSUMED;
 118                goto out_failure;
 119        }
 120
 121        switch (act) {
 122        case XDP_PASS:
 123                break;
 124        case XDP_TX:
 125                xdpf = xdp_convert_buff_to_frame(xdp);
 126                if (unlikely(!xdpf))
 127                        goto out_failure;
 128                ring = ixgbe_determine_xdp_ring(adapter);
 129                if (static_branch_unlikely(&ixgbe_xdp_locking_key))
 130                        spin_lock(&ring->tx_lock);
 131                result = ixgbe_xmit_xdp_ring(ring, xdpf);
 132                if (static_branch_unlikely(&ixgbe_xdp_locking_key))
 133                        spin_unlock(&ring->tx_lock);
 134                if (result == IXGBE_XDP_CONSUMED)
 135                        goto out_failure;
 136                break;
 137        case XDP_DROP:
 138                result = IXGBE_XDP_CONSUMED;
 139                break;
 140        default:
 141                bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, act);
 142                fallthrough;
 143        case XDP_ABORTED:
 144                result = IXGBE_XDP_CONSUMED;
 145out_failure:
 146                trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
 147        }
 148        return result;
 149}
 150
 151bool ixgbe_alloc_rx_buffers_zc(struct ixgbe_ring *rx_ring, u16 count)
 152{
 153        union ixgbe_adv_rx_desc *rx_desc;
 154        struct ixgbe_rx_buffer *bi;
 155        u16 i = rx_ring->next_to_use;
 156        dma_addr_t dma;
 157        bool ok = true;
 158
 159        /* nothing to do */
 160        if (!count)
 161                return true;
 162
 163        rx_desc = IXGBE_RX_DESC(rx_ring, i);
 164        bi = &rx_ring->rx_buffer_info[i];
 165        i -= rx_ring->count;
 166
 167        do {
 168                bi->xdp = xsk_buff_alloc(rx_ring->xsk_pool);
 169                if (!bi->xdp) {
 170                        ok = false;
 171                        break;
 172                }
 173
 174                dma = xsk_buff_xdp_get_dma(bi->xdp);
 175
 176                /* Refresh the desc even if buffer_addrs didn't change
 177                 * because each write-back erases this info.
 178                 */
 179                rx_desc->read.pkt_addr = cpu_to_le64(dma);
 180
 181                rx_desc++;
 182                bi++;
 183                i++;
 184                if (unlikely(!i)) {
 185                        rx_desc = IXGBE_RX_DESC(rx_ring, 0);
 186                        bi = rx_ring->rx_buffer_info;
 187                        i -= rx_ring->count;
 188                }
 189
 190                /* clear the length for the next_to_use descriptor */
 191                rx_desc->wb.upper.length = 0;
 192
 193                count--;
 194        } while (count);
 195
 196        i += rx_ring->count;
 197
 198        if (rx_ring->next_to_use != i) {
 199                rx_ring->next_to_use = i;
 200
 201                /* Force memory writes to complete before letting h/w
 202                 * know there are new descriptors to fetch.  (Only
 203                 * applicable for weak-ordered memory model archs,
 204                 * such as IA-64).
 205                 */
 206                wmb();
 207                writel(i, rx_ring->tail);
 208        }
 209
 210        return ok;
 211}
 212
 213static struct sk_buff *ixgbe_construct_skb_zc(struct ixgbe_ring *rx_ring,
 214                                              const struct xdp_buff *xdp)
 215{
 216        unsigned int totalsize = xdp->data_end - xdp->data_meta;
 217        unsigned int metasize = xdp->data - xdp->data_meta;
 218        struct sk_buff *skb;
 219
 220        net_prefetch(xdp->data_meta);
 221
 222        /* allocate a skb to store the frags */
 223        skb = __napi_alloc_skb(&rx_ring->q_vector->napi, totalsize,
 224                               GFP_ATOMIC | __GFP_NOWARN);
 225        if (unlikely(!skb))
 226                return NULL;
 227
 228        memcpy(__skb_put(skb, totalsize), xdp->data_meta,
 229               ALIGN(totalsize, sizeof(long)));
 230
 231        if (metasize) {
 232                skb_metadata_set(skb, metasize);
 233                __skb_pull(skb, metasize);
 234        }
 235
 236        return skb;
 237}
 238
 239static void ixgbe_inc_ntc(struct ixgbe_ring *rx_ring)
 240{
 241        u32 ntc = rx_ring->next_to_clean + 1;
 242
 243        ntc = (ntc < rx_ring->count) ? ntc : 0;
 244        rx_ring->next_to_clean = ntc;
 245        prefetch(IXGBE_RX_DESC(rx_ring, ntc));
 246}
 247
 248int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector,
 249                          struct ixgbe_ring *rx_ring,
 250                          const int budget)
 251{
 252        unsigned int total_rx_bytes = 0, total_rx_packets = 0;
 253        struct ixgbe_adapter *adapter = q_vector->adapter;
 254        u16 cleaned_count = ixgbe_desc_unused(rx_ring);
 255        unsigned int xdp_res, xdp_xmit = 0;
 256        bool failure = false;
 257        struct sk_buff *skb;
 258
 259        while (likely(total_rx_packets < budget)) {
 260                union ixgbe_adv_rx_desc *rx_desc;
 261                struct ixgbe_rx_buffer *bi;
 262                unsigned int size;
 263
 264                /* return some buffers to hardware, one at a time is too slow */
 265                if (cleaned_count >= IXGBE_RX_BUFFER_WRITE) {
 266                        failure = failure ||
 267                                  !ixgbe_alloc_rx_buffers_zc(rx_ring,
 268                                                             cleaned_count);
 269                        cleaned_count = 0;
 270                }
 271
 272                rx_desc = IXGBE_RX_DESC(rx_ring, rx_ring->next_to_clean);
 273                size = le16_to_cpu(rx_desc->wb.upper.length);
 274                if (!size)
 275                        break;
 276
 277                /* This memory barrier is needed to keep us from reading
 278                 * any other fields out of the rx_desc until we know the
 279                 * descriptor has been written back
 280                 */
 281                dma_rmb();
 282
 283                bi = &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
 284
 285                if (unlikely(!ixgbe_test_staterr(rx_desc,
 286                                                 IXGBE_RXD_STAT_EOP))) {
 287                        struct ixgbe_rx_buffer *next_bi;
 288
 289                        xsk_buff_free(bi->xdp);
 290                        bi->xdp = NULL;
 291                        ixgbe_inc_ntc(rx_ring);
 292                        next_bi =
 293                               &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
 294                        next_bi->discard = true;
 295                        continue;
 296                }
 297
 298                if (unlikely(bi->discard)) {
 299                        xsk_buff_free(bi->xdp);
 300                        bi->xdp = NULL;
 301                        bi->discard = false;
 302                        ixgbe_inc_ntc(rx_ring);
 303                        continue;
 304                }
 305
 306                bi->xdp->data_end = bi->xdp->data + size;
 307                xsk_buff_dma_sync_for_cpu(bi->xdp, rx_ring->xsk_pool);
 308                xdp_res = ixgbe_run_xdp_zc(adapter, rx_ring, bi->xdp);
 309
 310                if (likely(xdp_res & (IXGBE_XDP_TX | IXGBE_XDP_REDIR))) {
 311                        xdp_xmit |= xdp_res;
 312                } else if (xdp_res == IXGBE_XDP_EXIT) {
 313                        failure = true;
 314                        break;
 315                } else if (xdp_res == IXGBE_XDP_CONSUMED) {
 316                        xsk_buff_free(bi->xdp);
 317                } else if (xdp_res == IXGBE_XDP_PASS) {
 318                        goto construct_skb;
 319                }
 320
 321                bi->xdp = NULL;
 322                total_rx_packets++;
 323                total_rx_bytes += size;
 324
 325                cleaned_count++;
 326                ixgbe_inc_ntc(rx_ring);
 327                continue;
 328
 329construct_skb:
 330                /* XDP_PASS path */
 331                skb = ixgbe_construct_skb_zc(rx_ring, bi->xdp);
 332                if (!skb) {
 333                        rx_ring->rx_stats.alloc_rx_buff_failed++;
 334                        break;
 335                }
 336
 337                xsk_buff_free(bi->xdp);
 338                bi->xdp = NULL;
 339
 340                cleaned_count++;
 341                ixgbe_inc_ntc(rx_ring);
 342
 343                if (eth_skb_pad(skb))
 344                        continue;
 345
 346                total_rx_bytes += skb->len;
 347                total_rx_packets++;
 348
 349                ixgbe_process_skb_fields(rx_ring, rx_desc, skb);
 350                ixgbe_rx_skb(q_vector, skb);
 351        }
 352
 353        if (xdp_xmit & IXGBE_XDP_REDIR)
 354                xdp_do_flush_map();
 355
 356        if (xdp_xmit & IXGBE_XDP_TX) {
 357                struct ixgbe_ring *ring = ixgbe_determine_xdp_ring(adapter);
 358
 359                ixgbe_xdp_ring_update_tail_locked(ring);
 360        }
 361
 362        u64_stats_update_begin(&rx_ring->syncp);
 363        rx_ring->stats.packets += total_rx_packets;
 364        rx_ring->stats.bytes += total_rx_bytes;
 365        u64_stats_update_end(&rx_ring->syncp);
 366        q_vector->rx.total_packets += total_rx_packets;
 367        q_vector->rx.total_bytes += total_rx_bytes;
 368
 369        if (xsk_uses_need_wakeup(rx_ring->xsk_pool)) {
 370                if (failure || rx_ring->next_to_clean == rx_ring->next_to_use)
 371                        xsk_set_rx_need_wakeup(rx_ring->xsk_pool);
 372                else
 373                        xsk_clear_rx_need_wakeup(rx_ring->xsk_pool);
 374
 375                return (int)total_rx_packets;
 376        }
 377        return failure ? budget : (int)total_rx_packets;
 378}
 379
 380void ixgbe_xsk_clean_rx_ring(struct ixgbe_ring *rx_ring)
 381{
 382        struct ixgbe_rx_buffer *bi;
 383        u16 i;
 384
 385        for (i = 0; i < rx_ring->count; i++) {
 386                bi = &rx_ring->rx_buffer_info[i];
 387
 388                if (!bi->xdp)
 389                        continue;
 390
 391                xsk_buff_free(bi->xdp);
 392                bi->xdp = NULL;
 393        }
 394}
 395
 396static bool ixgbe_xmit_zc(struct ixgbe_ring *xdp_ring, unsigned int budget)
 397{
 398        struct xsk_buff_pool *pool = xdp_ring->xsk_pool;
 399        union ixgbe_adv_tx_desc *tx_desc = NULL;
 400        struct ixgbe_tx_buffer *tx_bi;
 401        bool work_done = true;
 402        struct xdp_desc desc;
 403        dma_addr_t dma;
 404        u32 cmd_type;
 405
 406        while (budget-- > 0) {
 407                if (unlikely(!ixgbe_desc_unused(xdp_ring))) {
 408                        work_done = false;
 409                        break;
 410                }
 411
 412                if (!netif_carrier_ok(xdp_ring->netdev))
 413                        break;
 414
 415                if (!xsk_tx_peek_desc(pool, &desc))
 416                        break;
 417
 418                dma = xsk_buff_raw_get_dma(pool, desc.addr);
 419                xsk_buff_raw_dma_sync_for_device(pool, dma, desc.len);
 420
 421                tx_bi = &xdp_ring->tx_buffer_info[xdp_ring->next_to_use];
 422                tx_bi->bytecount = desc.len;
 423                tx_bi->xdpf = NULL;
 424                tx_bi->gso_segs = 1;
 425
 426                tx_desc = IXGBE_TX_DESC(xdp_ring, xdp_ring->next_to_use);
 427                tx_desc->read.buffer_addr = cpu_to_le64(dma);
 428
 429                /* put descriptor type bits */
 430                cmd_type = IXGBE_ADVTXD_DTYP_DATA |
 431                           IXGBE_ADVTXD_DCMD_DEXT |
 432                           IXGBE_ADVTXD_DCMD_IFCS;
 433                cmd_type |= desc.len | IXGBE_TXD_CMD;
 434                tx_desc->read.cmd_type_len = cpu_to_le32(cmd_type);
 435                tx_desc->read.olinfo_status =
 436                        cpu_to_le32(desc.len << IXGBE_ADVTXD_PAYLEN_SHIFT);
 437
 438                xdp_ring->next_to_use++;
 439                if (xdp_ring->next_to_use == xdp_ring->count)
 440                        xdp_ring->next_to_use = 0;
 441        }
 442
 443        if (tx_desc) {
 444                ixgbe_xdp_ring_update_tail(xdp_ring);
 445                xsk_tx_release(pool);
 446        }
 447
 448        return !!budget && work_done;
 449}
 450
 451static void ixgbe_clean_xdp_tx_buffer(struct ixgbe_ring *tx_ring,
 452                                      struct ixgbe_tx_buffer *tx_bi)
 453{
 454        xdp_return_frame(tx_bi->xdpf);
 455        dma_unmap_single(tx_ring->dev,
 456                         dma_unmap_addr(tx_bi, dma),
 457                         dma_unmap_len(tx_bi, len), DMA_TO_DEVICE);
 458        dma_unmap_len_set(tx_bi, len, 0);
 459}
 460
 461bool ixgbe_clean_xdp_tx_irq(struct ixgbe_q_vector *q_vector,
 462                            struct ixgbe_ring *tx_ring, int napi_budget)
 463{
 464        u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
 465        unsigned int total_packets = 0, total_bytes = 0;
 466        struct xsk_buff_pool *pool = tx_ring->xsk_pool;
 467        union ixgbe_adv_tx_desc *tx_desc;
 468        struct ixgbe_tx_buffer *tx_bi;
 469        u32 xsk_frames = 0;
 470
 471        tx_bi = &tx_ring->tx_buffer_info[ntc];
 472        tx_desc = IXGBE_TX_DESC(tx_ring, ntc);
 473
 474        while (ntc != ntu) {
 475                if (!(tx_desc->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD)))
 476                        break;
 477
 478                total_bytes += tx_bi->bytecount;
 479                total_packets += tx_bi->gso_segs;
 480
 481                if (tx_bi->xdpf)
 482                        ixgbe_clean_xdp_tx_buffer(tx_ring, tx_bi);
 483                else
 484                        xsk_frames++;
 485
 486                tx_bi->xdpf = NULL;
 487
 488                tx_bi++;
 489                tx_desc++;
 490                ntc++;
 491                if (unlikely(ntc == tx_ring->count)) {
 492                        ntc = 0;
 493                        tx_bi = tx_ring->tx_buffer_info;
 494                        tx_desc = IXGBE_TX_DESC(tx_ring, 0);
 495                }
 496
 497                /* issue prefetch for next Tx descriptor */
 498                prefetch(tx_desc);
 499        }
 500
 501        tx_ring->next_to_clean = ntc;
 502
 503        u64_stats_update_begin(&tx_ring->syncp);
 504        tx_ring->stats.bytes += total_bytes;
 505        tx_ring->stats.packets += total_packets;
 506        u64_stats_update_end(&tx_ring->syncp);
 507        q_vector->tx.total_bytes += total_bytes;
 508        q_vector->tx.total_packets += total_packets;
 509
 510        if (xsk_frames)
 511                xsk_tx_completed(pool, xsk_frames);
 512
 513        if (xsk_uses_need_wakeup(pool))
 514                xsk_set_tx_need_wakeup(pool);
 515
 516        return ixgbe_xmit_zc(tx_ring, q_vector->tx.work_limit);
 517}
 518
 519int ixgbe_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
 520{
 521        struct ixgbe_adapter *adapter = netdev_priv(dev);
 522        struct ixgbe_ring *ring;
 523
 524        if (test_bit(__IXGBE_DOWN, &adapter->state))
 525                return -ENETDOWN;
 526
 527        if (!READ_ONCE(adapter->xdp_prog))
 528                return -EINVAL;
 529
 530        if (qid >= adapter->num_xdp_queues)
 531                return -EINVAL;
 532
 533        ring = adapter->xdp_ring[qid];
 534
 535        if (test_bit(__IXGBE_TX_DISABLED, &ring->state))
 536                return -ENETDOWN;
 537
 538        if (!ring->xsk_pool)
 539                return -EINVAL;
 540
 541        if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi)) {
 542                u64 eics = BIT_ULL(ring->q_vector->v_idx);
 543
 544                ixgbe_irq_rearm_queues(adapter, eics);
 545        }
 546
 547        return 0;
 548}
 549
 550void ixgbe_xsk_clean_tx_ring(struct ixgbe_ring *tx_ring)
 551{
 552        u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
 553        struct xsk_buff_pool *pool = tx_ring->xsk_pool;
 554        struct ixgbe_tx_buffer *tx_bi;
 555        u32 xsk_frames = 0;
 556
 557        while (ntc != ntu) {
 558                tx_bi = &tx_ring->tx_buffer_info[ntc];
 559
 560                if (tx_bi->xdpf)
 561                        ixgbe_clean_xdp_tx_buffer(tx_ring, tx_bi);
 562                else
 563                        xsk_frames++;
 564
 565                tx_bi->xdpf = NULL;
 566
 567                ntc++;
 568                if (ntc == tx_ring->count)
 569                        ntc = 0;
 570        }
 571
 572        if (xsk_frames)
 573                xsk_tx_completed(pool, xsk_frames);
 574}
 575