sys/dev/netmap/if_lem_netmap.h

   1 /*
   2  * Copyright (C) 2011-2014 Matteo Landi, Luigi Rizzo. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  23  * SUCH DAMAGE.
  24  */
  25
  26
  27 /*
  28  * $FreeBSD$
  29  *
  30  * netmap support for: lem
  31  *
  32  * For details on netmap support please see ixgbe_netmap.h
  33  */
  34
  35
  36 #include <net/netmap.h>
  37 #include <sys/selinfo.h>
  38 #include <vm/vm.h>
  39 #include <vm/pmap.h>    /* vtophys ? */
  40 #include <dev/netmap/netmap_kern.h>
  41
  42 extern int netmap_adaptive_io;
  43
  44 /*
  45  * Register/unregister. We are already under netmap lock.
  46  */
  47 static int
  48 lem_netmap_reg(struct netmap_adapter *na, int onoff)
  49 {
  50         struct ifnet *ifp = na->ifp;
  51         struct adapter *adapter = ifp->if_softc;
  52
  53         EM_CORE_LOCK(adapter);
  54
  55         lem_disable_intr(adapter);
  56
  57         /* Tell the stack that the interface is no longer active */
  58         ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
  59
  60 #ifndef EM_LEGACY_IRQ // XXX do we need this ?
  61         taskqueue_block(adapter->tq);
  62         taskqueue_drain(adapter->tq, &adapter->rxtx_task);
  63         taskqueue_drain(adapter->tq, &adapter->link_task);
  64 #endif /* !EM_LEGCY_IRQ */
  65
  66         /* enable or disable flags and callbacks in na and ifp */
  67         if (onoff) {
  68                 nm_set_native_flags(na);
  69         } else {
  70                 nm_clear_native_flags(na);
  71         }
  72         lem_init_locked(adapter);       /* also enable intr */
  73
  74 #ifndef EM_LEGACY_IRQ
  75         taskqueue_unblock(adapter->tq); // XXX do we need this ?
  76 #endif /* !EM_LEGCY_IRQ */
  77
  78         EM_CORE_UNLOCK(adapter);
  79
  80         return (ifp->if_drv_flags & IFF_DRV_RUNNING ? 0 : 1);
  81 }
  82
  83
  84 /*
  85  * Reconcile kernel and user view of the transmit ring.
  86  */
  87 static int
  88 lem_netmap_txsync(struct netmap_kring *kring, int flags)
  89 {
  90         struct netmap_adapter *na = kring->na;
  91         struct ifnet *ifp = na->ifp;
  92         struct netmap_ring *ring = kring->ring;
  93         u_int nm_i;     /* index into the netmap ring */
  94         u_int nic_i;    /* index into the NIC ring */
  95         u_int const lim = kring->nkr_num_slots - 1;
  96         u_int const head = kring->rhead;
  97         /* generate an interrupt approximately every half ring */
  98         u_int report_frequency = kring->nkr_num_slots >> 1;
  99
 100         /* device-specific */
 101         struct adapter *adapter = ifp->if_softc;
 102 #ifdef NIC_PARAVIRT
 103         struct paravirt_csb *csb = adapter->csb;
 104         uint64_t *csbd = (uint64_t *)(csb + 1);
 105 #endif /* NIC_PARAVIRT */
 106
 107         bus_dmamap_sync(adapter->txdma.dma_tag, adapter->txdma.dma_map,
 108                         BUS_DMASYNC_POSTREAD);
 109
 110         /*
 111          * First part: process new packets to send.
 112          */
 113
 114         nm_i = kring->nr_hwcur;
 115         if (nm_i != head) {     /* we have new packets to send */
 116 #ifdef NIC_PARAVIRT
 117                 int do_kick = 0;
 118                 uint64_t t = 0; // timestamp
 119                 int n = head - nm_i;
 120                 if (n < 0)
 121                         n += lim + 1;
 122                 if (csb) {
 123                         t = rdtsc(); /* last timestamp */
 124                         csbd[16] += t - csbd[0]; /* total Wg */
 125                         csbd[17] += n;          /* Wg count */
 126                         csbd[0] = t;
 127                 }
 128 #endif /* NIC_PARAVIRT */
 129                 nic_i = netmap_idx_k2n(kring, nm_i);
 130                 while (nm_i != head) {
 131                         struct netmap_slot *slot = &ring->slot[nm_i];
 132                         u_int len = slot->len;
 133                         uint64_t paddr;
 134                         void *addr = PNMB(na, slot, &paddr);
 135
 136                         /* device-specific */
 137                         struct e1000_tx_desc *curr = &adapter->tx_desc_base[nic_i];
 138                         struct em_buffer *txbuf = &adapter->tx_buffer_area[nic_i];
 139                         int flags = (slot->flags & NS_REPORT ||
 140                                 nic_i == 0 || nic_i == report_frequency) ?
 141                                 E1000_TXD_CMD_RS : 0;
 142
 143                         NM_CHECK_ADDR_LEN(na, addr, len);
 144
 145                         if (slot->flags & NS_BUF_CHANGED) {
 146                                 /* buffer has changed, reload map */
 147                                 curr->buffer_addr = htole64(paddr);
 148                                 netmap_reload_map(na, adapter->txtag, txbuf->map, addr);
 149                         }
 150                         slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
 151
 152                         /* Fill the slot in the NIC ring. */
 153                         curr->upper.data = 0;
 154                         curr->lower.data = htole32(adapter->txd_cmd | len |
 155                                 (E1000_TXD_CMD_EOP | flags) );
 156                         bus_dmamap_sync(adapter->txtag, txbuf->map,
 157                                 BUS_DMASYNC_PREWRITE);
 158
 159                         nm_i = nm_next(nm_i, lim);
 160                         nic_i = nm_next(nic_i, lim);
 161                         // XXX might try an early kick
 162                 }
 163                 kring->nr_hwcur = head;
 164
 165                  /* synchronize the NIC ring */
 166                 bus_dmamap_sync(adapter->txdma.dma_tag, adapter->txdma.dma_map,
 167                         BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
 168
 169 #ifdef NIC_PARAVIRT
 170                 /* set unconditionally, then also kick if needed */
 171                 if (csb) {
 172                         t = rdtsc();
 173                         if (csb->host_need_txkick == 2) {
 174                                 /* can compute an update of delta */
 175                                 int64_t delta = t - csbd[3];
 176                                 if (delta < 0)
 177                                         delta = -delta;
 178                                 if (csbd[8] == 0 || delta < csbd[8]) {
 179                                         csbd[8] = delta;
 180                                         csbd[9]++;
 181                                 }
 182                                 csbd[10]++;
 183                         }
 184                         csb->guest_tdt = nic_i;
 185                         csbd[18] += t - csbd[0]; // total wp
 186                         csbd[19] += n;
 187                 }
 188                 if (!csb || !csb->guest_csb_on || (csb->host_need_txkick & 1))
 189                         do_kick = 1;
 190                 if (do_kick)
 191 #endif /* NIC_PARAVIRT */
 192                 /* (re)start the tx unit up to slot nic_i (excluded) */
 193                 E1000_WRITE_REG(&adapter->hw, E1000_TDT(0), nic_i);
 194 #ifdef NIC_PARAVIRT
 195                 if (do_kick) {
 196                         uint64_t t1 = rdtsc();
 197                         csbd[20] += t1 - t; // total Np
 198                         csbd[21]++;
 199                 }
 200 #endif /* NIC_PARAVIRT */
 201         }
 202
 203         /*
 204          * Second part: reclaim buffers for completed transmissions.
 205          */
 206         if (ticks != kring->last_reclaim || flags & NAF_FORCE_RECLAIM || nm_kr_txempty(kring)) {
 207                 kring->last_reclaim = ticks;
 208                 /* record completed transmissions using TDH */
 209 #ifdef NIC_PARAVIRT
 210                 /* host updates tdh unconditionally, and we have
 211                  * no side effects on reads, so we can read from there
 212                  * instead of exiting.
 213                  */
 214                 if (csb) {
 215                     static int drain = 0, nodrain=0, good = 0, bad = 0, fail = 0;
 216                     u_int x = adapter->next_tx_to_clean;
 217                     csbd[19]++; // XXX count reclaims
 218                     nic_i = csb->host_tdh;
 219                     if (csb->guest_csb_on) {
 220                         if (nic_i == x) {
 221                             bad++;
 222                             csbd[24]++; // failed reclaims
 223                             /* no progress, request kick and retry */
 224                             csb->guest_need_txkick = 1;
 225                             mb(); // XXX barrier
 226                             nic_i = csb->host_tdh;
 227                         } else {
 228                             good++;
 229                         }
 230                         if (nic_i != x) {
 231                             csb->guest_need_txkick = 2;
 232                             if (nic_i == csb->guest_tdt)
 233                                 drain++;
 234                             else
 235                                 nodrain++;
 236 #if 1
 237                         if (netmap_adaptive_io) {
 238                             /* new mechanism: last half ring (or so)
 239                              * released one slot at a time.
 240                              * This effectively makes the system spin.
 241                              *
 242                              * Take next_to_clean + 1 as a reference.
 243                              * tdh must be ahead or equal
 244                              * On entry, the logical order is
 245                              *          x < tdh = nic_i
 246                              * We first push tdh up to avoid wraps.
 247                              * The limit is tdh-ll (half ring).
 248                              * if tdh-256 < x we report x;
 249                              * else we report tdh-256
 250                              */
 251                             u_int tdh = nic_i;
 252                             u_int ll = csbd[15];
 253                             u_int delta = lim/8;
 254                             if (netmap_adaptive_io == 2 || ll > delta)
 255                                 csbd[15] = ll = delta;
 256                             else if (netmap_adaptive_io == 1 && ll > 1) {
 257                                 csbd[15]--;
 258                             }
 259
 260                             if (nic_i >= kring->nkr_num_slots) {
 261                                 RD(5, "bad nic_i %d on input", nic_i);
 262                             }
 263                             x = nm_next(x, lim);
 264                             if (tdh < x)
 265                                 tdh += lim + 1;
 266                             if (tdh <= x + ll) {
 267                                 nic_i = x;
 268                                 csbd[25]++; //report n + 1;
 269                             } else {
 270                                 tdh = nic_i;
 271                                 if (tdh < ll)
 272                                     tdh += lim + 1;
 273                                 nic_i = tdh - ll;
 274                                 csbd[26]++; // report tdh - ll
 275                             }
 276                         }
 277 #endif
 278                         } else {
 279                             /* we stop, count whether we are idle or not */
 280                             int bh_active = csb->host_need_txkick & 2 ? 4 : 0;
 281                             csbd[27+ csb->host_need_txkick]++;
 282                             if (netmap_adaptive_io == 1) {
 283                                 if (bh_active && csbd[15] > 1)
 284                                     csbd[15]--;
 285                                 else if (!bh_active && csbd[15] < lim/2)
 286                                     csbd[15]++;
 287                             }
 288                             bad--;
 289                             fail++;
 290                         }
 291                     }
 292                     RD(1, "drain %d nodrain %d good %d retry %d fail %d",
 293                         drain, nodrain, good, bad, fail);
 294                 } else
 295 #endif /* !NIC_PARAVIRT */
 296                 nic_i = E1000_READ_REG(&adapter->hw, E1000_TDH(0));
 297                 if (nic_i >= kring->nkr_num_slots) { /* XXX can it happen ? */
 298                         D("TDH wrap %d", nic_i);
 299                         nic_i -= kring->nkr_num_slots;
 300                 }
 301                 adapter->next_tx_to_clean = nic_i;
 302                 kring->nr_hwtail = nm_prev(netmap_idx_n2k(kring, nic_i), lim);
 303         }
 304
 305         nm_txsync_finalize(kring);
 306
 307         return 0;
 308 }
 309
 310
 311 /*
 312  * Reconcile kernel and user view of the receive ring.
 313  */
 314 static int
 315 lem_netmap_rxsync(struct netmap_kring *kring, int flags)
 316 {
 317         struct netmap_adapter *na = kring->na;
 318         struct ifnet *ifp = na->ifp;
 319         struct netmap_ring *ring = kring->ring;
 320         u_int nm_i;     /* index into the netmap ring */
 321         u_int nic_i;    /* index into the NIC ring */
 322         u_int n;
 323         u_int const lim = kring->nkr_num_slots - 1;
 324         u_int const head = nm_rxsync_prologue(kring);
 325         int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR;
 326
 327         /* device-specific */
 328         struct adapter *adapter = ifp->if_softc;
 329 #ifdef NIC_PARAVIRT
 330         struct paravirt_csb *csb = adapter->csb;
 331         uint32_t csb_mode = csb && csb->guest_csb_on;
 332         uint32_t do_host_rxkick = 0;
 333 #endif /* NIC_PARAVIRT */
 334
 335         if (head > lim)
 336                 return netmap_ring_reinit(kring);
 337
 338 #ifdef NIC_PARAVIRT
 339         if (csb_mode) {
 340                 force_update = 1;
 341                 csb->guest_need_rxkick = 0;
 342         }
 343 #endif /* NIC_PARAVIRT */
 344         /* XXX check sync modes */
 345         bus_dmamap_sync(adapter->rxdma.dma_tag, adapter->rxdma.dma_map,
 346                         BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
 347
 348         /*
 349          * First part: import newly received packets.
 350          */
 351         if (netmap_no_pendintr || force_update) {
 352                 uint16_t slot_flags = kring->nkr_slot_flags;
 353
 354                 nic_i = adapter->next_rx_desc_to_check;
 355                 nm_i = netmap_idx_n2k(kring, nic_i);
 356
 357                 for (n = 0; ; n++) {
 358                         struct e1000_rx_desc *curr = &adapter->rx_desc_base[nic_i];
 359                         uint32_t staterr = le32toh(curr->status);
 360                         int len;
 361
 362 #ifdef NIC_PARAVIRT
 363                         if (csb_mode) {
 364                             if ((staterr & E1000_RXD_STAT_DD) == 0) {
 365                                 /* don't bother to retry if more than 1 pkt */
 366                                 if (n > 1)
 367                                     break;
 368                                 csb->guest_need_rxkick = 1;
 369                                 wmb();
 370                                 staterr = le32toh(curr->status);
 371                                 if ((staterr & E1000_RXD_STAT_DD) == 0) {
 372                                     break;
 373                                 } else { /* we are good */
 374                                    csb->guest_need_rxkick = 0;
 375                                 }
 376                             }
 377                         } else
 378 #endif /* NIC_PARAVIRT */
 379                         if ((staterr & E1000_RXD_STAT_DD) == 0)
 380                                 break;
 381                         len = le16toh(curr->length) - 4; // CRC
 382                         if (len < 0) {
 383                                 RD(5, "bogus pkt (%d) size %d nic idx %d", n, len, nic_i);
 384                                 len = 0;
 385                         }
 386                         ring->slot[nm_i].len = len;
 387                         ring->slot[nm_i].flags = slot_flags;
 388                         bus_dmamap_sync(adapter->rxtag,
 389                                 adapter->rx_buffer_area[nic_i].map,
 390                                 BUS_DMASYNC_POSTREAD);
 391                         nm_i = nm_next(nm_i, lim);
 392                         nic_i = nm_next(nic_i, lim);
 393                 }
 394                 if (n) { /* update the state variables */
 395 #ifdef NIC_PARAVIRT
 396                         if (csb_mode) {
 397                             if (n > 1) {
 398                                 /* leave one spare buffer so we avoid rxkicks */
 399                                 nm_i = nm_prev(nm_i, lim);
 400                                 nic_i = nm_prev(nic_i, lim);
 401                                 n--;
 402                             } else {
 403                                 csb->guest_need_rxkick = 1;
 404                             }
 405                         }
 406 #endif /* NIC_PARAVIRT */
 407                         ND("%d new packets at nic %d nm %d tail %d",
 408                                 n,
 409                                 adapter->next_rx_desc_to_check,
 410                                 netmap_idx_n2k(kring, adapter->next_rx_desc_to_check),
 411                                 kring->nr_hwtail);
 412                         adapter->next_rx_desc_to_check = nic_i;
 413                         // if_inc_counter(ifp, IFCOUNTER_IPACKETS, n);
 414                         kring->nr_hwtail = nm_i;
 415                 }
 416                 kring->nr_kflags &= ~NKR_PENDINTR;
 417         }
 418
 419         /*
 420          * Second part: skip past packets that userspace has released.
 421          */
 422         nm_i = kring->nr_hwcur;
 423         if (nm_i != head) {
 424                 nic_i = netmap_idx_k2n(kring, nm_i);
 425                 for (n = 0; nm_i != head; n++) {
 426                         struct netmap_slot *slot = &ring->slot[nm_i];
 427                         uint64_t paddr;
 428                         void *addr = PNMB(na, slot, &paddr);
 429
 430                         struct e1000_rx_desc *curr = &adapter->rx_desc_base[nic_i];
 431                         struct em_buffer *rxbuf = &adapter->rx_buffer_area[nic_i];
 432
 433                         if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
 434                                 goto ring_reset;
 435
 436                         if (slot->flags & NS_BUF_CHANGED) {
 437                                 /* buffer has changed, reload map */
 438                                 curr->buffer_addr = htole64(paddr);
 439                                 netmap_reload_map(na, adapter->rxtag, rxbuf->map, addr);
 440                                 slot->flags &= ~NS_BUF_CHANGED;
 441                         }
 442                         curr->status = 0;
 443                         bus_dmamap_sync(adapter->rxtag, rxbuf->map,
 444                             BUS_DMASYNC_PREREAD);
 445 #ifdef NIC_PARAVIRT
 446                         if (csb_mode && csb->host_rxkick_at == nic_i)
 447                                 do_host_rxkick = 1;
 448 #endif /* NIC_PARAVIRT */
 449                         nm_i = nm_next(nm_i, lim);
 450                         nic_i = nm_next(nic_i, lim);
 451                 }
 452                 kring->nr_hwcur = head;
 453                 bus_dmamap_sync(adapter->rxdma.dma_tag, adapter->rxdma.dma_map,
 454                     BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
 455                 /*
 456                  * IMPORTANT: we must leave one free slot in the ring,
 457                  * so move nic_i back by one unit
 458                  */
 459                 nic_i = nm_prev(nic_i, lim);
 460 #ifdef NIC_PARAVIRT
 461                 /* set unconditionally, then also kick if needed */
 462                 if (csb)
 463                         csb->guest_rdt = nic_i;
 464                 if (!csb_mode || do_host_rxkick)
 465 #endif /* NIC_PARAVIRT */
 466                 E1000_WRITE_REG(&adapter->hw, E1000_RDT(0), nic_i);
 467         }
 468
 469         /* tell userspace that there might be new packets */
 470         nm_rxsync_finalize(kring);
 471
 472         return 0;
 473
 474 ring_reset:
 475         return netmap_ring_reinit(kring);
 476 }
 477
 478
 479 static void
 480 lem_netmap_attach(struct adapter *adapter)
 481 {
 482         struct netmap_adapter na;
 483
 484         bzero(&na, sizeof(na));
 485
 486         na.ifp = adapter->ifp;
 487         na.na_flags = NAF_BDG_MAYSLEEP;
 488         na.num_tx_desc = adapter->num_tx_desc;
 489         na.num_rx_desc = adapter->num_rx_desc;
 490         na.nm_txsync = lem_netmap_txsync;
 491         na.nm_rxsync = lem_netmap_rxsync;
 492         na.nm_register = lem_netmap_reg;
 493         na.num_tx_rings = na.num_rx_rings = 1;
 494         netmap_attach(&na);
 495 }
 496
 497 /* end of file */