sys/dev/netmap/if_ptnet.c

   1 /*-
   2  * Copyright (c) 2016, Vincenzo Maffione
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice unmodified, this list of conditions, and the following
  10  *    disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * $FreeBSD$
  27  */
  28
  29 /* Driver for ptnet paravirtualized network device. */
  30
  31 #include <sys/cdefs.h>
  32
  33 #include <sys/types.h>
  34 #include <sys/param.h>
  35 #include <sys/systm.h>
  36 #include <sys/kernel.h>
  37 #include <sys/sockio.h>
  38 #include <sys/mbuf.h>
  39 #include <sys/malloc.h>
  40 #include <sys/module.h>
  41 #include <sys/socket.h>
  42 #include <sys/sysctl.h>
  43 #include <sys/lock.h>
  44 #include <sys/mutex.h>
  45 #include <sys/taskqueue.h>
  46 #include <sys/smp.h>
  47 #include <sys/time.h>
  48 #include <machine/smp.h>
  49
  50 #include <vm/uma.h>
  51 #include <vm/vm.h>
  52 #include <vm/pmap.h>
  53
  54 #include <net/ethernet.h>
  55 #include <net/if.h>
  56 #include <net/if_var.h>
  57 #include <net/if_arp.h>
  58 #include <net/if_dl.h>
  59 #include <net/if_types.h>
  60 #include <net/if_media.h>
  61 #include <net/if_vlan_var.h>
  62 #include <net/bpf.h>
  63
  64 #include <netinet/in_systm.h>
  65 #include <netinet/in.h>
  66 #include <netinet/ip.h>
  67 #include <netinet/ip6.h>
  68 #include <netinet6/ip6_var.h>
  69 #include <netinet/udp.h>
  70 #include <netinet/tcp.h>
  71
  72 #include <machine/bus.h>
  73 #include <machine/resource.h>
  74 #include <sys/bus.h>
  75 #include <sys/rman.h>
  76
  77 #include <dev/pci/pcivar.h>
  78 #include <dev/pci/pcireg.h>
  79
  80 #include "opt_inet.h"
  81 #include "opt_inet6.h"
  82
  83 #include <sys/selinfo.h>
  84 #include <net/netmap.h>
  85 #include <dev/netmap/netmap_kern.h>
  86 #include <net/netmap_virt.h>
  87 #include <dev/netmap/netmap_mem2.h>
  88 #include <dev/virtio/network/virtio_net.h>
  89
  90 #ifdef WITH_PTNETMAP
  91
  92 #ifndef INET
  93 #error "INET not defined, cannot support offloadings"
  94 #endif
  95
  96 #if __FreeBSD_version >= 1100000
  97 static uint64_t ptnet_get_counter(if_t, ift_counter);
  98 #else
  99 typedef struct ifnet *if_t;
 100 #define if_getsoftc(_ifp)   (_ifp)->if_softc
 101 #endif
 102
 103 //#define PTNETMAP_STATS
 104 //#define DEBUG
 105 #ifdef DEBUG
 106 #define DBG(x) x
 107 #else   /* !DEBUG */
 108 #define DBG(x)
 109 #endif  /* !DEBUG */
 110
 111 extern int ptnet_vnet_hdr; /* Tunable parameter */
 112
 113 struct ptnet_softc;
 114
 115 struct ptnet_queue_stats {
 116         uint64_t        packets; /* if_[io]packets */
 117         uint64_t        bytes;   /* if_[io]bytes */
 118         uint64_t        errors;  /* if_[io]errors */
 119         uint64_t        iqdrops; /* if_iqdrops */
 120         uint64_t        mcasts;  /* if_[io]mcasts */
 121 #ifdef PTNETMAP_STATS
 122         uint64_t        intrs;
 123         uint64_t        kicks;
 124 #endif /* PTNETMAP_STATS */
 125 };
 126
 127 struct ptnet_queue {
 128         struct ptnet_softc              *sc;
 129         struct                          resource *irq;
 130         void                            *cookie;
 131         int                             kring_id;
 132         struct nm_csb_atok              *atok;
 133         struct nm_csb_ktoa              *ktoa;
 134         unsigned int                    kick;
 135         struct mtx                      lock;
 136         struct buf_ring                 *bufring; /* for TX queues */
 137         struct ptnet_queue_stats        stats;
 138 #ifdef PTNETMAP_STATS
 139         struct ptnet_queue_stats        last_stats;
 140 #endif /* PTNETMAP_STATS */
 141         struct taskqueue                *taskq;
 142         struct task                     task;
 143         char                            lock_name[16];
 144 };
 145
 146 #define PTNET_Q_LOCK(_pq)       mtx_lock(&(_pq)->lock)
 147 #define PTNET_Q_TRYLOCK(_pq)    mtx_trylock(&(_pq)->lock)
 148 #define PTNET_Q_UNLOCK(_pq)     mtx_unlock(&(_pq)->lock)
 149
 150 struct ptnet_softc {
 151         device_t                dev;
 152         if_t                    ifp;
 153         struct ifmedia          media;
 154         struct mtx              lock;
 155         char                    lock_name[16];
 156         char                    hwaddr[ETHER_ADDR_LEN];
 157
 158         /* Mirror of PTFEAT register. */
 159         uint32_t                ptfeatures;
 160         unsigned int            vnet_hdr_len;
 161
 162         /* PCI BARs support. */
 163         struct resource         *iomem;
 164         struct resource         *msix_mem;
 165
 166         unsigned int            num_rings;
 167         unsigned int            num_tx_rings;
 168         struct ptnet_queue      *queues;
 169         struct ptnet_queue      *rxqueues;
 170         struct nm_csb_atok      *csb_gh;
 171         struct nm_csb_ktoa      *csb_hg;
 172
 173         unsigned int            min_tx_space;
 174
 175         struct netmap_pt_guest_adapter *ptna;
 176
 177         struct callout          tick;
 178 #ifdef PTNETMAP_STATS
 179         struct timeval          last_ts;
 180 #endif /* PTNETMAP_STATS */
 181 };
 182
 183 #define PTNET_CORE_LOCK(_sc)    mtx_lock(&(_sc)->lock)
 184 #define PTNET_CORE_UNLOCK(_sc)  mtx_unlock(&(_sc)->lock)
 185
 186 static int      ptnet_probe(device_t);
 187 static int      ptnet_attach(device_t);
 188 static int      ptnet_detach(device_t);
 189 static int      ptnet_suspend(device_t);
 190 static int      ptnet_resume(device_t);
 191 static int      ptnet_shutdown(device_t);
 192
 193 static void     ptnet_init(void *opaque);
 194 static int      ptnet_ioctl(if_t ifp, u_long cmd, caddr_t data);
 195 static int      ptnet_init_locked(struct ptnet_softc *sc);
 196 static int      ptnet_stop(struct ptnet_softc *sc);
 197 static int      ptnet_transmit(if_t ifp, struct mbuf *m);
 198 static int      ptnet_drain_transmit_queue(struct ptnet_queue *pq,
 199                                            unsigned int budget,
 200                                            bool may_resched);
 201 static void     ptnet_qflush(if_t ifp);
 202 static void     ptnet_tx_task(void *context, int pending);
 203
 204 static int      ptnet_media_change(if_t ifp);
 205 static void     ptnet_media_status(if_t ifp, struct ifmediareq *ifmr);
 206 #ifdef PTNETMAP_STATS
 207 static void     ptnet_tick(void *opaque);
 208 #endif
 209
 210 static int      ptnet_irqs_init(struct ptnet_softc *sc);
 211 static void     ptnet_irqs_fini(struct ptnet_softc *sc);
 212
 213 static uint32_t ptnet_nm_ptctl(struct ptnet_softc *sc, uint32_t cmd);
 214 static int      ptnet_nm_config(struct netmap_adapter *na,
 215                                 struct nm_config_info *info);
 216 static void     ptnet_update_vnet_hdr(struct ptnet_softc *sc);
 217 static int      ptnet_nm_register(struct netmap_adapter *na, int onoff);
 218 static int      ptnet_nm_txsync(struct netmap_kring *kring, int flags);
 219 static int      ptnet_nm_rxsync(struct netmap_kring *kring, int flags);
 220 static void     ptnet_nm_intr(struct netmap_adapter *na, int onoff);
 221
 222 static void     ptnet_tx_intr(void *opaque);
 223 static void     ptnet_rx_intr(void *opaque);
 224
 225 static unsigned ptnet_rx_discard(struct netmap_kring *kring,
 226                                  unsigned int head);
 227 static int      ptnet_rx_eof(struct ptnet_queue *pq, unsigned int budget,
 228                              bool may_resched);
 229 static void     ptnet_rx_task(void *context, int pending);
 230
 231 #ifdef DEVICE_POLLING
 232 static poll_handler_t ptnet_poll;
 233 #endif
 234
 235 static device_method_t ptnet_methods[] = {
 236         DEVMETHOD(device_probe,                 ptnet_probe),
 237         DEVMETHOD(device_attach,                ptnet_attach),
 238         DEVMETHOD(device_detach,                ptnet_detach),
 239         DEVMETHOD(device_suspend,               ptnet_suspend),
 240         DEVMETHOD(device_resume,                ptnet_resume),
 241         DEVMETHOD(device_shutdown,              ptnet_shutdown),
 242         DEVMETHOD_END
 243 };
 244
 245 static driver_t ptnet_driver = {
 246         "ptnet",
 247         ptnet_methods,
 248         sizeof(struct ptnet_softc)
 249 };
 250
 251 /* We use (SI_ORDER_MIDDLE+2) here, see DEV_MODULE_ORDERED() invocation. */
 252 static devclass_t ptnet_devclass;
 253 DRIVER_MODULE_ORDERED(ptnet, pci, ptnet_driver, ptnet_devclass,
 254                       NULL, NULL, SI_ORDER_MIDDLE + 2);
 255
 256 static int
 257 ptnet_probe(device_t dev)
 258 {
 259         if (pci_get_vendor(dev) != PTNETMAP_PCI_VENDOR_ID ||
 260                 pci_get_device(dev) != PTNETMAP_PCI_NETIF_ID) {
 261                 return (ENXIO);
 262         }
 263
 264         device_set_desc(dev, "ptnet network adapter");
 265
 266         return (BUS_PROBE_DEFAULT);
 267 }
 268
 269 static inline void ptnet_kick(struct ptnet_queue *pq)
 270 {
 271 #ifdef PTNETMAP_STATS
 272         pq->stats.kicks ++;
 273 #endif /* PTNETMAP_STATS */
 274         bus_write_4(pq->sc->iomem, pq->kick, 0);
 275 }
 276
 277 #define PTNET_BUF_RING_SIZE     4096
 278 #define PTNET_RX_BUDGET         512
 279 #define PTNET_RX_BATCH          1
 280 #define PTNET_TX_BUDGET         512
 281 #define PTNET_TX_BATCH          64
 282 #define PTNET_HDR_SIZE          sizeof(struct virtio_net_hdr_mrg_rxbuf)
 283 #define PTNET_MAX_PKT_SIZE      65536
 284
 285 #define PTNET_CSUM_OFFLOAD      (CSUM_TCP | CSUM_UDP)
 286 #define PTNET_CSUM_OFFLOAD_IPV6 (CSUM_TCP_IPV6 | CSUM_UDP_IPV6)
 287 #define PTNET_ALL_OFFLOAD       (CSUM_TSO | PTNET_CSUM_OFFLOAD |\
 288                                  PTNET_CSUM_OFFLOAD_IPV6)
 289
 290 static int
 291 ptnet_attach(device_t dev)
 292 {
 293         uint32_t ptfeatures = 0;
 294         unsigned int num_rx_rings, num_tx_rings;
 295         struct netmap_adapter na_arg;
 296         unsigned int nifp_offset;
 297         struct ptnet_softc *sc;
 298         if_t ifp;
 299         uint32_t macreg;
 300         int err, rid;
 301         int i;
 302
 303         sc = device_get_softc(dev);
 304         sc->dev = dev;
 305
 306         /* Setup PCI resources. */
 307         pci_enable_busmaster(dev);
 308
 309         rid = PCIR_BAR(PTNETMAP_IO_PCI_BAR);
 310         sc->iomem = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &rid,
 311                                            RF_ACTIVE);
 312         if (sc->iomem == NULL) {
 313                 device_printf(dev, "Failed to map I/O BAR\n");
 314                 return (ENXIO);
 315         }
 316
 317         /* Negotiate features with the hypervisor. */
 318         if (ptnet_vnet_hdr) {
 319                 ptfeatures |= PTNETMAP_F_VNET_HDR;
 320         }
 321         bus_write_4(sc->iomem, PTNET_IO_PTFEAT, ptfeatures); /* wanted */
 322         ptfeatures = bus_read_4(sc->iomem, PTNET_IO_PTFEAT); /* acked */
 323         sc->ptfeatures = ptfeatures;
 324
 325         num_tx_rings = bus_read_4(sc->iomem, PTNET_IO_NUM_TX_RINGS);
 326         num_rx_rings = bus_read_4(sc->iomem, PTNET_IO_NUM_RX_RINGS);
 327         sc->num_rings = num_tx_rings + num_rx_rings;
 328         sc->num_tx_rings = num_tx_rings;
 329
 330         if (sc->num_rings * sizeof(struct nm_csb_atok) > PAGE_SIZE) {
 331                 device_printf(dev, "CSB cannot handle that many rings (%u)\n",
 332                                 sc->num_rings);
 333                 err = ENOMEM;
 334                 goto err_path;
 335         }
 336
 337         /* Allocate CSB and carry out CSB allocation protocol. */
 338         sc->csb_gh = contigmalloc(2*PAGE_SIZE, M_DEVBUF, M_NOWAIT | M_ZERO,
 339                                   (size_t)0, -1UL, PAGE_SIZE, 0);
 340         if (sc->csb_gh == NULL) {
 341                 device_printf(dev, "Failed to allocate CSB\n");
 342                 err = ENOMEM;
 343                 goto err_path;
 344         }
 345         sc->csb_hg = (struct nm_csb_ktoa *)(((char *)sc->csb_gh) + PAGE_SIZE);
 346
 347         {
 348                 /*
 349                  * We use uint64_t rather than vm_paddr_t since we
 350                  * need 64 bit addresses even on 32 bit platforms.
 351                  */
 352                 uint64_t paddr = vtophys(sc->csb_gh);
 353
 354                 /* CSB allocation protocol: write to BAH first, then
 355                  * to BAL (for both GH and HG sections). */
 356                 bus_write_4(sc->iomem, PTNET_IO_CSB_GH_BAH,
 357                                 (paddr >> 32) & 0xffffffff);
 358                 bus_write_4(sc->iomem, PTNET_IO_CSB_GH_BAL,
 359                                 paddr & 0xffffffff);
 360                 paddr = vtophys(sc->csb_hg);
 361                 bus_write_4(sc->iomem, PTNET_IO_CSB_HG_BAH,
 362                                 (paddr >> 32) & 0xffffffff);
 363                 bus_write_4(sc->iomem, PTNET_IO_CSB_HG_BAL,
 364                                 paddr & 0xffffffff);
 365         }
 366
 367         /* Allocate and initialize per-queue data structures. */
 368         sc->queues = malloc(sizeof(struct ptnet_queue) * sc->num_rings,
 369                             M_DEVBUF, M_NOWAIT | M_ZERO);
 370         if (sc->queues == NULL) {
 371                 err = ENOMEM;
 372                 goto err_path;
 373         }
 374         sc->rxqueues = sc->queues + num_tx_rings;
 375
 376         for (i = 0; i < sc->num_rings; i++) {
 377                 struct ptnet_queue *pq = sc->queues + i;
 378
 379                 pq->sc = sc;
 380                 pq->kring_id = i;
 381                 pq->kick = PTNET_IO_KICK_BASE + 4 * i;
 382                 pq->atok = sc->csb_gh + i;
 383                 pq->ktoa = sc->csb_hg + i;
 384                 snprintf(pq->lock_name, sizeof(pq->lock_name), "%s-%d",
 385                          device_get_nameunit(dev), i);
 386                 mtx_init(&pq->lock, pq->lock_name, NULL, MTX_DEF);
 387                 if (i >= num_tx_rings) {
 388                         /* RX queue: fix kring_id. */
 389                         pq->kring_id -= num_tx_rings;
 390                 } else {
 391                         /* TX queue: allocate buf_ring. */
 392                         pq->bufring = buf_ring_alloc(PTNET_BUF_RING_SIZE,
 393                                                 M_DEVBUF, M_NOWAIT, &pq->lock);
 394                         if (pq->bufring == NULL) {
 395                                 err = ENOMEM;
 396                                 goto err_path;
 397                         }
 398                 }
 399         }
 400
 401         sc->min_tx_space = 64; /* Safe initial value. */
 402
 403         err = ptnet_irqs_init(sc);
 404         if (err) {
 405                 goto err_path;
 406         }
 407
 408         /* Setup Ethernet interface. */
 409         sc->ifp = ifp = if_alloc(IFT_ETHER);
 410         if (ifp == NULL) {
 411                 device_printf(dev, "Failed to allocate ifnet\n");
 412                 err = ENOMEM;
 413                 goto err_path;
 414         }
 415
 416         if_initname(ifp, device_get_name(dev), device_get_unit(dev));
 417         ifp->if_baudrate = IF_Gbps(10);
 418         ifp->if_softc = sc;
 419         ifp->if_flags = IFF_BROADCAST | IFF_MULTICAST | IFF_SIMPLEX;
 420         ifp->if_init = ptnet_init;
 421         ifp->if_ioctl = ptnet_ioctl;
 422 #if __FreeBSD_version >= 1100000
 423         ifp->if_get_counter = ptnet_get_counter;
 424 #endif
 425         ifp->if_transmit = ptnet_transmit;
 426         ifp->if_qflush = ptnet_qflush;
 427
 428         ifmedia_init(&sc->media, IFM_IMASK, ptnet_media_change,
 429                      ptnet_media_status);
 430         ifmedia_add(&sc->media, IFM_ETHER | IFM_10G_T | IFM_FDX, 0, NULL);
 431         ifmedia_set(&sc->media, IFM_ETHER | IFM_10G_T | IFM_FDX);
 432
 433         macreg = bus_read_4(sc->iomem, PTNET_IO_MAC_HI);
 434         sc->hwaddr[0] = (macreg >> 8) & 0xff;
 435         sc->hwaddr[1] = macreg & 0xff;
 436         macreg = bus_read_4(sc->iomem, PTNET_IO_MAC_LO);
 437         sc->hwaddr[2] = (macreg >> 24) & 0xff;
 438         sc->hwaddr[3] = (macreg >> 16) & 0xff;
 439         sc->hwaddr[4] = (macreg >> 8) & 0xff;
 440         sc->hwaddr[5] = macreg & 0xff;
 441
 442         ether_ifattach(ifp, sc->hwaddr);
 443
 444         ifp->if_hdrlen = sizeof(struct ether_vlan_header);
 445         ifp->if_capabilities |= IFCAP_JUMBO_MTU | IFCAP_VLAN_MTU;
 446
 447         if (sc->ptfeatures & PTNETMAP_F_VNET_HDR) {
 448                 /* Similarly to what the vtnet driver does, we can emulate
 449                  * VLAN offloadings by inserting and removing the 802.1Q
 450                  * header during transmit and receive. We are then able
 451                  * to do checksum offloading of VLAN frames. */
 452                 ifp->if_capabilities |= IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6
 453                                         | IFCAP_VLAN_HWCSUM
 454                                         | IFCAP_TSO | IFCAP_LRO
 455                                         | IFCAP_VLAN_HWTSO
 456                                         | IFCAP_VLAN_HWTAGGING;
 457         }
 458
 459         ifp->if_capenable = ifp->if_capabilities;
 460 #ifdef DEVICE_POLLING
 461         /* Don't enable polling by default. */
 462         ifp->if_capabilities |= IFCAP_POLLING;
 463 #endif
 464         snprintf(sc->lock_name, sizeof(sc->lock_name),
 465                  "%s", device_get_nameunit(dev));
 466         mtx_init(&sc->lock, sc->lock_name, "ptnet core lock", MTX_DEF);
 467         callout_init_mtx(&sc->tick, &sc->lock, 0);
 468
 469         /* Prepare a netmap_adapter struct instance to do netmap_attach(). */
 470         nifp_offset = bus_read_4(sc->iomem, PTNET_IO_NIFP_OFS);
 471         memset(&na_arg, 0, sizeof(na_arg));
 472         na_arg.ifp = ifp;
 473         na_arg.num_tx_desc = bus_read_4(sc->iomem, PTNET_IO_NUM_TX_SLOTS);
 474         na_arg.num_rx_desc = bus_read_4(sc->iomem, PTNET_IO_NUM_RX_SLOTS);
 475         na_arg.num_tx_rings = num_tx_rings;
 476         na_arg.num_rx_rings = num_rx_rings;
 477         na_arg.nm_config = ptnet_nm_config;
 478         na_arg.nm_krings_create = ptnet_nm_krings_create;
 479         na_arg.nm_krings_delete = ptnet_nm_krings_delete;
 480         na_arg.nm_dtor = ptnet_nm_dtor;
 481         na_arg.nm_intr = ptnet_nm_intr;
 482         na_arg.nm_register = ptnet_nm_register;
 483         na_arg.nm_txsync = ptnet_nm_txsync;
 484         na_arg.nm_rxsync = ptnet_nm_rxsync;
 485
 486         netmap_pt_guest_attach(&na_arg, nifp_offset,
 487                                 bus_read_4(sc->iomem, PTNET_IO_HOSTMEMID));
 488
 489         /* Now a netmap adapter for this ifp has been allocated, and it
 490          * can be accessed through NA(ifp). We also have to initialize the CSB
 491          * pointer. */
 492         sc->ptna = (struct netmap_pt_guest_adapter *)NA(ifp);
 493
 494         /* If virtio-net header was negotiated, set the virt_hdr_len field in
 495          * the netmap adapter, to inform users that this netmap adapter requires
 496          * the application to deal with the headers. */
 497         ptnet_update_vnet_hdr(sc);
 498
 499         device_printf(dev, "%s() completed\n", __func__);
 500
 501         return (0);
 502
 503 err_path:
 504         ptnet_detach(dev);
 505         return err;
 506 }
 507
 508 /* Stop host sync-kloop if it was running. */
 509 static void
 510 ptnet_device_shutdown(struct ptnet_softc *sc)
 511 {
 512         ptnet_nm_ptctl(sc, PTNETMAP_PTCTL_DELETE);
 513         bus_write_4(sc->iomem, PTNET_IO_CSB_GH_BAH, 0);
 514         bus_write_4(sc->iomem, PTNET_IO_CSB_GH_BAL, 0);
 515         bus_write_4(sc->iomem, PTNET_IO_CSB_HG_BAH, 0);
 516         bus_write_4(sc->iomem, PTNET_IO_CSB_HG_BAL, 0);
 517 }
 518
 519 static int
 520 ptnet_detach(device_t dev)
 521 {
 522         struct ptnet_softc *sc = device_get_softc(dev);
 523         int i;
 524
 525         ptnet_device_shutdown(sc);
 526
 527 #ifdef DEVICE_POLLING
 528         if (sc->ifp->if_capenable & IFCAP_POLLING) {
 529                 ether_poll_deregister(sc->ifp);
 530         }
 531 #endif
 532         callout_drain(&sc->tick);
 533
 534         if (sc->queues) {
 535                 /* Drain taskqueues before calling if_detach. */
 536                 for (i = 0; i < sc->num_rings; i++) {
 537                         struct ptnet_queue *pq = sc->queues + i;
 538
 539                         if (pq->taskq) {
 540                                 taskqueue_drain(pq->taskq, &pq->task);
 541                         }
 542                 }
 543         }
 544
 545         if (sc->ifp) {
 546                 ether_ifdetach(sc->ifp);
 547
 548                 /* Uninitialize netmap adapters for this device. */
 549                 netmap_detach(sc->ifp);
 550
 551                 ifmedia_removeall(&sc->media);
 552                 if_free(sc->ifp);
 553                 sc->ifp = NULL;
 554         }
 555
 556         ptnet_irqs_fini(sc);
 557
 558         if (sc->csb_gh) {
 559                 contigfree(sc->csb_gh, 2*PAGE_SIZE, M_DEVBUF);
 560                 sc->csb_gh = NULL;
 561                 sc->csb_hg = NULL;
 562         }
 563
 564         if (sc->queues) {
 565                 for (i = 0; i < sc->num_rings; i++) {
 566                         struct ptnet_queue *pq = sc->queues + i;
 567
 568                         if (mtx_initialized(&pq->lock)) {
 569                                 mtx_destroy(&pq->lock);
 570                         }
 571                         if (pq->bufring != NULL) {
 572                                 buf_ring_free(pq->bufring, M_DEVBUF);
 573                         }
 574                 }
 575                 free(sc->queues, M_DEVBUF);
 576                 sc->queues = NULL;
 577         }
 578
 579         if (sc->iomem) {
 580                 bus_release_resource(dev, SYS_RES_IOPORT,
 581                                      PCIR_BAR(PTNETMAP_IO_PCI_BAR), sc->iomem);
 582                 sc->iomem = NULL;
 583         }
 584
 585         mtx_destroy(&sc->lock);
 586
 587         device_printf(dev, "%s() completed\n", __func__);
 588
 589         return (0);
 590 }
 591
 592 static int
 593 ptnet_suspend(device_t dev)
 594 {
 595         struct ptnet_softc *sc = device_get_softc(dev);
 596
 597         (void)sc;
 598
 599         return (0);
 600 }
 601
 602 static int
 603 ptnet_resume(device_t dev)
 604 {
 605         struct ptnet_softc *sc = device_get_softc(dev);
 606
 607         (void)sc;
 608
 609         return (0);
 610 }
 611
 612 static int
 613 ptnet_shutdown(device_t dev)
 614 {
 615         struct ptnet_softc *sc = device_get_softc(dev);
 616
 617         ptnet_device_shutdown(sc);
 618
 619         return (0);
 620 }
 621
 622 static int
 623 ptnet_irqs_init(struct ptnet_softc *sc)
 624 {
 625         int rid = PCIR_BAR(PTNETMAP_MSIX_PCI_BAR);
 626         int nvecs = sc->num_rings;
 627         device_t dev = sc->dev;
 628         int err = ENOSPC;
 629         int cpu_cur;
 630         int i;
 631
 632         if (pci_find_cap(dev, PCIY_MSIX, NULL) != 0)  {
 633                 device_printf(dev, "Could not find MSI-X capability\n");
 634                 return (ENXIO);
 635         }
 636
 637         sc->msix_mem = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
 638                                               &rid, RF_ACTIVE);
 639         if (sc->msix_mem == NULL) {
 640                 device_printf(dev, "Failed to allocate MSIX PCI BAR\n");
 641                 return (ENXIO);
 642         }
 643
 644         if (pci_msix_count(dev) < nvecs) {
 645                 device_printf(dev, "Not enough MSI-X vectors\n");
 646                 goto err_path;
 647         }
 648
 649         err = pci_alloc_msix(dev, &nvecs);
 650         if (err) {
 651                 device_printf(dev, "Failed to allocate MSI-X vectors\n");
 652                 goto err_path;
 653         }
 654
 655         for (i = 0; i < nvecs; i++) {
 656                 struct ptnet_queue *pq = sc->queues + i;
 657
 658                 rid = i + 1;
 659                 pq->irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
 660                                                  RF_ACTIVE);
 661                 if (pq->irq == NULL) {
 662                         device_printf(dev, "Failed to allocate interrupt "
 663                                            "for queue #%d\n", i);
 664                         err = ENOSPC;
 665                         goto err_path;
 666                 }
 667         }
 668
 669         cpu_cur = CPU_FIRST();
 670         for (i = 0; i < nvecs; i++) {
 671                 struct ptnet_queue *pq = sc->queues + i;
 672                 void (*handler)(void *) = ptnet_tx_intr;
 673
 674                 if (i >= sc->num_tx_rings) {
 675                         handler = ptnet_rx_intr;
 676                 }
 677                 err = bus_setup_intr(dev, pq->irq, INTR_TYPE_NET | INTR_MPSAFE,
 678                                      NULL /* intr_filter */, handler,
 679                                      pq, &pq->cookie);
 680                 if (err) {
 681                         device_printf(dev, "Failed to register intr handler "
 682                                            "for queue #%d\n", i);
 683                         goto err_path;
 684                 }
 685
 686                 bus_describe_intr(dev, pq->irq, pq->cookie, "q%d", i);
 687 #if 0
 688                 bus_bind_intr(sc->dev, pq->irq, cpu_cur);
 689 #endif
 690                 cpu_cur = CPU_NEXT(cpu_cur);
 691         }
 692
 693         device_printf(dev, "Allocated %d MSI-X vectors\n", nvecs);
 694
 695         cpu_cur = CPU_FIRST();
 696         for (i = 0; i < nvecs; i++) {
 697                 struct ptnet_queue *pq = sc->queues + i;
 698
 699                 if (i < sc->num_tx_rings)
 700                         TASK_INIT(&pq->task, 0, ptnet_tx_task, pq);
 701                 else
 702                         NET_TASK_INIT(&pq->task, 0, ptnet_rx_task, pq);
 703
 704                 pq->taskq = taskqueue_create_fast("ptnet_queue", M_NOWAIT,
 705                                         taskqueue_thread_enqueue, &pq->taskq);
 706                 taskqueue_start_threads(&pq->taskq, 1, PI_NET, "%s-pq-%d",
 707                                         device_get_nameunit(sc->dev), cpu_cur);
 708                 cpu_cur = CPU_NEXT(cpu_cur);
 709         }
 710
 711         return 0;
 712 err_path:
 713         ptnet_irqs_fini(sc);
 714         return err;
 715 }
 716
 717 static void
 718 ptnet_irqs_fini(struct ptnet_softc *sc)
 719 {
 720         device_t dev = sc->dev;
 721         int i;
 722
 723         for (i = 0; i < sc->num_rings; i++) {
 724                 struct ptnet_queue *pq = sc->queues + i;
 725
 726                 if (pq->taskq) {
 727                         taskqueue_free(pq->taskq);
 728                         pq->taskq = NULL;
 729                 }
 730
 731                 if (pq->cookie) {
 732                         bus_teardown_intr(dev, pq->irq, pq->cookie);
 733                         pq->cookie = NULL;
 734                 }
 735
 736                 if (pq->irq) {
 737                         bus_release_resource(dev, SYS_RES_IRQ, i + 1, pq->irq);
 738                         pq->irq = NULL;
 739                 }
 740         }
 741
 742         if (sc->msix_mem) {
 743                 pci_release_msi(dev);
 744
 745                 bus_release_resource(dev, SYS_RES_MEMORY,
 746                                      PCIR_BAR(PTNETMAP_MSIX_PCI_BAR),
 747                                      sc->msix_mem);
 748                 sc->msix_mem = NULL;
 749         }
 750 }
 751
 752 static void
 753 ptnet_init(void *opaque)
 754 {
 755         struct ptnet_softc *sc = opaque;
 756
 757         PTNET_CORE_LOCK(sc);
 758         ptnet_init_locked(sc);
 759         PTNET_CORE_UNLOCK(sc);
 760 }
 761
 762 static int
 763 ptnet_ioctl(if_t ifp, u_long cmd, caddr_t data)
 764 {
 765         struct ptnet_softc *sc = if_getsoftc(ifp);
 766         device_t dev = sc->dev;
 767         struct ifreq *ifr = (struct ifreq *)data;
 768         int mask __unused, err = 0;
 769
 770         switch (cmd) {
 771         case SIOCSIFFLAGS:
 772                 device_printf(dev, "SIOCSIFFLAGS %x\n", ifp->if_flags);
 773                 PTNET_CORE_LOCK(sc);
 774                 if (ifp->if_flags & IFF_UP) {
 775                         /* Network stack wants the iff to be up. */
 776                         err = ptnet_init_locked(sc);
 777                 } else {
 778                         /* Network stack wants the iff to be down. */
 779                         err = ptnet_stop(sc);
 780                 }
 781                 /* We don't need to do nothing to support IFF_PROMISC,
 782                  * since that is managed by the backend port. */
 783                 PTNET_CORE_UNLOCK(sc);
 784                 break;
 785
 786         case SIOCSIFCAP:
 787                 device_printf(dev, "SIOCSIFCAP %x %x\n",
 788                               ifr->ifr_reqcap, ifp->if_capenable);
 789                 mask = ifr->ifr_reqcap ^ ifp->if_capenable;
 790 #ifdef DEVICE_POLLING
 791                 if (mask & IFCAP_POLLING) {
 792                         struct ptnet_queue *pq;
 793                         int i;
 794
 795                         if (ifr->ifr_reqcap & IFCAP_POLLING) {
 796                                 err = ether_poll_register(ptnet_poll, ifp);
 797                                 if (err) {
 798                                         break;
 799                                 }
 800                                 /* Stop queues and sync with taskqueues. */
 801                                 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
 802                                 for (i = 0; i < sc->num_rings; i++) {
 803                                         pq = sc-> queues + i;
 804                                         /* Make sure the worker sees the
 805                                          * IFF_DRV_RUNNING down. */
 806                                         PTNET_Q_LOCK(pq);
 807                                         pq->atok->appl_need_kick = 0;
 808                                         PTNET_Q_UNLOCK(pq);
 809                                         /* Wait for rescheduling to finish. */
 810                                         if (pq->taskq) {
 811                                                 taskqueue_drain(pq->taskq,
 812                                                                 &pq->task);
 813                                         }
 814                                 }
 815                                 ifp->if_drv_flags |= IFF_DRV_RUNNING;
 816                         } else {
 817                                 err = ether_poll_deregister(ifp);
 818                                 for (i = 0; i < sc->num_rings; i++) {
 819                                         pq = sc-> queues + i;
 820                                         PTNET_Q_LOCK(pq);
 821                                         pq->atok->appl_need_kick = 1;
 822                                         PTNET_Q_UNLOCK(pq);
 823                                 }
 824                         }
 825                 }
 826 #endif  /* DEVICE_POLLING */
 827                 ifp->if_capenable = ifr->ifr_reqcap;
 828                 break;
 829
 830         case SIOCSIFMTU:
 831                 /* We support any reasonable MTU. */
 832                 if (ifr->ifr_mtu < ETHERMIN ||
 833                                 ifr->ifr_mtu > PTNET_MAX_PKT_SIZE) {
 834                         err = EINVAL;
 835                 } else {
 836                         PTNET_CORE_LOCK(sc);
 837                         ifp->if_mtu = ifr->ifr_mtu;
 838                         PTNET_CORE_UNLOCK(sc);
 839                 }
 840                 break;
 841
 842         case SIOCSIFMEDIA:
 843         case SIOCGIFMEDIA:
 844                 err = ifmedia_ioctl(ifp, ifr, &sc->media, cmd);
 845                 break;
 846
 847         default:
 848                 err = ether_ioctl(ifp, cmd, data);
 849                 break;
 850         }
 851
 852         return err;
 853 }
 854
 855 static int
 856 ptnet_init_locked(struct ptnet_softc *sc)
 857 {
 858         if_t ifp = sc->ifp;
 859         struct netmap_adapter *na_dr = &sc->ptna->dr.up;
 860         struct netmap_adapter *na_nm = &sc->ptna->hwup.up;
 861         unsigned int nm_buf_size;
 862         int ret;
 863
 864         if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
 865                 return 0; /* nothing to do */
 866         }
 867
 868         device_printf(sc->dev, "%s\n", __func__);
 869
 870         /* Translate offload capabilities according to if_capenable. */
 871         ifp->if_hwassist = 0;
 872         if (ifp->if_capenable & IFCAP_TXCSUM)
 873                 ifp->if_hwassist |= PTNET_CSUM_OFFLOAD;
 874         if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
 875                 ifp->if_hwassist |= PTNET_CSUM_OFFLOAD_IPV6;
 876         if (ifp->if_capenable & IFCAP_TSO4)
 877                 ifp->if_hwassist |= CSUM_IP_TSO;
 878         if (ifp->if_capenable & IFCAP_TSO6)
 879                 ifp->if_hwassist |= CSUM_IP6_TSO;
 880
 881         /*
 882          * Prepare the interface for netmap mode access.
 883          */
 884         netmap_update_config(na_dr);
 885
 886         ret = netmap_mem_finalize(na_dr->nm_mem, na_dr);
 887         if (ret) {
 888                 device_printf(sc->dev, "netmap_mem_finalize() failed\n");
 889                 return ret;
 890         }
 891
 892         if (sc->ptna->backend_users == 0) {
 893                 ret = ptnet_nm_krings_create(na_nm);
 894                 if (ret) {
 895                         device_printf(sc->dev, "ptnet_nm_krings_create() "
 896                                                "failed\n");
 897                         goto err_mem_finalize;
 898                 }
 899
 900                 ret = netmap_mem_rings_create(na_dr);
 901                 if (ret) {
 902                         device_printf(sc->dev, "netmap_mem_rings_create() "
 903                                                "failed\n");
 904                         goto err_rings_create;
 905                 }
 906
 907                 ret = netmap_mem_get_lut(na_dr->nm_mem, &na_dr->na_lut);
 908                 if (ret) {
 909                         device_printf(sc->dev, "netmap_mem_get_lut() "
 910                                                "failed\n");
 911                         goto err_get_lut;
 912                 }
 913         }
 914
 915         ret = ptnet_nm_register(na_dr, 1 /* on */);
 916         if (ret) {
 917                 goto err_register;
 918         }
 919
 920         nm_buf_size = NETMAP_BUF_SIZE(na_dr);
 921
 922         KASSERT(nm_buf_size > 0, ("Invalid netmap buffer size"));
 923         sc->min_tx_space = PTNET_MAX_PKT_SIZE / nm_buf_size + 2;
 924         device_printf(sc->dev, "%s: min_tx_space = %u\n", __func__,
 925                       sc->min_tx_space);
 926 #ifdef PTNETMAP_STATS
 927         callout_reset(&sc->tick, hz, ptnet_tick, sc);
 928 #endif
 929
 930         ifp->if_drv_flags |= IFF_DRV_RUNNING;
 931
 932         return 0;
 933
 934 err_register:
 935         memset(&na_dr->na_lut, 0, sizeof(na_dr->na_lut));
 936 err_get_lut:
 937         netmap_mem_rings_delete(na_dr);
 938 err_rings_create:
 939         ptnet_nm_krings_delete(na_nm);
 940 err_mem_finalize:
 941         netmap_mem_deref(na_dr->nm_mem, na_dr);
 942
 943         return ret;
 944 }
 945
 946 /* To be called under core lock. */
 947 static int
 948 ptnet_stop(struct ptnet_softc *sc)
 949 {
 950         if_t ifp = sc->ifp;
 951         struct netmap_adapter *na_dr = &sc->ptna->dr.up;
 952         struct netmap_adapter *na_nm = &sc->ptna->hwup.up;
 953         int i;
 954
 955         device_printf(sc->dev, "%s\n", __func__);
 956
 957         if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
 958                 return 0; /* nothing to do */
 959         }
 960
 961         /* Clear the driver-ready flag, and synchronize with all the queues,
 962          * so that after this loop we are sure nobody is working anymore with
 963          * the device. This scheme is taken from the vtnet driver. */
 964         ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
 965         callout_stop(&sc->tick);
 966         for (i = 0; i < sc->num_rings; i++) {
 967                 PTNET_Q_LOCK(sc->queues + i);
 968                 PTNET_Q_UNLOCK(sc->queues + i);
 969         }
 970
 971         ptnet_nm_register(na_dr, 0 /* off */);
 972
 973         if (sc->ptna->backend_users == 0) {
 974                 netmap_mem_rings_delete(na_dr);
 975                 ptnet_nm_krings_delete(na_nm);
 976         }
 977         netmap_mem_deref(na_dr->nm_mem, na_dr);
 978
 979         return 0;
 980 }
 981
 982 static void
 983 ptnet_qflush(if_t ifp)
 984 {
 985         struct ptnet_softc *sc = if_getsoftc(ifp);
 986         int i;
 987
 988         /* Flush all the bufrings and do the interface flush. */
 989         for (i = 0; i < sc->num_rings; i++) {
 990                 struct ptnet_queue *pq = sc->queues + i;
 991                 struct mbuf *m;
 992
 993                 PTNET_Q_LOCK(pq);
 994                 if (pq->bufring) {
 995                         while ((m = buf_ring_dequeue_sc(pq->bufring))) {
 996                                 m_freem(m);
 997                         }
 998                 }
 999                 PTNET_Q_UNLOCK(pq);
1000         }
1001
1002         if_qflush(ifp);
1003 }
1004
1005 static int
1006 ptnet_media_change(if_t ifp)
1007 {
1008         struct ptnet_softc *sc = if_getsoftc(ifp);
1009         struct ifmedia *ifm = &sc->media;
1010
1011         if (IFM_TYPE(ifm->ifm_media) != IFM_ETHER) {
1012                 return EINVAL;
1013         }
1014
1015         return 0;
1016 }
1017
1018 #if __FreeBSD_version >= 1100000
1019 static uint64_t
1020 ptnet_get_counter(if_t ifp, ift_counter cnt)
1021 {
1022         struct ptnet_softc *sc = if_getsoftc(ifp);
1023         struct ptnet_queue_stats stats[2];
1024         int i;
1025
1026         /* Accumulate statistics over the queues. */
1027         memset(stats, 0, sizeof(stats));
1028         for (i = 0; i < sc->num_rings; i++) {
1029                 struct ptnet_queue *pq = sc->queues + i;
1030                 int idx = (i < sc->num_tx_rings) ? 0 : 1;
1031
1032                 stats[idx].packets      += pq->stats.packets;
1033                 stats[idx].bytes        += pq->stats.bytes;
1034                 stats[idx].errors       += pq->stats.errors;
1035                 stats[idx].iqdrops      += pq->stats.iqdrops;
1036                 stats[idx].mcasts       += pq->stats.mcasts;
1037         }
1038
1039         switch (cnt) {
1040         case IFCOUNTER_IPACKETS:
1041                 return (stats[1].packets);
1042         case IFCOUNTER_IQDROPS:
1043                 return (stats[1].iqdrops);
1044         case IFCOUNTER_IERRORS:
1045                 return (stats[1].errors);
1046         case IFCOUNTER_OPACKETS:
1047                 return (stats[0].packets);
1048         case IFCOUNTER_OBYTES:
1049                 return (stats[0].bytes);
1050         case IFCOUNTER_OMCASTS:
1051                 return (stats[0].mcasts);
1052         default:
1053                 return (if_get_counter_default(ifp, cnt));
1054         }
1055 }
1056 #endif
1057
1058
1059 #ifdef PTNETMAP_STATS
1060 /* Called under core lock. */
1061 static void
1062 ptnet_tick(void *opaque)
1063 {
1064         struct ptnet_softc *sc = opaque;
1065         int i;
1066
1067         for (i = 0; i < sc->num_rings; i++) {
1068                 struct ptnet_queue *pq = sc->queues + i;
1069                 struct ptnet_queue_stats cur = pq->stats;
1070                 struct timeval now;
1071                 unsigned int delta;
1072
1073                 microtime(&now);
1074                 delta = now.tv_usec - sc->last_ts.tv_usec +
1075                         (now.tv_sec - sc->last_ts.tv_sec) * 1000000;
1076                 delta /= 1000; /* in milliseconds */
1077
1078                 if (delta == 0)
1079                         continue;
1080
1081                 device_printf(sc->dev, "#%d[%u ms]:pkts %lu, kicks %lu, "
1082                               "intr %lu\n", i, delta,
1083                               (cur.packets - pq->last_stats.packets),
1084                               (cur.kicks - pq->last_stats.kicks),
1085                               (cur.intrs - pq->last_stats.intrs));
1086                 pq->last_stats = cur;
1087         }
1088         microtime(&sc->last_ts);
1089         callout_schedule(&sc->tick, hz);
1090 }
1091 #endif /* PTNETMAP_STATS */
1092
1093 static void
1094 ptnet_media_status(if_t ifp, struct ifmediareq *ifmr)
1095 {
1096         /* We are always active, as the backend netmap port is
1097          * always open in netmap mode. */
1098         ifmr->ifm_status = IFM_AVALID | IFM_ACTIVE;
1099         ifmr->ifm_active = IFM_ETHER | IFM_10G_T | IFM_FDX;
1100 }
1101
1102 static uint32_t
1103 ptnet_nm_ptctl(struct ptnet_softc *sc, uint32_t cmd)
1104 {
1105         /*
1106          * Write a command and read back error status,
1107          * with zero meaning success.
1108          */
1109         bus_write_4(sc->iomem, PTNET_IO_PTCTL, cmd);
1110         return bus_read_4(sc->iomem, PTNET_IO_PTCTL);
1111 }
1112
1113 static int
1114 ptnet_nm_config(struct netmap_adapter *na, struct nm_config_info *info)
1115 {
1116         struct ptnet_softc *sc = if_getsoftc(na->ifp);
1117
1118         info->num_tx_rings = bus_read_4(sc->iomem, PTNET_IO_NUM_TX_RINGS);
1119         info->num_rx_rings = bus_read_4(sc->iomem, PTNET_IO_NUM_RX_RINGS);
1120         info->num_tx_descs = bus_read_4(sc->iomem, PTNET_IO_NUM_TX_SLOTS);
1121         info->num_rx_descs = bus_read_4(sc->iomem, PTNET_IO_NUM_RX_SLOTS);
1122         info->rx_buf_maxsize = NETMAP_BUF_SIZE(na);
1123
1124         device_printf(sc->dev, "txr %u, rxr %u, txd %u, rxd %u, rxbufsz %u\n",
1125                         info->num_tx_rings, info->num_rx_rings,
1126                         info->num_tx_descs, info->num_rx_descs,
1127                         info->rx_buf_maxsize);
1128
1129         return 0;
1130 }
1131
1132 static void
1133 ptnet_sync_from_csb(struct ptnet_softc *sc, struct netmap_adapter *na)
1134 {
1135         int i;
1136
1137         /* Sync krings from the host, reading from
1138          * CSB. */
1139         for (i = 0; i < sc->num_rings; i++) {
1140                 struct nm_csb_atok *atok = sc->queues[i].atok;
1141                 struct nm_csb_ktoa *ktoa = sc->queues[i].ktoa;
1142                 struct netmap_kring *kring;
1143
1144                 if (i < na->num_tx_rings) {
1145                         kring = na->tx_rings[i];
1146                 } else {
1147                         kring = na->rx_rings[i - na->num_tx_rings];
1148                 }
1149                 kring->rhead = kring->ring->head = atok->head;
1150                 kring->rcur = kring->ring->cur = atok->cur;
1151                 kring->nr_hwcur = ktoa->hwcur;
1152                 kring->nr_hwtail = kring->rtail =
1153                         kring->ring->tail = ktoa->hwtail;
1154
1155                 nm_prdis("%d,%d: csb {hc %u h %u c %u ht %u}", t, i,
1156                    ktoa->hwcur, atok->head, atok->cur,
1157                    ktoa->hwtail);
1158                 nm_prdis("%d,%d: kring {hc %u rh %u rc %u h %u c %u ht %u rt %u t %u}",
1159                    t, i, kring->nr_hwcur, kring->rhead, kring->rcur,
1160                    kring->ring->head, kring->ring->cur, kring->nr_hwtail,
1161                    kring->rtail, kring->ring->tail);
1162         }
1163 }
1164
1165 static void
1166 ptnet_update_vnet_hdr(struct ptnet_softc *sc)
1167 {
1168         unsigned int wanted_hdr_len = ptnet_vnet_hdr ? PTNET_HDR_SIZE : 0;
1169
1170         bus_write_4(sc->iomem, PTNET_IO_VNET_HDR_LEN, wanted_hdr_len);
1171         sc->vnet_hdr_len = bus_read_4(sc->iomem, PTNET_IO_VNET_HDR_LEN);
1172         sc->ptna->hwup.up.virt_hdr_len = sc->vnet_hdr_len;
1173 }
1174
1175 static int
1176 ptnet_nm_register(struct netmap_adapter *na, int onoff)
1177 {
1178         /* device-specific */
1179         if_t ifp = na->ifp;
1180         struct ptnet_softc *sc = if_getsoftc(ifp);
1181         int native = (na == &sc->ptna->hwup.up);
1182         struct ptnet_queue *pq;
1183         int ret = 0;
1184         int i;
1185
1186         if (!onoff) {
1187                 sc->ptna->backend_users--;
1188         }
1189
1190         /* If this is the last netmap client, guest interrupt enable flags may
1191          * be in arbitrary state. Since these flags are going to be used also
1192          * by the netdevice driver, we have to make sure to start with
1193          * notifications enabled. Also, schedule NAPI to flush pending packets
1194          * in the RX rings, since we will not receive further interrupts
1195          * until these will be processed. */
1196         if (native && !onoff && na->active_fds == 0) {
1197                 nm_prinf("Exit netmap mode, re-enable interrupts");
1198                 for (i = 0; i < sc->num_rings; i++) {
1199                         pq = sc->queues + i;
1200                         pq->atok->appl_need_kick = 1;
1201                 }
1202         }
1203
1204         if (onoff) {
1205                 if (sc->ptna->backend_users == 0) {
1206                         /* Initialize notification enable fields in the CSB. */
1207                         for (i = 0; i < sc->num_rings; i++) {
1208                                 pq = sc->queues + i;
1209                                 pq->ktoa->kern_need_kick = 1;
1210                                 pq->atok->appl_need_kick =
1211                                         (!(ifp->if_capenable & IFCAP_POLLING)
1212                                                 && i >= sc->num_tx_rings);
1213                         }
1214
1215                         /* Set the virtio-net header length. */
1216                         ptnet_update_vnet_hdr(sc);
1217
1218                         /* Make sure the host adapter passed through is ready
1219                          * for txsync/rxsync. */
1220                         ret = ptnet_nm_ptctl(sc, PTNETMAP_PTCTL_CREATE);
1221                         if (ret) {
1222                                 return ret;
1223                         }
1224
1225                         /* Align the guest krings and rings to the state stored
1226                          * in the CSB. */
1227                         ptnet_sync_from_csb(sc, na);
1228                 }
1229
1230                 /* If not native, don't call nm_set_native_flags, since we don't want
1231                  * to replace if_transmit method, nor set NAF_NETMAP_ON */
1232                 if (native) {
1233                         netmap_krings_mode_commit(na, onoff);
1234                         nm_set_native_flags(na);
1235                 }
1236
1237         } else {
1238                 if (native) {
1239                         nm_clear_native_flags(na);
1240                         netmap_krings_mode_commit(na, onoff);
1241                 }
1242
1243                 if (sc->ptna->backend_users == 0) {
1244                         ret = ptnet_nm_ptctl(sc, PTNETMAP_PTCTL_DELETE);
1245                 }
1246         }
1247
1248         if (onoff) {
1249                 sc->ptna->backend_users++;
1250         }
1251
1252         return ret;
1253 }
1254
1255 static int
1256 ptnet_nm_txsync(struct netmap_kring *kring, int flags)
1257 {
1258         struct ptnet_softc *sc = if_getsoftc(kring->na->ifp);
1259         struct ptnet_queue *pq = sc->queues + kring->ring_id;
1260         bool notify;
1261
1262         notify = netmap_pt_guest_txsync(pq->atok, pq->ktoa, kring, flags);
1263         if (notify) {
1264                 ptnet_kick(pq);
1265         }
1266
1267         return 0;
1268 }
1269
1270 static int
1271 ptnet_nm_rxsync(struct netmap_kring *kring, int flags)
1272 {
1273         struct ptnet_softc *sc = if_getsoftc(kring->na->ifp);
1274         struct ptnet_queue *pq = sc->rxqueues + kring->ring_id;
1275         bool notify;
1276
1277         notify = netmap_pt_guest_rxsync(pq->atok, pq->ktoa, kring, flags);
1278         if (notify) {
1279                 ptnet_kick(pq);
1280         }
1281
1282         return 0;
1283 }
1284
1285 static void
1286 ptnet_nm_intr(struct netmap_adapter *na, int onoff)
1287 {
1288         struct ptnet_softc *sc = if_getsoftc(na->ifp);
1289         int i;
1290
1291         for (i = 0; i < sc->num_rings; i++) {
1292                 struct ptnet_queue *pq = sc->queues + i;
1293                 pq->atok->appl_need_kick = onoff;
1294         }
1295 }
1296
1297 static void
1298 ptnet_tx_intr(void *opaque)
1299 {
1300         struct ptnet_queue *pq = opaque;
1301         struct ptnet_softc *sc = pq->sc;
1302
1303         DBG(device_printf(sc->dev, "Tx interrupt #%d\n", pq->kring_id));
1304 #ifdef PTNETMAP_STATS
1305         pq->stats.intrs ++;
1306 #endif /* PTNETMAP_STATS */
1307
1308         if (netmap_tx_irq(sc->ifp, pq->kring_id) != NM_IRQ_PASS) {
1309                 return;
1310         }
1311
1312         /* Schedule the tasqueue to flush process transmissions requests.
1313          * However, vtnet, if_em and if_igb just call ptnet_transmit() here,
1314          * at least when using MSI-X interrupts. The if_em driver, instead
1315          * schedule taskqueue when using legacy interrupts. */
1316         taskqueue_enqueue(pq->taskq, &pq->task);
1317 }
1318
1319 static void
1320 ptnet_rx_intr(void *opaque)
1321 {
1322         struct ptnet_queue *pq = opaque;
1323         struct ptnet_softc *sc = pq->sc;
1324         unsigned int unused;
1325
1326         DBG(device_printf(sc->dev, "Rx interrupt #%d\n", pq->kring_id));
1327 #ifdef PTNETMAP_STATS
1328         pq->stats.intrs ++;
1329 #endif /* PTNETMAP_STATS */
1330
1331         if (netmap_rx_irq(sc->ifp, pq->kring_id, &unused) != NM_IRQ_PASS) {
1332                 return;
1333         }
1334
1335         /* Like vtnet, if_igb and if_em drivers when using MSI-X interrupts,
1336          * receive-side processing is executed directly in the interrupt
1337          * service routine. Alternatively, we may schedule the taskqueue. */
1338         ptnet_rx_eof(pq, PTNET_RX_BUDGET, true);
1339 }
1340
1341 static void
1342 ptnet_vlan_tag_remove(struct mbuf *m)
1343 {
1344         struct ether_vlan_header *evh;
1345
1346         evh = mtod(m, struct ether_vlan_header *);
1347         m->m_pkthdr.ether_vtag = ntohs(evh->evl_tag);
1348         m->m_flags |= M_VLANTAG;
1349
1350         /* Strip the 802.1Q header. */
1351         bcopy((char *) evh, (char *) evh + ETHER_VLAN_ENCAP_LEN,
1352             ETHER_HDR_LEN - ETHER_TYPE_LEN);
1353         m_adj(m, ETHER_VLAN_ENCAP_LEN);
1354 }
1355
1356 static void
1357 ptnet_ring_update(struct ptnet_queue *pq, struct netmap_kring *kring,
1358                   unsigned int head, unsigned int sync_flags)
1359 {
1360         struct netmap_ring *ring = kring->ring;
1361         struct nm_csb_atok *atok = pq->atok;
1362         struct nm_csb_ktoa *ktoa = pq->ktoa;
1363
1364         /* Some packets have been pushed to the netmap ring. We have
1365          * to tell the host to process the new packets, updating cur
1366          * and head in the CSB. */
1367         ring->head = ring->cur = head;
1368
1369         /* Mimic nm_txsync_prologue/nm_rxsync_prologue. */
1370         kring->rcur = kring->rhead = head;
1371
1372         nm_sync_kloop_appl_write(atok, kring->rcur, kring->rhead);
1373
1374         /* Kick the host if needed. */
1375         if (NM_ACCESS_ONCE(ktoa->kern_need_kick)) {
1376                 atok->sync_flags = sync_flags;
1377                 ptnet_kick(pq);
1378         }
1379 }
1380
1381 #define PTNET_TX_NOSPACE(_h, _k, _min)  \
1382         ((((_h) < (_k)->rtail) ? 0 : (_k)->nkr_num_slots) + \
1383                 (_k)->rtail - (_h)) < (_min)
1384
1385 /* This function may be called by the network stack, or by
1386  * by the taskqueue thread. */
1387 static int
1388 ptnet_drain_transmit_queue(struct ptnet_queue *pq, unsigned int budget,
1389                            bool may_resched)
1390 {
1391         struct ptnet_softc *sc = pq->sc;
1392         bool have_vnet_hdr = sc->vnet_hdr_len;
1393         struct netmap_adapter *na = &sc->ptna->dr.up;
1394         if_t ifp = sc->ifp;
1395         unsigned int batch_count = 0;
1396         struct nm_csb_atok *atok;
1397         struct nm_csb_ktoa *ktoa;
1398         struct netmap_kring *kring;
1399         struct netmap_ring *ring;
1400         struct netmap_slot *slot;
1401         unsigned int count = 0;
1402         unsigned int minspace;
1403         unsigned int head;
1404         unsigned int lim;
1405         struct mbuf *mhead;
1406         struct mbuf *mf;
1407         int nmbuf_bytes;
1408         uint8_t *nmbuf;
1409
1410         if (!PTNET_Q_TRYLOCK(pq)) {
1411                 /* We failed to acquire the lock, schedule the taskqueue. */
1412                 nm_prlim(1, "Deferring TX work");
1413                 if (may_resched) {
1414                         taskqueue_enqueue(pq->taskq, &pq->task);
1415                 }
1416
1417                 return 0;
1418         }
1419
1420         if (unlikely(!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
1421                 PTNET_Q_UNLOCK(pq);
1422                 nm_prlim(1, "Interface is down");
1423                 return ENETDOWN;
1424         }
1425
1426         atok = pq->atok;
1427         ktoa = pq->ktoa;
1428         kring = na->tx_rings[pq->kring_id];
1429         ring = kring->ring;
1430         lim = kring->nkr_num_slots - 1;
1431         head = ring->head;
1432         minspace = sc->min_tx_space;
1433
1434         while (count < budget) {
1435                 if (PTNET_TX_NOSPACE(head, kring, minspace)) {
1436                         /* We ran out of slot, let's see if the host has
1437                          * freed up some, by reading hwcur and hwtail from
1438                          * the CSB. */
1439                         ptnet_sync_tail(ktoa, kring);
1440
1441                         if (PTNET_TX_NOSPACE(head, kring, minspace)) {
1442                                 /* Still no slots available. Reactivate the
1443                                  * interrupts so that we can be notified
1444                                  * when some free slots are made available by
1445                                  * the host. */
1446                                 atok->appl_need_kick = 1;
1447
1448                                 /* Double check. We need a full barrier to
1449                                  * prevent the store to atok->appl_need_kick
1450                                  * to be reordered with the load from
1451                                  * ktoa->hwcur and ktoa->hwtail (store-load
1452                                  * barrier). */
1453                                 nm_stld_barrier();
1454                                 ptnet_sync_tail(ktoa, kring);
1455                                 if (likely(PTNET_TX_NOSPACE(head, kring,
1456                                                             minspace))) {
1457                                         break;
1458                                 }
1459
1460                                 nm_prlim(1, "Found more slots by doublecheck");
1461                                 /* More slots were freed before reactivating
1462                                  * the interrupts. */
1463                                 atok->appl_need_kick = 0;
1464                         }
1465                 }
1466
1467                 mhead = drbr_peek(ifp, pq->bufring);
1468                 if (!mhead) {
1469                         break;
1470                 }
1471
1472                 /* Initialize transmission state variables. */
1473                 slot = ring->slot + head;
1474                 nmbuf = NMB(na, slot);
1475                 nmbuf_bytes = 0;
1476
1477                 /* If needed, prepare the virtio-net header at the beginning
1478                  * of the first slot. */
1479                 if (have_vnet_hdr) {
1480                         struct virtio_net_hdr *vh =
1481                                         (struct virtio_net_hdr *)nmbuf;
1482
1483                         /* For performance, we could replace this memset() with
1484                          * two 8-bytes-wide writes. */
1485                         memset(nmbuf, 0, PTNET_HDR_SIZE);
1486                         if (mhead->m_pkthdr.csum_flags & PTNET_ALL_OFFLOAD) {
1487                                 mhead = virtio_net_tx_offload(ifp, mhead, false,
1488                                                          vh);
1489                                 if (unlikely(!mhead)) {
1490                                         /* Packet dropped because errors
1491                                          * occurred while preparing the vnet
1492                                          * header. Let's go ahead with the next
1493                                          * packet. */
1494                                         pq->stats.errors ++;
1495                                         drbr_advance(ifp, pq->bufring);
1496                                         continue;
1497                                 }
1498                         }
1499                         nm_prdis(1, "%s: [csum_flags %lX] vnet hdr: flags %x "
1500                               "csum_start %u csum_ofs %u hdr_len = %u "
1501                               "gso_size %u gso_type %x", __func__,
1502                               mhead->m_pkthdr.csum_flags, vh->flags,
1503                               vh->csum_start, vh->csum_offset, vh->hdr_len,
1504                               vh->gso_size, vh->gso_type);
1505
1506                         nmbuf += PTNET_HDR_SIZE;
1507                         nmbuf_bytes += PTNET_HDR_SIZE;
1508                 }
1509
1510                 for (mf = mhead; mf; mf = mf->m_next) {
1511                         uint8_t *mdata = mf->m_data;
1512                         int mlen = mf->m_len;
1513
1514                         for (;;) {
1515                                 int copy = NETMAP_BUF_SIZE(na) - nmbuf_bytes;
1516
1517                                 if (mlen < copy) {
1518                                         copy = mlen;
1519                                 }
1520                                 memcpy(nmbuf, mdata, copy);
1521
1522                                 mdata += copy;
1523                                 mlen -= copy;
1524                                 nmbuf += copy;
1525                                 nmbuf_bytes += copy;
1526
1527                                 if (!mlen) {
1528                                         break;
1529                                 }
1530
1531                                 slot->len = nmbuf_bytes;
1532                                 slot->flags = NS_MOREFRAG;
1533
1534                                 head = nm_next(head, lim);
1535                                 KASSERT(head != ring->tail,
1536                                         ("Unexpectedly run out of TX space"));
1537                                 slot = ring->slot + head;
1538                                 nmbuf = NMB(na, slot);
1539                                 nmbuf_bytes = 0;
1540                         }
1541                 }
1542
1543                 /* Complete last slot and update head. */
1544                 slot->len = nmbuf_bytes;
1545                 slot->flags = 0;
1546                 head = nm_next(head, lim);
1547
1548                 /* Consume the packet just processed. */
1549                 drbr_advance(ifp, pq->bufring);
1550
1551                 /* Copy the packet to listeners. */
1552                 ETHER_BPF_MTAP(ifp, mhead);
1553
1554                 pq->stats.packets ++;
1555                 pq->stats.bytes += mhead->m_pkthdr.len;
1556                 if (mhead->m_flags & M_MCAST) {
1557                         pq->stats.mcasts ++;
1558                 }
1559
1560                 m_freem(mhead);
1561
1562                 count ++;
1563                 if (++batch_count == PTNET_TX_BATCH) {
1564                         ptnet_ring_update(pq, kring, head, NAF_FORCE_RECLAIM);
1565                         batch_count = 0;
1566                 }
1567         }
1568
1569         if (batch_count) {
1570                 ptnet_ring_update(pq, kring, head, NAF_FORCE_RECLAIM);
1571         }
1572
1573         if (count >= budget && may_resched) {
1574                 DBG(nm_prlim(1, "out of budget: resched, %d mbufs pending\n",
1575                                         drbr_inuse(ifp, pq->bufring)));
1576                 taskqueue_enqueue(pq->taskq, &pq->task);
1577         }
1578
1579         PTNET_Q_UNLOCK(pq);
1580
1581         return count;
1582 }
1583
1584 static int
1585 ptnet_transmit(if_t ifp, struct mbuf *m)
1586 {
1587         struct ptnet_softc *sc = if_getsoftc(ifp);
1588         struct ptnet_queue *pq;
1589         unsigned int queue_idx;
1590         int err;
1591
1592         DBG(device_printf(sc->dev, "transmit %p\n", m));
1593
1594         /* Insert 802.1Q header if needed. */
1595         if (m->m_flags & M_VLANTAG) {
1596                 m = ether_vlanencap(m, m->m_pkthdr.ether_vtag);
1597                 if (m == NULL) {
1598                         return ENOBUFS;
1599                 }
1600                 m->m_flags &= ~M_VLANTAG;
1601         }
1602
1603         /* Get the flow-id if available. */
1604         queue_idx = (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE) ?
1605                     m->m_pkthdr.flowid : curcpu;
1606
1607         if (unlikely(queue_idx >= sc->num_tx_rings)) {
1608                 queue_idx %= sc->num_tx_rings;
1609         }
1610
1611         pq = sc->queues + queue_idx;
1612
1613         err = drbr_enqueue(ifp, pq->bufring, m);
1614         if (err) {
1615                 /* ENOBUFS when the bufring is full */
1616                 nm_prlim(1, "%s: drbr_enqueue() failed %d\n",
1617                         __func__, err);
1618                 pq->stats.errors ++;
1619                 return err;
1620         }
1621
1622         if (ifp->if_capenable & IFCAP_POLLING) {
1623                 /* If polling is on, the transmit queues will be
1624                  * drained by the poller. */
1625                 return 0;
1626         }
1627
1628         err = ptnet_drain_transmit_queue(pq, PTNET_TX_BUDGET, true);
1629
1630         return (err < 0) ? err : 0;
1631 }
1632
1633 static unsigned int
1634 ptnet_rx_discard(struct netmap_kring *kring, unsigned int head)
1635 {
1636         struct netmap_ring *ring = kring->ring;
1637         struct netmap_slot *slot = ring->slot + head;
1638
1639         for (;;) {
1640                 head = nm_next(head, kring->nkr_num_slots - 1);
1641                 if (!(slot->flags & NS_MOREFRAG) || head == ring->tail) {
1642                         break;
1643                 }
1644                 slot = ring->slot + head;
1645         }
1646
1647         return head;
1648 }
1649
1650 static inline struct mbuf *
1651 ptnet_rx_slot(struct mbuf *mtail, uint8_t *nmbuf, unsigned int nmbuf_len)
1652 {
1653         uint8_t *mdata = mtod(mtail, uint8_t *) + mtail->m_len;
1654
1655         do {
1656                 unsigned int copy;
1657
1658                 if (mtail->m_len == MCLBYTES) {
1659                         struct mbuf *mf;
1660
1661                         mf = m_getcl(M_NOWAIT, MT_DATA, 0);
1662                         if (unlikely(!mf)) {
1663                                 return NULL;
1664                         }
1665
1666                         mtail->m_next = mf;
1667                         mtail = mf;
1668                         mdata = mtod(mtail, uint8_t *);
1669                         mtail->m_len = 0;
1670                 }
1671
1672                 copy = MCLBYTES - mtail->m_len;
1673                 if (nmbuf_len < copy) {
1674                         copy = nmbuf_len;
1675                 }
1676
1677                 memcpy(mdata, nmbuf, copy);
1678
1679                 nmbuf += copy;
1680                 nmbuf_len -= copy;
1681                 mdata += copy;
1682                 mtail->m_len += copy;
1683         } while (nmbuf_len);
1684
1685         return mtail;
1686 }
1687
1688 static int
1689 ptnet_rx_eof(struct ptnet_queue *pq, unsigned int budget, bool may_resched)
1690 {
1691         struct ptnet_softc *sc = pq->sc;
1692         bool have_vnet_hdr = sc->vnet_hdr_len;
1693         struct nm_csb_atok *atok = pq->atok;
1694         struct nm_csb_ktoa *ktoa = pq->ktoa;
1695         struct netmap_adapter *na = &sc->ptna->dr.up;
1696         struct netmap_kring *kring = na->rx_rings[pq->kring_id];
1697         struct netmap_ring *ring = kring->ring;
1698         unsigned int const lim = kring->nkr_num_slots - 1;
1699         unsigned int batch_count = 0;
1700         if_t ifp = sc->ifp;
1701         unsigned int count = 0;
1702         uint32_t head;
1703
1704         PTNET_Q_LOCK(pq);
1705
1706         if (unlikely(!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
1707                 goto unlock;
1708         }
1709
1710         kring->nr_kflags &= ~NKR_PENDINTR;
1711
1712         head = ring->head;
1713         while (count < budget) {
1714                 uint32_t prev_head = head;
1715                 struct mbuf *mhead, *mtail;
1716                 struct virtio_net_hdr *vh;
1717                 struct netmap_slot *slot;
1718                 unsigned int nmbuf_len;
1719                 uint8_t *nmbuf;
1720                 int deliver = 1; /* the mbuf to the network stack. */
1721 host_sync:
1722                 if (head == ring->tail) {
1723                         /* We ran out of slot, let's see if the host has
1724                          * added some, by reading hwcur and hwtail from
1725                          * the CSB. */
1726                         ptnet_sync_tail(ktoa, kring);
1727
1728                         if (head == ring->tail) {
1729                                 /* Still no slots available. Reactivate
1730                                  * interrupts as they were disabled by the
1731                                  * host thread right before issuing the
1732                                  * last interrupt. */
1733                                 atok->appl_need_kick = 1;
1734
1735                                 /* Double check for more completed RX slots.
1736                                  * We need a full barrier to prevent the store
1737                                  * to atok->appl_need_kick to be reordered with
1738                                  * the load from ktoa->hwcur and ktoa->hwtail
1739                                  * (store-load barrier). */
1740                                 nm_stld_barrier();
1741                                 ptnet_sync_tail(ktoa, kring);
1742                                 if (likely(head == ring->tail)) {
1743                                         break;
1744                                 }
1745                                 atok->appl_need_kick = 0;
1746                         }
1747                 }
1748
1749                 /* Initialize ring state variables, possibly grabbing the
1750                  * virtio-net header. */
1751                 slot = ring->slot + head;
1752                 nmbuf = NMB(na, slot);
1753                 nmbuf_len = slot->len;
1754
1755                 vh = (struct virtio_net_hdr *)nmbuf;
1756                 if (have_vnet_hdr) {
1757                         if (unlikely(nmbuf_len < PTNET_HDR_SIZE)) {
1758                                 /* There is no good reason why host should
1759                                  * put the header in multiple netmap slots.
1760                                  * If this is the case, discard. */
1761                                 nm_prlim(1, "Fragmented vnet-hdr: dropping");
1762                                 head = ptnet_rx_discard(kring, head);
1763                                 pq->stats.iqdrops ++;
1764                                 deliver = 0;
1765                                 goto skip;
1766                         }
1767                         nm_prdis(1, "%s: vnet hdr: flags %x csum_start %u "
1768                               "csum_ofs %u hdr_len = %u gso_size %u "
1769                               "gso_type %x", __func__, vh->flags,
1770                               vh->csum_start, vh->csum_offset, vh->hdr_len,
1771                               vh->gso_size, vh->gso_type);
1772                         nmbuf += PTNET_HDR_SIZE;
1773                         nmbuf_len -= PTNET_HDR_SIZE;
1774                 }
1775
1776                 /* Allocate the head of a new mbuf chain.
1777                  * We use m_getcl() to allocate an mbuf with standard cluster
1778                  * size (MCLBYTES). In the future we could use m_getjcl()
1779                  * to choose different sizes. */
1780                 mhead = mtail = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
1781                 if (unlikely(mhead == NULL)) {
1782                         device_printf(sc->dev, "%s: failed to allocate mbuf "
1783                                       "head\n", __func__);
1784                         pq->stats.errors ++;
1785                         break;
1786                 }
1787
1788                 /* Initialize the mbuf state variables. */
1789                 mhead->m_pkthdr.len = nmbuf_len;
1790                 mtail->m_len = 0;
1791
1792                 /* Scan all the netmap slots containing the current packet. */
1793                 for (;;) {
1794                         DBG(device_printf(sc->dev, "%s: h %u t %u rcv frag "
1795                                           "len %u, flags %u\n", __func__,
1796                                           head, ring->tail, slot->len,
1797                                           slot->flags));
1798
1799                         mtail = ptnet_rx_slot(mtail, nmbuf, nmbuf_len);
1800                         if (unlikely(!mtail)) {
1801                                 /* Ouch. We ran out of memory while processing
1802                                  * a packet. We have to restore the previous
1803                                  * head position, free the mbuf chain, and
1804                                  * schedule the taskqueue to give the packet
1805                                  * another chance. */
1806                                 device_printf(sc->dev, "%s: failed to allocate"
1807                                         " mbuf frag, reset head %u --> %u\n",
1808                                         __func__, head, prev_head);
1809                                 head = prev_head;
1810                                 m_freem(mhead);
1811                                 pq->stats.errors ++;
1812                                 if (may_resched) {
1813                                         taskqueue_enqueue(pq->taskq,
1814                                                           &pq->task);
1815                                 }
1816                                 goto escape;
1817                         }
1818
1819                         /* We have to increment head irrespective of the
1820                          * NS_MOREFRAG being set or not. */
1821                         head = nm_next(head, lim);
1822
1823                         if (!(slot->flags & NS_MOREFRAG)) {
1824                                 break;
1825                         }
1826
1827                         if (unlikely(head == ring->tail)) {
1828                                 /* The very last slot prepared by the host has
1829                                  * the NS_MOREFRAG set. Drop it and continue
1830                                  * the outer cycle (to do the double-check). */
1831                                 nm_prlim(1, "Incomplete packet: dropping");
1832                                 m_freem(mhead);
1833                                 pq->stats.iqdrops ++;
1834                                 goto host_sync;
1835                         }
1836
1837                         slot = ring->slot + head;
1838                         nmbuf = NMB(na, slot);
1839                         nmbuf_len = slot->len;
1840                         mhead->m_pkthdr.len += nmbuf_len;
1841                 }
1842
1843                 mhead->m_pkthdr.rcvif = ifp;
1844                 mhead->m_pkthdr.csum_flags = 0;
1845
1846                 /* Store the queue idx in the packet header. */
1847                 mhead->m_pkthdr.flowid = pq->kring_id;
1848                 M_HASHTYPE_SET(mhead, M_HASHTYPE_OPAQUE);
1849
1850                 if (ifp->if_capenable & IFCAP_VLAN_HWTAGGING) {
1851                         struct ether_header *eh;
1852
1853                         eh = mtod(mhead, struct ether_header *);
1854                         if (eh->ether_type == htons(ETHERTYPE_VLAN)) {
1855                                 ptnet_vlan_tag_remove(mhead);
1856                                 /*
1857                                  * With the 802.1Q header removed, update the
1858                                  * checksum starting location accordingly.
1859                                  */
1860                                 if (vh->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
1861                                         vh->csum_start -= ETHER_VLAN_ENCAP_LEN;
1862                         }
1863                 }
1864
1865                 if (unlikely(have_vnet_hdr && virtio_net_rx_csum(mhead, vh))) {
1866                         m_freem(mhead);
1867                         nm_prlim(1, "Csum offload error: dropping");
1868                         pq->stats.iqdrops ++;
1869                         deliver = 0;
1870                 }
1871
1872 skip:
1873                 count ++;
1874                 if (++batch_count >= PTNET_RX_BATCH) {
1875                         /* Some packets have been (or will be) pushed to the network
1876                          * stack. We need to update the CSB to tell the host about
1877                          * the new ring->cur and ring->head (RX buffer refill). */
1878                         ptnet_ring_update(pq, kring, head, NAF_FORCE_READ);
1879                         batch_count = 0;
1880                 }
1881
1882                 if (likely(deliver))  {
1883                         pq->stats.packets ++;
1884                         pq->stats.bytes += mhead->m_pkthdr.len;
1885
1886                         PTNET_Q_UNLOCK(pq);
1887                         (*ifp->if_input)(ifp, mhead);
1888                         PTNET_Q_LOCK(pq);
1889                         /* The ring->head index (and related indices) are
1890                          * updated under pq lock by ptnet_ring_update().
1891                          * Since we dropped the lock to call if_input(), we
1892                          * must reload ring->head and restart processing the
1893                          * ring from there. */
1894                         head = ring->head;
1895
1896                         if (unlikely(!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
1897                                 /* The interface has gone down while we didn't
1898                                  * have the lock. Stop any processing and exit. */
1899                                 goto unlock;
1900                         }
1901                 }
1902         }
1903 escape:
1904         if (batch_count) {
1905                 ptnet_ring_update(pq, kring, head, NAF_FORCE_READ);
1906
1907         }
1908
1909         if (count >= budget && may_resched) {
1910                 /* If we ran out of budget or the double-check found new
1911                  * slots to process, schedule the taskqueue. */
1912                 DBG(nm_prlim(1, "out of budget: resched h %u t %u\n",
1913                                         head, ring->tail));
1914                 taskqueue_enqueue(pq->taskq, &pq->task);
1915         }
1916 unlock:
1917         PTNET_Q_UNLOCK(pq);
1918
1919         return count;
1920 }
1921
1922 static void
1923 ptnet_rx_task(void *context, int pending)
1924 {
1925         struct ptnet_queue *pq = context;
1926
1927         DBG(nm_prlim(1, "%s: pq #%u\n", __func__, pq->kring_id));
1928         ptnet_rx_eof(pq, PTNET_RX_BUDGET, true);
1929 }
1930
1931 static void
1932 ptnet_tx_task(void *context, int pending)
1933 {
1934         struct ptnet_queue *pq = context;
1935
1936         DBG(nm_prlim(1, "%s: pq #%u\n", __func__, pq->kring_id));
1937         ptnet_drain_transmit_queue(pq, PTNET_TX_BUDGET, true);
1938 }
1939
1940 #ifdef DEVICE_POLLING
1941 /* We don't need to handle differently POLL_AND_CHECK_STATUS and
1942  * POLL_ONLY, since we don't have an Interrupt Status Register. */
1943 static int
1944 ptnet_poll(if_t ifp, enum poll_cmd cmd, int budget)
1945 {
1946         struct ptnet_softc *sc = if_getsoftc(ifp);
1947         unsigned int queue_budget;
1948         unsigned int count = 0;
1949         bool borrow = false;
1950         int i;
1951
1952         KASSERT(sc->num_rings > 0, ("Found no queues in while polling ptnet"));
1953         queue_budget = MAX(budget / sc->num_rings, 1);
1954         nm_prlim(1, "Per-queue budget is %d", queue_budget);
1955
1956         while (budget) {
1957                 unsigned int rcnt = 0;
1958
1959                 for (i = 0; i < sc->num_rings; i++) {
1960                         struct ptnet_queue *pq = sc->queues + i;
1961
1962                         if (borrow) {
1963                                 queue_budget = MIN(queue_budget, budget);
1964                                 if (queue_budget == 0) {
1965                                         break;
1966                                 }
1967                         }
1968
1969                         if (i < sc->num_tx_rings) {
1970                                 rcnt += ptnet_drain_transmit_queue(pq,
1971                                                    queue_budget, false);
1972                         } else {
1973                                 rcnt += ptnet_rx_eof(pq, queue_budget,
1974                                                       false);
1975                         }
1976                 }
1977
1978                 if (!rcnt) {
1979                         /* A scan of the queues gave no result, we can
1980                          * stop here. */
1981                         break;
1982                 }
1983
1984                 if (rcnt > budget) {
1985                         /* This may happen when initial budget < sc->num_rings,
1986                          * since one packet budget is given to each queue
1987                          * anyway. Just pretend we didn't eat "so much". */
1988                         rcnt = budget;
1989                 }
1990                 count += rcnt;
1991                 budget -= rcnt;
1992                 borrow = true;
1993         }
1994
1995
1996         return count;
1997 }
1998 #endif /* DEVICE_POLLING */
1999 #endif /* WITH_PTNETMAP */