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
97static uint64_t	ptnet_get_counter(if_t, ift_counter);
98#else
99typedef 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
111extern int ptnet_vnet_hdr; /* Tunable parameter */
112
113struct ptnet_softc;
114
115struct 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
127struct 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
150struct 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
186static int	ptnet_probe(device_t);
187static int	ptnet_attach(device_t);
188static int	ptnet_detach(device_t);
189static int	ptnet_suspend(device_t);
190static int	ptnet_resume(device_t);
191static int	ptnet_shutdown(device_t);
192
193static void	ptnet_init(void *opaque);
194static int	ptnet_ioctl(if_t ifp, u_long cmd, caddr_t data);
195static int	ptnet_init_locked(struct ptnet_softc *sc);
196static int	ptnet_stop(struct ptnet_softc *sc);
197static int	ptnet_transmit(if_t ifp, struct mbuf *m);
198static int	ptnet_drain_transmit_queue(struct ptnet_queue *pq,
199					   unsigned int budget,
200					   bool may_resched);
201static void	ptnet_qflush(if_t ifp);
202static void	ptnet_tx_task(void *context, int pending);
203
204static int	ptnet_media_change(if_t ifp);
205static void	ptnet_media_status(if_t ifp, struct ifmediareq *ifmr);
206#ifdef PTNETMAP_STATS
207static void	ptnet_tick(void *opaque);
208#endif
209
210static int	ptnet_irqs_init(struct ptnet_softc *sc);
211static void	ptnet_irqs_fini(struct ptnet_softc *sc);
212
213static uint32_t ptnet_nm_ptctl(struct ptnet_softc *sc, uint32_t cmd);
214static int      ptnet_nm_config(struct netmap_adapter *na,
215				struct nm_config_info *info);
216static void	ptnet_update_vnet_hdr(struct ptnet_softc *sc);
217static int	ptnet_nm_register(struct netmap_adapter *na, int onoff);
218static int	ptnet_nm_txsync(struct netmap_kring *kring, int flags);
219static int	ptnet_nm_rxsync(struct netmap_kring *kring, int flags);
220static void	ptnet_nm_intr(struct netmap_adapter *na, int onoff);
221
222static void	ptnet_tx_intr(void *opaque);
223static void	ptnet_rx_intr(void *opaque);
224
225static unsigned	ptnet_rx_discard(struct netmap_kring *kring,
226				 unsigned int head);
227static int	ptnet_rx_eof(struct ptnet_queue *pq, unsigned int budget,
228			     bool may_resched);
229static void	ptnet_rx_task(void *context, int pending);
230
231#ifdef DEVICE_POLLING
232static poll_handler_t ptnet_poll;
233#endif
234
235static 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
245static 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. */
252static devclass_t ptnet_devclass;
253DRIVER_MODULE_ORDERED(ptnet, pci, ptnet_driver, ptnet_devclass,
254		      NULL, NULL, SI_ORDER_MIDDLE + 2);
255
256static int
257ptnet_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
269static 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
290static int
291ptnet_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
503err_path:
504	ptnet_detach(dev);
505	return err;
506}
507
508/* Stop host sync-kloop if it was running. */
509static void
510ptnet_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
519static int
520ptnet_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
592static int
593ptnet_suspend(device_t dev)
594{
595	struct ptnet_softc *sc = device_get_softc(dev);
596
597	(void)sc;
598
599	return (0);
600}
601
602static int
603ptnet_resume(device_t dev)
604{
605	struct ptnet_softc *sc = device_get_softc(dev);
606
607	(void)sc;
608
609	return (0);
610}
611
612static int
613ptnet_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
622static int
623ptnet_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		static void (*handler)(void *context, int pending);
699
700		handler = (i < sc->num_tx_rings) ? ptnet_tx_task : ptnet_rx_task;
701
702		TASK_INIT(&pq->task, 0, handler, pq);
703		pq->taskq = taskqueue_create_fast("ptnet_queue", M_NOWAIT,
704					taskqueue_thread_enqueue, &pq->taskq);
705		taskqueue_start_threads(&pq->taskq, 1, PI_NET, "%s-pq-%d",
706					device_get_nameunit(sc->dev), cpu_cur);
707		cpu_cur = CPU_NEXT(cpu_cur);
708	}
709
710	return 0;
711err_path:
712	ptnet_irqs_fini(sc);
713	return err;
714}
715
716static void
717ptnet_irqs_fini(struct ptnet_softc *sc)
718{
719	device_t dev = sc->dev;
720	int i;
721
722	for (i = 0; i < sc->num_rings; i++) {
723		struct ptnet_queue *pq = sc->queues + i;
724
725		if (pq->taskq) {
726			taskqueue_free(pq->taskq);
727			pq->taskq = NULL;
728		}
729
730		if (pq->cookie) {
731			bus_teardown_intr(dev, pq->irq, pq->cookie);
732			pq->cookie = NULL;
733		}
734
735		if (pq->irq) {
736			bus_release_resource(dev, SYS_RES_IRQ, i + 1, pq->irq);
737			pq->irq = NULL;
738		}
739	}
740
741	if (sc->msix_mem) {
742		pci_release_msi(dev);
743
744		bus_release_resource(dev, SYS_RES_MEMORY,
745				     PCIR_BAR(PTNETMAP_MSIX_PCI_BAR),
746				     sc->msix_mem);
747		sc->msix_mem = NULL;
748	}
749}
750
751static void
752ptnet_init(void *opaque)
753{
754	struct ptnet_softc *sc = opaque;
755
756	PTNET_CORE_LOCK(sc);
757	ptnet_init_locked(sc);
758	PTNET_CORE_UNLOCK(sc);
759}
760
761static int
762ptnet_ioctl(if_t ifp, u_long cmd, caddr_t data)
763{
764	struct ptnet_softc *sc = if_getsoftc(ifp);
765	device_t dev = sc->dev;
766	struct ifreq *ifr = (struct ifreq *)data;
767	int mask __unused, err = 0;
768
769	switch (cmd) {
770	case SIOCSIFFLAGS:
771		device_printf(dev, "SIOCSIFFLAGS %x\n", ifp->if_flags);
772		PTNET_CORE_LOCK(sc);
773		if (ifp->if_flags & IFF_UP) {
774			/* Network stack wants the iff to be up. */
775			err = ptnet_init_locked(sc);
776		} else {
777			/* Network stack wants the iff to be down. */
778			err = ptnet_stop(sc);
779		}
780		/* We don't need to do nothing to support IFF_PROMISC,
781		 * since that is managed by the backend port. */
782		PTNET_CORE_UNLOCK(sc);
783		break;
784
785	case SIOCSIFCAP:
786		device_printf(dev, "SIOCSIFCAP %x %x\n",
787			      ifr->ifr_reqcap, ifp->if_capenable);
788		mask = ifr->ifr_reqcap ^ ifp->if_capenable;
789#ifdef DEVICE_POLLING
790		if (mask & IFCAP_POLLING) {
791			struct ptnet_queue *pq;
792			int i;
793
794			if (ifr->ifr_reqcap & IFCAP_POLLING) {
795				err = ether_poll_register(ptnet_poll, ifp);
796				if (err) {
797					break;
798				}
799				/* Stop queues and sync with taskqueues. */
800				ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
801				for (i = 0; i < sc->num_rings; i++) {
802					pq = sc-> queues + i;
803					/* Make sure the worker sees the
804					 * IFF_DRV_RUNNING down. */
805					PTNET_Q_LOCK(pq);
806					pq->atok->appl_need_kick = 0;
807					PTNET_Q_UNLOCK(pq);
808					/* Wait for rescheduling to finish. */
809					if (pq->taskq) {
810						taskqueue_drain(pq->taskq,
811								&pq->task);
812					}
813				}
814				ifp->if_drv_flags |= IFF_DRV_RUNNING;
815			} else {
816				err = ether_poll_deregister(ifp);
817				for (i = 0; i < sc->num_rings; i++) {
818					pq = sc-> queues + i;
819					PTNET_Q_LOCK(pq);
820					pq->atok->appl_need_kick = 1;
821					PTNET_Q_UNLOCK(pq);
822				}
823			}
824		}
825#endif  /* DEVICE_POLLING */
826		ifp->if_capenable = ifr->ifr_reqcap;
827		break;
828
829	case SIOCSIFMTU:
830		/* We support any reasonable MTU. */
831		if (ifr->ifr_mtu < ETHERMIN ||
832				ifr->ifr_mtu > PTNET_MAX_PKT_SIZE) {
833			err = EINVAL;
834		} else {
835			PTNET_CORE_LOCK(sc);
836			ifp->if_mtu = ifr->ifr_mtu;
837			PTNET_CORE_UNLOCK(sc);
838		}
839		break;
840
841	case SIOCSIFMEDIA:
842	case SIOCGIFMEDIA:
843		err = ifmedia_ioctl(ifp, ifr, &sc->media, cmd);
844		break;
845
846	default:
847		err = ether_ioctl(ifp, cmd, data);
848		break;
849	}
850
851	return err;
852}
853
854static int
855ptnet_init_locked(struct ptnet_softc *sc)
856{
857	if_t ifp = sc->ifp;
858	struct netmap_adapter *na_dr = &sc->ptna->dr.up;
859	struct netmap_adapter *na_nm = &sc->ptna->hwup.up;
860	unsigned int nm_buf_size;
861	int ret;
862
863	if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
864		return 0; /* nothing to do */
865	}
866
867	device_printf(sc->dev, "%s\n", __func__);
868
869	/* Translate offload capabilities according to if_capenable. */
870	ifp->if_hwassist = 0;
871	if (ifp->if_capenable & IFCAP_TXCSUM)
872		ifp->if_hwassist |= PTNET_CSUM_OFFLOAD;
873	if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
874		ifp->if_hwassist |= PTNET_CSUM_OFFLOAD_IPV6;
875	if (ifp->if_capenable & IFCAP_TSO4)
876		ifp->if_hwassist |= CSUM_IP_TSO;
877	if (ifp->if_capenable & IFCAP_TSO6)
878		ifp->if_hwassist |= CSUM_IP6_TSO;
879
880	/*
881	 * Prepare the interface for netmap mode access.
882	 */
883	netmap_update_config(na_dr);
884
885	ret = netmap_mem_finalize(na_dr->nm_mem, na_dr);
886	if (ret) {
887		device_printf(sc->dev, "netmap_mem_finalize() failed\n");
888		return ret;
889	}
890
891	if (sc->ptna->backend_users == 0) {
892		ret = ptnet_nm_krings_create(na_nm);
893		if (ret) {
894			device_printf(sc->dev, "ptnet_nm_krings_create() "
895					       "failed\n");
896			goto err_mem_finalize;
897		}
898
899		ret = netmap_mem_rings_create(na_dr);
900		if (ret) {
901			device_printf(sc->dev, "netmap_mem_rings_create() "
902					       "failed\n");
903			goto err_rings_create;
904		}
905
906		ret = netmap_mem_get_lut(na_dr->nm_mem, &na_dr->na_lut);
907		if (ret) {
908			device_printf(sc->dev, "netmap_mem_get_lut() "
909					       "failed\n");
910			goto err_get_lut;
911		}
912	}
913
914	ret = ptnet_nm_register(na_dr, 1 /* on */);
915	if (ret) {
916		goto err_register;
917	}
918
919	nm_buf_size = NETMAP_BUF_SIZE(na_dr);
920
921	KASSERT(nm_buf_size > 0, ("Invalid netmap buffer size"));
922	sc->min_tx_space = PTNET_MAX_PKT_SIZE / nm_buf_size + 2;
923	device_printf(sc->dev, "%s: min_tx_space = %u\n", __func__,
924		      sc->min_tx_space);
925#ifdef PTNETMAP_STATS
926	callout_reset(&sc->tick, hz, ptnet_tick, sc);
927#endif
928
929	ifp->if_drv_flags |= IFF_DRV_RUNNING;
930
931	return 0;
932
933err_register:
934	memset(&na_dr->na_lut, 0, sizeof(na_dr->na_lut));
935err_get_lut:
936	netmap_mem_rings_delete(na_dr);
937err_rings_create:
938	ptnet_nm_krings_delete(na_nm);
939err_mem_finalize:
940	netmap_mem_deref(na_dr->nm_mem, na_dr);
941
942	return ret;
943}
944
945/* To be called under core lock. */
946static int
947ptnet_stop(struct ptnet_softc *sc)
948{
949	if_t ifp = sc->ifp;
950	struct netmap_adapter *na_dr = &sc->ptna->dr.up;
951	struct netmap_adapter *na_nm = &sc->ptna->hwup.up;
952	int i;
953
954	device_printf(sc->dev, "%s\n", __func__);
955
956	if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
957		return 0; /* nothing to do */
958	}
959
960	/* Clear the driver-ready flag, and synchronize with all the queues,
961	 * so that after this loop we are sure nobody is working anymore with
962	 * the device. This scheme is taken from the vtnet driver. */
963	ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
964	callout_stop(&sc->tick);
965	for (i = 0; i < sc->num_rings; i++) {
966		PTNET_Q_LOCK(sc->queues + i);
967		PTNET_Q_UNLOCK(sc->queues + i);
968	}
969
970	ptnet_nm_register(na_dr, 0 /* off */);
971
972	if (sc->ptna->backend_users == 0) {
973		netmap_mem_rings_delete(na_dr);
974		ptnet_nm_krings_delete(na_nm);
975	}
976	netmap_mem_deref(na_dr->nm_mem, na_dr);
977
978	return 0;
979}
980
981static void
982ptnet_qflush(if_t ifp)
983{
984	struct ptnet_softc *sc = if_getsoftc(ifp);
985	int i;
986
987	/* Flush all the bufrings and do the interface flush. */
988	for (i = 0; i < sc->num_rings; i++) {
989		struct ptnet_queue *pq = sc->queues + i;
990		struct mbuf *m;
991
992		PTNET_Q_LOCK(pq);
993		if (pq->bufring) {
994			while ((m = buf_ring_dequeue_sc(pq->bufring))) {
995				m_freem(m);
996			}
997		}
998		PTNET_Q_UNLOCK(pq);
999	}
1000
1001	if_qflush(ifp);
1002}
1003
1004static int
1005ptnet_media_change(if_t ifp)
1006{
1007	struct ptnet_softc *sc = if_getsoftc(ifp);
1008	struct ifmedia *ifm = &sc->media;
1009
1010	if (IFM_TYPE(ifm->ifm_media) != IFM_ETHER) {
1011		return EINVAL;
1012	}
1013
1014	return 0;
1015}
1016
1017#if __FreeBSD_version >= 1100000
1018static uint64_t
1019ptnet_get_counter(if_t ifp, ift_counter cnt)
1020{
1021	struct ptnet_softc *sc = if_getsoftc(ifp);
1022	struct ptnet_queue_stats stats[2];
1023	int i;
1024
1025	/* Accumulate statistics over the queues. */
1026	memset(stats, 0, sizeof(stats));
1027	for (i = 0; i < sc->num_rings; i++) {
1028		struct ptnet_queue *pq = sc->queues + i;
1029		int idx = (i < sc->num_tx_rings) ? 0 : 1;
1030
1031		stats[idx].packets	+= pq->stats.packets;
1032		stats[idx].bytes	+= pq->stats.bytes;
1033		stats[idx].errors	+= pq->stats.errors;
1034		stats[idx].iqdrops	+= pq->stats.iqdrops;
1035		stats[idx].mcasts	+= pq->stats.mcasts;
1036	}
1037
1038	switch (cnt) {
1039	case IFCOUNTER_IPACKETS:
1040		return (stats[1].packets);
1041	case IFCOUNTER_IQDROPS:
1042		return (stats[1].iqdrops);
1043	case IFCOUNTER_IERRORS:
1044		return (stats[1].errors);
1045	case IFCOUNTER_OPACKETS:
1046		return (stats[0].packets);
1047	case IFCOUNTER_OBYTES:
1048		return (stats[0].bytes);
1049	case IFCOUNTER_OMCASTS:
1050		return (stats[0].mcasts);
1051	default:
1052		return (if_get_counter_default(ifp, cnt));
1053	}
1054}
1055#endif
1056
1057
1058#ifdef PTNETMAP_STATS
1059/* Called under core lock. */
1060static void
1061ptnet_tick(void *opaque)
1062{
1063	struct ptnet_softc *sc = opaque;
1064	int i;
1065
1066	for (i = 0; i < sc->num_rings; i++) {
1067		struct ptnet_queue *pq = sc->queues + i;
1068		struct ptnet_queue_stats cur = pq->stats;
1069		struct timeval now;
1070		unsigned int delta;
1071
1072		microtime(&now);
1073		delta = now.tv_usec - sc->last_ts.tv_usec +
1074			(now.tv_sec - sc->last_ts.tv_sec) * 1000000;
1075		delta /= 1000; /* in milliseconds */
1076
1077		if (delta == 0)
1078			continue;
1079
1080		device_printf(sc->dev, "#%d[%u ms]:pkts %lu, kicks %lu, "
1081			      "intr %lu\n", i, delta,
1082			      (cur.packets - pq->last_stats.packets),
1083			      (cur.kicks - pq->last_stats.kicks),
1084			      (cur.intrs - pq->last_stats.intrs));
1085		pq->last_stats = cur;
1086	}
1087	microtime(&sc->last_ts);
1088	callout_schedule(&sc->tick, hz);
1089}
1090#endif /* PTNETMAP_STATS */
1091
1092static void
1093ptnet_media_status(if_t ifp, struct ifmediareq *ifmr)
1094{
1095	/* We are always active, as the backend netmap port is
1096	 * always open in netmap mode. */
1097	ifmr->ifm_status = IFM_AVALID | IFM_ACTIVE;
1098	ifmr->ifm_active = IFM_ETHER | IFM_10G_T | IFM_FDX;
1099}
1100
1101static uint32_t
1102ptnet_nm_ptctl(struct ptnet_softc *sc, uint32_t cmd)
1103{
1104	/*
1105	 * Write a command and read back error status,
1106	 * with zero meaning success.
1107	 */
1108	bus_write_4(sc->iomem, PTNET_IO_PTCTL, cmd);
1109	return bus_read_4(sc->iomem, PTNET_IO_PTCTL);
1110}
1111
1112static int
1113ptnet_nm_config(struct netmap_adapter *na, struct nm_config_info *info)
1114{
1115	struct ptnet_softc *sc = if_getsoftc(na->ifp);
1116
1117	info->num_tx_rings = bus_read_4(sc->iomem, PTNET_IO_NUM_TX_RINGS);
1118	info->num_rx_rings = bus_read_4(sc->iomem, PTNET_IO_NUM_RX_RINGS);
1119	info->num_tx_descs = bus_read_4(sc->iomem, PTNET_IO_NUM_TX_SLOTS);
1120	info->num_rx_descs = bus_read_4(sc->iomem, PTNET_IO_NUM_RX_SLOTS);
1121	info->rx_buf_maxsize = NETMAP_BUF_SIZE(na);
1122
1123	device_printf(sc->dev, "txr %u, rxr %u, txd %u, rxd %u, rxbufsz %u\n",
1124			info->num_tx_rings, info->num_rx_rings,
1125			info->num_tx_descs, info->num_rx_descs,
1126			info->rx_buf_maxsize);
1127
1128	return 0;
1129}
1130
1131static void
1132ptnet_sync_from_csb(struct ptnet_softc *sc, struct netmap_adapter *na)
1133{
1134	int i;
1135
1136	/* Sync krings from the host, reading from
1137	 * CSB. */
1138	for (i = 0; i < sc->num_rings; i++) {
1139		struct nm_csb_atok *atok = sc->queues[i].atok;
1140		struct nm_csb_ktoa *ktoa = sc->queues[i].ktoa;
1141		struct netmap_kring *kring;
1142
1143		if (i < na->num_tx_rings) {
1144			kring = na->tx_rings[i];
1145		} else {
1146			kring = na->rx_rings[i - na->num_tx_rings];
1147		}
1148		kring->rhead = kring->ring->head = atok->head;
1149		kring->rcur = kring->ring->cur = atok->cur;
1150		kring->nr_hwcur = ktoa->hwcur;
1151		kring->nr_hwtail = kring->rtail =
1152			kring->ring->tail = ktoa->hwtail;
1153
1154		nm_prdis("%d,%d: csb {hc %u h %u c %u ht %u}", t, i,
1155		   ktoa->hwcur, atok->head, atok->cur,
1156		   ktoa->hwtail);
1157		nm_prdis("%d,%d: kring {hc %u rh %u rc %u h %u c %u ht %u rt %u t %u}",
1158		   t, i, kring->nr_hwcur, kring->rhead, kring->rcur,
1159		   kring->ring->head, kring->ring->cur, kring->nr_hwtail,
1160		   kring->rtail, kring->ring->tail);
1161	}
1162}
1163
1164static void
1165ptnet_update_vnet_hdr(struct ptnet_softc *sc)
1166{
1167	unsigned int wanted_hdr_len = ptnet_vnet_hdr ? PTNET_HDR_SIZE : 0;
1168
1169	bus_write_4(sc->iomem, PTNET_IO_VNET_HDR_LEN, wanted_hdr_len);
1170	sc->vnet_hdr_len = bus_read_4(sc->iomem, PTNET_IO_VNET_HDR_LEN);
1171	sc->ptna->hwup.up.virt_hdr_len = sc->vnet_hdr_len;
1172}
1173
1174static int
1175ptnet_nm_register(struct netmap_adapter *na, int onoff)
1176{
1177	/* device-specific */
1178	if_t ifp = na->ifp;
1179	struct ptnet_softc *sc = if_getsoftc(ifp);
1180	int native = (na == &sc->ptna->hwup.up);
1181	struct ptnet_queue *pq;
1182	int ret = 0;
1183	int i;
1184
1185	if (!onoff) {
1186		sc->ptna->backend_users--;
1187	}
1188
1189	/* If this is the last netmap client, guest interrupt enable flags may
1190	 * be in arbitrary state. Since these flags are going to be used also
1191	 * by the netdevice driver, we have to make sure to start with
1192	 * notifications enabled. Also, schedule NAPI to flush pending packets
1193	 * in the RX rings, since we will not receive further interrupts
1194	 * until these will be processed. */
1195	if (native && !onoff && na->active_fds == 0) {
1196		nm_prinf("Exit netmap mode, re-enable interrupts");
1197		for (i = 0; i < sc->num_rings; i++) {
1198			pq = sc->queues + i;
1199			pq->atok->appl_need_kick = 1;
1200		}
1201	}
1202
1203	if (onoff) {
1204		if (sc->ptna->backend_users == 0) {
1205			/* Initialize notification enable fields in the CSB. */
1206			for (i = 0; i < sc->num_rings; i++) {
1207				pq = sc->queues + i;
1208				pq->ktoa->kern_need_kick = 1;
1209				pq->atok->appl_need_kick =
1210					(!(ifp->if_capenable & IFCAP_POLLING)
1211						&& i >= sc->num_tx_rings);
1212			}
1213
1214			/* Set the virtio-net header length. */
1215			ptnet_update_vnet_hdr(sc);
1216
1217			/* Make sure the host adapter passed through is ready
1218			 * for txsync/rxsync. */
1219			ret = ptnet_nm_ptctl(sc, PTNETMAP_PTCTL_CREATE);
1220			if (ret) {
1221				return ret;
1222			}
1223
1224			/* Align the guest krings and rings to the state stored
1225			 * in the CSB. */
1226			ptnet_sync_from_csb(sc, na);
1227		}
1228
1229		/* If not native, don't call nm_set_native_flags, since we don't want
1230		 * to replace if_transmit method, nor set NAF_NETMAP_ON */
1231		if (native) {
1232			netmap_krings_mode_commit(na, onoff);
1233			nm_set_native_flags(na);
1234		}
1235
1236	} else {
1237		if (native) {
1238			nm_clear_native_flags(na);
1239			netmap_krings_mode_commit(na, onoff);
1240		}
1241
1242		if (sc->ptna->backend_users == 0) {
1243			ret = ptnet_nm_ptctl(sc, PTNETMAP_PTCTL_DELETE);
1244		}
1245	}
1246
1247	if (onoff) {
1248		sc->ptna->backend_users++;
1249	}
1250
1251	return ret;
1252}
1253
1254static int
1255ptnet_nm_txsync(struct netmap_kring *kring, int flags)
1256{
1257	struct ptnet_softc *sc = if_getsoftc(kring->na->ifp);
1258	struct ptnet_queue *pq = sc->queues + kring->ring_id;
1259	bool notify;
1260
1261	notify = netmap_pt_guest_txsync(pq->atok, pq->ktoa, kring, flags);
1262	if (notify) {
1263		ptnet_kick(pq);
1264	}
1265
1266	return 0;
1267}
1268
1269static int
1270ptnet_nm_rxsync(struct netmap_kring *kring, int flags)
1271{
1272	struct ptnet_softc *sc = if_getsoftc(kring->na->ifp);
1273	struct ptnet_queue *pq = sc->rxqueues + kring->ring_id;
1274	bool notify;
1275
1276	notify = netmap_pt_guest_rxsync(pq->atok, pq->ktoa, kring, flags);
1277	if (notify) {
1278		ptnet_kick(pq);
1279	}
1280
1281	return 0;
1282}
1283
1284static void
1285ptnet_nm_intr(struct netmap_adapter *na, int onoff)
1286{
1287	struct ptnet_softc *sc = if_getsoftc(na->ifp);
1288	int i;
1289
1290	for (i = 0; i < sc->num_rings; i++) {
1291		struct ptnet_queue *pq = sc->queues + i;
1292		pq->atok->appl_need_kick = onoff;
1293	}
1294}
1295
1296static void
1297ptnet_tx_intr(void *opaque)
1298{
1299	struct ptnet_queue *pq = opaque;
1300	struct ptnet_softc *sc = pq->sc;
1301
1302	DBG(device_printf(sc->dev, "Tx interrupt #%d\n", pq->kring_id));
1303#ifdef PTNETMAP_STATS
1304	pq->stats.intrs ++;
1305#endif /* PTNETMAP_STATS */
1306
1307	if (netmap_tx_irq(sc->ifp, pq->kring_id) != NM_IRQ_PASS) {
1308		return;
1309	}
1310
1311	/* Schedule the tasqueue to flush process transmissions requests.
1312	 * However, vtnet, if_em and if_igb just call ptnet_transmit() here,
1313	 * at least when using MSI-X interrupts. The if_em driver, instead
1314	 * schedule taskqueue when using legacy interrupts. */
1315	taskqueue_enqueue(pq->taskq, &pq->task);
1316}
1317
1318static void
1319ptnet_rx_intr(void *opaque)
1320{
1321	struct ptnet_queue *pq = opaque;
1322	struct ptnet_softc *sc = pq->sc;
1323	unsigned int unused;
1324
1325	DBG(device_printf(sc->dev, "Rx interrupt #%d\n", pq->kring_id));
1326#ifdef PTNETMAP_STATS
1327	pq->stats.intrs ++;
1328#endif /* PTNETMAP_STATS */
1329
1330	if (netmap_rx_irq(sc->ifp, pq->kring_id, &unused) != NM_IRQ_PASS) {
1331		return;
1332	}
1333
1334	/* Like vtnet, if_igb and if_em drivers when using MSI-X interrupts,
1335	 * receive-side processing is executed directly in the interrupt
1336	 * service routine. Alternatively, we may schedule the taskqueue. */
1337	ptnet_rx_eof(pq, PTNET_RX_BUDGET, true);
1338}
1339
1340/* The following offloadings-related functions are taken from the vtnet
1341 * driver, but the same functionality is required for the ptnet driver.
1342 * As a temporary solution, I copied this code from vtnet and I started
1343 * to generalize it (taking away driver-specific statistic accounting),
1344 * making as little modifications as possible.
1345 * In the future we need to share these functions between vtnet and ptnet.
1346 */
1347static int
1348ptnet_tx_offload_ctx(struct mbuf *m, int *etype, int *proto, int *start)
1349{
1350	struct ether_vlan_header *evh;
1351	int offset;
1352
1353	evh = mtod(m, struct ether_vlan_header *);
1354	if (evh->evl_encap_proto == htons(ETHERTYPE_VLAN)) {
1355		/* BMV: We should handle nested VLAN tags too. */
1356		*etype = ntohs(evh->evl_proto);
1357		offset = sizeof(struct ether_vlan_header);
1358	} else {
1359		*etype = ntohs(evh->evl_encap_proto);
1360		offset = sizeof(struct ether_header);
1361	}
1362
1363	switch (*etype) {
1364#if defined(INET)
1365	case ETHERTYPE_IP: {
1366		struct ip *ip, iphdr;
1367		if (__predict_false(m->m_len < offset + sizeof(struct ip))) {
1368			m_copydata(m, offset, sizeof(struct ip),
1369			    (caddr_t) &iphdr);
1370			ip = &iphdr;
1371		} else
1372			ip = (struct ip *)(m->m_data + offset);
1373		*proto = ip->ip_p;
1374		*start = offset + (ip->ip_hl << 2);
1375		break;
1376	}
1377#endif
1378#if defined(INET6)
1379	case ETHERTYPE_IPV6:
1380		*proto = -1;
1381		*start = ip6_lasthdr(m, offset, IPPROTO_IPV6, proto);
1382		/* Assert the network stack sent us a valid packet. */
1383		KASSERT(*start > offset,
1384		    ("%s: mbuf %p start %d offset %d proto %d", __func__, m,
1385		    *start, offset, *proto));
1386		break;
1387#endif
1388	default:
1389		/* Here we should increment the tx_csum_bad_ethtype counter. */
1390		return (EINVAL);
1391	}
1392
1393	return (0);
1394}
1395
1396static int
1397ptnet_tx_offload_tso(if_t ifp, struct mbuf *m, int eth_type,
1398		     int offset, bool allow_ecn, struct virtio_net_hdr *hdr)
1399{
1400	static struct timeval lastecn;
1401	static int curecn;
1402	struct tcphdr *tcp, tcphdr;
1403
1404	if (__predict_false(m->m_len < offset + sizeof(struct tcphdr))) {
1405		m_copydata(m, offset, sizeof(struct tcphdr), (caddr_t) &tcphdr);
1406		tcp = &tcphdr;
1407	} else
1408		tcp = (struct tcphdr *)(m->m_data + offset);
1409
1410	hdr->hdr_len = offset + (tcp->th_off << 2);
1411	hdr->gso_size = m->m_pkthdr.tso_segsz;
1412	hdr->gso_type = eth_type == ETHERTYPE_IP ? VIRTIO_NET_HDR_GSO_TCPV4 :
1413	    VIRTIO_NET_HDR_GSO_TCPV6;
1414
1415	if (tcp->th_flags & TH_CWR) {
1416		/*
1417		 * Drop if VIRTIO_NET_F_HOST_ECN was not negotiated. In FreeBSD,
1418		 * ECN support is not on a per-interface basis, but globally via
1419		 * the net.inet.tcp.ecn.enable sysctl knob. The default is off.
1420		 */
1421		if (!allow_ecn) {
1422			if (ppsratecheck(&lastecn, &curecn, 1))
1423				if_printf(ifp,
1424				    "TSO with ECN not negotiated with host\n");
1425			return (ENOTSUP);
1426		}
1427		hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1428	}
1429
1430	/* Here we should increment tx_tso counter. */
1431
1432	return (0);
1433}
1434
1435static struct mbuf *
1436ptnet_tx_offload(if_t ifp, struct mbuf *m, bool allow_ecn,
1437		 struct virtio_net_hdr *hdr)
1438{
1439	int flags, etype, csum_start, proto, error;
1440
1441	flags = m->m_pkthdr.csum_flags;
1442
1443	error = ptnet_tx_offload_ctx(m, &etype, &proto, &csum_start);
1444	if (error)
1445		goto drop;
1446
1447	if ((etype == ETHERTYPE_IP && flags & PTNET_CSUM_OFFLOAD) ||
1448	    (etype == ETHERTYPE_IPV6 && flags & PTNET_CSUM_OFFLOAD_IPV6)) {
1449		/*
1450		 * We could compare the IP protocol vs the CSUM_ flag too,
1451		 * but that really should not be necessary.
1452		 */
1453		hdr->flags |= VIRTIO_NET_HDR_F_NEEDS_CSUM;
1454		hdr->csum_start = csum_start;
1455		hdr->csum_offset = m->m_pkthdr.csum_data;
1456		/* Here we should increment the tx_csum counter. */
1457	}
1458
1459	if (flags & CSUM_TSO) {
1460		if (__predict_false(proto != IPPROTO_TCP)) {
1461			/* Likely failed to correctly parse the mbuf.
1462			 * Here we should increment the tx_tso_not_tcp
1463			 * counter. */
1464			goto drop;
1465		}
1466
1467		KASSERT(hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM,
1468		    ("%s: mbuf %p TSO without checksum offload %#x",
1469		    __func__, m, flags));
1470
1471		error = ptnet_tx_offload_tso(ifp, m, etype, csum_start,
1472					     allow_ecn, hdr);
1473		if (error)
1474			goto drop;
1475	}
1476
1477	return (m);
1478
1479drop:
1480	m_freem(m);
1481	return (NULL);
1482}
1483
1484static void
1485ptnet_vlan_tag_remove(struct mbuf *m)
1486{
1487	struct ether_vlan_header *evh;
1488
1489	evh = mtod(m, struct ether_vlan_header *);
1490	m->m_pkthdr.ether_vtag = ntohs(evh->evl_tag);
1491	m->m_flags |= M_VLANTAG;
1492
1493	/* Strip the 802.1Q header. */
1494	bcopy((char *) evh, (char *) evh + ETHER_VLAN_ENCAP_LEN,
1495	    ETHER_HDR_LEN - ETHER_TYPE_LEN);
1496	m_adj(m, ETHER_VLAN_ENCAP_LEN);
1497}
1498
1499/*
1500 * Use the checksum offset in the VirtIO header to set the
1501 * correct CSUM_* flags.
1502 */
1503static int
1504ptnet_rx_csum_by_offset(struct mbuf *m, uint16_t eth_type, int ip_start,
1505			struct virtio_net_hdr *hdr)
1506{
1507#if defined(INET) || defined(INET6)
1508	int offset = hdr->csum_start + hdr->csum_offset;
1509#endif
1510
1511	/* Only do a basic sanity check on the offset. */
1512	switch (eth_type) {
1513#if defined(INET)
1514	case ETHERTYPE_IP:
1515		if (__predict_false(offset < ip_start + sizeof(struct ip)))
1516			return (1);
1517		break;
1518#endif
1519#if defined(INET6)
1520	case ETHERTYPE_IPV6:
1521		if (__predict_false(offset < ip_start + sizeof(struct ip6_hdr)))
1522			return (1);
1523		break;
1524#endif
1525	default:
1526		/* Here we should increment the rx_csum_bad_ethtype counter. */
1527		return (1);
1528	}
1529
1530	/*
1531	 * Use the offset to determine the appropriate CSUM_* flags. This is
1532	 * a bit dirty, but we can get by with it since the checksum offsets
1533	 * happen to be different. We assume the host host does not do IPv4
1534	 * header checksum offloading.
1535	 */
1536	switch (hdr->csum_offset) {
1537	case offsetof(struct udphdr, uh_sum):
1538	case offsetof(struct tcphdr, th_sum):
1539		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1540		m->m_pkthdr.csum_data = 0xFFFF;
1541		break;
1542	default:
1543		/* Here we should increment the rx_csum_bad_offset counter. */
1544		return (1);
1545	}
1546
1547	return (0);
1548}
1549
1550static int
1551ptnet_rx_csum_by_parse(struct mbuf *m, uint16_t eth_type, int ip_start,
1552		       struct virtio_net_hdr *hdr)
1553{
1554	int offset, proto;
1555
1556	switch (eth_type) {
1557#if defined(INET)
1558	case ETHERTYPE_IP: {
1559		struct ip *ip;
1560		if (__predict_false(m->m_len < ip_start + sizeof(struct ip)))
1561			return (1);
1562		ip = (struct ip *)(m->m_data + ip_start);
1563		proto = ip->ip_p;
1564		offset = ip_start + (ip->ip_hl << 2);
1565		break;
1566	}
1567#endif
1568#if defined(INET6)
1569	case ETHERTYPE_IPV6:
1570		if (__predict_false(m->m_len < ip_start +
1571		    sizeof(struct ip6_hdr)))
1572			return (1);
1573		offset = ip6_lasthdr(m, ip_start, IPPROTO_IPV6, &proto);
1574		if (__predict_false(offset < 0))
1575			return (1);
1576		break;
1577#endif
1578	default:
1579		/* Here we should increment the rx_csum_bad_ethtype counter. */
1580		return (1);
1581	}
1582
1583	switch (proto) {
1584	case IPPROTO_TCP:
1585		if (__predict_false(m->m_len < offset + sizeof(struct tcphdr)))
1586			return (1);
1587		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1588		m->m_pkthdr.csum_data = 0xFFFF;
1589		break;
1590	case IPPROTO_UDP:
1591		if (__predict_false(m->m_len < offset + sizeof(struct udphdr)))
1592			return (1);
1593		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1594		m->m_pkthdr.csum_data = 0xFFFF;
1595		break;
1596	default:
1597		/*
1598		 * For the remaining protocols, FreeBSD does not support
1599		 * checksum offloading, so the checksum will be recomputed.
1600		 */
1601#if 0
1602		if_printf(ifp, "cksum offload of unsupported "
1603		    "protocol eth_type=%#x proto=%d csum_start=%d "
1604		    "csum_offset=%d\n", __func__, eth_type, proto,
1605		    hdr->csum_start, hdr->csum_offset);
1606#endif
1607		break;
1608	}
1609
1610	return (0);
1611}
1612
1613/*
1614 * Set the appropriate CSUM_* flags. Unfortunately, the information
1615 * provided is not directly useful to us. The VirtIO header gives the
1616 * offset of the checksum, which is all Linux needs, but this is not
1617 * how FreeBSD does things. We are forced to peek inside the packet
1618 * a bit.
1619 *
1620 * It would be nice if VirtIO gave us the L4 protocol or if FreeBSD
1621 * could accept the offsets and let the stack figure it out.
1622 */
1623static int
1624ptnet_rx_csum(struct mbuf *m, struct virtio_net_hdr *hdr)
1625{
1626	struct ether_header *eh;
1627	struct ether_vlan_header *evh;
1628	uint16_t eth_type;
1629	int offset, error;
1630
1631	eh = mtod(m, struct ether_header *);
1632	eth_type = ntohs(eh->ether_type);
1633	if (eth_type == ETHERTYPE_VLAN) {
1634		/* BMV: We should handle nested VLAN tags too. */
1635		evh = mtod(m, struct ether_vlan_header *);
1636		eth_type = ntohs(evh->evl_proto);
1637		offset = sizeof(struct ether_vlan_header);
1638	} else
1639		offset = sizeof(struct ether_header);
1640
1641	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
1642		error = ptnet_rx_csum_by_offset(m, eth_type, offset, hdr);
1643	else
1644		error = ptnet_rx_csum_by_parse(m, eth_type, offset, hdr);
1645
1646	return (error);
1647}
1648/* End of offloading-related functions to be shared with vtnet. */
1649
1650static void
1651ptnet_ring_update(struct ptnet_queue *pq, struct netmap_kring *kring,
1652		  unsigned int head, unsigned int sync_flags)
1653{
1654	struct netmap_ring *ring = kring->ring;
1655	struct nm_csb_atok *atok = pq->atok;
1656	struct nm_csb_ktoa *ktoa = pq->ktoa;
1657
1658	/* Some packets have been pushed to the netmap ring. We have
1659	 * to tell the host to process the new packets, updating cur
1660	 * and head in the CSB. */
1661	ring->head = ring->cur = head;
1662
1663	/* Mimic nm_txsync_prologue/nm_rxsync_prologue. */
1664	kring->rcur = kring->rhead = head;
1665
1666	nm_sync_kloop_appl_write(atok, kring->rcur, kring->rhead);
1667
1668	/* Kick the host if needed. */
1669	if (NM_ACCESS_ONCE(ktoa->kern_need_kick)) {
1670		atok->sync_flags = sync_flags;
1671		ptnet_kick(pq);
1672	}
1673}
1674
1675#define PTNET_TX_NOSPACE(_h, _k, _min)	\
1676	((((_h) < (_k)->rtail) ? 0 : (_k)->nkr_num_slots) + \
1677		(_k)->rtail - (_h)) < (_min)
1678
1679/* This function may be called by the network stack, or by
1680 * by the taskqueue thread. */
1681static int
1682ptnet_drain_transmit_queue(struct ptnet_queue *pq, unsigned int budget,
1683			   bool may_resched)
1684{
1685	struct ptnet_softc *sc = pq->sc;
1686	bool have_vnet_hdr = sc->vnet_hdr_len;
1687	struct netmap_adapter *na = &sc->ptna->dr.up;
1688	if_t ifp = sc->ifp;
1689	unsigned int batch_count = 0;
1690	struct nm_csb_atok *atok;
1691	struct nm_csb_ktoa *ktoa;
1692	struct netmap_kring *kring;
1693	struct netmap_ring *ring;
1694	struct netmap_slot *slot;
1695	unsigned int count = 0;
1696	unsigned int minspace;
1697	unsigned int head;
1698	unsigned int lim;
1699	struct mbuf *mhead;
1700	struct mbuf *mf;
1701	int nmbuf_bytes;
1702	uint8_t *nmbuf;
1703
1704	if (!PTNET_Q_TRYLOCK(pq)) {
1705		/* We failed to acquire the lock, schedule the taskqueue. */
1706		nm_prlim(1, "Deferring TX work");
1707		if (may_resched) {
1708			taskqueue_enqueue(pq->taskq, &pq->task);
1709		}
1710
1711		return 0;
1712	}
1713
1714	if (unlikely(!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
1715		PTNET_Q_UNLOCK(pq);
1716		nm_prlim(1, "Interface is down");
1717		return ENETDOWN;
1718	}
1719
1720	atok = pq->atok;
1721	ktoa = pq->ktoa;
1722	kring = na->tx_rings[pq->kring_id];
1723	ring = kring->ring;
1724	lim = kring->nkr_num_slots - 1;
1725	head = ring->head;
1726	minspace = sc->min_tx_space;
1727
1728	while (count < budget) {
1729		if (PTNET_TX_NOSPACE(head, kring, minspace)) {
1730			/* We ran out of slot, let's see if the host has
1731			 * freed up some, by reading hwcur and hwtail from
1732			 * the CSB. */
1733			ptnet_sync_tail(ktoa, kring);
1734
1735			if (PTNET_TX_NOSPACE(head, kring, minspace)) {
1736				/* Still no slots available. Reactivate the
1737				 * interrupts so that we can be notified
1738				 * when some free slots are made available by
1739				 * the host. */
1740				atok->appl_need_kick = 1;
1741
1742				/* Double check. We need a full barrier to
1743				 * prevent the store to atok->appl_need_kick
1744				 * to be reordered with the load from
1745				 * ktoa->hwcur and ktoa->hwtail (store-load
1746				 * barrier). */
1747				nm_stld_barrier();
1748				ptnet_sync_tail(ktoa, kring);
1749				if (likely(PTNET_TX_NOSPACE(head, kring,
1750							    minspace))) {
1751					break;
1752				}
1753
1754				nm_prlim(1, "Found more slots by doublecheck");
1755				/* More slots were freed before reactivating
1756				 * the interrupts. */
1757				atok->appl_need_kick = 0;
1758			}
1759		}
1760
1761		mhead = drbr_peek(ifp, pq->bufring);
1762		if (!mhead) {
1763			break;
1764		}
1765
1766		/* Initialize transmission state variables. */
1767		slot = ring->slot + head;
1768		nmbuf = NMB(na, slot);
1769		nmbuf_bytes = 0;
1770
1771		/* If needed, prepare the virtio-net header at the beginning
1772		 * of the first slot. */
1773		if (have_vnet_hdr) {
1774			struct virtio_net_hdr *vh =
1775					(struct virtio_net_hdr *)nmbuf;
1776
1777			/* For performance, we could replace this memset() with
1778			 * two 8-bytes-wide writes. */
1779			memset(nmbuf, 0, PTNET_HDR_SIZE);
1780			if (mhead->m_pkthdr.csum_flags & PTNET_ALL_OFFLOAD) {
1781				mhead = ptnet_tx_offload(ifp, mhead, false,
1782							 vh);
1783				if (unlikely(!mhead)) {
1784					/* Packet dropped because errors
1785					 * occurred while preparing the vnet
1786					 * header. Let's go ahead with the next
1787					 * packet. */
1788					pq->stats.errors ++;
1789					drbr_advance(ifp, pq->bufring);
1790					continue;
1791				}
1792			}
1793			nm_prdis(1, "%s: [csum_flags %lX] vnet hdr: flags %x "
1794			      "csum_start %u csum_ofs %u hdr_len = %u "
1795			      "gso_size %u gso_type %x", __func__,
1796			      mhead->m_pkthdr.csum_flags, vh->flags,
1797			      vh->csum_start, vh->csum_offset, vh->hdr_len,
1798			      vh->gso_size, vh->gso_type);
1799
1800			nmbuf += PTNET_HDR_SIZE;
1801			nmbuf_bytes += PTNET_HDR_SIZE;
1802		}
1803
1804		for (mf = mhead; mf; mf = mf->m_next) {
1805			uint8_t *mdata = mf->m_data;
1806			int mlen = mf->m_len;
1807
1808			for (;;) {
1809				int copy = NETMAP_BUF_SIZE(na) - nmbuf_bytes;
1810
1811				if (mlen < copy) {
1812					copy = mlen;
1813				}
1814				memcpy(nmbuf, mdata, copy);
1815
1816				mdata += copy;
1817				mlen -= copy;
1818				nmbuf += copy;
1819				nmbuf_bytes += copy;
1820
1821				if (!mlen) {
1822					break;
1823				}
1824
1825				slot->len = nmbuf_bytes;
1826				slot->flags = NS_MOREFRAG;
1827
1828				head = nm_next(head, lim);
1829				KASSERT(head != ring->tail,
1830					("Unexpectedly run out of TX space"));
1831				slot = ring->slot + head;
1832				nmbuf = NMB(na, slot);
1833				nmbuf_bytes = 0;
1834			}
1835		}
1836
1837		/* Complete last slot and update head. */
1838		slot->len = nmbuf_bytes;
1839		slot->flags = 0;
1840		head = nm_next(head, lim);
1841
1842		/* Consume the packet just processed. */
1843		drbr_advance(ifp, pq->bufring);
1844
1845		/* Copy the packet to listeners. */
1846		ETHER_BPF_MTAP(ifp, mhead);
1847
1848		pq->stats.packets ++;
1849		pq->stats.bytes += mhead->m_pkthdr.len;
1850		if (mhead->m_flags & M_MCAST) {
1851			pq->stats.mcasts ++;
1852		}
1853
1854		m_freem(mhead);
1855
1856		count ++;
1857		if (++batch_count == PTNET_TX_BATCH) {
1858			ptnet_ring_update(pq, kring, head, NAF_FORCE_RECLAIM);
1859			batch_count = 0;
1860		}
1861	}
1862
1863	if (batch_count) {
1864		ptnet_ring_update(pq, kring, head, NAF_FORCE_RECLAIM);
1865	}
1866
1867	if (count >= budget && may_resched) {
1868		DBG(nm_prlim(1, "out of budget: resched, %d mbufs pending\n",
1869					drbr_inuse(ifp, pq->bufring)));
1870		taskqueue_enqueue(pq->taskq, &pq->task);
1871	}
1872
1873	PTNET_Q_UNLOCK(pq);
1874
1875	return count;
1876}
1877
1878static int
1879ptnet_transmit(if_t ifp, struct mbuf *m)
1880{
1881	struct ptnet_softc *sc = if_getsoftc(ifp);
1882	struct ptnet_queue *pq;
1883	unsigned int queue_idx;
1884	int err;
1885
1886	DBG(device_printf(sc->dev, "transmit %p\n", m));
1887
1888	/* Insert 802.1Q header if needed. */
1889	if (m->m_flags & M_VLANTAG) {
1890		m = ether_vlanencap(m, m->m_pkthdr.ether_vtag);
1891		if (m == NULL) {
1892			return ENOBUFS;
1893		}
1894		m->m_flags &= ~M_VLANTAG;
1895	}
1896
1897	/* Get the flow-id if available. */
1898	queue_idx = (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE) ?
1899		    m->m_pkthdr.flowid : curcpu;
1900
1901	if (unlikely(queue_idx >= sc->num_tx_rings)) {
1902		queue_idx %= sc->num_tx_rings;
1903	}
1904
1905	pq = sc->queues + queue_idx;
1906
1907	err = drbr_enqueue(ifp, pq->bufring, m);
1908	if (err) {
1909		/* ENOBUFS when the bufring is full */
1910		nm_prlim(1, "%s: drbr_enqueue() failed %d\n",
1911			__func__, err);
1912		pq->stats.errors ++;
1913		return err;
1914	}
1915
1916	if (ifp->if_capenable & IFCAP_POLLING) {
1917		/* If polling is on, the transmit queues will be
1918		 * drained by the poller. */
1919		return 0;
1920	}
1921
1922	err = ptnet_drain_transmit_queue(pq, PTNET_TX_BUDGET, true);
1923
1924	return (err < 0) ? err : 0;
1925}
1926
1927static unsigned int
1928ptnet_rx_discard(struct netmap_kring *kring, unsigned int head)
1929{
1930	struct netmap_ring *ring = kring->ring;
1931	struct netmap_slot *slot = ring->slot + head;
1932
1933	for (;;) {
1934		head = nm_next(head, kring->nkr_num_slots - 1);
1935		if (!(slot->flags & NS_MOREFRAG) || head == ring->tail) {
1936			break;
1937		}
1938		slot = ring->slot + head;
1939	}
1940
1941	return head;
1942}
1943
1944static inline struct mbuf *
1945ptnet_rx_slot(struct mbuf *mtail, uint8_t *nmbuf, unsigned int nmbuf_len)
1946{
1947	uint8_t *mdata = mtod(mtail, uint8_t *) + mtail->m_len;
1948
1949	do {
1950		unsigned int copy;
1951
1952		if (mtail->m_len == MCLBYTES) {
1953			struct mbuf *mf;
1954
1955			mf = m_getcl(M_NOWAIT, MT_DATA, 0);
1956			if (unlikely(!mf)) {
1957				return NULL;
1958			}
1959
1960			mtail->m_next = mf;
1961			mtail = mf;
1962			mdata = mtod(mtail, uint8_t *);
1963			mtail->m_len = 0;
1964		}
1965
1966		copy = MCLBYTES - mtail->m_len;
1967		if (nmbuf_len < copy) {
1968			copy = nmbuf_len;
1969		}
1970
1971		memcpy(mdata, nmbuf, copy);
1972
1973		nmbuf += copy;
1974		nmbuf_len -= copy;
1975		mdata += copy;
1976		mtail->m_len += copy;
1977	} while (nmbuf_len);
1978
1979	return mtail;
1980}
1981
1982static int
1983ptnet_rx_eof(struct ptnet_queue *pq, unsigned int budget, bool may_resched)
1984{
1985	struct ptnet_softc *sc = pq->sc;
1986	bool have_vnet_hdr = sc->vnet_hdr_len;
1987	struct nm_csb_atok *atok = pq->atok;
1988	struct nm_csb_ktoa *ktoa = pq->ktoa;
1989	struct netmap_adapter *na = &sc->ptna->dr.up;
1990	struct netmap_kring *kring = na->rx_rings[pq->kring_id];
1991	struct netmap_ring *ring = kring->ring;
1992	unsigned int const lim = kring->nkr_num_slots - 1;
1993	unsigned int batch_count = 0;
1994	if_t ifp = sc->ifp;
1995	unsigned int count = 0;
1996	uint32_t head;
1997
1998	PTNET_Q_LOCK(pq);
1999
2000	if (unlikely(!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
2001		goto unlock;
2002	}
2003
2004	kring->nr_kflags &= ~NKR_PENDINTR;
2005
2006	head = ring->head;
2007	while (count < budget) {
2008		uint32_t prev_head = head;
2009		struct mbuf *mhead, *mtail;
2010		struct virtio_net_hdr *vh;
2011		struct netmap_slot *slot;
2012		unsigned int nmbuf_len;
2013		uint8_t *nmbuf;
2014		int deliver = 1; /* the mbuf to the network stack. */
2015host_sync:
2016		if (head == ring->tail) {
2017			/* We ran out of slot, let's see if the host has
2018			 * added some, by reading hwcur and hwtail from
2019			 * the CSB. */
2020			ptnet_sync_tail(ktoa, kring);
2021
2022			if (head == ring->tail) {
2023				/* Still no slots available. Reactivate
2024				 * interrupts as they were disabled by the
2025				 * host thread right before issuing the
2026				 * last interrupt. */
2027				atok->appl_need_kick = 1;
2028
2029				/* Double check for more completed RX slots.
2030				 * We need a full barrier to prevent the store
2031				 * to atok->appl_need_kick to be reordered with
2032				 * the load from ktoa->hwcur and ktoa->hwtail
2033				 * (store-load barrier). */
2034				nm_stld_barrier();
2035				ptnet_sync_tail(ktoa, kring);
2036				if (likely(head == ring->tail)) {
2037					break;
2038				}
2039				atok->appl_need_kick = 0;
2040			}
2041		}
2042
2043		/* Initialize ring state variables, possibly grabbing the
2044		 * virtio-net header. */
2045		slot = ring->slot + head;
2046		nmbuf = NMB(na, slot);
2047		nmbuf_len = slot->len;
2048
2049		vh = (struct virtio_net_hdr *)nmbuf;
2050		if (have_vnet_hdr) {
2051			if (unlikely(nmbuf_len < PTNET_HDR_SIZE)) {
2052				/* There is no good reason why host should
2053				 * put the header in multiple netmap slots.
2054				 * If this is the case, discard. */
2055				nm_prlim(1, "Fragmented vnet-hdr: dropping");
2056				head = ptnet_rx_discard(kring, head);
2057				pq->stats.iqdrops ++;
2058				deliver = 0;
2059				goto skip;
2060			}
2061			nm_prdis(1, "%s: vnet hdr: flags %x csum_start %u "
2062			      "csum_ofs %u hdr_len = %u gso_size %u "
2063			      "gso_type %x", __func__, vh->flags,
2064			      vh->csum_start, vh->csum_offset, vh->hdr_len,
2065			      vh->gso_size, vh->gso_type);
2066			nmbuf += PTNET_HDR_SIZE;
2067			nmbuf_len -= PTNET_HDR_SIZE;
2068		}
2069
2070		/* Allocate the head of a new mbuf chain.
2071		 * We use m_getcl() to allocate an mbuf with standard cluster
2072		 * size (MCLBYTES). In the future we could use m_getjcl()
2073		 * to choose different sizes. */
2074		mhead = mtail = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2075		if (unlikely(mhead == NULL)) {
2076			device_printf(sc->dev, "%s: failed to allocate mbuf "
2077				      "head\n", __func__);
2078			pq->stats.errors ++;
2079			break;
2080		}
2081
2082		/* Initialize the mbuf state variables. */
2083		mhead->m_pkthdr.len = nmbuf_len;
2084		mtail->m_len = 0;
2085
2086		/* Scan all the netmap slots containing the current packet. */
2087		for (;;) {
2088			DBG(device_printf(sc->dev, "%s: h %u t %u rcv frag "
2089					  "len %u, flags %u\n", __func__,
2090					  head, ring->tail, slot->len,
2091					  slot->flags));
2092
2093			mtail = ptnet_rx_slot(mtail, nmbuf, nmbuf_len);
2094			if (unlikely(!mtail)) {
2095				/* Ouch. We ran out of memory while processing
2096				 * a packet. We have to restore the previous
2097				 * head position, free the mbuf chain, and
2098				 * schedule the taskqueue to give the packet
2099				 * another chance. */
2100				device_printf(sc->dev, "%s: failed to allocate"
2101					" mbuf frag, reset head %u --> %u\n",
2102					__func__, head, prev_head);
2103				head = prev_head;
2104				m_freem(mhead);
2105				pq->stats.errors ++;
2106				if (may_resched) {
2107					taskqueue_enqueue(pq->taskq,
2108							  &pq->task);
2109				}
2110				goto escape;
2111			}
2112
2113			/* We have to increment head irrespective of the
2114			 * NS_MOREFRAG being set or not. */
2115			head = nm_next(head, lim);
2116
2117			if (!(slot->flags & NS_MOREFRAG)) {
2118				break;
2119			}
2120
2121			if (unlikely(head == ring->tail)) {
2122				/* The very last slot prepared by the host has
2123				 * the NS_MOREFRAG set. Drop it and continue
2124				 * the outer cycle (to do the double-check). */
2125				nm_prlim(1, "Incomplete packet: dropping");
2126				m_freem(mhead);
2127				pq->stats.iqdrops ++;
2128				goto host_sync;
2129			}
2130
2131			slot = ring->slot + head;
2132			nmbuf = NMB(na, slot);
2133			nmbuf_len = slot->len;
2134			mhead->m_pkthdr.len += nmbuf_len;
2135		}
2136
2137		mhead->m_pkthdr.rcvif = ifp;
2138		mhead->m_pkthdr.csum_flags = 0;
2139
2140		/* Store the queue idx in the packet header. */
2141		mhead->m_pkthdr.flowid = pq->kring_id;
2142		M_HASHTYPE_SET(mhead, M_HASHTYPE_OPAQUE);
2143
2144		if (ifp->if_capenable & IFCAP_VLAN_HWTAGGING) {
2145			struct ether_header *eh;
2146
2147			eh = mtod(mhead, struct ether_header *);
2148			if (eh->ether_type == htons(ETHERTYPE_VLAN)) {
2149				ptnet_vlan_tag_remove(mhead);
2150				/*
2151				 * With the 802.1Q header removed, update the
2152				 * checksum starting location accordingly.
2153				 */
2154				if (vh->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
2155					vh->csum_start -= ETHER_VLAN_ENCAP_LEN;
2156			}
2157		}
2158
2159		if (have_vnet_hdr && (vh->flags & (VIRTIO_NET_HDR_F_NEEDS_CSUM
2160					| VIRTIO_NET_HDR_F_DATA_VALID))) {
2161			if (unlikely(ptnet_rx_csum(mhead, vh))) {
2162				m_freem(mhead);
2163				nm_prlim(1, "Csum offload error: dropping");
2164				pq->stats.iqdrops ++;
2165				deliver = 0;
2166			}
2167		}
2168
2169skip:
2170		count ++;
2171		if (++batch_count >= PTNET_RX_BATCH) {
2172			/* Some packets have been (or will be) pushed to the network
2173			 * stack. We need to update the CSB to tell the host about
2174			 * the new ring->cur and ring->head (RX buffer refill). */
2175			ptnet_ring_update(pq, kring, head, NAF_FORCE_READ);
2176			batch_count = 0;
2177		}
2178
2179		if (likely(deliver))  {
2180			pq->stats.packets ++;
2181			pq->stats.bytes += mhead->m_pkthdr.len;
2182
2183			PTNET_Q_UNLOCK(pq);
2184			(*ifp->if_input)(ifp, mhead);
2185			PTNET_Q_LOCK(pq);
2186			/* The ring->head index (and related indices) are
2187			 * updated under pq lock by ptnet_ring_update().
2188			 * Since we dropped the lock to call if_input(), we
2189			 * must reload ring->head and restart processing the
2190			 * ring from there. */
2191			head = ring->head;
2192
2193			if (unlikely(!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
2194				/* The interface has gone down while we didn't
2195				 * have the lock. Stop any processing and exit. */
2196				goto unlock;
2197			}
2198		}
2199	}
2200escape:
2201	if (batch_count) {
2202		ptnet_ring_update(pq, kring, head, NAF_FORCE_READ);
2203
2204	}
2205
2206	if (count >= budget && may_resched) {
2207		/* If we ran out of budget or the double-check found new
2208		 * slots to process, schedule the taskqueue. */
2209		DBG(nm_prlim(1, "out of budget: resched h %u t %u\n",
2210					head, ring->tail));
2211		taskqueue_enqueue(pq->taskq, &pq->task);
2212	}
2213unlock:
2214	PTNET_Q_UNLOCK(pq);
2215
2216	return count;
2217}
2218
2219static void
2220ptnet_rx_task(void *context, int pending)
2221{
2222	struct ptnet_queue *pq = context;
2223
2224	DBG(nm_prlim(1, "%s: pq #%u\n", __func__, pq->kring_id));
2225	ptnet_rx_eof(pq, PTNET_RX_BUDGET, true);
2226}
2227
2228static void
2229ptnet_tx_task(void *context, int pending)
2230{
2231	struct ptnet_queue *pq = context;
2232
2233	DBG(nm_prlim(1, "%s: pq #%u\n", __func__, pq->kring_id));
2234	ptnet_drain_transmit_queue(pq, PTNET_TX_BUDGET, true);
2235}
2236
2237#ifdef DEVICE_POLLING
2238/* We don't need to handle differently POLL_AND_CHECK_STATUS and
2239 * POLL_ONLY, since we don't have an Interrupt Status Register. */
2240static int
2241ptnet_poll(if_t ifp, enum poll_cmd cmd, int budget)
2242{
2243	struct ptnet_softc *sc = if_getsoftc(ifp);
2244	unsigned int queue_budget;
2245	unsigned int count = 0;
2246	bool borrow = false;
2247	int i;
2248
2249	KASSERT(sc->num_rings > 0, ("Found no queues in while polling ptnet"));
2250	queue_budget = MAX(budget / sc->num_rings, 1);
2251	nm_prlim(1, "Per-queue budget is %d", queue_budget);
2252
2253	while (budget) {
2254		unsigned int rcnt = 0;
2255
2256		for (i = 0; i < sc->num_rings; i++) {
2257			struct ptnet_queue *pq = sc->queues + i;
2258
2259			if (borrow) {
2260				queue_budget = MIN(queue_budget, budget);
2261				if (queue_budget == 0) {
2262					break;
2263				}
2264			}
2265
2266			if (i < sc->num_tx_rings) {
2267				rcnt += ptnet_drain_transmit_queue(pq,
2268						   queue_budget, false);
2269			} else {
2270				rcnt += ptnet_rx_eof(pq, queue_budget,
2271						      false);
2272			}
2273		}
2274
2275		if (!rcnt) {
2276			/* A scan of the queues gave no result, we can
2277			 * stop here. */
2278			break;
2279		}
2280
2281		if (rcnt > budget) {
2282			/* This may happen when initial budget < sc->num_rings,
2283			 * since one packet budget is given to each queue
2284			 * anyway. Just pretend we didn't eat "so much". */
2285			rcnt = budget;
2286		}
2287		count += rcnt;
2288		budget -= rcnt;
2289		borrow = true;
2290	}
2291
2292
2293	return count;
2294}
2295#endif /* DEVICE_POLLING */
2296#endif /* WITH_PTNETMAP */
2297