xref: /freebsd/sys/dev/netmap/netmap_kern.h (revision 95d45410b5100e07f6f98450bcd841a8945d4726)
1 /*
2  * Copyright (C) 2011-2014 Matteo Landi, Luigi Rizzo. All rights reserved.
3  * Copyright (C) 2013-2014 Universita` di Pisa. 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, this list of conditions and the following disclaimer.
10  *   2. Redistributions in binary form must reproduce the above copyright
11  *      notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 /*
28  * $FreeBSD$
29  *
30  * The header contains the definitions of constants and function
31  * prototypes used only in kernelspace.
32  */
33 
34 #ifndef _NET_NETMAP_KERN_H_
35 #define _NET_NETMAP_KERN_H_
36 
37 #define WITH_VALE	// comment out to disable VALE support
38 #define WITH_PIPES
39 
40 #if defined(__FreeBSD__)
41 
42 #define likely(x)	__builtin_expect((long)!!(x), 1L)
43 #define unlikely(x)	__builtin_expect((long)!!(x), 0L)
44 
45 #define	NM_LOCK_T	struct mtx
46 #define	NMG_LOCK_T	struct mtx
47 #define NMG_LOCK_INIT()	mtx_init(&netmap_global_lock, \
48 				"netmap global lock", NULL, MTX_DEF)
49 #define NMG_LOCK_DESTROY()	mtx_destroy(&netmap_global_lock)
50 #define NMG_LOCK()	mtx_lock(&netmap_global_lock)
51 #define NMG_UNLOCK()	mtx_unlock(&netmap_global_lock)
52 #define NMG_LOCK_ASSERT()	mtx_assert(&netmap_global_lock, MA_OWNED)
53 
54 #define	NM_SELINFO_T	struct selinfo
55 #define	MBUF_LEN(m)	((m)->m_pkthdr.len)
56 #define	MBUF_IFP(m)	((m)->m_pkthdr.rcvif)
57 #define	NM_SEND_UP(ifp, m)	((NA(ifp))->if_input)(ifp, m)
58 
59 #define NM_ATOMIC_T	volatile int	// XXX ?
60 /* atomic operations */
61 #include <machine/atomic.h>
62 #define NM_ATOMIC_TEST_AND_SET(p)       (!atomic_cmpset_acq_int((p), 0, 1))
63 #define NM_ATOMIC_CLEAR(p)              atomic_store_rel_int((p), 0)
64 
65 #if __FreeBSD_version >= 1100005
66 struct netmap_adapter *netmap_getna(if_t ifp);
67 #endif
68 
69 MALLOC_DECLARE(M_NETMAP);
70 
71 // XXX linux struct, not used in FreeBSD
72 struct net_device_ops {
73 };
74 struct hrtimer {
75 };
76 
77 #elif defined (linux)
78 
79 #define	NM_LOCK_T	safe_spinlock_t	// see bsd_glue.h
80 #define	NM_SELINFO_T	wait_queue_head_t
81 #define	MBUF_LEN(m)	((m)->len)
82 #define	MBUF_IFP(m)	((m)->dev)
83 #define	NM_SEND_UP(ifp, m)  \
84                         do { \
85                             m->priority = NM_MAGIC_PRIORITY; \
86                             netif_rx(m); \
87                         } while (0)
88 
89 #define NM_ATOMIC_T	volatile long unsigned int
90 
91 // XXX a mtx would suffice here too 20130404 gl
92 #define NMG_LOCK_T		struct semaphore
93 #define NMG_LOCK_INIT()		sema_init(&netmap_global_lock, 1)
94 #define NMG_LOCK_DESTROY()
95 #define NMG_LOCK()		down(&netmap_global_lock)
96 #define NMG_UNLOCK()		up(&netmap_global_lock)
97 #define NMG_LOCK_ASSERT()	//	XXX to be completed
98 
99 #ifndef DEV_NETMAP
100 #define DEV_NETMAP
101 #endif /* DEV_NETMAP */
102 
103 /*
104  * IFCAP_NETMAP goes into net_device's priv_flags (if_capenable).
105  * This was 16 bits up to linux 2.6.36, so we need a 16 bit value on older
106  * platforms and tolerate the clash with IFF_DYNAMIC and IFF_BRIDGE_PORT.
107  * For the 32-bit value, 0x100000 has no clashes until at least 3.5.1
108  */
109 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,37)
110 #define IFCAP_NETMAP	0x8000
111 #else
112 #define IFCAP_NETMAP	0x200000
113 #endif
114 
115 #elif defined (__APPLE__)
116 
117 #warning apple support is incomplete.
118 #define likely(x)	__builtin_expect(!!(x), 1)
119 #define unlikely(x)	__builtin_expect(!!(x), 0)
120 #define	NM_LOCK_T	IOLock *
121 #define	NM_SELINFO_T	struct selinfo
122 #define	MBUF_LEN(m)	((m)->m_pkthdr.len)
123 #define	NM_SEND_UP(ifp, m)	((ifp)->if_input)(ifp, m)
124 
125 #else
126 
127 #error unsupported platform
128 
129 #endif /* end - platform-specific code */
130 
131 #define ND(format, ...)
132 #define D(format, ...)						\
133 	do {							\
134 		struct timeval __xxts;				\
135 		microtime(&__xxts);				\
136 		printf("%03d.%06d [%4d] %-25s " format "\n",	\
137 		(int)__xxts.tv_sec % 1000, (int)__xxts.tv_usec,	\
138 		__LINE__, __FUNCTION__, ##__VA_ARGS__);		\
139 	} while (0)
140 
141 /* rate limited, lps indicates how many per second */
142 #define RD(lps, format, ...)					\
143 	do {							\
144 		static int t0, __cnt;				\
145 		if (t0 != time_second) {			\
146 			t0 = time_second;			\
147 			__cnt = 0;				\
148 		}						\
149 		if (__cnt++ < lps)				\
150 			D(format, ##__VA_ARGS__);		\
151 	} while (0)
152 
153 struct netmap_adapter;
154 struct nm_bdg_fwd;
155 struct nm_bridge;
156 struct netmap_priv_d;
157 
158 const char *nm_dump_buf(char *p, int len, int lim, char *dst);
159 
160 #include "netmap_mbq.h"
161 
162 extern NMG_LOCK_T	netmap_global_lock;
163 
164 /*
165  * private, kernel view of a ring. Keeps track of the status of
166  * a ring across system calls.
167  *
168  *	nr_hwcur	index of the next buffer to refill.
169  *			It corresponds to ring->head
170  *			at the time the system call returns.
171  *
172  *	nr_hwtail	index of the first buffer owned by the kernel.
173  *			On RX, hwcur->hwtail are receive buffers
174  *			not yet released. hwcur is advanced following
175  *			ring->head, hwtail is advanced on incoming packets,
176  *			and a wakeup is generated when hwtail passes ring->cur
177  *			    On TX, hwcur->rcur have been filled by the sender
178  *			but not sent yet to the NIC; rcur->hwtail are available
179  *			for new transmissions, and hwtail->hwcur-1 are pending
180  *			transmissions not yet acknowledged.
181  *
182  * The indexes in the NIC and netmap rings are offset by nkr_hwofs slots.
183  * This is so that, on a reset, buffers owned by userspace are not
184  * modified by the kernel. In particular:
185  * RX rings: the next empty buffer (hwtail + hwofs) coincides with
186  * 	the next empty buffer as known by the hardware (next_to_check or so).
187  * TX rings: hwcur + hwofs coincides with next_to_send
188  *
189  * For received packets, slot->flags is set to nkr_slot_flags
190  * so we can provide a proper initial value (e.g. set NS_FORWARD
191  * when operating in 'transparent' mode).
192  *
193  * The following fields are used to implement lock-free copy of packets
194  * from input to output ports in VALE switch:
195  *	nkr_hwlease	buffer after the last one being copied.
196  *			A writer in nm_bdg_flush reserves N buffers
197  *			from nr_hwlease, advances it, then does the
198  *			copy outside the lock.
199  *			In RX rings (used for VALE ports),
200  *			nkr_hwtail <= nkr_hwlease < nkr_hwcur+N-1
201  *			In TX rings (used for NIC or host stack ports)
202  *			nkr_hwcur <= nkr_hwlease < nkr_hwtail
203  *	nkr_leases	array of nkr_num_slots where writers can report
204  *			completion of their block. NR_NOSLOT (~0) indicates
205  *			that the writer has not finished yet
206  *	nkr_lease_idx	index of next free slot in nr_leases, to be assigned
207  *
208  * The kring is manipulated by txsync/rxsync and generic netmap function.
209  *
210  * Concurrent rxsync or txsync on the same ring are prevented through
211  * by nm_kr_(try)lock() which in turn uses nr_busy. This is all we need
212  * for NIC rings, and for TX rings attached to the host stack.
213  *
214  * RX rings attached to the host stack use an mbq (rx_queue) on both
215  * rxsync_from_host() and netmap_transmit(). The mbq is protected
216  * by its internal lock.
217  *
218  * RX rings attached to the VALE switch are accessed by both sender
219  * and receiver. They are protected through the q_lock on the RX ring.
220  */
221 struct netmap_kring {
222 	struct netmap_ring	*ring;
223 
224 	uint32_t	nr_hwcur;
225 	uint32_t	nr_hwtail;
226 
227 	/*
228 	 * Copies of values in user rings, so we do not need to look
229 	 * at the ring (which could be modified). These are set in the
230 	 * *sync_prologue()/finalize() routines.
231 	 */
232 	uint32_t	rhead;
233 	uint32_t	rcur;
234 	uint32_t	rtail;
235 
236 	uint32_t	nr_kflags;	/* private driver flags */
237 #define NKR_PENDINTR	0x1		// Pending interrupt.
238 	uint32_t	nkr_num_slots;
239 
240 	/*
241 	 * On a NIC reset, the NIC ring indexes may be reset but the
242 	 * indexes in the netmap rings remain the same. nkr_hwofs
243 	 * keeps track of the offset between the two.
244 	 */
245 	int32_t		nkr_hwofs;
246 
247 	uint16_t	nkr_slot_flags;	/* initial value for flags */
248 
249 	/* last_reclaim is opaque marker to help reduce the frequency
250 	 * of operations such as reclaiming tx buffers. A possible use
251 	 * is set it to ticks and do the reclaim only once per tick.
252 	 */
253 	uint64_t	last_reclaim;
254 
255 
256 	NM_SELINFO_T	si;		/* poll/select wait queue */
257 	NM_LOCK_T	q_lock;		/* protects kring and ring. */
258 	NM_ATOMIC_T	nr_busy;	/* prevent concurrent syscalls */
259 
260 	struct netmap_adapter *na;
261 
262 	/* The folloiwing fields are for VALE switch support */
263 	struct nm_bdg_fwd *nkr_ft;
264 	uint32_t	*nkr_leases;
265 #define NR_NOSLOT	((uint32_t)~0)	/* used in nkr_*lease* */
266 	uint32_t	nkr_hwlease;
267 	uint32_t	nkr_lease_idx;
268 
269 	volatile int nkr_stopped;	// XXX what for ?
270 
271 	/* Support for adapters without native netmap support.
272 	 * On tx rings we preallocate an array of tx buffers
273 	 * (same size as the netmap ring), on rx rings we
274 	 * store incoming mbufs in a queue that is drained by
275 	 * a rxsync.
276 	 */
277 	struct mbuf **tx_pool;
278 	// u_int nr_ntc;		/* Emulation of a next-to-clean RX ring pointer. */
279 	struct mbq rx_queue;            /* intercepted rx mbufs. */
280 
281 	uint32_t	ring_id;	/* debugging */
282 	char name[64];			/* diagnostic */
283 
284 	int (*nm_sync)(struct netmap_kring *kring, int flags);
285 
286 #ifdef WITH_PIPES
287 	struct netmap_kring *pipe;
288 	struct netmap_ring *save_ring;
289 #endif /* WITH_PIPES */
290 
291 } __attribute__((__aligned__(64)));
292 
293 
294 /* return the next index, with wraparound */
295 static inline uint32_t
296 nm_next(uint32_t i, uint32_t lim)
297 {
298 	return unlikely (i == lim) ? 0 : i + 1;
299 }
300 
301 
302 /* return the previous index, with wraparound */
303 static inline uint32_t
304 nm_prev(uint32_t i, uint32_t lim)
305 {
306 	return unlikely (i == 0) ? lim : i - 1;
307 }
308 
309 
310 /*
311  *
312  * Here is the layout for the Rx and Tx rings.
313 
314        RxRING                            TxRING
315 
316       +-----------------+            +-----------------+
317       |                 |            |                 |
318       |XXX free slot XXX|            |XXX free slot XXX|
319       +-----------------+            +-----------------+
320 head->| owned by user   |<-hwcur     | not sent to nic |<-hwcur
321       |                 |            | yet             |
322       +-----------------+            |                 |
323  cur->| available to    |            |                 |
324       | user, not read  |            +-----------------+
325       | yet             |       cur->| (being          |
326       |                 |            |  prepared)      |
327       |                 |            |                 |
328       +-----------------+            +     ------      +
329 tail->|                 |<-hwtail    |                 |<-hwlease
330       | (being          | ...        |                 | ...
331       |  prepared)      | ...        |                 | ...
332       +-----------------+ ...        |                 | ...
333       |                 |<-hwlease   +-----------------+
334       |                 |      tail->|                 |<-hwtail
335       |                 |            |                 |
336       |                 |            |                 |
337       |                 |            |                 |
338       +-----------------+            +-----------------+
339 
340  * The cur/tail (user view) and hwcur/hwtail (kernel view)
341  * are used in the normal operation of the card.
342  *
343  * When a ring is the output of a switch port (Rx ring for
344  * a VALE port, Tx ring for the host stack or NIC), slots
345  * are reserved in blocks through 'hwlease' which points
346  * to the next unused slot.
347  * On an Rx ring, hwlease is always after hwtail,
348  * and completions cause hwtail to advance.
349  * On a Tx ring, hwlease is always between cur and hwtail,
350  * and completions cause cur to advance.
351  *
352  * nm_kr_space() returns the maximum number of slots that
353  * can be assigned.
354  * nm_kr_lease() reserves the required number of buffers,
355  *    advances nkr_hwlease and also returns an entry in
356  *    a circular array where completions should be reported.
357  */
358 
359 
360 
361 enum txrx { NR_RX = 0, NR_TX = 1 };
362 
363 /*
364  * The "struct netmap_adapter" extends the "struct adapter"
365  * (or equivalent) device descriptor.
366  * It contains all base fields needed to support netmap operation.
367  * There are in fact different types of netmap adapters
368  * (native, generic, VALE switch...) so a netmap_adapter is
369  * just the first field in the derived type.
370  */
371 struct netmap_adapter {
372 	/*
373 	 * On linux we do not have a good way to tell if an interface
374 	 * is netmap-capable. So we always use the following trick:
375 	 * NA(ifp) points here, and the first entry (which hopefully
376 	 * always exists and is at least 32 bits) contains a magic
377 	 * value which we can use to detect that the interface is good.
378 	 */
379 	uint32_t magic;
380 	uint32_t na_flags;	/* enabled, and other flags */
381 #define NAF_SKIP_INTR	1	/* use the regular interrupt handler.
382 				 * useful during initialization
383 				 */
384 #define NAF_SW_ONLY	2	/* forward packets only to sw adapter */
385 #define NAF_BDG_MAYSLEEP 4	/* the bridge is allowed to sleep when
386 				 * forwarding packets coming from this
387 				 * interface
388 				 */
389 #define NAF_MEM_OWNER	8	/* the adapter is responsible for the
390 				 * deallocation of the memory allocator
391 				 */
392 #define NAF_NATIVE_ON   16      /* the adapter is native and the attached
393 				 * interface is in netmap mode
394 				 */
395 #define	NAF_NETMAP_ON	32	/* netmap is active (either native or
396 				 * emulated. Where possible (e.g. FreeBSD)
397 				 * IFCAP_NETMAP also mirrors this flag.
398 				 */
399 #define NAF_HOST_RINGS  64	/* the adapter supports the host rings */
400 	int active_fds; /* number of user-space descriptors using this
401 			 interface, which is equal to the number of
402 			 struct netmap_if objs in the mapped region. */
403 
404 	u_int num_rx_rings; /* number of adapter receive rings */
405 	u_int num_tx_rings; /* number of adapter transmit rings */
406 
407 	u_int num_tx_desc; /* number of descriptor in each queue */
408 	u_int num_rx_desc;
409 
410 	/* tx_rings and rx_rings are private but allocated
411 	 * as a contiguous chunk of memory. Each array has
412 	 * N+1 entries, for the adapter queues and for the host queue.
413 	 */
414 	struct netmap_kring *tx_rings; /* array of TX rings. */
415 	struct netmap_kring *rx_rings; /* array of RX rings. */
416 
417 	void *tailroom;		       /* space below the rings array */
418 				       /* (used for leases) */
419 
420 
421 	NM_SELINFO_T tx_si, rx_si;	/* global wait queues */
422 
423 	/* count users of the global wait queues */
424 	int tx_si_users, rx_si_users;
425 
426 	/* copy of if_qflush and if_transmit pointers, to intercept
427 	 * packets from the network stack when netmap is active.
428 	 */
429 	int     (*if_transmit)(struct ifnet *, struct mbuf *);
430 
431 	/* copy of if_input for netmap_send_up() */
432 	void     (*if_input)(struct ifnet *, struct mbuf *);
433 
434 	/* references to the ifnet and device routines, used by
435 	 * the generic netmap functions.
436 	 */
437 	struct ifnet *ifp; /* adapter is ifp->if_softc */
438 
439 	/*---- callbacks for this netmap adapter -----*/
440 	/*
441 	 * nm_dtor() is the cleanup routine called when destroying
442 	 *	the adapter.
443 	 *	Called with NMG_LOCK held.
444 	 *
445 	 * nm_register() is called on NIOCREGIF and close() to enter
446 	 *	or exit netmap mode on the NIC
447 	 *	Called with NMG_LOCK held.
448 	 *
449 	 * nm_txsync() pushes packets to the underlying hw/switch
450 	 *
451 	 * nm_rxsync() collects packets from the underlying hw/switch
452 	 *
453 	 * nm_config() returns configuration information from the OS
454 	 *	Called with NMG_LOCK held.
455 	 *
456 	 * nm_krings_create() create and init the krings array
457 	 * 	(the array layout must conform to the description
458 	 * 	found above the definition of netmap_krings_create)
459 	 *
460 	 * nm_krings_delete() cleanup and delete the kring array
461 	 *
462 	 * nm_notify() is used to act after data have become available
463 	 *	(or the stopped state of the ring has changed)
464 	 *	For hw devices this is typically a selwakeup(),
465 	 *	but for NIC/host ports attached to a switch (or vice-versa)
466 	 *	we also need to invoke the 'txsync' code downstream.
467 	 */
468 	void (*nm_dtor)(struct netmap_adapter *);
469 
470 	int (*nm_register)(struct netmap_adapter *, int onoff);
471 
472 	int (*nm_txsync)(struct netmap_adapter *, u_int ring, int flags);
473 	int (*nm_rxsync)(struct netmap_adapter *, u_int ring, int flags);
474 #define NAF_FORCE_READ    1
475 #define NAF_FORCE_RECLAIM 2
476 	/* return configuration information */
477 	int (*nm_config)(struct netmap_adapter *,
478 		u_int *txr, u_int *txd, u_int *rxr, u_int *rxd);
479 	int (*nm_krings_create)(struct netmap_adapter *);
480 	void (*nm_krings_delete)(struct netmap_adapter *);
481 	int (*nm_notify)(struct netmap_adapter *,
482 		u_int ring, enum txrx, int flags);
483 #define NAF_DISABLE_NOTIFY 8
484 
485 	/* standard refcount to control the lifetime of the adapter
486 	 * (it should be equal to the lifetime of the corresponding ifp)
487 	 */
488 	int na_refcount;
489 
490 	/* memory allocator (opaque)
491 	 * We also cache a pointer to the lut_entry for translating
492 	 * buffer addresses, and the total number of buffers.
493 	 */
494  	struct netmap_mem_d *nm_mem;
495 	struct lut_entry *na_lut;
496 	uint32_t na_lut_objtotal;	/* max buffer index */
497 
498 	/* used internally. If non-null, the interface cannot be bound
499 	 * from userspace
500 	 */
501 	void *na_private;
502 
503 #ifdef WITH_PIPES
504 	struct netmap_pipe_adapter **na_pipes;
505 	int na_next_pipe;
506 	int na_max_pipes;
507 #endif /* WITH_PIPES */
508 };
509 
510 
511 /*
512  * If the NIC is owned by the kernel
513  * (i.e., bridge), neither another bridge nor user can use it;
514  * if the NIC is owned by a user, only users can share it.
515  * Evaluation must be done under NMG_LOCK().
516  */
517 #define NETMAP_OWNED_BY_KERN(na)	(na->na_private)
518 #define NETMAP_OWNED_BY_ANY(na) \
519 	(NETMAP_OWNED_BY_KERN(na) || (na->active_fds > 0))
520 
521 
522 /*
523  * derived netmap adapters for various types of ports
524  */
525 struct netmap_vp_adapter {	/* VALE software port */
526 	struct netmap_adapter up;
527 
528 	/*
529 	 * Bridge support:
530 	 *
531 	 * bdg_port is the port number used in the bridge;
532 	 * na_bdg points to the bridge this NA is attached to.
533 	 */
534 	int bdg_port;
535 	struct nm_bridge *na_bdg;
536 	int retry;
537 
538 	/* Offset of ethernet header for each packet. */
539 	u_int virt_hdr_len;
540 	/* Maximum Frame Size, used in bdg_mismatch_datapath() */
541 	u_int mfs;
542 };
543 
544 
545 struct netmap_hw_adapter {	/* physical device */
546 	struct netmap_adapter up;
547 
548 	struct net_device_ops nm_ndo;	// XXX linux only
549 };
550 
551 /* Mitigation support. */
552 struct nm_generic_mit {
553 	struct hrtimer mit_timer;
554 	int mit_pending;
555 	struct netmap_adapter *mit_na;  /* backpointer */
556 };
557 
558 struct netmap_generic_adapter {	/* emulated device */
559 	struct netmap_hw_adapter up;
560 
561 	/* Pointer to a previously used netmap adapter. */
562 	struct netmap_adapter *prev;
563 
564 	/* generic netmap adapters support:
565 	 * a net_device_ops struct overrides ndo_select_queue(),
566 	 * save_if_input saves the if_input hook (FreeBSD),
567 	 * mit implements rx interrupt mitigation,
568 	 */
569 	struct net_device_ops generic_ndo;
570 	void (*save_if_input)(struct ifnet *, struct mbuf *);
571 
572 	struct nm_generic_mit *mit;
573 #ifdef linux
574         netdev_tx_t (*save_start_xmit)(struct mbuf *, struct ifnet *);
575 #endif
576 };
577 
578 static __inline int
579 netmap_real_tx_rings(struct netmap_adapter *na)
580 {
581 	return na->num_tx_rings + !!(na->na_flags & NAF_HOST_RINGS);
582 }
583 
584 static __inline int
585 netmap_real_rx_rings(struct netmap_adapter *na)
586 {
587 	return na->num_rx_rings + !!(na->na_flags & NAF_HOST_RINGS);
588 }
589 
590 #ifdef WITH_VALE
591 
592 /*
593  * Bridge wrapper for non VALE ports attached to a VALE switch.
594  *
595  * The real device must already have its own netmap adapter (hwna).
596  * The bridge wrapper and the hwna adapter share the same set of
597  * netmap rings and buffers, but they have two separate sets of
598  * krings descriptors, with tx/rx meanings swapped:
599  *
600  *                                  netmap
601  *           bwrap     krings       rings      krings      hwna
602  *         +------+   +------+     +-----+    +------+   +------+
603  *         |tx_rings->|      |\   /|     |----|      |<-tx_rings|
604  *         |      |   +------+ \ / +-----+    +------+   |      |
605  *         |      |             X                        |      |
606  *         |      |            / \                       |      |
607  *         |      |   +------+/   \+-----+    +------+   |      |
608  *         |rx_rings->|      |     |     |----|      |<-rx_rings|
609  *         |      |   +------+     +-----+    +------+   |      |
610  *         +------+                                      +------+
611  *
612  * - packets coming from the bridge go to the brwap rx rings,
613  *   which are also the hwna tx rings.  The bwrap notify callback
614  *   will then complete the hwna tx (see netmap_bwrap_notify).
615  *
616  * - packets coming from the outside go to the hwna rx rings,
617  *   which are also the bwrap tx rings.  The (overwritten) hwna
618  *   notify method will then complete the bridge tx
619  *   (see netmap_bwrap_intr_notify).
620  *
621  *   The bridge wrapper may optionally connect the hwna 'host' rings
622  *   to the bridge. This is done by using a second port in the
623  *   bridge and connecting it to the 'host' netmap_vp_adapter
624  *   contained in the netmap_bwrap_adapter. The brwap host adapter
625  *   cross-links the hwna host rings in the same way as shown above.
626  *
627  * - packets coming from the bridge and directed to the host stack
628  *   are handled by the bwrap host notify callback
629  *   (see netmap_bwrap_host_notify)
630  *
631  * - packets coming from the host stack are still handled by the
632  *   overwritten hwna notify callback (netmap_bwrap_intr_notify),
633  *   but are diverted to the host adapter depending on the ring number.
634  *
635  */
636 struct netmap_bwrap_adapter {
637 	struct netmap_vp_adapter up;
638 	struct netmap_vp_adapter host;  /* for host rings */
639 	struct netmap_adapter *hwna;	/* the underlying device */
640 
641 	/* backup of the hwna notify callback */
642 	int (*save_notify)(struct netmap_adapter *,
643 			u_int ring, enum txrx, int flags);
644 
645 	/*
646 	 * When we attach a physical interface to the bridge, we
647 	 * allow the controlling process to terminate, so we need
648 	 * a place to store the netmap_priv_d data structure.
649 	 * This is only done when physical interfaces
650 	 * are attached to a bridge.
651 	 */
652 	struct netmap_priv_d *na_kpriv;
653 };
654 
655 
656 #endif /* WITH_VALE */
657 
658 #ifdef WITH_PIPES
659 
660 #define NM_MAXPIPES 	64	/* max number of pipes per adapter */
661 
662 struct netmap_pipe_adapter {
663 	struct netmap_adapter up;
664 
665 	u_int id; 	/* pipe identifier */
666 	int role;	/* either NR_REG_PIPE_MASTER or NR_REG_PIPE_SLAVE */
667 
668 	struct netmap_adapter *parent; /* adapter that owns the memory */
669 	struct netmap_pipe_adapter *peer; /* the other end of the pipe */
670 	int peer_ref;		/* 1 iff we are holding a ref to the peer */
671 
672 	u_int parent_slot; /* index in the parent pipe array */
673 };
674 
675 #endif /* WITH_PIPES */
676 
677 
678 /* return slots reserved to rx clients; used in drivers */
679 static inline uint32_t
680 nm_kr_rxspace(struct netmap_kring *k)
681 {
682 	int space = k->nr_hwtail - k->nr_hwcur;
683 	if (space < 0)
684 		space += k->nkr_num_slots;
685 	ND("preserving %d rx slots %d -> %d", space, k->nr_hwcur, k->nr_hwtail);
686 
687 	return space;
688 }
689 
690 
691 /* True if no space in the tx ring. only valid after txsync_prologue */
692 static inline int
693 nm_kr_txempty(struct netmap_kring *kring)
694 {
695 	return kring->rcur == kring->nr_hwtail;
696 }
697 
698 
699 /*
700  * protect against multiple threads using the same ring.
701  * also check that the ring has not been stopped.
702  * We only care for 0 or !=0 as a return code.
703  */
704 #define NM_KR_BUSY	1
705 #define NM_KR_STOPPED	2
706 
707 
708 static __inline void nm_kr_put(struct netmap_kring *kr)
709 {
710 	NM_ATOMIC_CLEAR(&kr->nr_busy);
711 }
712 
713 
714 static __inline int nm_kr_tryget(struct netmap_kring *kr)
715 {
716 	/* check a first time without taking the lock
717 	 * to avoid starvation for nm_kr_get()
718 	 */
719 	if (unlikely(kr->nkr_stopped)) {
720 		ND("ring %p stopped (%d)", kr, kr->nkr_stopped);
721 		return NM_KR_STOPPED;
722 	}
723 	if (unlikely(NM_ATOMIC_TEST_AND_SET(&kr->nr_busy)))
724 		return NM_KR_BUSY;
725 	/* check a second time with lock held */
726 	if (unlikely(kr->nkr_stopped)) {
727 		ND("ring %p stopped (%d)", kr, kr->nkr_stopped);
728 		nm_kr_put(kr);
729 		return NM_KR_STOPPED;
730 	}
731 	return 0;
732 }
733 
734 
735 /*
736  * The following functions are used by individual drivers to
737  * support netmap operation.
738  *
739  * netmap_attach() initializes a struct netmap_adapter, allocating the
740  * 	struct netmap_ring's and the struct selinfo.
741  *
742  * netmap_detach() frees the memory allocated by netmap_attach().
743  *
744  * netmap_transmit() replaces the if_transmit routine of the interface,
745  *	and is used to intercept packets coming from the stack.
746  *
747  * netmap_load_map/netmap_reload_map are helper routines to set/reset
748  *	the dmamap for a packet buffer
749  *
750  * netmap_reset() is a helper routine to be called in the driver
751  *	when reinitializing a ring.
752  */
753 int netmap_attach(struct netmap_adapter *);
754 int netmap_attach_common(struct netmap_adapter *);
755 void netmap_detach_common(struct netmap_adapter *na);
756 void netmap_detach(struct ifnet *);
757 int netmap_transmit(struct ifnet *, struct mbuf *);
758 struct netmap_slot *netmap_reset(struct netmap_adapter *na,
759 	enum txrx tx, u_int n, u_int new_cur);
760 int netmap_ring_reinit(struct netmap_kring *);
761 
762 /* default functions to handle rx/tx interrupts */
763 int netmap_rx_irq(struct ifnet *, u_int, u_int *);
764 #define netmap_tx_irq(_n, _q) netmap_rx_irq(_n, _q, NULL)
765 void netmap_common_irq(struct ifnet *, u_int, u_int *work_done);
766 
767 void netmap_disable_all_rings(struct ifnet *);
768 void netmap_enable_all_rings(struct ifnet *);
769 void netmap_disable_ring(struct netmap_kring *kr);
770 
771 
772 /* set/clear native flags and if_transmit/netdev_ops */
773 static inline void
774 nm_set_native_flags(struct netmap_adapter *na)
775 {
776 	struct ifnet *ifp = na->ifp;
777 
778 	na->na_flags |= (NAF_NATIVE_ON | NAF_NETMAP_ON);
779 #ifdef IFCAP_NETMAP /* or FreeBSD ? */
780 	ifp->if_capenable |= IFCAP_NETMAP;
781 #endif
782 #ifdef __FreeBSD__
783 	na->if_transmit = ifp->if_transmit;
784 	ifp->if_transmit = netmap_transmit;
785 #else
786 	na->if_transmit = (void *)ifp->netdev_ops;
787 	ifp->netdev_ops = &((struct netmap_hw_adapter *)na)->nm_ndo;
788 #endif
789 }
790 
791 
792 static inline void
793 nm_clear_native_flags(struct netmap_adapter *na)
794 {
795 	struct ifnet *ifp = na->ifp;
796 
797 #ifdef __FreeBSD__
798 	ifp->if_transmit = na->if_transmit;
799 #else
800 	ifp->netdev_ops = (void *)na->if_transmit;
801 #endif
802 	na->na_flags &= ~(NAF_NATIVE_ON | NAF_NETMAP_ON);
803 #ifdef IFCAP_NETMAP /* or FreeBSD ? */
804 	ifp->if_capenable &= ~IFCAP_NETMAP;
805 #endif
806 }
807 
808 
809 /*
810  * validates parameters in the ring/kring, returns a value for head
811  * If any error, returns ring_size to force a reinit.
812  */
813 uint32_t nm_txsync_prologue(struct netmap_kring *);
814 
815 
816 /*
817  * validates parameters in the ring/kring, returns a value for head,
818  * and the 'reserved' value in the argument.
819  * If any error, returns ring_size lim to force a reinit.
820  */
821 uint32_t nm_rxsync_prologue(struct netmap_kring *);
822 
823 
824 /*
825  * update kring and ring at the end of txsync.
826  */
827 static inline void
828 nm_txsync_finalize(struct netmap_kring *kring)
829 {
830 	/* update ring tail to what the kernel knows */
831 	kring->ring->tail = kring->rtail = kring->nr_hwtail;
832 
833 	/* note, head/rhead/hwcur might be behind cur/rcur
834 	 * if no carrier
835 	 */
836 	ND(5, "%s now hwcur %d hwtail %d head %d cur %d tail %d",
837 		kring->name, kring->nr_hwcur, kring->nr_hwtail,
838 		kring->rhead, kring->rcur, kring->rtail);
839 }
840 
841 
842 /*
843  * update kring and ring at the end of rxsync
844  */
845 static inline void
846 nm_rxsync_finalize(struct netmap_kring *kring)
847 {
848 	/* tell userspace that there might be new packets */
849 	//struct netmap_ring *ring = kring->ring;
850 	ND("head %d cur %d tail %d -> %d", ring->head, ring->cur, ring->tail,
851 		kring->nr_hwtail);
852 	kring->ring->tail = kring->rtail = kring->nr_hwtail;
853 	/* make a copy of the state for next round */
854 	kring->rhead = kring->ring->head;
855 	kring->rcur = kring->ring->cur;
856 }
857 
858 
859 /* check/fix address and len in tx rings */
860 #if 1 /* debug version */
861 #define	NM_CHECK_ADDR_LEN(_a, _l)	do {				\
862 	if (_a == netmap_buffer_base || _l > NETMAP_BUF_SIZE) {		\
863 		RD(5, "bad addr/len ring %d slot %d idx %d len %d",	\
864 			ring_nr, nm_i, slot->buf_idx, len);		\
865 		if (_l > NETMAP_BUF_SIZE)				\
866 			_l = NETMAP_BUF_SIZE;				\
867 	} } while (0)
868 #else /* no debug version */
869 #define	NM_CHECK_ADDR_LEN(_a, _l)	do {				\
870 		if (_l > NETMAP_BUF_SIZE)				\
871 			_l = NETMAP_BUF_SIZE;				\
872 	} while (0)
873 #endif
874 
875 
876 /*---------------------------------------------------------------*/
877 /*
878  * Support routines to be used with the VALE switch
879  */
880 int netmap_update_config(struct netmap_adapter *na);
881 int netmap_krings_create(struct netmap_adapter *na, u_int tailroom);
882 void netmap_krings_delete(struct netmap_adapter *na);
883 int netmap_rxsync_from_host(struct netmap_adapter *na, struct thread *td, void *pwait);
884 
885 
886 struct netmap_if *
887 netmap_do_regif(struct netmap_priv_d *priv, struct netmap_adapter *na,
888 	uint16_t ringid, uint32_t flags, int *err);
889 
890 
891 
892 u_int nm_bound_var(u_int *v, u_int dflt, u_int lo, u_int hi, const char *msg);
893 int netmap_get_na(struct nmreq *nmr, struct netmap_adapter **na, int create);
894 int netmap_get_hw_na(struct ifnet *ifp, struct netmap_adapter **na);
895 
896 
897 #ifdef WITH_VALE
898 /*
899  * The following bridge-related functions are used by other
900  * kernel modules.
901  *
902  * VALE only supports unicast or broadcast. The lookup
903  * function can return 0 .. NM_BDG_MAXPORTS-1 for regular ports,
904  * NM_BDG_MAXPORTS for broadcast, NM_BDG_MAXPORTS+1 for unknown.
905  * XXX in practice "unknown" might be handled same as broadcast.
906  */
907 typedef u_int (*bdg_lookup_fn_t)(char *buf, u_int len,
908 		uint8_t *ring_nr, struct netmap_vp_adapter *);
909 u_int netmap_bdg_learning(char *, u_int, uint8_t *,
910 		struct netmap_vp_adapter *);
911 
912 #define	NM_BDG_MAXPORTS		254	/* up to 254 */
913 #define	NM_BDG_BROADCAST	NM_BDG_MAXPORTS
914 #define	NM_BDG_NOPORT		(NM_BDG_MAXPORTS+1)
915 
916 #define	NM_NAME			"vale"	/* prefix for bridge port name */
917 
918 
919 /* these are redefined in case of no VALE support */
920 int netmap_get_bdg_na(struct nmreq *nmr, struct netmap_adapter **na, int create);
921 void netmap_init_bridges(void);
922 int netmap_bdg_ctl(struct nmreq *nmr, bdg_lookup_fn_t func);
923 
924 #else /* !WITH_VALE */
925 #define	netmap_get_bdg_na(_1, _2, _3)	0
926 #define netmap_init_bridges(_1)
927 #define	netmap_bdg_ctl(_1, _2)	EINVAL
928 #endif /* !WITH_VALE */
929 
930 #ifdef WITH_PIPES
931 /* max number of pipes per device */
932 #define NM_MAXPIPES	64	/* XXX how many? */
933 /* in case of no error, returns the actual number of pipes in nmr->nr_arg1 */
934 int netmap_pipe_alloc(struct netmap_adapter *, struct nmreq *nmr);
935 void netmap_pipe_dealloc(struct netmap_adapter *);
936 int netmap_get_pipe_na(struct nmreq *nmr, struct netmap_adapter **na, int create);
937 #else /* !WITH_PIPES */
938 #define NM_MAXPIPES	0
939 #define netmap_pipe_alloc(_1, _2) 	EOPNOTSUPP
940 #define netmap_pipe_dealloc(_1)
941 #define netmap_get_pipe_na(_1, _2, _3)	0
942 #endif
943 
944 /* Various prototypes */
945 int netmap_poll(struct cdev *dev, int events, struct thread *td);
946 int netmap_init(void);
947 void netmap_fini(void);
948 int netmap_get_memory(struct netmap_priv_d* p);
949 void netmap_dtor(void *data);
950 int netmap_dtor_locked(struct netmap_priv_d *priv);
951 
952 int netmap_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td);
953 
954 /* netmap_adapter creation/destruction */
955 #define NM_IFPNAME(ifp) ((ifp) ? (ifp)->if_xname : "zombie")
956 
957 // #define NM_DEBUG_PUTGET 1
958 
959 #ifdef NM_DEBUG_PUTGET
960 
961 #define NM_DBG(f) __##f
962 
963 void __netmap_adapter_get(struct netmap_adapter *na);
964 
965 #define netmap_adapter_get(na) 				\
966 	do {						\
967 		struct netmap_adapter *__na = na;	\
968 		D("getting %p:%s (%d)", __na, NM_IFPNAME(__na->ifp), __na->na_refcount);	\
969 		__netmap_adapter_get(__na);		\
970 	} while (0)
971 
972 int __netmap_adapter_put(struct netmap_adapter *na);
973 
974 #define netmap_adapter_put(na)				\
975 	({						\
976 		struct netmap_adapter *__na = na;	\
977 		D("putting %p:%s (%d)", __na, NM_IFPNAME(__na->ifp), __na->na_refcount);	\
978 		__netmap_adapter_put(__na);		\
979 	})
980 
981 #else /* !NM_DEBUG_PUTGET */
982 
983 #define NM_DBG(f) f
984 void netmap_adapter_get(struct netmap_adapter *na);
985 int netmap_adapter_put(struct netmap_adapter *na);
986 
987 #endif /* !NM_DEBUG_PUTGET */
988 
989 
990 /*
991  * module variables
992  */
993 extern u_int netmap_buf_size;
994 #define NETMAP_BUF_SIZE	netmap_buf_size	// XXX remove
995 extern int netmap_mitigate;	// XXX not really used
996 extern int netmap_no_pendintr;
997 extern u_int netmap_total_buffers;	// global allocator
998 extern char *netmap_buffer_base;	// global allocator
999 extern int netmap_verbose;	// XXX debugging
1000 enum {                                  /* verbose flags */
1001 	NM_VERB_ON = 1,                 /* generic verbose */
1002 	NM_VERB_HOST = 0x2,             /* verbose host stack */
1003 	NM_VERB_RXSYNC = 0x10,          /* verbose on rxsync/txsync */
1004 	NM_VERB_TXSYNC = 0x20,
1005 	NM_VERB_RXINTR = 0x100,         /* verbose on rx/tx intr (driver) */
1006 	NM_VERB_TXINTR = 0x200,
1007 	NM_VERB_NIC_RXSYNC = 0x1000,    /* verbose on rx/tx intr (driver) */
1008 	NM_VERB_NIC_TXSYNC = 0x2000,
1009 };
1010 
1011 extern int netmap_txsync_retry;
1012 extern int netmap_generic_mit;
1013 extern int netmap_generic_ringsize;
1014 extern int netmap_generic_rings;
1015 
1016 /*
1017  * NA returns a pointer to the struct netmap adapter from the ifp,
1018  * WNA is used to write it.
1019  */
1020 #ifndef WNA
1021 #define	WNA(_ifp)	(_ifp)->if_pspare[0]
1022 #endif
1023 #define	NA(_ifp)	((struct netmap_adapter *)WNA(_ifp))
1024 
1025 /*
1026  * Macros to determine if an interface is netmap capable or netmap enabled.
1027  * See the magic field in struct netmap_adapter.
1028  */
1029 #ifdef __FreeBSD__
1030 /*
1031  * on FreeBSD just use if_capabilities and if_capenable.
1032  */
1033 #define NETMAP_CAPABLE(ifp)	(NA(ifp) &&		\
1034 	(ifp)->if_capabilities & IFCAP_NETMAP )
1035 
1036 #define	NETMAP_SET_CAPABLE(ifp)				\
1037 	(ifp)->if_capabilities |= IFCAP_NETMAP
1038 
1039 #else	/* linux */
1040 
1041 /*
1042  * on linux:
1043  * we check if NA(ifp) is set and its first element has a related
1044  * magic value. The capenable is within the struct netmap_adapter.
1045  */
1046 #define	NETMAP_MAGIC	0x52697a7a
1047 
1048 #define NETMAP_CAPABLE(ifp)	(NA(ifp) &&		\
1049 	((uint32_t)(uintptr_t)NA(ifp) ^ NA(ifp)->magic) == NETMAP_MAGIC )
1050 
1051 #define	NETMAP_SET_CAPABLE(ifp)				\
1052 	NA(ifp)->magic = ((uint32_t)(uintptr_t)NA(ifp)) ^ NETMAP_MAGIC
1053 
1054 #endif	/* linux */
1055 
1056 #ifdef __FreeBSD__
1057 
1058 /* Callback invoked by the dma machinery after a successful dmamap_load */
1059 static void netmap_dmamap_cb(__unused void *arg,
1060     __unused bus_dma_segment_t * segs, __unused int nseg, __unused int error)
1061 {
1062 }
1063 
1064 /* bus_dmamap_load wrapper: call aforementioned function if map != NULL.
1065  * XXX can we do it without a callback ?
1066  */
1067 static inline void
1068 netmap_load_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
1069 {
1070 	if (map)
1071 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
1072 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
1073 }
1074 
1075 /* update the map when a buffer changes. */
1076 static inline void
1077 netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
1078 {
1079 	if (map) {
1080 		bus_dmamap_unload(tag, map);
1081 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
1082 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
1083 	}
1084 }
1085 
1086 #else /* linux */
1087 
1088 /*
1089  * XXX How do we redefine these functions:
1090  *
1091  * on linux we need
1092  *	dma_map_single(&pdev->dev, virt_addr, len, direction)
1093  *	dma_unmap_single(&adapter->pdev->dev, phys_addr, len, direction
1094  * The len can be implicit (on netmap it is NETMAP_BUF_SIZE)
1095  * unfortunately the direction is not, so we need to change
1096  * something to have a cross API
1097  */
1098 #define netmap_load_map(_t, _m, _b)
1099 #define netmap_reload_map(_t, _m, _b)
1100 #if 0
1101 	struct e1000_buffer *buffer_info =  &tx_ring->buffer_info[l];
1102 	/* set time_stamp *before* dma to help avoid a possible race */
1103 	buffer_info->time_stamp = jiffies;
1104 	buffer_info->mapped_as_page = false;
1105 	buffer_info->length = len;
1106 	//buffer_info->next_to_watch = l;
1107 	/* reload dma map */
1108 	dma_unmap_single(&adapter->pdev->dev, buffer_info->dma,
1109 			NETMAP_BUF_SIZE, DMA_TO_DEVICE);
1110 	buffer_info->dma = dma_map_single(&adapter->pdev->dev,
1111 			addr, NETMAP_BUF_SIZE, DMA_TO_DEVICE);
1112 
1113 	if (dma_mapping_error(&adapter->pdev->dev, buffer_info->dma)) {
1114 		D("dma mapping error");
1115 		/* goto dma_error; See e1000_put_txbuf() */
1116 		/* XXX reset */
1117 	}
1118 	tx_desc->buffer_addr = htole64(buffer_info->dma); //XXX
1119 
1120 #endif
1121 
1122 /*
1123  * The bus_dmamap_sync() can be one of wmb() or rmb() depending on direction.
1124  */
1125 #define bus_dmamap_sync(_a, _b, _c)
1126 
1127 #endif /* linux */
1128 
1129 
1130 /*
1131  * functions to map NIC to KRING indexes (n2k) and vice versa (k2n)
1132  */
1133 static inline int
1134 netmap_idx_n2k(struct netmap_kring *kr, int idx)
1135 {
1136 	int n = kr->nkr_num_slots;
1137 	idx += kr->nkr_hwofs;
1138 	if (idx < 0)
1139 		return idx + n;
1140 	else if (idx < n)
1141 		return idx;
1142 	else
1143 		return idx - n;
1144 }
1145 
1146 
1147 static inline int
1148 netmap_idx_k2n(struct netmap_kring *kr, int idx)
1149 {
1150 	int n = kr->nkr_num_slots;
1151 	idx -= kr->nkr_hwofs;
1152 	if (idx < 0)
1153 		return idx + n;
1154 	else if (idx < n)
1155 		return idx;
1156 	else
1157 		return idx - n;
1158 }
1159 
1160 
1161 /* Entries of the look-up table. */
1162 struct lut_entry {
1163 	void *vaddr;		/* virtual address. */
1164 	vm_paddr_t paddr;	/* physical address. */
1165 };
1166 
1167 struct netmap_obj_pool;
1168 extern struct lut_entry *netmap_buffer_lut;
1169 #define NMB_VA(i)	(netmap_buffer_lut[i].vaddr)
1170 #define NMB_PA(i)	(netmap_buffer_lut[i].paddr)
1171 
1172 /*
1173  * NMB return the virtual address of a buffer (buffer 0 on bad index)
1174  * PNMB also fills the physical address
1175  */
1176 static inline void *
1177 NMB(struct netmap_slot *slot)
1178 {
1179 	uint32_t i = slot->buf_idx;
1180 	return (unlikely(i >= netmap_total_buffers)) ?  NMB_VA(0) : NMB_VA(i);
1181 }
1182 
1183 static inline void *
1184 PNMB(struct netmap_slot *slot, uint64_t *pp)
1185 {
1186 	uint32_t i = slot->buf_idx;
1187 	void *ret = (i >= netmap_total_buffers) ? NMB_VA(0) : NMB_VA(i);
1188 
1189 	*pp = (i >= netmap_total_buffers) ? NMB_PA(0) : NMB_PA(i);
1190 	return ret;
1191 }
1192 
1193 /* Generic version of NMB, which uses device-specific memory. */
1194 static inline void *
1195 BDG_NMB(struct netmap_adapter *na, struct netmap_slot *slot)
1196 {
1197 	struct lut_entry *lut = na->na_lut;
1198 	uint32_t i = slot->buf_idx;
1199 	return (unlikely(i >= na->na_lut_objtotal)) ?
1200 		lut[0].vaddr : lut[i].vaddr;
1201 }
1202 
1203 
1204 
1205 void netmap_txsync_to_host(struct netmap_adapter *na);
1206 
1207 
1208 /*
1209  * Structure associated to each thread which registered an interface.
1210  *
1211  * The first 4 fields of this structure are written by NIOCREGIF and
1212  * read by poll() and NIOC?XSYNC.
1213  *
1214  * There is low contention among writers (a correct user program
1215  * should have none) and among writers and readers, so we use a
1216  * single global lock to protect the structure initialization;
1217  * since initialization involves the allocation of memory,
1218  * we reuse the memory allocator lock.
1219  *
1220  * Read access to the structure is lock free. Readers must check that
1221  * np_nifp is not NULL before using the other fields.
1222  * If np_nifp is NULL initialization has not been performed,
1223  * so they should return an error to userspace.
1224  *
1225  * The ref_done field is used to regulate access to the refcount in the
1226  * memory allocator. The refcount must be incremented at most once for
1227  * each open("/dev/netmap"). The increment is performed by the first
1228  * function that calls netmap_get_memory() (currently called by
1229  * mmap(), NIOCGINFO and NIOCREGIF).
1230  * If the refcount is incremented, it is then decremented when the
1231  * private structure is destroyed.
1232  */
1233 struct netmap_priv_d {
1234 	struct netmap_if * volatile np_nifp;	/* netmap if descriptor. */
1235 
1236 	struct netmap_adapter	*np_na;
1237 	uint32_t	np_flags;	/* from the ioctl */
1238 	u_int		np_txqfirst, np_txqlast; /* range of tx rings to scan */
1239 	u_int		np_rxqfirst, np_rxqlast; /* range of rx rings to scan */
1240 	uint16_t	np_txpoll;	/* XXX and also np_rxpoll ? */
1241 
1242 	struct netmap_mem_d     *np_mref;	/* use with NMG_LOCK held */
1243 	/* np_refcount is only used on FreeBSD */
1244 	int		np_refcount;	/* use with NMG_LOCK held */
1245 
1246 	/* pointers to the selinfo to be used for selrecord.
1247 	 * Either the local or the global one depending on the
1248 	 * number of rings.
1249 	 */
1250 	NM_SELINFO_T *np_rxsi, *np_txsi;
1251 	struct thread	*np_td;		/* kqueue, just debugging */
1252 };
1253 
1254 
1255 /*
1256  * generic netmap emulation for devices that do not have
1257  * native netmap support.
1258  */
1259 int generic_netmap_attach(struct ifnet *ifp);
1260 
1261 int netmap_catch_rx(struct netmap_adapter *na, int intercept);
1262 void generic_rx_handler(struct ifnet *ifp, struct mbuf *m);;
1263 void netmap_catch_tx(struct netmap_generic_adapter *na, int enable);
1264 int generic_xmit_frame(struct ifnet *ifp, struct mbuf *m, void *addr, u_int len, u_int ring_nr);
1265 int generic_find_num_desc(struct ifnet *ifp, u_int *tx, u_int *rx);
1266 void generic_find_num_queues(struct ifnet *ifp, u_int *txq, u_int *rxq);
1267 
1268 /*
1269  * netmap_mitigation API. This is used by the generic adapter
1270  * to reduce the number of interrupt requests/selwakeup
1271  * to clients on incoming packets.
1272  */
1273 void netmap_mitigation_init(struct nm_generic_mit *mit, struct netmap_adapter *na);
1274 void netmap_mitigation_start(struct nm_generic_mit *mit);
1275 void netmap_mitigation_restart(struct nm_generic_mit *mit);
1276 int netmap_mitigation_active(struct nm_generic_mit *mit);
1277 void netmap_mitigation_cleanup(struct nm_generic_mit *mit);
1278 
1279 
1280 
1281 /* Shared declarations for the VALE switch. */
1282 
1283 /*
1284  * Each transmit queue accumulates a batch of packets into
1285  * a structure before forwarding. Packets to the same
1286  * destination are put in a list using ft_next as a link field.
1287  * ft_frags and ft_next are valid only on the first fragment.
1288  */
1289 struct nm_bdg_fwd {	/* forwarding entry for a bridge */
1290 	void *ft_buf;		/* netmap or indirect buffer */
1291 	uint8_t ft_frags;	/* how many fragments (only on 1st frag) */
1292 	uint8_t _ft_port;	/* dst port (unused) */
1293 	uint16_t ft_flags;	/* flags, e.g. indirect */
1294 	uint16_t ft_len;	/* src fragment len */
1295 	uint16_t ft_next;	/* next packet to same destination */
1296 };
1297 
1298 /* struct 'virtio_net_hdr' from linux. */
1299 struct nm_vnet_hdr {
1300 #define VIRTIO_NET_HDR_F_NEEDS_CSUM     1	/* Use csum_start, csum_offset */
1301 #define VIRTIO_NET_HDR_F_DATA_VALID    2	/* Csum is valid */
1302     uint8_t flags;
1303 #define VIRTIO_NET_HDR_GSO_NONE         0       /* Not a GSO frame */
1304 #define VIRTIO_NET_HDR_GSO_TCPV4        1       /* GSO frame, IPv4 TCP (TSO) */
1305 #define VIRTIO_NET_HDR_GSO_UDP          3       /* GSO frame, IPv4 UDP (UFO) */
1306 #define VIRTIO_NET_HDR_GSO_TCPV6        4       /* GSO frame, IPv6 TCP */
1307 #define VIRTIO_NET_HDR_GSO_ECN          0x80    /* TCP has ECN set */
1308     uint8_t gso_type;
1309     uint16_t hdr_len;
1310     uint16_t gso_size;
1311     uint16_t csum_start;
1312     uint16_t csum_offset;
1313 };
1314 
1315 #define WORST_CASE_GSO_HEADER	(14+40+60)  /* IPv6 + TCP */
1316 
1317 /* Private definitions for IPv4, IPv6, UDP and TCP headers. */
1318 
1319 struct nm_iphdr {
1320 	uint8_t		version_ihl;
1321 	uint8_t		tos;
1322 	uint16_t	tot_len;
1323 	uint16_t	id;
1324 	uint16_t	frag_off;
1325 	uint8_t		ttl;
1326 	uint8_t		protocol;
1327 	uint16_t	check;
1328 	uint32_t	saddr;
1329 	uint32_t	daddr;
1330 	/*The options start here. */
1331 };
1332 
1333 struct nm_tcphdr {
1334 	uint16_t	source;
1335 	uint16_t	dest;
1336 	uint32_t	seq;
1337 	uint32_t	ack_seq;
1338 	uint8_t		doff;  /* Data offset + Reserved */
1339 	uint8_t		flags;
1340 	uint16_t	window;
1341 	uint16_t	check;
1342 	uint16_t	urg_ptr;
1343 };
1344 
1345 struct nm_udphdr {
1346 	uint16_t	source;
1347 	uint16_t	dest;
1348 	uint16_t	len;
1349 	uint16_t	check;
1350 };
1351 
1352 struct nm_ipv6hdr {
1353 	uint8_t		priority_version;
1354 	uint8_t		flow_lbl[3];
1355 
1356 	uint16_t	payload_len;
1357 	uint8_t		nexthdr;
1358 	uint8_t		hop_limit;
1359 
1360 	uint8_t		saddr[16];
1361 	uint8_t		daddr[16];
1362 };
1363 
1364 /* Type used to store a checksum (in host byte order) that hasn't been
1365  * folded yet.
1366  */
1367 #define rawsum_t uint32_t
1368 
1369 rawsum_t nm_csum_raw(uint8_t *data, size_t len, rawsum_t cur_sum);
1370 uint16_t nm_csum_ipv4(struct nm_iphdr *iph);
1371 void nm_csum_tcpudp_ipv4(struct nm_iphdr *iph, void *data,
1372 		      size_t datalen, uint16_t *check);
1373 void nm_csum_tcpudp_ipv6(struct nm_ipv6hdr *ip6h, void *data,
1374 		      size_t datalen, uint16_t *check);
1375 uint16_t nm_csum_fold(rawsum_t cur_sum);
1376 
1377 void bdg_mismatch_datapath(struct netmap_vp_adapter *na,
1378 			   struct netmap_vp_adapter *dst_na,
1379 			   struct nm_bdg_fwd *ft_p, struct netmap_ring *ring,
1380 			   u_int *j, u_int lim, u_int *howmany);
1381 #endif /* _NET_NETMAP_KERN_H_ */
1382