xref: /freebsd/sys/dev/netmap/netmap_kern.h (revision 7661de35d15f582ab33e3bd6b8d909601557e436)
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 
66 MALLOC_DECLARE(M_NETMAP);
67 
68 // XXX linux struct, not used in FreeBSD
69 struct net_device_ops {
70 };
71 struct hrtimer {
72 };
73 
74 #elif defined (linux)
75 
76 #define	NM_LOCK_T	safe_spinlock_t	// see bsd_glue.h
77 #define	NM_SELINFO_T	wait_queue_head_t
78 #define	MBUF_LEN(m)	((m)->len)
79 #define	MBUF_IFP(m)	((m)->dev)
80 #define	NM_SEND_UP(ifp, m)  \
81                         do { \
82                             m->priority = NM_MAGIC_PRIORITY; \
83                             netif_rx(m); \
84                         } while (0)
85 
86 #define NM_ATOMIC_T	volatile long unsigned int
87 
88 // XXX a mtx would suffice here too 20130404 gl
89 #define NMG_LOCK_T		struct semaphore
90 #define NMG_LOCK_INIT()		sema_init(&netmap_global_lock, 1)
91 #define NMG_LOCK_DESTROY()
92 #define NMG_LOCK()		down(&netmap_global_lock)
93 #define NMG_UNLOCK()		up(&netmap_global_lock)
94 #define NMG_LOCK_ASSERT()	//	XXX to be completed
95 
96 #ifndef DEV_NETMAP
97 #define DEV_NETMAP
98 #endif /* DEV_NETMAP */
99 
100 /*
101  * IFCAP_NETMAP goes into net_device's priv_flags (if_capenable).
102  * This was 16 bits up to linux 2.6.36, so we need a 16 bit value on older
103  * platforms and tolerate the clash with IFF_DYNAMIC and IFF_BRIDGE_PORT.
104  * For the 32-bit value, 0x100000 has no clashes until at least 3.5.1
105  */
106 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,37)
107 #define IFCAP_NETMAP	0x8000
108 #else
109 #define IFCAP_NETMAP	0x200000
110 #endif
111 
112 #elif defined (__APPLE__)
113 
114 #warning apple support is incomplete.
115 #define likely(x)	__builtin_expect(!!(x), 1)
116 #define unlikely(x)	__builtin_expect(!!(x), 0)
117 #define	NM_LOCK_T	IOLock *
118 #define	NM_SELINFO_T	struct selinfo
119 #define	MBUF_LEN(m)	((m)->m_pkthdr.len)
120 #define	NM_SEND_UP(ifp, m)	((ifp)->if_input)(ifp, m)
121 
122 #else
123 
124 #error unsupported platform
125 
126 #endif /* end - platform-specific code */
127 
128 #define ND(format, ...)
129 #define D(format, ...)						\
130 	do {							\
131 		struct timeval __xxts;				\
132 		microtime(&__xxts);				\
133 		printf("%03d.%06d [%4d] %-25s " format "\n",	\
134 		(int)__xxts.tv_sec % 1000, (int)__xxts.tv_usec,	\
135 		__LINE__, __FUNCTION__, ##__VA_ARGS__);		\
136 	} while (0)
137 
138 /* rate limited, lps indicates how many per second */
139 #define RD(lps, format, ...)					\
140 	do {							\
141 		static int t0, __cnt;				\
142 		if (t0 != time_second) {			\
143 			t0 = time_second;			\
144 			__cnt = 0;				\
145 		}						\
146 		if (__cnt++ < lps)				\
147 			D(format, ##__VA_ARGS__);		\
148 	} while (0)
149 
150 struct netmap_adapter;
151 struct nm_bdg_fwd;
152 struct nm_bridge;
153 struct netmap_priv_d;
154 
155 const char *nm_dump_buf(char *p, int len, int lim, char *dst);
156 
157 #include "netmap_mbq.h"
158 
159 extern NMG_LOCK_T	netmap_global_lock;
160 
161 /*
162  * private, kernel view of a ring. Keeps track of the status of
163  * a ring across system calls.
164  *
165  *	nr_hwcur	index of the next buffer to refill.
166  *			It corresponds to ring->head
167  *			at the time the system call returns.
168  *
169  *	nr_hwtail	index of the first buffer owned by the kernel.
170  *			On RX, hwcur->hwtail are receive buffers
171  *			not yet released. hwcur is advanced following
172  *			ring->head, hwtail is advanced on incoming packets,
173  *			and a wakeup is generated when hwtail passes ring->cur
174  *			    On TX, hwcur->rcur have been filled by the sender
175  *			but not sent yet to the NIC; rcur->hwtail are available
176  *			for new transmissions, and hwtail->hwcur-1 are pending
177  *			transmissions not yet acknowledged.
178  *
179  * The indexes in the NIC and netmap rings are offset by nkr_hwofs slots.
180  * This is so that, on a reset, buffers owned by userspace are not
181  * modified by the kernel. In particular:
182  * RX rings: the next empty buffer (hwtail + hwofs) coincides with
183  * 	the next empty buffer as known by the hardware (next_to_check or so).
184  * TX rings: hwcur + hwofs coincides with next_to_send
185  *
186  * Clients cannot issue concurrent syscall on a ring. The system
187  * detects this and reports an error using two flags,
188  * NKR_WBUSY and NKR_RBUSY
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_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 	 *
444 	 * nm_register() is called on NIOCREGIF and close() to enter
445 	 *	or exit netmap mode on the NIC
446 	 *
447 	 * nm_txsync() pushes packets to the underlying hw/switch
448 	 *
449 	 * nm_rxsync() collects packets from the underlying hw/switch
450 	 *
451 	 * nm_config() returns configuration information from the OS
452 	 *
453 	 * nm_krings_create() create and init the krings array
454 	 * 	(the array layout must conform to the description
455 	 * 	found above the definition of netmap_krings_create)
456 	 *
457 	 * nm_krings_delete() cleanup and delete the kring array
458 	 *
459 	 * nm_notify() is used to act after data have become available.
460 	 *	For hw devices this is typically a selwakeup(),
461 	 *	but for NIC/host ports attached to a switch (or vice-versa)
462 	 *	we also need to invoke the 'txsync' code downstream.
463 	 */
464 
465 	/* private cleanup */
466 	void (*nm_dtor)(struct netmap_adapter *);
467 
468 	int (*nm_register)(struct netmap_adapter *, int onoff);
469 
470 	int (*nm_txsync)(struct netmap_adapter *, u_int ring, int flags);
471 	int (*nm_rxsync)(struct netmap_adapter *, u_int ring, int flags);
472 #define NAF_FORCE_READ    1
473 #define NAF_FORCE_RECLAIM 2
474 	/* return configuration information */
475 	int (*nm_config)(struct netmap_adapter *,
476 		u_int *txr, u_int *txd, u_int *rxr, u_int *rxd);
477 	int (*nm_krings_create)(struct netmap_adapter *);
478 	void (*nm_krings_delete)(struct netmap_adapter *);
479 	int (*nm_notify)(struct netmap_adapter *,
480 		u_int ring, enum txrx, int flags);
481 #define NAF_DISABLE_NOTIFY 8
482 
483 	/* standard refcount to control the lifetime of the adapter
484 	 * (it should be equal to the lifetime of the corresponding ifp)
485 	 */
486 	int na_refcount;
487 
488 	/* memory allocator (opaque)
489 	 * We also cache a pointer to the lut_entry for translating
490 	 * buffer addresses, and the total number of buffers.
491 	 */
492  	struct netmap_mem_d *nm_mem;
493 	struct lut_entry *na_lut;
494 	uint32_t na_lut_objtotal;	/* max buffer index */
495 
496 	/* used internally. If non-null, the interface cannot be bound
497 	 * from userspace
498 	 */
499 	void *na_private;
500 
501 #ifdef WITH_PIPES
502 	struct netmap_pipe_adapter **na_pipes;
503 	int na_next_pipe;
504 	int na_max_pipes;
505 #endif /* WITH_PIPES */
506 };
507 
508 
509 /*
510  * If the NIC is owned by the kernel
511  * (i.e., bridge), neither another bridge nor user can use it;
512  * if the NIC is owned by a user, only users can share it.
513  * Evaluation must be done under NMG_LOCK().
514  */
515 #define NETMAP_OWNED_BY_KERN(na)	(na->na_private)
516 #define NETMAP_OWNED_BY_ANY(na) \
517 	(NETMAP_OWNED_BY_KERN(na) || (na->active_fds > 0))
518 
519 
520 /*
521  * derived netmap adapters for various types of ports
522  */
523 struct netmap_vp_adapter {	/* VALE software port */
524 	struct netmap_adapter up;
525 
526 	/*
527 	 * Bridge support:
528 	 *
529 	 * bdg_port is the port number used in the bridge;
530 	 * na_bdg points to the bridge this NA is attached to.
531 	 */
532 	int bdg_port;
533 	struct nm_bridge *na_bdg;
534 	int retry;
535 
536 	/* Offset of ethernet header for each packet. */
537 	u_int virt_hdr_len;
538 	/* Maximum Frame Size, used in bdg_mismatch_datapath() */
539 	u_int mfs;
540 };
541 
542 
543 struct netmap_hw_adapter {	/* physical device */
544 	struct netmap_adapter up;
545 
546 	struct net_device_ops nm_ndo;	// XXX linux only
547 };
548 
549 /* Mitigation support. */
550 struct nm_generic_mit {
551 	struct hrtimer mit_timer;
552 	int mit_pending;
553 	struct netmap_adapter *mit_na;  /* backpointer */
554 };
555 
556 struct netmap_generic_adapter {	/* emulated device */
557 	struct netmap_hw_adapter up;
558 
559 	/* Pointer to a previously used netmap adapter. */
560 	struct netmap_adapter *prev;
561 
562 	/* generic netmap adapters support:
563 	 * a net_device_ops struct overrides ndo_select_queue(),
564 	 * save_if_input saves the if_input hook (FreeBSD),
565 	 * mit implements rx interrupt mitigation,
566 	 */
567 	struct net_device_ops generic_ndo;
568 	void (*save_if_input)(struct ifnet *, struct mbuf *);
569 
570 	struct nm_generic_mit *mit;
571 #ifdef linux
572         netdev_tx_t (*save_start_xmit)(struct mbuf *, struct ifnet *);
573 #endif
574 };
575 
576 static __inline int
577 netmap_real_tx_rings(struct netmap_adapter *na)
578 {
579 	return na->num_tx_rings + !!(na->na_flags & NAF_HOST_RINGS);
580 }
581 
582 static __inline int
583 netmap_real_rx_rings(struct netmap_adapter *na)
584 {
585 	return na->num_rx_rings + !!(na->na_flags & NAF_HOST_RINGS);
586 }
587 
588 #ifdef WITH_VALE
589 
590 /*
591  * Bridge wrapper for non VALE ports attached to a VALE switch.
592  *
593  * The real device must already have its own netmap adapter (hwna).
594  * The bridge wrapper and the hwna adapter share the same set of
595  * netmap rings and buffers, but they have two separate sets of
596  * krings descriptors, with tx/rx meanings swapped:
597  *
598  *                                  netmap
599  *           bwrap     krings       rings      krings      hwna
600  *         +------+   +------+     +-----+    +------+   +------+
601  *         |tx_rings->|      |\   /|     |----|      |<-tx_rings|
602  *         |      |   +------+ \ / +-----+    +------+   |      |
603  *         |      |             X                        |      |
604  *         |      |            / \                       |      |
605  *         |      |   +------+/   \+-----+    +------+   |      |
606  *         |rx_rings->|      |     |     |----|      |<-rx_rings|
607  *         |      |   +------+     +-----+    +------+   |      |
608  *         +------+                                      +------+
609  *
610  * - packets coming from the bridge go to the brwap rx rings,
611  *   which are also the hwna tx rings.  The bwrap notify callback
612  *   will then complete the hwna tx (see netmap_bwrap_notify).
613  *
614  * - packets coming from the outside go to the hwna rx rings,
615  *   which are also the bwrap tx rings.  The (overwritten) hwna
616  *   notify method will then complete the bridge tx
617  *   (see netmap_bwrap_intr_notify).
618  *
619  *   The bridge wrapper may optionally connect the hwna 'host' rings
620  *   to the bridge. This is done by using a second port in the
621  *   bridge and connecting it to the 'host' netmap_vp_adapter
622  *   contained in the netmap_bwrap_adapter. The brwap host adapter
623  *   cross-links the hwna host rings in the same way as shown above.
624  *
625  * - packets coming from the bridge and directed to the host stack
626  *   are handled by the bwrap host notify callback
627  *   (see netmap_bwrap_host_notify)
628  *
629  * - packets coming from the host stack are still handled by the
630  *   overwritten hwna notify callback (netmap_bwrap_intr_notify),
631  *   but are diverted to the host adapter depending on the ring number.
632  *
633  */
634 struct netmap_bwrap_adapter {
635 	struct netmap_vp_adapter up;
636 	struct netmap_vp_adapter host;  /* for host rings */
637 	struct netmap_adapter *hwna;	/* the underlying device */
638 
639 	/* backup of the hwna notify callback */
640 	int (*save_notify)(struct netmap_adapter *,
641 			u_int ring, enum txrx, int flags);
642 
643 	/*
644 	 * When we attach a physical interface to the bridge, we
645 	 * allow the controlling process to terminate, so we need
646 	 * a place to store the netmap_priv_d data structure.
647 	 * This is only done when physical interfaces
648 	 * are attached to a bridge.
649 	 */
650 	struct netmap_priv_d *na_kpriv;
651 };
652 
653 
654 #endif /* WITH_VALE */
655 
656 #ifdef WITH_PIPES
657 
658 #define NM_MAXPIPES 	64	/* max number of pipes per adapter */
659 
660 struct netmap_pipe_adapter {
661 	struct netmap_adapter up;
662 
663 	u_int id; 	/* pipe identifier */
664 	int role;	/* either NR_REG_PIPE_MASTER or NR_REG_PIPE_SLAVE */
665 
666 	struct netmap_adapter *parent; /* adapter that owns the memory */
667 	struct netmap_pipe_adapter *peer; /* the other end of the pipe */
668 	int peer_ref;		/* 1 iff we are holding a ref to the peer */
669 
670 	u_int parent_slot; /* index in the parent pipe array */
671 };
672 
673 #endif /* WITH_PIPES */
674 
675 
676 /* return slots reserved to rx clients; used in drivers */
677 static inline uint32_t
678 nm_kr_rxspace(struct netmap_kring *k)
679 {
680 	int space = k->nr_hwtail - k->nr_hwcur;
681 	if (space < 0)
682 		space += k->nkr_num_slots;
683 	ND("preserving %d rx slots %d -> %d", space, k->nr_hwcur, k->nr_hwtail);
684 
685 	return space;
686 }
687 
688 
689 /* True if no space in the tx ring. only valid after txsync_prologue */
690 static inline int
691 nm_kr_txempty(struct netmap_kring *kring)
692 {
693 	return kring->rcur == kring->nr_hwtail;
694 }
695 
696 
697 /*
698  * protect against multiple threads using the same ring.
699  * also check that the ring has not been stopped.
700  * We only care for 0 or !=0 as a return code.
701  */
702 #define NM_KR_BUSY	1
703 #define NM_KR_STOPPED	2
704 
705 
706 static __inline void nm_kr_put(struct netmap_kring *kr)
707 {
708 	NM_ATOMIC_CLEAR(&kr->nr_busy);
709 }
710 
711 
712 static __inline int nm_kr_tryget(struct netmap_kring *kr)
713 {
714 	/* check a first time without taking the lock
715 	 * to avoid starvation for nm_kr_get()
716 	 */
717 	if (unlikely(kr->nkr_stopped)) {
718 		ND("ring %p stopped (%d)", kr, kr->nkr_stopped);
719 		return NM_KR_STOPPED;
720 	}
721 	if (unlikely(NM_ATOMIC_TEST_AND_SET(&kr->nr_busy)))
722 		return NM_KR_BUSY;
723 	/* check a second time with lock held */
724 	if (unlikely(kr->nkr_stopped)) {
725 		ND("ring %p stopped (%d)", kr, kr->nkr_stopped);
726 		nm_kr_put(kr);
727 		return NM_KR_STOPPED;
728 	}
729 	return 0;
730 }
731 
732 
733 /*
734  * The following functions are used by individual drivers to
735  * support netmap operation.
736  *
737  * netmap_attach() initializes a struct netmap_adapter, allocating the
738  * 	struct netmap_ring's and the struct selinfo.
739  *
740  * netmap_detach() frees the memory allocated by netmap_attach().
741  *
742  * netmap_transmit() replaces the if_transmit routine of the interface,
743  *	and is used to intercept packets coming from the stack.
744  *
745  * netmap_load_map/netmap_reload_map are helper routines to set/reset
746  *	the dmamap for a packet buffer
747  *
748  * netmap_reset() is a helper routine to be called in the driver
749  *	when reinitializing a ring.
750  */
751 int netmap_attach(struct netmap_adapter *);
752 int netmap_attach_common(struct netmap_adapter *);
753 void netmap_detach_common(struct netmap_adapter *na);
754 void netmap_detach(struct ifnet *);
755 int netmap_transmit(struct ifnet *, struct mbuf *);
756 struct netmap_slot *netmap_reset(struct netmap_adapter *na,
757 	enum txrx tx, u_int n, u_int new_cur);
758 int netmap_ring_reinit(struct netmap_kring *);
759 
760 /* default functions to handle rx/tx interrupts */
761 int netmap_rx_irq(struct ifnet *, u_int, u_int *);
762 #define netmap_tx_irq(_n, _q) netmap_rx_irq(_n, _q, NULL)
763 void netmap_common_irq(struct ifnet *, u_int, u_int *work_done);
764 
765 void netmap_disable_all_rings(struct ifnet *);
766 void netmap_enable_all_rings(struct ifnet *);
767 void netmap_disable_ring(struct netmap_kring *kr);
768 
769 
770 /* set/clear native flags and if_transmit/netdev_ops */
771 static inline void
772 nm_set_native_flags(struct netmap_adapter *na)
773 {
774 	struct ifnet *ifp = na->ifp;
775 
776 	na->na_flags |= (NAF_NATIVE_ON | NAF_NETMAP_ON);
777 #ifdef IFCAP_NETMAP /* or FreeBSD ? */
778 	ifp->if_capenable |= IFCAP_NETMAP;
779 #endif
780 #ifdef __FreeBSD__
781 	na->if_transmit = ifp->if_transmit;
782 	ifp->if_transmit = netmap_transmit;
783 #else
784 	na->if_transmit = (void *)ifp->netdev_ops;
785 	ifp->netdev_ops = &((struct netmap_hw_adapter *)na)->nm_ndo;
786 #endif
787 }
788 
789 
790 static inline void
791 nm_clear_native_flags(struct netmap_adapter *na)
792 {
793 	struct ifnet *ifp = na->ifp;
794 
795 #ifdef __FreeBSD__
796 	ifp->if_transmit = na->if_transmit;
797 #else
798 	ifp->netdev_ops = (void *)na->if_transmit;
799 #endif
800 	na->na_flags &= ~(NAF_NATIVE_ON | NAF_NETMAP_ON);
801 #ifdef IFCAP_NETMAP /* or FreeBSD ? */
802 	ifp->if_capenable &= ~IFCAP_NETMAP;
803 #endif
804 }
805 
806 
807 /*
808  * validates parameters in the ring/kring, returns a value for head
809  * If any error, returns ring_size to force a reinit.
810  */
811 uint32_t nm_txsync_prologue(struct netmap_kring *);
812 
813 
814 /*
815  * validates parameters in the ring/kring, returns a value for head,
816  * and the 'reserved' value in the argument.
817  * If any error, returns ring_size lim to force a reinit.
818  */
819 uint32_t nm_rxsync_prologue(struct netmap_kring *);
820 
821 
822 /*
823  * update kring and ring at the end of txsync.
824  */
825 static inline void
826 nm_txsync_finalize(struct netmap_kring *kring)
827 {
828 	/* update ring tail to what the kernel knows */
829 	kring->ring->tail = kring->rtail = kring->nr_hwtail;
830 
831 	/* note, head/rhead/hwcur might be behind cur/rcur
832 	 * if no carrier
833 	 */
834 	ND(5, "%s now hwcur %d hwtail %d head %d cur %d tail %d",
835 		kring->name, kring->nr_hwcur, kring->nr_hwtail,
836 		kring->rhead, kring->rcur, kring->rtail);
837 }
838 
839 
840 /*
841  * update kring and ring at the end of rxsync
842  */
843 static inline void
844 nm_rxsync_finalize(struct netmap_kring *kring)
845 {
846 	/* tell userspace that there might be new packets */
847 	//struct netmap_ring *ring = kring->ring;
848 	ND("head %d cur %d tail %d -> %d", ring->head, ring->cur, ring->tail,
849 		kring->nr_hwtail);
850 	kring->ring->tail = kring->rtail = kring->nr_hwtail;
851 	/* make a copy of the state for next round */
852 	kring->rhead = kring->ring->head;
853 	kring->rcur = kring->ring->cur;
854 }
855 
856 
857 /* check/fix address and len in tx rings */
858 #if 1 /* debug version */
859 #define	NM_CHECK_ADDR_LEN(_a, _l)	do {				\
860 	if (_a == netmap_buffer_base || _l > NETMAP_BUF_SIZE) {		\
861 		RD(5, "bad addr/len ring %d slot %d idx %d len %d",	\
862 			ring_nr, nm_i, slot->buf_idx, len);		\
863 		if (_l > NETMAP_BUF_SIZE)				\
864 			_l = NETMAP_BUF_SIZE;				\
865 	} } while (0)
866 #else /* no debug version */
867 #define	NM_CHECK_ADDR_LEN(_a, _l)	do {				\
868 		if (_l > NETMAP_BUF_SIZE)				\
869 			_l = NETMAP_BUF_SIZE;				\
870 	} while (0)
871 #endif
872 
873 
874 /*---------------------------------------------------------------*/
875 /*
876  * Support routines to be used with the VALE switch
877  */
878 int netmap_update_config(struct netmap_adapter *na);
879 int netmap_krings_create(struct netmap_adapter *na, u_int tailroom);
880 void netmap_krings_delete(struct netmap_adapter *na);
881 int netmap_rxsync_from_host(struct netmap_adapter *na, struct thread *td, void *pwait);
882 
883 
884 struct netmap_if *
885 netmap_do_regif(struct netmap_priv_d *priv, struct netmap_adapter *na,
886 	uint16_t ringid, uint32_t flags, int *err);
887 
888 
889 
890 u_int nm_bound_var(u_int *v, u_int dflt, u_int lo, u_int hi, const char *msg);
891 int netmap_get_na(struct nmreq *nmr, struct netmap_adapter **na, int create);
892 int netmap_get_hw_na(struct ifnet *ifp, struct netmap_adapter **na);
893 
894 
895 #ifdef WITH_VALE
896 /*
897  * The following bridge-related functions are used by other
898  * kernel modules.
899  *
900  * VALE only supports unicast or broadcast. The lookup
901  * function can return 0 .. NM_BDG_MAXPORTS-1 for regular ports,
902  * NM_BDG_MAXPORTS for broadcast, NM_BDG_MAXPORTS+1 for unknown.
903  * XXX in practice "unknown" might be handled same as broadcast.
904  */
905 typedef u_int (*bdg_lookup_fn_t)(char *buf, u_int len,
906 		uint8_t *ring_nr, struct netmap_vp_adapter *);
907 u_int netmap_bdg_learning(char *, u_int, uint8_t *,
908 		struct netmap_vp_adapter *);
909 
910 #define	NM_BDG_MAXPORTS		254	/* up to 254 */
911 #define	NM_BDG_BROADCAST	NM_BDG_MAXPORTS
912 #define	NM_BDG_NOPORT		(NM_BDG_MAXPORTS+1)
913 
914 #define	NM_NAME			"vale"	/* prefix for bridge port name */
915 
916 
917 /* these are redefined in case of no VALE support */
918 int netmap_get_bdg_na(struct nmreq *nmr, struct netmap_adapter **na, int create);
919 void netmap_init_bridges(void);
920 int netmap_bdg_ctl(struct nmreq *nmr, bdg_lookup_fn_t func);
921 
922 #else /* !WITH_VALE */
923 #define	netmap_get_bdg_na(_1, _2, _3)	0
924 #define netmap_init_bridges(_1)
925 #define	netmap_bdg_ctl(_1, _2)	EINVAL
926 #endif /* !WITH_VALE */
927 
928 #ifdef WITH_PIPES
929 /* max number of pipes per device */
930 #define NM_MAXPIPES	64	/* XXX how many? */
931 /* in case of no error, returns the actual number of pipes in nmr->nr_arg1 */
932 int netmap_pipe_alloc(struct netmap_adapter *, struct nmreq *nmr);
933 void netmap_pipe_dealloc(struct netmap_adapter *);
934 int netmap_get_pipe_na(struct nmreq *nmr, struct netmap_adapter **na, int create);
935 #else /* !WITH_PIPES */
936 #define NM_MAXPIPES	0
937 #define netmap_pipe_alloc(_1, _2) 	EOPNOTSUPP
938 #define netmap_pipe_dealloc(_1)
939 #define netmap_get_pipe_na(_1, _2, _3)	0
940 #endif
941 
942 /* Various prototypes */
943 int netmap_poll(struct cdev *dev, int events, struct thread *td);
944 int netmap_init(void);
945 void netmap_fini(void);
946 int netmap_get_memory(struct netmap_priv_d* p);
947 void netmap_dtor(void *data);
948 int netmap_dtor_locked(struct netmap_priv_d *priv);
949 
950 int netmap_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td);
951 
952 /* netmap_adapter creation/destruction */
953 #define NM_IFPNAME(ifp) ((ifp) ? (ifp)->if_xname : "zombie")
954 
955 // #define NM_DEBUG_PUTGET 1
956 
957 #ifdef NM_DEBUG_PUTGET
958 
959 #define NM_DBG(f) __##f
960 
961 void __netmap_adapter_get(struct netmap_adapter *na);
962 
963 #define netmap_adapter_get(na) 				\
964 	do {						\
965 		struct netmap_adapter *__na = na;	\
966 		D("getting %p:%s (%d)", __na, NM_IFPNAME(__na->ifp), __na->na_refcount);	\
967 		__netmap_adapter_get(__na);		\
968 	} while (0)
969 
970 int __netmap_adapter_put(struct netmap_adapter *na);
971 
972 #define netmap_adapter_put(na)				\
973 	({						\
974 		struct netmap_adapter *__na = na;	\
975 		D("putting %p:%s (%d)", __na, NM_IFPNAME(__na->ifp), __na->na_refcount);	\
976 		__netmap_adapter_put(__na);		\
977 	})
978 
979 #else /* !NM_DEBUG_PUTGET */
980 
981 #define NM_DBG(f) f
982 void netmap_adapter_get(struct netmap_adapter *na);
983 int netmap_adapter_put(struct netmap_adapter *na);
984 
985 #endif /* !NM_DEBUG_PUTGET */
986 
987 
988 /*
989  * module variables
990  */
991 extern u_int netmap_buf_size;
992 #define NETMAP_BUF_SIZE	netmap_buf_size	// XXX remove
993 extern int netmap_mitigate;	// XXX not really used
994 extern int netmap_no_pendintr;
995 extern u_int netmap_total_buffers;	// global allocator
996 extern char *netmap_buffer_base;	// global allocator
997 extern int netmap_verbose;	// XXX debugging
998 enum {                                  /* verbose flags */
999 	NM_VERB_ON = 1,                 /* generic verbose */
1000 	NM_VERB_HOST = 0x2,             /* verbose host stack */
1001 	NM_VERB_RXSYNC = 0x10,          /* verbose on rxsync/txsync */
1002 	NM_VERB_TXSYNC = 0x20,
1003 	NM_VERB_RXINTR = 0x100,         /* verbose on rx/tx intr (driver) */
1004 	NM_VERB_TXINTR = 0x200,
1005 	NM_VERB_NIC_RXSYNC = 0x1000,    /* verbose on rx/tx intr (driver) */
1006 	NM_VERB_NIC_TXSYNC = 0x2000,
1007 };
1008 
1009 extern int netmap_txsync_retry;
1010 extern int netmap_generic_mit;
1011 extern int netmap_generic_ringsize;
1012 extern int netmap_generic_rings;
1013 
1014 /*
1015  * NA returns a pointer to the struct netmap adapter from the ifp,
1016  * WNA is used to write it.
1017  */
1018 #ifndef WNA
1019 #define	WNA(_ifp)	(_ifp)->if_pspare[0]
1020 #endif
1021 #define	NA(_ifp)	((struct netmap_adapter *)WNA(_ifp))
1022 
1023 /*
1024  * Macros to determine if an interface is netmap capable or netmap enabled.
1025  * See the magic field in struct netmap_adapter.
1026  */
1027 #ifdef __FreeBSD__
1028 /*
1029  * on FreeBSD just use if_capabilities and if_capenable.
1030  */
1031 #define NETMAP_CAPABLE(ifp)	(NA(ifp) &&		\
1032 	(ifp)->if_capabilities & IFCAP_NETMAP )
1033 
1034 #define	NETMAP_SET_CAPABLE(ifp)				\
1035 	(ifp)->if_capabilities |= IFCAP_NETMAP
1036 
1037 #else	/* linux */
1038 
1039 /*
1040  * on linux:
1041  * we check if NA(ifp) is set and its first element has a related
1042  * magic value. The capenable is within the struct netmap_adapter.
1043  */
1044 #define	NETMAP_MAGIC	0x52697a7a
1045 
1046 #define NETMAP_CAPABLE(ifp)	(NA(ifp) &&		\
1047 	((uint32_t)(uintptr_t)NA(ifp) ^ NA(ifp)->magic) == NETMAP_MAGIC )
1048 
1049 #define	NETMAP_SET_CAPABLE(ifp)				\
1050 	NA(ifp)->magic = ((uint32_t)(uintptr_t)NA(ifp)) ^ NETMAP_MAGIC
1051 
1052 #endif	/* linux */
1053 
1054 #ifdef __FreeBSD__
1055 
1056 /* Callback invoked by the dma machinery after a successful dmamap_load */
1057 static void netmap_dmamap_cb(__unused void *arg,
1058     __unused bus_dma_segment_t * segs, __unused int nseg, __unused int error)
1059 {
1060 }
1061 
1062 /* bus_dmamap_load wrapper: call aforementioned function if map != NULL.
1063  * XXX can we do it without a callback ?
1064  */
1065 static inline void
1066 netmap_load_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
1067 {
1068 	if (map)
1069 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
1070 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
1071 }
1072 
1073 /* update the map when a buffer changes. */
1074 static inline void
1075 netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
1076 {
1077 	if (map) {
1078 		bus_dmamap_unload(tag, map);
1079 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
1080 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
1081 	}
1082 }
1083 
1084 #else /* linux */
1085 
1086 /*
1087  * XXX How do we redefine these functions:
1088  *
1089  * on linux we need
1090  *	dma_map_single(&pdev->dev, virt_addr, len, direction)
1091  *	dma_unmap_single(&adapter->pdev->dev, phys_addr, len, direction
1092  * The len can be implicit (on netmap it is NETMAP_BUF_SIZE)
1093  * unfortunately the direction is not, so we need to change
1094  * something to have a cross API
1095  */
1096 #define netmap_load_map(_t, _m, _b)
1097 #define netmap_reload_map(_t, _m, _b)
1098 #if 0
1099 	struct e1000_buffer *buffer_info =  &tx_ring->buffer_info[l];
1100 	/* set time_stamp *before* dma to help avoid a possible race */
1101 	buffer_info->time_stamp = jiffies;
1102 	buffer_info->mapped_as_page = false;
1103 	buffer_info->length = len;
1104 	//buffer_info->next_to_watch = l;
1105 	/* reload dma map */
1106 	dma_unmap_single(&adapter->pdev->dev, buffer_info->dma,
1107 			NETMAP_BUF_SIZE, DMA_TO_DEVICE);
1108 	buffer_info->dma = dma_map_single(&adapter->pdev->dev,
1109 			addr, NETMAP_BUF_SIZE, DMA_TO_DEVICE);
1110 
1111 	if (dma_mapping_error(&adapter->pdev->dev, buffer_info->dma)) {
1112 		D("dma mapping error");
1113 		/* goto dma_error; See e1000_put_txbuf() */
1114 		/* XXX reset */
1115 	}
1116 	tx_desc->buffer_addr = htole64(buffer_info->dma); //XXX
1117 
1118 #endif
1119 
1120 /*
1121  * The bus_dmamap_sync() can be one of wmb() or rmb() depending on direction.
1122  */
1123 #define bus_dmamap_sync(_a, _b, _c)
1124 
1125 #endif /* linux */
1126 
1127 
1128 /*
1129  * functions to map NIC to KRING indexes (n2k) and vice versa (k2n)
1130  */
1131 static inline int
1132 netmap_idx_n2k(struct netmap_kring *kr, int idx)
1133 {
1134 	int n = kr->nkr_num_slots;
1135 	idx += kr->nkr_hwofs;
1136 	if (idx < 0)
1137 		return idx + n;
1138 	else if (idx < n)
1139 		return idx;
1140 	else
1141 		return idx - n;
1142 }
1143 
1144 
1145 static inline int
1146 netmap_idx_k2n(struct netmap_kring *kr, int idx)
1147 {
1148 	int n = kr->nkr_num_slots;
1149 	idx -= kr->nkr_hwofs;
1150 	if (idx < 0)
1151 		return idx + n;
1152 	else if (idx < n)
1153 		return idx;
1154 	else
1155 		return idx - n;
1156 }
1157 
1158 
1159 /* Entries of the look-up table. */
1160 struct lut_entry {
1161 	void *vaddr;		/* virtual address. */
1162 	vm_paddr_t paddr;	/* physical address. */
1163 };
1164 
1165 struct netmap_obj_pool;
1166 extern struct lut_entry *netmap_buffer_lut;
1167 #define NMB_VA(i)	(netmap_buffer_lut[i].vaddr)
1168 #define NMB_PA(i)	(netmap_buffer_lut[i].paddr)
1169 
1170 /*
1171  * NMB return the virtual address of a buffer (buffer 0 on bad index)
1172  * PNMB also fills the physical address
1173  */
1174 static inline void *
1175 NMB(struct netmap_slot *slot)
1176 {
1177 	uint32_t i = slot->buf_idx;
1178 	return (unlikely(i >= netmap_total_buffers)) ?  NMB_VA(0) : NMB_VA(i);
1179 }
1180 
1181 static inline void *
1182 PNMB(struct netmap_slot *slot, uint64_t *pp)
1183 {
1184 	uint32_t i = slot->buf_idx;
1185 	void *ret = (i >= netmap_total_buffers) ? NMB_VA(0) : NMB_VA(i);
1186 
1187 	*pp = (i >= netmap_total_buffers) ? NMB_PA(0) : NMB_PA(i);
1188 	return ret;
1189 }
1190 
1191 /* Generic version of NMB, which uses device-specific memory. */
1192 static inline void *
1193 BDG_NMB(struct netmap_adapter *na, struct netmap_slot *slot)
1194 {
1195 	struct lut_entry *lut = na->na_lut;
1196 	uint32_t i = slot->buf_idx;
1197 	return (unlikely(i >= na->na_lut_objtotal)) ?
1198 		lut[0].vaddr : lut[i].vaddr;
1199 }
1200 
1201 
1202 
1203 void netmap_txsync_to_host(struct netmap_adapter *na);
1204 
1205 
1206 /*
1207  * Structure associated to each thread which registered an interface.
1208  *
1209  * The first 4 fields of this structure are written by NIOCREGIF and
1210  * read by poll() and NIOC?XSYNC.
1211  *
1212  * There is low contention among writers (a correct user program
1213  * should have none) and among writers and readers, so we use a
1214  * single global lock to protect the structure initialization;
1215  * since initialization involves the allocation of memory,
1216  * we reuse the memory allocator lock.
1217  *
1218  * Read access to the structure is lock free. Readers must check that
1219  * np_nifp is not NULL before using the other fields.
1220  * If np_nifp is NULL initialization has not been performed,
1221  * so they should return an error to userspace.
1222  *
1223  * The ref_done field is used to regulate access to the refcount in the
1224  * memory allocator. The refcount must be incremented at most once for
1225  * each open("/dev/netmap"). The increment is performed by the first
1226  * function that calls netmap_get_memory() (currently called by
1227  * mmap(), NIOCGINFO and NIOCREGIF).
1228  * If the refcount is incremented, it is then decremented when the
1229  * private structure is destroyed.
1230  */
1231 struct netmap_priv_d {
1232 	struct netmap_if * volatile np_nifp;	/* netmap if descriptor. */
1233 
1234 	struct netmap_adapter	*np_na;
1235 	uint32_t	np_flags;	/* from the ioctl */
1236 	u_int		np_txqfirst, np_txqlast; /* range of tx rings to scan */
1237 	u_int		np_rxqfirst, np_rxqlast; /* range of rx rings to scan */
1238 	uint16_t	np_txpoll;	/* XXX and also np_rxpoll ? */
1239 
1240 	struct netmap_mem_d     *np_mref;	/* use with NMG_LOCK held */
1241 	/* np_refcount is only used on FreeBSD */
1242 	int		np_refcount;	/* use with NMG_LOCK held */
1243 
1244 	/* pointers to the selinfo to be used for selrecord.
1245 	 * Either the local or the global one depending on the
1246 	 * number of rings.
1247 	 */
1248 	NM_SELINFO_T *np_rxsi, *np_txsi;
1249 	struct thread	*np_td;		/* kqueue, just debugging */
1250 };
1251 
1252 
1253 /*
1254  * generic netmap emulation for devices that do not have
1255  * native netmap support.
1256  */
1257 int generic_netmap_attach(struct ifnet *ifp);
1258 
1259 int netmap_catch_rx(struct netmap_adapter *na, int intercept);
1260 void generic_rx_handler(struct ifnet *ifp, struct mbuf *m);;
1261 void netmap_catch_tx(struct netmap_generic_adapter *na, int enable);
1262 int generic_xmit_frame(struct ifnet *ifp, struct mbuf *m, void *addr, u_int len, u_int ring_nr);
1263 int generic_find_num_desc(struct ifnet *ifp, u_int *tx, u_int *rx);
1264 void generic_find_num_queues(struct ifnet *ifp, u_int *txq, u_int *rxq);
1265 
1266 /*
1267  * netmap_mitigation API. This is used by the generic adapter
1268  * to reduce the number of interrupt requests/selwakeup
1269  * to clients on incoming packets.
1270  */
1271 void netmap_mitigation_init(struct nm_generic_mit *mit, struct netmap_adapter *na);
1272 void netmap_mitigation_start(struct nm_generic_mit *mit);
1273 void netmap_mitigation_restart(struct nm_generic_mit *mit);
1274 int netmap_mitigation_active(struct nm_generic_mit *mit);
1275 void netmap_mitigation_cleanup(struct nm_generic_mit *mit);
1276 
1277 
1278 
1279 /* Shared declarations for the VALE switch. */
1280 
1281 /*
1282  * Each transmit queue accumulates a batch of packets into
1283  * a structure before forwarding. Packets to the same
1284  * destination are put in a list using ft_next as a link field.
1285  * ft_frags and ft_next are valid only on the first fragment.
1286  */
1287 struct nm_bdg_fwd {	/* forwarding entry for a bridge */
1288 	void *ft_buf;		/* netmap or indirect buffer */
1289 	uint8_t ft_frags;	/* how many fragments (only on 1st frag) */
1290 	uint8_t _ft_port;	/* dst port (unused) */
1291 	uint16_t ft_flags;	/* flags, e.g. indirect */
1292 	uint16_t ft_len;	/* src fragment len */
1293 	uint16_t ft_next;	/* next packet to same destination */
1294 };
1295 
1296 /* struct 'virtio_net_hdr' from linux. */
1297 struct nm_vnet_hdr {
1298 #define VIRTIO_NET_HDR_F_NEEDS_CSUM     1	/* Use csum_start, csum_offset */
1299 #define VIRTIO_NET_HDR_F_DATA_VALID    2	/* Csum is valid */
1300     uint8_t flags;
1301 #define VIRTIO_NET_HDR_GSO_NONE         0       /* Not a GSO frame */
1302 #define VIRTIO_NET_HDR_GSO_TCPV4        1       /* GSO frame, IPv4 TCP (TSO) */
1303 #define VIRTIO_NET_HDR_GSO_UDP          3       /* GSO frame, IPv4 UDP (UFO) */
1304 #define VIRTIO_NET_HDR_GSO_TCPV6        4       /* GSO frame, IPv6 TCP */
1305 #define VIRTIO_NET_HDR_GSO_ECN          0x80    /* TCP has ECN set */
1306     uint8_t gso_type;
1307     uint16_t hdr_len;
1308     uint16_t gso_size;
1309     uint16_t csum_start;
1310     uint16_t csum_offset;
1311 };
1312 
1313 #define WORST_CASE_GSO_HEADER	(14+40+60)  /* IPv6 + TCP */
1314 
1315 /* Private definitions for IPv4, IPv6, UDP and TCP headers. */
1316 
1317 struct nm_iphdr {
1318 	uint8_t		version_ihl;
1319 	uint8_t		tos;
1320 	uint16_t	tot_len;
1321 	uint16_t	id;
1322 	uint16_t	frag_off;
1323 	uint8_t		ttl;
1324 	uint8_t		protocol;
1325 	uint16_t	check;
1326 	uint32_t	saddr;
1327 	uint32_t	daddr;
1328 	/*The options start here. */
1329 };
1330 
1331 struct nm_tcphdr {
1332 	uint16_t	source;
1333 	uint16_t	dest;
1334 	uint32_t	seq;
1335 	uint32_t	ack_seq;
1336 	uint8_t		doff;  /* Data offset + Reserved */
1337 	uint8_t		flags;
1338 	uint16_t	window;
1339 	uint16_t	check;
1340 	uint16_t	urg_ptr;
1341 };
1342 
1343 struct nm_udphdr {
1344 	uint16_t	source;
1345 	uint16_t	dest;
1346 	uint16_t	len;
1347 	uint16_t	check;
1348 };
1349 
1350 struct nm_ipv6hdr {
1351 	uint8_t		priority_version;
1352 	uint8_t		flow_lbl[3];
1353 
1354 	uint16_t	payload_len;
1355 	uint8_t		nexthdr;
1356 	uint8_t		hop_limit;
1357 
1358 	uint8_t		saddr[16];
1359 	uint8_t		daddr[16];
1360 };
1361 
1362 /* Type used to store a checksum (in host byte order) that hasn't been
1363  * folded yet.
1364  */
1365 #define rawsum_t uint32_t
1366 
1367 rawsum_t nm_csum_raw(uint8_t *data, size_t len, rawsum_t cur_sum);
1368 uint16_t nm_csum_ipv4(struct nm_iphdr *iph);
1369 void nm_csum_tcpudp_ipv4(struct nm_iphdr *iph, void *data,
1370 		      size_t datalen, uint16_t *check);
1371 void nm_csum_tcpudp_ipv6(struct nm_ipv6hdr *ip6h, void *data,
1372 		      size_t datalen, uint16_t *check);
1373 uint16_t nm_csum_fold(rawsum_t cur_sum);
1374 
1375 void bdg_mismatch_datapath(struct netmap_vp_adapter *na,
1376 			   struct netmap_vp_adapter *dst_na,
1377 			   struct nm_bdg_fwd *ft_p, struct netmap_ring *ring,
1378 			   u_int *j, u_int lim, u_int *howmany);
1379 
1380 #endif /* _NET_NETMAP_KERN_H_ */
1381