xref: /dragonfly/sys/net/netmap/netmap_kern.h (revision e6d22e9b)
1 /*
2  * Copyright (C) 2011-2013 Matteo Landi, Luigi Rizzo. All rights reserved.
3  * Copyright (C) 2013 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: head/sys/dev/netmap/netmap_kern.h 238985 2012-08-02 11:59:43Z luigi $
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 
39 #define likely(x)	__builtin_expect((long)!!(x), 1L)
40 #define unlikely(x)	__builtin_expect((long)!!(x), 0L)
41 
42 #define	NM_LOCK_T	struct lock
43 #define	NMG_LOCK_T	struct lock
44 #define NMG_LOCK_INIT()	lockinit(&netmap_global_lock, \
45 				"netmap global lock", 0, LK_CANRECURSE)
46 #define NMG_LOCK_DESTROY()	lockuninit(&netmap_global_lock)
47 #define NMG_LOCK()	lockmgr(&netmap_global_lock, LK_EXCLUSIVE)
48 #define NMG_UNLOCK()	lockmgr(&netmap_global_lock, LK_RELEASE)
49 #define NMG_LOCK_ASSERT()	KKASSERT(lockstatus(&netmap_global_lock, NULL) != 0)
50 
51 #define	NM_SELINFO_T	struct kqinfo
52 #define	MBUF_LEN(m)	((m)->m_pkthdr.len)
53 #define	MBUF_IFP(m)	((m)->m_pkthdr.rcvif)
54 #define	NM_SEND_UP(ifp, m)	((ifp)->if_input(ifp, m, NULL, -1))
55 
56 #define NM_ATOMIC_T	volatile int	// XXX ?
57 /* atomic operations */
58 #include <machine/atomic.h>
59 #define NM_ATOMIC_TEST_AND_SET(p)       (!atomic_cmpset_acq_int((p), 0, 1))
60 #define NM_ATOMIC_CLEAR(p)              atomic_store_rel_int((p), 0)
61 
62 #define prefetch(x)     __builtin_prefetch(x)
63 
64 #define mb()	cpu_mfence()
65 #define rmb()	cpu_lfence()
66 #define wmb()	cpu_sfence()
67 
68 #ifdef MALLOC_DECLARE
69 MALLOC_DECLARE(M_NETMAP);
70 #endif
71 
72 // XXX linux struct, not used in FreeBSD
73 struct net_device_ops {
74 };
75 struct hrtimer {
76 };
77 
78 #define IFCAP_NETMAP	0x8000	/* XXX move to <net/if.h> */
79 
80 #define ND(format, ...)
81 #define D(format, ...)						\
82 	do {							\
83 		struct timeval __xxts;				\
84 		microtime(&__xxts);				\
85 		kprintf("%03d.%06d %s [%d] " format "\n",	\
86 		(int)__xxts.tv_sec % 1000, (int)__xxts.tv_usec,	\
87 		__FUNCTION__, __LINE__, ##__VA_ARGS__);		\
88 	} while (0)
89 
90 /* rate limited, lps indicates how many per second */
91 #define RD(lps, format, ...)					\
92 	do {							\
93 		static int t0, __cnt;				\
94 		if (t0 != time_second) {			\
95 			t0 = time_second;			\
96 			__cnt = 0;				\
97 		}						\
98 		if (__cnt++ < lps)				\
99 			D(format, ##__VA_ARGS__);		\
100 	} while (0)
101 
102 struct netmap_adapter;
103 struct nm_bdg_fwd;
104 struct nm_bridge;
105 struct netmap_priv_d;
106 
107 const char *nm_dump_buf(char *p, int len, int lim, char *dst);
108 
109 #include <net/netmap/netmap_mbq.h>
110 
111 extern NMG_LOCK_T	netmap_global_lock;
112 
113 /*
114  * private, kernel view of a ring. Keeps track of the status of
115  * a ring across system calls.
116  *
117  *	nr_hwcur	index of the next buffer to refill.
118  *			It corresponds to ring->cur - ring->reserved
119  *
120  *	nr_hwavail	the number of slots "owned" by userspace.
121  *			nr_hwavail =:= ring->avail + ring->reserved
122  *
123  * The indexes in the NIC and netmap rings are offset by nkr_hwofs slots.
124  * This is so that, on a reset, buffers owned by userspace are not
125  * modified by the kernel. In particular:
126  * RX rings: the next empty buffer (hwcur + hwavail + hwofs) coincides with
127  * 	the next empty buffer as known by the hardware (next_to_check or so).
128  * TX rings: hwcur + hwofs coincides with next_to_send
129  *
130  * Clients cannot issue concurrent syscall on a ring. The system
131  * detects this and reports an error using two flags,
132  * NKR_WBUSY and NKR_RBUSY
133  * For received packets, slot->flags is set to nkr_slot_flags
134  * so we can provide a proper initial value (e.g. set NS_FORWARD
135  * when operating in 'transparent' mode).
136  *
137  * The following fields are used to implement lock-free copy of packets
138  * from input to output ports in VALE switch:
139  *	nkr_hwlease	buffer after the last one being copied.
140  *			A writer in nm_bdg_flush reserves N buffers
141  *			from nr_hwlease, advances it, then does the
142  *			copy outside the lock.
143  *			In RX rings (used for VALE ports),
144  *			nkr_hwcur + nkr_hwavail <= nkr_hwlease < nkr_hwcur+N-1
145  *			In TX rings (used for NIC or host stack ports)
146  *			nkr_hwcur <= nkr_hwlease < nkr_hwcur+ nkr_hwavail
147  *	nkr_leases	array of nkr_num_slots where writers can report
148  *			completion of their block. NR_NOSLOT (~0) indicates
149  *			that the writer has not finished yet
150  *	nkr_lease_idx	index of next free slot in nr_leases, to be assigned
151  *
152  * The kring is manipulated by txsync/rxsync and generic netmap function.
153  * q_lock is used to arbitrate access to the kring from within the netmap
154  * code, and this and other protections guarantee that there is never
155  * more than 1 concurrent call to txsync or rxsync. So we are free
156  * to manipulate the kring from within txsync/rxsync without any extra
157  * locks.
158  */
159 struct netmap_kring {
160 	struct netmap_ring *ring;
161 	uint32_t nr_hwcur;
162 	uint32_t nr_hwavail;
163 	uint32_t nr_kflags;	/* private driver flags */
164 	int32_t nr_hwreserved;
165 #define NKR_PENDINTR	0x1	// Pending interrupt.
166 	uint32_t nkr_num_slots;
167 	int32_t	nkr_hwofs;	/* offset between NIC and netmap ring */
168 
169 	uint16_t	nkr_slot_flags;	/* initial value for flags */
170 	struct netmap_adapter *na;
171 	struct nm_bdg_fwd *nkr_ft;
172 	uint32_t *nkr_leases;
173 #define NR_NOSLOT	((uint32_t)~0)
174 	uint32_t nkr_hwlease;
175 	uint32_t nkr_lease_idx;
176 
177 	NM_SELINFO_T si;	/* poll/select wait queue */
178 	NM_LOCK_T q_lock;	/* protects kring and ring. */
179 	NM_ATOMIC_T nr_busy;	/* prevent concurrent syscalls */
180 
181 	volatile int nkr_stopped;
182 
183 	/* support for adapters without native netmap support.
184 	 * On tx rings we preallocate an array of tx buffers
185 	 * (same size as the netmap ring), on rx rings we
186 	 * store incoming packets in a queue.
187 	 * XXX who writes to the rx queue ?
188 	 */
189 	struct mbuf **tx_pool;
190 	u_int nr_ntc;                   /* Emulation of a next-to-clean RX ring pointer. */
191 	struct mbq rx_queue;            /* A queue for intercepted rx mbufs. */
192 
193 } __attribute__((__aligned__(64)));
194 
195 
196 /* return the next index, with wraparound */
197 static inline uint32_t
198 nm_next(uint32_t i, uint32_t lim)
199 {
200 	return unlikely (i == lim) ? 0 : i + 1;
201 }
202 
203 /*
204  *
205  * Here is the layout for the Rx and Tx rings.
206 
207        RxRING                            TxRING
208 
209       +-----------------+            +-----------------+
210       |                 |            |                 |
211       |XXX free slot XXX|            |XXX free slot XXX|
212       +-----------------+            +-----------------+
213       |                 |<-hwcur     |                 |<-hwcur
214       | reserved    h   |            | (ready          |
215       +-----------  w  -+            |  to be          |
216  cur->|             a   |            |  sent)      h   |
217       |             v   |            +----------   w   |
218       |             a   |       cur->| (being      a   |
219       |             i   |            |  prepared)  v   |
220       | avail       l   |            |             a   |
221       +-----------------+            +  a  ------  i   +
222       |                 | ...        |  v          l   |<-hwlease
223       | (being          | ...        |  a              | ...
224       |  prepared)      | ...        |  i              | ...
225       +-----------------+ ...        |  l              | ...
226       |                 |<-hwlease   +-----------------+
227       |                 |            |                 |
228       |                 |            |                 |
229       |                 |            |                 |
230       |                 |            |                 |
231       +-----------------+            +-----------------+
232 
233  * The cur/avail (user view) and hwcur/hwavail (kernel view)
234  * are used in the normal operation of the card.
235  *
236  * When a ring is the output of a switch port (Rx ring for
237  * a VALE port, Tx ring for the host stack or NIC), slots
238  * are reserved in blocks through 'hwlease' which points
239  * to the next unused slot.
240  * On an Rx ring, hwlease is always after hwavail,
241  * and completions cause avail to advance.
242  * On a Tx ring, hwlease is always between cur and hwavail,
243  * and completions cause cur to advance.
244  *
245  * nm_kr_space() returns the maximum number of slots that
246  * can be assigned.
247  * nm_kr_lease() reserves the required number of buffers,
248  *    advances nkr_hwlease and also returns an entry in
249  *    a circular array where completions should be reported.
250  */
251 
252 
253 
254 
255 enum txrx { NR_RX = 0, NR_TX = 1 };
256 
257 /*
258  * The "struct netmap_adapter" extends the "struct adapter"
259  * (or equivalent) device descriptor.
260  * It contains all base fields needed to support netmap operation.
261  * There are in fact different types of netmap adapters
262  * (native, generic, VALE switch...) so a netmap_adapter is
263  * just the first field in the derived type.
264  */
265 struct netmap_adapter {
266 	/*
267 	 * On linux we do not have a good way to tell if an interface
268 	 * is netmap-capable. So we use the following trick:
269 	 * NA(ifp) points here, and the first entry (which hopefully
270 	 * always exists and is at least 32 bits) contains a magic
271 	 * value which we can use to detect that the interface is good.
272 	 */
273 	uint32_t magic;
274 	uint32_t na_flags;	/* future place for IFCAP_NETMAP */
275 #define NAF_SKIP_INTR	1	/* use the regular interrupt handler.
276 				 * useful during initialization
277 				 */
278 #define NAF_SW_ONLY	2	/* forward packets only to sw adapter */
279 #define NAF_BDG_MAYSLEEP 4	/* the bridge is allowed to sleep when
280 				 * forwarding packets coming from this
281 				 * interface
282 				 */
283 #define NAF_MEM_OWNER	8	/* the adapter is responsible for the
284 				 * deallocation of the memory allocator
285 				 */
286 #define NAF_NATIVE_ON   16      /* the adapter is native and the attached
287 				 * interface is in netmap mode
288 				 */
289 	int active_fds; /* number of user-space descriptors using this
290 			 interface, which is equal to the number of
291 			 struct netmap_if objs in the mapped region. */
292 
293 	u_int num_rx_rings; /* number of adapter receive rings */
294 	u_int num_tx_rings; /* number of adapter transmit rings */
295 
296 	u_int num_tx_desc; /* number of descriptor in each queue */
297 	u_int num_rx_desc;
298 
299 	/* tx_rings and rx_rings are private but allocated
300 	 * as a contiguous chunk of memory. Each array has
301 	 * N+1 entries, for the adapter queues and for the host queue.
302 	 */
303 	struct netmap_kring *tx_rings; /* array of TX rings. */
304 	struct netmap_kring *rx_rings; /* array of RX rings. */
305 	void *tailroom;		       /* space below the rings array */
306 				       /* (used for leases) */
307 
308 
309 	NM_SELINFO_T tx_si, rx_si;	/* global wait queues */
310 
311 	/* copy of if_qflush and if_transmit pointers, to intercept
312 	 * packets from the network stack when netmap is active.
313 	 */
314 	int     (*if_transmit)(struct ifnet *, struct mbuf *);
315 
316 	/* references to the ifnet and device routines, used by
317 	 * the generic netmap functions.
318 	 */
319 	struct ifnet *ifp; /* adapter is ifp->if_softc */
320 
321 	/* private cleanup */
322 	void (*nm_dtor)(struct netmap_adapter *);
323 
324 	int (*nm_register)(struct netmap_adapter *, int onoff);
325 
326 	int (*nm_txsync)(struct netmap_adapter *, u_int ring, int flags);
327 	int (*nm_rxsync)(struct netmap_adapter *, u_int ring, int flags);
328 #define NAF_FORCE_READ    1
329 #define NAF_FORCE_RECLAIM 2
330 	/* return configuration information */
331 	int (*nm_config)(struct netmap_adapter *,
332 		u_int *txr, u_int *txd, u_int *rxr, u_int *rxd);
333 	int (*nm_krings_create)(struct netmap_adapter *);
334 	void (*nm_krings_delete)(struct netmap_adapter *);
335 	int (*nm_notify)(struct netmap_adapter *,
336 		u_int ring, enum txrx, int flags);
337 #define NAF_GLOBAL_NOTIFY 4
338 #define NAF_DISABLE_NOTIFY 8
339 
340 	/* standard refcount to control the lifetime of the adapter
341 	 * (it should be equal to the lifetime of the corresponding ifp)
342 	 */
343 	int na_refcount;
344 
345 	/* memory allocator (opaque)
346 	 * We also cache a pointer to the lut_entry for translating
347 	 * buffer addresses, and the total number of buffers.
348 	 */
349  	struct netmap_mem_d *nm_mem;
350 	struct lut_entry *na_lut;
351 	uint32_t na_lut_objtotal;	/* max buffer index */
352 
353 	/* used internally. If non-null, the interface cannot be bound
354 	 * from userspace
355 	 */
356 	void *na_private;
357 };
358 
359 /*
360  * If the NIC is owned by the kernel
361  * (i.e., bridge), neither another bridge nor user can use it;
362  * if the NIC is owned by a user, only users can share it.
363  * Evaluation must be done under NMG_LOCK().
364  */
365 #define NETMAP_OWNED_BY_KERN(na)	(na->na_private)
366 #define NETMAP_OWNED_BY_ANY(na) \
367 	(NETMAP_OWNED_BY_KERN(na) || (na->active_fds > 0))
368 
369 
370 /*
371  * derived netmap adapters for various types of ports
372  */
373 struct netmap_vp_adapter {	/* VALE software port */
374 	struct netmap_adapter up;
375 
376 	/*
377 	 * Bridge support:
378 	 *
379 	 * bdg_port is the port number used in the bridge;
380 	 * na_bdg points to the bridge this NA is attached to.
381 	 */
382 	int bdg_port;
383 	struct nm_bridge *na_bdg;
384 	int retry;
385 };
386 
387 struct netmap_hw_adapter {	/* physical device */
388 	struct netmap_adapter up;
389 
390 	struct net_device_ops nm_ndo;	// XXX linux only
391 };
392 
393 struct netmap_generic_adapter {	/* non-native device */
394 	struct netmap_hw_adapter up;
395 
396 	/* Pointer to a previously used netmap adapter. */
397 	struct netmap_adapter *prev;
398 
399 	/* generic netmap adapters support:
400 	 * a net_device_ops struct overrides ndo_select_queue(),
401 	 * save_if_input saves the if_input hook (FreeBSD),
402 	 * mit_timer and mit_pending implement rx interrupt mitigation,
403 	 */
404 	struct net_device_ops generic_ndo;
405 	void (*save_if_input)(struct ifnet *, struct mbuf *,
406 	    const struct pktinfo *, int);
407 
408 	struct hrtimer mit_timer;
409 	int mit_pending;
410 };
411 
412 #ifdef WITH_VALE
413 
414 /* bridge wrapper for non VALE ports. It is used to connect real devices to the bridge.
415  *
416  * The real device must already have its own netmap adapter (hwna).  The
417  * bridge wrapper and the hwna adapter share the same set of netmap rings and
418  * buffers, but they have two separate sets of krings descriptors, with tx/rx
419  * meanings swapped:
420  *
421  *                                  netmap
422  *           bwrap     krings       rings      krings      hwna
423  *         +------+   +------+     +-----+    +------+   +------+
424  *         |tx_rings->|      |\   /|     |----|      |<-tx_rings|
425  *         |      |   +------+ \ / +-----+    +------+   |      |
426  *         |      |             X                        |      |
427  *         |      |            / \                       |      |
428  *         |      |   +------+/   \+-----+    +------+   |      |
429  *         |rx_rings->|      |     |     |----|      |<-rx_rings|
430  *         |      |   +------+     +-----+    +------+   |      |
431  *         +------+                                      +------+
432  *
433  * - packets coming from the bridge go to the brwap rx rings, which are also the
434  *   hwna tx rings.  The bwrap notify callback will then complete the hwna tx
435  *   (see netmap_bwrap_notify).
436  * - packets coming from the outside go to the hwna rx rings, which are also the
437  *   bwrap tx rings.  The (overwritten) hwna notify method will then complete
438  *   the bridge tx (see netmap_bwrap_intr_notify).
439  *
440  *   The bridge wrapper may optionally connect the hwna 'host' rings to the
441  *   bridge. This is done by using a second port in the bridge and connecting it
442  *   to the 'host' netmap_vp_adapter contained in the netmap_bwrap_adapter.
443  *   The brwap host adapter cross-links the hwna host rings in the same way as shown above.
444  *
445  * - packets coming from the bridge and directed to host stack are handled by the
446  *   bwrap host notify callback (see netmap_bwrap_host_notify)
447  * - packets coming from the host stack are still handled by the overwritten
448  *   hwna notify callback (netmap_bwrap_intr_notify), but are diverted to the
449  *   host adapter depending on the ring number.
450  *
451  */
452 struct netmap_bwrap_adapter {
453 	struct netmap_vp_adapter up;
454 	struct netmap_vp_adapter host;  /* for host rings */
455 	struct netmap_adapter *hwna;	/* the underlying device */
456 
457 	/* backup of the hwna notify callback */
458 	int (*save_notify)(struct netmap_adapter *,
459 			u_int ring, enum txrx, int flags);
460 	/* When we attach a physical interface to the bridge, we
461 	 * allow the controlling process to terminate, so we need
462 	 * a place to store the netmap_priv_d data structure.
463 	 * This is only done when physical interfaces are attached to a bridge.
464 	 */
465 	struct netmap_priv_d *na_kpriv;
466 };
467 
468 
469 /*
470  * Available space in the ring. Only used in VALE code
471  */
472 static inline uint32_t
473 nm_kr_space(struct netmap_kring *k, int is_rx)
474 {
475 	int space;
476 
477 	if (is_rx) {
478 		int busy = k->nkr_hwlease - k->nr_hwcur + k->nr_hwreserved;
479 		if (busy < 0)
480 			busy += k->nkr_num_slots;
481 		space = k->nkr_num_slots - 1 - busy;
482 	} else {
483 		space = k->nr_hwcur + k->nr_hwavail - k->nkr_hwlease;
484 		if (space < 0)
485 			space += k->nkr_num_slots;
486 	}
487 #if 0
488 	// sanity check
489 	if (k->nkr_hwlease >= k->nkr_num_slots ||
490 		k->nr_hwcur >= k->nkr_num_slots ||
491 		k->nr_hwavail >= k->nkr_num_slots ||
492 		busy < 0 ||
493 		busy >= k->nkr_num_slots) {
494 		D("invalid kring, cur %d avail %d lease %d lease_idx %d lim %d",			k->nr_hwcur, k->nr_hwavail, k->nkr_hwlease,
495 			k->nkr_lease_idx, k->nkr_num_slots);
496 	}
497 #endif
498 	return space;
499 }
500 
501 
502 
503 
504 /* make a lease on the kring for N positions. return the
505  * lease index
506  */
507 static inline uint32_t
508 nm_kr_lease(struct netmap_kring *k, u_int n, int is_rx)
509 {
510 	uint32_t lim = k->nkr_num_slots - 1;
511 	uint32_t lease_idx = k->nkr_lease_idx;
512 
513 	k->nkr_leases[lease_idx] = NR_NOSLOT;
514 	k->nkr_lease_idx = nm_next(lease_idx, lim);
515 
516 	if (n > nm_kr_space(k, is_rx)) {
517 		D("invalid request for %d slots", n);
518 		panic("x");
519 	}
520 	/* XXX verify that there are n slots */
521 	k->nkr_hwlease += n;
522 	if (k->nkr_hwlease > lim)
523 		k->nkr_hwlease -= lim + 1;
524 
525 	if (k->nkr_hwlease >= k->nkr_num_slots ||
526 		k->nr_hwcur >= k->nkr_num_slots ||
527 		k->nr_hwavail >= k->nkr_num_slots ||
528 		k->nkr_lease_idx >= k->nkr_num_slots) {
529 		D("invalid kring %s, cur %d avail %d lease %d lease_idx %d lim %d",
530 			k->na->ifp->if_xname,
531 			k->nr_hwcur, k->nr_hwavail, k->nkr_hwlease,
532 			k->nkr_lease_idx, k->nkr_num_slots);
533 	}
534 	return lease_idx;
535 }
536 
537 #endif /* WITH_VALE */
538 
539 /* return update position */
540 static inline uint32_t
541 nm_kr_rxpos(struct netmap_kring *k)
542 {
543 	uint32_t pos = k->nr_hwcur + k->nr_hwavail;
544 	if (pos >= k->nkr_num_slots)
545 		pos -= k->nkr_num_slots;
546 #if 0
547 	if (pos >= k->nkr_num_slots ||
548 		k->nkr_hwlease >= k->nkr_num_slots ||
549 		k->nr_hwcur >= k->nkr_num_slots ||
550 		k->nr_hwavail >= k->nkr_num_slots ||
551 		k->nkr_lease_idx >= k->nkr_num_slots) {
552 		D("invalid kring, cur %d avail %d lease %d lease_idx %d lim %d",			k->nr_hwcur, k->nr_hwavail, k->nkr_hwlease,
553 			k->nkr_lease_idx, k->nkr_num_slots);
554 	}
555 #endif
556 	return pos;
557 }
558 
559 
560 /*
561  * protect against multiple threads using the same ring.
562  * also check that the ring has not been stopped.
563  * We only care for 0 or !=0 as a return code.
564  */
565 #define NM_KR_BUSY	1
566 #define NM_KR_STOPPED	2
567 
568 static __inline void nm_kr_put(struct netmap_kring *kr)
569 {
570 	NM_ATOMIC_CLEAR(&kr->nr_busy);
571 }
572 
573 static __inline int nm_kr_tryget(struct netmap_kring *kr)
574 {
575 	/* check a first time without taking the lock
576 	 * to avoid starvation for nm_kr_get()
577 	 */
578 	if (unlikely(kr->nkr_stopped)) {
579 		ND("ring %p stopped (%d)", kr, kr->nkr_stopped);
580 		return NM_KR_STOPPED;
581 	}
582 	if (unlikely(NM_ATOMIC_TEST_AND_SET(&kr->nr_busy)))
583 		return NM_KR_BUSY;
584 	/* check a second time with lock held */
585 	if (unlikely(kr->nkr_stopped)) {
586 		ND("ring %p stopped (%d)", kr, kr->nkr_stopped);
587 		nm_kr_put(kr);
588 		return NM_KR_STOPPED;
589 	}
590 	return 0;
591 }
592 
593 
594 /*
595  * The following are support routines used by individual drivers to
596  * support netmap operation.
597  *
598  * netmap_attach() initializes a struct netmap_adapter, allocating the
599  * 	struct netmap_ring's and the struct selinfo.
600  *
601  * netmap_detach() frees the memory allocated by netmap_attach().
602  *
603  * netmap_transmit() replaces the if_transmit routine of the interface,
604  *	and is used to intercept packets coming from the stack.
605  *
606  * netmap_load_map/netmap_reload_map are helper routines to set/reset
607  *	the dmamap for a packet buffer
608  *
609  * netmap_reset() is a helper routine to be called in the driver
610  *	when reinitializing a ring.
611  */
612 int netmap_attach(struct netmap_adapter *);
613 int netmap_attach_common(struct netmap_adapter *);
614 void netmap_detach_common(struct netmap_adapter *na);
615 void netmap_detach(struct ifnet *);
616 int netmap_transmit(struct ifnet *, struct mbuf *);
617 struct netmap_slot *netmap_reset(struct netmap_adapter *na,
618 	enum txrx tx, u_int n, u_int new_cur);
619 int netmap_ring_reinit(struct netmap_kring *);
620 
621 
622 /*
623  * Support routines to be used with the VALE switch
624  */
625 int netmap_update_config(struct netmap_adapter *na);
626 int netmap_krings_create(struct netmap_adapter *na, u_int ntx, u_int nrx, u_int tailroom);
627 void netmap_krings_delete(struct netmap_adapter *na);
628 
629 struct netmap_if *
630 netmap_do_regif(struct netmap_priv_d *priv, struct netmap_adapter *na,
631 	uint16_t ringid, int *err);
632 
633 
634 
635 u_int nm_bound_var(u_int *v, u_int dflt, u_int lo, u_int hi, const char *msg);
636 int netmap_get_na(struct nmreq *nmr, struct netmap_adapter **na, int create);
637 int netmap_get_hw_na(struct ifnet *ifp, struct netmap_adapter **na);
638 
639 #ifdef WITH_VALE
640 /*
641  * The following bridge-related interfaces are used by other kernel modules
642  * In the version that only supports unicast or broadcast, the lookup
643  * function can return 0 .. NM_BDG_MAXPORTS-1 for regular ports,
644  * NM_BDG_MAXPORTS for broadcast, NM_BDG_MAXPORTS+1 for unknown.
645  * XXX in practice "unknown" might be handled same as broadcast.
646  */
647 typedef u_int (*bdg_lookup_fn_t)(char *buf, u_int len,
648 		uint8_t *ring_nr, struct netmap_vp_adapter *);
649 u_int netmap_bdg_learning(char *, u_int, uint8_t *,
650 		struct netmap_vp_adapter *);
651 
652 #define	NM_BDG_MAXPORTS		254	/* up to 254 */
653 #define	NM_BDG_BROADCAST	NM_BDG_MAXPORTS
654 #define	NM_BDG_NOPORT		(NM_BDG_MAXPORTS+1)
655 
656 #define	NM_NAME			"vale"	/* prefix for bridge port name */
657 
658 
659 /* these are redefined in case of no VALE support */
660 int netmap_get_bdg_na(struct nmreq *nmr, struct netmap_adapter **na, int create);
661 void netmap_init_bridges(void);
662 int netmap_bdg_ctl(struct nmreq *nmr, bdg_lookup_fn_t func);
663 
664 #else /* !WITH_VALE */
665 #define	netmap_get_bdg_na(_1, _2, _3)	0
666 #define netmap_init_bridges(_1)
667 #define	netmap_bdg_ctl(_1, _2)	EINVAL
668 #endif /* !WITH_VALE */
669 
670 /* Various prototypes */
671 struct dev_kqfilter_args;	/* XXX this shouldn't be here */
672 int netmap_kqfilter(struct dev_kqfilter_args *ap);
673 
674 
675 int netmap_init(void);
676 void netmap_fini(void);
677 int netmap_get_memory(struct netmap_priv_d* p);
678 void netmap_dtor(void *data);
679 int netmap_dtor_locked(struct netmap_priv_d *priv);
680 
681 struct dev_ioctl_args;	/* XXX this shouldn't be here */
682 int netmap_ioctl(struct dev_ioctl_args *ap);
683 
684 /* netmap_adapter creation/destruction */
685 #define NM_IFPNAME(ifp) ((ifp) ? (ifp)->if_xname : "zombie")
686 #define NM_DEBUG_PUTGET 1
687 
688 #ifdef NM_DEBUG_PUTGET
689 
690 #define NM_DBG(f) __##f
691 
692 void __netmap_adapter_get(struct netmap_adapter *na);
693 
694 #define netmap_adapter_get(na) 				\
695 	do {						\
696 		struct netmap_adapter *__na = na;	\
697 		D("getting %p:%s (%d)", __na, NM_IFPNAME(__na->ifp), __na->na_refcount);	\
698 		__netmap_adapter_get(__na);		\
699 	} while (0)
700 
701 int __netmap_adapter_put(struct netmap_adapter *na);
702 
703 #define netmap_adapter_put(na)				\
704 	do {						\
705 		struct netmap_adapter *__na = na;	\
706 		D("putting %p:%s (%d)", __na, NM_IFPNAME(__na->ifp), __na->na_refcount);	\
707 		__netmap_adapter_put(__na);		\
708 	} while (0)
709 
710 #else /* !NM_DEBUG_PUTGET */
711 
712 #define NM_DBG(f) f
713 void netmap_adapter_get(struct netmap_adapter *na);
714 int netmap_adapter_put(struct netmap_adapter *na);
715 
716 #endif /* !NM_DEBUG_PUTGET */
717 
718 
719 
720 extern u_int netmap_buf_size;
721 #define NETMAP_BUF_SIZE	netmap_buf_size	// XXX remove
722 extern int netmap_mitigate;
723 extern int netmap_no_pendintr;
724 extern u_int netmap_total_buffers;
725 extern char *netmap_buffer_base;
726 extern int netmap_verbose;	// XXX debugging
727 enum {                                  /* verbose flags */
728 	NM_VERB_ON = 1,                 /* generic verbose */
729 	NM_VERB_HOST = 0x2,             /* verbose host stack */
730 	NM_VERB_RXSYNC = 0x10,          /* verbose on rxsync/txsync */
731 	NM_VERB_TXSYNC = 0x20,
732 	NM_VERB_RXINTR = 0x100,         /* verbose on rx/tx intr (driver) */
733 	NM_VERB_TXINTR = 0x200,
734 	NM_VERB_NIC_RXSYNC = 0x1000,    /* verbose on rx/tx intr (driver) */
735 	NM_VERB_NIC_TXSYNC = 0x2000,
736 };
737 
738 extern int netmap_txsync_retry;
739 extern int netmap_generic_mit;
740 extern int netmap_generic_ringsize;
741 
742 /*
743  * NA returns a pointer to the struct netmap adapter from the ifp,
744  * WNA is used to write it.
745  */
746 #ifndef WNA
747 #define	WNA(_ifp)	(_ifp)->if_unused7	/* XXX better name ;) */
748 #endif
749 #define	NA(_ifp)	((struct netmap_adapter *)WNA(_ifp))
750 
751 /*
752  * Macros to determine if an interface is netmap capable or netmap enabled.
753  * See the magic field in struct netmap_adapter.
754  */
755 /*
756  * on FreeBSD just use if_capabilities and if_capenable.
757  */
758 #define NETMAP_CAPABLE(ifp)	(NA(ifp) &&		\
759 	(ifp)->if_capabilities & IFCAP_NETMAP )
760 
761 #define	NETMAP_SET_CAPABLE(ifp)				\
762 	(ifp)->if_capabilities |= IFCAP_NETMAP
763 
764 /* Callback invoked by the dma machinery after a successfull dmamap_load */
765 static void netmap_dmamap_cb(__unused void *arg,
766     __unused bus_dma_segment_t * segs, __unused int nseg, __unused int error)
767 {
768 }
769 
770 /* bus_dmamap_load wrapper: call aforementioned function if map != NULL.
771  * XXX can we do it without a callback ?
772  */
773 static inline void
774 netmap_load_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
775 {
776 	if (map)
777 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
778 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
779 }
780 
781 /* update the map when a buffer changes. */
782 static inline void
783 netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
784 {
785 	if (map) {
786 		bus_dmamap_unload(tag, map);
787 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
788 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
789 	}
790 }
791 
792 /*
793  * functions to map NIC to KRING indexes (n2k) and vice versa (k2n)
794  */
795 static inline int
796 netmap_idx_n2k(struct netmap_kring *kr, int idx)
797 {
798 	int n = kr->nkr_num_slots;
799 	idx += kr->nkr_hwofs;
800 	if (idx < 0)
801 		return idx + n;
802 	else if (idx < n)
803 		return idx;
804 	else
805 		return idx - n;
806 }
807 
808 
809 static inline int
810 netmap_idx_k2n(struct netmap_kring *kr, int idx)
811 {
812 	int n = kr->nkr_num_slots;
813 	idx -= kr->nkr_hwofs;
814 	if (idx < 0)
815 		return idx + n;
816 	else if (idx < n)
817 		return idx;
818 	else
819 		return idx - n;
820 }
821 
822 
823 /* Entries of the look-up table. */
824 struct lut_entry {
825 	void *vaddr;		/* virtual address. */
826 	vm_paddr_t paddr;	/* physical address. */
827 };
828 
829 struct netmap_obj_pool;
830 extern struct lut_entry *netmap_buffer_lut;
831 #define NMB_VA(i)	(netmap_buffer_lut[i].vaddr)
832 #define NMB_PA(i)	(netmap_buffer_lut[i].paddr)
833 
834 /*
835  * NMB return the virtual address of a buffer (buffer 0 on bad index)
836  * PNMB also fills the physical address
837  */
838 static inline void *
839 NMB(struct netmap_slot *slot)
840 {
841 	uint32_t i = slot->buf_idx;
842 	return (unlikely(i >= netmap_total_buffers)) ?  NMB_VA(0) : NMB_VA(i);
843 }
844 
845 static inline void *
846 PNMB(struct netmap_slot *slot, uint64_t *pp)
847 {
848 	uint32_t i = slot->buf_idx;
849 	void *ret = (i >= netmap_total_buffers) ? NMB_VA(0) : NMB_VA(i);
850 
851 	*pp = (i >= netmap_total_buffers) ? NMB_PA(0) : NMB_PA(i);
852 	return ret;
853 }
854 
855 /* Generic version of NMB, which uses device-specific memory. */
856 static inline void *
857 BDG_NMB(struct netmap_adapter *na, struct netmap_slot *slot)
858 {
859 	struct lut_entry *lut = na->na_lut;
860 	uint32_t i = slot->buf_idx;
861 	return (unlikely(i >= na->na_lut_objtotal)) ?
862 		lut[0].vaddr : lut[i].vaddr;
863 }
864 
865 /* default functions to handle rx/tx interrupts */
866 int netmap_rx_irq(struct ifnet *, u_int, u_int *);
867 #define netmap_tx_irq(_n, _q) netmap_rx_irq(_n, _q, NULL)
868 int netmap_common_irq(struct ifnet *, u_int, u_int *work_done);
869 
870 
871 void netmap_txsync_to_host(struct netmap_adapter *na);
872 void netmap_disable_all_rings(struct ifnet *);
873 void netmap_enable_all_rings(struct ifnet *);
874 void netmap_disable_ring(struct netmap_kring *kr);
875 
876 
877 /* Structure associated to each thread which registered an interface.
878  *
879  * The first 4 fields of this structure are written by NIOCREGIF and
880  * read by poll() and NIOC?XSYNC.
881  * There is low contention among writers (actually, a correct user program
882  * should have no contention among writers) and among writers and readers,
883  * so we use a single global lock to protect the structure initialization.
884  * Since initialization involves the allocation of memory, we reuse the memory
885  * allocator lock.
886  * Read access to the structure is lock free. Readers must check that
887  * np_nifp is not NULL before using the other fields.
888  * If np_nifp is NULL initialization has not been performed, so they should
889  * return an error to userlevel.
890  *
891  * The ref_done field is used to regulate access to the refcount in the
892  * memory allocator. The refcount must be incremented at most once for
893  * each open("/dev/netmap"). The increment is performed by the first
894  * function that calls netmap_get_memory() (currently called by
895  * mmap(), NIOCGINFO and NIOCREGIF).
896  * If the refcount is incremented, it is then decremented when the
897  * private structure is destroyed.
898  */
899 struct netmap_priv_d {
900 	struct netmap_if * volatile np_nifp;	/* netmap if descriptor. */
901 
902 	struct netmap_adapter	*np_na;
903 	int		        np_ringid;	/* from the ioctl */
904 	u_int		        np_qfirst, np_qlast;	/* range of rings to scan */
905 	uint16_t	        np_txpoll;
906 
907 	struct netmap_mem_d     *np_mref;	/* use with NMG_LOCK held */
908 	/* np_refcount is only used on FreeBSD */
909 	int		        np_refcount;	/* use with NMG_LOCK held */
910 };
911 
912 
913 /*
914  * generic netmap emulation for devices that do not have
915  * native netmap support.
916  * XXX generic_netmap_register() is only exported to implement
917  *	nma_is_generic().
918  */
919 int generic_netmap_register(struct netmap_adapter *na, int enable);
920 int generic_netmap_attach(struct ifnet *ifp);
921 
922 int netmap_catch_rx(struct netmap_adapter *na, int intercept);
923 void generic_rx_handler(struct ifnet *ifp, struct mbuf *m,
924     const struct pktinfo *, int);
925 void netmap_catch_packet_steering(struct netmap_generic_adapter *na, int enable);
926 int generic_xmit_frame(struct ifnet *ifp, struct mbuf *m, void *addr, u_int len, u_int ring_nr);
927 int generic_find_num_desc(struct ifnet *ifp, u_int *tx, u_int *rx);
928 void generic_find_num_queues(struct ifnet *ifp, u_int *txq, u_int *rxq);
929 
930 static __inline int
931 nma_is_generic(struct netmap_adapter *na)
932 {
933 	return na->nm_register == generic_netmap_register;
934 }
935 
936 /*
937  * netmap_mitigation API. This is used by the generic adapter
938  * to reduce the number of interrupt requests/selwakeup
939  * to clients on incoming packets.
940  */
941 void netmap_mitigation_init(struct netmap_generic_adapter *na);
942 void netmap_mitigation_start(struct netmap_generic_adapter *na);
943 void netmap_mitigation_restart(struct netmap_generic_adapter *na);
944 int netmap_mitigation_active(struct netmap_generic_adapter *na);
945 void netmap_mitigation_cleanup(struct netmap_generic_adapter *na);
946 
947 // int generic_timer_handler(struct hrtimer *t);
948 
949 #endif /* _NET_NETMAP_KERN_H_ */
950