xref: /freebsd/sys/dev/netmap/netmap_kern.h (revision 41840d75)
1 /*
2  * Copyright (C) 2011-2013 Matteo Landi, Luigi Rizzo. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *   1. Redistributions of source code must retain the above copyright
8  *      notice, this list of conditions and the following disclaimer.
9  *   2. Redistributions in binary form must reproduce the above copyright
10  *      notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 /*
27  * $FreeBSD$
28  *
29  * The header contains the definitions of constants and function
30  * prototypes used only in kernelspace.
31  */
32 
33 #ifndef _NET_NETMAP_KERN_H_
34 #define _NET_NETMAP_KERN_H_
35 
36 #if defined(__FreeBSD__)
37 
38 #define likely(x)	__builtin_expect(!!(x), 1)
39 #define unlikely(x)	__builtin_expect(!!(x), 0)
40 
41 #define	NM_LOCK_T	struct mtx
42 #define	NM_RWLOCK_T	struct rwlock
43 #define	NM_SELINFO_T	struct selinfo
44 #define	MBUF_LEN(m)	((m)->m_pkthdr.len)
45 #define	NM_SEND_UP(ifp, m)	((ifp)->if_input)(ifp, m)
46 
47 #elif defined (linux)
48 
49 #define	NM_LOCK_T	safe_spinlock_t	// see bsd_glue.h
50 #define	NM_RWLOCK_T	safe_spinlock_t	// see bsd_glue.h
51 #define	NM_SELINFO_T	wait_queue_head_t
52 #define	MBUF_LEN(m)	((m)->len)
53 #define	NM_SEND_UP(ifp, m)	netif_rx(m)
54 
55 #ifndef DEV_NETMAP
56 #define DEV_NETMAP
57 #endif
58 
59 /*
60  * IFCAP_NETMAP goes into net_device's priv_flags (if_capenable).
61  * This was 16 bits up to linux 2.6.36, so we need a 16 bit value on older
62  * platforms and tolerate the clash with IFF_DYNAMIC and IFF_BRIDGE_PORT.
63  * For the 32-bit value, 0x100000 has no clashes until at least 3.5.1
64  */
65 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,37)
66 #define IFCAP_NETMAP	0x8000
67 #else
68 #define IFCAP_NETMAP	0x200000
69 #endif
70 
71 #elif defined (__APPLE__)
72 
73 #warning apple support is incomplete.
74 #define likely(x)	__builtin_expect(!!(x), 1)
75 #define unlikely(x)	__builtin_expect(!!(x), 0)
76 #define	NM_LOCK_T	IOLock *
77 #define	NM_SELINFO_T	struct selinfo
78 #define	MBUF_LEN(m)	((m)->m_pkthdr.len)
79 #define	NM_SEND_UP(ifp, m)	((ifp)->if_input)(ifp, m)
80 
81 #else
82 
83 #error unsupported platform
84 
85 #endif /* end - platform-specific code */
86 
87 #define ND(format, ...)
88 #define D(format, ...)						\
89 	do {							\
90 		struct timeval __xxts;				\
91 		microtime(&__xxts);				\
92 		printf("%03d.%06d %s [%d] " format "\n",	\
93 		(int)__xxts.tv_sec % 1000, (int)__xxts.tv_usec,	\
94 		__FUNCTION__, __LINE__, ##__VA_ARGS__);		\
95 	} while (0)
96 
97 /* rate limited, lps indicates how many per second */
98 #define RD(lps, format, ...)					\
99 	do {							\
100 		static int t0, __cnt;				\
101 		if (t0 != time_second) {			\
102 			t0 = time_second;			\
103 			__cnt = 0;				\
104 		}						\
105 		if (__cnt++ < lps)				\
106 			D(format, ##__VA_ARGS__);		\
107 	} while (0)
108 
109 struct netmap_adapter;
110 struct nm_bdg_fwd;
111 struct nm_bridge;
112 struct netmap_priv_d;
113 
114 /*
115  * private, kernel view of a ring. Keeps track of the status of
116  * a ring across system calls.
117  *
118  *	nr_hwcur	index of the next buffer to refill.
119  *			It corresponds to ring->cur - ring->reserved
120  *
121  *	nr_hwavail	the number of slots "owned" by userspace.
122  *			nr_hwavail =:= ring->avail + ring->reserved
123  *
124  * The indexes in the NIC and netmap rings are offset by nkr_hwofs slots.
125  * This is so that, on a reset, buffers owned by userspace are not
126  * modified by the kernel. In particular:
127  * RX rings: the next empty buffer (hwcur + hwavail + hwofs) coincides with
128  * 	the next empty buffer as known by the hardware (next_to_check or so).
129  * TX rings: hwcur + hwofs coincides with next_to_send
130  *
131  * For received packets, slot->flags is set to nkr_slot_flags
132  * so we can provide a proper initial value (e.g. set NS_FORWARD
133  * when operating in 'transparent' mode).
134  */
135 struct netmap_kring {
136 	struct netmap_ring *ring;
137 	u_int nr_hwcur;
138 	int nr_hwavail;
139 	u_int nr_kflags;	/* private driver flags */
140 #define NKR_PENDINTR	0x1	// Pending interrupt.
141 	u_int nkr_num_slots;
142 
143 	uint16_t	nkr_slot_flags;	/* initial value for flags */
144 	int	nkr_hwofs;	/* offset between NIC and netmap ring */
145 	struct netmap_adapter *na;
146 	struct nm_bdg_fwd *nkr_ft;
147 	NM_SELINFO_T si;	/* poll/select wait queue */
148 	NM_LOCK_T q_lock;	/* used if no device lock available */
149 } __attribute__((__aligned__(64)));
150 
151 /*
152  * This struct extends the 'struct adapter' (or
153  * equivalent) device descriptor. It contains all fields needed to
154  * support netmap operation.
155  */
156 struct netmap_adapter {
157 	/*
158 	 * On linux we do not have a good way to tell if an interface
159 	 * is netmap-capable. So we use the following trick:
160 	 * NA(ifp) points here, and the first entry (which hopefully
161 	 * always exists and is at least 32 bits) contains a magic
162 	 * value which we can use to detect that the interface is good.
163 	 */
164 	uint32_t magic;
165 	uint32_t na_flags;	/* future place for IFCAP_NETMAP */
166 #define NAF_SKIP_INTR	1	/* use the regular interrupt handler.
167 				 * useful during initialization
168 				 */
169 #define NAF_SW_ONLY	2	/* forward packets only to sw adapter */
170 	int refcount; /* number of user-space descriptors using this
171 			 interface, which is equal to the number of
172 			 struct netmap_if objs in the mapped region. */
173 	/*
174 	 * The selwakeup in the interrupt thread can use per-ring
175 	 * and/or global wait queues. We track how many clients
176 	 * of each type we have so we can optimize the drivers,
177 	 * and especially avoid huge contention on the locks.
178 	 */
179 	int na_single;	/* threads attached to a single hw queue */
180 	int na_multi;	/* threads attached to multiple hw queues */
181 
182 	int separate_locks; /* set if the interface suports different
183 			       locks for rx, tx and core. */
184 
185 	u_int num_rx_rings; /* number of adapter receive rings */
186 	u_int num_tx_rings; /* number of adapter transmit rings */
187 
188 	u_int num_tx_desc; /* number of descriptor in each queue */
189 	u_int num_rx_desc;
190 
191 	/* tx_rings and rx_rings are private but allocated
192 	 * as a contiguous chunk of memory. Each array has
193 	 * N+1 entries, for the adapter queues and for the host queue.
194 	 */
195 	struct netmap_kring *tx_rings; /* array of TX rings. */
196 	struct netmap_kring *rx_rings; /* array of RX rings. */
197 
198 	NM_SELINFO_T tx_si, rx_si;	/* global wait queues */
199 
200 	/* copy of if_qflush and if_transmit pointers, to intercept
201 	 * packets from the network stack when netmap is active.
202 	 */
203 	int     (*if_transmit)(struct ifnet *, struct mbuf *);
204 
205 	/* references to the ifnet and device routines, used by
206 	 * the generic netmap functions.
207 	 */
208 	struct ifnet *ifp; /* adapter is ifp->if_softc */
209 
210 	NM_LOCK_T core_lock;	/* used if no device lock available */
211 
212 	int (*nm_register)(struct ifnet *, int onoff);
213 	void (*nm_lock)(struct ifnet *, int what, u_int ringid);
214 	int (*nm_txsync)(struct ifnet *, u_int ring, int lock);
215 	int (*nm_rxsync)(struct ifnet *, u_int ring, int lock);
216 	/* return configuration information */
217 	int (*nm_config)(struct ifnet *, u_int *txr, u_int *txd,
218 					u_int *rxr, u_int *rxd);
219 
220 	/*
221 	 * Bridge support:
222 	 *
223 	 * bdg_port is the port number used in the bridge;
224 	 * na_bdg_refcount is a refcount used for bridge ports,
225 	 *	when it goes to 0 we can detach+free this port
226 	 *	(a bridge port is always attached if it exists;
227 	 *	it is not always registered)
228 	 * na_bdg points to the bridge this NA is attached to.
229 	 */
230 	int bdg_port;
231 	int na_bdg_refcount;
232 	struct nm_bridge *na_bdg;
233 	/* When we attach a physical interface to the bridge, we
234 	 * allow the controlling process to terminate, so we need
235 	 * a place to store the netmap_priv_d data structure.
236 	 * This is only done when physical interfaces are attached to a bridge.
237 	 */
238 	struct netmap_priv_d *na_kpriv;
239 #ifdef linux
240 	struct net_device_ops nm_ndo;
241 #endif /* linux */
242 };
243 
244 /*
245  * The combination of "enable" (ifp->if_capenable & IFCAP_NETMAP)
246  * and refcount gives the status of the interface, namely:
247  *
248  *	enable	refcount	Status
249  *
250  *	FALSE	0		normal operation
251  *	FALSE	!= 0		-- (impossible)
252  *	TRUE	1		netmap mode
253  *	TRUE	0		being deleted.
254  */
255 
256 #define NETMAP_DELETING(_na)  (  ((_na)->refcount == 0) &&	\
257 	( (_na)->ifp->if_capenable & IFCAP_NETMAP) )
258 
259 /*
260  * parameters for (*nm_lock)(adapter, what, index)
261  */
262 enum {
263 	NETMAP_NO_LOCK = 0,
264 	NETMAP_CORE_LOCK, NETMAP_CORE_UNLOCK,
265 	NETMAP_TX_LOCK, NETMAP_TX_UNLOCK,
266 	NETMAP_RX_LOCK, NETMAP_RX_UNLOCK,
267 #ifdef __FreeBSD__
268 #define	NETMAP_REG_LOCK		NETMAP_CORE_LOCK
269 #define	NETMAP_REG_UNLOCK	NETMAP_CORE_UNLOCK
270 #else
271 	NETMAP_REG_LOCK, NETMAP_REG_UNLOCK
272 #endif
273 };
274 
275 /* How to handle locking support in netmap_rx_irq/netmap_tx_irq */
276 #define	NETMAP_LOCKED_ENTER	0x10000000	/* already locked on enter */
277 #define	NETMAP_LOCKED_EXIT	0x20000000	/* keep locked on exit */
278 
279 /*
280  * The following are support routines used by individual drivers to
281  * support netmap operation.
282  *
283  * netmap_attach() initializes a struct netmap_adapter, allocating the
284  * 	struct netmap_ring's and the struct selinfo.
285  *
286  * netmap_detach() frees the memory allocated by netmap_attach().
287  *
288  * netmap_start() replaces the if_transmit routine of the interface,
289  *	and is used to intercept packets coming from the stack.
290  *
291  * netmap_load_map/netmap_reload_map are helper routines to set/reset
292  *	the dmamap for a packet buffer
293  *
294  * netmap_reset() is a helper routine to be called in the driver
295  *	when reinitializing a ring.
296  */
297 int netmap_attach(struct netmap_adapter *, int);
298 void netmap_detach(struct ifnet *);
299 int netmap_start(struct ifnet *, struct mbuf *);
300 enum txrx { NR_RX = 0, NR_TX = 1 };
301 struct netmap_slot *netmap_reset(struct netmap_adapter *na,
302 	enum txrx tx, int n, u_int new_cur);
303 int netmap_ring_reinit(struct netmap_kring *);
304 
305 /*
306  * The following bridge-related interfaces are used by other kernel modules
307  * In the version that only supports unicast or broadcast, the lookup
308  * function can return 0 .. NM_BDG_MAXPORTS-1 for regular ports,
309  * NM_BDG_MAXPORTS for broadcast, NM_BDG_MAXPORTS+1 for unknown.
310  * XXX in practice "unknown" might be handled same as broadcast.
311  */
312 typedef u_int (*bdg_lookup_fn_t)(char *buf, u_int len, uint8_t *ring_nr,
313 		struct netmap_adapter *);
314 int netmap_bdg_ctl(struct nmreq *nmr, bdg_lookup_fn_t func);
315 u_int netmap_bdg_learning(char *, u_int, uint8_t *, struct netmap_adapter *);
316 #define	NM_NAME			"vale"	/* prefix for the bridge port name */
317 #define	NM_BDG_MAXPORTS		254	/* up to 32 for bitmap, 254 ok otherwise */
318 #define	NM_BDG_BROADCAST	NM_BDG_MAXPORTS
319 #define	NM_BDG_NOPORT		(NM_BDG_MAXPORTS+1)
320 
321 extern u_int netmap_buf_size;
322 #define NETMAP_BUF_SIZE	netmap_buf_size	// XXX remove
323 extern int netmap_mitigate;
324 extern int netmap_no_pendintr;
325 extern u_int netmap_total_buffers;
326 extern char *netmap_buffer_base;
327 extern int netmap_verbose;	// XXX debugging
328 enum {                                  /* verbose flags */
329 	NM_VERB_ON = 1,                 /* generic verbose */
330 	NM_VERB_HOST = 0x2,             /* verbose host stack */
331 	NM_VERB_RXSYNC = 0x10,          /* verbose on rxsync/txsync */
332 	NM_VERB_TXSYNC = 0x20,
333 	NM_VERB_RXINTR = 0x100,         /* verbose on rx/tx intr (driver) */
334 	NM_VERB_TXINTR = 0x200,
335 	NM_VERB_NIC_RXSYNC = 0x1000,    /* verbose on rx/tx intr (driver) */
336 	NM_VERB_NIC_TXSYNC = 0x2000,
337 };
338 
339 /*
340  * NA returns a pointer to the struct netmap adapter from the ifp,
341  * WNA is used to write it.
342  * SWNA() is used for the "host stack" endpoint associated
343  *	to an interface. It is allocated together with the main NA(),
344  *	as an array of two objects.
345  */
346 #ifndef WNA
347 #define	WNA(_ifp)	(_ifp)->if_pspare[0]
348 #endif
349 #define	NA(_ifp)	((struct netmap_adapter *)WNA(_ifp))
350 #define	SWNA(_ifp)	(NA(_ifp) + 1)
351 
352 /*
353  * Macros to determine if an interface is netmap capable or netmap enabled.
354  * See the magic field in struct netmap_adapter.
355  */
356 #ifdef __FreeBSD__
357 /*
358  * on FreeBSD just use if_capabilities and if_capenable.
359  */
360 #define NETMAP_CAPABLE(ifp)	(NA(ifp) &&		\
361 	(ifp)->if_capabilities & IFCAP_NETMAP )
362 
363 #define	NETMAP_SET_CAPABLE(ifp)				\
364 	(ifp)->if_capabilities |= IFCAP_NETMAP
365 
366 #else	/* linux */
367 
368 /*
369  * on linux:
370  * we check if NA(ifp) is set and its first element has a related
371  * magic value. The capenable is within the struct netmap_adapter.
372  */
373 #define	NETMAP_MAGIC	0x52697a7a
374 
375 #define NETMAP_CAPABLE(ifp)	(NA(ifp) &&		\
376 	((uint32_t)(uintptr_t)NA(ifp) ^ NA(ifp)->magic) == NETMAP_MAGIC )
377 
378 #define	NETMAP_SET_CAPABLE(ifp)				\
379 	NA(ifp)->magic = ((uint32_t)(uintptr_t)NA(ifp)) ^ NETMAP_MAGIC
380 
381 #endif	/* linux */
382 
383 #ifdef __FreeBSD__
384 /* Callback invoked by the dma machinery after a successfull dmamap_load */
385 static void netmap_dmamap_cb(__unused void *arg,
386     __unused bus_dma_segment_t * segs, __unused int nseg, __unused int error)
387 {
388 }
389 
390 /* bus_dmamap_load wrapper: call aforementioned function if map != NULL.
391  * XXX can we do it without a callback ?
392  */
393 static inline void
394 netmap_load_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
395 {
396 	if (map)
397 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
398 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
399 }
400 
401 /* update the map when a buffer changes. */
402 static inline void
403 netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
404 {
405 	if (map) {
406 		bus_dmamap_unload(tag, map);
407 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
408 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
409 	}
410 }
411 #else /* linux */
412 
413 /*
414  * XXX How do we redefine these functions:
415  *
416  * on linux we need
417  *	dma_map_single(&pdev->dev, virt_addr, len, direction)
418  *	dma_unmap_single(&adapter->pdev->dev, phys_addr, len, direction
419  * The len can be implicit (on netmap it is NETMAP_BUF_SIZE)
420  * unfortunately the direction is not, so we need to change
421  * something to have a cross API
422  */
423 #define netmap_load_map(_t, _m, _b)
424 #define netmap_reload_map(_t, _m, _b)
425 #if 0
426 	struct e1000_buffer *buffer_info =  &tx_ring->buffer_info[l];
427 	/* set time_stamp *before* dma to help avoid a possible race */
428 	buffer_info->time_stamp = jiffies;
429 	buffer_info->mapped_as_page = false;
430 	buffer_info->length = len;
431 	//buffer_info->next_to_watch = l;
432 	/* reload dma map */
433 	dma_unmap_single(&adapter->pdev->dev, buffer_info->dma,
434 			NETMAP_BUF_SIZE, DMA_TO_DEVICE);
435 	buffer_info->dma = dma_map_single(&adapter->pdev->dev,
436 			addr, NETMAP_BUF_SIZE, DMA_TO_DEVICE);
437 
438 	if (dma_mapping_error(&adapter->pdev->dev, buffer_info->dma)) {
439 		D("dma mapping error");
440 		/* goto dma_error; See e1000_put_txbuf() */
441 		/* XXX reset */
442 	}
443 	tx_desc->buffer_addr = htole64(buffer_info->dma); //XXX
444 
445 #endif
446 
447 /*
448  * The bus_dmamap_sync() can be one of wmb() or rmb() depending on direction.
449  */
450 #define bus_dmamap_sync(_a, _b, _c)
451 
452 #endif /* linux */
453 
454 /*
455  * functions to map NIC to KRING indexes (n2k) and vice versa (k2n)
456  */
457 static inline int
458 netmap_idx_n2k(struct netmap_kring *kr, int idx)
459 {
460 	int n = kr->nkr_num_slots;
461 	idx += kr->nkr_hwofs;
462 	if (idx < 0)
463 		return idx + n;
464 	else if (idx < n)
465 		return idx;
466 	else
467 		return idx - n;
468 }
469 
470 
471 static inline int
472 netmap_idx_k2n(struct netmap_kring *kr, int idx)
473 {
474 	int n = kr->nkr_num_slots;
475 	idx -= kr->nkr_hwofs;
476 	if (idx < 0)
477 		return idx + n;
478 	else if (idx < n)
479 		return idx;
480 	else
481 		return idx - n;
482 }
483 
484 
485 /* Entries of the look-up table. */
486 struct lut_entry {
487 	void *vaddr;		/* virtual address. */
488 	vm_paddr_t paddr;	/* physical address. */
489 };
490 
491 struct netmap_obj_pool;
492 extern struct lut_entry *netmap_buffer_lut;
493 #define NMB_VA(i)	(netmap_buffer_lut[i].vaddr)
494 #define NMB_PA(i)	(netmap_buffer_lut[i].paddr)
495 
496 /*
497  * NMB return the virtual address of a buffer (buffer 0 on bad index)
498  * PNMB also fills the physical address
499  */
500 static inline void *
501 NMB(struct netmap_slot *slot)
502 {
503 	uint32_t i = slot->buf_idx;
504 	return (unlikely(i >= netmap_total_buffers)) ?  NMB_VA(0) : NMB_VA(i);
505 }
506 
507 static inline void *
508 PNMB(struct netmap_slot *slot, uint64_t *pp)
509 {
510 	uint32_t i = slot->buf_idx;
511 	void *ret = (i >= netmap_total_buffers) ? NMB_VA(0) : NMB_VA(i);
512 
513 	*pp = (i >= netmap_total_buffers) ? NMB_PA(0) : NMB_PA(i);
514 	return ret;
515 }
516 
517 /* default functions to handle rx/tx interrupts */
518 int netmap_rx_irq(struct ifnet *, int, int *);
519 #define netmap_tx_irq(_n, _q) netmap_rx_irq(_n, _q, NULL)
520 
521 #endif /* _NET_NETMAP_KERN_H_ */
522