xref: /freebsd/sys/dev/netmap/netmap_kern.h (revision 850e744187a6784353d7628d2d5a119dcb834f75)
1 /*
2  * Copyright (C) 2011-2012 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  * $Id: netmap_kern.h 11829 2012-09-26 04:06:34Z 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 NETMAP_MEM2    // use the new memory allocator
38 
39 #if defined(__FreeBSD__)
40 #define likely(x)	__builtin_expect(!!(x), 1)
41 #define unlikely(x)	__builtin_expect(!!(x), 0)
42 
43 #define	NM_LOCK_T	struct mtx
44 #define	NM_SELINFO_T	struct selinfo
45 #define	MBUF_LEN(m)	((m)->m_pkthdr.len)
46 #define	NM_SEND_UP(ifp, m)	((ifp)->if_input)(ifp, m)
47 #elif defined (linux)
48 #define	NM_LOCK_T	spinlock_t
49 #define	NM_SELINFO_T	wait_queue_head_t
50 #define	MBUF_LEN(m)	((m)->len)
51 #define	NM_SEND_UP(ifp, m)	netif_rx(m)
52 
53 #ifndef DEV_NETMAP
54 #define DEV_NETMAP
55 #endif
56 
57 /*
58  * IFCAP_NETMAP goes into net_device's priv_flags (if_capenable).
59  * This was 16 bits up to linux 2.6.36, so we need a 16 bit value on older
60  * platforms and tolerate the clash with IFF_DYNAMIC and IFF_BRIDGE_PORT.
61  * For the 32-bit value, 0x100000 has no clashes until at least 3.5.1
62  */
63 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,37)
64 #define IFCAP_NETMAP	0x8000
65 #else
66 #define IFCAP_NETMAP	0x100000
67 #endif
68 
69 #elif defined (__APPLE__)
70 #warning apple support is incomplete.
71 #define likely(x)	__builtin_expect(!!(x), 1)
72 #define unlikely(x)	__builtin_expect(!!(x), 0)
73 #define	NM_LOCK_T	IOLock *
74 #define	NM_SELINFO_T	struct selinfo
75 #define	MBUF_LEN(m)	((m)->m_pkthdr.len)
76 #define	NM_SEND_UP(ifp, m)	((ifp)->if_input)(ifp, m)
77 
78 #else
79 #error unsupported platform
80 #endif
81 
82 #define ND(format, ...)
83 #define D(format, ...)						\
84 	do {							\
85 		struct timeval __xxts;				\
86 		microtime(&__xxts);				\
87 		printf("%03d.%06d %s [%d] " format "\n",	\
88 		(int)__xxts.tv_sec % 1000, (int)__xxts.tv_usec,	\
89 		__FUNCTION__, __LINE__, ##__VA_ARGS__);		\
90 	} while (0)
91 
92 /* rate limited, lps indicates how many per second */
93 #define RD(lps, format, ...)					\
94 	do {							\
95 		static int t0, __cnt;				\
96 		if (t0 != time_second) {			\
97 			t0 = time_second;			\
98 			__cnt = 0;				\
99 		}						\
100 		if (__cnt++ < lps)				\
101 			D(format, ##__VA_ARGS__);		\
102 	} while (0)
103 
104 struct netmap_adapter;
105 
106 /*
107  * private, kernel view of a ring. Keeps track of the status of
108  * a ring across system calls.
109  *
110  *	nr_hwcur	index of the next buffer to refill.
111  *			It corresponds to ring->cur - ring->reserved
112  *
113  *	nr_hwavail	the number of slots "owned" by userspace.
114  *			nr_hwavail =:= ring->avail + ring->reserved
115  *
116  * The indexes in the NIC and netmap rings are offset by nkr_hwofs slots.
117  * This is so that, on a reset, buffers owned by userspace are not
118  * modified by the kernel. In particular:
119  * RX rings: the next empty buffer (hwcur + hwavail + hwofs) coincides with
120  * 	the next empty buffer as known by the hardware (next_to_check or so).
121  * TX rings: hwcur + hwofs coincides with next_to_send
122  *
123  * For received packets, slot->flags is set to nkr_slot_flags
124  * so we can provide a proper initial value (e.g. set NS_FORWARD
125  * when operating in 'transparent' mode).
126  */
127 struct netmap_kring {
128 	struct netmap_ring *ring;
129 	u_int nr_hwcur;
130 	int nr_hwavail;
131 	u_int nr_kflags;	/* private driver flags */
132 #define NKR_PENDINTR	0x1	// Pending interrupt.
133 	u_int nkr_num_slots;
134 
135 	uint16_t	nkr_slot_flags;	/* initial value for flags */
136 	int	nkr_hwofs;	/* offset between NIC and netmap ring */
137 	struct netmap_adapter *na;
138 	NM_SELINFO_T si;	/* poll/select wait queue */
139 	NM_LOCK_T q_lock;	/* used if no device lock available */
140 } __attribute__((__aligned__(64)));
141 
142 /*
143  * This struct extends the 'struct adapter' (or
144  * equivalent) device descriptor. It contains all fields needed to
145  * support netmap operation.
146  */
147 struct netmap_adapter {
148 	/*
149 	 * On linux we do not have a good way to tell if an interface
150 	 * is netmap-capable. So we use the following trick:
151 	 * NA(ifp) points here, and the first entry (which hopefully
152 	 * always exists and is at least 32 bits) contains a magic
153 	 * value which we can use to detect that the interface is good.
154 	 */
155 	uint32_t magic;
156 	uint32_t na_flags;	/* future place for IFCAP_NETMAP */
157 #define NAF_SKIP_INTR	1	/* use the regular interrupt handler.
158 				 * useful during initialization
159 				 */
160 	int refcount; /* number of user-space descriptors using this
161 			 interface, which is equal to the number of
162 			 struct netmap_if objs in the mapped region. */
163 	/*
164 	 * The selwakeup in the interrupt thread can use per-ring
165 	 * and/or global wait queues. We track how many clients
166 	 * of each type we have so we can optimize the drivers,
167 	 * and especially avoid huge contention on the locks.
168 	 */
169 	int na_single;	/* threads attached to a single hw queue */
170 	int na_multi;	/* threads attached to multiple hw queues */
171 
172 	int separate_locks; /* set if the interface suports different
173 			       locks for rx, tx and core. */
174 
175 	u_int num_rx_rings; /* number of adapter receive rings */
176 	u_int num_tx_rings; /* number of adapter transmit rings */
177 
178 	u_int num_tx_desc; /* number of descriptor in each queue */
179 	u_int num_rx_desc;
180 
181 	/* tx_rings and rx_rings are private but allocated
182 	 * as a contiguous chunk of memory. Each array has
183 	 * N+1 entries, for the adapter queues and for the host queue.
184 	 */
185 	struct netmap_kring *tx_rings; /* array of TX rings. */
186 	struct netmap_kring *rx_rings; /* array of RX rings. */
187 
188 	NM_SELINFO_T tx_si, rx_si;	/* global wait queues */
189 
190 	/* copy of if_qflush and if_transmit pointers, to intercept
191 	 * packets from the network stack when netmap is active.
192 	 */
193 	int     (*if_transmit)(struct ifnet *, struct mbuf *);
194 
195 	/* references to the ifnet and device routines, used by
196 	 * the generic netmap functions.
197 	 */
198 	struct ifnet *ifp; /* adapter is ifp->if_softc */
199 
200 	NM_LOCK_T core_lock;	/* used if no device lock available */
201 
202 	int (*nm_register)(struct ifnet *, int onoff);
203 	void (*nm_lock)(struct ifnet *, int what, u_int ringid);
204 	int (*nm_txsync)(struct ifnet *, u_int ring, int lock);
205 	int (*nm_rxsync)(struct ifnet *, u_int ring, int lock);
206 
207 	int bdg_port;
208 #ifdef linux
209 	struct net_device_ops nm_ndo;
210 	int if_refcount;	// XXX additions for bridge
211 #endif /* linux */
212 };
213 
214 /*
215  * The combination of "enable" (ifp->if_capenable & IFCAP_NETMAP)
216  * and refcount gives the status of the interface, namely:
217  *
218  *	enable	refcount	Status
219  *
220  *	FALSE	0		normal operation
221  *	FALSE	!= 0		-- (impossible)
222  *	TRUE	1		netmap mode
223  *	TRUE	0		being deleted.
224  */
225 
226 #define NETMAP_DELETING(_na)  (  ((_na)->refcount == 0) &&	\
227 	( (_na)->ifp->if_capenable & IFCAP_NETMAP) )
228 
229 /*
230  * parameters for (*nm_lock)(adapter, what, index)
231  */
232 enum {
233 	NETMAP_NO_LOCK = 0,
234 	NETMAP_CORE_LOCK, NETMAP_CORE_UNLOCK,
235 	NETMAP_TX_LOCK, NETMAP_TX_UNLOCK,
236 	NETMAP_RX_LOCK, NETMAP_RX_UNLOCK,
237 #ifdef __FreeBSD__
238 #define	NETMAP_REG_LOCK		NETMAP_CORE_LOCK
239 #define	NETMAP_REG_UNLOCK	NETMAP_CORE_UNLOCK
240 #else
241 	NETMAP_REG_LOCK, NETMAP_REG_UNLOCK
242 #endif
243 };
244 
245 /*
246  * The following are support routines used by individual drivers to
247  * support netmap operation.
248  *
249  * netmap_attach() initializes a struct netmap_adapter, allocating the
250  * 	struct netmap_ring's and the struct selinfo.
251  *
252  * netmap_detach() frees the memory allocated by netmap_attach().
253  *
254  * netmap_start() replaces the if_transmit routine of the interface,
255  *	and is used to intercept packets coming from the stack.
256  *
257  * netmap_load_map/netmap_reload_map are helper routines to set/reset
258  *	the dmamap for a packet buffer
259  *
260  * netmap_reset() is a helper routine to be called in the driver
261  *	when reinitializing a ring.
262  */
263 int netmap_attach(struct netmap_adapter *, int);
264 void netmap_detach(struct ifnet *);
265 int netmap_start(struct ifnet *, struct mbuf *);
266 enum txrx { NR_RX = 0, NR_TX = 1 };
267 struct netmap_slot *netmap_reset(struct netmap_adapter *na,
268 	enum txrx tx, int n, u_int new_cur);
269 int netmap_ring_reinit(struct netmap_kring *);
270 
271 extern u_int netmap_buf_size;
272 #define NETMAP_BUF_SIZE	netmap_buf_size
273 extern int netmap_mitigate;
274 extern int netmap_no_pendintr;
275 extern u_int netmap_total_buffers;
276 extern char *netmap_buffer_base;
277 extern int netmap_verbose;	// XXX debugging
278 enum {                                  /* verbose flags */
279 	NM_VERB_ON = 1,                 /* generic verbose */
280 	NM_VERB_HOST = 0x2,             /* verbose host stack */
281 	NM_VERB_RXSYNC = 0x10,          /* verbose on rxsync/txsync */
282 	NM_VERB_TXSYNC = 0x20,
283 	NM_VERB_RXINTR = 0x100,         /* verbose on rx/tx intr (driver) */
284 	NM_VERB_TXINTR = 0x200,
285 	NM_VERB_NIC_RXSYNC = 0x1000,    /* verbose on rx/tx intr (driver) */
286 	NM_VERB_NIC_TXSYNC = 0x2000,
287 };
288 
289 /*
290  * NA returns a pointer to the struct netmap adapter from the ifp,
291  * WNA is used to write it.
292  */
293 #ifndef WNA
294 #define	WNA(_ifp)	(_ifp)->if_pspare[0]
295 #endif
296 #define	NA(_ifp)	((struct netmap_adapter *)WNA(_ifp))
297 
298 /*
299  * Macros to determine if an interface is netmap capable or netmap enabled.
300  * See the magic field in struct netmap_adapter.
301  */
302 #ifdef __FreeBSD__
303 /*
304  * on FreeBSD just use if_capabilities and if_capenable.
305  */
306 #define NETMAP_CAPABLE(ifp)	(NA(ifp) &&		\
307 	(ifp)->if_capabilities & IFCAP_NETMAP )
308 
309 #define	NETMAP_SET_CAPABLE(ifp)				\
310 	(ifp)->if_capabilities |= IFCAP_NETMAP
311 
312 #else	/* linux */
313 
314 /*
315  * on linux:
316  * we check if NA(ifp) is set and its first element has a related
317  * magic value. The capenable is within the struct netmap_adapter.
318  */
319 #define	NETMAP_MAGIC	0x52697a7a
320 
321 #define NETMAP_CAPABLE(ifp)	(NA(ifp) &&		\
322 	((uint32_t)(uintptr_t)NA(ifp) ^ NA(ifp)->magic) == NETMAP_MAGIC )
323 
324 #define	NETMAP_SET_CAPABLE(ifp)				\
325 	NA(ifp)->magic = ((uint32_t)(uintptr_t)NA(ifp)) ^ NETMAP_MAGIC
326 
327 #endif	/* linux */
328 
329 #ifdef __FreeBSD__
330 /* Callback invoked by the dma machinery after a successfull dmamap_load */
331 static void netmap_dmamap_cb(__unused void *arg,
332     __unused bus_dma_segment_t * segs, __unused int nseg, __unused int error)
333 {
334 }
335 
336 /* bus_dmamap_load wrapper: call aforementioned function if map != NULL.
337  * XXX can we do it without a callback ?
338  */
339 static inline void
340 netmap_load_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
341 {
342 	if (map)
343 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
344 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
345 }
346 
347 /* update the map when a buffer changes. */
348 static inline void
349 netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
350 {
351 	if (map) {
352 		bus_dmamap_unload(tag, map);
353 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
354 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
355 	}
356 }
357 #else /* linux */
358 
359 /*
360  * XXX How do we redefine these functions:
361  *
362  * on linux we need
363  *	dma_map_single(&pdev->dev, virt_addr, len, direction)
364  *	dma_unmap_single(&adapter->pdev->dev, phys_addr, len, direction
365  * The len can be implicit (on netmap it is NETMAP_BUF_SIZE)
366  * unfortunately the direction is not, so we need to change
367  * something to have a cross API
368  */
369 #define netmap_load_map(_t, _m, _b)
370 #define netmap_reload_map(_t, _m, _b)
371 #if 0
372 	struct e1000_buffer *buffer_info =  &tx_ring->buffer_info[l];
373 	/* set time_stamp *before* dma to help avoid a possible race */
374 	buffer_info->time_stamp = jiffies;
375 	buffer_info->mapped_as_page = false;
376 	buffer_info->length = len;
377 	//buffer_info->next_to_watch = l;
378 	/* reload dma map */
379 	dma_unmap_single(&adapter->pdev->dev, buffer_info->dma,
380 			NETMAP_BUF_SIZE, DMA_TO_DEVICE);
381 	buffer_info->dma = dma_map_single(&adapter->pdev->dev,
382 			addr, NETMAP_BUF_SIZE, DMA_TO_DEVICE);
383 
384 	if (dma_mapping_error(&adapter->pdev->dev, buffer_info->dma)) {
385 		D("dma mapping error");
386 		/* goto dma_error; See e1000_put_txbuf() */
387 		/* XXX reset */
388 	}
389 	tx_desc->buffer_addr = htole64(buffer_info->dma); //XXX
390 
391 #endif
392 
393 /*
394  * The bus_dmamap_sync() can be one of wmb() or rmb() depending on direction.
395  */
396 #define bus_dmamap_sync(_a, _b, _c)
397 
398 #endif /* linux */
399 
400 /*
401  * functions to map NIC to KRING indexes (n2k) and vice versa (k2n)
402  */
403 static inline int
404 netmap_idx_n2k(struct netmap_kring *kr, int idx)
405 {
406 	int n = kr->nkr_num_slots;
407 	idx += kr->nkr_hwofs;
408 	if (idx < 0)
409 		return idx + n;
410 	else if (idx < n)
411 		return idx;
412 	else
413 		return idx - n;
414 }
415 
416 
417 static inline int
418 netmap_idx_k2n(struct netmap_kring *kr, int idx)
419 {
420 	int n = kr->nkr_num_slots;
421 	idx -= kr->nkr_hwofs;
422 	if (idx < 0)
423 		return idx + n;
424 	else if (idx < n)
425 		return idx;
426 	else
427 		return idx - n;
428 }
429 
430 
431 #ifdef NETMAP_MEM2
432 /* Entries of the look-up table. */
433 struct lut_entry {
434 	void *vaddr;		/* virtual address. */
435 	vm_paddr_t paddr;	/* phisical address. */
436 };
437 
438 struct netmap_obj_pool;
439 extern struct lut_entry *netmap_buffer_lut;
440 #define NMB_VA(i)	(netmap_buffer_lut[i].vaddr)
441 #define NMB_PA(i)	(netmap_buffer_lut[i].paddr)
442 #else /* NETMAP_MEM1 */
443 #define NMB_VA(i)	(netmap_buffer_base + (i * NETMAP_BUF_SIZE) )
444 #endif /* NETMAP_MEM2 */
445 
446 /*
447  * NMB return the virtual address of a buffer (buffer 0 on bad index)
448  * PNMB also fills the physical address
449  */
450 static inline void *
451 NMB(struct netmap_slot *slot)
452 {
453 	uint32_t i = slot->buf_idx;
454 	return (unlikely(i >= netmap_total_buffers)) ?  NMB_VA(0) : NMB_VA(i);
455 }
456 
457 static inline void *
458 PNMB(struct netmap_slot *slot, uint64_t *pp)
459 {
460 	uint32_t i = slot->buf_idx;
461 	void *ret = (i >= netmap_total_buffers) ? NMB_VA(0) : NMB_VA(i);
462 #ifdef NETMAP_MEM2
463 	*pp = (i >= netmap_total_buffers) ? NMB_PA(0) : NMB_PA(i);
464 #else
465 	*pp = vtophys(ret);
466 #endif
467 	return ret;
468 }
469 
470 /* default functions to handle rx/tx interrupts */
471 int netmap_rx_irq(struct ifnet *, int, int *);
472 #define netmap_tx_irq(_n, _q) netmap_rx_irq(_n, _q, NULL)
473 
474 extern int netmap_copy;
475 #endif /* _NET_NETMAP_KERN_H_ */
476