xref: /freebsd/sys/dev/netmap/netmap_kern.h (revision c6ec7d31830ab1c80edae95ad5e4b9dba10c47ac)
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 struct netmap_kring {
124 	struct netmap_ring *ring;
125 	u_int nr_hwcur;
126 	int nr_hwavail;
127 	u_int nr_kflags;	/* private driver flags */
128 #define NKR_PENDINTR	0x1	// Pending interrupt.
129 	u_int nkr_num_slots;
130 
131 	int	nkr_hwofs;	/* offset between NIC and netmap ring */
132 	struct netmap_adapter *na;
133 	NM_SELINFO_T si;	/* poll/select wait queue */
134 	NM_LOCK_T q_lock;	/* used if no device lock available */
135 } __attribute__((__aligned__(64)));
136 
137 /*
138  * This struct extends the 'struct adapter' (or
139  * equivalent) device descriptor. It contains all fields needed to
140  * support netmap operation.
141  */
142 struct netmap_adapter {
143 	/*
144 	 * On linux we do not have a good way to tell if an interface
145 	 * is netmap-capable. So we use the following trick:
146 	 * NA(ifp) points here, and the first entry (which hopefully
147 	 * always exists and is at least 32 bits) contains a magic
148 	 * value which we can use to detect that the interface is good.
149 	 */
150 	uint32_t magic;
151 	uint32_t na_flags;	/* future place for IFCAP_NETMAP */
152 #define NAF_SKIP_INTR	1	/* use the regular interrupt handler.
153 				 * useful during initialization
154 				 */
155 	int refcount; /* number of user-space descriptors using this
156 			 interface, which is equal to the number of
157 			 struct netmap_if objs in the mapped region. */
158 	/*
159 	 * The selwakeup in the interrupt thread can use per-ring
160 	 * and/or global wait queues. We track how many clients
161 	 * of each type we have so we can optimize the drivers,
162 	 * and especially avoid huge contention on the locks.
163 	 */
164 	int na_single;	/* threads attached to a single hw queue */
165 	int na_multi;	/* threads attached to multiple hw queues */
166 
167 	int separate_locks; /* set if the interface suports different
168 			       locks for rx, tx and core. */
169 
170 	u_int num_rx_rings; /* number of adapter receive rings */
171 	u_int num_tx_rings; /* number of adapter transmit rings */
172 
173 	u_int num_tx_desc; /* number of descriptor in each queue */
174 	u_int num_rx_desc;
175 
176 	/* tx_rings and rx_rings are private but allocated
177 	 * as a contiguous chunk of memory. Each array has
178 	 * N+1 entries, for the adapter queues and for the host queue.
179 	 */
180 	struct netmap_kring *tx_rings; /* array of TX rings. */
181 	struct netmap_kring *rx_rings; /* array of RX rings. */
182 
183 	NM_SELINFO_T tx_si, rx_si;	/* global wait queues */
184 
185 	/* copy of if_qflush and if_transmit pointers, to intercept
186 	 * packets from the network stack when netmap is active.
187 	 */
188 	int     (*if_transmit)(struct ifnet *, struct mbuf *);
189 
190 	/* references to the ifnet and device routines, used by
191 	 * the generic netmap functions.
192 	 */
193 	struct ifnet *ifp; /* adapter is ifp->if_softc */
194 
195 	NM_LOCK_T core_lock;	/* used if no device lock available */
196 
197 	int (*nm_register)(struct ifnet *, int onoff);
198 	void (*nm_lock)(struct ifnet *, int what, u_int ringid);
199 	int (*nm_txsync)(struct ifnet *, u_int ring, int lock);
200 	int (*nm_rxsync)(struct ifnet *, u_int ring, int lock);
201 
202 	int bdg_port;
203 #ifdef linux
204 	struct net_device_ops nm_ndo;
205 	int if_refcount;	// XXX additions for bridge
206 #endif /* linux */
207 };
208 
209 /*
210  * The combination of "enable" (ifp->if_capenable & IFCAP_NETMAP)
211  * and refcount gives the status of the interface, namely:
212  *
213  *	enable	refcount	Status
214  *
215  *	FALSE	0		normal operation
216  *	FALSE	!= 0		-- (impossible)
217  *	TRUE	1		netmap mode
218  *	TRUE	0		being deleted.
219  */
220 
221 #define NETMAP_DELETING(_na)  (  ((_na)->refcount == 0) &&	\
222 	( (_na)->ifp->if_capenable & IFCAP_NETMAP) )
223 
224 /*
225  * parameters for (*nm_lock)(adapter, what, index)
226  */
227 enum {
228 	NETMAP_NO_LOCK = 0,
229 	NETMAP_CORE_LOCK, NETMAP_CORE_UNLOCK,
230 	NETMAP_TX_LOCK, NETMAP_TX_UNLOCK,
231 	NETMAP_RX_LOCK, NETMAP_RX_UNLOCK,
232 #ifdef __FreeBSD__
233 #define	NETMAP_REG_LOCK		NETMAP_CORE_LOCK
234 #define	NETMAP_REG_UNLOCK	NETMAP_CORE_UNLOCK
235 #else
236 	NETMAP_REG_LOCK, NETMAP_REG_UNLOCK
237 #endif
238 };
239 
240 /*
241  * The following are support routines used by individual drivers to
242  * support netmap operation.
243  *
244  * netmap_attach() initializes a struct netmap_adapter, allocating the
245  * 	struct netmap_ring's and the struct selinfo.
246  *
247  * netmap_detach() frees the memory allocated by netmap_attach().
248  *
249  * netmap_start() replaces the if_transmit routine of the interface,
250  *	and is used to intercept packets coming from the stack.
251  *
252  * netmap_load_map/netmap_reload_map are helper routines to set/reset
253  *	the dmamap for a packet buffer
254  *
255  * netmap_reset() is a helper routine to be called in the driver
256  *	when reinitializing a ring.
257  */
258 int netmap_attach(struct netmap_adapter *, int);
259 void netmap_detach(struct ifnet *);
260 int netmap_start(struct ifnet *, struct mbuf *);
261 enum txrx { NR_RX = 0, NR_TX = 1 };
262 struct netmap_slot *netmap_reset(struct netmap_adapter *na,
263 	enum txrx tx, int n, u_int new_cur);
264 int netmap_ring_reinit(struct netmap_kring *);
265 
266 extern u_int netmap_buf_size;
267 #define NETMAP_BUF_SIZE	netmap_buf_size
268 extern int netmap_mitigate;
269 extern int netmap_no_pendintr;
270 extern u_int netmap_total_buffers;
271 extern char *netmap_buffer_base;
272 extern int netmap_verbose;	// XXX debugging
273 enum {                                  /* verbose flags */
274 	NM_VERB_ON = 1,                 /* generic verbose */
275 	NM_VERB_HOST = 0x2,             /* verbose host stack */
276 	NM_VERB_RXSYNC = 0x10,          /* verbose on rxsync/txsync */
277 	NM_VERB_TXSYNC = 0x20,
278 	NM_VERB_RXINTR = 0x100,         /* verbose on rx/tx intr (driver) */
279 	NM_VERB_TXINTR = 0x200,
280 	NM_VERB_NIC_RXSYNC = 0x1000,    /* verbose on rx/tx intr (driver) */
281 	NM_VERB_NIC_TXSYNC = 0x2000,
282 };
283 
284 /*
285  * NA returns a pointer to the struct netmap adapter from the ifp,
286  * WNA is used to write it.
287  */
288 #ifndef WNA
289 #define	WNA(_ifp)	(_ifp)->if_pspare[0]
290 #endif
291 #define	NA(_ifp)	((struct netmap_adapter *)WNA(_ifp))
292 
293 /*
294  * Macros to determine if an interface is netmap capable or netmap enabled.
295  * See the magic field in struct netmap_adapter.
296  */
297 #ifdef __FreeBSD__
298 /*
299  * on FreeBSD just use if_capabilities and if_capenable.
300  */
301 #define NETMAP_CAPABLE(ifp)	(NA(ifp) &&		\
302 	(ifp)->if_capabilities & IFCAP_NETMAP )
303 
304 #define	NETMAP_SET_CAPABLE(ifp)				\
305 	(ifp)->if_capabilities |= IFCAP_NETMAP
306 
307 #else	/* linux */
308 
309 /*
310  * on linux:
311  * we check if NA(ifp) is set and its first element has a related
312  * magic value. The capenable is within the struct netmap_adapter.
313  */
314 #define	NETMAP_MAGIC	0x52697a7a
315 
316 #define NETMAP_CAPABLE(ifp)	(NA(ifp) &&		\
317 	((uint32_t)(uintptr_t)NA(ifp) ^ NA(ifp)->magic) == NETMAP_MAGIC )
318 
319 #define	NETMAP_SET_CAPABLE(ifp)				\
320 	NA(ifp)->magic = ((uint32_t)(uintptr_t)NA(ifp)) ^ NETMAP_MAGIC
321 
322 #endif	/* linux */
323 
324 #ifdef __FreeBSD__
325 /* Callback invoked by the dma machinery after a successfull dmamap_load */
326 static void netmap_dmamap_cb(__unused void *arg,
327     __unused bus_dma_segment_t * segs, __unused int nseg, __unused int error)
328 {
329 }
330 
331 /* bus_dmamap_load wrapper: call aforementioned function if map != NULL.
332  * XXX can we do it without a callback ?
333  */
334 static inline void
335 netmap_load_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
336 {
337 	if (map)
338 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
339 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
340 }
341 
342 /* update the map when a buffer changes. */
343 static inline void
344 netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
345 {
346 	if (map) {
347 		bus_dmamap_unload(tag, map);
348 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
349 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
350 	}
351 }
352 #else /* linux */
353 
354 /*
355  * XXX How do we redefine these functions:
356  *
357  * on linux we need
358  *	dma_map_single(&pdev->dev, virt_addr, len, direction)
359  *	dma_unmap_single(&adapter->pdev->dev, phys_addr, len, direction
360  * The len can be implicit (on netmap it is NETMAP_BUF_SIZE)
361  * unfortunately the direction is not, so we need to change
362  * something to have a cross API
363  */
364 #define netmap_load_map(_t, _m, _b)
365 #define netmap_reload_map(_t, _m, _b)
366 #if 0
367 	struct e1000_buffer *buffer_info =  &tx_ring->buffer_info[l];
368 	/* set time_stamp *before* dma to help avoid a possible race */
369 	buffer_info->time_stamp = jiffies;
370 	buffer_info->mapped_as_page = false;
371 	buffer_info->length = len;
372 	//buffer_info->next_to_watch = l;
373 	/* reload dma map */
374 	dma_unmap_single(&adapter->pdev->dev, buffer_info->dma,
375 			NETMAP_BUF_SIZE, DMA_TO_DEVICE);
376 	buffer_info->dma = dma_map_single(&adapter->pdev->dev,
377 			addr, NETMAP_BUF_SIZE, DMA_TO_DEVICE);
378 
379 	if (dma_mapping_error(&adapter->pdev->dev, buffer_info->dma)) {
380 		D("dma mapping error");
381 		/* goto dma_error; See e1000_put_txbuf() */
382 		/* XXX reset */
383 	}
384 	tx_desc->buffer_addr = htole64(buffer_info->dma); //XXX
385 
386 #endif
387 
388 /*
389  * The bus_dmamap_sync() can be one of wmb() or rmb() depending on direction.
390  */
391 #define bus_dmamap_sync(_a, _b, _c)
392 
393 #endif /* linux */
394 
395 /*
396  * functions to map NIC to KRING indexes (n2k) and vice versa (k2n)
397  */
398 static inline int
399 netmap_idx_n2k(struct netmap_kring *kr, int idx)
400 {
401 	int n = kr->nkr_num_slots;
402 	idx += kr->nkr_hwofs;
403 	if (idx < 0)
404 		return idx + n;
405 	else if (idx < n)
406 		return idx;
407 	else
408 		return idx - n;
409 }
410 
411 
412 static inline int
413 netmap_idx_k2n(struct netmap_kring *kr, int idx)
414 {
415 	int n = kr->nkr_num_slots;
416 	idx -= kr->nkr_hwofs;
417 	if (idx < 0)
418 		return idx + n;
419 	else if (idx < n)
420 		return idx;
421 	else
422 		return idx - n;
423 }
424 
425 
426 #ifdef NETMAP_MEM2
427 /* Entries of the look-up table. */
428 struct lut_entry {
429 	void *vaddr;		/* virtual address. */
430 	vm_paddr_t paddr;	/* phisical address. */
431 };
432 
433 struct netmap_obj_pool;
434 extern struct lut_entry *netmap_buffer_lut;
435 #define NMB_VA(i)	(netmap_buffer_lut[i].vaddr)
436 #define NMB_PA(i)	(netmap_buffer_lut[i].paddr)
437 #else /* NETMAP_MEM1 */
438 #define NMB_VA(i)	(netmap_buffer_base + (i * NETMAP_BUF_SIZE) )
439 #endif /* NETMAP_MEM2 */
440 
441 /*
442  * NMB return the virtual address of a buffer (buffer 0 on bad index)
443  * PNMB also fills the physical address
444  */
445 static inline void *
446 NMB(struct netmap_slot *slot)
447 {
448 	uint32_t i = slot->buf_idx;
449 	return (unlikely(i >= netmap_total_buffers)) ?  NMB_VA(0) : NMB_VA(i);
450 }
451 
452 static inline void *
453 PNMB(struct netmap_slot *slot, uint64_t *pp)
454 {
455 	uint32_t i = slot->buf_idx;
456 	void *ret = (i >= netmap_total_buffers) ? NMB_VA(0) : NMB_VA(i);
457 #ifdef NETMAP_MEM2
458 	*pp = (i >= netmap_total_buffers) ? NMB_PA(0) : NMB_PA(i);
459 #else
460 	*pp = vtophys(ret);
461 #endif
462 	return ret;
463 }
464 
465 /* default functions to handle rx/tx interrupts */
466 int netmap_rx_irq(struct ifnet *, int, int *);
467 #define netmap_tx_irq(_n, _q) netmap_rx_irq(_n, _q, NULL)
468 
469 extern int netmap_copy;
470 #endif /* _NET_NETMAP_KERN_H_ */
471