xref: /freebsd/sys/dev/netmap/netmap_kern.h (revision b1d046441de9053152c7cf03d6b60d9882687e1b)
1 /*
2  * Copyright (C) 2011 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 9795 2011-12-02 11:39:08Z 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 #ifdef MALLOC_DECLARE
38 MALLOC_DECLARE(M_NETMAP);
39 #endif
40 
41 #define ND(format, ...)
42 #define D(format, ...)						\
43 	do {							\
44 		struct timeval __xxts;				\
45 		microtime(&__xxts);				\
46 		printf("%03d.%06d %s [%d] " format "\n",	\
47 		(int)__xxts.tv_sec % 1000, (int)__xxts.tv_usec,	\
48 		__FUNCTION__, __LINE__, ##__VA_ARGS__);		\
49 	} while (0)
50 
51 struct netmap_adapter;
52 
53 /*
54  * private, kernel view of a ring.
55  *
56  * XXX 20110627-todo
57  * The index in the NIC and netmap ring is offset by nkr_hwofs slots.
58  * This is so that, on a reset, buffers owned by userspace are not
59  * modified by the kernel. In particular:
60  * RX rings: the next empty buffer (hwcur + hwavail + hwofs) coincides
61  * 	the next empty buffer as known by the hardware (next_to_check or so).
62  * TX rings: hwcur + hwofs coincides with next_to_send
63  */
64 struct netmap_kring {
65 	struct netmap_ring *ring;
66 	u_int nr_hwcur;
67 	int nr_hwavail;
68 	u_int nr_kflags;
69 	u_int nkr_num_slots;
70 
71 	int	nkr_hwofs;	/* offset between NIC and netmap ring */
72 	struct netmap_adapter *na;	 // debugging
73 	struct selinfo si; /* poll/select wait queue */
74 };
75 
76 /*
77  * This struct is part of and extends the 'struct adapter' (or
78  * equivalent) device descriptor. It contains all fields needed to
79  * support netmap operation.
80  */
81 struct netmap_adapter {
82 	int refcount; /* number of user-space descriptors using this
83 			 interface, which is equal to the number of
84 			 struct netmap_if objs in the mapped region. */
85 
86 	int separate_locks; /* set if the interface suports different
87 			       locks for rx, tx and core. */
88 
89 	u_int num_queues; /* number of tx/rx queue pairs: this is
90 			   a duplicate field needed to simplify the
91 			   signature of ``netmap_detach``. */
92 
93 	u_int num_tx_desc; /* number of descriptor in each queue */
94 	u_int num_rx_desc;
95 	u_int buff_size;
96 
97 	u_int	flags;
98 	/* tx_rings and rx_rings are private but allocated
99 	 * as a contiguous chunk of memory. Each array has
100 	 * N+1 entries, for the adapter queues and for the host queue.
101 	 */
102 	struct netmap_kring *tx_rings; /* array of TX rings. */
103 	struct netmap_kring *rx_rings; /* array of RX rings. */
104 
105 	/* copy of if_qflush and if_transmit pointers, to intercept
106 	 * packets from the network stack when netmap is active.
107 	 * XXX probably if_qflush is not necessary.
108 	 */
109 	void    (*if_qflush)(struct ifnet *);
110 	int     (*if_transmit)(struct ifnet *, struct mbuf *);
111 
112 	/* references to the ifnet and device routines, used by
113 	 * the generic netmap functions.
114 	 */
115 	struct ifnet *ifp; /* adapter is ifp->if_softc */
116 
117 	int (*nm_register)(struct ifnet *, int onoff);
118 	void (*nm_lock)(void *, int what, u_int ringid);
119 	int (*nm_txsync)(void *, u_int ring, int lock);
120 	int (*nm_rxsync)(void *, u_int ring, int lock);
121 };
122 
123 /*
124  * The combination of "enable" (ifp->if_capabilities &IFCAP_NETMAP)
125  * and refcount gives the status of the interface, namely:
126  *
127  *	enable	refcount	Status
128  *
129  *	FALSE	0		normal operation
130  *	FALSE	!= 0		-- (impossible)
131  *	TRUE	1		netmap mode
132  *	TRUE	0		being deleted.
133  */
134 
135 #define NETMAP_DELETING(_na)  (  ((_na)->refcount == 0) &&	\
136 	( (_na)->ifp->if_capenable & IFCAP_NETMAP) )
137 
138 /*
139  * parameters for (*nm_lock)(adapter, what, index)
140  */
141 enum {
142 	NETMAP_NO_LOCK = 0,
143 	NETMAP_CORE_LOCK, NETMAP_CORE_UNLOCK,
144 	NETMAP_TX_LOCK, NETMAP_TX_UNLOCK,
145 	NETMAP_RX_LOCK, NETMAP_RX_UNLOCK,
146 };
147 
148 /*
149  * The following are support routines used by individual drivers to
150  * support netmap operation.
151  *
152  * netmap_attach() initializes a struct netmap_adapter, allocating the
153  * 	struct netmap_ring's and the struct selinfo.
154  *
155  * netmap_detach() frees the memory allocated by netmap_attach().
156  *
157  * netmap_start() replaces the if_transmit routine of the interface,
158  *	and is used to intercept packets coming from the stack.
159  *
160  * netmap_load_map/netmap_reload_map are helper routines to set/reset
161  *	the dmamap for a packet buffer
162  *
163  * netmap_reset() is a helper routine to be called in the driver
164  *	when reinitializing a ring.
165  */
166 int netmap_attach(struct netmap_adapter *, int);
167 void netmap_detach(struct ifnet *);
168 int netmap_start(struct ifnet *, struct mbuf *);
169 enum txrx { NR_RX = 0, NR_TX = 1 };
170 struct netmap_slot *netmap_reset(struct netmap_adapter *na,
171 	enum txrx tx, int n, u_int new_cur);
172 int netmap_ring_reinit(struct netmap_kring *);
173 
174 extern u_int netmap_total_buffers;
175 extern char *netmap_buffer_base;
176 extern int netmap_verbose;	// XXX debugging
177 enum {                                  /* verbose flags */
178 	NM_VERB_ON = 1,                 /* generic verbose */
179 	NM_VERB_HOST = 0x2,             /* verbose host stack */
180 	NM_VERB_RXSYNC = 0x10,          /* verbose on rxsync/txsync */
181 	NM_VERB_TXSYNC = 0x20,
182 	NM_VERB_RXINTR = 0x100,         /* verbose on rx/tx intr (driver) */
183 	NM_VERB_TXINTR = 0x200,
184 	NM_VERB_NIC_RXSYNC = 0x1000,    /* verbose on rx/tx intr (driver) */
185 	NM_VERB_NIC_TXSYNC = 0x2000,
186 };
187 
188 /*
189  * NA returns a pointer to the struct netmap adapter from the ifp,
190  * WNA is used to write it.
191  */
192 #ifndef WNA
193 #define	WNA(_ifp)	(_ifp)->if_pspare[0]
194 #endif
195 #define	NA(_ifp)	((struct netmap_adapter *)WNA(_ifp))
196 
197 
198 /* Callback invoked by the dma machinery after a successfull dmamap_load */
199 static void netmap_dmamap_cb(__unused void *arg,
200     __unused bus_dma_segment_t * segs, __unused int nseg, __unused int error)
201 {
202 }
203 
204 /* bus_dmamap_load wrapper: call aforementioned function if map != NULL.
205  * XXX can we do it without a callback ?
206  */
207 static inline void
208 netmap_load_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
209 {
210 	if (map)
211 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
212 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
213 }
214 
215 /* update the map when a buffer changes. */
216 static inline void
217 netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
218 {
219 	if (map) {
220 		bus_dmamap_unload(tag, map);
221 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
222 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
223 	}
224 }
225 
226 
227 /*
228  * NMB return the virtual address of a buffer (buffer 0 on bad index)
229  * PNMB also fills the physical address
230  */
231 static inline void *
232 NMB(struct netmap_slot *slot)
233 {
234 	uint32_t i = slot->buf_idx;
235 	return (i >= netmap_total_buffers) ? netmap_buffer_base :
236 #if NETMAP_BUF_SIZE == 2048
237 		netmap_buffer_base + (i << 11);
238 #else
239 		netmap_buffer_base + (i *NETMAP_BUF_SIZE);
240 #endif
241 }
242 
243 static inline void *
244 PNMB(struct netmap_slot *slot, uint64_t *pp)
245 {
246 	uint32_t i = slot->buf_idx;
247 	void *ret = (i >= netmap_total_buffers) ? netmap_buffer_base :
248 #if NETMAP_BUF_SIZE == 2048
249 		netmap_buffer_base + (i << 11);
250 #else
251 		netmap_buffer_base + (i *NETMAP_BUF_SIZE);
252 #endif
253 	*pp = vtophys(ret);
254 	return ret;
255 }
256 
257 #endif /* _NET_NETMAP_KERN_H_ */
258