xref: /freebsd-14.2/sys/dev/netmap/netmap_kern.h (revision 7106ed25)
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;	/* private driver flags */
69 #define NKR_PENDINTR   0x1     // Pending interrupt.
70 	u_int nkr_num_slots;
71 
72 	int	nkr_hwofs;	/* offset between NIC and netmap ring */
73 	struct netmap_adapter *na;	 // debugging
74 	struct selinfo si; /* poll/select wait queue */
75 } __attribute__((__aligned__(64)));
76 
77 /*
78  * This struct is part of and extends the 'struct adapter' (or
79  * equivalent) device descriptor. It contains all fields needed to
80  * support netmap operation.
81  */
82 struct netmap_adapter {
83 	int refcount; /* number of user-space descriptors using this
84 			 interface, which is equal to the number of
85 			 struct netmap_if objs in the mapped region. */
86 
87 	int separate_locks; /* set if the interface suports different
88 			       locks for rx, tx and core. */
89 
90 	u_int num_queues; /* number of tx/rx queue pairs: this is
91 			   a duplicate field needed to simplify the
92 			   signature of ``netmap_detach``. */
93 
94 	u_int num_tx_desc; /* number of descriptor in each queue */
95 	u_int num_rx_desc;
96 	u_int buff_size;
97 
98 	u_int	flags;
99 	/* tx_rings and rx_rings are private but allocated
100 	 * as a contiguous chunk of memory. Each array has
101 	 * N+1 entries, for the adapter queues and for the host queue.
102 	 */
103 	struct netmap_kring *tx_rings; /* array of TX rings. */
104 	struct netmap_kring *rx_rings; /* array of RX rings. */
105 
106 	/* copy of if_qflush and if_transmit pointers, to intercept
107 	 * packets from the network stack when netmap is active.
108 	 * XXX probably if_qflush is not necessary.
109 	 */
110 	void    (*if_qflush)(struct ifnet *);
111 	int     (*if_transmit)(struct ifnet *, struct mbuf *);
112 
113 	/* references to the ifnet and device routines, used by
114 	 * the generic netmap functions.
115 	 */
116 	struct ifnet *ifp; /* adapter is ifp->if_softc */
117 
118 	int (*nm_register)(struct ifnet *, int onoff);
119 	void (*nm_lock)(void *, int what, u_int ringid);
120 	int (*nm_txsync)(void *, u_int ring, int lock);
121 	int (*nm_rxsync)(void *, u_int ring, int lock);
122 };
123 
124 /*
125  * The combination of "enable" (ifp->if_capabilities &IFCAP_NETMAP)
126  * and refcount gives the status of the interface, namely:
127  *
128  *	enable	refcount	Status
129  *
130  *	FALSE	0		normal operation
131  *	FALSE	!= 0		-- (impossible)
132  *	TRUE	1		netmap mode
133  *	TRUE	0		being deleted.
134  */
135 
136 #define NETMAP_DELETING(_na)  (  ((_na)->refcount == 0) &&	\
137 	( (_na)->ifp->if_capenable & IFCAP_NETMAP) )
138 
139 /*
140  * parameters for (*nm_lock)(adapter, what, index)
141  */
142 enum {
143 	NETMAP_NO_LOCK = 0,
144 	NETMAP_CORE_LOCK, NETMAP_CORE_UNLOCK,
145 	NETMAP_TX_LOCK, NETMAP_TX_UNLOCK,
146 	NETMAP_RX_LOCK, NETMAP_RX_UNLOCK,
147 };
148 
149 /*
150  * The following are support routines used by individual drivers to
151  * support netmap operation.
152  *
153  * netmap_attach() initializes a struct netmap_adapter, allocating the
154  * 	struct netmap_ring's and the struct selinfo.
155  *
156  * netmap_detach() frees the memory allocated by netmap_attach().
157  *
158  * netmap_start() replaces the if_transmit routine of the interface,
159  *	and is used to intercept packets coming from the stack.
160  *
161  * netmap_load_map/netmap_reload_map are helper routines to set/reset
162  *	the dmamap for a packet buffer
163  *
164  * netmap_reset() is a helper routine to be called in the driver
165  *	when reinitializing a ring.
166  */
167 int netmap_attach(struct netmap_adapter *, int);
168 void netmap_detach(struct ifnet *);
169 int netmap_start(struct ifnet *, struct mbuf *);
170 enum txrx { NR_RX = 0, NR_TX = 1 };
171 struct netmap_slot *netmap_reset(struct netmap_adapter *na,
172 	enum txrx tx, int n, u_int new_cur);
173 int netmap_ring_reinit(struct netmap_kring *);
174 
175 extern int netmap_mitigate;
176 extern int netmap_skip_txsync, netmap_skip_rxsync;
177 extern u_int netmap_total_buffers;
178 extern char *netmap_buffer_base;
179 extern int netmap_verbose;	// XXX debugging
180 enum {                                  /* verbose flags */
181 	NM_VERB_ON = 1,                 /* generic verbose */
182 	NM_VERB_HOST = 0x2,             /* verbose host stack */
183 	NM_VERB_RXSYNC = 0x10,          /* verbose on rxsync/txsync */
184 	NM_VERB_TXSYNC = 0x20,
185 	NM_VERB_RXINTR = 0x100,         /* verbose on rx/tx intr (driver) */
186 	NM_VERB_TXINTR = 0x200,
187 	NM_VERB_NIC_RXSYNC = 0x1000,    /* verbose on rx/tx intr (driver) */
188 	NM_VERB_NIC_TXSYNC = 0x2000,
189 };
190 
191 /*
192  * NA returns a pointer to the struct netmap adapter from the ifp,
193  * WNA is used to write it.
194  */
195 #ifndef WNA
196 #define	WNA(_ifp)	(_ifp)->if_pspare[0]
197 #endif
198 #define	NA(_ifp)	((struct netmap_adapter *)WNA(_ifp))
199 
200 
201 /* Callback invoked by the dma machinery after a successfull dmamap_load */
202 static void netmap_dmamap_cb(__unused void *arg,
203     __unused bus_dma_segment_t * segs, __unused int nseg, __unused int error)
204 {
205 }
206 
207 /* bus_dmamap_load wrapper: call aforementioned function if map != NULL.
208  * XXX can we do it without a callback ?
209  */
210 static inline void
211 netmap_load_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
212 {
213 	if (map)
214 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
215 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
216 }
217 
218 /* update the map when a buffer changes. */
219 static inline void
220 netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
221 {
222 	if (map) {
223 		bus_dmamap_unload(tag, map);
224 		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
225 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
226 	}
227 }
228 
229 
230 /*
231  * NMB return the virtual address of a buffer (buffer 0 on bad index)
232  * PNMB also fills the physical address
233  */
234 static inline void *
235 NMB(struct netmap_slot *slot)
236 {
237 	uint32_t i = slot->buf_idx;
238 	return (i >= netmap_total_buffers) ? netmap_buffer_base :
239 #if NETMAP_BUF_SIZE == 2048
240 		netmap_buffer_base + (i << 11);
241 #else
242 		netmap_buffer_base + (i *NETMAP_BUF_SIZE);
243 #endif
244 }
245 
246 static inline void *
247 PNMB(struct netmap_slot *slot, uint64_t *pp)
248 {
249 	uint32_t i = slot->buf_idx;
250 	void *ret = (i >= netmap_total_buffers) ? netmap_buffer_base :
251 #if NETMAP_BUF_SIZE == 2048
252 		netmap_buffer_base + (i << 11);
253 #else
254 		netmap_buffer_base + (i *NETMAP_BUF_SIZE);
255 #endif
256 	*pp = vtophys(ret);
257 	return ret;
258 }
259 
260 #endif /* _NET_NETMAP_KERN_H_ */
261