netmap_kern.h revision 231198
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: head/sys/dev/netmap/netmap_kern.h 231198 2012-02-08 11:43:29Z luigi $
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
38MALLOC_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
51struct 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 */
64struct 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 */
82struct 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 */
142enum {
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 */
167int netmap_attach(struct netmap_adapter *, int);
168void netmap_detach(struct ifnet *);
169int netmap_start(struct ifnet *, struct mbuf *);
170enum txrx { NR_RX = 0, NR_TX = 1 };
171struct netmap_slot *netmap_reset(struct netmap_adapter *na,
172	enum txrx tx, int n, u_int new_cur);
173int netmap_ring_reinit(struct netmap_kring *);
174
175extern int netmap_buf_size;
176#define NETMAP_BUF_SIZE netmap_buf_size
177extern int netmap_mitigate;
178extern int netmap_no_pendintr;
179extern u_int netmap_total_buffers;
180extern char *netmap_buffer_base;
181extern int netmap_verbose;	// XXX debugging
182enum {                                  /* verbose flags */
183	NM_VERB_ON = 1,                 /* generic verbose */
184	NM_VERB_HOST = 0x2,             /* verbose host stack */
185	NM_VERB_RXSYNC = 0x10,          /* verbose on rxsync/txsync */
186	NM_VERB_TXSYNC = 0x20,
187	NM_VERB_RXINTR = 0x100,         /* verbose on rx/tx intr (driver) */
188	NM_VERB_TXINTR = 0x200,
189	NM_VERB_NIC_RXSYNC = 0x1000,    /* verbose on rx/tx intr (driver) */
190	NM_VERB_NIC_TXSYNC = 0x2000,
191};
192
193/*
194 * NA returns a pointer to the struct netmap adapter from the ifp,
195 * WNA is used to write it.
196 */
197#ifndef WNA
198#define	WNA(_ifp)	(_ifp)->if_pspare[0]
199#endif
200#define	NA(_ifp)	((struct netmap_adapter *)WNA(_ifp))
201
202
203/* Callback invoked by the dma machinery after a successfull dmamap_load */
204static void netmap_dmamap_cb(__unused void *arg,
205    __unused bus_dma_segment_t * segs, __unused int nseg, __unused int error)
206{
207}
208
209/* bus_dmamap_load wrapper: call aforementioned function if map != NULL.
210 * XXX can we do it without a callback ?
211 */
212static inline void
213netmap_load_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
214{
215	if (map)
216		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
217		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
218}
219
220/* update the map when a buffer changes. */
221static inline void
222netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
223{
224	if (map) {
225		bus_dmamap_unload(tag, map);
226		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
227		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
228	}
229}
230
231
232/*
233 * NMB return the virtual address of a buffer (buffer 0 on bad index)
234 * PNMB also fills the physical address
235 */
236static inline void *
237NMB(struct netmap_slot *slot)
238{
239	uint32_t i = slot->buf_idx;
240	return (i >= netmap_total_buffers) ? netmap_buffer_base :
241		netmap_buffer_base + (i *NETMAP_BUF_SIZE);
242}
243
244static inline void *
245PNMB(struct netmap_slot *slot, uint64_t *pp)
246{
247	uint32_t i = slot->buf_idx;
248	void *ret = (i >= netmap_total_buffers) ? netmap_buffer_base :
249		netmap_buffer_base + (i *NETMAP_BUF_SIZE);
250	*pp = vtophys(ret);
251	return ret;
252}
253
254#endif /* _NET_NETMAP_KERN_H_ */
255