xref: /freebsd/sys/dev/ath/if_athrate.h (revision db612abe8df3355d1eb23bb3b50fdd97bc21e979)
1 /*-
2  * Copyright (c) 2004-2008 Sam Leffler, Errno Consulting
3  * Copyright (c) 2004 Video54 Technologies, Inc.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer,
11  *    without modification.
12  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
13  *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
14  *    redistribution must be conditioned upon including a substantially
15  *    similar Disclaimer requirement for further binary redistribution.
16  *
17  * NO WARRANTY
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
21  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
22  * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
23  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
26  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
28  * THE POSSIBILITY OF SUCH DAMAGES.
29  *
30  * $FreeBSD$
31  */
32 #ifndef _ATH_RATECTRL_H_
33 #define _ATH_RATECTRL_H_
34 
35 /*
36  * Interface definitions for transmit rate control modules for the
37  * Atheros driver.
38  *
39  * A rate control module is responsible for choosing the transmit rate
40  * for each data frame.  Management+control frames are always sent at
41  * a fixed rate.
42  *
43  * Only one module may be present at a time; the driver references
44  * rate control interfaces by symbol name.  If multiple modules are
45  * to be supported we'll need to switch to a registration-based scheme
46  * as is currently done, for example, for authentication modules.
47  *
48  * An instance of the rate control module is attached to each device
49  * at attach time and detached when the device is destroyed.  The module
50  * may associate data with each device and each node (station).  Both
51  * sets of storage are opaque except for the size of the per-node storage
52  * which must be provided when the module is attached.
53  *
54  * The rate control module is notified for each state transition and
55  * station association/reassociation.  Otherwise it is queried for a
56  * rate for each outgoing frame and provided status from each transmitted
57  * frame.  Any ancillary processing is the responsibility of the module
58  * (e.g. if periodic processing is required then the module should setup
59  * it's own timer).
60  *
61  * In addition to the transmit rate for each frame the module must also
62  * indicate the number of attempts to make at the specified rate.  If this
63  * number is != ATH_TXMAXTRY then an additional callback is made to setup
64  * additional transmit state.  The rate control code is assumed to write
65  * this additional data directly to the transmit descriptor.
66  */
67 struct ath_softc;
68 struct ath_node;
69 struct ath_desc;
70 
71 struct ath_ratectrl {
72 	size_t	arc_space;	/* space required for per-node state */
73 };
74 /*
75  * Attach/detach a rate control module.
76  */
77 struct ath_ratectrl *ath_rate_attach(struct ath_softc *);
78 void	ath_rate_detach(struct ath_ratectrl *);
79 
80 
81 /*
82  * State storage handling.
83  */
84 /*
85  * Initialize per-node state already allocated for the specified
86  * node; this space can be assumed initialized to zero.
87  */
88 void	ath_rate_node_init(struct ath_softc *, struct ath_node *);
89 /*
90  * Cleanup any per-node state prior to the node being reclaimed.
91  */
92 void	ath_rate_node_cleanup(struct ath_softc *, struct ath_node *);
93 /*
94  * Update rate control state on station associate/reassociate
95  * (when operating as an ap or for nodes discovered when operating
96  * in ibss mode).
97  */
98 void	ath_rate_newassoc(struct ath_softc *, struct ath_node *,
99 		int isNewAssociation);
100 /*
101  * Update/reset rate control state for 802.11 state transitions.
102  * Important mostly as the analog to ath_rate_newassoc when operating
103  * in station mode.
104  */
105 void	ath_rate_newstate(struct ieee80211vap *, enum ieee80211_state);
106 
107 /*
108  * Transmit handling.
109  */
110 /*
111  * Return the transmit info for a data packet.  If multi-rate state
112  * is to be setup then try0 should contain a value other than ATH_TXMATRY
113  * and ath_rate_setupxtxdesc will be called after deciding if the frame
114  * can be transmitted with multi-rate retry.
115  */
116 void	ath_rate_findrate(struct ath_softc *, struct ath_node *,
117 		int shortPreamble, size_t frameLen,
118 		u_int8_t *rix, int *try0, u_int8_t *txrate);
119 /*
120  * Setup any extended (multi-rate) descriptor state for a data packet.
121  * The rate index returned by ath_rate_findrate is passed back in.
122  */
123 void	ath_rate_setupxtxdesc(struct ath_softc *, struct ath_node *,
124 		struct ath_desc *, int shortPreamble, u_int8_t rix);
125 /*
126  * Update rate control state for a packet associated with the
127  * supplied transmit descriptor.  The routine is invoked both
128  * for packets that were successfully sent and for those that
129  * failed (consult the descriptor for details).
130  */
131 struct ath_buf;
132 void	ath_rate_tx_complete(struct ath_softc *, struct ath_node *,
133 		const struct ath_buf *);
134 #endif /* _ATH_RATECTRL_H_ */
135