xref: /freebsd/sys/dev/ath/if_athrate.h (revision 7bd6fde3)
1 /*-
2  * Copyright (c) 2004-2005 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  * 3. Neither the names of the above-listed copyright holders nor the names
17  *    of any contributors may be used to endorse or promote products derived
18  *    from this software without specific prior written permission.
19  *
20  * Alternatively, this software may be distributed under the terms of the
21  * GNU General Public License ("GPL") version 2 as published by the Free
22  * Software Foundation.
23  *
24  * NO WARRANTY
25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27  * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
28  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
29  * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
30  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
33  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
35  * THE POSSIBILITY OF SUCH DAMAGES.
36  *
37  * $FreeBSD$
38  */
39 #ifndef _ATH_RATECTRL_H_
40 #define _ATH_RATECTRL_H_
41 
42 /*
43  * Interface definitions for transmit rate control modules for the
44  * Atheros driver.
45  *
46  * A rate control module is responsible for choosing the transmit rate
47  * for each data frame.  Management+control frames are always sent at
48  * a fixed rate.
49  *
50  * Only one module may be present at a time; the driver references
51  * rate control interfaces by symbol name.  If multiple modules are
52  * to be supported we'll need to switch to a registration-based scheme
53  * as is currently done, for example, for authentication modules.
54  *
55  * An instance of the rate control module is attached to each device
56  * at attach time and detached when the device is destroyed.  The module
57  * may associate data with each device and each node (station).  Both
58  * sets of storage are opaque except for the size of the per-node storage
59  * which must be provided when the module is attached.
60  *
61  * The rate control module is notified for each state transition and
62  * station association/reassociation.  Otherwise it is queried for a
63  * rate for each outgoing frame and provided status from each transmitted
64  * frame.  Any ancillary processing is the responsibility of the module
65  * (e.g. if periodic processing is required then the module should setup
66  * it's own timer).
67  *
68  * In addition to the transmit rate for each frame the module must also
69  * indicate the number of attempts to make at the specified rate.  If this
70  * number is != ATH_TXMAXTRY then an additional callback is made to setup
71  * additional transmit state.  The rate control code is assumed to write
72  * this additional data directly to the transmit descriptor.
73  */
74 struct ath_softc;
75 struct ath_node;
76 struct ath_desc;
77 
78 struct ath_ratectrl {
79 	size_t	arc_space;	/* space required for per-node state */
80 };
81 /*
82  * Attach/detach a rate control module.
83  */
84 struct ath_ratectrl *ath_rate_attach(struct ath_softc *);
85 void	ath_rate_detach(struct ath_ratectrl *);
86 
87 
88 /*
89  * State storage handling.
90  */
91 /*
92  * Initialize per-node state already allocated for the specified
93  * node; this space can be assumed initialized to zero.
94  */
95 void	ath_rate_node_init(struct ath_softc *, struct ath_node *);
96 /*
97  * Cleanup any per-node state prior to the node being reclaimed.
98  */
99 void	ath_rate_node_cleanup(struct ath_softc *, struct ath_node *);
100 /*
101  * Update rate control state on station associate/reassociate
102  * (when operating as an ap or for nodes discovered when operating
103  * in ibss mode).
104  */
105 void	ath_rate_newassoc(struct ath_softc *, struct ath_node *,
106 		int isNewAssociation);
107 /*
108  * Update/reset rate control state for 802.11 state transitions.
109  * Important mostly as the analog to ath_rate_newassoc when operating
110  * in station mode.
111  */
112 void	ath_rate_newstate(struct ath_softc *, enum ieee80211_state);
113 
114 /*
115  * Transmit handling.
116  */
117 /*
118  * Return the transmit info for a data packet.  If multi-rate state
119  * is to be setup then try0 should contain a value other than ATH_TXMATRY
120  * and ath_rate_setupxtxdesc will be called after deciding if the frame
121  * can be transmitted with multi-rate retry.
122  */
123 void	ath_rate_findrate(struct ath_softc *, struct ath_node *,
124 		int shortPreamble, size_t frameLen,
125 		u_int8_t *rix, int *try0, u_int8_t *txrate);
126 /*
127  * Setup any extended (multi-rate) descriptor state for a data packet.
128  * The rate index returned by ath_rate_findrate is passed back in.
129  */
130 void	ath_rate_setupxtxdesc(struct ath_softc *, struct ath_node *,
131 		struct ath_desc *, int shortPreamble, u_int8_t rix);
132 /*
133  * Update rate control state for a packet associated with the
134  * supplied transmit descriptor.  The routine is invoked both
135  * for packets that were successfully sent and for those that
136  * failed (consult the descriptor for details).
137  */
138 struct ath_buf;
139 void	ath_rate_tx_complete(struct ath_softc *, struct ath_node *,
140 		const struct ath_buf *);
141 #endif /* _ATH_RATECTRL_H_ */
142