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 */
67struct ath_softc;
68struct ath_node;
69struct ath_desc;
70
71struct ath_ratectrl {
72	size_t	arc_space;	/* space required for per-node state */
73};
74/*
75 * Attach/detach a rate control module.
76 */
77struct ath_ratectrl *ath_rate_attach(struct ath_softc *);
78void	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 */
88void	ath_rate_node_init(struct ath_softc *, struct ath_node *);
89/*
90 * Cleanup any per-node state prior to the node being reclaimed.
91 */
92void	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 */
98void	ath_rate_newassoc(struct ath_softc *, struct ath_node *,
99		int isNewAssociation);
100
101/*
102 * Transmit handling.
103 */
104/*
105 * Return the four TX rate index and try counts for the current data packet.
106 */
107void	ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
108		uint8_t rix0, uint8_t *rix, uint8_t *try);
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 */
116void	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 */
123void	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 */
131struct ath_buf;
132void	ath_rate_tx_complete(struct ath_softc *, struct ath_node *,
133		const struct ath_buf *);
134#endif /* _ATH_RATECTRL_H_ */
135