1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2004-2008 Sam Leffler, Errno Consulting
5 * Copyright (c) 2004 Video54 Technologies, Inc.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer,
13 *    without modification.
14 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
15 *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
16 *    redistribution must be conditioned upon including a substantially
17 *    similar Disclaimer requirement for further binary redistribution.
18 *
19 * NO WARRANTY
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
23 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
24 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
25 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
28 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
30 * THE POSSIBILITY OF SUCH DAMAGES.
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#define	ATH_RC_NUM		4
81
82#define	ATH_RC_DS_FLAG		0x01	/* dual-stream rate */
83#define	ATH_RC_CW40_FLAG	0x02	/* use HT40 */
84#define	ATH_RC_SGI_FLAG		0x04	/* use short-GI */
85#define	ATH_RC_HT_FLAG		0x08	/* use HT */
86#define	ATH_RC_RTSCTS_FLAG	0x10	/* enable RTS/CTS protection */
87#define	ATH_RC_STBC_FLAG	0x20	/* enable STBC */
88#define	ATH_RC_TS_FLAG		0x40	/* triple-stream rate */
89
90struct ath_rc_series {
91	uint8_t rix;		/* ratetable index, not rate code */
92	uint8_t ratecode;	/* hardware rate code */
93	uint8_t tries;
94	uint8_t tx_power_cap;
95	uint16_t flags;
96	uint16_t max4msframelen;
97};
98
99/*
100 * State storage handling.
101 */
102/*
103 * Initialize per-node state already allocated for the specified
104 * node; this space can be assumed initialized to zero.
105 */
106void	ath_rate_node_init(struct ath_softc *, struct ath_node *);
107/*
108 * Cleanup any per-node state prior to the node being reclaimed.
109 */
110void	ath_rate_node_cleanup(struct ath_softc *, struct ath_node *);
111/*
112 * Update rate control state on station associate/reassociate
113 * (when operating as an ap or for nodes discovered when operating
114 * in ibss mode).
115 */
116void	ath_rate_newassoc(struct ath_softc *, struct ath_node *,
117		int isNewAssociation);
118
119/*
120 * Transmit handling.
121 */
122/*
123 * Return the four TX rate index and try counts for the current data packet.
124 */
125void	ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
126		uint8_t rix0, int is_aggr, struct ath_rc_series *rc);
127
128/*
129 * Return the transmit info for a data packet.  If multi-rate state
130 * is to be setup then try0 should contain a value other than ATH_TXMATRY
131 * and ath_rate_setupxtxdesc will be called after deciding if the frame
132 * can be transmitted with multi-rate retry.
133 *
134 * maxdur is an optional return value (or -1 if not set) that defines
135 * the maximum frame duration in microseconds.  This allows the rate
136 * control selection to override the maximum duration (normally 4ms)
137 * that the packet aggregation logic makes.
138 */
139void	ath_rate_findrate(struct ath_softc *, struct ath_node *,
140		int shortPreamble, size_t frameLen, int tid, int is_aggr,
141		u_int8_t *rix, int *try0, u_int8_t *txrate, int *maxdur,
142		int *maxpktlen);
143/*
144 * Setup any extended (multi-rate) descriptor state for a data packet.
145 * The rate index returned by ath_rate_findrate is passed back in.
146 */
147void	ath_rate_setupxtxdesc(struct ath_softc *, struct ath_node *,
148		struct ath_desc *, int shortPreamble, u_int8_t rix);
149/*
150 * Update rate control state for a packet associated with the
151 * supplied transmit descriptor.  The routine is invoked both
152 * for packets that were successfully sent and for those that
153 * failed (consult the descriptor for details).
154 *
155 * For A-MPDU frames, nframes and nbad indicate how many frames
156 * were in the aggregate, and how many failed.
157 */
158struct ath_buf;
159void	ath_rate_tx_complete(struct ath_softc *, struct ath_node *,
160		const struct ath_rc_series *, const struct ath_tx_status *,
161		int pktlen, int rc_framelen, int nframes, int nbad);
162
163/*
164 * Update rate control with a per-packet receive RSSI value.
165 */
166void	ath_rate_update_rx_rssi(struct ath_softc *, struct ath_node *,
167		int rssi);
168
169/*
170 * Fetch the global rate control statistics.
171 */
172int	ath_rate_fetch_stats(struct ath_softc *sc, struct ath_rateioctl *rs);
173
174/*
175 * Fetch the per-node statistics.
176 */
177int	ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
178		struct ath_rateioctl *rs);
179
180#endif /* _ATH_RATECTRL_H_ */
181