xref: /freebsd/sys/dev/ath/if_athrate.h (revision 7ef62cebc2f965b0f640263e179276928885e33d)
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  * $FreeBSD$
33  */
34 #ifndef _ATH_RATECTRL_H_
35 #define _ATH_RATECTRL_H_
36 
37 /*
38  * Interface definitions for transmit rate control modules for the
39  * Atheros driver.
40  *
41  * A rate control module is responsible for choosing the transmit rate
42  * for each data frame.  Management+control frames are always sent at
43  * a fixed rate.
44  *
45  * Only one module may be present at a time; the driver references
46  * rate control interfaces by symbol name.  If multiple modules are
47  * to be supported we'll need to switch to a registration-based scheme
48  * as is currently done, for example, for authentication modules.
49  *
50  * An instance of the rate control module is attached to each device
51  * at attach time and detached when the device is destroyed.  The module
52  * may associate data with each device and each node (station).  Both
53  * sets of storage are opaque except for the size of the per-node storage
54  * which must be provided when the module is attached.
55  *
56  * The rate control module is notified for each state transition and
57  * station association/reassociation.  Otherwise it is queried for a
58  * rate for each outgoing frame and provided status from each transmitted
59  * frame.  Any ancillary processing is the responsibility of the module
60  * (e.g. if periodic processing is required then the module should setup
61  * it's own timer).
62  *
63  * In addition to the transmit rate for each frame the module must also
64  * indicate the number of attempts to make at the specified rate.  If this
65  * number is != ATH_TXMAXTRY then an additional callback is made to setup
66  * additional transmit state.  The rate control code is assumed to write
67  * this additional data directly to the transmit descriptor.
68  */
69 struct ath_softc;
70 struct ath_node;
71 struct ath_desc;
72 
73 struct ath_ratectrl {
74 	size_t	arc_space;	/* space required for per-node state */
75 };
76 /*
77  * Attach/detach a rate control module.
78  */
79 struct ath_ratectrl *ath_rate_attach(struct ath_softc *);
80 void	ath_rate_detach(struct ath_ratectrl *);
81 
82 #define	ATH_RC_NUM		4
83 
84 #define	ATH_RC_DS_FLAG		0x01	/* dual-stream rate */
85 #define	ATH_RC_CW40_FLAG	0x02	/* use HT40 */
86 #define	ATH_RC_SGI_FLAG		0x04	/* use short-GI */
87 #define	ATH_RC_HT_FLAG		0x08	/* use HT */
88 #define	ATH_RC_RTSCTS_FLAG	0x10	/* enable RTS/CTS protection */
89 #define	ATH_RC_STBC_FLAG	0x20	/* enable STBC */
90 #define	ATH_RC_TS_FLAG		0x40	/* triple-stream rate */
91 
92 struct ath_rc_series {
93 	uint8_t rix;		/* ratetable index, not rate code */
94 	uint8_t ratecode;	/* hardware rate code */
95 	uint8_t tries;
96 	uint8_t tx_power_cap;
97 	uint16_t flags;
98 	uint16_t max4msframelen;
99 };
100 
101 /*
102  * State storage handling.
103  */
104 /*
105  * Initialize per-node state already allocated for the specified
106  * node; this space can be assumed initialized to zero.
107  */
108 void	ath_rate_node_init(struct ath_softc *, struct ath_node *);
109 /*
110  * Cleanup any per-node state prior to the node being reclaimed.
111  */
112 void	ath_rate_node_cleanup(struct ath_softc *, struct ath_node *);
113 /*
114  * Update rate control state on station associate/reassociate
115  * (when operating as an ap or for nodes discovered when operating
116  * in ibss mode).
117  */
118 void	ath_rate_newassoc(struct ath_softc *, struct ath_node *,
119 		int isNewAssociation);
120 
121 /*
122  * Transmit handling.
123  */
124 /*
125  * Return the four TX rate index and try counts for the current data packet.
126  */
127 void	ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
128 		uint8_t rix0, int is_aggr, struct ath_rc_series *rc);
129 
130 /*
131  * Return the transmit info for a data packet.  If multi-rate state
132  * is to be setup then try0 should contain a value other than ATH_TXMATRY
133  * and ath_rate_setupxtxdesc will be called after deciding if the frame
134  * can be transmitted with multi-rate retry.
135  *
136  * maxdur is an optional return value (or -1 if not set) that defines
137  * the maximum frame duration in microseconds.  This allows the rate
138  * control selection to override the maximum duration (normally 4ms)
139  * that the packet aggregation logic makes.
140  */
141 void	ath_rate_findrate(struct ath_softc *, struct ath_node *,
142 		int shortPreamble, size_t frameLen, int tid, int is_aggr,
143 		u_int8_t *rix, int *try0, u_int8_t *txrate, int *maxdur,
144 		int *maxpktlen);
145 /*
146  * Setup any extended (multi-rate) descriptor state for a data packet.
147  * The rate index returned by ath_rate_findrate is passed back in.
148  */
149 void	ath_rate_setupxtxdesc(struct ath_softc *, struct ath_node *,
150 		struct ath_desc *, int shortPreamble, u_int8_t rix);
151 /*
152  * Update rate control state for a packet associated with the
153  * supplied transmit descriptor.  The routine is invoked both
154  * for packets that were successfully sent and for those that
155  * failed (consult the descriptor for details).
156  *
157  * For A-MPDU frames, nframes and nbad indicate how many frames
158  * were in the aggregate, and how many failed.
159  */
160 struct ath_buf;
161 void	ath_rate_tx_complete(struct ath_softc *, struct ath_node *,
162 		const struct ath_rc_series *, const struct ath_tx_status *,
163 		int pktlen, int rc_framelen, int nframes, int nbad);
164 
165 /*
166  * Update rate control with a per-packet receive RSSI value.
167  */
168 void	ath_rate_update_rx_rssi(struct ath_softc *, struct ath_node *,
169 		int rssi);
170 
171 /*
172  * Fetch the global rate control statistics.
173  */
174 int	ath_rate_fetch_stats(struct ath_softc *sc, struct ath_rateioctl *rs);
175 
176 /*
177  * Fetch the per-node statistics.
178  */
179 int	ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
180 		struct ath_rateioctl *rs);
181 
182 #endif /* _ATH_RATECTRL_H_ */
183