xref: /freebsd/sys/net80211/ieee80211_phy.h (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2007-2008 Sam Leffler, Errno Consulting
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #ifndef _NET80211_IEEE80211_PHY_H_
29 #define _NET80211_IEEE80211_PHY_H_
30 
31 #ifdef _KERNEL
32 /*
33  * IEEE 802.11 PHY-related definitions.
34  */
35 
36 /*
37  * Contention window (slots).
38  */
39 #define IEEE80211_CW_MAX	1023	/* aCWmax */
40 #define IEEE80211_CW_MIN_0	31	/* DS/CCK aCWmin, ERP aCWmin(0) */
41 #define IEEE80211_CW_MIN_1	15	/* OFDM aCWmin, ERP aCWmin(1) */
42 
43 /*
44  * SIFS (microseconds).
45  */
46 #define IEEE80211_DUR_SIFS	10	/* DS/CCK/ERP SIFS */
47 #define IEEE80211_DUR_OFDM_SIFS	16	/* OFDM SIFS */
48 
49 /*
50  * Slot time (microseconds).
51  */
52 #define IEEE80211_DUR_SLOT	20	/* DS/CCK slottime, ERP long slottime */
53 #define IEEE80211_DUR_SHSLOT	9	/* ERP short slottime */
54 #define IEEE80211_DUR_OFDM_SLOT	9	/* OFDM slottime */
55 
56 /*
57  * For drivers that don't implement per-VAP slot time
58  * (ie, they rely on net80211 figuring out the union
59  * between VAPs to program a single radio) - return
60  * the current radio configured slot time.
61  */
62 #define IEEE80211_GET_SLOTTIME(ic) \
63 	((ic->ic_flags & IEEE80211_F_SHSLOT) ? \
64 	    IEEE80211_DUR_SHSLOT : IEEE80211_DUR_SLOT)
65 
66 /*
67  * For drivers that implement per-VAP slot time; look
68  * at the per-VAP flags to determine whether this VAP
69  * is in short or long slot time.
70  */
71 #define IEEE80211_VAP_GET_SLOTTIME(vap) \
72 	((vap->iv_flags & IEEE80211_F_SHSLOT) ? \
73 	    IEEE80211_DUR_SHSLOT : IEEE80211_DUR_SLOT)
74 
75 /*
76  * DIFS (microseconds).
77  */
78 #define IEEE80211_DUR_DIFS(sifs, slot)	((sifs) + 2 * (slot))
79 
80 struct ieee80211_channel;
81 
82 #define	IEEE80211_RATE_TABLE_SIZE	128
83 
84 struct ieee80211_rate_table {
85 	int		rateCount;		/* NB: for proper padding */
86 	uint8_t		rateCodeToIndex[256];	/* back mapping */
87 	struct {
88 		uint8_t		phy;		/* CCK/OFDM/TURBO */
89 		uint32_t	rateKbps;	/* transfer rate in kbs */
90 		uint8_t		shortPreamble;	/* mask for enabling short
91 						 * preamble in CCK rate code */
92 		uint8_t		dot11Rate;	/* value for supported rates
93 						 * info element of MLME */
94 		uint8_t		ctlRateIndex;	/* index of next lower basic
95 						 * rate; used for dur. calcs */
96 		uint16_t	lpAckDuration;	/* long preamble ACK dur. */
97 		uint16_t	spAckDuration;	/* short preamble ACK dur. */
98 	} info[IEEE80211_RATE_TABLE_SIZE];
99 };
100 
101 const struct ieee80211_rate_table *ieee80211_get_ratetable(
102 			struct ieee80211_channel *);
103 
104 static __inline__ uint8_t
105 ieee80211_ack_rate(const struct ieee80211_rate_table *rt, uint8_t rate)
106 {
107 	/*
108 	 * XXX Assert this is for a legacy rate; not for an MCS rate.
109 	 * If the caller wishes to use it for a basic rate, they should
110 	 * clear the high bit first.
111 	 */
112 	KASSERT(! (rate & 0x80), ("rate %d is basic/mcs?", rate));
113 
114 	uint8_t cix = rt->info[rt->rateCodeToIndex[rate & IEEE80211_RATE_VAL]].ctlRateIndex;
115 	KASSERT(cix != (uint8_t)-1, ("rate %d has no info", rate));
116 	return rt->info[cix].dot11Rate;
117 }
118 
119 static __inline__ uint8_t
120 ieee80211_ctl_rate(const struct ieee80211_rate_table *rt, uint8_t rate)
121 {
122 	/*
123 	 * XXX Assert this is for a legacy rate; not for an MCS rate.
124 	 * If the caller wishes to use it for a basic rate, they should
125 	 * clear the high bit first.
126 	 */
127 	KASSERT(! (rate & 0x80), ("rate %d is basic/mcs?", rate));
128 
129 	uint8_t cix = rt->info[rt->rateCodeToIndex[rate & IEEE80211_RATE_VAL]].ctlRateIndex;
130 	KASSERT(cix != (uint8_t)-1, ("rate %d has no info", rate));
131 	return rt->info[cix].dot11Rate;
132 }
133 
134 static __inline__ enum ieee80211_phytype
135 ieee80211_rate2phytype(const struct ieee80211_rate_table *rt, uint8_t rate)
136 {
137 	/*
138 	 * XXX Assert this is for a legacy rate; not for an MCS rate.
139 	 * If the caller wishes to use it for a basic rate, they should
140 	 * clear the high bit first.
141 	 */
142 	KASSERT(! (rate & 0x80), ("rate %d is basic/mcs?", rate));
143 
144 	uint8_t rix = rt->rateCodeToIndex[rate & IEEE80211_RATE_VAL];
145 	KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate));
146 	return rt->info[rix].phy;
147 }
148 
149 static __inline__ int
150 ieee80211_isratevalid(const struct ieee80211_rate_table *rt, uint8_t rate)
151 {
152 	/*
153 	 * XXX Assert this is for a legacy rate; not for an MCS rate.
154 	 * If the caller wishes to use it for a basic rate, they should
155 	 * clear the high bit first.
156 	 */
157 	KASSERT(! (rate & 0x80), ("rate %d is basic/mcs?", rate));
158 
159 	return rt->rateCodeToIndex[rate] != (uint8_t)-1;
160 }
161 
162 /*
163  * Calculate ACK field for
164  * o  non-fragment data frames
165  * o  management frames
166  * sent using rate, phy and short preamble setting.
167  */
168 static __inline__ uint16_t
169 ieee80211_ack_duration(const struct ieee80211_rate_table *rt,
170     uint8_t rate, int isShortPreamble)
171 {
172 	uint8_t rix = rt->rateCodeToIndex[rate];
173 
174 	KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate));
175 	if (isShortPreamble) {
176 		KASSERT(rt->info[rix].spAckDuration != 0,
177 			("shpreamble ack dur is not computed!\n"));
178 		return rt->info[rix].spAckDuration;
179 	} else {
180 		KASSERT(rt->info[rix].lpAckDuration != 0,
181 			("lgpreamble ack dur is not computed!\n"));
182 		return rt->info[rix].lpAckDuration;
183 	}
184 }
185 
186 static __inline__ uint8_t
187 ieee80211_legacy_rate_lookup(const struct ieee80211_rate_table *rt,
188     uint8_t rate)
189 {
190 
191 	return (rt->rateCodeToIndex[rate & IEEE80211_RATE_VAL]);
192 }
193 
194 /*
195  * Compute the time to transmit a frame of length frameLen bytes
196  * using the specified 802.11 rate code, phy, and short preamble
197  * setting.
198  *
199  * NB: SIFS is included.
200  */
201 uint16_t	ieee80211_compute_duration(const struct ieee80211_rate_table *,
202 			uint32_t frameLen, uint16_t rate, int isShortPreamble);
203 /*
204  * Convert PLCP signal/rate field to 802.11 rate code (.5Mbits/s)
205  */
206 uint8_t		ieee80211_plcp2rate(uint8_t, enum ieee80211_phytype);
207 /*
208  * Convert 802.11 rate code to PLCP signal.
209  */
210 uint8_t		ieee80211_rate2plcp(int, enum ieee80211_phytype);
211 
212 /*
213  * 802.11n rate manipulation.
214  */
215 
216 #define	IEEE80211_HT_RC_2_MCS(_rc)	((_rc) & 0x1f)
217 #define	IEEE80211_HT_RC_2_STREAMS(_rc)	((((_rc) & 0x78) >> 3) + 1)
218 #define	IEEE80211_IS_HT_RATE(_rc)		( (_rc) & IEEE80211_RATE_MCS)
219 
220 uint32_t	ieee80211_compute_duration_ht(uint32_t frameLen,
221 			uint16_t rate, int streams, int isht40,
222 			int isShortGI);
223 
224 #endif	/* _KERNEL */
225 #endif	/* !_NET80211_IEEE80211_PHY_H_ */
226