2 * Copyright (c) 2009 Atheros Communications Inc.
4 * Modified for iPXE by Scott K Logan <logans@cottsay.net> July 2011
5 * Original from Linux kernel 3.0.1
7 * Permission to use, copy, modify, and/or distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
25 #define REG_READ (common->ops->read)
26 #define REG_WRITE (common->ops->write)
29 * ath_hw_set_bssid_mask - filter out bssids we listen
31 * @common: the ath_common struct for the device.
33 * BSSID masking is a method used by AR5212 and newer hardware to inform PCU
34 * which bits of the interface's MAC address should be looked at when trying
35 * to decide which packets to ACK. In station mode and AP mode with a single
36 * BSS every bit matters since we lock to only one BSS. In AP mode with
37 * multiple BSSes (virtual interfaces) not every bit matters because hw must
38 * accept frames for all BSSes and so we tweak some bits of our mac address
39 * in order to have multiple BSSes.
41 * NOTE: This is a simple filter and does *not* filter out all
42 * relevant frames. Some frames that are not for us might get ACKed from us
43 * by PCU because they just match the mask.
45 * When handling multiple BSSes you can get the BSSID mask by computing the
46 * set of ~ ( MAC XOR BSSID ) for all bssids we handle.
48 * When you do this you are essentially computing the common bits of all your
49 * BSSes. Later it is assumed the hardware will "and" (&) the BSSID mask with
50 * the MAC address to obtain the relevant bits and compare the result with
51 * (frame's BSSID & mask) to see if they match.
53 * Simple example: on your card you have have two BSSes you have created with
54 * BSSID-01 and BSSID-02. Lets assume BSSID-01 will not use the MAC address.
55 * There is another BSSID-03 but you are not part of it. For simplicity's sake,
56 * assuming only 4 bits for a mac address and for BSSIDs you can then have:
60 * BSSID-01: 0100 | --> Belongs to us
64 * BSSID-03: 0110 | --> External
67 * Our bssid_mask would then be:
69 * On loop iteration for BSSID-01:
70 * ~(0001 ^ 0100) -> ~(0101)
74 * On loop iteration for BSSID-02:
75 * bssid_mask &= ~(0001 ^ 1001)
76 * bssid_mask = (1010) & ~(0001 ^ 1001)
77 * bssid_mask = (1010) & ~(1000)
78 * bssid_mask = (1010) & (0111)
81 * A bssid_mask of 0010 means "only pay attention to the second least
82 * significant bit". This is because its the only bit common
83 * amongst the MAC and all BSSIDs we support. To findout what the real
84 * common bit is we can simply "&" the bssid_mask now with any BSSID we have
85 * or our MAC address (we assume the hardware uses the MAC address).
87 * Now, suppose there's an incoming frame for BSSID-03:
91 * An easy eye-inspeciton of this already should tell you that this frame
92 * will not pass our check. This is because the bssid_mask tells the
93 * hardware to only look at the second least significant bit and the
94 * common bit amongst the MAC and BSSIDs is 0, this frame has the 2nd LSB
95 * as 1, which does not match 0.
97 * So with IFRAME-01 we *assume* the hardware will do:
99 * allow = (IFRAME-01 & bssid_mask) == (bssid_mask & MAC) ? 1 : 0;
100 * --> allow = (0110 & 0010) == (0010 & 0001) ? 1 : 0;
101 * --> allow = (0010) == 0000 ? 1 : 0;
104 * Lets now test a frame that should work:
106 * IFRAME-02: 0001 (we should allow)
108 * allow = (IFRAME-02 & bssid_mask) == (bssid_mask & MAC) ? 1 : 0;
109 * --> allow = (0001 & 0010) == (0010 & 0001) ? 1 :0;
110 * --> allow = (0000) == (0000)
115 * IFRAME-03: 0100 --> allowed
116 * IFRAME-04: 1001 --> allowed
117 * IFRAME-05: 1101 --> allowed but its not for us!!!
120 void ath_hw_setbssidmask(struct ath_common *common)
122 void *ah = common->ah;
124 REG_WRITE(ah, get_unaligned_le32(common->bssidmask), AR_BSSMSKL);
125 REG_WRITE(ah, get_unaligned_le16(common->bssidmask + 4), AR_BSSMSKU);
130 * ath_hw_cycle_counters_update - common function to update cycle counters
132 * @common: the ath_common struct for the device.
134 * This function is used to update all cycle counters in one place.
135 * It has to be called while holding common->cc_lock!
137 void ath_hw_cycle_counters_update(struct ath_common *common)
139 u32 cycles, busy, rx, tx;
140 void *ah = common->ah;
143 REG_WRITE(ah, AR_MIBC_FMC, AR_MIBC);
146 cycles = REG_READ(ah, AR_CCCNT);
147 busy = REG_READ(ah, AR_RCCNT);
148 rx = REG_READ(ah, AR_RFCNT);
149 tx = REG_READ(ah, AR_TFCNT);
152 REG_WRITE(ah, 0, AR_CCCNT);
153 REG_WRITE(ah, 0, AR_RFCNT);
154 REG_WRITE(ah, 0, AR_RCCNT);
155 REG_WRITE(ah, 0, AR_TFCNT);
158 REG_WRITE(ah, 0, AR_MIBC);
160 /* update all cycle counters here */
161 common->cc_ani.cycles += cycles;
162 common->cc_ani.rx_busy += busy;
163 common->cc_ani.rx_frame += rx;
164 common->cc_ani.tx_frame += tx;
166 common->cc_survey.cycles += cycles;
167 common->cc_survey.rx_busy += busy;
168 common->cc_survey.rx_frame += rx;
169 common->cc_survey.tx_frame += tx;
172 int32_t ath_hw_get_listen_time(struct ath_common *common)
174 struct ath_cycle_counters *cc = &common->cc_ani;
177 listen_time = (cc->cycles - cc->rx_frame - cc->tx_frame) /
178 (common->clockrate * 1000);
180 memset(cc, 0, sizeof(*cc));