 ecbbed32e7
			
		
	
	
	ecbbed32e7
	
	
	
		
			
			Preparation for updating common->macaddr along with virtual interface MAC address changes. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
		
			
				
	
	
		
			190 lines
		
	
	
	
		
			6.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			190 lines
		
	
	
	
		
			6.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2009 Atheros Communications Inc.
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|  *
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|  * Permission to use, copy, modify, and/or distribute this software for any
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|  * purpose with or without fee is hereby granted, provided that the above
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|  * copyright notice and this permission notice appear in all copies.
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|  *
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|  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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|  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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|  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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|  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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|  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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|  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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|  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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|  */
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| 
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| #include <linux/export.h>
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| #include <asm/unaligned.h>
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| 
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| #include "ath.h"
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| #include "reg.h"
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| 
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| #define REG_READ			(common->ops->read)
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| #define REG_WRITE(_ah, _reg, _val)	(common->ops->write)(_ah, _val, _reg)
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| 
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| /**
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|  * ath_hw_set_bssid_mask - filter out bssids we listen
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|  *
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|  * @common: the ath_common struct for the device.
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|  *
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|  * BSSID masking is a method used by AR5212 and newer hardware to inform PCU
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|  * which bits of the interface's MAC address should be looked at when trying
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|  * to decide which packets to ACK. In station mode and AP mode with a single
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|  * BSS every bit matters since we lock to only one BSS. In AP mode with
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|  * multiple BSSes (virtual interfaces) not every bit matters because hw must
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|  * accept frames for all BSSes and so we tweak some bits of our mac address
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|  * in order to have multiple BSSes.
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|  *
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|  * NOTE: This is a simple filter and does *not* filter out all
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|  * relevant frames. Some frames that are not for us might get ACKed from us
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|  * by PCU because they just match the mask.
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|  *
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|  * When handling multiple BSSes you can get the BSSID mask by computing the
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|  * set of  ~ ( MAC XOR BSSID ) for all bssids we handle.
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|  *
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|  * When you do this you are essentially computing the common bits of all your
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|  * BSSes. Later it is assumed the hardware will "and" (&) the BSSID mask with
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|  * the MAC address to obtain the relevant bits and compare the result with
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|  * (frame's BSSID & mask) to see if they match.
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|  *
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|  * Simple example: on your card you have have two BSSes you have created with
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|  * BSSID-01 and BSSID-02. Lets assume BSSID-01 will not use the MAC address.
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|  * There is another BSSID-03 but you are not part of it. For simplicity's sake,
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|  * assuming only 4 bits for a mac address and for BSSIDs you can then have:
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|  *
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|  *                  \
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|  * MAC:        0001 |
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|  * BSSID-01:   0100 | --> Belongs to us
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|  * BSSID-02:   1001 |
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|  *                  /
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|  * -------------------
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|  * BSSID-03:   0110  | --> External
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|  * -------------------
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|  *
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|  * Our bssid_mask would then be:
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|  *
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|  *             On loop iteration for BSSID-01:
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|  *             ~(0001 ^ 0100)  -> ~(0101)
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|  *                             ->   1010
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|  *             bssid_mask      =    1010
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|  *
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|  *             On loop iteration for BSSID-02:
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|  *             bssid_mask &= ~(0001   ^   1001)
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|  *             bssid_mask =   (1010)  & ~(0001 ^ 1001)
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|  *             bssid_mask =   (1010)  & ~(1000)
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|  *             bssid_mask =   (1010)  &  (0111)
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|  *             bssid_mask =   0010
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|  *
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|  * A bssid_mask of 0010 means "only pay attention to the second least
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|  * significant bit". This is because its the only bit common
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|  * amongst the MAC and all BSSIDs we support. To findout what the real
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|  * common bit is we can simply "&" the bssid_mask now with any BSSID we have
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|  * or our MAC address (we assume the hardware uses the MAC address).
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|  *
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|  * Now, suppose there's an incoming frame for BSSID-03:
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|  *
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|  * IFRAME-01:  0110
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|  *
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|  * An easy eye-inspeciton of this already should tell you that this frame
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|  * will not pass our check. This is because the bssid_mask tells the
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|  * hardware to only look at the second least significant bit and the
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|  * common bit amongst the MAC and BSSIDs is 0, this frame has the 2nd LSB
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|  * as 1, which does not match 0.
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|  *
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|  * So with IFRAME-01 we *assume* the hardware will do:
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|  *
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|  *     allow = (IFRAME-01 & bssid_mask) == (bssid_mask & MAC) ? 1 : 0;
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|  *  --> allow = (0110 & 0010) == (0010 & 0001) ? 1 : 0;
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|  *  --> allow = (0010) == 0000 ? 1 : 0;
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|  *  --> allow = 0
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|  *
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|  *  Lets now test a frame that should work:
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|  *
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|  * IFRAME-02:  0001 (we should allow)
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|  *
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|  *     allow = (IFRAME-02 & bssid_mask) == (bssid_mask & MAC) ? 1 : 0;
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|  *  --> allow = (0001 & 0010) ==  (0010 & 0001) ? 1 :0;
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|  *  --> allow = (0000) == (0000)
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|  *  --> allow = 1
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|  *
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|  * Other examples:
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|  *
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|  * IFRAME-03:  0100 --> allowed
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|  * IFRAME-04:  1001 --> allowed
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|  * IFRAME-05:  1101 --> allowed but its not for us!!!
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|  *
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|  */
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| void ath_hw_setbssidmask(struct ath_common *common)
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| {
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| 	void *ah = common->ah;
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| 	u32 id1;
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| 
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| 	REG_WRITE(ah, AR_STA_ID0, get_unaligned_le32(common->macaddr));
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| 	id1 = REG_READ(ah, AR_STA_ID1) & ~AR_STA_ID1_SADH_MASK;
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| 	id1 |= get_unaligned_le16(common->macaddr + 4);
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| 	REG_WRITE(ah, AR_STA_ID1, id1);
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| 
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| 	REG_WRITE(ah, AR_BSSMSKL, get_unaligned_le32(common->bssidmask));
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| 	REG_WRITE(ah, AR_BSSMSKU, get_unaligned_le16(common->bssidmask + 4));
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| }
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| EXPORT_SYMBOL(ath_hw_setbssidmask);
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| 
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| 
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| /**
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|  * ath_hw_cycle_counters_update - common function to update cycle counters
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|  *
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|  * @common: the ath_common struct for the device.
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|  *
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|  * This function is used to update all cycle counters in one place.
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|  * It has to be called while holding common->cc_lock!
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|  */
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| void ath_hw_cycle_counters_update(struct ath_common *common)
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| {
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| 	u32 cycles, busy, rx, tx;
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| 	void *ah = common->ah;
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| 
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| 	/* freeze */
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| 	REG_WRITE(ah, AR_MIBC, AR_MIBC_FMC);
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| 
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| 	/* read */
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| 	cycles = REG_READ(ah, AR_CCCNT);
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| 	busy = REG_READ(ah, AR_RCCNT);
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| 	rx = REG_READ(ah, AR_RFCNT);
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| 	tx = REG_READ(ah, AR_TFCNT);
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| 
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| 	/* clear */
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| 	REG_WRITE(ah, AR_CCCNT, 0);
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| 	REG_WRITE(ah, AR_RFCNT, 0);
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| 	REG_WRITE(ah, AR_RCCNT, 0);
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| 	REG_WRITE(ah, AR_TFCNT, 0);
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| 
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| 	/* unfreeze */
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| 	REG_WRITE(ah, AR_MIBC, 0);
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| 
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| 	/* update all cycle counters here */
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| 	common->cc_ani.cycles += cycles;
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| 	common->cc_ani.rx_busy += busy;
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| 	common->cc_ani.rx_frame += rx;
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| 	common->cc_ani.tx_frame += tx;
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| 
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| 	common->cc_survey.cycles += cycles;
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| 	common->cc_survey.rx_busy += busy;
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| 	common->cc_survey.rx_frame += rx;
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| 	common->cc_survey.tx_frame += tx;
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| }
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| EXPORT_SYMBOL(ath_hw_cycle_counters_update);
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| 
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| int32_t ath_hw_get_listen_time(struct ath_common *common)
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| {
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| 	struct ath_cycle_counters *cc = &common->cc_ani;
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| 	int32_t listen_time;
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| 
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| 	listen_time = (cc->cycles - cc->rx_frame - cc->tx_frame) /
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| 		      (common->clockrate * 1000);
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| 
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| 	memset(cc, 0, sizeof(*cc));
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| 
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| 	return listen_time;
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| }
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| EXPORT_SYMBOL(ath_hw_get_listen_time);
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