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