--- /dev/null
+/*
+ * 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_set_bssid_mask - 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 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(ath_hw_get_listen_time);
Code Review / kvmfornfv.git / blobdiff