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atheros: define shared bssidmask setting

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Also make ath5k and ath9k use it, and share register definitions.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Luis R. Rodriguez
2009-09-10 17:52:45 -07:00
committed by John W. Linville
parent e5aa847489
commit 13b8155920
15 changed files with 179 additions and 140 deletions
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121
drivers/net/wireless/ath/ath5k/pcu.c
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@@ -290,10 +290,10 @@ void ath5k_hw_set_associd(struct ath5k_hw *ah, const u8 *bssid, u16 assoc_id)
*/
if (ah->ah_version == AR5K_AR5212) {
ath5k_hw_reg_write(ah, get_unaligned_le32(common->bssidmask),
AR5K_BSS_IDM0);
AR_BSSMSKL);
ath5k_hw_reg_write(ah,
get_unaligned_le16(common->curbssid + 4),
AR5K_BSS_IDM1);
AR_BSSMSKU);
}
/*
@@ -301,9 +301,9 @@ void ath5k_hw_set_associd(struct ath5k_hw *ah, const u8 *bssid, u16 assoc_id)
*/
low_id = get_unaligned_le32(bssid);
high_id = get_unaligned_le16(bssid);
ath5k_hw_reg_write(ah, low_id, AR5K_BSS_ID0);
ath5k_hw_reg_write(ah, low_id, AR_BSSMSKL);
ath5k_hw_reg_write(ah, high_id | ((assoc_id & 0x3fff) <<
AR5K_BSS_ID1_AID_S), AR5K_BSS_ID1);
AR5K_BSS_ID1_AID_S), AR_BSSMSKU);
if (assoc_id == 0) {
ath5k_hw_disable_pspoll(ah);
@@ -316,125 +316,18 @@ void ath5k_hw_set_associd(struct ath5k_hw *ah, const u8 *bssid, u16 assoc_id)
ath5k_hw_enable_pspoll(ah, NULL, 0);
}
/**
* ath5k_hw_set_bssid_mask - filter out bssids we listen
*
* @ah: the &struct ath5k_hw
* @mask: the bssid_mask, a u8 array of size ETH_ALEN
*
* 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 harware 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) & ~(1001)
* bssid_mask = (1010) & (0110)
* 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 beacuse 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 = (0001 & 1010) == 1010
*
* allow = (IFRAME-02 & bssid_mask) == (bssid_mask & MAC) ? 1 : 0;
* --> allow = (0001 & 0010) == (0010 & 0001) ? 1 :0;
* --> allow = (0010) == (0010)
* --> allow = 1
*
* Other examples:
*
* IFRAME-03: 0100 --> allowed
* IFRAME-04: 1001 --> allowed
* IFRAME-05: 1101 --> allowed but its not for us!!!
*
*/
int ath5k_hw_set_bssid_mask(struct ath5k_hw *ah, const u8 *mask)
void ath5k_hw_set_bssid_mask(struct ath5k_hw *ah, const u8 *mask)
{
struct ath_common *common = ath5k_hw_common(ah);
u32 low_id, high_id;
ATH5K_TRACE(ah->ah_sc);
/* Cache bssid mask so that we can restore it
* on reset */
memcpy(common->bssidmask, mask, ETH_ALEN);
if (ah->ah_version == AR5K_AR5212) {
low_id = get_unaligned_le32(mask);
high_id = get_unaligned_le16(mask + 4);
ath5k_hw_reg_write(ah, low_id, AR5K_BSS_IDM0);
ath5k_hw_reg_write(ah, high_id, AR5K_BSS_IDM1);
return 0;
}
return -EIO;
if (ah->ah_version == AR5K_AR5212)
ath_hw_setbssidmask(common);
}
/************\
* RX Control *
\************/