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Diffstat (limited to 'drivers/net/wireless/ath/ath5k/pcu.c')
-rw-r--r--drivers/net/wireless/ath/ath5k/pcu.c121
1 files changed, 7 insertions, 114 deletions
diff --git a/drivers/net/wireless/ath/ath5k/pcu.c b/drivers/net/wireless/ath/ath5k/pcu.c
index f03c06d583e6..9ac763875a98 100644
--- a/drivers/net/wireless/ath/ath5k/pcu.c
+++ b/drivers/net/wireless/ath/ath5k/pcu.c
@@ -290,10 +290,10 @@ void ath5k_hw_set_associd(struct ath5k_hw *ah, const u8 *bssid, u16 assoc_id)
290 */ 290 */
291 if (ah->ah_version == AR5K_AR5212) { 291 if (ah->ah_version == AR5K_AR5212) {
292 ath5k_hw_reg_write(ah, get_unaligned_le32(common->bssidmask), 292 ath5k_hw_reg_write(ah, get_unaligned_le32(common->bssidmask),
293 AR5K_BSS_IDM0); 293 AR_BSSMSKL);
294 ath5k_hw_reg_write(ah, 294 ath5k_hw_reg_write(ah,
295 get_unaligned_le16(common->curbssid + 4), 295 get_unaligned_le16(common->curbssid + 4),
296 AR5K_BSS_IDM1); 296 AR_BSSMSKU);
297 } 297 }
298 298
299 /* 299 /*
@@ -301,9 +301,9 @@ void ath5k_hw_set_associd(struct ath5k_hw *ah, const u8 *bssid, u16 assoc_id)
301 */ 301 */
302 low_id = get_unaligned_le32(bssid); 302 low_id = get_unaligned_le32(bssid);
303 high_id = get_unaligned_le16(bssid); 303 high_id = get_unaligned_le16(bssid);
304 ath5k_hw_reg_write(ah, low_id, AR5K_BSS_ID0); 304 ath5k_hw_reg_write(ah, low_id, AR_BSSMSKL);
305 ath5k_hw_reg_write(ah, high_id | ((assoc_id & 0x3fff) << 305 ath5k_hw_reg_write(ah, high_id | ((assoc_id & 0x3fff) <<
306 AR5K_BSS_ID1_AID_S), AR5K_BSS_ID1); 306 AR5K_BSS_ID1_AID_S), AR_BSSMSKU);
307 307
308 if (assoc_id == 0) { 308 if (assoc_id == 0) {
309 ath5k_hw_disable_pspoll(ah); 309 ath5k_hw_disable_pspoll(ah);
@@ -316,125 +316,18 @@ void ath5k_hw_set_associd(struct ath5k_hw *ah, const u8 *bssid, u16 assoc_id)
316 ath5k_hw_enable_pspoll(ah, NULL, 0); 316 ath5k_hw_enable_pspoll(ah, NULL, 0);
317} 317}
318 318
319/** 319void ath5k_hw_set_bssid_mask(struct ath5k_hw *ah, const u8 *mask)
320 * ath5k_hw_set_bssid_mask - filter out bssids we listen
321 *
322 * @ah: the &struct ath5k_hw
323 * @mask: the bssid_mask, a u8 array of size ETH_ALEN
324 *
325 * BSSID masking is a method used by AR5212 and newer hardware to inform PCU
326 * which bits of the interface's MAC address should be looked at when trying
327 * to decide which packets to ACK. In station mode and AP mode with a single
328 * BSS every bit matters since we lock to only one BSS. In AP mode with
329 * multiple BSSes (virtual interfaces) not every bit matters because hw must
330 * accept frames for all BSSes and so we tweak some bits of our mac address
331 * in order to have multiple BSSes.
332 *
333 * NOTE: This is a simple filter and does *not* filter out all
334 * relevant frames. Some frames that are not for us might get ACKed from us
335 * by PCU because they just match the mask.
336 *
337 * When handling multiple BSSes you can get the BSSID mask by computing the
338 * set of ~ ( MAC XOR BSSID ) for all bssids we handle.
339 *
340 * When you do this you are essentially computing the common bits of all your
341 * BSSes. Later it is assumed the harware will "and" (&) the BSSID mask with
342 * the MAC address to obtain the relevant bits and compare the result with
343 * (frame's BSSID & mask) to see if they match.
344 */
345/*
346 * Simple example: on your card you have have two BSSes you have created with
347 * BSSID-01 and BSSID-02. Lets assume BSSID-01 will not use the MAC address.
348 * There is another BSSID-03 but you are not part of it. For simplicity's sake,
349 * assuming only 4 bits for a mac address and for BSSIDs you can then have:
350 *
351 * \
352 * MAC: 0001 |
353 * BSSID-01: 0100 | --> Belongs to us
354 * BSSID-02: 1001 |
355 * /
356 * -------------------
357 * BSSID-03: 0110 | --> External
358 * -------------------
359 *
360 * Our bssid_mask would then be:
361 *
362 * On loop iteration for BSSID-01:
363 * ~(0001 ^ 0100) -> ~(0101)
364 * -> 1010
365 * bssid_mask = 1010
366 *
367 * On loop iteration for BSSID-02:
368 * bssid_mask &= ~(0001 ^ 1001)
369 * bssid_mask = (1010) & ~(0001 ^ 1001)
370 * bssid_mask = (1010) & ~(1001)
371 * bssid_mask = (1010) & (0110)
372 * bssid_mask = 0010
373 *
374 * A bssid_mask of 0010 means "only pay attention to the second least
375 * significant bit". This is because its the only bit common
376 * amongst the MAC and all BSSIDs we support. To findout what the real
377 * common bit is we can simply "&" the bssid_mask now with any BSSID we have
378 * or our MAC address (we assume the hardware uses the MAC address).
379 *
380 * Now, suppose there's an incoming frame for BSSID-03:
381 *
382 * IFRAME-01: 0110
383 *
384 * An easy eye-inspeciton of this already should tell you that this frame
385 * will not pass our check. This is beacuse the bssid_mask tells the
386 * hardware to only look at the second least significant bit and the
387 * common bit amongst the MAC and BSSIDs is 0, this frame has the 2nd LSB
388 * as 1, which does not match 0.
389 *
390 * So with IFRAME-01 we *assume* the hardware will do:
391 *
392 * allow = (IFRAME-01 & bssid_mask) == (bssid_mask & MAC) ? 1 : 0;
393 * --> allow = (0110 & 0010) == (0010 & 0001) ? 1 : 0;
394 * --> allow = (0010) == 0000 ? 1 : 0;
395 * --> allow = 0
396 *
397 * Lets now test a frame that should work:
398 *
399 * IFRAME-02: 0001 (we should allow)
400 *
401 * allow = (0001 & 1010) == 1010
402 *
403 * allow = (IFRAME-02 & bssid_mask) == (bssid_mask & MAC) ? 1 : 0;
404 * --> allow = (0001 & 0010) == (0010 & 0001) ? 1 :0;
405 * --> allow = (0010) == (0010)
406 * --> allow = 1
407 *
408 * Other examples:
409 *
410 * IFRAME-03: 0100 --> allowed
411 * IFRAME-04: 1001 --> allowed
412 * IFRAME-05: 1101 --> allowed but its not for us!!!
413 *
414 */
415int ath5k_hw_set_bssid_mask(struct ath5k_hw *ah, const u8 *mask)
416{ 320{
417 struct ath_common *common = ath5k_hw_common(ah); 321 struct ath_common *common = ath5k_hw_common(ah);
418 u32 low_id, high_id;
419 ATH5K_TRACE(ah->ah_sc); 322 ATH5K_TRACE(ah->ah_sc);
420 323
421 /* Cache bssid mask so that we can restore it 324 /* Cache bssid mask so that we can restore it
422 * on reset */ 325 * on reset */
423 memcpy(common->bssidmask, mask, ETH_ALEN); 326 memcpy(common->bssidmask, mask, ETH_ALEN);
424 if (ah->ah_version == AR5K_AR5212) { 327 if (ah->ah_version == AR5K_AR5212)
425 low_id = get_unaligned_le32(mask); 328 ath_hw_setbssidmask(common);
426 high_id = get_unaligned_le16(mask + 4);
427
428 ath5k_hw_reg_write(ah, low_id, AR5K_BSS_IDM0);
429 ath5k_hw_reg_write(ah, high_id, AR5K_BSS_IDM1);
430
431 return 0;
432 }
433
434 return -EIO;
435} 329}
436 330
437
438/************\ 331/************\
439* RX Control * 332* RX Control *
440\************/ 333\************/