summaryrefslogtreecommitdiff
path: root/net/mac80211/sta_info.c
blob: b6cfcf038c11fa529e00da2eed70f6ff48426a37 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2013-2014  Intel Mobile Communications GmbH
 * Copyright (C) 2015 - 2016 Intel Deutschland GmbH
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/etherdevice.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/timer.h>
#include <linux/rtnetlink.h>

#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
#include "rate.h"
#include "sta_info.h"
#include "debugfs_sta.h"
#include "mesh.h"
#include "wme.h"

/**
 * DOC: STA information lifetime rules
 *
 * STA info structures (&struct sta_info) are managed in a hash table
 * for faster lookup and a list for iteration. They are managed using
 * RCU, i.e. access to the list and hash table is protected by RCU.
 *
 * Upon allocating a STA info structure with sta_info_alloc(), the caller
 * owns that structure. It must then insert it into the hash table using
 * either sta_info_insert() or sta_info_insert_rcu(); only in the latter
 * case (which acquires an rcu read section but must not be called from
 * within one) will the pointer still be valid after the call. Note that
 * the caller may not do much with the STA info before inserting it, in
 * particular, it may not start any mesh peer link management or add
 * encryption keys.
 *
 * When the insertion fails (sta_info_insert()) returns non-zero), the
 * structure will have been freed by sta_info_insert()!
 *
 * Station entries are added by mac80211 when you establish a link with a
 * peer. This means different things for the different type of interfaces
 * we support. For a regular station this mean we add the AP sta when we
 * receive an association response from the AP. For IBSS this occurs when
 * get to know about a peer on the same IBSS. For WDS we add the sta for
 * the peer immediately upon device open. When using AP mode we add stations
 * for each respective station upon request from userspace through nl80211.
 *
 * In order to remove a STA info structure, various sta_info_destroy_*()
 * calls are available.
 *
 * There is no concept of ownership on a STA entry, each structure is
 * owned by the global hash table/list until it is removed. All users of
 * the structure need to be RCU protected so that the structure won't be
 * freed before they are done using it.
 */

static const struct rhashtable_params sta_rht_params = {
	.nelem_hint = 3, /* start small */
	.automatic_shrinking = true,
	.head_offset = offsetof(struct sta_info, hash_node),
	.key_offset = offsetof(struct sta_info, addr),
	.key_len = ETH_ALEN,
	.max_size = CONFIG_MAC80211_STA_HASH_MAX_SIZE,
};

/* Caller must hold local->sta_mtx */
static int sta_info_hash_del(struct ieee80211_local *local,
			     struct sta_info *sta)
{
	return rhltable_remove(&local->sta_hash, &sta->hash_node,
			       sta_rht_params);
}

static void __cleanup_single_sta(struct sta_info *sta)
{
	int ac, i;
	struct tid_ampdu_tx *tid_tx;
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct ieee80211_local *local = sdata->local;
	struct fq *fq = &local->fq;
	struct ps_data *ps;

	if (test_sta_flag(sta, WLAN_STA_PS_STA) ||
	    test_sta_flag(sta, WLAN_STA_PS_DRIVER) ||
	    test_sta_flag(sta, WLAN_STA_PS_DELIVER)) {
		if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
		    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
			ps = &sdata->bss->ps;
		else if (ieee80211_vif_is_mesh(&sdata->vif))
			ps = &sdata->u.mesh.ps;
		else
			return;

		clear_sta_flag(sta, WLAN_STA_PS_STA);
		clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
		clear_sta_flag(sta, WLAN_STA_PS_DELIVER);

		atomic_dec(&ps->num_sta_ps);
	}

	if (sta->sta.txq[0]) {
		for (i = 0; i < ARRAY_SIZE(sta->sta.txq); i++) {
			struct txq_info *txqi = to_txq_info(sta->sta.txq[i]);

			spin_lock_bh(&fq->lock);
			ieee80211_txq_purge(local, txqi);
			spin_unlock_bh(&fq->lock);
		}
	}

	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
		local->total_ps_buffered -= skb_queue_len(&sta->ps_tx_buf[ac]);
		ieee80211_purge_tx_queue(&local->hw, &sta->ps_tx_buf[ac]);
		ieee80211_purge_tx_queue(&local->hw, &sta->tx_filtered[ac]);
	}

	if (ieee80211_vif_is_mesh(&sdata->vif))
		mesh_sta_cleanup(sta);

	cancel_work_sync(&sta->drv_deliver_wk);

	/*
	 * Destroy aggregation state here. It would be nice to wait for the
	 * driver to finish aggregation stop and then clean up, but for now
	 * drivers have to handle aggregation stop being requested, followed
	 * directly by station destruction.
	 */
	for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
		kfree(sta->ampdu_mlme.tid_start_tx[i]);
		tid_tx = rcu_dereference_raw(sta->ampdu_mlme.tid_tx[i]);
		if (!tid_tx)
			continue;
		ieee80211_purge_tx_queue(&local->hw, &tid_tx->pending);
		kfree(tid_tx);
	}
}

static void cleanup_single_sta(struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct ieee80211_local *local = sdata->local;

	__cleanup_single_sta(sta);
	sta_info_free(local, sta);
}

struct rhlist_head *sta_info_hash_lookup(struct ieee80211_local *local,
					 const u8 *addr)
{
	return rhltable_lookup(&local->sta_hash, addr, sta_rht_params);
}

/* protected by RCU */
struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata,
			      const u8 *addr)
{
	struct ieee80211_local *local = sdata->local;
	struct rhlist_head *tmp;
	struct sta_info *sta;

	rcu_read_lock();
	for_each_sta_info(local, addr, sta, tmp) {
		if (sta->sdata == sdata) {
			rcu_read_unlock();
			/* this is safe as the caller must already hold
			 * another rcu read section or the mutex
			 */
			return sta;
		}
	}
	rcu_read_unlock();
	return NULL;
}

/*
 * Get sta info either from the specified interface
 * or from one of its vlans
 */
struct sta_info *sta_info_get_bss(struct ieee80211_sub_if_data *sdata,
				  const u8 *addr)
{
	struct ieee80211_local *local = sdata->local;
	struct rhlist_head *tmp;
	struct sta_info *sta;

	rcu_read_lock();
	for_each_sta_info(local, addr, sta, tmp) {
		if (sta->sdata == sdata ||
		    (sta->sdata->bss && sta->sdata->bss == sdata->bss)) {
			rcu_read_unlock();
			/* this is safe as the caller must already hold
			 * another rcu read section or the mutex
			 */
			return sta;
		}
	}
	rcu_read_unlock();
	return NULL;
}

struct sta_info *sta_info_get_by_idx(struct ieee80211_sub_if_data *sdata,
				     int idx)
{
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
	int i = 0;

	list_for_each_entry_rcu(sta, &local->sta_list, list) {
		if (sdata != sta->sdata)
			continue;
		if (i < idx) {
			++i;
			continue;
		}
		return sta;
	}

	return NULL;
}

/**
 * sta_info_free - free STA
 *
 * @local: pointer to the global information
 * @sta: STA info to free
 *
 * This function must undo everything done by sta_info_alloc()
 * that may happen before sta_info_insert(). It may only be
 * called when sta_info_insert() has not been attempted (and
 * if that fails, the station is freed anyway.)
 */
void sta_info_free(struct ieee80211_local *local, struct sta_info *sta)
{
	if (sta->rate_ctrl)
		rate_control_free_sta(sta);

	sta_dbg(sta->sdata, "Destroyed STA %pM\n", sta->sta.addr);

	if (sta->sta.txq[0])
		kfree(to_txq_info(sta->sta.txq[0]));
	kfree(rcu_dereference_raw(sta->sta.rates));
#ifdef CONFIG_MAC80211_MESH
	kfree(sta->mesh);
#endif
	free_percpu(sta->pcpu_rx_stats);
	kfree(sta);
}

/* Caller must hold local->sta_mtx */
static int sta_info_hash_add(struct ieee80211_local *local,
			     struct sta_info *sta)
{
	return rhltable_insert(&local->sta_hash, &sta->hash_node,
			       sta_rht_params);
}

static void sta_deliver_ps_frames(struct work_struct *wk)
{
	struct sta_info *sta;

	sta = container_of(wk, struct sta_info, drv_deliver_wk);

	if (sta->dead)
		return;

	local_bh_disable();
	if (!test_sta_flag(sta, WLAN_STA_PS_STA))
		ieee80211_sta_ps_deliver_wakeup(sta);
	else if (test_and_clear_sta_flag(sta, WLAN_STA_PSPOLL))
		ieee80211_sta_ps_deliver_poll_response(sta);
	else if (test_and_clear_sta_flag(sta, WLAN_STA_UAPSD))
		ieee80211_sta_ps_deliver_uapsd(sta);
	local_bh_enable();
}

static int sta_prepare_rate_control(struct ieee80211_local *local,
				    struct sta_info *sta, gfp_t gfp)
{
	if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL))
		return 0;

	sta->rate_ctrl = local->rate_ctrl;
	sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl,
						     sta, gfp);
	if (!sta->rate_ctrl_priv)
		return -ENOMEM;

	return 0;
}

struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
				const u8 *addr, gfp_t gfp)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_hw *hw = &local->hw;
	struct sta_info *sta;
	int i;

	sta = kzalloc(sizeof(*sta) + hw->sta_data_size, gfp);
	if (!sta)
		return NULL;

	if (ieee80211_hw_check(hw, USES_RSS)) {
		sta->pcpu_rx_stats =
			alloc_percpu(struct ieee80211_sta_rx_stats);
		if (!sta->pcpu_rx_stats)
			goto free;
	}

	spin_lock_init(&sta->lock);
	spin_lock_init(&sta->ps_lock);
	INIT_WORK(&sta->drv_deliver_wk, sta_deliver_ps_frames);
	INIT_WORK(&sta->ampdu_mlme.work, ieee80211_ba_session_work);
	mutex_init(&sta->ampdu_mlme.mtx);
#ifdef CONFIG_MAC80211_MESH
	if (ieee80211_vif_is_mesh(&sdata->vif)) {
		sta->mesh = kzalloc(sizeof(*sta->mesh), gfp);
		if (!sta->mesh)
			goto free;
		spin_lock_init(&sta->mesh->plink_lock);
		if (ieee80211_vif_is_mesh(&sdata->vif) &&
		    !sdata->u.mesh.user_mpm)
			init_timer(&sta->mesh->plink_timer);
		sta->mesh->nonpeer_pm = NL80211_MESH_POWER_ACTIVE;
	}
#endif

	memcpy(sta->addr, addr, ETH_ALEN);
	memcpy(sta->sta.addr, addr, ETH_ALEN);
	sta->sta.max_rx_aggregation_subframes =
		local->hw.max_rx_aggregation_subframes;

	sta->local = local;
	sta->sdata = sdata;
	sta->rx_stats.last_rx = jiffies;

	u64_stats_init(&sta->rx_stats.syncp);

	sta->sta_state = IEEE80211_STA_NONE;

	/* Mark TID as unreserved */
	sta->reserved_tid = IEEE80211_TID_UNRESERVED;

	sta->last_connected = ktime_get_seconds();
	ewma_signal_init(&sta->rx_stats_avg.signal);
	for (i = 0; i < ARRAY_SIZE(sta->rx_stats_avg.chain_signal); i++)
		ewma_signal_init(&sta->rx_stats_avg.chain_signal[i]);

	if (local->ops->wake_tx_queue) {
		void *txq_data;
		int size = sizeof(struct txq_info) +
			   ALIGN(hw->txq_data_size, sizeof(void *));

		txq_data = kcalloc(ARRAY_SIZE(sta->sta.txq), size, gfp);
		if (!txq_data)
			goto free;

		for (i = 0; i < ARRAY_SIZE(sta->sta.txq); i++) {
			struct txq_info *txq = txq_data + i * size;

			ieee80211_txq_init(sdata, sta, txq, i);
		}
	}

	if (sta_prepare_rate_control(local, sta, gfp))
		goto free_txq;

	for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
		/*
		 * timer_to_tid must be initialized with identity mapping
		 * to enable session_timer's data differentiation. See
		 * sta_rx_agg_session_timer_expired for usage.
		 */
		sta->timer_to_tid[i] = i;
	}
	for (i = 0; i < IEEE80211_NUM_ACS; i++) {
		skb_queue_head_init(&sta->ps_tx_buf[i]);
		skb_queue_head_init(&sta->tx_filtered[i]);
	}

	for (i = 0; i < IEEE80211_NUM_TIDS; i++)
		sta->last_seq_ctrl[i] = cpu_to_le16(USHRT_MAX);

	sta->sta.smps_mode = IEEE80211_SMPS_OFF;
	if (sdata->vif.type == NL80211_IFTYPE_AP ||
	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
		struct ieee80211_supported_band *sband =
			hw->wiphy->bands[ieee80211_get_sdata_band(sdata)];
		u8 smps = (sband->ht_cap.cap & IEEE80211_HT_CAP_SM_PS) >>
				IEEE80211_HT_CAP_SM_PS_SHIFT;
		/*
		 * Assume that hostapd advertises our caps in the beacon and
		 * this is the known_smps_mode for a station that just assciated
		 */
		switch (smps) {
		case WLAN_HT_SMPS_CONTROL_DISABLED:
			sta->known_smps_mode = IEEE80211_SMPS_OFF;
			break;
		case WLAN_HT_SMPS_CONTROL_STATIC:
			sta->known_smps_mode = IEEE80211_SMPS_STATIC;
			break;
		case WLAN_HT_SMPS_CONTROL_DYNAMIC:
			sta->known_smps_mode = IEEE80211_SMPS_DYNAMIC;
			break;
		default:
			WARN_ON(1);
		}
	}

	sta->sta.max_rc_amsdu_len = IEEE80211_MAX_MPDU_LEN_HT_BA;

	sta_dbg(sdata, "Allocated STA %pM\n", sta->sta.addr);

	return sta;

free_txq:
	if (sta->sta.txq[0])
		kfree(to_txq_info(sta->sta.txq[0]));
free:
#ifdef CONFIG_MAC80211_MESH
	kfree(sta->mesh);
#endif
	kfree(sta);
	return NULL;
}

static int sta_info_insert_check(struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;

	/*
	 * Can't be a WARN_ON because it can be triggered through a race:
	 * something inserts a STA (on one CPU) without holding the RTNL
	 * and another CPU turns off the net device.
	 */
	if (unlikely(!ieee80211_sdata_running(sdata)))
		return -ENETDOWN;

	if (WARN_ON(ether_addr_equal(sta->sta.addr, sdata->vif.addr) ||
		    is_multicast_ether_addr(sta->sta.addr)))
		return -EINVAL;

	/* The RCU read lock is required by rhashtable due to
	 * asynchronous resize/rehash.  We also require the mutex
	 * for correctness.
	 */
	rcu_read_lock();
	lockdep_assert_held(&sdata->local->sta_mtx);
	if (ieee80211_hw_check(&sdata->local->hw, NEEDS_UNIQUE_STA_ADDR) &&
	    ieee80211_find_sta_by_ifaddr(&sdata->local->hw, sta->addr, NULL)) {
		rcu_read_unlock();
		return -ENOTUNIQ;
	}
	rcu_read_unlock();

	return 0;
}

static int sta_info_insert_drv_state(struct ieee80211_local *local,
				     struct ieee80211_sub_if_data *sdata,
				     struct sta_info *sta)
{
	enum ieee80211_sta_state state;
	int err = 0;

	for (state = IEEE80211_STA_NOTEXIST; state < sta->sta_state; state++) {
		err = drv_sta_state(local, sdata, sta, state, state + 1);
		if (err)
			break;
	}

	if (!err) {
		/*
		 * Drivers using legacy sta_add/sta_remove callbacks only
		 * get uploaded set to true after sta_add is called.
		 */
		if (!local->ops->sta_add)
			sta->uploaded = true;
		return 0;
	}

	if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
		sdata_info(sdata,
			   "failed to move IBSS STA %pM to state %d (%d) - keeping it anyway\n",
			   sta->sta.addr, state + 1, err);
		err = 0;
	}

	/* unwind on error */
	for (; state > IEEE80211_STA_NOTEXIST; state--)
		WARN_ON(drv_sta_state(local, sdata, sta, state, state - 1));

	return err;
}

/*
 * should be called with sta_mtx locked
 * this function replaces the mutex lock
 * with a RCU lock
 */
static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU)
{
	struct ieee80211_local *local = sta->local;
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct station_info *sinfo;
	int err = 0;

	lockdep_assert_held(&local->sta_mtx);

	sinfo = kzalloc(sizeof(struct station_info), GFP_KERNEL);
	if (!sinfo) {
		err = -ENOMEM;
		goto out_err;
	}

	/* check if STA exists already */
	if (sta_info_get_bss(sdata, sta->sta.addr)) {
		err = -EEXIST;
		goto out_err;
	}

	local->num_sta++;
	local->sta_generation++;
	smp_mb();

	/* simplify things and don't accept BA sessions yet */
	set_sta_flag(sta, WLAN_STA_BLOCK_BA);

	/* make the station visible */
	err = sta_info_hash_add(local, sta);
	if (err)
		goto out_drop_sta;

	list_add_tail_rcu(&sta->list, &local->sta_list);

	/* notify driver */
	err = sta_info_insert_drv_state(local, sdata, sta);
	if (err)
		goto out_remove;

	set_sta_flag(sta, WLAN_STA_INSERTED);
	/* accept BA sessions now */
	clear_sta_flag(sta, WLAN_STA_BLOCK_BA);

	ieee80211_sta_debugfs_add(sta);
	rate_control_add_sta_debugfs(sta);

	sinfo->generation = local->sta_generation;
	cfg80211_new_sta(sdata->dev, sta->sta.addr, sinfo, GFP_KERNEL);
	kfree(sinfo);

	sta_dbg(sdata, "Inserted STA %pM\n", sta->sta.addr);

	/* move reference to rcu-protected */
	rcu_read_lock();
	mutex_unlock(&local->sta_mtx);

	if (ieee80211_vif_is_mesh(&sdata->vif))
		mesh_accept_plinks_update(sdata);

	return 0;
 out_remove:
	sta_info_hash_del(local, sta);
	list_del_rcu(&sta->list);
 out_drop_sta:
	local->num_sta--;
	synchronize_net();
	__cleanup_single_sta(sta);
 out_err:
	mutex_unlock(&local->sta_mtx);
	kfree(sinfo);
	rcu_read_lock();
	return err;
}

int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU)
{
	struct ieee80211_local *local = sta->local;
	int err;

	might_sleep();

	mutex_lock(&local->sta_mtx);

	err = sta_info_insert_check(sta);
	if (err) {
		mutex_unlock(&local->sta_mtx);
		rcu_read_lock();
		goto out_free;
	}

	err = sta_info_insert_finish(sta);
	if (err)
		goto out_free;

	return 0;
 out_free:
	sta_info_free(local, sta);
	return err;
}

int sta_info_insert(struct sta_info *sta)
{
	int err = sta_info_insert_rcu(sta);

	rcu_read_unlock();

	return err;
}

static inline void __bss_tim_set(u8 *tim, u16 id)
{
	/*
	 * This format has been mandated by the IEEE specifications,
	 * so this line may not be changed to use the __set_bit() format.
	 */
	tim[id / 8] |= (1 << (id % 8));
}

static inline void __bss_tim_clear(u8 *tim, u16 id)
{
	/*
	 * This format has been mandated by the IEEE specifications,
	 * so this line may not be changed to use the __clear_bit() format.
	 */
	tim[id / 8] &= ~(1 << (id % 8));
}

static inline bool __bss_tim_get(u8 *tim, u16 id)
{
	/*
	 * This format has been mandated by the IEEE specifications,
	 * so this line may not be changed to use the test_bit() format.
	 */
	return tim[id / 8] & (1 << (id % 8));
}

static unsigned long ieee80211_tids_for_ac(int ac)
{
	/* If we ever support TIDs > 7, this obviously needs to be adjusted */
	switch (ac) {
	case IEEE80211_AC_VO:
		return BIT(6) | BIT(7);
	case IEEE80211_AC_VI:
		return BIT(4) | BIT(5);
	case IEEE80211_AC_BE:
		return BIT(0) | BIT(3);
	case IEEE80211_AC_BK:
		return BIT(1) | BIT(2);
	default:
		WARN_ON(1);
		return 0;
	}
}

static void __sta_info_recalc_tim(struct sta_info *sta, bool ignore_pending)
{
	struct ieee80211_local *local = sta->local;
	struct ps_data *ps;
	bool indicate_tim = false;
	u8 ignore_for_tim = sta->sta.uapsd_queues;
	int ac;
	u16 id = sta->sta.aid;

	if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
	    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
		if (WARN_ON_ONCE(!sta->sdata->bss))
			return;

		ps = &sta->sdata->bss->ps;
#ifdef CONFIG_MAC80211_MESH
	} else if (ieee80211_vif_is_mesh(&sta->sdata->vif)) {
		ps = &sta->sdata->u.mesh.ps;
#endif
	} else {
		return;
	}

	/* No need to do anything if the driver does all */
	if (ieee80211_hw_check(&local->hw, AP_LINK_PS))
		return;

	if (sta->dead)
		goto done;

	/*
	 * If all ACs are delivery-enabled then we should build
	 * the TIM bit for all ACs anyway; if only some are then
	 * we ignore those and build the TIM bit using only the
	 * non-enabled ones.
	 */
	if (ignore_for_tim == BIT(IEEE80211_NUM_ACS) - 1)
		ignore_for_tim = 0;

	if (ignore_pending)
		ignore_for_tim = BIT(IEEE80211_NUM_ACS) - 1;

	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
		unsigned long tids;

		if (ignore_for_tim & ieee80211_ac_to_qos_mask[ac])
			continue;

		indicate_tim |= !skb_queue_empty(&sta->tx_filtered[ac]) ||
				!skb_queue_empty(&sta->ps_tx_buf[ac]);
		if (indicate_tim)
			break;

		tids = ieee80211_tids_for_ac(ac);

		indicate_tim |=
			sta->driver_buffered_tids & tids;
		indicate_tim |=
			sta->txq_buffered_tids & tids;
	}

 done:
	spin_lock_bh(&local->tim_lock);

	if (indicate_tim == __bss_tim_get(ps->tim, id))
		goto out_unlock;

	if (indicate_tim)
		__bss_tim_set(ps->tim, id);
	else
		__bss_tim_clear(ps->tim, id);

	if (local->ops->set_tim && !WARN_ON(sta->dead)) {
		local->tim_in_locked_section = true;
		drv_set_tim(local, &sta->sta, indicate_tim);
		local->tim_in_locked_section = false;
	}

out_unlock:
	spin_unlock_bh(&local->tim_lock);
}

void sta_info_recalc_tim(struct sta_info *sta)
{
	__sta_info_recalc_tim(sta, false);
}

static bool sta_info_buffer_expired(struct sta_info *sta, struct sk_buff *skb)
{
	struct ieee80211_tx_info *info;
	int timeout;

	if (!skb)
		return false;

	info = IEEE80211_SKB_CB(skb);

	/* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
	timeout = (sta->listen_interval *
		   sta->sdata->vif.bss_conf.beacon_int *
		   32 / 15625) * HZ;
	if (timeout < STA_TX_BUFFER_EXPIRE)
		timeout = STA_TX_BUFFER_EXPIRE;
	return time_after(jiffies, info->control.jiffies + timeout);
}


static bool sta_info_cleanup_expire_buffered_ac(struct ieee80211_local *local,
						struct sta_info *sta, int ac)
{
	unsigned long flags;
	struct sk_buff *skb;

	/*
	 * First check for frames that should expire on the filtered
	 * queue. Frames here were rejected by the driver and are on
	 * a separate queue to avoid reordering with normal PS-buffered
	 * frames. They also aren't accounted for right now in the
	 * total_ps_buffered counter.
	 */
	for (;;) {
		spin_lock_irqsave(&sta->tx_filtered[ac].lock, flags);
		skb = skb_peek(&sta->tx_filtered[ac]);
		if (sta_info_buffer_expired(sta, skb))
			skb = __skb_dequeue(&sta->tx_filtered[ac]);
		else
			skb = NULL;
		spin_unlock_irqrestore(&sta->tx_filtered[ac].lock, flags);

		/*
		 * Frames are queued in order, so if this one
		 * hasn't expired yet we can stop testing. If
		 * we actually reached the end of the queue we
		 * also need to stop, of course.
		 */
		if (!skb)
			break;
		ieee80211_free_txskb(&local->hw, skb);
	}

	/*
	 * Now also check the normal PS-buffered queue, this will
	 * only find something if the filtered queue was emptied
	 * since the filtered frames are all before the normal PS
	 * buffered frames.
	 */
	for (;;) {
		spin_lock_irqsave(&sta->ps_tx_buf[ac].lock, flags);
		skb = skb_peek(&sta->ps_tx_buf[ac]);
		if (sta_info_buffer_expired(sta, skb))
			skb = __skb_dequeue(&sta->ps_tx_buf[ac]);
		else
			skb = NULL;
		spin_unlock_irqrestore(&sta->ps_tx_buf[ac].lock, flags);

		/*
		 * frames are queued in order, so if this one
		 * hasn't expired yet (or we reached the end of
		 * the queue) we can stop testing
		 */
		if (!skb)
			break;

		local->total_ps_buffered--;
		ps_dbg(sta->sdata, "Buffered frame expired (STA %pM)\n",
		       sta->sta.addr);
		ieee80211_free_txskb(&local->hw, skb);
	}

	/*
	 * Finally, recalculate the TIM bit for this station -- it might
	 * now be clear because the station was too slow to retrieve its
	 * frames.
	 */
	sta_info_recalc_tim(sta);

	/*
	 * Return whether there are any frames still buffered, this is
	 * used to check whether the cleanup timer still needs to run,
	 * if there are no frames we don't need to rearm the timer.
	 */
	return !(skb_queue_empty(&sta->ps_tx_buf[ac]) &&
		 skb_queue_empty(&sta->tx_filtered[ac]));
}

static bool sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
					     struct sta_info *sta)
{
	bool have_buffered = false;
	int ac;

	/* This is only necessary for stations on BSS/MBSS interfaces */
	if (!sta->sdata->bss &&
	    !ieee80211_vif_is_mesh(&sta->sdata->vif))
		return false;

	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
		have_buffered |=
			sta_info_cleanup_expire_buffered_ac(local, sta, ac);

	return have_buffered;
}

static int __must_check __sta_info_destroy_part1(struct sta_info *sta)
{
	struct ieee80211_local *local;
	struct ieee80211_sub_if_data *sdata;
	int ret;

	might_sleep();

	if (!sta)
		return -ENOENT;

	local = sta->local;
	sdata = sta->sdata;

	lockdep_assert_held(&local->sta_mtx);

	/*
	 * Before removing the station from the driver and
	 * rate control, it might still start new aggregation
	 * sessions -- block that to make sure the tear-down
	 * will be sufficient.
	 */
	set_sta_flag(sta, WLAN_STA_BLOCK_BA);
	ieee80211_sta_tear_down_BA_sessions(sta, AGG_STOP_DESTROY_STA);

	/*
	 * Before removing the station from the driver there might be pending
	 * rx frames on RSS queues sent prior to the disassociation - wait for
	 * all such frames to be processed.
	 */
	drv_sync_rx_queues(local, sta);

	ret = sta_info_hash_del(local, sta);
	if (WARN_ON(ret))
		return ret;

	/*
	 * for TDLS peers, make sure to return to the base channel before
	 * removal.
	 */
	if (test_sta_flag(sta, WLAN_STA_TDLS_OFF_CHANNEL)) {
		drv_tdls_cancel_channel_switch(local, sdata, &sta->sta);
		clear_sta_flag(sta, WLAN_STA_TDLS_OFF_CHANNEL);
	}

	list_del_rcu(&sta->list);
	sta->removed = true;

	drv_sta_pre_rcu_remove(local, sta->sdata, sta);

	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
	    rcu_access_pointer(sdata->u.vlan.sta) == sta)
		RCU_INIT_POINTER(sdata->u.vlan.sta, NULL);

	return 0;
}

static void __sta_info_destroy_part2(struct sta_info *sta)
{
	struct ieee80211_local *local = sta->local;
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct station_info *sinfo;
	int ret;

	/*
	 * NOTE: This assumes at least synchronize_net() was done
	 *	 after _part1 and before _part2!
	 */

	might_sleep();
	lockdep_assert_held(&local->sta_mtx);

	/* now keys can no longer be reached */
	ieee80211_free_sta_keys(local, sta);

	/* disable TIM bit - last chance to tell driver */
	__sta_info_recalc_tim(sta, true);

	sta->dead = true;

	local->num_sta--;
	local->sta_generation++;

	while (sta->sta_state > IEEE80211_STA_NONE) {
		ret = sta_info_move_state(sta, sta->sta_state - 1);
		if (ret) {
			WARN_ON_ONCE(1);
			break;
		}
	}

	if (sta->uploaded) {
		ret = drv_sta_state(local, sdata, sta, IEEE80211_STA_NONE,
				    IEEE80211_STA_NOTEXIST);
		WARN_ON_ONCE(ret != 0);
	}

	sta_dbg(sdata, "Removed STA %pM\n", sta->sta.addr);

	sinfo = kzalloc(sizeof(*sinfo), GFP_KERNEL);
	if (sinfo)
		sta_set_sinfo(sta, sinfo);
	cfg80211_del_sta_sinfo(sdata->dev, sta->sta.addr, sinfo, GFP_KERNEL);
	kfree(sinfo);

	rate_control_remove_sta_debugfs(sta);
	ieee80211_sta_debugfs_remove(sta);

	cleanup_single_sta(sta);
}

int __must_check __sta_info_destroy(struct sta_info *sta)
{
	int err = __sta_info_destroy_part1(sta);

	if (err)
		return err;

	synchronize_net();

	__sta_info_destroy_part2(sta);

	return 0;
}

int sta_info_destroy_addr(struct ieee80211_sub_if_data *sdata, const u8 *addr)
{
	struct sta_info *sta;
	int ret;

	mutex_lock(&sdata->local->sta_mtx);
	sta = sta_info_get(sdata, addr);
	ret = __sta_info_destroy(sta);
	mutex_unlock(&sdata->local->sta_mtx);

	return ret;
}

int sta_info_destroy_addr_bss(struct ieee80211_sub_if_data *sdata,
			      const u8 *addr)
{
	struct sta_info *sta;
	int ret;

	mutex_lock(&sdata->local->sta_mtx);
	sta = sta_info_get_bss(sdata, addr);
	ret = __sta_info_destroy(sta);
	mutex_unlock(&sdata->local->sta_mtx);

	return ret;
}

static void sta_info_cleanup(unsigned long data)
{
	struct ieee80211_local *local = (struct ieee80211_local *) data;
	struct sta_info *sta;
	bool timer_needed = false;

	rcu_read_lock();
	list_for_each_entry_rcu(sta, &local->sta_list, list)
		if (sta_info_cleanup_expire_buffered(local, sta))
			timer_needed = true;
	rcu_read_unlock();

	if (local->quiescing)
		return;

	if (!timer_needed)
		return;

	mod_timer(&local->sta_cleanup,
		  round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL));
}

int sta_info_init(struct ieee80211_local *local)
{
	int err;

	err = rhltable_init(&local->sta_hash, &sta_rht_params);
	if (err)
		return err;

	spin_lock_init(&local->tim_lock);
	mutex_init(&local->sta_mtx);
	INIT_LIST_HEAD(&local->sta_list);

	setup_timer(&local->sta_cleanup, sta_info_cleanup,
		    (unsigned long)local);
	return 0;
}

void sta_info_stop(struct ieee80211_local *local)
{
	del_timer_sync(&local->sta_cleanup);
	rhltable_destroy(&local->sta_hash);
}


int __sta_info_flush(struct ieee80211_sub_if_data *sdata, bool vlans)
{
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta, *tmp;
	LIST_HEAD(free_list);
	int ret = 0;

	might_sleep();

	WARN_ON(vlans && sdata->vif.type != NL80211_IFTYPE_AP);
	WARN_ON(vlans && !sdata->bss);

	mutex_lock(&local->sta_mtx);
	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
		if (sdata == sta->sdata ||
		    (vlans && sdata->bss == sta->sdata->bss)) {
			if (!WARN_ON(__sta_info_destroy_part1(sta)))
				list_add(&sta->free_list, &free_list);
			ret++;
		}
	}

	if (!list_empty(&free_list)) {
		synchronize_net();
		list_for_each_entry_safe(sta, tmp, &free_list, free_list)
			__sta_info_destroy_part2(sta);
	}
	mutex_unlock(&local->sta_mtx);

	return ret;
}

void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
			  unsigned long exp_time)
{
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta, *tmp;

	mutex_lock(&local->sta_mtx);

	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
		unsigned long last_active = ieee80211_sta_last_active(sta);

		if (sdata != sta->sdata)
			continue;

		if (time_is_before_jiffies(last_active + exp_time)) {
			sta_dbg(sta->sdata, "expiring inactive STA %pM\n",
				sta->sta.addr);

			if (ieee80211_vif_is_mesh(&sdata->vif) &&
			    test_sta_flag(sta, WLAN_STA_PS_STA))
				atomic_dec(&sdata->u.mesh.ps.num_sta_ps);

			WARN_ON(__sta_info_destroy(sta));
		}
	}

	mutex_unlock(&local->sta_mtx);
}

struct ieee80211_sta *ieee80211_find_sta_by_ifaddr(struct ieee80211_hw *hw,
						   const u8 *addr,
						   const u8 *localaddr)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct rhlist_head *tmp;
	struct sta_info *sta;

	/*
	 * Just return a random station if localaddr is NULL
	 * ... first in list.
	 */
	for_each_sta_info(local, addr, sta, tmp) {
		if (localaddr &&
		    !ether_addr_equal(sta->sdata->vif.addr, localaddr))
			continue;
		if (!sta->uploaded)
			return NULL;
		return &sta->sta;
	}

	return NULL;
}
EXPORT_SYMBOL_GPL(ieee80211_find_sta_by_ifaddr);

struct ieee80211_sta *ieee80211_find_sta(struct ieee80211_vif *vif,
					 const u8 *addr)
{
	struct sta_info *sta;

	if (!vif)
		return NULL;

	sta = sta_info_get_bss(vif_to_sdata(vif), addr);
	if (!sta)
		return NULL;

	if (!sta->uploaded)
		return NULL;

	return &sta->sta;
}
EXPORT_SYMBOL(ieee80211_find_sta);

/* powersave support code */
void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct ieee80211_local *local = sdata->local;
	struct sk_buff_head pending;
	int filtered = 0, buffered = 0, ac, i;
	unsigned long flags;
	struct ps_data *ps;

	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
		sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
				     u.ap);

	if (sdata->vif.type == NL80211_IFTYPE_AP)
		ps = &sdata->bss->ps;
	else if (ieee80211_vif_is_mesh(&sdata->vif))
		ps = &sdata->u.mesh.ps;
	else
		return;

	clear_sta_flag(sta, WLAN_STA_SP);

	BUILD_BUG_ON(BITS_TO_LONGS(IEEE80211_NUM_TIDS) > 1);
	sta->driver_buffered_tids = 0;
	sta->txq_buffered_tids = 0;

	if (!ieee80211_hw_check(&local->hw, AP_LINK_PS))
		drv_sta_notify(local, sdata, STA_NOTIFY_AWAKE, &sta->sta);

	if (sta->sta.txq[0]) {
		for (i = 0; i < ARRAY_SIZE(sta->sta.txq); i++) {
			if (!txq_has_queue(sta->sta.txq[i]))
				continue;

			drv_wake_tx_queue(local, to_txq_info(sta->sta.txq[i]));
		}
	}

	skb_queue_head_init(&pending);

	/* sync with ieee80211_tx_h_unicast_ps_buf */
	spin_lock(&sta->ps_lock);
	/* Send all buffered frames to the station */
	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
		int count = skb_queue_len(&pending), tmp;

		spin_lock_irqsave(&sta->tx_filtered[ac].lock, flags);
		skb_queue_splice_tail_init(&sta->tx_filtered[ac], &pending);
		spin_unlock_irqrestore(&sta->tx_filtered[ac].lock, flags);
		tmp = skb_queue_len(&pending);
		filtered += tmp - count;
		count = tmp;

		spin_lock_irqsave(&sta->ps_tx_buf[ac].lock, flags);
		skb_queue_splice_tail_init(&sta->ps_tx_buf[ac], &pending);
		spin_unlock_irqrestore(&sta->ps_tx_buf[ac].lock, flags);
		tmp = skb_queue_len(&pending);
		buffered += tmp - count;
	}

	ieee80211_add_pending_skbs(local, &pending);

	/* now we're no longer in the deliver code */
	clear_sta_flag(sta, WLAN_STA_PS_DELIVER);

	/* The station might have polled and then woken up before we responded,
	 * so clear these flags now to avoid them sticking around.
	 */
	clear_sta_flag(sta, WLAN_STA_PSPOLL);
	clear_sta_flag(sta, WLAN_STA_UAPSD);
	spin_unlock(&sta->ps_lock);

	atomic_dec(&ps->num_sta_ps);

	/* This station just woke up and isn't aware of our SMPS state */
	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
	    !ieee80211_smps_is_restrictive(sta->known_smps_mode,
					   sdata->smps_mode) &&
	    sta->known_smps_mode != sdata->bss->req_smps &&
	    sta_info_tx_streams(sta) != 1) {
		ht_dbg(sdata,
		       "%pM just woke up and MIMO capable - update SMPS\n",
		       sta->sta.addr);
		ieee80211_send_smps_action(sdata, sdata->bss->req_smps,
					   sta->sta.addr,
					   sdata->vif.bss_conf.bssid);
	}

	local->total_ps_buffered -= buffered;

	sta_info_recalc_tim(sta);

	ps_dbg(sdata,
	       "STA %pM aid %d sending %d filtered/%d PS frames since STA not sleeping anymore\n",
	       sta->sta.addr, sta->sta.aid, filtered, buffered);

	ieee80211_check_fast_xmit(sta);
}

static void ieee80211_send_null_response(struct sta_info *sta, int tid,
					 enum ieee80211_frame_release_type reason,
					 bool call_driver, bool more_data)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_qos_hdr *nullfunc;
	struct sk_buff *skb;
	int size = sizeof(*nullfunc);
	__le16 fc;
	bool qos = sta->sta.wme;
	struct ieee80211_tx_info *info;
	struct ieee80211_chanctx_conf *chanctx_conf;

	if (qos) {
		fc = cpu_to_le16(IEEE80211_FTYPE_DATA |
				 IEEE80211_STYPE_QOS_NULLFUNC |
				 IEEE80211_FCTL_FROMDS);
	} else {
		size -= 2;
		fc = cpu_to_le16(IEEE80211_FTYPE_DATA |
				 IEEE80211_STYPE_NULLFUNC |
				 IEEE80211_FCTL_FROMDS);
	}

	skb = dev_alloc_skb(local->hw.extra_tx_headroom + size);
	if (!skb)
		return;

	skb_reserve(skb, local->hw.extra_tx_headroom);

	nullfunc = (void *) skb_put(skb, size);
	nullfunc->frame_control = fc;
	nullfunc->duration_id = 0;
	memcpy(nullfunc->addr1, sta->sta.addr, ETH_ALEN);
	memcpy(nullfunc->addr2, sdata->vif.addr, ETH_ALEN);
	memcpy(nullfunc->addr3, sdata->vif.addr, ETH_ALEN);
	nullfunc->seq_ctrl = 0;

	skb->priority = tid;
	skb_set_queue_mapping(skb, ieee802_1d_to_ac[tid]);
	if (qos) {
		nullfunc->qos_ctrl = cpu_to_le16(tid);

		if (reason == IEEE80211_FRAME_RELEASE_UAPSD) {
			nullfunc->qos_ctrl |=
				cpu_to_le16(IEEE80211_QOS_CTL_EOSP);
			if (more_data)
				nullfunc->frame_control |=
					cpu_to_le16(IEEE80211_FCTL_MOREDATA);
		}
	}

	info = IEEE80211_SKB_CB(skb);

	/*
	 * Tell TX path to send this frame even though the
	 * STA may still remain is PS mode after this frame
	 * exchange. Also set EOSP to indicate this packet
	 * ends the poll/service period.
	 */
	info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER |
		       IEEE80211_TX_STATUS_EOSP |
		       IEEE80211_TX_CTL_REQ_TX_STATUS;

	info->control.flags |= IEEE80211_TX_CTRL_PS_RESPONSE;

	if (call_driver)
		drv_allow_buffered_frames(local, sta, BIT(tid), 1,
					  reason, false);

	skb->dev = sdata->dev;

	rcu_read_lock();
	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
	if (WARN_ON(!chanctx_conf)) {
		rcu_read_unlock();
		kfree_skb(skb);
		return;
	}

	info->band = chanctx_conf->def.chan->band;
	ieee80211_xmit(sdata, sta, skb);
	rcu_read_unlock();
}

static int find_highest_prio_tid(unsigned long tids)
{
	/* lower 3 TIDs aren't ordered perfectly */
	if (tids & 0xF8)
		return fls(tids) - 1;
	/* TID 0 is BE just like TID 3 */
	if (tids & BIT(0))
		return 0;
	return fls(tids) - 1;
}

/* Indicates if the MORE_DATA bit should be set in the last
 * frame obtained by ieee80211_sta_ps_get_frames.
 * Note that driver_release_tids is relevant only if
 * reason = IEEE80211_FRAME_RELEASE_PSPOLL
 */
static bool
ieee80211_sta_ps_more_data(struct sta_info *sta, u8 ignored_acs,
			   enum ieee80211_frame_release_type reason,
			   unsigned long driver_release_tids)
{
	int ac;

	/* If the driver has data on more than one TID then
	 * certainly there's more data if we release just a
	 * single frame now (from a single TID). This will
	 * only happen for PS-Poll.
	 */
	if (reason == IEEE80211_FRAME_RELEASE_PSPOLL &&
	    hweight16(driver_release_tids) > 1)
		return true;

	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
		if (ignored_acs & ieee80211_ac_to_qos_mask[ac])
			continue;

		if (!skb_queue_empty(&sta->tx_filtered[ac]) ||
		    !skb_queue_empty(&sta->ps_tx_buf[ac]))
			return true;
	}

	return false;
}

static void
ieee80211_sta_ps_get_frames(struct sta_info *sta, int n_frames, u8 ignored_acs,
			    enum ieee80211_frame_release_type reason,
			    struct sk_buff_head *frames,
			    unsigned long *driver_release_tids)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct ieee80211_local *local = sdata->local;
	int ac;

	/* Get response frame(s) and more data bit for the last one. */
	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
		unsigned long tids;

		if (ignored_acs & ieee80211_ac_to_qos_mask[ac])
			continue;

		tids = ieee80211_tids_for_ac(ac);

		/* if we already have frames from software, then we can't also
		 * release from hardware queues
		 */
		if (skb_queue_empty(frames)) {
			*driver_release_tids |=
				sta->driver_buffered_tids & tids;
			*driver_release_tids |= sta->txq_buffered_tids & tids;
		}

		if (!*driver_release_tids) {
			struct sk_buff *skb;

			while (n_frames > 0) {
				skb = skb_dequeue(&sta->tx_filtered[ac]);
				if (!skb) {
					skb = skb_dequeue(
						&sta->ps_tx_buf[ac]);
					if (skb)
						local->total_ps_buffered--;
				}
				if (!skb)
					break;
				n_frames--;
				__skb_queue_tail(frames, skb);
			}
		}

		/* If we have more frames buffered on this AC, then abort the
		 * loop since we can't send more data from other ACs before
		 * the buffered frames from this.
		 */
		if (!skb_queue_empty(&sta->tx_filtered[ac]) ||
		    !skb_queue_empty(&sta->ps_tx_buf[ac]))
			break;
	}
}

static void
ieee80211_sta_ps_deliver_response(struct sta_info *sta,
				  int n_frames, u8 ignored_acs,
				  enum ieee80211_frame_release_type reason)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct ieee80211_local *local = sdata->local;
	unsigned long driver_release_tids = 0;
	struct sk_buff_head frames;
	bool more_data;

	/* Service or PS-Poll period starts */
	set_sta_flag(sta, WLAN_STA_SP);

	__skb_queue_head_init(&frames);

	ieee80211_sta_ps_get_frames(sta, n_frames, ignored_acs, reason,
				    &frames, &driver_release_tids);

	more_data = ieee80211_sta_ps_more_data(sta, ignored_acs, reason, driver_release_tids);

	if (driver_release_tids && reason == IEEE80211_FRAME_RELEASE_PSPOLL)
		driver_release_tids =
			BIT(find_highest_prio_tid(driver_release_tids));

	if (skb_queue_empty(&frames) && !driver_release_tids) {
		int tid, ac;

		/*
		 * For PS-Poll, this can only happen due to a race condition
		 * when we set the TIM bit and the station notices it, but
		 * before it can poll for the frame we expire it.
		 *
		 * For uAPSD, this is said in the standard (11.2.1.5 h):
		 *	At each unscheduled SP for a non-AP STA, the AP shall
		 *	attempt to transmit at least one MSDU or MMPDU, but no
		 *	more than the value specified in the Max SP Length field
		 *	in the QoS Capability element from delivery-enabled ACs,
		 *	that are destined for the non-AP STA.
		 *
		 * Since we have no other MSDU/MMPDU, transmit a QoS null frame.
		 */

		/* This will evaluate to 1, 3, 5 or 7. */
		for (ac = IEEE80211_AC_VO; ac < IEEE80211_NUM_ACS; ac++)
			if (ignored_acs & BIT(ac))
				continue;
		tid = 7 - 2 * ac;

		ieee80211_send_null_response(sta, tid, reason, true, false);
	} else if (!driver_release_tids) {
		struct sk_buff_head pending;
		struct sk_buff *skb;
		int num = 0;
		u16 tids = 0;
		bool need_null = false;

		skb_queue_head_init(&pending);

		while ((skb = __skb_dequeue(&frames))) {
			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
			struct ieee80211_hdr *hdr = (void *) skb->data;
			u8 *qoshdr = NULL;

			num++;

			/*
			 * Tell TX path to send this frame even though the
			 * STA may still remain is PS mode after this frame
			 * exchange.
			 */
			info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
			info->control.flags |= IEEE80211_TX_CTRL_PS_RESPONSE;

			/*
			 * Use MoreData flag to indicate whether there are
			 * more buffered frames for this STA
			 */
			if (more_data || !skb_queue_empty(&frames))
				hdr->frame_control |=
					cpu_to_le16(IEEE80211_FCTL_MOREDATA);
			else
				hdr->frame_control &=
					cpu_to_le16(~IEEE80211_FCTL_MOREDATA);

			if (ieee80211_is_data_qos(hdr->frame_control) ||
			    ieee80211_is_qos_nullfunc(hdr->frame_control))
				qoshdr = ieee80211_get_qos_ctl(hdr);

			tids |= BIT(skb->priority);

			__skb_queue_tail(&pending, skb);

			/* end service period after last frame or add one */
			if (!skb_queue_empty(&frames))
				continue;

			if (reason != IEEE80211_FRAME_RELEASE_UAPSD) {
				/* for PS-Poll, there's only one frame */
				info->flags |= IEEE80211_TX_STATUS_EOSP |
					       IEEE80211_TX_CTL_REQ_TX_STATUS;
				break;
			}

			/* For uAPSD, things are a bit more complicated. If the
			 * last frame has a QoS header (i.e. is a QoS-data or
			 * QoS-nulldata frame) then just set the EOSP bit there
			 * and be done.
			 * If the frame doesn't have a QoS header (which means
			 * it should be a bufferable MMPDU) then we can't set
			 * the EOSP bit in the QoS header; add a QoS-nulldata
			 * frame to the list to send it after the MMPDU.
			 *
			 * Note that this code is only in the mac80211-release
			 * code path, we assume that the driver will not buffer
			 * anything but QoS-data frames, or if it does, will
			 * create the QoS-nulldata frame by itself if needed.
			 *
			 * Cf. 802.11-2012 10.2.1.10 (c).
			 */
			if (qoshdr) {
				*qoshdr |= IEEE80211_QOS_CTL_EOSP;

				info->flags |= IEEE80211_TX_STATUS_EOSP |
					       IEEE80211_TX_CTL_REQ_TX_STATUS;
			} else {
				/* The standard isn't completely clear on this
				 * as it says the more-data bit should be set
				 * if there are more BUs. The QoS-Null frame
				 * we're about to send isn't buffered yet, we
				 * only create it below, but let's pretend it
				 * was buffered just in case some clients only
				 * expect more-data=0 when eosp=1.
				 */
				hdr->frame_control |=
					cpu_to_le16(IEEE80211_FCTL_MOREDATA);
				need_null = true;
				num++;
			}
			break;
		}

		drv_allow_buffered_frames(local, sta, tids, num,
					  reason, more_data);

		ieee80211_add_pending_skbs(local, &pending);

		if (need_null)
			ieee80211_send_null_response(
				sta, find_highest_prio_tid(tids),
				reason, false, false);

		sta_info_recalc_tim(sta);
	} else {
		int tid;

		/*
		 * We need to release a frame that is buffered somewhere in the
		 * driver ... it'll have to handle that.
		 * Note that the driver also has to check the number of frames
		 * on the TIDs we're releasing from - if there are more than
		 * n_frames it has to set the more-data bit (if we didn't ask
		 * it to set it anyway due to other buffered frames); if there
		 * are fewer than n_frames it has to make sure to adjust that
		 * to allow the service period to end properly.
		 */
		drv_release_buffered_frames(local, sta, driver_release_tids,
					    n_frames, reason, more_data);

		/*
		 * Note that we don't recalculate the TIM bit here as it would
		 * most likely have no effect at all unless the driver told us
		 * that the TID(s) became empty before returning here from the
		 * release function.
		 * Either way, however, when the driver tells us that the TID(s)
		 * became empty or we find that a txq became empty, we'll do the
		 * TIM recalculation.
		 */

		if (!sta->sta.txq[0])
			return;

		for (tid = 0; tid < ARRAY_SIZE(sta->sta.txq); tid++) {
			if (!(driver_release_tids & BIT(tid)) ||
			    txq_has_queue(sta->sta.txq[tid]))
				continue;

			sta_info_recalc_tim(sta);
			break;
		}
	}
}

void ieee80211_sta_ps_deliver_poll_response(struct sta_info *sta)
{
	u8 ignore_for_response = sta->sta.uapsd_queues;

	/*
	 * If all ACs are delivery-enabled then we should reply
	 * from any of them, if only some are enabled we reply
	 * only from the non-enabled ones.
	 */
	if (ignore_for_response == BIT(IEEE80211_NUM_ACS) - 1)
		ignore_for_response = 0;

	ieee80211_sta_ps_deliver_response(sta, 1, ignore_for_response,
					  IEEE80211_FRAME_RELEASE_PSPOLL);
}

void ieee80211_sta_ps_deliver_uapsd(struct sta_info *sta)
{
	int n_frames = sta->sta.max_sp;
	u8 delivery_enabled = sta->sta.uapsd_queues;

	/*
	 * If we ever grow support for TSPEC this might happen if
	 * the TSPEC update from hostapd comes in between a trigger
	 * frame setting WLAN_STA_UAPSD in the RX path and this
	 * actually getting called.
	 */
	if (!delivery_enabled)
		return;

	switch (sta->sta.max_sp) {
	case 1:
		n_frames = 2;
		break;
	case 2:
		n_frames = 4;
		break;
	case 3:
		n_frames = 6;
		break;
	case 0:
		/* XXX: what is a good value? */
		n_frames = 128;
		break;
	}

	ieee80211_sta_ps_deliver_response(sta, n_frames, ~delivery_enabled,
					  IEEE80211_FRAME_RELEASE_UAPSD);
}

void ieee80211_sta_block_awake(struct ieee80211_hw *hw,
			       struct ieee80211_sta *pubsta, bool block)
{
	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);

	trace_api_sta_block_awake(sta->local, pubsta, block);

	if (block) {
		set_sta_flag(sta, WLAN_STA_PS_DRIVER);
		ieee80211_clear_fast_xmit(sta);
		return;
	}

	if (!test_sta_flag(sta, WLAN_STA_PS_DRIVER))
		return;

	if (!test_sta_flag(sta, WLAN_STA_PS_STA)) {
		set_sta_flag(sta, WLAN_STA_PS_DELIVER);
		clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
		ieee80211_queue_work(hw, &sta->drv_deliver_wk);
	} else if (test_sta_flag(sta, WLAN_STA_PSPOLL) ||
		   test_sta_flag(sta, WLAN_STA_UAPSD)) {
		/* must be asleep in this case */
		clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
		ieee80211_queue_work(hw, &sta->drv_deliver_wk);
	} else {
		clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
		ieee80211_check_fast_xmit(sta);
	}
}
EXPORT_SYMBOL(ieee80211_sta_block_awake);

void ieee80211_sta_eosp(struct ieee80211_sta *pubsta)
{
	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
	struct ieee80211_local *local = sta->local;

	trace_api_eosp(local, pubsta);

	clear_sta_flag(sta, WLAN_STA_SP);
}
EXPORT_SYMBOL(ieee80211_sta_eosp);

void ieee80211_send_eosp_nullfunc(struct ieee80211_sta *pubsta, int tid)
{
	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
	enum ieee80211_frame_release_type reason;
	bool more_data;

	trace_api_send_eosp_nullfunc(sta->local, pubsta, tid);

	reason = IEEE80211_FRAME_RELEASE_UAPSD;
	more_data = ieee80211_sta_ps_more_data(sta, ~sta->sta.uapsd_queues,
					       reason, 0);

	ieee80211_send_null_response(sta, tid, reason, false, more_data);
}
EXPORT_SYMBOL(ieee80211_send_eosp_nullfunc);

void ieee80211_sta_set_buffered(struct ieee80211_sta *pubsta,
				u8 tid, bool buffered)
{
	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);

	if (WARN_ON(tid >= IEEE80211_NUM_TIDS))
		return;

	trace_api_sta_set_buffered(sta->local, pubsta, tid, buffered);

	if (buffered)
		set_bit(tid, &sta->driver_buffered_tids);
	else
		clear_bit(tid, &sta->driver_buffered_tids);

	sta_info_recalc_tim(sta);
}
EXPORT_SYMBOL(ieee80211_sta_set_buffered);

static void
ieee80211_recalc_p2p_go_ps_allowed(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	bool allow_p2p_go_ps = sdata->vif.p2p;
	struct sta_info *sta;

	rcu_read_lock();
	list_for_each_entry_rcu(sta, &local->sta_list, list) {
		if (sdata != sta->sdata ||
		    !test_sta_flag(sta, WLAN_STA_ASSOC))
			continue;
		if (!sta->sta.support_p2p_ps) {
			allow_p2p_go_ps = false;
			break;
		}
	}
	rcu_read_unlock();

	if (allow_p2p_go_ps != sdata->vif.bss_conf.allow_p2p_go_ps) {
		sdata->vif.bss_conf.allow_p2p_go_ps = allow_p2p_go_ps;
		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_P2P_PS);
	}
}

int sta_info_move_state(struct sta_info *sta,
			enum ieee80211_sta_state new_state)
{
	might_sleep();

	if (sta->sta_state == new_state)
		return 0;

	/* check allowed transitions first */

	switch (new_state) {
	case IEEE80211_STA_NONE:
		if (sta->sta_state != IEEE80211_STA_AUTH)
			return -EINVAL;
		break;
	case IEEE80211_STA_AUTH:
		if (sta->sta_state != IEEE80211_STA_NONE &&
		    sta->sta_state != IEEE80211_STA_ASSOC)
			return -EINVAL;
		break;
	case IEEE80211_STA_ASSOC:
		if (sta->sta_state != IEEE80211_STA_AUTH &&
		    sta->sta_state != IEEE80211_STA_AUTHORIZED)
			return -EINVAL;
		break;
	case IEEE80211_STA_AUTHORIZED:
		if (sta->sta_state != IEEE80211_STA_ASSOC)
			return -EINVAL;
		break;
	default:
		WARN(1, "invalid state %d", new_state);
		return -EINVAL;
	}

	sta_dbg(sta->sdata, "moving STA %pM to state %d\n",
		sta->sta.addr, new_state);

	/*
	 * notify the driver before the actual changes so it can
	 * fail the transition
	 */
	if (test_sta_flag(sta, WLAN_STA_INSERTED)) {
		int err = drv_sta_state(sta->local, sta->sdata, sta,
					sta->sta_state, new_state);
		if (err)
			return err;
	}

	/* reflect the change in all state variables */

	switch (new_state) {
	case IEEE80211_STA_NONE:
		if (sta->sta_state == IEEE80211_STA_AUTH)
			clear_bit(WLAN_STA_AUTH, &sta->_flags);
		break;
	case IEEE80211_STA_AUTH:
		if (sta->sta_state == IEEE80211_STA_NONE) {
			set_bit(WLAN_STA_AUTH, &sta->_flags);
		} else if (sta->sta_state == IEEE80211_STA_ASSOC) {
			clear_bit(WLAN_STA_ASSOC, &sta->_flags);
			ieee80211_recalc_min_chandef(sta->sdata);
			if (!sta->sta.support_p2p_ps)
				ieee80211_recalc_p2p_go_ps_allowed(sta->sdata);
		}
		break;
	case IEEE80211_STA_ASSOC:
		if (sta->sta_state == IEEE80211_STA_AUTH) {
			set_bit(WLAN_STA_ASSOC, &sta->_flags);
			ieee80211_recalc_min_chandef(sta->sdata);
			if (!sta->sta.support_p2p_ps)
				ieee80211_recalc_p2p_go_ps_allowed(sta->sdata);
		} else if (sta->sta_state == IEEE80211_STA_AUTHORIZED) {
			ieee80211_vif_dec_num_mcast(sta->sdata);
			clear_bit(WLAN_STA_AUTHORIZED, &sta->_flags);
			ieee80211_clear_fast_xmit(sta);
			ieee80211_clear_fast_rx(sta);
		}
		break;
	case IEEE80211_STA_AUTHORIZED:
		if (sta->sta_state == IEEE80211_STA_ASSOC) {
			ieee80211_vif_inc_num_mcast(sta->sdata);
			set_bit(WLAN_STA_AUTHORIZED, &sta->_flags);
			ieee80211_check_fast_xmit(sta);
			ieee80211_check_fast_rx(sta);
		}
		break;
	default:
		break;
	}

	sta->sta_state = new_state;

	return 0;
}

u8 sta_info_tx_streams(struct sta_info *sta)
{
	struct ieee80211_sta_ht_cap *ht_cap = &sta->sta.ht_cap;
	u8 rx_streams;

	if (!sta->sta.ht_cap.ht_supported)
		return 1;

	if (sta->sta.vht_cap.vht_supported) {
		int i;
		u16 tx_mcs_map =
			le16_to_cpu(sta->sta.vht_cap.vht_mcs.tx_mcs_map);

		for (i = 7; i >= 0; i--)
			if ((tx_mcs_map & (0x3 << (i * 2))) !=
			    IEEE80211_VHT_MCS_NOT_SUPPORTED)
				return i + 1;
	}

	if (ht_cap->mcs.rx_mask[3])
		rx_streams = 4;
	else if (ht_cap->mcs.rx_mask[2])
		rx_streams = 3;
	else if (ht_cap->mcs.rx_mask[1])
		rx_streams = 2;
	else
		rx_streams = 1;

	if (!(ht_cap->mcs.tx_params & IEEE80211_HT_MCS_TX_RX_DIFF))
		return rx_streams;

	return ((ht_cap->mcs.tx_params & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
			>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
}

static struct ieee80211_sta_rx_stats *
sta_get_last_rx_stats(struct sta_info *sta)
{
	struct ieee80211_sta_rx_stats *stats = &sta->rx_stats;
	struct ieee80211_local *local = sta->local;
	int cpu;

	if (!ieee80211_hw_check(&local->hw, USES_RSS))
		return stats;

	for_each_possible_cpu(cpu) {
		struct ieee80211_sta_rx_stats *cpustats;

		cpustats = per_cpu_ptr(sta->pcpu_rx_stats, cpu);

		if (time_after(cpustats->last_rx, stats->last_rx))
			stats = cpustats;
	}

	return stats;
}

static void sta_stats_decode_rate(struct ieee80211_local *local, u16 rate,
				  struct rate_info *rinfo)
{
	rinfo->bw = (rate & STA_STATS_RATE_BW_MASK) >>
		STA_STATS_RATE_BW_SHIFT;

	if (rate & STA_STATS_RATE_VHT) {
		rinfo->flags = RATE_INFO_FLAGS_VHT_MCS;
		rinfo->mcs = rate & 0xf;
		rinfo->nss = (rate & 0xf0) >> 4;
	} else if (rate & STA_STATS_RATE_HT) {
		rinfo->flags = RATE_INFO_FLAGS_MCS;
		rinfo->mcs = rate & 0xff;
	} else if (rate & STA_STATS_RATE_LEGACY) {
		struct ieee80211_supported_band *sband;
		u16 brate;
		unsigned int shift;

		rinfo->flags = 0;
		sband = local->hw.wiphy->bands[(rate >> 4) & 0xf];
		brate = sband->bitrates[rate & 0xf].bitrate;
		if (rinfo->bw == RATE_INFO_BW_5)
			shift = 2;
		else if (rinfo->bw == RATE_INFO_BW_10)
			shift = 1;
		else
			shift = 0;
		rinfo->legacy = DIV_ROUND_UP(brate, 1 << shift);
	}

	if (rate & STA_STATS_RATE_SGI)
		rinfo->flags |= RATE_INFO_FLAGS_SHORT_GI;
}

static int sta_set_rate_info_rx(struct sta_info *sta, struct rate_info *rinfo)
{
	u16 rate = ACCESS_ONCE(sta_get_last_rx_stats(sta)->last_rate);

	if (rate == STA_STATS_RATE_INVALID)
		return -EINVAL;

	sta_stats_decode_rate(sta->local, rate, rinfo);
	return 0;
}

static void sta_set_tidstats(struct sta_info *sta,
			     struct cfg80211_tid_stats *tidstats,
			     int tid)
{
	struct ieee80211_local *local = sta->local;

	if (!(tidstats->filled & BIT(NL80211_TID_STATS_RX_MSDU))) {
		unsigned int start;

		do {
			start = u64_stats_fetch_begin(&sta->rx_stats.syncp);
			tidstats->rx_msdu = sta->rx_stats.msdu[tid];
		} while (u64_stats_fetch_retry(&sta->rx_stats.syncp, start));

		tidstats->filled |= BIT(NL80211_TID_STATS_RX_MSDU);
	}

	if (!(tidstats->filled & BIT(NL80211_TID_STATS_TX_MSDU))) {
		tidstats->filled |= BIT(NL80211_TID_STATS_TX_MSDU);
		tidstats->tx_msdu = sta->tx_stats.msdu[tid];
	}

	if (!(tidstats->filled & BIT(NL80211_TID_STATS_TX_MSDU_RETRIES)) &&
	    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS)) {
		tidstats->filled |= BIT(NL80211_TID_STATS_TX_MSDU_RETRIES);
		tidstats->tx_msdu_retries = sta->status_stats.msdu_retries[tid];
	}

	if (!(tidstats->filled & BIT(NL80211_TID_STATS_TX_MSDU_FAILED)) &&
	    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS)) {
		tidstats->filled |= BIT(NL80211_TID_STATS_TX_MSDU_FAILED);
		tidstats->tx_msdu_failed = sta->status_stats.msdu_failed[tid];
	}
}

static inline u64 sta_get_stats_bytes(struct ieee80211_sta_rx_stats *rxstats)
{
	unsigned int start;
	u64 value;

	do {
		start = u64_stats_fetch_begin(&rxstats->syncp);
		value = rxstats->bytes;
	} while (u64_stats_fetch_retry(&rxstats->syncp, start));

	return value;
}

void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct ieee80211_local *local = sdata->local;
	struct rate_control_ref *ref = NULL;
	u32 thr = 0;
	int i, ac, cpu;
	struct ieee80211_sta_rx_stats *last_rxstats;

	last_rxstats = sta_get_last_rx_stats(sta);

	if (test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
		ref = local->rate_ctrl;

	sinfo->generation = sdata->local->sta_generation;

	/* do before driver, so beacon filtering drivers have a
	 * chance to e.g. just add the number of filtered beacons
	 * (or just modify the value entirely, of course)
	 */
	if (sdata->vif.type == NL80211_IFTYPE_STATION)
		sinfo->rx_beacon = sdata->u.mgd.count_beacon_signal;

	drv_sta_statistics(local, sdata, &sta->sta, sinfo);

	sinfo->filled |= BIT(NL80211_STA_INFO_INACTIVE_TIME) |
			 BIT(NL80211_STA_INFO_STA_FLAGS) |
			 BIT(NL80211_STA_INFO_BSS_PARAM) |
			 BIT(NL80211_STA_INFO_CONNECTED_TIME) |
			 BIT(NL80211_STA_INFO_RX_DROP_MISC);

	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
		sinfo->beacon_loss_count = sdata->u.mgd.beacon_loss_count;
		sinfo->filled |= BIT(NL80211_STA_INFO_BEACON_LOSS);
	}

	sinfo->connected_time = ktime_get_seconds() - sta->last_connected;
	sinfo->inactive_time =
		jiffies_to_msecs(jiffies - ieee80211_sta_last_active(sta));

	if (!(sinfo->filled & (BIT(NL80211_STA_INFO_TX_BYTES64) |
			       BIT(NL80211_STA_INFO_TX_BYTES)))) {
		sinfo->tx_bytes = 0;
		for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
			sinfo->tx_bytes += sta->tx_stats.bytes[ac];
		sinfo->filled |= BIT(NL80211_STA_INFO_TX_BYTES64);
	}

	if (!(sinfo->filled & BIT(NL80211_STA_INFO_TX_PACKETS))) {
		sinfo->tx_packets = 0;
		for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
			sinfo->tx_packets += sta->tx_stats.packets[ac];
		sinfo->filled |= BIT(NL80211_STA_INFO_TX_PACKETS);
	}

	if (!(sinfo->filled & (BIT(NL80211_STA_INFO_RX_BYTES64) |
			       BIT(NL80211_STA_INFO_RX_BYTES)))) {
		sinfo->rx_bytes += sta_get_stats_bytes(&sta->rx_stats);

		if (sta->pcpu_rx_stats) {
			for_each_possible_cpu(cpu) {
				struct ieee80211_sta_rx_stats *cpurxs;

				cpurxs = per_cpu_ptr(sta->pcpu_rx_stats, cpu);
				sinfo->rx_bytes += sta_get_stats_bytes(cpurxs);
			}
		}

		sinfo->filled |= BIT(NL80211_STA_INFO_RX_BYTES64);
	}

	if (!(sinfo->filled & BIT(NL80211_STA_INFO_RX_PACKETS))) {
		sinfo->rx_packets = sta->rx_stats.packets;
		if (sta->pcpu_rx_stats) {
			for_each_possible_cpu(cpu) {
				struct ieee80211_sta_rx_stats *cpurxs;

				cpurxs = per_cpu_ptr(sta->pcpu_rx_stats, cpu);
				sinfo->rx_packets += cpurxs->packets;
			}
		}
		sinfo->filled |= BIT(NL80211_STA_INFO_RX_PACKETS);
	}

	if (!(sinfo->filled & BIT(NL80211_STA_INFO_TX_RETRIES))) {
		sinfo->tx_retries = sta->status_stats.retry_count;
		sinfo->filled |= BIT(NL80211_STA_INFO_TX_RETRIES);
	}

	if (!(sinfo->filled & BIT(NL80211_STA_INFO_TX_FAILED))) {
		sinfo->tx_failed = sta->status_stats.retry_failed;
		sinfo->filled |= BIT(NL80211_STA_INFO_TX_FAILED);
	}

	sinfo->rx_dropped_misc = sta->rx_stats.dropped;
	if (sta->pcpu_rx_stats) {
		for_each_possible_cpu(cpu) {
			struct ieee80211_sta_rx_stats *cpurxs;

			cpurxs = per_cpu_ptr(sta->pcpu_rx_stats, cpu);
			sinfo->rx_packets += cpurxs->dropped;
		}
	}

	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
	    !(sdata->vif.driver_flags & IEEE80211_VIF_BEACON_FILTER)) {
		sinfo->filled |= BIT(NL80211_STA_INFO_BEACON_RX) |
				 BIT(NL80211_STA_INFO_BEACON_SIGNAL_AVG);
		sinfo->rx_beacon_signal_avg = ieee80211_ave_rssi(&sdata->vif);
	}

	if (ieee80211_hw_check(&sta->local->hw, SIGNAL_DBM) ||
	    ieee80211_hw_check(&sta->local->hw, SIGNAL_UNSPEC)) {
		if (!(sinfo->filled & BIT(NL80211_STA_INFO_SIGNAL))) {
			sinfo->signal = (s8)last_rxstats->last_signal;
			sinfo->filled |= BIT(NL80211_STA_INFO_SIGNAL);
		}

		if (!sta->pcpu_rx_stats &&
		    !(sinfo->filled & BIT(NL80211_STA_INFO_SIGNAL_AVG))) {
			sinfo->signal_avg =
				-ewma_signal_read(&sta->rx_stats_avg.signal);
			sinfo->filled |= BIT(NL80211_STA_INFO_SIGNAL_AVG);
		}
	}

	/* for the average - if pcpu_rx_stats isn't set - rxstats must point to
	 * the sta->rx_stats struct, so the check here is fine with and without
	 * pcpu statistics
	 */
	if (last_rxstats->chains &&
	    !(sinfo->filled & (BIT(NL80211_STA_INFO_CHAIN_SIGNAL) |
			       BIT(NL80211_STA_INFO_CHAIN_SIGNAL_AVG)))) {
		sinfo->filled |= BIT(NL80211_STA_INFO_CHAIN_SIGNAL);
		if (!sta->pcpu_rx_stats)
			sinfo->filled |= BIT(NL80211_STA_INFO_CHAIN_SIGNAL_AVG);

		sinfo->chains = last_rxstats->chains;

		for (i = 0; i < ARRAY_SIZE(sinfo->chain_signal); i++) {
			sinfo->chain_signal[i] =
				last_rxstats->chain_signal_last[i];
			sinfo->chain_signal_avg[i] =
				-ewma_signal_read(&sta->rx_stats_avg.chain_signal[i]);
		}
	}

	if (!(sinfo->filled & BIT(NL80211_STA_INFO_TX_BITRATE))) {
		sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate,
				     &sinfo->txrate);
		sinfo->filled |= BIT(NL80211_STA_INFO_TX_BITRATE);
	}

	if (!(sinfo->filled & BIT(NL80211_STA_INFO_RX_BITRATE))) {
		if (sta_set_rate_info_rx(sta, &sinfo->rxrate) == 0)
			sinfo->filled |= BIT(NL80211_STA_INFO_RX_BITRATE);
	}

	sinfo->filled |= BIT(NL80211_STA_INFO_TID_STATS);
	for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++) {
		struct cfg80211_tid_stats *tidstats = &sinfo->pertid[i];

		sta_set_tidstats(sta, tidstats, i);
	}

	if (ieee80211_vif_is_mesh(&sdata->vif)) {
#ifdef CONFIG_MAC80211_MESH
		sinfo->filled |= BIT(NL80211_STA_INFO_LLID) |
				 BIT(NL80211_STA_INFO_PLID) |
				 BIT(NL80211_STA_INFO_PLINK_STATE) |
				 BIT(NL80211_STA_INFO_LOCAL_PM) |
				 BIT(NL80211_STA_INFO_PEER_PM) |
				 BIT(NL80211_STA_INFO_NONPEER_PM);

		sinfo->llid = sta->mesh->llid;
		sinfo->plid = sta->mesh->plid;
		sinfo->plink_state = sta->mesh->plink_state;
		if (test_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN)) {
			sinfo->filled |= BIT(NL80211_STA_INFO_T_OFFSET);
			sinfo->t_offset = sta->mesh->t_offset;
		}
		sinfo->local_pm = sta->mesh->local_pm;
		sinfo->peer_pm = sta->mesh->peer_pm;
		sinfo->nonpeer_pm = sta->mesh->nonpeer_pm;
#endif
	}

	sinfo->bss_param.flags = 0;
	if (sdata->vif.bss_conf.use_cts_prot)
		sinfo->bss_param.flags |= BSS_PARAM_FLAGS_CTS_PROT;
	if (sdata->vif.bss_conf.use_short_preamble)
		sinfo->bss_param.flags |= BSS_PARAM_FLAGS_SHORT_PREAMBLE;
	if (sdata->vif.bss_conf.use_short_slot)
		sinfo->bss_param.flags |= BSS_PARAM_FLAGS_SHORT_SLOT_TIME;
	sinfo->bss_param.dtim_period = sdata->vif.bss_conf.dtim_period;
	sinfo->bss_param.beacon_interval = sdata->vif.bss_conf.beacon_int;

	sinfo->sta_flags.set = 0;
	sinfo->sta_flags.mask = BIT(NL80211_STA_FLAG_AUTHORIZED) |
				BIT(NL80211_STA_FLAG_SHORT_PREAMBLE) |
				BIT(NL80211_STA_FLAG_WME) |
				BIT(NL80211_STA_FLAG_MFP) |
				BIT(NL80211_STA_FLAG_AUTHENTICATED) |
				BIT(NL80211_STA_FLAG_ASSOCIATED) |
				BIT(NL80211_STA_FLAG_TDLS_PEER);
	if (test_sta_flag(sta, WLAN_STA_AUTHORIZED))
		sinfo->sta_flags.set |= BIT(NL80211_STA_FLAG_AUTHORIZED);
	if (test_sta_flag(sta, WLAN_STA_SHORT_PREAMBLE))
		sinfo->sta_flags.set |= BIT(NL80211_STA_FLAG_SHORT_PREAMBLE);
	if (sta->sta.wme)
		sinfo->sta_flags.set |= BIT(NL80211_STA_FLAG_WME);
	if (test_sta_flag(sta, WLAN_STA_MFP))
		sinfo->sta_flags.set |= BIT(NL80211_STA_FLAG_MFP);
	if (test_sta_flag(sta, WLAN_STA_AUTH))
		sinfo->sta_flags.set |= BIT(NL80211_STA_FLAG_AUTHENTICATED);
	if (test_sta_flag(sta, WLAN_STA_ASSOC))
		sinfo->sta_flags.set |= BIT(NL80211_STA_FLAG_ASSOCIATED);
	if (test_sta_flag(sta, WLAN_STA_TDLS_PEER))
		sinfo->sta_flags.set |= BIT(NL80211_STA_FLAG_TDLS_PEER);

	thr = sta_get_expected_throughput(sta);

	if (thr != 0) {
		sinfo->filled |= BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT);
		sinfo->expected_throughput = thr;
	}
}

u32 sta_get_expected_throughput(struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct ieee80211_local *local = sdata->local;
	struct rate_control_ref *ref = NULL;
	u32 thr = 0;

	if (test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
		ref = local->rate_ctrl;

	/* check if the driver has a SW RC implementation */
	if (ref && ref->ops->get_expected_throughput)
		thr = ref->ops->get_expected_throughput(sta->rate_ctrl_priv);
	else
		thr = drv_get_expected_throughput(local, sta);

	return thr;
}

unsigned long ieee80211_sta_last_active(struct sta_info *sta)
{
	struct ieee80211_sta_rx_stats *stats = sta_get_last_rx_stats(sta);

	if (time_after(stats->last_rx, sta->status_stats.last_ack))
		return stats->last_rx;
	return sta->status_stats.last_ack;
}