summaryrefslogtreecommitdiff
path: root/drivers/net/wireless/intel/iwlwifi/mei/main.c
blob: 67dfb77fedf7951b49d30f3a385613696dc0d657 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2021-2022 Intel Corporation
 */

#include <linux/etherdevice.h>
#include <linux/netdevice.h>
#include <linux/ieee80211.h>
#include <linux/rtnetlink.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mei_cl_bus.h>
#include <linux/rcupdate.h>
#include <linux/debugfs.h>
#include <linux/skbuff.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/mm.h>

#include <net/cfg80211.h>

#include "internal.h"
#include "iwl-mei.h"
#include "trace.h"
#include "trace-data.h"
#include "sap.h"

MODULE_DESCRIPTION("The Intel(R) wireless / CSME firmware interface");
MODULE_LICENSE("GPL");

#define MEI_WLAN_UUID UUID_LE(0x13280904, 0x7792, 0x4fcb, \
			      0xa1, 0xaa, 0x5e, 0x70, 0xcb, 0xb1, 0xe8, 0x65)

/*
 * Since iwlwifi calls iwlmei without any context, hold a pointer to the
 * mei_cl_device structure here.
 * Define a mutex that will synchronize all the flows between iwlwifi and
 * iwlmei.
 * Note that iwlmei can't have several instances, so it ok to have static
 * variables here.
 */
static struct mei_cl_device *iwl_mei_global_cldev;
static DEFINE_MUTEX(iwl_mei_mutex);
static unsigned long iwl_mei_status;

enum iwl_mei_status_bits {
	IWL_MEI_STATUS_SAP_CONNECTED,
};

bool iwl_mei_is_connected(void)
{
	return test_bit(IWL_MEI_STATUS_SAP_CONNECTED, &iwl_mei_status);
}
EXPORT_SYMBOL_GPL(iwl_mei_is_connected);

#define SAP_VERSION	3
#define SAP_CONTROL_BLOCK_ID 0x21504153 /* SAP! in ASCII */

struct iwl_sap_q_ctrl_blk {
	__le32 wr_ptr;
	__le32 rd_ptr;
	__le32 size;
};

enum iwl_sap_q_idx {
	SAP_QUEUE_IDX_NOTIF = 0,
	SAP_QUEUE_IDX_DATA,
	SAP_QUEUE_IDX_MAX,
};

struct iwl_sap_dir {
	__le32 reserved;
	struct iwl_sap_q_ctrl_blk q_ctrl_blk[SAP_QUEUE_IDX_MAX];
};

enum iwl_sap_dir_idx {
	SAP_DIRECTION_HOST_TO_ME = 0,
	SAP_DIRECTION_ME_TO_HOST,
	SAP_DIRECTION_MAX,
};

struct iwl_sap_shared_mem_ctrl_blk {
	__le32 sap_id;
	__le32 size;
	struct iwl_sap_dir dir[SAP_DIRECTION_MAX];
};

/*
 * The shared area has the following layout:
 *
 * +-----------------------------------+
 * |struct iwl_sap_shared_mem_ctrl_blk |
 * +-----------------------------------+
 * |Host -> ME data queue              |
 * +-----------------------------------+
 * |Host -> ME notif queue             |
 * +-----------------------------------+
 * |ME -> Host data queue              |
 * +-----------------------------------+
 * |ME -> host notif queue             |
 * +-----------------------------------+
 * |SAP control block id (SAP!)        |
 * +-----------------------------------+
 */

#define SAP_H2M_DATA_Q_SZ	48256
#define SAP_M2H_DATA_Q_SZ	24128
#define SAP_H2M_NOTIF_Q_SZ	2240
#define SAP_M2H_NOTIF_Q_SZ	62720

#define _IWL_MEI_SAP_SHARED_MEM_SZ \
	(sizeof(struct iwl_sap_shared_mem_ctrl_blk) + \
	 SAP_H2M_DATA_Q_SZ + SAP_H2M_NOTIF_Q_SZ + \
	 SAP_M2H_DATA_Q_SZ + SAP_M2H_NOTIF_Q_SZ + 4)

#define IWL_MEI_SAP_SHARED_MEM_SZ \
	(roundup(_IWL_MEI_SAP_SHARED_MEM_SZ, PAGE_SIZE))

struct iwl_mei_shared_mem_ptrs {
	struct iwl_sap_shared_mem_ctrl_blk *ctrl;
	void *q_head[SAP_DIRECTION_MAX][SAP_QUEUE_IDX_MAX];
	size_t q_size[SAP_DIRECTION_MAX][SAP_QUEUE_IDX_MAX];
};

struct iwl_mei_filters {
	struct rcu_head rcu_head;
	struct iwl_sap_oob_filters filters;
};

/**
 * struct iwl_mei - holds the private date for iwl_mei
 *
 * @get_nvm_wq: the wait queue for the get_nvm flow
 * @send_csa_msg_wk: used to defer the transmission of the CHECK_SHARED_AREA
 *	message. Used so that we can send CHECK_SHARED_AREA from atomic
 *	contexts.
 * @get_ownership_wq: the wait queue for the get_ownership_flow
 * @shared_mem: the memory that is shared between CSME and the host
 * @cldev: the pointer to the MEI client device
 * @nvm: the data returned by the CSME for the NVM
 * @filters: the filters sent by CSME
 * @got_ownership: true if we own the device
 * @amt_enabled: true if CSME has wireless enabled
 * @csa_throttled: when true, we can't send CHECK_SHARED_AREA over the MEI
 *	bus, but rather need to wait until send_csa_msg_wk runs
 * @csme_taking_ownership: true when CSME is taking ownership. Used to remember
 *	to send CSME_OWNERSHIP_CONFIRMED when the driver completes its down
 *	flow.
 * @link_prot_state: true when we are in link protection PASSIVE
 * @device_down: true if the device is down. Used to remember to send
 *	CSME_OWNERSHIP_CONFIRMED when the driver is already down.
 * @csa_throttle_end_wk: used when &csa_throttled is true
 * @pldr_wq: the wait queue for PLDR flow
 * @pldr_active: PLDR flow is in progress
 * @data_q_lock: protects the access to the data queues which are
 *	accessed without the mutex.
 * @netdev_work: used to defer registering and unregistering of the netdev to
 *	avoid taking the rtnl lock in the SAP messages handlers.
 * @sap_seq_no: the sequence number for the SAP messages
 * @seq_no: the sequence number for the SAP messages
 * @dbgfs_dir: the debugfs dir entry
 */
struct iwl_mei {
	wait_queue_head_t get_nvm_wq;
	struct work_struct send_csa_msg_wk;
	wait_queue_head_t get_ownership_wq;
	struct iwl_mei_shared_mem_ptrs shared_mem;
	struct mei_cl_device *cldev;
	struct iwl_mei_nvm *nvm;
	struct iwl_mei_filters __rcu *filters;
	bool got_ownership;
	bool amt_enabled;
	bool csa_throttled;
	bool csme_taking_ownership;
	bool link_prot_state;
	bool device_down;
	struct delayed_work csa_throttle_end_wk;
	wait_queue_head_t pldr_wq;
	bool pldr_active;
	spinlock_t data_q_lock;
	struct work_struct netdev_work;

	atomic_t sap_seq_no;
	atomic_t seq_no;

	struct dentry *dbgfs_dir;
};

/**
 * struct iwl_mei_cache - cache for the parameters from iwlwifi
 * @ops: Callbacks to iwlwifi.
 * @netdev: The netdev that will be used to transmit / receive packets.
 * @conn_info: The connection info message triggered by iwlwifi's association.
 * @power_limit: pointer to an array of 10 elements (le16) represents the power
 *	restrictions per chain.
 * @rf_kill: rf kill state.
 * @mcc: MCC info
 * @mac_address: interface MAC address.
 * @nvm_address: NVM MAC address.
 * @priv: A pointer to iwlwifi.
 *
 * This used to cache the configurations coming from iwlwifi's way. The data
 * is cached here so that we can buffer the configuration even if we don't have
 * a bind from the mei bus and hence, on iwl_mei structure.
 */
struct iwl_mei_cache {
	const struct iwl_mei_ops *ops;
	struct net_device __rcu *netdev;
	const struct iwl_sap_notif_connection_info *conn_info;
	const __le16 *power_limit;
	u32 rf_kill;
	u16 mcc;
	u8 mac_address[6];
	u8 nvm_address[6];
	void *priv;
};

static struct iwl_mei_cache iwl_mei_cache = {
	.rf_kill = SAP_HW_RFKILL_DEASSERTED | SAP_SW_RFKILL_DEASSERTED
};

static void iwl_mei_free_shared_mem(struct mei_cl_device *cldev)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);

	if (mei_cldev_dma_unmap(cldev))
		dev_err(&cldev->dev, "Couldn't unmap the shared mem properly\n");
	memset(&mei->shared_mem, 0, sizeof(mei->shared_mem));
}

#define HBM_DMA_BUF_ID_WLAN 1

static int iwl_mei_alloc_shared_mem(struct mei_cl_device *cldev)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
	struct iwl_mei_shared_mem_ptrs *mem = &mei->shared_mem;

	mem->ctrl = mei_cldev_dma_map(cldev, HBM_DMA_BUF_ID_WLAN,
				       IWL_MEI_SAP_SHARED_MEM_SZ);

	if (IS_ERR(mem->ctrl)) {
		int ret = PTR_ERR(mem->ctrl);

		mem->ctrl = NULL;

		return ret;
	}

	memset(mem->ctrl, 0, IWL_MEI_SAP_SHARED_MEM_SZ);

	return 0;
}

static void iwl_mei_init_shared_mem(struct iwl_mei *mei)
{
	struct iwl_mei_shared_mem_ptrs *mem = &mei->shared_mem;
	struct iwl_sap_dir *h2m;
	struct iwl_sap_dir *m2h;
	int dir, queue;
	u8 *q_head;

	mem->ctrl->sap_id = cpu_to_le32(SAP_CONTROL_BLOCK_ID);

	mem->ctrl->size = cpu_to_le32(sizeof(*mem->ctrl));

	h2m = &mem->ctrl->dir[SAP_DIRECTION_HOST_TO_ME];
	m2h = &mem->ctrl->dir[SAP_DIRECTION_ME_TO_HOST];

	h2m->q_ctrl_blk[SAP_QUEUE_IDX_DATA].size =
		cpu_to_le32(SAP_H2M_DATA_Q_SZ);
	h2m->q_ctrl_blk[SAP_QUEUE_IDX_NOTIF].size =
		cpu_to_le32(SAP_H2M_NOTIF_Q_SZ);
	m2h->q_ctrl_blk[SAP_QUEUE_IDX_DATA].size =
		cpu_to_le32(SAP_M2H_DATA_Q_SZ);
	m2h->q_ctrl_blk[SAP_QUEUE_IDX_NOTIF].size =
		cpu_to_le32(SAP_M2H_NOTIF_Q_SZ);

	/* q_head points to the start of the first queue */
	q_head = (void *)(mem->ctrl + 1);

	/* Initialize the queue heads */
	for (dir = 0; dir < SAP_DIRECTION_MAX; dir++) {
		for (queue = 0; queue < SAP_QUEUE_IDX_MAX; queue++) {
			mem->q_head[dir][queue] = q_head;
			q_head +=
				le32_to_cpu(mem->ctrl->dir[dir].q_ctrl_blk[queue].size);
			mem->q_size[dir][queue] =
				le32_to_cpu(mem->ctrl->dir[dir].q_ctrl_blk[queue].size);
		}
	}

	*(__le32 *)q_head = cpu_to_le32(SAP_CONTROL_BLOCK_ID);
}

static ssize_t iwl_mei_write_cyclic_buf(struct mei_cl_device *cldev,
					struct iwl_sap_q_ctrl_blk *notif_q,
					u8 *q_head,
					const struct iwl_sap_hdr *hdr,
					u32 q_sz)
{
	u32 rd = le32_to_cpu(READ_ONCE(notif_q->rd_ptr));
	u32 wr = le32_to_cpu(READ_ONCE(notif_q->wr_ptr));
	size_t room_in_buf;
	size_t tx_sz = sizeof(*hdr) + le16_to_cpu(hdr->len);

	if (rd > q_sz || wr > q_sz) {
		dev_err(&cldev->dev,
			"Pointers are past the end of the buffer\n");
		return -EINVAL;
	}

	room_in_buf = wr >= rd ? q_sz - wr + rd : rd - wr;

	/* we don't have enough room for the data to write */
	if (room_in_buf < tx_sz) {
		dev_err(&cldev->dev,
			"Not enough room in the buffer\n");
		return -ENOSPC;
	}

	if (wr + tx_sz <= q_sz) {
		memcpy(q_head + wr, hdr, tx_sz);
	} else {
		memcpy(q_head + wr, hdr, q_sz - wr);
		memcpy(q_head, (const u8 *)hdr + q_sz - wr, tx_sz - (q_sz - wr));
	}

	WRITE_ONCE(notif_q->wr_ptr, cpu_to_le32((wr + tx_sz) % q_sz));
	return 0;
}

static bool iwl_mei_host_to_me_data_pending(const struct iwl_mei *mei)
{
	struct iwl_sap_q_ctrl_blk *notif_q;
	struct iwl_sap_dir *dir;

	dir = &mei->shared_mem.ctrl->dir[SAP_DIRECTION_HOST_TO_ME];
	notif_q = &dir->q_ctrl_blk[SAP_QUEUE_IDX_DATA];

	if (READ_ONCE(notif_q->wr_ptr) != READ_ONCE(notif_q->rd_ptr))
		return true;

	notif_q = &dir->q_ctrl_blk[SAP_QUEUE_IDX_NOTIF];
	return READ_ONCE(notif_q->wr_ptr) != READ_ONCE(notif_q->rd_ptr);
}

static int iwl_mei_send_check_shared_area(struct mei_cl_device *cldev)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
	struct iwl_sap_me_msg_start msg = {
		.hdr.type = cpu_to_le32(SAP_ME_MSG_CHECK_SHARED_AREA),
		.hdr.seq_num = cpu_to_le32(atomic_inc_return(&mei->seq_no)),
	};
	int ret;

	lockdep_assert_held(&iwl_mei_mutex);

	if (mei->csa_throttled)
		return 0;

	trace_iwlmei_me_msg(&msg.hdr, true);
	ret = mei_cldev_send(cldev, (void *)&msg, sizeof(msg));
	if (ret != sizeof(msg)) {
		dev_err(&cldev->dev,
			"failed to send the SAP_ME_MSG_CHECK_SHARED_AREA message %d\n",
			ret);
		return ret;
	}

	mei->csa_throttled = true;

	schedule_delayed_work(&mei->csa_throttle_end_wk,
			      msecs_to_jiffies(100));

	return 0;
}

static void iwl_mei_csa_throttle_end_wk(struct work_struct *wk)
{
	struct iwl_mei *mei =
		container_of(wk, struct iwl_mei, csa_throttle_end_wk.work);

	mutex_lock(&iwl_mei_mutex);

	mei->csa_throttled = false;

	if (iwl_mei_host_to_me_data_pending(mei))
		iwl_mei_send_check_shared_area(mei->cldev);

	mutex_unlock(&iwl_mei_mutex);
}

static int iwl_mei_send_sap_msg_payload(struct mei_cl_device *cldev,
					struct iwl_sap_hdr *hdr)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
	struct iwl_sap_q_ctrl_blk *notif_q;
	struct iwl_sap_dir *dir;
	void *q_head;
	u32 q_sz;
	int ret;

	lockdep_assert_held(&iwl_mei_mutex);

	if (!mei->shared_mem.ctrl) {
		dev_err(&cldev->dev,
			"No shared memory, can't send any SAP message\n");
		return -EINVAL;
	}

	if (!iwl_mei_is_connected()) {
		dev_err(&cldev->dev,
			"Can't send a SAP message if we're not connected\n");
		return -ENODEV;
	}

	hdr->seq_num = cpu_to_le32(atomic_inc_return(&mei->sap_seq_no));
	dev_dbg(&cldev->dev, "Sending %d\n", hdr->type);

	dir = &mei->shared_mem.ctrl->dir[SAP_DIRECTION_HOST_TO_ME];
	notif_q = &dir->q_ctrl_blk[SAP_QUEUE_IDX_NOTIF];
	q_head = mei->shared_mem.q_head[SAP_DIRECTION_HOST_TO_ME][SAP_QUEUE_IDX_NOTIF];
	q_sz = mei->shared_mem.q_size[SAP_DIRECTION_HOST_TO_ME][SAP_QUEUE_IDX_NOTIF];
	ret = iwl_mei_write_cyclic_buf(q_head, notif_q, q_head, hdr, q_sz);

	if (ret < 0)
		return ret;

	trace_iwlmei_sap_cmd(hdr, true);

	return iwl_mei_send_check_shared_area(cldev);
}

void iwl_mei_add_data_to_ring(struct sk_buff *skb, bool cb_tx)
{
	struct iwl_sap_q_ctrl_blk *notif_q;
	struct iwl_sap_dir *dir;
	struct iwl_mei *mei;
	size_t room_in_buf;
	size_t tx_sz;
	size_t hdr_sz;
	u32 q_sz;
	u32 rd;
	u32 wr;
	u8 *q_head;

	if (!iwl_mei_global_cldev)
		return;

	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);

	/*
	 * We access this path for Rx packets (the more common case)
	 * and from Tx path when we send DHCP packets, the latter is
	 * very unlikely.
	 * Take the lock already here to make sure we see that remove()
	 * might have cleared the IWL_MEI_STATUS_SAP_CONNECTED bit.
	 */
	spin_lock_bh(&mei->data_q_lock);

	if (!iwl_mei_is_connected()) {
		spin_unlock_bh(&mei->data_q_lock);
		return;
	}

	/*
	 * We are in a RCU critical section and the remove from the CSME bus
	 * which would free this memory waits for the readers to complete (this
	 * is done in netdev_rx_handler_unregister).
	 */
	dir = &mei->shared_mem.ctrl->dir[SAP_DIRECTION_HOST_TO_ME];
	notif_q = &dir->q_ctrl_blk[SAP_QUEUE_IDX_DATA];
	q_head = mei->shared_mem.q_head[SAP_DIRECTION_HOST_TO_ME][SAP_QUEUE_IDX_DATA];
	q_sz = mei->shared_mem.q_size[SAP_DIRECTION_HOST_TO_ME][SAP_QUEUE_IDX_DATA];

	rd = le32_to_cpu(READ_ONCE(notif_q->rd_ptr));
	wr = le32_to_cpu(READ_ONCE(notif_q->wr_ptr));
	hdr_sz = cb_tx ? sizeof(struct iwl_sap_cb_data) :
			 sizeof(struct iwl_sap_hdr);
	tx_sz = skb->len + hdr_sz;

	if (rd > q_sz || wr > q_sz) {
		dev_err(&mei->cldev->dev,
			"can't write the data: pointers are past the end of the buffer\n");
		goto out;
	}

	room_in_buf = wr >= rd ? q_sz - wr + rd : rd - wr;

	/* we don't have enough room for the data to write */
	if (room_in_buf < tx_sz) {
		dev_err(&mei->cldev->dev,
			"Not enough room in the buffer for this data\n");
		goto out;
	}

	if (skb_headroom(skb) < hdr_sz) {
		dev_err(&mei->cldev->dev,
			"Not enough headroom in the skb to write the SAP header\n");
		goto out;
	}

	if (cb_tx) {
		struct iwl_sap_cb_data *cb_hdr = skb_push(skb, sizeof(*cb_hdr));

		memset(cb_hdr, 0, sizeof(*cb_hdr));
		cb_hdr->hdr.type = cpu_to_le16(SAP_MSG_CB_DATA_PACKET);
		cb_hdr->hdr.len = cpu_to_le16(skb->len - sizeof(cb_hdr->hdr));
		cb_hdr->hdr.seq_num = cpu_to_le32(atomic_inc_return(&mei->sap_seq_no));
		cb_hdr->to_me_filt_status = cpu_to_le32(BIT(CB_TX_DHCP_FILT_IDX));
		cb_hdr->data_len = cpu_to_le32(skb->len - sizeof(*cb_hdr));
		trace_iwlmei_sap_data(skb, IWL_SAP_TX_DHCP);
	} else {
		struct iwl_sap_hdr *hdr = skb_push(skb, sizeof(*hdr));

		hdr->type = cpu_to_le16(SAP_MSG_DATA_PACKET);
		hdr->len = cpu_to_le16(skb->len - sizeof(*hdr));
		hdr->seq_num = cpu_to_le32(atomic_inc_return(&mei->sap_seq_no));
		trace_iwlmei_sap_data(skb, IWL_SAP_TX_DATA_FROM_AIR);
	}

	if (wr + tx_sz <= q_sz) {
		skb_copy_bits(skb, 0, q_head + wr, tx_sz);
	} else {
		skb_copy_bits(skb, 0, q_head + wr, q_sz - wr);
		skb_copy_bits(skb, q_sz - wr, q_head, tx_sz - (q_sz - wr));
	}

	WRITE_ONCE(notif_q->wr_ptr, cpu_to_le32((wr + tx_sz) % q_sz));

out:
	spin_unlock_bh(&mei->data_q_lock);
}

static int
iwl_mei_send_sap_msg(struct mei_cl_device *cldev, u16 type)
{
	struct iwl_sap_hdr msg = {
		.type = cpu_to_le16(type),
	};

	return iwl_mei_send_sap_msg_payload(cldev, &msg);
}

static void iwl_mei_send_csa_msg_wk(struct work_struct *wk)
{
	struct iwl_mei *mei =
		container_of(wk, struct iwl_mei, send_csa_msg_wk);

	if (!iwl_mei_is_connected())
		return;

	mutex_lock(&iwl_mei_mutex);

	iwl_mei_send_check_shared_area(mei->cldev);

	mutex_unlock(&iwl_mei_mutex);
}

/* Called in a RCU read critical section from netif_receive_skb */
static rx_handler_result_t iwl_mei_rx_handler(struct sk_buff **pskb)
{
	struct sk_buff *skb = *pskb;
	struct iwl_mei *mei =
		rcu_dereference(skb->dev->rx_handler_data);
	struct iwl_mei_filters *filters = rcu_dereference(mei->filters);
	bool rx_for_csme = false;
	rx_handler_result_t res;

	/*
	 * remove() unregisters this handler and synchronize_net, so this
	 * should never happen.
	 */
	if (!iwl_mei_is_connected()) {
		dev_err(&mei->cldev->dev,
			"Got an Rx packet, but we're not connected to SAP?\n");
		return RX_HANDLER_PASS;
	}

	if (filters)
		res = iwl_mei_rx_filter(skb, &filters->filters, &rx_for_csme);
	else
		res = RX_HANDLER_PASS;

	/*
	 * The data is already on the ring of the shared area, all we
	 * need to do is to tell the CSME firmware to check what we have
	 * there.
	 */
	if (rx_for_csme)
		schedule_work(&mei->send_csa_msg_wk);

	if (res != RX_HANDLER_PASS) {
		trace_iwlmei_sap_data(skb, IWL_SAP_RX_DATA_DROPPED_FROM_AIR);
		dev_kfree_skb(skb);
	}

	return res;
}

static void iwl_mei_netdev_work(struct work_struct *wk)
{
	struct iwl_mei *mei =
		container_of(wk, struct iwl_mei, netdev_work);
	struct net_device *netdev;

	/*
	 * First take rtnl and only then the mutex to avoid an ABBA
	 * with iwl_mei_set_netdev()
	 */
	rtnl_lock();
	mutex_lock(&iwl_mei_mutex);

	netdev = rcu_dereference_protected(iwl_mei_cache.netdev,
					   lockdep_is_held(&iwl_mei_mutex));
	if (netdev) {
		if (mei->amt_enabled)
			netdev_rx_handler_register(netdev, iwl_mei_rx_handler,
						   mei);
		else
			netdev_rx_handler_unregister(netdev);
	}

	mutex_unlock(&iwl_mei_mutex);
	rtnl_unlock();
}

static void
iwl_mei_handle_rx_start_ok(struct mei_cl_device *cldev,
			   const struct iwl_sap_me_msg_start_ok *rsp,
			   ssize_t len)
{
	if (len != sizeof(*rsp)) {
		dev_err(&cldev->dev,
			"got invalid SAP_ME_MSG_START_OK from CSME firmware\n");
		dev_err(&cldev->dev,
			"size is incorrect: %zd instead of %zu\n",
			len, sizeof(*rsp));
		return;
	}

	if (rsp->supported_version != SAP_VERSION) {
		dev_err(&cldev->dev,
			"didn't get the expected version: got %d\n",
			rsp->supported_version);
		return;
	}

	mutex_lock(&iwl_mei_mutex);
	set_bit(IWL_MEI_STATUS_SAP_CONNECTED, &iwl_mei_status);
	/*
	 * We'll receive AMT_STATE SAP message in a bit and
	 * that will continue the flow
	 */
	mutex_unlock(&iwl_mei_mutex);
}

static void iwl_mei_handle_csme_filters(struct mei_cl_device *cldev,
					const struct iwl_sap_csme_filters *filters)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
	struct iwl_mei_filters *new_filters;
	struct iwl_mei_filters *old_filters;

	old_filters =
		rcu_dereference_protected(mei->filters,
					  lockdep_is_held(&iwl_mei_mutex));

	new_filters = kzalloc(sizeof(*new_filters), GFP_KERNEL);
	if (!new_filters)
		return;

	/* Copy the OOB filters */
	new_filters->filters = filters->filters;

	rcu_assign_pointer(mei->filters, new_filters);

	if (old_filters)
		kfree_rcu(old_filters, rcu_head);
}

static void
iwl_mei_handle_conn_status(struct mei_cl_device *cldev,
			   const struct iwl_sap_notif_conn_status *status)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
	struct iwl_mei_conn_info conn_info = {
		.lp_state = le32_to_cpu(status->link_prot_state),
		.ssid_len = le32_to_cpu(status->conn_info.ssid_len),
		.channel = status->conn_info.channel,
		.band = status->conn_info.band,
		.auth_mode = le32_to_cpu(status->conn_info.auth_mode),
		.pairwise_cipher = le32_to_cpu(status->conn_info.pairwise_cipher),
	};

	if (!iwl_mei_cache.ops ||
	    conn_info.ssid_len > ARRAY_SIZE(conn_info.ssid))
		return;

	memcpy(conn_info.ssid, status->conn_info.ssid, conn_info.ssid_len);
	ether_addr_copy(conn_info.bssid, status->conn_info.bssid);

	iwl_mei_cache.ops->me_conn_status(iwl_mei_cache.priv, &conn_info);

	mei->link_prot_state = status->link_prot_state;

	/*
	 * Update the Rfkill state in case the host does not own the device:
	 * if we are in Link Protection, ask to not touch the device, else,
	 * unblock rfkill.
	 * If the host owns the device, inform the user space whether it can
	 * roam.
	 */
	if (mei->got_ownership)
		iwl_mei_cache.ops->roaming_forbidden(iwl_mei_cache.priv,
						     status->link_prot_state);
	else
		iwl_mei_cache.ops->rfkill(iwl_mei_cache.priv,
					  status->link_prot_state);
}

static void iwl_mei_set_init_conf(struct iwl_mei *mei)
{
	struct iwl_sap_notif_host_link_up link_msg = {
		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_HOST_LINK_UP),
		.hdr.len = cpu_to_le16(sizeof(link_msg) - sizeof(link_msg.hdr)),
	};
	struct iwl_sap_notif_country_code mcc_msg = {
		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_COUNTRY_CODE),
		.hdr.len = cpu_to_le16(sizeof(mcc_msg) - sizeof(mcc_msg.hdr)),
		.mcc = cpu_to_le16(iwl_mei_cache.mcc),
	};
	struct iwl_sap_notif_sar_limits sar_msg = {
		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_SAR_LIMITS),
		.hdr.len = cpu_to_le16(sizeof(sar_msg) - sizeof(sar_msg.hdr)),
	};
	struct iwl_sap_notif_host_nic_info nic_info_msg = {
		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_NIC_INFO),
		.hdr.len = cpu_to_le16(sizeof(nic_info_msg) - sizeof(nic_info_msg.hdr)),
	};
	struct iwl_sap_msg_dw rfkill_msg = {
		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_RADIO_STATE),
		.hdr.len = cpu_to_le16(sizeof(rfkill_msg) - sizeof(rfkill_msg.hdr)),
		.val = cpu_to_le32(iwl_mei_cache.rf_kill),
	};

	/* wifi driver has registered already */
	if (iwl_mei_cache.ops) {
		iwl_mei_send_sap_msg(mei->cldev,
				     SAP_MSG_NOTIF_WIFIDR_UP);
		iwl_mei_cache.ops->sap_connected(iwl_mei_cache.priv);
	}

	iwl_mei_send_sap_msg(mei->cldev, SAP_MSG_NOTIF_WHO_OWNS_NIC);

	if (iwl_mei_cache.conn_info) {
		link_msg.conn_info = *iwl_mei_cache.conn_info;
		iwl_mei_send_sap_msg_payload(mei->cldev, &link_msg.hdr);
	}

	iwl_mei_send_sap_msg_payload(mei->cldev, &mcc_msg.hdr);

	if (iwl_mei_cache.power_limit) {
		memcpy(sar_msg.sar_chain_info_table, iwl_mei_cache.power_limit,
		       sizeof(sar_msg.sar_chain_info_table));
		iwl_mei_send_sap_msg_payload(mei->cldev, &sar_msg.hdr);
	}

	ether_addr_copy(nic_info_msg.mac_address, iwl_mei_cache.mac_address);
	ether_addr_copy(nic_info_msg.nvm_address, iwl_mei_cache.nvm_address);
	iwl_mei_send_sap_msg_payload(mei->cldev, &nic_info_msg.hdr);

	iwl_mei_send_sap_msg_payload(mei->cldev, &rfkill_msg.hdr);
}

static void iwl_mei_handle_amt_state(struct mei_cl_device *cldev,
				     const struct iwl_sap_msg_dw *dw)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);

	mutex_lock(&iwl_mei_mutex);

	if (mei->amt_enabled == !!le32_to_cpu(dw->val))
		goto out;

	mei->amt_enabled = dw->val;

	if (mei->amt_enabled)
		iwl_mei_set_init_conf(mei);
	else if (iwl_mei_cache.ops)
		iwl_mei_cache.ops->rfkill(iwl_mei_cache.priv, false);

	schedule_work(&mei->netdev_work);

out:
	mutex_unlock(&iwl_mei_mutex);
}

static void iwl_mei_handle_nic_owner(struct mei_cl_device *cldev,
				     const struct iwl_sap_msg_dw *dw)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);

	mei->got_ownership = dw->val != cpu_to_le32(SAP_NIC_OWNER_ME);
}

static void iwl_mei_handle_can_release_ownership(struct mei_cl_device *cldev,
						 const void *payload)
{
	/* We can get ownership and driver is registered, go ahead */
	if (iwl_mei_cache.ops)
		iwl_mei_send_sap_msg(cldev,
				     SAP_MSG_NOTIF_HOST_ASKS_FOR_NIC_OWNERSHIP);
}

static void iwl_mei_handle_csme_taking_ownership(struct mei_cl_device *cldev,
						 const void *payload)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);

	dev_info(&cldev->dev, "CSME takes ownership\n");

	mei->got_ownership = false;

	if (iwl_mei_cache.ops && !mei->device_down) {
		/*
		 * Remember to send CSME_OWNERSHIP_CONFIRMED when the wifi
		 * driver is finished taking the device down.
		 */
		mei->csme_taking_ownership = true;

		iwl_mei_cache.ops->rfkill(iwl_mei_cache.priv, true);
	} else {
		iwl_mei_send_sap_msg(cldev,
				     SAP_MSG_NOTIF_CSME_OWNERSHIP_CONFIRMED);
	}
}

static void iwl_mei_handle_nvm(struct mei_cl_device *cldev,
			       const struct iwl_sap_nvm *sap_nvm)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
	const struct iwl_mei_nvm *mei_nvm = (const void *)sap_nvm;
	int i;

	kfree(mei->nvm);
	mei->nvm = kzalloc(sizeof(*mei_nvm), GFP_KERNEL);
	if (!mei->nvm)
		return;

	ether_addr_copy(mei->nvm->hw_addr, sap_nvm->hw_addr);
	mei->nvm->n_hw_addrs = sap_nvm->n_hw_addrs;
	mei->nvm->radio_cfg = le32_to_cpu(sap_nvm->radio_cfg);
	mei->nvm->caps = le32_to_cpu(sap_nvm->caps);
	mei->nvm->nvm_version = le32_to_cpu(sap_nvm->nvm_version);

	for (i = 0; i < ARRAY_SIZE(mei->nvm->channels); i++)
		mei->nvm->channels[i] = le32_to_cpu(sap_nvm->channels[i]);

	wake_up_all(&mei->get_nvm_wq);
}

static void iwl_mei_handle_rx_host_own_req(struct mei_cl_device *cldev,
					   const struct iwl_sap_msg_dw *dw)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);

	/*
	 * This means that we can't use the wifi device right now, CSME is not
	 * ready to let us use it.
	 */
	if (!dw->val) {
		dev_info(&cldev->dev, "Ownership req denied\n");
		return;
	}

	mei->got_ownership = true;
	wake_up_all(&mei->get_ownership_wq);

	iwl_mei_send_sap_msg(cldev,
			     SAP_MSG_NOTIF_HOST_OWNERSHIP_CONFIRMED);

	/* We can now start the connection, unblock rfkill */
	if (iwl_mei_cache.ops)
		iwl_mei_cache.ops->rfkill(iwl_mei_cache.priv, false);
}

static void iwl_mei_handle_pldr_ack(struct mei_cl_device *cldev,
				    const struct iwl_sap_pldr_ack_data *ack)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);

	mei->pldr_active = le32_to_cpu(ack->status) == SAP_PLDR_STATUS_SUCCESS;
	wake_up_all(&mei->pldr_wq);
}

static void iwl_mei_handle_ping(struct mei_cl_device *cldev,
				const struct iwl_sap_hdr *hdr)
{
	iwl_mei_send_sap_msg(cldev, SAP_MSG_NOTIF_PONG);
}

static void iwl_mei_handle_sap_msg(struct mei_cl_device *cldev,
				   const struct iwl_sap_hdr *hdr)
{
	u16 len = le16_to_cpu(hdr->len) + sizeof(*hdr);
	u16 type = le16_to_cpu(hdr->type);

	dev_dbg(&cldev->dev,
		"Got a new SAP message: type %d, len %d, seq %d\n",
		le16_to_cpu(hdr->type), len,
		le32_to_cpu(hdr->seq_num));

#define SAP_MSG_HANDLER(_cmd, _handler, _sz)				\
	case SAP_MSG_NOTIF_ ## _cmd:					\
		if (len < _sz) {					\
			dev_err(&cldev->dev,				\
				"Bad size for %d: %u < %u\n",		\
				le16_to_cpu(hdr->type),			\
				(unsigned int)len,			\
				(unsigned int)_sz);			\
			break;						\
		}							\
		mutex_lock(&iwl_mei_mutex);				\
		_handler(cldev, (const void *)hdr);			\
		mutex_unlock(&iwl_mei_mutex);				\
		break

#define SAP_MSG_HANDLER_NO_LOCK(_cmd, _handler, _sz)			\
	case SAP_MSG_NOTIF_ ## _cmd:					\
		if (len < _sz) {					\
			dev_err(&cldev->dev,				\
				"Bad size for %d: %u < %u\n",		\
				le16_to_cpu(hdr->type),			\
				(unsigned int)len,			\
				(unsigned int)_sz);			\
			break;						\
		}							\
		_handler(cldev, (const void *)hdr);			\
		break

#define SAP_MSG_HANDLER_NO_HANDLER(_cmd, _sz)				\
	case SAP_MSG_NOTIF_ ## _cmd:					\
		if (len < _sz) {					\
			dev_err(&cldev->dev,				\
				"Bad size for %d: %u < %u\n",		\
				le16_to_cpu(hdr->type),			\
				(unsigned int)len,			\
				(unsigned int)_sz);			\
			break;						\
		}							\
		break

	switch (type) {
	SAP_MSG_HANDLER(PING, iwl_mei_handle_ping, 0);
	SAP_MSG_HANDLER(CSME_FILTERS,
			iwl_mei_handle_csme_filters,
			sizeof(struct iwl_sap_csme_filters));
	SAP_MSG_HANDLER(CSME_CONN_STATUS,
			iwl_mei_handle_conn_status,
			sizeof(struct iwl_sap_notif_conn_status));
	SAP_MSG_HANDLER_NO_LOCK(AMT_STATE,
				iwl_mei_handle_amt_state,
				sizeof(struct iwl_sap_msg_dw));
	SAP_MSG_HANDLER_NO_HANDLER(PONG, 0);
	SAP_MSG_HANDLER(NVM, iwl_mei_handle_nvm,
			sizeof(struct iwl_sap_nvm));
	SAP_MSG_HANDLER(CSME_REPLY_TO_HOST_OWNERSHIP_REQ,
			iwl_mei_handle_rx_host_own_req,
			sizeof(struct iwl_sap_msg_dw));
	SAP_MSG_HANDLER(NIC_OWNER, iwl_mei_handle_nic_owner,
			sizeof(struct iwl_sap_msg_dw));
	SAP_MSG_HANDLER(CSME_CAN_RELEASE_OWNERSHIP,
			iwl_mei_handle_can_release_ownership, 0);
	SAP_MSG_HANDLER(CSME_TAKING_OWNERSHIP,
			iwl_mei_handle_csme_taking_ownership, 0);
	SAP_MSG_HANDLER(PLDR_ACK, iwl_mei_handle_pldr_ack,
			sizeof(struct iwl_sap_pldr_ack_data));
	default:
	/*
	 * This is not really an error, there are message that we decided
	 * to ignore, yet, it is useful to be able to leave a note if debug
	 * is enabled.
	 */
	dev_dbg(&cldev->dev, "Unsupported message: type %d, len %d\n",
		le16_to_cpu(hdr->type), len);
	}

#undef SAP_MSG_HANDLER
#undef SAP_MSG_HANDLER_NO_LOCK
}

static void iwl_mei_read_from_q(const u8 *q_head, u32 q_sz,
				u32 *_rd, u32 wr,
				void *_buf, u32 len)
{
	u8 *buf = _buf;
	u32 rd = *_rd;

	if (rd + len <= q_sz) {
		memcpy(buf, q_head + rd, len);
		rd += len;
	} else {
		memcpy(buf, q_head + rd, q_sz - rd);
		memcpy(buf + q_sz - rd, q_head, len - (q_sz - rd));
		rd = len - (q_sz - rd);
	}

	*_rd = rd;
}

#define QOS_HDR_IV_SNAP_LEN (sizeof(struct ieee80211_qos_hdr) +      \
			     IEEE80211_TKIP_IV_LEN +                 \
			     sizeof(rfc1042_header) + ETH_TLEN)

static void iwl_mei_handle_sap_data(struct mei_cl_device *cldev,
				    const u8 *q_head, u32 q_sz,
				    u32 rd, u32 wr, ssize_t valid_rx_sz,
				    struct sk_buff_head *tx_skbs)
{
	struct iwl_sap_hdr hdr;
	struct net_device *netdev =
		rcu_dereference_protected(iwl_mei_cache.netdev,
					  lockdep_is_held(&iwl_mei_mutex));

	if (!netdev)
		return;

	while (valid_rx_sz >= sizeof(hdr)) {
		struct ethhdr *ethhdr;
		unsigned char *data;
		struct sk_buff *skb;
		u16 len;

		iwl_mei_read_from_q(q_head, q_sz, &rd, wr, &hdr, sizeof(hdr));
		valid_rx_sz -= sizeof(hdr);
		len = le16_to_cpu(hdr.len);

		if (valid_rx_sz < len) {
			dev_err(&cldev->dev,
				"Data queue is corrupted: valid data len %zd, len %d\n",
				valid_rx_sz, len);
			break;
		}

		if (len < sizeof(*ethhdr)) {
			dev_err(&cldev->dev,
				"Data len is smaller than an ethernet header? len = %d\n",
				len);
		}

		valid_rx_sz -= len;

		if (le16_to_cpu(hdr.type) != SAP_MSG_DATA_PACKET) {
			dev_err(&cldev->dev, "Unsupported Rx data: type %d, len %d\n",
				le16_to_cpu(hdr.type), len);
			continue;
		}

		/* We need enough room for the WiFi header + SNAP + IV */
		skb = netdev_alloc_skb(netdev, len + QOS_HDR_IV_SNAP_LEN);
		if (!skb)
			continue;

		skb_reserve(skb, QOS_HDR_IV_SNAP_LEN);
		ethhdr = skb_push(skb, sizeof(*ethhdr));

		iwl_mei_read_from_q(q_head, q_sz, &rd, wr,
				    ethhdr, sizeof(*ethhdr));
		len -= sizeof(*ethhdr);

		skb_reset_mac_header(skb);
		skb_reset_network_header(skb);
		skb->protocol = ethhdr->h_proto;

		data = skb_put(skb, len);
		iwl_mei_read_from_q(q_head, q_sz, &rd, wr, data, len);

		/*
		 * Enqueue the skb here so that it can be sent later when we
		 * do not hold the mutex. TX'ing a packet with a mutex held is
		 * possible, but it wouldn't be nice to forbid the TX path to
		 * call any of iwlmei's functions, since every API from iwlmei
		 * needs the mutex.
		 */
		__skb_queue_tail(tx_skbs, skb);
	}
}

static void iwl_mei_handle_sap_rx_cmd(struct mei_cl_device *cldev,
				      const u8 *q_head, u32 q_sz,
				      u32 rd, u32 wr, ssize_t valid_rx_sz)
{
	struct page *p = alloc_page(GFP_KERNEL);
	struct iwl_sap_hdr *hdr;

	if (!p)
		return;

	hdr = page_address(p);

	while (valid_rx_sz >= sizeof(*hdr)) {
		u16 len;

		iwl_mei_read_from_q(q_head, q_sz, &rd, wr, hdr, sizeof(*hdr));
		valid_rx_sz -= sizeof(*hdr);
		len = le16_to_cpu(hdr->len);

		if (valid_rx_sz < len)
			break;

		iwl_mei_read_from_q(q_head, q_sz, &rd, wr, hdr + 1, len);

		trace_iwlmei_sap_cmd(hdr, false);
		iwl_mei_handle_sap_msg(cldev, hdr);
		valid_rx_sz -= len;
	}

	/* valid_rx_sz must be 0 now... */
	if (valid_rx_sz)
		dev_err(&cldev->dev,
			"More data in the buffer although we read it all\n");

	__free_page(p);
}

static void iwl_mei_handle_sap_rx(struct mei_cl_device *cldev,
				  struct iwl_sap_q_ctrl_blk *notif_q,
				  const u8 *q_head,
				  struct sk_buff_head *skbs,
				  u32 q_sz)
{
	u32 rd = le32_to_cpu(READ_ONCE(notif_q->rd_ptr));
	u32 wr = le32_to_cpu(READ_ONCE(notif_q->wr_ptr));
	ssize_t valid_rx_sz;

	if (rd > q_sz || wr > q_sz) {
		dev_err(&cldev->dev,
			"Pointers are past the buffer limit\n");
		return;
	}

	if (rd == wr)
		return;

	valid_rx_sz = wr > rd ? wr - rd : q_sz - rd + wr;

	if (skbs)
		iwl_mei_handle_sap_data(cldev, q_head, q_sz, rd, wr,
					valid_rx_sz, skbs);
	else
		iwl_mei_handle_sap_rx_cmd(cldev, q_head, q_sz, rd, wr,
					  valid_rx_sz);

	/* Increment the read pointer to point to the write pointer */
	WRITE_ONCE(notif_q->rd_ptr, cpu_to_le32(wr));
}

static void iwl_mei_handle_check_shared_area(struct mei_cl_device *cldev)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
	struct iwl_sap_q_ctrl_blk *notif_q;
	struct sk_buff_head tx_skbs;
	struct iwl_sap_dir *dir;
	void *q_head;
	u32 q_sz;

	if (!mei->shared_mem.ctrl)
		return;

	dir = &mei->shared_mem.ctrl->dir[SAP_DIRECTION_ME_TO_HOST];
	notif_q = &dir->q_ctrl_blk[SAP_QUEUE_IDX_NOTIF];
	q_head = mei->shared_mem.q_head[SAP_DIRECTION_ME_TO_HOST][SAP_QUEUE_IDX_NOTIF];
	q_sz = mei->shared_mem.q_size[SAP_DIRECTION_ME_TO_HOST][SAP_QUEUE_IDX_NOTIF];

	/*
	 * Do not hold the mutex here, but rather each and every message
	 * handler takes it.
	 * This allows message handlers to take it at a certain time.
	 */
	iwl_mei_handle_sap_rx(cldev, notif_q, q_head, NULL, q_sz);

	mutex_lock(&iwl_mei_mutex);
	dir = &mei->shared_mem.ctrl->dir[SAP_DIRECTION_ME_TO_HOST];
	notif_q = &dir->q_ctrl_blk[SAP_QUEUE_IDX_DATA];
	q_head = mei->shared_mem.q_head[SAP_DIRECTION_ME_TO_HOST][SAP_QUEUE_IDX_DATA];
	q_sz = mei->shared_mem.q_size[SAP_DIRECTION_ME_TO_HOST][SAP_QUEUE_IDX_DATA];

	__skb_queue_head_init(&tx_skbs);

	iwl_mei_handle_sap_rx(cldev, notif_q, q_head, &tx_skbs, q_sz);

	if (skb_queue_empty(&tx_skbs)) {
		mutex_unlock(&iwl_mei_mutex);
		return;
	}

	/*
	 * Take the RCU read lock before we unlock the mutex to make sure that
	 * even if the netdev is replaced by another non-NULL netdev right after
	 * we unlock the mutex, the old netdev will still be valid when we
	 * transmit the frames. We can't allow to replace the netdev here because
	 * the skbs hold a pointer to the netdev.
	 */
	rcu_read_lock();

	mutex_unlock(&iwl_mei_mutex);

	if (!rcu_access_pointer(iwl_mei_cache.netdev)) {
		dev_err(&cldev->dev, "Can't Tx without a netdev\n");
		skb_queue_purge(&tx_skbs);
		goto out;
	}

	while (!skb_queue_empty(&tx_skbs)) {
		struct sk_buff *skb = __skb_dequeue(&tx_skbs);

		trace_iwlmei_sap_data(skb, IWL_SAP_RX_DATA_TO_AIR);
		dev_queue_xmit(skb);
	}

out:
	rcu_read_unlock();
}

static void iwl_mei_rx(struct mei_cl_device *cldev)
{
	struct iwl_sap_me_msg_hdr *hdr;
	u8 msg[100];
	ssize_t ret;

	ret = mei_cldev_recv(cldev, (u8 *)&msg, sizeof(msg));
	if (ret < 0) {
		dev_err(&cldev->dev, "failed to receive data: %zd\n", ret);
		return;
	}

	if (ret == 0) {
		dev_err(&cldev->dev, "got an empty response\n");
		return;
	}

	hdr = (void *)msg;
	trace_iwlmei_me_msg(hdr, false);

	switch (le32_to_cpu(hdr->type)) {
	case SAP_ME_MSG_START_OK:
		BUILD_BUG_ON(sizeof(struct iwl_sap_me_msg_start_ok) >
			     sizeof(msg));

		iwl_mei_handle_rx_start_ok(cldev, (void *)msg, ret);
		break;
	case SAP_ME_MSG_CHECK_SHARED_AREA:
		iwl_mei_handle_check_shared_area(cldev);
		break;
	default:
		dev_err(&cldev->dev, "got a RX notification: %d\n",
			le32_to_cpu(hdr->type));
		break;
	}
}

static int iwl_mei_send_start(struct mei_cl_device *cldev)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
	struct iwl_sap_me_msg_start msg = {
		.hdr.type = cpu_to_le32(SAP_ME_MSG_START),
		.hdr.seq_num = cpu_to_le32(atomic_inc_return(&mei->seq_no)),
		.hdr.len = cpu_to_le32(sizeof(msg)),
		.supported_versions[0] = SAP_VERSION,
		.init_data_seq_num = cpu_to_le16(0x100),
		.init_notif_seq_num = cpu_to_le16(0x800),
	};
	int ret;

	trace_iwlmei_me_msg(&msg.hdr, true);
	ret = mei_cldev_send(cldev, (void *)&msg, sizeof(msg));
	if (ret != sizeof(msg)) {
		dev_err(&cldev->dev,
			"failed to send the SAP_ME_MSG_START message %d\n",
			ret);
		return ret;
	}

	return 0;
}

static int iwl_mei_enable(struct mei_cl_device *cldev)
{
	int ret;

	ret = mei_cldev_enable(cldev);
	if (ret < 0) {
		dev_err(&cldev->dev, "failed to enable the device: %d\n", ret);
		return ret;
	}

	ret = mei_cldev_register_rx_cb(cldev, iwl_mei_rx);
	if (ret) {
		dev_err(&cldev->dev,
			"failed to register to the rx cb: %d\n", ret);
		mei_cldev_disable(cldev);
		return ret;
	}

	return 0;
}

struct iwl_mei_nvm *iwl_mei_get_nvm(void)
{
	struct iwl_mei_nvm *nvm = NULL;
	struct iwl_mei *mei;
	int ret;

	mutex_lock(&iwl_mei_mutex);

	if (!iwl_mei_is_connected())
		goto out;

	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);

	if (!mei)
		goto out;

	ret = iwl_mei_send_sap_msg(iwl_mei_global_cldev,
				   SAP_MSG_NOTIF_GET_NVM);
	if (ret)
		goto out;

	mutex_unlock(&iwl_mei_mutex);

	ret = wait_event_timeout(mei->get_nvm_wq, mei->nvm, 2 * HZ);
	if (!ret)
		return NULL;

	mutex_lock(&iwl_mei_mutex);

	if (!iwl_mei_is_connected())
		goto out;

	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);

	if (!mei)
		goto out;

	if (mei->nvm)
		nvm = kmemdup(mei->nvm, sizeof(*mei->nvm), GFP_KERNEL);

out:
	mutex_unlock(&iwl_mei_mutex);
	return nvm;
}
EXPORT_SYMBOL_GPL(iwl_mei_get_nvm);

#define IWL_MEI_PLDR_NUM_RETRIES	3

int iwl_mei_pldr_req(void)
{
	struct iwl_mei *mei;
	int ret;
	struct iwl_sap_pldr_data msg = {
		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_PLDR),
		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
	};
	int i;

	mutex_lock(&iwl_mei_mutex);

	/* In case we didn't have a bind */
	if (!iwl_mei_is_connected()) {
		ret = 0;
		goto out;
	}

	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);

	if (!mei) {
		ret = -ENODEV;
		goto out;
	}

	if (!mei->amt_enabled) {
		ret = 0;
		goto out;
	}

	for (i = 0; i < IWL_MEI_PLDR_NUM_RETRIES; i++) {
		ret = iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);
		mutex_unlock(&iwl_mei_mutex);
		if (ret)
			return ret;

		ret = wait_event_timeout(mei->pldr_wq, mei->pldr_active, HZ / 2);
		if (ret)
			break;

		/* Take the mutex for the next iteration */
		mutex_lock(&iwl_mei_mutex);
	}

	if (ret)
		return 0;

	ret = -ETIMEDOUT;
out:
	mutex_unlock(&iwl_mei_mutex);
	return ret;
}
EXPORT_SYMBOL_GPL(iwl_mei_pldr_req);

int iwl_mei_get_ownership(void)
{
	struct iwl_mei *mei;
	int ret;

	mutex_lock(&iwl_mei_mutex);

	/* In case we didn't have a bind */
	if (!iwl_mei_is_connected()) {
		ret = 0;
		goto out;
	}

	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);

	if (!mei) {
		ret = -ENODEV;
		goto out;
	}

	if (!mei->amt_enabled) {
		ret = 0;
		goto out;
	}

	if (mei->got_ownership) {
		ret = 0;
		goto out;
	}

	ret = iwl_mei_send_sap_msg(mei->cldev,
				   SAP_MSG_NOTIF_HOST_ASKS_FOR_NIC_OWNERSHIP);
	if (ret)
		goto out;

	mutex_unlock(&iwl_mei_mutex);

	ret = wait_event_timeout(mei->get_ownership_wq,
				 mei->got_ownership, HZ / 2);
	return (!ret) ? -ETIMEDOUT : 0;
out:
	mutex_unlock(&iwl_mei_mutex);
	return ret;
}
EXPORT_SYMBOL_GPL(iwl_mei_get_ownership);

void iwl_mei_alive_notif(bool success)
{
	struct iwl_mei *mei;
	struct iwl_sap_pldr_end_data msg = {
		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_PLDR_END),
		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
		.status = success ? cpu_to_le32(SAP_PLDR_STATUS_SUCCESS) :
			cpu_to_le32(SAP_PLDR_STATUS_FAILURE),
	};

	mutex_lock(&iwl_mei_mutex);

	if (!iwl_mei_is_connected())
		goto out;

	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);
	if (!mei || !mei->pldr_active)
		goto out;

	mei->pldr_active = false;

	iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);
out:
	mutex_unlock(&iwl_mei_mutex);
}
EXPORT_SYMBOL_GPL(iwl_mei_alive_notif);

void iwl_mei_host_associated(const struct iwl_mei_conn_info *conn_info,
			     const struct iwl_mei_colloc_info *colloc_info)
{
	struct iwl_sap_notif_host_link_up msg = {
		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_HOST_LINK_UP),
		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
		.conn_info = {
			.ssid_len = cpu_to_le32(conn_info->ssid_len),
			.channel = conn_info->channel,
			.band = conn_info->band,
			.pairwise_cipher = cpu_to_le32(conn_info->pairwise_cipher),
			.auth_mode = cpu_to_le32(conn_info->auth_mode),
		},
	};
	struct iwl_mei *mei;

	if (conn_info->ssid_len > ARRAY_SIZE(msg.conn_info.ssid))
		return;

	memcpy(msg.conn_info.ssid, conn_info->ssid, conn_info->ssid_len);
	memcpy(msg.conn_info.bssid, conn_info->bssid, ETH_ALEN);

	if (colloc_info) {
		msg.colloc_channel = colloc_info->channel;
		msg.colloc_band = colloc_info->channel <= 14 ? 0 : 1;
		memcpy(msg.colloc_bssid, colloc_info->bssid, ETH_ALEN);
	}

	mutex_lock(&iwl_mei_mutex);

	if (!iwl_mei_is_connected())
		goto out;

	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);

	if (!mei && !mei->amt_enabled)
		goto out;

	iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);

out:
	kfree(iwl_mei_cache.conn_info);
	iwl_mei_cache.conn_info =
		kmemdup(&msg.conn_info, sizeof(msg.conn_info), GFP_KERNEL);
	mutex_unlock(&iwl_mei_mutex);
}
EXPORT_SYMBOL_GPL(iwl_mei_host_associated);

void iwl_mei_host_disassociated(void)
{
	struct iwl_mei *mei;
	struct iwl_sap_notif_host_link_down msg = {
		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_HOST_LINK_DOWN),
		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
		.type = HOST_LINK_DOWN_TYPE_TEMPORARY,
	};

	mutex_lock(&iwl_mei_mutex);

	if (!iwl_mei_is_connected())
		goto out;

	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);

	if (!mei && !mei->amt_enabled)
		goto out;

	iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);

out:
	kfree(iwl_mei_cache.conn_info);
	iwl_mei_cache.conn_info = NULL;
	mutex_unlock(&iwl_mei_mutex);
}
EXPORT_SYMBOL_GPL(iwl_mei_host_disassociated);

void iwl_mei_set_rfkill_state(bool hw_rfkill, bool sw_rfkill)
{
	struct iwl_mei *mei;
	u32 rfkill_state = 0;
	struct iwl_sap_msg_dw msg = {
		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_RADIO_STATE),
		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
	};

	if (!sw_rfkill)
		rfkill_state |= SAP_SW_RFKILL_DEASSERTED;

	if (!hw_rfkill)
		rfkill_state |= SAP_HW_RFKILL_DEASSERTED;

	mutex_lock(&iwl_mei_mutex);

	if (!iwl_mei_is_connected())
		goto out;

	msg.val = cpu_to_le32(rfkill_state);

	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);

	if (!mei && !mei->amt_enabled)
		goto out;

	iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);

out:
	iwl_mei_cache.rf_kill = rfkill_state;
	mutex_unlock(&iwl_mei_mutex);
}
EXPORT_SYMBOL_GPL(iwl_mei_set_rfkill_state);

void iwl_mei_set_nic_info(const u8 *mac_address, const u8 *nvm_address)
{
	struct iwl_mei *mei;
	struct iwl_sap_notif_host_nic_info msg = {
		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_NIC_INFO),
		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
	};

	mutex_lock(&iwl_mei_mutex);

	if (!iwl_mei_is_connected())
		goto out;

	ether_addr_copy(msg.mac_address, mac_address);
	ether_addr_copy(msg.nvm_address, nvm_address);

	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);

	if (!mei && !mei->amt_enabled)
		goto out;

	iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);

out:
	ether_addr_copy(iwl_mei_cache.mac_address, mac_address);
	ether_addr_copy(iwl_mei_cache.nvm_address, nvm_address);
	mutex_unlock(&iwl_mei_mutex);
}
EXPORT_SYMBOL_GPL(iwl_mei_set_nic_info);

void iwl_mei_set_country_code(u16 mcc)
{
	struct iwl_mei *mei;
	struct iwl_sap_notif_country_code msg = {
		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_COUNTRY_CODE),
		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
		.mcc = cpu_to_le16(mcc),
	};

	mutex_lock(&iwl_mei_mutex);

	if (!iwl_mei_is_connected())
		goto out;

	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);

	if (!mei && !mei->amt_enabled)
		goto out;

	iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);

out:
	iwl_mei_cache.mcc = mcc;
	mutex_unlock(&iwl_mei_mutex);
}
EXPORT_SYMBOL_GPL(iwl_mei_set_country_code);

void iwl_mei_set_power_limit(const __le16 *power_limit)
{
	struct iwl_mei *mei;
	struct iwl_sap_notif_sar_limits msg = {
		.hdr.type = cpu_to_le16(SAP_MSG_NOTIF_SAR_LIMITS),
		.hdr.len = cpu_to_le16(sizeof(msg) - sizeof(msg.hdr)),
	};

	mutex_lock(&iwl_mei_mutex);

	if (!iwl_mei_is_connected())
		goto out;

	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);

	if (!mei && !mei->amt_enabled)
		goto out;

	memcpy(msg.sar_chain_info_table, power_limit, sizeof(msg.sar_chain_info_table));

	iwl_mei_send_sap_msg_payload(mei->cldev, &msg.hdr);

out:
	kfree(iwl_mei_cache.power_limit);
	iwl_mei_cache.power_limit = kmemdup(power_limit,
					    sizeof(msg.sar_chain_info_table), GFP_KERNEL);
	mutex_unlock(&iwl_mei_mutex);
}
EXPORT_SYMBOL_GPL(iwl_mei_set_power_limit);

void iwl_mei_set_netdev(struct net_device *netdev)
{
	struct iwl_mei *mei;

	mutex_lock(&iwl_mei_mutex);

	if (!iwl_mei_is_connected()) {
		rcu_assign_pointer(iwl_mei_cache.netdev, netdev);
		goto out;
	}

	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);

	if (!mei)
		goto out;

	if (!netdev) {
		struct net_device *dev =
			rcu_dereference_protected(iwl_mei_cache.netdev,
						  lockdep_is_held(&iwl_mei_mutex));

		if (!dev)
			goto out;

		netdev_rx_handler_unregister(dev);
	}

	rcu_assign_pointer(iwl_mei_cache.netdev, netdev);

	if (netdev && mei->amt_enabled)
		netdev_rx_handler_register(netdev, iwl_mei_rx_handler, mei);

out:
	mutex_unlock(&iwl_mei_mutex);
}
EXPORT_SYMBOL_GPL(iwl_mei_set_netdev);

void iwl_mei_device_state(bool up)
{
	struct iwl_mei *mei;

	mutex_lock(&iwl_mei_mutex);

	if (!iwl_mei_is_connected())
		goto out;

	mei = mei_cldev_get_drvdata(iwl_mei_global_cldev);

	if (!mei)
		goto out;

	mei->device_down = !up;

	if (up || !mei->csme_taking_ownership)
		goto out;

	iwl_mei_send_sap_msg(mei->cldev,
			     SAP_MSG_NOTIF_CSME_OWNERSHIP_CONFIRMED);
	mei->csme_taking_ownership = false;
out:
	mutex_unlock(&iwl_mei_mutex);
}
EXPORT_SYMBOL_GPL(iwl_mei_device_state);

int iwl_mei_register(void *priv, const struct iwl_mei_ops *ops)
{
	int ret;

	/*
	 * We must have a non-NULL priv pointer to not crash when there are
	 * multiple WiFi devices.
	 */
	if (!priv)
		return -EINVAL;

	mutex_lock(&iwl_mei_mutex);

	/* do not allow registration if someone else already registered */
	if (iwl_mei_cache.priv || iwl_mei_cache.ops) {
		ret = -EBUSY;
		goto out;
	}

	iwl_mei_cache.priv = priv;
	iwl_mei_cache.ops = ops;

	if (iwl_mei_global_cldev) {
		struct iwl_mei *mei =
			mei_cldev_get_drvdata(iwl_mei_global_cldev);

		/* we have already a SAP connection */
		if (iwl_mei_is_connected()) {
			if (mei->amt_enabled)
				iwl_mei_send_sap_msg(mei->cldev,
						     SAP_MSG_NOTIF_WIFIDR_UP);
			ops->rfkill(priv, mei->link_prot_state);
		}
	}
	ret = 0;

out:
	mutex_unlock(&iwl_mei_mutex);
	return ret;
}
EXPORT_SYMBOL_GPL(iwl_mei_register);

void iwl_mei_start_unregister(void)
{
	mutex_lock(&iwl_mei_mutex);

	/* At this point, the wifi driver should have removed the netdev */
	if (rcu_access_pointer(iwl_mei_cache.netdev))
		pr_err("Still had a netdev pointer set upon unregister\n");

	kfree(iwl_mei_cache.conn_info);
	iwl_mei_cache.conn_info = NULL;
	kfree(iwl_mei_cache.power_limit);
	iwl_mei_cache.power_limit = NULL;
	iwl_mei_cache.ops = NULL;
	/* leave iwl_mei_cache.priv non-NULL to prevent any new registration */

	mutex_unlock(&iwl_mei_mutex);
}
EXPORT_SYMBOL_GPL(iwl_mei_start_unregister);

void iwl_mei_unregister_complete(void)
{
	mutex_lock(&iwl_mei_mutex);

	iwl_mei_cache.priv = NULL;

	if (iwl_mei_global_cldev) {
		struct iwl_mei *mei =
			mei_cldev_get_drvdata(iwl_mei_global_cldev);

		iwl_mei_send_sap_msg(mei->cldev, SAP_MSG_NOTIF_WIFIDR_DOWN);
		mei->got_ownership = false;
	}

	mutex_unlock(&iwl_mei_mutex);
}
EXPORT_SYMBOL_GPL(iwl_mei_unregister_complete);

#if IS_ENABLED(CONFIG_DEBUG_FS)

static ssize_t
iwl_mei_dbgfs_send_start_message_write(struct file *file,
				       const char __user *user_buf,
				       size_t count, loff_t *ppos)
{
	int ret;

	mutex_lock(&iwl_mei_mutex);

	if (!iwl_mei_global_cldev) {
		ret = -ENODEV;
		goto out;
	}

	ret = iwl_mei_send_start(iwl_mei_global_cldev);

out:
	mutex_unlock(&iwl_mei_mutex);
	return ret ?: count;
}

static const struct file_operations iwl_mei_dbgfs_send_start_message_ops = {
	.write = iwl_mei_dbgfs_send_start_message_write,
	.open = simple_open,
	.llseek = default_llseek,
};

static ssize_t iwl_mei_dbgfs_req_ownership_write(struct file *file,
						 const char __user *user_buf,
						 size_t count, loff_t *ppos)
{
	iwl_mei_get_ownership();

	return count;
}

static const struct file_operations iwl_mei_dbgfs_req_ownership_ops = {
	.write = iwl_mei_dbgfs_req_ownership_write,
	.open = simple_open,
	.llseek = default_llseek,
};

static void iwl_mei_dbgfs_register(struct iwl_mei *mei)
{
	mei->dbgfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);

	if (!mei->dbgfs_dir)
		return;

	debugfs_create_ulong("status", S_IRUSR,
			     mei->dbgfs_dir, &iwl_mei_status);
	debugfs_create_file("send_start_message", S_IWUSR, mei->dbgfs_dir,
			    mei, &iwl_mei_dbgfs_send_start_message_ops);
	debugfs_create_file("req_ownership", S_IWUSR, mei->dbgfs_dir,
			    mei, &iwl_mei_dbgfs_req_ownership_ops);
}

static void iwl_mei_dbgfs_unregister(struct iwl_mei *mei)
{
	debugfs_remove_recursive(mei->dbgfs_dir);
	mei->dbgfs_dir = NULL;
}

#else

static void iwl_mei_dbgfs_register(struct iwl_mei *mei) {}
static void iwl_mei_dbgfs_unregister(struct iwl_mei *mei) {}

#endif /* CONFIG_DEBUG_FS */

#define ALLOC_SHARED_MEM_RETRY_MAX_NUM	3

/*
 * iwl_mei_probe - the probe function called by the mei bus enumeration
 *
 * This allocates the data needed by iwlmei and sets a pointer to this data
 * into the mei_cl_device's drvdata.
 * It starts the SAP protocol by sending the SAP_ME_MSG_START without
 * waiting for the answer. The answer will be caught later by the Rx callback.
 */
static int iwl_mei_probe(struct mei_cl_device *cldev,
			 const struct mei_cl_device_id *id)
{
	int alloc_retry = ALLOC_SHARED_MEM_RETRY_MAX_NUM;
	struct iwl_mei *mei;
	int ret;

	mei = devm_kzalloc(&cldev->dev, sizeof(*mei), GFP_KERNEL);
	if (!mei)
		return -ENOMEM;

	init_waitqueue_head(&mei->get_nvm_wq);
	INIT_WORK(&mei->send_csa_msg_wk, iwl_mei_send_csa_msg_wk);
	INIT_DELAYED_WORK(&mei->csa_throttle_end_wk,
			  iwl_mei_csa_throttle_end_wk);
	init_waitqueue_head(&mei->get_ownership_wq);
	init_waitqueue_head(&mei->pldr_wq);
	spin_lock_init(&mei->data_q_lock);
	INIT_WORK(&mei->netdev_work, iwl_mei_netdev_work);

	mei_cldev_set_drvdata(cldev, mei);
	mei->cldev = cldev;
	mei->device_down = true;

	do {
		ret = iwl_mei_alloc_shared_mem(cldev);
		if (!ret)
			break;
		/*
		 * The CSME firmware needs to boot the internal WLAN client.
		 * This can take time in certain configurations (usually
		 * upon resume and when the whole CSME firmware is shut down
		 * during suspend).
		 *
		 * Wait a bit before retrying and hope we'll succeed next time.
		 */

		dev_dbg(&cldev->dev,
			"Couldn't allocate the shared memory: %d, attempt %d / %d\n",
			ret, alloc_retry, ALLOC_SHARED_MEM_RETRY_MAX_NUM);
		msleep(100);
		alloc_retry--;
	} while (alloc_retry);

	if (ret) {
		dev_err(&cldev->dev, "Couldn't allocate the shared memory: %d\n",
			ret);
		goto free;
	}

	iwl_mei_init_shared_mem(mei);

	ret = iwl_mei_enable(cldev);
	if (ret)
		goto free_shared_mem;

	iwl_mei_dbgfs_register(mei);

	/*
	 * We now have a Rx function in place, start the SAP protocol
	 * we expect to get the SAP_ME_MSG_START_OK response later on.
	 */
	mutex_lock(&iwl_mei_mutex);
	ret = iwl_mei_send_start(cldev);
	mutex_unlock(&iwl_mei_mutex);
	if (ret)
		goto debugfs_unregister;

	/* must be last */
	iwl_mei_global_cldev = cldev;

	return 0;

debugfs_unregister:
	iwl_mei_dbgfs_unregister(mei);
	mei_cldev_disable(cldev);
free_shared_mem:
	iwl_mei_free_shared_mem(cldev);
free:
	mei_cldev_set_drvdata(cldev, NULL);
	devm_kfree(&cldev->dev, mei);

	return ret;
}

#define SEND_SAP_MAX_WAIT_ITERATION 10
#define IWLMEI_DEVICE_DOWN_WAIT_ITERATION 50

static void iwl_mei_remove(struct mei_cl_device *cldev)
{
	struct iwl_mei *mei = mei_cldev_get_drvdata(cldev);
	int i;

	/*
	 * We are being removed while the bus is active, it means we are
	 * going to suspend/ shutdown, so the NIC will disappear.
	 */
	if (mei_cldev_enabled(cldev) && iwl_mei_cache.ops) {
		unsigned int iter = IWLMEI_DEVICE_DOWN_WAIT_ITERATION;
		bool down = false;

		/*
		 * In case of suspend, wait for the mac to stop and don't remove
		 * the interface. This will allow the interface to come back
		 * on resume.
		 */
		while (!down && iter--) {
			mdelay(1);

			mutex_lock(&iwl_mei_mutex);
			down = mei->device_down;
			mutex_unlock(&iwl_mei_mutex);
		}

		if (!down)
			iwl_mei_cache.ops->nic_stolen(iwl_mei_cache.priv);
	}

	if (rcu_access_pointer(iwl_mei_cache.netdev)) {
		struct net_device *dev;

		/*
		 * First take rtnl and only then the mutex to avoid an ABBA
		 * with iwl_mei_set_netdev()
		 */
		rtnl_lock();
		mutex_lock(&iwl_mei_mutex);

		/*
		 * If we are suspending and the wifi driver hasn't removed it's netdev
		 * yet, do it now. In any case, don't change the cache.netdev pointer.
		 */
		dev = rcu_dereference_protected(iwl_mei_cache.netdev,
						lockdep_is_held(&iwl_mei_mutex));

		netdev_rx_handler_unregister(dev);
		mutex_unlock(&iwl_mei_mutex);
		rtnl_unlock();
	}

	mutex_lock(&iwl_mei_mutex);

	if (mei->amt_enabled) {
		/*
		 * Tell CSME that we are going down so that it won't access the
		 * memory anymore, make sure this message goes through immediately.
		 */
		mei->csa_throttled = false;
		iwl_mei_send_sap_msg(mei->cldev,
				     SAP_MSG_NOTIF_HOST_GOES_DOWN);

		for (i = 0; i < SEND_SAP_MAX_WAIT_ITERATION; i++) {
			if (!iwl_mei_host_to_me_data_pending(mei))
				break;

			msleep(20);
		}

		/*
		 * If we couldn't make sure that CSME saw the HOST_GOES_DOWN
		 * message, it means that it will probably keep reading memory
		 * that we are going to unmap and free, expect IOMMU error
		 * messages.
		 */
		if (i == SEND_SAP_MAX_WAIT_ITERATION)
			dev_err(&mei->cldev->dev,
				"Couldn't get ACK from CSME on HOST_GOES_DOWN message\n");
	}

	mutex_unlock(&iwl_mei_mutex);

	/*
	 * This looks strange, but this lock is taken here to make sure that
	 * iwl_mei_add_data_to_ring called from the Tx path sees that we
	 * clear the IWL_MEI_STATUS_SAP_CONNECTED bit.
	 * Rx isn't a problem because the rx_handler can't be called after
	 * having been unregistered.
	 */
	spin_lock_bh(&mei->data_q_lock);
	clear_bit(IWL_MEI_STATUS_SAP_CONNECTED, &iwl_mei_status);
	spin_unlock_bh(&mei->data_q_lock);

	if (iwl_mei_cache.ops)
		iwl_mei_cache.ops->rfkill(iwl_mei_cache.priv, false);

	/*
	 * mei_cldev_disable will return only after all the MEI Rx is done.
	 * It must be called when iwl_mei_mutex is *not* held, since it waits
	 * for our Rx handler to complete.
	 * After it returns, no new Rx will start.
	 */
	mei_cldev_disable(cldev);

	/*
	 * Since the netdev was already removed and the netdev's removal
	 * includes a call to synchronize_net() so that we know there won't be
	 * any new Rx that will trigger the following workers.
	 */
	cancel_work_sync(&mei->send_csa_msg_wk);
	cancel_delayed_work_sync(&mei->csa_throttle_end_wk);
	cancel_work_sync(&mei->netdev_work);

	/*
	 * If someone waits for the ownership, let him know that we are going
	 * down and that we are not connected anymore. He'll be able to take
	 * the device.
	 */
	wake_up_all(&mei->get_ownership_wq);
	wake_up_all(&mei->pldr_wq);

	mutex_lock(&iwl_mei_mutex);

	iwl_mei_global_cldev = NULL;

	wake_up_all(&mei->get_nvm_wq);

	iwl_mei_free_shared_mem(cldev);

	iwl_mei_dbgfs_unregister(mei);

	mei_cldev_set_drvdata(cldev, NULL);

	kfree(mei->nvm);

	kfree(rcu_access_pointer(mei->filters));

	devm_kfree(&cldev->dev, mei);

	mutex_unlock(&iwl_mei_mutex);
}

static const struct mei_cl_device_id iwl_mei_tbl[] = {
	{
		.name = KBUILD_MODNAME,
		.uuid = MEI_WLAN_UUID,
		.version = MEI_CL_VERSION_ANY,
	},

	/* required last entry */
	{ }
};

/*
 * Do not export the device table because this module is loaded by
 * iwlwifi's dependency.
 */

static struct mei_cl_driver iwl_mei_cl_driver = {
	.id_table = iwl_mei_tbl,
	.name = KBUILD_MODNAME,
	.probe = iwl_mei_probe,
	.remove = iwl_mei_remove,
};

module_mei_cl_driver(iwl_mei_cl_driver);