summaryrefslogtreecommitdiffstats
path: root/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
blob: f98f2d2b8a1b69946c1f7d4ee9692c81986db4af (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
/******************************************************************************
 *
 * Copyright(c) 2003 - 2014 Intel Corporation. All rights reserved.
 * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
 * Copyright(c) 2016 - 2017 Intel Deutschland GmbH
 *
 * Portions of this file are derived from the ipw3945 project, as well
 * as portions of the ieee80211 subsystem header files.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
 *
 * The full GNU General Public License is included in this distribution in the
 * file called LICENSE.
 *
 * Contact Information:
 *  Intel Linux Wireless <linuxwifi@intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 *****************************************************************************/
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/gfp.h>

#include "iwl-prph.h"
#include "iwl-io.h"
#include "internal.h"
#include "iwl-op-mode.h"

/******************************************************************************
 *
 * RX path functions
 *
 ******************************************************************************/

/*
 * Rx theory of operation
 *
 * Driver allocates a circular buffer of Receive Buffer Descriptors (RBDs),
 * each of which point to Receive Buffers to be filled by the NIC.  These get
 * used not only for Rx frames, but for any command response or notification
 * from the NIC.  The driver and NIC manage the Rx buffers by means
 * of indexes into the circular buffer.
 *
 * Rx Queue Indexes
 * The host/firmware share two index registers for managing the Rx buffers.
 *
 * The READ index maps to the first position that the firmware may be writing
 * to -- the driver can read up to (but not including) this position and get
 * good data.
 * The READ index is managed by the firmware once the card is enabled.
 *
 * The WRITE index maps to the last position the driver has read from -- the
 * position preceding WRITE is the last slot the firmware can place a packet.
 *
 * The queue is empty (no good data) if WRITE = READ - 1, and is full if
 * WRITE = READ.
 *
 * During initialization, the host sets up the READ queue position to the first
 * INDEX position, and WRITE to the last (READ - 1 wrapped)
 *
 * When the firmware places a packet in a buffer, it will advance the READ index
 * and fire the RX interrupt.  The driver can then query the READ index and
 * process as many packets as possible, moving the WRITE index forward as it
 * resets the Rx queue buffers with new memory.
 *
 * The management in the driver is as follows:
 * + A list of pre-allocated RBDs is stored in iwl->rxq->rx_free.
 *   When the interrupt handler is called, the request is processed.
 *   The page is either stolen - transferred to the upper layer
 *   or reused - added immediately to the iwl->rxq->rx_free list.
 * + When the page is stolen - the driver updates the matching queue's used
 *   count, detaches the RBD and transfers it to the queue used list.
 *   When there are two used RBDs - they are transferred to the allocator empty
 *   list. Work is then scheduled for the allocator to start allocating
 *   eight buffers.
 *   When there are another 6 used RBDs - they are transferred to the allocator
 *   empty list and the driver tries to claim the pre-allocated buffers and
 *   add them to iwl->rxq->rx_free. If it fails - it continues to claim them
 *   until ready.
 *   When there are 8+ buffers in the free list - either from allocation or from
 *   8 reused unstolen pages - restock is called to update the FW and indexes.
 * + In order to make sure the allocator always has RBDs to use for allocation
 *   the allocator has initial pool in the size of num_queues*(8-2) - the
 *   maximum missing RBDs per allocation request (request posted with 2
 *    empty RBDs, there is no guarantee when the other 6 RBDs are supplied).
 *   The queues supplies the recycle of the rest of the RBDs.
 * + A received packet is processed and handed to the kernel network stack,
 *   detached from the iwl->rxq.  The driver 'processed' index is updated.
 * + If there are no allocated buffers in iwl->rxq->rx_free,
 *   the READ INDEX is not incremented and iwl->status(RX_STALLED) is set.
 *   If there were enough free buffers and RX_STALLED is set it is cleared.
 *
 *
 * Driver sequence:
 *
 * iwl_rxq_alloc()            Allocates rx_free
 * iwl_pcie_rx_replenish()    Replenishes rx_free list from rx_used, and calls
 *                            iwl_pcie_rxq_restock.
 *                            Used only during initialization.
 * iwl_pcie_rxq_restock()     Moves available buffers from rx_free into Rx
 *                            queue, updates firmware pointers, and updates
 *                            the WRITE index.
 * iwl_pcie_rx_allocator()     Background work for allocating pages.
 *
 * -- enable interrupts --
 * ISR - iwl_rx()             Detach iwl_rx_mem_buffers from pool up to the
 *                            READ INDEX, detaching the SKB from the pool.
 *                            Moves the packet buffer from queue to rx_used.
 *                            Posts and claims requests to the allocator.
 *                            Calls iwl_pcie_rxq_restock to refill any empty
 *                            slots.
 *
 * RBD life-cycle:
 *
 * Init:
 * rxq.pool -> rxq.rx_used -> rxq.rx_free -> rxq.queue
 *
 * Regular Receive interrupt:
 * Page Stolen:
 * rxq.queue -> rxq.rx_used -> allocator.rbd_empty ->
 * allocator.rbd_allocated -> rxq.rx_free -> rxq.queue
 * Page not Stolen:
 * rxq.queue -> rxq.rx_free -> rxq.queue
 * ...
 *
 */

/*
 * iwl_rxq_space - Return number of free slots available in queue.
 */
static int iwl_rxq_space(const struct iwl_rxq *rxq)
{
	/* Make sure rx queue size is a power of 2 */
	WARN_ON(rxq->queue_size & (rxq->queue_size - 1));

	/*
	 * There can be up to (RX_QUEUE_SIZE - 1) free slots, to avoid ambiguity
	 * between empty and completely full queues.
	 * The following is equivalent to modulo by RX_QUEUE_SIZE and is well
	 * defined for negative dividends.
	 */
	return (rxq->read - rxq->write - 1) & (rxq->queue_size - 1);
}

/*
 * iwl_dma_addr2rbd_ptr - convert a DMA address to a uCode read buffer ptr
 */
static inline __le32 iwl_pcie_dma_addr2rbd_ptr(dma_addr_t dma_addr)
{
	return cpu_to_le32((u32)(dma_addr >> 8));
}

/*
 * iwl_pcie_rx_stop - stops the Rx DMA
 */
int iwl_pcie_rx_stop(struct iwl_trans *trans)
{
	if (trans->cfg->mq_rx_supported) {
		iwl_write_prph(trans, RFH_RXF_DMA_CFG, 0);
		return iwl_poll_prph_bit(trans, RFH_GEN_STATUS,
					   RXF_DMA_IDLE, RXF_DMA_IDLE, 1000);
	} else {
		iwl_write_direct32(trans, FH_MEM_RCSR_CHNL0_CONFIG_REG, 0);
		return iwl_poll_direct_bit(trans, FH_MEM_RSSR_RX_STATUS_REG,
					   FH_RSSR_CHNL0_RX_STATUS_CHNL_IDLE,
					   1000);
	}
}

/*
 * iwl_pcie_rxq_inc_wr_ptr - Update the write pointer for the RX queue
 */
static void iwl_pcie_rxq_inc_wr_ptr(struct iwl_trans *trans,
				    struct iwl_rxq *rxq)
{
	u32 reg;

	lockdep_assert_held(&rxq->lock);

	/*
	 * explicitly wake up the NIC if:
	 * 1. shadow registers aren't enabled
	 * 2. there is a chance that the NIC is asleep
	 */
	if (!trans->cfg->base_params->shadow_reg_enable &&
	    test_bit(STATUS_TPOWER_PMI, &trans->status)) {
		reg = iwl_read32(trans, CSR_UCODE_DRV_GP1);

		if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) {
			IWL_DEBUG_INFO(trans, "Rx queue requesting wakeup, GP1 = 0x%x\n",
				       reg);
			iwl_set_bit(trans, CSR_GP_CNTRL,
				    CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
			rxq->need_update = true;
			return;
		}
	}

	rxq->write_actual = round_down(rxq->write, 8);
	if (trans->cfg->mq_rx_supported)
		iwl_write32(trans, RFH_Q_FRBDCB_WIDX_TRG(rxq->id),
			    rxq->write_actual);
	else
		iwl_write32(trans, FH_RSCSR_CHNL0_WPTR, rxq->write_actual);
}

static void iwl_pcie_rxq_check_wrptr(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	int i;

	for (i = 0; i < trans->num_rx_queues; i++) {
		struct iwl_rxq *rxq = &trans_pcie->rxq[i];

		if (!rxq->need_update)
			continue;
		spin_lock(&rxq->lock);
		iwl_pcie_rxq_inc_wr_ptr(trans, rxq);
		rxq->need_update = false;
		spin_unlock(&rxq->lock);
	}
}

/*
 * iwl_pcie_rxmq_restock - restock implementation for multi-queue rx
 */
static void iwl_pcie_rxmq_restock(struct iwl_trans *trans,
				  struct iwl_rxq *rxq)
{
	struct iwl_rx_mem_buffer *rxb;

	/*
	 * If the device isn't enabled - no need to try to add buffers...
	 * This can happen when we stop the device and still have an interrupt
	 * pending. We stop the APM before we sync the interrupts because we
	 * have to (see comment there). On the other hand, since the APM is
	 * stopped, we cannot access the HW (in particular not prph).
	 * So don't try to restock if the APM has been already stopped.
	 */
	if (!test_bit(STATUS_DEVICE_ENABLED, &trans->status))
		return;

	spin_lock(&rxq->lock);
	while (rxq->free_count) {
		__le64 *bd = (__le64 *)rxq->bd;

		/* Get next free Rx buffer, remove from free list */
		rxb = list_first_entry(&rxq->rx_free, struct iwl_rx_mem_buffer,
				       list);
		list_del(&rxb->list);
		rxb->invalid = false;
		/* 12 first bits are expected to be empty */
		WARN_ON(rxb->page_dma & DMA_BIT_MASK(12));
		/* Point to Rx buffer via next RBD in circular buffer */
		bd[rxq->write] = cpu_to_le64(rxb->page_dma | rxb->vid);
		rxq->write = (rxq->write + 1) & MQ_RX_TABLE_MASK;
		rxq->free_count--;
	}
	spin_unlock(&rxq->lock);

	/*
	 * If we've added more space for the firmware to place data, tell it.
	 * Increment device's write pointer in multiples of 8.
	 */
	if (rxq->write_actual != (rxq->write & ~0x7)) {
		spin_lock(&rxq->lock);
		iwl_pcie_rxq_inc_wr_ptr(trans, rxq);
		spin_unlock(&rxq->lock);
	}
}

/*
 * iwl_pcie_rxsq_restock - restock implementation for single queue rx
 */
static void iwl_pcie_rxsq_restock(struct iwl_trans *trans,
				  struct iwl_rxq *rxq)
{
	struct iwl_rx_mem_buffer *rxb;

	/*
	 * If the device isn't enabled - not need to try to add buffers...
	 * This can happen when we stop the device and still have an interrupt
	 * pending. We stop the APM before we sync the interrupts because we
	 * have to (see comment there). On the other hand, since the APM is
	 * stopped, we cannot access the HW (in particular not prph).
	 * So don't try to restock if the APM has been already stopped.
	 */
	if (!test_bit(STATUS_DEVICE_ENABLED, &trans->status))
		return;

	spin_lock(&rxq->lock);
	while ((iwl_rxq_space(rxq) > 0) && (rxq->free_count)) {
		__le32 *bd = (__le32 *)rxq->bd;
		/* The overwritten rxb must be a used one */
		rxb = rxq->queue[rxq->write];
		BUG_ON(rxb && rxb->page);

		/* Get next free Rx buffer, remove from free list */
		rxb = list_first_entry(&rxq->rx_free, struct iwl_rx_mem_buffer,
				       list);
		list_del(&rxb->list);
		rxb->invalid = false;

		/* Point to Rx buffer via next RBD in circular buffer */
		bd[rxq->write] = iwl_pcie_dma_addr2rbd_ptr(rxb->page_dma);
		rxq->queue[rxq->write] = rxb;
		rxq->write = (rxq->write + 1) & RX_QUEUE_MASK;
		rxq->free_count--;
	}
	spin_unlock(&rxq->lock);

	/* If we've added more space for the firmware to place data, tell it.
	 * Increment device's write pointer in multiples of 8. */
	if (rxq->write_actual != (rxq->write & ~0x7)) {
		spin_lock(&rxq->lock);
		iwl_pcie_rxq_inc_wr_ptr(trans, rxq);
		spin_unlock(&rxq->lock);
	}
}

/*
 * iwl_pcie_rxq_restock - refill RX queue from pre-allocated pool
 *
 * If there are slots in the RX queue that need to be restocked,
 * and we have free pre-allocated buffers, fill the ranks as much
 * as we can, pulling from rx_free.
 *
 * This moves the 'write' index forward to catch up with 'processed', and
 * also updates the memory address in the firmware to reference the new
 * target buffer.
 */
static
void iwl_pcie_rxq_restock(struct iwl_trans *trans, struct iwl_rxq *rxq)
{
	if (trans->cfg->mq_rx_supported)
		iwl_pcie_rxmq_restock(trans, rxq);
	else
		iwl_pcie_rxsq_restock(trans, rxq);
}

/*
 * iwl_pcie_rx_alloc_page - allocates and returns a page.
 *
 */
static struct page *iwl_pcie_rx_alloc_page(struct iwl_trans *trans,
					   gfp_t priority)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct page *page;
	gfp_t gfp_mask = priority;

	if (trans_pcie->rx_page_order > 0)
		gfp_mask |= __GFP_COMP;

	/* Alloc a new receive buffer */
	page = alloc_pages(gfp_mask, trans_pcie->rx_page_order);
	if (!page) {
		if (net_ratelimit())
			IWL_DEBUG_INFO(trans, "alloc_pages failed, order: %d\n",
				       trans_pcie->rx_page_order);
		/*
		 * Issue an error if we don't have enough pre-allocated
		  * buffers.
`		 */
		if (!(gfp_mask & __GFP_NOWARN) && net_ratelimit())
			IWL_CRIT(trans,
				 "Failed to alloc_pages\n");
		return NULL;
	}
	return page;
}

/*
 * iwl_pcie_rxq_alloc_rbs - allocate a page for each used RBD
 *
 * A used RBD is an Rx buffer that has been given to the stack. To use it again
 * a page must be allocated and the RBD must point to the page. This function
 * doesn't change the HW pointer but handles the list of pages that is used by
 * iwl_pcie_rxq_restock. The latter function will update the HW to use the newly
 * allocated buffers.
 */
static void iwl_pcie_rxq_alloc_rbs(struct iwl_trans *trans, gfp_t priority,
				   struct iwl_rxq *rxq)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rx_mem_buffer *rxb;
	struct page *page;

	while (1) {
		spin_lock(&rxq->lock);
		if (list_empty(&rxq->rx_used)) {
			spin_unlock(&rxq->lock);
			return;
		}
		spin_unlock(&rxq->lock);

		/* Alloc a new receive buffer */
		page = iwl_pcie_rx_alloc_page(trans, priority);
		if (!page)
			return;

		spin_lock(&rxq->lock);

		if (list_empty(&rxq->rx_used)) {
			spin_unlock(&rxq->lock);
			__free_pages(page, trans_pcie->rx_page_order);
			return;
		}
		rxb = list_first_entry(&rxq->rx_used, struct iwl_rx_mem_buffer,
				       list);
		list_del(&rxb->list);
		spin_unlock(&rxq->lock);

		BUG_ON(rxb->page);
		rxb->page = page;
		/* Get physical address of the RB */
		rxb->page_dma =
			dma_map_page(trans->dev, page, 0,
				     PAGE_SIZE << trans_pcie->rx_page_order,
				     DMA_FROM_DEVICE);
		if (dma_mapping_error(trans->dev, rxb->page_dma)) {
			rxb->page = NULL;
			spin_lock(&rxq->lock);
			list_add(&rxb->list, &rxq->rx_used);
			spin_unlock(&rxq->lock);
			__free_pages(page, trans_pcie->rx_page_order);
			return;
		}

		spin_lock(&rxq->lock);

		list_add_tail(&rxb->list, &rxq->rx_free);
		rxq->free_count++;

		spin_unlock(&rxq->lock);
	}
}

static void iwl_pcie_free_rbs_pool(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	int i;

	for (i = 0; i < RX_POOL_SIZE; i++) {
		if (!trans_pcie->rx_pool[i].page)
			continue;
		dma_unmap_page(trans->dev, trans_pcie->rx_pool[i].page_dma,
			       PAGE_SIZE << trans_pcie->rx_page_order,
			       DMA_FROM_DEVICE);
		__free_pages(trans_pcie->rx_pool[i].page,
			     trans_pcie->rx_page_order);
		trans_pcie->rx_pool[i].page = NULL;
	}
}

/*
 * iwl_pcie_rx_allocator - Allocates pages in the background for RX queues
 *
 * Allocates for each received request 8 pages
 * Called as a scheduled work item.
 */
static void iwl_pcie_rx_allocator(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rb_allocator *rba = &trans_pcie->rba;
	struct list_head local_empty;
	int pending = atomic_xchg(&rba->req_pending, 0);

	IWL_DEBUG_RX(trans, "Pending allocation requests = %d\n", pending);

	/* If we were scheduled - there is at least one request */
	spin_lock(&rba->lock);
	/* swap out the rba->rbd_empty to a local list */
	list_replace_init(&rba->rbd_empty, &local_empty);
	spin_unlock(&rba->lock);

	while (pending) {
		int i;
		LIST_HEAD(local_allocated);
		gfp_t gfp_mask = GFP_KERNEL;

		/* Do not post a warning if there are only a few requests */
		if (pending < RX_PENDING_WATERMARK)
			gfp_mask |= __GFP_NOWARN;

		for (i = 0; i < RX_CLAIM_REQ_ALLOC;) {
			struct iwl_rx_mem_buffer *rxb;
			struct page *page;

			/* List should never be empty - each reused RBD is
			 * returned to the list, and initial pool covers any
			 * possible gap between the time the page is allocated
			 * to the time the RBD is added.
			 */
			BUG_ON(list_empty(&local_empty));
			/* Get the first rxb from the rbd list */
			rxb = list_first_entry(&local_empty,
					       struct iwl_rx_mem_buffer, list);
			BUG_ON(rxb->page);

			/* Alloc a new receive buffer */
			page = iwl_pcie_rx_alloc_page(trans, gfp_mask);
			if (!page)
				continue;
			rxb->page = page;

			/* Get physical address of the RB */
			rxb->page_dma = dma_map_page(trans->dev, page, 0,
					PAGE_SIZE << trans_pcie->rx_page_order,
					DMA_FROM_DEVICE);
			if (dma_mapping_error(trans->dev, rxb->page_dma)) {
				rxb->page = NULL;
				__free_pages(page, trans_pcie->rx_page_order);
				continue;
			}

			/* move the allocated entry to the out list */
			list_move(&rxb->list, &local_allocated);
			i++;
		}

		pending--;
		if (!pending) {
			pending = atomic_xchg(&rba->req_pending, 0);
			IWL_DEBUG_RX(trans,
				     "Pending allocation requests = %d\n",
				     pending);
		}

		spin_lock(&rba->lock);
		/* add the allocated rbds to the allocator allocated list */
		list_splice_tail(&local_allocated, &rba->rbd_allocated);
		/* get more empty RBDs for current pending requests */
		list_splice_tail_init(&rba->rbd_empty, &local_empty);
		spin_unlock(&rba->lock);

		atomic_inc(&rba->req_ready);
	}

	spin_lock(&rba->lock);
	/* return unused rbds to the allocator empty list */
	list_splice_tail(&local_empty, &rba->rbd_empty);
	spin_unlock(&rba->lock);
}

/*
 * iwl_pcie_rx_allocator_get - returns the pre-allocated pages
.*
.* Called by queue when the queue posted allocation request and
 * has freed 8 RBDs in order to restock itself.
 * This function directly moves the allocated RBs to the queue's ownership
 * and updates the relevant counters.
 */
static void iwl_pcie_rx_allocator_get(struct iwl_trans *trans,
				      struct iwl_rxq *rxq)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rb_allocator *rba = &trans_pcie->rba;
	int i;

	lockdep_assert_held(&rxq->lock);

	/*
	 * atomic_dec_if_positive returns req_ready - 1 for any scenario.
	 * If req_ready is 0 atomic_dec_if_positive will return -1 and this
	 * function will return early, as there are no ready requests.
	 * atomic_dec_if_positive will perofrm the *actual* decrement only if
	 * req_ready > 0, i.e. - there are ready requests and the function
	 * hands one request to the caller.
	 */
	if (atomic_dec_if_positive(&rba->req_ready) < 0)
		return;

	spin_lock(&rba->lock);
	for (i = 0; i < RX_CLAIM_REQ_ALLOC; i++) {
		/* Get next free Rx buffer, remove it from free list */
		struct iwl_rx_mem_buffer *rxb =
			list_first_entry(&rba->rbd_allocated,
					 struct iwl_rx_mem_buffer, list);

		list_move(&rxb->list, &rxq->rx_free);
	}
	spin_unlock(&rba->lock);

	rxq->used_count -= RX_CLAIM_REQ_ALLOC;
	rxq->free_count += RX_CLAIM_REQ_ALLOC;
}

static void iwl_pcie_rx_allocator_work(struct work_struct *data)
{
	struct iwl_rb_allocator *rba_p =
		container_of(data, struct iwl_rb_allocator, rx_alloc);
	struct iwl_trans_pcie *trans_pcie =
		container_of(rba_p, struct iwl_trans_pcie, rba);

	iwl_pcie_rx_allocator(trans_pcie->trans);
}

static int iwl_pcie_rx_alloc(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rb_allocator *rba = &trans_pcie->rba;
	struct device *dev = trans->dev;
	int i;
	int free_size = trans->cfg->mq_rx_supported ? sizeof(__le64) :
						      sizeof(__le32);

	if (WARN_ON(trans_pcie->rxq))
		return -EINVAL;

	trans_pcie->rxq = kcalloc(trans->num_rx_queues, sizeof(struct iwl_rxq),
				  GFP_KERNEL);
	if (!trans_pcie->rxq)
		return -EINVAL;

	spin_lock_init(&rba->lock);

	for (i = 0; i < trans->num_rx_queues; i++) {
		struct iwl_rxq *rxq = &trans_pcie->rxq[i];

		spin_lock_init(&rxq->lock);
		if (trans->cfg->mq_rx_supported)
			rxq->queue_size = MQ_RX_TABLE_SIZE;
		else
			rxq->queue_size = RX_QUEUE_SIZE;

		/*
		 * Allocate the circular buffer of Read Buffer Descriptors
		 * (RBDs)
		 */
		rxq->bd = dma_zalloc_coherent(dev,
					     free_size * rxq->queue_size,
					     &rxq->bd_dma, GFP_KERNEL);
		if (!rxq->bd)
			goto err;

		if (trans->cfg->mq_rx_supported) {
			rxq->used_bd = dma_zalloc_coherent(dev,
							   sizeof(__le32) *
							   rxq->queue_size,
							   &rxq->used_bd_dma,
							   GFP_KERNEL);
			if (!rxq->used_bd)
				goto err;
		}

		/*Allocate the driver's pointer to receive buffer status */
		rxq->rb_stts = dma_zalloc_coherent(dev, sizeof(*rxq->rb_stts),
						   &rxq->rb_stts_dma,
						   GFP_KERNEL);
		if (!rxq->rb_stts)
			goto err;
	}
	return 0;

err:
	for (i = 0; i < trans->num_rx_queues; i++) {
		struct iwl_rxq *rxq = &trans_pcie->rxq[i];

		if (rxq->bd)
			dma_free_coherent(dev, free_size * rxq->queue_size,
					  rxq->bd, rxq->bd_dma);
		rxq->bd_dma = 0;
		rxq->bd = NULL;

		if (rxq->rb_stts)
			dma_free_coherent(trans->dev,
					  sizeof(struct iwl_rb_status),
					  rxq->rb_stts, rxq->rb_stts_dma);

		if (rxq->used_bd)
			dma_free_coherent(dev, sizeof(__le32) * rxq->queue_size,
					  rxq->used_bd, rxq->used_bd_dma);
		rxq->used_bd_dma = 0;
		rxq->used_bd = NULL;
	}
	kfree(trans_pcie->rxq);

	return -ENOMEM;
}

static void iwl_pcie_rx_hw_init(struct iwl_trans *trans, struct iwl_rxq *rxq)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	u32 rb_size;
	unsigned long flags;
	const u32 rfdnlog = RX_QUEUE_SIZE_LOG; /* 256 RBDs */

	switch (trans_pcie->rx_buf_size) {
	case IWL_AMSDU_4K:
		rb_size = FH_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_4K;
		break;
	case IWL_AMSDU_8K:
		rb_size = FH_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_8K;
		break;
	case IWL_AMSDU_12K:
		rb_size = FH_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_12K;
		break;
	default:
		WARN_ON(1);
		rb_size = FH_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_4K;
	}

	if (!iwl_trans_grab_nic_access(trans, &flags))
		return;

	/* Stop Rx DMA */
	iwl_write32(trans, FH_MEM_RCSR_CHNL0_CONFIG_REG, 0);
	/* reset and flush pointers */
	iwl_write32(trans, FH_MEM_RCSR_CHNL0_RBDCB_WPTR, 0);
	iwl_write32(trans, FH_MEM_RCSR_CHNL0_FLUSH_RB_REQ, 0);
	iwl_write32(trans, FH_RSCSR_CHNL0_RDPTR, 0);

	/* Reset driver's Rx queue write index */
	iwl_write32(trans, FH_RSCSR_CHNL0_RBDCB_WPTR_REG, 0);

	/* Tell device where to find RBD circular buffer in DRAM */
	iwl_write32(trans, FH_RSCSR_CHNL0_RBDCB_BASE_REG,
		    (u32)(rxq->bd_dma >> 8));

	/* Tell device where in DRAM to update its Rx status */
	iwl_write32(trans, FH_RSCSR_CHNL0_STTS_WPTR_REG,
		    rxq->rb_stts_dma >> 4);

	/* Enable Rx DMA
	 * FH_RCSR_CHNL0_RX_IGNORE_RXF_EMPTY is set because of HW bug in
	 *      the credit mechanism in 5000 HW RX FIFO
	 * Direct rx interrupts to hosts
	 * Rx buffer size 4 or 8k or 12k
	 * RB timeout 0x10
	 * 256 RBDs
	 */
	iwl_write32(trans, FH_MEM_RCSR_CHNL0_CONFIG_REG,
		    FH_RCSR_RX_CONFIG_CHNL_EN_ENABLE_VAL |
		    FH_RCSR_CHNL0_RX_IGNORE_RXF_EMPTY |
		    FH_RCSR_CHNL0_RX_CONFIG_IRQ_DEST_INT_HOST_VAL |
		    rb_size |
		    (RX_RB_TIMEOUT << FH_RCSR_RX_CONFIG_REG_IRQ_RBTH_POS) |
		    (rfdnlog << FH_RCSR_RX_CONFIG_RBDCB_SIZE_POS));

	iwl_trans_release_nic_access(trans, &flags);

	/* Set interrupt coalescing timer to default (2048 usecs) */
	iwl_write8(trans, CSR_INT_COALESCING, IWL_HOST_INT_TIMEOUT_DEF);

	/* W/A for interrupt coalescing bug in 7260 and 3160 */
	if (trans->cfg->host_interrupt_operation_mode)
		iwl_set_bit(trans, CSR_INT_COALESCING, IWL_HOST_INT_OPER_MODE);
}

void iwl_pcie_enable_rx_wake(struct iwl_trans *trans, bool enable)
{
	/*
	 * Turn on the chicken-bits that cause MAC wakeup for RX-related
	 * values.
	 * This costs some power, but needed for W/A 9000 integrated A-step
	 * bug where shadow registers are not in the retention list and their
	 * value is lost when NIC powers down
	 */
	if (trans->cfg->integrated) {
		iwl_set_bit(trans, CSR_MAC_SHADOW_REG_CTRL,
			    CSR_MAC_SHADOW_REG_CTRL_RX_WAKE);
		iwl_set_bit(trans, CSR_MAC_SHADOW_REG_CTL2,
			    CSR_MAC_SHADOW_REG_CTL2_RX_WAKE);
	}
}

static void iwl_pcie_rx_mq_hw_init(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	u32 rb_size, enabled = 0;
	unsigned long flags;
	int i;

	switch (trans_pcie->rx_buf_size) {
	case IWL_AMSDU_4K:
		rb_size = RFH_RXF_DMA_RB_SIZE_4K;
		break;
	case IWL_AMSDU_8K:
		rb_size = RFH_RXF_DMA_RB_SIZE_8K;
		break;
	case IWL_AMSDU_12K:
		rb_size = RFH_RXF_DMA_RB_SIZE_12K;
		break;
	default:
		WARN_ON(1);
		rb_size = RFH_RXF_DMA_RB_SIZE_4K;
	}

	if (!iwl_trans_grab_nic_access(trans, &flags))
		return;

	/* Stop Rx DMA */
	iwl_write_prph_no_grab(trans, RFH_RXF_DMA_CFG, 0);
	/* disable free amd used rx queue operation */
	iwl_write_prph_no_grab(trans, RFH_RXF_RXQ_ACTIVE, 0);

	for (i = 0; i < trans->num_rx_queues; i++) {
		/* Tell device where to find RBD free table in DRAM */
		iwl_write_prph64_no_grab(trans,
					 RFH_Q_FRBDCB_BA_LSB(i),
					 trans_pcie->rxq[i].bd_dma);
		/* Tell device where to find RBD used table in DRAM */
		iwl_write_prph64_no_grab(trans,
					 RFH_Q_URBDCB_BA_LSB(i),
					 trans_pcie->rxq[i].used_bd_dma);
		/* Tell device where in DRAM to update its Rx status */
		iwl_write_prph64_no_grab(trans,
					 RFH_Q_URBD_STTS_WPTR_LSB(i),
					 trans_pcie->rxq[i].rb_stts_dma);
		/* Reset device indice tables */
		iwl_write_prph_no_grab(trans, RFH_Q_FRBDCB_WIDX(i), 0);
		iwl_write_prph_no_grab(trans, RFH_Q_FRBDCB_RIDX(i), 0);
		iwl_write_prph_no_grab(trans, RFH_Q_URBDCB_WIDX(i), 0);

		enabled |= BIT(i) | BIT(i + 16);
	}

	/*
	 * Enable Rx DMA
	 * Rx buffer size 4 or 8k or 12k
	 * Min RB size 4 or 8
	 * Drop frames that exceed RB size
	 * 512 RBDs
	 */
	iwl_write_prph_no_grab(trans, RFH_RXF_DMA_CFG,
			       RFH_DMA_EN_ENABLE_VAL | rb_size |
			       RFH_RXF_DMA_MIN_RB_4_8 |
			       RFH_RXF_DMA_DROP_TOO_LARGE_MASK |
			       RFH_RXF_DMA_RBDCB_SIZE_512);

	/*
	 * Activate DMA snooping.
	 * Set RX DMA chunk size to 64B for IOSF and 128B for PCIe
	 * Default queue is 0
	 */
	iwl_write_prph_no_grab(trans, RFH_GEN_CFG, RFH_GEN_CFG_RFH_DMA_SNOOP |
			       (DEFAULT_RXQ_NUM <<
				RFH_GEN_CFG_DEFAULT_RXQ_NUM_POS) |
			       RFH_GEN_CFG_SERVICE_DMA_SNOOP |
			       (trans->cfg->integrated ?
				RFH_GEN_CFG_RB_CHUNK_SIZE_64 :
				RFH_GEN_CFG_RB_CHUNK_SIZE_128) <<
			       RFH_GEN_CFG_RB_CHUNK_SIZE_POS);
	/* Enable the relevant rx queues */
	iwl_write_prph_no_grab(trans, RFH_RXF_RXQ_ACTIVE, enabled);

	iwl_trans_release_nic_access(trans, &flags);

	/* Set interrupt coalescing timer to default (2048 usecs) */
	iwl_write8(trans, CSR_INT_COALESCING, IWL_HOST_INT_TIMEOUT_DEF);

	iwl_pcie_enable_rx_wake(trans, true);
}

static void iwl_pcie_rx_init_rxb_lists(struct iwl_rxq *rxq)
{
	lockdep_assert_held(&rxq->lock);

	INIT_LIST_HEAD(&rxq->rx_free);
	INIT_LIST_HEAD(&rxq->rx_used);
	rxq->free_count = 0;
	rxq->used_count = 0;
}

static int iwl_pcie_dummy_napi_poll(struct napi_struct *napi, int budget)
{
	WARN_ON(1);
	return 0;
}

static int _iwl_pcie_rx_init(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rxq *def_rxq;
	struct iwl_rb_allocator *rba = &trans_pcie->rba;
	int i, err, queue_size, allocator_pool_size, num_alloc;

	if (!trans_pcie->rxq) {
		err = iwl_pcie_rx_alloc(trans);
		if (err)
			return err;
	}
	def_rxq = trans_pcie->rxq;
	if (!rba->alloc_wq)
		rba->alloc_wq = alloc_workqueue("rb_allocator",
						WQ_HIGHPRI | WQ_UNBOUND, 1);
	INIT_WORK(&rba->rx_alloc, iwl_pcie_rx_allocator_work);

	spin_lock(&rba->lock);
	atomic_set(&rba->req_pending, 0);
	atomic_set(&rba->req_ready, 0);
	INIT_LIST_HEAD(&rba->rbd_allocated);
	INIT_LIST_HEAD(&rba->rbd_empty);
	spin_unlock(&rba->lock);

	/* free all first - we might be reconfigured for a different size */
	iwl_pcie_free_rbs_pool(trans);

	for (i = 0; i < RX_QUEUE_SIZE; i++)
		def_rxq->queue[i] = NULL;

	for (i = 0; i < trans->num_rx_queues; i++) {
		struct iwl_rxq *rxq = &trans_pcie->rxq[i];

		rxq->id = i;

		spin_lock(&rxq->lock);
		/*
		 * Set read write pointer to reflect that we have processed
		 * and used all buffers, but have not restocked the Rx queue
		 * with fresh buffers
		 */
		rxq->read = 0;
		rxq->write = 0;
		rxq->write_actual = 0;
		memset(rxq->rb_stts, 0, sizeof(*rxq->rb_stts));

		iwl_pcie_rx_init_rxb_lists(rxq);

		if (!rxq->napi.poll)
			netif_napi_add(&trans_pcie->napi_dev, &rxq->napi,
				       iwl_pcie_dummy_napi_poll, 64);

		spin_unlock(&rxq->lock);
	}

	/* move the pool to the default queue and allocator ownerships */
	queue_size = trans->cfg->mq_rx_supported ?
		     MQ_RX_NUM_RBDS : RX_QUEUE_SIZE;
	allocator_pool_size = trans->num_rx_queues *
		(RX_CLAIM_REQ_ALLOC - RX_POST_REQ_ALLOC);
	num_alloc = queue_size + allocator_pool_size;
	BUILD_BUG_ON(ARRAY_SIZE(trans_pcie->global_table) !=
		     ARRAY_SIZE(trans_pcie->rx_pool));
	for (i = 0; i < num_alloc; i++) {
		struct iwl_rx_mem_buffer *rxb = &trans_pcie->rx_pool[i];

		if (i < allocator_pool_size)
			list_add(&rxb->list, &rba->rbd_empty);
		else
			list_add(&rxb->list, &def_rxq->rx_used);
		trans_pcie->global_table[i] = rxb;
		rxb->vid = (u16)(i + 1);
		rxb->invalid = true;
	}

	iwl_pcie_rxq_alloc_rbs(trans, GFP_KERNEL, def_rxq);

	return 0;
}

int iwl_pcie_rx_init(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	int ret = _iwl_pcie_rx_init(trans);

	if (ret)
		return ret;

	if (trans->cfg->mq_rx_supported)
		iwl_pcie_rx_mq_hw_init(trans);
	else
		iwl_pcie_rx_hw_init(trans, trans_pcie->rxq);

	iwl_pcie_rxq_restock(trans, trans_pcie->rxq);

	spin_lock(&trans_pcie->rxq->lock);
	iwl_pcie_rxq_inc_wr_ptr(trans, trans_pcie->rxq);
	spin_unlock(&trans_pcie->rxq->lock);

	return 0;
}

int iwl_pcie_gen2_rx_init(struct iwl_trans *trans)
{
	/*
	 * We don't configure the RFH.
	 * Restock will be done at alive, after firmware configured the RFH.
	 */
	return _iwl_pcie_rx_init(trans);
}

void iwl_pcie_rx_free(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rb_allocator *rba = &trans_pcie->rba;
	int free_size = trans->cfg->mq_rx_supported ? sizeof(__le64) :
					      sizeof(__le32);
	int i;

	/*
	 * if rxq is NULL, it means that nothing has been allocated,
	 * exit now
	 */
	if (!trans_pcie->rxq) {
		IWL_DEBUG_INFO(trans, "Free NULL rx context\n");
		return;
	}

	cancel_work_sync(&rba->rx_alloc);
	if (rba->alloc_wq) {
		destroy_workqueue(rba->alloc_wq);
		rba->alloc_wq = NULL;
	}

	iwl_pcie_free_rbs_pool(trans);

	for (i = 0; i < trans->num_rx_queues; i++) {
		struct iwl_rxq *rxq = &trans_pcie->rxq[i];

		if (rxq->bd)
			dma_free_coherent(trans->dev,
					  free_size * rxq->queue_size,
					  rxq->bd, rxq->bd_dma);
		rxq->bd_dma = 0;
		rxq->bd = NULL;

		if (rxq->rb_stts)
			dma_free_coherent(trans->dev,
					  sizeof(struct iwl_rb_status),
					  rxq->rb_stts, rxq->rb_stts_dma);
		else
			IWL_DEBUG_INFO(trans,
				       "Free rxq->rb_stts which is NULL\n");

		if (rxq->used_bd)
			dma_free_coherent(trans->dev,
					  sizeof(__le32) * rxq->queue_size,
					  rxq->used_bd, rxq->used_bd_dma);
		rxq->used_bd_dma = 0;
		rxq->used_bd = NULL;

		if (rxq->napi.poll)
			netif_napi_del(&rxq->napi);
	}
	kfree(trans_pcie->rxq);
}

/*
 * iwl_pcie_rx_reuse_rbd - Recycle used RBDs
 *
 * Called when a RBD can be reused. The RBD is transferred to the allocator.
 * When there are 2 empty RBDs - a request for allocation is posted
 */
static void iwl_pcie_rx_reuse_rbd(struct iwl_trans *trans,
				  struct iwl_rx_mem_buffer *rxb,
				  struct iwl_rxq *rxq, bool emergency)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rb_allocator *rba = &trans_pcie->rba;

	/* Move the RBD to the used list, will be moved to allocator in batches
	 * before claiming or posting a request*/
	list_add_tail(&rxb->list, &rxq->rx_used);

	if (unlikely(emergency))
		return;

	/* Count the allocator owned RBDs */
	rxq->used_count++;

	/* If we have RX_POST_REQ_ALLOC new released rx buffers -
	 * issue a request for allocator. Modulo RX_CLAIM_REQ_ALLOC is
	 * used for the case we failed to claim RX_CLAIM_REQ_ALLOC,
	 * after but we still need to post another request.
	 */
	if ((rxq->used_count % RX_CLAIM_REQ_ALLOC) == RX_POST_REQ_ALLOC) {
		/* Move the 2 RBDs to the allocator ownership.
		 Allocator has another 6 from pool for the request completion*/
		spin_lock(&rba->lock);
		list_splice_tail_init(&rxq->rx_used, &rba->rbd_empty);
		spin_unlock(&rba->lock);

		atomic_inc(&rba->req_pending);
		queue_work(rba->alloc_wq, &rba->rx_alloc);
	}
}

static void iwl_pcie_rx_handle_rb(struct iwl_trans *trans,
				struct iwl_rxq *rxq,
				struct iwl_rx_mem_buffer *rxb,
				bool emergency)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_txq *txq = trans_pcie->txq[trans_pcie->cmd_queue];
	bool page_stolen = false;
	int max_len = PAGE_SIZE << trans_pcie->rx_page_order;
	u32 offset = 0;

	if (WARN_ON(!rxb))
		return;

	dma_unmap_page(trans->dev, rxb->page_dma, max_len, DMA_FROM_DEVICE);

	while (offset + sizeof(u32) + sizeof(struct iwl_cmd_header) < max_len) {
		struct iwl_rx_packet *pkt;
		u16 sequence;
		bool reclaim;
		int index, cmd_index, len;
		struct iwl_rx_cmd_buffer rxcb = {
			._offset = offset,
			._rx_page_order = trans_pcie->rx_page_order,
			._page = rxb->page,
			._page_stolen = false,
			.truesize = max_len,
		};

		pkt = rxb_addr(&rxcb);

		if (pkt->len_n_flags == cpu_to_le32(FH_RSCSR_FRAME_INVALID))
			break;

		WARN_ON((le32_to_cpu(pkt->len_n_flags) & FH_RSCSR_RXQ_MASK) >>
			FH_RSCSR_RXQ_POS != rxq->id);

		IWL_DEBUG_RX(trans,
			     "cmd at offset %d: %s (%.2x.%2x, seq 0x%x)\n",
			     rxcb._offset,
			     iwl_get_cmd_string(trans,
						iwl_cmd_id(pkt->hdr.cmd,
							   pkt->hdr.group_id,
							   0)),
			     pkt->hdr.group_id, pkt->hdr.cmd,
			     le16_to_cpu(pkt->hdr.sequence));

		len = iwl_rx_packet_len(pkt);
		len += sizeof(u32); /* account for status word */
		trace_iwlwifi_dev_rx(trans->dev, trans, pkt, len);
		trace_iwlwifi_dev_rx_data(trans->dev, trans, pkt, len);

		/* Reclaim a command buffer only if this packet is a response
		 *   to a (driver-originated) command.
		 * If the packet (e.g. Rx frame) originated from uCode,
		 *   there is no command buffer to reclaim.
		 * Ucode should set SEQ_RX_FRAME bit if ucode-originated,
		 *   but apparently a few don't get set; catch them here. */
		reclaim = !(pkt->hdr.sequence & SEQ_RX_FRAME);
		if (reclaim) {
			int i;

			for (i = 0; i < trans_pcie->n_no_reclaim_cmds; i++) {
				if (trans_pcie->no_reclaim_cmds[i] ==
							pkt->hdr.cmd) {
					reclaim = false;
					break;
				}
			}
		}

		sequence = le16_to_cpu(pkt->hdr.sequence);
		index = SEQ_TO_INDEX(sequence);
		cmd_index = get_cmd_index(txq, index);

		if (rxq->id == 0)
			iwl_op_mode_rx(trans->op_mode, &rxq->napi,
				       &rxcb);
		else
			iwl_op_mode_rx_rss(trans->op_mode, &rxq->napi,
					   &rxcb, rxq->id);

		if (reclaim) {
			kzfree(txq->entries[cmd_index].free_buf);
			txq->entries[cmd_index].free_buf = NULL;
		}

		/*
		 * After here, we should always check rxcb._page_stolen,
		 * if it is true then one of the handlers took the page.
		 */

		if (reclaim) {
			/* Invoke any callbacks, transfer the buffer to caller,
			 * and fire off the (possibly) blocking
			 * iwl_trans_send_cmd()
			 * as we reclaim the driver command queue */
			if (!rxcb._page_stolen)
				iwl_pcie_hcmd_complete(trans, &rxcb);
			else
				IWL_WARN(trans, "Claim null rxb?\n");
		}

		page_stolen |= rxcb._page_stolen;
		offset += ALIGN(len, FH_RSCSR_FRAME_ALIGN);
	}

	/* page was stolen from us -- free our reference */
	if (page_stolen) {
		__free_pages(rxb->page, trans_pcie->rx_page_order);
		rxb->page = NULL;
	}

	/* Reuse the page if possible. For notification packets and
	 * SKBs that fail to Rx correctly, add them back into the
	 * rx_free list for reuse later. */
	if (rxb->page != NULL) {
		rxb->page_dma =
			dma_map_page(trans->dev, rxb->page, 0,
				     PAGE_SIZE << trans_pcie->rx_page_order,
				     DMA_FROM_DEVICE);
		if (dma_mapping_error(trans->dev, rxb->page_dma)) {
			/*
			 * free the page(s) as well to not break
			 * the invariant that the items on the used
			 * list have no page(s)
			 */
			__free_pages(rxb->page, trans_pcie->rx_page_order);
			rxb->page = NULL;
			iwl_pcie_rx_reuse_rbd(trans, rxb, rxq, emergency);
		} else {
			list_add_tail(&rxb->list, &rxq->rx_free);
			rxq->free_count++;
		}
	} else
		iwl_pcie_rx_reuse_rbd(trans, rxb, rxq, emergency);
}

/*
 * iwl_pcie_rx_handle - Main entry function for receiving responses from fw
 */
static void iwl_pcie_rx_handle(struct iwl_trans *trans, int queue)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct iwl_rxq *rxq = &trans_pcie->rxq[queue];
	u32 r, i, count = 0;
	bool emergency = false;

restart:
	spin_lock(&rxq->lock);
	/* uCode's read index (stored in shared DRAM) indicates the last Rx
	 * buffer that the driver may process (last buffer filled by ucode). */
	r = le16_to_cpu(ACCESS_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF;
	i = rxq->read;

	/* W/A 9000 device step A0 wrap-around bug */
	r &= (rxq->queue_size - 1);

	/* Rx interrupt, but nothing sent from uCode */
	if (i == r)
		IWL_DEBUG_RX(trans, "Q %d: HW = SW = %d\n", rxq->id, r);

	while (i != r) {
		struct iwl_rx_mem_buffer *rxb;

		if (unlikely(rxq->used_count == rxq->queue_size / 2))
			emergency = true;

		if (trans->cfg->mq_rx_supported) {
			/*
			 * used_bd is a 32 bit but only 12 are used to retrieve
			 * the vid
			 */
			u16 vid = le32_to_cpu(rxq->used_bd[i]) & 0x0FFF;

			if (WARN(!vid ||
				 vid > ARRAY_SIZE(trans_pcie->global_table),
				 "Invalid rxb index from HW %u\n", (u32)vid)) {
				iwl_force_nmi(trans);
				goto out;
			}
			rxb = trans_pcie->global_table[vid - 1];
			if (WARN(rxb->invalid,
				 "Invalid rxb from HW %u\n", (u32)vid)) {
				iwl_force_nmi(trans);
				goto out;
			}
			rxb->invalid = true;
		} else {
			rxb = rxq->queue[i];
			rxq->queue[i] = NULL;
		}

		IWL_DEBUG_RX(trans, "Q %d: HW = %d, SW = %d\n", rxq->id, r, i);
		iwl_pcie_rx_handle_rb(trans, rxq, rxb, emergency);

		i = (i + 1) & (rxq->queue_size - 1);

		/*
		 * If we have RX_CLAIM_REQ_ALLOC released rx buffers -
		 * try to claim the pre-allocated buffers from the allocator.
		 * If not ready - will try to reclaim next time.
		 * There is no need to reschedule work - allocator exits only
		 * on success
		 */
		if (rxq->used_count >= RX_CLAIM_REQ_ALLOC)
			iwl_pcie_rx_allocator_get(trans, rxq);

		if (rxq->used_count % RX_CLAIM_REQ_ALLOC == 0 && !emergency) {
			struct iwl_rb_allocator *rba = &trans_pcie->rba;

			/* Add the remaining empty RBDs for allocator use */
			spin_lock(&rba->lock);
			list_splice_tail_init(&rxq->rx_used, &rba->rbd_empty);
			spin_unlock(&rba->lock);
		} else if (emergency) {
			count++;
			if (count == 8) {
				count = 0;
				if (rxq->used_count < rxq->queue_size / 3)
					emergency = false;

				rxq->read = i;
				spin_unlock(&rxq->lock);
				iwl_pcie_rxq_alloc_rbs(trans, GFP_ATOMIC, rxq);
				iwl_pcie_rxq_restock(trans, rxq);
				goto restart;
			}
		}
	}
out:
	/* Backtrack one entry */
	rxq->read = i;
	spin_unlock(&rxq->lock);

	/*
	 * handle a case where in emergency there are some unallocated RBDs.
	 * those RBDs are in the used list, but are not tracked by the queue's
	 * used_count which counts allocator owned RBDs.
	 * unallocated emergency RBDs must be allocated on exit, otherwise
	 * when called again the function may not be in emergency mode and
	 * they will be handed to the allocator with no tracking in the RBD
	 * allocator counters, which will lead to them never being claimed back
	 * by the queue.
	 * by allocating them here, they are now in the queue free list, and
	 * will be restocked by the next call of iwl_pcie_rxq_restock.
	 */
	if (unlikely(emergency && count))
		iwl_pcie_rxq_alloc_rbs(trans, GFP_ATOMIC, rxq);

	if (rxq->napi.poll)
		napi_gro_flush(&rxq->napi, false);

	iwl_pcie_rxq_restock(trans, rxq);
}

static struct iwl_trans_pcie *iwl_pcie_get_trans_pcie(struct msix_entry *entry)
{
	u8 queue = entry->entry;
	struct msix_entry *entries = entry - queue;

	return container_of(entries, struct iwl_trans_pcie, msix_entries[0]);
}

static inline void iwl_pcie_clear_irq(struct iwl_trans *trans,
				      struct msix_entry *entry)
{
	/*
	 * Before sending the interrupt the HW disables it to prevent
	 * a nested interrupt. This is done by writing 1 to the corresponding
	 * bit in the mask register. After handling the interrupt, it should be
	 * re-enabled by clearing this bit. This register is defined as
	 * write 1 clear (W1C) register, meaning that it's being clear
	 * by writing 1 to the bit.
	 */
	iwl_write32(trans, CSR_MSIX_AUTOMASK_ST_AD, BIT(entry->entry));
}

/*
 * iwl_pcie_rx_msix_handle - Main entry function for receiving responses from fw
 * This interrupt handler should be used with RSS queue only.
 */
irqreturn_t iwl_pcie_irq_rx_msix_handler(int irq, void *dev_id)
{
	struct msix_entry *entry = dev_id;
	struct iwl_trans_pcie *trans_pcie = iwl_pcie_get_trans_pcie(entry);
	struct iwl_trans *trans = trans_pcie->trans;

	if (WARN_ON(entry->entry >= trans->num_rx_queues))
		return IRQ_NONE;

	lock_map_acquire(&trans->sync_cmd_lockdep_map);

	local_bh_disable();
	iwl_pcie_rx_handle(trans, entry->entry);
	local_bh_enable();

	iwl_pcie_clear_irq(trans, entry);

	lock_map_release(&trans->sync_cmd_lockdep_map);

	return IRQ_HANDLED;
}

/*
 * iwl_pcie_irq_handle_error - called for HW or SW error interrupt from card
 */
static void iwl_pcie_irq_handle_error(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	int i;

	/* W/A for WiFi/WiMAX coex and WiMAX own the RF */
	if (trans->cfg->internal_wimax_coex &&
	    !trans->cfg->apmg_not_supported &&
	    (!(iwl_read_prph(trans, APMG_CLK_CTRL_REG) &
			     APMS_CLK_VAL_MRB_FUNC_MODE) ||
	     (iwl_read_prph(trans, APMG_PS_CTRL_REG) &
			    APMG_PS_CTRL_VAL_RESET_REQ))) {
		clear_bit(STATUS_SYNC_HCMD_ACTIVE, &trans->status);
		iwl_op_mode_wimax_active(trans->op_mode);
		wake_up(&trans_pcie->wait_command_queue);
		return;
	}

	local_bh_disable();
	/* The STATUS_FW_ERROR bit is set in this function. This must happen
	 * before we wake up the command caller, to ensure a proper cleanup. */
	iwl_trans_fw_error(trans);
	local_bh_enable();

	for (i = 0; i < trans->cfg->base_params->num_of_queues; i++) {
		if (!trans_pcie->txq[i])
			continue;
		del_timer(&trans_pcie->txq[i]->stuck_timer);
	}

	clear_bit(STATUS_SYNC_HCMD_ACTIVE, &trans->status);
	wake_up(&trans_pcie->wait_command_queue);
}

static u32 iwl_pcie_int_cause_non_ict(struct iwl_trans *trans)
{
	u32 inta;

	lockdep_assert_held(&IWL_TRANS_GET_PCIE_TRANS(trans)->irq_lock);

	trace_iwlwifi_dev_irq(trans->dev);

	/* Discover which interrupts are active/pending */
	inta = iwl_read32(trans, CSR_INT);

	/* the thread will service interrupts and re-enable them */
	return inta;
}

/* a device (PCI-E) page is 4096 bytes long */
#define ICT_SHIFT	12
#define ICT_SIZE	(1 << ICT_SHIFT)
#define ICT_COUNT	(ICT_SIZE / sizeof(u32))

/* interrupt handler using ict table, with this interrupt driver will
 * stop using INTA register to get device's interrupt, reading this register
 * is expensive, device will write interrupts in ICT dram table, increment
 * index then will fire interrupt to driver, driver will OR all ICT table
 * entries from current index up to table entry with 0 value. the result is
 * the interrupt we need to service, driver will set the entries back to 0 and
 * set index.
 */
static u32 iwl_pcie_int_cause_ict(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	u32 inta;
	u32 val = 0;
	u32 read;

	trace_iwlwifi_dev_irq(trans->dev);

	/* Ignore interrupt if there's nothing in NIC to service.
	 * This may be due to IRQ shared with another device,
	 * or due to sporadic interrupts thrown from our NIC. */
	read = le32_to_cpu(trans_pcie->ict_tbl[trans_pcie->ict_index]);
	trace_iwlwifi_dev_ict_read(trans->dev, trans_pcie->ict_index, read);
	if (!read)
		return 0;

	/*
	 * Collect all entries up to the first 0, starting from ict_index;
	 * note we already read at ict_index.
	 */
	do {
		val |= read;
		IWL_DEBUG_ISR(trans, "ICT index %d value 0x%08X\n",
				trans_pcie->ict_index, read);
		trans_pcie->ict_tbl[trans_pcie->ict_index] = 0;
		trans_pcie->ict_index =
			((trans_pcie->ict_index + 1) & (ICT_COUNT - 1));

		read = le32_to_cpu(trans_pcie->ict_tbl[trans_pcie->ict_index]);
		trace_iwlwifi_dev_ict_read(trans->dev, trans_pcie->ict_index,
					   read);
	} while (read);

	/* We should not get this value, just ignore it. */
	if (val == 0xffffffff)
		val = 0;

	/*
	 * this is a w/a for a h/w bug. the h/w bug may cause the Rx bit
	 * (bit 15 before shifting it to 31) to clear when using interrupt
	 * coalescing. fortunately, bits 18 and 19 stay set when this happens
	 * so we use them to decide on the real state of the Rx bit.
	 * In order words, bit 15 is set if bit 18 or bit 19 are set.
	 */
	if (val & 0xC0000)
		val |= 0x8000;

	inta = (0xff & val) | ((0xff00 & val) << 16);
	return inta;
}

irqreturn_t iwl_pcie_irq_handler(int irq, void *dev_id)
{
	struct iwl_trans *trans = dev_id;
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	struct isr_statistics *isr_stats = &trans_pcie->isr_stats;
	u32 inta = 0;
	u32 handled = 0;

	lock_map_acquire(&trans->sync_cmd_lockdep_map);

	spin_lock(&trans_pcie->irq_lock);

	/* dram interrupt table not set yet,
	 * use legacy interrupt.
	 */
	if (likely(trans_pcie->use_ict))
		inta = iwl_pcie_int_cause_ict(trans);
	else
		inta = iwl_pcie_int_cause_non_ict(trans);

	if (iwl_have_debug_level(IWL_DL_ISR)) {
		IWL_DEBUG_ISR(trans,
			      "ISR inta 0x%08x, enabled 0x%08x(sw), enabled(hw) 0x%08x, fh 0x%08x\n",
			      inta, trans_pcie->inta_mask,
			      iwl_read32(trans, CSR_INT_MASK),
			      iwl_read32(trans, CSR_FH_INT_STATUS));
		if (inta & (~trans_pcie->inta_mask))
			IWL_DEBUG_ISR(trans,
				      "We got a masked interrupt (0x%08x)\n",
				      inta & (~trans_pcie->inta_mask));
	}

	inta &= trans_pcie->inta_mask;

	/*
	 * Ignore interrupt if there's nothing in NIC to service.
	 * This may be due to IRQ shared with another device,
	 * or due to sporadic interrupts thrown from our NIC.
	 */
	if (unlikely(!inta)) {
		IWL_DEBUG_ISR(trans, "Ignore interrupt, inta == 0\n");
		/*
		 * Re-enable interrupts here since we don't
		 * have anything to service
		 */
		if (test_bit(STATUS_INT_ENABLED, &trans->status))
			_iwl_enable_interrupts(trans);
		spin_unlock(&trans_pcie->irq_lock);
		lock_map_release(&trans->sync_cmd_lockdep_map);
		return IRQ_NONE;
	}

	if (unlikely(inta == 0xFFFFFFFF || (inta & 0xFFFFFFF0) == 0xa5a5a5a0)) {
		/*
		 * Hardware disappeared. It might have
		 * already raised an interrupt.
		 */
		IWL_WARN(trans, "HARDWARE GONE?? INTA == 0x%08x\n", inta);
		spin_unlock(&trans_pcie->irq_lock);
		goto out;
	}

	/* Ack/clear/reset pending uCode interrupts.
	 * Note:  Some bits in CSR_INT are "OR" of bits in CSR_FH_INT_STATUS,
	 */
	/* There is a hardware bug in the interrupt mask function that some
	 * interrupts (i.e. CSR_INT_BIT_SCD) can still be generated even if
	 * they are disabled in the CSR_INT_MASK register. Furthermore the
	 * ICT interrupt handling mechanism has another bug that might cause
	 * these unmasked interrupts fail to be detected. We workaround the
	 * hardware bugs here by ACKing all the possible interrupts so that
	 * interrupt coalescing can still be achieved.
	 */
	iwl_write32(trans, CSR_INT, inta | ~trans_pcie->inta_mask);

	if (iwl_have_debug_level(IWL_DL_ISR))
		IWL_DEBUG_ISR(trans, "inta 0x%08x, enabled 0x%08x\n",
			      inta, iwl_read32(trans, CSR_INT_MASK));

	spin_unlock(&trans_pcie->irq_lock);

	/* Now service all interrupt bits discovered above. */
	if (inta & CSR_INT_BIT_HW_ERR) {
		IWL_ERR(trans, "Hardware error detected.  Restarting.\n");

		/* Tell the device to stop sending interrupts */
		iwl_disable_interrupts(trans);

		isr_stats->hw++;
		iwl_pcie_irq_handle_error(trans);

		handled |= CSR_INT_BIT_HW_ERR;

		goto out;
	}

	if (iwl_have_debug_level(IWL_DL_ISR)) {
		/* NIC fires this, but we don't use it, redundant with WAKEUP */
		if (inta & CSR_INT_BIT_SCD) {
			IWL_DEBUG_ISR(trans,
				      "Scheduler finished to transmit the frame/frames.\n");
			isr_stats->sch++;
		}

		/* Alive notification via Rx interrupt will do the real work */
		if (inta & CSR_INT_BIT_ALIVE) {
			IWL_DEBUG_ISR(trans, "Alive interrupt\n");
			isr_stats->alive++;
			if (trans->cfg->gen2) {
				/*
				 * We can restock, since firmware configured
				 * the RFH
				 */
				iwl_pcie_rxmq_restock(trans, trans_pcie->rxq);
			}
		}
	}

	/* Safely ignore these bits for debug checks below */
	inta &= ~(CSR_INT_BIT_SCD | CSR_INT_BIT_ALIVE);

	/* HW RF KILL switch toggled */
	if (inta & CSR_INT_BIT_RF_KILL) {
		bool hw_rfkill;

		mutex_lock(&trans_pcie->mutex);
		hw_rfkill = iwl_is_rfkill_set(trans);
		if (hw_rfkill)
			set_bit(STATUS_RFKILL, &trans->status);

		IWL_WARN(trans, "RF_KILL bit toggled to %s.\n",
			 hw_rfkill ? "disable radio" : "enable radio");

		isr_stats->rfkill++;

		iwl_trans_pcie_rf_kill(trans, hw_rfkill);
		mutex_unlock(&trans_pcie->mutex);
		if (hw_rfkill) {
			if (test_and_clear_bit(STATUS_SYNC_HCMD_ACTIVE,
					       &trans->status))
				IWL_DEBUG_RF_KILL(trans,
						  "Rfkill while SYNC HCMD in flight\n");
			wake_up(&trans_pcie->wait_command_queue);
		} else {
			clear_bit(STATUS_RFKILL, &trans->status);
		}

		handled |= CSR_INT_BIT_RF_KILL;
	}

	/* Chip got too hot and stopped itself */
	if (inta & CSR_INT_BIT_CT_KILL) {
		IWL_ERR(trans, "Microcode CT kill error detected.\n");
		isr_stats->ctkill++;
		handled |= CSR_INT_BIT_CT_KILL;
	}

	/* Error detected by uCode */
	if (inta & CSR_INT_BIT_SW_ERR) {
		IWL_ERR(trans, "Microcode SW error detected. "
			" Restarting 0x%X.\n", inta);
		isr_stats->sw++;
		iwl_pcie_irq_handle_error(trans);
		handled |= CSR_INT_BIT_SW_ERR;
	}

	/* uCode wakes up after power-down sleep */
	if (inta & CSR_INT_BIT_WAKEUP) {
		IWL_DEBUG_ISR(trans, "Wakeup interrupt\n");
		iwl_pcie_rxq_check_wrptr(trans);
		iwl_pcie_txq_check_wrptrs(trans);

		isr_stats->wakeup++;

		handled |= CSR_INT_BIT_WAKEUP;
	}

	/* All uCode command responses, including Tx command responses,
	 * Rx "responses" (frame-received notification), and other
	 * notifications from uCode come through here*/
	if (inta & (CSR_INT_BIT_FH_RX | CSR_INT_BIT_SW_RX |
		    CSR_INT_BIT_RX_PERIODIC)) {
		IWL_DEBUG_ISR(trans, "Rx interrupt\n");
		if (inta & (CSR_INT_BIT_FH_RX | CSR_INT_BIT_SW_RX)) {
			handled |= (CSR_INT_BIT_FH_RX | CSR_INT_BIT_SW_RX);
			iwl_write32(trans, CSR_FH_INT_STATUS,
					CSR_FH_INT_RX_MASK);
		}
		if (inta & CSR_INT_BIT_RX_PERIODIC) {
			handled |= CSR_INT_BIT_RX_PERIODIC;
			iwl_write32(trans,
				CSR_INT, CSR_INT_BIT_RX_PERIODIC);
		}
		/* Sending RX interrupt require many steps to be done in the
		 * the device:
		 * 1- write interrupt to current index in ICT table.
		 * 2- dma RX frame.
		 * 3- update RX shared data to indicate last write index.
		 * 4- send interrupt.
		 * This could lead to RX race, driver could receive RX interrupt
		 * but the shared data changes does not reflect this;
		 * periodic interrupt will detect any dangling Rx activity.
		 */

		/* Disable periodic interrupt; we use it as just a one-shot. */
		iwl_write8(trans, CSR_INT_PERIODIC_REG,
			    CSR_INT_PERIODIC_DIS);

		/*
		 * Enable periodic interrupt in 8 msec only if we received
		 * real RX interrupt (instead of just periodic int), to catch
		 * any dangling Rx interrupt.  If it was just the periodic
		 * interrupt, there was no dangling Rx activity, and no need
		 * to extend the periodic interrupt; one-shot is enough.
		 */
		if (inta & (CSR_INT_BIT_FH_RX | CSR_INT_BIT_SW_RX))
			iwl_write8(trans, CSR_INT_PERIODIC_REG,
				   CSR_INT_PERIODIC_ENA);

		isr_stats->rx++;

		local_bh_disable();
		iwl_pcie_rx_handle(trans, 0);
		local_bh_enable();
	}

	/* This "Tx" DMA channel is used only for loading uCode */
	if (inta & CSR_INT_BIT_FH_TX) {
		iwl_write32(trans, CSR_FH_INT_STATUS, CSR_FH_INT_TX_MASK);
		IWL_DEBUG_ISR(trans, "uCode load interrupt\n");
		isr_stats->tx++;
		handled |= CSR_INT_BIT_FH_TX;
		/* Wake up uCode load routine, now that load is complete */
		trans_pcie->ucode_write_complete = true;
		wake_up(&trans_pcie->ucode_write_waitq);
	}

	if (inta & ~handled) {
		IWL_ERR(trans, "Unhandled INTA bits 0x%08x\n", inta & ~handled);
		isr_stats->unhandled++;
	}

	if (inta & ~(trans_pcie->inta_mask)) {
		IWL_WARN(trans, "Disabled INTA bits 0x%08x were pending\n",
			 inta & ~trans_pcie->inta_mask);
	}

	spin_lock(&trans_pcie->irq_lock);
	/* only Re-enable all interrupt if disabled by irq */
	if (test_bit(STATUS_INT_ENABLED, &trans->status))
		_iwl_enable_interrupts(trans);
	/* we are loading the firmware, enable FH_TX interrupt only */
	else if (handled & CSR_INT_BIT_FH_TX)
		iwl_enable_fw_load_int(trans);
	/* Re-enable RF_KILL if it occurred */
	else if (handled & CSR_INT_BIT_RF_KILL)
		iwl_enable_rfkill_int(trans);
	spin_unlock(&trans_pcie->irq_lock);

out:
	lock_map_release(&trans->sync_cmd_lockdep_map);
	return IRQ_HANDLED;
}

/******************************************************************************
 *
 * ICT functions
 *
 ******************************************************************************/

/* Free dram table */
void iwl_pcie_free_ict(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

	if (trans_pcie->ict_tbl) {
		dma_free_coherent(trans->dev, ICT_SIZE,
				  trans_pcie->ict_tbl,
				  trans_pcie->ict_tbl_dma);
		trans_pcie->ict_tbl = NULL;
		trans_pcie->ict_tbl_dma = 0;
	}
}

/*
 * allocate dram shared table, it is an aligned memory
 * block of ICT_SIZE.
 * also reset all data related to ICT table interrupt.
 */
int iwl_pcie_alloc_ict(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

	trans_pcie->ict_tbl =
		dma_zalloc_coherent(trans->dev, ICT_SIZE,
				   &trans_pcie->ict_tbl_dma,
				   GFP_KERNEL);
	if (!trans_pcie->ict_tbl)
		return -ENOMEM;

	/* just an API sanity check ... it is guaranteed to be aligned */
	if (WARN_ON(trans_pcie->ict_tbl_dma & (ICT_SIZE - 1))) {
		iwl_pcie_free_ict(trans);
		return -EINVAL;
	}

	return 0;
}

/* Device is going up inform it about using ICT interrupt table,
 * also we need to tell the driver to start using ICT interrupt.
 */
void iwl_pcie_reset_ict(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
	u32 val;

	if (!trans_pcie->ict_tbl)
		return;

	spin_lock(&trans_pcie->irq_lock);
	_iwl_disable_interrupts(trans);

	memset(trans_pcie->ict_tbl, 0, ICT_SIZE);

	val = trans_pcie->ict_tbl_dma >> ICT_SHIFT;

	val |= CSR_DRAM_INT_TBL_ENABLE |
	       CSR_DRAM_INIT_TBL_WRAP_CHECK |
	       CSR_DRAM_INIT_TBL_WRITE_POINTER;

	IWL_DEBUG_ISR(trans, "CSR_DRAM_INT_TBL_REG =0x%x\n", val);

	iwl_write32(trans, CSR_DRAM_INT_TBL_REG, val);
	trans_pcie->use_ict = true;
	trans_pcie->ict_index = 0;
	iwl_write32(trans, CSR_INT, trans_pcie->inta_mask);
	_iwl_enable_interrupts(trans);
	spin_unlock(&trans_pcie->irq_lock);
}

/* Device is going down disable ict interrupt usage */
void iwl_pcie_disable_ict(struct iwl_trans *trans)
{
	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

	spin_lock(&trans_pcie->irq_lock);
	trans_pcie->use_ict = false;
	spin_unlock(&trans_pcie->irq_lock);
}

irqreturn_t iwl_pcie_isr(int irq, void *data)
{
	struct iwl_trans *trans = data;

	if (!trans)
		return IRQ_NONE;

	/* Disable (but don't clear!) interrupts here to avoid
	 * back-to-back ISRs and sporadic interrupts from our NIC.
	 * If we have something to service, the tasklet will re-enable ints.
	 * If we *don't* have something, we'll re-enable before leaving here.
	 */
	iwl_write32(trans, CSR_INT_MASK, 0x00000000);

	return IRQ_WAKE_THREAD;
}

irqreturn_t iwl_pcie_msix_isr(int irq, void *data)
{
	return IRQ_WAKE_THREAD;
}

irqreturn_t iwl_pcie_irq_msix_handler(int irq, void *dev_id)
{
	struct msix_entry *entry = dev_id;
	struct iwl_trans_pcie *trans_pcie = iwl_pcie_get_trans_pcie(entry);
	struct iwl_trans *trans = trans_pcie->trans;
	struct isr_statistics *isr_stats = &trans_pcie->isr_stats;
	u32 inta_fh, inta_hw;

	lock_map_acquire(&trans->sync_cmd_lockdep_map);

	spin_lock(&trans_pcie->irq_lock);
	inta_fh = iwl_read32(trans, CSR_MSIX_FH_INT_CAUSES_AD);
	inta_hw = iwl_read32(trans, CSR_MSIX_HW_INT_CAUSES_AD);
	/*
	 * Clear causes registers to avoid being handling the same cause.
	 */
	iwl_write32(trans, CSR_MSIX_FH_INT_CAUSES_AD, inta_fh);
	iwl_write32(trans, CSR_MSIX_HW_INT_CAUSES_AD, inta_hw);
	spin_unlock(&trans_pcie->irq_lock);

	if (unlikely(!(inta_fh | inta_hw))) {
		IWL_DEBUG_ISR(trans, "Ignore interrupt, inta == 0\n");
		lock_map_release(&trans->sync_cmd_lockdep_map);
		return IRQ_NONE;
	}

	if (iwl_have_debug_level(IWL_DL_ISR))
		IWL_DEBUG_ISR(trans, "ISR inta_fh 0x%08x, enabled 0x%08x\n",
			      inta_fh,
			      iwl_read32(trans, CSR_MSIX_FH_INT_MASK_AD));

	if ((trans_pcie->shared_vec_mask & IWL_SHARED_IRQ_NON_RX) &&
	    inta_fh & MSIX_FH_INT_CAUSES_Q0) {
		local_bh_disable();
		iwl_pcie_rx_handle(trans, 0);
		local_bh_enable();
	}

	if ((trans_pcie->shared_vec_mask & IWL_SHARED_IRQ_FIRST_RSS) &&
	    inta_fh & MSIX_FH_INT_CAUSES_Q1) {
		local_bh_disable();
		iwl_pcie_rx_handle(trans, 1);
		local_bh_enable();
	}

	/* This "Tx" DMA channel is used only for loading uCode */
	if (inta_fh & MSIX_FH_INT_CAUSES_D2S_CH0_NUM) {
		IWL_DEBUG_ISR(trans, "uCode load interrupt\n");
		isr_stats->tx++;
		/*
		 * Wake up uCode load routine,
		 * now that load is complete
		 */
		trans_pcie->ucode_write_complete = true;
		wake_up(&trans_pcie->ucode_write_waitq);
	}

	/* Error detected by uCode */
	if ((inta_fh & MSIX_FH_INT_CAUSES_FH_ERR) ||
	    (inta_hw & MSIX_HW_INT_CAUSES_REG_SW_ERR)) {
		IWL_ERR(trans,
			"Microcode SW error detected. Restarting 0x%X.\n",
			inta_fh);
		isr_stats->sw++;
		iwl_pcie_irq_handle_error(trans);
	}

	/* After checking FH register check HW register */
	if (iwl_have_debug_level(IWL_DL_ISR))
		IWL_DEBUG_ISR(trans,
			      "ISR inta_hw 0x%08x, enabled 0x%08x\n",
			      inta_hw,
			      iwl_read32(trans, CSR_MSIX_HW_INT_MASK_AD));

	/* Alive notification via Rx interrupt will do the real work */
	if (inta_hw & MSIX_HW_INT_CAUSES_REG_ALIVE) {
		IWL_DEBUG_ISR(trans, "Alive interrupt\n");
		isr_stats->alive++;
		if (trans->cfg->gen2) {
			/* We can restock, since firmware configured the RFH */
			iwl_pcie_rxmq_restock(trans, trans_pcie->rxq);
		}
	}

	/* uCode wakes up after power-down sleep */
	if (inta_hw & MSIX_HW_INT_CAUSES_REG_WAKEUP) {
		IWL_DEBUG_ISR(trans, "Wakeup interrupt\n");
		iwl_pcie_rxq_check_wrptr(trans);
		iwl_pcie_txq_check_wrptrs(trans);

		isr_stats->wakeup++;
	}

	/* Chip got too hot and stopped itself */
	if (inta_hw & MSIX_HW_INT_CAUSES_REG_CT_KILL) {
		IWL_ERR(trans, "Microcode CT kill error detected.\n");
		isr_stats->ctkill++;
	}

	/* HW RF KILL switch toggled */
	if (inta_hw & MSIX_HW_INT_CAUSES_REG_RF_KILL) {
		bool hw_rfkill;

		mutex_lock(&trans_pcie->mutex);
		hw_rfkill = iwl_is_rfkill_set(trans);
		if (hw_rfkill)
			set_bit(STATUS_RFKILL, &trans->status);

		IWL_WARN(trans, "RF_KILL bit toggled to %s.\n",
			 hw_rfkill ? "disable radio" : "enable radio");

		isr_stats->rfkill++;

		iwl_trans_pcie_rf_kill(trans, hw_rfkill);
		mutex_unlock(&trans_pcie->mutex);
		if (hw_rfkill) {
			if (test_and_clear_bit(STATUS_SYNC_HCMD_ACTIVE,
					       &trans->status))
				IWL_DEBUG_RF_KILL(trans,
						  "Rfkill while SYNC HCMD in flight\n");
			wake_up(&trans_pcie->wait_command_queue);
		} else {
			clear_bit(STATUS_RFKILL, &trans->status);
		}
	}

	if (inta_hw & MSIX_HW_INT_CAUSES_REG_HW_ERR) {
		IWL_ERR(trans,
			"Hardware error detected. Restarting.\n");

		isr_stats->hw++;
		iwl_pcie_irq_handle_error(trans);
	}

	iwl_pcie_clear_irq(trans, entry);

	lock_map_release(&trans->sync_cmd_lockdep_map);

	return IRQ_HANDLED;
}