summaryrefslogtreecommitdiff
path: root/drivers/mmc/core/core.c
blob: a8c17b4cd737927bba95eea34ded3e28587b8084 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/mmc/core/core.c
 *
 *  Copyright (C) 2003-2004 Russell King, All Rights Reserved.
 *  SD support Copyright (C) 2004 Ian Molton, All Rights Reserved.
 *  Copyright (C) 2005-2008 Pierre Ossman, All Rights Reserved.
 *  MMCv4 support Copyright (C) 2006 Philip Langdale, All Rights Reserved.
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/completion.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/pagemap.h>
#include <linux/err.h>
#include <linux/leds.h>
#include <linux/scatterlist.h>
#include <linux/log2.h>
#include <linux/pm_runtime.h>
#include <linux/pm_wakeup.h>
#include <linux/suspend.h>
#include <linux/fault-inject.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/of.h>

#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sd.h>
#include <linux/mmc/slot-gpio.h>

#define CREATE_TRACE_POINTS
#include <trace/events/mmc.h>

#include "core.h"
#include "card.h"
#include "crypto.h"
#include "bus.h"
#include "host.h"
#include "sdio_bus.h"
#include "pwrseq.h"

#include "mmc_ops.h"
#include "sd_ops.h"
#include "sdio_ops.h"

/* The max erase timeout, used when host->max_busy_timeout isn't specified */
#define MMC_ERASE_TIMEOUT_MS	(60 * 1000) /* 60 s */
#define SD_DISCARD_TIMEOUT_MS	(250)

static const unsigned freqs[] = { 400000, 300000, 200000, 100000 };

/*
 * Enabling software CRCs on the data blocks can be a significant (30%)
 * performance cost, and for other reasons may not always be desired.
 * So we allow it to be disabled.
 */
bool use_spi_crc = 1;
module_param(use_spi_crc, bool, 0);

static int mmc_schedule_delayed_work(struct delayed_work *work,
				     unsigned long delay)
{
	/*
	 * We use the system_freezable_wq, because of two reasons.
	 * First, it allows several works (not the same work item) to be
	 * executed simultaneously. Second, the queue becomes frozen when
	 * userspace becomes frozen during system PM.
	 */
	return queue_delayed_work(system_freezable_wq, work, delay);
}

#ifdef CONFIG_FAIL_MMC_REQUEST

/*
 * Internal function. Inject random data errors.
 * If mmc_data is NULL no errors are injected.
 */
static void mmc_should_fail_request(struct mmc_host *host,
				    struct mmc_request *mrq)
{
	struct mmc_command *cmd = mrq->cmd;
	struct mmc_data *data = mrq->data;
	static const int data_errors[] = {
		-ETIMEDOUT,
		-EILSEQ,
		-EIO,
	};

	if (!data)
		return;

	if ((cmd && cmd->error) || data->error ||
	    !should_fail(&host->fail_mmc_request, data->blksz * data->blocks))
		return;

	data->error = data_errors[get_random_u32_below(ARRAY_SIZE(data_errors))];
	data->bytes_xfered = get_random_u32_below(data->bytes_xfered >> 9) << 9;
}

#else /* CONFIG_FAIL_MMC_REQUEST */

static inline void mmc_should_fail_request(struct mmc_host *host,
					   struct mmc_request *mrq)
{
}

#endif /* CONFIG_FAIL_MMC_REQUEST */

static inline void mmc_complete_cmd(struct mmc_request *mrq)
{
	if (mrq->cap_cmd_during_tfr && !completion_done(&mrq->cmd_completion))
		complete_all(&mrq->cmd_completion);
}

void mmc_command_done(struct mmc_host *host, struct mmc_request *mrq)
{
	if (!mrq->cap_cmd_during_tfr)
		return;

	mmc_complete_cmd(mrq);

	pr_debug("%s: cmd done, tfr ongoing (CMD%u)\n",
		 mmc_hostname(host), mrq->cmd->opcode);
}
EXPORT_SYMBOL(mmc_command_done);

/**
 *	mmc_request_done - finish processing an MMC request
 *	@host: MMC host which completed request
 *	@mrq: MMC request which request
 *
 *	MMC drivers should call this function when they have completed
 *	their processing of a request.
 */
void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
{
	struct mmc_command *cmd = mrq->cmd;
	int err = cmd->error;

	/* Flag re-tuning needed on CRC errors */
	if (!mmc_op_tuning(cmd->opcode) &&
	    !host->retune_crc_disable &&
	    (err == -EILSEQ || (mrq->sbc && mrq->sbc->error == -EILSEQ) ||
	    (mrq->data && mrq->data->error == -EILSEQ) ||
	    (mrq->stop && mrq->stop->error == -EILSEQ)))
		mmc_retune_needed(host);

	if (err && cmd->retries && mmc_host_is_spi(host)) {
		if (cmd->resp[0] & R1_SPI_ILLEGAL_COMMAND)
			cmd->retries = 0;
	}

	if (host->ongoing_mrq == mrq)
		host->ongoing_mrq = NULL;

	mmc_complete_cmd(mrq);

	trace_mmc_request_done(host, mrq);

	/*
	 * We list various conditions for the command to be considered
	 * properly done:
	 *
	 * - There was no error, OK fine then
	 * - We are not doing some kind of retry
	 * - The card was removed (...so just complete everything no matter
	 *   if there are errors or retries)
	 */
	if (!err || !cmd->retries || mmc_card_removed(host->card)) {
		mmc_should_fail_request(host, mrq);

		if (!host->ongoing_mrq)
			led_trigger_event(host->led, LED_OFF);

		if (mrq->sbc) {
			pr_debug("%s: req done <CMD%u>: %d: %08x %08x %08x %08x\n",
				mmc_hostname(host), mrq->sbc->opcode,
				mrq->sbc->error,
				mrq->sbc->resp[0], mrq->sbc->resp[1],
				mrq->sbc->resp[2], mrq->sbc->resp[3]);
		}

		pr_debug("%s: req done (CMD%u): %d: %08x %08x %08x %08x\n",
			mmc_hostname(host), cmd->opcode, err,
			cmd->resp[0], cmd->resp[1],
			cmd->resp[2], cmd->resp[3]);

		if (mrq->data) {
			pr_debug("%s:     %d bytes transferred: %d\n",
				mmc_hostname(host),
				mrq->data->bytes_xfered, mrq->data->error);
		}

		if (mrq->stop) {
			pr_debug("%s:     (CMD%u): %d: %08x %08x %08x %08x\n",
				mmc_hostname(host), mrq->stop->opcode,
				mrq->stop->error,
				mrq->stop->resp[0], mrq->stop->resp[1],
				mrq->stop->resp[2], mrq->stop->resp[3]);
		}
	}
	/*
	 * Request starter must handle retries - see
	 * mmc_wait_for_req_done().
	 */
	if (mrq->done)
		mrq->done(mrq);
}

EXPORT_SYMBOL(mmc_request_done);

static void __mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
{
	int err;

	/* Assumes host controller has been runtime resumed by mmc_claim_host */
	err = mmc_retune(host);
	if (err) {
		mrq->cmd->error = err;
		mmc_request_done(host, mrq);
		return;
	}

	/*
	 * For sdio rw commands we must wait for card busy otherwise some
	 * sdio devices won't work properly.
	 * And bypass I/O abort, reset and bus suspend operations.
	 */
	if (sdio_is_io_busy(mrq->cmd->opcode, mrq->cmd->arg) &&
	    host->ops->card_busy) {
		int tries = 500; /* Wait aprox 500ms at maximum */

		while (host->ops->card_busy(host) && --tries)
			mmc_delay(1);

		if (tries == 0) {
			mrq->cmd->error = -EBUSY;
			mmc_request_done(host, mrq);
			return;
		}
	}

	if (mrq->cap_cmd_during_tfr) {
		host->ongoing_mrq = mrq;
		/*
		 * Retry path could come through here without having waiting on
		 * cmd_completion, so ensure it is reinitialised.
		 */
		reinit_completion(&mrq->cmd_completion);
	}

	trace_mmc_request_start(host, mrq);

	if (host->cqe_on)
		host->cqe_ops->cqe_off(host);

	host->ops->request(host, mrq);
}

static void mmc_mrq_pr_debug(struct mmc_host *host, struct mmc_request *mrq,
			     bool cqe)
{
	if (mrq->sbc) {
		pr_debug("<%s: starting CMD%u arg %08x flags %08x>\n",
			 mmc_hostname(host), mrq->sbc->opcode,
			 mrq->sbc->arg, mrq->sbc->flags);
	}

	if (mrq->cmd) {
		pr_debug("%s: starting %sCMD%u arg %08x flags %08x\n",
			 mmc_hostname(host), cqe ? "CQE direct " : "",
			 mrq->cmd->opcode, mrq->cmd->arg, mrq->cmd->flags);
	} else if (cqe) {
		pr_debug("%s: starting CQE transfer for tag %d blkaddr %u\n",
			 mmc_hostname(host), mrq->tag, mrq->data->blk_addr);
	}

	if (mrq->data) {
		pr_debug("%s:     blksz %d blocks %d flags %08x "
			"tsac %d ms nsac %d\n",
			mmc_hostname(host), mrq->data->blksz,
			mrq->data->blocks, mrq->data->flags,
			mrq->data->timeout_ns / 1000000,
			mrq->data->timeout_clks);
	}

	if (mrq->stop) {
		pr_debug("%s:     CMD%u arg %08x flags %08x\n",
			 mmc_hostname(host), mrq->stop->opcode,
			 mrq->stop->arg, mrq->stop->flags);
	}
}

static int mmc_mrq_prep(struct mmc_host *host, struct mmc_request *mrq)
{
	unsigned int i, sz = 0;
	struct scatterlist *sg;

	if (mrq->cmd) {
		mrq->cmd->error = 0;
		mrq->cmd->mrq = mrq;
		mrq->cmd->data = mrq->data;
	}
	if (mrq->sbc) {
		mrq->sbc->error = 0;
		mrq->sbc->mrq = mrq;
	}
	if (mrq->data) {
		if (mrq->data->blksz > host->max_blk_size ||
		    mrq->data->blocks > host->max_blk_count ||
		    mrq->data->blocks * mrq->data->blksz > host->max_req_size)
			return -EINVAL;

		for_each_sg(mrq->data->sg, sg, mrq->data->sg_len, i)
			sz += sg->length;
		if (sz != mrq->data->blocks * mrq->data->blksz)
			return -EINVAL;

		mrq->data->error = 0;
		mrq->data->mrq = mrq;
		if (mrq->stop) {
			mrq->data->stop = mrq->stop;
			mrq->stop->error = 0;
			mrq->stop->mrq = mrq;
		}
	}

	return 0;
}

int mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
{
	int err;

	init_completion(&mrq->cmd_completion);

	mmc_retune_hold(host);

	if (mmc_card_removed(host->card))
		return -ENOMEDIUM;

	mmc_mrq_pr_debug(host, mrq, false);

	WARN_ON(!host->claimed);

	err = mmc_mrq_prep(host, mrq);
	if (err)
		return err;

	led_trigger_event(host->led, LED_FULL);
	__mmc_start_request(host, mrq);

	return 0;
}
EXPORT_SYMBOL(mmc_start_request);

static void mmc_wait_done(struct mmc_request *mrq)
{
	complete(&mrq->completion);
}

static inline void mmc_wait_ongoing_tfr_cmd(struct mmc_host *host)
{
	struct mmc_request *ongoing_mrq = READ_ONCE(host->ongoing_mrq);

	/*
	 * If there is an ongoing transfer, wait for the command line to become
	 * available.
	 */
	if (ongoing_mrq && !completion_done(&ongoing_mrq->cmd_completion))
		wait_for_completion(&ongoing_mrq->cmd_completion);
}

static int __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq)
{
	int err;

	mmc_wait_ongoing_tfr_cmd(host);

	init_completion(&mrq->completion);
	mrq->done = mmc_wait_done;

	err = mmc_start_request(host, mrq);
	if (err) {
		mrq->cmd->error = err;
		mmc_complete_cmd(mrq);
		complete(&mrq->completion);
	}

	return err;
}

void mmc_wait_for_req_done(struct mmc_host *host, struct mmc_request *mrq)
{
	struct mmc_command *cmd;

	while (1) {
		wait_for_completion(&mrq->completion);

		cmd = mrq->cmd;

		if (!cmd->error || !cmd->retries ||
		    mmc_card_removed(host->card))
			break;

		mmc_retune_recheck(host);

		pr_debug("%s: req failed (CMD%u): %d, retrying...\n",
			 mmc_hostname(host), cmd->opcode, cmd->error);
		cmd->retries--;
		cmd->error = 0;
		__mmc_start_request(host, mrq);
	}

	mmc_retune_release(host);
}
EXPORT_SYMBOL(mmc_wait_for_req_done);

/*
 * mmc_cqe_start_req - Start a CQE request.
 * @host: MMC host to start the request
 * @mrq: request to start
 *
 * Start the request, re-tuning if needed and it is possible. Returns an error
 * code if the request fails to start or -EBUSY if CQE is busy.
 */
int mmc_cqe_start_req(struct mmc_host *host, struct mmc_request *mrq)
{
	int err;

	/*
	 * CQE cannot process re-tuning commands. Caller must hold retuning
	 * while CQE is in use.  Re-tuning can happen here only when CQE has no
	 * active requests i.e. this is the first.  Note, re-tuning will call
	 * ->cqe_off().
	 */
	err = mmc_retune(host);
	if (err)
		goto out_err;

	mrq->host = host;

	mmc_mrq_pr_debug(host, mrq, true);

	err = mmc_mrq_prep(host, mrq);
	if (err)
		goto out_err;

	err = host->cqe_ops->cqe_request(host, mrq);
	if (err)
		goto out_err;

	trace_mmc_request_start(host, mrq);

	return 0;

out_err:
	if (mrq->cmd) {
		pr_debug("%s: failed to start CQE direct CMD%u, error %d\n",
			 mmc_hostname(host), mrq->cmd->opcode, err);
	} else {
		pr_debug("%s: failed to start CQE transfer for tag %d, error %d\n",
			 mmc_hostname(host), mrq->tag, err);
	}
	return err;
}
EXPORT_SYMBOL(mmc_cqe_start_req);

/**
 *	mmc_cqe_request_done - CQE has finished processing an MMC request
 *	@host: MMC host which completed request
 *	@mrq: MMC request which completed
 *
 *	CQE drivers should call this function when they have completed
 *	their processing of a request.
 */
void mmc_cqe_request_done(struct mmc_host *host, struct mmc_request *mrq)
{
	mmc_should_fail_request(host, mrq);

	/* Flag re-tuning needed on CRC errors */
	if ((mrq->cmd && mrq->cmd->error == -EILSEQ) ||
	    (mrq->data && mrq->data->error == -EILSEQ))
		mmc_retune_needed(host);

	trace_mmc_request_done(host, mrq);

	if (mrq->cmd) {
		pr_debug("%s: CQE req done (direct CMD%u): %d\n",
			 mmc_hostname(host), mrq->cmd->opcode, mrq->cmd->error);
	} else {
		pr_debug("%s: CQE transfer done tag %d\n",
			 mmc_hostname(host), mrq->tag);
	}

	if (mrq->data) {
		pr_debug("%s:     %d bytes transferred: %d\n",
			 mmc_hostname(host),
			 mrq->data->bytes_xfered, mrq->data->error);
	}

	mrq->done(mrq);
}
EXPORT_SYMBOL(mmc_cqe_request_done);

/**
 *	mmc_cqe_post_req - CQE post process of a completed MMC request
 *	@host: MMC host
 *	@mrq: MMC request to be processed
 */
void mmc_cqe_post_req(struct mmc_host *host, struct mmc_request *mrq)
{
	if (host->cqe_ops->cqe_post_req)
		host->cqe_ops->cqe_post_req(host, mrq);
}
EXPORT_SYMBOL(mmc_cqe_post_req);

/* Arbitrary 1 second timeout */
#define MMC_CQE_RECOVERY_TIMEOUT	1000

/*
 * mmc_cqe_recovery - Recover from CQE errors.
 * @host: MMC host to recover
 *
 * Recovery consists of stopping CQE, stopping eMMC, discarding the queue
 * in eMMC, and discarding the queue in CQE. CQE must call
 * mmc_cqe_request_done() on all requests. An error is returned if the eMMC
 * fails to discard its queue.
 */
int mmc_cqe_recovery(struct mmc_host *host)
{
	struct mmc_command cmd;
	int err;

	mmc_retune_hold_now(host);

	/*
	 * Recovery is expected seldom, if at all, but it reduces performance,
	 * so make sure it is not completely silent.
	 */
	pr_warn("%s: running CQE recovery\n", mmc_hostname(host));

	host->cqe_ops->cqe_recovery_start(host);

	memset(&cmd, 0, sizeof(cmd));
	cmd.opcode       = MMC_STOP_TRANSMISSION;
	cmd.flags        = MMC_RSP_R1B | MMC_CMD_AC;
	cmd.flags       &= ~MMC_RSP_CRC; /* Ignore CRC */
	cmd.busy_timeout = MMC_CQE_RECOVERY_TIMEOUT;
	mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);

	mmc_poll_for_busy(host->card, MMC_CQE_RECOVERY_TIMEOUT, true, MMC_BUSY_IO);

	memset(&cmd, 0, sizeof(cmd));
	cmd.opcode       = MMC_CMDQ_TASK_MGMT;
	cmd.arg          = 1; /* Discard entire queue */
	cmd.flags        = MMC_RSP_R1B | MMC_CMD_AC;
	cmd.flags       &= ~MMC_RSP_CRC; /* Ignore CRC */
	cmd.busy_timeout = MMC_CQE_RECOVERY_TIMEOUT;
	err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);

	host->cqe_ops->cqe_recovery_finish(host);

	if (err)
		err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);

	mmc_retune_release(host);

	return err;
}
EXPORT_SYMBOL(mmc_cqe_recovery);

/**
 *	mmc_is_req_done - Determine if a 'cap_cmd_during_tfr' request is done
 *	@host: MMC host
 *	@mrq: MMC request
 *
 *	mmc_is_req_done() is used with requests that have
 *	mrq->cap_cmd_during_tfr = true. mmc_is_req_done() must be called after
 *	starting a request and before waiting for it to complete. That is,
 *	either in between calls to mmc_start_req(), or after mmc_wait_for_req()
 *	and before mmc_wait_for_req_done(). If it is called at other times the
 *	result is not meaningful.
 */
bool mmc_is_req_done(struct mmc_host *host, struct mmc_request *mrq)
{
	return completion_done(&mrq->completion);
}
EXPORT_SYMBOL(mmc_is_req_done);

/**
 *	mmc_wait_for_req - start a request and wait for completion
 *	@host: MMC host to start command
 *	@mrq: MMC request to start
 *
 *	Start a new MMC custom command request for a host, and wait
 *	for the command to complete. In the case of 'cap_cmd_during_tfr'
 *	requests, the transfer is ongoing and the caller can issue further
 *	commands that do not use the data lines, and then wait by calling
 *	mmc_wait_for_req_done().
 *	Does not attempt to parse the response.
 */
void mmc_wait_for_req(struct mmc_host *host, struct mmc_request *mrq)
{
	__mmc_start_req(host, mrq);

	if (!mrq->cap_cmd_during_tfr)
		mmc_wait_for_req_done(host, mrq);
}
EXPORT_SYMBOL(mmc_wait_for_req);

/**
 *	mmc_wait_for_cmd - start a command and wait for completion
 *	@host: MMC host to start command
 *	@cmd: MMC command to start
 *	@retries: maximum number of retries
 *
 *	Start a new MMC command for a host, and wait for the command
 *	to complete.  Return any error that occurred while the command
 *	was executing.  Do not attempt to parse the response.
 */
int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd, int retries)
{
	struct mmc_request mrq = {};

	WARN_ON(!host->claimed);

	memset(cmd->resp, 0, sizeof(cmd->resp));
	cmd->retries = retries;

	mrq.cmd = cmd;
	cmd->data = NULL;

	mmc_wait_for_req(host, &mrq);

	return cmd->error;
}

EXPORT_SYMBOL(mmc_wait_for_cmd);

/**
 *	mmc_set_data_timeout - set the timeout for a data command
 *	@data: data phase for command
 *	@card: the MMC card associated with the data transfer
 *
 *	Computes the data timeout parameters according to the
 *	correct algorithm given the card type.
 */
void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card)
{
	unsigned int mult;

	/*
	 * SDIO cards only define an upper 1 s limit on access.
	 */
	if (mmc_card_sdio(card)) {
		data->timeout_ns = 1000000000;
		data->timeout_clks = 0;
		return;
	}

	/*
	 * SD cards use a 100 multiplier rather than 10
	 */
	mult = mmc_card_sd(card) ? 100 : 10;

	/*
	 * Scale up the multiplier (and therefore the timeout) by
	 * the r2w factor for writes.
	 */
	if (data->flags & MMC_DATA_WRITE)
		mult <<= card->csd.r2w_factor;

	data->timeout_ns = card->csd.taac_ns * mult;
	data->timeout_clks = card->csd.taac_clks * mult;

	/*
	 * SD cards also have an upper limit on the timeout.
	 */
	if (mmc_card_sd(card)) {
		unsigned int timeout_us, limit_us;

		timeout_us = data->timeout_ns / 1000;
		if (card->host->ios.clock)
			timeout_us += data->timeout_clks * 1000 /
				(card->host->ios.clock / 1000);

		if (data->flags & MMC_DATA_WRITE)
			/*
			 * The MMC spec "It is strongly recommended
			 * for hosts to implement more than 500ms
			 * timeout value even if the card indicates
			 * the 250ms maximum busy length."  Even the
			 * previous value of 300ms is known to be
			 * insufficient for some cards.
			 */
			limit_us = 3000000;
		else
			limit_us = 100000;

		/*
		 * SDHC cards always use these fixed values.
		 */
		if (timeout_us > limit_us) {
			data->timeout_ns = limit_us * 1000;
			data->timeout_clks = 0;
		}

		/* assign limit value if invalid */
		if (timeout_us == 0)
			data->timeout_ns = limit_us * 1000;
	}

	/*
	 * Some cards require longer data read timeout than indicated in CSD.
	 * Address this by setting the read timeout to a "reasonably high"
	 * value. For the cards tested, 600ms has proven enough. If necessary,
	 * this value can be increased if other problematic cards require this.
	 */
	if (mmc_card_long_read_time(card) && data->flags & MMC_DATA_READ) {
		data->timeout_ns = 600000000;
		data->timeout_clks = 0;
	}

	/*
	 * Some cards need very high timeouts if driven in SPI mode.
	 * The worst observed timeout was 900ms after writing a
	 * continuous stream of data until the internal logic
	 * overflowed.
	 */
	if (mmc_host_is_spi(card->host)) {
		if (data->flags & MMC_DATA_WRITE) {
			if (data->timeout_ns < 1000000000)
				data->timeout_ns = 1000000000;	/* 1s */
		} else {
			if (data->timeout_ns < 100000000)
				data->timeout_ns =  100000000;	/* 100ms */
		}
	}
}
EXPORT_SYMBOL(mmc_set_data_timeout);

/*
 * Allow claiming an already claimed host if the context is the same or there is
 * no context but the task is the same.
 */
static inline bool mmc_ctx_matches(struct mmc_host *host, struct mmc_ctx *ctx,
				   struct task_struct *task)
{
	return host->claimer == ctx ||
	       (!ctx && task && host->claimer->task == task);
}

static inline void mmc_ctx_set_claimer(struct mmc_host *host,
				       struct mmc_ctx *ctx,
				       struct task_struct *task)
{
	if (!host->claimer) {
		if (ctx)
			host->claimer = ctx;
		else
			host->claimer = &host->default_ctx;
	}
	if (task)
		host->claimer->task = task;
}

/**
 *	__mmc_claim_host - exclusively claim a host
 *	@host: mmc host to claim
 *	@ctx: context that claims the host or NULL in which case the default
 *	context will be used
 *	@abort: whether or not the operation should be aborted
 *
 *	Claim a host for a set of operations.  If @abort is non null and
 *	dereference a non-zero value then this will return prematurely with
 *	that non-zero value without acquiring the lock.  Returns zero
 *	with the lock held otherwise.
 */
int __mmc_claim_host(struct mmc_host *host, struct mmc_ctx *ctx,
		     atomic_t *abort)
{
	struct task_struct *task = ctx ? NULL : current;
	DECLARE_WAITQUEUE(wait, current);
	unsigned long flags;
	int stop;
	bool pm = false;

	might_sleep();

	add_wait_queue(&host->wq, &wait);
	spin_lock_irqsave(&host->lock, flags);
	while (1) {
		set_current_state(TASK_UNINTERRUPTIBLE);
		stop = abort ? atomic_read(abort) : 0;
		if (stop || !host->claimed || mmc_ctx_matches(host, ctx, task))
			break;
		spin_unlock_irqrestore(&host->lock, flags);
		schedule();
		spin_lock_irqsave(&host->lock, flags);
	}
	set_current_state(TASK_RUNNING);
	if (!stop) {
		host->claimed = 1;
		mmc_ctx_set_claimer(host, ctx, task);
		host->claim_cnt += 1;
		if (host->claim_cnt == 1)
			pm = true;
	} else
		wake_up(&host->wq);
	spin_unlock_irqrestore(&host->lock, flags);
	remove_wait_queue(&host->wq, &wait);

	if (pm)
		pm_runtime_get_sync(mmc_dev(host));

	return stop;
}
EXPORT_SYMBOL(__mmc_claim_host);

/**
 *	mmc_release_host - release a host
 *	@host: mmc host to release
 *
 *	Release a MMC host, allowing others to claim the host
 *	for their operations.
 */
void mmc_release_host(struct mmc_host *host)
{
	unsigned long flags;

	WARN_ON(!host->claimed);

	spin_lock_irqsave(&host->lock, flags);
	if (--host->claim_cnt) {
		/* Release for nested claim */
		spin_unlock_irqrestore(&host->lock, flags);
	} else {
		host->claimed = 0;
		host->claimer->task = NULL;
		host->claimer = NULL;
		spin_unlock_irqrestore(&host->lock, flags);
		wake_up(&host->wq);
		pm_runtime_mark_last_busy(mmc_dev(host));
		if (host->caps & MMC_CAP_SYNC_RUNTIME_PM)
			pm_runtime_put_sync_suspend(mmc_dev(host));
		else
			pm_runtime_put_autosuspend(mmc_dev(host));
	}
}
EXPORT_SYMBOL(mmc_release_host);

/*
 * This is a helper function, which fetches a runtime pm reference for the
 * card device and also claims the host.
 */
void mmc_get_card(struct mmc_card *card, struct mmc_ctx *ctx)
{
	pm_runtime_get_sync(&card->dev);
	__mmc_claim_host(card->host, ctx, NULL);
}
EXPORT_SYMBOL(mmc_get_card);

/*
 * This is a helper function, which releases the host and drops the runtime
 * pm reference for the card device.
 */
void mmc_put_card(struct mmc_card *card, struct mmc_ctx *ctx)
{
	struct mmc_host *host = card->host;

	WARN_ON(ctx && host->claimer != ctx);

	mmc_release_host(host);
	pm_runtime_mark_last_busy(&card->dev);
	pm_runtime_put_autosuspend(&card->dev);
}
EXPORT_SYMBOL(mmc_put_card);

/*
 * Internal function that does the actual ios call to the host driver,
 * optionally printing some debug output.
 */
static inline void mmc_set_ios(struct mmc_host *host)
{
	struct mmc_ios *ios = &host->ios;

	pr_debug("%s: clock %uHz busmode %u powermode %u cs %u Vdd %u "
		"width %u timing %u\n",
		 mmc_hostname(host), ios->clock, ios->bus_mode,
		 ios->power_mode, ios->chip_select, ios->vdd,
		 1 << ios->bus_width, ios->timing);

	host->ops->set_ios(host, ios);
}

/*
 * Control chip select pin on a host.
 */
void mmc_set_chip_select(struct mmc_host *host, int mode)
{
	host->ios.chip_select = mode;
	mmc_set_ios(host);
}

/*
 * Sets the host clock to the highest possible frequency that
 * is below "hz".
 */
void mmc_set_clock(struct mmc_host *host, unsigned int hz)
{
	WARN_ON(hz && hz < host->f_min);

	if (hz > host->f_max)
		hz = host->f_max;

	host->ios.clock = hz;
	mmc_set_ios(host);
}

int mmc_execute_tuning(struct mmc_card *card)
{
	struct mmc_host *host = card->host;
	u32 opcode;
	int err;

	if (!host->ops->execute_tuning)
		return 0;

	if (host->cqe_on)
		host->cqe_ops->cqe_off(host);

	if (mmc_card_mmc(card))
		opcode = MMC_SEND_TUNING_BLOCK_HS200;
	else
		opcode = MMC_SEND_TUNING_BLOCK;

	err = host->ops->execute_tuning(host, opcode);
	if (!err) {
		mmc_retune_clear(host);
		mmc_retune_enable(host);
		return 0;
	}

	/* Only print error when we don't check for card removal */
	if (!host->detect_change) {
		pr_err("%s: tuning execution failed: %d\n",
			mmc_hostname(host), err);
		mmc_debugfs_err_stats_inc(host, MMC_ERR_TUNING);
	}

	return err;
}

/*
 * Change the bus mode (open drain/push-pull) of a host.
 */
void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode)
{
	host->ios.bus_mode = mode;
	mmc_set_ios(host);
}

/*
 * Change data bus width of a host.
 */
void mmc_set_bus_width(struct mmc_host *host, unsigned int width)
{
	host->ios.bus_width = width;
	mmc_set_ios(host);
}

/*
 * Set initial state after a power cycle or a hw_reset.
 */
void mmc_set_initial_state(struct mmc_host *host)
{
	if (host->cqe_on)
		host->cqe_ops->cqe_off(host);

	mmc_retune_disable(host);

	if (mmc_host_is_spi(host))
		host->ios.chip_select = MMC_CS_HIGH;
	else
		host->ios.chip_select = MMC_CS_DONTCARE;
	host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;
	host->ios.bus_width = MMC_BUS_WIDTH_1;
	host->ios.timing = MMC_TIMING_LEGACY;
	host->ios.drv_type = 0;
	host->ios.enhanced_strobe = false;

	/*
	 * Make sure we are in non-enhanced strobe mode before we
	 * actually enable it in ext_csd.
	 */
	if ((host->caps2 & MMC_CAP2_HS400_ES) &&
	     host->ops->hs400_enhanced_strobe)
		host->ops->hs400_enhanced_strobe(host, &host->ios);

	mmc_set_ios(host);

	mmc_crypto_set_initial_state(host);
}

/**
 * mmc_vdd_to_ocrbitnum - Convert a voltage to the OCR bit number
 * @vdd:	voltage (mV)
 * @low_bits:	prefer low bits in boundary cases
 *
 * This function returns the OCR bit number according to the provided @vdd
 * value. If conversion is not possible a negative errno value returned.
 *
 * Depending on the @low_bits flag the function prefers low or high OCR bits
 * on boundary voltages. For example,
 * with @low_bits = true, 3300 mV translates to ilog2(MMC_VDD_32_33);
 * with @low_bits = false, 3300 mV translates to ilog2(MMC_VDD_33_34);
 *
 * Any value in the [1951:1999] range translates to the ilog2(MMC_VDD_20_21).
 */
static int mmc_vdd_to_ocrbitnum(int vdd, bool low_bits)
{
	const int max_bit = ilog2(MMC_VDD_35_36);
	int bit;

	if (vdd < 1650 || vdd > 3600)
		return -EINVAL;

	if (vdd >= 1650 && vdd <= 1950)
		return ilog2(MMC_VDD_165_195);

	if (low_bits)
		vdd -= 1;

	/* Base 2000 mV, step 100 mV, bit's base 8. */
	bit = (vdd - 2000) / 100 + 8;
	if (bit > max_bit)
		return max_bit;
	return bit;
}

/**
 * mmc_vddrange_to_ocrmask - Convert a voltage range to the OCR mask
 * @vdd_min:	minimum voltage value (mV)
 * @vdd_max:	maximum voltage value (mV)
 *
 * This function returns the OCR mask bits according to the provided @vdd_min
 * and @vdd_max values. If conversion is not possible the function returns 0.
 *
 * Notes wrt boundary cases:
 * This function sets the OCR bits for all boundary voltages, for example
 * [3300:3400] range is translated to MMC_VDD_32_33 | MMC_VDD_33_34 |
 * MMC_VDD_34_35 mask.
 */
u32 mmc_vddrange_to_ocrmask(int vdd_min, int vdd_max)
{
	u32 mask = 0;

	if (vdd_max < vdd_min)
		return 0;

	/* Prefer high bits for the boundary vdd_max values. */
	vdd_max = mmc_vdd_to_ocrbitnum(vdd_max, false);
	if (vdd_max < 0)
		return 0;

	/* Prefer low bits for the boundary vdd_min values. */
	vdd_min = mmc_vdd_to_ocrbitnum(vdd_min, true);
	if (vdd_min < 0)
		return 0;

	/* Fill the mask, from max bit to min bit. */
	while (vdd_max >= vdd_min)
		mask |= 1 << vdd_max--;

	return mask;
}

static int mmc_of_get_func_num(struct device_node *node)
{
	u32 reg;
	int ret;

	ret = of_property_read_u32(node, "reg", &reg);
	if (ret < 0)
		return ret;

	return reg;
}

struct device_node *mmc_of_find_child_device(struct mmc_host *host,
		unsigned func_num)
{
	struct device_node *node;

	if (!host->parent || !host->parent->of_node)
		return NULL;

	for_each_child_of_node(host->parent->of_node, node) {
		if (mmc_of_get_func_num(node) == func_num)
			return node;
	}

	return NULL;
}

/*
 * Mask off any voltages we don't support and select
 * the lowest voltage
 */
u32 mmc_select_voltage(struct mmc_host *host, u32 ocr)
{
	int bit;

	/*
	 * Sanity check the voltages that the card claims to
	 * support.
	 */
	if (ocr & 0x7F) {
		dev_warn(mmc_dev(host),
		"card claims to support voltages below defined range\n");
		ocr &= ~0x7F;
	}

	ocr &= host->ocr_avail;
	if (!ocr) {
		dev_warn(mmc_dev(host), "no support for card's volts\n");
		return 0;
	}

	if (host->caps2 & MMC_CAP2_FULL_PWR_CYCLE) {
		bit = ffs(ocr) - 1;
		ocr &= 3 << bit;
		mmc_power_cycle(host, ocr);
	} else {
		bit = fls(ocr) - 1;
		/*
		 * The bit variable represents the highest voltage bit set in
		 * the OCR register.
		 * To keep a range of 2 values (e.g. 3.2V/3.3V and 3.3V/3.4V),
		 * we must shift the mask '3' with (bit - 1).
		 */
		ocr &= 3 << (bit - 1);
		if (bit != host->ios.vdd)
			dev_warn(mmc_dev(host), "exceeding card's volts\n");
	}

	return ocr;
}

int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage)
{
	int err = 0;
	int old_signal_voltage = host->ios.signal_voltage;

	host->ios.signal_voltage = signal_voltage;
	if (host->ops->start_signal_voltage_switch)
		err = host->ops->start_signal_voltage_switch(host, &host->ios);

	if (err)
		host->ios.signal_voltage = old_signal_voltage;

	return err;

}

void mmc_set_initial_signal_voltage(struct mmc_host *host)
{
	/* Try to set signal voltage to 3.3V but fall back to 1.8v or 1.2v */
	if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330))
		dev_dbg(mmc_dev(host), "Initial signal voltage of 3.3v\n");
	else if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180))
		dev_dbg(mmc_dev(host), "Initial signal voltage of 1.8v\n");
	else if (!mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120))
		dev_dbg(mmc_dev(host), "Initial signal voltage of 1.2v\n");
}

int mmc_host_set_uhs_voltage(struct mmc_host *host)
{
	u32 clock;

	/*
	 * During a signal voltage level switch, the clock must be gated
	 * for 5 ms according to the SD spec
	 */
	clock = host->ios.clock;
	host->ios.clock = 0;
	mmc_set_ios(host);

	if (mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180))
		return -EAGAIN;

	/* Keep clock gated for at least 10 ms, though spec only says 5 ms */
	mmc_delay(10);
	host->ios.clock = clock;
	mmc_set_ios(host);

	return 0;
}

int mmc_set_uhs_voltage(struct mmc_host *host, u32 ocr)
{
	struct mmc_command cmd = {};
	int err = 0;

	/*
	 * If we cannot switch voltages, return failure so the caller
	 * can continue without UHS mode
	 */
	if (!host->ops->start_signal_voltage_switch)
		return -EPERM;
	if (!host->ops->card_busy)
		pr_warn("%s: cannot verify signal voltage switch\n",
			mmc_hostname(host));

	cmd.opcode = SD_SWITCH_VOLTAGE;
	cmd.arg = 0;
	cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;

	err = mmc_wait_for_cmd(host, &cmd, 0);
	if (err)
		goto power_cycle;

	if (!mmc_host_is_spi(host) && (cmd.resp[0] & R1_ERROR))
		return -EIO;

	/*
	 * The card should drive cmd and dat[0:3] low immediately
	 * after the response of cmd11, but wait 1 ms to be sure
	 */
	mmc_delay(1);
	if (host->ops->card_busy && !host->ops->card_busy(host)) {
		err = -EAGAIN;
		goto power_cycle;
	}

	if (mmc_host_set_uhs_voltage(host)) {
		/*
		 * Voltages may not have been switched, but we've already
		 * sent CMD11, so a power cycle is required anyway
		 */
		err = -EAGAIN;
		goto power_cycle;
	}

	/* Wait for at least 1 ms according to spec */
	mmc_delay(1);

	/*
	 * Failure to switch is indicated by the card holding
	 * dat[0:3] low
	 */
	if (host->ops->card_busy && host->ops->card_busy(host))
		err = -EAGAIN;

power_cycle:
	if (err) {
		pr_debug("%s: Signal voltage switch failed, "
			"power cycling card\n", mmc_hostname(host));
		mmc_power_cycle(host, ocr);
	}

	return err;
}

/*
 * Select timing parameters for host.
 */
void mmc_set_timing(struct mmc_host *host, unsigned int timing)
{
	host->ios.timing = timing;
	mmc_set_ios(host);
}

/*
 * Select appropriate driver type for host.
 */
void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type)
{
	host->ios.drv_type = drv_type;
	mmc_set_ios(host);
}

int mmc_select_drive_strength(struct mmc_card *card, unsigned int max_dtr,
			      int card_drv_type, int *drv_type)
{
	struct mmc_host *host = card->host;
	int host_drv_type = SD_DRIVER_TYPE_B;

	*drv_type = 0;

	if (!host->ops->select_drive_strength)
		return 0;

	/* Use SD definition of driver strength for hosts */
	if (host->caps & MMC_CAP_DRIVER_TYPE_A)
		host_drv_type |= SD_DRIVER_TYPE_A;

	if (host->caps & MMC_CAP_DRIVER_TYPE_C)
		host_drv_type |= SD_DRIVER_TYPE_C;

	if (host->caps & MMC_CAP_DRIVER_TYPE_D)
		host_drv_type |= SD_DRIVER_TYPE_D;

	/*
	 * The drive strength that the hardware can support
	 * depends on the board design.  Pass the appropriate
	 * information and let the hardware specific code
	 * return what is possible given the options
	 */
	return host->ops->select_drive_strength(card, max_dtr,
						host_drv_type,
						card_drv_type,
						drv_type);
}

/*
 * Apply power to the MMC stack.  This is a two-stage process.
 * First, we enable power to the card without the clock running.
 * We then wait a bit for the power to stabilise.  Finally,
 * enable the bus drivers and clock to the card.
 *
 * We must _NOT_ enable the clock prior to power stablising.
 *
 * If a host does all the power sequencing itself, ignore the
 * initial MMC_POWER_UP stage.
 */
void mmc_power_up(struct mmc_host *host, u32 ocr)
{
	if (host->ios.power_mode == MMC_POWER_ON)
		return;

	mmc_pwrseq_pre_power_on(host);

	host->ios.vdd = fls(ocr) - 1;
	host->ios.power_mode = MMC_POWER_UP;
	/* Set initial state and call mmc_set_ios */
	mmc_set_initial_state(host);

	mmc_set_initial_signal_voltage(host);

	/*
	 * This delay should be sufficient to allow the power supply
	 * to reach the minimum voltage.
	 */
	mmc_delay(host->ios.power_delay_ms);

	mmc_pwrseq_post_power_on(host);

	host->ios.clock = host->f_init;

	host->ios.power_mode = MMC_POWER_ON;
	mmc_set_ios(host);

	/*
	 * This delay must be at least 74 clock sizes, or 1 ms, or the
	 * time required to reach a stable voltage.
	 */
	mmc_delay(host->ios.power_delay_ms);
}

void mmc_power_off(struct mmc_host *host)
{
	if (host->ios.power_mode == MMC_POWER_OFF)
		return;

	mmc_pwrseq_power_off(host);

	host->ios.clock = 0;
	host->ios.vdd = 0;

	host->ios.power_mode = MMC_POWER_OFF;
	/* Set initial state and call mmc_set_ios */
	mmc_set_initial_state(host);

	/*
	 * Some configurations, such as the 802.11 SDIO card in the OLPC
	 * XO-1.5, require a short delay after poweroff before the card
	 * can be successfully turned on again.
	 */
	mmc_delay(1);
}

void mmc_power_cycle(struct mmc_host *host, u32 ocr)
{
	mmc_power_off(host);
	/* Wait at least 1 ms according to SD spec */
	mmc_delay(1);
	mmc_power_up(host, ocr);
}

/*
 * Assign a mmc bus handler to a host. Only one bus handler may control a
 * host at any given time.
 */
void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops)
{
	host->bus_ops = ops;
}

/*
 * Remove the current bus handler from a host.
 */
void mmc_detach_bus(struct mmc_host *host)
{
	host->bus_ops = NULL;
}

void _mmc_detect_change(struct mmc_host *host, unsigned long delay, bool cd_irq)
{
	/*
	 * Prevent system sleep for 5s to allow user space to consume the
	 * corresponding uevent. This is especially useful, when CD irq is used
	 * as a system wakeup, but doesn't hurt in other cases.
	 */
	if (cd_irq && !(host->caps & MMC_CAP_NEEDS_POLL))
		__pm_wakeup_event(host->ws, 5000);

	host->detect_change = 1;
	mmc_schedule_delayed_work(&host->detect, delay);
}

/**
 *	mmc_detect_change - process change of state on a MMC socket
 *	@host: host which changed state.
 *	@delay: optional delay to wait before detection (jiffies)
 *
 *	MMC drivers should call this when they detect a card has been
 *	inserted or removed. The MMC layer will confirm that any
 *	present card is still functional, and initialize any newly
 *	inserted.
 */
void mmc_detect_change(struct mmc_host *host, unsigned long delay)
{
	_mmc_detect_change(host, delay, true);
}
EXPORT_SYMBOL(mmc_detect_change);

void mmc_init_erase(struct mmc_card *card)
{
	unsigned int sz;

	if (is_power_of_2(card->erase_size))
		card->erase_shift = ffs(card->erase_size) - 1;
	else
		card->erase_shift = 0;

	/*
	 * It is possible to erase an arbitrarily large area of an SD or MMC
	 * card.  That is not desirable because it can take a long time
	 * (minutes) potentially delaying more important I/O, and also the
	 * timeout calculations become increasingly hugely over-estimated.
	 * Consequently, 'pref_erase' is defined as a guide to limit erases
	 * to that size and alignment.
	 *
	 * For SD cards that define Allocation Unit size, limit erases to one
	 * Allocation Unit at a time.
	 * For MMC, have a stab at ai good value and for modern cards it will
	 * end up being 4MiB. Note that if the value is too small, it can end
	 * up taking longer to erase. Also note, erase_size is already set to
	 * High Capacity Erase Size if available when this function is called.
	 */
	if (mmc_card_sd(card) && card->ssr.au) {
		card->pref_erase = card->ssr.au;
		card->erase_shift = ffs(card->ssr.au) - 1;
	} else if (card->erase_size) {
		sz = (card->csd.capacity << (card->csd.read_blkbits - 9)) >> 11;
		if (sz < 128)
			card->pref_erase = 512 * 1024 / 512;
		else if (sz < 512)
			card->pref_erase = 1024 * 1024 / 512;
		else if (sz < 1024)
			card->pref_erase = 2 * 1024 * 1024 / 512;
		else
			card->pref_erase = 4 * 1024 * 1024 / 512;
		if (card->pref_erase < card->erase_size)
			card->pref_erase = card->erase_size;
		else {
			sz = card->pref_erase % card->erase_size;
			if (sz)
				card->pref_erase += card->erase_size - sz;
		}
	} else
		card->pref_erase = 0;
}

static bool is_trim_arg(unsigned int arg)
{
	return (arg & MMC_TRIM_OR_DISCARD_ARGS) && arg != MMC_DISCARD_ARG;
}

static unsigned int mmc_mmc_erase_timeout(struct mmc_card *card,
				          unsigned int arg, unsigned int qty)
{
	unsigned int erase_timeout;

	if (arg == MMC_DISCARD_ARG ||
	    (arg == MMC_TRIM_ARG && card->ext_csd.rev >= 6)) {
		erase_timeout = card->ext_csd.trim_timeout;
	} else if (card->ext_csd.erase_group_def & 1) {
		/* High Capacity Erase Group Size uses HC timeouts */
		if (arg == MMC_TRIM_ARG)
			erase_timeout = card->ext_csd.trim_timeout;
		else
			erase_timeout = card->ext_csd.hc_erase_timeout;
	} else {
		/* CSD Erase Group Size uses write timeout */
		unsigned int mult = (10 << card->csd.r2w_factor);
		unsigned int timeout_clks = card->csd.taac_clks * mult;
		unsigned int timeout_us;

		/* Avoid overflow: e.g. taac_ns=80000000 mult=1280 */
		if (card->csd.taac_ns < 1000000)
			timeout_us = (card->csd.taac_ns * mult) / 1000;
		else
			timeout_us = (card->csd.taac_ns / 1000) * mult;

		/*
		 * ios.clock is only a target.  The real clock rate might be
		 * less but not that much less, so fudge it by multiplying by 2.
		 */
		timeout_clks <<= 1;
		timeout_us += (timeout_clks * 1000) /
			      (card->host->ios.clock / 1000);

		erase_timeout = timeout_us / 1000;

		/*
		 * Theoretically, the calculation could underflow so round up
		 * to 1ms in that case.
		 */
		if (!erase_timeout)
			erase_timeout = 1;
	}

	/* Multiplier for secure operations */
	if (arg & MMC_SECURE_ARGS) {
		if (arg == MMC_SECURE_ERASE_ARG)
			erase_timeout *= card->ext_csd.sec_erase_mult;
		else
			erase_timeout *= card->ext_csd.sec_trim_mult;
	}

	erase_timeout *= qty;

	/*
	 * Ensure at least a 1 second timeout for SPI as per
	 * 'mmc_set_data_timeout()'
	 */
	if (mmc_host_is_spi(card->host) && erase_timeout < 1000)
		erase_timeout = 1000;

	return erase_timeout;
}

static unsigned int mmc_sd_erase_timeout(struct mmc_card *card,
					 unsigned int arg,
					 unsigned int qty)
{
	unsigned int erase_timeout;

	/* for DISCARD none of the below calculation applies.
	 * the busy timeout is 250msec per discard command.
	 */
	if (arg == SD_DISCARD_ARG)
		return SD_DISCARD_TIMEOUT_MS;

	if (card->ssr.erase_timeout) {
		/* Erase timeout specified in SD Status Register (SSR) */
		erase_timeout = card->ssr.erase_timeout * qty +
				card->ssr.erase_offset;
	} else {
		/*
		 * Erase timeout not specified in SD Status Register (SSR) so
		 * use 250ms per write block.
		 */
		erase_timeout = 250 * qty;
	}

	/* Must not be less than 1 second */
	if (erase_timeout < 1000)
		erase_timeout = 1000;

	return erase_timeout;
}

static unsigned int mmc_erase_timeout(struct mmc_card *card,
				      unsigned int arg,
				      unsigned int qty)
{
	if (mmc_card_sd(card))
		return mmc_sd_erase_timeout(card, arg, qty);
	else
		return mmc_mmc_erase_timeout(card, arg, qty);
}

static int mmc_do_erase(struct mmc_card *card, unsigned int from,
			unsigned int to, unsigned int arg)
{
	struct mmc_command cmd = {};
	unsigned int qty = 0, busy_timeout = 0;
	bool use_r1b_resp;
	int err;

	mmc_retune_hold(card->host);

	/*
	 * qty is used to calculate the erase timeout which depends on how many
	 * erase groups (or allocation units in SD terminology) are affected.
	 * We count erasing part of an erase group as one erase group.
	 * For SD, the allocation units are always a power of 2.  For MMC, the
	 * erase group size is almost certainly also power of 2, but it does not
	 * seem to insist on that in the JEDEC standard, so we fall back to
	 * division in that case.  SD may not specify an allocation unit size,
	 * in which case the timeout is based on the number of write blocks.
	 *
	 * Note that the timeout for secure trim 2 will only be correct if the
	 * number of erase groups specified is the same as the total of all
	 * preceding secure trim 1 commands.  Since the power may have been
	 * lost since the secure trim 1 commands occurred, it is generally
	 * impossible to calculate the secure trim 2 timeout correctly.
	 */
	if (card->erase_shift)
		qty += ((to >> card->erase_shift) -
			(from >> card->erase_shift)) + 1;
	else if (mmc_card_sd(card))
		qty += to - from + 1;
	else
		qty += ((to / card->erase_size) -
			(from / card->erase_size)) + 1;

	if (!mmc_card_blockaddr(card)) {
		from <<= 9;
		to <<= 9;
	}

	if (mmc_card_sd(card))
		cmd.opcode = SD_ERASE_WR_BLK_START;
	else
		cmd.opcode = MMC_ERASE_GROUP_START;
	cmd.arg = from;
	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
	err = mmc_wait_for_cmd(card->host, &cmd, 0);
	if (err) {
		pr_err("mmc_erase: group start error %d, "
		       "status %#x\n", err, cmd.resp[0]);
		err = -EIO;
		goto out;
	}

	memset(&cmd, 0, sizeof(struct mmc_command));
	if (mmc_card_sd(card))
		cmd.opcode = SD_ERASE_WR_BLK_END;
	else
		cmd.opcode = MMC_ERASE_GROUP_END;
	cmd.arg = to;
	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
	err = mmc_wait_for_cmd(card->host, &cmd, 0);
	if (err) {
		pr_err("mmc_erase: group end error %d, status %#x\n",
		       err, cmd.resp[0]);
		err = -EIO;
		goto out;
	}

	memset(&cmd, 0, sizeof(struct mmc_command));
	cmd.opcode = MMC_ERASE;
	cmd.arg = arg;
	busy_timeout = mmc_erase_timeout(card, arg, qty);
	use_r1b_resp = mmc_prepare_busy_cmd(card->host, &cmd, busy_timeout);

	err = mmc_wait_for_cmd(card->host, &cmd, 0);
	if (err) {
		pr_err("mmc_erase: erase error %d, status %#x\n",
		       err, cmd.resp[0]);
		err = -EIO;
		goto out;
	}

	if (mmc_host_is_spi(card->host))
		goto out;

	/*
	 * In case of when R1B + MMC_CAP_WAIT_WHILE_BUSY is used, the polling
	 * shall be avoided.
	 */
	if ((card->host->caps & MMC_CAP_WAIT_WHILE_BUSY) && use_r1b_resp)
		goto out;

	/* Let's poll to find out when the erase operation completes. */
	err = mmc_poll_for_busy(card, busy_timeout, false, MMC_BUSY_ERASE);

out:
	mmc_retune_release(card->host);
	return err;
}

static unsigned int mmc_align_erase_size(struct mmc_card *card,
					 unsigned int *from,
					 unsigned int *to,
					 unsigned int nr)
{
	unsigned int from_new = *from, nr_new = nr, rem;

	/*
	 * When the 'card->erase_size' is power of 2, we can use round_up/down()
	 * to align the erase size efficiently.
	 */
	if (is_power_of_2(card->erase_size)) {
		unsigned int temp = from_new;

		from_new = round_up(temp, card->erase_size);
		rem = from_new - temp;

		if (nr_new > rem)
			nr_new -= rem;
		else
			return 0;

		nr_new = round_down(nr_new, card->erase_size);
	} else {
		rem = from_new % card->erase_size;
		if (rem) {
			rem = card->erase_size - rem;
			from_new += rem;
			if (nr_new > rem)
				nr_new -= rem;
			else
				return 0;
		}

		rem = nr_new % card->erase_size;
		if (rem)
			nr_new -= rem;
	}

	if (nr_new == 0)
		return 0;

	*to = from_new + nr_new;
	*from = from_new;

	return nr_new;
}

/**
 * mmc_erase - erase sectors.
 * @card: card to erase
 * @from: first sector to erase
 * @nr: number of sectors to erase
 * @arg: erase command argument
 *
 * Caller must claim host before calling this function.
 */
int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
	      unsigned int arg)
{
	unsigned int rem, to = from + nr;
	int err;

	if (!(card->csd.cmdclass & CCC_ERASE))
		return -EOPNOTSUPP;

	if (!card->erase_size)
		return -EOPNOTSUPP;

	if (mmc_card_sd(card) && arg != SD_ERASE_ARG && arg != SD_DISCARD_ARG)
		return -EOPNOTSUPP;

	if (mmc_card_mmc(card) && (arg & MMC_SECURE_ARGS) &&
	    !(card->ext_csd.sec_feature_support & EXT_CSD_SEC_ER_EN))
		return -EOPNOTSUPP;

	if (mmc_card_mmc(card) && is_trim_arg(arg) &&
	    !(card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN))
		return -EOPNOTSUPP;

	if (arg == MMC_SECURE_ERASE_ARG) {
		if (from % card->erase_size || nr % card->erase_size)
			return -EINVAL;
	}

	if (arg == MMC_ERASE_ARG)
		nr = mmc_align_erase_size(card, &from, &to, nr);

	if (nr == 0)
		return 0;

	if (to <= from)
		return -EINVAL;

	/* 'from' and 'to' are inclusive */
	to -= 1;

	/*
	 * Special case where only one erase-group fits in the timeout budget:
	 * If the region crosses an erase-group boundary on this particular
	 * case, we will be trimming more than one erase-group which, does not
	 * fit in the timeout budget of the controller, so we need to split it
	 * and call mmc_do_erase() twice if necessary. This special case is
	 * identified by the card->eg_boundary flag.
	 */
	rem = card->erase_size - (from % card->erase_size);
	if ((arg & MMC_TRIM_OR_DISCARD_ARGS) && card->eg_boundary && nr > rem) {
		err = mmc_do_erase(card, from, from + rem - 1, arg);
		from += rem;
		if ((err) || (to <= from))
			return err;
	}

	return mmc_do_erase(card, from, to, arg);
}
EXPORT_SYMBOL(mmc_erase);

int mmc_can_erase(struct mmc_card *card)
{
	if (card->csd.cmdclass & CCC_ERASE && card->erase_size)
		return 1;
	return 0;
}
EXPORT_SYMBOL(mmc_can_erase);

int mmc_can_trim(struct mmc_card *card)
{
	if ((card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN) &&
	    (!(card->quirks & MMC_QUIRK_TRIM_BROKEN)))
		return 1;
	return 0;
}
EXPORT_SYMBOL(mmc_can_trim);

int mmc_can_discard(struct mmc_card *card)
{
	/*
	 * As there's no way to detect the discard support bit at v4.5
	 * use the s/w feature support filed.
	 */
	if (card->ext_csd.feature_support & MMC_DISCARD_FEATURE)
		return 1;
	return 0;
}
EXPORT_SYMBOL(mmc_can_discard);

int mmc_can_sanitize(struct mmc_card *card)
{
	if (!mmc_can_trim(card) && !mmc_can_erase(card))
		return 0;
	if (card->ext_csd.sec_feature_support & EXT_CSD_SEC_SANITIZE)
		return 1;
	return 0;
}

int mmc_can_secure_erase_trim(struct mmc_card *card)
{
	if ((card->ext_csd.sec_feature_support & EXT_CSD_SEC_ER_EN) &&
	    !(card->quirks & MMC_QUIRK_SEC_ERASE_TRIM_BROKEN))
		return 1;
	return 0;
}
EXPORT_SYMBOL(mmc_can_secure_erase_trim);

int mmc_erase_group_aligned(struct mmc_card *card, unsigned int from,
			    unsigned int nr)
{
	if (!card->erase_size)
		return 0;
	if (from % card->erase_size || nr % card->erase_size)
		return 0;
	return 1;
}
EXPORT_SYMBOL(mmc_erase_group_aligned);

static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
					    unsigned int arg)
{
	struct mmc_host *host = card->host;
	unsigned int max_discard, x, y, qty = 0, max_qty, min_qty, timeout;
	unsigned int last_timeout = 0;
	unsigned int max_busy_timeout = host->max_busy_timeout ?
			host->max_busy_timeout : MMC_ERASE_TIMEOUT_MS;

	if (card->erase_shift) {
		max_qty = UINT_MAX >> card->erase_shift;
		min_qty = card->pref_erase >> card->erase_shift;
	} else if (mmc_card_sd(card)) {
		max_qty = UINT_MAX;
		min_qty = card->pref_erase;
	} else {
		max_qty = UINT_MAX / card->erase_size;
		min_qty = card->pref_erase / card->erase_size;
	}

	/*
	 * We should not only use 'host->max_busy_timeout' as the limitation
	 * when deciding the max discard sectors. We should set a balance value
	 * to improve the erase speed, and it can not get too long timeout at
	 * the same time.
	 *
	 * Here we set 'card->pref_erase' as the minimal discard sectors no
	 * matter what size of 'host->max_busy_timeout', but if the
	 * 'host->max_busy_timeout' is large enough for more discard sectors,
	 * then we can continue to increase the max discard sectors until we
	 * get a balance value. In cases when the 'host->max_busy_timeout'
	 * isn't specified, use the default max erase timeout.
	 */
	do {
		y = 0;
		for (x = 1; x && x <= max_qty && max_qty - x >= qty; x <<= 1) {
			timeout = mmc_erase_timeout(card, arg, qty + x);

			if (qty + x > min_qty && timeout > max_busy_timeout)
				break;

			if (timeout < last_timeout)
				break;
			last_timeout = timeout;
			y = x;
		}
		qty += y;
	} while (y);

	if (!qty)
		return 0;

	/*
	 * When specifying a sector range to trim, chances are we might cross
	 * an erase-group boundary even if the amount of sectors is less than
	 * one erase-group.
	 * If we can only fit one erase-group in the controller timeout budget,
	 * we have to care that erase-group boundaries are not crossed by a
	 * single trim operation. We flag that special case with "eg_boundary".
	 * In all other cases we can just decrement qty and pretend that we
	 * always touch (qty + 1) erase-groups as a simple optimization.
	 */
	if (qty == 1)
		card->eg_boundary = 1;
	else
		qty--;

	/* Convert qty to sectors */
	if (card->erase_shift)
		max_discard = qty << card->erase_shift;
	else if (mmc_card_sd(card))
		max_discard = qty + 1;
	else
		max_discard = qty * card->erase_size;

	return max_discard;
}

unsigned int mmc_calc_max_discard(struct mmc_card *card)
{
	struct mmc_host *host = card->host;
	unsigned int max_discard, max_trim;

	/*
	 * Without erase_group_def set, MMC erase timeout depends on clock
	 * frequence which can change.  In that case, the best choice is
	 * just the preferred erase size.
	 */
	if (mmc_card_mmc(card) && !(card->ext_csd.erase_group_def & 1))
		return card->pref_erase;

	max_discard = mmc_do_calc_max_discard(card, MMC_ERASE_ARG);
	if (mmc_can_trim(card)) {
		max_trim = mmc_do_calc_max_discard(card, MMC_TRIM_ARG);
		if (max_trim < max_discard || max_discard == 0)
			max_discard = max_trim;
	} else if (max_discard < card->erase_size) {
		max_discard = 0;
	}
	pr_debug("%s: calculated max. discard sectors %u for timeout %u ms\n",
		mmc_hostname(host), max_discard, host->max_busy_timeout ?
		host->max_busy_timeout : MMC_ERASE_TIMEOUT_MS);
	return max_discard;
}
EXPORT_SYMBOL(mmc_calc_max_discard);

bool mmc_card_is_blockaddr(struct mmc_card *card)
{
	return card ? mmc_card_blockaddr(card) : false;
}
EXPORT_SYMBOL(mmc_card_is_blockaddr);

int mmc_set_blocklen(struct mmc_card *card, unsigned int blocklen)
{
	struct mmc_command cmd = {};

	if (mmc_card_blockaddr(card) || mmc_card_ddr52(card) ||
	    mmc_card_hs400(card) || mmc_card_hs400es(card))
		return 0;

	cmd.opcode = MMC_SET_BLOCKLEN;
	cmd.arg = blocklen;
	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
	return mmc_wait_for_cmd(card->host, &cmd, 5);
}
EXPORT_SYMBOL(mmc_set_blocklen);

static void mmc_hw_reset_for_init(struct mmc_host *host)
{
	mmc_pwrseq_reset(host);

	if (!(host->caps & MMC_CAP_HW_RESET) || !host->ops->card_hw_reset)
		return;
	host->ops->card_hw_reset(host);
}

/**
 * mmc_hw_reset - reset the card in hardware
 * @card: card to be reset
 *
 * Hard reset the card. This function is only for upper layers, like the
 * block layer or card drivers. You cannot use it in host drivers (struct
 * mmc_card might be gone then).
 *
 * Return: 0 on success, -errno on failure
 */
int mmc_hw_reset(struct mmc_card *card)
{
	struct mmc_host *host = card->host;
	int ret;

	ret = host->bus_ops->hw_reset(host);
	if (ret < 0)
		pr_warn("%s: tried to HW reset card, got error %d\n",
			mmc_hostname(host), ret);

	return ret;
}
EXPORT_SYMBOL(mmc_hw_reset);

int mmc_sw_reset(struct mmc_card *card)
{
	struct mmc_host *host = card->host;
	int ret;

	if (!host->bus_ops->sw_reset)
		return -EOPNOTSUPP;

	ret = host->bus_ops->sw_reset(host);
	if (ret)
		pr_warn("%s: tried to SW reset card, got error %d\n",
			mmc_hostname(host), ret);

	return ret;
}
EXPORT_SYMBOL(mmc_sw_reset);

static int mmc_rescan_try_freq(struct mmc_host *host, unsigned freq)
{
	host->f_init = freq;

	pr_debug("%s: %s: trying to init card at %u Hz\n",
		mmc_hostname(host), __func__, host->f_init);

	mmc_power_up(host, host->ocr_avail);

	/*
	 * Some eMMCs (with VCCQ always on) may not be reset after power up, so
	 * do a hardware reset if possible.
	 */
	mmc_hw_reset_for_init(host);

	/*
	 * sdio_reset sends CMD52 to reset card.  Since we do not know
	 * if the card is being re-initialized, just send it.  CMD52
	 * should be ignored by SD/eMMC cards.
	 * Skip it if we already know that we do not support SDIO commands
	 */
	if (!(host->caps2 & MMC_CAP2_NO_SDIO))
		sdio_reset(host);

	mmc_go_idle(host);

	if (!(host->caps2 & MMC_CAP2_NO_SD)) {
		if (mmc_send_if_cond_pcie(host, host->ocr_avail))
			goto out;
		if (mmc_card_sd_express(host))
			return 0;
	}

	/* Order's important: probe SDIO, then SD, then MMC */
	if (!(host->caps2 & MMC_CAP2_NO_SDIO))
		if (!mmc_attach_sdio(host))
			return 0;

	if (!(host->caps2 & MMC_CAP2_NO_SD))
		if (!mmc_attach_sd(host))
			return 0;

	if (!(host->caps2 & MMC_CAP2_NO_MMC))
		if (!mmc_attach_mmc(host))
			return 0;

out:
	mmc_power_off(host);
	return -EIO;
}

int _mmc_detect_card_removed(struct mmc_host *host)
{
	int ret;

	if (!host->card || mmc_card_removed(host->card))
		return 1;

	ret = host->bus_ops->alive(host);

	/*
	 * Card detect status and alive check may be out of sync if card is
	 * removed slowly, when card detect switch changes while card/slot
	 * pads are still contacted in hardware (refer to "SD Card Mechanical
	 * Addendum, Appendix C: Card Detection Switch"). So reschedule a
	 * detect work 200ms later for this case.
	 */
	if (!ret && host->ops->get_cd && !host->ops->get_cd(host)) {
		mmc_detect_change(host, msecs_to_jiffies(200));
		pr_debug("%s: card removed too slowly\n", mmc_hostname(host));
	}

	if (ret) {
		mmc_card_set_removed(host->card);
		pr_debug("%s: card remove detected\n", mmc_hostname(host));
	}

	return ret;
}

int mmc_detect_card_removed(struct mmc_host *host)
{
	struct mmc_card *card = host->card;
	int ret;

	WARN_ON(!host->claimed);

	if (!card)
		return 1;

	if (!mmc_card_is_removable(host))
		return 0;

	ret = mmc_card_removed(card);
	/*
	 * The card will be considered unchanged unless we have been asked to
	 * detect a change or host requires polling to provide card detection.
	 */
	if (!host->detect_change && !(host->caps & MMC_CAP_NEEDS_POLL))
		return ret;

	host->detect_change = 0;
	if (!ret) {
		ret = _mmc_detect_card_removed(host);
		if (ret && (host->caps & MMC_CAP_NEEDS_POLL)) {
			/*
			 * Schedule a detect work as soon as possible to let a
			 * rescan handle the card removal.
			 */
			cancel_delayed_work(&host->detect);
			_mmc_detect_change(host, 0, false);
		}
	}

	return ret;
}
EXPORT_SYMBOL(mmc_detect_card_removed);

int mmc_card_alternative_gpt_sector(struct mmc_card *card, sector_t *gpt_sector)
{
	unsigned int boot_sectors_num;

	if ((!(card->host->caps2 & MMC_CAP2_ALT_GPT_TEGRA)))
		return -EOPNOTSUPP;

	/* filter out unrelated cards */
	if (card->ext_csd.rev < 3 ||
	    !mmc_card_mmc(card) ||
	    !mmc_card_is_blockaddr(card) ||
	     mmc_card_is_removable(card->host))
		return -ENOENT;

	/*
	 * eMMC storage has two special boot partitions in addition to the
	 * main one.  NVIDIA's bootloader linearizes eMMC boot0->boot1->main
	 * accesses, this means that the partition table addresses are shifted
	 * by the size of boot partitions.  In accordance with the eMMC
	 * specification, the boot partition size is calculated as follows:
	 *
	 *	boot partition size = 128K byte x BOOT_SIZE_MULT
	 *
	 * Calculate number of sectors occupied by the both boot partitions.
	 */
	boot_sectors_num = card->ext_csd.raw_boot_mult * SZ_128K /
			   SZ_512 * MMC_NUM_BOOT_PARTITION;

	/* Defined by NVIDIA and used by Android devices. */
	*gpt_sector = card->ext_csd.sectors - boot_sectors_num - 1;

	return 0;
}
EXPORT_SYMBOL(mmc_card_alternative_gpt_sector);

void mmc_rescan(struct work_struct *work)
{
	struct mmc_host *host =
		container_of(work, struct mmc_host, detect.work);
	int i;

	if (host->rescan_disable)
		return;

	/* If there is a non-removable card registered, only scan once */
	if (!mmc_card_is_removable(host) && host->rescan_entered)
		return;
	host->rescan_entered = 1;

	if (host->trigger_card_event && host->ops->card_event) {
		mmc_claim_host(host);
		host->ops->card_event(host);
		mmc_release_host(host);
		host->trigger_card_event = false;
	}

	/* Verify a registered card to be functional, else remove it. */
	if (host->bus_ops)
		host->bus_ops->detect(host);

	host->detect_change = 0;

	/* if there still is a card present, stop here */
	if (host->bus_ops != NULL)
		goto out;

	mmc_claim_host(host);
	if (mmc_card_is_removable(host) && host->ops->get_cd &&
			host->ops->get_cd(host) == 0) {
		mmc_power_off(host);
		mmc_release_host(host);
		goto out;
	}

	/* If an SD express card is present, then leave it as is. */
	if (mmc_card_sd_express(host)) {
		mmc_release_host(host);
		goto out;
	}

	for (i = 0; i < ARRAY_SIZE(freqs); i++) {
		unsigned int freq = freqs[i];
		if (freq > host->f_max) {
			if (i + 1 < ARRAY_SIZE(freqs))
				continue;
			freq = host->f_max;
		}
		if (!mmc_rescan_try_freq(host, max(freq, host->f_min)))
			break;
		if (freqs[i] <= host->f_min)
			break;
	}

	/* A non-removable card should have been detected by now. */
	if (!mmc_card_is_removable(host) && !host->bus_ops)
		pr_info("%s: Failed to initialize a non-removable card",
			mmc_hostname(host));

	/*
	 * Ignore the command timeout errors observed during
	 * the card init as those are excepted.
	 */
	host->err_stats[MMC_ERR_CMD_TIMEOUT] = 0;
	mmc_release_host(host);

 out:
	if (host->caps & MMC_CAP_NEEDS_POLL)
		mmc_schedule_delayed_work(&host->detect, HZ);
}

void mmc_start_host(struct mmc_host *host)
{
	host->f_init = max(min(freqs[0], host->f_max), host->f_min);
	host->rescan_disable = 0;

	if (!(host->caps2 & MMC_CAP2_NO_PRESCAN_POWERUP)) {
		mmc_claim_host(host);
		mmc_power_up(host, host->ocr_avail);
		mmc_release_host(host);
	}

	mmc_gpiod_request_cd_irq(host);
	_mmc_detect_change(host, 0, false);
}

void __mmc_stop_host(struct mmc_host *host)
{
	if (host->slot.cd_irq >= 0) {
		mmc_gpio_set_cd_wake(host, false);
		disable_irq(host->slot.cd_irq);
	}

	host->rescan_disable = 1;
	cancel_delayed_work_sync(&host->detect);
}

void mmc_stop_host(struct mmc_host *host)
{
	__mmc_stop_host(host);

	/* clear pm flags now and let card drivers set them as needed */
	host->pm_flags = 0;

	if (host->bus_ops) {
		/* Calling bus_ops->remove() with a claimed host can deadlock */
		host->bus_ops->remove(host);
		mmc_claim_host(host);
		mmc_detach_bus(host);
		mmc_power_off(host);
		mmc_release_host(host);
		return;
	}

	mmc_claim_host(host);
	mmc_power_off(host);
	mmc_release_host(host);
}

static int __init mmc_init(void)
{
	int ret;

	ret = mmc_register_bus();
	if (ret)
		return ret;

	ret = mmc_register_host_class();
	if (ret)
		goto unregister_bus;

	ret = sdio_register_bus();
	if (ret)
		goto unregister_host_class;

	return 0;

unregister_host_class:
	mmc_unregister_host_class();
unregister_bus:
	mmc_unregister_bus();
	return ret;
}

static void __exit mmc_exit(void)
{
	sdio_unregister_bus();
	mmc_unregister_host_class();
	mmc_unregister_bus();
}

subsys_initcall(mmc_init);
module_exit(mmc_exit);

MODULE_LICENSE("GPL");