aboutsummaryrefslogtreecommitdiff
path: root/drivers/pci/pci-sysfs.c
blob: 63d5042f2079141a8740d77fae118d9c5bb707af (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
/*
 * drivers/pci/pci-sysfs.c
 *
 * (C) Copyright 2002-2004 Greg Kroah-Hartman <greg@kroah.com>
 * (C) Copyright 2002-2004 IBM Corp.
 * (C) Copyright 2003 Matthew Wilcox
 * (C) Copyright 2003 Hewlett-Packard
 * (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com>
 * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com>
 *
 * File attributes for PCI devices
 *
 * Modeled after usb's driverfs.c 
 *
 */


#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/pci.h>
#include <linux/stat.h>
#include <linux/topology.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/capability.h>
#include <linux/pci-aspm.h>
#include <linux/slab.h>
#include "pci.h"

static int sysfs_initialized;	/* = 0 */

/* show configuration fields */
#define pci_config_attr(field, format_string)				\
static ssize_t								\
field##_show(struct device *dev, struct device_attribute *attr, char *buf)				\
{									\
	struct pci_dev *pdev;						\
									\
	pdev = to_pci_dev (dev);					\
	return sprintf (buf, format_string, pdev->field);		\
}

pci_config_attr(vendor, "0x%04x\n");
pci_config_attr(device, "0x%04x\n");
pci_config_attr(subsystem_vendor, "0x%04x\n");
pci_config_attr(subsystem_device, "0x%04x\n");
pci_config_attr(class, "0x%06x\n");
pci_config_attr(irq, "%u\n");

static ssize_t broken_parity_status_show(struct device *dev,
					 struct device_attribute *attr,
					 char *buf)
{
	struct pci_dev *pdev = to_pci_dev(dev);
	return sprintf (buf, "%u\n", pdev->broken_parity_status);
}

static ssize_t broken_parity_status_store(struct device *dev,
					  struct device_attribute *attr,
					  const char *buf, size_t count)
{
	struct pci_dev *pdev = to_pci_dev(dev);
	unsigned long val;

	if (strict_strtoul(buf, 0, &val) < 0)
		return -EINVAL;

	pdev->broken_parity_status = !!val;

	return count;
}

static ssize_t local_cpus_show(struct device *dev,
			struct device_attribute *attr, char *buf)
{		
	const struct cpumask *mask;
	int len;

#ifdef CONFIG_NUMA
	mask = (dev_to_node(dev) == -1) ? cpu_online_mask :
					  cpumask_of_node(dev_to_node(dev));
#else
	mask = cpumask_of_pcibus(to_pci_dev(dev)->bus);
#endif
	len = cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
	buf[len++] = '\n';
	buf[len] = '\0';
	return len;
}


static ssize_t local_cpulist_show(struct device *dev,
			struct device_attribute *attr, char *buf)
{
	const struct cpumask *mask;
	int len;

#ifdef CONFIG_NUMA
	mask = (dev_to_node(dev) == -1) ? cpu_online_mask :
					  cpumask_of_node(dev_to_node(dev));
#else
	mask = cpumask_of_pcibus(to_pci_dev(dev)->bus);
#endif
	len = cpulist_scnprintf(buf, PAGE_SIZE-2, mask);
	buf[len++] = '\n';
	buf[len] = '\0';
	return len;
}

/* show resources */
static ssize_t
resource_show(struct device * dev, struct device_attribute *attr, char * buf)
{
	struct pci_dev * pci_dev = to_pci_dev(dev);
	char * str = buf;
	int i;
	int max;
	resource_size_t start, end;

	if (pci_dev->subordinate)
		max = DEVICE_COUNT_RESOURCE;
	else
		max = PCI_BRIDGE_RESOURCES;

	for (i = 0; i < max; i++) {
		struct resource *res =  &pci_dev->resource[i];
		pci_resource_to_user(pci_dev, i, res, &start, &end);
		str += sprintf(str,"0x%016llx 0x%016llx 0x%016llx\n",
			       (unsigned long long)start,
			       (unsigned long long)end,
			       (unsigned long long)res->flags);
	}
	return (str - buf);
}

static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct pci_dev *pci_dev = to_pci_dev(dev);

	return sprintf(buf, "pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02x\n",
		       pci_dev->vendor, pci_dev->device,
		       pci_dev->subsystem_vendor, pci_dev->subsystem_device,
		       (u8)(pci_dev->class >> 16), (u8)(pci_dev->class >> 8),
		       (u8)(pci_dev->class));
}

static ssize_t is_enabled_store(struct device *dev,
				struct device_attribute *attr, const char *buf,
				size_t count)
{
	struct pci_dev *pdev = to_pci_dev(dev);
	unsigned long val;
	ssize_t result = strict_strtoul(buf, 0, &val);

	if (result < 0)
		return result;

	/* this can crash the machine when done on the "wrong" device */
	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	if (!val) {
		if (pci_is_enabled(pdev))
			pci_disable_device(pdev);
		else
			result = -EIO;
	} else
		result = pci_enable_device(pdev);

	return result < 0 ? result : count;
}

static ssize_t is_enabled_show(struct device *dev,
			       struct device_attribute *attr, char *buf)
{
	struct pci_dev *pdev;

	pdev = to_pci_dev (dev);
	return sprintf (buf, "%u\n", atomic_read(&pdev->enable_cnt));
}

#ifdef CONFIG_NUMA
static ssize_t
numa_node_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	return sprintf (buf, "%d\n", dev->numa_node);
}
#endif

static ssize_t
dma_mask_bits_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct pci_dev *pdev = to_pci_dev(dev);

	return sprintf (buf, "%d\n", fls64(pdev->dma_mask));
}

static ssize_t
consistent_dma_mask_bits_show(struct device *dev, struct device_attribute *attr,
				 char *buf)
{
	return sprintf (buf, "%d\n", fls64(dev->coherent_dma_mask));
}

static ssize_t
msi_bus_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct pci_dev *pdev = to_pci_dev(dev);

	if (!pdev->subordinate)
		return 0;

	return sprintf (buf, "%u\n",
			!(pdev->subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI));
}

static ssize_t
msi_bus_store(struct device *dev, struct device_attribute *attr,
	      const char *buf, size_t count)
{
	struct pci_dev *pdev = to_pci_dev(dev);
	unsigned long val;

	if (strict_strtoul(buf, 0, &val) < 0)
		return -EINVAL;

	/* bad things may happen if the no_msi flag is changed
	 * while some drivers are loaded */
	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	/* Maybe pci devices without subordinate busses shouldn't even have this
	 * attribute in the first place?  */
	if (!pdev->subordinate)
		return count;

	/* Is the flag going to change, or keep the value it already had? */
	if (!(pdev->subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI) ^
	    !!val) {
		pdev->subordinate->bus_flags ^= PCI_BUS_FLAGS_NO_MSI;

		dev_warn(&pdev->dev, "forced subordinate bus to%s support MSI,"
			 " bad things could happen\n", val ? "" : " not");
	}

	return count;
}

#ifdef CONFIG_HOTPLUG
static DEFINE_MUTEX(pci_remove_rescan_mutex);
static ssize_t bus_rescan_store(struct bus_type *bus, const char *buf,
				size_t count)
{
	unsigned long val;
	struct pci_bus *b = NULL;

	if (strict_strtoul(buf, 0, &val) < 0)
		return -EINVAL;

	if (val) {
		mutex_lock(&pci_remove_rescan_mutex);
		while ((b = pci_find_next_bus(b)) != NULL)
			pci_rescan_bus(b);
		mutex_unlock(&pci_remove_rescan_mutex);
	}
	return count;
}

struct bus_attribute pci_bus_attrs[] = {
	__ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, bus_rescan_store),
	__ATTR_NULL
};

static ssize_t
dev_rescan_store(struct device *dev, struct device_attribute *attr,
		 const char *buf, size_t count)
{
	unsigned long val;
	struct pci_dev *pdev = to_pci_dev(dev);

	if (strict_strtoul(buf, 0, &val) < 0)
		return -EINVAL;

	if (val) {
		mutex_lock(&pci_remove_rescan_mutex);
		pci_rescan_bus(pdev->bus);
		mutex_unlock(&pci_remove_rescan_mutex);
	}
	return count;
}

static void remove_callback(struct device *dev)
{
	struct pci_dev *pdev = to_pci_dev(dev);

	mutex_lock(&pci_remove_rescan_mutex);
	pci_remove_bus_device(pdev);
	mutex_unlock(&pci_remove_rescan_mutex);
}

static ssize_t
remove_store(struct device *dev, struct device_attribute *dummy,
	     const char *buf, size_t count)
{
	int ret = 0;
	unsigned long val;

	if (strict_strtoul(buf, 0, &val) < 0)
		return -EINVAL;

	/* An attribute cannot be unregistered by one of its own methods,
	 * so we have to use this roundabout approach.
	 */
	if (val)
		ret = device_schedule_callback(dev, remove_callback);
	if (ret)
		count = ret;
	return count;
}
#endif

struct device_attribute pci_dev_attrs[] = {
	__ATTR_RO(resource),
	__ATTR_RO(vendor),
	__ATTR_RO(device),
	__ATTR_RO(subsystem_vendor),
	__ATTR_RO(subsystem_device),
	__ATTR_RO(class),
	__ATTR_RO(irq),
	__ATTR_RO(local_cpus),
	__ATTR_RO(local_cpulist),
	__ATTR_RO(modalias),
#ifdef CONFIG_NUMA
	__ATTR_RO(numa_node),
#endif
	__ATTR_RO(dma_mask_bits),
	__ATTR_RO(consistent_dma_mask_bits),
	__ATTR(enable, 0600, is_enabled_show, is_enabled_store),
	__ATTR(broken_parity_status,(S_IRUGO|S_IWUSR),
		broken_parity_status_show,broken_parity_status_store),
	__ATTR(msi_bus, 0644, msi_bus_show, msi_bus_store),
#ifdef CONFIG_HOTPLUG
	__ATTR(remove, (S_IWUSR|S_IWGRP), NULL, remove_store),
	__ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, dev_rescan_store),
#endif
	__ATTR_NULL,
};

static ssize_t
boot_vga_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct pci_dev *pdev = to_pci_dev(dev);

	return sprintf(buf, "%u\n",
		!!(pdev->resource[PCI_ROM_RESOURCE].flags &
		   IORESOURCE_ROM_SHADOW));
}
struct device_attribute vga_attr = __ATTR_RO(boot_vga);

static ssize_t
pci_read_config(struct file *filp, struct kobject *kobj,
		struct bin_attribute *bin_attr,
		char *buf, loff_t off, size_t count)
{
	struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
	unsigned int size = 64;
	loff_t init_off = off;
	u8 *data = (u8*) buf;

	/* Several chips lock up trying to read undefined config space */
	if (cap_raised(filp->f_cred->cap_effective, CAP_SYS_ADMIN)) {
		size = dev->cfg_size;
	} else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
		size = 128;
	}

	if (off > size)
		return 0;
	if (off + count > size) {
		size -= off;
		count = size;
	} else {
		size = count;
	}

	if ((off & 1) && size) {
		u8 val;
		pci_user_read_config_byte(dev, off, &val);
		data[off - init_off] = val;
		off++;
		size--;
	}

	if ((off & 3) && size > 2) {
		u16 val;
		pci_user_read_config_word(dev, off, &val);
		data[off - init_off] = val & 0xff;
		data[off - init_off + 1] = (val >> 8) & 0xff;
		off += 2;
		size -= 2;
	}

	while (size > 3) {
		u32 val;
		pci_user_read_config_dword(dev, off, &val);
		data[off - init_off] = val & 0xff;
		data[off - init_off + 1] = (val >> 8) & 0xff;
		data[off - init_off + 2] = (val >> 16) & 0xff;
		data[off - init_off + 3] = (val >> 24) & 0xff;
		off += 4;
		size -= 4;
	}

	if (size >= 2) {
		u16 val;
		pci_user_read_config_word(dev, off, &val);
		data[off - init_off] = val & 0xff;
		data[off - init_off + 1] = (val >> 8) & 0xff;
		off += 2;
		size -= 2;
	}

	if (size > 0) {
		u8 val;
		pci_user_read_config_byte(dev, off, &val);
		data[off - init_off] = val;
		off++;
		--size;
	}

	return count;
}

static ssize_t
pci_write_config(struct file* filp, struct kobject *kobj,
		 struct bin_attribute *bin_attr,
		 char *buf, loff_t off, size_t count)
{
	struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
	unsigned int size = count;
	loff_t init_off = off;
	u8 *data = (u8*) buf;

	if (off > dev->cfg_size)
		return 0;
	if (off + count > dev->cfg_size) {
		size = dev->cfg_size - off;
		count = size;
	}
	
	if ((off & 1) && size) {
		pci_user_write_config_byte(dev, off, data[off - init_off]);
		off++;
		size--;
	}
	
	if ((off & 3) && size > 2) {
		u16 val = data[off - init_off];
		val |= (u16) data[off - init_off + 1] << 8;
                pci_user_write_config_word(dev, off, val);
                off += 2;
                size -= 2;
        }

	while (size > 3) {
		u32 val = data[off - init_off];
		val |= (u32) data[off - init_off + 1] << 8;
		val |= (u32) data[off - init_off + 2] << 16;
		val |= (u32) data[off - init_off + 3] << 24;
		pci_user_write_config_dword(dev, off, val);
		off += 4;
		size -= 4;
	}
	
	if (size >= 2) {
		u16 val = data[off - init_off];
		val |= (u16) data[off - init_off + 1] << 8;
		pci_user_write_config_word(dev, off, val);
		off += 2;
		size -= 2;
	}

	if (size) {
		pci_user_write_config_byte(dev, off, data[off - init_off]);
		off++;
		--size;
	}

	return count;
}

static ssize_t
read_vpd_attr(struct file *filp, struct kobject *kobj,
	      struct bin_attribute *bin_attr,
	      char *buf, loff_t off, size_t count)
{
	struct pci_dev *dev =
		to_pci_dev(container_of(kobj, struct device, kobj));

	if (off > bin_attr->size)
		count = 0;
	else if (count > bin_attr->size - off)
		count = bin_attr->size - off;

	return pci_read_vpd(dev, off, count, buf);
}

static ssize_t
write_vpd_attr(struct file *filp, struct kobject *kobj,
	       struct bin_attribute *bin_attr,
	       char *buf, loff_t off, size_t count)
{
	struct pci_dev *dev =
		to_pci_dev(container_of(kobj, struct device, kobj));

	if (off > bin_attr->size)
		count = 0;
	else if (count > bin_attr->size - off)
		count = bin_attr->size - off;

	return pci_write_vpd(dev, off, count, buf);
}

#ifdef HAVE_PCI_LEGACY
/**
 * pci_read_legacy_io - read byte(s) from legacy I/O port space
 * @filp: open sysfs file
 * @kobj: kobject corresponding to file to read from
 * @bin_attr: struct bin_attribute for this file
 * @buf: buffer to store results
 * @off: offset into legacy I/O port space
 * @count: number of bytes to read
 *
 * Reads 1, 2, or 4 bytes from legacy I/O port space using an arch specific
 * callback routine (pci_legacy_read).
 */
static ssize_t
pci_read_legacy_io(struct file *filp, struct kobject *kobj,
		   struct bin_attribute *bin_attr,
		   char *buf, loff_t off, size_t count)
{
        struct pci_bus *bus = to_pci_bus(container_of(kobj,
                                                      struct device,
						      kobj));

        /* Only support 1, 2 or 4 byte accesses */
        if (count != 1 && count != 2 && count != 4)
                return -EINVAL;

        return pci_legacy_read(bus, off, (u32 *)buf, count);
}

/**
 * pci_write_legacy_io - write byte(s) to legacy I/O port space
 * @filp: open sysfs file
 * @kobj: kobject corresponding to file to read from
 * @bin_attr: struct bin_attribute for this file
 * @buf: buffer containing value to be written
 * @off: offset into legacy I/O port space
 * @count: number of bytes to write
 *
 * Writes 1, 2, or 4 bytes from legacy I/O port space using an arch specific
 * callback routine (pci_legacy_write).
 */
static ssize_t
pci_write_legacy_io(struct file *filp, struct kobject *kobj,
		    struct bin_attribute *bin_attr,
		    char *buf, loff_t off, size_t count)
{
        struct pci_bus *bus = to_pci_bus(container_of(kobj,
						      struct device,
						      kobj));
        /* Only support 1, 2 or 4 byte accesses */
        if (count != 1 && count != 2 && count != 4)
                return -EINVAL;

        return pci_legacy_write(bus, off, *(u32 *)buf, count);
}

/**
 * pci_mmap_legacy_mem - map legacy PCI memory into user memory space
 * @filp: open sysfs file
 * @kobj: kobject corresponding to device to be mapped
 * @attr: struct bin_attribute for this file
 * @vma: struct vm_area_struct passed to mmap
 *
 * Uses an arch specific callback, pci_mmap_legacy_mem_page_range, to mmap
 * legacy memory space (first meg of bus space) into application virtual
 * memory space.
 */
static int
pci_mmap_legacy_mem(struct file *filp, struct kobject *kobj,
		    struct bin_attribute *attr,
                    struct vm_area_struct *vma)
{
        struct pci_bus *bus = to_pci_bus(container_of(kobj,
                                                      struct device,
						      kobj));

        return pci_mmap_legacy_page_range(bus, vma, pci_mmap_mem);
}

/**
 * pci_mmap_legacy_io - map legacy PCI IO into user memory space
 * @filp: open sysfs file
 * @kobj: kobject corresponding to device to be mapped
 * @attr: struct bin_attribute for this file
 * @vma: struct vm_area_struct passed to mmap
 *
 * Uses an arch specific callback, pci_mmap_legacy_io_page_range, to mmap
 * legacy IO space (first meg of bus space) into application virtual
 * memory space. Returns -ENOSYS if the operation isn't supported
 */
static int
pci_mmap_legacy_io(struct file *filp, struct kobject *kobj,
		   struct bin_attribute *attr,
		   struct vm_area_struct *vma)
{
        struct pci_bus *bus = to_pci_bus(container_of(kobj,
                                                      struct device,
						      kobj));

        return pci_mmap_legacy_page_range(bus, vma, pci_mmap_io);
}

/**
 * pci_adjust_legacy_attr - adjustment of legacy file attributes
 * @b: bus to create files under
 * @mmap_type: I/O port or memory
 *
 * Stub implementation. Can be overridden by arch if necessary.
 */
void __weak
pci_adjust_legacy_attr(struct pci_bus *b, enum pci_mmap_state mmap_type)
{
	return;
}

/**
 * pci_create_legacy_files - create legacy I/O port and memory files
 * @b: bus to create files under
 *
 * Some platforms allow access to legacy I/O port and ISA memory space on
 * a per-bus basis.  This routine creates the files and ties them into
 * their associated read, write and mmap files from pci-sysfs.c
 *
 * On error unwind, but don't propogate the error to the caller
 * as it is ok to set up the PCI bus without these files.
 */
void pci_create_legacy_files(struct pci_bus *b)
{
	int error;

	b->legacy_io = kzalloc(sizeof(struct bin_attribute) * 2,
			       GFP_ATOMIC);
	if (!b->legacy_io)
		goto kzalloc_err;

	sysfs_bin_attr_init(b->legacy_io);
	b->legacy_io->attr.name = "legacy_io";
	b->legacy_io->size = 0xffff;
	b->legacy_io->attr.mode = S_IRUSR | S_IWUSR;
	b->legacy_io->read = pci_read_legacy_io;
	b->legacy_io->write = pci_write_legacy_io;
	b->legacy_io->mmap = pci_mmap_legacy_io;
	pci_adjust_legacy_attr(b, pci_mmap_io);
	error = device_create_bin_file(&b->dev, b->legacy_io);
	if (error)
		goto legacy_io_err;

	/* Allocated above after the legacy_io struct */
	b->legacy_mem = b->legacy_io + 1;
	sysfs_bin_attr_init(b->legacy_mem);
	b->legacy_mem->attr.name = "legacy_mem";
	b->legacy_mem->size = 1024*1024;
	b->legacy_mem->attr.mode = S_IRUSR | S_IWUSR;
	b->legacy_mem->mmap = pci_mmap_legacy_mem;
	pci_adjust_legacy_attr(b, pci_mmap_mem);
	error = device_create_bin_file(&b->dev, b->legacy_mem);
	if (error)
		goto legacy_mem_err;

	return;

legacy_mem_err:
	device_remove_bin_file(&b->dev, b->legacy_io);
legacy_io_err:
	kfree(b->legacy_io);
	b->legacy_io = NULL;
kzalloc_err:
	printk(KERN_WARNING "pci: warning: could not create legacy I/O port "
	       "and ISA memory resources to sysfs\n");
	return;
}

void pci_remove_legacy_files(struct pci_bus *b)
{
	if (b->legacy_io) {
		device_remove_bin_file(&b->dev, b->legacy_io);
		device_remove_bin_file(&b->dev, b->legacy_mem);
		kfree(b->legacy_io); /* both are allocated here */
	}
}
#endif /* HAVE_PCI_LEGACY */

#ifdef HAVE_PCI_MMAP

int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma,
		  enum pci_mmap_api mmap_api)
{
	unsigned long nr, start, size, pci_start;

	if (pci_resource_len(pdev, resno) == 0)
		return 0;
	nr = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
	start = vma->vm_pgoff;
	size = ((pci_resource_len(pdev, resno) - 1) >> PAGE_SHIFT) + 1;
	pci_start = (mmap_api == PCI_MMAP_PROCFS) ?
			pci_resource_start(pdev, resno) >> PAGE_SHIFT : 0;
	if (start >= pci_start && start < pci_start + size &&
			start + nr <= pci_start + size)
		return 1;
	return 0;
}

/**
 * pci_mmap_resource - map a PCI resource into user memory space
 * @kobj: kobject for mapping
 * @attr: struct bin_attribute for the file being mapped
 * @vma: struct vm_area_struct passed into the mmap
 * @write_combine: 1 for write_combine mapping
 *
 * Use the regular PCI mapping routines to map a PCI resource into userspace.
 */
static int
pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
		  struct vm_area_struct *vma, int write_combine)
{
	struct pci_dev *pdev = to_pci_dev(container_of(kobj,
						       struct device, kobj));
	struct resource *res = attr->private;
	enum pci_mmap_state mmap_type;
	resource_size_t start, end;
	int i;

	for (i = 0; i < PCI_ROM_RESOURCE; i++)
		if (res == &pdev->resource[i])
			break;
	if (i >= PCI_ROM_RESOURCE)
		return -ENODEV;

	if (!pci_mmap_fits(pdev, i, vma, PCI_MMAP_SYSFS)) {
		WARN(1, "process \"%s\" tried to map 0x%08lx bytes "
			"at page 0x%08lx on %s BAR %d (start 0x%16Lx, size 0x%16Lx)\n",
			current->comm, vma->vm_end-vma->vm_start, vma->vm_pgoff,
			pci_name(pdev), i,
			(u64)pci_resource_start(pdev, i),
			(u64)pci_resource_len(pdev, i));
		return -EINVAL;
	}

	/* pci_mmap_page_range() expects the same kind of entry as coming
	 * from /proc/bus/pci/ which is a "user visible" value. If this is
	 * different from the resource itself, arch will do necessary fixup.
	 */
	pci_resource_to_user(pdev, i, res, &start, &end);
	vma->vm_pgoff += start >> PAGE_SHIFT;
	mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;

	if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(start))
		return -EINVAL;

	return pci_mmap_page_range(pdev, vma, mmap_type, write_combine);
}

static int
pci_mmap_resource_uc(struct file *filp, struct kobject *kobj,
		     struct bin_attribute *attr,
		     struct vm_area_struct *vma)
{
	return pci_mmap_resource(kobj, attr, vma, 0);
}

static int
pci_mmap_resource_wc(struct file *filp, struct kobject *kobj,
		     struct bin_attribute *attr,
		     struct vm_area_struct *vma)
{
	return pci_mmap_resource(kobj, attr, vma, 1);
}

static ssize_t
pci_resource_io(struct file *filp, struct kobject *kobj,
		struct bin_attribute *attr, char *buf,
		loff_t off, size_t count, bool write)
{
	struct pci_dev *pdev = to_pci_dev(container_of(kobj,
						       struct device, kobj));
	struct resource *res = attr->private;
	unsigned long port = off;
	int i;

	for (i = 0; i < PCI_ROM_RESOURCE; i++)
		if (res == &pdev->resource[i])
			break;
	if (i >= PCI_ROM_RESOURCE)
		return -ENODEV;

	port += pci_resource_start(pdev, i);

	if (port > pci_resource_end(pdev, i))
		return 0;

	if (port + count - 1 > pci_resource_end(pdev, i))
		return -EINVAL;

	switch (count) {
	case 1:
		if (write)
			outb(*(u8 *)buf, port);
		else
			*(u8 *)buf = inb(port);
		return 1;
	case 2:
		if (write)
			outw(*(u16 *)buf, port);
		else
			*(u16 *)buf = inw(port);
		return 2;
	case 4:
		if (write)
			outl(*(u32 *)buf, port);
		else
			*(u32 *)buf = inl(port);
		return 4;
	}
	return -EINVAL;
}

static ssize_t
pci_read_resource_io(struct file *filp, struct kobject *kobj,
		     struct bin_attribute *attr, char *buf,
		     loff_t off, size_t count)
{
	return pci_resource_io(filp, kobj, attr, buf, off, count, false);
}

static ssize_t
pci_write_resource_io(struct file *filp, struct kobject *kobj,
		      struct bin_attribute *attr, char *buf,
		      loff_t off, size_t count)
{
	return pci_resource_io(filp, kobj, attr, buf, off, count, true);
}

/**
 * pci_remove_resource_files - cleanup resource files
 * @pdev: dev to cleanup
 *
 * If we created resource files for @pdev, remove them from sysfs and
 * free their resources.
 */
static void
pci_remove_resource_files(struct pci_dev *pdev)
{
	int i;

	for (i = 0; i < PCI_ROM_RESOURCE; i++) {
		struct bin_attribute *res_attr;

		res_attr = pdev->res_attr[i];
		if (res_attr) {
			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
			kfree(res_attr);
		}

		res_attr = pdev->res_attr_wc[i];
		if (res_attr) {
			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
			kfree(res_attr);
		}
	}
}

static int pci_create_attr(struct pci_dev *pdev, int num, int write_combine)
{
	/* allocate attribute structure, piggyback attribute name */
	int name_len = write_combine ? 13 : 10;
	struct bin_attribute *res_attr;
	int retval;

	res_attr = kzalloc(sizeof(*res_attr) + name_len, GFP_ATOMIC);
	if (res_attr) {
		char *res_attr_name = (char *)(res_attr + 1);

		sysfs_bin_attr_init(res_attr);
		if (write_combine) {
			pdev->res_attr_wc[num] = res_attr;
			sprintf(res_attr_name, "resource%d_wc", num);
			res_attr->mmap = pci_mmap_resource_wc;
		} else {
			pdev->res_attr[num] = res_attr;
			sprintf(res_attr_name, "resource%d", num);
			res_attr->mmap = pci_mmap_resource_uc;
		}
		if (pci_resource_flags(pdev, num) & IORESOURCE_IO) {
			res_attr->read = pci_read_resource_io;
			res_attr->write = pci_write_resource_io;
		}
		res_attr->attr.name = res_attr_name;
		res_attr->attr.mode = S_IRUSR | S_IWUSR;
		res_attr->size = pci_resource_len(pdev, num);
		res_attr->private = &pdev->resource[num];
		retval = sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
	} else
		retval = -ENOMEM;

	return retval;
}

/**
 * pci_create_resource_files - create resource files in sysfs for @dev
 * @pdev: dev in question
 *
 * Walk the resources in @pdev creating files for each resource available.
 */
static int pci_create_resource_files(struct pci_dev *pdev)
{
	int i;
	int retval;

	/* Expose the PCI resources from this device as files */
	for (i = 0; i < PCI_ROM_RESOURCE; i++) {

		/* skip empty resources */
		if (!pci_resource_len(pdev, i))
			continue;

		retval = pci_create_attr(pdev, i, 0);
		/* for prefetchable resources, create a WC mappable file */
		if (!retval && pdev->resource[i].flags & IORESOURCE_PREFETCH)
			retval = pci_create_attr(pdev, i, 1);

		if (retval) {
			pci_remove_resource_files(pdev);
			return retval;
		}
	}
	return 0;
}
#else /* !HAVE_PCI_MMAP */
int __weak pci_create_resource_files(struct pci_dev *dev) { return 0; }
void __weak pci_remove_resource_files(struct pci_dev *dev) { return; }
#endif /* HAVE_PCI_MMAP */

/**
 * pci_write_rom - used to enable access to the PCI ROM display
 * @filp: sysfs file
 * @kobj: kernel object handle
 * @bin_attr: struct bin_attribute for this file
 * @buf: user input
 * @off: file offset
 * @count: number of byte in input
 *
 * writing anything except 0 enables it
 */
static ssize_t
pci_write_rom(struct file *filp, struct kobject *kobj,
	      struct bin_attribute *bin_attr,
	      char *buf, loff_t off, size_t count)
{
	struct pci_dev *pdev = to_pci_dev(container_of(kobj, struct device, kobj));

	if ((off ==  0) && (*buf == '0') && (count == 2))
		pdev->rom_attr_enabled = 0;
	else
		pdev->rom_attr_enabled = 1;

	return count;
}

/**
 * pci_read_rom - read a PCI ROM
 * @filp: sysfs file
 * @kobj: kernel object handle
 * @bin_attr: struct bin_attribute for this file
 * @buf: where to put the data we read from the ROM
 * @off: file offset
 * @count: number of bytes to read
 *
 * Put @count bytes starting at @off into @buf from the ROM in the PCI
 * device corresponding to @kobj.
 */
static ssize_t
pci_read_rom(struct file *filp, struct kobject *kobj,
	     struct bin_attribute *bin_attr,
	     char *buf, loff_t off, size_t count)
{
	struct pci_dev *pdev = to_pci_dev(container_of(kobj, struct device, kobj));
	void __iomem *rom;
	size_t size;

	if (!pdev->rom_attr_enabled)
		return -EINVAL;
	
	rom = pci_map_rom(pdev, &size);	/* size starts out as PCI window size */
	if (!rom || !size)
		return -EIO;
		
	if (off >= size)
		count = 0;
	else {
		if (off + count > size)
			count = size - off;
		
		memcpy_fromio(buf, rom + off, count);
	}
	pci_unmap_rom(pdev, rom);
		
	return count;
}

static struct bin_attribute pci_config_attr = {
	.attr =	{
		.name = "config",
		.mode = S_IRUGO | S_IWUSR,
	},
	.size = PCI_CFG_SPACE_SIZE,
	.read = pci_read_config,
	.write = pci_write_config,
};

static struct bin_attribute pcie_config_attr = {
	.attr =	{
		.name = "config",
		.mode = S_IRUGO | S_IWUSR,
	},
	.size = PCI_CFG_SPACE_EXP_SIZE,
	.read = pci_read_config,
	.write = pci_write_config,
};

int __attribute__ ((weak)) pcibios_add_platform_entries(struct pci_dev *dev)
{
	return 0;
}

static ssize_t reset_store(struct device *dev,
			   struct device_attribute *attr, const char *buf,
			   size_t count)
{
	struct pci_dev *pdev = to_pci_dev(dev);
	unsigned long val;
	ssize_t result = strict_strtoul(buf, 0, &val);

	if (result < 0)
		return result;

	if (val != 1)
		return -EINVAL;

	result = pci_reset_function(pdev);
	if (result < 0)
		return result;

	return count;
}

static struct device_attribute reset_attr = __ATTR(reset, 0200, NULL, reset_store);

static int pci_create_capabilities_sysfs(struct pci_dev *dev)
{
	int retval;
	struct bin_attribute *attr;

	/* If the device has VPD, try to expose it in sysfs. */
	if (dev->vpd) {
		attr = kzalloc(sizeof(*attr), GFP_ATOMIC);
		if (!attr)
			return -ENOMEM;

		sysfs_bin_attr_init(attr);
		attr->size = dev->vpd->len;
		attr->attr.name = "vpd";
		attr->attr.mode = S_IRUSR | S_IWUSR;
		attr->read = read_vpd_attr;
		attr->write = write_vpd_attr;
		retval = sysfs_create_bin_file(&dev->dev.kobj, attr);
		if (retval) {
			kfree(dev->vpd->attr);
			return retval;
		}
		dev->vpd->attr = attr;
	}

	/* Active State Power Management */
	pcie_aspm_create_sysfs_dev_files(dev);

	if (!pci_probe_reset_function(dev)) {
		retval = device_create_file(&dev->dev, &reset_attr);
		if (retval)
			goto error;
		dev->reset_fn = 1;
	}
	return 0;

error:
	pcie_aspm_remove_sysfs_dev_files(dev);
	if (dev->vpd && dev->vpd->attr) {
		sysfs_remove_bin_file(&dev->dev.kobj, dev->vpd->attr);
		kfree(dev->vpd->attr);
	}

	return retval;
}

int __must_check pci_create_sysfs_dev_files (struct pci_dev *pdev)
{
	int retval;
	int rom_size = 0;
	struct bin_attribute *attr;

	if (!sysfs_initialized)
		return -EACCES;

	if (pdev->cfg_size < PCI_CFG_SPACE_EXP_SIZE)
		retval = sysfs_create_bin_file(&pdev->dev.kobj, &pci_config_attr);
	else
		retval = sysfs_create_bin_file(&pdev->dev.kobj, &pcie_config_attr);
	if (retval)
		goto err;

	retval = pci_create_resource_files(pdev);
	if (retval)
		goto err_config_file;

	if (pci_resource_len(pdev, PCI_ROM_RESOURCE))
		rom_size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
	else if (pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW)
		rom_size = 0x20000;

	/* If the device has a ROM, try to expose it in sysfs. */
	if (rom_size) {
		attr = kzalloc(sizeof(*attr), GFP_ATOMIC);
		if (!attr) {
			retval = -ENOMEM;
			goto err_resource_files;
		}
		sysfs_bin_attr_init(attr);
		attr->size = rom_size;
		attr->attr.name = "rom";
		attr->attr.mode = S_IRUSR;
		attr->read = pci_read_rom;
		attr->write = pci_write_rom;
		retval = sysfs_create_bin_file(&pdev->dev.kobj, attr);
		if (retval) {
			kfree(attr);
			goto err_resource_files;
		}
		pdev->rom_attr = attr;
	}

	if ((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA) {
		retval = device_create_file(&pdev->dev, &vga_attr);
		if (retval)
			goto err_rom_file;
	}

	/* add platform-specific attributes */
	retval = pcibios_add_platform_entries(pdev);
	if (retval)
		goto err_vga_file;

	/* add sysfs entries for various capabilities */
	retval = pci_create_capabilities_sysfs(pdev);
	if (retval)
		goto err_vga_file;

	pci_create_firmware_label_files(pdev);

	return 0;

err_vga_file:
	if ((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA)
		device_remove_file(&pdev->dev, &vga_attr);
err_rom_file:
	if (rom_size) {
		sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
		kfree(pdev->rom_attr);
		pdev->rom_attr = NULL;
	}
err_resource_files:
	pci_remove_resource_files(pdev);
err_config_file:
	if (pdev->cfg_size < PCI_CFG_SPACE_EXP_SIZE)
		sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
	else
		sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);
err:
	return retval;
}

static void pci_remove_capabilities_sysfs(struct pci_dev *dev)
{
	if (dev->vpd && dev->vpd->attr) {
		sysfs_remove_bin_file(&dev->dev.kobj, dev->vpd->attr);
		kfree(dev->vpd->attr);
	}

	pcie_aspm_remove_sysfs_dev_files(dev);
	if (dev->reset_fn) {
		device_remove_file(&dev->dev, &reset_attr);
		dev->reset_fn = 0;
	}
}

/**
 * pci_remove_sysfs_dev_files - cleanup PCI specific sysfs files
 * @pdev: device whose entries we should free
 *
 * Cleanup when @pdev is removed from sysfs.
 */
void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
{
	int rom_size = 0;

	if (!sysfs_initialized)
		return;

	pci_remove_capabilities_sysfs(pdev);

	if (pdev->cfg_size < PCI_CFG_SPACE_EXP_SIZE)
		sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
	else
		sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);

	pci_remove_resource_files(pdev);

	if (pci_resource_len(pdev, PCI_ROM_RESOURCE))
		rom_size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
	else if (pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW)
		rom_size = 0x20000;

	if (rom_size && pdev->rom_attr) {
		sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
		kfree(pdev->rom_attr);
	}

	pci_remove_firmware_label_files(pdev);

}

static int __init pci_sysfs_init(void)
{
	struct pci_dev *pdev = NULL;
	int retval;

	sysfs_initialized = 1;
	for_each_pci_dev(pdev) {
		retval = pci_create_sysfs_dev_files(pdev);
		if (retval) {
			pci_dev_put(pdev);
			return retval;
		}
	}

	return 0;
}

late_initcall(pci_sysfs_init);