summaryrefslogtreecommitdiff
path: root/drivers/soc/qcom/smem.c
blob: d4a89d2bb43bb4090a4c0101d9c4298098cb344b (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015, Sony Mobile Communications AB.
 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
 */

#include <linux/hwspinlock.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/soc/qcom/smem.h>
#include <linux/soc/qcom/socinfo.h>

/*
 * The Qualcomm shared memory system is a allocate only heap structure that
 * consists of one of more memory areas that can be accessed by the processors
 * in the SoC.
 *
 * All systems contains a global heap, accessible by all processors in the SoC,
 * with a table of contents data structure (@smem_header) at the beginning of
 * the main shared memory block.
 *
 * The global header contains meta data for allocations as well as a fixed list
 * of 512 entries (@smem_global_entry) that can be initialized to reference
 * parts of the shared memory space.
 *
 *
 * In addition to this global heap a set of "private" heaps can be set up at
 * boot time with access restrictions so that only certain processor pairs can
 * access the data.
 *
 * These partitions are referenced from an optional partition table
 * (@smem_ptable), that is found 4kB from the end of the main smem region. The
 * partition table entries (@smem_ptable_entry) lists the involved processors
 * (or hosts) and their location in the main shared memory region.
 *
 * Each partition starts with a header (@smem_partition_header) that identifies
 * the partition and holds properties for the two internal memory regions. The
 * two regions are cached and non-cached memory respectively. Each region
 * contain a link list of allocation headers (@smem_private_entry) followed by
 * their data.
 *
 * Items in the non-cached region are allocated from the start of the partition
 * while items in the cached region are allocated from the end. The free area
 * is hence the region between the cached and non-cached offsets. The header of
 * cached items comes after the data.
 *
 * Version 12 (SMEM_GLOBAL_PART_VERSION) changes the item alloc/get procedure
 * for the global heap. A new global partition is created from the global heap
 * region with partition type (SMEM_GLOBAL_HOST) and the max smem item count is
 * set by the bootloader.
 *
 * To synchronize allocations in the shared memory heaps a remote spinlock must
 * be held - currently lock number 3 of the sfpb or tcsr is used for this on all
 * platforms.
 *
 */

/*
 * The version member of the smem header contains an array of versions for the
 * various software components in the SoC. We verify that the boot loader
 * version is a valid version as a sanity check.
 */
#define SMEM_MASTER_SBL_VERSION_INDEX	7
#define SMEM_GLOBAL_HEAP_VERSION	11
#define SMEM_GLOBAL_PART_VERSION	12

/*
 * The first 8 items are only to be allocated by the boot loader while
 * initializing the heap.
 */
#define SMEM_ITEM_LAST_FIXED	8

/* Highest accepted item number, for both global and private heaps */
#define SMEM_ITEM_COUNT		512

/* Processor/host identifier for the application processor */
#define SMEM_HOST_APPS		0

/* Processor/host identifier for the global partition */
#define SMEM_GLOBAL_HOST	0xfffe

/* Max number of processors/hosts in a system */
#define SMEM_HOST_COUNT		20

/**
  * struct smem_proc_comm - proc_comm communication struct (legacy)
  * @command:	current command to be executed
  * @status:	status of the currently requested command
  * @params:	parameters to the command
  */
struct smem_proc_comm {
	__le32 command;
	__le32 status;
	__le32 params[2];
};

/**
 * struct smem_global_entry - entry to reference smem items on the heap
 * @allocated:	boolean to indicate if this entry is used
 * @offset:	offset to the allocated space
 * @size:	size of the allocated space, 8 byte aligned
 * @aux_base:	base address for the memory region used by this unit, or 0 for
 *		the default region. bits 0,1 are reserved
 */
struct smem_global_entry {
	__le32 allocated;
	__le32 offset;
	__le32 size;
	__le32 aux_base; /* bits 1:0 reserved */
};
#define AUX_BASE_MASK		0xfffffffc

/**
 * struct smem_header - header found in beginning of primary smem region
 * @proc_comm:		proc_comm communication interface (legacy)
 * @version:		array of versions for the various subsystems
 * @initialized:	boolean to indicate that smem is initialized
 * @free_offset:	index of the first unallocated byte in smem
 * @available:		number of bytes available for allocation
 * @reserved:		reserved field, must be 0
 * @toc:		array of references to items
 */
struct smem_header {
	struct smem_proc_comm proc_comm[4];
	__le32 version[32];
	__le32 initialized;
	__le32 free_offset;
	__le32 available;
	__le32 reserved;
	struct smem_global_entry toc[SMEM_ITEM_COUNT];
};

/**
 * struct smem_ptable_entry - one entry in the @smem_ptable list
 * @offset:	offset, within the main shared memory region, of the partition
 * @size:	size of the partition
 * @flags:	flags for the partition (currently unused)
 * @host0:	first processor/host with access to this partition
 * @host1:	second processor/host with access to this partition
 * @cacheline:	alignment for "cached" entries
 * @reserved:	reserved entries for later use
 */
struct smem_ptable_entry {
	__le32 offset;
	__le32 size;
	__le32 flags;
	__le16 host0;
	__le16 host1;
	__le32 cacheline;
	__le32 reserved[7];
};

/**
 * struct smem_ptable - partition table for the private partitions
 * @magic:	magic number, must be SMEM_PTABLE_MAGIC
 * @version:	version of the partition table
 * @num_entries: number of partitions in the table
 * @reserved:	for now reserved entries
 * @entry:	list of @smem_ptable_entry for the @num_entries partitions
 */
struct smem_ptable {
	u8 magic[4];
	__le32 version;
	__le32 num_entries;
	__le32 reserved[5];
	struct smem_ptable_entry entry[];
};

static const u8 SMEM_PTABLE_MAGIC[] = { 0x24, 0x54, 0x4f, 0x43 }; /* "$TOC" */

/**
 * struct smem_partition_header - header of the partitions
 * @magic:	magic number, must be SMEM_PART_MAGIC
 * @host0:	first processor/host with access to this partition
 * @host1:	second processor/host with access to this partition
 * @size:	size of the partition
 * @offset_free_uncached: offset to the first free byte of uncached memory in
 *		this partition
 * @offset_free_cached: offset to the first free byte of cached memory in this
 *		partition
 * @reserved:	for now reserved entries
 */
struct smem_partition_header {
	u8 magic[4];
	__le16 host0;
	__le16 host1;
	__le32 size;
	__le32 offset_free_uncached;
	__le32 offset_free_cached;
	__le32 reserved[3];
};

/**
 * struct smem_partition - describes smem partition
 * @virt_base:	starting virtual address of partition
 * @phys_base:	starting physical address of partition
 * @cacheline:	alignment for "cached" entries
 * @size:	size of partition
 */
struct smem_partition {
	void __iomem *virt_base;
	phys_addr_t phys_base;
	size_t cacheline;
	size_t size;
};

static const u8 SMEM_PART_MAGIC[] = { 0x24, 0x50, 0x52, 0x54 };

/**
 * struct smem_private_entry - header of each item in the private partition
 * @canary:	magic number, must be SMEM_PRIVATE_CANARY
 * @item:	identifying number of the smem item
 * @size:	size of the data, including padding bytes
 * @padding_data: number of bytes of padding of data
 * @padding_hdr: number of bytes of padding between the header and the data
 * @reserved:	for now reserved entry
 */
struct smem_private_entry {
	u16 canary; /* bytes are the same so no swapping needed */
	__le16 item;
	__le32 size; /* includes padding bytes */
	__le16 padding_data;
	__le16 padding_hdr;
	__le32 reserved;
};
#define SMEM_PRIVATE_CANARY	0xa5a5

/**
 * struct smem_info - smem region info located after the table of contents
 * @magic:	magic number, must be SMEM_INFO_MAGIC
 * @size:	size of the smem region
 * @base_addr:	base address of the smem region
 * @reserved:	for now reserved entry
 * @num_items:	highest accepted item number
 */
struct smem_info {
	u8 magic[4];
	__le32 size;
	__le32 base_addr;
	__le32 reserved;
	__le16 num_items;
};

static const u8 SMEM_INFO_MAGIC[] = { 0x53, 0x49, 0x49, 0x49 }; /* SIII */

/**
 * struct smem_region - representation of a chunk of memory used for smem
 * @aux_base:	identifier of aux_mem base
 * @virt_base:	virtual base address of memory with this aux_mem identifier
 * @size:	size of the memory region
 */
struct smem_region {
	phys_addr_t aux_base;
	void __iomem *virt_base;
	size_t size;
};

/**
 * struct qcom_smem - device data for the smem device
 * @dev:	device pointer
 * @hwlock:	reference to a hwspinlock
 * @ptable: virtual base of partition table
 * @global_partition: describes for global partition when in use
 * @partitions: list of partitions of current processor/host
 * @item_count: max accepted item number
 * @socinfo:	platform device pointer
 * @num_regions: number of @regions
 * @regions:	list of the memory regions defining the shared memory
 */
struct qcom_smem {
	struct device *dev;

	struct hwspinlock *hwlock;

	u32 item_count;
	struct platform_device *socinfo;
	struct smem_ptable *ptable;
	struct smem_partition global_partition;
	struct smem_partition partitions[SMEM_HOST_COUNT];

	unsigned num_regions;
	struct smem_region regions[];
};

static void *
phdr_to_last_uncached_entry(struct smem_partition_header *phdr)
{
	void *p = phdr;

	return p + le32_to_cpu(phdr->offset_free_uncached);
}

static struct smem_private_entry *
phdr_to_first_cached_entry(struct smem_partition_header *phdr,
					size_t cacheline)
{
	void *p = phdr;
	struct smem_private_entry *e;

	return p + le32_to_cpu(phdr->size) - ALIGN(sizeof(*e), cacheline);
}

static void *
phdr_to_last_cached_entry(struct smem_partition_header *phdr)
{
	void *p = phdr;

	return p + le32_to_cpu(phdr->offset_free_cached);
}

static struct smem_private_entry *
phdr_to_first_uncached_entry(struct smem_partition_header *phdr)
{
	void *p = phdr;

	return p + sizeof(*phdr);
}

static struct smem_private_entry *
uncached_entry_next(struct smem_private_entry *e)
{
	void *p = e;

	return p + sizeof(*e) + le16_to_cpu(e->padding_hdr) +
	       le32_to_cpu(e->size);
}

static struct smem_private_entry *
cached_entry_next(struct smem_private_entry *e, size_t cacheline)
{
	void *p = e;

	return p - le32_to_cpu(e->size) - ALIGN(sizeof(*e), cacheline);
}

static void *uncached_entry_to_item(struct smem_private_entry *e)
{
	void *p = e;

	return p + sizeof(*e) + le16_to_cpu(e->padding_hdr);
}

static void *cached_entry_to_item(struct smem_private_entry *e)
{
	void *p = e;

	return p - le32_to_cpu(e->size);
}

/* Pointer to the one and only smem handle */
static struct qcom_smem *__smem;

/* Timeout (ms) for the trylock of remote spinlocks */
#define HWSPINLOCK_TIMEOUT	1000

/**
 * qcom_smem_is_available() - Check if SMEM is available
 *
 * Return: true if SMEM is available, false otherwise.
 */
bool qcom_smem_is_available(void)
{
	return !!__smem;
}
EXPORT_SYMBOL(qcom_smem_is_available);

static int qcom_smem_alloc_private(struct qcom_smem *smem,
				   struct smem_partition *part,
				   unsigned item,
				   size_t size)
{
	struct smem_private_entry *hdr, *end;
	struct smem_partition_header *phdr;
	size_t alloc_size;
	void *cached;
	void *p_end;

	phdr = (struct smem_partition_header __force *)part->virt_base;
	p_end = (void *)phdr + part->size;

	hdr = phdr_to_first_uncached_entry(phdr);
	end = phdr_to_last_uncached_entry(phdr);
	cached = phdr_to_last_cached_entry(phdr);

	if (WARN_ON((void *)end > p_end || cached > p_end))
		return -EINVAL;

	while (hdr < end) {
		if (hdr->canary != SMEM_PRIVATE_CANARY)
			goto bad_canary;
		if (le16_to_cpu(hdr->item) == item)
			return -EEXIST;

		hdr = uncached_entry_next(hdr);
	}

	if (WARN_ON((void *)hdr > p_end))
		return -EINVAL;

	/* Check that we don't grow into the cached region */
	alloc_size = sizeof(*hdr) + ALIGN(size, 8);
	if ((void *)hdr + alloc_size > cached) {
		dev_err(smem->dev, "Out of memory\n");
		return -ENOSPC;
	}

	hdr->canary = SMEM_PRIVATE_CANARY;
	hdr->item = cpu_to_le16(item);
	hdr->size = cpu_to_le32(ALIGN(size, 8));
	hdr->padding_data = cpu_to_le16(le32_to_cpu(hdr->size) - size);
	hdr->padding_hdr = 0;

	/*
	 * Ensure the header is written before we advance the free offset, so
	 * that remote processors that does not take the remote spinlock still
	 * gets a consistent view of the linked list.
	 */
	wmb();
	le32_add_cpu(&phdr->offset_free_uncached, alloc_size);

	return 0;
bad_canary:
	dev_err(smem->dev, "Found invalid canary in hosts %hu:%hu partition\n",
		le16_to_cpu(phdr->host0), le16_to_cpu(phdr->host1));

	return -EINVAL;
}

static int qcom_smem_alloc_global(struct qcom_smem *smem,
				  unsigned item,
				  size_t size)
{
	struct smem_global_entry *entry;
	struct smem_header *header;

	header = smem->regions[0].virt_base;
	entry = &header->toc[item];
	if (entry->allocated)
		return -EEXIST;

	size = ALIGN(size, 8);
	if (WARN_ON(size > le32_to_cpu(header->available)))
		return -ENOMEM;

	entry->offset = header->free_offset;
	entry->size = cpu_to_le32(size);

	/*
	 * Ensure the header is consistent before we mark the item allocated,
	 * so that remote processors will get a consistent view of the item
	 * even though they do not take the spinlock on read.
	 */
	wmb();
	entry->allocated = cpu_to_le32(1);

	le32_add_cpu(&header->free_offset, size);
	le32_add_cpu(&header->available, -size);

	return 0;
}

/**
 * qcom_smem_alloc() - allocate space for a smem item
 * @host:	remote processor id, or -1
 * @item:	smem item handle
 * @size:	number of bytes to be allocated
 *
 * Allocate space for a given smem item of size @size, given that the item is
 * not yet allocated.
 */
int qcom_smem_alloc(unsigned host, unsigned item, size_t size)
{
	struct smem_partition *part;
	unsigned long flags;
	int ret;

	if (!__smem)
		return -EPROBE_DEFER;

	if (item < SMEM_ITEM_LAST_FIXED) {
		dev_err(__smem->dev,
			"Rejecting allocation of static entry %d\n", item);
		return -EINVAL;
	}

	if (WARN_ON(item >= __smem->item_count))
		return -EINVAL;

	ret = hwspin_lock_timeout_irqsave(__smem->hwlock,
					  HWSPINLOCK_TIMEOUT,
					  &flags);
	if (ret)
		return ret;

	if (host < SMEM_HOST_COUNT && __smem->partitions[host].virt_base) {
		part = &__smem->partitions[host];
		ret = qcom_smem_alloc_private(__smem, part, item, size);
	} else if (__smem->global_partition.virt_base) {
		part = &__smem->global_partition;
		ret = qcom_smem_alloc_private(__smem, part, item, size);
	} else {
		ret = qcom_smem_alloc_global(__smem, item, size);
	}

	hwspin_unlock_irqrestore(__smem->hwlock, &flags);

	return ret;
}
EXPORT_SYMBOL_GPL(qcom_smem_alloc);

static void *qcom_smem_get_global(struct qcom_smem *smem,
				  unsigned item,
				  size_t *size)
{
	struct smem_header *header;
	struct smem_region *region;
	struct smem_global_entry *entry;
	u64 entry_offset;
	u32 e_size;
	u32 aux_base;
	unsigned i;

	header = smem->regions[0].virt_base;
	entry = &header->toc[item];
	if (!entry->allocated)
		return ERR_PTR(-ENXIO);

	aux_base = le32_to_cpu(entry->aux_base) & AUX_BASE_MASK;

	for (i = 0; i < smem->num_regions; i++) {
		region = &smem->regions[i];

		if ((u32)region->aux_base == aux_base || !aux_base) {
			e_size = le32_to_cpu(entry->size);
			entry_offset = le32_to_cpu(entry->offset);

			if (WARN_ON(e_size + entry_offset > region->size))
				return ERR_PTR(-EINVAL);

			if (size != NULL)
				*size = e_size;

			return region->virt_base + entry_offset;
		}
	}

	return ERR_PTR(-ENOENT);
}

static void *qcom_smem_get_private(struct qcom_smem *smem,
				   struct smem_partition *part,
				   unsigned item,
				   size_t *size)
{
	struct smem_private_entry *e, *end;
	struct smem_partition_header *phdr;
	void *item_ptr, *p_end;
	u32 padding_data;
	u32 e_size;

	phdr = (struct smem_partition_header __force *)part->virt_base;
	p_end = (void *)phdr + part->size;

	e = phdr_to_first_uncached_entry(phdr);
	end = phdr_to_last_uncached_entry(phdr);

	while (e < end) {
		if (e->canary != SMEM_PRIVATE_CANARY)
			goto invalid_canary;

		if (le16_to_cpu(e->item) == item) {
			if (size != NULL) {
				e_size = le32_to_cpu(e->size);
				padding_data = le16_to_cpu(e->padding_data);

				if (WARN_ON(e_size > part->size || padding_data > e_size))
					return ERR_PTR(-EINVAL);

				*size = e_size - padding_data;
			}

			item_ptr = uncached_entry_to_item(e);
			if (WARN_ON(item_ptr > p_end))
				return ERR_PTR(-EINVAL);

			return item_ptr;
		}

		e = uncached_entry_next(e);
	}

	if (WARN_ON((void *)e > p_end))
		return ERR_PTR(-EINVAL);

	/* Item was not found in the uncached list, search the cached list */

	e = phdr_to_first_cached_entry(phdr, part->cacheline);
	end = phdr_to_last_cached_entry(phdr);

	if (WARN_ON((void *)e < (void *)phdr || (void *)end > p_end))
		return ERR_PTR(-EINVAL);

	while (e > end) {
		if (e->canary != SMEM_PRIVATE_CANARY)
			goto invalid_canary;

		if (le16_to_cpu(e->item) == item) {
			if (size != NULL) {
				e_size = le32_to_cpu(e->size);
				padding_data = le16_to_cpu(e->padding_data);

				if (WARN_ON(e_size > part->size || padding_data > e_size))
					return ERR_PTR(-EINVAL);

				*size = e_size - padding_data;
			}

			item_ptr = cached_entry_to_item(e);
			if (WARN_ON(item_ptr < (void *)phdr))
				return ERR_PTR(-EINVAL);

			return item_ptr;
		}

		e = cached_entry_next(e, part->cacheline);
	}

	if (WARN_ON((void *)e < (void *)phdr))
		return ERR_PTR(-EINVAL);

	return ERR_PTR(-ENOENT);

invalid_canary:
	dev_err(smem->dev, "Found invalid canary in hosts %hu:%hu partition\n",
			le16_to_cpu(phdr->host0), le16_to_cpu(phdr->host1));

	return ERR_PTR(-EINVAL);
}

/**
 * qcom_smem_get() - resolve ptr of size of a smem item
 * @host:	the remote processor, or -1
 * @item:	smem item handle
 * @size:	pointer to be filled out with size of the item
 *
 * Looks up smem item and returns pointer to it. Size of smem
 * item is returned in @size.
 */
void *qcom_smem_get(unsigned host, unsigned item, size_t *size)
{
	struct smem_partition *part;
	unsigned long flags;
	int ret;
	void *ptr = ERR_PTR(-EPROBE_DEFER);

	if (!__smem)
		return ptr;

	if (WARN_ON(item >= __smem->item_count))
		return ERR_PTR(-EINVAL);

	ret = hwspin_lock_timeout_irqsave(__smem->hwlock,
					  HWSPINLOCK_TIMEOUT,
					  &flags);
	if (ret)
		return ERR_PTR(ret);

	if (host < SMEM_HOST_COUNT && __smem->partitions[host].virt_base) {
		part = &__smem->partitions[host];
		ptr = qcom_smem_get_private(__smem, part, item, size);
	} else if (__smem->global_partition.virt_base) {
		part = &__smem->global_partition;
		ptr = qcom_smem_get_private(__smem, part, item, size);
	} else {
		ptr = qcom_smem_get_global(__smem, item, size);
	}

	hwspin_unlock_irqrestore(__smem->hwlock, &flags);

	return ptr;

}
EXPORT_SYMBOL_GPL(qcom_smem_get);

/**
 * qcom_smem_get_free_space() - retrieve amount of free space in a partition
 * @host:	the remote processor identifying a partition, or -1
 *
 * To be used by smem clients as a quick way to determine if any new
 * allocations has been made.
 */
int qcom_smem_get_free_space(unsigned host)
{
	struct smem_partition *part;
	struct smem_partition_header *phdr;
	struct smem_header *header;
	unsigned ret;

	if (!__smem)
		return -EPROBE_DEFER;

	if (host < SMEM_HOST_COUNT && __smem->partitions[host].virt_base) {
		part = &__smem->partitions[host];
		phdr = part->virt_base;
		ret = le32_to_cpu(phdr->offset_free_cached) -
		      le32_to_cpu(phdr->offset_free_uncached);

		if (ret > le32_to_cpu(part->size))
			return -EINVAL;
	} else if (__smem->global_partition.virt_base) {
		part = &__smem->global_partition;
		phdr = part->virt_base;
		ret = le32_to_cpu(phdr->offset_free_cached) -
		      le32_to_cpu(phdr->offset_free_uncached);

		if (ret > le32_to_cpu(part->size))
			return -EINVAL;
	} else {
		header = __smem->regions[0].virt_base;
		ret = le32_to_cpu(header->available);

		if (ret > __smem->regions[0].size)
			return -EINVAL;
	}

	return ret;
}
EXPORT_SYMBOL_GPL(qcom_smem_get_free_space);

static bool addr_in_range(void __iomem *base, size_t size, void *addr)
{
	return base && ((void __iomem *)addr >= base && (void __iomem *)addr < base + size);
}

/**
 * qcom_smem_virt_to_phys() - return the physical address associated
 * with an smem item pointer (previously returned by qcom_smem_get()
 * @p:	the virtual address to convert
 *
 * Returns 0 if the pointer provided is not within any smem region.
 */
phys_addr_t qcom_smem_virt_to_phys(void *p)
{
	struct smem_partition *part;
	struct smem_region *area;
	u64 offset;
	u32 i;

	for (i = 0; i < SMEM_HOST_COUNT; i++) {
		part = &__smem->partitions[i];

		if (addr_in_range(part->virt_base, part->size, p)) {
			offset = p - part->virt_base;

			return (phys_addr_t)part->phys_base + offset;
		}
	}

	part = &__smem->global_partition;

	if (addr_in_range(part->virt_base, part->size, p)) {
		offset = p - part->virt_base;

		return (phys_addr_t)part->phys_base + offset;
	}

	for (i = 0; i < __smem->num_regions; i++) {
		area = &__smem->regions[i];

		if (addr_in_range(area->virt_base, area->size, p)) {
			offset = p - area->virt_base;

			return (phys_addr_t)area->aux_base + offset;
		}
	}

	return 0;
}
EXPORT_SYMBOL_GPL(qcom_smem_virt_to_phys);

/**
 * qcom_smem_get_soc_id() - return the SoC ID
 * @id:	On success, we return the SoC ID here.
 *
 * Look up SoC ID from HW/SW build ID and return it.
 *
 * Return: 0 on success, negative errno on failure.
 */
int qcom_smem_get_soc_id(u32 *id)
{
	struct socinfo *info;

	info = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_HW_SW_BUILD_ID, NULL);
	if (IS_ERR(info))
		return PTR_ERR(info);

	*id = __le32_to_cpu(info->id);

	return 0;
}
EXPORT_SYMBOL_GPL(qcom_smem_get_soc_id);

static int qcom_smem_get_sbl_version(struct qcom_smem *smem)
{
	struct smem_header *header;
	__le32 *versions;

	header = smem->regions[0].virt_base;
	versions = header->version;

	return le32_to_cpu(versions[SMEM_MASTER_SBL_VERSION_INDEX]);
}

static struct smem_ptable *qcom_smem_get_ptable(struct qcom_smem *smem)
{
	struct smem_ptable *ptable;
	u32 version;

	ptable = smem->ptable;
	if (memcmp(ptable->magic, SMEM_PTABLE_MAGIC, sizeof(ptable->magic)))
		return ERR_PTR(-ENOENT);

	version = le32_to_cpu(ptable->version);
	if (version != 1) {
		dev_err(smem->dev,
			"Unsupported partition header version %d\n", version);
		return ERR_PTR(-EINVAL);
	}
	return ptable;
}

static u32 qcom_smem_get_item_count(struct qcom_smem *smem)
{
	struct smem_ptable *ptable;
	struct smem_info *info;

	ptable = qcom_smem_get_ptable(smem);
	if (IS_ERR_OR_NULL(ptable))
		return SMEM_ITEM_COUNT;

	info = (struct smem_info *)&ptable->entry[ptable->num_entries];
	if (memcmp(info->magic, SMEM_INFO_MAGIC, sizeof(info->magic)))
		return SMEM_ITEM_COUNT;

	return le16_to_cpu(info->num_items);
}

/*
 * Validate the partition header for a partition whose partition
 * table entry is supplied.  Returns a pointer to its header if
 * valid, or a null pointer otherwise.
 */
static struct smem_partition_header *
qcom_smem_partition_header(struct qcom_smem *smem,
		struct smem_ptable_entry *entry, u16 host0, u16 host1)
{
	struct smem_partition_header *header;
	u32 phys_addr;
	u32 size;

	phys_addr = smem->regions[0].aux_base + le32_to_cpu(entry->offset);
	header = devm_ioremap_wc(smem->dev, phys_addr, le32_to_cpu(entry->size));

	if (!header)
		return NULL;

	if (memcmp(header->magic, SMEM_PART_MAGIC, sizeof(header->magic))) {
		dev_err(smem->dev, "bad partition magic %4ph\n", header->magic);
		return NULL;
	}

	if (host0 != le16_to_cpu(header->host0)) {
		dev_err(smem->dev, "bad host0 (%hu != %hu)\n",
				host0, le16_to_cpu(header->host0));
		return NULL;
	}
	if (host1 != le16_to_cpu(header->host1)) {
		dev_err(smem->dev, "bad host1 (%hu != %hu)\n",
				host1, le16_to_cpu(header->host1));
		return NULL;
	}

	size = le32_to_cpu(header->size);
	if (size != le32_to_cpu(entry->size)) {
		dev_err(smem->dev, "bad partition size (%u != %u)\n",
			size, le32_to_cpu(entry->size));
		return NULL;
	}

	if (le32_to_cpu(header->offset_free_uncached) > size) {
		dev_err(smem->dev, "bad partition free uncached (%u > %u)\n",
			le32_to_cpu(header->offset_free_uncached), size);
		return NULL;
	}

	return header;
}

static int qcom_smem_set_global_partition(struct qcom_smem *smem)
{
	struct smem_partition_header *header;
	struct smem_ptable_entry *entry;
	struct smem_ptable *ptable;
	bool found = false;
	int i;

	if (smem->global_partition.virt_base) {
		dev_err(smem->dev, "Already found the global partition\n");
		return -EINVAL;
	}

	ptable = qcom_smem_get_ptable(smem);
	if (IS_ERR(ptable))
		return PTR_ERR(ptable);

	for (i = 0; i < le32_to_cpu(ptable->num_entries); i++) {
		entry = &ptable->entry[i];
		if (!le32_to_cpu(entry->offset))
			continue;
		if (!le32_to_cpu(entry->size))
			continue;

		if (le16_to_cpu(entry->host0) != SMEM_GLOBAL_HOST)
			continue;

		if (le16_to_cpu(entry->host1) == SMEM_GLOBAL_HOST) {
			found = true;
			break;
		}
	}

	if (!found) {
		dev_err(smem->dev, "Missing entry for global partition\n");
		return -EINVAL;
	}

	header = qcom_smem_partition_header(smem, entry,
				SMEM_GLOBAL_HOST, SMEM_GLOBAL_HOST);
	if (!header)
		return -EINVAL;

	smem->global_partition.virt_base = (void __iomem *)header;
	smem->global_partition.phys_base = smem->regions[0].aux_base +
								le32_to_cpu(entry->offset);
	smem->global_partition.size = le32_to_cpu(entry->size);
	smem->global_partition.cacheline = le32_to_cpu(entry->cacheline);

	return 0;
}

static int
qcom_smem_enumerate_partitions(struct qcom_smem *smem, u16 local_host)
{
	struct smem_partition_header *header;
	struct smem_ptable_entry *entry;
	struct smem_ptable *ptable;
	u16 remote_host;
	u16 host0, host1;
	int i;

	ptable = qcom_smem_get_ptable(smem);
	if (IS_ERR(ptable))
		return PTR_ERR(ptable);

	for (i = 0; i < le32_to_cpu(ptable->num_entries); i++) {
		entry = &ptable->entry[i];
		if (!le32_to_cpu(entry->offset))
			continue;
		if (!le32_to_cpu(entry->size))
			continue;

		host0 = le16_to_cpu(entry->host0);
		host1 = le16_to_cpu(entry->host1);
		if (host0 == local_host)
			remote_host = host1;
		else if (host1 == local_host)
			remote_host = host0;
		else
			continue;

		if (remote_host >= SMEM_HOST_COUNT) {
			dev_err(smem->dev, "bad host %u\n", remote_host);
			return -EINVAL;
		}

		if (smem->partitions[remote_host].virt_base) {
			dev_err(smem->dev, "duplicate host %u\n", remote_host);
			return -EINVAL;
		}

		header = qcom_smem_partition_header(smem, entry, host0, host1);
		if (!header)
			return -EINVAL;

		smem->partitions[remote_host].virt_base = (void __iomem *)header;
		smem->partitions[remote_host].phys_base = smem->regions[0].aux_base +
										le32_to_cpu(entry->offset);
		smem->partitions[remote_host].size = le32_to_cpu(entry->size);
		smem->partitions[remote_host].cacheline = le32_to_cpu(entry->cacheline);
	}

	return 0;
}

static int qcom_smem_map_toc(struct qcom_smem *smem, struct smem_region *region)
{
	u32 ptable_start;

	/* map starting 4K for smem header */
	region->virt_base = devm_ioremap_wc(smem->dev, region->aux_base, SZ_4K);
	ptable_start = region->aux_base + region->size - SZ_4K;
	/* map last 4k for toc */
	smem->ptable = devm_ioremap_wc(smem->dev, ptable_start, SZ_4K);

	if (!region->virt_base || !smem->ptable)
		return -ENOMEM;

	return 0;
}

static int qcom_smem_map_global(struct qcom_smem *smem, u32 size)
{
	u32 phys_addr;

	phys_addr = smem->regions[0].aux_base;

	smem->regions[0].size = size;
	smem->regions[0].virt_base = devm_ioremap_wc(smem->dev, phys_addr, size);

	if (!smem->regions[0].virt_base)
		return -ENOMEM;

	return 0;
}

static int qcom_smem_resolve_mem(struct qcom_smem *smem, const char *name,
				 struct smem_region *region)
{
	struct device *dev = smem->dev;
	struct device_node *np;
	struct resource r;
	int ret;

	np = of_parse_phandle(dev->of_node, name, 0);
	if (!np) {
		dev_err(dev, "No %s specified\n", name);
		return -EINVAL;
	}

	ret = of_address_to_resource(np, 0, &r);
	of_node_put(np);
	if (ret)
		return ret;

	region->aux_base = r.start;
	region->size = resource_size(&r);

	return 0;
}

static int qcom_smem_probe(struct platform_device *pdev)
{
	struct smem_header *header;
	struct reserved_mem *rmem;
	struct qcom_smem *smem;
	unsigned long flags;
	int num_regions;
	int hwlock_id;
	u32 version;
	u32 size;
	int ret;
	int i;

	num_regions = 1;
	if (of_property_present(pdev->dev.of_node, "qcom,rpm-msg-ram"))
		num_regions++;

	smem = devm_kzalloc(&pdev->dev, struct_size(smem, regions, num_regions),
			    GFP_KERNEL);
	if (!smem)
		return -ENOMEM;

	smem->dev = &pdev->dev;
	smem->num_regions = num_regions;

	rmem = of_reserved_mem_lookup(pdev->dev.of_node);
	if (rmem) {
		smem->regions[0].aux_base = rmem->base;
		smem->regions[0].size = rmem->size;
	} else {
		/*
		 * Fall back to the memory-region reference, if we're not a
		 * reserved-memory node.
		 */
		ret = qcom_smem_resolve_mem(smem, "memory-region", &smem->regions[0]);
		if (ret)
			return ret;
	}

	if (num_regions > 1) {
		ret = qcom_smem_resolve_mem(smem, "qcom,rpm-msg-ram", &smem->regions[1]);
		if (ret)
			return ret;
	}


	ret = qcom_smem_map_toc(smem, &smem->regions[0]);
	if (ret)
		return ret;

	for (i = 1; i < num_regions; i++) {
		smem->regions[i].virt_base = devm_ioremap_wc(&pdev->dev,
							     smem->regions[i].aux_base,
							     smem->regions[i].size);
		if (!smem->regions[i].virt_base) {
			dev_err(&pdev->dev, "failed to remap %pa\n", &smem->regions[i].aux_base);
			return -ENOMEM;
		}
	}

	header = smem->regions[0].virt_base;
	if (le32_to_cpu(header->initialized) != 1 ||
	    le32_to_cpu(header->reserved)) {
		dev_err(&pdev->dev, "SMEM is not initialized by SBL\n");
		return -EINVAL;
	}

	hwlock_id = of_hwspin_lock_get_id(pdev->dev.of_node, 0);
	if (hwlock_id < 0) {
		if (hwlock_id != -EPROBE_DEFER)
			dev_err(&pdev->dev, "failed to retrieve hwlock\n");
		return hwlock_id;
	}

	smem->hwlock = hwspin_lock_request_specific(hwlock_id);
	if (!smem->hwlock)
		return -ENXIO;

	ret = hwspin_lock_timeout_irqsave(smem->hwlock, HWSPINLOCK_TIMEOUT, &flags);
	if (ret)
		return ret;
	size = readl_relaxed(&header->available) + readl_relaxed(&header->free_offset);
	hwspin_unlock_irqrestore(smem->hwlock, &flags);

	version = qcom_smem_get_sbl_version(smem);
	/*
	 * smem header mapping is required only in heap version scheme, so unmap
	 * it here. It will be remapped in qcom_smem_map_global() when whole
	 * partition is mapped again.
	 */
	devm_iounmap(smem->dev, smem->regions[0].virt_base);
	switch (version >> 16) {
	case SMEM_GLOBAL_PART_VERSION:
		ret = qcom_smem_set_global_partition(smem);
		if (ret < 0)
			return ret;
		smem->item_count = qcom_smem_get_item_count(smem);
		break;
	case SMEM_GLOBAL_HEAP_VERSION:
		qcom_smem_map_global(smem, size);
		smem->item_count = SMEM_ITEM_COUNT;
		break;
	default:
		dev_err(&pdev->dev, "Unsupported SMEM version 0x%x\n", version);
		return -EINVAL;
	}

	BUILD_BUG_ON(SMEM_HOST_APPS >= SMEM_HOST_COUNT);
	ret = qcom_smem_enumerate_partitions(smem, SMEM_HOST_APPS);
	if (ret < 0 && ret != -ENOENT)
		return ret;

	__smem = smem;

	smem->socinfo = platform_device_register_data(&pdev->dev, "qcom-socinfo",
						      PLATFORM_DEVID_NONE, NULL,
						      0);
	if (IS_ERR(smem->socinfo))
		dev_dbg(&pdev->dev, "failed to register socinfo device\n");

	return 0;
}

static int qcom_smem_remove(struct platform_device *pdev)
{
	platform_device_unregister(__smem->socinfo);

	hwspin_lock_free(__smem->hwlock);
	__smem = NULL;

	return 0;
}

static const struct of_device_id qcom_smem_of_match[] = {
	{ .compatible = "qcom,smem" },
	{}
};
MODULE_DEVICE_TABLE(of, qcom_smem_of_match);

static struct platform_driver qcom_smem_driver = {
	.probe = qcom_smem_probe,
	.remove = qcom_smem_remove,
	.driver  = {
		.name = "qcom-smem",
		.of_match_table = qcom_smem_of_match,
		.suppress_bind_attrs = true,
	},
};

static int __init qcom_smem_init(void)
{
	return platform_driver_register(&qcom_smem_driver);
}
arch_initcall(qcom_smem_init);

static void __exit qcom_smem_exit(void)
{
	platform_driver_unregister(&qcom_smem_driver);
}
module_exit(qcom_smem_exit)

MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
MODULE_DESCRIPTION("Qualcomm Shared Memory Manager");
MODULE_LICENSE("GPL v2");