Loading...
   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
/*
 * Copyright (c) 2007-2021 Apple Inc. All rights reserved.
 * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/*
 * @APPLE_FREE_COPYRIGHT@
 */
/*
 *	File:		arm/commpage/commpage.c
 *	Purpose:	Set up and export a RO/RW page
 */
#include <libkern/section_keywords.h>
#include <mach/mach_types.h>
#include <mach/machine.h>
#include <mach/vm_map.h>
#include <machine/cpu_capabilities.h>
#include <machine/commpage.h>
#include <machine/config.h>
#include <machine/pmap.h>
#include <vm/vm_kern.h>
#include <vm/vm_map.h>
#include <vm/vm_protos.h>
#include <ipc/ipc_port.h>
#include <arm/cpuid.h>          /* for cpuid_info() & cache_info() */
#include <arm/cpu_capabilities_public.h>
#include <arm/misc_protos.h>
#include <arm/rtclock.h>
#include <libkern/OSAtomic.h>
#include <stdatomic.h>
#include <kern/remote_time.h>
#include <kern/smr.h>
#include <machine/atomic.h>
#include <machine/machine_remote_time.h>
#include <machine/machine_routines.h>

#include <sys/kdebug.h>
#include <sys/random.h>

#if CONFIG_ATM
#include <atm/atm_internal.h>
#endif

static int commpage_cpus( void );


static void commpage_init_cpu_capabilities( void );

SECURITY_READ_ONLY_LATE(vm_address_t)   commPagePtr = 0;
SECURITY_READ_ONLY_LATE(vm_address_t)   commpage_rw_addr = 0;
SECURITY_READ_ONLY_LATE(vm_address_t)   commpage_kernel_ro_addr = 0;
SECURITY_READ_ONLY_LATE(uint64_t)       _cpu_capabilities = 0;
SECURITY_READ_ONLY_LATE(vm_address_t)   commpage_rw_text_addr = 0;

extern user64_addr_t commpage_text64_location;
extern user32_addr_t commpage_text32_location;

/* For sysctl access from BSD side */
extern int gARMv8Crc32;
extern int gARMv8Gpi;
extern int gARM_FEAT_FlagM;
extern int gARM_FEAT_FlagM2;
extern int gARM_FEAT_FHM;
extern int gARM_FEAT_DotProd;
extern int gARM_FEAT_SHA3;
extern int gARM_FEAT_RDM;
extern int gARM_FEAT_LSE;
extern int gARM_FEAT_SHA256;
extern int gARM_FEAT_SHA512;
extern int gARM_FEAT_SHA1;
extern int gARM_FEAT_AES;
extern int gARM_FEAT_PMULL;
extern int gARM_FEAT_SPECRES;
extern int gARM_FEAT_SB;
extern int gARM_FEAT_FRINTTS;
extern int gARM_FEAT_LRCPC;
extern int gARM_FEAT_LRCPC2;
extern int gARM_FEAT_FCMA;
extern int gARM_FEAT_JSCVT;
extern int gARM_FEAT_PAuth;
extern int gARM_FEAT_PAuth2;
extern int gARM_FEAT_FPAC;
extern int gARM_FEAT_FPACCOMBINE;
extern int gARM_FEAT_DPB;
extern int gARM_FEAT_DPB2;
extern int gARM_FEAT_BF16;
extern int gARM_FEAT_I8MM;
extern int gARM_FEAT_WFxT;
extern int gARM_FEAT_RPRES;
extern int gARM_FEAT_ECV;
extern int gARM_FEAT_LSE2;
extern int gARM_FEAT_CSV2;
extern int gARM_FEAT_CSV3;
extern int gARM_FEAT_DIT;
extern int gARM_AdvSIMD;
extern int gARM_AdvSIMD_HPFPCvt;
extern int gARM_FEAT_FP16;
extern int gARM_FEAT_SSBS;
extern int gARM_FEAT_BTI;
extern int gARM_FP_SyncExceptions;
extern int gARM_FEAT_SME;
extern int gARM_FEAT_SME2;
extern int gARM_SME_F32F32;
extern int gARM_SME_BI32I32;
extern int gARM_SME_B16F32;
extern int gARM_SME_F16F32;
extern int gARM_SME_I8I32;
extern int gARM_SME_I16I32;
extern int gARM_FEAT_SME_F64F64;
extern int gARM_FEAT_SME_I16I64;
extern int gARM_FEAT_AFP;

extern int      gUCNormalMem;

void
commpage_populate(void)
{
	uint16_t        c2;
	int cpufamily;

	// Create the data and the text commpage
	vm_map_address_t kernel_data_addr, kernel_text_addr, kernel_ro_data_addr, user_text_addr;
	pmap_create_commpages(&kernel_data_addr, &kernel_text_addr, &kernel_ro_data_addr, &user_text_addr);

	commpage_rw_addr = kernel_data_addr;
	commpage_rw_text_addr = kernel_text_addr;
	commpage_kernel_ro_addr = kernel_ro_data_addr;
	commPagePtr = (vm_address_t) _COMM_PAGE_BASE_ADDRESS;

#if __arm64__
	commpage_text64_location = user_text_addr;
	bcopy(_COMM_PAGE64_SIGNATURE_STRING, (void *)(_COMM_PAGE_SIGNATURE + _COMM_PAGE_RW_OFFSET),
	    MIN(_COMM_PAGE_SIGNATURELEN, strlen(_COMM_PAGE64_SIGNATURE_STRING)));
#endif

	*((uint16_t*)(_COMM_PAGE_VERSION + _COMM_PAGE_RW_OFFSET)) = (uint16_t) _COMM_PAGE_THIS_VERSION;

	commpage_init_cpu_capabilities();
	commpage_set_timestamp(0, 0, 0, 0, 0);

	if (_cpu_capabilities & kCache32) {
		c2 = 32;
	} else if (_cpu_capabilities & kCache64) {
		c2 = 64;
	} else if (_cpu_capabilities & kCache128) {
		c2 = 128;
	} else {
		c2 = 0;
	}

	*((uint16_t*)(_COMM_PAGE_CACHE_LINESIZE + _COMM_PAGE_RW_OFFSET)) = c2;

	commpage_update_active_cpus();
	cpufamily = cpuid_get_cpufamily();
	*((uint8_t*)(_COMM_PAGE_CPU_CLUSTERS + _COMM_PAGE_RW_OFFSET)) = (uint8_t) ml_get_cluster_count();
	*((uint8_t*)(_COMM_PAGE_PHYSICAL_CPUS + _COMM_PAGE_RW_OFFSET)) = (uint8_t) machine_info.physical_cpu_max;
	*((uint8_t*)(_COMM_PAGE_LOGICAL_CPUS + _COMM_PAGE_RW_OFFSET)) = (uint8_t) machine_info.logical_cpu_max;
	*((uint64_t*)(_COMM_PAGE_MEMORY_SIZE + _COMM_PAGE_RW_OFFSET)) = machine_info.max_mem;
	*((uint32_t*)(_COMM_PAGE_CPUFAMILY + _COMM_PAGE_RW_OFFSET)) = (uint32_t)cpufamily;
	*((uint32_t*)(_COMM_PAGE_DEV_FIRM_LEGACY + _COMM_PAGE_RW_OFFSET)) = (uint32_t)PE_i_can_has_debugger(NULL);
	*((uint32_t*)(_COMM_PAGE_DEV_FIRM + _COMM_PAGE_RO_OFFSET)) = (uint32_t)PE_i_can_has_debugger(NULL);
	*((uint8_t*)(_COMM_PAGE_USER_TIMEBASE + _COMM_PAGE_RW_OFFSET)) = user_timebase_type();

	// Populate logical CPU -> logical cluster table
	ml_map_cpus_to_clusters((uint8_t*)(_COMM_PAGE_CPU_TO_CLUSTER + _COMM_PAGE_RW_OFFSET));

	*((uint8_t*)(_COMM_PAGE_CONT_HWCLOCK + _COMM_PAGE_RW_OFFSET)) = (uint8_t)user_cont_hwclock_allowed();
	*((uint8_t*)(_COMM_PAGE_KERNEL_PAGE_SHIFT_LEGACY + _COMM_PAGE_RW_OFFSET)) = (uint8_t) page_shift;
	*((uint8_t*)(_COMM_PAGE_KERNEL_PAGE_SHIFT + _COMM_PAGE_RO_OFFSET)) = (uint8_t) page_shift;

#if __arm64__
	*((uint8_t*)(_COMM_PAGE_USER_PAGE_SHIFT_32_LEGACY + _COMM_PAGE_RW_OFFSET)) = (uint8_t) page_shift_user32;
	*((uint8_t*)(_COMM_PAGE_USER_PAGE_SHIFT_32 + _COMM_PAGE_RO_OFFSET)) = (uint8_t) page_shift_user32;
	*((uint8_t*)(_COMM_PAGE_USER_PAGE_SHIFT_64_LEGACY + _COMM_PAGE_RW_OFFSET)) = (uint8_t) SIXTEENK_PAGE_SHIFT;
	*((uint8_t*)(_COMM_PAGE_USER_PAGE_SHIFT_64 + _COMM_PAGE_RO_OFFSET)) = (uint8_t) SIXTEENK_PAGE_SHIFT;
#endif /* __arm64__ */

	commpage_update_timebase();
	commpage_update_mach_continuous_time(0);

	clock_sec_t secs;
	clock_usec_t microsecs;
	clock_get_boottime_microtime(&secs, &microsecs);
	commpage_update_boottime(secs * USEC_PER_SEC + microsecs);

	/*
	 * set commpage approximate time to zero for initialization.
	 * scheduler shall populate correct value before running user thread
	 */
	*((uint64_t *)(_COMM_PAGE_APPROX_TIME + _COMM_PAGE_RW_OFFSET)) = 0;
#ifdef CONFIG_MACH_APPROXIMATE_TIME
	*((uint8_t *)(_COMM_PAGE_APPROX_TIME_SUPPORTED + _COMM_PAGE_RW_OFFSET)) = 1;
#else
	*((uint8_t *)(_COMM_PAGE_APPROX_TIME_SUPPORTED + _COMM_PAGE_RW_OFFSET)) = 0;
#endif

	commpage_update_kdebug_state();

#if CONFIG_ATM
	commpage_update_atm_diagnostic_config(atm_get_diagnostic_config());
#endif


	*((uint64_t*)(_COMM_PAGE_REMOTETIME_PARAMS + _COMM_PAGE_RW_OFFSET)) = BT_RESET_SENTINEL_TS;

#if CONFIG_QUIESCE_COUNTER
	cpu_quiescent_set_storage((_Atomic uint64_t *)(_COMM_PAGE_CPU_QUIESCENT_COUNTER +
	    _COMM_PAGE_RW_OFFSET));
#endif /* CONFIG_QUIESCE_COUNTER */

	/*
	 * Set random values for targets in Apple Security Bounty
	 * addr should be unmapped for userland processes
	 * kaddr should be unmapped for kernel
	 */
	uint64_t asb_value, asb_addr, asb_kvalue, asb_kaddr;
	uint64_t asb_rand_vals[] = {
		0x93e78adcded4d3d5, 0xd16c5b76ad99bccf, 0x67dfbbd12c4a594e, 0x7365636e6f6f544f,
		0x239a974c9811e04b, 0xbf60e7fa45741446, 0x8acf5210b466b05, 0x67dfbbd12c4a594e
	};
	const int nrandval = sizeof(asb_rand_vals) / sizeof(asb_rand_vals[0]);
	uint8_t randidx;

	read_random(&randidx, sizeof(uint8_t));
	asb_value = asb_rand_vals[randidx++ % nrandval];
	*((uint64_t*)(_COMM_PAGE_ASB_TARGET_VALUE + _COMM_PAGE_RW_OFFSET)) = asb_value;

	// userspace faulting address should be > MACH_VM_MAX_ADDRESS
	asb_addr = asb_rand_vals[randidx++ % nrandval];
	uint64_t user_min = MACH_VM_MAX_ADDRESS;
	uint64_t user_max = UINT64_MAX;
	asb_addr %= (user_max - user_min);
	asb_addr += user_min;
	*((uint64_t*)(_COMM_PAGE_ASB_TARGET_ADDRESS + _COMM_PAGE_RW_OFFSET)) = asb_addr;

	asb_kvalue = asb_rand_vals[randidx++ % nrandval];
	*((uint64_t*)(_COMM_PAGE_ASB_TARGET_KERN_VALUE + _COMM_PAGE_RW_OFFSET)) = asb_kvalue;

	// kernel faulting address should be < VM_MIN_KERNEL_ADDRESS
	asb_kaddr = asb_rand_vals[randidx++ % nrandval];
	uint64_t kernel_min = 0x0LL;
	uint64_t kernel_max = VM_MIN_KERNEL_ADDRESS;
	asb_kaddr %= (kernel_max - kernel_min);
	asb_kaddr += kernel_min;
	*((uint64_t*)(_COMM_PAGE_ASB_TARGET_KERN_ADDRESS + _COMM_PAGE_RW_OFFSET)) = asb_kaddr;
}

#define COMMPAGE_TEXT_SEGMENT "__TEXT_EXEC"
#define COMMPAGE_TEXT_SECTION "__commpage_text"

/* Get a pointer to the start of the ARM PFZ code section. This macro tell the
 * linker that the storage for the variable here is at the start of the section */
extern char commpage_text_start[]
__SECTION_START_SYM(COMMPAGE_TEXT_SEGMENT, COMMPAGE_TEXT_SECTION);

/* Get a pointer to the end of the ARM PFZ code section. This macro tell the
 * linker that the storage for the variable here is at the end of the section */
extern char commpage_text_end[]
__SECTION_END_SYM(COMMPAGE_TEXT_SEGMENT, COMMPAGE_TEXT_SECTION);

/* This is defined in the commpage text section as a symbol at the start of the preemptible
 * functions */
extern char commpage_text_preemptible_functions;

#if CONFIG_ARM_PFZ
static size_t size_of_pfz = 0;
#endif

/* This is the opcode for brk #666 */
#define BRK_666_OPCODE 0xD4205340

void
commpage_text_populate(void)
{
#if CONFIG_ARM_PFZ
	size_t size_of_commpage_text = commpage_text_end - commpage_text_start;
	if (size_of_commpage_text == 0) {
		panic("ARM comm page text section %s,%s missing", COMMPAGE_TEXT_SEGMENT, COMMPAGE_TEXT_SECTION);
	}
	assert(size_of_commpage_text <= PAGE_SIZE);
	assert(size_of_commpage_text > 0);

	/* Get the size of the PFZ half of the comm page text section. */
	size_of_pfz = &commpage_text_preemptible_functions - commpage_text_start;

	// Copy the code segment of comm page text section into the PFZ
	memcpy((void *) _COMM_PAGE64_TEXT_START_ADDRESS, (void *) commpage_text_start, size_of_commpage_text);

	// Make sure to populate the rest of it with brk 666 so that undefined code
	// doesn't get  run
	memset((char *) _COMM_PAGE64_TEXT_START_ADDRESS + size_of_commpage_text, BRK_666_OPCODE,
	    PAGE_SIZE - size_of_commpage_text);
#endif
}

uint32_t
commpage_is_in_pfz64(addr64_t addr64)
{
#if CONFIG_ARM_PFZ
	if ((addr64 >= commpage_text64_location) &&
	    (addr64 < (commpage_text64_location + size_of_pfz))) {
		return 1;
	} else {
		return 0;
	}
#else
#pragma unused (addr64)
	return 0;
#endif
}


void
commpage_set_timestamp(
	uint64_t        tbr,
	uint64_t        secs,
	uint64_t        frac,
	uint64_t        scale,
	uint64_t        tick_per_sec)
{
	new_commpage_timeofday_data_t *commpage_timeofday_datap;

	if (commPagePtr == 0) {
		return;
	}

	commpage_timeofday_datap =  (new_commpage_timeofday_data_t *)(_COMM_PAGE_NEWTIMEOFDAY_DATA + _COMM_PAGE_RW_OFFSET);

	commpage_timeofday_datap->TimeStamp_tick = 0x0ULL;

	__builtin_arm_dmb(DMB_ISH);

	commpage_timeofday_datap->TimeStamp_sec = secs;
	commpage_timeofday_datap->TimeStamp_frac = frac;
	commpage_timeofday_datap->Ticks_scale = scale;
	commpage_timeofday_datap->Ticks_per_sec = tick_per_sec;

	__builtin_arm_dmb(DMB_ISH);

	commpage_timeofday_datap->TimeStamp_tick = tbr;

}

/*
 * Update _COMM_PAGE_MEMORY_PRESSURE.  Called periodically from vm's compute_memory_pressure()
 */

void
commpage_set_memory_pressure(
	unsigned int    pressure )
{
	if (commPagePtr == 0) {
		return;
	}
	*((uint32_t *)(_COMM_PAGE_MEMORY_PRESSURE + _COMM_PAGE_RW_OFFSET)) = pressure;
}

/*
 * Determine number of CPUs on this system.
 */
static int
commpage_cpus( void )
{
	int cpus;

	cpus = machine_info.max_cpus;

	if (cpus == 0) {
		panic("commpage cpus==0");
	}
	if (cpus > 0xFF) {
		cpus = 0xFF;
	}

	return cpus;
}

uint64_t
_get_cpu_capabilities(void)
{
	return _cpu_capabilities;
}

vm_address_t
_get_commpage_priv_address(void)
{
	return commpage_rw_addr;
}

vm_address_t
_get_commpage_ro_address(void)
{
	return commpage_kernel_ro_addr;
}

vm_address_t
_get_commpage_text_priv_address(void)
{
	return commpage_rw_text_addr;
}

#if defined(__arm64__)
/**
 * Initializes all commpage entries and sysctls for EL0 visible features in ID_AA64ISAR0_EL1
 */
static void
commpage_init_arm_optional_features_isar0(uint64_t *commpage_bits)
{
	uint64_t bits = 0;
	uint64_t isar0 = __builtin_arm_rsr64("ID_AA64ISAR0_EL1");

	if ((isar0 & ID_AA64ISAR0_EL1_TS_MASK) >= ID_AA64ISAR0_EL1_TS_FLAGM_EN) {
		gARM_FEAT_FlagM = 1;
		bits |= kHasFEATFlagM;
	}
	if ((isar0 & ID_AA64ISAR0_EL1_TS_MASK) >= ID_AA64ISAR0_EL1_TS_FLAGM2_EN) {
		gARM_FEAT_FlagM2 = 1;
		bits |= kHasFEATFlagM2;
	}
	if ((isar0 & ID_AA64ISAR0_EL1_FHM_MASK) >= ID_AA64ISAR0_EL1_FHM_8_2) {
		gARM_FEAT_FHM = 1;
		bits |= kHasFeatFHM;
	}
	if ((isar0 & ID_AA64ISAR0_EL1_DP_MASK) >= ID_AA64ISAR0_EL1_DP_EN) {
		gARM_FEAT_DotProd = 1;
		bits |= kHasFeatDotProd;
	}
	if ((isar0 & ID_AA64ISAR0_EL1_SHA3_MASK) >= ID_AA64ISAR0_EL1_SHA3_EN) {
		gARM_FEAT_SHA3 = 1;
		bits |= kHasFeatSHA3;
	}
	if ((isar0 & ID_AA64ISAR0_EL1_RDM_MASK) >= ID_AA64ISAR0_EL1_RDM_EN) {
		gARM_FEAT_RDM = 1;
		bits |= kHasFeatRDM;
	}
	if ((isar0 & ID_AA64ISAR0_EL1_ATOMIC_MASK) >= ID_AA64ISAR0_EL1_ATOMIC_8_1) {
		gARM_FEAT_LSE = 1;
		bits |= kHasFeatLSE;
	}
	if ((isar0 & ID_AA64ISAR0_EL1_SHA2_MASK) >= ID_AA64ISAR0_EL1_SHA2_512_EN) {
		gARM_FEAT_SHA512 = 1;
		bits |= kHasFeatSHA512;
	}
	if ((isar0 & ID_AA64ISAR0_EL1_CRC32_MASK) == ID_AA64ISAR0_EL1_CRC32_EN) {
		gARMv8Crc32 = 1;
		bits |= kHasARMv8Crc32;
	}

#if __ARM_V8_CRYPTO_EXTENSIONS__
	/**
	 * T7000 has a bug in the ISAR0 register that reports that PMULL is not
	 * supported when it actually is. To work around this, for all of the crypto
	 * extensions, just check if they're supported using the board_config.h
	 * values.
	 */
	gARM_FEAT_PMULL = 1;
	gARM_FEAT_SHA1 = 1;
	gARM_FEAT_AES = 1;
	gARM_FEAT_SHA256 = 1;
	bits |= kHasARMv8Crypto;
#endif /* __ARM_V8_CRYPTO_EXTENSIONS__ */

	*commpage_bits |= bits;
}

/**
 * Initializes all commpage entries and sysctls for EL0 visible features in ID_AA64ISAR1_EL1
 */
static void
commpage_init_arm_optional_features_isar1(uint64_t *commpage_bits)
{
	uint64_t bits = 0;
	uint64_t isar1 = __builtin_arm_rsr64("ID_AA64ISAR1_EL1");
	uint64_t sctlr = __builtin_arm_rsr64("SCTLR_EL1");

	if ((isar1 & ID_AA64ISAR1_EL1_SPECRES_MASK) >= ID_AA64ISAR1_EL1_SPECRES_EN &&
	    sctlr & SCTLR_EnRCTX) {
		gARM_FEAT_SPECRES = 1;
		bits |= kHasFeatSPECRES;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_SB_MASK) >= ID_AA64ISAR1_EL1_SB_EN) {
		gARM_FEAT_SB = 1;
		bits |= kHasFeatSB;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_FRINTTS_MASK) >= ID_AA64ISAR1_EL1_FRINTTS_EN) {
		gARM_FEAT_FRINTTS = 1;
		bits |= kHasFeatFRINTTS;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_GPI_MASK) >= ID_AA64ISAR1_EL1_GPI_EN) {
		gARMv8Gpi = 1;
		bits |= kHasArmv8GPI;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_LRCPC_MASK) >= ID_AA64ISAR1_EL1_LRCPC_EN) {
		gARM_FEAT_LRCPC = 1;
		bits |= kHasFeatLRCPC;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_LRCPC_MASK) >= ID_AA64ISAR1_EL1_LRCP2C_EN) {
		gARM_FEAT_LRCPC2 = 1;
		bits |= kHasFeatLRCPC2;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_FCMA_MASK) >= ID_AA64ISAR1_EL1_FCMA_EN) {
		gARM_FEAT_FCMA = 1;
		bits |= kHasFeatFCMA;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_JSCVT_MASK) >= ID_AA64ISAR1_EL1_JSCVT_EN) {
		gARM_FEAT_JSCVT = 1;
		bits |= kHasFeatJSCVT;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_API_MASK) >= ID_AA64ISAR1_EL1_API_PAuth_EN) {
		gARM_FEAT_PAuth = 1;
		bits |= kHasFeatPAuth;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_API_MASK) >= ID_AA64ISAR1_EL1_API_PAuth2_EN) {
		gARM_FEAT_PAuth2 = 1;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_API_MASK) >= ID_AA64ISAR1_EL1_API_FPAC_EN) {
		gARM_FEAT_FPAC = 1;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_API_MASK) >= ID_AA64ISAR1_EL1_API_FPACCOMBINE) {
		gARM_FEAT_FPACCOMBINE = 1;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_DPB_MASK) >= ID_AA64ISAR1_EL1_DPB_EN) {
		gARM_FEAT_DPB = 1;
		bits |= kHasFeatDPB;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_DPB_MASK) >= ID_AA64ISAR1_EL1_DPB2_EN) {
		gARM_FEAT_DPB2 = 1;
		bits |= kHasFeatDPB2;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_BF16_MASK) >= ID_AA64ISAR1_EL1_BF16_EN) {
		gARM_FEAT_BF16 = 1;
	}
	if ((isar1 & ID_AA64ISAR1_EL1_I8MM_MASK) >= ID_AA64ISAR1_EL1_I8MM_EN) {
		gARM_FEAT_I8MM = 1;
	}

	*commpage_bits |= bits;
}

/**
 * Initializes all commpage entries and sysctls for EL0 visible features in ID_AA64ISAR2_EL1
 */
static void
commpage_init_arm_optional_features_isar2(void)
{
	uint64_t isar2 = __builtin_arm_rsr64("ID_AA64ISAR2_EL1");

	if ((isar2 & ID_AA64ISAR2_EL1_WFxT_MASK) >= ID_AA64ISAR2_EL1_WFxT_EN) {
		gARM_FEAT_WFxT = 1;
	}
	if ((isar2 & ID_AA64ISAR2_EL1_RPRES_MASK) >= ID_AA64ISAR2_EL1_RPRES_EN) {
		gARM_FEAT_RPRES = 1;
	}
}

/**
 * Initializes all commpage entries and sysctls for EL0 visible features in ID_AA64MMFR0_EL1
 */
static void
commpage_init_arm_optional_features_mmfr0(uint64_t *commpage_bits)
{
	uint64_t bits = 0;
	uint64_t mmfr0 = __builtin_arm_rsr64("ID_AA64MMFR0_EL1");

	if ((mmfr0 & ID_AA64MMFR0_EL1_ECV_MASK) >= ID_AA64MMFR0_EL1_ECV_EN) {
		gARM_FEAT_ECV = 1;
	}

	*commpage_bits |= bits;
}

/**
 * Initializes all commpage entries and sysctls for EL0 visible features in ID_AA64MMFR2_EL1
 */
static void
commpage_init_arm_optional_features_mmfr2(uint64_t *commpage_bits)
{
	uint64_t bits = 0;
	uint64_t mmfr2 = __builtin_arm_rsr64("ID_AA64MMFR2_EL1");

	if ((mmfr2 & ID_AA64MMFR2_EL1_AT_MASK) >= ID_AA64MMFR2_EL1_AT_LSE2_EN) {
		gARM_FEAT_LSE2 = 1;
		bits |= kHasFeatLSE2;
	}

	*commpage_bits |= bits;
}

/**
 * Initializes all commpage entries and sysctls for EL0 visible features in ID_AA64PFR0_EL1
 */
static void
commpage_init_arm_optional_features_pfr0(uint64_t *commpage_bits)
{
	uint64_t bits = 0;
	uint64_t pfr0 = __builtin_arm_rsr64("ID_AA64PFR0_EL1");

	if ((pfr0 & ID_AA64PFR0_EL1_CSV3_MASK) >= ID_AA64PFR0_EL1_CSV3_EN) {
		gARM_FEAT_CSV3 = 1;
		bits |= kHasFeatCSV3;
	}
	if ((pfr0 & ID_AA64PFR0_EL1_CSV2_MASK) >= ID_AA64PFR0_EL1_CSV2_EN) {
		gARM_FEAT_CSV2 = 1;
		bits |= kHasFeatCSV2;
	}
	if ((pfr0 & ID_AA64PFR0_EL1_DIT_MASK) >= ID_AA64PFR0_EL1_DIT_EN) {
		gARM_FEAT_DIT = 1;
		bits |= kHasFeatDIT;
	}
	if ((pfr0 & ID_AA64PFR0_EL1_AdvSIMD_MASK) != ID_AA64PFR0_EL1_AdvSIMD_DIS) {
		gARM_AdvSIMD = 1;
		bits |= kHasAdvSIMD;
		if ((pfr0 & ID_AA64PFR0_EL1_AdvSIMD_MASK) >= ID_AA64PFR0_EL1_AdvSIMD_HPFPCVT) {
			gARM_AdvSIMD_HPFPCvt = 1;
			bits |= kHasAdvSIMD_HPFPCvt;
		}
		if ((pfr0 & ID_AA64PFR0_EL1_AdvSIMD_MASK) >= ID_AA64PFR0_EL1_AdvSIMD_FP16) {
			gARM_FEAT_FP16 = 1;
			bits |= kHasFeatFP16;
		}
	}

	*commpage_bits |= bits;
}

/**
 * Initializes all commpage entries and sysctls for EL0 visible features in ID_AA64PFR1_EL1
 */
static void
commpage_init_arm_optional_features_pfr1(uint64_t *commpage_bits)
{
	uint64_t pfr1 = __builtin_arm_rsr64("ID_AA64PFR1_EL1");

	if ((pfr1 & ID_AA64PFR1_EL1_SSBS_MASK) >= ID_AA64PFR1_EL1_SSBS_EN) {
		gARM_FEAT_SSBS = 1;
	}

	if ((pfr1 & ID_AA64PFR1_EL1_BT_MASK) >= ID_AA64PFR1_EL1_BT_EN) {
		gARM_FEAT_BTI = 1;
	}

	unsigned int sme_version = arm_sme_version();
	if (sme_version >= 1) {
		gARM_FEAT_SME = 1;
		*commpage_bits |= kHasFeatSME;
	}
	if (sme_version >= 2) {
		gARM_FEAT_SME2 = 1;
		*commpage_bits |= kHasFeatSME2;
	}

}

/**
 * Initializes all commpage entries and sysctls for EL0 visible features in ID_AA64SMFR0_EL1
 */
__attribute__((target("sme")))
static void
commpage_init_arm_optional_features_smfr0(void)
{
	if (arm_sme_version() == 0) {
		/*
		 * We can safely read ID_AA64SMFR0_EL1 on SME-less devices.  But
		 * arm_sme_version() == 0 could also mean that the user
		 * defeatured SME with a boot-arg.
		 */
		return;
	}

	uint64_t smfr0 = __builtin_arm_rsr64("ID_AA64SMFR0_EL1");

	/*
	 * ID_AA64SMFR0_EL1 has to be parsed differently from other feature ID
	 * registers.  See "Alternative ID scheme used for ID_AA64SMFR0_EL1" in
	 * the ARM ARM.
	 */

	/* 1-bit fields */
	if (smfr0 & ID_AA64SMFR0_EL1_F32F32_EN) {
		gARM_SME_F32F32 = 1;
	}
	if (smfr0 & ID_AA64SMFR0_EL1_BI32I32_EN) {
		gARM_SME_BI32I32 = 1;
	}
	if (smfr0 & ID_AA64SMFR0_EL1_B16F32_EN) {
		gARM_SME_B16F32 = 1;
	}
	if (smfr0 & ID_AA64SMFR0_EL1_F16F32_EN) {
		gARM_SME_F16F32 = 1;
	}
	if (smfr0 & ID_AA64SMFR0_EL1_F64F64_EN) {
		gARM_FEAT_SME_F64F64 = 1;
	}

	/* 4-bit fields (0 bits are ignored) */
	if ((smfr0 & ID_AA64SMFR0_EL1_I8I32_EN) == ID_AA64SMFR0_EL1_I8I32_EN) {
		gARM_SME_I8I32 = 1;
	}
	if ((smfr0 & ID_AA64SMFR0_EL1_I16I32_EN) == ID_AA64SMFR0_EL1_I16I32_EN) {
		gARM_SME_I16I32 = 1;
	}
	if ((smfr0 & ID_AA64SMFR0_EL1_I16I64_EN) == ID_AA64SMFR0_EL1_I16I64_EN) {
		gARM_FEAT_SME_I16I64 = 1;
	}
}

static void
commpage_init_arm_optional_features_mmfr1(uint64_t *commpage_bits)
{
	uint64_t bits = 0;
	const uint64_t mmfr1 = __builtin_arm_rsr64("ID_AA64MMFR1_EL1");

	if ((mmfr1 & ID_AA64MMFR1_EL1_AFP_MASK) == ID_AA64MMFR1_EL1_AFP_EN) {
		gARM_FEAT_AFP = 1;
		bits |= kHasFeatAFP;
	}

	*commpage_bits |= bits;
}

/**
 * Read the system register @name, attempt to set set bits of @mask if not
 * already, test if bits were actually set, reset the register to its
 * previous value if required, and 'return' @mask with only bits that
 * were successfully set (or already set) in the system register. */
#define _test_sys_bits(name, mask) ({ \
	const uint64_t src = __builtin_arm_rsr64(#name); \
    uint64_t test = src | mask; \
    if (test != src) { \
	__builtin_arm_wsr64(#name, test); \
	test = __builtin_arm_rsr64(#name); \
	if (test != src) { \
	    __builtin_arm_wsr64(#name, src); \
	}\
    } \
    mask & test; \
})

/**
 * Reports whether FPU exceptions are supported.
 * Possible FPU exceptions are :
 * - input denormal;
 * - inexact;
 * - underflow;
 * - overflow;
 * - divide by 0;
 * - invalid operation.
 *
 * Any of those can be supported or not but for now, we consider that
 * it all or nothing : FPU exceptions support flag set <=> all 6 exceptions
 * a supported.
 */
static void
commpage_init_arm_optional_features_fpcr(uint64_t *commpage_bits)
{
	uint64_t support_mask = FPCR_IDE | FPCR_IXE | FPCR_UFE | FPCR_OFE |
	    FPCR_DZE | FPCR_IOE;
	uint64_t FPCR_bits = _test_sys_bits(FPCR, support_mask);
	if (FPCR_bits == support_mask) {
		gARM_FP_SyncExceptions = 1;
		*commpage_bits |= kHasFP_SyncExceptions;
	}
}

/**
 * Initializes all commpage entries and sysctls for ARM64 optional features accessible from EL0.
 */
static void
commpage_init_arm_optional_features(uint64_t *commpage_bits)
{
	commpage_init_arm_optional_features_isar0(commpage_bits);
	commpage_init_arm_optional_features_isar1(commpage_bits);
	commpage_init_arm_optional_features_isar2();
	commpage_init_arm_optional_features_mmfr0(commpage_bits);
	commpage_init_arm_optional_features_mmfr1(commpage_bits);
	commpage_init_arm_optional_features_mmfr2(commpage_bits);
	commpage_init_arm_optional_features_pfr0(commpage_bits);
	commpage_init_arm_optional_features_pfr1(commpage_bits);
	commpage_init_arm_optional_features_smfr0();
	commpage_init_arm_optional_features_fpcr(commpage_bits);
}
#endif /* __arm64__ */

/*
 * Initialize _cpu_capabilities vector
 */
static void
commpage_init_cpu_capabilities( void )
{
	uint64_t bits;
	int cpus;
	ml_cpu_info_t cpu_info;

	bits = 0;
	ml_cpu_get_info(&cpu_info);

	switch (cpu_info.cache_line_size) {
	case 128:
		bits |= kCache128;
		break;
	case 64:
		bits |= kCache64;
		break;
	case 32:
		bits |= kCache32;
		break;
	default:
		break;
	}
	cpus = commpage_cpus();

	if (cpus == 1) {
		bits |= kUP;
	}

	bits |= (cpus << kNumCPUsShift);

	bits |= kFastThreadLocalStorage;        // TPIDRURO for TLS

	bits |= kHasVfp;

#if defined(__arm64__)
	bits |= kHasFMA;
#endif
	bits |= kHasEvent;
#ifdef __arm64__
	commpage_init_arm_optional_features(&bits);
#endif



#if HAS_UCNORMAL_MEM
	gUCNormalMem = 1;
	bits |= kHasUCNormalMemory;
#endif

	_cpu_capabilities = bits;

	*((uint32_t *)(_COMM_PAGE_CPU_CAPABILITIES + _COMM_PAGE_RW_OFFSET)) = (uint32_t)_cpu_capabilities;
	*((uint64_t *)(_COMM_PAGE_CPU_CAPABILITIES64 + _COMM_PAGE_RW_OFFSET)) = _cpu_capabilities;

}

/*
 * Updated every time a logical CPU goes offline/online
 */
void
commpage_update_active_cpus(void)
{
	if (!commPagePtr) {
		return;
	}
	*((uint8_t *)(_COMM_PAGE_ACTIVE_CPUS + _COMM_PAGE_RW_OFFSET)) = (uint8_t)processor_avail_count;

}

/*
 * Update the commpage bits for mach_absolute_time and mach_continuous_time (for userspace)
 */
void
commpage_update_timebase(void)
{
	if (commPagePtr) {
		*((uint64_t*)(_COMM_PAGE_TIMEBASE_OFFSET + _COMM_PAGE_RW_OFFSET)) = rtclock_base_abstime;
	}
}

/*
 * Update the commpage with current kdebug state: whether tracing is enabled, a
 * typefilter is present, and continuous time should be used for timestamps.
 *
 * Disregards configuration and set to 0 if tracing is disabled.
 */
void
commpage_update_kdebug_state(void)
{
	if (commPagePtr) {
		uint32_t state = kdebug_commpage_state();
		*((volatile uint32_t *)(_COMM_PAGE_KDEBUG_ENABLE + _COMM_PAGE_RW_OFFSET)) = state;
	}
}

/* Ditto for atm_diagnostic_config */
void
commpage_update_atm_diagnostic_config(uint32_t diagnostic_config)
{
	if (commPagePtr) {
		*((volatile uint32_t*)(_COMM_PAGE_ATM_DIAGNOSTIC_CONFIG + _COMM_PAGE_RW_OFFSET)) = diagnostic_config;
	}
}

/*
 * Update the commpage data with the state of multiuser mode for
 * this device. Allowing various services in userspace to avoid
 * IPC in the (more common) non-multiuser environment.
 */
void
commpage_update_multiuser_config(uint32_t multiuser_config)
{
	if (commPagePtr) {
		*((volatile uint32_t *)(_COMM_PAGE_MULTIUSER_CONFIG + _COMM_PAGE_RW_OFFSET)) = multiuser_config;
	}
}

/*
 * update the commpage data for
 * last known value of mach_absolute_time()
 */

void
commpage_update_mach_approximate_time(uint64_t abstime)
{
#ifdef CONFIG_MACH_APPROXIMATE_TIME
	if (!commPagePtr) {
		return;
	}

	uint64_t *approx_time_base = (uint64_t *)(uintptr_t)(_COMM_PAGE_APPROX_TIME + _COMM_PAGE_RW_OFFSET);

	uint64_t saved_data = os_atomic_load_wide(approx_time_base, relaxed);
	if (saved_data < abstime) {
		/*
		 * ignore the success/fail return value assuming that
		 * if the value has been updated since we last read it,
		 * someone else has written a timestamp that is new enough.
		 */
		__unused bool ret = os_atomic_cmpxchg(approx_time_base,
		    saved_data, abstime, relaxed);
	}


#else /* CONFIG_MACH_APPROXIMATE_TIME */
#pragma unused (abstime)
#endif
}

/*
 * update the commpage data's total system sleep time for
 * userspace call to mach_continuous_time()
 */
void
commpage_update_mach_continuous_time(uint64_t sleeptime)
{
	if (!commPagePtr) {
		return;
	}

	uint64_t *cont_time_base = (uint64_t *)(uintptr_t)(_COMM_PAGE_CONT_TIMEBASE + _COMM_PAGE_RW_OFFSET);

	os_atomic_store_wide(cont_time_base, sleeptime, relaxed);

}

void
commpage_update_mach_continuous_time_hw_offset(uint64_t offset)
{
	*((uint64_t *)(_COMM_PAGE_CONT_HW_TIMEBASE + _COMM_PAGE_RW_OFFSET)) = offset;
}

/*
 * update the commpage's value for the boot time
 */
void
commpage_update_boottime(uint64_t value)
{
	if (!commPagePtr) {
		return;
	}

	uint64_t *boottime_usec = (uint64_t *)(uintptr_t)(_COMM_PAGE_BOOTTIME_USEC + _COMM_PAGE_RW_OFFSET);

	os_atomic_store_wide(boottime_usec, value, relaxed);

}

/*
 * set the commpage's remote time params for
 * userspace call to mach_bridge_remote_time()
 */
void
commpage_set_remotetime_params(double rate, uint64_t base_local_ts, uint64_t base_remote_ts)
{
	if (commPagePtr) {
#ifdef __arm64__
		struct bt_params *paramsp = (struct bt_params *)(_COMM_PAGE_REMOTETIME_PARAMS + _COMM_PAGE_RW_OFFSET);
		paramsp->base_local_ts = 0;
		__builtin_arm_dmb(DMB_ISH);
		paramsp->rate = rate;
		paramsp->base_remote_ts = base_remote_ts;
		__builtin_arm_dmb(DMB_ISH);
		paramsp->base_local_ts = base_local_ts;  //This will act as a generation count
#endif /* __arm64__ */
	}
}


/*
 * update the commpage with if dtrace user land probes are enabled
 */
void
commpage_update_dof(boolean_t enabled)
{
#if CONFIG_DTRACE
	*((uint8_t*)(_COMM_PAGE_DTRACE_DOF_ENABLED + _COMM_PAGE_RW_OFFSET)) = (enabled ? 1 : 0);
#else
	(void)enabled;
#endif
}

/*
 * update the dyld global config flags
 */
void
commpage_update_dyld_flags(uint64_t value)
{
	*((uint64_t*)(_COMM_PAGE_DYLD_FLAGS + _COMM_PAGE_RW_OFFSET)) = value;

}