/
pmap.c
6312 lines (5491 loc) · 154 KB
/
pmap.c
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
/* $NetBSD: pmap.c,v 1.380 2020/03/22 00:16:16 ad Exp $ */
/*
* Copyright (c) 2008, 2010, 2016, 2017, 2019, 2020 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Doran, and by Maxime Villard.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 2007 Manuel Bouyer.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 2006 Mathieu Ropert <mro@adviseo.fr>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* Copyright 2001 (c) Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Frank van der Linden for Wasabi Systems, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.380 2020/03/22 00:16:16 ad Exp $");
#include "opt_user_ldt.h"
#include "opt_lockdebug.h"
#include "opt_multiprocessor.h"
#include "opt_xen.h"
#include "opt_svs.h"
#include "opt_kaslr.h"
#define __MUTEX_PRIVATE /* for assertions */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/pool.h>
#include <sys/kernel.h>
#include <sys/atomic.h>
#include <sys/cpu.h>
#include <sys/intr.h>
#include <sys/xcall.h>
#include <sys/kcore.h>
#include <sys/asan.h>
#include <sys/msan.h>
#include <uvm/uvm.h>
#include <uvm/pmap/pmap_pvt.h>
#include <dev/isa/isareg.h>
#include <machine/specialreg.h>
#include <machine/gdt.h>
#include <machine/isa_machdep.h>
#include <machine/cpuvar.h>
#include <machine/cputypes.h>
#include <machine/cpu_rng.h>
#include <x86/pmap.h>
#include <x86/pmap_pv.h>
#include <x86/i82489reg.h>
#include <x86/i82489var.h>
#ifdef XEN
#include <xen/include/public/xen.h>
#include <xen/hypervisor.h>
#endif
/*
* general info:
*
* - for an explanation of how the x86 MMU hardware works see
* the comments in <machine/pte.h>.
*
* - for an explanation of the general memory structure used by
* this pmap (including the recursive mapping), see the comments
* in <machine/pmap.h>.
*
* this file contains the code for the "pmap module." the module's
* job is to manage the hardware's virtual to physical address mappings.
* note that there are two levels of mapping in the VM system:
*
* [1] the upper layer of the VM system uses vm_map's and vm_map_entry's
* to map ranges of virtual address space to objects/files. for
* example, the vm_map may say: "map VA 0x1000 to 0x22000 read-only
* to the file /bin/ls starting at offset zero." note that
* the upper layer mapping is not concerned with how individual
* vm_pages are mapped.
*
* [2] the lower layer of the VM system (the pmap) maintains the mappings
* from virtual addresses. it is concerned with which vm_page is
* mapped where. for example, when you run /bin/ls and start
* at page 0x1000 the fault routine may lookup the correct page
* of the /bin/ls file and then ask the pmap layer to establish
* a mapping for it.
*
* note that information in the lower layer of the VM system can be
* thrown away since it can easily be reconstructed from the info
* in the upper layer.
*
* data structures we use include:
*
* - struct pmap: describes the address space of one thread
* - struct pmap_page: describes one pv-tracked page, without
* necessarily a corresponding vm_page
* - struct pv_entry: describes one <PMAP,VA> mapping of a PA
* - pmap_page::pp_pvlist: there is one list per pv-tracked page of
* physical memory. the pp_pvlist points to a list of pv_entry
* structures which describe all the <PMAP,VA> pairs that this
* page is mapped in. this is critical for page based operations
* such as pmap_page_protect() [change protection on _all_ mappings
* of a page]
*/
/*
* Locking
*
* We have the following locks that we must deal with, listed in the order
* that they are acquired:
*
* pg->uobject->vmobjlock, pg->uanon->an_lock
*
* For managed pages, these per-object locks are taken by the VM system
* before calling into the pmap module - either a read or write hold.
* The lock hold prevent pages from changing identity while the pmap is
* operating on them. For example, the same lock is held across a call
* to pmap_remove() and the following call to pmap_update(), so that a
* page does not gain a new identity while its TLB visibility is stale.
*
* pmap->pm_lock
*
* This lock protects the fields in the pmap structure including the
* non-kernel PDEs in the PDP, the PTEs, and PTPs and connected data
* structures. For modifying unmanaged kernel PTEs it is not needed as
* kernel PDEs are never freed, and the kernel is expected to be self
* consistent (and the lock can't be taken for unmanaged kernel PTEs,
* because they can be modified from interrupt context).
*
* pmaps_lock
*
* This lock protects the list of active pmaps (headed by "pmaps").
* It's acqired when adding or removing pmaps or adjusting kernel PDEs.
*
* pp_lock
*
* This per-page lock protects PV entry lists and the embedded PV entry
* in each vm_page, allowing for concurrent operation on pages by
* different pmaps. This is a spin mutex at IPL_VM, because at the
* points it is taken context switching is usually not tolerable, and
* spin mutexes must block out interrupts that could take kernel_lock.
*/
/* uvm_object is abused here to index pmap_pages; make assertions happy. */
#ifdef DIAGNOSTIC
#define PMAP_DUMMY_LOCK(pm) rw_enter(&(pm)->pm_dummy_lock, RW_WRITER)
#define PMAP_DUMMY_UNLOCK(pm) rw_exit(&(pm)->pm_dummy_lock)
#else
#define PMAP_DUMMY_LOCK(pm)
#define PMAP_DUMMY_UNLOCK(pm)
#endif
static const struct uvm_pagerops pmap_pager = {
/* nothing */
};
const vaddr_t ptp_masks[] = PTP_MASK_INITIALIZER;
const vaddr_t ptp_frames[] = PTP_FRAME_INITIALIZER;
const int ptp_shifts[] = PTP_SHIFT_INITIALIZER;
const long nkptpmax[] = NKPTPMAX_INITIALIZER;
const long nbpd[] = NBPD_INITIALIZER;
#ifdef i386
pd_entry_t * const normal_pdes[] = PDES_INITIALIZER;
#else
pd_entry_t *normal_pdes[3];
#endif
long nkptp[] = NKPTP_INITIALIZER;
struct pmap_head pmaps;
kmutex_t pmaps_lock __cacheline_aligned;
struct pcpu_area *pcpuarea __read_mostly;
static vaddr_t pmap_maxkvaddr;
/*
* Misc. event counters.
*/
struct evcnt pmap_iobmp_evcnt;
struct evcnt pmap_ldt_evcnt;
/*
* PAT
*/
static bool cpu_pat_enabled __read_mostly = false;
/*
* Global data structures
*/
static struct pmap kernel_pmap_store __cacheline_aligned; /* kernel's pmap */
struct pmap *const kernel_pmap_ptr = &kernel_pmap_store;
static rb_tree_t pmap_kernel_rb __cacheline_aligned;
struct bootspace bootspace __read_mostly;
struct slotspace slotspace __read_mostly;
/* Set to PTE_NX if supported. */
pd_entry_t pmap_pg_nx __read_mostly = 0;
/* Set to PTE_G if supported. */
pd_entry_t pmap_pg_g __read_mostly = 0;
/* Set to true if large pages are supported. */
int pmap_largepages __read_mostly = 0;
paddr_t lowmem_rsvd __read_mostly;
paddr_t avail_start __read_mostly; /* PA of first available physical page */
paddr_t avail_end __read_mostly; /* PA of last available physical page */
#ifdef XENPV
paddr_t pmap_pa_start; /* PA of first physical page for this domain */
paddr_t pmap_pa_end; /* PA of last physical page for this domain */
#endif
#define VM_PAGE_TO_PP(pg) (&(pg)->mdpage.mp_pp)
#define PMAP_CHECK_PP(pp) \
KASSERTMSG((pp)->pp_lock.mtx_ipl._ipl == IPL_VM, "bad pmap_page %p", pp)
/*
* Other data structures
*/
static pt_entry_t protection_codes[8] __read_mostly;
static bool pmap_initialized __read_mostly = false; /* pmap_init done yet? */
/*
* The following two vaddr_t's are used during system startup to keep track of
* how much of the kernel's VM space we have used. Once the system is started,
* the management of the remaining kernel VM space is turned over to the
* kernel_map vm_map.
*/
static vaddr_t virtual_avail __read_mostly; /* VA of first free KVA */
static vaddr_t virtual_end __read_mostly; /* VA of last free KVA */
#ifndef XENPV
/*
* LAPIC virtual address, and fake physical address.
*/
volatile vaddr_t local_apic_va __read_mostly;
paddr_t local_apic_pa __read_mostly;
#endif
/*
* pool that pmap structures are allocated from
*/
struct pool_cache pmap_cache;
static int pmap_ctor(void *, void *, int);
static void pmap_dtor(void *, void *);
/*
* pv_entry cache
*/
static struct pool_cache pmap_pv_cache;
#ifdef __HAVE_DIRECT_MAP
vaddr_t pmap_direct_base __read_mostly;
vaddr_t pmap_direct_end __read_mostly;
#endif
#ifndef __HAVE_DIRECT_MAP
/*
* Special VAs and the PTEs that map them
*/
static pt_entry_t *early_zero_pte;
static void pmap_vpage_cpualloc(struct cpu_info *);
#ifdef XENPV
char *early_zerop; /* also referenced from xen_locore() */
#else
static char *early_zerop;
#endif
#endif
int pmap_enter_default(pmap_t, vaddr_t, paddr_t, vm_prot_t, u_int);
/* PDP pool and its callbacks */
static struct pool pmap_pdp_pool;
static void pmap_pdp_init(pd_entry_t *);
static void pmap_pdp_fini(pd_entry_t *);
#ifdef PAE
/* need to allocate items of 4 pages */
static void *pmap_pdp_alloc(struct pool *, int);
static void pmap_pdp_free(struct pool *, void *);
static struct pool_allocator pmap_pdp_allocator = {
.pa_alloc = pmap_pdp_alloc,
.pa_free = pmap_pdp_free,
.pa_pagesz = PAGE_SIZE * PDP_SIZE,
};
#endif
extern vaddr_t idt_vaddr;
extern paddr_t idt_paddr;
extern vaddr_t gdt_vaddr;
extern paddr_t gdt_paddr;
extern vaddr_t ldt_vaddr;
extern paddr_t ldt_paddr;
#ifdef i386
/* stuff to fix the pentium f00f bug */
extern vaddr_t pentium_idt_vaddr;
#endif
/* Array of freshly allocated PTPs, for pmap_get_ptp(). */
struct pmap_ptparray {
struct vm_page *pg[PTP_LEVELS + 1];
bool alloced[PTP_LEVELS + 1];
};
/*
* PV tree prototypes
*/
static int pmap_compare_key(void *, const void *, const void *);
static int pmap_compare_nodes(void *, const void *, const void *);
/* Read-black tree */
static const rb_tree_ops_t pmap_rbtree_ops = {
.rbto_compare_nodes = pmap_compare_nodes,
.rbto_compare_key = pmap_compare_key,
.rbto_node_offset = offsetof(struct pv_entry, pve_rb),
.rbto_context = NULL
};
/*
* Local prototypes
*/
#ifdef __HAVE_PCPU_AREA
static void pmap_init_pcpu(void);
#endif
#ifdef __HAVE_DIRECT_MAP
static void pmap_init_directmap(struct pmap *);
#endif
#if !defined(XENPV)
static void pmap_remap_global(void);
#endif
#ifndef XENPV
static void pmap_init_lapic(void);
static void pmap_remap_largepages(void);
#endif
static int pmap_get_ptp(struct pmap *, struct pmap_ptparray *, vaddr_t, int,
struct vm_page **);
static void pmap_unget_ptp(struct pmap *, struct pmap_ptparray *);
static void pmap_install_ptp(struct pmap *, struct pmap_ptparray *, vaddr_t,
pd_entry_t * const *);
static struct vm_page *pmap_find_ptp(struct pmap *, vaddr_t, int);
static void pmap_freepage(struct pmap *, struct vm_page *, int);
static void pmap_free_ptp(struct pmap *, struct vm_page *, vaddr_t,
pt_entry_t *, pd_entry_t * const *);
static bool pmap_remove_pte(struct pmap *, struct vm_page *, pt_entry_t *,
vaddr_t, struct pv_entry **);
static void pmap_remove_ptes(struct pmap *, struct vm_page *, vaddr_t, vaddr_t,
vaddr_t, struct pv_entry **);
static void pmap_alloc_level(struct pmap *, vaddr_t, long *);
static void pmap_load1(struct lwp *, struct pmap *, struct pmap *);
static void pmap_reactivate(struct pmap *);
/*
* p m a p h e l p e r f u n c t i o n s
*/
static inline void
pmap_stats_update(struct pmap *pmap, int resid_diff, int wired_diff)
{
KASSERT(cold || mutex_owned(&pmap->pm_lock));
pmap->pm_stats.resident_count += resid_diff;
pmap->pm_stats.wired_count += wired_diff;
}
static inline void
pmap_stats_update_bypte(struct pmap *pmap, pt_entry_t npte, pt_entry_t opte)
{
int resid_diff = ((npte & PTE_P) ? 1 : 0) - ((opte & PTE_P) ? 1 : 0);
int wired_diff = ((npte & PTE_WIRED) ? 1 : 0) - ((opte & PTE_WIRED) ? 1 : 0);
KASSERT((npte & (PTE_P | PTE_WIRED)) != PTE_WIRED);
KASSERT((opte & (PTE_P | PTE_WIRED)) != PTE_WIRED);
pmap_stats_update(pmap, resid_diff, wired_diff);
}
/*
* ptp_to_pmap: lookup pmap by ptp
*/
static inline struct pmap *
ptp_to_pmap(struct vm_page *ptp)
{
struct pmap *pmap;
if (ptp == NULL) {
return pmap_kernel();
}
pmap = (struct pmap *)ptp->uobject;
KASSERT(pmap != NULL);
KASSERT(&pmap->pm_obj[0] == ptp->uobject);
return pmap;
}
static inline struct pv_pte *
pve_to_pvpte(struct pv_entry *pve)
{
if (pve == NULL)
return NULL;
KASSERT((void *)&pve->pve_pte == (void *)pve);
return &pve->pve_pte;
}
static inline struct pv_entry *
pvpte_to_pve(struct pv_pte *pvpte)
{
struct pv_entry *pve = (void *)pvpte;
KASSERT(pve_to_pvpte(pve) == pvpte);
return pve;
}
/*
* Return true if the pmap page has an embedded PV entry.
*/
static inline bool
pv_pte_embedded(struct pmap_page *pp)
{
KASSERT(mutex_owned(&pp->pp_lock));
return (bool)((vaddr_t)pp->pp_pte.pte_ptp | pp->pp_pte.pte_va);
}
/*
* pv_pte_first, pv_pte_next: PV list iterator.
*/
static inline struct pv_pte *
pv_pte_first(struct pmap_page *pp)
{
KASSERT(mutex_owned(&pp->pp_lock));
if (pv_pte_embedded(pp)) {
return &pp->pp_pte;
}
return pve_to_pvpte(LIST_FIRST(&pp->pp_pvlist));
}
static inline struct pv_pte *
pv_pte_next(struct pmap_page *pp, struct pv_pte *pvpte)
{
KASSERT(mutex_owned(&pp->pp_lock));
KASSERT(pvpte != NULL);
if (pvpte == &pp->pp_pte) {
return pve_to_pvpte(LIST_FIRST(&pp->pp_pvlist));
}
return pve_to_pvpte(LIST_NEXT(pvpte_to_pve(pvpte), pve_list));
}
static inline uint8_t
pmap_pte_to_pp_attrs(pt_entry_t pte)
{
uint8_t ret = 0;
if (pte & PTE_D)
ret |= PP_ATTRS_D;
if (pte & PTE_A)
ret |= PP_ATTRS_A;
if (pte & PTE_W)
ret |= PP_ATTRS_W;
return ret;
}
static inline pt_entry_t
pmap_pp_attrs_to_pte(uint8_t attrs)
{
pt_entry_t pte = 0;
if (attrs & PP_ATTRS_D)
pte |= PTE_D;
if (attrs & PP_ATTRS_A)
pte |= PTE_A;
if (attrs & PP_ATTRS_W)
pte |= PTE_W;
return pte;
}
/*
* pmap_is_curpmap: is this pmap the one currently loaded [in %cr3]?
* of course the kernel is always loaded
*/
bool
pmap_is_curpmap(struct pmap *pmap)
{
return ((pmap == pmap_kernel()) || (pmap == curcpu()->ci_pmap));
}
inline void
pmap_reference(struct pmap *pmap)
{
atomic_inc_uint(&pmap->pm_obj[0].uo_refs);
}
/*
* rbtree: compare two nodes.
*/
static int
pmap_compare_nodes(void *context, const void *n1, const void *n2)
{
const struct pv_entry *pve1 = n1;
const struct pv_entry *pve2 = n2;
KASSERT(pve1->pve_pte.pte_ptp == pve2->pve_pte.pte_ptp);
if (pve1->pve_pte.pte_va < pve2->pve_pte.pte_va) {
return -1;
}
if (pve1->pve_pte.pte_va > pve2->pve_pte.pte_va) {
return 1;
}
return 0;
}
/*
* rbtree: compare a node and a key.
*/
static int
pmap_compare_key(void *context, const void *n, const void *k)
{
const struct pv_entry *pve = n;
const vaddr_t key = (vaddr_t)k;
if (pve->pve_pte.pte_va < key) {
return -1;
}
if (pve->pve_pte.pte_va > key) {
return 1;
}
return 0;
}
/*
* pmap_ptp_range_set: abuse ptp->uanon to record minimum VA of PTE
*/
static inline void
pmap_ptp_range_set(struct vm_page *ptp, vaddr_t va)
{
vaddr_t *min = (vaddr_t *)&ptp->uanon;
if (va < *min) {
*min = va;
}
}
/*
* pmap_ptp_range_clip: abuse ptp->uanon to clip range of PTEs to remove
*/
static inline void
pmap_ptp_range_clip(struct vm_page *ptp, vaddr_t *startva, pt_entry_t **pte)
{
vaddr_t sclip;
if (ptp == NULL) {
return;
}
sclip = (vaddr_t)ptp->uanon;
sclip = (*startva < sclip ? sclip : *startva);
*pte += (sclip - *startva) / PAGE_SIZE;
*startva = sclip;
}
/*
* pmap_map_ptes: map a pmap's PTEs into KVM and lock them in
*
* there are several pmaps involved. some or all of them might be same.
*
* - the pmap given by the first argument
* our caller wants to access this pmap's PTEs.
*
* - pmap_kernel()
* the kernel pmap. note that it only contains the kernel part
* of the address space which is shared by any pmap. ie. any
* pmap can be used instead of pmap_kernel() for our purpose.
*
* - ci->ci_pmap
* pmap currently loaded on the cpu.
*
* - vm_map_pmap(&curproc->p_vmspace->vm_map)
* current process' pmap.
*
* => caller must lock pmap first (if not the kernel pmap)
* => must be undone with pmap_unmap_ptes before returning
* => disables kernel preemption
*/
void
pmap_map_ptes(struct pmap *pmap, struct pmap **pmap2, pd_entry_t **ptepp,
pd_entry_t * const **pdeppp)
{
struct pmap *curpmap;
struct cpu_info *ci;
lwp_t *l;
kpreempt_disable();
/* The kernel's pmap is always accessible. */
if (pmap == pmap_kernel()) {
*pmap2 = NULL;
*ptepp = PTE_BASE;
*pdeppp = normal_pdes;
return;
}
KASSERT(mutex_owned(&pmap->pm_lock));
l = curlwp;
ci = l->l_cpu;
curpmap = ci->ci_pmap;
if (pmap == curpmap) {
/*
* Already on the CPU: make it valid. This is very
* often the case during exit(), when we have switched
* to the kernel pmap in order to destroy a user pmap.
*/
if (__predict_false(ci->ci_tlbstate != TLBSTATE_VALID)) {
pmap_reactivate(pmap);
}
*pmap2 = NULL;
} else {
/*
* Toss current pmap from CPU and install new pmap, but keep
* a reference to the old one. Dropping the reference can
* can block as it needs to take locks, so defer that to
* pmap_unmap_ptes().
*/
pmap_reference(pmap);
pmap_load1(l, pmap, curpmap);
*pmap2 = curpmap;
}
KASSERT(ci->ci_tlbstate == TLBSTATE_VALID);
#ifdef DIAGNOSTIC
pmap->pm_ncsw = lwp_pctr();
#endif
*ptepp = PTE_BASE;
#if defined(XENPV) && defined(__x86_64__)
KASSERT(ci->ci_normal_pdes[PTP_LEVELS - 2] == L4_BASE);
ci->ci_normal_pdes[PTP_LEVELS - 2] = pmap->pm_pdir;
*pdeppp = ci->ci_normal_pdes;
#else
*pdeppp = normal_pdes;
#endif
}
/*
* pmap_unmap_ptes: unlock the PTE mapping of "pmap"
*
* => we cannot tolerate context switches while mapped in: assert this.
* => reenables kernel preemption.
* => does not unlock pmap.
*/
void
pmap_unmap_ptes(struct pmap *pmap, struct pmap * pmap2)
{
struct cpu_info *ci;
struct pmap *mypmap;
struct lwp *l;
KASSERT(kpreempt_disabled());
/* The kernel's pmap is always accessible. */
if (pmap == pmap_kernel()) {
kpreempt_enable();
return;
}
l = curlwp;
ci = l->l_cpu;
KASSERT(mutex_owned(&pmap->pm_lock));
KASSERT(pmap->pm_ncsw == lwp_pctr());
#if defined(XENPV) && defined(__x86_64__)
KASSERT(ci->ci_normal_pdes[PTP_LEVELS - 2] != L4_BASE);
ci->ci_normal_pdes[PTP_LEVELS - 2] = L4_BASE;
#endif
/* If not our own pmap, mark whatever's on the CPU now as lazy. */
KASSERT(ci->ci_tlbstate == TLBSTATE_VALID);
mypmap = vm_map_pmap(&l->l_proc->p_vmspace->vm_map);
if (ci->ci_pmap == vm_map_pmap(&l->l_proc->p_vmspace->vm_map)) {
ci->ci_want_pmapload = 0;
} else {
ci->ci_want_pmapload = (mypmap != pmap_kernel());
ci->ci_tlbstate = TLBSTATE_LAZY;
}
/* Now safe to re-enable preemption. */
kpreempt_enable();
/* Toss reference to other pmap taken earlier. */
if (pmap2 != NULL) {
pmap_destroy(pmap2);
}
}
inline static void
pmap_exec_account(struct pmap *pm, vaddr_t va, pt_entry_t opte, pt_entry_t npte)
{
#if !defined(__x86_64__)
if (curproc == NULL || curproc->p_vmspace == NULL ||
pm != vm_map_pmap(&curproc->p_vmspace->vm_map))
return;
if ((opte ^ npte) & PTE_X)
pmap_update_pg(va);
/*
* Executability was removed on the last executable change.
* Reset the code segment to something conservative and
* let the trap handler deal with setting the right limit.
* We can't do that because of locking constraints on the vm map.
*/
if ((opte & PTE_X) && (npte & PTE_X) == 0 && va == pm->pm_hiexec) {
struct trapframe *tf = curlwp->l_md.md_regs;
tf->tf_cs = GSEL(GUCODE_SEL, SEL_UPL);
pm->pm_hiexec = I386_MAX_EXE_ADDR;
}
#endif /* !defined(__x86_64__) */
}
#if !defined(__x86_64__)
/*
* Fixup the code segment to cover all potential executable mappings.
* returns 0 if no changes to the code segment were made.
*/
int
pmap_exec_fixup(struct vm_map *map, struct trapframe *tf, struct pcb *pcb)
{
struct vm_map_entry *ent;
struct pmap *pm = vm_map_pmap(map);
vaddr_t va = 0;
vm_map_lock_read(map);
for (ent = (&map->header)->next; ent != &map->header; ent = ent->next) {
/*
* This entry has greater va than the entries before.
* We need to make it point to the last page, not past it.
*/
if (ent->protection & VM_PROT_EXECUTE)
va = trunc_page(ent->end) - PAGE_SIZE;
}
vm_map_unlock_read(map);
if (va == pm->pm_hiexec && tf->tf_cs == GSEL(GUCODEBIG_SEL, SEL_UPL))
return 0;
pm->pm_hiexec = va;
if (pm->pm_hiexec > I386_MAX_EXE_ADDR) {
tf->tf_cs = GSEL(GUCODEBIG_SEL, SEL_UPL);
} else {
tf->tf_cs = GSEL(GUCODE_SEL, SEL_UPL);
return 0;
}
return 1;
}
#endif /* !defined(__x86_64__) */
void
pat_init(struct cpu_info *ci)
{
uint64_t pat;
if (!(ci->ci_feat_val[0] & CPUID_PAT))
return;
/* We change WT to WC. Leave all other entries the default values. */
pat = PATENTRY(0, PAT_WB) | PATENTRY(1, PAT_WC) |
PATENTRY(2, PAT_UCMINUS) | PATENTRY(3, PAT_UC) |
PATENTRY(4, PAT_WB) | PATENTRY(5, PAT_WC) |
PATENTRY(6, PAT_UCMINUS) | PATENTRY(7, PAT_UC);
wrmsr(MSR_CR_PAT, pat);
cpu_pat_enabled = true;
aprint_debug_dev(ci->ci_dev, "PAT enabled\n");
}
static pt_entry_t
pmap_pat_flags(u_int flags)
{
u_int cacheflags = (flags & PMAP_CACHE_MASK);
if (!cpu_pat_enabled) {
switch (cacheflags) {
case PMAP_NOCACHE:
case PMAP_NOCACHE_OVR:
/* results in PGC_UCMINUS on cpus which have
* the cpuid PAT but PAT "disabled"
*/
return PTE_PCD;
default:
return 0;
}
}
switch (cacheflags) {
case PMAP_NOCACHE:
return PGC_UC;
case PMAP_WRITE_COMBINE:
return PGC_WC;
case PMAP_WRITE_BACK:
return PGC_WB;
case PMAP_NOCACHE_OVR:
return PGC_UCMINUS;
}
return 0;
}
/*
* p m a p k e n t e r f u n c t i o n s
*
* functions to quickly enter/remove pages from the kernel address
* space. pmap_kremove is exported to MI kernel. we make use of
* the recursive PTE mappings.
*/
/*
* pmap_kenter_pa: enter a kernel mapping without R/M (pv_entry) tracking
*
* => no need to lock anything, assume va is already allocated
* => should be faster than normal pmap enter function
*/
void
pmap_kenter_pa(vaddr_t va, paddr_t pa, vm_prot_t prot, u_int flags)
{
pt_entry_t *pte, opte, npte;
KASSERT(!(prot & ~VM_PROT_ALL));
if (va < VM_MIN_KERNEL_ADDRESS)
pte = vtopte(va);
else
pte = kvtopte(va);
#ifdef DOM0OPS
if (pa < pmap_pa_start || pa >= pmap_pa_end) {
#ifdef DEBUG
printf_nolog("%s: pa %#" PRIxPADDR " for va %#" PRIxVADDR
" outside range\n", __func__, pa, va);
#endif /* DEBUG */
npte = pa;
} else
#endif /* DOM0OPS */
npte = pmap_pa2pte(pa);
npte |= protection_codes[prot] | PTE_P | pmap_pg_g;
npte |= pmap_pat_flags(flags);
opte = pmap_pte_testset(pte, npte); /* zap! */
/*
* XXX: make sure we are not dealing with a large page, since the only
* large pages created are for the kernel image, and they should never
* be kentered.
*/
KASSERTMSG(!(opte & PTE_PS), "PTE_PS va=%#"PRIxVADDR, va);
if ((opte & (PTE_P | PTE_A)) == (PTE_P | PTE_A)) {
/* This should not happen. */
printf_nolog("%s: mapping already present\n", __func__);
kpreempt_disable();
pmap_tlb_shootdown(pmap_kernel(), va, opte, TLBSHOOT_KENTER);
kpreempt_enable();
}
}
__strict_weak_alias(pmap_kenter_ma, pmap_kenter_pa);
#if defined(__x86_64__)