summaryrefslogtreecommitdiffstats
path: root/src/vppinfra/linux/mem.c
blob: c20de9c21031944a070cf53aeab9ccb68d150a88 (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
/*
 * Copyright (c) 2017 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define _GNU_SOURCE
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/mount.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <linux/mempolicy.h>
#include <linux/memfd.h>

#include <vppinfra/clib.h>
#include <vppinfra/mem.h>
#include <vppinfra/time.h>
#include <vppinfra/format.h>
#include <vppinfra/clib_error.h>
#include <vppinfra/linux/syscall.h>
#include <vppinfra/linux/sysfs.h>

#ifndef F_LINUX_SPECIFIC_BASE
#define F_LINUX_SPECIFIC_BASE 1024
#endif

#ifndef F_ADD_SEALS
#define F_ADD_SEALS (F_LINUX_SPECIFIC_BASE + 9)
#define F_GET_SEALS (F_LINUX_SPECIFIC_BASE + 10)

#define F_SEAL_SEAL     0x0001	/* prevent further seals from being set */
#define F_SEAL_SHRINK   0x0002	/* prevent file from shrinking */
#define F_SEAL_GROW     0x0004	/* prevent file from growing */
#define F_SEAL_WRITE    0x0008	/* prevent writes */
#endif

#ifndef MFD_HUGETLB
#define MFD_HUGETLB 0x0004U
#endif

#ifndef MAP_HUGE_SHIFT
#define MAP_HUGE_SHIFT 26
#endif

#ifndef MFD_HUGE_SHIFT
#define MFD_HUGE_SHIFT 26
#endif

#ifndef MAP_FIXED_NOREPLACE
#define MAP_FIXED_NOREPLACE 0x100000
#endif

uword
clib_mem_get_default_hugepage_size (void)
{
  unformat_input_t input;
  static u32 size = 0;
  int fd;

  if (size)
    goto done;

  /*
   * If the kernel doesn't support hugepages, /proc/meminfo won't
   * say anything about it. Use the regular page size as a default.
   */
  size = clib_mem_get_page_size () / 1024;

  if ((fd = open ("/proc/meminfo", 0)) == -1)
    return 0;

  unformat_init_clib_file (&input, fd);

  while (unformat_check_input (&input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (&input, "Hugepagesize:%_%u kB", &size))
	;
      else
	unformat_skip_line (&input);
    }
  unformat_free (&input);
  close (fd);
done:
  return 1024ULL * size;
}

static clib_mem_page_sz_t
legacy_get_log2_default_hugepage_size (void)
{
  clib_mem_page_sz_t log2_page_size = CLIB_MEM_PAGE_SZ_UNKNOWN;
  FILE *fp;
  char tmp[33] = { };

  if ((fp = fopen ("/proc/meminfo", "r")) == NULL)
    return CLIB_MEM_PAGE_SZ_UNKNOWN;

  while (fscanf (fp, "%32s", tmp) > 0)
    if (strncmp ("Hugepagesize:", tmp, 13) == 0)
      {
	u32 size;
	if (fscanf (fp, "%u", &size) > 0)
	  log2_page_size = 10 + min_log2 (size);
	break;
      }

  fclose (fp);
  return log2_page_size;
}

void
clib_mem_main_init ()
{
  clib_mem_main_t *mm = &clib_mem_main;
  uword page_size;
  void *va;
  int fd;

  if (mm->log2_page_sz != CLIB_MEM_PAGE_SZ_UNKNOWN)
    return;

  /* system page size */
  page_size = sysconf (_SC_PAGESIZE);
  mm->log2_page_sz = min_log2 (page_size);

  /* default system hugeppage size */
  if ((fd = memfd_create ("test", MFD_HUGETLB)) != -1)
    {
      mm->log2_default_hugepage_sz = clib_mem_get_fd_log2_page_size (fd);
      close (fd);
    }
  else				/* likely kernel older than 4.14 */
    mm->log2_default_hugepage_sz = legacy_get_log2_default_hugepage_size ();

  /* numa nodes */
  va = mmap (0, page_size, PROT_READ | PROT_WRITE, MAP_PRIVATE |
	     MAP_ANONYMOUS, -1, 0);
  if (va == MAP_FAILED)
    return;

  if (mlock (va, page_size))
    goto done;

  for (int i = 0; i < CLIB_MAX_NUMAS; i++)
    {
      int status;
      if (move_pages (0, 1, &va, &i, &status, 0) == 0)
	mm->numa_node_bitmap |= 1ULL << i;
    }

done:
  munmap (va, page_size);
}

u64
clib_mem_get_fd_page_size (int fd)
{
  struct stat st = { 0 };
  if (fstat (fd, &st) == -1)
    return 0;
  return st.st_blksize;
}

clib_mem_page_sz_t
clib_mem_get_fd_log2_page_size (int fd)
{
  uword page_size = clib_mem_get_fd_page_size (fd);
  return page_size ? min_log2 (page_size) : CLIB_MEM_PAGE_SZ_UNKNOWN;
}

void
clib_mem_vm_randomize_va (uword * requested_va,
			  clib_mem_page_sz_t log2_page_size)
{
  u8 bit_mask = 15;

  if (log2_page_size <= 12)
    bit_mask = 15;
  else if (log2_page_size > 12 && log2_page_size <= 16)
    bit_mask = 3;
  else
    bit_mask = 0;

  *requested_va +=
    (clib_cpu_time_now () & bit_mask) * (1ull << log2_page_size);
}

clib_error_t *
clib_mem_vm_ext_alloc (clib_mem_vm_alloc_t * a)
{
  clib_mem_main_t *mm = &clib_mem_main;
  int fd = -1;
  clib_error_t *err = 0;
  void *addr = 0;
  u8 *filename = 0;
  int mmap_flags = 0;
  int log2_page_size;
  int n_pages;
  int old_mpol = -1;
  long unsigned int old_mask[16] = { 0 };

  /* save old numa mem policy if needed */
  if (a->flags & (CLIB_MEM_VM_F_NUMA_PREFER | CLIB_MEM_VM_F_NUMA_FORCE))
    {
      int rv;
      rv = get_mempolicy (&old_mpol, old_mask, sizeof (old_mask) * 8 + 1,
			  0, 0);

      if (rv == -1)
	{
	  if (a->numa_node != 0 && (a->flags & CLIB_MEM_VM_F_NUMA_FORCE) != 0)
	    {
	      err = clib_error_return_unix (0, "get_mempolicy");
	      goto error;
	    }
	  else
	    old_mpol = -1;
	}
    }

  if (a->flags & CLIB_MEM_VM_F_LOCKED)
    mmap_flags |= MAP_LOCKED;

  /* if we are creating shared segment, we need file descriptor */
  if (a->flags & CLIB_MEM_VM_F_SHARED)
    {
      mmap_flags |= MAP_SHARED;
      /* if hugepages are needed we need to create mount point */
      if (a->flags & CLIB_MEM_VM_F_HUGETLB)
	{
	  log2_page_size = CLIB_MEM_PAGE_SZ_DEFAULT_HUGE;
	  mmap_flags |= MAP_LOCKED;
	}
      else
	log2_page_size = CLIB_MEM_PAGE_SZ_DEFAULT;

      if ((fd = clib_mem_vm_create_fd (log2_page_size, "%s", a->name)) == -1)
	{
	  err = clib_error_return (0, "%U", format_clib_error, mm->error);
	  goto error;
	}

      log2_page_size = clib_mem_get_fd_log2_page_size (fd);
      if (log2_page_size == 0)
	{
	  err = clib_error_return_unix (0, "cannot determine page size");
	  goto error;
	}

      if (a->requested_va)
	{
	  clib_mem_vm_randomize_va (&a->requested_va, log2_page_size);
	  mmap_flags |= MAP_FIXED;
	}
    }
  else				/* not CLIB_MEM_VM_F_SHARED */
    {
      mmap_flags |= MAP_PRIVATE | MAP_ANONYMOUS;
      if (a->flags & CLIB_MEM_VM_F_HUGETLB)
	{
	  mmap_flags |= MAP_HUGETLB;
	  log2_page_size = 21;
	}
      else
	{
	  log2_page_size = min_log2 (sysconf (_SC_PAGESIZE));
	}
    }

  n_pages = ((a->size - 1) >> log2_page_size) + 1;

  if (a->flags & CLIB_MEM_VM_F_HUGETLB_PREALLOC)
    {
      err = clib_sysfs_prealloc_hugepages (a->numa_node, log2_page_size,
					   n_pages);
      if (err)
	goto error;

    }

  if (fd != -1)
    if ((ftruncate (fd, (u64) n_pages * (1 << log2_page_size))) == -1)
      {
	err = clib_error_return_unix (0, "ftruncate");
	goto error;
      }

  if (old_mpol != -1)
    {
      int rv;
      long unsigned int mask[16] = { 0 };
      mask[0] = 1 << a->numa_node;
      rv = set_mempolicy (MPOL_BIND, mask, sizeof (mask) * 8 + 1);
      if (rv == -1 && a->numa_node != 0 &&
	  (a->flags & CLIB_MEM_VM_F_NUMA_FORCE) != 0)
	{
	  err = clib_error_return_unix (0, "set_mempolicy");
	  goto error;
	}
    }

  addr = mmap (uword_to_pointer (a->requested_va, void *), a->size,
	       (PROT_READ | PROT_WRITE), mmap_flags, fd, 0);
  if (addr == MAP_FAILED)
    {
      err = clib_error_return_unix (0, "mmap");
      goto error;
    }

  /* re-apply old numa memory policy */
  if (old_mpol != -1 &&
      set_mempolicy (old_mpol, old_mask, sizeof (old_mask) * 8 + 1) == -1)
    {
      err = clib_error_return_unix (0, "set_mempolicy");
      goto error;
    }

  a->log2_page_size = log2_page_size;
  a->n_pages = n_pages;
  a->addr = addr;
  a->fd = fd;
  CLIB_MEM_UNPOISON (addr, a->size);
  goto done;

error:
  if (fd != -1)
    close (fd);

done:
  vec_free (filename);
  return err;
}

void
clib_mem_vm_ext_free (clib_mem_vm_alloc_t * a)
{
  if (a != 0)
    {
      clib_mem_vm_free (a->addr, 1ull << a->log2_page_size);
      if (a->fd != -1)
	close (a->fd);
    }
}

static int
legacy_memfd_create (u8 * name)
{
  clib_mem_main_t *mm = &clib_mem_main;
  int fd = -1;
  char *mount_dir;
  u8 *filename;

  /* create mount directory */
  if ((mount_dir = mkdtemp ("/tmp/hugepage_mount.XXXXXX")) == 0)
    {
      vec_reset_length (mm->error);
      mm->error = clib_error_return_unix (mm->error, "mkdtemp");
      return CLIB_MEM_ERROR;
    }

  if (mount ("none", mount_dir, "hugetlbfs", 0, NULL))
    {
      rmdir ((char *) mount_dir);
      vec_reset_length (mm->error);
      mm->error = clib_error_return_unix (mm->error, "mount");
      return CLIB_MEM_ERROR;
    }

  filename = format (0, "%s/%s%c", mount_dir, name, 0);

  if ((fd = open ((char *) filename, O_CREAT | O_RDWR, 0755)) == -1)
    {
      vec_reset_length (mm->error);
      mm->error = clib_error_return_unix (mm->error, "mkdtemp");
    }

  umount2 ((char *) mount_dir, MNT_DETACH);
  rmdir ((char *) mount_dir);
  vec_free (filename);

  return fd;
}

int
clib_mem_vm_create_fd (clib_mem_page_sz_t log2_page_size, char *fmt, ...)
{
  clib_mem_main_t *mm = &clib_mem_main;
  int fd;
  unsigned int memfd_flags;
  va_list va;
  u8 *s = 0;

  if (log2_page_size == mm->log2_page_sz)
    log2_page_size = CLIB_MEM_PAGE_SZ_DEFAULT;

  switch (log2_page_size)
    {
    case CLIB_MEM_PAGE_SZ_UNKNOWN:
      return CLIB_MEM_ERROR;
    case CLIB_MEM_PAGE_SZ_DEFAULT:
      memfd_flags = MFD_ALLOW_SEALING;
      break;
    case CLIB_MEM_PAGE_SZ_DEFAULT_HUGE:
      memfd_flags = MFD_HUGETLB;
      break;
    default:
      memfd_flags = MFD_HUGETLB | log2_page_size << MFD_HUGE_SHIFT;
    }

  va_start (va, fmt);
  s = va_format (0, fmt, &va);
  va_end (va);

  /* memfd_create maximum string size is 249 chars without trailing zero */
  if (vec_len (s) > 249)
    _vec_len (s) = 249;
  vec_add1 (s, 0);

  /* memfd_create introduced in kernel 3.17, we don't support older kernels */
  fd = memfd_create ((char *) s, memfd_flags);

  /* kernel versions < 4.14 does not support memfd_create for huge pages */
  if (fd == -1 && errno == EINVAL &&
      log2_page_size == CLIB_MEM_PAGE_SZ_DEFAULT_HUGE)
    {
      fd = legacy_memfd_create (s);
    }
  else if (fd == -1)
    {
      vec_reset_length (mm->error);
      mm->error = clib_error_return_unix (mm->error, "memfd_create");
      vec_free (s);
      return CLIB_MEM_ERROR;
    }

  vec_free (s);

  if ((memfd_flags & MFD_ALLOW_SEALING) &&
      ((fcntl (fd, F_ADD_SEALS, F_SEAL_SHRINK)) == -1))
    {
      vec_reset_length (mm->error);
      mm->error = clib_error_return_unix (mm->error, "fcntl (F_ADD_SEALS)");
      close (fd);
      return CLIB_MEM_ERROR;
    }

  return fd;
}

uword
clib_mem_vm_reserve (uword start, uword size, clib_mem_page_sz_t log2_page_sz)
{
  clib_mem_main_t *mm = &clib_mem_main;
  uword pagesize = 1ULL << log2_page_sz;
  uword sys_page_sz = 1ULL << mm->log2_page_sz;
  uword n_bytes;
  void *base = 0, *p;

  size = round_pow2 (size, pagesize);

  /* in adition of requested reservation, we also rserve one system page
   * (typically 4K) adjacent to the start off reservation */

  if (start)
    {
      /* start address is provided, so we just need to make sure we are not
       * replacing existing map */
      if (start & pow2_mask (log2_page_sz))
	return ~0;

      base = (void *) start - sys_page_sz;
      base = mmap (base, size + sys_page_sz, PROT_NONE,
		   MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED_NOREPLACE, -1, 0);
      return (base == MAP_FAILED) ? ~0 : start;
    }

  /* to make sure that we get reservation aligned to page_size we need to
   * request one additional page as mmap will return us address which is
   * aligned only to system page size */
  base = mmap (0, size + pagesize, PROT_NONE,
	       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

  if (base == MAP_FAILED)
    return ~0;

  /* return additional space at the end of allocation */
  p = base + size + pagesize;
  n_bytes = (uword) p & pow2_mask (log2_page_sz);
  if (n_bytes)
    {
      p -= n_bytes;
      munmap (p, n_bytes);
    }

  /* return additional space at the start of allocation */
  n_bytes = pagesize - sys_page_sz - n_bytes;
  if (n_bytes)
    {
      munmap (base, n_bytes);
      base += n_bytes;
    }

  return (uword) base + sys_page_sz;
}

clib_mem_vm_map_hdr_t *
clib_mem_vm_get_next_map_hdr (clib_mem_vm_map_hdr_t * hdr)
{
  clib_mem_main_t *mm = &clib_mem_main;
  uword sys_page_sz = 1 << mm->log2_page_sz;
  clib_mem_vm_map_hdr_t *next;
  if (hdr == 0)
    {
      hdr = mm->first_map;
      if (hdr)
	mprotect (hdr, sys_page_sz, PROT_READ);
      return hdr;
    }
  next = hdr->next;
  mprotect (hdr, sys_page_sz, PROT_NONE);
  if (next)
    mprotect (next, sys_page_sz, PROT_READ);
  return next;
}

void *
clib_mem_vm_map_internal (void *base, clib_mem_page_sz_t log2_page_sz,
			  uword size, int fd, uword offset, char *name)
{
  clib_mem_main_t *mm = &clib_mem_main;
  clib_mem_vm_map_hdr_t *hdr;
  uword sys_page_sz = 1 << mm->log2_page_sz;
  int mmap_flags = MAP_FIXED, is_huge = 0;

  if (fd != -1)
    {
      mmap_flags |= MAP_SHARED;
      log2_page_sz = clib_mem_get_fd_log2_page_size (fd);
      if (log2_page_sz > mm->log2_page_sz)
	is_huge = 1;
    }
  else
    {
      mmap_flags |= MAP_PRIVATE | MAP_ANONYMOUS;

      if (log2_page_sz == mm->log2_page_sz)
	log2_page_sz = CLIB_MEM_PAGE_SZ_DEFAULT;

      switch (log2_page_sz)
	{
	case CLIB_MEM_PAGE_SZ_UNKNOWN:
	  /* will fail later */
	  break;
	case CLIB_MEM_PAGE_SZ_DEFAULT:
	  log2_page_sz = mm->log2_page_sz;
	  break;
	case CLIB_MEM_PAGE_SZ_DEFAULT_HUGE:
	  mmap_flags |= MAP_HUGETLB;
	  log2_page_sz = mm->log2_default_hugepage_sz;
	  is_huge = 1;
	  break;
	default:
	  mmap_flags |= MAP_HUGETLB;
	  mmap_flags |= log2_page_sz << MAP_HUGE_SHIFT;
	  is_huge = 1;
	}
    }

  if (log2_page_sz == CLIB_MEM_PAGE_SZ_UNKNOWN)
    return CLIB_MEM_VM_MAP_FAILED;

  size = round_pow2 (size, 1 << log2_page_sz);

  base = (void *) clib_mem_vm_reserve ((uword) base, size, log2_page_sz);

  if (base == (void *) ~0)
    return CLIB_MEM_VM_MAP_FAILED;

  base = mmap (base, size, PROT_READ | PROT_WRITE, mmap_flags, fd, offset);

  if (base == MAP_FAILED)
    return CLIB_MEM_VM_MAP_FAILED;

  if (is_huge && (mlock (base, size) != 0))
    {
      munmap (base, size);
      return CLIB_MEM_VM_MAP_FAILED;
    }

  hdr = mmap (base - sys_page_sz, sys_page_sz, PROT_READ | PROT_WRITE,
	      MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);

  if (hdr != base - sys_page_sz)
    {
      munmap (base, size);
      return CLIB_MEM_VM_MAP_FAILED;
    }

  if (mm->last_map)
    {
      mprotect (mm->last_map, sys_page_sz, PROT_READ | PROT_WRITE);
      mm->last_map->next = hdr;
      mprotect (mm->last_map, sys_page_sz, PROT_NONE);
    }
  else
    mm->first_map = hdr;

  hdr->next = 0;
  hdr->prev = mm->last_map;
  mm->last_map = hdr;

  hdr->base_addr = (uword) base;
  hdr->log2_page_sz = log2_page_sz;
  hdr->num_pages = size >> log2_page_sz;
  hdr->fd = fd;
  snprintf (hdr->name, CLIB_VM_MAP_HDR_NAME_MAX_LEN - 1, "%s", (char *) name);
  hdr->name[CLIB_VM_MAP_HDR_NAME_MAX_LEN - 1] = 0;
  mprotect (hdr, sys_page_sz, PROT_NONE);

  CLIB_MEM_UNPOISON (base, size);
  return base;
}

int
clib_mem_vm_unmap (void *base)
{
  clib_mem_main_t *mm = &clib_mem_main;
  uword size, sys_page_sz = 1 << mm->log2_page_sz;
  clib_mem_vm_map_hdr_t *hdr = base - sys_page_sz;;

  if (mprotect (hdr, sys_page_sz, PROT_READ | PROT_WRITE) != 0)
    return CLIB_MEM_ERROR;

  size = hdr->num_pages << hdr->log2_page_sz;
  if (munmap ((void *) hdr->base_addr, size) != 0)
    return CLIB_MEM_ERROR;

  if (hdr->next)
    {
      mprotect (hdr->next, sys_page_sz, PROT_READ | PROT_WRITE);
      hdr->next->prev = hdr->prev;
      mprotect (hdr->next, sys_page_sz, PROT_NONE);
    }
  else
    mm->last_map = hdr->prev;

  if (hdr->prev)
    {
      mprotect (hdr->prev, sys_page_sz, PROT_READ | PROT_WRITE);
      hdr->prev->next = hdr->next;
      mprotect (hdr->prev, sys_page_sz, PROT_NONE);
    }
  else
    mm->first_map = hdr->next;

  if (munmap (hdr, sys_page_sz) != 0)
    return CLIB_MEM_ERROR;

  return 0;
}

void
clib_mem_get_page_stats (void *start, clib_mem_page_sz_t log2_page_size,
			 uword n_pages, clib_mem_page_stats_t * stats)
{
  int i, *status = 0;
  void **ptr = 0;

  log2_page_size = clib_mem_log2_page_size_validate (log2_page_size);

  vec_validate (status, n_pages - 1);
  vec_validate (ptr, n_pages - 1);

  for (i = 0; i < n_pages; i++)
    ptr[i] = start + (i << log2_page_size);

  clib_memset (stats, 0, sizeof (clib_mem_page_stats_t));

  if (move_pages (0, n_pages, ptr, 0, status, 0) != 0)
    {
      stats->unknown = n_pages;
      return;
    }

  for (i = 0; i < n_pages; i++)
    {
      if (status[i] >= 0 && status[i] < CLIB_MAX_NUMAS)
	{
	  stats->mapped++;
	  stats->per_numa[status[i]]++;
	}
      else if (status[i] == -EFAULT)
	stats->not_mapped++;
      else
	stats->unknown++;
    }
}


u64 *
clib_mem_vm_get_paddr (void *mem, clib_mem_page_sz_t log2_page_size,
		       int n_pages)
{
  int pagesize = sysconf (_SC_PAGESIZE);
  int fd;
  int i;
  u64 *r = 0;

  log2_page_size = clib_mem_log2_page_size_validate (log2_page_size);

  if ((fd = open ((char *) "/proc/self/pagemap", O_RDONLY)) == -1)
    return 0;

  for (i = 0; i < n_pages; i++)
    {
      u64 seek, pagemap = 0;
      uword vaddr = pointer_to_uword (mem) + (((u64) i) << log2_page_size);
      seek = ((u64) vaddr / pagesize) * sizeof (u64);
      if (lseek (fd, seek, SEEK_SET) != seek)
	goto done;

      if (read (fd, &pagemap, sizeof (pagemap)) != (sizeof (pagemap)))
	goto done;

      if ((pagemap & (1ULL << 63)) == 0)
	goto done;

      pagemap &= pow2_mask (55);
      vec_add1 (r, pagemap * pagesize);
    }

done:
  close (fd);
  if (vec_len (r) != n_pages)
    {
      vec_free (r);
      return 0;
    }
  return r;
}

clib_error_t *
clib_mem_vm_ext_map (clib_mem_vm_map_t * a)
{
  long unsigned int old_mask[16] = { 0 };
  int mmap_flags = MAP_SHARED;
  clib_error_t *err = 0;
  int old_mpol = -1;
  void *addr;
  int rv;

  if (a->numa_node)
    {
      rv = get_mempolicy (&old_mpol, old_mask, sizeof (old_mask) * 8 + 1, 0,
			  0);

      if (rv == -1)
	{
	  err = clib_error_return_unix (0, "get_mempolicy");
	  goto done;
	}
    }

  if (a->requested_va)
    mmap_flags |= MAP_FIXED;

  if (old_mpol != -1)
    {
      long unsigned int mask[16] = { 0 };
      mask[0] = 1 << a->numa_node;
      rv = set_mempolicy (MPOL_BIND, mask, sizeof (mask) * 8 + 1);
      if (rv == -1)
	{
	  err = clib_error_return_unix (0, "set_mempolicy");
	  goto done;
	}
    }

  addr = (void *) mmap (uword_to_pointer (a->requested_va, void *), a->size,
			PROT_READ | PROT_WRITE, mmap_flags, a->fd, 0);

  if (addr == MAP_FAILED)
    return clib_error_return_unix (0, "mmap");

  /* re-apply old numa memory policy */
  if (old_mpol != -1 &&
      set_mempolicy (old_mpol, old_mask, sizeof (old_mask) * 8 + 1) == -1)
    {
      err = clib_error_return_unix (0, "set_mempolicy");
      goto done;
    }

  a->addr = addr;
  CLIB_MEM_UNPOISON (addr, a->size);

done:
  return err;
}

int
clib_mem_set_numa_affinity (u8 numa_node, int force)
{
  clib_mem_main_t *mm = &clib_mem_main;
  long unsigned int mask[16] = { 0 };
  int mask_len = sizeof (mask) * 8 + 1;

  /* no numa support */
  if (mm->numa_node_bitmap == 0)
    {
      if (numa_node)
	{
	  vec_reset_length (mm->error);
	  mm->error = clib_error_return (mm->error, "%s: numa not supported",
					 (char *) __func__);
	  return CLIB_MEM_ERROR;
	}
      else
	return 0;
    }

  mask[0] = 1 << numa_node;

  if (set_mempolicy (force ? MPOL_BIND : MPOL_PREFERRED, mask, mask_len))
    goto error;

  vec_reset_length (mm->error);
  return 0;

error:
  vec_reset_length (mm->error);
  mm->error = clib_error_return_unix (mm->error, (char *) __func__);
  return CLIB_MEM_ERROR;
}

int
clib_mem_set_default_numa_affinity ()
{
  clib_mem_main_t *mm = &clib_mem_main;

  if (set_mempolicy (MPOL_DEFAULT, 0, 0))
    {
      vec_reset_length (mm->error);
      mm->error = clib_error_return_unix (mm->error, (char *) __func__);
      return CLIB_MEM_ERROR;
    }
  return 0;
}

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */