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9#include <linux/cache.h>
10#include <linux/export.h>
11#include <linux/kernel.h>
12#include <linux/errno.h>
13#include <linux/init.h>
14#include <linux/ioport.h>
15#include <linux/kexec.h>
16#include <linux/libfdt.h>
17#include <linux/mman.h>
18#include <linux/nodemask.h>
19#include <linux/memblock.h>
20#include <linux/memory.h>
21#include <linux/fs.h>
22#include <linux/io.h>
23#include <linux/mm.h>
24#include <linux/vmalloc.h>
25#include <linux/set_memory.h>
26
27#include <asm/barrier.h>
28#include <asm/cputype.h>
29#include <asm/fixmap.h>
30#include <asm/kasan.h>
31#include <asm/kernel-pgtable.h>
32#include <asm/sections.h>
33#include <asm/setup.h>
34#include <linux/sizes.h>
35#include <asm/tlb.h>
36#include <asm/mmu_context.h>
37#include <asm/ptdump.h>
38#include <asm/tlbflush.h>
39#include <asm/pgalloc.h>
40
41#define NO_BLOCK_MAPPINGS BIT(0)
42#define NO_CONT_MAPPINGS BIT(1)
43#define NO_EXEC_MAPPINGS BIT(2)
44
45u64 idmap_t0sz = TCR_T0SZ(VA_BITS_MIN);
46u64 idmap_ptrs_per_pgd = PTRS_PER_PGD;
47
48u64 __section(".mmuoff.data.write") vabits_actual;
49EXPORT_SYMBOL(vabits_actual);
50
51u64 kimage_voffset __ro_after_init;
52EXPORT_SYMBOL(kimage_voffset);
53
54
55
56
57
58unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
59EXPORT_SYMBOL(empty_zero_page);
60
61static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss;
62static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss __maybe_unused;
63static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss __maybe_unused;
64
65static DEFINE_SPINLOCK(swapper_pgdir_lock);
66
67void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd)
68{
69 pgd_t *fixmap_pgdp;
70
71 spin_lock(&swapper_pgdir_lock);
72 fixmap_pgdp = pgd_set_fixmap(__pa_symbol(pgdp));
73 WRITE_ONCE(*fixmap_pgdp, pgd);
74
75
76
77
78
79 pgd_clear_fixmap();
80 spin_unlock(&swapper_pgdir_lock);
81}
82
83pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
84 unsigned long size, pgprot_t vma_prot)
85{
86 if (!pfn_is_map_memory(pfn))
87 return pgprot_noncached(vma_prot);
88 else if (file->f_flags & O_SYNC)
89 return pgprot_writecombine(vma_prot);
90 return vma_prot;
91}
92EXPORT_SYMBOL(phys_mem_access_prot);
93
94static phys_addr_t __init early_pgtable_alloc(int shift)
95{
96 phys_addr_t phys;
97 void *ptr;
98
99 phys = memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
100 if (!phys)
101 panic("Failed to allocate page table page\n");
102
103
104
105
106
107
108 ptr = pte_set_fixmap(phys);
109
110 memset(ptr, 0, PAGE_SIZE);
111
112
113
114
115
116 pte_clear_fixmap();
117
118 return phys;
119}
120
121static bool pgattr_change_is_safe(u64 old, u64 new)
122{
123
124
125
126
127 pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE | PTE_NG;
128
129
130 if (old == 0 || new == 0)
131 return true;
132
133
134 if ((old | new) & PTE_CONT)
135 return false;
136
137
138 if (old & ~new & PTE_NG)
139 return false;
140
141
142
143
144
145
146 if (((old & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL) ||
147 (old & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL_TAGGED)) &&
148 ((new & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL) ||
149 (new & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL_TAGGED)))
150 mask |= PTE_ATTRINDX_MASK;
151
152 return ((old ^ new) & ~mask) == 0;
153}
154
155static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end,
156 phys_addr_t phys, pgprot_t prot)
157{
158 pte_t *ptep;
159
160 ptep = pte_set_fixmap_offset(pmdp, addr);
161 do {
162 pte_t old_pte = READ_ONCE(*ptep);
163
164 set_pte(ptep, pfn_pte(__phys_to_pfn(phys), prot));
165
166
167
168
169
170 BUG_ON(!pgattr_change_is_safe(pte_val(old_pte),
171 READ_ONCE(pte_val(*ptep))));
172
173 phys += PAGE_SIZE;
174 } while (ptep++, addr += PAGE_SIZE, addr != end);
175
176 pte_clear_fixmap();
177}
178
179static void alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr,
180 unsigned long end, phys_addr_t phys,
181 pgprot_t prot,
182 phys_addr_t (*pgtable_alloc)(int),
183 int flags)
184{
185 unsigned long next;
186 pmd_t pmd = READ_ONCE(*pmdp);
187
188 BUG_ON(pmd_sect(pmd));
189 if (pmd_none(pmd)) {
190 pmdval_t pmdval = PMD_TYPE_TABLE | PMD_TABLE_UXN;
191 phys_addr_t pte_phys;
192
193 if (flags & NO_EXEC_MAPPINGS)
194 pmdval |= PMD_TABLE_PXN;
195 BUG_ON(!pgtable_alloc);
196 pte_phys = pgtable_alloc(PAGE_SHIFT);
197 __pmd_populate(pmdp, pte_phys, pmdval);
198 pmd = READ_ONCE(*pmdp);
199 }
200 BUG_ON(pmd_bad(pmd));
201
202 do {
203 pgprot_t __prot = prot;
204
205 next = pte_cont_addr_end(addr, end);
206
207
208 if ((((addr | next | phys) & ~CONT_PTE_MASK) == 0) &&
209 (flags & NO_CONT_MAPPINGS) == 0)
210 __prot = __pgprot(pgprot_val(prot) | PTE_CONT);
211
212 init_pte(pmdp, addr, next, phys, __prot);
213
214 phys += next - addr;
215 } while (addr = next, addr != end);
216}
217
218static void init_pmd(pud_t *pudp, unsigned long addr, unsigned long end,
219 phys_addr_t phys, pgprot_t prot,
220 phys_addr_t (*pgtable_alloc)(int), int flags)
221{
222 unsigned long next;
223 pmd_t *pmdp;
224
225 pmdp = pmd_set_fixmap_offset(pudp, addr);
226 do {
227 pmd_t old_pmd = READ_ONCE(*pmdp);
228
229 next = pmd_addr_end(addr, end);
230
231
232 if (((addr | next | phys) & ~PMD_MASK) == 0 &&
233 (flags & NO_BLOCK_MAPPINGS) == 0) {
234 pmd_set_huge(pmdp, phys, prot);
235
236
237
238
239
240 BUG_ON(!pgattr_change_is_safe(pmd_val(old_pmd),
241 READ_ONCE(pmd_val(*pmdp))));
242 } else {
243 alloc_init_cont_pte(pmdp, addr, next, phys, prot,
244 pgtable_alloc, flags);
245
246 BUG_ON(pmd_val(old_pmd) != 0 &&
247 pmd_val(old_pmd) != READ_ONCE(pmd_val(*pmdp)));
248 }
249 phys += next - addr;
250 } while (pmdp++, addr = next, addr != end);
251
252 pmd_clear_fixmap();
253}
254
255static void alloc_init_cont_pmd(pud_t *pudp, unsigned long addr,
256 unsigned long end, phys_addr_t phys,
257 pgprot_t prot,
258 phys_addr_t (*pgtable_alloc)(int), int flags)
259{
260 unsigned long next;
261 pud_t pud = READ_ONCE(*pudp);
262
263
264
265
266 BUG_ON(pud_sect(pud));
267 if (pud_none(pud)) {
268 pudval_t pudval = PUD_TYPE_TABLE | PUD_TABLE_UXN;
269 phys_addr_t pmd_phys;
270
271 if (flags & NO_EXEC_MAPPINGS)
272 pudval |= PUD_TABLE_PXN;
273 BUG_ON(!pgtable_alloc);
274 pmd_phys = pgtable_alloc(PMD_SHIFT);
275 __pud_populate(pudp, pmd_phys, pudval);
276 pud = READ_ONCE(*pudp);
277 }
278 BUG_ON(pud_bad(pud));
279
280 do {
281 pgprot_t __prot = prot;
282
283 next = pmd_cont_addr_end(addr, end);
284
285
286 if ((((addr | next | phys) & ~CONT_PMD_MASK) == 0) &&
287 (flags & NO_CONT_MAPPINGS) == 0)
288 __prot = __pgprot(pgprot_val(prot) | PTE_CONT);
289
290 init_pmd(pudp, addr, next, phys, __prot, pgtable_alloc, flags);
291
292 phys += next - addr;
293 } while (addr = next, addr != end);
294}
295
296static inline bool use_1G_block(unsigned long addr, unsigned long next,
297 unsigned long phys)
298{
299 if (PAGE_SHIFT != 12)
300 return false;
301
302 if (((addr | next | phys) & ~PUD_MASK) != 0)
303 return false;
304
305 return true;
306}
307
308static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end,
309 phys_addr_t phys, pgprot_t prot,
310 phys_addr_t (*pgtable_alloc)(int),
311 int flags)
312{
313 unsigned long next;
314 pud_t *pudp;
315 p4d_t *p4dp = p4d_offset(pgdp, addr);
316 p4d_t p4d = READ_ONCE(*p4dp);
317
318 if (p4d_none(p4d)) {
319 p4dval_t p4dval = P4D_TYPE_TABLE | P4D_TABLE_UXN;
320 phys_addr_t pud_phys;
321
322 if (flags & NO_EXEC_MAPPINGS)
323 p4dval |= P4D_TABLE_PXN;
324 BUG_ON(!pgtable_alloc);
325 pud_phys = pgtable_alloc(PUD_SHIFT);
326 __p4d_populate(p4dp, pud_phys, p4dval);
327 p4d = READ_ONCE(*p4dp);
328 }
329 BUG_ON(p4d_bad(p4d));
330
331 pudp = pud_set_fixmap_offset(p4dp, addr);
332 do {
333 pud_t old_pud = READ_ONCE(*pudp);
334
335 next = pud_addr_end(addr, end);
336
337
338
339
340 if (use_1G_block(addr, next, phys) &&
341 (flags & NO_BLOCK_MAPPINGS) == 0) {
342 pud_set_huge(pudp, phys, prot);
343
344
345
346
347
348 BUG_ON(!pgattr_change_is_safe(pud_val(old_pud),
349 READ_ONCE(pud_val(*pudp))));
350 } else {
351 alloc_init_cont_pmd(pudp, addr, next, phys, prot,
352 pgtable_alloc, flags);
353
354 BUG_ON(pud_val(old_pud) != 0 &&
355 pud_val(old_pud) != READ_ONCE(pud_val(*pudp)));
356 }
357 phys += next - addr;
358 } while (pudp++, addr = next, addr != end);
359
360 pud_clear_fixmap();
361}
362
363static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
364 unsigned long virt, phys_addr_t size,
365 pgprot_t prot,
366 phys_addr_t (*pgtable_alloc)(int),
367 int flags)
368{
369 unsigned long addr, end, next;
370 pgd_t *pgdp = pgd_offset_pgd(pgdir, virt);
371
372
373
374
375
376 if (WARN_ON((phys ^ virt) & ~PAGE_MASK))
377 return;
378
379 phys &= PAGE_MASK;
380 addr = virt & PAGE_MASK;
381 end = PAGE_ALIGN(virt + size);
382
383 do {
384 next = pgd_addr_end(addr, end);
385 alloc_init_pud(pgdp, addr, next, phys, prot, pgtable_alloc,
386 flags);
387 phys += next - addr;
388 } while (pgdp++, addr = next, addr != end);
389}
390
391static phys_addr_t __pgd_pgtable_alloc(int shift)
392{
393 void *ptr = (void *)__get_free_page(GFP_PGTABLE_KERNEL);
394 BUG_ON(!ptr);
395
396
397 dsb(ishst);
398 return __pa(ptr);
399}
400
401static phys_addr_t pgd_pgtable_alloc(int shift)
402{
403 phys_addr_t pa = __pgd_pgtable_alloc(shift);
404
405
406
407
408
409
410
411
412
413 if (shift == PAGE_SHIFT)
414 BUG_ON(!pgtable_pte_page_ctor(phys_to_page(pa)));
415 else if (shift == PMD_SHIFT)
416 BUG_ON(!pgtable_pmd_page_ctor(phys_to_page(pa)));
417
418 return pa;
419}
420
421
422
423
424
425
426static void __init create_mapping_noalloc(phys_addr_t phys, unsigned long virt,
427 phys_addr_t size, pgprot_t prot)
428{
429 if ((virt >= PAGE_END) && (virt < VMALLOC_START)) {
430 pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n",
431 &phys, virt);
432 return;
433 }
434 __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL,
435 NO_CONT_MAPPINGS);
436}
437
438void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
439 unsigned long virt, phys_addr_t size,
440 pgprot_t prot, bool page_mappings_only)
441{
442 int flags = 0;
443
444 BUG_ON(mm == &init_mm);
445
446 if (page_mappings_only)
447 flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
448
449 __create_pgd_mapping(mm->pgd, phys, virt, size, prot,
450 pgd_pgtable_alloc, flags);
451}
452
453static void update_mapping_prot(phys_addr_t phys, unsigned long virt,
454 phys_addr_t size, pgprot_t prot)
455{
456 if ((virt >= PAGE_END) && (virt < VMALLOC_START)) {
457 pr_warn("BUG: not updating mapping for %pa at 0x%016lx - outside kernel range\n",
458 &phys, virt);
459 return;
460 }
461
462 __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL,
463 NO_CONT_MAPPINGS);
464
465
466 flush_tlb_kernel_range(virt, virt + size);
467}
468
469static void __init __map_memblock(pgd_t *pgdp, phys_addr_t start,
470 phys_addr_t end, pgprot_t prot, int flags)
471{
472 __create_pgd_mapping(pgdp, start, __phys_to_virt(start), end - start,
473 prot, early_pgtable_alloc, flags);
474}
475
476void __init mark_linear_text_alias_ro(void)
477{
478
479
480
481 update_mapping_prot(__pa_symbol(_stext), (unsigned long)lm_alias(_stext),
482 (unsigned long)__init_begin - (unsigned long)_stext,
483 PAGE_KERNEL_RO);
484}
485
486static bool crash_mem_map __initdata;
487
488static int __init enable_crash_mem_map(char *arg)
489{
490
491
492
493
494
495 crash_mem_map = true;
496
497 return 0;
498}
499early_param("crashkernel", enable_crash_mem_map);
500
501static void __init map_mem(pgd_t *pgdp)
502{
503 static const u64 direct_map_end = _PAGE_END(VA_BITS_MIN);
504 phys_addr_t kernel_start = __pa_symbol(_stext);
505 phys_addr_t kernel_end = __pa_symbol(__init_begin);
506 phys_addr_t start, end;
507 int flags = NO_EXEC_MAPPINGS;
508 u64 i;
509
510
511
512
513
514
515
516
517 BUILD_BUG_ON(pgd_index(direct_map_end - 1) == pgd_index(direct_map_end));
518
519 if (can_set_direct_map() || crash_mem_map || IS_ENABLED(CONFIG_KFENCE))
520 flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
521
522
523
524
525
526
527
528 memblock_mark_nomap(kernel_start, kernel_end - kernel_start);
529
530
531 for_each_mem_range(i, &start, &end) {
532 if (start >= end)
533 break;
534
535
536
537
538
539 __map_memblock(pgdp, start, end, pgprot_tagged(PAGE_KERNEL),
540 flags);
541 }
542
543
544
545
546
547
548
549
550
551
552
553 __map_memblock(pgdp, kernel_start, kernel_end,
554 PAGE_KERNEL, NO_CONT_MAPPINGS);
555 memblock_clear_nomap(kernel_start, kernel_end - kernel_start);
556}
557
558void mark_rodata_ro(void)
559{
560 unsigned long section_size;
561
562
563
564
565
566 section_size = (unsigned long)__init_begin - (unsigned long)__start_rodata;
567 update_mapping_prot(__pa_symbol(__start_rodata), (unsigned long)__start_rodata,
568 section_size, PAGE_KERNEL_RO);
569
570 debug_checkwx();
571}
572
573static void __init map_kernel_segment(pgd_t *pgdp, void *va_start, void *va_end,
574 pgprot_t prot, struct vm_struct *vma,
575 int flags, unsigned long vm_flags)
576{
577 phys_addr_t pa_start = __pa_symbol(va_start);
578 unsigned long size = va_end - va_start;
579
580 BUG_ON(!PAGE_ALIGNED(pa_start));
581 BUG_ON(!PAGE_ALIGNED(size));
582
583 __create_pgd_mapping(pgdp, pa_start, (unsigned long)va_start, size, prot,
584 early_pgtable_alloc, flags);
585
586 if (!(vm_flags & VM_NO_GUARD))
587 size += PAGE_SIZE;
588
589 vma->addr = va_start;
590 vma->phys_addr = pa_start;
591 vma->size = size;
592 vma->flags = VM_MAP | vm_flags;
593 vma->caller = __builtin_return_address(0);
594
595 vm_area_add_early(vma);
596}
597
598static int __init parse_rodata(char *arg)
599{
600 int ret = strtobool(arg, &rodata_enabled);
601 if (!ret) {
602 rodata_full = false;
603 return 0;
604 }
605
606
607 if (strcmp(arg, "full"))
608 return -EINVAL;
609
610 rodata_enabled = true;
611 rodata_full = true;
612 return 0;
613}
614early_param("rodata", parse_rodata);
615
616#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
617static int __init map_entry_trampoline(void)
618{
619 pgprot_t prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;
620 phys_addr_t pa_start = __pa_symbol(__entry_tramp_text_start);
621
622
623 pgprot_val(prot) &= ~PTE_NG;
624
625
626 memset(tramp_pg_dir, 0, PGD_SIZE);
627 __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE,
628 prot, __pgd_pgtable_alloc, 0);
629
630
631 __set_fixmap(FIX_ENTRY_TRAMP_TEXT, pa_start, prot);
632 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
633 extern char __entry_tramp_data_start[];
634
635 __set_fixmap(FIX_ENTRY_TRAMP_DATA,
636 __pa_symbol(__entry_tramp_data_start),
637 PAGE_KERNEL_RO);
638 }
639
640 return 0;
641}
642core_initcall(map_entry_trampoline);
643#endif
644
645
646
647
648
649static bool arm64_early_this_cpu_has_bti(void)
650{
651 u64 pfr1;
652
653 if (!IS_ENABLED(CONFIG_ARM64_BTI_KERNEL))
654 return false;
655
656 pfr1 = __read_sysreg_by_encoding(SYS_ID_AA64PFR1_EL1);
657 return cpuid_feature_extract_unsigned_field(pfr1,
658 ID_AA64PFR1_BT_SHIFT);
659}
660
661
662
663
664static void __init map_kernel(pgd_t *pgdp)
665{
666 static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_inittext,
667 vmlinux_initdata, vmlinux_data;
668
669
670
671
672
673
674 pgprot_t text_prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;
675
676
677
678
679
680
681 if (arm64_early_this_cpu_has_bti())
682 text_prot = __pgprot_modify(text_prot, PTE_GP, PTE_GP);
683
684
685
686
687
688 map_kernel_segment(pgdp, _stext, _etext, text_prot, &vmlinux_text, 0,
689 VM_NO_GUARD);
690 map_kernel_segment(pgdp, __start_rodata, __inittext_begin, PAGE_KERNEL,
691 &vmlinux_rodata, NO_CONT_MAPPINGS, VM_NO_GUARD);
692 map_kernel_segment(pgdp, __inittext_begin, __inittext_end, text_prot,
693 &vmlinux_inittext, 0, VM_NO_GUARD);
694 map_kernel_segment(pgdp, __initdata_begin, __initdata_end, PAGE_KERNEL,
695 &vmlinux_initdata, 0, VM_NO_GUARD);
696 map_kernel_segment(pgdp, _data, _end, PAGE_KERNEL, &vmlinux_data, 0, 0);
697
698 if (!READ_ONCE(pgd_val(*pgd_offset_pgd(pgdp, FIXADDR_START)))) {
699
700
701
702
703
704 set_pgd(pgd_offset_pgd(pgdp, FIXADDR_START),
705 READ_ONCE(*pgd_offset_k(FIXADDR_START)));
706 } else if (CONFIG_PGTABLE_LEVELS > 3) {
707 pgd_t *bm_pgdp;
708 p4d_t *bm_p4dp;
709 pud_t *bm_pudp;
710
711
712
713
714
715
716 BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES));
717 bm_pgdp = pgd_offset_pgd(pgdp, FIXADDR_START);
718 bm_p4dp = p4d_offset(bm_pgdp, FIXADDR_START);
719 bm_pudp = pud_set_fixmap_offset(bm_p4dp, FIXADDR_START);
720 pud_populate(&init_mm, bm_pudp, lm_alias(bm_pmd));
721 pud_clear_fixmap();
722 } else {
723 BUG();
724 }
725
726 kasan_copy_shadow(pgdp);
727}
728
729void __init paging_init(void)
730{
731 pgd_t *pgdp = pgd_set_fixmap(__pa_symbol(swapper_pg_dir));
732
733 map_kernel(pgdp);
734 map_mem(pgdp);
735
736 pgd_clear_fixmap();
737
738 cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
739 init_mm.pgd = swapper_pg_dir;
740
741 memblock_free(__pa_symbol(init_pg_dir),
742 __pa_symbol(init_pg_end) - __pa_symbol(init_pg_dir));
743
744 memblock_allow_resize();
745}
746
747
748
749
750int kern_addr_valid(unsigned long addr)
751{
752 pgd_t *pgdp;
753 p4d_t *p4dp;
754 pud_t *pudp, pud;
755 pmd_t *pmdp, pmd;
756 pte_t *ptep, pte;
757
758 addr = arch_kasan_reset_tag(addr);
759 if ((((long)addr) >> VA_BITS) != -1UL)
760 return 0;
761
762 pgdp = pgd_offset_k(addr);
763 if (pgd_none(READ_ONCE(*pgdp)))
764 return 0;
765
766 p4dp = p4d_offset(pgdp, addr);
767 if (p4d_none(READ_ONCE(*p4dp)))
768 return 0;
769
770 pudp = pud_offset(p4dp, addr);
771 pud = READ_ONCE(*pudp);
772 if (pud_none(pud))
773 return 0;
774
775 if (pud_sect(pud))
776 return pfn_valid(pud_pfn(pud));
777
778 pmdp = pmd_offset(pudp, addr);
779 pmd = READ_ONCE(*pmdp);
780 if (pmd_none(pmd))
781 return 0;
782
783 if (pmd_sect(pmd))
784 return pfn_valid(pmd_pfn(pmd));
785
786 ptep = pte_offset_kernel(pmdp, addr);
787 pte = READ_ONCE(*ptep);
788 if (pte_none(pte))
789 return 0;
790
791 return pfn_valid(pte_pfn(pte));
792}
793
794#ifdef CONFIG_MEMORY_HOTPLUG
795static void free_hotplug_page_range(struct page *page, size_t size,
796 struct vmem_altmap *altmap)
797{
798 if (altmap) {
799 vmem_altmap_free(altmap, size >> PAGE_SHIFT);
800 } else {
801 WARN_ON(PageReserved(page));
802 free_pages((unsigned long)page_address(page), get_order(size));
803 }
804}
805
806static void free_hotplug_pgtable_page(struct page *page)
807{
808 free_hotplug_page_range(page, PAGE_SIZE, NULL);
809}
810
811static bool pgtable_range_aligned(unsigned long start, unsigned long end,
812 unsigned long floor, unsigned long ceiling,
813 unsigned long mask)
814{
815 start &= mask;
816 if (start < floor)
817 return false;
818
819 if (ceiling) {
820 ceiling &= mask;
821 if (!ceiling)
822 return false;
823 }
824
825 if (end - 1 > ceiling - 1)
826 return false;
827 return true;
828}
829
830static void unmap_hotplug_pte_range(pmd_t *pmdp, unsigned long addr,
831 unsigned long end, bool free_mapped,
832 struct vmem_altmap *altmap)
833{
834 pte_t *ptep, pte;
835
836 do {
837 ptep = pte_offset_kernel(pmdp, addr);
838 pte = READ_ONCE(*ptep);
839 if (pte_none(pte))
840 continue;
841
842 WARN_ON(!pte_present(pte));
843 pte_clear(&init_mm, addr, ptep);
844 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
845 if (free_mapped)
846 free_hotplug_page_range(pte_page(pte),
847 PAGE_SIZE, altmap);
848 } while (addr += PAGE_SIZE, addr < end);
849}
850
851static void unmap_hotplug_pmd_range(pud_t *pudp, unsigned long addr,
852 unsigned long end, bool free_mapped,
853 struct vmem_altmap *altmap)
854{
855 unsigned long next;
856 pmd_t *pmdp, pmd;
857
858 do {
859 next = pmd_addr_end(addr, end);
860 pmdp = pmd_offset(pudp, addr);
861 pmd = READ_ONCE(*pmdp);
862 if (pmd_none(pmd))
863 continue;
864
865 WARN_ON(!pmd_present(pmd));
866 if (pmd_sect(pmd)) {
867 pmd_clear(pmdp);
868
869
870
871
872
873 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
874 if (free_mapped)
875 free_hotplug_page_range(pmd_page(pmd),
876 PMD_SIZE, altmap);
877 continue;
878 }
879 WARN_ON(!pmd_table(pmd));
880 unmap_hotplug_pte_range(pmdp, addr, next, free_mapped, altmap);
881 } while (addr = next, addr < end);
882}
883
884static void unmap_hotplug_pud_range(p4d_t *p4dp, unsigned long addr,
885 unsigned long end, bool free_mapped,
886 struct vmem_altmap *altmap)
887{
888 unsigned long next;
889 pud_t *pudp, pud;
890
891 do {
892 next = pud_addr_end(addr, end);
893 pudp = pud_offset(p4dp, addr);
894 pud = READ_ONCE(*pudp);
895 if (pud_none(pud))
896 continue;
897
898 WARN_ON(!pud_present(pud));
899 if (pud_sect(pud)) {
900 pud_clear(pudp);
901
902
903
904
905
906 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
907 if (free_mapped)
908 free_hotplug_page_range(pud_page(pud),
909 PUD_SIZE, altmap);
910 continue;
911 }
912 WARN_ON(!pud_table(pud));
913 unmap_hotplug_pmd_range(pudp, addr, next, free_mapped, altmap);
914 } while (addr = next, addr < end);
915}
916
917static void unmap_hotplug_p4d_range(pgd_t *pgdp, unsigned long addr,
918 unsigned long end, bool free_mapped,
919 struct vmem_altmap *altmap)
920{
921 unsigned long next;
922 p4d_t *p4dp, p4d;
923
924 do {
925 next = p4d_addr_end(addr, end);
926 p4dp = p4d_offset(pgdp, addr);
927 p4d = READ_ONCE(*p4dp);
928 if (p4d_none(p4d))
929 continue;
930
931 WARN_ON(!p4d_present(p4d));
932 unmap_hotplug_pud_range(p4dp, addr, next, free_mapped, altmap);
933 } while (addr = next, addr < end);
934}
935
936static void unmap_hotplug_range(unsigned long addr, unsigned long end,
937 bool free_mapped, struct vmem_altmap *altmap)
938{
939 unsigned long next;
940 pgd_t *pgdp, pgd;
941
942
943
944
945
946
947
948 WARN_ON(!free_mapped && altmap);
949
950 do {
951 next = pgd_addr_end(addr, end);
952 pgdp = pgd_offset_k(addr);
953 pgd = READ_ONCE(*pgdp);
954 if (pgd_none(pgd))
955 continue;
956
957 WARN_ON(!pgd_present(pgd));
958 unmap_hotplug_p4d_range(pgdp, addr, next, free_mapped, altmap);
959 } while (addr = next, addr < end);
960}
961
962static void free_empty_pte_table(pmd_t *pmdp, unsigned long addr,
963 unsigned long end, unsigned long floor,
964 unsigned long ceiling)
965{
966 pte_t *ptep, pte;
967 unsigned long i, start = addr;
968
969 do {
970 ptep = pte_offset_kernel(pmdp, addr);
971 pte = READ_ONCE(*ptep);
972
973
974
975
976
977 WARN_ON(!pte_none(pte));
978 } while (addr += PAGE_SIZE, addr < end);
979
980 if (!pgtable_range_aligned(start, end, floor, ceiling, PMD_MASK))
981 return;
982
983
984
985
986
987
988 ptep = pte_offset_kernel(pmdp, 0UL);
989 for (i = 0; i < PTRS_PER_PTE; i++) {
990 if (!pte_none(READ_ONCE(ptep[i])))
991 return;
992 }
993
994 pmd_clear(pmdp);
995 __flush_tlb_kernel_pgtable(start);
996 free_hotplug_pgtable_page(virt_to_page(ptep));
997}
998
999static void free_empty_pmd_table(pud_t *pudp, unsigned long addr,
1000 unsigned long end, unsigned long floor,
1001 unsigned long ceiling)
1002{
1003 pmd_t *pmdp, pmd;
1004 unsigned long i, next, start = addr;
1005
1006 do {
1007 next = pmd_addr_end(addr, end);
1008 pmdp = pmd_offset(pudp, addr);
1009 pmd = READ_ONCE(*pmdp);
1010 if (pmd_none(pmd))
1011 continue;
1012
1013 WARN_ON(!pmd_present(pmd) || !pmd_table(pmd) || pmd_sect(pmd));
1014 free_empty_pte_table(pmdp, addr, next, floor, ceiling);
1015 } while (addr = next, addr < end);
1016
1017 if (CONFIG_PGTABLE_LEVELS <= 2)
1018 return;
1019
1020 if (!pgtable_range_aligned(start, end, floor, ceiling, PUD_MASK))
1021 return;
1022
1023
1024
1025
1026
1027
1028 pmdp = pmd_offset(pudp, 0UL);
1029 for (i = 0; i < PTRS_PER_PMD; i++) {
1030 if (!pmd_none(READ_ONCE(pmdp[i])))
1031 return;
1032 }
1033
1034 pud_clear(pudp);
1035 __flush_tlb_kernel_pgtable(start);
1036 free_hotplug_pgtable_page(virt_to_page(pmdp));
1037}
1038
1039static void free_empty_pud_table(p4d_t *p4dp, unsigned long addr,
1040 unsigned long end, unsigned long floor,
1041 unsigned long ceiling)
1042{
1043 pud_t *pudp, pud;
1044 unsigned long i, next, start = addr;
1045
1046 do {
1047 next = pud_addr_end(addr, end);
1048 pudp = pud_offset(p4dp, addr);
1049 pud = READ_ONCE(*pudp);
1050 if (pud_none(pud))
1051 continue;
1052
1053 WARN_ON(!pud_present(pud) || !pud_table(pud) || pud_sect(pud));
1054 free_empty_pmd_table(pudp, addr, next, floor, ceiling);
1055 } while (addr = next, addr < end);
1056
1057 if (CONFIG_PGTABLE_LEVELS <= 3)
1058 return;
1059
1060 if (!pgtable_range_aligned(start, end, floor, ceiling, PGDIR_MASK))
1061 return;
1062
1063
1064
1065
1066
1067
1068 pudp = pud_offset(p4dp, 0UL);
1069 for (i = 0; i < PTRS_PER_PUD; i++) {
1070 if (!pud_none(READ_ONCE(pudp[i])))
1071 return;
1072 }
1073
1074 p4d_clear(p4dp);
1075 __flush_tlb_kernel_pgtable(start);
1076 free_hotplug_pgtable_page(virt_to_page(pudp));
1077}
1078
1079static void free_empty_p4d_table(pgd_t *pgdp, unsigned long addr,
1080 unsigned long end, unsigned long floor,
1081 unsigned long ceiling)
1082{
1083 unsigned long next;
1084 p4d_t *p4dp, p4d;
1085
1086 do {
1087 next = p4d_addr_end(addr, end);
1088 p4dp = p4d_offset(pgdp, addr);
1089 p4d = READ_ONCE(*p4dp);
1090 if (p4d_none(p4d))
1091 continue;
1092
1093 WARN_ON(!p4d_present(p4d));
1094 free_empty_pud_table(p4dp, addr, next, floor, ceiling);
1095 } while (addr = next, addr < end);
1096}
1097
1098static void free_empty_tables(unsigned long addr, unsigned long end,
1099 unsigned long floor, unsigned long ceiling)
1100{
1101 unsigned long next;
1102 pgd_t *pgdp, pgd;
1103
1104 do {
1105 next = pgd_addr_end(addr, end);
1106 pgdp = pgd_offset_k(addr);
1107 pgd = READ_ONCE(*pgdp);
1108 if (pgd_none(pgd))
1109 continue;
1110
1111 WARN_ON(!pgd_present(pgd));
1112 free_empty_p4d_table(pgdp, addr, next, floor, ceiling);
1113 } while (addr = next, addr < end);
1114}
1115#endif
1116
1117#if !ARM64_KERNEL_USES_PMD_MAPS
1118int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1119 struct vmem_altmap *altmap)
1120{
1121 WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END));
1122 return vmemmap_populate_basepages(start, end, node, altmap);
1123}
1124#else
1125int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1126 struct vmem_altmap *altmap)
1127{
1128 unsigned long addr = start;
1129 unsigned long next;
1130 pgd_t *pgdp;
1131 p4d_t *p4dp;
1132 pud_t *pudp;
1133 pmd_t *pmdp;
1134
1135 WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END));
1136 do {
1137 next = pmd_addr_end(addr, end);
1138
1139 pgdp = vmemmap_pgd_populate(addr, node);
1140 if (!pgdp)
1141 return -ENOMEM;
1142
1143 p4dp = vmemmap_p4d_populate(pgdp, addr, node);
1144 if (!p4dp)
1145 return -ENOMEM;
1146
1147 pudp = vmemmap_pud_populate(p4dp, addr, node);
1148 if (!pudp)
1149 return -ENOMEM;
1150
1151 pmdp = pmd_offset(pudp, addr);
1152 if (pmd_none(READ_ONCE(*pmdp))) {
1153 void *p = NULL;
1154
1155 p = vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
1156 if (!p) {
1157 if (vmemmap_populate_basepages(addr, next, node, altmap))
1158 return -ENOMEM;
1159 continue;
1160 }
1161
1162 pmd_set_huge(pmdp, __pa(p), __pgprot(PROT_SECT_NORMAL));
1163 } else
1164 vmemmap_verify((pte_t *)pmdp, node, addr, next);
1165 } while (addr = next, addr != end);
1166
1167 return 0;
1168}
1169#endif
1170
1171#ifdef CONFIG_MEMORY_HOTPLUG
1172void vmemmap_free(unsigned long start, unsigned long end,
1173 struct vmem_altmap *altmap)
1174{
1175 WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END));
1176
1177 unmap_hotplug_range(start, end, true, altmap);
1178 free_empty_tables(start, end, VMEMMAP_START, VMEMMAP_END);
1179}
1180#endif
1181
1182static inline pud_t *fixmap_pud(unsigned long addr)
1183{
1184 pgd_t *pgdp = pgd_offset_k(addr);
1185 p4d_t *p4dp = p4d_offset(pgdp, addr);
1186 p4d_t p4d = READ_ONCE(*p4dp);
1187
1188 BUG_ON(p4d_none(p4d) || p4d_bad(p4d));
1189
1190 return pud_offset_kimg(p4dp, addr);
1191}
1192
1193static inline pmd_t *fixmap_pmd(unsigned long addr)
1194{
1195 pud_t *pudp = fixmap_pud(addr);
1196 pud_t pud = READ_ONCE(*pudp);
1197
1198 BUG_ON(pud_none(pud) || pud_bad(pud));
1199
1200 return pmd_offset_kimg(pudp, addr);
1201}
1202
1203static inline pte_t *fixmap_pte(unsigned long addr)
1204{
1205 return &bm_pte[pte_index(addr)];
1206}
1207
1208
1209
1210
1211
1212
1213
1214void __init early_fixmap_init(void)
1215{
1216 pgd_t *pgdp;
1217 p4d_t *p4dp, p4d;
1218 pud_t *pudp;
1219 pmd_t *pmdp;
1220 unsigned long addr = FIXADDR_START;
1221
1222 pgdp = pgd_offset_k(addr);
1223 p4dp = p4d_offset(pgdp, addr);
1224 p4d = READ_ONCE(*p4dp);
1225 if (CONFIG_PGTABLE_LEVELS > 3 &&
1226 !(p4d_none(p4d) || p4d_page_paddr(p4d) == __pa_symbol(bm_pud))) {
1227
1228
1229
1230
1231
1232 BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES));
1233 pudp = pud_offset_kimg(p4dp, addr);
1234 } else {
1235 if (p4d_none(p4d))
1236 __p4d_populate(p4dp, __pa_symbol(bm_pud), P4D_TYPE_TABLE);
1237 pudp = fixmap_pud(addr);
1238 }
1239 if (pud_none(READ_ONCE(*pudp)))
1240 __pud_populate(pudp, __pa_symbol(bm_pmd), PUD_TYPE_TABLE);
1241 pmdp = fixmap_pmd(addr);
1242 __pmd_populate(pmdp, __pa_symbol(bm_pte), PMD_TYPE_TABLE);
1243
1244
1245
1246
1247
1248 BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
1249 != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
1250
1251 if ((pmdp != fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)))
1252 || pmdp != fixmap_pmd(fix_to_virt(FIX_BTMAP_END))) {
1253 WARN_ON(1);
1254 pr_warn("pmdp %p != %p, %p\n",
1255 pmdp, fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)),
1256 fixmap_pmd(fix_to_virt(FIX_BTMAP_END)));
1257 pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
1258 fix_to_virt(FIX_BTMAP_BEGIN));
1259 pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n",
1260 fix_to_virt(FIX_BTMAP_END));
1261
1262 pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
1263 pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN);
1264 }
1265}
1266
1267
1268
1269
1270
1271void __set_fixmap(enum fixed_addresses idx,
1272 phys_addr_t phys, pgprot_t flags)
1273{
1274 unsigned long addr = __fix_to_virt(idx);
1275 pte_t *ptep;
1276
1277 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
1278
1279 ptep = fixmap_pte(addr);
1280
1281 if (pgprot_val(flags)) {
1282 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, flags));
1283 } else {
1284 pte_clear(&init_mm, addr, ptep);
1285 flush_tlb_kernel_range(addr, addr+PAGE_SIZE);
1286 }
1287}
1288
1289void *__init fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot)
1290{
1291 const u64 dt_virt_base = __fix_to_virt(FIX_FDT);
1292 int offset;
1293 void *dt_virt;
1294
1295
1296
1297
1298
1299
1300
1301
1302 BUILD_BUG_ON(MIN_FDT_ALIGN < 8);
1303 if (!dt_phys || dt_phys % MIN_FDT_ALIGN)
1304 return NULL;
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316 BUILD_BUG_ON(dt_virt_base % SZ_2M);
1317
1318 BUILD_BUG_ON(__fix_to_virt(FIX_FDT_END) >> SWAPPER_TABLE_SHIFT !=
1319 __fix_to_virt(FIX_BTMAP_BEGIN) >> SWAPPER_TABLE_SHIFT);
1320
1321 offset = dt_phys % SWAPPER_BLOCK_SIZE;
1322 dt_virt = (void *)dt_virt_base + offset;
1323
1324
1325 create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE),
1326 dt_virt_base, SWAPPER_BLOCK_SIZE, prot);
1327
1328 if (fdt_magic(dt_virt) != FDT_MAGIC)
1329 return NULL;
1330
1331 *size = fdt_totalsize(dt_virt);
1332 if (*size > MAX_FDT_SIZE)
1333 return NULL;
1334
1335 if (offset + *size > SWAPPER_BLOCK_SIZE)
1336 create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE), dt_virt_base,
1337 round_up(offset + *size, SWAPPER_BLOCK_SIZE), prot);
1338
1339 return dt_virt;
1340}
1341
1342int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot)
1343{
1344 pud_t new_pud = pfn_pud(__phys_to_pfn(phys), mk_pud_sect_prot(prot));
1345
1346
1347 if (!pgattr_change_is_safe(READ_ONCE(pud_val(*pudp)),
1348 pud_val(new_pud)))
1349 return 0;
1350
1351 VM_BUG_ON(phys & ~PUD_MASK);
1352 set_pud(pudp, new_pud);
1353 return 1;
1354}
1355
1356int pmd_set_huge(pmd_t *pmdp, phys_addr_t phys, pgprot_t prot)
1357{
1358 pmd_t new_pmd = pfn_pmd(__phys_to_pfn(phys), mk_pmd_sect_prot(prot));
1359
1360
1361 if (!pgattr_change_is_safe(READ_ONCE(pmd_val(*pmdp)),
1362 pmd_val(new_pmd)))
1363 return 0;
1364
1365 VM_BUG_ON(phys & ~PMD_MASK);
1366 set_pmd(pmdp, new_pmd);
1367 return 1;
1368}
1369
1370int pud_clear_huge(pud_t *pudp)
1371{
1372 if (!pud_sect(READ_ONCE(*pudp)))
1373 return 0;
1374 pud_clear(pudp);
1375 return 1;
1376}
1377
1378int pmd_clear_huge(pmd_t *pmdp)
1379{
1380 if (!pmd_sect(READ_ONCE(*pmdp)))
1381 return 0;
1382 pmd_clear(pmdp);
1383 return 1;
1384}
1385
1386int pmd_free_pte_page(pmd_t *pmdp, unsigned long addr)
1387{
1388 pte_t *table;
1389 pmd_t pmd;
1390
1391 pmd = READ_ONCE(*pmdp);
1392
1393 if (!pmd_table(pmd)) {
1394 VM_WARN_ON(1);
1395 return 1;
1396 }
1397
1398 table = pte_offset_kernel(pmdp, addr);
1399 pmd_clear(pmdp);
1400 __flush_tlb_kernel_pgtable(addr);
1401 pte_free_kernel(NULL, table);
1402 return 1;
1403}
1404
1405int pud_free_pmd_page(pud_t *pudp, unsigned long addr)
1406{
1407 pmd_t *table;
1408 pmd_t *pmdp;
1409 pud_t pud;
1410 unsigned long next, end;
1411
1412 pud = READ_ONCE(*pudp);
1413
1414 if (!pud_table(pud)) {
1415 VM_WARN_ON(1);
1416 return 1;
1417 }
1418
1419 table = pmd_offset(pudp, addr);
1420 pmdp = table;
1421 next = addr;
1422 end = addr + PUD_SIZE;
1423 do {
1424 pmd_free_pte_page(pmdp, next);
1425 } while (pmdp++, next += PMD_SIZE, next != end);
1426
1427 pud_clear(pudp);
1428 __flush_tlb_kernel_pgtable(addr);
1429 pmd_free(NULL, table);
1430 return 1;
1431}
1432
1433#ifdef CONFIG_MEMORY_HOTPLUG
1434static void __remove_pgd_mapping(pgd_t *pgdir, unsigned long start, u64 size)
1435{
1436 unsigned long end = start + size;
1437
1438 WARN_ON(pgdir != init_mm.pgd);
1439 WARN_ON((start < PAGE_OFFSET) || (end > PAGE_END));
1440
1441 unmap_hotplug_range(start, end, false, NULL);
1442 free_empty_tables(start, end, PAGE_OFFSET, PAGE_END);
1443}
1444
1445struct range arch_get_mappable_range(void)
1446{
1447 struct range mhp_range;
1448 u64 start_linear_pa = __pa(_PAGE_OFFSET(vabits_actual));
1449 u64 end_linear_pa = __pa(PAGE_END - 1);
1450
1451 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
1452
1453
1454
1455
1456
1457
1458
1459 if (start_linear_pa > end_linear_pa)
1460 start_linear_pa = 0;
1461 }
1462
1463 WARN_ON(start_linear_pa > end_linear_pa);
1464
1465
1466
1467
1468
1469
1470
1471 mhp_range.start = start_linear_pa;
1472 mhp_range.end = end_linear_pa;
1473
1474 return mhp_range;
1475}
1476
1477int arch_add_memory(int nid, u64 start, u64 size,
1478 struct mhp_params *params)
1479{
1480 int ret, flags = NO_EXEC_MAPPINGS;
1481
1482 VM_BUG_ON(!mhp_range_allowed(start, size, true));
1483
1484
1485
1486
1487
1488 if (can_set_direct_map() || IS_ENABLED(CONFIG_KFENCE))
1489 flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
1490
1491 __create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start),
1492 size, params->pgprot, __pgd_pgtable_alloc,
1493 flags);
1494
1495 memblock_clear_nomap(start, size);
1496
1497 ret = __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT,
1498 params);
1499 if (ret)
1500 __remove_pgd_mapping(swapper_pg_dir,
1501 __phys_to_virt(start), size);
1502 return ret;
1503}
1504
1505void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
1506{
1507 unsigned long start_pfn = start >> PAGE_SHIFT;
1508 unsigned long nr_pages = size >> PAGE_SHIFT;
1509
1510 __remove_pages(start_pfn, nr_pages, altmap);
1511 __remove_pgd_mapping(swapper_pg_dir, __phys_to_virt(start), size);
1512}
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523static int prevent_bootmem_remove_notifier(struct notifier_block *nb,
1524 unsigned long action, void *data)
1525{
1526 struct mem_section *ms;
1527 struct memory_notify *arg = data;
1528 unsigned long end_pfn = arg->start_pfn + arg->nr_pages;
1529 unsigned long pfn = arg->start_pfn;
1530
1531 if ((action != MEM_GOING_OFFLINE) && (action != MEM_OFFLINE))
1532 return NOTIFY_OK;
1533
1534 for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
1535 unsigned long start = PFN_PHYS(pfn);
1536 unsigned long end = start + (1UL << PA_SECTION_SHIFT);
1537
1538 ms = __pfn_to_section(pfn);
1539 if (!early_section(ms))
1540 continue;
1541
1542 if (action == MEM_GOING_OFFLINE) {
1543
1544
1545
1546
1547
1548 pr_warn("Boot memory [%lx %lx] offlining attempted\n", start, end);
1549 return NOTIFY_BAD;
1550 } else if (action == MEM_OFFLINE) {
1551
1552
1553
1554
1555
1556
1557
1558 pr_err("Boot memory [%lx %lx] offlined\n", start, end);
1559
1560
1561
1562
1563
1564
1565
1566 return NOTIFY_DONE;
1567 }
1568 }
1569 return NOTIFY_OK;
1570}
1571
1572static struct notifier_block prevent_bootmem_remove_nb = {
1573 .notifier_call = prevent_bootmem_remove_notifier,
1574};
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584static void validate_bootmem_online(void)
1585{
1586 phys_addr_t start, end, addr;
1587 struct mem_section *ms;
1588 u64 i;
1589
1590
1591
1592
1593
1594
1595 if (!IS_ENABLED(CONFIG_DEBUG_VM))
1596 return;
1597
1598 for_each_mem_range(i, &start, &end) {
1599 for (addr = start; addr < end; addr += (1UL << PA_SECTION_SHIFT)) {
1600 ms = __pfn_to_section(PHYS_PFN(addr));
1601
1602
1603
1604
1605
1606 WARN_ON(!early_section(ms));
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616 if (!online_section(ms))
1617 pr_err("Boot memory [%llx %llx] is offline, can be removed\n",
1618 addr, addr + (1UL << PA_SECTION_SHIFT));
1619 }
1620 }
1621}
1622
1623static int __init prevent_bootmem_remove_init(void)
1624{
1625 int ret = 0;
1626
1627 if (!IS_ENABLED(CONFIG_MEMORY_HOTREMOVE))
1628 return ret;
1629
1630 validate_bootmem_online();
1631 ret = register_memory_notifier(&prevent_bootmem_remove_nb);
1632 if (ret)
1633 pr_err("%s: Notifier registration failed %d\n", __func__, ret);
1634
1635 return ret;
1636}
1637early_initcall(prevent_bootmem_remove_init);
1638#endif
1639