2 * Based on arch/arm/mm/mmu.c
4 * Copyright (C) 1995-2005 Russell King
5 * Copyright (C) 2012 ARM Ltd.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #include <linux/cache.h>
21 #include <linux/export.h>
22 #include <linux/kernel.h>
23 #include <linux/errno.h>
24 #include <linux/init.h>
25 #include <linux/ioport.h>
26 #include <linux/kexec.h>
27 #include <linux/libfdt.h>
28 #include <linux/mman.h>
29 #include <linux/nodemask.h>
30 #include <linux/memblock.h>
34 #include <linux/vmalloc.h>
36 #include <asm/barrier.h>
37 #include <asm/cputype.h>
38 #include <asm/fixmap.h>
39 #include <asm/kasan.h>
40 #include <asm/kernel-pgtable.h>
41 #include <asm/sections.h>
42 #include <asm/setup.h>
43 #include <asm/sizes.h>
45 #include <asm/memblock.h>
46 #include <asm/mmu_context.h>
47 #include <asm/ptdump.h>
49 #define NO_BLOCK_MAPPINGS BIT(0)
50 #define NO_CONT_MAPPINGS BIT(1)
52 u64 idmap_t0sz = TCR_T0SZ(VA_BITS);
54 u64 kimage_voffset __ro_after_init;
55 EXPORT_SYMBOL(kimage_voffset);
58 * Empty_zero_page is a special page that is used for zero-initialized data
61 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
62 EXPORT_SYMBOL(empty_zero_page);
64 static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss;
65 static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss __maybe_unused;
66 static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss __maybe_unused;
68 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
69 unsigned long size, pgprot_t vma_prot)
72 return pgprot_noncached(vma_prot);
73 else if (file->f_flags & O_SYNC)
74 return pgprot_writecombine(vma_prot);
77 EXPORT_SYMBOL(phys_mem_access_prot);
79 static phys_addr_t __init early_pgtable_alloc(void)
84 phys = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
87 * The FIX_{PGD,PUD,PMD} slots may be in active use, but the FIX_PTE
88 * slot will be free, so we can (ab)use the FIX_PTE slot to initialise
91 ptr = pte_set_fixmap(phys);
93 memset(ptr, 0, PAGE_SIZE);
96 * Implicit barriers also ensure the zeroed page is visible to the page
104 static bool pgattr_change_is_safe(u64 old, u64 new)
107 * The following mapping attributes may be updated in live
108 * kernel mappings without the need for break-before-make.
110 static const pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE;
112 /* creating or taking down mappings is always safe */
113 if (old == 0 || new == 0)
116 /* live contiguous mappings may not be manipulated at all */
117 if ((old | new) & PTE_CONT)
120 return ((old ^ new) & ~mask) == 0;
123 static void init_pte(pmd_t *pmd, unsigned long addr, unsigned long end,
124 phys_addr_t phys, pgprot_t prot)
128 pte = pte_set_fixmap_offset(pmd, addr);
130 pte_t old_pte = *pte;
132 set_pte(pte, pfn_pte(__phys_to_pfn(phys), prot));
135 * After the PTE entry has been populated once, we
136 * only allow updates to the permission attributes.
138 BUG_ON(!pgattr_change_is_safe(pte_val(old_pte), pte_val(*pte)));
141 } while (pte++, addr += PAGE_SIZE, addr != end);
146 static void alloc_init_cont_pte(pmd_t *pmd, unsigned long addr,
147 unsigned long end, phys_addr_t phys,
149 phys_addr_t (*pgtable_alloc)(void),
154 BUG_ON(pmd_sect(*pmd));
155 if (pmd_none(*pmd)) {
156 phys_addr_t pte_phys;
157 BUG_ON(!pgtable_alloc);
158 pte_phys = pgtable_alloc();
159 __pmd_populate(pmd, pte_phys, PMD_TYPE_TABLE);
161 BUG_ON(pmd_bad(*pmd));
164 pgprot_t __prot = prot;
166 next = pte_cont_addr_end(addr, end);
168 /* use a contiguous mapping if the range is suitably aligned */
169 if ((((addr | next | phys) & ~CONT_PTE_MASK) == 0) &&
170 (flags & NO_CONT_MAPPINGS) == 0)
171 __prot = __pgprot(pgprot_val(prot) | PTE_CONT);
173 init_pte(pmd, addr, next, phys, __prot);
176 } while (addr = next, addr != end);
179 static void init_pmd(pud_t *pud, unsigned long addr, unsigned long end,
180 phys_addr_t phys, pgprot_t prot,
181 phys_addr_t (*pgtable_alloc)(void), int flags)
186 pmd = pmd_set_fixmap_offset(pud, addr);
188 pmd_t old_pmd = *pmd;
190 next = pmd_addr_end(addr, end);
192 /* try section mapping first */
193 if (((addr | next | phys) & ~SECTION_MASK) == 0 &&
194 (flags & NO_BLOCK_MAPPINGS) == 0) {
195 pmd_set_huge(pmd, phys, prot);
198 * After the PMD entry has been populated once, we
199 * only allow updates to the permission attributes.
201 BUG_ON(!pgattr_change_is_safe(pmd_val(old_pmd),
204 alloc_init_cont_pte(pmd, addr, next, phys, prot,
205 pgtable_alloc, flags);
207 BUG_ON(pmd_val(old_pmd) != 0 &&
208 pmd_val(old_pmd) != pmd_val(*pmd));
211 } while (pmd++, addr = next, addr != end);
216 static void alloc_init_cont_pmd(pud_t *pud, unsigned long addr,
217 unsigned long end, phys_addr_t phys,
219 phys_addr_t (*pgtable_alloc)(void), int flags)
224 * Check for initial section mappings in the pgd/pud.
226 BUG_ON(pud_sect(*pud));
227 if (pud_none(*pud)) {
228 phys_addr_t pmd_phys;
229 BUG_ON(!pgtable_alloc);
230 pmd_phys = pgtable_alloc();
231 __pud_populate(pud, pmd_phys, PUD_TYPE_TABLE);
233 BUG_ON(pud_bad(*pud));
236 pgprot_t __prot = prot;
238 next = pmd_cont_addr_end(addr, end);
240 /* use a contiguous mapping if the range is suitably aligned */
241 if ((((addr | next | phys) & ~CONT_PMD_MASK) == 0) &&
242 (flags & NO_CONT_MAPPINGS) == 0)
243 __prot = __pgprot(pgprot_val(prot) | PTE_CONT);
245 init_pmd(pud, addr, next, phys, __prot, pgtable_alloc, flags);
248 } while (addr = next, addr != end);
251 static inline bool use_1G_block(unsigned long addr, unsigned long next,
254 if (PAGE_SHIFT != 12)
257 if (((addr | next | phys) & ~PUD_MASK) != 0)
263 static void alloc_init_pud(pgd_t *pgd, unsigned long addr, unsigned long end,
264 phys_addr_t phys, pgprot_t prot,
265 phys_addr_t (*pgtable_alloc)(void),
271 if (pgd_none(*pgd)) {
272 phys_addr_t pud_phys;
273 BUG_ON(!pgtable_alloc);
274 pud_phys = pgtable_alloc();
275 __pgd_populate(pgd, pud_phys, PUD_TYPE_TABLE);
277 BUG_ON(pgd_bad(*pgd));
279 pud = pud_set_fixmap_offset(pgd, addr);
281 pud_t old_pud = *pud;
283 next = pud_addr_end(addr, end);
286 * For 4K granule only, attempt to put down a 1GB block
288 if (use_1G_block(addr, next, phys) &&
289 (flags & NO_BLOCK_MAPPINGS) == 0) {
290 pud_set_huge(pud, phys, prot);
293 * After the PUD entry has been populated once, we
294 * only allow updates to the permission attributes.
296 BUG_ON(!pgattr_change_is_safe(pud_val(old_pud),
299 alloc_init_cont_pmd(pud, addr, next, phys, prot,
300 pgtable_alloc, flags);
302 BUG_ON(pud_val(old_pud) != 0 &&
303 pud_val(old_pud) != pud_val(*pud));
306 } while (pud++, addr = next, addr != end);
311 static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
312 unsigned long virt, phys_addr_t size,
314 phys_addr_t (*pgtable_alloc)(void),
317 unsigned long addr, length, end, next;
318 pgd_t *pgd = pgd_offset_raw(pgdir, virt);
321 * If the virtual and physical address don't have the same offset
322 * within a page, we cannot map the region as the caller expects.
324 if (WARN_ON((phys ^ virt) & ~PAGE_MASK))
328 addr = virt & PAGE_MASK;
329 length = PAGE_ALIGN(size + (virt & ~PAGE_MASK));
333 next = pgd_addr_end(addr, end);
334 alloc_init_pud(pgd, addr, next, phys, prot, pgtable_alloc,
337 } while (pgd++, addr = next, addr != end);
340 static phys_addr_t pgd_pgtable_alloc(void)
342 void *ptr = (void *)__get_free_page(PGALLOC_GFP);
343 if (!ptr || !pgtable_page_ctor(virt_to_page(ptr)))
346 /* Ensure the zeroed page is visible to the page table walker */
352 * This function can only be used to modify existing table entries,
353 * without allocating new levels of table. Note that this permits the
354 * creation of new section or page entries.
356 static void __init create_mapping_noalloc(phys_addr_t phys, unsigned long virt,
357 phys_addr_t size, pgprot_t prot)
359 if (virt < VMALLOC_START) {
360 pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n",
364 __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL,
368 void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
369 unsigned long virt, phys_addr_t size,
370 pgprot_t prot, bool page_mappings_only)
374 BUG_ON(mm == &init_mm);
376 if (page_mappings_only)
377 flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
379 __create_pgd_mapping(mm->pgd, phys, virt, size, prot,
380 pgd_pgtable_alloc, flags);
383 static void update_mapping_prot(phys_addr_t phys, unsigned long virt,
384 phys_addr_t size, pgprot_t prot)
386 if (virt < VMALLOC_START) {
387 pr_warn("BUG: not updating mapping for %pa at 0x%016lx - outside kernel range\n",
392 __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL,
395 /* flush the TLBs after updating live kernel mappings */
396 flush_tlb_kernel_range(virt, virt + size);
399 static void __init __map_memblock(pgd_t *pgd, phys_addr_t start,
400 phys_addr_t end, pgprot_t prot, int flags)
402 __create_pgd_mapping(pgd, start, __phys_to_virt(start), end - start,
403 prot, early_pgtable_alloc, flags);
406 void __init mark_linear_text_alias_ro(void)
409 * Remove the write permissions from the linear alias of .text/.rodata
411 update_mapping_prot(__pa_symbol(_text), (unsigned long)lm_alias(_text),
412 (unsigned long)__init_begin - (unsigned long)_text,
416 static void __init map_mem(pgd_t *pgd)
418 phys_addr_t kernel_start = __pa_symbol(_text);
419 phys_addr_t kernel_end = __pa_symbol(__init_begin);
420 struct memblock_region *reg;
423 if (debug_pagealloc_enabled())
424 flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
427 * Take care not to create a writable alias for the
428 * read-only text and rodata sections of the kernel image.
429 * So temporarily mark them as NOMAP to skip mappings in
430 * the following for-loop
432 memblock_mark_nomap(kernel_start, kernel_end - kernel_start);
433 #ifdef CONFIG_KEXEC_CORE
435 memblock_mark_nomap(crashk_res.start,
436 resource_size(&crashk_res));
439 /* map all the memory banks */
440 for_each_memblock(memory, reg) {
441 phys_addr_t start = reg->base;
442 phys_addr_t end = start + reg->size;
446 if (memblock_is_nomap(reg))
449 __map_memblock(pgd, start, end, PAGE_KERNEL, flags);
453 * Map the linear alias of the [_text, __init_begin) interval
454 * as non-executable now, and remove the write permission in
455 * mark_linear_text_alias_ro() below (which will be called after
456 * alternative patching has completed). This makes the contents
457 * of the region accessible to subsystems such as hibernate,
458 * but protects it from inadvertent modification or execution.
459 * Note that contiguous mappings cannot be remapped in this way,
460 * so we should avoid them here.
462 __map_memblock(pgd, kernel_start, kernel_end,
463 PAGE_KERNEL, NO_CONT_MAPPINGS);
464 memblock_clear_nomap(kernel_start, kernel_end - kernel_start);
466 #ifdef CONFIG_KEXEC_CORE
468 * Use page-level mappings here so that we can shrink the region
469 * in page granularity and put back unused memory to buddy system
470 * through /sys/kernel/kexec_crash_size interface.
472 if (crashk_res.end) {
473 __map_memblock(pgd, crashk_res.start, crashk_res.end + 1,
475 NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS);
476 memblock_clear_nomap(crashk_res.start,
477 resource_size(&crashk_res));
482 void mark_rodata_ro(void)
484 unsigned long section_size;
487 * mark .rodata as read only. Use __init_begin rather than __end_rodata
488 * to cover NOTES and EXCEPTION_TABLE.
490 section_size = (unsigned long)__init_begin - (unsigned long)__start_rodata;
491 update_mapping_prot(__pa_symbol(__start_rodata), (unsigned long)__start_rodata,
492 section_size, PAGE_KERNEL_RO);
497 static void __init map_kernel_segment(pgd_t *pgd, void *va_start, void *va_end,
498 pgprot_t prot, struct vm_struct *vma,
499 int flags, unsigned long vm_flags)
501 phys_addr_t pa_start = __pa_symbol(va_start);
502 unsigned long size = va_end - va_start;
504 BUG_ON(!PAGE_ALIGNED(pa_start));
505 BUG_ON(!PAGE_ALIGNED(size));
507 __create_pgd_mapping(pgd, pa_start, (unsigned long)va_start, size, prot,
508 early_pgtable_alloc, flags);
510 if (!(vm_flags & VM_NO_GUARD))
513 vma->addr = va_start;
514 vma->phys_addr = pa_start;
516 vma->flags = VM_MAP | vm_flags;
517 vma->caller = __builtin_return_address(0);
519 vm_area_add_early(vma);
522 static int __init parse_rodata(char *arg)
524 return strtobool(arg, &rodata_enabled);
526 early_param("rodata", parse_rodata);
529 * Create fine-grained mappings for the kernel.
531 static void __init map_kernel(pgd_t *pgd)
533 static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_inittext,
534 vmlinux_initdata, vmlinux_data;
537 * External debuggers may need to write directly to the text
538 * mapping to install SW breakpoints. Allow this (only) when
539 * explicitly requested with rodata=off.
541 pgprot_t text_prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;
544 * Only rodata will be remapped with different permissions later on,
545 * all other segments are allowed to use contiguous mappings.
547 map_kernel_segment(pgd, _text, _etext, text_prot, &vmlinux_text, 0,
549 map_kernel_segment(pgd, __start_rodata, __inittext_begin, PAGE_KERNEL,
550 &vmlinux_rodata, NO_CONT_MAPPINGS, VM_NO_GUARD);
551 map_kernel_segment(pgd, __inittext_begin, __inittext_end, text_prot,
552 &vmlinux_inittext, 0, VM_NO_GUARD);
553 map_kernel_segment(pgd, __initdata_begin, __initdata_end, PAGE_KERNEL,
554 &vmlinux_initdata, 0, VM_NO_GUARD);
555 map_kernel_segment(pgd, _data, _end, PAGE_KERNEL, &vmlinux_data, 0, 0);
557 if (!pgd_val(*pgd_offset_raw(pgd, FIXADDR_START))) {
559 * The fixmap falls in a separate pgd to the kernel, and doesn't
560 * live in the carveout for the swapper_pg_dir. We can simply
561 * re-use the existing dir for the fixmap.
563 set_pgd(pgd_offset_raw(pgd, FIXADDR_START),
564 *pgd_offset_k(FIXADDR_START));
565 } else if (CONFIG_PGTABLE_LEVELS > 3) {
567 * The fixmap shares its top level pgd entry with the kernel
568 * mapping. This can really only occur when we are running
569 * with 16k/4 levels, so we can simply reuse the pud level
572 BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES));
573 set_pud(pud_set_fixmap_offset(pgd, FIXADDR_START),
574 __pud(__pa_symbol(bm_pmd) | PUD_TYPE_TABLE));
580 kasan_copy_shadow(pgd);
584 * paging_init() sets up the page tables, initialises the zone memory
585 * maps and sets up the zero page.
587 void __init paging_init(void)
589 phys_addr_t pgd_phys = early_pgtable_alloc();
590 pgd_t *pgd = pgd_set_fixmap(pgd_phys);
596 * We want to reuse the original swapper_pg_dir so we don't have to
597 * communicate the new address to non-coherent secondaries in
598 * secondary_entry, and so cpu_switch_mm can generate the address with
599 * adrp+add rather than a load from some global variable.
601 * To do this we need to go via a temporary pgd.
603 cpu_replace_ttbr1(__va(pgd_phys));
604 memcpy(swapper_pg_dir, pgd, PGD_SIZE);
605 cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
608 memblock_free(pgd_phys, PAGE_SIZE);
611 * We only reuse the PGD from the swapper_pg_dir, not the pud + pmd
614 memblock_free(__pa_symbol(swapper_pg_dir) + PAGE_SIZE,
615 SWAPPER_DIR_SIZE - PAGE_SIZE);
619 * Check whether a kernel address is valid (derived from arch/x86/).
621 int kern_addr_valid(unsigned long addr)
628 if ((((long)addr) >> VA_BITS) != -1UL)
631 pgd = pgd_offset_k(addr);
635 pud = pud_offset(pgd, addr);
640 return pfn_valid(pud_pfn(*pud));
642 pmd = pmd_offset(pud, addr);
647 return pfn_valid(pmd_pfn(*pmd));
649 pte = pte_offset_kernel(pmd, addr);
653 return pfn_valid(pte_pfn(*pte));
655 #ifdef CONFIG_SPARSEMEM_VMEMMAP
656 #if !ARM64_SWAPPER_USES_SECTION_MAPS
657 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
659 return vmemmap_populate_basepages(start, end, node);
661 #else /* !ARM64_SWAPPER_USES_SECTION_MAPS */
662 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
664 unsigned long addr = start;
671 next = pmd_addr_end(addr, end);
673 pgd = vmemmap_pgd_populate(addr, node);
677 pud = vmemmap_pud_populate(pgd, addr, node);
681 pmd = pmd_offset(pud, addr);
682 if (pmd_none(*pmd)) {
685 p = vmemmap_alloc_block_buf(PMD_SIZE, node);
689 set_pmd(pmd, __pmd(__pa(p) | PROT_SECT_NORMAL));
691 vmemmap_verify((pte_t *)pmd, node, addr, next);
692 } while (addr = next, addr != end);
696 #endif /* CONFIG_ARM64_64K_PAGES */
697 void vmemmap_free(unsigned long start, unsigned long end)
700 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
702 static inline pud_t * fixmap_pud(unsigned long addr)
704 pgd_t *pgd = pgd_offset_k(addr);
706 BUG_ON(pgd_none(*pgd) || pgd_bad(*pgd));
708 return pud_offset_kimg(pgd, addr);
711 static inline pmd_t * fixmap_pmd(unsigned long addr)
713 pud_t *pud = fixmap_pud(addr);
715 BUG_ON(pud_none(*pud) || pud_bad(*pud));
717 return pmd_offset_kimg(pud, addr);
720 static inline pte_t * fixmap_pte(unsigned long addr)
722 return &bm_pte[pte_index(addr)];
726 * The p*d_populate functions call virt_to_phys implicitly so they can't be used
727 * directly on kernel symbols (bm_p*d). This function is called too early to use
728 * lm_alias so __p*d_populate functions must be used to populate with the
729 * physical address from __pa_symbol.
731 void __init early_fixmap_init(void)
736 unsigned long addr = FIXADDR_START;
738 pgd = pgd_offset_k(addr);
739 if (CONFIG_PGTABLE_LEVELS > 3 &&
740 !(pgd_none(*pgd) || pgd_page_paddr(*pgd) == __pa_symbol(bm_pud))) {
742 * We only end up here if the kernel mapping and the fixmap
743 * share the top level pgd entry, which should only happen on
744 * 16k/4 levels configurations.
746 BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES));
747 pud = pud_offset_kimg(pgd, addr);
750 __pgd_populate(pgd, __pa_symbol(bm_pud), PUD_TYPE_TABLE);
751 pud = fixmap_pud(addr);
754 __pud_populate(pud, __pa_symbol(bm_pmd), PMD_TYPE_TABLE);
755 pmd = fixmap_pmd(addr);
756 __pmd_populate(pmd, __pa_symbol(bm_pte), PMD_TYPE_TABLE);
759 * The boot-ioremap range spans multiple pmds, for which
760 * we are not prepared:
762 BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
763 != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
765 if ((pmd != fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)))
766 || pmd != fixmap_pmd(fix_to_virt(FIX_BTMAP_END))) {
768 pr_warn("pmd %p != %p, %p\n",
769 pmd, fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)),
770 fixmap_pmd(fix_to_virt(FIX_BTMAP_END)));
771 pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
772 fix_to_virt(FIX_BTMAP_BEGIN));
773 pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n",
774 fix_to_virt(FIX_BTMAP_END));
776 pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
777 pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN);
781 void __set_fixmap(enum fixed_addresses idx,
782 phys_addr_t phys, pgprot_t flags)
784 unsigned long addr = __fix_to_virt(idx);
787 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
789 pte = fixmap_pte(addr);
791 if (pgprot_val(flags)) {
792 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
794 pte_clear(&init_mm, addr, pte);
795 flush_tlb_kernel_range(addr, addr+PAGE_SIZE);
799 void *__init __fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot)
801 const u64 dt_virt_base = __fix_to_virt(FIX_FDT);
806 * Check whether the physical FDT address is set and meets the minimum
807 * alignment requirement. Since we are relying on MIN_FDT_ALIGN to be
808 * at least 8 bytes so that we can always access the magic and size
809 * fields of the FDT header after mapping the first chunk, double check
810 * here if that is indeed the case.
812 BUILD_BUG_ON(MIN_FDT_ALIGN < 8);
813 if (!dt_phys || dt_phys % MIN_FDT_ALIGN)
817 * Make sure that the FDT region can be mapped without the need to
818 * allocate additional translation table pages, so that it is safe
819 * to call create_mapping_noalloc() this early.
821 * On 64k pages, the FDT will be mapped using PTEs, so we need to
822 * be in the same PMD as the rest of the fixmap.
823 * On 4k pages, we'll use section mappings for the FDT so we only
824 * have to be in the same PUD.
826 BUILD_BUG_ON(dt_virt_base % SZ_2M);
828 BUILD_BUG_ON(__fix_to_virt(FIX_FDT_END) >> SWAPPER_TABLE_SHIFT !=
829 __fix_to_virt(FIX_BTMAP_BEGIN) >> SWAPPER_TABLE_SHIFT);
831 offset = dt_phys % SWAPPER_BLOCK_SIZE;
832 dt_virt = (void *)dt_virt_base + offset;
834 /* map the first chunk so we can read the size from the header */
835 create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE),
836 dt_virt_base, SWAPPER_BLOCK_SIZE, prot);
838 if (fdt_magic(dt_virt) != FDT_MAGIC)
841 *size = fdt_totalsize(dt_virt);
842 if (*size > MAX_FDT_SIZE)
845 if (offset + *size > SWAPPER_BLOCK_SIZE)
846 create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE), dt_virt_base,
847 round_up(offset + *size, SWAPPER_BLOCK_SIZE), prot);
852 void *__init fixmap_remap_fdt(phys_addr_t dt_phys)
857 dt_virt = __fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL_RO);
861 memblock_reserve(dt_phys, size);
865 int __init arch_ioremap_pud_supported(void)
867 /* only 4k granule supports level 1 block mappings */
868 return IS_ENABLED(CONFIG_ARM64_4K_PAGES);
871 int __init arch_ioremap_pmd_supported(void)
876 int pud_set_huge(pud_t *pud, phys_addr_t phys, pgprot_t prot)
878 BUG_ON(phys & ~PUD_MASK);
879 set_pud(pud, __pud(phys | PUD_TYPE_SECT | pgprot_val(mk_sect_prot(prot))));
883 int pmd_set_huge(pmd_t *pmd, phys_addr_t phys, pgprot_t prot)
885 BUG_ON(phys & ~PMD_MASK);
886 set_pmd(pmd, __pmd(phys | PMD_TYPE_SECT | pgprot_val(mk_sect_prot(prot))));
890 int pud_clear_huge(pud_t *pud)
898 int pmd_clear_huge(pmd_t *pmd)