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/export.h>
21 #include <linux/kernel.h>
22 #include <linux/errno.h>
23 #include <linux/init.h>
24 #include <linux/libfdt.h>
25 #include <linux/mman.h>
26 #include <linux/nodemask.h>
27 #include <linux/memblock.h>
30 #include <linux/slab.h>
31 #include <linux/stop_machine.h>
33 #include <asm/cputype.h>
34 #include <asm/fixmap.h>
35 #include <asm/sections.h>
36 #include <asm/setup.h>
37 #include <asm/sizes.h>
39 #include <asm/memblock.h>
40 #include <asm/mmu_context.h>
44 u64 idmap_t0sz
= TCR_T0SZ(VA_BITS
);
47 * Empty_zero_page is a special page that is used for zero-initialized data
50 struct page
*empty_zero_page
;
51 EXPORT_SYMBOL(empty_zero_page
);
53 pgprot_t
phys_mem_access_prot(struct file
*file
, unsigned long pfn
,
54 unsigned long size
, pgprot_t vma_prot
)
57 return pgprot_noncached(vma_prot
);
58 else if (file
->f_flags
& O_SYNC
)
59 return pgprot_writecombine(vma_prot
);
62 EXPORT_SYMBOL(phys_mem_access_prot
);
64 static void __init
*early_alloc(unsigned long sz
)
66 void *ptr
= __va(memblock_alloc(sz
, sz
));
73 * remap a PMD into pages
75 static void split_pmd(pmd_t
*pmd
, pte_t
*pte
)
77 unsigned long pfn
= pmd_pfn(*pmd
);
82 * Need to have the least restrictive permissions available
83 * permissions will be fixed up later
85 set_pte(pte
, pfn_pte(pfn
, PAGE_KERNEL_EXEC
));
87 } while (pte
++, i
++, i
< PTRS_PER_PTE
);
90 static void alloc_init_pte(pmd_t
*pmd
, unsigned long addr
,
91 unsigned long end
, unsigned long pfn
,
93 void *(*alloc
)(unsigned long size
))
97 if (pmd_none(*pmd
) || pmd_sect(*pmd
)) {
98 pte
= alloc(PTRS_PER_PTE
* sizeof(pte_t
));
101 __pmd_populate(pmd
, __pa(pte
), PMD_TYPE_TABLE
);
104 BUG_ON(pmd_bad(*pmd
));
106 pte
= pte_offset_kernel(pmd
, addr
);
108 set_pte(pte
, pfn_pte(pfn
, prot
));
110 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
113 void split_pud(pud_t
*old_pud
, pmd_t
*pmd
)
115 unsigned long addr
= pud_pfn(*old_pud
) << PAGE_SHIFT
;
116 pgprot_t prot
= __pgprot(pud_val(*old_pud
) ^ addr
);
120 set_pmd(pmd
, __pmd(addr
| pgprot_val(prot
)));
122 } while (pmd
++, i
++, i
< PTRS_PER_PMD
);
125 static void alloc_init_pmd(struct mm_struct
*mm
, pud_t
*pud
,
126 unsigned long addr
, unsigned long end
,
127 phys_addr_t phys
, pgprot_t prot
,
128 void *(*alloc
)(unsigned long size
))
134 * Check for initial section mappings in the pgd/pud and remove them.
136 if (pud_none(*pud
) || pud_sect(*pud
)) {
137 pmd
= alloc(PTRS_PER_PMD
* sizeof(pmd_t
));
138 if (pud_sect(*pud
)) {
140 * need to have the 1G of mappings continue to be
145 pud_populate(mm
, pud
, pmd
);
148 BUG_ON(pud_bad(*pud
));
150 pmd
= pmd_offset(pud
, addr
);
152 next
= pmd_addr_end(addr
, end
);
153 /* try section mapping first */
154 if (((addr
| next
| phys
) & ~SECTION_MASK
) == 0) {
156 set_pmd(pmd
, __pmd(phys
|
157 pgprot_val(mk_sect_prot(prot
))));
159 * Check for previous table entries created during
160 * boot (__create_page_tables) and flush them.
162 if (!pmd_none(old_pmd
)) {
164 if (pmd_table(old_pmd
)) {
165 phys_addr_t table
= __pa(pte_offset_map(&old_pmd
, 0));
166 if (!WARN_ON_ONCE(slab_is_available()))
167 memblock_free(table
, PAGE_SIZE
);
171 alloc_init_pte(pmd
, addr
, next
, __phys_to_pfn(phys
),
175 } while (pmd
++, addr
= next
, addr
!= end
);
178 static inline bool use_1G_block(unsigned long addr
, unsigned long next
,
181 if (PAGE_SHIFT
!= 12)
184 if (((addr
| next
| phys
) & ~PUD_MASK
) != 0)
190 static void alloc_init_pud(struct mm_struct
*mm
, pgd_t
*pgd
,
191 unsigned long addr
, unsigned long end
,
192 phys_addr_t phys
, pgprot_t prot
,
193 void *(*alloc
)(unsigned long size
))
198 if (pgd_none(*pgd
)) {
199 pud
= alloc(PTRS_PER_PUD
* sizeof(pud_t
));
200 pgd_populate(mm
, pgd
, pud
);
202 BUG_ON(pgd_bad(*pgd
));
204 pud
= pud_offset(pgd
, addr
);
206 next
= pud_addr_end(addr
, end
);
209 * For 4K granule only, attempt to put down a 1GB block
211 if (use_1G_block(addr
, next
, phys
)) {
212 pud_t old_pud
= *pud
;
213 set_pud(pud
, __pud(phys
|
214 pgprot_val(mk_sect_prot(prot
))));
217 * If we have an old value for a pud, it will
218 * be pointing to a pmd table that we no longer
219 * need (from swapper_pg_dir).
221 * Look up the old pmd table and free it.
223 if (!pud_none(old_pud
)) {
225 if (pud_table(old_pud
)) {
226 phys_addr_t table
= __pa(pmd_offset(&old_pud
, 0));
227 if (!WARN_ON_ONCE(slab_is_available()))
228 memblock_free(table
, PAGE_SIZE
);
232 alloc_init_pmd(mm
, pud
, addr
, next
, phys
, prot
, alloc
);
235 } while (pud
++, addr
= next
, addr
!= end
);
239 * Create the page directory entries and any necessary page tables for the
240 * mapping specified by 'md'.
242 static void __create_mapping(struct mm_struct
*mm
, pgd_t
*pgd
,
243 phys_addr_t phys
, unsigned long virt
,
244 phys_addr_t size
, pgprot_t prot
,
245 void *(*alloc
)(unsigned long size
))
247 unsigned long addr
, length
, end
, next
;
249 addr
= virt
& PAGE_MASK
;
250 length
= PAGE_ALIGN(size
+ (virt
& ~PAGE_MASK
));
254 next
= pgd_addr_end(addr
, end
);
255 alloc_init_pud(mm
, pgd
, addr
, next
, phys
, prot
, alloc
);
257 } while (pgd
++, addr
= next
, addr
!= end
);
260 static void *late_alloc(unsigned long size
)
264 BUG_ON(size
> PAGE_SIZE
);
265 ptr
= (void *)__get_free_page(PGALLOC_GFP
);
270 static void __init
create_mapping(phys_addr_t phys
, unsigned long virt
,
271 phys_addr_t size
, pgprot_t prot
)
273 if (virt
< VMALLOC_START
) {
274 pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n",
278 __create_mapping(&init_mm
, pgd_offset_k(virt
& PAGE_MASK
), phys
, virt
,
279 size
, prot
, early_alloc
);
282 void __init
create_pgd_mapping(struct mm_struct
*mm
, phys_addr_t phys
,
283 unsigned long virt
, phys_addr_t size
,
286 __create_mapping(mm
, pgd_offset(mm
, virt
), phys
, virt
, size
, prot
,
290 static void create_mapping_late(phys_addr_t phys
, unsigned long virt
,
291 phys_addr_t size
, pgprot_t prot
)
293 if (virt
< VMALLOC_START
) {
294 pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n",
299 return __create_mapping(&init_mm
, pgd_offset_k(virt
& PAGE_MASK
),
300 phys
, virt
, size
, prot
, late_alloc
);
303 #ifdef CONFIG_DEBUG_RODATA
304 static void __init
__map_memblock(phys_addr_t start
, phys_addr_t end
)
307 * Set up the executable regions using the existing section mappings
308 * for now. This will get more fine grained later once all memory
311 unsigned long kernel_x_start
= round_down(__pa(_stext
), SECTION_SIZE
);
312 unsigned long kernel_x_end
= round_up(__pa(__init_end
), SECTION_SIZE
);
314 if (end
< kernel_x_start
) {
315 create_mapping(start
, __phys_to_virt(start
),
316 end
- start
, PAGE_KERNEL
);
317 } else if (start
>= kernel_x_end
) {
318 create_mapping(start
, __phys_to_virt(start
),
319 end
- start
, PAGE_KERNEL
);
321 if (start
< kernel_x_start
)
322 create_mapping(start
, __phys_to_virt(start
),
323 kernel_x_start
- start
,
325 create_mapping(kernel_x_start
,
326 __phys_to_virt(kernel_x_start
),
327 kernel_x_end
- kernel_x_start
,
329 if (kernel_x_end
< end
)
330 create_mapping(kernel_x_end
,
331 __phys_to_virt(kernel_x_end
),
338 static void __init
__map_memblock(phys_addr_t start
, phys_addr_t end
)
340 create_mapping(start
, __phys_to_virt(start
), end
- start
,
345 static void __init
map_mem(void)
347 struct memblock_region
*reg
;
351 * Temporarily limit the memblock range. We need to do this as
352 * create_mapping requires puds, pmds and ptes to be allocated from
353 * memory addressable from the initial direct kernel mapping.
355 * The initial direct kernel mapping, located at swapper_pg_dir, gives
356 * us PUD_SIZE (4K pages) or PMD_SIZE (64K pages) memory starting from
357 * PHYS_OFFSET (which must be aligned to 2MB as per
358 * Documentation/arm64/booting.txt).
360 if (IS_ENABLED(CONFIG_ARM64_64K_PAGES
))
361 limit
= PHYS_OFFSET
+ PMD_SIZE
;
363 limit
= PHYS_OFFSET
+ PUD_SIZE
;
364 memblock_set_current_limit(limit
);
366 /* map all the memory banks */
367 for_each_memblock(memory
, reg
) {
368 phys_addr_t start
= reg
->base
;
369 phys_addr_t end
= start
+ reg
->size
;
374 #ifndef CONFIG_ARM64_64K_PAGES
376 * For the first memory bank align the start address and
377 * current memblock limit to prevent create_mapping() from
378 * allocating pte page tables from unmapped memory.
379 * When 64K pages are enabled, the pte page table for the
380 * first PGDIR_SIZE is already present in swapper_pg_dir.
383 start
= ALIGN(start
, PMD_SIZE
);
385 limit
= end
& PMD_MASK
;
386 memblock_set_current_limit(limit
);
389 __map_memblock(start
, end
);
392 /* Limit no longer required. */
393 memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE
);
396 void __init
fixup_executable(void)
398 #ifdef CONFIG_DEBUG_RODATA
399 /* now that we are actually fully mapped, make the start/end more fine grained */
400 if (!IS_ALIGNED((unsigned long)_stext
, SECTION_SIZE
)) {
401 unsigned long aligned_start
= round_down(__pa(_stext
),
404 create_mapping(aligned_start
, __phys_to_virt(aligned_start
),
405 __pa(_stext
) - aligned_start
,
409 if (!IS_ALIGNED((unsigned long)__init_end
, SECTION_SIZE
)) {
410 unsigned long aligned_end
= round_up(__pa(__init_end
),
412 create_mapping(__pa(__init_end
), (unsigned long)__init_end
,
413 aligned_end
- __pa(__init_end
),
419 #ifdef CONFIG_DEBUG_RODATA
420 void mark_rodata_ro(void)
422 create_mapping_late(__pa(_stext
), (unsigned long)_stext
,
423 (unsigned long)_etext
- (unsigned long)_stext
,
424 PAGE_KERNEL_EXEC
| PTE_RDONLY
);
429 void fixup_init(void)
431 create_mapping_late(__pa(__init_begin
), (unsigned long)__init_begin
,
432 (unsigned long)__init_end
- (unsigned long)__init_begin
,
437 * paging_init() sets up the page tables, initialises the zone memory
438 * maps and sets up the zero page.
440 void __init
paging_init(void)
447 /* allocate the zero page. */
448 zero_page
= early_alloc(PAGE_SIZE
);
452 empty_zero_page
= virt_to_page(zero_page
);
455 * TTBR0 is only used for the identity mapping at this stage. Make it
456 * point to zero page to avoid speculatively fetching new entries.
458 cpu_set_reserved_ttbr0();
460 cpu_set_default_tcr_t0sz();
464 * Check whether a kernel address is valid (derived from arch/x86/).
466 int kern_addr_valid(unsigned long addr
)
473 if ((((long)addr
) >> VA_BITS
) != -1UL)
476 pgd
= pgd_offset_k(addr
);
480 pud
= pud_offset(pgd
, addr
);
485 return pfn_valid(pud_pfn(*pud
));
487 pmd
= pmd_offset(pud
, addr
);
492 return pfn_valid(pmd_pfn(*pmd
));
494 pte
= pte_offset_kernel(pmd
, addr
);
498 return pfn_valid(pte_pfn(*pte
));
500 #ifdef CONFIG_SPARSEMEM_VMEMMAP
501 #ifdef CONFIG_ARM64_64K_PAGES
502 int __meminit
vmemmap_populate(unsigned long start
, unsigned long end
, int node
)
504 return vmemmap_populate_basepages(start
, end
, node
);
506 #else /* !CONFIG_ARM64_64K_PAGES */
507 int __meminit
vmemmap_populate(unsigned long start
, unsigned long end
, int node
)
509 unsigned long addr
= start
;
516 next
= pmd_addr_end(addr
, end
);
518 pgd
= vmemmap_pgd_populate(addr
, node
);
522 pud
= vmemmap_pud_populate(pgd
, addr
, node
);
526 pmd
= pmd_offset(pud
, addr
);
527 if (pmd_none(*pmd
)) {
530 p
= vmemmap_alloc_block_buf(PMD_SIZE
, node
);
534 set_pmd(pmd
, __pmd(__pa(p
) | PROT_SECT_NORMAL
));
536 vmemmap_verify((pte_t
*)pmd
, node
, addr
, next
);
537 } while (addr
= next
, addr
!= end
);
541 #endif /* CONFIG_ARM64_64K_PAGES */
542 void vmemmap_free(unsigned long start
, unsigned long end
)
545 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
547 static pte_t bm_pte
[PTRS_PER_PTE
] __page_aligned_bss
;
548 #if CONFIG_PGTABLE_LEVELS > 2
549 static pmd_t bm_pmd
[PTRS_PER_PMD
] __page_aligned_bss
;
551 #if CONFIG_PGTABLE_LEVELS > 3
552 static pud_t bm_pud
[PTRS_PER_PUD
] __page_aligned_bss
;
555 static inline pud_t
* fixmap_pud(unsigned long addr
)
557 pgd_t
*pgd
= pgd_offset_k(addr
);
559 BUG_ON(pgd_none(*pgd
) || pgd_bad(*pgd
));
561 return pud_offset(pgd
, addr
);
564 static inline pmd_t
* fixmap_pmd(unsigned long addr
)
566 pud_t
*pud
= fixmap_pud(addr
);
568 BUG_ON(pud_none(*pud
) || pud_bad(*pud
));
570 return pmd_offset(pud
, addr
);
573 static inline pte_t
* fixmap_pte(unsigned long addr
)
575 pmd_t
*pmd
= fixmap_pmd(addr
);
577 BUG_ON(pmd_none(*pmd
) || pmd_bad(*pmd
));
579 return pte_offset_kernel(pmd
, addr
);
582 void __init
early_fixmap_init(void)
587 unsigned long addr
= FIXADDR_START
;
589 pgd
= pgd_offset_k(addr
);
590 pgd_populate(&init_mm
, pgd
, bm_pud
);
591 pud
= pud_offset(pgd
, addr
);
592 pud_populate(&init_mm
, pud
, bm_pmd
);
593 pmd
= pmd_offset(pud
, addr
);
594 pmd_populate_kernel(&init_mm
, pmd
, bm_pte
);
597 * The boot-ioremap range spans multiple pmds, for which
598 * we are not preparted:
600 BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN
) >> PMD_SHIFT
)
601 != (__fix_to_virt(FIX_BTMAP_END
) >> PMD_SHIFT
));
603 if ((pmd
!= fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN
)))
604 || pmd
!= fixmap_pmd(fix_to_virt(FIX_BTMAP_END
))) {
606 pr_warn("pmd %p != %p, %p\n",
607 pmd
, fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN
)),
608 fixmap_pmd(fix_to_virt(FIX_BTMAP_END
)));
609 pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
610 fix_to_virt(FIX_BTMAP_BEGIN
));
611 pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n",
612 fix_to_virt(FIX_BTMAP_END
));
614 pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END
);
615 pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN
);
619 void __set_fixmap(enum fixed_addresses idx
,
620 phys_addr_t phys
, pgprot_t flags
)
622 unsigned long addr
= __fix_to_virt(idx
);
625 BUG_ON(idx
<= FIX_HOLE
|| idx
>= __end_of_fixed_addresses
);
627 pte
= fixmap_pte(addr
);
629 if (pgprot_val(flags
)) {
630 set_pte(pte
, pfn_pte(phys
>> PAGE_SHIFT
, flags
));
632 pte_clear(&init_mm
, addr
, pte
);
633 flush_tlb_kernel_range(addr
, addr
+PAGE_SIZE
);
637 void *__init
fixmap_remap_fdt(phys_addr_t dt_phys
)
639 const u64 dt_virt_base
= __fix_to_virt(FIX_FDT
);
640 pgprot_t prot
= PAGE_KERNEL
| PTE_RDONLY
;
641 int granularity
, size
, offset
;
645 * Check whether the physical FDT address is set and meets the minimum
646 * alignment requirement. Since we are relying on MIN_FDT_ALIGN to be
647 * at least 8 bytes so that we can always access the size field of the
648 * FDT header after mapping the first chunk, double check here if that
649 * is indeed the case.
651 BUILD_BUG_ON(MIN_FDT_ALIGN
< 8);
652 if (!dt_phys
|| dt_phys
% MIN_FDT_ALIGN
)
656 * Make sure that the FDT region can be mapped without the need to
657 * allocate additional translation table pages, so that it is safe
658 * to call create_mapping() this early.
660 * On 64k pages, the FDT will be mapped using PTEs, so we need to
661 * be in the same PMD as the rest of the fixmap.
662 * On 4k pages, we'll use section mappings for the FDT so we only
663 * have to be in the same PUD.
665 BUILD_BUG_ON(dt_virt_base
% SZ_2M
);
667 if (IS_ENABLED(CONFIG_ARM64_64K_PAGES
)) {
668 BUILD_BUG_ON(__fix_to_virt(FIX_FDT_END
) >> PMD_SHIFT
!=
669 __fix_to_virt(FIX_BTMAP_BEGIN
) >> PMD_SHIFT
);
671 granularity
= PAGE_SIZE
;
673 BUILD_BUG_ON(__fix_to_virt(FIX_FDT_END
) >> PUD_SHIFT
!=
674 __fix_to_virt(FIX_BTMAP_BEGIN
) >> PUD_SHIFT
);
676 granularity
= PMD_SIZE
;
679 offset
= dt_phys
% granularity
;
680 dt_virt
= (void *)dt_virt_base
+ offset
;
682 /* map the first chunk so we can read the size from the header */
683 create_mapping(round_down(dt_phys
, granularity
), dt_virt_base
,
686 if (fdt_check_header(dt_virt
) != 0)
689 size
= fdt_totalsize(dt_virt
);
690 if (size
> MAX_FDT_SIZE
)
693 if (offset
+ size
> granularity
)
694 create_mapping(round_down(dt_phys
, granularity
), dt_virt_base
,
695 round_up(offset
+ size
, granularity
), prot
);
697 memblock_reserve(dt_phys
, size
);