1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/arch/arm/mm/init.c
5 * Copyright (C) 1995-2005 Russell King
7 #include <linux/kernel.h>
8 #include <linux/errno.h>
9 #include <linux/swap.h>
10 #include <linux/init.h>
11 #include <linux/mman.h>
12 #include <linux/sched/signal.h>
13 #include <linux/sched/task.h>
14 #include <linux/export.h>
15 #include <linux/nodemask.h>
16 #include <linux/initrd.h>
17 #include <linux/of_fdt.h>
18 #include <linux/highmem.h>
19 #include <linux/gfp.h>
20 #include <linux/memblock.h>
21 #include <linux/dma-contiguous.h>
22 #include <linux/sizes.h>
23 #include <linux/stop_machine.h>
24 #include <linux/swiotlb.h>
27 #include <asm/mach-types.h>
28 #include <asm/memblock.h>
29 #include <asm/memory.h>
31 #include <asm/sections.h>
32 #include <asm/setup.h>
33 #include <asm/system_info.h>
35 #include <asm/fixmap.h>
36 #include <asm/ptdump.h>
38 #include <asm/mach/arch.h>
39 #include <asm/mach/map.h>
43 #ifdef CONFIG_CPU_CP15_MMU
44 unsigned long __init
__clear_cr(unsigned long mask
)
46 cr_alignment
= cr_alignment
& ~mask
;
51 #ifdef CONFIG_BLK_DEV_INITRD
52 static int __init
parse_tag_initrd(const struct tag
*tag
)
54 pr_warn("ATAG_INITRD is deprecated; "
55 "please update your bootloader.\n");
56 phys_initrd_start
= __virt_to_phys(tag
->u
.initrd
.start
);
57 phys_initrd_size
= tag
->u
.initrd
.size
;
61 __tagtable(ATAG_INITRD
, parse_tag_initrd
);
63 static int __init
parse_tag_initrd2(const struct tag
*tag
)
65 phys_initrd_start
= tag
->u
.initrd
.start
;
66 phys_initrd_size
= tag
->u
.initrd
.size
;
70 __tagtable(ATAG_INITRD2
, parse_tag_initrd2
);
73 static void __init
find_limits(unsigned long *min
, unsigned long *max_low
,
74 unsigned long *max_high
)
76 *max_low
= PFN_DOWN(memblock_get_current_limit());
77 *min
= PFN_UP(memblock_start_of_DRAM());
78 *max_high
= PFN_DOWN(memblock_end_of_DRAM());
81 #ifdef CONFIG_ZONE_DMA
83 phys_addr_t arm_dma_zone_size __read_mostly
;
84 EXPORT_SYMBOL(arm_dma_zone_size
);
87 * The DMA mask corresponding to the maximum bus address allocatable
88 * using GFP_DMA. The default here places no restriction on DMA
89 * allocations. This must be the smallest DMA mask in the system,
90 * so a successful GFP_DMA allocation will always satisfy this.
92 phys_addr_t arm_dma_limit
;
93 unsigned long arm_dma_pfn_limit
;
95 static void __init
arm_adjust_dma_zone(unsigned long *size
, unsigned long *hole
,
96 unsigned long dma_size
)
98 if (size
[0] <= dma_size
)
101 size
[ZONE_NORMAL
] = size
[0] - dma_size
;
102 size
[ZONE_DMA
] = dma_size
;
103 hole
[ZONE_NORMAL
] = hole
[0];
108 void __init
setup_dma_zone(const struct machine_desc
*mdesc
)
110 #ifdef CONFIG_ZONE_DMA
111 if (mdesc
->dma_zone_size
) {
112 arm_dma_zone_size
= mdesc
->dma_zone_size
;
113 arm_dma_limit
= PHYS_OFFSET
+ arm_dma_zone_size
- 1;
115 arm_dma_limit
= 0xffffffff;
116 arm_dma_pfn_limit
= arm_dma_limit
>> PAGE_SHIFT
;
120 static void __init
zone_sizes_init(unsigned long min
, unsigned long max_low
,
121 unsigned long max_high
)
123 unsigned long zone_size
[MAX_NR_ZONES
], zhole_size
[MAX_NR_ZONES
];
124 struct memblock_region
*reg
;
127 * initialise the zones.
129 memset(zone_size
, 0, sizeof(zone_size
));
132 * The memory size has already been determined. If we need
133 * to do anything fancy with the allocation of this memory
134 * to the zones, now is the time to do it.
136 zone_size
[0] = max_low
- min
;
137 #ifdef CONFIG_HIGHMEM
138 zone_size
[ZONE_HIGHMEM
] = max_high
- max_low
;
142 * Calculate the size of the holes.
143 * holes = node_size - sum(bank_sizes)
145 memcpy(zhole_size
, zone_size
, sizeof(zhole_size
));
146 for_each_memblock(memory
, reg
) {
147 unsigned long start
= memblock_region_memory_base_pfn(reg
);
148 unsigned long end
= memblock_region_memory_end_pfn(reg
);
150 if (start
< max_low
) {
151 unsigned long low_end
= min(end
, max_low
);
152 zhole_size
[0] -= low_end
- start
;
154 #ifdef CONFIG_HIGHMEM
156 unsigned long high_start
= max(start
, max_low
);
157 zhole_size
[ZONE_HIGHMEM
] -= end
- high_start
;
162 #ifdef CONFIG_ZONE_DMA
164 * Adjust the sizes according to any special requirements for
167 if (arm_dma_zone_size
)
168 arm_adjust_dma_zone(zone_size
, zhole_size
,
169 arm_dma_zone_size
>> PAGE_SHIFT
);
172 free_area_init_node(0, zone_size
, min
, zhole_size
);
175 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
176 int pfn_valid(unsigned long pfn
)
178 phys_addr_t addr
= __pfn_to_phys(pfn
);
180 if (__phys_to_pfn(addr
) != pfn
)
183 return memblock_is_map_memory(addr
);
185 EXPORT_SYMBOL(pfn_valid
);
188 static bool arm_memblock_steal_permitted
= true;
190 phys_addr_t __init
arm_memblock_steal(phys_addr_t size
, phys_addr_t align
)
194 BUG_ON(!arm_memblock_steal_permitted
);
196 phys
= memblock_phys_alloc(size
, align
);
198 panic("Failed to steal %pa bytes at %pS\n",
199 &size
, (void *)_RET_IP_
);
201 memblock_free(phys
, size
);
202 memblock_remove(phys
, size
);
207 static void __init
arm_initrd_init(void)
209 #ifdef CONFIG_BLK_DEV_INITRD
213 initrd_start
= initrd_end
= 0;
215 if (!phys_initrd_size
)
219 * Round the memory region to page boundaries as per free_initrd_mem()
220 * This allows us to detect whether the pages overlapping the initrd
221 * are in use, but more importantly, reserves the entire set of pages
222 * as we don't want these pages allocated for other purposes.
224 start
= round_down(phys_initrd_start
, PAGE_SIZE
);
225 size
= phys_initrd_size
+ (phys_initrd_start
- start
);
226 size
= round_up(size
, PAGE_SIZE
);
228 if (!memblock_is_region_memory(start
, size
)) {
229 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
234 if (memblock_is_region_reserved(start
, size
)) {
235 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
240 memblock_reserve(start
, size
);
242 /* Now convert initrd to virtual addresses */
243 initrd_start
= __phys_to_virt(phys_initrd_start
);
244 initrd_end
= initrd_start
+ phys_initrd_size
;
248 #ifdef CONFIG_CPU_ICACHE_MISMATCH_WORKAROUND
249 void check_cpu_icache_size(int cpuid
)
253 asm("mrc p15, 0, %0, c0, c0, 1" : "=r" (ctr
));
255 size
= 1 << ((ctr
& 0xf) + 2);
256 if (cpuid
!= 0 && icache_size
!= size
)
257 pr_info("CPU%u: detected I-Cache line size mismatch, workaround enabled\n",
259 if (icache_size
> size
)
264 void __init
arm_memblock_init(const struct machine_desc
*mdesc
)
266 /* Register the kernel text, kernel data and initrd with memblock. */
267 memblock_reserve(__pa(KERNEL_START
), KERNEL_END
- KERNEL_START
);
271 arm_mm_memblock_reserve();
273 /* reserve any platform specific memblock areas */
277 early_init_fdt_reserve_self();
278 early_init_fdt_scan_reserved_mem();
280 /* reserve memory for DMA contiguous allocations */
281 dma_contiguous_reserve(arm_dma_limit
);
283 arm_memblock_steal_permitted
= false;
287 void __init
bootmem_init(void)
289 memblock_allow_resize();
291 find_limits(&min_low_pfn
, &max_low_pfn
, &max_pfn
);
293 early_memtest((phys_addr_t
)min_low_pfn
<< PAGE_SHIFT
,
294 (phys_addr_t
)max_low_pfn
<< PAGE_SHIFT
);
297 * Sparsemem tries to allocate bootmem in memory_present(),
298 * so must be done after the fixed reservations
303 * sparse_init() needs the bootmem allocator up and running.
308 * Now free the memory - free_area_init_node needs
309 * the sparse mem_map arrays initialized by sparse_init()
310 * for memmap_init_zone(), otherwise all PFNs are invalid.
312 zone_sizes_init(min_low_pfn
, max_low_pfn
, max_pfn
);
316 * Poison init memory with an undefined instruction (ARM) or a branch to an
317 * undefined instruction (Thumb).
319 static inline void poison_init_mem(void *s
, size_t count
)
322 for (; count
!= 0; count
-= 4)
327 free_memmap(unsigned long start_pfn
, unsigned long end_pfn
)
329 struct page
*start_pg
, *end_pg
;
330 phys_addr_t pg
, pgend
;
333 * Convert start_pfn/end_pfn to a struct page pointer.
335 start_pg
= pfn_to_page(start_pfn
- 1) + 1;
336 end_pg
= pfn_to_page(end_pfn
- 1) + 1;
339 * Convert to physical addresses, and
340 * round start upwards and end downwards.
342 pg
= PAGE_ALIGN(__pa(start_pg
));
343 pgend
= __pa(end_pg
) & PAGE_MASK
;
346 * If there are free pages between these,
347 * free the section of the memmap array.
350 memblock_free_early(pg
, pgend
- pg
);
354 * The mem_map array can get very big. Free the unused area of the memory map.
356 static void __init
free_unused_memmap(void)
358 unsigned long start
, prev_end
= 0;
359 struct memblock_region
*reg
;
362 * This relies on each bank being in address order.
363 * The banks are sorted previously in bootmem_init().
365 for_each_memblock(memory
, reg
) {
366 start
= memblock_region_memory_base_pfn(reg
);
368 #ifdef CONFIG_SPARSEMEM
370 * Take care not to free memmap entries that don't exist
371 * due to SPARSEMEM sections which aren't present.
374 ALIGN(prev_end
, PAGES_PER_SECTION
));
377 * Align down here since the VM subsystem insists that the
378 * memmap entries are valid from the bank start aligned to
379 * MAX_ORDER_NR_PAGES.
381 start
= round_down(start
, MAX_ORDER_NR_PAGES
);
384 * If we had a previous bank, and there is a space
385 * between the current bank and the previous, free it.
387 if (prev_end
&& prev_end
< start
)
388 free_memmap(prev_end
, start
);
391 * Align up here since the VM subsystem insists that the
392 * memmap entries are valid from the bank end aligned to
393 * MAX_ORDER_NR_PAGES.
395 prev_end
= ALIGN(memblock_region_memory_end_pfn(reg
),
399 #ifdef CONFIG_SPARSEMEM
400 if (!IS_ALIGNED(prev_end
, PAGES_PER_SECTION
))
401 free_memmap(prev_end
,
402 ALIGN(prev_end
, PAGES_PER_SECTION
));
406 #ifdef CONFIG_HIGHMEM
407 static inline void free_area_high(unsigned long pfn
, unsigned long end
)
409 for (; pfn
< end
; pfn
++)
410 free_highmem_page(pfn_to_page(pfn
));
414 static void __init
free_highpages(void)
416 #ifdef CONFIG_HIGHMEM
417 unsigned long max_low
= max_low_pfn
;
418 struct memblock_region
*mem
, *res
;
420 /* set highmem page free */
421 for_each_memblock(memory
, mem
) {
422 unsigned long start
= memblock_region_memory_base_pfn(mem
);
423 unsigned long end
= memblock_region_memory_end_pfn(mem
);
425 /* Ignore complete lowmem entries */
429 if (memblock_is_nomap(mem
))
432 /* Truncate partial highmem entries */
436 /* Find and exclude any reserved regions */
437 for_each_memblock(reserved
, res
) {
438 unsigned long res_start
, res_end
;
440 res_start
= memblock_region_reserved_base_pfn(res
);
441 res_end
= memblock_region_reserved_end_pfn(res
);
445 if (res_start
< start
)
451 if (res_start
!= start
)
452 free_area_high(start
, res_start
);
458 /* And now free anything which remains */
460 free_area_high(start
, end
);
466 * mem_init() marks the free areas in the mem_map and tells us how much
467 * memory is free. This is done after various parts of the system have
468 * claimed their memory after the kernel image.
470 void __init
mem_init(void)
472 #ifdef CONFIG_ARM_LPAE
476 set_max_mapnr(pfn_to_page(max_pfn
) - mem_map
);
478 /* this will put all unused low memory onto the freelists */
479 free_unused_memmap();
483 /* now that our DMA memory is actually so designated, we can free it */
484 free_reserved_area(__va(PHYS_OFFSET
), swapper_pg_dir
, -1, NULL
);
489 mem_init_print_info(NULL
);
492 * Check boundaries twice: Some fundamental inconsistencies can
493 * be detected at build time already.
496 BUILD_BUG_ON(TASK_SIZE
> MODULES_VADDR
);
497 BUG_ON(TASK_SIZE
> MODULES_VADDR
);
500 #ifdef CONFIG_HIGHMEM
501 BUILD_BUG_ON(PKMAP_BASE
+ LAST_PKMAP
* PAGE_SIZE
> PAGE_OFFSET
);
502 BUG_ON(PKMAP_BASE
+ LAST_PKMAP
* PAGE_SIZE
> PAGE_OFFSET
);
506 #ifdef CONFIG_STRICT_KERNEL_RWX
507 struct section_perm
{
516 /* First section-aligned location at or after __start_rodata. */
517 extern char __start_rodata_section_aligned
[];
519 static struct section_perm nx_perms
[] = {
520 /* Make pages tables, etc before _stext RW (set NX). */
522 .name
= "pre-text NX",
523 .start
= PAGE_OFFSET
,
524 .end
= (unsigned long)_stext
,
525 .mask
= ~PMD_SECT_XN
,
528 /* Make init RW (set NX). */
531 .start
= (unsigned long)__init_begin
,
532 .end
= (unsigned long)_sdata
,
533 .mask
= ~PMD_SECT_XN
,
536 /* Make rodata NX (set RO in ro_perms below). */
539 .start
= (unsigned long)__start_rodata_section_aligned
,
540 .end
= (unsigned long)__init_begin
,
541 .mask
= ~PMD_SECT_XN
,
546 static struct section_perm ro_perms
[] = {
547 /* Make kernel code and rodata RX (set RO). */
549 .name
= "text/rodata RO",
550 .start
= (unsigned long)_stext
,
551 .end
= (unsigned long)__init_begin
,
552 #ifdef CONFIG_ARM_LPAE
553 .mask
= ~(L_PMD_SECT_RDONLY
| PMD_SECT_AP2
),
554 .prot
= L_PMD_SECT_RDONLY
| PMD_SECT_AP2
,
556 .mask
= ~(PMD_SECT_APX
| PMD_SECT_AP_WRITE
),
557 .prot
= PMD_SECT_APX
| PMD_SECT_AP_WRITE
,
558 .clear
= PMD_SECT_AP_WRITE
,
564 * Updates section permissions only for the current mm (sections are
565 * copied into each mm). During startup, this is the init_mm. Is only
566 * safe to be called with preemption disabled, as under stop_machine().
568 static inline void section_update(unsigned long addr
, pmdval_t mask
,
569 pmdval_t prot
, struct mm_struct
*mm
)
573 pmd
= pmd_offset(pud_offset(pgd_offset(mm
, addr
), addr
), addr
);
575 #ifdef CONFIG_ARM_LPAE
576 pmd
[0] = __pmd((pmd_val(pmd
[0]) & mask
) | prot
);
578 if (addr
& SECTION_SIZE
)
579 pmd
[1] = __pmd((pmd_val(pmd
[1]) & mask
) | prot
);
581 pmd
[0] = __pmd((pmd_val(pmd
[0]) & mask
) | prot
);
583 flush_pmd_entry(pmd
);
584 local_flush_tlb_kernel_range(addr
, addr
+ SECTION_SIZE
);
587 /* Make sure extended page tables are in use. */
588 static inline bool arch_has_strict_perms(void)
590 if (cpu_architecture() < CPU_ARCH_ARMv6
)
593 return !!(get_cr() & CR_XP
);
596 static void set_section_perms(struct section_perm
*perms
, int n
, bool set
,
597 struct mm_struct
*mm
)
602 if (!arch_has_strict_perms())
605 for (i
= 0; i
< n
; i
++) {
606 if (!IS_ALIGNED(perms
[i
].start
, SECTION_SIZE
) ||
607 !IS_ALIGNED(perms
[i
].end
, SECTION_SIZE
)) {
608 pr_err("BUG: %s section %lx-%lx not aligned to %lx\n",
609 perms
[i
].name
, perms
[i
].start
, perms
[i
].end
,
614 for (addr
= perms
[i
].start
;
616 addr
+= SECTION_SIZE
)
617 section_update(addr
, perms
[i
].mask
,
618 set
? perms
[i
].prot
: perms
[i
].clear
, mm
);
624 * update_sections_early intended to be called only through stop_machine
625 * framework and executed by only one CPU while all other CPUs will spin and
626 * wait, so no locking is required in this function.
628 static void update_sections_early(struct section_perm perms
[], int n
)
630 struct task_struct
*t
, *s
;
632 for_each_process(t
) {
633 if (t
->flags
& PF_KTHREAD
)
635 for_each_thread(t
, s
)
637 set_section_perms(perms
, n
, true, s
->mm
);
639 set_section_perms(perms
, n
, true, current
->active_mm
);
640 set_section_perms(perms
, n
, true, &init_mm
);
643 static int __fix_kernmem_perms(void *unused
)
645 update_sections_early(nx_perms
, ARRAY_SIZE(nx_perms
));
649 static void fix_kernmem_perms(void)
651 stop_machine(__fix_kernmem_perms
, NULL
, NULL
);
654 static int __mark_rodata_ro(void *unused
)
656 update_sections_early(ro_perms
, ARRAY_SIZE(ro_perms
));
660 static int kernel_set_to_readonly __read_mostly
;
662 void mark_rodata_ro(void)
664 kernel_set_to_readonly
= 1;
665 stop_machine(__mark_rodata_ro
, NULL
, NULL
);
669 void set_kernel_text_rw(void)
671 if (!kernel_set_to_readonly
)
674 set_section_perms(ro_perms
, ARRAY_SIZE(ro_perms
), false,
678 void set_kernel_text_ro(void)
680 if (!kernel_set_to_readonly
)
683 set_section_perms(ro_perms
, ARRAY_SIZE(ro_perms
), true,
688 static inline void fix_kernmem_perms(void) { }
689 #endif /* CONFIG_STRICT_KERNEL_RWX */
691 void free_initmem(void)
695 poison_init_mem(__init_begin
, __init_end
- __init_begin
);
696 if (!machine_is_integrator() && !machine_is_cintegrator())
697 free_initmem_default(-1);
700 #ifdef CONFIG_BLK_DEV_INITRD
701 void free_initrd_mem(unsigned long start
, unsigned long end
)
703 if (start
== initrd_start
)
704 start
= round_down(start
, PAGE_SIZE
);
705 if (end
== initrd_end
)
706 end
= round_up(end
, PAGE_SIZE
);
708 poison_init_mem((void *)start
, PAGE_ALIGN(end
) - start
);
709 free_reserved_area((void *)start
, (void *)end
, -1, "initrd");