2 * linux/arch/arm/mm/init.c
4 * Copyright (C) 1995-2005 Russell King
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 #include <linux/kernel.h>
11 #include <linux/errno.h>
12 #include <linux/swap.h>
13 #include <linux/init.h>
14 #include <linux/mman.h>
15 #include <linux/sched/signal.h>
16 #include <linux/sched/task.h>
17 #include <linux/export.h>
18 #include <linux/nodemask.h>
19 #include <linux/initrd.h>
20 #include <linux/of_fdt.h>
21 #include <linux/highmem.h>
22 #include <linux/gfp.h>
23 #include <linux/memblock.h>
24 #include <linux/dma-contiguous.h>
25 #include <linux/sizes.h>
26 #include <linux/stop_machine.h>
29 #include <asm/mach-types.h>
30 #include <asm/memblock.h>
31 #include <asm/memory.h>
33 #include <asm/sections.h>
34 #include <asm/setup.h>
35 #include <asm/system_info.h>
37 #include <asm/fixmap.h>
38 #include <asm/ptdump.h>
40 #include <asm/mach/arch.h>
41 #include <asm/mach/map.h>
45 #ifdef CONFIG_CPU_CP15_MMU
46 unsigned long __init
__clear_cr(unsigned long mask
)
48 cr_alignment
= cr_alignment
& ~mask
;
53 #ifdef CONFIG_BLK_DEV_INITRD
54 static int __init
parse_tag_initrd(const struct tag
*tag
)
56 pr_warn("ATAG_INITRD is deprecated; "
57 "please update your bootloader.\n");
58 phys_initrd_start
= __virt_to_phys(tag
->u
.initrd
.start
);
59 phys_initrd_size
= tag
->u
.initrd
.size
;
63 __tagtable(ATAG_INITRD
, parse_tag_initrd
);
65 static int __init
parse_tag_initrd2(const struct tag
*tag
)
67 phys_initrd_start
= tag
->u
.initrd
.start
;
68 phys_initrd_size
= tag
->u
.initrd
.size
;
72 __tagtable(ATAG_INITRD2
, parse_tag_initrd2
);
75 static void __init
find_limits(unsigned long *min
, unsigned long *max_low
,
76 unsigned long *max_high
)
78 *max_low
= PFN_DOWN(memblock_get_current_limit());
79 *min
= PFN_UP(memblock_start_of_DRAM());
80 *max_high
= PFN_DOWN(memblock_end_of_DRAM());
83 #ifdef CONFIG_ZONE_DMA
85 phys_addr_t arm_dma_zone_size __read_mostly
;
86 EXPORT_SYMBOL(arm_dma_zone_size
);
89 * The DMA mask corresponding to the maximum bus address allocatable
90 * using GFP_DMA. The default here places no restriction on DMA
91 * allocations. This must be the smallest DMA mask in the system,
92 * so a successful GFP_DMA allocation will always satisfy this.
94 phys_addr_t arm_dma_limit
;
95 unsigned long arm_dma_pfn_limit
;
97 static void __init
arm_adjust_dma_zone(unsigned long *size
, unsigned long *hole
,
98 unsigned long dma_size
)
100 if (size
[0] <= dma_size
)
103 size
[ZONE_NORMAL
] = size
[0] - dma_size
;
104 size
[ZONE_DMA
] = dma_size
;
105 hole
[ZONE_NORMAL
] = hole
[0];
110 void __init
setup_dma_zone(const struct machine_desc
*mdesc
)
112 #ifdef CONFIG_ZONE_DMA
113 if (mdesc
->dma_zone_size
) {
114 arm_dma_zone_size
= mdesc
->dma_zone_size
;
115 arm_dma_limit
= PHYS_OFFSET
+ arm_dma_zone_size
- 1;
117 arm_dma_limit
= 0xffffffff;
118 arm_dma_pfn_limit
= arm_dma_limit
>> PAGE_SHIFT
;
122 static void __init
zone_sizes_init(unsigned long min
, unsigned long max_low
,
123 unsigned long max_high
)
125 unsigned long zone_size
[MAX_NR_ZONES
], zhole_size
[MAX_NR_ZONES
];
126 struct memblock_region
*reg
;
129 * initialise the zones.
131 memset(zone_size
, 0, sizeof(zone_size
));
134 * The memory size has already been determined. If we need
135 * to do anything fancy with the allocation of this memory
136 * to the zones, now is the time to do it.
138 zone_size
[0] = max_low
- min
;
139 #ifdef CONFIG_HIGHMEM
140 zone_size
[ZONE_HIGHMEM
] = max_high
- max_low
;
144 * Calculate the size of the holes.
145 * holes = node_size - sum(bank_sizes)
147 memcpy(zhole_size
, zone_size
, sizeof(zhole_size
));
148 for_each_memblock(memory
, reg
) {
149 unsigned long start
= memblock_region_memory_base_pfn(reg
);
150 unsigned long end
= memblock_region_memory_end_pfn(reg
);
152 if (start
< max_low
) {
153 unsigned long low_end
= min(end
, max_low
);
154 zhole_size
[0] -= low_end
- start
;
156 #ifdef CONFIG_HIGHMEM
158 unsigned long high_start
= max(start
, max_low
);
159 zhole_size
[ZONE_HIGHMEM
] -= end
- high_start
;
164 #ifdef CONFIG_ZONE_DMA
166 * Adjust the sizes according to any special requirements for
169 if (arm_dma_zone_size
)
170 arm_adjust_dma_zone(zone_size
, zhole_size
,
171 arm_dma_zone_size
>> PAGE_SHIFT
);
174 free_area_init_node(0, zone_size
, min
, zhole_size
);
177 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
178 int pfn_valid(unsigned long pfn
)
180 return memblock_is_map_memory(__pfn_to_phys(pfn
));
182 EXPORT_SYMBOL(pfn_valid
);
185 #ifndef CONFIG_SPARSEMEM
186 static void __init
arm_memory_present(void)
190 static void __init
arm_memory_present(void)
192 struct memblock_region
*reg
;
194 for_each_memblock(memory
, reg
)
195 memory_present(0, memblock_region_memory_base_pfn(reg
),
196 memblock_region_memory_end_pfn(reg
));
200 static bool arm_memblock_steal_permitted
= true;
202 phys_addr_t __init
arm_memblock_steal(phys_addr_t size
, phys_addr_t align
)
206 BUG_ON(!arm_memblock_steal_permitted
);
208 phys
= memblock_phys_alloc(size
, align
);
210 panic("Failed to steal %pa bytes at %pS\n",
211 &size
, (void *)_RET_IP_
);
213 memblock_free(phys
, size
);
214 memblock_remove(phys
, size
);
219 static void __init
arm_initrd_init(void)
221 #ifdef CONFIG_BLK_DEV_INITRD
225 initrd_start
= initrd_end
= 0;
227 if (!phys_initrd_size
)
231 * Round the memory region to page boundaries as per free_initrd_mem()
232 * This allows us to detect whether the pages overlapping the initrd
233 * are in use, but more importantly, reserves the entire set of pages
234 * as we don't want these pages allocated for other purposes.
236 start
= round_down(phys_initrd_start
, PAGE_SIZE
);
237 size
= phys_initrd_size
+ (phys_initrd_start
- start
);
238 size
= round_up(size
, PAGE_SIZE
);
240 if (!memblock_is_region_memory(start
, size
)) {
241 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
246 if (memblock_is_region_reserved(start
, size
)) {
247 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
252 memblock_reserve(start
, size
);
254 /* Now convert initrd to virtual addresses */
255 initrd_start
= __phys_to_virt(phys_initrd_start
);
256 initrd_end
= initrd_start
+ phys_initrd_size
;
260 void __init
arm_memblock_init(const struct machine_desc
*mdesc
)
262 /* Register the kernel text, kernel data and initrd with memblock. */
263 memblock_reserve(__pa(KERNEL_START
), KERNEL_END
- KERNEL_START
);
267 arm_mm_memblock_reserve();
269 /* reserve any platform specific memblock areas */
273 early_init_fdt_reserve_self();
274 early_init_fdt_scan_reserved_mem();
276 /* reserve memory for DMA contiguous allocations */
277 dma_contiguous_reserve(arm_dma_limit
);
279 arm_memblock_steal_permitted
= false;
283 void __init
bootmem_init(void)
285 memblock_allow_resize();
287 find_limits(&min_low_pfn
, &max_low_pfn
, &max_pfn
);
289 early_memtest((phys_addr_t
)min_low_pfn
<< PAGE_SHIFT
,
290 (phys_addr_t
)max_low_pfn
<< PAGE_SHIFT
);
293 * Sparsemem tries to allocate bootmem in memory_present(),
294 * so must be done after the fixed reservations
296 arm_memory_present();
299 * sparse_init() needs the bootmem allocator up and running.
304 * Now free the memory - free_area_init_node needs
305 * the sparse mem_map arrays initialized by sparse_init()
306 * for memmap_init_zone(), otherwise all PFNs are invalid.
308 zone_sizes_init(min_low_pfn
, max_low_pfn
, max_pfn
);
312 * Poison init memory with an undefined instruction (ARM) or a branch to an
313 * undefined instruction (Thumb).
315 static inline void poison_init_mem(void *s
, size_t count
)
318 for (; count
!= 0; count
-= 4)
323 free_memmap(unsigned long start_pfn
, unsigned long end_pfn
)
325 struct page
*start_pg
, *end_pg
;
326 phys_addr_t pg
, pgend
;
329 * Convert start_pfn/end_pfn to a struct page pointer.
331 start_pg
= pfn_to_page(start_pfn
- 1) + 1;
332 end_pg
= pfn_to_page(end_pfn
- 1) + 1;
335 * Convert to physical addresses, and
336 * round start upwards and end downwards.
338 pg
= PAGE_ALIGN(__pa(start_pg
));
339 pgend
= __pa(end_pg
) & PAGE_MASK
;
342 * If there are free pages between these,
343 * free the section of the memmap array.
346 memblock_free_early(pg
, pgend
- pg
);
350 * The mem_map array can get very big. Free the unused area of the memory map.
352 static void __init
free_unused_memmap(void)
354 unsigned long start
, prev_end
= 0;
355 struct memblock_region
*reg
;
358 * This relies on each bank being in address order.
359 * The banks are sorted previously in bootmem_init().
361 for_each_memblock(memory
, reg
) {
362 start
= memblock_region_memory_base_pfn(reg
);
364 #ifdef CONFIG_SPARSEMEM
366 * Take care not to free memmap entries that don't exist
367 * due to SPARSEMEM sections which aren't present.
370 ALIGN(prev_end
, PAGES_PER_SECTION
));
373 * Align down here since the VM subsystem insists that the
374 * memmap entries are valid from the bank start aligned to
375 * MAX_ORDER_NR_PAGES.
377 start
= round_down(start
, MAX_ORDER_NR_PAGES
);
380 * If we had a previous bank, and there is a space
381 * between the current bank and the previous, free it.
383 if (prev_end
&& prev_end
< start
)
384 free_memmap(prev_end
, start
);
387 * Align up here since the VM subsystem insists that the
388 * memmap entries are valid from the bank end aligned to
389 * MAX_ORDER_NR_PAGES.
391 prev_end
= ALIGN(memblock_region_memory_end_pfn(reg
),
395 #ifdef CONFIG_SPARSEMEM
396 if (!IS_ALIGNED(prev_end
, PAGES_PER_SECTION
))
397 free_memmap(prev_end
,
398 ALIGN(prev_end
, PAGES_PER_SECTION
));
402 #ifdef CONFIG_HIGHMEM
403 static inline void free_area_high(unsigned long pfn
, unsigned long end
)
405 for (; pfn
< end
; pfn
++)
406 free_highmem_page(pfn_to_page(pfn
));
410 static void __init
free_highpages(void)
412 #ifdef CONFIG_HIGHMEM
413 unsigned long max_low
= max_low_pfn
;
414 struct memblock_region
*mem
, *res
;
416 /* set highmem page free */
417 for_each_memblock(memory
, mem
) {
418 unsigned long start
= memblock_region_memory_base_pfn(mem
);
419 unsigned long end
= memblock_region_memory_end_pfn(mem
);
421 /* Ignore complete lowmem entries */
425 if (memblock_is_nomap(mem
))
428 /* Truncate partial highmem entries */
432 /* Find and exclude any reserved regions */
433 for_each_memblock(reserved
, res
) {
434 unsigned long res_start
, res_end
;
436 res_start
= memblock_region_reserved_base_pfn(res
);
437 res_end
= memblock_region_reserved_end_pfn(res
);
441 if (res_start
< start
)
447 if (res_start
!= start
)
448 free_area_high(start
, res_start
);
454 /* And now free anything which remains */
456 free_area_high(start
, end
);
462 * mem_init() marks the free areas in the mem_map and tells us how much
463 * memory is free. This is done after various parts of the system have
464 * claimed their memory after the kernel image.
466 void __init
mem_init(void)
468 #ifdef CONFIG_HAVE_TCM
469 /* These pointers are filled in on TCM detection */
474 set_max_mapnr(pfn_to_page(max_pfn
) - mem_map
);
476 /* this will put all unused low memory onto the freelists */
477 free_unused_memmap();
481 /* now that our DMA memory is actually so designated, we can free it */
482 free_reserved_area(__va(PHYS_OFFSET
), swapper_pg_dir
, -1, NULL
);
487 mem_init_print_info(NULL
);
490 * Check boundaries twice: Some fundamental inconsistencies can
491 * be detected at build time already.
494 BUILD_BUG_ON(TASK_SIZE
> MODULES_VADDR
);
495 BUG_ON(TASK_SIZE
> MODULES_VADDR
);
498 #ifdef CONFIG_HIGHMEM
499 BUILD_BUG_ON(PKMAP_BASE
+ LAST_PKMAP
* PAGE_SIZE
> PAGE_OFFSET
);
500 BUG_ON(PKMAP_BASE
+ LAST_PKMAP
* PAGE_SIZE
> PAGE_OFFSET
);
504 #ifdef CONFIG_STRICT_KERNEL_RWX
505 struct section_perm
{
514 /* First section-aligned location at or after __start_rodata. */
515 extern char __start_rodata_section_aligned
[];
517 static struct section_perm nx_perms
[] = {
518 /* Make pages tables, etc before _stext RW (set NX). */
520 .name
= "pre-text NX",
521 .start
= PAGE_OFFSET
,
522 .end
= (unsigned long)_stext
,
523 .mask
= ~PMD_SECT_XN
,
526 /* Make init RW (set NX). */
529 .start
= (unsigned long)__init_begin
,
530 .end
= (unsigned long)_sdata
,
531 .mask
= ~PMD_SECT_XN
,
534 /* Make rodata NX (set RO in ro_perms below). */
537 .start
= (unsigned long)__start_rodata_section_aligned
,
538 .end
= (unsigned long)__init_begin
,
539 .mask
= ~PMD_SECT_XN
,
544 static struct section_perm ro_perms
[] = {
545 /* Make kernel code and rodata RX (set RO). */
547 .name
= "text/rodata RO",
548 .start
= (unsigned long)_stext
,
549 .end
= (unsigned long)__init_begin
,
550 #ifdef CONFIG_ARM_LPAE
551 .mask
= ~(L_PMD_SECT_RDONLY
| PMD_SECT_AP2
),
552 .prot
= L_PMD_SECT_RDONLY
| PMD_SECT_AP2
,
554 .mask
= ~(PMD_SECT_APX
| PMD_SECT_AP_WRITE
),
555 .prot
= PMD_SECT_APX
| PMD_SECT_AP_WRITE
,
556 .clear
= PMD_SECT_AP_WRITE
,
562 * Updates section permissions only for the current mm (sections are
563 * copied into each mm). During startup, this is the init_mm. Is only
564 * safe to be called with preemption disabled, as under stop_machine().
566 static inline void section_update(unsigned long addr
, pmdval_t mask
,
567 pmdval_t prot
, struct mm_struct
*mm
)
571 pmd
= pmd_offset(pud_offset(pgd_offset(mm
, addr
), addr
), addr
);
573 #ifdef CONFIG_ARM_LPAE
574 pmd
[0] = __pmd((pmd_val(pmd
[0]) & mask
) | prot
);
576 if (addr
& SECTION_SIZE
)
577 pmd
[1] = __pmd((pmd_val(pmd
[1]) & mask
) | prot
);
579 pmd
[0] = __pmd((pmd_val(pmd
[0]) & mask
) | prot
);
581 flush_pmd_entry(pmd
);
582 local_flush_tlb_kernel_range(addr
, addr
+ SECTION_SIZE
);
585 /* Make sure extended page tables are in use. */
586 static inline bool arch_has_strict_perms(void)
588 if (cpu_architecture() < CPU_ARCH_ARMv6
)
591 return !!(get_cr() & CR_XP
);
594 void set_section_perms(struct section_perm
*perms
, int n
, bool set
,
595 struct mm_struct
*mm
)
600 if (!arch_has_strict_perms())
603 for (i
= 0; i
< n
; i
++) {
604 if (!IS_ALIGNED(perms
[i
].start
, SECTION_SIZE
) ||
605 !IS_ALIGNED(perms
[i
].end
, SECTION_SIZE
)) {
606 pr_err("BUG: %s section %lx-%lx not aligned to %lx\n",
607 perms
[i
].name
, perms
[i
].start
, perms
[i
].end
,
612 for (addr
= perms
[i
].start
;
614 addr
+= SECTION_SIZE
)
615 section_update(addr
, perms
[i
].mask
,
616 set
? perms
[i
].prot
: perms
[i
].clear
, mm
);
622 * update_sections_early intended to be called only through stop_machine
623 * framework and executed by only one CPU while all other CPUs will spin and
624 * wait, so no locking is required in this function.
626 static void update_sections_early(struct section_perm perms
[], int n
)
628 struct task_struct
*t
, *s
;
630 for_each_process(t
) {
631 if (t
->flags
& PF_KTHREAD
)
633 for_each_thread(t
, s
)
634 set_section_perms(perms
, n
, true, s
->mm
);
636 set_section_perms(perms
, n
, true, current
->active_mm
);
637 set_section_perms(perms
, n
, true, &init_mm
);
640 static int __fix_kernmem_perms(void *unused
)
642 update_sections_early(nx_perms
, ARRAY_SIZE(nx_perms
));
646 static void fix_kernmem_perms(void)
648 stop_machine(__fix_kernmem_perms
, NULL
, NULL
);
651 static int __mark_rodata_ro(void *unused
)
653 update_sections_early(ro_perms
, ARRAY_SIZE(ro_perms
));
657 static int kernel_set_to_readonly __read_mostly
;
659 void mark_rodata_ro(void)
661 kernel_set_to_readonly
= 1;
662 stop_machine(__mark_rodata_ro
, NULL
, NULL
);
666 void set_kernel_text_rw(void)
668 if (!kernel_set_to_readonly
)
671 set_section_perms(ro_perms
, ARRAY_SIZE(ro_perms
), false,
675 void set_kernel_text_ro(void)
677 if (!kernel_set_to_readonly
)
680 set_section_perms(ro_perms
, ARRAY_SIZE(ro_perms
), true,
685 static inline void fix_kernmem_perms(void) { }
686 #endif /* CONFIG_STRICT_KERNEL_RWX */
688 void free_initmem(void)
692 poison_init_mem(__init_begin
, __init_end
- __init_begin
);
693 if (!machine_is_integrator() && !machine_is_cintegrator())
694 free_initmem_default(-1);
697 #ifdef CONFIG_BLK_DEV_INITRD
699 static int keep_initrd
;
701 void free_initrd_mem(unsigned long start
, unsigned long end
)
704 if (start
== initrd_start
)
705 start
= round_down(start
, PAGE_SIZE
);
706 if (end
== initrd_end
)
707 end
= round_up(end
, PAGE_SIZE
);
709 poison_init_mem((void *)start
, PAGE_ALIGN(end
) - start
);
710 free_reserved_area((void *)start
, (void *)end
, -1, "initrd");
714 static int __init
keepinitrd_setup(char *__unused
)
720 __setup("keepinitrd", keepinitrd_setup
);