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/bootmem.h>
15 #include <linux/mman.h>
16 #include <linux/export.h>
17 #include <linux/nodemask.h>
18 #include <linux/initrd.h>
19 #include <linux/of_fdt.h>
20 #include <linux/highmem.h>
21 #include <linux/gfp.h>
22 #include <linux/memblock.h>
23 #include <linux/dma-contiguous.h>
24 #include <linux/sizes.h>
25 #include <linux/stop_machine.h>
28 #include <asm/mach-types.h>
29 #include <asm/memblock.h>
30 #include <asm/memory.h>
32 #include <asm/sections.h>
33 #include <asm/setup.h>
34 #include <asm/system_info.h>
36 #include <asm/fixmap.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 static phys_addr_t phys_initrd_start __initdata
= 0;
52 static unsigned long phys_initrd_size __initdata
= 0;
54 static int __init
early_initrd(char *p
)
60 start
= memparse(p
, &endp
);
62 size
= memparse(endp
+ 1, NULL
);
64 phys_initrd_start
= start
;
65 phys_initrd_size
= size
;
69 early_param("initrd", early_initrd
);
71 static int __init
parse_tag_initrd(const struct tag
*tag
)
73 pr_warn("ATAG_INITRD is deprecated; "
74 "please update your bootloader.\n");
75 phys_initrd_start
= __virt_to_phys(tag
->u
.initrd
.start
);
76 phys_initrd_size
= tag
->u
.initrd
.size
;
80 __tagtable(ATAG_INITRD
, parse_tag_initrd
);
82 static int __init
parse_tag_initrd2(const struct tag
*tag
)
84 phys_initrd_start
= tag
->u
.initrd
.start
;
85 phys_initrd_size
= tag
->u
.initrd
.size
;
89 __tagtable(ATAG_INITRD2
, parse_tag_initrd2
);
91 static void __init
find_limits(unsigned long *min
, unsigned long *max_low
,
92 unsigned long *max_high
)
94 *max_low
= PFN_DOWN(memblock_get_current_limit());
95 *min
= PFN_UP(memblock_start_of_DRAM());
96 *max_high
= PFN_DOWN(memblock_end_of_DRAM());
99 #ifdef CONFIG_ZONE_DMA
101 phys_addr_t arm_dma_zone_size __read_mostly
;
102 EXPORT_SYMBOL(arm_dma_zone_size
);
105 * The DMA mask corresponding to the maximum bus address allocatable
106 * using GFP_DMA. The default here places no restriction on DMA
107 * allocations. This must be the smallest DMA mask in the system,
108 * so a successful GFP_DMA allocation will always satisfy this.
110 phys_addr_t arm_dma_limit
;
111 unsigned long arm_dma_pfn_limit
;
113 static void __init
arm_adjust_dma_zone(unsigned long *size
, unsigned long *hole
,
114 unsigned long dma_size
)
116 if (size
[0] <= dma_size
)
119 size
[ZONE_NORMAL
] = size
[0] - dma_size
;
120 size
[ZONE_DMA
] = dma_size
;
121 hole
[ZONE_NORMAL
] = hole
[0];
126 void __init
setup_dma_zone(const struct machine_desc
*mdesc
)
128 #ifdef CONFIG_ZONE_DMA
129 if (mdesc
->dma_zone_size
) {
130 arm_dma_zone_size
= mdesc
->dma_zone_size
;
131 arm_dma_limit
= PHYS_OFFSET
+ arm_dma_zone_size
- 1;
133 arm_dma_limit
= 0xffffffff;
134 arm_dma_pfn_limit
= arm_dma_limit
>> PAGE_SHIFT
;
138 static void __init
zone_sizes_init(unsigned long min
, unsigned long max_low
,
139 unsigned long max_high
)
141 unsigned long zone_size
[MAX_NR_ZONES
], zhole_size
[MAX_NR_ZONES
];
142 struct memblock_region
*reg
;
145 * initialise the zones.
147 memset(zone_size
, 0, sizeof(zone_size
));
150 * The memory size has already been determined. If we need
151 * to do anything fancy with the allocation of this memory
152 * to the zones, now is the time to do it.
154 zone_size
[0] = max_low
- min
;
155 #ifdef CONFIG_HIGHMEM
156 zone_size
[ZONE_HIGHMEM
] = max_high
- max_low
;
160 * Calculate the size of the holes.
161 * holes = node_size - sum(bank_sizes)
163 memcpy(zhole_size
, zone_size
, sizeof(zhole_size
));
164 for_each_memblock(memory
, reg
) {
165 unsigned long start
= memblock_region_memory_base_pfn(reg
);
166 unsigned long end
= memblock_region_memory_end_pfn(reg
);
168 if (start
< max_low
) {
169 unsigned long low_end
= min(end
, max_low
);
170 zhole_size
[0] -= low_end
- start
;
172 #ifdef CONFIG_HIGHMEM
174 unsigned long high_start
= max(start
, max_low
);
175 zhole_size
[ZONE_HIGHMEM
] -= end
- high_start
;
180 #ifdef CONFIG_ZONE_DMA
182 * Adjust the sizes according to any special requirements for
185 if (arm_dma_zone_size
)
186 arm_adjust_dma_zone(zone_size
, zhole_size
,
187 arm_dma_zone_size
>> PAGE_SHIFT
);
190 free_area_init_node(0, zone_size
, min
, zhole_size
);
193 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
194 int pfn_valid(unsigned long pfn
)
196 return memblock_is_map_memory(__pfn_to_phys(pfn
));
198 EXPORT_SYMBOL(pfn_valid
);
201 #ifndef CONFIG_SPARSEMEM
202 static void __init
arm_memory_present(void)
206 static void __init
arm_memory_present(void)
208 struct memblock_region
*reg
;
210 for_each_memblock(memory
, reg
)
211 memory_present(0, memblock_region_memory_base_pfn(reg
),
212 memblock_region_memory_end_pfn(reg
));
216 static bool arm_memblock_steal_permitted
= true;
218 phys_addr_t __init
arm_memblock_steal(phys_addr_t size
, phys_addr_t align
)
222 BUG_ON(!arm_memblock_steal_permitted
);
224 phys
= memblock_alloc_base(size
, align
, MEMBLOCK_ALLOC_ANYWHERE
);
225 memblock_free(phys
, size
);
226 memblock_remove(phys
, size
);
231 static void __init
arm_initrd_init(void)
233 #ifdef CONFIG_BLK_DEV_INITRD
237 /* FDT scan will populate initrd_start */
238 if (initrd_start
&& !phys_initrd_size
) {
239 phys_initrd_start
= __virt_to_phys(initrd_start
);
240 phys_initrd_size
= initrd_end
- initrd_start
;
243 initrd_start
= initrd_end
= 0;
245 if (!phys_initrd_size
)
249 * Round the memory region to page boundaries as per free_initrd_mem()
250 * This allows us to detect whether the pages overlapping the initrd
251 * are in use, but more importantly, reserves the entire set of pages
252 * as we don't want these pages allocated for other purposes.
254 start
= round_down(phys_initrd_start
, PAGE_SIZE
);
255 size
= phys_initrd_size
+ (phys_initrd_start
- start
);
256 size
= round_up(size
, PAGE_SIZE
);
258 if (!memblock_is_region_memory(start
, size
)) {
259 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
264 if (memblock_is_region_reserved(start
, size
)) {
265 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
270 memblock_reserve(start
, size
);
272 /* Now convert initrd to virtual addresses */
273 initrd_start
= __phys_to_virt(phys_initrd_start
);
274 initrd_end
= initrd_start
+ phys_initrd_size
;
278 void __init
arm_memblock_init(const struct machine_desc
*mdesc
)
280 /* Register the kernel text, kernel data and initrd with memblock. */
281 memblock_reserve(__pa(KERNEL_START
), KERNEL_END
- KERNEL_START
);
285 arm_mm_memblock_reserve();
287 /* reserve any platform specific memblock areas */
291 early_init_fdt_reserve_self();
292 early_init_fdt_scan_reserved_mem();
294 /* reserve memory for DMA contiguous allocations */
295 dma_contiguous_reserve(arm_dma_limit
);
297 arm_memblock_steal_permitted
= false;
301 void __init
bootmem_init(void)
303 unsigned long min
, max_low
, max_high
;
305 memblock_allow_resize();
306 max_low
= max_high
= 0;
308 find_limits(&min
, &max_low
, &max_high
);
310 early_memtest((phys_addr_t
)min
<< PAGE_SHIFT
,
311 (phys_addr_t
)max_low
<< PAGE_SHIFT
);
314 * Sparsemem tries to allocate bootmem in memory_present(),
315 * so must be done after the fixed reservations
317 arm_memory_present();
320 * sparse_init() needs the bootmem allocator up and running.
325 * Now free the memory - free_area_init_node needs
326 * the sparse mem_map arrays initialized by sparse_init()
327 * for memmap_init_zone(), otherwise all PFNs are invalid.
329 zone_sizes_init(min
, max_low
, max_high
);
332 * This doesn't seem to be used by the Linux memory manager any
333 * more, but is used by ll_rw_block. If we can get rid of it, we
334 * also get rid of some of the stuff above as well.
337 max_low_pfn
= max_low
;
342 * Poison init memory with an undefined instruction (ARM) or a branch to an
343 * undefined instruction (Thumb).
345 static inline void poison_init_mem(void *s
, size_t count
)
348 for (; count
!= 0; count
-= 4)
353 free_memmap(unsigned long start_pfn
, unsigned long end_pfn
)
355 struct page
*start_pg
, *end_pg
;
356 phys_addr_t pg
, pgend
;
359 * Convert start_pfn/end_pfn to a struct page pointer.
361 start_pg
= pfn_to_page(start_pfn
- 1) + 1;
362 end_pg
= pfn_to_page(end_pfn
- 1) + 1;
365 * Convert to physical addresses, and
366 * round start upwards and end downwards.
368 pg
= PAGE_ALIGN(__pa(start_pg
));
369 pgend
= __pa(end_pg
) & PAGE_MASK
;
372 * If there are free pages between these,
373 * free the section of the memmap array.
376 memblock_free_early(pg
, pgend
- pg
);
380 * The mem_map array can get very big. Free the unused area of the memory map.
382 static void __init
free_unused_memmap(void)
384 unsigned long start
, prev_end
= 0;
385 struct memblock_region
*reg
;
388 * This relies on each bank being in address order.
389 * The banks are sorted previously in bootmem_init().
391 for_each_memblock(memory
, reg
) {
392 start
= memblock_region_memory_base_pfn(reg
);
394 #ifdef CONFIG_SPARSEMEM
396 * Take care not to free memmap entries that don't exist
397 * due to SPARSEMEM sections which aren't present.
400 ALIGN(prev_end
, PAGES_PER_SECTION
));
403 * Align down here since the VM subsystem insists that the
404 * memmap entries are valid from the bank start aligned to
405 * MAX_ORDER_NR_PAGES.
407 start
= round_down(start
, MAX_ORDER_NR_PAGES
);
410 * If we had a previous bank, and there is a space
411 * between the current bank and the previous, free it.
413 if (prev_end
&& prev_end
< start
)
414 free_memmap(prev_end
, start
);
417 * Align up here since the VM subsystem insists that the
418 * memmap entries are valid from the bank end aligned to
419 * MAX_ORDER_NR_PAGES.
421 prev_end
= ALIGN(memblock_region_memory_end_pfn(reg
),
425 #ifdef CONFIG_SPARSEMEM
426 if (!IS_ALIGNED(prev_end
, PAGES_PER_SECTION
))
427 free_memmap(prev_end
,
428 ALIGN(prev_end
, PAGES_PER_SECTION
));
432 #ifdef CONFIG_HIGHMEM
433 static inline void free_area_high(unsigned long pfn
, unsigned long end
)
435 for (; pfn
< end
; pfn
++)
436 free_highmem_page(pfn_to_page(pfn
));
440 static void __init
free_highpages(void)
442 #ifdef CONFIG_HIGHMEM
443 unsigned long max_low
= max_low_pfn
;
444 struct memblock_region
*mem
, *res
;
446 /* set highmem page free */
447 for_each_memblock(memory
, mem
) {
448 unsigned long start
= memblock_region_memory_base_pfn(mem
);
449 unsigned long end
= memblock_region_memory_end_pfn(mem
);
451 /* Ignore complete lowmem entries */
455 if (memblock_is_nomap(mem
))
458 /* Truncate partial highmem entries */
462 /* Find and exclude any reserved regions */
463 for_each_memblock(reserved
, res
) {
464 unsigned long res_start
, res_end
;
466 res_start
= memblock_region_reserved_base_pfn(res
);
467 res_end
= memblock_region_reserved_end_pfn(res
);
471 if (res_start
< start
)
477 if (res_start
!= start
)
478 free_area_high(start
, res_start
);
484 /* And now free anything which remains */
486 free_area_high(start
, end
);
492 * mem_init() marks the free areas in the mem_map and tells us how much
493 * memory is free. This is done after various parts of the system have
494 * claimed their memory after the kernel image.
496 void __init
mem_init(void)
498 #ifdef CONFIG_HAVE_TCM
499 /* These pointers are filled in on TCM detection */
504 set_max_mapnr(pfn_to_page(max_pfn
) - mem_map
);
506 /* this will put all unused low memory onto the freelists */
507 free_unused_memmap();
511 /* now that our DMA memory is actually so designated, we can free it */
512 free_reserved_area(__va(PHYS_OFFSET
), swapper_pg_dir
, -1, NULL
);
517 mem_init_print_info(NULL
);
519 #define MLK(b, t) b, t, ((t) - (b)) >> 10
520 #define MLM(b, t) b, t, ((t) - (b)) >> 20
521 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
523 pr_notice("Virtual kernel memory layout:\n"
524 " vector : 0x%08lx - 0x%08lx (%4ld kB)\n"
525 #ifdef CONFIG_HAVE_TCM
526 " DTCM : 0x%08lx - 0x%08lx (%4ld kB)\n"
527 " ITCM : 0x%08lx - 0x%08lx (%4ld kB)\n"
529 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
530 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
531 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
532 #ifdef CONFIG_HIGHMEM
533 " pkmap : 0x%08lx - 0x%08lx (%4ld MB)\n"
535 #ifdef CONFIG_MODULES
536 " modules : 0x%08lx - 0x%08lx (%4ld MB)\n"
538 " .text : 0x%p" " - 0x%p" " (%4td kB)\n"
539 " .init : 0x%p" " - 0x%p" " (%4td kB)\n"
540 " .data : 0x%p" " - 0x%p" " (%4td kB)\n"
541 " .bss : 0x%p" " - 0x%p" " (%4td kB)\n",
543 MLK(VECTORS_BASE
, VECTORS_BASE
+ PAGE_SIZE
),
544 #ifdef CONFIG_HAVE_TCM
545 MLK(DTCM_OFFSET
, (unsigned long) dtcm_end
),
546 MLK(ITCM_OFFSET
, (unsigned long) itcm_end
),
548 MLK(FIXADDR_START
, FIXADDR_END
),
549 MLM(VMALLOC_START
, VMALLOC_END
),
550 MLM(PAGE_OFFSET
, (unsigned long)high_memory
),
551 #ifdef CONFIG_HIGHMEM
552 MLM(PKMAP_BASE
, (PKMAP_BASE
) + (LAST_PKMAP
) *
555 #ifdef CONFIG_MODULES
556 MLM(MODULES_VADDR
, MODULES_END
),
559 MLK_ROUNDUP(_text
, _etext
),
560 MLK_ROUNDUP(__init_begin
, __init_end
),
561 MLK_ROUNDUP(_sdata
, _edata
),
562 MLK_ROUNDUP(__bss_start
, __bss_stop
));
569 * Check boundaries twice: Some fundamental inconsistencies can
570 * be detected at build time already.
573 BUILD_BUG_ON(TASK_SIZE
> MODULES_VADDR
);
574 BUG_ON(TASK_SIZE
> MODULES_VADDR
);
577 #ifdef CONFIG_HIGHMEM
578 BUILD_BUG_ON(PKMAP_BASE
+ LAST_PKMAP
* PAGE_SIZE
> PAGE_OFFSET
);
579 BUG_ON(PKMAP_BASE
+ LAST_PKMAP
* PAGE_SIZE
> PAGE_OFFSET
);
582 if (PAGE_SIZE
>= 16384 && get_num_physpages() <= 128) {
583 extern int sysctl_overcommit_memory
;
585 * On a machine this small we won't get
586 * anywhere without overcommit, so turn
589 sysctl_overcommit_memory
= OVERCOMMIT_ALWAYS
;
593 #ifdef CONFIG_STRICT_KERNEL_RWX
594 struct section_perm
{
603 /* First section-aligned location at or after __start_rodata. */
604 extern char __start_rodata_section_aligned
[];
606 static struct section_perm nx_perms
[] = {
607 /* Make pages tables, etc before _stext RW (set NX). */
609 .name
= "pre-text NX",
610 .start
= PAGE_OFFSET
,
611 .end
= (unsigned long)_stext
,
612 .mask
= ~PMD_SECT_XN
,
615 /* Make init RW (set NX). */
618 .start
= (unsigned long)__init_begin
,
619 .end
= (unsigned long)_sdata
,
620 .mask
= ~PMD_SECT_XN
,
623 /* Make rodata NX (set RO in ro_perms below). */
626 .start
= (unsigned long)__start_rodata_section_aligned
,
627 .end
= (unsigned long)__init_begin
,
628 .mask
= ~PMD_SECT_XN
,
633 static struct section_perm ro_perms
[] = {
634 /* Make kernel code and rodata RX (set RO). */
636 .name
= "text/rodata RO",
637 .start
= (unsigned long)_stext
,
638 .end
= (unsigned long)__init_begin
,
639 #ifdef CONFIG_ARM_LPAE
640 .mask
= ~L_PMD_SECT_RDONLY
,
641 .prot
= L_PMD_SECT_RDONLY
,
643 .mask
= ~(PMD_SECT_APX
| PMD_SECT_AP_WRITE
),
644 .prot
= PMD_SECT_APX
| PMD_SECT_AP_WRITE
,
645 .clear
= PMD_SECT_AP_WRITE
,
651 * Updates section permissions only for the current mm (sections are
652 * copied into each mm). During startup, this is the init_mm. Is only
653 * safe to be called with preemption disabled, as under stop_machine().
655 static inline void section_update(unsigned long addr
, pmdval_t mask
,
656 pmdval_t prot
, struct mm_struct
*mm
)
660 pmd
= pmd_offset(pud_offset(pgd_offset(mm
, addr
), addr
), addr
);
662 #ifdef CONFIG_ARM_LPAE
663 pmd
[0] = __pmd((pmd_val(pmd
[0]) & mask
) | prot
);
665 if (addr
& SECTION_SIZE
)
666 pmd
[1] = __pmd((pmd_val(pmd
[1]) & mask
) | prot
);
668 pmd
[0] = __pmd((pmd_val(pmd
[0]) & mask
) | prot
);
670 flush_pmd_entry(pmd
);
671 local_flush_tlb_kernel_range(addr
, addr
+ SECTION_SIZE
);
674 /* Make sure extended page tables are in use. */
675 static inline bool arch_has_strict_perms(void)
677 if (cpu_architecture() < CPU_ARCH_ARMv6
)
680 return !!(get_cr() & CR_XP
);
683 void set_section_perms(struct section_perm
*perms
, int n
, bool set
,
684 struct mm_struct
*mm
)
689 if (!arch_has_strict_perms())
692 for (i
= 0; i
< n
; i
++) {
693 if (!IS_ALIGNED(perms
[i
].start
, SECTION_SIZE
) ||
694 !IS_ALIGNED(perms
[i
].end
, SECTION_SIZE
)) {
695 pr_err("BUG: %s section %lx-%lx not aligned to %lx\n",
696 perms
[i
].name
, perms
[i
].start
, perms
[i
].end
,
701 for (addr
= perms
[i
].start
;
703 addr
+= SECTION_SIZE
)
704 section_update(addr
, perms
[i
].mask
,
705 set
? perms
[i
].prot
: perms
[i
].clear
, mm
);
710 static void update_sections_early(struct section_perm perms
[], int n
)
712 struct task_struct
*t
, *s
;
714 read_lock(&tasklist_lock
);
715 for_each_process(t
) {
716 if (t
->flags
& PF_KTHREAD
)
718 for_each_thread(t
, s
)
719 set_section_perms(perms
, n
, true, s
->mm
);
721 read_unlock(&tasklist_lock
);
722 set_section_perms(perms
, n
, true, current
->active_mm
);
723 set_section_perms(perms
, n
, true, &init_mm
);
726 int __fix_kernmem_perms(void *unused
)
728 update_sections_early(nx_perms
, ARRAY_SIZE(nx_perms
));
732 void fix_kernmem_perms(void)
734 stop_machine(__fix_kernmem_perms
, NULL
, NULL
);
737 int __mark_rodata_ro(void *unused
)
739 update_sections_early(ro_perms
, ARRAY_SIZE(ro_perms
));
743 void mark_rodata_ro(void)
745 stop_machine(__mark_rodata_ro
, NULL
, NULL
);
748 void set_kernel_text_rw(void)
750 set_section_perms(ro_perms
, ARRAY_SIZE(ro_perms
), false,
754 void set_kernel_text_ro(void)
756 set_section_perms(ro_perms
, ARRAY_SIZE(ro_perms
), true,
761 static inline void fix_kernmem_perms(void) { }
762 #endif /* CONFIG_STRICT_KERNEL_RWX */
764 void free_tcmmem(void)
766 #ifdef CONFIG_HAVE_TCM
767 extern char __tcm_start
, __tcm_end
;
769 poison_init_mem(&__tcm_start
, &__tcm_end
- &__tcm_start
);
770 free_reserved_area(&__tcm_start
, &__tcm_end
, -1, "TCM link");
774 void free_initmem(void)
779 poison_init_mem(__init_begin
, __init_end
- __init_begin
);
780 if (!machine_is_integrator() && !machine_is_cintegrator())
781 free_initmem_default(-1);
784 #ifdef CONFIG_BLK_DEV_INITRD
786 static int keep_initrd
;
788 void free_initrd_mem(unsigned long start
, unsigned long end
)
791 if (start
== initrd_start
)
792 start
= round_down(start
, PAGE_SIZE
);
793 if (end
== initrd_end
)
794 end
= round_up(end
, PAGE_SIZE
);
796 poison_init_mem((void *)start
, PAGE_ALIGN(end
) - start
);
797 free_reserved_area((void *)start
, (void *)end
, -1, "initrd");
801 static int __init
keepinitrd_setup(char *__unused
)
807 __setup("keepinitrd", keepinitrd_setup
);