2 * linux/arch/x86_64/mm/init.c
4 * Copyright (C) 1995 Linus Torvalds
5 * Copyright (C) 2000 Pavel Machek <pavel@ucw.cz>
6 * Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
9 #include <linux/signal.h>
10 #include <linux/sched.h>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/string.h>
14 #include <linux/types.h>
15 #include <linux/ptrace.h>
16 #include <linux/mman.h>
18 #include <linux/swap.h>
19 #include <linux/smp.h>
20 #include <linux/init.h>
21 #include <linux/initrd.h>
22 #include <linux/pagemap.h>
23 #include <linux/bootmem.h>
24 #include <linux/memblock.h>
25 #include <linux/proc_fs.h>
26 #include <linux/pci.h>
27 #include <linux/pfn.h>
28 #include <linux/poison.h>
29 #include <linux/dma-mapping.h>
30 #include <linux/module.h>
31 #include <linux/memory.h>
32 #include <linux/memory_hotplug.h>
33 #include <linux/memremap.h>
34 #include <linux/nmi.h>
35 #include <linux/gfp.h>
36 #include <linux/kcore.h>
38 #include <asm/processor.h>
39 #include <asm/bios_ebda.h>
40 #include <asm/uaccess.h>
41 #include <asm/pgtable.h>
42 #include <asm/pgalloc.h>
44 #include <asm/fixmap.h>
48 #include <asm/mmu_context.h>
49 #include <asm/proto.h>
51 #include <asm/sections.h>
52 #include <asm/kdebug.h>
54 #include <asm/cacheflush.h>
56 #include <asm/uv/uv.h>
57 #include <asm/setup.h>
59 #include "mm_internal.h"
61 #include "ident_map.c"
64 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
65 * physical space so we can cache the place of the first one and move
66 * around without checking the pgd every time.
69 pteval_t __supported_pte_mask __read_mostly
= ~0;
70 EXPORT_SYMBOL_GPL(__supported_pte_mask
);
72 int force_personality32
;
76 * Control non executable heap for 32bit processes.
77 * To control the stack too use noexec=off
79 * on PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
80 * off PROT_READ implies PROT_EXEC
82 static int __init
nonx32_setup(char *str
)
84 if (!strcmp(str
, "on"))
85 force_personality32
&= ~READ_IMPLIES_EXEC
;
86 else if (!strcmp(str
, "off"))
87 force_personality32
|= READ_IMPLIES_EXEC
;
90 __setup("noexec32=", nonx32_setup
);
93 * When memory was added/removed make sure all the processes MM have
94 * suitable PGD entries in the local PGD level page.
96 void sync_global_pgds(unsigned long start
, unsigned long end
, int removed
)
98 unsigned long address
;
100 for (address
= start
; address
<= end
; address
+= PGDIR_SIZE
) {
101 const pgd_t
*pgd_ref
= pgd_offset_k(address
);
105 * When it is called after memory hot remove, pgd_none()
106 * returns true. In this case (removed == 1), we must clear
107 * the PGD entries in the local PGD level page.
109 if (pgd_none(*pgd_ref
) && !removed
)
112 spin_lock(&pgd_lock
);
113 list_for_each_entry(page
, &pgd_list
, lru
) {
115 spinlock_t
*pgt_lock
;
117 pgd
= (pgd_t
*)page_address(page
) + pgd_index(address
);
118 /* the pgt_lock only for Xen */
119 pgt_lock
= &pgd_page_get_mm(page
)->page_table_lock
;
122 if (!pgd_none(*pgd_ref
) && !pgd_none(*pgd
))
123 BUG_ON(pgd_page_vaddr(*pgd
)
124 != pgd_page_vaddr(*pgd_ref
));
127 if (pgd_none(*pgd_ref
) && !pgd_none(*pgd
))
131 set_pgd(pgd
, *pgd_ref
);
134 spin_unlock(pgt_lock
);
136 spin_unlock(&pgd_lock
);
141 * NOTE: This function is marked __ref because it calls __init function
142 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
144 static __ref
void *spp_getpage(void)
149 ptr
= (void *) get_zeroed_page(GFP_ATOMIC
| __GFP_NOTRACK
);
151 ptr
= alloc_bootmem_pages(PAGE_SIZE
);
153 if (!ptr
|| ((unsigned long)ptr
& ~PAGE_MASK
)) {
154 panic("set_pte_phys: cannot allocate page data %s\n",
155 after_bootmem
? "after bootmem" : "");
158 pr_debug("spp_getpage %p\n", ptr
);
163 static pud_t
*fill_pud(pgd_t
*pgd
, unsigned long vaddr
)
165 if (pgd_none(*pgd
)) {
166 pud_t
*pud
= (pud_t
*)spp_getpage();
167 pgd_populate(&init_mm
, pgd
, pud
);
168 if (pud
!= pud_offset(pgd
, 0))
169 printk(KERN_ERR
"PAGETABLE BUG #00! %p <-> %p\n",
170 pud
, pud_offset(pgd
, 0));
172 return pud_offset(pgd
, vaddr
);
175 static pmd_t
*fill_pmd(pud_t
*pud
, unsigned long vaddr
)
177 if (pud_none(*pud
)) {
178 pmd_t
*pmd
= (pmd_t
*) spp_getpage();
179 pud_populate(&init_mm
, pud
, pmd
);
180 if (pmd
!= pmd_offset(pud
, 0))
181 printk(KERN_ERR
"PAGETABLE BUG #01! %p <-> %p\n",
182 pmd
, pmd_offset(pud
, 0));
184 return pmd_offset(pud
, vaddr
);
187 static pte_t
*fill_pte(pmd_t
*pmd
, unsigned long vaddr
)
189 if (pmd_none(*pmd
)) {
190 pte_t
*pte
= (pte_t
*) spp_getpage();
191 pmd_populate_kernel(&init_mm
, pmd
, pte
);
192 if (pte
!= pte_offset_kernel(pmd
, 0))
193 printk(KERN_ERR
"PAGETABLE BUG #02!\n");
195 return pte_offset_kernel(pmd
, vaddr
);
198 void set_pte_vaddr_pud(pud_t
*pud_page
, unsigned long vaddr
, pte_t new_pte
)
204 pud
= pud_page
+ pud_index(vaddr
);
205 pmd
= fill_pmd(pud
, vaddr
);
206 pte
= fill_pte(pmd
, vaddr
);
208 set_pte(pte
, new_pte
);
211 * It's enough to flush this one mapping.
212 * (PGE mappings get flushed as well)
214 __flush_tlb_one(vaddr
);
217 void set_pte_vaddr(unsigned long vaddr
, pte_t pteval
)
222 pr_debug("set_pte_vaddr %lx to %lx\n", vaddr
, native_pte_val(pteval
));
224 pgd
= pgd_offset_k(vaddr
);
225 if (pgd_none(*pgd
)) {
227 "PGD FIXMAP MISSING, it should be setup in head.S!\n");
230 pud_page
= (pud_t
*)pgd_page_vaddr(*pgd
);
231 set_pte_vaddr_pud(pud_page
, vaddr
, pteval
);
234 pmd_t
* __init
populate_extra_pmd(unsigned long vaddr
)
239 pgd
= pgd_offset_k(vaddr
);
240 pud
= fill_pud(pgd
, vaddr
);
241 return fill_pmd(pud
, vaddr
);
244 pte_t
* __init
populate_extra_pte(unsigned long vaddr
)
248 pmd
= populate_extra_pmd(vaddr
);
249 return fill_pte(pmd
, vaddr
);
253 * Create large page table mappings for a range of physical addresses.
255 static void __init
__init_extra_mapping(unsigned long phys
, unsigned long size
,
256 enum page_cache_mode cache
)
263 pgprot_val(prot
) = pgprot_val(PAGE_KERNEL_LARGE
) |
264 pgprot_val(pgprot_4k_2_large(cachemode2pgprot(cache
)));
265 BUG_ON((phys
& ~PMD_MASK
) || (size
& ~PMD_MASK
));
266 for (; size
; phys
+= PMD_SIZE
, size
-= PMD_SIZE
) {
267 pgd
= pgd_offset_k((unsigned long)__va(phys
));
268 if (pgd_none(*pgd
)) {
269 pud
= (pud_t
*) spp_getpage();
270 set_pgd(pgd
, __pgd(__pa(pud
) | _KERNPG_TABLE
|
273 pud
= pud_offset(pgd
, (unsigned long)__va(phys
));
274 if (pud_none(*pud
)) {
275 pmd
= (pmd_t
*) spp_getpage();
276 set_pud(pud
, __pud(__pa(pmd
) | _KERNPG_TABLE
|
279 pmd
= pmd_offset(pud
, phys
);
280 BUG_ON(!pmd_none(*pmd
));
281 set_pmd(pmd
, __pmd(phys
| pgprot_val(prot
)));
285 void __init
init_extra_mapping_wb(unsigned long phys
, unsigned long size
)
287 __init_extra_mapping(phys
, size
, _PAGE_CACHE_MODE_WB
);
290 void __init
init_extra_mapping_uc(unsigned long phys
, unsigned long size
)
292 __init_extra_mapping(phys
, size
, _PAGE_CACHE_MODE_UC
);
296 * The head.S code sets up the kernel high mapping:
298 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
300 * phys_base holds the negative offset to the kernel, which is added
301 * to the compile time generated pmds. This results in invalid pmds up
302 * to the point where we hit the physaddr 0 mapping.
304 * We limit the mappings to the region from _text to _brk_end. _brk_end
305 * is rounded up to the 2MB boundary. This catches the invalid pmds as
306 * well, as they are located before _text:
308 void __init
cleanup_highmap(void)
310 unsigned long vaddr
= __START_KERNEL_map
;
311 unsigned long vaddr_end
= __START_KERNEL_map
+ KERNEL_IMAGE_SIZE
;
312 unsigned long end
= roundup((unsigned long)_brk_end
, PMD_SIZE
) - 1;
313 pmd_t
*pmd
= level2_kernel_pgt
;
316 * Native path, max_pfn_mapped is not set yet.
317 * Xen has valid max_pfn_mapped set in
318 * arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
321 vaddr_end
= __START_KERNEL_map
+ (max_pfn_mapped
<< PAGE_SHIFT
);
323 for (; vaddr
+ PMD_SIZE
- 1 < vaddr_end
; pmd
++, vaddr
+= PMD_SIZE
) {
326 if (vaddr
< (unsigned long) _text
|| vaddr
> end
)
327 set_pmd(pmd
, __pmd(0));
331 static unsigned long __meminit
332 phys_pte_init(pte_t
*pte_page
, unsigned long addr
, unsigned long end
,
335 unsigned long pages
= 0, next
;
336 unsigned long last_map_addr
= end
;
339 pte_t
*pte
= pte_page
+ pte_index(addr
);
341 for (i
= pte_index(addr
); i
< PTRS_PER_PTE
; i
++, addr
= next
, pte
++) {
342 next
= (addr
& PAGE_MASK
) + PAGE_SIZE
;
344 if (!after_bootmem
&&
345 !e820_any_mapped(addr
& PAGE_MASK
, next
, E820_RAM
) &&
346 !e820_any_mapped(addr
& PAGE_MASK
, next
, E820_RESERVED_KERN
))
347 set_pte(pte
, __pte(0));
352 * We will re-use the existing mapping.
353 * Xen for example has some special requirements, like mapping
354 * pagetable pages as RO. So assume someone who pre-setup
355 * these mappings are more intelligent.
357 if (!pte_none(*pte
)) {
364 printk(" pte=%p addr=%lx pte=%016lx\n",
365 pte
, addr
, pfn_pte(addr
>> PAGE_SHIFT
, PAGE_KERNEL
).pte
);
367 set_pte(pte
, pfn_pte(addr
>> PAGE_SHIFT
, prot
));
368 last_map_addr
= (addr
& PAGE_MASK
) + PAGE_SIZE
;
371 update_page_count(PG_LEVEL_4K
, pages
);
373 return last_map_addr
;
376 static unsigned long __meminit
377 phys_pmd_init(pmd_t
*pmd_page
, unsigned long address
, unsigned long end
,
378 unsigned long page_size_mask
, pgprot_t prot
)
380 unsigned long pages
= 0, next
;
381 unsigned long last_map_addr
= end
;
383 int i
= pmd_index(address
);
385 for (; i
< PTRS_PER_PMD
; i
++, address
= next
) {
386 pmd_t
*pmd
= pmd_page
+ pmd_index(address
);
388 pgprot_t new_prot
= prot
;
390 next
= (address
& PMD_MASK
) + PMD_SIZE
;
391 if (address
>= end
) {
392 if (!after_bootmem
&&
393 !e820_any_mapped(address
& PMD_MASK
, next
, E820_RAM
) &&
394 !e820_any_mapped(address
& PMD_MASK
, next
, E820_RESERVED_KERN
))
395 set_pmd(pmd
, __pmd(0));
399 if (!pmd_none(*pmd
)) {
400 if (!pmd_large(*pmd
)) {
401 spin_lock(&init_mm
.page_table_lock
);
402 pte
= (pte_t
*)pmd_page_vaddr(*pmd
);
403 last_map_addr
= phys_pte_init(pte
, address
,
405 spin_unlock(&init_mm
.page_table_lock
);
409 * If we are ok with PG_LEVEL_2M mapping, then we will
410 * use the existing mapping,
412 * Otherwise, we will split the large page mapping but
413 * use the same existing protection bits except for
414 * large page, so that we don't violate Intel's TLB
415 * Application note (317080) which says, while changing
416 * the page sizes, new and old translations should
417 * not differ with respect to page frame and
420 if (page_size_mask
& (1 << PG_LEVEL_2M
)) {
423 last_map_addr
= next
;
426 new_prot
= pte_pgprot(pte_clrhuge(*(pte_t
*)pmd
));
429 if (page_size_mask
& (1<<PG_LEVEL_2M
)) {
431 spin_lock(&init_mm
.page_table_lock
);
432 set_pte((pte_t
*)pmd
,
433 pfn_pte((address
& PMD_MASK
) >> PAGE_SHIFT
,
434 __pgprot(pgprot_val(prot
) | _PAGE_PSE
)));
435 spin_unlock(&init_mm
.page_table_lock
);
436 last_map_addr
= next
;
440 pte
= alloc_low_page();
441 last_map_addr
= phys_pte_init(pte
, address
, end
, new_prot
);
443 spin_lock(&init_mm
.page_table_lock
);
444 pmd_populate_kernel(&init_mm
, pmd
, pte
);
445 spin_unlock(&init_mm
.page_table_lock
);
447 update_page_count(PG_LEVEL_2M
, pages
);
448 return last_map_addr
;
451 static unsigned long __meminit
452 phys_pud_init(pud_t
*pud_page
, unsigned long addr
, unsigned long end
,
453 unsigned long page_size_mask
)
455 unsigned long pages
= 0, next
;
456 unsigned long last_map_addr
= end
;
457 int i
= pud_index(addr
);
459 for (; i
< PTRS_PER_PUD
; i
++, addr
= next
) {
460 pud_t
*pud
= pud_page
+ pud_index(addr
);
462 pgprot_t prot
= PAGE_KERNEL
;
464 next
= (addr
& PUD_MASK
) + PUD_SIZE
;
466 if (!after_bootmem
&&
467 !e820_any_mapped(addr
& PUD_MASK
, next
, E820_RAM
) &&
468 !e820_any_mapped(addr
& PUD_MASK
, next
, E820_RESERVED_KERN
))
469 set_pud(pud
, __pud(0));
473 if (!pud_none(*pud
)) {
474 if (!pud_large(*pud
)) {
475 pmd
= pmd_offset(pud
, 0);
476 last_map_addr
= phys_pmd_init(pmd
, addr
, end
,
477 page_size_mask
, prot
);
482 * If we are ok with PG_LEVEL_1G mapping, then we will
483 * use the existing mapping.
485 * Otherwise, we will split the gbpage mapping but use
486 * the same existing protection bits except for large
487 * page, so that we don't violate Intel's TLB
488 * Application note (317080) which says, while changing
489 * the page sizes, new and old translations should
490 * not differ with respect to page frame and
493 if (page_size_mask
& (1 << PG_LEVEL_1G
)) {
496 last_map_addr
= next
;
499 prot
= pte_pgprot(pte_clrhuge(*(pte_t
*)pud
));
502 if (page_size_mask
& (1<<PG_LEVEL_1G
)) {
504 spin_lock(&init_mm
.page_table_lock
);
505 set_pte((pte_t
*)pud
,
506 pfn_pte((addr
& PUD_MASK
) >> PAGE_SHIFT
,
508 spin_unlock(&init_mm
.page_table_lock
);
509 last_map_addr
= next
;
513 pmd
= alloc_low_page();
514 last_map_addr
= phys_pmd_init(pmd
, addr
, end
, page_size_mask
,
517 spin_lock(&init_mm
.page_table_lock
);
518 pud_populate(&init_mm
, pud
, pmd
);
519 spin_unlock(&init_mm
.page_table_lock
);
523 update_page_count(PG_LEVEL_1G
, pages
);
525 return last_map_addr
;
528 unsigned long __meminit
529 kernel_physical_mapping_init(unsigned long start
,
531 unsigned long page_size_mask
)
533 bool pgd_changed
= false;
534 unsigned long next
, last_map_addr
= end
;
537 start
= (unsigned long)__va(start
);
538 end
= (unsigned long)__va(end
);
541 for (; start
< end
; start
= next
) {
542 pgd_t
*pgd
= pgd_offset_k(start
);
545 next
= (start
& PGDIR_MASK
) + PGDIR_SIZE
;
548 pud
= (pud_t
*)pgd_page_vaddr(*pgd
);
549 last_map_addr
= phys_pud_init(pud
, __pa(start
),
550 __pa(end
), page_size_mask
);
554 pud
= alloc_low_page();
555 last_map_addr
= phys_pud_init(pud
, __pa(start
), __pa(end
),
558 spin_lock(&init_mm
.page_table_lock
);
559 pgd_populate(&init_mm
, pgd
, pud
);
560 spin_unlock(&init_mm
.page_table_lock
);
565 sync_global_pgds(addr
, end
- 1, 0);
569 return last_map_addr
;
573 void __init
initmem_init(void)
575 memblock_set_node(0, (phys_addr_t
)ULLONG_MAX
, &memblock
.memory
, 0);
579 void __init
paging_init(void)
581 sparse_memory_present_with_active_regions(MAX_NUMNODES
);
585 * clear the default setting with node 0
586 * note: don't use nodes_clear here, that is really clearing when
587 * numa support is not compiled in, and later node_set_state
588 * will not set it back.
590 node_clear_state(0, N_MEMORY
);
591 if (N_MEMORY
!= N_NORMAL_MEMORY
)
592 node_clear_state(0, N_NORMAL_MEMORY
);
598 * Memory hotplug specific functions
600 #ifdef CONFIG_MEMORY_HOTPLUG
602 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
605 static void update_end_of_memory_vars(u64 start
, u64 size
)
607 unsigned long end_pfn
= PFN_UP(start
+ size
);
609 if (end_pfn
> max_pfn
) {
611 max_low_pfn
= end_pfn
;
612 high_memory
= (void *)__va(max_pfn
* PAGE_SIZE
- 1) + 1;
617 * Memory is added always to NORMAL zone. This means you will never get
618 * additional DMA/DMA32 memory.
620 int arch_add_memory(int nid
, u64 start
, u64 size
, bool for_device
)
622 struct pglist_data
*pgdat
= NODE_DATA(nid
);
623 struct zone
*zone
= pgdat
->node_zones
+
624 zone_for_memory(nid
, start
, size
, ZONE_NORMAL
, for_device
);
625 unsigned long start_pfn
= start
>> PAGE_SHIFT
;
626 unsigned long nr_pages
= size
>> PAGE_SHIFT
;
629 init_memory_mapping(start
, start
+ size
);
631 ret
= __add_pages(nid
, zone
, start_pfn
, nr_pages
);
634 /* update max_pfn, max_low_pfn and high_memory */
635 update_end_of_memory_vars(start
, size
);
639 EXPORT_SYMBOL_GPL(arch_add_memory
);
641 #define PAGE_INUSE 0xFD
643 static void __meminit
free_pagetable(struct page
*page
, int order
)
646 unsigned int nr_pages
= 1 << order
;
647 struct vmem_altmap
*altmap
= to_vmem_altmap((unsigned long) page
);
650 vmem_altmap_free(altmap
, nr_pages
);
654 /* bootmem page has reserved flag */
655 if (PageReserved(page
)) {
656 __ClearPageReserved(page
);
658 magic
= (unsigned long)page
->lru
.next
;
659 if (magic
== SECTION_INFO
|| magic
== MIX_SECTION_INFO
) {
661 put_page_bootmem(page
++);
664 free_reserved_page(page
++);
666 free_pages((unsigned long)page_address(page
), order
);
669 static void __meminit
free_pte_table(pte_t
*pte_start
, pmd_t
*pmd
)
674 for (i
= 0; i
< PTRS_PER_PTE
; i
++) {
680 /* free a pte talbe */
681 free_pagetable(pmd_page(*pmd
), 0);
682 spin_lock(&init_mm
.page_table_lock
);
684 spin_unlock(&init_mm
.page_table_lock
);
687 static void __meminit
free_pmd_table(pmd_t
*pmd_start
, pud_t
*pud
)
692 for (i
= 0; i
< PTRS_PER_PMD
; i
++) {
698 /* free a pmd talbe */
699 free_pagetable(pud_page(*pud
), 0);
700 spin_lock(&init_mm
.page_table_lock
);
702 spin_unlock(&init_mm
.page_table_lock
);
705 /* Return true if pgd is changed, otherwise return false. */
706 static bool __meminit
free_pud_table(pud_t
*pud_start
, pgd_t
*pgd
)
711 for (i
= 0; i
< PTRS_PER_PUD
; i
++) {
717 /* free a pud table */
718 free_pagetable(pgd_page(*pgd
), 0);
719 spin_lock(&init_mm
.page_table_lock
);
721 spin_unlock(&init_mm
.page_table_lock
);
726 static void __meminit
727 remove_pte_table(pte_t
*pte_start
, unsigned long addr
, unsigned long end
,
730 unsigned long next
, pages
= 0;
733 phys_addr_t phys_addr
;
735 pte
= pte_start
+ pte_index(addr
);
736 for (; addr
< end
; addr
= next
, pte
++) {
737 next
= (addr
+ PAGE_SIZE
) & PAGE_MASK
;
741 if (!pte_present(*pte
))
745 * We mapped [0,1G) memory as identity mapping when
746 * initializing, in arch/x86/kernel/head_64.S. These
747 * pagetables cannot be removed.
749 phys_addr
= pte_val(*pte
) + (addr
& PAGE_MASK
);
750 if (phys_addr
< (phys_addr_t
)0x40000000)
753 if (PAGE_ALIGNED(addr
) && PAGE_ALIGNED(next
)) {
755 * Do not free direct mapping pages since they were
756 * freed when offlining, or simplely not in use.
759 free_pagetable(pte_page(*pte
), 0);
761 spin_lock(&init_mm
.page_table_lock
);
762 pte_clear(&init_mm
, addr
, pte
);
763 spin_unlock(&init_mm
.page_table_lock
);
765 /* For non-direct mapping, pages means nothing. */
769 * If we are here, we are freeing vmemmap pages since
770 * direct mapped memory ranges to be freed are aligned.
772 * If we are not removing the whole page, it means
773 * other page structs in this page are being used and
774 * we canot remove them. So fill the unused page_structs
775 * with 0xFD, and remove the page when it is wholly
778 memset((void *)addr
, PAGE_INUSE
, next
- addr
);
780 page_addr
= page_address(pte_page(*pte
));
781 if (!memchr_inv(page_addr
, PAGE_INUSE
, PAGE_SIZE
)) {
782 free_pagetable(pte_page(*pte
), 0);
784 spin_lock(&init_mm
.page_table_lock
);
785 pte_clear(&init_mm
, addr
, pte
);
786 spin_unlock(&init_mm
.page_table_lock
);
791 /* Call free_pte_table() in remove_pmd_table(). */
794 update_page_count(PG_LEVEL_4K
, -pages
);
797 static void __meminit
798 remove_pmd_table(pmd_t
*pmd_start
, unsigned long addr
, unsigned long end
,
801 unsigned long next
, pages
= 0;
806 pmd
= pmd_start
+ pmd_index(addr
);
807 for (; addr
< end
; addr
= next
, pmd
++) {
808 next
= pmd_addr_end(addr
, end
);
810 if (!pmd_present(*pmd
))
813 if (pmd_large(*pmd
)) {
814 if (IS_ALIGNED(addr
, PMD_SIZE
) &&
815 IS_ALIGNED(next
, PMD_SIZE
)) {
817 free_pagetable(pmd_page(*pmd
),
818 get_order(PMD_SIZE
));
820 spin_lock(&init_mm
.page_table_lock
);
822 spin_unlock(&init_mm
.page_table_lock
);
825 /* If here, we are freeing vmemmap pages. */
826 memset((void *)addr
, PAGE_INUSE
, next
- addr
);
828 page_addr
= page_address(pmd_page(*pmd
));
829 if (!memchr_inv(page_addr
, PAGE_INUSE
,
831 free_pagetable(pmd_page(*pmd
),
832 get_order(PMD_SIZE
));
834 spin_lock(&init_mm
.page_table_lock
);
836 spin_unlock(&init_mm
.page_table_lock
);
843 pte_base
= (pte_t
*)pmd_page_vaddr(*pmd
);
844 remove_pte_table(pte_base
, addr
, next
, direct
);
845 free_pte_table(pte_base
, pmd
);
848 /* Call free_pmd_table() in remove_pud_table(). */
850 update_page_count(PG_LEVEL_2M
, -pages
);
853 static void __meminit
854 remove_pud_table(pud_t
*pud_start
, unsigned long addr
, unsigned long end
,
857 unsigned long next
, pages
= 0;
862 pud
= pud_start
+ pud_index(addr
);
863 for (; addr
< end
; addr
= next
, pud
++) {
864 next
= pud_addr_end(addr
, end
);
866 if (!pud_present(*pud
))
869 if (pud_large(*pud
)) {
870 if (IS_ALIGNED(addr
, PUD_SIZE
) &&
871 IS_ALIGNED(next
, PUD_SIZE
)) {
873 free_pagetable(pud_page(*pud
),
874 get_order(PUD_SIZE
));
876 spin_lock(&init_mm
.page_table_lock
);
878 spin_unlock(&init_mm
.page_table_lock
);
881 /* If here, we are freeing vmemmap pages. */
882 memset((void *)addr
, PAGE_INUSE
, next
- addr
);
884 page_addr
= page_address(pud_page(*pud
));
885 if (!memchr_inv(page_addr
, PAGE_INUSE
,
887 free_pagetable(pud_page(*pud
),
888 get_order(PUD_SIZE
));
890 spin_lock(&init_mm
.page_table_lock
);
892 spin_unlock(&init_mm
.page_table_lock
);
899 pmd_base
= (pmd_t
*)pud_page_vaddr(*pud
);
900 remove_pmd_table(pmd_base
, addr
, next
, direct
);
901 free_pmd_table(pmd_base
, pud
);
905 update_page_count(PG_LEVEL_1G
, -pages
);
908 /* start and end are both virtual address. */
909 static void __meminit
910 remove_pagetable(unsigned long start
, unsigned long end
, bool direct
)
916 bool pgd_changed
= false;
918 for (addr
= start
; addr
< end
; addr
= next
) {
919 next
= pgd_addr_end(addr
, end
);
921 pgd
= pgd_offset_k(addr
);
922 if (!pgd_present(*pgd
))
925 pud
= (pud_t
*)pgd_page_vaddr(*pgd
);
926 remove_pud_table(pud
, addr
, next
, direct
);
927 if (free_pud_table(pud
, pgd
))
932 sync_global_pgds(start
, end
- 1, 1);
937 void __ref
vmemmap_free(unsigned long start
, unsigned long end
)
939 remove_pagetable(start
, end
, false);
942 #ifdef CONFIG_MEMORY_HOTREMOVE
943 static void __meminit
944 kernel_physical_mapping_remove(unsigned long start
, unsigned long end
)
946 start
= (unsigned long)__va(start
);
947 end
= (unsigned long)__va(end
);
949 remove_pagetable(start
, end
, true);
952 int __ref
arch_remove_memory(u64 start
, u64 size
)
954 unsigned long start_pfn
= start
>> PAGE_SHIFT
;
955 unsigned long nr_pages
= size
>> PAGE_SHIFT
;
956 struct page
*page
= pfn_to_page(start_pfn
);
957 struct vmem_altmap
*altmap
;
961 /* With altmap the first mapped page is offset from @start */
962 altmap
= to_vmem_altmap((unsigned long) page
);
964 page
+= vmem_altmap_offset(altmap
);
965 zone
= page_zone(page
);
966 ret
= __remove_pages(zone
, start_pfn
, nr_pages
);
968 kernel_physical_mapping_remove(start
, start
+ size
);
973 #endif /* CONFIG_MEMORY_HOTPLUG */
975 static struct kcore_list kcore_vsyscall
;
977 static void __init
register_page_bootmem_info(void)
982 for_each_online_node(i
)
983 register_page_bootmem_info_node(NODE_DATA(i
));
987 void __init
mem_init(void)
991 /* clear_bss() already clear the empty_zero_page */
993 register_page_bootmem_info();
995 /* this will put all memory onto the freelists */
999 /* Register memory areas for /proc/kcore */
1000 kclist_add(&kcore_vsyscall
, (void *)VSYSCALL_ADDR
,
1001 PAGE_SIZE
, KCORE_OTHER
);
1003 mem_init_print_info(NULL
);
1006 const int rodata_test_data
= 0xC3;
1007 EXPORT_SYMBOL_GPL(rodata_test_data
);
1009 int kernel_set_to_readonly
;
1011 void set_kernel_text_rw(void)
1013 unsigned long start
= PFN_ALIGN(_text
);
1014 unsigned long end
= PFN_ALIGN(__stop___ex_table
);
1016 if (!kernel_set_to_readonly
)
1019 pr_debug("Set kernel text: %lx - %lx for read write\n",
1023 * Make the kernel identity mapping for text RW. Kernel text
1024 * mapping will always be RO. Refer to the comment in
1025 * static_protections() in pageattr.c
1027 set_memory_rw(start
, (end
- start
) >> PAGE_SHIFT
);
1030 void set_kernel_text_ro(void)
1032 unsigned long start
= PFN_ALIGN(_text
);
1033 unsigned long end
= PFN_ALIGN(__stop___ex_table
);
1035 if (!kernel_set_to_readonly
)
1038 pr_debug("Set kernel text: %lx - %lx for read only\n",
1042 * Set the kernel identity mapping for text RO.
1044 set_memory_ro(start
, (end
- start
) >> PAGE_SHIFT
);
1047 void mark_rodata_ro(void)
1049 unsigned long start
= PFN_ALIGN(_text
);
1050 unsigned long rodata_start
= PFN_ALIGN(__start_rodata
);
1051 unsigned long end
= (unsigned long) &__end_rodata_hpage_align
;
1052 unsigned long text_end
= PFN_ALIGN(&__stop___ex_table
);
1053 unsigned long rodata_end
= PFN_ALIGN(&__end_rodata
);
1054 unsigned long all_end
;
1056 printk(KERN_INFO
"Write protecting the kernel read-only data: %luk\n",
1057 (end
- start
) >> 10);
1058 set_memory_ro(start
, (end
- start
) >> PAGE_SHIFT
);
1060 kernel_set_to_readonly
= 1;
1063 * The rodata/data/bss/brk section (but not the kernel text!)
1064 * should also be not-executable.
1066 * We align all_end to PMD_SIZE because the existing mapping
1067 * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1068 * split the PMD and the reminder between _brk_end and the end
1069 * of the PMD will remain mapped executable.
1071 * Any PMD which was setup after the one which covers _brk_end
1072 * has been zapped already via cleanup_highmem().
1074 all_end
= roundup((unsigned long)_brk_end
, PMD_SIZE
);
1075 set_memory_nx(text_end
, (all_end
- text_end
) >> PAGE_SHIFT
);
1079 #ifdef CONFIG_CPA_DEBUG
1080 printk(KERN_INFO
"Testing CPA: undo %lx-%lx\n", start
, end
);
1081 set_memory_rw(start
, (end
-start
) >> PAGE_SHIFT
);
1083 printk(KERN_INFO
"Testing CPA: again\n");
1084 set_memory_ro(start
, (end
-start
) >> PAGE_SHIFT
);
1087 free_init_pages("unused kernel",
1088 (unsigned long) __va(__pa_symbol(text_end
)),
1089 (unsigned long) __va(__pa_symbol(rodata_start
)));
1090 free_init_pages("unused kernel",
1091 (unsigned long) __va(__pa_symbol(rodata_end
)),
1092 (unsigned long) __va(__pa_symbol(_sdata
)));
1097 int kern_addr_valid(unsigned long addr
)
1099 unsigned long above
= ((long)addr
) >> __VIRTUAL_MASK_SHIFT
;
1105 if (above
!= 0 && above
!= -1UL)
1108 pgd
= pgd_offset_k(addr
);
1112 pud
= pud_offset(pgd
, addr
);
1116 if (pud_large(*pud
))
1117 return pfn_valid(pud_pfn(*pud
));
1119 pmd
= pmd_offset(pud
, addr
);
1123 if (pmd_large(*pmd
))
1124 return pfn_valid(pmd_pfn(*pmd
));
1126 pte
= pte_offset_kernel(pmd
, addr
);
1130 return pfn_valid(pte_pfn(*pte
));
1133 static unsigned long probe_memory_block_size(void)
1135 unsigned long bz
= MIN_MEMORY_BLOCK_SIZE
;
1137 /* if system is UV or has 64GB of RAM or more, use large blocks */
1138 if (is_uv_system() || ((max_pfn
<< PAGE_SHIFT
) >= (64UL << 30)))
1139 bz
= 2UL << 30; /* 2GB */
1141 pr_info("x86/mm: Memory block size: %ldMB\n", bz
>> 20);
1146 static unsigned long memory_block_size_probed
;
1147 unsigned long memory_block_size_bytes(void)
1149 if (!memory_block_size_probed
)
1150 memory_block_size_probed
= probe_memory_block_size();
1152 return memory_block_size_probed
;
1155 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1157 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1159 static long __meminitdata addr_start
, addr_end
;
1160 static void __meminitdata
*p_start
, *p_end
;
1161 static int __meminitdata node_start
;
1163 static int __meminit
vmemmap_populate_hugepages(unsigned long start
,
1164 unsigned long end
, int node
, struct vmem_altmap
*altmap
)
1172 for (addr
= start
; addr
< end
; addr
= next
) {
1173 next
= pmd_addr_end(addr
, end
);
1175 pgd
= vmemmap_pgd_populate(addr
, node
);
1179 pud
= vmemmap_pud_populate(pgd
, addr
, node
);
1183 pmd
= pmd_offset(pud
, addr
);
1184 if (pmd_none(*pmd
)) {
1187 p
= __vmemmap_alloc_block_buf(PMD_SIZE
, node
, altmap
);
1191 entry
= pfn_pte(__pa(p
) >> PAGE_SHIFT
,
1193 set_pmd(pmd
, __pmd(pte_val(entry
)));
1195 /* check to see if we have contiguous blocks */
1196 if (p_end
!= p
|| node_start
!= node
) {
1198 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1199 addr_start
, addr_end
-1, p_start
, p_end
-1, node_start
);
1205 addr_end
= addr
+ PMD_SIZE
;
1206 p_end
= p
+ PMD_SIZE
;
1209 return -ENOMEM
; /* no fallback */
1210 } else if (pmd_large(*pmd
)) {
1211 vmemmap_verify((pte_t
*)pmd
, node
, addr
, next
);
1214 pr_warn_once("vmemmap: falling back to regular page backing\n");
1215 if (vmemmap_populate_basepages(addr
, next
, node
))
1221 int __meminit
vmemmap_populate(unsigned long start
, unsigned long end
, int node
)
1223 struct vmem_altmap
*altmap
= to_vmem_altmap(start
);
1226 if (boot_cpu_has(X86_FEATURE_PSE
))
1227 err
= vmemmap_populate_hugepages(start
, end
, node
, altmap
);
1229 pr_err_once("%s: no cpu support for altmap allocations\n",
1233 err
= vmemmap_populate_basepages(start
, end
, node
);
1235 sync_global_pgds(start
, end
- 1, 0);
1239 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE)
1240 void register_page_bootmem_memmap(unsigned long section_nr
,
1241 struct page
*start_page
, unsigned long size
)
1243 unsigned long addr
= (unsigned long)start_page
;
1244 unsigned long end
= (unsigned long)(start_page
+ size
);
1249 unsigned int nr_pages
;
1252 for (; addr
< end
; addr
= next
) {
1255 pgd
= pgd_offset_k(addr
);
1256 if (pgd_none(*pgd
)) {
1257 next
= (addr
+ PAGE_SIZE
) & PAGE_MASK
;
1260 get_page_bootmem(section_nr
, pgd_page(*pgd
), MIX_SECTION_INFO
);
1262 pud
= pud_offset(pgd
, addr
);
1263 if (pud_none(*pud
)) {
1264 next
= (addr
+ PAGE_SIZE
) & PAGE_MASK
;
1267 get_page_bootmem(section_nr
, pud_page(*pud
), MIX_SECTION_INFO
);
1269 if (!boot_cpu_has(X86_FEATURE_PSE
)) {
1270 next
= (addr
+ PAGE_SIZE
) & PAGE_MASK
;
1271 pmd
= pmd_offset(pud
, addr
);
1274 get_page_bootmem(section_nr
, pmd_page(*pmd
),
1277 pte
= pte_offset_kernel(pmd
, addr
);
1280 get_page_bootmem(section_nr
, pte_page(*pte
),
1283 next
= pmd_addr_end(addr
, end
);
1285 pmd
= pmd_offset(pud
, addr
);
1289 nr_pages
= 1 << (get_order(PMD_SIZE
));
1290 page
= pmd_page(*pmd
);
1292 get_page_bootmem(section_nr
, page
++,
1299 void __meminit
vmemmap_populate_print_last(void)
1302 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1303 addr_start
, addr_end
-1, p_start
, p_end
-1, node_start
);