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);