2 * linux/arch/x86_64/mm/init.c
4 * Copyright (C) 1995 Linus Torvalds
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/nmi.h>
34 #include <linux/gfp.h>
35 #include <linux/kcore.h>
37 #include <asm/processor.h>
38 #include <asm/bios_ebda.h>
39 #include <asm/uaccess.h>
40 #include <asm/pgtable.h>
41 #include <asm/pgalloc.h>
43 #include <asm/fixmap.h>
47 #include <asm/mmu_context.h>
48 #include <asm/proto.h>
50 #include <asm/sections.h>
51 #include <asm/kdebug.h>
53 #include <asm/cacheflush.h>
55 #include <asm/setup.h>
57 #include "mm_internal.h"
59 static void ident_pmd_init(unsigned long pmd_flag, pmd_t *pmd_page,
60 unsigned long addr, unsigned long end)
63 for (; addr < end; addr += PMD_SIZE) {
64 pmd_t *pmd = pmd_page + pmd_index(addr);
66 if (!pmd_present(*pmd))
67 set_pmd(pmd, __pmd(addr | pmd_flag));
70 static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page,
71 unsigned long addr, unsigned long end)
75 for (; addr < end; addr = next) {
76 pud_t *pud = pud_page + pud_index(addr);
79 next = (addr & PUD_MASK) + PUD_SIZE;
83 if (pud_present(*pud)) {
84 pmd = pmd_offset(pud, 0);
85 ident_pmd_init(info->pmd_flag, pmd, addr, next);
88 pmd = (pmd_t *)info->alloc_pgt_page(info->context);
91 ident_pmd_init(info->pmd_flag, pmd, addr, next);
92 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
98 int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page,
99 unsigned long addr, unsigned long end)
103 int off = info->kernel_mapping ? pgd_index(__PAGE_OFFSET) : 0;
105 for (; addr < end; addr = next) {
106 pgd_t *pgd = pgd_page + pgd_index(addr) + off;
109 next = (addr & PGDIR_MASK) + PGDIR_SIZE;
113 if (pgd_present(*pgd)) {
114 pud = pud_offset(pgd, 0);
115 result = ident_pud_init(info, pud, addr, next);
121 pud = (pud_t *)info->alloc_pgt_page(info->context);
124 result = ident_pud_init(info, pud, addr, next);
127 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
133 static int __init parse_direct_gbpages_off(char *arg)
138 early_param("nogbpages", parse_direct_gbpages_off);
140 static int __init parse_direct_gbpages_on(char *arg)
145 early_param("gbpages", parse_direct_gbpages_on);
148 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
149 * physical space so we can cache the place of the first one and move
150 * around without checking the pgd every time.
153 pteval_t __supported_pte_mask __read_mostly = ~0;
154 EXPORT_SYMBOL_GPL(__supported_pte_mask);
156 int force_personality32;
160 * Control non executable heap for 32bit processes.
161 * To control the stack too use noexec=off
163 * on PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
164 * off PROT_READ implies PROT_EXEC
166 static int __init nonx32_setup(char *str)
168 if (!strcmp(str, "on"))
169 force_personality32 &= ~READ_IMPLIES_EXEC;
170 else if (!strcmp(str, "off"))
171 force_personality32 |= READ_IMPLIES_EXEC;
174 __setup("noexec32=", nonx32_setup);
177 * When memory was added/removed make sure all the processes MM have
178 * suitable PGD entries in the local PGD level page.
180 void sync_global_pgds(unsigned long start, unsigned long end, int removed)
182 unsigned long address;
184 for (address = start; address <= end; address += PGDIR_SIZE) {
185 const pgd_t *pgd_ref = pgd_offset_k(address);
189 * When it is called after memory hot remove, pgd_none()
190 * returns true. In this case (removed == 1), we must clear
191 * the PGD entries in the local PGD level page.
193 if (pgd_none(*pgd_ref) && !removed)
196 spin_lock(&pgd_lock);
197 list_for_each_entry(page, &pgd_list, lru) {
199 spinlock_t *pgt_lock;
201 pgd = (pgd_t *)page_address(page) + pgd_index(address);
202 /* the pgt_lock only for Xen */
203 pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
206 if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
207 BUG_ON(pgd_page_vaddr(*pgd)
208 != pgd_page_vaddr(*pgd_ref));
211 if (pgd_none(*pgd_ref) && !pgd_none(*pgd))
215 set_pgd(pgd, *pgd_ref);
218 spin_unlock(pgt_lock);
220 spin_unlock(&pgd_lock);
225 * NOTE: This function is marked __ref because it calls __init function
226 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
228 static __ref void *spp_getpage(void)
233 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
235 ptr = alloc_bootmem_pages(PAGE_SIZE);
237 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
238 panic("set_pte_phys: cannot allocate page data %s\n",
239 after_bootmem ? "after bootmem" : "");
242 pr_debug("spp_getpage %p\n", ptr);
247 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr)
249 if (pgd_none(*pgd)) {
250 pud_t *pud = (pud_t *)spp_getpage();
251 pgd_populate(&init_mm, pgd, pud);
252 if (pud != pud_offset(pgd, 0))
253 printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
254 pud, pud_offset(pgd, 0));
256 return pud_offset(pgd, vaddr);
259 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
261 if (pud_none(*pud)) {
262 pmd_t *pmd = (pmd_t *) spp_getpage();
263 pud_populate(&init_mm, pud, pmd);
264 if (pmd != pmd_offset(pud, 0))
265 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
266 pmd, pmd_offset(pud, 0));
268 return pmd_offset(pud, vaddr);
271 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
273 if (pmd_none(*pmd)) {
274 pte_t *pte = (pte_t *) spp_getpage();
275 pmd_populate_kernel(&init_mm, pmd, pte);
276 if (pte != pte_offset_kernel(pmd, 0))
277 printk(KERN_ERR "PAGETABLE BUG #02!\n");
279 return pte_offset_kernel(pmd, vaddr);
282 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
288 pud = pud_page + pud_index(vaddr);
289 pmd = fill_pmd(pud, vaddr);
290 pte = fill_pte(pmd, vaddr);
292 set_pte(pte, new_pte);
295 * It's enough to flush this one mapping.
296 * (PGE mappings get flushed as well)
298 __flush_tlb_one(vaddr);
301 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
306 pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
308 pgd = pgd_offset_k(vaddr);
309 if (pgd_none(*pgd)) {
311 "PGD FIXMAP MISSING, it should be setup in head.S!\n");
314 pud_page = (pud_t*)pgd_page_vaddr(*pgd);
315 set_pte_vaddr_pud(pud_page, vaddr, pteval);
318 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
323 pgd = pgd_offset_k(vaddr);
324 pud = fill_pud(pgd, vaddr);
325 return fill_pmd(pud, vaddr);
328 pte_t * __init populate_extra_pte(unsigned long vaddr)
332 pmd = populate_extra_pmd(vaddr);
333 return fill_pte(pmd, vaddr);
337 * Create large page table mappings for a range of physical addresses.
339 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
340 enum page_cache_mode cache)
347 pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
348 pgprot_val(pgprot_4k_2_large(cachemode2pgprot(cache)));
349 BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
350 for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
351 pgd = pgd_offset_k((unsigned long)__va(phys));
352 if (pgd_none(*pgd)) {
353 pud = (pud_t *) spp_getpage();
354 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
357 pud = pud_offset(pgd, (unsigned long)__va(phys));
358 if (pud_none(*pud)) {
359 pmd = (pmd_t *) spp_getpage();
360 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
363 pmd = pmd_offset(pud, phys);
364 BUG_ON(!pmd_none(*pmd));
365 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
369 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
371 __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
374 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
376 __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC);
380 * The head.S code sets up the kernel high mapping:
382 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
384 * phys_base holds the negative offset to the kernel, which is added
385 * to the compile time generated pmds. This results in invalid pmds up
386 * to the point where we hit the physaddr 0 mapping.
388 * We limit the mappings to the region from _text to _brk_end. _brk_end
389 * is rounded up to the 2MB boundary. This catches the invalid pmds as
390 * well, as they are located before _text:
392 void __init cleanup_highmap(void)
394 unsigned long vaddr = __START_KERNEL_map;
395 unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
396 unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
397 pmd_t *pmd = level2_kernel_pgt;
400 * Native path, max_pfn_mapped is not set yet.
401 * Xen has valid max_pfn_mapped set in
402 * arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
405 vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
407 for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
410 if (vaddr < (unsigned long) _text || vaddr > end)
411 set_pmd(pmd, __pmd(0));
415 static unsigned long __meminit
416 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
419 unsigned long pages = 0, next;
420 unsigned long last_map_addr = end;
423 pte_t *pte = pte_page + pte_index(addr);
425 for (i = pte_index(addr); i < PTRS_PER_PTE; i++, addr = next, pte++) {
426 next = (addr & PAGE_MASK) + PAGE_SIZE;
428 if (!after_bootmem &&
429 !e820_any_mapped(addr & PAGE_MASK, next, E820_RAM) &&
430 !e820_any_mapped(addr & PAGE_MASK, next, E820_RESERVED_KERN))
431 set_pte(pte, __pte(0));
436 * We will re-use the existing mapping.
437 * Xen for example has some special requirements, like mapping
438 * pagetable pages as RO. So assume someone who pre-setup
439 * these mappings are more intelligent.
448 printk(" pte=%p addr=%lx pte=%016lx\n",
449 pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
451 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
452 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
455 update_page_count(PG_LEVEL_4K, pages);
457 return last_map_addr;
460 static unsigned long __meminit
461 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
462 unsigned long page_size_mask, pgprot_t prot)
464 unsigned long pages = 0, next;
465 unsigned long last_map_addr = end;
467 int i = pmd_index(address);
469 for (; i < PTRS_PER_PMD; i++, address = next) {
470 pmd_t *pmd = pmd_page + pmd_index(address);
472 pgprot_t new_prot = prot;
474 next = (address & PMD_MASK) + PMD_SIZE;
475 if (address >= end) {
476 if (!after_bootmem &&
477 !e820_any_mapped(address & PMD_MASK, next, E820_RAM) &&
478 !e820_any_mapped(address & PMD_MASK, next, E820_RESERVED_KERN))
479 set_pmd(pmd, __pmd(0));
484 if (!pmd_large(*pmd)) {
485 spin_lock(&init_mm.page_table_lock);
486 pte = (pte_t *)pmd_page_vaddr(*pmd);
487 last_map_addr = phys_pte_init(pte, address,
489 spin_unlock(&init_mm.page_table_lock);
493 * If we are ok with PG_LEVEL_2M mapping, then we will
494 * use the existing mapping,
496 * Otherwise, we will split the large page mapping but
497 * use the same existing protection bits except for
498 * large page, so that we don't violate Intel's TLB
499 * Application note (317080) which says, while changing
500 * the page sizes, new and old translations should
501 * not differ with respect to page frame and
504 if (page_size_mask & (1 << PG_LEVEL_2M)) {
507 last_map_addr = next;
510 new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
513 if (page_size_mask & (1<<PG_LEVEL_2M)) {
515 spin_lock(&init_mm.page_table_lock);
516 set_pte((pte_t *)pmd,
517 pfn_pte((address & PMD_MASK) >> PAGE_SHIFT,
518 __pgprot(pgprot_val(prot) | _PAGE_PSE)));
519 spin_unlock(&init_mm.page_table_lock);
520 last_map_addr = next;
524 pte = alloc_low_page();
525 last_map_addr = phys_pte_init(pte, address, end, new_prot);
527 spin_lock(&init_mm.page_table_lock);
528 pmd_populate_kernel(&init_mm, pmd, pte);
529 spin_unlock(&init_mm.page_table_lock);
531 update_page_count(PG_LEVEL_2M, pages);
532 return last_map_addr;
535 static unsigned long __meminit
536 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
537 unsigned long page_size_mask)
539 unsigned long pages = 0, next;
540 unsigned long last_map_addr = end;
541 int i = pud_index(addr);
543 for (; i < PTRS_PER_PUD; i++, addr = next) {
544 pud_t *pud = pud_page + pud_index(addr);
546 pgprot_t prot = PAGE_KERNEL;
548 next = (addr & PUD_MASK) + PUD_SIZE;
550 if (!after_bootmem &&
551 !e820_any_mapped(addr & PUD_MASK, next, E820_RAM) &&
552 !e820_any_mapped(addr & PUD_MASK, next, E820_RESERVED_KERN))
553 set_pud(pud, __pud(0));
558 if (!pud_large(*pud)) {
559 pmd = pmd_offset(pud, 0);
560 last_map_addr = phys_pmd_init(pmd, addr, end,
561 page_size_mask, prot);
566 * If we are ok with PG_LEVEL_1G mapping, then we will
567 * use the existing mapping.
569 * Otherwise, we will split the gbpage mapping but use
570 * the same existing protection bits except for large
571 * page, so that we don't violate Intel's TLB
572 * Application note (317080) which says, while changing
573 * the page sizes, new and old translations should
574 * not differ with respect to page frame and
577 if (page_size_mask & (1 << PG_LEVEL_1G)) {
580 last_map_addr = next;
583 prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
586 if (page_size_mask & (1<<PG_LEVEL_1G)) {
588 spin_lock(&init_mm.page_table_lock);
589 set_pte((pte_t *)pud,
590 pfn_pte((addr & PUD_MASK) >> PAGE_SHIFT,
592 spin_unlock(&init_mm.page_table_lock);
593 last_map_addr = next;
597 pmd = alloc_low_page();
598 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
601 spin_lock(&init_mm.page_table_lock);
602 pud_populate(&init_mm, pud, pmd);
603 spin_unlock(&init_mm.page_table_lock);
607 update_page_count(PG_LEVEL_1G, pages);
609 return last_map_addr;
612 unsigned long __meminit
613 kernel_physical_mapping_init(unsigned long start,
615 unsigned long page_size_mask)
617 bool pgd_changed = false;
618 unsigned long next, last_map_addr = end;
621 start = (unsigned long)__va(start);
622 end = (unsigned long)__va(end);
625 for (; start < end; start = next) {
626 pgd_t *pgd = pgd_offset_k(start);
629 next = (start & PGDIR_MASK) + PGDIR_SIZE;
632 pud = (pud_t *)pgd_page_vaddr(*pgd);
633 last_map_addr = phys_pud_init(pud, __pa(start),
634 __pa(end), page_size_mask);
638 pud = alloc_low_page();
639 last_map_addr = phys_pud_init(pud, __pa(start), __pa(end),
642 spin_lock(&init_mm.page_table_lock);
643 pgd_populate(&init_mm, pgd, pud);
644 spin_unlock(&init_mm.page_table_lock);
649 sync_global_pgds(addr, end - 1, 0);
653 return last_map_addr;
657 void __init initmem_init(void)
659 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
663 void __init paging_init(void)
665 sparse_memory_present_with_active_regions(MAX_NUMNODES);
669 * clear the default setting with node 0
670 * note: don't use nodes_clear here, that is really clearing when
671 * numa support is not compiled in, and later node_set_state
672 * will not set it back.
674 node_clear_state(0, N_MEMORY);
675 if (N_MEMORY != N_NORMAL_MEMORY)
676 node_clear_state(0, N_NORMAL_MEMORY);
682 * Memory hotplug specific functions
684 #ifdef CONFIG_MEMORY_HOTPLUG
686 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
689 static void update_end_of_memory_vars(u64 start, u64 size)
691 unsigned long end_pfn = PFN_UP(start + size);
693 if (end_pfn > max_pfn) {
695 max_low_pfn = end_pfn;
696 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
701 * Memory is added always to NORMAL zone. This means you will never get
702 * additional DMA/DMA32 memory.
704 int arch_add_memory(int nid, u64 start, u64 size)
706 struct pglist_data *pgdat = NODE_DATA(nid);
707 struct zone *zone = pgdat->node_zones +
708 zone_for_memory(nid, start, size, ZONE_NORMAL);
709 unsigned long start_pfn = start >> PAGE_SHIFT;
710 unsigned long nr_pages = size >> PAGE_SHIFT;
713 init_memory_mapping(start, start + size);
715 ret = __add_pages(nid, zone, start_pfn, nr_pages);
718 /* update max_pfn, max_low_pfn and high_memory */
719 update_end_of_memory_vars(start, size);
723 EXPORT_SYMBOL_GPL(arch_add_memory);
725 #define PAGE_INUSE 0xFD
727 static void __meminit free_pagetable(struct page *page, int order)
730 unsigned int nr_pages = 1 << order;
732 /* bootmem page has reserved flag */
733 if (PageReserved(page)) {
734 __ClearPageReserved(page);
736 magic = (unsigned long)page->lru.next;
737 if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
739 put_page_bootmem(page++);
742 free_reserved_page(page++);
744 free_pages((unsigned long)page_address(page), order);
747 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
752 for (i = 0; i < PTRS_PER_PTE; i++) {
758 /* free a pte talbe */
759 free_pagetable(pmd_page(*pmd), 0);
760 spin_lock(&init_mm.page_table_lock);
762 spin_unlock(&init_mm.page_table_lock);
765 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
770 for (i = 0; i < PTRS_PER_PMD; i++) {
776 /* free a pmd talbe */
777 free_pagetable(pud_page(*pud), 0);
778 spin_lock(&init_mm.page_table_lock);
780 spin_unlock(&init_mm.page_table_lock);
783 /* Return true if pgd is changed, otherwise return false. */
784 static bool __meminit free_pud_table(pud_t *pud_start, pgd_t *pgd)
789 for (i = 0; i < PTRS_PER_PUD; i++) {
795 /* free a pud table */
796 free_pagetable(pgd_page(*pgd), 0);
797 spin_lock(&init_mm.page_table_lock);
799 spin_unlock(&init_mm.page_table_lock);
804 static void __meminit
805 remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
808 unsigned long next, pages = 0;
811 phys_addr_t phys_addr;
813 pte = pte_start + pte_index(addr);
814 for (; addr < end; addr = next, pte++) {
815 next = (addr + PAGE_SIZE) & PAGE_MASK;
819 if (!pte_present(*pte))
823 * We mapped [0,1G) memory as identity mapping when
824 * initializing, in arch/x86/kernel/head_64.S. These
825 * pagetables cannot be removed.
827 phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
828 if (phys_addr < (phys_addr_t)0x40000000)
831 if (IS_ALIGNED(addr, PAGE_SIZE) &&
832 IS_ALIGNED(next, PAGE_SIZE)) {
834 * Do not free direct mapping pages since they were
835 * freed when offlining, or simplely not in use.
838 free_pagetable(pte_page(*pte), 0);
840 spin_lock(&init_mm.page_table_lock);
841 pte_clear(&init_mm, addr, pte);
842 spin_unlock(&init_mm.page_table_lock);
844 /* For non-direct mapping, pages means nothing. */
848 * If we are here, we are freeing vmemmap pages since
849 * direct mapped memory ranges to be freed are aligned.
851 * If we are not removing the whole page, it means
852 * other page structs in this page are being used and
853 * we canot remove them. So fill the unused page_structs
854 * with 0xFD, and remove the page when it is wholly
857 memset((void *)addr, PAGE_INUSE, next - addr);
859 page_addr = page_address(pte_page(*pte));
860 if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
861 free_pagetable(pte_page(*pte), 0);
863 spin_lock(&init_mm.page_table_lock);
864 pte_clear(&init_mm, addr, pte);
865 spin_unlock(&init_mm.page_table_lock);
870 /* Call free_pte_table() in remove_pmd_table(). */
873 update_page_count(PG_LEVEL_4K, -pages);
876 static void __meminit
877 remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
880 unsigned long next, pages = 0;
885 pmd = pmd_start + pmd_index(addr);
886 for (; addr < end; addr = next, pmd++) {
887 next = pmd_addr_end(addr, end);
889 if (!pmd_present(*pmd))
892 if (pmd_large(*pmd)) {
893 if (IS_ALIGNED(addr, PMD_SIZE) &&
894 IS_ALIGNED(next, PMD_SIZE)) {
896 free_pagetable(pmd_page(*pmd),
897 get_order(PMD_SIZE));
899 spin_lock(&init_mm.page_table_lock);
901 spin_unlock(&init_mm.page_table_lock);
904 /* If here, we are freeing vmemmap pages. */
905 memset((void *)addr, PAGE_INUSE, next - addr);
907 page_addr = page_address(pmd_page(*pmd));
908 if (!memchr_inv(page_addr, PAGE_INUSE,
910 free_pagetable(pmd_page(*pmd),
911 get_order(PMD_SIZE));
913 spin_lock(&init_mm.page_table_lock);
915 spin_unlock(&init_mm.page_table_lock);
922 pte_base = (pte_t *)pmd_page_vaddr(*pmd);
923 remove_pte_table(pte_base, addr, next, direct);
924 free_pte_table(pte_base, pmd);
927 /* Call free_pmd_table() in remove_pud_table(). */
929 update_page_count(PG_LEVEL_2M, -pages);
932 static void __meminit
933 remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
936 unsigned long next, pages = 0;
941 pud = pud_start + pud_index(addr);
942 for (; addr < end; addr = next, pud++) {
943 next = pud_addr_end(addr, end);
945 if (!pud_present(*pud))
948 if (pud_large(*pud)) {
949 if (IS_ALIGNED(addr, PUD_SIZE) &&
950 IS_ALIGNED(next, PUD_SIZE)) {
952 free_pagetable(pud_page(*pud),
953 get_order(PUD_SIZE));
955 spin_lock(&init_mm.page_table_lock);
957 spin_unlock(&init_mm.page_table_lock);
960 /* If here, we are freeing vmemmap pages. */
961 memset((void *)addr, PAGE_INUSE, next - addr);
963 page_addr = page_address(pud_page(*pud));
964 if (!memchr_inv(page_addr, PAGE_INUSE,
966 free_pagetable(pud_page(*pud),
967 get_order(PUD_SIZE));
969 spin_lock(&init_mm.page_table_lock);
971 spin_unlock(&init_mm.page_table_lock);
978 pmd_base = (pmd_t *)pud_page_vaddr(*pud);
979 remove_pmd_table(pmd_base, addr, next, direct);
980 free_pmd_table(pmd_base, pud);
984 update_page_count(PG_LEVEL_1G, -pages);
987 /* start and end are both virtual address. */
988 static void __meminit
989 remove_pagetable(unsigned long start, unsigned long end, bool direct)
995 bool pgd_changed = false;
997 for (addr = start; addr < end; addr = next) {
998 next = pgd_addr_end(addr, end);
1000 pgd = pgd_offset_k(addr);
1001 if (!pgd_present(*pgd))
1004 pud = (pud_t *)pgd_page_vaddr(*pgd);
1005 remove_pud_table(pud, addr, next, direct);
1006 if (free_pud_table(pud, pgd))
1011 sync_global_pgds(start, end - 1, 1);
1016 void __ref vmemmap_free(unsigned long start, unsigned long end)
1018 remove_pagetable(start, end, false);
1021 #ifdef CONFIG_MEMORY_HOTREMOVE
1022 static void __meminit
1023 kernel_physical_mapping_remove(unsigned long start, unsigned long end)
1025 start = (unsigned long)__va(start);
1026 end = (unsigned long)__va(end);
1028 remove_pagetable(start, end, true);
1031 int __ref arch_remove_memory(u64 start, u64 size)
1033 unsigned long start_pfn = start >> PAGE_SHIFT;
1034 unsigned long nr_pages = size >> PAGE_SHIFT;
1038 zone = page_zone(pfn_to_page(start_pfn));
1039 kernel_physical_mapping_remove(start, start + size);
1040 ret = __remove_pages(zone, start_pfn, nr_pages);
1046 #endif /* CONFIG_MEMORY_HOTPLUG */
1048 static struct kcore_list kcore_vsyscall;
1050 static void __init register_page_bootmem_info(void)
1055 for_each_online_node(i)
1056 register_page_bootmem_info_node(NODE_DATA(i));
1060 void __init mem_init(void)
1064 /* clear_bss() already clear the empty_zero_page */
1066 register_page_bootmem_info();
1068 /* this will put all memory onto the freelists */
1072 /* Register memory areas for /proc/kcore */
1073 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR,
1074 PAGE_SIZE, KCORE_OTHER);
1076 mem_init_print_info(NULL);
1079 #ifdef CONFIG_DEBUG_RODATA
1080 const int rodata_test_data = 0xC3;
1081 EXPORT_SYMBOL_GPL(rodata_test_data);
1083 int kernel_set_to_readonly;
1085 void set_kernel_text_rw(void)
1087 unsigned long start = PFN_ALIGN(_text);
1088 unsigned long end = PFN_ALIGN(__stop___ex_table);
1090 if (!kernel_set_to_readonly)
1093 pr_debug("Set kernel text: %lx - %lx for read write\n",
1097 * Make the kernel identity mapping for text RW. Kernel text
1098 * mapping will always be RO. Refer to the comment in
1099 * static_protections() in pageattr.c
1101 set_memory_rw(start, (end - start) >> PAGE_SHIFT);
1104 void set_kernel_text_ro(void)
1106 unsigned long start = PFN_ALIGN(_text);
1107 unsigned long end = PFN_ALIGN(__stop___ex_table);
1109 if (!kernel_set_to_readonly)
1112 pr_debug("Set kernel text: %lx - %lx for read only\n",
1116 * Set the kernel identity mapping for text RO.
1118 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1121 void mark_rodata_ro(void)
1123 unsigned long start = PFN_ALIGN(_text);
1124 unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1125 unsigned long end = (unsigned long) &__end_rodata_hpage_align;
1126 unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
1127 unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
1128 unsigned long all_end;
1130 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1131 (end - start) >> 10);
1132 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1134 kernel_set_to_readonly = 1;
1137 * The rodata/data/bss/brk section (but not the kernel text!)
1138 * should also be not-executable.
1140 * We align all_end to PMD_SIZE because the existing mapping
1141 * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1142 * split the PMD and the reminder between _brk_end and the end
1143 * of the PMD will remain mapped executable.
1145 * Any PMD which was setup after the one which covers _brk_end
1146 * has been zapped already via cleanup_highmem().
1148 all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
1149 set_memory_nx(rodata_start, (all_end - rodata_start) >> PAGE_SHIFT);
1153 #ifdef CONFIG_CPA_DEBUG
1154 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1155 set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1157 printk(KERN_INFO "Testing CPA: again\n");
1158 set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1161 free_init_pages("unused kernel",
1162 (unsigned long) __va(__pa_symbol(text_end)),
1163 (unsigned long) __va(__pa_symbol(rodata_start)));
1164 free_init_pages("unused kernel",
1165 (unsigned long) __va(__pa_symbol(rodata_end)),
1166 (unsigned long) __va(__pa_symbol(_sdata)));
1171 int kern_addr_valid(unsigned long addr)
1173 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1179 if (above != 0 && above != -1UL)
1182 pgd = pgd_offset_k(addr);
1186 pud = pud_offset(pgd, addr);
1190 if (pud_large(*pud))
1191 return pfn_valid(pud_pfn(*pud));
1193 pmd = pmd_offset(pud, addr);
1197 if (pmd_large(*pmd))
1198 return pfn_valid(pmd_pfn(*pmd));
1200 pte = pte_offset_kernel(pmd, addr);
1204 return pfn_valid(pte_pfn(*pte));
1207 static unsigned long probe_memory_block_size(void)
1210 unsigned long bz = 1UL<<31;
1212 if (totalram_pages >= (64ULL << (30 - PAGE_SHIFT))) {
1213 pr_info("Using 2GB memory block size for large-memory system\n");
1214 return 2UL * 1024 * 1024 * 1024;
1217 /* less than 64g installed */
1218 if ((max_pfn << PAGE_SHIFT) < (16UL << 32))
1219 return MIN_MEMORY_BLOCK_SIZE;
1221 /* get the tail size */
1222 while (bz > MIN_MEMORY_BLOCK_SIZE) {
1223 if (!((max_pfn << PAGE_SHIFT) & (bz - 1)))
1228 printk(KERN_DEBUG "memory block size : %ldMB\n", bz >> 20);
1233 static unsigned long memory_block_size_probed;
1234 unsigned long memory_block_size_bytes(void)
1236 if (!memory_block_size_probed)
1237 memory_block_size_probed = probe_memory_block_size();
1239 return memory_block_size_probed;
1242 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1244 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1246 static long __meminitdata addr_start, addr_end;
1247 static void __meminitdata *p_start, *p_end;
1248 static int __meminitdata node_start;
1250 static int __meminit vmemmap_populate_hugepages(unsigned long start,
1251 unsigned long end, int node)
1259 for (addr = start; addr < end; addr = next) {
1260 next = pmd_addr_end(addr, end);
1262 pgd = vmemmap_pgd_populate(addr, node);
1266 pud = vmemmap_pud_populate(pgd, addr, node);
1270 pmd = pmd_offset(pud, addr);
1271 if (pmd_none(*pmd)) {
1274 p = vmemmap_alloc_block_buf(PMD_SIZE, node);
1278 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1280 set_pmd(pmd, __pmd(pte_val(entry)));
1282 /* check to see if we have contiguous blocks */
1283 if (p_end != p || node_start != node) {
1285 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1286 addr_start, addr_end-1, p_start, p_end-1, node_start);
1292 addr_end = addr + PMD_SIZE;
1293 p_end = p + PMD_SIZE;
1296 } else if (pmd_large(*pmd)) {
1297 vmemmap_verify((pte_t *)pmd, node, addr, next);
1300 pr_warn_once("vmemmap: falling back to regular page backing\n");
1301 if (vmemmap_populate_basepages(addr, next, node))
1307 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
1312 err = vmemmap_populate_hugepages(start, end, node);
1314 err = vmemmap_populate_basepages(start, end, node);
1316 sync_global_pgds(start, end - 1, 0);
1320 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE)
1321 void register_page_bootmem_memmap(unsigned long section_nr,
1322 struct page *start_page, unsigned long size)
1324 unsigned long addr = (unsigned long)start_page;
1325 unsigned long end = (unsigned long)(start_page + size);
1330 unsigned int nr_pages;
1333 for (; addr < end; addr = next) {
1336 pgd = pgd_offset_k(addr);
1337 if (pgd_none(*pgd)) {
1338 next = (addr + PAGE_SIZE) & PAGE_MASK;
1341 get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1343 pud = pud_offset(pgd, addr);
1344 if (pud_none(*pud)) {
1345 next = (addr + PAGE_SIZE) & PAGE_MASK;
1348 get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1351 next = (addr + PAGE_SIZE) & PAGE_MASK;
1352 pmd = pmd_offset(pud, addr);
1355 get_page_bootmem(section_nr, pmd_page(*pmd),
1358 pte = pte_offset_kernel(pmd, addr);
1361 get_page_bootmem(section_nr, pte_page(*pte),
1364 next = pmd_addr_end(addr, end);
1366 pmd = pmd_offset(pud, addr);
1370 nr_pages = 1 << (get_order(PMD_SIZE));
1371 page = pmd_page(*pmd);
1373 get_page_bootmem(section_nr, page++,
1380 void __meminit vmemmap_populate_print_last(void)
1383 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1384 addr_start, addr_end-1, p_start, p_end-1, node_start);