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/memory.h>
31 #include <linux/memory_hotplug.h>
32 #include <linux/memremap.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/uv/uv.h>
56 #include <asm/setup.h>
58 #include "mm_internal.h"
60 #include "ident_map.c"
63 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
64 * physical space so we can cache the place of the first one and move
65 * around without checking the pgd every time.
68 pteval_t __supported_pte_mask __read_mostly = ~0;
69 EXPORT_SYMBOL_GPL(__supported_pte_mask);
71 int force_personality32;
75 * Control non executable heap for 32bit processes.
76 * To control the stack too use noexec=off
78 * on PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
79 * off PROT_READ implies PROT_EXEC
81 static int __init nonx32_setup(char *str)
83 if (!strcmp(str, "on"))
84 force_personality32 &= ~READ_IMPLIES_EXEC;
85 else if (!strcmp(str, "off"))
86 force_personality32 |= READ_IMPLIES_EXEC;
89 __setup("noexec32=", nonx32_setup);
92 * When memory was added/removed make sure all the processes MM have
93 * suitable PGD entries in the local PGD level page.
95 void sync_global_pgds(unsigned long start, unsigned long end, int removed)
97 unsigned long address;
99 for (address = start; address <= end; address += PGDIR_SIZE) {
100 const pgd_t *pgd_ref = pgd_offset_k(address);
104 * When it is called after memory hot remove, pgd_none()
105 * returns true. In this case (removed == 1), we must clear
106 * the PGD entries in the local PGD level page.
108 if (pgd_none(*pgd_ref) && !removed)
111 spin_lock(&pgd_lock);
112 list_for_each_entry(page, &pgd_list, lru) {
114 spinlock_t *pgt_lock;
116 pgd = (pgd_t *)page_address(page) + pgd_index(address);
117 /* the pgt_lock only for Xen */
118 pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
121 if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
122 BUG_ON(pgd_page_vaddr(*pgd)
123 != pgd_page_vaddr(*pgd_ref));
126 if (pgd_none(*pgd_ref) && !pgd_none(*pgd))
130 set_pgd(pgd, *pgd_ref);
133 spin_unlock(pgt_lock);
135 spin_unlock(&pgd_lock);
140 * NOTE: This function is marked __ref because it calls __init function
141 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
143 static __ref void *spp_getpage(void)
148 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
150 ptr = alloc_bootmem_pages(PAGE_SIZE);
152 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
153 panic("set_pte_phys: cannot allocate page data %s\n",
154 after_bootmem ? "after bootmem" : "");
157 pr_debug("spp_getpage %p\n", ptr);
162 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr)
164 if (pgd_none(*pgd)) {
165 pud_t *pud = (pud_t *)spp_getpage();
166 pgd_populate(&init_mm, pgd, pud);
167 if (pud != pud_offset(pgd, 0))
168 printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
169 pud, pud_offset(pgd, 0));
171 return pud_offset(pgd, vaddr);
174 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
176 if (pud_none(*pud)) {
177 pmd_t *pmd = (pmd_t *) spp_getpage();
178 pud_populate(&init_mm, pud, pmd);
179 if (pmd != pmd_offset(pud, 0))
180 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
181 pmd, pmd_offset(pud, 0));
183 return pmd_offset(pud, vaddr);
186 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
188 if (pmd_none(*pmd)) {
189 pte_t *pte = (pte_t *) spp_getpage();
190 pmd_populate_kernel(&init_mm, pmd, pte);
191 if (pte != pte_offset_kernel(pmd, 0))
192 printk(KERN_ERR "PAGETABLE BUG #02!\n");
194 return pte_offset_kernel(pmd, vaddr);
197 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
203 pud = pud_page + pud_index(vaddr);
204 pmd = fill_pmd(pud, vaddr);
205 pte = fill_pte(pmd, vaddr);
207 set_pte(pte, new_pte);
210 * It's enough to flush this one mapping.
211 * (PGE mappings get flushed as well)
213 __flush_tlb_one(vaddr);
216 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
221 pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
223 pgd = pgd_offset_k(vaddr);
224 if (pgd_none(*pgd)) {
226 "PGD FIXMAP MISSING, it should be setup in head.S!\n");
229 pud_page = (pud_t*)pgd_page_vaddr(*pgd);
230 set_pte_vaddr_pud(pud_page, vaddr, pteval);
233 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
238 pgd = pgd_offset_k(vaddr);
239 pud = fill_pud(pgd, vaddr);
240 return fill_pmd(pud, vaddr);
243 pte_t * __init populate_extra_pte(unsigned long vaddr)
247 pmd = populate_extra_pmd(vaddr);
248 return fill_pte(pmd, vaddr);
252 * Create large page table mappings for a range of physical addresses.
254 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
255 enum page_cache_mode cache)
262 pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
263 pgprot_val(pgprot_4k_2_large(cachemode2pgprot(cache)));
264 BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
265 for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
266 pgd = pgd_offset_k((unsigned long)__va(phys));
267 if (pgd_none(*pgd)) {
268 pud = (pud_t *) spp_getpage();
269 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
272 pud = pud_offset(pgd, (unsigned long)__va(phys));
273 if (pud_none(*pud)) {
274 pmd = (pmd_t *) spp_getpage();
275 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
278 pmd = pmd_offset(pud, phys);
279 BUG_ON(!pmd_none(*pmd));
280 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
284 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
286 __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
289 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
291 __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC);
295 * The head.S code sets up the kernel high mapping:
297 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
299 * phys_base holds the negative offset to the kernel, which is added
300 * to the compile time generated pmds. This results in invalid pmds up
301 * to the point where we hit the physaddr 0 mapping.
303 * We limit the mappings to the region from _text to _brk_end. _brk_end
304 * is rounded up to the 2MB boundary. This catches the invalid pmds as
305 * well, as they are located before _text:
307 void __init cleanup_highmap(void)
309 unsigned long vaddr = __START_KERNEL_map;
310 unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
311 unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
312 pmd_t *pmd = level2_kernel_pgt;
315 * Native path, max_pfn_mapped is not set yet.
316 * Xen has valid max_pfn_mapped set in
317 * arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
320 vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
322 for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
325 if (vaddr < (unsigned long) _text || vaddr > end)
326 set_pmd(pmd, __pmd(0));
330 static unsigned long __meminit
331 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
334 unsigned long pages = 0, next;
335 unsigned long last_map_addr = end;
338 pte_t *pte = pte_page + pte_index(addr);
340 for (i = pte_index(addr); i < PTRS_PER_PTE; i++, addr = next, pte++) {
341 next = (addr & PAGE_MASK) + PAGE_SIZE;
343 if (!after_bootmem &&
344 !e820_any_mapped(addr & PAGE_MASK, next, E820_RAM) &&
345 !e820_any_mapped(addr & PAGE_MASK, next, E820_RESERVED_KERN))
346 set_pte(pte, __pte(0));
351 * We will re-use the existing mapping.
352 * Xen for example has some special requirements, like mapping
353 * pagetable pages as RO. So assume someone who pre-setup
354 * these mappings are more intelligent.
363 printk(" pte=%p addr=%lx pte=%016lx\n",
364 pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
366 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
367 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
370 update_page_count(PG_LEVEL_4K, pages);
372 return last_map_addr;
375 static unsigned long __meminit
376 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
377 unsigned long page_size_mask, pgprot_t prot)
379 unsigned long pages = 0, next;
380 unsigned long last_map_addr = end;
382 int i = pmd_index(address);
384 for (; i < PTRS_PER_PMD; i++, address = next) {
385 pmd_t *pmd = pmd_page + pmd_index(address);
387 pgprot_t new_prot = prot;
389 next = (address & PMD_MASK) + PMD_SIZE;
390 if (address >= end) {
391 if (!after_bootmem &&
392 !e820_any_mapped(address & PMD_MASK, next, E820_RAM) &&
393 !e820_any_mapped(address & PMD_MASK, next, E820_RESERVED_KERN))
394 set_pmd(pmd, __pmd(0));
399 if (!pmd_large(*pmd)) {
400 spin_lock(&init_mm.page_table_lock);
401 pte = (pte_t *)pmd_page_vaddr(*pmd);
402 last_map_addr = phys_pte_init(pte, address,
404 spin_unlock(&init_mm.page_table_lock);
408 * If we are ok with PG_LEVEL_2M mapping, then we will
409 * use the existing mapping,
411 * Otherwise, we will split the large page mapping but
412 * use the same existing protection bits except for
413 * large page, so that we don't violate Intel's TLB
414 * Application note (317080) which says, while changing
415 * the page sizes, new and old translations should
416 * not differ with respect to page frame and
419 if (page_size_mask & (1 << PG_LEVEL_2M)) {
422 last_map_addr = next;
425 new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
428 if (page_size_mask & (1<<PG_LEVEL_2M)) {
430 spin_lock(&init_mm.page_table_lock);
431 set_pte((pte_t *)pmd,
432 pfn_pte((address & PMD_MASK) >> PAGE_SHIFT,
433 __pgprot(pgprot_val(prot) | _PAGE_PSE)));
434 spin_unlock(&init_mm.page_table_lock);
435 last_map_addr = next;
439 pte = alloc_low_page();
440 last_map_addr = phys_pte_init(pte, address, end, new_prot);
442 spin_lock(&init_mm.page_table_lock);
443 pmd_populate_kernel(&init_mm, pmd, pte);
444 spin_unlock(&init_mm.page_table_lock);
446 update_page_count(PG_LEVEL_2M, pages);
447 return last_map_addr;
450 static unsigned long __meminit
451 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
452 unsigned long page_size_mask)
454 unsigned long pages = 0, next;
455 unsigned long last_map_addr = end;
456 int i = pud_index(addr);
458 for (; i < PTRS_PER_PUD; i++, addr = next) {
459 pud_t *pud = pud_page + pud_index(addr);
461 pgprot_t prot = PAGE_KERNEL;
463 next = (addr & PUD_MASK) + PUD_SIZE;
465 if (!after_bootmem &&
466 !e820_any_mapped(addr & PUD_MASK, next, E820_RAM) &&
467 !e820_any_mapped(addr & PUD_MASK, next, E820_RESERVED_KERN))
468 set_pud(pud, __pud(0));
473 if (!pud_large(*pud)) {
474 pmd = pmd_offset(pud, 0);
475 last_map_addr = phys_pmd_init(pmd, addr, end,
476 page_size_mask, prot);
481 * If we are ok with PG_LEVEL_1G mapping, then we will
482 * use the existing mapping.
484 * Otherwise, we will split the gbpage mapping but use
485 * the same existing protection bits except for large
486 * page, so that we don't violate Intel's TLB
487 * Application note (317080) which says, while changing
488 * the page sizes, new and old translations should
489 * not differ with respect to page frame and
492 if (page_size_mask & (1 << PG_LEVEL_1G)) {
495 last_map_addr = next;
498 prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
501 if (page_size_mask & (1<<PG_LEVEL_1G)) {
503 spin_lock(&init_mm.page_table_lock);
504 set_pte((pte_t *)pud,
505 pfn_pte((addr & PUD_MASK) >> PAGE_SHIFT,
507 spin_unlock(&init_mm.page_table_lock);
508 last_map_addr = next;
512 pmd = alloc_low_page();
513 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
516 spin_lock(&init_mm.page_table_lock);
517 pud_populate(&init_mm, pud, pmd);
518 spin_unlock(&init_mm.page_table_lock);
522 update_page_count(PG_LEVEL_1G, pages);
524 return last_map_addr;
527 unsigned long __meminit
528 kernel_physical_mapping_init(unsigned long start,
530 unsigned long page_size_mask)
532 bool pgd_changed = false;
533 unsigned long next, last_map_addr = end;
536 start = (unsigned long)__va(start);
537 end = (unsigned long)__va(end);
540 for (; start < end; start = next) {
541 pgd_t *pgd = pgd_offset_k(start);
544 next = (start & PGDIR_MASK) + PGDIR_SIZE;
547 pud = (pud_t *)pgd_page_vaddr(*pgd);
548 last_map_addr = phys_pud_init(pud, __pa(start),
549 __pa(end), page_size_mask);
553 pud = alloc_low_page();
554 last_map_addr = phys_pud_init(pud, __pa(start), __pa(end),
557 spin_lock(&init_mm.page_table_lock);
558 pgd_populate(&init_mm, pgd, pud);
559 spin_unlock(&init_mm.page_table_lock);
564 sync_global_pgds(addr, end - 1, 0);
568 return last_map_addr;
572 void __init initmem_init(void)
574 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
578 void __init paging_init(void)
580 sparse_memory_present_with_active_regions(MAX_NUMNODES);
584 * clear the default setting with node 0
585 * note: don't use nodes_clear here, that is really clearing when
586 * numa support is not compiled in, and later node_set_state
587 * will not set it back.
589 node_clear_state(0, N_MEMORY);
590 if (N_MEMORY != N_NORMAL_MEMORY)
591 node_clear_state(0, N_NORMAL_MEMORY);
597 * Memory hotplug specific functions
599 #ifdef CONFIG_MEMORY_HOTPLUG
601 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
604 static void update_end_of_memory_vars(u64 start, u64 size)
606 unsigned long end_pfn = PFN_UP(start + size);
608 if (end_pfn > max_pfn) {
610 max_low_pfn = end_pfn;
611 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
616 * Memory is added always to NORMAL zone. This means you will never get
617 * additional DMA/DMA32 memory.
619 int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
621 struct pglist_data *pgdat = NODE_DATA(nid);
622 struct zone *zone = pgdat->node_zones +
623 zone_for_memory(nid, start, size, ZONE_NORMAL, for_device);
624 unsigned long start_pfn = start >> PAGE_SHIFT;
625 unsigned long nr_pages = size >> PAGE_SHIFT;
628 init_memory_mapping(start, start + size);
630 ret = __add_pages(nid, zone, start_pfn, nr_pages);
633 /* update max_pfn, max_low_pfn and high_memory */
634 update_end_of_memory_vars(start, size);
638 EXPORT_SYMBOL_GPL(arch_add_memory);
640 #define PAGE_INUSE 0xFD
642 static void __meminit free_pagetable(struct page *page, int order)
645 unsigned int nr_pages = 1 << order;
646 struct vmem_altmap *altmap = to_vmem_altmap((unsigned long) page);
649 vmem_altmap_free(altmap, nr_pages);
653 /* bootmem page has reserved flag */
654 if (PageReserved(page)) {
655 __ClearPageReserved(page);
657 magic = (unsigned long)page->lru.next;
658 if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
660 put_page_bootmem(page++);
663 free_reserved_page(page++);
665 free_pages((unsigned long)page_address(page), order);
668 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
673 for (i = 0; i < PTRS_PER_PTE; i++) {
679 /* free a pte talbe */
680 free_pagetable(pmd_page(*pmd), 0);
681 spin_lock(&init_mm.page_table_lock);
683 spin_unlock(&init_mm.page_table_lock);
686 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
691 for (i = 0; i < PTRS_PER_PMD; i++) {
697 /* free a pmd talbe */
698 free_pagetable(pud_page(*pud), 0);
699 spin_lock(&init_mm.page_table_lock);
701 spin_unlock(&init_mm.page_table_lock);
704 /* Return true if pgd is changed, otherwise return false. */
705 static bool __meminit free_pud_table(pud_t *pud_start, pgd_t *pgd)
710 for (i = 0; i < PTRS_PER_PUD; i++) {
716 /* free a pud table */
717 free_pagetable(pgd_page(*pgd), 0);
718 spin_lock(&init_mm.page_table_lock);
720 spin_unlock(&init_mm.page_table_lock);
725 static void __meminit
726 remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
729 unsigned long next, pages = 0;
732 phys_addr_t phys_addr;
734 pte = pte_start + pte_index(addr);
735 for (; addr < end; addr = next, pte++) {
736 next = (addr + PAGE_SIZE) & PAGE_MASK;
740 if (!pte_present(*pte))
744 * We mapped [0,1G) memory as identity mapping when
745 * initializing, in arch/x86/kernel/head_64.S. These
746 * pagetables cannot be removed.
748 phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
749 if (phys_addr < (phys_addr_t)0x40000000)
752 if (PAGE_ALIGNED(addr) && PAGE_ALIGNED(next)) {
754 * Do not free direct mapping pages since they were
755 * freed when offlining, or simplely not in use.
758 free_pagetable(pte_page(*pte), 0);
760 spin_lock(&init_mm.page_table_lock);
761 pte_clear(&init_mm, addr, pte);
762 spin_unlock(&init_mm.page_table_lock);
764 /* For non-direct mapping, pages means nothing. */
768 * If we are here, we are freeing vmemmap pages since
769 * direct mapped memory ranges to be freed are aligned.
771 * If we are not removing the whole page, it means
772 * other page structs in this page are being used and
773 * we canot remove them. So fill the unused page_structs
774 * with 0xFD, and remove the page when it is wholly
777 memset((void *)addr, PAGE_INUSE, next - addr);
779 page_addr = page_address(pte_page(*pte));
780 if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
781 free_pagetable(pte_page(*pte), 0);
783 spin_lock(&init_mm.page_table_lock);
784 pte_clear(&init_mm, addr, pte);
785 spin_unlock(&init_mm.page_table_lock);
790 /* Call free_pte_table() in remove_pmd_table(). */
793 update_page_count(PG_LEVEL_4K, -pages);
796 static void __meminit
797 remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
800 unsigned long next, pages = 0;
805 pmd = pmd_start + pmd_index(addr);
806 for (; addr < end; addr = next, pmd++) {
807 next = pmd_addr_end(addr, end);
809 if (!pmd_present(*pmd))
812 if (pmd_large(*pmd)) {
813 if (IS_ALIGNED(addr, PMD_SIZE) &&
814 IS_ALIGNED(next, PMD_SIZE)) {
816 free_pagetable(pmd_page(*pmd),
817 get_order(PMD_SIZE));
819 spin_lock(&init_mm.page_table_lock);
821 spin_unlock(&init_mm.page_table_lock);
824 /* If here, we are freeing vmemmap pages. */
825 memset((void *)addr, PAGE_INUSE, next - addr);
827 page_addr = page_address(pmd_page(*pmd));
828 if (!memchr_inv(page_addr, PAGE_INUSE,
830 free_pagetable(pmd_page(*pmd),
831 get_order(PMD_SIZE));
833 spin_lock(&init_mm.page_table_lock);
835 spin_unlock(&init_mm.page_table_lock);
842 pte_base = (pte_t *)pmd_page_vaddr(*pmd);
843 remove_pte_table(pte_base, addr, next, direct);
844 free_pte_table(pte_base, pmd);
847 /* Call free_pmd_table() in remove_pud_table(). */
849 update_page_count(PG_LEVEL_2M, -pages);
852 static void __meminit
853 remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
856 unsigned long next, pages = 0;
861 pud = pud_start + pud_index(addr);
862 for (; addr < end; addr = next, pud++) {
863 next = pud_addr_end(addr, end);
865 if (!pud_present(*pud))
868 if (pud_large(*pud)) {
869 if (IS_ALIGNED(addr, PUD_SIZE) &&
870 IS_ALIGNED(next, PUD_SIZE)) {
872 free_pagetable(pud_page(*pud),
873 get_order(PUD_SIZE));
875 spin_lock(&init_mm.page_table_lock);
877 spin_unlock(&init_mm.page_table_lock);
880 /* If here, we are freeing vmemmap pages. */
881 memset((void *)addr, PAGE_INUSE, next - addr);
883 page_addr = page_address(pud_page(*pud));
884 if (!memchr_inv(page_addr, PAGE_INUSE,
886 free_pagetable(pud_page(*pud),
887 get_order(PUD_SIZE));
889 spin_lock(&init_mm.page_table_lock);
891 spin_unlock(&init_mm.page_table_lock);
898 pmd_base = (pmd_t *)pud_page_vaddr(*pud);
899 remove_pmd_table(pmd_base, addr, next, direct);
900 free_pmd_table(pmd_base, pud);
904 update_page_count(PG_LEVEL_1G, -pages);
907 /* start and end are both virtual address. */
908 static void __meminit
909 remove_pagetable(unsigned long start, unsigned long end, bool direct)
915 bool pgd_changed = false;
917 for (addr = start; addr < end; addr = next) {
918 next = pgd_addr_end(addr, end);
920 pgd = pgd_offset_k(addr);
921 if (!pgd_present(*pgd))
924 pud = (pud_t *)pgd_page_vaddr(*pgd);
925 remove_pud_table(pud, addr, next, direct);
926 if (free_pud_table(pud, pgd))
931 sync_global_pgds(start, end - 1, 1);
936 void __ref vmemmap_free(unsigned long start, unsigned long end)
938 remove_pagetable(start, end, false);
941 #ifdef CONFIG_MEMORY_HOTREMOVE
942 static void __meminit
943 kernel_physical_mapping_remove(unsigned long start, unsigned long end)
945 start = (unsigned long)__va(start);
946 end = (unsigned long)__va(end);
948 remove_pagetable(start, end, true);
951 int __ref arch_remove_memory(u64 start, u64 size)
953 unsigned long start_pfn = start >> PAGE_SHIFT;
954 unsigned long nr_pages = size >> PAGE_SHIFT;
955 struct page *page = pfn_to_page(start_pfn);
956 struct vmem_altmap *altmap;
960 /* With altmap the first mapped page is offset from @start */
961 altmap = to_vmem_altmap((unsigned long) page);
963 page += vmem_altmap_offset(altmap);
964 zone = page_zone(page);
965 ret = __remove_pages(zone, start_pfn, nr_pages);
967 kernel_physical_mapping_remove(start, start + size);
972 #endif /* CONFIG_MEMORY_HOTPLUG */
974 static struct kcore_list kcore_vsyscall;
976 static void __init register_page_bootmem_info(void)
981 for_each_online_node(i)
982 register_page_bootmem_info_node(NODE_DATA(i));
986 void __init mem_init(void)
990 /* clear_bss() already clear the empty_zero_page */
992 register_page_bootmem_info();
994 /* this will put all memory onto the freelists */
998 /* Register memory areas for /proc/kcore */
999 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR,
1000 PAGE_SIZE, KCORE_OTHER);
1002 mem_init_print_info(NULL);
1005 const int rodata_test_data = 0xC3;
1006 EXPORT_SYMBOL_GPL(rodata_test_data);
1008 int kernel_set_to_readonly;
1010 void set_kernel_text_rw(void)
1012 unsigned long start = PFN_ALIGN(_text);
1013 unsigned long end = PFN_ALIGN(__stop___ex_table);
1015 if (!kernel_set_to_readonly)
1018 pr_debug("Set kernel text: %lx - %lx for read write\n",
1022 * Make the kernel identity mapping for text RW. Kernel text
1023 * mapping will always be RO. Refer to the comment in
1024 * static_protections() in pageattr.c
1026 set_memory_rw(start, (end - start) >> PAGE_SHIFT);
1029 void set_kernel_text_ro(void)
1031 unsigned long start = PFN_ALIGN(_text);
1032 unsigned long end = PFN_ALIGN(__stop___ex_table);
1034 if (!kernel_set_to_readonly)
1037 pr_debug("Set kernel text: %lx - %lx for read only\n",
1041 * Set the kernel identity mapping for text RO.
1043 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1046 void mark_rodata_ro(void)
1048 unsigned long start = PFN_ALIGN(_text);
1049 unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1050 unsigned long end = (unsigned long) &__end_rodata_hpage_align;
1051 unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
1052 unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
1053 unsigned long all_end;
1055 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1056 (end - start) >> 10);
1057 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1059 kernel_set_to_readonly = 1;
1062 * The rodata/data/bss/brk section (but not the kernel text!)
1063 * should also be not-executable.
1065 * We align all_end to PMD_SIZE because the existing mapping
1066 * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1067 * split the PMD and the reminder between _brk_end and the end
1068 * of the PMD will remain mapped executable.
1070 * Any PMD which was setup after the one which covers _brk_end
1071 * has been zapped already via cleanup_highmem().
1073 all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
1074 set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
1078 #ifdef CONFIG_CPA_DEBUG
1079 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1080 set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1082 printk(KERN_INFO "Testing CPA: again\n");
1083 set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1086 free_init_pages("unused kernel",
1087 (unsigned long) __va(__pa_symbol(text_end)),
1088 (unsigned long) __va(__pa_symbol(rodata_start)));
1089 free_init_pages("unused kernel",
1090 (unsigned long) __va(__pa_symbol(rodata_end)),
1091 (unsigned long) __va(__pa_symbol(_sdata)));
1096 int kern_addr_valid(unsigned long addr)
1098 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1104 if (above != 0 && above != -1UL)
1107 pgd = pgd_offset_k(addr);
1111 pud = pud_offset(pgd, addr);
1115 if (pud_large(*pud))
1116 return pfn_valid(pud_pfn(*pud));
1118 pmd = pmd_offset(pud, addr);
1122 if (pmd_large(*pmd))
1123 return pfn_valid(pmd_pfn(*pmd));
1125 pte = pte_offset_kernel(pmd, addr);
1129 return pfn_valid(pte_pfn(*pte));
1132 static unsigned long probe_memory_block_size(void)
1134 unsigned long bz = MIN_MEMORY_BLOCK_SIZE;
1136 /* if system is UV or has 64GB of RAM or more, use large blocks */
1137 if (is_uv_system() || ((max_pfn << PAGE_SHIFT) >= (64UL << 30)))
1138 bz = 2UL << 30; /* 2GB */
1140 pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
1145 static unsigned long memory_block_size_probed;
1146 unsigned long memory_block_size_bytes(void)
1148 if (!memory_block_size_probed)
1149 memory_block_size_probed = probe_memory_block_size();
1151 return memory_block_size_probed;
1154 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1156 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1158 static long __meminitdata addr_start, addr_end;
1159 static void __meminitdata *p_start, *p_end;
1160 static int __meminitdata node_start;
1162 static int __meminit vmemmap_populate_hugepages(unsigned long start,
1163 unsigned long end, int node, struct vmem_altmap *altmap)
1171 for (addr = start; addr < end; addr = next) {
1172 next = pmd_addr_end(addr, end);
1174 pgd = vmemmap_pgd_populate(addr, node);
1178 pud = vmemmap_pud_populate(pgd, addr, node);
1182 pmd = pmd_offset(pud, addr);
1183 if (pmd_none(*pmd)) {
1186 p = __vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
1190 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1192 set_pmd(pmd, __pmd(pte_val(entry)));
1194 /* check to see if we have contiguous blocks */
1195 if (p_end != p || node_start != node) {
1197 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1198 addr_start, addr_end-1, p_start, p_end-1, node_start);
1204 addr_end = addr + PMD_SIZE;
1205 p_end = p + PMD_SIZE;
1208 return -ENOMEM; /* no fallback */
1209 } else if (pmd_large(*pmd)) {
1210 vmemmap_verify((pte_t *)pmd, node, addr, next);
1213 pr_warn_once("vmemmap: falling back to regular page backing\n");
1214 if (vmemmap_populate_basepages(addr, next, node))
1220 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
1222 struct vmem_altmap *altmap = to_vmem_altmap(start);
1225 if (boot_cpu_has(X86_FEATURE_PSE))
1226 err = vmemmap_populate_hugepages(start, end, node, altmap);
1228 pr_err_once("%s: no cpu support for altmap allocations\n",
1232 err = vmemmap_populate_basepages(start, end, node);
1234 sync_global_pgds(start, end - 1, 0);
1238 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE)
1239 void register_page_bootmem_memmap(unsigned long section_nr,
1240 struct page *start_page, unsigned long size)
1242 unsigned long addr = (unsigned long)start_page;
1243 unsigned long end = (unsigned long)(start_page + size);
1248 unsigned int nr_pages;
1251 for (; addr < end; addr = next) {
1254 pgd = pgd_offset_k(addr);
1255 if (pgd_none(*pgd)) {
1256 next = (addr + PAGE_SIZE) & PAGE_MASK;
1259 get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1261 pud = pud_offset(pgd, addr);
1262 if (pud_none(*pud)) {
1263 next = (addr + PAGE_SIZE) & PAGE_MASK;
1266 get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1268 if (!boot_cpu_has(X86_FEATURE_PSE)) {
1269 next = (addr + PAGE_SIZE) & PAGE_MASK;
1270 pmd = pmd_offset(pud, addr);
1273 get_page_bootmem(section_nr, pmd_page(*pmd),
1276 pte = pte_offset_kernel(pmd, addr);
1279 get_page_bootmem(section_nr, pte_page(*pte),
1282 next = pmd_addr_end(addr, end);
1284 pmd = pmd_offset(pud, addr);
1288 nr_pages = 1 << (get_order(PMD_SIZE));
1289 page = pmd_page(*pmd);
1291 get_page_bootmem(section_nr, page++,
1298 void __meminit vmemmap_populate_print_last(void)
1301 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1302 addr_start, addr_end-1, p_start, p_end-1, node_start);